Add initial version of C++17 <memory_resource> header
[official-gcc.git] / gcc / ada / exp_code.adb
blob5c0b9de44c2ae9ea69114f4bb22f475579a162f0
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ C O D E --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1996-2018, Free Software Foundation, Inc. --
10 -- --
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. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Einfo; use Einfo;
28 with Errout; use Errout;
29 with Lib; use Lib;
30 with Namet; use Namet;
31 with Nlists; use Nlists;
32 with Nmake; use Nmake;
33 with Opt; use Opt;
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.
87 --------------------
88 -- Asm_Constraint --
89 --------------------
91 function Asm_Constraint (Operand_Var : Node_Id) return Node_Id is
92 begin
93 pragma Assert (Present (Operand_Var));
94 return Get_String_Node (First (Expressions (Operand_Var)));
95 end Asm_Constraint;
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
104 begin
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
115 begin
116 return Asm_Operand (Current_Input_Operand);
117 end Asm_Input_Value;
119 -----------------
120 -- Asm_Operand --
121 -----------------
123 function Asm_Operand (Operand_Var : Node_Id) return Node_Id is
124 begin
125 if No (Operand_Var) then
126 return Empty;
127 elsif Error_Posted (Operand_Var) then
128 return Error;
129 else
130 return Next (First (Expressions (Operand_Var)));
131 end if;
132 end Asm_Operand;
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
141 begin
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
152 begin
153 return Asm_Operand (Current_Output_Operand);
154 end Asm_Output_Variable;
156 ------------------
157 -- Asm_Template --
158 ------------------
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);
164 begin
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)
172 then
173 return Get_String_Node (Temp);
175 else
176 Flag_Non_Static_Expr ("asm template argument is not static!", Temp);
177 return Empty;
178 end if;
179 end Asm_Template;
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).
190 Clobber_Ptr : Pos;
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);
197 C : Character;
199 begin
200 if No (Clobber_Node) then
201 return Null_Address;
202 end if;
204 -- Skip spaces and commas before next register name
206 loop
207 -- Return null string if no more names
209 if Clobber_Ptr > Len then
210 return Null_Address;
211 end if;
213 C := Get_Character (Get_String_Char (Str, Clobber_Ptr));
214 exit when C /= ',' and then C /= ' ';
215 Clobber_Ptr := Clobber_Ptr + 1;
216 end loop;
218 -- Acquire next register name
220 Name_Len := 0;
221 loop
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 = ' ';
227 end loop;
229 Name_Buffer (Name_Len + 1) := ASCII.NUL;
230 return Name_Buffer'Address;
231 end Clobber_Get_Next;
233 -------------------
234 -- Clobber_Setup --
235 -------------------
237 procedure Clobber_Setup (N : Node_Id) is
238 Call : constant Node_Id := Expression (Expression (N));
239 Clob : constant Node_Id := Next_Actual (
240 Next_Actual (
241 Next_Actual (
242 First_Actual (Call))));
243 begin
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;
247 else
248 Clobber_Node := Get_String_Node (Clob);
249 Clobber_Ptr := 1;
250 end if;
251 end Clobber_Setup;
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
268 Err : Node_Id := N;
270 begin
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)))
277 then
278 return;
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
284 return;
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;
297 Next (Err);
298 end loop;
300 if No (Err) then
301 return;
302 end if;
303 end if;
304 end if;
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
313 begin
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 ::=
326 -- No_Input_Operands
327 -- | INPUT_OPERAND_ATTRIBUTE
328 -- | (INPUT_OPERAND_ATTRIBUTE @{,INPUT_OPERAND_ATTRIBUTE@})
330 -- INPUT_OPERAND_ATTRIBUTE ::=
331 -- SUBTYPE_MARK'Asm_Input (static_string_EXPRESSION, EXPRESSION)
333 declare
334 Arg_Output : constant Node_Id := Next_Actual (First_Actual (N));
335 Arg_Input : constant Node_Id := Next_Actual (Arg_Output);
336 begin
337 Check_IO_Operand (Arg_Output);
338 Check_IO_Operand (Arg_Input);
339 end;
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
345 null;
347 -- For the procedure case, we convert the call into a code statement
349 else
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.
357 Rewrite (N,
358 Make_Code_Statement (Loc,
359 Expression =>
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.
371 Set_Analyzed (N);
372 Check_Code_Statement (N);
373 end if;
374 end Expand_Asm_Call;
376 ---------------------
377 -- Get_String_Node --
378 ---------------------
380 function Get_String_Node (S : Node_Id) return Node_Id is
381 begin
382 if Nkind (S) = N_String_Literal then
383 return S;
384 else
385 pragma Assert (Ekind (Entity (S)) = E_Constant);
386 return Get_String_Node (Constant_Value (Entity (S)));
387 end if;
388 end Get_String_Node;
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 :=
397 Next_Actual (
398 Next_Actual (
399 Next_Actual (
400 Next_Actual (
401 First_Actual (Call)))));
402 begin
403 if not Is_OK_Static_Expression (Vol) then
404 Flag_Non_Static_Expr ("asm volatile argument is not static!", Vol);
405 return False;
406 else
407 return Is_True (Expr_Value (Vol));
408 end if;
409 end Is_Asm_Volatile;
411 --------------------
412 -- Next_Asm_Input --
413 --------------------
415 procedure Next_Asm_Input is
416 begin
417 Next_Asm_Operand (Current_Input_Operand);
418 end Next_Asm_Input;
420 ----------------------
421 -- Next_Asm_Operand --
422 ----------------------
424 procedure Next_Asm_Operand (Operand_Var : in out Node_Id) is
425 begin
426 pragma Assert (Present (Operand_Var));
428 if Nkind (Parent (Operand_Var)) = N_Aggregate then
429 Operand_Var := Next (Operand_Var);
430 else
431 Operand_Var := Empty;
432 end if;
433 end Next_Asm_Operand;
435 ---------------------
436 -- Next_Asm_Output --
437 ---------------------
439 procedure Next_Asm_Output is
440 begin
441 Next_Asm_Operand (Current_Output_Operand);
442 end Next_Asm_Output;
444 ----------------------
445 -- Setup_Asm_Inputs --
446 ----------------------
448 procedure Setup_Asm_Inputs (N : Node_Id) is
449 Call : constant Node_Id := Expression (Expression (N));
450 begin
451 Setup_Asm_IO_Args
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
461 begin
462 -- Case of single argument
464 if Nkind (Arg) = N_Attribute_Reference then
465 Operand_Var := Arg;
467 -- Case of list of arguments
469 elsif Nkind (Arg) = N_Aggregate then
470 if Expressions (Arg) = No_List then
471 Operand_Var := Empty;
472 else
473 Operand_Var := First (Expressions (Arg));
474 end if;
476 -- Otherwise must be default (no operands) case
478 else
479 Operand_Var := Empty;
480 end if;
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));
489 begin
490 Setup_Asm_IO_Args
491 (Next_Actual (First_Actual (Call)),
492 Current_Output_Operand);
493 end Setup_Asm_Outputs;
495 end Exp_Code;