1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, 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 -- Package containing utility procedures used throughout the semantics
28 with Einfo
; use Einfo
;
29 with Exp_Tss
; use Exp_Tss
;
30 with Namet
; use Namet
;
31 with Nmake
; use Nmake
;
32 with Snames
; use Snames
;
33 with Types
; use Types
;
34 with Uintp
; use Uintp
;
35 with Urealp
; use Urealp
;
39 function Abstract_Interface_List
(Typ
: Entity_Id
) return List_Id
;
40 -- Given a type that implements interfaces look for its associated
41 -- definition node and return its list of interfaces.
43 procedure Add_Access_Type_To_Process
(E
: Entity_Id
; A
: Entity_Id
);
44 -- Add A to the list of access types to process when expanding the
47 procedure Add_Global_Declaration
(N
: Node_Id
);
48 -- These procedures adds a declaration N at the library level, to be
49 -- elaborated before any other code in the unit. It is used for example
50 -- for the entity that marks whether a unit has been elaborated. The
51 -- declaration is added to the Declarations list of the Aux_Decls_Node
52 -- for the current unit. The declarations are added in the current scope,
53 -- so the caller should push a new scope as required before the call.
55 function Addressable
(V
: Uint
) return Boolean;
56 function Addressable
(V
: Int
) return Boolean;
57 pragma Inline
(Addressable
);
58 -- Returns True if the value of V is the word size of an addressable
59 -- factor of the word size (typically 8, 16, 32 or 64).
61 function Alignment_In_Bits
(E
: Entity_Id
) return Uint
;
62 -- If the alignment of the type or object E is currently known to the
63 -- compiler, then this function returns the alignment value in bits.
64 -- Otherwise Uint_0 is returned, indicating that the alignment of the
65 -- entity is not yet known to the compiler.
67 procedure Apply_Compile_Time_Constraint_Error
70 Reason
: RT_Exception_Code
;
71 Ent
: Entity_Id
:= Empty
;
72 Typ
: Entity_Id
:= Empty
;
73 Loc
: Source_Ptr
:= No_Location
;
74 Rep
: Boolean := True;
75 Warn
: Boolean := False);
76 -- N is a subexpression which will raise constraint error when evaluated
77 -- at runtime. Msg is a message that explains the reason for raising the
78 -- exception. The last character is ? if the message is always a warning,
79 -- even in Ada 95, and is not a ? if the message represents an illegality
80 -- (because of violation of static expression rules) in Ada 95 (but not
81 -- in Ada 83). Typically this routine posts all messages at the Sloc of
82 -- node N. However, if Loc /= No_Location, Loc is the Sloc used to output
83 -- the message. After posting the appropriate message, and if the flag
84 -- Rep is set, this routine replaces the expression with an appropriate
85 -- N_Raise_Constraint_Error node using the given Reason code. This node
86 -- is then marked as being static if the original node is static, but
87 -- sets the flag Raises_Constraint_Error, preventing further evaluation.
88 -- The error message may contain a } or & insertion character. This
89 -- normally references Etype (N), unless the Ent argument is given
90 -- explicitly, in which case it is used instead. The type of the raise
91 -- node that is built is normally Etype (N), but if the Typ parameter
92 -- is present, this is used instead. Warn is normally False. If it is
93 -- True then the message is treated as a warning even though it does
94 -- not end with a ? (this is used when the caller wants to parameterize
95 -- whether an error or warning is given.
97 function Available_Full_View_Of_Component
(T
: Entity_Id
) return Boolean;
98 -- If at the point of declaration an array type has a private or limited
99 -- component, several array operations are not avaiable on the type, and
100 -- the array type is flagged accordingly. If in the immediate scope of
101 -- the array type the component becomes non-private or non-limited, these
102 -- operations become avaiable. This can happen if the scopes of both types
103 -- are open, and the scope of the array is not outside the scope of the
106 procedure Bad_Predicated_Subtype_Use
110 -- This is called when Typ, a predicated subtype, is used in a context
111 -- which does not allow the use of a predicated subtype. Msg is passed
112 -- to Error_Msg_FE to output an appropriate message using N as the
113 -- location, and Typ as the entity. The caller must set up any insertions
114 -- other than the & for the type itself. Note that if Typ is a generic
115 -- actual type, then the message will be output as a warning, and a
116 -- raise Program_Error is inserted using Insert_Action with node N as
117 -- the insertion point. Node N also supplies the source location for
118 -- construction of the raise node. If Typ is NOT a type with predicates
119 -- this call has no effect.
121 function Build_Actual_Subtype
123 N
: Node_Or_Entity_Id
) return Node_Id
;
124 -- Build an anonymous subtype for an entity or expression, using the
125 -- bounds of the entity or the discriminants of the enclosing record.
126 -- T is the type for which the actual subtype is required, and N is either
127 -- a defining identifier, or any subexpression.
129 function Build_Actual_Subtype_Of_Component
131 N
: Node_Id
) return Node_Id
;
132 -- Determine whether a selected component has a type that depends on
133 -- discriminants, and build actual subtype for it if so.
135 function Build_Default_Subtype
137 N
: Node_Id
) return Entity_Id
;
138 -- If T is an unconstrained type with defaulted discriminants, build a
139 -- subtype constrained by the default values, insert the subtype
140 -- declaration in the tree before N, and return the entity of that
141 -- subtype. Otherwise, simply return T.
143 function Build_Discriminal_Subtype_Of_Component
144 (T
: Entity_Id
) return Node_Id
;
145 -- Determine whether a record component has a type that depends on
146 -- discriminants, and build actual subtype for it if so.
148 procedure Build_Elaboration_Entity
(N
: Node_Id
; Spec_Id
: Entity_Id
);
149 -- Given a compilation unit node N, allocate an elaboration counter for
150 -- the compilation unit, and install it in the Elaboration_Entity field
151 -- of Spec_Id, the entity for the compilation unit.
153 procedure Build_Explicit_Dereference
156 -- AI05-139: Names with implicit dereference. If the expression N is a
157 -- reference type and the context imposes the corresponding designated
158 -- type, convert N into N.Disc.all. Such expressions are always over-
159 -- loaded with both interpretations, and the dereference interpretation
160 -- carries the name of the reference discriminant.
162 function Cannot_Raise_Constraint_Error
(Expr
: Node_Id
) return Boolean;
163 -- Returns True if the expression cannot possibly raise Constraint_Error.
164 -- The response is conservative in the sense that a result of False does
165 -- not necessarily mean that CE could be raised, but a response of True
166 -- means that for sure CE cannot be raised.
168 procedure Check_Implicit_Dereference
(Nam
: Node_Id
; Typ
: Entity_Id
);
169 -- AI05-139-2: Accessors and iterators for containers. This procedure
170 -- checks whether T is a reference type, and if so it adds an interprettion
171 -- to Expr whose type is the designated type of the reference_discriminant.
173 procedure Check_Later_Vs_Basic_Declarations
175 During_Parsing
: Boolean);
176 -- If During_Parsing is True, check for misplacement of later vs basic
177 -- declarations in Ada 83. If During_Parsing is False, and the SPARK
178 -- restriction is set, do the same: although SPARK 95 removes the
179 -- distinction between initial and later declarative items, the distinction
180 -- remains in the Examiner (JB01-005). Note that the Examiner does not
181 -- count package declarations in later declarative items.
183 procedure Check_Dynamically_Tagged_Expression
186 Related_Nod
: Node_Id
);
187 -- Check wrong use of dynamically tagged expression
189 procedure Check_Fully_Declared
(T
: Entity_Id
; N
: Node_Id
);
190 -- Verify that the full declaration of type T has been seen. If not, place
191 -- error message on node N. Used in object declarations, type conversions
192 -- and qualified expressions.
194 procedure Check_Nested_Access
(Ent
: Entity_Id
);
195 -- Check whether Ent denotes an entity declared in an uplevel scope, which
196 -- is accessed inside a nested procedure, and set Has_Up_Level_Access flag
197 -- accordingly. This is currently only enabled for VM_Target /= No_VM.
199 procedure Check_Order_Dependence
;
200 -- Examine the actuals in a top-level call to determine whether aliasing
201 -- between two actuals, one of which is writable, can make the call
204 procedure Check_Potentially_Blocking_Operation
(N
: Node_Id
);
205 -- N is one of the statement forms that is a potentially blocking
206 -- operation. If it appears within a protected action, emit warning.
208 procedure Check_Unprotected_Access
211 -- Check whether the expression is a pointer to a protected component,
212 -- and the context is external to the protected operation, to warn against
213 -- a possible unlocked access to data.
215 procedure Check_VMS
(Construct
: Node_Id
);
216 -- Check that this the target is OpenVMS, and if so, return with no effect,
217 -- otherwise post an error noting this can only be used with OpenVMS ports.
218 -- The argument is the construct in question and is used to post the error
221 procedure Collect_Interfaces
223 Ifaces_List
: out Elist_Id
;
224 Exclude_Parents
: Boolean := False;
225 Use_Full_View
: Boolean := True);
226 -- Ada 2005 (AI-251): Collect whole list of abstract interfaces that are
227 -- directly or indirectly implemented by T. Exclude_Parents is used to
228 -- avoid the addition of inherited interfaces to the generated list.
