1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2017, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree
; use Atree
;
27 with Checks
; use Checks
;
28 with Debug
; use Debug
;
29 with Einfo
; use Einfo
;
30 with Elists
; use Elists
;
31 with Errout
; use Errout
;
32 with Exp_Aggr
; use Exp_Aggr
;
33 with Exp_Atag
; use Exp_Atag
;
34 with Exp_Ch2
; use Exp_Ch2
;
35 with Exp_Ch3
; use Exp_Ch3
;
36 with Exp_Ch6
; use Exp_Ch6
;
37 with Exp_Ch7
; use Exp_Ch7
;
38 with Exp_Ch9
; use Exp_Ch9
;
39 with Exp_Disp
; use Exp_Disp
;
40 with Exp_Fixd
; use Exp_Fixd
;
41 with Exp_Intr
; use Exp_Intr
;
42 with Exp_Pakd
; use Exp_Pakd
;
43 with Exp_Tss
; use Exp_Tss
;
44 with Exp_Util
; use Exp_Util
;
45 with Freeze
; use Freeze
;
46 with Inline
; use Inline
;
47 with Namet
; use Namet
;
48 with Nlists
; use Nlists
;
49 with Nmake
; use Nmake
;
51 with Par_SCO
; use Par_SCO
;
52 with Restrict
; use Restrict
;
53 with Rident
; use Rident
;
54 with Rtsfind
; use Rtsfind
;
56 with Sem_Aux
; use Sem_Aux
;
57 with Sem_Cat
; use Sem_Cat
;
58 with Sem_Ch3
; use Sem_Ch3
;
59 with Sem_Ch13
; use Sem_Ch13
;
60 with Sem_Eval
; use Sem_Eval
;
61 with Sem_Res
; use Sem_Res
;
62 with Sem_Type
; use Sem_Type
;
63 with Sem_Util
; use Sem_Util
;
64 with Sem_Warn
; use Sem_Warn
;
65 with Sinfo
; use Sinfo
;
66 with Snames
; use Snames
;
67 with Stand
; use Stand
;
68 with SCIL_LL
; use SCIL_LL
;
69 with Targparm
; use Targparm
;
70 with Tbuild
; use Tbuild
;
71 with Ttypes
; use Ttypes
;
72 with Uintp
; use Uintp
;
73 with Urealp
; use Urealp
;
74 with Validsw
; use Validsw
;
76 package body Exp_Ch4
is
78 -----------------------
79 -- Local Subprograms --
80 -----------------------
82 procedure Binary_Op_Validity_Checks
(N
: Node_Id
);
83 pragma Inline
(Binary_Op_Validity_Checks
);
84 -- Performs validity checks for a binary operator
86 procedure Build_Boolean_Array_Proc_Call
90 -- If a boolean array assignment can be done in place, build call to
91 -- corresponding library procedure.
93 procedure Displace_Allocator_Pointer
(N
: Node_Id
);
94 -- Ada 2005 (AI-251): Subsidiary procedure to Expand_N_Allocator and
95 -- Expand_Allocator_Expression. Allocating class-wide interface objects
96 -- this routine displaces the pointer to the allocated object to reference
97 -- the component referencing the corresponding secondary dispatch table.
99 procedure Expand_Allocator_Expression
(N
: Node_Id
);
100 -- Subsidiary to Expand_N_Allocator, for the case when the expression
101 -- is a qualified expression or an aggregate.
103 procedure Expand_Array_Comparison
(N
: Node_Id
);
104 -- This routine handles expansion of the comparison operators (N_Op_Lt,
105 -- N_Op_Le, N_Op_Gt, N_Op_Ge) when operating on an array type. The basic
106 -- code for these operators is similar, differing only in the details of
107 -- the actual comparison call that is made. Special processing (call a
110 function Expand_Array_Equality
115 Typ
: Entity_Id
) return Node_Id
;
116 -- Expand an array equality into a call to a function implementing this
117 -- equality, and a call to it. Loc is the location for the generated nodes.
118 -- Lhs and Rhs are the array expressions to be compared. Bodies is a list
119 -- on which to attach bodies of local functions that are created in the
120 -- process. It is the responsibility of the caller to insert those bodies
121 -- at the right place. Nod provides the Sloc value for the generated code.
122 -- Normally the types used for the generated equality routine are taken
123 -- from Lhs and Rhs. However, in some situations of generated code, the
124 -- Etype fields of Lhs and Rhs are not set yet. In such cases, Typ supplies
125 -- the type to be used for the formal parameters.
127 procedure Expand_Boolean_Operator
(N
: Node_Id
);
128 -- Common expansion processing for Boolean operators (And, Or, Xor) for the
129 -- case of array type arguments.
131 procedure Expand_Nonbinary_Modular_Op
(N
: Node_Id
);
132 -- When generating C code, convert nonbinary modular arithmetic operations
133 -- into code that relies on the front-end expansion of operator Mod. No
134 -- expansion is performed if N is not a nonbinary modular operand.
136 procedure Expand_Short_Circuit_Operator
(N
: Node_Id
);
137 -- Common expansion processing for short-circuit boolean operators
139 procedure Expand_Compare_Minimize_Eliminate_Overflow
(N
: Node_Id
);
140 -- Deal with comparison in MINIMIZED/ELIMINATED overflow mode. This is
141 -- where we allow comparison of "out of range" values.
143 function Expand_Composite_Equality
148 Bodies
: List_Id
) return Node_Id
;
149 -- Local recursive function used to expand equality for nested composite
150 -- types. Used by Expand_Record/Array_Equality, Bodies is a list on which
151 -- to attach bodies of local functions that are created in the process. It
152 -- is the responsibility of the caller to insert those bodies at the right
153 -- place. Nod provides the Sloc value for generated code. Lhs and Rhs are
154 -- the left and right sides for the comparison, and Typ is the type of the
155 -- objects to compare.
157 procedure Expand_Concatenate
(Cnode
: Node_Id
; Opnds
: List_Id
);
158 -- Routine to expand concatenation of a sequence of two or more operands
159 -- (in the list Operands) and replace node Cnode with the result of the
160 -- concatenation. The operands can be of any appropriate type, and can
161 -- include both arrays and singleton elements.
163 procedure Expand_Membership_Minimize_Eliminate_Overflow
(N
: Node_Id
);
164 -- N is an N_In membership test mode, with the overflow check mode set to
165 -- MINIMIZED or ELIMINATED, and the type of the left operand is a signed
166 -- integer type. This is a case where top level processing is required to
167 -- handle overflow checks in subtrees.
169 procedure Fixup_Universal_Fixed_Operation
(N
: Node_Id
);
170 -- N is a N_Op_Divide or N_Op_Multiply node whose result is universal
171 -- fixed. We do not have such a type at runtime, so the purpose of this
172 -- routine is to find the real type by looking up the tree. We also
173 -- determine if the operation must be rounded.
175 function Has_Inferable_Discriminants
(N
: Node_Id
) return Boolean;
176 -- Ada 2005 (AI-216): A view of an Unchecked_Union object has inferable
177 -- discriminants if it has a constrained nominal type, unless the object
178 -- is a component of an enclosing Unchecked_Union object that is subject
179 -- to a per-object constraint and the enclosing object lacks inferable
182 -- An expression of an Unchecked_Union type has inferable discriminants
183 -- if it is either a name of an object with inferable discriminants or a
184 -- qualified expression whose subtype mark denotes a constrained subtype.
186 procedure Insert_Dereference_Action
(N
: Node_Id
);
187 -- N is an expression whose type is an access. When the type of the
188 -- associated storage pool is derived from Checked_Pool, generate a
189 -- call to the 'Dereference' primitive operation.
191 function Make_Array_Comparison_Op
193 Nod
: Node_Id
) return Node_Id
;
194 -- Comparisons between arrays are expanded in line. This function produces
195 -- the body of the implementation of (a > b), where a and b are one-
196 -- dimensional arrays of some discrete type. The original node is then
197 -- expanded into the appropriate call to this function. Nod provides the
198 -- Sloc value for the generated code.
200 function Make_Boolean_Array_Op
202 N
: Node_Id
) return Node_Id
;
203 -- Boolean operations on boolean arrays are expanded in line. This function
204 -- produce the body for the node N, which is (a and b), (a or b), or (a xor
205 -- b). It is used only the normal case and not the packed case. The type
206 -- involved, Typ, is the Boolean array type, and the logical operations in
207 -- the body are simple boolean operations. Note that Typ is always a
208 -- constrained type (the caller has ensured this by using
209 -- Convert_To_Actual_Subtype if necessary).
211 function Minimized_Eliminated_Overflow_Check
(N
: Node_Id
) return Boolean;
212 -- For signed arithmetic operations when the current overflow mode is
213 -- MINIMIZED or ELIMINATED, we must call Apply_Arithmetic_Overflow_Checks
214 -- as the first thing we do. We then return. We count on the recursive
215 -- apparatus for overflow checks to call us back with an equivalent
216 -- operation that is in CHECKED mode, avoiding a recursive entry into this
217 -- routine, and that is when we will proceed with the expansion of the
218 -- operator (e.g. converting X+0 to X, or X**2 to X*X). We cannot do
219 -- these optimizations without first making this check, since there may be
220 -- operands further down the tree that are relying on the recursive calls
221 -- triggered by the top level nodes to properly process overflow checking
222 -- and remaining expansion on these nodes. Note that this call back may be
223 -- skipped if the operation is done in Bignum mode but that's fine, since
224 -- the Bignum call takes care of everything.
226 procedure Optimize_Length_Comparison
(N
: Node_Id
);
227 -- Given an expression, if it is of the form X'Length op N (or the other
228 -- way round), where N is known at compile time to be 0 or 1, and X is a
229 -- simple entity, and op is a comparison operator, optimizes it into a
230 -- comparison of First and Last.
232 procedure Process_If_Case_Statements
(N
: Node_Id
; Stmts
: List_Id
);
233 -- Inspect and process statement list Stmt of if or case expression N for
234 -- transient objects. If such objects are found, the routine generates code
235 -- to clean them up when the context of the expression is evaluated.
237 procedure Process_Transient_In_Expression
241 -- Subsidiary routine to the expansion of expression_with_actions, if and
242 -- case expressions. Generate all necessary code to finalize a transient
243 -- object when the enclosing context is elaborated or evaluated. Obj_Decl
244 -- denotes the declaration of the transient object, which is usually the
245 -- result of a controlled function call. Expr denotes the expression with
246 -- actions, if expression, or case expression node. Stmts denotes the
247 -- statement list which contains Decl, either at the top level or within a
250 procedure Rewrite_Comparison
(N
: Node_Id
);
251 -- If N is the node for a comparison whose outcome can be determined at
252 -- compile time, then the node N can be rewritten with True or False. If
253 -- the outcome cannot be determined at compile time, the call has no
254 -- effect. If N is a type conversion, then this processing is applied to
255 -- its expression. If N is neither comparison nor a type conversion, the
256 -- call has no effect.
258 procedure Tagged_Membership
260 SCIL_Node
: out Node_Id
;
261 Result
: out Node_Id
);
262 -- Construct the expression corresponding to the tagged membership test.
263 -- Deals with a second operand being (or not) a class-wide type.
265 function Safe_In_Place_Array_Op
268 Op2
: Node_Id
) return Boolean;
269 -- In the context of an assignment, where the right-hand side is a boolean
270 -- operation on arrays, check whether operation can be performed in place.
272 procedure Unary_Op_Validity_Checks
(N
: Node_Id
);
273 pragma Inline
(Unary_Op_Validity_Checks
);
274 -- Performs validity checks for a unary operator
276 -------------------------------
277 -- Binary_Op_Validity_Checks --
278 -------------------------------
280 procedure Binary_Op_Validity_Checks
(N
: Node_Id
) is
282 if Validity_Checks_On
and Validity_Check_Operands
then
283 Ensure_Valid
(Left_Opnd
(N
));
284 Ensure_Valid
(Right_Opnd
(N
));
286 end Binary_Op_Validity_Checks
;
288 ------------------------------------
289 -- Build_Boolean_Array_Proc_Call --
290 ------------------------------------
292 procedure Build_Boolean_Array_Proc_Call
297 Loc
: constant Source_Ptr
:= Sloc
(N
);
298 Kind
: constant Node_Kind
:= Nkind
(Expression
(N
));
299 Target
: constant Node_Id
:=
300 Make_Attribute_Reference
(Loc
,
302 Attribute_Name
=> Name_Address
);
304 Arg1
: Node_Id
:= Op1
;
305 Arg2
: Node_Id
:= Op2
;
307 Proc_Name
: Entity_Id
;
310 if Kind
= N_Op_Not
then
311 if Nkind
(Op1
) in N_Binary_Op
then
313 -- Use negated version of the binary operators
315 if Nkind
(Op1
) = N_Op_And
then
316 Proc_Name
:= RTE
(RE_Vector_Nand
);
318 elsif Nkind
(Op1
) = N_Op_Or
then
319 Proc_Name
:= RTE
(RE_Vector_Nor
);
321 else pragma Assert
(Nkind
(Op1
) = N_Op_Xor
);
322 Proc_Name
:= RTE
(RE_Vector_Xor
);
326 Make_Procedure_Call_Statement
(Loc
,
327 Name
=> New_Occurrence_Of
(Proc_Name
, Loc
),
329 Parameter_Associations
=> New_List
(
331 Make_Attribute_Reference
(Loc
,
332 Prefix
=> Left_Opnd
(Op1
),
333 Attribute_Name
=> Name_Address
),
335 Make_Attribute_Reference
(Loc
,
336 Prefix
=> Right_Opnd
(Op1
),
337 Attribute_Name
=> Name_Address
),
339 Make_Attribute_Reference
(Loc
,
340 Prefix
=> Left_Opnd
(Op1
),
341 Attribute_Name
=> Name_Length
)));
344 Proc_Name
:= RTE
(RE_Vector_Not
);
347 Make_Procedure_Call_Statement
(Loc
,
348 Name
=> New_Occurrence_Of
(Proc_Name
, Loc
),
349 Parameter_Associations
=> New_List
(
352 Make_Attribute_Reference
(Loc
,
354 Attribute_Name
=> Name_Address
),
356 Make_Attribute_Reference
(Loc
,
358 Attribute_Name
=> Name_Length
)));
362 -- We use the following equivalences:
364 -- (not X) or (not Y) = not (X and Y) = Nand (X, Y)
365 -- (not X) and (not Y) = not (X or Y) = Nor (X, Y)
366 -- (not X) xor (not Y) = X xor Y
367 -- X xor (not Y) = not (X xor Y) = Nxor (X, Y)
369 if Nkind
(Op1
) = N_Op_Not
then
370 Arg1
:= Right_Opnd
(Op1
);
371 Arg2
:= Right_Opnd
(Op2
);
373 if Kind
= N_Op_And
then
374 Proc_Name
:= RTE
(RE_Vector_Nor
);
375 elsif Kind
= N_Op_Or
then
376 Proc_Name
:= RTE
(RE_Vector_Nand
);
378 Proc_Name
:= RTE
(RE_Vector_Xor
);
382 if Kind
= N_Op_And
then
383 Proc_Name
:= RTE
(RE_Vector_And
);
384 elsif Kind
= N_Op_Or
then
385 Proc_Name
:= RTE
(RE_Vector_Or
);
386 elsif Nkind
(Op2
) = N_Op_Not
then
387 Proc_Name
:= RTE
(RE_Vector_Nxor
);
388 Arg2
:= Right_Opnd
(Op2
);
390 Proc_Name
:= RTE
(RE_Vector_Xor
);
395 Make_Procedure_Call_Statement
(Loc
,
396 Name
=> New_Occurrence_Of
(Proc_Name
, Loc
),
397 Parameter_Associations
=> New_List
(
399 Make_Attribute_Reference
(Loc
,
401 Attribute_Name
=> Name_Address
),
402 Make_Attribute_Reference
(Loc
,
404 Attribute_Name
=> Name_Address
),
405 Make_Attribute_Reference
(Loc
,
407 Attribute_Name
=> Name_Length
)));
410 Rewrite
(N
, Call_Node
);
414 when RE_Not_Available
=>
416 end Build_Boolean_Array_Proc_Call
;
418 --------------------------------
419 -- Displace_Allocator_Pointer --
420 --------------------------------
422 procedure Displace_Allocator_Pointer
(N
: Node_Id
) is
423 Loc
: constant Source_Ptr
:= Sloc
(N
);
424 Orig_Node
: constant Node_Id
:= Original_Node
(N
);
430 -- Do nothing in case of VM targets: the virtual machine will handle
431 -- interfaces directly.
433 if not Tagged_Type_Expansion
then
437 pragma Assert
(Nkind
(N
) = N_Identifier
438 and then Nkind
(Orig_Node
) = N_Allocator
);
440 PtrT
:= Etype
(Orig_Node
);
441 Dtyp
:= Available_View
(Designated_Type
(PtrT
));
442 Etyp
:= Etype
(Expression
(Orig_Node
));
444 if Is_Class_Wide_Type
(Dtyp
) and then Is_Interface
(Dtyp
) then
446 -- If the type of the allocator expression is not an interface type
447 -- we can generate code to reference the record component containing
448 -- the pointer to the secondary dispatch table.
450 if not Is_Interface
(Etyp
) then
452 Saved_Typ
: constant Entity_Id
:= Etype
(Orig_Node
);
455 -- 1) Get access to the allocated object
458 Make_Explicit_Dereference
(Loc
, Relocate_Node
(N
)));
462 -- 2) Add the conversion to displace the pointer to reference
463 -- the secondary dispatch table.
465 Rewrite
(N
, Convert_To
(Dtyp
, Relocate_Node
(N
)));
466 Analyze_And_Resolve
(N
, Dtyp
);
468 -- 3) The 'access to the secondary dispatch table will be used
469 -- as the value returned by the allocator.
472 Make_Attribute_Reference
(Loc
,
473 Prefix
=> Relocate_Node
(N
),
474 Attribute_Name
=> Name_Access
));
475 Set_Etype
(N
, Saved_Typ
);
479 -- If the type of the allocator expression is an interface type we
480 -- generate a run-time call to displace "this" to reference the
481 -- component containing the pointer to the secondary dispatch table
482 -- or else raise Constraint_Error if the actual object does not
483 -- implement the target interface. This case corresponds to the
484 -- following example:
486 -- function Op (Obj : Iface_1'Class) return access Iface_2'Class is
488 -- return new Iface_2'Class'(Obj);
493 Unchecked_Convert_To
(PtrT
,
494 Make_Function_Call
(Loc
,
495 Name
=> New_Occurrence_Of
(RTE
(RE_Displace
), Loc
),
496 Parameter_Associations
=> New_List
(
497 Unchecked_Convert_To
(RTE
(RE_Address
),
503 (Access_Disp_Table
(Etype
(Base_Type
(Dtyp
))))),
505 Analyze_And_Resolve
(N
, PtrT
);
508 end Displace_Allocator_Pointer
;
510 ---------------------------------
511 -- Expand_Allocator_Expression --
512 ---------------------------------
514 procedure Expand_Allocator_Expression
(N
: Node_Id
) is
515 Loc
: constant Source_Ptr
:= Sloc
(N
);
516 Exp
: constant Node_Id
:= Expression
(Expression
(N
));
517 PtrT
: constant Entity_Id
:= Etype
(N
);
518 DesigT
: constant Entity_Id
:= Designated_Type
(PtrT
);
520 procedure Apply_Accessibility_Check
522 Built_In_Place
: Boolean := False);
523 -- Ada 2005 (AI-344): For an allocator with a class-wide designated
524 -- type, generate an accessibility check to verify that the level of the
525 -- type of the created object is not deeper than the level of the access
526 -- type. If the type of the qualified expression is class-wide, then
527 -- always generate the check (except in the case where it is known to be
528 -- unnecessary, see comment below). Otherwise, only generate the check
529 -- if the level of the qualified expression type is statically deeper
530 -- than the access type.
532 -- Although the static accessibility will generally have been performed
533 -- as a legality check, it won't have been done in cases where the
534 -- allocator appears in generic body, so a run-time check is needed in
535 -- general. One special case is when the access type is declared in the
536 -- same scope as the class-wide allocator, in which case the check can
537 -- never fail, so it need not be generated.
539 -- As an open issue, there seem to be cases where the static level
540 -- associated with the class-wide object's underlying type is not
541 -- sufficient to perform the proper accessibility check, such as for
542 -- allocators in nested subprograms or accept statements initialized by
543 -- class-wide formals when the actual originates outside at a deeper
544 -- static level. The nested subprogram case might require passing
545 -- accessibility levels along with class-wide parameters, and the task
546 -- case seems to be an actual gap in the language rules that needs to
547 -- be fixed by the ARG. ???
549 -------------------------------
550 -- Apply_Accessibility_Check --
551 -------------------------------
553 procedure Apply_Accessibility_Check
555 Built_In_Place
: Boolean := False)
557 Pool_Id
: constant Entity_Id
:= Associated_Storage_Pool
(PtrT
);
565 if Ada_Version
>= Ada_2005
566 and then Is_Class_Wide_Type
(DesigT
)
567 and then Tagged_Type_Expansion
568 and then not Scope_Suppress
.Suppress
(Accessibility_Check
)
570 (Type_Access_Level
(Etype
(Exp
)) > Type_Access_Level
(PtrT
)
572 (Is_Class_Wide_Type
(Etype
(Exp
))
573 and then Scope
(PtrT
) /= Current_Scope
))
575 -- If the allocator was built in place, Ref is already a reference
576 -- to the access object initialized to the result of the allocator
577 -- (see Exp_Ch6.Make_Build_In_Place_Call_In_Allocator). We call
578 -- Remove_Side_Effects for cases where the build-in-place call may
579 -- still be the prefix of the reference (to avoid generating
580 -- duplicate calls). Otherwise, it is the entity associated with
581 -- the object containing the address of the allocated object.
583 if Built_In_Place
then
584 Remove_Side_Effects
(Ref
);
585 Obj_Ref
:= New_Copy_Tree
(Ref
);
587 Obj_Ref
:= New_Occurrence_Of
(Ref
, Loc
);
590 -- For access to interface types we must generate code to displace
591 -- the pointer to the base of the object since the subsequent code
592 -- references components located in the TSD of the object (which
593 -- is associated with the primary dispatch table --see a-tags.ads)
594 -- and also generates code invoking Free, which requires also a
595 -- reference to the base of the unallocated object.
597 if Is_Interface
(DesigT
) and then Tagged_Type_Expansion
then
599 Unchecked_Convert_To
(Etype
(Obj_Ref
),
600 Make_Function_Call
(Loc
,
602 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
603 Parameter_Associations
=> New_List
(
604 Unchecked_Convert_To
(RTE
(RE_Address
),
605 New_Copy_Tree
(Obj_Ref
)))));
608 -- Step 1: Create the object clean up code
612 -- Deallocate the object if the accessibility check fails. This
613 -- is done only on targets or profiles that support deallocation.
617 if RTE_Available
(RE_Free
) then
618 Free_Stmt
:= Make_Free_Statement
(Loc
, New_Copy_Tree
(Obj_Ref
));
619 Set_Storage_Pool
(Free_Stmt
, Pool_Id
);
621 Append_To
(Stmts
, Free_Stmt
);
623 -- The target or profile cannot deallocate objects
629 -- Finalize the object if applicable. Generate:
631 -- [Deep_]Finalize (Obj_Ref.all);
633 if Needs_Finalization
(DesigT
)
634 and then not No_Heap_Finalization
(PtrT
)
639 Make_Explicit_Dereference
(Loc
, New_Copy
(Obj_Ref
)),
642 -- Guard against a missing [Deep_]Finalize when the designated
643 -- type was not properly frozen.
645 if No
(Fin_Call
) then
646 Fin_Call
:= Make_Null_Statement
(Loc
);
649 -- When the target or profile supports deallocation, wrap the
650 -- finalization call in a block to ensure proper deallocation
651 -- even if finalization fails. Generate:
661 if Present
(Free_Stmt
) then
663 Make_Block_Statement
(Loc
,
664 Handled_Statement_Sequence
=>
665 Make_Handled_Sequence_Of_Statements
(Loc
,
666 Statements
=> New_List
(Fin_Call
),
668 Exception_Handlers
=> New_List
(
669 Make_Exception_Handler
(Loc
,
670 Exception_Choices
=> New_List
(
671 Make_Others_Choice
(Loc
)),
672 Statements
=> New_List
(
673 New_Copy_Tree
(Free_Stmt
),
674 Make_Raise_Statement
(Loc
))))));
677 Prepend_To
(Stmts
, Fin_Call
);
680 -- Signal the accessibility failure through a Program_Error
683 Make_Raise_Program_Error
(Loc
,
684 Condition
=> New_Occurrence_Of
(Standard_True
, Loc
),
685 Reason
=> PE_Accessibility_Check_Failed
));
687 -- Step 2: Create the accessibility comparison
693 Make_Attribute_Reference
(Loc
,
695 Attribute_Name
=> Name_Tag
);
697 -- For tagged types, determine the accessibility level by looking
698 -- at the type specific data of the dispatch table. Generate:
700 -- Type_Specific_Data (Address (Ref'Tag)).Access_Level
702 if Tagged_Type_Expansion
then
703 Cond
:= Build_Get_Access_Level
(Loc
, Obj_Ref
);
705 -- Use a runtime call to determine the accessibility level when
706 -- compiling on virtual machine targets. Generate:
708 -- Get_Access_Level (Ref'Tag)
712 Make_Function_Call
(Loc
,
714 New_Occurrence_Of
(RTE
(RE_Get_Access_Level
), Loc
),
715 Parameter_Associations
=> New_List
(Obj_Ref
));
722 Make_Integer_Literal
(Loc
, Type_Access_Level
(PtrT
)));
724 -- Due to the complexity and side effects of the check, utilize an
725 -- if statement instead of the regular Program_Error circuitry.
728 Make_Implicit_If_Statement
(N
,
730 Then_Statements
=> Stmts
));
732 end Apply_Accessibility_Check
;
736 Aggr_In_Place
: constant Boolean := Is_Delayed_Aggregate
(Exp
);
737 Indic
: constant Node_Id
:= Subtype_Mark
(Expression
(N
));
738 T
: constant Entity_Id
:= Entity
(Indic
);
741 Tag_Assign
: Node_Id
;
745 TagT
: Entity_Id
:= Empty
;
746 -- Type used as source for tag assignment
748 TagR
: Node_Id
:= Empty
;
749 -- Target reference for tag assignment
751 -- Start of processing for Expand_Allocator_Expression
754 -- Handle call to C++ constructor
756 if Is_CPP_Constructor_Call
(Exp
) then
757 Make_CPP_Constructor_Call_In_Allocator
759 Function_Call
=> Exp
);
763 -- In the case of an Ada 2012 allocator whose initial value comes from a
764 -- function call, pass "the accessibility level determined by the point
765 -- of call" (AI05-0234) to the function. Conceptually, this belongs in
766 -- Expand_Call but it couldn't be done there (because the Etype of the
767 -- allocator wasn't set then) so we generate the parameter here. See
768 -- the Boolean variable Defer in (a block within) Expand_Call.
770 if Ada_Version
>= Ada_2012
and then Nkind
(Exp
) = N_Function_Call
then
775 if Nkind
(Name
(Exp
)) = N_Explicit_Dereference
then
776 Subp
:= Designated_Type
(Etype
(Prefix
(Name
(Exp
))));
778 Subp
:= Entity
(Name
(Exp
));
781 Subp
:= Ultimate_Alias
(Subp
);
783 if Present
(Extra_Accessibility_Of_Result
(Subp
)) then
784 Add_Extra_Actual_To_Call
785 (Subprogram_Call
=> Exp
,
786 Extra_Formal
=> Extra_Accessibility_Of_Result
(Subp
),
787 Extra_Actual
=> Dynamic_Accessibility_Level
(PtrT
));
792 -- Case of tagged type or type requiring finalization
794 if Is_Tagged_Type
(T
) or else Needs_Finalization
(T
) then
796 -- Ada 2005 (AI-318-02): If the initialization expression is a call
797 -- to a build-in-place function, then access to the allocated object
798 -- must be passed to the function.
800 if Is_Build_In_Place_Function_Call
(Exp
) then
801 Make_Build_In_Place_Call_In_Allocator
(N
, Exp
);
802 Apply_Accessibility_Check
(N
, Built_In_Place
=> True);
805 -- Ada 2005 (AI-318-02): Specialization of the previous case for
806 -- expressions containing a build-in-place function call whose
807 -- returned object covers interface types, and Expr has calls to
808 -- Ada.Tags.Displace to displace the pointer to the returned build-
809 -- in-place object to reference the secondary dispatch table of a
810 -- covered interface type.
812 elsif Present
(Unqual_BIP_Iface_Function_Call
(Exp
)) then
813 Make_Build_In_Place_Iface_Call_In_Allocator
(N
, Exp
);
814 Apply_Accessibility_Check
(N
, Built_In_Place
=> True);
818 -- Actions inserted before:
819 -- Temp : constant ptr_T := new T'(Expression);
820 -- Temp._tag = T'tag; -- when not class-wide
821 -- [Deep_]Adjust (Temp.all);
823 -- We analyze by hand the new internal allocator to avoid any
824 -- recursion and inappropriate call to Initialize.
826 -- We don't want to remove side effects when the expression must be
827 -- built in place. In the case of a build-in-place function call,
828 -- that could lead to a duplication of the call, which was already
829 -- substituted for the allocator.
831 if not Aggr_In_Place
then
832 Remove_Side_Effects
(Exp
);
835 Temp
:= Make_Temporary
(Loc
, 'P', N
);
837 -- For a class wide allocation generate the following code:
839 -- type Equiv_Record is record ... end record;
840 -- implicit subtype CW is <Class_Wide_Subytpe>;
841 -- temp : PtrT := new CW'(CW!(expr));
843 if Is_Class_Wide_Type
(T
) then
844 Expand_Subtype_From_Expr
(Empty
, T
, Indic
, Exp
);
846 -- Ada 2005 (AI-251): If the expression is a class-wide interface
847 -- object we generate code to move up "this" to reference the
848 -- base of the object before allocating the new object.
850 -- Note that Exp'Address is recursively expanded into a call
851 -- to Base_Address (Exp.Tag)
853 if Is_Class_Wide_Type
(Etype
(Exp
))
854 and then Is_Interface
(Etype
(Exp
))
855 and then Tagged_Type_Expansion
859 Unchecked_Convert_To
(Entity
(Indic
),
860 Make_Explicit_Dereference
(Loc
,
861 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
862 Make_Attribute_Reference
(Loc
,
864 Attribute_Name
=> Name_Address
)))));
868 Unchecked_Convert_To
(Entity
(Indic
), Exp
));
871 Analyze_And_Resolve
(Expression
(N
), Entity
(Indic
));
874 -- Processing for allocators returning non-interface types
876 if not Is_Interface
(Directly_Designated_Type
(PtrT
)) then
877 if Aggr_In_Place
then
879 Make_Object_Declaration
(Loc
,
880 Defining_Identifier
=> Temp
,
881 Object_Definition
=> New_Occurrence_Of
(PtrT
, Loc
),
885 New_Occurrence_Of
(Etype
(Exp
), Loc
)));
887 -- Copy the Comes_From_Source flag for the allocator we just
888 -- built, since logically this allocator is a replacement of
889 -- the original allocator node. This is for proper handling of
890 -- restriction No_Implicit_Heap_Allocations.
892 Set_Comes_From_Source
893 (Expression
(Temp_Decl
), Comes_From_Source
(N
));
895 Set_No_Initialization
(Expression
(Temp_Decl
));
896 Insert_Action
(N
, Temp_Decl
);
898 Build_Allocate_Deallocate_Proc
(Temp_Decl
, True);
899 Convert_Aggr_In_Allocator
(N
, Temp_Decl
, Exp
);
902 Node
:= Relocate_Node
(N
);
906 Make_Object_Declaration
(Loc
,
907 Defining_Identifier
=> Temp
,
908 Constant_Present
=> True,
909 Object_Definition
=> New_Occurrence_Of
(PtrT
, Loc
),
912 Insert_Action
(N
, Temp_Decl
);
913 Build_Allocate_Deallocate_Proc
(Temp_Decl
, True);
916 -- Ada 2005 (AI-251): Handle allocators whose designated type is an
917 -- interface type. In this case we use the type of the qualified
918 -- expression to allocate the object.
922 Def_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
927 Make_Full_Type_Declaration
(Loc
,
928 Defining_Identifier
=> Def_Id
,
930 Make_Access_To_Object_Definition
(Loc
,
932 Null_Exclusion_Present
=> False,
934 Is_Access_Constant
(Etype
(N
)),
935 Subtype_Indication
=>
936 New_Occurrence_Of
(Etype
(Exp
), Loc
)));
938 Insert_Action
(N
, New_Decl
);
940 -- Inherit the allocation-related attributes from the original
943 Set_Finalization_Master
944 (Def_Id
, Finalization_Master
(PtrT
));
946 Set_Associated_Storage_Pool
947 (Def_Id
, Associated_Storage_Pool
(PtrT
));
949 -- Declare the object using the previous type declaration
951 if Aggr_In_Place
then
953 Make_Object_Declaration
(Loc
,
954 Defining_Identifier
=> Temp
,
955 Object_Definition
=> New_Occurrence_Of
(Def_Id
, Loc
),
958 New_Occurrence_Of
(Etype
(Exp
), Loc
)));
960 -- Copy the Comes_From_Source flag for the allocator we just
961 -- built, since logically this allocator is a replacement of
962 -- the original allocator node. This is for proper handling
963 -- of restriction No_Implicit_Heap_Allocations.
965 Set_Comes_From_Source
966 (Expression
(Temp_Decl
), Comes_From_Source
(N
));
968 Set_No_Initialization
(Expression
(Temp_Decl
));
969 Insert_Action
(N
, Temp_Decl
);
971 Build_Allocate_Deallocate_Proc
(Temp_Decl
, True);
972 Convert_Aggr_In_Allocator
(N
, Temp_Decl
, Exp
);
975 Node
:= Relocate_Node
(N
);
979 Make_Object_Declaration
(Loc
,
980 Defining_Identifier
=> Temp
,
981 Constant_Present
=> True,
982 Object_Definition
=> New_Occurrence_Of
(Def_Id
, Loc
),
985 Insert_Action
(N
, Temp_Decl
);
986 Build_Allocate_Deallocate_Proc
(Temp_Decl
, True);
989 -- Generate an additional object containing the address of the
990 -- returned object. The type of this second object declaration
991 -- is the correct type required for the common processing that
992 -- is still performed by this subprogram. The displacement of
993 -- this pointer to reference the component associated with the
994 -- interface type will be done at the end of common processing.
997 Make_Object_Declaration
(Loc
,
998 Defining_Identifier
=> Make_Temporary
(Loc
, 'P'),
999 Object_Definition
=> New_Occurrence_Of
(PtrT
, Loc
),
1001 Unchecked_Convert_To
(PtrT
,
1002 New_Occurrence_Of
(Temp
, Loc
)));
1004 Insert_Action
(N
, New_Decl
);
1006 Temp_Decl
:= New_Decl
;
1007 Temp
:= Defining_Identifier
(New_Decl
);
1011 -- Generate the tag assignment
1013 -- Suppress the tag assignment for VM targets because VM tags are
1014 -- represented implicitly in objects.
1016 if not Tagged_Type_Expansion
then
1019 -- Ada 2005 (AI-251): Suppress the tag assignment with class-wide
1020 -- interface objects because in this case the tag does not change.
1022 elsif Is_Interface
(Directly_Designated_Type
(Etype
(N
))) then
1023 pragma Assert
(Is_Class_Wide_Type
1024 (Directly_Designated_Type
(Etype
(N
))));
1027 elsif Is_Tagged_Type
(T
) and then not Is_Class_Wide_Type
(T
) then
1029 TagR
:= New_Occurrence_Of
(Temp
, Loc
);
1031 elsif Is_Private_Type
(T
)
1032 and then Is_Tagged_Type
(Underlying_Type
(T
))
1034 TagT
:= Underlying_Type
(T
);
1036 Unchecked_Convert_To
(Underlying_Type
(T
),
1037 Make_Explicit_Dereference
(Loc
,
1038 Prefix
=> New_Occurrence_Of
(Temp
, Loc
)));
1041 if Present
(TagT
) then
1043 Full_T
: constant Entity_Id
:= Underlying_Type
(TagT
);
1047 Make_Assignment_Statement
(Loc
,
1049 Make_Selected_Component
(Loc
,
1053 (First_Tag_Component
(Full_T
), Loc
)),
1056 Unchecked_Convert_To
(RTE
(RE_Tag
),
1059 (First_Elmt
(Access_Disp_Table
(Full_T
))), Loc
)));
1062 -- The previous assignment has to be done in any case
1064 Set_Assignment_OK
(Name
(Tag_Assign
));
1065 Insert_Action
(N
, Tag_Assign
);
1068 -- Generate an Adjust call if the object will be moved. In Ada 2005,
1069 -- the object may be inherently limited, in which case there is no
1070 -- Adjust procedure, and the object is built in place. In Ada 95, the
1071 -- object can be limited but not inherently limited if this allocator
1072 -- came from a return statement (we're allocating the result on the
1073 -- secondary stack). In that case, the object will be moved, so we do
1074 -- want to Adjust. However, if it's a nonlimited build-in-place
1075 -- function call, Adjust is not wanted.
1077 if Needs_Finalization
(DesigT
)
1078 and then Needs_Finalization
(T
)
1079 and then not Aggr_In_Place
1080 and then not Is_Limited_View
(T
)
1081 and then not Alloc_For_BIP_Return
(N
)
1082 and then not Is_Build_In_Place_Function_Call
(Expression
(N
))
1084 -- An unchecked conversion is needed in the classwide case because
1085 -- the designated type can be an ancestor of the subtype mark of
1091 Unchecked_Convert_To
(T
,
1092 Make_Explicit_Dereference
(Loc
,
1093 Prefix
=> New_Occurrence_Of
(Temp
, Loc
))),
1096 if Present
(Adj_Call
) then
1097 Insert_Action
(N
, Adj_Call
);
1101 -- Note: the accessibility check must be inserted after the call to
1102 -- [Deep_]Adjust to ensure proper completion of the assignment.
1104 Apply_Accessibility_Check
(Temp
);
1106 Rewrite
(N
, New_Occurrence_Of
(Temp
, Loc
));
1107 Analyze_And_Resolve
(N
, PtrT
);
1109 -- Ada 2005 (AI-251): Displace the pointer to reference the record
1110 -- component containing the secondary dispatch table of the interface
1113 if Is_Interface
(Directly_Designated_Type
(PtrT
)) then
1114 Displace_Allocator_Pointer
(N
);
1117 -- Always force the generation of a temporary for aggregates when
1118 -- generating C code, to simplify the work in the code generator.
1121 or else (Modify_Tree_For_C
and then Nkind
(Exp
) = N_Aggregate
)
1123 Temp
:= Make_Temporary
(Loc
, 'P', N
);
1125 Make_Object_Declaration
(Loc
,
1126 Defining_Identifier
=> Temp
,
1127 Object_Definition
=> New_Occurrence_Of
(PtrT
, Loc
),
1129 Make_Allocator
(Loc
,
1130 Expression
=> New_Occurrence_Of
(Etype
(Exp
), Loc
)));
1132 -- Copy the Comes_From_Source flag for the allocator we just built,
1133 -- since logically this allocator is a replacement of the original
1134 -- allocator node. This is for proper handling of restriction
1135 -- No_Implicit_Heap_Allocations.
1137 Set_Comes_From_Source
1138 (Expression
(Temp_Decl
), Comes_From_Source
(N
));
1140 Set_No_Initialization
(Expression
(Temp_Decl
));
1141 Insert_Action
(N
, Temp_Decl
);
1143 Build_Allocate_Deallocate_Proc
(Temp_Decl
, True);
1144 Convert_Aggr_In_Allocator
(N
, Temp_Decl
, Exp
);
1146 Rewrite
(N
, New_Occurrence_Of
(Temp
, Loc
));
1147 Analyze_And_Resolve
(N
, PtrT
);
1149 elsif Is_Access_Type
(T
) and then Can_Never_Be_Null
(T
) then
1150 Install_Null_Excluding_Check
(Exp
);
1152 elsif Is_Access_Type
(DesigT
)
1153 and then Nkind
(Exp
) = N_Allocator
1154 and then Nkind
(Expression
(Exp
)) /= N_Qualified_Expression
1156 -- Apply constraint to designated subtype indication
1158 Apply_Constraint_Check
1159 (Expression
(Exp
), Designated_Type
(DesigT
), No_Sliding
=> True);
1161 if Nkind
(Expression
(Exp
)) = N_Raise_Constraint_Error
then
1163 -- Propagate constraint_error to enclosing allocator
1165 Rewrite
(Exp
, New_Copy
(Expression
(Exp
)));
1169 Build_Allocate_Deallocate_Proc
(N
, True);
1172 -- type A is access T1;
1173 -- X : A := new T2'(...);
1174 -- T1 and T2 can be different subtypes, and we might need to check
1175 -- both constraints. First check against the type of the qualified
1178 Apply_Constraint_Check
(Exp
, T
, No_Sliding
=> True);
1180 if Do_Range_Check
(Exp
) then
1181 Generate_Range_Check
(Exp
, DesigT
, CE_Range_Check_Failed
);
1184 -- A check is also needed in cases where the designated subtype is
1185 -- constrained and differs from the subtype given in the qualified
1186 -- expression. Note that the check on the qualified expression does
1187 -- not allow sliding, but this check does (a relaxation from Ada 83).
1189 if Is_Constrained
(DesigT
)
1190 and then not Subtypes_Statically_Match
(T
, DesigT
)
1192 Apply_Constraint_Check
1193 (Exp
, DesigT
, No_Sliding
=> False);
1195 if Do_Range_Check
(Exp
) then
1196 Generate_Range_Check
(Exp
, DesigT
, CE_Range_Check_Failed
);
1200 -- For an access to unconstrained packed array, GIGI needs to see an
1201 -- expression with a constrained subtype in order to compute the
1202 -- proper size for the allocator.
1204 if Is_Array_Type
(T
)
1205 and then not Is_Constrained
(T
)
1206 and then Is_Packed
(T
)
1209 ConstrT
: constant Entity_Id
:= Make_Temporary
(Loc
, 'A');
1210 Internal_Exp
: constant Node_Id
:= Relocate_Node
(Exp
);
1213 Make_Subtype_Declaration
(Loc
,
1214 Defining_Identifier
=> ConstrT
,
1215 Subtype_Indication
=>
1216 Make_Subtype_From_Expr
(Internal_Exp
, T
)));
1217 Freeze_Itype
(ConstrT
, Exp
);
1218 Rewrite
(Exp
, OK_Convert_To
(ConstrT
, Internal_Exp
));
1222 -- Ada 2005 (AI-318-02): If the initialization expression is a call
1223 -- to a build-in-place function, then access to the allocated object
1224 -- must be passed to the function.
1226 if Is_Build_In_Place_Function_Call
(Exp
) then
1227 Make_Build_In_Place_Call_In_Allocator
(N
, Exp
);
1232 when RE_Not_Available
=>
1234 end Expand_Allocator_Expression
;
1236 -----------------------------
1237 -- Expand_Array_Comparison --
1238 -----------------------------
1240 -- Expansion is only required in the case of array types. For the unpacked
1241 -- case, an appropriate runtime routine is called. For packed cases, and
1242 -- also in some other cases where a runtime routine cannot be called, the
1243 -- form of the expansion is:
1245 -- [body for greater_nn; boolean_expression]
1247 -- The body is built by Make_Array_Comparison_Op, and the form of the
1248 -- Boolean expression depends on the operator involved.
1250 procedure Expand_Array_Comparison
(N
: Node_Id
) is
1251 Loc
: constant Source_Ptr
:= Sloc
(N
);
1252 Op1
: Node_Id
:= Left_Opnd
(N
);
1253 Op2
: Node_Id
:= Right_Opnd
(N
);
1254 Typ1
: constant Entity_Id
:= Base_Type
(Etype
(Op1
));
1255 Ctyp
: constant Entity_Id
:= Component_Type
(Typ1
);
1258 Func_Body
: Node_Id
;
1259 Func_Name
: Entity_Id
;
1263 Byte_Addressable
: constant Boolean := System_Storage_Unit
= Byte
'Size;
1264 -- True for byte addressable target
1266 function Length_Less_Than_4
(Opnd
: Node_Id
) return Boolean;
1267 -- Returns True if the length of the given operand is known to be less
1268 -- than 4. Returns False if this length is known to be four or greater
1269 -- or is not known at compile time.
1271 ------------------------
1272 -- Length_Less_Than_4 --
1273 ------------------------
1275 function Length_Less_Than_4
(Opnd
: Node_Id
) return Boolean is
1276 Otyp
: constant Entity_Id
:= Etype
(Opnd
);
1279 if Ekind
(Otyp
) = E_String_Literal_Subtype
then
1280 return String_Literal_Length
(Otyp
) < 4;
1284 Ityp
: constant Entity_Id
:= Etype
(First_Index
(Otyp
));
1285 Lo
: constant Node_Id
:= Type_Low_Bound
(Ityp
);
1286 Hi
: constant Node_Id
:= Type_High_Bound
(Ityp
);
1291 if Compile_Time_Known_Value
(Lo
) then
1292 Lov
:= Expr_Value
(Lo
);
1297 if Compile_Time_Known_Value
(Hi
) then
1298 Hiv
:= Expr_Value
(Hi
);
1303 return Hiv
< Lov
+ 3;
1306 end Length_Less_Than_4
;
1308 -- Start of processing for Expand_Array_Comparison
1311 -- Deal first with unpacked case, where we can call a runtime routine
1312 -- except that we avoid this for targets for which are not addressable
1315 if not Is_Bit_Packed_Array
(Typ1
)
1316 and then Byte_Addressable
1318 -- The call we generate is:
1320 -- Compare_Array_xn[_Unaligned]
1321 -- (left'address, right'address, left'length, right'length) <op> 0
1323 -- x = U for unsigned, S for signed
1324 -- n = 8,16,32,64 for component size
1325 -- Add _Unaligned if length < 4 and component size is 8.
1326 -- <op> is the standard comparison operator
1328 if Component_Size
(Typ1
) = 8 then
1329 if Length_Less_Than_4
(Op1
)
1331 Length_Less_Than_4
(Op2
)
1333 if Is_Unsigned_Type
(Ctyp
) then
1334 Comp
:= RE_Compare_Array_U8_Unaligned
;
1336 Comp
:= RE_Compare_Array_S8_Unaligned
;
1340 if Is_Unsigned_Type
(Ctyp
) then
1341 Comp
:= RE_Compare_Array_U8
;
1343 Comp
:= RE_Compare_Array_S8
;
1347 elsif Component_Size
(Typ1
) = 16 then
1348 if Is_Unsigned_Type
(Ctyp
) then
1349 Comp
:= RE_Compare_Array_U16
;
1351 Comp
:= RE_Compare_Array_S16
;
1354 elsif Component_Size
(Typ1
) = 32 then
1355 if Is_Unsigned_Type
(Ctyp
) then
1356 Comp
:= RE_Compare_Array_U32
;
1358 Comp
:= RE_Compare_Array_S32
;
1361 else pragma Assert
(Component_Size
(Typ1
) = 64);
1362 if Is_Unsigned_Type
(Ctyp
) then
1363 Comp
:= RE_Compare_Array_U64
;
1365 Comp
:= RE_Compare_Array_S64
;
1369 if RTE_Available
(Comp
) then
1371 -- Expand to a call only if the runtime function is available,
1372 -- otherwise fall back to inline code.
1374 Remove_Side_Effects
(Op1
, Name_Req
=> True);
1375 Remove_Side_Effects
(Op2
, Name_Req
=> True);
1378 Make_Function_Call
(Sloc
(Op1
),
1379 Name
=> New_Occurrence_Of
(RTE
(Comp
), Loc
),
1381 Parameter_Associations
=> New_List
(
1382 Make_Attribute_Reference
(Loc
,
1383 Prefix
=> Relocate_Node
(Op1
),
1384 Attribute_Name
=> Name_Address
),
1386 Make_Attribute_Reference
(Loc
,
1387 Prefix
=> Relocate_Node
(Op2
),
1388 Attribute_Name
=> Name_Address
),
1390 Make_Attribute_Reference
(Loc
,
1391 Prefix
=> Relocate_Node
(Op1
),
1392 Attribute_Name
=> Name_Length
),
1394 Make_Attribute_Reference
(Loc
,
1395 Prefix
=> Relocate_Node
(Op2
),
1396 Attribute_Name
=> Name_Length
))));
1399 Make_Integer_Literal
(Sloc
(Op2
),
1402 Analyze_And_Resolve
(Op1
, Standard_Integer
);
1403 Analyze_And_Resolve
(Op2
, Standard_Integer
);
1408 -- Cases where we cannot make runtime call
1410 -- For (a <= b) we convert to not (a > b)
1412 if Chars
(N
) = Name_Op_Le
then
1418 Right_Opnd
=> Op2
)));
1419 Analyze_And_Resolve
(N
, Standard_Boolean
);
1422 -- For < the Boolean expression is
1423 -- greater__nn (op2, op1)
1425 elsif Chars
(N
) = Name_Op_Lt
then
1426 Func_Body
:= Make_Array_Comparison_Op
(Typ1
, N
);
1430 Op1
:= Right_Opnd
(N
);
1431 Op2
:= Left_Opnd
(N
);
1433 -- For (a >= b) we convert to not (a < b)
1435 elsif Chars
(N
) = Name_Op_Ge
then
1441 Right_Opnd
=> Op2
)));
1442 Analyze_And_Resolve
(N
, Standard_Boolean
);
1445 -- For > the Boolean expression is
1446 -- greater__nn (op1, op2)
1449 pragma Assert
(Chars
(N
) = Name_Op_Gt
);
1450 Func_Body
:= Make_Array_Comparison_Op
(Typ1
, N
);
1453 Func_Name
:= Defining_Unit_Name
(Specification
(Func_Body
));
1455 Make_Function_Call
(Loc
,
1456 Name
=> New_Occurrence_Of
(Func_Name
, Loc
),
1457 Parameter_Associations
=> New_List
(Op1
, Op2
));
1459 Insert_Action
(N
, Func_Body
);
1461 Analyze_And_Resolve
(N
, Standard_Boolean
);
1462 end Expand_Array_Comparison
;
1464 ---------------------------
1465 -- Expand_Array_Equality --
1466 ---------------------------
1468 -- Expand an equality function for multi-dimensional arrays. Here is an
1469 -- example of such a function for Nb_Dimension = 2
1471 -- function Enn (A : atyp; B : btyp) return boolean is
1473 -- if (A'length (1) = 0 or else A'length (2) = 0)
1475 -- (B'length (1) = 0 or else B'length (2) = 0)
1477 -- return True; -- RM 4.5.2(22)
1480 -- if A'length (1) /= B'length (1)
1482 -- A'length (2) /= B'length (2)
1484 -- return False; -- RM 4.5.2(23)
1488 -- A1 : Index_T1 := A'first (1);
1489 -- B1 : Index_T1 := B'first (1);
1493 -- A2 : Index_T2 := A'first (2);
1494 -- B2 : Index_T2 := B'first (2);
1497 -- if A (A1, A2) /= B (B1, B2) then
1501 -- exit when A2 = A'last (2);
1502 -- A2 := Index_T2'succ (A2);
1503 -- B2 := Index_T2'succ (B2);
1507 -- exit when A1 = A'last (1);
1508 -- A1 := Index_T1'succ (A1);
1509 -- B1 := Index_T1'succ (B1);
1516 -- Note on the formal types used (atyp and btyp). If either of the arrays
1517 -- is of a private type, we use the underlying type, and do an unchecked
1518 -- conversion of the actual. If either of the arrays has a bound depending
1519 -- on a discriminant, then we use the base type since otherwise we have an
1520 -- escaped discriminant in the function.
1522 -- If both arrays are constrained and have the same bounds, we can generate
1523 -- a loop with an explicit iteration scheme using a 'Range attribute over
1526 function Expand_Array_Equality
1531 Typ
: Entity_Id
) return Node_Id
1533 Loc
: constant Source_Ptr
:= Sloc
(Nod
);
1534 Decls
: constant List_Id
:= New_List
;
1535 Index_List1
: constant List_Id
:= New_List
;
1536 Index_List2
: constant List_Id
:= New_List
;
1540 Func_Name
: Entity_Id
;
1541 Func_Body
: Node_Id
;
1543 A
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uA
);
1544 B
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uB
);
1548 -- The parameter types to be used for the formals
1553 Num
: Int
) return Node_Id
;
1554 -- This builds the attribute reference Arr'Nam (Expr)
1556 function Component_Equality
(Typ
: Entity_Id
) return Node_Id
;
1557 -- Create one statement to compare corresponding components, designated
1558 -- by a full set of indexes.
1560 function Get_Arg_Type
(N
: Node_Id
) return Entity_Id
;
1561 -- Given one of the arguments, computes the appropriate type to be used
1562 -- for that argument in the corresponding function formal
1564 function Handle_One_Dimension
1566 Index
: Node_Id
) return Node_Id
;
1567 -- This procedure returns the following code
1570 -- Bn : Index_T := B'First (N);
1574 -- exit when An = A'Last (N);
1575 -- An := Index_T'Succ (An)
1576 -- Bn := Index_T'Succ (Bn)
1580 -- If both indexes are constrained and identical, the procedure
1581 -- returns a simpler loop:
1583 -- for An in A'Range (N) loop
1587 -- N is the dimension for which we are generating a loop. Index is the
1588 -- N'th index node, whose Etype is Index_Type_n in the above code. The
1589 -- xxx statement is either the loop or declare for the next dimension
1590 -- or if this is the last dimension the comparison of corresponding
1591 -- components of the arrays.
1593 -- The actual way the code works is to return the comparison of
1594 -- corresponding components for the N+1 call. That's neater.
1596 function Test_Empty_Arrays
return Node_Id
;
1597 -- This function constructs the test for both arrays being empty
1598 -- (A'length (1) = 0 or else A'length (2) = 0 or else ...)
1600 -- (B'length (1) = 0 or else B'length (2) = 0 or else ...)
1602 function Test_Lengths_Correspond
return Node_Id
;
1603 -- This function constructs the test for arrays having different lengths
1604 -- in at least one index position, in which case the resulting code is:
1606 -- A'length (1) /= B'length (1)
1608 -- A'length (2) /= B'length (2)
1619 Num
: Int
) return Node_Id
1623 Make_Attribute_Reference
(Loc
,
1624 Attribute_Name
=> Nam
,
1625 Prefix
=> New_Occurrence_Of
(Arr
, Loc
),
1626 Expressions
=> New_List
(Make_Integer_Literal
(Loc
, Num
)));
1629 ------------------------
1630 -- Component_Equality --
1631 ------------------------
1633 function Component_Equality
(Typ
: Entity_Id
) return Node_Id
is
1638 -- if a(i1...) /= b(j1...) then return false; end if;
1641 Make_Indexed_Component
(Loc
,
1642 Prefix
=> Make_Identifier
(Loc
, Chars
(A
)),
1643 Expressions
=> Index_List1
);
1646 Make_Indexed_Component
(Loc
,
1647 Prefix
=> Make_Identifier
(Loc
, Chars
(B
)),
1648 Expressions
=> Index_List2
);
1650 Test
:= Expand_Composite_Equality
1651 (Nod
, Component_Type
(Typ
), L
, R
, Decls
);
1653 -- If some (sub)component is an unchecked_union, the whole operation
1654 -- will raise program error.
1656 if Nkind
(Test
) = N_Raise_Program_Error
then
1658 -- This node is going to be inserted at a location where a
1659 -- statement is expected: clear its Etype so analysis will set
1660 -- it to the expected Standard_Void_Type.
