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Daily bump.
[official-gcc.git] / gcc / c-typeck.c
blob1b0e33a794683afb42e88608818027802b833426
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 /* C99 6.7.4p3: An inline definition of a function with external
2113 linkage ... shall not contain a reference to an identifier with
2114 internal linkage. */
2115 else if (current_function_decl != 0
2116 && DECL_DECLARED_INLINE_P (current_function_decl)
2117 && DECL_EXTERNAL (current_function_decl)
2118 && VAR_OR_FUNCTION_DECL_P (ref)
2119 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref))
2120 && ! TREE_PUBLIC (ref))
2121 pedwarn ("%H%qD is static but used in inline function %qD "
2122 "which is not static", &loc, ref, current_function_decl);
2123
2124 return ref;
2125 }
2126
2127 /* Record details of decls possibly used inside sizeof or typeof. */
2128 struct maybe_used_decl
2129 {
2130 /* The decl. */
2131 tree decl;
2132 /* The level seen at (in_sizeof + in_typeof). */
2133 int level;
2134 /* The next one at this level or above, or NULL. */
2135 struct maybe_used_decl *next;
2136 };
2137
2138 static struct maybe_used_decl *maybe_used_decls;
2139
2140 /* Record that DECL, an undefined static function reference seen
2141 inside sizeof or typeof, might be used if the operand of sizeof is
2142 a VLA type or the operand of typeof is a variably modified
2143 type. */
2144
2145 static void
2146 record_maybe_used_decl (tree decl)
2147 {
2148 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2149 t->decl = decl;
2150 t->level = in_sizeof + in_typeof;
2151 t->next = maybe_used_decls;
2152 maybe_used_decls = t;
2153 }
2154
2155 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2156 USED is false, just discard them. If it is true, mark them used
2157 (if no longer inside sizeof or typeof) or move them to the next
2158 level up (if still inside sizeof or typeof). */
2159
2160 void
2161 pop_maybe_used (bool used)
2162 {
2163 struct maybe_used_decl *p = maybe_used_decls;
2164 int cur_level = in_sizeof + in_typeof;
2165 while (p && p->level > cur_level)
2166 {
2167 if (used)
2168 {
2169 if (cur_level == 0)
2170 C_DECL_USED (p->decl) = 1;
2171 else
2172 p->level = cur_level;
2173 }
2174 p = p->next;
2175 }
2176 if (!used || cur_level == 0)
2177 maybe_used_decls = p;
2178 }
2179
2180 /* Return the result of sizeof applied to EXPR. */
2181
2182 struct c_expr
2183 c_expr_sizeof_expr (struct c_expr expr)
2184 {
2185 struct c_expr ret;
2186 if (expr.value == error_mark_node)
2187 {
2188 ret.value = error_mark_node;
2189 ret.original_code = ERROR_MARK;
2190 pop_maybe_used (false);
2191 }
2192 else
2193 {
2194 ret.value = c_sizeof (TREE_TYPE (expr.value));
2195 ret.original_code = ERROR_MARK;
2196 if (c_vla_type_p (TREE_TYPE (expr.value)))
2197 {
2198 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2199 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2200 }
2201 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2202 }
2203 return ret;
2204 }
2205
2206 /* Return the result of sizeof applied to T, a structure for the type
2207 name passed to sizeof (rather than the type itself). */
2208
2209 struct c_expr
2210 c_expr_sizeof_type (struct c_type_name *t)
2211 {
2212 tree type;
2213 struct c_expr ret;
2214 type = groktypename (t);
2215 ret.value = c_sizeof (type);
2216 ret.original_code = ERROR_MARK;
2217 pop_maybe_used (type != error_mark_node
2218 ? C_TYPE_VARIABLE_SIZE (type) : false);
2219 return ret;
2220 }
2221
2222 /* Build a function call to function FUNCTION with parameters PARAMS.
2223 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2224 TREE_VALUE of each node is a parameter-expression.
2225 FUNCTION's data type may be a function type or a pointer-to-function. */
2226
2227 tree
2228 build_function_call (tree function, tree params)
2229 {
2230 tree fntype, fundecl = 0;
2231 tree coerced_params;
2232 tree name = NULL_TREE, result;
2233 tree tem;
2234
2235 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2236 STRIP_TYPE_NOPS (function);
2237
2238 /* Convert anything with function type to a pointer-to-function. */
2239 if (TREE_CODE (function) == FUNCTION_DECL)
2240 {
2241 /* Implement type-directed function overloading for builtins.
2242 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2243 handle all the type checking. The result is a complete expression
2244 that implements this function call. */
2245 tem = resolve_overloaded_builtin (function, params);
2246 if (tem)
2247 return tem;
2248
2249 name = DECL_NAME (function);
2250 fundecl = function;
2251 }
2252 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2253 function = function_to_pointer_conversion (function);
2254
2255 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2256 expressions, like those used for ObjC messenger dispatches. */
2257 function = objc_rewrite_function_call (function, params);
2258
2259 fntype = TREE_TYPE (function);
2260
2261 if (TREE_CODE (fntype) == ERROR_MARK)
2262 return error_mark_node;
2263
2264 if (!(TREE_CODE (fntype) == POINTER_TYPE
2265 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2266 {
2267 error ("called object %qE is not a function", function);
2268 return error_mark_node;
2269 }
2270
2271 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2272 current_function_returns_abnormally = 1;
2273
2274 /* fntype now gets the type of function pointed to. */
2275 fntype = TREE_TYPE (fntype);
2276
2277 /* Check that the function is called through a compatible prototype.
2278 If it is not, replace the call by a trap, wrapped up in a compound
2279 expression if necessary. This has the nice side-effect to prevent
2280 the tree-inliner from generating invalid assignment trees which may
2281 blow up in the RTL expander later. */
2282 if ((TREE_CODE (function) == NOP_EXPR
2283 || TREE_CODE (function) == CONVERT_EXPR)
2284 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2285 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2286 && !comptypes (fntype, TREE_TYPE (tem)))
2287 {
2288 tree return_type = TREE_TYPE (fntype);
2289 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2290 NULL_TREE);
2291
2292 /* This situation leads to run-time undefined behavior. We can't,
2293 therefore, simply error unless we can prove that all possible
2294 executions of the program must execute the code. */
2295 warning (0, "function called through a non-compatible type");
2296
2297 /* We can, however, treat "undefined" any way we please.
2298 Call abort to encourage the user to fix the program. */
2299 inform ("if this code is reached, the program will abort");
2300
2301 if (VOID_TYPE_P (return_type))
2302 return trap;
2303 else
2304 {
2305 tree rhs;
2306
2307 if (AGGREGATE_TYPE_P (return_type))
2308 rhs = build_compound_literal (return_type,
2309 build_constructor (return_type, 0));
2310 else
2311 rhs = fold_convert (return_type, integer_zero_node);
2312
2313 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2314 }
2315 }
2316
2317 /* Convert the parameters to the types declared in the
2318 function prototype, or apply default promotions. */
2319
2320 coerced_params
2321 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl);
2322
2323 if (coerced_params == error_mark_node)
2324 return error_mark_node;
2325
2326 /* Check that the arguments to the function are valid. */
2327
2328 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2329 TYPE_ARG_TYPES (fntype));
2330
2331 if (require_constant_value)
2332 {
2333 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype),
2334 function, coerced_params, NULL_TREE);
2335
2336 if (TREE_CONSTANT (result)
2337 && (name == NULL_TREE
2338 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2339 pedwarn_init ("initializer element is not constant");
2340 }
2341 else
2342 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype),
2343 function, coerced_params, NULL_TREE);
2344
2345 if (VOID_TYPE_P (TREE_TYPE (result)))
2346 return result;
2347 return require_complete_type (result);
2348 }
2349 \f
2350 /* Convert the argument expressions in the list VALUES
2351 to the types in the list TYPELIST. The result is a list of converted
2352 argument expressions, unless there are too few arguments in which
2353 case it is error_mark_node.
2354
2355 If TYPELIST is exhausted, or when an element has NULL as its type,
2356 perform the default conversions.
2357
2358 PARMLIST is the chain of parm decls for the function being called.
2359 It may be 0, if that info is not available.
2360 It is used only for generating error messages.
2361
2362 FUNCTION is a tree for the called function. It is used only for
2363 error messages, where it is formatted with %qE.
2364
2365 This is also where warnings about wrong number of args are generated.
2366
2367 Both VALUES and the returned value are chains of TREE_LIST nodes
2368 with the elements of the list in the TREE_VALUE slots of those nodes. */
2369
2370 static tree
2371 convert_arguments (tree typelist, tree values, tree function, tree fundecl)
2372 {
2373 tree typetail, valtail;
2374 tree result = NULL;
2375 int parmnum;
2376 tree selector;
2377
2378 /* Change pointer to function to the function itself for
2379 diagnostics. */
2380 if (TREE_CODE (function) == ADDR_EXPR
2381 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2382 function = TREE_OPERAND (function, 0);
2383
2384 /* Handle an ObjC selector specially for diagnostics. */
2385 selector = objc_message_selector ();
2386
2387 /* Scan the given expressions and types, producing individual
2388 converted arguments and pushing them on RESULT in reverse order. */
2389
2390 for (valtail = values, typetail = typelist, parmnum = 0;
2391 valtail;
2392 valtail = TREE_CHAIN (valtail), parmnum++)
2393 {
2394 tree type = typetail ? TREE_VALUE (typetail) : 0;
2395 tree val = TREE_VALUE (valtail);
2396 tree rname = function;
2397 int argnum = parmnum + 1;
2398 const char *invalid_func_diag;
2399
2400 if (type == void_type_node)
2401 {
2402 error ("too many arguments to function %qE", function);
2403 break;
2404 }
2405
2406 if (selector && argnum > 2)
2407 {
2408 rname = selector;
2409 argnum -= 2;
2410 }
2411
2412 STRIP_TYPE_NOPS (val);
2413
2414 val = require_complete_type (val);
2415
2416 if (type != 0)
2417 {
2418 /* Formal parm type is specified by a function prototype. */
2419 tree parmval;
2420
2421 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2422 {
2423 error ("type of formal parameter %d is incomplete", parmnum + 1);
2424 parmval = val;
2425 }
2426 else
2427 {
2428 /* Optionally warn about conversions that
2429 differ from the default conversions. */
2430 if (warn_traditional_conversion || warn_traditional)
2431 {
2432 unsigned int formal_prec = TYPE_PRECISION (type);
2433
2434 if (INTEGRAL_TYPE_P (type)
2435 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2436 warning (0, "passing argument %d of %qE as integer "
2437 "rather than floating due to prototype",
2438 argnum, rname);
2439 if (INTEGRAL_TYPE_P (type)
2440 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2441 warning (0, "passing argument %d of %qE as integer "
2442 "rather than complex due to prototype",
2443 argnum, rname);
2444 else if (TREE_CODE (type) == COMPLEX_TYPE
2445 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2446 warning (0, "passing argument %d of %qE as complex "
2447 "rather than floating due to prototype",
2448 argnum, rname);
2449 else if (TREE_CODE (type) == REAL_TYPE
2450 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2451 warning (0, "passing argument %d of %qE as floating "
2452 "rather than integer due to prototype",
2453 argnum, rname);
2454 else if (TREE_CODE (type) == COMPLEX_TYPE
2455 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2456 warning (0, "passing argument %d of %qE as complex "
2457 "rather than integer due to prototype",
2458 argnum, rname);
2459 else if (TREE_CODE (type) == REAL_TYPE
2460 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2461 warning (0, "passing argument %d of %qE as floating "
2462 "rather than complex due to prototype",
2463 argnum, rname);
2464 /* ??? At some point, messages should be written about
2465 conversions between complex types, but that's too messy
2466 to do now. */
2467 else if (TREE_CODE (type) == REAL_TYPE
2468 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2469 {
2470 /* Warn if any argument is passed as `float',
2471 since without a prototype it would be `double'. */
2472 if (formal_prec == TYPE_PRECISION (float_type_node)
2473 && type != dfloat32_type_node)
2474 warning (0, "passing argument %d of %qE as %<float%> "
2475 "rather than %<double%> due to prototype",
2476 argnum, rname);
2477
2478 /* Warn if mismatch between argument and prototype
2479 for decimal float types. Warn of conversions with
2480 binary float types and of precision narrowing due to
2481 prototype. */
2482 else if (type != TREE_TYPE (val)
2483 && (type == dfloat32_type_node
2484 || type == dfloat64_type_node
2485 || type == dfloat128_type_node
2486 || TREE_TYPE (val) == dfloat32_type_node
2487 || TREE_TYPE (val) == dfloat64_type_node
2488 || TREE_TYPE (val) == dfloat128_type_node)
2489 && (formal_prec
2490 <= TYPE_PRECISION (TREE_TYPE (val))
2491 || (type == dfloat128_type_node
2492 && (TREE_TYPE (val)
2493 != dfloat64_type_node
2494 && (TREE_TYPE (val)
2495 != dfloat32_type_node)))
2496 || (type == dfloat64_type_node
2497 && (TREE_TYPE (val)
2498 != dfloat32_type_node))))
2499 warning (0, "passing argument %d of %qE as %qT "
2500 "rather than %qT due to prototype",
2501 argnum, rname, type, TREE_TYPE (val));
2502
2503 }
2504 /* Detect integer changing in width or signedness.
2505 These warnings are only activated with
2506 -Wtraditional-conversion, not with -Wtraditional. */
2507 else if (warn_traditional_conversion && INTEGRAL_TYPE_P (type)
2508 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2509 {
2510 tree would_have_been = default_conversion (val);
2511 tree type1 = TREE_TYPE (would_have_been);
2512
2513 if (TREE_CODE (type) == ENUMERAL_TYPE
2514 && (TYPE_MAIN_VARIANT (type)
2515 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2516 /* No warning if function asks for enum
2517 and the actual arg is that enum type. */
2518 ;
2519 else if (formal_prec != TYPE_PRECISION (type1))
2520 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2521 "with different width due to prototype",
2522 argnum, rname);
2523 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2524 ;
2525 /* Don't complain if the formal parameter type
2526 is an enum, because we can't tell now whether
2527 the value was an enum--even the same enum. */
2528 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2529 ;
2530 else if (TREE_CODE (val) == INTEGER_CST
2531 && int_fits_type_p (val, type))
2532 /* Change in signedness doesn't matter
2533 if a constant value is unaffected. */
2534 ;
2535 /* If the value is extended from a narrower
2536 unsigned type, it doesn't matter whether we
2537 pass it as signed or unsigned; the value
2538 certainly is the same either way. */
2539 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2540 && TYPE_UNSIGNED (TREE_TYPE (val)))
2541 ;
2542 else if (TYPE_UNSIGNED (type))
2543 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2544 "as unsigned due to prototype",
2545 argnum, rname);
2546 else
2547 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2548 "as signed due to prototype", argnum, rname);
2549 }
2550 }
2551
2552 parmval = convert_for_assignment (type, val, ic_argpass,
2553 fundecl, function,
2554 parmnum + 1);
2555
2556 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2557 && INTEGRAL_TYPE_P (type)
2558 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2559 parmval = default_conversion (parmval);
2560 }
2561 result = tree_cons (NULL_TREE, parmval, result);
2562 }
2563 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2564 && (TYPE_PRECISION (TREE_TYPE (val))
2565 < TYPE_PRECISION (double_type_node))
2566 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2567 /* Convert `float' to `double'. */
2568 result = tree_cons (NULL_TREE, convert (double_type_node, val), result);
2569 else if ((invalid_func_diag =
2570 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2571 {
2572 error (invalid_func_diag);
2573 return error_mark_node;
2574 }
2575 else
2576 /* Convert `short' and `char' to full-size `int'. */
2577 result = tree_cons (NULL_TREE, default_conversion (val), result);
2578
2579 if (typetail)
2580 typetail = TREE_CHAIN (typetail);
2581 }
2582
2583 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2584 {
2585 error ("too few arguments to function %qE", function);
2586 return error_mark_node;
2587 }
2588
2589 return nreverse (result);
2590 }
2591 \f
2592 /* This is the entry point used by the parser to build unary operators
2593 in the input. CODE, a tree_code, specifies the unary operator, and
2594 ARG is the operand. For unary plus, the C parser currently uses
2595 CONVERT_EXPR for code. */
2596
2597 struct c_expr
2598 parser_build_unary_op (enum tree_code code, struct c_expr arg)
2599 {
2600 struct c_expr result;
2601
2602 result.original_code = ERROR_MARK;
2603 result.value = build_unary_op (code, arg.value, 0);
2604 overflow_warning (result.value);
2605 return result;
2606 }
2607
2608 /* This is the entry point used by the parser to build binary operators
2609 in the input. CODE, a tree_code, specifies the binary operator, and
2610 ARG1 and ARG2 are the operands. In addition to constructing the
2611 expression, we check for operands that were written with other binary
2612 operators in a way that is likely to confuse the user. */
2613
2614 struct c_expr
2615 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2616 struct c_expr arg2)
2617 {
2618 struct c_expr result;
2619
2620 enum tree_code code1 = arg1.original_code;
2621 enum tree_code code2 = arg2.original_code;
2622
2623 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2624 result.original_code = code;
2625
2626 if (TREE_CODE (result.value) == ERROR_MARK)
2627 return result;
2628
2629 /* Check for cases such as x+y<<z which users are likely
2630 to misinterpret. */
2631 if (warn_parentheses)
2632 {
2633 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
2634 {
2635 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
2636 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2637 warning (OPT_Wparentheses,
2638 "suggest parentheses around + or - inside shift");
2639 }
2640
2641 if (code == TRUTH_ORIF_EXPR)
2642 {
2643 if (code1 == TRUTH_ANDIF_EXPR
2644 || code2 == TRUTH_ANDIF_EXPR)
2645 warning (OPT_Wparentheses,
2646 "suggest parentheses around && within ||");
2647 }
2648
2649 if (code == BIT_IOR_EXPR)
2650 {
2651 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR
2652 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
2653 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR
2654 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2655 warning (OPT_Wparentheses,
2656 "suggest parentheses around arithmetic in operand of |");
2657 /* Check cases like x|y==z */
2658 if (TREE_CODE_CLASS (code1) == tcc_comparison
2659 || TREE_CODE_CLASS (code2) == tcc_comparison)
2660 warning (OPT_Wparentheses,
2661 "suggest parentheses around comparison in operand of |");
2662 }
2663
2664 if (code == BIT_XOR_EXPR)
2665 {
2666 if (code1 == BIT_AND_EXPR
2667 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
2668 || code2 == BIT_AND_EXPR
2669 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2670 warning (OPT_Wparentheses,
2671 "suggest parentheses around arithmetic in operand of ^");
2672 /* Check cases like x^y==z */
2673 if (TREE_CODE_CLASS (code1) == tcc_comparison
2674 || TREE_CODE_CLASS (code2) == tcc_comparison)
2675 warning (OPT_Wparentheses,
2676 "suggest parentheses around comparison in operand of ^");
2677 }
2678
2679 if (code == BIT_AND_EXPR)
2680 {
2681 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
2682 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2683 warning (OPT_Wparentheses,
2684 "suggest parentheses around + or - in operand of &");
2685 /* Check cases like x&y==z */
2686 if (TREE_CODE_CLASS (code1) == tcc_comparison
2687 || TREE_CODE_CLASS (code2) == tcc_comparison)
2688 warning (OPT_Wparentheses,
2689 "suggest parentheses around comparison in operand of &");
2690 }
2691 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2692 if (TREE_CODE_CLASS (code) == tcc_comparison
2693 && (TREE_CODE_CLASS (code1) == tcc_comparison
2694 || TREE_CODE_CLASS (code2) == tcc_comparison))
2695 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
2696 "have their mathematical meaning");
2697
2698 }
2699
2700 /* Warn about comparisons against string literals, with the exception
2701 of testing for equality or inequality of a string literal with NULL. */
2702 if (code == EQ_EXPR || code == NE_EXPR)
2703 {
2704 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2705 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2706 warning (OPT_Wstring_literal_comparison,
2707 "comparison with string literal");
2708 }
2709 else if (TREE_CODE_CLASS (code) == tcc_comparison
2710 && (code1 == STRING_CST || code2 == STRING_CST))
2711 warning (OPT_Wstring_literal_comparison,
2712 "comparison with string literal");
2713
2714 overflow_warning (result.value);
2715
2716 return result;
2717 }
2718 \f
2719 /* Return a tree for the difference of pointers OP0 and OP1.
2720 The resulting tree has type int. */
2721
2722 static tree
2723 pointer_diff (tree op0, tree op1)
2724 {
2725 tree restype = ptrdiff_type_node;
2726
2727 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2728 tree con0, con1, lit0, lit1;
2729 tree orig_op1 = op1;
2730
2731 if (pedantic || warn_pointer_arith)
2732 {
2733 if (TREE_CODE (target_type) == VOID_TYPE)
2734 pedwarn ("pointer of type %<void *%> used in subtraction");
2735 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2736 pedwarn ("pointer to a function used in subtraction");
2737 }
2738
2739 /* If the conversion to ptrdiff_type does anything like widening or
2740 converting a partial to an integral mode, we get a convert_expression
2741 that is in the way to do any simplifications.
2742 (fold-const.c doesn't know that the extra bits won't be needed.
2743 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2744 different mode in place.)
2745 So first try to find a common term here 'by hand'; we want to cover
2746 at least the cases that occur in legal static initializers. */
2747 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR)
2748 && (TYPE_PRECISION (TREE_TYPE (op0))
2749 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2750 con0 = TREE_OPERAND (op0, 0);
2751 else
2752 con0 = op0;
2753 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR)
2754 && (TYPE_PRECISION (TREE_TYPE (op1))
2755 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2756 con1 = TREE_OPERAND (op1, 0);
2757 else
2758 con1 = op1;
2759
2760 if (TREE_CODE (con0) == PLUS_EXPR)
2761 {
2762 lit0 = TREE_OPERAND (con0, 1);
2763 con0 = TREE_OPERAND (con0, 0);
2764 }
2765 else
2766 lit0 = integer_zero_node;
2767
2768 if (TREE_CODE (con1) == PLUS_EXPR)
2769 {
2770 lit1 = TREE_OPERAND (con1, 1);
2771 con1 = TREE_OPERAND (con1, 0);
2772 }
2773 else
2774 lit1 = integer_zero_node;
2775
2776 if (operand_equal_p (con0, con1, 0))
2777 {
2778 op0 = lit0;
2779 op1 = lit1;
2780 }
2781
2782
2783 /* First do the subtraction as integers;
2784 then drop through to build the divide operator.
2785 Do not do default conversions on the minus operator
2786 in case restype is a short type. */
2787
2788 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2789 convert (restype, op1), 0);
2790 /* This generates an error if op1 is pointer to incomplete type. */
2791 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2792 error ("arithmetic on pointer to an incomplete type");
2793
2794 /* This generates an error if op0 is pointer to incomplete type. */
2795 op1 = c_size_in_bytes (target_type);
2796
2797 /* Divide by the size, in easiest possible way. */
2798 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2799 }
2800 \f
2801 /* Construct and perhaps optimize a tree representation
2802 for a unary operation. CODE, a tree_code, specifies the operation
2803 and XARG is the operand.
2804 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2805 the default promotions (such as from short to int).
