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* sv.po: Update.
[official-gcc.git] / gcc / c-typeck.c
blob89bfed1db64bf1ba0507e85321a206c80b4efc13
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 && !flag_isoc99
4723 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4724 {
4725 /* As an extension, allow initializing objects with static storage
4726 duration with compound literals (which are then treated just as
4727 the brace enclosed list they contain). */
4728 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4729 inside_init = DECL_INITIAL (decl);
4730 }
4731
4732 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4733 && TREE_CODE (inside_init) != CONSTRUCTOR)
4734 {
4735 error_init ("array initialized from non-constant array expression");
4736 return error_mark_node;
4737 }
4738
4739 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4740 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4741
4742 /* Compound expressions can only occur here if -pedantic or
4743 -pedantic-errors is specified. In the later case, we always want
4744 an error. In the former case, we simply want a warning. */
4745 if (require_constant && pedantic
4746 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4747 {
4748 inside_init
4749 = valid_compound_expr_initializer (inside_init,
4750 TREE_TYPE (inside_init));
4751 if (inside_init == error_mark_node)
4752 error_init ("initializer element is not constant");
4753 else
4754 pedwarn_init ("initializer element is not constant");
4755 if (flag_pedantic_errors)
4756 inside_init = error_mark_node;
4757 }
4758 else if (require_constant
4759 && !initializer_constant_valid_p (inside_init,
4760 TREE_TYPE (inside_init)))
4761 {
4762 error_init ("initializer element is not constant");
4763 inside_init = error_mark_node;
4764 }
4765
4766 /* Added to enable additional -Wmissing-format-attribute warnings. */
4767 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4768 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4769 NULL_TREE, 0);
4770 return inside_init;
4771 }
4772
4773 /* Handle scalar types, including conversions. */
4774
4775 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4776 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE
4777 || code == VECTOR_TYPE)
4778 {
4779 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4780 && (TREE_CODE (init) == STRING_CST
4781 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4782 init = array_to_pointer_conversion (init);
4783 inside_init
4784 = convert_for_assignment (type, init, ic_init,
4785 NULL_TREE, NULL_TREE, 0);
4786
4787 /* Check to see if we have already given an error message. */
4788 if (inside_init == error_mark_node)
4789 ;
4790 else if (require_constant && !TREE_CONSTANT (inside_init))
4791 {
4792 error_init ("initializer element is not constant");
4793 inside_init = error_mark_node;
4794 }
4795 else if (require_constant
4796 && !initializer_constant_valid_p (inside_init,
4797 TREE_TYPE (inside_init)))
4798 {
4799 error_init ("initializer element is not computable at load time");
4800 inside_init = error_mark_node;
4801 }
4802
4803 return inside_init;
4804 }
4805
4806 /* Come here only for records and arrays. */
4807
4808 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4809 {
4810 error_init ("variable-sized object may not be initialized");
4811 return error_mark_node;
4812 }
4813
4814 error_init ("invalid initializer");
4815 return error_mark_node;
4816 }
4817 \f
4818 /* Handle initializers that use braces. */
4819
4820 /* Type of object we are accumulating a constructor for.
4821 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4822 static tree constructor_type;
4823
4824 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4825 left to fill. */
4826 static tree constructor_fields;
4827
4828 /* For an ARRAY_TYPE, this is the specified index
4829 at which to store the next element we get. */
4830 static tree constructor_index;
4831
4832 /* For an ARRAY_TYPE, this is the maximum index. */
4833 static tree constructor_max_index;
4834
4835 /* For a RECORD_TYPE, this is the first field not yet written out. */
4836 static tree constructor_unfilled_fields;
4837
4838 /* For an ARRAY_TYPE, this is the index of the first element
4839 not yet written out. */
4840 static tree constructor_unfilled_index;
4841
4842 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4843 This is so we can generate gaps between fields, when appropriate. */
4844 static tree constructor_bit_index;
4845
4846 /* If we are saving up the elements rather than allocating them,
4847 this is the list of elements so far (in reverse order,
4848 most recent first). */
4849 static VEC(constructor_elt,gc) *constructor_elements;
4850
4851 /* 1 if constructor should be incrementally stored into a constructor chain,
4852 0 if all the elements should be kept in AVL tree. */
4853 static int constructor_incremental;
4854
4855 /* 1 if so far this constructor's elements are all compile-time constants. */
4856 static int constructor_constant;
4857
4858 /* 1 if so far this constructor's elements are all valid address constants. */
4859 static int constructor_simple;
4860
4861 /* 1 if this constructor is erroneous so far. */
4862 static int constructor_erroneous;
4863
4864 /* Structure for managing pending initializer elements, organized as an
4865 AVL tree. */
4866
4867 struct init_node
4868 {
4869 struct init_node *left, *right;
4870 struct init_node *parent;
4871 int balance;
4872 tree purpose;
4873 tree value;
4874 };
4875
4876 /* Tree of pending elements at this constructor level.
4877 These are elements encountered out of order
4878 which belong at places we haven't reached yet in actually
4879 writing the output.
4880 Will never hold tree nodes across GC runs. */
4881 static struct init_node *constructor_pending_elts;
4882
4883 /* The SPELLING_DEPTH of this constructor. */
4884 static int constructor_depth;
4885
4886 /* DECL node for which an initializer is being read.
4887 0 means we are reading a constructor expression
4888 such as (struct foo) {...}. */
4889 static tree constructor_decl;
4890
4891 /* Nonzero if this is an initializer for a top-level decl. */
4892 static int constructor_top_level;
4893
4894 /* Nonzero if there were any member designators in this initializer. */
4895 static int constructor_designated;
4896
4897 /* Nesting depth of designator list. */
4898 static int designator_depth;
4899
4900 /* Nonzero if there were diagnosed errors in this designator list. */
4901 static int designator_erroneous;
4902
4903 \f
4904 /* This stack has a level for each implicit or explicit level of
4905 structuring in the initializer, including the outermost one. It
4906 saves the values of most of the variables above. */
4907
4908 struct constructor_range_stack;
4909
4910 struct constructor_stack
4911 {
4912 struct constructor_stack *next;
4913 tree type;
4914 tree fields;
4915 tree index;
4916 tree max_index;
4917 tree unfilled_index;
4918 tree unfilled_fields;
4919 tree bit_index;
4920 VEC(constructor_elt,gc) *elements;
4921 struct init_node *pending_elts;
4922 int offset;
4923 int depth;
4924 /* If value nonzero, this value should replace the entire
4925 constructor at this level. */
4926 struct c_expr replacement_value;
4927 struct constructor_range_stack *range_stack;
4928 char constant;
4929 char simple;
4930 char implicit;
4931 char erroneous;
4932 char outer;
4933 char incremental;
4934 char designated;
4935 };
4936
4937 static struct constructor_stack *constructor_stack;
4938
4939 /* This stack represents designators from some range designator up to
4940 the last designator in the list. */
4941
4942 struct constructor_range_stack
4943 {
4944 struct constructor_range_stack *next, *prev;
4945 struct constructor_stack *stack;
4946 tree range_start;
4947 tree index;
4948 tree range_end;
4949 tree fields;
4950 };
4951
4952 static struct constructor_range_stack *constructor_range_stack;
4953
4954 /* This stack records separate initializers that are nested.
4955 Nested initializers can't happen in ANSI C, but GNU C allows them
4956 in cases like { ... (struct foo) { ... } ... }. */
4957
4958 struct initializer_stack
4959 {
4960 struct initializer_stack *next;
4961 tree decl;
4962 struct constructor_stack *constructor_stack;
4963 struct constructor_range_stack *constructor_range_stack;
4964 VEC(constructor_elt,gc) *elements;
4965 struct spelling *spelling;
4966 struct spelling *spelling_base;
4967 int spelling_size;
4968 char top_level;
4969 char require_constant_value;
4970 char require_constant_elements;
4971 };
4972
4973 static struct initializer_stack *initializer_stack;
4974 \f
4975 /* Prepare to parse and output the initializer for variable DECL. */
4976
4977 void
4978 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
4979 {
4980 const char *locus;
4981 struct initializer_stack *p = XNEW (struct initializer_stack);
4982
4983 p->decl = constructor_decl;
4984 p->require_constant_value = require_constant_value;
4985 p->require_constant_elements = require_constant_elements;
4986 p->constructor_stack = constructor_stack;
4987 p->constructor_range_stack = constructor_range_stack;
4988 p->elements = constructor_elements;
4989 p->spelling = spelling;
4990 p->spelling_base = spelling_base;
4991 p->spelling_size = spelling_size;
4992 p->top_level = constructor_top_level;
4993 p->next = initializer_stack;
4994 initializer_stack = p;
4995
4996 constructor_decl = decl;
4997 constructor_designated = 0;
4998 constructor_top_level = top_level;
4999
5000 if (decl != 0 && decl != error_mark_node)
5001 {
5002 require_constant_value = TREE_STATIC (decl);
5003 require_constant_elements
5004 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5005 /* For a scalar, you can always use any value to initialize,
5006 even within braces. */
5007 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5008 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5009 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5010 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5011 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5012 }
5013 else
5014 {
5015 require_constant_value = 0;
5016 require_constant_elements = 0;
5017 locus = "(anonymous)";
5018 }
5019
5020 constructor_stack = 0;
5021 constructor_range_stack = 0;
5022
5023 missing_braces_mentioned = 0;
5024
5025 spelling_base = 0;
5026 spelling_size = 0;
5027 RESTORE_SPELLING_DEPTH (0);
5028
5029 if (locus)
5030 push_string (locus);
5031 }
5032
5033 void
5034 finish_init (void)
5035 {
5036 struct initializer_stack *p = initializer_stack;
5037
5038 /* Free the whole constructor stack of this initializer. */
5039 while (constructor_stack)
5040 {
5041 struct constructor_stack *q = constructor_stack;
5042 constructor_stack = q->next;
5043 free (q);
5044 }
5045
5046 gcc_assert (!constructor_range_stack);
5047
5048 /* Pop back to the data of the outer initializer (if any). */
5049 free (spelling_base);
5050
5051 constructor_decl = p->decl;
5052 require_constant_value = p->require_constant_value;
5053 require_constant_elements = p->require_constant_elements;
5054 constructor_stack = p->constructor_stack;
5055 constructor_range_stack = p->constructor_range_stack;
5056 constructor_elements = p->elements;
5057 spelling = p->spelling;
5058 spelling_base = p->spelling_base;
5059 spelling_size = p->spelling_size;
5060 constructor_top_level = p->top_level;
5061 initializer_stack = p->next;
5062 free (p);
5063 }
5064 \f
5065 /* Call here when we see the initializer is surrounded by braces.
5066 This is instead of a call to push_init_level;
5067 it is matched by a call to pop_init_level.
5068
5069 TYPE is the type to initialize, for a constructor expression.
5070 For an initializer for a decl, TYPE is zero. */
5071
5072 void
5073 really_start_incremental_init (tree type)
5074 {
5075 struct constructor_stack *p = XNEW (struct constructor_stack);
5076
5077 if (type == 0)
5078 type = TREE_TYPE (constructor_decl);
5079
5080 if (targetm.vector_opaque_p (type))
5081 error ("opaque vector types cannot be initialized");
5082
5083 p->type = constructor_type;
5084 p->fields = constructor_fields;
5085 p->index = constructor_index;
5086 p->max_index = constructor_max_index;
5087 p->unfilled_index = constructor_unfilled_index;
5088 p->unfilled_fields = constructor_unfilled_fields;
5089 p->bit_index = constructor_bit_index;
5090 p->elements = constructor_elements;
5091 p->constant = constructor_constant;
5092 p->simple = constructor_simple;
5093 p->erroneous = constructor_erroneous;
5094 p->pending_elts = constructor_pending_elts;
5095 p->depth = constructor_depth;
5096 p->replacement_value.value = 0;
5097 p->replacement_value.original_code = ERROR_MARK;
5098 p->implicit = 0;
5099 p->range_stack = 0;
5100 p->outer = 0;
5101 p->incremental = constructor_incremental;
5102 p->designated = constructor_designated;
5103 p->next = 0;
5104 constructor_stack = p;
5105
5106 constructor_constant = 1;
5107 constructor_simple = 1;
5108 constructor_depth = SPELLING_DEPTH ();
5109 constructor_elements = 0;
5110 constructor_pending_elts = 0;
5111 constructor_type = type;
5112 constructor_incremental = 1;
5113 constructor_designated = 0;
5114 designator_depth = 0;
5115 designator_erroneous = 0;
5116
5117 if (TREE_CODE (constructor_type) == RECORD_TYPE
5118 || TREE_CODE (constructor_type) == UNION_TYPE)
5119 {
5120 constructor_fields = TYPE_FIELDS (constructor_type);
5121 /* Skip any nameless bit fields at the beginning. */
5122 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5123 && DECL_NAME (constructor_fields) == 0)
5124 constructor_fields = TREE_CHAIN (constructor_fields);
5125
5126 constructor_unfilled_fields = constructor_fields;
5127 constructor_bit_index = bitsize_zero_node;
5128 }
5129 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5130 {
5131 if (TYPE_DOMAIN (constructor_type))
5132 {
5133 constructor_max_index
5134 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5135
5136 /* Detect non-empty initializations of zero-length arrays. */
5137 if (constructor_max_index == NULL_TREE
5138 && TYPE_SIZE (constructor_type))
5139 constructor_max_index = build_int_cst (NULL_TREE, -1);
5140
5141 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5142 to initialize VLAs will cause a proper error; avoid tree
5143 checking errors as well by setting a safe value. */
5144 if (constructor_max_index
5145 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5146 constructor_max_index = build_int_cst (NULL_TREE, -1);
5147
5148 constructor_index
5149 = convert (bitsizetype,
5150 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5151 }
5152 else
5153 {
5154 constructor_index = bitsize_zero_node;
5155 constructor_max_index = NULL_TREE;
5156 }
5157
5158 constructor_unfilled_index = constructor_index;
5159 }
5160 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5161 {
5162 /* Vectors are like simple fixed-size arrays. */
5163 constructor_max_index =
5164 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5165 constructor_index = bitsize_zero_node;
5166 constructor_unfilled_index = constructor_index;
5167 }
5168 else
5169 {
5170 /* Handle the case of int x = {5}; */
5171 constructor_fields = constructor_type;
5172 constructor_unfilled_fields = constructor_type;
5173 }
5174 }
5175 \f
5176 /* Push down into a subobject, for initialization.
