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* doc/loop.texi: Document possibility not to perform disambiguation
[official-gcc.git] / gcc / c-typeck.c
blob66b109ecf3ea86754b3564a5d0929b850233effe
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
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 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
22
23
24 /* This file is part of the C front end.
25 It contains routines to build C expressions given their operands,
26 including computing the types of the result, C-specific error checks,
27 and some optimization. */
28
29 #include "config.h"
30 #include "system.h"
31 #include "coretypes.h"
32 #include "tm.h"
33 #include "rtl.h"
34 #include "tree.h"
35 #include "langhooks.h"
36 #include "c-tree.h"
37 #include "tm_p.h"
38 #include "flags.h"
39 #include "output.h"
40 #include "expr.h"
41 #include "toplev.h"
42 #include "intl.h"
43 #include "ggc.h"
44 #include "target.h"
45 #include "tree-iterator.h"
46 #include "tree-gimple.h"
47 #include "tree-flow.h"
48
49 /* Possible cases of implicit bad conversions. Used to select
50 diagnostic messages in convert_for_assignment. */
51 enum impl_conv {
52 ic_argpass,
53 ic_argpass_nonproto,
54 ic_assign,
55 ic_init,
56 ic_return
57 };
58
59 /* The level of nesting inside "__alignof__". */
60 int in_alignof;
61
62 /* The level of nesting inside "sizeof". */
63 int in_sizeof;
64
65 /* The level of nesting inside "typeof". */
66 int in_typeof;
67
68 struct c_label_context_se *label_context_stack_se;
69 struct c_label_context_vm *label_context_stack_vm;
70
71 /* Nonzero if we've already printed a "missing braces around initializer"
72 message within this initializer. */
73 static int missing_braces_mentioned;
74
75 static int require_constant_value;
76 static int require_constant_elements;
77
78 static bool null_pointer_constant_p (tree);
79 static tree qualify_type (tree, tree);
80 static int tagged_types_tu_compatible_p (tree, tree);
81 static int comp_target_types (tree, tree);
82 static int function_types_compatible_p (tree, tree);
83 static int type_lists_compatible_p (tree, tree);
84 static tree decl_constant_value_for_broken_optimization (tree);
85 static tree lookup_field (tree, tree);
86 static tree convert_arguments (tree, tree, tree, tree);
87 static tree pointer_diff (tree, tree);
88 static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree,
89 int);
90 static tree valid_compound_expr_initializer (tree, tree);
91 static void push_string (const char *);
92 static void push_member_name (tree);
93 static int spelling_length (void);
94 static char *print_spelling (char *);
95 static void warning_init (const char *);
96 static tree digest_init (tree, tree, bool, int);
97 static void output_init_element (tree, bool, tree, tree, int);
98 static void output_pending_init_elements (int);
99 static int set_designator (int);
100 static void push_range_stack (tree);
101 static void add_pending_init (tree, tree);
102 static void set_nonincremental_init (void);
103 static void set_nonincremental_init_from_string (tree);
104 static tree find_init_member (tree);
105 static void readonly_error (tree, enum lvalue_use);
106 static int lvalue_or_else (tree, enum lvalue_use);
107 static int lvalue_p (tree);
108 static void record_maybe_used_decl (tree);
109 static int comptypes_internal (tree, tree);
110 \f
111 /* Return true if EXP is a null pointer constant, false otherwise. */
112
113 static bool
114 null_pointer_constant_p (tree expr)
115 {
116 /* This should really operate on c_expr structures, but they aren't
117 yet available everywhere required. */
118 tree type = TREE_TYPE (expr);
119 return (TREE_CODE (expr) == INTEGER_CST
120 && !TREE_OVERFLOW (expr)
121 && integer_zerop (expr)
122 && (INTEGRAL_TYPE_P (type)
123 || (TREE_CODE (type) == POINTER_TYPE
124 && VOID_TYPE_P (TREE_TYPE (type))
125 && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED)));
126 }
127 \f/* This is a cache to hold if two types are compatible or not. */
128
129 struct tagged_tu_seen_cache {
130 const struct tagged_tu_seen_cache * next;
131 tree t1;
132 tree t2;
133 /* The return value of tagged_types_tu_compatible_p if we had seen
134 these two types already. */
135 int val;
136 };
137
138 static const struct tagged_tu_seen_cache * tagged_tu_seen_base;
139 static void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *);
140
141 /* Do `exp = require_complete_type (exp);' to make sure exp
142 does not have an incomplete type. (That includes void types.) */
143
144 tree
145 require_complete_type (tree value)
146 {
147 tree type = TREE_TYPE (value);
148
149 if (value == error_mark_node || type == error_mark_node)
150 return error_mark_node;
151
152 /* First, detect a valid value with a complete type. */
153 if (COMPLETE_TYPE_P (type))
154 return value;
155
156 c_incomplete_type_error (value, type);
157 return error_mark_node;
158 }
159
160 /* Print an error message for invalid use of an incomplete type.
161 VALUE is the expression that was used (or 0 if that isn't known)
162 and TYPE is the type that was invalid. */
163
164 void
165 c_incomplete_type_error (tree value, tree type)
166 {
167 const char *type_code_string;
168
169 /* Avoid duplicate error message. */
170 if (TREE_CODE (type) == ERROR_MARK)
171 return;
172
173 if (value != 0 && (TREE_CODE (value) == VAR_DECL
174 || TREE_CODE (value) == PARM_DECL))
175 error ("%qD has an incomplete type", value);
176 else
177 {
178 retry:
179 /* We must print an error message. Be clever about what it says. */
180
181 switch (TREE_CODE (type))
182 {
183 case RECORD_TYPE:
184 type_code_string = "struct";
185 break;
186
187 case UNION_TYPE:
188 type_code_string = "union";
189 break;
190
191 case ENUMERAL_TYPE:
192 type_code_string = "enum";
193 break;
194
195 case VOID_TYPE:
196 error ("invalid use of void expression");
197 return;
198
199 case ARRAY_TYPE:
200 if (TYPE_DOMAIN (type))
201 {
202 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
203 {
204 error ("invalid use of flexible array member");
205 return;
206 }
207 type = TREE_TYPE (type);
208 goto retry;
209 }
210 error ("invalid use of array with unspecified bounds");
211 return;
212
213 default:
214 gcc_unreachable ();
215 }
216
217 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
218 error ("invalid use of undefined type %<%s %E%>",
219 type_code_string, TYPE_NAME (type));
220 else
221 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
222 error ("invalid use of incomplete typedef %qD", TYPE_NAME (type));
223 }
224 }
225
226 /* Given a type, apply default promotions wrt unnamed function
227 arguments and return the new type. */
228
229 tree
230 c_type_promotes_to (tree type)
231 {
232 if (TYPE_MAIN_VARIANT (type) == float_type_node)
233 return double_type_node;
234
235 if (c_promoting_integer_type_p (type))
236 {
237 /* Preserve unsignedness if not really getting any wider. */
238 if (TYPE_UNSIGNED (type)
239 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
240 return unsigned_type_node;
241 return integer_type_node;
242 }
243
244 return type;
245 }
246
247 /* Return a variant of TYPE which has all the type qualifiers of LIKE
248 as well as those of TYPE. */
249
250 static tree
251 qualify_type (tree type, tree like)
252 {
253 return c_build_qualified_type (type,
254 TYPE_QUALS (type) | TYPE_QUALS (like));
255 }
256
257 /* Return true iff the given tree T is a variable length array. */
258
259 bool
260 c_vla_type_p (tree t)
261 {
262 if (TREE_CODE (t) == ARRAY_TYPE
263 && C_TYPE_VARIABLE_SIZE (t))
264 return true;
265 return false;
266 }
267 \f
268 /* Return the composite type of two compatible types.
269
270 We assume that comptypes has already been done and returned
271 nonzero; if that isn't so, this may crash. In particular, we
272 assume that qualifiers match. */
273
274 tree
275 composite_type (tree t1, tree t2)
276 {
277 enum tree_code code1;
278 enum tree_code code2;
279 tree attributes;
280
281 /* Save time if the two types are the same. */
282
283 if (t1 == t2) return t1;
284
285 /* If one type is nonsense, use the other. */
286 if (t1 == error_mark_node)
287 return t2;
288 if (t2 == error_mark_node)
289 return t1;
290
291 code1 = TREE_CODE (t1);
292 code2 = TREE_CODE (t2);
293
294 /* Merge the attributes. */
295 attributes = targetm.merge_type_attributes (t1, t2);
296
297 /* If one is an enumerated type and the other is the compatible
298 integer type, the composite type might be either of the two
299 (DR#013 question 3). For consistency, use the enumerated type as
300 the composite type. */
301
302 if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE)
303 return t1;
304 if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE)
305 return t2;
306
307 gcc_assert (code1 == code2);
308
309 switch (code1)
310 {
311 case POINTER_TYPE:
312 /* For two pointers, do this recursively on the target type. */
313 {
314 tree pointed_to_1 = TREE_TYPE (t1);
315 tree pointed_to_2 = TREE_TYPE (t2);
316 tree target = composite_type (pointed_to_1, pointed_to_2);
317 t1 = build_pointer_type (target);
318 t1 = build_type_attribute_variant (t1, attributes);
319 return qualify_type (t1, t2);
320 }
321
322 case ARRAY_TYPE:
323 {
324 tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
325 int quals;
326 tree unqual_elt;
327 tree d1 = TYPE_DOMAIN (t1);
328 tree d2 = TYPE_DOMAIN (t2);
329 bool d1_variable, d2_variable;
330 bool d1_zero, d2_zero;
331
332 /* We should not have any type quals on arrays at all. */
333 gcc_assert (!TYPE_QUALS (t1) && !TYPE_QUALS (t2));
334
335 d1_zero = d1 == 0 || !TYPE_MAX_VALUE (d1);
336 d2_zero = d2 == 0 || !TYPE_MAX_VALUE (d2);
337
338 d1_variable = (!d1_zero
339 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
340 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
341 d2_variable = (!d2_zero
342 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
343 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
344 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
345 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
346
347 /* Save space: see if the result is identical to one of the args. */
348 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)
349 && (d2_variable || d2_zero || !d1_variable))
350 return build_type_attribute_variant (t1, attributes);
351 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)
352 && (d1_variable || d1_zero || !d2_variable))
353 return build_type_attribute_variant (t2, attributes);
354
355 if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
356 return build_type_attribute_variant (t1, attributes);
357 if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
358 return build_type_attribute_variant (t2, attributes);
359
360 /* Merge the element types, and have a size if either arg has
361 one. We may have qualifiers on the element types. To set
362 up TYPE_MAIN_VARIANT correctly, we need to form the
363 composite of the unqualified types and add the qualifiers
364 back at the end. */
365 quals = TYPE_QUALS (strip_array_types (elt));
366 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
367 t1 = build_array_type (unqual_elt,
368 TYPE_DOMAIN ((TYPE_DOMAIN (t1)
369 && (d2_variable
370 || d2_zero
371 || !d1_variable))
372 ? t1
373 : t2));
374 t1 = c_build_qualified_type (t1, quals);
375 return build_type_attribute_variant (t1, attributes);
376 }
377
378 case ENUMERAL_TYPE:
379 case RECORD_TYPE:
380 case UNION_TYPE:
381 if (attributes != NULL)
382 {
383 /* Try harder not to create a new aggregate type. */
384 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
385 return t1;
386 if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
387 return t2;
388 }
389 return build_type_attribute_variant (t1, attributes);
390
391 case FUNCTION_TYPE:
392 /* Function types: prefer the one that specified arg types.
393 If both do, merge the arg types. Also merge the return types. */
394 {
395 tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
396 tree p1 = TYPE_ARG_TYPES (t1);
397 tree p2 = TYPE_ARG_TYPES (t2);
398 int len;
399 tree newargs, n;
400 int i;
401
402 /* Save space: see if the result is identical to one of the args. */
403 if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2))
404 return build_type_attribute_variant (t1, attributes);
405 if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1))
406 return build_type_attribute_variant (t2, attributes);
407
408 /* Simple way if one arg fails to specify argument types. */
409 if (TYPE_ARG_TYPES (t1) == 0)
410 {
411 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
412 t1 = build_type_attribute_variant (t1, attributes);
413 return qualify_type (t1, t2);
414 }
415 if (TYPE_ARG_TYPES (t2) == 0)
416 {
417 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
418 t1 = build_type_attribute_variant (t1, attributes);
419 return qualify_type (t1, t2);
420 }
421
422 /* If both args specify argument types, we must merge the two
423 lists, argument by argument. */
424 /* Tell global_bindings_p to return false so that variable_size
425 doesn't die on VLAs in parameter types. */
426 c_override_global_bindings_to_false = true;
427
428 len = list_length (p1);
429 newargs = 0;
430
431 for (i = 0; i < len; i++)
432 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
433
434 n = newargs;
435
436 for (; p1;
437 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
438 {
439 /* A null type means arg type is not specified.
440 Take whatever the other function type has. */
441 if (TREE_VALUE (p1) == 0)
442 {
443 TREE_VALUE (n) = TREE_VALUE (p2);
444 goto parm_done;
445 }
446 if (TREE_VALUE (p2) == 0)
447 {
448 TREE_VALUE (n) = TREE_VALUE (p1);
449 goto parm_done;
450 }
451
452 /* Given wait (union {union wait *u; int *i} *)
453 and wait (union wait *),
454 prefer union wait * as type of parm. */
455 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
456 && TREE_VALUE (p1) != TREE_VALUE (p2))
457 {
458 tree memb;
459 tree mv2 = TREE_VALUE (p2);
460 if (mv2 && mv2 != error_mark_node
461 && TREE_CODE (mv2) != ARRAY_TYPE)
462 mv2 = TYPE_MAIN_VARIANT (mv2);
463 for (memb = TYPE_FIELDS (TREE_VALUE (p1));
464 memb; memb = TREE_CHAIN (memb))
465 {
466 tree mv3 = TREE_TYPE (memb);
467 if (mv3 && mv3 != error_mark_node
468 && TREE_CODE (mv3) != ARRAY_TYPE)
469 mv3 = TYPE_MAIN_VARIANT (mv3);
470 if (comptypes (mv3, mv2))
471 {
472 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
473 TREE_VALUE (p2));
474 if (pedantic)
475 pedwarn ("function types not truly compatible in ISO C");
476 goto parm_done;
477 }
478 }
479 }
480 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
481 && TREE_VALUE (p2) != TREE_VALUE (p1))
482 {
483 tree memb;
484 tree mv1 = TREE_VALUE (p1);
485 if (mv1 && mv1 != error_mark_node
486 && TREE_CODE (mv1) != ARRAY_TYPE)
487 mv1 = TYPE_MAIN_VARIANT (mv1);
488 for (memb = TYPE_FIELDS (TREE_VALUE (p2));
489 memb; memb = TREE_CHAIN (memb))
490 {
491 tree mv3 = TREE_TYPE (memb);
492 if (mv3 && mv3 != error_mark_node
493 && TREE_CODE (mv3) != ARRAY_TYPE)
494 mv3 = TYPE_MAIN_VARIANT (mv3);
495 if (comptypes (mv3, mv1))
496 {
497 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
498 TREE_VALUE (p1));
499 if (pedantic)
500 pedwarn ("function types not truly compatible in ISO C");
501 goto parm_done;
502 }
503 }
504 }
505 TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2));
506 parm_done: ;
507 }
508
509 c_override_global_bindings_to_false = false;
510 t1 = build_function_type (valtype, newargs);
511 t1 = qualify_type (t1, t2);
512 /* ... falls through ... */
513 }
514
515 default:
516 return build_type_attribute_variant (t1, attributes);
517 }
518
519 }
520
521 /* Return the type of a conditional expression between pointers to
522 possibly differently qualified versions of compatible types.
523
524 We assume that comp_target_types has already been done and returned
525 nonzero; if that isn't so, this may crash. */
526
527 static tree
528 common_pointer_type (tree t1, tree t2)
529 {
530 tree attributes;
531 tree pointed_to_1, mv1;
532 tree pointed_to_2, mv2;
533 tree target;
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 t1 = build_pointer_type (c_build_qualified_type
562 (target,
563 TYPE_QUALS (pointed_to_1) |
564 TYPE_QUALS (pointed_to_2)));
565 return build_type_attribute_variant (t1, attributes);
566 }
567
568 /* Return the common type for two arithmetic types under the usual
569 arithmetic conversions. The default conversions have already been
570 applied, and enumerated types converted to their compatible integer
571 types. The resulting type is unqualified and has no attributes.
572
573 This is the type for the result of most arithmetic operations
574 if the operands have the given two types. */
575
576 static tree
577 c_common_type (tree t1, tree t2)
578 {
579 enum tree_code code1;
580 enum tree_code code2;
581
582 /* If one type is nonsense, use the other. */
583 if (t1 == error_mark_node)
584 return t2;
585 if (t2 == error_mark_node)
586 return t1;
587
588 if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED)
589 t1 = TYPE_MAIN_VARIANT (t1);
590
591 if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED)
592 t2 = TYPE_MAIN_VARIANT (t2);
593
594 if (TYPE_ATTRIBUTES (t1) != NULL_TREE)
595 t1 = build_type_attribute_variant (t1, NULL_TREE);
596
597 if (TYPE_ATTRIBUTES (t2) != NULL_TREE)
598 t2 = build_type_attribute_variant (t2, NULL_TREE);
599
600 /* Save time if the two types are the same. */
601
602 if (t1 == t2) return t1;
603
604 code1 = TREE_CODE (t1);
605 code2 = TREE_CODE (t2);
606
607 gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE
608 || code1 == REAL_TYPE || code1 == INTEGER_TYPE);
609 gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE
610 || code2 == REAL_TYPE || code2 == INTEGER_TYPE);
611
612 /* When one operand is a decimal float type, the other operand cannot be
613 a generic float type or a complex type. We also disallow vector types
614 here. */
615 if ((DECIMAL_FLOAT_TYPE_P (t1) || DECIMAL_FLOAT_TYPE_P (t2))
616 && !(DECIMAL_FLOAT_TYPE_P (t1) && DECIMAL_FLOAT_TYPE_P (t2)))
617 {
618 if (code1 == VECTOR_TYPE || code2 == VECTOR_TYPE)
619 {
620 error ("can%'t mix operands of decimal float and vector types");
621 return error_mark_node;
622 }
623 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
624 {
625 error ("can%'t mix operands of decimal float and complex types");
626 return error_mark_node;
627 }
628 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
629 {
630 error ("can%'t mix operands of decimal float and other float types");
631 return error_mark_node;
632 }
633 }
634
635 /* If one type is a vector type, return that type. (How the usual
636 arithmetic conversions apply to the vector types extension is not
637 precisely specified.) */
638 if (code1 == VECTOR_TYPE)
639 return t1;
640
641 if (code2 == VECTOR_TYPE)
642 return t2;
643
644 /* If one type is complex, form the common type of the non-complex
645 components, then make that complex. Use T1 or T2 if it is the
646 required type. */
647 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
648 {
649 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
650 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
651 tree subtype = c_common_type (subtype1, subtype2);
652
653 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
654 return t1;
655 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
656 return t2;
657 else
658 return build_complex_type (subtype);
659 }
660
661 /* If only one is real, use it as the result. */
662
663 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
664 return t1;
665
666 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
667 return t2;
668
669 /* If both are real and either are decimal floating point types, use
670 the decimal floating point type with the greater precision. */
671
672 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
673 {
674 if (TYPE_MAIN_VARIANT (t1) == dfloat128_type_node
675 || TYPE_MAIN_VARIANT (t2) == dfloat128_type_node)
676 return dfloat128_type_node;
677 else if (TYPE_MAIN_VARIANT (t1) == dfloat64_type_node
678 || TYPE_MAIN_VARIANT (t2) == dfloat64_type_node)
679 return dfloat64_type_node;
680 else if (TYPE_MAIN_VARIANT (t1) == dfloat32_type_node
681 || TYPE_MAIN_VARIANT (t2) == dfloat32_type_node)
682 return dfloat32_type_node;
683 }
684
685 /* Both real or both integers; use the one with greater precision. */
686
687 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
688 return t1;
689 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
690 return t2;
691
692 /* Same precision. Prefer long longs to longs to ints when the
693 same precision, following the C99 rules on integer type rank
694 (which are equivalent to the C90 rules for C90 types). */
695
696 if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node
697 || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node)
698 return long_long_unsigned_type_node;
699
700 if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node
701 || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node)
702 {
703 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
704 return long_long_unsigned_type_node;
705 else
706 return long_long_integer_type_node;
707 }
708
709 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
710 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
711 return long_unsigned_type_node;
712
713 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
714 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
715 {
716 /* But preserve unsignedness from the other type,
717 since long cannot hold all the values of an unsigned int. */
718 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
719 return long_unsigned_type_node;
720 else
721 return long_integer_type_node;
722 }
723
724 /* Likewise, prefer long double to double even if same size. */
725 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
726 || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
727 return long_double_type_node;
728
729 /* Otherwise prefer the unsigned one. */
730
731 if (TYPE_UNSIGNED (t1))
732 return t1;
733 else
734 return t2;
735 }
736 \f
737 /* Wrapper around c_common_type that is used by c-common.c and other
738 front end optimizations that remove promotions. ENUMERAL_TYPEs
739 are allowed here and are converted to their compatible integer types.
740 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
741 preferably a non-Boolean type as the common type. */
742 tree
743 common_type (tree t1, tree t2)
744 {
745 if (TREE_CODE (t1) == ENUMERAL_TYPE)
746 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
747 if (TREE_CODE (t2) == ENUMERAL_TYPE)
748 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
749
750 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
751 if (TREE_CODE (t1) == BOOLEAN_TYPE
752 && TREE_CODE (t2) == BOOLEAN_TYPE)
753 return boolean_type_node;
754
755 /* If either type is BOOLEAN_TYPE, then return the other. */
756 if (TREE_CODE (t1) == BOOLEAN_TYPE)
757 return t2;
758 if (TREE_CODE (t2) == BOOLEAN_TYPE)
759 return t1;
760
761 return c_common_type (t1, t2);
762 }
763
764 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
765 or various other operations. Return 2 if they are compatible
766 but a warning may be needed if you use them together. */
767
768 int
769 comptypes (tree type1, tree type2)
770 {
771 const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base;
772 int val;
773
774 val = comptypes_internal (type1, type2);
775 free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1);
776
777 return val;
778 }
779 \f
780 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
781 or various other operations. Return 2 if they are compatible
782 but a warning may be needed if you use them together. This
783 differs from comptypes, in that we don't free the seen types. */
784
785 static int
786 comptypes_internal (tree type1, tree type2)
787 {
788 tree t1 = type1;
789 tree t2 = type2;
790 int attrval, val;
791
792 /* Suppress errors caused by previously reported errors. */
793
794 if (t1 == t2 || !t1 || !t2
795 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
796 return 1;
797
798 /* If either type is the internal version of sizetype, return the
799 language version. */
800 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
801 && TYPE_ORIG_SIZE_TYPE (t1))
802 t1 = TYPE_ORIG_SIZE_TYPE (t1);
803
804 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
805 && TYPE_ORIG_SIZE_TYPE (t2))
806 t2 = TYPE_ORIG_SIZE_TYPE (t2);
807
808
809 /* Enumerated types are compatible with integer types, but this is
810 not transitive: two enumerated types in the same translation unit
811 are compatible with each other only if they are the same type. */
812
813 if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE)
814 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1));
815 else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE)
816 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2));
817
818 if (t1 == t2)
819 return 1;
820
821 /* Different classes of types can't be compatible. */
822
823 if (TREE_CODE (t1) != TREE_CODE (t2))
824 return 0;
825
826 /* Qualifiers must match. C99 6.7.3p9 */
827
828 if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
829 return 0;
830
831 /* Allow for two different type nodes which have essentially the same
832 definition. Note that we already checked for equality of the type
833 qualifiers (just above). */
834
835 if (TREE_CODE (t1) != ARRAY_TYPE
836 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
837 return 1;
838
839 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
840 if (!(attrval = targetm.comp_type_attributes (t1, t2)))
841 return 0;
842
843 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
844 val = 0;
845
846 switch (TREE_CODE (t1))
847 {
848 case POINTER_TYPE:
849 /* Do not remove mode or aliasing information. */
850 if (TYPE_MODE (t1) != TYPE_MODE (t2)
851 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2))
852 break;
853 val = (TREE_TYPE (t1) == TREE_TYPE (t2)
854 ? 1 : comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2)));
855 break;
856
857 case FUNCTION_TYPE:
858 val = function_types_compatible_p (t1, t2);
859 break;
860
861 case ARRAY_TYPE:
862 {
863 tree d1 = TYPE_DOMAIN (t1);
864 tree d2 = TYPE_DOMAIN (t2);
865 bool d1_variable, d2_variable;
866 bool d1_zero, d2_zero;
867 val = 1;
868
869 /* Target types must match incl. qualifiers. */
870 if (TREE_TYPE (t1) != TREE_TYPE (t2)
871 && 0 == (val = comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2))))
872 return 0;
873
874 /* Sizes must match unless one is missing or variable. */
875 if (d1 == 0 || d2 == 0 || d1 == d2)
876 break;
877
878 d1_zero = !TYPE_MAX_VALUE (d1);
879 d2_zero = !TYPE_MAX_VALUE (d2);
880
881 d1_variable = (!d1_zero
882 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
883 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
884 d2_variable = (!d2_zero
885 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
886 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
887 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
888 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
889
890 if (d1_variable || d2_variable)
891 break;
892 if (d1_zero && d2_zero)
893 break;
894 if (d1_zero || d2_zero
895 || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
896 || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
897 val = 0;
898
899 break;
900 }
901
902 case ENUMERAL_TYPE:
903 case RECORD_TYPE:
904 case UNION_TYPE:
905 if (val != 1 && !same_translation_unit_p (t1, t2))
906 {
907 tree a1 = TYPE_ATTRIBUTES (t1);
908 tree a2 = TYPE_ATTRIBUTES (t2);
909
910 if (! attribute_list_contained (a1, a2)
911 && ! attribute_list_contained (a2, a1))
912 break;
913
914 if (attrval != 2)
915 return tagged_types_tu_compatible_p (t1, t2);
916 val = tagged_types_tu_compatible_p (t1, t2);
917 }
918 break;
919
920 case VECTOR_TYPE:
921 val = TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
922 && comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2));
923 break;
924
925 default:
926 break;
927 }
928 return attrval == 2 && val == 1 ? 2 : val;
929 }
930
931 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
932 ignoring their qualifiers. */
933
934 static int
935 comp_target_types (tree ttl, tree ttr)
936 {
937 int val;
938 tree mvl, mvr;
939
940 /* Do not lose qualifiers on element types of array types that are
941 pointer targets by taking their TYPE_MAIN_VARIANT. */
942 mvl = TREE_TYPE (ttl);
943 mvr = TREE_TYPE (ttr);
944 if (TREE_CODE (mvl) != ARRAY_TYPE)
945 mvl = TYPE_MAIN_VARIANT (mvl);
946 if (TREE_CODE (mvr) != ARRAY_TYPE)
947 mvr = TYPE_MAIN_VARIANT (mvr);
948 val = comptypes (mvl, mvr);
949
950 if (val == 2 && pedantic)
951 pedwarn ("types are not quite compatible");
952 return val;
953 }
954 \f
955 /* Subroutines of `comptypes'. */
956
957 /* Determine whether two trees derive from the same translation unit.
958 If the CONTEXT chain ends in a null, that tree's context is still
959 being parsed, so if two trees have context chains ending in null,
960 they're in the same translation unit. */
961 int
962 same_translation_unit_p (tree t1, tree t2)
963 {
964 while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL)
965 switch (TREE_CODE_CLASS (TREE_CODE (t1)))
966 {
967 case tcc_declaration:
968 t1 = DECL_CONTEXT (t1); break;
969 case tcc_type:
970 t1 = TYPE_CONTEXT (t1); break;
971 case tcc_exceptional:
972 t1 = BLOCK_SUPERCONTEXT (t1); break; /* assume block */
973 default: gcc_unreachable ();
974 }
975
976 while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL)
977 switch (TREE_CODE_CLASS (TREE_CODE (t2)))
978 {
979 case tcc_declaration:
980 t2 = DECL_CONTEXT (t2); break;
981 case tcc_type:
982 t2 = TYPE_CONTEXT (t2); break;
983 case tcc_exceptional:
984 t2 = BLOCK_SUPERCONTEXT (t2); break; /* assume block */
985 default: gcc_unreachable ();
986 }
987
988 return t1 == t2;
989 }
990
991 /* Allocate the seen two types, assuming that they are compatible. */
992
993 static struct tagged_tu_seen_cache *
994 alloc_tagged_tu_seen_cache (tree t1, tree t2)
995 {
996 struct tagged_tu_seen_cache *tu = XNEW (struct tagged_tu_seen_cache);
997 tu->next = tagged_tu_seen_base;
998 tu->t1 = t1;
999 tu->t2 = t2;
1000
1001 tagged_tu_seen_base = tu;
1002
1003 /* The C standard says that two structures in different translation
1004 units are compatible with each other only if the types of their
1005 fields are compatible (among other things). We assume that they
1006 are compatible until proven otherwise when building the cache.
1007 An example where this can occur is:
1008 struct a
1009 {
1010 struct a *next;
1011 };
1012 If we are comparing this against a similar struct in another TU,
1013 and did not assume they were compatible, we end up with an infinite
1014 loop. */
1015 tu->val = 1;
1016 return tu;
1017 }
1018
1019 /* Free the seen types until we get to TU_TIL. */
1020
1021 static void
1022 free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *tu_til)
1023 {
1024 const struct tagged_tu_seen_cache *tu = tagged_tu_seen_base;
1025 while (tu != tu_til)
1026 {
1027 struct tagged_tu_seen_cache *tu1 = (struct tagged_tu_seen_cache*)tu;
1028 tu = tu1->next;
1029 free (tu1);
1030 }
1031 tagged_tu_seen_base = tu_til;
1032 }
1033
1034 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1035 compatible. If the two types are not the same (which has been
1036 checked earlier), this can only happen when multiple translation
1037 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1038 rules. */
1039
1040 static int
1041 tagged_types_tu_compatible_p (tree t1, tree t2)
1042 {
1043 tree s1, s2;
1044 bool needs_warning = false;
1045
1046 /* We have to verify that the tags of the types are the same. This
1047 is harder than it looks because this may be a typedef, so we have
1048 to go look at the original type. It may even be a typedef of a
1049 typedef...
1050 In the case of compiler-created builtin structs the TYPE_DECL
1051 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1052 while (TYPE_NAME (t1)
1053 && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL
1054 && DECL_ORIGINAL_TYPE (TYPE_NAME (t1)))
1055 t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1));
1056
1057 while (TYPE_NAME (t2)
1058 && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL
1059 && DECL_ORIGINAL_TYPE (TYPE_NAME (t2)))
1060 t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2));
1061
1062 /* C90 didn't have the requirement that the two tags be the same. */
1063 if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2))
1064 return 0;
1065
1066 /* C90 didn't say what happened if one or both of the types were
1067 incomplete; we choose to follow C99 rules here, which is that they
1068 are compatible. */
1069 if (TYPE_SIZE (t1) == NULL
1070 || TYPE_SIZE (t2) == NULL)
1071 return 1;
1072
1073 {
1074 const struct tagged_tu_seen_cache * tts_i;
1075 for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next)
1076 if (tts_i->t1 == t1 && tts_i->t2 == t2)
1077 return tts_i->val;
1078 }
1079
1080 switch (TREE_CODE (t1))
1081 {
1082 case ENUMERAL_TYPE:
1083 {
1084 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1085 /* Speed up the case where the type values are in the same order. */
1086 tree tv1 = TYPE_VALUES (t1);
1087 tree tv2 = TYPE_VALUES (t2);
1088
1089 if (tv1 == tv2)
1090 {
1091 return 1;
1092 }
1093
1094 for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2))
1095 {
1096 if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2))
1097 break;
1098 if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1)
1099 {
1100 tu->val = 0;
1101 return 0;
1102 }
1103 }
1104
1105 if (tv1 == NULL_TREE && tv2 == NULL_TREE)
1106 {
1107 return 1;
1108 }
1109 if (tv1 == NULL_TREE || tv2 == NULL_TREE)
1110 {
1111 tu->val = 0;
1112 return 0;
1113 }
1114
1115 if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2)))
1116 {
1117 tu->val = 0;
1118 return 0;
1119 }
1120
1121 for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1))
1122 {
1123 s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2));
1124 if (s2 == NULL
1125 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1)
1126 {
1127 tu->val = 0;
1128 return 0;
1129 }
1130 }
1131 return 1;
1132 }
1133
1134 case UNION_TYPE:
1135 {
1136 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1137 if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2)))
1138 {
1139 tu->val = 0;
1140 return 0;
1141 }
1142
1143 /* Speed up the common case where the fields are in the same order. */
1144 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2;
1145 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1146 {
1147 int result;
1148
1149
1150 if (DECL_NAME (s1) == NULL
1151 || DECL_NAME (s1) != DECL_NAME (s2))
1152 break;
1153 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1154 if (result == 0)
1155 {
1156 tu->val = 0;
1157 return 0;
1158 }
1159 if (result == 2)
1160 needs_warning = true;
1161
1162 if (TREE_CODE (s1) == FIELD_DECL
1163 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1164 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1165 {
1166 tu->val = 0;
1167 return 0;
1168 }
1169 }
1170 if (!s1 && !s2)
1171 {
1172 tu->val = needs_warning ? 2 : 1;
1173 return tu->val;
1174 }
1175
1176 for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1))
1177 {
1178 bool ok = false;
1179
1180 if (DECL_NAME (s1) != NULL)
1181 for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2))
1182 if (DECL_NAME (s1) == DECL_NAME (s2))
1183 {
1184 int result;
1185 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1186 if (result == 0)
1187 {
1188 tu->val = 0;
1189 return 0;
1190 }
1191 if (result == 2)
1192 needs_warning = true;
1193
1194 if (TREE_CODE (s1) == FIELD_DECL
1195 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1196 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1197 break;
1198
1199 ok = true;
1200 break;
1201 }
1202 if (!ok)
1203 {
1204 tu->val = 0;
1205 return 0;
1206 }
1207 }
1208 tu->val = needs_warning ? 2 : 10;
1209 return tu->val;
1210 }
1211
1212 case RECORD_TYPE:
1213 {
1214 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1215
1216 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2);
1217 s1 && s2;
1218 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1219 {
1220 int result;
1221 if (TREE_CODE (s1) != TREE_CODE (s2)
1222 || DECL_NAME (s1) != DECL_NAME (s2))
1223 break;
1224 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1225 if (result == 0)
1226 break;
1227 if (result == 2)
1228 needs_warning = true;
1229
1230 if (TREE_CODE (s1) == FIELD_DECL
1231 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1232 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1233 break;
1234 }
1235 if (s1 && s2)
1236 tu->val = 0;
1237 else
1238 tu->val = needs_warning ? 2 : 1;
1239 return tu->val;
1240 }
1241
1242 default:
1243 gcc_unreachable ();
1244 }
1245 }
1246
1247 /* Return 1 if two function types F1 and F2 are compatible.
