1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1996-2018, 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 Einfo
; use Einfo
;
28 with Errout
; use Errout
;
30 with Namet
; use Namet
;
31 with Nlists
; use Nlists
;
32 with Nmake
; use Nmake
;
34 with Rtsfind
; use Rtsfind
;
35 with Sem_Aux
; use Sem_Aux
;
36 with Sem_Eval
; use Sem_Eval
;
37 with Sem_Util
; use Sem_Util
;
38 with Sem_Warn
; use Sem_Warn
;
39 with Sinfo
; use Sinfo
;
40 with Stringt
; use Stringt
;
41 with Tbuild
; use Tbuild
;
43 package body Exp_Code
is
45 -----------------------
46 -- Local_Subprograms --
47 -----------------------
49 function Asm_Constraint
(Operand_Var
: Node_Id
) return Node_Id
;
50 -- Common processing for Asm_Input_Constraint and Asm_Output_Constraint.
51 -- Obtains the constraint argument from the global operand variable
52 -- Operand_Var, which must be non-Empty.
54 function Asm_Operand
(Operand_Var
: Node_Id
) return Node_Id
;
55 -- Common processing for Asm_Input_Value and Asm_Output_Variable. Obtains
56 -- the value/variable argument from Operand_Var, the global operand
57 -- variable. Returns Empty if no operand available.
59 function Get_String_Node
(S
: Node_Id
) return Node_Id
;
60 -- Given S, a static expression node of type String, returns the
61 -- string literal node. This is needed to deal with the use of constants
62 -- for these expressions, which is perfectly permissible.
64 procedure Next_Asm_Operand
(Operand_Var
: in out Node_Id
);
65 -- Common processing for Next_Asm_Input and Next_Asm_Output, updates
66 -- the value of the global operand variable Operand_Var appropriately.
68 procedure Setup_Asm_IO_Args
(Arg
: Node_Id
; Operand_Var
: out Node_Id
);
69 -- Common processing for Setup_Asm_Inputs and Setup_Asm_Outputs. Arg
70 -- is the actual parameter from the call, and Operand_Var is the global
71 -- operand variable to be initialized to the first operand.
73 ----------------------
74 -- Global Variables --
75 ----------------------
77 Current_Input_Operand
: Node_Id
:= Empty
;
78 -- Points to current Asm_Input_Operand attribute reference. Initialized
79 -- by Setup_Asm_Inputs, updated by Next_Asm_Input, and referenced by
80 -- Asm_Input_Constraint and Asm_Input_Value.
82 Current_Output_Operand
: Node_Id
:= Empty
;
83 -- Points to current Asm_Output_Operand attribute reference. Initialized
84 -- by Setup_Asm_Outputs, updated by Next_Asm_Output, and referenced by
85 -- Asm_Output_Constraint and Asm_Output_Variable.
91 function Asm_Constraint
(Operand_Var
: Node_Id
) return Node_Id
is
93 pragma Assert
(Present
(Operand_Var
));
94 return Get_String_Node
(First
(Expressions
(Operand_Var
)));
97 --------------------------
98 -- Asm_Input_Constraint --
99 --------------------------
101 -- Note: error checking on Asm_Input attribute done in Sem_Attr
103 function Asm_Input_Constraint
return Node_Id
is
105 return Get_String_Node
(Asm_Constraint
(Current_Input_Operand
));
106 end Asm_Input_Constraint
;
108 ---------------------
109 -- Asm_Input_Value --
110 ---------------------
112 -- Note: error checking on Asm_Input attribute done in Sem_Attr
114 function Asm_Input_Value
return Node_Id
is
116 return Asm_Operand
(Current_Input_Operand
);
123 function Asm_Operand
(Operand_Var
: Node_Id
) return Node_Id
is
125 if No
(Operand_Var
) then
127 elsif Error_Posted
(Operand_Var
) then
130 return Next
(First
(Expressions
(Operand_Var
)));
134 ---------------------------
135 -- Asm_Output_Constraint --
136 ---------------------------
138 -- Note: error checking on Asm_Output attribute done in Sem_Attr
140 function Asm_Output_Constraint
return Node_Id
is
142 return Asm_Constraint
(Current_Output_Operand
);
143 end Asm_Output_Constraint
;
145 -------------------------
146 -- Asm_Output_Variable --
147 -------------------------
149 -- Note: error checking on Asm_Output attribute done in Sem_Attr
151 function Asm_Output_Variable
return Node_Id
is
153 return Asm_Operand
(Current_Output_Operand
);
154 end Asm_Output_Variable
;
160 function Asm_Template
(N
: Node_Id
) return Node_Id
is
161 Call
: constant Node_Id
:= Expression
(Expression
(N
));
162 Temp
: constant Node_Id
:= First_Actual
(Call
);
165 -- Require static expression for template. We also allow a string
166 -- literal (this is useful for Ada 83 mode where string expressions
167 -- are never static).