5177 If this is for an explicit set of braces, IMPLICIT is 0.
5178 If it is because the next element belongs at a lower level,
5179 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5180
5181 void
5182 push_init_level (int implicit)
5183 {
5184 struct constructor_stack *p;
5185 tree value = NULL_TREE;
5186
5187 /* If we've exhausted any levels that didn't have braces,
5188 pop them now. If implicit == 1, this will have been done in
5189 process_init_element; do not repeat it here because in the case
5190 of excess initializers for an empty aggregate this leads to an
5191 infinite cycle of popping a level and immediately recreating
5192 it. */
5193 if (implicit != 1)
5194 {
5195 while (constructor_stack->implicit)
5196 {
5197 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5198 || TREE_CODE (constructor_type) == UNION_TYPE)
5199 && constructor_fields == 0)
5200 process_init_element (pop_init_level (1));
5201 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5202 && constructor_max_index
5203 && tree_int_cst_lt (constructor_max_index,
5204 constructor_index))
5205 process_init_element (pop_init_level (1));
5206 else
5207 break;
5208 }
5209 }
5210
5211 /* Unless this is an explicit brace, we need to preserve previous
5212 content if any. */
5213 if (implicit)
5214 {
5215 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5216 || TREE_CODE (constructor_type) == UNION_TYPE)
5217 && constructor_fields)
5218 value = find_init_member (constructor_fields);
5219 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5220 value = find_init_member (constructor_index);
5221 }
5222
5223 p = XNEW (struct constructor_stack);
5224 p->type = constructor_type;
5225 p->fields = constructor_fields;
5226 p->index = constructor_index;
5227 p->max_index = constructor_max_index;
5228 p->unfilled_index = constructor_unfilled_index;
5229 p->unfilled_fields = constructor_unfilled_fields;
5230 p->bit_index = constructor_bit_index;
5231 p->elements = constructor_elements;
5232 p->constant = constructor_constant;
5233 p->simple = constructor_simple;
5234 p->erroneous = constructor_erroneous;
5235 p->pending_elts = constructor_pending_elts;
5236 p->depth = constructor_depth;
5237 p->replacement_value.value = 0;
5238 p->replacement_value.original_code = ERROR_MARK;
5239 p->implicit = implicit;
5240 p->outer = 0;
5241 p->incremental = constructor_incremental;
5242 p->designated = constructor_designated;
5243 p->next = constructor_stack;
5244 p->range_stack = 0;
5245 constructor_stack = p;
5246
5247 constructor_constant = 1;
5248 constructor_simple = 1;
5249 constructor_depth = SPELLING_DEPTH ();
5250 constructor_elements = 0;
5251 constructor_incremental = 1;
5252 constructor_designated = 0;
5253 constructor_pending_elts = 0;
5254 if (!implicit)
5255 {
5256 p->range_stack = constructor_range_stack;
5257 constructor_range_stack = 0;
5258 designator_depth = 0;
5259 designator_erroneous = 0;
5260 }
5261
5262 /* Don't die if an entire brace-pair level is superfluous
5263 in the containing level. */
5264 if (constructor_type == 0)
5265 ;
5266 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5267 || TREE_CODE (constructor_type) == UNION_TYPE)
5268 {
5269 /* Don't die if there are extra init elts at the end. */
5270 if (constructor_fields == 0)
5271 constructor_type = 0;
5272 else
5273 {
5274 constructor_type = TREE_TYPE (constructor_fields);
5275 push_member_name (constructor_fields);
5276 constructor_depth++;
5277 }
5278 }
5279 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5280 {
5281 constructor_type = TREE_TYPE (constructor_type);
5282 push_array_bounds (tree_low_cst (constructor_index, 1));
5283 constructor_depth++;
5284 }
5285
5286 if (constructor_type == 0)
5287 {
5288 error_init ("extra brace group at end of initializer");
5289 constructor_fields = 0;
5290 constructor_unfilled_fields = 0;
5291 return;
5292 }
5293
5294 if (value && TREE_CODE (value) == CONSTRUCTOR)
5295 {
5296 constructor_constant = TREE_CONSTANT (value);
5297 constructor_simple = TREE_STATIC (value);
5298 constructor_elements = CONSTRUCTOR_ELTS (value);
5299 if (!VEC_empty (constructor_elt, constructor_elements)
5300 && (TREE_CODE (constructor_type) == RECORD_TYPE
5301 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5302 set_nonincremental_init ();
5303 }
5304
5305 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5306 {
5307 missing_braces_mentioned = 1;
5308 warning_init ("missing braces around initializer");
5309 }
5310
5311 if (TREE_CODE (constructor_type) == RECORD_TYPE
5312 || TREE_CODE (constructor_type) == UNION_TYPE)
5313 {
5314 constructor_fields = TYPE_FIELDS (constructor_type);
5315 /* Skip any nameless bit fields at the beginning. */
5316 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5317 && DECL_NAME (constructor_fields) == 0)
5318 constructor_fields = TREE_CHAIN (constructor_fields);
5319
5320 constructor_unfilled_fields = constructor_fields;
5321 constructor_bit_index = bitsize_zero_node;
5322 }
5323 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5324 {
5325 /* Vectors are like simple fixed-size arrays. */
5326 constructor_max_index =
5327 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5328 constructor_index = convert (bitsizetype, integer_zero_node);
5329 constructor_unfilled_index = constructor_index;
5330 }
5331 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5332 {
5333 if (TYPE_DOMAIN (constructor_type))
5334 {
5335 constructor_max_index
5336 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5337
5338 /* Detect non-empty initializations of zero-length arrays. */
5339 if (constructor_max_index == NULL_TREE
5340 && TYPE_SIZE (constructor_type))
5341 constructor_max_index = build_int_cst (NULL_TREE, -1);
5342
5343 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5344 to initialize VLAs will cause a proper error; avoid tree
5345 checking errors as well by setting a safe value. */
5346 if (constructor_max_index
5347 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5348 constructor_max_index = build_int_cst (NULL_TREE, -1);
5349
5350 constructor_index
5351 = convert (bitsizetype,
5352 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5353 }
5354 else
5355 constructor_index = bitsize_zero_node;
5356
5357 constructor_unfilled_index = constructor_index;
5358 if (value && TREE_CODE (value) == STRING_CST)
5359 {
5360 /* We need to split the char/wchar array into individual
5361 characters, so that we don't have to special case it
5362 everywhere. */
5363 set_nonincremental_init_from_string (value);
5364 }
5365 }
5366 else
5367 {
5368 if (constructor_type != error_mark_node)
5369 warning_init ("braces around scalar initializer");
5370 constructor_fields = constructor_type;
5371 constructor_unfilled_fields = constructor_type;
5372 }
5373 }
5374
5375 /* At the end of an implicit or explicit brace level,
5376 finish up that level of constructor. If a single expression
5377 with redundant braces initialized that level, return the
5378 c_expr structure for that expression. Otherwise, the original_code
5379 element is set to ERROR_MARK.
5380 If we were outputting the elements as they are read, return 0 as the value
5381 from inner levels (process_init_element ignores that),
5382 but return error_mark_node as the value from the outermost level
5383 (that's what we want to put in DECL_INITIAL).
5384 Otherwise, return a CONSTRUCTOR expression as the value. */
5385
5386 struct c_expr
5387 pop_init_level (int implicit)
5388 {
5389 struct constructor_stack *p;
5390 struct c_expr ret;
5391 ret.value = 0;
5392 ret.original_code = ERROR_MARK;
5393
5394 if (implicit == 0)
5395 {
5396 /* When we come to an explicit close brace,
5397 pop any inner levels that didn't have explicit braces. */
5398 while (constructor_stack->implicit)
5399 process_init_element (pop_init_level (1));
5400
5401 gcc_assert (!constructor_range_stack);
5402 }
5403
5404 /* Now output all pending elements. */
5405 constructor_incremental = 1;
5406 output_pending_init_elements (1);
5407
5408 p = constructor_stack;
5409
5410 /* Error for initializing a flexible array member, or a zero-length
5411 array member in an inappropriate context. */
5412 if (constructor_type && constructor_fields
5413 && TREE_CODE (constructor_type) == ARRAY_TYPE
5414 && TYPE_DOMAIN (constructor_type)
5415 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5416 {
5417 /* Silently discard empty initializations. The parser will
5418 already have pedwarned for empty brackets. */
5419 if (integer_zerop (constructor_unfilled_index))
5420 constructor_type = NULL_TREE;
5421 else
5422 {
5423 gcc_assert (!TYPE_SIZE (constructor_type));
5424
5425 if (constructor_depth > 2)
5426 error_init ("initialization of flexible array member in a nested context");
5427 else if (pedantic)
5428 pedwarn_init ("initialization of a flexible array member");
5429
5430 /* We have already issued an error message for the existence
5431 of a flexible array member not at the end of the structure.
5432 Discard the initializer so that we do not die later. */
5433 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5434 constructor_type = NULL_TREE;
5435 }
5436 }
5437
5438 /* Warn when some struct elements are implicitly initialized to zero. */
5439 if (warn_missing_field_initializers
5440 && constructor_type
5441 && TREE_CODE (constructor_type) == RECORD_TYPE
5442 && constructor_unfilled_fields)
5443 {
5444 /* Do not warn for flexible array members or zero-length arrays. */
5445 while (constructor_unfilled_fields
5446 && (!DECL_SIZE (constructor_unfilled_fields)
5447 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5448 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5449
5450 /* Do not warn if this level of the initializer uses member
5451 designators; it is likely to be deliberate. */
5452 if (constructor_unfilled_fields && !constructor_designated)
5453 {
5454 push_member_name (constructor_unfilled_fields);
5455 warning_init ("missing initializer");
5456 RESTORE_SPELLING_DEPTH (constructor_depth);
5457 }
5458 }
5459
5460 /* Pad out the end of the structure. */
5461 if (p->replacement_value.value)
5462 /* If this closes a superfluous brace pair,
5463 just pass out the element between them. */
5464 ret = p->replacement_value;
5465 else if (constructor_type == 0)
5466 ;
5467 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5468 && TREE_CODE (constructor_type) != UNION_TYPE
5469 && TREE_CODE (constructor_type) != ARRAY_TYPE
5470 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5471 {
5472 /* A nonincremental scalar initializer--just return
5473 the element, after verifying there is just one. */
5474 if (VEC_empty (constructor_elt,constructor_elements))
5475 {
5476 if (!constructor_erroneous)
5477 error_init ("empty scalar initializer");
5478 ret.value = error_mark_node;
5479 }
5480 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5481 {
5482 error_init ("extra elements in scalar initializer");
5483 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5484 }
5485 else
5486 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5487 }
5488 else
5489 {
5490 if (constructor_erroneous)
5491 ret.value = error_mark_node;
5492 else
5493 {
5494 ret.value = build_constructor (constructor_type,
5495 constructor_elements);
5496 if (constructor_constant)
5497 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1;
5498 if (constructor_constant && constructor_simple)
5499 TREE_STATIC (ret.value) = 1;
5500 }
5501 }
5502
5503 constructor_type = p->type;
5504 constructor_fields = p->fields;
5505 constructor_index = p->index;
5506 constructor_max_index = p->max_index;
5507 constructor_unfilled_index = p->unfilled_index;
5508 constructor_unfilled_fields = p->unfilled_fields;
5509 constructor_bit_index = p->bit_index;
5510 constructor_elements = p->elements;
5511 constructor_constant = p->constant;
5512 constructor_simple = p->simple;
5513 constructor_erroneous = p->erroneous;
5514 constructor_incremental = p->incremental;
5515 constructor_designated = p->designated;
5516 constructor_pending_elts = p->pending_elts;
5517 constructor_depth = p->depth;
5518 if (!p->implicit)
5519 constructor_range_stack = p->range_stack;
5520 RESTORE_SPELLING_DEPTH (constructor_depth);
5521
5522 constructor_stack = p->next;
5523 free (p);
5524
5525 if (ret.value == 0 && constructor_stack == 0)
5526 ret.value = error_mark_node;
5527 return ret;
5528 }
5529
5530 /* Common handling for both array range and field name designators.
5531 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5532
5533 static int
5534 set_designator (int array)
5535 {
5536 tree subtype;
5537 enum tree_code subcode;
5538
5539 /* Don't die if an entire brace-pair level is superfluous
5540 in the containing level. */
5541 if (constructor_type == 0)
5542 return 1;
5543
5544 /* If there were errors in this designator list already, bail out
5545 silently. */
5546 if (designator_erroneous)
5547 return 1;
5548
5549 if (!designator_depth)
5550 {
5551 gcc_assert (!constructor_range_stack);
5552
5553 /* Designator list starts at the level of closest explicit
5554 braces. */
5555 while (constructor_stack->implicit)
5556 process_init_element (pop_init_level (1));
5557 constructor_designated = 1;
5558 return 0;
5559 }
5560
5561 switch (TREE_CODE (constructor_type))
5562 {
5563 case RECORD_TYPE:
5564 case UNION_TYPE:
5565 subtype = TREE_TYPE (constructor_fields);
5566 if (subtype != error_mark_node)
5567 subtype = TYPE_MAIN_VARIANT (subtype);
5568 break;
5569 case ARRAY_TYPE:
5570 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5571 break;
5572 default:
5573 gcc_unreachable ();
5574 }
5575
5576 subcode = TREE_CODE (subtype);
5577 if (array && subcode != ARRAY_TYPE)
5578 {
5579 error_init ("array index in non-array initializer");
5580 return 1;
5581 }
5582 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5583 {
5584 error_init ("field name not in record or union initializer");
5585 return 1;
5586 }
5587
5588 constructor_designated = 1;
5589 push_init_level (2);
5590 return 0;
5591 }
5592
5593 /* If there are range designators in designator list, push a new designator
5594 to constructor_range_stack. RANGE_END is end of such stack range or
5595 NULL_TREE if there is no range designator at this level. */
5596
5597 static void
5598 push_range_stack (tree range_end)
5599 {
5600 struct constructor_range_stack *p;
5601
5602 p = GGC_NEW (struct constructor_range_stack);
5603 p->prev = constructor_range_stack;
5604 p->next = 0;
5605 p->fields = constructor_fields;
5606 p->range_start = constructor_index;
5607 p->index = constructor_index;
5608 p->stack = constructor_stack;
5609 p->range_end = range_end;
5610 if (constructor_range_stack)
5611 constructor_range_stack->next = p;
5612 constructor_range_stack = p;
5613 }
5614
5615 /* Within an array initializer, specify the next index to be initialized.
5616 FIRST is that index. If LAST is nonzero, then initialize a range
5617 of indices, running from FIRST through LAST. */
5618
5619 void
5620 set_init_index (tree first, tree last)
5621 {
5622 if (set_designator (1))
5623 return;
5624
5625 designator_erroneous = 1;
5626
5627 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5628 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5629 {
5630 error_init ("array index in initializer not of integer type");
5631 return;
5632 }
5633
5634 if (TREE_CODE (first) != INTEGER_CST)
5635 error_init ("nonconstant array index in initializer");
5636 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5637 error_init ("nonconstant array index in initializer");
5638 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5639 error_init ("array index in non-array initializer");
5640 else if (tree_int_cst_sgn (first) == -1)
5641 error_init ("array index in initializer exceeds array bounds");
5642 else if (constructor_max_index
5643 && tree_int_cst_lt (constructor_max_index, first))
5644 error_init ("array index in initializer exceeds array bounds");
5645 else
5646 {
5647 constructor_index = convert (bitsizetype, first);
5648
5649 if (last)
5650 {
5651 if (tree_int_cst_equal (first, last))
5652 last = 0;
5653 else if (tree_int_cst_lt (last, first))
5654 {
5655 error_init ("empty index range in initializer");
5656 last = 0;
5657 }
5658 else
5659 {
5660 last = convert (bitsizetype, last);
5661 if (constructor_max_index != 0
5662 && tree_int_cst_lt (constructor_max_index, last))
5663 {
5664 error_init ("array index range in initializer exceeds array bounds");
5665 last = 0;
5666 }
5667 }
5668 }
5669
5670 designator_depth++;
5671 designator_erroneous = 0;
5672 if (constructor_range_stack || last)
5673 push_range_stack (last);
5674 }
5675 }
5676
5677 /* Within a struct initializer, specify the next field to be initialized. */
5678
5679 void
5680 set_init_label (tree fieldname)
5681 {
5682 tree tail;
5683
5684 if (set_designator (0))
5685 return;
5686
5687 designator_erroneous = 1;
5688
5689 if (TREE_CODE (constructor_type) != RECORD_TYPE
5690 && TREE_CODE (constructor_type) != UNION_TYPE)
5691 {
5692 error_init ("field name not in record or union initializer");
5693 return;
5694 }
5695
5696 for (tail = TYPE_FIELDS (constructor_type); tail;
5697 tail = TREE_CHAIN (tail))
5698 {
5699 if (DECL_NAME (tail) == fieldname)
5700 break;
5701 }
5702
5703 if (tail == 0)
5704 error ("unknown field %qE specified in initializer", fieldname);
5705 else
5706 {
5707 constructor_fields = tail;
5708 designator_depth++;
5709 designator_erroneous = 0;
5710 if (constructor_range_stack)
5711 push_range_stack (NULL_TREE);
5712 }
5713 }
5714 \f
5715 /* Add a new initializer to the tree of pending initializers. PURPOSE
5716 identifies the initializer, either array index or field in a structure.
