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PR c++/29733
[official-gcc.git] / gcc / c-typeck.c
blob2534c25e75dd80513a2aaf9d580cdf71076e6fcd
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
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_CONSTANT_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
2113 return ref;
2114 }
2115
2116 /* Record details of decls possibly used inside sizeof or typeof. */
2117 struct maybe_used_decl
2118 {
2119 /* The decl. */
2120 tree decl;
2121 /* The level seen at (in_sizeof + in_typeof). */
2122 int level;
2123 /* The next one at this level or above, or NULL. */
2124 struct maybe_used_decl *next;
2125 };
2126
2127 static struct maybe_used_decl *maybe_used_decls;
2128
2129 /* Record that DECL, an undefined static function reference seen
2130 inside sizeof or typeof, might be used if the operand of sizeof is
2131 a VLA type or the operand of typeof is a variably modified
2132 type. */
2133
2134 static void
2135 record_maybe_used_decl (tree decl)
2136 {
2137 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2138 t->decl = decl;
2139 t->level = in_sizeof + in_typeof;
2140 t->next = maybe_used_decls;
2141 maybe_used_decls = t;
2142 }
2143
2144 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2145 USED is false, just discard them. If it is true, mark them used
2146 (if no longer inside sizeof or typeof) or move them to the next
2147 level up (if still inside sizeof or typeof). */
2148
2149 void
2150 pop_maybe_used (bool used)
2151 {
2152 struct maybe_used_decl *p = maybe_used_decls;
2153 int cur_level = in_sizeof + in_typeof;
2154 while (p && p->level > cur_level)
2155 {
2156 if (used)
2157 {
2158 if (cur_level == 0)
2159 C_DECL_USED (p->decl) = 1;
2160 else
2161 p->level = cur_level;
2162 }
2163 p = p->next;
2164 }
2165 if (!used || cur_level == 0)
2166 maybe_used_decls = p;
2167 }
2168
2169 /* Return the result of sizeof applied to EXPR. */
2170
2171 struct c_expr
2172 c_expr_sizeof_expr (struct c_expr expr)
2173 {
2174 struct c_expr ret;
2175 if (expr.value == error_mark_node)
2176 {
2177 ret.value = error_mark_node;
2178 ret.original_code = ERROR_MARK;
2179 pop_maybe_used (false);
2180 }
2181 else
2182 {
2183 ret.value = c_sizeof (TREE_TYPE (expr.value));
2184 ret.original_code = ERROR_MARK;
2185 if (c_vla_type_p (TREE_TYPE (expr.value)))
2186 {
2187 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2188 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2189 }
2190 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2191 }
2192 return ret;
2193 }
2194
2195 /* Return the result of sizeof applied to T, a structure for the type
2196 name passed to sizeof (rather than the type itself). */
2197
2198 struct c_expr
2199 c_expr_sizeof_type (struct c_type_name *t)
2200 {
2201 tree type;
2202 struct c_expr ret;
2203 type = groktypename (t);
2204 ret.value = c_sizeof (type);
2205 ret.original_code = ERROR_MARK;
2206 pop_maybe_used (type != error_mark_node
2207 ? C_TYPE_VARIABLE_SIZE (type) : false);
2208 return ret;
2209 }
2210
2211 /* Build a function call to function FUNCTION with parameters PARAMS.
2212 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2213 TREE_VALUE of each node is a parameter-expression.
2214 FUNCTION's data type may be a function type or a pointer-to-function. */
2215
2216 tree
2217 build_function_call (tree function, tree params)
2218 {
2219 tree fntype, fundecl = 0;
2220 tree coerced_params;
2221 tree name = NULL_TREE, result;
2222 tree tem;
2223
2224 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2225 STRIP_TYPE_NOPS (function);
2226
2227 /* Convert anything with function type to a pointer-to-function. */
2228 if (TREE_CODE (function) == FUNCTION_DECL)
2229 {
2230 /* Implement type-directed function overloading for builtins.
2231 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2232 handle all the type checking. The result is a complete expression
2233 that implements this function call. */
2234 tem = resolve_overloaded_builtin (function, params);
2235 if (tem)
2236 return tem;
2237
2238 name = DECL_NAME (function);
2239 fundecl = function;
2240 }
2241 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2242 function = function_to_pointer_conversion (function);
2243
2244 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2245 expressions, like those used for ObjC messenger dispatches. */
2246 function = objc_rewrite_function_call (function, params);
2247
2248 fntype = TREE_TYPE (function);
2249
2250 if (TREE_CODE (fntype) == ERROR_MARK)
2251 return error_mark_node;
2252
2253 if (!(TREE_CODE (fntype) == POINTER_TYPE
2254 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2255 {
2256 error ("called object %qE is not a function", function);
2257 return error_mark_node;
2258 }
2259
2260 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2261 current_function_returns_abnormally = 1;
2262
2263 /* fntype now gets the type of function pointed to. */
2264 fntype = TREE_TYPE (fntype);
2265
2266 /* Check that the function is called through a compatible prototype.
2267 If it is not, replace the call by a trap, wrapped up in a compound
2268 expression if necessary. This has the nice side-effect to prevent
2269 the tree-inliner from generating invalid assignment trees which may
2270 blow up in the RTL expander later. */
2271 if ((TREE_CODE (function) == NOP_EXPR
2272 || TREE_CODE (function) == CONVERT_EXPR)
2273 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2274 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2275 && !comptypes (fntype, TREE_TYPE (tem)))
2276 {
2277 tree return_type = TREE_TYPE (fntype);
2278 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2279 NULL_TREE);
2280
2281 /* This situation leads to run-time undefined behavior. We can't,
2282 therefore, simply error unless we can prove that all possible
2283 executions of the program must execute the code. */
2284 warning (0, "function called through a non-compatible type");
2285
2286 /* We can, however, treat "undefined" any way we please.
2287 Call abort to encourage the user to fix the program. */
2288 inform ("if this code is reached, the program will abort");
2289
2290 if (VOID_TYPE_P (return_type))
2291 return trap;
2292 else
2293 {
2294 tree rhs;
2295
2296 if (AGGREGATE_TYPE_P (return_type))
2297 rhs = build_compound_literal (return_type,
2298 build_constructor (return_type, 0));
2299 else
2300 rhs = fold_convert (return_type, integer_zero_node);
2301
2302 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2303 }
2304 }
2305
2306 /* Convert the parameters to the types declared in the
2307 function prototype, or apply default promotions. */
2308
2309 coerced_params
2310 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl);
2311
2312 if (coerced_params == error_mark_node)
2313 return error_mark_node;
2314
2315 /* Check that the arguments to the function are valid. */
2316
2317 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2318 TYPE_ARG_TYPES (fntype));
2319
2320 if (require_constant_value)
2321 {
2322 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype),
2323 function, coerced_params, NULL_TREE);
2324
2325 if (TREE_CONSTANT (result)
2326 && (name == NULL_TREE
2327 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2328 pedwarn_init ("initializer element is not constant");
2329 }
2330 else
2331 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype),
2332 function, coerced_params, NULL_TREE);
2333
2334 if (VOID_TYPE_P (TREE_TYPE (result)))
2335 return result;
2336 return require_complete_type (result);
2337 }
2338 \f
2339 /* Convert the argument expressions in the list VALUES
2340 to the types in the list TYPELIST. The result is a list of converted
2341 argument expressions, unless there are too few arguments in which
2342 case it is error_mark_node.
2343
2344 If TYPELIST is exhausted, or when an element has NULL as its type,
2345 perform the default conversions.
2346
2347 PARMLIST is the chain of parm decls for the function being called.
2348 It may be 0, if that info is not available.
2349 It is used only for generating error messages.
2350
2351 FUNCTION is a tree for the called function. It is used only for
2352 error messages, where it is formatted with %qE.
2353
2354 This is also where warnings about wrong number of args are generated.
2355
2356 Both VALUES and the returned value are chains of TREE_LIST nodes
2357 with the elements of the list in the TREE_VALUE slots of those nodes. */
2358
2359 static tree
2360 convert_arguments (tree typelist, tree values, tree function, tree fundecl)
2361 {
2362 tree typetail, valtail;
2363 tree result = NULL;
2364 int parmnum;
2365 tree selector;
2366
2367 /* Change pointer to function to the function itself for
2368 diagnostics. */
2369 if (TREE_CODE (function) == ADDR_EXPR
2370 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2371 function = TREE_OPERAND (function, 0);
2372
2373 /* Handle an ObjC selector specially for diagnostics. */
2374 selector = objc_message_selector ();
2375
2376 /* Scan the given expressions and types, producing individual
2377 converted arguments and pushing them on RESULT in reverse order. */
2378
2379 for (valtail = values, typetail = typelist, parmnum = 0;
2380 valtail;
2381 valtail = TREE_CHAIN (valtail), parmnum++)
2382 {
2383 tree type = typetail ? TREE_VALUE (typetail) : 0;
2384 tree val = TREE_VALUE (valtail);
2385 tree rname = function;
2386 int argnum = parmnum + 1;
2387 const char *invalid_func_diag;
2388
2389 if (type == void_type_node)
2390 {
2391 error ("too many arguments to function %qE", function);
2392 break;
2393 }
2394
2395 if (selector && argnum > 2)
2396 {
2397 rname = selector;
2398 argnum -= 2;
2399 }
2400
2401 STRIP_TYPE_NOPS (val);
2402
2403 val = require_complete_type (val);
2404
2405 if (type != 0)
2406 {
2407 /* Formal parm type is specified by a function prototype. */
2408 tree parmval;
2409
2410 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2411 {
2412 error ("type of formal parameter %d is incomplete", parmnum + 1);
2413 parmval = val;
2414 }
2415 else
2416 {
2417 /* Optionally warn about conversions that
2418 differ from the default conversions. */
2419 if (warn_conversion || warn_traditional)
2420 {
2421 unsigned int formal_prec = TYPE_PRECISION (type);
2422
2423 if (INTEGRAL_TYPE_P (type)
2424 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2425 warning (0, "passing argument %d of %qE as integer "
2426 "rather than floating due to prototype",
2427 argnum, rname);
2428 if (INTEGRAL_TYPE_P (type)
2429 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2430 warning (0, "passing argument %d of %qE as integer "
2431 "rather than complex due to prototype",
2432 argnum, rname);
2433 else if (TREE_CODE (type) == COMPLEX_TYPE
2434 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2435 warning (0, "passing argument %d of %qE as complex "
2436 "rather than floating due to prototype",
2437 argnum, rname);
2438 else if (TREE_CODE (type) == REAL_TYPE
2439 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2440 warning (0, "passing argument %d of %qE as floating "
2441 "rather than integer due to prototype",
2442 argnum, rname);
2443 else if (TREE_CODE (type) == COMPLEX_TYPE
2444 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2445 warning (0, "passing argument %d of %qE as complex "
2446 "rather than integer due to prototype",
2447 argnum, rname);
2448 else if (TREE_CODE (type) == REAL_TYPE
2449 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2450 warning (0, "passing argument %d of %qE as floating "
2451 "rather than complex due to prototype",
2452 argnum, rname);
2453 /* ??? At some point, messages should be written about
2454 conversions between complex types, but that's too messy
2455 to do now. */
2456 else if (TREE_CODE (type) == REAL_TYPE
2457 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2458 {
2459 /* Warn if any argument is passed as `float',
2460 since without a prototype it would be `double'. */
2461 if (formal_prec == TYPE_PRECISION (float_type_node)
2462 && type != dfloat32_type_node)
2463 warning (0, "passing argument %d of %qE as %<float%> "
2464 "rather than %<double%> due to prototype",
2465 argnum, rname);
2466
2467 /* Warn if mismatch between argument and prototype
2468 for decimal float types. Warn of conversions with
2469 binary float types and of precision narrowing due to
2470 prototype. */
2471 else if (type != TREE_TYPE (val)
2472 && (type == dfloat32_type_node
2473 || type == dfloat64_type_node
2474 || type == dfloat128_type_node
2475 || TREE_TYPE (val) == dfloat32_type_node
2476 || TREE_TYPE (val) == dfloat64_type_node
2477 || TREE_TYPE (val) == dfloat128_type_node)
2478 && (formal_prec
2479 <= TYPE_PRECISION (TREE_TYPE (val))
2480 || (type == dfloat128_type_node
2481 && (TREE_TYPE (val)
2482 != dfloat64_type_node
2483 && (TREE_TYPE (val)
2484 != dfloat32_type_node)))
2485 || (type == dfloat64_type_node
2486 && (TREE_TYPE (val)
2487 != dfloat32_type_node))))
2488 warning (0, "passing argument %d of %qE as %qT "
2489 "rather than %qT due to prototype",
2490 argnum, rname, type, TREE_TYPE (val));
2491
2492 }
2493 /* Detect integer changing in width or signedness.
2494 These warnings are only activated with
2495 -Wconversion, not with -Wtraditional. */
2496 else if (warn_conversion && INTEGRAL_TYPE_P (type)
2497 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2498 {
2499 tree would_have_been = default_conversion (val);
2500 tree type1 = TREE_TYPE (would_have_been);
2501
2502 if (TREE_CODE (type) == ENUMERAL_TYPE
2503 && (TYPE_MAIN_VARIANT (type)
2504 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2505 /* No warning if function asks for enum
2506 and the actual arg is that enum type. */
2507 ;
2508 else if (formal_prec != TYPE_PRECISION (type1))
2509 warning (OPT_Wconversion, "passing argument %d of %qE "
2510 "with different width due to prototype",
2511 argnum, rname);
2512 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2513 ;
2514 /* Don't complain if the formal parameter type
2515 is an enum, because we can't tell now whether
2516 the value was an enum--even the same enum. */
2517 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2518 ;
2519 else if (TREE_CODE (val) == INTEGER_CST
2520 && int_fits_type_p (val, type))
2521 /* Change in signedness doesn't matter
2522 if a constant value is unaffected. */
2523 ;
2524 /* If the value is extended from a narrower
2525 unsigned type, it doesn't matter whether we
2526 pass it as signed or unsigned; the value
2527 certainly is the same either way. */
2528 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2529 && TYPE_UNSIGNED (TREE_TYPE (val)))
2530 ;
2531 else if (TYPE_UNSIGNED (type))
2532 warning (OPT_Wconversion, "passing argument %d of %qE "
2533 "as unsigned due to prototype",
2534 argnum, rname);
2535 else
2536 warning (OPT_Wconversion, "passing argument %d of %qE "
2537 "as signed due to prototype", argnum, rname);
2538 }
2539 }
2540
2541 parmval = convert_for_assignment (type, val, ic_argpass,
2542 fundecl, function,
2543 parmnum + 1);
2544
2545 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2546 && INTEGRAL_TYPE_P (type)
2547 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2548 parmval = default_conversion (parmval);
2549 }
2550 result = tree_cons (NULL_TREE, parmval, result);
2551 }
2552 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2553 && (TYPE_PRECISION (TREE_TYPE (val))
2554 < TYPE_PRECISION (double_type_node))
2555 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2556 /* Convert `float' to `double'. */
2557 result = tree_cons (NULL_TREE, convert (double_type_node, val), result);
2558 else if ((invalid_func_diag =
2559 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2560 {
2561 error (invalid_func_diag);
2562 return error_mark_node;
2563 }
2564 else
2565 /* Convert `short' and `char' to full-size `int'. */
2566 result = tree_cons (NULL_TREE, default_conversion (val), result);
2567
2568 if (typetail)
2569 typetail = TREE_CHAIN (typetail);
2570 }
2571
2572 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2573 {
2574 error ("too few arguments to function %qE", function);
2575 return error_mark_node;
2576 }
2577
2578 return nreverse (result);
2579 }
2580 \f
2581 /* This is the entry point used by the parser to build unary operators
2582 in the input. CODE, a tree_code, specifies the unary operator, and
2583 ARG is the operand. For unary plus, the C parser currently uses
2584 CONVERT_EXPR for code. */
2585
2586 struct c_expr
2587 parser_build_unary_op (enum tree_code code, struct c_expr arg)
2588 {
2589 struct c_expr result;
2590
2591 result.original_code = ERROR_MARK;
2592 result.value = build_unary_op (code, arg.value, 0);
2593 overflow_warning (result.value);
2594 return result;
2595 }
2596
2597 /* This is the entry point used by the parser to build binary operators
2598 in the input. CODE, a tree_code, specifies the binary operator, and
2599 ARG1 and ARG2 are the operands. In addition to constructing the
2600 expression, we check for operands that were written with other binary
2601 operators in a way that is likely to confuse the user. */
2602
2603 struct c_expr
2604 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2605 struct c_expr arg2)
2606 {
2607 struct c_expr result;
2608
2609 enum tree_code code1 = arg1.original_code;
2610 enum tree_code code2 = arg2.original_code;
2611
2612 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2613 result.original_code = code;
2614
2615 if (TREE_CODE (result.value) == ERROR_MARK)
2616 return result;
2617
2618 /* Check for cases such as x+y<<z which users are likely
2619 to misinterpret. */
2620 if (warn_parentheses)
2621 {
2622 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
2623 {
2624 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
2625 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2626 warning (OPT_Wparentheses,
2627 "suggest parentheses around + or - inside shift");
2628 }
2629
2630 if (code == TRUTH_ORIF_EXPR)
2631 {
2632 if (code1 == TRUTH_ANDIF_EXPR
2633 || code2 == TRUTH_ANDIF_EXPR)
2634 warning (OPT_Wparentheses,
2635 "suggest parentheses around && within ||");
2636 }
2637
2638 if (code == BIT_IOR_EXPR)
2639 {
2640 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR
2641 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
2642 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR
2643 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2644 warning (OPT_Wparentheses,
2645 "suggest parentheses around arithmetic in operand of |");
2646 /* Check cases like x|y==z */
2647 if (TREE_CODE_CLASS (code1) == tcc_comparison
2648 || TREE_CODE_CLASS (code2) == tcc_comparison)
2649 warning (OPT_Wparentheses,
2650 "suggest parentheses around comparison in operand of |");
2651 }
2652
2653 if (code == BIT_XOR_EXPR)
2654 {
2655 if (code1 == BIT_AND_EXPR
2656 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
2657 || code2 == BIT_AND_EXPR
2658 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2659 warning (OPT_Wparentheses,
2660 "suggest parentheses around arithmetic in operand of ^");
2661 /* Check cases like x^y==z */
2662 if (TREE_CODE_CLASS (code1) == tcc_comparison
2663 || TREE_CODE_CLASS (code2) == tcc_comparison)
2664 warning (OPT_Wparentheses,
2665 "suggest parentheses around comparison in operand of ^");
2666 }
2667
2668 if (code == BIT_AND_EXPR)
2669 {
2670 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
2671 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2672 warning (OPT_Wparentheses,
2673 "suggest parentheses around + or - in operand of &");
2674 /* Check cases like x&y==z */
2675 if (TREE_CODE_CLASS (code1) == tcc_comparison
2676 || TREE_CODE_CLASS (code2) == tcc_comparison)
2677 warning (OPT_Wparentheses,
2678 "suggest parentheses around comparison in operand of &");
2679 }
2680 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2681 if (TREE_CODE_CLASS (code) == tcc_comparison
2682 && (TREE_CODE_CLASS (code1) == tcc_comparison
2683 || TREE_CODE_CLASS (code2) == tcc_comparison))
2684 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
2685 "have their mathematical meaning");
2686
2687 }
2688
2689 /* Warn about comparisons against string literals, with the exception
2690 of testing for equality or inequality of a string literal with NULL. */
2691 if (code == EQ_EXPR || code == NE_EXPR)
2692 {
2693 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2694 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2695 warning (OPT_Wstring_literal_comparison,
2696 "comparison with string literal");
2697 }
2698 else if (TREE_CODE_CLASS (code) == tcc_comparison
2699 && (code1 == STRING_CST || code2 == STRING_CST))
2700 warning (OPT_Wstring_literal_comparison,
2701 "comparison with string literal");
2702
2703 overflow_warning (result.value);
2704
2705 return result;
2706 }
2707 \f
2708 /* Return a tree for the difference of pointers OP0 and OP1.
2709 The resulting tree has type int. */
2710
2711 static tree
2712 pointer_diff (tree op0, tree op1)
2713 {
2714 tree restype = ptrdiff_type_node;
2715
2716 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2717 tree con0, con1, lit0, lit1;
2718 tree orig_op1 = op1;
2719
2720 if (pedantic || warn_pointer_arith)
2721 {
2722 if (TREE_CODE (target_type) == VOID_TYPE)
2723 pedwarn ("pointer of type %<void *%> used in subtraction");
2724 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2725 pedwarn ("pointer to a function used in subtraction");
2726 }
2727
2728 /* If the conversion to ptrdiff_type does anything like widening or
2729 converting a partial to an integral mode, we get a convert_expression
2730 that is in the way to do any simplifications.
2731 (fold-const.c doesn't know that the extra bits won't be needed.
2732 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2733 different mode in place.)
2734 So first try to find a common term here 'by hand'; we want to cover
2735 at least the cases that occur in legal static initializers. */
2736 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR)
2737 && (TYPE_PRECISION (TREE_TYPE (op0))
2738 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2739 con0 = TREE_OPERAND (op0, 0);
2740 else
2741 con0 = op0;
2742 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR)
2743 && (TYPE_PRECISION (TREE_TYPE (op1))
2744 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2745 con1 = TREE_OPERAND (op1, 0);
2746 else
2747 con1 = op1;
2748
2749 if (TREE_CODE (con0) == PLUS_EXPR)
2750 {
2751 lit0 = TREE_OPERAND (con0, 1);
2752 con0 = TREE_OPERAND (con0, 0);
2753 }
2754 else
2755 lit0 = integer_zero_node;
2756
2757 if (TREE_CODE (con1) == PLUS_EXPR)
2758 {
2759 lit1 = TREE_OPERAND (con1, 1);
2760 con1 = TREE_OPERAND (con1, 0);
2761 }
2762 else
2763 lit1 = integer_zero_node;
2764
2765 if (operand_equal_p (con0, con1, 0))
2766 {
2767 op0 = lit0;
2768 op1 = lit1;
2769 }
2770
2771
2772 /* First do the subtraction as integers;
2773 then drop through to build the divide operator.
2774 Do not do default conversions on the minus operator
2775 in case restype is a short type. */
2776
2777 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2778 convert (restype, op1), 0);
2779 /* This generates an error if op1 is pointer to incomplete type. */
2780 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2781 error ("arithmetic on pointer to an incomplete type");
2782
2783 /* This generates an error if op0 is pointer to incomplete type. */
2784 op1 = c_size_in_bytes (target_type);
2785
2786 /* Divide by the size, in easiest possible way. */
2787 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2788 }
2789 \f
2790 /* Construct and perhaps optimize a tree representation
2791 for a unary operation. CODE, a tree_code, specifies the operation
2792 and XARG is the operand.
2793 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2794 the default promotions (such as from short to int).