1662 Set_Etype
(Test
, Empty
);
1667 Make_Implicit_If_Statement
(Nod
,
1668 Condition
=> Make_Op_Not
(Loc
, Right_Opnd
=> Test
),
1669 Then_Statements
=> New_List
(
1670 Make_Simple_Return_Statement
(Loc
,
1671 Expression
=> New_Occurrence_Of
(Standard_False
, Loc
))));
1673 end Component_Equality
;
1679 function Get_Arg_Type
(N
: Node_Id
) return Entity_Id
is
1690 T
:= Underlying_Type
(T
);
1692 X
:= First_Index
(T
);
1693 while Present
(X
) loop
1694 if Denotes_Discriminant
(Type_Low_Bound
(Etype
(X
)))
1696 Denotes_Discriminant
(Type_High_Bound
(Etype
(X
)))
1709 --------------------------
1710 -- Handle_One_Dimension --
1711 ---------------------------
1713 function Handle_One_Dimension
1715 Index
: Node_Id
) return Node_Id
1717 Need_Separate_Indexes
: constant Boolean :=
1718 Ltyp
/= Rtyp
or else not Is_Constrained
(Ltyp
);
1719 -- If the index types are identical, and we are working with
1720 -- constrained types, then we can use the same index for both
1723 An
: constant Entity_Id
:= Make_Temporary
(Loc
, 'A');
1726 Index_T
: Entity_Id
;
1731 if N
> Number_Dimensions
(Ltyp
) then
1732 return Component_Equality
(Ltyp
);
1735 -- Case where we generate a loop
1737 Index_T
:= Base_Type
(Etype
(Index
));
1739 if Need_Separate_Indexes
then
1740 Bn
:= Make_Temporary
(Loc
, 'B');
1745 Append
(New_Occurrence_Of
(An
, Loc
), Index_List1
);
1746 Append
(New_Occurrence_Of
(Bn
, Loc
), Index_List2
);
1748 Stm_List
:= New_List
(
1749 Handle_One_Dimension
(N
+ 1, Next_Index
(Index
)));
1751 if Need_Separate_Indexes
then
1753 -- Generate guard for loop, followed by increments of indexes
1755 Append_To
(Stm_List
,
1756 Make_Exit_Statement
(Loc
,
1759 Left_Opnd
=> New_Occurrence_Of
(An
, Loc
),
1760 Right_Opnd
=> Arr_Attr
(A
, Name_Last
, N
))));
1762 Append_To
(Stm_List
,
1763 Make_Assignment_Statement
(Loc
,
1764 Name
=> New_Occurrence_Of
(An
, Loc
),
1766 Make_Attribute_Reference
(Loc
,
1767 Prefix
=> New_Occurrence_Of
(Index_T
, Loc
),
1768 Attribute_Name
=> Name_Succ
,
1769 Expressions
=> New_List
(
1770 New_Occurrence_Of
(An
, Loc
)))));
1772 Append_To
(Stm_List
,
1773 Make_Assignment_Statement
(Loc
,
1774 Name
=> New_Occurrence_Of
(Bn
, Loc
),
1776 Make_Attribute_Reference
(Loc
,
1777 Prefix
=> New_Occurrence_Of
(Index_T
, Loc
),
1778 Attribute_Name
=> Name_Succ
,
1779 Expressions
=> New_List
(
1780 New_Occurrence_Of
(Bn
, Loc
)))));
1783 -- If separate indexes, we need a declare block for An and Bn, and a
1784 -- loop without an iteration scheme.
1786 if Need_Separate_Indexes
then
1788 Make_Implicit_Loop_Statement
(Nod
, Statements
=> Stm_List
);
1791 Make_Block_Statement
(Loc
,
1792 Declarations
=> New_List
(
1793 Make_Object_Declaration
(Loc
,
1794 Defining_Identifier
=> An
,
1795 Object_Definition
=> New_Occurrence_Of
(Index_T
, Loc
),
1796 Expression
=> Arr_Attr
(A
, Name_First
, N
)),
1798 Make_Object_Declaration
(Loc
,
1799 Defining_Identifier
=> Bn
,
1800 Object_Definition
=> New_Occurrence_Of
(Index_T
, Loc
),
1801 Expression
=> Arr_Attr
(B
, Name_First
, N
))),
1803 Handled_Statement_Sequence
=>
1804 Make_Handled_Sequence_Of_Statements
(Loc
,
1805 Statements
=> New_List
(Loop_Stm
)));
1807 -- If no separate indexes, return loop statement with explicit
1808 -- iteration scheme on its own
1812 Make_Implicit_Loop_Statement
(Nod
,
1813 Statements
=> Stm_List
,
1815 Make_Iteration_Scheme
(Loc
,
1816 Loop_Parameter_Specification
=>
1817 Make_Loop_Parameter_Specification
(Loc
,
1818 Defining_Identifier
=> An
,
1819 Discrete_Subtype_Definition
=>
1820 Arr_Attr
(A
, Name_Range
, N
))));
1823 end Handle_One_Dimension
;
1825 -----------------------
1826 -- Test_Empty_Arrays --
1827 -----------------------
1829 function Test_Empty_Arrays
return Node_Id
is
1839 for J
in 1 .. Number_Dimensions
(Ltyp
) loop
1842 Left_Opnd
=> Arr_Attr
(A
, Name_Length
, J
),
1843 Right_Opnd
=> Make_Integer_Literal
(Loc
, 0));
1847 Left_Opnd
=> Arr_Attr
(B
, Name_Length
, J
),
1848 Right_Opnd
=> Make_Integer_Literal
(Loc
, 0));
1857 Left_Opnd
=> Relocate_Node
(Alist
),
1858 Right_Opnd
=> Atest
);
1862 Left_Opnd
=> Relocate_Node
(Blist
),
1863 Right_Opnd
=> Btest
);
1870 Right_Opnd
=> Blist
);
1871 end Test_Empty_Arrays
;
1873 -----------------------------
1874 -- Test_Lengths_Correspond --
1875 -----------------------------
1877 function Test_Lengths_Correspond
return Node_Id
is
1883 for J
in 1 .. Number_Dimensions
(Ltyp
) loop
1886 Left_Opnd
=> Arr_Attr
(A
, Name_Length
, J
),
1887 Right_Opnd
=> Arr_Attr
(B
, Name_Length
, J
));
1894 Left_Opnd
=> Relocate_Node
(Result
),
1895 Right_Opnd
=> Rtest
);
1900 end Test_Lengths_Correspond
;
1902 -- Start of processing for Expand_Array_Equality
1905 Ltyp
:= Get_Arg_Type
(Lhs
);
1906 Rtyp
:= Get_Arg_Type
(Rhs
);
1908 -- For now, if the argument types are not the same, go to the base type,
1909 -- since the code assumes that the formals have the same type. This is
1910 -- fixable in future ???
1912 if Ltyp
/= Rtyp
then
1913 Ltyp
:= Base_Type
(Ltyp
);
1914 Rtyp
:= Base_Type
(Rtyp
);
1915 pragma Assert
(Ltyp
= Rtyp
);
1918 -- Build list of formals for function
1920 Formals
:= New_List
(
1921 Make_Parameter_Specification
(Loc
,
1922 Defining_Identifier
=> A
,
1923 Parameter_Type
=> New_Occurrence_Of
(Ltyp
, Loc
)),
1925 Make_Parameter_Specification
(Loc
,
1926 Defining_Identifier
=> B
,
1927 Parameter_Type
=> New_Occurrence_Of
(Rtyp
, Loc
)));
1929 Func_Name
:= Make_Temporary
(Loc
, 'E');
1931 -- Build statement sequence for function
1934 Make_Subprogram_Body
(Loc
,
1936 Make_Function_Specification
(Loc
,
1937 Defining_Unit_Name
=> Func_Name
,
1938 Parameter_Specifications
=> Formals
,
1939 Result_Definition
=> New_Occurrence_Of
(Standard_Boolean
, Loc
)),
1941 Declarations
=> Decls
,
1943 Handled_Statement_Sequence
=>
1944 Make_Handled_Sequence_Of_Statements
(Loc
,
1945 Statements
=> New_List
(
1947 Make_Implicit_If_Statement
(Nod
,
1948 Condition
=> Test_Empty_Arrays
,
1949 Then_Statements
=> New_List
(
1950 Make_Simple_Return_Statement
(Loc
,
1952 New_Occurrence_Of
(Standard_True
, Loc
)))),
1954 Make_Implicit_If_Statement
(Nod
,
1955 Condition
=> Test_Lengths_Correspond
,
1956 Then_Statements
=> New_List
(
1957 Make_Simple_Return_Statement
(Loc
,
1958 Expression
=> New_Occurrence_Of
(Standard_False
, Loc
)))),
1960 Handle_One_Dimension
(1, First_Index
(Ltyp
)),
1962 Make_Simple_Return_Statement
(Loc
,
1963 Expression
=> New_Occurrence_Of
(Standard_True
, Loc
)))));
1965 Set_Has_Completion
(Func_Name
, True);
1966 Set_Is_Inlined
(Func_Name
);
1968 -- If the array type is distinct from the type of the arguments, it
1969 -- is the full view of a private type. Apply an unchecked conversion
1970 -- to insure that analysis of the call succeeds.
1980 or else Base_Type
(Etype
(Lhs
)) /= Base_Type
(Ltyp
)
1982 L
:= OK_Convert_To
(Ltyp
, Lhs
);
1986 or else Base_Type
(Etype
(Rhs
)) /= Base_Type
(Rtyp
)
1988 R
:= OK_Convert_To
(Rtyp
, Rhs
);
1991 Actuals
:= New_List
(L
, R
);
1994 Append_To
(Bodies
, Func_Body
);
1997 Make_Function_Call
(Loc
,
1998 Name
=> New_Occurrence_Of
(Func_Name
, Loc
),
1999 Parameter_Associations
=> Actuals
);
2000 end Expand_Array_Equality
;
2002 -----------------------------
2003 -- Expand_Boolean_Operator --
2004 -----------------------------
2006 -- Note that we first get the actual subtypes of the operands, since we
2007 -- always want to deal with types that have bounds.
2009 procedure Expand_Boolean_Operator
(N
: Node_Id
) is
2010 Typ
: constant Entity_Id
:= Etype
(N
);
2013 -- Special case of bit packed array where both operands are known to be
2014 -- properly aligned. In this case we use an efficient run time routine
2015 -- to carry out the operation (see System.Bit_Ops).
2017 if Is_Bit_Packed_Array
(Typ
)
2018 and then not Is_Possibly_Unaligned_Object
(Left_Opnd
(N
))
2019 and then not Is_Possibly_Unaligned_Object
(Right_Opnd
(N
))
2021 Expand_Packed_Boolean_Operator
(N
);
2025 -- For the normal non-packed case, the general expansion is to build
2026 -- function for carrying out the comparison (use Make_Boolean_Array_Op)
2027 -- and then inserting it into the tree. The original operator node is
2028 -- then rewritten as a call to this function. We also use this in the
2029 -- packed case if either operand is a possibly unaligned object.
2032 Loc
: constant Source_Ptr
:= Sloc
(N
);
2033 L
: constant Node_Id
:= Relocate_Node
(Left_Opnd
(N
));
2034 R
: constant Node_Id
:= Relocate_Node
(Right_Opnd
(N
));
2035 Func_Body
: Node_Id
;
2036 Func_Name
: Entity_Id
;
2039 Convert_To_Actual_Subtype
(L
);
2040 Convert_To_Actual_Subtype
(R
);
2041 Ensure_Defined
(Etype
(L
), N
);
2042 Ensure_Defined
(Etype
(R
), N
);
2043 Apply_Length_Check
(R
, Etype
(L
));
2045 if Nkind
(N
) = N_Op_Xor
then
2046 Silly_Boolean_Array_Xor_Test
(N
, Etype
(L
));
2049 if Nkind
(Parent
(N
)) = N_Assignment_Statement
2050 and then Safe_In_Place_Array_Op
(Name
(Parent
(N
)), L
, R
)
2052 Build_Boolean_Array_Proc_Call
(Parent
(N
), L
, R
);
2054 elsif Nkind
(Parent
(N
)) = N_Op_Not
2055 and then Nkind
(N
) = N_Op_And
2056 and then Nkind
(Parent
(Parent
(N
))) = N_Assignment_Statement
2057 and then Safe_In_Place_Array_Op
(Name
(Parent
(Parent
(N
))), L
, R
)
2062 Func_Body
:= Make_Boolean_Array_Op
(Etype
(L
), N
);
2063 Func_Name
:= Defining_Unit_Name
(Specification
(Func_Body
));
2064 Insert_Action
(N
, Func_Body
);
2066 -- Now rewrite the expression with a call
2069 Make_Function_Call
(Loc
,
2070 Name
=> New_Occurrence_Of
(Func_Name
, Loc
),
2071 Parameter_Associations
=>
2074 Make_Type_Conversion
2075 (Loc
, New_Occurrence_Of
(Etype
(L
), Loc
), R
))));
2077 Analyze_And_Resolve
(N
, Typ
);
2080 end Expand_Boolean_Operator
;
2082 ------------------------------------------------
2083 -- Expand_Compare_Minimize_Eliminate_Overflow --
2084 ------------------------------------------------
2086 procedure Expand_Compare_Minimize_Eliminate_Overflow
(N
: Node_Id
) is
2087 Loc
: constant Source_Ptr
:= Sloc
(N
);
2089 Result_Type
: constant Entity_Id
:= Etype
(N
);
2090 -- Capture result type (could be a derived boolean type)
2095 LLIB
: constant Entity_Id
:= Base_Type
(Standard_Long_Long_Integer
);
2096 -- Entity for Long_Long_Integer'Base
2098 Check
: constant Overflow_Mode_Type
:= Overflow_Check_Mode
;
2099 -- Current overflow checking mode
2102 procedure Set_False
;
2103 -- These procedures rewrite N with an occurrence of Standard_True or
2104 -- Standard_False, and then makes a call to Warn_On_Known_Condition.
2110 procedure Set_False
is
2112 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
2113 Warn_On_Known_Condition
(N
);
2120 procedure Set_True
is
2122 Rewrite
(N
, New_Occurrence_Of
(Standard_True
, Loc
));
2123 Warn_On_Known_Condition
(N
);
2126 -- Start of processing for Expand_Compare_Minimize_Eliminate_Overflow
2129 -- Nothing to do unless we have a comparison operator with operands
2130 -- that are signed integer types, and we are operating in either
2131 -- MINIMIZED or ELIMINATED overflow checking mode.
2133 if Nkind
(N
) not in N_Op_Compare
2134 or else Check
not in Minimized_Or_Eliminated
2135 or else not Is_Signed_Integer_Type
(Etype
(Left_Opnd
(N
)))
2140 -- OK, this is the case we are interested in. First step is to process
2141 -- our operands using the Minimize_Eliminate circuitry which applies
2142 -- this processing to the two operand subtrees.
2144 Minimize_Eliminate_Overflows
2145 (Left_Opnd
(N
), Llo
, Lhi
, Top_Level
=> False);
2146 Minimize_Eliminate_Overflows
2147 (Right_Opnd
(N
), Rlo
, Rhi
, Top_Level
=> False);
2149 -- See if the range information decides the result of the comparison.
2150 -- We can only do this if we in fact have full range information (which
2151 -- won't be the case if either operand is bignum at this stage).
2153 if Llo
/= No_Uint
and then Rlo
/= No_Uint
then
2154 case N_Op_Compare
(Nkind
(N
)) is
2156 if Llo
= Lhi
and then Rlo
= Rhi
and then Llo
= Rlo
then
2158 elsif Llo
> Rhi
or else Lhi
< Rlo
then
2165 elsif Lhi
< Rlo
then
2172 elsif Lhi
<= Rlo
then
2179 elsif Lhi
<= Rlo
then
2186 elsif Lhi
< Rlo
then
2191 if Llo
= Lhi
and then Rlo
= Rhi
and then Llo
= Rlo
then
2193 elsif Llo
> Rhi
or else Lhi
< Rlo
then
2198 -- All done if we did the rewrite
2200 if Nkind
(N
) not in N_Op_Compare
then
2205 -- Otherwise, time to do the comparison
2208 Ltype
: constant Entity_Id
:= Etype
(Left_Opnd
(N
));
2209 Rtype
: constant Entity_Id
:= Etype
(Right_Opnd
(N
));
2212 -- If the two operands have the same signed integer type we are
2213 -- all set, nothing more to do. This is the case where either
2214 -- both operands were unchanged, or we rewrote both of them to
2215 -- be Long_Long_Integer.
2217 -- Note: Entity for the comparison may be wrong, but it's not worth
2218 -- the effort to change it, since the back end does not use it.
2220 if Is_Signed_Integer_Type
(Ltype
)
2221 and then Base_Type
(Ltype
) = Base_Type
(Rtype
)
2225 -- Here if bignums are involved (can only happen in ELIMINATED mode)
2227 elsif Is_RTE
(Ltype
, RE_Bignum
) or else Is_RTE
(Rtype
, RE_Bignum
) then
2229 Left
: Node_Id
:= Left_Opnd
(N
);
2230 Right
: Node_Id
:= Right_Opnd
(N
);
2231 -- Bignum references for left and right operands
2234 if not Is_RTE
(Ltype
, RE_Bignum
) then
2235 Left
:= Convert_To_Bignum
(Left
);
2236 elsif not Is_RTE
(Rtype
, RE_Bignum
) then
2237 Right
:= Convert_To_Bignum
(Right
);
2240 -- We rewrite our node with:
2243 -- Bnn : Result_Type;
2245 -- M : Mark_Id := SS_Mark;
2247 -- Bnn := Big_xx (Left, Right); (xx = EQ, NT etc)
2255 Blk
: constant Node_Id
:= Make_Bignum_Block
(Loc
);
2256 Bnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'B', N
);
2260 case N_Op_Compare
(Nkind
(N
)) is
2261 when N_Op_Eq
=> Ent
:= RE_Big_EQ
;
2262 when N_Op_Ge
=> Ent
:= RE_Big_GE
;
2263 when N_Op_Gt
=> Ent
:= RE_Big_GT
;
2264 when N_Op_Le
=> Ent
:= RE_Big_LE
;
2265 when N_Op_Lt
=> Ent
:= RE_Big_LT
;
2266 when N_Op_Ne
=> Ent
:= RE_Big_NE
;
2269 -- Insert assignment to Bnn into the bignum block
2272 (First
(Statements
(Handled_Statement_Sequence
(Blk
))),
2273 Make_Assignment_Statement
(Loc
,
2274 Name
=> New_Occurrence_Of
(Bnn
, Loc
),
2276 Make_Function_Call
(Loc
,
2278 New_Occurrence_Of
(RTE
(Ent
), Loc
),
2279 Parameter_Associations
=> New_List
(Left
, Right
))));
2281 -- Now do the rewrite with expression actions
2284 Make_Expression_With_Actions
(Loc
,
2285 Actions
=> New_List
(
2286 Make_Object_Declaration
(Loc
,
2287 Defining_Identifier
=> Bnn
,
2288 Object_Definition
=>
2289 New_Occurrence_Of
(Result_Type
, Loc
)),
2291 Expression
=> New_Occurrence_Of
(Bnn
, Loc
)));
2292 Analyze_And_Resolve
(N
, Result_Type
);
2296 -- No bignums involved, but types are different, so we must have
2297 -- rewritten one of the operands as a Long_Long_Integer but not
2300 -- If left operand is Long_Long_Integer, convert right operand
2301 -- and we are done (with a comparison of two Long_Long_Integers).
2303 elsif Ltype
= LLIB
then
2304 Convert_To_And_Rewrite
(LLIB
, Right_Opnd
(N
));
2305 Analyze_And_Resolve
(Right_Opnd
(N
), LLIB
, Suppress
=> All_Checks
);
2308 -- If right operand is Long_Long_Integer, convert left operand
2309 -- and we are done (with a comparison of two Long_Long_Integers).
2311 -- This is the only remaining possibility
2313 else pragma Assert
(Rtype
= LLIB
);
2314 Convert_To_And_Rewrite
(LLIB
, Left_Opnd
(N
));
2315 Analyze_And_Resolve
(Left_Opnd
(N
), LLIB
, Suppress
=> All_Checks
);
2319 end Expand_Compare_Minimize_Eliminate_Overflow
;
2321 -------------------------------
2322 -- Expand_Composite_Equality --
2323 -------------------------------
2325 -- This function is only called for comparing internal fields of composite
2326 -- types when these fields are themselves composites. This is a special
2327 -- case because it is not possible to respect normal Ada visibility rules.
2329 function Expand_Composite_Equality
2334 Bodies
: List_Id
) return Node_Id
2336 Loc
: constant Source_Ptr
:= Sloc
(Nod
);
2337 Full_Type
: Entity_Id
;
2341 function Find_Primitive_Eq
return Node_Id
;
2342 -- AI05-0123: Locate primitive equality for type if it exists, and
2343 -- build the corresponding call. If operation is abstract, replace
2344 -- call with an explicit raise. Return Empty if there is no primitive.
2346 -----------------------
2347 -- Find_Primitive_Eq --
2348 -----------------------
2350 function Find_Primitive_Eq
return Node_Id
is
2355 Prim_E
:= First_Elmt
(Collect_Primitive_Operations
(Typ
));
2356 while Present
(Prim_E
) loop
2357 Prim
:= Node
(Prim_E
);
2359 -- Locate primitive equality with the right signature
2361 if Chars
(Prim
) = Name_Op_Eq
2362 and then Etype
(First_Formal
(Prim
)) =
2363 Etype
(Next_Formal
(First_Formal
(Prim
)))
2364 and then Etype
(Prim
) = Standard_Boolean
2366 if Is_Abstract_Subprogram
(Prim
) then
2368 Make_Raise_Program_Error
(Loc
,
2369 Reason
=> PE_Explicit_Raise
);
2373 Make_Function_Call
(Loc
,
2374 Name
=> New_Occurrence_Of
(Prim
, Loc
),
2375 Parameter_Associations
=> New_List
(Lhs
, Rhs
));
2382 -- If not found, predefined operation will be used
2385 end Find_Primitive_Eq
;
2387 -- Start of processing for Expand_Composite_Equality
2390 if Is_Private_Type
(Typ
) then
2391 Full_Type
:= Underlying_Type
(Typ
);
2396 -- If the private type has no completion the context may be the
2397 -- expansion of a composite equality for a composite type with some
2398 -- still incomplete components. The expression will not be analyzed
2399 -- until the enclosing type is completed, at which point this will be
2400 -- properly expanded, unless there is a bona fide completion error.
2402 if No
(Full_Type
) then
2403 return Make_Op_Eq
(Loc
, Left_Opnd
=> Lhs
, Right_Opnd
=> Rhs
);
2406 Full_Type
:= Base_Type
(Full_Type
);
2408 -- When the base type itself is private, use the full view to expand
2409 -- the composite equality.
2411 if Is_Private_Type
(Full_Type
) then
2412 Full_Type
:= Underlying_Type
(Full_Type
);
2415 -- Case of array types
2417 if Is_Array_Type
(Full_Type
) then
2419 -- If the operand is an elementary type other than a floating-point
2420 -- type, then we can simply use the built-in block bitwise equality,
2421 -- since the predefined equality operators always apply and bitwise
2422 -- equality is fine for all these cases.
2424 if Is_Elementary_Type
(Component_Type
(Full_Type
))
2425 and then not Is_Floating_Point_Type
(Component_Type
(Full_Type
))
2427 return Make_Op_Eq
(Loc
, Left_Opnd
=> Lhs
, Right_Opnd
=> Rhs
);
2429 -- For composite component types, and floating-point types, use the
2430 -- expansion. This deals with tagged component types (where we use
2431 -- the applicable equality routine) and floating-point, (where we
2432 -- need to worry about negative zeroes), and also the case of any
2433 -- composite type recursively containing such fields.
2436 return Expand_Array_Equality
(Nod
, Lhs
, Rhs
, Bodies
, Full_Type
);
2439 -- Case of tagged record types
2441 elsif Is_Tagged_Type
(Full_Type
) then
2443 -- Call the primitive operation "=" of this type
2445 if Is_Class_Wide_Type
(Full_Type
) then
2446 Full_Type
:= Root_Type
(Full_Type
);
2449 -- If this is derived from an untagged private type completed with a
2450 -- tagged type, it does not have a full view, so we use the primitive
2451 -- operations of the private type. This check should no longer be
2452 -- necessary when these types receive their full views ???
2454 if Is_Private_Type
(Typ
)
2455 and then not Is_Tagged_Type
(Typ
)
2456 and then not Is_Controlled
(Typ
)
2457 and then Is_Derived_Type
(Typ
)
2458 and then No
(Full_View
(Typ
))
2460 Prim
:= First_Elmt
(Collect_Primitive_Operations
(Typ
));
2462 Prim
:= First_Elmt
(Primitive_Operations
(Full_Type
));
2466 Eq_Op
:= Node
(Prim
);
2467 exit when Chars
(Eq_Op
) = Name_Op_Eq
2468 and then Etype
(First_Formal
(Eq_Op
)) =
2469 Etype
(Next_Formal
(First_Formal
(Eq_Op
)))
2470 and then Base_Type
(Etype
(Eq_Op
)) = Standard_Boolean
;
2472 pragma Assert
(Present
(Prim
));
2475 Eq_Op
:= Node
(Prim
);
2478 Make_Function_Call
(Loc
,
2479 Name
=> New_Occurrence_Of
(Eq_Op
, Loc
),
2480 Parameter_Associations
=>
2482 (Unchecked_Convert_To
(Etype
(First_Formal
(Eq_Op
)), Lhs
),
2483 Unchecked_Convert_To
(Etype
(First_Formal
(Eq_Op
)), Rhs
)));
2485 -- Case of untagged record types
2487 elsif Is_Record_Type
(Full_Type
) then
2488 Eq_Op
:= TSS
(Full_Type
, TSS_Composite_Equality
);
2490 if Present
(Eq_Op
) then
2491 if Etype
(First_Formal
(Eq_Op
)) /= Full_Type
then
2493 -- Inherited equality from parent type. Convert the actuals to
2494 -- match signature of operation.
2497 T
: constant Entity_Id
:= Etype
(First_Formal
(Eq_Op
));
2501 Make_Function_Call
(Loc
,
2502 Name
=> New_Occurrence_Of
(Eq_Op
, Loc
),
2503 Parameter_Associations
=> New_List
(
2504 OK_Convert_To
(T
, Lhs
),
2505 OK_Convert_To
(T
, Rhs
)));
2509 -- Comparison between Unchecked_Union components
2511 if Is_Unchecked_Union
(Full_Type
) then
2513 Lhs_Type
: Node_Id
:= Full_Type
;
2514 Rhs_Type
: Node_Id
:= Full_Type
;
2515 Lhs_Discr_Val
: Node_Id
;
2516 Rhs_Discr_Val
: Node_Id
;
2521 if Nkind
(Lhs
) = N_Selected_Component
then
2522 Lhs_Type
:= Etype
(Entity
(Selector_Name
(Lhs
)));
2527 if Nkind
(Rhs
) = N_Selected_Component
then
2528 Rhs_Type
:= Etype
(Entity
(Selector_Name
(Rhs
)));
2531 -- Lhs of the composite equality
2533 if Is_Constrained
(Lhs_Type
) then
2535 -- Since the enclosing record type can never be an
2536 -- Unchecked_Union (this code is executed for records
2537 -- that do not have variants), we may reference its
2540 if Nkind
(Lhs
) = N_Selected_Component
2541 and then Has_Per_Object_Constraint
2542 (Entity
(Selector_Name
(Lhs
)))
2545 Make_Selected_Component
(Loc
,
2546 Prefix
=> Prefix
(Lhs
),
2549 (Get_Discriminant_Value
2550 (First_Discriminant
(Lhs_Type
),
2552 Stored_Constraint
(Lhs_Type
))));
2557 (Get_Discriminant_Value
2558 (First_Discriminant
(Lhs_Type
),
2560 Stored_Constraint
(Lhs_Type
)));
2564 -- It is not possible to infer the discriminant since
2565 -- the subtype is not constrained.
2568 Make_Raise_Program_Error
(Loc
,
2569 Reason
=> PE_Unchecked_Union_Restriction
);
2572 -- Rhs of the composite equality
2574 if Is_Constrained
(Rhs_Type
) then
2575 if Nkind
(Rhs
) = N_Selected_Component
2576 and then Has_Per_Object_Constraint
2577 (Entity
(Selector_Name
(Rhs
)))
2580 Make_Selected_Component
(Loc
,
2581 Prefix
=> Prefix
(Rhs
),
2584 (Get_Discriminant_Value
2585 (First_Discriminant
(Rhs_Type
),
2587 Stored_Constraint
(Rhs_Type
))));
2592 (Get_Discriminant_Value
2593 (First_Discriminant
(Rhs_Type
),
2595 Stored_Constraint
(Rhs_Type
)));
2600 Make_Raise_Program_Error
(Loc
,
2601 Reason
=> PE_Unchecked_Union_Restriction
);
2604 -- Call the TSS equality function with the inferred
2605 -- discriminant values.
2608 Make_Function_Call
(Loc
,
2609 Name
=> New_Occurrence_Of
(Eq_Op
, Loc
),
2610 Parameter_Associations
=> New_List
(
2617 -- All cases other than comparing Unchecked_Union types
2621 T
: constant Entity_Id
:= Etype
(First_Formal
(Eq_Op
));
2624 Make_Function_Call
(Loc
,
2626 New_Occurrence_Of
(Eq_Op
, Loc
),
2627 Parameter_Associations
=> New_List
(
2628 OK_Convert_To
(T
, Lhs
),
2629 OK_Convert_To
(T
, Rhs
)));
2634 -- Equality composes in Ada 2012 for untagged record types. It also
2635 -- composes for bounded strings, because they are part of the
2636 -- predefined environment. We could make it compose for bounded
2637 -- strings by making them tagged, or by making sure all subcomponents
2638 -- are set to the same value, even when not used. Instead, we have
2639 -- this special case in the compiler, because it's more efficient.
2641 elsif Ada_Version
>= Ada_2012
or else Is_Bounded_String
(Typ
) then
2643 -- If no TSS has been created for the type, check whether there is
2644 -- a primitive equality declared for it.
2647 Op
: constant Node_Id
:= Find_Primitive_Eq
;
2650 -- Use user-defined primitive if it exists, otherwise use
2651 -- predefined equality.
2653 if Present
(Op
) then
2656 return Make_Op_Eq
(Loc
, Lhs
, Rhs
);
2661 return Expand_Record_Equality
(Nod
, Full_Type
, Lhs
, Rhs
, Bodies
);
2664 -- Non-composite types (always use predefined equality)
2667 return Make_Op_Eq
(Loc
, Left_Opnd
=> Lhs
, Right_Opnd
=> Rhs
);
2669 end Expand_Composite_Equality
;
2671 ------------------------
2672 -- Expand_Concatenate --
2673 ------------------------
2675 procedure Expand_Concatenate
(Cnode
: Node_Id
; Opnds
: List_Id
) is
2676 Loc
: constant Source_Ptr
:= Sloc
(Cnode
);
2678 Atyp
: constant Entity_Id
:= Base_Type
(Etype
(Cnode
));
2679 -- Result type of concatenation
2681 Ctyp
: constant Entity_Id
:= Base_Type
(Component_Type
(Etype
(Cnode
)));
2682 -- Component type. Elements of this component type can appear as one
2683 -- of the operands of concatenation as well as arrays.
2685 Istyp
: constant Entity_Id
:= Etype
(First_Index
(Atyp
));
2688 Ityp
: constant Entity_Id
:= Base_Type
(Istyp
);
2689 -- Index type. This is the base type of the index subtype, and is used
2690 -- for all computed bounds (which may be out of range of Istyp in the
2691 -- case of null ranges).
2694 -- This is the type we use to do arithmetic to compute the bounds and
2695 -- lengths of operands. The choice of this type is a little subtle and
2696 -- is discussed in a separate section at the start of the body code.
2698 Concatenation_Error
: exception;
2699 -- Raised if concatenation is sure to raise a CE
2701 Result_May_Be_Null
: Boolean := True;
2702 -- Reset to False if at least one operand is encountered which is known
2703 -- at compile time to be non-null. Used for handling the special case
2704 -- of setting the high bound to the last operand high bound for a null
2705 -- result, thus ensuring a proper high bound in the super-flat case.
2707 N
: constant Nat
:= List_Length
(Opnds
);
2708 -- Number of concatenation operands including possibly null operands
2711 -- Number of operands excluding any known to be null, except that the
2712 -- last operand is always retained, in case it provides the bounds for
2715 Opnd
: Node_Id
:= Empty
;
2716 -- Current operand being processed in the loop through operands. After
2717 -- this loop is complete, always contains the last operand (which is not
2718 -- the same as Operands (NN), since null operands are skipped).
2720 -- Arrays describing the operands, only the first NN entries of each
2721 -- array are set (NN < N when we exclude known null operands).
2723 Is_Fixed_Length
: array (1 .. N
) of Boolean;
2724 -- True if length of corresponding operand known at compile time
2726 Operands
: array (1 .. N
) of Node_Id
;
2727 -- Set to the corresponding entry in the Opnds list (but note that null
2728 -- operands are excluded, so not all entries in the list are stored).
2730 Fixed_Length
: array (1 .. N
) of Uint
;
2731 -- Set to length of operand. Entries in this array are set only if the
2732 -- corresponding entry in Is_Fixed_Length is True.
2734 Opnd_Low_Bound
: array (1 .. N
) of Node_Id
;
2735 -- Set to lower bound of operand. Either an integer literal in the case
2736 -- where the bound is known at compile time, else actual lower bound.
2737 -- The operand low bound is of type Ityp.
2739 Var_Length
: array (1 .. N
) of Entity_Id
;
2740 -- Set to an entity of type Natural that contains the length of an
2741 -- operand whose length is not known at compile time. Entries in this
2742 -- array are set only if the corresponding entry in Is_Fixed_Length
2743 -- is False. The entity is of type Artyp.
2745 Aggr_Length
: array (0 .. N
) of Node_Id
;
2746 -- The J'th entry in an expression node that represents the total length
2747 -- of operands 1 through J. It is either an integer literal node, or a
2748 -- reference to a constant entity with the right value, so it is fine
2749 -- to just do a Copy_Node to get an appropriate copy. The extra zero'th
2750 -- entry always is set to zero. The length is of type Artyp.
2752 Low_Bound
: Node_Id
;
2753 -- A tree node representing the low bound of the result (of type Ityp).
2754 -- This is either an integer literal node, or an identifier reference to
2755 -- a constant entity initialized to the appropriate value.
2757 Last_Opnd_Low_Bound
: Node_Id
:= Empty
;
2758 -- A tree node representing the low bound of the last operand. This
2759 -- need only be set if the result could be null. It is used for the
2760 -- special case of setting the right low bound for a null result.
2761 -- This is of type Ityp.
2763 Last_Opnd_High_Bound
: Node_Id
:= Empty
;
2764 -- A tree node representing the high bound of the last operand. This
2765 -- need only be set if the result could be null. It is used for the
2766 -- special case of setting the right high bound for a null result.
2767 -- This is of type Ityp.
2769 High_Bound
: Node_Id
:= Empty
;
2770 -- A tree node representing the high bound of the result (of type Ityp)
2773 -- Result of the concatenation (of type Ityp)
2775 Actions
: constant List_Id
:= New_List
;
2776 -- Collect actions to be inserted
2778 Known_Non_Null_Operand_Seen
: Boolean;
2779 -- Set True during generation of the assignments of operands into
2780 -- result once an operand known to be non-null has been seen.
2782 function Library_Level_Target
return Boolean;
2783 -- Return True if the concatenation is within the expression of the
2784 -- declaration of a library-level object.
2786 function Make_Artyp_Literal
(Val
: Nat
) return Node_Id
;
2787 -- This function makes an N_Integer_Literal node that is returned in
2788 -- analyzed form with the type set to Artyp. Importantly this literal
2789 -- is not flagged as static, so that if we do computations with it that
2790 -- result in statically detected out of range conditions, we will not
2791 -- generate error messages but instead warning messages.
2793 function To_Artyp
(X
: Node_Id
) return Node_Id
;
2794 -- Given a node of type Ityp, returns the corresponding value of type
2795 -- Artyp. For non-enumeration types, this is a plain integer conversion.
2796 -- For enum types, the Pos of the value is returned.
2798 function To_Ityp
(X
: Node_Id
) return Node_Id
;
2799 -- The inverse function (uses Val in the case of enumeration types)
2801 --------------------------
2802 -- Library_Level_Target --
2803 --------------------------
2805 function Library_Level_Target
return Boolean is
2806 P
: Node_Id
:= Parent
(Cnode
);
2809 while Present
(P
) loop
2810 if Nkind
(P
) = N_Object_Declaration
then
2811 return Is_Library_Level_Entity
(Defining_Identifier
(P
));
2813 -- Prevent the search from going too far
2815 elsif Is_Body_Or_Package_Declaration
(P
) then
2823 end Library_Level_Target
;
2825 ------------------------
2826 -- Make_Artyp_Literal --
2827 ------------------------
2829 function Make_Artyp_Literal
(Val
: Nat
) return Node_Id
is
2830 Result
: constant Node_Id
:= Make_Integer_Literal
(Loc
, Val
);
2832 Set_Etype
(Result
, Artyp
);
2833 Set_Analyzed
(Result
, True);
2834 Set_Is_Static_Expression
(Result
, False);
2836 end Make_Artyp_Literal
;
2842 function To_Artyp
(X
: Node_Id
) return Node_Id
is
2844 if Ityp
= Base_Type
(Artyp
) then
2847 elsif Is_Enumeration_Type
(Ityp
) then
2849 Make_Attribute_Reference
(Loc
,
2850 Prefix
=> New_Occurrence_Of
(Ityp
, Loc
),
2851 Attribute_Name
=> Name_Pos
,
2852 Expressions
=> New_List
(X
));
2855 return Convert_To
(Artyp
, X
);
2863 function To_Ityp
(X
: Node_Id
) return Node_Id
is
2865 if Is_Enumeration_Type
(Ityp
) then
2867 Make_Attribute_Reference
(Loc
,
2868 Prefix
=> New_Occurrence_Of
(Ityp
, Loc
),
2869 Attribute_Name
=> Name_Val
,
2870 Expressions
=> New_List
(X
));
2872 -- Case where we will do a type conversion
2875 if Ityp
= Base_Type
(Artyp
) then
2878 return Convert_To
(Ityp
, X
);
2883 -- Local Declarations
2885 Opnd_Typ
: Entity_Id
;
2892 -- Start of processing for Expand_Concatenate
2895 -- Choose an appropriate computational type
2897 -- We will be doing calculations of lengths and bounds in this routine
2898 -- and computing one from the other in some cases, e.g. getting the high
2899 -- bound by adding the length-1 to the low bound.
2901 -- We can't just use the index type, or even its base type for this
2902 -- purpose for two reasons. First it might be an enumeration type which
2903 -- is not suitable for computations of any kind, and second it may
2904 -- simply not have enough range. For example if the index type is
2905 -- -128..+127 then lengths can be up to 256, which is out of range of
2908 -- For enumeration types, we can simply use Standard_Integer, this is
2909 -- sufficient since the actual number of enumeration literals cannot
2910 -- possibly exceed the range of integer (remember we will be doing the
2911 -- arithmetic with POS values, not representation values).
2913 if Is_Enumeration_Type
(Ityp
) then
2914 Artyp
:= Standard_Integer
;
2916 -- If index type is Positive, we use the standard unsigned type, to give
2917 -- more room on the top of the range, obviating the need for an overflow
2918 -- check when creating the upper bound. This is needed to avoid junk
2919 -- overflow checks in the common case of String types.
2921 -- ??? Disabled for now
2923 -- elsif Istyp = Standard_Positive then
2924 -- Artyp := Standard_Unsigned;
2926 -- For modular types, we use a 32-bit modular type for types whose size
2927 -- is in the range 1-31 bits. For 32-bit unsigned types, we use the
2928 -- identity type, and for larger unsigned types we use 64-bits.
2930 elsif Is_Modular_Integer_Type
(Ityp
) then
2931 if RM_Size
(Ityp
) < RM_Size
(Standard_Unsigned
) then
2932 Artyp
:= Standard_Unsigned
;
2933 elsif RM_Size
(Ityp
) = RM_Size
(Standard_Unsigned
) then
2936 Artyp
:= RTE
(RE_Long_Long_Unsigned
);
2939 -- Similar treatment for signed types
2942 if RM_Size
(Ityp
) < RM_Size
(Standard_Integer
) then
2943 Artyp
:= Standard_Integer
;
2944 elsif RM_Size
(Ityp
) = RM_Size
(Standard_Integer
) then
2947 Artyp
:= Standard_Long_Long_Integer
;
2951 -- Supply dummy entry at start of length array
2953 Aggr_Length
(0) := Make_Artyp_Literal
(0);
2955 -- Go through operands setting up the above arrays
2959 Opnd
:= Remove_Head
(Opnds
);
2960 Opnd_Typ
:= Etype
(Opnd
);
2962 -- The parent got messed up when we put the operands in a list,
2963 -- so now put back the proper parent for the saved operand, that
2964 -- is to say the concatenation node, to make sure that each operand
2965 -- is seen as a subexpression, e.g. if actions must be inserted.
2967 Set_Parent
(Opnd
, Cnode
);
2969 -- Set will be True when we have setup one entry in the array
2973 -- Singleton element (or character literal) case
2975 if Base_Type
(Opnd_Typ
) = Ctyp
then
2977 Operands
(NN
) := Opnd
;
2978 Is_Fixed_Length
(NN
) := True;
2979 Fixed_Length
(NN
) := Uint_1
;
2980 Result_May_Be_Null
:= False;
2982 -- Set low bound of operand (no need to set Last_Opnd_High_Bound
2983 -- since we know that the result cannot be null).
2985 Opnd_Low_Bound
(NN
) :=
2986 Make_Attribute_Reference
(Loc
,
2987 Prefix
=> New_Occurrence_Of
(Istyp
, Loc
),
2988 Attribute_Name
=> Name_First
);
2992 -- String literal case (can only occur for strings of course)
2994 elsif Nkind
(Opnd
) = N_String_Literal
then
2995 Len
:= String_Literal_Length
(Opnd_Typ
);
2998 Result_May_Be_Null
:= False;
3001 -- Capture last operand low and high bound if result could be null
3003 if J
= N
and then Result_May_Be_Null
then
3004 Last_Opnd_Low_Bound
:=
3005 New_Copy_Tree
(String_Literal_Low_Bound
(Opnd_Typ
));
3007 Last_Opnd_High_Bound
:=
3008 Make_Op_Subtract
(Loc
,
3010 New_Copy_Tree
(String_Literal_Low_Bound
(Opnd_Typ
)),
3011 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1));
3014 -- Skip null string literal
3016 if J
< N
and then Len
= 0 then
3021 Operands
(NN
) := Opnd
;
3022 Is_Fixed_Length
(NN
) := True;
3024 -- Set length and bounds
3026 Fixed_Length
(NN
) := Len
;
3028 Opnd_Low_Bound
(NN
) :=
3029 New_Copy_Tree
(String_Literal_Low_Bound
(Opnd_Typ
));
3036 -- Check constrained case with known bounds
3038 if Is_Constrained
(Opnd_Typ
) then
3040 Index
: constant Node_Id
:= First_Index
(Opnd_Typ
);
3041 Indx_Typ
: constant Entity_Id
:= Etype
(Index
);
3042 Lo
: constant Node_Id
:= Type_Low_Bound
(Indx_Typ
);
3043 Hi
: constant Node_Id
:= Type_High_Bound
(Indx_Typ
);
3046 -- Fixed length constrained array type with known at compile
3047 -- time bounds is last case of fixed length operand.
3049 if Compile_Time_Known_Value
(Lo
)
3051 Compile_Time_Known_Value
(Hi
)
3054 Loval
: constant Uint
:= Expr_Value
(Lo
);
3055 Hival
: constant Uint
:= Expr_Value
(Hi
);
3056 Len
: constant Uint
:=
3057 UI_Max
(Hival
- Loval
+ 1, Uint_0
);
3061 Result_May_Be_Null
:= False;
3064 -- Capture last operand bounds if result could be null
3066 if J
= N
and then Result_May_Be_Null
then
3067 Last_Opnd_Low_Bound
:=
3069 Make_Integer_Literal
(Loc
, Expr_Value
(Lo
)));
3071 Last_Opnd_High_Bound
:=
3073 Make_Integer_Literal
(Loc
, Expr_Value
(Hi
)));
3076 -- Exclude null length case unless last operand
3078 if J
< N
and then Len
= 0 then
3083 Operands
(NN
) := Opnd
;
3084 Is_Fixed_Length
(NN
) := True;
3085 Fixed_Length
(NN
) := Len
;
3087 Opnd_Low_Bound
(NN
) :=
3089 (Make_Integer_Literal
(Loc
, Expr_Value
(Lo
)));
3096 -- All cases where the length is not known at compile time, or the
3097 -- special case of an operand which is known to be null but has a
3098 -- lower bound other than 1 or is other than a string type.
3103 -- Capture operand bounds
3105 Opnd_Low_Bound
(NN
) :=
3106 Make_Attribute_Reference
(Loc
,
3108 Duplicate_Subexpr
(Opnd
, Name_Req
=> True),
3109 Attribute_Name
=> Name_First
);
3111 -- Capture last operand bounds if result could be null
3113 if J
= N
and Result_May_Be_Null
then
3114 Last_Opnd_Low_Bound
:=
3116 Make_Attribute_Reference
(Loc
,
3118 Duplicate_Subexpr
(Opnd
, Name_Req
=> True),
3119 Attribute_Name
=> Name_First
));
3121 Last_Opnd_High_Bound
:=
3123 Make_Attribute_Reference
(Loc
,
3125 Duplicate_Subexpr
(Opnd
, Name_Req
=> True),
3126 Attribute_Name
=> Name_Last
));
3129 -- Capture length of operand in entity
3131 Operands
(NN
) := Opnd
;
3132 Is_Fixed_Length
(NN
) := False;
3134 Var_Length
(NN
) := Make_Temporary
(Loc
, 'L');
3137 Make_Object_Declaration
(Loc
,
3138 Defining_Identifier
=> Var_Length
(NN
),
3139 Constant_Present
=> True,
3140 Object_Definition
=> New_Occurrence_Of
(Artyp
, Loc
),
3142 Make_Attribute_Reference
(Loc
,
3144 Duplicate_Subexpr
(Opnd
, Name_Req
=> True),
3145 Attribute_Name
=> Name_Length
)));
3149 -- Set next entry in aggregate length array
3151 -- For first entry, make either integer literal for fixed length
3152 -- or a reference to the saved length for variable length.
3155 if Is_Fixed_Length
(1) then
3156 Aggr_Length
(1) := Make_Integer_Literal
(Loc
, Fixed_Length
(1));
3158 Aggr_Length
(1) := New_Occurrence_Of
(Var_Length
(1), Loc
);
3161 -- If entry is fixed length and only fixed lengths so far, make
3162 -- appropriate new integer literal adding new length.
3164 elsif Is_Fixed_Length
(NN
)
3165 and then Nkind
(Aggr_Length
(NN
- 1)) = N_Integer_Literal
3168 Make_Integer_Literal
(Loc
,
3169 Intval
=> Fixed_Length
(NN
) + Intval
(Aggr_Length
(NN
- 1)));
3171 -- All other cases, construct an addition node for the length and
3172 -- create an entity initialized to this length.
3175 Ent
:= Make_Temporary
(Loc
, 'L');
3177 if Is_Fixed_Length
(NN
) then
3178 Clen
:= Make_Integer_Literal
(Loc
, Fixed_Length
(NN
));
3180 Clen
:= New_Occurrence_Of
(Var_Length
(NN
), Loc
);
3184 Make_Object_Declaration
(Loc
,
3185 Defining_Identifier
=> Ent
,
3186 Constant_Present
=> True,
3187 Object_Definition
=> New_Occurrence_Of
(Artyp
, Loc
),
3190 Left_Opnd
=> New_Copy_Tree
(Aggr_Length
(NN
- 1)),
3191 Right_Opnd
=> Clen
)));
3193 Aggr_Length
(NN
) := Make_Identifier
(Loc
, Chars
=> Chars
(Ent
));
3200 -- If we have only skipped null operands, return the last operand
3207 -- If we have only one non-null operand, return it and we are done.
3208 -- There is one case in which this cannot be done, and that is when
3209 -- the sole operand is of the element type, in which case it must be
3210 -- converted to an array, and the easiest way of doing that is to go
3211 -- through the normal general circuit.
3213 if NN
= 1 and then Base_Type
(Etype
(Operands
(1))) /= Ctyp
then
3214 Result
:= Operands
(1);
3218 -- Cases where we have a real concatenation
3220 -- Next step is to find the low bound for the result array that we
3221 -- will allocate. The rules for this are in (RM 4.5.6(5-7)).
3223 -- If the ultimate ancestor of the index subtype is a constrained array
3224 -- definition, then the lower bound is that of the index subtype as
3225 -- specified by (RM 4.5.3(6)).
3227 -- The right test here is to go to the root type, and then the ultimate
3228 -- ancestor is the first subtype of this root type.
3230 if Is_Constrained
(First_Subtype
(Root_Type
(Atyp
))) then
3232 Make_Attribute_Reference
(Loc
,
3234 New_Occurrence_Of
(First_Subtype
(Root_Type
(Atyp
)), Loc
),
3235 Attribute_Name
=> Name_First
);
3237 -- If the first operand in the list has known length we know that
3238 -- the lower bound of the result is the lower bound of this operand.
3240 elsif Is_Fixed_Length
(1) then
3241 Low_Bound
:= Opnd_Low_Bound
(1);
3243 -- OK, we don't know the lower bound, we have to build a horrible
3244 -- if expression node of the form
3246 -- if Cond1'Length /= 0 then
3249 -- if Opnd2'Length /= 0 then
3254 -- The nesting ends either when we hit an operand whose length is known
3255 -- at compile time, or on reaching the last operand, whose low bound we
3256 -- take unconditionally whether or not it is null. It's easiest to do
3257 -- this with a recursive procedure:
3261 function Get_Known_Bound
(J
: Nat
) return Node_Id
;
3262 -- Returns the lower bound determined by operands J .. NN
3264 ---------------------
3265 -- Get_Known_Bound --
3266 ---------------------
3268 function Get_Known_Bound
(J
: Nat
) return Node_Id
is
3270 if Is_Fixed_Length
(J
) or else J
= NN
then
3271 return New_Copy_Tree
(Opnd_Low_Bound
(J
));
3275 Make_If_Expression
(Loc
,
3276 Expressions
=> New_List
(
3280 New_Occurrence_Of
(Var_Length
(J
), Loc
),
3282 Make_Integer_Literal
(Loc
, 0)),
3284 New_Copy_Tree
(Opnd_Low_Bound
(J
)),
3285 Get_Known_Bound
(J
+ 1)));
3287 end Get_Known_Bound
;
3290 Ent
:= Make_Temporary
(Loc
, 'L');
3293 Make_Object_Declaration
(Loc
,
3294 Defining_Identifier
=> Ent
,
3295 Constant_Present
=> True,
3296 Object_Definition
=> New_Occurrence_Of
(Ityp
, Loc
),
3297 Expression
=> Get_Known_Bound
(1)));
3299 Low_Bound
:= New_Occurrence_Of
(Ent
, Loc
);
3303 -- Now we can safely compute the upper bound, normally
3304 -- Low_Bound + Length - 1.
3309 Left_Opnd
=> To_Artyp
(New_Copy_Tree
(Low_Bound
)),
3311 Make_Op_Subtract
(Loc
,
3312 Left_Opnd
=> New_Copy_Tree
(Aggr_Length
(NN
)),
3313 Right_Opnd
=> Make_Artyp_Literal
(1))));
3315 -- Note that calculation of the high bound may cause overflow in some
3316 -- very weird cases, so in the general case we need an overflow check on
3317 -- the high bound. We can avoid this for the common case of string types
3318 -- and other types whose index is Positive, since we chose a wider range
3319 -- for the arithmetic type. If checks are suppressed we do not set the
3320 -- flag, and possibly superfluous warnings will be omitted.
3322 if Istyp
/= Standard_Positive
3323 and then not Overflow_Checks_Suppressed
(Istyp
)
3325 Activate_Overflow_Check
(High_Bound
);
3328 -- Handle the exceptional case where the result is null, in which case
3329 -- case the bounds come from the last operand (so that we get the proper
3330 -- bounds if the last operand is super-flat).
3332 if Result_May_Be_Null
then
3334 Make_If_Expression
(Loc
,
3335 Expressions
=> New_List
(
3337 Left_Opnd
=> New_Copy_Tree
(Aggr_Length
(NN
)),
3338 Right_Opnd
=> Make_Artyp_Literal
(0)),
3339 Last_Opnd_Low_Bound
,
3343 Make_If_Expression
(Loc
,
3344 Expressions
=> New_List
(
3346 Left_Opnd
=> New_Copy_Tree
(Aggr_Length
(NN
)),
3347 Right_Opnd
=> Make_Artyp_Literal
(0)),
3348 Last_Opnd_High_Bound
,
3352 -- Here is where we insert the saved up actions
3354 Insert_Actions
(Cnode
, Actions
, Suppress
=> All_Checks
);
3356 -- Now we construct an array object with appropriate bounds. We mark
3357 -- the target as internal to prevent useless initialization when
3358 -- Initialize_Scalars is enabled. Also since this is the actual result
3359 -- entity, we make sure we have debug information for the result.
3361 Ent
:= Make_Temporary
(Loc
, 'S');
3362 Set_Is_Internal
(Ent
);
3363 Set_Needs_Debug_Info
(Ent
);
3365 -- If the bound is statically known to be out of range, we do not want
3366 -- to abort, we want a warning and a runtime constraint error. Note that
3367 -- we have arranged that the result will not be treated as a static
3368 -- constant, so we won't get an illegality during this insertion.
3370 Insert_Action
(Cnode
,
3371 Make_Object_Declaration
(Loc
,
3372 Defining_Identifier
=> Ent
,
3373 Object_Definition
=>
3374 Make_Subtype_Indication
(Loc
,
3375 Subtype_Mark
=> New_Occurrence_Of
(Atyp
, Loc
),
3377 Make_Index_Or_Discriminant_Constraint
(Loc
,
3378 Constraints
=> New_List
(
3380 Low_Bound
=> Low_Bound
,
3381 High_Bound
=> High_Bound
))))),
3382 Suppress
=> All_Checks
);
3384 -- If the result of the concatenation appears as the initializing
3385 -- expression of an object declaration, we can just rename the
3386 -- result, rather than copying it.
3388 Set_OK_To_Rename
(Ent
);
3390 -- Catch the static out of range case now
3392 if Raises_Constraint_Error
(High_Bound
) then
3393 raise Concatenation_Error
;
3396 -- Now we will generate the assignments to do the actual concatenation
3398 -- There is one case in which we will not do this, namely when all the
3399 -- following conditions are met:
3401 -- The result type is Standard.String
3403 -- There are nine or fewer retained (non-null) operands
3405 -- The optimization level is -O0 or the debug flag gnatd.C is set,
3406 -- and the debug flag gnatd.c is not set.
3408 -- The corresponding System.Concat_n.Str_Concat_n routine is
3409 -- available in the run time.
3411 -- If all these conditions are met then we generate a call to the
3412 -- relevant concatenation routine. The purpose of this is to avoid
3413 -- undesirable code bloat at -O0.
3415 -- If the concatenation is within the declaration of a library-level
3416 -- object, we call the built-in concatenation routines to prevent code
3417 -- bloat, regardless of the optimization level. This is space efficient
3418 -- and prevents linking problems when units are compiled with different
3419 -- optimization levels.