5717 VALUE is the value of that index or field. */
5718
5719 static void
5720 add_pending_init (tree purpose, tree value)
5721 {
5722 struct init_node *p, **q, *r;
5723
5724 q = &constructor_pending_elts;
5725 p = 0;
5726
5727 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5728 {
5729 while (*q != 0)
5730 {
5731 p = *q;
5732 if (tree_int_cst_lt (purpose, p->purpose))
5733 q = &p->left;
5734 else if (tree_int_cst_lt (p->purpose, purpose))
5735 q = &p->right;
5736 else
5737 {
5738 if (TREE_SIDE_EFFECTS (p->value))
5739 warning_init ("initialized field with side-effects overwritten");
5740 else if (warn_override_init)
5741 warning_init ("initialized field overwritten");
5742 p->value = value;
5743 return;
5744 }
5745 }
5746 }
5747 else
5748 {
5749 tree bitpos;
5750
5751 bitpos = bit_position (purpose);
5752 while (*q != NULL)
5753 {
5754 p = *q;
5755 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5756 q = &p->left;
5757 else if (p->purpose != purpose)
5758 q = &p->right;
5759 else
5760 {
5761 if (TREE_SIDE_EFFECTS (p->value))
5762 warning_init ("initialized field with side-effects overwritten");
5763 else if (warn_override_init)
5764 warning_init ("initialized field overwritten");
5765 p->value = value;
5766 return;
5767 }
5768 }
5769 }
5770
5771 r = GGC_NEW (struct init_node);
5772 r->purpose = purpose;
5773 r->value = value;
5774
5775 *q = r;
5776 r->parent = p;
5777 r->left = 0;
5778 r->right = 0;
5779 r->balance = 0;
5780
5781 while (p)
5782 {
5783 struct init_node *s;
5784
5785 if (r == p->left)
5786 {
5787 if (p->balance == 0)
5788 p->balance = -1;
5789 else if (p->balance < 0)
5790 {
5791 if (r->balance < 0)
5792 {
5793 /* L rotation. */
5794 p->left = r->right;
5795 if (p->left)
5796 p->left->parent = p;
5797 r->right = p;
5798
5799 p->balance = 0;
5800 r->balance = 0;
5801
5802 s = p->parent;
5803 p->parent = r;
5804 r->parent = s;
5805 if (s)
5806 {
5807 if (s->left == p)
5808 s->left = r;
5809 else
5810 s->right = r;
5811 }
5812 else
5813 constructor_pending_elts = r;
5814 }
5815 else
5816 {
5817 /* LR rotation. */
5818 struct init_node *t = r->right;
5819
5820 r->right = t->left;
5821 if (r->right)
5822 r->right->parent = r;
5823 t->left = r;
5824
5825 p->left = t->right;
5826 if (p->left)
5827 p->left->parent = p;
5828 t->right = p;
5829
5830 p->balance = t->balance < 0;
5831 r->balance = -(t->balance > 0);
5832 t->balance = 0;
5833
5834 s = p->parent;
5835 p->parent = t;
5836 r->parent = t;
5837 t->parent = s;
5838 if (s)
5839 {
5840 if (s->left == p)
5841 s->left = t;
5842 else
5843 s->right = t;
5844 }
5845 else
5846 constructor_pending_elts = t;
5847 }
5848 break;
5849 }
5850 else
5851 {
5852 /* p->balance == +1; growth of left side balances the node. */
5853 p->balance = 0;
5854 break;
5855 }
5856 }
5857 else /* r == p->right */
5858 {
5859 if (p->balance == 0)
5860 /* Growth propagation from right side. */
5861 p->balance++;
5862 else if (p->balance > 0)
5863 {
5864 if (r->balance > 0)
5865 {
5866 /* R rotation. */
5867 p->right = r->left;
5868 if (p->right)
5869 p->right->parent = p;
5870 r->left = p;
5871
5872 p->balance = 0;
5873 r->balance = 0;
5874
5875 s = p->parent;
5876 p->parent = r;
5877 r->parent = s;
5878 if (s)
5879 {
5880 if (s->left == p)
5881 s->left = r;
5882 else
5883 s->right = r;
5884 }
5885 else
5886 constructor_pending_elts = r;
5887 }
5888 else /* r->balance == -1 */
5889 {
5890 /* RL rotation */
5891 struct init_node *t = r->left;
5892
5893 r->left = t->right;
5894 if (r->left)
5895 r->left->parent = r;
5896 t->right = r;
5897
5898 p->right = t->left;
5899 if (p->right)
5900 p->right->parent = p;
5901 t->left = p;
5902
5903 r->balance = (t->balance < 0);
5904 p->balance = -(t->balance > 0);
5905 t->balance = 0;
5906
5907 s = p->parent;
5908 p->parent = t;
5909 r->parent = t;
5910 t->parent = s;
5911 if (s)
5912 {
5913 if (s->left == p)
5914 s->left = t;
5915 else
5916 s->right = t;
5917 }
5918 else
5919 constructor_pending_elts = t;
5920 }
5921 break;
5922 }
5923 else
5924 {
5925 /* p->balance == -1; growth of right side balances the node. */
5926 p->balance = 0;
5927 break;
5928 }
5929 }
5930
5931 r = p;
5932 p = p->parent;
5933 }
5934 }
5935
5936 /* Build AVL tree from a sorted chain. */
5937
5938 static void
5939 set_nonincremental_init (void)
5940 {
5941 unsigned HOST_WIDE_INT ix;
5942 tree index, value;
5943
5944 if (TREE_CODE (constructor_type) != RECORD_TYPE
5945 && TREE_CODE (constructor_type) != ARRAY_TYPE)
5946 return;
5947
5948 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
5949 add_pending_init (index, value);
5950 constructor_elements = 0;
5951 if (TREE_CODE (constructor_type) == RECORD_TYPE)
5952 {
5953 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
5954 /* Skip any nameless bit fields at the beginning. */
5955 while (constructor_unfilled_fields != 0
5956 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
5957 && DECL_NAME (constructor_unfilled_fields) == 0)
5958 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5959
5960 }
5961 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5962 {
5963 if (TYPE_DOMAIN (constructor_type))
5964 constructor_unfilled_index
5965 = convert (bitsizetype,
5966 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5967 else
5968 constructor_unfilled_index = bitsize_zero_node;
5969 }
5970 constructor_incremental = 0;
5971 }
5972
5973 /* Build AVL tree from a string constant. */
5974
5975 static void
5976 set_nonincremental_init_from_string (tree str)
5977 {
5978 tree value, purpose, type;
5979 HOST_WIDE_INT val[2];
5980 const char *p, *end;
5981 int byte, wchar_bytes, charwidth, bitpos;
5982
5983 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
5984
5985 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5986 == TYPE_PRECISION (char_type_node))
5987 wchar_bytes = 1;
5988 else
5989 {
5990 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5991 == TYPE_PRECISION (wchar_type_node));
5992 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
5993 }
5994 charwidth = TYPE_PRECISION (char_type_node);
5995 type = TREE_TYPE (constructor_type);
5996 p = TREE_STRING_POINTER (str);
5997 end = p + TREE_STRING_LENGTH (str);
5998
5999 for (purpose = bitsize_zero_node;
6000 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6001 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6002 {
6003 if (wchar_bytes == 1)
6004 {
6005 val[1] = (unsigned char) *p++;
6006 val[0] = 0;
6007 }
6008 else
6009 {
6010 val[0] = 0;
6011 val[1] = 0;
6012 for (byte = 0; byte < wchar_bytes; byte++)
6013 {
6014 if (BYTES_BIG_ENDIAN)
6015 bitpos = (wchar_bytes - byte - 1) * charwidth;
6016 else
6017 bitpos = byte * charwidth;
6018 val[bitpos < HOST_BITS_PER_WIDE_INT]
6019 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6020 << (bitpos % HOST_BITS_PER_WIDE_INT);
6021 }
6022 }
6023
6024 if (!TYPE_UNSIGNED (type))
6025 {
6026 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6027 if (bitpos < HOST_BITS_PER_WIDE_INT)
6028 {
6029 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6030 {
6031 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6032 val[0] = -1;
6033 }
6034 }
6035 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6036 {
6037 if (val[1] < 0)
6038 val[0] = -1;
6039 }
6040 else if (val[0] & (((HOST_WIDE_INT) 1)
6041 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6042 val[0] |= ((HOST_WIDE_INT) -1)
6043 << (bitpos - HOST_BITS_PER_WIDE_INT);
6044 }
6045
6046 value = build_int_cst_wide (type, val[1], val[0]);
6047 add_pending_init (purpose, value);
6048 }
6049
6050 constructor_incremental = 0;
6051 }
6052
6053 /* Return value of FIELD in pending initializer or zero if the field was
6054 not initialized yet. */
6055
6056 static tree
6057 find_init_member (tree field)
6058 {
6059 struct init_node *p;
6060
6061 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6062 {
6063 if (constructor_incremental
6064 && tree_int_cst_lt (field, constructor_unfilled_index))
6065 set_nonincremental_init ();
6066
6067 p = constructor_pending_elts;
6068 while (p)
6069 {
6070 if (tree_int_cst_lt (field, p->purpose))
6071 p = p->left;
6072 else if (tree_int_cst_lt (p->purpose, field))
6073 p = p->right;
6074 else
6075 return p->value;
6076 }
6077 }
6078 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6079 {
6080 tree bitpos = bit_position (field);
6081
6082 if (constructor_incremental
6083 && (!constructor_unfilled_fields
6084 || tree_int_cst_lt (bitpos,
6085 bit_position (constructor_unfilled_fields))))
6086 set_nonincremental_init ();
6087
6088 p = constructor_pending_elts;
6089 while (p)
6090 {
6091 if (field == p->purpose)
6092 return p->value;
6093 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6094 p = p->left;
6095 else
6096 p = p->right;
6097 }
6098 }
6099 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6100 {
6101 if (!VEC_empty (constructor_elt, constructor_elements)
6102 && (VEC_last (constructor_elt, constructor_elements)->index
6103 == field))
6104 return VEC_last (constructor_elt, constructor_elements)->value;
6105 }
6106 return 0;
6107 }
6108
6109 /* "Output" the next constructor element.
6110 At top level, really output it to assembler code now.
6111 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6112 TYPE is the data type that the containing data type wants here.
6113 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6114 If VALUE is a string constant, STRICT_STRING is true if it is
6115 unparenthesized or we should not warn here for it being parenthesized.
6116 For other types of VALUE, STRICT_STRING is not used.
6117
6118 PENDING if non-nil means output pending elements that belong
6119 right after this element. (PENDING is normally 1;
6120 it is 0 while outputting pending elements, to avoid recursion.) */
6121
6122 static void
6123 output_init_element (tree value, bool strict_string, tree type, tree field,
6124 int pending)
6125 {
6126 constructor_elt *celt;
6127
6128 if (type == error_mark_node || value == error_mark_node)
6129 {
6130 constructor_erroneous = 1;
6131 return;
6132 }
6133 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6134 && (TREE_CODE (value) == STRING_CST
6135 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6136 && !(TREE_CODE (value) == STRING_CST
6137 && TREE_CODE (type) == ARRAY_TYPE
6138 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6139 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6140 TYPE_MAIN_VARIANT (type)))
6141 value = array_to_pointer_conversion (value);
6142
6143 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6144 && require_constant_value && !flag_isoc99 && pending)
6145 {
6146 /* As an extension, allow initializing objects with static storage
6147 duration with compound literals (which are then treated just as
6148 the brace enclosed list they contain). */
6149 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6150 value = DECL_INITIAL (decl);
6151 }
6152
6153 if (value == error_mark_node)
6154 constructor_erroneous = 1;
6155 else if (!TREE_CONSTANT (value))
6156 constructor_constant = 0;
6157 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6158 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6159 || TREE_CODE (constructor_type) == UNION_TYPE)
6160 && DECL_C_BIT_FIELD (field)
6161 && TREE_CODE (value) != INTEGER_CST))
6162 constructor_simple = 0;
6163
6164 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6165 {
6166 if (require_constant_value)
6167 {
6168 error_init ("initializer element is not constant");
6169 value = error_mark_node;
6170 }
6171 else if (require_constant_elements)
6172 pedwarn ("initializer element is not computable at load time");
6173 }
6174
6175 /* If this field is empty (and not at the end of structure),
6176 don't do anything other than checking the initializer. */
6177 if (field
6178 && (TREE_TYPE (field) == error_mark_node
6179 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6180 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6181 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6182 || TREE_CHAIN (field)))))
6183 return;
6184
6185 value = digest_init (type, value, strict_string, require_constant_value);
6186 if (value == error_mark_node)
6187 {
6188 constructor_erroneous = 1;
6189 return;
6190 }
6191
6192 /* If this element doesn't come next in sequence,
6193 put it on constructor_pending_elts. */
6194 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6195 && (!constructor_incremental
6196 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6197 {
6198 if (constructor_incremental
6199 && tree_int_cst_lt (field, constructor_unfilled_index))
6200 set_nonincremental_init ();
6201
6202 add_pending_init (field, value);
6203 return;
6204 }
6205 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6206 && (!constructor_incremental
6207 || field != constructor_unfilled_fields))
6208 {
6209 /* We do this for records but not for unions. In a union,
6210 no matter which field is specified, it can be initialized
6211 right away since it starts at the beginning of the union. */
6212 if (constructor_incremental)
6213 {
6214 if (!constructor_unfilled_fields)
6215 set_nonincremental_init ();
6216 else
6217 {
6218 tree bitpos, unfillpos;
6219
6220 bitpos = bit_position (field);
6221 unfillpos = bit_position (constructor_unfilled_fields);
6222
6223 if (tree_int_cst_lt (bitpos, unfillpos))
6224 set_nonincremental_init ();
6225 }
6226 }
6227
6228 add_pending_init (field, value);
6229 return;
6230 }
6231 else if (TREE_CODE (constructor_type) == UNION_TYPE
6232 && !VEC_empty (constructor_elt, constructor_elements))
6233 {
6234 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6235 constructor_elements)->value))
6236 warning_init ("initialized field with side-effects overwritten");
6237 else if (warn_override_init)
6238 warning_init ("initialized field overwritten");
6239
6240 /* We can have just one union field set. */
6241 constructor_elements = 0;
6242 }
6243
6244 /* Otherwise, output this element either to
6245 constructor_elements or to the assembler file. */
6246
6247 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6248 celt->index = field;
6249 celt->value = value;
6250
6251 /* Advance the variable that indicates sequential elements output. */
6252 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6253 constructor_unfilled_index
6254 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6255 bitsize_one_node);
6256 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6257 {
6258 constructor_unfilled_fields
6259 = TREE_CHAIN (constructor_unfilled_fields);
6260
6261 /* Skip any nameless bit fields. */
6262 while (constructor_unfilled_fields != 0
6263 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6264 && DECL_NAME (constructor_unfilled_fields) == 0)
6265 constructor_unfilled_fields =
6266 TREE_CHAIN (constructor_unfilled_fields);
6267 }
6268 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6269 constructor_unfilled_fields = 0;
6270
6271 /* Now output any pending elements which have become next. */
6272 if (pending)
6273 output_pending_init_elements (0);
6274 }
6275
6276 /* Output any pending elements which have become next.