2795 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2796 allows non-lvalues; this is only used to handle conversion of non-lvalue
2797 arrays to pointers in C99. */
2798
2799 tree
2800 build_unary_op (enum tree_code code, tree xarg, int flag)
2801 {
2802 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2803 tree arg = xarg;
2804 tree argtype = 0;
2805 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2806 tree val;
2807 int noconvert = flag;
2808 const char *invalid_op_diag;
2809
2810 if (typecode == ERROR_MARK)
2811 return error_mark_node;
2812 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2813 typecode = INTEGER_TYPE;
2814
2815 if ((invalid_op_diag
2816 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2817 {
2818 error (invalid_op_diag);
2819 return error_mark_node;
2820 }
2821
2822 switch (code)
2823 {
2824 case CONVERT_EXPR:
2825 /* This is used for unary plus, because a CONVERT_EXPR
2826 is enough to prevent anybody from looking inside for
2827 associativity, but won't generate any code. */
2828 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2829 || typecode == COMPLEX_TYPE
2830 || typecode == VECTOR_TYPE))
2831 {
2832 error ("wrong type argument to unary plus");
2833 return error_mark_node;
2834 }
2835 else if (!noconvert)
2836 arg = default_conversion (arg);
2837 arg = non_lvalue (arg);
2838 break;
2839
2840 case NEGATE_EXPR:
2841 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2842 || typecode == COMPLEX_TYPE
2843 || typecode == VECTOR_TYPE))
2844 {
2845 error ("wrong type argument to unary minus");
2846 return error_mark_node;
2847 }
2848 else if (!noconvert)
2849 arg = default_conversion (arg);
2850 break;
2851
2852 case BIT_NOT_EXPR:
2853 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE)
2854 {
2855 if (!noconvert)
2856 arg = default_conversion (arg);
2857 }
2858 else if (typecode == COMPLEX_TYPE)
2859 {
2860 code = CONJ_EXPR;
2861 if (pedantic)
2862 pedwarn ("ISO C does not support %<~%> for complex conjugation");
2863 if (!noconvert)
2864 arg = default_conversion (arg);
2865 }
2866 else
2867 {
2868 error ("wrong type argument to bit-complement");
2869 return error_mark_node;
2870 }
2871 break;
2872
2873 case ABS_EXPR:
2874 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2875 {
2876 error ("wrong type argument to abs");
2877 return error_mark_node;
2878 }
2879 else if (!noconvert)
2880 arg = default_conversion (arg);
2881 break;
2882
2883 case CONJ_EXPR:
2884 /* Conjugating a real value is a no-op, but allow it anyway. */
2885 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2886 || typecode == COMPLEX_TYPE))
2887 {
2888 error ("wrong type argument to conjugation");
2889 return error_mark_node;
2890 }
2891 else if (!noconvert)
2892 arg = default_conversion (arg);
2893 break;
2894
2895 case TRUTH_NOT_EXPR:
2896 if (typecode != INTEGER_TYPE
2897 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2898 && typecode != COMPLEX_TYPE)
2899 {
2900 error ("wrong type argument to unary exclamation mark");
2901 return error_mark_node;
2902 }
2903 arg = c_objc_common_truthvalue_conversion (arg);
2904 return invert_truthvalue (arg);
2905
2906 case REALPART_EXPR:
2907 if (TREE_CODE (arg) == COMPLEX_CST)
2908 return TREE_REALPART (arg);
2909 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2910 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2911 else
2912 return arg;
2913
2914 case IMAGPART_EXPR:
2915 if (TREE_CODE (arg) == COMPLEX_CST)
2916 return TREE_IMAGPART (arg);
2917 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2918 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2919 else
2920 return convert (TREE_TYPE (arg), integer_zero_node);
2921
2922 case PREINCREMENT_EXPR:
2923 case POSTINCREMENT_EXPR:
2924 case PREDECREMENT_EXPR:
2925 case POSTDECREMENT_EXPR:
2926
2927 /* Increment or decrement the real part of the value,
2928 and don't change the imaginary part. */
2929 if (typecode == COMPLEX_TYPE)
2930 {
2931 tree real, imag;
2932
2933 if (pedantic)
2934 pedwarn ("ISO C does not support %<++%> and %<--%>"
2935 " on complex types");
2936
2937 arg = stabilize_reference (arg);
2938 real = build_unary_op (REALPART_EXPR, arg, 1);
2939 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2940 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
2941 build_unary_op (code, real, 1), imag);
2942 }
2943
2944 /* Report invalid types. */
2945
2946 if (typecode != POINTER_TYPE
2947 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2948 {
2949 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2950 error ("wrong type argument to increment");
2951 else
2952 error ("wrong type argument to decrement");
2953
2954 return error_mark_node;
2955 }
2956
2957 {
2958 tree inc;
2959 tree result_type = TREE_TYPE (arg);
2960
2961 arg = get_unwidened (arg, 0);
2962 argtype = TREE_TYPE (arg);
2963
2964 /* Compute the increment. */
2965
2966 if (typecode == POINTER_TYPE)
2967 {
2968 /* If pointer target is an undefined struct,
2969 we just cannot know how to do the arithmetic. */
2970 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2971 {
2972 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2973 error ("increment of pointer to unknown structure");
2974 else
2975 error ("decrement of pointer to unknown structure");
2976 }
2977 else if ((pedantic || warn_pointer_arith)
2978 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2979 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2980 {
2981 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2982 pedwarn ("wrong type argument to increment");
2983 else
2984 pedwarn ("wrong type argument to decrement");
2985 }
2986
2987 inc = c_size_in_bytes (TREE_TYPE (result_type));
2988 }
2989 else
2990 inc = integer_one_node;
2991
2992 inc = convert (argtype, inc);
2993
2994 /* Complain about anything else that is not a true lvalue. */
2995 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
2996 || code == POSTINCREMENT_EXPR)
2997 ? lv_increment
2998 : lv_decrement)))
2999 return error_mark_node;
3000
3001 /* Report a read-only lvalue. */
3002 if (TREE_READONLY (arg))
3003 {
3004 readonly_error (arg,
3005 ((code == PREINCREMENT_EXPR
3006 || code == POSTINCREMENT_EXPR)
3007 ? lv_increment : lv_decrement));
3008 return error_mark_node;
3009 }
3010
3011 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3012 val = boolean_increment (code, arg);
3013 else
3014 val = build2 (code, TREE_TYPE (arg), arg, inc);
3015 TREE_SIDE_EFFECTS (val) = 1;
3016 val = convert (result_type, val);
3017 if (TREE_CODE (val) != code)
3018 TREE_NO_WARNING (val) = 1;
3019 return val;
3020 }
3021
3022 case ADDR_EXPR:
3023 /* Note that this operation never does default_conversion. */
3024
3025 /* Let &* cancel out to simplify resulting code. */
3026 if (TREE_CODE (arg) == INDIRECT_REF)
3027 {
3028 /* Don't let this be an lvalue. */
3029 if (lvalue_p (TREE_OPERAND (arg, 0)))
3030 return non_lvalue (TREE_OPERAND (arg, 0));
3031 return TREE_OPERAND (arg, 0);
3032 }
3033
3034 /* For &x[y], return x+y */
3035 if (TREE_CODE (arg) == ARRAY_REF)
3036 {
3037 tree op0 = TREE_OPERAND (arg, 0);
3038 if (!c_mark_addressable (op0))
3039 return error_mark_node;
3040 return build_binary_op (PLUS_EXPR,
3041 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
3042 ? array_to_pointer_conversion (op0)
3043 : op0),
3044 TREE_OPERAND (arg, 1), 1);
3045 }
3046
3047 /* Anything not already handled and not a true memory reference
3048 or a non-lvalue array is an error. */
3049 else if (typecode != FUNCTION_TYPE && !flag
3050 && !lvalue_or_else (arg, lv_addressof))
3051 return error_mark_node;
3052
3053 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3054 argtype = TREE_TYPE (arg);
3055
3056 /* If the lvalue is const or volatile, merge that into the type
3057 to which the address will point. Note that you can't get a
3058 restricted pointer by taking the address of something, so we
3059 only have to deal with `const' and `volatile' here. */
3060 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3061 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3062 argtype = c_build_type_variant (argtype,
3063 TREE_READONLY (arg),
3064 TREE_THIS_VOLATILE (arg));
3065
3066 if (!c_mark_addressable (arg))
3067 return error_mark_node;
3068
3069 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3070 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3071
3072 argtype = build_pointer_type (argtype);
3073
3074 /* ??? Cope with user tricks that amount to offsetof. Delete this
3075 when we have proper support for integer constant expressions. */
3076 val = get_base_address (arg);
3077 if (val && TREE_CODE (val) == INDIRECT_REF
3078 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3079 {
3080 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1;
3081
3082 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3083 return fold_build2 (PLUS_EXPR, argtype, op0, op1);
3084 }
3085
3086 val = build1 (ADDR_EXPR, argtype, arg);
3087
3088 return val;
3089
3090 default:
3091 gcc_unreachable ();
3092 }
3093
3094 if (argtype == 0)
3095 argtype = TREE_TYPE (arg);
3096 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3097 : fold_build1 (code, argtype, arg);
3098 }
3099
3100 /* Return nonzero if REF is an lvalue valid for this language.
3101 Lvalues can be assigned, unless their type has TYPE_READONLY.
3102 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3103
3104 static int
3105 lvalue_p (tree ref)
3106 {
3107 enum tree_code code = TREE_CODE (ref);
3108
3109 switch (code)
3110 {
3111 case REALPART_EXPR:
3112 case IMAGPART_EXPR:
3113 case COMPONENT_REF:
3114 return lvalue_p (TREE_OPERAND (ref, 0));
3115
3116 case COMPOUND_LITERAL_EXPR:
3117 case STRING_CST:
3118 return 1;
3119
3120 case INDIRECT_REF:
3121 case ARRAY_REF:
3122 case VAR_DECL:
3123 case PARM_DECL:
3124 case RESULT_DECL:
3125 case ERROR_MARK:
3126 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3127 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3128
3129 case BIND_EXPR:
3130 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3131
3132 default:
3133 return 0;
3134 }
3135 }
3136 \f
3137 /* Give an error for storing in something that is 'const'. */
3138
3139 static void
3140 readonly_error (tree arg, enum lvalue_use use)
3141 {
3142 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3143 || use == lv_asm);
3144 /* Using this macro rather than (for example) arrays of messages
3145 ensures that all the format strings are checked at compile
3146 time. */
3147 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3148 : (use == lv_increment ? (I) \
3149 : (use == lv_decrement ? (D) : (AS))))
3150 if (TREE_CODE (arg) == COMPONENT_REF)
3151 {
3152 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3153 readonly_error (TREE_OPERAND (arg, 0), use);
3154 else
3155 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3156 G_("increment of read-only member %qD"),
3157 G_("decrement of read-only member %qD"),
3158 G_("read-only member %qD used as %<asm%> output")),
3159 TREE_OPERAND (arg, 1));
3160 }
3161 else if (TREE_CODE (arg) == VAR_DECL)
3162 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3163 G_("increment of read-only variable %qD"),
3164 G_("decrement of read-only variable %qD"),
3165 G_("read-only variable %qD used as %<asm%> output")),
3166 arg);
3167 else
3168 error (READONLY_MSG (G_("assignment of read-only location"),
3169 G_("increment of read-only location"),
3170 G_("decrement of read-only location"),
3171 G_("read-only location used as %<asm%> output")));
3172 }
3173
3174
3175 /* Return nonzero if REF is an lvalue valid for this language;
3176 otherwise, print an error message and return zero. USE says
3177 how the lvalue is being used and so selects the error message. */
3178
3179 static int
3180 lvalue_or_else (tree ref, enum lvalue_use use)
3181 {
3182 int win = lvalue_p (ref);
3183
3184 if (!win)
3185 lvalue_error (use);
3186
3187 return win;
3188 }
3189 \f
3190 /* Mark EXP saying that we need to be able to take the
3191 address of it; it should not be allocated in a register.
3192 Returns true if successful. */
3193
3194 bool
3195 c_mark_addressable (tree exp)
3196 {
3197 tree x = exp;
3198
3199 while (1)
3200 switch (TREE_CODE (x))
3201 {
3202 case COMPONENT_REF:
3203 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3204 {
3205 error
3206 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3207 return false;
3208 }
3209
3210 /* ... fall through ... */
3211
3212 case ADDR_EXPR:
3213 case ARRAY_REF:
3214 case REALPART_EXPR:
3215 case IMAGPART_EXPR:
3216 x = TREE_OPERAND (x, 0);
3217 break;
3218
3219 case COMPOUND_LITERAL_EXPR:
3220 case CONSTRUCTOR:
3221 TREE_ADDRESSABLE (x) = 1;
3222 return true;
3223
3224 case VAR_DECL:
3225 case CONST_DECL:
3226 case PARM_DECL:
3227 case RESULT_DECL:
3228 if (C_DECL_REGISTER (x)
3229 && DECL_NONLOCAL (x))
3230 {
3231 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3232 {
3233 error
3234 ("global register variable %qD used in nested function", x);
3235 return false;
3236 }
3237 pedwarn ("register variable %qD used in nested function", x);
3238 }
3239 else if (C_DECL_REGISTER (x))
3240 {
3241 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3242 error ("address of global register variable %qD requested", x);
3243 else
3244 error ("address of register variable %qD requested", x);
3245 return false;
3246 }
3247
3248 /* drops in */
3249 case FUNCTION_DECL:
3250 TREE_ADDRESSABLE (x) = 1;
3251 /* drops out */
3252 default:
3253 return true;
3254 }
3255 }
3256 \f
3257 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3258
3259 tree
3260 build_conditional_expr (tree ifexp, tree op1, tree op2)
3261 {
3262 tree type1;
3263 tree type2;
3264 enum tree_code code1;
3265 enum tree_code code2;
3266 tree result_type = NULL;
3267 tree orig_op1 = op1, orig_op2 = op2;
3268
3269 /* Promote both alternatives. */
3270
3271 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3272 op1 = default_conversion (op1);
3273 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3274 op2 = default_conversion (op2);
3275
3276 if (TREE_CODE (ifexp) == ERROR_MARK
3277 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3278 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3279 return error_mark_node;
3280
3281 type1 = TREE_TYPE (op1);
3282 code1 = TREE_CODE (type1);
3283 type2 = TREE_TYPE (op2);
3284 code2 = TREE_CODE (type2);
3285
3286 /* C90 does not permit non-lvalue arrays in conditional expressions.
3287 In C99 they will be pointers by now. */
3288 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3289 {
3290 error ("non-lvalue array in conditional expression");
3291 return error_mark_node;
3292 }
3293
3294 /* Quickly detect the usual case where op1 and op2 have the same type
3295 after promotion. */
3296 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3297 {
3298 if (type1 == type2)
3299 result_type = type1;
3300 else
3301 result_type = TYPE_MAIN_VARIANT (type1);
3302 }
3303 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3304 || code1 == COMPLEX_TYPE)
3305 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3306 || code2 == COMPLEX_TYPE))
3307 {
3308 result_type = c_common_type (type1, type2);
3309
3310 /* If -Wsign-compare, warn here if type1 and type2 have
3311 different signedness. We'll promote the signed to unsigned
3312 and later code won't know it used to be different.
3313 Do this check on the original types, so that explicit casts
3314 will be considered, but default promotions won't. */
3315 if (warn_sign_compare && !skip_evaluation)
3316 {
3317 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3318 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3319
3320 if (unsigned_op1 ^ unsigned_op2)
3321 {
3322 /* Do not warn if the result type is signed, since the
3323 signed type will only be chosen if it can represent
3324 all the values of the unsigned type. */
3325 if (!TYPE_UNSIGNED (result_type))
3326 /* OK */;
3327 /* Do not warn if the signed quantity is an unsuffixed
3328 integer literal (or some static constant expression
3329 involving such literals) and it is non-negative. */
3330 else if ((unsigned_op2 && tree_expr_nonnegative_p (op1))
3331 || (unsigned_op1 && tree_expr_nonnegative_p (op2)))
3332 /* OK */;
3333 else
3334 warning (0, "signed and unsigned type in conditional expression");
3335 }
3336 }
3337 }
3338 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3339 {
3340 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3341 pedwarn ("ISO C forbids conditional expr with only one void side");
3342 result_type = void_type_node;
3343 }
3344 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3345 {
3346 if (comp_target_types (type1, type2))
3347 result_type = common_pointer_type (type1, type2);
3348 else if (null_pointer_constant_p (orig_op1))
3349 result_type = qualify_type (type2, type1);
3350 else if (null_pointer_constant_p (orig_op2))
3351 result_type = qualify_type (type1, type2);
3352 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3353 {
3354 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3355 pedwarn ("ISO C forbids conditional expr between "
3356 "%<void *%> and function pointer");
3357 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3358 TREE_TYPE (type2)));
3359 }
3360 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3361 {
3362 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3363 pedwarn ("ISO C forbids conditional expr between "
3364 "%<void *%> and function pointer");
3365 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3366 TREE_TYPE (type1)));
3367 }
3368 else
3369 {
3370 pedwarn ("pointer type mismatch in conditional expression");
3371 result_type = build_pointer_type (void_type_node);
3372 }
3373 }
3374 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3375 {
3376 if (!null_pointer_constant_p (orig_op2))
3377 pedwarn ("pointer/integer type mismatch in conditional expression");
3378 else
3379 {
3380 op2 = null_pointer_node;
3381 }
3382 result_type = type1;
3383 }
3384 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3385 {
3386 if (!null_pointer_constant_p (orig_op1))
3387 pedwarn ("pointer/integer type mismatch in conditional expression");
3388 else
3389 {
3390 op1 = null_pointer_node;
3391 }
3392 result_type = type2;
3393 }
3394
3395 if (!result_type)
3396 {
3397 if (flag_cond_mismatch)
3398 result_type = void_type_node;
3399 else
3400 {
3401 error ("type mismatch in conditional expression");
3402 return error_mark_node;
3403 }
3404 }
3405
3406 /* Merge const and volatile flags of the incoming types. */
3407 result_type
3408 = build_type_variant (result_type,
3409 TREE_READONLY (op1) || TREE_READONLY (op2),
3410 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3411
3412 if (result_type != TREE_TYPE (op1))
3413 op1 = convert_and_check (result_type, op1);
3414 if (result_type != TREE_TYPE (op2))
3415 op2 = convert_and_check (result_type, op2);
3416
3417 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3418 }
3419 \f
3420 /* Return a compound expression that performs two expressions and
3421 returns the value of the second of them. */
3422
3423 tree
3424 build_compound_expr (tree expr1, tree expr2)
3425 {
3426 if (!TREE_SIDE_EFFECTS (expr1))
3427 {
3428 /* The left-hand operand of a comma expression is like an expression
3429 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3430 any side-effects, unless it was explicitly cast to (void). */
3431 if (warn_unused_value)
3432 {
3433 if (VOID_TYPE_P (TREE_TYPE (expr1))
3434 && (TREE_CODE (expr1) == NOP_EXPR
3435 || TREE_CODE (expr1) == CONVERT_EXPR))
3436 ; /* (void) a, b */
3437 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3438 && TREE_CODE (expr1) == COMPOUND_EXPR
3439 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR
3440 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR))
3441 ; /* (void) a, (void) b, c */
3442 else
3443 warning (0, "left-hand operand of comma expression has no effect");
3444 }
3445 }
3446
3447 /* With -Wunused, we should also warn if the left-hand operand does have
3448 side-effects, but computes a value which is not used. For example, in
3449 `foo() + bar(), baz()' the result of the `+' operator is not used,
3450 so we should issue a warning. */
3451 else if (warn_unused_value)
3452 warn_if_unused_value (expr1, input_location);
3453
3454 if (expr2 == error_mark_node)
3455 return error_mark_node;
3456
3457 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3458 }
3459
3460 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3461
3462 tree
3463 build_c_cast (tree type, tree expr)
3464 {
3465 tree value = expr;
3466
3467 if (type == error_mark_node || expr == error_mark_node)
3468 return error_mark_node;
3469
3470 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3471 only in <protocol> qualifications. But when constructing cast expressions,
3472 the protocols do matter and must be kept around. */
3473 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3474 return build1 (NOP_EXPR, type, expr);
3475
3476 type = TYPE_MAIN_VARIANT (type);
3477
3478 if (TREE_CODE (type) == ARRAY_TYPE)
3479 {
3480 error ("cast specifies array type");
3481 return error_mark_node;
3482 }
3483
3484 if (TREE_CODE (type) == FUNCTION_TYPE)
3485 {
3486 error ("cast specifies function type");
3487 return error_mark_node;
3488 }
3489
3490 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3491 {
3492 if (pedantic)
3493 {
3494 if (TREE_CODE (type) == RECORD_TYPE
3495 || TREE_CODE (type) == UNION_TYPE)
3496 pedwarn ("ISO C forbids casting nonscalar to the same type");
3497 }
3498 }
3499 else if (TREE_CODE (type) == UNION_TYPE)
3500 {
3501 tree field;
3502
3503 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3504 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3505 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3506 break;
3507
3508 if (field)
3509 {
3510 tree t;
3511
3512 if (pedantic)
3513 pedwarn ("ISO C forbids casts to union type");
3514 t = digest_init (type,
3515 build_constructor_single (type, field, value),
3516 true, 0);
3517 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3518 TREE_INVARIANT (t) = TREE_INVARIANT (value);
3519 return t;
3520 }
3521 error ("cast to union type from type not present in union");
3522 return error_mark_node;
3523 }
3524 else
3525 {
3526 tree otype, ovalue;
3527
3528 if (type == void_type_node)
3529 return build1 (CONVERT_EXPR, type, value);
3530
3531 otype = TREE_TYPE (value);
3532
3533 /* Optionally warn about potentially worrisome casts. */
3534
3535 if (warn_cast_qual
3536 && TREE_CODE (type) == POINTER_TYPE
3537 && TREE_CODE (otype) == POINTER_TYPE)
3538 {
3539 tree in_type = type;
3540 tree in_otype = otype;
3541 int added = 0;
3542 int discarded = 0;
3543
3544 /* Check that the qualifiers on IN_TYPE are a superset of
3545 the qualifiers of IN_OTYPE. The outermost level of
3546 POINTER_TYPE nodes is uninteresting and we stop as soon
3547 as we hit a non-POINTER_TYPE node on either type. */
3548 do
3549 {
3550 in_otype = TREE_TYPE (in_otype);
3551 in_type = TREE_TYPE (in_type);
3552
3553 /* GNU C allows cv-qualified function types. 'const'
3554 means the function is very pure, 'volatile' means it
3555 can't return. We need to warn when such qualifiers
3556 are added, not when they're taken away. */
3557 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3558 && TREE_CODE (in_type) == FUNCTION_TYPE)
3559 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3560 else
3561 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3562 }
3563 while (TREE_CODE (in_type) == POINTER_TYPE
3564 && TREE_CODE (in_otype) == POINTER_TYPE);
3565
3566 if (added)
3567 warning (0, "cast adds new qualifiers to function type");
3568
3569 if (discarded)
3570 /* There are qualifiers present in IN_OTYPE that are not
3571 present in IN_TYPE. */
3572 warning (0, "cast discards qualifiers from pointer target type");
3573 }
3574
3575 /* Warn about possible alignment problems. */
3576 if (STRICT_ALIGNMENT
3577 && TREE_CODE (type) == POINTER_TYPE
3578 && TREE_CODE (otype) == POINTER_TYPE
3579 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3580 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3581 /* Don't warn about opaque types, where the actual alignment
3582 restriction is unknown. */
3583 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3584 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3585 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3586 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3587 warning (OPT_Wcast_align,
3588 "cast increases required alignment of target type");
3589
3590 if (TREE_CODE (type) == INTEGER_TYPE
3591 && TREE_CODE (otype) == POINTER_TYPE
3592 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3593 /* Unlike conversion of integers to pointers, where the
3594 warning is disabled for converting constants because
3595 of cases such as SIG_*, warn about converting constant
3596 pointers to integers. In some cases it may cause unwanted
3597 sign extension, and a warning is appropriate. */
3598 warning (OPT_Wpointer_to_int_cast,
3599 "cast from pointer to integer of different size");
3600
3601 if (TREE_CODE (value) == CALL_EXPR
3602 && TREE_CODE (type) != TREE_CODE (otype))
3603 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3604 "to non-matching type %qT", otype, type);
3605
3606 if (TREE_CODE (type) == POINTER_TYPE
3607 && TREE_CODE (otype) == INTEGER_TYPE
3608 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3609 /* Don't warn about converting any constant. */
3610 && !TREE_CONSTANT (value))
3611 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3612 "of different size");
3613
3614 strict_aliasing_warning (otype, type, expr);
3615
3616 /* If pedantic, warn for conversions between function and object
3617 pointer types, except for converting a null pointer constant
3618 to function pointer type. */
3619 if (pedantic
3620 && TREE_CODE (type) == POINTER_TYPE
3621 && TREE_CODE (otype) == POINTER_TYPE
3622 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3623 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3624 pedwarn ("ISO C forbids conversion of function pointer to object pointer type");
3625
3626 if (pedantic
3627 && TREE_CODE (type) == POINTER_TYPE
3628 && TREE_CODE (otype) == POINTER_TYPE
3629 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3630 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3631 && !null_pointer_constant_p (value))
3632 pedwarn ("ISO C forbids conversion of object pointer to function pointer type");
3633
3634 ovalue = value;
3635 value = convert (type, value);
3636
3637 /* Ignore any integer overflow caused by the cast. */
3638 if (TREE_CODE (value) == INTEGER_CST)
3639 {
3640 if (CONSTANT_CLASS_P (ovalue)
3641 && (TREE_OVERFLOW (ovalue) || TREE_CONSTANT_OVERFLOW (ovalue)))
3642 {
3643 /* Avoid clobbering a shared constant. */
3644 value = copy_node (value);
3645 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3646 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
3647 }
3648 else if (TREE_OVERFLOW (value) || TREE_CONSTANT_OVERFLOW (value))
3649 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3650 value = build_int_cst_wide (TREE_TYPE (value),
3651 TREE_INT_CST_LOW (value),
3652 TREE_INT_CST_HIGH (value));
3653 }
3654 }
3655
3656 /* Don't let a cast be an lvalue. */
3657 if (value == expr)
3658 value = non_lvalue (value);
3659
3660 return value;
3661 }
3662
3663 /* Interpret a cast of expression EXPR to type TYPE. */
3664 tree
3665 c_cast_expr (struct c_type_name *type_name, tree expr)
3666 {
3667 tree type;
3668 int saved_wsp = warn_strict_prototypes;
3669
3670 /* This avoids warnings about unprototyped casts on
3671 integers. E.g. "#define SIG_DFL (void(*)())0". */
3672 if (TREE_CODE (expr) == INTEGER_CST)
3673 warn_strict_prototypes = 0;
3674 type = groktypename (type_name);
3675 warn_strict_prototypes = saved_wsp;
3676
3677 return build_c_cast (type, expr);
3678 }
3679 \f
3680 /* Build an assignment expression of lvalue LHS from value RHS.
3681 MODIFYCODE is the code for a binary operator that we use
3682 to combine the old value of LHS with RHS to get the new value.
3683 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3684
3685 tree
3686 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3687 {
3688 tree result;
3689 tree newrhs;
3690 tree lhstype = TREE_TYPE (lhs);
3691 tree olhstype = lhstype;
3692
3693 /* Types that aren't fully specified cannot be used in assignments. */
3694 lhs = require_complete_type (lhs);
3695
3696 /* Avoid duplicate error messages from operands that had errors. */
3697 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3698 return error_mark_node;
3699
3700 if (!lvalue_or_else (lhs, lv_assign))
3701 return error_mark_node;
3702
3703 STRIP_TYPE_NOPS (rhs);
3704
3705 newrhs = rhs;
3706
3707 /* If a binary op has been requested, combine the old LHS value with the RHS
3708 producing the value we should actually store into the LHS. */
3709
3710 if (modifycode != NOP_EXPR)
3711 {
3712 lhs = stabilize_reference (lhs);
3713 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3714 }
3715
3716 /* Give an error for storing in something that is 'const'. */
3717
3718 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3719 || ((TREE_CODE (lhstype) == RECORD_TYPE
3720 || TREE_CODE (lhstype) == UNION_TYPE)
3721 && C_TYPE_FIELDS_READONLY (lhstype)))
3722 {
3723 readonly_error (lhs, lv_assign);
3724 return error_mark_node;
3725 }
3726
3727 /* If storing into a structure or union member,
3728 it has probably been given type `int'.
