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re PR c/30949 ("incompatible pointer type" warning does not point to declaration)
[gcc.git] / gcc / c-typeck.c
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22
23 /* This file is part of the C front end.
24 It contains routines to build C expressions given their operands,
25 including computing the types of the result, C-specific error checks,
26 and some optimization. */
27
28 #include "config.h"
29 #include "system.h"
30 #include "coretypes.h"
31 #include "tm.h"
32 #include "rtl.h"
33 #include "tree.h"
34 #include "langhooks.h"
35 #include "c-tree.h"
36 #include "tm_p.h"
37 #include "flags.h"
38 #include "output.h"
39 #include "expr.h"
40 #include "toplev.h"
41 #include "intl.h"
42 #include "ggc.h"
43 #include "target.h"
44 #include "tree-iterator.h"
45 #include "gimple.h"
46 #include "tree-flow.h"
47
48 /* Possible cases of implicit bad conversions. Used to select
49 diagnostic messages in convert_for_assignment. */
50 enum impl_conv {
51 ic_argpass,
52 ic_argpass_nonproto,
53 ic_assign,
54 ic_init,
55 ic_return
56 };
57
58 /* The level of nesting inside "__alignof__". */
59 int in_alignof;
60
61 /* The level of nesting inside "sizeof". */
62 int in_sizeof;
63
64 /* The level of nesting inside "typeof". */
65 int in_typeof;
66
67 struct c_label_context_se *label_context_stack_se;
68 struct c_label_context_vm *label_context_stack_vm;
69
70 /* Nonzero if we've already printed a "missing braces around initializer"
71 message within this initializer. */
72 static int missing_braces_mentioned;
73
74 static int require_constant_value;
75 static int require_constant_elements;
76
77 static bool null_pointer_constant_p (const_tree);
78 static tree qualify_type (tree, tree);
79 static int tagged_types_tu_compatible_p (const_tree, const_tree);
80 static int comp_target_types (tree, tree);
81 static int function_types_compatible_p (const_tree, const_tree);
82 static int type_lists_compatible_p (const_tree, const_tree);
83 static tree decl_constant_value_for_broken_optimization (tree);
84 static tree lookup_field (tree, tree);
85 static int convert_arguments (int, tree *, tree, tree, tree, tree);
86 static tree pointer_diff (tree, tree);
87 static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree,
88 int);
89 static tree valid_compound_expr_initializer (tree, tree);
90 static void push_string (const char *);
91 static void push_member_name (tree);
92 static int spelling_length (void);
93 static char *print_spelling (char *);
94 static void warning_init (int, const char *);
95 static tree digest_init (tree, tree, bool, int);
96 static void output_init_element (tree, bool, tree, tree, int);
97 static void output_pending_init_elements (int);
98 static int set_designator (int);
99 static void push_range_stack (tree);
100 static void add_pending_init (tree, tree);
101 static void set_nonincremental_init (void);
102 static void set_nonincremental_init_from_string (tree);
103 static tree find_init_member (tree);
104 static void readonly_error (tree, enum lvalue_use);
105 static int lvalue_or_else (const_tree, enum lvalue_use);
106 static int lvalue_p (const_tree);
107 static void record_maybe_used_decl (tree);
108 static int comptypes_internal (const_tree, const_tree);
109 \f
110 /* Return true if EXP is a null pointer constant, false otherwise. */
111
112 static bool
113 null_pointer_constant_p (const_tree expr)
114 {
115 /* This should really operate on c_expr structures, but they aren't
116 yet available everywhere required. */
117 tree type = TREE_TYPE (expr);
118 return (TREE_CODE (expr) == INTEGER_CST
119 && !TREE_OVERFLOW (expr)
120 && integer_zerop (expr)
121 && (INTEGRAL_TYPE_P (type)
122 || (TREE_CODE (type) == POINTER_TYPE
123 && VOID_TYPE_P (TREE_TYPE (type))
124 && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED)));
125 }
126 \f/* This is a cache to hold if two types are compatible or not. */
127
128 struct tagged_tu_seen_cache {
129 const struct tagged_tu_seen_cache * next;
130 const_tree t1;
131 const_tree t2;
132 /* The return value of tagged_types_tu_compatible_p if we had seen
133 these two types already. */
134 int val;
135 };
136
137 static const struct tagged_tu_seen_cache * tagged_tu_seen_base;
138 static void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *);
139
140 /* Do `exp = require_complete_type (exp);' to make sure exp
141 does not have an incomplete type. (That includes void types.) */
142
143 tree
144 require_complete_type (tree value)
145 {
146 tree type = TREE_TYPE (value);
147
148 if (value == error_mark_node || type == error_mark_node)
149 return error_mark_node;
150
151 /* First, detect a valid value with a complete type. */
152 if (COMPLETE_TYPE_P (type))
153 return value;
154
155 c_incomplete_type_error (value, type);
156 return error_mark_node;
157 }
158
159 /* Print an error message for invalid use of an incomplete type.
160 VALUE is the expression that was used (or 0 if that isn't known)
161 and TYPE is the type that was invalid. */
162
163 void
164 c_incomplete_type_error (const_tree value, const_tree type)
165 {
166 const char *type_code_string;
167
168 /* Avoid duplicate error message. */
169 if (TREE_CODE (type) == ERROR_MARK)
170 return;
171
172 if (value != 0 && (TREE_CODE (value) == VAR_DECL
173 || TREE_CODE (value) == PARM_DECL))
174 error ("%qD has an incomplete type", value);
175 else
176 {
177 retry:
178 /* We must print an error message. Be clever about what it says. */
179
180 switch (TREE_CODE (type))
181 {
182 case RECORD_TYPE:
183 type_code_string = "struct";
184 break;
185
186 case UNION_TYPE:
187 type_code_string = "union";
188 break;
189
190 case ENUMERAL_TYPE:
191 type_code_string = "enum";
192 break;
193
194 case VOID_TYPE:
195 error ("invalid use of void expression");
196 return;
197
198 case ARRAY_TYPE:
199 if (TYPE_DOMAIN (type))
200 {
201 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
202 {
203 error ("invalid use of flexible array member");
204 return;
205 }
206 type = TREE_TYPE (type);
207 goto retry;
208 }
209 error ("invalid use of array with unspecified bounds");
210 return;
211
212 default:
213 gcc_unreachable ();
214 }
215
216 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
217 error ("invalid use of undefined type %<%s %E%>",
218 type_code_string, TYPE_NAME (type));
219 else
220 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
221 error ("invalid use of incomplete typedef %qD", TYPE_NAME (type));
222 }
223 }
224
225 /* Given a type, apply default promotions wrt unnamed function
226 arguments and return the new type. */
227
228 tree
229 c_type_promotes_to (tree type)
230 {
231 if (TYPE_MAIN_VARIANT (type) == float_type_node)
232 return double_type_node;
233
234 if (c_promoting_integer_type_p (type))
235 {
236 /* Preserve unsignedness if not really getting any wider. */
237 if (TYPE_UNSIGNED (type)
238 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
239 return unsigned_type_node;
240 return integer_type_node;
241 }
242
243 return type;
244 }
245
246 /* Return a variant of TYPE which has all the type qualifiers of LIKE
247 as well as those of TYPE. */
248
249 static tree
250 qualify_type (tree type, tree like)
251 {
252 return c_build_qualified_type (type,
253 TYPE_QUALS (type) | TYPE_QUALS (like));
254 }
255
256 /* Return true iff the given tree T is a variable length array. */
257
258 bool
259 c_vla_type_p (const_tree t)
260 {
261 if (TREE_CODE (t) == ARRAY_TYPE
262 && C_TYPE_VARIABLE_SIZE (t))
263 return true;
264 return false;
265 }
266 \f
267 /* Return the composite type of two compatible types.
268
269 We assume that comptypes has already been done and returned
270 nonzero; if that isn't so, this may crash. In particular, we
271 assume that qualifiers match. */
272
273 tree
274 composite_type (tree t1, tree t2)
275 {
276 enum tree_code code1;
277 enum tree_code code2;
278 tree attributes;
279
280 /* Save time if the two types are the same. */
281
282 if (t1 == t2) return t1;
283
284 /* If one type is nonsense, use the other. */
285 if (t1 == error_mark_node)
286 return t2;
287 if (t2 == error_mark_node)
288 return t1;
289
290 code1 = TREE_CODE (t1);
291 code2 = TREE_CODE (t2);
292
293 /* Merge the attributes. */
294 attributes = targetm.merge_type_attributes (t1, t2);
295
296 /* If one is an enumerated type and the other is the compatible
297 integer type, the composite type might be either of the two
298 (DR#013 question 3). For consistency, use the enumerated type as
299 the composite type. */
300
301 if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE)
302 return t1;
303 if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE)
304 return t2;
305
306 gcc_assert (code1 == code2);
307
308 switch (code1)
309 {
310 case POINTER_TYPE:
311 /* For two pointers, do this recursively on the target type. */
312 {
313 tree pointed_to_1 = TREE_TYPE (t1);
314 tree pointed_to_2 = TREE_TYPE (t2);
315 tree target = composite_type (pointed_to_1, pointed_to_2);
316 t1 = build_pointer_type (target);
317 t1 = build_type_attribute_variant (t1, attributes);
318 return qualify_type (t1, t2);
319 }
320
321 case ARRAY_TYPE:
322 {
323 tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
324 int quals;
325 tree unqual_elt;
326 tree d1 = TYPE_DOMAIN (t1);
327 tree d2 = TYPE_DOMAIN (t2);
328 bool d1_variable, d2_variable;
329 bool d1_zero, d2_zero;
330
331 /* We should not have any type quals on arrays at all. */
332 gcc_assert (!TYPE_QUALS (t1) && !TYPE_QUALS (t2));
333
334 d1_zero = d1 == 0 || !TYPE_MAX_VALUE (d1);
335 d2_zero = d2 == 0 || !TYPE_MAX_VALUE (d2);
336
337 d1_variable = (!d1_zero
338 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
339 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
340 d2_variable = (!d2_zero
341 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
342 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
343 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
344 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
345
346 /* Save space: see if the result is identical to one of the args. */
347 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)
348 && (d2_variable || d2_zero || !d1_variable))
349 return build_type_attribute_variant (t1, attributes);
350 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)
351 && (d1_variable || d1_zero || !d2_variable))
352 return build_type_attribute_variant (t2, attributes);
353
354 if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
355 return build_type_attribute_variant (t1, attributes);
356 if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
357 return build_type_attribute_variant (t2, attributes);
358
359 /* Merge the element types, and have a size if either arg has
360 one. We may have qualifiers on the element types. To set
361 up TYPE_MAIN_VARIANT correctly, we need to form the
362 composite of the unqualified types and add the qualifiers
363 back at the end. */
364 quals = TYPE_QUALS (strip_array_types (elt));
365 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
366 t1 = build_array_type (unqual_elt,
367 TYPE_DOMAIN ((TYPE_DOMAIN (t1)
368 && (d2_variable
369 || d2_zero
370 || !d1_variable))
371 ? t1
372 : t2));
373 t1 = c_build_qualified_type (t1, quals);
374 return build_type_attribute_variant (t1, attributes);
375 }
376
377 case ENUMERAL_TYPE:
378 case RECORD_TYPE:
379 case UNION_TYPE:
380 if (attributes != NULL)
381 {
382 /* Try harder not to create a new aggregate type. */
383 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
384 return t1;
385 if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
386 return t2;
387 }
388 return build_type_attribute_variant (t1, attributes);
389
390 case FUNCTION_TYPE:
391 /* Function types: prefer the one that specified arg types.