6277 As we output elements, constructor_unfilled_{fields,index}
6278 advances, which may cause other elements to become next;
6279 if so, they too are output.
6280
6281 If ALL is 0, we return when there are
6282 no more pending elements to output now.
6283
6284 If ALL is 1, we output space as necessary so that
6285 we can output all the pending elements. */
6286
6287 static void
6288 output_pending_init_elements (int all)
6289 {
6290 struct init_node *elt = constructor_pending_elts;
6291 tree next;
6292
6293 retry:
6294
6295 /* Look through the whole pending tree.
6296 If we find an element that should be output now,
6297 output it. Otherwise, set NEXT to the element
6298 that comes first among those still pending. */
6299
6300 next = 0;
6301 while (elt)
6302 {
6303 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6304 {
6305 if (tree_int_cst_equal (elt->purpose,
6306 constructor_unfilled_index))
6307 output_init_element (elt->value, true,
6308 TREE_TYPE (constructor_type),
6309 constructor_unfilled_index, 0);
6310 else if (tree_int_cst_lt (constructor_unfilled_index,
6311 elt->purpose))
6312 {
6313 /* Advance to the next smaller node. */
6314 if (elt->left)
6315 elt = elt->left;
6316 else
6317 {
6318 /* We have reached the smallest node bigger than the
6319 current unfilled index. Fill the space first. */
6320 next = elt->purpose;
6321 break;
6322 }
6323 }
6324 else
6325 {
6326 /* Advance to the next bigger node. */
6327 if (elt->right)
6328 elt = elt->right;
6329 else
6330 {
6331 /* We have reached the biggest node in a subtree. Find
6332 the parent of it, which is the next bigger node. */
6333 while (elt->parent && elt->parent->right == elt)
6334 elt = elt->parent;
6335 elt = elt->parent;
6336 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6337 elt->purpose))
6338 {
6339 next = elt->purpose;
6340 break;
6341 }
6342 }
6343 }
6344 }
6345 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6346 || TREE_CODE (constructor_type) == UNION_TYPE)
6347 {
6348 tree ctor_unfilled_bitpos, elt_bitpos;
6349
6350 /* If the current record is complete we are done. */
6351 if (constructor_unfilled_fields == 0)
6352 break;
6353
6354 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6355 elt_bitpos = bit_position (elt->purpose);
6356 /* We can't compare fields here because there might be empty
6357 fields in between. */
6358 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6359 {
6360 constructor_unfilled_fields = elt->purpose;
6361 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6362 elt->purpose, 0);
6363 }
6364 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6365 {
6366 /* Advance to the next smaller node. */
6367 if (elt->left)
6368 elt = elt->left;
6369 else
6370 {
6371 /* We have reached the smallest node bigger than the
6372 current unfilled field. Fill the space first. */
6373 next = elt->purpose;
6374 break;
6375 }
6376 }
6377 else
6378 {
6379 /* Advance to the next bigger node. */
6380 if (elt->right)
6381 elt = elt->right;
6382 else
6383 {
6384 /* We have reached the biggest node in a subtree. Find
6385 the parent of it, which is the next bigger node. */
6386 while (elt->parent && elt->parent->right == elt)
6387 elt = elt->parent;
6388 elt = elt->parent;
6389 if (elt
6390 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6391 bit_position (elt->purpose))))
6392 {
6393 next = elt->purpose;
6394 break;
6395 }
6396 }
6397 }
6398 }
6399 }
6400
6401 /* Ordinarily return, but not if we want to output all
6402 and there are elements left. */
6403 if (!(all && next != 0))
6404 return;
6405
6406 /* If it's not incremental, just skip over the gap, so that after
6407 jumping to retry we will output the next successive element. */
6408 if (TREE_CODE (constructor_type) == RECORD_TYPE
6409 || TREE_CODE (constructor_type) == UNION_TYPE)
6410 constructor_unfilled_fields = next;
6411 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6412 constructor_unfilled_index = next;
6413
6414 /* ELT now points to the node in the pending tree with the next
6415 initializer to output. */
6416 goto retry;
6417 }
6418 \f
6419 /* Add one non-braced element to the current constructor level.
6420 This adjusts the current position within the constructor's type.
6421 This may also start or terminate implicit levels
6422 to handle a partly-braced initializer.
6423
6424 Once this has found the correct level for the new element,
6425 it calls output_init_element. */
6426
6427 void
6428 process_init_element (struct c_expr value)
6429 {
6430 tree orig_value = value.value;
6431 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6432 bool strict_string = value.original_code == STRING_CST;
6433
6434 designator_depth = 0;
6435 designator_erroneous = 0;
6436
6437 /* Handle superfluous braces around string cst as in
6438 char x[] = {"foo"}; */
6439 if (string_flag
6440 && constructor_type
6441 && TREE_CODE (constructor_type) == ARRAY_TYPE
6442 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6443 && integer_zerop (constructor_unfilled_index))
6444 {
6445 if (constructor_stack->replacement_value.value)
6446 error_init ("excess elements in char array initializer");
6447 constructor_stack->replacement_value = value;
6448 return;
6449 }
6450
6451 if (constructor_stack->replacement_value.value != 0)
6452 {
6453 error_init ("excess elements in struct initializer");
6454 return;
6455 }
6456
6457 /* Ignore elements of a brace group if it is entirely superfluous
6458 and has already been diagnosed. */
6459 if (constructor_type == 0)
6460 return;
6461
6462 /* If we've exhausted any levels that didn't have braces,
6463 pop them now. */
6464 while (constructor_stack->implicit)
6465 {
6466 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6467 || TREE_CODE (constructor_type) == UNION_TYPE)
6468 && constructor_fields == 0)
6469 process_init_element (pop_init_level (1));
6470 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6471 && (constructor_max_index == 0
6472 || tree_int_cst_lt (constructor_max_index,
6473 constructor_index)))
6474 process_init_element (pop_init_level (1));
6475 else
6476 break;
6477 }
6478
6479 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6480 if (constructor_range_stack)
6481 {
6482 /* If value is a compound literal and we'll be just using its
6483 content, don't put it into a SAVE_EXPR. */
6484 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6485 || !require_constant_value
6486 || flag_isoc99)
6487 value.value = save_expr (value.value);
6488 }
6489
6490 while (1)
6491 {
6492 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6493 {
6494 tree fieldtype;
6495 enum tree_code fieldcode;
6496
6497 if (constructor_fields == 0)
6498 {
6499 pedwarn_init ("excess elements in struct initializer");
6500 break;
6501 }
6502
6503 fieldtype = TREE_TYPE (constructor_fields);
6504 if (fieldtype != error_mark_node)
6505 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6506 fieldcode = TREE_CODE (fieldtype);
6507
6508 /* Error for non-static initialization of a flexible array member. */
6509 if (fieldcode == ARRAY_TYPE
6510 && !require_constant_value
6511 && TYPE_SIZE (fieldtype) == NULL_TREE
6512 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6513 {
6514 error_init ("non-static initialization of a flexible array member");
6515 break;
6516 }
6517
6518 /* Accept a string constant to initialize a subarray. */
6519 if (value.value != 0
6520 && fieldcode == ARRAY_TYPE
6521 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6522 && string_flag)
6523 value.value = orig_value;
6524 /* Otherwise, if we have come to a subaggregate,
6525 and we don't have an element of its type, push into it. */
6526 else if (value.value != 0
6527 && value.value != error_mark_node
6528 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6529 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6530 || fieldcode == UNION_TYPE))
6531 {
6532 push_init_level (1);
6533 continue;
6534 }
6535
6536 if (value.value)
6537 {
6538 push_member_name (constructor_fields);
6539 output_init_element (value.value, strict_string,
6540 fieldtype, constructor_fields, 1);
6541 RESTORE_SPELLING_DEPTH (constructor_depth);
6542 }
6543 else
6544 /* Do the bookkeeping for an element that was
6545 directly output as a constructor. */
6546 {
6547 /* For a record, keep track of end position of last field. */
6548 if (DECL_SIZE (constructor_fields))
6549 constructor_bit_index
6550 = size_binop (PLUS_EXPR,
6551 bit_position (constructor_fields),
6552 DECL_SIZE (constructor_fields));
6553
6554 /* If the current field was the first one not yet written out,
6555 it isn't now, so update. */
6556 if (constructor_unfilled_fields == constructor_fields)
6557 {
6558 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6559 /* Skip any nameless bit fields. */
6560 while (constructor_unfilled_fields != 0
6561 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6562 && DECL_NAME (constructor_unfilled_fields) == 0)
6563 constructor_unfilled_fields =
6564 TREE_CHAIN (constructor_unfilled_fields);
6565 }
6566 }
6567
6568 constructor_fields = TREE_CHAIN (constructor_fields);
6569 /* Skip any nameless bit fields at the beginning. */
6570 while (constructor_fields != 0
6571 && DECL_C_BIT_FIELD (constructor_fields)
6572 && DECL_NAME (constructor_fields) == 0)
6573 constructor_fields = TREE_CHAIN (constructor_fields);
6574 }
6575 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6576 {
6577 tree fieldtype;
6578 enum tree_code fieldcode;
6579
6580 if (constructor_fields == 0)
6581 {
6582 pedwarn_init ("excess elements in union initializer");
6583 break;
6584 }
6585
6586 fieldtype = TREE_TYPE (constructor_fields);
6587 if (fieldtype != error_mark_node)
6588 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6589 fieldcode = TREE_CODE (fieldtype);
6590
6591 /* Warn that traditional C rejects initialization of unions.
6592 We skip the warning if the value is zero. This is done
6593 under the assumption that the zero initializer in user
6594 code appears conditioned on e.g. __STDC__ to avoid
6595 "missing initializer" warnings and relies on default
6596 initialization to zero in the traditional C case.