2806 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2807 allows non-lvalues; this is only used to handle conversion of non-lvalue
2808 arrays to pointers in C99. */
2809
2810 tree
2811 build_unary_op (enum tree_code code, tree xarg, int flag)
2812 {
2813 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2814 tree arg = xarg;
2815 tree argtype = 0;
2816 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2817 tree val;
2818 int noconvert = flag;
2819 const char *invalid_op_diag;
2820
2821 if (typecode == ERROR_MARK)
2822 return error_mark_node;
2823 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2824 typecode = INTEGER_TYPE;
2825
2826 if ((invalid_op_diag
2827 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2828 {
2829 error (invalid_op_diag);
2830 return error_mark_node;
2831 }
2832
2833 switch (code)
2834 {
2835 case CONVERT_EXPR:
2836 /* This is used for unary plus, because a CONVERT_EXPR
2837 is enough to prevent anybody from looking inside for
2838 associativity, but won't generate any code. */
2839 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2840 || typecode == COMPLEX_TYPE
2841 || typecode == VECTOR_TYPE))
2842 {
2843 error ("wrong type argument to unary plus");
2844 return error_mark_node;
2845 }
2846 else if (!noconvert)
2847 arg = default_conversion (arg);
2848 arg = non_lvalue (arg);
2849 break;
2850
2851 case NEGATE_EXPR:
2852 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2853 || typecode == COMPLEX_TYPE
2854 || typecode == VECTOR_TYPE))
2855 {
2856 error ("wrong type argument to unary minus");
2857 return error_mark_node;
2858 }
2859 else if (!noconvert)
2860 arg = default_conversion (arg);
2861 break;
2862
2863 case BIT_NOT_EXPR:
2864 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE)
2865 {
2866 if (!noconvert)
2867 arg = default_conversion (arg);
2868 }
2869 else if (typecode == COMPLEX_TYPE)
2870 {
2871 code = CONJ_EXPR;
2872 if (pedantic)
2873 pedwarn ("ISO C does not support %<~%> for complex conjugation");
2874 if (!noconvert)
2875 arg = default_conversion (arg);
2876 }
2877 else
2878 {
2879 error ("wrong type argument to bit-complement");
2880 return error_mark_node;
2881 }
2882 break;
2883
2884 case ABS_EXPR:
2885 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2886 {
2887 error ("wrong type argument to abs");
2888 return error_mark_node;
2889 }
2890 else if (!noconvert)
2891 arg = default_conversion (arg);
2892 break;
2893
2894 case CONJ_EXPR:
2895 /* Conjugating a real value is a no-op, but allow it anyway. */
2896 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2897 || typecode == COMPLEX_TYPE))
2898 {
2899 error ("wrong type argument to conjugation");
2900 return error_mark_node;
2901 }
2902 else if (!noconvert)
2903 arg = default_conversion (arg);
2904 break;
2905
2906 case TRUTH_NOT_EXPR:
2907 if (typecode != INTEGER_TYPE
2908 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2909 && typecode != COMPLEX_TYPE)
2910 {
2911 error ("wrong type argument to unary exclamation mark");
2912 return error_mark_node;
2913 }
2914 arg = c_objc_common_truthvalue_conversion (arg);
2915 return invert_truthvalue (arg);
2916
2917 case REALPART_EXPR:
2918 if (TREE_CODE (arg) == COMPLEX_CST)
2919 return TREE_REALPART (arg);
2920 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2921 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2922 else
2923 return arg;
2924
2925 case IMAGPART_EXPR:
2926 if (TREE_CODE (arg) == COMPLEX_CST)
2927 return TREE_IMAGPART (arg);
2928 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2929 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2930 else
2931 return convert (TREE_TYPE (arg), integer_zero_node);
2932
2933 case PREINCREMENT_EXPR:
2934 case POSTINCREMENT_EXPR:
2935 case PREDECREMENT_EXPR:
2936 case POSTDECREMENT_EXPR:
2937
2938 /* Increment or decrement the real part of the value,
2939 and don't change the imaginary part. */
2940 if (typecode == COMPLEX_TYPE)
2941 {
2942 tree real, imag;
2943
2944 if (pedantic)
2945 pedwarn ("ISO C does not support %<++%> and %<--%>"
2946 " on complex types");
2947
2948 arg = stabilize_reference (arg);
2949 real = build_unary_op (REALPART_EXPR, arg, 1);
2950 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2951 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
2952 build_unary_op (code, real, 1), imag);
2953 }
2954
2955 /* Report invalid types. */
2956
2957 if (typecode != POINTER_TYPE
2958 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2959 {
2960 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2961 error ("wrong type argument to increment");
2962 else
2963 error ("wrong type argument to decrement");
2964
2965 return error_mark_node;
2966 }
2967
2968 {
2969 tree inc;
2970 tree result_type = TREE_TYPE (arg);
2971
2972 arg = get_unwidened (arg, 0);
2973 argtype = TREE_TYPE (arg);
2974
2975 /* Compute the increment. */
2976
2977 if (typecode == POINTER_TYPE)
2978 {
2979 /* If pointer target is an undefined struct,
2980 we just cannot know how to do the arithmetic. */
2981 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2982 {
2983 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2984 error ("increment of pointer to unknown structure");
2985 else
2986 error ("decrement of pointer to unknown structure");
2987 }
2988 else if ((pedantic || warn_pointer_arith)
2989 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2990 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2991 {
2992 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2993 pedwarn ("wrong type argument to increment");
2994 else
2995 pedwarn ("wrong type argument to decrement");
2996 }
2997
2998 inc = c_size_in_bytes (TREE_TYPE (result_type));
2999 }
3000 else
3001 inc = integer_one_node;
3002
3003 inc = convert (argtype, inc);
3004
3005 /* Complain about anything else that is not a true lvalue. */
3006 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3007 || code == POSTINCREMENT_EXPR)
3008 ? lv_increment
3009 : lv_decrement)))
3010 return error_mark_node;
3011
3012 /* Report a read-only lvalue. */
3013 if (TREE_READONLY (arg))
3014 {
3015 readonly_error (arg,
3016 ((code == PREINCREMENT_EXPR
3017 || code == POSTINCREMENT_EXPR)
3018 ? lv_increment : lv_decrement));
3019 return error_mark_node;
3020 }
3021
3022 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3023 val = boolean_increment (code, arg);
3024 else
3025 val = build2 (code, TREE_TYPE (arg), arg, inc);
3026 TREE_SIDE_EFFECTS (val) = 1;
3027 val = convert (result_type, val);
3028 if (TREE_CODE (val) != code)
3029 TREE_NO_WARNING (val) = 1;
3030 return val;
3031 }
3032
3033 case ADDR_EXPR:
3034 /* Note that this operation never does default_conversion. */
3035
3036 /* Let &* cancel out to simplify resulting code. */
3037 if (TREE_CODE (arg) == INDIRECT_REF)
3038 {
3039 /* Don't let this be an lvalue. */
3040 if (lvalue_p (TREE_OPERAND (arg, 0)))
3041 return non_lvalue (TREE_OPERAND (arg, 0));
3042 return TREE_OPERAND (arg, 0);
3043 }
3044
3045 /* For &x[y], return x+y */
3046 if (TREE_CODE (arg) == ARRAY_REF)
3047 {
3048 tree op0 = TREE_OPERAND (arg, 0);
3049 if (!c_mark_addressable (op0))
3050 return error_mark_node;
3051 return build_binary_op (PLUS_EXPR,
3052 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
3053 ? array_to_pointer_conversion (op0)
3054 : op0),
3055 TREE_OPERAND (arg, 1), 1);
3056 }
3057
3058 /* Anything not already handled and not a true memory reference
3059 or a non-lvalue array is an error. */
3060 else if (typecode != FUNCTION_TYPE && !flag
3061 && !lvalue_or_else (arg, lv_addressof))
3062 return error_mark_node;
3063
3064 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3065 argtype = TREE_TYPE (arg);
3066
3067 /* If the lvalue is const or volatile, merge that into the type
3068 to which the address will point. Note that you can't get a
3069 restricted pointer by taking the address of something, so we
3070 only have to deal with `const' and `volatile' here. */
3071 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3072 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3073 argtype = c_build_type_variant (argtype,
3074 TREE_READONLY (arg),
3075 TREE_THIS_VOLATILE (arg));
3076
3077 if (!c_mark_addressable (arg))
3078 return error_mark_node;
3079
3080 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3081 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3082
3083 argtype = build_pointer_type (argtype);
3084
3085 /* ??? Cope with user tricks that amount to offsetof. Delete this
3086 when we have proper support for integer constant expressions. */
3087 val = get_base_address (arg);
3088 if (val && TREE_CODE (val) == INDIRECT_REF
3089 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3090 {
3091 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1;
3092
3093 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3094 return fold_build2 (PLUS_EXPR, argtype, op0, op1);
3095 }
3096
3097 val = build1 (ADDR_EXPR, argtype, arg);
3098
3099 return val;
3100
3101 default:
3102 gcc_unreachable ();
3103 }
3104
3105 if (argtype == 0)
3106 argtype = TREE_TYPE (arg);
3107 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3108 : fold_build1 (code, argtype, arg);
3109 }
3110
3111 /* Return nonzero if REF is an lvalue valid for this language.
3112 Lvalues can be assigned, unless their type has TYPE_READONLY.
3113 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3114
3115 static int
3116 lvalue_p (tree ref)
3117 {
3118 enum tree_code code = TREE_CODE (ref);
3119
3120 switch (code)
3121 {
3122 case REALPART_EXPR:
3123 case IMAGPART_EXPR:
3124 case COMPONENT_REF:
3125 return lvalue_p (TREE_OPERAND (ref, 0));
3126
3127 case COMPOUND_LITERAL_EXPR:
3128 case STRING_CST:
3129 return 1;
3130
3131 case INDIRECT_REF:
3132 case ARRAY_REF:
3133 case VAR_DECL:
3134 case PARM_DECL:
3135 case RESULT_DECL:
3136 case ERROR_MARK:
3137 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3138 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3139
3140 case BIND_EXPR:
3141 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3142
3143 default:
3144 return 0;
3145 }
3146 }
3147 \f
3148 /* Give an error for storing in something that is 'const'. */
3149
3150 static void
3151 readonly_error (tree arg, enum lvalue_use use)
3152 {
3153 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3154 || use == lv_asm);
3155 /* Using this macro rather than (for example) arrays of messages
3156 ensures that all the format strings are checked at compile
3157 time. */
3158 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3159 : (use == lv_increment ? (I) \
3160 : (use == lv_decrement ? (D) : (AS))))
3161 if (TREE_CODE (arg) == COMPONENT_REF)
3162 {
3163 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3164 readonly_error (TREE_OPERAND (arg, 0), use);
3165 else
3166 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3167 G_("increment of read-only member %qD"),
3168 G_("decrement of read-only member %qD"),
3169 G_("read-only member %qD used as %<asm%> output")),
3170 TREE_OPERAND (arg, 1));
3171 }
3172 else if (TREE_CODE (arg) == VAR_DECL)
3173 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3174 G_("increment of read-only variable %qD"),
3175 G_("decrement of read-only variable %qD"),
3176 G_("read-only variable %qD used as %<asm%> output")),
3177 arg);
3178 else
3179 error (READONLY_MSG (G_("assignment of read-only location"),
3180 G_("increment of read-only location"),
3181 G_("decrement of read-only location"),
3182 G_("read-only location used as %<asm%> output")));
3183 }
3184
3185
3186 /* Return nonzero if REF is an lvalue valid for this language;
3187 otherwise, print an error message and return zero. USE says
3188 how the lvalue is being used and so selects the error message. */
3189
3190 static int
3191 lvalue_or_else (tree ref, enum lvalue_use use)
3192 {
3193 int win = lvalue_p (ref);
3194
3195 if (!win)
3196 lvalue_error (use);
3197
3198 return win;
3199 }
3200 \f
3201 /* Mark EXP saying that we need to be able to take the
3202 address of it; it should not be allocated in a register.
3203 Returns true if successful. */
3204
3205 bool
3206 c_mark_addressable (tree exp)
3207 {
3208 tree x = exp;
3209
3210 while (1)
3211 switch (TREE_CODE (x))
3212 {
3213 case COMPONENT_REF:
3214 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3215 {
3216 error
3217 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3218 return false;
3219 }
3220
3221 /* ... fall through ... */
3222
3223 case ADDR_EXPR:
3224 case ARRAY_REF:
3225 case REALPART_EXPR:
3226 case IMAGPART_EXPR:
3227 x = TREE_OPERAND (x, 0);
3228 break;
3229
3230 case COMPOUND_LITERAL_EXPR:
3231 case CONSTRUCTOR:
3232 TREE_ADDRESSABLE (x) = 1;
3233 return true;
3234
3235 case VAR_DECL:
3236 case CONST_DECL:
3237 case PARM_DECL:
3238 case RESULT_DECL:
3239 if (C_DECL_REGISTER (x)
3240 && DECL_NONLOCAL (x))
3241 {
3242 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3243 {
3244 error
3245 ("global register variable %qD used in nested function", x);
3246 return false;
3247 }
3248 pedwarn ("register variable %qD used in nested function", x);
3249 }
3250 else if (C_DECL_REGISTER (x))
3251 {
3252 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3253 error ("address of global register variable %qD requested", x);
3254 else
3255 error ("address of register variable %qD requested", x);
3256 return false;
3257 }
3258
3259 /* drops in */
3260 case FUNCTION_DECL:
3261 TREE_ADDRESSABLE (x) = 1;
3262 /* drops out */
3263 default:
3264 return true;
3265 }
3266 }
3267 \f
3268 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3269
3270 tree
3271 build_conditional_expr (tree ifexp, tree op1, tree op2)
3272 {
3273 tree type1;
3274 tree type2;
3275 enum tree_code code1;
3276 enum tree_code code2;
3277 tree result_type = NULL;
3278 tree orig_op1 = op1, orig_op2 = op2;
3279
3280 /* Promote both alternatives. */
3281
3282 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3283 op1 = default_conversion (op1);
3284 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3285 op2 = default_conversion (op2);
3286
3287 if (TREE_CODE (ifexp) == ERROR_MARK
3288 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3289 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3290 return error_mark_node;
3291
3292 type1 = TREE_TYPE (op1);
3293 code1 = TREE_CODE (type1);
3294 type2 = TREE_TYPE (op2);
3295 code2 = TREE_CODE (type2);
3296
3297 /* C90 does not permit non-lvalue arrays in conditional expressions.
3298 In C99 they will be pointers by now. */
3299 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3300 {
3301 error ("non-lvalue array in conditional expression");
3302 return error_mark_node;
3303 }
3304
3305 /* Quickly detect the usual case where op1 and op2 have the same type
3306 after promotion. */
3307 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3308 {
3309 if (type1 == type2)
3310 result_type = type1;
3311 else
3312 result_type = TYPE_MAIN_VARIANT (type1);
3313 }
3314 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3315 || code1 == COMPLEX_TYPE)
3316 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3317 || code2 == COMPLEX_TYPE))
3318 {
3319 result_type = c_common_type (type1, type2);
3320
3321 /* If -Wsign-compare, warn here if type1 and type2 have
3322 different signedness. We'll promote the signed to unsigned
3323 and later code won't know it used to be different.
3324 Do this check on the original types, so that explicit casts
3325 will be considered, but default promotions won't. */
3326 if (warn_sign_compare && !skip_evaluation)
3327 {
3328 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3329 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3330
3331 if (unsigned_op1 ^ unsigned_op2)
3332 {
3333 /* Do not warn if the result type is signed, since the
3334 signed type will only be chosen if it can represent
3335 all the values of the unsigned type. */
3336 if (!TYPE_UNSIGNED (result_type))
3337 /* OK */;
3338 /* Do not warn if the signed quantity is an unsuffixed
3339 integer literal (or some static constant expression
3340 involving such literals) and it is non-negative. */
3341 else if ((unsigned_op2 && tree_expr_nonnegative_p (op1))
3342 || (unsigned_op1 && tree_expr_nonnegative_p (op2)))
3343 /* OK */;
3344 else
3345 warning (0, "signed and unsigned type in conditional expression");
3346 }
3347 }
3348 }
3349 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3350 {
3351 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3352 pedwarn ("ISO C forbids conditional expr with only one void side");
3353 result_type = void_type_node;
3354 }
3355 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3356 {
3357 if (comp_target_types (type1, type2))
3358 result_type = common_pointer_type (type1, type2);
3359 else if (null_pointer_constant_p (orig_op1))
3360 result_type = qualify_type (type2, type1);
3361 else if (null_pointer_constant_p (orig_op2))
3362 result_type = qualify_type (type1, type2);
3363 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3364 {
3365 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3366 pedwarn ("ISO C forbids conditional expr between "
3367 "%<void *%> and function pointer");
3368 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3369 TREE_TYPE (type2)));
3370 }
3371 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3372 {
3373 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3374 pedwarn ("ISO C forbids conditional expr between "
3375 "%<void *%> and function pointer");
3376 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3377 TREE_TYPE (type1)));
3378 }
3379 else
3380 {
3381 pedwarn ("pointer type mismatch in conditional expression");
3382 result_type = build_pointer_type (void_type_node);
3383 }
3384 }
3385 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3386 {
3387 if (!null_pointer_constant_p (orig_op2))
3388 pedwarn ("pointer/integer type mismatch in conditional expression");
3389 else
3390 {
3391 op2 = null_pointer_node;
3392 }
3393 result_type = type1;
3394 }
3395 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3396 {
3397 if (!null_pointer_constant_p (orig_op1))
3398 pedwarn ("pointer/integer type mismatch in conditional expression");
3399 else
3400 {
3401 op1 = null_pointer_node;
3402 }
3403 result_type = type2;
3404 }
3405
3406 if (!result_type)
3407 {
3408 if (flag_cond_mismatch)
3409 result_type = void_type_node;
3410 else
3411 {
3412 error ("type mismatch in conditional expression");
3413 return error_mark_node;
3414 }
3415 }
3416
3417 /* Merge const and volatile flags of the incoming types. */
3418 result_type
3419 = build_type_variant (result_type,
3420 TREE_READONLY (op1) || TREE_READONLY (op2),
3421 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3422
3423 if (result_type != TREE_TYPE (op1))
3424 op1 = convert_and_check (result_type, op1);
3425 if (result_type != TREE_TYPE (op2))
3426 op2 = convert_and_check (result_type, op2);
3427
3428 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3429 }
3430 \f
3431 /* Return a compound expression that performs two expressions and
3432 returns the value of the second of them. */
3433
3434 tree
3435 build_compound_expr (tree expr1, tree expr2)
3436 {
3437 if (!TREE_SIDE_EFFECTS (expr1))
3438 {
3439 /* The left-hand operand of a comma expression is like an expression
3440 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3441 any side-effects, unless it was explicitly cast to (void). */
3442 if (warn_unused_value)
3443 {
3444 if (VOID_TYPE_P (TREE_TYPE (expr1))
3445 && (TREE_CODE (expr1) == NOP_EXPR
3446 || TREE_CODE (expr1) == CONVERT_EXPR))
3447 ; /* (void) a, b */
3448 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3449 && TREE_CODE (expr1) == COMPOUND_EXPR
3450 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR
3451 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR))
3452 ; /* (void) a, (void) b, c */
3453 else
3454 warning (0, "left-hand operand of comma expression has no effect");
3455 }
3456 }
3457
3458 /* With -Wunused, we should also warn if the left-hand operand does have
3459 side-effects, but computes a value which is not used. For example, in
3460 `foo() + bar(), baz()' the result of the `+' operator is not used,
3461 so we should issue a warning. */
3462 else if (warn_unused_value)
3463 warn_if_unused_value (expr1, input_location);
3464
3465 if (expr2 == error_mark_node)
3466 return error_mark_node;
3467
3468 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3469 }
3470
3471 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3472
3473 tree
3474 build_c_cast (tree type, tree expr)
3475 {
3476 tree value = expr;
3477
3478 if (type == error_mark_node || expr == error_mark_node)
3479 return error_mark_node;
3480
3481 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3482 only in <protocol> qualifications. But when constructing cast expressions,
3483 the protocols do matter and must be kept around. */
3484 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3485 return build1 (NOP_EXPR, type, expr);
3486
3487 type = TYPE_MAIN_VARIANT (type);
3488
3489 if (TREE_CODE (type) == ARRAY_TYPE)
3490 {
3491 error ("cast specifies array type");
3492 return error_mark_node;
3493 }
3494
3495 if (TREE_CODE (type) == FUNCTION_TYPE)
3496 {
3497 error ("cast specifies function type");
3498 return error_mark_node;
3499 }
3500
3501 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3502 {
3503 if (pedantic)
3504 {
3505 if (TREE_CODE (type) == RECORD_TYPE
3506 || TREE_CODE (type) == UNION_TYPE)
3507 pedwarn ("ISO C forbids casting nonscalar to the same type");
3508 }
3509 }
3510 else if (TREE_CODE (type) == UNION_TYPE)
3511 {
3512 tree field;
3513
3514 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3515 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3516 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3517 break;
3518
3519 if (field)
3520 {
3521 tree t;
3522
3523 if (pedantic)
3524 pedwarn ("ISO C forbids casts to union type");
3525 t = digest_init (type,
3526 build_constructor_single (type, field, value),
3527 true, 0);
3528 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3529 TREE_INVARIANT (t) = TREE_INVARIANT (value);
3530 return t;
3531 }
3532 error ("cast to union type from type not present in union");
3533 return error_mark_node;
3534 }
3535 else
3536 {
3537 tree otype, ovalue;
3538
3539 if (type == void_type_node)
3540 return build1 (CONVERT_EXPR, type, value);
3541
3542 otype = TREE_TYPE (value);
3543
3544 /* Optionally warn about potentially worrisome casts. */
3545
3546 if (warn_cast_qual
3547 && TREE_CODE (type) == POINTER_TYPE
3548 && TREE_CODE (otype) == POINTER_TYPE)
3549 {
3550 tree in_type = type;
3551 tree in_otype = otype;
3552 int added = 0;
3553 int discarded = 0;
3554
3555 /* Check that the qualifiers on IN_TYPE are a superset of
3556 the qualifiers of IN_OTYPE. The outermost level of
3557 POINTER_TYPE nodes is uninteresting and we stop as soon
3558 as we hit a non-POINTER_TYPE node on either type. */
3559 do
3560 {
3561 in_otype = TREE_TYPE (in_otype);
3562 in_type = TREE_TYPE (in_type);
3563
3564 /* GNU C allows cv-qualified function types. 'const'
3565 means the function is very pure, 'volatile' means it
3566 can't return. We need to warn when such qualifiers
3567 are added, not when they're taken away. */
3568 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3569 && TREE_CODE (in_type) == FUNCTION_TYPE)
3570 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3571 else
3572 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3573 }
3574 while (TREE_CODE (in_type) == POINTER_TYPE
3575 && TREE_CODE (in_otype) == POINTER_TYPE);
3576
3577 if (added)
3578 warning (0, "cast adds new qualifiers to function type");
3579
3580 if (discarded)
3581 /* There are qualifiers present in IN_OTYPE that are not
3582 present in IN_TYPE. */
3583 warning (0, "cast discards qualifiers from pointer target type");
3584 }
3585
3586 /* Warn about possible alignment problems. */
3587 if (STRICT_ALIGNMENT
3588 && TREE_CODE (type) == POINTER_TYPE
3589 && TREE_CODE (otype) == POINTER_TYPE
3590 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3591 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3592 /* Don't warn about opaque types, where the actual alignment
3593 restriction is unknown. */
3594 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3595 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3596 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3597 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3598 warning (OPT_Wcast_align,
3599 "cast increases required alignment of target type");
3600
3601 if (TREE_CODE (type) == INTEGER_TYPE
3602 && TREE_CODE (otype) == POINTER_TYPE
3603 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3604 /* Unlike conversion of integers to pointers, where the
3605 warning is disabled for converting constants because
3606 of cases such as SIG_*, warn about converting constant
3607 pointers to integers. In some cases it may cause unwanted
3608 sign extension, and a warning is appropriate. */
3609 warning (OPT_Wpointer_to_int_cast,
3610 "cast from pointer to integer of different size");
3611
3612 if (TREE_CODE (value) == CALL_EXPR
3613 && TREE_CODE (type) != TREE_CODE (otype))
3614 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3615 "to non-matching type %qT", otype, type);
3616
3617 if (TREE_CODE (type) == POINTER_TYPE
3618 && TREE_CODE (otype) == INTEGER_TYPE
3619 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3620 /* Don't warn about converting any constant. */
3621 && !TREE_CONSTANT (value))
3622 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3623 "of different size");
3624
3625 strict_aliasing_warning (otype, type, expr);
3626
3627 /* If pedantic, warn for conversions between function and object
3628 pointer types, except for converting a null pointer constant
3629 to function pointer type. */
3630 if (pedantic
3631 && TREE_CODE (type) == POINTER_TYPE
3632 && TREE_CODE (otype) == POINTER_TYPE
3633 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3634 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3635 pedwarn ("ISO C forbids conversion of function pointer to object pointer type");
3636
3637 if (pedantic
3638 && TREE_CODE (type) == POINTER_TYPE
3639 && TREE_CODE (otype) == POINTER_TYPE
3640 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3641 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3642 && !null_pointer_constant_p (value))
3643 pedwarn ("ISO C forbids conversion of object pointer to function pointer type");
3644
3645 ovalue = value;
3646 value = convert (type, value);
3647
3648 /* Ignore any integer overflow caused by the cast. */
3649 if (TREE_CODE (value) == INTEGER_CST)
3650 {
3651 if (CONSTANT_CLASS_P (ovalue)
3652 && (TREE_OVERFLOW (ovalue) || TREE_CONSTANT_OVERFLOW (ovalue)))
3653 {
3654 /* Avoid clobbering a shared constant. */
3655 value = copy_node (value);
3656 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3657 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
3658 }
3659 else if (TREE_OVERFLOW (value) || TREE_CONSTANT_OVERFLOW (value))
3660 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3661 value = build_int_cst_wide (TREE_TYPE (value),
3662 TREE_INT_CST_LOW (value),
3663 TREE_INT_CST_HIGH (value));
3664 }
3665 }
3666
3667 /* Don't let a cast be an lvalue. */
3668 if (value == expr)
3669 value = non_lvalue (value);
3670
3671 return value;
3672 }
3673
3674 /* Interpret a cast of expression EXPR to type TYPE. */
3675 tree
3676 c_cast_expr (struct c_type_name *type_name, tree expr)
3677 {
3678 tree type;
3679 int saved_wsp = warn_strict_prototypes;
3680
3681 /* This avoids warnings about unprototyped casts on
3682 integers. E.g. "#define SIG_DFL (void(*)())0". */
3683 if (TREE_CODE (expr) == INTEGER_CST)
3684 warn_strict_prototypes = 0;
3685 type = groktypename (type_name);
3686 warn_strict_prototypes = saved_wsp;
3687
3688 return build_c_cast (type, expr);
3689 }
3690 \f
3691 /* Build an assignment expression of lvalue LHS from value RHS.
3692 MODIFYCODE is the code for a binary operator that we use
3693 to combine the old value of LHS with RHS to get the new value.