392 If both do, merge the arg types. Also merge the return types. */
393 {
394 tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
395 tree p1 = TYPE_ARG_TYPES (t1);
396 tree p2 = TYPE_ARG_TYPES (t2);
397 int len;
398 tree newargs, n;
399 int i;
400
401 /* Save space: see if the result is identical to one of the args. */
402 if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2))
403 return build_type_attribute_variant (t1, attributes);
404 if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1))
405 return build_type_attribute_variant (t2, attributes);
406
407 /* Simple way if one arg fails to specify argument types. */
408 if (TYPE_ARG_TYPES (t1) == 0)
409 {
410 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
411 t1 = build_type_attribute_variant (t1, attributes);
412 return qualify_type (t1, t2);
413 }
414 if (TYPE_ARG_TYPES (t2) == 0)
415 {
416 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
417 t1 = build_type_attribute_variant (t1, attributes);
418 return qualify_type (t1, t2);
419 }
420
421 /* If both args specify argument types, we must merge the two
422 lists, argument by argument. */
423 /* Tell global_bindings_p to return false so that variable_size
424 doesn't die on VLAs in parameter types. */
425 c_override_global_bindings_to_false = true;
426
427 len = list_length (p1);
428 newargs = 0;
429
430 for (i = 0; i < len; i++)
431 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
432
433 n = newargs;
434
435 for (; p1;
436 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
437 {
438 /* A null type means arg type is not specified.
439 Take whatever the other function type has. */
440 if (TREE_VALUE (p1) == 0)
441 {
442 TREE_VALUE (n) = TREE_VALUE (p2);
443 goto parm_done;
444 }
445 if (TREE_VALUE (p2) == 0)
446 {
447 TREE_VALUE (n) = TREE_VALUE (p1);
448 goto parm_done;
449 }
450
451 /* Given wait (union {union wait *u; int *i} *)
452 and wait (union wait *),
453 prefer union wait * as type of parm. */
454 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
455 && TREE_VALUE (p1) != TREE_VALUE (p2))
456 {
457 tree memb;
458 tree mv2 = TREE_VALUE (p2);
459 if (mv2 && mv2 != error_mark_node
460 && TREE_CODE (mv2) != ARRAY_TYPE)
461 mv2 = TYPE_MAIN_VARIANT (mv2);
462 for (memb = TYPE_FIELDS (TREE_VALUE (p1));
463 memb; memb = TREE_CHAIN (memb))
464 {
465 tree mv3 = TREE_TYPE (memb);
466 if (mv3 && mv3 != error_mark_node
467 && TREE_CODE (mv3) != ARRAY_TYPE)
468 mv3 = TYPE_MAIN_VARIANT (mv3);
469 if (comptypes (mv3, mv2))
470 {
471 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
472 TREE_VALUE (p2));
473 pedwarn (input_location, OPT_pedantic,
474 "function types not truly compatible in ISO C");
475 goto parm_done;
476 }
477 }
478 }
479 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
480 && TREE_VALUE (p2) != TREE_VALUE (p1))
481 {
482 tree memb;
483 tree mv1 = TREE_VALUE (p1);
484 if (mv1 && mv1 != error_mark_node
485 && TREE_CODE (mv1) != ARRAY_TYPE)
486 mv1 = TYPE_MAIN_VARIANT (mv1);
487 for (memb = TYPE_FIELDS (TREE_VALUE (p2));
488 memb; memb = TREE_CHAIN (memb))
489 {
490 tree mv3 = TREE_TYPE (memb);
491 if (mv3 && mv3 != error_mark_node
492 && TREE_CODE (mv3) != ARRAY_TYPE)
493 mv3 = TYPE_MAIN_VARIANT (mv3);
494 if (comptypes (mv3, mv1))
495 {
496 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
497 TREE_VALUE (p1));
498 pedwarn (input_location, OPT_pedantic,
499 "function types not truly compatible in ISO C");
500 goto parm_done;
501 }
502 }
503 }
504 TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2));
505 parm_done: ;
506 }
507
508 c_override_global_bindings_to_false = false;
509 t1 = build_function_type (valtype, newargs);
510 t1 = qualify_type (t1, t2);
511 /* ... falls through ... */
512 }
513
514 default:
515 return build_type_attribute_variant (t1, attributes);
516 }
517
518 }
519
520 /* Return the type of a conditional expression between pointers to
521 possibly differently qualified versions of compatible types.
522
523 We assume that comp_target_types has already been done and returned
524 nonzero; if that isn't so, this may crash. */
525
526 static tree
527 common_pointer_type (tree t1, tree t2)
528 {
529 tree attributes;
530 tree pointed_to_1, mv1;
531 tree pointed_to_2, mv2;
532 tree target;
533 unsigned target_quals;
534
535 /* Save time if the two types are the same. */
536
537 if (t1 == t2) return t1;
538
539 /* If one type is nonsense, use the other. */
540 if (t1 == error_mark_node)
541 return t2;
542 if (t2 == error_mark_node)
543 return t1;
544
545 gcc_assert (TREE_CODE (t1) == POINTER_TYPE
546 && TREE_CODE (t2) == POINTER_TYPE);
547
548 /* Merge the attributes. */
549 attributes = targetm.merge_type_attributes (t1, t2);
550
551 /* Find the composite type of the target types, and combine the
552 qualifiers of the two types' targets. Do not lose qualifiers on
553 array element types by taking the TYPE_MAIN_VARIANT. */
554 mv1 = pointed_to_1 = TREE_TYPE (t1);
555 mv2 = pointed_to_2 = TREE_TYPE (t2);
556 if (TREE_CODE (mv1) != ARRAY_TYPE)
557 mv1 = TYPE_MAIN_VARIANT (pointed_to_1);
558 if (TREE_CODE (mv2) != ARRAY_TYPE)
559 mv2 = TYPE_MAIN_VARIANT (pointed_to_2);
560 target = composite_type (mv1, mv2);
561
562 /* For function types do not merge const qualifiers, but drop them
563 if used inconsistently. The middle-end uses these to mark const
564 and noreturn functions. */
565 if (TREE_CODE (pointed_to_1) == FUNCTION_TYPE)
566 target_quals = TYPE_QUALS (pointed_to_1) & TYPE_QUALS (pointed_to_2);
567 else
568 target_quals = TYPE_QUALS (pointed_to_1) | TYPE_QUALS (pointed_to_2);
569 t1 = build_pointer_type (c_build_qualified_type (target, target_quals));
570 return build_type_attribute_variant (t1, attributes);
571 }
572
573 /* Return the common type for two arithmetic types under the usual
574 arithmetic conversions. The default conversions have already been
575 applied, and enumerated types converted to their compatible integer
576 types. The resulting type is unqualified and has no attributes.
577
578 This is the type for the result of most arithmetic operations
579 if the operands have the given two types. */
580
581 static tree
582 c_common_type (tree t1, tree t2)
583 {
584 enum tree_code code1;
585 enum tree_code code2;
586
587 /* If one type is nonsense, use the other. */
588 if (t1 == error_mark_node)
589 return t2;
590 if (t2 == error_mark_node)
591 return t1;
592
593 if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED)
594 t1 = TYPE_MAIN_VARIANT (t1);
595
596 if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED)
597 t2 = TYPE_MAIN_VARIANT (t2);
598
599 if (TYPE_ATTRIBUTES (t1) != NULL_TREE)
600 t1 = build_type_attribute_variant (t1, NULL_TREE);
601
602 if (TYPE_ATTRIBUTES (t2) != NULL_TREE)
603 t2 = build_type_attribute_variant (t2, NULL_TREE);
604
605 /* Save time if the two types are the same. */
606
607 if (t1 == t2) return t1;
608
609 code1 = TREE_CODE (t1);
610 code2 = TREE_CODE (t2);
611
612 gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE
613 || code1 == FIXED_POINT_TYPE || code1 == REAL_TYPE
614 || code1 == INTEGER_TYPE);
615 gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE
616 || code2 == FIXED_POINT_TYPE || code2 == REAL_TYPE
617 || code2 == INTEGER_TYPE);
618
619 /* When one operand is a decimal float type, the other operand cannot be
620 a generic float type or a complex type. We also disallow vector types
621 here. */
622 if ((DECIMAL_FLOAT_TYPE_P (t1) || DECIMAL_FLOAT_TYPE_P (t2))
623 && !(DECIMAL_FLOAT_TYPE_P (t1) && DECIMAL_FLOAT_TYPE_P (t2)))
624 {
625 if (code1 == VECTOR_TYPE || code2 == VECTOR_TYPE)
626 {
627 error ("can%'t mix operands of decimal float and vector types");
628 return error_mark_node;
629 }
630 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
631 {
632 error ("can%'t mix operands of decimal float and complex types");
633 return error_mark_node;
634 }
635 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
636 {
637 error ("can%'t mix operands of decimal float and other float types");
638 return error_mark_node;
639 }
640 }
641
642 /* If one type is a vector type, return that type. (How the usual
643 arithmetic conversions apply to the vector types extension is not
644 precisely specified.) */
645 if (code1 == VECTOR_TYPE)
646 return t1;
647
648 if (code2 == VECTOR_TYPE)
649 return t2;
650
651 /* If one type is complex, form the common type of the non-complex
652 components, then make that complex. Use T1 or T2 if it is the
653 required type. */
654 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
655 {
656 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
657 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
658 tree subtype = c_common_type (subtype1, subtype2);
659
660 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
661 return t1;
662 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
663 return t2;
664 else
665 return build_complex_type (subtype);
666 }
667
668 /* If only one is real, use it as the result. */
669
670 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
671 return t1;
672
673 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
674 return t2;
675
676 /* If both are real and either are decimal floating point types, use
677 the decimal floating point type with the greater precision. */
678
679 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
680 {
681 if (TYPE_MAIN_VARIANT (t1) == dfloat128_type_node
682 || TYPE_MAIN_VARIANT (t2) == dfloat128_type_node)
683 return dfloat128_type_node;
684 else if (TYPE_MAIN_VARIANT (t1) == dfloat64_type_node
685 || TYPE_MAIN_VARIANT (t2) == dfloat64_type_node)
686 return dfloat64_type_node;
687 else if (TYPE_MAIN_VARIANT (t1) == dfloat32_type_node
688 || TYPE_MAIN_VARIANT (t2) == dfloat32_type_node)
689 return dfloat32_type_node;
690 }
691
692 /* Deal with fixed-point types. */
693 if (code1 == FIXED_POINT_TYPE || code2 == FIXED_POINT_TYPE)
694 {
695 unsigned int unsignedp = 0, satp = 0;
696 enum machine_mode m1, m2;
697 unsigned int fbit1, ibit1, fbit2, ibit2, max_fbit, max_ibit;
698
699 m1 = TYPE_MODE (t1);
700 m2 = TYPE_MODE (t2);
701
702 /* If one input type is saturating, the result type is saturating. */
703 if (TYPE_SATURATING (t1) || TYPE_SATURATING (t2))
704 satp = 1;
705
706 /* If both fixed-point types are unsigned, the result type is unsigned.