6597 We also skip the warning if the initializer is designated,
6598 again on the assumption that this must be conditional on
6599 __STDC__ anyway (and we've already complained about the
6600 member-designator already). */
6601 if (!in_system_header && !constructor_designated
6602 && !(value.value && (integer_zerop (value.value)
6603 || real_zerop (value.value))))
6604 warning (OPT_Wtraditional, "traditional C rejects initialization "
6605 "of unions");
6606
6607 /* Accept a string constant to initialize a subarray. */
6608 if (value.value != 0
6609 && fieldcode == ARRAY_TYPE
6610 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6611 && string_flag)
6612 value.value = orig_value;
6613 /* Otherwise, if we have come to a subaggregate,
6614 and we don't have an element of its type, push into it. */
6615 else if (value.value != 0
6616 && value.value != error_mark_node
6617 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6618 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6619 || fieldcode == UNION_TYPE))
6620 {
6621 push_init_level (1);
6622 continue;
6623 }
6624
6625 if (value.value)
6626 {
6627 push_member_name (constructor_fields);
6628 output_init_element (value.value, strict_string,
6629 fieldtype, constructor_fields, 1);
6630 RESTORE_SPELLING_DEPTH (constructor_depth);
6631 }
6632 else
6633 /* Do the bookkeeping for an element that was
6634 directly output as a constructor. */
6635 {
6636 constructor_bit_index = DECL_SIZE (constructor_fields);
6637 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6638 }
6639
6640 constructor_fields = 0;
6641 }
6642 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6643 {
6644 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6645 enum tree_code eltcode = TREE_CODE (elttype);
6646
6647 /* Accept a string constant to initialize a subarray. */
6648 if (value.value != 0
6649 && eltcode == ARRAY_TYPE
6650 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6651 && string_flag)
6652 value.value = orig_value;
6653 /* Otherwise, if we have come to a subaggregate,
6654 and we don't have an element of its type, push into it. */
6655 else if (value.value != 0
6656 && value.value != error_mark_node
6657 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6658 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6659 || eltcode == UNION_TYPE))
6660 {
6661 push_init_level (1);
6662 continue;
6663 }
6664
6665 if (constructor_max_index != 0
6666 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6667 || integer_all_onesp (constructor_max_index)))
6668 {
6669 pedwarn_init ("excess elements in array initializer");
6670 break;
6671 }
6672
6673 /* Now output the actual element. */
6674 if (value.value)
6675 {
6676 push_array_bounds (tree_low_cst (constructor_index, 1));
6677 output_init_element (value.value, strict_string,
6678 elttype, constructor_index, 1);
6679 RESTORE_SPELLING_DEPTH (constructor_depth);
6680 }
6681
6682 constructor_index
6683 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6684
6685 if (!value.value)
6686 /* If we are doing the bookkeeping for an element that was
6687 directly output as a constructor, we must update
6688 constructor_unfilled_index. */
6689 constructor_unfilled_index = constructor_index;
6690 }
6691 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6692 {
6693 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6694
6695 /* Do a basic check of initializer size. Note that vectors
6696 always have a fixed size derived from their type. */
6697 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6698 {
6699 pedwarn_init ("excess elements in vector initializer");
6700 break;
6701 }
6702
6703 /* Now output the actual element. */
6704 if (value.value)
6705 output_init_element (value.value, strict_string,
6706 elttype, constructor_index, 1);
6707
6708 constructor_index
6709 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6710
6711 if (!value.value)
6712 /* If we are doing the bookkeeping for an element that was
6713 directly output as a constructor, we must update
6714 constructor_unfilled_index. */
6715 constructor_unfilled_index = constructor_index;
6716 }
6717
6718 /* Handle the sole element allowed in a braced initializer
6719 for a scalar variable. */
6720 else if (constructor_type != error_mark_node
6721 && constructor_fields == 0)
6722 {
6723 pedwarn_init ("excess elements in scalar initializer");
6724 break;
6725 }
6726 else
6727 {
6728 if (value.value)
6729 output_init_element (value.value, strict_string,
6730 constructor_type, NULL_TREE, 1);
6731 constructor_fields = 0;
6732 }
6733
6734 /* Handle range initializers either at this level or anywhere higher
6735 in the designator stack. */
6736 if (constructor_range_stack)
6737 {
6738 struct constructor_range_stack *p, *range_stack;
6739 int finish = 0;
6740
6741 range_stack = constructor_range_stack;
6742 constructor_range_stack = 0;
6743 while (constructor_stack != range_stack->stack)
6744 {
6745 gcc_assert (constructor_stack->implicit);
6746 process_init_element (pop_init_level (1));
6747 }
6748 for (p = range_stack;
6749 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6750 p = p->prev)
6751 {
6752 gcc_assert (constructor_stack->implicit);
6753 process_init_element (pop_init_level (1));
6754 }
6755
6756 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6757 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6758 finish = 1;
6759
6760 while (1)
6761 {
6762 constructor_index = p->index;
6763 constructor_fields = p->fields;
6764 if (finish && p->range_end && p->index == p->range_start)
6765 {
6766 finish = 0;
6767 p->prev = 0;
6768 }
6769 p = p->next;
6770 if (!p)
6771 break;
6772 push_init_level (2);
6773 p->stack = constructor_stack;
6774 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6775 p->index = p->range_start;
6776 }
6777
6778 if (!finish)
6779 constructor_range_stack = range_stack;
6780 continue;
6781 }
6782
6783 break;
6784 }
6785
6786 constructor_range_stack = 0;
6787 }
6788 \f
6789 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6790 (guaranteed to be 'volatile' or null) and ARGS (represented using
6791 an ASM_EXPR node). */
6792 tree
6793 build_asm_stmt (tree cv_qualifier, tree args)
6794 {
6795 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6796 ASM_VOLATILE_P (args) = 1;
6797 return add_stmt (args);
6798 }
6799
6800 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6801 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6802 SIMPLE indicates whether there was anything at all after the
6803 string in the asm expression -- asm("blah") and asm("blah" : )
6804 are subtly different. We use a ASM_EXPR node to represent this. */
6805 tree
6806 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6807 bool simple)
6808 {
6809 tree tail;
6810 tree args;
6811 int i;
6812 const char *constraint;
6813 const char **oconstraints;
6814 bool allows_mem, allows_reg, is_inout;
6815 int ninputs, noutputs;
6816
6817 ninputs = list_length (inputs);
6818 noutputs = list_length (outputs);
6819 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6820
6821 string = resolve_asm_operand_names (string, outputs, inputs);
6822
6823 /* Remove output conversions that change the type but not the mode. */
6824 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6825 {
6826 tree output = TREE_VALUE (tail);
6827
6828 /* ??? Really, this should not be here. Users should be using a
6829 proper lvalue, dammit. But there's a long history of using casts
6830 in the output operands. In cases like longlong.h, this becomes a
6831 primitive form of typechecking -- if the cast can be removed, then
6832 the output operand had a type of the proper width; otherwise we'll
6833 get an error. Gross, but ... */
6834 STRIP_NOPS (output);
6835
6836 if (!lvalue_or_else (output, lv_asm))
6837 output = error_mark_node;
6838
6839 if (output != error_mark_node
6840 && (TREE_READONLY (output)
6841 || TYPE_READONLY (TREE_TYPE (output))
6842 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6843 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6844 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6845 readonly_error (output, lv_asm);
6846
6847 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6848 oconstraints[i] = constraint;
6849
6850 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6851 &allows_mem, &allows_reg, &is_inout))
6852 {
6853 /* If the operand is going to end up in memory,
6854 mark it addressable. */
6855 if (!allows_reg && !c_mark_addressable (output))
6856 output = error_mark_node;
6857 }
6858 else
6859 output = error_mark_node;
6860
6861 TREE_VALUE (tail) = output;
6862 }
6863
6864 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
6865 {
6866 tree input;
6867
6868 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6869 input = TREE_VALUE (tail);
6870
6871 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
6872 oconstraints, &allows_mem, &allows_reg))
6873 {
6874 /* If the operand is going to end up in memory,
6875 mark it addressable. */
6876 if (!allows_reg && allows_mem)
6877 {
6878 /* Strip the nops as we allow this case. FIXME, this really
6879 should be rejected or made deprecated. */
6880 STRIP_NOPS (input);
6881 if (!c_mark_addressable (input))
6882 input = error_mark_node;
6883 }
6884 }
6885 else
6886 input = error_mark_node;
6887
6888 TREE_VALUE (tail) = input;
6889 }
6890
6891 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
6892
6893 /* asm statements without outputs, including simple ones, are treated
6894 as volatile. */
6895 ASM_INPUT_P (args) = simple;
6896 ASM_VOLATILE_P (args) = (noutputs == 0);
6897
6898 return args;
6899 }
6900 \f
6901 /* Generate a goto statement to LABEL. */
6902
6903 tree
6904 c_finish_goto_label (tree label)
6905 {
6906 tree decl = lookup_label (label);
6907 if (!decl)
6908 return NULL_TREE;
6909
6910 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
6911 {
6912 error ("jump into statement expression");
6913 return NULL_TREE;
6914 }
6915
6916 if (C_DECL_UNJUMPABLE_VM (decl))
6917 {
6918 error ("jump into scope of identifier with variably modified type");
6919 return NULL_TREE;
6920 }
6921
6922 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
6923 {
6924 /* No jump from outside this statement expression context, so
6925 record that there is a jump from within this context. */
6926 struct c_label_list *nlist;
6927 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6928 nlist->next = label_context_stack_se->labels_used;
6929 nlist->label = decl;
6930 label_context_stack_se->labels_used = nlist;
6931 }
6932
6933 if (!C_DECL_UNDEFINABLE_VM (decl))
6934 {
6935 /* No jump from outside this context context of identifiers with
6936 variably modified type, so record that there is a jump from
6937 within this context. */
6938 struct c_label_list *nlist;
6939 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6940 nlist->next = label_context_stack_vm->labels_used;
6941 nlist->label = decl;
6942 label_context_stack_vm->labels_used = nlist;
6943 }
6944
6945 TREE_USED (decl) = 1;
6946 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
6947 }
6948
6949 /* Generate a computed goto statement to EXPR. */
6950
6951 tree
6952 c_finish_goto_ptr (tree expr)
6953 {
6954 if (pedantic)
6955 pedwarn ("ISO C forbids %<goto *expr;%>");
6956 expr = convert (ptr_type_node, expr);
6957 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
6958 }
6959
6960 /* Generate a C `return' statement. RETVAL is the expression for what
6961 to return, or a null pointer for `return;' with no value. */
6962
6963 tree
6964 c_finish_return (tree retval)
6965 {
6966 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
6967 bool no_warning = false;
6968
6969 if (TREE_THIS_VOLATILE (current_function_decl))
6970 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6971
6972 if (!retval)
6973 {
6974 current_function_returns_null = 1;
6975 if ((warn_return_type || flag_isoc99)
6976 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
6977 {
6978 pedwarn_c99 ("%<return%> with no value, in "
6979 "function returning non-void");
6980 no_warning = true;
6981 }
6982 }
6983 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
6984 {
6985 current_function_returns_null = 1;
6986 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
6987 pedwarn ("%<return%> with a value, in function returning void");
6988 }
6989 else
6990 {
6991 tree t = convert_for_assignment (valtype, retval, ic_return,
6992 NULL_TREE, NULL_TREE, 0);
6993 tree res = DECL_RESULT (current_function_decl);
6994 tree inner;
6995
6996 current_function_returns_value = 1;
6997 if (t == error_mark_node)
6998 return NULL_TREE;
6999
7000 inner = t = convert (TREE_TYPE (res), t);
7001
7002 /* Strip any conversions, additions, and subtractions, and see if
7003 we are returning the address of a local variable. Warn if so. */
7004 while (1)
7005 {
7006 switch (TREE_CODE (inner))
7007 {
7008 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
7009 case PLUS_EXPR:
7010 inner = TREE_OPERAND (inner, 0);
7011 continue;
7012
7013 case MINUS_EXPR:
7014 /* If the second operand of the MINUS_EXPR has a pointer
7015 type (or is converted from it), this may be valid, so
7016 don't give a warning. */
7017 {
7018 tree op1 = TREE_OPERAND (inner, 1);
7019
7020 while (!POINTER_TYPE_P (TREE_TYPE (op1))
7021 && (TREE_CODE (op1) == NOP_EXPR
7022 || TREE_CODE (op1) == NON_LVALUE_EXPR
7023 || TREE_CODE (op1) == CONVERT_EXPR))
7024 op1 = TREE_OPERAND (op1, 0);
7025
7026 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7027 break;
7028
7029 inner = TREE_OPERAND (inner, 0);
7030 continue;
7031 }
7032
7033 case ADDR_EXPR:
7034 inner = TREE_OPERAND (inner, 0);
7035
7036 while (REFERENCE_CLASS_P (inner)
7037 && TREE_CODE (inner) != INDIRECT_REF)
7038 inner = TREE_OPERAND (inner, 0);
7039
7040 if (DECL_P (inner)
7041 && !DECL_EXTERNAL (inner)
7042 && !TREE_STATIC (inner)
7043 && DECL_CONTEXT (inner) == current_function_decl)
7044 warning (0, "function returns address of local variable");
7045 break;
7046
7047 default:
7048 break;
7049 }
7050
7051 break;
7052 }
7053
7054 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7055 }
7056
7057 ret_stmt = build_stmt (RETURN_EXPR, retval);
7058 TREE_NO_WARNING (ret_stmt) |= no_warning;
7059 return add_stmt (ret_stmt);
7060 }
7061 \f
7062 struct c_switch {
7063 /* The SWITCH_EXPR being built. */
7064 tree switch_expr;
7065
7066 /* The original type of the testing expression, i.e. before the
7067 default conversion is applied. */
7068 tree orig_type;
7069
7070 /* A splay-tree mapping the low element of a case range to the high
7071 element, or NULL_TREE if there is no high element. Used to
7072 determine whether or not a new case label duplicates an old case
7073 label. We need a tree, rather than simply a hash table, because
7074 of the GNU case range extension. */
7075 splay_tree cases;
7076
7077 /* Number of nested statement expressions within this switch
7078 statement; if nonzero, case and default labels may not
7079 appear. */
7080 unsigned int blocked_stmt_expr;
7081
7082 /* Scope of outermost declarations of identifiers with variably
7083 modified type within this switch statement; if nonzero, case and
7084 default labels may not appear. */
7085 unsigned int blocked_vm;
7086
7087 /* The next node on the stack. */
7088 struct c_switch *next;
7089 };
7090
7091 /* A stack of the currently active switch statements. The innermost
7092 switch statement is on the top of the stack. There is no need to
7093 mark the stack for garbage collection because it is only active
7094 during the processing of the body of a function, and we never
7095 collect at that point. */
7096
7097 struct c_switch *c_switch_stack;
7098
7099 /* Start a C switch statement, testing expression EXP. Return the new
7100 SWITCH_EXPR. */
7101
7102 tree
7103 c_start_case (tree exp)
7104 {
7105 tree orig_type = error_mark_node;
7106 struct c_switch *cs;
7107
7108 if (exp != error_mark_node)
7109 {
7110 orig_type = TREE_TYPE (exp);
7111
7112 if (!INTEGRAL_TYPE_P (orig_type))
7113 {
7114 if (orig_type != error_mark_node)
7115 {
7116 error ("switch quantity not an integer");
7117 orig_type = error_mark_node;
7118 }
7119 exp = integer_zero_node;
7120 }
7121 else
7122 {
7123 tree type = TYPE_MAIN_VARIANT (orig_type);
7124
7125 if (!in_system_header
7126 && (type == long_integer_type_node
7127 || type == long_unsigned_type_node))
7128 warning (OPT_Wtraditional, "%<long%> switch expression not "
7129 "converted to %<int%> in ISO C");
7130
7131 exp = default_conversion (exp);
7132 }
7133 }
7134
7135 /* Add this new SWITCH_EXPR to the stack. */
7136 cs = XNEW (struct c_switch);
7137 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7138 cs->orig_type = orig_type;
7139 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7140 cs->blocked_stmt_expr = 0;
7141 cs->blocked_vm = 0;
7142 cs->next = c_switch_stack;
7143 c_switch_stack = cs;
7144
7145 return add_stmt (cs->switch_expr);
7146 }
7147
7148 /* Process a case label. */
7149
7150 tree
7151 do_case (tree low_value, tree high_value)
7152 {
7153 tree label = NULL_TREE;
7154
7155 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7156 && !c_switch_stack->blocked_vm)
7157 {
7158 label = c_add_case_label (c_switch_stack->cases,
7159 SWITCH_COND (c_switch_stack->switch_expr),
7160 c_switch_stack->orig_type,
7161 low_value, high_value);
7162 if (label == error_mark_node)
7163 label = NULL_TREE;
7164 }
7165 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7166 {
7167 if (low_value)
7168 error ("case label in statement expression not containing "
7169 "enclosing switch statement");
7170 else
7171 error ("%<default%> label in statement expression not containing "
7172 "enclosing switch statement");
7173 }
7174 else if (c_switch_stack && c_switch_stack->blocked_vm)
7175 {
7176 if (low_value)
7177 error ("case label in scope of identifier with variably modified "
7178 "type not containing enclosing switch statement");
7179 else
7180 error ("%<default%> label in scope of identifier with variably "
7181 "modified type not containing enclosing switch statement");
7182 }
7183 else if (low_value)
7184 error ("case label not within a switch statement");
7185 else
7186 error ("%<default%> label not within a switch statement");
7187
7188 return label;
7189 }
7190