3694 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3695
3696 tree
3697 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3698 {
3699 tree result;
3700 tree newrhs;
3701 tree lhstype = TREE_TYPE (lhs);
3702 tree olhstype = lhstype;
3703
3704 /* Types that aren't fully specified cannot be used in assignments. */
3705 lhs = require_complete_type (lhs);
3706
3707 /* Avoid duplicate error messages from operands that had errors. */
3708 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3709 return error_mark_node;
3710
3711 if (!lvalue_or_else (lhs, lv_assign))
3712 return error_mark_node;
3713
3714 STRIP_TYPE_NOPS (rhs);
3715
3716 newrhs = rhs;
3717
3718 /* If a binary op has been requested, combine the old LHS value with the RHS
3719 producing the value we should actually store into the LHS. */
3720
3721 if (modifycode != NOP_EXPR)
3722 {
3723 lhs = stabilize_reference (lhs);
3724 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3725 }
3726
3727 /* Give an error for storing in something that is 'const'. */
3728
3729 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3730 || ((TREE_CODE (lhstype) == RECORD_TYPE
3731 || TREE_CODE (lhstype) == UNION_TYPE)
3732 && C_TYPE_FIELDS_READONLY (lhstype)))
3733 {
3734 readonly_error (lhs, lv_assign);
3735 return error_mark_node;
3736 }
3737
3738 /* If storing into a structure or union member,
3739 it has probably been given type `int'.
3740 Compute the type that would go with
3741 the actual amount of storage the member occupies. */
3742
3743 if (TREE_CODE (lhs) == COMPONENT_REF
3744 && (TREE_CODE (lhstype) == INTEGER_TYPE
3745 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3746 || TREE_CODE (lhstype) == REAL_TYPE
3747 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3748 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3749
3750 /* If storing in a field that is in actuality a short or narrower than one,
3751 we must store in the field in its actual type. */
3752
3753 if (lhstype != TREE_TYPE (lhs))
3754 {
3755 lhs = copy_node (lhs);
3756 TREE_TYPE (lhs) = lhstype;
3757 }
3758
3759 /* Convert new value to destination type. */
3760
3761 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3762 NULL_TREE, NULL_TREE, 0);
3763 if (TREE_CODE (newrhs) == ERROR_MARK)
3764 return error_mark_node;
3765
3766 /* Emit ObjC write barrier, if necessary. */
3767 if (c_dialect_objc () && flag_objc_gc)
3768 {
3769 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3770 if (result)
3771 return result;
3772 }
3773
3774 /* Scan operands. */
3775
3776 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3777 TREE_SIDE_EFFECTS (result) = 1;
3778
3779 /* If we got the LHS in a different type for storing in,
3780 convert the result back to the nominal type of LHS
3781 so that the value we return always has the same type
3782 as the LHS argument. */
3783
3784 if (olhstype == TREE_TYPE (result))
3785 return result;
3786 return convert_for_assignment (olhstype, result, ic_assign,
3787 NULL_TREE, NULL_TREE, 0);
3788 }
3789 \f
3790 /* Convert value RHS to type TYPE as preparation for an assignment
3791 to an lvalue of type TYPE.
3792 The real work of conversion is done by `convert'.
3793 The purpose of this function is to generate error messages
3794 for assignments that are not allowed in C.
3795 ERRTYPE says whether it is argument passing, assignment,
3796 initialization or return.
3797
3798 FUNCTION is a tree for the function being called.
3799 PARMNUM is the number of the argument, for printing in error messages. */
3800
3801 static tree
3802 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3803 tree fundecl, tree function, int parmnum)
3804 {
3805 enum tree_code codel = TREE_CODE (type);
3806 tree rhstype;
3807 enum tree_code coder;
3808 tree rname = NULL_TREE;
3809 bool objc_ok = false;
3810
3811 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3812 {
3813 tree selector;
3814 /* Change pointer to function to the function itself for
3815 diagnostics. */
3816 if (TREE_CODE (function) == ADDR_EXPR
3817 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3818 function = TREE_OPERAND (function, 0);
3819
3820 /* Handle an ObjC selector specially for diagnostics. */
3821 selector = objc_message_selector ();
3822 rname = function;
3823 if (selector && parmnum > 2)
3824 {
3825 rname = selector;
3826 parmnum -= 2;
3827 }
3828 }
3829
3830 /* This macro is used to emit diagnostics to ensure that all format
3831 strings are complete sentences, visible to gettext and checked at
3832 compile time. */
3833 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3834 do { \
3835 switch (errtype) \
3836 { \
3837 case ic_argpass: \
3838 pedwarn (AR, parmnum, rname); \
3839 break; \
3840 case ic_argpass_nonproto: \
3841 warning (0, AR, parmnum, rname); \
3842 break; \
3843 case ic_assign: \
3844 pedwarn (AS); \
3845 break; \
3846 case ic_init: \
3847 pedwarn (IN); \
3848 break; \
3849 case ic_return: \
3850 pedwarn (RE); \
3851 break; \
3852 default: \
3853 gcc_unreachable (); \
3854 } \
3855 } while (0)
3856
3857 STRIP_TYPE_NOPS (rhs);
3858
3859 if (optimize && TREE_CODE (rhs) == VAR_DECL
3860 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
3861 rhs = decl_constant_value_for_broken_optimization (rhs);
3862
3863 rhstype = TREE_TYPE (rhs);
3864 coder = TREE_CODE (rhstype);
3865
3866 if (coder == ERROR_MARK)
3867 return error_mark_node;
3868
3869 if (c_dialect_objc ())
3870 {
3871 int parmno;
3872
3873 switch (errtype)
3874 {
3875 case ic_return:
3876 parmno = 0;
3877 break;
3878
3879 case ic_assign:
3880 parmno = -1;
3881 break;
3882
3883 case ic_init:
3884 parmno = -2;
3885 break;
3886
3887 default:
3888 parmno = parmnum;
3889 break;
3890 }
3891
3892 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
3893 }
3894
3895 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
3896 {
3897 overflow_warning (rhs);
3898 return rhs;
3899 }
3900
3901 if (coder == VOID_TYPE)
3902 {
3903 /* Except for passing an argument to an unprototyped function,
3904 this is a constraint violation. When passing an argument to
3905 an unprototyped function, it is compile-time undefined;
3906 making it a constraint in that case was rejected in
3907 DR#252. */
3908 error ("void value not ignored as it ought to be");
3909 return error_mark_node;
3910 }
3911 /* A type converts to a reference to it.
3912 This code doesn't fully support references, it's just for the
3913 special case of va_start and va_copy. */
3914 if (codel == REFERENCE_TYPE
3915 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
3916 {
3917 if (!lvalue_p (rhs))
3918 {
3919 error ("cannot pass rvalue to reference parameter");
3920 return error_mark_node;
3921 }
3922 if (!c_mark_addressable (rhs))
3923 return error_mark_node;
3924 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
3925
3926 /* We already know that these two types are compatible, but they
3927 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3928 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3929 likely to be va_list, a typedef to __builtin_va_list, which
3930 is different enough that it will cause problems later. */
3931 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
3932 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
3933
3934 rhs = build1 (NOP_EXPR, type, rhs);
3935 return rhs;
3936 }
3937 /* Some types can interconvert without explicit casts. */
3938 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
3939 && vector_types_convertible_p (type, TREE_TYPE (rhs)))
3940 return convert (type, rhs);
3941 /* Arithmetic types all interconvert, and enum is treated like int. */
3942 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
3943 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
3944 || codel == BOOLEAN_TYPE)
3945 && (coder == INTEGER_TYPE || coder == REAL_TYPE
3946 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
3947 || coder == BOOLEAN_TYPE))
3948 return convert_and_check (type, rhs);
3949
3950 /* Conversion to a transparent union from its member types.
3951 This applies only to function arguments. */
3952 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
3953 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
3954 {
3955 tree memb, marginal_memb = NULL_TREE;
3956
3957 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
3958 {
3959 tree memb_type = TREE_TYPE (memb);
3960
3961 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
3962 TYPE_MAIN_VARIANT (rhstype)))
3963 break;
3964
3965 if (TREE_CODE (memb_type) != POINTER_TYPE)
3966 continue;
3967
3968 if (coder == POINTER_TYPE)
3969 {
3970 tree ttl = TREE_TYPE (memb_type);
3971 tree ttr = TREE_TYPE (rhstype);
3972
3973 /* Any non-function converts to a [const][volatile] void *
3974 and vice versa; otherwise, targets must be the same.
3975 Meanwhile, the lhs target must have all the qualifiers of
3976 the rhs. */
3977 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
3978 || comp_target_types (memb_type, rhstype))
3979 {
3980 /* If this type won't generate any warnings, use it. */
3981 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
3982 || ((TREE_CODE (ttr) == FUNCTION_TYPE
3983 && TREE_CODE (ttl) == FUNCTION_TYPE)
3984 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3985 == TYPE_QUALS (ttr))
3986 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3987 == TYPE_QUALS (ttl))))
3988 break;
3989
3990 /* Keep looking for a better type, but remember this one. */
3991 if (!marginal_memb)
3992 marginal_memb = memb;
3993 }
3994 }
3995
3996 /* Can convert integer zero to any pointer type. */
3997 if (null_pointer_constant_p (rhs))
3998 {
3999 rhs = null_pointer_node;
4000 break;
4001 }
4002 }
4003
4004 if (memb || marginal_memb)
4005 {
4006 if (!memb)
4007 {
4008 /* We have only a marginally acceptable member type;
4009 it needs a warning. */
4010 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
4011 tree ttr = TREE_TYPE (rhstype);
4012
4013 /* Const and volatile mean something different for function
4014 types, so the usual warnings are not appropriate. */
4015 if (TREE_CODE (ttr) == FUNCTION_TYPE
4016 && TREE_CODE (ttl) == FUNCTION_TYPE)
4017 {
4018 /* Because const and volatile on functions are
4019 restrictions that say the function will not do
4020 certain things, it is okay to use a const or volatile
4021 function where an ordinary one is wanted, but not
4022 vice-versa. */
4023 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4024 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE "
4025 "makes qualified function "
4026 "pointer from unqualified"),
4027 G_("assignment makes qualified "
4028 "function pointer from "
4029 "unqualified"),
4030 G_("initialization makes qualified "
4031 "function pointer from "
4032 "unqualified"),
4033 G_("return makes qualified function "
4034 "pointer from unqualified"));
4035 }
4036 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4037 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4038 "qualifiers from pointer target type"),
4039 G_("assignment discards qualifiers "
4040 "from pointer target type"),
4041 G_("initialization discards qualifiers "
4042 "from pointer target type"),
4043 G_("return discards qualifiers from "
4044 "pointer target type"));
4045
4046 memb = marginal_memb;
4047 }
4048
4049 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl)))
4050 pedwarn ("ISO C prohibits argument conversion to union type");
4051
4052 return build_constructor_single (type, memb, rhs);
4053 }
4054 }
4055
4056 /* Conversions among pointers */
4057 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4058 && (coder == codel))
4059 {
4060 tree ttl = TREE_TYPE (type);
4061 tree ttr = TREE_TYPE (rhstype);
4062 tree mvl = ttl;
4063 tree mvr = ttr;
4064 bool is_opaque_pointer;
4065 int target_cmp = 0; /* Cache comp_target_types () result. */
4066
4067 if (TREE_CODE (mvl) != ARRAY_TYPE)
4068 mvl = TYPE_MAIN_VARIANT (mvl);
4069 if (TREE_CODE (mvr) != ARRAY_TYPE)
4070 mvr = TYPE_MAIN_VARIANT (mvr);
4071 /* Opaque pointers are treated like void pointers. */
4072 is_opaque_pointer = (targetm.vector_opaque_p (type)
4073 || targetm.vector_opaque_p (rhstype))
4074 && TREE_CODE (ttl) == VECTOR_TYPE
4075 && TREE_CODE (ttr) == VECTOR_TYPE;
4076
4077 /* C++ does not allow the implicit conversion void* -> T*. However,
4078 for the purpose of reducing the number of false positives, we
4079 tolerate the special case of
4080
4081 int *p = NULL;
4082
4083 where NULL is typically defined in C to be '(void *) 0'. */
4084 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4085 warning (OPT_Wc___compat, "request for implicit conversion from "
4086 "%qT to %qT not permitted in C++", rhstype, type);
4087
4088 /* Check if the right-hand side has a format attribute but the
4089 left-hand side doesn't. */
4090 if (warn_missing_format_attribute
4091 && check_missing_format_attribute (type, rhstype))
4092 {
4093 switch (errtype)
4094 {
4095 case ic_argpass:
4096 case ic_argpass_nonproto:
4097 warning (OPT_Wmissing_format_attribute,
4098 "argument %d of %qE might be "
4099 "a candidate for a format attribute",
4100 parmnum, rname);
4101 break;
4102 case ic_assign:
4103 warning (OPT_Wmissing_format_attribute,
4104 "assignment left-hand side might be "
4105 "a candidate for a format attribute");
4106 break;
4107 case ic_init:
4108 warning (OPT_Wmissing_format_attribute,
4109 "initialization left-hand side might be "
4110 "a candidate for a format attribute");
4111 break;
4112 case ic_return:
4113 warning (OPT_Wmissing_format_attribute,
4114 "return type might be "
4115 "a candidate for a format attribute");
4116 break;
4117 default:
4118 gcc_unreachable ();
4119 }
4120 }
4121
4122 /* Any non-function converts to a [const][volatile] void *
4123 and vice versa; otherwise, targets must be the same.
4124 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4125 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4126 || (target_cmp = comp_target_types (type, rhstype))
4127 || is_opaque_pointer
4128 || (c_common_unsigned_type (mvl)
4129 == c_common_unsigned_type (mvr)))
4130 {
4131 if (pedantic
4132 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4133 ||
4134 (VOID_TYPE_P (ttr)
4135 && !null_pointer_constant_p (rhs)
4136 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4137 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of "
4138 "%qE between function pointer "
4139 "and %<void *%>"),
4140 G_("ISO C forbids assignment between "
4141 "function pointer and %<void *%>"),
4142 G_("ISO C forbids initialization between "
4143 "function pointer and %<void *%>"),
4144 G_("ISO C forbids return between function "
4145 "pointer and %<void *%>"));
4146 /* Const and volatile mean something different for function types,
4147 so the usual warnings are not appropriate. */
4148 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4149 && TREE_CODE (ttl) != FUNCTION_TYPE)
4150 {
4151 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4152 {
4153 /* Types differing only by the presence of the 'volatile'
4154 qualifier are acceptable if the 'volatile' has been added
4155 in by the Objective-C EH machinery. */
4156 if (!objc_type_quals_match (ttl, ttr))
4157 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4158 "qualifiers from pointer target type"),
4159 G_("assignment discards qualifiers "
4160 "from pointer target type"),
4161 G_("initialization discards qualifiers "
4162 "from pointer target type"),
4163 G_("return discards qualifiers from "
4164 "pointer target type"));
4165 }
4166 /* If this is not a case of ignoring a mismatch in signedness,
4167 no warning. */
4168 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4169 || target_cmp)
4170 ;
4171 /* If there is a mismatch, do warn. */
4172 else if (warn_pointer_sign)
4173 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument "
4174 "%d of %qE differ in signedness"),
4175 G_("pointer targets in assignment "
4176 "differ in signedness"),
4177 G_("pointer targets in initialization "
4178 "differ in signedness"),
4179 G_("pointer targets in return differ "
4180 "in signedness"));
4181 }
4182 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4183 && TREE_CODE (ttr) == FUNCTION_TYPE)
4184 {
4185 /* Because const and volatile on functions are restrictions
4186 that say the function will not do certain things,
4187 it is okay to use a const or volatile function
4188 where an ordinary one is wanted, but not vice-versa. */
4189 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4190 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4191 "qualified function pointer "
4192 "from unqualified"),
4193 G_("assignment makes qualified function "
4194 "pointer from unqualified"),
4195 G_("initialization makes qualified "
4196 "function pointer from unqualified"),
4197 G_("return makes qualified function "
4198 "pointer from unqualified"));
4199 }
4200 }
4201 else
4202 /* Avoid warning about the volatile ObjC EH puts on decls. */
4203 if (!objc_ok)
4204 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from "
4205 "incompatible pointer type"),
4206 G_("assignment from incompatible pointer type"),
4207 G_("initialization from incompatible "
4208 "pointer type"),
4209 G_("return from incompatible pointer type"));
4210
4211 return convert (type, rhs);
4212 }
4213 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4214 {
4215 /* ??? This should not be an error when inlining calls to
4216 unprototyped functions. */
4217 error ("invalid use of non-lvalue array");
4218 return error_mark_node;
4219 }
4220 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4221 {
4222 /* An explicit constant 0 can convert to a pointer,
4223 or one that results from arithmetic, even including
4224 a cast to integer type. */
4225 if (!null_pointer_constant_p (rhs))
4226 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4227 "pointer from integer without a cast"),
4228 G_("assignment makes pointer from integer "
4229 "without a cast"),
4230 G_("initialization makes pointer from "
4231 "integer without a cast"),
4232 G_("return makes pointer from integer "
4233 "without a cast"));
4234
4235 return convert (type, rhs);
4236 }
4237 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4238 {
4239 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer "
4240 "from pointer without a cast"),
4241 G_("assignment makes integer from pointer "
4242 "without a cast"),
4243 G_("initialization makes integer from pointer "
4244 "without a cast"),
4245 G_("return makes integer from pointer "
4246 "without a cast"));
4247 return convert (type, rhs);
4248 }
4249 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4250 return convert (type, rhs);
4251
4252 switch (errtype)
4253 {
4254 case ic_argpass:
4255 case ic_argpass_nonproto:
4256 /* ??? This should not be an error when inlining calls to
4257 unprototyped functions. */
4258 error ("incompatible type for argument %d of %qE", parmnum, rname);
4259 break;
4260 case ic_assign:
4261 error ("incompatible types in assignment");
4262 break;
4263 case ic_init:
4264 error ("incompatible types in initialization");
4265 break;
4266 case ic_return:
4267 error ("incompatible types in return");
4268 break;
4269 default:
4270 gcc_unreachable ();
4271 }
4272
4273 return error_mark_node;
4274 }
4275
4276 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
4277 is used for error and warning reporting and indicates which argument
4278 is being processed. */
4279
4280 tree
4281 c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum)
4282 {
4283 tree ret, type;
4284
4285 /* If FN was prototyped at the call site, the value has been converted
4286 already in convert_arguments.
4287 However, we might see a prototype now that was not in place when
4288 the function call was seen, so check that the VALUE actually matches
4289 PARM before taking an early exit. */
4290 if (!value
4291 || (TYPE_ARG_TYPES (TREE_TYPE (fn))
4292 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
4293 == TYPE_MAIN_VARIANT (TREE_TYPE (value)))))
4294 return value;
4295
4296 type = TREE_TYPE (parm);
4297 ret = convert_for_assignment (type, value,
4298 ic_argpass_nonproto, fn,
4299 fn, argnum);
4300 if (targetm.calls.promote_prototypes (TREE_TYPE (fn))
4301 && INTEGRAL_TYPE_P (type)
4302 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
4303 ret = default_conversion (ret);
4304 return ret;
4305 }
4306 \f
4307 /* If VALUE is a compound expr all of whose expressions are constant, then
4308 return its value. Otherwise, return error_mark_node.
4309
4310 This is for handling COMPOUND_EXPRs as initializer elements
4311 which is allowed with a warning when -pedantic is specified. */
4312
4313 static tree
4314 valid_compound_expr_initializer (tree value, tree endtype)
4315 {
4316 if (TREE_CODE (value) == COMPOUND_EXPR)
4317 {
4318 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4319 == error_mark_node)
4320 return error_mark_node;
4321 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4322 endtype);
4323 }
4324 else if (!initializer_constant_valid_p (value, endtype))
4325 return error_mark_node;
4326 else
4327 return value;
4328 }
4329 \f
4330 /* Perform appropriate conversions on the initial value of a variable,
4331 store it in the declaration DECL,
4332 and print any error messages that are appropriate.
4333 If the init is invalid, store an ERROR_MARK. */
4334
4335 void
4336 store_init_value (tree decl, tree init)
4337 {
4338 tree value, type;
4339
4340 /* If variable's type was invalidly declared, just ignore it. */
4341
4342 type = TREE_TYPE (decl);
4343 if (TREE_CODE (type) == ERROR_MARK)
4344 return;
4345
4346 /* Digest the specified initializer into an expression. */
4347
4348 value = digest_init (type, init, true, TREE_STATIC (decl));
4349
4350 /* Store the expression if valid; else report error. */
4351
4352 if (!in_system_header
4353 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4354 warning (OPT_Wtraditional, "traditional C rejects automatic "
4355 "aggregate initialization");
4356
4357 DECL_INITIAL (decl) = value;
4358
4359 /* ANSI wants warnings about out-of-range constant initializers. */
4360 STRIP_TYPE_NOPS (value);
4361 constant_expression_warning (value);
4362
4363 /* Check if we need to set array size from compound literal size. */
4364 if (TREE_CODE (type) == ARRAY_TYPE
4365 && TYPE_DOMAIN (type) == 0
4366 && value != error_mark_node)
4367 {
4368 tree inside_init = init;
4369
4370 STRIP_TYPE_NOPS (inside_init);
4371 inside_init = fold (inside_init);
4372
4373 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4374 {
4375 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4376
4377 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4378 {
4379 /* For int foo[] = (int [3]){1}; we need to set array size
4380 now since later on array initializer will be just the
4381 brace enclosed list of the compound literal. */
4382 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4383 TREE_TYPE (decl) = type;
4384 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4385 layout_type (type);
4386 layout_decl (cldecl, 0);
4387 }
4388 }
4389 }
4390 }
4391 \f
4392 /* Methods for storing and printing names for error messages. */
4393
4394 /* Implement a spelling stack that allows components of a name to be pushed
4395 and popped. Each element on the stack is this structure. */
4396
4397 struct spelling
4398 {
4399 int kind;
4400 union
4401 {
4402 unsigned HOST_WIDE_INT i;
4403 const char *s;
4404 } u;
4405 };
4406
4407 #define SPELLING_STRING 1
4408 #define SPELLING_MEMBER 2
4409 #define SPELLING_BOUNDS 3
4410
4411 static struct spelling *spelling; /* Next stack element (unused). */
4412 static struct spelling *spelling_base; /* Spelling stack base. */
4413 static int spelling_size; /* Size of the spelling stack. */
4414
4415 /* Macros to save and restore the spelling stack around push_... functions.
4416 Alternative to SAVE_SPELLING_STACK. */
4417
4418 #define SPELLING_DEPTH() (spelling - spelling_base)
4419 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4420
4421 /* Push an element on the spelling stack with type KIND and assign VALUE
4422 to MEMBER. */
4423
4424 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4425 { \
4426 int depth = SPELLING_DEPTH (); \
4427 \
4428 if (depth >= spelling_size) \
4429 { \
4430 spelling_size += 10; \
4431 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4432 spelling_size); \
4433 RESTORE_SPELLING_DEPTH (depth); \
4434 } \
4435 \
4436 spelling->kind = (KIND); \
4437 spelling->MEMBER = (VALUE); \
4438 spelling++; \
4439 }
4440
4441 /* Push STRING on the stack. Printed literally. */
4442
4443 static void
4444 push_string (const char *string)
4445 {
4446 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4447 }
4448
4449 /* Push a member name on the stack. Printed as '.' STRING. */
4450
4451 static void
4452 push_member_name (tree decl)
4453 {
4454 const char *const string
4455 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4456 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4457 }
4458
4459 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4460
4461 static void
4462 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4463 {
4464 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4465 }
4466
4467 /* Compute the maximum size in bytes of the printed spelling. */
4468
4469 static int
4470 spelling_length (void)
4471 {
4472 int size = 0;
4473 struct spelling *p;
4474
4475 for (p = spelling_base; p < spelling; p++)
4476 {
4477 if (p->kind == SPELLING_BOUNDS)
4478 size += 25;
4479 else
4480 size += strlen (p->u.s) + 1;
4481 }
4482
4483 return size;
4484 }
4485
4486 /* Print the spelling to BUFFER and return it. */
4487
4488 static char *
4489 print_spelling (char *buffer)
4490 {
4491 char *d = buffer;
4492 struct spelling *p;
4493
4494 for (p = spelling_base; p < spelling; p++)
4495 if (p->kind == SPELLING_BOUNDS)
4496 {
4497 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4498 d += strlen (d);
4499 }
4500 else
4501 {
4502 const char *s;
4503 if (p->kind == SPELLING_MEMBER)
4504 *d++ = '.';
4505 for (s = p->u.s; (*d = *s++); d++)
4506 ;
4507 }
4508 *d++ = '\0';
4509 return buffer;
4510 }
4511
4512 /* Issue an error message for a bad initializer component.
4513 MSGID identifies the message.
4514 The component name is taken from the spelling stack. */
4515
4516 void
4517 error_init (const char *msgid)
4518 {
4519 char *ofwhat;
4520
4521 error ("%s", _(msgid));
4522 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4523 if (*ofwhat)
4524 error ("(near initialization for %qs)", ofwhat);
4525 }
4526
4527 /* Issue a pedantic warning for a bad initializer component.
4528 MSGID identifies the message.
4529 The component name is taken from the spelling stack. */
4530
4531 void
4532 pedwarn_init (const char *msgid)
4533 {
4534 char *ofwhat;
4535
4536 pedwarn ("%s", _(msgid));
4537 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4538 if (*ofwhat)
4539 pedwarn ("(near initialization for %qs)", ofwhat);
4540 }
4541
4542 /* Issue a warning for a bad initializer component.
