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* tree.c (protected_set_expr_location): New.
[official-gcc.git] / gcc / c-typeck.c
blob2246526b8bf7fca957cb3444f65ef73a1c4d2bd4
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22
23 /* This file is part of the C front end.
24 It contains routines to build C expressions given their operands,
25 including computing the types of the result, C-specific error checks,
26 and some optimization. */
27
28 #include "config.h"
29 #include "system.h"
30 #include "coretypes.h"
31 #include "tm.h"
32 #include "rtl.h"
33 #include "tree.h"
34 #include "langhooks.h"
35 #include "c-tree.h"
36 #include "tm_p.h"
37 #include "flags.h"
38 #include "output.h"
39 #include "expr.h"
40 #include "toplev.h"
41 #include "intl.h"
42 #include "ggc.h"
43 #include "target.h"
44 #include "tree-iterator.h"
45 #include "gimple.h"
46 #include "tree-flow.h"
47
48 /* Possible cases of implicit bad conversions. Used to select
49 diagnostic messages in convert_for_assignment. */
50 enum impl_conv {
51 ic_argpass,
52 ic_argpass_nonproto,
53 ic_assign,
54 ic_init,
55 ic_return
56 };
57
58 /* The level of nesting inside "__alignof__". */
59 int in_alignof;
60
61 /* The level of nesting inside "sizeof". */
62 int in_sizeof;
63
64 /* The level of nesting inside "typeof". */
65 int in_typeof;
66
67 struct c_label_context_se *label_context_stack_se;
68 struct c_label_context_vm *label_context_stack_vm;
69
70 /* Nonzero if we've already printed a "missing braces around initializer"
71 message within this initializer. */
72 static int missing_braces_mentioned;
73
74 static int require_constant_value;
75 static int require_constant_elements;
76
77 static bool null_pointer_constant_p (const_tree);
78 static tree qualify_type (tree, tree);
79 static int tagged_types_tu_compatible_p (const_tree, const_tree);
80 static int comp_target_types (tree, tree);
81 static int function_types_compatible_p (const_tree, const_tree);
82 static int type_lists_compatible_p (const_tree, const_tree);
83 static tree decl_constant_value_for_broken_optimization (tree);
84 static tree lookup_field (tree, tree);
85 static int convert_arguments (int, tree *, tree, tree, tree, tree);
86 static tree pointer_diff (tree, tree);
87 static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree,
88 int);
89 static tree valid_compound_expr_initializer (tree, tree);
90 static void push_string (const char *);
91 static void push_member_name (tree);
92 static int spelling_length (void);
93 static char *print_spelling (char *);
94 static void warning_init (int, const char *);
95 static tree digest_init (tree, tree, bool, int);
96 static void output_init_element (tree, bool, tree, tree, int);
97 static void output_pending_init_elements (int);
98 static int set_designator (int);
99 static void push_range_stack (tree);
100 static void add_pending_init (tree, tree);
101 static void set_nonincremental_init (void);
102 static void set_nonincremental_init_from_string (tree);
103 static tree find_init_member (tree);
104 static void readonly_error (tree, enum lvalue_use);
105 static int lvalue_or_else (const_tree, enum lvalue_use);
106 static int lvalue_p (const_tree);
107 static void record_maybe_used_decl (tree);
108 static int comptypes_internal (const_tree, const_tree);
109 \f
110 /* Return true if EXP is a null pointer constant, false otherwise. */
111
112 static bool
113 null_pointer_constant_p (const_tree expr)
114 {
115 /* This should really operate on c_expr structures, but they aren't
116 yet available everywhere required. */
117 tree type = TREE_TYPE (expr);
118 return (TREE_CODE (expr) == INTEGER_CST
119 && !TREE_OVERFLOW (expr)
120 && integer_zerop (expr)
121 && (INTEGRAL_TYPE_P (type)
122 || (TREE_CODE (type) == POINTER_TYPE
123 && VOID_TYPE_P (TREE_TYPE (type))
124 && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED)));
125 }
126 \f/* This is a cache to hold if two types are compatible or not. */
127
128 struct tagged_tu_seen_cache {
129 const struct tagged_tu_seen_cache * next;
130 const_tree t1;
131 const_tree t2;
132 /* The return value of tagged_types_tu_compatible_p if we had seen
133 these two types already. */
134 int val;
135 };
136
137 static const struct tagged_tu_seen_cache * tagged_tu_seen_base;
138 static void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *);
139
140 /* Do `exp = require_complete_type (exp);' to make sure exp
141 does not have an incomplete type. (That includes void types.) */
142
143 tree
144 require_complete_type (tree value)
145 {
146 tree type = TREE_TYPE (value);
147
148 if (value == error_mark_node || type == error_mark_node)
149 return error_mark_node;
150
151 /* First, detect a valid value with a complete type. */
152 if (COMPLETE_TYPE_P (type))
153 return value;
154
155 c_incomplete_type_error (value, type);
156 return error_mark_node;
157 }
158
159 /* Print an error message for invalid use of an incomplete type.
160 VALUE is the expression that was used (or 0 if that isn't known)
161 and TYPE is the type that was invalid. */
162
163 void
164 c_incomplete_type_error (const_tree value, const_tree type)
165 {
166 const char *type_code_string;
167
168 /* Avoid duplicate error message. */
169 if (TREE_CODE (type) == ERROR_MARK)
170 return;
171
172 if (value != 0 && (TREE_CODE (value) == VAR_DECL
173 || TREE_CODE (value) == PARM_DECL))
174 error ("%qD has an incomplete type", value);
175 else
176 {
177 retry:
178 /* We must print an error message. Be clever about what it says. */
179
180 switch (TREE_CODE (type))
181 {
182 case RECORD_TYPE:
183 type_code_string = "struct";
184 break;
185
186 case UNION_TYPE:
187 type_code_string = "union";
188 break;
189
190 case ENUMERAL_TYPE:
191 type_code_string = "enum";
192 break;
193
194 case VOID_TYPE:
195 error ("invalid use of void expression");
196 return;
197
198 case ARRAY_TYPE:
199 if (TYPE_DOMAIN (type))
200 {
201 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
202 {
203 error ("invalid use of flexible array member");
204 return;
205 }
206 type = TREE_TYPE (type);
207 goto retry;
208 }
209 error ("invalid use of array with unspecified bounds");
210 return;
211
212 default:
213 gcc_unreachable ();
214 }
215
216 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
217 error ("invalid use of undefined type %<%s %E%>",
218 type_code_string, TYPE_NAME (type));
219 else
220 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
221 error ("invalid use of incomplete typedef %qD", TYPE_NAME (type));
222 }
223 }
224
225 /* Given a type, apply default promotions wrt unnamed function
226 arguments and return the new type. */
227
228 tree
229 c_type_promotes_to (tree type)
230 {
231 if (TYPE_MAIN_VARIANT (type) == float_type_node)
232 return double_type_node;
233
234 if (c_promoting_integer_type_p (type))
235 {
236 /* Preserve unsignedness if not really getting any wider. */
237 if (TYPE_UNSIGNED (type)
238 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
239 return unsigned_type_node;
240 return integer_type_node;
241 }
242
243 return type;
244 }
245
246 /* Return a variant of TYPE which has all the type qualifiers of LIKE
247 as well as those of TYPE. */
248
249 static tree
250 qualify_type (tree type, tree like)
251 {
252 return c_build_qualified_type (type,
253 TYPE_QUALS (type) | TYPE_QUALS (like));
254 }
255
256 /* Return true iff the given tree T is a variable length array. */
257
258 bool
259 c_vla_type_p (const_tree t)
260 {
261 if (TREE_CODE (t) == ARRAY_TYPE
262 && C_TYPE_VARIABLE_SIZE (t))
263 return true;
264 return false;
265 }
266 \f
267 /* Return the composite type of two compatible types.
268
269 We assume that comptypes has already been done and returned
270 nonzero; if that isn't so, this may crash. In particular, we
271 assume that qualifiers match. */
272
273 tree
274 composite_type (tree t1, tree t2)
275 {
276 enum tree_code code1;
277 enum tree_code code2;
278 tree attributes;
279
280 /* Save time if the two types are the same. */
281
282 if (t1 == t2) return t1;
283
284 /* If one type is nonsense, use the other. */
285 if (t1 == error_mark_node)
286 return t2;
287 if (t2 == error_mark_node)
288 return t1;
289
290 code1 = TREE_CODE (t1);
291 code2 = TREE_CODE (t2);
292
293 /* Merge the attributes. */
294 attributes = targetm.merge_type_attributes (t1, t2);
295
296 /* If one is an enumerated type and the other is the compatible
297 integer type, the composite type might be either of the two
298 (DR#013 question 3). For consistency, use the enumerated type as
299 the composite type. */
300
301 if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE)
302 return t1;
303 if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE)
304 return t2;
305
306 gcc_assert (code1 == code2);
307
308 switch (code1)
309 {
310 case POINTER_TYPE:
311 /* For two pointers, do this recursively on the target type. */
312 {
313 tree pointed_to_1 = TREE_TYPE (t1);
314 tree pointed_to_2 = TREE_TYPE (t2);
315 tree target = composite_type (pointed_to_1, pointed_to_2);
316 t1 = build_pointer_type (target);
317 t1 = build_type_attribute_variant (t1, attributes);
318 return qualify_type (t1, t2);
319 }
320
321 case ARRAY_TYPE:
322 {
323 tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
324 int quals;
325 tree unqual_elt;
326 tree d1 = TYPE_DOMAIN (t1);
327 tree d2 = TYPE_DOMAIN (t2);
328 bool d1_variable, d2_variable;
329 bool d1_zero, d2_zero;
330
331 /* We should not have any type quals on arrays at all. */
332 gcc_assert (!TYPE_QUALS (t1) && !TYPE_QUALS (t2));
333
334 d1_zero = d1 == 0 || !TYPE_MAX_VALUE (d1);
335 d2_zero = d2 == 0 || !TYPE_MAX_VALUE (d2);
336
337 d1_variable = (!d1_zero
338 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
339 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
340 d2_variable = (!d2_zero
341 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
342 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
343 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
344 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
345
346 /* Save space: see if the result is identical to one of the args. */
347 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)
348 && (d2_variable || d2_zero || !d1_variable))
349 return build_type_attribute_variant (t1, attributes);
350 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)
351 && (d1_variable || d1_zero || !d2_variable))
352 return build_type_attribute_variant (t2, attributes);
353
354 if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
355 return build_type_attribute_variant (t1, attributes);
356 if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
357 return build_type_attribute_variant (t2, attributes);
358
359 /* Merge the element types, and have a size if either arg has
360 one. We may have qualifiers on the element types. To set
361 up TYPE_MAIN_VARIANT correctly, we need to form the
362 composite of the unqualified types and add the qualifiers
363 back at the end. */
364 quals = TYPE_QUALS (strip_array_types (elt));
365 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
366 t1 = build_array_type (unqual_elt,
367 TYPE_DOMAIN ((TYPE_DOMAIN (t1)
368 && (d2_variable
369 || d2_zero
370 || !d1_variable))
371 ? t1
372 : t2));
373 t1 = c_build_qualified_type (t1, quals);
374 return build_type_attribute_variant (t1, attributes);
375 }
376
377 case ENUMERAL_TYPE:
378 case RECORD_TYPE:
379 case UNION_TYPE:
380 if (attributes != NULL)
381 {
382 /* Try harder not to create a new aggregate type. */
383 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
384 return t1;
385 if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
386 return t2;
387 }
388 return build_type_attribute_variant (t1, attributes);
389
390 case FUNCTION_TYPE:
391 /* Function types: prefer the one that specified arg types.
392 If both do, merge the arg types. Also merge the return types. */
393 {
394 tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
395 tree p1 = TYPE_ARG_TYPES (t1);
396 tree p2 = TYPE_ARG_TYPES (t2);
397 int len;
398 tree newargs, n;
399 int i;
400
401 /* Save space: see if the result is identical to one of the args. */
402 if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2))
403 return build_type_attribute_variant (t1, attributes);
404 if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1))
405 return build_type_attribute_variant (t2, attributes);
406
407 /* Simple way if one arg fails to specify argument types. */
408 if (TYPE_ARG_TYPES (t1) == 0)
409 {
410 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
411 t1 = build_type_attribute_variant (t1, attributes);
412 return qualify_type (t1, t2);
413 }
414 if (TYPE_ARG_TYPES (t2) == 0)
415 {
416 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
417 t1 = build_type_attribute_variant (t1, attributes);
418 return qualify_type (t1, t2);
419 }
420
421 /* If both args specify argument types, we must merge the two
422 lists, argument by argument. */
423 /* Tell global_bindings_p to return false so that variable_size
424 doesn't die on VLAs in parameter types. */
425 c_override_global_bindings_to_false = true;
426
427 len = list_length (p1);
428 newargs = 0;
429
430 for (i = 0; i < len; i++)
431 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
432
433 n = newargs;
434
435 for (; p1;
436 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
437 {
438 /* A null type means arg type is not specified.
439 Take whatever the other function type has. */
440 if (TREE_VALUE (p1) == 0)
441 {
442 TREE_VALUE (n) = TREE_VALUE (p2);
443 goto parm_done;
444 }
445 if (TREE_VALUE (p2) == 0)
446 {
447 TREE_VALUE (n) = TREE_VALUE (p1);
448 goto parm_done;
449 }
450
451 /* Given wait (union {union wait *u; int *i} *)
452 and wait (union wait *),
453 prefer union wait * as type of parm. */
454 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
455 && TREE_VALUE (p1) != TREE_VALUE (p2))
456 {
457 tree memb;
458 tree mv2 = TREE_VALUE (p2);
459 if (mv2 && mv2 != error_mark_node
460 && TREE_CODE (mv2) != ARRAY_TYPE)
461 mv2 = TYPE_MAIN_VARIANT (mv2);
462 for (memb = TYPE_FIELDS (TREE_VALUE (p1));
463 memb; memb = TREE_CHAIN (memb))
464 {
465 tree mv3 = TREE_TYPE (memb);
466 if (mv3 && mv3 != error_mark_node
467 && TREE_CODE (mv3) != ARRAY_TYPE)
468 mv3 = TYPE_MAIN_VARIANT (mv3);
469 if (comptypes (mv3, mv2))
470 {
471 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
472 TREE_VALUE (p2));
473 pedwarn (input_location, OPT_pedantic,
474 "function types not truly compatible in ISO C");
475 goto parm_done;
476 }
477 }
478 }
479 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
480 && TREE_VALUE (p2) != TREE_VALUE (p1))
481 {
482 tree memb;
483 tree mv1 = TREE_VALUE (p1);
484 if (mv1 && mv1 != error_mark_node
485 && TREE_CODE (mv1) != ARRAY_TYPE)
486 mv1 = TYPE_MAIN_VARIANT (mv1);
487 for (memb = TYPE_FIELDS (TREE_VALUE (p2));
488 memb; memb = TREE_CHAIN (memb))
489 {
490 tree mv3 = TREE_TYPE (memb);
491 if (mv3 && mv3 != error_mark_node
492 && TREE_CODE (mv3) != ARRAY_TYPE)
493 mv3 = TYPE_MAIN_VARIANT (mv3);
494 if (comptypes (mv3, mv1))
495 {
496 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
497 TREE_VALUE (p1));
498 pedwarn (input_location, OPT_pedantic,
499 "function types not truly compatible in ISO C");
500 goto parm_done;
501 }
502 }
503 }
504 TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2));
505 parm_done: ;
506 }
507
508 c_override_global_bindings_to_false = false;
509 t1 = build_function_type (valtype, newargs);
510 t1 = qualify_type (t1, t2);
511 /* ... falls through ... */
512 }
513
514 default:
515 return build_type_attribute_variant (t1, attributes);
516 }
517
518 }
519
520 /* Return the type of a conditional expression between pointers to
521 possibly differently qualified versions of compatible types.
522
523 We assume that comp_target_types has already been done and returned
524 nonzero; if that isn't so, this may crash. */
525
526 static tree
527 common_pointer_type (tree t1, tree t2)
528 {
529 tree attributes;
530 tree pointed_to_1, mv1;
531 tree pointed_to_2, mv2;
532 tree target;
533 unsigned target_quals;
534
535 /* Save time if the two types are the same. */
536
537 if (t1 == t2) return t1;
538
539 /* If one type is nonsense, use the other. */
540 if (t1 == error_mark_node)
541 return t2;
542 if (t2 == error_mark_node)
543 return t1;
544
545 gcc_assert (TREE_CODE (t1) == POINTER_TYPE
546 && TREE_CODE (t2) == POINTER_TYPE);
547
548 /* Merge the attributes. */
549 attributes = targetm.merge_type_attributes (t1, t2);
550
551 /* Find the composite type of the target types, and combine the
552 qualifiers of the two types' targets. Do not lose qualifiers on
553 array element types by taking the TYPE_MAIN_VARIANT. */
554 mv1 = pointed_to_1 = TREE_TYPE (t1);
555 mv2 = pointed_to_2 = TREE_TYPE (t2);
556 if (TREE_CODE (mv1) != ARRAY_TYPE)
557 mv1 = TYPE_MAIN_VARIANT (pointed_to_1);
558 if (TREE_CODE (mv2) != ARRAY_TYPE)
559 mv2 = TYPE_MAIN_VARIANT (pointed_to_2);
560 target = composite_type (mv1, mv2);
561
562 /* For function types do not merge const qualifiers, but drop them
563 if used inconsistently. The middle-end uses these to mark const
564 and noreturn functions. */
565 if (TREE_CODE (pointed_to_1) == FUNCTION_TYPE)
566 target_quals = TYPE_QUALS (pointed_to_1) & TYPE_QUALS (pointed_to_2);
567 else
568 target_quals = TYPE_QUALS (pointed_to_1) | TYPE_QUALS (pointed_to_2);
569 t1 = build_pointer_type (c_build_qualified_type (target, target_quals));
570 return build_type_attribute_variant (t1, attributes);
571 }
572
573 /* Return the common type for two arithmetic types under the usual
574 arithmetic conversions. The default conversions have already been
575 applied, and enumerated types converted to their compatible integer
576 types. The resulting type is unqualified and has no attributes.
577
578 This is the type for the result of most arithmetic operations
579 if the operands have the given two types. */
580
581 static tree
582 c_common_type (tree t1, tree t2)
583 {
584 enum tree_code code1;
585 enum tree_code code2;
586
587 /* If one type is nonsense, use the other. */
588 if (t1 == error_mark_node)
589 return t2;
590 if (t2 == error_mark_node)
591 return t1;
592
593 if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED)
594 t1 = TYPE_MAIN_VARIANT (t1);
595
596 if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED)
597 t2 = TYPE_MAIN_VARIANT (t2);
598
599 if (TYPE_ATTRIBUTES (t1) != NULL_TREE)
600 t1 = build_type_attribute_variant (t1, NULL_TREE);
601
602 if (TYPE_ATTRIBUTES (t2) != NULL_TREE)
603 t2 = build_type_attribute_variant (t2, NULL_TREE);
604
605 /* Save time if the two types are the same. */
606
607 if (t1 == t2) return t1;
608
609 code1 = TREE_CODE (t1);
610 code2 = TREE_CODE (t2);
611
612 gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE
613 || code1 == FIXED_POINT_TYPE || code1 == REAL_TYPE
614 || code1 == INTEGER_TYPE);
615 gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE
616 || code2 == FIXED_POINT_TYPE || code2 == REAL_TYPE
617 || code2 == INTEGER_TYPE);
618
619 /* When one operand is a decimal float type, the other operand cannot be
620 a generic float type or a complex type. We also disallow vector types
621 here. */
622 if ((DECIMAL_FLOAT_TYPE_P (t1) || DECIMAL_FLOAT_TYPE_P (t2))
623 && !(DECIMAL_FLOAT_TYPE_P (t1) && DECIMAL_FLOAT_TYPE_P (t2)))
624 {
625 if (code1 == VECTOR_TYPE || code2 == VECTOR_TYPE)
626 {
627 error ("can%'t mix operands of decimal float and vector types");
628 return error_mark_node;
629 }
630 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
631 {
632 error ("can%'t mix operands of decimal float and complex types");
633 return error_mark_node;
634 }
635 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
636 {
637 error ("can%'t mix operands of decimal float and other float types");
638 return error_mark_node;
639 }
640 }
641
642 /* If one type is a vector type, return that type. (How the usual
643 arithmetic conversions apply to the vector types extension is not
644 precisely specified.) */
645 if (code1 == VECTOR_TYPE)
646 return t1;
647
648 if (code2 == VECTOR_TYPE)
649 return t2;
650
651 /* If one type is complex, form the common type of the non-complex
652 components, then make that complex. Use T1 or T2 if it is the
653 required type. */
654 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
655 {
656 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
657 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
658 tree subtype = c_common_type (subtype1, subtype2);
659
660 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
661 return t1;
662 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
663 return t2;
664 else
665 return build_complex_type (subtype);
666 }
667
668 /* If only one is real, use it as the result. */
669
670 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
671 return t1;
672
673 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
674 return t2;
675
676 /* If both are real and either are decimal floating point types, use
677 the decimal floating point type with the greater precision. */
678
679 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
680 {
681 if (TYPE_MAIN_VARIANT (t1) == dfloat128_type_node
682 || TYPE_MAIN_VARIANT (t2) == dfloat128_type_node)
683 return dfloat128_type_node;
684 else if (TYPE_MAIN_VARIANT (t1) == dfloat64_type_node
685 || TYPE_MAIN_VARIANT (t2) == dfloat64_type_node)
686 return dfloat64_type_node;
687 else if (TYPE_MAIN_VARIANT (t1) == dfloat32_type_node
688 || TYPE_MAIN_VARIANT (t2) == dfloat32_type_node)
689 return dfloat32_type_node;
690 }
691
692 /* Deal with fixed-point types. */
693 if (code1 == FIXED_POINT_TYPE || code2 == FIXED_POINT_TYPE)
694 {
695 unsigned int unsignedp = 0, satp = 0;
696 enum machine_mode m1, m2;
697 unsigned int fbit1, ibit1, fbit2, ibit2, max_fbit, max_ibit;
698
699 m1 = TYPE_MODE (t1);
700 m2 = TYPE_MODE (t2);
701
702 /* If one input type is saturating, the result type is saturating. */
703 if (TYPE_SATURATING (t1) || TYPE_SATURATING (t2))
704 satp = 1;
705
706 /* If both fixed-point types are unsigned, the result type is unsigned.
707 When mixing fixed-point and integer types, follow the sign of the
708 fixed-point type.
709 Otherwise, the result type is signed. */
710 if ((TYPE_UNSIGNED (t1) && TYPE_UNSIGNED (t2)
711 && code1 == FIXED_POINT_TYPE && code2 == FIXED_POINT_TYPE)
712 || (code1 == FIXED_POINT_TYPE && code2 != FIXED_POINT_TYPE
713 && TYPE_UNSIGNED (t1))
714 || (code1 != FIXED_POINT_TYPE && code2 == FIXED_POINT_TYPE
715 && TYPE_UNSIGNED (t2)))
716 unsignedp = 1;
717
718 /* The result type is signed. */
719 if (unsignedp == 0)
720 {
721 /* If the input type is unsigned, we need to convert to the
722 signed type. */
723 if (code1 == FIXED_POINT_TYPE && TYPE_UNSIGNED (t1))
724 {
725 enum mode_class mclass = (enum mode_class) 0;
726 if (GET_MODE_CLASS (m1) == MODE_UFRACT)
727 mclass = MODE_FRACT;
728 else if (GET_MODE_CLASS (m1) == MODE_UACCUM)
729 mclass = MODE_ACCUM;
730 else
731 gcc_unreachable ();
732 m1 = mode_for_size (GET_MODE_PRECISION (m1), mclass, 0);
733 }
734 if (code2 == FIXED_POINT_TYPE && TYPE_UNSIGNED (t2))
735 {
736 enum mode_class mclass = (enum mode_class) 0;
737 if (GET_MODE_CLASS (m2) == MODE_UFRACT)
738 mclass = MODE_FRACT;
739 else if (GET_MODE_CLASS (m2) == MODE_UACCUM)
740 mclass = MODE_ACCUM;
741 else
742 gcc_unreachable ();
743 m2 = mode_for_size (GET_MODE_PRECISION (m2), mclass, 0);
744 }
745 }
746
747 if (code1 == FIXED_POINT_TYPE)
748 {
749 fbit1 = GET_MODE_FBIT (m1);
750 ibit1 = GET_MODE_IBIT (m1);
751 }
752 else
753 {
754 fbit1 = 0;
755 /* Signed integers need to subtract one sign bit. */
756 ibit1 = TYPE_PRECISION (t1) - (!TYPE_UNSIGNED (t1));
757 }
758
759 if (code2 == FIXED_POINT_TYPE)
760 {
761 fbit2 = GET_MODE_FBIT (m2);
762 ibit2 = GET_MODE_IBIT (m2);
763 }
764 else
765 {
766 fbit2 = 0;
767 /* Signed integers need to subtract one sign bit. */
768 ibit2 = TYPE_PRECISION (t2) - (!TYPE_UNSIGNED (t2));
769 }
770
771 max_ibit = ibit1 >= ibit2 ? ibit1 : ibit2;
772 max_fbit = fbit1 >= fbit2 ? fbit1 : fbit2;
773 return c_common_fixed_point_type_for_size (max_ibit, max_fbit, unsignedp,
774 satp);
775 }
776
777 /* Both real or both integers; use the one with greater precision. */
778
779 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
780 return t1;
781 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
782 return t2;
783
784 /* Same precision. Prefer long longs to longs to ints when the
785 same precision, following the C99 rules on integer type rank
786 (which are equivalent to the C90 rules for C90 types). */
787
788 if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node
789 || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node)
790 return long_long_unsigned_type_node;
791
792 if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node
793 || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node)
794 {
795 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
796 return long_long_unsigned_type_node;
797 else
798 return long_long_integer_type_node;
799 }
800
801 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
802 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
803 return long_unsigned_type_node;
804
805 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
806 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
807 {
808 /* But preserve unsignedness from the other type,
809 since long cannot hold all the values of an unsigned int. */
810 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
811 return long_unsigned_type_node;
812 else
813 return long_integer_type_node;
814 }
815
816 /* Likewise, prefer long double to double even if same size. */
817 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
818 || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
819 return long_double_type_node;
820
821 /* Otherwise prefer the unsigned one. */
822
823 if (TYPE_UNSIGNED (t1))
824 return t1;
825 else
826 return t2;
827 }
828 \f
829 /* Wrapper around c_common_type that is used by c-common.c and other
830 front end optimizations that remove promotions. ENUMERAL_TYPEs
831 are allowed here and are converted to their compatible integer types.
832 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
833 preferably a non-Boolean type as the common type. */
834 tree
835 common_type (tree t1, tree t2)
836 {
837 if (TREE_CODE (t1) == ENUMERAL_TYPE)
838 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
839 if (TREE_CODE (t2) == ENUMERAL_TYPE)
840 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
841
842 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
843 if (TREE_CODE (t1) == BOOLEAN_TYPE
844 && TREE_CODE (t2) == BOOLEAN_TYPE)
845 return boolean_type_node;
846
847 /* If either type is BOOLEAN_TYPE, then return the other. */
848 if (TREE_CODE (t1) == BOOLEAN_TYPE)
849 return t2;
850 if (TREE_CODE (t2) == BOOLEAN_TYPE)
851 return t1;
852
853 return c_common_type (t1, t2);
854 }
855
856 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
857 or various other operations. Return 2 if they are compatible
858 but a warning may be needed if you use them together. */
859
860 int
861 comptypes (tree type1, tree type2)
862 {
863 const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base;
864 int val;
865
866 val = comptypes_internal (type1, type2);
867 free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1);
868
869 return val;
870 }
871 \f
872 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
873 or various other operations. Return 2 if they are compatible
874 but a warning may be needed if you use them together. This
875 differs from comptypes, in that we don't free the seen types. */
876
877 static int
878 comptypes_internal (const_tree type1, const_tree type2)
879 {
880 const_tree t1 = type1;
881 const_tree t2 = type2;
882 int attrval, val;
883
884 /* Suppress errors caused by previously reported errors. */
885
886 if (t1 == t2 || !t1 || !t2
887 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
888 return 1;
889
890 /* If either type is the internal version of sizetype, return the
891 language version. */
892 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
893 && TYPE_ORIG_SIZE_TYPE (t1))
894 t1 = TYPE_ORIG_SIZE_TYPE (t1);
895
896 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
897 && TYPE_ORIG_SIZE_TYPE (t2))
898 t2 = TYPE_ORIG_SIZE_TYPE (t2);
899
900
901 /* Enumerated types are compatible with integer types, but this is
902 not transitive: two enumerated types in the same translation unit
903 are compatible with each other only if they are the same type. */
904
905 if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE)
906 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1));
907 else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE)
908 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2));
909
910 if (t1 == t2)
911 return 1;
912
913 /* Different classes of types can't be compatible. */
914
915 if (TREE_CODE (t1) != TREE_CODE (t2))
916 return 0;
917
918 /* Qualifiers must match. C99 6.7.3p9 */
919
920 if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
921 return 0;
922
923 /* Allow for two different type nodes which have essentially the same
924 definition. Note that we already checked for equality of the type
925 qualifiers (just above). */
926
927 if (TREE_CODE (t1) != ARRAY_TYPE
928 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
929 return 1;
930
931 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
932 if (!(attrval = targetm.comp_type_attributes (t1, t2)))
933 return 0;
934
935 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
936 val = 0;
937
938 switch (TREE_CODE (t1))
939 {
940 case POINTER_TYPE:
941 /* Do not remove mode or aliasing information. */
942 if (TYPE_MODE (t1) != TYPE_MODE (t2)
943 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2))
944 break;
945 val = (TREE_TYPE (t1) == TREE_TYPE (t2)
946 ? 1 : comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2)));
947 break;
948
949 case FUNCTION_TYPE:
950 val = function_types_compatible_p (t1, t2);
951 break;
952
953 case ARRAY_TYPE:
954 {
955 tree d1 = TYPE_DOMAIN (t1);
956 tree d2 = TYPE_DOMAIN (t2);
957 bool d1_variable, d2_variable;
958 bool d1_zero, d2_zero;
959 val = 1;
960
961 /* Target types must match incl. qualifiers. */
962 if (TREE_TYPE (t1) != TREE_TYPE (t2)
963 && 0 == (val = comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2))))
964 return 0;
965
966 /* Sizes must match unless one is missing or variable. */
967 if (d1 == 0 || d2 == 0 || d1 == d2)
968 break;
969
970 d1_zero = !TYPE_MAX_VALUE (d1);
971 d2_zero = !TYPE_MAX_VALUE (d2);
972
973 d1_variable = (!d1_zero
974 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
975 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
976 d2_variable = (!d2_zero
977 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
978 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
979 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
980 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
981
982 if (d1_variable || d2_variable)
983 break;
984 if (d1_zero && d2_zero)
985 break;
986 if (d1_zero || d2_zero
987 || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
988 || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
989 val = 0;
990
991 break;
992 }
993
994 case ENUMERAL_TYPE:
995 case RECORD_TYPE:
996 case UNION_TYPE:
997 if (val != 1 && !same_translation_unit_p (t1, t2))
998 {
999 tree a1 = TYPE_ATTRIBUTES (t1);
1000 tree a2 = TYPE_ATTRIBUTES (t2);
1001
1002 if (! attribute_list_contained (a1, a2)
1003 && ! attribute_list_contained (a2, a1))
1004 break;
1005
1006 if (attrval != 2)
1007 return tagged_types_tu_compatible_p (t1, t2);
1008 val = tagged_types_tu_compatible_p (t1, t2);
1009 }
1010 break;
1011
1012 case VECTOR_TYPE:
1013 val = TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1014 && comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2));
1015 break;
1016
1017 default:
1018 break;
1019 }
1020 return attrval == 2 && val == 1 ? 2 : val;
1021 }
1022
1023 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
1024 ignoring their qualifiers. */
1025
1026 static int
1027 comp_target_types (tree ttl, tree ttr)
1028 {
1029 int val;
1030 tree mvl, mvr;
1031
1032 /* Do not lose qualifiers on element types of array types that are
1033 pointer targets by taking their TYPE_MAIN_VARIANT. */
1034 mvl = TREE_TYPE (ttl);
1035 mvr = TREE_TYPE (ttr);
1036 if (TREE_CODE (mvl) != ARRAY_TYPE)
1037 mvl = TYPE_MAIN_VARIANT (mvl);
1038 if (TREE_CODE (mvr) != ARRAY_TYPE)
1039 mvr = TYPE_MAIN_VARIANT (mvr);
1040 val = comptypes (mvl, mvr);
1041
1042 if (val == 2)
1043 pedwarn (input_location, OPT_pedantic, "types are not quite compatible");
1044 return val;
1045 }
1046 \f
1047 /* Subroutines of `comptypes'. */
1048
1049 /* Determine whether two trees derive from the same translation unit.
1050 If the CONTEXT chain ends in a null, that tree's context is still
1051 being parsed, so if two trees have context chains ending in null,
1052 they're in the same translation unit. */
1053 int
1054 same_translation_unit_p (const_tree t1, const_tree t2)
1055 {
1056 while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL)
1057 switch (TREE_CODE_CLASS (TREE_CODE (t1)))
1058 {
1059 case tcc_declaration:
1060 t1 = DECL_CONTEXT (t1); break;
1061 case tcc_type:
1062 t1 = TYPE_CONTEXT (t1); break;
1063 case tcc_exceptional:
1064 t1 = BLOCK_SUPERCONTEXT (t1); break; /* assume block */
1065 default: gcc_unreachable ();
1066 }
1067
1068 while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL)
1069 switch (TREE_CODE_CLASS (TREE_CODE (t2)))
1070 {
1071 case tcc_declaration:
1072 t2 = DECL_CONTEXT (t2); break;
1073 case tcc_type:
1074 t2 = TYPE_CONTEXT (t2); break;
1075 case tcc_exceptional:
1076 t2 = BLOCK_SUPERCONTEXT (t2); break; /* assume block */
1077 default: gcc_unreachable ();
1078 }
1079
1080 return t1 == t2;
1081 }
1082
1083 /* Allocate the seen two types, assuming that they are compatible. */
1084
1085 static struct tagged_tu_seen_cache *
1086 alloc_tagged_tu_seen_cache (const_tree t1, const_tree t2)
1087 {
1088 struct tagged_tu_seen_cache *tu = XNEW (struct tagged_tu_seen_cache);
1089 tu->next = tagged_tu_seen_base;
1090 tu->t1 = t1;
1091 tu->t2 = t2;
1092
1093 tagged_tu_seen_base = tu;
1094
1095 /* The C standard says that two structures in different translation
1096 units are compatible with each other only if the types of their
1097 fields are compatible (among other things). We assume that they
1098 are compatible until proven otherwise when building the cache.