229 -- Use_Full_View is used to collect the interfaces using the full-view
232 procedure Collect_Interface_Components
233 (Tagged_Type
: Entity_Id
;
234 Components_List
: out Elist_Id
);
235 -- Ada 2005 (AI-251): Collect all the tag components associated with the
236 -- secondary dispatch tables of a tagged type.
238 procedure Collect_Interfaces_Info
240 Ifaces_List
: out Elist_Id
;
241 Components_List
: out Elist_Id
;
242 Tags_List
: out Elist_Id
);
243 -- Ada 2005 (AI-251): Collect all the interfaces associated with T plus
244 -- the record component and tag associated with each of these interfaces.
245 -- On exit Ifaces_List, Components_List and Tags_List have the same number
246 -- of elements, and elements at the same position on these tables provide
247 -- information on the same interface type.
249 procedure Collect_Parents
252 Use_Full_View
: Boolean := True);
253 -- Collect all the parents of Typ. Use_Full_View is used to collect them
254 -- using the full-view of private parents (if available).
256 function Collect_Primitive_Operations
(T
: Entity_Id
) return Elist_Id
;
257 -- Called upon type derivation and extension. We scan the declarative part
258 -- in which the type appears, and collect subprograms that have one
259 -- subsidiary subtype of the type. These subprograms can only appear after
262 function Compile_Time_Constraint_Error
265 Ent
: Entity_Id
:= Empty
;
266 Loc
: Source_Ptr
:= No_Location
;
267 Warn
: Boolean := False) return Node_Id
;
268 -- This is similar to Apply_Compile_Time_Constraint_Error in that it
269 -- generates a warning (or error) message in the same manner, but it does
270 -- not replace any nodes. For convenience, the function always returns its
271 -- first argument. The message is a warning if the message ends with ?, or
272 -- we are operating in Ada 83 mode, or the Warn parameter is set to True.
274 procedure Conditional_Delay
(New_Ent
, Old_Ent
: Entity_Id
);
275 -- Sets the Has_Delayed_Freeze flag of New if the Delayed_Freeze flag of
276 -- Old is set and Old has no yet been Frozen (i.e. Is_Frozen is false).
278 function Copy_Parameter_List
(Subp_Id
: Entity_Id
) return List_Id
;
279 -- Utility to create a parameter profile for a new subprogram spec, when
280 -- the subprogram has a body that acts as spec. This is done for some cases
281 -- of inlining, and for private protected ops. Also used to create bodies
282 -- for stubbed subprograms.
284 function Copy_Component_List
286 Loc
: Source_Ptr
) return List_Id
;
287 -- Copy components from record type R_Typ that come from source. Used to
288 -- create a new compatible record type. Loc is the source location assigned
289 -- to the created nodes.
291 function Current_Entity
(N
: Node_Id
) return Entity_Id
;
292 pragma Inline
(Current_Entity
);
293 -- Find the currently visible definition for a given identifier, that is to
294 -- say the first entry in the visibility chain for the Chars of N.
296 function Current_Entity_In_Scope
(N
: Node_Id
) return Entity_Id
;
297 -- Find whether there is a previous definition for identifier N in the
298 -- current scope. Because declarations for a scope are not necessarily
299 -- contiguous (e.g. for packages) the first entry on the visibility chain
300 -- for N is not necessarily in the current scope.
302 function Current_Scope
return Entity_Id
;
303 -- Get entity representing current scope
305 function Current_Subprogram
return Entity_Id
;
306 -- Returns current enclosing subprogram. If Current_Scope is a subprogram,
307 -- then that is what is returned, otherwise the Enclosing_Subprogram of the
308 -- Current_Scope is returned. The returned value is Empty if this is called
309 -- from a library package which is not within any subprogram.
311 function Deepest_Type_Access_Level
(Typ
: Entity_Id
) return Uint
;
312 -- Same as Type_Access_Level, except that if the type is the type of an Ada
313 -- 2012 stand-alone object of an anonymous access type, then return the
314 -- static accesssibility level of the object. In that case, the dynamic
315 -- accessibility level of the object may take on values in a range. The low
316 -- bound of of that range is returned by Type_Access_Level; this function
317 -- yields the high bound of that range. Also differs from Type_Access_Level
318 -- in the case of a descendant of a generic formal type (returns Int'Last
321 function Defining_Entity
(N
: Node_Id
) return Entity_Id
;
322 -- Given a declaration N, returns the associated defining entity. If the
323 -- declaration has a specification, the entity is obtained from the
324 -- specification. If the declaration has a defining unit name, then the
325 -- defining entity is obtained from the defining unit name ignoring any
326 -- child unit prefixes.
328 function Denotes_Discriminant
330 Check_Concurrent
: Boolean := False) return Boolean;
331 -- Returns True if node N is an Entity_Name node for a discriminant. If the
332 -- flag Check_Concurrent is true, function also returns true when N denotes
333 -- the discriminal of the discriminant of a concurrent type. This is needed
334 -- to disable some optimizations on private components of protected types,
335 -- and constraint checks on entry families constrained by discriminants.
337 function Denotes_Same_Object
(A1
, A2
: Node_Id
) return Boolean;
338 function Denotes_Same_Prefix
(A1
, A2
: Node_Id
) return Boolean;
339 -- Functions to detect suspicious overlapping between actuals in a call,
340 -- when one of them is writable. The predicates are those proposed in
341 -- AI05-0144, to detect dangerous order dependence in complex calls.
342 -- I would add a parameter Warn which enables more extensive testing of
343 -- cases as we find appropriate when we are only warning ??? Or perhaps
344 -- return an indication of (Error, Warn, OK) ???
346 function Denotes_Variable
(N
: Node_Id
) return Boolean;
347 -- Returns True if node N denotes a single variable without parentheses
349 function Depends_On_Discriminant
(N
: Node_Id
) return Boolean;
350 -- Returns True if N denotes a discriminant or if N is a range, a subtype
351 -- indication or a scalar subtype where one of the bounds is a
354 function Designate_Same_Unit
356 Name2
: Node_Id
) return Boolean;
357 -- Return true if Name1 and Name2 designate the same unit name; each of
358 -- these names is supposed to be a selected component name, an expanded
359 -- name, a defining program unit name or an identifier.
361 function Dynamic_Accessibility_Level
(Expr
: Node_Id
) return Node_Id
;
362 -- Expr should be an expression of an access type. Builds an integer
363 -- literal except in cases involving anonymous access types where
364 -- accessibility levels are tracked at runtime (access parameters and Ada
365 -- 2012 stand-alone objects).
367 function Effective_Extra_Accessibility
(Id
: Entity_Id
) return Entity_Id
;
368 -- Same as Einfo.Extra_Accessibility except thtat object renames
369 -- are looked through.
371 function Enclosing_CPP_Parent
(Typ
: Entity_Id
) return Entity_Id
;
372 -- Returns the closest ancestor of Typ that is a CPP type.
374 function Enclosing_Generic_Body
375 (N
: Node_Id
) return Node_Id
;
376 -- Returns the Node_Id associated with the innermost enclosing generic
377 -- body, if any. If none, then returns Empty.
379 function Enclosing_Generic_Unit
380 (N
: Node_Id
) return Node_Id
;
381 -- Returns the Node_Id associated with the innermost enclosing generic
382 -- unit, if any. If none, then returns Empty.
384 function Enclosing_Lib_Unit_Entity
return Entity_Id
;
385 -- Returns the entity of enclosing N_Compilation_Unit Node which is the
386 -- root of the current scope (which must not be Standard_Standard, and the
387 -- caller is responsible for ensuring this condition).
389 function Enclosing_Lib_Unit_Node
(N
: Node_Id
) return Node_Id
;
390 -- Returns the enclosing N_Compilation_Unit Node that is the root of a
391 -- subtree containing N.
393 function Enclosing_Package
(E
: Entity_Id
) return Entity_Id
;
394 -- Utility function to return the Ada entity of the package enclosing
395 -- the entity E, if any. Returns Empty if no enclosing package.
397 function Enclosing_Subprogram
(E
: Entity_Id
) return Entity_Id
;
398 -- Utility function to return the Ada entity of the subprogram enclosing
399 -- the entity E, if any. Returns Empty if no enclosing subprogram.
401 procedure Ensure_Freeze_Node
(E
: Entity_Id
);
402 -- Make sure a freeze node is allocated for entity E. If necessary, build
403 -- and initialize a new freeze node and set Has_Delayed_Freeze True for E.
405 procedure Enter_Name
(Def_Id
: Entity_Id
);
406 -- Insert new name in symbol table of current scope with check for
407 -- duplications (error message is issued if a conflict is found).
408 -- Note: Enter_Name is not used for overloadable entities, instead these
409 -- are entered using Sem_Ch6.Enter_Overloadable_Entity.
411 procedure Explain_Limited_Type
(T
: Entity_Id
; N
: Node_Id
);
412 -- This procedure is called after issuing a message complaining about an
413 -- inappropriate use of limited type T. If useful, it adds additional
414 -- continuation lines to the message explaining why type T is limited.
415 -- Messages are placed at node N.
417 procedure Find_Actual
419 Formal
: out Entity_Id
;
421 -- Determines if the node N is an actual parameter of a function of a
422 -- procedure call. If so, then Formal points to the entity for the formal
423 -- (Ekind is E_In_Parameter, E_Out_Parameter, or E_In_Out_Parameter) and
424 -- Call is set to the node for the corresponding call. If the node N is not
425 -- an actual parameter then Formal and Call are set to Empty.