4543 MSGID identifies the message.
4544 The component name is taken from the spelling stack. */
4545
4546 static void
4547 warning_init (const char *msgid)
4548 {
4549 char *ofwhat;
4550
4551 warning (0, "%s", _(msgid));
4552 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4553 if (*ofwhat)
4554 warning (0, "(near initialization for %qs)", ofwhat);
4555 }
4556 \f
4557 /* If TYPE is an array type and EXPR is a parenthesized string
4558 constant, warn if pedantic that EXPR is being used to initialize an
4559 object of type TYPE. */
4560
4561 void
4562 maybe_warn_string_init (tree type, struct c_expr expr)
4563 {
4564 if (pedantic
4565 && TREE_CODE (type) == ARRAY_TYPE
4566 && TREE_CODE (expr.value) == STRING_CST
4567 && expr.original_code != STRING_CST)
4568 pedwarn_init ("array initialized from parenthesized string constant");
4569 }
4570
4571 /* Digest the parser output INIT as an initializer for type TYPE.
4572 Return a C expression of type TYPE to represent the initial value.
4573
4574 If INIT is a string constant, STRICT_STRING is true if it is
4575 unparenthesized or we should not warn here for it being parenthesized.
4576 For other types of INIT, STRICT_STRING is not used.
4577
4578 REQUIRE_CONSTANT requests an error if non-constant initializers or
4579 elements are seen. */
4580
4581 static tree
4582 digest_init (tree type, tree init, bool strict_string, int require_constant)
4583 {
4584 enum tree_code code = TREE_CODE (type);
4585 tree inside_init = init;
4586
4587 if (type == error_mark_node
4588 || !init
4589 || init == error_mark_node
4590 || TREE_TYPE (init) == error_mark_node)
4591 return error_mark_node;
4592
4593 STRIP_TYPE_NOPS (inside_init);
4594
4595 inside_init = fold (inside_init);
4596
4597 /* Initialization of an array of chars from a string constant
4598 optionally enclosed in braces. */
4599
4600 if (code == ARRAY_TYPE && inside_init
4601 && TREE_CODE (inside_init) == STRING_CST)
4602 {
4603 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4604 /* Note that an array could be both an array of character type
4605 and an array of wchar_t if wchar_t is signed char or unsigned
4606 char. */
4607 bool char_array = (typ1 == char_type_node
4608 || typ1 == signed_char_type_node
4609 || typ1 == unsigned_char_type_node);
4610 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4611 if (char_array || wchar_array)
4612 {
4613 struct c_expr expr;
4614 bool char_string;
4615 expr.value = inside_init;
4616 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4617 maybe_warn_string_init (type, expr);
4618
4619 char_string
4620 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4621 == char_type_node);
4622
4623 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4624 TYPE_MAIN_VARIANT (type)))
4625 return inside_init;
4626
4627 if (!wchar_array && !char_string)
4628 {
4629 error_init ("char-array initialized from wide string");
4630 return error_mark_node;
4631 }
4632 if (char_string && !char_array)
4633 {
4634 error_init ("wchar_t-array initialized from non-wide string");
4635 return error_mark_node;
4636 }
4637
4638 TREE_TYPE (inside_init) = type;
4639 if (TYPE_DOMAIN (type) != 0
4640 && TYPE_SIZE (type) != 0
4641 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4642 /* Subtract 1 (or sizeof (wchar_t))
4643 because it's ok to ignore the terminating null char
4644 that is counted in the length of the constant. */
4645 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4646 TREE_STRING_LENGTH (inside_init)
4647 - ((TYPE_PRECISION (typ1)
4648 != TYPE_PRECISION (char_type_node))
4649 ? (TYPE_PRECISION (wchar_type_node)
4650 / BITS_PER_UNIT)
4651 : 1)))
4652 pedwarn_init ("initializer-string for array of chars is too long");
4653
4654 return inside_init;
4655 }
4656 else if (INTEGRAL_TYPE_P (typ1))
4657 {
4658 error_init ("array of inappropriate type initialized "
4659 "from string constant");
4660 return error_mark_node;
4661 }
4662 }
4663
4664 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4665 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4666 below and handle as a constructor. */
4667 if (code == VECTOR_TYPE
4668 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4669 && vector_types_convertible_p (TREE_TYPE (inside_init), type)
4670 && TREE_CONSTANT (inside_init))
4671 {
4672 if (TREE_CODE (inside_init) == VECTOR_CST
4673 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4674 TYPE_MAIN_VARIANT (type)))
4675 return inside_init;
4676
4677 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4678 {
4679 unsigned HOST_WIDE_INT ix;
4680 tree value;
4681 bool constant_p = true;
4682
4683 /* Iterate through elements and check if all constructor
4684 elements are *_CSTs. */
4685 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4686 if (!CONSTANT_CLASS_P (value))
4687 {
4688 constant_p = false;
4689 break;
4690 }
4691
4692 if (constant_p)
4693 return build_vector_from_ctor (type,
4694 CONSTRUCTOR_ELTS (inside_init));
4695 }
4696 }
4697
4698 /* Any type can be initialized
4699 from an expression of the same type, optionally with braces. */
4700
4701 if (inside_init && TREE_TYPE (inside_init) != 0
4702 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4703 TYPE_MAIN_VARIANT (type))
4704 || (code == ARRAY_TYPE
4705 && comptypes (TREE_TYPE (inside_init), type))
4706 || (code == VECTOR_TYPE
4707 && comptypes (TREE_TYPE (inside_init), type))
4708 || (code == POINTER_TYPE
4709 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4710 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4711 TREE_TYPE (type)))))
4712 {
4713 if (code == POINTER_TYPE)
4714 {
4715 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4716 {
4717 if (TREE_CODE (inside_init) == STRING_CST
4718 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4719 inside_init = array_to_pointer_conversion (inside_init);
4720 else
4721 {
4722 error_init ("invalid use of non-lvalue array");
4723 return error_mark_node;
4724 }
4725 }
4726 }
4727
4728 if (code == VECTOR_TYPE)
4729 /* Although the types are compatible, we may require a
4730 conversion. */
4731 inside_init = convert (type, inside_init);
4732
4733 if (require_constant
4734 && (code == VECTOR_TYPE || !flag_isoc99)
4735 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4736 {
4737 /* As an extension, allow initializing objects with static storage
4738 duration with compound literals (which are then treated just as
4739 the brace enclosed list they contain). Also allow this for
4740 vectors, as we can only assign them with compound literals. */
4741 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4742 inside_init = DECL_INITIAL (decl);
4743 }
4744
4745 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4746 && TREE_CODE (inside_init) != CONSTRUCTOR)
4747 {
4748 error_init ("array initialized from non-constant array expression");
4749 return error_mark_node;
4750 }
4751
4752 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4753 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4754
4755 /* Compound expressions can only occur here if -pedantic or
4756 -pedantic-errors is specified. In the later case, we always want
4757 an error. In the former case, we simply want a warning. */
4758 if (require_constant && pedantic
4759 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4760 {
4761 inside_init
4762 = valid_compound_expr_initializer (inside_init,
4763 TREE_TYPE (inside_init));
4764 if (inside_init == error_mark_node)
4765 error_init ("initializer element is not constant");
4766 else
4767 pedwarn_init ("initializer element is not constant");
4768 if (flag_pedantic_errors)
4769 inside_init = error_mark_node;
4770 }
4771 else if (require_constant
4772 && !initializer_constant_valid_p (inside_init,
4773 TREE_TYPE (inside_init)))
4774 {
4775 error_init ("initializer element is not constant");
4776 inside_init = error_mark_node;
4777 }
4778
4779 /* Added to enable additional -Wmissing-format-attribute warnings. */
4780 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4781 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4782 NULL_TREE, 0);
4783 return inside_init;
4784 }
4785
4786 /* Handle scalar types, including conversions. */
4787
4788 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4789 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE
4790 || code == VECTOR_TYPE)
4791 {
4792 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4793 && (TREE_CODE (init) == STRING_CST
4794 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4795 init = array_to_pointer_conversion (init);
4796 inside_init
4797 = convert_for_assignment (type, init, ic_init,
4798 NULL_TREE, NULL_TREE, 0);
4799
4800 /* Check to see if we have already given an error message. */
4801 if (inside_init == error_mark_node)
4802 ;
4803 else if (require_constant && !TREE_CONSTANT (inside_init))
4804 {
4805 error_init ("initializer element is not constant");
4806 inside_init = error_mark_node;
4807 }
4808 else if (require_constant
4809 && !initializer_constant_valid_p (inside_init,
4810 TREE_TYPE (inside_init)))
4811 {
4812 error_init ("initializer element is not computable at load time");
4813 inside_init = error_mark_node;
4814 }
4815
4816 return inside_init;
4817 }
4818
4819 /* Come here only for records and arrays. */
4820
4821 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4822 {
4823 error_init ("variable-sized object may not be initialized");
4824 return error_mark_node;
4825 }
4826
4827 error_init ("invalid initializer");
4828 return error_mark_node;
4829 }
4830 \f
4831 /* Handle initializers that use braces. */
4832
4833 /* Type of object we are accumulating a constructor for.
4834 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4835 static tree constructor_type;
4836
4837 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4838 left to fill. */
4839 static tree constructor_fields;
4840
4841 /* For an ARRAY_TYPE, this is the specified index
4842 at which to store the next element we get. */
4843 static tree constructor_index;
4844
4845 /* For an ARRAY_TYPE, this is the maximum index. */
4846 static tree constructor_max_index;
4847
4848 /* For a RECORD_TYPE, this is the first field not yet written out. */
4849 static tree constructor_unfilled_fields;
4850
4851 /* For an ARRAY_TYPE, this is the index of the first element
4852 not yet written out. */
4853 static tree constructor_unfilled_index;
4854
4855 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4856 This is so we can generate gaps between fields, when appropriate. */
4857 static tree constructor_bit_index;
4858
4859 /* If we are saving up the elements rather than allocating them,
4860 this is the list of elements so far (in reverse order,
4861 most recent first). */
4862 static VEC(constructor_elt,gc) *constructor_elements;
4863
4864 /* 1 if constructor should be incrementally stored into a constructor chain,
4865 0 if all the elements should be kept in AVL tree. */
4866 static int constructor_incremental;
4867
4868 /* 1 if so far this constructor's elements are all compile-time constants. */
4869 static int constructor_constant;
4870
4871 /* 1 if so far this constructor's elements are all valid address constants. */
4872 static int constructor_simple;
4873
4874 /* 1 if this constructor is erroneous so far. */
4875 static int constructor_erroneous;
4876
4877 /* Structure for managing pending initializer elements, organized as an
4878 AVL tree. */
4879
4880 struct init_node
4881 {
4882 struct init_node *left, *right;
4883 struct init_node *parent;
4884 int balance;
4885 tree purpose;
4886 tree value;
4887 };
4888
4889 /* Tree of pending elements at this constructor level.
4890 These are elements encountered out of order
4891 which belong at places we haven't reached yet in actually
4892 writing the output.
4893 Will never hold tree nodes across GC runs. */
4894 static struct init_node *constructor_pending_elts;
4895
4896 /* The SPELLING_DEPTH of this constructor. */
4897 static int constructor_depth;
4898
4899 /* DECL node for which an initializer is being read.
4900 0 means we are reading a constructor expression
4901 such as (struct foo) {...}. */
4902 static tree constructor_decl;
4903
4904 /* Nonzero if this is an initializer for a top-level decl. */
4905 static int constructor_top_level;
4906
4907 /* Nonzero if there were any member designators in this initializer. */
4908 static int constructor_designated;
4909
4910 /* Nesting depth of designator list. */
4911 static int designator_depth;
4912
4913 /* Nonzero if there were diagnosed errors in this designator list. */
4914 static int designator_erroneous;
4915
4916 \f
4917 /* This stack has a level for each implicit or explicit level of
4918 structuring in the initializer, including the outermost one. It
4919 saves the values of most of the variables above. */
4920
4921 struct constructor_range_stack;
4922
4923 struct constructor_stack
4924 {
4925 struct constructor_stack *next;
4926 tree type;
4927 tree fields;
4928 tree index;
4929 tree max_index;
4930 tree unfilled_index;
4931 tree unfilled_fields;
4932 tree bit_index;
4933 VEC(constructor_elt,gc) *elements;
4934 struct init_node *pending_elts;
4935 int offset;
4936 int depth;
4937 /* If value nonzero, this value should replace the entire
4938 constructor at this level. */
4939 struct c_expr replacement_value;
4940 struct constructor_range_stack *range_stack;
4941 char constant;
4942 char simple;
4943 char implicit;
4944 char erroneous;
4945 char outer;
4946 char incremental;
4947 char designated;
4948 };
4949
4950 static struct constructor_stack *constructor_stack;
4951
4952 /* This stack represents designators from some range designator up to
4953 the last designator in the list. */
4954
4955 struct constructor_range_stack
4956 {
4957 struct constructor_range_stack *next, *prev;
4958 struct constructor_stack *stack;
4959 tree range_start;
4960 tree index;
4961 tree range_end;
4962 tree fields;
4963 };
4964
4965 static struct constructor_range_stack *constructor_range_stack;
4966
4967 /* This stack records separate initializers that are nested.
4968 Nested initializers can't happen in ANSI C, but GNU C allows them
4969 in cases like { ... (struct foo) { ... } ... }. */
4970
4971 struct initializer_stack
4972 {
4973 struct initializer_stack *next;
4974 tree decl;
4975 struct constructor_stack *constructor_stack;
4976 struct constructor_range_stack *constructor_range_stack;
4977 VEC(constructor_elt,gc) *elements;
4978 struct spelling *spelling;
4979 struct spelling *spelling_base;
4980 int spelling_size;
4981 char top_level;
4982 char require_constant_value;
4983 char require_constant_elements;
4984 };
4985
4986 static struct initializer_stack *initializer_stack;
4987 \f
4988 /* Prepare to parse and output the initializer for variable DECL. */
4989
4990 void
4991 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
4992 {
4993 const char *locus;
4994 struct initializer_stack *p = XNEW (struct initializer_stack);
4995
4996 p->decl = constructor_decl;
4997 p->require_constant_value = require_constant_value;
4998 p->require_constant_elements = require_constant_elements;
4999 p->constructor_stack = constructor_stack;
5000 p->constructor_range_stack = constructor_range_stack;
5001 p->elements = constructor_elements;
5002 p->spelling = spelling;
5003 p->spelling_base = spelling_base;
5004 p->spelling_size = spelling_size;
5005 p->top_level = constructor_top_level;
5006 p->next = initializer_stack;
5007 initializer_stack = p;
5008
5009 constructor_decl = decl;
5010 constructor_designated = 0;
5011 constructor_top_level = top_level;
5012
5013 if (decl != 0 && decl != error_mark_node)
5014 {
5015 require_constant_value = TREE_STATIC (decl);
5016 require_constant_elements
5017 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5018 /* For a scalar, you can always use any value to initialize,
5019 even within braces. */
5020 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5021 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5022 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5023 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5024 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5025 }
5026 else
5027 {
5028 require_constant_value = 0;
5029 require_constant_elements = 0;
5030 locus = "(anonymous)";
5031 }
5032
5033 constructor_stack = 0;
5034 constructor_range_stack = 0;
5035
5036 missing_braces_mentioned = 0;
5037
5038 spelling_base = 0;
5039 spelling_size = 0;
5040 RESTORE_SPELLING_DEPTH (0);
5041
5042 if (locus)
5043 push_string (locus);
5044 }
5045
5046 void
5047 finish_init (void)
5048 {
5049 struct initializer_stack *p = initializer_stack;
5050
5051 /* Free the whole constructor stack of this initializer. */
5052 while (constructor_stack)
5053 {
5054 struct constructor_stack *q = constructor_stack;
5055 constructor_stack = q->next;
5056 free (q);
5057 }
5058
5059 gcc_assert (!constructor_range_stack);
5060
5061 /* Pop back to the data of the outer initializer (if any). */
5062 free (spelling_base);
5063
5064 constructor_decl = p->decl;
5065 require_constant_value = p->require_constant_value;
5066 require_constant_elements = p->require_constant_elements;
5067 constructor_stack = p->constructor_stack;
5068 constructor_range_stack = p->constructor_range_stack;
5069 constructor_elements = p->elements;
5070 spelling = p->spelling;
5071 spelling_base = p->spelling_base;
5072 spelling_size = p->spelling_size;
5073 constructor_top_level = p->top_level;
5074 initializer_stack = p->next;
5075 free (p);
5076 }
5077 \f
5078 /* Call here when we see the initializer is surrounded by braces.
5079 This is instead of a call to push_init_level;
5080 it is matched by a call to pop_init_level.
5081
5082 TYPE is the type to initialize, for a constructor expression.
5083 For an initializer for a decl, TYPE is zero. */
5084
5085 void
5086 really_start_incremental_init (tree type)
5087 {
5088 struct constructor_stack *p = XNEW (struct constructor_stack);
5089
5090 if (type == 0)
5091 type = TREE_TYPE (constructor_decl);
5092
5093 if (targetm.vector_opaque_p (type))
5094 error ("opaque vector types cannot be initialized");
5095
5096 p->type = constructor_type;
5097 p->fields = constructor_fields;
5098 p->index = constructor_index;
5099 p->max_index = constructor_max_index;
5100 p->unfilled_index = constructor_unfilled_index;
5101 p->unfilled_fields = constructor_unfilled_fields;
5102 p->bit_index = constructor_bit_index;
5103 p->elements = constructor_elements;
5104 p->constant = constructor_constant;
5105 p->simple = constructor_simple;
5106 p->erroneous = constructor_erroneous;
5107 p->pending_elts = constructor_pending_elts;
5108 p->depth = constructor_depth;
5109 p->replacement_value.value = 0;
5110 p->replacement_value.original_code = ERROR_MARK;
5111 p->implicit = 0;
5112 p->range_stack = 0;
5113 p->outer = 0;
5114 p->incremental = constructor_incremental;
5115 p->designated = constructor_designated;
5116 p->next = 0;
5117 constructor_stack = p;
5118
5119 constructor_constant = 1;
5120 constructor_simple = 1;
5121 constructor_depth = SPELLING_DEPTH ();
5122 constructor_elements = 0;
5123 constructor_pending_elts = 0;
5124 constructor_type = type;
5125 constructor_incremental = 1;
5126 constructor_designated = 0;
5127 designator_depth = 0;
5128 designator_erroneous = 0;
5129
5130 if (TREE_CODE (constructor_type) == RECORD_TYPE
5131 || TREE_CODE (constructor_type) == UNION_TYPE)
5132 {
5133 constructor_fields = TYPE_FIELDS (constructor_type);
5134 /* Skip any nameless bit fields at the beginning. */
5135 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5136 && DECL_NAME (constructor_fields) == 0)
5137 constructor_fields = TREE_CHAIN (constructor_fields);
5138
5139 constructor_unfilled_fields = constructor_fields;
5140 constructor_bit_index = bitsize_zero_node;
5141 }
5142 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5143 {
5144 if (TYPE_DOMAIN (constructor_type))
5145 {
5146 constructor_max_index
5147 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5148
5149 /* Detect non-empty initializations of zero-length arrays. */
5150 if (constructor_max_index == NULL_TREE
5151 && TYPE_SIZE (constructor_type))
5152 constructor_max_index = build_int_cst (NULL_TREE, -1);
5153
5154 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5155 to initialize VLAs will cause a proper error; avoid tree
5156 checking errors as well by setting a safe value. */
5157 if (constructor_max_index
5158 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5159 constructor_max_index = build_int_cst (NULL_TREE, -1);
5160
5161 constructor_index
5162 = convert (bitsizetype,
5163 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5164 }
5165 else
5166 {
5167 constructor_index = bitsize_zero_node;
5168 constructor_max_index = NULL_TREE;
5169 }
5170
5171 constructor_unfilled_index = constructor_index;
5172 }
5173 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5174 {
5175 /* Vectors are like simple fixed-size arrays. */
5176 constructor_max_index =
5177 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5178 constructor_index = bitsize_zero_node;
5179 constructor_unfilled_index = constructor_index;
5180 }
5181 else
5182 {
5183 /* Handle the case of int x = {5}; */
5184 constructor_fields = constructor_type;
5185 constructor_unfilled_fields = constructor_type;
5186 }
5187 }
5188 \f
5189 /* Push down into a subobject, for initialization.
5190 If this is for an explicit set of braces, IMPLICIT is 0.
5191 If it is because the next element belongs at a lower level,
5192 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5193
5194 void
5195 push_init_level (int implicit)
5196 {
5197 struct constructor_stack *p;
5198 tree value = NULL_TREE;
5199
5200 /* If we've exhausted any levels that didn't have braces,
5201 pop them now. If implicit == 1, this will have been done in
5202 process_init_element; do not repeat it here because in the case
5203 of excess initializers for an empty aggregate this leads to an
5204 infinite cycle of popping a level and immediately recreating
5205 it. */
5206 if (implicit != 1)
5207 {
5208 while (constructor_stack->implicit)
5209 {
5210 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5211 || TREE_CODE (constructor_type) == UNION_TYPE)
5212 && constructor_fields == 0)
5213 process_init_element (pop_init_level (1));
5214 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5215 && constructor_max_index
5216 && tree_int_cst_lt (constructor_max_index,
5217 constructor_index))
5218 process_init_element (pop_init_level (1));
5219 else
5220 break;
5221 }
5222 }
5223
5224 /* Unless this is an explicit brace, we need to preserve previous
5225 content if any. */
5226 if (implicit)
5227 {
5228 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5229 || TREE_CODE (constructor_type) == UNION_TYPE)
5230 && constructor_fields)
5231 value = find_init_member (constructor_fields);
5232 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5233 value = find_init_member (constructor_index);
5234 }
5235
5236 p = XNEW (struct constructor_stack);
5237 p->type = constructor_type;
5238 p->fields = constructor_fields;
5239 p->index = constructor_index;
5240 p->max_index = constructor_max_index;
5241 p->unfilled_index = constructor_unfilled_index;
5242 p->unfilled_fields = constructor_unfilled_fields;
5243 p->bit_index = constructor_bit_index;
5244 p->elements = constructor_elements;
5245 p->constant = constructor_constant;
5246 p->simple = constructor_simple;
5247 p->erroneous = constructor_erroneous;
5248 p->pending_elts = constructor_pending_elts;
5249 p->depth = constructor_depth;
5250 p->replacement_value.value = 0;
5251 p->replacement_value.original_code = ERROR_MARK;
5252 p->implicit = implicit;
5253 p->outer = 0;
5254 p->incremental = constructor_incremental;
5255 p->designated = constructor_designated;
5256 p->next = constructor_stack;
5257 p->range_stack = 0;
5258 constructor_stack = p;
5259
5260 constructor_constant = 1;
5261 constructor_simple = 1;
5262 constructor_depth = SPELLING_DEPTH ();
5263 constructor_elements = 0;
5264 constructor_incremental = 1;
5265 constructor_designated = 0;
5266 constructor_pending_elts = 0;
5267 if (!implicit)
5268 {
5269 p->range_stack = constructor_range_stack;
5270 constructor_range_stack = 0;
5271 designator_depth = 0;
5272 designator_erroneous = 0;
5273 }
5274
5275 /* Don't die if an entire brace-pair level is superfluous
5276 in the containing level. */
5277 if (constructor_type == 0)
5278 ;
5279 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5280 || TREE_CODE (constructor_type) == UNION_TYPE)
5281 {
5282 /* Don't die if there are extra init elts at the end. */
5283 if (constructor_fields == 0)
5284 constructor_type = 0;
5285 else
5286 {
5287 constructor_type = TREE_TYPE (constructor_fields);
5288 push_member_name (constructor_fields);
5289 constructor_depth++;
5290 }
5291 }
5292 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5293 {
5294 constructor_type = TREE_TYPE (constructor_type);
5295 push_array_bounds (tree_low_cst (constructor_index, 1));
5296 constructor_depth++;
5297 }
5298
5299 if (constructor_type == 0)
5300 {
5301 error_init ("extra brace group at end of initializer");
5302 constructor_fields = 0;
5303 constructor_unfilled_fields = 0;
5304 return;
5305 }
5306
5307 if (value && TREE_CODE (value) == CONSTRUCTOR)
5308 {
5309 constructor_constant = TREE_CONSTANT (value);
5310 constructor_simple = TREE_STATIC (value);
5311 constructor_elements = CONSTRUCTOR_ELTS (value);
5312 if (!VEC_empty (constructor_elt, constructor_elements)
5313 && (TREE_CODE (constructor_type) == RECORD_TYPE
5314 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5315 set_nonincremental_init ();
5316 }
5317
5318 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5319 {
5320 missing_braces_mentioned = 1;
5321 warning_init ("missing braces around initializer");
5322 }
5323
5324 if (TREE_CODE (constructor_type) == RECORD_TYPE
5325 || TREE_CODE (constructor_type) == UNION_TYPE)
5326 {
5327 constructor_fields = TYPE_FIELDS (constructor_type);
5328 /* Skip any nameless bit fields at the beginning. */
5329 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5330 && DECL_NAME (constructor_fields) == 0)
5331 constructor_fields = TREE_CHAIN (constructor_fields);
5332
5333 constructor_unfilled_fields = constructor_fields;
5334 constructor_bit_index = bitsize_zero_node;
5335 }
5336 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5337 {
5338 /* Vectors are like simple fixed-size arrays. */
5339 constructor_max_index =
5340 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5341 constructor_index = convert (bitsizetype, integer_zero_node);
5342 constructor_unfilled_index = constructor_index;
5343 }
5344 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5345 {
5346 if (TYPE_DOMAIN (constructor_type))
5347 {
5348 constructor_max_index
5349 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5350
5351 /* Detect non-empty initializations of zero-length arrays. */
5352 if (constructor_max_index == NULL_TREE
5353 && TYPE_SIZE (constructor_type))
5354 constructor_max_index = build_int_cst (NULL_TREE, -1);
5355
5356 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5357 to initialize VLAs will cause a proper error; avoid tree
5358 checking errors as well by setting a safe value. */
5359 if (constructor_max_index
5360 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5361 constructor_max_index = build_int_cst (NULL_TREE, -1);
5362
5363 constructor_index
5364 = convert (bitsizetype,
5365 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5366 }
5367 else
5368 constructor_index = bitsize_zero_node;
5369
5370 constructor_unfilled_index = constructor_index;
5371 if (value && TREE_CODE (value) == STRING_CST)
5372 {
5373 /* We need to split the char/wchar array into individual
5374 characters, so that we don't have to special case it
5375 everywhere. */
5376 set_nonincremental_init_from_string (value);
5377 }
5378 }
5379 else
5380 {
5381 if (constructor_type != error_mark_node)
5382 warning_init ("braces around scalar initializer");
5383 constructor_fields = constructor_type;
5384 constructor_unfilled_fields = constructor_type;
5385 }
5386 }
5387
5388 /* At the end of an implicit or explicit brace level,
5389 finish up that level of constructor. If a single expression
5390 with redundant braces initialized that level, return the
5391 c_expr structure for that expression. Otherwise, the original_code
5392 element is set to ERROR_MARK.