1248 If either type specifies no argument types,
1249 the other must specify a fixed number of self-promoting arg types.
1250 Otherwise, if one type specifies only the number of arguments,
1251 the other must specify that number of self-promoting arg types.
1252 Otherwise, the argument types must match. */
1253
1254 static int
1255 function_types_compatible_p (tree f1, tree f2)
1256 {
1257 tree args1, args2;
1258 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1259 int val = 1;
1260 int val1;
1261 tree ret1, ret2;
1262
1263 ret1 = TREE_TYPE (f1);
1264 ret2 = TREE_TYPE (f2);
1265
1266 /* 'volatile' qualifiers on a function's return type used to mean
1267 the function is noreturn. */
1268 if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2))
1269 pedwarn ("function return types not compatible due to %<volatile%>");
1270 if (TYPE_VOLATILE (ret1))
1271 ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1),
1272 TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE);
1273 if (TYPE_VOLATILE (ret2))
1274 ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2),
1275 TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE);
1276 val = comptypes_internal (ret1, ret2);
1277 if (val == 0)
1278 return 0;
1279
1280 args1 = TYPE_ARG_TYPES (f1);
1281 args2 = TYPE_ARG_TYPES (f2);
1282
1283 /* An unspecified parmlist matches any specified parmlist
1284 whose argument types don't need default promotions. */
1285
1286 if (args1 == 0)
1287 {
1288 if (!self_promoting_args_p (args2))
1289 return 0;
1290 /* If one of these types comes from a non-prototype fn definition,
1291 compare that with the other type's arglist.
1292 If they don't match, ask for a warning (but no error). */
1293 if (TYPE_ACTUAL_ARG_TYPES (f1)
1294 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
1295 val = 2;
1296 return val;
1297 }
1298 if (args2 == 0)
1299 {
1300 if (!self_promoting_args_p (args1))
1301 return 0;
1302 if (TYPE_ACTUAL_ARG_TYPES (f2)
1303 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
1304 val = 2;
1305 return val;
1306 }
1307
1308 /* Both types have argument lists: compare them and propagate results. */
1309 val1 = type_lists_compatible_p (args1, args2);
1310 return val1 != 1 ? val1 : val;
1311 }
1312
1313 /* Check two lists of types for compatibility,
1314 returning 0 for incompatible, 1 for compatible,
1315 or 2 for compatible with warning. */
1316
1317 static int
1318 type_lists_compatible_p (tree args1, tree args2)
1319 {
1320 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1321 int val = 1;
1322 int newval = 0;
1323
1324 while (1)
1325 {
1326 tree a1, mv1, a2, mv2;
1327 if (args1 == 0 && args2 == 0)
1328 return val;
1329 /* If one list is shorter than the other,
1330 they fail to match. */
1331 if (args1 == 0 || args2 == 0)
1332 return 0;
1333 mv1 = a1 = TREE_VALUE (args1);
1334 mv2 = a2 = TREE_VALUE (args2);
1335 if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE)
1336 mv1 = TYPE_MAIN_VARIANT (mv1);
1337 if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE)
1338 mv2 = TYPE_MAIN_VARIANT (mv2);
1339 /* A null pointer instead of a type
1340 means there is supposed to be an argument
1341 but nothing is specified about what type it has.
1342 So match anything that self-promotes. */
1343 if (a1 == 0)
1344 {
1345 if (c_type_promotes_to (a2) != a2)
1346 return 0;
1347 }
1348 else if (a2 == 0)
1349 {
1350 if (c_type_promotes_to (a1) != a1)
1351 return 0;
1352 }
1353 /* If one of the lists has an error marker, ignore this arg. */
1354 else if (TREE_CODE (a1) == ERROR_MARK
1355 || TREE_CODE (a2) == ERROR_MARK)
1356 ;
1357 else if (!(newval = comptypes_internal (mv1, mv2)))
1358 {
1359 /* Allow wait (union {union wait *u; int *i} *)
1360 and wait (union wait *) to be compatible. */
1361 if (TREE_CODE (a1) == UNION_TYPE
1362 && (TYPE_NAME (a1) == 0
1363 || TYPE_TRANSPARENT_UNION (a1))
1364 && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST
1365 && tree_int_cst_equal (TYPE_SIZE (a1),
1366 TYPE_SIZE (a2)))
1367 {
1368 tree memb;
1369 for (memb = TYPE_FIELDS (a1);
1370 memb; memb = TREE_CHAIN (memb))
1371 {
1372 tree mv3 = TREE_TYPE (memb);
1373 if (mv3 && mv3 != error_mark_node
1374 && TREE_CODE (mv3) != ARRAY_TYPE)
1375 mv3 = TYPE_MAIN_VARIANT (mv3);
1376 if (comptypes_internal (mv3, mv2))
1377 break;
1378 }
1379 if (memb == 0)
1380 return 0;
1381 }
1382 else if (TREE_CODE (a2) == UNION_TYPE
1383 && (TYPE_NAME (a2) == 0
1384 || TYPE_TRANSPARENT_UNION (a2))
1385 && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST
1386 && tree_int_cst_equal (TYPE_SIZE (a2),
1387 TYPE_SIZE (a1)))
1388 {
1389 tree memb;
1390 for (memb = TYPE_FIELDS (a2);
1391 memb; memb = TREE_CHAIN (memb))
1392 {
1393 tree mv3 = TREE_TYPE (memb);
1394 if (mv3 && mv3 != error_mark_node
1395 && TREE_CODE (mv3) != ARRAY_TYPE)
1396 mv3 = TYPE_MAIN_VARIANT (mv3);
1397 if (comptypes_internal (mv3, mv1))
1398 break;
1399 }
1400 if (memb == 0)
1401 return 0;
1402 }
1403 else
1404 return 0;
1405 }
1406
1407 /* comptypes said ok, but record if it said to warn. */
1408 if (newval > val)
1409 val = newval;
1410
1411 args1 = TREE_CHAIN (args1);
1412 args2 = TREE_CHAIN (args2);
1413 }
1414 }
1415 \f
1416 /* Compute the size to increment a pointer by. */
1417
1418 static tree
1419 c_size_in_bytes (tree type)
1420 {
1421 enum tree_code code = TREE_CODE (type);
1422
1423 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
1424 return size_one_node;
1425
1426 if (!COMPLETE_OR_VOID_TYPE_P (type))
1427 {
1428 error ("arithmetic on pointer to an incomplete type");
1429 return size_one_node;
1430 }
1431
1432 /* Convert in case a char is more than one unit. */
1433 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
1434 size_int (TYPE_PRECISION (char_type_node)
1435 / BITS_PER_UNIT));
1436 }
1437 \f
1438 /* Return either DECL or its known constant value (if it has one). */
1439
1440 tree
1441 decl_constant_value (tree decl)
1442 {
1443 if (/* Don't change a variable array bound or initial value to a constant
1444 in a place where a variable is invalid. Note that DECL_INITIAL
1445 isn't valid for a PARM_DECL. */
1446 current_function_decl != 0
1447 && TREE_CODE (decl) != PARM_DECL
1448 && !TREE_THIS_VOLATILE (decl)
1449 && TREE_READONLY (decl)
1450 && DECL_INITIAL (decl) != 0
1451 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
1452 /* This is invalid if initial value is not constant.
1453 If it has either a function call, a memory reference,
1454 or a variable, then re-evaluating it could give different results. */
1455 && TREE_CONSTANT (DECL_INITIAL (decl))
1456 /* Check for cases where this is sub-optimal, even though valid. */
1457 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
1458 return DECL_INITIAL (decl);
1459 return decl;
1460 }
1461
1462 /* Return either DECL or its known constant value (if it has one), but
1463 return DECL if pedantic or DECL has mode BLKmode. This is for
1464 bug-compatibility with the old behavior of decl_constant_value
1465 (before GCC 3.0); every use of this function is a bug and it should
1466 be removed before GCC 3.1. It is not appropriate to use pedantic
1467 in a way that affects optimization, and BLKmode is probably not the
1468 right test for avoiding misoptimizations either. */
1469
1470 static tree
1471 decl_constant_value_for_broken_optimization (tree decl)
1472 {
1473 tree ret;
1474
1475 if (pedantic || DECL_MODE (decl) == BLKmode)
1476 return decl;
1477
1478 ret = decl_constant_value (decl);
1479 /* Avoid unwanted tree sharing between the initializer and current
1480 function's body where the tree can be modified e.g. by the
1481 gimplifier. */
1482 if (ret != decl && TREE_STATIC (decl))
1483 ret = unshare_expr (ret);
1484 return ret;
1485 }
1486
1487 /* Convert the array expression EXP to a pointer. */
1488 static tree
1489 array_to_pointer_conversion (tree exp)
1490 {
1491 tree orig_exp = exp;
1492 tree type = TREE_TYPE (exp);
1493 tree adr;
1494 tree restype = TREE_TYPE (type);
1495 tree ptrtype;
1496
1497 gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
1498
1499 STRIP_TYPE_NOPS (exp);
1500
1501 if (TREE_NO_WARNING (orig_exp))
1502 TREE_NO_WARNING (exp) = 1;
1503
1504 ptrtype = build_pointer_type (restype);
1505
1506 if (TREE_CODE (exp) == INDIRECT_REF)
1507 return convert (ptrtype, TREE_OPERAND (exp, 0));
1508
1509 if (TREE_CODE (exp) == VAR_DECL)
1510 {
1511 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1512 ADDR_EXPR because it's the best way of representing what
1513 happens in C when we take the address of an array and place
1514 it in a pointer to the element type. */
1515 adr = build1 (ADDR_EXPR, ptrtype, exp);
1516 if (!c_mark_addressable (exp))
1517 return error_mark_node;
1518 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
1519 return adr;
1520 }
1521
1522 /* This way is better for a COMPONENT_REF since it can
1523 simplify the offset for a component. */
1524 adr = build_unary_op (ADDR_EXPR, exp, 1);
1525 return convert (ptrtype, adr);
1526 }
1527
1528 /* Convert the function expression EXP to a pointer. */
1529 static tree
1530 function_to_pointer_conversion (tree exp)
1531 {
1532 tree orig_exp = exp;
1533
1534 gcc_assert (TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE);
1535
1536 STRIP_TYPE_NOPS (exp);
1537
1538 if (TREE_NO_WARNING (orig_exp))
1539 TREE_NO_WARNING (exp) = 1;
1540
1541 return build_unary_op (ADDR_EXPR, exp, 0);
1542 }
1543
1544 /* Perform the default conversion of arrays and functions to pointers.
1545 Return the result of converting EXP. For any other expression, just
1546 return EXP after removing NOPs. */
1547
1548 struct c_expr
1549 default_function_array_conversion (struct c_expr exp)
1550 {
1551 tree orig_exp = exp.value;
1552 tree type = TREE_TYPE (exp.value);
1553 enum tree_code code = TREE_CODE (type);
1554
1555 switch (code)
1556 {
1557 case ARRAY_TYPE:
1558 {
1559 bool not_lvalue = false;
1560 bool lvalue_array_p;
1561
1562 while ((TREE_CODE (exp.value) == NON_LVALUE_EXPR
1563 || TREE_CODE (exp.value) == NOP_EXPR
1564 || TREE_CODE (exp.value) == CONVERT_EXPR)
1565 && TREE_TYPE (TREE_OPERAND (exp.value, 0)) == type)
1566 {
1567 if (TREE_CODE (exp.value) == NON_LVALUE_EXPR)
1568 not_lvalue = true;
1569 exp.value = TREE_OPERAND (exp.value, 0);
1570 }
1571
1572 if (TREE_NO_WARNING (orig_exp))
1573 TREE_NO_WARNING (exp.value) = 1;
1574
1575 lvalue_array_p = !not_lvalue && lvalue_p (exp.value);
1576 if (!flag_isoc99 && !lvalue_array_p)
1577 {
1578 /* Before C99, non-lvalue arrays do not decay to pointers.
1579 Normally, using such an array would be invalid; but it can
1580 be used correctly inside sizeof or as a statement expression.
1581 Thus, do not give an error here; an error will result later. */
1582 return exp;
1583 }
1584
1585 exp.value = array_to_pointer_conversion (exp.value);
1586 }
1587 break;
1588 case FUNCTION_TYPE:
1589 exp.value = function_to_pointer_conversion (exp.value);
1590 break;
1591 default:
1592 STRIP_TYPE_NOPS (exp.value);
1593 if (TREE_NO_WARNING (orig_exp))
1594 TREE_NO_WARNING (exp.value) = 1;
1595 break;
1596 }
1597
1598 return exp;
1599 }
1600
1601
1602 /* EXP is an expression of integer type. Apply the integer promotions
1603 to it and return the promoted value. */
1604
1605 tree
1606 perform_integral_promotions (tree exp)
1607 {
1608 tree type = TREE_TYPE (exp);
1609 enum tree_code code = TREE_CODE (type);
1610
1611 gcc_assert (INTEGRAL_TYPE_P (type));
1612
1613 /* Normally convert enums to int,
1614 but convert wide enums to something wider. */
1615 if (code == ENUMERAL_TYPE)
1616 {
1617 type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
1618 TYPE_PRECISION (integer_type_node)),
1619 ((TYPE_PRECISION (type)
1620 >= TYPE_PRECISION (integer_type_node))
1621 && TYPE_UNSIGNED (type)));
1622
1623 return convert (type, exp);
1624 }
1625
1626 /* ??? This should no longer be needed now bit-fields have their
1627 proper types. */
1628 if (TREE_CODE (exp) == COMPONENT_REF
1629 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
1630 /* If it's thinner than an int, promote it like a
1631 c_promoting_integer_type_p, otherwise leave it alone. */
1632 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
1633 TYPE_PRECISION (integer_type_node)))
1634 return convert (integer_type_node, exp);
1635
1636 if (c_promoting_integer_type_p (type))
1637 {
1638 /* Preserve unsignedness if not really getting any wider. */
1639 if (TYPE_UNSIGNED (type)
1640 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
1641 return convert (unsigned_type_node, exp);
1642
1643 return convert (integer_type_node, exp);
1644 }
1645
1646 return exp;
1647 }
1648
1649
1650 /* Perform default promotions for C data used in expressions.
1651 Enumeral types or short or char are converted to int.
1652 In addition, manifest constants symbols are replaced by their values. */
1653
1654 tree
1655 default_conversion (tree exp)
1656 {
1657 tree orig_exp;
1658 tree type = TREE_TYPE (exp);
1659 enum tree_code code = TREE_CODE (type);
1660
1661 /* Functions and arrays have been converted during parsing. */
1662 gcc_assert (code != FUNCTION_TYPE);
1663 if (code == ARRAY_TYPE)
1664 return exp;
1665
1666 /* Constants can be used directly unless they're not loadable. */
1667 if (TREE_CODE (exp) == CONST_DECL)
1668 exp = DECL_INITIAL (exp);
1669
1670 /* Replace a nonvolatile const static variable with its value unless
1671 it is an array, in which case we must be sure that taking the
1672 address of the array produces consistent results. */
1673 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE)
1674 {
1675 exp = decl_constant_value_for_broken_optimization (exp);
1676 type = TREE_TYPE (exp);
1677 }
1678
1679 /* Strip no-op conversions. */
1680 orig_exp = exp;
1681 STRIP_TYPE_NOPS (exp);
1682
1683 if (TREE_NO_WARNING (orig_exp))
1684 TREE_NO_WARNING (exp) = 1;
1685
1686 if (INTEGRAL_TYPE_P (type))
1687 return perform_integral_promotions (exp);
1688
1689 if (code == VOID_TYPE)
1690 {
1691 error ("void value not ignored as it ought to be");
1692 return error_mark_node;
1693 }
1694 return exp;
1695 }
1696 \f
1697 /* Look up COMPONENT in a structure or union DECL.
1698
1699 If the component name is not found, returns NULL_TREE. Otherwise,
1700 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1701 stepping down the chain to the component, which is in the last
1702 TREE_VALUE of the list. Normally the list is of length one, but if
1703 the component is embedded within (nested) anonymous structures or
1704 unions, the list steps down the chain to the component. */
1705
1706 static tree
1707 lookup_field (tree decl, tree component)
1708 {
1709 tree type = TREE_TYPE (decl);
1710 tree field;
1711
1712 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1713 to the field elements. Use a binary search on this array to quickly
1714 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1715 will always be set for structures which have many elements. */
1716
1717 if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s)
1718 {
1719 int bot, top, half;
1720 tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0];
1721
1722 field = TYPE_FIELDS (type);
1723 bot = 0;
1724 top = TYPE_LANG_SPECIFIC (type)->s->len;
1725 while (top - bot > 1)
1726 {
1727 half = (top - bot + 1) >> 1;
1728 field = field_array[bot+half];
1729
1730 if (DECL_NAME (field) == NULL_TREE)
1731 {
1732 /* Step through all anon unions in linear fashion. */
1733 while (DECL_NAME (field_array[bot]) == NULL_TREE)
1734 {
1735 field = field_array[bot++];
1736 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1737 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1738 {
1739 tree anon = lookup_field (field, component);
1740
1741 if (anon)
1742 return tree_cons (NULL_TREE, field, anon);
1743 }
1744 }
1745
1746 /* Entire record is only anon unions. */
1747 if (bot > top)
1748 return NULL_TREE;
1749
1750 /* Restart the binary search, with new lower bound. */
1751 continue;
1752 }
1753
1754 if (DECL_NAME (field) == component)
1755 break;
1756 if (DECL_NAME (field) < component)
1757 bot += half;
1758 else
1759 top = bot + half;
1760 }
1761
1762 if (DECL_NAME (field_array[bot]) == component)
1763 field = field_array[bot];
1764 else if (DECL_NAME (field) != component)
1765 return NULL_TREE;
1766 }
1767 else
1768 {
1769 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1770 {
1771 if (DECL_NAME (field) == NULL_TREE
1772 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1773 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
1774 {
1775 tree anon = lookup_field (field, component);
1776
1777 if (anon)
1778 return tree_cons (NULL_TREE, field, anon);
1779 }
1780
1781 if (DECL_NAME (field) == component)
1782 break;
1783 }
1784
1785 if (field == NULL_TREE)
1786 return NULL_TREE;
1787 }
1788
1789 return tree_cons (NULL_TREE, field, NULL_TREE);
1790 }
1791
1792 /* Make an expression to refer to the COMPONENT field of
1793 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1794
1795 tree
1796 build_component_ref (tree datum, tree component)
1797 {
1798 tree type = TREE_TYPE (datum);
1799 enum tree_code code = TREE_CODE (type);
1800 tree field = NULL;
1801 tree ref;
1802
1803 if (!objc_is_public (datum, component))
1804 return error_mark_node;
1805
1806 /* See if there is a field or component with name COMPONENT. */
1807
1808 if (code == RECORD_TYPE || code == UNION_TYPE)
1809 {
1810 if (!COMPLETE_TYPE_P (type))
1811 {
1812 c_incomplete_type_error (NULL_TREE, type);
1813 return error_mark_node;
1814 }
1815
1816 field = lookup_field (datum, component);
1817
1818 if (!field)
1819 {
1820 error ("%qT has no member named %qE", type, component);
1821 return error_mark_node;
1822 }
1823
1824 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1825 This might be better solved in future the way the C++ front
1826 end does it - by giving the anonymous entities each a
1827 separate name and type, and then have build_component_ref
1828 recursively call itself. We can't do that here. */
1829 do
1830 {
1831 tree subdatum = TREE_VALUE (field);
1832 int quals;
1833 tree subtype;
1834
1835 if (TREE_TYPE (subdatum) == error_mark_node)
1836 return error_mark_node;
1837
1838 quals = TYPE_QUALS (strip_array_types (TREE_TYPE (subdatum)));
1839 quals |= TYPE_QUALS (TREE_TYPE (datum));
1840 subtype = c_build_qualified_type (TREE_TYPE (subdatum), quals);
1841
1842 ref = build3 (COMPONENT_REF, subtype, datum, subdatum,
1843 NULL_TREE);
1844 if (TREE_READONLY (datum) || TREE_READONLY (subdatum))
1845 TREE_READONLY (ref) = 1;
1846 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
1847 TREE_THIS_VOLATILE (ref) = 1;
1848
1849 if (TREE_DEPRECATED (subdatum))
1850 warn_deprecated_use (subdatum);
1851
1852 datum = ref;
1853
1854 field = TREE_CHAIN (field);
1855 }
1856 while (field);
1857
1858 return ref;
1859 }
1860 else if (code != ERROR_MARK)
1861 error ("request for member %qE in something not a structure or union",
1862 component);
1863
1864 return error_mark_node;
1865 }
1866 \f
1867 /* Given an expression PTR for a pointer, return an expression
1868 for the value pointed to.
1869 ERRORSTRING is the name of the operator to appear in error messages. */
1870
1871 tree
1872 build_indirect_ref (tree ptr, const char *errorstring)
1873 {
1874 tree pointer = default_conversion (ptr);
1875 tree type = TREE_TYPE (pointer);
1876
1877 if (TREE_CODE (type) == POINTER_TYPE)
1878 {
1879 if (TREE_CODE (pointer) == ADDR_EXPR
1880 && (TREE_TYPE (TREE_OPERAND (pointer, 0))
1881 == TREE_TYPE (type)))
1882 return TREE_OPERAND (pointer, 0);
1883 else
1884 {
1885 tree t = TREE_TYPE (type);
1886 tree ref;
1887
1888 ref = build1 (INDIRECT_REF, t, pointer);
1889
1890 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
1891 {
1892 error ("dereferencing pointer to incomplete type");
1893 return error_mark_node;
1894 }
1895 if (VOID_TYPE_P (t) && skip_evaluation == 0)
1896 warning (0, "dereferencing %<void *%> pointer");
1897
1898 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1899 so that we get the proper error message if the result is used
1900 to assign to. Also, &* is supposed to be a no-op.
1901 And ANSI C seems to specify that the type of the result
1902 should be the const type. */
1903 /* A de-reference of a pointer to const is not a const. It is valid
1904 to change it via some other pointer. */
1905 TREE_READONLY (ref) = TYPE_READONLY (t);
1906 TREE_SIDE_EFFECTS (ref)
1907 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
1908 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
1909 return ref;
1910 }
1911 }
1912 else if (TREE_CODE (pointer) != ERROR_MARK)
1913 error ("invalid type argument of %qs", errorstring);
1914 return error_mark_node;
1915 }
1916
1917 /* This handles expressions of the form "a[i]", which denotes
1918 an array reference.
1919
1920 This is logically equivalent in C to *(a+i), but we may do it differently.
1921 If A is a variable or a member, we generate a primitive ARRAY_REF.
1922 This avoids forcing the array out of registers, and can work on
1923 arrays that are not lvalues (for example, members of structures returned
1924 by functions). */
1925
1926 tree
1927 build_array_ref (tree array, tree index)
1928 {
1929 bool swapped = false;
1930 if (TREE_TYPE (array) == error_mark_node
1931 || TREE_TYPE (index) == error_mark_node)
1932 return error_mark_node;
1933
1934 if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE
1935 && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE)
1936 {
1937 tree temp;
1938 if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE
1939 && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE)
1940 {
1941 error ("subscripted value is neither array nor pointer");
1942 return error_mark_node;
1943 }
1944 temp = array;
1945 array = index;
1946 index = temp;
1947 swapped = true;
1948 }
1949
1950 if (!INTEGRAL_TYPE_P (TREE_TYPE (index)))
1951 {
1952 error ("array subscript is not an integer");
1953 return error_mark_node;
1954 }
1955
1956 if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE)
1957 {
1958 error ("subscripted value is pointer to function");
1959 return error_mark_node;
1960 }
1961
1962 /* ??? Existing practice has been to warn only when the char
1963 index is syntactically the index, not for char[array]. */
1964 if (!swapped)
1965 warn_array_subscript_with_type_char (index);
1966
1967 /* Apply default promotions *after* noticing character types. */
1968 index = default_conversion (index);
1969
1970 gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
1971
1972 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
1973 {
1974 tree rval, type;
1975
1976 /* An array that is indexed by a non-constant
1977 cannot be stored in a register; we must be able to do
1978 address arithmetic on its address.
1979 Likewise an array of elements of variable size. */
1980 if (TREE_CODE (index) != INTEGER_CST
1981 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
1982 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
1983 {
1984 if (!c_mark_addressable (array))
1985 return error_mark_node;
1986 }
1987 /* An array that is indexed by a constant value which is not within
1988 the array bounds cannot be stored in a register either; because we
1989 would get a crash in store_bit_field/extract_bit_field when trying
1990 to access a non-existent part of the register. */
1991 if (TREE_CODE (index) == INTEGER_CST
1992 && TYPE_DOMAIN (TREE_TYPE (array))
1993 && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array))))
1994 {
1995 if (!c_mark_addressable (array))
1996 return error_mark_node;
1997 }
1998
1999 if (pedantic)
2000 {
2001 tree foo = array;
2002 while (TREE_CODE (foo) == COMPONENT_REF)
2003 foo = TREE_OPERAND (foo, 0);
2004 if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
2005 pedwarn ("ISO C forbids subscripting %<register%> array");
2006 else if (!flag_isoc99 && !lvalue_p (foo))
2007 pedwarn ("ISO C90 forbids subscripting non-lvalue array");
2008 }
2009
2010 type = TREE_TYPE (TREE_TYPE (array));
2011 if (TREE_CODE (type) != ARRAY_TYPE)
2012 type = TYPE_MAIN_VARIANT (type);
2013 rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE);
2014 /* Array ref is const/volatile if the array elements are
2015 or if the array is. */
2016 TREE_READONLY (rval)
2017 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
2018 | TREE_READONLY (array));
2019 TREE_SIDE_EFFECTS (rval)
2020 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2021 | TREE_SIDE_EFFECTS (array));
2022 TREE_THIS_VOLATILE (rval)
2023 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2024 /* This was added by rms on 16 Nov 91.
2025 It fixes vol struct foo *a; a->elts[1]
2026 in an inline function.
2027 Hope it doesn't break something else. */
2028 | TREE_THIS_VOLATILE (array));
2029 return require_complete_type (fold (rval));
2030 }
2031 else
2032 {
2033 tree ar = default_conversion (array);
2034
2035 if (ar == error_mark_node)
2036 return ar;
2037
2038 gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE);
2039 gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE);
2040
2041 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0),
2042 "array indexing");
2043 }
2044 }
2045 \f
2046 /* Build an external reference to identifier ID. FUN indicates
2047 whether this will be used for a function call. LOC is the source
2048 location of the identifier. */
2049 tree
2050 build_external_ref (tree id, int fun, location_t loc)
2051 {
2052 tree ref;
2053 tree decl = lookup_name (id);
2054
2055 /* In Objective-C, an instance variable (ivar) may be preferred to
2056 whatever lookup_name() found. */
2057 decl = objc_lookup_ivar (decl, id);
2058
2059 if (decl && decl != error_mark_node)
2060 ref = decl;
2061 else if (fun)
2062 /* Implicit function declaration. */
2063 ref = implicitly_declare (id);
2064 else if (decl == error_mark_node)
2065 /* Don't complain about something that's already been
2066 complained about. */
2067 return error_mark_node;
2068 else
2069 {
2070 undeclared_variable (id, loc);
2071 return error_mark_node;
2072 }
2073
2074 if (TREE_TYPE (ref) == error_mark_node)
2075 return error_mark_node;
2076
2077 if (TREE_DEPRECATED (ref))
2078 warn_deprecated_use (ref);
2079
2080 if (!skip_evaluation)
2081 assemble_external (ref);
2082 TREE_USED (ref) = 1;
2083
2084 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof)
2085 {
2086 if (!in_sizeof && !in_typeof)
2087 C_DECL_USED (ref) = 1;
2088 else if (DECL_INITIAL (ref) == 0
2089 && DECL_EXTERNAL (ref)
2090 && !TREE_PUBLIC (ref))
2091 record_maybe_used_decl (ref);
2092 }
2093
2094 if (TREE_CODE (ref) == CONST_DECL)
2095 {
2096 used_types_insert (TREE_TYPE (ref));
2097 ref = DECL_INITIAL (ref);
2098 TREE_CONSTANT (ref) = 1;
2099 TREE_INVARIANT (ref) = 1;
2100 }
2101 else if (current_function_decl != 0
2102 && !DECL_FILE_SCOPE_P (current_function_decl)
2103 && (TREE_CODE (ref) == VAR_DECL
2104 || TREE_CODE (ref) == PARM_DECL
2105 || TREE_CODE (ref) == FUNCTION_DECL))
2106 {
2107 tree context = decl_function_context (ref);
2108
2109 if (context != 0 && context != current_function_decl)
2110 DECL_NONLOCAL (ref) = 1;
2111 }
2112 /* C99 6.7.4p3: An inline definition of a function with external
2113 linkage ... shall not contain a reference to an identifier with
2114 internal linkage. */
2115 else if (current_function_decl != 0
2116 && DECL_DECLARED_INLINE_P (current_function_decl)
2117 && DECL_EXTERNAL (current_function_decl)
2118 && VAR_OR_FUNCTION_DECL_P (ref)
2119 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref))
2120 && ! TREE_PUBLIC (ref))
2121 pedwarn ("%H%qD is static but used in inline function %qD "
2122 "which is not static", &loc, ref, current_function_decl);
2123
2124 return ref;
2125 }
2126
2127 /* Record details of decls possibly used inside sizeof or typeof. */
2128 struct maybe_used_decl
2129 {
2130 /* The decl. */
2131 tree decl;
2132 /* The level seen at (in_sizeof + in_typeof). */
2133 int level;
2134 /* The next one at this level or above, or NULL. */
2135 struct maybe_used_decl *next;
2136 };
2137
2138 static struct maybe_used_decl *maybe_used_decls;
2139
2140 /* Record that DECL, an undefined static function reference seen
2141 inside sizeof or typeof, might be used if the operand of sizeof is
2142 a VLA type or the operand of typeof is a variably modified
2143 type. */
2144
2145 static void
2146 record_maybe_used_decl (tree decl)
2147 {
2148 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2149 t->decl = decl;
2150 t->level = in_sizeof + in_typeof;
2151 t->next = maybe_used_decls;
2152 maybe_used_decls = t;
2153 }
2154
2155 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2156 USED is false, just discard them. If it is true, mark them used
2157 (if no longer inside sizeof or typeof) or move them to the next
2158 level up (if still inside sizeof or typeof). */
2159
2160 void
2161 pop_maybe_used (bool used)
2162 {
2163 struct maybe_used_decl *p = maybe_used_decls;
2164 int cur_level = in_sizeof + in_typeof;
2165 while (p && p->level > cur_level)
2166 {
2167 if (used)
2168 {
2169 if (cur_level == 0)
2170 C_DECL_USED (p->decl) = 1;
2171 else
2172 p->level = cur_level;
2173 }
2174 p = p->next;
2175 }
2176 if (!used || cur_level == 0)
2177 maybe_used_decls = p;
2178 }
2179
2180 /* Return the result of sizeof applied to EXPR. */
2181
2182 struct c_expr
2183 c_expr_sizeof_expr (struct c_expr expr)
2184 {
2185 struct c_expr ret;
2186 if (expr.value == error_mark_node)
2187 {
2188 ret.value = error_mark_node;
2189 ret.original_code = ERROR_MARK;
2190 pop_maybe_used (false);
2191 }
2192 else
2193 {
2194 ret.value = c_sizeof (TREE_TYPE (expr.value));
2195 ret.original_code = ERROR_MARK;
2196 if (c_vla_type_p (TREE_TYPE (expr.value)))
2197 {
2198 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2199 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2200 }
2201 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2202 }
2203 return ret;
2204 }
2205
2206 /* Return the result of sizeof applied to T, a structure for the type
2207 name passed to sizeof (rather than the type itself). */
2208
2209 struct c_expr
2210 c_expr_sizeof_type (struct c_type_name *t)
2211 {
2212 tree type;
2213 struct c_expr ret;
2214 type = groktypename (t);
2215 ret.value = c_sizeof (type);
2216 ret.original_code = ERROR_MARK;
2217 pop_maybe_used (type != error_mark_node
2218 ? C_TYPE_VARIABLE_SIZE (type) : false);
2219 return ret;
2220 }
2221
2222 /* Build a function call to function FUNCTION with parameters PARAMS.