427 function Find_Corresponding_Discriminant
429 Typ
: Entity_Id
) return Entity_Id
;
430 -- Because discriminants may have different names in a generic unit and in
431 -- an instance, they are resolved positionally when possible. A reference
432 -- to a discriminant carries the discriminant that it denotes when it is
433 -- analyzed. Subsequent uses of this id on a different type denotes the
434 -- discriminant at the same position in this new type.
436 procedure Find_Overlaid_Entity
440 -- The node N should be an address representation clause. Determines if
441 -- the target expression is the address of an entity with an optional
442 -- offset. If so, set Ent to the entity and, if there is an offset, set
443 -- Off to True, otherwise to False. If N is not an address representation
444 -- clause, or if it is not possible to determine that the address is of
445 -- this form, then set Ent to Empty.
447 function Find_Parameter_Type
(Param
: Node_Id
) return Entity_Id
;
448 -- Return the type of formal parameter Param as determined by its
451 function Find_Static_Alternative
(N
: Node_Id
) return Node_Id
;
452 -- N is a case statement whose expression is a compile-time value.
453 -- Determine the alternative chosen, so that the code of non-selected
454 -- alternatives, and the warnings that may apply to them, are removed.
456 function Find_Body_Discriminal
457 (Spec_Discriminant
: Entity_Id
) return Entity_Id
;
458 -- Given a discriminant of the record type that implements a task or
459 -- protected type, return the discriminal of the corresponding discriminant
460 -- of the actual concurrent type.
462 function First_Actual
(Node
: Node_Id
) return Node_Id
;
463 -- Node is an N_Function_Call or N_Procedure_Call_Statement node. The
464 -- result returned is the first actual parameter in declaration order
465 -- (not the order of parameters as they appeared in the source, which
466 -- can be quite different as a result of the use of named parameters).
467 -- Empty is returned for a call with no parameters. The procedure for
468 -- iterating through the actuals in declaration order is to use this
469 -- function to find the first actual, and then use Next_Actual to obtain
470 -- the next actual in declaration order. Note that the value returned
471 -- is always the expression (not the N_Parameter_Association nodes,
472 -- even if named association is used).
474 procedure Gather_Components
477 Governed_By
: List_Id
;
479 Report_Errors
: out Boolean);
480 -- The purpose of this procedure is to gather the valid components in a
481 -- record type according to the values of its discriminants, in order to
482 -- validate the components of a record aggregate.
484 -- Typ is the type of the aggregate when its constrained discriminants
485 -- need to be collected, otherwise it is Empty.
487 -- Comp_List is an N_Component_List node.
489 -- Governed_By is a list of N_Component_Association nodes, where each
490 -- choice list contains the name of a discriminant and the expression
491 -- field gives its value. The values of the discriminants governing
492 -- the (possibly nested) variant parts in Comp_List are found in this
493 -- Component_Association List.
495 -- Into is the list where the valid components are appended. Note that
496 -- Into need not be an Empty list. If it's not, components are attached
499 -- Report_Errors is set to True if the values of the discriminants are
502 -- This procedure is also used when building a record subtype. If the
503 -- discriminant constraint of the subtype is static, the components of the
504 -- subtype are only those of the variants selected by the values of the
505 -- discriminants. Otherwise all components of the parent must be included
506 -- in the subtype for semantic analysis.
508 function Get_Actual_Subtype
(N
: Node_Id
) return Entity_Id
;
509 -- Given a node for an expression, obtain the actual subtype of the
510 -- expression. In the case of a parameter where the formal is an
511 -- unconstrained array or discriminated type, this will be the previously
512 -- constructed subtype of the actual. Note that this is not quite the
513 -- "Actual Subtype" of the RM, since it is always a constrained type, i.e.
514 -- it is the subtype of the value of the actual. The actual subtype is also
515 -- returned in other cases where it has already been constructed for an
516 -- object. Otherwise the expression type is returned unchanged, except for
517 -- the case of an unconstrained array type, where an actual subtype is
518 -- created, using Insert_Actions if necessary to insert any associated
521 function Get_Actual_Subtype_If_Available
(N
: Node_Id
) return Entity_Id
;
522 -- This is like Get_Actual_Subtype, except that it never constructs an
523 -- actual subtype. If an actual subtype is already available, i.e. the
524 -- Actual_Subtype field of the corresponding entity is set, then it is
525 -- returned. Otherwise the Etype of the node is returned.
527 function Get_Body_From_Stub
(N
: Node_Id
) return Node_Id
;
528 -- Return the body node for a stub (subprogram or package)
530 function Get_Default_External_Name
(E
: Node_Or_Entity_Id
) return Node_Id
;
531 -- This is used to construct the string literal node representing a
532 -- default external name, i.e. one that is constructed from the name of an
533 -- entity, or (in the case of extended DEC import/export pragmas, an
534 -- identifier provided as the external name. Letters in the name are
535 -- according to the setting of Opt.External_Name_Default_Casing.
537 function Get_Enclosing_Object
(N
: Node_Id
) return Entity_Id
;
538 -- If expression N references a part of an object, return this object.
539 -- Otherwise return Empty. Expression N should have been resolved already.
541 function Get_Ensures_From_Test_Case_Pragma
(N
: Node_Id
) return Node_Id
;
542 -- Return the Ensures component of Test_Case pragma N, or Empty otherwise
544 function Get_Generic_Entity
(N
: Node_Id
) return Entity_Id
;
545 -- Returns the true generic entity in an instantiation. If the name in the
546 -- instantiation is a renaming, the function returns the renamed generic.
548 procedure Get_Index_Bounds
(N
: Node_Id
; L
, H
: out Node_Id
);
549 -- This procedure assigns to L and H respectively the values of the low and
550 -- high bounds of node N, which must be a range, subtype indication, or the
551 -- name of a scalar subtype. The result in L, H may be set to Error if
552 -- there was an earlier error in the range.
554 function Get_Enum_Lit_From_Pos
557 Loc
: Source_Ptr
) return Node_Id
;
558 -- This function returns an identifier denoting the E_Enumeration_Literal
559 -- entity for the specified value from the enumeration type or subtype T.
560 -- The second argument is the Pos value, which is assumed to be in range.
561 -- The third argument supplies a source location for constructed nodes
562 -- returned by this function.
564 procedure Get_Library_Unit_Name_String
(Decl_Node
: Node_Id
);
565 -- Retrieve the fully expanded name of the library unit declared by
566 -- Decl_Node into the name buffer.
568 function Get_Name_Entity_Id
(Id
: Name_Id
) return Entity_Id
;
569 pragma Inline
(Get_Name_Entity_Id
);
570 -- An entity value is associated with each name in the name table. The
571 -- Get_Name_Entity_Id function fetches the Entity_Id of this entity, which
572 -- is the innermost visible entity with the given name. See the body of
573 -- Sem_Ch8 for further details on handling of entity visibility.
575 function Get_Name_From_Test_Case_Pragma
(N
: Node_Id
) return String_Id
;
576 -- Return the Name component of Test_Case pragma N
578 function Get_Pragma_Id
(N
: Node_Id
) return Pragma_Id
;
579 pragma Inline
(Get_Pragma_Id
);
580 -- Obtains the Pragma_Id from the Chars field of Pragma_Identifier (N)
582 function Get_Referenced_Object
(N
: Node_Id
) return Node_Id
;
583 -- Given a node, return the renamed object if the node represents a renamed
584 -- object, otherwise return the node unchanged. The node may represent an
585 -- arbitrary expression.
587 function Get_Renamed_Entity
(E
: Entity_Id
) return Entity_Id
;
588 -- Given an entity for an exception, package, subprogram or generic unit,
589 -- returns the ultimately renamed entity if this is a renaming. If this is
590 -- not a renamed entity, returns its argument. It is an error to call this
591 -- with any other kind of entity.
593 function Get_Requires_From_Test_Case_Pragma
(N
: Node_Id
) return Node_Id
;
594 -- Return the Requires component of Test_Case pragma N, or Empty otherwise
596 function Get_Subprogram_Entity
(Nod
: Node_Id
) return Entity_Id
;
597 -- Nod is either a procedure call statement, or a function call, or an
598 -- accept statement node. This procedure finds the Entity_Id of the related
599 -- subprogram or entry and returns it, or if no subprogram can be found,
602 function Get_Subprogram_Body
(E
: Entity_Id
) return Node_Id
;
603 -- Given the entity for a subprogram (E_Function or E_Procedure), return
604 -- the corresponding N_Subprogram_Body node. If the corresponding body
605 -- is missing (as for an imported subprogram), return Empty.
607 function Get_Task_Body_Procedure
(E
: Entity_Id
) return Node_Id
;
608 pragma Inline
(Get_Task_Body_Procedure
);
609 -- Given an entity for a task type or subtype, retrieves the
610 -- Task_Body_Procedure field from the corresponding task type declaration.
612 function Has_Access_Values
(T
: Entity_Id
) return Boolean;
613 -- Returns true if type or subtype T is an access type, or has a component
614 -- (at any recursive level) that is an access type. This is a conservative
615 -- predicate, if it is not known whether or not T contains access values
616 -- (happens for generic formals in some cases), then False is returned.
617 -- Note that tagged types return False. Even though the tag is implemented
618 -- as an access type internally, this function tests only for access types
619 -- known to the programmer. See also Has_Tagged_Component.