707 When mixing fixed-point and integer types, follow the sign of the
708 fixed-point type.
709 Otherwise, the result type is signed. */
710 if ((TYPE_UNSIGNED (t1) && TYPE_UNSIGNED (t2)
711 && code1 == FIXED_POINT_TYPE && code2 == FIXED_POINT_TYPE)
712 || (code1 == FIXED_POINT_TYPE && code2 != FIXED_POINT_TYPE
713 && TYPE_UNSIGNED (t1))
714 || (code1 != FIXED_POINT_TYPE && code2 == FIXED_POINT_TYPE
715 && TYPE_UNSIGNED (t2)))
716 unsignedp = 1;
717
718 /* The result type is signed. */
719 if (unsignedp == 0)
720 {
721 /* If the input type is unsigned, we need to convert to the
722 signed type. */
723 if (code1 == FIXED_POINT_TYPE && TYPE_UNSIGNED (t1))
724 {
725 enum mode_class mclass = (enum mode_class) 0;
726 if (GET_MODE_CLASS (m1) == MODE_UFRACT)
727 mclass = MODE_FRACT;
728 else if (GET_MODE_CLASS (m1) == MODE_UACCUM)
729 mclass = MODE_ACCUM;
730 else
731 gcc_unreachable ();
732 m1 = mode_for_size (GET_MODE_PRECISION (m1), mclass, 0);
733 }
734 if (code2 == FIXED_POINT_TYPE && TYPE_UNSIGNED (t2))
735 {
736 enum mode_class mclass = (enum mode_class) 0;
737 if (GET_MODE_CLASS (m2) == MODE_UFRACT)
738 mclass = MODE_FRACT;
739 else if (GET_MODE_CLASS (m2) == MODE_UACCUM)
740 mclass = MODE_ACCUM;
741 else
742 gcc_unreachable ();
743 m2 = mode_for_size (GET_MODE_PRECISION (m2), mclass, 0);
744 }
745 }
746
747 if (code1 == FIXED_POINT_TYPE)
748 {
749 fbit1 = GET_MODE_FBIT (m1);
750 ibit1 = GET_MODE_IBIT (m1);
751 }
752 else
753 {
754 fbit1 = 0;
755 /* Signed integers need to subtract one sign bit. */
756 ibit1 = TYPE_PRECISION (t1) - (!TYPE_UNSIGNED (t1));
757 }
758
759 if (code2 == FIXED_POINT_TYPE)
760 {
761 fbit2 = GET_MODE_FBIT (m2);
762 ibit2 = GET_MODE_IBIT (m2);
763 }
764 else
765 {
766 fbit2 = 0;
767 /* Signed integers need to subtract one sign bit. */
768 ibit2 = TYPE_PRECISION (t2) - (!TYPE_UNSIGNED (t2));
769 }
770
771 max_ibit = ibit1 >= ibit2 ? ibit1 : ibit2;
772 max_fbit = fbit1 >= fbit2 ? fbit1 : fbit2;
773 return c_common_fixed_point_type_for_size (max_ibit, max_fbit, unsignedp,
774 satp);
775 }
776
777 /* Both real or both integers; use the one with greater precision. */
778
779 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
780 return t1;
781 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
782 return t2;
783
784 /* Same precision. Prefer long longs to longs to ints when the
785 same precision, following the C99 rules on integer type rank
786 (which are equivalent to the C90 rules for C90 types). */
787
788 if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node
789 || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node)
790 return long_long_unsigned_type_node;
791
792 if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node
793 || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node)
794 {
795 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
796 return long_long_unsigned_type_node;
797 else
798 return long_long_integer_type_node;
799 }
800
801 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
802 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
803 return long_unsigned_type_node;
804
805 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
806 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
807 {
808 /* But preserve unsignedness from the other type,
809 since long cannot hold all the values of an unsigned int. */
810 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
811 return long_unsigned_type_node;
812 else
813 return long_integer_type_node;
814 }
815
816 /* Likewise, prefer long double to double even if same size. */
817 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
818 || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
819 return long_double_type_node;
820
821 /* Otherwise prefer the unsigned one. */
822
823 if (TYPE_UNSIGNED (t1))
824 return t1;
825 else
826 return t2;
827 }
828 \f
829 /* Wrapper around c_common_type that is used by c-common.c and other
830 front end optimizations that remove promotions. ENUMERAL_TYPEs
831 are allowed here and are converted to their compatible integer types.
832 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
833 preferably a non-Boolean type as the common type. */
834 tree
835 common_type (tree t1, tree t2)
836 {
837 if (TREE_CODE (t1) == ENUMERAL_TYPE)
838 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
839 if (TREE_CODE (t2) == ENUMERAL_TYPE)
840 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
841
842 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
843 if (TREE_CODE (t1) == BOOLEAN_TYPE
844 && TREE_CODE (t2) == BOOLEAN_TYPE)
845 return boolean_type_node;
846
847 /* If either type is BOOLEAN_TYPE, then return the other. */
848 if (TREE_CODE (t1) == BOOLEAN_TYPE)
849 return t2;
850 if (TREE_CODE (t2) == BOOLEAN_TYPE)
851 return t1;
852
853 return c_common_type (t1, t2);
854 }
855
856 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
857 or various other operations. Return 2 if they are compatible
858 but a warning may be needed if you use them together. */
859
860 int
861 comptypes (tree type1, tree type2)
862 {
863 const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base;
864 int val;
865
866 val = comptypes_internal (type1, type2);
867 free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1);
868
869 return val;
870 }
871 \f
872 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
873 or various other operations. Return 2 if they are compatible
874 but a warning may be needed if you use them together. This
875 differs from comptypes, in that we don't free the seen types. */
876
877 static int
878 comptypes_internal (const_tree type1, const_tree type2)
879 {
880 const_tree t1 = type1;
881 const_tree t2 = type2;
882 int attrval, val;
883
884 /* Suppress errors caused by previously reported errors. */
885
886 if (t1 == t2 || !t1 || !t2
887 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
888 return 1;
889
890 /* If either type is the internal version of sizetype, return the
891 language version. */
892 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
893 && TYPE_ORIG_SIZE_TYPE (t1))
894 t1 = TYPE_ORIG_SIZE_TYPE (t1);
895
896 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
897 && TYPE_ORIG_SIZE_TYPE (t2))
898 t2 = TYPE_ORIG_SIZE_TYPE (t2);
899
900
901 /* Enumerated types are compatible with integer types, but this is
902 not transitive: two enumerated types in the same translation unit
903 are compatible with each other only if they are the same type. */
904
905 if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE)
906 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1));
907 else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE)
908 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2));
909
910 if (t1 == t2)
911 return 1;
912
913 /* Different classes of types can't be compatible. */
914
915 if (TREE_CODE (t1) != TREE_CODE (t2))
916 return 0;
917
918 /* Qualifiers must match. C99 6.7.3p9 */
919
920 if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
921 return 0;
922
923 /* Allow for two different type nodes which have essentially the same
924 definition. Note that we already checked for equality of the type
925 qualifiers (just above). */
926
927 if (TREE_CODE (t1) != ARRAY_TYPE
928 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
929 return 1;
930
931 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
932 if (!(attrval = targetm.comp_type_attributes (t1, t2)))
933 return 0;
934
935 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
936 val = 0;
937
938 switch (TREE_CODE (t1))
939 {
940 case POINTER_TYPE:
941 /* Do not remove mode or aliasing information. */
942 if (TYPE_MODE (t1) != TYPE_MODE (t2)
943 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2))
944 break;
945 val = (TREE_TYPE (t1) == TREE_TYPE (t2)
946 ? 1 : comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2)));
947 break;
948
949 case FUNCTION_TYPE:
950 val = function_types_compatible_p (t1, t2);
951 break;
952
953 case ARRAY_TYPE:
954 {
955 tree d1 = TYPE_DOMAIN (t1);
956 tree d2 = TYPE_DOMAIN (t2);
957 bool d1_variable, d2_variable;
958 bool d1_zero, d2_zero;
959 val = 1;
960
961 /* Target types must match incl. qualifiers. */
962 if (TREE_TYPE (t1) != TREE_TYPE (t2)
963 && 0 == (val = comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2))))
964 return 0;
965
966 /* Sizes must match unless one is missing or variable. */
967 if (d1 == 0 || d2 == 0 || d1 == d2)
968 break;
969
970 d1_zero = !TYPE_MAX_VALUE (d1);
971 d2_zero = !TYPE_MAX_VALUE (d2);
972
973 d1_variable = (!d1_zero
974 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
975 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
976 d2_variable = (!d2_zero
977 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
978 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
979 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
980 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
981
982 if (d1_variable || d2_variable)
983 break;
984 if (d1_zero && d2_zero)
985 break;
986 if (d1_zero || d2_zero
987 || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
988 || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
989 val = 0;
990
991 break;
992 }
993
994 case ENUMERAL_TYPE:
995 case RECORD_TYPE:
996 case UNION_TYPE:
997 if (val != 1 && !same_translation_unit_p (t1, t2))
998 {
999 tree a1 = TYPE_ATTRIBUTES (t1);
1000 tree a2 = TYPE_ATTRIBUTES (t2);
1001
1002 if (! attribute_list_contained (a1, a2)
1003 && ! attribute_list_contained (a2, a1))
1004 break;
1005
1006 if (attrval != 2)
1007 return tagged_types_tu_compatible_p (t1, t2);
1008 val = tagged_types_tu_compatible_p (t1, t2);
1009 }
1010 break;
1011
1012 case VECTOR_TYPE:
1013 val = TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
1014 && comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2));
1015 break;
1016
1017 default:
1018 break;
1019 }
1020 return attrval == 2 && val == 1 ? 2 : val;
1021 }
1022
1023 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
1024 ignoring their qualifiers. */
1025
1026 static int
1027 comp_target_types (tree ttl, tree ttr)
1028 {
1029 int val;
1030 tree mvl, mvr;
1031
1032 /* Do not lose qualifiers on element types of array types that are
1033 pointer targets by taking their TYPE_MAIN_VARIANT. */
1034 mvl = TREE_TYPE (ttl);
1035 mvr = TREE_TYPE (ttr);
1036 if (TREE_CODE (mvl) != ARRAY_TYPE)
1037 mvl = TYPE_MAIN_VARIANT (mvl);
1038 if (TREE_CODE (mvr) != ARRAY_TYPE)
1039 mvr = TYPE_MAIN_VARIANT (mvr);
1040 val = comptypes (mvl, mvr);
1041
1042 if (val == 2)
1043 pedwarn (input_location, OPT_pedantic, "types are not quite compatible");
1044 return val;
1045 }
1046 \f
1047 /* Subroutines of `comptypes'. */
1048
1049 /* Determine whether two trees derive from the same translation unit.