3421 if Atyp
= Standard_String
3422 and then NN
in 2 .. 9
3423 and then (((Optimization_Level
= 0 or else Debug_Flag_Dot_CC
)
3424 and then not Debug_Flag_Dot_C
)
3425 or else Library_Level_Target
)
3428 RR
: constant array (Nat
range 2 .. 9) of RE_Id
:=
3439 if RTE_Available
(RR
(NN
)) then
3441 Opnds
: constant List_Id
:=
3442 New_List
(New_Occurrence_Of
(Ent
, Loc
));
3445 for J
in 1 .. NN
loop
3446 if Is_List_Member
(Operands
(J
)) then
3447 Remove
(Operands
(J
));
3450 if Base_Type
(Etype
(Operands
(J
))) = Ctyp
then
3452 Make_Aggregate
(Loc
,
3453 Component_Associations
=> New_List
(
3454 Make_Component_Association
(Loc
,
3455 Choices
=> New_List
(
3456 Make_Integer_Literal
(Loc
, 1)),
3457 Expression
=> Operands
(J
)))));
3460 Append_To
(Opnds
, Operands
(J
));
3464 Insert_Action
(Cnode
,
3465 Make_Procedure_Call_Statement
(Loc
,
3466 Name
=> New_Occurrence_Of
(RTE
(RR
(NN
)), Loc
),
3467 Parameter_Associations
=> Opnds
));
3469 Result
:= New_Occurrence_Of
(Ent
, Loc
);
3476 -- Not special case so generate the assignments
3478 Known_Non_Null_Operand_Seen
:= False;
3480 for J
in 1 .. NN
loop
3482 Lo
: constant Node_Id
:=
3484 Left_Opnd
=> To_Artyp
(New_Copy_Tree
(Low_Bound
)),
3485 Right_Opnd
=> Aggr_Length
(J
- 1));
3487 Hi
: constant Node_Id
:=
3489 Left_Opnd
=> To_Artyp
(New_Copy_Tree
(Low_Bound
)),
3491 Make_Op_Subtract
(Loc
,
3492 Left_Opnd
=> Aggr_Length
(J
),
3493 Right_Opnd
=> Make_Artyp_Literal
(1)));
3496 -- Singleton case, simple assignment
3498 if Base_Type
(Etype
(Operands
(J
))) = Ctyp
then
3499 Known_Non_Null_Operand_Seen
:= True;
3500 Insert_Action
(Cnode
,
3501 Make_Assignment_Statement
(Loc
,
3503 Make_Indexed_Component
(Loc
,
3504 Prefix
=> New_Occurrence_Of
(Ent
, Loc
),
3505 Expressions
=> New_List
(To_Ityp
(Lo
))),
3506 Expression
=> Operands
(J
)),
3507 Suppress
=> All_Checks
);
3509 -- Array case, slice assignment, skipped when argument is fixed
3510 -- length and known to be null.
3512 elsif (not Is_Fixed_Length
(J
)) or else (Fixed_Length
(J
) > 0) then
3515 Make_Assignment_Statement
(Loc
,
3519 New_Occurrence_Of
(Ent
, Loc
),
3522 Low_Bound
=> To_Ityp
(Lo
),
3523 High_Bound
=> To_Ityp
(Hi
))),
3524 Expression
=> Operands
(J
));
3526 if Is_Fixed_Length
(J
) then
3527 Known_Non_Null_Operand_Seen
:= True;
3529 elsif not Known_Non_Null_Operand_Seen
then
3531 -- Here if operand length is not statically known and no
3532 -- operand known to be non-null has been processed yet.
3533 -- If operand length is 0, we do not need to perform the
3534 -- assignment, and we must avoid the evaluation of the
3535 -- high bound of the slice, since it may underflow if the
3536 -- low bound is Ityp'First.
3539 Make_Implicit_If_Statement
(Cnode
,
3543 New_Occurrence_Of
(Var_Length
(J
), Loc
),
3544 Right_Opnd
=> Make_Integer_Literal
(Loc
, 0)),
3545 Then_Statements
=> New_List
(Assign
));
3548 Insert_Action
(Cnode
, Assign
, Suppress
=> All_Checks
);
3554 -- Finally we build the result, which is a reference to the array object
3556 Result
:= New_Occurrence_Of
(Ent
, Loc
);
3559 Rewrite
(Cnode
, Result
);
3560 Analyze_And_Resolve
(Cnode
, Atyp
);
3563 when Concatenation_Error
=>
3565 -- Kill warning generated for the declaration of the static out of
3566 -- range high bound, and instead generate a Constraint_Error with
3567 -- an appropriate specific message.
3569 Kill_Dead_Code
(Declaration_Node
(Entity
(High_Bound
)));
3570 Apply_Compile_Time_Constraint_Error
3572 Msg
=> "concatenation result upper bound out of range??",
3573 Reason
=> CE_Range_Check_Failed
);
3574 end Expand_Concatenate
;
3576 ---------------------------------------------------
3577 -- Expand_Membership_Minimize_Eliminate_Overflow --
3578 ---------------------------------------------------
3580 procedure Expand_Membership_Minimize_Eliminate_Overflow
(N
: Node_Id
) is
3581 pragma Assert
(Nkind
(N
) = N_In
);
3582 -- Despite the name, this routine applies only to N_In, not to
3583 -- N_Not_In. The latter is always rewritten as not (X in Y).
3585 Result_Type
: constant Entity_Id
:= Etype
(N
);
3586 -- Capture result type, may be a derived boolean type
3588 Loc
: constant Source_Ptr
:= Sloc
(N
);
3589 Lop
: constant Node_Id
:= Left_Opnd
(N
);
3590 Rop
: constant Node_Id
:= Right_Opnd
(N
);
3592 -- Note: there are many referencs to Etype (Lop) and Etype (Rop). It
3593 -- is thus tempting to capture these values, but due to the rewrites
3594 -- that occur as a result of overflow checking, these values change
3595 -- as we go along, and it is safe just to always use Etype explicitly.
3597 Restype
: constant Entity_Id
:= Etype
(N
);
3601 -- Bounds in Minimize calls, not used currently
3603 LLIB
: constant Entity_Id
:= Base_Type
(Standard_Long_Long_Integer
);
3604 -- Entity for Long_Long_Integer'Base (Standard should export this???)
3607 Minimize_Eliminate_Overflows
(Lop
, Lo
, Hi
, Top_Level
=> False);
3609 -- If right operand is a subtype name, and the subtype name has no
3610 -- predicate, then we can just replace the right operand with an
3611 -- explicit range T'First .. T'Last, and use the explicit range code.
3613 if Nkind
(Rop
) /= N_Range
3614 and then No
(Predicate_Function
(Etype
(Rop
)))
3617 Rtyp
: constant Entity_Id
:= Etype
(Rop
);
3622 Make_Attribute_Reference
(Loc
,
3623 Attribute_Name
=> Name_First
,
3624 Prefix
=> New_Occurrence_Of
(Rtyp
, Loc
)),
3626 Make_Attribute_Reference
(Loc
,
3627 Attribute_Name
=> Name_Last
,
3628 Prefix
=> New_Occurrence_Of
(Rtyp
, Loc
))));
3629 Analyze_And_Resolve
(Rop
, Rtyp
, Suppress
=> All_Checks
);
3633 -- Here for the explicit range case. Note that the bounds of the range
3634 -- have not been processed for minimized or eliminated checks.
3636 if Nkind
(Rop
) = N_Range
then
3637 Minimize_Eliminate_Overflows
3638 (Low_Bound
(Rop
), Lo
, Hi
, Top_Level
=> False);
3639 Minimize_Eliminate_Overflows
3640 (High_Bound
(Rop
), Lo
, Hi
, Top_Level
=> False);
3642 -- We have A in B .. C, treated as A >= B and then A <= C
3646 if Is_RTE
(Etype
(Lop
), RE_Bignum
)
3647 or else Is_RTE
(Etype
(Low_Bound
(Rop
)), RE_Bignum
)
3648 or else Is_RTE
(Etype
(High_Bound
(Rop
)), RE_Bignum
)
3651 Blk
: constant Node_Id
:= Make_Bignum_Block
(Loc
);
3652 Bnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'B', N
);
3653 L
: constant Entity_Id
:=
3654 Make_Defining_Identifier
(Loc
, Name_uL
);
3655 Lopnd
: constant Node_Id
:= Convert_To_Bignum
(Lop
);
3656 Lbound
: constant Node_Id
:=
3657 Convert_To_Bignum
(Low_Bound
(Rop
));
3658 Hbound
: constant Node_Id
:=
3659 Convert_To_Bignum
(High_Bound
(Rop
));
3661 -- Now we rewrite the membership test node to look like
3664 -- Bnn : Result_Type;
3666 -- M : Mark_Id := SS_Mark;
3667 -- L : Bignum := Lopnd;
3669 -- Bnn := Big_GE (L, Lbound) and then Big_LE (L, Hbound)
3677 -- Insert declaration of L into declarations of bignum block
3680 (Last
(Declarations
(Blk
)),
3681 Make_Object_Declaration
(Loc
,
3682 Defining_Identifier
=> L
,
3683 Object_Definition
=>
3684 New_Occurrence_Of
(RTE
(RE_Bignum
), Loc
),
3685 Expression
=> Lopnd
));
3687 -- Insert assignment to Bnn into expressions of bignum block
3690 (First
(Statements
(Handled_Statement_Sequence
(Blk
))),
3691 Make_Assignment_Statement
(Loc
,
3692 Name
=> New_Occurrence_Of
(Bnn
, Loc
),
3696 Make_Function_Call
(Loc
,
3698 New_Occurrence_Of
(RTE
(RE_Big_GE
), Loc
),
3699 Parameter_Associations
=> New_List
(
3700 New_Occurrence_Of
(L
, Loc
),
3704 Make_Function_Call
(Loc
,
3706 New_Occurrence_Of
(RTE
(RE_Big_LE
), Loc
),
3707 Parameter_Associations
=> New_List
(
3708 New_Occurrence_Of
(L
, Loc
),
3711 -- Now rewrite the node
3714 Make_Expression_With_Actions
(Loc
,
3715 Actions
=> New_List
(
3716 Make_Object_Declaration
(Loc
,
3717 Defining_Identifier
=> Bnn
,
3718 Object_Definition
=>
3719 New_Occurrence_Of
(Result_Type
, Loc
)),
3721 Expression
=> New_Occurrence_Of
(Bnn
, Loc
)));
3722 Analyze_And_Resolve
(N
, Result_Type
);
3726 -- Here if no bignums around
3729 -- Case where types are all the same
3731 if Base_Type
(Etype
(Lop
)) = Base_Type
(Etype
(Low_Bound
(Rop
)))
3733 Base_Type
(Etype
(Lop
)) = Base_Type
(Etype
(High_Bound
(Rop
)))
3737 -- If types are not all the same, it means that we have rewritten
3738 -- at least one of them to be of type Long_Long_Integer, and we
3739 -- will convert the other operands to Long_Long_Integer.
3742 Convert_To_And_Rewrite
(LLIB
, Lop
);
3743 Set_Analyzed
(Lop
, False);
3744 Analyze_And_Resolve
(Lop
, LLIB
);
3746 -- For the right operand, avoid unnecessary recursion into
3747 -- this routine, we know that overflow is not possible.
3749 Convert_To_And_Rewrite
(LLIB
, Low_Bound
(Rop
));
3750 Convert_To_And_Rewrite
(LLIB
, High_Bound
(Rop
));
3751 Set_Analyzed
(Rop
, False);
3752 Analyze_And_Resolve
(Rop
, LLIB
, Suppress
=> Overflow_Check
);
3755 -- Now the three operands are of the same signed integer type,
3756 -- so we can use the normal expansion routine for membership,
3757 -- setting the flag to prevent recursion into this procedure.
3759 Set_No_Minimize_Eliminate
(N
);
3763 -- Right operand is a subtype name and the subtype has a predicate. We
3764 -- have to make sure the predicate is checked, and for that we need to
3765 -- use the standard N_In circuitry with appropriate types.
3768 pragma Assert
(Present
(Predicate_Function
(Etype
(Rop
))));
3770 -- If types are "right", just call Expand_N_In preventing recursion
3772 if Base_Type
(Etype
(Lop
)) = Base_Type
(Etype
(Rop
)) then
3773 Set_No_Minimize_Eliminate
(N
);
3778 elsif Is_RTE
(Etype
(Lop
), RE_Bignum
) then
3780 -- For X in T, we want to rewrite our node as
3783 -- Bnn : Result_Type;
3786 -- M : Mark_Id := SS_Mark;
3787 -- Lnn : Long_Long_Integer'Base
3793 -- if not Bignum_In_LLI_Range (Nnn) then
3796 -- Lnn := From_Bignum (Nnn);
3798 -- Lnn in LLIB (T'Base'First) .. LLIB (T'Base'Last)
3799 -- and then T'Base (Lnn) in T;
3808 -- A bit gruesome, but there doesn't seem to be a simpler way
3811 Blk
: constant Node_Id
:= Make_Bignum_Block
(Loc
);
3812 Bnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'B', N
);
3813 Lnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'L', N
);
3814 Nnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'N', N
);
3815 T
: constant Entity_Id
:= Etype
(Rop
);
3816 TB
: constant Entity_Id
:= Base_Type
(T
);
3820 -- Mark the last membership operation to prevent recursion
3824 Left_Opnd
=> Convert_To
(TB
, New_Occurrence_Of
(Lnn
, Loc
)),
3825 Right_Opnd
=> New_Occurrence_Of
(T
, Loc
));
3826 Set_No_Minimize_Eliminate
(Nin
);
3828 -- Now decorate the block
3831 (Last
(Declarations
(Blk
)),
3832 Make_Object_Declaration
(Loc
,
3833 Defining_Identifier
=> Lnn
,
3834 Object_Definition
=> New_Occurrence_Of
(LLIB
, Loc
)));
3837 (Last
(Declarations
(Blk
)),
3838 Make_Object_Declaration
(Loc
,
3839 Defining_Identifier
=> Nnn
,
3840 Object_Definition
=>
3841 New_Occurrence_Of
(RTE
(RE_Bignum
), Loc
)));
3844 (First
(Statements
(Handled_Statement_Sequence
(Blk
))),
3846 Make_Assignment_Statement
(Loc
,
3847 Name
=> New_Occurrence_Of
(Nnn
, Loc
),
3848 Expression
=> Relocate_Node
(Lop
)),
3850 Make_Implicit_If_Statement
(N
,
3854 Make_Function_Call
(Loc
,
3857 (RTE
(RE_Bignum_In_LLI_Range
), Loc
),
3858 Parameter_Associations
=> New_List
(
3859 New_Occurrence_Of
(Nnn
, Loc
)))),
3861 Then_Statements
=> New_List
(
3862 Make_Assignment_Statement
(Loc
,
3863 Name
=> New_Occurrence_Of
(Bnn
, Loc
),
3865 New_Occurrence_Of
(Standard_False
, Loc
))),
3867 Else_Statements
=> New_List
(
3868 Make_Assignment_Statement
(Loc
,
3869 Name
=> New_Occurrence_Of
(Lnn
, Loc
),
3871 Make_Function_Call
(Loc
,
3873 New_Occurrence_Of
(RTE
(RE_From_Bignum
), Loc
),
3874 Parameter_Associations
=> New_List
(
3875 New_Occurrence_Of
(Nnn
, Loc
)))),
3877 Make_Assignment_Statement
(Loc
,
3878 Name
=> New_Occurrence_Of
(Bnn
, Loc
),
3883 Left_Opnd
=> New_Occurrence_Of
(Lnn
, Loc
),
3888 Make_Attribute_Reference
(Loc
,
3889 Attribute_Name
=> Name_First
,
3891 New_Occurrence_Of
(TB
, Loc
))),
3895 Make_Attribute_Reference
(Loc
,
3896 Attribute_Name
=> Name_Last
,
3898 New_Occurrence_Of
(TB
, Loc
))))),
3900 Right_Opnd
=> Nin
))))));
3902 -- Now we can do the rewrite
3905 Make_Expression_With_Actions
(Loc
,
3906 Actions
=> New_List
(
3907 Make_Object_Declaration
(Loc
,
3908 Defining_Identifier
=> Bnn
,
3909 Object_Definition
=>
3910 New_Occurrence_Of
(Result_Type
, Loc
)),
3912 Expression
=> New_Occurrence_Of
(Bnn
, Loc
)));
3913 Analyze_And_Resolve
(N
, Result_Type
);
3917 -- Not bignum case, but types don't match (this means we rewrote the
3918 -- left operand to be Long_Long_Integer).
3921 pragma Assert
(Base_Type
(Etype
(Lop
)) = LLIB
);
3923 -- We rewrite the membership test as (where T is the type with
3924 -- the predicate, i.e. the type of the right operand)
3926 -- Lop in LLIB (T'Base'First) .. LLIB (T'Base'Last)
3927 -- and then T'Base (Lop) in T
3930 T
: constant Entity_Id
:= Etype
(Rop
);
3931 TB
: constant Entity_Id
:= Base_Type
(T
);
3935 -- The last membership test is marked to prevent recursion
3939 Left_Opnd
=> Convert_To
(TB
, Duplicate_Subexpr
(Lop
)),
3940 Right_Opnd
=> New_Occurrence_Of
(T
, Loc
));
3941 Set_No_Minimize_Eliminate
(Nin
);
3943 -- Now do the rewrite
3954 Make_Attribute_Reference
(Loc
,
3955 Attribute_Name
=> Name_First
,
3957 New_Occurrence_Of
(TB
, Loc
))),
3960 Make_Attribute_Reference
(Loc
,
3961 Attribute_Name
=> Name_Last
,
3963 New_Occurrence_Of
(TB
, Loc
))))),
3964 Right_Opnd
=> Nin
));
3965 Set_Analyzed
(N
, False);
3966 Analyze_And_Resolve
(N
, Restype
);
3970 end Expand_Membership_Minimize_Eliminate_Overflow
;
3972 ---------------------------------
3973 -- Expand_Nonbinary_Modular_Op --
3974 ---------------------------------
3976 procedure Expand_Nonbinary_Modular_Op
(N
: Node_Id
) is
3977 Loc
: constant Source_Ptr
:= Sloc
(N
);
3978 Typ
: constant Entity_Id
:= Etype
(N
);
3980 procedure Expand_Modular_Addition
;
3981 -- Expand the modular addition, handling the special case of adding a
3984 procedure Expand_Modular_Op
;
3985 -- Compute the general rule: (lhs OP rhs) mod Modulus
3987 procedure Expand_Modular_Subtraction
;
3988 -- Expand the modular addition, handling the special case of subtracting
3991 -----------------------------
3992 -- Expand_Modular_Addition --
3993 -----------------------------
3995 procedure Expand_Modular_Addition
is
3997 -- If this is not the addition of a constant then compute it using
3998 -- the general rule: (lhs + rhs) mod Modulus
4000 if Nkind
(Right_Opnd
(N
)) /= N_Integer_Literal
then
4003 -- If this is an addition of a constant, convert it to a subtraction
4004 -- plus a conditional expression since we can compute it faster than
4005 -- computing the modulus.
4007 -- modMinusRhs = Modulus - rhs
4008 -- if lhs < modMinusRhs then lhs + rhs
4009 -- else lhs - modMinusRhs
4013 Mod_Minus_Right
: constant Uint
:=
4014 Modulus
(Typ
) - Intval
(Right_Opnd
(N
));
4016 Exprs
: constant List_Id
:= New_List
;
4017 Cond_Expr
: constant Node_Id
:= New_Op_Node
(N_Op_Lt
, Loc
);
4018 Then_Expr
: constant Node_Id
:= New_Op_Node
(N_Op_Add
, Loc
);
4019 Else_Expr
: constant Node_Id
:= New_Op_Node
(N_Op_Subtract
,
4022 Set_Left_Opnd
(Cond_Expr
,
4023 New_Copy_Tree
(Left_Opnd
(N
)));
4024 Set_Right_Opnd
(Cond_Expr
,
4025 Make_Integer_Literal
(Loc
, Mod_Minus_Right
));
4026 Append_To
(Exprs
, Cond_Expr
);
4028 Set_Left_Opnd
(Then_Expr
,
4029 Unchecked_Convert_To
(Standard_Unsigned
,
4030 New_Copy_Tree
(Left_Opnd
(N
))));
4031 Set_Right_Opnd
(Then_Expr
,
4032 Make_Integer_Literal
(Loc
, Intval
(Right_Opnd
(N
))));
4033 Append_To
(Exprs
, Then_Expr
);
4035 Set_Left_Opnd
(Else_Expr
,
4036 Unchecked_Convert_To
(Standard_Unsigned
,
4037 New_Copy_Tree
(Left_Opnd
(N
))));
4038 Set_Right_Opnd
(Else_Expr
,
4039 Make_Integer_Literal
(Loc
, Mod_Minus_Right
));
4040 Append_To
(Exprs
, Else_Expr
);
4043 Unchecked_Convert_To
(Typ
,
4044 Make_If_Expression
(Loc
, Expressions
=> Exprs
)));
4047 end Expand_Modular_Addition
;
4049 -----------------------
4050 -- Expand_Modular_Op --
4051 -----------------------
4053 procedure Expand_Modular_Op
is
4054 Op_Expr
: constant Node_Id
:= New_Op_Node
(Nkind
(N
), Loc
);
4055 Mod_Expr
: constant Node_Id
:= New_Op_Node
(N_Op_Mod
, Loc
);
4058 -- Convert nonbinary modular type operands into integer values. Thus
4059 -- we avoid never-ending loops expanding them, and we also ensure
4060 -- the back end never receives nonbinary modular type expressions.
4062 if Nkind_In
(Nkind
(N
), N_Op_And
, N_Op_Or
) then
4063 Set_Left_Opnd
(Op_Expr
,
4064 Unchecked_Convert_To
(Standard_Unsigned
,
4065 New_Copy_Tree
(Left_Opnd
(N
))));
4066 Set_Right_Opnd
(Op_Expr
,
4067 Unchecked_Convert_To
(Standard_Unsigned
,
4068 New_Copy_Tree
(Right_Opnd
(N
))));
4069 Set_Left_Opnd
(Mod_Expr
,
4070 Unchecked_Convert_To
(Standard_Integer
, Op_Expr
));
4073 Set_Left_Opnd
(Op_Expr
,
4074 Unchecked_Convert_To
(Standard_Integer
,
4075 New_Copy_Tree
(Left_Opnd
(N
))));
4076 Set_Right_Opnd
(Op_Expr
,
4077 Unchecked_Convert_To
(Standard_Integer
,
4078 New_Copy_Tree
(Right_Opnd
(N
))));
4080 -- Link this node to the tree to analyze it
4082 -- If the parent node is an expression with actions we link it to
4083 -- N since otherwise Force_Evaluation cannot identify if this node
4084 -- comes from the Expression and rejects generating the temporary.
4086 if Nkind
(Parent
(N
)) = N_Expression_With_Actions
then
4087 Set_Parent
(Op_Expr
, N
);
4092 Set_Parent
(Op_Expr
, Parent
(N
));
4097 -- Force generating a temporary because in the expansion of this
4098 -- expression we may generate code that performs this computation
4101 Force_Evaluation
(Op_Expr
, Mode
=> Strict
);
4103 Set_Left_Opnd
(Mod_Expr
, Op_Expr
);
4106 Set_Right_Opnd
(Mod_Expr
,
4107 Make_Integer_Literal
(Loc
, Modulus
(Typ
)));
4110 Unchecked_Convert_To
(Typ
, Mod_Expr
));
4111 end Expand_Modular_Op
;
4113 --------------------------------
4114 -- Expand_Modular_Subtraction --
4115 --------------------------------
4117 procedure Expand_Modular_Subtraction
is
4119 -- If this is not the addition of a constant then compute it using
4120 -- the general rule: (lhs + rhs) mod Modulus
4122 if Nkind
(Right_Opnd
(N
)) /= N_Integer_Literal
then
4125 -- If this is an addition of a constant, convert it to a subtraction
4126 -- plus a conditional expression since we can compute it faster than
4127 -- computing the modulus.
4129 -- modMinusRhs = Modulus - rhs
4130 -- if lhs < rhs then lhs + modMinusRhs
4135 Mod_Minus_Right
: constant Uint
:=
4136 Modulus
(Typ
) - Intval
(Right_Opnd
(N
));
4138 Exprs
: constant List_Id
:= New_List
;
4139 Cond_Expr
: constant Node_Id
:= New_Op_Node
(N_Op_Lt
, Loc
);
4140 Then_Expr
: constant Node_Id
:= New_Op_Node
(N_Op_Add
, Loc
);
4141 Else_Expr
: constant Node_Id
:= New_Op_Node
(N_Op_Subtract
,
4144 Set_Left_Opnd
(Cond_Expr
,
4145 New_Copy_Tree
(Left_Opnd
(N
)));
4146 Set_Right_Opnd
(Cond_Expr
,
4147 Make_Integer_Literal
(Loc
, Intval
(Right_Opnd
(N
))));
4148 Append_To
(Exprs
, Cond_Expr
);
4150 Set_Left_Opnd
(Then_Expr
,
4151 Unchecked_Convert_To
(Standard_Unsigned
,
4152 New_Copy_Tree
(Left_Opnd
(N
))));
4153 Set_Right_Opnd
(Then_Expr
,
4154 Make_Integer_Literal
(Loc
, Mod_Minus_Right
));
4155 Append_To
(Exprs
, Then_Expr
);
4157 Set_Left_Opnd
(Else_Expr
,
4158 Unchecked_Convert_To
(Standard_Unsigned
,
4159 New_Copy_Tree
(Left_Opnd
(N
))));
4160 Set_Right_Opnd
(Else_Expr
,
4161 Unchecked_Convert_To
(Standard_Unsigned
,
4162 New_Copy_Tree
(Right_Opnd
(N
))));
4163 Append_To
(Exprs
, Else_Expr
);
4166 Unchecked_Convert_To
(Typ
,
4167 Make_If_Expression
(Loc
, Expressions
=> Exprs
)));
4170 end Expand_Modular_Subtraction
;
4172 -- Start of processing for Expand_Nonbinary_Modular_Op
4175 -- No action needed if we are not generating C code for a nonbinary
4178 if not Modify_Tree_For_C
4179 or else not Non_Binary_Modulus
(Typ
)
4186 Expand_Modular_Addition
;
4188 when N_Op_Subtract
=>
4189 Expand_Modular_Subtraction
;
4193 -- Expand -expr into (0 - expr)
4196 Make_Op_Subtract
(Loc
,
4197 Left_Opnd
=> Make_Integer_Literal
(Loc
, 0),
4198 Right_Opnd
=> Right_Opnd
(N
)));
4199 Analyze_And_Resolve
(N
, Typ
);
4205 Analyze_And_Resolve
(N
, Typ
);
4206 end Expand_Nonbinary_Modular_Op
;
4208 ------------------------
4209 -- Expand_N_Allocator --
4210 ------------------------
4212 procedure Expand_N_Allocator
(N
: Node_Id
) is
4213 Etyp
: constant Entity_Id
:= Etype
(Expression
(N
));
4214 Loc
: constant Source_Ptr
:= Sloc
(N
);
4215 PtrT
: constant Entity_Id
:= Etype
(N
);
4217 procedure Rewrite_Coextension
(N
: Node_Id
);
4218 -- Static coextensions have the same lifetime as the entity they
4219 -- constrain. Such occurrences can be rewritten as aliased objects
4220 -- and their unrestricted access used instead of the coextension.
4222 function Size_In_Storage_Elements
(E
: Entity_Id
) return Node_Id
;
4223 -- Given a constrained array type E, returns a node representing the
4224 -- code to compute the size in storage elements for the given type.
4225 -- This is done without using the attribute (which malfunctions for
4228 -------------------------
4229 -- Rewrite_Coextension --
4230 -------------------------
4232 procedure Rewrite_Coextension
(N
: Node_Id
) is
4233 Temp_Id
: constant Node_Id
:= Make_Temporary
(Loc
, 'C');
4234 Temp_Decl
: Node_Id
;
4238 -- Cnn : aliased Etyp;
4241 Make_Object_Declaration
(Loc
,
4242 Defining_Identifier
=> Temp_Id
,
4243 Aliased_Present
=> True,
4244 Object_Definition
=> New_Occurrence_Of
(Etyp
, Loc
));
4246 if Nkind
(Expression
(N
)) = N_Qualified_Expression
then
4247 Set_Expression
(Temp_Decl
, Expression
(Expression
(N
)));
4250 Insert_Action
(N
, Temp_Decl
);
4252 Make_Attribute_Reference
(Loc
,
4253 Prefix
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4254 Attribute_Name
=> Name_Unrestricted_Access
));
4256 Analyze_And_Resolve
(N
, PtrT
);
4257 end Rewrite_Coextension
;
4259 ------------------------------
4260 -- Size_In_Storage_Elements --
4261 ------------------------------
4263 function Size_In_Storage_Elements
(E
: Entity_Id
) return Node_Id
is
4265 -- Logically this just returns E'Max_Size_In_Storage_Elements.
4266 -- However, the reason for the existence of this function is
4267 -- to construct a test for sizes too large, which means near the
4268 -- 32-bit limit on a 32-bit machine, and precisely the trouble
4269 -- is that we get overflows when sizes are greater than 2**31.
4271 -- So what we end up doing for array types is to use the expression:
4273 -- number-of-elements * component_type'Max_Size_In_Storage_Elements
4275 -- which avoids this problem. All this is a bit bogus, but it does
4276 -- mean we catch common cases of trying to allocate arrays that
4277 -- are too large, and which in the absence of a check results in
4278 -- undetected chaos ???
4280 -- Note in particular that this is a pessimistic estimate in the
4281 -- case of packed array types, where an array element might occupy
4282 -- just a fraction of a storage element???
4287 pragma Warnings
(Off
, Res
);
4290 for J
in 1 .. Number_Dimensions
(E
) loop
4292 Make_Attribute_Reference
(Loc
,
4293 Prefix
=> New_Occurrence_Of
(E
, Loc
),
4294 Attribute_Name
=> Name_Length
,
4295 Expressions
=> New_List
(Make_Integer_Literal
(Loc
, J
)));
4302 Make_Op_Multiply
(Loc
,
4309 Make_Op_Multiply
(Loc
,
4312 Make_Attribute_Reference
(Loc
,
4313 Prefix
=> New_Occurrence_Of
(Component_Type
(E
), Loc
),
4314 Attribute_Name
=> Name_Max_Size_In_Storage_Elements
));
4316 end Size_In_Storage_Elements
;
4320 Dtyp
: constant Entity_Id
:= Available_View
(Designated_Type
(PtrT
));
4324 Rel_Typ
: Entity_Id
;
4327 -- Start of processing for Expand_N_Allocator
4330 -- RM E.2.3(22). We enforce that the expected type of an allocator
4331 -- shall not be a remote access-to-class-wide-limited-private type
4333 -- Why is this being done at expansion time, seems clearly wrong ???
4335 Validate_Remote_Access_To_Class_Wide_Type
(N
);
4337 -- Processing for anonymous access-to-controlled types. These access
4338 -- types receive a special finalization master which appears in the
4339 -- declarations of the enclosing semantic unit. This expansion is done
4340 -- now to ensure that any additional types generated by this routine or
4341 -- Expand_Allocator_Expression inherit the proper type attributes.
4343 if (Ekind
(PtrT
) = E_Anonymous_Access_Type
4344 or else (Is_Itype
(PtrT
) and then No
(Finalization_Master
(PtrT
))))
4345 and then Needs_Finalization
(Dtyp
)
4347 -- Detect the allocation of an anonymous controlled object where the
4348 -- type of the context is named. For example:
4350 -- procedure Proc (Ptr : Named_Access_Typ);
4351 -- Proc (new Designated_Typ);
4353 -- Regardless of the anonymous-to-named access type conversion, the
4354 -- lifetime of the object must be associated with the named access
4355 -- type. Use the finalization-related attributes of this type.
4357 if Nkind_In
(Parent
(N
), N_Type_Conversion
,
4358 N_Unchecked_Type_Conversion
)
4359 and then Ekind_In
(Etype
(Parent
(N
)), E_Access_Subtype
,
4361 E_General_Access_Type
)
4363 Rel_Typ
:= Etype
(Parent
(N
));
4368 -- Anonymous access-to-controlled types allocate on the global pool.
4369 -- Note that this is a "root type only" attribute.
4371 if No
(Associated_Storage_Pool
(PtrT
)) then
4372 if Present
(Rel_Typ
) then
4373 Set_Associated_Storage_Pool
4374 (Root_Type
(PtrT
), Associated_Storage_Pool
(Rel_Typ
));
4376 Set_Associated_Storage_Pool
4377 (Root_Type
(PtrT
), RTE
(RE_Global_Pool_Object
));
4381 -- The finalization master must be inserted and analyzed as part of
4382 -- the current semantic unit. Note that the master is updated when
4383 -- analysis changes current units. Note that this is a "root type
4386 if Present
(Rel_Typ
) then
4387 Set_Finalization_Master
4388 (Root_Type
(PtrT
), Finalization_Master
(Rel_Typ
));
4390 Build_Anonymous_Master
(Root_Type
(PtrT
));
4394 -- Set the storage pool and find the appropriate version of Allocate to
4395 -- call. Do not overwrite the storage pool if it is already set, which
4396 -- can happen for build-in-place function returns (see
4397 -- Exp_Ch4.Expand_N_Extended_Return_Statement).
4399 if No
(Storage_Pool
(N
)) then
4400 Pool
:= Associated_Storage_Pool
(Root_Type
(PtrT
));
4402 if Present
(Pool
) then
4403 Set_Storage_Pool
(N
, Pool
);
4405 if Is_RTE
(Pool
, RE_SS_Pool
) then
4406 Set_Procedure_To_Call
(N
, RTE
(RE_SS_Allocate
));
4408 -- In the case of an allocator for a simple storage pool, locate
4409 -- and save a reference to the pool type's Allocate routine.
4411 elsif Present
(Get_Rep_Pragma
4412 (Etype
(Pool
), Name_Simple_Storage_Pool_Type
))
4415 Pool_Type
: constant Entity_Id
:= Base_Type
(Etype
(Pool
));
4416 Alloc_Op
: Entity_Id
;
4418 Alloc_Op
:= Get_Name_Entity_Id
(Name_Allocate
);
4419 while Present
(Alloc_Op
) loop
4420 if Scope
(Alloc_Op
) = Scope
(Pool_Type
)
4421 and then Present
(First_Formal
(Alloc_Op
))
4422 and then Etype
(First_Formal
(Alloc_Op
)) = Pool_Type
4424 Set_Procedure_To_Call
(N
, Alloc_Op
);
4427 Alloc_Op
:= Homonym
(Alloc_Op
);
4432 elsif Is_Class_Wide_Type
(Etype
(Pool
)) then
4433 Set_Procedure_To_Call
(N
, RTE
(RE_Allocate_Any
));
4436 Set_Procedure_To_Call
(N
,
4437 Find_Prim_Op
(Etype
(Pool
), Name_Allocate
));
4442 -- Under certain circumstances we can replace an allocator by an access
4443 -- to statically allocated storage. The conditions, as noted in AARM
4444 -- 3.10 (10c) are as follows:
4446 -- Size and initial value is known at compile time
4447 -- Access type is access-to-constant
4449 -- The allocator is not part of a constraint on a record component,
4450 -- because in that case the inserted actions are delayed until the
4451 -- record declaration is fully analyzed, which is too late for the
4452 -- analysis of the rewritten allocator.
4454 if Is_Access_Constant
(PtrT
)
4455 and then Nkind
(Expression
(N
)) = N_Qualified_Expression
4456 and then Compile_Time_Known_Value
(Expression
(Expression
(N
)))
4457 and then Size_Known_At_Compile_Time
4458 (Etype
(Expression
(Expression
(N
))))
4459 and then not Is_Record_Type
(Current_Scope
)
4461 -- Here we can do the optimization. For the allocator
4465 -- We insert an object declaration
4467 -- Tnn : aliased x := y;
4469 -- and replace the allocator by Tnn'Unrestricted_Access. Tnn is
4470 -- marked as requiring static allocation.
4472 Temp
:= Make_Temporary
(Loc
, 'T', Expression
(Expression
(N
)));
4473 Desig
:= Subtype_Mark
(Expression
(N
));
4475 -- If context is constrained, use constrained subtype directly,
4476 -- so that the constant is not labelled as having a nominally
4477 -- unconstrained subtype.
4479 if Entity
(Desig
) = Base_Type
(Dtyp
) then
4480 Desig
:= New_Occurrence_Of
(Dtyp
, Loc
);
4484 Make_Object_Declaration
(Loc
,
4485 Defining_Identifier
=> Temp
,
4486 Aliased_Present
=> True,
4487 Constant_Present
=> Is_Access_Constant
(PtrT
),
4488 Object_Definition
=> Desig
,
4489 Expression
=> Expression
(Expression
(N
))));
4492 Make_Attribute_Reference
(Loc
,
4493 Prefix
=> New_Occurrence_Of
(Temp
, Loc
),
4494 Attribute_Name
=> Name_Unrestricted_Access
));
4496 Analyze_And_Resolve
(N
, PtrT
);
4498 -- We set the variable as statically allocated, since we don't want
4499 -- it going on the stack of the current procedure.
4501 Set_Is_Statically_Allocated
(Temp
);
4505 -- Same if the allocator is an access discriminant for a local object:
4506 -- instead of an allocator we create a local value and constrain the
4507 -- enclosing object with the corresponding access attribute.
4509 if Is_Static_Coextension
(N
) then
4510 Rewrite_Coextension
(N
);
4514 -- Check for size too large, we do this because the back end misses
4515 -- proper checks here and can generate rubbish allocation calls when
4516 -- we are near the limit. We only do this for the 32-bit address case
4517 -- since that is from a practical point of view where we see a problem.
4519 if System_Address_Size
= 32
4520 and then not Storage_Checks_Suppressed
(PtrT
)
4521 and then not Storage_Checks_Suppressed
(Dtyp
)
4522 and then not Storage_Checks_Suppressed
(Etyp
)
4524 -- The check we want to generate should look like
4526 -- if Etyp'Max_Size_In_Storage_Elements > 3.5 gigabytes then
4527 -- raise Storage_Error;
4530 -- where 3.5 gigabytes is a constant large enough to accommodate any
4531 -- reasonable request for. But we can't do it this way because at
4532 -- least at the moment we don't compute this attribute right, and
4533 -- can silently give wrong results when the result gets large. Since
4534 -- this is all about large results, that's bad, so instead we only
4535 -- apply the check for constrained arrays, and manually compute the
4536 -- value of the attribute ???
4538 if Is_Array_Type
(Etyp
) and then Is_Constrained
(Etyp
) then
4540 Make_Raise_Storage_Error
(Loc
,
4543 Left_Opnd
=> Size_In_Storage_Elements
(Etyp
),
4545 Make_Integer_Literal
(Loc
, Uint_7
* (Uint_2
** 29))),
4546 Reason
=> SE_Object_Too_Large
));
4550 -- If no storage pool has been specified and we have the restriction
4551 -- No_Standard_Allocators_After_Elaboration is present, then generate
4552 -- a call to Elaboration_Allocators.Check_Standard_Allocator.
4554 if Nkind
(N
) = N_Allocator
4555 and then No
(Storage_Pool
(N
))
4556 and then Restriction_Active
(No_Standard_Allocators_After_Elaboration
)
4559 Make_Procedure_Call_Statement
(Loc
,
4561 New_Occurrence_Of
(RTE
(RE_Check_Standard_Allocator
), Loc
)));
4564 -- Handle case of qualified expression (other than optimization above)
4565 -- First apply constraint checks, because the bounds or discriminants
4566 -- in the aggregate might not match the subtype mark in the allocator.
4568 if Nkind
(Expression
(N
)) = N_Qualified_Expression
then
4570 Exp
: constant Node_Id
:= Expression
(Expression
(N
));
4571 Typ
: constant Entity_Id
:= Etype
(Expression
(N
));
4574 Apply_Constraint_Check
(Exp
, Typ
);
4575 Apply_Predicate_Check
(Exp
, Typ
);
4578 Expand_Allocator_Expression
(N
);
4582 -- If the allocator is for a type which requires initialization, and
4583 -- there is no initial value (i.e. operand is a subtype indication
4584 -- rather than a qualified expression), then we must generate a call to
4585 -- the initialization routine using an expressions action node:
4587 -- [Pnnn : constant ptr_T := new (T); Init (Pnnn.all,...); Pnnn]
4589 -- Here ptr_T is the pointer type for the allocator, and T is the
4590 -- subtype of the allocator. A special case arises if the designated
4591 -- type of the access type is a task or contains tasks. In this case
4592 -- the call to Init (Temp.all ...) is replaced by code that ensures
4593 -- that tasks get activated (see Exp_Ch9.Build_Task_Allocate_Block
4594 -- for details). In addition, if the type T is a task type, then the
4595 -- first argument to Init must be converted to the task record type.
4598 T
: constant Entity_Id
:= Entity
(Expression
(N
));
4604 Init_Arg1
: Node_Id
;
4605 Init_Call
: Node_Id
;
4606 Temp_Decl
: Node_Id
;
4607 Temp_Type
: Entity_Id
;
4610 if No_Initialization
(N
) then
4612 -- Even though this might be a simple allocation, create a custom
4613 -- Allocate if the context requires it.
4615 if Present
(Finalization_Master
(PtrT
)) then
4616 Build_Allocate_Deallocate_Proc
4618 Is_Allocate
=> True);
4621 -- Case of no initialization procedure present
4623 elsif not Has_Non_Null_Base_Init_Proc
(T
) then
4625 -- Case of simple initialization required
4627 if Needs_Simple_Initialization
(T
) then
4628 Check_Restriction
(No_Default_Initialization
, N
);
4629 Rewrite
(Expression
(N
),
4630 Make_Qualified_Expression
(Loc
,
4631 Subtype_Mark
=> New_Occurrence_Of
(T
, Loc
),
4632 Expression
=> Get_Simple_Init_Val
(T
, N
)));
4634 Analyze_And_Resolve
(Expression
(Expression
(N
)), T
);
4635 Analyze_And_Resolve
(Expression
(N
), T
);
4636 Set_Paren_Count
(Expression
(Expression
(N
)), 1);
4637 Expand_N_Allocator
(N
);
4639 -- No initialization required
4642 Build_Allocate_Deallocate_Proc
4644 Is_Allocate
=> True);
4647 -- Case of initialization procedure present, must be called
4650 Check_Restriction
(No_Default_Initialization
, N
);
4652 if not Restriction_Active
(No_Default_Initialization
) then
4653 Init
:= Base_Init_Proc
(T
);
4655 Temp
:= Make_Temporary
(Loc
, 'P');
4657 -- Construct argument list for the initialization routine call
4660 Make_Explicit_Dereference
(Loc
,
4662 New_Occurrence_Of
(Temp
, Loc
));
4664 Set_Assignment_OK
(Init_Arg1
);
4667 -- The initialization procedure expects a specific type. if the
4668 -- context is access to class wide, indicate that the object
4669 -- being allocated has the right specific type.
4671 if Is_Class_Wide_Type
(Dtyp
) then
4672 Init_Arg1
:= Unchecked_Convert_To
(T
, Init_Arg1
);
4675 -- If designated type is a concurrent type or if it is private
4676 -- type whose definition is a concurrent type, the first
4677 -- argument in the Init routine has to be unchecked conversion
4678 -- to the corresponding record type. If the designated type is
4679 -- a derived type, also convert the argument to its root type.
4681 if Is_Concurrent_Type
(T
) then
4683 Unchecked_Convert_To
(
4684 Corresponding_Record_Type
(T
), Init_Arg1
);
4686 elsif Is_Private_Type
(T
)
4687 and then Present
(Full_View
(T
))
4688 and then Is_Concurrent_Type
(Full_View
(T
))
4691 Unchecked_Convert_To
4692 (Corresponding_Record_Type
(Full_View
(T
)), Init_Arg1
);
4694 elsif Etype
(First_Formal
(Init
)) /= Base_Type
(T
) then
4696 Ftyp
: constant Entity_Id
:= Etype
(First_Formal
(Init
));
4699 Init_Arg1
:= OK_Convert_To
(Etype
(Ftyp
), Init_Arg1
);
4700 Set_Etype
(Init_Arg1
, Ftyp
);
4704 Args
:= New_List
(Init_Arg1
);
4706 -- For the task case, pass the Master_Id of the access type as
4707 -- the value of the _Master parameter, and _Chain as the value
4708 -- of the _Chain parameter (_Chain will be defined as part of
4709 -- the generated code for the allocator).
4711 -- In Ada 2005, the context may be a function that returns an
4712 -- anonymous access type. In that case the Master_Id has been
4713 -- created when expanding the function declaration.
4715 if Has_Task
(T
) then
4716 if No
(Master_Id
(Base_Type
(PtrT
))) then
4718 -- The designated type was an incomplete type, and the
4719 -- access type did not get expanded. Salvage it now.
4721 if not Restriction_Active
(No_Task_Hierarchy
) then
4722 if Present
(Parent
(Base_Type
(PtrT
))) then
4723 Expand_N_Full_Type_Declaration
4724 (Parent
(Base_Type
(PtrT
)));
4726 -- The only other possibility is an itype. For this
4727 -- case, the master must exist in the context. This is
4728 -- the case when the allocator initializes an access
4729 -- component in an init-proc.
4732 pragma Assert
(Is_Itype
(PtrT
));
4733 Build_Master_Renaming
(PtrT
, N
);
4738 -- If the context of the allocator is a declaration or an
4739 -- assignment, we can generate a meaningful image for it,
4740 -- even though subsequent assignments might remove the
4741 -- connection between task and entity. We build this image
4742 -- when the left-hand side is a simple variable, a simple
4743 -- indexed assignment or a simple selected component.
4745 if Nkind
(Parent
(N
)) = N_Assignment_Statement
then
4747 Nam
: constant Node_Id
:= Name
(Parent
(N
));
4750 if Is_Entity_Name
(Nam
) then
4752 Build_Task_Image_Decls
4755 (Entity
(Nam
), Sloc
(Nam
)), T
);
4757 elsif Nkind_In
(Nam
, N_Indexed_Component
,
4758 N_Selected_Component
)
4759 and then Is_Entity_Name
(Prefix
(Nam
))
4762 Build_Task_Image_Decls
4763 (Loc
, Nam
, Etype
(Prefix
(Nam
)));
4765 Decls
:= Build_Task_Image_Decls
(Loc
, T
, T
);
4769 elsif Nkind
(Parent
(N
)) = N_Object_Declaration
then
4771 Build_Task_Image_Decls
4772 (Loc
, Defining_Identifier
(Parent
(N
)), T
);
4775 Decls
:= Build_Task_Image_Decls
(Loc
, T
, T
);
4778 if Restriction_Active
(No_Task_Hierarchy
) then
4780 New_Occurrence_Of
(RTE
(RE_Library_Task_Level
), Loc
));
4784 (Master_Id
(Base_Type
(Root_Type
(PtrT
))), Loc
));
4787 Append_To
(Args
, Make_Identifier
(Loc
, Name_uChain
));
4789 Decl
:= Last
(Decls
);
4791 New_Occurrence_Of
(Defining_Identifier
(Decl
), Loc
));
4793 -- Has_Task is false, Decls not used
4799 -- Add discriminants if discriminated type
4802 Dis
: Boolean := False;
4803 Typ
: Entity_Id
:= Empty
;
4806 if Has_Discriminants
(T
) then
4810 -- Type may be a private type with no visible discriminants
4811 -- in which case check full view if in scope, or the
4812 -- underlying_full_view if dealing with a type whose full
4813 -- view may be derived from a private type whose own full
4814 -- view has discriminants.
4816 elsif Is_Private_Type
(T
) then
4817 if Present
(Full_View
(T
))
4818 and then Has_Discriminants
(Full_View
(T
))
4821 Typ
:= Full_View
(T
);
4823 elsif Present
(Underlying_Full_View
(T
))
4824 and then Has_Discriminants
(Underlying_Full_View
(T
))
4827 Typ
:= Underlying_Full_View
(T
);
4833 -- If the allocated object will be constrained by the
4834 -- default values for discriminants, then build a subtype
4835 -- with those defaults, and change the allocated subtype
4836 -- to that. Note that this happens in fewer cases in Ada
4839 if not Is_Constrained
(Typ
)
4840 and then Present
(Discriminant_Default_Value
4841 (First_Discriminant
(Typ
)))
4842 and then (Ada_Version
< Ada_2005
4844 Object_Type_Has_Constrained_Partial_View
4845 (Typ
, Current_Scope
))
4847 Typ
:= Build_Default_Subtype
(Typ
, N
);
4848 Set_Expression
(N
, New_Occurrence_Of
(Typ
, Loc
));
4851 Discr
:= First_Elmt
(Discriminant_Constraint
(Typ
));
4852 while Present
(Discr
) loop
4853 Nod
:= Node
(Discr
);
4854 Append
(New_Copy_Tree
(Node
(Discr
)), Args
);
4856 -- AI-416: when the discriminant constraint is an
4857 -- anonymous access type make sure an accessibility
4858 -- check is inserted if necessary (3.10.2(22.q/2))
4860 if Ada_Version
>= Ada_2005
4862 Ekind
(Etype
(Nod
)) = E_Anonymous_Access_Type
4864 Apply_Accessibility_Check
4865 (Nod
, Typ
, Insert_Node
=> Nod
);
4873 -- We set the allocator as analyzed so that when we analyze
4874 -- the if expression node, we do not get an unwanted recursive
4875 -- expansion of the allocator expression.
4877 Set_Analyzed
(N
, True);
4878 Nod
:= Relocate_Node
(N
);
4880 -- Here is the transformation:
4881 -- input: new Ctrl_Typ
4882 -- output: Temp : constant Ctrl_Typ_Ptr := new Ctrl_Typ;
4883 -- Ctrl_TypIP (Temp.all, ...);
4884 -- [Deep_]Initialize (Temp.all);
4886 -- Here Ctrl_Typ_Ptr is the pointer type for the allocator, and
4887 -- is the subtype of the allocator.
4890 Make_Object_Declaration
(Loc
,
4891 Defining_Identifier
=> Temp
,
4892 Constant_Present
=> True,
4893 Object_Definition
=> New_Occurrence_Of
(Temp_Type
, Loc
),
4896 Set_Assignment_OK
(Temp_Decl
);
4897 Insert_Action
(N
, Temp_Decl
, Suppress
=> All_Checks
);
4899 Build_Allocate_Deallocate_Proc
(Temp_Decl
, True);
4901 -- If the designated type is a task type or contains tasks,
4902 -- create block to activate created tasks, and insert
4903 -- declaration for Task_Image variable ahead of call.
4905 if Has_Task
(T
) then
4907 L
: constant List_Id
:= New_List
;
4910 Build_Task_Allocate_Block
(L
, Nod
, Args
);
4912 Insert_List_Before
(First
(Declarations
(Blk
)), Decls
);
4913 Insert_Actions
(N
, L
);
4918 Make_Procedure_Call_Statement
(Loc
,
4919 Name
=> New_Occurrence_Of
(Init
, Loc
),
4920 Parameter_Associations
=> Args
));
4923 if Needs_Finalization
(T
) then
4926 -- [Deep_]Initialize (Init_Arg1);
4930 (Obj_Ref
=> New_Copy_Tree
(Init_Arg1
),
4933 -- Guard against a missing [Deep_]Initialize when the
4934 -- designated type was not properly frozen.
4936 if Present
(Init_Call
) then
4937 Insert_Action
(N
, Init_Call
);
4941 Rewrite
(N
, New_Occurrence_Of
(Temp
, Loc
));
4942 Analyze_And_Resolve
(N
, PtrT
);
4947 -- Ada 2005 (AI-251): If the allocator is for a class-wide interface
4948 -- object that has been rewritten as a reference, we displace "this"
4949 -- to reference properly its secondary dispatch table.
4951 if Nkind
(N
) = N_Identifier
and then Is_Interface
(Dtyp
) then
4952 Displace_Allocator_Pointer
(N
);
4956 when RE_Not_Available
=>
4958 end Expand_N_Allocator
;
4960 -----------------------
4961 -- Expand_N_And_Then --
4962 -----------------------
4964 procedure Expand_N_And_Then
(N
: Node_Id
)
4965 renames Expand_Short_Circuit_Operator
;
4967 ------------------------------
4968 -- Expand_N_Case_Expression --
4969 ------------------------------
4971 procedure Expand_N_Case_Expression
(N
: Node_Id
) is
4973 function Is_Copy_Type
(Typ
: Entity_Id
) return Boolean;
4974 -- Return True if we can copy objects of this type when expanding a case
4981 function Is_Copy_Type
(Typ
: Entity_Id
) return Boolean is
4983 -- If Minimize_Expression_With_Actions is True, we can afford to copy
4984 -- large objects, as long as they are constrained and not limited.
4987 Is_Elementary_Type
(Underlying_Type
(Typ
))
4989 (Minimize_Expression_With_Actions
4990 and then Is_Constrained
(Underlying_Type
(Typ
))
4991 and then not Is_Limited_View
(Underlying_Type
(Typ
)));
4996 Loc
: constant Source_Ptr
:= Sloc
(N
);
4997 Par
: constant Node_Id
:= Parent
(N
);
4998 Typ
: constant Entity_Id
:= Etype
(N
);
5002 Case_Stmt
: Node_Id
;
5006 Target_Typ
: Entity_Id
;
5008 In_Predicate
: Boolean := False;
5009 -- Flag set when the case expression appears within a predicate
5011 Optimize_Return_Stmt
: Boolean := False;
5012 -- Flag set when the case expression can be optimized in the context of
5013 -- a simple return statement.
5015 -- Start of processing for Expand_N_Case_Expression
5018 -- Check for MINIMIZED/ELIMINATED overflow mode
5020 if Minimized_Eliminated_Overflow_Check
(N
) then
5021 Apply_Arithmetic_Overflow_Check
(N
);
5025 -- If the case expression is a predicate specification, and the type
5026 -- to which it applies has a static predicate aspect, do not expand,
5027 -- because it will be converted to the proper predicate form later.
5029 if Ekind_In
(Current_Scope
, E_Function
, E_Procedure
)
5030 and then Is_Predicate_Function
(Current_Scope
)
5032 In_Predicate
:= True;
5034 if Has_Static_Predicate_Aspect
(Etype
(First_Entity
(Current_Scope
)))
5040 -- When the type of the case expression is elementary, expand
5042 -- (case X is when A => AX, when B => BX ...)
5057 -- In all other cases expand into
5060 -- type Ptr_Typ is access all Typ;
5061 -- Target : Ptr_Typ;
5064 -- Target := AX'Unrestricted_Access;
5066 -- Target := BX'Unrestricted_Access;
5069 -- in Target.all end;
5071 -- This approach avoids extra copies of potentially large objects. It
5072 -- also allows handling of values of limited or unconstrained types.
5073 -- Note that we do the copy also for constrained, nonlimited types
5074 -- when minimizing expressions with actions (e.g. when generating C
5075 -- code) since it allows us to do the optimization below in more cases.
5077 -- Small optimization: when the case expression appears in the context
5078 -- of a simple return statement, expand into
5089 Make_Case_Statement
(Loc
,
5090 Expression
=> Expression
(N
),
5091 Alternatives
=> New_List
);
5093 -- Preserve the original context for which the case statement is being
5094 -- generated. This is needed by the finalization machinery to prevent
5095 -- the premature finalization of controlled objects found within the
5098 Set_From_Conditional_Expression
(Case_Stmt
);
5103 if Is_Copy_Type
(Typ
) then
5106 -- ??? Do not perform the optimization when the return statement is
5107 -- within a predicate function, as this causes spurious errors. Could
5108 -- this be a possible mismatch in handling this case somewhere else
5109 -- in semantic analysis?
5111 Optimize_Return_Stmt
:=
5112 Nkind
(Par
) = N_Simple_Return_Statement
and then not In_Predicate
;
5114 -- Otherwise create an access type to handle the general case using
5115 -- 'Unrestricted_Access.
5118 -- type Ptr_Typ is access all Typ;
5121 if Generate_C_Code
then
5123 -- We cannot ensure that correct C code will be generated if any
5124 -- temporary is created down the line (to e.g. handle checks or
5125 -- capture values) since we might end up with dangling references
5126 -- to local variables, so better be safe and reject the construct.