1099 An example where this can occur is:
1100 struct a
1101 {
1102 struct a *next;
1103 };
1104 If we are comparing this against a similar struct in another TU,
1105 and did not assume they were compatible, we end up with an infinite
1106 loop. */
1107 tu->val = 1;
1108 return tu;
1109 }
1110
1111 /* Free the seen types until we get to TU_TIL. */
1112
1113 static void
1114 free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *tu_til)
1115 {
1116 const struct tagged_tu_seen_cache *tu = tagged_tu_seen_base;
1117 while (tu != tu_til)
1118 {
1119 const struct tagged_tu_seen_cache *const tu1
1120 = (const struct tagged_tu_seen_cache *) tu;
1121 tu = tu1->next;
1122 free (CONST_CAST (struct tagged_tu_seen_cache *, tu1));
1123 }
1124 tagged_tu_seen_base = tu_til;
1125 }
1126
1127 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1128 compatible. If the two types are not the same (which has been
1129 checked earlier), this can only happen when multiple translation
1130 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1131 rules. */
1132
1133 static int
1134 tagged_types_tu_compatible_p (const_tree t1, const_tree t2)
1135 {
1136 tree s1, s2;
1137 bool needs_warning = false;
1138
1139 /* We have to verify that the tags of the types are the same. This
1140 is harder than it looks because this may be a typedef, so we have
1141 to go look at the original type. It may even be a typedef of a
1142 typedef...
1143 In the case of compiler-created builtin structs the TYPE_DECL
1144 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1145 while (TYPE_NAME (t1)
1146 && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL
1147 && DECL_ORIGINAL_TYPE (TYPE_NAME (t1)))
1148 t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1));
1149
1150 while (TYPE_NAME (t2)
1151 && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL
1152 && DECL_ORIGINAL_TYPE (TYPE_NAME (t2)))
1153 t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2));
1154
1155 /* C90 didn't have the requirement that the two tags be the same. */
1156 if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2))
1157 return 0;
1158
1159 /* C90 didn't say what happened if one or both of the types were
1160 incomplete; we choose to follow C99 rules here, which is that they
1161 are compatible. */
1162 if (TYPE_SIZE (t1) == NULL
1163 || TYPE_SIZE (t2) == NULL)
1164 return 1;
1165
1166 {
1167 const struct tagged_tu_seen_cache * tts_i;
1168 for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next)
1169 if (tts_i->t1 == t1 && tts_i->t2 == t2)
1170 return tts_i->val;
1171 }
1172
1173 switch (TREE_CODE (t1))
1174 {
1175 case ENUMERAL_TYPE:
1176 {
1177 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1178 /* Speed up the case where the type values are in the same order. */
1179 tree tv1 = TYPE_VALUES (t1);
1180 tree tv2 = TYPE_VALUES (t2);
1181
1182 if (tv1 == tv2)
1183 {
1184 return 1;
1185 }
1186
1187 for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2))
1188 {
1189 if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2))
1190 break;
1191 if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1)
1192 {
1193 tu->val = 0;
1194 return 0;
1195 }
1196 }
1197
1198 if (tv1 == NULL_TREE && tv2 == NULL_TREE)
1199 {
1200 return 1;
1201 }
1202 if (tv1 == NULL_TREE || tv2 == NULL_TREE)
1203 {
1204 tu->val = 0;
1205 return 0;
1206 }
1207
1208 if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2)))
1209 {
1210 tu->val = 0;
1211 return 0;
1212 }
1213
1214 for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1))
1215 {
1216 s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2));
1217 if (s2 == NULL
1218 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1)
1219 {
1220 tu->val = 0;
1221 return 0;
1222 }
1223 }
1224 return 1;
1225 }
1226
1227 case UNION_TYPE:
1228 {
1229 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1230 if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2)))
1231 {
1232 tu->val = 0;
1233 return 0;
1234 }
1235
1236 /* Speed up the common case where the fields are in the same order. */
1237 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2;
1238 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1239 {
1240 int result;
1241
1242 if (DECL_NAME (s1) != DECL_NAME (s2))
1243 break;
1244 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1245
1246 if (result != 1 && !DECL_NAME (s1))
1247 break;
1248 if (result == 0)
1249 {
1250 tu->val = 0;
1251 return 0;
1252 }
1253 if (result == 2)
1254 needs_warning = true;
1255
1256 if (TREE_CODE (s1) == FIELD_DECL
1257 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1258 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1259 {
1260 tu->val = 0;
1261 return 0;
1262 }
1263 }
1264 if (!s1 && !s2)
1265 {
1266 tu->val = needs_warning ? 2 : 1;
1267 return tu->val;
1268 }
1269
1270 for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1))
1271 {
1272 bool ok = false;
1273
1274 for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2))
1275 if (DECL_NAME (s1) == DECL_NAME (s2))
1276 {
1277 int result;
1278
1279 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1280
1281 if (result != 1 && !DECL_NAME (s1))
1282 continue;
1283 if (result == 0)
1284 {
1285 tu->val = 0;
1286 return 0;
1287 }
1288 if (result == 2)
1289 needs_warning = true;
1290
1291 if (TREE_CODE (s1) == FIELD_DECL
1292 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1293 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1294 break;
1295
1296 ok = true;
1297 break;
1298 }
1299 if (!ok)
1300 {
1301 tu->val = 0;
1302 return 0;
1303 }
1304 }
1305 tu->val = needs_warning ? 2 : 10;
1306 return tu->val;
1307 }
1308
1309 case RECORD_TYPE:
1310 {
1311 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1312
1313 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2);
1314 s1 && s2;
1315 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1316 {
1317 int result;
1318 if (TREE_CODE (s1) != TREE_CODE (s2)
1319 || DECL_NAME (s1) != DECL_NAME (s2))
1320 break;
1321 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1322 if (result == 0)
1323 break;
1324 if (result == 2)
1325 needs_warning = true;
1326
1327 if (TREE_CODE (s1) == FIELD_DECL
1328 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1329 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1330 break;
1331 }
1332 if (s1 && s2)
1333 tu->val = 0;
1334 else
1335 tu->val = needs_warning ? 2 : 1;
1336 return tu->val;
1337 }
1338
1339 default:
1340 gcc_unreachable ();
1341 }
1342 }
1343
1344 /* Return 1 if two function types F1 and F2 are compatible.
1345 If either type specifies no argument types,
1346 the other must specify a fixed number of self-promoting arg types.
1347 Otherwise, if one type specifies only the number of arguments,
1348 the other must specify that number of self-promoting arg types.
1349 Otherwise, the argument types must match. */
1350
1351 static int
1352 function_types_compatible_p (const_tree f1, const_tree f2)
1353 {
1354 tree args1, args2;
1355 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1356 int val = 1;
1357 int val1;
1358 tree ret1, ret2;
1359
1360 ret1 = TREE_TYPE (f1);
1361 ret2 = TREE_TYPE (f2);
1362
1363 /* 'volatile' qualifiers on a function's return type used to mean
1364 the function is noreturn. */
1365 if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2))
1366 pedwarn (input_location, 0, "function return types not compatible due to %<volatile%>");
1367 if (TYPE_VOLATILE (ret1))
1368 ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1),
1369 TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE);
1370 if (TYPE_VOLATILE (ret2))
1371 ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2),
1372 TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE);
1373 val = comptypes_internal (ret1, ret2);
1374 if (val == 0)
1375 return 0;
1376
1377 args1 = TYPE_ARG_TYPES (f1);
1378 args2 = TYPE_ARG_TYPES (f2);
1379
1380 /* An unspecified parmlist matches any specified parmlist
1381 whose argument types don't need default promotions. */
1382
1383 if (args1 == 0)
1384 {
1385 if (!self_promoting_args_p (args2))
1386 return 0;
1387 /* If one of these types comes from a non-prototype fn definition,
1388 compare that with the other type's arglist.
1389 If they don't match, ask for a warning (but no error). */
1390 if (TYPE_ACTUAL_ARG_TYPES (f1)
1391 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
1392 val = 2;
1393 return val;
1394 }
1395 if (args2 == 0)
1396 {
1397 if (!self_promoting_args_p (args1))
1398 return 0;
1399 if (TYPE_ACTUAL_ARG_TYPES (f2)
1400 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
1401 val = 2;
1402 return val;
1403 }
1404
1405 /* Both types have argument lists: compare them and propagate results. */
1406 val1 = type_lists_compatible_p (args1, args2);
1407 return val1 != 1 ? val1 : val;
1408 }
1409
1410 /* Check two lists of types for compatibility,
1411 returning 0 for incompatible, 1 for compatible,
1412 or 2 for compatible with warning. */
1413
1414 static int
1415 type_lists_compatible_p (const_tree args1, const_tree args2)
1416 {
1417 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1418 int val = 1;
1419 int newval = 0;
1420
1421 while (1)
1422 {
1423 tree a1, mv1, a2, mv2;
1424 if (args1 == 0 && args2 == 0)
1425 return val;
1426 /* If one list is shorter than the other,
1427 they fail to match. */
1428 if (args1 == 0 || args2 == 0)
1429 return 0;
1430 mv1 = a1 = TREE_VALUE (args1);
1431 mv2 = a2 = TREE_VALUE (args2);
1432 if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE)
1433 mv1 = TYPE_MAIN_VARIANT (mv1);
1434 if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE)
1435 mv2 = TYPE_MAIN_VARIANT (mv2);
1436 /* A null pointer instead of a type
1437 means there is supposed to be an argument
1438 but nothing is specified about what type it has.
1439 So match anything that self-promotes. */
1440 if (a1 == 0)
1441 {
1442 if (c_type_promotes_to (a2) != a2)
1443 return 0;
1444 }
1445 else if (a2 == 0)
1446 {
1447 if (c_type_promotes_to (a1) != a1)
1448 return 0;
1449 }
1450 /* If one of the lists has an error marker, ignore this arg. */
1451 else if (TREE_CODE (a1) == ERROR_MARK
1452 || TREE_CODE (a2) == ERROR_MARK)
1453 ;
1454 else if (!(newval = comptypes_internal (mv1, mv2)))
1455 {
1456 /* Allow wait (union {union wait *u; int *i} *)
1457 and wait (union wait *) to be compatible. */
1458 if (TREE_CODE (a1) == UNION_TYPE
1459 && (TYPE_NAME (a1) == 0
1460 || TYPE_TRANSPARENT_UNION (a1))
1461 && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST
1462 && tree_int_cst_equal (TYPE_SIZE (a1),
1463 TYPE_SIZE (a2)))
1464 {
1465 tree memb;
1466 for (memb = TYPE_FIELDS (a1);
1467 memb; memb = TREE_CHAIN (memb))
1468 {
1469 tree mv3 = TREE_TYPE (memb);
1470 if (mv3 && mv3 != error_mark_node
1471 && TREE_CODE (mv3) != ARRAY_TYPE)
1472 mv3 = TYPE_MAIN_VARIANT (mv3);
1473 if (comptypes_internal (mv3, mv2))
1474 break;
1475 }
1476 if (memb == 0)
1477 return 0;
1478 }
1479 else if (TREE_CODE (a2) == UNION_TYPE
1480 && (TYPE_NAME (a2) == 0
1481 || TYPE_TRANSPARENT_UNION (a2))
1482 && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST
1483 && tree_int_cst_equal (TYPE_SIZE (a2),
1484 TYPE_SIZE (a1)))
1485 {
1486 tree memb;
1487 for (memb = TYPE_FIELDS (a2);
1488 memb; memb = TREE_CHAIN (memb))
1489 {
1490 tree mv3 = TREE_TYPE (memb);
1491 if (mv3 && mv3 != error_mark_node
1492 && TREE_CODE (mv3) != ARRAY_TYPE)
1493 mv3 = TYPE_MAIN_VARIANT (mv3);
1494 if (comptypes_internal (mv3, mv1))
1495 break;
1496 }
1497 if (memb == 0)
1498 return 0;
1499 }
1500 else
1501 return 0;
1502 }
1503
1504 /* comptypes said ok, but record if it said to warn. */
1505 if (newval > val)
1506 val = newval;
1507
1508 args1 = TREE_CHAIN (args1);
1509 args2 = TREE_CHAIN (args2);
1510 }
1511 }
1512 \f
1513 /* Compute the size to increment a pointer by. */
1514
1515 static tree
1516 c_size_in_bytes (const_tree type)
1517 {
1518 enum tree_code code = TREE_CODE (type);
1519
1520 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
1521 return size_one_node;
1522
1523 if (!COMPLETE_OR_VOID_TYPE_P (type))
1524 {
1525 error ("arithmetic on pointer to an incomplete type");
1526 return size_one_node;
1527 }
1528
1529 /* Convert in case a char is more than one unit. */
1530 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
1531 size_int (TYPE_PRECISION (char_type_node)
1532 / BITS_PER_UNIT));
1533 }
1534 \f
1535 /* Return either DECL or its known constant value (if it has one). */
1536
1537 tree
1538 decl_constant_value (tree decl)
1539 {
1540 if (/* Don't change a variable array bound or initial value to a constant
1541 in a place where a variable is invalid. Note that DECL_INITIAL
1542 isn't valid for a PARM_DECL. */
1543 current_function_decl != 0
1544 && TREE_CODE (decl) != PARM_DECL
1545 && !TREE_THIS_VOLATILE (decl)
1546 && TREE_READONLY (decl)
1547 && DECL_INITIAL (decl) != 0
1548 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
1549 /* This is invalid if initial value is not constant.
1550 If it has either a function call, a memory reference,
1551 or a variable, then re-evaluating it could give different results. */
1552 && TREE_CONSTANT (DECL_INITIAL (decl))
1553 /* Check for cases where this is sub-optimal, even though valid. */
1554 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
1555 return DECL_INITIAL (decl);
1556 return decl;
1557 }
1558
1559 /* Return either DECL or its known constant value (if it has one), but
1560 return DECL if pedantic or DECL has mode BLKmode. This is for
1561 bug-compatibility with the old behavior of decl_constant_value
1562 (before GCC 3.0); every use of this function is a bug and it should
1563 be removed before GCC 3.1. It is not appropriate to use pedantic
1564 in a way that affects optimization, and BLKmode is probably not the
1565 right test for avoiding misoptimizations either. */
1566
1567 static tree
1568 decl_constant_value_for_broken_optimization (tree decl)
1569 {
1570 tree ret;
1571
1572 if (pedantic || DECL_MODE (decl) == BLKmode)
1573 return decl;
1574
1575 ret = decl_constant_value (decl);
1576 /* Avoid unwanted tree sharing between the initializer and current
1577 function's body where the tree can be modified e.g. by the
1578 gimplifier. */
1579 if (ret != decl && TREE_STATIC (decl))
1580 ret = unshare_expr (ret);
1581 return ret;
1582 }
1583
1584 /* Convert the array expression EXP to a pointer. */
1585 static tree
1586 array_to_pointer_conversion (tree exp)
1587 {
1588 tree orig_exp = exp;
1589 tree type = TREE_TYPE (exp);
1590 tree adr;
1591 tree restype = TREE_TYPE (type);
1592 tree ptrtype;
1593
1594 gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
1595
1596 STRIP_TYPE_NOPS (exp);
1597
1598 if (TREE_NO_WARNING (orig_exp))
1599 TREE_NO_WARNING (exp) = 1;
1600
1601 ptrtype = build_pointer_type (restype);
1602
1603 if (TREE_CODE (exp) == INDIRECT_REF)
1604 return convert (ptrtype, TREE_OPERAND (exp, 0));
1605
1606 if (TREE_CODE (exp) == VAR_DECL)
1607 {
1608 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1609 ADDR_EXPR because it's the best way of representing what
1610 happens in C when we take the address of an array and place
1611 it in a pointer to the element type. */
1612 adr = build1 (ADDR_EXPR, ptrtype, exp);
1613 if (!c_mark_addressable (exp))
1614 return error_mark_node;
1615 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
1616 return adr;
1617 }
1618
1619 /* This way is better for a COMPONENT_REF since it can
1620 simplify the offset for a component. */
1621 adr = build_unary_op (ADDR_EXPR, exp, 1);
1622 return convert (ptrtype, adr);
1623 }
1624
1625 /* Convert the function expression EXP to a pointer. */
1626 static tree
1627 function_to_pointer_conversion (tree exp)
1628 {
1629 tree orig_exp = exp;
1630
1631 gcc_assert (TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE);
1632
1633 STRIP_TYPE_NOPS (exp);
1634
1635 if (TREE_NO_WARNING (orig_exp))
1636 TREE_NO_WARNING (exp) = 1;
1637
1638 return build_unary_op (ADDR_EXPR, exp, 0);
1639 }
1640
1641 /* Perform the default conversion of arrays and functions to pointers.
1642 Return the result of converting EXP. For any other expression, just
1643 return EXP after removing NOPs. */
1644
1645 struct c_expr
1646 default_function_array_conversion (struct c_expr exp)
1647 {
1648 tree orig_exp = exp.value;
1649 tree type = TREE_TYPE (exp.value);
1650 enum tree_code code = TREE_CODE (type);
1651
1652 switch (code)
1653 {
1654 case ARRAY_TYPE:
1655 {
1656 bool not_lvalue = false;
1657 bool lvalue_array_p;
1658
1659 while ((TREE_CODE (exp.value) == NON_LVALUE_EXPR
1660 || CONVERT_EXPR_P (exp.value))
1661 && TREE_TYPE (TREE_OPERAND (exp.value, 0)) == type)
1662 {
1663 if (TREE_CODE (exp.value) == NON_LVALUE_EXPR)
1664 not_lvalue = true;
1665 exp.value = TREE_OPERAND (exp.value, 0);
1666 }
1667
1668 if (TREE_NO_WARNING (orig_exp))
1669 TREE_NO_WARNING (exp.value) = 1;
1670
1671 lvalue_array_p = !not_lvalue && lvalue_p (exp.value);
1672 if (!flag_isoc99 && !lvalue_array_p)
1673 {
1674 /* Before C99, non-lvalue arrays do not decay to pointers.
1675 Normally, using such an array would be invalid; but it can
1676 be used correctly inside sizeof or as a statement expression.
1677 Thus, do not give an error here; an error will result later. */
1678 return exp;
1679 }
1680
1681 exp.value = array_to_pointer_conversion (exp.value);
1682 }
1683 break;
1684 case FUNCTION_TYPE:
1685 exp.value = function_to_pointer_conversion (exp.value);
1686 break;
1687 default:
1688 STRIP_TYPE_NOPS (exp.value);
1689 if (TREE_NO_WARNING (orig_exp))
1690 TREE_NO_WARNING (exp.value) = 1;
1691 break;
1692 }
1693
1694 return exp;
1695 }
1696
1697
1698 /* EXP is an expression of integer type. Apply the integer promotions
1699 to it and return the promoted value. */
1700
1701 tree
1702 perform_integral_promotions (tree exp)
1703 {
1704 tree type = TREE_TYPE (exp);
1705 enum tree_code code = TREE_CODE (type);
1706
1707 gcc_assert (INTEGRAL_TYPE_P (type));
1708
1709 /* Normally convert enums to int,
1710 but convert wide enums to something wider. */
1711 if (code == ENUMERAL_TYPE)
1712 {
1713 type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
1714 TYPE_PRECISION (integer_type_node)),
1715 ((TYPE_PRECISION (type)
1716 >= TYPE_PRECISION (integer_type_node))
1717 && TYPE_UNSIGNED (type)));
1718
1719 return convert (type, exp);
1720 }
1721
1722 /* ??? This should no longer be needed now bit-fields have their
1723 proper types. */
1724 if (TREE_CODE (exp) == COMPONENT_REF
1725 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
1726 /* If it's thinner than an int, promote it like a
1727 c_promoting_integer_type_p, otherwise leave it alone. */
1728 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
1729 TYPE_PRECISION (integer_type_node)))
1730 return convert (integer_type_node, exp);
1731
1732 if (c_promoting_integer_type_p (type))
1733 {
1734 /* Preserve unsignedness if not really getting any wider. */
1735 if (TYPE_UNSIGNED (type)
1736 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
1737 return convert (unsigned_type_node, exp);
1738
1739 return convert (integer_type_node, exp);
1740 }
1741
1742 return exp;
1743 }
1744
1745
1746 /* Perform default promotions for C data used in expressions.
1747 Enumeral types or short or char are converted to int.
1748 In addition, manifest constants symbols are replaced by their values. */
1749
1750 tree
1751 default_conversion (tree exp)
1752 {
1753 tree orig_exp;
1754 tree type = TREE_TYPE (exp);
1755 enum tree_code code = TREE_CODE (type);
1756
1757 /* Functions and arrays have been converted during parsing. */
1758 gcc_assert (code != FUNCTION_TYPE);
1759 if (code == ARRAY_TYPE)
1760 return exp;
1761
1762 /* Constants can be used directly unless they're not loadable. */
1763 if (TREE_CODE (exp) == CONST_DECL)
1764 exp = DECL_INITIAL (exp);
1765
1766 /* Replace a nonvolatile const static variable with its value unless
1767 it is an array, in which case we must be sure that taking the
1768 address of the array produces consistent results. */
1769 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE)
1770 {
1771 exp = decl_constant_value_for_broken_optimization (exp);
1772 type = TREE_TYPE (exp);
1773 }
1774
1775 /* Strip no-op conversions. */
1776 orig_exp = exp;
1777 STRIP_TYPE_NOPS (exp);
1778
1779 if (TREE_NO_WARNING (orig_exp))
1780 TREE_NO_WARNING (exp) = 1;
1781
1782 if (code == VOID_TYPE)
1783 {
1784 error ("void value not ignored as it ought to be");
1785 return error_mark_node;
1786 }
1787
1788 exp = require_complete_type (exp);
1789 if (exp == error_mark_node)
1790 return error_mark_node;
1791
1792 if (INTEGRAL_TYPE_P (type))
1793 return perform_integral_promotions (exp);
1794
1795 return exp;
1796 }
1797 \f
1798 /* Look up COMPONENT in a structure or union DECL.
1799
1800 If the component name is not found, returns NULL_TREE. Otherwise,
1801 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1802 stepping down the chain to the component, which is in the last
1803 TREE_VALUE of the list. Normally the list is of length one, but if
1804 the component is embedded within (nested) anonymous structures or
1805 unions, the list steps down the chain to the component. */
1806
1807 static tree
1808 lookup_field (tree decl, tree component)
1809 {
1810 tree type = TREE_TYPE (decl);
1811 tree field;
1812
1813 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1814 to the field elements. Use a binary search on this array to quickly
1815 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1816 will always be set for structures which have many elements. */
1817
1818 if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s)
1819 {
1820 int bot, top, half;
1821 tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0];
1822
1823 field = TYPE_FIELDS (type);
1824 bot = 0;
1825 top = TYPE_LANG_SPECIFIC (type)->s->len;
1826 while (top - bot > 1)
1827 {
1828 half = (top - bot + 1) >> 1;
1829 field = field_array[bot+half];
1830
1831 if (DECL_NAME (field) == NULL_TREE)
1832 {
1833 /* Step through all anon unions in linear fashion. */
1834 while (DECL_NAME (field_array[bot]) == NULL_TREE)
1835 {
1836 field = field_array[bot++];
1837 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1838 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1839 {
1840 tree anon = lookup_field (field, component);
1841
1842 if (anon)
1843 return tree_cons (NULL_TREE, field, anon);
1844 }
1845 }
1846
1847 /* Entire record is only anon unions. */
1848 if (bot > top)
1849 return NULL_TREE;
1850
1851 /* Restart the binary search, with new lower bound. */
1852 continue;
1853 }
1854
1855 if (DECL_NAME (field) == component)
1856 break;
1857 if (DECL_NAME (field) < component)
1858 bot += half;
1859 else
1860 top = bot + half;
1861 }
1862
1863 if (DECL_NAME (field_array[bot]) == component)
1864 field = field_array[bot];
1865 else if (DECL_NAME (field) != component)
1866 return NULL_TREE;
1867 }
1868 else
1869 {
1870 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1871 {
1872 if (DECL_NAME (field) == NULL_TREE
1873 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1874 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
1875 {
1876 tree anon = lookup_field (field, component);
1877
1878 if (anon)
1879 return tree_cons (NULL_TREE, field, anon);
1880 }
1881
1882 if (DECL_NAME (field) == component)
1883 break;
1884 }
1885
1886 if (field == NULL_TREE)
1887 return NULL_TREE;
1888 }
1889
1890 return tree_cons (NULL_TREE, field, NULL_TREE);
1891 }
1892
1893 /* Make an expression to refer to the COMPONENT field of
1894 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1895
1896 tree
1897 build_component_ref (tree datum, tree component)
1898 {
1899 tree type = TREE_TYPE (datum);
1900 enum tree_code code = TREE_CODE (type);
1901 tree field = NULL;
1902 tree ref;
1903
1904 if (!objc_is_public (datum, component))
1905 return error_mark_node;
1906
1907 /* See if there is a field or component with name COMPONENT. */
1908
1909 if (code == RECORD_TYPE || code == UNION_TYPE)
1910 {
1911 if (!COMPLETE_TYPE_P (type))
1912 {
1913 c_incomplete_type_error (NULL_TREE, type);
1914 return error_mark_node;
1915 }
1916
1917 field = lookup_field (datum, component);
1918
1919 if (!field)
1920 {
1921 error ("%qT has no member named %qE", type, component);
1922 return error_mark_node;
1923 }
1924
1925 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1926 This might be better solved in future the way the C++ front
1927 end does it - by giving the anonymous entities each a
1928 separate name and type, and then have build_component_ref
1929 recursively call itself. We can't do that here. */
1930 do
1931 {
1932 tree subdatum = TREE_VALUE (field);
1933 int quals;
1934 tree subtype;
1935
1936 if (TREE_TYPE (subdatum) == error_mark_node)
1937 return error_mark_node;
1938
1939 quals = TYPE_QUALS (strip_array_types (TREE_TYPE (subdatum)));
1940 quals |= TYPE_QUALS (TREE_TYPE (datum));
1941 subtype = c_build_qualified_type (TREE_TYPE (subdatum), quals);
1942
1943 ref = build3 (COMPONENT_REF, subtype, datum, subdatum,
1944 NULL_TREE);
1945 if (TREE_READONLY (datum) || TREE_READONLY (subdatum))
1946 TREE_READONLY (ref) = 1;
1947 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
1948 TREE_THIS_VOLATILE (ref) = 1;
1949
1950 if (TREE_DEPRECATED (subdatum))
1951 warn_deprecated_use (subdatum);
1952
1953 datum = ref;
1954
1955 field = TREE_CHAIN (field);
1956 }
1957 while (field);
1958
1959 return ref;
1960 }
1961 else if (code != ERROR_MARK)
1962 error ("request for member %qE in something not a structure or union",
1963 component);
1964
1965 return error_mark_node;
1966 }
1967 \f
1968 /* Given an expression PTR for a pointer, return an expression
1969 for the value pointed to.
1970 ERRORSTRING is the name of the operator to appear in error messages.
1971
1972 LOC is the location to use for the generated tree. */
1973
1974 tree
1975 build_indirect_ref (tree ptr, const char *errorstring, location_t loc)
1976 {
1977 tree pointer = default_conversion (ptr);
1978 tree type = TREE_TYPE (pointer);
1979 tree ref;
1980
1981 if (TREE_CODE (type) == POINTER_TYPE)
1982 {
1983 if (CONVERT_EXPR_P (pointer)
1984 || TREE_CODE (pointer) == VIEW_CONVERT_EXPR)
1985 {
1986 /* If a warning is issued, mark it to avoid duplicates from
1987 the backend. This only needs to be done at
1988 warn_strict_aliasing > 2. */
1989 if (warn_strict_aliasing > 2)
1990 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (pointer, 0)),
1991 type, TREE_OPERAND (pointer, 0)))
1992 TREE_NO_WARNING (pointer) = 1;
1993 }
1994
1995 if (TREE_CODE (pointer) == ADDR_EXPR
1996 && (TREE_TYPE (TREE_OPERAND (pointer, 0))
1997 == TREE_TYPE (type)))
1998 {
1999 ref = TREE_OPERAND (pointer, 0);
2000 protected_set_expr_location (ref, loc);
2001 return ref;
2002 }
2003 else
2004 {
2005 tree t = TREE_TYPE (type);
2006
2007 ref = build1 (INDIRECT_REF, t, pointer);
2008
2009 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
2010 {
2011 error ("dereferencing pointer to incomplete type");
2012 return error_mark_node;
2013 }
2014 if (VOID_TYPE_P (t) && skip_evaluation == 0)
2015 warning (0, "dereferencing %<void *%> pointer");
2016
2017 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2018 so that we get the proper error message if the result is used
2019 to assign to. Also, &* is supposed to be a no-op.
2020 And ANSI C seems to specify that the type of the result
2021 should be the const type. */
2022 /* A de-reference of a pointer to const is not a const. It is valid
2023 to change it via some other pointer. */
2024 TREE_READONLY (ref) = TYPE_READONLY (t);
2025 TREE_SIDE_EFFECTS (ref)
2026 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
2027 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
2028 protected_set_expr_location (ref, loc);
2029 return ref;
2030 }
2031 }
2032 else if (TREE_CODE (pointer) != ERROR_MARK)
2033 error ("invalid type argument of %qs (have %qT)", errorstring, type);
2034 return error_mark_node;
2035 }
2036
2037 /* This handles expressions of the form "a[i]", which denotes
2038 an array reference.
2039
2040 This is logically equivalent in C to *(a+i), but we may do it differently.
2041 If A is a variable or a member, we generate a primitive ARRAY_REF.
2042 This avoids forcing the array out of registers, and can work on
2043 arrays that are not lvalues (for example, members of structures returned
2044 by functions).
2045
2046 LOC is the location to use for the returned expression. */
2047
2048 tree
2049 build_array_ref (tree array, tree index, location_t loc)
2050 {
2051 tree ret;
2052 bool swapped = false;
2053 if (TREE_TYPE (array) == error_mark_node
2054 || TREE_TYPE (index) == error_mark_node)
2055 return error_mark_node;
2056
2057 if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE
2058 && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE)
2059 {
2060 tree temp;
2061 if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE
2062 && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE)
2063 {
2064 error ("subscripted value is neither array nor pointer");
2065 return error_mark_node;
2066 }
2067 temp = array;
2068 array = index;
2069 index = temp;
2070 swapped = true;
2071 }
2072
2073 if (!INTEGRAL_TYPE_P (TREE_TYPE (index)))
2074 {
2075 error ("array subscript is not an integer");
2076 return error_mark_node;
2077 }
2078
2079 if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE)
2080 {
2081 error ("subscripted value is pointer to function");
2082 return error_mark_node;
2083 }
2084
2085 /* ??? Existing practice has been to warn only when the char
2086 index is syntactically the index, not for char[array]. */
2087 if (!swapped)
2088 warn_array_subscript_with_type_char (index);
2089
2090 /* Apply default promotions *after* noticing character types. */
2091 index = default_conversion (index);
2092
2093 gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
2094
2095 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2096 {
2097 tree rval, type;
2098
2099 /* An array that is indexed by a non-constant
2100 cannot be stored in a register; we must be able to do
2101 address arithmetic on its address.
2102 Likewise an array of elements of variable size. */
2103 if (TREE_CODE (index) != INTEGER_CST
2104 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2105 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
2106 {
2107 if (!c_mark_addressable (array))
2108 return error_mark_node;
2109 }
2110 /* An array that is indexed by a constant value which is not within
2111 the array bounds cannot be stored in a register either; because we
2112 would get a crash in store_bit_field/extract_bit_field when trying
2113 to access a non-existent part of the register. */
2114 if (TREE_CODE (index) == INTEGER_CST
2115 && TYPE_DOMAIN (TREE_TYPE (array))
2116 && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array))))
2117 {
2118 if (!c_mark_addressable (array))
2119 return error_mark_node;
2120 }
2121
2122 if (pedantic)
2123 {
2124 tree foo = array;
2125 while (TREE_CODE (foo) == COMPONENT_REF)
2126 foo = TREE_OPERAND (foo, 0);
2127 if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
2128 pedwarn (input_location, OPT_pedantic,
2129 "ISO C forbids subscripting %<register%> array");
2130 else if (!flag_isoc99 && !lvalue_p (foo))
2131 pedwarn (input_location, OPT_pedantic,
2132 "ISO C90 forbids subscripting non-lvalue array");
2133 }
2134
2135 type = TREE_TYPE (TREE_TYPE (array));
2136 rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE);
2137 /* Array ref is const/volatile if the array elements are
2138 or if the array is. */
2139 TREE_READONLY (rval)
2140 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
2141 | TREE_READONLY (array));
2142 TREE_SIDE_EFFECTS (rval)
2143 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2144 | TREE_SIDE_EFFECTS (array));
2145 TREE_THIS_VOLATILE (rval)
2146 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2147 /* This was added by rms on 16 Nov 91.
2148 It fixes vol struct foo *a; a->elts[1]
2149 in an inline function.