1050 If the CONTEXT chain ends in a null, that tree's context is still
1051 being parsed, so if two trees have context chains ending in null,
1052 they're in the same translation unit. */
1053 int
1054 same_translation_unit_p (const_tree t1, const_tree t2)
1055 {
1056 while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL)
1057 switch (TREE_CODE_CLASS (TREE_CODE (t1)))
1058 {
1059 case tcc_declaration:
1060 t1 = DECL_CONTEXT (t1); break;
1061 case tcc_type:
1062 t1 = TYPE_CONTEXT (t1); break;
1063 case tcc_exceptional:
1064 t1 = BLOCK_SUPERCONTEXT (t1); break; /* assume block */
1065 default: gcc_unreachable ();
1066 }
1067
1068 while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL)
1069 switch (TREE_CODE_CLASS (TREE_CODE (t2)))
1070 {
1071 case tcc_declaration:
1072 t2 = DECL_CONTEXT (t2); break;
1073 case tcc_type:
1074 t2 = TYPE_CONTEXT (t2); break;
1075 case tcc_exceptional:
1076 t2 = BLOCK_SUPERCONTEXT (t2); break; /* assume block */
1077 default: gcc_unreachable ();
1078 }
1079
1080 return t1 == t2;
1081 }
1082
1083 /* Allocate the seen two types, assuming that they are compatible. */
1084
1085 static struct tagged_tu_seen_cache *
1086 alloc_tagged_tu_seen_cache (const_tree t1, const_tree t2)
1087 {
1088 struct tagged_tu_seen_cache *tu = XNEW (struct tagged_tu_seen_cache);
1089 tu->next = tagged_tu_seen_base;
1090 tu->t1 = t1;
1091 tu->t2 = t2;
1092
1093 tagged_tu_seen_base = tu;
1094
1095 /* The C standard says that two structures in different translation
1096 units are compatible with each other only if the types of their
1097 fields are compatible (among other things). We assume that they
1098 are compatible until proven otherwise when building the cache.
1099 An example where this can occur is:
1100 struct a
1101 {
1102 struct a *next;
1103 };
1104 If we are comparing this against a similar struct in another TU,
1105 and did not assume they were compatible, we end up with an infinite
1106 loop. */
1107 tu->val = 1;
1108 return tu;
1109 }
1110
1111 /* Free the seen types until we get to TU_TIL. */
1112
1113 static void
1114 free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *tu_til)
1115 {
1116 const struct tagged_tu_seen_cache *tu = tagged_tu_seen_base;
1117 while (tu != tu_til)
1118 {
1119 const struct tagged_tu_seen_cache *const tu1
1120 = (const struct tagged_tu_seen_cache *) tu;
1121 tu = tu1->next;
1122 free (CONST_CAST (struct tagged_tu_seen_cache *, tu1));
1123 }
1124 tagged_tu_seen_base = tu_til;
1125 }
1126
1127 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1128 compatible. If the two types are not the same (which has been
1129 checked earlier), this can only happen when multiple translation
1130 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1131 rules. */
1132
1133 static int
1134 tagged_types_tu_compatible_p (const_tree t1, const_tree t2)
1135 {
1136 tree s1, s2;
1137 bool needs_warning = false;
1138
1139 /* We have to verify that the tags of the types are the same. This
1140 is harder than it looks because this may be a typedef, so we have
1141 to go look at the original type. It may even be a typedef of a
1142 typedef...
1143 In the case of compiler-created builtin structs the TYPE_DECL
1144 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1145 while (TYPE_NAME (t1)
1146 && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL
1147 && DECL_ORIGINAL_TYPE (TYPE_NAME (t1)))
1148 t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1));
1149
1150 while (TYPE_NAME (t2)
1151 && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL
1152 && DECL_ORIGINAL_TYPE (TYPE_NAME (t2)))
1153 t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2));
1154
1155 /* C90 didn't have the requirement that the two tags be the same. */
1156 if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2))
1157 return 0;
1158
1159 /* C90 didn't say what happened if one or both of the types were
1160 incomplete; we choose to follow C99 rules here, which is that they
1161 are compatible. */
1162 if (TYPE_SIZE (t1) == NULL
1163 || TYPE_SIZE (t2) == NULL)
1164 return 1;
1165
1166 {
1167 const struct tagged_tu_seen_cache * tts_i;
1168 for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next)
1169 if (tts_i->t1 == t1 && tts_i->t2 == t2)
1170 return tts_i->val;
1171 }
1172
1173 switch (TREE_CODE (t1))
1174 {
1175 case ENUMERAL_TYPE:
1176 {
1177 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1178 /* Speed up the case where the type values are in the same order. */
1179 tree tv1 = TYPE_VALUES (t1);
1180 tree tv2 = TYPE_VALUES (t2);
1181
1182 if (tv1 == tv2)
1183 {
1184 return 1;
1185 }
1186
1187 for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2))
1188 {
1189 if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2))
1190 break;
1191 if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1)
1192 {
1193 tu->val = 0;
1194 return 0;
1195 }
1196 }
1197
1198 if (tv1 == NULL_TREE && tv2 == NULL_TREE)
1199 {
1200 return 1;
1201 }
1202 if (tv1 == NULL_TREE || tv2 == NULL_TREE)
1203 {
1204 tu->val = 0;
1205 return 0;
1206 }
1207
1208 if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2)))
1209 {
1210 tu->val = 0;
1211 return 0;
1212 }
1213
1214 for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1))
1215 {
1216 s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2));
1217 if (s2 == NULL
1218 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1)
1219 {
1220 tu->val = 0;
1221 return 0;
1222 }
1223 }
1224 return 1;
1225 }
1226
1227 case UNION_TYPE:
1228 {
1229 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1230 if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2)))
1231 {
1232 tu->val = 0;
1233 return 0;
1234 }
1235
1236 /* Speed up the common case where the fields are in the same order. */
1237 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2;
1238 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1239 {
1240 int result;
1241
1242 if (DECL_NAME (s1) != DECL_NAME (s2))
1243 break;
1244 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1245
1246 if (result != 1 && !DECL_NAME (s1))
1247 break;
1248 if (result == 0)
1249 {
1250 tu->val = 0;
1251 return 0;
1252 }
1253 if (result == 2)
1254 needs_warning = true;
1255
1256 if (TREE_CODE (s1) == FIELD_DECL
1257 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1258 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1259 {
1260 tu->val = 0;
1261 return 0;
1262 }
1263 }
1264 if (!s1 && !s2)
1265 {
1266 tu->val = needs_warning ? 2 : 1;
1267 return tu->val;
1268 }
1269
1270 for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1))
1271 {
1272 bool ok = false;
1273
1274 for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2))
1275 if (DECL_NAME (s1) == DECL_NAME (s2))
1276 {
1277 int result;
1278
1279 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1280
1281 if (result != 1 && !DECL_NAME (s1))
1282 continue;
1283 if (result == 0)
1284 {
1285 tu->val = 0;
1286 return 0;
1287 }
1288 if (result == 2)
1289 needs_warning = true;
1290
1291 if (TREE_CODE (s1) == FIELD_DECL
1292 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1293 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1294 break;
1295
1296 ok = true;
1297 break;
1298 }
1299 if (!ok)
1300 {
1301 tu->val = 0;
1302 return 0;
1303 }
1304 }
1305 tu->val = needs_warning ? 2 : 10;
1306 return tu->val;
1307 }
1308
1309 case RECORD_TYPE:
1310 {
1311 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1312
1313 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2);
1314 s1 && s2;
1315 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1316 {
1317 int result;
1318 if (TREE_CODE (s1) != TREE_CODE (s2)
1319 || DECL_NAME (s1) != DECL_NAME (s2))
1320 break;
1321 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1322 if (result == 0)
1323 break;
1324 if (result == 2)
1325 needs_warning = true;
1326
1327 if (TREE_CODE (s1) == FIELD_DECL
1328 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1329 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1330 break;
1331 }
1332 if (s1 && s2)
1333 tu->val = 0;
1334 else
1335 tu->val = needs_warning ? 2 : 1;
1336 return tu->val;
1337 }
1338
1339 default:
1340 gcc_unreachable ();
1341 }
1342 }
1343
1344 /* Return 1 if two function types F1 and F2 are compatible.