5129 ("case expression too complex, use case statement instead", N
);
5132 Target_Typ
:= Make_Temporary
(Loc
, 'P');
5135 Make_Full_Type_Declaration
(Loc
,
5136 Defining_Identifier
=> Target_Typ
,
5138 Make_Access_To_Object_Definition
(Loc
,
5139 All_Present
=> True,
5140 Subtype_Indication
=> New_Occurrence_Of
(Typ
, Loc
))));
5143 -- Create the declaration of the target which captures the value of the
5147 -- Target : [Ptr_]Typ;
5149 if not Optimize_Return_Stmt
then
5150 Target
:= Make_Temporary
(Loc
, 'T');
5153 Make_Object_Declaration
(Loc
,
5154 Defining_Identifier
=> Target
,
5155 Object_Definition
=> New_Occurrence_Of
(Target_Typ
, Loc
));
5156 Set_No_Initialization
(Decl
);
5158 Append_To
(Acts
, Decl
);
5161 -- Process the alternatives
5163 Alt
:= First
(Alternatives
(N
));
5164 while Present
(Alt
) loop
5166 Alt_Expr
: Node_Id
:= Expression
(Alt
);
5167 Alt_Loc
: constant Source_Ptr
:= Sloc
(Alt_Expr
);
5171 -- Take the unrestricted access of the expression value for non-
5172 -- scalar types. This approach avoids big copies and covers the
5173 -- limited and unconstrained cases.
5176 -- AX'Unrestricted_Access
5178 if not Is_Copy_Type
(Typ
) then
5180 Make_Attribute_Reference
(Alt_Loc
,
5181 Prefix
=> Relocate_Node
(Alt_Expr
),
5182 Attribute_Name
=> Name_Unrestricted_Access
);
5186 -- return AX['Unrestricted_Access];
5188 if Optimize_Return_Stmt
then
5190 Make_Simple_Return_Statement
(Alt_Loc
,
5191 Expression
=> Alt_Expr
));
5194 -- Target := AX['Unrestricted_Access];
5198 Make_Assignment_Statement
(Alt_Loc
,
5199 Name
=> New_Occurrence_Of
(Target
, Loc
),
5200 Expression
=> Alt_Expr
));
5203 -- Propagate declarations inserted in the node by Insert_Actions
5204 -- (for example, temporaries generated to remove side effects).
5205 -- These actions must remain attached to the alternative, given
5206 -- that they are generated by the corresponding expression.
5208 if Present
(Actions
(Alt
)) then
5209 Prepend_List
(Actions
(Alt
), Stmts
);
5212 -- Finalize any transient objects on exit from the alternative.
5213 -- This is done only in the return optimization case because
5214 -- otherwise the case expression is converted into an expression
5215 -- with actions which already contains this form of processing.
5217 if Optimize_Return_Stmt
then
5218 Process_If_Case_Statements
(N
, Stmts
);
5222 (Alternatives
(Case_Stmt
),
5223 Make_Case_Statement_Alternative
(Sloc
(Alt
),
5224 Discrete_Choices
=> Discrete_Choices
(Alt
),
5225 Statements
=> Stmts
));
5231 -- Rewrite the parent return statement as a case statement
5233 if Optimize_Return_Stmt
then
5234 Rewrite
(Par
, Case_Stmt
);
5237 -- Otherwise convert the case expression into an expression with actions
5240 Append_To
(Acts
, Case_Stmt
);
5242 if Is_Copy_Type
(Typ
) then
5243 Expr
:= New_Occurrence_Of
(Target
, Loc
);
5247 Make_Explicit_Dereference
(Loc
,
5248 Prefix
=> New_Occurrence_Of
(Target
, Loc
));
5254 -- in Target[.all] end;
5257 Make_Expression_With_Actions
(Loc
,
5261 Analyze_And_Resolve
(N
, Typ
);
5263 end Expand_N_Case_Expression
;
5265 -----------------------------------
5266 -- Expand_N_Explicit_Dereference --
5267 -----------------------------------
5269 procedure Expand_N_Explicit_Dereference
(N
: Node_Id
) is
5271 -- Insert explicit dereference call for the checked storage pool case
5273 Insert_Dereference_Action
(Prefix
(N
));
5275 -- If the type is an Atomic type for which Atomic_Sync is enabled, then
5276 -- we set the atomic sync flag.
5278 if Is_Atomic
(Etype
(N
))
5279 and then not Atomic_Synchronization_Disabled
(Etype
(N
))
5281 Activate_Atomic_Synchronization
(N
);
5283 end Expand_N_Explicit_Dereference
;
5285 --------------------------------------
5286 -- Expand_N_Expression_With_Actions --
5287 --------------------------------------
5289 procedure Expand_N_Expression_With_Actions
(N
: Node_Id
) is
5290 Acts
: constant List_Id
:= Actions
(N
);
5292 procedure Force_Boolean_Evaluation
(Expr
: Node_Id
);
5293 -- Force the evaluation of Boolean expression Expr
5295 function Process_Action
(Act
: Node_Id
) return Traverse_Result
;
5296 -- Inspect and process a single action of an expression_with_actions for
5297 -- transient objects. If such objects are found, the routine generates
5298 -- code to clean them up when the context of the expression is evaluated
5301 ------------------------------
5302 -- Force_Boolean_Evaluation --
5303 ------------------------------
5305 procedure Force_Boolean_Evaluation
(Expr
: Node_Id
) is
5306 Loc
: constant Source_Ptr
:= Sloc
(N
);
5307 Flag_Decl
: Node_Id
;
5308 Flag_Id
: Entity_Id
;
5311 -- Relocate the expression to the actions list by capturing its value
5312 -- in a Boolean flag. Generate:
5313 -- Flag : constant Boolean := Expr;
5315 Flag_Id
:= Make_Temporary
(Loc
, 'F');
5318 Make_Object_Declaration
(Loc
,
5319 Defining_Identifier
=> Flag_Id
,
5320 Constant_Present
=> True,
5321 Object_Definition
=> New_Occurrence_Of
(Standard_Boolean
, Loc
),
5322 Expression
=> Relocate_Node
(Expr
));
5324 Append
(Flag_Decl
, Acts
);
5325 Analyze
(Flag_Decl
);
5327 -- Replace the expression with a reference to the flag
5329 Rewrite
(Expression
(N
), New_Occurrence_Of
(Flag_Id
, Loc
));
5330 Analyze
(Expression
(N
));
5331 end Force_Boolean_Evaluation
;
5333 --------------------
5334 -- Process_Action --
5335 --------------------
5337 function Process_Action
(Act
: Node_Id
) return Traverse_Result
is
5339 if Nkind
(Act
) = N_Object_Declaration
5340 and then Is_Finalizable_Transient
(Act
, N
)
5342 Process_Transient_In_Expression
(Act
, N
, Acts
);
5345 -- Avoid processing temporary function results multiple times when
5346 -- dealing with nested expression_with_actions.
5348 elsif Nkind
(Act
) = N_Expression_With_Actions
then
5351 -- Do not process temporary function results in loops. This is done
5352 -- by Expand_N_Loop_Statement and Build_Finalizer.
5354 elsif Nkind
(Act
) = N_Loop_Statement
then
5361 procedure Process_Single_Action
is new Traverse_Proc
(Process_Action
);
5367 -- Start of processing for Expand_N_Expression_With_Actions
5370 -- Do not evaluate the expression when it denotes an entity because the
5371 -- expression_with_actions node will be replaced by the reference.
5373 if Is_Entity_Name
(Expression
(N
)) then
5376 -- Do not evaluate the expression when there are no actions because the
5377 -- expression_with_actions node will be replaced by the expression.
5379 elsif No
(Acts
) or else Is_Empty_List
(Acts
) then
5382 -- Force the evaluation of the expression by capturing its value in a
5383 -- temporary. This ensures that aliases of transient objects do not leak
5384 -- to the expression of the expression_with_actions node:
5387 -- Trans_Id : Ctrl_Typ := ...;
5388 -- Alias : ... := Trans_Id;
5389 -- in ... Alias ... end;
5391 -- In the example above, Trans_Id cannot be finalized at the end of the
5392 -- actions list because this may affect the alias and the final value of
5393 -- the expression_with_actions. Forcing the evaluation encapsulates the
5394 -- reference to the Alias within the actions list:
5397 -- Trans_Id : Ctrl_Typ := ...;
5398 -- Alias : ... := Trans_Id;
5399 -- Val : constant Boolean := ... Alias ...;
5400 -- <finalize Trans_Id>
5403 -- Once this transformation is performed, it is safe to finalize the
5404 -- transient object at the end of the actions list.
5406 -- Note that Force_Evaluation does not remove side effects in operators
5407 -- because it assumes that all operands are evaluated and side effect
5408 -- free. This is not the case when an operand depends implicitly on the
5409 -- transient object through the use of access types.
5411 elsif Is_Boolean_Type
(Etype
(Expression
(N
))) then
5412 Force_Boolean_Evaluation
(Expression
(N
));
5414 -- The expression of an expression_with_actions node may not necessarily
5415 -- be Boolean when the node appears in an if expression. In this case do
5416 -- the usual forced evaluation to encapsulate potential aliasing.
5419 Force_Evaluation
(Expression
(N
));
5422 -- Process all transient objects found within the actions of the EWA
5425 Act
:= First
(Acts
);
5426 while Present
(Act
) loop
5427 Process_Single_Action
(Act
);
5431 -- Deal with case where there are no actions. In this case we simply
5432 -- rewrite the node with its expression since we don't need the actions
5433 -- and the specification of this node does not allow a null action list.
5435 -- Note: we use Rewrite instead of Replace, because Codepeer is using
5436 -- the expanded tree and relying on being able to retrieve the original
5437 -- tree in cases like this. This raises a whole lot of issues of whether
5438 -- we have problems elsewhere, which will be addressed in the future???
5440 if Is_Empty_List
(Acts
) then
5441 Rewrite
(N
, Relocate_Node
(Expression
(N
)));
5443 end Expand_N_Expression_With_Actions
;
5445 ----------------------------
5446 -- Expand_N_If_Expression --
5447 ----------------------------
5449 -- Deal with limited types and condition actions
5451 procedure Expand_N_If_Expression
(N
: Node_Id
) is
5452 Cond
: constant Node_Id
:= First
(Expressions
(N
));
5453 Loc
: constant Source_Ptr
:= Sloc
(N
);
5454 Thenx
: constant Node_Id
:= Next
(Cond
);
5455 Elsex
: constant Node_Id
:= Next
(Thenx
);
5456 Typ
: constant Entity_Id
:= Etype
(N
);
5465 -- Check for MINIMIZED/ELIMINATED overflow mode
5467 if Minimized_Eliminated_Overflow_Check
(N
) then
5468 Apply_Arithmetic_Overflow_Check
(N
);
5472 -- Fold at compile time if condition known. We have already folded
5473 -- static if expressions, but it is possible to fold any case in which
5474 -- the condition is known at compile time, even though the result is
5477 -- Note that we don't do the fold of such cases in Sem_Elab because
5478 -- it can cause infinite loops with the expander adding a conditional
5479 -- expression, and Sem_Elab circuitry removing it repeatedly.
5481 if Compile_Time_Known_Value
(Cond
) then
5483 function Fold_Known_Value
(Cond
: Node_Id
) return Boolean;
5484 -- Fold at compile time. Assumes condition known. Return True if
5485 -- folding occurred, meaning we're done.
5487 ----------------------
5488 -- Fold_Known_Value --
5489 ----------------------
5491 function Fold_Known_Value
(Cond
: Node_Id
) return Boolean is
5493 if Is_True
(Expr_Value
(Cond
)) then
5495 Actions
:= Then_Actions
(N
);
5498 Actions
:= Else_Actions
(N
);
5503 if Present
(Actions
) then
5505 -- To minimize the use of Expression_With_Actions, just skip
5506 -- the optimization as it is not critical for correctness.
5508 if Minimize_Expression_With_Actions
then
5513 Make_Expression_With_Actions
(Loc
,
5514 Expression
=> Relocate_Node
(Expr
),
5515 Actions
=> Actions
));
5516 Analyze_And_Resolve
(N
, Typ
);
5519 Rewrite
(N
, Relocate_Node
(Expr
));
5522 -- Note that the result is never static (legitimate cases of
5523 -- static if expressions were folded in Sem_Eval).
5525 Set_Is_Static_Expression
(N
, False);
5527 end Fold_Known_Value
;
5530 if Fold_Known_Value
(Cond
) then
5536 -- If the type is limited, and the back end does not handle limited
5537 -- types, then we expand as follows to avoid the possibility of
5538 -- improper copying.
5540 -- type Ptr is access all Typ;
5544 -- Cnn := then-expr'Unrestricted_Access;
5547 -- Cnn := else-expr'Unrestricted_Access;
5550 -- and replace the if expression by a reference to Cnn.all.
5552 -- This special case can be skipped if the back end handles limited
5553 -- types properly and ensures that no incorrect copies are made.
5555 if Is_By_Reference_Type
(Typ
)
5556 and then not Back_End_Handles_Limited_Types
5558 -- When the "then" or "else" expressions involve controlled function
5559 -- calls, generated temporaries are chained on the corresponding list
5560 -- of actions. These temporaries need to be finalized after the if
5561 -- expression is evaluated.
5563 Process_If_Case_Statements
(N
, Then_Actions
(N
));
5564 Process_If_Case_Statements
(N
, Else_Actions
(N
));
5567 Cnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'C', N
);
5568 Ptr_Typ
: constant Entity_Id
:= Make_Temporary
(Loc
, 'A');
5572 -- type Ann is access all Typ;
5575 Make_Full_Type_Declaration
(Loc
,
5576 Defining_Identifier
=> Ptr_Typ
,
5578 Make_Access_To_Object_Definition
(Loc
,
5579 All_Present
=> True,
5580 Subtype_Indication
=> New_Occurrence_Of
(Typ
, Loc
))));
5586 Make_Object_Declaration
(Loc
,
5587 Defining_Identifier
=> Cnn
,
5588 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
));
5592 -- Cnn := <Thenx>'Unrestricted_Access;
5594 -- Cnn := <Elsex>'Unrestricted_Access;
5598 Make_Implicit_If_Statement
(N
,
5599 Condition
=> Relocate_Node
(Cond
),
5600 Then_Statements
=> New_List
(
5601 Make_Assignment_Statement
(Sloc
(Thenx
),
5602 Name
=> New_Occurrence_Of
(Cnn
, Sloc
(Thenx
)),
5604 Make_Attribute_Reference
(Loc
,
5605 Prefix
=> Relocate_Node
(Thenx
),
5606 Attribute_Name
=> Name_Unrestricted_Access
))),
5608 Else_Statements
=> New_List
(
5609 Make_Assignment_Statement
(Sloc
(Elsex
),
5610 Name
=> New_Occurrence_Of
(Cnn
, Sloc
(Elsex
)),
5612 Make_Attribute_Reference
(Loc
,
5613 Prefix
=> Relocate_Node
(Elsex
),
5614 Attribute_Name
=> Name_Unrestricted_Access
))));
5616 -- Preserve the original context for which the if statement is
5617 -- being generated. This is needed by the finalization machinery
5618 -- to prevent the premature finalization of controlled objects
5619 -- found within the if statement.
5621 Set_From_Conditional_Expression
(New_If
);
5624 Make_Explicit_Dereference
(Loc
,
5625 Prefix
=> New_Occurrence_Of
(Cnn
, Loc
));
5628 -- If the result is an unconstrained array and the if expression is in a
5629 -- context other than the initializing expression of the declaration of
5630 -- an object, then we pull out the if expression as follows:
5632 -- Cnn : constant typ := if-expression
5634 -- and then replace the if expression with an occurrence of Cnn. This
5635 -- avoids the need in the back end to create on-the-fly variable length
5636 -- temporaries (which it cannot do!)
5638 -- Note that the test for being in an object declaration avoids doing an
5639 -- unnecessary expansion, and also avoids infinite recursion.
5641 elsif Is_Array_Type
(Typ
) and then not Is_Constrained
(Typ
)
5642 and then (Nkind
(Parent
(N
)) /= N_Object_Declaration
5643 or else Expression
(Parent
(N
)) /= N
)
5646 Cnn
: constant Node_Id
:= Make_Temporary
(Loc
, 'C', N
);
5650 Make_Object_Declaration
(Loc
,
5651 Defining_Identifier
=> Cnn
,
5652 Constant_Present
=> True,
5653 Object_Definition
=> New_Occurrence_Of
(Typ
, Loc
),
5654 Expression
=> Relocate_Node
(N
),
5655 Has_Init_Expression
=> True));
5657 Rewrite
(N
, New_Occurrence_Of
(Cnn
, Loc
));
5661 -- For other types, we only need to expand if there are other actions
5662 -- associated with either branch.
5664 elsif Present
(Then_Actions
(N
)) or else Present
(Else_Actions
(N
)) then
5666 -- We now wrap the actions into the appropriate expression
5668 if Minimize_Expression_With_Actions
5669 and then (Is_Elementary_Type
(Underlying_Type
(Typ
))
5670 or else Is_Constrained
(Underlying_Type
(Typ
)))
5672 -- If we can't use N_Expression_With_Actions nodes, then we insert
5673 -- the following sequence of actions (using Insert_Actions):
5678 -- Cnn := then-expr;
5684 -- and replace the if expression by a reference to Cnn
5687 Cnn
: constant Node_Id
:= Make_Temporary
(Loc
, 'C', N
);
5691 Make_Object_Declaration
(Loc
,
5692 Defining_Identifier
=> Cnn
,
5693 Object_Definition
=> New_Occurrence_Of
(Typ
, Loc
));
5696 Make_Implicit_If_Statement
(N
,
5697 Condition
=> Relocate_Node
(Cond
),
5699 Then_Statements
=> New_List
(
5700 Make_Assignment_Statement
(Sloc
(Thenx
),
5701 Name
=> New_Occurrence_Of
(Cnn
, Sloc
(Thenx
)),
5702 Expression
=> Relocate_Node
(Thenx
))),
5704 Else_Statements
=> New_List
(
5705 Make_Assignment_Statement
(Sloc
(Elsex
),
5706 Name
=> New_Occurrence_Of
(Cnn
, Sloc
(Elsex
)),
5707 Expression
=> Relocate_Node
(Elsex
))));
5709 Set_Assignment_OK
(Name
(First
(Then_Statements
(New_If
))));
5710 Set_Assignment_OK
(Name
(First
(Else_Statements
(New_If
))));
5712 New_N
:= New_Occurrence_Of
(Cnn
, Loc
);
5715 -- Regular path using Expression_With_Actions
5718 if Present
(Then_Actions
(N
)) then
5720 Make_Expression_With_Actions
(Sloc
(Thenx
),
5721 Actions
=> Then_Actions
(N
),
5722 Expression
=> Relocate_Node
(Thenx
)));
5724 Set_Then_Actions
(N
, No_List
);
5725 Analyze_And_Resolve
(Thenx
, Typ
);
5728 if Present
(Else_Actions
(N
)) then
5730 Make_Expression_With_Actions
(Sloc
(Elsex
),
5731 Actions
=> Else_Actions
(N
),
5732 Expression
=> Relocate_Node
(Elsex
)));
5734 Set_Else_Actions
(N
, No_List
);
5735 Analyze_And_Resolve
(Elsex
, Typ
);
5741 -- If no actions then no expansion needed, gigi will handle it using the
5742 -- same approach as a C conditional expression.
5748 -- Fall through here for either the limited expansion, or the case of
5749 -- inserting actions for nonlimited types. In both these cases, we must
5750 -- move the SLOC of the parent If statement to the newly created one and
5751 -- change it to the SLOC of the expression which, after expansion, will
5752 -- correspond to what is being evaluated.
5754 if Present
(Parent
(N
)) and then Nkind
(Parent
(N
)) = N_If_Statement
then
5755 Set_Sloc
(New_If
, Sloc
(Parent
(N
)));
5756 Set_Sloc
(Parent
(N
), Loc
);
5759 -- Make sure Then_Actions and Else_Actions are appropriately moved
5760 -- to the new if statement.
5762 if Present
(Then_Actions
(N
)) then
5764 (First
(Then_Statements
(New_If
)), Then_Actions
(N
));
5767 if Present
(Else_Actions
(N
)) then
5769 (First
(Else_Statements
(New_If
)), Else_Actions
(N
));
5772 Insert_Action
(N
, Decl
);
5773 Insert_Action
(N
, New_If
);
5775 Analyze_And_Resolve
(N
, Typ
);
5776 end Expand_N_If_Expression
;
5782 procedure Expand_N_In
(N
: Node_Id
) is
5783 Loc
: constant Source_Ptr
:= Sloc
(N
);
5784 Restyp
: constant Entity_Id
:= Etype
(N
);
5785 Lop
: constant Node_Id
:= Left_Opnd
(N
);
5786 Rop
: constant Node_Id
:= Right_Opnd
(N
);
5787 Static
: constant Boolean := Is_OK_Static_Expression
(N
);
5789 procedure Substitute_Valid_Check
;
5790 -- Replaces node N by Lop'Valid. This is done when we have an explicit
5791 -- test for the left operand being in range of its subtype.
5793 ----------------------------
5794 -- Substitute_Valid_Check --
5795 ----------------------------
5797 procedure Substitute_Valid_Check
is
5798 function Is_OK_Object_Reference
(Nod
: Node_Id
) return Boolean;
5799 -- Determine whether arbitrary node Nod denotes a source object that
5800 -- may safely act as prefix of attribute 'Valid.
5802 ----------------------------
5803 -- Is_OK_Object_Reference --
5804 ----------------------------
5806 function Is_OK_Object_Reference
(Nod
: Node_Id
) return Boolean is
5810 -- Inspect the original operand
5812 Obj_Ref
:= Original_Node
(Nod
);
5814 -- The object reference must be a source construct, otherwise the
5815 -- codefix suggestion may refer to nonexistent code from a user
5818 if Comes_From_Source
(Obj_Ref
) then
5820 -- Recover the actual object reference. There may be more cases
5824 if Nkind_In
(Obj_Ref
, N_Type_Conversion
,
5825 N_Unchecked_Type_Conversion
)
5827 Obj_Ref
:= Expression
(Obj_Ref
);
5833 return Is_Object_Reference
(Obj_Ref
);
5837 end Is_OK_Object_Reference
;
5839 -- Start of processing for Substitute_Valid_Check
5843 Make_Attribute_Reference
(Loc
,
5844 Prefix
=> Relocate_Node
(Lop
),
5845 Attribute_Name
=> Name_Valid
));
5847 Analyze_And_Resolve
(N
, Restyp
);
5849 -- Emit a warning when the left-hand operand of the membership test
5850 -- is a source object, otherwise the use of attribute 'Valid would be
5851 -- illegal. The warning is not given when overflow checking is either
5852 -- MINIMIZED or ELIMINATED, as the danger of optimization has been
5853 -- eliminated above.
5855 if Is_OK_Object_Reference
(Lop
)
5856 and then Overflow_Check_Mode
not in Minimized_Or_Eliminated
5859 ("??explicit membership test may be optimized away", N
);
5860 Error_Msg_N
-- CODEFIX
5861 ("\??use ''Valid attribute instead", N
);
5863 end Substitute_Valid_Check
;
5870 -- Start of processing for Expand_N_In
5873 -- If set membership case, expand with separate procedure
5875 if Present
(Alternatives
(N
)) then
5876 Expand_Set_Membership
(N
);
5880 -- Not set membership, proceed with expansion
5882 Ltyp
:= Etype
(Left_Opnd
(N
));
5883 Rtyp
:= Etype
(Right_Opnd
(N
));
5885 -- If MINIMIZED/ELIMINATED overflow mode and type is a signed integer
5886 -- type, then expand with a separate procedure. Note the use of the
5887 -- flag No_Minimize_Eliminate to prevent infinite recursion.
5889 if Overflow_Check_Mode
in Minimized_Or_Eliminated
5890 and then Is_Signed_Integer_Type
(Ltyp
)
5891 and then not No_Minimize_Eliminate
(N
)
5893 Expand_Membership_Minimize_Eliminate_Overflow
(N
);
5897 -- Check case of explicit test for an expression in range of its
5898 -- subtype. This is suspicious usage and we replace it with a 'Valid
5899 -- test and give a warning for scalar types.
5901 if Is_Scalar_Type
(Ltyp
)
5903 -- Only relevant for source comparisons
5905 and then Comes_From_Source
(N
)
5907 -- In floating-point this is a standard way to check for finite values
5908 -- and using 'Valid would typically be a pessimization.
5910 and then not Is_Floating_Point_Type
(Ltyp
)
5912 -- Don't give the message unless right operand is a type entity and
5913 -- the type of the left operand matches this type. Note that this
5914 -- eliminates the cases where MINIMIZED/ELIMINATED mode overflow
5915 -- checks have changed the type of the left operand.
5917 and then Nkind
(Rop
) in N_Has_Entity
5918 and then Ltyp
= Entity
(Rop
)
5920 -- Skip this for predicated types, where such expressions are a
5921 -- reasonable way of testing if something meets the predicate.
5923 and then not Present
(Predicate_Function
(Ltyp
))
5925 Substitute_Valid_Check
;
5929 -- Do validity check on operands
5931 if Validity_Checks_On
and Validity_Check_Operands
then
5932 Ensure_Valid
(Left_Opnd
(N
));
5933 Validity_Check_Range
(Right_Opnd
(N
));
5936 -- Case of explicit range
5938 if Nkind
(Rop
) = N_Range
then
5940 Lo
: constant Node_Id
:= Low_Bound
(Rop
);
5941 Hi
: constant Node_Id
:= High_Bound
(Rop
);
5943 Lo_Orig
: constant Node_Id
:= Original_Node
(Lo
);
5944 Hi_Orig
: constant Node_Id
:= Original_Node
(Hi
);
5946 Lcheck
: Compare_Result
;
5947 Ucheck
: Compare_Result
;
5949 Warn1
: constant Boolean :=
5950 Constant_Condition_Warnings
5951 and then Comes_From_Source
(N
)
5952 and then not In_Instance
;
5953 -- This must be true for any of the optimization warnings, we
5954 -- clearly want to give them only for source with the flag on. We
5955 -- also skip these warnings in an instance since it may be the
5956 -- case that different instantiations have different ranges.
5958 Warn2
: constant Boolean :=
5960 and then Nkind
(Original_Node
(Rop
)) = N_Range
5961 and then Is_Integer_Type
(Etype
(Lo
));
5962 -- For the case where only one bound warning is elided, we also
5963 -- insist on an explicit range and an integer type. The reason is
5964 -- that the use of enumeration ranges including an end point is
5965 -- common, as is the use of a subtype name, one of whose bounds is
5966 -- the same as the type of the expression.
5969 -- If test is explicit x'First .. x'Last, replace by valid check
5971 -- Could use some individual comments for this complex test ???
5973 if Is_Scalar_Type
(Ltyp
)
5975 -- And left operand is X'First where X matches left operand
5976 -- type (this eliminates cases of type mismatch, including
5977 -- the cases where ELIMINATED/MINIMIZED mode has changed the
5978 -- type of the left operand.
5980 and then Nkind
(Lo_Orig
) = N_Attribute_Reference
5981 and then Attribute_Name
(Lo_Orig
) = Name_First
5982 and then Nkind
(Prefix
(Lo_Orig
)) in N_Has_Entity
5983 and then Entity
(Prefix
(Lo_Orig
)) = Ltyp
5985 -- Same tests for right operand
5987 and then Nkind
(Hi_Orig
) = N_Attribute_Reference
5988 and then Attribute_Name
(Hi_Orig
) = Name_Last
5989 and then Nkind
(Prefix
(Hi_Orig
)) in N_Has_Entity
5990 and then Entity
(Prefix
(Hi_Orig
)) = Ltyp
5992 -- Relevant only for source cases
5994 and then Comes_From_Source
(N
)
5996 Substitute_Valid_Check
;
6000 -- If bounds of type are known at compile time, and the end points
6001 -- are known at compile time and identical, this is another case
6002 -- for substituting a valid test. We only do this for discrete
6003 -- types, since it won't arise in practice for float types.
6005 if Comes_From_Source
(N
)
6006 and then Is_Discrete_Type
(Ltyp
)
6007 and then Compile_Time_Known_Value
(Type_High_Bound
(Ltyp
))
6008 and then Compile_Time_Known_Value
(Type_Low_Bound
(Ltyp
))
6009 and then Compile_Time_Known_Value
(Lo
)
6010 and then Compile_Time_Known_Value
(Hi
)
6011 and then Expr_Value
(Type_High_Bound
(Ltyp
)) = Expr_Value
(Hi
)
6012 and then Expr_Value
(Type_Low_Bound
(Ltyp
)) = Expr_Value
(Lo
)
6014 -- Kill warnings in instances, since they may be cases where we
6015 -- have a test in the generic that makes sense with some types
6016 -- and not with other types.
6018 and then not In_Instance
6020 Substitute_Valid_Check
;
6024 -- If we have an explicit range, do a bit of optimization based on
6025 -- range analysis (we may be able to kill one or both checks).
6027 Lcheck
:= Compile_Time_Compare
(Lop
, Lo
, Assume_Valid
=> False);
6028 Ucheck
:= Compile_Time_Compare
(Lop
, Hi
, Assume_Valid
=> False);
6030 -- If either check is known to fail, replace result by False since
6031 -- the other check does not matter. Preserve the static flag for
6032 -- legality checks, because we are constant-folding beyond RM 4.9.
6034 if Lcheck
= LT
or else Ucheck
= GT
then
6036 Error_Msg_N
("?c?range test optimized away", N
);
6037 Error_Msg_N
("\?c?value is known to be out of range", N
);
6040 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
6041 Analyze_And_Resolve
(N
, Restyp
);
6042 Set_Is_Static_Expression
(N
, Static
);
6045 -- If both checks are known to succeed, replace result by True,
6046 -- since we know we are in range.
6048 elsif Lcheck
in Compare_GE
and then Ucheck
in Compare_LE
then
6050 Error_Msg_N
("?c?range test optimized away", N
);
6051 Error_Msg_N
("\?c?value is known to be in range", N
);
6054 Rewrite
(N
, New_Occurrence_Of
(Standard_True
, Loc
));
6055 Analyze_And_Resolve
(N
, Restyp
);
6056 Set_Is_Static_Expression
(N
, Static
);
6059 -- If lower bound check succeeds and upper bound check is not
6060 -- known to succeed or fail, then replace the range check with
6061 -- a comparison against the upper bound.
6063 elsif Lcheck
in Compare_GE
then
6064 if Warn2
and then not In_Instance
then
6065 Error_Msg_N
("??lower bound test optimized away", Lo
);
6066 Error_Msg_N
("\??value is known to be in range", Lo
);
6072 Right_Opnd
=> High_Bound
(Rop
)));
6073 Analyze_And_Resolve
(N
, Restyp
);
6076 -- If upper bound check succeeds and lower bound check is not
6077 -- known to succeed or fail, then replace the range check with
6078 -- a comparison against the lower bound.
6080 elsif Ucheck
in Compare_LE
then
6081 if Warn2
and then not In_Instance
then
6082 Error_Msg_N
("??upper bound test optimized away", Hi
);
6083 Error_Msg_N
("\??value is known to be in range", Hi
);
6089 Right_Opnd
=> Low_Bound
(Rop
)));
6090 Analyze_And_Resolve
(N
, Restyp
);
6094 -- We couldn't optimize away the range check, but there is one
6095 -- more issue. If we are checking constant conditionals, then we
6096 -- see if we can determine the outcome assuming everything is
6097 -- valid, and if so give an appropriate warning.
6099 if Warn1
and then not Assume_No_Invalid_Values
then
6100 Lcheck
:= Compile_Time_Compare
(Lop
, Lo
, Assume_Valid
=> True);
6101 Ucheck
:= Compile_Time_Compare
(Lop
, Hi
, Assume_Valid
=> True);
6103 -- Result is out of range for valid value
6105 if Lcheck
= LT
or else Ucheck
= GT
then
6107 ("?c?value can only be in range if it is invalid", N
);
6109 -- Result is in range for valid value
6111 elsif Lcheck
in Compare_GE
and then Ucheck
in Compare_LE
then
6113 ("?c?value can only be out of range if it is invalid", N
);
6115 -- Lower bound check succeeds if value is valid
6117 elsif Warn2
and then Lcheck
in Compare_GE
then
6119 ("?c?lower bound check only fails if it is invalid", Lo
);
6121 -- Upper bound check succeeds if value is valid
6123 elsif Warn2
and then Ucheck
in Compare_LE
then
6125 ("?c?upper bound check only fails for invalid values", Hi
);
6130 -- For all other cases of an explicit range, nothing to be done
6134 -- Here right operand is a subtype mark
6138 Typ
: Entity_Id
:= Etype
(Rop
);
6139 Is_Acc
: constant Boolean := Is_Access_Type
(Typ
);
6140 Cond
: Node_Id
:= Empty
;
6142 Obj
: Node_Id
:= Lop
;
6143 SCIL_Node
: Node_Id
;
6146 Remove_Side_Effects
(Obj
);
6148 -- For tagged type, do tagged membership operation
6150 if Is_Tagged_Type
(Typ
) then
6152 -- No expansion will be performed for VM targets, as the VM
6153 -- back ends will handle the membership tests directly.
6155 if Tagged_Type_Expansion
then
6156 Tagged_Membership
(N
, SCIL_Node
, New_N
);
6158 Analyze_And_Resolve
(N
, Restyp
, Suppress
=> All_Checks
);
6160 -- Update decoration of relocated node referenced by the
6163 if Generate_SCIL
and then Present
(SCIL_Node
) then
6164 Set_SCIL_Node
(N
, SCIL_Node
);
6170 -- If type is scalar type, rewrite as x in t'First .. t'Last.
6171 -- This reason we do this is that the bounds may have the wrong
6172 -- type if they come from the original type definition. Also this
6173 -- way we get all the processing above for an explicit range.
6175 -- Don't do this for predicated types, since in this case we
6176 -- want to check the predicate.
6178 elsif Is_Scalar_Type
(Typ
) then
6179 if No
(Predicate_Function
(Typ
)) then
6183 Make_Attribute_Reference
(Loc
,
6184 Attribute_Name
=> Name_First
,
6185 Prefix
=> New_Occurrence_Of
(Typ
, Loc
)),
6188 Make_Attribute_Reference
(Loc
,
6189 Attribute_Name
=> Name_Last
,
6190 Prefix
=> New_Occurrence_Of
(Typ
, Loc
))));
6191 Analyze_And_Resolve
(N
, Restyp
);
6196 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
6197 -- a membership test if the subtype mark denotes a constrained
6198 -- Unchecked_Union subtype and the expression lacks inferable
6201 elsif Is_Unchecked_Union
(Base_Type
(Typ
))
6202 and then Is_Constrained
(Typ
)
6203 and then not Has_Inferable_Discriminants
(Lop
)
6206 Make_Raise_Program_Error
(Loc
,
6207 Reason
=> PE_Unchecked_Union_Restriction
));
6209 -- Prevent Gigi from generating incorrect code by rewriting the
6210 -- test as False. What is this undocumented thing about ???
6212 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
6216 -- Here we have a non-scalar type
6219 Typ
:= Designated_Type
(Typ
);
6222 if not Is_Constrained
(Typ
) then
6223 Rewrite
(N
, New_Occurrence_Of
(Standard_True
, Loc
));
6224 Analyze_And_Resolve
(N
, Restyp
);
6226 -- For the constrained array case, we have to check the subscripts
6227 -- for an exact match if the lengths are non-zero (the lengths
6228 -- must match in any case).
6230 elsif Is_Array_Type
(Typ
) then
6231 Check_Subscripts
: declare
6232 function Build_Attribute_Reference
6235 Dim
: Nat
) return Node_Id
;
6236 -- Build attribute reference E'Nam (Dim)
6238 -------------------------------
6239 -- Build_Attribute_Reference --
6240 -------------------------------
6242 function Build_Attribute_Reference
6245 Dim
: Nat
) return Node_Id
6249 Make_Attribute_Reference
(Loc
,
6251 Attribute_Name
=> Nam
,
6252 Expressions
=> New_List
(
6253 Make_Integer_Literal
(Loc
, Dim
)));
6254 end Build_Attribute_Reference
;
6256 -- Start of processing for Check_Subscripts
6259 for J
in 1 .. Number_Dimensions
(Typ
) loop
6260 Evolve_And_Then
(Cond
,
6263 Build_Attribute_Reference
6264 (Duplicate_Subexpr_No_Checks
(Obj
),
6267 Build_Attribute_Reference
6268 (New_Occurrence_Of
(Typ
, Loc
), Name_First
, J
)));
6270 Evolve_And_Then
(Cond
,
6273 Build_Attribute_Reference
6274 (Duplicate_Subexpr_No_Checks
(Obj
),
6277 Build_Attribute_Reference
6278 (New_Occurrence_Of
(Typ
, Loc
), Name_Last
, J
)));
6287 Right_Opnd
=> Make_Null
(Loc
)),
6288 Right_Opnd
=> Cond
);
6292 Analyze_And_Resolve
(N
, Restyp
);
6293 end Check_Subscripts
;
6295 -- These are the cases where constraint checks may be required,
6296 -- e.g. records with possible discriminants
6299 -- Expand the test into a series of discriminant comparisons.
6300 -- The expression that is built is the negation of the one that
6301 -- is used for checking discriminant constraints.
6303 Obj
:= Relocate_Node
(Left_Opnd
(N
));
6305 if Has_Discriminants
(Typ
) then
6306 Cond
:= Make_Op_Not
(Loc
,
6307 Right_Opnd
=> Build_Discriminant_Checks
(Obj
, Typ
));
6310 Cond
:= Make_Or_Else
(Loc
,
6314 Right_Opnd
=> Make_Null
(Loc
)),
6315 Right_Opnd
=> Cond
);
6319 Cond
:= New_Occurrence_Of
(Standard_True
, Loc
);
6323 Analyze_And_Resolve
(N
, Restyp
);
6326 -- Ada 2012 (AI05-0149): Handle membership tests applied to an
6327 -- expression of an anonymous access type. This can involve an
6328 -- accessibility test and a tagged type membership test in the
6329 -- case of tagged designated types.
6331 if Ada_Version
>= Ada_2012
6333 and then Ekind
(Ltyp
) = E_Anonymous_Access_Type
6336 Expr_Entity
: Entity_Id
:= Empty
;
6338 Param_Level
: Node_Id
;
6339 Type_Level
: Node_Id
;
6342 if Is_Entity_Name
(Lop
) then
6343 Expr_Entity
:= Param_Entity
(Lop
);
6345 if not Present
(Expr_Entity
) then
6346 Expr_Entity
:= Entity
(Lop
);
6350 -- If a conversion of the anonymous access value to the
6351 -- tested type would be illegal, then the result is False.
6353 if not Valid_Conversion
6354 (Lop
, Rtyp
, Lop
, Report_Errs
=> False)
6356 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
6357 Analyze_And_Resolve
(N
, Restyp
);
6359 -- Apply an accessibility check if the access object has an
6360 -- associated access level and when the level of the type is
6361 -- less deep than the level of the access parameter. This
6362 -- only occur for access parameters and stand-alone objects
6363 -- of an anonymous access type.
6366 if Present
(Expr_Entity
)
6369 (Effective_Extra_Accessibility
(Expr_Entity
))
6370 and then UI_Gt
(Object_Access_Level
(Lop
),
6371 Type_Access_Level
(Rtyp
))
6375 (Effective_Extra_Accessibility
(Expr_Entity
), Loc
);
6378 Make_Integer_Literal
(Loc
, Type_Access_Level
(Rtyp
));
6380 -- Return True only if the accessibility level of the
6381 -- expression entity is not deeper than the level of
6382 -- the tested access type.
6386 Left_Opnd
=> Relocate_Node
(N
),
6387 Right_Opnd
=> Make_Op_Le
(Loc
,
6388 Left_Opnd
=> Param_Level
,
6389 Right_Opnd
=> Type_Level
)));
6391 Analyze_And_Resolve
(N
);
6394 -- If the designated type is tagged, do tagged membership
6397 -- *** NOTE: we have to check not null before doing the
6398 -- tagged membership test (but maybe that can be done
6399 -- inside Tagged_Membership?).
6401 if Is_Tagged_Type
(Typ
) then
6404 Left_Opnd
=> Relocate_Node
(N
),
6408 Right_Opnd
=> Make_Null
(Loc
))));
6410 -- No expansion will be performed for VM targets, as
6411 -- the VM back ends will handle the membership tests
6414 if Tagged_Type_Expansion
then
6416 -- Note that we have to pass Original_Node, because
6417 -- the membership test might already have been
6418 -- rewritten by earlier parts of membership test.
6421 (Original_Node
(N
), SCIL_Node
, New_N
);
6423 -- Update decoration of relocated node referenced
6424 -- by the SCIL node.
6426 if Generate_SCIL
and then Present
(SCIL_Node
) then
6427 Set_SCIL_Node
(New_N
, SCIL_Node
);
6432 Left_Opnd
=> Relocate_Node
(N
),
6433 Right_Opnd
=> New_N
));
6435 Analyze_And_Resolve
(N
, Restyp
);
6444 -- At this point, we have done the processing required for the basic
6445 -- membership test, but not yet dealt with the predicate.
6449 -- If a predicate is present, then we do the predicate test, but we
6450 -- most certainly want to omit this if we are within the predicate
6451 -- function itself, since otherwise we have an infinite recursion.
6452 -- The check should also not be emitted when testing against a range
6453 -- (the check is only done when the right operand is a subtype; see
6454 -- RM12-4.5.2 (28.1/3-30/3)).
6456 Predicate_Check
: declare
6457 function In_Range_Check
return Boolean;
6458 -- Within an expanded range check that may raise Constraint_Error do
6459 -- not generate a predicate check as well. It is redundant because
6460 -- the context will add an explicit predicate check, and it will
6461 -- raise the wrong exception if it fails.
6463 --------------------
6464 -- In_Range_Check --
6465 --------------------
6467 function In_Range_Check
return Boolean is
6471 while Present
(P
) loop
6472 if Nkind
(P
) = N_Raise_Constraint_Error
then
6475 elsif Nkind
(P
) in N_Statement_Other_Than_Procedure_Call
6476 or else Nkind
(P
) = N_Procedure_Call_Statement
6477 or else Nkind
(P
) in N_Declaration
6490 PFunc
: constant Entity_Id
:= Predicate_Function
(Rtyp
);
6493 -- Start of processing for Predicate_Check
6497 and then Current_Scope
/= PFunc
6498 and then Nkind
(Rop
) /= N_Range
6500 if not In_Range_Check
then
6501 R_Op
:= Make_Predicate_Call
(Rtyp
, Lop
, Mem
=> True);
6503 R_Op
:= New_Occurrence_Of
(Standard_True
, Loc
);
6508 Left_Opnd
=> Relocate_Node
(N
),
6509 Right_Opnd
=> R_Op
));
6511 -- Analyze new expression, mark left operand as analyzed to
6512 -- avoid infinite recursion adding predicate calls. Similarly,
6513 -- suppress further range checks on the call.
6515 Set_Analyzed
(Left_Opnd
(N
));
6516 Analyze_And_Resolve
(N
, Standard_Boolean
, Suppress
=> All_Checks
);
6518 -- All done, skip attempt at compile time determination of result
6522 end Predicate_Check
;
6525 --------------------------------
6526 -- Expand_N_Indexed_Component --
6527 --------------------------------
6529 procedure Expand_N_Indexed_Component
(N
: Node_Id
) is
6530 Loc
: constant Source_Ptr
:= Sloc
(N
);
6531 Typ
: constant Entity_Id
:= Etype
(N
);
6532 P
: constant Node_Id
:= Prefix
(N
);
6533 T
: constant Entity_Id
:= Etype
(P
);
6537 -- A special optimization, if we have an indexed component that is
6538 -- selecting from a slice, then we can eliminate the slice, since, for
6539 -- example, x (i .. j)(k) is identical to x(k). The only difference is
6540 -- the range check required by the slice. The range check for the slice
6541 -- itself has already been generated. The range check for the
6542 -- subscripting operation is ensured by converting the subject to
6543 -- the subtype of the slice.
6545 -- This optimization not only generates better code, avoiding slice
6546 -- messing especially in the packed case, but more importantly bypasses
6547 -- some problems in handling this peculiar case, for example, the issue
6548 -- of dealing specially with object renamings.
6550 if Nkind
(P
) = N_Slice
6552 -- This optimization is disabled for CodePeer because it can transform
6553 -- an index-check constraint_error into a range-check constraint_error
6554 -- and CodePeer cares about that distinction.
6556 and then not CodePeer_Mode
6559 Make_Indexed_Component
(Loc
,
6560 Prefix
=> Prefix
(P
),
6561 Expressions
=> New_List
(
6563 (Etype
(First_Index
(Etype
(P
))),
6564 First
(Expressions
(N
))))));
6565 Analyze_And_Resolve
(N
, Typ
);
6569 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
6570 -- function, then additional actuals must be passed.
6572 if Is_Build_In_Place_Function_Call
(P
) then
6573 Make_Build_In_Place_Call_In_Anonymous_Context
(P
);
6575 -- Ada 2005 (AI-318-02): Specialization of the previous case for prefix
6576 -- containing build-in-place function calls whose returned object covers
6579 elsif Present
(Unqual_BIP_Iface_Function_Call
(P
)) then
6580 Make_Build_In_Place_Iface_Call_In_Anonymous_Context
(P
);
6583 -- If the prefix is an access type, then we unconditionally rewrite if
6584 -- as an explicit dereference. This simplifies processing for several
6585 -- cases, including packed array cases and certain cases in which checks
6586 -- must be generated. We used to try to do this only when it was
6587 -- necessary, but it cleans up the code to do it all the time.
6589 if Is_Access_Type
(T
) then
6590 Insert_Explicit_Dereference
(P
);
6591 Analyze_And_Resolve
(P
, Designated_Type
(T
));
6592 Atp
:= Designated_Type
(T
);
6597 -- Generate index and validity checks
6599 Generate_Index_Checks
(N
);
6601 if Validity_Checks_On
and then Validity_Check_Subscripts
then
6602 Apply_Subscript_Validity_Checks
(N
);
6605 -- If selecting from an array with atomic components, and atomic sync
6606 -- is not suppressed for this array type, set atomic sync flag.
6608 if (Has_Atomic_Components
(Atp
)
6609 and then not Atomic_Synchronization_Disabled
(Atp
))
6610 or else (Is_Atomic
(Typ
)
6611 and then not Atomic_Synchronization_Disabled
(Typ
))
6612 or else (Is_Entity_Name
(P
)
6613 and then Has_Atomic_Components
(Entity
(P
))
6614 and then not Atomic_Synchronization_Disabled
(Entity
(P
)))
6616 Activate_Atomic_Synchronization
(N
);
6619 -- All done if the prefix is not a packed array implemented specially
6621 if not (Is_Packed
(Etype
(Prefix
(N
)))
6622 and then Present
(Packed_Array_Impl_Type
(Etype
(Prefix
(N
)))))
6627 -- For packed arrays that are not bit-packed (i.e. the case of an array
6628 -- with one or more index types with a non-contiguous enumeration type),
6629 -- we can always use the normal packed element get circuit.
6631 if not Is_Bit_Packed_Array
(Etype
(Prefix
(N
))) then
6632 Expand_Packed_Element_Reference
(N
);
6636 -- For a reference to a component of a bit packed array, we convert it
6637 -- to a reference to the corresponding Packed_Array_Impl_Type. We only
6638 -- want to do this for simple references, and not for:
6640 -- Left side of assignment, or prefix of left side of assignment, or
6641 -- prefix of the prefix, to handle packed arrays of packed arrays,
6642 -- This case is handled in Exp_Ch5.Expand_N_Assignment_Statement
6644 -- Renaming objects in renaming associations
6645 -- This case is handled when a use of the renamed variable occurs
6647 -- Actual parameters for a procedure call
6648 -- This case is handled in Exp_Ch6.Expand_Actuals
6650 -- The second expression in a 'Read attribute reference
6652 -- The prefix of an address or bit or size attribute reference
6654 -- The following circuit detects these exceptions. Note that we need to
6655 -- deal with implicit dereferences when climbing up the parent chain,
6656 -- with the additional difficulty that the type of parents may have yet
6657 -- to be resolved since prefixes are usually resolved first.
6660 Child
: Node_Id
:= N
;
6661 Parnt
: Node_Id
:= Parent
(N
);
6665 if Nkind
(Parnt
) = N_Unchecked_Expression
then
6668 elsif Nkind_In
(Parnt
, N_Object_Renaming_Declaration
,
6669 N_Procedure_Call_Statement
)
6670 or else (Nkind
(Parnt
) = N_Parameter_Association
6672 Nkind
(Parent
(Parnt
)) = N_Procedure_Call_Statement
)
6676 elsif Nkind
(Parnt
) = N_Attribute_Reference
6677 and then Nam_In
(Attribute_Name
(Parnt
), Name_Address
,
6680 and then Prefix
(Parnt
) = Child
6684 elsif Nkind
(Parnt
) = N_Assignment_Statement
6685 and then Name
(Parnt
) = Child
6689 -- If the expression is an index of an indexed component, it must
6690 -- be expanded regardless of context.
6692 elsif Nkind
(Parnt
) = N_Indexed_Component
6693 and then Child
/= Prefix
(Parnt
)
6695 Expand_Packed_Element_Reference
(N
);
6698 elsif Nkind
(Parent
(Parnt
)) = N_Assignment_Statement
6699 and then Name
(Parent
(Parnt
)) = Parnt
6703 elsif Nkind
(Parnt
) = N_Attribute_Reference
6704 and then Attribute_Name
(Parnt
) = Name_Read
6705 and then Next
(First
(Expressions
(Parnt
))) = Child
6709 elsif Nkind
(Parnt
) = N_Indexed_Component
6710 and then Prefix
(Parnt
) = Child
6714 elsif Nkind
(Parnt
) = N_Selected_Component
6715 and then Prefix
(Parnt
) = Child
6716 and then not (Present
(Etype
(Selector_Name
(Parnt
)))
6718 Is_Access_Type
(Etype
(Selector_Name
(Parnt
))))
6722 -- If the parent is a dereference, either implicit or explicit,
6723 -- then the packed reference needs to be expanded.
6726 Expand_Packed_Element_Reference
(N
);
6730 -- Keep looking up tree for unchecked expression, or if we are the
6731 -- prefix of a possible assignment left side.
6734 Parnt
:= Parent
(Child
);
6737 end Expand_N_Indexed_Component
;
6739 ---------------------
6740 -- Expand_N_Not_In --
6741 ---------------------
6743 -- Replace a not in b by not (a in b) so that the expansions for (a in b)
6744 -- can be done. This avoids needing to duplicate this expansion code.
6746 procedure Expand_N_Not_In
(N
: Node_Id
) is
6747 Loc
: constant Source_Ptr
:= Sloc
(N
);
6748 Typ
: constant Entity_Id
:= Etype
(N
);
6749 Cfs
: constant Boolean := Comes_From_Source
(N
);
6756 Left_Opnd
=> Left_Opnd
(N
),
6757 Right_Opnd
=> Right_Opnd
(N
))));
6759 -- If this is a set membership, preserve list of alternatives
6761 Set_Alternatives
(Right_Opnd
(N
), Alternatives
(Original_Node
(N
)));
6763 -- We want this to appear as coming from source if original does (see
6764 -- transformations in Expand_N_In).
6766 Set_Comes_From_Source
(N
, Cfs
);
6767 Set_Comes_From_Source
(Right_Opnd
(N
), Cfs
);
6769 -- Now analyze transformed node
6771 Analyze_And_Resolve
(N
, Typ
);
6772 end Expand_N_Not_In
;
6778 -- The only replacement required is for the case of a null of a type that
6779 -- is an access to protected subprogram, or a subtype thereof. We represent
6780 -- such access values as a record, and so we must replace the occurrence of
6781 -- null by the equivalent record (with a null address and a null pointer in
6782 -- it), so that the back end creates the proper value.
6784 procedure Expand_N_Null
(N
: Node_Id
) is
6785 Loc
: constant Source_Ptr
:= Sloc
(N
);
6786 Typ
: constant Entity_Id
:= Base_Type
(Etype
(N
));
6790 if Is_Access_Protected_Subprogram_Type
(Typ
) then
6792 Make_Aggregate
(Loc
,
6793 Expressions
=> New_List
(
6794 New_Occurrence_Of
(RTE
(RE_Null_Address
), Loc
),
6798 Analyze_And_Resolve
(N
, Equivalent_Type
(Typ
));
6800 -- For subsequent semantic analysis, the node must retain its type.
6801 -- Gigi in any case replaces this type by the corresponding record
6802 -- type before processing the node.
6808 when RE_Not_Available
=>
6812 ---------------------
6813 -- Expand_N_Op_Abs --
6814 ---------------------
6816 procedure Expand_N_Op_Abs
(N
: Node_Id
) is
6817 Loc
: constant Source_Ptr
:= Sloc
(N
);
6818 Expr
: constant Node_Id
:= Right_Opnd
(N
);
6821 Unary_Op_Validity_Checks
(N
);
6823 -- Check for MINIMIZED/ELIMINATED overflow mode
6825 if Minimized_Eliminated_Overflow_Check
(N
) then
6826 Apply_Arithmetic_Overflow_Check
(N
);
6830 -- Deal with software overflow checking
6832 if not Backend_Overflow_Checks_On_Target
6833 and then Is_Signed_Integer_Type
(Etype
(N
))
6834 and then Do_Overflow_Check
(N
)
6836 -- The only case to worry about is when the argument is equal to the
6837 -- largest negative number, so what we do is to insert the check:
6839 -- [constraint_error when Expr = typ'Base'First]
6841 -- with the usual Duplicate_Subexpr use coding for expr
6844 Make_Raise_Constraint_Error
(Loc
,
6847 Left_Opnd
=> Duplicate_Subexpr
(Expr
),
6849 Make_Attribute_Reference
(Loc
,
6851 New_Occurrence_Of
(Base_Type
(Etype
(Expr
)), Loc
),
6852 Attribute_Name
=> Name_First
)),
6853 Reason
=> CE_Overflow_Check_Failed
));
6855 end Expand_N_Op_Abs
;
6857 ---------------------
6858 -- Expand_N_Op_Add --
6859 ---------------------
6861 procedure Expand_N_Op_Add
(N
: Node_Id
) is
6862 Typ
: constant Entity_Id
:= Etype
(N
);
6865 Binary_Op_Validity_Checks
(N
);
6867 -- Check for MINIMIZED/ELIMINATED overflow mode
6869 if Minimized_Eliminated_Overflow_Check
(N
) then
6870 Apply_Arithmetic_Overflow_Check
(N
);
6874 -- N + 0 = 0 + N = N for integer types
6876 if Is_Integer_Type
(Typ
) then
6877 if Compile_Time_Known_Value
(Right_Opnd
(N
))
6878 and then Expr_Value
(Right_Opnd
(N
)) = Uint_0
6880 Rewrite
(N
, Left_Opnd
(N
));
6883 elsif Compile_Time_Known_Value
(Left_Opnd
(N
))
6884 and then Expr_Value
(Left_Opnd
(N
)) = Uint_0
6886 Rewrite
(N
, Right_Opnd
(N
));
6891 -- Arithmetic overflow checks for signed integer/fixed point types
6893 if Is_Signed_Integer_Type
(Typ
) or else Is_Fixed_Point_Type
(Typ
) then
6894 Apply_Arithmetic_Overflow_Check
(N
);
6898 -- Overflow checks for floating-point if -gnateF mode active
6900 Check_Float_Op_Overflow
(N
);
6902 -- When generating C code, convert nonbinary modular additions into code
6903 -- that relies on the front-end expansion of operator Mod.
6905 if Modify_Tree_For_C
then
6906 Expand_Nonbinary_Modular_Op
(N
);
6908 end Expand_N_Op_Add
;
6910 ---------------------
6911 -- Expand_N_Op_And --
6912 ---------------------
6914 procedure Expand_N_Op_And
(N
: Node_Id
) is
6915 Typ
: constant Entity_Id
:= Etype
(N
);
6918 Binary_Op_Validity_Checks
(N
);
6920 if Is_Array_Type
(Etype
(N
)) then
6921 Expand_Boolean_Operator
(N
);
6923 elsif Is_Boolean_Type
(Etype
(N
)) then
6924 Adjust_Condition
(Left_Opnd
(N
));
6925 Adjust_Condition
(Right_Opnd
(N
));
6926 Set_Etype
(N
, Standard_Boolean
);
6927 Adjust_Result_Type
(N
, Typ
);
6929 elsif Is_Intrinsic_Subprogram
(Entity
(N
)) then
6930 Expand_Intrinsic_Call
(N
, Entity
(N
));
6933 -- When generating C code, convert nonbinary modular operators into code
6934 -- that relies on the front-end expansion of operator Mod.