3729 Compute the type that would go with
3730 the actual amount of storage the member occupies. */
3731
3732 if (TREE_CODE (lhs) == COMPONENT_REF
3733 && (TREE_CODE (lhstype) == INTEGER_TYPE
3734 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3735 || TREE_CODE (lhstype) == REAL_TYPE
3736 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3737 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3738
3739 /* If storing in a field that is in actuality a short or narrower than one,
3740 we must store in the field in its actual type. */
3741
3742 if (lhstype != TREE_TYPE (lhs))
3743 {
3744 lhs = copy_node (lhs);
3745 TREE_TYPE (lhs) = lhstype;
3746 }
3747
3748 /* Convert new value to destination type. */
3749
3750 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3751 NULL_TREE, NULL_TREE, 0);
3752 if (TREE_CODE (newrhs) == ERROR_MARK)
3753 return error_mark_node;
3754
3755 /* Emit ObjC write barrier, if necessary. */
3756 if (c_dialect_objc () && flag_objc_gc)
3757 {
3758 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3759 if (result)
3760 return result;
3761 }
3762
3763 /* Scan operands. */
3764
3765 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3766 TREE_SIDE_EFFECTS (result) = 1;
3767
3768 /* If we got the LHS in a different type for storing in,
3769 convert the result back to the nominal type of LHS
3770 so that the value we return always has the same type
3771 as the LHS argument. */
3772
3773 if (olhstype == TREE_TYPE (result))
3774 return result;
3775 return convert_for_assignment (olhstype, result, ic_assign,
3776 NULL_TREE, NULL_TREE, 0);
3777 }
3778 \f
3779 /* Convert value RHS to type TYPE as preparation for an assignment
3780 to an lvalue of type TYPE.
3781 The real work of conversion is done by `convert'.
3782 The purpose of this function is to generate error messages
3783 for assignments that are not allowed in C.
3784 ERRTYPE says whether it is argument passing, assignment,
3785 initialization or return.
3786
3787 FUNCTION is a tree for the function being called.
3788 PARMNUM is the number of the argument, for printing in error messages. */
3789
3790 static tree
3791 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3792 tree fundecl, tree function, int parmnum)
3793 {
3794 enum tree_code codel = TREE_CODE (type);
3795 tree rhstype;
3796 enum tree_code coder;
3797 tree rname = NULL_TREE;
3798 bool objc_ok = false;
3799
3800 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3801 {
3802 tree selector;
3803 /* Change pointer to function to the function itself for
3804 diagnostics. */
3805 if (TREE_CODE (function) == ADDR_EXPR
3806 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3807 function = TREE_OPERAND (function, 0);
3808
3809 /* Handle an ObjC selector specially for diagnostics. */
3810 selector = objc_message_selector ();
3811 rname = function;
3812 if (selector && parmnum > 2)
3813 {
3814 rname = selector;
3815 parmnum -= 2;
3816 }
3817 }
3818
3819 /* This macro is used to emit diagnostics to ensure that all format
3820 strings are complete sentences, visible to gettext and checked at
3821 compile time. */
3822 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3823 do { \
3824 switch (errtype) \
3825 { \
3826 case ic_argpass: \
3827 pedwarn (AR, parmnum, rname); \
3828 break; \
3829 case ic_argpass_nonproto: \
3830 warning (0, AR, parmnum, rname); \
3831 break; \
3832 case ic_assign: \
3833 pedwarn (AS); \
3834 break; \
3835 case ic_init: \
3836 pedwarn (IN); \
3837 break; \
3838 case ic_return: \
3839 pedwarn (RE); \
3840 break; \
3841 default: \
3842 gcc_unreachable (); \
3843 } \
3844 } while (0)
3845
3846 STRIP_TYPE_NOPS (rhs);
3847
3848 if (optimize && TREE_CODE (rhs) == VAR_DECL
3849 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
3850 rhs = decl_constant_value_for_broken_optimization (rhs);
3851
3852 rhstype = TREE_TYPE (rhs);
3853 coder = TREE_CODE (rhstype);
3854
3855 if (coder == ERROR_MARK)
3856 return error_mark_node;
3857
3858 if (c_dialect_objc ())
3859 {
3860 int parmno;
3861
3862 switch (errtype)
3863 {
3864 case ic_return:
3865 parmno = 0;
3866 break;
3867
3868 case ic_assign:
3869 parmno = -1;
3870 break;
3871
3872 case ic_init:
3873 parmno = -2;
3874 break;
3875
3876 default:
3877 parmno = parmnum;
3878 break;
3879 }
3880
3881 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
3882 }
3883
3884 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
3885 {
3886 overflow_warning (rhs);
3887 return rhs;
3888 }
3889
3890 if (coder == VOID_TYPE)
3891 {
3892 /* Except for passing an argument to an unprototyped function,
3893 this is a constraint violation. When passing an argument to
3894 an unprototyped function, it is compile-time undefined;
3895 making it a constraint in that case was rejected in
3896 DR#252. */
3897 error ("void value not ignored as it ought to be");
3898 return error_mark_node;
3899 }
3900 /* A type converts to a reference to it.
3901 This code doesn't fully support references, it's just for the
3902 special case of va_start and va_copy. */
3903 if (codel == REFERENCE_TYPE
3904 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
3905 {
3906 if (!lvalue_p (rhs))
3907 {
3908 error ("cannot pass rvalue to reference parameter");
3909 return error_mark_node;
3910 }
3911 if (!c_mark_addressable (rhs))
3912 return error_mark_node;
3913 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
3914
3915 /* We already know that these two types are compatible, but they
3916 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3917 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3918 likely to be va_list, a typedef to __builtin_va_list, which
3919 is different enough that it will cause problems later. */
3920 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
3921 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
3922
3923 rhs = build1 (NOP_EXPR, type, rhs);
3924 return rhs;
3925 }
3926 /* Some types can interconvert without explicit casts. */
3927 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
3928 && vector_types_convertible_p (type, TREE_TYPE (rhs)))
3929 return convert (type, rhs);
3930 /* Arithmetic types all interconvert, and enum is treated like int. */
3931 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
3932 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
3933 || codel == BOOLEAN_TYPE)
3934 && (coder == INTEGER_TYPE || coder == REAL_TYPE
3935 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
3936 || coder == BOOLEAN_TYPE))
3937 return convert_and_check (type, rhs);
3938
3939 /* Conversion to a transparent union from its member types.
3940 This applies only to function arguments. */
3941 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
3942 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
3943 {
3944 tree memb, marginal_memb = NULL_TREE;
3945
3946 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
3947 {
3948 tree memb_type = TREE_TYPE (memb);
3949
3950 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
3951 TYPE_MAIN_VARIANT (rhstype)))
3952 break;
3953
3954 if (TREE_CODE (memb_type) != POINTER_TYPE)
3955 continue;
3956
3957 if (coder == POINTER_TYPE)
3958 {
3959 tree ttl = TREE_TYPE (memb_type);
3960 tree ttr = TREE_TYPE (rhstype);
3961
3962 /* Any non-function converts to a [const][volatile] void *
3963 and vice versa; otherwise, targets must be the same.
3964 Meanwhile, the lhs target must have all the qualifiers of
3965 the rhs. */
3966 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
3967 || comp_target_types (memb_type, rhstype))
3968 {
3969 /* If this type won't generate any warnings, use it. */
3970 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
3971 || ((TREE_CODE (ttr) == FUNCTION_TYPE
3972 && TREE_CODE (ttl) == FUNCTION_TYPE)
3973 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3974 == TYPE_QUALS (ttr))
3975 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3976 == TYPE_QUALS (ttl))))
3977 break;
3978
3979 /* Keep looking for a better type, but remember this one. */
3980 if (!marginal_memb)
3981 marginal_memb = memb;
3982 }
3983 }
3984
3985 /* Can convert integer zero to any pointer type. */
3986 if (null_pointer_constant_p (rhs))
3987 {
3988 rhs = null_pointer_node;
3989 break;
3990 }
3991 }
3992
3993 if (memb || marginal_memb)
3994 {
3995 if (!memb)
3996 {
3997 /* We have only a marginally acceptable member type;
3998 it needs a warning. */
3999 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
4000 tree ttr = TREE_TYPE (rhstype);
4001
4002 /* Const and volatile mean something different for function
4003 types, so the usual warnings are not appropriate. */
4004 if (TREE_CODE (ttr) == FUNCTION_TYPE
4005 && TREE_CODE (ttl) == FUNCTION_TYPE)
4006 {
4007 /* Because const and volatile on functions are
4008 restrictions that say the function will not do
4009 certain things, it is okay to use a const or volatile
4010 function where an ordinary one is wanted, but not
4011 vice-versa. */
4012 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4013 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE "
4014 "makes qualified function "
4015 "pointer from unqualified"),
4016 G_("assignment makes qualified "
4017 "function pointer from "
4018 "unqualified"),
4019 G_("initialization makes qualified "
4020 "function pointer from "
4021 "unqualified"),
4022 G_("return makes qualified function "
4023 "pointer from unqualified"));
4024 }
4025 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4026 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4027 "qualifiers from pointer target type"),
4028 G_("assignment discards qualifiers "
4029 "from pointer target type"),
4030 G_("initialization discards qualifiers "
4031 "from pointer target type"),
4032 G_("return discards qualifiers from "
4033 "pointer target type"));
4034
4035 memb = marginal_memb;
4036 }
4037
4038 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl)))
4039 pedwarn ("ISO C prohibits argument conversion to union type");
4040
4041 return build_constructor_single (type, memb, rhs);
4042 }
4043 }
4044
4045 /* Conversions among pointers */
4046 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4047 && (coder == codel))
4048 {
4049 tree ttl = TREE_TYPE (type);
4050 tree ttr = TREE_TYPE (rhstype);
4051 tree mvl = ttl;
4052 tree mvr = ttr;
4053 bool is_opaque_pointer;
4054 int target_cmp = 0; /* Cache comp_target_types () result. */
4055
4056 if (TREE_CODE (mvl) != ARRAY_TYPE)
4057 mvl = TYPE_MAIN_VARIANT (mvl);
4058 if (TREE_CODE (mvr) != ARRAY_TYPE)
4059 mvr = TYPE_MAIN_VARIANT (mvr);
4060 /* Opaque pointers are treated like void pointers. */
4061 is_opaque_pointer = (targetm.vector_opaque_p (type)
4062 || targetm.vector_opaque_p (rhstype))
4063 && TREE_CODE (ttl) == VECTOR_TYPE
4064 && TREE_CODE (ttr) == VECTOR_TYPE;
4065
4066 /* C++ does not allow the implicit conversion void* -> T*. However,
4067 for the purpose of reducing the number of false positives, we
4068 tolerate the special case of
4069
4070 int *p = NULL;
4071
4072 where NULL is typically defined in C to be '(void *) 0'. */
4073 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4074 warning (OPT_Wc___compat, "request for implicit conversion from "
4075 "%qT to %qT not permitted in C++", rhstype, type);
4076
4077 /* Check if the right-hand side has a format attribute but the
4078 left-hand side doesn't. */
4079 if (warn_missing_format_attribute
4080 && check_missing_format_attribute (type, rhstype))
4081 {
4082 switch (errtype)
4083 {
4084 case ic_argpass:
4085 case ic_argpass_nonproto:
4086 warning (OPT_Wmissing_format_attribute,
4087 "argument %d of %qE might be "
4088 "a candidate for a format attribute",
4089 parmnum, rname);
4090 break;
4091 case ic_assign:
4092 warning (OPT_Wmissing_format_attribute,
4093 "assignment left-hand side might be "
4094 "a candidate for a format attribute");
4095 break;
4096 case ic_init:
4097 warning (OPT_Wmissing_format_attribute,
4098 "initialization left-hand side might be "
4099 "a candidate for a format attribute");
4100 break;
4101 case ic_return:
4102 warning (OPT_Wmissing_format_attribute,
4103 "return type might be "
4104 "a candidate for a format attribute");
4105 break;
4106 default:
4107 gcc_unreachable ();
4108 }
4109 }
4110
4111 /* Any non-function converts to a [const][volatile] void *
4112 and vice versa; otherwise, targets must be the same.
4113 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4114 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4115 || (target_cmp = comp_target_types (type, rhstype))
4116 || is_opaque_pointer
4117 || (c_common_unsigned_type (mvl)
4118 == c_common_unsigned_type (mvr)))
4119 {
4120 if (pedantic
4121 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4122 ||
4123 (VOID_TYPE_P (ttr)
4124 && !null_pointer_constant_p (rhs)
4125 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4126 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of "
4127 "%qE between function pointer "
4128 "and %<void *%>"),
4129 G_("ISO C forbids assignment between "
4130 "function pointer and %<void *%>"),
4131 G_("ISO C forbids initialization between "
4132 "function pointer and %<void *%>"),
4133 G_("ISO C forbids return between function "
4134 "pointer and %<void *%>"));
4135 /* Const and volatile mean something different for function types,
4136 so the usual warnings are not appropriate. */
4137 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4138 && TREE_CODE (ttl) != FUNCTION_TYPE)
4139 {
4140 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4141 {
4142 /* Types differing only by the presence of the 'volatile'
4143 qualifier are acceptable if the 'volatile' has been added
4144 in by the Objective-C EH machinery. */
4145 if (!objc_type_quals_match (ttl, ttr))
4146 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4147 "qualifiers from pointer target type"),
4148 G_("assignment discards qualifiers "
4149 "from pointer target type"),
4150 G_("initialization discards qualifiers "
4151 "from pointer target type"),
4152 G_("return discards qualifiers from "
4153 "pointer target type"));
4154 }
4155 /* If this is not a case of ignoring a mismatch in signedness,
4156 no warning. */
4157 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4158 || target_cmp)
4159 ;
4160 /* If there is a mismatch, do warn. */
4161 else if (warn_pointer_sign)
4162 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument "
4163 "%d of %qE differ in signedness"),
4164 G_("pointer targets in assignment "
4165 "differ in signedness"),
4166 G_("pointer targets in initialization "
4167 "differ in signedness"),
4168 G_("pointer targets in return differ "
4169 "in signedness"));
4170 }
4171 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4172 && TREE_CODE (ttr) == FUNCTION_TYPE)
4173 {
4174 /* Because const and volatile on functions are restrictions
4175 that say the function will not do certain things,
4176 it is okay to use a const or volatile function
4177 where an ordinary one is wanted, but not vice-versa. */
4178 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4179 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4180 "qualified function pointer "
4181 "from unqualified"),
4182 G_("assignment makes qualified function "
4183 "pointer from unqualified"),
4184 G_("initialization makes qualified "
4185 "function pointer from unqualified"),
4186 G_("return makes qualified function "
4187 "pointer from unqualified"));
4188 }
4189 }
4190 else
4191 /* Avoid warning about the volatile ObjC EH puts on decls. */
4192 if (!objc_ok)
4193 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from "
4194 "incompatible pointer type"),
4195 G_("assignment from incompatible pointer type"),
4196 G_("initialization from incompatible "
4197 "pointer type"),
4198 G_("return from incompatible pointer type"));
4199
4200 return convert (type, rhs);
4201 }
4202 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4203 {
4204 /* ??? This should not be an error when inlining calls to
4205 unprototyped functions. */
4206 error ("invalid use of non-lvalue array");
4207 return error_mark_node;
4208 }
4209 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4210 {
4211 /* An explicit constant 0 can convert to a pointer,
4212 or one that results from arithmetic, even including
4213 a cast to integer type. */
4214 if (!null_pointer_constant_p (rhs))
4215 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4216 "pointer from integer without a cast"),
4217 G_("assignment makes pointer from integer "
4218 "without a cast"),
4219 G_("initialization makes pointer from "
4220 "integer without a cast"),
4221 G_("return makes pointer from integer "
4222 "without a cast"));
4223
4224 return convert (type, rhs);
4225 }
4226 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4227 {
4228 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer "
4229 "from pointer without a cast"),
4230 G_("assignment makes integer from pointer "
4231 "without a cast"),
4232 G_("initialization makes integer from pointer "
4233 "without a cast"),
4234 G_("return makes integer from pointer "
4235 "without a cast"));
4236 return convert (type, rhs);
4237 }
4238 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4239 return convert (type, rhs);
4240
4241 switch (errtype)
4242 {
4243 case ic_argpass:
4244 case ic_argpass_nonproto:
4245 /* ??? This should not be an error when inlining calls to
4246 unprototyped functions. */
4247 error ("incompatible type for argument %d of %qE", parmnum, rname);
4248 break;
4249 case ic_assign:
4250 error ("incompatible types in assignment");
4251 break;
4252 case ic_init:
4253 error ("incompatible types in initialization");
4254 break;
4255 case ic_return:
4256 error ("incompatible types in return");
4257 break;
4258 default:
4259 gcc_unreachable ();
4260 }
4261
4262 return error_mark_node;
4263 }
4264
4265 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
4266 is used for error and warning reporting and indicates which argument
4267 is being processed. */
4268
4269 tree
4270 c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum)
4271 {
4272 tree ret, type;
4273
4274 /* If FN was prototyped at the call site, the value has been converted
4275 already in convert_arguments.
4276 However, we might see a prototype now that was not in place when
4277 the function call was seen, so check that the VALUE actually matches
4278 PARM before taking an early exit. */
4279 if (!value
4280 || (TYPE_ARG_TYPES (TREE_TYPE (fn))
4281 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
4282 == TYPE_MAIN_VARIANT (TREE_TYPE (value)))))
4283 return value;
4284
4285 type = TREE_TYPE (parm);
4286 ret = convert_for_assignment (type, value,
4287 ic_argpass_nonproto, fn,
4288 fn, argnum);
4289 if (targetm.calls.promote_prototypes (TREE_TYPE (fn))
4290 && INTEGRAL_TYPE_P (type)
4291 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
4292 ret = default_conversion (ret);
4293 return ret;
4294 }
4295 \f
4296 /* If VALUE is a compound expr all of whose expressions are constant, then
4297 return its value. Otherwise, return error_mark_node.
4298
4299 This is for handling COMPOUND_EXPRs as initializer elements
4300 which is allowed with a warning when -pedantic is specified. */
4301
4302 static tree
4303 valid_compound_expr_initializer (tree value, tree endtype)
4304 {
4305 if (TREE_CODE (value) == COMPOUND_EXPR)
4306 {
4307 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4308 == error_mark_node)
4309 return error_mark_node;
4310 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4311 endtype);
4312 }
4313 else if (!initializer_constant_valid_p (value, endtype))
4314 return error_mark_node;
4315 else
4316 return value;
4317 }
4318 \f
4319 /* Perform appropriate conversions on the initial value of a variable,
4320 store it in the declaration DECL,
4321 and print any error messages that are appropriate.
4322 If the init is invalid, store an ERROR_MARK. */
4323
4324 void
4325 store_init_value (tree decl, tree init)
4326 {
4327 tree value, type;
4328
4329 /* If variable's type was invalidly declared, just ignore it. */
4330
4331 type = TREE_TYPE (decl);
4332 if (TREE_CODE (type) == ERROR_MARK)
4333 return;
4334
4335 /* Digest the specified initializer into an expression. */
4336
4337 value = digest_init (type, init, true, TREE_STATIC (decl));
4338
4339 /* Store the expression if valid; else report error. */
4340
4341 if (!in_system_header
4342 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4343 warning (OPT_Wtraditional, "traditional C rejects automatic "
4344 "aggregate initialization");
4345
4346 DECL_INITIAL (decl) = value;
4347
4348 /* ANSI wants warnings about out-of-range constant initializers. */
4349 STRIP_TYPE_NOPS (value);
4350 constant_expression_warning (value);
4351
4352 /* Check if we need to set array size from compound literal size. */
4353 if (TREE_CODE (type) == ARRAY_TYPE
4354 && TYPE_DOMAIN (type) == 0
4355 && value != error_mark_node)
4356 {
4357 tree inside_init = init;
4358
4359 STRIP_TYPE_NOPS (inside_init);
4360 inside_init = fold (inside_init);
4361
4362 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4363 {
4364 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4365
4366 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4367 {
4368 /* For int foo[] = (int [3]){1}; we need to set array size
4369 now since later on array initializer will be just the
4370 brace enclosed list of the compound literal. */
4371 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4372 TREE_TYPE (decl) = type;
4373 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4374 layout_type (type);
4375 layout_decl (cldecl, 0);
4376 }
4377 }
4378 }
4379 }
4380 \f
4381 /* Methods for storing and printing names for error messages. */
4382
4383 /* Implement a spelling stack that allows components of a name to be pushed
4384 and popped. Each element on the stack is this structure. */
4385
4386 struct spelling
4387 {
4388 int kind;
4389 union
4390 {
4391 unsigned HOST_WIDE_INT i;
4392 const char *s;
4393 } u;
4394 };
4395
4396 #define SPELLING_STRING 1
4397 #define SPELLING_MEMBER 2
4398 #define SPELLING_BOUNDS 3
4399
4400 static struct spelling *spelling; /* Next stack element (unused). */
4401 static struct spelling *spelling_base; /* Spelling stack base. */
4402 static int spelling_size; /* Size of the spelling stack. */
4403
4404 /* Macros to save and restore the spelling stack around push_... functions.
4405 Alternative to SAVE_SPELLING_STACK. */
4406
4407 #define SPELLING_DEPTH() (spelling - spelling_base)
4408 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4409
4410 /* Push an element on the spelling stack with type KIND and assign VALUE
4411 to MEMBER. */
4412
4413 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4414 { \
4415 int depth = SPELLING_DEPTH (); \
4416 \
4417 if (depth >= spelling_size) \
4418 { \
4419 spelling_size += 10; \
4420 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4421 spelling_size); \
4422 RESTORE_SPELLING_DEPTH (depth); \
4423 } \
4424 \
4425 spelling->kind = (KIND); \
4426 spelling->MEMBER = (VALUE); \
4427 spelling++; \
4428 }
4429
4430 /* Push STRING on the stack. Printed literally. */
4431
4432 static void
4433 push_string (const char *string)
4434 {
4435 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4436 }
4437
4438 /* Push a member name on the stack. Printed as '.' STRING. */
4439
4440 static void
4441 push_member_name (tree decl)
4442 {
4443 const char *const string
4444 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4445 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4446 }
4447
4448 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4449
4450 static void
4451 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4452 {
4453 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4454 }
4455
4456 /* Compute the maximum size in bytes of the printed spelling. */
4457
4458 static int
4459 spelling_length (void)
4460 {
4461 int size = 0;
4462 struct spelling *p;
4463
4464 for (p = spelling_base; p < spelling; p++)
4465 {
4466 if (p->kind == SPELLING_BOUNDS)
4467 size += 25;
4468 else
4469 size += strlen (p->u.s) + 1;
4470 }
4471
4472 return size;
4473 }
4474
4475 /* Print the spelling to BUFFER and return it. */
4476
4477 static char *
4478 print_spelling (char *buffer)
4479 {
4480 char *d = buffer;
4481 struct spelling *p;
4482
4483 for (p = spelling_base; p < spelling; p++)
4484 if (p->kind == SPELLING_BOUNDS)
4485 {
4486 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4487 d += strlen (d);
4488 }
4489 else
4490 {
4491 const char *s;
4492 if (p->kind == SPELLING_MEMBER)
4493 *d++ = '.';
4494 for (s = p->u.s; (*d = *s++); d++)
4495 ;
4496 }
4497 *d++ = '\0';
4498 return buffer;
4499 }
4500
4501 /* Issue an error message for a bad initializer component.
4502 MSGID identifies the message.
4503 The component name is taken from the spelling stack. */
4504
4505 void
4506 error_init (const char *msgid)
4507 {
4508 char *ofwhat;
4509
4510 error ("%s", _(msgid));
4511 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4512 if (*ofwhat)
4513 error ("(near initialization for %qs)", ofwhat);
4514 }
4515
4516 /* Issue a pedantic warning for a bad initializer component.
4517 MSGID identifies the message.
4518 The component name is taken from the spelling stack. */
4519
4520 void
4521 pedwarn_init (const char *msgid)
4522 {
4523 char *ofwhat;
4524
4525 pedwarn ("%s", _(msgid));
4526 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4527 if (*ofwhat)
4528 pedwarn ("(near initialization for %qs)", ofwhat);
4529 }
4530
4531 /* Issue a warning for a bad initializer component.
4532 MSGID identifies the message.
4533 The component name is taken from the spelling stack. */
4534
4535 static void
4536 warning_init (const char *msgid)
4537 {
4538 char *ofwhat;
4539
4540 warning (0, "%s", _(msgid));
4541 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4542 if (*ofwhat)
4543 warning (0, "(near initialization for %qs)", ofwhat);
4544 }
4545 \f
4546 /* If TYPE is an array type and EXPR is a parenthesized string
4547 constant, warn if pedantic that EXPR is being used to initialize an
4548 object of type TYPE. */
4549
4550 void
4551 maybe_warn_string_init (tree type, struct c_expr expr)
4552 {
4553 if (pedantic
4554 && TREE_CODE (type) == ARRAY_TYPE
4555 && TREE_CODE (expr.value) == STRING_CST
4556 && expr.original_code != STRING_CST)
4557 pedwarn_init ("array initialized from parenthesized string constant");
4558 }
4559
4560 /* Digest the parser output INIT as an initializer for type TYPE.