1345 If either type specifies no argument types,
1346 the other must specify a fixed number of self-promoting arg types.
1347 Otherwise, if one type specifies only the number of arguments,
1348 the other must specify that number of self-promoting arg types.
1349 Otherwise, the argument types must match. */
1350
1351 static int
1352 function_types_compatible_p (const_tree f1, const_tree f2)
1353 {
1354 tree args1, args2;
1355 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1356 int val = 1;
1357 int val1;
1358 tree ret1, ret2;
1359
1360 ret1 = TREE_TYPE (f1);
1361 ret2 = TREE_TYPE (f2);
1362
1363 /* 'volatile' qualifiers on a function's return type used to mean
1364 the function is noreturn. */
1365 if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2))
1366 pedwarn (input_location, 0, "function return types not compatible due to %<volatile%>");
1367 if (TYPE_VOLATILE (ret1))
1368 ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1),
1369 TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE);
1370 if (TYPE_VOLATILE (ret2))
1371 ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2),
1372 TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE);
1373 val = comptypes_internal (ret1, ret2);
1374 if (val == 0)
1375 return 0;
1376
1377 args1 = TYPE_ARG_TYPES (f1);
1378 args2 = TYPE_ARG_TYPES (f2);
1379
1380 /* An unspecified parmlist matches any specified parmlist
1381 whose argument types don't need default promotions. */
1382
1383 if (args1 == 0)
1384 {
1385 if (!self_promoting_args_p (args2))
1386 return 0;
1387 /* If one of these types comes from a non-prototype fn definition,
1388 compare that with the other type's arglist.
1389 If they don't match, ask for a warning (but no error). */
1390 if (TYPE_ACTUAL_ARG_TYPES (f1)
1391 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
1392 val = 2;
1393 return val;
1394 }
1395 if (args2 == 0)
1396 {
1397 if (!self_promoting_args_p (args1))
1398 return 0;
1399 if (TYPE_ACTUAL_ARG_TYPES (f2)
1400 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
1401 val = 2;
1402 return val;
1403 }
1404
1405 /* Both types have argument lists: compare them and propagate results. */
1406 val1 = type_lists_compatible_p (args1, args2);
1407 return val1 != 1 ? val1 : val;
1408 }
1409
1410 /* Check two lists of types for compatibility,
1411 returning 0 for incompatible, 1 for compatible,
1412 or 2 for compatible with warning. */
1413
1414 static int
1415 type_lists_compatible_p (const_tree args1, const_tree args2)
1416 {
1417 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1418 int val = 1;
1419 int newval = 0;
1420
1421 while (1)
1422 {
1423 tree a1, mv1, a2, mv2;
1424 if (args1 == 0 && args2 == 0)
1425 return val;
1426 /* If one list is shorter than the other,
1427 they fail to match. */
1428 if (args1 == 0 || args2 == 0)
1429 return 0;
1430 mv1 = a1 = TREE_VALUE (args1);
1431 mv2 = a2 = TREE_VALUE (args2);
1432 if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE)
1433 mv1 = TYPE_MAIN_VARIANT (mv1);
1434 if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE)
1435 mv2 = TYPE_MAIN_VARIANT (mv2);
1436 /* A null pointer instead of a type
1437 means there is supposed to be an argument
1438 but nothing is specified about what type it has.
1439 So match anything that self-promotes. */
1440 if (a1 == 0)
1441 {
1442 if (c_type_promotes_to (a2) != a2)
1443 return 0;
1444 }
1445 else if (a2 == 0)
1446 {
1447 if (c_type_promotes_to (a1) != a1)
1448 return 0;
1449 }
1450 /* If one of the lists has an error marker, ignore this arg. */
1451 else if (TREE_CODE (a1) == ERROR_MARK
1452 || TREE_CODE (a2) == ERROR_MARK)
1453 ;
1454 else if (!(newval = comptypes_internal (mv1, mv2)))
1455 {
1456 /* Allow wait (union {union wait *u; int *i} *)
1457 and wait (union wait *) to be compatible. */
1458 if (TREE_CODE (a1) == UNION_TYPE
1459 && (TYPE_NAME (a1) == 0
1460 || TYPE_TRANSPARENT_UNION (a1))
1461 && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST
1462 && tree_int_cst_equal (TYPE_SIZE (a1),
1463 TYPE_SIZE (a2)))
1464 {
1465 tree memb;
1466 for (memb = TYPE_FIELDS (a1);
1467 memb; memb = TREE_CHAIN (memb))
1468 {
1469 tree mv3 = TREE_TYPE (memb);
1470 if (mv3 && mv3 != error_mark_node
1471 && TREE_CODE (mv3) != ARRAY_TYPE)
1472 mv3 = TYPE_MAIN_VARIANT (mv3);
1473 if (comptypes_internal (mv3, mv2))
1474 break;
1475 }
1476 if (memb == 0)
1477 return 0;
1478 }
1479 else if (TREE_CODE (a2) == UNION_TYPE
1480 && (TYPE_NAME (a2) == 0
1481 || TYPE_TRANSPARENT_UNION (a2))
1482 && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST
1483 && tree_int_cst_equal (TYPE_SIZE (a2),
1484 TYPE_SIZE (a1)))
1485 {
1486 tree memb;
1487 for (memb = TYPE_FIELDS (a2);
1488 memb; memb = TREE_CHAIN (memb))
1489 {
1490 tree mv3 = TREE_TYPE (memb);
1491 if (mv3 && mv3 != error_mark_node
1492 && TREE_CODE (mv3) != ARRAY_TYPE)
1493 mv3 = TYPE_MAIN_VARIANT (mv3);
1494 if (comptypes_internal (mv3, mv1))
1495 break;
1496 }
1497 if (memb == 0)
1498 return 0;
1499 }
1500 else
1501 return 0;
1502 }
1503
1504 /* comptypes said ok, but record if it said to warn. */
1505 if (newval > val)
1506 val = newval;
1507
1508 args1 = TREE_CHAIN (args1);
1509 args2 = TREE_CHAIN (args2);
1510 }
1511 }
1512 \f
1513 /* Compute the size to increment a pointer by. */
1514
1515 static tree
1516 c_size_in_bytes (const_tree type)
1517 {
1518 enum tree_code code = TREE_CODE (type);
1519
1520 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
1521 return size_one_node;
1522
1523 if (!COMPLETE_OR_VOID_TYPE_P (type))
1524 {
1525 error ("arithmetic on pointer to an incomplete type");
1526 return size_one_node;
1527 }
1528
1529 /* Convert in case a char is more than one unit. */
1530 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
1531 size_int (TYPE_PRECISION (char_type_node)
1532 / BITS_PER_UNIT));
1533 }
1534 \f
1535 /* Return either DECL or its known constant value (if it has one). */
1536
1537 tree
1538 decl_constant_value (tree decl)
1539 {
1540 if (/* Don't change a variable array bound or initial value to a constant
1541 in a place where a variable is invalid. Note that DECL_INITIAL
1542 isn't valid for a PARM_DECL. */
1543 current_function_decl != 0
1544 && TREE_CODE (decl) != PARM_DECL
1545 && !TREE_THIS_VOLATILE (decl)
1546 && TREE_READONLY (decl)
1547 && DECL_INITIAL (decl) != 0
1548 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
1549 /* This is invalid if initial value is not constant.
1550 If it has either a function call, a memory reference,
1551 or a variable, then re-evaluating it could give different results. */
1552 && TREE_CONSTANT (DECL_INITIAL (decl))
1553 /* Check for cases where this is sub-optimal, even though valid. */
1554 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
1555 return DECL_INITIAL (decl);
1556 return decl;
1557 }
1558
1559 /* Return either DECL or its known constant value (if it has one), but
1560 return DECL if pedantic or DECL has mode BLKmode. This is for
1561 bug-compatibility with the old behavior of decl_constant_value
1562 (before GCC 3.0); every use of this function is a bug and it should
1563 be removed before GCC 3.1. It is not appropriate to use pedantic
1564 in a way that affects optimization, and BLKmode is probably not the
1565 right test for avoiding misoptimizations either. */
1566
1567 static tree
1568 decl_constant_value_for_broken_optimization (tree decl)
1569 {
1570 tree ret;
1571
1572 if (pedantic || DECL_MODE (decl) == BLKmode)
1573 return decl;
1574
1575 ret = decl_constant_value (decl);
1576 /* Avoid unwanted tree sharing between the initializer and current
1577 function's body where the tree can be modified e.g. by the
1578 gimplifier. */
1579 if (ret != decl && TREE_STATIC (decl))
1580 ret = unshare_expr (ret);
1581 return ret;
1582 }
1583
1584 /* Convert the array expression EXP to a pointer. */
1585 static tree
1586 array_to_pointer_conversion (tree exp)
1587 {
1588 tree orig_exp = exp;
1589 tree type = TREE_TYPE (exp);
1590 tree adr;
1591 tree restype = TREE_TYPE (type);
1592 tree ptrtype;
1593
1594 gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
1595
1596 STRIP_TYPE_NOPS (exp);
1597
1598 if (TREE_NO_WARNING (orig_exp))
1599 TREE_NO_WARNING (exp) = 1;
1600
1601 ptrtype = build_pointer_type (restype);
1602
1603 if (TREE_CODE (exp) == INDIRECT_REF)
1604 return convert (ptrtype, TREE_OPERAND (exp, 0));
1605
1606 if (TREE_CODE (exp) == VAR_DECL)
1607 {
1608 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1609 ADDR_EXPR because it's the best way of representing what
1610 happens in C when we take the address of an array and place
1611 it in a pointer to the element type. */
1612 adr = build1 (ADDR_EXPR, ptrtype, exp);
1613 if (!c_mark_addressable (exp))
1614 return error_mark_node;
1615 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
1616 return adr;
1617 }
1618
1619 /* This way is better for a COMPONENT_REF since it can
1620 simplify the offset for a component. */
1621 adr = build_unary_op (ADDR_EXPR, exp, 1);
1622 return convert (ptrtype, adr);
1623 }
1624
1625 /* Convert the function expression EXP to a pointer. */
1626 static tree
1627 function_to_pointer_conversion (tree exp)
1628 {
1629 tree orig_exp = exp;
1630
1631 gcc_assert (TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE);
1632
1633 STRIP_TYPE_NOPS (exp);
1634
1635 if (TREE_NO_WARNING (orig_exp))
1636 TREE_NO_WARNING (exp) = 1;
1637
1638 return build_unary_op (ADDR_EXPR, exp, 0);
1639 }
1640
1641 /* Perform the default conversion of arrays and functions to pointers.