621 type Alignment_Result
is (Known_Compatible
, Unknown
, Known_Incompatible
);
622 -- Result of Has_Compatible_Alignment test, description found below. Note
623 -- that the values are arranged in increasing order of problematicness.
625 function Has_Compatible_Alignment
627 Expr
: Node_Id
) return Alignment_Result
;
628 -- Obj is an object entity, and expr is a node for an object reference. If
629 -- the alignment of the object referenced by Expr is known to be compatible
630 -- with the alignment of Obj (i.e. is larger or the same), then the result
631 -- is Known_Compatible. If the alignment of the object referenced by Expr
632 -- is known to be less than the alignment of Obj, then Known_Incompatible
633 -- is returned. If neither condition can be reliably established at compile
634 -- time, then Unknown is returned. This is used to determine if alignment
635 -- checks are required for address clauses, and also whether copies must
636 -- be made when objects are passed by reference.
638 -- Note: Known_Incompatible does not mean that at run time the alignment
639 -- of Expr is known to be wrong for Obj, just that it can be determined
640 -- that alignments have been explicitly or implicitly specified which are
641 -- incompatible (whereas Unknown means that even this is not known). The
642 -- appropriate reaction of a caller to Known_Incompatible is to treat it as
643 -- Unknown, but issue a warning that there may be an alignment error.
645 function Has_Declarations
(N
: Node_Id
) return Boolean;
646 -- Determines if the node can have declarations
648 function Has_Discriminant_Dependent_Constraint
649 (Comp
: Entity_Id
) return Boolean;
650 -- Returns True if and only if Comp has a constrained subtype that depends
651 -- on a discriminant.
653 function Has_Infinities
(E
: Entity_Id
) return Boolean;
654 -- Determines if the range of the floating-point type E includes
655 -- infinities. Returns False if E is not a floating-point type.
657 function Has_Interfaces
659 Use_Full_View
: Boolean := True) return Boolean;
660 -- Where T is a concurrent type or a record type, returns true if T covers
661 -- any abstract interface types. In case of private types the argument
662 -- Use_Full_View controls if the check is done using its full view (if
665 function Has_Null_Exclusion
(N
: Node_Id
) return Boolean;
666 -- Determine whether node N has a null exclusion
668 function Has_Overriding_Initialize
(T
: Entity_Id
) return Boolean;
669 -- Predicate to determine whether a controlled type has a user-defined
670 -- Initialize primitive (and, in Ada 2012, whether that primitive is
671 -- non-null), which causes the type to not have preelaborable
674 function Has_Preelaborable_Initialization
(E
: Entity_Id
) return Boolean;
675 -- Return True iff type E has preelaborable initialization as defined in
676 -- Ada 2005 (see AI-161 for details of the definition of this attribute).
678 function Has_Private_Component
(Type_Id
: Entity_Id
) return Boolean;
679 -- Check if a type has a (sub)component of a private type that has not
680 -- yet received a full declaration.
682 function Has_Static_Array_Bounds
(Typ
: Node_Id
) return Boolean;
683 -- Return whether an array type has static bounds
685 function Has_Stream
(T
: Entity_Id
) return Boolean;
686 -- Tests if type T is derived from Ada.Streams.Root_Stream_Type, or in the
687 -- case of a composite type, has a component for which this predicate is
688 -- True, and if so returns True. Otherwise a result of False means that
689 -- there is no Stream type in sight. For a private type, the test is
690 -- applied to the underlying type (or returns False if there is no
693 function Has_Suffix
(E
: Entity_Id
; Suffix
: Character) return Boolean;
694 -- Returns true if the last character of E is Suffix. Used in Assertions.
696 function Add_Suffix
(E
: Entity_Id
; Suffix
: Character) return Name_Id
;
697 -- Returns the name of E adding Suffix
699 function Remove_Suffix
(E
: Entity_Id
; Suffix
: Character) return Name_Id
;
700 -- Returns the name of E without Suffix
702 function Has_Tagged_Component
(Typ
: Entity_Id
) return Boolean;
703 -- Returns True if Typ is a composite type (array or record) which is
704 -- either itself a tagged type, or has a component (recursively) which is
705 -- a tagged type. Returns False for non-composite type, or if no tagged
706 -- component is present. This function is used to check if "=" has to be
707 -- expanded into a bunch component comparisons.
709 function Implementation_Kind
(Subp
: Entity_Id
) return Name_Id
;
710 -- Subp is a subprogram marked with pragma Implemented. Return the specific
711 -- implementation requirement which the pragma imposes. The return value is
712 -- either Name_By_Any, Name_By_Entry or Name_By_Protected_Procedure.
714 function Implements_Interface
715 (Typ_Ent
: Entity_Id
;
716 Iface_Ent
: Entity_Id
;
717 Exclude_Parents
: Boolean := False) return Boolean;
718 -- Returns true if the Typ_Ent implements interface Iface_Ent
720 function In_Instance
return Boolean;
721 -- Returns True if the current scope is within a generic instance
723 function In_Instance_Body
return Boolean;
724 -- Returns True if current scope is within the body of an instance, where
725 -- several semantic checks (e.g. accessibility checks) are relaxed.
727 function In_Instance_Not_Visible
return Boolean;
728 -- Returns True if current scope is with the private part or the body of
729 -- an instance. Other semantic checks are suppressed in this context.
731 function In_Instance_Visible_Part
return Boolean;
732 -- Returns True if current scope is within the visible part of a package
733 -- instance, where several additional semantic checks apply.
735 function In_Package_Body
return Boolean;
736 -- Returns True if current scope is within a package body
738 function In_Parameter_Specification
(N
: Node_Id
) return Boolean;
739 -- Returns True if node N belongs to a parameter specification
741 function In_Subprogram_Or_Concurrent_Unit
return Boolean;
742 -- Determines if the current scope is within a subprogram compilation unit
743 -- (inside a subprogram declaration, subprogram body, or generic
744 -- subprogram declaration) or within a task or protected body. The test is
745 -- for appearing anywhere within such a construct (that is it does not need
746 -- to be directly within).
748 function In_Visible_Part
(Scope_Id
: Entity_Id
) return Boolean;
749 -- Determine whether a declaration occurs within the visible part of a
750 -- package specification. The package must be on the scope stack, and the
751 -- corresponding private part must not.
753 function Incomplete_Or_Private_View
(Typ
: Entity_Id
) return Entity_Id
;
754 -- Given the entity of a type, retrieve the incomplete or private view of
755 -- the same type. Note that Typ may not have a partial view to begin with,
756 -- in that case the function returns Empty.
758 procedure Insert_Explicit_Dereference
(N
: Node_Id
);
759 -- In a context that requires a composite or subprogram type and where a
760 -- prefix is an access type, rewrite the access type node N (which is the
761 -- prefix, e.g. of an indexed component) as an explicit dereference.
763 procedure Inspect_Deferred_Constant_Completion
(Decls
: List_Id
);
764 -- Examine all deferred constants in the declaration list Decls and check
765 -- whether they have been completed by a full constant declaration or an
766 -- Import pragma. Emit the error message if that is not the case.
768 function Is_Actual_Out_Parameter
(N
: Node_Id
) return Boolean;
769 -- Determines if N is an actual parameter of out mode in a subprogram call
771 function Is_Actual_Parameter
(N
: Node_Id
) return Boolean;
772 -- Determines if N is an actual parameter in a subprogram call
774 function Is_Actual_Tagged_Parameter
(N
: Node_Id
) return Boolean;
775 -- Determines if N is an actual parameter of a formal of tagged type in a
778 function Is_Aliased_View
(Obj
: Node_Id
) return Boolean;
779 -- Determine if Obj is an aliased view, i.e. the name of an object to which
780 -- 'Access or 'Unchecked_Access can apply. Note that this routine uses the
781 -- rules of the language, it does not take into account the restriction
782 -- No_Implicit_Aliasing, so it can return True if the restriction is active
783 -- and Obj violates the restriction. The caller is responsible for calling
784 -- Restrict.Check_No_Implicit_Aliasing if True is returned, but there is a
785 -- requirement for obeying the restriction in the call context.
787 function Is_Ancestor_Package
789 E2
: Entity_Id
) return Boolean;
790 -- Determine whether package E1 is an ancestor of E2
792 function Is_Atomic_Object
(N
: Node_Id
) return Boolean;
793 -- Determines if the given node denotes an atomic object in the sense of
794 -- the legality checks described in RM C.6(12).
796 function Is_Bounded_String
(T
: Entity_Id
) return Boolean;
797 -- True if T is a bounded string type. Used to make sure "=" composes
798 -- properly for bounded string types.
800 function Is_Controlling_Limited_Procedure
801 (Proc_Nam
: Entity_Id
) return Boolean;
802 -- Ada 2005 (AI-345): Determine whether Proc_Nam is a primitive procedure
803 -- of a limited interface with a controlling first parameter.
805 function Is_CPP_Constructor_Call
(N
: Node_Id
) return Boolean;
806 -- Returns True if N is a call to a CPP constructor
808 function Is_Dependent_Component_Of_Mutable_Object
809 (Object
: Node_Id
) return Boolean;
810 -- Returns True if Object is the name of a subcomponent that depends on
811 -- discriminants of a variable whose nominal subtype is unconstrained and
812 -- not indefinite, and the variable is not aliased. Otherwise returns
813 -- False. The nodes passed to this function are assumed to denote objects.