4561 Return a C expression of type TYPE to represent the initial value.
4562
4563 If INIT is a string constant, STRICT_STRING is true if it is
4564 unparenthesized or we should not warn here for it being parenthesized.
4565 For other types of INIT, STRICT_STRING is not used.
4566
4567 REQUIRE_CONSTANT requests an error if non-constant initializers or
4568 elements are seen. */
4569
4570 static tree
4571 digest_init (tree type, tree init, bool strict_string, int require_constant)
4572 {
4573 enum tree_code code = TREE_CODE (type);
4574 tree inside_init = init;
4575
4576 if (type == error_mark_node
4577 || !init
4578 || init == error_mark_node
4579 || TREE_TYPE (init) == error_mark_node)
4580 return error_mark_node;
4581
4582 STRIP_TYPE_NOPS (inside_init);
4583
4584 inside_init = fold (inside_init);
4585
4586 /* Initialization of an array of chars from a string constant
4587 optionally enclosed in braces. */
4588
4589 if (code == ARRAY_TYPE && inside_init
4590 && TREE_CODE (inside_init) == STRING_CST)
4591 {
4592 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4593 /* Note that an array could be both an array of character type
4594 and an array of wchar_t if wchar_t is signed char or unsigned
4595 char. */
4596 bool char_array = (typ1 == char_type_node
4597 || typ1 == signed_char_type_node
4598 || typ1 == unsigned_char_type_node);
4599 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4600 if (char_array || wchar_array)
4601 {
4602 struct c_expr expr;
4603 bool char_string;
4604 expr.value = inside_init;
4605 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4606 maybe_warn_string_init (type, expr);
4607
4608 char_string
4609 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4610 == char_type_node);
4611
4612 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4613 TYPE_MAIN_VARIANT (type)))
4614 return inside_init;
4615
4616 if (!wchar_array && !char_string)
4617 {
4618 error_init ("char-array initialized from wide string");
4619 return error_mark_node;
4620 }
4621 if (char_string && !char_array)
4622 {
4623 error_init ("wchar_t-array initialized from non-wide string");
4624 return error_mark_node;
4625 }
4626
4627 TREE_TYPE (inside_init) = type;
4628 if (TYPE_DOMAIN (type) != 0
4629 && TYPE_SIZE (type) != 0
4630 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4631 /* Subtract 1 (or sizeof (wchar_t))
4632 because it's ok to ignore the terminating null char
4633 that is counted in the length of the constant. */
4634 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4635 TREE_STRING_LENGTH (inside_init)
4636 - ((TYPE_PRECISION (typ1)
4637 != TYPE_PRECISION (char_type_node))
4638 ? (TYPE_PRECISION (wchar_type_node)
4639 / BITS_PER_UNIT)
4640 : 1)))
4641 pedwarn_init ("initializer-string for array of chars is too long");
4642
4643 return inside_init;
4644 }
4645 else if (INTEGRAL_TYPE_P (typ1))
4646 {
4647 error_init ("array of inappropriate type initialized "
4648 "from string constant");
4649 return error_mark_node;
4650 }
4651 }
4652
4653 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4654 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4655 below and handle as a constructor. */
4656 if (code == VECTOR_TYPE
4657 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4658 && vector_types_convertible_p (TREE_TYPE (inside_init), type)
4659 && TREE_CONSTANT (inside_init))
4660 {
4661 if (TREE_CODE (inside_init) == VECTOR_CST
4662 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4663 TYPE_MAIN_VARIANT (type)))
4664 return inside_init;
4665
4666 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4667 {
4668 unsigned HOST_WIDE_INT ix;
4669 tree value;
4670 bool constant_p = true;
4671
4672 /* Iterate through elements and check if all constructor
4673 elements are *_CSTs. */
4674 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4675 if (!CONSTANT_CLASS_P (value))
4676 {
4677 constant_p = false;
4678 break;
4679 }
4680
4681 if (constant_p)
4682 return build_vector_from_ctor (type,
4683 CONSTRUCTOR_ELTS (inside_init));
4684 }
4685 }
4686
4687 /* Any type can be initialized
4688 from an expression of the same type, optionally with braces. */
4689
4690 if (inside_init && TREE_TYPE (inside_init) != 0
4691 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4692 TYPE_MAIN_VARIANT (type))
4693 || (code == ARRAY_TYPE
4694 && comptypes (TREE_TYPE (inside_init), type))
4695 || (code == VECTOR_TYPE
4696 && comptypes (TREE_TYPE (inside_init), type))
4697 || (code == POINTER_TYPE
4698 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4699 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4700 TREE_TYPE (type)))))
4701 {
4702 if (code == POINTER_TYPE)
4703 {
4704 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4705 {
4706 if (TREE_CODE (inside_init) == STRING_CST
4707 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4708 inside_init = array_to_pointer_conversion (inside_init);
4709 else
4710 {
4711 error_init ("invalid use of non-lvalue array");
4712 return error_mark_node;
4713 }
4714 }
4715 }
4716
4717 if (code == VECTOR_TYPE)
4718 /* Although the types are compatible, we may require a
4719 conversion. */
4720 inside_init = convert (type, inside_init);
4721
4722 if (require_constant
4723 && (code == VECTOR_TYPE || !flag_isoc99)
4724 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4725 {
4726 /* As an extension, allow initializing objects with static storage
4727 duration with compound literals (which are then treated just as
4728 the brace enclosed list they contain). Also allow this for
4729 vectors, as we can only assign them with compound literals. */
4730 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4731 inside_init = DECL_INITIAL (decl);
4732 }
4733
4734 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4735 && TREE_CODE (inside_init) != CONSTRUCTOR)
4736 {
4737 error_init ("array initialized from non-constant array expression");
4738 return error_mark_node;
4739 }
4740
4741 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4742 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4743
4744 /* Compound expressions can only occur here if -pedantic or
4745 -pedantic-errors is specified. In the later case, we always want
4746 an error. In the former case, we simply want a warning. */
4747 if (require_constant && pedantic
4748 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4749 {
4750 inside_init
4751 = valid_compound_expr_initializer (inside_init,
4752 TREE_TYPE (inside_init));
4753 if (inside_init == error_mark_node)
4754 error_init ("initializer element is not constant");
4755 else
4756 pedwarn_init ("initializer element is not constant");
4757 if (flag_pedantic_errors)
4758 inside_init = error_mark_node;
4759 }
4760 else if (require_constant
4761 && !initializer_constant_valid_p (inside_init,
4762 TREE_TYPE (inside_init)))
4763 {
4764 error_init ("initializer element is not constant");
4765 inside_init = error_mark_node;
4766 }
4767
4768 /* Added to enable additional -Wmissing-format-attribute warnings. */
4769 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4770 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4771 NULL_TREE, 0);
4772 return inside_init;
4773 }
4774
4775 /* Handle scalar types, including conversions. */
4776
4777 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4778 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE
4779 || code == VECTOR_TYPE)
4780 {
4781 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4782 && (TREE_CODE (init) == STRING_CST
4783 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4784 init = array_to_pointer_conversion (init);
4785 inside_init
4786 = convert_for_assignment (type, init, ic_init,
4787 NULL_TREE, NULL_TREE, 0);
4788
4789 /* Check to see if we have already given an error message. */
4790 if (inside_init == error_mark_node)
4791 ;
4792 else if (require_constant && !TREE_CONSTANT (inside_init))
4793 {
4794 error_init ("initializer element is not constant");
4795 inside_init = error_mark_node;
4796 }
4797 else if (require_constant
4798 && !initializer_constant_valid_p (inside_init,
4799 TREE_TYPE (inside_init)))
4800 {
4801 error_init ("initializer element is not computable at load time");
4802 inside_init = error_mark_node;
4803 }
4804
4805 return inside_init;
4806 }
4807
4808 /* Come here only for records and arrays. */
4809
4810 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4811 {
4812 error_init ("variable-sized object may not be initialized");
4813 return error_mark_node;
4814 }
4815
4816 error_init ("invalid initializer");
4817 return error_mark_node;
4818 }
4819 \f
4820 /* Handle initializers that use braces. */
4821
4822 /* Type of object we are accumulating a constructor for.
4823 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4824 static tree constructor_type;
4825
4826 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4827 left to fill. */
4828 static tree constructor_fields;
4829
4830 /* For an ARRAY_TYPE, this is the specified index
4831 at which to store the next element we get. */
4832 static tree constructor_index;
4833
4834 /* For an ARRAY_TYPE, this is the maximum index. */
4835 static tree constructor_max_index;
4836
4837 /* For a RECORD_TYPE, this is the first field not yet written out. */
4838 static tree constructor_unfilled_fields;
4839
4840 /* For an ARRAY_TYPE, this is the index of the first element
4841 not yet written out. */
4842 static tree constructor_unfilled_index;
4843
4844 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4845 This is so we can generate gaps between fields, when appropriate. */
4846 static tree constructor_bit_index;
4847
4848 /* If we are saving up the elements rather than allocating them,
4849 this is the list of elements so far (in reverse order,
4850 most recent first). */
4851 static VEC(constructor_elt,gc) *constructor_elements;
4852
4853 /* 1 if constructor should be incrementally stored into a constructor chain,
4854 0 if all the elements should be kept in AVL tree. */
4855 static int constructor_incremental;
4856
4857 /* 1 if so far this constructor's elements are all compile-time constants. */
4858 static int constructor_constant;
4859
4860 /* 1 if so far this constructor's elements are all valid address constants. */
4861 static int constructor_simple;
4862
4863 /* 1 if this constructor is erroneous so far. */
4864 static int constructor_erroneous;
4865
4866 /* Structure for managing pending initializer elements, organized as an
4867 AVL tree. */
4868
4869 struct init_node
4870 {
4871 struct init_node *left, *right;
4872 struct init_node *parent;
4873 int balance;
4874 tree purpose;
4875 tree value;
4876 };
4877
4878 /* Tree of pending elements at this constructor level.
4879 These are elements encountered out of order
4880 which belong at places we haven't reached yet in actually
4881 writing the output.
4882 Will never hold tree nodes across GC runs. */
4883 static struct init_node *constructor_pending_elts;
4884
4885 /* The SPELLING_DEPTH of this constructor. */
4886 static int constructor_depth;
4887
4888 /* DECL node for which an initializer is being read.
4889 0 means we are reading a constructor expression
4890 such as (struct foo) {...}. */
4891 static tree constructor_decl;
4892
4893 /* Nonzero if this is an initializer for a top-level decl. */
4894 static int constructor_top_level;
4895
4896 /* Nonzero if there were any member designators in this initializer. */
4897 static int constructor_designated;
4898
4899 /* Nesting depth of designator list. */
4900 static int designator_depth;
4901
4902 /* Nonzero if there were diagnosed errors in this designator list. */
4903 static int designator_erroneous;
4904
4905 \f
4906 /* This stack has a level for each implicit or explicit level of
4907 structuring in the initializer, including the outermost one. It
4908 saves the values of most of the variables above. */
4909
4910 struct constructor_range_stack;
4911
4912 struct constructor_stack
4913 {
4914 struct constructor_stack *next;
4915 tree type;
4916 tree fields;
4917 tree index;
4918 tree max_index;
4919 tree unfilled_index;
4920 tree unfilled_fields;
4921 tree bit_index;
4922 VEC(constructor_elt,gc) *elements;
4923 struct init_node *pending_elts;
4924 int offset;
4925 int depth;
4926 /* If value nonzero, this value should replace the entire
4927 constructor at this level. */
4928 struct c_expr replacement_value;
4929 struct constructor_range_stack *range_stack;
4930 char constant;
4931 char simple;
4932 char implicit;
4933 char erroneous;
4934 char outer;
4935 char incremental;
4936 char designated;
4937 };
4938
4939 static struct constructor_stack *constructor_stack;
4940
4941 /* This stack represents designators from some range designator up to
4942 the last designator in the list. */
4943
4944 struct constructor_range_stack
4945 {
4946 struct constructor_range_stack *next, *prev;
4947 struct constructor_stack *stack;
4948 tree range_start;
4949 tree index;
4950 tree range_end;
4951 tree fields;
4952 };
4953
4954 static struct constructor_range_stack *constructor_range_stack;
4955
4956 /* This stack records separate initializers that are nested.
4957 Nested initializers can't happen in ANSI C, but GNU C allows them
4958 in cases like { ... (struct foo) { ... } ... }. */
4959
4960 struct initializer_stack
4961 {
4962 struct initializer_stack *next;
4963 tree decl;
4964 struct constructor_stack *constructor_stack;
4965 struct constructor_range_stack *constructor_range_stack;
4966 VEC(constructor_elt,gc) *elements;
4967 struct spelling *spelling;
4968 struct spelling *spelling_base;
4969 int spelling_size;
4970 char top_level;
4971 char require_constant_value;
4972 char require_constant_elements;
4973 };
4974
4975 static struct initializer_stack *initializer_stack;
4976 \f
4977 /* Prepare to parse and output the initializer for variable DECL. */
4978
4979 void
4980 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
4981 {
4982 const char *locus;
4983 struct initializer_stack *p = XNEW (struct initializer_stack);
4984
4985 p->decl = constructor_decl;
4986 p->require_constant_value = require_constant_value;
4987 p->require_constant_elements = require_constant_elements;
4988 p->constructor_stack = constructor_stack;
4989 p->constructor_range_stack = constructor_range_stack;
4990 p->elements = constructor_elements;
4991 p->spelling = spelling;
4992 p->spelling_base = spelling_base;
4993 p->spelling_size = spelling_size;
4994 p->top_level = constructor_top_level;
4995 p->next = initializer_stack;
4996 initializer_stack = p;
4997
4998 constructor_decl = decl;
4999 constructor_designated = 0;
5000 constructor_top_level = top_level;
5001
5002 if (decl != 0 && decl != error_mark_node)
5003 {
5004 require_constant_value = TREE_STATIC (decl);
5005 require_constant_elements
5006 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5007 /* For a scalar, you can always use any value to initialize,
5008 even within braces. */
5009 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5010 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5011 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5012 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5013 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5014 }
5015 else
5016 {
5017 require_constant_value = 0;
5018 require_constant_elements = 0;
5019 locus = "(anonymous)";
5020 }
5021
5022 constructor_stack = 0;
5023 constructor_range_stack = 0;
5024
5025 missing_braces_mentioned = 0;
5026
5027 spelling_base = 0;
5028 spelling_size = 0;
5029 RESTORE_SPELLING_DEPTH (0);
5030
5031 if (locus)
5032 push_string (locus);
5033 }
5034
5035 void
5036 finish_init (void)
5037 {
5038 struct initializer_stack *p = initializer_stack;
5039
5040 /* Free the whole constructor stack of this initializer. */
5041 while (constructor_stack)
5042 {
5043 struct constructor_stack *q = constructor_stack;
5044 constructor_stack = q->next;
5045 free (q);
5046 }
5047
5048 gcc_assert (!constructor_range_stack);
5049
5050 /* Pop back to the data of the outer initializer (if any). */
5051 free (spelling_base);
5052
5053 constructor_decl = p->decl;
5054 require_constant_value = p->require_constant_value;
5055 require_constant_elements = p->require_constant_elements;
5056 constructor_stack = p->constructor_stack;
5057 constructor_range_stack = p->constructor_range_stack;
5058 constructor_elements = p->elements;
5059 spelling = p->spelling;
5060 spelling_base = p->spelling_base;
5061 spelling_size = p->spelling_size;
5062 constructor_top_level = p->top_level;
5063 initializer_stack = p->next;
5064 free (p);
5065 }
5066 \f
5067 /* Call here when we see the initializer is surrounded by braces.
5068 This is instead of a call to push_init_level;
5069 it is matched by a call to pop_init_level.
5070
5071 TYPE is the type to initialize, for a constructor expression.
5072 For an initializer for a decl, TYPE is zero. */
5073
5074 void
5075 really_start_incremental_init (tree type)
5076 {
5077 struct constructor_stack *p = XNEW (struct constructor_stack);
5078
5079 if (type == 0)
5080 type = TREE_TYPE (constructor_decl);
5081
5082 if (targetm.vector_opaque_p (type))
5083 error ("opaque vector types cannot be initialized");
5084
5085 p->type = constructor_type;
5086 p->fields = constructor_fields;
5087 p->index = constructor_index;
5088 p->max_index = constructor_max_index;
5089 p->unfilled_index = constructor_unfilled_index;
5090 p->unfilled_fields = constructor_unfilled_fields;
5091 p->bit_index = constructor_bit_index;
5092 p->elements = constructor_elements;
5093 p->constant = constructor_constant;
5094 p->simple = constructor_simple;
5095 p->erroneous = constructor_erroneous;
5096 p->pending_elts = constructor_pending_elts;
5097 p->depth = constructor_depth;
5098 p->replacement_value.value = 0;
5099 p->replacement_value.original_code = ERROR_MARK;
5100 p->implicit = 0;
5101 p->range_stack = 0;
5102 p->outer = 0;
5103 p->incremental = constructor_incremental;
5104 p->designated = constructor_designated;
5105 p->next = 0;
5106 constructor_stack = p;
5107
5108 constructor_constant = 1;
5109 constructor_simple = 1;
5110 constructor_depth = SPELLING_DEPTH ();
5111 constructor_elements = 0;
5112 constructor_pending_elts = 0;
5113 constructor_type = type;
5114 constructor_incremental = 1;
5115 constructor_designated = 0;
5116 designator_depth = 0;
5117 designator_erroneous = 0;
5118
5119 if (TREE_CODE (constructor_type) == RECORD_TYPE
5120 || TREE_CODE (constructor_type) == UNION_TYPE)
5121 {
5122 constructor_fields = TYPE_FIELDS (constructor_type);
5123 /* Skip any nameless bit fields at the beginning. */
5124 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5125 && DECL_NAME (constructor_fields) == 0)
5126 constructor_fields = TREE_CHAIN (constructor_fields);
5127
5128 constructor_unfilled_fields = constructor_fields;
5129 constructor_bit_index = bitsize_zero_node;
5130 }
5131 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5132 {
5133 if (TYPE_DOMAIN (constructor_type))
5134 {
5135 constructor_max_index
5136 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5137
5138 /* Detect non-empty initializations of zero-length arrays. */
5139 if (constructor_max_index == NULL_TREE
5140 && TYPE_SIZE (constructor_type))
5141 constructor_max_index = build_int_cst (NULL_TREE, -1);
5142
5143 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5144 to initialize VLAs will cause a proper error; avoid tree
5145 checking errors as well by setting a safe value. */
5146 if (constructor_max_index
5147 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5148 constructor_max_index = build_int_cst (NULL_TREE, -1);
5149
5150 constructor_index
5151 = convert (bitsizetype,
5152 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5153 }
5154 else
5155 {
5156 constructor_index = bitsize_zero_node;
5157 constructor_max_index = NULL_TREE;
5158 }
5159
5160 constructor_unfilled_index = constructor_index;
5161 }
5162 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5163 {
5164 /* Vectors are like simple fixed-size arrays. */
5165 constructor_max_index =
5166 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5167 constructor_index = bitsize_zero_node;
5168 constructor_unfilled_index = constructor_index;
5169 }
5170 else
5171 {
5172 /* Handle the case of int x = {5}; */
5173 constructor_fields = constructor_type;
5174 constructor_unfilled_fields = constructor_type;
5175 }
5176 }
5177 \f
5178 /* Push down into a subobject, for initialization.
5179 If this is for an explicit set of braces, IMPLICIT is 0.
5180 If it is because the next element belongs at a lower level,
5181 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5182
5183 void
5184 push_init_level (int implicit)
5185 {
5186 struct constructor_stack *p;
5187 tree value = NULL_TREE;
5188
5189 /* If we've exhausted any levels that didn't have braces,
5190 pop them now. If implicit == 1, this will have been done in
5191 process_init_element; do not repeat it here because in the case
5192 of excess initializers for an empty aggregate this leads to an
5193 infinite cycle of popping a level and immediately recreating
5194 it. */
5195 if (implicit != 1)
5196 {
5197 while (constructor_stack->implicit)
5198 {
5199 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5200 || TREE_CODE (constructor_type) == UNION_TYPE)
5201 && constructor_fields == 0)
5202 process_init_element (pop_init_level (1));
5203 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5204 && constructor_max_index
5205 && tree_int_cst_lt (constructor_max_index,
5206 constructor_index))
5207 process_init_element (pop_init_level (1));
5208 else
5209 break;
5210 }
5211 }
5212
5213 /* Unless this is an explicit brace, we need to preserve previous
5214 content if any. */
5215 if (implicit)
5216 {
5217 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5218 || TREE_CODE (constructor_type) == UNION_TYPE)
5219 && constructor_fields)
5220 value = find_init_member (constructor_fields);
5221 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5222 value = find_init_member (constructor_index);
5223 }
5224
5225 p = XNEW (struct constructor_stack);
5226 p->type = constructor_type;
5227 p->fields = constructor_fields;
5228 p->index = constructor_index;
5229 p->max_index = constructor_max_index;
5230 p->unfilled_index = constructor_unfilled_index;
5231 p->unfilled_fields = constructor_unfilled_fields;
5232 p->bit_index = constructor_bit_index;
5233 p->elements = constructor_elements;
5234 p->constant = constructor_constant;
5235 p->simple = constructor_simple;
5236 p->erroneous = constructor_erroneous;
5237 p->pending_elts = constructor_pending_elts;
5238 p->depth = constructor_depth;
5239 p->replacement_value.value = 0;
5240 p->replacement_value.original_code = ERROR_MARK;
5241 p->implicit = implicit;
5242 p->outer = 0;
5243 p->incremental = constructor_incremental;
5244 p->designated = constructor_designated;
5245 p->next = constructor_stack;
5246 p->range_stack = 0;
5247 constructor_stack = p;
5248
5249 constructor_constant = 1;
5250 constructor_simple = 1;
5251 constructor_depth = SPELLING_DEPTH ();
5252 constructor_elements = 0;
5253 constructor_incremental = 1;
5254 constructor_designated = 0;
5255 constructor_pending_elts = 0;
5256 if (!implicit)
5257 {
5258 p->range_stack = constructor_range_stack;
5259 constructor_range_stack = 0;
5260 designator_depth = 0;
5261 designator_erroneous = 0;
5262 }
5263
5264 /* Don't die if an entire brace-pair level is superfluous
5265 in the containing level. */
5266 if (constructor_type == 0)
5267 ;
5268 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5269 || TREE_CODE (constructor_type) == UNION_TYPE)
5270 {
5271 /* Don't die if there are extra init elts at the end. */
5272 if (constructor_fields == 0)
5273 constructor_type = 0;
5274 else
5275 {
5276 constructor_type = TREE_TYPE (constructor_fields);
5277 push_member_name (constructor_fields);
5278 constructor_depth++;
5279 }
5280 }
5281 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5282 {
5283 constructor_type = TREE_TYPE (constructor_type);
5284 push_array_bounds (tree_low_cst (constructor_index, 1));
5285 constructor_depth++;
5286 }
5287
5288 if (constructor_type == 0)
5289 {
5290 error_init ("extra brace group at end of initializer");
5291 constructor_fields = 0;
5292 constructor_unfilled_fields = 0;
5293 return;
5294 }
5295
5296 if (value && TREE_CODE (value) == CONSTRUCTOR)
5297 {
5298 constructor_constant = TREE_CONSTANT (value);
5299 constructor_simple = TREE_STATIC (value);
5300 constructor_elements = CONSTRUCTOR_ELTS (value);
5301 if (!VEC_empty (constructor_elt, constructor_elements)
5302 && (TREE_CODE (constructor_type) == RECORD_TYPE
5303 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5304 set_nonincremental_init ();
5305 }
5306
5307 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5308 {
5309 missing_braces_mentioned = 1;
5310 warning_init ("missing braces around initializer");
5311 }
5312
5313 if (TREE_CODE (constructor_type) == RECORD_TYPE
5314 || TREE_CODE (constructor_type) == UNION_TYPE)
5315 {
5316 constructor_fields = TYPE_FIELDS (constructor_type);
5317 /* Skip any nameless bit fields at the beginning. */
5318 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5319 && DECL_NAME (constructor_fields) == 0)
5320 constructor_fields = TREE_CHAIN (constructor_fields);
5321
5322 constructor_unfilled_fields = constructor_fields;
5323 constructor_bit_index = bitsize_zero_node;
5324 }
5325 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5326 {
5327 /* Vectors are like simple fixed-size arrays. */
5328 constructor_max_index =
5329 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5330 constructor_index = convert (bitsizetype, integer_zero_node);
5331 constructor_unfilled_index = constructor_index;
5332 }
5333 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5334 {
5335 if (TYPE_DOMAIN (constructor_type))
5336 {
5337 constructor_max_index
5338 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5339
5340 /* Detect non-empty initializations of zero-length arrays. */
5341 if (constructor_max_index == NULL_TREE
5342 && TYPE_SIZE (constructor_type))
5343 constructor_max_index = build_int_cst (NULL_TREE, -1);
5344
5345 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5346 to initialize VLAs will cause a proper error; avoid tree
5347 checking errors as well by setting a safe value. */
5348 if (constructor_max_index
5349 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5350 constructor_max_index = build_int_cst (NULL_TREE, -1);
5351
5352 constructor_index
5353 = convert (bitsizetype,
5354 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5355 }
5356 else
5357 constructor_index = bitsize_zero_node;
5358
5359 constructor_unfilled_index = constructor_index;
5360 if (value && TREE_CODE (value) == STRING_CST)
5361 {
5362 /* We need to split the char/wchar array into individual
5363 characters, so that we don't have to special case it
5364 everywhere. */
5365 set_nonincremental_init_from_string (value);
5366 }
5367 }
5368 else
5369 {
5370 if (constructor_type != error_mark_node)
5371 warning_init ("braces around scalar initializer");
5372 constructor_fields = constructor_type;
5373 constructor_unfilled_fields = constructor_type;
5374 }
5375 }
5376
5377 /* At the end of an implicit or explicit brace level,
5378 finish up that level of constructor. If a single expression
5379 with redundant braces initialized that level, return the
5380 c_expr structure for that expression. Otherwise, the original_code
5381 element is set to ERROR_MARK.