2223 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2224 TREE_VALUE of each node is a parameter-expression.
2225 FUNCTION's data type may be a function type or a pointer-to-function. */
2226
2227 tree
2228 build_function_call (tree function, tree params)
2229 {
2230 tree fntype, fundecl = 0;
2231 tree coerced_params;
2232 tree name = NULL_TREE, result;
2233 tree tem;
2234
2235 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2236 STRIP_TYPE_NOPS (function);
2237
2238 /* Convert anything with function type to a pointer-to-function. */
2239 if (TREE_CODE (function) == FUNCTION_DECL)
2240 {
2241 /* Implement type-directed function overloading for builtins.
2242 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2243 handle all the type checking. The result is a complete expression
2244 that implements this function call. */
2245 tem = resolve_overloaded_builtin (function, params);
2246 if (tem)
2247 return tem;
2248
2249 name = DECL_NAME (function);
2250 fundecl = function;
2251 }
2252 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2253 function = function_to_pointer_conversion (function);
2254
2255 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2256 expressions, like those used for ObjC messenger dispatches. */
2257 function = objc_rewrite_function_call (function, params);
2258
2259 fntype = TREE_TYPE (function);
2260
2261 if (TREE_CODE (fntype) == ERROR_MARK)
2262 return error_mark_node;
2263
2264 if (!(TREE_CODE (fntype) == POINTER_TYPE
2265 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2266 {
2267 error ("called object %qE is not a function", function);
2268 return error_mark_node;
2269 }
2270
2271 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2272 current_function_returns_abnormally = 1;
2273
2274 /* fntype now gets the type of function pointed to. */
2275 fntype = TREE_TYPE (fntype);
2276
2277 /* Check that the function is called through a compatible prototype.
2278 If it is not, replace the call by a trap, wrapped up in a compound
2279 expression if necessary. This has the nice side-effect to prevent
2280 the tree-inliner from generating invalid assignment trees which may
2281 blow up in the RTL expander later. */
2282 if ((TREE_CODE (function) == NOP_EXPR
2283 || TREE_CODE (function) == CONVERT_EXPR)
2284 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2285 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2286 && !comptypes (fntype, TREE_TYPE (tem)))
2287 {
2288 tree return_type = TREE_TYPE (fntype);
2289 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2290 NULL_TREE);
2291
2292 /* This situation leads to run-time undefined behavior. We can't,
2293 therefore, simply error unless we can prove that all possible
2294 executions of the program must execute the code. */
2295 warning (0, "function called through a non-compatible type");
2296
2297 /* We can, however, treat "undefined" any way we please.
2298 Call abort to encourage the user to fix the program. */
2299 inform ("if this code is reached, the program will abort");
2300
2301 if (VOID_TYPE_P (return_type))
2302 return trap;
2303 else
2304 {
2305 tree rhs;
2306
2307 if (AGGREGATE_TYPE_P (return_type))
2308 rhs = build_compound_literal (return_type,
2309 build_constructor (return_type, 0));
2310 else
2311 rhs = fold_convert (return_type, integer_zero_node);
2312
2313 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2314 }
2315 }
2316
2317 /* Convert the parameters to the types declared in the
2318 function prototype, or apply default promotions. */
2319
2320 coerced_params
2321 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl);
2322
2323 if (coerced_params == error_mark_node)
2324 return error_mark_node;
2325
2326 /* Check that the arguments to the function are valid. */
2327
2328 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2329 TYPE_ARG_TYPES (fntype));
2330
2331 if (require_constant_value)
2332 {
2333 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype),
2334 function, coerced_params, NULL_TREE);
2335
2336 if (TREE_CONSTANT (result)
2337 && (name == NULL_TREE
2338 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2339 pedwarn_init ("initializer element is not constant");
2340 }
2341 else
2342 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype),
2343 function, coerced_params, NULL_TREE);
2344
2345 if (VOID_TYPE_P (TREE_TYPE (result)))
2346 return result;
2347 return require_complete_type (result);
2348 }
2349 \f
2350 /* Convert the argument expressions in the list VALUES
2351 to the types in the list TYPELIST. The result is a list of converted
2352 argument expressions, unless there are too few arguments in which
2353 case it is error_mark_node.
2354
2355 If TYPELIST is exhausted, or when an element has NULL as its type,
2356 perform the default conversions.
2357
2358 PARMLIST is the chain of parm decls for the function being called.
2359 It may be 0, if that info is not available.
2360 It is used only for generating error messages.
2361
2362 FUNCTION is a tree for the called function. It is used only for
2363 error messages, where it is formatted with %qE.
2364
2365 This is also where warnings about wrong number of args are generated.
2366
2367 Both VALUES and the returned value are chains of TREE_LIST nodes
2368 with the elements of the list in the TREE_VALUE slots of those nodes. */
2369
2370 static tree
2371 convert_arguments (tree typelist, tree values, tree function, tree fundecl)
2372 {
2373 tree typetail, valtail;
2374 tree result = NULL;
2375 int parmnum;
2376 tree selector;
2377
2378 /* Change pointer to function to the function itself for
2379 diagnostics. */
2380 if (TREE_CODE (function) == ADDR_EXPR
2381 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2382 function = TREE_OPERAND (function, 0);
2383
2384 /* Handle an ObjC selector specially for diagnostics. */
2385 selector = objc_message_selector ();
2386
2387 /* Scan the given expressions and types, producing individual
2388 converted arguments and pushing them on RESULT in reverse order. */
2389
2390 for (valtail = values, typetail = typelist, parmnum = 0;
2391 valtail;
2392 valtail = TREE_CHAIN (valtail), parmnum++)
2393 {
2394 tree type = typetail ? TREE_VALUE (typetail) : 0;
2395 tree val = TREE_VALUE (valtail);
2396 tree rname = function;
2397 int argnum = parmnum + 1;
2398 const char *invalid_func_diag;
2399
2400 if (type == void_type_node)
2401 {
2402 error ("too many arguments to function %qE", function);
2403 break;
2404 }
2405
2406 if (selector && argnum > 2)
2407 {
2408 rname = selector;
2409 argnum -= 2;
2410 }
2411
2412 STRIP_TYPE_NOPS (val);
2413
2414 val = require_complete_type (val);
2415
2416 if (type != 0)
2417 {
2418 /* Formal parm type is specified by a function prototype. */
2419 tree parmval;
2420
2421 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2422 {
2423 error ("type of formal parameter %d is incomplete", parmnum + 1);
2424 parmval = val;
2425 }
2426 else
2427 {
2428 /* Optionally warn about conversions that
2429 differ from the default conversions. */
2430 if (warn_traditional_conversion || warn_traditional)
2431 {
2432 unsigned int formal_prec = TYPE_PRECISION (type);
2433
2434 if (INTEGRAL_TYPE_P (type)
2435 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2436 warning (0, "passing argument %d of %qE as integer "
2437 "rather than floating due to prototype",
2438 argnum, rname);
2439 if (INTEGRAL_TYPE_P (type)
2440 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2441 warning (0, "passing argument %d of %qE as integer "
2442 "rather than complex due to prototype",
2443 argnum, rname);
2444 else if (TREE_CODE (type) == COMPLEX_TYPE
2445 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2446 warning (0, "passing argument %d of %qE as complex "
2447 "rather than floating due to prototype",
2448 argnum, rname);
2449 else if (TREE_CODE (type) == REAL_TYPE
2450 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2451 warning (0, "passing argument %d of %qE as floating "
2452 "rather than integer due to prototype",
2453 argnum, rname);
2454 else if (TREE_CODE (type) == COMPLEX_TYPE
2455 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2456 warning (0, "passing argument %d of %qE as complex "
2457 "rather than integer due to prototype",
2458 argnum, rname);
2459 else if (TREE_CODE (type) == REAL_TYPE
2460 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2461 warning (0, "passing argument %d of %qE as floating "
2462 "rather than complex due to prototype",
2463 argnum, rname);
2464 /* ??? At some point, messages should be written about
2465 conversions between complex types, but that's too messy
2466 to do now. */
2467 else if (TREE_CODE (type) == REAL_TYPE
2468 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2469 {
2470 /* Warn if any argument is passed as `float',
2471 since without a prototype it would be `double'. */
2472 if (formal_prec == TYPE_PRECISION (float_type_node)
2473 && type != dfloat32_type_node)
2474 warning (0, "passing argument %d of %qE as %<float%> "
2475 "rather than %<double%> due to prototype",
2476 argnum, rname);
2477
2478 /* Warn if mismatch between argument and prototype
2479 for decimal float types. Warn of conversions with
2480 binary float types and of precision narrowing due to
2481 prototype. */
2482 else if (type != TREE_TYPE (val)
2483 && (type == dfloat32_type_node
2484 || type == dfloat64_type_node
2485 || type == dfloat128_type_node
2486 || TREE_TYPE (val) == dfloat32_type_node
2487 || TREE_TYPE (val) == dfloat64_type_node
2488 || TREE_TYPE (val) == dfloat128_type_node)
2489 && (formal_prec
2490 <= TYPE_PRECISION (TREE_TYPE (val))
2491 || (type == dfloat128_type_node
2492 && (TREE_TYPE (val)
2493 != dfloat64_type_node
2494 && (TREE_TYPE (val)
2495 != dfloat32_type_node)))
2496 || (type == dfloat64_type_node
2497 && (TREE_TYPE (val)
2498 != dfloat32_type_node))))
2499 warning (0, "passing argument %d of %qE as %qT "
2500 "rather than %qT due to prototype",
2501 argnum, rname, type, TREE_TYPE (val));
2502
2503 }
2504 /* Detect integer changing in width or signedness.
2505 These warnings are only activated with
2506 -Wtraditional-conversion, not with -Wtraditional. */
2507 else if (warn_traditional_conversion && INTEGRAL_TYPE_P (type)
2508 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2509 {
2510 tree would_have_been = default_conversion (val);
2511 tree type1 = TREE_TYPE (would_have_been);
2512
2513 if (TREE_CODE (type) == ENUMERAL_TYPE
2514 && (TYPE_MAIN_VARIANT (type)
2515 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2516 /* No warning if function asks for enum
2517 and the actual arg is that enum type. */
2518 ;
2519 else if (formal_prec != TYPE_PRECISION (type1))
2520 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2521 "with different width due to prototype",
2522 argnum, rname);
2523 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2524 ;
2525 /* Don't complain if the formal parameter type
2526 is an enum, because we can't tell now whether
2527 the value was an enum--even the same enum. */
2528 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2529 ;
2530 else if (TREE_CODE (val) == INTEGER_CST
2531 && int_fits_type_p (val, type))
2532 /* Change in signedness doesn't matter
2533 if a constant value is unaffected. */
2534 ;
2535 /* If the value is extended from a narrower
2536 unsigned type, it doesn't matter whether we
2537 pass it as signed or unsigned; the value
2538 certainly is the same either way. */
2539 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2540 && TYPE_UNSIGNED (TREE_TYPE (val)))
2541 ;
2542 else if (TYPE_UNSIGNED (type))
2543 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2544 "as unsigned due to prototype",
2545 argnum, rname);
2546 else
2547 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2548 "as signed due to prototype", argnum, rname);
2549 }
2550 }
2551
2552 parmval = convert_for_assignment (type, val, ic_argpass,
2553 fundecl, function,
2554 parmnum + 1);
2555
2556 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2557 && INTEGRAL_TYPE_P (type)
2558 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2559 parmval = default_conversion (parmval);
2560 }
2561 result = tree_cons (NULL_TREE, parmval, result);
2562 }
2563 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2564 && (TYPE_PRECISION (TREE_TYPE (val))
2565 < TYPE_PRECISION (double_type_node))
2566 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2567 /* Convert `float' to `double'. */
2568 result = tree_cons (NULL_TREE, convert (double_type_node, val), result);
2569 else if ((invalid_func_diag =
2570 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2571 {
2572 error (invalid_func_diag);
2573 return error_mark_node;
2574 }
2575 else
2576 /* Convert `short' and `char' to full-size `int'. */
2577 result = tree_cons (NULL_TREE, default_conversion (val), result);
2578
2579 if (typetail)
2580 typetail = TREE_CHAIN (typetail);
2581 }
2582
2583 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2584 {
2585 error ("too few arguments to function %qE", function);
2586 return error_mark_node;
2587 }
2588
2589 return nreverse (result);
2590 }
2591 \f
2592 /* This is the entry point used by the parser to build unary operators
2593 in the input. CODE, a tree_code, specifies the unary operator, and
2594 ARG is the operand. For unary plus, the C parser currently uses
2595 CONVERT_EXPR for code. */
2596
2597 struct c_expr
2598 parser_build_unary_op (enum tree_code code, struct c_expr arg)
2599 {
2600 struct c_expr result;
2601
2602 result.original_code = ERROR_MARK;
2603 result.value = build_unary_op (code, arg.value, 0);
2604
2605 if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value))
2606 overflow_warning (result.value);
2607
2608 return result;
2609 }
2610
2611 /* This is the entry point used by the parser to build binary operators
2612 in the input. CODE, a tree_code, specifies the binary operator, and
2613 ARG1 and ARG2 are the operands. In addition to constructing the
2614 expression, we check for operands that were written with other binary
2615 operators in a way that is likely to confuse the user. */
2616
2617 struct c_expr
2618 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2619 struct c_expr arg2)
2620 {
2621 struct c_expr result;
2622
2623 enum tree_code code1 = arg1.original_code;
2624 enum tree_code code2 = arg2.original_code;
2625
2626 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2627 result.original_code = code;
2628
2629 if (TREE_CODE (result.value) == ERROR_MARK)
2630 return result;
2631
2632 /* Check for cases such as x+y<<z which users are likely
2633 to misinterpret. */
2634 if (warn_parentheses)
2635 warn_about_parentheses (code, code1, code2);
2636
2637 /* Warn about comparisons against string literals, with the exception
2638 of testing for equality or inequality of a string literal with NULL. */
2639 if (code == EQ_EXPR || code == NE_EXPR)
2640 {
2641 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2642 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2643 warning (OPT_Wstring_literal_comparison,
2644 "comparison with string literal");
2645 }
2646 else if (TREE_CODE_CLASS (code) == tcc_comparison
2647 && (code1 == STRING_CST || code2 == STRING_CST))
2648 warning (OPT_Wstring_literal_comparison,
2649 "comparison with string literal");
2650
2651 if (TREE_OVERFLOW_P (result.value)
2652 && !TREE_OVERFLOW_P (arg1.value)
2653 && !TREE_OVERFLOW_P (arg2.value))
2654 overflow_warning (result.value);
2655
2656 return result;
2657 }
2658 \f
2659 /* Return a tree for the difference of pointers OP0 and OP1.
2660 The resulting tree has type int. */
2661
2662 static tree
2663 pointer_diff (tree op0, tree op1)
2664 {
2665 tree restype = ptrdiff_type_node;
2666
2667 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2668 tree con0, con1, lit0, lit1;
2669 tree orig_op1 = op1;
2670
2671 if (pedantic || warn_pointer_arith)
2672 {
2673 if (TREE_CODE (target_type) == VOID_TYPE)
2674 pedwarn ("pointer of type %<void *%> used in subtraction");
2675 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2676 pedwarn ("pointer to a function used in subtraction");
2677 }
2678
2679 /* If the conversion to ptrdiff_type does anything like widening or
2680 converting a partial to an integral mode, we get a convert_expression
2681 that is in the way to do any simplifications.
2682 (fold-const.c doesn't know that the extra bits won't be needed.
2683 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2684 different mode in place.)
2685 So first try to find a common term here 'by hand'; we want to cover
2686 at least the cases that occur in legal static initializers. */
2687 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR)
2688 && (TYPE_PRECISION (TREE_TYPE (op0))
2689 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2690 con0 = TREE_OPERAND (op0, 0);
2691 else
2692 con0 = op0;
2693 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR)
2694 && (TYPE_PRECISION (TREE_TYPE (op1))
2695 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2696 con1 = TREE_OPERAND (op1, 0);
2697 else
2698 con1 = op1;
2699
2700 if (TREE_CODE (con0) == PLUS_EXPR)
2701 {
2702 lit0 = TREE_OPERAND (con0, 1);
2703 con0 = TREE_OPERAND (con0, 0);
2704 }
2705 else
2706 lit0 = integer_zero_node;
2707
2708 if (TREE_CODE (con1) == PLUS_EXPR)
2709 {
2710 lit1 = TREE_OPERAND (con1, 1);
2711 con1 = TREE_OPERAND (con1, 0);
2712 }
2713 else
2714 lit1 = integer_zero_node;
2715
2716 if (operand_equal_p (con0, con1, 0))
2717 {
2718 op0 = lit0;
2719 op1 = lit1;
2720 }
2721
2722
2723 /* First do the subtraction as integers;
2724 then drop through to build the divide operator.
2725 Do not do default conversions on the minus operator
2726 in case restype is a short type. */
2727
2728 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2729 convert (restype, op1), 0);
2730 /* This generates an error if op1 is pointer to incomplete type. */
2731 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2732 error ("arithmetic on pointer to an incomplete type");
2733
2734 /* This generates an error if op0 is pointer to incomplete type. */
2735 op1 = c_size_in_bytes (target_type);
2736
2737 /* Divide by the size, in easiest possible way. */
2738 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2739 }
2740 \f
2741 /* Construct and perhaps optimize a tree representation
2742 for a unary operation. CODE, a tree_code, specifies the operation
2743 and XARG is the operand.
2744 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2745 the default promotions (such as from short to int).
2746 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2747 allows non-lvalues; this is only used to handle conversion of non-lvalue
2748 arrays to pointers in C99. */
2749
2750 tree
2751 build_unary_op (enum tree_code code, tree xarg, int flag)
2752 {
2753 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2754 tree arg = xarg;
2755 tree argtype = 0;
2756 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2757 tree val;
2758 int noconvert = flag;
2759 const char *invalid_op_diag;
2760
2761 if (typecode == ERROR_MARK)
2762 return error_mark_node;
2763 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2764 typecode = INTEGER_TYPE;
2765
2766 if ((invalid_op_diag
2767 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2768 {
2769 error (invalid_op_diag);
2770 return error_mark_node;
2771 }
2772
2773 switch (code)
2774 {
2775 case CONVERT_EXPR:
2776 /* This is used for unary plus, because a CONVERT_EXPR
2777 is enough to prevent anybody from looking inside for
2778 associativity, but won't generate any code. */
2779 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2780 || typecode == COMPLEX_TYPE
2781 || typecode == VECTOR_TYPE))
2782 {
2783 error ("wrong type argument to unary plus");
2784 return error_mark_node;
2785 }
2786 else if (!noconvert)
2787 arg = default_conversion (arg);
2788 arg = non_lvalue (arg);
2789 break;
2790
2791 case NEGATE_EXPR:
2792 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2793 || typecode == COMPLEX_TYPE
2794 || typecode == VECTOR_TYPE))
2795 {
2796 error ("wrong type argument to unary minus");
2797 return error_mark_node;
2798 }
2799 else if (!noconvert)
2800 arg = default_conversion (arg);
2801 break;
2802
2803 case BIT_NOT_EXPR:
2804 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE)
2805 {
2806 if (!noconvert)
2807 arg = default_conversion (arg);
2808 }
2809 else if (typecode == COMPLEX_TYPE)
2810 {
2811 code = CONJ_EXPR;
2812 if (pedantic)
2813 pedwarn ("ISO C does not support %<~%> for complex conjugation");
2814 if (!noconvert)
2815 arg = default_conversion (arg);
2816 }
2817 else
2818 {
2819 error ("wrong type argument to bit-complement");
2820 return error_mark_node;
2821 }
2822 break;
2823
2824 case ABS_EXPR:
2825 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2826 {
2827 error ("wrong type argument to abs");
2828 return error_mark_node;
2829 }
2830 else if (!noconvert)
2831 arg = default_conversion (arg);
2832 break;
2833
2834 case CONJ_EXPR:
2835 /* Conjugating a real value is a no-op, but allow it anyway. */
2836 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2837 || typecode == COMPLEX_TYPE))
2838 {
2839 error ("wrong type argument to conjugation");
2840 return error_mark_node;
2841 }
2842 else if (!noconvert)
2843 arg = default_conversion (arg);
2844 break;
2845
2846 case TRUTH_NOT_EXPR:
2847 if (typecode != INTEGER_TYPE
2848 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2849 && typecode != COMPLEX_TYPE)
2850 {
2851 error ("wrong type argument to unary exclamation mark");
2852 return error_mark_node;
2853 }
2854 arg = c_objc_common_truthvalue_conversion (arg);
2855 return invert_truthvalue (arg);
2856
2857 case REALPART_EXPR:
2858 if (TREE_CODE (arg) == COMPLEX_CST)
2859 return TREE_REALPART (arg);
2860 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2861 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2862 else
2863 return arg;
2864
2865 case IMAGPART_EXPR:
2866 if (TREE_CODE (arg) == COMPLEX_CST)
2867 return TREE_IMAGPART (arg);
2868 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2869 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2870 else
2871 return convert (TREE_TYPE (arg), integer_zero_node);
2872
2873 case PREINCREMENT_EXPR:
2874 case POSTINCREMENT_EXPR:
2875 case PREDECREMENT_EXPR:
2876 case POSTDECREMENT_EXPR:
2877
2878 /* Increment or decrement the real part of the value,
2879 and don't change the imaginary part. */
2880 if (typecode == COMPLEX_TYPE)
2881 {
2882 tree real, imag;
2883
2884 if (pedantic)
2885 pedwarn ("ISO C does not support %<++%> and %<--%>"
2886 " on complex types");
2887
2888 arg = stabilize_reference (arg);
2889 real = build_unary_op (REALPART_EXPR, arg, 1);
2890 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2891 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
2892 build_unary_op (code, real, 1), imag);
2893 }
2894
2895 /* Report invalid types. */
2896
2897 if (typecode != POINTER_TYPE
2898 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2899 {
2900 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2901 error ("wrong type argument to increment");
2902 else
2903 error ("wrong type argument to decrement");
2904
2905 return error_mark_node;
2906 }
2907
2908 {
2909 tree inc;
2910 tree result_type = TREE_TYPE (arg);
2911
2912 arg = get_unwidened (arg, 0);
2913 argtype = TREE_TYPE (arg);
2914
2915 /* Compute the increment. */
2916
2917 if (typecode == POINTER_TYPE)
2918 {
2919 /* If pointer target is an undefined struct,
2920 we just cannot know how to do the arithmetic. */
2921 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2922 {
2923 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2924 error ("increment of pointer to unknown structure");
2925 else
2926 error ("decrement of pointer to unknown structure");
2927 }
2928 else if ((pedantic || warn_pointer_arith)
2929 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2930 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2931 {
2932 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2933 pedwarn ("wrong type argument to increment");
2934 else
2935 pedwarn ("wrong type argument to decrement");
2936 }
2937
2938 inc = c_size_in_bytes (TREE_TYPE (result_type));
2939 }
2940 else
2941 inc = integer_one_node;
2942
2943 inc = convert (argtype, inc);
2944
2945 /* Complain about anything else that is not a true lvalue. */
2946 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
2947 || code == POSTINCREMENT_EXPR)
2948 ? lv_increment
2949 : lv_decrement)))
2950 return error_mark_node;
2951
2952 /* Report a read-only lvalue. */
2953 if (TREE_READONLY (arg))
2954 {
2955 readonly_error (arg,
2956 ((code == PREINCREMENT_EXPR
2957 || code == POSTINCREMENT_EXPR)
2958 ? lv_increment : lv_decrement));
2959 return error_mark_node;
2960 }
2961
2962 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2963 val = boolean_increment (code, arg);
2964 else
2965 val = build2 (code, TREE_TYPE (arg), arg, inc);
2966 TREE_SIDE_EFFECTS (val) = 1;
2967 val = convert (result_type, val);
2968 if (TREE_CODE (val) != code)
2969 TREE_NO_WARNING (val) = 1;
2970 return val;
2971 }
2972
2973 case ADDR_EXPR:
2974 /* Note that this operation never does default_conversion. */
2975
2976 /* Let &* cancel out to simplify resulting code. */
2977 if (TREE_CODE (arg) == INDIRECT_REF)
2978 {
2979 /* Don't let this be an lvalue. */
2980 if (lvalue_p (TREE_OPERAND (arg, 0)))
2981 return non_lvalue (TREE_OPERAND (arg, 0));
2982 return TREE_OPERAND (arg, 0);
2983 }
2984
2985 /* For &x[y], return x+y */
2986 if (TREE_CODE (arg) == ARRAY_REF)
2987 {
2988 tree op0 = TREE_OPERAND (arg, 0);
2989 if (!c_mark_addressable (op0))
2990 return error_mark_node;
2991 return build_binary_op (PLUS_EXPR,
2992 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
2993 ? array_to_pointer_conversion (op0)
2994 : op0),
2995 TREE_OPERAND (arg, 1), 1);
2996 }
2997
2998 /* Anything not already handled and not a true memory reference
2999 or a non-lvalue array is an error. */
3000 else if (typecode != FUNCTION_TYPE && !flag
3001 && !lvalue_or_else (arg, lv_addressof))
3002 return error_mark_node;
3003
3004 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3005 argtype = TREE_TYPE (arg);
3006
3007 /* If the lvalue is const or volatile, merge that into the type
3008 to which the address will point. Note that you can't get a
3009 restricted pointer by taking the address of something, so we
3010 only have to deal with `const' and `volatile' here. */
3011 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3012 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3013 argtype = c_build_type_variant (argtype,
3014 TREE_READONLY (arg),
3015 TREE_THIS_VOLATILE (arg));
3016
3017 if (!c_mark_addressable (arg))
3018 return error_mark_node;
3019
3020 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3021 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3022
3023 argtype = build_pointer_type (argtype);
3024
3025 /* ??? Cope with user tricks that amount to offsetof. Delete this
3026 when we have proper support for integer constant expressions. */
3027 val = get_base_address (arg);
3028 if (val && TREE_CODE (val) == INDIRECT_REF
3029 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3030 {
3031 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1;
3032
3033 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3034 return fold_build2 (PLUS_EXPR, argtype, op0, op1);
3035 }
3036
3037 val = build1 (ADDR_EXPR, argtype, arg);
3038
3039 return val;
3040
3041 default:
3042 gcc_unreachable ();
3043 }
3044
3045 if (argtype == 0)
3046 argtype = TREE_TYPE (arg);
3047 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3048 : fold_build1 (code, argtype, arg);
3049 }
3050
3051 /* Return nonzero if REF is an lvalue valid for this language.
3052 Lvalues can be assigned, unless their type has TYPE_READONLY.
3053 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3054
3055 static int
3056 lvalue_p (tree ref)
3057 {
3058 enum tree_code code = TREE_CODE (ref);
3059
3060 switch (code)
3061 {
3062 case REALPART_EXPR:
3063 case IMAGPART_EXPR:
3064 case COMPONENT_REF:
3065 return lvalue_p (TREE_OPERAND (ref, 0));
3066
3067 case COMPOUND_LITERAL_EXPR:
3068 case STRING_CST:
3069 return 1;
3070
3071 case INDIRECT_REF:
3072 case ARRAY_REF:
3073 case VAR_DECL:
3074 case PARM_DECL:
3075 case RESULT_DECL:
3076 case ERROR_MARK:
3077 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3078 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3079
3080 case BIND_EXPR:
3081 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3082
3083 default:
3084 return 0;
3085 }
3086 }
3087 \f
3088 /* Give an error for storing in something that is 'const'. */
3089
3090 static void
3091 readonly_error (tree arg, enum lvalue_use use)
3092 {
3093 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3094 || use == lv_asm);
3095 /* Using this macro rather than (for example) arrays of messages
3096 ensures that all the format strings are checked at compile
3097 time. */
3098 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3099 : (use == lv_increment ? (I) \
3100 : (use == lv_decrement ? (D) : (AS))))
3101 if (TREE_CODE (arg) == COMPONENT_REF)
3102 {
3103 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3104 readonly_error (TREE_OPERAND (arg, 0), use);
3105 else
3106 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3107 G_("increment of read-only member %qD"),
3108 G_("decrement of read-only member %qD"),
3109 G_("read-only member %qD used as %<asm%> output")),
3110 TREE_OPERAND (arg, 1));
3111 }
3112 else if (TREE_CODE (arg) == VAR_DECL)
3113 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3114 G_("increment of read-only variable %qD"),
3115 G_("decrement of read-only variable %qD"),
3116 G_("read-only variable %qD used as %<asm%> output")),
3117 arg);
3118 else
3119 error (READONLY_MSG (G_("assignment of read-only location"),
3120 G_("increment of read-only location"),
3121 G_("decrement of read-only location"),
3122 G_("read-only location used as %<asm%> output")));
3123 }
3124
3125
3126 /* Return nonzero if REF is an lvalue valid for this language;
3127 otherwise, print an error message and return zero. USE says
3128 how the lvalue is being used and so selects the error message. */
3129
3130 static int
3131 lvalue_or_else (tree ref, enum lvalue_use use)
3132 {
3133 int win = lvalue_p (ref);
3134
3135 if (!win)
3136 lvalue_error (use);
3137
3138 return win;
3139 }
3140 \f
3141 /* Mark EXP saying that we need to be able to take the
3142 address of it; it should not be allocated in a register.
3143 Returns true if successful. */
3144
3145 bool
3146 c_mark_addressable (tree exp)
3147 {
3148 tree x = exp;
3149
3150 while (1)
3151 switch (TREE_CODE (x))
3152 {
3153 case COMPONENT_REF:
3154 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3155 {
3156 error
3157 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3158 return false;
3159 }
3160
3161 /* ... fall through ... */
3162
3163 case ADDR_EXPR:
3164 case ARRAY_REF:
3165 case REALPART_EXPR:
3166 case IMAGPART_EXPR:
3167 x = TREE_OPERAND (x, 0);
3168 break;
3169
3170 case COMPOUND_LITERAL_EXPR:
3171 case CONSTRUCTOR:
3172 TREE_ADDRESSABLE (x) = 1;
3173 return true;
3174
3175 case VAR_DECL:
3176 case CONST_DECL:
3177 case PARM_DECL:
3178 case RESULT_DECL:
3179 if (C_DECL_REGISTER (x)
3180 && DECL_NONLOCAL (x))
3181 {
3182 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3183 {
3184 error
3185 ("global register variable %qD used in nested function", x);
3186 return false;
3187 }
3188 pedwarn ("register variable %qD used in nested function", x);
3189 }
3190 else if (C_DECL_REGISTER (x))
3191 {
3192 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3193 error ("address of global register variable %qD requested", x);
3194 else
3195 error ("address of register variable %qD requested", x);
3196 return false;
3197 }
3198
3199 /* drops in */
3200 case FUNCTION_DECL:
3201 TREE_ADDRESSABLE (x) = 1;
3202 /* drops out */
3203 default:
3204 return true;
3205 }
3206 }
3207 \f
3208 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3209
3210 tree
3211 build_conditional_expr (tree ifexp, tree op1, tree op2)
3212 {
3213 tree type1;
3214 tree type2;
3215 enum tree_code code1;
3216 enum tree_code code2;
3217 tree result_type = NULL;
3218 tree orig_op1 = op1, orig_op2 = op2;
3219
3220 /* Promote both alternatives. */
3221
3222 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3223 op1 = default_conversion (op1);
3224 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3225 op2 = default_conversion (op2);
3226
3227 if (TREE_CODE (ifexp) == ERROR_MARK
3228 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3229 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3230 return error_mark_node;
3231
3232 type1 = TREE_TYPE (op1);
3233 code1 = TREE_CODE (type1);
3234 type2 = TREE_TYPE (op2);
3235 code2 = TREE_CODE (type2);
3236
3237 /* C90 does not permit non-lvalue arrays in conditional expressions.