815 function Is_Dereferenced
(N
: Node_Id
) return Boolean;
816 -- N is a subexpression node of an access type. This function returns true
817 -- if N appears as the prefix of a node that does a dereference of the
818 -- access value (selected/indexed component, explicit dereference or a
819 -- slice), and false otherwise.
821 function Is_Descendent_Of
(T1
: Entity_Id
; T2
: Entity_Id
) return Boolean;
822 -- Returns True if type T1 is a descendent of type T2, and false otherwise.
823 -- This is the RM definition, a type is a descendent of another type if it
824 -- is the same type or is derived from a descendent of the other type.
826 function Is_Concurrent_Interface
(T
: Entity_Id
) return Boolean;
827 -- First determine whether type T is an interface and then check whether
828 -- it is of protected, synchronized or task kind.
830 function Is_Expression_Function
(Subp
: Entity_Id
) return Boolean;
831 -- Predicate to determine whether a function entity comes from a rewritten
832 -- expression function, and should be inlined unconditionally.
834 function Is_False
(U
: Uint
) return Boolean;
835 pragma Inline
(Is_False
);
836 -- The argument is a Uint value which is the Boolean'Pos value of a Boolean
837 -- operand (i.e. is either 0 for False, or 1 for True). This function tests
838 -- if it is False (i.e. zero).
840 function Is_Fixed_Model_Number
(U
: Ureal
; T
: Entity_Id
) return Boolean;
841 -- Returns True iff the number U is a model number of the fixed-point type
842 -- T, i.e. if it is an exact multiple of Small.
844 function Is_Fully_Initialized_Type
(Typ
: Entity_Id
) return Boolean;
845 -- Typ is a type entity. This function returns true if this type is fully
846 -- initialized, meaning that an object of the type is fully initialized.
847 -- Note that initialization resulting from use of pragma Normalized_Scalars
848 -- does not count. Note that this is only used for the purpose of issuing
849 -- warnings for objects that are potentially referenced uninitialized. This
850 -- means that the result returned is not crucial, but should err on the
851 -- side of thinking things are fully initialized if it does not know.
853 function Is_Inherited_Operation
(E
: Entity_Id
) return Boolean;
854 -- E is a subprogram. Return True is E is an implicit operation inherited
855 -- by a derived type declaration.
857 function Is_Inherited_Operation_For_Type
859 Typ
: Entity_Id
) return Boolean;
860 -- E is a subprogram. Return True is E is an implicit operation inherited
861 -- by the derived type declaration for type Typ.
863 function Is_Iterator
(Typ
: Entity_Id
) return Boolean;
864 -- AI05-0139-2: Check whether Typ is one of the predefined interfaces in
865 -- Ada.Iterator_Interfaces, or it is derived from one.
867 function Is_LHS
(N
: Node_Id
) return Boolean;
868 -- Returns True iff N is used as Name in an assignment statement
870 function Is_Library_Level_Entity
(E
: Entity_Id
) return Boolean;
871 -- A library-level declaration is one that is accessible from Standard,
872 -- i.e. a library unit or an entity declared in a library package.
874 function Is_Limited_Class_Wide_Type
(Typ
: Entity_Id
) return Boolean;
875 -- Determine whether a given arbitrary type is a limited class-wide type
877 function Is_Local_Variable_Reference
(Expr
: Node_Id
) return Boolean;
878 -- Determines whether Expr is a reference to a variable or IN OUT mode
879 -- parameter of the current enclosing subprogram.
880 -- Why are OUT parameters not considered here ???
882 function Is_Object_Reference
(N
: Node_Id
) return Boolean;
883 -- Determines if the tree referenced by N represents an object. Both
884 -- variable and constant objects return True (compare Is_Variable).
886 function Is_OK_Variable_For_Out_Formal
(AV
: Node_Id
) return Boolean;
887 -- Used to test if AV is an acceptable formal for an OUT or IN OUT formal.
888 -- Note that the Is_Variable function is not quite the right test because
889 -- this is a case in which conversions whose expression is a variable (in
890 -- the Is_Variable sense) with a non-tagged type target are considered view
891 -- conversions and hence variables.
893 function Is_Partially_Initialized_Type
895 Include_Implicit
: Boolean := True) return Boolean;
896 -- Typ is a type entity. This function returns true if this type is partly
897 -- initialized, meaning that an object of the type is at least partly
898 -- initialized (in particular in the record case, that at least one
899 -- component has an initialization expression). Note that initialization
900 -- resulting from the use of pragma Normalized_Scalars does not count.
901 -- Include_Implicit controls whether implicit initialization of access
902 -- values to null, and of discriminant values, is counted as making the
903 -- type be partially initialized. For the default setting of True, these
904 -- implicit cases do count, and discriminated types or types containing
905 -- access values not explicitly initialized will return True. Otherwise
906 -- if Include_Implicit is False, these cases do not count as making the
907 -- type be partially initialized.
909 function Is_Potentially_Persistent_Type
(T
: Entity_Id
) return Boolean;
910 -- Determines if type T is a potentially persistent type. A potentially
911 -- persistent type is defined (recursively) as a scalar type, a non-tagged
912 -- record whose components are all of a potentially persistent type, or an
913 -- array with all static constraints whose component type is potentially
914 -- persistent. A private type is potentially persistent if the full type
915 -- is potentially persistent.
917 function Is_Protected_Self_Reference
(N
: Node_Id
) return Boolean;
918 -- Return True if node N denotes a protected type name which represents
919 -- the current instance of a protected object according to RM 9.4(21/2).
921 function Is_RCI_Pkg_Spec_Or_Body
(Cunit
: Node_Id
) return Boolean;
922 -- Return True if a compilation unit is the specification or the
923 -- body of a remote call interface package.
925 function Is_Remote_Access_To_Class_Wide_Type
(E
: Entity_Id
) return Boolean;
926 -- Return True if E is a remote access-to-class-wide type
928 function Is_Remote_Access_To_Subprogram_Type
(E
: Entity_Id
) return Boolean;
929 -- Return True if E is a remote access to subprogram type
931 function Is_Remote_Call
(N
: Node_Id
) return Boolean;
932 -- Return True if N denotes a potentially remote call
934 function Is_Renamed_Entry
(Proc_Nam
: Entity_Id
) return Boolean;
935 -- Return True if Proc_Nam is a procedure renaming of an entry
937 function Is_Reversible_Iterator
(Typ
: Entity_Id
) return Boolean;
938 -- AI05-0139-2: Check whether Typ is derived from the predefined interface
939 -- Ada.Iterator_Interfaces.Reversible_Iterator.
941 function Is_Selector_Name
(N
: Node_Id
) return Boolean;
942 -- Given an N_Identifier node N, determines if it is a Selector_Name.
943 -- As described in Sinfo, Selector_Names are special because they
944 -- represent use of the N_Identifier node for a true identifier, when
945 -- normally such nodes represent a direct name.
947 function Is_SPARK_Initialization_Expr
(N
: Node_Id
) return Boolean;
948 -- Determines if the tree referenced by N represents an initialization
949 -- expression in SPARK, suitable for initializing an object in an object
952 function Is_SPARK_Object_Reference
(N
: Node_Id
) return Boolean;
953 -- Determines if the tree referenced by N represents an object in SPARK
955 function Is_Statement
(N
: Node_Id
) return Boolean;
956 pragma Inline
(Is_Statement
);
957 -- Check if the node N is a statement node. Note that this includes
958 -- the case of procedure call statements (unlike the direct use of
959 -- the N_Statement_Other_Than_Procedure_Call subtype from Sinfo).
960 -- Note that a label is *not* a statement, and will return False.
962 function Is_Subprogram_Stub_Without_Prior_Declaration
963 (N
: Node_Id
) return Boolean;
964 -- Return True if N is a subprogram stub with no prior subprogram
967 function Is_Synchronized_Tagged_Type
(E
: Entity_Id
) return Boolean;
968 -- Returns True if E is a synchronized tagged type (AARM 3.9.4 (6/2))
970 function Is_Transfer
(N
: Node_Id
) return Boolean;
971 -- Returns True if the node N is a statement which is known to cause an
972 -- unconditional transfer of control at runtime, i.e. the following
973 -- statement definitely will not be executed.
975 function Is_True
(U
: Uint
) return Boolean;
976 pragma Inline
(Is_True
);
977 -- The argument is a Uint value which is the Boolean'Pos value of a Boolean
978 -- operand (i.e. is either 0 for False, or 1 for True). This function tests
979 -- if it is True (i.e. non-zero).
981 function Is_Universal_Numeric_Type
(T
: Entity_Id
) return Boolean;
982 pragma Inline
(Is_Universal_Numeric_Type
);
983 -- True if T is Universal_Integer or Universal_Real
985 function Is_Value_Type
(T
: Entity_Id
) return Boolean;
986 -- Returns true if type T represents a value type. This is only relevant to
987 -- CIL, will always return false for other targets. A value type is a CIL
988 -- object that is accessed directly, as opposed to the other CIL objects
989 -- that are accessed through managed pointers.
991 function Is_VMS_Operator
(Op
: Entity_Id
) return Boolean;
992 -- Determine whether an operator is one of the intrinsics defined
993 -- in the DEC system extension.
995 function Is_Delegate
(T
: Entity_Id
) return Boolean;
996 -- Returns true if type T represents a delegate. A Delegate is the CIL
997 -- object used to represent access-to-subprogram types. This is only
998 -- relevant to CIL, will always return false for other targets.