2150 Hope it doesn't break something else. */
2151 | TREE_THIS_VOLATILE (array));
2152 ret = require_complete_type (fold (rval));
2153 protected_set_expr_location (ret, loc);
2154 return ret;
2155 }
2156 else
2157 {
2158 tree ar = default_conversion (array);
2159
2160 if (ar == error_mark_node)
2161 return ar;
2162
2163 gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE);
2164 gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE);
2165
2166 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0),
2167 "array indexing", loc);
2168 }
2169 }
2170 \f
2171 /* Build an external reference to identifier ID. FUN indicates
2172 whether this will be used for a function call. LOC is the source
2173 location of the identifier. */
2174 tree
2175 build_external_ref (tree id, int fun, location_t loc)
2176 {
2177 tree ref;
2178 tree decl = lookup_name (id);
2179
2180 /* In Objective-C, an instance variable (ivar) may be preferred to
2181 whatever lookup_name() found. */
2182 decl = objc_lookup_ivar (decl, id);
2183
2184 if (decl && decl != error_mark_node)
2185 ref = decl;
2186 else if (fun)
2187 /* Implicit function declaration. */
2188 ref = implicitly_declare (id);
2189 else if (decl == error_mark_node)
2190 /* Don't complain about something that's already been
2191 complained about. */
2192 return error_mark_node;
2193 else
2194 {
2195 undeclared_variable (id, loc);
2196 return error_mark_node;
2197 }
2198
2199 if (TREE_TYPE (ref) == error_mark_node)
2200 return error_mark_node;
2201
2202 if (TREE_DEPRECATED (ref))
2203 warn_deprecated_use (ref);
2204
2205 /* Recursive call does not count as usage. */
2206 if (ref != current_function_decl)
2207 {
2208 TREE_USED (ref) = 1;
2209 }
2210
2211 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof)
2212 {
2213 if (!in_sizeof && !in_typeof)
2214 C_DECL_USED (ref) = 1;
2215 else if (DECL_INITIAL (ref) == 0
2216 && DECL_EXTERNAL (ref)
2217 && !TREE_PUBLIC (ref))
2218 record_maybe_used_decl (ref);
2219 }
2220
2221 if (TREE_CODE (ref) == CONST_DECL)
2222 {
2223 used_types_insert (TREE_TYPE (ref));
2224 ref = DECL_INITIAL (ref);
2225 TREE_CONSTANT (ref) = 1;
2226 }
2227 else if (current_function_decl != 0
2228 && !DECL_FILE_SCOPE_P (current_function_decl)
2229 && (TREE_CODE (ref) == VAR_DECL
2230 || TREE_CODE (ref) == PARM_DECL
2231 || TREE_CODE (ref) == FUNCTION_DECL))
2232 {
2233 tree context = decl_function_context (ref);
2234
2235 if (context != 0 && context != current_function_decl)
2236 DECL_NONLOCAL (ref) = 1;
2237 }
2238 /* C99 6.7.4p3: An inline definition of a function with external
2239 linkage ... shall not contain a reference to an identifier with
2240 internal linkage. */
2241 else if (current_function_decl != 0
2242 && DECL_DECLARED_INLINE_P (current_function_decl)
2243 && DECL_EXTERNAL (current_function_decl)
2244 && VAR_OR_FUNCTION_DECL_P (ref)
2245 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref))
2246 && ! TREE_PUBLIC (ref)
2247 && DECL_CONTEXT (ref) != current_function_decl)
2248 pedwarn (loc, 0, "%qD is static but used in inline function %qD "
2249 "which is not static", ref, current_function_decl);
2250
2251 return ref;
2252 }
2253
2254 /* Record details of decls possibly used inside sizeof or typeof. */
2255 struct maybe_used_decl
2256 {
2257 /* The decl. */
2258 tree decl;
2259 /* The level seen at (in_sizeof + in_typeof). */
2260 int level;
2261 /* The next one at this level or above, or NULL. */
2262 struct maybe_used_decl *next;
2263 };
2264
2265 static struct maybe_used_decl *maybe_used_decls;
2266
2267 /* Record that DECL, an undefined static function reference seen
2268 inside sizeof or typeof, might be used if the operand of sizeof is
2269 a VLA type or the operand of typeof is a variably modified
2270 type. */
2271
2272 static void
2273 record_maybe_used_decl (tree decl)
2274 {
2275 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2276 t->decl = decl;
2277 t->level = in_sizeof + in_typeof;
2278 t->next = maybe_used_decls;
2279 maybe_used_decls = t;
2280 }
2281
2282 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2283 USED is false, just discard them. If it is true, mark them used
2284 (if no longer inside sizeof or typeof) or move them to the next
2285 level up (if still inside sizeof or typeof). */
2286
2287 void
2288 pop_maybe_used (bool used)
2289 {
2290 struct maybe_used_decl *p = maybe_used_decls;
2291 int cur_level = in_sizeof + in_typeof;
2292 while (p && p->level > cur_level)
2293 {
2294 if (used)
2295 {
2296 if (cur_level == 0)
2297 C_DECL_USED (p->decl) = 1;
2298 else
2299 p->level = cur_level;
2300 }
2301 p = p->next;
2302 }
2303 if (!used || cur_level == 0)
2304 maybe_used_decls = p;
2305 }
2306
2307 /* Return the result of sizeof applied to EXPR. */
2308
2309 struct c_expr
2310 c_expr_sizeof_expr (struct c_expr expr)
2311 {
2312 struct c_expr ret;
2313 if (expr.value == error_mark_node)
2314 {
2315 ret.value = error_mark_node;
2316 ret.original_code = ERROR_MARK;
2317 pop_maybe_used (false);
2318 }
2319 else
2320 {
2321 ret.value = c_sizeof (TREE_TYPE (expr.value));
2322 ret.original_code = ERROR_MARK;
2323 if (c_vla_type_p (TREE_TYPE (expr.value)))
2324 {
2325 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2326 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2327 }
2328 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2329 }
2330 return ret;
2331 }
2332
2333 /* Return the result of sizeof applied to T, a structure for the type
2334 name passed to sizeof (rather than the type itself). */
2335
2336 struct c_expr
2337 c_expr_sizeof_type (struct c_type_name *t)
2338 {
2339 tree type;
2340 struct c_expr ret;
2341 type = groktypename (t);
2342 ret.value = c_sizeof (type);
2343 ret.original_code = ERROR_MARK;
2344 pop_maybe_used (type != error_mark_node
2345 ? C_TYPE_VARIABLE_SIZE (type) : false);
2346 return ret;
2347 }
2348
2349 /* Build a function call to function FUNCTION with parameters PARAMS.
2350 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2351 TREE_VALUE of each node is a parameter-expression.
2352 FUNCTION's data type may be a function type or a pointer-to-function. */
2353
2354 tree
2355 build_function_call (tree function, tree params)
2356 {
2357 tree fntype, fundecl = 0;
2358 tree name = NULL_TREE, result;
2359 tree tem;
2360 int nargs;
2361 tree *argarray;
2362
2363
2364 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2365 STRIP_TYPE_NOPS (function);
2366
2367 /* Convert anything with function type to a pointer-to-function. */
2368 if (TREE_CODE (function) == FUNCTION_DECL)
2369 {
2370 /* Implement type-directed function overloading for builtins.
2371 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2372 handle all the type checking. The result is a complete expression
2373 that implements this function call. */
2374 tem = resolve_overloaded_builtin (function, params);
2375 if (tem)
2376 return tem;
2377
2378 name = DECL_NAME (function);
2379 fundecl = function;
2380 }
2381 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2382 function = function_to_pointer_conversion (function);
2383
2384 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2385 expressions, like those used for ObjC messenger dispatches. */
2386 function = objc_rewrite_function_call (function, params);
2387
2388 fntype = TREE_TYPE (function);
2389
2390 if (TREE_CODE (fntype) == ERROR_MARK)
2391 return error_mark_node;
2392
2393 if (!(TREE_CODE (fntype) == POINTER_TYPE
2394 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2395 {
2396 error ("called object %qE is not a function", function);
2397 return error_mark_node;
2398 }
2399
2400 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2401 current_function_returns_abnormally = 1;
2402
2403 /* fntype now gets the type of function pointed to. */
2404 fntype = TREE_TYPE (fntype);
2405
2406 /* Check that the function is called through a compatible prototype.
2407 If it is not, replace the call by a trap, wrapped up in a compound
2408 expression if necessary. This has the nice side-effect to prevent
2409 the tree-inliner from generating invalid assignment trees which may
2410 blow up in the RTL expander later. */
2411 if (CONVERT_EXPR_P (function)
2412 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2413 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2414 && !comptypes (fntype, TREE_TYPE (tem)))
2415 {
2416 tree return_type = TREE_TYPE (fntype);
2417 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2418 NULL_TREE);
2419
2420 /* This situation leads to run-time undefined behavior. We can't,
2421 therefore, simply error unless we can prove that all possible
2422 executions of the program must execute the code. */
2423 if (warning (0, "function called through a non-compatible type"))
2424 /* We can, however, treat "undefined" any way we please.
2425 Call abort to encourage the user to fix the program. */
2426 inform (input_location, "if this code is reached, the program will abort");
2427
2428 if (VOID_TYPE_P (return_type))
2429 return trap;
2430 else
2431 {
2432 tree rhs;
2433
2434 if (AGGREGATE_TYPE_P (return_type))
2435 rhs = build_compound_literal (return_type,
2436 build_constructor (return_type, 0));
2437 else
2438 rhs = fold_convert (return_type, integer_zero_node);
2439
2440 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2441 }
2442 }
2443
2444 /* Convert the parameters to the types declared in the
2445 function prototype, or apply default promotions. */
2446
2447 nargs = list_length (params);
2448 argarray = (tree *) alloca (nargs * sizeof (tree));
2449 nargs = convert_arguments (nargs, argarray, TYPE_ARG_TYPES (fntype),
2450 params, function, fundecl);
2451 if (nargs < 0)
2452 return error_mark_node;
2453
2454 /* Check that arguments to builtin functions match the expectations. */
2455 if (fundecl
2456 && DECL_BUILT_IN (fundecl)
2457 && DECL_BUILT_IN_CLASS (fundecl) == BUILT_IN_NORMAL
2458 && !check_builtin_function_arguments (fundecl, nargs, argarray))
2459 return error_mark_node;
2460
2461 /* Check that the arguments to the function are valid. */
2462 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2463 TYPE_ARG_TYPES (fntype));
2464
2465 if (require_constant_value)
2466 {
2467 result = fold_build_call_array_initializer (TREE_TYPE (fntype),
2468 function, nargs, argarray);
2469 if (TREE_CONSTANT (result)
2470 && (name == NULL_TREE
2471 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2472 pedwarn_init (input_location, 0, "initializer element is not constant");
2473 }
2474 else
2475 result = fold_build_call_array (TREE_TYPE (fntype),
2476 function, nargs, argarray);
2477
2478 if (VOID_TYPE_P (TREE_TYPE (result)))
2479 return result;
2480 return require_complete_type (result);
2481 }
2482 \f
2483 /* Convert the argument expressions in the list VALUES
2484 to the types in the list TYPELIST. The resulting arguments are
2485 stored in the array ARGARRAY which has size NARGS.
2486
2487 If TYPELIST is exhausted, or when an element has NULL as its type,
2488 perform the default conversions.
2489
2490 PARMLIST is the chain of parm decls for the function being called.
2491 It may be 0, if that info is not available.
2492 It is used only for generating error messages.
2493
2494 FUNCTION is a tree for the called function. It is used only for
2495 error messages, where it is formatted with %qE.
2496
2497 This is also where warnings about wrong number of args are generated.
2498
2499 VALUES is a chain of TREE_LIST nodes with the elements of the list
2500 in the TREE_VALUE slots of those nodes.
2501
2502 Returns the actual number of arguments processed (which may be less
2503 than NARGS in some error situations), or -1 on failure. */
2504
2505 static int
2506 convert_arguments (int nargs, tree *argarray,
2507 tree typelist, tree values, tree function, tree fundecl)
2508 {
2509 tree typetail, valtail;
2510 int parmnum;
2511 const bool type_generic = fundecl
2512 && lookup_attribute ("type generic", TYPE_ATTRIBUTES(TREE_TYPE (fundecl)));
2513 tree selector;
2514
2515 /* Change pointer to function to the function itself for
2516 diagnostics. */
2517 if (TREE_CODE (function) == ADDR_EXPR
2518 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2519 function = TREE_OPERAND (function, 0);
2520
2521 /* Handle an ObjC selector specially for diagnostics. */
2522 selector = objc_message_selector ();
2523
2524 /* Scan the given expressions and types, producing individual
2525 converted arguments and storing them in ARGARRAY. */
2526
2527 for (valtail = values, typetail = typelist, parmnum = 0;
2528 valtail;
2529 valtail = TREE_CHAIN (valtail), parmnum++)
2530 {
2531 tree type = typetail ? TREE_VALUE (typetail) : 0;
2532 tree val = TREE_VALUE (valtail);
2533 tree rname = function;
2534 int argnum = parmnum + 1;
2535 const char *invalid_func_diag;
2536
2537 if (type == void_type_node)
2538 {
2539 error ("too many arguments to function %qE", function);
2540 return parmnum;
2541 }
2542
2543 if (selector && argnum > 2)
2544 {
2545 rname = selector;
2546 argnum -= 2;
2547 }
2548
2549 STRIP_TYPE_NOPS (val);
2550
2551 val = require_complete_type (val);
2552
2553 if (type != 0)
2554 {
2555 /* Formal parm type is specified by a function prototype. */
2556 tree parmval;
2557
2558 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2559 {
2560 error ("type of formal parameter %d is incomplete", parmnum + 1);
2561 parmval = val;
2562 }
2563 else
2564 {
2565 /* Optionally warn about conversions that
2566 differ from the default conversions. */
2567 if (warn_traditional_conversion || warn_traditional)
2568 {
2569 unsigned int formal_prec = TYPE_PRECISION (type);
2570
2571 if (INTEGRAL_TYPE_P (type)
2572 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2573 warning (0, "passing argument %d of %qE as integer "
2574 "rather than floating due to prototype",
2575 argnum, rname);
2576 if (INTEGRAL_TYPE_P (type)
2577 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2578 warning (0, "passing argument %d of %qE as integer "
2579 "rather than complex due to prototype",
2580 argnum, rname);
2581 else if (TREE_CODE (type) == COMPLEX_TYPE
2582 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2583 warning (0, "passing argument %d of %qE as complex "
2584 "rather than floating due to prototype",
2585 argnum, rname);
2586 else if (TREE_CODE (type) == REAL_TYPE
2587 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2588 warning (0, "passing argument %d of %qE as floating "
2589 "rather than integer due to prototype",
2590 argnum, rname);
2591 else if (TREE_CODE (type) == COMPLEX_TYPE
2592 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2593 warning (0, "passing argument %d of %qE as complex "
2594 "rather than integer due to prototype",
2595 argnum, rname);
2596 else if (TREE_CODE (type) == REAL_TYPE
2597 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2598 warning (0, "passing argument %d of %qE as floating "
2599 "rather than complex due to prototype",
2600 argnum, rname);
2601 /* ??? At some point, messages should be written about
2602 conversions between complex types, but that's too messy
2603 to do now. */
2604 else if (TREE_CODE (type) == REAL_TYPE
2605 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2606 {
2607 /* Warn if any argument is passed as `float',
2608 since without a prototype it would be `double'. */
2609 if (formal_prec == TYPE_PRECISION (float_type_node)
2610 && type != dfloat32_type_node)
2611 warning (0, "passing argument %d of %qE as %<float%> "
2612 "rather than %<double%> due to prototype",
2613 argnum, rname);
2614
2615 /* Warn if mismatch between argument and prototype
2616 for decimal float types. Warn of conversions with
2617 binary float types and of precision narrowing due to
2618 prototype. */
2619 else if (type != TREE_TYPE (val)
2620 && (type == dfloat32_type_node
2621 || type == dfloat64_type_node
2622 || type == dfloat128_type_node
2623 || TREE_TYPE (val) == dfloat32_type_node
2624 || TREE_TYPE (val) == dfloat64_type_node
2625 || TREE_TYPE (val) == dfloat128_type_node)
2626 && (formal_prec
2627 <= TYPE_PRECISION (TREE_TYPE (val))
2628 || (type == dfloat128_type_node
2629 && (TREE_TYPE (val)
2630 != dfloat64_type_node
2631 && (TREE_TYPE (val)
2632 != dfloat32_type_node)))
2633 || (type == dfloat64_type_node
2634 && (TREE_TYPE (val)
2635 != dfloat32_type_node))))
2636 warning (0, "passing argument %d of %qE as %qT "
2637 "rather than %qT due to prototype",
2638 argnum, rname, type, TREE_TYPE (val));
2639
2640 }
2641 /* Detect integer changing in width or signedness.
2642 These warnings are only activated with
2643 -Wtraditional-conversion, not with -Wtraditional. */
2644 else if (warn_traditional_conversion && INTEGRAL_TYPE_P (type)
2645 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2646 {
2647 tree would_have_been = default_conversion (val);
2648 tree type1 = TREE_TYPE (would_have_been);
2649
2650 if (TREE_CODE (type) == ENUMERAL_TYPE
2651 && (TYPE_MAIN_VARIANT (type)
2652 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2653 /* No warning if function asks for enum
2654 and the actual arg is that enum type. */
2655 ;
2656 else if (formal_prec != TYPE_PRECISION (type1))
2657 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2658 "with different width due to prototype",
2659 argnum, rname);
2660 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2661 ;
2662 /* Don't complain if the formal parameter type
2663 is an enum, because we can't tell now whether
2664 the value was an enum--even the same enum. */
2665 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2666 ;
2667 else if (TREE_CODE (val) == INTEGER_CST
2668 && int_fits_type_p (val, type))
2669 /* Change in signedness doesn't matter
2670 if a constant value is unaffected. */
2671 ;
2672 /* If the value is extended from a narrower
2673 unsigned type, it doesn't matter whether we
2674 pass it as signed or unsigned; the value
2675 certainly is the same either way. */
2676 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2677 && TYPE_UNSIGNED (TREE_TYPE (val)))
2678 ;
2679 else if (TYPE_UNSIGNED (type))
2680 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2681 "as unsigned due to prototype",
2682 argnum, rname);
2683 else
2684 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2685 "as signed due to prototype", argnum, rname);
2686 }
2687 }
2688
2689 parmval = convert_for_assignment (type, val, ic_argpass,
2690 fundecl, function,
2691 parmnum + 1);
2692
2693 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2694 && INTEGRAL_TYPE_P (type)
2695 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2696 parmval = default_conversion (parmval);
2697 }
2698 argarray[parmnum] = parmval;
2699 }
2700 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2701 && (TYPE_PRECISION (TREE_TYPE (val))
2702 < TYPE_PRECISION (double_type_node))
2703 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2704 {
2705 if (type_generic)
2706 argarray[parmnum] = val;
2707 else
2708 /* Convert `float' to `double'. */
2709 argarray[parmnum] = convert (double_type_node, val);
2710 }
2711 else if ((invalid_func_diag =
2712 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2713 {
2714 error (invalid_func_diag);
2715 return -1;
2716 }
2717 else
2718 /* Convert `short' and `char' to full-size `int'. */
2719 argarray[parmnum] = default_conversion (val);
2720
2721 if (typetail)
2722 typetail = TREE_CHAIN (typetail);
2723 }
2724
2725 gcc_assert (parmnum == nargs);
2726
2727 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2728 {
2729 error ("too few arguments to function %qE", function);
2730 return -1;
2731 }
2732
2733 return parmnum;
2734 }
2735 \f
2736 /* This is the entry point used by the parser to build unary operators
2737 in the input. CODE, a tree_code, specifies the unary operator, and
2738 ARG is the operand. For unary plus, the C parser currently uses
2739 CONVERT_EXPR for code.
2740
2741 LOC is the location to use for the tree generated.
2742 */
2743
2744 struct c_expr
2745 parser_build_unary_op (enum tree_code code, struct c_expr arg, location_t loc)
2746 {
2747 struct c_expr result;
2748
2749 result.original_code = ERROR_MARK;
2750 result.value = build_unary_op (code, arg.value, 0);
2751 protected_set_expr_location (result.value, loc);
2752
2753 if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value))
2754 overflow_warning (result.value);
2755
2756 return result;
2757 }
2758
2759 /* This is the entry point used by the parser to build binary operators
2760 in the input. CODE, a tree_code, specifies the binary operator, and
2761 ARG1 and ARG2 are the operands. In addition to constructing the
2762 expression, we check for operands that were written with other binary
2763 operators in a way that is likely to confuse the user. */
2764
2765 struct c_expr
2766 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2767 struct c_expr arg2)
2768 {
2769 struct c_expr result;
2770
2771 enum tree_code code1 = arg1.original_code;
2772 enum tree_code code2 = arg2.original_code;
2773
2774 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2775 result.original_code = code;
2776
2777 if (TREE_CODE (result.value) == ERROR_MARK)
2778 return result;
2779
2780 /* Check for cases such as x+y<<z which users are likely
2781 to misinterpret. */
2782 if (warn_parentheses)
2783 warn_about_parentheses (code, code1, code2);
2784
2785 if (TREE_CODE_CLASS (code1) != tcc_comparison)
2786 warn_logical_operator (code, arg1.value, arg2.value);
2787
2788 /* Warn about comparisons against string literals, with the exception
2789 of testing for equality or inequality of a string literal with NULL. */
2790 if (code == EQ_EXPR || code == NE_EXPR)
2791 {
2792 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2793 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2794 warning (OPT_Waddress, "comparison with string literal results in unspecified behavior");
2795 }
2796 else if (TREE_CODE_CLASS (code) == tcc_comparison
2797 && (code1 == STRING_CST || code2 == STRING_CST))
2798 warning (OPT_Waddress, "comparison with string literal results in unspecified behavior");
2799
2800 if (TREE_OVERFLOW_P (result.value)
2801 && !TREE_OVERFLOW_P (arg1.value)
2802 && !TREE_OVERFLOW_P (arg2.value))
2803 overflow_warning (result.value);
2804
2805 return result;
2806 }
2807 \f
2808 /* Return a tree for the difference of pointers OP0 and OP1.
2809 The resulting tree has type int. */
2810
2811 static tree
2812 pointer_diff (tree op0, tree op1)
2813 {
2814 tree restype = ptrdiff_type_node;
2815
2816 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2817 tree con0, con1, lit0, lit1;
2818 tree orig_op1 = op1;
2819
2820 if (TREE_CODE (target_type) == VOID_TYPE)
2821 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
2822 "pointer of type %<void *%> used in subtraction");
2823 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2824 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
2825 "pointer to a function used in subtraction");
2826
2827 /* If the conversion to ptrdiff_type does anything like widening or
2828 converting a partial to an integral mode, we get a convert_expression
2829 that is in the way to do any simplifications.
2830 (fold-const.c doesn't know that the extra bits won't be needed.
2831 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2832 different mode in place.)
2833 So first try to find a common term here 'by hand'; we want to cover
2834 at least the cases that occur in legal static initializers. */
2835 if (CONVERT_EXPR_P (op0)
2836 && (TYPE_PRECISION (TREE_TYPE (op0))
2837 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2838 con0 = TREE_OPERAND (op0, 0);
2839 else
2840 con0 = op0;
2841 if (CONVERT_EXPR_P (op1)
2842 && (TYPE_PRECISION (TREE_TYPE (op1))
2843 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2844 con1 = TREE_OPERAND (op1, 0);
2845 else
2846 con1 = op1;
2847
2848 if (TREE_CODE (con0) == PLUS_EXPR)
2849 {
2850 lit0 = TREE_OPERAND (con0, 1);
2851 con0 = TREE_OPERAND (con0, 0);
2852 }
2853 else
2854 lit0 = integer_zero_node;
2855
2856 if (TREE_CODE (con1) == PLUS_EXPR)
2857 {
2858 lit1 = TREE_OPERAND (con1, 1);
2859 con1 = TREE_OPERAND (con1, 0);
2860 }
2861 else
2862 lit1 = integer_zero_node;
2863
2864 if (operand_equal_p (con0, con1, 0))
2865 {
2866 op0 = lit0;
2867 op1 = lit1;
2868 }
2869
2870
2871 /* First do the subtraction as integers;
2872 then drop through to build the divide operator.
2873 Do not do default conversions on the minus operator
2874 in case restype is a short type. */
2875
2876 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2877 convert (restype, op1), 0);
2878 /* This generates an error if op1 is pointer to incomplete type. */
2879 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2880 error ("arithmetic on pointer to an incomplete type");
2881
2882 /* This generates an error if op0 is pointer to incomplete type. */
2883 op1 = c_size_in_bytes (target_type);
2884
2885 /* Divide by the size, in easiest possible way. */
2886 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2887 }
2888 \f
2889 /* Construct and perhaps optimize a tree representation
2890 for a unary operation. CODE, a tree_code, specifies the operation
2891 and XARG is the operand.
2892 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2893 the default promotions (such as from short to int).
2894 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2895 allows non-lvalues; this is only used to handle conversion of non-lvalue
2896 arrays to pointers in C99. */
2897
2898 tree
2899 build_unary_op (enum tree_code code, tree xarg, int flag)
2900 {
2901 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2902 tree arg = xarg;
2903 tree argtype = 0;
2904 enum tree_code typecode;
2905 tree val;
2906 int noconvert = flag;
2907 const char *invalid_op_diag;
2908
2909 if (code != ADDR_EXPR)
2910 arg = require_complete_type (arg);
2911
2912 typecode = TREE_CODE (TREE_TYPE (arg));
2913 if (typecode == ERROR_MARK)
2914 return error_mark_node;
2915 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2916 typecode = INTEGER_TYPE;
2917
2918 if ((invalid_op_diag
2919 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2920 {
2921 error (invalid_op_diag);
2922 return error_mark_node;
2923 }
2924
2925 switch (code)
2926 {
2927 case CONVERT_EXPR:
2928 /* This is used for unary plus, because a CONVERT_EXPR
2929 is enough to prevent anybody from looking inside for
2930 associativity, but won't generate any code. */
2931 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2932 || typecode == FIXED_POINT_TYPE || typecode == COMPLEX_TYPE
2933 || typecode == VECTOR_TYPE))
2934 {
2935 error ("wrong type argument to unary plus");
2936 return error_mark_node;
2937 }
2938 else if (!noconvert)
2939 arg = default_conversion (arg);
2940 arg = non_lvalue (arg);
2941 break;
2942
2943 case NEGATE_EXPR:
2944 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2945 || typecode == FIXED_POINT_TYPE || typecode == COMPLEX_TYPE
2946 || typecode == VECTOR_TYPE))
2947 {
2948 error ("wrong type argument to unary minus");
2949 return error_mark_node;
2950 }
2951 else if (!noconvert)
2952 arg = default_conversion (arg);
2953 break;
2954
2955 case BIT_NOT_EXPR:
2956 /* ~ works on integer types and non float vectors. */
2957 if (typecode == INTEGER_TYPE
2958 || (typecode == VECTOR_TYPE
2959 && !VECTOR_FLOAT_TYPE_P (TREE_TYPE (arg))))
2960 {
2961 if (!noconvert)
2962 arg = default_conversion (arg);
2963 }
2964 else if (typecode == COMPLEX_TYPE)
2965 {
2966 code = CONJ_EXPR;
2967 pedwarn (input_location, OPT_pedantic,
2968 "ISO C does not support %<~%> for complex conjugation");
2969 if (!noconvert)
2970 arg = default_conversion (arg);
2971 }
2972 else
2973 {
2974 error ("wrong type argument to bit-complement");
2975 return error_mark_node;
2976 }
2977 break;
2978
2979 case ABS_EXPR:
2980 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2981 {
2982 error ("wrong type argument to abs");
2983 return error_mark_node;
2984 }
2985 else if (!noconvert)
2986 arg = default_conversion (arg);
2987 break;
2988
2989 case CONJ_EXPR:
2990 /* Conjugating a real value is a no-op, but allow it anyway. */
2991 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2992 || typecode == COMPLEX_TYPE))
2993 {
2994 error ("wrong type argument to conjugation");
2995 return error_mark_node;
2996 }
2997 else if (!noconvert)
2998 arg = default_conversion (arg);
2999 break;
3000
3001 case TRUTH_NOT_EXPR:
3002 if (typecode != INTEGER_TYPE && typecode != FIXED_POINT_TYPE
3003 && typecode != REAL_TYPE && typecode != POINTER_TYPE
3004 && typecode != COMPLEX_TYPE)
3005 {
3006 error ("wrong type argument to unary exclamation mark");
3007 return error_mark_node;
3008 }
3009 arg = c_objc_common_truthvalue_conversion (arg);
3010 return invert_truthvalue (arg);
3011
3012 case REALPART_EXPR:
3013 if (TREE_CODE (arg) == COMPLEX_CST)
3014 return TREE_REALPART (arg);
3015 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3016 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3017 else
3018 return arg;
3019
3020 case IMAGPART_EXPR:
3021 if (TREE_CODE (arg) == COMPLEX_CST)
3022 return TREE_IMAGPART (arg);
3023 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3024 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3025 else
3026 return convert (TREE_TYPE (arg), integer_zero_node);
3027
3028 case PREINCREMENT_EXPR:
3029 case POSTINCREMENT_EXPR:
3030 case PREDECREMENT_EXPR:
3031 case POSTDECREMENT_EXPR:
3032
3033 /* Increment or decrement the real part of the value,
3034 and don't change the imaginary part. */
3035 if (typecode == COMPLEX_TYPE)
3036 {
3037 tree real, imag;
3038
3039 pedwarn (input_location, OPT_pedantic,
3040 "ISO C does not support %<++%> and %<--%> on complex types");
3041
3042 arg = stabilize_reference (arg);
3043 real = build_unary_op (REALPART_EXPR, arg, 1);
3044 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3045 real = build_unary_op (code, real, 1);
3046 if (real == error_mark_node || imag == error_mark_node)
3047 return error_mark_node;
3048 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3049 real, imag);
3050 }
3051
3052 /* Report invalid types. */
3053
3054 if (typecode != POINTER_TYPE && typecode != FIXED_POINT_TYPE
3055 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
3056 {
3057 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3058 error ("wrong type argument to increment");
3059 else
3060 error ("wrong type argument to decrement");
3061
3062 return error_mark_node;
3063 }
3064
3065 {
3066 tree inc;
3067 tree result_type = TREE_TYPE (arg);
3068
3069 arg = get_unwidened (arg, 0);
3070 argtype = TREE_TYPE (arg);
3071
3072 /* Compute the increment. */
3073
3074 if (typecode == POINTER_TYPE)
3075 {
3076 /* If pointer target is an undefined struct,
3077 we just cannot know how to do the arithmetic. */
3078 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
3079 {
3080 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3081 error ("increment of pointer to unknown structure");
3082 else
3083 error ("decrement of pointer to unknown structure");
3084 }
3085 else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
3086 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
3087 {
3088 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3089 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3090 "wrong type argument to increment");
3091 else
3092 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3093 "wrong type argument to decrement");
3094 }
3095
3096 inc = c_size_in_bytes (TREE_TYPE (result_type));
3097 inc = fold_convert (sizetype, inc);
3098 }
3099 else if (FRACT_MODE_P (TYPE_MODE (result_type)))
3100 {
3101 /* For signed fract types, we invert ++ to -- or
3102 -- to ++, and change inc from 1 to -1, because
3103 it is not possible to represent 1 in signed fract constants.
3104 For unsigned fract types, the result always overflows and
3105 we get an undefined (original) or the maximum value. */
3106 if (code == PREINCREMENT_EXPR)
3107 code = PREDECREMENT_EXPR;
3108 else if (code == PREDECREMENT_EXPR)
3109 code = PREINCREMENT_EXPR;
3110 else if (code == POSTINCREMENT_EXPR)
3111 code = POSTDECREMENT_EXPR;
3112 else /* code == POSTDECREMENT_EXPR */
3113 code = POSTINCREMENT_EXPR;
3114
3115 inc = integer_minus_one_node;
3116 inc = convert (argtype, inc);
3117 }
3118 else
3119 {
3120 inc = integer_one_node;
3121 inc = convert (argtype, inc);
3122 }
3123
3124 /* Complain about anything else that is not a true lvalue. */
3125 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3126 || code == POSTINCREMENT_EXPR)
3127 ? lv_increment
3128 : lv_decrement)))
3129 return error_mark_node;
3130
3131 /* Report a read-only lvalue. */
3132 if (TREE_READONLY (arg))
3133 {
3134 readonly_error (arg,
3135 ((code == PREINCREMENT_EXPR
3136 || code == POSTINCREMENT_EXPR)
3137 ? lv_increment : lv_decrement));
3138 return error_mark_node;
3139 }
3140
3141 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3142 val = boolean_increment (code, arg);
3143 else
3144 val = build2 (code, TREE_TYPE (arg), arg, inc);
3145 TREE_SIDE_EFFECTS (val) = 1;
3146 val = convert (result_type, val);
3147 if (TREE_CODE (val) != code)
3148 TREE_NO_WARNING (val) = 1;
3149 return val;
3150 }
3151
3152 case ADDR_EXPR:
3153 /* Note that this operation never does default_conversion. */
3154
3155 /* Let &* cancel out to simplify resulting code. */
3156 if (TREE_CODE (arg) == INDIRECT_REF)
3157 {
3158 /* Don't let this be an lvalue. */
3159 if (lvalue_p (TREE_OPERAND (arg, 0)))
3160 return non_lvalue (TREE_OPERAND (arg, 0));
3161 return TREE_OPERAND (arg, 0);
3162 }
3163
3164 /* For &x[y], return x+y */
3165 if (TREE_CODE (arg) == ARRAY_REF)
3166 {
3167 tree op0 = TREE_OPERAND (arg, 0);
3168 if (!c_mark_addressable (op0))
3169 return error_mark_node;
3170 return build_binary_op (PLUS_EXPR,
3171 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
3172 ? array_to_pointer_conversion (op0)
3173 : op0),
3174 TREE_OPERAND (arg, 1), 1);
3175 }
3176
3177 /* Anything not already handled and not a true memory reference
3178 or a non-lvalue array is an error. */
3179 else if (typecode != FUNCTION_TYPE && !flag
3180 && !lvalue_or_else (arg, lv_addressof))
3181 return error_mark_node;
3182
3183 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3184 argtype = TREE_TYPE (arg);
3185
3186 /* If the lvalue is const or volatile, merge that into the type
3187 to which the address will point. Note that you can't get a
3188 restricted pointer by taking the address of something, so we
3189 only have to deal with `const' and `volatile' here. */
3190 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3191 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3192 argtype = c_build_type_variant (argtype,
3193 TREE_READONLY (arg),
3194 TREE_THIS_VOLATILE (arg));
3195
3196 if (!c_mark_addressable (arg))
3197 return error_mark_node;
3198
3199 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3200 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3201
3202 argtype = build_pointer_type (argtype);
3203
3204 /* ??? Cope with user tricks that amount to offsetof. Delete this
3205 when we have proper support for integer constant expressions. */
3206 val = get_base_address (arg);
3207 if (val && TREE_CODE (val) == INDIRECT_REF
3208 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3209 {
3210 tree op0 = fold_convert (sizetype, fold_offsetof (arg, val)), op1;
3211
3212 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3213 return fold_build2 (POINTER_PLUS_EXPR, argtype, op1, op0);
3214 }
3215
3216 val = build1 (ADDR_EXPR, argtype, arg);
3217
3218 return val;
3219
3220 default:
3221 gcc_unreachable ();
3222 }
3223
3224 if (argtype == 0)
3225 argtype = TREE_TYPE (arg);
3226 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3227 : fold_build1 (code, argtype, arg);
3228 }
3229
3230 /* Return nonzero if REF is an lvalue valid for this language.