5382 If we were outputting the elements as they are read, return 0 as the value
5383 from inner levels (process_init_element ignores that),
5384 but return error_mark_node as the value from the outermost level
5385 (that's what we want to put in DECL_INITIAL).
5386 Otherwise, return a CONSTRUCTOR expression as the value. */
5387
5388 struct c_expr
5389 pop_init_level (int implicit)
5390 {
5391 struct constructor_stack *p;
5392 struct c_expr ret;
5393 ret.value = 0;
5394 ret.original_code = ERROR_MARK;
5395
5396 if (implicit == 0)
5397 {
5398 /* When we come to an explicit close brace,
5399 pop any inner levels that didn't have explicit braces. */
5400 while (constructor_stack->implicit)
5401 process_init_element (pop_init_level (1));
5402
5403 gcc_assert (!constructor_range_stack);
5404 }
5405
5406 /* Now output all pending elements. */
5407 constructor_incremental = 1;
5408 output_pending_init_elements (1);
5409
5410 p = constructor_stack;
5411
5412 /* Error for initializing a flexible array member, or a zero-length
5413 array member in an inappropriate context. */
5414 if (constructor_type && constructor_fields
5415 && TREE_CODE (constructor_type) == ARRAY_TYPE
5416 && TYPE_DOMAIN (constructor_type)
5417 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5418 {
5419 /* Silently discard empty initializations. The parser will
5420 already have pedwarned for empty brackets. */
5421 if (integer_zerop (constructor_unfilled_index))
5422 constructor_type = NULL_TREE;
5423 else
5424 {
5425 gcc_assert (!TYPE_SIZE (constructor_type));
5426
5427 if (constructor_depth > 2)
5428 error_init ("initialization of flexible array member in a nested context");
5429 else if (pedantic)
5430 pedwarn_init ("initialization of a flexible array member");
5431
5432 /* We have already issued an error message for the existence
5433 of a flexible array member not at the end of the structure.
5434 Discard the initializer so that we do not die later. */
5435 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5436 constructor_type = NULL_TREE;
5437 }
5438 }
5439
5440 /* Warn when some struct elements are implicitly initialized to zero. */
5441 if (warn_missing_field_initializers
5442 && constructor_type
5443 && TREE_CODE (constructor_type) == RECORD_TYPE
5444 && constructor_unfilled_fields)
5445 {
5446 /* Do not warn for flexible array members or zero-length arrays. */
5447 while (constructor_unfilled_fields
5448 && (!DECL_SIZE (constructor_unfilled_fields)
5449 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5450 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5451
5452 /* Do not warn if this level of the initializer uses member
5453 designators; it is likely to be deliberate. */
5454 if (constructor_unfilled_fields && !constructor_designated)
5455 {
5456 push_member_name (constructor_unfilled_fields);
5457 warning_init ("missing initializer");
5458 RESTORE_SPELLING_DEPTH (constructor_depth);
5459 }
5460 }
5461
5462 /* Pad out the end of the structure. */
5463 if (p->replacement_value.value)
5464 /* If this closes a superfluous brace pair,
5465 just pass out the element between them. */
5466 ret = p->replacement_value;
5467 else if (constructor_type == 0)
5468 ;
5469 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5470 && TREE_CODE (constructor_type) != UNION_TYPE
5471 && TREE_CODE (constructor_type) != ARRAY_TYPE
5472 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5473 {
5474 /* A nonincremental scalar initializer--just return
5475 the element, after verifying there is just one. */
5476 if (VEC_empty (constructor_elt,constructor_elements))
5477 {
5478 if (!constructor_erroneous)
5479 error_init ("empty scalar initializer");
5480 ret.value = error_mark_node;
5481 }
5482 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5483 {
5484 error_init ("extra elements in scalar initializer");
5485 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5486 }
5487 else
5488 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5489 }
5490 else
5491 {
5492 if (constructor_erroneous)
5493 ret.value = error_mark_node;
5494 else
5495 {
5496 ret.value = build_constructor (constructor_type,
5497 constructor_elements);
5498 if (constructor_constant)
5499 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1;
5500 if (constructor_constant && constructor_simple)
5501 TREE_STATIC (ret.value) = 1;
5502 }
5503 }
5504
5505 constructor_type = p->type;
5506 constructor_fields = p->fields;
5507 constructor_index = p->index;
5508 constructor_max_index = p->max_index;
5509 constructor_unfilled_index = p->unfilled_index;
5510 constructor_unfilled_fields = p->unfilled_fields;
5511 constructor_bit_index = p->bit_index;
5512 constructor_elements = p->elements;
5513 constructor_constant = p->constant;
5514 constructor_simple = p->simple;
5515 constructor_erroneous = p->erroneous;
5516 constructor_incremental = p->incremental;
5517 constructor_designated = p->designated;
5518 constructor_pending_elts = p->pending_elts;
5519 constructor_depth = p->depth;
5520 if (!p->implicit)
5521 constructor_range_stack = p->range_stack;
5522 RESTORE_SPELLING_DEPTH (constructor_depth);
5523
5524 constructor_stack = p->next;
5525 free (p);
5526
5527 if (ret.value == 0 && constructor_stack == 0)
5528 ret.value = error_mark_node;
5529 return ret;
5530 }
5531
5532 /* Common handling for both array range and field name designators.
5533 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5534
5535 static int
5536 set_designator (int array)
5537 {
5538 tree subtype;
5539 enum tree_code subcode;
5540
5541 /* Don't die if an entire brace-pair level is superfluous
5542 in the containing level. */
5543 if (constructor_type == 0)
5544 return 1;
5545
5546 /* If there were errors in this designator list already, bail out
5547 silently. */
5548 if (designator_erroneous)
5549 return 1;
5550
5551 if (!designator_depth)
5552 {
5553 gcc_assert (!constructor_range_stack);
5554
5555 /* Designator list starts at the level of closest explicit
5556 braces. */
5557 while (constructor_stack->implicit)
5558 process_init_element (pop_init_level (1));
5559 constructor_designated = 1;
5560 return 0;
5561 }
5562
5563 switch (TREE_CODE (constructor_type))
5564 {
5565 case RECORD_TYPE:
5566 case UNION_TYPE:
5567 subtype = TREE_TYPE (constructor_fields);
5568 if (subtype != error_mark_node)
5569 subtype = TYPE_MAIN_VARIANT (subtype);
5570 break;
5571 case ARRAY_TYPE:
5572 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5573 break;
5574 default:
5575 gcc_unreachable ();
5576 }
5577
5578 subcode = TREE_CODE (subtype);
5579 if (array && subcode != ARRAY_TYPE)
5580 {
5581 error_init ("array index in non-array initializer");
5582 return 1;
5583 }
5584 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5585 {
5586 error_init ("field name not in record or union initializer");
5587 return 1;
5588 }
5589
5590 constructor_designated = 1;
5591 push_init_level (2);
5592 return 0;
5593 }
5594
5595 /* If there are range designators in designator list, push a new designator
5596 to constructor_range_stack. RANGE_END is end of such stack range or
5597 NULL_TREE if there is no range designator at this level. */
5598
5599 static void
5600 push_range_stack (tree range_end)
5601 {
5602 struct constructor_range_stack *p;
5603
5604 p = GGC_NEW (struct constructor_range_stack);
5605 p->prev = constructor_range_stack;
5606 p->next = 0;
5607 p->fields = constructor_fields;
5608 p->range_start = constructor_index;
5609 p->index = constructor_index;
5610 p->stack = constructor_stack;
5611 p->range_end = range_end;
5612 if (constructor_range_stack)
5613 constructor_range_stack->next = p;
5614 constructor_range_stack = p;
5615 }
5616
5617 /* Within an array initializer, specify the next index to be initialized.
5618 FIRST is that index. If LAST is nonzero, then initialize a range
5619 of indices, running from FIRST through LAST. */
5620
5621 void
5622 set_init_index (tree first, tree last)
5623 {
5624 if (set_designator (1))
5625 return;
5626
5627 designator_erroneous = 1;
5628
5629 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5630 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5631 {
5632 error_init ("array index in initializer not of integer type");
5633 return;
5634 }
5635
5636 if (TREE_CODE (first) != INTEGER_CST)
5637 error_init ("nonconstant array index in initializer");
5638 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5639 error_init ("nonconstant array index in initializer");
5640 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5641 error_init ("array index in non-array initializer");
5642 else if (tree_int_cst_sgn (first) == -1)
5643 error_init ("array index in initializer exceeds array bounds");
5644 else if (constructor_max_index
5645 && tree_int_cst_lt (constructor_max_index, first))
5646 error_init ("array index in initializer exceeds array bounds");
5647 else
5648 {
5649 constructor_index = convert (bitsizetype, first);
5650
5651 if (last)
5652 {
5653 if (tree_int_cst_equal (first, last))
5654 last = 0;
5655 else if (tree_int_cst_lt (last, first))
5656 {
5657 error_init ("empty index range in initializer");
5658 last = 0;
5659 }
5660 else
5661 {
5662 last = convert (bitsizetype, last);
5663 if (constructor_max_index != 0
5664 && tree_int_cst_lt (constructor_max_index, last))
5665 {
5666 error_init ("array index range in initializer exceeds array bounds");
5667 last = 0;
5668 }
5669 }
5670 }
5671
5672 designator_depth++;
5673 designator_erroneous = 0;
5674 if (constructor_range_stack || last)
5675 push_range_stack (last);
5676 }
5677 }
5678
5679 /* Within a struct initializer, specify the next field to be initialized. */
5680
5681 void
5682 set_init_label (tree fieldname)
5683 {
5684 tree tail;
5685
5686 if (set_designator (0))
5687 return;
5688
5689 designator_erroneous = 1;
5690
5691 if (TREE_CODE (constructor_type) != RECORD_TYPE
5692 && TREE_CODE (constructor_type) != UNION_TYPE)
5693 {
5694 error_init ("field name not in record or union initializer");
5695 return;
5696 }
5697
5698 for (tail = TYPE_FIELDS (constructor_type); tail;
5699 tail = TREE_CHAIN (tail))
5700 {
5701 if (DECL_NAME (tail) == fieldname)
5702 break;
5703 }
5704
5705 if (tail == 0)
5706 error ("unknown field %qE specified in initializer", fieldname);
5707 else
5708 {
5709 constructor_fields = tail;
5710 designator_depth++;
5711 designator_erroneous = 0;
5712 if (constructor_range_stack)
5713 push_range_stack (NULL_TREE);
5714 }
5715 }
5716 \f
5717 /* Add a new initializer to the tree of pending initializers. PURPOSE
5718 identifies the initializer, either array index or field in a structure.
5719 VALUE is the value of that index or field. */
5720
5721 static void
5722 add_pending_init (tree purpose, tree value)
5723 {
5724 struct init_node *p, **q, *r;
5725
5726 q = &constructor_pending_elts;
5727 p = 0;
5728
5729 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5730 {
5731 while (*q != 0)
5732 {
5733 p = *q;
5734 if (tree_int_cst_lt (purpose, p->purpose))
5735 q = &p->left;
5736 else if (tree_int_cst_lt (p->purpose, purpose))
5737 q = &p->right;
5738 else
5739 {
5740 if (TREE_SIDE_EFFECTS (p->value))
5741 warning_init ("initialized field with side-effects overwritten");
5742 else if (warn_override_init)
5743 warning_init ("initialized field overwritten");
5744 p->value = value;
5745 return;
5746 }
5747 }
5748 }
5749 else
5750 {
5751 tree bitpos;
5752
5753 bitpos = bit_position (purpose);
5754 while (*q != NULL)
5755 {
5756 p = *q;
5757 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5758 q = &p->left;
5759 else if (p->purpose != purpose)
5760 q = &p->right;
5761 else
5762 {
5763 if (TREE_SIDE_EFFECTS (p->value))
5764 warning_init ("initialized field with side-effects overwritten");
5765 else if (warn_override_init)
5766 warning_init ("initialized field overwritten");
5767 p->value = value;
5768 return;
5769 }
5770 }
5771 }
5772
5773 r = GGC_NEW (struct init_node);
5774 r->purpose = purpose;
5775 r->value = value;
5776
5777 *q = r;
5778 r->parent = p;
5779 r->left = 0;
5780 r->right = 0;
5781 r->balance = 0;
5782
5783 while (p)
5784 {
5785 struct init_node *s;
5786
5787 if (r == p->left)
5788 {
5789 if (p->balance == 0)
5790 p->balance = -1;
5791 else if (p->balance < 0)
5792 {
5793 if (r->balance < 0)
5794 {
5795 /* L rotation. */
5796 p->left = r->right;
5797 if (p->left)
5798 p->left->parent = p;
5799 r->right = p;
5800
5801 p->balance = 0;
5802 r->balance = 0;
5803
5804 s = p->parent;
5805 p->parent = r;
5806 r->parent = s;
5807 if (s)
5808 {
5809 if (s->left == p)
5810 s->left = r;
5811 else
5812 s->right = r;
5813 }
5814 else
5815 constructor_pending_elts = r;
5816 }
5817 else
5818 {
5819 /* LR rotation. */
5820 struct init_node *t = r->right;
5821
5822 r->right = t->left;
5823 if (r->right)
5824 r->right->parent = r;
5825 t->left = r;
5826
5827 p->left = t->right;
5828 if (p->left)
5829 p->left->parent = p;
5830 t->right = p;
5831
5832 p->balance = t->balance < 0;
5833 r->balance = -(t->balance > 0);
5834 t->balance = 0;
5835
5836 s = p->parent;
5837 p->parent = t;
5838 r->parent = t;
5839 t->parent = s;
5840 if (s)
5841 {
5842 if (s->left == p)
5843 s->left = t;
5844 else
5845 s->right = t;
5846 }
5847 else
5848 constructor_pending_elts = t;
5849 }
5850 break;
5851 }
5852 else
5853 {
5854 /* p->balance == +1; growth of left side balances the node. */
5855 p->balance = 0;
5856 break;
5857 }
5858 }
5859 else /* r == p->right */
5860 {
5861 if (p->balance == 0)
5862 /* Growth propagation from right side. */
5863 p->balance++;
5864 else if (p->balance > 0)
5865 {
5866 if (r->balance > 0)
5867 {
5868 /* R rotation. */
5869 p->right = r->left;
5870 if (p->right)
5871 p->right->parent = p;
5872 r->left = p;
5873
5874 p->balance = 0;
5875 r->balance = 0;
5876
5877 s = p->parent;
5878 p->parent = r;
5879 r->parent = s;
5880 if (s)
5881 {
5882 if (s->left == p)
5883 s->left = r;
5884 else
5885 s->right = r;
5886 }
5887 else
5888 constructor_pending_elts = r;
5889 }
5890 else /* r->balance == -1 */
5891 {
5892 /* RL rotation */
5893 struct init_node *t = r->left;
5894
5895 r->left = t->right;
5896 if (r->left)
5897 r->left->parent = r;
5898 t->right = r;
5899
5900 p->right = t->left;
5901 if (p->right)
5902 p->right->parent = p;
5903 t->left = p;
5904
5905 r->balance = (t->balance < 0);
5906 p->balance = -(t->balance > 0);
5907 t->balance = 0;
5908
5909 s = p->parent;
5910 p->parent = t;
5911 r->parent = t;
5912 t->parent = s;
5913 if (s)
5914 {
5915 if (s->left == p)
5916 s->left = t;
5917 else
5918 s->right = t;
5919 }
5920 else
5921 constructor_pending_elts = t;
5922 }
5923 break;
5924 }
5925 else
5926 {
5927 /* p->balance == -1; growth of right side balances the node. */
5928 p->balance = 0;
5929 break;
5930 }
5931 }
5932
5933 r = p;
5934 p = p->parent;
5935 }
5936 }
5937
5938 /* Build AVL tree from a sorted chain. */
5939
5940 static void
5941 set_nonincremental_init (void)
5942 {
5943 unsigned HOST_WIDE_INT ix;
5944 tree index, value;
5945
5946 if (TREE_CODE (constructor_type) != RECORD_TYPE
5947 && TREE_CODE (constructor_type) != ARRAY_TYPE)
5948 return;
5949
5950 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
5951 add_pending_init (index, value);
5952 constructor_elements = 0;
5953 if (TREE_CODE (constructor_type) == RECORD_TYPE)
5954 {
5955 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
5956 /* Skip any nameless bit fields at the beginning. */
5957 while (constructor_unfilled_fields != 0
5958 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
5959 && DECL_NAME (constructor_unfilled_fields) == 0)
5960 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5961
5962 }
5963 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5964 {
5965 if (TYPE_DOMAIN (constructor_type))
5966 constructor_unfilled_index
5967 = convert (bitsizetype,
5968 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5969 else
5970 constructor_unfilled_index = bitsize_zero_node;
5971 }
5972 constructor_incremental = 0;
5973 }
5974
5975 /* Build AVL tree from a string constant. */
5976
5977 static void
5978 set_nonincremental_init_from_string (tree str)
5979 {
5980 tree value, purpose, type;
5981 HOST_WIDE_INT val[2];
5982 const char *p, *end;
5983 int byte, wchar_bytes, charwidth, bitpos;
5984
5985 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
5986
5987 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5988 == TYPE_PRECISION (char_type_node))
5989 wchar_bytes = 1;
5990 else
5991 {
5992 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5993 == TYPE_PRECISION (wchar_type_node));
5994 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
5995 }
5996 charwidth = TYPE_PRECISION (char_type_node);
5997 type = TREE_TYPE (constructor_type);
5998 p = TREE_STRING_POINTER (str);
5999 end = p + TREE_STRING_LENGTH (str);
6000
6001 for (purpose = bitsize_zero_node;
6002 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6003 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6004 {
6005 if (wchar_bytes == 1)
6006 {
6007 val[1] = (unsigned char) *p++;
6008 val[0] = 0;
6009 }
6010 else
6011 {
6012 val[0] = 0;
6013 val[1] = 0;
6014 for (byte = 0; byte < wchar_bytes; byte++)
6015 {
6016 if (BYTES_BIG_ENDIAN)
6017 bitpos = (wchar_bytes - byte - 1) * charwidth;
6018 else
6019 bitpos = byte * charwidth;
6020 val[bitpos < HOST_BITS_PER_WIDE_INT]
6021 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6022 << (bitpos % HOST_BITS_PER_WIDE_INT);
6023 }
6024 }
6025
6026 if (!TYPE_UNSIGNED (type))
6027 {
6028 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6029 if (bitpos < HOST_BITS_PER_WIDE_INT)
6030 {
6031 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6032 {
6033 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6034 val[0] = -1;
6035 }
6036 }
6037 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6038 {
6039 if (val[1] < 0)
6040 val[0] = -1;
6041 }
6042 else if (val[0] & (((HOST_WIDE_INT) 1)
6043 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6044 val[0] |= ((HOST_WIDE_INT) -1)
6045 << (bitpos - HOST_BITS_PER_WIDE_INT);
6046 }
6047
6048 value = build_int_cst_wide (type, val[1], val[0]);
6049 add_pending_init (purpose, value);
6050 }
6051
6052 constructor_incremental = 0;
6053 }
6054
6055 /* Return value of FIELD in pending initializer or zero if the field was
6056 not initialized yet. */
6057
6058 static tree
6059 find_init_member (tree field)
6060 {
6061 struct init_node *p;
6062
6063 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6064 {
6065 if (constructor_incremental
6066 && tree_int_cst_lt (field, constructor_unfilled_index))
6067 set_nonincremental_init ();
6068
6069 p = constructor_pending_elts;
6070 while (p)
6071 {
6072 if (tree_int_cst_lt (field, p->purpose))
6073 p = p->left;
6074 else if (tree_int_cst_lt (p->purpose, field))
6075 p = p->right;
6076 else
6077 return p->value;
6078 }
6079 }
6080 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6081 {
6082 tree bitpos = bit_position (field);
6083
6084 if (constructor_incremental
6085 && (!constructor_unfilled_fields
6086 || tree_int_cst_lt (bitpos,
6087 bit_position (constructor_unfilled_fields))))
6088 set_nonincremental_init ();
6089
6090 p = constructor_pending_elts;
6091 while (p)
6092 {
6093 if (field == p->purpose)
6094 return p->value;
6095 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6096 p = p->left;
6097 else
6098 p = p->right;
6099 }
6100 }
6101 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6102 {
6103 if (!VEC_empty (constructor_elt, constructor_elements)
6104 && (VEC_last (constructor_elt, constructor_elements)->index
6105 == field))
6106 return VEC_last (constructor_elt, constructor_elements)->value;
6107 }
6108 return 0;
6109 }
6110
6111 /* "Output" the next constructor element.
6112 At top level, really output it to assembler code now.
6113 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6114 TYPE is the data type that the containing data type wants here.
6115 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6116 If VALUE is a string constant, STRICT_STRING is true if it is
6117 unparenthesized or we should not warn here for it being parenthesized.
6118 For other types of VALUE, STRICT_STRING is not used.
6119
6120 PENDING if non-nil means output pending elements that belong
6121 right after this element. (PENDING is normally 1;
6122 it is 0 while outputting pending elements, to avoid recursion.) */
6123
6124 static void
6125 output_init_element (tree value, bool strict_string, tree type, tree field,
6126 int pending)
6127 {
6128 constructor_elt *celt;
6129
6130 if (type == error_mark_node || value == error_mark_node)
6131 {
6132 constructor_erroneous = 1;
6133 return;
6134 }
6135 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6136 && (TREE_CODE (value) == STRING_CST
6137 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6138 && !(TREE_CODE (value) == STRING_CST
6139 && TREE_CODE (type) == ARRAY_TYPE
6140 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6141 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6142 TYPE_MAIN_VARIANT (type)))
6143 value = array_to_pointer_conversion (value);
6144
6145 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6146 && require_constant_value && !flag_isoc99 && pending)
6147 {
6148 /* As an extension, allow initializing objects with static storage
6149 duration with compound literals (which are then treated just as
6150 the brace enclosed list they contain). */
6151 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6152 value = DECL_INITIAL (decl);
6153 }
6154
6155 if (value == error_mark_node)
6156 constructor_erroneous = 1;
6157 else if (!TREE_CONSTANT (value))
6158 constructor_constant = 0;
6159 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6160 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6161 || TREE_CODE (constructor_type) == UNION_TYPE)
6162 && DECL_C_BIT_FIELD (field)
6163 && TREE_CODE (value) != INTEGER_CST))
6164 constructor_simple = 0;
6165
6166 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6167 {
6168 if (require_constant_value)
6169 {
6170 error_init ("initializer element is not constant");
6171 value = error_mark_node;
6172 }
6173 else if (require_constant_elements)
6174 pedwarn ("initializer element is not computable at load time");
6175 }
6176
6177 /* If this field is empty (and not at the end of structure),
6178 don't do anything other than checking the initializer. */
6179 if (field
6180 && (TREE_TYPE (field) == error_mark_node
6181 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6182 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6183 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6184 || TREE_CHAIN (field)))))
6185 return;
6186
6187 value = digest_init (type, value, strict_string, require_constant_value);
6188 if (value == error_mark_node)
6189 {
6190 constructor_erroneous = 1;
6191 return;
6192 }
6193
6194 /* If this element doesn't come next in sequence,
6195 put it on constructor_pending_elts. */
6196 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6197 && (!constructor_incremental
6198 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6199 {
6200 if (constructor_incremental
6201 && tree_int_cst_lt (field, constructor_unfilled_index))
6202 set_nonincremental_init ();
6203
6204 add_pending_init (field, value);
6205 return;
6206 }
6207 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6208 && (!constructor_incremental
6209 || field != constructor_unfilled_fields))
6210 {
6211 /* We do this for records but not for unions. In a union,
6212 no matter which field is specified, it can be initialized
6213 right away since it starts at the beginning of the union. */
6214 if (constructor_incremental)
6215 {
6216 if (!constructor_unfilled_fields)
6217 set_nonincremental_init ();
6218 else
6219 {
6220 tree bitpos, unfillpos;
6221
6222 bitpos = bit_position (field);
6223 unfillpos = bit_position (constructor_unfilled_fields);
6224
6225 if (tree_int_cst_lt (bitpos, unfillpos))
6226 set_nonincremental_init ();
6227 }
6228 }
6229
6230 add_pending_init (field, value);
6231 return;
6232 }
6233 else if (TREE_CODE (constructor_type) == UNION_TYPE
6234 && !VEC_empty (constructor_elt, constructor_elements))
6235 {
6236 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6237 constructor_elements)->value))
6238 warning_init ("initialized field with side-effects overwritten");
6239 else if (warn_override_init)
6240 warning_init ("initialized field overwritten");
6241
6242 /* We can have just one union field set. */
6243 constructor_elements = 0;
6244 }
6245
6246 /* Otherwise, output this element either to
6247 constructor_elements or to the assembler file. */
6248
6249 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6250 celt->index = field;
6251 celt->value = value;
6252
6253 /* Advance the variable that indicates sequential elements output. */
6254 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6255 constructor_unfilled_index
6256 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6257 bitsize_one_node);
6258 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6259 {
6260 constructor_unfilled_fields
6261 = TREE_CHAIN (constructor_unfilled_fields);
6262
6263 /* Skip any nameless bit fields. */
6264 while (constructor_unfilled_fields != 0
6265 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6266 && DECL_NAME (constructor_unfilled_fields) == 0)
6267 constructor_unfilled_fields =
6268 TREE_CHAIN (constructor_unfilled_fields);
6269 }
6270 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6271 constructor_unfilled_fields = 0;
6272
6273 /* Now output any pending elements which have become next. */
6274 if (pending)
6275 output_pending_init_elements (0);
6276 }
6277
6278 /* Output any pending elements which have become next.