5393 If we were outputting the elements as they are read, return 0 as the value
5394 from inner levels (process_init_element ignores that),
5395 but return error_mark_node as the value from the outermost level
5396 (that's what we want to put in DECL_INITIAL).
5397 Otherwise, return a CONSTRUCTOR expression as the value. */
5398
5399 struct c_expr
5400 pop_init_level (int implicit)
5401 {
5402 struct constructor_stack *p;
5403 struct c_expr ret;
5404 ret.value = 0;
5405 ret.original_code = ERROR_MARK;
5406
5407 if (implicit == 0)
5408 {
5409 /* When we come to an explicit close brace,
5410 pop any inner levels that didn't have explicit braces. */
5411 while (constructor_stack->implicit)
5412 process_init_element (pop_init_level (1));
5413
5414 gcc_assert (!constructor_range_stack);
5415 }
5416
5417 /* Now output all pending elements. */
5418 constructor_incremental = 1;
5419 output_pending_init_elements (1);
5420
5421 p = constructor_stack;
5422
5423 /* Error for initializing a flexible array member, or a zero-length
5424 array member in an inappropriate context. */
5425 if (constructor_type && constructor_fields
5426 && TREE_CODE (constructor_type) == ARRAY_TYPE
5427 && TYPE_DOMAIN (constructor_type)
5428 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5429 {
5430 /* Silently discard empty initializations. The parser will
5431 already have pedwarned for empty brackets. */
5432 if (integer_zerop (constructor_unfilled_index))
5433 constructor_type = NULL_TREE;
5434 else
5435 {
5436 gcc_assert (!TYPE_SIZE (constructor_type));
5437
5438 if (constructor_depth > 2)
5439 error_init ("initialization of flexible array member in a nested context");
5440 else if (pedantic)
5441 pedwarn_init ("initialization of a flexible array member");
5442
5443 /* We have already issued an error message for the existence
5444 of a flexible array member not at the end of the structure.
5445 Discard the initializer so that we do not die later. */
5446 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5447 constructor_type = NULL_TREE;
5448 }
5449 }
5450
5451 /* Warn when some struct elements are implicitly initialized to zero. */
5452 if (warn_missing_field_initializers
5453 && constructor_type
5454 && TREE_CODE (constructor_type) == RECORD_TYPE
5455 && constructor_unfilled_fields)
5456 {
5457 /* Do not warn for flexible array members or zero-length arrays. */
5458 while (constructor_unfilled_fields
5459 && (!DECL_SIZE (constructor_unfilled_fields)
5460 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5461 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5462
5463 /* Do not warn if this level of the initializer uses member
5464 designators; it is likely to be deliberate. */
5465 if (constructor_unfilled_fields && !constructor_designated)
5466 {
5467 push_member_name (constructor_unfilled_fields);
5468 warning_init ("missing initializer");
5469 RESTORE_SPELLING_DEPTH (constructor_depth);
5470 }
5471 }
5472
5473 /* Pad out the end of the structure. */
5474 if (p->replacement_value.value)
5475 /* If this closes a superfluous brace pair,
5476 just pass out the element between them. */
5477 ret = p->replacement_value;
5478 else if (constructor_type == 0)
5479 ;
5480 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5481 && TREE_CODE (constructor_type) != UNION_TYPE
5482 && TREE_CODE (constructor_type) != ARRAY_TYPE
5483 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5484 {
5485 /* A nonincremental scalar initializer--just return
5486 the element, after verifying there is just one. */
5487 if (VEC_empty (constructor_elt,constructor_elements))
5488 {
5489 if (!constructor_erroneous)
5490 error_init ("empty scalar initializer");
5491 ret.value = error_mark_node;
5492 }
5493 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5494 {
5495 error_init ("extra elements in scalar initializer");
5496 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5497 }
5498 else
5499 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5500 }
5501 else
5502 {
5503 if (constructor_erroneous)
5504 ret.value = error_mark_node;
5505 else
5506 {
5507 ret.value = build_constructor (constructor_type,
5508 constructor_elements);
5509 if (constructor_constant)
5510 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1;
5511 if (constructor_constant && constructor_simple)
5512 TREE_STATIC (ret.value) = 1;
5513 }
5514 }
5515
5516 constructor_type = p->type;
5517 constructor_fields = p->fields;
5518 constructor_index = p->index;
5519 constructor_max_index = p->max_index;
5520 constructor_unfilled_index = p->unfilled_index;
5521 constructor_unfilled_fields = p->unfilled_fields;
5522 constructor_bit_index = p->bit_index;
5523 constructor_elements = p->elements;
5524 constructor_constant = p->constant;
5525 constructor_simple = p->simple;
5526 constructor_erroneous = p->erroneous;
5527 constructor_incremental = p->incremental;
5528 constructor_designated = p->designated;
5529 constructor_pending_elts = p->pending_elts;
5530 constructor_depth = p->depth;
5531 if (!p->implicit)
5532 constructor_range_stack = p->range_stack;
5533 RESTORE_SPELLING_DEPTH (constructor_depth);
5534
5535 constructor_stack = p->next;
5536 free (p);
5537
5538 if (ret.value == 0 && constructor_stack == 0)
5539 ret.value = error_mark_node;
5540 return ret;
5541 }
5542
5543 /* Common handling for both array range and field name designators.
5544 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5545
5546 static int
5547 set_designator (int array)
5548 {
5549 tree subtype;
5550 enum tree_code subcode;
5551
5552 /* Don't die if an entire brace-pair level is superfluous
5553 in the containing level. */
5554 if (constructor_type == 0)
5555 return 1;
5556
5557 /* If there were errors in this designator list already, bail out
5558 silently. */
5559 if (designator_erroneous)
5560 return 1;
5561
5562 if (!designator_depth)
5563 {
5564 gcc_assert (!constructor_range_stack);
5565
5566 /* Designator list starts at the level of closest explicit
5567 braces. */
5568 while (constructor_stack->implicit)
5569 process_init_element (pop_init_level (1));
5570 constructor_designated = 1;
5571 return 0;
5572 }
5573
5574 switch (TREE_CODE (constructor_type))
5575 {
5576 case RECORD_TYPE:
5577 case UNION_TYPE:
5578 subtype = TREE_TYPE (constructor_fields);
5579 if (subtype != error_mark_node)
5580 subtype = TYPE_MAIN_VARIANT (subtype);
5581 break;
5582 case ARRAY_TYPE:
5583 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5584 break;
5585 default:
5586 gcc_unreachable ();
5587 }
5588
5589 subcode = TREE_CODE (subtype);
5590 if (array && subcode != ARRAY_TYPE)
5591 {
5592 error_init ("array index in non-array initializer");
5593 return 1;
5594 }
5595 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5596 {
5597 error_init ("field name not in record or union initializer");
5598 return 1;
5599 }
5600
5601 constructor_designated = 1;
5602 push_init_level (2);
5603 return 0;
5604 }
5605
5606 /* If there are range designators in designator list, push a new designator
5607 to constructor_range_stack. RANGE_END is end of such stack range or
5608 NULL_TREE if there is no range designator at this level. */
5609
5610 static void
5611 push_range_stack (tree range_end)
5612 {
5613 struct constructor_range_stack *p;
5614
5615 p = GGC_NEW (struct constructor_range_stack);
5616 p->prev = constructor_range_stack;
5617 p->next = 0;
5618 p->fields = constructor_fields;
5619 p->range_start = constructor_index;
5620 p->index = constructor_index;
5621 p->stack = constructor_stack;
5622 p->range_end = range_end;
5623 if (constructor_range_stack)
5624 constructor_range_stack->next = p;
5625 constructor_range_stack = p;
5626 }
5627
5628 /* Within an array initializer, specify the next index to be initialized.
5629 FIRST is that index. If LAST is nonzero, then initialize a range
5630 of indices, running from FIRST through LAST. */
5631
5632 void
5633 set_init_index (tree first, tree last)
5634 {
5635 if (set_designator (1))
5636 return;
5637
5638 designator_erroneous = 1;
5639
5640 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5641 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5642 {
5643 error_init ("array index in initializer not of integer type");
5644 return;
5645 }
5646
5647 if (TREE_CODE (first) != INTEGER_CST)
5648 error_init ("nonconstant array index in initializer");
5649 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5650 error_init ("nonconstant array index in initializer");
5651 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5652 error_init ("array index in non-array initializer");
5653 else if (tree_int_cst_sgn (first) == -1)
5654 error_init ("array index in initializer exceeds array bounds");
5655 else if (constructor_max_index
5656 && tree_int_cst_lt (constructor_max_index, first))
5657 error_init ("array index in initializer exceeds array bounds");
5658 else
5659 {
5660 constructor_index = convert (bitsizetype, first);
5661
5662 if (last)
5663 {
5664 if (tree_int_cst_equal (first, last))
5665 last = 0;
5666 else if (tree_int_cst_lt (last, first))
5667 {
5668 error_init ("empty index range in initializer");
5669 last = 0;
5670 }
5671 else
5672 {
5673 last = convert (bitsizetype, last);
5674 if (constructor_max_index != 0
5675 && tree_int_cst_lt (constructor_max_index, last))
5676 {
5677 error_init ("array index range in initializer exceeds array bounds");
5678 last = 0;
5679 }
5680 }
5681 }
5682
5683 designator_depth++;
5684 designator_erroneous = 0;
5685 if (constructor_range_stack || last)
5686 push_range_stack (last);
5687 }
5688 }
5689
5690 /* Within a struct initializer, specify the next field to be initialized. */
5691
5692 void
5693 set_init_label (tree fieldname)
5694 {
5695 tree tail;
5696
5697 if (set_designator (0))
5698 return;
5699
5700 designator_erroneous = 1;
5701
5702 if (TREE_CODE (constructor_type) != RECORD_TYPE
5703 && TREE_CODE (constructor_type) != UNION_TYPE)
5704 {
5705 error_init ("field name not in record or union initializer");
5706 return;
5707 }
5708
5709 for (tail = TYPE_FIELDS (constructor_type); tail;
5710 tail = TREE_CHAIN (tail))
5711 {
5712 if (DECL_NAME (tail) == fieldname)
5713 break;
5714 }
5715
5716 if (tail == 0)
5717 error ("unknown field %qE specified in initializer", fieldname);
5718 else
5719 {
5720 constructor_fields = tail;
5721 designator_depth++;
5722 designator_erroneous = 0;
5723 if (constructor_range_stack)
5724 push_range_stack (NULL_TREE);
5725 }
5726 }
5727 \f
5728 /* Add a new initializer to the tree of pending initializers. PURPOSE
5729 identifies the initializer, either array index or field in a structure.
5730 VALUE is the value of that index or field. */
5731
5732 static void
5733 add_pending_init (tree purpose, tree value)
5734 {
5735 struct init_node *p, **q, *r;
5736
5737 q = &constructor_pending_elts;
5738 p = 0;
5739
5740 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5741 {
5742 while (*q != 0)
5743 {
5744 p = *q;
5745 if (tree_int_cst_lt (purpose, p->purpose))
5746 q = &p->left;
5747 else if (tree_int_cst_lt (p->purpose, purpose))
5748 q = &p->right;
5749 else
5750 {
5751 if (TREE_SIDE_EFFECTS (p->value))
5752 warning_init ("initialized field with side-effects overwritten");
5753 else if (warn_override_init)
5754 warning_init ("initialized field overwritten");
5755 p->value = value;
5756 return;
5757 }
5758 }
5759 }
5760 else
5761 {
5762 tree bitpos;
5763
5764 bitpos = bit_position (purpose);
5765 while (*q != NULL)
5766 {
5767 p = *q;
5768 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5769 q = &p->left;
5770 else if (p->purpose != purpose)
5771 q = &p->right;
5772 else
5773 {
5774 if (TREE_SIDE_EFFECTS (p->value))
5775 warning_init ("initialized field with side-effects overwritten");
5776 else if (warn_override_init)
5777 warning_init ("initialized field overwritten");
5778 p->value = value;
5779 return;
5780 }
5781 }
5782 }
5783
5784 r = GGC_NEW (struct init_node);
5785 r->purpose = purpose;
5786 r->value = value;
5787
5788 *q = r;
5789 r->parent = p;
5790 r->left = 0;
5791 r->right = 0;
5792 r->balance = 0;
5793
5794 while (p)
5795 {
5796 struct init_node *s;
5797
5798 if (r == p->left)
5799 {
5800 if (p->balance == 0)
5801 p->balance = -1;
5802 else if (p->balance < 0)
5803 {
5804 if (r->balance < 0)
5805 {
5806 /* L rotation. */
5807 p->left = r->right;
5808 if (p->left)
5809 p->left->parent = p;
5810 r->right = p;
5811
5812 p->balance = 0;
5813 r->balance = 0;
5814
5815 s = p->parent;
5816 p->parent = r;
5817 r->parent = s;
5818 if (s)
5819 {
5820 if (s->left == p)
5821 s->left = r;
5822 else
5823 s->right = r;
5824 }
5825 else
5826 constructor_pending_elts = r;
5827 }
5828 else
5829 {
5830 /* LR rotation. */
5831 struct init_node *t = r->right;
5832
5833 r->right = t->left;
5834 if (r->right)
5835 r->right->parent = r;
5836 t->left = r;
5837
5838 p->left = t->right;
5839 if (p->left)
5840 p->left->parent = p;
5841 t->right = p;
5842
5843 p->balance = t->balance < 0;
5844 r->balance = -(t->balance > 0);
5845 t->balance = 0;
5846
5847 s = p->parent;
5848 p->parent = t;
5849 r->parent = t;
5850 t->parent = s;
5851 if (s)
5852 {
5853 if (s->left == p)
5854 s->left = t;
5855 else
5856 s->right = t;
5857 }
5858 else
5859 constructor_pending_elts = t;
5860 }
5861 break;
5862 }
5863 else
5864 {
5865 /* p->balance == +1; growth of left side balances the node. */
5866 p->balance = 0;
5867 break;
5868 }
5869 }
5870 else /* r == p->right */
5871 {
5872 if (p->balance == 0)
5873 /* Growth propagation from right side. */
5874 p->balance++;
5875 else if (p->balance > 0)
5876 {
5877 if (r->balance > 0)
5878 {
5879 /* R rotation. */
5880 p->right = r->left;
5881 if (p->right)
5882 p->right->parent = p;
5883 r->left = p;
5884
5885 p->balance = 0;
5886 r->balance = 0;
5887
5888 s = p->parent;
5889 p->parent = r;
5890 r->parent = s;
5891 if (s)
5892 {
5893 if (s->left == p)
5894 s->left = r;
5895 else
5896 s->right = r;
5897 }
5898 else
5899 constructor_pending_elts = r;
5900 }
5901 else /* r->balance == -1 */
5902 {
5903 /* RL rotation */
5904 struct init_node *t = r->left;
5905
5906 r->left = t->right;
5907 if (r->left)
5908 r->left->parent = r;
5909 t->right = r;
5910
5911 p->right = t->left;
5912 if (p->right)
5913 p->right->parent = p;
5914 t->left = p;
5915
5916 r->balance = (t->balance < 0);
5917 p->balance = -(t->balance > 0);
5918 t->balance = 0;
5919
5920 s = p->parent;
5921 p->parent = t;
5922 r->parent = t;
5923 t->parent = s;
5924 if (s)
5925 {
5926 if (s->left == p)
5927 s->left = t;
5928 else
5929 s->right = t;
5930 }
5931 else
5932 constructor_pending_elts = t;
5933 }
5934 break;
5935 }
5936 else
5937 {
5938 /* p->balance == -1; growth of right side balances the node. */
5939 p->balance = 0;
5940 break;
5941 }
5942 }
5943
5944 r = p;
5945 p = p->parent;
5946 }
5947 }
5948
5949 /* Build AVL tree from a sorted chain. */
5950
5951 static void
5952 set_nonincremental_init (void)
5953 {
5954 unsigned HOST_WIDE_INT ix;
5955 tree index, value;
5956
5957 if (TREE_CODE (constructor_type) != RECORD_TYPE
5958 && TREE_CODE (constructor_type) != ARRAY_TYPE)
5959 return;
5960
5961 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
5962 add_pending_init (index, value);
5963 constructor_elements = 0;
5964 if (TREE_CODE (constructor_type) == RECORD_TYPE)
5965 {
5966 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
5967 /* Skip any nameless bit fields at the beginning. */
5968 while (constructor_unfilled_fields != 0
5969 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
5970 && DECL_NAME (constructor_unfilled_fields) == 0)
5971 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5972
5973 }
5974 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5975 {
5976 if (TYPE_DOMAIN (constructor_type))
5977 constructor_unfilled_index
5978 = convert (bitsizetype,
5979 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5980 else
5981 constructor_unfilled_index = bitsize_zero_node;
5982 }
5983 constructor_incremental = 0;
5984 }
5985
5986 /* Build AVL tree from a string constant. */
5987
5988 static void
5989 set_nonincremental_init_from_string (tree str)
5990 {
5991 tree value, purpose, type;
5992 HOST_WIDE_INT val[2];
5993 const char *p, *end;
5994 int byte, wchar_bytes, charwidth, bitpos;
5995
5996 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
5997
5998 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5999 == TYPE_PRECISION (char_type_node))
6000 wchar_bytes = 1;
6001 else
6002 {
6003 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
6004 == TYPE_PRECISION (wchar_type_node));
6005 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
6006 }
6007 charwidth = TYPE_PRECISION (char_type_node);
6008 type = TREE_TYPE (constructor_type);
6009 p = TREE_STRING_POINTER (str);
6010 end = p + TREE_STRING_LENGTH (str);
6011
6012 for (purpose = bitsize_zero_node;
6013 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6014 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6015 {
6016 if (wchar_bytes == 1)
6017 {
6018 val[1] = (unsigned char) *p++;
6019 val[0] = 0;
6020 }
6021 else
6022 {
6023 val[0] = 0;
6024 val[1] = 0;
6025 for (byte = 0; byte < wchar_bytes; byte++)
6026 {
6027 if (BYTES_BIG_ENDIAN)
6028 bitpos = (wchar_bytes - byte - 1) * charwidth;
6029 else
6030 bitpos = byte * charwidth;
6031 val[bitpos < HOST_BITS_PER_WIDE_INT]
6032 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6033 << (bitpos % HOST_BITS_PER_WIDE_INT);
6034 }
6035 }
6036
6037 if (!TYPE_UNSIGNED (type))
6038 {
6039 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6040 if (bitpos < HOST_BITS_PER_WIDE_INT)
6041 {
6042 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6043 {
6044 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6045 val[0] = -1;
6046 }
6047 }
6048 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6049 {
6050 if (val[1] < 0)
6051 val[0] = -1;
6052 }
6053 else if (val[0] & (((HOST_WIDE_INT) 1)
6054 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6055 val[0] |= ((HOST_WIDE_INT) -1)
6056 << (bitpos - HOST_BITS_PER_WIDE_INT);
6057 }
6058
6059 value = build_int_cst_wide (type, val[1], val[0]);
6060 add_pending_init (purpose, value);
6061 }
6062
6063 constructor_incremental = 0;
6064 }
6065
6066 /* Return value of FIELD in pending initializer or zero if the field was
6067 not initialized yet. */
6068
6069 static tree
6070 find_init_member (tree field)
6071 {
6072 struct init_node *p;
6073
6074 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6075 {
6076 if (constructor_incremental
6077 && tree_int_cst_lt (field, constructor_unfilled_index))
6078 set_nonincremental_init ();
6079
6080 p = constructor_pending_elts;
6081 while (p)
6082 {
6083 if (tree_int_cst_lt (field, p->purpose))
6084 p = p->left;
6085 else if (tree_int_cst_lt (p->purpose, field))
6086 p = p->right;
6087 else
6088 return p->value;
6089 }
6090 }
6091 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6092 {
6093 tree bitpos = bit_position (field);
6094
6095 if (constructor_incremental
6096 && (!constructor_unfilled_fields
6097 || tree_int_cst_lt (bitpos,
6098 bit_position (constructor_unfilled_fields))))
6099 set_nonincremental_init ();
6100
6101 p = constructor_pending_elts;
6102 while (p)
6103 {
6104 if (field == p->purpose)
6105 return p->value;
6106 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6107 p = p->left;
6108 else
6109 p = p->right;
6110 }
6111 }
6112 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6113 {
6114 if (!VEC_empty (constructor_elt, constructor_elements)
6115 && (VEC_last (constructor_elt, constructor_elements)->index
6116 == field))
6117 return VEC_last (constructor_elt, constructor_elements)->value;
6118 }
6119 return 0;
6120 }
6121
6122 /* "Output" the next constructor element.
6123 At top level, really output it to assembler code now.
6124 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6125 TYPE is the data type that the containing data type wants here.
6126 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6127 If VALUE is a string constant, STRICT_STRING is true if it is
6128 unparenthesized or we should not warn here for it being parenthesized.
6129 For other types of VALUE, STRICT_STRING is not used.
6130
6131 PENDING if non-nil means output pending elements that belong
6132 right after this element. (PENDING is normally 1;
6133 it is 0 while outputting pending elements, to avoid recursion.) */
6134
6135 static void
6136 output_init_element (tree value, bool strict_string, tree type, tree field,
6137 int pending)
6138 {
6139 constructor_elt *celt;
6140
6141 if (type == error_mark_node || value == error_mark_node)
6142 {
6143 constructor_erroneous = 1;
6144 return;
6145 }
6146 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6147 && (TREE_CODE (value) == STRING_CST
6148 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6149 && !(TREE_CODE (value) == STRING_CST
6150 && TREE_CODE (type) == ARRAY_TYPE
6151 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6152 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6153 TYPE_MAIN_VARIANT (type)))
6154 value = array_to_pointer_conversion (value);
6155
6156 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6157 && require_constant_value && !flag_isoc99 && pending)
6158 {
6159 /* As an extension, allow initializing objects with static storage
6160 duration with compound literals (which are then treated just as
6161 the brace enclosed list they contain). */
6162 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6163 value = DECL_INITIAL (decl);
6164 }
6165
6166 if (value == error_mark_node)
6167 constructor_erroneous = 1;
6168 else if (!TREE_CONSTANT (value))
6169 constructor_constant = 0;
6170 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6171 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6172 || TREE_CODE (constructor_type) == UNION_TYPE)
6173 && DECL_C_BIT_FIELD (field)
6174 && TREE_CODE (value) != INTEGER_CST))
6175 constructor_simple = 0;
6176
6177 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6178 {
6179 if (require_constant_value)
6180 {
6181 error_init ("initializer element is not constant");
6182 value = error_mark_node;
6183 }
6184 else if (require_constant_elements)
6185 pedwarn ("initializer element is not computable at load time");
6186 }
6187
6188 /* If this field is empty (and not at the end of structure),
6189 don't do anything other than checking the initializer. */
6190 if (field
6191 && (TREE_TYPE (field) == error_mark_node
6192 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6193 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6194 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6195 || TREE_CHAIN (field)))))
6196 return;
6197
6198 value = digest_init (type, value, strict_string, require_constant_value);
6199 if (value == error_mark_node)
6200 {
6201 constructor_erroneous = 1;
6202 return;
6203 }
6204
6205 /* If this element doesn't come next in sequence,
6206 put it on constructor_pending_elts. */
6207 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6208 && (!constructor_incremental
6209 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6210 {
6211 if (constructor_incremental
6212 && tree_int_cst_lt (field, constructor_unfilled_index))
6213 set_nonincremental_init ();
6214
6215 add_pending_init (field, value);
6216 return;
6217 }
6218 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6219 && (!constructor_incremental
6220 || field != constructor_unfilled_fields))
6221 {
6222 /* We do this for records but not for unions. In a union,
6223 no matter which field is specified, it can be initialized
6224 right away since it starts at the beginning of the union. */
6225 if (constructor_incremental)
6226 {
6227 if (!constructor_unfilled_fields)
6228 set_nonincremental_init ();
6229 else
6230 {
6231 tree bitpos, unfillpos;
6232
6233 bitpos = bit_position (field);
6234 unfillpos = bit_position (constructor_unfilled_fields);
6235
6236 if (tree_int_cst_lt (bitpos, unfillpos))
6237 set_nonincremental_init ();
6238 }
6239 }
6240
6241 add_pending_init (field, value);
6242 return;
6243 }
6244 else if (TREE_CODE (constructor_type) == UNION_TYPE
6245 && !VEC_empty (constructor_elt, constructor_elements))
6246 {
6247 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6248 constructor_elements)->value))
6249 warning_init ("initialized field with side-effects overwritten");
6250 else if (warn_override_init)
6251 warning_init ("initialized field overwritten");
6252
6253 /* We can have just one union field set. */
6254 constructor_elements = 0;
6255 }
6256
6257 /* Otherwise, output this element either to
6258 constructor_elements or to the assembler file. */
6259
6260 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6261 celt->index = field;
6262 celt->value = value;
6263
6264 /* Advance the variable that indicates sequential elements output. */
6265 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6266 constructor_unfilled_index
6267 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6268 bitsize_one_node);
6269 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6270 {
6271 constructor_unfilled_fields
6272 = TREE_CHAIN (constructor_unfilled_fields);
6273
6274 /* Skip any nameless bit fields. */
6275 while (constructor_unfilled_fields != 0
6276 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6277 && DECL_NAME (constructor_unfilled_fields) == 0)
6278 constructor_unfilled_fields =
6279 TREE_CHAIN (constructor_unfilled_fields);
6280 }
6281 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6282 constructor_unfilled_fields = 0;
6283
6284 /* Now output any pending elements which have become next. */
6285 if (pending)
6286 output_pending_init_elements (0);
6287 }
6288
6289 /* Output any pending elements which have become next.