3231 Lvalues can be assigned, unless their type has TYPE_READONLY.
3232 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3233
3234 static int
3235 lvalue_p (const_tree ref)
3236 {
3237 const enum tree_code code = TREE_CODE (ref);
3238
3239 switch (code)
3240 {
3241 case REALPART_EXPR:
3242 case IMAGPART_EXPR:
3243 case COMPONENT_REF:
3244 return lvalue_p (TREE_OPERAND (ref, 0));
3245
3246 case COMPOUND_LITERAL_EXPR:
3247 case STRING_CST:
3248 return 1;
3249
3250 case INDIRECT_REF:
3251 case ARRAY_REF:
3252 case VAR_DECL:
3253 case PARM_DECL:
3254 case RESULT_DECL:
3255 case ERROR_MARK:
3256 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3257 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3258
3259 case BIND_EXPR:
3260 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3261
3262 default:
3263 return 0;
3264 }
3265 }
3266 \f
3267 /* Give an error for storing in something that is 'const'. */
3268
3269 static void
3270 readonly_error (tree arg, enum lvalue_use use)
3271 {
3272 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3273 || use == lv_asm);
3274 /* Using this macro rather than (for example) arrays of messages
3275 ensures that all the format strings are checked at compile
3276 time. */
3277 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3278 : (use == lv_increment ? (I) \
3279 : (use == lv_decrement ? (D) : (AS))))
3280 if (TREE_CODE (arg) == COMPONENT_REF)
3281 {
3282 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3283 readonly_error (TREE_OPERAND (arg, 0), use);
3284 else
3285 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3286 G_("increment of read-only member %qD"),
3287 G_("decrement of read-only member %qD"),
3288 G_("read-only member %qD used as %<asm%> output")),
3289 TREE_OPERAND (arg, 1));
3290 }
3291 else if (TREE_CODE (arg) == VAR_DECL)
3292 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3293 G_("increment of read-only variable %qD"),
3294 G_("decrement of read-only variable %qD"),
3295 G_("read-only variable %qD used as %<asm%> output")),
3296 arg);
3297 else
3298 error (READONLY_MSG (G_("assignment of read-only location %qE"),
3299 G_("increment of read-only location %qE"),
3300 G_("decrement of read-only location %qE"),
3301 G_("read-only location %qE used as %<asm%> output")),
3302 arg);
3303 }
3304
3305
3306 /* Return nonzero if REF is an lvalue valid for this language;
3307 otherwise, print an error message and return zero. USE says
3308 how the lvalue is being used and so selects the error message. */
3309
3310 static int
3311 lvalue_or_else (const_tree ref, enum lvalue_use use)
3312 {
3313 int win = lvalue_p (ref);
3314
3315 if (!win)
3316 lvalue_error (use);
3317
3318 return win;
3319 }
3320 \f
3321 /* Mark EXP saying that we need to be able to take the
3322 address of it; it should not be allocated in a register.
3323 Returns true if successful. */
3324
3325 bool
3326 c_mark_addressable (tree exp)
3327 {
3328 tree x = exp;
3329
3330 while (1)
3331 switch (TREE_CODE (x))
3332 {
3333 case COMPONENT_REF:
3334 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3335 {
3336 error
3337 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3338 return false;
3339 }
3340
3341 /* ... fall through ... */
3342
3343 case ADDR_EXPR:
3344 case ARRAY_REF:
3345 case REALPART_EXPR:
3346 case IMAGPART_EXPR:
3347 x = TREE_OPERAND (x, 0);
3348 break;
3349
3350 case COMPOUND_LITERAL_EXPR:
3351 case CONSTRUCTOR:
3352 TREE_ADDRESSABLE (x) = 1;
3353 return true;
3354
3355 case VAR_DECL:
3356 case CONST_DECL:
3357 case PARM_DECL:
3358 case RESULT_DECL:
3359 if (C_DECL_REGISTER (x)
3360 && DECL_NONLOCAL (x))
3361 {
3362 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3363 {
3364 error
3365 ("global register variable %qD used in nested function", x);
3366 return false;
3367 }
3368 pedwarn (input_location, 0, "register variable %qD used in nested function", x);
3369 }
3370 else if (C_DECL_REGISTER (x))
3371 {
3372 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3373 error ("address of global register variable %qD requested", x);
3374 else
3375 error ("address of register variable %qD requested", x);
3376 return false;
3377 }
3378
3379 /* drops in */
3380 case FUNCTION_DECL:
3381 TREE_ADDRESSABLE (x) = 1;
3382 /* drops out */
3383 default:
3384 return true;
3385 }
3386 }
3387 \f
3388 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3389
3390 tree
3391 build_conditional_expr (tree ifexp, tree op1, tree op2)
3392 {
3393 tree type1;
3394 tree type2;
3395 enum tree_code code1;
3396 enum tree_code code2;
3397 tree result_type = NULL;
3398 tree orig_op1 = op1, orig_op2 = op2;
3399
3400 /* Promote both alternatives. */
3401
3402 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3403 op1 = default_conversion (op1);
3404 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3405 op2 = default_conversion (op2);
3406
3407 if (TREE_CODE (ifexp) == ERROR_MARK
3408 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3409 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3410 return error_mark_node;
3411
3412 type1 = TREE_TYPE (op1);
3413 code1 = TREE_CODE (type1);
3414 type2 = TREE_TYPE (op2);
3415 code2 = TREE_CODE (type2);
3416
3417 /* C90 does not permit non-lvalue arrays in conditional expressions.
3418 In C99 they will be pointers by now. */
3419 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3420 {
3421 error ("non-lvalue array in conditional expression");
3422 return error_mark_node;
3423 }
3424
3425 /* Quickly detect the usual case where op1 and op2 have the same type
3426 after promotion. */
3427 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3428 {
3429 if (type1 == type2)
3430 result_type = type1;
3431 else
3432 result_type = TYPE_MAIN_VARIANT (type1);
3433 }
3434 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3435 || code1 == COMPLEX_TYPE)
3436 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3437 || code2 == COMPLEX_TYPE))
3438 {
3439 result_type = c_common_type (type1, type2);
3440
3441 /* If -Wsign-compare, warn here if type1 and type2 have
3442 different signedness. We'll promote the signed to unsigned
3443 and later code won't know it used to be different.
3444 Do this check on the original types, so that explicit casts
3445 will be considered, but default promotions won't. */
3446 if (warn_sign_compare && !skip_evaluation)
3447 {
3448 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3449 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3450
3451 if (unsigned_op1 ^ unsigned_op2)
3452 {
3453 bool ovf;
3454
3455 /* Do not warn if the result type is signed, since the
3456 signed type will only be chosen if it can represent
3457 all the values of the unsigned type. */
3458 if (!TYPE_UNSIGNED (result_type))
3459 /* OK */;
3460 /* Do not warn if the signed quantity is an unsuffixed
3461 integer literal (or some static constant expression
3462 involving such literals) and it is non-negative. */
3463 else if ((unsigned_op2
3464 && tree_expr_nonnegative_warnv_p (op1, &ovf))
3465 || (unsigned_op1
3466 && tree_expr_nonnegative_warnv_p (op2, &ovf)))
3467 /* OK */;
3468 else
3469 warning (OPT_Wsign_compare, "signed and unsigned type in conditional expression");
3470 }
3471 }
3472 }
3473 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3474 {
3475 if (code1 != VOID_TYPE || code2 != VOID_TYPE)
3476 pedwarn (input_location, OPT_pedantic,
3477 "ISO C forbids conditional expr with only one void side");
3478 result_type = void_type_node;
3479 }
3480 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3481 {
3482 if (comp_target_types (type1, type2))
3483 result_type = common_pointer_type (type1, type2);
3484 else if (null_pointer_constant_p (orig_op1))
3485 result_type = qualify_type (type2, type1);
3486 else if (null_pointer_constant_p (orig_op2))
3487 result_type = qualify_type (type1, type2);
3488 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3489 {
3490 if (TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3491 pedwarn (input_location, OPT_pedantic,
3492 "ISO C forbids conditional expr between "
3493 "%<void *%> and function pointer");
3494 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3495 TREE_TYPE (type2)));
3496 }
3497 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3498 {
3499 if (TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3500 pedwarn (input_location, OPT_pedantic,
3501 "ISO C forbids conditional expr between "
3502 "%<void *%> and function pointer");
3503 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3504 TREE_TYPE (type1)));
3505 }
3506 else
3507 {
3508 pedwarn (input_location, 0,
3509 "pointer type mismatch in conditional expression");
3510 result_type = build_pointer_type (void_type_node);
3511 }
3512 }
3513 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3514 {
3515 if (!null_pointer_constant_p (orig_op2))
3516 pedwarn (input_location, 0,
3517 "pointer/integer type mismatch in conditional expression");
3518 else
3519 {
3520 op2 = null_pointer_node;
3521 }
3522 result_type = type1;
3523 }
3524 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3525 {
3526 if (!null_pointer_constant_p (orig_op1))
3527 pedwarn (input_location, 0,
3528 "pointer/integer type mismatch in conditional expression");
3529 else
3530 {
3531 op1 = null_pointer_node;
3532 }
3533 result_type = type2;
3534 }
3535
3536 if (!result_type)
3537 {
3538 if (flag_cond_mismatch)
3539 result_type = void_type_node;
3540 else
3541 {
3542 error ("type mismatch in conditional expression");
3543 return error_mark_node;
3544 }
3545 }
3546
3547 /* Merge const and volatile flags of the incoming types. */
3548 result_type
3549 = build_type_variant (result_type,
3550 TREE_READONLY (op1) || TREE_READONLY (op2),
3551 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3552
3553 if (result_type != TREE_TYPE (op1))
3554 op1 = convert_and_check (result_type, op1);
3555 if (result_type != TREE_TYPE (op2))
3556 op2 = convert_and_check (result_type, op2);
3557
3558 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3559 }
3560 \f
3561 /* Return a compound expression that performs two expressions and
3562 returns the value of the second of them. */
3563
3564 tree
3565 build_compound_expr (tree expr1, tree expr2)
3566 {
3567 if (!TREE_SIDE_EFFECTS (expr1))
3568 {
3569 /* The left-hand operand of a comma expression is like an expression
3570 statement: with -Wunused, we should warn if it doesn't have
3571 any side-effects, unless it was explicitly cast to (void). */
3572 if (warn_unused_value)
3573 {
3574 if (VOID_TYPE_P (TREE_TYPE (expr1))
3575 && CONVERT_EXPR_P (expr1))
3576 ; /* (void) a, b */
3577 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3578 && TREE_CODE (expr1) == COMPOUND_EXPR
3579 && CONVERT_EXPR_P (TREE_OPERAND (expr1, 1)))
3580 ; /* (void) a, (void) b, c */
3581 else
3582 warning (OPT_Wunused_value,
3583 "left-hand operand of comma expression has no effect");
3584 }
3585 }
3586
3587 /* With -Wunused, we should also warn if the left-hand operand does have
3588 side-effects, but computes a value which is not used. For example, in
3589 `foo() + bar(), baz()' the result of the `+' operator is not used,
3590 so we should issue a warning. */
3591 else if (warn_unused_value)
3592 warn_if_unused_value (expr1, input_location);
3593
3594 if (expr2 == error_mark_node)
3595 return error_mark_node;
3596
3597 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3598 }
3599
3600 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3601
3602 tree
3603 build_c_cast (tree type, tree expr)
3604 {
3605 tree value = expr;
3606
3607 if (type == error_mark_node || expr == error_mark_node)
3608 return error_mark_node;
3609
3610 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3611 only in <protocol> qualifications. But when constructing cast expressions,
3612 the protocols do matter and must be kept around. */
3613 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3614 return build1 (NOP_EXPR, type, expr);
3615
3616 type = TYPE_MAIN_VARIANT (type);
3617
3618 if (TREE_CODE (type) == ARRAY_TYPE)
3619 {
3620 error ("cast specifies array type");
3621 return error_mark_node;
3622 }
3623
3624 if (TREE_CODE (type) == FUNCTION_TYPE)
3625 {
3626 error ("cast specifies function type");
3627 return error_mark_node;
3628 }
3629
3630 if (!VOID_TYPE_P (type))
3631 {
3632 value = require_complete_type (value);
3633 if (value == error_mark_node)
3634 return error_mark_node;
3635 }
3636
3637 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3638 {
3639 if (TREE_CODE (type) == RECORD_TYPE
3640 || TREE_CODE (type) == UNION_TYPE)
3641 pedwarn (input_location, OPT_pedantic,
3642 "ISO C forbids casting nonscalar to the same type");
3643 }
3644 else if (TREE_CODE (type) == UNION_TYPE)
3645 {
3646 tree field;
3647
3648 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3649 if (TREE_TYPE (field) != error_mark_node
3650 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3651 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3652 break;
3653
3654 if (field)
3655 {
3656 tree t;
3657
3658 pedwarn (input_location, OPT_pedantic,
3659 "ISO C forbids casts to union type");
3660 t = digest_init (type,
3661 build_constructor_single (type, field, value),
3662 true, 0);
3663 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3664 return t;
3665 }
3666 error ("cast to union type from type not present in union");
3667 return error_mark_node;
3668 }
3669 else
3670 {
3671 tree otype, ovalue;
3672
3673 if (type == void_type_node)
3674 return build1 (CONVERT_EXPR, type, value);
3675
3676 otype = TREE_TYPE (value);
3677
3678 /* Optionally warn about potentially worrisome casts. */
3679
3680 if (warn_cast_qual
3681 && TREE_CODE (type) == POINTER_TYPE
3682 && TREE_CODE (otype) == POINTER_TYPE)
3683 {
3684 tree in_type = type;
3685 tree in_otype = otype;
3686 int added = 0;
3687 int discarded = 0;
3688
3689 /* Check that the qualifiers on IN_TYPE are a superset of
3690 the qualifiers of IN_OTYPE. The outermost level of
3691 POINTER_TYPE nodes is uninteresting and we stop as soon
3692 as we hit a non-POINTER_TYPE node on either type. */
3693 do
3694 {
3695 in_otype = TREE_TYPE (in_otype);
3696 in_type = TREE_TYPE (in_type);
3697
3698 /* GNU C allows cv-qualified function types. 'const'
3699 means the function is very pure, 'volatile' means it
3700 can't return. We need to warn when such qualifiers
3701 are added, not when they're taken away. */
3702 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3703 && TREE_CODE (in_type) == FUNCTION_TYPE)
3704 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3705 else
3706 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3707 }
3708 while (TREE_CODE (in_type) == POINTER_TYPE
3709 && TREE_CODE (in_otype) == POINTER_TYPE);
3710
3711 if (added)
3712 warning (OPT_Wcast_qual, "cast adds new qualifiers to function type");
3713
3714 if (discarded)
3715 /* There are qualifiers present in IN_OTYPE that are not
3716 present in IN_TYPE. */
3717 warning (OPT_Wcast_qual, "cast discards qualifiers from pointer target type");
3718 }
3719
3720 /* Warn about possible alignment problems. */
3721 if (STRICT_ALIGNMENT
3722 && TREE_CODE (type) == POINTER_TYPE
3723 && TREE_CODE (otype) == POINTER_TYPE
3724 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3725 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3726 /* Don't warn about opaque types, where the actual alignment
3727 restriction is unknown. */
3728 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3729 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3730 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3731 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3732 warning (OPT_Wcast_align,
3733 "cast increases required alignment of target type");
3734
3735 if (TREE_CODE (type) == INTEGER_TYPE
3736 && TREE_CODE (otype) == POINTER_TYPE
3737 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3738 /* Unlike conversion of integers to pointers, where the
3739 warning is disabled for converting constants because
3740 of cases such as SIG_*, warn about converting constant
3741 pointers to integers. In some cases it may cause unwanted
3742 sign extension, and a warning is appropriate. */
3743 warning (OPT_Wpointer_to_int_cast,
3744 "cast from pointer to integer of different size");
3745
3746 if (TREE_CODE (value) == CALL_EXPR
3747 && TREE_CODE (type) != TREE_CODE (otype))
3748 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3749 "to non-matching type %qT", otype, type);
3750
3751 if (TREE_CODE (type) == POINTER_TYPE
3752 && TREE_CODE (otype) == INTEGER_TYPE
3753 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3754 /* Don't warn about converting any constant. */
3755 && !TREE_CONSTANT (value))
3756 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3757 "of different size");
3758
3759 if (warn_strict_aliasing <= 2)
3760 strict_aliasing_warning (otype, type, expr);
3761
3762 /* If pedantic, warn for conversions between function and object
3763 pointer types, except for converting a null pointer constant
3764 to function pointer type. */
3765 if (pedantic
3766 && TREE_CODE (type) == POINTER_TYPE
3767 && TREE_CODE (otype) == POINTER_TYPE
3768 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3769 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3770 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
3771 "conversion of function pointer to object pointer type");
3772
3773 if (pedantic
3774 && TREE_CODE (type) == POINTER_TYPE
3775 && TREE_CODE (otype) == POINTER_TYPE
3776 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3777 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3778 && !null_pointer_constant_p (value))
3779 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
3780 "conversion of object pointer to function pointer type");
3781
3782 ovalue = value;
3783 value = convert (type, value);
3784
3785 /* Ignore any integer overflow caused by the cast. */
3786 if (TREE_CODE (value) == INTEGER_CST)
3787 {
3788 if (CONSTANT_CLASS_P (ovalue) && TREE_OVERFLOW (ovalue))
3789 {
3790 if (!TREE_OVERFLOW (value))
3791 {
3792 /* Avoid clobbering a shared constant. */
3793 value = copy_node (value);
3794 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3795 }
3796 }
3797 else if (TREE_OVERFLOW (value))
3798 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3799 value = build_int_cst_wide (TREE_TYPE (value),
3800 TREE_INT_CST_LOW (value),
3801 TREE_INT_CST_HIGH (value));
3802 }
3803 }
3804
3805 /* Don't let a cast be an lvalue. */
3806 if (value == expr)
3807 value = non_lvalue (value);
3808
3809 return value;
3810 }
3811
3812 /* Interpret a cast of expression EXPR to type TYPE. */
3813 tree
3814 c_cast_expr (struct c_type_name *type_name, tree expr)
3815 {
3816 tree type;
3817 int saved_wsp = warn_strict_prototypes;
3818
3819 /* This avoids warnings about unprototyped casts on
3820 integers. E.g. "#define SIG_DFL (void(*)())0". */
3821 if (TREE_CODE (expr) == INTEGER_CST)
3822 warn_strict_prototypes = 0;
3823 type = groktypename (type_name);
3824 warn_strict_prototypes = saved_wsp;
3825
3826 return build_c_cast (type, expr);
3827 }
3828 \f
3829 /* Build an assignment expression of lvalue LHS from value RHS.
3830 MODIFYCODE is the code for a binary operator that we use
3831 to combine the old value of LHS with RHS to get the new value.
3832 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3833
3834 tree
3835 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3836 {
3837 tree result;
3838 tree newrhs;
3839 tree lhstype = TREE_TYPE (lhs);
3840 tree olhstype = lhstype;
3841
3842 /* Types that aren't fully specified cannot be used in assignments. */
3843 lhs = require_complete_type (lhs);
3844
3845 /* Avoid duplicate error messages from operands that had errors. */
3846 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3847 return error_mark_node;
3848
3849 if (!lvalue_or_else (lhs, lv_assign))
3850 return error_mark_node;
3851
3852 STRIP_TYPE_NOPS (rhs);
3853
3854 newrhs = rhs;
3855
3856 /* If a binary op has been requested, combine the old LHS value with the RHS
3857 producing the value we should actually store into the LHS. */
3858
3859 if (modifycode != NOP_EXPR)
3860 {
3861 lhs = stabilize_reference (lhs);
3862 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3863 }
3864
3865 /* Give an error for storing in something that is 'const'. */
3866
3867 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3868 || ((TREE_CODE (lhstype) == RECORD_TYPE
3869 || TREE_CODE (lhstype) == UNION_TYPE)
3870 && C_TYPE_FIELDS_READONLY (lhstype)))
3871 {
3872 readonly_error (lhs, lv_assign);
3873 return error_mark_node;
3874 }
3875
3876 /* If storing into a structure or union member,
3877 it has probably been given type `int'.
3878 Compute the type that would go with
3879 the actual amount of storage the member occupies. */
3880
3881 if (TREE_CODE (lhs) == COMPONENT_REF
3882 && (TREE_CODE (lhstype) == INTEGER_TYPE
3883 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3884 || TREE_CODE (lhstype) == REAL_TYPE
3885 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3886 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3887
3888 /* If storing in a field that is in actuality a short or narrower than one,
3889 we must store in the field in its actual type. */
3890
3891 if (lhstype != TREE_TYPE (lhs))
3892 {
3893 lhs = copy_node (lhs);
3894 TREE_TYPE (lhs) = lhstype;
3895 }
3896
3897 /* Convert new value to destination type. */
3898
3899 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3900 NULL_TREE, NULL_TREE, 0);
3901 if (TREE_CODE (newrhs) == ERROR_MARK)
3902 return error_mark_node;
3903
3904 /* Emit ObjC write barrier, if necessary. */
3905 if (c_dialect_objc () && flag_objc_gc)
3906 {
3907 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3908 if (result)
3909 return result;
3910 }
3911
3912 /* Scan operands. */
3913
3914 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3915 TREE_SIDE_EFFECTS (result) = 1;
3916
3917 /* If we got the LHS in a different type for storing in,
3918 convert the result back to the nominal type of LHS
3919 so that the value we return always has the same type
3920 as the LHS argument. */
3921
3922 if (olhstype == TREE_TYPE (result))
3923 return result;
3924 return convert_for_assignment (olhstype, result, ic_assign,
3925 NULL_TREE, NULL_TREE, 0);
3926 }
3927 \f
3928 /* Convert value RHS to type TYPE as preparation for an assignment
3929 to an lvalue of type TYPE.
3930 The real work of conversion is done by `convert'.
3931 The purpose of this function is to generate error messages
3932 for assignments that are not allowed in C.
3933 ERRTYPE says whether it is argument passing, assignment,
3934 initialization or return.
3935
3936 FUNCTION is a tree for the function being called.
3937 PARMNUM is the number of the argument, for printing in error messages. */
3938
3939 static tree
3940 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3941 tree fundecl, tree function, int parmnum)
3942 {
3943 enum tree_code codel = TREE_CODE (type);
3944 tree rhstype;
3945 enum tree_code coder;
3946 tree rname = NULL_TREE;
3947 bool objc_ok = false;
3948
3949 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3950 {
3951 tree selector;
3952 /* Change pointer to function to the function itself for
3953 diagnostics. */
3954 if (TREE_CODE (function) == ADDR_EXPR
3955 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3956 function = TREE_OPERAND (function, 0);
3957
3958 /* Handle an ObjC selector specially for diagnostics. */
3959 selector = objc_message_selector ();
3960 rname = function;
3961 if (selector && parmnum > 2)
3962 {
3963 rname = selector;
3964 parmnum -= 2;
3965 }
3966 }
3967
3968 /* This macro is used to emit diagnostics to ensure that all format
3969 strings are complete sentences, visible to gettext and checked at
3970 compile time. */
3971 #define WARN_FOR_ASSIGNMENT(LOCATION, OPT, AR, AS, IN, RE) \
3972 do { \
3973 switch (errtype) \
3974 { \
3975 case ic_argpass: \
3976 if (pedwarn (LOCATION, OPT, AR, parmnum, rname)) \
3977 inform (fundecl ? DECL_SOURCE_LOCATION (fundecl) : LOCATION, \
3978 "expected %qT but argument is of type %qT", \
3979 type, rhstype); \
3980 break; \
3981 case ic_argpass_nonproto: \
3982 warning (OPT, AR, parmnum, rname); \
3983 break; \
3984 case ic_assign: \
3985 pedwarn (LOCATION, OPT, AS); \
3986 break; \
3987 case ic_init: \
3988 pedwarn (LOCATION, OPT, IN); \
3989 break; \
3990 case ic_return: \
3991 pedwarn (LOCATION, OPT, RE); \
3992 break; \
3993 default: \
3994 gcc_unreachable (); \
3995 } \
3996 } while (0)
3997
3998 STRIP_TYPE_NOPS (rhs);
3999
4000 if (optimize && TREE_CODE (rhs) == VAR_DECL
4001 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
4002 rhs = decl_constant_value_for_broken_optimization (rhs);
4003
4004 rhstype = TREE_TYPE (rhs);
4005 coder = TREE_CODE (rhstype);
4006
4007 if (coder == ERROR_MARK)
4008 return error_mark_node;
4009
4010 if (c_dialect_objc ())
4011 {
4012 int parmno;
4013
4014 switch (errtype)
4015 {
4016 case ic_return:
4017 parmno = 0;
4018 break;
4019
4020 case ic_assign:
4021 parmno = -1;
4022 break;
4023
4024 case ic_init:
4025 parmno = -2;
4026 break;
4027
4028 default:
4029 parmno = parmnum;
4030 break;
4031 }
4032
4033 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
4034 }
4035
4036 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
4037 return rhs;
4038
4039 if (coder == VOID_TYPE)
4040 {
4041 /* Except for passing an argument to an unprototyped function,
4042 this is a constraint violation. When passing an argument to
4043 an unprototyped function, it is compile-time undefined;
4044 making it a constraint in that case was rejected in
4045 DR#252. */
4046 error ("void value not ignored as it ought to be");
4047 return error_mark_node;
4048 }
4049 rhs = require_complete_type (rhs);
4050 if (rhs == error_mark_node)
4051 return error_mark_node;
4052 /* A type converts to a reference to it.
4053 This code doesn't fully support references, it's just for the
4054 special case of va_start and va_copy. */
4055 if (codel == REFERENCE_TYPE
4056 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
4057 {
4058 if (!lvalue_p (rhs))
4059 {
4060 error ("cannot pass rvalue to reference parameter");
4061 return error_mark_node;
4062 }
4063 if (!c_mark_addressable (rhs))
4064 return error_mark_node;
4065 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
4066
4067 /* We already know that these two types are compatible, but they
4068 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4069 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4070 likely to be va_list, a typedef to __builtin_va_list, which
4071 is different enough that it will cause problems later. */
4072 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
4073 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
4074
4075 rhs = build1 (NOP_EXPR, type, rhs);
4076 return rhs;
4077 }
4078 /* Some types can interconvert without explicit casts. */
4079 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
4080 && vector_types_convertible_p (type, TREE_TYPE (rhs), true))
4081 return convert (type, rhs);
4082 /* Arithmetic types all interconvert, and enum is treated like int. */
4083 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
4084 || codel == FIXED_POINT_TYPE
4085 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
4086 || codel == BOOLEAN_TYPE)
4087 && (coder == INTEGER_TYPE || coder == REAL_TYPE
4088 || coder == FIXED_POINT_TYPE
4089 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
4090 || coder == BOOLEAN_TYPE))
4091 return convert_and_check (type, rhs);
4092
4093 /* Aggregates in different TUs might need conversion. */
4094 if ((codel == RECORD_TYPE || codel == UNION_TYPE)
4095 && codel == coder
4096 && comptypes (type, rhstype))
4097 return convert_and_check (type, rhs);
4098
4099 /* Conversion to a transparent union from its member types.
4100 This applies only to function arguments. */
4101 if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
4102 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
4103 {
4104 tree memb, marginal_memb = NULL_TREE;
4105
4106 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
4107 {
4108 tree memb_type = TREE_TYPE (memb);
4109
4110 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
4111 TYPE_MAIN_VARIANT (rhstype)))
4112 break;
4113
4114 if (TREE_CODE (memb_type) != POINTER_TYPE)
4115 continue;
4116
4117 if (coder == POINTER_TYPE)
4118 {
4119 tree ttl = TREE_TYPE (memb_type);
4120 tree ttr = TREE_TYPE (rhstype);
4121
4122 /* Any non-function converts to a [const][volatile] void *
4123 and vice versa; otherwise, targets must be the same.
4124 Meanwhile, the lhs target must have all the qualifiers of
4125 the rhs. */
4126 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4127 || comp_target_types (memb_type, rhstype))
4128 {
4129 /* If this type won't generate any warnings, use it. */
4130 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
4131 || ((TREE_CODE (ttr) == FUNCTION_TYPE
4132 && TREE_CODE (ttl) == FUNCTION_TYPE)
4133 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4134 == TYPE_QUALS (ttr))
4135 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4136 == TYPE_QUALS (ttl))))
4137 break;
4138
4139 /* Keep looking for a better type, but remember this one. */
4140 if (!marginal_memb)
4141 marginal_memb = memb;
4142 }
4143 }
4144
4145 /* Can convert integer zero to any pointer type. */
4146 if (null_pointer_constant_p (rhs))
4147 {
4148 rhs = null_pointer_node;
4149 break;
4150 }
4151 }
4152
4153 if (memb || marginal_memb)
4154 {
4155 if (!memb)
4156 {
4157 /* We have only a marginally acceptable member type;
4158 it needs a warning. */
4159 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
4160 tree ttr = TREE_TYPE (rhstype);
4161
4162 /* Const and volatile mean something different for function
4163 types, so the usual warnings are not appropriate. */
4164 if (TREE_CODE (ttr) == FUNCTION_TYPE
4165 && TREE_CODE (ttl) == FUNCTION_TYPE)
4166 {
4167 /* Because const and volatile on functions are
4168 restrictions that say the function will not do
4169 certain things, it is okay to use a const or volatile
4170 function where an ordinary one is wanted, but not
4171 vice-versa. */
4172 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4173 WARN_FOR_ASSIGNMENT (input_location, 0,
4174 G_("passing argument %d of %qE "
4175 "makes qualified function "
4176 "pointer from unqualified"),
4177 G_("assignment makes qualified "
4178 "function pointer from "
4179 "unqualified"),
4180 G_("initialization makes qualified "
4181 "function pointer from "
4182 "unqualified"),
4183 G_("return makes qualified function "
4184 "pointer from unqualified"));
4185 }
4186 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4187 WARN_FOR_ASSIGNMENT (input_location, 0,
4188 G_("passing argument %d of %qE discards "
4189 "qualifiers from pointer target type"),
4190 G_("assignment discards qualifiers "
4191 "from pointer target type"),
4192 G_("initialization discards qualifiers "
4193 "from pointer target type"),
4194 G_("return discards qualifiers from "
4195 "pointer target type"));
4196
4197 memb = marginal_memb;
4198 }
4199
4200 if (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl))
4201 pedwarn (input_location, OPT_pedantic,
4202 "ISO C prohibits argument conversion to union type");
4203
4204 rhs = fold_convert (TREE_TYPE (memb), rhs);
4205 return build_constructor_single (type, memb, rhs);
4206 }
4207 }
4208
4209 /* Conversions among pointers */
4210 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4211 && (coder == codel))
4212 {
4213 tree ttl = TREE_TYPE (type);
4214 tree ttr = TREE_TYPE (rhstype);
4215 tree mvl = ttl;
4216 tree mvr = ttr;
4217 bool is_opaque_pointer;
4218 int target_cmp = 0; /* Cache comp_target_types () result. */
4219
4220 if (TREE_CODE (mvl) != ARRAY_TYPE)
4221 mvl = TYPE_MAIN_VARIANT (mvl);
4222 if (TREE_CODE (mvr) != ARRAY_TYPE)
4223 mvr = TYPE_MAIN_VARIANT (mvr);
4224 /* Opaque pointers are treated like void pointers. */
4225 is_opaque_pointer = vector_targets_convertible_p (ttl, ttr);
4226
4227 /* C++ does not allow the implicit conversion void* -> T*. However,
4228 for the purpose of reducing the number of false positives, we
4229 tolerate the special case of
4230
4231 int *p = NULL;
4232
4233 where NULL is typically defined in C to be '(void *) 0'. */
4234 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4235 warning (OPT_Wc___compat, "request for implicit conversion from "
4236 "%qT to %qT not permitted in C++", rhstype, type);
4237
4238 /* Check if the right-hand side has a format attribute but the
4239 left-hand side doesn't. */
4240 if (warn_missing_format_attribute
4241 && check_missing_format_attribute (type, rhstype))
4242 {
4243 switch (errtype)
4244 {
4245 case ic_argpass:
4246 case ic_argpass_nonproto:
4247 warning (OPT_Wmissing_format_attribute,
4248 "argument %d of %qE might be "
4249 "a candidate for a format attribute",
4250 parmnum, rname);
4251 break;
4252 case ic_assign:
4253 warning (OPT_Wmissing_format_attribute,
4254 "assignment left-hand side might be "
4255 "a candidate for a format attribute");
4256 break;
4257 case ic_init:
4258 warning (OPT_Wmissing_format_attribute,
4259 "initialization left-hand side might be "
4260 "a candidate for a format attribute");
4261 break;
4262 case ic_return:
4263 warning (OPT_Wmissing_format_attribute,
4264 "return type might be "
4265 "a candidate for a format attribute");
4266 break;
4267 default:
4268 gcc_unreachable ();
4269 }
4270 }
4271
4272 /* Any non-function converts to a [const][volatile] void *
4273 and vice versa; otherwise, targets must be the same.