6279 As we output elements, constructor_unfilled_{fields,index}
6280 advances, which may cause other elements to become next;
6281 if so, they too are output.
6282
6283 If ALL is 0, we return when there are
6284 no more pending elements to output now.
6285
6286 If ALL is 1, we output space as necessary so that
6287 we can output all the pending elements. */
6288
6289 static void
6290 output_pending_init_elements (int all)
6291 {
6292 struct init_node *elt = constructor_pending_elts;
6293 tree next;
6294
6295 retry:
6296
6297 /* Look through the whole pending tree.
6298 If we find an element that should be output now,
6299 output it. Otherwise, set NEXT to the element
6300 that comes first among those still pending. */
6301
6302 next = 0;
6303 while (elt)
6304 {
6305 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6306 {
6307 if (tree_int_cst_equal (elt->purpose,
6308 constructor_unfilled_index))
6309 output_init_element (elt->value, true,
6310 TREE_TYPE (constructor_type),
6311 constructor_unfilled_index, 0);
6312 else if (tree_int_cst_lt (constructor_unfilled_index,
6313 elt->purpose))
6314 {
6315 /* Advance to the next smaller node. */
6316 if (elt->left)
6317 elt = elt->left;
6318 else
6319 {
6320 /* We have reached the smallest node bigger than the
6321 current unfilled index. Fill the space first. */
6322 next = elt->purpose;
6323 break;
6324 }
6325 }
6326 else
6327 {
6328 /* Advance to the next bigger node. */
6329 if (elt->right)
6330 elt = elt->right;
6331 else
6332 {
6333 /* We have reached the biggest node in a subtree. Find
6334 the parent of it, which is the next bigger node. */
6335 while (elt->parent && elt->parent->right == elt)
6336 elt = elt->parent;
6337 elt = elt->parent;
6338 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6339 elt->purpose))
6340 {
6341 next = elt->purpose;
6342 break;
6343 }
6344 }
6345 }
6346 }
6347 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6348 || TREE_CODE (constructor_type) == UNION_TYPE)
6349 {
6350 tree ctor_unfilled_bitpos, elt_bitpos;
6351
6352 /* If the current record is complete we are done. */
6353 if (constructor_unfilled_fields == 0)
6354 break;
6355
6356 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6357 elt_bitpos = bit_position (elt->purpose);
6358 /* We can't compare fields here because there might be empty
6359 fields in between. */
6360 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6361 {
6362 constructor_unfilled_fields = elt->purpose;
6363 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6364 elt->purpose, 0);
6365 }
6366 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6367 {
6368 /* Advance to the next smaller node. */
6369 if (elt->left)
6370 elt = elt->left;
6371 else
6372 {
6373 /* We have reached the smallest node bigger than the
6374 current unfilled field. Fill the space first. */
6375 next = elt->purpose;
6376 break;
6377 }
6378 }
6379 else
6380 {
6381 /* Advance to the next bigger node. */
6382 if (elt->right)
6383 elt = elt->right;
6384 else
6385 {
6386 /* We have reached the biggest node in a subtree. Find
6387 the parent of it, which is the next bigger node. */
6388 while (elt->parent && elt->parent->right == elt)
6389 elt = elt->parent;
6390 elt = elt->parent;
6391 if (elt
6392 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6393 bit_position (elt->purpose))))
6394 {
6395 next = elt->purpose;
6396 break;
6397 }
6398 }
6399 }
6400 }
6401 }
6402
6403 /* Ordinarily return, but not if we want to output all
6404 and there are elements left. */
6405 if (!(all && next != 0))
6406 return;
6407
6408 /* If it's not incremental, just skip over the gap, so that after
6409 jumping to retry we will output the next successive element. */
6410 if (TREE_CODE (constructor_type) == RECORD_TYPE
6411 || TREE_CODE (constructor_type) == UNION_TYPE)
6412 constructor_unfilled_fields = next;
6413 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6414 constructor_unfilled_index = next;
6415
6416 /* ELT now points to the node in the pending tree with the next
6417 initializer to output. */
6418 goto retry;
6419 }
6420 \f
6421 /* Add one non-braced element to the current constructor level.
6422 This adjusts the current position within the constructor's type.
6423 This may also start or terminate implicit levels
6424 to handle a partly-braced initializer.
6425
6426 Once this has found the correct level for the new element,
6427 it calls output_init_element. */
6428
6429 void
6430 process_init_element (struct c_expr value)
6431 {
6432 tree orig_value = value.value;
6433 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6434 bool strict_string = value.original_code == STRING_CST;
6435
6436 designator_depth = 0;
6437 designator_erroneous = 0;
6438
6439 /* Handle superfluous braces around string cst as in
6440 char x[] = {"foo"}; */
6441 if (string_flag
6442 && constructor_type
6443 && TREE_CODE (constructor_type) == ARRAY_TYPE
6444 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6445 && integer_zerop (constructor_unfilled_index))
6446 {
6447 if (constructor_stack->replacement_value.value)
6448 error_init ("excess elements in char array initializer");
6449 constructor_stack->replacement_value = value;
6450 return;
6451 }
6452
6453 if (constructor_stack->replacement_value.value != 0)
6454 {
6455 error_init ("excess elements in struct initializer");
6456 return;
6457 }
6458
6459 /* Ignore elements of a brace group if it is entirely superfluous
6460 and has already been diagnosed. */
6461 if (constructor_type == 0)
6462 return;
6463
6464 /* If we've exhausted any levels that didn't have braces,
6465 pop them now. */
6466 while (constructor_stack->implicit)
6467 {
6468 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6469 || TREE_CODE (constructor_type) == UNION_TYPE)
6470 && constructor_fields == 0)
6471 process_init_element (pop_init_level (1));
6472 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6473 && (constructor_max_index == 0
6474 || tree_int_cst_lt (constructor_max_index,
6475 constructor_index)))
6476 process_init_element (pop_init_level (1));
6477 else
6478 break;
6479 }
6480
6481 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6482 if (constructor_range_stack)
6483 {
6484 /* If value is a compound literal and we'll be just using its
6485 content, don't put it into a SAVE_EXPR. */
6486 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6487 || !require_constant_value
6488 || flag_isoc99)
6489 value.value = save_expr (value.value);
6490 }
6491
6492 while (1)
6493 {
6494 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6495 {
6496 tree fieldtype;
6497 enum tree_code fieldcode;
6498
6499 if (constructor_fields == 0)
6500 {
6501 pedwarn_init ("excess elements in struct initializer");
6502 break;
6503 }
6504
6505 fieldtype = TREE_TYPE (constructor_fields);
6506 if (fieldtype != error_mark_node)
6507 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6508 fieldcode = TREE_CODE (fieldtype);
6509
6510 /* Error for non-static initialization of a flexible array member. */
6511 if (fieldcode == ARRAY_TYPE
6512 && !require_constant_value
6513 && TYPE_SIZE (fieldtype) == NULL_TREE
6514 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6515 {
6516 error_init ("non-static initialization of a flexible array member");
6517 break;
6518 }
6519
6520 /* Accept a string constant to initialize a subarray. */
6521 if (value.value != 0
6522 && fieldcode == ARRAY_TYPE
6523 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6524 && string_flag)
6525 value.value = orig_value;
6526 /* Otherwise, if we have come to a subaggregate,
6527 and we don't have an element of its type, push into it. */
6528 else if (value.value != 0
6529 && value.value != error_mark_node
6530 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6531 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6532 || fieldcode == UNION_TYPE))
6533 {
6534 push_init_level (1);
6535 continue;
6536 }
6537
6538 if (value.value)
6539 {
6540 push_member_name (constructor_fields);
6541 output_init_element (value.value, strict_string,
6542 fieldtype, constructor_fields, 1);
6543 RESTORE_SPELLING_DEPTH (constructor_depth);
6544 }
6545 else
6546 /* Do the bookkeeping for an element that was
6547 directly output as a constructor. */
6548 {
6549 /* For a record, keep track of end position of last field. */
6550 if (DECL_SIZE (constructor_fields))
6551 constructor_bit_index
6552 = size_binop (PLUS_EXPR,
6553 bit_position (constructor_fields),
6554 DECL_SIZE (constructor_fields));
6555
6556 /* If the current field was the first one not yet written out,
6557 it isn't now, so update. */
6558 if (constructor_unfilled_fields == constructor_fields)
6559 {
6560 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6561 /* Skip any nameless bit fields. */
6562 while (constructor_unfilled_fields != 0
6563 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6564 && DECL_NAME (constructor_unfilled_fields) == 0)
6565 constructor_unfilled_fields =
6566 TREE_CHAIN (constructor_unfilled_fields);
6567 }
6568 }
6569
6570 constructor_fields = TREE_CHAIN (constructor_fields);
6571 /* Skip any nameless bit fields at the beginning. */
6572 while (constructor_fields != 0
6573 && DECL_C_BIT_FIELD (constructor_fields)
6574 && DECL_NAME (constructor_fields) == 0)
6575 constructor_fields = TREE_CHAIN (constructor_fields);
6576 }
6577 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6578 {
6579 tree fieldtype;
6580 enum tree_code fieldcode;
6581
6582 if (constructor_fields == 0)
6583 {
6584 pedwarn_init ("excess elements in union initializer");
6585 break;
6586 }
6587
6588 fieldtype = TREE_TYPE (constructor_fields);
6589 if (fieldtype != error_mark_node)
6590 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6591 fieldcode = TREE_CODE (fieldtype);
6592
6593 /* Warn that traditional C rejects initialization of unions.
6594 We skip the warning if the value is zero. This is done
6595 under the assumption that the zero initializer in user
6596 code appears conditioned on e.g. __STDC__ to avoid
6597 "missing initializer" warnings and relies on default
6598 initialization to zero in the traditional C case.
6599 We also skip the warning if the initializer is designated,
6600 again on the assumption that this must be conditional on
6601 __STDC__ anyway (and we've already complained about the
6602 member-designator already). */
6603 if (!in_system_header && !constructor_designated
6604 && !(value.value && (integer_zerop (value.value)
6605 || real_zerop (value.value))))
6606 warning (OPT_Wtraditional, "traditional C rejects initialization "
6607 "of unions");
6608
6609 /* Accept a string constant to initialize a subarray. */
6610 if (value.value != 0
6611 && fieldcode == ARRAY_TYPE
6612 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6613 && string_flag)
6614 value.value = orig_value;
6615 /* Otherwise, if we have come to a subaggregate,
6616 and we don't have an element of its type, push into it. */
6617 else if (value.value != 0
6618 && value.value != error_mark_node
6619 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6620 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6621 || fieldcode == UNION_TYPE))
6622 {
6623 push_init_level (1);
6624 continue;
6625 }
6626
6627 if (value.value)
6628 {
6629 push_member_name (constructor_fields);
6630 output_init_element (value.value, strict_string,
6631 fieldtype, constructor_fields, 1);
6632 RESTORE_SPELLING_DEPTH (constructor_depth);
6633 }
6634 else
6635 /* Do the bookkeeping for an element that was
6636 directly output as a constructor. */
6637 {
6638 constructor_bit_index = DECL_SIZE (constructor_fields);
6639 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6640 }
6641
6642 constructor_fields = 0;
6643 }
6644 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6645 {
6646 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6647 enum tree_code eltcode = TREE_CODE (elttype);
6648
6649 /* Accept a string constant to initialize a subarray. */
6650 if (value.value != 0
6651 && eltcode == ARRAY_TYPE
6652 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6653 && string_flag)
6654 value.value = orig_value;
6655 /* Otherwise, if we have come to a subaggregate,
6656 and we don't have an element of its type, push into it. */
6657 else if (value.value != 0
6658 && value.value != error_mark_node
6659 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6660 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6661 || eltcode == UNION_TYPE))
6662 {
6663 push_init_level (1);
6664 continue;
6665 }
6666
6667 if (constructor_max_index != 0
6668 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6669 || integer_all_onesp (constructor_max_index)))
6670 {
6671 pedwarn_init ("excess elements in array initializer");
6672 break;
6673 }
6674
6675 /* Now output the actual element. */
6676 if (value.value)
6677 {
6678 push_array_bounds (tree_low_cst (constructor_index, 1));
6679 output_init_element (value.value, strict_string,
6680 elttype, constructor_index, 1);
6681 RESTORE_SPELLING_DEPTH (constructor_depth);
6682 }
6683
6684 constructor_index
6685 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6686
6687 if (!value.value)
6688 /* If we are doing the bookkeeping for an element that was
6689 directly output as a constructor, we must update
6690 constructor_unfilled_index. */
6691 constructor_unfilled_index = constructor_index;
6692 }
6693 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6694 {
6695 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6696
6697 /* Do a basic check of initializer size. Note that vectors
6698 always have a fixed size derived from their type. */
6699 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6700 {
6701 pedwarn_init ("excess elements in vector initializer");
6702 break;
6703 }
6704
6705 /* Now output the actual element. */
6706 if (value.value)
6707 output_init_element (value.value, strict_string,
6708 elttype, constructor_index, 1);
6709
6710 constructor_index
6711 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6712
6713 if (!value.value)
6714 /* If we are doing the bookkeeping for an element that was
6715 directly output as a constructor, we must update
6716 constructor_unfilled_index. */
6717 constructor_unfilled_index = constructor_index;
6718 }
6719
6720 /* Handle the sole element allowed in a braced initializer
6721 for a scalar variable. */
6722 else if (constructor_type != error_mark_node
6723 && constructor_fields == 0)
6724 {
6725 pedwarn_init ("excess elements in scalar initializer");
6726 break;
6727 }
6728 else
6729 {
6730 if (value.value)
6731 output_init_element (value.value, strict_string,
6732 constructor_type, NULL_TREE, 1);
6733 constructor_fields = 0;
6734 }
6735
6736 /* Handle range initializers either at this level or anywhere higher
6737 in the designator stack. */
6738 if (constructor_range_stack)
6739 {
6740 struct constructor_range_stack *p, *range_stack;
6741 int finish = 0;
6742
6743 range_stack = constructor_range_stack;
6744 constructor_range_stack = 0;
6745 while (constructor_stack != range_stack->stack)
6746 {
6747 gcc_assert (constructor_stack->implicit);
6748 process_init_element (pop_init_level (1));
6749 }
6750 for (p = range_stack;
6751 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6752 p = p->prev)
6753 {
6754 gcc_assert (constructor_stack->implicit);
6755 process_init_element (pop_init_level (1));
6756 }
6757
6758 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6759 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6760 finish = 1;
6761
6762 while (1)
6763 {
6764 constructor_index = p->index;
6765 constructor_fields = p->fields;
6766 if (finish && p->range_end && p->index == p->range_start)
6767 {
6768 finish = 0;
6769 p->prev = 0;
6770 }
6771 p = p->next;
6772 if (!p)
6773 break;
6774 push_init_level (2);
6775 p->stack = constructor_stack;
6776 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6777 p->index = p->range_start;
6778 }
6779
6780 if (!finish)
6781 constructor_range_stack = range_stack;
6782 continue;
6783 }
6784
6785 break;
6786 }
6787
6788 constructor_range_stack = 0;
6789 }
6790 \f
6791 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6792 (guaranteed to be 'volatile' or null) and ARGS (represented using
6793 an ASM_EXPR node). */
6794 tree
6795 build_asm_stmt (tree cv_qualifier, tree args)
6796 {
6797 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6798 ASM_VOLATILE_P (args) = 1;
6799 return add_stmt (args);
6800 }
6801
6802 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6803 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6804 SIMPLE indicates whether there was anything at all after the
6805 string in the asm expression -- asm("blah") and asm("blah" : )
6806 are subtly different. We use a ASM_EXPR node to represent this. */
6807 tree
6808 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6809 bool simple)
6810 {
6811 tree tail;
6812 tree args;
6813 int i;
6814 const char *constraint;
6815 const char **oconstraints;
6816 bool allows_mem, allows_reg, is_inout;
6817 int ninputs, noutputs;
6818
6819 ninputs = list_length (inputs);
6820 noutputs = list_length (outputs);
6821 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6822
6823 string = resolve_asm_operand_names (string, outputs, inputs);
6824
6825 /* Remove output conversions that change the type but not the mode. */
6826 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6827 {
6828 tree output = TREE_VALUE (tail);
6829
6830 /* ??? Really, this should not be here. Users should be using a
6831 proper lvalue, dammit. But there's a long history of using casts
6832 in the output operands. In cases like longlong.h, this becomes a
6833 primitive form of typechecking -- if the cast can be removed, then
6834 the output operand had a type of the proper width; otherwise we'll
6835 get an error. Gross, but ... */
6836 STRIP_NOPS (output);
6837
6838 if (!lvalue_or_else (output, lv_asm))
6839 output = error_mark_node;
6840
6841 if (output != error_mark_node
6842 && (TREE_READONLY (output)
6843 || TYPE_READONLY (TREE_TYPE (output))
6844 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6845 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6846 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6847 readonly_error (output, lv_asm);
6848
6849 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6850 oconstraints[i] = constraint;
6851
6852 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6853 &allows_mem, &allows_reg, &is_inout))
6854 {
6855 /* If the operand is going to end up in memory,
6856 mark it addressable. */
6857 if (!allows_reg && !c_mark_addressable (output))
6858 output = error_mark_node;
6859 }
6860 else
6861 output = error_mark_node;
6862
6863 TREE_VALUE (tail) = output;
6864 }
6865
6866 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
6867 {
6868 tree input;
6869
6870 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6871 input = TREE_VALUE (tail);
6872
6873 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
6874 oconstraints, &allows_mem, &allows_reg))
6875 {
6876 /* If the operand is going to end up in memory,
6877 mark it addressable. */
6878 if (!allows_reg && allows_mem)
6879 {
6880 /* Strip the nops as we allow this case. FIXME, this really
6881 should be rejected or made deprecated. */
6882 STRIP_NOPS (input);
6883 if (!c_mark_addressable (input))
6884 input = error_mark_node;
6885 }
6886 }
6887 else
6888 input = error_mark_node;
6889
6890 TREE_VALUE (tail) = input;
6891 }
6892
6893 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
6894
6895 /* asm statements without outputs, including simple ones, are treated
6896 as volatile. */
6897 ASM_INPUT_P (args) = simple;
6898 ASM_VOLATILE_P (args) = (noutputs == 0);
6899
6900 return args;
6901 }
6902 \f
6903 /* Generate a goto statement to LABEL. */
6904
6905 tree
6906 c_finish_goto_label (tree label)
6907 {
6908 tree decl = lookup_label (label);
6909 if (!decl)
6910 return NULL_TREE;
6911
6912 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
6913 {
6914 error ("jump into statement expression");
6915 return NULL_TREE;
6916 }
6917
6918 if (C_DECL_UNJUMPABLE_VM (decl))
6919 {
6920 error ("jump into scope of identifier with variably modified type");
6921 return NULL_TREE;
6922 }
6923
6924 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
6925 {
6926 /* No jump from outside this statement expression context, so
6927 record that there is a jump from within this context. */
6928 struct c_label_list *nlist;
6929 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6930 nlist->next = label_context_stack_se->labels_used;
6931 nlist->label = decl;
6932 label_context_stack_se->labels_used = nlist;
6933 }
6934
6935 if (!C_DECL_UNDEFINABLE_VM (decl))
6936 {
6937 /* No jump from outside this context context of identifiers with
6938 variably modified type, so record that there is a jump from
6939 within this context. */
6940 struct c_label_list *nlist;
6941 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6942 nlist->next = label_context_stack_vm->labels_used;
6943 nlist->label = decl;
6944 label_context_stack_vm->labels_used = nlist;
6945 }
6946
6947 TREE_USED (decl) = 1;
6948 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
6949 }
6950
6951 /* Generate a computed goto statement to EXPR. */
6952
6953 tree
6954 c_finish_goto_ptr (tree expr)
6955 {
6956 if (pedantic)
6957 pedwarn ("ISO C forbids %<goto *expr;%>");
6958 expr = convert (ptr_type_node, expr);
6959 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
6960 }
6961
6962 /* Generate a C `return' statement. RETVAL is the expression for what
6963 to return, or a null pointer for `return;' with no value. */
6964
6965 tree
6966 c_finish_return (tree retval)
6967 {
6968 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
6969 bool no_warning = false;
6970
6971 if (TREE_THIS_VOLATILE (current_function_decl))
6972 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6973
6974 if (!retval)
6975 {
6976 current_function_returns_null = 1;
6977 if ((warn_return_type || flag_isoc99)
6978 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
6979 {
6980 pedwarn_c99 ("%<return%> with no value, in "
6981 "function returning non-void");
6982 no_warning = true;
6983 }
6984 }
6985 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
6986 {
6987 current_function_returns_null = 1;
6988 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
6989 pedwarn ("%<return%> with a value, in function returning void");
6990 }
6991 else
6992 {
6993 tree t = convert_for_assignment (valtype, retval, ic_return,
6994 NULL_TREE, NULL_TREE, 0);
6995 tree res = DECL_RESULT (current_function_decl);
6996 tree inner;
6997
6998 current_function_returns_value = 1;
6999 if (t == error_mark_node)
7000 return NULL_TREE;
7001
7002 inner = t = convert (TREE_TYPE (res), t);
7003
7004 /* Strip any conversions, additions, and subtractions, and see if
7005 we are returning the address of a local variable. Warn if so. */
7006 while (1)
7007 {
7008 switch (TREE_CODE (inner))
7009 {
7010 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
7011 case PLUS_EXPR:
7012 inner = TREE_OPERAND (inner, 0);
7013 continue;
7014
7015 case MINUS_EXPR:
7016 /* If the second operand of the MINUS_EXPR has a pointer
7017 type (or is converted from it), this may be valid, so
7018 don't give a warning. */
7019 {
7020 tree op1 = TREE_OPERAND (inner, 1);
7021
7022 while (!POINTER_TYPE_P (TREE_TYPE (op1))
7023 && (TREE_CODE (op1) == NOP_EXPR
7024 || TREE_CODE (op1) == NON_LVALUE_EXPR
7025 || TREE_CODE (op1) == CONVERT_EXPR))
7026 op1 = TREE_OPERAND (op1, 0);
7027
7028 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7029 break;
7030
7031 inner = TREE_OPERAND (inner, 0);
7032 continue;
7033 }
7034
7035 case ADDR_EXPR:
7036 inner = TREE_OPERAND (inner, 0);
7037
7038 while (REFERENCE_CLASS_P (inner)
7039 && TREE_CODE (inner) != INDIRECT_REF)
7040 inner = TREE_OPERAND (inner, 0);
7041
7042 if (DECL_P (inner)
7043 && !DECL_EXTERNAL (inner)
7044 && !TREE_STATIC (inner)
7045 && DECL_CONTEXT (inner) == current_function_decl)
7046 warning (0, "function returns address of local variable");
7047 break;
7048
7049 default:
7050 break;
7051 }
7052
7053 break;
7054 }
7055
7056 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7057 }
7058
7059 ret_stmt = build_stmt (RETURN_EXPR, retval);
7060 TREE_NO_WARNING (ret_stmt) |= no_warning;
7061 return add_stmt (ret_stmt);
7062 }
7063 \f
7064 struct c_switch {
7065 /* The SWITCH_EXPR being built. */
7066 tree switch_expr;
7067
7068 /* The original type of the testing expression, i.e. before the
7069 default conversion is applied. */
7070 tree orig_type;
7071
7072 /* A splay-tree mapping the low element of a case range to the high
7073 element, or NULL_TREE if there is no high element. Used to
7074 determine whether or not a new case label duplicates an old case
7075 label. We need a tree, rather than simply a hash table, because
7076 of the GNU case range extension. */
7077 splay_tree cases;
7078
7079 /* Number of nested statement expressions within this switch
7080 statement; if nonzero, case and default labels may not
7081 appear. */
7082 unsigned int blocked_stmt_expr;
7083
7084 /* Scope of outermost declarations of identifiers with variably
7085 modified type within this switch statement; if nonzero, case and
7086 default labels may not appear. */
7087 unsigned int blocked_vm;
7088
7089 /* The next node on the stack. */
7090 struct c_switch *next;
7091 };
7092
7093 /* A stack of the currently active switch statements. The innermost
7094 switch statement is on the top of the stack. There is no need to
7095 mark the stack for garbage collection because it is only active
7096 during the processing of the body of a function, and we never
7097 collect at that point. */
7098
7099 struct c_switch *c_switch_stack;
7100
7101 /* Start a C switch statement, testing expression EXP. Return the new
7102 SWITCH_EXPR. */
7103
7104 tree
7105 c_start_case (tree exp)
7106 {
7107 tree orig_type = error_mark_node;
7108 struct c_switch *cs;
7109
7110 if (exp != error_mark_node)
7111 {
7112 orig_type = TREE_TYPE (exp);
7113
7114 if (!INTEGRAL_TYPE_P (orig_type))
7115 {
7116 if (orig_type != error_mark_node)
7117 {
7118 error ("switch quantity not an integer");
7119 orig_type = error_mark_node;
7120 }
7121 exp = integer_zero_node;
7122 }
7123 else
7124 {
7125 tree type = TYPE_MAIN_VARIANT (orig_type);
7126
7127 if (!in_system_header
7128 && (type == long_integer_type_node
7129 || type == long_unsigned_type_node))
7130 warning (OPT_Wtraditional, "%<long%> switch expression not "
7131 "converted to %<int%> in ISO C");
7132