1642 Return the result of converting EXP. For any other expression, just
1643 return EXP after removing NOPs. */
1644
1645 struct c_expr
1646 default_function_array_conversion (struct c_expr exp)
1647 {
1648 tree orig_exp = exp.value;
1649 tree type = TREE_TYPE (exp.value);
1650 enum tree_code code = TREE_CODE (type);
1651
1652 switch (code)
1653 {
1654 case ARRAY_TYPE:
1655 {
1656 bool not_lvalue = false;
1657 bool lvalue_array_p;
1658
1659 while ((TREE_CODE (exp.value) == NON_LVALUE_EXPR
1660 || CONVERT_EXPR_P (exp.value))
1661 && TREE_TYPE (TREE_OPERAND (exp.value, 0)) == type)
1662 {
1663 if (TREE_CODE (exp.value) == NON_LVALUE_EXPR)
1664 not_lvalue = true;
1665 exp.value = TREE_OPERAND (exp.value, 0);
1666 }
1667
1668 if (TREE_NO_WARNING (orig_exp))
1669 TREE_NO_WARNING (exp.value) = 1;
1670
1671 lvalue_array_p = !not_lvalue && lvalue_p (exp.value);
1672 if (!flag_isoc99 && !lvalue_array_p)
1673 {
1674 /* Before C99, non-lvalue arrays do not decay to pointers.
1675 Normally, using such an array would be invalid; but it can
1676 be used correctly inside sizeof or as a statement expression.
1677 Thus, do not give an error here; an error will result later. */
1678 return exp;
1679 }
1680
1681 exp.value = array_to_pointer_conversion (exp.value);
1682 }
1683 break;
1684 case FUNCTION_TYPE:
1685 exp.value = function_to_pointer_conversion (exp.value);
1686 break;
1687 default:
1688 STRIP_TYPE_NOPS (exp.value);
1689 if (TREE_NO_WARNING (orig_exp))
1690 TREE_NO_WARNING (exp.value) = 1;
1691 break;
1692 }
1693
1694 return exp;
1695 }
1696
1697
1698 /* EXP is an expression of integer type. Apply the integer promotions
1699 to it and return the promoted value. */
1700
1701 tree
1702 perform_integral_promotions (tree exp)
1703 {
1704 tree type = TREE_TYPE (exp);
1705 enum tree_code code = TREE_CODE (type);
1706
1707 gcc_assert (INTEGRAL_TYPE_P (type));
1708
1709 /* Normally convert enums to int,
1710 but convert wide enums to something wider. */
1711 if (code == ENUMERAL_TYPE)
1712 {
1713 type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
1714 TYPE_PRECISION (integer_type_node)),
1715 ((TYPE_PRECISION (type)
1716 >= TYPE_PRECISION (integer_type_node))
1717 && TYPE_UNSIGNED (type)));
1718
1719 return convert (type, exp);
1720 }
1721
1722 /* ??? This should no longer be needed now bit-fields have their
1723 proper types. */
1724 if (TREE_CODE (exp) == COMPONENT_REF
1725 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
1726 /* If it's thinner than an int, promote it like a
1727 c_promoting_integer_type_p, otherwise leave it alone. */
1728 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
1729 TYPE_PRECISION (integer_type_node)))
1730 return convert (integer_type_node, exp);
1731
1732 if (c_promoting_integer_type_p (type))
1733 {
1734 /* Preserve unsignedness if not really getting any wider. */
1735 if (TYPE_UNSIGNED (type)
1736 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
1737 return convert (unsigned_type_node, exp);
1738
1739 return convert (integer_type_node, exp);
1740 }
1741
1742 return exp;
1743 }
1744
1745
1746 /* Perform default promotions for C data used in expressions.
1747 Enumeral types or short or char are converted to int.
1748 In addition, manifest constants symbols are replaced by their values. */
1749
1750 tree
1751 default_conversion (tree exp)
1752 {
1753 tree orig_exp;
1754 tree type = TREE_TYPE (exp);
1755 enum tree_code code = TREE_CODE (type);
1756
1757 /* Functions and arrays have been converted during parsing. */
1758 gcc_assert (code != FUNCTION_TYPE);
1759 if (code == ARRAY_TYPE)
1760 return exp;
1761
1762 /* Constants can be used directly unless they're not loadable. */
1763 if (TREE_CODE (exp) == CONST_DECL)
1764 exp = DECL_INITIAL (exp);
1765
1766 /* Replace a nonvolatile const static variable with its value unless
1767 it is an array, in which case we must be sure that taking the
1768 address of the array produces consistent results. */
1769 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE)
1770 {
1771 exp = decl_constant_value_for_broken_optimization (exp);
1772 type = TREE_TYPE (exp);
1773 }
1774
1775 /* Strip no-op conversions. */
1776 orig_exp = exp;
1777 STRIP_TYPE_NOPS (exp);
1778
1779 if (TREE_NO_WARNING (orig_exp))
1780 TREE_NO_WARNING (exp) = 1;
1781
1782 if (code == VOID_TYPE)
1783 {
1784 error ("void value not ignored as it ought to be");
1785 return error_mark_node;
1786 }
1787
1788 exp = require_complete_type (exp);
1789 if (exp == error_mark_node)
1790 return error_mark_node;
1791
1792 if (INTEGRAL_TYPE_P (type))
1793 return perform_integral_promotions (exp);
1794
1795 return exp;
1796 }
1797 \f
1798 /* Look up COMPONENT in a structure or union DECL.
1799
1800 If the component name is not found, returns NULL_TREE. Otherwise,
1801 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1802 stepping down the chain to the component, which is in the last
1803 TREE_VALUE of the list. Normally the list is of length one, but if
1804 the component is embedded within (nested) anonymous structures or
1805 unions, the list steps down the chain to the component. */
1806
1807 static tree
1808 lookup_field (tree decl, tree component)
1809 {
1810 tree type = TREE_TYPE (decl);
1811 tree field;
1812
1813 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1814 to the field elements. Use a binary search on this array to quickly
1815 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1816 will always be set for structures which have many elements. */
1817
1818 if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s)
1819 {
1820 int bot, top, half;
1821 tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0];
1822
1823 field = TYPE_FIELDS (type);
1824 bot = 0;
1825 top = TYPE_LANG_SPECIFIC (type)->s->len;
1826 while (top - bot > 1)
1827 {
1828 half = (top - bot + 1) >> 1;
1829 field = field_array[bot+half];
1830
1831 if (DECL_NAME (field) == NULL_TREE)
1832 {
1833 /* Step through all anon unions in linear fashion. */
1834 while (DECL_NAME (field_array[bot]) == NULL_TREE)
1835 {
1836 field = field_array[bot++];
1837 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1838 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1839 {
1840 tree anon = lookup_field (field, component);
1841
1842 if (anon)
1843 return tree_cons (NULL_TREE, field, anon);
1844 }
1845 }
1846
1847 /* Entire record is only anon unions. */
1848 if (bot > top)
1849 return NULL_TREE;
1850
1851 /* Restart the binary search, with new lower bound. */
1852 continue;
1853 }
1854
1855 if (DECL_NAME (field) == component)
1856 break;
1857 if (DECL_NAME (field) < component)
1858 bot += half;
1859 else
1860 top = bot + half;
1861 }
1862
1863 if (DECL_NAME (field_array[bot]) == component)
1864 field = field_array[bot];
1865 else if (DECL_NAME (field) != component)
1866 return NULL_TREE;
1867 }
1868 else
1869 {
1870 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1871 {
1872 if (DECL_NAME (field) == NULL_TREE
1873 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1874 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
1875 {
1876 tree anon = lookup_field (field, component);
1877
1878 if (anon)
1879 return tree_cons (NULL_TREE, field, anon);
1880 }
1881
1882 if (DECL_NAME (field) == component)
1883 break;
1884 }
1885
1886 if (field == NULL_TREE)
1887 return NULL_TREE;
1888 }
1889
1890 return tree_cons (NULL_TREE, field, NULL_TREE);
1891 }
1892
1893 /* Make an expression to refer to the COMPONENT field of
1894 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1895
1896 tree
1897 build_component_ref (tree datum, tree component)
1898 {
1899 tree type = TREE_TYPE (datum);
1900 enum tree_code code = TREE_CODE (type);
1901 tree field = NULL;
1902 tree ref;
1903
1904 if (!objc_is_public (datum, component))
1905 return error_mark_node;
1906
1907 /* See if there is a field or component with name COMPONENT. */
1908
1909 if (code == RECORD_TYPE || code == UNION_TYPE)
1910 {
1911 if (!COMPLETE_TYPE_P (type))
1912 {
1913 c_incomplete_type_error (NULL_TREE, type);
1914 return error_mark_node;
1915 }
1916
1917 field = lookup_field (datum, component);
1918
1919 if (!field)
1920 {
1921 error ("%qT has no member named %qE", type, component);
1922 return error_mark_node;
1923 }
1924
1925 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1926 This might be better solved in future the way the C++ front
1927 end does it - by giving the anonymous entities each a
1928 separate name and type, and then have build_component_ref
1929 recursively call itself. We can't do that here. */
1930 do
1931 {
1932 tree subdatum = TREE_VALUE (field);
1933 int quals;
1934 tree subtype;
1935
1936 if (TREE_TYPE (subdatum) == error_mark_node)
1937 return error_mark_node;
1938
1939 quals = TYPE_QUALS (strip_array_types (TREE_TYPE (subdatum)));
1940 quals |= TYPE_QUALS (TREE_TYPE (datum));
1941 subtype = c_build_qualified_type (TREE_TYPE (subdatum), quals);
1942
1943 ref = build3 (COMPONENT_REF, subtype, datum, subdatum,
1944 NULL_TREE);
1945 if (TREE_READONLY (datum) || TREE_READONLY (subdatum))
1946 TREE_READONLY (ref) = 1;
1947 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
1948 TREE_THIS_VOLATILE (ref) = 1;
1949
1950 if (TREE_DEPRECATED (subdatum))
1951 warn_deprecated_use (subdatum);
1952
1953 datum = ref;
1954
1955 field = TREE_CHAIN (field);
1956 }
1957 while (field);
1958
1959 return ref;
1960 }
1961 else if (code != ERROR_MARK)
1962 error ("request for member %qE in something not a structure or union",
1963 component);
1964
1965 return error_mark_node;
1966 }
1967 \f
1968 /* Given an expression PTR for a pointer, return an expression
1969 for the value pointed to.