4274 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4275 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4276 || (target_cmp = comp_target_types (type, rhstype))
4277 || is_opaque_pointer
4278 || (c_common_unsigned_type (mvl)
4279 == c_common_unsigned_type (mvr)))
4280 {
4281 if (pedantic
4282 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4283 ||
4284 (VOID_TYPE_P (ttr)
4285 && !null_pointer_constant_p (rhs)
4286 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4287 WARN_FOR_ASSIGNMENT (input_location, OPT_pedantic,
4288 G_("ISO C forbids passing argument %d of "
4289 "%qE between function pointer "
4290 "and %<void *%>"),
4291 G_("ISO C forbids assignment between "
4292 "function pointer and %<void *%>"),
4293 G_("ISO C forbids initialization between "
4294 "function pointer and %<void *%>"),
4295 G_("ISO C forbids return between function "
4296 "pointer and %<void *%>"));
4297 /* Const and volatile mean something different for function types,
4298 so the usual warnings are not appropriate. */
4299 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4300 && TREE_CODE (ttl) != FUNCTION_TYPE)
4301 {
4302 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4303 {
4304 /* Types differing only by the presence of the 'volatile'
4305 qualifier are acceptable if the 'volatile' has been added
4306 in by the Objective-C EH machinery. */
4307 if (!objc_type_quals_match (ttl, ttr))
4308 WARN_FOR_ASSIGNMENT (input_location, 0,
4309 G_("passing argument %d of %qE discards "
4310 "qualifiers from pointer target type"),
4311 G_("assignment discards qualifiers "
4312 "from pointer target type"),
4313 G_("initialization discards qualifiers "
4314 "from pointer target type"),
4315 G_("return discards qualifiers from "
4316 "pointer target type"));
4317 }
4318 /* If this is not a case of ignoring a mismatch in signedness,
4319 no warning. */
4320 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4321 || target_cmp)
4322 ;
4323 /* If there is a mismatch, do warn. */
4324 else if (warn_pointer_sign)
4325 WARN_FOR_ASSIGNMENT (input_location, OPT_Wpointer_sign,
4326 G_("pointer targets in passing argument "
4327 "%d of %qE differ in signedness"),
4328 G_("pointer targets in assignment "
4329 "differ in signedness"),
4330 G_("pointer targets in initialization "
4331 "differ in signedness"),
4332 G_("pointer targets in return differ "
4333 "in signedness"));
4334 }
4335 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4336 && TREE_CODE (ttr) == FUNCTION_TYPE)
4337 {
4338 /* Because const and volatile on functions are restrictions
4339 that say the function will not do certain things,
4340 it is okay to use a const or volatile function
4341 where an ordinary one is wanted, but not vice-versa. */
4342 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4343 WARN_FOR_ASSIGNMENT (input_location, 0,
4344 G_("passing argument %d of %qE makes "
4345 "qualified function pointer "
4346 "from unqualified"),
4347 G_("assignment makes qualified function "
4348 "pointer from unqualified"),
4349 G_("initialization makes qualified "
4350 "function pointer from unqualified"),
4351 G_("return makes qualified function "
4352 "pointer from unqualified"));
4353 }
4354 }
4355 else
4356 /* Avoid warning about the volatile ObjC EH puts on decls. */
4357 if (!objc_ok)
4358 WARN_FOR_ASSIGNMENT (input_location, 0,
4359 G_("passing argument %d of %qE from "
4360 "incompatible pointer type"),
4361 G_("assignment from incompatible pointer type"),
4362 G_("initialization from incompatible "
4363 "pointer type"),
4364 G_("return from incompatible pointer type"));
4365
4366 return convert (type, rhs);
4367 }
4368 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4369 {
4370 /* ??? This should not be an error when inlining calls to
4371 unprototyped functions. */
4372 error ("invalid use of non-lvalue array");
4373 return error_mark_node;
4374 }
4375 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4376 {
4377 /* An explicit constant 0 can convert to a pointer,
4378 or one that results from arithmetic, even including
4379 a cast to integer type. */
4380 if (!null_pointer_constant_p (rhs))
4381 WARN_FOR_ASSIGNMENT (input_location, 0,
4382 G_("passing argument %d of %qE makes "
4383 "pointer from integer without a cast"),
4384 G_("assignment makes pointer from integer "
4385 "without a cast"),
4386 G_("initialization makes pointer from "
4387 "integer without a cast"),
4388 G_("return makes pointer from integer "
4389 "without a cast"));
4390
4391 return convert (type, rhs);
4392 }
4393 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4394 {
4395 WARN_FOR_ASSIGNMENT (input_location, 0,
4396 G_("passing argument %d of %qE makes integer "
4397 "from pointer without a cast"),
4398 G_("assignment makes integer from pointer "
4399 "without a cast"),
4400 G_("initialization makes integer from pointer "
4401 "without a cast"),
4402 G_("return makes integer from pointer "
4403 "without a cast"));
4404 return convert (type, rhs);
4405 }
4406 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4407 return convert (type, rhs);
4408
4409 switch (errtype)
4410 {
4411 case ic_argpass:
4412 case ic_argpass_nonproto:
4413 /* ??? This should not be an error when inlining calls to
4414 unprototyped functions. */
4415 error ("incompatible type for argument %d of %qE", parmnum, rname);
4416 break;
4417 case ic_assign:
4418 error ("incompatible types in assignment");
4419 break;
4420 case ic_init:
4421 error ("incompatible types in initialization");
4422 break;
4423 case ic_return:
4424 error ("incompatible types in return");
4425 break;
4426 default:
4427 gcc_unreachable ();
4428 }
4429
4430 return error_mark_node;
4431 }
4432 \f
4433 /* If VALUE is a compound expr all of whose expressions are constant, then
4434 return its value. Otherwise, return error_mark_node.
4435
4436 This is for handling COMPOUND_EXPRs as initializer elements
4437 which is allowed with a warning when -pedantic is specified. */
4438
4439 static tree
4440 valid_compound_expr_initializer (tree value, tree endtype)
4441 {
4442 if (TREE_CODE (value) == COMPOUND_EXPR)
4443 {
4444 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4445 == error_mark_node)
4446 return error_mark_node;
4447 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4448 endtype);
4449 }
4450 else if (!initializer_constant_valid_p (value, endtype))
4451 return error_mark_node;
4452 else
4453 return value;
4454 }
4455 \f
4456 /* Perform appropriate conversions on the initial value of a variable,
4457 store it in the declaration DECL,
4458 and print any error messages that are appropriate.
4459 If the init is invalid, store an ERROR_MARK. */
4460
4461 void
4462 store_init_value (tree decl, tree init)
4463 {
4464 tree value, type;
4465
4466 /* If variable's type was invalidly declared, just ignore it. */
4467
4468 type = TREE_TYPE (decl);
4469 if (TREE_CODE (type) == ERROR_MARK)
4470 return;
4471
4472 /* Digest the specified initializer into an expression. */
4473
4474 value = digest_init (type, init, true, TREE_STATIC (decl));
4475
4476 /* Store the expression if valid; else report error. */
4477
4478 if (!in_system_header
4479 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4480 warning (OPT_Wtraditional, "traditional C rejects automatic "
4481 "aggregate initialization");
4482
4483 DECL_INITIAL (decl) = value;
4484
4485 /* ANSI wants warnings about out-of-range constant initializers. */
4486 STRIP_TYPE_NOPS (value);
4487 if (TREE_STATIC (decl))
4488 constant_expression_warning (value);
4489
4490 /* Check if we need to set array size from compound literal size. */
4491 if (TREE_CODE (type) == ARRAY_TYPE
4492 && TYPE_DOMAIN (type) == 0
4493 && value != error_mark_node)
4494 {
4495 tree inside_init = init;
4496
4497 STRIP_TYPE_NOPS (inside_init);
4498 inside_init = fold (inside_init);
4499
4500 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4501 {
4502 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4503
4504 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4505 {
4506 /* For int foo[] = (int [3]){1}; we need to set array size
4507 now since later on array initializer will be just the
4508 brace enclosed list of the compound literal. */
4509 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4510 TREE_TYPE (decl) = type;
4511 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4512 layout_type (type);
4513 layout_decl (cldecl, 0);
4514 }
4515 }
4516 }
4517 }
4518 \f
4519 /* Methods for storing and printing names for error messages. */
4520
4521 /* Implement a spelling stack that allows components of a name to be pushed
4522 and popped. Each element on the stack is this structure. */
4523
4524 struct spelling
4525 {
4526 int kind;
4527 union
4528 {
4529 unsigned HOST_WIDE_INT i;
4530 const char *s;
4531 } u;
4532 };
4533
4534 #define SPELLING_STRING 1
4535 #define SPELLING_MEMBER 2
4536 #define SPELLING_BOUNDS 3
4537
4538 static struct spelling *spelling; /* Next stack element (unused). */
4539 static struct spelling *spelling_base; /* Spelling stack base. */
4540 static int spelling_size; /* Size of the spelling stack. */
4541
4542 /* Macros to save and restore the spelling stack around push_... functions.
4543 Alternative to SAVE_SPELLING_STACK. */
4544
4545 #define SPELLING_DEPTH() (spelling - spelling_base)
4546 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4547
4548 /* Push an element on the spelling stack with type KIND and assign VALUE
4549 to MEMBER. */
4550
4551 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4552 { \
4553 int depth = SPELLING_DEPTH (); \
4554 \
4555 if (depth >= spelling_size) \
4556 { \
4557 spelling_size += 10; \
4558 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4559 spelling_size); \
4560 RESTORE_SPELLING_DEPTH (depth); \
4561 } \
4562 \
4563 spelling->kind = (KIND); \
4564 spelling->MEMBER = (VALUE); \
4565 spelling++; \
4566 }
4567
4568 /* Push STRING on the stack. Printed literally. */
4569
4570 static void
4571 push_string (const char *string)
4572 {
4573 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4574 }
4575
4576 /* Push a member name on the stack. Printed as '.' STRING. */
4577
4578 static void
4579 push_member_name (tree decl)
4580 {
4581 const char *const string
4582 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4583 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4584 }
4585
4586 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4587
4588 static void
4589 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4590 {
4591 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4592 }
4593
4594 /* Compute the maximum size in bytes of the printed spelling. */
4595
4596 static int
4597 spelling_length (void)
4598 {
4599 int size = 0;
4600 struct spelling *p;
4601
4602 for (p = spelling_base; p < spelling; p++)
4603 {
4604 if (p->kind == SPELLING_BOUNDS)
4605 size += 25;
4606 else
4607 size += strlen (p->u.s) + 1;
4608 }
4609
4610 return size;
4611 }
4612
4613 /* Print the spelling to BUFFER and return it. */
4614
4615 static char *
4616 print_spelling (char *buffer)
4617 {
4618 char *d = buffer;
4619 struct spelling *p;
4620
4621 for (p = spelling_base; p < spelling; p++)
4622 if (p->kind == SPELLING_BOUNDS)
4623 {
4624 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4625 d += strlen (d);
4626 }
4627 else
4628 {
4629 const char *s;
4630 if (p->kind == SPELLING_MEMBER)
4631 *d++ = '.';
4632 for (s = p->u.s; (*d = *s++); d++)
4633 ;
4634 }
4635 *d++ = '\0';
4636 return buffer;
4637 }
4638
4639 /* Issue an error message for a bad initializer component.
4640 MSGID identifies the message.
4641 The component name is taken from the spelling stack. */
4642
4643 void
4644 error_init (const char *msgid)
4645 {
4646 char *ofwhat;
4647
4648 error ("%s", _(msgid));
4649 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4650 if (*ofwhat)
4651 error ("(near initialization for %qs)", ofwhat);
4652 }
4653
4654 /* Issue a pedantic warning for a bad initializer component. OPT is
4655 the option OPT_* (from options.h) controlling this warning or 0 if
4656 it is unconditionally given. MSGID identifies the message. The
4657 component name is taken from the spelling stack. */
4658
4659 void
4660 pedwarn_init (location_t location, int opt, const char *msgid)
4661 {
4662 char *ofwhat;
4663
4664 pedwarn (location, opt, "%s", _(msgid));
4665 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4666 if (*ofwhat)
4667 pedwarn (location, opt, "(near initialization for %qs)", ofwhat);
4668 }
4669
4670 /* Issue a warning for a bad initializer component.
4671
4672 OPT is the OPT_W* value corresponding to the warning option that
4673 controls this warning. MSGID identifies the message. The
4674 component name is taken from the spelling stack. */
4675
4676 static void
4677 warning_init (int opt, const char *msgid)
4678 {
4679 char *ofwhat;
4680
4681 warning (opt, "%s", _(msgid));
4682 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4683 if (*ofwhat)
4684 warning (opt, "(near initialization for %qs)", ofwhat);
4685 }
4686 \f
4687 /* If TYPE is an array type and EXPR is a parenthesized string
4688 constant, warn if pedantic that EXPR is being used to initialize an
4689 object of type TYPE. */
4690
4691 void
4692 maybe_warn_string_init (tree type, struct c_expr expr)
4693 {
4694 if (pedantic
4695 && TREE_CODE (type) == ARRAY_TYPE
4696 && TREE_CODE (expr.value) == STRING_CST
4697 && expr.original_code != STRING_CST)
4698 pedwarn_init (input_location, OPT_pedantic,
4699 "array initialized from parenthesized string constant");
4700 }
4701
4702 /* Digest the parser output INIT as an initializer for type TYPE.
4703 Return a C expression of type TYPE to represent the initial value.
4704
4705 If INIT is a string constant, STRICT_STRING is true if it is
4706 unparenthesized or we should not warn here for it being parenthesized.
4707 For other types of INIT, STRICT_STRING is not used.
4708
4709 REQUIRE_CONSTANT requests an error if non-constant initializers or
4710 elements are seen. */
4711
4712 static tree
4713 digest_init (tree type, tree init, bool strict_string, int require_constant)
4714 {
4715 enum tree_code code = TREE_CODE (type);
4716 tree inside_init = init;
4717
4718 if (type == error_mark_node
4719 || !init
4720 || init == error_mark_node
4721 || TREE_TYPE (init) == error_mark_node)
4722 return error_mark_node;
4723
4724 STRIP_TYPE_NOPS (inside_init);
4725
4726 inside_init = fold (inside_init);
4727
4728 /* Initialization of an array of chars from a string constant
4729 optionally enclosed in braces. */
4730
4731 if (code == ARRAY_TYPE && inside_init
4732 && TREE_CODE (inside_init) == STRING_CST)
4733 {
4734 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4735 /* Note that an array could be both an array of character type
4736 and an array of wchar_t if wchar_t is signed char or unsigned
4737 char. */
4738 bool char_array = (typ1 == char_type_node
4739 || typ1 == signed_char_type_node
4740 || typ1 == unsigned_char_type_node);
4741 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4742 bool char16_array = !!comptypes (typ1, char16_type_node);
4743 bool char32_array = !!comptypes (typ1, char32_type_node);
4744
4745 if (char_array || wchar_array || char16_array || char32_array)
4746 {
4747 struct c_expr expr;
4748 tree typ2 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)));
4749 expr.value = inside_init;
4750 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4751 maybe_warn_string_init (type, expr);
4752
4753 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4754 TYPE_MAIN_VARIANT (type)))
4755 return inside_init;
4756
4757 if (char_array)
4758 {
4759 if (typ2 != char_type_node)
4760 {
4761 error_init ("char-array initialized from wide string");
4762 return error_mark_node;
4763 }
4764 }
4765 else
4766 {
4767 if (typ2 == char_type_node)
4768 {
4769 error_init ("wide character array initialized from non-wide "
4770 "string");
4771 return error_mark_node;
4772 }
4773 else if (!comptypes(typ1, typ2))
4774 {
4775 error_init ("wide character array initialized from "
4776 "incompatible wide string");
4777 return error_mark_node;
4778 }
4779 }
4780
4781 TREE_TYPE (inside_init) = type;
4782 if (TYPE_DOMAIN (type) != 0
4783 && TYPE_SIZE (type) != 0
4784 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4785 /* Subtract the size of a single (possibly wide) character
4786 because it's ok to ignore the terminating null char
4787 that is counted in the length of the constant. */
4788 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4789 TREE_STRING_LENGTH (inside_init)
4790 - (TYPE_PRECISION (typ1)
4791 / BITS_PER_UNIT)))
4792 pedwarn_init (input_location, 0,
4793 "initializer-string for array of chars is too long");
4794
4795 return inside_init;
4796 }
4797 else if (INTEGRAL_TYPE_P (typ1))
4798 {
4799 error_init ("array of inappropriate type initialized "
4800 "from string constant");
4801 return error_mark_node;
4802 }
4803 }
4804
4805 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4806 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4807 below and handle as a constructor. */
4808 if (code == VECTOR_TYPE
4809 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4810 && vector_types_convertible_p (TREE_TYPE (inside_init), type, true)
4811 && TREE_CONSTANT (inside_init))
4812 {
4813 if (TREE_CODE (inside_init) == VECTOR_CST
4814 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4815 TYPE_MAIN_VARIANT (type)))
4816 return inside_init;
4817
4818 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4819 {
4820 unsigned HOST_WIDE_INT ix;
4821 tree value;
4822 bool constant_p = true;
4823
4824 /* Iterate through elements and check if all constructor
4825 elements are *_CSTs. */
4826 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4827 if (!CONSTANT_CLASS_P (value))
4828 {
4829 constant_p = false;
4830 break;
4831 }
4832
4833 if (constant_p)
4834 return build_vector_from_ctor (type,
4835 CONSTRUCTOR_ELTS (inside_init));
4836 }
4837 }
4838
4839 if (warn_sequence_point)
4840 verify_sequence_points (inside_init);
4841
4842 /* Any type can be initialized
4843 from an expression of the same type, optionally with braces. */
4844
4845 if (inside_init && TREE_TYPE (inside_init) != 0
4846 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4847 TYPE_MAIN_VARIANT (type))
4848 || (code == ARRAY_TYPE
4849 && comptypes (TREE_TYPE (inside_init), type))
4850 || (code == VECTOR_TYPE
4851 && comptypes (TREE_TYPE (inside_init), type))
4852 || (code == POINTER_TYPE
4853 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4854 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4855 TREE_TYPE (type)))))
4856 {
4857 if (code == POINTER_TYPE)
4858 {
4859 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4860 {
4861 if (TREE_CODE (inside_init) == STRING_CST
4862 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4863 inside_init = array_to_pointer_conversion (inside_init);
4864 else
4865 {
4866 error_init ("invalid use of non-lvalue array");
4867 return error_mark_node;
4868 }
4869 }
4870 }
4871
4872 if (code == VECTOR_TYPE)
4873 /* Although the types are compatible, we may require a
4874 conversion. */
4875 inside_init = convert (type, inside_init);
4876
4877 if (require_constant
4878 && (code == VECTOR_TYPE || !flag_isoc99)
4879 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4880 {
4881 /* As an extension, allow initializing objects with static storage
4882 duration with compound literals (which are then treated just as
4883 the brace enclosed list they contain). Also allow this for
4884 vectors, as we can only assign them with compound literals. */
4885 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4886 inside_init = DECL_INITIAL (decl);
4887 }
4888
4889 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4890 && TREE_CODE (inside_init) != CONSTRUCTOR)
4891 {
4892 error_init ("array initialized from non-constant array expression");
4893 return error_mark_node;
4894 }
4895
4896 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4897 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4898
4899 /* Compound expressions can only occur here if -pedantic or
4900 -pedantic-errors is specified. In the later case, we always want
4901 an error. In the former case, we simply want a warning. */
4902 if (require_constant && pedantic
4903 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4904 {
4905 inside_init
4906 = valid_compound_expr_initializer (inside_init,
4907 TREE_TYPE (inside_init));
4908 if (inside_init == error_mark_node)
4909 error_init ("initializer element is not constant");
4910 else
4911 pedwarn_init (input_location, OPT_pedantic,
4912 "initializer element is not constant");
4913 if (flag_pedantic_errors)
4914 inside_init = error_mark_node;
4915 }
4916 else if (require_constant
4917 && !initializer_constant_valid_p (inside_init,
4918 TREE_TYPE (inside_init)))
4919 {
4920 error_init ("initializer element is not constant");
4921 inside_init = error_mark_node;
4922 }
4923
4924 /* Added to enable additional -Wmissing-format-attribute warnings. */
4925 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4926 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4927 NULL_TREE, 0);
4928 return inside_init;
4929 }
4930
4931 /* Handle scalar types, including conversions. */
4932
4933 if (code == INTEGER_TYPE || code == REAL_TYPE || code == FIXED_POINT_TYPE
4934 || code == POINTER_TYPE || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE
4935 || code == COMPLEX_TYPE || code == VECTOR_TYPE)
4936 {
4937 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4938 && (TREE_CODE (init) == STRING_CST
4939 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4940 init = array_to_pointer_conversion (init);
4941 inside_init
4942 = convert_for_assignment (type, init, ic_init,
4943 NULL_TREE, NULL_TREE, 0);
4944
4945 /* Check to see if we have already given an error message. */
4946 if (inside_init == error_mark_node)
4947 ;
4948 else if (require_constant && !TREE_CONSTANT (inside_init))
4949 {
4950 error_init ("initializer element is not constant");
4951 inside_init = error_mark_node;
4952 }
4953 else if (require_constant
4954 && !initializer_constant_valid_p (inside_init,
4955 TREE_TYPE (inside_init)))
4956 {
4957 error_init ("initializer element is not computable at load time");
4958 inside_init = error_mark_node;
4959 }
4960
4961 return inside_init;
4962 }
4963
4964 /* Come here only for records and arrays. */
4965
4966 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4967 {
4968 error_init ("variable-sized object may not be initialized");
4969 return error_mark_node;
4970 }
4971
4972 error_init ("invalid initializer");
4973 return error_mark_node;
4974 }
4975 \f
4976 /* Handle initializers that use braces. */
4977
4978 /* Type of object we are accumulating a constructor for.
4979 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4980 static tree constructor_type;
4981
4982 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4983 left to fill. */
4984 static tree constructor_fields;
4985
4986 /* For an ARRAY_TYPE, this is the specified index
4987 at which to store the next element we get. */
4988 static tree constructor_index;
4989
4990 /* For an ARRAY_TYPE, this is the maximum index. */
4991 static tree constructor_max_index;
4992
4993 /* For a RECORD_TYPE, this is the first field not yet written out. */
4994 static tree constructor_unfilled_fields;
4995
4996 /* For an ARRAY_TYPE, this is the index of the first element
4997 not yet written out. */
4998 static tree constructor_unfilled_index;
4999
5000 /* In a RECORD_TYPE, the byte index of the next consecutive field.
5001 This is so we can generate gaps between fields, when appropriate. */
5002 static tree constructor_bit_index;
5003
5004 /* If we are saving up the elements rather than allocating them,
5005 this is the list of elements so far (in reverse order,
5006 most recent first). */
5007 static VEC(constructor_elt,gc) *constructor_elements;
5008
5009 /* 1 if constructor should be incrementally stored into a constructor chain,
5010 0 if all the elements should be kept in AVL tree. */
5011 static int constructor_incremental;
5012
5013 /* 1 if so far this constructor's elements are all compile-time constants. */
5014 static int constructor_constant;
5015
5016 /* 1 if so far this constructor's elements are all valid address constants. */
5017 static int constructor_simple;
5018
5019 /* 1 if this constructor is erroneous so far. */
5020 static int constructor_erroneous;
5021
5022 /* Structure for managing pending initializer elements, organized as an
5023 AVL tree. */
5024
5025 struct init_node
5026 {
5027 struct init_node *left, *right;
5028 struct init_node *parent;
5029 int balance;
5030 tree purpose;
5031 tree value;
5032 };
5033
5034 /* Tree of pending elements at this constructor level.
5035 These are elements encountered out of order
5036 which belong at places we haven't reached yet in actually
5037 writing the output.
5038 Will never hold tree nodes across GC runs. */
5039 static struct init_node *constructor_pending_elts;
5040
5041 /* The SPELLING_DEPTH of this constructor. */
5042 static int constructor_depth;
5043
5044 /* DECL node for which an initializer is being read.
5045 0 means we are reading a constructor expression
5046 such as (struct foo) {...}. */
5047 static tree constructor_decl;
5048
5049 /* Nonzero if this is an initializer for a top-level decl. */
5050 static int constructor_top_level;
5051
5052 /* Nonzero if there were any member designators in this initializer. */
5053 static int constructor_designated;
5054
5055 /* Nesting depth of designator list. */
5056 static int designator_depth;
5057
5058 /* Nonzero if there were diagnosed errors in this designator list. */
5059 static int designator_erroneous;
5060
5061 \f
5062 /* This stack has a level for each implicit or explicit level of
5063 structuring in the initializer, including the outermost one. It
5064 saves the values of most of the variables above. */
5065
5066 struct constructor_range_stack;
5067
5068 struct constructor_stack
5069 {
5070 struct constructor_stack *next;
5071 tree type;
5072 tree fields;
5073 tree index;
5074 tree max_index;
5075 tree unfilled_index;
5076 tree unfilled_fields;
5077 tree bit_index;
5078 VEC(constructor_elt,gc) *elements;
5079 struct init_node *pending_elts;
5080 int offset;
5081 int depth;
5082 /* If value nonzero, this value should replace the entire
5083 constructor at this level. */
5084 struct c_expr replacement_value;
5085 struct constructor_range_stack *range_stack;
5086 char constant;
5087 char simple;
5088 char implicit;
5089 char erroneous;
5090 char outer;
5091 char incremental;
5092 char designated;
5093 };
5094
5095 static struct constructor_stack *constructor_stack;
5096
5097 /* This stack represents designators from some range designator up to
5098 the last designator in the list. */
5099
5100 struct constructor_range_stack
5101 {
5102 struct constructor_range_stack *next, *prev;
5103 struct constructor_stack *stack;
5104 tree range_start;
5105 tree index;
5106 tree range_end;
5107 tree fields;
5108 };
5109
5110 static struct constructor_range_stack *constructor_range_stack;
5111
5112 /* This stack records separate initializers that are nested.
5113 Nested initializers can't happen in ANSI C, but GNU C allows them
5114 in cases like { ... (struct foo) { ... } ... }. */
5115
5116 struct initializer_stack
5117 {
5118 struct initializer_stack *next;
5119 tree decl;
5120 struct constructor_stack *constructor_stack;
5121 struct constructor_range_stack *constructor_range_stack;
5122 VEC(constructor_elt,gc) *elements;
5123 struct spelling *spelling;
5124 struct spelling *spelling_base;
5125 int spelling_size;
5126 char top_level;
5127 char require_constant_value;
5128 char require_constant_elements;
5129 };
5130
5131 static struct initializer_stack *initializer_stack;
5132 \f
5133 /* Prepare to parse and output the initializer for variable DECL. */
5134
5135 void
5136 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
5137 {
5138 const char *locus;
5139 struct initializer_stack *p = XNEW (struct initializer_stack);
5140
5141 p->decl = constructor_decl;
5142 p->require_constant_value = require_constant_value;
5143 p->require_constant_elements = require_constant_elements;
5144 p->constructor_stack = constructor_stack;
5145 p->constructor_range_stack = constructor_range_stack;
5146 p->elements = constructor_elements;
5147 p->spelling = spelling;
5148 p->spelling_base = spelling_base;
5149 p->spelling_size = spelling_size;
5150 p->top_level = constructor_top_level;
5151 p->next = initializer_stack;
5152 initializer_stack = p;
5153
5154 constructor_decl = decl;
5155 constructor_designated = 0;
5156 constructor_top_level = top_level;
5157
5158 if (decl != 0 && decl != error_mark_node)
5159 {
5160 require_constant_value = TREE_STATIC (decl);
5161 require_constant_elements
5162 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5163 /* For a scalar, you can always use any value to initialize,
5164 even within braces. */
5165 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5166 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5167 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5168 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5169 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5170 }
5171 else
5172 {
5173 require_constant_value = 0;
5174 require_constant_elements = 0;
5175 locus = "(anonymous)";
5176 }
5177
5178 constructor_stack = 0;
5179 constructor_range_stack = 0;
5180
5181 missing_braces_mentioned = 0;
5182
5183 spelling_base = 0;
5184 spelling_size = 0;
5185 RESTORE_SPELLING_DEPTH (0);
5186
5187 if (locus)
5188 push_string (locus);
5189 }
5190
5191 void
5192 finish_init (void)
5193 {
5194 struct initializer_stack *p = initializer_stack;
5195
5196 /* Free the whole constructor stack of this initializer. */
5197 while (constructor_stack)
5198 {
5199 struct constructor_stack *q = constructor_stack;
5200 constructor_stack = q->next;
5201 free (q);
5202 }
5203
5204 gcc_assert (!constructor_range_stack);
5205
5206 /* Pop back to the data of the outer initializer (if any). */
5207 free (spelling_base);
5208
5209 constructor_decl = p->decl;
5210 require_constant_value = p->require_constant_value;
5211 require_constant_elements = p->require_constant_elements;
5212 constructor_stack = p->constructor_stack;
5213 constructor_range_stack = p->constructor_range_stack;
5214 constructor_elements = p->elements;
5215 spelling = p->spelling;
5216 spelling_base = p->spelling_base;
5217 spelling_size = p->spelling_size;
5218 constructor_top_level = p->top_level;
5219 initializer_stack = p->next;
5220 free (p);
5221 }
5222 \f
5223 /* Call here when we see the initializer is surrounded by braces.
5224 This is instead of a call to push_init_level;
5225 it is matched by a call to pop_init_level.
5226
5227 TYPE is the type to initialize, for a constructor expression.
5228 For an initializer for a decl, TYPE is zero. */
5229
5230 void
5231 really_start_incremental_init (tree type)
5232 {
5233 struct constructor_stack *p = XNEW (struct constructor_stack);
5234
5235 if (type == 0)
5236 type = TREE_TYPE (constructor_decl);
5237
5238 if (targetm.vector_opaque_p (type))
5239 error ("opaque vector types cannot be initialized");
5240
5241 p->type = constructor_type;
5242 p->fields = constructor_fields;
5243 p->index = constructor_index;
5244 p->max_index = constructor_max_index;
5245 p->unfilled_index = constructor_unfilled_index;
5246 p->unfilled_fields = constructor_unfilled_fields;
5247 p->bit_index = constructor_bit_index;
5248 p->elements = constructor_elements;
5249 p->constant = constructor_constant;
5250 p->simple = constructor_simple;
5251 p->erroneous = constructor_erroneous;
5252 p->pending_elts = constructor_pending_elts;
5253 p->depth = constructor_depth;
5254 p->replacement_value.value = 0;
5255 p->replacement_value.original_code = ERROR_MARK;
5256 p->implicit = 0;
5257 p->range_stack = 0;
5258 p->outer = 0;
5259 p->incremental = constructor_incremental;
5260 p->designated = constructor_designated;
5261 p->next = 0;
5262 constructor_stack = p;
5263
5264 constructor_constant = 1;
5265 constructor_simple = 1;
5266 constructor_depth = SPELLING_DEPTH ();
5267 constructor_elements = 0;
5268 constructor_pending_elts = 0;
5269 constructor_type = type;
5270 constructor_incremental = 1;
5271 constructor_designated = 0;
5272 designator_depth = 0;
5273 designator_erroneous = 0;
5274
5275 if (TREE_CODE (constructor_type) == RECORD_TYPE
5276 || TREE_CODE (constructor_type) == UNION_TYPE)
5277 {
5278 constructor_fields = TYPE_FIELDS (constructor_type);
5279 /* Skip any nameless bit fields at the beginning. */
5280 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5281 && DECL_NAME (constructor_fields) == 0)
5282 constructor_fields = TREE_CHAIN (constructor_fields);
5283
5284 constructor_unfilled_fields = constructor_fields;
5285 constructor_bit_index = bitsize_zero_node;
5286 }
5287 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5288 {
5289 if (TYPE_DOMAIN (constructor_type))
5290 {
5291 constructor_max_index
5292 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5293
5294 /* Detect non-empty initializations of zero-length arrays. */
5295 if (constructor_max_index == NULL_TREE
5296 && TYPE_SIZE (constructor_type))
5297 constructor_max_index = build_int_cst (NULL_TREE, -1);
5298
5299 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5300 to initialize VLAs will cause a proper error; avoid tree
5301 checking errors as well by setting a safe value. */
5302 if (constructor_max_index
5303 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5304 constructor_max_index = build_int_cst (NULL_TREE, -1);
5305
5306 constructor_index
5307 = convert (bitsizetype,
5308 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5309 }
5310 else
5311 {
5312 constructor_index = bitsize_zero_node;
5313 constructor_max_index = NULL_TREE;
5314 }
5315
5316 constructor_unfilled_index = constructor_index;
5317 }
5318 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5319 {
5320 /* Vectors are like simple fixed-size arrays. */
5321 constructor_max_index =
5322 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5323 constructor_index = bitsize_zero_node;
5324 constructor_unfilled_index = constructor_index;
5325 }
5326 else
5327 {
5328 /* Handle the case of int x = {5}; */
5329 constructor_fields = constructor_type;
5330 constructor_unfilled_fields = constructor_type;
5331 }
5332 }
5333 \f
5334 /* Push down into a subobject, for initialization.