1000 function Is_Variable
1002 Use_Original_Node
: Boolean := True) return Boolean;
1003 -- Determines if the tree referenced by N represents a variable, i.e. can
1004 -- appear on the left side of an assignment. There is one situation (formal
1005 -- parameters) in which non-tagged type conversions are also considered
1006 -- variables, but Is_Variable returns False for such cases, since it has
1007 -- no knowledge of the context. Note that this is the point at which
1008 -- Assignment_OK is checked, and True is returned for any tree thus marked.
1009 -- Use_Original_Node is used to perform the test on Original_Node (N). By
1010 -- default is True since this routine is commonly invoked as part of the
1011 -- semantic analysis and it must not be disturbed by the rewriten nodes.
1013 function Is_Visibly_Controlled
(T
: Entity_Id
) return Boolean;
1014 -- Check whether T is derived from a visibly controlled type. This is true
1015 -- if the root type is declared in Ada.Finalization. If T is derived
1016 -- instead from a private type whose full view is controlled, an explicit
1017 -- Initialize/Adjust/Finalize subprogram does not override the inherited
1020 function Is_Volatile_Object
(N
: Node_Id
) return Boolean;
1021 -- Determines if the given node denotes an volatile object in the sense of
1022 -- the legality checks described in RM C.6(12). Note that the test here is
1023 -- for something actually declared as volatile, not for an object that gets
1024 -- treated as volatile (see Einfo.Treat_As_Volatile).
1026 function Itype_Has_Declaration
(Id
: Entity_Id
) return Boolean;
1027 -- Applies to Itypes. True if the Itype is attached to a declaration for
1028 -- the type through its Parent field, which may or not be present in the
1031 procedure Kill_Current_Values
(Last_Assignment_Only
: Boolean := False);
1032 -- This procedure is called to clear all constant indications from all
1033 -- entities in the current scope and in any parent scopes if the current
1034 -- scope is a block or a package (and that recursion continues to the top
1035 -- scope that is not a block or a package). This is used when the
1036 -- sequential flow-of-control assumption is violated (occurrence of a
1037 -- label, head of a loop, or start of an exception handler). The effect of
1038 -- the call is to clear the Constant_Value field (but we do not need to
1039 -- clear the Is_True_Constant flag, since that only gets reset if there
1040 -- really is an assignment somewhere in the entity scope). This procedure
1041 -- also calls Kill_All_Checks, since this is a special case of needing to
1042 -- forget saved values. This procedure also clears the Is_Known_Null and
1043 -- Is_Known_Non_Null and Is_Known_Valid flags in variables, constants or
1044 -- parameters since these are also not known to be trustable any more.
1046 -- The Last_Assignment_Only flag is set True to clear only Last_Assignment
1047 -- fields and leave other fields unchanged. This is used when we encounter
1048 -- an unconditional flow of control change (return, goto, raise). In such
1049 -- cases we don't need to clear the current values, since it may be that
1050 -- the flow of control change occurs in a conditional context, and if it
1051 -- is not taken, then it is just fine to keep the current values. But the
1052 -- Last_Assignment field is different, if we have a sequence assign-to-v,
1053 -- conditional-return, assign-to-v, we do not want to complain that the
1054 -- second assignment clobbers the first.
1056 procedure Kill_Current_Values
1058 Last_Assignment_Only
: Boolean := False);
1059 -- This performs the same processing as described above for the form with
1060 -- no argument, but for the specific entity given. The call has no effect
1061 -- if the entity Ent is not for an object. Last_Assignment_Only has the
1062 -- same meaning as for the call with no Ent.
1064 procedure Kill_Size_Check_Code
(E
: Entity_Id
);
1065 -- Called when an address clause or pragma Import is applied to an entity.
1066 -- If the entity is a variable or a constant, and size check code is
1067 -- present, this size check code is killed, since the object will not be
1068 -- allocated by the program.
1070 function Known_To_Be_Assigned
(N
: Node_Id
) return Boolean;
1071 -- The node N is an entity reference. This function determines whether the
1072 -- reference is for sure an assignment of the entity, returning True if
1073 -- so. This differs from May_Be_Lvalue in that it defaults in the other
1074 -- direction. Cases which may possibly be assignments but are not known to
1075 -- be may return True from May_Be_Lvalue, but False from this function.
1077 function Last_Source_Statement
(HSS
: Node_Id
) return Node_Id
;
1078 -- HSS is a handled statement sequence. This function returns the last
1079 -- statement in Statements (HSS) that has Comes_From_Source set. If no
1080 -- such statement exists, Empty is returned.
1082 function Make_Simple_Return_Statement
1084 Expression
: Node_Id
:= Empty
) return Node_Id
1085 renames Make_Return_Statement
;
1086 -- See Sinfo. We rename Make_Return_Statement to the correct Ada 2005
1087 -- terminology here. Clients should use Make_Simple_Return_Statement.
1089 function Matching_Static_Array_Bounds
1091 R_Typ
: Node_Id
) return Boolean;
1092 -- L_Typ and R_Typ are two array types. Returns True when they have the
1093 -- same number of dimensions, and the same static bounds for each index
1096 Make_Return_Statement
: constant := -2 ** 33;
1097 -- Attempt to prevent accidental uses of Make_Return_Statement. If this
1098 -- and the one in Nmake are both potentially use-visible, it will cause
1099 -- a compilation error. Note that type and value are irrelevant.
1101 N_Return_Statement
: constant := -2 ** 33;
1102 -- Attempt to prevent accidental uses of N_Return_Statement; similar to
1103 -- Make_Return_Statement above.
1105 procedure Mark_Coextensions
(Context_Nod
: Node_Id
; Root_Nod
: Node_Id
);
1106 -- Given a node which designates the context of analysis and an origin in
1107 -- the tree, traverse from Root_Nod and mark all allocators as either
1108 -- dynamic or static depending on Context_Nod. Any erroneous marking is
1109 -- cleaned up during resolution.
1111 function May_Be_Lvalue
(N
: Node_Id
) return Boolean;
1112 -- Determines if N could be an lvalue (e.g. an assignment left hand side).
1113 -- An lvalue is defined as any expression which appears in a context where
1114 -- a name is required by the syntax, and the identity, rather than merely
1115 -- the value of the node is needed (for example, the prefix of an Access
1116 -- attribute is in this category). Note that, as implied by the name, this
1117 -- test is conservative. If it cannot be sure that N is NOT an lvalue, then
1118 -- it returns True. It tries hard to get the answer right, but it is hard
1119 -- to guarantee this in all cases. Note that it is more possible to give
1120 -- correct answer if the tree is fully analyzed.
1122 function Must_Inline
(Subp
: Entity_Id
) return Boolean;
1123 -- Return true if Subp must be inlined by the frontend
1125 function Needs_One_Actual
(E
: Entity_Id
) return Boolean;
1126 -- Returns True if a function has defaults for all but its first
1127 -- formal. Used in Ada 2005 mode to solve the syntactic ambiguity that
1128 -- results from an indexing of a function call written in prefix form.
1130 function New_Copy_List_Tree
(List
: List_Id
) return List_Id
;
1131 -- Copy recursively an analyzed list of nodes. Uses New_Copy_Tree defined
1132 -- below. As for New_Copy_Tree, it is illegal to attempt to copy extended
1133 -- nodes (entities) either directly or indirectly using this function.
1135 function New_Copy_Tree
1137 Map
: Elist_Id
:= No_Elist
;
1138 New_Sloc
: Source_Ptr
:= No_Location
;
1139 New_Scope
: Entity_Id
:= Empty
) return Node_Id
;
1140 -- Given a node that is the root of a subtree, Copy_Tree copies the entire
1141 -- syntactic subtree, including recursively any descendents whose parent
1142 -- field references a copied node (descendents not linked to a copied node
1143 -- by the parent field are not copied, instead the copied tree references
1144 -- the same descendent as the original in this case, which is appropriate
1145 -- for non-syntactic fields such as Etype). The parent pointers in the
1146 -- copy are properly set. Copy_Tree (Empty/Error) returns Empty/Error.
1147 -- The one exception to the rule of not copying semantic fields is that
1148 -- any implicit types attached to the subtree are duplicated, so that
1149 -- the copy contains a distinct set of implicit type entities. Thus this
1150 -- function is used when it is necessary to duplicate an analyzed tree,
1151 -- declared in the same or some other compilation unit. This function is
1152 -- declared here rather than in atree because it uses semantic information
1153 -- in particular concerning the structure of itypes and the generation of
1156 -- The Map argument, if set to a non-empty Elist, specifies a set of
1157 -- mappings to be applied to entities in the tree. The map has the form:
1160 -- new entity to replace references to entity 1
1162 -- new entity to replace references to entity 2
1165 -- The call destroys the contents of Map in this case
1167 -- The parameter New_Sloc, if set to a value other than No_Location, is
1168 -- used as the Sloc value for all nodes in the new copy. If New_Sloc is
1169 -- set to its default value No_Location, then the Sloc values of the
1170 -- nodes in the copy are simply copied from the corresponding original.
1172 -- The Comes_From_Source indication is unchanged if New_Sloc is set to
1173 -- the default No_Location value, but is reset if New_Sloc is given, since
1174 -- in this case the result clearly is neither a source node or an exact
1175 -- copy of a source node.
1177 -- The parameter New_Scope, if set to a value other than Empty, is the
1178 -- value to use as the Scope for any Itypes that are copied. The most
1179 -- typical value for this parameter, if given, is Current_Scope.