6290 As we output elements, constructor_unfilled_{fields,index}
6291 advances, which may cause other elements to become next;
6292 if so, they too are output.
6293
6294 If ALL is 0, we return when there are
6295 no more pending elements to output now.
6296
6297 If ALL is 1, we output space as necessary so that
6298 we can output all the pending elements. */
6299
6300 static void
6301 output_pending_init_elements (int all)
6302 {
6303 struct init_node *elt = constructor_pending_elts;
6304 tree next;
6305
6306 retry:
6307
6308 /* Look through the whole pending tree.
6309 If we find an element that should be output now,
6310 output it. Otherwise, set NEXT to the element
6311 that comes first among those still pending. */
6312
6313 next = 0;
6314 while (elt)
6315 {
6316 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6317 {
6318 if (tree_int_cst_equal (elt->purpose,
6319 constructor_unfilled_index))
6320 output_init_element (elt->value, true,
6321 TREE_TYPE (constructor_type),
6322 constructor_unfilled_index, 0);
6323 else if (tree_int_cst_lt (constructor_unfilled_index,
6324 elt->purpose))
6325 {
6326 /* Advance to the next smaller node. */
6327 if (elt->left)
6328 elt = elt->left;
6329 else
6330 {
6331 /* We have reached the smallest node bigger than the
6332 current unfilled index. Fill the space first. */
6333 next = elt->purpose;
6334 break;
6335 }
6336 }
6337 else
6338 {
6339 /* Advance to the next bigger node. */
6340 if (elt->right)
6341 elt = elt->right;
6342 else
6343 {
6344 /* We have reached the biggest node in a subtree. Find
6345 the parent of it, which is the next bigger node. */
6346 while (elt->parent && elt->parent->right == elt)
6347 elt = elt->parent;
6348 elt = elt->parent;
6349 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6350 elt->purpose))
6351 {
6352 next = elt->purpose;
6353 break;
6354 }
6355 }
6356 }
6357 }
6358 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6359 || TREE_CODE (constructor_type) == UNION_TYPE)
6360 {
6361 tree ctor_unfilled_bitpos, elt_bitpos;
6362
6363 /* If the current record is complete we are done. */
6364 if (constructor_unfilled_fields == 0)
6365 break;
6366
6367 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6368 elt_bitpos = bit_position (elt->purpose);
6369 /* We can't compare fields here because there might be empty
6370 fields in between. */
6371 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6372 {
6373 constructor_unfilled_fields = elt->purpose;
6374 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6375 elt->purpose, 0);
6376 }
6377 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6378 {
6379 /* Advance to the next smaller node. */
6380 if (elt->left)
6381 elt = elt->left;
6382 else
6383 {
6384 /* We have reached the smallest node bigger than the
6385 current unfilled field. Fill the space first. */
6386 next = elt->purpose;
6387 break;
6388 }
6389 }
6390 else
6391 {
6392 /* Advance to the next bigger node. */
6393 if (elt->right)
6394 elt = elt->right;
6395 else
6396 {
6397 /* We have reached the biggest node in a subtree. Find
6398 the parent of it, which is the next bigger node. */
6399 while (elt->parent && elt->parent->right == elt)
6400 elt = elt->parent;
6401 elt = elt->parent;
6402 if (elt
6403 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6404 bit_position (elt->purpose))))
6405 {
6406 next = elt->purpose;
6407 break;
6408 }
6409 }
6410 }
6411 }
6412 }
6413
6414 /* Ordinarily return, but not if we want to output all
6415 and there are elements left. */
6416 if (!(all && next != 0))
6417 return;
6418
6419 /* If it's not incremental, just skip over the gap, so that after
6420 jumping to retry we will output the next successive element. */
6421 if (TREE_CODE (constructor_type) == RECORD_TYPE
6422 || TREE_CODE (constructor_type) == UNION_TYPE)
6423 constructor_unfilled_fields = next;
6424 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6425 constructor_unfilled_index = next;
6426
6427 /* ELT now points to the node in the pending tree with the next
6428 initializer to output. */
6429 goto retry;
6430 }
6431 \f
6432 /* Add one non-braced element to the current constructor level.
6433 This adjusts the current position within the constructor's type.
6434 This may also start or terminate implicit levels
6435 to handle a partly-braced initializer.
6436
6437 Once this has found the correct level for the new element,
6438 it calls output_init_element. */
6439
6440 void
6441 process_init_element (struct c_expr value)
6442 {
6443 tree orig_value = value.value;
6444 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6445 bool strict_string = value.original_code == STRING_CST;
6446
6447 designator_depth = 0;
6448 designator_erroneous = 0;
6449
6450 /* Handle superfluous braces around string cst as in
6451 char x[] = {"foo"}; */
6452 if (string_flag
6453 && constructor_type
6454 && TREE_CODE (constructor_type) == ARRAY_TYPE
6455 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6456 && integer_zerop (constructor_unfilled_index))
6457 {
6458 if (constructor_stack->replacement_value.value)
6459 error_init ("excess elements in char array initializer");
6460 constructor_stack->replacement_value = value;
6461 return;
6462 }
6463
6464 if (constructor_stack->replacement_value.value != 0)
6465 {
6466 error_init ("excess elements in struct initializer");
6467 return;
6468 }
6469
6470 /* Ignore elements of a brace group if it is entirely superfluous
6471 and has already been diagnosed. */
6472 if (constructor_type == 0)
6473 return;
6474
6475 /* If we've exhausted any levels that didn't have braces,
6476 pop them now. */
6477 while (constructor_stack->implicit)
6478 {
6479 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6480 || TREE_CODE (constructor_type) == UNION_TYPE)
6481 && constructor_fields == 0)
6482 process_init_element (pop_init_level (1));
6483 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6484 && (constructor_max_index == 0
6485 || tree_int_cst_lt (constructor_max_index,
6486 constructor_index)))
6487 process_init_element (pop_init_level (1));
6488 else
6489 break;
6490 }
6491
6492 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6493 if (constructor_range_stack)
6494 {
6495 /* If value is a compound literal and we'll be just using its
6496 content, don't put it into a SAVE_EXPR. */
6497 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6498 || !require_constant_value
6499 || flag_isoc99)
6500 value.value = save_expr (value.value);
6501 }
6502
6503 while (1)
6504 {
6505 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6506 {
6507 tree fieldtype;
6508 enum tree_code fieldcode;
6509
6510 if (constructor_fields == 0)
6511 {
6512 pedwarn_init ("excess elements in struct initializer");
6513 break;
6514 }
6515
6516 fieldtype = TREE_TYPE (constructor_fields);
6517 if (fieldtype != error_mark_node)
6518 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6519 fieldcode = TREE_CODE (fieldtype);
6520
6521 /* Error for non-static initialization of a flexible array member. */
6522 if (fieldcode == ARRAY_TYPE
6523 && !require_constant_value
6524 && TYPE_SIZE (fieldtype) == NULL_TREE
6525 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6526 {
6527 error_init ("non-static initialization of a flexible array member");
6528 break;
6529 }
6530
6531 /* Accept a string constant to initialize a subarray. */
6532 if (value.value != 0
6533 && fieldcode == ARRAY_TYPE
6534 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6535 && string_flag)
6536 value.value = orig_value;
6537 /* Otherwise, if we have come to a subaggregate,
6538 and we don't have an element of its type, push into it. */
6539 else if (value.value != 0
6540 && value.value != error_mark_node
6541 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6542 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6543 || fieldcode == UNION_TYPE))
6544 {
6545 push_init_level (1);
6546 continue;
6547 }
6548
6549 if (value.value)
6550 {
6551 push_member_name (constructor_fields);
6552 output_init_element (value.value, strict_string,
6553 fieldtype, constructor_fields, 1);
6554 RESTORE_SPELLING_DEPTH (constructor_depth);
6555 }
6556 else
6557 /* Do the bookkeeping for an element that was
6558 directly output as a constructor. */
6559 {
6560 /* For a record, keep track of end position of last field. */
6561 if (DECL_SIZE (constructor_fields))
6562 constructor_bit_index
6563 = size_binop (PLUS_EXPR,
6564 bit_position (constructor_fields),
6565 DECL_SIZE (constructor_fields));
6566
6567 /* If the current field was the first one not yet written out,
6568 it isn't now, so update. */
6569 if (constructor_unfilled_fields == constructor_fields)
6570 {
6571 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6572 /* Skip any nameless bit fields. */
6573 while (constructor_unfilled_fields != 0
6574 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6575 && DECL_NAME (constructor_unfilled_fields) == 0)
6576 constructor_unfilled_fields =
6577 TREE_CHAIN (constructor_unfilled_fields);
6578 }
6579 }
6580
6581 constructor_fields = TREE_CHAIN (constructor_fields);
6582 /* Skip any nameless bit fields at the beginning. */
6583 while (constructor_fields != 0
6584 && DECL_C_BIT_FIELD (constructor_fields)
6585 && DECL_NAME (constructor_fields) == 0)
6586 constructor_fields = TREE_CHAIN (constructor_fields);
6587 }
6588 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6589 {
6590 tree fieldtype;
6591 enum tree_code fieldcode;
6592
6593 if (constructor_fields == 0)
6594 {
6595 pedwarn_init ("excess elements in union initializer");
6596 break;
6597 }
6598
6599 fieldtype = TREE_TYPE (constructor_fields);
6600 if (fieldtype != error_mark_node)
6601 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6602 fieldcode = TREE_CODE (fieldtype);
6603
6604 /* Warn that traditional C rejects initialization of unions.
6605 We skip the warning if the value is zero. This is done
6606 under the assumption that the zero initializer in user
6607 code appears conditioned on e.g. __STDC__ to avoid
6608 "missing initializer" warnings and relies on default
6609 initialization to zero in the traditional C case.
6610 We also skip the warning if the initializer is designated,
6611 again on the assumption that this must be conditional on
6612 __STDC__ anyway (and we've already complained about the
6613 member-designator already). */
6614 if (!in_system_header && !constructor_designated
6615 && !(value.value && (integer_zerop (value.value)
6616 || real_zerop (value.value))))
6617 warning (OPT_Wtraditional, "traditional C rejects initialization "
6618 "of unions");
6619
6620 /* Accept a string constant to initialize a subarray. */
6621 if (value.value != 0
6622 && fieldcode == ARRAY_TYPE
6623 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6624 && string_flag)
6625 value.value = orig_value;
6626 /* Otherwise, if we have come to a subaggregate,
6627 and we don't have an element of its type, push into it. */
6628 else if (value.value != 0
6629 && value.value != error_mark_node
6630 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6631 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6632 || fieldcode == UNION_TYPE))
6633 {
6634 push_init_level (1);
6635 continue;
6636 }
6637
6638 if (value.value)
6639 {
6640 push_member_name (constructor_fields);
6641 output_init_element (value.value, strict_string,
6642 fieldtype, constructor_fields, 1);
6643 RESTORE_SPELLING_DEPTH (constructor_depth);
6644 }
6645 else
6646 /* Do the bookkeeping for an element that was
6647 directly output as a constructor. */
6648 {
6649 constructor_bit_index = DECL_SIZE (constructor_fields);
6650 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6651 }
6652
6653 constructor_fields = 0;
6654 }
6655 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6656 {
6657 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6658 enum tree_code eltcode = TREE_CODE (elttype);
6659
6660 /* Accept a string constant to initialize a subarray. */
6661 if (value.value != 0
6662 && eltcode == ARRAY_TYPE
6663 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6664 && string_flag)
6665 value.value = orig_value;
6666 /* Otherwise, if we have come to a subaggregate,
6667 and we don't have an element of its type, push into it. */
6668 else if (value.value != 0
6669 && value.value != error_mark_node
6670 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6671 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6672 || eltcode == UNION_TYPE))
6673 {
6674 push_init_level (1);
6675 continue;
6676 }
6677
6678 if (constructor_max_index != 0
6679 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6680 || integer_all_onesp (constructor_max_index)))
6681 {
6682 pedwarn_init ("excess elements in array initializer");
6683 break;
6684 }
6685
6686 /* Now output the actual element. */
6687 if (value.value)
6688 {
6689 push_array_bounds (tree_low_cst (constructor_index, 1));
6690 output_init_element (value.value, strict_string,
6691 elttype, constructor_index, 1);
6692 RESTORE_SPELLING_DEPTH (constructor_depth);
6693 }
6694
6695 constructor_index
6696 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6697
6698 if (!value.value)
6699 /* If we are doing the bookkeeping for an element that was
6700 directly output as a constructor, we must update
6701 constructor_unfilled_index. */
6702 constructor_unfilled_index = constructor_index;
6703 }
6704 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6705 {
6706 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6707
6708 /* Do a basic check of initializer size. Note that vectors
6709 always have a fixed size derived from their type. */
6710 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6711 {
6712 pedwarn_init ("excess elements in vector initializer");
6713 break;
6714 }
6715
6716 /* Now output the actual element. */
6717 if (value.value)
6718 output_init_element (value.value, strict_string,
6719 elttype, constructor_index, 1);
6720
6721 constructor_index
6722 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6723
6724 if (!value.value)
6725 /* If we are doing the bookkeeping for an element that was
6726 directly output as a constructor, we must update
6727 constructor_unfilled_index. */
6728 constructor_unfilled_index = constructor_index;
6729 }
6730
6731 /* Handle the sole element allowed in a braced initializer
6732 for a scalar variable. */
6733 else if (constructor_type != error_mark_node
6734 && constructor_fields == 0)
6735 {
6736 pedwarn_init ("excess elements in scalar initializer");
6737 break;
6738 }
6739 else
6740 {
6741 if (value.value)
6742 output_init_element (value.value, strict_string,
6743 constructor_type, NULL_TREE, 1);
6744 constructor_fields = 0;
6745 }
6746
6747 /* Handle range initializers either at this level or anywhere higher
6748 in the designator stack. */
6749 if (constructor_range_stack)
6750 {
6751 struct constructor_range_stack *p, *range_stack;
6752 int finish = 0;
6753
6754 range_stack = constructor_range_stack;
6755 constructor_range_stack = 0;
6756 while (constructor_stack != range_stack->stack)
6757 {
6758 gcc_assert (constructor_stack->implicit);
6759 process_init_element (pop_init_level (1));
6760 }
6761 for (p = range_stack;
6762 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6763 p = p->prev)
6764 {
6765 gcc_assert (constructor_stack->implicit);
6766 process_init_element (pop_init_level (1));
6767 }
6768
6769 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6770 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6771 finish = 1;
6772
6773 while (1)
6774 {
6775 constructor_index = p->index;
6776 constructor_fields = p->fields;
6777 if (finish && p->range_end && p->index == p->range_start)
6778 {
6779 finish = 0;
6780 p->prev = 0;
6781 }
6782 p = p->next;
6783 if (!p)
6784 break;
6785 push_init_level (2);
6786 p->stack = constructor_stack;
6787 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6788 p->index = p->range_start;
6789 }
6790
6791 if (!finish)
6792 constructor_range_stack = range_stack;
6793 continue;
6794 }
6795
6796 break;
6797 }
6798
6799 constructor_range_stack = 0;
6800 }
6801 \f
6802 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6803 (guaranteed to be 'volatile' or null) and ARGS (represented using
6804 an ASM_EXPR node). */
6805 tree
6806 build_asm_stmt (tree cv_qualifier, tree args)
6807 {
6808 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6809 ASM_VOLATILE_P (args) = 1;
6810 return add_stmt (args);
6811 }
6812
6813 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6814 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6815 SIMPLE indicates whether there was anything at all after the
6816 string in the asm expression -- asm("blah") and asm("blah" : )
6817 are subtly different. We use a ASM_EXPR node to represent this. */
6818 tree
6819 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6820 bool simple)
6821 {
6822 tree tail;
6823 tree args;
6824 int i;
6825 const char *constraint;
6826 const char **oconstraints;
6827 bool allows_mem, allows_reg, is_inout;
6828 int ninputs, noutputs;
6829
6830 ninputs = list_length (inputs);
6831 noutputs = list_length (outputs);
6832 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6833
6834 string = resolve_asm_operand_names (string, outputs, inputs);
6835
6836 /* Remove output conversions that change the type but not the mode. */
6837 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6838 {
6839 tree output = TREE_VALUE (tail);
6840
6841 /* ??? Really, this should not be here. Users should be using a
6842 proper lvalue, dammit. But there's a long history of using casts
6843 in the output operands. In cases like longlong.h, this becomes a
6844 primitive form of typechecking -- if the cast can be removed, then
6845 the output operand had a type of the proper width; otherwise we'll
6846 get an error. Gross, but ... */
6847 STRIP_NOPS (output);
6848
6849 if (!lvalue_or_else (output, lv_asm))
6850 output = error_mark_node;
6851
6852 if (output != error_mark_node
6853 && (TREE_READONLY (output)
6854 || TYPE_READONLY (TREE_TYPE (output))
6855 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6856 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6857 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6858 readonly_error (output, lv_asm);
6859
6860 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6861 oconstraints[i] = constraint;
6862
6863 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6864 &allows_mem, &allows_reg, &is_inout))
6865 {
6866 /* If the operand is going to end up in memory,
6867 mark it addressable. */
6868 if (!allows_reg && !c_mark_addressable (output))
6869 output = error_mark_node;
6870 }
6871 else
6872 output = error_mark_node;
6873
6874 TREE_VALUE (tail) = output;
6875 }
6876
6877 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
6878 {
6879 tree input;
6880
6881 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6882 input = TREE_VALUE (tail);
6883
6884 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
6885 oconstraints, &allows_mem, &allows_reg))
6886 {
6887 /* If the operand is going to end up in memory,
6888 mark it addressable. */
6889 if (!allows_reg && allows_mem)
6890 {
6891 /* Strip the nops as we allow this case. FIXME, this really
6892 should be rejected or made deprecated. */
6893 STRIP_NOPS (input);
6894 if (!c_mark_addressable (input))
6895 input = error_mark_node;
6896 }
6897 }
6898 else
6899 input = error_mark_node;
6900
6901 TREE_VALUE (tail) = input;
6902 }
6903
6904 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
6905
6906 /* asm statements without outputs, including simple ones, are treated
6907 as volatile. */
6908 ASM_INPUT_P (args) = simple;
6909 ASM_VOLATILE_P (args) = (noutputs == 0);
6910
6911 return args;
6912 }
6913 \f
6914 /* Generate a goto statement to LABEL. */
6915
6916 tree
6917 c_finish_goto_label (tree label)
6918 {
6919 tree decl = lookup_label (label);
6920 if (!decl)
6921 return NULL_TREE;
6922
6923 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
6924 {
6925 error ("jump into statement expression");
6926 return NULL_TREE;
6927 }
6928
6929 if (C_DECL_UNJUMPABLE_VM (decl))
6930 {
6931 error ("jump into scope of identifier with variably modified type");
6932 return NULL_TREE;
6933 }
6934
6935 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
6936 {
6937 /* No jump from outside this statement expression context, so
6938 record that there is a jump from within this context. */
6939 struct c_label_list *nlist;
6940 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6941 nlist->next = label_context_stack_se->labels_used;
6942 nlist->label = decl;
6943 label_context_stack_se->labels_used = nlist;
6944 }
6945
6946 if (!C_DECL_UNDEFINABLE_VM (decl))
6947 {
6948 /* No jump from outside this context context of identifiers with
6949 variably modified type, so record that there is a jump from
6950 within this context. */
6951 struct c_label_list *nlist;
6952 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6953 nlist->next = label_context_stack_vm->labels_used;
6954 nlist->label = decl;
6955 label_context_stack_vm->labels_used = nlist;
6956 }
6957
6958 TREE_USED (decl) = 1;
6959 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
6960 }
6961
6962 /* Generate a computed goto statement to EXPR. */
6963
6964 tree
6965 c_finish_goto_ptr (tree expr)
6966 {
6967 if (pedantic)
6968 pedwarn ("ISO C forbids %<goto *expr;%>");
6969 expr = convert (ptr_type_node, expr);
6970 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
6971 }
6972
6973 /* Generate a C `return' statement. RETVAL is the expression for what
6974 to return, or a null pointer for `return;' with no value. */
6975
6976 tree
6977 c_finish_return (tree retval)
6978 {
6979 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
6980 bool no_warning = false;
6981
6982 if (TREE_THIS_VOLATILE (current_function_decl))
6983 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6984
6985 if (!retval)
6986 {
6987 current_function_returns_null = 1;
6988 if ((warn_return_type || flag_isoc99)
6989 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
6990 {
6991 pedwarn_c99 ("%<return%> with no value, in "
6992 "function returning non-void");
6993 no_warning = true;
6994 }
6995 }
6996 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
6997 {
6998 current_function_returns_null = 1;
6999 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
7000 pedwarn ("%<return%> with a value, in function returning void");
7001 }
7002 else
7003 {
7004 tree t = convert_for_assignment (valtype, retval, ic_return,
7005 NULL_TREE, NULL_TREE, 0);
7006 tree res = DECL_RESULT (current_function_decl);
7007 tree inner;
7008
7009 current_function_returns_value = 1;
7010 if (t == error_mark_node)
7011 return NULL_TREE;
7012
7013 inner = t = convert (TREE_TYPE (res), t);
7014
7015 /* Strip any conversions, additions, and subtractions, and see if
7016 we are returning the address of a local variable. Warn if so. */
7017 while (1)
7018 {
7019 switch (TREE_CODE (inner))
7020 {
7021 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
7022 case PLUS_EXPR:
7023 inner = TREE_OPERAND (inner, 0);
7024 continue;
7025
7026 case MINUS_EXPR:
7027 /* If the second operand of the MINUS_EXPR has a pointer
7028 type (or is converted from it), this may be valid, so
7029 don't give a warning. */
7030 {
7031 tree op1 = TREE_OPERAND (inner, 1);
7032
7033 while (!POINTER_TYPE_P (TREE_TYPE (op1))
7034 && (TREE_CODE (op1) == NOP_EXPR
7035 || TREE_CODE (op1) == NON_LVALUE_EXPR
7036 || TREE_CODE (op1) == CONVERT_EXPR))
7037 op1 = TREE_OPERAND (op1, 0);
7038
7039 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7040 break;
7041
7042 inner = TREE_OPERAND (inner, 0);
7043 continue;
7044 }
7045
7046 case ADDR_EXPR:
7047 inner = TREE_OPERAND (inner, 0);
7048
7049 while (REFERENCE_CLASS_P (inner)
7050 && TREE_CODE (inner) != INDIRECT_REF)
7051 inner = TREE_OPERAND (inner, 0);
7052
7053 if (DECL_P (inner)
7054 && !DECL_EXTERNAL (inner)
7055 && !TREE_STATIC (inner)
7056 && DECL_CONTEXT (inner) == current_function_decl)
7057 warning (0, "function returns address of local variable");
7058 break;
7059
7060 default:
7061 break;
7062 }
7063
7064 break;
7065 }
7066
7067 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7068 }
7069
7070 ret_stmt = build_stmt (RETURN_EXPR, retval);
7071 TREE_NO_WARNING (ret_stmt) |= no_warning;
7072 return add_stmt (ret_stmt);
7073 }
7074 \f
7075 struct c_switch {
7076 /* The SWITCH_EXPR being built. */
7077 tree switch_expr;
7078
7079 /* The original type of the testing expression, i.e. before the
7080 default conversion is applied. */
7081 tree orig_type;
7082
7083 /* A splay-tree mapping the low element of a case range to the high
7084 element, or NULL_TREE if there is no high element. Used to
7085 determine whether or not a new case label duplicates an old case
7086 label. We need a tree, rather than simply a hash table, because
7087 of the GNU case range extension. */
7088 splay_tree cases;
7089
7090 /* Number of nested statement expressions within this switch
7091 statement; if nonzero, case and default labels may not
7092 appear. */
7093 unsigned int blocked_stmt_expr;
7094
7095 /* Scope of outermost declarations of identifiers with variably
7096 modified type within this switch statement; if nonzero, case and
7097 default labels may not appear. */
7098 unsigned int blocked_vm;
7099
7100 /* The next node on the stack. */
7101 struct c_switch *next;
7102 };
7103
7104 /* A stack of the currently active switch statements. The innermost
7105 switch statement is on the top of the stack. There is no need to
7106 mark the stack for garbage collection because it is only active
7107 during the processing of the body of a function, and we never
7108 collect at that point. */
7109
7110 struct c_switch *c_switch_stack;
7111
7112 /* Start a C switch statement, testing expression EXP. Return the new
7113 SWITCH_EXPR. */
7114
7115 tree
7116 c_start_case (tree exp)
7117 {
7118 tree orig_type = error_mark_node;
7119 struct c_switch *cs;
7120
7121 if (exp != error_mark_node)
7122 {
7123 orig_type = TREE_TYPE (exp);
7124
7125 if (!INTEGRAL_TYPE_P (orig_type))
7126 {
7127 if (orig_type != error_mark_node)
7128 {
7129 error ("switch quantity not an integer");
7130 orig_type = error_mark_node;
7131 }
7132 exp = integer_zero_node;
7133 }
7134 else
7135 {
7136 tree type = TYPE_MAIN_VARIANT (orig_type);
7137
7138 if (!in_system_header
7139 && (type == long_integer_type_node
7140 || type == long_unsigned_type_node))
7141 warning (OPT_Wtraditional, "%<long%> switch expression not "
7142 "converted to %<int%> in ISO C");
7143