5335 If this is for an explicit set of braces, IMPLICIT is 0.
5336 If it is because the next element belongs at a lower level,
5337 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5338
5339 void
5340 push_init_level (int implicit)
5341 {
5342 struct constructor_stack *p;
5343 tree value = NULL_TREE;
5344
5345 /* If we've exhausted any levels that didn't have braces,
5346 pop them now. If implicit == 1, this will have been done in
5347 process_init_element; do not repeat it here because in the case
5348 of excess initializers for an empty aggregate this leads to an
5349 infinite cycle of popping a level and immediately recreating
5350 it. */
5351 if (implicit != 1)
5352 {
5353 while (constructor_stack->implicit)
5354 {
5355 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5356 || TREE_CODE (constructor_type) == UNION_TYPE)
5357 && constructor_fields == 0)
5358 process_init_element (pop_init_level (1));
5359 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5360 && constructor_max_index
5361 && tree_int_cst_lt (constructor_max_index,
5362 constructor_index))
5363 process_init_element (pop_init_level (1));
5364 else
5365 break;
5366 }
5367 }
5368
5369 /* Unless this is an explicit brace, we need to preserve previous
5370 content if any. */
5371 if (implicit)
5372 {
5373 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5374 || TREE_CODE (constructor_type) == UNION_TYPE)
5375 && constructor_fields)
5376 value = find_init_member (constructor_fields);
5377 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5378 value = find_init_member (constructor_index);
5379 }
5380
5381 p = XNEW (struct constructor_stack);
5382 p->type = constructor_type;
5383 p->fields = constructor_fields;
5384 p->index = constructor_index;
5385 p->max_index = constructor_max_index;
5386 p->unfilled_index = constructor_unfilled_index;
5387 p->unfilled_fields = constructor_unfilled_fields;
5388 p->bit_index = constructor_bit_index;
5389 p->elements = constructor_elements;
5390 p->constant = constructor_constant;
5391 p->simple = constructor_simple;
5392 p->erroneous = constructor_erroneous;
5393 p->pending_elts = constructor_pending_elts;
5394 p->depth = constructor_depth;
5395 p->replacement_value.value = 0;
5396 p->replacement_value.original_code = ERROR_MARK;
5397 p->implicit = implicit;
5398 p->outer = 0;
5399 p->incremental = constructor_incremental;
5400 p->designated = constructor_designated;
5401 p->next = constructor_stack;
5402 p->range_stack = 0;
5403 constructor_stack = p;
5404
5405 constructor_constant = 1;
5406 constructor_simple = 1;
5407 constructor_depth = SPELLING_DEPTH ();
5408 constructor_elements = 0;
5409 constructor_incremental = 1;
5410 constructor_designated = 0;
5411 constructor_pending_elts = 0;
5412 if (!implicit)
5413 {
5414 p->range_stack = constructor_range_stack;
5415 constructor_range_stack = 0;
5416 designator_depth = 0;
5417 designator_erroneous = 0;
5418 }
5419
5420 /* Don't die if an entire brace-pair level is superfluous
5421 in the containing level. */
5422 if (constructor_type == 0)
5423 ;
5424 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5425 || TREE_CODE (constructor_type) == UNION_TYPE)
5426 {
5427 /* Don't die if there are extra init elts at the end. */
5428 if (constructor_fields == 0)
5429 constructor_type = 0;
5430 else
5431 {
5432 constructor_type = TREE_TYPE (constructor_fields);
5433 push_member_name (constructor_fields);
5434 constructor_depth++;
5435 }
5436 }
5437 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5438 {
5439 constructor_type = TREE_TYPE (constructor_type);
5440 push_array_bounds (tree_low_cst (constructor_index, 1));
5441 constructor_depth++;
5442 }
5443
5444 if (constructor_type == 0)
5445 {
5446 error_init ("extra brace group at end of initializer");
5447 constructor_fields = 0;
5448 constructor_unfilled_fields = 0;
5449 return;
5450 }
5451
5452 if (value && TREE_CODE (value) == CONSTRUCTOR)
5453 {
5454 constructor_constant = TREE_CONSTANT (value);
5455 constructor_simple = TREE_STATIC (value);
5456 constructor_elements = CONSTRUCTOR_ELTS (value);
5457 if (!VEC_empty (constructor_elt, constructor_elements)
5458 && (TREE_CODE (constructor_type) == RECORD_TYPE
5459 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5460 set_nonincremental_init ();
5461 }
5462
5463 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5464 {
5465 missing_braces_mentioned = 1;
5466 warning_init (OPT_Wmissing_braces, "missing braces around initializer");
5467 }
5468
5469 if (TREE_CODE (constructor_type) == RECORD_TYPE
5470 || TREE_CODE (constructor_type) == UNION_TYPE)
5471 {
5472 constructor_fields = TYPE_FIELDS (constructor_type);
5473 /* Skip any nameless bit fields at the beginning. */
5474 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5475 && DECL_NAME (constructor_fields) == 0)
5476 constructor_fields = TREE_CHAIN (constructor_fields);
5477
5478 constructor_unfilled_fields = constructor_fields;
5479 constructor_bit_index = bitsize_zero_node;
5480 }
5481 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5482 {
5483 /* Vectors are like simple fixed-size arrays. */
5484 constructor_max_index =
5485 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5486 constructor_index = convert (bitsizetype, integer_zero_node);
5487 constructor_unfilled_index = constructor_index;
5488 }
5489 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5490 {
5491 if (TYPE_DOMAIN (constructor_type))
5492 {
5493 constructor_max_index
5494 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5495
5496 /* Detect non-empty initializations of zero-length arrays. */
5497 if (constructor_max_index == NULL_TREE
5498 && TYPE_SIZE (constructor_type))
5499 constructor_max_index = build_int_cst (NULL_TREE, -1);
5500
5501 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5502 to initialize VLAs will cause a proper error; avoid tree
5503 checking errors as well by setting a safe value. */
5504 if (constructor_max_index
5505 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5506 constructor_max_index = build_int_cst (NULL_TREE, -1);
5507
5508 constructor_index
5509 = convert (bitsizetype,
5510 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5511 }
5512 else
5513 constructor_index = bitsize_zero_node;
5514
5515 constructor_unfilled_index = constructor_index;
5516 if (value && TREE_CODE (value) == STRING_CST)
5517 {
5518 /* We need to split the char/wchar array into individual
5519 characters, so that we don't have to special case it
5520 everywhere. */
5521 set_nonincremental_init_from_string (value);
5522 }
5523 }
5524 else
5525 {
5526 if (constructor_type != error_mark_node)
5527 warning_init (0, "braces around scalar initializer");
5528 constructor_fields = constructor_type;
5529 constructor_unfilled_fields = constructor_type;
5530 }
5531 }
5532
5533 /* At the end of an implicit or explicit brace level,
5534 finish up that level of constructor. If a single expression
5535 with redundant braces initialized that level, return the
5536 c_expr structure for that expression. Otherwise, the original_code
5537 element is set to ERROR_MARK.
5538 If we were outputting the elements as they are read, return 0 as the value
5539 from inner levels (process_init_element ignores that),
5540 but return error_mark_node as the value from the outermost level
5541 (that's what we want to put in DECL_INITIAL).
5542 Otherwise, return a CONSTRUCTOR expression as the value. */
5543
5544 struct c_expr
5545 pop_init_level (int implicit)
5546 {
5547 struct constructor_stack *p;
5548 struct c_expr ret;
5549 ret.value = 0;
5550 ret.original_code = ERROR_MARK;
5551
5552 if (implicit == 0)
5553 {
5554 /* When we come to an explicit close brace,
5555 pop any inner levels that didn't have explicit braces. */
5556 while (constructor_stack->implicit)
5557 process_init_element (pop_init_level (1));
5558
5559 gcc_assert (!constructor_range_stack);
5560 }
5561
5562 /* Now output all pending elements. */
5563 constructor_incremental = 1;
5564 output_pending_init_elements (1);
5565
5566 p = constructor_stack;
5567
5568 /* Error for initializing a flexible array member, or a zero-length
5569 array member in an inappropriate context. */
5570 if (constructor_type && constructor_fields
5571 && TREE_CODE (constructor_type) == ARRAY_TYPE
5572 && TYPE_DOMAIN (constructor_type)
5573 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5574 {
5575 /* Silently discard empty initializations. The parser will
5576 already have pedwarned for empty brackets. */
5577 if (integer_zerop (constructor_unfilled_index))
5578 constructor_type = NULL_TREE;
5579 else
5580 {
5581 gcc_assert (!TYPE_SIZE (constructor_type));
5582
5583 if (constructor_depth > 2)
5584 error_init ("initialization of flexible array member in a nested context");
5585 else
5586 pedwarn_init (input_location, OPT_pedantic,
5587 "initialization of a flexible array member");
5588
5589 /* We have already issued an error message for the existence
5590 of a flexible array member not at the end of the structure.
5591 Discard the initializer so that we do not die later. */
5592 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5593 constructor_type = NULL_TREE;
5594 }
5595 }
5596
5597 /* Warn when some struct elements are implicitly initialized to zero. */
5598 if (warn_missing_field_initializers
5599 && constructor_type
5600 && TREE_CODE (constructor_type) == RECORD_TYPE
5601 && constructor_unfilled_fields)
5602 {
5603 /* Do not warn for flexible array members or zero-length arrays. */
5604 while (constructor_unfilled_fields
5605 && (!DECL_SIZE (constructor_unfilled_fields)
5606 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5607 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5608
5609 /* Do not warn if this level of the initializer uses member
5610 designators; it is likely to be deliberate. */
5611 if (constructor_unfilled_fields && !constructor_designated)
5612 {
5613 push_member_name (constructor_unfilled_fields);
5614 warning_init (OPT_Wmissing_field_initializers,
5615 "missing initializer");
5616 RESTORE_SPELLING_DEPTH (constructor_depth);
5617 }
5618 }
5619
5620 /* Pad out the end of the structure. */
5621 if (p->replacement_value.value)
5622 /* If this closes a superfluous brace pair,
5623 just pass out the element between them. */
5624 ret = p->replacement_value;
5625 else if (constructor_type == 0)
5626 ;
5627 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5628 && TREE_CODE (constructor_type) != UNION_TYPE
5629 && TREE_CODE (constructor_type) != ARRAY_TYPE
5630 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5631 {
5632 /* A nonincremental scalar initializer--just return
5633 the element, after verifying there is just one. */
5634 if (VEC_empty (constructor_elt,constructor_elements))
5635 {
5636 if (!constructor_erroneous)
5637 error_init ("empty scalar initializer");
5638 ret.value = error_mark_node;
5639 }
5640 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5641 {
5642 error_init ("extra elements in scalar initializer");
5643 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5644 }
5645 else
5646 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5647 }
5648 else
5649 {
5650 if (constructor_erroneous)
5651 ret.value = error_mark_node;
5652 else
5653 {
5654 ret.value = build_constructor (constructor_type,
5655 constructor_elements);
5656 if (constructor_constant)
5657 TREE_CONSTANT (ret.value) = 1;
5658 if (constructor_constant && constructor_simple)
5659 TREE_STATIC (ret.value) = 1;
5660 }
5661 }
5662
5663 constructor_type = p->type;
5664 constructor_fields = p->fields;
5665 constructor_index = p->index;
5666 constructor_max_index = p->max_index;
5667 constructor_unfilled_index = p->unfilled_index;
5668 constructor_unfilled_fields = p->unfilled_fields;
5669 constructor_bit_index = p->bit_index;
5670 constructor_elements = p->elements;
5671 constructor_constant = p->constant;
5672 constructor_simple = p->simple;
5673 constructor_erroneous = p->erroneous;
5674 constructor_incremental = p->incremental;
5675 constructor_designated = p->designated;
5676 constructor_pending_elts = p->pending_elts;
5677 constructor_depth = p->depth;
5678 if (!p->implicit)
5679 constructor_range_stack = p->range_stack;
5680 RESTORE_SPELLING_DEPTH (constructor_depth);
5681
5682 constructor_stack = p->next;
5683 free (p);
5684
5685 if (ret.value == 0 && constructor_stack == 0)
5686 ret.value = error_mark_node;
5687 return ret;
5688 }
5689
5690 /* Common handling for both array range and field name designators.
5691 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5692
5693 static int
5694 set_designator (int array)
5695 {
5696 tree subtype;
5697 enum tree_code subcode;
5698
5699 /* Don't die if an entire brace-pair level is superfluous
5700 in the containing level. */
5701 if (constructor_type == 0)
5702 return 1;
5703
5704 /* If there were errors in this designator list already, bail out
5705 silently. */
5706 if (designator_erroneous)
5707 return 1;
5708
5709 if (!designator_depth)
5710 {
5711 gcc_assert (!constructor_range_stack);
5712
5713 /* Designator list starts at the level of closest explicit
5714 braces. */
5715 while (constructor_stack->implicit)
5716 process_init_element (pop_init_level (1));
5717 constructor_designated = 1;
5718 return 0;
5719 }
5720
5721 switch (TREE_CODE (constructor_type))
5722 {
5723 case RECORD_TYPE:
5724 case UNION_TYPE:
5725 subtype = TREE_TYPE (constructor_fields);
5726 if (subtype != error_mark_node)
5727 subtype = TYPE_MAIN_VARIANT (subtype);
5728 break;
5729 case ARRAY_TYPE:
5730 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5731 break;
5732 default:
5733 gcc_unreachable ();
5734 }
5735
5736 subcode = TREE_CODE (subtype);
5737 if (array && subcode != ARRAY_TYPE)
5738 {
5739 error_init ("array index in non-array initializer");
5740 return 1;
5741 }
5742 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5743 {
5744 error_init ("field name not in record or union initializer");
5745 return 1;
5746 }
5747
5748 constructor_designated = 1;
5749 push_init_level (2);
5750 return 0;
5751 }
5752
5753 /* If there are range designators in designator list, push a new designator
5754 to constructor_range_stack. RANGE_END is end of such stack range or
5755 NULL_TREE if there is no range designator at this level. */
5756
5757 static void
5758 push_range_stack (tree range_end)
5759 {
5760 struct constructor_range_stack *p;
5761
5762 p = GGC_NEW (struct constructor_range_stack);
5763 p->prev = constructor_range_stack;
5764 p->next = 0;
5765 p->fields = constructor_fields;
5766 p->range_start = constructor_index;
5767 p->index = constructor_index;
5768 p->stack = constructor_stack;
5769 p->range_end = range_end;
5770 if (constructor_range_stack)
5771 constructor_range_stack->next = p;
5772 constructor_range_stack = p;
5773 }
5774
5775 /* Within an array initializer, specify the next index to be initialized.
5776 FIRST is that index. If LAST is nonzero, then initialize a range
5777 of indices, running from FIRST through LAST. */
5778
5779 void
5780 set_init_index (tree first, tree last)
5781 {
5782 if (set_designator (1))
5783 return;
5784
5785 designator_erroneous = 1;
5786
5787 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5788 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5789 {
5790 error_init ("array index in initializer not of integer type");
5791 return;
5792 }
5793
5794 if (TREE_CODE (first) != INTEGER_CST)
5795 error_init ("nonconstant array index in initializer");
5796 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5797 error_init ("nonconstant array index in initializer");
5798 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5799 error_init ("array index in non-array initializer");
5800 else if (tree_int_cst_sgn (first) == -1)
5801 error_init ("array index in initializer exceeds array bounds");
5802 else if (constructor_max_index
5803 && tree_int_cst_lt (constructor_max_index, first))
5804 error_init ("array index in initializer exceeds array bounds");
5805 else
5806 {
5807 constructor_index = convert (bitsizetype, first);
5808
5809 if (last)
5810 {
5811 if (tree_int_cst_equal (first, last))
5812 last = 0;
5813 else if (tree_int_cst_lt (last, first))
5814 {
5815 error_init ("empty index range in initializer");
5816 last = 0;
5817 }
5818 else
5819 {
5820 last = convert (bitsizetype, last);
5821 if (constructor_max_index != 0
5822 && tree_int_cst_lt (constructor_max_index, last))
5823 {
5824 error_init ("array index range in initializer exceeds array bounds");
5825 last = 0;
5826 }
5827 }
5828 }
5829
5830 designator_depth++;
5831 designator_erroneous = 0;
5832 if (constructor_range_stack || last)
5833 push_range_stack (last);
5834 }
5835 }
5836
5837 /* Within a struct initializer, specify the next field to be initialized. */
5838
5839 void
5840 set_init_label (tree fieldname)
5841 {
5842 tree tail;
5843
5844 if (set_designator (0))
5845 return;
5846
5847 designator_erroneous = 1;
5848
5849 if (TREE_CODE (constructor_type) != RECORD_TYPE
5850 && TREE_CODE (constructor_type) != UNION_TYPE)
5851 {
5852 error_init ("field name not in record or union initializer");
5853 return;
5854 }
5855
5856 for (tail = TYPE_FIELDS (constructor_type); tail;
5857 tail = TREE_CHAIN (tail))
5858 {
5859 if (DECL_NAME (tail) == fieldname)
5860 break;
5861 }
5862
5863 if (tail == 0)
5864 error ("unknown field %qE specified in initializer", fieldname);
5865 else
5866 {
5867 constructor_fields = tail;
5868 designator_depth++;
5869 designator_erroneous = 0;
5870 if (constructor_range_stack)
5871 push_range_stack (NULL_TREE);
5872 }
5873 }
5874 \f
5875 /* Add a new initializer to the tree of pending initializers. PURPOSE
5876 identifies the initializer, either array index or field in a structure.
5877 VALUE is the value of that index or field. */
5878
5879 static void
5880 add_pending_init (tree purpose, tree value)
5881 {
5882 struct init_node *p, **q, *r;
5883
5884 q = &constructor_pending_elts;
5885 p = 0;
5886
5887 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5888 {
5889 while (*q != 0)
5890 {
5891 p = *q;
5892 if (tree_int_cst_lt (purpose, p->purpose))
5893 q = &p->left;
5894 else if (tree_int_cst_lt (p->purpose, purpose))
5895 q = &p->right;
5896 else
5897 {
5898 if (TREE_SIDE_EFFECTS (p->value))
5899 warning_init (0, "initialized field with side-effects overwritten");
5900 else if (warn_override_init)
5901 warning_init (OPT_Woverride_init, "initialized field overwritten");
5902 p->value = value;
5903 return;
5904 }
5905 }
5906 }
5907 else
5908 {
5909 tree bitpos;
5910
5911 bitpos = bit_position (purpose);
5912 while (*q != NULL)
5913 {
5914 p = *q;
5915 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5916 q = &p->left;
5917 else if (p->purpose != purpose)
5918 q = &p->right;
5919 else
5920 {
5921 if (TREE_SIDE_EFFECTS (p->value))
5922 warning_init (0, "initialized field with side-effects overwritten");
5923 else if (warn_override_init)
5924 warning_init (OPT_Woverride_init, "initialized field overwritten");
5925 p->value = value;
5926 return;
5927 }
5928 }
5929 }
5930
5931 r = GGC_NEW (struct init_node);
5932 r->purpose = purpose;
5933 r->value = value;
5934
5935 *q = r;
5936 r->parent = p;
5937 r->left = 0;
5938 r->right = 0;
5939 r->balance = 0;
5940
5941 while (p)
5942 {
5943 struct init_node *s;
5944
5945 if (r == p->left)
5946 {
5947 if (p->balance == 0)
5948 p->balance = -1;
5949 else if (p->balance < 0)
5950 {
5951 if (r->balance < 0)
5952 {
5953 /* L rotation. */
5954 p->left = r->right;
5955 if (p->left)
5956 p->left->parent = p;
5957 r->right = p;
5958
5959 p->balance = 0;
5960 r->balance = 0;
5961
5962 s = p->parent;
5963 p->parent = r;
5964 r->parent = s;
5965 if (s)
5966 {
5967 if (s->left == p)
5968 s->left = r;
5969 else
5970 s->right = r;
5971 }
5972 else
5973 constructor_pending_elts = r;
5974 }
5975 else
5976 {
5977 /* LR rotation. */
5978 struct init_node *t = r->right;
5979
5980 r->right = t->left;
5981 if (r->right)
5982 r->right->parent = r;
5983 t->left = r;
5984
5985 p->left = t->right;
5986 if (p->left)
5987 p->left->parent = p;
5988 t->right = p;
5989
5990 p->balance = t->balance < 0;
5991 r->balance = -(t->balance > 0);
5992 t->balance = 0;
5993
5994 s = p->parent;
5995 p->parent = t;
5996 r->parent = t;
5997 t->parent = s;
5998 if (s)
5999 {
6000 if (s->left == p)
6001 s->left = t;
6002 else
6003 s->right = t;
6004 }
6005 else
6006 constructor_pending_elts = t;
6007 }
6008 break;
6009 }
6010 else
6011 {
6012 /* p->balance == +1; growth of left side balances the node. */
6013 p->balance = 0;
6014 break;
6015 }
6016 }
6017 else /* r == p->right */
6018 {
6019 if (p->balance == 0)
6020 /* Growth propagation from right side. */
6021 p->balance++;
6022 else if (p->balance > 0)
6023 {
6024 if (r->balance > 0)
6025 {
6026 /* R rotation. */
6027 p->right = r->left;
6028 if (p->right)
6029 p->right->parent = p;
6030 r->left = p;
6031
6032 p->balance = 0;
6033 r->balance = 0;
6034
6035 s = p->parent;
6036 p->parent = r;
6037 r->parent = s;
6038 if (s)
6039 {
6040 if (s->left == p)
6041 s->left = r;
6042 else
6043 s->right = r;
6044 }
6045 else
6046 constructor_pending_elts = r;
6047 }
6048 else /* r->balance == -1 */
6049 {
6050 /* RL rotation */
6051 struct init_node *t = r->left;
6052
6053 r->left = t->right;
6054 if (r->left)
6055 r->left->parent = r;
6056 t->right = r;
6057
6058 p->right = t->left;
6059 if (p->right)
6060 p->right->parent = p;
6061 t->left = p;
6062
6063 r->balance = (t->balance < 0);
6064 p->balance = -(t->balance > 0);
6065 t->balance = 0;
6066
6067 s = p->parent;
6068 p->parent = t;
6069 r->parent = t;
6070 t->parent = s;
6071 if (s)
6072 {
6073 if (s->left == p)
6074 s->left = t;
6075 else
6076 s->right = t;
6077 }
6078 else
6079 constructor_pending_elts = t;
6080 }
6081 break;
6082 }
6083 else
6084 {
6085 /* p->balance == -1; growth of right side balances the node. */
6086 p->balance = 0;
6087 break;
6088 }
6089 }
6090
6091 r = p;
6092 p = p->parent;
6093 }
6094 }
6095
6096 /* Build AVL tree from a sorted chain. */
6097
6098 static void
6099 set_nonincremental_init (void)
6100 {
6101 unsigned HOST_WIDE_INT ix;
6102 tree index, value;
6103
6104 if (TREE_CODE (constructor_type) != RECORD_TYPE
6105 && TREE_CODE (constructor_type) != ARRAY_TYPE)
6106 return;
6107
6108 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
6109 add_pending_init (index, value);
6110 constructor_elements = 0;
6111 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6112 {
6113 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
6114 /* Skip any nameless bit fields at the beginning. */
6115 while (constructor_unfilled_fields != 0
6116 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6117 && DECL_NAME (constructor_unfilled_fields) == 0)
6118 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
6119
6120 }
6121 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6122 {
6123 if (TYPE_DOMAIN (constructor_type))
6124 constructor_unfilled_index
6125 = convert (bitsizetype,
6126 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
6127 else
6128 constructor_unfilled_index = bitsize_zero_node;
6129 }
6130 constructor_incremental = 0;
6131 }
6132
6133 /* Build AVL tree from a string constant. */
6134
6135 static void
6136 set_nonincremental_init_from_string (tree str)
6137 {
6138 tree value, purpose, type;
6139 HOST_WIDE_INT val[2];
6140 const char *p, *end;
6141 int byte, wchar_bytes, charwidth, bitpos;
6142
6143 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
6144
6145 wchar_bytes = TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) / BITS_PER_UNIT;
6146 charwidth = TYPE_PRECISION (char_type_node);
6147 type = TREE_TYPE (constructor_type);
6148 p = TREE_STRING_POINTER (str);
6149 end = p + TREE_STRING_LENGTH (str);
6150
6151 for (purpose = bitsize_zero_node;
6152 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6153 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6154 {
6155 if (wchar_bytes == 1)
6156 {
6157 val[1] = (unsigned char) *p++;
6158 val[0] = 0;
6159 }
6160 else
6161 {
6162 val[0] = 0;
6163 val[1] = 0;
6164 for (byte = 0; byte < wchar_bytes; byte++)
6165 {
6166 if (BYTES_BIG_ENDIAN)
6167 bitpos = (wchar_bytes - byte - 1) * charwidth;
6168 else
6169 bitpos = byte * charwidth;
6170 val[bitpos < HOST_BITS_PER_WIDE_INT]
6171 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6172 << (bitpos % HOST_BITS_PER_WIDE_INT);
6173 }
6174 }
6175
6176 if (!TYPE_UNSIGNED (type))
6177 {
6178 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6179 if (bitpos < HOST_BITS_PER_WIDE_INT)
6180 {
6181 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6182 {
6183 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6184 val[0] = -1;
6185 }
6186 }
6187 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6188 {
6189 if (val[1] < 0)
6190 val[0] = -1;
6191 }
6192 else if (val[0] & (((HOST_WIDE_INT) 1)
6193 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6194 val[0] |= ((HOST_WIDE_INT) -1)
6195 << (bitpos - HOST_BITS_PER_WIDE_INT);
6196 }
6197
6198 value = build_int_cst_wide (type, val[1], val[0]);
6199 add_pending_init (purpose, value);
6200 }
6201
6202 constructor_incremental = 0;
6203 }
6204
6205 /* Return value of FIELD in pending initializer or zero if the field was
6206 not initialized yet. */
6207
6208 static tree
6209 find_init_member (tree field)
6210 {
6211 struct init_node *p;
6212
6213 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6214 {
6215 if (constructor_incremental
6216 && tree_int_cst_lt (field, constructor_unfilled_index))
6217 set_nonincremental_init ();
6218
6219 p = constructor_pending_elts;
6220 while (p)
6221 {
6222 if (tree_int_cst_lt (field, p->purpose))
6223 p = p->left;
6224 else if (tree_int_cst_lt (p->purpose, field))
6225 p = p->right;
6226 else
6227 return p->value;
6228 }
6229 }
6230 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6231 {
6232 tree bitpos = bit_position (field);
6233
6234 if (constructor_incremental
6235 && (!constructor_unfilled_fields
6236 || tree_int_cst_lt (bitpos,
6237 bit_position (constructor_unfilled_fields))))
6238 set_nonincremental_init ();
6239
6240 p = constructor_pending_elts;
6241 while (p)
6242 {
6243 if (field == p->purpose)
6244 return p->value;
6245 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6246 p = p->left;
6247 else
6248 p = p->right;
6249 }
6250 }
6251 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6252 {
6253 if (!VEC_empty (constructor_elt, constructor_elements)
6254 && (VEC_last (constructor_elt, constructor_elements)->index
6255 == field))
6256 return VEC_last (constructor_elt, constructor_elements)->value;
6257 }
6258 return 0;
6259 }
6260
6261 /* "Output" the next constructor element.
6262 At top level, really output it to assembler code now.
6263 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6264 TYPE is the data type that the containing data type wants here.
6265 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6266 If VALUE is a string constant, STRICT_STRING is true if it is
6267 unparenthesized or we should not warn here for it being parenthesized.
6268 For other types of VALUE, STRICT_STRING is not used.
6269
6270 PENDING if non-nil means output pending elements that belong
6271 right after this element. (PENDING is normally 1;
6272 it is 0 while outputting pending elements, to avoid recursion.) */
6273
6274 static void
6275 output_init_element (tree value, bool strict_string, tree type, tree field,
6276 int pending)
6277 {
6278 constructor_elt *celt;
6279
6280 if (type == error_mark_node || value == error_mark_node)
6281 {
6282 constructor_erroneous = 1;
6283 return;
6284 }
6285 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6286 && (TREE_CODE (value) == STRING_CST
6287 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6288 && !(TREE_CODE (value) == STRING_CST
6289 && TREE_CODE (type) == ARRAY_TYPE
6290 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6291 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6292 TYPE_MAIN_VARIANT (type)))
6293 value = array_to_pointer_conversion (value);
6294
6295 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6296 && require_constant_value && !flag_isoc99 && pending)
6297 {
6298 /* As an extension, allow initializing objects with static storage
6299 duration with compound literals (which are then treated just as
6300 the brace enclosed list they contain). */
6301 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6302 value = DECL_INITIAL (decl);
6303 }
6304
6305 if (value == error_mark_node)
6306 constructor_erroneous = 1;
6307 else if (!TREE_CONSTANT (value))
6308 constructor_constant = 0;
6309 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6310 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6311 || TREE_CODE (constructor_type) == UNION_TYPE)
6312 && DECL_C_BIT_FIELD (field)
6313 && TREE_CODE (value) != INTEGER_CST))
6314 constructor_simple = 0;
6315
6316 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6317 {
6318 if (require_constant_value)
6319 {
6320 error_init ("initializer element is not constant");
6321 value = error_mark_node;
6322 }
6323 else if (require_constant_elements)
6324 pedwarn (input_location, 0,
6325 "initializer element is not computable at load time");
6326 }
6327
6328 /* If this field is empty (and not at the end of structure),
6329 don't do anything other than checking the initializer. */
6330 if (field
6331 && (TREE_TYPE (field) == error_mark_node
6332 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6333 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6334 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6335 || TREE_CHAIN (field)))))
6336 return;
6337
6338 value = digest_init (type, value, strict_string, require_constant_value);
6339 if (value == error_mark_node)
6340 {
6341 constructor_erroneous = 1;
6342 return;
6343 }
6344
6345 /* If this element doesn't come next in sequence,
6346 put it on constructor_pending_elts. */
6347 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6348 && (!constructor_incremental
6349 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6350 {
6351 if (constructor_incremental
6352 && tree_int_cst_lt (field, constructor_unfilled_index))
6353 set_nonincremental_init ();
6354
6355 add_pending_init (field, value);
6356 return;
6357 }
6358 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6359 && (!constructor_incremental
6360 || field != constructor_unfilled_fields))
6361 {
6362 /* We do this for records but not for unions. In a union,
6363 no matter which field is specified, it can be initialized
6364 right away since it starts at the beginning of the union. */
6365 if (constructor_incremental)
6366 {
6367 if (!constructor_unfilled_fields)
6368 set_nonincremental_init ();
6369 else
6370 {
6371 tree bitpos, unfillpos;
6372
6373 bitpos = bit_position (field);
6374 unfillpos = bit_position (constructor_unfilled_fields);
6375
6376 if (tree_int_cst_lt (bitpos, unfillpos))
6377 set_nonincremental_init ();
6378 }
6379 }
6380
6381 add_pending_init (field, value);
6382 return;
6383 }
6384 else if (TREE_CODE (constructor_type) == UNION_TYPE
6385 && !VEC_empty (constructor_elt, constructor_elements))
6386 {
6387 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6388 constructor_elements)->value))
6389 warning_init (0, "initialized field with side-effects overwritten");
6390 else if (warn_override_init)
6391 warning_init (OPT_Woverride_init, "initialized field overwritten");
6392
6393 /* We can have just one union field set. */
6394 constructor_elements = 0;
6395 }
6396
6397 /* Otherwise, output this element either to
6398 constructor_elements or to the assembler file. */
6399
6400 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6401 celt->index = field;
6402 celt->value = value;
6403
6404 /* Advance the variable that indicates sequential elements output. */
6405 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6406 constructor_unfilled_index
6407 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6408 bitsize_one_node);
6409 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6410 {
6411 constructor_unfilled_fields
6412 = TREE_CHAIN (constructor_unfilled_fields);
6413
6414 /* Skip any nameless bit fields. */
6415 while (constructor_unfilled_fields != 0
6416 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6417 && DECL_NAME (constructor_unfilled_fields) == 0)
6418 constructor_unfilled_fields =
6419 TREE_CHAIN (constructor_unfilled_fields);
6420 }
6421 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6422 constructor_unfilled_fields = 0;
6423
6424 /* Now output any pending elements which have become next. */
6425 if (pending)
6426 output_pending_init_elements (0);
6427 }
6428
6429 /* Output any pending elements which have become next.
6430 As we output elements, constructor_unfilled_{fields,index}
6431 advances, which may cause other elements to become next;
6432 if so, they too are output.
6433
6434 If ALL is 0, we return when there are
6435 no more pending elements to output now.
6436
6437 If ALL is 1, we output space as necessary so that
6438 we can output all the pending elements. */
6439
6440 static void
6441 output_pending_init_elements (int all)
6442 {
6443 struct init_node *elt = constructor_pending_elts;
6444 tree next;
6445
6446 retry:
6447
6448 /* Look through the whole pending tree.
6449 If we find an element that should be output now,
6450 output it. Otherwise, set NEXT to the element
6451 that comes first among those still pending. */
6452
6453 next = 0;
6454 while (elt)
6455 {
6456 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6457 {
6458 if (tree_int_cst_equal (elt->purpose,
6459 constructor_unfilled_index))
6460 output_init_element (elt->value, true,
6461 TREE_TYPE (constructor_type),
6462 constructor_unfilled_index, 0);
6463 else if (tree_int_cst_lt (constructor_unfilled_index,
6464 elt->purpose))
6465 {
6466 /* Advance to the next smaller node. */
6467 if (elt->left)
6468 elt = elt->left;
6469 else
6470 {
6471 /* We have reached the smallest node bigger than the
6472 current unfilled index. Fill the space first. */
6473 next = elt->purpose;
6474 break;
6475 }
6476 }
6477 else
6478 {
6479 /* Advance to the next bigger node. */
6480 if (elt->right)
6481 elt = elt->right;
6482 else
6483 {
6484 /* We have reached the biggest node in a subtree. Find
6485 the parent of it, which is the next bigger node. */
6486 while (elt->parent && elt->parent->right == elt)
6487 elt = elt->parent;
6488 elt = elt->parent;
6489 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6490 elt->purpose))
6491 {
6492 next = elt->purpose;
6493 break;
6494 }
6495 }
6496 }
6497 }
6498 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6499 || TREE_CODE (constructor_type) == UNION_TYPE)
6500 {
6501 tree ctor_unfilled_bitpos, elt_bitpos;
6502
6503 /* If the current record is complete we are done. */
6504 if (constructor_unfilled_fields == 0)
6505 break;
6506
6507 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6508 elt_bitpos = bit_position (elt->purpose);
6509 /* We can't compare fields here because there might be empty
6510 fields in between. */
6511 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6512 {
6513 constructor_unfilled_fields = elt->purpose;
6514 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6515 elt->purpose, 0);
6516 }
6517 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6518 {
6519 /* Advance to the next smaller node. */
6520 if (elt->left)
6521 elt = elt->left;
6522 else
6523 {
6524 /* We have reached the smallest node bigger than the
6525 current unfilled field. Fill the space first. */
6526 next = elt->purpose;
6527 break;
6528 }
6529 }
6530 else
6531 {
6532 /* Advance to the next bigger node. */
6533 if (elt->right)
6534 elt = elt->right;
6535 else
6536 {
6537 /* We have reached the biggest node in a subtree. Find
6538 the parent of it, which is the next bigger node. */
6539 while (elt->parent && elt->parent->right == elt)
6540 elt = elt->parent;
6541 elt = elt->parent;
6542 if (elt
6543 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6544 bit_position (elt->purpose))))
6545 {
6546 next = elt->purpose;
6547 break;
6548 }
6549 }
6550 }
6551 }
6552 }
6553
6554 /* Ordinarily return, but not if we want to output all
6555 and there are elements left. */
6556 if (!(all && next != 0))
6557 return;
6558
6559 /* If it's not incremental, just skip over the gap, so that after
6560 jumping to retry we will output the next successive element. */
6561 if (TREE_CODE (constructor_type) == RECORD_TYPE
6562 || TREE_CODE (constructor_type) == UNION_TYPE)
6563 constructor_unfilled_fields = next;
6564 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6565 constructor_unfilled_index = next;
6566
6567 /* ELT now points to the node in the pending tree with the next
6568 initializer to output. */
6569 goto retry;
6570 }
6571 \f
6572 /* Add one non-braced element to the current constructor level.
6573 This adjusts the current position within the constructor's type.
6574 This may also start or terminate implicit levels
6575 to handle a partly-braced initializer.