1970 ERRORSTRING is the name of the operator to appear in error messages. */
1971
1972 tree
1973 build_indirect_ref (tree ptr, const char *errorstring)
1974 {
1975 tree pointer = default_conversion (ptr);
1976 tree type = TREE_TYPE (pointer);
1977
1978 if (TREE_CODE (type) == POINTER_TYPE)
1979 {
1980 if (CONVERT_EXPR_P (pointer)
1981 || TREE_CODE (pointer) == VIEW_CONVERT_EXPR)
1982 {
1983 /* If a warning is issued, mark it to avoid duplicates from
1984 the backend. This only needs to be done at
1985 warn_strict_aliasing > 2. */
1986 if (warn_strict_aliasing > 2)
1987 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (pointer, 0)),
1988 type, TREE_OPERAND (pointer, 0)))
1989 TREE_NO_WARNING (pointer) = 1;
1990 }
1991
1992 if (TREE_CODE (pointer) == ADDR_EXPR
1993 && (TREE_TYPE (TREE_OPERAND (pointer, 0))
1994 == TREE_TYPE (type)))
1995 return TREE_OPERAND (pointer, 0);
1996 else
1997 {
1998 tree t = TREE_TYPE (type);
1999 tree ref;
2000
2001 ref = build1 (INDIRECT_REF, t, pointer);
2002
2003 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
2004 {
2005 error ("dereferencing pointer to incomplete type");
2006 return error_mark_node;
2007 }
2008 if (VOID_TYPE_P (t) && skip_evaluation == 0)
2009 warning (0, "dereferencing %<void *%> pointer");
2010
2011 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
2012 so that we get the proper error message if the result is used
2013 to assign to. Also, &* is supposed to be a no-op.
2014 And ANSI C seems to specify that the type of the result
2015 should be the const type. */
2016 /* A de-reference of a pointer to const is not a const. It is valid
2017 to change it via some other pointer. */
2018 TREE_READONLY (ref) = TYPE_READONLY (t);
2019 TREE_SIDE_EFFECTS (ref)
2020 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
2021 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
2022 return ref;
2023 }
2024 }
2025 else if (TREE_CODE (pointer) != ERROR_MARK)
2026 error ("invalid type argument of %qs (have %qT)", errorstring, type);
2027 return error_mark_node;
2028 }
2029
2030 /* This handles expressions of the form "a[i]", which denotes
2031 an array reference.
2032
2033 This is logically equivalent in C to *(a+i), but we may do it differently.
2034 If A is a variable or a member, we generate a primitive ARRAY_REF.
2035 This avoids forcing the array out of registers, and can work on
2036 arrays that are not lvalues (for example, members of structures returned
2037 by functions). */
2038
2039 tree
2040 build_array_ref (tree array, tree index)
2041 {
2042 bool swapped = false;
2043 if (TREE_TYPE (array) == error_mark_node
2044 || TREE_TYPE (index) == error_mark_node)
2045 return error_mark_node;
2046
2047 if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE
2048 && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE)
2049 {
2050 tree temp;
2051 if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE
2052 && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE)
2053 {
2054 error ("subscripted value is neither array nor pointer");
2055 return error_mark_node;
2056 }
2057 temp = array;
2058 array = index;
2059 index = temp;
2060 swapped = true;
2061 }
2062
2063 if (!INTEGRAL_TYPE_P (TREE_TYPE (index)))
2064 {
2065 error ("array subscript is not an integer");
2066 return error_mark_node;
2067 }
2068
2069 if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE)
2070 {
2071 error ("subscripted value is pointer to function");
2072 return error_mark_node;
2073 }
2074
2075 /* ??? Existing practice has been to warn only when the char
2076 index is syntactically the index, not for char[array]. */
2077 if (!swapped)
2078 warn_array_subscript_with_type_char (index);
2079
2080 /* Apply default promotions *after* noticing character types. */
2081 index = default_conversion (index);
2082
2083 gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
2084
2085 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
2086 {
2087 tree rval, type;
2088
2089 /* An array that is indexed by a non-constant
2090 cannot be stored in a register; we must be able to do
2091 address arithmetic on its address.
2092 Likewise an array of elements of variable size. */
2093 if (TREE_CODE (index) != INTEGER_CST
2094 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
2095 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
2096 {
2097 if (!c_mark_addressable (array))
2098 return error_mark_node;
2099 }
2100 /* An array that is indexed by a constant value which is not within
2101 the array bounds cannot be stored in a register either; because we
2102 would get a crash in store_bit_field/extract_bit_field when trying
2103 to access a non-existent part of the register. */
2104 if (TREE_CODE (index) == INTEGER_CST
2105 && TYPE_DOMAIN (TREE_TYPE (array))
2106 && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array))))
2107 {
2108 if (!c_mark_addressable (array))
2109 return error_mark_node;
2110 }
2111
2112 if (pedantic)
2113 {
2114 tree foo = array;
2115 while (TREE_CODE (foo) == COMPONENT_REF)
2116 foo = TREE_OPERAND (foo, 0);
2117 if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
2118 pedwarn (input_location, OPT_pedantic,
2119 "ISO C forbids subscripting %<register%> array");
2120 else if (!flag_isoc99 && !lvalue_p (foo))
2121 pedwarn (input_location, OPT_pedantic,
2122 "ISO C90 forbids subscripting non-lvalue array");
2123 }
2124
2125 type = TREE_TYPE (TREE_TYPE (array));
2126 rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE);
2127 /* Array ref is const/volatile if the array elements are
2128 or if the array is. */
2129 TREE_READONLY (rval)
2130 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
2131 | TREE_READONLY (array));
2132 TREE_SIDE_EFFECTS (rval)
2133 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2134 | TREE_SIDE_EFFECTS (array));
2135 TREE_THIS_VOLATILE (rval)
2136 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2137 /* This was added by rms on 16 Nov 91.
2138 It fixes vol struct foo *a; a->elts[1]
2139 in an inline function.
2140 Hope it doesn't break something else. */
2141 | TREE_THIS_VOLATILE (array));
2142 return require_complete_type (fold (rval));
2143 }
2144 else
2145 {
2146 tree ar = default_conversion (array);
2147
2148 if (ar == error_mark_node)
2149 return ar;
2150
2151 gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE);
2152 gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE);
2153
2154 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0),
2155 "array indexing");
2156 }
2157 }
2158 \f
2159 /* Build an external reference to identifier ID. FUN indicates
2160 whether this will be used for a function call. LOC is the source
2161 location of the identifier. */
2162 tree
2163 build_external_ref (tree id, int fun, location_t loc)
2164 {
2165 tree ref;
2166 tree decl = lookup_name (id);
2167
2168 /* In Objective-C, an instance variable (ivar) may be preferred to
2169 whatever lookup_name() found. */
2170 decl = objc_lookup_ivar (decl, id);
2171
2172 if (decl && decl != error_mark_node)
2173 ref = decl;
2174 else if (fun)
2175 /* Implicit function declaration. */
2176 ref = implicitly_declare (id);
2177 else if (decl == error_mark_node)
2178 /* Don't complain about something that's already been
2179 complained about. */
2180 return error_mark_node;
2181 else
2182 {
2183 undeclared_variable (id, loc);
2184 return error_mark_node;
2185 }
2186
2187 if (TREE_TYPE (ref) == error_mark_node)
2188 return error_mark_node;
2189
2190 if (TREE_DEPRECATED (ref))
2191 warn_deprecated_use (ref);
2192
2193 /* Recursive call does not count as usage. */
2194 if (ref != current_function_decl)
2195 {
2196 TREE_USED (ref) = 1;
2197 }
2198
2199 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof)
2200 {
2201 if (!in_sizeof && !in_typeof)
2202 C_DECL_USED (ref) = 1;
2203 else if (DECL_INITIAL (ref) == 0
2204 && DECL_EXTERNAL (ref)
2205 && !TREE_PUBLIC (ref))
2206 record_maybe_used_decl (ref);
2207 }
2208
2209 if (TREE_CODE (ref) == CONST_DECL)
2210 {
2211 used_types_insert (TREE_TYPE (ref));
2212 ref = DECL_INITIAL (ref);
2213 TREE_CONSTANT (ref) = 1;
2214 }
2215 else if (current_function_decl != 0
2216 && !DECL_FILE_SCOPE_P (current_function_decl)
2217 && (TREE_CODE (ref) == VAR_DECL
2218 || TREE_CODE (ref) == PARM_DECL
2219 || TREE_CODE (ref) == FUNCTION_DECL))
2220 {
2221 tree context = decl_function_context (ref);
2222
2223 if (context != 0 && context != current_function_decl)
2224 DECL_NONLOCAL (ref) = 1;
2225 }
2226 /* C99 6.7.4p3: An inline definition of a function with external
2227 linkage ... shall not contain a reference to an identifier with
2228 internal linkage. */
2229 else if (current_function_decl != 0
2230 && DECL_DECLARED_INLINE_P (current_function_decl)
2231 && DECL_EXTERNAL (current_function_decl)
2232 && VAR_OR_FUNCTION_DECL_P (ref)
2233 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref))
2234 && ! TREE_PUBLIC (ref)
2235 && DECL_CONTEXT (ref) != current_function_decl)
2236 pedwarn (loc, 0, "%qD is static but used in inline function %qD "
2237 "which is not static", ref, current_function_decl);
2238
2239 return ref;
2240 }
2241
2242 /* Record details of decls possibly used inside sizeof or typeof. */
2243 struct maybe_used_decl
2244 {
2245 /* The decl. */
2246 tree decl;
2247 /* The level seen at (in_sizeof + in_typeof). */
2248 int level;
2249 /* The next one at this level or above, or NULL. */
2250 struct maybe_used_decl *next;
2251 };
2252
2253 static struct maybe_used_decl *maybe_used_decls;
2254
2255 /* Record that DECL, an undefined static function reference seen
2256 inside sizeof or typeof, might be used if the operand of sizeof is
2257 a VLA type or the operand of typeof is a variably modified
2258 type. */
2259
2260 static void
2261 record_maybe_used_decl (tree decl)
2262 {
2263 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2264 t->decl = decl;
2265 t->level = in_sizeof + in_typeof;
2266 t->next = maybe_used_decls;
2267 maybe_used_decls = t;
2268 }
2269
2270 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2271 USED is false, just discard them. If it is true, mark them used
2272 (if no longer inside sizeof or typeof) or move them to the next
2273 level up (if still inside sizeof or typeof). */
2274
2275 void
2276 pop_maybe_used (bool used)
2277 {
2278 struct maybe_used_decl *p = maybe_used_decls;
2279 int cur_level = in_sizeof + in_typeof;
2280 while (p && p->level > cur_level)
2281 {
2282 if (used)
2283 {
2284 if (cur_level == 0)
2285 C_DECL_USED (p->decl) = 1;
2286 else
2287 p->level = cur_level;
2288 }
2289 p = p->next;
2290 }
2291 if (!used || cur_level == 0)
2292 maybe_used_decls = p;
2293 }
2294
2295 /* Return the result of sizeof applied to EXPR. */
2296
2297 struct c_expr
2298 c_expr_sizeof_expr (struct c_expr expr)
2299 {
2300 struct c_expr ret;
2301 if (expr.value == error_mark_node)
2302 {
2303 ret.value = error_mark_node;
2304 ret.original_code = ERROR_MARK;
2305 pop_maybe_used (false);
2306 }
2307 else
2308 {
2309 ret.value = c_sizeof (TREE_TYPE (expr.value));
2310 ret.original_code = ERROR_MARK;
2311 if (c_vla_type_p (TREE_TYPE (expr.value)))
2312 {
2313 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2314 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2315 }
2316 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2317 }
2318 return ret;
2319 }
2320
2321 /* Return the result of sizeof applied to T, a structure for the type
2322 name passed to sizeof (rather than the type itself). */
2323
2324 struct c_expr
2325 c_expr_sizeof_type (struct c_type_name *t)
2326 {
2327 tree type;
2328 struct c_expr ret;
2329 type = groktypename (t);
2330 ret.value = c_sizeof (type);
2331 ret.original_code = ERROR_MARK;
2332 pop_maybe_used (type != error_mark_node
2333 ? C_TYPE_VARIABLE_SIZE (type) : false);
2334 return ret;
2335 }
2336
2337 /* Build a function call to function FUNCTION with parameters PARAMS.