7144 exp = default_conversion (exp);
7145 }
7146 }
7147
7148 /* Add this new SWITCH_EXPR to the stack. */
7149 cs = XNEW (struct c_switch);
7150 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7151 cs->orig_type = orig_type;
7152 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7153 cs->blocked_stmt_expr = 0;
7154 cs->blocked_vm = 0;
7155 cs->next = c_switch_stack;
7156 c_switch_stack = cs;
7157
7158 return add_stmt (cs->switch_expr);
7159 }
7160
7161 /* Process a case label. */
7162
7163 tree
7164 do_case (tree low_value, tree high_value)
7165 {
7166 tree label = NULL_TREE;
7167
7168 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7169 && !c_switch_stack->blocked_vm)
7170 {
7171 label = c_add_case_label (c_switch_stack->cases,
7172 SWITCH_COND (c_switch_stack->switch_expr),
7173 c_switch_stack->orig_type,
7174 low_value, high_value);
7175 if (label == error_mark_node)
7176 label = NULL_TREE;
7177 }
7178 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7179 {
7180 if (low_value)
7181 error ("case label in statement expression not containing "
7182 "enclosing switch statement");
7183 else
7184 error ("%<default%> label in statement expression not containing "
7185 "enclosing switch statement");
7186 }
7187 else if (c_switch_stack && c_switch_stack->blocked_vm)
7188 {
7189 if (low_value)
7190 error ("case label in scope of identifier with variably modified "
7191 "type not containing enclosing switch statement");
7192 else
7193 error ("%<default%> label in scope of identifier with variably "
7194 "modified type not containing enclosing switch statement");
7195 }
7196 else if (low_value)
7197 error ("case label not within a switch statement");
7198 else
7199 error ("%<default%> label not within a switch statement");
7200
7201 return label;
7202 }
7203
7204 /* Finish the switch statement. */
7205
7206 void
7207 c_finish_case (tree body)
7208 {
7209 struct c_switch *cs = c_switch_stack;
7210 location_t switch_location;
7211
7212 SWITCH_BODY (cs->switch_expr) = body;
7213
7214 /* We must not be within a statement expression nested in the switch
7215 at this point; we might, however, be within the scope of an
7216 identifier with variably modified type nested in the switch. */
7217 gcc_assert (!cs->blocked_stmt_expr);
7218
7219 /* Emit warnings as needed. */
7220 if (EXPR_HAS_LOCATION (cs->switch_expr))
7221 switch_location = EXPR_LOCATION (cs->switch_expr);
7222 else
7223 switch_location = input_location;
7224 c_do_switch_warnings (cs->cases, switch_location,
7225 TREE_TYPE (cs->switch_expr),
7226 SWITCH_COND (cs->switch_expr));
7227
7228 /* Pop the stack. */
7229 c_switch_stack = cs->next;
7230 splay_tree_delete (cs->cases);
7231 XDELETE (cs);
7232 }
7233 \f
7234 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7235 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7236 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7237 statement, and was not surrounded with parenthesis. */
7238
7239 void
7240 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7241 tree else_block, bool nested_if)
7242 {
7243 tree stmt;
7244
7245 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7246 if (warn_parentheses && nested_if && else_block == NULL)
7247 {
7248 tree inner_if = then_block;
7249
7250 /* We know from the grammar productions that there is an IF nested
7251 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7252 it might not be exactly THEN_BLOCK, but should be the last
7253 non-container statement within. */
7254 while (1)
7255 switch (TREE_CODE (inner_if))
7256 {
7257 case COND_EXPR:
7258 goto found;
7259 case BIND_EXPR:
7260 inner_if = BIND_EXPR_BODY (inner_if);
7261 break;
7262 case STATEMENT_LIST:
7263 inner_if = expr_last (then_block);
7264 break;
7265 case TRY_FINALLY_EXPR:
7266 case TRY_CATCH_EXPR:
7267 inner_if = TREE_OPERAND (inner_if, 0);
7268 break;
7269 default:
7270 gcc_unreachable ();
7271 }
7272 found:
7273
7274 if (COND_EXPR_ELSE (inner_if))
7275 warning (OPT_Wparentheses,
7276 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7277 &if_locus);
7278 }
7279
7280 empty_body_warning (then_block, else_block);
7281
7282 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7283 SET_EXPR_LOCATION (stmt, if_locus);
7284 add_stmt (stmt);
7285 }
7286
7287 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7288 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7289 is false for DO loops. INCR is the FOR increment expression. BODY is
7290 the statement controlled by the loop. BLAB is the break label. CLAB is
7291 the continue label. Everything is allowed to be NULL. */
7292
7293 void
7294 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7295 tree blab, tree clab, bool cond_is_first)
7296 {
7297 tree entry = NULL, exit = NULL, t;
7298
7299 /* If the condition is zero don't generate a loop construct. */
7300 if (cond && integer_zerop (cond))
7301 {
7302 if (cond_is_first)
7303 {
7304 t = build_and_jump (&blab);
7305 SET_EXPR_LOCATION (t, start_locus);
7306 add_stmt (t);
7307 }
7308 }
7309 else
7310 {
7311 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7312
7313 /* If we have an exit condition, then we build an IF with gotos either
7314 out of the loop, or to the top of it. If there's no exit condition,
7315 then we just build a jump back to the top. */
7316 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7317
7318 if (cond && !integer_nonzerop (cond))
7319 {
7320 /* Canonicalize the loop condition to the end. This means
7321 generating a branch to the loop condition. Reuse the
7322 continue label, if possible. */
7323 if (cond_is_first)
7324 {
7325 if (incr || !clab)
7326 {
7327 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7328 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7329 }
7330 else
7331 t = build1 (GOTO_EXPR, void_type_node, clab);
7332 SET_EXPR_LOCATION (t, start_locus);
7333 add_stmt (t);
7334 }
7335
7336 t = build_and_jump (&blab);
7337 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7338 if (cond_is_first)
7339 SET_EXPR_LOCATION (exit, start_locus);
7340 else
7341 SET_EXPR_LOCATION (exit, input_location);
7342 }
7343
7344 add_stmt (top);
7345 }
7346
7347 if (body)
7348 add_stmt (body);
7349 if (clab)
7350 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7351 if (incr)
7352 add_stmt (incr);
7353 if (entry)
7354 add_stmt (entry);
7355 if (exit)
7356 add_stmt (exit);
7357 if (blab)
7358 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7359 }
7360
7361 tree
7362 c_finish_bc_stmt (tree *label_p, bool is_break)
7363 {
7364 bool skip;
7365 tree label = *label_p;
7366
7367 /* In switch statements break is sometimes stylistically used after
7368 a return statement. This can lead to spurious warnings about
7369 control reaching the end of a non-void function when it is
7370 inlined. Note that we are calling block_may_fallthru with
7371 language specific tree nodes; this works because
7372 block_may_fallthru returns true when given something it does not
7373 understand. */
7374 skip = !block_may_fallthru (cur_stmt_list);
7375
7376 if (!label)
7377 {
7378 if (!skip)
7379 *label_p = label = create_artificial_label ();
7380 }
7381 else if (TREE_CODE (label) == LABEL_DECL)
7382 ;
7383 else switch (TREE_INT_CST_LOW (label))
7384 {
7385 case 0:
7386 if (is_break)
7387 error ("break statement not within loop or switch");
7388 else
7389 error ("continue statement not within a loop");
7390 return NULL_TREE;
7391
7392 case 1:
7393 gcc_assert (is_break);
7394 error ("break statement used with OpenMP for loop");
7395 return NULL_TREE;
7396
7397 default:
7398 gcc_unreachable ();
7399 }
7400
7401 if (skip)
7402 return NULL_TREE;
7403
7404 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7405 }
7406
7407 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7408
7409 static void
7410 emit_side_effect_warnings (tree expr)
7411 {
7412 if (expr == error_mark_node)
7413 ;
7414 else if (!TREE_SIDE_EFFECTS (expr))
7415 {
7416 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7417 warning (0, "%Hstatement with no effect",
7418 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7419 }
7420 else if (warn_unused_value)
7421 warn_if_unused_value (expr, input_location);
7422 }
7423
7424 /* Process an expression as if it were a complete statement. Emit
7425 diagnostics, but do not call ADD_STMT. */
7426
7427 tree
7428 c_process_expr_stmt (tree expr)
7429 {
7430 if (!expr)
7431 return NULL_TREE;
7432
7433 if (warn_sequence_point)
7434 verify_sequence_points (expr);
7435
7436 if (TREE_TYPE (expr) != error_mark_node
7437 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7438 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7439 error ("expression statement has incomplete type");
7440
7441 /* If we're not processing a statement expression, warn about unused values.
7442 Warnings for statement expressions will be emitted later, once we figure
7443 out which is the result. */
7444 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7445 && (extra_warnings || warn_unused_value))
7446 emit_side_effect_warnings (expr);
7447
7448 /* If the expression is not of a type to which we cannot assign a line
7449 number, wrap the thing in a no-op NOP_EXPR. */
7450 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7451 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7452
7453 if (EXPR_P (expr))
7454 SET_EXPR_LOCATION (expr, input_location);
7455
7456 return expr;
7457 }
7458
7459 /* Emit an expression as a statement. */
7460
7461 tree
7462 c_finish_expr_stmt (tree expr)
7463 {
7464 if (expr)
7465 return add_stmt (c_process_expr_stmt (expr));
7466 else
7467 return NULL;
7468 }
7469
7470 /* Do the opposite and emit a statement as an expression. To begin,
7471 create a new binding level and return it. */
7472
7473 tree
7474 c_begin_stmt_expr (void)
7475 {
7476 tree ret;
7477 struct c_label_context_se *nstack;
7478 struct c_label_list *glist;
7479
7480 /* We must force a BLOCK for this level so that, if it is not expanded
7481 later, there is a way to turn off the entire subtree of blocks that
7482 are contained in it. */
7483 keep_next_level ();
7484 ret = c_begin_compound_stmt (true);
7485 if (c_switch_stack)
7486 {
7487 c_switch_stack->blocked_stmt_expr++;
7488 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7489 }
7490 for (glist = label_context_stack_se->labels_used;
7491 glist != NULL;
7492 glist = glist->next)
7493 {
7494 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7495 }
7496 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7497 nstack->labels_def = NULL;
7498 nstack->labels_used = NULL;
7499 nstack->next = label_context_stack_se;
7500 label_context_stack_se = nstack;
7501
7502 /* Mark the current statement list as belonging to a statement list. */
7503 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7504
7505 return ret;
7506 }
7507
7508 tree
7509 c_finish_stmt_expr (tree body)
7510 {
7511 tree last, type, tmp, val;
7512 tree *last_p;
7513 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7514
7515 body = c_end_compound_stmt (body, true);
7516 if (c_switch_stack)
7517 {
7518 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7519 c_switch_stack->blocked_stmt_expr--;
7520 }
7521 /* It is no longer possible to jump to labels defined within this
7522 statement expression. */
7523 for (dlist = label_context_stack_se->labels_def;
7524 dlist != NULL;
7525 dlist = dlist->next)
7526 {
7527 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7528 }
7529 /* It is again possible to define labels with a goto just outside
7530 this statement expression. */
7531 for (glist = label_context_stack_se->next->labels_used;
7532 glist != NULL;
7533 glist = glist->next)
7534 {
7535 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7536 glist_prev = glist;
7537 }
7538 if (glist_prev != NULL)
7539 glist_prev->next = label_context_stack_se->labels_used;
7540 else
7541 label_context_stack_se->next->labels_used
7542 = label_context_stack_se->labels_used;
7543 label_context_stack_se = label_context_stack_se->next;
7544
7545 /* Locate the last statement in BODY. See c_end_compound_stmt
7546 about always returning a BIND_EXPR. */
7547 last_p = &BIND_EXPR_BODY (body);
7548 last = BIND_EXPR_BODY (body);
7549
7550 continue_searching:
7551 if (TREE_CODE (last) == STATEMENT_LIST)
7552 {
7553 tree_stmt_iterator i;
7554
7555 /* This can happen with degenerate cases like ({ }). No value. */
7556 if (!TREE_SIDE_EFFECTS (last))
7557 return body;
7558
7559 /* If we're supposed to generate side effects warnings, process
7560 all of the statements except the last. */
7561 if (extra_warnings || warn_unused_value)
7562 {
7563 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7564 emit_side_effect_warnings (tsi_stmt (i));
7565 }
7566 else
7567 i = tsi_last (last);
7568 last_p = tsi_stmt_ptr (i);
7569 last = *last_p;
7570 }
7571
7572 /* If the end of the list is exception related, then the list was split
7573 by a call to push_cleanup. Continue searching. */
7574 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7575 || TREE_CODE (last) == TRY_CATCH_EXPR)
7576 {
7577 last_p = &TREE_OPERAND (last, 0);
7578 last = *last_p;
7579 goto continue_searching;
7580 }
7581
7582 /* In the case that the BIND_EXPR is not necessary, return the
7583 expression out from inside it. */
7584 if (last == error_mark_node
7585 || (last == BIND_EXPR_BODY (body)
7586 && BIND_EXPR_VARS (body) == NULL))
7587 {
7588 /* Do not warn if the return value of a statement expression is
7589 unused. */
7590 if (EXPR_P (last))
7591 TREE_NO_WARNING (last) = 1;
7592 return last;
7593 }
7594
7595 /* Extract the type of said expression. */
7596 type = TREE_TYPE (last);
7597
7598 /* If we're not returning a value at all, then the BIND_EXPR that
7599 we already have is a fine expression to return. */
7600 if (!type || VOID_TYPE_P (type))
7601 return body;
7602
7603 /* Now that we've located the expression containing the value, it seems
7604 silly to make voidify_wrapper_expr repeat the process. Create a
7605 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7606 tmp = create_tmp_var_raw (type, NULL);
7607
7608 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7609 tree_expr_nonnegative_p giving up immediately. */
7610 val = last;
7611 if (TREE_CODE (val) == NOP_EXPR
7612 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7613 val = TREE_OPERAND (val, 0);
7614
7615 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7616 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7617
7618 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7619 }
7620
7621 /* Begin the scope of an identifier of variably modified type, scope
7622 number SCOPE. Jumping from outside this scope to inside it is not
7623 permitted. */
7624
7625 void
7626 c_begin_vm_scope (unsigned int scope)
7627 {
7628 struct c_label_context_vm *nstack;
7629 struct c_label_list *glist;
7630
7631 gcc_assert (scope > 0);
7632
7633 /* At file_scope, we don't have to do any processing. */
7634 if (label_context_stack_vm == NULL)
7635 return;
7636
7637 if (c_switch_stack && !c_switch_stack->blocked_vm)
7638 c_switch_stack->blocked_vm = scope;
7639 for (glist = label_context_stack_vm->labels_used;
7640 glist != NULL;
7641 glist = glist->next)
7642 {
7643 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7644 }
7645 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7646 nstack->labels_def = NULL;
7647 nstack->labels_used = NULL;
7648 nstack->scope = scope;
7649 nstack->next = label_context_stack_vm;
7650 label_context_stack_vm = nstack;
7651 }
7652
7653 /* End a scope which may contain identifiers of variably modified
7654 type, scope number SCOPE. */
7655
7656 void
7657 c_end_vm_scope (unsigned int scope)
7658 {
7659 if (label_context_stack_vm == NULL)
7660 return;
7661 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7662 c_switch_stack->blocked_vm = 0;
7663 /* We may have a number of nested scopes of identifiers with
7664 variably modified type, all at this depth. Pop each in turn. */
7665 while (label_context_stack_vm->scope == scope)
7666 {
7667 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7668
7669 /* It is no longer possible to jump to labels defined within this
7670 scope. */
7671 for (dlist = label_context_stack_vm->labels_def;
7672 dlist != NULL;
7673 dlist = dlist->next)
7674 {
7675 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7676 }
7677 /* It is again possible to define labels with a goto just outside
7678 this scope. */
7679 for (glist = label_context_stack_vm->next->labels_used;
7680 glist != NULL;
7681 glist = glist->next)
7682 {
7683 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7684 glist_prev = glist;
7685 }
7686 if (glist_prev != NULL)
7687 glist_prev->next = label_context_stack_vm->labels_used;
7688 else
7689 label_context_stack_vm->next->labels_used
7690 = label_context_stack_vm->labels_used;
7691 label_context_stack_vm = label_context_stack_vm->next;
7692 }
7693 }
7694 \f
7695 /* Begin and end compound statements. This is as simple as pushing
7696 and popping new statement lists from the tree. */
7697
7698 tree
7699 c_begin_compound_stmt (bool do_scope)
7700 {
7701 tree stmt = push_stmt_list ();
7702 if (do_scope)
7703 push_scope ();
7704 return stmt;
7705 }
7706
7707 tree
7708 c_end_compound_stmt (tree stmt, bool do_scope)
7709 {
7710 tree block = NULL;
7711
7712 if (do_scope)
7713 {
7714 if (c_dialect_objc ())
7715 objc_clear_super_receiver ();
7716 block = pop_scope ();
7717 }
7718
7719 stmt = pop_stmt_list (stmt);
7720 stmt = c_build_bind_expr (block, stmt);
7721
7722 /* If this compound statement is nested immediately inside a statement
7723 expression, then force a BIND_EXPR to be created. Otherwise we'll
7724 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7725 STATEMENT_LISTs merge, and thus we can lose track of what statement
7726 was really last. */
7727 if (cur_stmt_list
7728 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7729 && TREE_CODE (stmt) != BIND_EXPR)
7730 {
7731 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7732 TREE_SIDE_EFFECTS (stmt) = 1;
7733 }
7734
7735 return stmt;
7736 }
7737
7738 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7739 when the current scope is exited. EH_ONLY is true when this is not
7740 meant to apply to normal control flow transfer. */
7741
7742 void
7743 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7744 {
7745 enum tree_code code;
7746 tree stmt, list;
7747 bool stmt_expr;
7748
7749 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7750 stmt = build_stmt (code, NULL, cleanup);
7751 add_stmt (stmt);
7752 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7753 list = push_stmt_list ();
7754 TREE_OPERAND (stmt, 0) = list;
7755 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7756 }
7757 \f
7758 /* Build a binary-operation expression without default conversions.
7759 CODE is the kind of expression to build.
7760 This function differs from `build' in several ways:
7761 the data type of the result is computed and recorded in it,
7762 warnings are generated if arg data types are invalid,
7763 special handling for addition and subtraction of pointers is known,
7764 and some optimization is done (operations on narrow ints
7765 are done in the narrower type when that gives the same result).
7766 Constant folding is also done before the result is returned.
7767
7768 Note that the operands will never have enumeral types, or function
7769 or array types, because either they will have the default conversions
7770 performed or they have both just been converted to some other type in which
7771 the arithmetic is to be done. */
7772
7773 tree
7774 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7775 int convert_p)
7776 {
7777 tree type0, type1;
7778 enum tree_code code0, code1;
7779 tree op0, op1;
7780 const char *invalid_op_diag;
7781
7782 /* Expression code to give to the expression when it is built.
7783 Normally this is CODE, which is what the caller asked for,
7784 but in some special cases we change it. */
7785 enum tree_code resultcode = code;
7786
7787 /* Data type in which the computation is to be performed.
7788 In the simplest cases this is the common type of the arguments. */
7789 tree result_type = NULL;
7790
7791 /* Nonzero means operands have already been type-converted
7792 in whatever way is necessary.
7793 Zero means they need to be converted to RESULT_TYPE. */
7794 int converted = 0;
7795
7796 /* Nonzero means create the expression with this type, rather than
7797 RESULT_TYPE. */
7798 tree build_type = 0;
7799
7800 /* Nonzero means after finally constructing the expression
7801 convert it to this type. */
7802 tree final_type = 0;
7803
7804 /* Nonzero if this is an operation like MIN or MAX which can
7805 safely be computed in short if both args are promoted shorts.
7806 Also implies COMMON.
7807 -1 indicates a bitwise operation; this makes a difference
7808 in the exact conditions for when it is safe to do the operation
7809 in a narrower mode. */
7810 int shorten = 0;
7811
7812 /* Nonzero if this is a comparison operation;
7813 if both args are promoted shorts, compare the original shorts.
7814 Also implies COMMON. */
7815 int short_compare = 0;
7816
7817 /* Nonzero if this is a right-shift operation, which can be computed on the
7818 original short and then promoted if the operand is a promoted short. */
7819 int short_shift = 0;
7820
7821 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7822 int common = 0;
7823
7824 /* True means types are compatible as far as ObjC is concerned. */
7825 bool objc_ok;
7826
7827 if (convert_p)
7828 {
7829 op0 = default_conversion (orig_op0);
7830 op1 = default_conversion (orig_op1);
7831 }
7832 else
7833 {
7834 op0 = orig_op0;
7835 op1 = orig_op1;
7836 }
7837
7838 type0 = TREE_TYPE (op0);
7839 type1 = TREE_TYPE (op1);
7840
7841 /* The expression codes of the data types of the arguments tell us
7842 whether the arguments are integers, floating, pointers, etc. */
7843 code0 = TREE_CODE (type0);
7844 code1 = TREE_CODE (type1);
7845
7846 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7847 STRIP_TYPE_NOPS (op0);
7848 STRIP_TYPE_NOPS (op1);
7849
7850 /* If an error was already reported for one of the arguments,
7851 avoid reporting another error. */
7852
7853 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7854 return error_mark_node;
7855
7856 if ((invalid_op_diag
7857 = targetm.invalid_binary_op (code, type0, type1)))
7858 {
7859 error (invalid_op_diag);
7860 return error_mark_node;
7861 }
7862
7863 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
7864
7865 switch (code)
7866 {
7867 case PLUS_EXPR:
7868 /* Handle the pointer + int case. */
7869 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7870 return pointer_int_sum (PLUS_EXPR, op0, op1);
7871 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
7872 return pointer_int_sum (PLUS_EXPR, op1, op0);
7873 else
7874 common = 1;
7875 break;
7876
7877 case MINUS_EXPR:
7878 /* Subtraction of two similar pointers.
7879 We must subtract them as integers, then divide by object size. */
7880 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
7881 && comp_target_types (type0, type1))
7882 return pointer_diff (op0, op1);
7883 /* Handle pointer minus int. Just like pointer plus int. */
7884 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7885 return pointer_int_sum (MINUS_EXPR, op0, op1);
7886 else
7887 common = 1;
7888 break;
7889
7890 case MULT_EXPR:
7891 common = 1;
7892 break;
7893
7894 case TRUNC_DIV_EXPR:
7895 case CEIL_DIV_EXPR:
7896 case FLOOR_DIV_EXPR:
7897 case ROUND_DIV_EXPR:
7898 case EXACT_DIV_EXPR:
7899 /* Floating point division by zero is a legitimate way to obtain
7900 infinities and NaNs. */
7901 if (skip_evaluation == 0 && integer_zerop (op1))
7902 warning (OPT_Wdiv_by_zero, "division by zero");
7903
7904 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7905 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7906 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7907 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
7908 {
7909 enum tree_code tcode0 = code0, tcode1 = code1;
7910
7911 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7912 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
7913 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
7914 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
7915
7916 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
7917 resultcode = RDIV_EXPR;
7918 else
7919 /* Although it would be tempting to shorten always here, that
7920 loses on some targets, since the modulo instruction is
7921 undefined if the quotient can't be represented in the
7922 computation mode. We shorten only if unsigned or if
7923 dividing by something we know != -1. */
7924 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7925 || (TREE_CODE (op1) == INTEGER_CST
7926 && !integer_all_onesp (op1)));
7927 common = 1;
7928 }
7929 break;
7930
7931 case BIT_AND_EXPR:
7932 case BIT_IOR_EXPR:
7933 case BIT_XOR_EXPR:
7934 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7935 shorten = -1;
7936 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
7937 common = 1;
7938 break;
7939
7940 case TRUNC_MOD_EXPR:
7941 case FLOOR_MOD_EXPR:
7942 if (skip_evaluation == 0 && integer_zerop (op1))
7943 warning (OPT_Wdiv_by_zero, "division by zero");
7944
7945 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7946 {
7947 /* Although it would be tempting to shorten always here, that loses
7948 on some targets, since the modulo instruction is undefined if the
7949 quotient can't be represented in the computation mode. We shorten
7950 only if unsigned or if dividing by something we know != -1. */
7951 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7952 || (TREE_CODE (op1) == INTEGER_CST
7953 && !integer_all_onesp (op1)));
7954 common = 1;
7955 }
7956 break;
7957
7958 case TRUTH_ANDIF_EXPR:
7959 case TRUTH_ORIF_EXPR:
7960 case TRUTH_AND_EXPR:
7961 case TRUTH_OR_EXPR:
7962 case TRUTH_XOR_EXPR:
7963 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
7964 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
7965 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
7966 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
7967 {
7968 /* Result of these operations is always an int,
7969 but that does not mean the operands should be
7970 converted to ints! */
7971 result_type = integer_type_node;
7972 op0 = c_common_truthvalue_conversion (op0);
7973 op1 = c_common_truthvalue_conversion (op1);
7974 converted = 1;
7975 }
7976 break;
7977
7978 /* Shift operations: result has same type as first operand;
7979 always convert second operand to int.