6576
6577 Once this has found the correct level for the new element,
6578 it calls output_init_element. */
6579
6580 void
6581 process_init_element (struct c_expr value)
6582 {
6583 tree orig_value = value.value;
6584 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6585 bool strict_string = value.original_code == STRING_CST;
6586
6587 designator_depth = 0;
6588 designator_erroneous = 0;
6589
6590 /* Handle superfluous braces around string cst as in
6591 char x[] = {"foo"}; */
6592 if (string_flag
6593 && constructor_type
6594 && TREE_CODE (constructor_type) == ARRAY_TYPE
6595 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6596 && integer_zerop (constructor_unfilled_index))
6597 {
6598 if (constructor_stack->replacement_value.value)
6599 error_init ("excess elements in char array initializer");
6600 constructor_stack->replacement_value = value;
6601 return;
6602 }
6603
6604 if (constructor_stack->replacement_value.value != 0)
6605 {
6606 error_init ("excess elements in struct initializer");
6607 return;
6608 }
6609
6610 /* Ignore elements of a brace group if it is entirely superfluous
6611 and has already been diagnosed. */
6612 if (constructor_type == 0)
6613 return;
6614
6615 /* If we've exhausted any levels that didn't have braces,
6616 pop them now. */
6617 while (constructor_stack->implicit)
6618 {
6619 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6620 || TREE_CODE (constructor_type) == UNION_TYPE)
6621 && constructor_fields == 0)
6622 process_init_element (pop_init_level (1));
6623 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6624 && (constructor_max_index == 0
6625 || tree_int_cst_lt (constructor_max_index,
6626 constructor_index)))
6627 process_init_element (pop_init_level (1));
6628 else
6629 break;
6630 }
6631
6632 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6633 if (constructor_range_stack)
6634 {
6635 /* If value is a compound literal and we'll be just using its
6636 content, don't put it into a SAVE_EXPR. */
6637 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6638 || !require_constant_value
6639 || flag_isoc99)
6640 value.value = save_expr (value.value);
6641 }
6642
6643 while (1)
6644 {
6645 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6646 {
6647 tree fieldtype;
6648 enum tree_code fieldcode;
6649
6650 if (constructor_fields == 0)
6651 {
6652 pedwarn_init (input_location, 0,
6653 "excess elements in struct initializer");
6654 break;
6655 }
6656
6657 fieldtype = TREE_TYPE (constructor_fields);
6658 if (fieldtype != error_mark_node)
6659 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6660 fieldcode = TREE_CODE (fieldtype);
6661
6662 /* Error for non-static initialization of a flexible array member. */
6663 if (fieldcode == ARRAY_TYPE
6664 && !require_constant_value
6665 && TYPE_SIZE (fieldtype) == NULL_TREE
6666 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6667 {
6668 error_init ("non-static initialization of a flexible array member");
6669 break;
6670 }
6671
6672 /* Accept a string constant to initialize a subarray. */
6673 if (value.value != 0
6674 && fieldcode == ARRAY_TYPE
6675 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6676 && string_flag)
6677 value.value = orig_value;
6678 /* Otherwise, if we have come to a subaggregate,
6679 and we don't have an element of its type, push into it. */
6680 else if (value.value != 0
6681 && value.value != error_mark_node
6682 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6683 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6684 || fieldcode == UNION_TYPE))
6685 {
6686 push_init_level (1);
6687 continue;
6688 }
6689
6690 if (value.value)
6691 {
6692 push_member_name (constructor_fields);
6693 output_init_element (value.value, strict_string,
6694 fieldtype, constructor_fields, 1);
6695 RESTORE_SPELLING_DEPTH (constructor_depth);
6696 }
6697 else
6698 /* Do the bookkeeping for an element that was
6699 directly output as a constructor. */
6700 {
6701 /* For a record, keep track of end position of last field. */
6702 if (DECL_SIZE (constructor_fields))
6703 constructor_bit_index
6704 = size_binop (PLUS_EXPR,
6705 bit_position (constructor_fields),
6706 DECL_SIZE (constructor_fields));
6707
6708 /* If the current field was the first one not yet written out,
6709 it isn't now, so update. */
6710 if (constructor_unfilled_fields == constructor_fields)
6711 {
6712 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6713 /* Skip any nameless bit fields. */
6714 while (constructor_unfilled_fields != 0
6715 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6716 && DECL_NAME (constructor_unfilled_fields) == 0)
6717 constructor_unfilled_fields =
6718 TREE_CHAIN (constructor_unfilled_fields);
6719 }
6720 }
6721
6722 constructor_fields = TREE_CHAIN (constructor_fields);
6723 /* Skip any nameless bit fields at the beginning. */
6724 while (constructor_fields != 0
6725 && DECL_C_BIT_FIELD (constructor_fields)
6726 && DECL_NAME (constructor_fields) == 0)
6727 constructor_fields = TREE_CHAIN (constructor_fields);
6728 }
6729 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6730 {
6731 tree fieldtype;
6732 enum tree_code fieldcode;
6733
6734 if (constructor_fields == 0)
6735 {
6736 pedwarn_init (input_location, 0,
6737 "excess elements in union initializer");
6738 break;
6739 }
6740
6741 fieldtype = TREE_TYPE (constructor_fields);
6742 if (fieldtype != error_mark_node)
6743 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6744 fieldcode = TREE_CODE (fieldtype);
6745
6746 /* Warn that traditional C rejects initialization of unions.
6747 We skip the warning if the value is zero. This is done
6748 under the assumption that the zero initializer in user
6749 code appears conditioned on e.g. __STDC__ to avoid
6750 "missing initializer" warnings and relies on default
6751 initialization to zero in the traditional C case.
6752 We also skip the warning if the initializer is designated,
6753 again on the assumption that this must be conditional on
6754 __STDC__ anyway (and we've already complained about the
6755 member-designator already). */
6756 if (!in_system_header && !constructor_designated
6757 && !(value.value && (integer_zerop (value.value)
6758 || real_zerop (value.value))))
6759 warning (OPT_Wtraditional, "traditional C rejects initialization "
6760 "of unions");
6761
6762 /* Accept a string constant to initialize a subarray. */
6763 if (value.value != 0
6764 && fieldcode == ARRAY_TYPE
6765 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6766 && string_flag)
6767 value.value = orig_value;
6768 /* Otherwise, if we have come to a subaggregate,
6769 and we don't have an element of its type, push into it. */
6770 else if (value.value != 0
6771 && value.value != error_mark_node
6772 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6773 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6774 || fieldcode == UNION_TYPE))
6775 {
6776 push_init_level (1);
6777 continue;
6778 }
6779
6780 if (value.value)
6781 {
6782 push_member_name (constructor_fields);
6783 output_init_element (value.value, strict_string,
6784 fieldtype, constructor_fields, 1);
6785 RESTORE_SPELLING_DEPTH (constructor_depth);
6786 }
6787 else
6788 /* Do the bookkeeping for an element that was
6789 directly output as a constructor. */
6790 {
6791 constructor_bit_index = DECL_SIZE (constructor_fields);
6792 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6793 }
6794
6795 constructor_fields = 0;
6796 }
6797 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6798 {
6799 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6800 enum tree_code eltcode = TREE_CODE (elttype);
6801
6802 /* Accept a string constant to initialize a subarray. */
6803 if (value.value != 0
6804 && eltcode == ARRAY_TYPE
6805 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6806 && string_flag)
6807 value.value = orig_value;
6808 /* Otherwise, if we have come to a subaggregate,
6809 and we don't have an element of its type, push into it. */
6810 else if (value.value != 0
6811 && value.value != error_mark_node
6812 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6813 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6814 || eltcode == UNION_TYPE))
6815 {
6816 push_init_level (1);
6817 continue;
6818 }
6819
6820 if (constructor_max_index != 0
6821 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6822 || integer_all_onesp (constructor_max_index)))
6823 {
6824 pedwarn_init (input_location, 0,
6825 "excess elements in array initializer");
6826 break;
6827 }
6828
6829 /* Now output the actual element. */
6830 if (value.value)
6831 {
6832 push_array_bounds (tree_low_cst (constructor_index, 1));
6833 output_init_element (value.value, strict_string,
6834 elttype, constructor_index, 1);
6835 RESTORE_SPELLING_DEPTH (constructor_depth);
6836 }
6837
6838 constructor_index
6839 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6840
6841 if (!value.value)
6842 /* If we are doing the bookkeeping for an element that was
6843 directly output as a constructor, we must update
6844 constructor_unfilled_index. */
6845 constructor_unfilled_index = constructor_index;
6846 }
6847 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6848 {
6849 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6850
6851 /* Do a basic check of initializer size. Note that vectors
6852 always have a fixed size derived from their type. */
6853 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6854 {
6855 pedwarn_init (input_location, 0,
6856 "excess elements in vector initializer");
6857 break;
6858 }
6859
6860 /* Now output the actual element. */
6861 if (value.value)
6862 output_init_element (value.value, strict_string,
6863 elttype, constructor_index, 1);
6864
6865 constructor_index
6866 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6867
6868 if (!value.value)
6869 /* If we are doing the bookkeeping for an element that was
6870 directly output as a constructor, we must update
6871 constructor_unfilled_index. */
6872 constructor_unfilled_index = constructor_index;
6873 }
6874
6875 /* Handle the sole element allowed in a braced initializer
6876 for a scalar variable. */
6877 else if (constructor_type != error_mark_node
6878 && constructor_fields == 0)
6879 {
6880 pedwarn_init (input_location, 0,
6881 "excess elements in scalar initializer");
6882 break;
6883 }
6884 else
6885 {
6886 if (value.value)
6887 output_init_element (value.value, strict_string,
6888 constructor_type, NULL_TREE, 1);
6889 constructor_fields = 0;
6890 }
6891
6892 /* Handle range initializers either at this level or anywhere higher
6893 in the designator stack. */
6894 if (constructor_range_stack)
6895 {
6896 struct constructor_range_stack *p, *range_stack;
6897 int finish = 0;
6898
6899 range_stack = constructor_range_stack;
6900 constructor_range_stack = 0;
6901 while (constructor_stack != range_stack->stack)
6902 {
6903 gcc_assert (constructor_stack->implicit);
6904 process_init_element (pop_init_level (1));
6905 }
6906 for (p = range_stack;
6907 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6908 p = p->prev)
6909 {
6910 gcc_assert (constructor_stack->implicit);
6911 process_init_element (pop_init_level (1));
6912 }
6913
6914 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6915 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6916 finish = 1;
6917
6918 while (1)
6919 {
6920 constructor_index = p->index;
6921 constructor_fields = p->fields;
6922 if (finish && p->range_end && p->index == p->range_start)
6923 {
6924 finish = 0;
6925 p->prev = 0;
6926 }
6927 p = p->next;
6928 if (!p)
6929 break;
6930 push_init_level (2);
6931 p->stack = constructor_stack;
6932 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6933 p->index = p->range_start;
6934 }
6935
6936 if (!finish)
6937 constructor_range_stack = range_stack;
6938 continue;
6939 }
6940
6941 break;
6942 }
6943
6944 constructor_range_stack = 0;
6945 }
6946 \f
6947 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6948 (guaranteed to be 'volatile' or null) and ARGS (represented using
6949 an ASM_EXPR node). */
6950 tree
6951 build_asm_stmt (tree cv_qualifier, tree args)
6952 {
6953 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6954 ASM_VOLATILE_P (args) = 1;
6955 return add_stmt (args);
6956 }
6957
6958 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6959 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6960 SIMPLE indicates whether there was anything at all after the
6961 string in the asm expression -- asm("blah") and asm("blah" : )
6962 are subtly different. We use a ASM_EXPR node to represent this. */
6963 tree
6964 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6965 bool simple)
6966 {
6967 tree tail;
6968 tree args;
6969 int i;
6970 const char *constraint;
6971 const char **oconstraints;
6972 bool allows_mem, allows_reg, is_inout;
6973 int ninputs, noutputs;
6974
6975 ninputs = list_length (inputs);
6976 noutputs = list_length (outputs);
6977 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6978
6979 string = resolve_asm_operand_names (string, outputs, inputs);
6980
6981 /* Remove output conversions that change the type but not the mode. */
6982 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6983 {
6984 tree output = TREE_VALUE (tail);
6985
6986 /* ??? Really, this should not be here. Users should be using a
6987 proper lvalue, dammit. But there's a long history of using casts
6988 in the output operands. In cases like longlong.h, this becomes a
6989 primitive form of typechecking -- if the cast can be removed, then
6990 the output operand had a type of the proper width; otherwise we'll
6991 get an error. Gross, but ... */
6992 STRIP_NOPS (output);
6993
6994 if (!lvalue_or_else (output, lv_asm))
6995 output = error_mark_node;
6996
6997 if (output != error_mark_node
6998 && (TREE_READONLY (output)
6999 || TYPE_READONLY (TREE_TYPE (output))
7000 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
7001 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
7002 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
7003 readonly_error (output, lv_asm);
7004
7005 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
7006 oconstraints[i] = constraint;
7007
7008 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
7009 &allows_mem, &allows_reg, &is_inout))
7010 {
7011 /* If the operand is going to end up in memory,
7012 mark it addressable. */
7013 if (!allows_reg && !c_mark_addressable (output))
7014 output = error_mark_node;
7015 }
7016 else
7017 output = error_mark_node;
7018
7019 TREE_VALUE (tail) = output;
7020 }
7021
7022 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
7023 {
7024 tree input;
7025
7026 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
7027 input = TREE_VALUE (tail);
7028
7029 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
7030 oconstraints, &allows_mem, &allows_reg))
7031 {
7032 /* If the operand is going to end up in memory,
7033 mark it addressable. */
7034 if (!allows_reg && allows_mem)
7035 {
7036 /* Strip the nops as we allow this case. FIXME, this really
7037 should be rejected or made deprecated. */
7038 STRIP_NOPS (input);
7039 if (!c_mark_addressable (input))
7040 input = error_mark_node;
7041 }
7042 }
7043 else
7044 input = error_mark_node;
7045
7046 TREE_VALUE (tail) = input;
7047 }
7048
7049 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
7050
7051 /* asm statements without outputs, including simple ones, are treated
7052 as volatile. */
7053 ASM_INPUT_P (args) = simple;
7054 ASM_VOLATILE_P (args) = (noutputs == 0);
7055
7056 return args;
7057 }
7058 \f
7059 /* Generate a goto statement to LABEL. */
7060
7061 tree
7062 c_finish_goto_label (tree label)
7063 {
7064 tree decl = lookup_label (label);
7065 if (!decl)
7066 return NULL_TREE;
7067
7068 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
7069 {
7070 error ("jump into statement expression");
7071 return NULL_TREE;
7072 }
7073
7074 if (C_DECL_UNJUMPABLE_VM (decl))
7075 {
7076 error ("jump into scope of identifier with variably modified type");
7077 return NULL_TREE;
7078 }
7079
7080 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
7081 {
7082 /* No jump from outside this statement expression context, so
7083 record that there is a jump from within this context. */
7084 struct c_label_list *nlist;
7085 nlist = XOBNEW (&parser_obstack, struct c_label_list);
7086 nlist->next = label_context_stack_se->labels_used;
7087 nlist->label = decl;
7088 label_context_stack_se->labels_used = nlist;
7089 }
7090
7091 if (!C_DECL_UNDEFINABLE_VM (decl))
7092 {
7093 /* No jump from outside this context context of identifiers with
7094 variably modified type, so record that there is a jump from
7095 within this context. */
7096 struct c_label_list *nlist;
7097 nlist = XOBNEW (&parser_obstack, struct c_label_list);
7098 nlist->next = label_context_stack_vm->labels_used;
7099 nlist->label = decl;
7100 label_context_stack_vm->labels_used = nlist;
7101 }
7102
7103 TREE_USED (decl) = 1;
7104 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
7105 }
7106
7107 /* Generate a computed goto statement to EXPR. */
7108
7109 tree
7110 c_finish_goto_ptr (tree expr)
7111 {
7112 pedwarn (input_location, OPT_pedantic, "ISO C forbids %<goto *expr;%>");
7113 expr = convert (ptr_type_node, expr);
7114 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
7115 }
7116
7117 /* Generate a C `return' statement. RETVAL is the expression for what
7118 to return, or a null pointer for `return;' with no value. */
7119
7120 tree
7121 c_finish_return (tree retval)
7122 {
7123 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
7124 bool no_warning = false;
7125
7126 if (TREE_THIS_VOLATILE (current_function_decl))
7127 warning (0, "function declared %<noreturn%> has a %<return%> statement");
7128
7129 if (!retval)
7130 {
7131 current_function_returns_null = 1;
7132 if ((warn_return_type || flag_isoc99)
7133 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
7134 {
7135 pedwarn_c99 (input_location, flag_isoc99 ? 0 : OPT_Wreturn_type,
7136 "%<return%> with no value, in "
7137 "function returning non-void");
7138 no_warning = true;
7139 }
7140 }
7141 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
7142 {
7143 current_function_returns_null = 1;
7144 if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
7145 pedwarn (input_location, 0,
7146 "%<return%> with a value, in function returning void");
7147 else
7148 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
7149 "%<return%> with expression, in function returning void");
7150 }
7151 else
7152 {
7153 tree t = convert_for_assignment (valtype, retval, ic_return,
7154 NULL_TREE, NULL_TREE, 0);
7155 tree res = DECL_RESULT (current_function_decl);
7156 tree inner;
7157
7158 current_function_returns_value = 1;
7159 if (t == error_mark_node)
7160 return NULL_TREE;
7161
7162 inner = t = convert (TREE_TYPE (res), t);
7163
7164 /* Strip any conversions, additions, and subtractions, and see if
7165 we are returning the address of a local variable. Warn if so. */
7166 while (1)
7167 {
7168 switch (TREE_CODE (inner))
7169 {
7170 CASE_CONVERT: case NON_LVALUE_EXPR:
7171 case PLUS_EXPR:
7172 inner = TREE_OPERAND (inner, 0);
7173 continue;
7174
7175 case MINUS_EXPR:
7176 /* If the second operand of the MINUS_EXPR has a pointer
7177 type (or is converted from it), this may be valid, so
7178 don't give a warning. */
7179 {
7180 tree op1 = TREE_OPERAND (inner, 1);
7181
7182 while (!POINTER_TYPE_P (TREE_TYPE (op1))
7183 && (CONVERT_EXPR_P (op1)
7184 || TREE_CODE (op1) == NON_LVALUE_EXPR))
7185 op1 = TREE_OPERAND (op1, 0);
7186
7187 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7188 break;
7189
7190 inner = TREE_OPERAND (inner, 0);
7191 continue;
7192 }
7193
7194 case ADDR_EXPR:
7195 inner = TREE_OPERAND (inner, 0);
7196
7197 while (REFERENCE_CLASS_P (inner)
7198 && TREE_CODE (inner) != INDIRECT_REF)
7199 inner = TREE_OPERAND (inner, 0);
7200
7201 if (DECL_P (inner)
7202 && !DECL_EXTERNAL (inner)
7203 && !TREE_STATIC (inner)
7204 && DECL_CONTEXT (inner) == current_function_decl)
7205 warning (0, "function returns address of local variable");
7206 break;
7207
7208 default:
7209 break;
7210 }
7211
7212 break;
7213 }
7214
7215 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7216
7217 if (warn_sequence_point)
7218 verify_sequence_points (retval);
7219 }
7220
7221 ret_stmt = build_stmt (RETURN_EXPR, retval);
7222 TREE_NO_WARNING (ret_stmt) |= no_warning;
7223 return add_stmt (ret_stmt);
7224 }
7225 \f
7226 struct c_switch {
7227 /* The SWITCH_EXPR being built. */
7228 tree switch_expr;
7229
7230 /* The original type of the testing expression, i.e. before the
7231 default conversion is applied. */
7232 tree orig_type;
7233
7234 /* A splay-tree mapping the low element of a case range to the high
7235 element, or NULL_TREE if there is no high element. Used to
7236 determine whether or not a new case label duplicates an old case
7237 label. We need a tree, rather than simply a hash table, because
7238 of the GNU case range extension. */
7239 splay_tree cases;
7240
7241 /* Number of nested statement expressions within this switch
7242 statement; if nonzero, case and default labels may not
7243 appear. */
7244 unsigned int blocked_stmt_expr;
7245
7246 /* Scope of outermost declarations of identifiers with variably
7247 modified type within this switch statement; if nonzero, case and
7248 default labels may not appear. */
7249 unsigned int blocked_vm;
7250
7251 /* The next node on the stack. */
7252 struct c_switch *next;
7253 };
7254
7255 /* A stack of the currently active switch statements. The innermost
7256 switch statement is on the top of the stack. There is no need to
7257 mark the stack for garbage collection because it is only active
7258 during the processing of the body of a function, and we never
7259 collect at that point. */
7260
7261 struct c_switch *c_switch_stack;
7262
7263 /* Start a C switch statement, testing expression EXP. Return the new
7264 SWITCH_EXPR. */
7265
7266 tree
7267 c_start_case (tree exp)
7268 {
7269 tree orig_type = error_mark_node;
7270 struct c_switch *cs;
7271
7272 if (exp != error_mark_node)
7273 {
7274 orig_type = TREE_TYPE (exp);
7275
7276 if (!INTEGRAL_TYPE_P (orig_type))
7277 {
7278 if (orig_type != error_mark_node)
7279 {
7280 error ("switch quantity not an integer");
7281 orig_type = error_mark_node;
7282 }
7283 exp = integer_zero_node;
7284 }
7285 else
7286 {
7287 tree type = TYPE_MAIN_VARIANT (orig_type);
7288
7289 if (!in_system_header
7290 && (type == long_integer_type_node
7291 || type == long_unsigned_type_node))
7292 warning (OPT_Wtraditional, "%<long%> switch expression not "
7293 "converted to %<int%> in ISO C");
7294
7295 exp = default_conversion (exp);
7296
7297 if (warn_sequence_point)
7298 verify_sequence_points (exp);
7299 }
7300 }
7301
7302 /* Add this new SWITCH_EXPR to the stack. */
7303 cs = XNEW (struct c_switch);
7304 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7305 cs->orig_type = orig_type;
7306 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7307 cs->blocked_stmt_expr = 0;
7308 cs->blocked_vm = 0;
7309 cs->next = c_switch_stack;
7310 c_switch_stack = cs;
7311
7312 return add_stmt (cs->switch_expr);
7313 }
7314
7315 /* Process a case label. */
7316
7317 tree
7318 do_case (tree low_value, tree high_value)
7319 {
7320 tree label = NULL_TREE;
7321
7322 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7323 && !c_switch_stack->blocked_vm)
7324 {
7325 label = c_add_case_label (c_switch_stack->cases,
7326 SWITCH_COND (c_switch_stack->switch_expr),
7327 c_switch_stack->orig_type,
7328 low_value, high_value);
7329 if (label == error_mark_node)
7330 label = NULL_TREE;
7331 }
7332 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7333 {
7334 if (low_value)
7335 error ("case label in statement expression not containing "
7336 "enclosing switch statement");
7337 else
7338 error ("%<default%> label in statement expression not containing "
7339 "enclosing switch statement");
7340 }
7341 else if (c_switch_stack && c_switch_stack->blocked_vm)
7342 {
7343 if (low_value)
7344 error ("case label in scope of identifier with variably modified "
7345 "type not containing enclosing switch statement");
7346 else
7347 error ("%<default%> label in scope of identifier with variably "
7348 "modified type not containing enclosing switch statement");
7349 }
7350 else if (low_value)
7351 error ("case label not within a switch statement");
7352 else
7353 error ("%<default%> label not within a switch statement");
7354
7355 return label;
7356 }
7357
7358 /* Finish the switch statement. */
7359
7360 void
7361 c_finish_case (tree body)
7362 {
7363 struct c_switch *cs = c_switch_stack;
7364 location_t switch_location;
7365
7366 SWITCH_BODY (cs->switch_expr) = body;
7367
7368 /* We must not be within a statement expression nested in the switch
7369 at this point; we might, however, be within the scope of an
7370 identifier with variably modified type nested in the switch. */
7371 gcc_assert (!cs->blocked_stmt_expr);
7372
7373 /* Emit warnings as needed. */
7374 if (EXPR_HAS_LOCATION (cs->switch_expr))
7375 switch_location = EXPR_LOCATION (cs->switch_expr);
7376 else
7377 switch_location = input_location;
7378 c_do_switch_warnings (cs->cases, switch_location,
7379 TREE_TYPE (cs->switch_expr),
7380 SWITCH_COND (cs->switch_expr));
7381
7382 /* Pop the stack. */
7383 c_switch_stack = cs->next;
7384 splay_tree_delete (cs->cases);
7385 XDELETE (cs);
7386 }
7387 \f
7388 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7389 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7390 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7391 statement, and was not surrounded with parenthesis. */
7392
7393 void
7394 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7395 tree else_block, bool nested_if)
7396 {
7397 tree stmt;
7398
7399 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7400 if (warn_parentheses && nested_if && else_block == NULL)
7401 {
7402 tree inner_if = then_block;
7403
7404 /* We know from the grammar productions that there is an IF nested
7405 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7406 it might not be exactly THEN_BLOCK, but should be the last
7407 non-container statement within. */
7408 while (1)
7409 switch (TREE_CODE (inner_if))
7410 {
7411 case COND_EXPR:
7412 goto found;
7413 case BIND_EXPR:
7414 inner_if = BIND_EXPR_BODY (inner_if);
7415 break;
7416 case STATEMENT_LIST:
7417 inner_if = expr_last (then_block);
7418 break;
7419 case TRY_FINALLY_EXPR:
7420 case TRY_CATCH_EXPR:
7421 inner_if = TREE_OPERAND (inner_if, 0);
7422 break;
7423 default:
7424 gcc_unreachable ();
7425 }
7426 found:
7427
7428 if (COND_EXPR_ELSE (inner_if))
7429 warning (OPT_Wparentheses,
7430 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7431 &if_locus);
7432 }
7433
7434 empty_if_body_warning (then_block, else_block);
7435
7436 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7437 SET_EXPR_LOCATION (stmt, if_locus);
7438 add_stmt (stmt);
7439 }
7440
7441 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7442 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7443 is false for DO loops. INCR is the FOR increment expression. BODY is
7444 the statement controlled by the loop. BLAB is the break label. CLAB is
7445 the continue label. Everything is allowed to be NULL. */
7446
7447 void
7448 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7449 tree blab, tree clab, bool cond_is_first)
7450 {
7451 tree entry = NULL, exit = NULL, t;
7452
7453 /* If the condition is zero don't generate a loop construct. */
7454 if (cond && integer_zerop (cond))
7455 {
7456 if (cond_is_first)
7457 {
7458 t = build_and_jump (&blab);
7459 SET_EXPR_LOCATION (t, start_locus);
7460 add_stmt (t);
7461 }
7462 }
7463 else
7464 {
7465 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7466
7467 /* If we have an exit condition, then we build an IF with gotos either
7468 out of the loop, or to the top of it. If there's no exit condition,
7469 then we just build a jump back to the top. */
7470 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7471
7472 if (cond && !integer_nonzerop (cond))
7473 {
7474 /* Canonicalize the loop condition to the end. This means
7475 generating a branch to the loop condition. Reuse the
7476 continue label, if possible. */
7477 if (cond_is_first)
7478 {
7479 if (incr || !clab)
7480 {
7481 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7482 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7483 }
7484 else
7485 t = build1 (GOTO_EXPR, void_type_node, clab);
7486 SET_EXPR_LOCATION (t, start_locus);
7487 add_stmt (t);
7488 }
7489
7490 t = build_and_jump (&blab);
7491 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7492 if (cond_is_first)
7493 SET_EXPR_LOCATION (exit, start_locus);
7494 else
7495 SET_EXPR_LOCATION (exit, input_location);
7496 }
7497
7498 add_stmt (top);
7499 }
7500
7501 if (body)
7502 add_stmt (body);
7503 if (clab)
7504 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7505 if (incr)
7506 add_stmt (incr);
7507 if (entry)
7508 add_stmt (entry);
7509 if (exit)
7510 add_stmt (exit);
7511 if (blab)
7512 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7513 }
7514
7515 tree
7516 c_finish_bc_stmt (tree *label_p, bool is_break)
7517 {
7518 bool skip;
7519 tree label = *label_p;
7520
7521 /* In switch statements break is sometimes stylistically used after
7522 a return statement. This can lead to spurious warnings about
7523 control reaching the end of a non-void function when it is
7524 inlined. Note that we are calling block_may_fallthru with
7525 language specific tree nodes; this works because
7526 block_may_fallthru returns true when given something it does not
7527 understand. */
7528 skip = !block_may_fallthru (cur_stmt_list);
7529
7530 if (!label)
7531 {
7532 if (!skip)
7533 *label_p = label = create_artificial_label ();
7534 }
7535 else if (TREE_CODE (label) == LABEL_DECL)
7536 ;
7537 else switch (TREE_INT_CST_LOW (label))
7538 {
7539 case 0:
7540 if (is_break)
7541 error ("break statement not within loop or switch");
7542 else
7543 error ("continue statement not within a loop");
7544 return NULL_TREE;
7545
7546 case 1:
7547 gcc_assert (is_break);
7548 error ("break statement used with OpenMP for loop");
7549 return NULL_TREE;
7550
7551 default:
7552 gcc_unreachable ();
7553 }
7554
7555 if (skip)
7556 return NULL_TREE;
7557
7558 if (!is_break)
7559 add_stmt (build_predict_expr (PRED_CONTINUE, NOT_TAKEN));
7560
7561 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7562 }
7563
7564 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7565
7566 static void
7567 emit_side_effect_warnings (tree expr)
7568 {
7569 if (expr == error_mark_node)
7570 ;
7571 else if (!TREE_SIDE_EFFECTS (expr))
7572 {
7573 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7574 warning (OPT_Wunused_value, "%Hstatement with no effect",
7575 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7576 }
7577 else
7578 warn_if_unused_value (expr, input_location);
7579 }
7580
7581 /* Process an expression as if it were a complete statement. Emit
7582 diagnostics, but do not call ADD_STMT. */
7583
7584 tree
7585 c_process_expr_stmt (tree expr)
7586 {
7587 if (!expr)
7588 return NULL_TREE;
7589
7590 if (warn_sequence_point)
7591 verify_sequence_points (expr);
7592
7593 if (TREE_TYPE (expr) != error_mark_node
7594 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7595 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7596 error ("expression statement has incomplete type");
7597
7598 /* If we're not processing a statement expression, warn about unused values.