3238 In C99 they will be pointers by now. */
3239 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3240 {
3241 error ("non-lvalue array in conditional expression");
3242 return error_mark_node;
3243 }
3244
3245 /* Quickly detect the usual case where op1 and op2 have the same type
3246 after promotion. */
3247 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3248 {
3249 if (type1 == type2)
3250 result_type = type1;
3251 else
3252 result_type = TYPE_MAIN_VARIANT (type1);
3253 }
3254 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3255 || code1 == COMPLEX_TYPE)
3256 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3257 || code2 == COMPLEX_TYPE))
3258 {
3259 result_type = c_common_type (type1, type2);
3260
3261 /* If -Wsign-compare, warn here if type1 and type2 have
3262 different signedness. We'll promote the signed to unsigned
3263 and later code won't know it used to be different.
3264 Do this check on the original types, so that explicit casts
3265 will be considered, but default promotions won't. */
3266 if (warn_sign_compare && !skip_evaluation)
3267 {
3268 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3269 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3270
3271 if (unsigned_op1 ^ unsigned_op2)
3272 {
3273 /* Do not warn if the result type is signed, since the
3274 signed type will only be chosen if it can represent
3275 all the values of the unsigned type. */
3276 if (!TYPE_UNSIGNED (result_type))
3277 /* OK */;
3278 /* Do not warn if the signed quantity is an unsuffixed
3279 integer literal (or some static constant expression
3280 involving such literals) and it is non-negative. */
3281 else if ((unsigned_op2 && tree_expr_nonnegative_p (op1))
3282 || (unsigned_op1 && tree_expr_nonnegative_p (op2)))
3283 /* OK */;
3284 else
3285 warning (0, "signed and unsigned type in conditional expression");
3286 }
3287 }
3288 }
3289 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3290 {
3291 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3292 pedwarn ("ISO C forbids conditional expr with only one void side");
3293 result_type = void_type_node;
3294 }
3295 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3296 {
3297 if (comp_target_types (type1, type2))
3298 result_type = common_pointer_type (type1, type2);
3299 else if (null_pointer_constant_p (orig_op1))
3300 result_type = qualify_type (type2, type1);
3301 else if (null_pointer_constant_p (orig_op2))
3302 result_type = qualify_type (type1, type2);
3303 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3304 {
3305 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3306 pedwarn ("ISO C forbids conditional expr between "
3307 "%<void *%> and function pointer");
3308 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3309 TREE_TYPE (type2)));
3310 }
3311 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3312 {
3313 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3314 pedwarn ("ISO C forbids conditional expr between "
3315 "%<void *%> and function pointer");
3316 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3317 TREE_TYPE (type1)));
3318 }
3319 else
3320 {
3321 pedwarn ("pointer type mismatch in conditional expression");
3322 result_type = build_pointer_type (void_type_node);
3323 }
3324 }
3325 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3326 {
3327 if (!null_pointer_constant_p (orig_op2))
3328 pedwarn ("pointer/integer type mismatch in conditional expression");
3329 else
3330 {
3331 op2 = null_pointer_node;
3332 }
3333 result_type = type1;
3334 }
3335 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3336 {
3337 if (!null_pointer_constant_p (orig_op1))
3338 pedwarn ("pointer/integer type mismatch in conditional expression");
3339 else
3340 {
3341 op1 = null_pointer_node;
3342 }
3343 result_type = type2;
3344 }
3345
3346 if (!result_type)
3347 {
3348 if (flag_cond_mismatch)
3349 result_type = void_type_node;
3350 else
3351 {
3352 error ("type mismatch in conditional expression");
3353 return error_mark_node;
3354 }
3355 }
3356
3357 /* Merge const and volatile flags of the incoming types. */
3358 result_type
3359 = build_type_variant (result_type,
3360 TREE_READONLY (op1) || TREE_READONLY (op2),
3361 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3362
3363 if (result_type != TREE_TYPE (op1))
3364 op1 = convert_and_check (result_type, op1);
3365 if (result_type != TREE_TYPE (op2))
3366 op2 = convert_and_check (result_type, op2);
3367
3368 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3369 }
3370 \f
3371 /* Return a compound expression that performs two expressions and
3372 returns the value of the second of them. */
3373
3374 tree
3375 build_compound_expr (tree expr1, tree expr2)
3376 {
3377 if (!TREE_SIDE_EFFECTS (expr1))
3378 {
3379 /* The left-hand operand of a comma expression is like an expression
3380 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3381 any side-effects, unless it was explicitly cast to (void). */
3382 if (warn_unused_value)
3383 {
3384 if (VOID_TYPE_P (TREE_TYPE (expr1))
3385 && (TREE_CODE (expr1) == NOP_EXPR
3386 || TREE_CODE (expr1) == CONVERT_EXPR))
3387 ; /* (void) a, b */
3388 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3389 && TREE_CODE (expr1) == COMPOUND_EXPR
3390 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR
3391 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR))
3392 ; /* (void) a, (void) b, c */
3393 else
3394 warning (0, "left-hand operand of comma expression has no effect");
3395 }
3396 }
3397
3398 /* With -Wunused, we should also warn if the left-hand operand does have
3399 side-effects, but computes a value which is not used. For example, in
3400 `foo() + bar(), baz()' the result of the `+' operator is not used,
3401 so we should issue a warning. */
3402 else if (warn_unused_value)
3403 warn_if_unused_value (expr1, input_location);
3404
3405 if (expr2 == error_mark_node)
3406 return error_mark_node;
3407
3408 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3409 }
3410
3411 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3412
3413 tree
3414 build_c_cast (tree type, tree expr)
3415 {
3416 tree value = expr;
3417
3418 if (type == error_mark_node || expr == error_mark_node)
3419 return error_mark_node;
3420
3421 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3422 only in <protocol> qualifications. But when constructing cast expressions,
3423 the protocols do matter and must be kept around. */
3424 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3425 return build1 (NOP_EXPR, type, expr);
3426
3427 type = TYPE_MAIN_VARIANT (type);
3428
3429 if (TREE_CODE (type) == ARRAY_TYPE)
3430 {
3431 error ("cast specifies array type");
3432 return error_mark_node;
3433 }
3434
3435 if (TREE_CODE (type) == FUNCTION_TYPE)
3436 {
3437 error ("cast specifies function type");
3438 return error_mark_node;
3439 }
3440
3441 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3442 {
3443 if (pedantic)
3444 {
3445 if (TREE_CODE (type) == RECORD_TYPE
3446 || TREE_CODE (type) == UNION_TYPE)
3447 pedwarn ("ISO C forbids casting nonscalar to the same type");
3448 }
3449 }
3450 else if (TREE_CODE (type) == UNION_TYPE)
3451 {
3452 tree field;
3453
3454 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3455 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3456 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3457 break;
3458
3459 if (field)
3460 {
3461 tree t;
3462
3463 if (pedantic)
3464 pedwarn ("ISO C forbids casts to union type");
3465 t = digest_init (type,
3466 build_constructor_single (type, field, value),
3467 true, 0);
3468 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3469 TREE_INVARIANT (t) = TREE_INVARIANT (value);
3470 return t;
3471 }
3472 error ("cast to union type from type not present in union");
3473 return error_mark_node;
3474 }
3475 else
3476 {
3477 tree otype, ovalue;
3478
3479 if (type == void_type_node)
3480 return build1 (CONVERT_EXPR, type, value);
3481
3482 otype = TREE_TYPE (value);
3483
3484 /* Optionally warn about potentially worrisome casts. */
3485
3486 if (warn_cast_qual
3487 && TREE_CODE (type) == POINTER_TYPE
3488 && TREE_CODE (otype) == POINTER_TYPE)
3489 {
3490 tree in_type = type;
3491 tree in_otype = otype;
3492 int added = 0;
3493 int discarded = 0;
3494
3495 /* Check that the qualifiers on IN_TYPE are a superset of
3496 the qualifiers of IN_OTYPE. The outermost level of
3497 POINTER_TYPE nodes is uninteresting and we stop as soon
3498 as we hit a non-POINTER_TYPE node on either type. */
3499 do
3500 {
3501 in_otype = TREE_TYPE (in_otype);
3502 in_type = TREE_TYPE (in_type);
3503
3504 /* GNU C allows cv-qualified function types. 'const'
3505 means the function is very pure, 'volatile' means it
3506 can't return. We need to warn when such qualifiers
3507 are added, not when they're taken away. */
3508 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3509 && TREE_CODE (in_type) == FUNCTION_TYPE)
3510 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3511 else
3512 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3513 }
3514 while (TREE_CODE (in_type) == POINTER_TYPE
3515 && TREE_CODE (in_otype) == POINTER_TYPE);
3516
3517 if (added)
3518 warning (0, "cast adds new qualifiers to function type");
3519
3520 if (discarded)
3521 /* There are qualifiers present in IN_OTYPE that are not
3522 present in IN_TYPE. */
3523 warning (0, "cast discards qualifiers from pointer target type");
3524 }
3525
3526 /* Warn about possible alignment problems. */
3527 if (STRICT_ALIGNMENT
3528 && TREE_CODE (type) == POINTER_TYPE
3529 && TREE_CODE (otype) == POINTER_TYPE
3530 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3531 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3532 /* Don't warn about opaque types, where the actual alignment
3533 restriction is unknown. */
3534 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3535 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3536 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3537 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3538 warning (OPT_Wcast_align,
3539 "cast increases required alignment of target type");
3540
3541 if (TREE_CODE (type) == INTEGER_TYPE
3542 && TREE_CODE (otype) == POINTER_TYPE
3543 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3544 /* Unlike conversion of integers to pointers, where the
3545 warning is disabled for converting constants because
3546 of cases such as SIG_*, warn about converting constant
3547 pointers to integers. In some cases it may cause unwanted
3548 sign extension, and a warning is appropriate. */
3549 warning (OPT_Wpointer_to_int_cast,
3550 "cast from pointer to integer of different size");
3551
3552 if (TREE_CODE (value) == CALL_EXPR
3553 && TREE_CODE (type) != TREE_CODE (otype))
3554 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3555 "to non-matching type %qT", otype, type);
3556
3557 if (TREE_CODE (type) == POINTER_TYPE
3558 && TREE_CODE (otype) == INTEGER_TYPE
3559 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3560 /* Don't warn about converting any constant. */
3561 && !TREE_CONSTANT (value))
3562 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3563 "of different size");
3564
3565 strict_aliasing_warning (otype, type, expr);
3566
3567 /* If pedantic, warn for conversions between function and object
3568 pointer types, except for converting a null pointer constant
3569 to function pointer type. */
3570 if (pedantic
3571 && TREE_CODE (type) == POINTER_TYPE
3572 && TREE_CODE (otype) == POINTER_TYPE
3573 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3574 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3575 pedwarn ("ISO C forbids conversion of function pointer to object pointer type");
3576
3577 if (pedantic
3578 && TREE_CODE (type) == POINTER_TYPE
3579 && TREE_CODE (otype) == POINTER_TYPE
3580 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3581 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3582 && !null_pointer_constant_p (value))
3583 pedwarn ("ISO C forbids conversion of object pointer to function pointer type");
3584
3585 ovalue = value;
3586 value = convert (type, value);
3587
3588 /* Ignore any integer overflow caused by the cast. */
3589 if (TREE_CODE (value) == INTEGER_CST)
3590 {
3591 if (CONSTANT_CLASS_P (ovalue) && TREE_OVERFLOW (ovalue))
3592 {
3593 if (!TREE_OVERFLOW (value))
3594 {
3595 /* Avoid clobbering a shared constant. */
3596 value = copy_node (value);
3597 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3598 }
3599 }
3600 else if (TREE_OVERFLOW (value))
3601 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3602 value = build_int_cst_wide (TREE_TYPE (value),
3603 TREE_INT_CST_LOW (value),
3604 TREE_INT_CST_HIGH (value));
3605 }
3606 }
3607
3608 /* Don't let a cast be an lvalue. */
3609 if (value == expr)
3610 value = non_lvalue (value);
3611
3612 return value;
3613 }
3614
3615 /* Interpret a cast of expression EXPR to type TYPE. */
3616 tree
3617 c_cast_expr (struct c_type_name *type_name, tree expr)
3618 {
3619 tree type;
3620 int saved_wsp = warn_strict_prototypes;
3621
3622 /* This avoids warnings about unprototyped casts on
3623 integers. E.g. "#define SIG_DFL (void(*)())0". */
3624 if (TREE_CODE (expr) == INTEGER_CST)
3625 warn_strict_prototypes = 0;
3626 type = groktypename (type_name);
3627 warn_strict_prototypes = saved_wsp;
3628
3629 return build_c_cast (type, expr);
3630 }
3631 \f
3632 /* Build an assignment expression of lvalue LHS from value RHS.
3633 MODIFYCODE is the code for a binary operator that we use
3634 to combine the old value of LHS with RHS to get the new value.
3635 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3636
3637 tree
3638 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3639 {
3640 tree result;
3641 tree newrhs;
3642 tree lhstype = TREE_TYPE (lhs);
3643 tree olhstype = lhstype;
3644
3645 /* Types that aren't fully specified cannot be used in assignments. */
3646 lhs = require_complete_type (lhs);
3647
3648 /* Avoid duplicate error messages from operands that had errors. */
3649 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3650 return error_mark_node;
3651
3652 if (!lvalue_or_else (lhs, lv_assign))
3653 return error_mark_node;
3654
3655 STRIP_TYPE_NOPS (rhs);
3656
3657 newrhs = rhs;
3658
3659 /* If a binary op has been requested, combine the old LHS value with the RHS
3660 producing the value we should actually store into the LHS. */
3661
3662 if (modifycode != NOP_EXPR)
3663 {
3664 lhs = stabilize_reference (lhs);
3665 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3666 }
3667
3668 /* Give an error for storing in something that is 'const'. */
3669
3670 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3671 || ((TREE_CODE (lhstype) == RECORD_TYPE
3672 || TREE_CODE (lhstype) == UNION_TYPE)
3673 && C_TYPE_FIELDS_READONLY (lhstype)))
3674 {
3675 readonly_error (lhs, lv_assign);
3676 return error_mark_node;
3677 }
3678
3679 /* If storing into a structure or union member,
3680 it has probably been given type `int'.
3681 Compute the type that would go with
3682 the actual amount of storage the member occupies. */
3683
3684 if (TREE_CODE (lhs) == COMPONENT_REF
3685 && (TREE_CODE (lhstype) == INTEGER_TYPE
3686 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3687 || TREE_CODE (lhstype) == REAL_TYPE
3688 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3689 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3690
3691 /* If storing in a field that is in actuality a short or narrower than one,
3692 we must store in the field in its actual type. */
3693
3694 if (lhstype != TREE_TYPE (lhs))
3695 {
3696 lhs = copy_node (lhs);
3697 TREE_TYPE (lhs) = lhstype;
3698 }
3699
3700 /* Convert new value to destination type. */
3701
3702 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3703 NULL_TREE, NULL_TREE, 0);
3704 if (TREE_CODE (newrhs) == ERROR_MARK)
3705 return error_mark_node;
3706
3707 /* Emit ObjC write barrier, if necessary. */
3708 if (c_dialect_objc () && flag_objc_gc)
3709 {
3710 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3711 if (result)
3712 return result;
3713 }
3714
3715 /* Scan operands. */
3716
3717 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3718 TREE_SIDE_EFFECTS (result) = 1;
3719
3720 /* If we got the LHS in a different type for storing in,
3721 convert the result back to the nominal type of LHS
3722 so that the value we return always has the same type
3723 as the LHS argument. */
3724
3725 if (olhstype == TREE_TYPE (result))
3726 return result;
3727 return convert_for_assignment (olhstype, result, ic_assign,
3728 NULL_TREE, NULL_TREE, 0);
3729 }
3730 \f
3731 /* Convert value RHS to type TYPE as preparation for an assignment
3732 to an lvalue of type TYPE.
3733 The real work of conversion is done by `convert'.
3734 The purpose of this function is to generate error messages
3735 for assignments that are not allowed in C.
3736 ERRTYPE says whether it is argument passing, assignment,
3737 initialization or return.
3738
3739 FUNCTION is a tree for the function being called.
3740 PARMNUM is the number of the argument, for printing in error messages. */
3741
3742 static tree
3743 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3744 tree fundecl, tree function, int parmnum)
3745 {
3746 enum tree_code codel = TREE_CODE (type);
3747 tree rhstype;
3748 enum tree_code coder;
3749 tree rname = NULL_TREE;
3750 bool objc_ok = false;
3751
3752 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3753 {
3754 tree selector;
3755 /* Change pointer to function to the function itself for
3756 diagnostics. */
3757 if (TREE_CODE (function) == ADDR_EXPR
3758 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3759 function = TREE_OPERAND (function, 0);
3760
3761 /* Handle an ObjC selector specially for diagnostics. */
3762 selector = objc_message_selector ();
3763 rname = function;
3764 if (selector && parmnum > 2)
3765 {
3766 rname = selector;
3767 parmnum -= 2;
3768 }
3769 }
3770
3771 /* This macro is used to emit diagnostics to ensure that all format
3772 strings are complete sentences, visible to gettext and checked at
3773 compile time. */
3774 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3775 do { \
3776 switch (errtype) \
3777 { \
3778 case ic_argpass: \
3779 pedwarn (AR, parmnum, rname); \
3780 break; \
3781 case ic_argpass_nonproto: \
3782 warning (0, AR, parmnum, rname); \
3783 break; \
3784 case ic_assign: \
3785 pedwarn (AS); \
3786 break; \
3787 case ic_init: \
3788 pedwarn (IN); \
3789 break; \
3790 case ic_return: \
3791 pedwarn (RE); \
3792 break; \
3793 default: \
3794 gcc_unreachable (); \
3795 } \
3796 } while (0)
3797
3798 STRIP_TYPE_NOPS (rhs);
3799
3800 if (optimize && TREE_CODE (rhs) == VAR_DECL
3801 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
3802 rhs = decl_constant_value_for_broken_optimization (rhs);
3803
3804 rhstype = TREE_TYPE (rhs);
3805 coder = TREE_CODE (rhstype);
3806
3807 if (coder == ERROR_MARK)
3808 return error_mark_node;
3809
3810 if (c_dialect_objc ())
3811 {
3812 int parmno;
3813
3814 switch (errtype)
3815 {
3816 case ic_return:
3817 parmno = 0;
3818 break;
3819
3820 case ic_assign:
3821 parmno = -1;
3822 break;
3823
3824 case ic_init:
3825 parmno = -2;
3826 break;
3827
3828 default:
3829 parmno = parmnum;
3830 break;
3831 }
3832
3833 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
3834 }
3835
3836 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
3837 return rhs;
3838
3839 if (coder == VOID_TYPE)
3840 {
3841 /* Except for passing an argument to an unprototyped function,
3842 this is a constraint violation. When passing an argument to
3843 an unprototyped function, it is compile-time undefined;
3844 making it a constraint in that case was rejected in
3845 DR#252. */
3846 error ("void value not ignored as it ought to be");
3847 return error_mark_node;
3848 }
3849 /* A type converts to a reference to it.
3850 This code doesn't fully support references, it's just for the
3851 special case of va_start and va_copy. */
3852 if (codel == REFERENCE_TYPE
3853 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
3854 {
3855 if (!lvalue_p (rhs))
3856 {
3857 error ("cannot pass rvalue to reference parameter");
3858 return error_mark_node;
3859 }
3860 if (!c_mark_addressable (rhs))
3861 return error_mark_node;
3862 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
3863
3864 /* We already know that these two types are compatible, but they
3865 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3866 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3867 likely to be va_list, a typedef to __builtin_va_list, which
3868 is different enough that it will cause problems later. */
3869 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
3870 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
3871
3872 rhs = build1 (NOP_EXPR, type, rhs);
3873 return rhs;
3874 }
3875 /* Some types can interconvert without explicit casts. */
3876 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
3877 && vector_types_convertible_p (type, TREE_TYPE (rhs), true))
3878 return convert (type, rhs);
3879 /* Arithmetic types all interconvert, and enum is treated like int. */
3880 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
3881 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
3882 || codel == BOOLEAN_TYPE)
3883 && (coder == INTEGER_TYPE || coder == REAL_TYPE
3884 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
3885 || coder == BOOLEAN_TYPE))
3886 return convert_and_check (type, rhs);
3887
3888 /* Conversion to a transparent union from its member types.
3889 This applies only to function arguments. */
3890 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
3891 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
3892 {
3893 tree memb, marginal_memb = NULL_TREE;
3894
3895 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
3896 {
3897 tree memb_type = TREE_TYPE (memb);
3898
3899 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
3900 TYPE_MAIN_VARIANT (rhstype)))
3901 break;
3902
3903 if (TREE_CODE (memb_type) != POINTER_TYPE)
3904 continue;
3905
3906 if (coder == POINTER_TYPE)
3907 {
3908 tree ttl = TREE_TYPE (memb_type);
3909 tree ttr = TREE_TYPE (rhstype);
3910
3911 /* Any non-function converts to a [const][volatile] void *
3912 and vice versa; otherwise, targets must be the same.
3913 Meanwhile, the lhs target must have all the qualifiers of
3914 the rhs. */
3915 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
3916 || comp_target_types (memb_type, rhstype))
3917 {
3918 /* If this type won't generate any warnings, use it. */
3919 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
3920 || ((TREE_CODE (ttr) == FUNCTION_TYPE
3921 && TREE_CODE (ttl) == FUNCTION_TYPE)
3922 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3923 == TYPE_QUALS (ttr))
3924 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3925 == TYPE_QUALS (ttl))))
3926 break;
3927
3928 /* Keep looking for a better type, but remember this one. */
3929 if (!marginal_memb)
3930 marginal_memb = memb;
3931 }
3932 }
3933
3934 /* Can convert integer zero to any pointer type. */
3935 if (null_pointer_constant_p (rhs))
3936 {
3937 rhs = null_pointer_node;
3938 break;
3939 }
3940 }
3941
3942 if (memb || marginal_memb)
3943 {
3944 if (!memb)
3945 {
3946 /* We have only a marginally acceptable member type;
3947 it needs a warning. */
3948 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
3949 tree ttr = TREE_TYPE (rhstype);
3950
3951 /* Const and volatile mean something different for function
3952 types, so the usual warnings are not appropriate. */
3953 if (TREE_CODE (ttr) == FUNCTION_TYPE
3954 && TREE_CODE (ttl) == FUNCTION_TYPE)
3955 {
3956 /* Because const and volatile on functions are
3957 restrictions that say the function will not do
3958 certain things, it is okay to use a const or volatile
3959 function where an ordinary one is wanted, but not
3960 vice-versa. */
3961 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
3962 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE "
3963 "makes qualified function "
3964 "pointer from unqualified"),
3965 G_("assignment makes qualified "
3966 "function pointer from "
3967 "unqualified"),
3968 G_("initialization makes qualified "
3969 "function pointer from "
3970 "unqualified"),
3971 G_("return makes qualified function "
3972 "pointer from unqualified"));
3973 }
3974 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
3975 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
3976 "qualifiers from pointer target type"),
3977 G_("assignment discards qualifiers "
3978 "from pointer target type"),
3979 G_("initialization discards qualifiers "
3980 "from pointer target type"),
3981 G_("return discards qualifiers from "
3982 "pointer target type"));
3983
3984 memb = marginal_memb;
3985 }
3986
3987 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl)))
3988 pedwarn ("ISO C prohibits argument conversion to union type");
3989
3990 return build_constructor_single (type, memb, rhs);
3991 }
3992 }
3993
3994 /* Conversions among pointers */
3995 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
3996 && (coder == codel))
3997 {
3998 tree ttl = TREE_TYPE (type);
3999 tree ttr = TREE_TYPE (rhstype);
4000 tree mvl = ttl;
4001 tree mvr = ttr;
4002 bool is_opaque_pointer;
4003 int target_cmp = 0; /* Cache comp_target_types () result. */
4004
4005 if (TREE_CODE (mvl) != ARRAY_TYPE)
4006 mvl = TYPE_MAIN_VARIANT (mvl);
4007 if (TREE_CODE (mvr) != ARRAY_TYPE)
4008 mvr = TYPE_MAIN_VARIANT (mvr);
4009 /* Opaque pointers are treated like void pointers. */
4010 is_opaque_pointer = (targetm.vector_opaque_p (type)
4011 || targetm.vector_opaque_p (rhstype))
4012 && TREE_CODE (ttl) == VECTOR_TYPE
4013 && TREE_CODE (ttr) == VECTOR_TYPE;
4014
4015 /* C++ does not allow the implicit conversion void* -> T*. However,
4016 for the purpose of reducing the number of false positives, we
4017 tolerate the special case of
4018
4019 int *p = NULL;
4020
4021 where NULL is typically defined in C to be '(void *) 0'. */
4022 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4023 warning (OPT_Wc___compat, "request for implicit conversion from "
4024 "%qT to %qT not permitted in C++", rhstype, type);
4025
4026 /* Check if the right-hand side has a format attribute but the
4027 left-hand side doesn't. */
4028 if (warn_missing_format_attribute
4029 && check_missing_format_attribute (type, rhstype))
4030 {
4031 switch (errtype)
4032 {
4033 case ic_argpass:
4034 case ic_argpass_nonproto:
4035 warning (OPT_Wmissing_format_attribute,
4036 "argument %d of %qE might be "
4037 "a candidate for a format attribute",
4038 parmnum, rname);
4039 break;
4040 case ic_assign:
4041 warning (OPT_Wmissing_format_attribute,
4042 "assignment left-hand side might be "
4043 "a candidate for a format attribute");
4044 break;
4045 case ic_init:
4046 warning (OPT_Wmissing_format_attribute,
4047 "initialization left-hand side might be "
4048 "a candidate for a format attribute");
4049 break;
4050 case ic_return:
4051 warning (OPT_Wmissing_format_attribute,
4052 "return type might be "
4053 "a candidate for a format attribute");
4054 break;
4055 default:
4056 gcc_unreachable ();
4057 }
4058 }
4059
4060 /* Any non-function converts to a [const][volatile] void *
4061 and vice versa; otherwise, targets must be the same.
4062 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4063 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4064 || (target_cmp = comp_target_types (type, rhstype))
4065 || is_opaque_pointer
4066 || (c_common_unsigned_type (mvl)
4067 == c_common_unsigned_type (mvr)))
4068 {
4069 if (pedantic
4070 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4071 ||
4072 (VOID_TYPE_P (ttr)
4073 && !null_pointer_constant_p (rhs)
4074 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4075 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of "
4076 "%qE between function pointer "
4077 "and %<void *%>"),
4078 G_("ISO C forbids assignment between "
4079 "function pointer and %<void *%>"),
4080 G_("ISO C forbids initialization between "
4081 "function pointer and %<void *%>"),
4082 G_("ISO C forbids return between function "
4083 "pointer and %<void *%>"));
4084 /* Const and volatile mean something different for function types,
4085 so the usual warnings are not appropriate. */
4086 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4087 && TREE_CODE (ttl) != FUNCTION_TYPE)
4088 {
4089 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4090 {
4091 /* Types differing only by the presence of the 'volatile'
4092 qualifier are acceptable if the 'volatile' has been added
4093 in by the Objective-C EH machinery. */
4094 if (!objc_type_quals_match (ttl, ttr))
4095 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4096 "qualifiers from pointer target type"),
4097 G_("assignment discards qualifiers "
4098 "from pointer target type"),
4099 G_("initialization discards qualifiers "
4100 "from pointer target type"),
4101 G_("return discards qualifiers from "
4102 "pointer target type"));
4103 }
4104 /* If this is not a case of ignoring a mismatch in signedness,
4105 no warning. */
4106 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4107 || target_cmp)
4108 ;
4109 /* If there is a mismatch, do warn. */
4110 else if (warn_pointer_sign)
4111 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument "
4112 "%d of %qE differ in signedness"),
4113 G_("pointer targets in assignment "
4114 "differ in signedness"),
4115 G_("pointer targets in initialization "
4116 "differ in signedness"),
4117 G_("pointer targets in return differ "
4118 "in signedness"));
4119 }
4120 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4121 && TREE_CODE (ttr) == FUNCTION_TYPE)
4122 {
4123 /* Because const and volatile on functions are restrictions
4124 that say the function will not do certain things,
4125 it is okay to use a const or volatile function
4126 where an ordinary one is wanted, but not vice-versa. */
4127 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4128 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4129 "qualified function pointer "
4130 "from unqualified"),
4131 G_("assignment makes qualified function "
4132 "pointer from unqualified"),
4133 G_("initialization makes qualified "
4134 "function pointer from unqualified"),
4135 G_("return makes qualified function "
4136 "pointer from unqualified"));
4137 }
4138 }
4139 else
4140 /* Avoid warning about the volatile ObjC EH puts on decls. */
4141 if (!objc_ok)
4142 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from "
4143 "incompatible pointer type"),
4144 G_("assignment from incompatible pointer type"),
4145 G_("initialization from incompatible "
4146 "pointer type"),
4147 G_("return from incompatible pointer type"));
4148
4149 return convert (type, rhs);
4150 }
4151 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4152 {
4153 /* ??? This should not be an error when inlining calls to
4154 unprototyped functions. */
4155 error ("invalid use of non-lvalue array");
4156 return error_mark_node;
4157 }
4158 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4159 {
4160 /* An explicit constant 0 can convert to a pointer,
4161 or one that results from arithmetic, even including
4162 a cast to integer type. */
4163 if (!null_pointer_constant_p (rhs))
4164 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4165 "pointer from integer without a cast"),
4166 G_("assignment makes pointer from integer "
4167 "without a cast"),
4168 G_("initialization makes pointer from "
4169 "integer without a cast"),
4170 G_("return makes pointer from integer "
4171 "without a cast"));
4172
4173 return convert (type, rhs);
4174 }
4175 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4176 {
4177 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer "
4178 "from pointer without a cast"),
4179 G_("assignment makes integer from pointer "
4180 "without a cast"),
4181 G_("initialization makes integer from pointer "
4182 "without a cast"),
4183 G_("return makes integer from pointer "
4184 "without a cast"));
4185 return convert (type, rhs);
4186 }
4187 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4188 return convert (type, rhs);
4189
4190 switch (errtype)
4191 {
4192 case ic_argpass:
4193 case ic_argpass_nonproto:
4194 /* ??? This should not be an error when inlining calls to
4195 unprototyped functions. */
4196 error ("incompatible type for argument %d of %qE", parmnum, rname);
4197 break;
4198 case ic_assign:
4199 error ("incompatible types in assignment");
4200 break;
4201 case ic_init:
4202 error ("incompatible types in initialization");
4203 break;
4204 case ic_return:
4205 error ("incompatible types in return");
4206 break;
4207 default:
4208 gcc_unreachable ();
4209 }
4210
4211 return error_mark_node;
4212 }
4213
4214 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
4215 is used for error and warning reporting and indicates which argument
4216 is being processed. */
4217
4218 tree
4219 c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum)
4220 {
4221 tree ret, type;
4222
4223 /* If FN was prototyped at the call site, the value has been converted
4224 already in convert_arguments.
4225 However, we might see a prototype now that was not in place when
4226 the function call was seen, so check that the VALUE actually matches
4227 PARM before taking an early exit. */
4228 if (!value
4229 || (TYPE_ARG_TYPES (TREE_TYPE (fn))
4230 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
4231 == TYPE_MAIN_VARIANT (TREE_TYPE (value)))))
4232 return value;
4233
4234 type = TREE_TYPE (parm);
4235 ret = convert_for_assignment (type, value,
4236 ic_argpass_nonproto, fn,
4237 fn, argnum);
4238 if (targetm.calls.promote_prototypes (TREE_TYPE (fn))
4239 && INTEGRAL_TYPE_P (type)
4240 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
4241 ret = default_conversion (ret);
4242 return ret;
4243 }
4244 \f
4245 /* If VALUE is a compound expr all of whose expressions are constant, then
4246 return its value. Otherwise, return error_mark_node.
4247
4248 This is for handling COMPOUND_EXPRs as initializer elements
4249 which is allowed with a warning when -pedantic is specified. */
4250
4251 static tree
4252 valid_compound_expr_initializer (tree value, tree endtype)
4253 {
4254 if (TREE_CODE (value) == COMPOUND_EXPR)
4255 {
4256 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4257 == error_mark_node)
4258 return error_mark_node;
4259 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4260 endtype);
4261 }
4262 else if (!initializer_constant_valid_p (value, endtype))
4263 return error_mark_node;
4264 else
4265 return value;
4266 }
4267 \f
4268 /* Perform appropriate conversions on the initial value of a variable,
4269 store it in the declaration DECL,
4270 and print any error messages that are appropriate.