6936 if Modify_Tree_For_C
then
6937 Expand_Nonbinary_Modular_Op
(N
);
6939 end Expand_N_Op_And
;
6941 ------------------------
6942 -- Expand_N_Op_Concat --
6943 ------------------------
6945 procedure Expand_N_Op_Concat
(N
: Node_Id
) is
6947 -- List of operands to be concatenated
6950 -- Node which is to be replaced by the result of concatenating the nodes
6951 -- in the list Opnds.
6954 -- Ensure validity of both operands
6956 Binary_Op_Validity_Checks
(N
);
6958 -- If we are the left operand of a concatenation higher up the tree,
6959 -- then do nothing for now, since we want to deal with a series of
6960 -- concatenations as a unit.
6962 if Nkind
(Parent
(N
)) = N_Op_Concat
6963 and then N
= Left_Opnd
(Parent
(N
))
6968 -- We get here with a concatenation whose left operand may be a
6969 -- concatenation itself with a consistent type. We need to process
6970 -- these concatenation operands from left to right, which means
6971 -- from the deepest node in the tree to the highest node.
6974 while Nkind
(Left_Opnd
(Cnode
)) = N_Op_Concat
loop
6975 Cnode
:= Left_Opnd
(Cnode
);
6978 -- Now Cnode is the deepest concatenation, and its parents are the
6979 -- concatenation nodes above, so now we process bottom up, doing the
6982 -- The outer loop runs more than once if more than one concatenation
6983 -- type is involved.
6986 Opnds
:= New_List
(Left_Opnd
(Cnode
), Right_Opnd
(Cnode
));
6987 Set_Parent
(Opnds
, N
);
6989 -- The inner loop gathers concatenation operands
6991 Inner
: while Cnode
/= N
6992 and then Base_Type
(Etype
(Cnode
)) =
6993 Base_Type
(Etype
(Parent
(Cnode
)))
6995 Cnode
:= Parent
(Cnode
);
6996 Append
(Right_Opnd
(Cnode
), Opnds
);
6999 -- Note: The following code is a temporary workaround for N731-034
7000 -- and N829-028 and will be kept until the general issue of internal
7001 -- symbol serialization is addressed. The workaround is kept under a
7002 -- debug switch to avoid permiating into the general case.
7004 -- Wrap the node to concatenate into an expression actions node to
7005 -- keep it nicely packaged. This is useful in the case of an assert
7006 -- pragma with a concatenation where we want to be able to delete
7007 -- the concatenation and all its expansion stuff.
7009 if Debug_Flag_Dot_H
then
7011 Cnod
: constant Node_Id
:= New_Copy_Tree
(Cnode
);
7012 Typ
: constant Entity_Id
:= Base_Type
(Etype
(Cnode
));
7015 -- Note: use Rewrite rather than Replace here, so that for
7016 -- example Why_Not_Static can find the original concatenation
7020 Make_Expression_With_Actions
(Sloc
(Cnode
),
7021 Actions
=> New_List
(Make_Null_Statement
(Sloc
(Cnode
))),
7022 Expression
=> Cnod
));
7024 Expand_Concatenate
(Cnod
, Opnds
);
7025 Analyze_And_Resolve
(Cnode
, Typ
);
7031 Expand_Concatenate
(Cnode
, Opnds
);
7034 exit Outer
when Cnode
= N
;
7035 Cnode
:= Parent
(Cnode
);
7037 end Expand_N_Op_Concat
;
7039 ------------------------
7040 -- Expand_N_Op_Divide --
7041 ------------------------
7043 procedure Expand_N_Op_Divide
(N
: Node_Id
) is
7044 Loc
: constant Source_Ptr
:= Sloc
(N
);
7045 Lopnd
: constant Node_Id
:= Left_Opnd
(N
);
7046 Ropnd
: constant Node_Id
:= Right_Opnd
(N
);
7047 Ltyp
: constant Entity_Id
:= Etype
(Lopnd
);
7048 Rtyp
: constant Entity_Id
:= Etype
(Ropnd
);
7049 Typ
: Entity_Id
:= Etype
(N
);
7050 Rknow
: constant Boolean := Is_Integer_Type
(Typ
)
7052 Compile_Time_Known_Value
(Ropnd
);
7056 Binary_Op_Validity_Checks
(N
);
7058 -- Check for MINIMIZED/ELIMINATED overflow mode
7060 if Minimized_Eliminated_Overflow_Check
(N
) then
7061 Apply_Arithmetic_Overflow_Check
(N
);
7065 -- Otherwise proceed with expansion of division
7068 Rval
:= Expr_Value
(Ropnd
);
7071 -- N / 1 = N for integer types
7073 if Rknow
and then Rval
= Uint_1
then
7078 -- Convert x / 2 ** y to Shift_Right (x, y). Note that the fact that
7079 -- Is_Power_Of_2_For_Shift is set means that we know that our left
7080 -- operand is an unsigned integer, as required for this to work.
7082 if Nkind
(Ropnd
) = N_Op_Expon
7083 and then Is_Power_Of_2_For_Shift
(Ropnd
)
7085 -- We cannot do this transformation in configurable run time mode if we
7086 -- have 64-bit integers and long shifts are not available.
7088 and then (Esize
(Ltyp
) <= 32 or else Support_Long_Shifts_On_Target
)
7091 Make_Op_Shift_Right
(Loc
,
7094 Convert_To
(Standard_Natural
, Right_Opnd
(Ropnd
))));
7095 Analyze_And_Resolve
(N
, Typ
);
7099 -- Do required fixup of universal fixed operation
7101 if Typ
= Universal_Fixed
then
7102 Fixup_Universal_Fixed_Operation
(N
);
7106 -- Divisions with fixed-point results
7108 if Is_Fixed_Point_Type
(Typ
) then
7110 -- No special processing if Treat_Fixed_As_Integer is set, since
7111 -- from a semantic point of view such operations are simply integer
7112 -- operations and will be treated that way.
7114 if not Treat_Fixed_As_Integer
(N
) then
7115 if Is_Integer_Type
(Rtyp
) then
7116 Expand_Divide_Fixed_By_Integer_Giving_Fixed
(N
);
7118 Expand_Divide_Fixed_By_Fixed_Giving_Fixed
(N
);
7122 -- Deal with divide-by-zero check if back end cannot handle them
7123 -- and the flag is set indicating that we need such a check. Note
7124 -- that we don't need to bother here with the case of mixed-mode
7125 -- (Right operand an integer type), since these will be rewritten
7126 -- with conversions to a divide with a fixed-point right operand.
7128 if Nkind
(N
) = N_Op_Divide
7129 and then Do_Division_Check
(N
)
7130 and then not Backend_Divide_Checks_On_Target
7131 and then not Is_Integer_Type
(Rtyp
)
7133 Set_Do_Division_Check
(N
, False);
7135 Make_Raise_Constraint_Error
(Loc
,
7138 Left_Opnd
=> Duplicate_Subexpr_Move_Checks
(Ropnd
),
7139 Right_Opnd
=> Make_Real_Literal
(Loc
, Ureal_0
)),
7140 Reason
=> CE_Divide_By_Zero
));
7143 -- Other cases of division of fixed-point operands. Again we exclude the
7144 -- case where Treat_Fixed_As_Integer is set.
7146 elsif (Is_Fixed_Point_Type
(Ltyp
) or else Is_Fixed_Point_Type
(Rtyp
))
7147 and then not Treat_Fixed_As_Integer
(N
)
7149 if Is_Integer_Type
(Typ
) then
7150 Expand_Divide_Fixed_By_Fixed_Giving_Integer
(N
);
7152 pragma Assert
(Is_Floating_Point_Type
(Typ
));
7153 Expand_Divide_Fixed_By_Fixed_Giving_Float
(N
);
7156 -- Mixed-mode operations can appear in a non-static universal context,
7157 -- in which case the integer argument must be converted explicitly.
7159 elsif Typ
= Universal_Real
and then Is_Integer_Type
(Rtyp
) then
7161 Convert_To
(Universal_Real
, Relocate_Node
(Ropnd
)));
7163 Analyze_And_Resolve
(Ropnd
, Universal_Real
);
7165 elsif Typ
= Universal_Real
and then Is_Integer_Type
(Ltyp
) then
7167 Convert_To
(Universal_Real
, Relocate_Node
(Lopnd
)));
7169 Analyze_And_Resolve
(Lopnd
, Universal_Real
);
7171 -- Non-fixed point cases, do integer zero divide and overflow checks
7173 elsif Is_Integer_Type
(Typ
) then
7174 Apply_Divide_Checks
(N
);
7177 -- Overflow checks for floating-point if -gnateF mode active
7179 Check_Float_Op_Overflow
(N
);
7181 -- When generating C code, convert nonbinary modular divisions into code
7182 -- that relies on the front-end expansion of operator Mod.
7184 if Modify_Tree_For_C
then
7185 Expand_Nonbinary_Modular_Op
(N
);
7187 end Expand_N_Op_Divide
;
7189 --------------------
7190 -- Expand_N_Op_Eq --
7191 --------------------
7193 procedure Expand_N_Op_Eq
(N
: Node_Id
) is
7194 Loc
: constant Source_Ptr
:= Sloc
(N
);
7195 Typ
: constant Entity_Id
:= Etype
(N
);
7196 Lhs
: constant Node_Id
:= Left_Opnd
(N
);
7197 Rhs
: constant Node_Id
:= Right_Opnd
(N
);
7198 Bodies
: constant List_Id
:= New_List
;
7199 A_Typ
: constant Entity_Id
:= Etype
(Lhs
);
7201 Typl
: Entity_Id
:= A_Typ
;
7202 Op_Name
: Entity_Id
;
7205 procedure Build_Equality_Call
(Eq
: Entity_Id
);
7206 -- If a constructed equality exists for the type or for its parent,
7207 -- build and analyze call, adding conversions if the operation is
7210 function Has_Unconstrained_UU_Component
(Typ
: Node_Id
) return Boolean;
7211 -- Determines whether a type has a subcomponent of an unconstrained
7212 -- Unchecked_Union subtype. Typ is a record type.
7214 -------------------------
7215 -- Build_Equality_Call --
7216 -------------------------
7218 procedure Build_Equality_Call
(Eq
: Entity_Id
) is
7219 Op_Type
: constant Entity_Id
:= Etype
(First_Formal
(Eq
));
7220 L_Exp
: Node_Id
:= Relocate_Node
(Lhs
);
7221 R_Exp
: Node_Id
:= Relocate_Node
(Rhs
);
7224 -- Adjust operands if necessary to comparison type
7226 if Base_Type
(Op_Type
) /= Base_Type
(A_Typ
)
7227 and then not Is_Class_Wide_Type
(A_Typ
)
7229 L_Exp
:= OK_Convert_To
(Op_Type
, L_Exp
);
7230 R_Exp
:= OK_Convert_To
(Op_Type
, R_Exp
);
7233 -- If we have an Unchecked_Union, we need to add the inferred
7234 -- discriminant values as actuals in the function call. At this
7235 -- point, the expansion has determined that both operands have
7236 -- inferable discriminants.
7238 if Is_Unchecked_Union
(Op_Type
) then
7240 Lhs_Type
: constant Node_Id
:= Etype
(L_Exp
);
7241 Rhs_Type
: constant Node_Id
:= Etype
(R_Exp
);
7243 Lhs_Discr_Vals
: Elist_Id
;
7244 -- List of inferred discriminant values for left operand.
7246 Rhs_Discr_Vals
: Elist_Id
;
7247 -- List of inferred discriminant values for right operand.
7252 Lhs_Discr_Vals
:= New_Elmt_List
;
7253 Rhs_Discr_Vals
:= New_Elmt_List
;
7255 -- Per-object constrained selected components require special
7256 -- attention. If the enclosing scope of the component is an
7257 -- Unchecked_Union, we cannot reference its discriminants
7258 -- directly. This is why we use the extra parameters of the
7259 -- equality function of the enclosing Unchecked_Union.
7261 -- type UU_Type (Discr : Integer := 0) is
7264 -- pragma Unchecked_Union (UU_Type);
7266 -- 1. Unchecked_Union enclosing record:
7268 -- type Enclosing_UU_Type (Discr : Integer := 0) is record
7270 -- Comp : UU_Type (Discr);
7272 -- end Enclosing_UU_Type;
7273 -- pragma Unchecked_Union (Enclosing_UU_Type);
7275 -- Obj1 : Enclosing_UU_Type;
7276 -- Obj2 : Enclosing_UU_Type (1);
7278 -- [. . .] Obj1 = Obj2 [. . .]
7282 -- if not (uu_typeEQ (obj1.comp, obj2.comp, a, b)) then
7284 -- A and B are the formal parameters of the equality function
7285 -- of Enclosing_UU_Type. The function always has two extra
7286 -- formals to capture the inferred discriminant values for
7287 -- each discriminant of the type.
7289 -- 2. Non-Unchecked_Union enclosing record:
7292 -- Enclosing_Non_UU_Type (Discr : Integer := 0)
7295 -- Comp : UU_Type (Discr);
7297 -- end Enclosing_Non_UU_Type;
7299 -- Obj1 : Enclosing_Non_UU_Type;
7300 -- Obj2 : Enclosing_Non_UU_Type (1);
7302 -- ... Obj1 = Obj2 ...
7306 -- if not (uu_typeEQ (obj1.comp, obj2.comp,
7307 -- obj1.discr, obj2.discr)) then
7309 -- In this case we can directly reference the discriminants of
7310 -- the enclosing record.
7312 -- Process left operand of equality
7314 if Nkind
(Lhs
) = N_Selected_Component
7316 Has_Per_Object_Constraint
(Entity
(Selector_Name
(Lhs
)))
7318 -- If enclosing record is an Unchecked_Union, use formals
7319 -- corresponding to each discriminant. The name of the
7320 -- formal is that of the discriminant, with added suffix,
7321 -- see Exp_Ch3.Build_Record_Equality for details.
7323 if Is_Unchecked_Union
(Scope
(Entity
(Selector_Name
(Lhs
))))
7327 (Scope
(Entity
(Selector_Name
(Lhs
))));
7328 while Present
(Discr
) loop
7330 (Make_Identifier
(Loc
,
7331 Chars
=> New_External_Name
(Chars
(Discr
), 'A')),
7332 To
=> Lhs_Discr_Vals
);
7333 Next_Discriminant
(Discr
);
7336 -- If enclosing record is of a non-Unchecked_Union type, it
7337 -- is possible to reference its discriminants directly.
7340 Discr
:= First_Discriminant
(Lhs_Type
);
7341 while Present
(Discr
) loop
7343 (Make_Selected_Component
(Loc
,
7344 Prefix
=> Prefix
(Lhs
),
7347 (Get_Discriminant_Value
(Discr
,
7349 Stored_Constraint
(Lhs_Type
)))),
7350 To
=> Lhs_Discr_Vals
);
7351 Next_Discriminant
(Discr
);
7355 -- Otherwise operand is on object with a constrained type.
7356 -- Infer the discriminant values from the constraint.
7360 Discr
:= First_Discriminant
(Lhs_Type
);
7361 while Present
(Discr
) loop
7364 (Get_Discriminant_Value
(Discr
,
7366 Stored_Constraint
(Lhs_Type
))),
7367 To
=> Lhs_Discr_Vals
);
7368 Next_Discriminant
(Discr
);
7372 -- Similar processing for right operand of equality
7374 if Nkind
(Rhs
) = N_Selected_Component
7376 Has_Per_Object_Constraint
(Entity
(Selector_Name
(Rhs
)))
7378 if Is_Unchecked_Union
7379 (Scope
(Entity
(Selector_Name
(Rhs
))))
7383 (Scope
(Entity
(Selector_Name
(Rhs
))));
7384 while Present
(Discr
) loop
7386 (Make_Identifier
(Loc
,
7387 Chars
=> New_External_Name
(Chars
(Discr
), 'B')),
7388 To
=> Rhs_Discr_Vals
);
7389 Next_Discriminant
(Discr
);
7393 Discr
:= First_Discriminant
(Rhs_Type
);
7394 while Present
(Discr
) loop
7396 (Make_Selected_Component
(Loc
,
7397 Prefix
=> Prefix
(Rhs
),
7399 New_Copy
(Get_Discriminant_Value
7402 Stored_Constraint
(Rhs_Type
)))),
7403 To
=> Rhs_Discr_Vals
);
7404 Next_Discriminant
(Discr
);
7409 Discr
:= First_Discriminant
(Rhs_Type
);
7410 while Present
(Discr
) loop
7412 (New_Copy
(Get_Discriminant_Value
7415 Stored_Constraint
(Rhs_Type
))),
7416 To
=> Rhs_Discr_Vals
);
7417 Next_Discriminant
(Discr
);
7421 -- Now merge the list of discriminant values so that values
7422 -- of corresponding discriminants are adjacent.
7430 Params
:= New_List
(L_Exp
, R_Exp
);
7431 L_Elmt
:= First_Elmt
(Lhs_Discr_Vals
);
7432 R_Elmt
:= First_Elmt
(Rhs_Discr_Vals
);
7433 while Present
(L_Elmt
) loop
7434 Append_To
(Params
, Node
(L_Elmt
));
7435 Append_To
(Params
, Node
(R_Elmt
));
7441 Make_Function_Call
(Loc
,
7442 Name
=> New_Occurrence_Of
(Eq
, Loc
),
7443 Parameter_Associations
=> Params
));
7447 -- Normal case, not an unchecked union
7451 Make_Function_Call
(Loc
,
7452 Name
=> New_Occurrence_Of
(Eq
, Loc
),
7453 Parameter_Associations
=> New_List
(L_Exp
, R_Exp
)));
7456 Analyze_And_Resolve
(N
, Standard_Boolean
, Suppress
=> All_Checks
);
7457 end Build_Equality_Call
;
7459 ------------------------------------
7460 -- Has_Unconstrained_UU_Component --
7461 ------------------------------------
7463 function Has_Unconstrained_UU_Component
7464 (Typ
: Node_Id
) return Boolean
7466 Tdef
: constant Node_Id
:=
7467 Type_Definition
(Declaration_Node
(Base_Type
(Typ
)));
7471 function Component_Is_Unconstrained_UU
7472 (Comp
: Node_Id
) return Boolean;
7473 -- Determines whether the subtype of the component is an
7474 -- unconstrained Unchecked_Union.
7476 function Variant_Is_Unconstrained_UU
7477 (Variant
: Node_Id
) return Boolean;
7478 -- Determines whether a component of the variant has an unconstrained
7479 -- Unchecked_Union subtype.
7481 -----------------------------------
7482 -- Component_Is_Unconstrained_UU --
7483 -----------------------------------
7485 function Component_Is_Unconstrained_UU
7486 (Comp
: Node_Id
) return Boolean
7489 if Nkind
(Comp
) /= N_Component_Declaration
then
7494 Sindic
: constant Node_Id
:=
7495 Subtype_Indication
(Component_Definition
(Comp
));
7498 -- Unconstrained nominal type. In the case of a constraint
7499 -- present, the node kind would have been N_Subtype_Indication.
7501 if Nkind
(Sindic
) = N_Identifier
then
7502 return Is_Unchecked_Union
(Base_Type
(Etype
(Sindic
)));
7507 end Component_Is_Unconstrained_UU
;
7509 ---------------------------------
7510 -- Variant_Is_Unconstrained_UU --
7511 ---------------------------------
7513 function Variant_Is_Unconstrained_UU
7514 (Variant
: Node_Id
) return Boolean
7516 Clist
: constant Node_Id
:= Component_List
(Variant
);
7519 if Is_Empty_List
(Component_Items
(Clist
)) then
7523 -- We only need to test one component
7526 Comp
: Node_Id
:= First
(Component_Items
(Clist
));
7529 while Present
(Comp
) loop
7530 if Component_Is_Unconstrained_UU
(Comp
) then
7538 -- None of the components withing the variant were of
7539 -- unconstrained Unchecked_Union type.
7542 end Variant_Is_Unconstrained_UU
;
7544 -- Start of processing for Has_Unconstrained_UU_Component
7547 if Null_Present
(Tdef
) then
7551 Clist
:= Component_List
(Tdef
);
7552 Vpart
:= Variant_Part
(Clist
);
7554 -- Inspect available components
7556 if Present
(Component_Items
(Clist
)) then
7558 Comp
: Node_Id
:= First
(Component_Items
(Clist
));
7561 while Present
(Comp
) loop
7563 -- One component is sufficient
7565 if Component_Is_Unconstrained_UU
(Comp
) then
7574 -- Inspect available components withing variants
7576 if Present
(Vpart
) then
7578 Variant
: Node_Id
:= First
(Variants
(Vpart
));
7581 while Present
(Variant
) loop
7583 -- One component within a variant is sufficient
7585 if Variant_Is_Unconstrained_UU
(Variant
) then
7594 -- Neither the available components, nor the components inside the
7595 -- variant parts were of an unconstrained Unchecked_Union subtype.
7598 end Has_Unconstrained_UU_Component
;
7600 -- Start of processing for Expand_N_Op_Eq
7603 Binary_Op_Validity_Checks
(N
);
7605 -- Deal with private types
7607 if Ekind
(Typl
) = E_Private_Type
then
7608 Typl
:= Underlying_Type
(Typl
);
7609 elsif Ekind
(Typl
) = E_Private_Subtype
then
7610 Typl
:= Underlying_Type
(Base_Type
(Typl
));
7615 -- It may happen in error situations that the underlying type is not
7616 -- set. The error will be detected later, here we just defend the
7623 -- Now get the implementation base type (note that plain Base_Type here
7624 -- might lead us back to the private type, which is not what we want!)
7626 Typl
:= Implementation_Base_Type
(Typl
);
7628 -- Equality between variant records results in a call to a routine
7629 -- that has conditional tests of the discriminant value(s), and hence
7630 -- violates the No_Implicit_Conditionals restriction.
7632 if Has_Variant_Part
(Typl
) then
7637 Check_Restriction
(Msg
, No_Implicit_Conditionals
, N
);
7641 ("\comparison of variant records tests discriminants", N
);
7647 -- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
7648 -- means we no longer have a comparison operation, we are all done.
7650 Expand_Compare_Minimize_Eliminate_Overflow
(N
);
7652 if Nkind
(N
) /= N_Op_Eq
then
7656 -- Boolean types (requiring handling of non-standard case)
7658 if Is_Boolean_Type
(Typl
) then
7659 Adjust_Condition
(Left_Opnd
(N
));
7660 Adjust_Condition
(Right_Opnd
(N
));
7661 Set_Etype
(N
, Standard_Boolean
);
7662 Adjust_Result_Type
(N
, Typ
);
7666 elsif Is_Array_Type
(Typl
) then
7668 -- If we are doing full validity checking, and it is possible for the
7669 -- array elements to be invalid then expand out array comparisons to
7670 -- make sure that we check the array elements.
7672 if Validity_Check_Operands
7673 and then not Is_Known_Valid
(Component_Type
(Typl
))
7676 Save_Force_Validity_Checks
: constant Boolean :=
7677 Force_Validity_Checks
;
7679 Force_Validity_Checks
:= True;
7681 Expand_Array_Equality
7683 Relocate_Node
(Lhs
),
7684 Relocate_Node
(Rhs
),
7687 Insert_Actions
(N
, Bodies
);
7688 Analyze_And_Resolve
(N
, Standard_Boolean
);
7689 Force_Validity_Checks
:= Save_Force_Validity_Checks
;
7692 -- Packed case where both operands are known aligned
7694 elsif Is_Bit_Packed_Array
(Typl
)
7695 and then not Is_Possibly_Unaligned_Object
(Lhs
)
7696 and then not Is_Possibly_Unaligned_Object
(Rhs
)
7698 Expand_Packed_Eq
(N
);
7700 -- Where the component type is elementary we can use a block bit
7701 -- comparison (if supported on the target) exception in the case
7702 -- of floating-point (negative zero issues require element by
7703 -- element comparison), and atomic/VFA types (where we must be sure
7704 -- to load elements independently) and possibly unaligned arrays.
7706 elsif Is_Elementary_Type
(Component_Type
(Typl
))
7707 and then not Is_Floating_Point_Type
(Component_Type
(Typl
))
7708 and then not Is_Atomic_Or_VFA
(Component_Type
(Typl
))
7709 and then not Is_Possibly_Unaligned_Object
(Lhs
)
7710 and then not Is_Possibly_Unaligned_Object
(Rhs
)
7711 and then Support_Composite_Compare_On_Target
7715 -- For composite and floating-point cases, expand equality loop to
7716 -- make sure of using proper comparisons for tagged types, and
7717 -- correctly handling the floating-point case.
7721 Expand_Array_Equality
7723 Relocate_Node
(Lhs
),
7724 Relocate_Node
(Rhs
),
7727 Insert_Actions
(N
, Bodies
, Suppress
=> All_Checks
);
7728 Analyze_And_Resolve
(N
, Standard_Boolean
, Suppress
=> All_Checks
);
7733 elsif Is_Record_Type
(Typl
) then
7735 -- For tagged types, use the primitive "="
7737 if Is_Tagged_Type
(Typl
) then
7739 -- No need to do anything else compiling under restriction
7740 -- No_Dispatching_Calls. During the semantic analysis we
7741 -- already notified such violation.
7743 if Restriction_Active
(No_Dispatching_Calls
) then
7747 -- If this is derived from an untagged private type completed with
7748 -- a tagged type, it does not have a full view, so we use the
7749 -- primitive operations of the private type. This check should no
7750 -- longer be necessary when these types get their full views???
7752 if Is_Private_Type
(A_Typ
)
7753 and then not Is_Tagged_Type
(A_Typ
)
7754 and then Is_Derived_Type
(A_Typ
)
7755 and then No
(Full_View
(A_Typ
))
7757 -- Search for equality operation, checking that the operands
7758 -- have the same type. Note that we must find a matching entry,
7759 -- or something is very wrong.
7761 Prim
:= First_Elmt
(Collect_Primitive_Operations
(A_Typ
));
7763 while Present
(Prim
) loop
7764 exit when Chars
(Node
(Prim
)) = Name_Op_Eq
7765 and then Etype
(First_Formal
(Node
(Prim
))) =
7766 Etype
(Next_Formal
(First_Formal
(Node
(Prim
))))
7768 Base_Type
(Etype
(Node
(Prim
))) = Standard_Boolean
;
7773 pragma Assert
(Present
(Prim
));
7774 Op_Name
:= Node
(Prim
);
7776 -- Find the type's predefined equality or an overriding
7777 -- user-defined equality. The reason for not simply calling
7778 -- Find_Prim_Op here is that there may be a user-defined
7779 -- overloaded equality op that precedes the equality that we
7780 -- want, so we have to explicitly search (e.g., there could be
7781 -- an equality with two different parameter types).
7784 if Is_Class_Wide_Type
(Typl
) then
7785 Typl
:= Find_Specific_Type
(Typl
);
7788 Prim
:= First_Elmt
(Primitive_Operations
(Typl
));
7789 while Present
(Prim
) loop
7790 exit when Chars
(Node
(Prim
)) = Name_Op_Eq
7791 and then Etype
(First_Formal
(Node
(Prim
))) =
7792 Etype
(Next_Formal
(First_Formal
(Node
(Prim
))))
7794 Base_Type
(Etype
(Node
(Prim
))) = Standard_Boolean
;
7799 pragma Assert
(Present
(Prim
));
7800 Op_Name
:= Node
(Prim
);
7803 Build_Equality_Call
(Op_Name
);
7805 -- Ada 2005 (AI-216): Program_Error is raised when evaluating the
7806 -- predefined equality operator for a type which has a subcomponent
7807 -- of an Unchecked_Union type whose nominal subtype is unconstrained.
7809 elsif Has_Unconstrained_UU_Component
(Typl
) then
7811 Make_Raise_Program_Error
(Loc
,
7812 Reason
=> PE_Unchecked_Union_Restriction
));
7814 -- Prevent Gigi from generating incorrect code by rewriting the
7815 -- equality as a standard False. (is this documented somewhere???)
7818 New_Occurrence_Of
(Standard_False
, Loc
));
7820 elsif Is_Unchecked_Union
(Typl
) then
7822 -- If we can infer the discriminants of the operands, we make a
7823 -- call to the TSS equality function.
7825 if Has_Inferable_Discriminants
(Lhs
)
7827 Has_Inferable_Discriminants
(Rhs
)
7830 (TSS
(Root_Type
(Typl
), TSS_Composite_Equality
));
7833 -- Ada 2005 (AI-216): Program_Error is raised when evaluating
7834 -- the predefined equality operator for an Unchecked_Union type
7835 -- if either of the operands lack inferable discriminants.
7838 Make_Raise_Program_Error
(Loc
,
7839 Reason
=> PE_Unchecked_Union_Restriction
));
7841 -- Emit a warning on source equalities only, otherwise the
7842 -- message may appear out of place due to internal use. The
7843 -- warning is unconditional because it is required by the
7846 if Comes_From_Source
(N
) then
7848 ("Unchecked_Union discriminants cannot be determined??",
7851 ("\Program_Error will be raised for equality operation??",
7855 -- Prevent Gigi from generating incorrect code by rewriting
7856 -- the equality as a standard False (documented where???).
7859 New_Occurrence_Of
(Standard_False
, Loc
));
7862 -- If a type support function is present (for complex cases), use it
7864 elsif Present
(TSS
(Root_Type
(Typl
), TSS_Composite_Equality
)) then
7866 (TSS
(Root_Type
(Typl
), TSS_Composite_Equality
));
7868 -- When comparing two Bounded_Strings, use the primitive equality of
7869 -- the root Super_String type.
7871 elsif Is_Bounded_String
(Typl
) then
7873 First_Elmt
(Collect_Primitive_Operations
(Root_Type
(Typl
)));
7875 while Present
(Prim
) loop
7876 exit when Chars
(Node
(Prim
)) = Name_Op_Eq
7877 and then Etype
(First_Formal
(Node
(Prim
))) =
7878 Etype
(Next_Formal
(First_Formal
(Node
(Prim
))))
7879 and then Base_Type
(Etype
(Node
(Prim
))) = Standard_Boolean
;
7884 -- A Super_String type should always have a primitive equality
7886 pragma Assert
(Present
(Prim
));
7887 Build_Equality_Call
(Node
(Prim
));
7889 -- Otherwise expand the component by component equality. Note that
7890 -- we never use block-bit comparisons for records, because of the
7891 -- problems with gaps. The back end will often be able to recombine
7892 -- the separate comparisons that we generate here.
7895 Remove_Side_Effects
(Lhs
);
7896 Remove_Side_Effects
(Rhs
);
7898 Expand_Record_Equality
(N
, Typl
, Lhs
, Rhs
, Bodies
));
7900 Insert_Actions
(N
, Bodies
, Suppress
=> All_Checks
);
7901 Analyze_And_Resolve
(N
, Standard_Boolean
, Suppress
=> All_Checks
);
7905 -- Test if result is known at compile time
7907 Rewrite_Comparison
(N
);
7909 -- Special optimization of length comparison
7911 Optimize_Length_Comparison
(N
);
7913 -- One more special case: if we have a comparison of X'Result = expr
7914 -- in floating-point, then if not already there, change expr to be
7915 -- f'Machine (expr) to eliminate surprise from extra precision.
7917 if Is_Floating_Point_Type
(Typl
)
7918 and then Nkind
(Original_Node
(Lhs
)) = N_Attribute_Reference
7919 and then Attribute_Name
(Original_Node
(Lhs
)) = Name_Result
7921 -- Stick in the Typ'Machine call if not already there
7923 if Nkind
(Rhs
) /= N_Attribute_Reference
7924 or else Attribute_Name
(Rhs
) /= Name_Machine
7927 Make_Attribute_Reference
(Loc
,
7928 Prefix
=> New_Occurrence_Of
(Typl
, Loc
),
7929 Attribute_Name
=> Name_Machine
,
7930 Expressions
=> New_List
(Relocate_Node
(Rhs
))));
7931 Analyze_And_Resolve
(Rhs
, Typl
);
7936 -----------------------
7937 -- Expand_N_Op_Expon --
7938 -----------------------
7940 procedure Expand_N_Op_Expon
(N
: Node_Id
) is
7941 Loc
: constant Source_Ptr
:= Sloc
(N
);
7942 Ovflo
: constant Boolean := Do_Overflow_Check
(N
);
7943 Typ
: constant Entity_Id
:= Etype
(N
);
7944 Rtyp
: constant Entity_Id
:= Root_Type
(Typ
);
7948 function Wrap_MA
(Exp
: Node_Id
) return Node_Id
;
7949 -- Given an expression Exp, if the root type is Float or Long_Float,
7950 -- then wrap the expression in a call of Bastyp'Machine, to stop any
7951 -- extra precision. This is done to ensure that X**A = X**B when A is
7952 -- a static constant and B is a variable with the same value. For any
7953 -- other type, the node Exp is returned unchanged.
7959 function Wrap_MA
(Exp
: Node_Id
) return Node_Id
is
7960 Loc
: constant Source_Ptr
:= Sloc
(Exp
);
7963 if Rtyp
= Standard_Float
or else Rtyp
= Standard_Long_Float
then
7965 Make_Attribute_Reference
(Loc
,
7966 Attribute_Name
=> Name_Machine
,
7967 Prefix
=> New_Occurrence_Of
(Bastyp
, Loc
),
7968 Expressions
=> New_List
(Relocate_Node
(Exp
)));
7986 -- Start of processing for Expand_N_Op_Expon
7989 Binary_Op_Validity_Checks
(N
);
7991 -- CodePeer wants to see the unexpanded N_Op_Expon node
7993 if CodePeer_Mode
then
7997 -- Relocation of left and right operands must be done after performing
7998 -- the validity checks since the generation of validation checks may
7999 -- remove side effects.
8001 Base
:= Relocate_Node
(Left_Opnd
(N
));
8002 Bastyp
:= Etype
(Base
);
8003 Exp
:= Relocate_Node
(Right_Opnd
(N
));
8004 Exptyp
:= Etype
(Exp
);
8006 -- If either operand is of a private type, then we have the use of an
8007 -- intrinsic operator, and we get rid of the privateness, by using root
8008 -- types of underlying types for the actual operation. Otherwise the
8009 -- private types will cause trouble if we expand multiplications or
8010 -- shifts etc. We also do this transformation if the result type is
8011 -- different from the base type.
8013 if Is_Private_Type
(Etype
(Base
))
8014 or else Is_Private_Type
(Typ
)
8015 or else Is_Private_Type
(Exptyp
)
8016 or else Rtyp
/= Root_Type
(Bastyp
)
8019 Bt
: constant Entity_Id
:= Root_Type
(Underlying_Type
(Bastyp
));
8020 Et
: constant Entity_Id
:= Root_Type
(Underlying_Type
(Exptyp
));
8023 Unchecked_Convert_To
(Typ
,
8025 Left_Opnd
=> Unchecked_Convert_To
(Bt
, Base
),
8026 Right_Opnd
=> Unchecked_Convert_To
(Et
, Exp
))));
8027 Analyze_And_Resolve
(N
, Typ
);
8032 -- Check for MINIMIZED/ELIMINATED overflow mode
8034 if Minimized_Eliminated_Overflow_Check
(N
) then
8035 Apply_Arithmetic_Overflow_Check
(N
);
8039 -- Test for case of known right argument where we can replace the
8040 -- exponentiation by an equivalent expression using multiplication.
8042 -- Note: use CRT_Safe version of Compile_Time_Known_Value because in
8043 -- configurable run-time mode, we may not have the exponentiation
8044 -- routine available, and we don't want the legality of the program
8045 -- to depend on how clever the compiler is in knowing values.
8047 if CRT_Safe_Compile_Time_Known_Value
(Exp
) then
8048 Expv
:= Expr_Value
(Exp
);
8050 -- We only fold small non-negative exponents. You might think we
8051 -- could fold small negative exponents for the real case, but we
8052 -- can't because we are required to raise Constraint_Error for
8053 -- the case of 0.0 ** (negative) even if Machine_Overflows = False.
8054 -- See ACVC test C4A012B, and it is not worth generating the test.
8056 -- For small negative exponents, we return the reciprocal of
8057 -- the folding of the exponentiation for the opposite (positive)
8058 -- exponent, as required by Ada RM 4.5.6(11/3).
8060 if abs Expv
<= 4 then
8062 -- X ** 0 = 1 (or 1.0)
8066 -- Call Remove_Side_Effects to ensure that any side effects
8067 -- in the ignored left operand (in particular function calls
8068 -- to user defined functions) are properly executed.
8070 Remove_Side_Effects
(Base
);
8072 if Ekind
(Typ
) in Integer_Kind
then
8073 Xnode
:= Make_Integer_Literal
(Loc
, Intval
=> 1);
8075 Xnode
:= Make_Real_Literal
(Loc
, Ureal_1
);
8088 Make_Op_Multiply
(Loc
,
8089 Left_Opnd
=> Duplicate_Subexpr
(Base
),
8090 Right_Opnd
=> Duplicate_Subexpr_No_Checks
(Base
)));
8092 -- X ** 3 = X * X * X
8097 Make_Op_Multiply
(Loc
,
8099 Make_Op_Multiply
(Loc
,
8100 Left_Opnd
=> Duplicate_Subexpr
(Base
),
8101 Right_Opnd
=> Duplicate_Subexpr_No_Checks
(Base
)),
8102 Right_Opnd
=> Duplicate_Subexpr_No_Checks
(Base
)));
8107 -- En : constant base'type := base * base;
8112 Temp
:= Make_Temporary
(Loc
, 'E', Base
);
8115 Make_Expression_With_Actions
(Loc
,
8116 Actions
=> New_List
(
8117 Make_Object_Declaration
(Loc
,
8118 Defining_Identifier
=> Temp
,
8119 Constant_Present
=> True,
8120 Object_Definition
=> New_Occurrence_Of
(Typ
, Loc
),
8123 Make_Op_Multiply
(Loc
,
8125 Duplicate_Subexpr
(Base
),
8127 Duplicate_Subexpr_No_Checks
(Base
))))),
8131 Make_Op_Multiply
(Loc
,
8132 Left_Opnd
=> New_Occurrence_Of
(Temp
, Loc
),
8133 Right_Opnd
=> New_Occurrence_Of
(Temp
, Loc
))));
8135 -- X ** N = 1.0 / X ** (-N)
8140 (Expv
= -1 or Expv
= -2 or Expv
= -3 or Expv
= -4);
8143 Make_Op_Divide
(Loc
,
8145 Make_Float_Literal
(Loc
,
8147 Significand
=> Uint_1
,
8148 Exponent
=> Uint_0
),
8151 Left_Opnd
=> Duplicate_Subexpr
(Base
),
8153 Make_Integer_Literal
(Loc
,
8158 Analyze_And_Resolve
(N
, Typ
);
8163 -- Deal with optimizing 2 ** expression to shift where possible
8165 -- Note: we used to check that Exptyp was an unsigned type. But that is
8166 -- an unnecessary check, since if Exp is negative, we have a run-time
8167 -- error that is either caught (so we get the right result) or we have
8168 -- suppressed the check, in which case the code is erroneous anyway.
8170 if Is_Integer_Type
(Rtyp
)
8172 -- The base value must be "safe compile-time known", and exactly 2
8174 and then Nkind
(Base
) = N_Integer_Literal
8175 and then CRT_Safe_Compile_Time_Known_Value
(Base
)
8176 and then Expr_Value
(Base
) = Uint_2
8178 -- We only handle cases where the right type is a integer
8180 and then Is_Integer_Type
(Root_Type
(Exptyp
))
8181 and then Esize
(Root_Type
(Exptyp
)) <= Esize
(Standard_Integer
)
8183 -- This transformation is not applicable for a modular type with a
8184 -- nonbinary modulus because we do not handle modular reduction in
8185 -- a correct manner if we attempt this transformation in this case.
8187 and then not Non_Binary_Modulus
(Typ
)
8189 -- Handle the cases where our parent is a division or multiplication
8190 -- specially. In these cases we can convert to using a shift at the
8191 -- parent level if we are not doing overflow checking, since it is
8192 -- too tricky to combine the overflow check at the parent level.
8195 and then Nkind_In
(Parent
(N
), N_Op_Divide
, N_Op_Multiply
)
8198 P
: constant Node_Id
:= Parent
(N
);
8199 L
: constant Node_Id
:= Left_Opnd
(P
);
8200 R
: constant Node_Id
:= Right_Opnd
(P
);
8203 if (Nkind
(P
) = N_Op_Multiply
8205 ((Is_Integer_Type
(Etype
(L
)) and then R
= N
)
8207 (Is_Integer_Type
(Etype
(R
)) and then L
= N
))
8208 and then not Do_Overflow_Check
(P
))
8211 (Nkind
(P
) = N_Op_Divide
8212 and then Is_Integer_Type
(Etype
(L
))
8213 and then Is_Unsigned_Type
(Etype
(L
))
8215 and then not Do_Overflow_Check
(P
))
8217 Set_Is_Power_Of_2_For_Shift
(N
);
8222 -- Here we just have 2 ** N on its own, so we can convert this to a
8223 -- shift node. We are prepared to deal with overflow here, and we
8224 -- also have to handle proper modular reduction for binary modular.
8233 -- Maximum shift count with no overflow
8236 -- Set True if we must test the shift count
8239 -- Node for test against TestS
8242 -- Compute maximum shift based on the underlying size. For a
8243 -- modular type this is one less than the size.
8245 if Is_Modular_Integer_Type
(Typ
) then
8247 -- For modular integer types, this is the size of the value
8248 -- being shifted minus one. Any larger values will cause
8249 -- modular reduction to a result of zero. Note that we do
8250 -- want the RM_Size here (e.g. mod 2 ** 7, we want a result
8251 -- of 6, since 2**7 should be reduced to zero).
8253 MaxS
:= RM_Size
(Rtyp
) - 1;
8255 -- For signed integer types, we use the size of the value
8256 -- being shifted minus 2. Larger values cause overflow.
8259 MaxS
:= Esize
(Rtyp
) - 2;
8262 -- Determine range to see if it can be larger than MaxS
8265 (Right_Opnd
(N
), OK
, Lo
, Hi
, Assume_Valid
=> True);
8266 TestS
:= (not OK
) or else Hi
> MaxS
;
8268 -- Signed integer case
8270 if Is_Signed_Integer_Type
(Typ
) then
8272 -- Generate overflow check if overflow is active. Note that
8273 -- we can simply ignore the possibility of overflow if the
8274 -- flag is not set (means that overflow cannot happen or
8275 -- that overflow checks are suppressed).
8277 if Ovflo
and TestS
then
8279 Make_Raise_Constraint_Error
(Loc
,
8282 Left_Opnd
=> Duplicate_Subexpr
(Right_Opnd
(N
)),
8283 Right_Opnd
=> Make_Integer_Literal
(Loc
, MaxS
)),
8284 Reason
=> CE_Overflow_Check_Failed
));
8287 -- Now rewrite node as Shift_Left (1, right-operand)
8290 Make_Op_Shift_Left
(Loc
,
8291 Left_Opnd
=> Make_Integer_Literal
(Loc
, Uint_1
),
8292 Right_Opnd
=> Right_Opnd
(N
)));
8294 -- Modular integer case
8296 else pragma Assert
(Is_Modular_Integer_Type
(Typ
));
8298 -- If shift count can be greater than MaxS, we need to wrap
8299 -- the shift in a test that will reduce the result value to
8300 -- zero if this shift count is exceeded.
8304 -- Note: build node for the comparison first, before we
8305 -- reuse the Right_Opnd, so that we have proper parents
8306 -- in place for the Duplicate_Subexpr call.
8310 Left_Opnd
=> Duplicate_Subexpr
(Right_Opnd
(N
)),
8311 Right_Opnd
=> Make_Integer_Literal
(Loc
, MaxS
));
8314 Make_If_Expression
(Loc
,
8315 Expressions
=> New_List
(
8317 Make_Integer_Literal
(Loc
, Uint_0
),
8318 Make_Op_Shift_Left
(Loc
,
8319 Left_Opnd
=> Make_Integer_Literal
(Loc
, Uint_1
),
8320 Right_Opnd
=> Right_Opnd
(N
)))));
8322 -- If we know shift count cannot be greater than MaxS, then
8323 -- it is safe to just rewrite as a shift with no test.
8327 Make_Op_Shift_Left
(Loc
,
8328 Left_Opnd
=> Make_Integer_Literal
(Loc
, Uint_1
),
8329 Right_Opnd
=> Right_Opnd
(N
)));
8333 Analyze_And_Resolve
(N
, Typ
);
8339 -- Fall through if exponentiation must be done using a runtime routine
8341 -- First deal with modular case
8343 if Is_Modular_Integer_Type
(Rtyp
) then
8345 -- Nonbinary modular case, we call the special exponentiation
8346 -- routine for the nonbinary case, converting the argument to
8347 -- Long_Long_Integer and passing the modulus value. Then the
8348 -- result is converted back to the base type.
8350 if Non_Binary_Modulus
(Rtyp
) then
8353 Make_Function_Call
(Loc
,
8355 New_Occurrence_Of
(RTE
(RE_Exp_Modular
), Loc
),
8356 Parameter_Associations
=> New_List
(
8357 Convert_To
(RTE
(RE_Unsigned
), Base
),
8358 Make_Integer_Literal
(Loc
, Modulus
(Rtyp
)),
8361 -- Binary modular case, in this case, we call one of two routines,
8362 -- either the unsigned integer case, or the unsigned long long
8363 -- integer case, with a final "and" operation to do the required mod.
8366 if UI_To_Int
(Esize
(Rtyp
)) <= Standard_Integer_Size
then
8367 Ent
:= RTE
(RE_Exp_Unsigned
);
8369 Ent
:= RTE
(RE_Exp_Long_Long_Unsigned
);
8376 Make_Function_Call
(Loc
,
8377 Name
=> New_Occurrence_Of
(Ent
, Loc
),
8378 Parameter_Associations
=> New_List
(
8379 Convert_To
(Etype
(First_Formal
(Ent
)), Base
),
8382 Make_Integer_Literal
(Loc
, Modulus
(Rtyp
) - 1))));
8386 -- Common exit point for modular type case
8388 Analyze_And_Resolve
(N
, Typ
);
8391 -- Signed integer cases, done using either Integer or Long_Long_Integer.
8392 -- It is not worth having routines for Short_[Short_]Integer, since for
8393 -- most machines it would not help, and it would generate more code that
8394 -- might need certification when a certified run time is required.
8396 -- In the integer cases, we have two routines, one for when overflow
8397 -- checks are required, and one when they are not required, since there
8398 -- is a real gain in omitting checks on many machines.
8400 elsif Rtyp
= Base_Type
(Standard_Long_Long_Integer
)
8401 or else (Rtyp
= Base_Type
(Standard_Long_Integer
)
8403 Esize
(Standard_Long_Integer
) > Esize
(Standard_Integer
))
8404 or else Rtyp
= Universal_Integer
8406 Etyp
:= Standard_Long_Long_Integer
;
8409 Rent
:= RE_Exp_Long_Long_Integer
;
8411 Rent
:= RE_Exn_Long_Long_Integer
;
8414 elsif Is_Signed_Integer_Type
(Rtyp
) then
8415 Etyp
:= Standard_Integer
;
8418 Rent
:= RE_Exp_Integer
;
8420 Rent
:= RE_Exn_Integer
;
8423 -- Floating-point cases. We do not need separate routines for the
8424 -- overflow case here, since in the case of floating-point, we generate
8425 -- infinities anyway as a rule (either that or we automatically trap
8426 -- overflow), and if there is an infinity generated and a range check
8427 -- is required, the check will fail anyway.
8429 -- Historical note: we used to convert everything to Long_Long_Float
8430 -- and call a single common routine, but this had the undesirable effect
8431 -- of giving different results for small static exponent values and the
8432 -- same dynamic values.
8435 pragma Assert
(Is_Floating_Point_Type
(Rtyp
));
8437 if Rtyp
= Standard_Float
then
8438 Etyp
:= Standard_Float
;
8439 Rent
:= RE_Exn_Float
;
8441 elsif Rtyp
= Standard_Long_Float
then
8442 Etyp
:= Standard_Long_Float
;
8443 Rent
:= RE_Exn_Long_Float
;
8446 Etyp
:= Standard_Long_Long_Float
;
8447 Rent
:= RE_Exn_Long_Long_Float
;
8451 -- Common processing for integer cases and floating-point cases.
8452 -- If we are in the right type, we can call runtime routine directly
8455 and then Rtyp
/= Universal_Integer
8456 and then Rtyp
/= Universal_Real
8460 Make_Function_Call
(Loc
,
8461 Name
=> New_Occurrence_Of
(RTE
(Rent
), Loc
),
8462 Parameter_Associations
=> New_List
(Base
, Exp
))));
8464 -- Otherwise we have to introduce conversions (conversions are also
8465 -- required in the universal cases, since the runtime routine is
8466 -- typed using one of the standard types).
8471 Make_Function_Call
(Loc
,
8472 Name
=> New_Occurrence_Of
(RTE
(Rent
), Loc
),
8473 Parameter_Associations
=> New_List
(
8474 Convert_To
(Etyp
, Base
),
8478 Analyze_And_Resolve
(N
, Typ
);
8482 when RE_Not_Available
=>
8484 end Expand_N_Op_Expon
;
8486 --------------------
8487 -- Expand_N_Op_Ge --
8488 --------------------
8490 procedure Expand_N_Op_Ge
(N
: Node_Id
) is
8491 Typ
: constant Entity_Id
:= Etype
(N
);
8492 Op1
: constant Node_Id
:= Left_Opnd
(N
);
8493 Op2
: constant Node_Id
:= Right_Opnd
(N
);
8494 Typ1
: constant Entity_Id
:= Base_Type
(Etype
(Op1
));
8497 Binary_Op_Validity_Checks
(N
);
8499 -- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
8500 -- means we no longer have a comparison operation, we are all done.
8502 Expand_Compare_Minimize_Eliminate_Overflow
(N
);
8504 if Nkind
(N
) /= N_Op_Ge
then
8510 if Is_Array_Type
(Typ1
) then
8511 Expand_Array_Comparison
(N
);
8515 -- Deal with boolean operands
8517 if Is_Boolean_Type
(Typ1
) then
8518 Adjust_Condition
(Op1
);
8519 Adjust_Condition
(Op2
);
8520 Set_Etype
(N
, Standard_Boolean
);
8521 Adjust_Result_Type
(N
, Typ
);
8524 Rewrite_Comparison
(N
);
8526 Optimize_Length_Comparison
(N
);
8529 --------------------
8530 -- Expand_N_Op_Gt --
8531 --------------------
8533 procedure Expand_N_Op_Gt
(N
: Node_Id
) is
8534 Typ
: constant Entity_Id
:= Etype
(N
);
8535 Op1
: constant Node_Id
:= Left_Opnd
(N
);
8536 Op2
: constant Node_Id
:= Right_Opnd
(N
);
8537 Typ1
: constant Entity_Id
:= Base_Type
(Etype
(Op1
));
8540 Binary_Op_Validity_Checks
(N
);
8542 -- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
8543 -- means we no longer have a comparison operation, we are all done.
8545 Expand_Compare_Minimize_Eliminate_Overflow
(N
);
8547 if Nkind
(N
) /= N_Op_Gt
then
8551 -- Deal with array type operands
8553 if Is_Array_Type
(Typ1
) then
8554 Expand_Array_Comparison
(N
);
8558 -- Deal with boolean type operands
8560 if Is_Boolean_Type
(Typ1
) then
8561 Adjust_Condition
(Op1
);
8562 Adjust_Condition
(Op2
);
8563 Set_Etype
(N
, Standard_Boolean
);
8564 Adjust_Result_Type
(N
, Typ
);
8567 Rewrite_Comparison
(N
);
8569 Optimize_Length_Comparison
(N
);
8572 --------------------
8573 -- Expand_N_Op_Le --
8574 --------------------
8576 procedure Expand_N_Op_Le
(N
: Node_Id
) is
8577 Typ
: constant Entity_Id
:= Etype
(N
);
8578 Op1
: constant Node_Id
:= Left_Opnd
(N
);
8579 Op2
: constant Node_Id
:= Right_Opnd
(N
);
8580 Typ1
: constant Entity_Id
:= Base_Type
(Etype
(Op1
));
8583 Binary_Op_Validity_Checks
(N
);
8585 -- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
8586 -- means we no longer have a comparison operation, we are all done.
8588 Expand_Compare_Minimize_Eliminate_Overflow
(N
);
8590 if Nkind
(N
) /= N_Op_Le
then
8594 -- Deal with array type operands
8596 if Is_Array_Type
(Typ1
) then
8597 Expand_Array_Comparison
(N
);
8601 -- Deal with Boolean type operands
8603 if Is_Boolean_Type
(Typ1
) then
8604 Adjust_Condition
(Op1
);
8605 Adjust_Condition
(Op2
);
8606 Set_Etype
(N
, Standard_Boolean
);
8607 Adjust_Result_Type
(N
, Typ
);
8610 Rewrite_Comparison
(N
);
8612 Optimize_Length_Comparison
(N
);
8615 --------------------
8616 -- Expand_N_Op_Lt --
8617 --------------------
8619 procedure Expand_N_Op_Lt
(N
: Node_Id
) is
8620 Typ
: constant Entity_Id
:= Etype
(N
);
8621 Op1
: constant Node_Id
:= Left_Opnd
(N
);
8622 Op2
: constant Node_Id
:= Right_Opnd
(N
);
8623 Typ1
: constant Entity_Id
:= Base_Type
(Etype
(Op1
));
8626 Binary_Op_Validity_Checks
(N
);
8628 -- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if that
8629 -- means we no longer have a comparison operation, we are all done.
8631 Expand_Compare_Minimize_Eliminate_Overflow
(N
);
8633 if Nkind
(N
) /= N_Op_Lt
then
8637 -- Deal with array type operands
8639 if Is_Array_Type
(Typ1
) then
8640 Expand_Array_Comparison
(N
);
8644 -- Deal with Boolean type operands
8646 if Is_Boolean_Type
(Typ1
) then
8647 Adjust_Condition
(Op1
);
8648 Adjust_Condition
(Op2
);
8649 Set_Etype
(N
, Standard_Boolean
);
8650 Adjust_Result_Type
(N
, Typ
);
8653 Rewrite_Comparison
(N
);
8655 Optimize_Length_Comparison
(N
);
8658 -----------------------
8659 -- Expand_N_Op_Minus --
8660 -----------------------
8662 procedure Expand_N_Op_Minus
(N
: Node_Id
) is
8663 Loc
: constant Source_Ptr
:= Sloc
(N
);
8664 Typ
: constant Entity_Id
:= Etype
(N
);
8667 Unary_Op_Validity_Checks
(N
);
8669 -- Check for MINIMIZED/ELIMINATED overflow mode
8671 if Minimized_Eliminated_Overflow_Check
(N
) then
8672 Apply_Arithmetic_Overflow_Check
(N
);
8676 if not Backend_Overflow_Checks_On_Target
8677 and then Is_Signed_Integer_Type
(Etype
(N
))
8678 and then Do_Overflow_Check
(N
)
8680 -- Software overflow checking expands -expr into (0 - expr)
8683 Make_Op_Subtract
(Loc
,
8684 Left_Opnd
=> Make_Integer_Literal
(Loc
, 0),
8685 Right_Opnd
=> Right_Opnd
(N
)));
8687 Analyze_And_Resolve
(N
, Typ
);
8690 -- When generating C code, convert nonbinary modular minus into code
8691 -- that relies on the front-end expansion of operator Mod.