7133 exp = default_conversion (exp);
7134 }
7135 }
7136
7137 /* Add this new SWITCH_EXPR to the stack. */
7138 cs = XNEW (struct c_switch);
7139 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7140 cs->orig_type = orig_type;
7141 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7142 cs->blocked_stmt_expr = 0;
7143 cs->blocked_vm = 0;
7144 cs->next = c_switch_stack;
7145 c_switch_stack = cs;
7146
7147 return add_stmt (cs->switch_expr);
7148 }
7149
7150 /* Process a case label. */
7151
7152 tree
7153 do_case (tree low_value, tree high_value)
7154 {
7155 tree label = NULL_TREE;
7156
7157 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7158 && !c_switch_stack->blocked_vm)
7159 {
7160 label = c_add_case_label (c_switch_stack->cases,
7161 SWITCH_COND (c_switch_stack->switch_expr),
7162 c_switch_stack->orig_type,
7163 low_value, high_value);
7164 if (label == error_mark_node)
7165 label = NULL_TREE;
7166 }
7167 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7168 {
7169 if (low_value)
7170 error ("case label in statement expression not containing "
7171 "enclosing switch statement");
7172 else
7173 error ("%<default%> label in statement expression not containing "
7174 "enclosing switch statement");
7175 }
7176 else if (c_switch_stack && c_switch_stack->blocked_vm)
7177 {
7178 if (low_value)
7179 error ("case label in scope of identifier with variably modified "
7180 "type not containing enclosing switch statement");
7181 else
7182 error ("%<default%> label in scope of identifier with variably "
7183 "modified type not containing enclosing switch statement");
7184 }
7185 else if (low_value)
7186 error ("case label not within a switch statement");
7187 else
7188 error ("%<default%> label not within a switch statement");
7189
7190 return label;
7191 }
7192
7193 /* Finish the switch statement. */
7194
7195 void
7196 c_finish_case (tree body)
7197 {
7198 struct c_switch *cs = c_switch_stack;
7199 location_t switch_location;
7200
7201 SWITCH_BODY (cs->switch_expr) = body;
7202
7203 /* We must not be within a statement expression nested in the switch
7204 at this point; we might, however, be within the scope of an
7205 identifier with variably modified type nested in the switch. */
7206 gcc_assert (!cs->blocked_stmt_expr);
7207
7208 /* Emit warnings as needed. */
7209 if (EXPR_HAS_LOCATION (cs->switch_expr))
7210 switch_location = EXPR_LOCATION (cs->switch_expr);
7211 else
7212 switch_location = input_location;
7213 c_do_switch_warnings (cs->cases, switch_location,
7214 TREE_TYPE (cs->switch_expr),
7215 SWITCH_COND (cs->switch_expr));
7216
7217 /* Pop the stack. */
7218 c_switch_stack = cs->next;
7219 splay_tree_delete (cs->cases);
7220 XDELETE (cs);
7221 }
7222 \f
7223 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7224 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7225 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7226 statement, and was not surrounded with parenthesis. */
7227
7228 void
7229 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7230 tree else_block, bool nested_if)
7231 {
7232 tree stmt;
7233
7234 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7235 if (warn_parentheses && nested_if && else_block == NULL)
7236 {
7237 tree inner_if = then_block;
7238
7239 /* We know from the grammar productions that there is an IF nested
7240 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7241 it might not be exactly THEN_BLOCK, but should be the last
7242 non-container statement within. */
7243 while (1)
7244 switch (TREE_CODE (inner_if))
7245 {
7246 case COND_EXPR:
7247 goto found;
7248 case BIND_EXPR:
7249 inner_if = BIND_EXPR_BODY (inner_if);
7250 break;
7251 case STATEMENT_LIST:
7252 inner_if = expr_last (then_block);
7253 break;
7254 case TRY_FINALLY_EXPR:
7255 case TRY_CATCH_EXPR:
7256 inner_if = TREE_OPERAND (inner_if, 0);
7257 break;
7258 default:
7259 gcc_unreachable ();
7260 }
7261 found:
7262
7263 if (COND_EXPR_ELSE (inner_if))
7264 warning (OPT_Wparentheses,
7265 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7266 &if_locus);
7267 }
7268
7269 empty_body_warning (then_block, else_block);
7270
7271 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7272 SET_EXPR_LOCATION (stmt, if_locus);
7273 add_stmt (stmt);
7274 }
7275
7276 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7277 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7278 is false for DO loops. INCR is the FOR increment expression. BODY is
7279 the statement controlled by the loop. BLAB is the break label. CLAB is
7280 the continue label. Everything is allowed to be NULL. */
7281
7282 void
7283 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7284 tree blab, tree clab, bool cond_is_first)
7285 {
7286 tree entry = NULL, exit = NULL, t;
7287
7288 /* If the condition is zero don't generate a loop construct. */
7289 if (cond && integer_zerop (cond))
7290 {
7291 if (cond_is_first)
7292 {
7293 t = build_and_jump (&blab);
7294 SET_EXPR_LOCATION (t, start_locus);
7295 add_stmt (t);
7296 }
7297 }
7298 else
7299 {
7300 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7301
7302 /* If we have an exit condition, then we build an IF with gotos either
7303 out of the loop, or to the top of it. If there's no exit condition,
7304 then we just build a jump back to the top. */
7305 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7306
7307 if (cond && !integer_nonzerop (cond))
7308 {
7309 /* Canonicalize the loop condition to the end. This means
7310 generating a branch to the loop condition. Reuse the
7311 continue label, if possible. */
7312 if (cond_is_first)
7313 {
7314 if (incr || !clab)
7315 {
7316 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7317 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7318 }
7319 else
7320 t = build1 (GOTO_EXPR, void_type_node, clab);
7321 SET_EXPR_LOCATION (t, start_locus);
7322 add_stmt (t);
7323 }
7324
7325 t = build_and_jump (&blab);
7326 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7327 if (cond_is_first)
7328 SET_EXPR_LOCATION (exit, start_locus);
7329 else
7330 SET_EXPR_LOCATION (exit, input_location);
7331 }
7332
7333 add_stmt (top);
7334 }
7335
7336 if (body)
7337 add_stmt (body);
7338 if (clab)
7339 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7340 if (incr)
7341 add_stmt (incr);
7342 if (entry)
7343 add_stmt (entry);
7344 if (exit)
7345 add_stmt (exit);
7346 if (blab)
7347 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7348 }
7349
7350 tree
7351 c_finish_bc_stmt (tree *label_p, bool is_break)
7352 {
7353 bool skip;
7354 tree label = *label_p;
7355
7356 /* In switch statements break is sometimes stylistically used after
7357 a return statement. This can lead to spurious warnings about
7358 control reaching the end of a non-void function when it is
7359 inlined. Note that we are calling block_may_fallthru with
7360 language specific tree nodes; this works because
7361 block_may_fallthru returns true when given something it does not
7362 understand. */
7363 skip = !block_may_fallthru (cur_stmt_list);
7364
7365 if (!label)
7366 {
7367 if (!skip)
7368 *label_p = label = create_artificial_label ();
7369 }
7370 else if (TREE_CODE (label) == LABEL_DECL)
7371 ;
7372 else switch (TREE_INT_CST_LOW (label))
7373 {
7374 case 0:
7375 if (is_break)
7376 error ("break statement not within loop or switch");
7377 else
7378 error ("continue statement not within a loop");
7379 return NULL_TREE;
7380
7381 case 1:
7382 gcc_assert (is_break);
7383 error ("break statement used with OpenMP for loop");
7384 return NULL_TREE;
7385
7386 default:
7387 gcc_unreachable ();
7388 }
7389
7390 if (skip)
7391 return NULL_TREE;
7392
7393 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7394 }
7395
7396 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7397
7398 static void
7399 emit_side_effect_warnings (tree expr)
7400 {
7401 if (expr == error_mark_node)
7402 ;
7403 else if (!TREE_SIDE_EFFECTS (expr))
7404 {
7405 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7406 warning (0, "%Hstatement with no effect",
7407 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7408 }
7409 else if (warn_unused_value)
7410 warn_if_unused_value (expr, input_location);
7411 }
7412
7413 /* Process an expression as if it were a complete statement. Emit
7414 diagnostics, but do not call ADD_STMT. */
7415
7416 tree
7417 c_process_expr_stmt (tree expr)
7418 {
7419 if (!expr)
7420 return NULL_TREE;
7421
7422 if (warn_sequence_point)
7423 verify_sequence_points (expr);
7424
7425 if (TREE_TYPE (expr) != error_mark_node
7426 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7427 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7428 error ("expression statement has incomplete type");
7429
7430 /* If we're not processing a statement expression, warn about unused values.
7431 Warnings for statement expressions will be emitted later, once we figure
7432 out which is the result. */
7433 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7434 && (extra_warnings || warn_unused_value))
7435 emit_side_effect_warnings (expr);
7436
7437 /* If the expression is not of a type to which we cannot assign a line
7438 number, wrap the thing in a no-op NOP_EXPR. */
7439 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7440 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7441
7442 if (EXPR_P (expr))
7443 SET_EXPR_LOCATION (expr, input_location);
7444
7445 return expr;
7446 }
7447
7448 /* Emit an expression as a statement. */
7449
7450 tree
7451 c_finish_expr_stmt (tree expr)
7452 {
7453 if (expr)
7454 return add_stmt (c_process_expr_stmt (expr));
7455 else
7456 return NULL;
7457 }
7458
7459 /* Do the opposite and emit a statement as an expression. To begin,
7460 create a new binding level and return it. */
7461
7462 tree
7463 c_begin_stmt_expr (void)
7464 {
7465 tree ret;
7466 struct c_label_context_se *nstack;
7467 struct c_label_list *glist;
7468
7469 /* We must force a BLOCK for this level so that, if it is not expanded
7470 later, there is a way to turn off the entire subtree of blocks that
7471 are contained in it. */
7472 keep_next_level ();
7473 ret = c_begin_compound_stmt (true);
7474 if (c_switch_stack)
7475 {
7476 c_switch_stack->blocked_stmt_expr++;
7477 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7478 }
7479 for (glist = label_context_stack_se->labels_used;
7480 glist != NULL;
7481 glist = glist->next)
7482 {
7483 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7484 }
7485 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7486 nstack->labels_def = NULL;
7487 nstack->labels_used = NULL;
7488 nstack->next = label_context_stack_se;
7489 label_context_stack_se = nstack;
7490
7491 /* Mark the current statement list as belonging to a statement list. */
7492 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7493
7494 return ret;
7495 }
7496
7497 tree
7498 c_finish_stmt_expr (tree body)
7499 {
7500 tree last, type, tmp, val;
7501 tree *last_p;
7502 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7503
7504 body = c_end_compound_stmt (body, true);
7505 if (c_switch_stack)
7506 {
7507 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7508 c_switch_stack->blocked_stmt_expr--;
7509 }
7510 /* It is no longer possible to jump to labels defined within this
7511 statement expression. */
7512 for (dlist = label_context_stack_se->labels_def;
7513 dlist != NULL;
7514 dlist = dlist->next)
7515 {
7516 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7517 }
7518 /* It is again possible to define labels with a goto just outside
7519 this statement expression. */
7520 for (glist = label_context_stack_se->next->labels_used;
7521 glist != NULL;
7522 glist = glist->next)
7523 {
7524 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7525 glist_prev = glist;
7526 }
7527 if (glist_prev != NULL)
7528 glist_prev->next = label_context_stack_se->labels_used;
7529 else
7530 label_context_stack_se->next->labels_used
7531 = label_context_stack_se->labels_used;
7532 label_context_stack_se = label_context_stack_se->next;
7533
7534 /* Locate the last statement in BODY. See c_end_compound_stmt
7535 about always returning a BIND_EXPR. */
7536 last_p = &BIND_EXPR_BODY (body);
7537 last = BIND_EXPR_BODY (body);
7538
7539 continue_searching:
7540 if (TREE_CODE (last) == STATEMENT_LIST)
7541 {
7542 tree_stmt_iterator i;
7543
7544 /* This can happen with degenerate cases like ({ }). No value. */
7545 if (!TREE_SIDE_EFFECTS (last))
7546 return body;
7547
7548 /* If we're supposed to generate side effects warnings, process
7549 all of the statements except the last. */
7550 if (extra_warnings || warn_unused_value)
7551 {
7552 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7553 emit_side_effect_warnings (tsi_stmt (i));
7554 }
7555 else
7556 i = tsi_last (last);
7557 last_p = tsi_stmt_ptr (i);
7558 last = *last_p;
7559 }
7560
7561 /* If the end of the list is exception related, then the list was split
7562 by a call to push_cleanup. Continue searching. */
7563 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7564 || TREE_CODE (last) == TRY_CATCH_EXPR)
7565 {
7566 last_p = &TREE_OPERAND (last, 0);
7567 last = *last_p;
7568 goto continue_searching;
7569 }
7570
7571 /* In the case that the BIND_EXPR is not necessary, return the
7572 expression out from inside it. */
7573 if (last == error_mark_node
7574 || (last == BIND_EXPR_BODY (body)
7575 && BIND_EXPR_VARS (body) == NULL))
7576 {
7577 /* Do not warn if the return value of a statement expression is
7578 unused. */
7579 if (EXPR_P (last))
7580 TREE_NO_WARNING (last) = 1;
7581 return last;
7582 }
7583
7584 /* Extract the type of said expression. */
7585 type = TREE_TYPE (last);
7586
7587 /* If we're not returning a value at all, then the BIND_EXPR that
7588 we already have is a fine expression to return. */
7589 if (!type || VOID_TYPE_P (type))
7590 return body;
7591
7592 /* Now that we've located the expression containing the value, it seems
7593 silly to make voidify_wrapper_expr repeat the process. Create a
7594 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7595 tmp = create_tmp_var_raw (type, NULL);
7596
7597 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7598 tree_expr_nonnegative_p giving up immediately. */
7599 val = last;
7600 if (TREE_CODE (val) == NOP_EXPR
7601 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7602 val = TREE_OPERAND (val, 0);
7603
7604 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7605 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7606
7607 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7608 }
7609
7610 /* Begin the scope of an identifier of variably modified type, scope
7611 number SCOPE. Jumping from outside this scope to inside it is not
7612 permitted. */
7613
7614 void
7615 c_begin_vm_scope (unsigned int scope)
7616 {
7617 struct c_label_context_vm *nstack;
7618 struct c_label_list *glist;
7619
7620 gcc_assert (scope > 0);
7621
7622 /* At file_scope, we don't have to do any processing. */
7623 if (label_context_stack_vm == NULL)
7624 return;
7625
7626 if (c_switch_stack && !c_switch_stack->blocked_vm)
7627 c_switch_stack->blocked_vm = scope;
7628 for (glist = label_context_stack_vm->labels_used;
7629 glist != NULL;
7630 glist = glist->next)
7631 {
7632 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7633 }
7634 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7635 nstack->labels_def = NULL;
7636 nstack->labels_used = NULL;
7637 nstack->scope = scope;
7638 nstack->next = label_context_stack_vm;
7639 label_context_stack_vm = nstack;
7640 }
7641
7642 /* End a scope which may contain identifiers of variably modified
7643 type, scope number SCOPE. */
7644
7645 void
7646 c_end_vm_scope (unsigned int scope)
7647 {
7648 if (label_context_stack_vm == NULL)
7649 return;
7650 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7651 c_switch_stack->blocked_vm = 0;
7652 /* We may have a number of nested scopes of identifiers with
7653 variably modified type, all at this depth. Pop each in turn. */
7654 while (label_context_stack_vm->scope == scope)
7655 {
7656 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7657
7658 /* It is no longer possible to jump to labels defined within this
7659 scope. */
7660 for (dlist = label_context_stack_vm->labels_def;
7661 dlist != NULL;
7662 dlist = dlist->next)
7663 {
7664 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7665 }
7666 /* It is again possible to define labels with a goto just outside
7667 this scope. */
7668 for (glist = label_context_stack_vm->next->labels_used;
7669 glist != NULL;
7670 glist = glist->next)
7671 {
7672 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7673 glist_prev = glist;
7674 }
7675 if (glist_prev != NULL)
7676 glist_prev->next = label_context_stack_vm->labels_used;
7677 else
7678 label_context_stack_vm->next->labels_used
7679 = label_context_stack_vm->labels_used;
7680 label_context_stack_vm = label_context_stack_vm->next;
7681 }
7682 }
7683 \f
7684 /* Begin and end compound statements. This is as simple as pushing
7685 and popping new statement lists from the tree. */
7686
7687 tree
7688 c_begin_compound_stmt (bool do_scope)
7689 {
7690 tree stmt = push_stmt_list ();
7691 if (do_scope)
7692 push_scope ();
7693 return stmt;
7694 }
7695
7696 tree
7697 c_end_compound_stmt (tree stmt, bool do_scope)
7698 {
7699 tree block = NULL;
7700
7701 if (do_scope)
7702 {
7703 if (c_dialect_objc ())
7704 objc_clear_super_receiver ();
7705 block = pop_scope ();
7706 }
7707
7708 stmt = pop_stmt_list (stmt);
7709 stmt = c_build_bind_expr (block, stmt);
7710
7711 /* If this compound statement is nested immediately inside a statement
7712 expression, then force a BIND_EXPR to be created. Otherwise we'll
7713 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7714 STATEMENT_LISTs merge, and thus we can lose track of what statement
7715 was really last. */
7716 if (cur_stmt_list
7717 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7718 && TREE_CODE (stmt) != BIND_EXPR)
7719 {
7720 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7721 TREE_SIDE_EFFECTS (stmt) = 1;
7722 }
7723
7724 return stmt;
7725 }
7726
7727 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7728 when the current scope is exited. EH_ONLY is true when this is not
7729 meant to apply to normal control flow transfer. */
7730
7731 void
7732 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7733 {
7734 enum tree_code code;
7735 tree stmt, list;
7736 bool stmt_expr;
7737
7738 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7739 stmt = build_stmt (code, NULL, cleanup);
7740 add_stmt (stmt);
7741 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7742 list = push_stmt_list ();
7743 TREE_OPERAND (stmt, 0) = list;
7744 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7745 }
7746 \f
7747 /* Build a binary-operation expression without default conversions.
7748 CODE is the kind of expression to build.
7749 This function differs from `build' in several ways:
7750 the data type of the result is computed and recorded in it,
7751 warnings are generated if arg data types are invalid,
7752 special handling for addition and subtraction of pointers is known,
7753 and some optimization is done (operations on narrow ints
7754 are done in the narrower type when that gives the same result).
7755 Constant folding is also done before the result is returned.
7756
7757 Note that the operands will never have enumeral types, or function
7758 or array types, because either they will have the default conversions
7759 performed or they have both just been converted to some other type in which
7760 the arithmetic is to be done. */
7761
7762 tree
7763 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7764 int convert_p)
7765 {
7766 tree type0, type1;
7767 enum tree_code code0, code1;
7768 tree op0, op1;
7769 const char *invalid_op_diag;
7770
7771 /* Expression code to give to the expression when it is built.
7772 Normally this is CODE, which is what the caller asked for,
7773 but in some special cases we change it. */
7774 enum tree_code resultcode = code;
7775
7776 /* Data type in which the computation is to be performed.
7777 In the simplest cases this is the common type of the arguments. */
7778 tree result_type = NULL;
7779
7780 /* Nonzero means operands have already been type-converted
7781 in whatever way is necessary.
7782 Zero means they need to be converted to RESULT_TYPE. */
7783 int converted = 0;
7784
7785 /* Nonzero means create the expression with this type, rather than
7786 RESULT_TYPE. */
7787 tree build_type = 0;
7788
7789 /* Nonzero means after finally constructing the expression
7790 convert it to this type. */
7791 tree final_type = 0;
7792
7793 /* Nonzero if this is an operation like MIN or MAX which can
7794 safely be computed in short if both args are promoted shorts.
7795 Also implies COMMON.
7796 -1 indicates a bitwise operation; this makes a difference
7797 in the exact conditions for when it is safe to do the operation
7798 in a narrower mode. */
7799 int shorten = 0;
7800
7801 /* Nonzero if this is a comparison operation;
7802 if both args are promoted shorts, compare the original shorts.
7803 Also implies COMMON. */
7804 int short_compare = 0;
7805
7806 /* Nonzero if this is a right-shift operation, which can be computed on the
7807 original short and then promoted if the operand is a promoted short. */
7808 int short_shift = 0;
7809
7810 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7811 int common = 0;
7812
7813 /* True means types are compatible as far as ObjC is concerned. */
7814 bool objc_ok;
7815
7816 if (convert_p)
7817 {
7818 op0 = default_conversion (orig_op0);
7819 op1 = default_conversion (orig_op1);
7820 }
7821 else
7822 {
7823 op0 = orig_op0;
7824 op1 = orig_op1;
7825 }
7826
7827 type0 = TREE_TYPE (op0);
7828 type1 = TREE_TYPE (op1);
7829
7830 /* The expression codes of the data types of the arguments tell us
7831 whether the arguments are integers, floating, pointers, etc. */
7832 code0 = TREE_CODE (type0);
7833 code1 = TREE_CODE (type1);
7834
7835 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7836 STRIP_TYPE_NOPS (op0);
7837 STRIP_TYPE_NOPS (op1);
7838
7839 /* If an error was already reported for one of the arguments,
7840 avoid reporting another error. */
7841
7842 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7843 return error_mark_node;
7844
7845 if ((invalid_op_diag
7846 = targetm.invalid_binary_op (code, type0, type1)))
7847 {
7848 error (invalid_op_diag);
7849 return error_mark_node;
7850 }
7851
7852 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
7853
7854 switch (code)
7855 {
7856 case PLUS_EXPR:
7857 /* Handle the pointer + int case. */
7858 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7859 return pointer_int_sum (PLUS_EXPR, op0, op1);
7860 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
7861 return pointer_int_sum (PLUS_EXPR, op1, op0);
7862 else
7863 common = 1;
7864 break;
7865
7866 case MINUS_EXPR:
7867 /* Subtraction of two similar pointers.
7868 We must subtract them as integers, then divide by object size. */
7869 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
7870 && comp_target_types (type0, type1))
7871 return pointer_diff (op0, op1);
7872 /* Handle pointer minus int. Just like pointer plus int. */
7873 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7874 return pointer_int_sum (MINUS_EXPR, op0, op1);
7875 else
7876 common = 1;
7877 break;
7878
7879 case MULT_EXPR:
7880 common = 1;
7881 break;
7882
7883 case TRUNC_DIV_EXPR:
7884 case CEIL_DIV_EXPR:
7885 case FLOOR_DIV_EXPR:
7886 case ROUND_DIV_EXPR:
7887 case EXACT_DIV_EXPR:
7888 /* Floating point division by zero is a legitimate way to obtain
7889 infinities and NaNs. */
7890 if (skip_evaluation == 0 && integer_zerop (op1))
7891 warning (OPT_Wdiv_by_zero, "division by zero");
7892
7893 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7894 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7895 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7896 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
7897 {
7898 enum tree_code tcode0 = code0, tcode1 = code1;
7899
7900 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7901 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
7902 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
7903 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
7904
7905 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
7906 resultcode = RDIV_EXPR;
7907 else
7908 /* Although it would be tempting to shorten always here, that
7909 loses on some targets, since the modulo instruction is
7910 undefined if the quotient can't be represented in the
7911 computation mode. We shorten only if unsigned or if
7912 dividing by something we know != -1. */
7913 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7914 || (TREE_CODE (op1) == INTEGER_CST
7915 && !integer_all_onesp (op1)));
7916 common = 1;
7917 }
7918 break;
7919
7920 case BIT_AND_EXPR:
7921 case BIT_IOR_EXPR:
7922 case BIT_XOR_EXPR:
7923 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7924 shorten = -1;
7925 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
7926 common = 1;
7927 break;
7928
7929 case TRUNC_MOD_EXPR:
7930 case FLOOR_MOD_EXPR:
7931 if (skip_evaluation == 0 && integer_zerop (op1))
7932 warning (OPT_Wdiv_by_zero, "division by zero");
7933
7934 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7935 {
7936 /* Although it would be tempting to shorten always here, that loses
7937 on some targets, since the modulo instruction is undefined if the
7938 quotient can't be represented in the computation mode. We shorten
7939 only if unsigned or if dividing by something we know != -1. */
7940 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7941 || (TREE_CODE (op1) == INTEGER_CST
7942 && !integer_all_onesp (op1)));
7943 common = 1;
7944 }
7945 break;
7946
7947 case TRUTH_ANDIF_EXPR:
7948 case TRUTH_ORIF_EXPR:
7949 case TRUTH_AND_EXPR:
7950 case TRUTH_OR_EXPR:
7951 case TRUTH_XOR_EXPR:
7952 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
7953 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
7954 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
7955 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
7956 {
7957 /* Result of these operations is always an int,
7958 but that does not mean the operands should be
7959 converted to ints! */
7960 result_type = integer_type_node;
7961 op0 = c_common_truthvalue_conversion (op0);
7962 op1 = c_common_truthvalue_conversion (op1);
7963 converted = 1;
7964 }
7965 break;
7966
7967 /* Shift operations: result has same type as first operand;
7968 always convert second operand to int.