7191 /* Finish the switch statement. */
7192
7193 void
7194 c_finish_case (tree body)
7195 {
7196 struct c_switch *cs = c_switch_stack;
7197 location_t switch_location;
7198
7199 SWITCH_BODY (cs->switch_expr) = body;
7200
7201 /* We must not be within a statement expression nested in the switch
7202 at this point; we might, however, be within the scope of an
7203 identifier with variably modified type nested in the switch. */
7204 gcc_assert (!cs->blocked_stmt_expr);
7205
7206 /* Emit warnings as needed. */
7207 if (EXPR_HAS_LOCATION (cs->switch_expr))
7208 switch_location = EXPR_LOCATION (cs->switch_expr);
7209 else
7210 switch_location = input_location;
7211 c_do_switch_warnings (cs->cases, switch_location,
7212 TREE_TYPE (cs->switch_expr),
7213 SWITCH_COND (cs->switch_expr));
7214
7215 /* Pop the stack. */
7216 c_switch_stack = cs->next;
7217 splay_tree_delete (cs->cases);
7218 XDELETE (cs);
7219 }
7220 \f
7221 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7222 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7223 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7224 statement, and was not surrounded with parenthesis. */
7225
7226 void
7227 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7228 tree else_block, bool nested_if)
7229 {
7230 tree stmt;
7231
7232 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7233 if (warn_parentheses && nested_if && else_block == NULL)
7234 {
7235 tree inner_if = then_block;
7236
7237 /* We know from the grammar productions that there is an IF nested
7238 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7239 it might not be exactly THEN_BLOCK, but should be the last
7240 non-container statement within. */
7241 while (1)
7242 switch (TREE_CODE (inner_if))
7243 {
7244 case COND_EXPR:
7245 goto found;
7246 case BIND_EXPR:
7247 inner_if = BIND_EXPR_BODY (inner_if);
7248 break;
7249 case STATEMENT_LIST:
7250 inner_if = expr_last (then_block);
7251 break;
7252 case TRY_FINALLY_EXPR:
7253 case TRY_CATCH_EXPR:
7254 inner_if = TREE_OPERAND (inner_if, 0);
7255 break;
7256 default:
7257 gcc_unreachable ();
7258 }
7259 found:
7260
7261 if (COND_EXPR_ELSE (inner_if))
7262 warning (OPT_Wparentheses,
7263 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7264 &if_locus);
7265 }
7266
7267 empty_body_warning (then_block, else_block);
7268
7269 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7270 SET_EXPR_LOCATION (stmt, if_locus);
7271 add_stmt (stmt);
7272 }
7273
7274 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7275 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7276 is false for DO loops. INCR is the FOR increment expression. BODY is
7277 the statement controlled by the loop. BLAB is the break label. CLAB is
7278 the continue label. Everything is allowed to be NULL. */
7279
7280 void
7281 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7282 tree blab, tree clab, bool cond_is_first)
7283 {
7284 tree entry = NULL, exit = NULL, t;
7285
7286 /* If the condition is zero don't generate a loop construct. */
7287 if (cond && integer_zerop (cond))
7288 {
7289 if (cond_is_first)
7290 {
7291 t = build_and_jump (&blab);
7292 SET_EXPR_LOCATION (t, start_locus);
7293 add_stmt (t);
7294 }
7295 }
7296 else
7297 {
7298 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7299
7300 /* If we have an exit condition, then we build an IF with gotos either
7301 out of the loop, or to the top of it. If there's no exit condition,
7302 then we just build a jump back to the top. */
7303 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7304
7305 if (cond && !integer_nonzerop (cond))
7306 {
7307 /* Canonicalize the loop condition to the end. This means
7308 generating a branch to the loop condition. Reuse the
7309 continue label, if possible. */
7310 if (cond_is_first)
7311 {
7312 if (incr || !clab)
7313 {
7314 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7315 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7316 }
7317 else
7318 t = build1 (GOTO_EXPR, void_type_node, clab);
7319 SET_EXPR_LOCATION (t, start_locus);
7320 add_stmt (t);
7321 }
7322
7323 t = build_and_jump (&blab);
7324 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7325 if (cond_is_first)
7326 SET_EXPR_LOCATION (exit, start_locus);
7327 else
7328 SET_EXPR_LOCATION (exit, input_location);
7329 }
7330
7331 add_stmt (top);
7332 }
7333
7334 if (body)
7335 add_stmt (body);
7336 if (clab)
7337 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7338 if (incr)
7339 add_stmt (incr);
7340 if (entry)
7341 add_stmt (entry);
7342 if (exit)
7343 add_stmt (exit);
7344 if (blab)
7345 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7346 }
7347
7348 tree
7349 c_finish_bc_stmt (tree *label_p, bool is_break)
7350 {
7351 bool skip;
7352 tree label = *label_p;
7353
7354 /* In switch statements break is sometimes stylistically used after
7355 a return statement. This can lead to spurious warnings about
7356 control reaching the end of a non-void function when it is
7357 inlined. Note that we are calling block_may_fallthru with
7358 language specific tree nodes; this works because
7359 block_may_fallthru returns true when given something it does not
7360 understand. */
7361 skip = !block_may_fallthru (cur_stmt_list);
7362
7363 if (!label)
7364 {
7365 if (!skip)
7366 *label_p = label = create_artificial_label ();
7367 }
7368 else if (TREE_CODE (label) == LABEL_DECL)
7369 ;
7370 else switch (TREE_INT_CST_LOW (label))
7371 {
7372 case 0:
7373 if (is_break)
7374 error ("break statement not within loop or switch");
7375 else
7376 error ("continue statement not within a loop");
7377 return NULL_TREE;
7378
7379 case 1:
7380 gcc_assert (is_break);
7381 error ("break statement used with OpenMP for loop");
7382 return NULL_TREE;
7383
7384 default:
7385 gcc_unreachable ();
7386 }
7387
7388 if (skip)
7389 return NULL_TREE;
7390
7391 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7392 }
7393
7394 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7395
7396 static void
7397 emit_side_effect_warnings (tree expr)
7398 {
7399 if (expr == error_mark_node)
7400 ;
7401 else if (!TREE_SIDE_EFFECTS (expr))
7402 {
7403 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7404 warning (0, "%Hstatement with no effect",
7405 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7406 }
7407 else if (warn_unused_value)
7408 warn_if_unused_value (expr, input_location);
7409 }
7410
7411 /* Process an expression as if it were a complete statement. Emit
7412 diagnostics, but do not call ADD_STMT. */
7413
7414 tree
7415 c_process_expr_stmt (tree expr)
7416 {
7417 if (!expr)
7418 return NULL_TREE;
7419
7420 if (warn_sequence_point)
7421 verify_sequence_points (expr);
7422
7423 if (TREE_TYPE (expr) != error_mark_node
7424 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7425 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7426 error ("expression statement has incomplete type");
7427
7428 /* If we're not processing a statement expression, warn about unused values.
7429 Warnings for statement expressions will be emitted later, once we figure
7430 out which is the result. */
7431 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7432 && (extra_warnings || warn_unused_value))
7433 emit_side_effect_warnings (expr);
7434
7435 /* If the expression is not of a type to which we cannot assign a line
7436 number, wrap the thing in a no-op NOP_EXPR. */
7437 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7438 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7439
7440 if (EXPR_P (expr))
7441 SET_EXPR_LOCATION (expr, input_location);
7442
7443 return expr;
7444 }
7445
7446 /* Emit an expression as a statement. */
7447
7448 tree
7449 c_finish_expr_stmt (tree expr)
7450 {
7451 if (expr)
7452 return add_stmt (c_process_expr_stmt (expr));
7453 else
7454 return NULL;
7455 }
7456
7457 /* Do the opposite and emit a statement as an expression. To begin,
7458 create a new binding level and return it. */
7459
7460 tree
7461 c_begin_stmt_expr (void)
7462 {
7463 tree ret;
7464 struct c_label_context_se *nstack;
7465 struct c_label_list *glist;
7466
7467 /* We must force a BLOCK for this level so that, if it is not expanded
7468 later, there is a way to turn off the entire subtree of blocks that
7469 are contained in it. */
7470 keep_next_level ();
7471 ret = c_begin_compound_stmt (true);
7472 if (c_switch_stack)
7473 {
7474 c_switch_stack->blocked_stmt_expr++;
7475 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7476 }
7477 for (glist = label_context_stack_se->labels_used;
7478 glist != NULL;
7479 glist = glist->next)
7480 {
7481 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7482 }
7483 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7484 nstack->labels_def = NULL;
7485 nstack->labels_used = NULL;
7486 nstack->next = label_context_stack_se;
7487 label_context_stack_se = nstack;
7488
7489 /* Mark the current statement list as belonging to a statement list. */
7490 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7491
7492 return ret;
7493 }
7494
7495 tree
7496 c_finish_stmt_expr (tree body)
7497 {
7498 tree last, type, tmp, val;
7499 tree *last_p;
7500 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7501
7502 body = c_end_compound_stmt (body, true);
7503 if (c_switch_stack)
7504 {
7505 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7506 c_switch_stack->blocked_stmt_expr--;
7507 }
7508 /* It is no longer possible to jump to labels defined within this
7509 statement expression. */
7510 for (dlist = label_context_stack_se->labels_def;
7511 dlist != NULL;
7512 dlist = dlist->next)
7513 {
7514 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7515 }
7516 /* It is again possible to define labels with a goto just outside
7517 this statement expression. */
7518 for (glist = label_context_stack_se->next->labels_used;
7519 glist != NULL;
7520 glist = glist->next)
7521 {
7522 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7523 glist_prev = glist;
7524 }
7525 if (glist_prev != NULL)
7526 glist_prev->next = label_context_stack_se->labels_used;
7527 else
7528 label_context_stack_se->next->labels_used
7529 = label_context_stack_se->labels_used;
7530 label_context_stack_se = label_context_stack_se->next;
7531
7532 /* Locate the last statement in BODY. See c_end_compound_stmt
7533 about always returning a BIND_EXPR. */
7534 last_p = &BIND_EXPR_BODY (body);
7535 last = BIND_EXPR_BODY (body);
7536
7537 continue_searching:
7538 if (TREE_CODE (last) == STATEMENT_LIST)
7539 {
7540 tree_stmt_iterator i;
7541
7542 /* This can happen with degenerate cases like ({ }). No value. */
7543 if (!TREE_SIDE_EFFECTS (last))
7544 return body;
7545
7546 /* If we're supposed to generate side effects warnings, process
7547 all of the statements except the last. */
7548 if (extra_warnings || warn_unused_value)
7549 {
7550 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7551 emit_side_effect_warnings (tsi_stmt (i));
7552 }
7553 else
7554 i = tsi_last (last);
7555 last_p = tsi_stmt_ptr (i);
7556 last = *last_p;
7557 }
7558
7559 /* If the end of the list is exception related, then the list was split
7560 by a call to push_cleanup. Continue searching. */
7561 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7562 || TREE_CODE (last) == TRY_CATCH_EXPR)
7563 {
7564 last_p = &TREE_OPERAND (last, 0);
7565 last = *last_p;
7566 goto continue_searching;
7567 }
7568
7569 /* In the case that the BIND_EXPR is not necessary, return the
7570 expression out from inside it. */
7571 if (last == error_mark_node
7572 || (last == BIND_EXPR_BODY (body)
7573 && BIND_EXPR_VARS (body) == NULL))
7574 {
7575 /* Do not warn if the return value of a statement expression is
7576 unused. */
7577 if (EXPR_P (last))
7578 TREE_NO_WARNING (last) = 1;
7579 return last;
7580 }
7581
7582 /* Extract the type of said expression. */
7583 type = TREE_TYPE (last);
7584
7585 /* If we're not returning a value at all, then the BIND_EXPR that
7586 we already have is a fine expression to return. */
7587 if (!type || VOID_TYPE_P (type))
7588 return body;
7589
7590 /* Now that we've located the expression containing the value, it seems
7591 silly to make voidify_wrapper_expr repeat the process. Create a
7592 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7593 tmp = create_tmp_var_raw (type, NULL);
7594
7595 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7596 tree_expr_nonnegative_p giving up immediately. */
7597 val = last;
7598 if (TREE_CODE (val) == NOP_EXPR
7599 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7600 val = TREE_OPERAND (val, 0);
7601
7602 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7603 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7604
7605 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7606 }
7607
7608 /* Begin the scope of an identifier of variably modified type, scope
7609 number SCOPE. Jumping from outside this scope to inside it is not
7610 permitted. */
7611
7612 void
7613 c_begin_vm_scope (unsigned int scope)
7614 {
7615 struct c_label_context_vm *nstack;
7616 struct c_label_list *glist;
7617
7618 gcc_assert (scope > 0);
7619
7620 /* At file_scope, we don't have to do any processing. */
7621 if (label_context_stack_vm == NULL)
7622 return;
7623
7624 if (c_switch_stack && !c_switch_stack->blocked_vm)
7625 c_switch_stack->blocked_vm = scope;
7626 for (glist = label_context_stack_vm->labels_used;
7627 glist != NULL;
7628 glist = glist->next)
7629 {
7630 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7631 }
7632 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7633 nstack->labels_def = NULL;
7634 nstack->labels_used = NULL;
7635 nstack->scope = scope;
7636 nstack->next = label_context_stack_vm;
7637 label_context_stack_vm = nstack;
7638 }
7639
7640 /* End a scope which may contain identifiers of variably modified
7641 type, scope number SCOPE. */
7642
7643 void
7644 c_end_vm_scope (unsigned int scope)
7645 {
7646 if (label_context_stack_vm == NULL)
7647 return;
7648 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7649 c_switch_stack->blocked_vm = 0;
7650 /* We may have a number of nested scopes of identifiers with
7651 variably modified type, all at this depth. Pop each in turn. */
7652 while (label_context_stack_vm->scope == scope)
7653 {
7654 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7655
7656 /* It is no longer possible to jump to labels defined within this
7657 scope. */
7658 for (dlist = label_context_stack_vm->labels_def;
7659 dlist != NULL;
7660 dlist = dlist->next)
7661 {
7662 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7663 }
7664 /* It is again possible to define labels with a goto just outside
7665 this scope. */
7666 for (glist = label_context_stack_vm->next->labels_used;
7667 glist != NULL;
7668 glist = glist->next)
7669 {
7670 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7671 glist_prev = glist;
7672 }
7673 if (glist_prev != NULL)
7674 glist_prev->next = label_context_stack_vm->labels_used;
7675 else
7676 label_context_stack_vm->next->labels_used
7677 = label_context_stack_vm->labels_used;
7678 label_context_stack_vm = label_context_stack_vm->next;
7679 }
7680 }
7681 \f
7682 /* Begin and end compound statements. This is as simple as pushing
7683 and popping new statement lists from the tree. */
7684
7685 tree
7686 c_begin_compound_stmt (bool do_scope)
7687 {
7688 tree stmt = push_stmt_list ();
7689 if (do_scope)
7690 push_scope ();
7691 return stmt;
7692 }
7693
7694 tree
7695 c_end_compound_stmt (tree stmt, bool do_scope)
7696 {
7697 tree block = NULL;
7698
7699 if (do_scope)
7700 {
7701 if (c_dialect_objc ())
7702 objc_clear_super_receiver ();
7703 block = pop_scope ();
7704 }
7705
7706 stmt = pop_stmt_list (stmt);
7707 stmt = c_build_bind_expr (block, stmt);
7708
7709 /* If this compound statement is nested immediately inside a statement
7710 expression, then force a BIND_EXPR to be created. Otherwise we'll
7711 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7712 STATEMENT_LISTs merge, and thus we can lose track of what statement
7713 was really last. */
7714 if (cur_stmt_list
7715 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7716 && TREE_CODE (stmt) != BIND_EXPR)
7717 {
7718 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7719 TREE_SIDE_EFFECTS (stmt) = 1;
7720 }
7721
7722 return stmt;
7723 }
7724
7725 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7726 when the current scope is exited. EH_ONLY is true when this is not
7727 meant to apply to normal control flow transfer. */
7728
7729 void
7730 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7731 {
7732 enum tree_code code;
7733 tree stmt, list;
7734 bool stmt_expr;
7735
7736 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7737 stmt = build_stmt (code, NULL, cleanup);
7738 add_stmt (stmt);
7739 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7740 list = push_stmt_list ();
7741 TREE_OPERAND (stmt, 0) = list;
7742 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7743 }
7744 \f
7745 /* Build a binary-operation expression without default conversions.
7746 CODE is the kind of expression to build.
7747 This function differs from `build' in several ways:
7748 the data type of the result is computed and recorded in it,
7749 warnings are generated if arg data types are invalid,
7750 special handling for addition and subtraction of pointers is known,
7751 and some optimization is done (operations on narrow ints
7752 are done in the narrower type when that gives the same result).
7753 Constant folding is also done before the result is returned.
7754
7755 Note that the operands will never have enumeral types, or function
7756 or array types, because either they will have the default conversions
7757 performed or they have both just been converted to some other type in which
7758 the arithmetic is to be done. */
7759
7760 tree
7761 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7762 int convert_p)
7763 {
7764 tree type0, type1;
7765 enum tree_code code0, code1;
7766 tree op0, op1;
7767 const char *invalid_op_diag;
7768
7769 /* Expression code to give to the expression when it is built.
7770 Normally this is CODE, which is what the caller asked for,
7771 but in some special cases we change it. */
7772 enum tree_code resultcode = code;
7773
7774 /* Data type in which the computation is to be performed.