8693 if Modify_Tree_For_C
then
8694 Expand_Nonbinary_Modular_Op
(N
);
8696 end Expand_N_Op_Minus
;
8698 ---------------------
8699 -- Expand_N_Op_Mod --
8700 ---------------------
8702 procedure Expand_N_Op_Mod
(N
: Node_Id
) is
8703 Loc
: constant Source_Ptr
:= Sloc
(N
);
8704 Typ
: constant Entity_Id
:= Etype
(N
);
8705 DDC
: constant Boolean := Do_Division_Check
(N
);
8718 pragma Warnings
(Off
, Lhi
);
8721 Binary_Op_Validity_Checks
(N
);
8723 -- Check for MINIMIZED/ELIMINATED overflow mode
8725 if Minimized_Eliminated_Overflow_Check
(N
) then
8726 Apply_Arithmetic_Overflow_Check
(N
);
8730 if Is_Integer_Type
(Etype
(N
)) then
8731 Apply_Divide_Checks
(N
);
8733 -- All done if we don't have a MOD any more, which can happen as a
8734 -- result of overflow expansion in MINIMIZED or ELIMINATED modes.
8736 if Nkind
(N
) /= N_Op_Mod
then
8741 -- Proceed with expansion of mod operator
8743 Left
:= Left_Opnd
(N
);
8744 Right
:= Right_Opnd
(N
);
8746 Determine_Range
(Right
, ROK
, Rlo
, Rhi
, Assume_Valid
=> True);
8747 Determine_Range
(Left
, LOK
, Llo
, Lhi
, Assume_Valid
=> True);
8749 -- Convert mod to rem if operands are both known to be non-negative, or
8750 -- both known to be non-positive (these are the cases in which rem and
8751 -- mod are the same, see (RM 4.5.5(28-30)). We do this since it is quite
8752 -- likely that this will improve the quality of code, (the operation now
8753 -- corresponds to the hardware remainder), and it does not seem likely
8754 -- that it could be harmful. It also avoids some cases of the elaborate
8755 -- expansion in Modify_Tree_For_C mode below (since Ada rem = C %).
8758 and then ((Llo
>= 0 and then Rlo
>= 0)
8760 (Lhi
<= 0 and then Rhi
<= 0))
8763 Make_Op_Rem
(Sloc
(N
),
8764 Left_Opnd
=> Left_Opnd
(N
),
8765 Right_Opnd
=> Right_Opnd
(N
)));
8767 -- Instead of reanalyzing the node we do the analysis manually. This
8768 -- avoids anomalies when the replacement is done in an instance and
8769 -- is epsilon more efficient.
8771 Set_Entity
(N
, Standard_Entity
(S_Op_Rem
));
8773 Set_Do_Division_Check
(N
, DDC
);
8774 Expand_N_Op_Rem
(N
);
8778 -- Otherwise, normal mod processing
8781 -- Apply optimization x mod 1 = 0. We don't really need that with
8782 -- gcc, but it is useful with other back ends and is certainly
8785 if Is_Integer_Type
(Etype
(N
))
8786 and then Compile_Time_Known_Value
(Right
)
8787 and then Expr_Value
(Right
) = Uint_1
8789 -- Call Remove_Side_Effects to ensure that any side effects in
8790 -- the ignored left operand (in particular function calls to
8791 -- user defined functions) are properly executed.
8793 Remove_Side_Effects
(Left
);
8795 Rewrite
(N
, Make_Integer_Literal
(Loc
, 0));
8796 Analyze_And_Resolve
(N
, Typ
);
8800 -- If we still have a mod operator and we are in Modify_Tree_For_C
8801 -- mode, and we have a signed integer type, then here is where we do
8802 -- the rewrite in terms of Rem. Note this rewrite bypasses the need
8803 -- for the special handling of the annoying case of largest negative
8804 -- number mod minus one.
8806 if Nkind
(N
) = N_Op_Mod
8807 and then Is_Signed_Integer_Type
(Typ
)
8808 and then Modify_Tree_For_C
8810 -- In the general case, we expand A mod B as
8812 -- Tnn : constant typ := A rem B;
8814 -- (if (A >= 0) = (B >= 0) then Tnn
8815 -- elsif Tnn = 0 then 0
8818 -- The comparison can be written simply as A >= 0 if we know that
8819 -- B >= 0 which is a very common case.
8821 -- An important optimization is when B is known at compile time
8822 -- to be 2**K for some constant. In this case we can simply AND
8823 -- the left operand with the bit string 2**K-1 (i.e. K 1-bits)
8824 -- and that works for both the positive and negative cases.
8827 P2
: constant Nat
:= Power_Of_Two
(Right
);
8832 Unchecked_Convert_To
(Typ
,
8835 Unchecked_Convert_To
8836 (Corresponding_Unsigned_Type
(Typ
), Left
),
8838 Make_Integer_Literal
(Loc
, 2 ** P2
- 1))));
8839 Analyze_And_Resolve
(N
, Typ
);
8844 -- Here for the full rewrite
8847 Tnn
: constant Entity_Id
:= Make_Temporary
(Sloc
(N
), 'T', N
);
8853 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Left
),
8854 Right_Opnd
=> Make_Integer_Literal
(Loc
, 0));
8856 if not LOK
or else Rlo
< 0 then
8862 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Right
),
8863 Right_Opnd
=> Make_Integer_Literal
(Loc
, 0)));
8867 Make_Object_Declaration
(Loc
,
8868 Defining_Identifier
=> Tnn
,
8869 Constant_Present
=> True,
8870 Object_Definition
=> New_Occurrence_Of
(Typ
, Loc
),
8874 Right_Opnd
=> Right
)));
8877 Make_If_Expression
(Loc
,
8878 Expressions
=> New_List
(
8880 New_Occurrence_Of
(Tnn
, Loc
),
8881 Make_If_Expression
(Loc
,
8883 Expressions
=> New_List
(
8885 Left_Opnd
=> New_Occurrence_Of
(Tnn
, Loc
),
8886 Right_Opnd
=> Make_Integer_Literal
(Loc
, 0)),
8887 Make_Integer_Literal
(Loc
, 0),
8889 Left_Opnd
=> New_Occurrence_Of
(Tnn
, Loc
),
8891 Duplicate_Subexpr_No_Checks
(Right
)))))));
8893 Analyze_And_Resolve
(N
, Typ
);
8898 -- Deal with annoying case of largest negative number mod minus one.
8899 -- Gigi may not handle this case correctly, because on some targets,
8900 -- the mod value is computed using a divide instruction which gives
8901 -- an overflow trap for this case.
8903 -- It would be a bit more efficient to figure out which targets
8904 -- this is really needed for, but in practice it is reasonable
8905 -- to do the following special check in all cases, since it means
8906 -- we get a clearer message, and also the overhead is minimal given
8907 -- that division is expensive in any case.
8909 -- In fact the check is quite easy, if the right operand is -1, then
8910 -- the mod value is always 0, and we can just ignore the left operand
8911 -- completely in this case.
8913 -- This only applies if we still have a mod operator. Skip if we
8914 -- have already rewritten this (e.g. in the case of eliminated
8915 -- overflow checks which have driven us into bignum mode).
8917 if Nkind
(N
) = N_Op_Mod
then
8919 -- The operand type may be private (e.g. in the expansion of an
8920 -- intrinsic operation) so we must use the underlying type to get
8921 -- the bounds, and convert the literals explicitly.
8925 (Type_Low_Bound
(Base_Type
(Underlying_Type
(Etype
(Left
)))));
8927 if ((not ROK
) or else (Rlo
<= (-1) and then (-1) <= Rhi
))
8928 and then ((not LOK
) or else (Llo
= LLB
))
8931 Make_If_Expression
(Loc
,
8932 Expressions
=> New_List
(
8934 Left_Opnd
=> Duplicate_Subexpr
(Right
),
8936 Unchecked_Convert_To
(Typ
,
8937 Make_Integer_Literal
(Loc
, -1))),
8938 Unchecked_Convert_To
(Typ
,
8939 Make_Integer_Literal
(Loc
, Uint_0
)),
8940 Relocate_Node
(N
))));
8942 Set_Analyzed
(Next
(Next
(First
(Expressions
(N
)))));
8943 Analyze_And_Resolve
(N
, Typ
);
8947 end Expand_N_Op_Mod
;
8949 --------------------------
8950 -- Expand_N_Op_Multiply --
8951 --------------------------
8953 procedure Expand_N_Op_Multiply
(N
: Node_Id
) is
8954 Loc
: constant Source_Ptr
:= Sloc
(N
);
8955 Lop
: constant Node_Id
:= Left_Opnd
(N
);
8956 Rop
: constant Node_Id
:= Right_Opnd
(N
);
8958 Lp2
: constant Boolean :=
8959 Nkind
(Lop
) = N_Op_Expon
and then Is_Power_Of_2_For_Shift
(Lop
);
8960 Rp2
: constant Boolean :=
8961 Nkind
(Rop
) = N_Op_Expon
and then Is_Power_Of_2_For_Shift
(Rop
);
8963 Ltyp
: constant Entity_Id
:= Etype
(Lop
);
8964 Rtyp
: constant Entity_Id
:= Etype
(Rop
);
8965 Typ
: Entity_Id
:= Etype
(N
);
8968 Binary_Op_Validity_Checks
(N
);
8970 -- Check for MINIMIZED/ELIMINATED overflow mode
8972 if Minimized_Eliminated_Overflow_Check
(N
) then
8973 Apply_Arithmetic_Overflow_Check
(N
);
8977 -- Special optimizations for integer types
8979 if Is_Integer_Type
(Typ
) then
8981 -- N * 0 = 0 for integer types
8983 if Compile_Time_Known_Value
(Rop
)
8984 and then Expr_Value
(Rop
) = Uint_0
8986 -- Call Remove_Side_Effects to ensure that any side effects in
8987 -- the ignored left operand (in particular function calls to
8988 -- user defined functions) are properly executed.
8990 Remove_Side_Effects
(Lop
);
8992 Rewrite
(N
, Make_Integer_Literal
(Loc
, Uint_0
));
8993 Analyze_And_Resolve
(N
, Typ
);
8997 -- Similar handling for 0 * N = 0
8999 if Compile_Time_Known_Value
(Lop
)
9000 and then Expr_Value
(Lop
) = Uint_0
9002 Remove_Side_Effects
(Rop
);
9003 Rewrite
(N
, Make_Integer_Literal
(Loc
, Uint_0
));
9004 Analyze_And_Resolve
(N
, Typ
);
9008 -- N * 1 = 1 * N = N for integer types
9010 -- This optimisation is not done if we are going to
9011 -- rewrite the product 1 * 2 ** N to a shift.
9013 if Compile_Time_Known_Value
(Rop
)
9014 and then Expr_Value
(Rop
) = Uint_1
9020 elsif Compile_Time_Known_Value
(Lop
)
9021 and then Expr_Value
(Lop
) = Uint_1
9029 -- Convert x * 2 ** y to Shift_Left (x, y). Note that the fact that
9030 -- Is_Power_Of_2_For_Shift is set means that we know that our left
9031 -- operand is an integer, as required for this to work.
9036 -- Convert 2 ** A * 2 ** B into 2 ** (A + B)
9040 Left_Opnd
=> Make_Integer_Literal
(Loc
, 2),
9043 Left_Opnd
=> Right_Opnd
(Lop
),
9044 Right_Opnd
=> Right_Opnd
(Rop
))));
9045 Analyze_And_Resolve
(N
, Typ
);
9049 -- If the result is modular, perform the reduction of the result
9052 if Is_Modular_Integer_Type
(Typ
)
9053 and then not Non_Binary_Modulus
(Typ
)
9058 Make_Op_Shift_Left
(Loc
,
9061 Convert_To
(Standard_Natural
, Right_Opnd
(Rop
))),
9063 Make_Integer_Literal
(Loc
, Modulus
(Typ
) - 1)));
9067 Make_Op_Shift_Left
(Loc
,
9070 Convert_To
(Standard_Natural
, Right_Opnd
(Rop
))));
9073 Analyze_And_Resolve
(N
, Typ
);
9077 -- Same processing for the operands the other way round
9080 if Is_Modular_Integer_Type
(Typ
)
9081 and then not Non_Binary_Modulus
(Typ
)
9086 Make_Op_Shift_Left
(Loc
,
9089 Convert_To
(Standard_Natural
, Right_Opnd
(Lop
))),
9091 Make_Integer_Literal
(Loc
, Modulus
(Typ
) - 1)));
9095 Make_Op_Shift_Left
(Loc
,
9098 Convert_To
(Standard_Natural
, Right_Opnd
(Lop
))));
9101 Analyze_And_Resolve
(N
, Typ
);
9105 -- Do required fixup of universal fixed operation
9107 if Typ
= Universal_Fixed
then
9108 Fixup_Universal_Fixed_Operation
(N
);
9112 -- Multiplications with fixed-point results
9114 if Is_Fixed_Point_Type
(Typ
) then
9116 -- No special processing if Treat_Fixed_As_Integer is set, since from
9117 -- a semantic point of view such operations are simply integer
9118 -- operations and will be treated that way.
9120 if not Treat_Fixed_As_Integer
(N
) then
9122 -- Case of fixed * integer => fixed
9124 if Is_Integer_Type
(Rtyp
) then
9125 Expand_Multiply_Fixed_By_Integer_Giving_Fixed
(N
);
9127 -- Case of integer * fixed => fixed
9129 elsif Is_Integer_Type
(Ltyp
) then
9130 Expand_Multiply_Integer_By_Fixed_Giving_Fixed
(N
);
9132 -- Case of fixed * fixed => fixed
9135 Expand_Multiply_Fixed_By_Fixed_Giving_Fixed
(N
);
9139 -- Other cases of multiplication of fixed-point operands. Again we
9140 -- exclude the cases where Treat_Fixed_As_Integer flag is set.
9142 elsif (Is_Fixed_Point_Type
(Ltyp
) or else Is_Fixed_Point_Type
(Rtyp
))
9143 and then not Treat_Fixed_As_Integer
(N
)
9145 if Is_Integer_Type
(Typ
) then
9146 Expand_Multiply_Fixed_By_Fixed_Giving_Integer
(N
);
9148 pragma Assert
(Is_Floating_Point_Type
(Typ
));
9149 Expand_Multiply_Fixed_By_Fixed_Giving_Float
(N
);
9152 -- Mixed-mode operations can appear in a non-static universal context,
9153 -- in which case the integer argument must be converted explicitly.
9155 elsif Typ
= Universal_Real
and then Is_Integer_Type
(Rtyp
) then
9156 Rewrite
(Rop
, Convert_To
(Universal_Real
, Relocate_Node
(Rop
)));
9157 Analyze_And_Resolve
(Rop
, Universal_Real
);
9159 elsif Typ
= Universal_Real
and then Is_Integer_Type
(Ltyp
) then
9160 Rewrite
(Lop
, Convert_To
(Universal_Real
, Relocate_Node
(Lop
)));
9161 Analyze_And_Resolve
(Lop
, Universal_Real
);
9163 -- Non-fixed point cases, check software overflow checking required
9165 elsif Is_Signed_Integer_Type
(Etype
(N
)) then
9166 Apply_Arithmetic_Overflow_Check
(N
);
9169 -- Overflow checks for floating-point if -gnateF mode active
9171 Check_Float_Op_Overflow
(N
);
9173 -- When generating C code, convert nonbinary modular multiplications
9174 -- into code that relies on the front-end expansion of operator Mod.
9176 if Modify_Tree_For_C
then
9177 Expand_Nonbinary_Modular_Op
(N
);
9179 end Expand_N_Op_Multiply
;
9181 --------------------
9182 -- Expand_N_Op_Ne --
9183 --------------------
9185 procedure Expand_N_Op_Ne
(N
: Node_Id
) is
9186 Typ
: constant Entity_Id
:= Etype
(Left_Opnd
(N
));
9189 -- Case of elementary type with standard operator
9191 if Is_Elementary_Type
(Typ
)
9192 and then Sloc
(Entity
(N
)) = Standard_Location
9194 Binary_Op_Validity_Checks
(N
);
9196 -- Deal with overflow checks in MINIMIZED/ELIMINATED mode and if
9197 -- means we no longer have a /= operation, we are all done.
9199 Expand_Compare_Minimize_Eliminate_Overflow
(N
);
9201 if Nkind
(N
) /= N_Op_Ne
then
9205 -- Boolean types (requiring handling of non-standard case)
9207 if Is_Boolean_Type
(Typ
) then
9208 Adjust_Condition
(Left_Opnd
(N
));
9209 Adjust_Condition
(Right_Opnd
(N
));
9210 Set_Etype
(N
, Standard_Boolean
);
9211 Adjust_Result_Type
(N
, Typ
);
9214 Rewrite_Comparison
(N
);
9216 -- For all cases other than elementary types, we rewrite node as the
9217 -- negation of an equality operation, and reanalyze. The equality to be
9218 -- used is defined in the same scope and has the same signature. This
9219 -- signature must be set explicitly since in an instance it may not have
9220 -- the same visibility as in the generic unit. This avoids duplicating
9221 -- or factoring the complex code for record/array equality tests etc.
9223 -- This case is also used for the minimal expansion performed in
9228 Loc
: constant Source_Ptr
:= Sloc
(N
);
9230 Ne
: constant Entity_Id
:= Entity
(N
);
9233 Binary_Op_Validity_Checks
(N
);
9239 Left_Opnd
=> Left_Opnd
(N
),
9240 Right_Opnd
=> Right_Opnd
(N
)));
9242 -- The level of parentheses is useless in GNATprove mode, and
9243 -- bumping its level here leads to wrong columns being used in
9244 -- check messages, hence skip it in this mode.
9246 if not GNATprove_Mode
then
9247 Set_Paren_Count
(Right_Opnd
(Neg
), 1);
9250 if Scope
(Ne
) /= Standard_Standard
then
9251 Set_Entity
(Right_Opnd
(Neg
), Corresponding_Equality
(Ne
));
9254 -- For navigation purposes, we want to treat the inequality as an
9255 -- implicit reference to the corresponding equality. Preserve the
9256 -- Comes_From_ source flag to generate proper Xref entries.
9258 Preserve_Comes_From_Source
(Neg
, N
);
9259 Preserve_Comes_From_Source
(Right_Opnd
(Neg
), N
);
9261 Analyze_And_Resolve
(N
, Standard_Boolean
);
9265 -- No need for optimization in GNATprove mode, where we would rather see
9266 -- the original source expression.
9268 if not GNATprove_Mode
then
9269 Optimize_Length_Comparison
(N
);
9273 ---------------------
9274 -- Expand_N_Op_Not --
9275 ---------------------
9277 -- If the argument is other than a Boolean array type, there is no special
9278 -- expansion required, except for dealing with validity checks, and non-
9279 -- standard boolean representations.
9281 -- For the packed array case, we call the special routine in Exp_Pakd,
9282 -- except that if the component size is greater than one, we use the
9283 -- standard routine generating a gruesome loop (it is so peculiar to have
9284 -- packed arrays with non-standard Boolean representations anyway, so it
9285 -- does not matter that we do not handle this case efficiently).
9287 -- For the unpacked array case (and for the special packed case where we
9288 -- have non standard Booleans, as discussed above), we generate and insert
9289 -- into the tree the following function definition:
9291 -- function Nnnn (A : arr) is
9294 -- for J in a'range loop
9295 -- B (J) := not A (J);
9300 -- Here arr is the actual subtype of the parameter (and hence always
9301 -- constrained). Then we replace the not with a call to this function.
9303 procedure Expand_N_Op_Not
(N
: Node_Id
) is
9304 Loc
: constant Source_Ptr
:= Sloc
(N
);
9305 Typ
: constant Entity_Id
:= Etype
(N
);
9314 Func_Name
: Entity_Id
;
9315 Loop_Statement
: Node_Id
;
9318 Unary_Op_Validity_Checks
(N
);
9320 -- For boolean operand, deal with non-standard booleans
9322 if Is_Boolean_Type
(Typ
) then
9323 Adjust_Condition
(Right_Opnd
(N
));
9324 Set_Etype
(N
, Standard_Boolean
);
9325 Adjust_Result_Type
(N
, Typ
);
9329 -- Only array types need any other processing
9331 if not Is_Array_Type
(Typ
) then
9335 -- Case of array operand. If bit packed with a component size of 1,
9336 -- handle it in Exp_Pakd if the operand is known to be aligned.
9338 if Is_Bit_Packed_Array
(Typ
)
9339 and then Component_Size
(Typ
) = 1
9340 and then not Is_Possibly_Unaligned_Object
(Right_Opnd
(N
))
9342 Expand_Packed_Not
(N
);
9346 -- Case of array operand which is not bit-packed. If the context is
9347 -- a safe assignment, call in-place operation, If context is a larger
9348 -- boolean expression in the context of a safe assignment, expansion is
9349 -- done by enclosing operation.
9351 Opnd
:= Relocate_Node
(Right_Opnd
(N
));
9352 Convert_To_Actual_Subtype
(Opnd
);
9353 Arr
:= Etype
(Opnd
);
9354 Ensure_Defined
(Arr
, N
);
9355 Silly_Boolean_Array_Not_Test
(N
, Arr
);
9357 if Nkind
(Parent
(N
)) = N_Assignment_Statement
then
9358 if Safe_In_Place_Array_Op
(Name
(Parent
(N
)), N
, Empty
) then
9359 Build_Boolean_Array_Proc_Call
(Parent
(N
), Opnd
, Empty
);
9362 -- Special case the negation of a binary operation
9364 elsif Nkind_In
(Opnd
, N_Op_And
, N_Op_Or
, N_Op_Xor
)
9365 and then Safe_In_Place_Array_Op
9366 (Name
(Parent
(N
)), Left_Opnd
(Opnd
), Right_Opnd
(Opnd
))
9368 Build_Boolean_Array_Proc_Call
(Parent
(N
), Opnd
, Empty
);
9372 elsif Nkind
(Parent
(N
)) in N_Binary_Op
9373 and then Nkind
(Parent
(Parent
(N
))) = N_Assignment_Statement
9376 Op1
: constant Node_Id
:= Left_Opnd
(Parent
(N
));
9377 Op2
: constant Node_Id
:= Right_Opnd
(Parent
(N
));
9378 Lhs
: constant Node_Id
:= Name
(Parent
(Parent
(N
)));
9381 if Safe_In_Place_Array_Op
(Lhs
, Op1
, Op2
) then
9383 -- (not A) op (not B) can be reduced to a single call
9385 if N
= Op1
and then Nkind
(Op2
) = N_Op_Not
then
9388 elsif N
= Op2
and then Nkind
(Op1
) = N_Op_Not
then
9391 -- A xor (not B) can also be special-cased
9393 elsif N
= Op2
and then Nkind
(Parent
(N
)) = N_Op_Xor
then
9400 A
:= Make_Defining_Identifier
(Loc
, Name_uA
);
9401 B
:= Make_Defining_Identifier
(Loc
, Name_uB
);
9402 J
:= Make_Defining_Identifier
(Loc
, Name_uJ
);
9405 Make_Indexed_Component
(Loc
,
9406 Prefix
=> New_Occurrence_Of
(A
, Loc
),
9407 Expressions
=> New_List
(New_Occurrence_Of
(J
, Loc
)));
9410 Make_Indexed_Component
(Loc
,
9411 Prefix
=> New_Occurrence_Of
(B
, Loc
),
9412 Expressions
=> New_List
(New_Occurrence_Of
(J
, Loc
)));
9415 Make_Implicit_Loop_Statement
(N
,
9416 Identifier
=> Empty
,
9419 Make_Iteration_Scheme
(Loc
,
9420 Loop_Parameter_Specification
=>
9421 Make_Loop_Parameter_Specification
(Loc
,
9422 Defining_Identifier
=> J
,
9423 Discrete_Subtype_Definition
=>
9424 Make_Attribute_Reference
(Loc
,
9425 Prefix
=> Make_Identifier
(Loc
, Chars
(A
)),
9426 Attribute_Name
=> Name_Range
))),
9428 Statements
=> New_List
(
9429 Make_Assignment_Statement
(Loc
,
9431 Expression
=> Make_Op_Not
(Loc
, A_J
))));
9433 Func_Name
:= Make_Temporary
(Loc
, 'N');
9434 Set_Is_Inlined
(Func_Name
);
9437 Make_Subprogram_Body
(Loc
,
9439 Make_Function_Specification
(Loc
,
9440 Defining_Unit_Name
=> Func_Name
,
9441 Parameter_Specifications
=> New_List
(
9442 Make_Parameter_Specification
(Loc
,
9443 Defining_Identifier
=> A
,
9444 Parameter_Type
=> New_Occurrence_Of
(Typ
, Loc
))),
9445 Result_Definition
=> New_Occurrence_Of
(Typ
, Loc
)),
9447 Declarations
=> New_List
(
9448 Make_Object_Declaration
(Loc
,
9449 Defining_Identifier
=> B
,
9450 Object_Definition
=> New_Occurrence_Of
(Arr
, Loc
))),
9452 Handled_Statement_Sequence
=>
9453 Make_Handled_Sequence_Of_Statements
(Loc
,
9454 Statements
=> New_List
(
9456 Make_Simple_Return_Statement
(Loc
,
9457 Expression
=> Make_Identifier
(Loc
, Chars
(B
)))))));
9460 Make_Function_Call
(Loc
,
9461 Name
=> New_Occurrence_Of
(Func_Name
, Loc
),
9462 Parameter_Associations
=> New_List
(Opnd
)));
9464 Analyze_And_Resolve
(N
, Typ
);
9465 end Expand_N_Op_Not
;
9467 --------------------
9468 -- Expand_N_Op_Or --
9469 --------------------
9471 procedure Expand_N_Op_Or
(N
: Node_Id
) is
9472 Typ
: constant Entity_Id
:= Etype
(N
);
9475 Binary_Op_Validity_Checks
(N
);
9477 if Is_Array_Type
(Etype
(N
)) then
9478 Expand_Boolean_Operator
(N
);
9480 elsif Is_Boolean_Type
(Etype
(N
)) then
9481 Adjust_Condition
(Left_Opnd
(N
));
9482 Adjust_Condition
(Right_Opnd
(N
));
9483 Set_Etype
(N
, Standard_Boolean
);
9484 Adjust_Result_Type
(N
, Typ
);
9486 elsif Is_Intrinsic_Subprogram
(Entity
(N
)) then
9487 Expand_Intrinsic_Call
(N
, Entity
(N
));
9490 -- When generating C code, convert nonbinary modular operators into code
9491 -- that relies on the front-end expansion of operator Mod.
9493 if Modify_Tree_For_C
then
9494 Expand_Nonbinary_Modular_Op
(N
);
9498 ----------------------
9499 -- Expand_N_Op_Plus --
9500 ----------------------
9502 procedure Expand_N_Op_Plus
(N
: Node_Id
) is
9504 Unary_Op_Validity_Checks
(N
);
9506 -- Check for MINIMIZED/ELIMINATED overflow mode
9508 if Minimized_Eliminated_Overflow_Check
(N
) then
9509 Apply_Arithmetic_Overflow_Check
(N
);
9512 end Expand_N_Op_Plus
;
9514 ---------------------
9515 -- Expand_N_Op_Rem --
9516 ---------------------
9518 procedure Expand_N_Op_Rem
(N
: Node_Id
) is
9519 Loc
: constant Source_Ptr
:= Sloc
(N
);
9520 Typ
: constant Entity_Id
:= Etype
(N
);
9531 -- Set if corresponding operand can be negative
9533 pragma Unreferenced
(Hi
);
9536 Binary_Op_Validity_Checks
(N
);
9538 -- Check for MINIMIZED/ELIMINATED overflow mode
9540 if Minimized_Eliminated_Overflow_Check
(N
) then
9541 Apply_Arithmetic_Overflow_Check
(N
);
9545 if Is_Integer_Type
(Etype
(N
)) then
9546 Apply_Divide_Checks
(N
);
9548 -- All done if we don't have a REM any more, which can happen as a
9549 -- result of overflow expansion in MINIMIZED or ELIMINATED modes.
9551 if Nkind
(N
) /= N_Op_Rem
then
9556 -- Proceed with expansion of REM
9558 Left
:= Left_Opnd
(N
);
9559 Right
:= Right_Opnd
(N
);
9561 -- Apply optimization x rem 1 = 0. We don't really need that with gcc,
9562 -- but it is useful with other back ends, and is certainly harmless.
9564 if Is_Integer_Type
(Etype
(N
))
9565 and then Compile_Time_Known_Value
(Right
)
9566 and then Expr_Value
(Right
) = Uint_1
9568 -- Call Remove_Side_Effects to ensure that any side effects in the
9569 -- ignored left operand (in particular function calls to user defined
9570 -- functions) are properly executed.
9572 Remove_Side_Effects
(Left
);
9574 Rewrite
(N
, Make_Integer_Literal
(Loc
, 0));
9575 Analyze_And_Resolve
(N
, Typ
);
9579 -- Deal with annoying case of largest negative number remainder minus
9580 -- one. Gigi may not handle this case correctly, because on some
9581 -- targets, the mod value is computed using a divide instruction
9582 -- which gives an overflow trap for this case.
9584 -- It would be a bit more efficient to figure out which targets this
9585 -- is really needed for, but in practice it is reasonable to do the
9586 -- following special check in all cases, since it means we get a clearer
9587 -- message, and also the overhead is minimal given that division is
9588 -- expensive in any case.
9590 -- In fact the check is quite easy, if the right operand is -1, then
9591 -- the remainder is always 0, and we can just ignore the left operand
9592 -- completely in this case.
9594 Determine_Range
(Right
, OK
, Lo
, Hi
, Assume_Valid
=> True);
9595 Lneg
:= (not OK
) or else Lo
< 0;
9597 Determine_Range
(Left
, OK
, Lo
, Hi
, Assume_Valid
=> True);
9598 Rneg
:= (not OK
) or else Lo
< 0;
9600 -- We won't mess with trying to find out if the left operand can really
9601 -- be the largest negative number (that's a pain in the case of private
9602 -- types and this is really marginal). We will just assume that we need
9603 -- the test if the left operand can be negative at all.
9605 if Lneg
and Rneg
then
9607 Make_If_Expression
(Loc
,
9608 Expressions
=> New_List
(
9610 Left_Opnd
=> Duplicate_Subexpr
(Right
),
9612 Unchecked_Convert_To
(Typ
, Make_Integer_Literal
(Loc
, -1))),
9614 Unchecked_Convert_To
(Typ
,
9615 Make_Integer_Literal
(Loc
, Uint_0
)),
9617 Relocate_Node
(N
))));
9619 Set_Analyzed
(Next
(Next
(First
(Expressions
(N
)))));
9620 Analyze_And_Resolve
(N
, Typ
);
9622 end Expand_N_Op_Rem
;
9624 -----------------------------
9625 -- Expand_N_Op_Rotate_Left --
9626 -----------------------------
9628 procedure Expand_N_Op_Rotate_Left
(N
: Node_Id
) is
9630 Binary_Op_Validity_Checks
(N
);
9632 -- If we are in Modify_Tree_For_C mode, there is no rotate left in C,
9633 -- so we rewrite in terms of logical shifts
9635 -- Shift_Left (Num, Bits) or Shift_Right (num, Esize - Bits)
9637 -- where Bits is the shift count mod Esize (the mod operation here
9638 -- deals with ludicrous large shift counts, which are apparently OK).
9640 -- What about nonbinary modulus ???
9643 Loc
: constant Source_Ptr
:= Sloc
(N
);
9644 Rtp
: constant Entity_Id
:= Etype
(Right_Opnd
(N
));
9645 Typ
: constant Entity_Id
:= Etype
(N
);
9648 if Modify_Tree_For_C
then
9649 Rewrite
(Right_Opnd
(N
),
9651 Left_Opnd
=> Relocate_Node
(Right_Opnd
(N
)),
9652 Right_Opnd
=> Make_Integer_Literal
(Loc
, Esize
(Typ
))));
9654 Analyze_And_Resolve
(Right_Opnd
(N
), Rtp
);
9659 Make_Op_Shift_Left
(Loc
,
9660 Left_Opnd
=> Left_Opnd
(N
),
9661 Right_Opnd
=> Right_Opnd
(N
)),
9664 Make_Op_Shift_Right
(Loc
,
9665 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Left_Opnd
(N
)),
9667 Make_Op_Subtract
(Loc
,
9668 Left_Opnd
=> Make_Integer_Literal
(Loc
, Esize
(Typ
)),
9670 Duplicate_Subexpr_No_Checks
(Right_Opnd
(N
))))));
9672 Analyze_And_Resolve
(N
, Typ
);
9675 end Expand_N_Op_Rotate_Left
;
9677 ------------------------------
9678 -- Expand_N_Op_Rotate_Right --
9679 ------------------------------
9681 procedure Expand_N_Op_Rotate_Right
(N
: Node_Id
) is
9683 Binary_Op_Validity_Checks
(N
);
9685 -- If we are in Modify_Tree_For_C mode, there is no rotate right in C,
9686 -- so we rewrite in terms of logical shifts
9688 -- Shift_Right (Num, Bits) or Shift_Left (num, Esize - Bits)
9690 -- where Bits is the shift count mod Esize (the mod operation here
9691 -- deals with ludicrous large shift counts, which are apparently OK).
9693 -- What about nonbinary modulus ???
9696 Loc
: constant Source_Ptr
:= Sloc
(N
);
9697 Rtp
: constant Entity_Id
:= Etype
(Right_Opnd
(N
));
9698 Typ
: constant Entity_Id
:= Etype
(N
);
9701 Rewrite
(Right_Opnd
(N
),
9703 Left_Opnd
=> Relocate_Node
(Right_Opnd
(N
)),
9704 Right_Opnd
=> Make_Integer_Literal
(Loc
, Esize
(Typ
))));
9706 Analyze_And_Resolve
(Right_Opnd
(N
), Rtp
);
9708 if Modify_Tree_For_C
then
9712 Make_Op_Shift_Right
(Loc
,
9713 Left_Opnd
=> Left_Opnd
(N
),
9714 Right_Opnd
=> Right_Opnd
(N
)),
9717 Make_Op_Shift_Left
(Loc
,
9718 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Left_Opnd
(N
)),
9720 Make_Op_Subtract
(Loc
,
9721 Left_Opnd
=> Make_Integer_Literal
(Loc
, Esize
(Typ
)),
9723 Duplicate_Subexpr_No_Checks
(Right_Opnd
(N
))))));
9725 Analyze_And_Resolve
(N
, Typ
);
9728 end Expand_N_Op_Rotate_Right
;
9730 ----------------------------
9731 -- Expand_N_Op_Shift_Left --
9732 ----------------------------
9734 -- Note: nothing in this routine depends on left as opposed to right shifts
9735 -- so we share the routine for expanding shift right operations.
9737 procedure Expand_N_Op_Shift_Left
(N
: Node_Id
) is
9739 Binary_Op_Validity_Checks
(N
);
9741 -- If we are in Modify_Tree_For_C mode, then ensure that the right
9742 -- operand is not greater than the word size (since that would not
9743 -- be defined properly by the corresponding C shift operator).
9745 if Modify_Tree_For_C
then
9747 Right
: constant Node_Id
:= Right_Opnd
(N
);
9748 Loc
: constant Source_Ptr
:= Sloc
(Right
);
9749 Typ
: constant Entity_Id
:= Etype
(N
);
9750 Siz
: constant Uint
:= Esize
(Typ
);
9757 if Compile_Time_Known_Value
(Right
) then
9758 if Expr_Value
(Right
) >= Siz
then
9759 Rewrite
(N
, Make_Integer_Literal
(Loc
, 0));
9760 Analyze_And_Resolve
(N
, Typ
);
9763 -- Not compile time known, find range
9766 Determine_Range
(Right
, OK
, Lo
, Hi
, Assume_Valid
=> True);
9768 -- Nothing to do if known to be OK range, otherwise expand
9770 if not OK
or else Hi
>= Siz
then
9772 -- Prevent recursion on copy of shift node
9774 Orig
:= Relocate_Node
(N
);
9775 Set_Analyzed
(Orig
);
9777 -- Now do the rewrite
9780 Make_If_Expression
(Loc
,
9781 Expressions
=> New_List
(
9783 Left_Opnd
=> Duplicate_Subexpr_Move_Checks
(Right
),
9784 Right_Opnd
=> Make_Integer_Literal
(Loc
, Siz
)),
9785 Make_Integer_Literal
(Loc
, 0),
9787 Analyze_And_Resolve
(N
, Typ
);
9792 end Expand_N_Op_Shift_Left
;
9794 -----------------------------
9795 -- Expand_N_Op_Shift_Right --
9796 -----------------------------
9798 procedure Expand_N_Op_Shift_Right
(N
: Node_Id
) is
9800 -- Share shift left circuit
9802 Expand_N_Op_Shift_Left
(N
);
9803 end Expand_N_Op_Shift_Right
;
9805 ----------------------------------------
9806 -- Expand_N_Op_Shift_Right_Arithmetic --
9807 ----------------------------------------
9809 procedure Expand_N_Op_Shift_Right_Arithmetic
(N
: Node_Id
) is
9811 Binary_Op_Validity_Checks
(N
);
9813 -- If we are in Modify_Tree_For_C mode, there is no shift right
9814 -- arithmetic in C, so we rewrite in terms of logical shifts.
9816 -- Shift_Right (Num, Bits) or
9818 -- then not (Shift_Right (Mask, bits))
9821 -- Here Mask is all 1 bits (2**size - 1), and Sign is 2**(size - 1)
9823 -- Note: in almost all C compilers it would work to just shift a
9824 -- signed integer right, but it's undefined and we cannot rely on it.
9826 -- Note: the above works fine for shift counts greater than or equal
9827 -- to the word size, since in this case (not (Shift_Right (Mask, bits)))
9828 -- generates all 1'bits.
9830 -- What about nonbinary modulus ???
9833 Loc
: constant Source_Ptr
:= Sloc
(N
);
9834 Typ
: constant Entity_Id
:= Etype
(N
);
9835 Sign
: constant Uint
:= 2 ** (Esize
(Typ
) - 1);
9836 Mask
: constant Uint
:= (2 ** Esize
(Typ
)) - 1;
9837 Left
: constant Node_Id
:= Left_Opnd
(N
);
9838 Right
: constant Node_Id
:= Right_Opnd
(N
);
9842 if Modify_Tree_For_C
then
9844 -- Here if not (Shift_Right (Mask, bits)) can be computed at
9845 -- compile time as a single constant.
9847 if Compile_Time_Known_Value
(Right
) then
9849 Val
: constant Uint
:= Expr_Value
(Right
);
9852 if Val
>= Esize
(Typ
) then
9853 Maskx
:= Make_Integer_Literal
(Loc
, Mask
);
9857 Make_Integer_Literal
(Loc
,
9858 Intval
=> Mask
- (Mask
/ (2 ** Expr_Value
(Right
))));
9866 Make_Op_Shift_Right
(Loc
,
9867 Left_Opnd
=> Make_Integer_Literal
(Loc
, Mask
),
9868 Right_Opnd
=> Duplicate_Subexpr_No_Checks
(Right
)));
9871 -- Now do the rewrite
9876 Make_Op_Shift_Right
(Loc
,
9878 Right_Opnd
=> Right
),
9880 Make_If_Expression
(Loc
,
9881 Expressions
=> New_List
(
9883 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Left
),
9884 Right_Opnd
=> Make_Integer_Literal
(Loc
, Sign
)),
9886 Make_Integer_Literal
(Loc
, 0)))));
9887 Analyze_And_Resolve
(N
, Typ
);
9890 end Expand_N_Op_Shift_Right_Arithmetic
;
9892 --------------------------
9893 -- Expand_N_Op_Subtract --
9894 --------------------------
9896 procedure Expand_N_Op_Subtract
(N
: Node_Id
) is
9897 Typ
: constant Entity_Id
:= Etype
(N
);
9900 Binary_Op_Validity_Checks
(N
);
9902 -- Check for MINIMIZED/ELIMINATED overflow mode
9904 if Minimized_Eliminated_Overflow_Check
(N
) then
9905 Apply_Arithmetic_Overflow_Check
(N
);
9909 -- N - 0 = N for integer types
9911 if Is_Integer_Type
(Typ
)
9912 and then Compile_Time_Known_Value
(Right_Opnd
(N
))
9913 and then Expr_Value
(Right_Opnd
(N
)) = 0
9915 Rewrite
(N
, Left_Opnd
(N
));
9919 -- Arithmetic overflow checks for signed integer/fixed point types
9921 if Is_Signed_Integer_Type
(Typ
) or else Is_Fixed_Point_Type
(Typ
) then
9922 Apply_Arithmetic_Overflow_Check
(N
);
9925 -- Overflow checks for floating-point if -gnateF mode active
9927 Check_Float_Op_Overflow
(N
);
9929 -- When generating C code, convert nonbinary modular subtractions into
9930 -- code that relies on the front-end expansion of operator Mod.
9932 if Modify_Tree_For_C
then
9933 Expand_Nonbinary_Modular_Op
(N
);
9935 end Expand_N_Op_Subtract
;
9937 ---------------------
9938 -- Expand_N_Op_Xor --
9939 ---------------------
9941 procedure Expand_N_Op_Xor
(N
: Node_Id
) is
9942 Typ
: constant Entity_Id
:= Etype
(N
);
9945 Binary_Op_Validity_Checks
(N
);
9947 if Is_Array_Type
(Etype
(N
)) then
9948 Expand_Boolean_Operator
(N
);
9950 elsif Is_Boolean_Type
(Etype
(N
)) then
9951 Adjust_Condition
(Left_Opnd
(N
));
9952 Adjust_Condition
(Right_Opnd
(N
));
9953 Set_Etype
(N
, Standard_Boolean
);
9954 Adjust_Result_Type
(N
, Typ
);
9956 elsif Is_Intrinsic_Subprogram
(Entity
(N
)) then
9957 Expand_Intrinsic_Call
(N
, Entity
(N
));
9960 end Expand_N_Op_Xor
;
9962 ----------------------
9963 -- Expand_N_Or_Else --
9964 ----------------------
9966 procedure Expand_N_Or_Else
(N
: Node_Id
)
9967 renames Expand_Short_Circuit_Operator
;
9969 -----------------------------------
9970 -- Expand_N_Qualified_Expression --
9971 -----------------------------------
9973 procedure Expand_N_Qualified_Expression
(N
: Node_Id
) is
9974 Operand
: constant Node_Id
:= Expression
(N
);
9975 Target_Type
: constant Entity_Id
:= Entity
(Subtype_Mark
(N
));
9978 -- Do validity check if validity checking operands
9980 if Validity_Checks_On
and Validity_Check_Operands
then
9981 Ensure_Valid
(Operand
);
9984 -- Apply possible constraint check
9986 Apply_Constraint_Check
(Operand
, Target_Type
, No_Sliding
=> True);
9988 if Do_Range_Check
(Operand
) then
9989 Set_Do_Range_Check
(Operand
, False);
9990 Generate_Range_Check
(Operand
, Target_Type
, CE_Range_Check_Failed
);
9992 end Expand_N_Qualified_Expression
;
9994 ------------------------------------
9995 -- Expand_N_Quantified_Expression --
9996 ------------------------------------
10000 -- for all X in range => Cond
10005 -- for X in range loop
10006 -- if not Cond then
10012 -- Similarly, an existentially quantified expression:
10014 -- for some X in range => Cond
10019 -- for X in range loop
10026 -- In both cases, the iteration may be over a container in which case it is
10027 -- given by an iterator specification, not a loop parameter specification.
10029 procedure Expand_N_Quantified_Expression
(N
: Node_Id
) is
10030 Actions
: constant List_Id
:= New_List
;
10031 For_All
: constant Boolean := All_Present
(N
);
10032 Iter_Spec
: constant Node_Id
:= Iterator_Specification
(N
);
10033 Loc
: constant Source_Ptr
:= Sloc
(N
);
10034 Loop_Spec
: constant Node_Id
:= Loop_Parameter_Specification
(N
);
10041 -- Create the declaration of the flag which tracks the status of the
10042 -- quantified expression. Generate:
10044 -- Flag : Boolean := (True | False);
10046 Flag
:= Make_Temporary
(Loc
, 'T', N
);
10048 Append_To
(Actions
,
10049 Make_Object_Declaration
(Loc
,
10050 Defining_Identifier
=> Flag
,
10051 Object_Definition
=> New_Occurrence_Of
(Standard_Boolean
, Loc
),
10053 New_Occurrence_Of
(Boolean_Literals
(For_All
), Loc
)));
10055 -- Construct the circuitry which tracks the status of the quantified
10056 -- expression. Generate:
10058 -- if [not] Cond then
10059 -- Flag := (False | True);
10063 Cond
:= Relocate_Node
(Condition
(N
));
10066 Cond
:= Make_Op_Not
(Loc
, Cond
);
10069 Stmts
:= New_List
(
10070 Make_Implicit_If_Statement
(N
,
10072 Then_Statements
=> New_List
(
10073 Make_Assignment_Statement
(Loc
,
10074 Name
=> New_Occurrence_Of
(Flag
, Loc
),
10076 New_Occurrence_Of
(Boolean_Literals
(not For_All
), Loc
)),
10077 Make_Exit_Statement
(Loc
))));
10079 -- Build the loop equivalent of the quantified expression
10081 if Present
(Iter_Spec
) then
10083 Make_Iteration_Scheme
(Loc
,
10084 Iterator_Specification
=> Iter_Spec
);
10087 Make_Iteration_Scheme
(Loc
,
10088 Loop_Parameter_Specification
=> Loop_Spec
);
10091 Append_To
(Actions
,
10092 Make_Loop_Statement
(Loc
,
10093 Iteration_Scheme
=> Scheme
,
10094 Statements
=> Stmts
,
10095 End_Label
=> Empty
));
10097 -- Transform the quantified expression
10100 Make_Expression_With_Actions
(Loc
,
10101 Expression
=> New_Occurrence_Of
(Flag
, Loc
),
10102 Actions
=> Actions
));
10103 Analyze_And_Resolve
(N
, Standard_Boolean
);
10104 end Expand_N_Quantified_Expression
;
10106 ---------------------------------
10107 -- Expand_N_Selected_Component --
10108 ---------------------------------
10110 procedure Expand_N_Selected_Component
(N
: Node_Id
) is
10111 Loc
: constant Source_Ptr
:= Sloc
(N
);
10112 Par
: constant Node_Id
:= Parent
(N
);
10113 P
: constant Node_Id
:= Prefix
(N
);
10114 S
: constant Node_Id
:= Selector_Name
(N
);
10115 Ptyp
: Entity_Id
:= Underlying_Type
(Etype
(P
));
10121 function In_Left_Hand_Side
(Comp
: Node_Id
) return Boolean;
10122 -- Gigi needs a temporary for prefixes that depend on a discriminant,
10123 -- unless the context of an assignment can provide size information.
10124 -- Don't we have a general routine that does this???
10126 function Is_Subtype_Declaration
return Boolean;
10127 -- The replacement of a discriminant reference by its value is required
10128 -- if this is part of the initialization of an temporary generated by a
10129 -- change of representation. This shows up as the construction of a
10130 -- discriminant constraint for a subtype declared at the same point as
10131 -- the entity in the prefix of the selected component. We recognize this
10132 -- case when the context of the reference is:
10133 -- subtype ST is T(Obj.D);
10134 -- where the entity for Obj comes from source, and ST has the same sloc.
10136 -----------------------
10137 -- In_Left_Hand_Side --
10138 -----------------------
10140 function In_Left_Hand_Side
(Comp
: Node_Id
) return Boolean is
10142 return (Nkind
(Parent
(Comp
)) = N_Assignment_Statement
10143 and then Comp
= Name
(Parent
(Comp
)))
10144 or else (Present
(Parent
(Comp
))
10145 and then Nkind
(Parent
(Comp
)) in N_Subexpr
10146 and then In_Left_Hand_Side
(Parent
(Comp
)));
10147 end In_Left_Hand_Side
;
10149 -----------------------------
10150 -- Is_Subtype_Declaration --
10151 -----------------------------
10153 function Is_Subtype_Declaration
return Boolean is
10154 Par
: constant Node_Id
:= Parent
(N
);
10157 Nkind
(Par
) = N_Index_Or_Discriminant_Constraint
10158 and then Nkind
(Parent
(Parent
(Par
))) = N_Subtype_Declaration
10159 and then Comes_From_Source
(Entity
(Prefix
(N
)))
10160 and then Sloc
(Par
) = Sloc
(Entity
(Prefix
(N
)));
10161 end Is_Subtype_Declaration
;
10163 -- Start of processing for Expand_N_Selected_Component
10166 -- Insert explicit dereference if required
10168 if Is_Access_Type
(Ptyp
) then
10170 -- First set prefix type to proper access type, in case it currently
10171 -- has a private (non-access) view of this type.
10173 Set_Etype
(P
, Ptyp
);
10175 Insert_Explicit_Dereference
(P
);
10176 Analyze_And_Resolve
(P
, Designated_Type
(Ptyp
));
10178 if Ekind
(Etype
(P
)) = E_Private_Subtype
10179 and then Is_For_Access_Subtype
(Etype
(P
))
10181 Set_Etype
(P
, Base_Type
(Etype
(P
)));
10187 -- Deal with discriminant check required
10189 if Do_Discriminant_Check
(N
) then
10190 if Present
(Discriminant_Checking_Func
10191 (Original_Record_Component
(Entity
(S
))))
10193 -- Present the discriminant checking function to the backend, so
10194 -- that it can inline the call to the function.
10197 (Discriminant_Checking_Func
10198 (Original_Record_Component
(Entity
(S
))),
10201 -- Now reset the flag and generate the call
10203 Set_Do_Discriminant_Check
(N
, False);
10204 Generate_Discriminant_Check
(N
);
10206 -- In the case of Unchecked_Union, no discriminant checking is
10207 -- actually performed.
10210 Set_Do_Discriminant_Check
(N
, False);
10214 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
10215 -- function, then additional actuals must be passed.
10217 if Is_Build_In_Place_Function_Call
(P
) then
10218 Make_Build_In_Place_Call_In_Anonymous_Context
(P
);
10220 -- Ada 2005 (AI-318-02): Specialization of the previous case for prefix
10221 -- containing build-in-place function calls whose returned object covers
10222 -- interface types.
10224 elsif Present
(Unqual_BIP_Iface_Function_Call
(P
)) then
10225 Make_Build_In_Place_Iface_Call_In_Anonymous_Context
(P
);
10228 -- Gigi cannot handle unchecked conversions that are the prefix of a
10229 -- selected component with discriminants. This must be checked during
10230 -- expansion, because during analysis the type of the selector is not
10231 -- known at the point the prefix is analyzed. If the conversion is the
10232 -- target of an assignment, then we cannot force the evaluation.
10234 if Nkind
(Prefix
(N
)) = N_Unchecked_Type_Conversion
10235 and then Has_Discriminants
(Etype
(N
))
10236 and then not In_Left_Hand_Side
(N
)
10238 Force_Evaluation
(Prefix
(N
));
10241 -- Remaining processing applies only if selector is a discriminant
10243 if Ekind
(Entity
(Selector_Name
(N
))) = E_Discriminant
then
10245 -- If the selector is a discriminant of a constrained record type,
10246 -- we may be able to rewrite the expression with the actual value
10247 -- of the discriminant, a useful optimization in some cases.
10249 if Is_Record_Type
(Ptyp
)
10250 and then Has_Discriminants
(Ptyp
)
10251 and then Is_Constrained
(Ptyp
)
10253 -- Do this optimization for discrete types only, and not for
10254 -- access types (access discriminants get us into trouble).
10256 if not Is_Discrete_Type
(Etype
(N
)) then
10259 -- Don't do this on the left-hand side of an assignment statement.
10260 -- Normally one would think that references like this would not
10261 -- occur, but they do in generated code, and mean that we really
10262 -- do want to assign the discriminant.
10264 elsif Nkind
(Par
) = N_Assignment_Statement
10265 and then Name
(Par
) = N
10269 -- Don't do this optimization for the prefix of an attribute or
10270 -- the name of an object renaming declaration since these are
10271 -- contexts where we do not want the value anyway.
10273 elsif (Nkind
(Par
) = N_Attribute_Reference
10274 and then Prefix
(Par
) = N
)
10275 or else Is_Renamed_Object
(N
)
10279 -- Don't do this optimization if we are within the code for a
10280 -- discriminant check, since the whole point of such a check may
10281 -- be to verify the condition on which the code below depends.
10283 elsif Is_In_Discriminant_Check
(N
) then
10286 -- Green light to see if we can do the optimization. There is
10287 -- still one condition that inhibits the optimization below but
10288 -- now is the time to check the particular discriminant.
10291 -- Loop through discriminants to find the matching discriminant
10292 -- constraint to see if we can copy it.
10294 Disc
:= First_Discriminant
(Ptyp
);
10295 Dcon
:= First_Elmt
(Discriminant_Constraint
(Ptyp
));
10296 Discr_Loop
: while Present
(Dcon
) loop
10297 Dval
:= Node
(Dcon
);
10299 -- Check if this is the matching discriminant and if the
10300 -- discriminant value is simple enough to make sense to
10301 -- copy. We don't want to copy complex expressions, and
10302 -- indeed to do so can cause trouble (before we put in
10303 -- this guard, a discriminant expression containing an
10304 -- AND THEN was copied, causing problems for coverage
10305 -- analysis tools).
10307 -- However, if the reference is part of the initialization
10308 -- code generated for an object declaration, we must use
10309 -- the discriminant value from the subtype constraint,
10310 -- because the selected component may be a reference to the
10311 -- object being initialized, whose discriminant is not yet
10312 -- set. This only happens in complex cases involving changes
10313 -- or representation.
10315 if Disc
= Entity
(Selector_Name
(N
))
10316 and then (Is_Entity_Name
(Dval
)
10317 or else Compile_Time_Known_Value
(Dval
)
10318 or else Is_Subtype_Declaration
)
10320 -- Here we have the matching discriminant. Check for
10321 -- the case of a discriminant of a component that is
10322 -- constrained by an outer discriminant, which cannot
10323 -- be optimized away.
10325 if Denotes_Discriminant
10326 (Dval
, Check_Concurrent
=> True)
10330 elsif Nkind
(Original_Node
(Dval
)) = N_Selected_Component
10332 Denotes_Discriminant
10333 (Selector_Name
(Original_Node
(Dval
)), True)
10337 -- Do not retrieve value if constraint is not static. It
10338 -- is generally not useful, and the constraint may be a
10339 -- rewritten outer discriminant in which case it is in
10342 elsif Is_Entity_Name
(Dval
)
10344 Nkind
(Parent
(Entity
(Dval
))) = N_Object_Declaration
10345 and then Present
(Expression
(Parent
(Entity
(Dval
))))
10347 Is_OK_Static_Expression
10348 (Expression
(Parent
(Entity
(Dval
))))
10352 -- In the context of a case statement, the expression may
10353 -- have the base type of the discriminant, and we need to
10354 -- preserve the constraint to avoid spurious errors on
10357 elsif Nkind
(Parent
(N
)) = N_Case_Statement
10358 and then Etype
(Dval
) /= Etype
(Disc
)
10361 Make_Qualified_Expression
(Loc
,
10363 New_Occurrence_Of
(Etype
(Disc
), Loc
),
10365 New_Copy_Tree
(Dval
)));
10366 Analyze_And_Resolve
(N
, Etype
(Disc
));
10368 -- In case that comes out as a static expression,
10369 -- reset it (a selected component is never static).
10371 Set_Is_Static_Expression
(N
, False);
10374 -- Otherwise we can just copy the constraint, but the
10375 -- result is certainly not static. In some cases the
10376 -- discriminant constraint has been analyzed in the
10377 -- context of the original subtype indication, but for
10378 -- itypes the constraint might not have been analyzed
10379 -- yet, and this must be done now.
10382 Rewrite
(N
, New_Copy_Tree
(Dval
));
10383 Analyze_And_Resolve
(N
);
10384 Set_Is_Static_Expression
(N
, False);
10390 Next_Discriminant
(Disc
);
10391 end loop Discr_Loop
;
10393 -- Note: the above loop should always find a matching
10394 -- discriminant, but if it does not, we just missed an
10395 -- optimization due to some glitch (perhaps a previous
10396 -- error), so ignore.
10401 -- The only remaining processing is in the case of a discriminant of
10402 -- a concurrent object, where we rewrite the prefix to denote the
10403 -- corresponding record type. If the type is derived and has renamed
10404 -- discriminants, use corresponding discriminant, which is the one
10405 -- that appears in the corresponding record.