4271 If the init is invalid, store an ERROR_MARK. */
4272
4273 void
4274 store_init_value (tree decl, tree init)
4275 {
4276 tree value, type;
4277
4278 /* If variable's type was invalidly declared, just ignore it. */
4279
4280 type = TREE_TYPE (decl);
4281 if (TREE_CODE (type) == ERROR_MARK)
4282 return;
4283
4284 /* Digest the specified initializer into an expression. */
4285
4286 value = digest_init (type, init, true, TREE_STATIC (decl));
4287
4288 /* Store the expression if valid; else report error. */
4289
4290 if (!in_system_header
4291 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4292 warning (OPT_Wtraditional, "traditional C rejects automatic "
4293 "aggregate initialization");
4294
4295 DECL_INITIAL (decl) = value;
4296
4297 /* ANSI wants warnings about out-of-range constant initializers. */
4298 STRIP_TYPE_NOPS (value);
4299 if (TREE_STATIC (decl))
4300 constant_expression_warning (value);
4301
4302 /* Check if we need to set array size from compound literal size. */
4303 if (TREE_CODE (type) == ARRAY_TYPE
4304 && TYPE_DOMAIN (type) == 0
4305 && value != error_mark_node)
4306 {
4307 tree inside_init = init;
4308
4309 STRIP_TYPE_NOPS (inside_init);
4310 inside_init = fold (inside_init);
4311
4312 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4313 {
4314 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4315
4316 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4317 {
4318 /* For int foo[] = (int [3]){1}; we need to set array size
4319 now since later on array initializer will be just the
4320 brace enclosed list of the compound literal. */
4321 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4322 TREE_TYPE (decl) = type;
4323 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4324 layout_type (type);
4325 layout_decl (cldecl, 0);
4326 }
4327 }
4328 }
4329 }
4330 \f
4331 /* Methods for storing and printing names for error messages. */
4332
4333 /* Implement a spelling stack that allows components of a name to be pushed
4334 and popped. Each element on the stack is this structure. */
4335
4336 struct spelling
4337 {
4338 int kind;
4339 union
4340 {
4341 unsigned HOST_WIDE_INT i;
4342 const char *s;
4343 } u;
4344 };
4345
4346 #define SPELLING_STRING 1
4347 #define SPELLING_MEMBER 2
4348 #define SPELLING_BOUNDS 3
4349
4350 static struct spelling *spelling; /* Next stack element (unused). */
4351 static struct spelling *spelling_base; /* Spelling stack base. */
4352 static int spelling_size; /* Size of the spelling stack. */
4353
4354 /* Macros to save and restore the spelling stack around push_... functions.
4355 Alternative to SAVE_SPELLING_STACK. */
4356
4357 #define SPELLING_DEPTH() (spelling - spelling_base)
4358 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4359
4360 /* Push an element on the spelling stack with type KIND and assign VALUE
4361 to MEMBER. */
4362
4363 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4364 { \
4365 int depth = SPELLING_DEPTH (); \
4366 \
4367 if (depth >= spelling_size) \
4368 { \
4369 spelling_size += 10; \
4370 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4371 spelling_size); \
4372 RESTORE_SPELLING_DEPTH (depth); \
4373 } \
4374 \
4375 spelling->kind = (KIND); \
4376 spelling->MEMBER = (VALUE); \
4377 spelling++; \
4378 }
4379
4380 /* Push STRING on the stack. Printed literally. */
4381
4382 static void
4383 push_string (const char *string)
4384 {
4385 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4386 }
4387
4388 /* Push a member name on the stack. Printed as '.' STRING. */
4389
4390 static void
4391 push_member_name (tree decl)
4392 {
4393 const char *const string
4394 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4395 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4396 }
4397
4398 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4399
4400 static void
4401 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4402 {
4403 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4404 }
4405
4406 /* Compute the maximum size in bytes of the printed spelling. */
4407
4408 static int
4409 spelling_length (void)
4410 {
4411 int size = 0;
4412 struct spelling *p;
4413
4414 for (p = spelling_base; p < spelling; p++)
4415 {
4416 if (p->kind == SPELLING_BOUNDS)
4417 size += 25;
4418 else
4419 size += strlen (p->u.s) + 1;
4420 }
4421
4422 return size;
4423 }
4424
4425 /* Print the spelling to BUFFER and return it. */
4426
4427 static char *
4428 print_spelling (char *buffer)
4429 {
4430 char *d = buffer;
4431 struct spelling *p;
4432
4433 for (p = spelling_base; p < spelling; p++)
4434 if (p->kind == SPELLING_BOUNDS)
4435 {
4436 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4437 d += strlen (d);
4438 }
4439 else
4440 {
4441 const char *s;
4442 if (p->kind == SPELLING_MEMBER)
4443 *d++ = '.';
4444 for (s = p->u.s; (*d = *s++); d++)
4445 ;
4446 }
4447 *d++ = '\0';
4448 return buffer;
4449 }
4450
4451 /* Issue an error message for a bad initializer component.
4452 MSGID identifies the message.
4453 The component name is taken from the spelling stack. */
4454
4455 void
4456 error_init (const char *msgid)
4457 {
4458 char *ofwhat;
4459
4460 error ("%s", _(msgid));
4461 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4462 if (*ofwhat)
4463 error ("(near initialization for %qs)", ofwhat);
4464 }
4465
4466 /* Issue a pedantic warning for a bad initializer component.
4467 MSGID identifies the message.
4468 The component name is taken from the spelling stack. */
4469
4470 void
4471 pedwarn_init (const char *msgid)
4472 {
4473 char *ofwhat;
4474
4475 pedwarn ("%s", _(msgid));
4476 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4477 if (*ofwhat)
4478 pedwarn ("(near initialization for %qs)", ofwhat);
4479 }
4480
4481 /* Issue a warning for a bad initializer component.
4482 MSGID identifies the message.
4483 The component name is taken from the spelling stack. */
4484
4485 static void
4486 warning_init (const char *msgid)
4487 {
4488 char *ofwhat;
4489
4490 warning (0, "%s", _(msgid));
4491 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4492 if (*ofwhat)
4493 warning (0, "(near initialization for %qs)", ofwhat);
4494 }
4495 \f
4496 /* If TYPE is an array type and EXPR is a parenthesized string
4497 constant, warn if pedantic that EXPR is being used to initialize an
4498 object of type TYPE. */
4499
4500 void
4501 maybe_warn_string_init (tree type, struct c_expr expr)
4502 {
4503 if (pedantic
4504 && TREE_CODE (type) == ARRAY_TYPE
4505 && TREE_CODE (expr.value) == STRING_CST
4506 && expr.original_code != STRING_CST)
4507 pedwarn_init ("array initialized from parenthesized string constant");
4508 }
4509
4510 /* Digest the parser output INIT as an initializer for type TYPE.
4511 Return a C expression of type TYPE to represent the initial value.
4512
4513 If INIT is a string constant, STRICT_STRING is true if it is
4514 unparenthesized or we should not warn here for it being parenthesized.
4515 For other types of INIT, STRICT_STRING is not used.
4516
4517 REQUIRE_CONSTANT requests an error if non-constant initializers or
4518 elements are seen. */
4519
4520 static tree
4521 digest_init (tree type, tree init, bool strict_string, int require_constant)
4522 {
4523 enum tree_code code = TREE_CODE (type);
4524 tree inside_init = init;
4525
4526 if (type == error_mark_node
4527 || !init
4528 || init == error_mark_node
4529 || TREE_TYPE (init) == error_mark_node)
4530 return error_mark_node;
4531
4532 STRIP_TYPE_NOPS (inside_init);
4533
4534 inside_init = fold (inside_init);
4535
4536 /* Initialization of an array of chars from a string constant
4537 optionally enclosed in braces. */
4538
4539 if (code == ARRAY_TYPE && inside_init
4540 && TREE_CODE (inside_init) == STRING_CST)
4541 {
4542 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4543 /* Note that an array could be both an array of character type
4544 and an array of wchar_t if wchar_t is signed char or unsigned
4545 char. */
4546 bool char_array = (typ1 == char_type_node
4547 || typ1 == signed_char_type_node
4548 || typ1 == unsigned_char_type_node);
4549 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4550 if (char_array || wchar_array)
4551 {
4552 struct c_expr expr;
4553 bool char_string;
4554 expr.value = inside_init;
4555 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4556 maybe_warn_string_init (type, expr);
4557
4558 char_string
4559 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4560 == char_type_node);
4561
4562 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4563 TYPE_MAIN_VARIANT (type)))
4564 return inside_init;
4565
4566 if (!wchar_array && !char_string)
4567 {
4568 error_init ("char-array initialized from wide string");
4569 return error_mark_node;
4570 }
4571 if (char_string && !char_array)
4572 {
4573 error_init ("wchar_t-array initialized from non-wide string");
4574 return error_mark_node;
4575 }
4576
4577 TREE_TYPE (inside_init) = type;
4578 if (TYPE_DOMAIN (type) != 0
4579 && TYPE_SIZE (type) != 0
4580 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4581 /* Subtract 1 (or sizeof (wchar_t))
4582 because it's ok to ignore the terminating null char
4583 that is counted in the length of the constant. */
4584 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4585 TREE_STRING_LENGTH (inside_init)
4586 - ((TYPE_PRECISION (typ1)
4587 != TYPE_PRECISION (char_type_node))
4588 ? (TYPE_PRECISION (wchar_type_node)
4589 / BITS_PER_UNIT)
4590 : 1)))
4591 pedwarn_init ("initializer-string for array of chars is too long");
4592
4593 return inside_init;
4594 }
4595 else if (INTEGRAL_TYPE_P (typ1))
4596 {
4597 error_init ("array of inappropriate type initialized "
4598 "from string constant");
4599 return error_mark_node;
4600 }
4601 }
4602
4603 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4604 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4605 below and handle as a constructor. */
4606 if (code == VECTOR_TYPE
4607 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4608 && vector_types_convertible_p (TREE_TYPE (inside_init), type, true)
4609 && TREE_CONSTANT (inside_init))
4610 {
4611 if (TREE_CODE (inside_init) == VECTOR_CST
4612 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4613 TYPE_MAIN_VARIANT (type)))
4614 return inside_init;
4615
4616 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4617 {
4618 unsigned HOST_WIDE_INT ix;
4619 tree value;
4620 bool constant_p = true;
4621
4622 /* Iterate through elements and check if all constructor
4623 elements are *_CSTs. */
4624 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4625 if (!CONSTANT_CLASS_P (value))
4626 {
4627 constant_p = false;
4628 break;
4629 }
4630
4631 if (constant_p)
4632 return build_vector_from_ctor (type,
4633 CONSTRUCTOR_ELTS (inside_init));
4634 }
4635 }
4636
4637 /* Any type can be initialized
4638 from an expression of the same type, optionally with braces. */
4639
4640 if (inside_init && TREE_TYPE (inside_init) != 0
4641 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4642 TYPE_MAIN_VARIANT (type))
4643 || (code == ARRAY_TYPE
4644 && comptypes (TREE_TYPE (inside_init), type))
4645 || (code == VECTOR_TYPE
4646 && comptypes (TREE_TYPE (inside_init), type))
4647 || (code == POINTER_TYPE
4648 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4649 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4650 TREE_TYPE (type)))))
4651 {
4652 if (code == POINTER_TYPE)
4653 {
4654 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4655 {
4656 if (TREE_CODE (inside_init) == STRING_CST
4657 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4658 inside_init = array_to_pointer_conversion (inside_init);
4659 else
4660 {
4661 error_init ("invalid use of non-lvalue array");
4662 return error_mark_node;
4663 }
4664 }
4665 }
4666
4667 if (code == VECTOR_TYPE)
4668 /* Although the types are compatible, we may require a
4669 conversion. */
4670 inside_init = convert (type, inside_init);
4671
4672 if (require_constant
4673 && (code == VECTOR_TYPE || !flag_isoc99)
4674 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4675 {
4676 /* As an extension, allow initializing objects with static storage
4677 duration with compound literals (which are then treated just as
4678 the brace enclosed list they contain). Also allow this for
4679 vectors, as we can only assign them with compound literals. */
4680 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4681 inside_init = DECL_INITIAL (decl);
4682 }
4683
4684 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4685 && TREE_CODE (inside_init) != CONSTRUCTOR)
4686 {
4687 error_init ("array initialized from non-constant array expression");
4688 return error_mark_node;
4689 }
4690
4691 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4692 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4693
4694 /* Compound expressions can only occur here if -pedantic or
4695 -pedantic-errors is specified. In the later case, we always want
4696 an error. In the former case, we simply want a warning. */
4697 if (require_constant && pedantic
4698 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4699 {
4700 inside_init
4701 = valid_compound_expr_initializer (inside_init,
4702 TREE_TYPE (inside_init));
4703 if (inside_init == error_mark_node)
4704 error_init ("initializer element is not constant");
4705 else
4706 pedwarn_init ("initializer element is not constant");
4707 if (flag_pedantic_errors)
4708 inside_init = error_mark_node;
4709 }
4710 else if (require_constant
4711 && !initializer_constant_valid_p (inside_init,
4712 TREE_TYPE (inside_init)))
4713 {
4714 error_init ("initializer element is not constant");
4715 inside_init = error_mark_node;
4716 }
4717
4718 /* Added to enable additional -Wmissing-format-attribute warnings. */
4719 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4720 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4721 NULL_TREE, 0);
4722 return inside_init;
4723 }
4724
4725 /* Handle scalar types, including conversions. */
4726
4727 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4728 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE
4729 || code == VECTOR_TYPE)
4730 {
4731 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4732 && (TREE_CODE (init) == STRING_CST
4733 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4734 init = array_to_pointer_conversion (init);
4735 inside_init
4736 = convert_for_assignment (type, init, ic_init,
4737 NULL_TREE, NULL_TREE, 0);
4738
4739 /* Check to see if we have already given an error message. */
4740 if (inside_init == error_mark_node)
4741 ;
4742 else if (require_constant && !TREE_CONSTANT (inside_init))
4743 {
4744 error_init ("initializer element is not constant");
4745 inside_init = error_mark_node;
4746 }
4747 else if (require_constant
4748 && !initializer_constant_valid_p (inside_init,
4749 TREE_TYPE (inside_init)))
4750 {
4751 error_init ("initializer element is not computable at load time");
4752 inside_init = error_mark_node;
4753 }
4754
4755 return inside_init;
4756 }
4757
4758 /* Come here only for records and arrays. */
4759
4760 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4761 {
4762 error_init ("variable-sized object may not be initialized");
4763 return error_mark_node;
4764 }
4765
4766 error_init ("invalid initializer");
4767 return error_mark_node;
4768 }
4769 \f
4770 /* Handle initializers that use braces. */
4771
4772 /* Type of object we are accumulating a constructor for.
4773 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4774 static tree constructor_type;
4775
4776 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4777 left to fill. */
4778 static tree constructor_fields;
4779
4780 /* For an ARRAY_TYPE, this is the specified index
4781 at which to store the next element we get. */
4782 static tree constructor_index;
4783
4784 /* For an ARRAY_TYPE, this is the maximum index. */
4785 static tree constructor_max_index;
4786
4787 /* For a RECORD_TYPE, this is the first field not yet written out. */
4788 static tree constructor_unfilled_fields;
4789
4790 /* For an ARRAY_TYPE, this is the index of the first element
4791 not yet written out. */
4792 static tree constructor_unfilled_index;
4793
4794 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4795 This is so we can generate gaps between fields, when appropriate. */
4796 static tree constructor_bit_index;
4797
4798 /* If we are saving up the elements rather than allocating them,
4799 this is the list of elements so far (in reverse order,
4800 most recent first). */
4801 static VEC(constructor_elt,gc) *constructor_elements;
4802
4803 /* 1 if constructor should be incrementally stored into a constructor chain,
4804 0 if all the elements should be kept in AVL tree. */
4805 static int constructor_incremental;
4806
4807 /* 1 if so far this constructor's elements are all compile-time constants. */
4808 static int constructor_constant;
4809
4810 /* 1 if so far this constructor's elements are all valid address constants. */
4811 static int constructor_simple;
4812
4813 /* 1 if this constructor is erroneous so far. */
4814 static int constructor_erroneous;
4815
4816 /* Structure for managing pending initializer elements, organized as an
4817 AVL tree. */
4818
4819 struct init_node
4820 {
4821 struct init_node *left, *right;
4822 struct init_node *parent;
4823 int balance;
4824 tree purpose;
4825 tree value;
4826 };
4827
4828 /* Tree of pending elements at this constructor level.
4829 These are elements encountered out of order
4830 which belong at places we haven't reached yet in actually
4831 writing the output.
4832 Will never hold tree nodes across GC runs. */
4833 static struct init_node *constructor_pending_elts;
4834
4835 /* The SPELLING_DEPTH of this constructor. */
4836 static int constructor_depth;
4837
4838 /* DECL node for which an initializer is being read.
4839 0 means we are reading a constructor expression
4840 such as (struct foo) {...}. */
4841 static tree constructor_decl;
4842
4843 /* Nonzero if this is an initializer for a top-level decl. */
4844 static int constructor_top_level;
4845
4846 /* Nonzero if there were any member designators in this initializer. */
4847 static int constructor_designated;
4848
4849 /* Nesting depth of designator list. */
4850 static int designator_depth;
4851
4852 /* Nonzero if there were diagnosed errors in this designator list. */
4853 static int designator_erroneous;
4854
4855 \f
4856 /* This stack has a level for each implicit or explicit level of
4857 structuring in the initializer, including the outermost one. It
4858 saves the values of most of the variables above. */
4859
4860 struct constructor_range_stack;
4861
4862 struct constructor_stack
4863 {
4864 struct constructor_stack *next;
4865 tree type;
4866 tree fields;
4867 tree index;
4868 tree max_index;
4869 tree unfilled_index;
4870 tree unfilled_fields;
4871 tree bit_index;
4872 VEC(constructor_elt,gc) *elements;
4873 struct init_node *pending_elts;
4874 int offset;
4875 int depth;
4876 /* If value nonzero, this value should replace the entire
4877 constructor at this level. */
4878 struct c_expr replacement_value;
4879 struct constructor_range_stack *range_stack;
4880 char constant;
4881 char simple;
4882 char implicit;
4883 char erroneous;
4884 char outer;
4885 char incremental;
4886 char designated;
4887 };
4888
4889 static struct constructor_stack *constructor_stack;
4890
4891 /* This stack represents designators from some range designator up to
4892 the last designator in the list. */
4893
4894 struct constructor_range_stack
4895 {
4896 struct constructor_range_stack *next, *prev;
4897 struct constructor_stack *stack;
4898 tree range_start;
4899 tree index;
4900 tree range_end;
4901 tree fields;
4902 };
4903
4904 static struct constructor_range_stack *constructor_range_stack;
4905
4906 /* This stack records separate initializers that are nested.
4907 Nested initializers can't happen in ANSI C, but GNU C allows them
4908 in cases like { ... (struct foo) { ... } ... }. */
4909
4910 struct initializer_stack
4911 {
4912 struct initializer_stack *next;
4913 tree decl;
4914 struct constructor_stack *constructor_stack;
4915 struct constructor_range_stack *constructor_range_stack;
4916 VEC(constructor_elt,gc) *elements;
4917 struct spelling *spelling;
4918 struct spelling *spelling_base;
4919 int spelling_size;
4920 char top_level;
4921 char require_constant_value;
4922 char require_constant_elements;
4923 };
4924
4925 static struct initializer_stack *initializer_stack;
4926 \f
4927 /* Prepare to parse and output the initializer for variable DECL. */
4928
4929 void
4930 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
4931 {
4932 const char *locus;
4933 struct initializer_stack *p = XNEW (struct initializer_stack);
4934
4935 p->decl = constructor_decl;
4936 p->require_constant_value = require_constant_value;
4937 p->require_constant_elements = require_constant_elements;
4938 p->constructor_stack = constructor_stack;
4939 p->constructor_range_stack = constructor_range_stack;
4940 p->elements = constructor_elements;
4941 p->spelling = spelling;
4942 p->spelling_base = spelling_base;
4943 p->spelling_size = spelling_size;
4944 p->top_level = constructor_top_level;
4945 p->next = initializer_stack;
4946 initializer_stack = p;
4947
4948 constructor_decl = decl;
4949 constructor_designated = 0;
4950 constructor_top_level = top_level;
4951
4952 if (decl != 0 && decl != error_mark_node)
4953 {
4954 require_constant_value = TREE_STATIC (decl);
4955 require_constant_elements
4956 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
4957 /* For a scalar, you can always use any value to initialize,
4958 even within braces. */
4959 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
4960 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
4961 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
4962 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
4963 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
4964 }
4965 else
4966 {
4967 require_constant_value = 0;
4968 require_constant_elements = 0;
4969 locus = "(anonymous)";
4970 }
4971
4972 constructor_stack = 0;
4973 constructor_range_stack = 0;
4974
4975 missing_braces_mentioned = 0;
4976
4977 spelling_base = 0;
4978 spelling_size = 0;
4979 RESTORE_SPELLING_DEPTH (0);
4980
4981 if (locus)
4982 push_string (locus);
4983 }
4984
4985 void
4986 finish_init (void)
4987 {
4988 struct initializer_stack *p = initializer_stack;
4989
4990 /* Free the whole constructor stack of this initializer. */
4991 while (constructor_stack)
4992 {
4993 struct constructor_stack *q = constructor_stack;
4994 constructor_stack = q->next;
4995 free (q);
4996 }
4997
4998 gcc_assert (!constructor_range_stack);
4999
5000 /* Pop back to the data of the outer initializer (if any). */
5001 free (spelling_base);
5002
5003 constructor_decl = p->decl;
5004 require_constant_value = p->require_constant_value;
5005 require_constant_elements = p->require_constant_elements;
5006 constructor_stack = p->constructor_stack;
5007 constructor_range_stack = p->constructor_range_stack;
5008 constructor_elements = p->elements;
5009 spelling = p->spelling;
5010 spelling_base = p->spelling_base;
5011 spelling_size = p->spelling_size;
5012 constructor_top_level = p->top_level;
5013 initializer_stack = p->next;
5014 free (p);
5015 }
5016 \f
5017 /* Call here when we see the initializer is surrounded by braces.
5018 This is instead of a call to push_init_level;
5019 it is matched by a call to pop_init_level.
5020
5021 TYPE is the type to initialize, for a constructor expression.
5022 For an initializer for a decl, TYPE is zero. */
5023
5024 void
5025 really_start_incremental_init (tree type)
5026 {
5027 struct constructor_stack *p = XNEW (struct constructor_stack);
5028
5029 if (type == 0)
5030 type = TREE_TYPE (constructor_decl);
5031
5032 if (targetm.vector_opaque_p (type))
5033 error ("opaque vector types cannot be initialized");
5034
5035 p->type = constructor_type;
5036 p->fields = constructor_fields;
5037 p->index = constructor_index;
5038 p->max_index = constructor_max_index;
5039 p->unfilled_index = constructor_unfilled_index;
5040 p->unfilled_fields = constructor_unfilled_fields;
5041 p->bit_index = constructor_bit_index;
5042 p->elements = constructor_elements;
5043 p->constant = constructor_constant;
5044 p->simple = constructor_simple;
5045 p->erroneous = constructor_erroneous;
5046 p->pending_elts = constructor_pending_elts;
5047 p->depth = constructor_depth;
5048 p->replacement_value.value = 0;
5049 p->replacement_value.original_code = ERROR_MARK;
5050 p->implicit = 0;
5051 p->range_stack = 0;
5052 p->outer = 0;
5053 p->incremental = constructor_incremental;
5054 p->designated = constructor_designated;
5055 p->next = 0;
5056 constructor_stack = p;
5057
5058 constructor_constant = 1;
5059 constructor_simple = 1;
5060 constructor_depth = SPELLING_DEPTH ();
5061 constructor_elements = 0;
5062 constructor_pending_elts = 0;
5063 constructor_type = type;
5064 constructor_incremental = 1;
5065 constructor_designated = 0;
5066 designator_depth = 0;
5067 designator_erroneous = 0;
5068
5069 if (TREE_CODE (constructor_type) == RECORD_TYPE
5070 || TREE_CODE (constructor_type) == UNION_TYPE)
5071 {
5072 constructor_fields = TYPE_FIELDS (constructor_type);
5073 /* Skip any nameless bit fields at the beginning. */
5074 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5075 && DECL_NAME (constructor_fields) == 0)
5076 constructor_fields = TREE_CHAIN (constructor_fields);
5077
5078 constructor_unfilled_fields = constructor_fields;
5079 constructor_bit_index = bitsize_zero_node;
5080 }
5081 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5082 {
5083 if (TYPE_DOMAIN (constructor_type))
5084 {
5085 constructor_max_index
5086 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5087
5088 /* Detect non-empty initializations of zero-length arrays. */
5089 if (constructor_max_index == NULL_TREE
5090 && TYPE_SIZE (constructor_type))
5091 constructor_max_index = build_int_cst (NULL_TREE, -1);
5092
5093 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5094 to initialize VLAs will cause a proper error; avoid tree
5095 checking errors as well by setting a safe value. */
5096 if (constructor_max_index
5097 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5098 constructor_max_index = build_int_cst (NULL_TREE, -1);
5099
5100 constructor_index
5101 = convert (bitsizetype,
5102 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5103 }
5104 else
5105 {
5106 constructor_index = bitsize_zero_node;
5107 constructor_max_index = NULL_TREE;
5108 }
5109
5110 constructor_unfilled_index = constructor_index;
5111 }
5112 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5113 {
5114 /* Vectors are like simple fixed-size arrays. */
5115 constructor_max_index =
5116 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5117 constructor_index = bitsize_zero_node;
5118 constructor_unfilled_index = constructor_index;
5119 }
5120 else
5121 {
5122 /* Handle the case of int x = {5}; */
5123 constructor_fields = constructor_type;
5124 constructor_unfilled_fields = constructor_type;
5125 }
5126 }
5127 \f
5128 /* Push down into a subobject, for initialization.
5129 If this is for an explicit set of braces, IMPLICIT is 0.
5130 If it is because the next element belongs at a lower level,
5131 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5132
5133 void
5134 push_init_level (int implicit)
5135 {
5136 struct constructor_stack *p;
5137 tree value = NULL_TREE;
5138
5139 /* If we've exhausted any levels that didn't have braces,
5140 pop them now. If implicit == 1, this will have been done in
5141 process_init_element; do not repeat it here because in the case
5142 of excess initializers for an empty aggregate this leads to an
5143 infinite cycle of popping a level and immediately recreating
5144 it. */
5145 if (implicit != 1)
5146 {
5147 while (constructor_stack->implicit)
5148 {
5149 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5150 || TREE_CODE (constructor_type) == UNION_TYPE)
5151 && constructor_fields == 0)
5152 process_init_element (pop_init_level (1));
5153 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5154 && constructor_max_index
5155 && tree_int_cst_lt (constructor_max_index,
5156 constructor_index))
5157 process_init_element (pop_init_level (1));
5158 else
5159 break;
5160 }
5161 }
5162
5163 /* Unless this is an explicit brace, we need to preserve previous
5164 content if any. */
5165 if (implicit)
5166 {
5167 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5168 || TREE_CODE (constructor_type) == UNION_TYPE)
5169 && constructor_fields)
5170 value = find_init_member (constructor_fields);
5171 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5172 value = find_init_member (constructor_index);
5173 }
5174
5175 p = XNEW (struct constructor_stack);
5176 p->type = constructor_type;
5177 p->fields = constructor_fields;
5178 p->index = constructor_index;
5179 p->max_index = constructor_max_index;
5180 p->unfilled_index = constructor_unfilled_index;
5181 p->unfilled_fields = constructor_unfilled_fields;
5182 p->bit_index = constructor_bit_index;
5183 p->elements = constructor_elements;
5184 p->constant = constructor_constant;
5185 p->simple = constructor_simple;
5186 p->erroneous = constructor_erroneous;
5187 p->pending_elts = constructor_pending_elts;
5188 p->depth = constructor_depth;
5189 p->replacement_value.value = 0;
5190 p->replacement_value.original_code = ERROR_MARK;
5191 p->implicit = implicit;
5192 p->outer = 0;
5193 p->incremental = constructor_incremental;
5194 p->designated = constructor_designated;
5195 p->next = constructor_stack;
5196 p->range_stack = 0;
5197 constructor_stack = p;
5198
5199 constructor_constant = 1;
5200 constructor_simple = 1;
5201 constructor_depth = SPELLING_DEPTH ();
5202 constructor_elements = 0;
5203 constructor_incremental = 1;
5204 constructor_designated = 0;
5205 constructor_pending_elts = 0;
5206 if (!implicit)
5207 {
5208 p->range_stack = constructor_range_stack;
5209 constructor_range_stack = 0;
5210 designator_depth = 0;
5211 designator_erroneous = 0;
5212 }
5213
5214 /* Don't die if an entire brace-pair level is superfluous
5215 in the containing level. */
5216 if (constructor_type == 0)
5217 ;
5218 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5219 || TREE_CODE (constructor_type) == UNION_TYPE)
5220 {
5221 /* Don't die if there are extra init elts at the end. */
5222 if (constructor_fields == 0)
5223 constructor_type = 0;
5224 else
5225 {
5226 constructor_type = TREE_TYPE (constructor_fields);
5227 push_member_name (constructor_fields);
5228 constructor_depth++;
5229 }
5230 }
5231 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5232 {
5233 constructor_type = TREE_TYPE (constructor_type);
5234 push_array_bounds (tree_low_cst (constructor_index, 1));
5235 constructor_depth++;
5236 }
5237
5238 if (constructor_type == 0)
5239 {
5240 error_init ("extra brace group at end of initializer");
5241 constructor_fields = 0;
5242 constructor_unfilled_fields = 0;
5243 return;
5244 }
5245
5246 if (value && TREE_CODE (value) == CONSTRUCTOR)
5247 {
5248 constructor_constant = TREE_CONSTANT (value);
5249 constructor_simple = TREE_STATIC (value);
5250 constructor_elements = CONSTRUCTOR_ELTS (value);
5251 if (!VEC_empty (constructor_elt, constructor_elements)
5252 && (TREE_CODE (constructor_type) == RECORD_TYPE
5253 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5254 set_nonincremental_init ();
5255 }
5256
5257 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5258 {
5259 missing_braces_mentioned = 1;
5260 warning_init ("missing braces around initializer");
5261 }
5262
5263 if (TREE_CODE (constructor_type) == RECORD_TYPE
5264 || TREE_CODE (constructor_type) == UNION_TYPE)
5265 {
5266 constructor_fields = TYPE_FIELDS (constructor_type);
5267 /* Skip any nameless bit fields at the beginning. */
5268 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5269 && DECL_NAME (constructor_fields) == 0)
5270 constructor_fields = TREE_CHAIN (constructor_fields);
5271
5272 constructor_unfilled_fields = constructor_fields;
5273 constructor_bit_index = bitsize_zero_node;
5274 }
5275 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5276 {
5277 /* Vectors are like simple fixed-size arrays. */
5278 constructor_max_index =
5279 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5280 constructor_index = convert (bitsizetype, integer_zero_node);
5281 constructor_unfilled_index = constructor_index;
5282 }
5283 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5284 {
5285 if (TYPE_DOMAIN (constructor_type))
5286 {
5287 constructor_max_index
5288 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5289
5290 /* Detect non-empty initializations of zero-length arrays. */
5291 if (constructor_max_index == NULL_TREE
5292 && TYPE_SIZE (constructor_type))
5293 constructor_max_index = build_int_cst (NULL_TREE, -1);
5294
5295 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5296 to initialize VLAs will cause a proper error; avoid tree
5297 checking errors as well by setting a safe value. */
5298 if (constructor_max_index
5299 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5300 constructor_max_index = build_int_cst (NULL_TREE, -1);
5301
5302 constructor_index
5303 = convert (bitsizetype,
5304 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5305 }
5306 else
5307 constructor_index = bitsize_zero_node;
5308
5309 constructor_unfilled_index = constructor_index;
5310 if (value && TREE_CODE (value) == STRING_CST)
5311 {
5312 /* We need to split the char/wchar array into individual
5313 characters, so that we don't have to special case it
5314 everywhere. */
5315 set_nonincremental_init_from_string (value);
5316 }
5317 }
5318 else
5319 {
5320 if (constructor_type != error_mark_node)
5321 warning_init ("braces around scalar initializer");
5322 constructor_fields = constructor_type;
5323 constructor_unfilled_fields = constructor_type;
5324 }
5325 }
5326
5327 /* At the end of an implicit or explicit brace level,
5328 finish up that level of constructor. If a single expression
5329 with redundant braces initialized that level, return the
5330 c_expr structure for that expression. Otherwise, the original_code
5331 element is set to ERROR_MARK.
5332 If we were outputting the elements as they are read, return 0 as the value
5333 from inner levels (process_init_element ignores that),
5334 but return error_mark_node as the value from the outermost level
5335 (that's what we want to put in DECL_INITIAL).