7775 In the simplest cases this is the common type of the arguments. */
7776 tree result_type = NULL;
7777
7778 /* Nonzero means operands have already been type-converted
7779 in whatever way is necessary.
7780 Zero means they need to be converted to RESULT_TYPE. */
7781 int converted = 0;
7782
7783 /* Nonzero means create the expression with this type, rather than
7784 RESULT_TYPE. */
7785 tree build_type = 0;
7786
7787 /* Nonzero means after finally constructing the expression
7788 convert it to this type. */
7789 tree final_type = 0;
7790
7791 /* Nonzero if this is an operation like MIN or MAX which can
7792 safely be computed in short if both args are promoted shorts.
7793 Also implies COMMON.
7794 -1 indicates a bitwise operation; this makes a difference
7795 in the exact conditions for when it is safe to do the operation
7796 in a narrower mode. */
7797 int shorten = 0;
7798
7799 /* Nonzero if this is a comparison operation;
7800 if both args are promoted shorts, compare the original shorts.
7801 Also implies COMMON. */
7802 int short_compare = 0;
7803
7804 /* Nonzero if this is a right-shift operation, which can be computed on the
7805 original short and then promoted if the operand is a promoted short. */
7806 int short_shift = 0;
7807
7808 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7809 int common = 0;
7810
7811 /* True means types are compatible as far as ObjC is concerned. */
7812 bool objc_ok;
7813
7814 if (convert_p)
7815 {
7816 op0 = default_conversion (orig_op0);
7817 op1 = default_conversion (orig_op1);
7818 }
7819 else
7820 {
7821 op0 = orig_op0;
7822 op1 = orig_op1;
7823 }
7824
7825 type0 = TREE_TYPE (op0);
7826 type1 = TREE_TYPE (op1);
7827
7828 /* The expression codes of the data types of the arguments tell us
7829 whether the arguments are integers, floating, pointers, etc. */
7830 code0 = TREE_CODE (type0);
7831 code1 = TREE_CODE (type1);
7832
7833 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7834 STRIP_TYPE_NOPS (op0);
7835 STRIP_TYPE_NOPS (op1);
7836
7837 /* If an error was already reported for one of the arguments,
7838 avoid reporting another error. */
7839
7840 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7841 return error_mark_node;
7842
7843 if ((invalid_op_diag
7844 = targetm.invalid_binary_op (code, type0, type1)))
7845 {
7846 error (invalid_op_diag);
7847 return error_mark_node;
7848 }
7849
7850 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
7851
7852 switch (code)
7853 {
7854 case PLUS_EXPR:
7855 /* Handle the pointer + int case. */
7856 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7857 return pointer_int_sum (PLUS_EXPR, op0, op1);
7858 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
7859 return pointer_int_sum (PLUS_EXPR, op1, op0);
7860 else
7861 common = 1;
7862 break;
7863
7864 case MINUS_EXPR:
7865 /* Subtraction of two similar pointers.
7866 We must subtract them as integers, then divide by object size. */
7867 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
7868 && comp_target_types (type0, type1))
7869 return pointer_diff (op0, op1);
7870 /* Handle pointer minus int. Just like pointer plus int. */
7871 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7872 return pointer_int_sum (MINUS_EXPR, op0, op1);
7873 else
7874 common = 1;
7875 break;
7876
7877 case MULT_EXPR:
7878 common = 1;
7879 break;
7880
7881 case TRUNC_DIV_EXPR:
7882 case CEIL_DIV_EXPR:
7883 case FLOOR_DIV_EXPR:
7884 case ROUND_DIV_EXPR:
7885 case EXACT_DIV_EXPR:
7886 /* Floating point division by zero is a legitimate way to obtain
7887 infinities and NaNs. */
7888 if (skip_evaluation == 0 && integer_zerop (op1))
7889 warning (OPT_Wdiv_by_zero, "division by zero");
7890
7891 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7892 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7893 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7894 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
7895 {
7896 enum tree_code tcode0 = code0, tcode1 = code1;
7897
7898 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7899 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
7900 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
7901 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
7902
7903 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
7904 resultcode = RDIV_EXPR;
7905 else
7906 /* Although it would be tempting to shorten always here, that
7907 loses on some targets, since the modulo instruction is
7908 undefined if the quotient can't be represented in the
7909 computation mode. We shorten only if unsigned or if
7910 dividing by something we know != -1. */
7911 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7912 || (TREE_CODE (op1) == INTEGER_CST
7913 && !integer_all_onesp (op1)));
7914 common = 1;
7915 }
7916 break;
7917
7918 case BIT_AND_EXPR:
7919 case BIT_IOR_EXPR:
7920 case BIT_XOR_EXPR:
7921 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7922 shorten = -1;
7923 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
7924 common = 1;
7925 break;
7926
7927 case TRUNC_MOD_EXPR:
7928 case FLOOR_MOD_EXPR:
7929 if (skip_evaluation == 0 && integer_zerop (op1))
7930 warning (OPT_Wdiv_by_zero, "division by zero");
7931
7932 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7933 {
7934 /* Although it would be tempting to shorten always here, that loses
7935 on some targets, since the modulo instruction is undefined if the
7936 quotient can't be represented in the computation mode. We shorten
7937 only if unsigned or if dividing by something we know != -1. */
7938 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7939 || (TREE_CODE (op1) == INTEGER_CST
7940 && !integer_all_onesp (op1)));
7941 common = 1;
7942 }
7943 break;
7944
7945 case TRUTH_ANDIF_EXPR:
7946 case TRUTH_ORIF_EXPR:
7947 case TRUTH_AND_EXPR:
7948 case TRUTH_OR_EXPR:
7949 case TRUTH_XOR_EXPR:
7950 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
7951 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
7952 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
7953 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
7954 {
7955 /* Result of these operations is always an int,
7956 but that does not mean the operands should be
7957 converted to ints! */
7958 result_type = integer_type_node;
7959 op0 = c_common_truthvalue_conversion (op0);
7960 op1 = c_common_truthvalue_conversion (op1);
7961 converted = 1;
7962 }
7963 break;
7964
7965 /* Shift operations: result has same type as first operand;
7966 always convert second operand to int.
7967 Also set SHORT_SHIFT if shifting rightward. */
7968
7969 case RSHIFT_EXPR:
7970 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7971 {
7972 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7973 {
7974 if (tree_int_cst_sgn (op1) < 0)
7975 warning (0, "right shift count is negative");
7976 else
7977 {
7978 if (!integer_zerop (op1))
7979 short_shift = 1;
7980
7981 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7982 warning (0, "right shift count >= width of type");
7983 }
7984 }
7985
7986 /* Use the type of the value to be shifted. */
7987 result_type = type0;
7988 /* Convert the shift-count to an integer, regardless of size
7989 of value being shifted. */
7990 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7991 op1 = convert (integer_type_node, op1);
7992 /* Avoid converting op1 to result_type later. */
7993 converted = 1;
7994 }
7995 break;
7996
7997 case LSHIFT_EXPR:
7998 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7999 {
8000 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8001 {
8002 if (tree_int_cst_sgn (op1) < 0)
8003 warning (0, "left shift count is negative");
8004
8005 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8006 warning (0, "left shift count >= width of type");
8007 }
8008
8009 /* Use the type of the value to be shifted. */
8010 result_type = type0;
8011 /* Convert the shift-count to an integer, regardless of size
8012 of value being shifted. */
8013 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8014 op1 = convert (integer_type_node, op1);
8015 /* Avoid converting op1 to result_type later. */
8016 converted = 1;
8017 }
8018 break;
8019
8020 case EQ_EXPR:
8021 case NE_EXPR:
8022 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
8023 warning (OPT_Wfloat_equal,
8024 "comparing floating point with == or != is unsafe");
8025 /* Result of comparison is always int,
8026 but don't convert the args to int! */
8027 build_type = integer_type_node;
8028 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8029 || code0 == COMPLEX_TYPE)
8030 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8031 || code1 == COMPLEX_TYPE))
8032 short_compare = 1;
8033 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8034 {
8035 tree tt0 = TREE_TYPE (type0);
8036 tree tt1 = TREE_TYPE (type1);
8037 /* Anything compares with void *. void * compares with anything.
8038 Otherwise, the targets must be compatible
8039 and both must be object or both incomplete. */
8040 if (comp_target_types (type0, type1))
8041 result_type = common_pointer_type (type0, type1);
8042 else if (VOID_TYPE_P (tt0))
8043 {
8044 /* op0 != orig_op0 detects the case of something
8045 whose value is 0 but which isn't a valid null ptr const. */
8046 if (pedantic && !null_pointer_constant_p (orig_op0)
8047 && TREE_CODE (tt1) == FUNCTION_TYPE)
8048 pedwarn ("ISO C forbids comparison of %<void *%>"
8049 " with function pointer");
8050 }
8051 else if (VOID_TYPE_P (tt1))
8052 {
8053 if (pedantic && !null_pointer_constant_p (orig_op1)
8054 && TREE_CODE (tt0) == FUNCTION_TYPE)
8055 pedwarn ("ISO C forbids comparison of %<void *%>"
8056 " with function pointer");
8057 }
8058 else
8059 /* Avoid warning about the volatile ObjC EH puts on decls. */
8060 if (!objc_ok)
8061 pedwarn ("comparison of distinct pointer types lacks a cast");
8062
8063 if (result_type == NULL_TREE)
8064 result_type = ptr_type_node;
8065 }
8066 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8067 {
8068 if (TREE_CODE (op0) == ADDR_EXPR
8069 && DECL_P (TREE_OPERAND (op0, 0))
8070 && (TREE_CODE (TREE_OPERAND (op0, 0)) == PARM_DECL
8071 || TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL
8072 || !DECL_WEAK (TREE_OPERAND (op0, 0))))
8073 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8074 TREE_OPERAND (op0, 0));
8075 result_type = type0;
8076 }
8077 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8078 {
8079 if (TREE_CODE (op1) == ADDR_EXPR
8080 && DECL_P (TREE_OPERAND (op1, 0))
8081 && (TREE_CODE (TREE_OPERAND (op1, 0)) == PARM_DECL
8082 || TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL
8083 || !DECL_WEAK (TREE_OPERAND (op1, 0))))
8084 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8085 TREE_OPERAND (op1, 0));
8086 result_type = type1;
8087 }
8088 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8089 {
8090 result_type = type0;
8091 pedwarn ("comparison between pointer and integer");
8092 }
8093 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8094 {
8095 result_type = type1;
8096 pedwarn ("comparison between pointer and integer");
8097 }
8098 break;
8099
8100 case LE_EXPR:
8101 case GE_EXPR:
8102 case LT_EXPR:
8103 case GT_EXPR:
8104 build_type = integer_type_node;
8105 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
8106 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
8107 short_compare = 1;
8108 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8109 {
8110 if (comp_target_types (type0, type1))
8111 {
8112 result_type = common_pointer_type (type0, type1);
8113 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8114 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8115 pedwarn ("comparison of complete and incomplete pointers");
8116 else if (pedantic
8117 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8118 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
8119 }
8120 else
8121 {
8122 result_type = ptr_type_node;
8123 pedwarn ("comparison of distinct pointer types lacks a cast");
8124 }
8125 }
8126 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8127 {
8128 result_type = type0;
8129 if (pedantic || extra_warnings)
8130 pedwarn ("ordered comparison of pointer with integer zero");
8131 }
8132 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8133 {
8134 result_type = type1;
8135 if (pedantic)
8136 pedwarn ("ordered comparison of pointer with integer zero");
8137 }
8138 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8139 {
8140 result_type = type0;
8141 pedwarn ("comparison between pointer and integer");
8142 }
8143 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8144 {
8145 result_type = type1;
8146 pedwarn ("comparison between pointer and integer");
8147 }
8148 break;
8149
8150 default:
8151 gcc_unreachable ();
8152 }
8153
8154 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8155 return error_mark_node;
8156
8157 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8158 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8159 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8160 TREE_TYPE (type1))))
8161 {
8162 binary_op_error (code);
8163 return error_mark_node;
8164 }
8165
8166 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8167 || code0 == VECTOR_TYPE)
8168 &&
8169 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8170 || code1 == VECTOR_TYPE))
8171 {
8172 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8173
8174 if (shorten || common || short_compare)
8175 result_type = c_common_type (type0, type1);
8176
8177 /* For certain operations (which identify themselves by shorten != 0)
8178 if both args were extended from the same smaller type,
8179 do the arithmetic in that type and then extend.
8180
8181 shorten !=0 and !=1 indicates a bitwise operation.
8182 For them, this optimization is safe only if
8183 both args are zero-extended or both are sign-extended.
8184 Otherwise, we might change the result.
8185 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8186 but calculated in (unsigned short) it would be (unsigned short)-1. */
8187
8188 if (shorten && none_complex)
8189 {
8190 int unsigned0, unsigned1;
8191 tree arg0, arg1;
8192 int uns;
8193 tree type;
8194
8195 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8196 excessive narrowing when we call get_narrower below. For
8197 example, suppose that OP0 is of unsigned int extended
8198 from signed char and that RESULT_TYPE is long long int.
8199 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8200 like
8201
8202 (long long int) (unsigned int) signed_char
8203
8204 which get_narrower would narrow down to
8205
8206 (unsigned int) signed char
8207
8208 If we do not cast OP0 first, get_narrower would return
8209 signed_char, which is inconsistent with the case of the
8210 explicit cast. */
8211 op0 = convert (result_type, op0);
8212 op1 = convert (result_type, op1);
8213
8214 arg0 = get_narrower (op0, &unsigned0);
8215 arg1 = get_narrower (op1, &unsigned1);
8216
8217 /* UNS is 1 if the operation to be done is an unsigned one. */
8218 uns = TYPE_UNSIGNED (result_type);
8219
8220 final_type = result_type;
8221
8222 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8223 but it *requires* conversion to FINAL_TYPE. */
8224
8225 if ((TYPE_PRECISION (TREE_TYPE (op0))
8226 == TYPE_PRECISION (TREE_TYPE (arg0)))
8227 && TREE_TYPE (op0) != final_type)
8228 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
8229 if ((TYPE_PRECISION (TREE_TYPE (op1))
8230 == TYPE_PRECISION (TREE_TYPE (arg1)))
8231 && TREE_TYPE (op1) != final_type)
8232 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
8233
8234 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8235
8236 /* For bitwise operations, signedness of nominal type
8237 does not matter. Consider only how operands were extended. */
8238 if (shorten == -1)
8239 uns = unsigned0;
8240
8241 /* Note that in all three cases below we refrain from optimizing
8242 an unsigned operation on sign-extended args.
8243 That would not be valid. */
8244
8245 /* Both args variable: if both extended in same way
8246 from same width, do it in that width.