7969 Also set SHORT_SHIFT if shifting rightward. */
7970
7971 case RSHIFT_EXPR:
7972 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7973 {
7974 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7975 {
7976 if (tree_int_cst_sgn (op1) < 0)
7977 warning (0, "right shift count is negative");
7978 else
7979 {
7980 if (!integer_zerop (op1))
7981 short_shift = 1;
7982
7983 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7984 warning (0, "right shift count >= width of type");
7985 }
7986 }
7987
7988 /* Use the type of the value to be shifted. */
7989 result_type = type0;
7990 /* Convert the shift-count to an integer, regardless of size
7991 of value being shifted. */
7992 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7993 op1 = convert (integer_type_node, op1);
7994 /* Avoid converting op1 to result_type later. */
7995 converted = 1;
7996 }
7997 break;
7998
7999 case LSHIFT_EXPR:
8000 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8001 {
8002 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8003 {
8004 if (tree_int_cst_sgn (op1) < 0)
8005 warning (0, "left shift count is negative");
8006
8007 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8008 warning (0, "left shift count >= width of type");
8009 }
8010
8011 /* Use the type of the value to be shifted. */
8012 result_type = type0;
8013 /* Convert the shift-count to an integer, regardless of size
8014 of value being shifted. */
8015 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8016 op1 = convert (integer_type_node, op1);
8017 /* Avoid converting op1 to result_type later. */
8018 converted = 1;
8019 }
8020 break;
8021
8022 case EQ_EXPR:
8023 case NE_EXPR:
8024 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
8025 warning (OPT_Wfloat_equal,
8026 "comparing floating point with == or != is unsafe");
8027 /* Result of comparison is always int,
8028 but don't convert the args to int! */
8029 build_type = integer_type_node;
8030 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8031 || code0 == COMPLEX_TYPE)
8032 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8033 || code1 == COMPLEX_TYPE))
8034 short_compare = 1;
8035 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8036 {
8037 tree tt0 = TREE_TYPE (type0);
8038 tree tt1 = TREE_TYPE (type1);
8039 /* Anything compares with void *. void * compares with anything.
8040 Otherwise, the targets must be compatible
8041 and both must be object or both incomplete. */
8042 if (comp_target_types (type0, type1))
8043 result_type = common_pointer_type (type0, type1);
8044 else if (VOID_TYPE_P (tt0))
8045 {
8046 /* op0 != orig_op0 detects the case of something
8047 whose value is 0 but which isn't a valid null ptr const. */
8048 if (pedantic && !null_pointer_constant_p (orig_op0)
8049 && TREE_CODE (tt1) == FUNCTION_TYPE)
8050 pedwarn ("ISO C forbids comparison of %<void *%>"
8051 " with function pointer");
8052 }
8053 else if (VOID_TYPE_P (tt1))
8054 {
8055 if (pedantic && !null_pointer_constant_p (orig_op1)
8056 && TREE_CODE (tt0) == FUNCTION_TYPE)
8057 pedwarn ("ISO C forbids comparison of %<void *%>"
8058 " with function pointer");
8059 }
8060 else
8061 /* Avoid warning about the volatile ObjC EH puts on decls. */
8062 if (!objc_ok)
8063 pedwarn ("comparison of distinct pointer types lacks a cast");
8064
8065 if (result_type == NULL_TREE)
8066 result_type = ptr_type_node;
8067 }
8068 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8069 {
8070 if (TREE_CODE (op0) == ADDR_EXPR
8071 && DECL_P (TREE_OPERAND (op0, 0))
8072 && (TREE_CODE (TREE_OPERAND (op0, 0)) == PARM_DECL
8073 || TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL
8074 || !DECL_WEAK (TREE_OPERAND (op0, 0))))
8075 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8076 TREE_OPERAND (op0, 0));
8077 result_type = type0;
8078 }
8079 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8080 {
8081 if (TREE_CODE (op1) == ADDR_EXPR
8082 && DECL_P (TREE_OPERAND (op1, 0))
8083 && (TREE_CODE (TREE_OPERAND (op1, 0)) == PARM_DECL
8084 || TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL
8085 || !DECL_WEAK (TREE_OPERAND (op1, 0))))
8086 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8087 TREE_OPERAND (op1, 0));
8088 result_type = type1;
8089 }
8090 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8091 {
8092 result_type = type0;
8093 pedwarn ("comparison between pointer and integer");
8094 }
8095 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8096 {
8097 result_type = type1;
8098 pedwarn ("comparison between pointer and integer");
8099 }
8100 break;
8101
8102 case LE_EXPR:
8103 case GE_EXPR:
8104 case LT_EXPR:
8105 case GT_EXPR:
8106 build_type = integer_type_node;
8107 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
8108 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
8109 short_compare = 1;
8110 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8111 {
8112 if (comp_target_types (type0, type1))
8113 {
8114 result_type = common_pointer_type (type0, type1);
8115 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8116 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8117 pedwarn ("comparison of complete and incomplete pointers");
8118 else if (pedantic
8119 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8120 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
8121 }
8122 else
8123 {
8124 result_type = ptr_type_node;
8125 pedwarn ("comparison of distinct pointer types lacks a cast");
8126 }
8127 }
8128 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8129 {
8130 result_type = type0;
8131 if (pedantic || extra_warnings)
8132 pedwarn ("ordered comparison of pointer with integer zero");
8133 }
8134 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8135 {
8136 result_type = type1;
8137 if (pedantic)
8138 pedwarn ("ordered comparison of pointer with integer zero");
8139 }
8140 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8141 {
8142 result_type = type0;
8143 pedwarn ("comparison between pointer and integer");
8144 }
8145 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8146 {
8147 result_type = type1;
8148 pedwarn ("comparison between pointer and integer");
8149 }
8150 break;
8151
8152 default:
8153 gcc_unreachable ();
8154 }
8155
8156 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8157 return error_mark_node;
8158
8159 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8160 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8161 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8162 TREE_TYPE (type1))))
8163 {
8164 binary_op_error (code);
8165 return error_mark_node;
8166 }
8167
8168 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8169 || code0 == VECTOR_TYPE)
8170 &&
8171 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8172 || code1 == VECTOR_TYPE))
8173 {
8174 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8175
8176 if (shorten || common || short_compare)
8177 result_type = c_common_type (type0, type1);
8178
8179 /* For certain operations (which identify themselves by shorten != 0)
8180 if both args were extended from the same smaller type,
8181 do the arithmetic in that type and then extend.
8182
8183 shorten !=0 and !=1 indicates a bitwise operation.
8184 For them, this optimization is safe only if
8185 both args are zero-extended or both are sign-extended.
8186 Otherwise, we might change the result.
8187 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8188 but calculated in (unsigned short) it would be (unsigned short)-1. */
8189
8190 if (shorten && none_complex)
8191 {
8192 int unsigned0, unsigned1;
8193 tree arg0, arg1;
8194 int uns;
8195 tree type;
8196
8197 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8198 excessive narrowing when we call get_narrower below. For
8199 example, suppose that OP0 is of unsigned int extended
8200 from signed char and that RESULT_TYPE is long long int.
8201 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8202 like
8203
8204 (long long int) (unsigned int) signed_char
8205
8206 which get_narrower would narrow down to
8207
8208 (unsigned int) signed char
8209
8210 If we do not cast OP0 first, get_narrower would return
8211 signed_char, which is inconsistent with the case of the
8212 explicit cast. */
8213 op0 = convert (result_type, op0);
8214 op1 = convert (result_type, op1);
8215
8216 arg0 = get_narrower (op0, &unsigned0);
8217 arg1 = get_narrower (op1, &unsigned1);
8218
8219 /* UNS is 1 if the operation to be done is an unsigned one. */
8220 uns = TYPE_UNSIGNED (result_type);
8221
8222 final_type = result_type;
8223
8224 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8225 but it *requires* conversion to FINAL_TYPE. */
8226
8227 if ((TYPE_PRECISION (TREE_TYPE (op0))
8228 == TYPE_PRECISION (TREE_TYPE (arg0)))
8229 && TREE_TYPE (op0) != final_type)
8230 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
8231 if ((TYPE_PRECISION (TREE_TYPE (op1))
8232 == TYPE_PRECISION (TREE_TYPE (arg1)))
8233 && TREE_TYPE (op1) != final_type)
8234 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
8235
8236 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8237
8238 /* For bitwise operations, signedness of nominal type
8239 does not matter. Consider only how operands were extended. */
8240 if (shorten == -1)
8241 uns = unsigned0;
8242
8243 /* Note that in all three cases below we refrain from optimizing
8244 an unsigned operation on sign-extended args.
8245 That would not be valid. */
8246
8247 /* Both args variable: if both extended in same way
8248 from same width, do it in that width.
8249 Do it unsigned if args were zero-extended. */
8250 if ((TYPE_PRECISION (TREE_TYPE (arg0))
8251 < TYPE_PRECISION (result_type))
8252 && (TYPE_PRECISION (TREE_TYPE (arg1))
8253 == TYPE_PRECISION (TREE_TYPE (arg0)))
8254 && unsigned0 == unsigned1
8255 && (unsigned0 || !uns))
8256 result_type
8257 = c_common_signed_or_unsigned_type
8258 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
8259 else if (TREE_CODE (arg0) == INTEGER_CST
8260 && (unsigned1 || !uns)
8261 && (TYPE_PRECISION (TREE_TYPE (arg1))
8262 < TYPE_PRECISION (result_type))
8263 && (type
8264 = c_common_signed_or_unsigned_type (unsigned1,
8265 TREE_TYPE (arg1)),
8266 int_fits_type_p (arg0, type)))
8267 result_type = type;
8268 else if (TREE_CODE (arg1) == INTEGER_CST
8269 && (unsigned0 || !uns)
8270 && (TYPE_PRECISION (TREE_TYPE (arg0))
8271 < TYPE_PRECISION (result_type))
8272 && (type
8273 = c_common_signed_or_unsigned_type (unsigned0,
8274 TREE_TYPE (arg0)),
8275 int_fits_type_p (arg1, type)))
8276 result_type = type;
8277 }
8278
8279 /* Shifts can be shortened if shifting right. */
8280
8281 if (short_shift)
8282 {
8283 int unsigned_arg;
8284 tree arg0 = get_narrower (op0, &unsigned_arg);
8285
8286 final_type = result_type;
8287
8288 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8289 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8290
8291 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8292 /* We can shorten only if the shift count is less than the
8293 number of bits in the smaller type size. */
8294 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8295 /* We cannot drop an unsigned shift after sign-extension. */
8296 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8297 {
8298 /* Do an unsigned shift if the operand was zero-extended. */
8299 result_type
8300 = c_common_signed_or_unsigned_type (unsigned_arg,
8301 TREE_TYPE (arg0));
8302 /* Convert value-to-be-shifted to that type. */
8303 if (TREE_TYPE (op0) != result_type)
8304 op0 = convert (result_type, op0);
8305 converted = 1;
8306 }
8307 }
8308
8309 /* Comparison operations are shortened too but differently.
8310 They identify themselves by setting short_compare = 1. */
8311
8312 if (short_compare)
8313 {
8314 /* Don't write &op0, etc., because that would prevent op0
8315 from being kept in a register.
8316 Instead, make copies of the our local variables and
8317 pass the copies by reference, then copy them back afterward. */
8318 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8319 enum tree_code xresultcode = resultcode;
8320 tree val
8321 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8322
8323 if (val != 0)
8324 return val;
8325
8326 op0 = xop0, op1 = xop1;
8327 converted = 1;
8328 resultcode = xresultcode;
8329
8330 if (warn_sign_compare && skip_evaluation == 0)
8331 {
8332 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8333 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8334 int unsignedp0, unsignedp1;
8335 tree primop0 = get_narrower (op0, &unsignedp0);
8336 tree primop1 = get_narrower (op1, &unsignedp1);
8337
8338 xop0 = orig_op0;
8339 xop1 = orig_op1;
8340 STRIP_TYPE_NOPS (xop0);
8341 STRIP_TYPE_NOPS (xop1);
8342
8343 /* Give warnings for comparisons between signed and unsigned
8344 quantities that may fail.
8345
8346 Do the checking based on the original operand trees, so that
8347 casts will be considered, but default promotions won't be.
8348
8349 Do not warn if the comparison is being done in a signed type,
8350 since the signed type will only be chosen if it can represent
8351 all the values of the unsigned type. */
8352 if (!TYPE_UNSIGNED (result_type))
8353 /* OK */;
8354 /* Do not warn if both operands are the same signedness. */
8355 else if (op0_signed == op1_signed)
8356 /* OK */;
8357 else
8358 {
8359 tree sop, uop;
8360
8361 if (op0_signed)
8362 sop = xop0, uop = xop1;
8363 else
8364 sop = xop1, uop = xop0;
8365
8366 /* Do not warn if the signed quantity is an
8367 unsuffixed integer literal (or some static
8368 constant expression involving such literals or a
8369 conditional expression involving such literals)
8370 and it is non-negative. */
8371 if (tree_expr_nonnegative_p (sop))
8372 /* OK */;
8373 /* Do not warn if the comparison is an equality operation,
8374 the unsigned quantity is an integral constant, and it
8375 would fit in the result if the result were signed. */
8376 else if (TREE_CODE (uop) == INTEGER_CST
8377 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8378 && int_fits_type_p
8379 (uop, c_common_signed_type (result_type)))
8380 /* OK */;
8381 /* Do not warn if the unsigned quantity is an enumeration
8382 constant and its maximum value would fit in the result
8383 if the result were signed. */
8384 else if (TREE_CODE (uop) == INTEGER_CST
8385 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8386 && int_fits_type_p
8387 (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8388 c_common_signed_type (result_type)))
8389 /* OK */;
8390 else
8391 warning (0, "comparison between signed and unsigned");
8392 }
8393
8394 /* Warn if two unsigned values are being compared in a size
8395 larger than their original size, and one (and only one) is the
8396 result of a `~' operator. This comparison will always fail.
8397
8398 Also warn if one operand is a constant, and the constant
8399 does not have all bits set that are set in the ~ operand
8400 when it is extended. */
8401
8402 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
8403 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
8404 {
8405 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
8406 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
8407 &unsignedp0);
8408 else
8409 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
8410 &unsignedp1);
8411
8412 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
8413 {
8414 tree primop;
8415 HOST_WIDE_INT constant, mask;
8416 int unsignedp, bits;
8417
8418 if (host_integerp (primop0, 0))
8419 {
8420 primop = primop1;
8421 unsignedp = unsignedp1;
8422 constant = tree_low_cst (primop0, 0);
8423 }
8424 else
8425 {
8426 primop = primop0;
8427 unsignedp = unsignedp0;
8428 constant = tree_low_cst (primop1, 0);
8429 }
8430
8431 bits = TYPE_PRECISION (TREE_TYPE (primop));
8432 if (bits < TYPE_PRECISION (result_type)
8433 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
8434 {
8435 mask = (~(HOST_WIDE_INT) 0) << bits;
8436 if ((mask & constant) != mask)
8437 warning (0, "comparison of promoted ~unsigned with constant");
8438 }
8439 }
8440 else if (unsignedp0 && unsignedp1
8441 && (TYPE_PRECISION (TREE_TYPE (primop0))
8442 < TYPE_PRECISION (result_type))
8443 && (TYPE_PRECISION (TREE_TYPE (primop1))
8444 < TYPE_PRECISION (result_type)))
8445 warning (0, "comparison of promoted ~unsigned with unsigned");
8446 }
8447 }
8448 }
8449 }
8450
8451 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8452 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8453 Then the expression will be built.
8454 It will be given type FINAL_TYPE if that is nonzero;
8455 otherwise, it will be given type RESULT_TYPE. */
8456
8457 if (!result_type)
8458 {
8459 binary_op_error (code);
8460 return error_mark_node;
8461 }
8462
8463 if (!converted)
8464 {
8465 if (TREE_TYPE (op0) != result_type)
8466 op0 = convert_and_check (result_type, op0);
8467 if (TREE_TYPE (op1) != result_type)
8468 op1 = convert_and_check (result_type, op1);
8469
8470 /* This can happen if one operand has a vector type, and the other
8471 has a different type. */
8472 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8473 return error_mark_node;
8474 }
8475
8476 if (build_type == NULL_TREE)
8477 build_type = result_type;
8478
8479 {
8480 /* Treat expressions in initializers specially as they can't trap. */
8481 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8482 build_type,
8483 op0, op1)
8484 : fold_build2 (resultcode, build_type,
8485 op0, op1);
8486
8487 if (final_type != 0)
8488 result = convert (final_type, result);
8489 return result;
8490 }
8491 }
8492
8493
8494 /* Convert EXPR to be a truth-value, validating its type for this
8495 purpose. */
8496
8497 tree
8498 c_objc_common_truthvalue_conversion (tree expr)
8499 {
8500 switch (TREE_CODE (TREE_TYPE (expr)))
8501 {
8502 case ARRAY_TYPE:
8503 error ("used array that cannot be converted to pointer where scalar is required");
8504 return error_mark_node;
8505
8506 case RECORD_TYPE:
8507 error ("used struct type value where scalar is required");
8508 return error_mark_node;
8509
8510 case UNION_TYPE:
8511 error ("used union type value where scalar is required");
8512 return error_mark_node;
8513
8514 case FUNCTION_TYPE:
8515 gcc_unreachable ();
8516
8517 default:
8518 break;
8519 }
8520
8521 /* ??? Should we also give an error for void and vectors rather than
8522 leaving those to give errors later? */
8523 return c_common_truthvalue_conversion (expr);
8524 }
8525 \f
8526
8527 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8528 required. */
8529
8530 tree
8531 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
8532 bool *ti ATTRIBUTE_UNUSED, bool *se)
8533 {
8534 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8535 {
8536 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8537 /* Executing a compound literal inside a function reinitializes
8538 it. */
8539 if (!TREE_STATIC (decl))
8540 *se = true;
8541 return decl;
8542 }
8543 else
8544 return expr;
8545 }
8546 \f
8547 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8548
8549 tree
8550 c_begin_omp_parallel (void)
8551 {
8552 tree block;
8553
8554 keep_next_level ();
8555 block = c_begin_compound_stmt (true);
8556
8557 return block;
8558 }
8559
8560 tree
8561 c_finish_omp_parallel (tree clauses, tree block)
8562 {
8563 tree stmt;
8564
8565 block = c_end_compound_stmt (block, true);
8566
8567 stmt = make_node (OMP_PARALLEL);
8568 TREE_TYPE (stmt) = void_type_node;
8569 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8570 OMP_PARALLEL_BODY (stmt) = block;
8571
8572 return add_stmt (stmt);
8573 }
8574
8575 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8576 Remove any elements from the list that are invalid. */
8577
8578 tree
8579 c_finish_omp_clauses (tree clauses)
8580 {
8581 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8582 tree c, t, *pc = &clauses;
8583 const char *name;
8584
8585 bitmap_obstack_initialize (NULL);
8586 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8587 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8588 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8589
8590 for (pc = &clauses, c = clauses; c ; c = *pc)
8591 {
8592 bool remove = false;
8593 bool need_complete = false;
8594 bool need_implicitly_determined = false;
8595
8596 switch (OMP_CLAUSE_CODE (c))
8597 {
8598 case OMP_CLAUSE_SHARED:
8599 name = "shared";
8600 need_implicitly_determined = true;
8601 goto check_dup_generic;
8602
8603 case OMP_CLAUSE_PRIVATE:
8604 name = "private";
8605 need_complete = true;
8606 need_implicitly_determined = true;
8607 goto check_dup_generic;
8608
8609 case OMP_CLAUSE_REDUCTION:
8610 name = "reduction";
8611 need_implicitly_determined = true;
8612 t = OMP_CLAUSE_DECL (c);
8613 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8614 || POINTER_TYPE_P (TREE_TYPE (t)))
8615 {
8616 error ("%qE has invalid type for %<reduction%>", t);
8617 remove = true;
8618 }
8619 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8620 {
8621 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8622 const char *r_name = NULL;
8623
8624 switch (r_code)
8625 {
8626 case PLUS_EXPR:
8627 case MULT_EXPR:
8628 case MINUS_EXPR:
8629 break;
8630 case BIT_AND_EXPR:
8631 r_name = "&";
8632 break;
8633 case BIT_XOR_EXPR:
8634 r_name = "^";
8635 break;
8636 case BIT_IOR_EXPR:
8637 r_name = "|";
8638 break;
8639 case TRUTH_ANDIF_EXPR:
8640 r_name = "&&";
8641 break;
8642 case TRUTH_ORIF_EXPR:
8643 r_name = "||";
8644 break;
8645 default:
8646 gcc_unreachable ();
8647 }
8648 if (r_name)
8649 {
8650 error ("%qE has invalid type for %<reduction(%s)%>",
8651 t, r_name);
8652 remove = true;
8653 }
8654 }
8655 goto check_dup_generic;
8656
8657 case OMP_CLAUSE_COPYPRIVATE:
8658 name = "copyprivate";
8659 goto check_dup_generic;
8660
8661 case OMP_CLAUSE_COPYIN:
8662 name = "copyin";
8663 t = OMP_CLAUSE_DECL (c);
8664 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8665 {
8666 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8667 remove = true;
8668 }
8669 goto check_dup_generic;
8670
8671 check_dup_generic:
8672 t = OMP_CLAUSE_DECL (c);
8673 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8674 {
8675 error ("%qE is not a variable in clause %qs", t, name);
8676 remove = true;
8677 }
8678 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8679 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8680 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8681 {
8682 error ("%qE appears more than once in data clauses", t);
8683 remove = true;
8684 }
8685 else
8686 bitmap_set_bit (&generic_head, DECL_UID (t));
8687 break;
8688
8689 case OMP_CLAUSE_FIRSTPRIVATE:
8690 name = "firstprivate";
8691 t = OMP_CLAUSE_DECL (c);
8692 need_complete = true;
8693 need_implicitly_determined = true;
8694 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8695 {
8696 error ("%qE is not a variable in clause %<firstprivate%>", t);
8697 remove = true;
8698 }
8699 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8700 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8701 {
8702 error ("%qE appears more than once in data clauses", t);
8703 remove = true;
8704 }
8705 else
8706 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8707 break;
8708
8709 case OMP_CLAUSE_LASTPRIVATE:
8710 name = "lastprivate";
8711 t = OMP_CLAUSE_DECL (c);
8712 need_complete = true;
8713 need_implicitly_determined = true;
8714 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8715 {
8716 error ("%qE is not a variable in clause %<lastprivate%>", t);
8717 remove = true;
8718 }
8719 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8720 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8721 {
8722 error ("%qE appears more than once in data clauses", t);
8723 remove = true;
8724 }
8725 else
8726 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8727 break;
8728
8729 case OMP_CLAUSE_IF:
8730 case OMP_CLAUSE_NUM_THREADS:
8731 case OMP_CLAUSE_SCHEDULE:
8732 case OMP_CLAUSE_NOWAIT:
8733 case OMP_CLAUSE_ORDERED:
8734 case OMP_CLAUSE_DEFAULT:
8735 pc = &OMP_CLAUSE_CHAIN (c);
8736 continue;
8737
8738 default:
8739 gcc_unreachable ();
8740 }
8741
8742 if (!remove)
8743 {
8744 t = OMP_CLAUSE_DECL (c);
8745
8746 if (need_complete)
8747 {
8748 t = require_complete_type (t);
8749 if (t == error_mark_node)
8750 remove = true;
8751 }
8752
8753 if (need_implicitly_determined)
8754 {
8755 const char *share_name = NULL;
8756
8757 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8758 share_name = "threadprivate";
8759 else switch (c_omp_predetermined_sharing (t))
8760 {
8761 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8762 break;
8763 case OMP_CLAUSE_DEFAULT_SHARED:
8764 share_name = "shared";
8765 break;
8766 case OMP_CLAUSE_DEFAULT_PRIVATE:
8767 share_name = "private";
8768 break;
8769 default:
8770 gcc_unreachable ();
8771 }
8772 if (share_name)
8773 {
8774 error ("%qE is predetermined %qs for %qs",
8775 t, share_name, name);
8776 remove = true;
8777 }
8778 }
8779 }
8780
8781 if (remove)
8782 *pc = OMP_CLAUSE_CHAIN (c);
8783 else
8784 pc = &OMP_CLAUSE_CHAIN (c);
8785 }
8786
8787 bitmap_obstack_release (NULL);
8788 return clauses;
8789 }
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