5336 Otherwise, return a CONSTRUCTOR expression as the value. */
5337
5338 struct c_expr
5339 pop_init_level (int implicit)
5340 {
5341 struct constructor_stack *p;
5342 struct c_expr ret;
5343 ret.value = 0;
5344 ret.original_code = ERROR_MARK;
5345
5346 if (implicit == 0)
5347 {
5348 /* When we come to an explicit close brace,
5349 pop any inner levels that didn't have explicit braces. */
5350 while (constructor_stack->implicit)
5351 process_init_element (pop_init_level (1));
5352
5353 gcc_assert (!constructor_range_stack);
5354 }
5355
5356 /* Now output all pending elements. */
5357 constructor_incremental = 1;
5358 output_pending_init_elements (1);
5359
5360 p = constructor_stack;
5361
5362 /* Error for initializing a flexible array member, or a zero-length
5363 array member in an inappropriate context. */
5364 if (constructor_type && constructor_fields
5365 && TREE_CODE (constructor_type) == ARRAY_TYPE
5366 && TYPE_DOMAIN (constructor_type)
5367 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5368 {
5369 /* Silently discard empty initializations. The parser will
5370 already have pedwarned for empty brackets. */
5371 if (integer_zerop (constructor_unfilled_index))
5372 constructor_type = NULL_TREE;
5373 else
5374 {
5375 gcc_assert (!TYPE_SIZE (constructor_type));
5376
5377 if (constructor_depth > 2)
5378 error_init ("initialization of flexible array member in a nested context");
5379 else if (pedantic)
5380 pedwarn_init ("initialization of a flexible array member");
5381
5382 /* We have already issued an error message for the existence
5383 of a flexible array member not at the end of the structure.
5384 Discard the initializer so that we do not die later. */
5385 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5386 constructor_type = NULL_TREE;
5387 }
5388 }
5389
5390 /* Warn when some struct elements are implicitly initialized to zero. */
5391 if (warn_missing_field_initializers
5392 && constructor_type
5393 && TREE_CODE (constructor_type) == RECORD_TYPE
5394 && constructor_unfilled_fields)
5395 {
5396 /* Do not warn for flexible array members or zero-length arrays. */
5397 while (constructor_unfilled_fields
5398 && (!DECL_SIZE (constructor_unfilled_fields)
5399 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5400 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5401
5402 /* Do not warn if this level of the initializer uses member
5403 designators; it is likely to be deliberate. */
5404 if (constructor_unfilled_fields && !constructor_designated)
5405 {
5406 push_member_name (constructor_unfilled_fields);
5407 warning_init ("missing initializer");
5408 RESTORE_SPELLING_DEPTH (constructor_depth);
5409 }
5410 }
5411
5412 /* Pad out the end of the structure. */
5413 if (p->replacement_value.value)
5414 /* If this closes a superfluous brace pair,
5415 just pass out the element between them. */
5416 ret = p->replacement_value;
5417 else if (constructor_type == 0)
5418 ;
5419 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5420 && TREE_CODE (constructor_type) != UNION_TYPE
5421 && TREE_CODE (constructor_type) != ARRAY_TYPE
5422 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5423 {
5424 /* A nonincremental scalar initializer--just return
5425 the element, after verifying there is just one. */
5426 if (VEC_empty (constructor_elt,constructor_elements))
5427 {
5428 if (!constructor_erroneous)
5429 error_init ("empty scalar initializer");
5430 ret.value = error_mark_node;
5431 }
5432 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5433 {
5434 error_init ("extra elements in scalar initializer");
5435 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5436 }
5437 else
5438 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5439 }
5440 else
5441 {
5442 if (constructor_erroneous)
5443 ret.value = error_mark_node;
5444 else
5445 {
5446 ret.value = build_constructor (constructor_type,
5447 constructor_elements);
5448 if (constructor_constant)
5449 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1;
5450 if (constructor_constant && constructor_simple)
5451 TREE_STATIC (ret.value) = 1;
5452 }
5453 }
5454
5455 constructor_type = p->type;
5456 constructor_fields = p->fields;
5457 constructor_index = p->index;
5458 constructor_max_index = p->max_index;
5459 constructor_unfilled_index = p->unfilled_index;
5460 constructor_unfilled_fields = p->unfilled_fields;
5461 constructor_bit_index = p->bit_index;
5462 constructor_elements = p->elements;
5463 constructor_constant = p->constant;
5464 constructor_simple = p->simple;
5465 constructor_erroneous = p->erroneous;
5466 constructor_incremental = p->incremental;
5467 constructor_designated = p->designated;
5468 constructor_pending_elts = p->pending_elts;
5469 constructor_depth = p->depth;
5470 if (!p->implicit)
5471 constructor_range_stack = p->range_stack;
5472 RESTORE_SPELLING_DEPTH (constructor_depth);
5473
5474 constructor_stack = p->next;
5475 free (p);
5476
5477 if (ret.value == 0 && constructor_stack == 0)
5478 ret.value = error_mark_node;
5479 return ret;
5480 }
5481
5482 /* Common handling for both array range and field name designators.
5483 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5484
5485 static int
5486 set_designator (int array)
5487 {
5488 tree subtype;
5489 enum tree_code subcode;
5490
5491 /* Don't die if an entire brace-pair level is superfluous
5492 in the containing level. */
5493 if (constructor_type == 0)
5494 return 1;
5495
5496 /* If there were errors in this designator list already, bail out
5497 silently. */
5498 if (designator_erroneous)
5499 return 1;
5500
5501 if (!designator_depth)
5502 {
5503 gcc_assert (!constructor_range_stack);
5504
5505 /* Designator list starts at the level of closest explicit
5506 braces. */
5507 while (constructor_stack->implicit)
5508 process_init_element (pop_init_level (1));
5509 constructor_designated = 1;
5510 return 0;
5511 }
5512
5513 switch (TREE_CODE (constructor_type))
5514 {
5515 case RECORD_TYPE:
5516 case UNION_TYPE:
5517 subtype = TREE_TYPE (constructor_fields);
5518 if (subtype != error_mark_node)
5519 subtype = TYPE_MAIN_VARIANT (subtype);
5520 break;
5521 case ARRAY_TYPE:
5522 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5523 break;
5524 default:
5525 gcc_unreachable ();
5526 }
5527
5528 subcode = TREE_CODE (subtype);
5529 if (array && subcode != ARRAY_TYPE)
5530 {
5531 error_init ("array index in non-array initializer");
5532 return 1;
5533 }
5534 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5535 {
5536 error_init ("field name not in record or union initializer");
5537 return 1;
5538 }
5539
5540 constructor_designated = 1;
5541 push_init_level (2);
5542 return 0;
5543 }
5544
5545 /* If there are range designators in designator list, push a new designator
5546 to constructor_range_stack. RANGE_END is end of such stack range or
5547 NULL_TREE if there is no range designator at this level. */
5548
5549 static void
5550 push_range_stack (tree range_end)
5551 {
5552 struct constructor_range_stack *p;
5553
5554 p = GGC_NEW (struct constructor_range_stack);
5555 p->prev = constructor_range_stack;
5556 p->next = 0;
5557 p->fields = constructor_fields;
5558 p->range_start = constructor_index;
5559 p->index = constructor_index;
5560 p->stack = constructor_stack;
5561 p->range_end = range_end;
5562 if (constructor_range_stack)
5563 constructor_range_stack->next = p;
5564 constructor_range_stack = p;
5565 }
5566
5567 /* Within an array initializer, specify the next index to be initialized.
5568 FIRST is that index. If LAST is nonzero, then initialize a range
5569 of indices, running from FIRST through LAST. */
5570
5571 void
5572 set_init_index (tree first, tree last)
5573 {
5574 if (set_designator (1))
5575 return;
5576
5577 designator_erroneous = 1;
5578
5579 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5580 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5581 {
5582 error_init ("array index in initializer not of integer type");
5583 return;
5584 }
5585
5586 if (TREE_CODE (first) != INTEGER_CST)
5587 error_init ("nonconstant array index in initializer");
5588 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5589 error_init ("nonconstant array index in initializer");
5590 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5591 error_init ("array index in non-array initializer");
5592 else if (tree_int_cst_sgn (first) == -1)
5593 error_init ("array index in initializer exceeds array bounds");
5594 else if (constructor_max_index
5595 && tree_int_cst_lt (constructor_max_index, first))
5596 error_init ("array index in initializer exceeds array bounds");
5597 else
5598 {
5599 constructor_index = convert (bitsizetype, first);
5600
5601 if (last)
5602 {
5603 if (tree_int_cst_equal (first, last))
5604 last = 0;
5605 else if (tree_int_cst_lt (last, first))
5606 {
5607 error_init ("empty index range in initializer");
5608 last = 0;
5609 }
5610 else
5611 {
5612 last = convert (bitsizetype, last);
5613 if (constructor_max_index != 0
5614 && tree_int_cst_lt (constructor_max_index, last))
5615 {
5616 error_init ("array index range in initializer exceeds array bounds");
5617 last = 0;
5618 }
5619 }
5620 }
5621
5622 designator_depth++;
5623 designator_erroneous = 0;
5624 if (constructor_range_stack || last)
5625 push_range_stack (last);
5626 }
5627 }
5628
5629 /* Within a struct initializer, specify the next field to be initialized. */
5630
5631 void
5632 set_init_label (tree fieldname)
5633 {
5634 tree tail;
5635
5636 if (set_designator (0))
5637 return;
5638
5639 designator_erroneous = 1;
5640
5641 if (TREE_CODE (constructor_type) != RECORD_TYPE
5642 && TREE_CODE (constructor_type) != UNION_TYPE)
5643 {
5644 error_init ("field name not in record or union initializer");
5645 return;
5646 }
5647
5648 for (tail = TYPE_FIELDS (constructor_type); tail;
5649 tail = TREE_CHAIN (tail))
5650 {
5651 if (DECL_NAME (tail) == fieldname)
5652 break;
5653 }
5654
5655 if (tail == 0)
5656 error ("unknown field %qE specified in initializer", fieldname);
5657 else
5658 {
5659 constructor_fields = tail;
5660 designator_depth++;
5661 designator_erroneous = 0;
5662 if (constructor_range_stack)
5663 push_range_stack (NULL_TREE);
5664 }
5665 }
5666 \f
5667 /* Add a new initializer to the tree of pending initializers. PURPOSE
5668 identifies the initializer, either array index or field in a structure.
5669 VALUE is the value of that index or field. */
5670
5671 static void
5672 add_pending_init (tree purpose, tree value)
5673 {
5674 struct init_node *p, **q, *r;
5675
5676 q = &constructor_pending_elts;
5677 p = 0;
5678
5679 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5680 {
5681 while (*q != 0)
5682 {
5683 p = *q;
5684 if (tree_int_cst_lt (purpose, p->purpose))
5685 q = &p->left;
5686 else if (tree_int_cst_lt (p->purpose, purpose))
5687 q = &p->right;
5688 else
5689 {
5690 if (TREE_SIDE_EFFECTS (p->value))
5691 warning_init ("initialized field with side-effects overwritten");
5692 else if (warn_override_init)
5693 warning_init ("initialized field overwritten");
5694 p->value = value;
5695 return;
5696 }
5697 }
5698 }
5699 else
5700 {
5701 tree bitpos;
5702
5703 bitpos = bit_position (purpose);
5704 while (*q != NULL)
5705 {
5706 p = *q;
5707 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5708 q = &p->left;
5709 else if (p->purpose != purpose)
5710 q = &p->right;
5711 else
5712 {
5713 if (TREE_SIDE_EFFECTS (p->value))
5714 warning_init ("initialized field with side-effects overwritten");
5715 else if (warn_override_init)
5716 warning_init ("initialized field overwritten");
5717 p->value = value;
5718 return;
5719 }
5720 }
5721 }
5722
5723 r = GGC_NEW (struct init_node);
5724 r->purpose = purpose;
5725 r->value = value;
5726
5727 *q = r;
5728 r->parent = p;
5729 r->left = 0;
5730 r->right = 0;
5731 r->balance = 0;
5732
5733 while (p)
5734 {
5735 struct init_node *s;
5736
5737 if (r == p->left)
5738 {
5739 if (p->balance == 0)
5740 p->balance = -1;
5741 else if (p->balance < 0)
5742 {
5743 if (r->balance < 0)
5744 {
5745 /* L rotation. */
5746 p->left = r->right;
5747 if (p->left)
5748 p->left->parent = p;
5749 r->right = p;
5750
5751 p->balance = 0;
5752 r->balance = 0;
5753
5754 s = p->parent;
5755 p->parent = r;
5756 r->parent = s;
5757 if (s)
5758 {
5759 if (s->left == p)
5760 s->left = r;
5761 else
5762 s->right = r;
5763 }
5764 else
5765 constructor_pending_elts = r;
5766 }
5767 else
5768 {
5769 /* LR rotation. */
5770 struct init_node *t = r->right;
5771
5772 r->right = t->left;
5773 if (r->right)
5774 r->right->parent = r;
5775 t->left = r;
5776
5777 p->left = t->right;
5778 if (p->left)
5779 p->left->parent = p;
5780 t->right = p;
5781
5782 p->balance = t->balance < 0;
5783 r->balance = -(t->balance > 0);
5784 t->balance = 0;
5785
5786 s = p->parent;
5787 p->parent = t;
5788 r->parent = t;
5789 t->parent = s;
5790 if (s)
5791 {
5792 if (s->left == p)
5793 s->left = t;
5794 else
5795 s->right = t;
5796 }
5797 else
5798 constructor_pending_elts = t;
5799 }
5800 break;
5801 }
5802 else
5803 {
5804 /* p->balance == +1; growth of left side balances the node. */
5805 p->balance = 0;
5806 break;
5807 }
5808 }
5809 else /* r == p->right */
5810 {
5811 if (p->balance == 0)
5812 /* Growth propagation from right side. */
5813 p->balance++;
5814 else if (p->balance > 0)
5815 {
5816 if (r->balance > 0)
5817 {
5818 /* R rotation. */
5819 p->right = r->left;
5820 if (p->right)
5821 p->right->parent = p;
5822 r->left = p;
5823
5824 p->balance = 0;
5825 r->balance = 0;
5826
5827 s = p->parent;
5828 p->parent = r;
5829 r->parent = s;
5830 if (s)
5831 {
5832 if (s->left == p)
5833 s->left = r;
5834 else
5835 s->right = r;
5836 }
5837 else
5838 constructor_pending_elts = r;
5839 }
5840 else /* r->balance == -1 */
5841 {
5842 /* RL rotation */
5843 struct init_node *t = r->left;
5844
5845 r->left = t->right;
5846 if (r->left)
5847 r->left->parent = r;
5848 t->right = r;
5849
5850 p->right = t->left;
5851 if (p->right)
5852 p->right->parent = p;
5853 t->left = p;
5854
5855 r->balance = (t->balance < 0);
5856 p->balance = -(t->balance > 0);
5857 t->balance = 0;
5858
5859 s = p->parent;
5860 p->parent = t;
5861 r->parent = t;
5862 t->parent = s;
5863 if (s)
5864 {
5865 if (s->left == p)
5866 s->left = t;
5867 else
5868 s->right = t;
5869 }
5870 else
5871 constructor_pending_elts = t;
5872 }
5873 break;
5874 }
5875 else
5876 {
5877 /* p->balance == -1; growth of right side balances the node. */
5878 p->balance = 0;
5879 break;
5880 }
5881 }
5882
5883 r = p;
5884 p = p->parent;
5885 }
5886 }
5887
5888 /* Build AVL tree from a sorted chain. */
5889
5890 static void
5891 set_nonincremental_init (void)
5892 {
5893 unsigned HOST_WIDE_INT ix;
5894 tree index, value;
5895
5896 if (TREE_CODE (constructor_type) != RECORD_TYPE
5897 && TREE_CODE (constructor_type) != ARRAY_TYPE)
5898 return;
5899
5900 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
5901 add_pending_init (index, value);
5902 constructor_elements = 0;
5903 if (TREE_CODE (constructor_type) == RECORD_TYPE)
5904 {
5905 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
5906 /* Skip any nameless bit fields at the beginning. */
5907 while (constructor_unfilled_fields != 0
5908 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
5909 && DECL_NAME (constructor_unfilled_fields) == 0)
5910 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5911
5912 }
5913 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5914 {
5915 if (TYPE_DOMAIN (constructor_type))
5916 constructor_unfilled_index
5917 = convert (bitsizetype,
5918 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5919 else
5920 constructor_unfilled_index = bitsize_zero_node;
5921 }
5922 constructor_incremental = 0;
5923 }
5924
5925 /* Build AVL tree from a string constant. */
5926
5927 static void
5928 set_nonincremental_init_from_string (tree str)
5929 {
5930 tree value, purpose, type;
5931 HOST_WIDE_INT val[2];
5932 const char *p, *end;
5933 int byte, wchar_bytes, charwidth, bitpos;
5934
5935 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
5936
5937 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5938 == TYPE_PRECISION (char_type_node))
5939 wchar_bytes = 1;
5940 else
5941 {
5942 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5943 == TYPE_PRECISION (wchar_type_node));
5944 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
5945 }
5946 charwidth = TYPE_PRECISION (char_type_node);
5947 type = TREE_TYPE (constructor_type);
5948 p = TREE_STRING_POINTER (str);
5949 end = p + TREE_STRING_LENGTH (str);
5950
5951 for (purpose = bitsize_zero_node;
5952 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
5953 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
5954 {
5955 if (wchar_bytes == 1)
5956 {
5957 val[1] = (unsigned char) *p++;
5958 val[0] = 0;
5959 }
5960 else
5961 {
5962 val[0] = 0;
5963 val[1] = 0;
5964 for (byte = 0; byte < wchar_bytes; byte++)
5965 {
5966 if (BYTES_BIG_ENDIAN)
5967 bitpos = (wchar_bytes - byte - 1) * charwidth;
5968 else
5969 bitpos = byte * charwidth;
5970 val[bitpos < HOST_BITS_PER_WIDE_INT]
5971 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
5972 << (bitpos % HOST_BITS_PER_WIDE_INT);
5973 }
5974 }
5975
5976 if (!TYPE_UNSIGNED (type))
5977 {
5978 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
5979 if (bitpos < HOST_BITS_PER_WIDE_INT)
5980 {
5981 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
5982 {
5983 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
5984 val[0] = -1;
5985 }
5986 }
5987 else if (bitpos == HOST_BITS_PER_WIDE_INT)
5988 {
5989 if (val[1] < 0)
5990 val[0] = -1;
5991 }
5992 else if (val[0] & (((HOST_WIDE_INT) 1)
5993 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
5994 val[0] |= ((HOST_WIDE_INT) -1)
5995 << (bitpos - HOST_BITS_PER_WIDE_INT);
5996 }
5997
5998 value = build_int_cst_wide (type, val[1], val[0]);
5999 add_pending_init (purpose, value);
6000 }
6001
6002 constructor_incremental = 0;
6003 }
6004
6005 /* Return value of FIELD in pending initializer or zero if the field was
6006 not initialized yet. */
6007
6008 static tree
6009 find_init_member (tree field)
6010 {
6011 struct init_node *p;
6012
6013 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6014 {
6015 if (constructor_incremental
6016 && tree_int_cst_lt (field, constructor_unfilled_index))
6017 set_nonincremental_init ();
6018
6019 p = constructor_pending_elts;
6020 while (p)
6021 {
6022 if (tree_int_cst_lt (field, p->purpose))
6023 p = p->left;
6024 else if (tree_int_cst_lt (p->purpose, field))
6025 p = p->right;
6026 else
6027 return p->value;
6028 }
6029 }
6030 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6031 {
6032 tree bitpos = bit_position (field);
6033
6034 if (constructor_incremental
6035 && (!constructor_unfilled_fields
6036 || tree_int_cst_lt (bitpos,
6037 bit_position (constructor_unfilled_fields))))
6038 set_nonincremental_init ();
6039
6040 p = constructor_pending_elts;
6041 while (p)
6042 {
6043 if (field == p->purpose)
6044 return p->value;
6045 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6046 p = p->left;
6047 else
6048 p = p->right;
6049 }
6050 }
6051 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6052 {
6053 if (!VEC_empty (constructor_elt, constructor_elements)
6054 && (VEC_last (constructor_elt, constructor_elements)->index
6055 == field))
6056 return VEC_last (constructor_elt, constructor_elements)->value;
6057 }
6058 return 0;
6059 }
6060
6061 /* "Output" the next constructor element.
6062 At top level, really output it to assembler code now.
6063 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6064 TYPE is the data type that the containing data type wants here.
6065 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6066 If VALUE is a string constant, STRICT_STRING is true if it is
6067 unparenthesized or we should not warn here for it being parenthesized.
6068 For other types of VALUE, STRICT_STRING is not used.
6069
6070 PENDING if non-nil means output pending elements that belong
6071 right after this element. (PENDING is normally 1;
6072 it is 0 while outputting pending elements, to avoid recursion.) */
6073
6074 static void
6075 output_init_element (tree value, bool strict_string, tree type, tree field,
6076 int pending)
6077 {
6078 constructor_elt *celt;
6079
6080 if (type == error_mark_node || value == error_mark_node)
6081 {
6082 constructor_erroneous = 1;
6083 return;
6084 }
6085 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6086 && (TREE_CODE (value) == STRING_CST
6087 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6088 && !(TREE_CODE (value) == STRING_CST
6089 && TREE_CODE (type) == ARRAY_TYPE
6090 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6091 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6092 TYPE_MAIN_VARIANT (type)))
6093 value = array_to_pointer_conversion (value);
6094
6095 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6096 && require_constant_value && !flag_isoc99 && pending)
6097 {
6098 /* As an extension, allow initializing objects with static storage
6099 duration with compound literals (which are then treated just as
6100 the brace enclosed list they contain). */
6101 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6102 value = DECL_INITIAL (decl);
6103 }
6104
6105 if (value == error_mark_node)
6106 constructor_erroneous = 1;
6107 else if (!TREE_CONSTANT (value))
6108 constructor_constant = 0;
6109 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6110 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6111 || TREE_CODE (constructor_type) == UNION_TYPE)
6112 && DECL_C_BIT_FIELD (field)
6113 && TREE_CODE (value) != INTEGER_CST))
6114 constructor_simple = 0;
6115
6116 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6117 {
6118 if (require_constant_value)
6119 {
6120 error_init ("initializer element is not constant");
6121 value = error_mark_node;
6122 }
6123 else if (require_constant_elements)
6124 pedwarn ("initializer element is not computable at load time");
6125 }
6126
6127 /* If this field is empty (and not at the end of structure),
6128 don't do anything other than checking the initializer. */
6129 if (field
6130 && (TREE_TYPE (field) == error_mark_node
6131 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6132 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6133 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6134 || TREE_CHAIN (field)))))
6135 return;
6136
6137 value = digest_init (type, value, strict_string, require_constant_value);
6138 if (value == error_mark_node)
6139 {
6140 constructor_erroneous = 1;
6141 return;
6142 }
6143
6144 /* If this element doesn't come next in sequence,
6145 put it on constructor_pending_elts. */
6146 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6147 && (!constructor_incremental
6148 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6149 {
6150 if (constructor_incremental
6151 && tree_int_cst_lt (field, constructor_unfilled_index))
6152 set_nonincremental_init ();
6153
6154 add_pending_init (field, value);
6155 return;
6156 }
6157 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6158 && (!constructor_incremental
6159 || field != constructor_unfilled_fields))
6160 {
6161 /* We do this for records but not for unions. In a union,
6162 no matter which field is specified, it can be initialized
6163 right away since it starts at the beginning of the union. */
6164 if (constructor_incremental)
6165 {
6166 if (!constructor_unfilled_fields)
6167 set_nonincremental_init ();
6168 else
6169 {
6170 tree bitpos, unfillpos;
6171
6172 bitpos = bit_position (field);
6173 unfillpos = bit_position (constructor_unfilled_fields);
6174
6175 if (tree_int_cst_lt (bitpos, unfillpos))
6176 set_nonincremental_init ();
6177 }
6178 }
6179
6180 add_pending_init (field, value);
6181 return;
6182 }
6183 else if (TREE_CODE (constructor_type) == UNION_TYPE
6184 && !VEC_empty (constructor_elt, constructor_elements))
6185 {
6186 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6187 constructor_elements)->value))
6188 warning_init ("initialized field with side-effects overwritten");
6189 else if (warn_override_init)
6190 warning_init ("initialized field overwritten");
6191
6192 /* We can have just one union field set. */
6193 constructor_elements = 0;
6194 }
6195
6196 /* Otherwise, output this element either to
6197 constructor_elements or to the assembler file. */
6198
6199 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6200 celt->index = field;
6201 celt->value = value;
6202
6203 /* Advance the variable that indicates sequential elements output. */
6204 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6205 constructor_unfilled_index
6206 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6207 bitsize_one_node);
6208 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6209 {
6210 constructor_unfilled_fields
6211 = TREE_CHAIN (constructor_unfilled_fields);
6212
6213 /* Skip any nameless bit fields. */
6214 while (constructor_unfilled_fields != 0
6215 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6216 && DECL_NAME (constructor_unfilled_fields) == 0)
6217 constructor_unfilled_fields =
6218 TREE_CHAIN (constructor_unfilled_fields);
6219 }
6220 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6221 constructor_unfilled_fields = 0;
6222
6223 /* Now output any pending elements which have become next. */
6224 if (pending)
6225 output_pending_init_elements (0);
6226 }
6227
6228 /* Output any pending elements which have become next.
6229 As we output elements, constructor_unfilled_{fields,index}
6230 advances, which may cause other elements to become next;
6231 if so, they too are output.
6232
6233 If ALL is 0, we return when there are
6234 no more pending elements to output now.
6235
6236 If ALL is 1, we output space as necessary so that
6237 we can output all the pending elements. */
6238
6239 static void
6240 output_pending_init_elements (int all)
6241 {
6242 struct init_node *elt = constructor_pending_elts;
6243 tree next;
6244
6245 retry:
6246
6247 /* Look through the whole pending tree.
6248 If we find an element that should be output now,
6249 output it. Otherwise, set NEXT to the element
6250 that comes first among those still pending. */
6251
6252 next = 0;
6253 while (elt)
6254 {
6255 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6256 {
6257 if (tree_int_cst_equal (elt->purpose,
6258 constructor_unfilled_index))
6259 output_init_element (elt->value, true,
6260 TREE_TYPE (constructor_type),
6261 constructor_unfilled_index, 0);
6262 else if (tree_int_cst_lt (constructor_unfilled_index,
6263 elt->purpose))
6264 {
6265 /* Advance to the next smaller node. */
6266 if (elt->left)
6267 elt = elt->left;
6268 else
6269 {
6270 /* We have reached the smallest node bigger than the
6271 current unfilled index. Fill the space first. */
6272 next = elt->purpose;
6273 break;
6274 }
6275 }
6276 else
6277 {
6278 /* Advance to the next bigger node. */
6279 if (elt->right)
6280 elt = elt->right;
6281 else
6282 {
6283 /* We have reached the biggest node in a subtree. Find
6284 the parent of it, which is the next bigger node. */
6285 while (elt->parent && elt->parent->right == elt)
6286 elt = elt->parent;
6287 elt = elt->parent;
6288 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6289 elt->purpose))
6290 {
6291 next = elt->purpose;
6292 break;
6293 }
6294 }
6295 }
6296 }
6297 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6298 || TREE_CODE (constructor_type) == UNION_TYPE)
6299 {
6300 tree ctor_unfilled_bitpos, elt_bitpos;
6301
6302 /* If the current record is complete we are done. */
6303 if (constructor_unfilled_fields == 0)
6304 break;
6305
6306 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6307 elt_bitpos = bit_position (elt->purpose);
6308 /* We can't compare fields here because there might be empty
6309 fields in between. */
6310 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6311 {
6312 constructor_unfilled_fields = elt->purpose;
6313 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6314 elt->purpose, 0);
6315 }
6316 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6317 {
6318 /* Advance to the next smaller node. */
6319 if (elt->left)
6320 elt = elt->left;
6321 else
6322 {
6323 /* We have reached the smallest node bigger than the
6324 current unfilled field. Fill the space first. */
6325 next = elt->purpose;
6326 break;
6327 }
6328 }
6329 else
6330 {
6331 /* Advance to the next bigger node. */
6332 if (elt->right)
6333 elt = elt->right;
6334 else
6335 {
6336 /* We have reached the biggest node in a subtree. Find
6337 the parent of it, which is the next bigger node. */
6338 while (elt->parent && elt->parent->right == elt)
6339 elt = elt->parent;
6340 elt = elt->parent;
6341 if (elt
6342 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6343 bit_position (elt->purpose))))
6344 {
6345 next = elt->purpose;
6346 break;
6347 }
6348 }
6349 }
6350 }
6351 }
6352
6353 /* Ordinarily return, but not if we want to output all
6354 and there are elements left. */
6355 if (!(all && next != 0))
6356 return;
6357
6358 /* If it's not incremental, just skip over the gap, so that after
6359 jumping to retry we will output the next successive element. */
6360 if (TREE_CODE (constructor_type) == RECORD_TYPE
6361 || TREE_CODE (constructor_type) == UNION_TYPE)
6362 constructor_unfilled_fields = next;
6363 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6364 constructor_unfilled_index = next;
6365
6366 /* ELT now points to the node in the pending tree with the next
6367 initializer to output. */
6368 goto retry;
6369 }
6370 \f
6371 /* Add one non-braced element to the current constructor level.
6372 This adjusts the current position within the constructor's type.
6373 This may also start or terminate implicit levels
6374 to handle a partly-braced initializer.
6375
6376 Once this has found the correct level for the new element,
6377 it calls output_init_element. */
6378
6379 void
6380 process_init_element (struct c_expr value)
6381 {
6382 tree orig_value = value.value;
6383 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6384 bool strict_string = value.original_code == STRING_CST;
6385
6386 designator_depth = 0;
6387 designator_erroneous = 0;
6388
6389 /* Handle superfluous braces around string cst as in
6390 char x[] = {"foo"}; */
6391 if (string_flag
6392 && constructor_type
6393 && TREE_CODE (constructor_type) == ARRAY_TYPE
6394 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6395 && integer_zerop (constructor_unfilled_index))
6396 {
6397 if (constructor_stack->replacement_value.value)
6398 error_init ("excess elements in char array initializer");
6399 constructor_stack->replacement_value = value;
6400 return;
6401 }
6402
6403 if (constructor_stack->replacement_value.value != 0)
6404 {
6405 error_init ("excess elements in struct initializer");
6406 return;
6407 }
6408
6409 /* Ignore elements of a brace group if it is entirely superfluous
6410 and has already been diagnosed. */
6411 if (constructor_type == 0)
6412 return;
6413
6414 /* If we've exhausted any levels that didn't have braces,
6415 pop them now. */
6416 while (constructor_stack->implicit)
6417 {
6418 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6419 || TREE_CODE (constructor_type) == UNION_TYPE)
6420 && constructor_fields == 0)
6421 process_init_element (pop_init_level (1));
6422 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6423 && (constructor_max_index == 0
6424 || tree_int_cst_lt (constructor_max_index,
6425 constructor_index)))
6426 process_init_element (pop_init_level (1));
6427 else
6428 break;
6429 }
6430
6431 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6432 if (constructor_range_stack)
6433 {
6434 /* If value is a compound literal and we'll be just using its
6435 content, don't put it into a SAVE_EXPR. */
6436 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6437 || !require_constant_value
6438 || flag_isoc99)
6439 value.value = save_expr (value.value);
6440 }
6441
6442 while (1)
6443 {
6444 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6445 {
6446 tree fieldtype;
6447 enum tree_code fieldcode;
6448
6449 if (constructor_fields == 0)
6450 {
6451 pedwarn_init ("excess elements in struct initializer");
6452 break;
6453 }
6454
6455 fieldtype = TREE_TYPE (constructor_fields);
6456 if (fieldtype != error_mark_node)
6457 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6458 fieldcode = TREE_CODE (fieldtype);
6459
6460 /* Error for non-static initialization of a flexible array member. */
6461 if (fieldcode == ARRAY_TYPE
6462 && !require_constant_value
6463 && TYPE_SIZE (fieldtype) == NULL_TREE
6464 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6465 {
6466 error_init ("non-static initialization of a flexible array member");
6467 break;
6468 }
6469
6470 /* Accept a string constant to initialize a subarray. */
6471 if (value.value != 0
6472 && fieldcode == ARRAY_TYPE
6473 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6474 && string_flag)
6475 value.value = orig_value;
6476 /* Otherwise, if we have come to a subaggregate,
6477 and we don't have an element of its type, push into it. */
6478 else if (value.value != 0
6479 && value.value != error_mark_node
6480 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6481 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6482 || fieldcode == UNION_TYPE))
6483 {
6484 push_init_level (1);
6485 continue;
6486 }
6487
6488 if (value.value)
6489 {
6490 push_member_name (constructor_fields);
6491 output_init_element (value.value, strict_string,
6492 fieldtype, constructor_fields, 1);
6493 RESTORE_SPELLING_DEPTH (constructor_depth);
6494 }
6495 else
6496 /* Do the bookkeeping for an element that was
6497 directly output as a constructor. */
6498 {
6499 /* For a record, keep track of end position of last field. */
6500 if (DECL_SIZE (constructor_fields))
6501 constructor_bit_index
6502 = size_binop (PLUS_EXPR,
6503 bit_position (constructor_fields),
6504 DECL_SIZE (constructor_fields));
6505
6506 /* If the current field was the first one not yet written out,
6507 it isn't now, so update. */
6508 if (constructor_unfilled_fields == constructor_fields)
6509 {
6510 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6511 /* Skip any nameless bit fields. */
6512 while (constructor_unfilled_fields != 0
6513 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6514 && DECL_NAME (constructor_unfilled_fields) == 0)
6515 constructor_unfilled_fields =
6516 TREE_CHAIN (constructor_unfilled_fields);
6517 }
6518 }
6519
6520 constructor_fields = TREE_CHAIN (constructor_fields);
6521 /* Skip any nameless bit fields at the beginning. */
6522 while (constructor_fields != 0
6523 && DECL_C_BIT_FIELD (constructor_fields)
6524 && DECL_NAME (constructor_fields) == 0)
6525 constructor_fields = TREE_CHAIN (constructor_fields);
6526 }
6527 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6528 {
6529 tree fieldtype;
6530 enum tree_code fieldcode;
6531
6532 if (constructor_fields == 0)
6533 {
6534 pedwarn_init ("excess elements in union initializer");
6535 break;
6536 }
6537
6538 fieldtype = TREE_TYPE (constructor_fields);
6539 if (fieldtype != error_mark_node)
6540 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6541 fieldcode = TREE_CODE (fieldtype);
6542
6543 /* Warn that traditional C rejects initialization of unions.