10407 if not Is_Concurrent_Type
(Ptyp
) then
10411 Disc
:= Entity
(Selector_Name
(N
));
10413 if Is_Derived_Type
(Ptyp
)
10414 and then Present
(Corresponding_Discriminant
(Disc
))
10416 Disc
:= Corresponding_Discriminant
(Disc
);
10420 Make_Selected_Component
(Loc
,
10422 Unchecked_Convert_To
(Corresponding_Record_Type
(Ptyp
),
10423 New_Copy_Tree
(P
)),
10424 Selector_Name
=> Make_Identifier
(Loc
, Chars
(Disc
)));
10426 Rewrite
(N
, New_N
);
10430 -- Set Atomic_Sync_Required if necessary for atomic component
10432 if Nkind
(N
) = N_Selected_Component
then
10434 E
: constant Entity_Id
:= Entity
(Selector_Name
(N
));
10438 -- If component is atomic, but type is not, setting depends on
10439 -- disable/enable state for the component.
10441 if Is_Atomic
(E
) and then not Is_Atomic
(Etype
(E
)) then
10442 Set
:= not Atomic_Synchronization_Disabled
(E
);
10444 -- If component is not atomic, but its type is atomic, setting
10445 -- depends on disable/enable state for the type.
10447 elsif not Is_Atomic
(E
) and then Is_Atomic
(Etype
(E
)) then
10448 Set
:= not Atomic_Synchronization_Disabled
(Etype
(E
));
10450 -- If both component and type are atomic, we disable if either
10451 -- component or its type have sync disabled.
10453 elsif Is_Atomic
(E
) and then Is_Atomic
(Etype
(E
)) then
10454 Set
:= (not Atomic_Synchronization_Disabled
(E
))
10456 (not Atomic_Synchronization_Disabled
(Etype
(E
)));
10462 -- Set flag if required
10465 Activate_Atomic_Synchronization
(N
);
10469 end Expand_N_Selected_Component
;
10471 --------------------
10472 -- Expand_N_Slice --
10473 --------------------
10475 procedure Expand_N_Slice
(N
: Node_Id
) is
10476 Loc
: constant Source_Ptr
:= Sloc
(N
);
10477 Typ
: constant Entity_Id
:= Etype
(N
);
10479 function Is_Procedure_Actual
(N
: Node_Id
) return Boolean;
10480 -- Check whether the argument is an actual for a procedure call, in
10481 -- which case the expansion of a bit-packed slice is deferred until the
10482 -- call itself is expanded. The reason this is required is that we might
10483 -- have an IN OUT or OUT parameter, and the copy out is essential, and
10484 -- that copy out would be missed if we created a temporary here in
10485 -- Expand_N_Slice. Note that we don't bother to test specifically for an
10486 -- IN OUT or OUT mode parameter, since it is a bit tricky to do, and it
10487 -- is harmless to defer expansion in the IN case, since the call
10488 -- processing will still generate the appropriate copy in operation,
10489 -- which will take care of the slice.
10491 procedure Make_Temporary_For_Slice
;
10492 -- Create a named variable for the value of the slice, in cases where
10493 -- the back end cannot handle it properly, e.g. when packed types or
10494 -- unaligned slices are involved.
10496 -------------------------
10497 -- Is_Procedure_Actual --
10498 -------------------------
10500 function Is_Procedure_Actual
(N
: Node_Id
) return Boolean is
10501 Par
: Node_Id
:= Parent
(N
);
10505 -- If our parent is a procedure call we can return
10507 if Nkind
(Par
) = N_Procedure_Call_Statement
then
10510 -- If our parent is a type conversion, keep climbing the tree,
10511 -- since a type conversion can be a procedure actual. Also keep
10512 -- climbing if parameter association or a qualified expression,
10513 -- since these are additional cases that do can appear on
10514 -- procedure actuals.
10516 elsif Nkind_In
(Par
, N_Type_Conversion
,
10517 N_Parameter_Association
,
10518 N_Qualified_Expression
)
10520 Par
:= Parent
(Par
);
10522 -- Any other case is not what we are looking for
10528 end Is_Procedure_Actual
;
10530 ------------------------------
10531 -- Make_Temporary_For_Slice --
10532 ------------------------------
10534 procedure Make_Temporary_For_Slice
is
10535 Ent
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T', N
);
10540 Make_Object_Declaration
(Loc
,
10541 Defining_Identifier
=> Ent
,
10542 Object_Definition
=> New_Occurrence_Of
(Typ
, Loc
));
10544 Set_No_Initialization
(Decl
);
10546 Insert_Actions
(N
, New_List
(
10548 Make_Assignment_Statement
(Loc
,
10549 Name
=> New_Occurrence_Of
(Ent
, Loc
),
10550 Expression
=> Relocate_Node
(N
))));
10552 Rewrite
(N
, New_Occurrence_Of
(Ent
, Loc
));
10553 Analyze_And_Resolve
(N
, Typ
);
10554 end Make_Temporary_For_Slice
;
10558 Pref
: constant Node_Id
:= Prefix
(N
);
10559 Pref_Typ
: Entity_Id
:= Etype
(Pref
);
10561 -- Start of processing for Expand_N_Slice
10564 -- Special handling for access types
10566 if Is_Access_Type
(Pref_Typ
) then
10567 Pref_Typ
:= Designated_Type
(Pref_Typ
);
10570 Make_Explicit_Dereference
(Sloc
(N
),
10571 Prefix
=> Relocate_Node
(Pref
)));
10573 Analyze_And_Resolve
(Pref
, Pref_Typ
);
10576 -- Ada 2005 (AI-318-02): If the prefix is a call to a build-in-place
10577 -- function, then additional actuals must be passed.
10579 if Is_Build_In_Place_Function_Call
(Pref
) then
10580 Make_Build_In_Place_Call_In_Anonymous_Context
(Pref
);
10582 -- Ada 2005 (AI-318-02): Specialization of the previous case for prefix
10583 -- containing build-in-place function calls whose returned object covers
10584 -- interface types.
10586 elsif Present
(Unqual_BIP_Iface_Function_Call
(Pref
)) then
10587 Make_Build_In_Place_Iface_Call_In_Anonymous_Context
(Pref
);
10590 -- The remaining case to be handled is packed slices. We can leave
10591 -- packed slices as they are in the following situations:
10593 -- 1. Right or left side of an assignment (we can handle this
10594 -- situation correctly in the assignment statement expansion).
10596 -- 2. Prefix of indexed component (the slide is optimized away in this
10597 -- case, see the start of Expand_N_Slice.)
10599 -- 3. Object renaming declaration, since we want the name of the
10600 -- slice, not the value.
10602 -- 4. Argument to procedure call, since copy-in/copy-out handling may
10603 -- be required, and this is handled in the expansion of call
10606 -- 5. Prefix of an address attribute (this is an error which is caught
10607 -- elsewhere, and the expansion would interfere with generating the
10610 if not Is_Packed
(Typ
) then
10612 -- Apply transformation for actuals of a function call, where
10613 -- Expand_Actuals is not used.
10615 if Nkind
(Parent
(N
)) = N_Function_Call
10616 and then Is_Possibly_Unaligned_Slice
(N
)
10618 Make_Temporary_For_Slice
;
10621 elsif Nkind
(Parent
(N
)) = N_Assignment_Statement
10622 or else (Nkind
(Parent
(Parent
(N
))) = N_Assignment_Statement
10623 and then Parent
(N
) = Name
(Parent
(Parent
(N
))))
10627 elsif Nkind
(Parent
(N
)) = N_Indexed_Component
10628 or else Is_Renamed_Object
(N
)
10629 or else Is_Procedure_Actual
(N
)
10633 elsif Nkind
(Parent
(N
)) = N_Attribute_Reference
10634 and then Attribute_Name
(Parent
(N
)) = Name_Address
10639 Make_Temporary_For_Slice
;
10641 end Expand_N_Slice
;
10643 ------------------------------
10644 -- Expand_N_Type_Conversion --
10645 ------------------------------
10647 procedure Expand_N_Type_Conversion
(N
: Node_Id
) is
10648 Loc
: constant Source_Ptr
:= Sloc
(N
);
10649 Operand
: constant Node_Id
:= Expression
(N
);
10650 Target_Type
: constant Entity_Id
:= Etype
(N
);
10651 Operand_Type
: Entity_Id
:= Etype
(Operand
);
10653 procedure Handle_Changed_Representation
;
10654 -- This is called in the case of record and array type conversions to
10655 -- see if there is a change of representation to be handled. Change of
10656 -- representation is actually handled at the assignment statement level,
10657 -- and what this procedure does is rewrite node N conversion as an
10658 -- assignment to temporary. If there is no change of representation,
10659 -- then the conversion node is unchanged.
10661 procedure Raise_Accessibility_Error
;
10662 -- Called when we know that an accessibility check will fail. Rewrites
10663 -- node N to an appropriate raise statement and outputs warning msgs.
10664 -- The Etype of the raise node is set to Target_Type. Note that in this
10665 -- case the rest of the processing should be skipped (i.e. the call to
10666 -- this procedure will be followed by "goto Done").
10668 procedure Real_Range_Check
;
10669 -- Handles generation of range check for real target value
10671 function Has_Extra_Accessibility
(Id
: Entity_Id
) return Boolean;
10672 -- True iff Present (Effective_Extra_Accessibility (Id)) successfully
10673 -- evaluates to True.
10675 -----------------------------------
10676 -- Handle_Changed_Representation --
10677 -----------------------------------
10679 procedure Handle_Changed_Representation
is
10687 -- Nothing else to do if no change of representation
10689 if Same_Representation
(Operand_Type
, Target_Type
) then
10692 -- The real change of representation work is done by the assignment
10693 -- statement processing. So if this type conversion is appearing as
10694 -- the expression of an assignment statement, nothing needs to be
10695 -- done to the conversion.
10697 elsif Nkind
(Parent
(N
)) = N_Assignment_Statement
then
10700 -- Otherwise we need to generate a temporary variable, and do the
10701 -- change of representation assignment into that temporary variable.
10702 -- The conversion is then replaced by a reference to this variable.
10707 -- If type is unconstrained we have to add a constraint, copied
10708 -- from the actual value of the left-hand side.
10710 if not Is_Constrained
(Target_Type
) then
10711 if Has_Discriminants
(Operand_Type
) then
10713 -- A change of representation can only apply to untagged
10714 -- types. We need to build the constraint that applies to
10715 -- the target type, using the constraints of the operand.
10716 -- The analysis is complicated if there are both inherited
10717 -- discriminants and constrained discriminants.
10718 -- We iterate over the discriminants of the target, and
10719 -- find the discriminant of the same name:
10721 -- a) If there is a corresponding discriminant in the object
10722 -- then the value is a selected component of the operand.
10724 -- b) Otherwise the value of a constrained discriminant is
10725 -- found in the stored constraint of the operand.
10728 Stored
: constant Elist_Id
:=
10729 Stored_Constraint
(Operand_Type
);
10733 Disc_O
: Entity_Id
;
10734 -- Discriminant of the operand type. Its value in the
10735 -- object is captured in a selected component.
10737 Disc_S
: Entity_Id
;
10738 -- Stored discriminant of the operand. If present, it
10739 -- corresponds to a constrained discriminant of the
10742 Disc_T
: Entity_Id
;
10743 -- Discriminant of the target type
10746 Disc_T
:= First_Discriminant
(Target_Type
);
10747 Disc_O
:= First_Discriminant
(Operand_Type
);
10748 Disc_S
:= First_Stored_Discriminant
(Operand_Type
);
10750 if Present
(Stored
) then
10751 Elmt
:= First_Elmt
(Stored
);
10753 Elmt
:= No_Elmt
; -- init to avoid warning
10757 while Present
(Disc_T
) loop
10758 if Present
(Disc_O
)
10759 and then Chars
(Disc_T
) = Chars
(Disc_O
)
10762 Make_Selected_Component
(Loc
,
10764 Duplicate_Subexpr_Move_Checks
(Operand
),
10766 Make_Identifier
(Loc
, Chars
(Disc_O
))));
10767 Next_Discriminant
(Disc_O
);
10769 elsif Present
(Disc_S
) then
10770 Append_To
(Cons
, New_Copy_Tree
(Node
(Elmt
)));
10774 Next_Discriminant
(Disc_T
);
10778 elsif Is_Array_Type
(Operand_Type
) then
10779 N_Ix
:= First_Index
(Target_Type
);
10782 for J
in 1 .. Number_Dimensions
(Operand_Type
) loop
10784 -- We convert the bounds explicitly. We use an unchecked
10785 -- conversion because bounds checks are done elsewhere.
10790 Unchecked_Convert_To
(Etype
(N_Ix
),
10791 Make_Attribute_Reference
(Loc
,
10793 Duplicate_Subexpr_No_Checks
10794 (Operand
, Name_Req
=> True),
10795 Attribute_Name
=> Name_First
,
10796 Expressions
=> New_List
(
10797 Make_Integer_Literal
(Loc
, J
)))),
10800 Unchecked_Convert_To
(Etype
(N_Ix
),
10801 Make_Attribute_Reference
(Loc
,
10803 Duplicate_Subexpr_No_Checks
10804 (Operand
, Name_Req
=> True),
10805 Attribute_Name
=> Name_Last
,
10806 Expressions
=> New_List
(
10807 Make_Integer_Literal
(Loc
, J
))))));
10814 Odef
:= New_Occurrence_Of
(Target_Type
, Loc
);
10816 if Present
(Cons
) then
10818 Make_Subtype_Indication
(Loc
,
10819 Subtype_Mark
=> Odef
,
10821 Make_Index_Or_Discriminant_Constraint
(Loc
,
10822 Constraints
=> Cons
));
10825 Temp
:= Make_Temporary
(Loc
, 'C');
10827 Make_Object_Declaration
(Loc
,
10828 Defining_Identifier
=> Temp
,
10829 Object_Definition
=> Odef
);
10831 Set_No_Initialization
(Decl
, True);
10833 -- Insert required actions. It is essential to suppress checks
10834 -- since we have suppressed default initialization, which means
10835 -- that the variable we create may have no discriminants.
10840 Make_Assignment_Statement
(Loc
,
10841 Name
=> New_Occurrence_Of
(Temp
, Loc
),
10842 Expression
=> Relocate_Node
(N
))),
10843 Suppress
=> All_Checks
);
10845 Rewrite
(N
, New_Occurrence_Of
(Temp
, Loc
));
10848 end Handle_Changed_Representation
;
10850 -------------------------------
10851 -- Raise_Accessibility_Error --
10852 -------------------------------
10854 procedure Raise_Accessibility_Error
is
10856 Error_Msg_Warn
:= SPARK_Mode
/= On
;
10858 Make_Raise_Program_Error
(Sloc
(N
),
10859 Reason
=> PE_Accessibility_Check_Failed
));
10860 Set_Etype
(N
, Target_Type
);
10862 Error_Msg_N
("<<accessibility check failure", N
);
10863 Error_Msg_NE
("\<<& [", N
, Standard_Program_Error
);
10864 end Raise_Accessibility_Error
;
10866 ----------------------
10867 -- Real_Range_Check --
10868 ----------------------
10870 -- Case of conversions to floating-point or fixed-point. If range checks
10871 -- are enabled and the target type has a range constraint, we convert:
10877 -- Tnn : typ'Base := typ'Base (x);
10878 -- [constraint_error when Tnn < typ'First or else Tnn > typ'Last]
10881 -- This is necessary when there is a conversion of integer to float or
10882 -- to fixed-point to ensure that the correct checks are made. It is not
10883 -- necessary for float to float where it is enough to simply set the
10884 -- Do_Range_Check flag.
10886 procedure Real_Range_Check
is
10887 Btyp
: constant Entity_Id
:= Base_Type
(Target_Type
);
10888 Lo
: constant Node_Id
:= Type_Low_Bound
(Target_Type
);
10889 Hi
: constant Node_Id
:= Type_High_Bound
(Target_Type
);
10890 Xtyp
: constant Entity_Id
:= Etype
(Operand
);
10895 -- Nothing to do if conversion was rewritten
10897 if Nkind
(N
) /= N_Type_Conversion
then
10901 -- Nothing to do if range checks suppressed, or target has the same
10902 -- range as the base type (or is the base type).
10904 if Range_Checks_Suppressed
(Target_Type
)
10905 or else (Lo
= Type_Low_Bound
(Btyp
)
10907 Hi
= Type_High_Bound
(Btyp
))
10912 -- Nothing to do if expression is an entity on which checks have been
10915 if Is_Entity_Name
(Operand
)
10916 and then Range_Checks_Suppressed
(Entity
(Operand
))
10921 -- Nothing to do if bounds are all static and we can tell that the
10922 -- expression is within the bounds of the target. Note that if the
10923 -- operand is of an unconstrained floating-point type, then we do
10924 -- not trust it to be in range (might be infinite)
10927 S_Lo
: constant Node_Id
:= Type_Low_Bound
(Xtyp
);
10928 S_Hi
: constant Node_Id
:= Type_High_Bound
(Xtyp
);
10931 if (not Is_Floating_Point_Type
(Xtyp
)
10932 or else Is_Constrained
(Xtyp
))
10933 and then Compile_Time_Known_Value
(S_Lo
)
10934 and then Compile_Time_Known_Value
(S_Hi
)
10935 and then Compile_Time_Known_Value
(Hi
)
10936 and then Compile_Time_Known_Value
(Lo
)
10939 D_Lov
: constant Ureal
:= Expr_Value_R
(Lo
);
10940 D_Hiv
: constant Ureal
:= Expr_Value_R
(Hi
);
10945 if Is_Real_Type
(Xtyp
) then
10946 S_Lov
:= Expr_Value_R
(S_Lo
);
10947 S_Hiv
:= Expr_Value_R
(S_Hi
);
10949 S_Lov
:= UR_From_Uint
(Expr_Value
(S_Lo
));
10950 S_Hiv
:= UR_From_Uint
(Expr_Value
(S_Hi
));
10954 and then S_Lov
>= D_Lov
10955 and then S_Hiv
<= D_Hiv
10957 -- Unset the range check flag on the current value of
10958 -- Expression (N), since the captured Operand may have
10959 -- been rewritten (such as for the case of a conversion
10960 -- to a fixed-point type).
10962 Set_Do_Range_Check
(Expression
(N
), False);
10970 -- For float to float conversions, we are done
10972 if Is_Floating_Point_Type
(Xtyp
)
10974 Is_Floating_Point_Type
(Btyp
)
10979 -- Otherwise rewrite the conversion as described above
10981 Conv
:= Relocate_Node
(N
);
10982 Rewrite
(Subtype_Mark
(Conv
), New_Occurrence_Of
(Btyp
, Loc
));
10983 Set_Etype
(Conv
, Btyp
);
10985 -- Enable overflow except for case of integer to float conversions,
10986 -- where it is never required, since we can never have overflow in
10989 if not Is_Integer_Type
(Etype
(Operand
)) then
10990 Enable_Overflow_Check
(Conv
);
10993 Tnn
:= Make_Temporary
(Loc
, 'T', Conv
);
10995 Insert_Actions
(N
, New_List
(
10996 Make_Object_Declaration
(Loc
,
10997 Defining_Identifier
=> Tnn
,
10998 Object_Definition
=> New_Occurrence_Of
(Btyp
, Loc
),
10999 Constant_Present
=> True,
11000 Expression
=> Conv
),
11002 Make_Raise_Constraint_Error
(Loc
,
11007 Left_Opnd
=> New_Occurrence_Of
(Tnn
, Loc
),
11009 Make_Attribute_Reference
(Loc
,
11010 Attribute_Name
=> Name_First
,
11012 New_Occurrence_Of
(Target_Type
, Loc
))),
11016 Left_Opnd
=> New_Occurrence_Of
(Tnn
, Loc
),
11018 Make_Attribute_Reference
(Loc
,
11019 Attribute_Name
=> Name_Last
,
11021 New_Occurrence_Of
(Target_Type
, Loc
)))),
11022 Reason
=> CE_Range_Check_Failed
)));
11024 Rewrite
(N
, New_Occurrence_Of
(Tnn
, Loc
));
11025 Analyze_And_Resolve
(N
, Btyp
);
11026 end Real_Range_Check
;
11028 -----------------------------
11029 -- Has_Extra_Accessibility --
11030 -----------------------------
11032 -- Returns true for a formal of an anonymous access type or for
11033 -- an Ada 2012-style stand-alone object of an anonymous access type.
11035 function Has_Extra_Accessibility
(Id
: Entity_Id
) return Boolean is
11037 if Is_Formal
(Id
) or else Ekind_In
(Id
, E_Constant
, E_Variable
) then
11038 return Present
(Effective_Extra_Accessibility
(Id
));
11042 end Has_Extra_Accessibility
;
11044 -- Start of processing for Expand_N_Type_Conversion
11047 -- First remove check marks put by the semantic analysis on the type
11048 -- conversion between array types. We need these checks, and they will
11049 -- be generated by this expansion routine, but we do not depend on these
11050 -- flags being set, and since we do intend to expand the checks in the
11051 -- front end, we don't want them on the tree passed to the back end.
11053 if Is_Array_Type
(Target_Type
) then
11054 if Is_Constrained
(Target_Type
) then
11055 Set_Do_Length_Check
(N
, False);
11057 Set_Do_Range_Check
(Operand
, False);
11061 -- Nothing at all to do if conversion is to the identical type so remove
11062 -- the conversion completely, it is useless, except that it may carry
11063 -- an Assignment_OK attribute, which must be propagated to the operand.
11065 if Operand_Type
= Target_Type
then
11066 if Assignment_OK
(N
) then
11067 Set_Assignment_OK
(Operand
);
11070 Rewrite
(N
, Relocate_Node
(Operand
));
11074 -- Nothing to do if this is the second argument of read. This is a
11075 -- "backwards" conversion that will be handled by the specialized code
11076 -- in attribute processing.
11078 if Nkind
(Parent
(N
)) = N_Attribute_Reference
11079 and then Attribute_Name
(Parent
(N
)) = Name_Read
11080 and then Next
(First
(Expressions
(Parent
(N
)))) = N
11085 -- Check for case of converting to a type that has an invariant
11086 -- associated with it. This requires an invariant check. We insert
11089 -- invariant_check (typ (expr))
11091 -- in the code, after removing side effects from the expression.
11092 -- This is clearer than replacing the conversion into an expression
11093 -- with actions, because the context may impose additional actions
11094 -- (tag checks, membership tests, etc.) that conflict with this
11095 -- rewriting (used previously).
11097 -- Note: the Comes_From_Source check, and then the resetting of this
11098 -- flag prevents what would otherwise be an infinite recursion.
11100 if Has_Invariants
(Target_Type
)
11101 and then Present
(Invariant_Procedure
(Target_Type
))
11102 and then Comes_From_Source
(N
)
11104 Set_Comes_From_Source
(N
, False);
11105 Remove_Side_Effects
(N
);
11106 Insert_Action
(N
, Make_Invariant_Call
(Duplicate_Subexpr
(N
)));
11110 -- Here if we may need to expand conversion
11112 -- If the operand of the type conversion is an arithmetic operation on
11113 -- signed integers, and the based type of the signed integer type in
11114 -- question is smaller than Standard.Integer, we promote both of the
11115 -- operands to type Integer.
11117 -- For example, if we have
11119 -- target-type (opnd1 + opnd2)
11121 -- and opnd1 and opnd2 are of type short integer, then we rewrite
11124 -- target-type (integer(opnd1) + integer(opnd2))
11126 -- We do this because we are always allowed to compute in a larger type
11127 -- if we do the right thing with the result, and in this case we are
11128 -- going to do a conversion which will do an appropriate check to make
11129 -- sure that things are in range of the target type in any case. This
11130 -- avoids some unnecessary intermediate overflows.
11132 -- We might consider a similar transformation in the case where the
11133 -- target is a real type or a 64-bit integer type, and the operand
11134 -- is an arithmetic operation using a 32-bit integer type. However,
11135 -- we do not bother with this case, because it could cause significant
11136 -- inefficiencies on 32-bit machines. On a 64-bit machine it would be
11137 -- much cheaper, but we don't want different behavior on 32-bit and
11138 -- 64-bit machines. Note that the exclusion of the 64-bit case also
11139 -- handles the configurable run-time cases where 64-bit arithmetic
11140 -- may simply be unavailable.
11142 -- Note: this circuit is partially redundant with respect to the circuit
11143 -- in Checks.Apply_Arithmetic_Overflow_Check, but we catch more cases in
11144 -- the processing here. Also we still need the Checks circuit, since we
11145 -- have to be sure not to generate junk overflow checks in the first
11146 -- place, since it would be trick to remove them here.
11148 if Integer_Promotion_Possible
(N
) then
11150 -- All conditions met, go ahead with transformation
11158 Make_Type_Conversion
(Loc
,
11159 Subtype_Mark
=> New_Occurrence_Of
(Standard_Integer
, Loc
),
11160 Expression
=> Relocate_Node
(Right_Opnd
(Operand
)));
11162 Opnd
:= New_Op_Node
(Nkind
(Operand
), Loc
);
11163 Set_Right_Opnd
(Opnd
, R
);
11165 if Nkind
(Operand
) in N_Binary_Op
then
11167 Make_Type_Conversion
(Loc
,
11168 Subtype_Mark
=> New_Occurrence_Of
(Standard_Integer
, Loc
),
11169 Expression
=> Relocate_Node
(Left_Opnd
(Operand
)));
11171 Set_Left_Opnd
(Opnd
, L
);
11175 Make_Type_Conversion
(Loc
,
11176 Subtype_Mark
=> Relocate_Node
(Subtype_Mark
(N
)),
11177 Expression
=> Opnd
));
11179 Analyze_And_Resolve
(N
, Target_Type
);
11184 -- Do validity check if validity checking operands
11186 if Validity_Checks_On
and Validity_Check_Operands
then
11187 Ensure_Valid
(Operand
);
11190 -- Special case of converting from non-standard boolean type
11192 if Is_Boolean_Type
(Operand_Type
)
11193 and then (Nonzero_Is_True
(Operand_Type
))
11195 Adjust_Condition
(Operand
);
11196 Set_Etype
(Operand
, Standard_Boolean
);
11197 Operand_Type
:= Standard_Boolean
;
11200 -- Case of converting to an access type
11202 if Is_Access_Type
(Target_Type
) then
11204 -- If this type conversion was internally generated by the front end
11205 -- to displace the pointer to the object to reference an interface
11206 -- type and the original node was an Unrestricted_Access attribute,
11207 -- then skip applying accessibility checks (because, according to the
11208 -- GNAT Reference Manual, this attribute is similar to 'Access except
11209 -- that all accessibility and aliased view checks are omitted).
11211 if not Comes_From_Source
(N
)
11212 and then Is_Interface
(Designated_Type
(Target_Type
))
11213 and then Nkind
(Original_Node
(N
)) = N_Attribute_Reference
11214 and then Attribute_Name
(Original_Node
(N
)) =
11215 Name_Unrestricted_Access
11219 -- Apply an accessibility check when the conversion operand is an
11220 -- access parameter (or a renaming thereof), unless conversion was
11221 -- expanded from an Unchecked_ or Unrestricted_Access attribute,
11222 -- or for the actual of a class-wide interface parameter. Note that
11223 -- other checks may still need to be applied below (such as tagged
11226 elsif Is_Entity_Name
(Operand
)
11227 and then Has_Extra_Accessibility
(Entity
(Operand
))
11228 and then Ekind
(Etype
(Operand
)) = E_Anonymous_Access_Type
11229 and then (Nkind
(Original_Node
(N
)) /= N_Attribute_Reference
11230 or else Attribute_Name
(Original_Node
(N
)) = Name_Access
)
11232 if not Comes_From_Source
(N
)
11233 and then Nkind_In
(Parent
(N
), N_Function_Call
,
11234 N_Procedure_Call_Statement
)
11235 and then Is_Interface
(Designated_Type
(Target_Type
))
11236 and then Is_Class_Wide_Type
(Designated_Type
(Target_Type
))
11241 Apply_Accessibility_Check
11242 (Operand
, Target_Type
, Insert_Node
=> Operand
);
11245 -- If the level of the operand type is statically deeper than the
11246 -- level of the target type, then force Program_Error. Note that this
11247 -- can only occur for cases where the attribute is within the body of
11248 -- an instantiation, otherwise the conversion will already have been
11249 -- rejected as illegal.
11251 -- Note: warnings are issued by the analyzer for the instance cases
11253 elsif In_Instance_Body
11255 -- The case where the target type is an anonymous access type of
11256 -- a discriminant is excluded, because the level of such a type
11257 -- depends on the context and currently the level returned for such
11258 -- types is zero, resulting in warnings about about check failures
11259 -- in certain legal cases involving class-wide interfaces as the
11260 -- designated type (some cases, such as return statements, are
11261 -- checked at run time, but not clear if these are handled right
11262 -- in general, see 3.10.2(12/2-12.5/3) ???).
11265 not (Ekind
(Target_Type
) = E_Anonymous_Access_Type
11266 and then Present
(Associated_Node_For_Itype
(Target_Type
))
11267 and then Nkind
(Associated_Node_For_Itype
(Target_Type
)) =
11268 N_Discriminant_Specification
)
11270 Type_Access_Level
(Operand_Type
) > Type_Access_Level
(Target_Type
)
11272 Raise_Accessibility_Error
;
11275 -- When the operand is a selected access discriminant the check needs
11276 -- to be made against the level of the object denoted by the prefix
11277 -- of the selected name. Force Program_Error for this case as well
11278 -- (this accessibility violation can only happen if within the body
11279 -- of an instantiation).
11281 elsif In_Instance_Body
11282 and then Ekind
(Operand_Type
) = E_Anonymous_Access_Type
11283 and then Nkind
(Operand
) = N_Selected_Component
11284 and then Ekind
(Entity
(Selector_Name
(Operand
))) = E_Discriminant
11285 and then Object_Access_Level
(Operand
) >
11286 Type_Access_Level
(Target_Type
)
11288 Raise_Accessibility_Error
;
11293 -- Case of conversions of tagged types and access to tagged types
11295 -- When needed, that is to say when the expression is class-wide, Add
11296 -- runtime a tag check for (strict) downward conversion by using the
11297 -- membership test, generating:
11299 -- [constraint_error when Operand not in Target_Type'Class]
11301 -- or in the access type case
11303 -- [constraint_error
11304 -- when Operand /= null
11305 -- and then Operand.all not in
11306 -- Designated_Type (Target_Type)'Class]
11308 if (Is_Access_Type
(Target_Type
)
11309 and then Is_Tagged_Type
(Designated_Type
(Target_Type
)))
11310 or else Is_Tagged_Type
(Target_Type
)
11312 -- Do not do any expansion in the access type case if the parent is a
11313 -- renaming, since this is an error situation which will be caught by
11314 -- Sem_Ch8, and the expansion can interfere with this error check.
11316 if Is_Access_Type
(Target_Type
) and then Is_Renamed_Object
(N
) then
11320 -- Otherwise, proceed with processing tagged conversion
11322 Tagged_Conversion
: declare
11323 Actual_Op_Typ
: Entity_Id
;
11324 Actual_Targ_Typ
: Entity_Id
;
11325 Make_Conversion
: Boolean := False;
11326 Root_Op_Typ
: Entity_Id
;
11328 procedure Make_Tag_Check
(Targ_Typ
: Entity_Id
);
11329 -- Create a membership check to test whether Operand is a member
11330 -- of Targ_Typ. If the original Target_Type is an access, include
11331 -- a test for null value. The check is inserted at N.
11333 --------------------
11334 -- Make_Tag_Check --
11335 --------------------
11337 procedure Make_Tag_Check
(Targ_Typ
: Entity_Id
) is
11342 -- [Constraint_Error
11343 -- when Operand /= null
11344 -- and then Operand.all not in Targ_Typ]
11346 if Is_Access_Type
(Target_Type
) then
11348 Make_And_Then
(Loc
,
11351 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Operand
),
11352 Right_Opnd
=> Make_Null
(Loc
)),
11357 Make_Explicit_Dereference
(Loc
,
11358 Prefix
=> Duplicate_Subexpr_No_Checks
(Operand
)),
11359 Right_Opnd
=> New_Occurrence_Of
(Targ_Typ
, Loc
)));
11362 -- [Constraint_Error when Operand not in Targ_Typ]
11367 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Operand
),
11368 Right_Opnd
=> New_Occurrence_Of
(Targ_Typ
, Loc
));
11372 Make_Raise_Constraint_Error
(Loc
,
11374 Reason
=> CE_Tag_Check_Failed
),
11375 Suppress
=> All_Checks
);
11376 end Make_Tag_Check
;
11378 -- Start of processing for Tagged_Conversion
11381 -- Handle entities from the limited view
11383 if Is_Access_Type
(Operand_Type
) then
11385 Available_View
(Designated_Type
(Operand_Type
));
11387 Actual_Op_Typ
:= Operand_Type
;
11390 if Is_Access_Type
(Target_Type
) then
11392 Available_View
(Designated_Type
(Target_Type
));
11394 Actual_Targ_Typ
:= Target_Type
;
11397 Root_Op_Typ
:= Root_Type
(Actual_Op_Typ
);
11399 -- Ada 2005 (AI-251): Handle interface type conversion
11401 if Is_Interface
(Actual_Op_Typ
)
11403 Is_Interface
(Actual_Targ_Typ
)
11405 Expand_Interface_Conversion
(N
);
11409 if not Tag_Checks_Suppressed
(Actual_Targ_Typ
) then
11411 -- Create a runtime tag check for a downward class-wide type
11414 if Is_Class_Wide_Type
(Actual_Op_Typ
)
11415 and then Actual_Op_Typ
/= Actual_Targ_Typ
11416 and then Root_Op_Typ
/= Actual_Targ_Typ
11417 and then Is_Ancestor
(Root_Op_Typ
, Actual_Targ_Typ
,
11418 Use_Full_View
=> True)
11420 Make_Tag_Check
(Class_Wide_Type
(Actual_Targ_Typ
));
11421 Make_Conversion
:= True;
11424 -- AI05-0073: If the result subtype of the function is defined
11425 -- by an access_definition designating a specific tagged type
11426 -- T, a check is made that the result value is null or the tag
11427 -- of the object designated by the result value identifies T.
11428 -- Constraint_Error is raised if this check fails.
11430 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
then
11433 Func_Typ
: Entity_Id
;
11436 -- Climb scope stack looking for the enclosing function
11438 Func
:= Current_Scope
;
11439 while Present
(Func
)
11440 and then Ekind
(Func
) /= E_Function
11442 Func
:= Scope
(Func
);
11445 -- The function's return subtype must be defined using
11446 -- an access definition.
11448 if Nkind
(Result_Definition
(Parent
(Func
))) =
11449 N_Access_Definition
11451 Func_Typ
:= Directly_Designated_Type
(Etype
(Func
));
11453 -- The return subtype denotes a specific tagged type,
11454 -- in other words, a non class-wide type.
11456 if Is_Tagged_Type
(Func_Typ
)
11457 and then not Is_Class_Wide_Type
(Func_Typ
)
11459 Make_Tag_Check
(Actual_Targ_Typ
);
11460 Make_Conversion
:= True;
11466 -- We have generated a tag check for either a class-wide type
11467 -- conversion or for AI05-0073.
11469 if Make_Conversion
then
11474 Make_Unchecked_Type_Conversion
(Loc
,
11475 Subtype_Mark
=> New_Occurrence_Of
(Target_Type
, Loc
),
11476 Expression
=> Relocate_Node
(Expression
(N
)));
11478 Analyze_And_Resolve
(N
, Target_Type
);
11482 end Tagged_Conversion
;
11484 -- Case of other access type conversions
11486 elsif Is_Access_Type
(Target_Type
) then
11487 Apply_Constraint_Check
(Operand
, Target_Type
);
11489 -- Case of conversions from a fixed-point type
11491 -- These conversions require special expansion and processing, found in
11492 -- the Exp_Fixd package. We ignore cases where Conversion_OK is set,
11493 -- since from a semantic point of view, these are simple integer
11494 -- conversions, which do not need further processing.
11496 elsif Is_Fixed_Point_Type
(Operand_Type
)
11497 and then not Conversion_OK
(N
)
11499 -- We should never see universal fixed at this case, since the
11500 -- expansion of the constituent divide or multiply should have
11501 -- eliminated the explicit mention of universal fixed.
11503 pragma Assert
(Operand_Type
/= Universal_Fixed
);
11505 -- Check for special case of the conversion to universal real that
11506 -- occurs as a result of the use of a round attribute. In this case,
11507 -- the real type for the conversion is taken from the target type of
11508 -- the Round attribute and the result must be marked as rounded.
11510 if Target_Type
= Universal_Real
11511 and then Nkind
(Parent
(N
)) = N_Attribute_Reference
11512 and then Attribute_Name
(Parent
(N
)) = Name_Round
11514 Set_Rounded_Result
(N
);
11515 Set_Etype
(N
, Etype
(Parent
(N
)));
11518 -- Otherwise do correct fixed-conversion, but skip these if the
11519 -- Conversion_OK flag is set, because from a semantic point of view
11520 -- these are simple integer conversions needing no further processing
11521 -- (the backend will simply treat them as integers).
11523 if not Conversion_OK
(N
) then
11524 if Is_Fixed_Point_Type
(Etype
(N
)) then
11525 Expand_Convert_Fixed_To_Fixed
(N
);
11528 elsif Is_Integer_Type
(Etype
(N
)) then
11529 Expand_Convert_Fixed_To_Integer
(N
);
11532 pragma Assert
(Is_Floating_Point_Type
(Etype
(N
)));
11533 Expand_Convert_Fixed_To_Float
(N
);
11538 -- Case of conversions to a fixed-point type
11540 -- These conversions require special expansion and processing, found in
11541 -- the Exp_Fixd package. Again, ignore cases where Conversion_OK is set,
11542 -- since from a semantic point of view, these are simple integer
11543 -- conversions, which do not need further processing.
11545 elsif Is_Fixed_Point_Type
(Target_Type
)
11546 and then not Conversion_OK
(N
)
11548 if Is_Integer_Type
(Operand_Type
) then
11549 Expand_Convert_Integer_To_Fixed
(N
);
11552 pragma Assert
(Is_Floating_Point_Type
(Operand_Type
));
11553 Expand_Convert_Float_To_Fixed
(N
);
11557 -- Case of float-to-integer conversions
11559 -- We also handle float-to-fixed conversions with Conversion_OK set
11560 -- since semantically the fixed-point target is treated as though it
11561 -- were an integer in such cases.
11563 elsif Is_Floating_Point_Type
(Operand_Type
)
11565 (Is_Integer_Type
(Target_Type
)
11567 (Is_Fixed_Point_Type
(Target_Type
) and then Conversion_OK
(N
)))
11569 -- One more check here, gcc is still not able to do conversions of
11570 -- this type with proper overflow checking, and so gigi is doing an
11571 -- approximation of what is required by doing floating-point compares
11572 -- with the end-point. But that can lose precision in some cases, and
11573 -- give a wrong result. Converting the operand to Universal_Real is
11574 -- helpful, but still does not catch all cases with 64-bit integers
11575 -- on targets with only 64-bit floats.
11577 -- The above comment seems obsoleted by Apply_Float_Conversion_Check
11578 -- Can this code be removed ???
11580 if Do_Range_Check
(Operand
) then
11582 Make_Type_Conversion
(Loc
,
11584 New_Occurrence_Of
(Universal_Real
, Loc
),
11586 Relocate_Node
(Operand
)));
11588 Set_Etype
(Operand
, Universal_Real
);
11589 Enable_Range_Check
(Operand
);
11590 Set_Do_Range_Check
(Expression
(Operand
), False);
11593 -- Case of array conversions
11595 -- Expansion of array conversions, add required length/range checks but
11596 -- only do this if there is no change of representation. For handling of
11597 -- this case, see Handle_Changed_Representation.
11599 elsif Is_Array_Type
(Target_Type
) then
11600 if Is_Constrained
(Target_Type
) then
11601 Apply_Length_Check
(Operand
, Target_Type
);
11603 Apply_Range_Check
(Operand
, Target_Type
);
11606 Handle_Changed_Representation
;
11608 -- Case of conversions of discriminated types
11610 -- Add required discriminant checks if target is constrained. Again this
11611 -- change is skipped if we have a change of representation.
11613 elsif Has_Discriminants
(Target_Type
)
11614 and then Is_Constrained
(Target_Type
)
11616 Apply_Discriminant_Check
(Operand
, Target_Type
);
11617 Handle_Changed_Representation
;
11619 -- Case of all other record conversions. The only processing required
11620 -- is to check for a change of representation requiring the special
11621 -- assignment processing.
11623 elsif Is_Record_Type
(Target_Type
) then
11625 -- Ada 2005 (AI-216): Program_Error is raised when converting from
11626 -- a derived Unchecked_Union type to an unconstrained type that is
11627 -- not Unchecked_Union if the operand lacks inferable discriminants.
11629 if Is_Derived_Type
(Operand_Type
)
11630 and then Is_Unchecked_Union
(Base_Type
(Operand_Type
))
11631 and then not Is_Constrained
(Target_Type
)
11632 and then not Is_Unchecked_Union
(Base_Type
(Target_Type
))
11633 and then not Has_Inferable_Discriminants
(Operand
)
11635 -- To prevent Gigi from generating illegal code, we generate a
11636 -- Program_Error node, but we give it the target type of the
11637 -- conversion (is this requirement documented somewhere ???)
11640 PE
: constant Node_Id
:= Make_Raise_Program_Error
(Loc
,
11641 Reason
=> PE_Unchecked_Union_Restriction
);
11644 Set_Etype
(PE
, Target_Type
);
11649 Handle_Changed_Representation
;
11652 -- Case of conversions of enumeration types
11654 elsif Is_Enumeration_Type
(Target_Type
) then
11656 -- Special processing is required if there is a change of
11657 -- representation (from enumeration representation clauses).
11659 if not Same_Representation
(Target_Type
, Operand_Type
) then
11661 -- Convert: x(y) to x'val (ytyp'val (y))
11664 Make_Attribute_Reference
(Loc
,
11665 Prefix
=> New_Occurrence_Of
(Target_Type
, Loc
),
11666 Attribute_Name
=> Name_Val
,
11667 Expressions
=> New_List
(
11668 Make_Attribute_Reference
(Loc
,
11669 Prefix
=> New_Occurrence_Of
(Operand_Type
, Loc
),
11670 Attribute_Name
=> Name_Pos
,
11671 Expressions
=> New_List
(Operand
)))));
11673 Analyze_And_Resolve
(N
, Target_Type
);
11676 -- Case of conversions to floating-point
11678 elsif Is_Floating_Point_Type
(Target_Type
) then
11682 -- At this stage, either the conversion node has been transformed into
11683 -- some other equivalent expression, or left as a conversion that can be
11684 -- handled by Gigi, in the following cases:
11686 -- Conversions with no change of representation or type
11688 -- Numeric conversions involving integer, floating- and fixed-point
11689 -- values. Fixed-point values are allowed only if Conversion_OK is
11690 -- set, i.e. if the fixed-point values are to be treated as integers.
11692 -- No other conversions should be passed to Gigi
11694 -- Check: are these rules stated in sinfo??? if so, why restate here???
11696 -- The only remaining step is to generate a range check if we still have
11697 -- a type conversion at this stage and Do_Range_Check is set. For now we
11698 -- do this only for conversions of discrete types and for float-to-float
11701 if Nkind
(N
) = N_Type_Conversion
then
11703 -- For now we only support floating-point cases where both source
11704 -- and target are floating-point types. Conversions where the source
11705 -- and target involve integer or fixed-point types are still TBD,
11706 -- though not clear whether those can even happen at this point, due
11707 -- to transformations above. ???
11709 if Is_Floating_Point_Type
(Etype
(N
))
11710 and then Is_Floating_Point_Type
(Etype
(Expression
(N
)))
11712 if Do_Range_Check
(Expression
(N
))
11713 and then Is_Floating_Point_Type
(Target_Type
)
11715 Generate_Range_Check
11716 (Expression
(N
), Target_Type
, CE_Range_Check_Failed
);
11719 -- Discrete-to-discrete conversions
11721 elsif Is_Discrete_Type
(Etype
(N
)) then
11723 Expr
: constant Node_Id
:= Expression
(N
);
11728 if Do_Range_Check
(Expr
)
11729 and then Is_Discrete_Type
(Etype
(Expr
))
11731 Set_Do_Range_Check
(Expr
, False);
11733 -- Before we do a range check, we have to deal with treating
11734 -- a fixed-point operand as an integer. The way we do this
11735 -- is simply to do an unchecked conversion to an appropriate
11736 -- integer type large enough to hold the result.
11738 -- This code is not active yet, because we are only dealing
11739 -- with discrete types so far ???
11741 if Nkind
(Expr
) in N_Has_Treat_Fixed_As_Integer
11742 and then Treat_Fixed_As_Integer
(Expr
)
11744 Ftyp
:= Base_Type
(Etype
(Expr
));
11746 if Esize
(Ftyp
) >= Esize
(Standard_Integer
) then
11747 Ityp
:= Standard_Long_Long_Integer
;
11749 Ityp
:= Standard_Integer
;
11752 Rewrite
(Expr
, Unchecked_Convert_To
(Ityp
, Expr
));
11755 -- Reset overflow flag, since the range check will include
11756 -- dealing with possible overflow, and generate the check.
11757 -- If Address is either a source type or target type,
11758 -- suppress range check to avoid typing anomalies when
11759 -- it is a visible integer type.
11761 Set_Do_Overflow_Check
(N
, False);
11763 if not Is_Descendant_Of_Address
(Etype
(Expr
))
11764 and then not Is_Descendant_Of_Address
(Target_Type
)
11766 Generate_Range_Check
11767 (Expr
, Target_Type
, CE_Range_Check_Failed
);
11774 -- Here at end of processing
11777 -- Apply predicate check if required. Note that we can't just call
11778 -- Apply_Predicate_Check here, because the type looks right after
11779 -- the conversion and it would omit the check. The Comes_From_Source
11780 -- guard is necessary to prevent infinite recursions when we generate
11781 -- internal conversions for the purpose of checking predicates.
11783 if Present
(Predicate_Function
(Target_Type
))
11784 and then not Predicates_Ignored
(Target_Type
)
11785 and then Target_Type
/= Operand_Type
11786 and then Comes_From_Source
(N
)
11789 New_Expr
: constant Node_Id
:= Duplicate_Subexpr
(N
);
11792 -- Avoid infinite recursion on the subsequent expansion of
11793 -- of the copy of the original type conversion.
11795 Set_Comes_From_Source
(New_Expr
, False);
11796 Insert_Action
(N
, Make_Predicate_Check
(Target_Type
, New_Expr
));
11799 end Expand_N_Type_Conversion
;
11801 -----------------------------------
11802 -- Expand_N_Unchecked_Expression --
11803 -----------------------------------
11805 -- Remove the unchecked expression node from the tree. Its job was simply
11806 -- to make sure that its constituent expression was handled with checks
11807 -- off, and now that that is done, we can remove it from the tree, and
11808 -- indeed must, since Gigi does not expect to see these nodes.
11810 procedure Expand_N_Unchecked_Expression
(N
: Node_Id
) is
11811 Exp
: constant Node_Id
:= Expression
(N
);
11813 Set_Assignment_OK
(Exp
, Assignment_OK
(N
) or else Assignment_OK
(Exp
));
11815 end Expand_N_Unchecked_Expression
;
11817 ----------------------------------------
11818 -- Expand_N_Unchecked_Type_Conversion --
11819 ----------------------------------------
11821 -- If this cannot be handled by Gigi and we haven't already made a
11822 -- temporary for it, do it now.
11824 procedure Expand_N_Unchecked_Type_Conversion
(N
: Node_Id
) is
11825 Target_Type
: constant Entity_Id
:= Etype
(N
);
11826 Operand
: constant Node_Id
:= Expression
(N
);
11827 Operand_Type
: constant Entity_Id
:= Etype
(Operand
);
11830 -- Nothing at all to do if conversion is to the identical type so remove
11831 -- the conversion completely, it is useless, except that it may carry
11832 -- an Assignment_OK indication which must be propagated to the operand.
11834 if Operand_Type
= Target_Type
then
11836 -- Code duplicates Expand_N_Unchecked_Expression above, factor???
11838 if Assignment_OK
(N
) then
11839 Set_Assignment_OK
(Operand
);
11842 Rewrite
(N
, Relocate_Node
(Operand
));
11846 -- If we have a conversion of a compile time known value to a target
11847 -- type and the value is in range of the target type, then we can simply
11848 -- replace the construct by an integer literal of the correct type. We
11849 -- only apply this to integer types being converted. Possibly it may
11850 -- apply in other cases, but it is too much trouble to worry about.
11852 -- Note that we do not do this transformation if the Kill_Range_Check
11853 -- flag is set, since then the value may be outside the expected range.
11854 -- This happens in the Normalize_Scalars case.
11856 -- We also skip this if either the target or operand type is biased
11857 -- because in this case, the unchecked conversion is supposed to
11858 -- preserve the bit pattern, not the integer value.
11860 if Is_Integer_Type
(Target_Type
)
11861 and then not Has_Biased_Representation
(Target_Type
)
11862 and then Is_Integer_Type
(Operand_Type
)
11863 and then not Has_Biased_Representation
(Operand_Type
)
11864 and then Compile_Time_Known_Value
(Operand
)
11865 and then not Kill_Range_Check
(N
)
11868 Val
: constant Uint
:= Expr_Value
(Operand
);
11871 if Compile_Time_Known_Value
(Type_Low_Bound
(Target_Type
))
11873 Compile_Time_Known_Value
(Type_High_Bound
(Target_Type
))
11875 Val
>= Expr_Value
(Type_Low_Bound
(Target_Type
))
11877 Val
<= Expr_Value
(Type_High_Bound
(Target_Type
))
11879 Rewrite
(N
, Make_Integer_Literal
(Sloc
(N
), Val
));
11881 -- If Address is the target type, just set the type to avoid a
11882 -- spurious type error on the literal when Address is a visible
11885 if Is_Descendant_Of_Address
(Target_Type
) then
11886 Set_Etype
(N
, Target_Type
);
11888 Analyze_And_Resolve
(N
, Target_Type
);
11896 -- Nothing to do if conversion is safe
11898 if Safe_Unchecked_Type_Conversion
(N
) then
11902 -- Otherwise force evaluation unless Assignment_OK flag is set (this
11903 -- flag indicates ??? More comments needed here)
11905 if Assignment_OK
(N
) then
11908 Force_Evaluation
(N
);
11910 end Expand_N_Unchecked_Type_Conversion
;
11912 ----------------------------
11913 -- Expand_Record_Equality --
11914 ----------------------------
11916 -- For non-variant records, Equality is expanded when needed into:
11918 -- and then Lhs.Discr1 = Rhs.Discr1
11920 -- and then Lhs.Discrn = Rhs.Discrn
11921 -- and then Lhs.Cmp1 = Rhs.Cmp1
11923 -- and then Lhs.Cmpn = Rhs.Cmpn
11925 -- The expression is folded by the back end for adjacent fields. This
11926 -- function is called for tagged record in only one occasion: for imple-
11927 -- menting predefined primitive equality (see Predefined_Primitives_Bodies)
11928 -- otherwise the primitive "=" is used directly.
11930 function Expand_Record_Equality
11935 Bodies
: List_Id
) return Node_Id
11937 Loc
: constant Source_Ptr
:= Sloc
(Nod
);
11942 First_Time
: Boolean := True;
11944 function Element_To_Compare
(C
: Entity_Id
) return Entity_Id
;
11945 -- Return the next discriminant or component to compare, starting with
11946 -- C, skipping inherited components.
11948 ------------------------
11949 -- Element_To_Compare --
11950 ------------------------
11952 function Element_To_Compare
(C
: Entity_Id
) return Entity_Id
is
11958 -- Exit loop when the next element to be compared is found, or
11959 -- there is no more such element.
11961 exit when No
(Comp
);
11963 exit when Ekind_In
(Comp
, E_Discriminant
, E_Component
)
11966 -- Skip inherited components
11968 -- Note: for a tagged type, we always generate the "=" primitive
11969 -- for the base type (not on the first subtype), so the test for
11970 -- Comp /= Original_Record_Component (Comp) is True for
11971 -- inherited components only.
11973 (Is_Tagged_Type
(Typ
)
11974 and then Comp
/= Original_Record_Component
(Comp
))
11978 or else Chars
(Comp
) = Name_uTag
11980 -- Skip interface elements (secondary tags???)
11982 or else Is_Interface
(Etype
(Comp
)));
11984 Next_Entity
(Comp
);
11988 end Element_To_Compare
;
11990 -- Start of processing for Expand_Record_Equality
11993 -- Generates the following code: (assuming that Typ has one Discr and
11994 -- component C2 is also a record)
11997 -- and then Lhs.Discr1 = Rhs.Discr1
11998 -- and then Lhs.C1 = Rhs.C1
11999 -- and then Lhs.C2.C1=Rhs.C2.C1 and then ... Lhs.C2.Cn=Rhs.C2.Cn
12001 -- and then Lhs.Cmpn = Rhs.Cmpn
12003 Result
:= New_Occurrence_Of
(Standard_True
, Loc
);
12004 C
:= Element_To_Compare
(First_Entity
(Typ
));
12005 while Present
(C
) loop
12013 First_Time
:= False;
12017 New_Lhs
:= New_Copy_Tree
(Lhs
);
12018 New_Rhs
:= New_Copy_Tree
(Rhs
);
12022 Expand_Composite_Equality
(Nod
, Etype
(C
),
12024 Make_Selected_Component
(Loc
,
12026 Selector_Name
=> New_Occurrence_Of
(C
, Loc
)),
12028 Make_Selected_Component
(Loc
,
12030 Selector_Name
=> New_Occurrence_Of
(C
, Loc
)),
12033 -- If some (sub)component is an unchecked_union, the whole
12034 -- operation will raise program error.
12036 if Nkind
(Check
) = N_Raise_Program_Error
then
12038 Set_Etype
(Result
, Standard_Boolean
);
12042 Make_And_Then
(Loc
,
12043 Left_Opnd
=> Result
,
12044 Right_Opnd
=> Check
);
12048 C
:= Element_To_Compare
(Next_Entity
(C
));
12052 end Expand_Record_Equality
;
12054 ---------------------------
12055 -- Expand_Set_Membership --
12056 ---------------------------
12058 procedure Expand_Set_Membership
(N
: Node_Id
) is
12059 Lop
: constant Node_Id
:= Left_Opnd
(N
);
12063 function Make_Cond
(Alt
: Node_Id
) return Node_Id
;
12064 -- If the alternative is a subtype mark, create a simple membership
12065 -- test. Otherwise create an equality test for it.
12071 function Make_Cond
(Alt
: Node_Id
) return Node_Id
is
12073 L
: constant Node_Id
:= New_Copy
(Lop
);
12074 R
: constant Node_Id
:= Relocate_Node
(Alt
);
12077 if (Is_Entity_Name
(Alt
) and then Is_Type
(Entity
(Alt
)))
12078 or else Nkind
(Alt
) = N_Range
12081 Make_In
(Sloc
(Alt
),
12086 Make_Op_Eq
(Sloc
(Alt
),
12094 -- Start of processing for Expand_Set_Membership
12097 Remove_Side_Effects
(Lop
);
12099 Alt
:= Last
(Alternatives
(N
));
12100 Res
:= Make_Cond
(Alt
);
12103 while Present
(Alt
) loop
12105 Make_Or_Else
(Sloc
(Alt
),
12106 Left_Opnd
=> Make_Cond
(Alt
),
12107 Right_Opnd
=> Res
);
12112 Analyze_And_Resolve
(N
, Standard_Boolean
);
12113 end Expand_Set_Membership
;
12115 -----------------------------------
12116 -- Expand_Short_Circuit_Operator --
12117 -----------------------------------
12119 -- Deal with special expansion if actions are present for the right operand
12120 -- and deal with optimizing case of arguments being True or False. We also
12121 -- deal with the special case of non-standard boolean values.