7980 Also set SHORT_SHIFT if shifting rightward. */
7981
7982 case RSHIFT_EXPR:
7983 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7984 {
7985 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7986 {
7987 if (tree_int_cst_sgn (op1) < 0)
7988 warning (0, "right shift count is negative");
7989 else
7990 {
7991 if (!integer_zerop (op1))
7992 short_shift = 1;
7993
7994 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7995 warning (0, "right shift count >= width of type");
7996 }
7997 }
7998
7999 /* Use the type of the value to be shifted. */
8000 result_type = type0;
8001 /* Convert the shift-count to an integer, regardless of size
8002 of value being shifted. */
8003 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8004 op1 = convert (integer_type_node, op1);
8005 /* Avoid converting op1 to result_type later. */
8006 converted = 1;
8007 }
8008 break;
8009
8010 case LSHIFT_EXPR:
8011 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8012 {
8013 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8014 {
8015 if (tree_int_cst_sgn (op1) < 0)
8016 warning (0, "left shift count is negative");
8017
8018 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8019 warning (0, "left shift count >= width of type");
8020 }
8021
8022 /* Use the type of the value to be shifted. */
8023 result_type = type0;
8024 /* Convert the shift-count to an integer, regardless of size
8025 of value being shifted. */
8026 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8027 op1 = convert (integer_type_node, op1);
8028 /* Avoid converting op1 to result_type later. */
8029 converted = 1;
8030 }
8031 break;
8032
8033 case EQ_EXPR:
8034 case NE_EXPR:
8035 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
8036 warning (OPT_Wfloat_equal,
8037 "comparing floating point with == or != is unsafe");
8038 /* Result of comparison is always int,
8039 but don't convert the args to int! */
8040 build_type = integer_type_node;
8041 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8042 || code0 == COMPLEX_TYPE)
8043 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8044 || code1 == COMPLEX_TYPE))
8045 short_compare = 1;
8046 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8047 {
8048 tree tt0 = TREE_TYPE (type0);
8049 tree tt1 = TREE_TYPE (type1);
8050 /* Anything compares with void *. void * compares with anything.
8051 Otherwise, the targets must be compatible
8052 and both must be object or both incomplete. */
8053 if (comp_target_types (type0, type1))
8054 result_type = common_pointer_type (type0, type1);
8055 else if (VOID_TYPE_P (tt0))
8056 {
8057 /* op0 != orig_op0 detects the case of something
8058 whose value is 0 but which isn't a valid null ptr const. */
8059 if (pedantic && !null_pointer_constant_p (orig_op0)
8060 && TREE_CODE (tt1) == FUNCTION_TYPE)
8061 pedwarn ("ISO C forbids comparison of %<void *%>"
8062 " with function pointer");
8063 }
8064 else if (VOID_TYPE_P (tt1))
8065 {
8066 if (pedantic && !null_pointer_constant_p (orig_op1)
8067 && TREE_CODE (tt0) == FUNCTION_TYPE)
8068 pedwarn ("ISO C forbids comparison of %<void *%>"
8069 " with function pointer");
8070 }
8071 else
8072 /* Avoid warning about the volatile ObjC EH puts on decls. */
8073 if (!objc_ok)
8074 pedwarn ("comparison of distinct pointer types lacks a cast");
8075
8076 if (result_type == NULL_TREE)
8077 result_type = ptr_type_node;
8078 }
8079 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8080 {
8081 if (TREE_CODE (op0) == ADDR_EXPR
8082 && DECL_P (TREE_OPERAND (op0, 0))
8083 && (TREE_CODE (TREE_OPERAND (op0, 0)) == PARM_DECL
8084 || TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL
8085 || !DECL_WEAK (TREE_OPERAND (op0, 0))))
8086 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8087 TREE_OPERAND (op0, 0));
8088 result_type = type0;
8089 }
8090 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8091 {
8092 if (TREE_CODE (op1) == ADDR_EXPR
8093 && DECL_P (TREE_OPERAND (op1, 0))
8094 && (TREE_CODE (TREE_OPERAND (op1, 0)) == PARM_DECL
8095 || TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL
8096 || !DECL_WEAK (TREE_OPERAND (op1, 0))))
8097 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8098 TREE_OPERAND (op1, 0));
8099 result_type = type1;
8100 }
8101 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8102 {
8103 result_type = type0;
8104 pedwarn ("comparison between pointer and integer");
8105 }
8106 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8107 {
8108 result_type = type1;
8109 pedwarn ("comparison between pointer and integer");
8110 }
8111 break;
8112
8113 case LE_EXPR:
8114 case GE_EXPR:
8115 case LT_EXPR:
8116 case GT_EXPR:
8117 build_type = integer_type_node;
8118 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
8119 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
8120 short_compare = 1;
8121 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8122 {
8123 if (comp_target_types (type0, type1))
8124 {
8125 result_type = common_pointer_type (type0, type1);
8126 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8127 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8128 pedwarn ("comparison of complete and incomplete pointers");
8129 else if (pedantic
8130 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8131 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
8132 }
8133 else
8134 {
8135 result_type = ptr_type_node;
8136 pedwarn ("comparison of distinct pointer types lacks a cast");
8137 }
8138 }
8139 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8140 {
8141 result_type = type0;
8142 if (pedantic || extra_warnings)
8143 pedwarn ("ordered comparison of pointer with integer zero");
8144 }
8145 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8146 {
8147 result_type = type1;
8148 if (pedantic)
8149 pedwarn ("ordered comparison of pointer with integer zero");
8150 }
8151 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8152 {
8153 result_type = type0;
8154 pedwarn ("comparison between pointer and integer");
8155 }
8156 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8157 {
8158 result_type = type1;
8159 pedwarn ("comparison between pointer and integer");
8160 }
8161 break;
8162
8163 default:
8164 gcc_unreachable ();
8165 }
8166
8167 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8168 return error_mark_node;
8169
8170 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8171 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8172 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8173 TREE_TYPE (type1))))
8174 {
8175 binary_op_error (code);
8176 return error_mark_node;
8177 }
8178
8179 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8180 || code0 == VECTOR_TYPE)
8181 &&
8182 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8183 || code1 == VECTOR_TYPE))
8184 {
8185 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8186
8187 if (shorten || common || short_compare)
8188 result_type = c_common_type (type0, type1);
8189
8190 /* For certain operations (which identify themselves by shorten != 0)
8191 if both args were extended from the same smaller type,
8192 do the arithmetic in that type and then extend.
8193
8194 shorten !=0 and !=1 indicates a bitwise operation.
8195 For them, this optimization is safe only if
8196 both args are zero-extended or both are sign-extended.
8197 Otherwise, we might change the result.
8198 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8199 but calculated in (unsigned short) it would be (unsigned short)-1. */
8200
8201 if (shorten && none_complex)
8202 {
8203 int unsigned0, unsigned1;
8204 tree arg0, arg1;
8205 int uns;
8206 tree type;
8207
8208 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8209 excessive narrowing when we call get_narrower below. For
8210 example, suppose that OP0 is of unsigned int extended
8211 from signed char and that RESULT_TYPE is long long int.
8212 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8213 like
8214
8215 (long long int) (unsigned int) signed_char
8216
8217 which get_narrower would narrow down to
8218
8219 (unsigned int) signed char
8220
8221 If we do not cast OP0 first, get_narrower would return
8222 signed_char, which is inconsistent with the case of the
8223 explicit cast. */
8224 op0 = convert (result_type, op0);
8225 op1 = convert (result_type, op1);
8226
8227 arg0 = get_narrower (op0, &unsigned0);
8228 arg1 = get_narrower (op1, &unsigned1);
8229
8230 /* UNS is 1 if the operation to be done is an unsigned one. */
8231 uns = TYPE_UNSIGNED (result_type);
8232
8233 final_type = result_type;
8234
8235 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8236 but it *requires* conversion to FINAL_TYPE. */
8237
8238 if ((TYPE_PRECISION (TREE_TYPE (op0))
8239 == TYPE_PRECISION (TREE_TYPE (arg0)))
8240 && TREE_TYPE (op0) != final_type)
8241 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
8242 if ((TYPE_PRECISION (TREE_TYPE (op1))
8243 == TYPE_PRECISION (TREE_TYPE (arg1)))
8244 && TREE_TYPE (op1) != final_type)
8245 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
8246
8247 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8248
8249 /* For bitwise operations, signedness of nominal type
8250 does not matter. Consider only how operands were extended. */
8251 if (shorten == -1)
8252 uns = unsigned0;
8253
8254 /* Note that in all three cases below we refrain from optimizing
8255 an unsigned operation on sign-extended args.
8256 That would not be valid. */
8257
8258 /* Both args variable: if both extended in same way
8259 from same width, do it in that width.
8260 Do it unsigned if args were zero-extended. */
8261 if ((TYPE_PRECISION (TREE_TYPE (arg0))
8262 < TYPE_PRECISION (result_type))
8263 && (TYPE_PRECISION (TREE_TYPE (arg1))
8264 == TYPE_PRECISION (TREE_TYPE (arg0)))
8265 && unsigned0 == unsigned1
8266 && (unsigned0 || !uns))
8267 result_type
8268 = c_common_signed_or_unsigned_type
8269 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
8270 else if (TREE_CODE (arg0) == INTEGER_CST
8271 && (unsigned1 || !uns)
8272 && (TYPE_PRECISION (TREE_TYPE (arg1))
8273 < TYPE_PRECISION (result_type))
8274 && (type
8275 = c_common_signed_or_unsigned_type (unsigned1,
8276 TREE_TYPE (arg1)),
8277 int_fits_type_p (arg0, type)))
8278 result_type = type;
8279 else if (TREE_CODE (arg1) == INTEGER_CST
8280 && (unsigned0 || !uns)
8281 && (TYPE_PRECISION (TREE_TYPE (arg0))
8282 < TYPE_PRECISION (result_type))
8283 && (type
8284 = c_common_signed_or_unsigned_type (unsigned0,
8285 TREE_TYPE (arg0)),
8286 int_fits_type_p (arg1, type)))
8287 result_type = type;
8288 }
8289
8290 /* Shifts can be shortened if shifting right. */
8291
8292 if (short_shift)
8293 {
8294 int unsigned_arg;
8295 tree arg0 = get_narrower (op0, &unsigned_arg);
8296
8297 final_type = result_type;
8298
8299 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8300 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8301
8302 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8303 /* We can shorten only if the shift count is less than the
8304 number of bits in the smaller type size. */
8305 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8306 /* We cannot drop an unsigned shift after sign-extension. */
8307 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8308 {
8309 /* Do an unsigned shift if the operand was zero-extended. */
8310 result_type
8311 = c_common_signed_or_unsigned_type (unsigned_arg,
8312 TREE_TYPE (arg0));
8313 /* Convert value-to-be-shifted to that type. */
8314 if (TREE_TYPE (op0) != result_type)
8315 op0 = convert (result_type, op0);
8316 converted = 1;
8317 }
8318 }
8319
8320 /* Comparison operations are shortened too but differently.
8321 They identify themselves by setting short_compare = 1. */
8322
8323 if (short_compare)
8324 {
8325 /* Don't write &op0, etc., because that would prevent op0
8326 from being kept in a register.
8327 Instead, make copies of the our local variables and
8328 pass the copies by reference, then copy them back afterward. */
8329 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8330 enum tree_code xresultcode = resultcode;
8331 tree val
8332 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8333
8334 if (val != 0)
8335 return val;
8336
8337 op0 = xop0, op1 = xop1;
8338 converted = 1;
8339 resultcode = xresultcode;
8340
8341 if (warn_sign_compare && skip_evaluation == 0)
8342 {
8343 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8344 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8345 int unsignedp0, unsignedp1;
8346 tree primop0 = get_narrower (op0, &unsignedp0);
8347 tree primop1 = get_narrower (op1, &unsignedp1);
8348
8349 xop0 = orig_op0;
8350 xop1 = orig_op1;
8351 STRIP_TYPE_NOPS (xop0);
8352 STRIP_TYPE_NOPS (xop1);
8353
8354 /* Give warnings for comparisons between signed and unsigned
8355 quantities that may fail.
8356
8357 Do the checking based on the original operand trees, so that
8358 casts will be considered, but default promotions won't be.
8359
8360 Do not warn if the comparison is being done in a signed type,
8361 since the signed type will only be chosen if it can represent
8362 all the values of the unsigned type. */
8363 if (!TYPE_UNSIGNED (result_type))
8364 /* OK */;
8365 /* Do not warn if both operands are the same signedness. */
8366 else if (op0_signed == op1_signed)
8367 /* OK */;
8368 else
8369 {
8370 tree sop, uop;
8371
8372 if (op0_signed)
8373 sop = xop0, uop = xop1;
8374 else
8375 sop = xop1, uop = xop0;
8376
8377 /* Do not warn if the signed quantity is an
8378 unsuffixed integer literal (or some static
8379 constant expression involving such literals or a
8380 conditional expression involving such literals)
8381 and it is non-negative. */
8382 if (tree_expr_nonnegative_p (sop))
8383 /* OK */;
8384 /* Do not warn if the comparison is an equality operation,
8385 the unsigned quantity is an integral constant, and it
8386 would fit in the result if the result were signed. */
8387 else if (TREE_CODE (uop) == INTEGER_CST
8388 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8389 && int_fits_type_p
8390 (uop, c_common_signed_type (result_type)))
8391 /* OK */;
8392 /* Do not warn if the unsigned quantity is an enumeration
8393 constant and its maximum value would fit in the result
8394 if the result were signed. */
8395 else if (TREE_CODE (uop) == INTEGER_CST
8396 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8397 && int_fits_type_p
8398 (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8399 c_common_signed_type (result_type)))
8400 /* OK */;
8401 else
8402 warning (0, "comparison between signed and unsigned");
8403 }
8404
8405 /* Warn if two unsigned values are being compared in a size
8406 larger than their original size, and one (and only one) is the
8407 result of a `~' operator. This comparison will always fail.
8408
8409 Also warn if one operand is a constant, and the constant
8410 does not have all bits set that are set in the ~ operand
8411 when it is extended. */
8412
8413 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
8414 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
8415 {
8416 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
8417 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
8418 &unsignedp0);
8419 else
8420 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
8421 &unsignedp1);
8422
8423 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
8424 {
8425 tree primop;
8426 HOST_WIDE_INT constant, mask;
8427 int unsignedp, bits;
8428
8429 if (host_integerp (primop0, 0))
8430 {
8431 primop = primop1;
8432 unsignedp = unsignedp1;
8433 constant = tree_low_cst (primop0, 0);
8434 }
8435 else
8436 {
8437 primop = primop0;
8438 unsignedp = unsignedp0;
8439 constant = tree_low_cst (primop1, 0);
8440 }
8441
8442 bits = TYPE_PRECISION (TREE_TYPE (primop));
8443 if (bits < TYPE_PRECISION (result_type)
8444 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
8445 {
8446 mask = (~(HOST_WIDE_INT) 0) << bits;
8447 if ((mask & constant) != mask)
8448 warning (0, "comparison of promoted ~unsigned with constant");
8449 }
8450 }
8451 else if (unsignedp0 && unsignedp1
8452 && (TYPE_PRECISION (TREE_TYPE (primop0))
8453 < TYPE_PRECISION (result_type))
8454 && (TYPE_PRECISION (TREE_TYPE (primop1))
8455 < TYPE_PRECISION (result_type)))
8456 warning (0, "comparison of promoted ~unsigned with unsigned");
8457 }
8458 }
8459 }
8460 }
8461
8462 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8463 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8464 Then the expression will be built.
8465 It will be given type FINAL_TYPE if that is nonzero;
8466 otherwise, it will be given type RESULT_TYPE. */
8467
8468 if (!result_type)
8469 {
8470 binary_op_error (code);
8471 return error_mark_node;
8472 }
8473
8474 if (!converted)
8475 {
8476 if (TREE_TYPE (op0) != result_type)
8477 op0 = convert_and_check (result_type, op0);
8478 if (TREE_TYPE (op1) != result_type)
8479 op1 = convert_and_check (result_type, op1);
8480
8481 /* This can happen if one operand has a vector type, and the other
8482 has a different type. */
8483 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8484 return error_mark_node;
8485 }
8486
8487 if (build_type == NULL_TREE)
8488 build_type = result_type;
8489
8490 {
8491 /* Treat expressions in initializers specially as they can't trap. */
8492 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8493 build_type,
8494 op0, op1)
8495 : fold_build2 (resultcode, build_type,
8496 op0, op1);
8497
8498 if (final_type != 0)
8499 result = convert (final_type, result);
8500 return result;
8501 }
8502 }
8503
8504
8505 /* Convert EXPR to be a truth-value, validating its type for this
8506 purpose. */
8507
8508 tree
8509 c_objc_common_truthvalue_conversion (tree expr)
8510 {
8511 switch (TREE_CODE (TREE_TYPE (expr)))
8512 {
8513 case ARRAY_TYPE:
8514 error ("used array that cannot be converted to pointer where scalar is required");
8515 return error_mark_node;
8516
8517 case RECORD_TYPE:
8518 error ("used struct type value where scalar is required");
8519 return error_mark_node;
8520
8521 case UNION_TYPE:
8522 error ("used union type value where scalar is required");
8523 return error_mark_node;
8524
8525 case FUNCTION_TYPE:
8526 gcc_unreachable ();
8527
8528 default:
8529 break;
8530 }
8531
8532 /* ??? Should we also give an error for void and vectors rather than
8533 leaving those to give errors later? */
8534 return c_common_truthvalue_conversion (expr);
8535 }
8536 \f
8537
8538 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8539 required. */
8540
8541 tree
8542 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
8543 bool *ti ATTRIBUTE_UNUSED, bool *se)
8544 {
8545 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8546 {
8547 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8548 /* Executing a compound literal inside a function reinitializes
8549 it. */
8550 if (!TREE_STATIC (decl))
8551 *se = true;
8552 return decl;
8553 }
8554 else
8555 return expr;
8556 }
8557 \f
8558 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8559
8560 tree
8561 c_begin_omp_parallel (void)
8562 {
8563 tree block;
8564
8565 keep_next_level ();
8566 block = c_begin_compound_stmt (true);
8567
8568 return block;
8569 }
8570
8571 tree
8572 c_finish_omp_parallel (tree clauses, tree block)
8573 {
8574 tree stmt;
8575
8576 block = c_end_compound_stmt (block, true);
8577
8578 stmt = make_node (OMP_PARALLEL);
8579 TREE_TYPE (stmt) = void_type_node;
8580 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8581 OMP_PARALLEL_BODY (stmt) = block;
8582
8583 return add_stmt (stmt);
8584 }
8585
8586 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8587 Remove any elements from the list that are invalid. */
8588
8589 tree
8590 c_finish_omp_clauses (tree clauses)
8591 {
8592 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8593 tree c, t, *pc = &clauses;
8594 const char *name;
8595
8596 bitmap_obstack_initialize (NULL);
8597 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8598 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8599 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8600
8601 for (pc = &clauses, c = clauses; c ; c = *pc)
8602 {
8603 bool remove = false;
8604 bool need_complete = false;
8605 bool need_implicitly_determined = false;
8606
8607 switch (OMP_CLAUSE_CODE (c))
8608 {
8609 case OMP_CLAUSE_SHARED:
8610 name = "shared";
8611 need_implicitly_determined = true;
8612 goto check_dup_generic;
8613
8614 case OMP_CLAUSE_PRIVATE:
8615 name = "private";
8616 need_complete = true;
8617 need_implicitly_determined = true;
8618 goto check_dup_generic;
8619
8620 case OMP_CLAUSE_REDUCTION:
8621 name = "reduction";
8622 need_implicitly_determined = true;
8623 t = OMP_CLAUSE_DECL (c);
8624 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8625 || POINTER_TYPE_P (TREE_TYPE (t)))
8626 {
8627 error ("%qE has invalid type for %<reduction%>", t);
8628 remove = true;
8629 }
8630 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8631 {
8632 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8633 const char *r_name = NULL;
8634
8635 switch (r_code)
8636 {
8637 case PLUS_EXPR:
8638 case MULT_EXPR:
8639 case MINUS_EXPR:
8640 break;
8641 case BIT_AND_EXPR:
8642 r_name = "&";
8643 break;
8644 case BIT_XOR_EXPR:
8645 r_name = "^";
8646 break;
8647 case BIT_IOR_EXPR:
8648 r_name = "|";
8649 break;
8650 case TRUTH_ANDIF_EXPR:
8651 r_name = "&&";
8652 break;
8653 case TRUTH_ORIF_EXPR:
8654 r_name = "||";
8655 break;
8656 default:
8657 gcc_unreachable ();
8658 }
8659 if (r_name)
8660 {
8661 error ("%qE has invalid type for %<reduction(%s)%>",
8662 t, r_name);
8663 remove = true;
8664 }
8665 }
8666 goto check_dup_generic;
8667
8668 case OMP_CLAUSE_COPYPRIVATE:
8669 name = "copyprivate";
8670 goto check_dup_generic;
8671
8672 case OMP_CLAUSE_COPYIN:
8673 name = "copyin";
8674 t = OMP_CLAUSE_DECL (c);
8675 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8676 {
8677 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8678 remove = true;
8679 }
8680 goto check_dup_generic;
8681
8682 check_dup_generic:
8683 t = OMP_CLAUSE_DECL (c);
8684 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8685 {
8686 error ("%qE is not a variable in clause %qs", t, name);
8687 remove = true;
8688 }
8689 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8690 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8691 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8692 {
8693 error ("%qE appears more than once in data clauses", t);
8694 remove = true;
8695 }
8696 else
8697 bitmap_set_bit (&generic_head, DECL_UID (t));
8698 break;
8699
8700 case OMP_CLAUSE_FIRSTPRIVATE:
8701 name = "firstprivate";
8702 t = OMP_CLAUSE_DECL (c);
8703 need_complete = true;
8704 need_implicitly_determined = true;
8705 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8706 {
8707 error ("%qE is not a variable in clause %<firstprivate%>", t);
8708 remove = true;
8709 }
8710 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8711 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8712 {
8713 error ("%qE appears more than once in data clauses", t);
8714 remove = true;
8715 }
8716 else
8717 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8718 break;
8719
8720 case OMP_CLAUSE_LASTPRIVATE:
8721 name = "lastprivate";
8722 t = OMP_CLAUSE_DECL (c);
8723 need_complete = true;
8724 need_implicitly_determined = true;
8725 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8726 {
8727 error ("%qE is not a variable in clause %<lastprivate%>", t);
8728 remove = true;
8729 }
8730 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8731 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8732 {
8733 error ("%qE appears more than once in data clauses", t);
8734 remove = true;
8735 }
8736 else
8737 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8738 break;
8739
8740 case OMP_CLAUSE_IF:
8741 case OMP_CLAUSE_NUM_THREADS:
8742 case OMP_CLAUSE_SCHEDULE:
8743 case OMP_CLAUSE_NOWAIT:
8744 case OMP_CLAUSE_ORDERED:
8745 case OMP_CLAUSE_DEFAULT:
8746 pc = &OMP_CLAUSE_CHAIN (c);
8747 continue;
8748
8749 default:
8750 gcc_unreachable ();
8751 }
8752
8753 if (!remove)
8754 {
8755 t = OMP_CLAUSE_DECL (c);
8756
8757 if (need_complete)
8758 {
8759 t = require_complete_type (t);
8760 if (t == error_mark_node)
8761 remove = true;
8762 }
8763
8764 if (need_implicitly_determined)
8765 {
8766 const char *share_name = NULL;
8767
8768 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8769 share_name = "threadprivate";
8770 else switch (c_omp_predetermined_sharing (t))
8771 {
8772 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8773 break;
8774 case OMP_CLAUSE_DEFAULT_SHARED:
8775 share_name = "shared";
8776 break;
8777 case OMP_CLAUSE_DEFAULT_PRIVATE:
8778 share_name = "private";
8779 break;
8780 default:
8781 gcc_unreachable ();
8782 }
8783 if (share_name)
8784 {
8785 error ("%qE is predetermined %qs for %qs",
8786 t, share_name, name);
8787 remove = true;
8788 }
8789 }
8790 }
8791
8792 if (remove)
8793 *pc = OMP_CLAUSE_CHAIN (c);
8794 else
8795 pc = &OMP_CLAUSE_CHAIN (c);
8796 }
8797
8798 bitmap_obstack_release (NULL);
8799 return clauses;
8800 }
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