6544 We skip the warning if the value is zero. This is done
6545 under the assumption that the zero initializer in user
6546 code appears conditioned on e.g. __STDC__ to avoid
6547 "missing initializer" warnings and relies on default
6548 initialization to zero in the traditional C case.
6549 We also skip the warning if the initializer is designated,
6550 again on the assumption that this must be conditional on
6551 __STDC__ anyway (and we've already complained about the
6552 member-designator already). */
6553 if (!in_system_header && !constructor_designated
6554 && !(value.value && (integer_zerop (value.value)
6555 || real_zerop (value.value))))
6556 warning (OPT_Wtraditional, "traditional C rejects initialization "
6557 "of unions");
6558
6559 /* Accept a string constant to initialize a subarray. */
6560 if (value.value != 0
6561 && fieldcode == ARRAY_TYPE
6562 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6563 && string_flag)
6564 value.value = orig_value;
6565 /* Otherwise, if we have come to a subaggregate,
6566 and we don't have an element of its type, push into it. */
6567 else if (value.value != 0
6568 && value.value != error_mark_node
6569 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6570 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6571 || fieldcode == UNION_TYPE))
6572 {
6573 push_init_level (1);
6574 continue;
6575 }
6576
6577 if (value.value)
6578 {
6579 push_member_name (constructor_fields);
6580 output_init_element (value.value, strict_string,
6581 fieldtype, constructor_fields, 1);
6582 RESTORE_SPELLING_DEPTH (constructor_depth);
6583 }
6584 else
6585 /* Do the bookkeeping for an element that was
6586 directly output as a constructor. */
6587 {
6588 constructor_bit_index = DECL_SIZE (constructor_fields);
6589 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6590 }
6591
6592 constructor_fields = 0;
6593 }
6594 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6595 {
6596 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6597 enum tree_code eltcode = TREE_CODE (elttype);
6598
6599 /* Accept a string constant to initialize a subarray. */
6600 if (value.value != 0
6601 && eltcode == ARRAY_TYPE
6602 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6603 && string_flag)
6604 value.value = orig_value;
6605 /* Otherwise, if we have come to a subaggregate,
6606 and we don't have an element of its type, push into it. */
6607 else if (value.value != 0
6608 && value.value != error_mark_node
6609 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6610 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6611 || eltcode == UNION_TYPE))
6612 {
6613 push_init_level (1);
6614 continue;
6615 }
6616
6617 if (constructor_max_index != 0
6618 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6619 || integer_all_onesp (constructor_max_index)))
6620 {
6621 pedwarn_init ("excess elements in array initializer");
6622 break;
6623 }
6624
6625 /* Now output the actual element. */
6626 if (value.value)
6627 {
6628 push_array_bounds (tree_low_cst (constructor_index, 1));
6629 output_init_element (value.value, strict_string,
6630 elttype, constructor_index, 1);
6631 RESTORE_SPELLING_DEPTH (constructor_depth);
6632 }
6633
6634 constructor_index
6635 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6636
6637 if (!value.value)
6638 /* If we are doing the bookkeeping for an element that was
6639 directly output as a constructor, we must update
6640 constructor_unfilled_index. */
6641 constructor_unfilled_index = constructor_index;
6642 }
6643 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6644 {
6645 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6646
6647 /* Do a basic check of initializer size. Note that vectors
6648 always have a fixed size derived from their type. */
6649 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6650 {
6651 pedwarn_init ("excess elements in vector initializer");
6652 break;
6653 }
6654
6655 /* Now output the actual element. */
6656 if (value.value)
6657 output_init_element (value.value, strict_string,
6658 elttype, constructor_index, 1);
6659
6660 constructor_index
6661 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6662
6663 if (!value.value)
6664 /* If we are doing the bookkeeping for an element that was
6665 directly output as a constructor, we must update
6666 constructor_unfilled_index. */
6667 constructor_unfilled_index = constructor_index;
6668 }
6669
6670 /* Handle the sole element allowed in a braced initializer
6671 for a scalar variable. */
6672 else if (constructor_type != error_mark_node
6673 && constructor_fields == 0)
6674 {
6675 pedwarn_init ("excess elements in scalar initializer");
6676 break;
6677 }
6678 else
6679 {
6680 if (value.value)
6681 output_init_element (value.value, strict_string,
6682 constructor_type, NULL_TREE, 1);
6683 constructor_fields = 0;
6684 }
6685
6686 /* Handle range initializers either at this level or anywhere higher
6687 in the designator stack. */
6688 if (constructor_range_stack)
6689 {
6690 struct constructor_range_stack *p, *range_stack;
6691 int finish = 0;
6692
6693 range_stack = constructor_range_stack;
6694 constructor_range_stack = 0;
6695 while (constructor_stack != range_stack->stack)
6696 {
6697 gcc_assert (constructor_stack->implicit);
6698 process_init_element (pop_init_level (1));
6699 }
6700 for (p = range_stack;
6701 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6702 p = p->prev)
6703 {
6704 gcc_assert (constructor_stack->implicit);
6705 process_init_element (pop_init_level (1));
6706 }
6707
6708 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6709 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6710 finish = 1;
6711
6712 while (1)
6713 {
6714 constructor_index = p->index;
6715 constructor_fields = p->fields;
6716 if (finish && p->range_end && p->index == p->range_start)
6717 {
6718 finish = 0;
6719 p->prev = 0;
6720 }
6721 p = p->next;
6722 if (!p)
6723 break;
6724 push_init_level (2);
6725 p->stack = constructor_stack;
6726 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6727 p->index = p->range_start;
6728 }
6729
6730 if (!finish)
6731 constructor_range_stack = range_stack;
6732 continue;
6733 }
6734
6735 break;
6736 }
6737
6738 constructor_range_stack = 0;
6739 }
6740 \f
6741 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6742 (guaranteed to be 'volatile' or null) and ARGS (represented using
6743 an ASM_EXPR node). */
6744 tree
6745 build_asm_stmt (tree cv_qualifier, tree args)
6746 {
6747 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6748 ASM_VOLATILE_P (args) = 1;
6749 return add_stmt (args);
6750 }
6751
6752 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6753 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6754 SIMPLE indicates whether there was anything at all after the
6755 string in the asm expression -- asm("blah") and asm("blah" : )
6756 are subtly different. We use a ASM_EXPR node to represent this. */
6757 tree
6758 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6759 bool simple)
6760 {
6761 tree tail;
6762 tree args;
6763 int i;
6764 const char *constraint;
6765 const char **oconstraints;
6766 bool allows_mem, allows_reg, is_inout;
6767 int ninputs, noutputs;
6768
6769 ninputs = list_length (inputs);
6770 noutputs = list_length (outputs);
6771 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6772
6773 string = resolve_asm_operand_names (string, outputs, inputs);
6774
6775 /* Remove output conversions that change the type but not the mode. */
6776 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6777 {
6778 tree output = TREE_VALUE (tail);
6779
6780 /* ??? Really, this should not be here. Users should be using a
6781 proper lvalue, dammit. But there's a long history of using casts
6782 in the output operands. In cases like longlong.h, this becomes a
6783 primitive form of typechecking -- if the cast can be removed, then
6784 the output operand had a type of the proper width; otherwise we'll
6785 get an error. Gross, but ... */
6786 STRIP_NOPS (output);
6787
6788 if (!lvalue_or_else (output, lv_asm))
6789 output = error_mark_node;
6790
6791 if (output != error_mark_node
6792 && (TREE_READONLY (output)
6793 || TYPE_READONLY (TREE_TYPE (output))
6794 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6795 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6796 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6797 readonly_error (output, lv_asm);
6798
6799 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6800 oconstraints[i] = constraint;
6801
6802 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6803 &allows_mem, &allows_reg, &is_inout))
6804 {
6805 /* If the operand is going to end up in memory,
6806 mark it addressable. */
6807 if (!allows_reg && !c_mark_addressable (output))
6808 output = error_mark_node;
6809 }
6810 else
6811 output = error_mark_node;
6812
6813 TREE_VALUE (tail) = output;
6814 }
6815
6816 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
6817 {
6818 tree input;
6819
6820 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6821 input = TREE_VALUE (tail);
6822
6823 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
6824 oconstraints, &allows_mem, &allows_reg))
6825 {
6826 /* If the operand is going to end up in memory,
6827 mark it addressable. */
6828 if (!allows_reg && allows_mem)
6829 {
6830 /* Strip the nops as we allow this case. FIXME, this really
6831 should be rejected or made deprecated. */
6832 STRIP_NOPS (input);
6833 if (!c_mark_addressable (input))
6834 input = error_mark_node;
6835 }
6836 }
6837 else
6838 input = error_mark_node;
6839
6840 TREE_VALUE (tail) = input;
6841 }
6842
6843 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
6844
6845 /* asm statements without outputs, including simple ones, are treated
6846 as volatile. */
6847 ASM_INPUT_P (args) = simple;
6848 ASM_VOLATILE_P (args) = (noutputs == 0);
6849
6850 return args;
6851 }
6852 \f
6853 /* Generate a goto statement to LABEL. */
6854
6855 tree
6856 c_finish_goto_label (tree label)
6857 {
6858 tree decl = lookup_label (label);
6859 if (!decl)
6860 return NULL_TREE;
6861
6862 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
6863 {
6864 error ("jump into statement expression");
6865 return NULL_TREE;
6866 }
6867
6868 if (C_DECL_UNJUMPABLE_VM (decl))
6869 {
6870 error ("jump into scope of identifier with variably modified type");
6871 return NULL_TREE;
6872 }
6873
6874 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
6875 {
6876 /* No jump from outside this statement expression context, so
6877 record that there is a jump from within this context. */
6878 struct c_label_list *nlist;
6879 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6880 nlist->next = label_context_stack_se->labels_used;
6881 nlist->label = decl;
6882 label_context_stack_se->labels_used = nlist;
6883 }
6884
6885 if (!C_DECL_UNDEFINABLE_VM (decl))
6886 {
6887 /* No jump from outside this context context of identifiers with
6888 variably modified type, so record that there is a jump from
6889 within this context. */
6890 struct c_label_list *nlist;
6891 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6892 nlist->next = label_context_stack_vm->labels_used;
6893 nlist->label = decl;
6894 label_context_stack_vm->labels_used = nlist;
6895 }
6896
6897 TREE_USED (decl) = 1;
6898 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
6899 }
6900
6901 /* Generate a computed goto statement to EXPR. */
6902
6903 tree
6904 c_finish_goto_ptr (tree expr)
6905 {
6906 if (pedantic)
6907 pedwarn ("ISO C forbids %<goto *expr;%>");
6908 expr = convert (ptr_type_node, expr);
6909 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
6910 }
6911
6912 /* Generate a C `return' statement. RETVAL is the expression for what
6913 to return, or a null pointer for `return;' with no value. */
6914
6915 tree
6916 c_finish_return (tree retval)
6917 {
6918 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
6919 bool no_warning = false;
6920
6921 if (TREE_THIS_VOLATILE (current_function_decl))
6922 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6923
6924 if (!retval)
6925 {
6926 current_function_returns_null = 1;
6927 if ((warn_return_type || flag_isoc99)
6928 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
6929 {
6930 pedwarn_c99 ("%<return%> with no value, in "
6931 "function returning non-void");
6932 no_warning = true;
6933 }
6934 }
6935 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
6936 {
6937 current_function_returns_null = 1;
6938 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
6939 pedwarn ("%<return%> with a value, in function returning void");
6940 }
6941 else
6942 {
6943 tree t = convert_for_assignment (valtype, retval, ic_return,
6944 NULL_TREE, NULL_TREE, 0);
6945 tree res = DECL_RESULT (current_function_decl);
6946 tree inner;
6947
6948 current_function_returns_value = 1;
6949 if (t == error_mark_node)
6950 return NULL_TREE;
6951
6952 inner = t = convert (TREE_TYPE (res), t);
6953
6954 /* Strip any conversions, additions, and subtractions, and see if
6955 we are returning the address of a local variable. Warn if so. */
6956 while (1)
6957 {
6958 switch (TREE_CODE (inner))
6959 {
6960 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
6961 case PLUS_EXPR:
6962 inner = TREE_OPERAND (inner, 0);
6963 continue;
6964
6965 case MINUS_EXPR:
6966 /* If the second operand of the MINUS_EXPR has a pointer
6967 type (or is converted from it), this may be valid, so
6968 don't give a warning. */
6969 {
6970 tree op1 = TREE_OPERAND (inner, 1);
6971
6972 while (!POINTER_TYPE_P (TREE_TYPE (op1))
6973 && (TREE_CODE (op1) == NOP_EXPR
6974 || TREE_CODE (op1) == NON_LVALUE_EXPR
6975 || TREE_CODE (op1) == CONVERT_EXPR))
6976 op1 = TREE_OPERAND (op1, 0);
6977
6978 if (POINTER_TYPE_P (TREE_TYPE (op1)))
6979 break;
6980
6981 inner = TREE_OPERAND (inner, 0);
6982 continue;
6983 }
6984
6985 case ADDR_EXPR:
6986 inner = TREE_OPERAND (inner, 0);
6987
6988 while (REFERENCE_CLASS_P (inner)
6989 && TREE_CODE (inner) != INDIRECT_REF)
6990 inner = TREE_OPERAND (inner, 0);
6991
6992 if (DECL_P (inner)
6993 && !DECL_EXTERNAL (inner)
6994 && !TREE_STATIC (inner)
6995 && DECL_CONTEXT (inner) == current_function_decl)
6996 warning (0, "function returns address of local variable");
6997 break;
6998
6999 default:
7000 break;
7001 }
7002
7003 break;
7004 }
7005
7006 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7007 }
7008
7009 ret_stmt = build_stmt (RETURN_EXPR, retval);
7010 TREE_NO_WARNING (ret_stmt) |= no_warning;
7011 return add_stmt (ret_stmt);
7012 }
7013 \f
7014 struct c_switch {
7015 /* The SWITCH_EXPR being built. */
7016 tree switch_expr;
7017
7018 /* The original type of the testing expression, i.e. before the
7019 default conversion is applied. */
7020 tree orig_type;
7021
7022 /* A splay-tree mapping the low element of a case range to the high
7023 element, or NULL_TREE if there is no high element. Used to
7024 determine whether or not a new case label duplicates an old case
7025 label. We need a tree, rather than simply a hash table, because
7026 of the GNU case range extension. */
7027 splay_tree cases;
7028
7029 /* Number of nested statement expressions within this switch
7030 statement; if nonzero, case and default labels may not
7031 appear. */
7032 unsigned int blocked_stmt_expr;
7033
7034 /* Scope of outermost declarations of identifiers with variably
7035 modified type within this switch statement; if nonzero, case and
7036 default labels may not appear. */
7037 unsigned int blocked_vm;
7038
7039 /* The next node on the stack. */
7040 struct c_switch *next;
7041 };
7042
7043 /* A stack of the currently active switch statements. The innermost
7044 switch statement is on the top of the stack. There is no need to
7045 mark the stack for garbage collection because it is only active
7046 during the processing of the body of a function, and we never
7047 collect at that point. */
7048
7049 struct c_switch *c_switch_stack;
7050
7051 /* Start a C switch statement, testing expression EXP. Return the new
7052 SWITCH_EXPR. */
7053
7054 tree
7055 c_start_case (tree exp)
7056 {
7057 tree orig_type = error_mark_node;
7058 struct c_switch *cs;
7059
7060 if (exp != error_mark_node)
7061 {
7062 orig_type = TREE_TYPE (exp);
7063
7064 if (!INTEGRAL_TYPE_P (orig_type))
7065 {
7066 if (orig_type != error_mark_node)
7067 {
7068 error ("switch quantity not an integer");
7069 orig_type = error_mark_node;
7070 }
7071 exp = integer_zero_node;
7072 }
7073 else
7074 {
7075 tree type = TYPE_MAIN_VARIANT (orig_type);
7076
7077 if (!in_system_header
7078 && (type == long_integer_type_node
7079 || type == long_unsigned_type_node))
7080 warning (OPT_Wtraditional, "%<long%> switch expression not "
7081 "converted to %<int%> in ISO C");
7082
7083 exp = default_conversion (exp);
7084 }
7085 }
7086
7087 /* Add this new SWITCH_EXPR to the stack. */
7088 cs = XNEW (struct c_switch);
7089 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7090 cs->orig_type = orig_type;
7091 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7092 cs->blocked_stmt_expr = 0;
7093 cs->blocked_vm = 0;
7094 cs->next = c_switch_stack;
7095 c_switch_stack = cs;
7096
7097 return add_stmt (cs->switch_expr);
7098 }
7099
7100 /* Process a case label. */
7101
7102 tree
7103 do_case (tree low_value, tree high_value)
7104 {
7105 tree label = NULL_TREE;
7106
7107 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7108 && !c_switch_stack->blocked_vm)
7109 {
7110 label = c_add_case_label (c_switch_stack->cases,
7111 SWITCH_COND (c_switch_stack->switch_expr),
7112 c_switch_stack->orig_type,
7113 low_value, high_value);
7114 if (label == error_mark_node)
7115 label = NULL_TREE;
7116 }
7117 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7118 {
7119 if (low_value)
7120 error ("case label in statement expression not containing "
7121 "enclosing switch statement");
7122 else
7123 error ("%<default%> label in statement expression not containing "
7124 "enclosing switch statement");
7125 }
7126 else if (c_switch_stack && c_switch_stack->blocked_vm)
7127 {
7128 if (low_value)
7129 error ("case label in scope of identifier with variably modified "
7130 "type not containing enclosing switch statement");
7131 else
7132 error ("%<default%> label in scope of identifier with variably "
7133 "modified type not containing enclosing switch statement");
7134 }
7135 else if (low_value)
7136 error ("case label not within a switch statement");
7137 else
7138 error ("%<default%> label not within a switch statement");
7139
7140 return label;
7141 }
7142
7143 /* Finish the switch statement. */
7144
7145 void
7146 c_finish_case (tree body)
7147 {
7148 struct c_switch *cs = c_switch_stack;
7149 location_t switch_location;
7150
7151 SWITCH_BODY (cs->switch_expr) = body;
7152
7153 /* We must not be within a statement expression nested in the switch
7154 at this point; we might, however, be within the scope of an
7155 identifier with variably modified type nested in the switch. */
7156 gcc_assert (!cs->blocked_stmt_expr);
7157
7158 /* Emit warnings as needed. */
7159 if (EXPR_HAS_LOCATION (cs->switch_expr))
7160 switch_location = EXPR_LOCATION (cs->switch_expr);
7161 else
7162 switch_location = input_location;
7163 c_do_switch_warnings (cs->cases, switch_location,
7164 TREE_TYPE (cs->switch_expr),
7165 SWITCH_COND (cs->switch_expr));
7166
7167 /* Pop the stack. */
7168 c_switch_stack = cs->next;
7169 splay_tree_delete (cs->cases);
7170 XDELETE (cs);
7171 }
7172 \f
7173 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7174 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7175 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7176 statement, and was not surrounded with parenthesis. */
7177
7178 void
7179 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7180 tree else_block, bool nested_if)
7181 {
7182 tree stmt;
7183
7184 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7185 if (warn_parentheses && nested_if && else_block == NULL)
7186 {
7187 tree inner_if = then_block;
7188
7189 /* We know from the grammar productions that there is an IF nested
7190 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7191 it might not be exactly THEN_BLOCK, but should be the last
7192 non-container statement within. */
7193 while (1)
7194 switch (TREE_CODE (inner_if))
7195 {
7196 case COND_EXPR:
7197 goto found;
7198 case BIND_EXPR:
7199 inner_if = BIND_EXPR_BODY (inner_if);
7200 break;
7201 case STATEMENT_LIST:
7202 inner_if = expr_last (then_block);
7203 break;
7204 case TRY_FINALLY_EXPR:
7205 case TRY_CATCH_EXPR:
7206 inner_if = TREE_OPERAND (inner_if, 0);
7207 break;
7208 default:
7209 gcc_unreachable ();
7210 }
7211 found:
7212
7213 if (COND_EXPR_ELSE (inner_if))
7214 warning (OPT_Wparentheses,
7215 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7216 &if_locus);
7217 }
7218
7219 empty_body_warning (then_block, else_block);
7220
7221 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7222 SET_EXPR_LOCATION (stmt, if_locus);
7223 add_stmt (stmt);
7224 }
7225
7226 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7227 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7228 is false for DO loops. INCR is the FOR increment expression. BODY is
7229 the statement controlled by the loop. BLAB is the break label. CLAB is
7230 the continue label. Everything is allowed to be NULL. */
7231
7232 void
7233 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7234 tree blab, tree clab, bool cond_is_first)
7235 {
7236 tree entry = NULL, exit = NULL, t;
7237
7238 /* If the condition is zero don't generate a loop construct. */
7239 if (cond && integer_zerop (cond))
7240 {
7241 if (cond_is_first)
7242 {
7243 t = build_and_jump (&blab);
7244 SET_EXPR_LOCATION (t, start_locus);
7245 add_stmt (t);
7246 }
7247 }
7248 else
7249 {
7250 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7251
7252 /* If we have an exit condition, then we build an IF with gotos either
7253 out of the loop, or to the top of it. If there's no exit condition,
7254 then we just build a jump back to the top. */
7255 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7256
7257 if (cond && !integer_nonzerop (cond))
7258 {
7259 /* Canonicalize the loop condition to the end. This means
7260 generating a branch to the loop condition. Reuse the
7261 continue label, if possible. */
7262 if (cond_is_first)
7263 {
7264 if (incr || !clab)
7265 {
7266 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7267 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7268 }
7269 else
7270 t = build1 (GOTO_EXPR, void_type_node, clab);
7271 SET_EXPR_LOCATION (t, start_locus);
7272 add_stmt (t);
7273 }
7274
7275 t = build_and_jump (&blab);
7276 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7277 if (cond_is_first)
7278 SET_EXPR_LOCATION (exit, start_locus);
7279 else
7280 SET_EXPR_LOCATION (exit, input_location);
7281 }
7282
7283 add_stmt (top);
7284 }
7285
7286 if (body)
7287 add_stmt (body);
7288 if (clab)
7289 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7290 if (incr)
7291 add_stmt (incr);
7292 if (entry)
7293 add_stmt (entry);
7294 if (exit)
7295 add_stmt (exit);
7296 if (blab)
7297 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7298 }
7299
7300 tree
7301 c_finish_bc_stmt (tree *label_p, bool is_break)
7302 {
7303 bool skip;
7304 tree label = *label_p;
7305
7306 /* In switch statements break is sometimes stylistically used after
7307 a return statement. This can lead to spurious warnings about
7308 control reaching the end of a non-void function when it is
7309 inlined. Note that we are calling block_may_fallthru with
7310 language specific tree nodes; this works because
7311 block_may_fallthru returns true when given something it does not
7312 understand. */
7313 skip = !block_may_fallthru (cur_stmt_list);
7314
7315 if (!label)
7316 {
7317 if (!skip)
7318 *label_p = label = create_artificial_label ();
7319 }
7320 else if (TREE_CODE (label) == LABEL_DECL)
7321 ;
7322 else switch (TREE_INT_CST_LOW (label))
7323 {
7324 case 0:
7325 if (is_break)
7326 error ("break statement not within loop or switch");
7327 else
7328 error ("continue statement not within a loop");
7329 return NULL_TREE;
7330
7331 case 1:
7332 gcc_assert (is_break);
7333 error ("break statement used with OpenMP for loop");
7334 return NULL_TREE;
7335
7336 default:
7337 gcc_unreachable ();
7338 }
7339
7340 if (skip)
7341 return NULL_TREE;
7342
7343 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7344 }
7345
7346 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7347
7348 static void
7349 emit_side_effect_warnings (tree expr)
7350 {
7351 if (expr == error_mark_node)
7352 ;
7353 else if (!TREE_SIDE_EFFECTS (expr))
7354 {
7355 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7356 warning (0, "%Hstatement with no effect",
7357 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7358 }
7359 else if (warn_unused_value)
7360 warn_if_unused_value (expr, input_location);
7361 }
7362
7363 /* Process an expression as if it were a complete statement. Emit
7364 diagnostics, but do not call ADD_STMT. */
7365
7366 tree
7367 c_process_expr_stmt (tree expr)
7368 {
7369 if (!expr)
7370 return NULL_TREE;
7371
7372 if (warn_sequence_point)
7373 verify_sequence_points (expr);
7374
7375 if (TREE_TYPE (expr) != error_mark_node
7376 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7377 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7378 error ("expression statement has incomplete type");
7379
7380 /* If we're not processing a statement expression, warn about unused values.
7381 Warnings for statement expressions will be emitted later, once we figure
7382 out which is the result. */
7383 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7384 && (extra_warnings || warn_unused_value))
7385 emit_side_effect_warnings (expr);
7386
7387 /* If the expression is not of a type to which we cannot assign a line
7388 number, wrap the thing in a no-op NOP_EXPR. */
7389 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7390 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7391
7392 if (CAN_HAVE_LOCATION_P (expr))
7393 SET_EXPR_LOCATION (expr, input_location);
7394
7395 return expr;
7396 }
7397
7398 /* Emit an expression as a statement. */
7399
7400 tree
7401 c_finish_expr_stmt (tree expr)
7402 {
7403 if (expr)
7404 return add_stmt (c_process_expr_stmt (expr));
7405 else
7406 return NULL;
7407 }
7408
7409 /* Do the opposite and emit a statement as an expression. To begin,
7410 create a new binding level and return it. */
7411
7412 tree
7413 c_begin_stmt_expr (void)
7414 {
7415 tree ret;
7416 struct c_label_context_se *nstack;
7417 struct c_label_list *glist;
7418
7419 /* We must force a BLOCK for this level so that, if it is not expanded
7420 later, there is a way to turn off the entire subtree of blocks that
7421 are contained in it. */
7422 keep_next_level ();
7423 ret = c_begin_compound_stmt (true);
7424 if (c_switch_stack)
7425 {
7426 c_switch_stack->blocked_stmt_expr++;
7427 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7428 }
7429 for (glist = label_context_stack_se->labels_used;
7430 glist != NULL;
7431 glist = glist->next)
7432 {
7433 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7434 }
7435 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7436 nstack->labels_def = NULL;
7437 nstack->labels_used = NULL;
7438 nstack->next = label_context_stack_se;
7439 label_context_stack_se = nstack;
7440
7441 /* Mark the current statement list as belonging to a statement list. */
7442 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7443
7444 return ret;
7445 }
7446
7447 tree
7448 c_finish_stmt_expr (tree body)
7449 {
7450 tree last, type, tmp, val;
7451 tree *last_p;
7452 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7453
7454 body = c_end_compound_stmt (body, true);
7455 if (c_switch_stack)
7456 {
7457 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7458 c_switch_stack->blocked_stmt_expr--;
7459 }
7460 /* It is no longer possible to jump to labels defined within this
7461 statement expression. */
7462 for (dlist = label_context_stack_se->labels_def;
7463 dlist != NULL;
7464 dlist = dlist->next)
7465 {
7466 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7467 }
7468 /* It is again possible to define labels with a goto just outside
7469 this statement expression. */
7470 for (glist = label_context_stack_se->next->labels_used;
7471 glist != NULL;
7472 glist = glist->next)
7473 {
7474 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7475 glist_prev = glist;
7476 }
7477 if (glist_prev != NULL)
7478 glist_prev->next = label_context_stack_se->labels_used;
7479 else
7480 label_context_stack_se->next->labels_used
7481 = label_context_stack_se->labels_used;
7482 label_context_stack_se = label_context_stack_se->next;
7483
7484 /* Locate the last statement in BODY. See c_end_compound_stmt
7485 about always returning a BIND_EXPR. */
7486 last_p = &BIND_EXPR_BODY (body);
7487 last = BIND_EXPR_BODY (body);
7488
7489 continue_searching:
7490 if (TREE_CODE (last) == STATEMENT_LIST)
7491 {
7492 tree_stmt_iterator i;
7493
7494 /* This can happen with degenerate cases like ({ }). No value. */
7495 if (!TREE_SIDE_EFFECTS (last))
7496 return body;
7497
7498 /* If we're supposed to generate side effects warnings, process
7499 all of the statements except the last. */
7500 if (extra_warnings || warn_unused_value)
7501 {
7502 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7503 emit_side_effect_warnings (tsi_stmt (i));
7504 }
7505 else
7506 i = tsi_last (last);
7507 last_p = tsi_stmt_ptr (i);
7508 last = *last_p;
7509 }
7510
7511 /* If the end of the list is exception related, then the list was split
7512 by a call to push_cleanup. Continue searching. */
7513 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7514 || TREE_CODE (last) == TRY_CATCH_EXPR)
7515 {
7516 last_p = &TREE_OPERAND (last, 0);
7517 last = *last_p;
7518 goto continue_searching;
7519 }
7520
7521 /* In the case that the BIND_EXPR is not necessary, return the
7522 expression out from inside it. */
7523 if (last == error_mark_node
7524 || (last == BIND_EXPR_BODY (body)
7525 && BIND_EXPR_VARS (body) == NULL))
7526 {
7527 /* Do not warn if the return value of a statement expression is
7528 unused. */
7529 if (CAN_HAVE_LOCATION_P (last))
7530 TREE_NO_WARNING (last) = 1;
7531 return last;
7532 }
7533
7534 /* Extract the type of said expression. */
7535 type = TREE_TYPE (last);
7536
7537 /* If we're not returning a value at all, then the BIND_EXPR that
7538 we already have is a fine expression to return. */
7539 if (!type || VOID_TYPE_P (type))
7540 return body;
7541
7542 /* Now that we've located the expression containing the value, it seems
7543 silly to make voidify_wrapper_expr repeat the process. Create a
7544 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7545 tmp = create_tmp_var_raw (type, NULL);
7546
7547 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7548 tree_expr_nonnegative_p giving up immediately. */
7549 val = last;
7550 if (TREE_CODE (val) == NOP_EXPR
7551 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7552 val = TREE_OPERAND (val, 0);
7553
7554 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7555 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7556
7557 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7558 }
7559
7560 /* Begin the scope of an identifier of variably modified type, scope
7561 number SCOPE. Jumping from outside this scope to inside it is not
7562 permitted. */
7563
7564 void
7565 c_begin_vm_scope (unsigned int scope)
7566 {
7567 struct c_label_context_vm *nstack;
7568 struct c_label_list *glist;
7569
7570 gcc_assert (scope > 0);
7571
7572 /* At file_scope, we don't have to do any processing. */
7573 if (label_context_stack_vm == NULL)
7574 return;
7575
7576 if (c_switch_stack && !c_switch_stack->blocked_vm)
7577 c_switch_stack->blocked_vm = scope;
7578 for (glist = label_context_stack_vm->labels_used;
7579 glist != NULL;
7580 glist = glist->next)
7581 {
7582 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7583 }
7584 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7585 nstack->labels_def = NULL;
7586 nstack->labels_used = NULL;
7587 nstack->scope = scope;
7588 nstack->next = label_context_stack_vm;
7589 label_context_stack_vm = nstack;
7590 }
7591
7592 /* End a scope which may contain identifiers of variably modified
7593 type, scope number SCOPE. */
7594
7595 void
7596 c_end_vm_scope (unsigned int scope)
7597 {
7598 if (label_context_stack_vm == NULL)
7599 return;
7600 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7601 c_switch_stack->blocked_vm = 0;
7602 /* We may have a number of nested scopes of identifiers with
7603 variably modified type, all at this depth. Pop each in turn. */
7604 while (label_context_stack_vm->scope == scope)
7605 {
7606 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7607
7608 /* It is no longer possible to jump to labels defined within this
7609 scope. */
7610 for (dlist = label_context_stack_vm->labels_def;
7611 dlist != NULL;
7612 dlist = dlist->next)
7613 {
7614 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7615 }
7616 /* It is again possible to define labels with a goto just outside
7617 this scope. */
7618 for (glist = label_context_stack_vm->next->labels_used;
7619 glist != NULL;
7620 glist = glist->next)
7621 {
7622 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7623 glist_prev = glist;
7624 }
7625 if (glist_prev != NULL)
7626 glist_prev->next = label_context_stack_vm->labels_used;
7627 else
7628 label_context_stack_vm->next->labels_used
7629 = label_context_stack_vm->labels_used;
7630 label_context_stack_vm = label_context_stack_vm->next;
7631 }
7632 }
7633 \f
7634 /* Begin and end compound statements. This is as simple as pushing
7635 and popping new statement lists from the tree. */
7636
7637 tree
7638 c_begin_compound_stmt (bool do_scope)
7639 {
7640 tree stmt = push_stmt_list ();
7641 if (do_scope)
7642 push_scope ();
7643 return stmt;
7644 }
7645
7646 tree
7647 c_end_compound_stmt (tree stmt, bool do_scope)
7648 {
7649 tree block = NULL;
7650
7651 if (do_scope)
7652 {
7653 if (c_dialect_objc ())
7654 objc_clear_super_receiver ();
7655 block = pop_scope ();
7656 }
7657
7658 stmt = pop_stmt_list (stmt);
7659 stmt = c_build_bind_expr (block, stmt);
7660
7661 /* If this compound statement is nested immediately inside a statement
7662 expression, then force a BIND_EXPR to be created. Otherwise we'll
7663 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7664 STATEMENT_LISTs merge, and thus we can lose track of what statement
7665 was really last. */
7666 if (cur_stmt_list
7667 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7668 && TREE_CODE (stmt) != BIND_EXPR)
7669 {
7670 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7671 TREE_SIDE_EFFECTS (stmt) = 1;
7672 }
7673
7674 return stmt;
7675 }
7676
7677 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7678 when the current scope is exited. EH_ONLY is true when this is not
7679 meant to apply to normal control flow transfer. */
7680
7681 void
7682 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7683 {
7684 enum tree_code code;
7685 tree stmt, list;
7686 bool stmt_expr;
7687
7688 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7689 stmt = build_stmt (code, NULL, cleanup);
7690 add_stmt (stmt);
7691 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7692 list = push_stmt_list ();
7693 TREE_OPERAND (stmt, 0) = list;
7694 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7695 }
7696 \f
7697 /* Build a binary-operation expression without default conversions.