12123 procedure Expand_Short_Circuit_Operator
(N
: Node_Id
) is
12124 Loc
: constant Source_Ptr
:= Sloc
(N
);
12125 Typ
: constant Entity_Id
:= Etype
(N
);
12126 Left
: constant Node_Id
:= Left_Opnd
(N
);
12127 Right
: constant Node_Id
:= Right_Opnd
(N
);
12128 LocR
: constant Source_Ptr
:= Sloc
(Right
);
12131 Shortcut_Value
: constant Boolean := Nkind
(N
) = N_Or_Else
;
12132 Shortcut_Ent
: constant Entity_Id
:= Boolean_Literals
(Shortcut_Value
);
12133 -- If Left = Shortcut_Value then Right need not be evaluated
12135 function Make_Test_Expr
(Opnd
: Node_Id
) return Node_Id
;
12136 -- For Opnd a boolean expression, return a Boolean expression equivalent
12137 -- to Opnd /= Shortcut_Value.
12139 --------------------
12140 -- Make_Test_Expr --
12141 --------------------
12143 function Make_Test_Expr
(Opnd
: Node_Id
) return Node_Id
is
12145 if Shortcut_Value
then
12146 return Make_Op_Not
(Sloc
(Opnd
), Opnd
);
12150 end Make_Test_Expr
;
12154 Op_Var
: Entity_Id
;
12155 -- Entity for a temporary variable holding the value of the operator,
12156 -- used for expansion in the case where actions are present.
12158 -- Start of processing for Expand_Short_Circuit_Operator
12161 -- Deal with non-standard booleans
12163 if Is_Boolean_Type
(Typ
) then
12164 Adjust_Condition
(Left
);
12165 Adjust_Condition
(Right
);
12166 Set_Etype
(N
, Standard_Boolean
);
12169 -- Check for cases where left argument is known to be True or False
12171 if Compile_Time_Known_Value
(Left
) then
12173 -- Mark SCO for left condition as compile time known
12175 if Generate_SCO
and then Comes_From_Source
(Left
) then
12176 Set_SCO_Condition
(Left
, Expr_Value_E
(Left
) = Standard_True
);
12179 -- Rewrite True AND THEN Right / False OR ELSE Right to Right.
12180 -- Any actions associated with Right will be executed unconditionally
12181 -- and can thus be inserted into the tree unconditionally.
12183 if Expr_Value_E
(Left
) /= Shortcut_Ent
then
12184 if Present
(Actions
(N
)) then
12185 Insert_Actions
(N
, Actions
(N
));
12188 Rewrite
(N
, Right
);
12190 -- Rewrite False AND THEN Right / True OR ELSE Right to Left.
12191 -- In this case we can forget the actions associated with Right,
12192 -- since they will never be executed.
12195 Kill_Dead_Code
(Right
);
12196 Kill_Dead_Code
(Actions
(N
));
12197 Rewrite
(N
, New_Occurrence_Of
(Shortcut_Ent
, Loc
));
12200 Adjust_Result_Type
(N
, Typ
);
12204 -- If Actions are present for the right operand, we have to do some
12205 -- special processing. We can't just let these actions filter back into
12206 -- code preceding the short circuit (which is what would have happened
12207 -- if we had not trapped them in the short-circuit form), since they
12208 -- must only be executed if the right operand of the short circuit is
12209 -- executed and not otherwise.
12211 if Present
(Actions
(N
)) then
12212 Actlist
:= Actions
(N
);
12214 -- The old approach is to expand:
12216 -- left AND THEN right
12220 -- C : Boolean := False;
12228 -- and finally rewrite the operator into a reference to C. Similarly
12229 -- for left OR ELSE right, with negated values. Note that this
12230 -- rewrite causes some difficulties for coverage analysis because
12231 -- of the introduction of the new variable C, which obscures the
12232 -- structure of the test.
12234 -- We use this "old approach" if Minimize_Expression_With_Actions
12237 if Minimize_Expression_With_Actions
then
12238 Op_Var
:= Make_Temporary
(Loc
, 'C', Related_Node
=> N
);
12241 Make_Object_Declaration
(Loc
,
12242 Defining_Identifier
=> Op_Var
,
12243 Object_Definition
=>
12244 New_Occurrence_Of
(Standard_Boolean
, Loc
),
12246 New_Occurrence_Of
(Shortcut_Ent
, Loc
)));
12248 Append_To
(Actlist
,
12249 Make_Implicit_If_Statement
(Right
,
12250 Condition
=> Make_Test_Expr
(Right
),
12251 Then_Statements
=> New_List
(
12252 Make_Assignment_Statement
(LocR
,
12253 Name
=> New_Occurrence_Of
(Op_Var
, LocR
),
12256 (Boolean_Literals
(not Shortcut_Value
), LocR
)))));
12259 Make_Implicit_If_Statement
(Left
,
12260 Condition
=> Make_Test_Expr
(Left
),
12261 Then_Statements
=> Actlist
));
12263 Rewrite
(N
, New_Occurrence_Of
(Op_Var
, Loc
));
12264 Analyze_And_Resolve
(N
, Standard_Boolean
);
12266 -- The new approach (the default) is to use an
12267 -- Expression_With_Actions node for the right operand of the
12268 -- short-circuit form. Note that this solves the traceability
12269 -- problems for coverage analysis.
12273 Make_Expression_With_Actions
(LocR
,
12274 Expression
=> Relocate_Node
(Right
),
12275 Actions
=> Actlist
));
12277 Set_Actions
(N
, No_List
);
12278 Analyze_And_Resolve
(Right
, Standard_Boolean
);
12281 Adjust_Result_Type
(N
, Typ
);
12285 -- No actions present, check for cases of right argument True/False
12287 if Compile_Time_Known_Value
(Right
) then
12289 -- Mark SCO for left condition as compile time known
12291 if Generate_SCO
and then Comes_From_Source
(Right
) then
12292 Set_SCO_Condition
(Right
, Expr_Value_E
(Right
) = Standard_True
);
12295 -- Change (Left and then True), (Left or else False) to Left. Note
12296 -- that we know there are no actions associated with the right
12297 -- operand, since we just checked for this case above.
12299 if Expr_Value_E
(Right
) /= Shortcut_Ent
then
12302 -- Change (Left and then False), (Left or else True) to Right,
12303 -- making sure to preserve any side effects associated with the Left
12307 Remove_Side_Effects
(Left
);
12308 Rewrite
(N
, New_Occurrence_Of
(Shortcut_Ent
, Loc
));
12312 Adjust_Result_Type
(N
, Typ
);
12313 end Expand_Short_Circuit_Operator
;
12315 -------------------------------------
12316 -- Fixup_Universal_Fixed_Operation --
12317 -------------------------------------
12319 procedure Fixup_Universal_Fixed_Operation
(N
: Node_Id
) is
12320 Conv
: constant Node_Id
:= Parent
(N
);
12323 -- We must have a type conversion immediately above us
12325 pragma Assert
(Nkind
(Conv
) = N_Type_Conversion
);
12327 -- Normally the type conversion gives our target type. The exception
12328 -- occurs in the case of the Round attribute, where the conversion
12329 -- will be to universal real, and our real type comes from the Round
12330 -- attribute (as well as an indication that we must round the result)
12332 if Nkind
(Parent
(Conv
)) = N_Attribute_Reference
12333 and then Attribute_Name
(Parent
(Conv
)) = Name_Round
12335 Set_Etype
(N
, Etype
(Parent
(Conv
)));
12336 Set_Rounded_Result
(N
);
12338 -- Normal case where type comes from conversion above us
12341 Set_Etype
(N
, Etype
(Conv
));
12343 end Fixup_Universal_Fixed_Operation
;
12345 ---------------------------------
12346 -- Has_Inferable_Discriminants --
12347 ---------------------------------
12349 function Has_Inferable_Discriminants
(N
: Node_Id
) return Boolean is
12351 function Prefix_Is_Formal_Parameter
(N
: Node_Id
) return Boolean;
12352 -- Determines whether the left-most prefix of a selected component is a
12353 -- formal parameter in a subprogram. Assumes N is a selected component.
12355 --------------------------------
12356 -- Prefix_Is_Formal_Parameter --
12357 --------------------------------
12359 function Prefix_Is_Formal_Parameter
(N
: Node_Id
) return Boolean is
12360 Sel_Comp
: Node_Id
;
12363 -- Move to the left-most prefix by climbing up the tree
12366 while Present
(Parent
(Sel_Comp
))
12367 and then Nkind
(Parent
(Sel_Comp
)) = N_Selected_Component
12369 Sel_Comp
:= Parent
(Sel_Comp
);
12372 return Ekind
(Entity
(Prefix
(Sel_Comp
))) in Formal_Kind
;
12373 end Prefix_Is_Formal_Parameter
;
12375 -- Start of processing for Has_Inferable_Discriminants
12378 -- For selected components, the subtype of the selector must be a
12379 -- constrained Unchecked_Union. If the component is subject to a
12380 -- per-object constraint, then the enclosing object must have inferable
12383 if Nkind
(N
) = N_Selected_Component
then
12384 if Has_Per_Object_Constraint
(Entity
(Selector_Name
(N
))) then
12386 -- A small hack. If we have a per-object constrained selected
12387 -- component of a formal parameter, return True since we do not
12388 -- know the actual parameter association yet.
12390 if Prefix_Is_Formal_Parameter
(N
) then
12393 -- Otherwise, check the enclosing object and the selector
12396 return Has_Inferable_Discriminants
(Prefix
(N
))
12397 and then Has_Inferable_Discriminants
(Selector_Name
(N
));
12400 -- The call to Has_Inferable_Discriminants will determine whether
12401 -- the selector has a constrained Unchecked_Union nominal type.
12404 return Has_Inferable_Discriminants
(Selector_Name
(N
));
12407 -- A qualified expression has inferable discriminants if its subtype
12408 -- mark is a constrained Unchecked_Union subtype.
12410 elsif Nkind
(N
) = N_Qualified_Expression
then
12411 return Is_Unchecked_Union
(Etype
(Subtype_Mark
(N
)))
12412 and then Is_Constrained
(Etype
(Subtype_Mark
(N
)));
12414 -- For all other names, it is sufficient to have a constrained
12415 -- Unchecked_Union nominal subtype.
12418 return Is_Unchecked_Union
(Base_Type
(Etype
(N
)))
12419 and then Is_Constrained
(Etype
(N
));
12421 end Has_Inferable_Discriminants
;
12423 -------------------------------
12424 -- Insert_Dereference_Action --
12425 -------------------------------
12427 procedure Insert_Dereference_Action
(N
: Node_Id
) is
12428 function Is_Checked_Storage_Pool
(P
: Entity_Id
) return Boolean;
12429 -- Return true if type of P is derived from Checked_Pool;
12431 -----------------------------
12432 -- Is_Checked_Storage_Pool --
12433 -----------------------------
12435 function Is_Checked_Storage_Pool
(P
: Entity_Id
) return Boolean is
12444 while T
/= Etype
(T
) loop
12445 if Is_RTE
(T
, RE_Checked_Pool
) then
12453 end Is_Checked_Storage_Pool
;
12457 Context
: constant Node_Id
:= Parent
(N
);
12458 Ptr_Typ
: constant Entity_Id
:= Etype
(N
);
12459 Desig_Typ
: constant Entity_Id
:=
12460 Available_View
(Designated_Type
(Ptr_Typ
));
12461 Loc
: constant Source_Ptr
:= Sloc
(N
);
12462 Pool
: constant Entity_Id
:= Associated_Storage_Pool
(Ptr_Typ
);
12468 Size_Bits
: Node_Id
;
12471 -- Start of processing for Insert_Dereference_Action
12474 pragma Assert
(Nkind
(Context
) = N_Explicit_Dereference
);
12476 -- Do not re-expand a dereference which has already been processed by
12479 if Has_Dereference_Action
(Context
) then
12482 -- Do not perform this type of expansion for internally-generated
12485 elsif not Comes_From_Source
(Original_Node
(Context
)) then
12488 -- A dereference action is only applicable to objects which have been
12489 -- allocated on a checked pool.
12491 elsif not Is_Checked_Storage_Pool
(Pool
) then
12495 -- Extract the address of the dereferenced object. Generate:
12497 -- Addr : System.Address := <N>'Pool_Address;
12499 Addr
:= Make_Temporary
(Loc
, 'P');
12502 Make_Object_Declaration
(Loc
,
12503 Defining_Identifier
=> Addr
,
12504 Object_Definition
=>
12505 New_Occurrence_Of
(RTE
(RE_Address
), Loc
),
12507 Make_Attribute_Reference
(Loc
,
12508 Prefix
=> Duplicate_Subexpr_Move_Checks
(N
),
12509 Attribute_Name
=> Name_Pool_Address
)));
12511 -- Calculate the size of the dereferenced object. Generate:
12513 -- Size : Storage_Count := <N>.all'Size / Storage_Unit;
12516 Make_Explicit_Dereference
(Loc
,
12517 Prefix
=> Duplicate_Subexpr_Move_Checks
(N
));
12518 Set_Has_Dereference_Action
(Deref
);
12521 Make_Attribute_Reference
(Loc
,
12523 Attribute_Name
=> Name_Size
);
12525 -- Special case of an unconstrained array: need to add descriptor size
12527 if Is_Array_Type
(Desig_Typ
)
12528 and then not Is_Constrained
(First_Subtype
(Desig_Typ
))
12533 Make_Attribute_Reference
(Loc
,
12535 New_Occurrence_Of
(First_Subtype
(Desig_Typ
), Loc
),
12536 Attribute_Name
=> Name_Descriptor_Size
),
12537 Right_Opnd
=> Size_Bits
);
12540 Size
:= Make_Temporary
(Loc
, 'S');
12542 Make_Object_Declaration
(Loc
,
12543 Defining_Identifier
=> Size
,
12544 Object_Definition
=>
12545 New_Occurrence_Of
(RTE
(RE_Storage_Count
), Loc
),
12547 Make_Op_Divide
(Loc
,
12548 Left_Opnd
=> Size_Bits
,
12549 Right_Opnd
=> Make_Integer_Literal
(Loc
, System_Storage_Unit
))));
12551 -- Calculate the alignment of the dereferenced object. Generate:
12552 -- Alig : constant Storage_Count := <N>.all'Alignment;
12555 Make_Explicit_Dereference
(Loc
,
12556 Prefix
=> Duplicate_Subexpr_Move_Checks
(N
));
12557 Set_Has_Dereference_Action
(Deref
);
12559 Alig
:= Make_Temporary
(Loc
, 'A');
12561 Make_Object_Declaration
(Loc
,
12562 Defining_Identifier
=> Alig
,
12563 Object_Definition
=>
12564 New_Occurrence_Of
(RTE
(RE_Storage_Count
), Loc
),
12566 Make_Attribute_Reference
(Loc
,
12568 Attribute_Name
=> Name_Alignment
)));
12570 -- A dereference of a controlled object requires special processing. The
12571 -- finalization machinery requests additional space from the underlying
12572 -- pool to allocate and hide two pointers. As a result, a checked pool
12573 -- may mark the wrong memory as valid. Since checked pools do not have
12574 -- knowledge of hidden pointers, we have to bring the two pointers back
12575 -- in view in order to restore the original state of the object.
12577 -- The address manipulation is not performed for access types that are
12578 -- subject to pragma No_Heap_Finalization because the two pointers do
12579 -- not exist in the first place.
12581 if No_Heap_Finalization
(Ptr_Typ
) then
12584 elsif Needs_Finalization
(Desig_Typ
) then
12586 -- Adjust the address and size of the dereferenced object. Generate:
12587 -- Adjust_Controlled_Dereference (Addr, Size, Alig);
12590 Make_Procedure_Call_Statement
(Loc
,
12592 New_Occurrence_Of
(RTE
(RE_Adjust_Controlled_Dereference
), Loc
),
12593 Parameter_Associations
=> New_List
(
12594 New_Occurrence_Of
(Addr
, Loc
),
12595 New_Occurrence_Of
(Size
, Loc
),
12596 New_Occurrence_Of
(Alig
, Loc
)));
12598 -- Class-wide types complicate things because we cannot determine
12599 -- statically whether the actual object is truly controlled. We must
12600 -- generate a runtime check to detect this property. Generate:
12602 -- if Needs_Finalization (<N>.all'Tag) then
12606 if Is_Class_Wide_Type
(Desig_Typ
) then
12608 Make_Explicit_Dereference
(Loc
,
12609 Prefix
=> Duplicate_Subexpr_Move_Checks
(N
));
12610 Set_Has_Dereference_Action
(Deref
);
12613 Make_Implicit_If_Statement
(N
,
12615 Make_Function_Call
(Loc
,
12617 New_Occurrence_Of
(RTE
(RE_Needs_Finalization
), Loc
),
12618 Parameter_Associations
=> New_List
(
12619 Make_Attribute_Reference
(Loc
,
12621 Attribute_Name
=> Name_Tag
))),
12622 Then_Statements
=> New_List
(Stmt
));
12625 Insert_Action
(N
, Stmt
);
12629 -- Dereference (Pool, Addr, Size, Alig);
12632 Make_Procedure_Call_Statement
(Loc
,
12635 (Find_Prim_Op
(Etype
(Pool
), Name_Dereference
), Loc
),
12636 Parameter_Associations
=> New_List
(
12637 New_Occurrence_Of
(Pool
, Loc
),
12638 New_Occurrence_Of
(Addr
, Loc
),
12639 New_Occurrence_Of
(Size
, Loc
),
12640 New_Occurrence_Of
(Alig
, Loc
))));
12642 -- Mark the explicit dereference as processed to avoid potential
12643 -- infinite expansion.
12645 Set_Has_Dereference_Action
(Context
);
12648 when RE_Not_Available
=>
12650 end Insert_Dereference_Action
;
12652 --------------------------------
12653 -- Integer_Promotion_Possible --
12654 --------------------------------
12656 function Integer_Promotion_Possible
(N
: Node_Id
) return Boolean is
12657 Operand
: constant Node_Id
:= Expression
(N
);
12658 Operand_Type
: constant Entity_Id
:= Etype
(Operand
);
12659 Root_Operand_Type
: constant Entity_Id
:= Root_Type
(Operand_Type
);
12662 pragma Assert
(Nkind
(N
) = N_Type_Conversion
);
12666 -- We only do the transformation for source constructs. We assume
12667 -- that the expander knows what it is doing when it generates code.
12669 Comes_From_Source
(N
)
12671 -- If the operand type is Short_Integer or Short_Short_Integer,
12672 -- then we will promote to Integer, which is available on all
12673 -- targets, and is sufficient to ensure no intermediate overflow.
12674 -- Furthermore it is likely to be as efficient or more efficient
12675 -- than using the smaller type for the computation so we do this
12676 -- unconditionally.
12679 (Root_Operand_Type
= Base_Type
(Standard_Short_Integer
)
12681 Root_Operand_Type
= Base_Type
(Standard_Short_Short_Integer
))
12683 -- Test for interesting operation, which includes addition,
12684 -- division, exponentiation, multiplication, subtraction, absolute
12685 -- value and unary negation. Unary "+" is omitted since it is a
12686 -- no-op and thus can't overflow.
12688 and then Nkind_In
(Operand
, N_Op_Abs
,
12695 end Integer_Promotion_Possible
;
12697 ------------------------------
12698 -- Make_Array_Comparison_Op --
12699 ------------------------------
12701 -- This is a hand-coded expansion of the following generic function:
12704 -- type elem is (<>);
12705 -- type index is (<>);
12706 -- type a is array (index range <>) of elem;
12708 -- function Gnnn (X : a; Y: a) return boolean is
12709 -- J : index := Y'first;
12712 -- if X'length = 0 then
12715 -- elsif Y'length = 0 then
12719 -- for I in X'range loop
12720 -- if X (I) = Y (J) then
12721 -- if J = Y'last then
12724 -- J := index'succ (J);
12728 -- return X (I) > Y (J);
12732 -- return X'length > Y'length;
12736 -- Note that since we are essentially doing this expansion by hand, we
12737 -- do not need to generate an actual or formal generic part, just the
12738 -- instantiated function itself.
12740 -- Perhaps we could have the actual generic available in the run-time,
12741 -- obtained by rtsfind, and actually expand a real instantiation ???
12743 function Make_Array_Comparison_Op
12745 Nod
: Node_Id
) return Node_Id
12747 Loc
: constant Source_Ptr
:= Sloc
(Nod
);
12749 X
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uX
);
12750 Y
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uY
);
12751 I
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uI
);
12752 J
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uJ
);
12754 Index
: constant Entity_Id
:= Base_Type
(Etype
(First_Index
(Typ
)));
12756 Loop_Statement
: Node_Id
;
12757 Loop_Body
: Node_Id
;
12759 Inner_If
: Node_Id
;
12760 Final_Expr
: Node_Id
;
12761 Func_Body
: Node_Id
;
12762 Func_Name
: Entity_Id
;
12768 -- if J = Y'last then
12771 -- J := index'succ (J);
12775 Make_Implicit_If_Statement
(Nod
,
12778 Left_Opnd
=> New_Occurrence_Of
(J
, Loc
),
12780 Make_Attribute_Reference
(Loc
,
12781 Prefix
=> New_Occurrence_Of
(Y
, Loc
),
12782 Attribute_Name
=> Name_Last
)),
12784 Then_Statements
=> New_List
(
12785 Make_Exit_Statement
(Loc
)),
12789 Make_Assignment_Statement
(Loc
,
12790 Name
=> New_Occurrence_Of
(J
, Loc
),
12792 Make_Attribute_Reference
(Loc
,
12793 Prefix
=> New_Occurrence_Of
(Index
, Loc
),
12794 Attribute_Name
=> Name_Succ
,
12795 Expressions
=> New_List
(New_Occurrence_Of
(J
, Loc
))))));
12797 -- if X (I) = Y (J) then
12800 -- return X (I) > Y (J);
12804 Make_Implicit_If_Statement
(Nod
,
12808 Make_Indexed_Component
(Loc
,
12809 Prefix
=> New_Occurrence_Of
(X
, Loc
),
12810 Expressions
=> New_List
(New_Occurrence_Of
(I
, Loc
))),
12813 Make_Indexed_Component
(Loc
,
12814 Prefix
=> New_Occurrence_Of
(Y
, Loc
),
12815 Expressions
=> New_List
(New_Occurrence_Of
(J
, Loc
)))),
12817 Then_Statements
=> New_List
(Inner_If
),
12819 Else_Statements
=> New_List
(
12820 Make_Simple_Return_Statement
(Loc
,
12824 Make_Indexed_Component
(Loc
,
12825 Prefix
=> New_Occurrence_Of
(X
, Loc
),
12826 Expressions
=> New_List
(New_Occurrence_Of
(I
, Loc
))),
12829 Make_Indexed_Component
(Loc
,
12830 Prefix
=> New_Occurrence_Of
(Y
, Loc
),
12831 Expressions
=> New_List
(
12832 New_Occurrence_Of
(J
, Loc
)))))));
12834 -- for I in X'range loop
12839 Make_Implicit_Loop_Statement
(Nod
,
12840 Identifier
=> Empty
,
12842 Iteration_Scheme
=>
12843 Make_Iteration_Scheme
(Loc
,
12844 Loop_Parameter_Specification
=>
12845 Make_Loop_Parameter_Specification
(Loc
,
12846 Defining_Identifier
=> I
,
12847 Discrete_Subtype_Definition
=>
12848 Make_Attribute_Reference
(Loc
,
12849 Prefix
=> New_Occurrence_Of
(X
, Loc
),
12850 Attribute_Name
=> Name_Range
))),
12852 Statements
=> New_List
(Loop_Body
));
12854 -- if X'length = 0 then
12856 -- elsif Y'length = 0 then
12859 -- for ... loop ... end loop;
12860 -- return X'length > Y'length;
12864 Make_Attribute_Reference
(Loc
,
12865 Prefix
=> New_Occurrence_Of
(X
, Loc
),
12866 Attribute_Name
=> Name_Length
);
12869 Make_Attribute_Reference
(Loc
,
12870 Prefix
=> New_Occurrence_Of
(Y
, Loc
),
12871 Attribute_Name
=> Name_Length
);
12875 Left_Opnd
=> Length1
,
12876 Right_Opnd
=> Length2
);
12879 Make_Implicit_If_Statement
(Nod
,
12883 Make_Attribute_Reference
(Loc
,
12884 Prefix
=> New_Occurrence_Of
(X
, Loc
),
12885 Attribute_Name
=> Name_Length
),
12887 Make_Integer_Literal
(Loc
, 0)),
12891 Make_Simple_Return_Statement
(Loc
,
12892 Expression
=> New_Occurrence_Of
(Standard_False
, Loc
))),
12894 Elsif_Parts
=> New_List
(
12895 Make_Elsif_Part
(Loc
,
12899 Make_Attribute_Reference
(Loc
,
12900 Prefix
=> New_Occurrence_Of
(Y
, Loc
),
12901 Attribute_Name
=> Name_Length
),
12903 Make_Integer_Literal
(Loc
, 0)),
12907 Make_Simple_Return_Statement
(Loc
,
12908 Expression
=> New_Occurrence_Of
(Standard_True
, Loc
))))),
12910 Else_Statements
=> New_List
(
12912 Make_Simple_Return_Statement
(Loc
,
12913 Expression
=> Final_Expr
)));
12917 Formals
:= New_List
(
12918 Make_Parameter_Specification
(Loc
,
12919 Defining_Identifier
=> X
,
12920 Parameter_Type
=> New_Occurrence_Of
(Typ
, Loc
)),
12922 Make_Parameter_Specification
(Loc
,
12923 Defining_Identifier
=> Y
,
12924 Parameter_Type
=> New_Occurrence_Of
(Typ
, Loc
)));
12926 -- function Gnnn (...) return boolean is
12927 -- J : index := Y'first;
12932 Func_Name
:= Make_Temporary
(Loc
, 'G');
12935 Make_Subprogram_Body
(Loc
,
12937 Make_Function_Specification
(Loc
,
12938 Defining_Unit_Name
=> Func_Name
,
12939 Parameter_Specifications
=> Formals
,
12940 Result_Definition
=> New_Occurrence_Of
(Standard_Boolean
, Loc
)),
12942 Declarations
=> New_List
(
12943 Make_Object_Declaration
(Loc
,
12944 Defining_Identifier
=> J
,
12945 Object_Definition
=> New_Occurrence_Of
(Index
, Loc
),
12947 Make_Attribute_Reference
(Loc
,
12948 Prefix
=> New_Occurrence_Of
(Y
, Loc
),
12949 Attribute_Name
=> Name_First
))),
12951 Handled_Statement_Sequence
=>
12952 Make_Handled_Sequence_Of_Statements
(Loc
,
12953 Statements
=> New_List
(If_Stat
)));
12956 end Make_Array_Comparison_Op
;
12958 ---------------------------
12959 -- Make_Boolean_Array_Op --
12960 ---------------------------
12962 -- For logical operations on boolean arrays, expand in line the following,
12963 -- replacing 'and' with 'or' or 'xor' where needed:
12965 -- function Annn (A : typ; B: typ) return typ is
12968 -- for J in A'range loop
12969 -- C (J) := A (J) op B (J);
12974 -- Here typ is the boolean array type
12976 function Make_Boolean_Array_Op
12978 N
: Node_Id
) return Node_Id
12980 Loc
: constant Source_Ptr
:= Sloc
(N
);
12982 A
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uA
);
12983 B
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uB
);
12984 C
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uC
);
12985 J
: constant Entity_Id
:= Make_Defining_Identifier
(Loc
, Name_uJ
);
12993 Func_Name
: Entity_Id
;
12994 Func_Body
: Node_Id
;
12995 Loop_Statement
: Node_Id
;
12999 Make_Indexed_Component
(Loc
,
13000 Prefix
=> New_Occurrence_Of
(A
, Loc
),
13001 Expressions
=> New_List
(New_Occurrence_Of
(J
, Loc
)));
13004 Make_Indexed_Component
(Loc
,
13005 Prefix
=> New_Occurrence_Of
(B
, Loc
),
13006 Expressions
=> New_List
(New_Occurrence_Of
(J
, Loc
)));
13009 Make_Indexed_Component
(Loc
,
13010 Prefix
=> New_Occurrence_Of
(C
, Loc
),
13011 Expressions
=> New_List
(New_Occurrence_Of
(J
, Loc
)));
13013 if Nkind
(N
) = N_Op_And
then
13017 Right_Opnd
=> B_J
);
13019 elsif Nkind
(N
) = N_Op_Or
then
13023 Right_Opnd
=> B_J
);
13029 Right_Opnd
=> B_J
);
13033 Make_Implicit_Loop_Statement
(N
,
13034 Identifier
=> Empty
,
13036 Iteration_Scheme
=>
13037 Make_Iteration_Scheme
(Loc
,
13038 Loop_Parameter_Specification
=>
13039 Make_Loop_Parameter_Specification
(Loc
,
13040 Defining_Identifier
=> J
,
13041 Discrete_Subtype_Definition
=>
13042 Make_Attribute_Reference
(Loc
,
13043 Prefix
=> New_Occurrence_Of
(A
, Loc
),
13044 Attribute_Name
=> Name_Range
))),
13046 Statements
=> New_List
(
13047 Make_Assignment_Statement
(Loc
,
13049 Expression
=> Op
)));
13051 Formals
:= New_List
(
13052 Make_Parameter_Specification
(Loc
,
13053 Defining_Identifier
=> A
,
13054 Parameter_Type
=> New_Occurrence_Of
(Typ
, Loc
)),
13056 Make_Parameter_Specification
(Loc
,
13057 Defining_Identifier
=> B
,
13058 Parameter_Type
=> New_Occurrence_Of
(Typ
, Loc
)));
13060 Func_Name
:= Make_Temporary
(Loc
, 'A');
13061 Set_Is_Inlined
(Func_Name
);
13064 Make_Subprogram_Body
(Loc
,
13066 Make_Function_Specification
(Loc
,
13067 Defining_Unit_Name
=> Func_Name
,
13068 Parameter_Specifications
=> Formals
,
13069 Result_Definition
=> New_Occurrence_Of
(Typ
, Loc
)),
13071 Declarations
=> New_List
(
13072 Make_Object_Declaration
(Loc
,
13073 Defining_Identifier
=> C
,
13074 Object_Definition
=> New_Occurrence_Of
(Typ
, Loc
))),
13076 Handled_Statement_Sequence
=>
13077 Make_Handled_Sequence_Of_Statements
(Loc
,
13078 Statements
=> New_List
(
13080 Make_Simple_Return_Statement
(Loc
,
13081 Expression
=> New_Occurrence_Of
(C
, Loc
)))));
13084 end Make_Boolean_Array_Op
;
13086 -----------------------------------------
13087 -- Minimized_Eliminated_Overflow_Check --
13088 -----------------------------------------
13090 function Minimized_Eliminated_Overflow_Check
(N
: Node_Id
) return Boolean is
13093 Is_Signed_Integer_Type
(Etype
(N
))
13094 and then Overflow_Check_Mode
in Minimized_Or_Eliminated
;
13095 end Minimized_Eliminated_Overflow_Check
;
13097 --------------------------------
13098 -- Optimize_Length_Comparison --
13099 --------------------------------
13101 procedure Optimize_Length_Comparison
(N
: Node_Id
) is
13102 Loc
: constant Source_Ptr
:= Sloc
(N
);
13103 Typ
: constant Entity_Id
:= Etype
(N
);
13108 -- First and Last attribute reference nodes, which end up as left and
13109 -- right operands of the optimized result.
13112 -- True for comparison operand of zero
13115 -- Comparison operand, set only if Is_Zero is false
13117 Ent
: Entity_Id
:= Empty
;
13118 -- Entity whose length is being compared
13120 Index
: Node_Id
:= Empty
;
13121 -- Integer_Literal node for length attribute expression, or Empty
13122 -- if there is no such expression present.
13125 -- Type of array index to which 'Length is applied
13127 Op
: Node_Kind
:= Nkind
(N
);
13128 -- Kind of comparison operator, gets flipped if operands backwards
13130 function Is_Optimizable
(N
: Node_Id
) return Boolean;
13131 -- Tests N to see if it is an optimizable comparison value (defined as
13132 -- constant zero or one, or something else where the value is known to
13133 -- be positive and in the range of 32-bits, and where the corresponding
13134 -- Length value is also known to be 32-bits. If result is true, sets
13135 -- Is_Zero, Ityp, and Comp accordingly.
13137 function Is_Entity_Length
(N
: Node_Id
) return Boolean;
13138 -- Tests if N is a length attribute applied to a simple entity. If so,
13139 -- returns True, and sets Ent to the entity, and Index to the integer
13140 -- literal provided as an attribute expression, or to Empty if none.
13141 -- Also returns True if the expression is a generated type conversion
13142 -- whose expression is of the desired form. This latter case arises
13143 -- when Apply_Universal_Integer_Attribute_Check installs a conversion
13144 -- to check for being in range, which is not needed in this context.
13145 -- Returns False if neither condition holds.
13147 function Prepare_64
(N
: Node_Id
) return Node_Id
;
13148 -- Given a discrete expression, returns a Long_Long_Integer typed
13149 -- expression representing the underlying value of the expression.
13150 -- This is done with an unchecked conversion to the result type. We
13151 -- use unchecked conversion to handle the enumeration type case.
13153 ----------------------
13154 -- Is_Entity_Length --
13155 ----------------------
13157 function Is_Entity_Length
(N
: Node_Id
) return Boolean is
13159 if Nkind
(N
) = N_Attribute_Reference
13160 and then Attribute_Name
(N
) = Name_Length
13161 and then Is_Entity_Name
(Prefix
(N
))
13163 Ent
:= Entity
(Prefix
(N
));
13165 if Present
(Expressions
(N
)) then
13166 Index
:= First
(Expressions
(N
));
13173 elsif Nkind
(N
) = N_Type_Conversion
13174 and then not Comes_From_Source
(N
)
13176 return Is_Entity_Length
(Expression
(N
));
13181 end Is_Entity_Length
;
13183 --------------------
13184 -- Is_Optimizable --
13185 --------------------
13187 function Is_Optimizable
(N
: Node_Id
) return Boolean is
13195 if Compile_Time_Known_Value
(N
) then
13196 Val
:= Expr_Value
(N
);
13198 if Val
= Uint_0
then
13203 elsif Val
= Uint_1
then
13210 -- Here we have to make sure of being within 32-bits
13212 Determine_Range
(N
, OK
, Lo
, Hi
, Assume_Valid
=> True);
13215 or else Lo
< Uint_1
13216 or else Hi
> UI_From_Int
(Int
'Last)
13221 -- Comparison value was within range, so now we must check the index
13222 -- value to make sure it is also within 32-bits.
13224 Indx
:= First_Index
(Etype
(Ent
));
13226 if Present
(Index
) then
13227 for J
in 2 .. UI_To_Int
(Intval
(Index
)) loop
13232 Ityp
:= Etype
(Indx
);
13234 if Esize
(Ityp
) > 32 then
13241 end Is_Optimizable
;
13247 function Prepare_64
(N
: Node_Id
) return Node_Id
is
13249 return Unchecked_Convert_To
(Standard_Long_Long_Integer
, N
);
13252 -- Start of processing for Optimize_Length_Comparison
13255 -- Nothing to do if not a comparison
13257 if Op
not in N_Op_Compare
then
13261 -- Nothing to do if special -gnatd.P debug flag set.
13263 if Debug_Flag_Dot_PP
then
13267 -- Ent'Length op 0/1
13269 if Is_Entity_Length
(Left_Opnd
(N
))
13270 and then Is_Optimizable
(Right_Opnd
(N
))
13274 -- 0/1 op Ent'Length
13276 elsif Is_Entity_Length
(Right_Opnd
(N
))
13277 and then Is_Optimizable
(Left_Opnd
(N
))
13279 -- Flip comparison to opposite sense
13282 when N_Op_Lt
=> Op
:= N_Op_Gt
;
13283 when N_Op_Le
=> Op
:= N_Op_Ge
;
13284 when N_Op_Gt
=> Op
:= N_Op_Lt
;
13285 when N_Op_Ge
=> Op
:= N_Op_Le
;
13286 when others => null;
13289 -- Else optimization not possible
13295 -- Fall through if we will do the optimization
13297 -- Cases to handle:
13299 -- X'Length = 0 => X'First > X'Last
13300 -- X'Length = 1 => X'First = X'Last
13301 -- X'Length = n => X'First + (n - 1) = X'Last
13303 -- X'Length /= 0 => X'First <= X'Last
13304 -- X'Length /= 1 => X'First /= X'Last
13305 -- X'Length /= n => X'First + (n - 1) /= X'Last
13307 -- X'Length >= 0 => always true, warn
13308 -- X'Length >= 1 => X'First <= X'Last
13309 -- X'Length >= n => X'First + (n - 1) <= X'Last
13311 -- X'Length > 0 => X'First <= X'Last
13312 -- X'Length > 1 => X'First < X'Last
13313 -- X'Length > n => X'First + (n - 1) < X'Last
13315 -- X'Length <= 0 => X'First > X'Last (warn, could be =)
13316 -- X'Length <= 1 => X'First >= X'Last
13317 -- X'Length <= n => X'First + (n - 1) >= X'Last
13319 -- X'Length < 0 => always false (warn)
13320 -- X'Length < 1 => X'First > X'Last
13321 -- X'Length < n => X'First + (n - 1) > X'Last
13323 -- Note: for the cases of n (not constant 0,1), we require that the
13324 -- corresponding index type be integer or shorter (i.e. not 64-bit),
13325 -- and the same for the comparison value. Then we do the comparison
13326 -- using 64-bit arithmetic (actually long long integer), so that we
13327 -- cannot have overflow intefering with the result.
13329 -- First deal with warning cases
13338 Convert_To
(Typ
, New_Occurrence_Of
(Standard_True
, Loc
)));
13339 Analyze_And_Resolve
(N
, Typ
);
13340 Warn_On_Known_Condition
(N
);
13347 Convert_To
(Typ
, New_Occurrence_Of
(Standard_False
, Loc
)));
13348 Analyze_And_Resolve
(N
, Typ
);
13349 Warn_On_Known_Condition
(N
);
13353 if Constant_Condition_Warnings
13354 and then Comes_From_Source
(Original_Node
(N
))
13356 Error_Msg_N
("could replace by ""'=""?c?", N
);
13366 -- Build the First reference we will use
13369 Make_Attribute_Reference
(Loc
,
13370 Prefix
=> New_Occurrence_Of
(Ent
, Loc
),
13371 Attribute_Name
=> Name_First
);
13373 if Present
(Index
) then
13374 Set_Expressions
(Left
, New_List
(New_Copy
(Index
)));
13377 -- If general value case, then do the addition of (n - 1), and
13378 -- also add the needed conversions to type Long_Long_Integer.
13380 if Present
(Comp
) then
13383 Left_Opnd
=> Prepare_64
(Left
),
13385 Make_Op_Subtract
(Loc
,
13386 Left_Opnd
=> Prepare_64
(Comp
),
13387 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1)));
13390 -- Build the Last reference we will use
13393 Make_Attribute_Reference
(Loc
,
13394 Prefix
=> New_Occurrence_Of
(Ent
, Loc
),
13395 Attribute_Name
=> Name_Last
);
13397 if Present
(Index
) then
13398 Set_Expressions
(Right
, New_List
(New_Copy
(Index
)));
13401 -- If general operand, convert Last reference to Long_Long_Integer
13403 if Present
(Comp
) then
13404 Right
:= Prepare_64
(Right
);
13407 -- Check for cases to optimize
13409 -- X'Length = 0 => X'First > X'Last
13410 -- X'Length < 1 => X'First > X'Last
13411 -- X'Length < n => X'First + (n - 1) > X'Last
13413 if (Is_Zero
and then Op
= N_Op_Eq
)
13414 or else (not Is_Zero
and then Op
= N_Op_Lt
)
13419 Right_Opnd
=> Right
);
13421 -- X'Length = 1 => X'First = X'Last
13422 -- X'Length = n => X'First + (n - 1) = X'Last
13424 elsif not Is_Zero
and then Op
= N_Op_Eq
then
13428 Right_Opnd
=> Right
);
13430 -- X'Length /= 0 => X'First <= X'Last
13431 -- X'Length > 0 => X'First <= X'Last
13433 elsif Is_Zero
and (Op
= N_Op_Ne
or else Op
= N_Op_Gt
) then
13437 Right_Opnd
=> Right
);
13439 -- X'Length /= 1 => X'First /= X'Last
13440 -- X'Length /= n => X'First + (n - 1) /= X'Last
13442 elsif not Is_Zero
and then Op
= N_Op_Ne
then
13446 Right_Opnd
=> Right
);
13448 -- X'Length >= 1 => X'First <= X'Last
13449 -- X'Length >= n => X'First + (n - 1) <= X'Last
13451 elsif not Is_Zero
and then Op
= N_Op_Ge
then
13455 Right_Opnd
=> Right
);
13457 -- X'Length > 1 => X'First < X'Last
13458 -- X'Length > n => X'First + (n = 1) < X'Last
13460 elsif not Is_Zero
and then Op
= N_Op_Gt
then
13464 Right_Opnd
=> Right
);
13466 -- X'Length <= 1 => X'First >= X'Last
13467 -- X'Length <= n => X'First + (n - 1) >= X'Last
13469 elsif not Is_Zero
and then Op
= N_Op_Le
then
13473 Right_Opnd
=> Right
);
13475 -- Should not happen at this stage
13478 raise Program_Error
;
13481 -- Rewrite and finish up
13483 Rewrite
(N
, Result
);
13484 Analyze_And_Resolve
(N
, Typ
);
13486 end Optimize_Length_Comparison
;
13488 --------------------------------
13489 -- Process_If_Case_Statements --
13490 --------------------------------
13492 procedure Process_If_Case_Statements
(N
: Node_Id
; Stmts
: List_Id
) is
13496 Decl
:= First
(Stmts
);
13497 while Present
(Decl
) loop
13498 if Nkind
(Decl
) = N_Object_Declaration
13499 and then Is_Finalizable_Transient
(Decl
, N
)
13501 Process_Transient_In_Expression
(Decl
, N
, Stmts
);
13506 end Process_If_Case_Statements
;
13508 -------------------------------------
13509 -- Process_Transient_In_Expression --
13510 -------------------------------------
13512 procedure Process_Transient_In_Expression
13513 (Obj_Decl
: Node_Id
;
13517 Loc
: constant Source_Ptr
:= Sloc
(Obj_Decl
);
13518 Obj_Id
: constant Entity_Id
:= Defining_Identifier
(Obj_Decl
);
13520 Hook_Context
: constant Node_Id
:= Find_Hook_Context
(Expr
);
13521 -- The node on which to insert the hook as an action. This is usually
13522 -- the innermost enclosing non-transient construct.
13524 Fin_Call
: Node_Id
;
13525 Hook_Assign
: Node_Id
;
13526 Hook_Clear
: Node_Id
;
13527 Hook_Decl
: Node_Id
;
13528 Hook_Insert
: Node_Id
;
13529 Ptr_Decl
: Node_Id
;
13531 Fin_Context
: Node_Id
;
13532 -- The node after which to insert the finalization actions of the
13533 -- transient object.
13536 pragma Assert
(Nkind_In
(Expr
, N_Case_Expression
,
13537 N_Expression_With_Actions
,
13540 -- When the context is a Boolean evaluation, all three nodes capture the
13541 -- result of their computation in a local temporary:
13544 -- Trans_Id : Ctrl_Typ := ...;
13545 -- Result : constant Boolean := ... Trans_Id ...;
13546 -- <finalize Trans_Id>
13549 -- As a result, the finalization of any transient objects can safely
13550 -- take place after the result capture.
13552 -- ??? could this be extended to elementary types?
13554 if Is_Boolean_Type
(Etype
(Expr
)) then
13555 Fin_Context
:= Last
(Stmts
);
13557 -- Otherwise the immediate context may not be safe enough to carry
13558 -- out transient object finalization due to aliasing and nesting of
13559 -- constructs. Insert calls to [Deep_]Finalize after the innermost
13560 -- enclosing non-transient construct.
13563 Fin_Context
:= Hook_Context
;
13566 -- Mark the transient object as successfully processed to avoid double
13569 Set_Is_Finalized_Transient
(Obj_Id
);
13571 -- Construct all the pieces necessary to hook and finalize a transient
13574 Build_Transient_Object_Statements
13575 (Obj_Decl
=> Obj_Decl
,
13576 Fin_Call
=> Fin_Call
,
13577 Hook_Assign
=> Hook_Assign
,
13578 Hook_Clear
=> Hook_Clear
,
13579 Hook_Decl
=> Hook_Decl
,
13580 Ptr_Decl
=> Ptr_Decl
,
13581 Finalize_Obj
=> False);
13583 -- Add the access type which provides a reference to the transient
13584 -- object. Generate:
13586 -- type Ptr_Typ is access all Desig_Typ;
13588 Insert_Action
(Hook_Context
, Ptr_Decl
);
13590 -- Add the temporary which acts as a hook to the transient object.
13593 -- Hook : Ptr_Id := null;
13595 Insert_Action
(Hook_Context
, Hook_Decl
);
13597 -- When the transient object is initialized by an aggregate, the hook
13598 -- must capture the object after the last aggregate assignment takes
13599 -- place. Only then is the object considered initialized. Generate:
13601 -- Hook := Ptr_Typ (Obj_Id);
13603 -- Hook := Obj_Id'Unrestricted_Access;
13605 if Ekind_In
(Obj_Id
, E_Constant
, E_Variable
)
13606 and then Present
(Last_Aggregate_Assignment
(Obj_Id
))
13608 Hook_Insert
:= Last_Aggregate_Assignment
(Obj_Id
);
13610 -- Otherwise the hook seizes the related object immediately
13613 Hook_Insert
:= Obj_Decl
;
13616 Insert_After_And_Analyze
(Hook_Insert
, Hook_Assign
);
13618 -- When the node is part of a return statement, there is no need to
13619 -- insert a finalization call, as the general finalization mechanism
13620 -- (see Build_Finalizer) would take care of the transient object on
13621 -- subprogram exit. Note that it would also be impossible to insert the
13622 -- finalization code after the return statement as this will render it
13625 if Nkind
(Fin_Context
) = N_Simple_Return_Statement
then
13628 -- Finalize the hook after the context has been evaluated. Generate:
13630 -- if Hook /= null then
13631 -- [Deep_]Finalize (Hook.all);
13636 Insert_Action_After
(Fin_Context
,
13637 Make_Implicit_If_Statement
(Obj_Decl
,
13641 New_Occurrence_Of
(Defining_Entity
(Hook_Decl
), Loc
),
13642 Right_Opnd
=> Make_Null
(Loc
)),
13644 Then_Statements
=> New_List
(
13648 end Process_Transient_In_Expression
;
13650 ------------------------
13651 -- Rewrite_Comparison --
13652 ------------------------
13654 procedure Rewrite_Comparison
(N
: Node_Id
) is
13655 Typ
: constant Entity_Id
:= Etype
(N
);
13657 False_Result
: Boolean;
13658 True_Result
: Boolean;
13661 if Nkind
(N
) = N_Type_Conversion
then
13662 Rewrite_Comparison
(Expression
(N
));
13665 elsif Nkind
(N
) not in N_Op_Compare
then
13669 -- Determine the potential outcome of the comparison assuming that the
13670 -- operands are valid and emit a warning when the comparison evaluates
13671 -- to True or False only in the presence of invalid values.
13673 Warn_On_Constant_Valid_Condition
(N
);
13675 -- Determine the potential outcome of the comparison assuming that the
13676 -- operands are not valid.
13680 Assume_Valid
=> False,
13681 True_Result
=> True_Result
,
13682 False_Result
=> False_Result
);
13684 -- The outcome is a decisive False or True, rewrite the operator
13686 if False_Result
or True_Result
then
13689 New_Occurrence_Of
(Boolean_Literals
(True_Result
), Sloc
(N
))));
13691 Analyze_And_Resolve
(N
, Typ
);
13692 Warn_On_Known_Condition
(N
);
13694 end Rewrite_Comparison
;
13696 ----------------------------
13697 -- Safe_In_Place_Array_Op --
13698 ----------------------------
13700 function Safe_In_Place_Array_Op
13703 Op2
: Node_Id
) return Boolean
13705 Target
: Entity_Id
;
13707 function Is_Safe_Operand
(Op
: Node_Id
) return Boolean;
13708 -- Operand is safe if it cannot overlap part of the target of the
13709 -- operation. If the operand and the target are identical, the operand
13710 -- is safe. The operand can be empty in the case of negation.
13712 function Is_Unaliased
(N
: Node_Id
) return Boolean;
13713 -- Check that N is a stand-alone entity
13719 function Is_Unaliased
(N
: Node_Id
) return Boolean is
13723 and then No
(Address_Clause
(Entity
(N
)))
13724 and then No
(Renamed_Object
(Entity
(N
)));
13727 ---------------------
13728 -- Is_Safe_Operand --
13729 ---------------------
13731 function Is_Safe_Operand
(Op
: Node_Id
) return Boolean is
13736 elsif Is_Entity_Name
(Op
) then
13737 return Is_Unaliased
(Op
);
13739 elsif Nkind_In
(Op
, N_Indexed_Component
, N_Selected_Component
) then
13740 return Is_Unaliased
(Prefix
(Op
));
13742 elsif Nkind
(Op
) = N_Slice
then
13744 Is_Unaliased
(Prefix
(Op
))
13745 and then Entity
(Prefix
(Op
)) /= Target
;
13747 elsif Nkind
(Op
) = N_Op_Not
then
13748 return Is_Safe_Operand
(Right_Opnd
(Op
));
13753 end Is_Safe_Operand
;
13755 -- Start of processing for Safe_In_Place_Array_Op
13758 -- Skip this processing if the component size is different from system
13759 -- storage unit (since at least for NOT this would cause problems).
13761 if Component_Size
(Etype
(Lhs
)) /= System_Storage_Unit
then
13764 -- Cannot do in place stuff if non-standard Boolean representation
13766 elsif Has_Non_Standard_Rep
(Component_Type
(Etype
(Lhs
))) then
13769 elsif not Is_Unaliased
(Lhs
) then
13773 Target
:= Entity
(Lhs
);
13774 return Is_Safe_Operand
(Op1
) and then Is_Safe_Operand
(Op2
);
13776 end Safe_In_Place_Array_Op
;
13778 -----------------------
13779 -- Tagged_Membership --
13780 -----------------------
13782 -- There are two different cases to consider depending on whether the right
13783 -- operand is a class-wide type or not. If not we just compare the actual
13784 -- tag of the left expr to the target type tag:
13786 -- Left_Expr.Tag = Right_Type'Tag;
13788 -- If it is a class-wide type we use the RT function CW_Membership which is
13789 -- usually implemented by looking in the ancestor tables contained in the
13790 -- dispatch table pointed by Left_Expr.Tag for Typ'Tag
13792 -- Ada 2005 (AI-251): If it is a class-wide interface type we use the RT
13793 -- function IW_Membership which is usually implemented by looking in the
13794 -- table of abstract interface types plus the ancestor table contained in
13795 -- the dispatch table pointed by Left_Expr.Tag for Typ'Tag
13797 procedure Tagged_Membership
13799 SCIL_Node
: out Node_Id
;
13800 Result
: out Node_Id
)
13802 Left
: constant Node_Id
:= Left_Opnd
(N
);
13803 Right
: constant Node_Id
:= Right_Opnd
(N
);
13804 Loc
: constant Source_Ptr
:= Sloc
(N
);
13806 Full_R_Typ
: Entity_Id
;
13807 Left_Type
: Entity_Id
;
13808 New_Node
: Node_Id
;
13809 Right_Type
: Entity_Id
;
13813 SCIL_Node
:= Empty
;
13815 -- Handle entities from the limited view
13817 Left_Type
:= Available_View
(Etype
(Left
));
13818 Right_Type
:= Available_View
(Etype
(Right
));
13820 -- In the case where the type is an access type, the test is applied
13821 -- using the designated types (needed in Ada 2012 for implicit anonymous
13822 -- access conversions, for AI05-0149).
13824 if Is_Access_Type
(Right_Type
) then
13825 Left_Type
:= Designated_Type
(Left_Type
);
13826 Right_Type
:= Designated_Type
(Right_Type
);
13829 if Is_Class_Wide_Type
(Left_Type
) then
13830 Left_Type
:= Root_Type
(Left_Type
);
13833 if Is_Class_Wide_Type
(Right_Type
) then
13834 Full_R_Typ
:= Underlying_Type
(Root_Type
(Right_Type
));
13836 Full_R_Typ
:= Underlying_Type
(Right_Type
);
13840 Make_Selected_Component
(Loc
,
13841 Prefix
=> Relocate_Node
(Left
),
13843 New_Occurrence_Of
(First_Tag_Component
(Left_Type
), Loc
));
13845 if Is_Class_Wide_Type
(Right_Type
) then
13847 -- No need to issue a run-time check if we statically know that the
13848 -- result of this membership test is always true. For example,
13849 -- considering the following declarations:
13851 -- type Iface is interface;
13852 -- type T is tagged null record;
13853 -- type DT is new T and Iface with null record;
13858 -- These membership tests are always true:
13861 -- Obj2 in T'Class;
13862 -- Obj2 in Iface'Class;
13864 -- We do not need to handle cases where the membership is illegal.
13867 -- Obj1 in DT'Class; -- Compile time error
13868 -- Obj1 in Iface'Class; -- Compile time error
13870 if not Is_Class_Wide_Type
(Left_Type
)
13871 and then (Is_Ancestor
(Etype
(Right_Type
), Left_Type
,
13872 Use_Full_View
=> True)
13873 or else (Is_Interface
(Etype
(Right_Type
))
13874 and then Interface_Present_In_Ancestor
13876 Iface
=> Etype
(Right_Type
))))
13878 Result
:= New_Occurrence_Of
(Standard_True
, Loc
);
13882 -- Ada 2005 (AI-251): Class-wide applied to interfaces
13884 if Is_Interface
(Etype
(Class_Wide_Type
(Right_Type
)))
13886 -- Support to: "Iface_CW_Typ in Typ'Class"
13888 or else Is_Interface
(Left_Type
)
13890 -- Issue error if IW_Membership operation not available in a
13891 -- configurable run time setting.
13893 if not RTE_Available
(RE_IW_Membership
) then
13895 ("dynamic membership test on interface types", N
);
13901 Make_Function_Call
(Loc
,
13902 Name
=> New_Occurrence_Of
(RTE
(RE_IW_Membership
), Loc
),
13903 Parameter_Associations
=> New_List
(
13904 Make_Attribute_Reference
(Loc
,
13906 Attribute_Name
=> Name_Address
),
13907 New_Occurrence_Of
(
13908 Node
(First_Elmt
(Access_Disp_Table
(Full_R_Typ
))),
13911 -- Ada 95: Normal case
13914 Build_CW_Membership
(Loc
,
13915 Obj_Tag_Node
=> Obj_Tag
,
13917 New_Occurrence_Of
(
13918 Node
(First_Elmt
(Access_Disp_Table
(Full_R_Typ
))), Loc
),
13920 New_Node
=> New_Node
);
13922 -- Generate the SCIL node for this class-wide membership test.
13923 -- Done here because the previous call to Build_CW_Membership
13924 -- relocates Obj_Tag.
13926 if Generate_SCIL
then
13927 SCIL_Node
:= Make_SCIL_Membership_Test
(Sloc
(N
));
13928 Set_SCIL_Entity
(SCIL_Node
, Etype
(Right_Type
));
13929 Set_SCIL_Tag_Value
(SCIL_Node
, Obj_Tag
);
13932 Result
:= New_Node
;
13935 -- Right_Type is not a class-wide type
13938 -- No need to check the tag of the object if Right_Typ is abstract
13940 if Is_Abstract_Type
(Right_Type
) then
13941 Result
:= New_Occurrence_Of
(Standard_False
, Loc
);
13946 Left_Opnd
=> Obj_Tag
,
13949 (Node
(First_Elmt
(Access_Disp_Table
(Full_R_Typ
))), Loc
));
13952 end Tagged_Membership
;
13954 ------------------------------
13955 -- Unary_Op_Validity_Checks --
13956 ------------------------------
13958 procedure Unary_Op_Validity_Checks
(N
: Node_Id
) is
13960 if Validity_Checks_On
and Validity_Check_Operands
then
13961 Ensure_Valid
(Right_Opnd
(N
));
13963 end Unary_Op_Validity_Checks
;