7599 Warnings for statement expressions will be emitted later, once we figure
7600 out which is the result. */
7601 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7602 && warn_unused_value)
7603 emit_side_effect_warnings (expr);
7604
7605 /* If the expression is not of a type to which we cannot assign a line
7606 number, wrap the thing in a no-op NOP_EXPR. */
7607 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7608 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7609
7610 if (CAN_HAVE_LOCATION_P (expr))
7611 SET_EXPR_LOCATION (expr, input_location);
7612
7613 return expr;
7614 }
7615
7616 /* Emit an expression as a statement. */
7617
7618 tree
7619 c_finish_expr_stmt (tree expr)
7620 {
7621 if (expr)
7622 return add_stmt (c_process_expr_stmt (expr));
7623 else
7624 return NULL;
7625 }
7626
7627 /* Do the opposite and emit a statement as an expression. To begin,
7628 create a new binding level and return it. */
7629
7630 tree
7631 c_begin_stmt_expr (void)
7632 {
7633 tree ret;
7634 struct c_label_context_se *nstack;
7635 struct c_label_list *glist;
7636
7637 /* We must force a BLOCK for this level so that, if it is not expanded
7638 later, there is a way to turn off the entire subtree of blocks that
7639 are contained in it. */
7640 keep_next_level ();
7641 ret = c_begin_compound_stmt (true);
7642 if (c_switch_stack)
7643 {
7644 c_switch_stack->blocked_stmt_expr++;
7645 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7646 }
7647 for (glist = label_context_stack_se->labels_used;
7648 glist != NULL;
7649 glist = glist->next)
7650 {
7651 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7652 }
7653 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7654 nstack->labels_def = NULL;
7655 nstack->labels_used = NULL;
7656 nstack->next = label_context_stack_se;
7657 label_context_stack_se = nstack;
7658
7659 /* Mark the current statement list as belonging to a statement list. */
7660 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7661
7662 return ret;
7663 }
7664
7665 tree
7666 c_finish_stmt_expr (tree body)
7667 {
7668 tree last, type, tmp, val;
7669 tree *last_p;
7670 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7671
7672 body = c_end_compound_stmt (body, true);
7673 if (c_switch_stack)
7674 {
7675 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7676 c_switch_stack->blocked_stmt_expr--;
7677 }
7678 /* It is no longer possible to jump to labels defined within this
7679 statement expression. */
7680 for (dlist = label_context_stack_se->labels_def;
7681 dlist != NULL;
7682 dlist = dlist->next)
7683 {
7684 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7685 }
7686 /* It is again possible to define labels with a goto just outside
7687 this statement expression. */
7688 for (glist = label_context_stack_se->next->labels_used;
7689 glist != NULL;
7690 glist = glist->next)
7691 {
7692 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7693 glist_prev = glist;
7694 }
7695 if (glist_prev != NULL)
7696 glist_prev->next = label_context_stack_se->labels_used;
7697 else
7698 label_context_stack_se->next->labels_used
7699 = label_context_stack_se->labels_used;
7700 label_context_stack_se = label_context_stack_se->next;
7701
7702 /* Locate the last statement in BODY. See c_end_compound_stmt
7703 about always returning a BIND_EXPR. */
7704 last_p = &BIND_EXPR_BODY (body);
7705 last = BIND_EXPR_BODY (body);
7706
7707 continue_searching:
7708 if (TREE_CODE (last) == STATEMENT_LIST)
7709 {
7710 tree_stmt_iterator i;
7711
7712 /* This can happen with degenerate cases like ({ }). No value. */
7713 if (!TREE_SIDE_EFFECTS (last))
7714 return body;
7715
7716 /* If we're supposed to generate side effects warnings, process
7717 all of the statements except the last. */
7718 if (warn_unused_value)
7719 {
7720 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7721 emit_side_effect_warnings (tsi_stmt (i));
7722 }
7723 else
7724 i = tsi_last (last);
7725 last_p = tsi_stmt_ptr (i);
7726 last = *last_p;
7727 }
7728
7729 /* If the end of the list is exception related, then the list was split
7730 by a call to push_cleanup. Continue searching. */
7731 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7732 || TREE_CODE (last) == TRY_CATCH_EXPR)
7733 {
7734 last_p = &TREE_OPERAND (last, 0);
7735 last = *last_p;
7736 goto continue_searching;
7737 }
7738
7739 /* In the case that the BIND_EXPR is not necessary, return the
7740 expression out from inside it. */
7741 if (last == error_mark_node
7742 || (last == BIND_EXPR_BODY (body)
7743 && BIND_EXPR_VARS (body) == NULL))
7744 {
7745 /* Do not warn if the return value of a statement expression is
7746 unused. */
7747 if (CAN_HAVE_LOCATION_P (last))
7748 TREE_NO_WARNING (last) = 1;
7749 return last;
7750 }
7751
7752 /* Extract the type of said expression. */
7753 type = TREE_TYPE (last);
7754
7755 /* If we're not returning a value at all, then the BIND_EXPR that
7756 we already have is a fine expression to return. */
7757 if (!type || VOID_TYPE_P (type))
7758 return body;
7759
7760 /* Now that we've located the expression containing the value, it seems
7761 silly to make voidify_wrapper_expr repeat the process. Create a
7762 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7763 tmp = create_tmp_var_raw (type, NULL);
7764
7765 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7766 tree_expr_nonnegative_p giving up immediately. */
7767 val = last;
7768 if (TREE_CODE (val) == NOP_EXPR
7769 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7770 val = TREE_OPERAND (val, 0);
7771
7772 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7773 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7774
7775 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7776 }
7777
7778 /* Begin the scope of an identifier of variably modified type, scope
7779 number SCOPE. Jumping from outside this scope to inside it is not
7780 permitted. */
7781
7782 void
7783 c_begin_vm_scope (unsigned int scope)
7784 {
7785 struct c_label_context_vm *nstack;
7786 struct c_label_list *glist;
7787
7788 gcc_assert (scope > 0);
7789
7790 /* At file_scope, we don't have to do any processing. */
7791 if (label_context_stack_vm == NULL)
7792 return;
7793
7794 if (c_switch_stack && !c_switch_stack->blocked_vm)
7795 c_switch_stack->blocked_vm = scope;
7796 for (glist = label_context_stack_vm->labels_used;
7797 glist != NULL;
7798 glist = glist->next)
7799 {
7800 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7801 }
7802 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7803 nstack->labels_def = NULL;
7804 nstack->labels_used = NULL;
7805 nstack->scope = scope;
7806 nstack->next = label_context_stack_vm;
7807 label_context_stack_vm = nstack;
7808 }
7809
7810 /* End a scope which may contain identifiers of variably modified
7811 type, scope number SCOPE. */
7812
7813 void
7814 c_end_vm_scope (unsigned int scope)
7815 {
7816 if (label_context_stack_vm == NULL)
7817 return;
7818 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7819 c_switch_stack->blocked_vm = 0;
7820 /* We may have a number of nested scopes of identifiers with
7821 variably modified type, all at this depth. Pop each in turn. */
7822 while (label_context_stack_vm->scope == scope)
7823 {
7824 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7825
7826 /* It is no longer possible to jump to labels defined within this
7827 scope. */
7828 for (dlist = label_context_stack_vm->labels_def;
7829 dlist != NULL;
7830 dlist = dlist->next)
7831 {
7832 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7833 }
7834 /* It is again possible to define labels with a goto just outside
7835 this scope. */
7836 for (glist = label_context_stack_vm->next->labels_used;
7837 glist != NULL;
7838 glist = glist->next)
7839 {
7840 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7841 glist_prev = glist;
7842 }
7843 if (glist_prev != NULL)
7844 glist_prev->next = label_context_stack_vm->labels_used;
7845 else
7846 label_context_stack_vm->next->labels_used
7847 = label_context_stack_vm->labels_used;
7848 label_context_stack_vm = label_context_stack_vm->next;
7849 }
7850 }
7851 \f
7852 /* Begin and end compound statements. This is as simple as pushing
7853 and popping new statement lists from the tree. */
7854
7855 tree
7856 c_begin_compound_stmt (bool do_scope)
7857 {
7858 tree stmt = push_stmt_list ();
7859 if (do_scope)
7860 push_scope ();
7861 return stmt;
7862 }
7863
7864 tree
7865 c_end_compound_stmt (tree stmt, bool do_scope)
7866 {
7867 tree block = NULL;
7868
7869 if (do_scope)
7870 {
7871 if (c_dialect_objc ())
7872 objc_clear_super_receiver ();
7873 block = pop_scope ();
7874 }
7875
7876 stmt = pop_stmt_list (stmt);
7877 stmt = c_build_bind_expr (block, stmt);
7878
7879 /* If this compound statement is nested immediately inside a statement
7880 expression, then force a BIND_EXPR to be created. Otherwise we'll
7881 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7882 STATEMENT_LISTs merge, and thus we can lose track of what statement
7883 was really last. */
7884 if (cur_stmt_list
7885 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7886 && TREE_CODE (stmt) != BIND_EXPR)
7887 {
7888 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7889 TREE_SIDE_EFFECTS (stmt) = 1;
7890 }
7891
7892 return stmt;
7893 }
7894
7895 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7896 when the current scope is exited. EH_ONLY is true when this is not
7897 meant to apply to normal control flow transfer. */
7898
7899 void
7900 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7901 {
7902 enum tree_code code;
7903 tree stmt, list;
7904 bool stmt_expr;
7905
7906 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7907 stmt = build_stmt (code, NULL, cleanup);
7908 add_stmt (stmt);
7909 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7910 list = push_stmt_list ();
7911 TREE_OPERAND (stmt, 0) = list;
7912 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7913 }
7914 \f
7915 /* Build a binary-operation expression without default conversions.
7916 CODE is the kind of expression to build.
7917 This function differs from `build' in several ways:
7918 the data type of the result is computed and recorded in it,
7919 warnings are generated if arg data types are invalid,
7920 special handling for addition and subtraction of pointers is known,
7921 and some optimization is done (operations on narrow ints
7922 are done in the narrower type when that gives the same result).
7923 Constant folding is also done before the result is returned.
7924
7925 Note that the operands will never have enumeral types, or function
7926 or array types, because either they will have the default conversions
7927 performed or they have both just been converted to some other type in which
7928 the arithmetic is to be done. */
7929
7930 tree
7931 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7932 int convert_p)
7933 {
7934 tree type0, type1;
7935 enum tree_code code0, code1;
7936 tree op0, op1;
7937 const char *invalid_op_diag;
7938
7939 /* Expression code to give to the expression when it is built.
7940 Normally this is CODE, which is what the caller asked for,
7941 but in some special cases we change it. */
7942 enum tree_code resultcode = code;
7943
7944 /* Data type in which the computation is to be performed.
7945 In the simplest cases this is the common type of the arguments. */
7946 tree result_type = NULL;
7947
7948 /* Nonzero means operands have already been type-converted
7949 in whatever way is necessary.
7950 Zero means they need to be converted to RESULT_TYPE. */
7951 int converted = 0;
7952
7953 /* Nonzero means create the expression with this type, rather than
7954 RESULT_TYPE. */
7955 tree build_type = 0;
7956
7957 /* Nonzero means after finally constructing the expression
7958 convert it to this type. */
7959 tree final_type = 0;
7960
7961 /* Nonzero if this is an operation like MIN or MAX which can
7962 safely be computed in short if both args are promoted shorts.
7963 Also implies COMMON.
7964 -1 indicates a bitwise operation; this makes a difference
7965 in the exact conditions for when it is safe to do the operation
7966 in a narrower mode. */
7967 int shorten = 0;
7968
7969 /* Nonzero if this is a comparison operation;
7970 if both args are promoted shorts, compare the original shorts.
7971 Also implies COMMON. */
7972 int short_compare = 0;
7973
7974 /* Nonzero if this is a right-shift operation, which can be computed on the
7975 original short and then promoted if the operand is a promoted short. */
7976 int short_shift = 0;
7977
7978 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7979 int common = 0;
7980
7981 /* True means types are compatible as far as ObjC is concerned. */
7982 bool objc_ok;
7983
7984 if (convert_p)
7985 {
7986 op0 = default_conversion (orig_op0);
7987 op1 = default_conversion (orig_op1);
7988 }
7989 else
7990 {
7991 op0 = orig_op0;
7992 op1 = orig_op1;
7993 }
7994
7995 type0 = TREE_TYPE (op0);
7996 type1 = TREE_TYPE (op1);
7997
7998 /* The expression codes of the data types of the arguments tell us
7999 whether the arguments are integers, floating, pointers, etc. */
8000 code0 = TREE_CODE (type0);
8001 code1 = TREE_CODE (type1);
8002
8003 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
8004 STRIP_TYPE_NOPS (op0);
8005 STRIP_TYPE_NOPS (op1);
8006
8007 /* If an error was already reported for one of the arguments,
8008 avoid reporting another error. */
8009
8010 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8011 return error_mark_node;
8012
8013 if ((invalid_op_diag
8014 = targetm.invalid_binary_op (code, type0, type1)))
8015 {
8016 error (invalid_op_diag);
8017 return error_mark_node;
8018 }
8019
8020 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
8021
8022 switch (code)
8023 {
8024 case PLUS_EXPR:
8025 /* Handle the pointer + int case. */
8026 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8027 return pointer_int_sum (PLUS_EXPR, op0, op1);
8028 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
8029 return pointer_int_sum (PLUS_EXPR, op1, op0);
8030 else
8031 common = 1;
8032 break;
8033
8034 case MINUS_EXPR:
8035 /* Subtraction of two similar pointers.
8036 We must subtract them as integers, then divide by object size. */
8037 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
8038 && comp_target_types (type0, type1))
8039 return pointer_diff (op0, op1);
8040 /* Handle pointer minus int. Just like pointer plus int. */
8041 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8042 return pointer_int_sum (MINUS_EXPR, op0, op1);
8043 else
8044 common = 1;
8045 break;
8046
8047 case MULT_EXPR:
8048 common = 1;
8049 break;
8050
8051 case TRUNC_DIV_EXPR:
8052 case CEIL_DIV_EXPR:
8053 case FLOOR_DIV_EXPR:
8054 case ROUND_DIV_EXPR:
8055 case EXACT_DIV_EXPR:
8056 warn_for_div_by_zero (op1);
8057
8058 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8059 || code0 == FIXED_POINT_TYPE
8060 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
8061 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8062 || code1 == FIXED_POINT_TYPE
8063 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
8064 {
8065 enum tree_code tcode0 = code0, tcode1 = code1;
8066
8067 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
8068 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
8069 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
8070 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
8071
8072 if (!((tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)
8073 || (tcode0 == FIXED_POINT_TYPE && tcode1 == FIXED_POINT_TYPE)))
8074 resultcode = RDIV_EXPR;
8075 else
8076 /* Although it would be tempting to shorten always here, that
8077 loses on some targets, since the modulo instruction is
8078 undefined if the quotient can't be represented in the
8079 computation mode. We shorten only if unsigned or if
8080 dividing by something we know != -1. */
8081 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
8082 || (TREE_CODE (op1) == INTEGER_CST
8083 && !integer_all_onesp (op1)));
8084 common = 1;
8085 }
8086 break;
8087
8088 case BIT_AND_EXPR:
8089 case BIT_IOR_EXPR:
8090 case BIT_XOR_EXPR:
8091 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8092 shorten = -1;
8093 /* Allow vector types which are not floating point types. */
8094 else if (code0 == VECTOR_TYPE
8095 && code1 == VECTOR_TYPE
8096 && !VECTOR_FLOAT_TYPE_P (type0)
8097 && !VECTOR_FLOAT_TYPE_P (type1))
8098 common = 1;
8099 break;
8100
8101 case TRUNC_MOD_EXPR:
8102 case FLOOR_MOD_EXPR:
8103 warn_for_div_by_zero (op1);
8104
8105 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8106 {
8107 /* Although it would be tempting to shorten always here, that loses
8108 on some targets, since the modulo instruction is undefined if the
8109 quotient can't be represented in the computation mode. We shorten
8110 only if unsigned or if dividing by something we know != -1. */
8111 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
8112 || (TREE_CODE (op1) == INTEGER_CST
8113 && !integer_all_onesp (op1)));
8114 common = 1;
8115 }
8116 break;
8117
8118 case TRUTH_ANDIF_EXPR:
8119 case TRUTH_ORIF_EXPR:
8120 case TRUTH_AND_EXPR:
8121 case TRUTH_OR_EXPR:
8122 case TRUTH_XOR_EXPR:
8123 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
8124 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8125 || code0 == FIXED_POINT_TYPE)
8126 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
8127 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8128 || code1 == FIXED_POINT_TYPE))
8129 {
8130 /* Result of these operations is always an int,
8131 but that does not mean the operands should be
8132 converted to ints! */
8133 result_type = integer_type_node;
8134 op0 = c_common_truthvalue_conversion (op0);
8135 op1 = c_common_truthvalue_conversion (op1);
8136 converted = 1;
8137 }
8138 break;
8139
8140 /* Shift operations: result has same type as first operand;
8141 always convert second operand to int.
8142 Also set SHORT_SHIFT if shifting rightward. */
8143
8144 case RSHIFT_EXPR:
8145 if ((code0 == INTEGER_TYPE || code0 == FIXED_POINT_TYPE)
8146 && code1 == INTEGER_TYPE)
8147 {
8148 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8149 {
8150 if (tree_int_cst_sgn (op1) < 0)
8151 warning (0, "right shift count is negative");
8152 else
8153 {
8154 if (!integer_zerop (op1))
8155 short_shift = 1;
8156
8157 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8158 warning (0, "right shift count >= width of type");
8159 }
8160 }
8161
8162 /* Use the type of the value to be shifted. */
8163 result_type = type0;
8164 /* Convert the shift-count to an integer, regardless of size
8165 of value being shifted. */
8166 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8167 op1 = convert (integer_type_node, op1);
8168 /* Avoid converting op1 to result_type later. */
8169 converted = 1;
8170 }
8171 break;
8172
8173 case LSHIFT_EXPR:
8174 if ((code0 == INTEGER_TYPE || code0 == FIXED_POINT_TYPE)
8175 && code1 == INTEGER_TYPE)
8176 {
8177 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8178 {
8179 if (tree_int_cst_sgn (op1) < 0)
8180 warning (0, "left shift count is negative");
8181
8182 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8183 warning (0, "left shift count >= width of type");
8184 }
8185
8186 /* Use the type of the value to be shifted. */
8187 result_type = type0;
8188 /* Convert the shift-count to an integer, regardless of size
8189 of value being shifted. */
8190 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8191 op1 = convert (integer_type_node, op1);
8192 /* Avoid converting op1 to result_type later. */
8193 converted = 1;
8194 }
8195 break;
8196
8197 case EQ_EXPR:
8198 case NE_EXPR:
8199 if (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1))
8200 warning (OPT_Wfloat_equal,
8201 "comparing floating point with == or != is unsafe");
8202 /* Result of comparison is always int,
8203 but don't convert the args to int! */
8204 build_type = integer_type_node;
8205 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8206 || code0 == FIXED_POINT_TYPE || code0 == COMPLEX_TYPE)
8207 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8208 || code1 == FIXED_POINT_TYPE || code1 == COMPLEX_TYPE))
8209 short_compare = 1;
8210 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8211 {
8212 tree tt0 = TREE_TYPE (type0);
8213 tree tt1 = TREE_TYPE (type1);
8214 /* Anything compares with void *. void * compares with anything.
8215 Otherwise, the targets must be compatible
8216 and both must be object or both incomplete. */
8217 if (comp_target_types (type0, type1))
8218 result_type = common_pointer_type (type0, type1);
8219 else if (VOID_TYPE_P (tt0))
8220 {
8221 /* op0 != orig_op0 detects the case of something
8222 whose value is 0 but which isn't a valid null ptr const. */
8223 if (pedantic && !null_pointer_constant_p (orig_op0)
8224 && TREE_CODE (tt1) == FUNCTION_TYPE)
8225 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
8226 "comparison of %<void *%> with function pointer");
8227 }
8228 else if (VOID_TYPE_P (tt1))
8229 {
8230 if (pedantic && !null_pointer_constant_p (orig_op1)
8231 && TREE_CODE (tt0) == FUNCTION_TYPE)
8232 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
8233 "comparison of %<void *%> with function pointer");
8234 }
8235 else
8236 /* Avoid warning about the volatile ObjC EH puts on decls. */
8237 if (!objc_ok)
8238 pedwarn (input_location, 0,
8239 "comparison of distinct pointer types lacks a cast");
8240
8241 if (result_type == NULL_TREE)
8242 result_type = ptr_type_node;
8243 }
8244 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8245 {
8246 if (TREE_CODE (op0) == ADDR_EXPR
8247 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
8248 warning (OPT_Waddress, "the address of %qD will never be NULL",
8249 TREE_OPERAND (op0, 0));
8250 result_type = type0;
8251 }
8252 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8253 {
8254 if (TREE_CODE (op1) == ADDR_EXPR
8255 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
8256 warning (OPT_Waddress, "the address of %qD will never be NULL",
8257 TREE_OPERAND (op1, 0));
8258 result_type = type1;
8259 }
8260 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8261 {
8262 result_type = type0;
8263 pedwarn (input_location, 0, "comparison between pointer and integer");
8264 }
8265 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8266 {
8267 result_type = type1;
8268 pedwarn (input_location, 0, "comparison between pointer and integer");
8269 }
8270 break;
8271
8272 case LE_EXPR:
8273 case GE_EXPR:
8274 case LT_EXPR:
8275 case GT_EXPR:
8276 build_type = integer_type_node;
8277 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8278 || code0 == FIXED_POINT_TYPE)
8279 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8280 || code1 == FIXED_POINT_TYPE))
8281 short_compare = 1;
8282 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8283 {
8284 if (comp_target_types (type0, type1))
8285 {
8286 result_type = common_pointer_type (type0, type1);
8287 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8288 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8289 pedwarn (input_location, 0,
8290 "comparison of complete and incomplete pointers");
8291 else if (TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8292 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
8293 "ordered comparisons of pointers to functions");
8294 }
8295 else
8296 {
8297 result_type = ptr_type_node;
8298 pedwarn (input_location, 0,
8299 "comparison of distinct pointer types lacks a cast");
8300 }
8301 }
8302 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8303 {
8304 result_type = type0;
8305 if (pedantic)
8306 pedwarn (input_location, OPT_pedantic,
8307 "ordered comparison of pointer with integer zero");
8308 else if (extra_warnings)
8309 warning (OPT_Wextra,
8310 "ordered comparison of pointer with integer zero");
8311 }
8312 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8313 {
8314 result_type = type1;
8315 pedwarn (input_location, OPT_pedantic,
8316 "ordered comparison of pointer with integer zero");
8317 }
8318 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8319 {
8320 result_type = type0;
8321 pedwarn (input_location, 0, "comparison between pointer and integer");
8322 }
8323 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8324 {
8325 result_type = type1;
8326 pedwarn (input_location, 0, "comparison between pointer and integer");
8327 }
8328 break;
8329
8330 default:
8331 gcc_unreachable ();
8332 }
8333
8334 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8335 return error_mark_node;
8336
8337 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8338 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8339 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8340 TREE_TYPE (type1))))
8341 {
8342 binary_op_error (code, type0, type1);
8343 return error_mark_node;
8344 }
8345
8346 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8347 || code0 == FIXED_POINT_TYPE || code0 == VECTOR_TYPE)
8348 &&
8349 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8350 || code1 == FIXED_POINT_TYPE || code1 == VECTOR_TYPE))
8351 {
8352 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8353
8354 if (shorten || common || short_compare)
8355 {
8356 result_type = c_common_type (type0, type1);
8357 if (result_type == error_mark_node)
8358 return error_mark_node;
8359 }
8360
8361 /* For certain operations (which identify themselves by shorten != 0)
8362 if both args were extended from the same smaller type,
8363 do the arithmetic in that type and then extend.
8364
8365 shorten !=0 and !=1 indicates a bitwise operation.
8366 For them, this optimization is safe only if
8367 both args are zero-extended or both are sign-extended.
8368 Otherwise, we might change the result.
8369 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8370 but calculated in (unsigned short) it would be (unsigned short)-1. */
8371
8372 if (shorten && none_complex)
8373 {
8374 final_type = result_type;
8375 result_type = shorten_binary_op (result_type, op0, op1,
8376 shorten == -1);
8377 }
8378
8379 /* Shifts can be shortened if shifting right. */
8380
8381 if (short_shift)
8382 {
8383 int unsigned_arg;
8384 tree arg0 = get_narrower (op0, &unsigned_arg);
8385
8386 final_type = result_type;
8387
8388 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8389 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8390
8391 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8392 /* We can shorten only if the shift count is less than the
8393 number of bits in the smaller type size. */
8394 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8395 /* We cannot drop an unsigned shift after sign-extension. */
8396 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8397 {
8398 /* Do an unsigned shift if the operand was zero-extended. */
8399 result_type
8400 = c_common_signed_or_unsigned_type (unsigned_arg,
8401 TREE_TYPE (arg0));
8402 /* Convert value-to-be-shifted to that type. */
8403 if (TREE_TYPE (op0) != result_type)
8404 op0 = convert (result_type, op0);
8405 converted = 1;
8406 }
8407 }
8408
8409 /* Comparison operations are shortened too but differently.
8410 They identify themselves by setting short_compare = 1. */
8411
8412 if (short_compare)
8413 {
8414 /* Don't write &op0, etc., because that would prevent op0
8415 from being kept in a register.
8416 Instead, make copies of the our local variables and
8417 pass the copies by reference, then copy them back afterward. */
8418 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8419 enum tree_code xresultcode = resultcode;
8420 tree val
8421 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8422
8423 if (val != 0)
8424 return val;
8425
8426 op0 = xop0, op1 = xop1;
8427 converted = 1;
8428 resultcode = xresultcode;
8429
8430 if (warn_sign_compare && !skip_evaluation)
8431 {
8432 warn_for_sign_compare (orig_op0, orig_op1, op0, op1,
8433 result_type, resultcode);
8434 }
8435 }
8436 }
8437
8438 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8439 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8440 Then the expression will be built.
8441 It will be given type FINAL_TYPE if that is nonzero;
8442 otherwise, it will be given type RESULT_TYPE. */
8443
8444 if (!result_type)
8445 {
8446 binary_op_error (code, TREE_TYPE (op0), TREE_TYPE (op1));
8447 return error_mark_node;
8448 }
8449
8450 if (!converted)
8451 {
8452 if (TREE_TYPE (op0) != result_type)
8453 op0 = convert_and_check (result_type, op0);
8454 if (TREE_TYPE (op1) != result_type)
8455 op1 = convert_and_check (result_type, op1);
8456
8457 /* This can happen if one operand has a vector type, and the other
8458 has a different type. */
8459 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8460 return error_mark_node;
8461 }
8462
8463 if (build_type == NULL_TREE)
8464 build_type = result_type;
8465
8466 {
8467 /* Treat expressions in initializers specially as they can't trap. */
8468 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8469 build_type,
8470 op0, op1)
8471 : fold_build2 (resultcode, build_type,
8472 op0, op1);
8473
8474 if (final_type != 0)
8475 result = convert (final_type, result);
8476 return result;
8477 }
8478 }
8479
8480
8481 /* Convert EXPR to be a truth-value, validating its type for this
8482 purpose. */
8483
8484 tree
8485 c_objc_common_truthvalue_conversion (tree expr)
8486 {
8487 switch (TREE_CODE (TREE_TYPE (expr)))
8488 {
8489 case ARRAY_TYPE:
8490 error ("used array that cannot be converted to pointer where scalar is required");
8491 return error_mark_node;
8492
8493 case RECORD_TYPE:
8494 error ("used struct type value where scalar is required");
8495 return error_mark_node;
8496
8497 case UNION_TYPE:
8498 error ("used union type value where scalar is required");
8499 return error_mark_node;
8500
8501 case FUNCTION_TYPE:
8502 gcc_unreachable ();
8503
8504 default:
8505 break;
8506 }
8507
8508 /* ??? Should we also give an error for void and vectors rather than
8509 leaving those to give errors later? */
8510 return c_common_truthvalue_conversion (expr);
8511 }
8512 \f
8513
8514 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8515 required. */
8516
8517 tree
8518 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se)
8519 {
8520 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8521 {
8522 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8523 /* Executing a compound literal inside a function reinitializes
8524 it. */
8525 if (!TREE_STATIC (decl))
8526 *se = true;
8527 return decl;
8528 }
8529 else
8530 return expr;
8531 }
8532 \f
8533 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8534
8535 tree
8536 c_begin_omp_parallel (void)
8537 {
8538 tree block;
8539
8540 keep_next_level ();
8541 block = c_begin_compound_stmt (true);
8542
8543 return block;
8544 }
8545
8546 /* Generate OMP_PARALLEL, with CLAUSES and BLOCK as its compound statement. */
8547
8548 tree
8549 c_finish_omp_parallel (tree clauses, tree block)
8550 {
8551 tree stmt;
8552
8553 block = c_end_compound_stmt (block, true);
8554
8555 stmt = make_node (OMP_PARALLEL);
8556 TREE_TYPE (stmt) = void_type_node;
8557 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8558 OMP_PARALLEL_BODY (stmt) = block;
8559
8560 return add_stmt (stmt);
8561 }
8562
8563 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8564
8565 tree
8566 c_begin_omp_task (void)
8567 {
8568 tree block;
8569
8570 keep_next_level ();
8571 block = c_begin_compound_stmt (true);
8572
8573 return block;
8574 }
8575
8576 /* Generate OMP_TASK, with CLAUSES and BLOCK as its compound statement. */
8577
8578 tree
8579 c_finish_omp_task (tree clauses, tree block)
8580 {
8581 tree stmt;
8582
8583 block = c_end_compound_stmt (block, true);
8584
8585 stmt = make_node (OMP_TASK);
8586 TREE_TYPE (stmt) = void_type_node;
8587 OMP_TASK_CLAUSES (stmt) = clauses;
8588 OMP_TASK_BODY (stmt) = block;
8589
8590 return add_stmt (stmt);
8591 }
8592
8593 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8594 Remove any elements from the list that are invalid. */
8595
8596 tree
8597 c_finish_omp_clauses (tree clauses)
8598 {
8599 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8600 tree c, t, *pc = &clauses;
8601 const char *name;
8602
8603 bitmap_obstack_initialize (NULL);
8604 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8605 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8606 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8607
8608 for (pc = &clauses, c = clauses; c ; c = *pc)
8609 {
8610 bool remove = false;
8611 bool need_complete = false;
8612 bool need_implicitly_determined = false;
8613
8614 switch (OMP_CLAUSE_CODE (c))
8615 {
8616 case OMP_CLAUSE_SHARED:
8617 name = "shared";
8618 need_implicitly_determined = true;
8619 goto check_dup_generic;
8620
8621 case OMP_CLAUSE_PRIVATE:
8622 name = "private";
8623 need_complete = true;
8624 need_implicitly_determined = true;
8625 goto check_dup_generic;
8626
8627 case OMP_CLAUSE_REDUCTION:
8628 name = "reduction";
8629 need_implicitly_determined = true;
8630 t = OMP_CLAUSE_DECL (c);
8631 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8632 || POINTER_TYPE_P (TREE_TYPE (t)))
8633 {
8634 error ("%qE has invalid type for %<reduction%>", t);
8635 remove = true;
8636 }
8637 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8638 {
8639 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8640 const char *r_name = NULL;
8641
8642 switch (r_code)
8643 {
8644 case PLUS_EXPR:
8645 case MULT_EXPR:
8646 case MINUS_EXPR:
8647 break;
8648 case BIT_AND_EXPR:
8649 r_name = "&";
8650 break;
8651 case BIT_XOR_EXPR:
8652 r_name = "^";
8653 break;
8654 case BIT_IOR_EXPR:
8655 r_name = "|";
8656 break;
8657 case TRUTH_ANDIF_EXPR:
8658 r_name = "&&";
8659 break;
8660 case TRUTH_ORIF_EXPR:
8661 r_name = "||";
8662 break;
8663 default:
8664 gcc_unreachable ();
8665 }
8666 if (r_name)
8667 {
8668 error ("%qE has invalid type for %<reduction(%s)%>",
8669 t, r_name);
8670 remove = true;
8671 }
8672 }
8673 goto check_dup_generic;
8674
8675 case OMP_CLAUSE_COPYPRIVATE:
8676 name = "copyprivate";
8677 goto check_dup_generic;
8678
8679 case OMP_CLAUSE_COPYIN:
8680 name = "copyin";
8681 t = OMP_CLAUSE_DECL (c);
8682 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8683 {
8684 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8685 remove = true;
8686 }
8687 goto check_dup_generic;
8688
8689 check_dup_generic:
8690 t = OMP_CLAUSE_DECL (c);
8691 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8692 {
8693 error ("%qE is not a variable in clause %qs", t, name);
8694 remove = true;
8695 }
8696 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8697 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8698 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8699 {
8700 error ("%qE appears more than once in data clauses", t);
8701 remove = true;
8702 }
8703 else
8704 bitmap_set_bit (&generic_head, DECL_UID (t));
8705 break;
8706
8707 case OMP_CLAUSE_FIRSTPRIVATE:
8708 name = "firstprivate";
8709 t = OMP_CLAUSE_DECL (c);
8710 need_complete = true;
8711 need_implicitly_determined = true;
8712 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8713 {
8714 error ("%qE is not a variable in clause %<firstprivate%>", t);
8715 remove = true;
8716 }
8717 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8718 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8719 {
8720 error ("%qE appears more than once in data clauses", t);
8721 remove = true;
8722 }
8723 else
8724 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8725 break;
8726
8727 case OMP_CLAUSE_LASTPRIVATE:
8728 name = "lastprivate";
8729 t = OMP_CLAUSE_DECL (c);
8730 need_complete = true;
8731 need_implicitly_determined = true;
8732 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8733 {
8734 error ("%qE is not a variable in clause %<lastprivate%>", t);
8735 remove = true;
8736 }
8737 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8738 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8739 {
8740 error ("%qE appears more than once in data clauses", t);
8741 remove = true;
8742 }
8743 else
8744 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8745 break;
8746
8747 case OMP_CLAUSE_IF:
8748 case OMP_CLAUSE_NUM_THREADS:
8749 case OMP_CLAUSE_SCHEDULE:
8750 case OMP_CLAUSE_NOWAIT:
8751 case OMP_CLAUSE_ORDERED:
8752 case OMP_CLAUSE_DEFAULT:
8753 case OMP_CLAUSE_UNTIED:
8754 case OMP_CLAUSE_COLLAPSE:
8755 pc = &OMP_CLAUSE_CHAIN (c);
8756 continue;
8757
8758 default:
8759 gcc_unreachable ();
8760 }
8761
8762 if (!remove)
8763 {
8764 t = OMP_CLAUSE_DECL (c);
8765
8766 if (need_complete)
8767 {
8768 t = require_complete_type (t);
8769 if (t == error_mark_node)
8770 remove = true;
8771 }
8772
8773 if (need_implicitly_determined)
8774 {
8775 const char *share_name = NULL;
8776
8777 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8778 share_name = "threadprivate";
8779 else switch (c_omp_predetermined_sharing (t))
8780 {
8781 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8782 break;
8783 case OMP_CLAUSE_DEFAULT_SHARED:
8784 share_name = "shared";
8785 break;
8786 case OMP_CLAUSE_DEFAULT_PRIVATE:
8787 share_name = "private";
8788 break;
8789 default:
8790 gcc_unreachable ();
8791 }
8792 if (share_name)
8793 {
8794 error ("%qE is predetermined %qs for %qs",
8795 t, share_name, name);
8796 remove = true;
8797 }
8798 }
8799 }
8800
8801 if (remove)
8802 *pc = OMP_CLAUSE_CHAIN (c);
8803 else
8804 pc = &OMP_CLAUSE_CHAIN (c);
8805 }
8806
8807 bitmap_obstack_release (NULL);
8808 return clauses;
8809 }
8810
8811 /* Make a variant type in the proper way for C/C++, propagating qualifiers
8812 down to the element type of an array. */
8813
8814 tree
8815 c_build_qualified_type (tree type, int type_quals)
8816 {
8817 if (type == error_mark_node)
8818 return type;
8819
8820 if (TREE_CODE (type) == ARRAY_TYPE)
8821 {
8822 tree t;
8823 tree element_type = c_build_qualified_type (TREE_TYPE (type),
8824 type_quals);
8825
8826 /* See if we already have an identically qualified type. */
8827 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
8828 {
8829 if (TYPE_QUALS (strip_array_types (t)) == type_quals
8830 && TYPE_NAME (t) == TYPE_NAME (type)
8831 && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
8832 && attribute_list_equal (TYPE_ATTRIBUTES (t),
8833 TYPE_ATTRIBUTES (type)))
8834 break;
8835 }
8836 if (!t)
8837 {
8838 tree domain = TYPE_DOMAIN (type);
8839
8840 t = build_variant_type_copy (type);
8841 TREE_TYPE (t) = element_type;
8842
8843 if (TYPE_STRUCTURAL_EQUALITY_P (element_type)
8844 || (domain && TYPE_STRUCTURAL_EQUALITY_P (domain)))
8845 SET_TYPE_STRUCTURAL_EQUALITY (t);
8846 else if (TYPE_CANONICAL (element_type) != element_type
8847 || (domain && TYPE_CANONICAL (domain) != domain))
8848 {
8849 tree unqualified_canon
8850 = build_array_type (TYPE_CANONICAL (element_type),
8851 domain? TYPE_CANONICAL (domain)
8852 : NULL_TREE);
8853 TYPE_CANONICAL (t)
8854 = c_build_qualified_type (unqualified_canon, type_quals);
8855 }
8856 else
8857 TYPE_CANONICAL (t) = t;
8858 }
8859 return t;
8860 }
8861
8862 /* A restrict-qualified pointer type must be a pointer to object or
8863 incomplete type. Note that the use of POINTER_TYPE_P also allows
8864 REFERENCE_TYPEs, which is appropriate for C++. */
8865 if ((type_quals & TYPE_QUAL_RESTRICT)
8866 && (!POINTER_TYPE_P (type)
8867 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
8868 {
8869 error ("invalid use of %<restrict%>");
8870 type_quals &= ~TYPE_QUAL_RESTRICT;
8871 }
8872
8873 return build_qualified_type (type, type_quals);
8874 }
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