7698 CODE is the kind of expression to build.
7699 This function differs from `build' in several ways:
7700 the data type of the result is computed and recorded in it,
7701 warnings are generated if arg data types are invalid,
7702 special handling for addition and subtraction of pointers is known,
7703 and some optimization is done (operations on narrow ints
7704 are done in the narrower type when that gives the same result).
7705 Constant folding is also done before the result is returned.
7706
7707 Note that the operands will never have enumeral types, or function
7708 or array types, because either they will have the default conversions
7709 performed or they have both just been converted to some other type in which
7710 the arithmetic is to be done. */
7711
7712 tree
7713 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7714 int convert_p)
7715 {
7716 tree type0, type1;
7717 enum tree_code code0, code1;
7718 tree op0, op1;
7719 const char *invalid_op_diag;
7720
7721 /* Expression code to give to the expression when it is built.
7722 Normally this is CODE, which is what the caller asked for,
7723 but in some special cases we change it. */
7724 enum tree_code resultcode = code;
7725
7726 /* Data type in which the computation is to be performed.
7727 In the simplest cases this is the common type of the arguments. */
7728 tree result_type = NULL;
7729
7730 /* Nonzero means operands have already been type-converted
7731 in whatever way is necessary.
7732 Zero means they need to be converted to RESULT_TYPE. */
7733 int converted = 0;
7734
7735 /* Nonzero means create the expression with this type, rather than
7736 RESULT_TYPE. */
7737 tree build_type = 0;
7738
7739 /* Nonzero means after finally constructing the expression
7740 convert it to this type. */
7741 tree final_type = 0;
7742
7743 /* Nonzero if this is an operation like MIN or MAX which can
7744 safely be computed in short if both args are promoted shorts.
7745 Also implies COMMON.
7746 -1 indicates a bitwise operation; this makes a difference
7747 in the exact conditions for when it is safe to do the operation
7748 in a narrower mode. */
7749 int shorten = 0;
7750
7751 /* Nonzero if this is a comparison operation;
7752 if both args are promoted shorts, compare the original shorts.
7753 Also implies COMMON. */
7754 int short_compare = 0;
7755
7756 /* Nonzero if this is a right-shift operation, which can be computed on the
7757 original short and then promoted if the operand is a promoted short. */
7758 int short_shift = 0;
7759
7760 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7761 int common = 0;
7762
7763 /* True means types are compatible as far as ObjC is concerned. */
7764 bool objc_ok;
7765
7766 if (convert_p)
7767 {
7768 op0 = default_conversion (orig_op0);
7769 op1 = default_conversion (orig_op1);
7770 }
7771 else
7772 {
7773 op0 = orig_op0;
7774 op1 = orig_op1;
7775 }
7776
7777 type0 = TREE_TYPE (op0);
7778 type1 = TREE_TYPE (op1);
7779
7780 /* The expression codes of the data types of the arguments tell us
7781 whether the arguments are integers, floating, pointers, etc. */
7782 code0 = TREE_CODE (type0);
7783 code1 = TREE_CODE (type1);
7784
7785 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7786 STRIP_TYPE_NOPS (op0);
7787 STRIP_TYPE_NOPS (op1);
7788
7789 /* If an error was already reported for one of the arguments,
7790 avoid reporting another error. */
7791
7792 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7793 return error_mark_node;
7794
7795 if ((invalid_op_diag
7796 = targetm.invalid_binary_op (code, type0, type1)))
7797 {
7798 error (invalid_op_diag);
7799 return error_mark_node;
7800 }
7801
7802 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
7803
7804 switch (code)
7805 {
7806 case PLUS_EXPR:
7807 /* Handle the pointer + int case. */
7808 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7809 return pointer_int_sum (PLUS_EXPR, op0, op1);
7810 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
7811 return pointer_int_sum (PLUS_EXPR, op1, op0);
7812 else
7813 common = 1;
7814 break;
7815
7816 case MINUS_EXPR:
7817 /* Subtraction of two similar pointers.
7818 We must subtract them as integers, then divide by object size. */
7819 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
7820 && comp_target_types (type0, type1))
7821 return pointer_diff (op0, op1);
7822 /* Handle pointer minus int. Just like pointer plus int. */
7823 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7824 return pointer_int_sum (MINUS_EXPR, op0, op1);
7825 else
7826 common = 1;
7827 break;
7828
7829 case MULT_EXPR:
7830 common = 1;
7831 break;
7832
7833 case TRUNC_DIV_EXPR:
7834 case CEIL_DIV_EXPR:
7835 case FLOOR_DIV_EXPR:
7836 case ROUND_DIV_EXPR:
7837 case EXACT_DIV_EXPR:
7838 /* Floating point division by zero is a legitimate way to obtain
7839 infinities and NaNs. */
7840 if (skip_evaluation == 0 && integer_zerop (op1))
7841 warning (OPT_Wdiv_by_zero, "division by zero");
7842
7843 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7844 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7845 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7846 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
7847 {
7848 enum tree_code tcode0 = code0, tcode1 = code1;
7849
7850 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7851 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
7852 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
7853 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
7854
7855 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
7856 resultcode = RDIV_EXPR;
7857 else
7858 /* Although it would be tempting to shorten always here, that
7859 loses on some targets, since the modulo instruction is
7860 undefined if the quotient can't be represented in the
7861 computation mode. We shorten only if unsigned or if
7862 dividing by something we know != -1. */
7863 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7864 || (TREE_CODE (op1) == INTEGER_CST
7865 && !integer_all_onesp (op1)));
7866 common = 1;
7867 }
7868 break;
7869
7870 case BIT_AND_EXPR:
7871 case BIT_IOR_EXPR:
7872 case BIT_XOR_EXPR:
7873 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7874 shorten = -1;
7875 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
7876 common = 1;
7877 break;
7878
7879 case TRUNC_MOD_EXPR:
7880 case FLOOR_MOD_EXPR:
7881 if (skip_evaluation == 0 && integer_zerop (op1))
7882 warning (OPT_Wdiv_by_zero, "division by zero");
7883
7884 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7885 {
7886 /* Although it would be tempting to shorten always here, that loses
7887 on some targets, since the modulo instruction is undefined if the
7888 quotient can't be represented in the computation mode. We shorten
7889 only if unsigned or if dividing by something we know != -1. */
7890 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7891 || (TREE_CODE (op1) == INTEGER_CST
7892 && !integer_all_onesp (op1)));
7893 common = 1;
7894 }
7895 break;
7896
7897 case TRUTH_ANDIF_EXPR:
7898 case TRUTH_ORIF_EXPR:
7899 case TRUTH_AND_EXPR:
7900 case TRUTH_OR_EXPR:
7901 case TRUTH_XOR_EXPR:
7902 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
7903 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
7904 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
7905 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
7906 {
7907 /* Result of these operations is always an int,
7908 but that does not mean the operands should be
7909 converted to ints! */
7910 result_type = integer_type_node;
7911 op0 = c_common_truthvalue_conversion (op0);
7912 op1 = c_common_truthvalue_conversion (op1);
7913 converted = 1;
7914 }
7915 break;
7916
7917 /* Shift operations: result has same type as first operand;
7918 always convert second operand to int.
7919 Also set SHORT_SHIFT if shifting rightward. */
7920
7921 case RSHIFT_EXPR:
7922 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7923 {
7924 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7925 {
7926 if (tree_int_cst_sgn (op1) < 0)
7927 warning (0, "right shift count is negative");
7928 else
7929 {
7930 if (!integer_zerop (op1))
7931 short_shift = 1;
7932
7933 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7934 warning (0, "right shift count >= width of type");
7935 }
7936 }
7937
7938 /* Use the type of the value to be shifted. */
7939 result_type = type0;
7940 /* Convert the shift-count to an integer, regardless of size
7941 of value being shifted. */
7942 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7943 op1 = convert (integer_type_node, op1);
7944 /* Avoid converting op1 to result_type later. */
7945 converted = 1;
7946 }
7947 break;
7948
7949 case LSHIFT_EXPR:
7950 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7951 {
7952 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7953 {
7954 if (tree_int_cst_sgn (op1) < 0)
7955 warning (0, "left shift count is negative");
7956
7957 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7958 warning (0, "left shift count >= width of type");
7959 }
7960
7961 /* Use the type of the value to be shifted. */
7962 result_type = type0;
7963 /* Convert the shift-count to an integer, regardless of size
7964 of value being shifted. */
7965 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7966 op1 = convert (integer_type_node, op1);
7967 /* Avoid converting op1 to result_type later. */
7968 converted = 1;
7969 }
7970 break;
7971
7972 case EQ_EXPR:
7973 case NE_EXPR:
7974 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
7975 warning (OPT_Wfloat_equal,
7976 "comparing floating point with == or != is unsafe");
7977 /* Result of comparison is always int,
7978 but don't convert the args to int! */
7979 build_type = integer_type_node;
7980 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7981 || code0 == COMPLEX_TYPE)
7982 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7983 || code1 == COMPLEX_TYPE))
7984 short_compare = 1;
7985 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
7986 {
7987 tree tt0 = TREE_TYPE (type0);
7988 tree tt1 = TREE_TYPE (type1);
7989 /* Anything compares with void *. void * compares with anything.
7990 Otherwise, the targets must be compatible
7991 and both must be object or both incomplete. */
7992 if (comp_target_types (type0, type1))
7993 result_type = common_pointer_type (type0, type1);
7994 else if (VOID_TYPE_P (tt0))
7995 {
7996 /* op0 != orig_op0 detects the case of something
7997 whose value is 0 but which isn't a valid null ptr const. */
7998 if (pedantic && !null_pointer_constant_p (orig_op0)
7999 && TREE_CODE (tt1) == FUNCTION_TYPE)
8000 pedwarn ("ISO C forbids comparison of %<void *%>"
8001 " with function pointer");
8002 }
8003 else if (VOID_TYPE_P (tt1))
8004 {
8005 if (pedantic && !null_pointer_constant_p (orig_op1)
8006 && TREE_CODE (tt0) == FUNCTION_TYPE)
8007 pedwarn ("ISO C forbids comparison of %<void *%>"
8008 " with function pointer");
8009 }
8010 else
8011 /* Avoid warning about the volatile ObjC EH puts on decls. */
8012 if (!objc_ok)
8013 pedwarn ("comparison of distinct pointer types lacks a cast");
8014
8015 if (result_type == NULL_TREE)
8016 result_type = ptr_type_node;
8017 }
8018 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8019 {
8020 if (TREE_CODE (op0) == ADDR_EXPR
8021 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
8022 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8023 TREE_OPERAND (op0, 0));
8024 result_type = type0;
8025 }
8026 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8027 {
8028 if (TREE_CODE (op1) == ADDR_EXPR
8029 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
8030 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8031 TREE_OPERAND (op1, 0));
8032 result_type = type1;
8033 }
8034 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8035 {
8036 result_type = type0;
8037 pedwarn ("comparison between pointer and integer");
8038 }
8039 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8040 {
8041 result_type = type1;
8042 pedwarn ("comparison between pointer and integer");
8043 }
8044 break;
8045
8046 case LE_EXPR:
8047 case GE_EXPR:
8048 case LT_EXPR:
8049 case GT_EXPR:
8050 build_type = integer_type_node;
8051 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
8052 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
8053 short_compare = 1;
8054 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8055 {
8056 if (comp_target_types (type0, type1))
8057 {
8058 result_type = common_pointer_type (type0, type1);
8059 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8060 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8061 pedwarn ("comparison of complete and incomplete pointers");
8062 else if (pedantic
8063 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8064 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
8065 }
8066 else
8067 {
8068 result_type = ptr_type_node;
8069 pedwarn ("comparison of distinct pointer types lacks a cast");
8070 }
8071 }
8072 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8073 {
8074 result_type = type0;
8075 if (pedantic || extra_warnings)
8076 pedwarn ("ordered comparison of pointer with integer zero");
8077 }
8078 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8079 {
8080 result_type = type1;
8081 if (pedantic)
8082 pedwarn ("ordered comparison of pointer with integer zero");
8083 }
8084 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8085 {
8086 result_type = type0;
8087 pedwarn ("comparison between pointer and integer");
8088 }
8089 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8090 {
8091 result_type = type1;
8092 pedwarn ("comparison between pointer and integer");
8093 }
8094 break;
8095
8096 default:
8097 gcc_unreachable ();
8098 }
8099
8100 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8101 return error_mark_node;
8102
8103 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8104 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8105 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8106 TREE_TYPE (type1))))
8107 {
8108 binary_op_error (code);
8109 return error_mark_node;
8110 }
8111
8112 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8113 || code0 == VECTOR_TYPE)
8114 &&
8115 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8116 || code1 == VECTOR_TYPE))
8117 {
8118 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8119
8120 if (shorten || common || short_compare)
8121 result_type = c_common_type (type0, type1);
8122
8123 /* For certain operations (which identify themselves by shorten != 0)
8124 if both args were extended from the same smaller type,
8125 do the arithmetic in that type and then extend.
8126
8127 shorten !=0 and !=1 indicates a bitwise operation.
8128 For them, this optimization is safe only if
8129 both args are zero-extended or both are sign-extended.
8130 Otherwise, we might change the result.
8131 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8132 but calculated in (unsigned short) it would be (unsigned short)-1. */
8133
8134 if (shorten && none_complex)
8135 {
8136 int unsigned0, unsigned1;
8137 tree arg0, arg1;
8138 int uns;
8139 tree type;
8140
8141 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8142 excessive narrowing when we call get_narrower below. For
8143 example, suppose that OP0 is of unsigned int extended
8144 from signed char and that RESULT_TYPE is long long int.
8145 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8146 like
8147
8148 (long long int) (unsigned int) signed_char
8149
8150 which get_narrower would narrow down to
8151
8152 (unsigned int) signed char
8153
8154 If we do not cast OP0 first, get_narrower would return
8155 signed_char, which is inconsistent with the case of the
8156 explicit cast. */
8157 op0 = convert (result_type, op0);
8158 op1 = convert (result_type, op1);
8159
8160 arg0 = get_narrower (op0, &unsigned0);
8161 arg1 = get_narrower (op1, &unsigned1);
8162
8163 /* UNS is 1 if the operation to be done is an unsigned one. */
8164 uns = TYPE_UNSIGNED (result_type);
8165
8166 final_type = result_type;
8167
8168 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8169 but it *requires* conversion to FINAL_TYPE. */
8170
8171 if ((TYPE_PRECISION (TREE_TYPE (op0))
8172 == TYPE_PRECISION (TREE_TYPE (arg0)))
8173 && TREE_TYPE (op0) != final_type)
8174 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
8175 if ((TYPE_PRECISION (TREE_TYPE (op1))
8176 == TYPE_PRECISION (TREE_TYPE (arg1)))
8177 && TREE_TYPE (op1) != final_type)
8178 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
8179
8180 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8181
8182 /* For bitwise operations, signedness of nominal type
8183 does not matter. Consider only how operands were extended. */
8184 if (shorten == -1)
8185 uns = unsigned0;
8186
8187 /* Note that in all three cases below we refrain from optimizing
8188 an unsigned operation on sign-extended args.
8189 That would not be valid. */
8190
8191 /* Both args variable: if both extended in same way
8192 from same width, do it in that width.
8193 Do it unsigned if args were zero-extended. */
8194 if ((TYPE_PRECISION (TREE_TYPE (arg0))
8195 < TYPE_PRECISION (result_type))
8196 && (TYPE_PRECISION (TREE_TYPE (arg1))
8197 == TYPE_PRECISION (TREE_TYPE (arg0)))
8198 && unsigned0 == unsigned1
8199 && (unsigned0 || !uns))
8200 result_type
8201 = c_common_signed_or_unsigned_type
8202 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
8203 else if (TREE_CODE (arg0) == INTEGER_CST
8204 && (unsigned1 || !uns)
8205 && (TYPE_PRECISION (TREE_TYPE (arg1))
8206 < TYPE_PRECISION (result_type))
8207 && (type
8208 = c_common_signed_or_unsigned_type (unsigned1,
8209 TREE_TYPE (arg1)),
8210 int_fits_type_p (arg0, type)))
8211 result_type = type;
8212 else if (TREE_CODE (arg1) == INTEGER_CST
8213 && (unsigned0 || !uns)
8214 && (TYPE_PRECISION (TREE_TYPE (arg0))
8215 < TYPE_PRECISION (result_type))
8216 && (type
8217 = c_common_signed_or_unsigned_type (unsigned0,
8218 TREE_TYPE (arg0)),
8219 int_fits_type_p (arg1, type)))
8220 result_type = type;
8221 }
8222
8223 /* Shifts can be shortened if shifting right. */
8224
8225 if (short_shift)
8226 {
8227 int unsigned_arg;
8228 tree arg0 = get_narrower (op0, &unsigned_arg);
8229
8230 final_type = result_type;
8231
8232 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8233 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8234
8235 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8236 /* We can shorten only if the shift count is less than the
8237 number of bits in the smaller type size. */
8238 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8239 /* We cannot drop an unsigned shift after sign-extension. */
8240 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8241 {
8242 /* Do an unsigned shift if the operand was zero-extended. */
8243 result_type
8244 = c_common_signed_or_unsigned_type (unsigned_arg,
8245 TREE_TYPE (arg0));
8246 /* Convert value-to-be-shifted to that type. */
8247 if (TREE_TYPE (op0) != result_type)
8248 op0 = convert (result_type, op0);
8249 converted = 1;
8250 }
8251 }
8252
8253 /* Comparison operations are shortened too but differently.
8254 They identify themselves by setting short_compare = 1. */
8255
8256 if (short_compare)
8257 {
8258 /* Don't write &op0, etc., because that would prevent op0
8259 from being kept in a register.
8260 Instead, make copies of the our local variables and
8261 pass the copies by reference, then copy them back afterward. */
8262 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8263 enum tree_code xresultcode = resultcode;
8264 tree val
8265 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8266
8267 if (val != 0)
8268 return val;
8269
8270 op0 = xop0, op1 = xop1;
8271 converted = 1;
8272 resultcode = xresultcode;
8273
8274 if (warn_sign_compare && skip_evaluation == 0)
8275 {
8276 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8277 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8278 int unsignedp0, unsignedp1;
8279 tree primop0 = get_narrower (op0, &unsignedp0);
8280 tree primop1 = get_narrower (op1, &unsignedp1);
8281
8282 xop0 = orig_op0;
8283 xop1 = orig_op1;
8284 STRIP_TYPE_NOPS (xop0);
8285 STRIP_TYPE_NOPS (xop1);
8286
8287 /* Give warnings for comparisons between signed and unsigned
8288 quantities that may fail.
8289
8290 Do the checking based on the original operand trees, so that
8291 casts will be considered, but default promotions won't be.
8292
8293 Do not warn if the comparison is being done in a signed type,
8294 since the signed type will only be chosen if it can represent
8295 all the values of the unsigned type. */
8296 if (!TYPE_UNSIGNED (result_type))
8297 /* OK */;
8298 /* Do not warn if both operands are the same signedness. */
8299 else if (op0_signed == op1_signed)
8300 /* OK */;
8301 else
8302 {
8303 tree sop, uop;
8304
8305 if (op0_signed)
8306 sop = xop0, uop = xop1;
8307 else
8308 sop = xop1, uop = xop0;
8309
8310 /* Do not warn if the signed quantity is an
8311 unsuffixed integer literal (or some static
8312 constant expression involving such literals or a
8313 conditional expression involving such literals)
8314 and it is non-negative. */
8315 if (tree_expr_nonnegative_p (sop))
8316 /* OK */;
8317 /* Do not warn if the comparison is an equality operation,
8318 the unsigned quantity is an integral constant, and it
8319 would fit in the result if the result were signed. */
8320 else if (TREE_CODE (uop) == INTEGER_CST
8321 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8322 && int_fits_type_p
8323 (uop, c_common_signed_type (result_type)))
8324 /* OK */;
8325 /* Do not warn if the unsigned quantity is an enumeration
8326 constant and its maximum value would fit in the result
8327 if the result were signed. */
8328 else if (TREE_CODE (uop) == INTEGER_CST
8329 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8330 && int_fits_type_p
8331 (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8332 c_common_signed_type (result_type)))
8333 /* OK */;
8334 else
8335 warning (0, "comparison between signed and unsigned");
8336 }
8337
8338 /* Warn if two unsigned values are being compared in a size
8339 larger than their original size, and one (and only one) is the
8340 result of a `~' operator. This comparison will always fail.
8341
8342 Also warn if one operand is a constant, and the constant
8343 does not have all bits set that are set in the ~ operand
8344 when it is extended. */
8345
8346 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
8347 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
8348 {
8349 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
8350 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
8351 &unsignedp0);
8352 else
8353 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
8354 &unsignedp1);
8355
8356 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
8357 {
8358 tree primop;
8359 HOST_WIDE_INT constant, mask;
8360 int unsignedp, bits;
8361
8362 if (host_integerp (primop0, 0))
8363 {
8364 primop = primop1;
8365 unsignedp = unsignedp1;
8366 constant = tree_low_cst (primop0, 0);
8367 }
8368 else
8369 {
8370 primop = primop0;
8371 unsignedp = unsignedp0;
8372 constant = tree_low_cst (primop1, 0);
8373 }
8374
8375 bits = TYPE_PRECISION (TREE_TYPE (primop));
8376 if (bits < TYPE_PRECISION (result_type)
8377 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
8378 {
8379 mask = (~(HOST_WIDE_INT) 0) << bits;
8380 if ((mask & constant) != mask)
8381 warning (0, "comparison of promoted ~unsigned with constant");
8382 }
8383 }
8384 else if (unsignedp0 && unsignedp1
8385 && (TYPE_PRECISION (TREE_TYPE (primop0))
8386 < TYPE_PRECISION (result_type))
8387 && (TYPE_PRECISION (TREE_TYPE (primop1))
8388 < TYPE_PRECISION (result_type)))
8389 warning (0, "comparison of promoted ~unsigned with unsigned");
8390 }
8391 }
8392 }
8393 }
8394
8395 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8396 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8397 Then the expression will be built.
8398 It will be given type FINAL_TYPE if that is nonzero;
8399 otherwise, it will be given type RESULT_TYPE. */
8400
8401 if (!result_type)
8402 {
8403 binary_op_error (code);
8404 return error_mark_node;
8405 }
8406
8407 if (!converted)
8408 {
8409 if (TREE_TYPE (op0) != result_type)
8410 op0 = convert_and_check (result_type, op0);
8411 if (TREE_TYPE (op1) != result_type)
8412 op1 = convert_and_check (result_type, op1);
8413
8414 /* This can happen if one operand has a vector type, and the other
8415 has a different type. */
8416 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8417 return error_mark_node;
8418 }
8419
8420 if (build_type == NULL_TREE)
8421 build_type = result_type;
8422
8423 {
8424 /* Treat expressions in initializers specially as they can't trap. */
8425 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8426 build_type,
8427 op0, op1)
8428 : fold_build2 (resultcode, build_type,
8429 op0, op1);
8430
8431 if (final_type != 0)
8432 result = convert (final_type, result);
8433 return result;
8434 }
8435 }
8436
8437
8438 /* Convert EXPR to be a truth-value, validating its type for this
8439 purpose. */
8440
8441 tree
8442 c_objc_common_truthvalue_conversion (tree expr)
8443 {
8444 switch (TREE_CODE (TREE_TYPE (expr)))
8445 {
8446 case ARRAY_TYPE:
8447 error ("used array that cannot be converted to pointer where scalar is required");
8448 return error_mark_node;
8449
8450 case RECORD_TYPE:
8451 error ("used struct type value where scalar is required");
8452 return error_mark_node;
8453
8454 case UNION_TYPE:
8455 error ("used union type value where scalar is required");
8456 return error_mark_node;
8457
8458 case FUNCTION_TYPE:
8459 gcc_unreachable ();
8460
8461 default:
8462 break;
8463 }
8464
8465 /* ??? Should we also give an error for void and vectors rather than
8466 leaving those to give errors later? */
8467 return c_common_truthvalue_conversion (expr);
8468 }
8469 \f
8470
8471 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8472 required. */
8473
8474 tree
8475 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
8476 bool *ti ATTRIBUTE_UNUSED, bool *se)
8477 {
8478 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8479 {
8480 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8481 /* Executing a compound literal inside a function reinitializes
8482 it. */
8483 if (!TREE_STATIC (decl))
8484 *se = true;
8485 return decl;
8486 }
8487 else
8488 return expr;
8489 }
8490 \f
8491 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8492
8493 tree
8494 c_begin_omp_parallel (void)
8495 {
8496 tree block;
8497
8498 keep_next_level ();
8499 block = c_begin_compound_stmt (true);
8500
8501 return block;
8502 }
8503
8504 tree
8505 c_finish_omp_parallel (tree clauses, tree block)
8506 {
8507 tree stmt;
8508
8509 block = c_end_compound_stmt (block, true);
8510
8511 stmt = make_node (OMP_PARALLEL);
8512 TREE_TYPE (stmt) = void_type_node;
8513 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8514 OMP_PARALLEL_BODY (stmt) = block;
8515
8516 return add_stmt (stmt);
8517 }
8518
8519 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8520 Remove any elements from the list that are invalid. */
8521
8522 tree
8523 c_finish_omp_clauses (tree clauses)
8524 {
8525 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8526 tree c, t, *pc = &clauses;
8527 const char *name;
8528
8529 bitmap_obstack_initialize (NULL);
8530 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8531 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8532 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8533
8534 for (pc = &clauses, c = clauses; c ; c = *pc)
8535 {
8536 bool remove = false;
8537 bool need_complete = false;
8538 bool need_implicitly_determined = false;
8539
8540 switch (OMP_CLAUSE_CODE (c))
8541 {
8542 case OMP_CLAUSE_SHARED:
8543 name = "shared";
8544 need_implicitly_determined = true;
8545 goto check_dup_generic;
8546
8547 case OMP_CLAUSE_PRIVATE:
8548 name = "private";
8549 need_complete = true;
8550 need_implicitly_determined = true;
8551 goto check_dup_generic;
8552
8553 case OMP_CLAUSE_REDUCTION:
8554 name = "reduction";
8555 need_implicitly_determined = true;
8556 t = OMP_CLAUSE_DECL (c);
8557 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8558 || POINTER_TYPE_P (TREE_TYPE (t)))
8559 {
8560 error ("%qE has invalid type for %<reduction%>", t);
8561 remove = true;
8562 }
8563 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8564 {
8565 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8566 const char *r_name = NULL;
8567
8568 switch (r_code)
8569 {
8570 case PLUS_EXPR:
8571 case MULT_EXPR:
8572 case MINUS_EXPR:
8573 break;
8574 case BIT_AND_EXPR:
8575 r_name = "&";
8576 break;
8577 case BIT_XOR_EXPR:
8578 r_name = "^";
8579 break;
8580 case BIT_IOR_EXPR:
8581 r_name = "|";
8582 break;
8583 case TRUTH_ANDIF_EXPR:
8584 r_name = "&&";
8585 break;
8586 case TRUTH_ORIF_EXPR:
8587 r_name = "||";
8588 break;
8589 default:
8590 gcc_unreachable ();
8591 }
8592 if (r_name)
8593 {
8594 error ("%qE has invalid type for %<reduction(%s)%>",
8595 t, r_name);
8596 remove = true;
8597 }
8598 }
8599 goto check_dup_generic;
8600
8601 case OMP_CLAUSE_COPYPRIVATE:
8602 name = "copyprivate";
8603 goto check_dup_generic;
8604
8605 case OMP_CLAUSE_COPYIN:
8606 name = "copyin";
8607 t = OMP_CLAUSE_DECL (c);
8608 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8609 {
8610 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8611 remove = true;
8612 }
8613 goto check_dup_generic;
8614
8615 check_dup_generic:
8616 t = OMP_CLAUSE_DECL (c);
8617 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8618 {
8619 error ("%qE is not a variable in clause %qs", t, name);
8620 remove = true;
8621 }
8622 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8623 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8624 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8625 {
8626 error ("%qE appears more than once in data clauses", t);
8627 remove = true;
8628 }
8629 else
8630 bitmap_set_bit (&generic_head, DECL_UID (t));
8631 break;
8632
8633 case OMP_CLAUSE_FIRSTPRIVATE:
8634 name = "firstprivate";
8635 t = OMP_CLAUSE_DECL (c);
8636 need_complete = true;
8637 need_implicitly_determined = true;
8638 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8639 {
8640 error ("%qE is not a variable in clause %<firstprivate%>", t);
8641 remove = true;
8642 }
8643 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8644 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8645 {
8646 error ("%qE appears more than once in data clauses", t);
8647 remove = true;
8648 }
8649 else
8650 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8651 break;
8652
8653 case OMP_CLAUSE_LASTPRIVATE:
8654 name = "lastprivate";
8655 t = OMP_CLAUSE_DECL (c);
8656 need_complete = true;
8657 need_implicitly_determined = true;
8658 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8659 {
8660 error ("%qE is not a variable in clause %<lastprivate%>", t);
8661 remove = true;
8662 }
8663 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8664 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8665 {
8666 error ("%qE appears more than once in data clauses", t);
8667 remove = true;
8668 }
8669 else
8670 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8671 break;
8672
8673 case OMP_CLAUSE_IF:
8674 case OMP_CLAUSE_NUM_THREADS:
8675 case OMP_CLAUSE_SCHEDULE:
8676 case OMP_CLAUSE_NOWAIT:
8677 case OMP_CLAUSE_ORDERED:
8678 case OMP_CLAUSE_DEFAULT:
8679 pc = &OMP_CLAUSE_CHAIN (c);
8680 continue;
8681
8682 default:
8683 gcc_unreachable ();
8684 }
8685
8686 if (!remove)
8687 {
8688 t = OMP_CLAUSE_DECL (c);
8689
8690 if (need_complete)
8691 {
8692 t = require_complete_type (t);
8693 if (t == error_mark_node)
8694 remove = true;
8695 }
8696
8697 if (need_implicitly_determined)
8698 {
8699 const char *share_name = NULL;
8700
8701 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8702 share_name = "threadprivate";
8703 else switch (c_omp_predetermined_sharing (t))
8704 {
8705 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8706 break;
8707 case OMP_CLAUSE_DEFAULT_SHARED:
8708 share_name = "shared";
8709 break;
8710 case OMP_CLAUSE_DEFAULT_PRIVATE:
8711 share_name = "private";
8712 break;
8713 default:
8714 gcc_unreachable ();
8715 }
8716 if (share_name)
8717 {
8718 error ("%qE is predetermined %qs for %qs",
8719 t, share_name, name);
8720 remove = true;
8721 }
8722 }
8723 }
8724
8725 if (remove)
8726 *pc = OMP_CLAUSE_CHAIN (c);
8727 else
8728 pc = &OMP_CLAUSE_CHAIN (c);
8729 }
8730
8731 bitmap_obstack_release (NULL);
8732 return clauses;
8733 }
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