1181 function New_External_Entity
1182 (Kind
: Entity_Kind
;
1183 Scope_Id
: Entity_Id
;
1184 Sloc_Value
: Source_Ptr
;
1185 Related_Id
: Entity_Id
;
1187 Suffix_Index
: Nat
:= 0;
1188 Prefix
: Character := ' ') return Entity_Id
;
1189 -- This function creates an N_Defining_Identifier node for an internal
1190 -- created entity, such as an implicit type or subtype, or a record
1191 -- initialization procedure. The entity name is constructed with a call
1192 -- to New_External_Name (Related_Id, Suffix, Suffix_Index, Prefix), so
1193 -- that the generated name may be referenced as a public entry, and the
1194 -- Is_Public flag is set if needed (using Set_Public_Status). If the
1195 -- entity is for a type or subtype, the size/align fields are initialized
1196 -- to unknown (Uint_0).
1198 function New_Internal_Entity
1199 (Kind
: Entity_Kind
;
1200 Scope_Id
: Entity_Id
;
1201 Sloc_Value
: Source_Ptr
;
1202 Id_Char
: Character) return Entity_Id
;
1203 -- This function is similar to New_External_Entity, except that the
1204 -- name is constructed by New_Internal_Name (Id_Char). This is used
1205 -- when the resulting entity does not have to be referenced as a
1206 -- public entity (and in this case Is_Public is not set).
1208 procedure Next_Actual
(Actual_Id
: in out Node_Id
);
1209 pragma Inline
(Next_Actual
);
1210 -- Next_Actual (N) is equivalent to N := Next_Actual (N). Note that we
1211 -- inline this procedural form, but not the functional form that follows.
1213 function Next_Actual
(Actual_Id
: Node_Id
) return Node_Id
;
1214 -- Find next actual parameter in declaration order. As described for
1215 -- First_Actual, this is the next actual in the declaration order, not
1216 -- the call order, so this does not correspond to simply taking the
1217 -- next entry of the Parameter_Associations list. The argument is an
1218 -- actual previously returned by a call to First_Actual or Next_Actual.
1219 -- Note that the result produced is always an expression, not a parameter
1220 -- association node, even if named notation was used.
1222 procedure Normalize_Actuals
1226 Success
: out Boolean);
1227 -- Reorders lists of actuals according to names of formals, value returned
1228 -- in Success indicates success of reordering. For more details, see body.
1229 -- Errors are reported only if Report is set to True.
1231 procedure Note_Possible_Modification
(N
: Node_Id
; Sure
: Boolean);
1232 -- This routine is called if the sub-expression N maybe the target of
1233 -- an assignment (e.g. it is the left side of an assignment, used as
1234 -- an out parameters, or used as prefixes of access attributes). It
1235 -- sets May_Be_Modified in the associated entity if there is one,
1236 -- taking into account the rule that in the case of renamed objects,
1237 -- it is the flag in the renamed object that must be set.
1239 -- The parameter Sure is set True if the modification is sure to occur
1240 -- (e.g. target of assignment, or out parameter), and to False if the
1241 -- modification is only potential (e.g. address of entity taken).
1243 function Original_Corresponding_Operation
(S
: Entity_Id
) return Entity_Id
;
1244 -- [Ada 2012: AI05-0125-1]: If S is an inherited dispatching primitive S2,
1245 -- or overrides an inherited dispatching primitive S2, the original
1246 -- corresponding operation of S is the original corresponding operation of
1247 -- S2. Otherwise, it is S itself.
1249 function Object_Access_Level
(Obj
: Node_Id
) return Uint
;
1250 -- Return the accessibility level of the view of the object Obj.
1251 -- For convenience, qualified expressions applied to object names
1252 -- are also allowed as actuals for this function.
1254 function Primitive_Names_Match
(E1
, E2
: Entity_Id
) return Boolean;
1255 -- Returns True if the names of both entities correspond with matching
1256 -- primitives. This routine includes support for the case in which one
1257 -- or both entities correspond with entities built by Derive_Subprogram
1258 -- with a special name to avoid being overridden (i.e. return true in case
1259 -- of entities with names "nameP" and "name" or vice versa).
1261 function Private_Component
(Type_Id
: Entity_Id
) return Entity_Id
;
1262 -- Returns some private component (if any) of the given Type_Id.
1263 -- Used to enforce the rules on visibility of operations on composite
1264 -- types, that depend on the full view of the component type. For a
1265 -- record type there may be several such components, we just return
1268 procedure Process_End_Label
1272 -- N is a node whose End_Label is to be processed, generating all
1273 -- appropriate cross-reference entries, and performing style checks
1274 -- for any identifier references in the end label. Typ is either
1275 -- 'e' or 't indicating the type of the cross-reference entity
1276 -- (e for spec, t for body, see Lib.Xref spec for details). The
1277 -- parameter Ent gives the entity to which the End_Label refers,
1278 -- and to which cross-references are to be generated.
1280 function References_Generic_Formal_Type
(N
: Node_Id
) return Boolean;
1281 -- Returns True if the expression Expr contains any references to a
1282 -- generic type. This can only happen within a generic template.
1284 procedure Remove_Homonym
(E
: Entity_Id
);
1285 -- Removes E from the homonym chain
1287 function Rep_To_Pos_Flag
(E
: Entity_Id
; Loc
: Source_Ptr
) return Node_Id
;
1288 -- This is used to construct the second argument in a call to Rep_To_Pos
1289 -- which is Standard_True if range checks are enabled (E is an entity to
1290 -- which the Range_Checks_Suppressed test is applied), and Standard_False
1291 -- if range checks are suppressed. Loc is the location for the node that
1292 -- is returned (which is a New_Occurrence of the appropriate entity).
1294 -- Note: one might think that it would be fine to always use True and
1295 -- to ignore the suppress in this case, but it is generally better to
1296 -- believe a request to suppress exceptions if possible, and further
1297 -- more there is at least one case in the generated code (the code for
1298 -- array assignment in a loop) that depends on this suppression.
1300 procedure Require_Entity
(N
: Node_Id
);
1301 -- N is a node which should have an entity value if it is an entity name.
1302 -- If not, then check if there were previous errors. If so, just fill
1303 -- in with Any_Id and ignore. Otherwise signal a program error exception.
1304 -- This is used as a defense mechanism against ill-formed trees caused by
1305 -- previous errors (particularly in -gnatq mode).
1307 function Requires_Transient_Scope
(Id
: Entity_Id
) return Boolean;
1308 -- Id is a type entity. The result is True when temporaries of this type
1309 -- need to be wrapped in a transient scope to be reclaimed properly when a
1310 -- secondary stack is in use. Examples of types requiring such wrapping are
1311 -- controlled types and variable-sized types including unconstrained
1314 procedure Reset_Analyzed_Flags
(N
: Node_Id
);
1315 -- Reset the Analyzed flags in all nodes of the tree whose root is N
1317 function Returns_Unconstrained_Type
(Subp
: Entity_Id
) return Boolean;
1318 -- Return true if Subp is a function that returns an unconstrained type
1320 function Safe_To_Capture_Value
1323 Cond
: Boolean := False) return Boolean;
1324 -- The caller is interested in capturing a value (either the current value,
1325 -- or an indication that the value is non-null) for the given entity Ent.
1326 -- This value can only be captured if sequential execution semantics can be
1327 -- properly guaranteed so that a subsequent reference will indeed be sure
1328 -- that this current value indication is correct. The node N is the
1329 -- construct which resulted in the possible capture of the value (this
1330 -- is used to check if we are in a conditional).
1332 -- Cond is used to skip the test for being inside a conditional. It is used
1333 -- in the case of capturing values from if/while tests, which already do a
1334 -- proper job of handling scoping issues without this help.
1336 -- The only entities whose values can be captured are OUT and IN OUT formal
1337 -- parameters, and variables unless Cond is True, in which case we also
1338 -- allow IN formals, loop parameters and constants, where we cannot ever
1339 -- capture actual value information, but we can capture conditional tests.
1341 function Same_Name
(N1
, N2
: Node_Id
) return Boolean;
1342 -- Determine if two (possibly expanded) names are the same name. This is
1343 -- a purely syntactic test, and N1 and N2 need not be analyzed.
1345 function Same_Object
(Node1
, Node2
: Node_Id
) return Boolean;
1346 -- Determine if Node1 and Node2 are known to designate the same object.
1347 -- This is a semantic test and both nodes must be fully analyzed. A result
1348 -- of True is decisively correct. A result of False does not necessarily
1349 -- mean that different objects are designated, just that this could not
1350 -- be reliably determined at compile time.
1352 function Same_Type
(T1
, T2
: Entity_Id
) return Boolean;
1353 -- Determines if T1 and T2 represent exactly the same type. Two types
1354 -- are the same if they are identical, or if one is an unconstrained
1355 -- subtype of the other, or they are both common subtypes of the same
1356 -- type with identical constraints. The result returned is conservative.
1357 -- It is True if the types are known to be the same, but a result of
1358 -- False is indecisive (e.g. the compiler may not be able to tell that
1359 -- two constraints are identical).
1361 function Same_Value
(Node1
, Node2
: Node_Id
) return Boolean;
1362 -- Determines if Node1 and Node2 are known to be the same value, which is
1363 -- true if they are both compile time known values and have the same value,
1364 -- or if they are the same object (in the sense of function Same_Object).