8247 Do it unsigned if args were zero-extended. */
8248 if ((TYPE_PRECISION (TREE_TYPE (arg0))
8249 < TYPE_PRECISION (result_type))
8250 && (TYPE_PRECISION (TREE_TYPE (arg1))
8251 == TYPE_PRECISION (TREE_TYPE (arg0)))
8252 && unsigned0 == unsigned1
8253 && (unsigned0 || !uns))
8254 result_type
8255 = c_common_signed_or_unsigned_type
8256 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
8257 else if (TREE_CODE (arg0) == INTEGER_CST
8258 && (unsigned1 || !uns)
8259 && (TYPE_PRECISION (TREE_TYPE (arg1))
8260 < TYPE_PRECISION (result_type))
8261 && (type
8262 = c_common_signed_or_unsigned_type (unsigned1,
8263 TREE_TYPE (arg1)),
8264 int_fits_type_p (arg0, type)))
8265 result_type = type;
8266 else if (TREE_CODE (arg1) == INTEGER_CST
8267 && (unsigned0 || !uns)
8268 && (TYPE_PRECISION (TREE_TYPE (arg0))
8269 < TYPE_PRECISION (result_type))
8270 && (type
8271 = c_common_signed_or_unsigned_type (unsigned0,
8272 TREE_TYPE (arg0)),
8273 int_fits_type_p (arg1, type)))
8274 result_type = type;
8275 }
8276
8277 /* Shifts can be shortened if shifting right. */
8278
8279 if (short_shift)
8280 {
8281 int unsigned_arg;
8282 tree arg0 = get_narrower (op0, &unsigned_arg);
8283
8284 final_type = result_type;
8285
8286 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8287 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8288
8289 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8290 /* We can shorten only if the shift count is less than the
8291 number of bits in the smaller type size. */
8292 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8293 /* We cannot drop an unsigned shift after sign-extension. */
8294 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8295 {
8296 /* Do an unsigned shift if the operand was zero-extended. */
8297 result_type
8298 = c_common_signed_or_unsigned_type (unsigned_arg,
8299 TREE_TYPE (arg0));
8300 /* Convert value-to-be-shifted to that type. */
8301 if (TREE_TYPE (op0) != result_type)
8302 op0 = convert (result_type, op0);
8303 converted = 1;
8304 }
8305 }
8306
8307 /* Comparison operations are shortened too but differently.
8308 They identify themselves by setting short_compare = 1. */
8309
8310 if (short_compare)
8311 {
8312 /* Don't write &op0, etc., because that would prevent op0
8313 from being kept in a register.
8314 Instead, make copies of the our local variables and
8315 pass the copies by reference, then copy them back afterward. */
8316 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8317 enum tree_code xresultcode = resultcode;
8318 tree val
8319 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8320
8321 if (val != 0)
8322 return val;
8323
8324 op0 = xop0, op1 = xop1;
8325 converted = 1;
8326 resultcode = xresultcode;
8327
8328 if (warn_sign_compare && skip_evaluation == 0)
8329 {
8330 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8331 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8332 int unsignedp0, unsignedp1;
8333 tree primop0 = get_narrower (op0, &unsignedp0);
8334 tree primop1 = get_narrower (op1, &unsignedp1);
8335
8336 xop0 = orig_op0;
8337 xop1 = orig_op1;
8338 STRIP_TYPE_NOPS (xop0);
8339 STRIP_TYPE_NOPS (xop1);
8340
8341 /* Give warnings for comparisons between signed and unsigned
8342 quantities that may fail.
8343
8344 Do the checking based on the original operand trees, so that
8345 casts will be considered, but default promotions won't be.
8346
8347 Do not warn if the comparison is being done in a signed type,
8348 since the signed type will only be chosen if it can represent
8349 all the values of the unsigned type. */
8350 if (!TYPE_UNSIGNED (result_type))
8351 /* OK */;
8352 /* Do not warn if both operands are the same signedness. */
8353 else if (op0_signed == op1_signed)
8354 /* OK */;
8355 else
8356 {
8357 tree sop, uop;
8358
8359 if (op0_signed)
8360 sop = xop0, uop = xop1;
8361 else
8362 sop = xop1, uop = xop0;
8363
8364 /* Do not warn if the signed quantity is an
8365 unsuffixed integer literal (or some static
8366 constant expression involving such literals or a
8367 conditional expression involving such literals)
8368 and it is non-negative. */
8369 if (tree_expr_nonnegative_p (sop))
8370 /* OK */;
8371 /* Do not warn if the comparison is an equality operation,
8372 the unsigned quantity is an integral constant, and it
8373 would fit in the result if the result were signed. */
8374 else if (TREE_CODE (uop) == INTEGER_CST
8375 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8376 && int_fits_type_p
8377 (uop, c_common_signed_type (result_type)))
8378 /* OK */;
8379 /* Do not warn if the unsigned quantity is an enumeration
8380 constant and its maximum value would fit in the result
8381 if the result were signed. */
8382 else if (TREE_CODE (uop) == INTEGER_CST
8383 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8384 && int_fits_type_p
8385 (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8386 c_common_signed_type (result_type)))
8387 /* OK */;
8388 else
8389 warning (0, "comparison between signed and unsigned");
8390 }
8391
8392 /* Warn if two unsigned values are being compared in a size
8393 larger than their original size, and one (and only one) is the
8394 result of a `~' operator. This comparison will always fail.
8395
8396 Also warn if one operand is a constant, and the constant
8397 does not have all bits set that are set in the ~ operand
8398 when it is extended. */
8399
8400 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
8401 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
8402 {
8403 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
8404 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
8405 &unsignedp0);
8406 else
8407 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
8408 &unsignedp1);
8409
8410 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
8411 {
8412 tree primop;
8413 HOST_WIDE_INT constant, mask;
8414 int unsignedp, bits;
8415
8416 if (host_integerp (primop0, 0))
8417 {
8418 primop = primop1;
8419 unsignedp = unsignedp1;
8420 constant = tree_low_cst (primop0, 0);
8421 }
8422 else
8423 {
8424 primop = primop0;
8425 unsignedp = unsignedp0;
8426 constant = tree_low_cst (primop1, 0);
8427 }
8428
8429 bits = TYPE_PRECISION (TREE_TYPE (primop));
8430 if (bits < TYPE_PRECISION (result_type)
8431 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
8432 {
8433 mask = (~(HOST_WIDE_INT) 0) << bits;
8434 if ((mask & constant) != mask)
8435 warning (0, "comparison of promoted ~unsigned with constant");
8436 }
8437 }
8438 else if (unsignedp0 && unsignedp1
8439 && (TYPE_PRECISION (TREE_TYPE (primop0))
8440 < TYPE_PRECISION (result_type))
8441 && (TYPE_PRECISION (TREE_TYPE (primop1))
8442 < TYPE_PRECISION (result_type)))
8443 warning (0, "comparison of promoted ~unsigned with unsigned");
8444 }
8445 }
8446 }
8447 }
8448
8449 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8450 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8451 Then the expression will be built.
8452 It will be given type FINAL_TYPE if that is nonzero;
8453 otherwise, it will be given type RESULT_TYPE. */
8454
8455 if (!result_type)
8456 {
8457 binary_op_error (code);
8458 return error_mark_node;
8459 }
8460
8461 if (!converted)
8462 {
8463 if (TREE_TYPE (op0) != result_type)
8464 op0 = convert_and_check (result_type, op0);
8465 if (TREE_TYPE (op1) != result_type)
8466 op1 = convert_and_check (result_type, op1);
8467
8468 /* This can happen if one operand has a vector type, and the other
8469 has a different type. */
8470 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8471 return error_mark_node;
8472 }
8473
8474 if (build_type == NULL_TREE)
8475 build_type = result_type;
8476
8477 {
8478 /* Treat expressions in initializers specially as they can't trap. */
8479 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8480 build_type,
8481 op0, op1)
8482 : fold_build2 (resultcode, build_type,
8483 op0, op1);
8484
8485 if (final_type != 0)
8486 result = convert (final_type, result);
8487 return result;
8488 }
8489 }
8490
8491
8492 /* Convert EXPR to be a truth-value, validating its type for this
8493 purpose. */
8494
8495 tree
8496 c_objc_common_truthvalue_conversion (tree expr)
8497 {
8498 switch (TREE_CODE (TREE_TYPE (expr)))
8499 {
8500 case ARRAY_TYPE:
8501 error ("used array that cannot be converted to pointer where scalar is required");
8502 return error_mark_node;
8503
8504 case RECORD_TYPE:
8505 error ("used struct type value where scalar is required");
8506 return error_mark_node;
8507
8508 case UNION_TYPE:
8509 error ("used union type value where scalar is required");
8510 return error_mark_node;
8511
8512 case FUNCTION_TYPE:
8513 gcc_unreachable ();
8514
8515 default:
8516 break;
8517 }
8518
8519 /* ??? Should we also give an error for void and vectors rather than
8520 leaving those to give errors later? */
8521 return c_common_truthvalue_conversion (expr);
8522 }
8523 \f
8524
8525 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8526 required. */
8527
8528 tree
8529 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
8530 bool *ti ATTRIBUTE_UNUSED, bool *se)
8531 {
8532 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8533 {
8534 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8535 /* Executing a compound literal inside a function reinitializes
8536 it. */
8537 if (!TREE_STATIC (decl))
8538 *se = true;
8539 return decl;
8540 }
8541 else
8542 return expr;
8543 }
8544 \f
8545 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8546
8547 tree
8548 c_begin_omp_parallel (void)
8549 {
8550 tree block;
8551
8552 keep_next_level ();
8553 block = c_begin_compound_stmt (true);
8554
8555 return block;
8556 }
8557
8558 tree
8559 c_finish_omp_parallel (tree clauses, tree block)
8560 {
8561 tree stmt;
8562
8563 block = c_end_compound_stmt (block, true);
8564
8565 stmt = make_node (OMP_PARALLEL);
8566 TREE_TYPE (stmt) = void_type_node;
8567 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8568 OMP_PARALLEL_BODY (stmt) = block;
8569
8570 return add_stmt (stmt);
8571 }
8572
8573 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8574 Remove any elements from the list that are invalid. */
8575
8576 tree
8577 c_finish_omp_clauses (tree clauses)
8578 {
8579 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8580 tree c, t, *pc = &clauses;
8581 const char *name;
8582
8583 bitmap_obstack_initialize (NULL);
8584 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8585 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8586 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8587
8588 for (pc = &clauses, c = clauses; c ; c = *pc)
8589 {
8590 bool remove = false;
8591 bool need_complete = false;
8592 bool need_implicitly_determined = false;
8593
8594 switch (OMP_CLAUSE_CODE (c))
8595 {
8596 case OMP_CLAUSE_SHARED:
8597 name = "shared";
8598 need_implicitly_determined = true;
8599 goto check_dup_generic;
8600
8601 case OMP_CLAUSE_PRIVATE:
8602 name = "private";
8603 need_complete = true;
8604 need_implicitly_determined = true;
8605 goto check_dup_generic;
8606
8607 case OMP_CLAUSE_REDUCTION:
8608 name = "reduction";
8609 need_implicitly_determined = true;
8610 t = OMP_CLAUSE_DECL (c);
8611 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8612 || POINTER_TYPE_P (TREE_TYPE (t)))
8613 {
8614 error ("%qE has invalid type for %<reduction%>", t);
8615 remove = true;
8616 }
8617 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8618 {
8619 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8620 const char *r_name = NULL;
8621
8622 switch (r_code)
8623 {
8624 case PLUS_EXPR:
8625 case MULT_EXPR:
8626 case MINUS_EXPR:
8627 break;
8628 case BIT_AND_EXPR:
8629 r_name = "&";
8630 break;
8631 case BIT_XOR_EXPR:
8632 r_name = "^";
8633 break;
8634 case BIT_IOR_EXPR:
8635 r_name = "|";
8636 break;
8637 case TRUTH_ANDIF_EXPR:
8638 r_name = "&&";
8639 break;
8640 case TRUTH_ORIF_EXPR:
8641 r_name = "||";
8642 break;
8643 default:
8644 gcc_unreachable ();
8645 }
8646 if (r_name)
8647 {
8648 error ("%qE has invalid type for %<reduction(%s)%>",
8649 t, r_name);
8650 remove = true;
8651 }
8652 }
8653 goto check_dup_generic;
8654
8655 case OMP_CLAUSE_COPYPRIVATE:
8656 name = "copyprivate";
8657 goto check_dup_generic;
8658
8659 case OMP_CLAUSE_COPYIN:
8660 name = "copyin";
8661 t = OMP_CLAUSE_DECL (c);
8662 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8663 {
8664 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8665 remove = true;
8666 }
8667 goto check_dup_generic;
8668
8669 check_dup_generic:
8670 t = OMP_CLAUSE_DECL (c);
8671 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8672 {
8673 error ("%qE is not a variable in clause %qs", t, name);
8674 remove = true;
8675 }
8676 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8677 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8678 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8679 {
8680 error ("%qE appears more than once in data clauses", t);
8681 remove = true;
8682 }
8683 else
8684 bitmap_set_bit (&generic_head, DECL_UID (t));
8685 break;
8686
8687 case OMP_CLAUSE_FIRSTPRIVATE:
8688 name = "firstprivate";
8689 t = OMP_CLAUSE_DECL (c);
8690 need_complete = true;
8691 need_implicitly_determined = true;
8692 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8693 {
8694 error ("%qE is not a variable in clause %<firstprivate%>", t);
8695 remove = true;
8696 }
8697 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8698 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8699 {
8700 error ("%qE appears more than once in data clauses", t);
8701 remove = true;
8702 }
8703 else
8704 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8705 break;
8706
8707 case OMP_CLAUSE_LASTPRIVATE:
8708 name = "lastprivate";
8709 t = OMP_CLAUSE_DECL (c);
8710 need_complete = true;
8711 need_implicitly_determined = true;
8712 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8713 {
8714 error ("%qE is not a variable in clause %<lastprivate%>", t);
8715 remove = true;
8716 }
8717 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8718 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8719 {
8720 error ("%qE appears more than once in data clauses", t);
8721 remove = true;
8722 }
8723 else
8724 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8725 break;
8726
8727 case OMP_CLAUSE_IF:
8728 case OMP_CLAUSE_NUM_THREADS:
8729 case OMP_CLAUSE_SCHEDULE:
8730 case OMP_CLAUSE_NOWAIT:
8731 case OMP_CLAUSE_ORDERED:
8732 case OMP_CLAUSE_DEFAULT:
8733 pc = &OMP_CLAUSE_CHAIN (c);
8734 continue;
8735
8736 default:
8737 gcc_unreachable ();
8738 }
8739
8740 if (!remove)
8741 {
8742 t = OMP_CLAUSE_DECL (c);
8743
8744 if (need_complete)
8745 {
8746 t = require_complete_type (t);
8747 if (t == error_mark_node)
8748 remove = true;
8749 }
8750
8751 if (need_implicitly_determined)
8752 {
8753 const char *share_name = NULL;
8754
8755 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8756 share_name = "threadprivate";
8757 else switch (c_omp_predetermined_sharing (t))
8758 {
8759 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8760 break;
8761 case OMP_CLAUSE_DEFAULT_SHARED:
8762 share_name = "shared";
8763 break;
8764 case OMP_CLAUSE_DEFAULT_PRIVATE:
8765 share_name = "private";
8766 break;
8767 default:
8768 gcc_unreachable ();
8769 }
8770 if (share_name)
8771 {
8772 error ("%qE is predetermined %qs for %qs",
8773 t, share_name, name);
8774 remove = true;
8775 }
8776 }
8777 }
8778
8779 if (remove)
8780 *pc = OMP_CLAUSE_CHAIN (c);
8781 else
8782 pc = &OMP_CLAUSE_CHAIN (c);
8783 }
8784
8785 bitmap_obstack_release (NULL);
8786 return clauses;
8787 }
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