169 if Is_OK_Static_Expression
(Temp
)
170 or else (Ada_Version
= Ada_83
171 and then Nkind
(Temp
) = N_String_Literal
)
173 return Get_String_Node
(Temp
);
176 Flag_Non_Static_Expr
("asm template argument is not static!", Temp
);
181 ----------------------
182 -- Clobber_Get_Next --
183 ----------------------
185 Clobber_Node
: Node_Id
;
186 -- String literal node for clobber string. Initialized by Clobber_Setup,
187 -- and not modified by Clobber_Get_Next. Empty if clobber string was in
188 -- error (resulting in no clobber arguments being returned).
191 -- Pointer to current character of string. Initialized to 1 by the call
192 -- to Clobber_Setup, and then updated by Clobber_Get_Next.
194 function Clobber_Get_Next
return Address
is
195 Str
: constant String_Id
:= Strval
(Clobber_Node
);
196 Len
: constant Nat
:= String_Length
(Str
);
200 if No
(Clobber_Node
) then
204 -- Skip spaces and commas before next register name
207 -- Return null string if no more names
209 if Clobber_Ptr
> Len
then
213 C
:= Get_Character
(Get_String_Char
(Str
, Clobber_Ptr
));
214 exit when C
/= ',' and then C
/= ' ';
215 Clobber_Ptr
:= Clobber_Ptr
+ 1;
218 -- Acquire next register name
222 Add_Char_To_Name_Buffer
(C
);
223 Clobber_Ptr
:= Clobber_Ptr
+ 1;
224 exit when Clobber_Ptr
> Len
;
225 C
:= Get_Character
(Get_String_Char
(Str
, Clobber_Ptr
));
226 exit when C
= ',' or else C
= ' ';
229 Name_Buffer
(Name_Len
+ 1) := ASCII
.NUL
;
230 return Name_Buffer
'Address;
231 end Clobber_Get_Next
;
237 procedure Clobber_Setup
(N
: Node_Id
) is
238 Call
: constant Node_Id
:= Expression
(Expression
(N
));
239 Clob
: constant Node_Id
:= Next_Actual
(
242 First_Actual
(Call
))));
244 if not Is_OK_Static_Expression
(Clob
) then
245 Flag_Non_Static_Expr
("asm clobber argument is not static!", Clob
);
246 Clobber_Node
:= Empty
;
248 Clobber_Node
:= Get_String_Node
(Clob
);
253 ---------------------
254 -- Expand_Asm_Call --
255 ---------------------
257 procedure Expand_Asm_Call
(N
: Node_Id
) is
258 Loc
: constant Source_Ptr
:= Sloc
(N
);
260 procedure Check_IO_Operand
(N
: Node_Id
);
261 -- Check for incorrect input or output operand
263 ----------------------
264 -- Check_IO_Operand --
265 ----------------------
267 procedure Check_IO_Operand
(N
: Node_Id
) is
271 -- The only identifier allowed is No_xxput_Operands. Since we
272 -- know the type is right, it is sufficient to see if the
273 -- referenced entity is in a runtime routine.
275 if Is_Entity_Name
(N
)
276 and then Is_Predefined_Unit
(Get_Source_Unit
(Entity
(N
)))
280 -- An attribute reference is fine, again the analysis reasonably
281 -- guarantees that the attribute must be subtype'Asm_??put.
283 elsif Nkind
(N
) = N_Attribute_Reference
then
286 -- The only other allowed form is an array aggregate in which
287 -- all the entries are positional and are attribute references.
289 elsif Nkind
(N
) = N_Aggregate
then
290 if Present
(Component_Associations
(N
)) then
291 Err
:= First
(Component_Associations
(N
));
293 elsif Present
(Expressions
(N
)) then
294 Err
:= First
(Expressions
(N
));
295 while Present
(Err
) loop
296 exit when Nkind
(Err
) /= N_Attribute_Reference
;
306 -- If we fall through, Err is pointing to the bad node
308 Error_Msg_N
("Asm operand has wrong form", Err
);
309 end Check_IO_Operand
;
311 -- Start of processing for Expand_Asm_Call
314 -- Check that the input and output operands have the right
315 -- form, as required by the documentation of the Asm feature:
317 -- OUTPUT_OPERAND_LIST ::=
318 -- No_Output_Operands
319 -- | OUTPUT_OPERAND_ATTRIBUTE
320 -- | (OUTPUT_OPERAND_ATTRIBUTE @{,OUTPUT_OPERAND_ATTRIBUTE@})
322 -- OUTPUT_OPERAND_ATTRIBUTE ::=
323 -- SUBTYPE_MARK'Asm_Output (static_string_EXPRESSION, NAME)
325 -- INPUT_OPERAND_LIST ::=
327 -- | INPUT_OPERAND_ATTRIBUTE
328 -- | (INPUT_OPERAND_ATTRIBUTE @{,INPUT_OPERAND_ATTRIBUTE@})
330 -- INPUT_OPERAND_ATTRIBUTE ::=
331 -- SUBTYPE_MARK'Asm_Input (static_string_EXPRESSION, EXPRESSION)
334 Arg_Output
: constant Node_Id
:= Next_Actual
(First_Actual
(N
));
335 Arg_Input
: constant Node_Id
:= Next_Actual
(Arg_Output
);
337 Check_IO_Operand
(Arg_Output
);
338 Check_IO_Operand
(Arg_Input
);
341 -- If we have the function call case, we are inside a code statement,
342 -- and the tree is already in the necessary form for gigi.