1365 -- A result of False does not necessarily mean they have different values,
1366 -- just that it is not possible to determine they have the same value.
1368 function Scope_Within_Or_Same
(Scope1
, Scope2
: Entity_Id
) return Boolean;
1369 -- Determines if the entity Scope1 is the same as Scope2, or if it is
1370 -- inside it, where both entities represent scopes. Note that scopes
1371 -- are only partially ordered, so Scope_Within_Or_Same (A,B) and
1372 -- Scope_Within_Or_Same (B,A) can both be False for a given pair A,B.
1374 procedure Save_Actual
(N
: Node_Id
; Writable
: Boolean := False);
1375 -- Enter an actual in a call in a table global, for subsequent check of
1376 -- possible order dependence in the presence of IN OUT parameters for
1377 -- functions in Ada 2012 (or access parameters in older language versions).
1379 function Scope_Within
(Scope1
, Scope2
: Entity_Id
) return Boolean;
1380 -- Like Scope_Within_Or_Same, except that this function returns
1381 -- False in the case where Scope1 and Scope2 are the same scope.
1383 procedure Set_Convention
(E
: Entity_Id
; Val
: Convention_Id
);
1384 -- Same as Basic_Set_Convention, but with an extra check for access types.
1385 -- In particular, if E is an access-to-subprogram type, and Val is a
1386 -- foreign convention, then we set Can_Use_Internal_Rep to False on E.
1388 procedure Set_Current_Entity
(E
: Entity_Id
);
1389 pragma Inline
(Set_Current_Entity
);
1390 -- Establish the entity E as the currently visible definition of its
1391 -- associated name (i.e. the Node_Id associated with its name).
1393 procedure Set_Debug_Info_Needed
(T
: Entity_Id
);
1394 -- Sets the Debug_Info_Needed flag on entity T , and also on any entities
1395 -- that are needed by T (for an object, the type of the object is needed,
1396 -- and for a type, various subsidiary types are needed -- see body for
1397 -- details). Never has any effect on T if the Debug_Info_Off flag is set.
1398 -- This routine should always be used instead of Set_Needs_Debug_Info to
1399 -- ensure that subsidiary entities are properly handled.
1401 procedure Set_Entity_With_Style_Check
(N
: Node_Id
; Val
: Entity_Id
);
1402 -- This procedure has the same calling sequence as Set_Entity, but
1403 -- if Style_Check is set, then it calls a style checking routine which
1404 -- can check identifier spelling style.
1406 procedure Set_Name_Entity_Id
(Id
: Name_Id
; Val
: Entity_Id
);
1407 pragma Inline
(Set_Name_Entity_Id
);
1408 -- Sets the Entity_Id value associated with the given name, which is the
1409 -- Id of the innermost visible entity with the given name. See the body
1410 -- of package Sem_Ch8 for further details on the handling of visibility.
1412 procedure Set_Next_Actual
(Ass1_Id
: Node_Id
; Ass2_Id
: Node_Id
);
1413 -- The arguments may be parameter associations, whose descendants
1414 -- are the optional formal name and the actual parameter. Positional
1415 -- parameters are already members of a list, and do not need to be
1416 -- chained separately. See also First_Actual and Next_Actual.
1418 procedure Set_Optimize_Alignment_Flags
(E
: Entity_Id
);
1419 pragma Inline
(Set_Optimize_Alignment_Flags
);
1420 -- Sets Optimize_Alignment_Space/Time flags in E from current settings
1422 procedure Set_Public_Status
(Id
: Entity_Id
);
1423 -- If an entity (visible or otherwise) is defined in a library
1424 -- package, or a package that is itself public, then this subprogram
1425 -- labels the entity public as well.
1427 procedure Set_Referenced_Modified
(N
: Node_Id
; Out_Param
: Boolean);
1428 -- N is the node for either a left hand side (Out_Param set to False),
1429 -- or an Out or In_Out parameter (Out_Param set to True). If there is
1430 -- an assignable entity being referenced, then the appropriate flag
1431 -- (Referenced_As_LHS if Out_Param is False, Referenced_As_Out_Parameter
1432 -- if Out_Param is True) is set True, and the other flag set False.
1434 procedure Set_Scope_Is_Transient
(V
: Boolean := True);
1435 -- Set the flag Is_Transient of the current scope
1437 procedure Set_Size_Info
(T1
, T2
: Entity_Id
);
1438 pragma Inline
(Set_Size_Info
);
1439 -- Copies the Esize field and Has_Biased_Representation flag from sub(type)
1440 -- entity T2 to (sub)type entity T1. Also copies the Is_Unsigned_Type flag
1441 -- in the fixed-point and discrete cases, and also copies the alignment
1442 -- value from T2 to T1. It does NOT copy the RM_Size field, which must be
1443 -- separately set if this is required to be copied also.
1445 function Scope_Is_Transient
return Boolean;
1446 -- True if the current scope is transient
1448 function Static_Boolean
(N
: Node_Id
) return Uint
;
1449 -- This function analyzes the given expression node and then resolves it
1450 -- as Standard.Boolean. If the result is static, then Uint_1 or Uint_0 is
1451 -- returned corresponding to the value, otherwise an error message is
1452 -- output and No_Uint is returned.
1454 function Static_Integer
(N
: Node_Id
) return Uint
;
1455 -- This function analyzes the given expression node and then resolves it
1456 -- as any integer type. If the result is static, then the value of the
1457 -- universal expression is returned, otherwise an error message is output
1458 -- and a value of No_Uint is returned.
1460 function Statically_Different
(E1
, E2
: Node_Id
) return Boolean;
1461 -- Return True if it can be statically determined that the Expressions
1462 -- E1 and E2 refer to different objects
1464 function Subprogram_Access_Level
(Subp
: Entity_Id
) return Uint
;
1465 -- Return the accessibility level of the view denoted by Subp
1467 procedure Trace_Scope
(N
: Node_Id
; E
: Entity_Id
; Msg
: String);
1468 -- Print debugging information on entry to each unit being analyzed
1470 procedure Transfer_Entities
(From
: Entity_Id
; To
: Entity_Id
);
1471 -- Move a list of entities from one scope to another, and recompute
1472 -- Is_Public based upon the new scope.
1474 function Type_Access_Level
(Typ
: Entity_Id
) return Uint
;
1475 -- Return the accessibility level of Typ
1477 function Type_Without_Stream_Operation
1479 Op
: TSS_Name_Type
:= TSS_Null
) return Entity_Id
;
1480 -- AI05-0161: In Ada 2012, if the restriction No_Default_Stream_Attributes
1481 -- is active then we cannot generate stream subprograms for composite types
1482 -- with elementary subcomponents that lack user-defined stream subprograms.
1483 -- This predicate determines whether a type has such an elementary
1484 -- subcomponent. If Op is TSS_Null, a type that lacks either Read or Write
1485 -- prevents the construction of a composite stream operation. If Op is
1486 -- specified we check only for the given stream operation.
1488 function Unique_Defining_Entity
(N
: Node_Id
) return Entity_Id
;
1489 -- Return the entity which represents declaration N, so that different
1490 -- views of the same entity have the same unique defining entity:
1491 -- * package spec and body;
1492 -- * subprogram declaration, subprogram stub and subprogram body;
1493 -- * private view and full view of a type;
1494 -- * private view and full view of a deferred constant.
1495 -- In other cases, return the defining entity for N.
1497 function Unique_Entity
(E
: Entity_Id
) return Entity_Id
;
1498 -- Return the unique entity for entity E, which would be returned by
1499 -- Unique_Defining_Entity if applied to the enclosing declaration of E.
1501 function Unique_Name
(E
: Entity_Id
) return String;
1502 -- Return a unique name for entity E, which could be used to identify E
1503 -- across compilation units.
1505 function Unit_Is_Visible
(U
: Entity_Id
) return Boolean;
1506 -- Determine whether a compilation unit is visible in the current context,
1507 -- because there is a with_clause that makes the unit available. Used to
1508 -- provide better messages on common visiblity errors on operators.
1510 function Universal_Interpretation
(Opnd
: Node_Id
) return Entity_Id
;
1511 -- Yields Universal_Integer or Universal_Real if this is a candidate
1513 function Unqualify
(Expr
: Node_Id
) return Node_Id
;
1514 pragma Inline
(Unqualify
);
1515 -- Removes any qualifications from Expr. For example, for T1'(T2'(X)), this
1516 -- returns X. If Expr is not a qualified expression, returns Expr.
1518 function Visible_Ancestors
(Typ
: Entity_Id
) return Elist_Id
;
1519 -- [Ada 2012:AI-0125-1]: Collect all the visible parents and progenitors
1520 -- of a type extension or private extension declaration. If the full-view
1521 -- of private parents and progenitors is available then it is used to
1522 -- generate the list of visible ancestors; otherwise their partial
1523 -- view is added to the resulting list.
1525 function Within_Init_Proc
return Boolean;
1526 -- Determines if Current_Scope is within an init proc
1528 procedure Wrong_Type
(Expr
: Node_Id
; Expected_Type
: Entity_Id
);
1529 -- Output error message for incorrectly typed expression. Expr is the node
1530 -- for the incorrectly typed construct (Etype (Expr) is the type found),
1531 -- and Expected_Type is the entity for the expected type. Note that Expr
1532 -- does not have to be a subexpression, anything with an Etype field may