344 if Nkind
(N
) = N_Function_Call
then
347 -- For the procedure case, we convert the call into a code statement
350 pragma Assert
(Nkind
(N
) = N_Procedure_Call_Statement
);
352 -- Note: strictly we should change the procedure call to a function
353 -- call in the qualified expression, but since we are not going to
354 -- reanalyze (see below), and the interface subprograms in this
355 -- package don't care, we can leave it as a procedure call.
358 Make_Code_Statement
(Loc
,
360 Make_Qualified_Expression
(Loc
,
361 Subtype_Mark
=> New_Occurrence_Of
(RTE
(RE_Asm_Insn
), Loc
),
362 Expression
=> Relocate_Node
(N
))));
364 -- There is no need to reanalyze this node, it is completely analyzed
365 -- already, at least sufficiently for the purposes of the abstract
366 -- procedural interface defined in this package. Furthermore if we
367 -- let it go through the normal analysis, that would include some
368 -- inappropriate checks that apply only to explicit code statements
369 -- in the source, and not to calls to intrinsics.
372 Check_Code_Statement
(N
);
376 ---------------------
377 -- Get_String_Node --
378 ---------------------
380 function Get_String_Node
(S
: Node_Id
) return Node_Id
is
382 if Nkind
(S
) = N_String_Literal
then
385 pragma Assert
(Ekind
(Entity
(S
)) = E_Constant
);
386 return Get_String_Node
(Constant_Value
(Entity
(S
)));
390 ---------------------
391 -- Is_Asm_Volatile --
392 ---------------------
394 function Is_Asm_Volatile
(N
: Node_Id
) return Boolean is
395 Call
: constant Node_Id
:= Expression
(Expression
(N
));
396 Vol
: constant Node_Id
:=
401 First_Actual
(Call
)))));
403 if not Is_OK_Static_Expression
(Vol
) then
404 Flag_Non_Static_Expr
("asm volatile argument is not static!", Vol
);
407 return Is_True
(Expr_Value
(Vol
));
415 procedure Next_Asm_Input
is
417 Next_Asm_Operand
(Current_Input_Operand
);
420 ----------------------
421 -- Next_Asm_Operand --
422 ----------------------
424 procedure Next_Asm_Operand
(Operand_Var
: in out Node_Id
) is
426 pragma Assert
(Present
(Operand_Var
));
428 if Nkind
(Parent
(Operand_Var
)) = N_Aggregate
then
429 Operand_Var
:= Next
(Operand_Var
);
431 Operand_Var
:= Empty
;
433 end Next_Asm_Operand
;
435 ---------------------
436 -- Next_Asm_Output --
437 ---------------------
439 procedure Next_Asm_Output
is
441 Next_Asm_Operand
(Current_Output_Operand
);
444 ----------------------
445 -- Setup_Asm_Inputs --
446 ----------------------
448 procedure Setup_Asm_Inputs
(N
: Node_Id
) is
449 Call
: constant Node_Id
:= Expression
(Expression
(N
));
452 (Next_Actual
(Next_Actual
(First_Actual
(Call
))),
453 Current_Input_Operand
);
454 end Setup_Asm_Inputs
;
456 -----------------------
457 -- Setup_Asm_IO_Args --
458 -----------------------
460 procedure Setup_Asm_IO_Args
(Arg
: Node_Id
; Operand_Var
: out Node_Id
) is
462 -- Case of single argument
464 if Nkind
(Arg
) = N_Attribute_Reference
then
467 -- Case of list of arguments
469 elsif Nkind
(Arg
) = N_Aggregate
then
470 if Expressions
(Arg
) = No_List
then
471 Operand_Var
:= Empty
;
473 Operand_Var
:= First
(Expressions
(Arg
));
476 -- Otherwise must be default (no operands) case
479 Operand_Var
:= Empty
;
481 end Setup_Asm_IO_Args
;
483 -----------------------
484 -- Setup_Asm_Outputs --
485 -----------------------
487 procedure Setup_Asm_Outputs
(N
: Node_Id
) is
488 Call
: constant Node_Id
:= Expression
(Expression
(N
));
491 (Next_Actual
(First_Actual
(Call
)),
492 Current_Output_Operand
);
493 end Setup_Asm_Outputs
;