2338 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2339 TREE_VALUE of each node is a parameter-expression.
2340 FUNCTION's data type may be a function type or a pointer-to-function. */
2341
2342 tree
2343 build_function_call (tree function, tree params)
2344 {
2345 tree fntype, fundecl = 0;
2346 tree name = NULL_TREE, result;
2347 tree tem;
2348 int nargs;
2349 tree *argarray;
2350
2351
2352 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2353 STRIP_TYPE_NOPS (function);
2354
2355 /* Convert anything with function type to a pointer-to-function. */
2356 if (TREE_CODE (function) == FUNCTION_DECL)
2357 {
2358 /* Implement type-directed function overloading for builtins.
2359 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2360 handle all the type checking. The result is a complete expression
2361 that implements this function call. */
2362 tem = resolve_overloaded_builtin (function, params);
2363 if (tem)
2364 return tem;
2365
2366 name = DECL_NAME (function);
2367 fundecl = function;
2368 }
2369 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2370 function = function_to_pointer_conversion (function);
2371
2372 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2373 expressions, like those used for ObjC messenger dispatches. */
2374 function = objc_rewrite_function_call (function, params);
2375
2376 fntype = TREE_TYPE (function);
2377
2378 if (TREE_CODE (fntype) == ERROR_MARK)
2379 return error_mark_node;
2380
2381 if (!(TREE_CODE (fntype) == POINTER_TYPE
2382 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2383 {
2384 error ("called object %qE is not a function", function);
2385 return error_mark_node;
2386 }
2387
2388 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2389 current_function_returns_abnormally = 1;
2390
2391 /* fntype now gets the type of function pointed to. */
2392 fntype = TREE_TYPE (fntype);
2393
2394 /* Check that the function is called through a compatible prototype.
2395 If it is not, replace the call by a trap, wrapped up in a compound
2396 expression if necessary. This has the nice side-effect to prevent
2397 the tree-inliner from generating invalid assignment trees which may
2398 blow up in the RTL expander later. */
2399 if (CONVERT_EXPR_P (function)
2400 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2401 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2402 && !comptypes (fntype, TREE_TYPE (tem)))
2403 {
2404 tree return_type = TREE_TYPE (fntype);
2405 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2406 NULL_TREE);
2407
2408 /* This situation leads to run-time undefined behavior. We can't,
2409 therefore, simply error unless we can prove that all possible
2410 executions of the program must execute the code. */
2411 if (warning (0, "function called through a non-compatible type"))
2412 /* We can, however, treat "undefined" any way we please.
2413 Call abort to encourage the user to fix the program. */
2414 inform (input_location, "if this code is reached, the program will abort");
2415
2416 if (VOID_TYPE_P (return_type))
2417 return trap;
2418 else
2419 {
2420 tree rhs;
2421
2422 if (AGGREGATE_TYPE_P (return_type))
2423 rhs = build_compound_literal (return_type,
2424 build_constructor (return_type, 0));
2425 else
2426 rhs = fold_convert (return_type, integer_zero_node);
2427
2428 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2429 }
2430 }
2431
2432 /* Convert the parameters to the types declared in the
2433 function prototype, or apply default promotions. */
2434
2435 nargs = list_length (params);
2436 argarray = (tree *) alloca (nargs * sizeof (tree));
2437 nargs = convert_arguments (nargs, argarray, TYPE_ARG_TYPES (fntype),
2438 params, function, fundecl);
2439 if (nargs < 0)
2440 return error_mark_node;
2441
2442 /* Check that arguments to builtin functions match the expectations. */
2443 if (fundecl
2444 && DECL_BUILT_IN (fundecl)
2445 && DECL_BUILT_IN_CLASS (fundecl) == BUILT_IN_NORMAL
2446 && !check_builtin_function_arguments (fundecl, nargs, argarray))
2447 return error_mark_node;
2448
2449 /* Check that the arguments to the function are valid. */
2450 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2451 TYPE_ARG_TYPES (fntype));
2452
2453 if (require_constant_value)
2454 {
2455 result = fold_build_call_array_initializer (TREE_TYPE (fntype),
2456 function, nargs, argarray);
2457 if (TREE_CONSTANT (result)
2458 && (name == NULL_TREE
2459 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2460 pedwarn_init (input_location, 0, "initializer element is not constant");
2461 }
2462 else
2463 result = fold_build_call_array (TREE_TYPE (fntype),
2464 function, nargs, argarray);
2465
2466 if (VOID_TYPE_P (TREE_TYPE (result)))
2467 return result;
2468 return require_complete_type (result);
2469 }
2470 \f
2471 /* Convert the argument expressions in the list VALUES
2472 to the types in the list TYPELIST. The resulting arguments are
2473 stored in the array ARGARRAY which has size NARGS.
2474
2475 If TYPELIST is exhausted, or when an element has NULL as its type,
2476 perform the default conversions.
2477
2478 PARMLIST is the chain of parm decls for the function being called.
2479 It may be 0, if that info is not available.
2480 It is used only for generating error messages.
2481
2482 FUNCTION is a tree for the called function. It is used only for
2483 error messages, where it is formatted with %qE.
2484
2485 This is also where warnings about wrong number of args are generated.
2486
2487 VALUES is a chain of TREE_LIST nodes with the elements of the list
2488 in the TREE_VALUE slots of those nodes.
2489
2490 Returns the actual number of arguments processed (which may be less
2491 than NARGS in some error situations), or -1 on failure. */
2492
2493 static int
2494 convert_arguments (int nargs, tree *argarray,
2495 tree typelist, tree values, tree function, tree fundecl)
2496 {
2497 tree typetail, valtail;
2498 int parmnum;
2499 const bool type_generic = fundecl
2500 && lookup_attribute ("type generic", TYPE_ATTRIBUTES(TREE_TYPE (fundecl)));
2501 tree selector;
2502
2503 /* Change pointer to function to the function itself for
2504 diagnostics. */
2505 if (TREE_CODE (function) == ADDR_EXPR
2506 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2507 function = TREE_OPERAND (function, 0);
2508
2509 /* Handle an ObjC selector specially for diagnostics. */
2510 selector = objc_message_selector ();
2511
2512 /* Scan the given expressions and types, producing individual
2513 converted arguments and storing them in ARGARRAY. */
2514
2515 for (valtail = values, typetail = typelist, parmnum = 0;
2516 valtail;
2517 valtail = TREE_CHAIN (valtail), parmnum++)
2518 {
2519 tree type = typetail ? TREE_VALUE (typetail) : 0;
2520 tree val = TREE_VALUE (valtail);
2521 tree rname = function;
2522 int argnum = parmnum + 1;
2523 const char *invalid_func_diag;
2524
2525 if (type == void_type_node)
2526 {
2527 error ("too many arguments to function %qE", function);
2528 return parmnum;
2529 }
2530
2531 if (selector && argnum > 2)
2532 {
2533 rname = selector;
2534 argnum -= 2;
2535 }
2536
2537 STRIP_TYPE_NOPS (val);
2538
2539 val = require_complete_type (val);
2540
2541 if (type != 0)
2542 {
2543 /* Formal parm type is specified by a function prototype. */
2544 tree parmval;
2545
2546 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2547 {
2548 error ("type of formal parameter %d is incomplete", parmnum + 1);
2549 parmval = val;
2550 }
2551 else
2552 {
2553 /* Optionally warn about conversions that
2554 differ from the default conversions. */
2555 if (warn_traditional_conversion || warn_traditional)
2556 {
2557 unsigned int formal_prec = TYPE_PRECISION (type);
2558
2559 if (INTEGRAL_TYPE_P (type)
2560 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2561 warning (0, "passing argument %d of %qE as integer "
2562 "rather than floating due to prototype",
2563 argnum, rname);
2564 if (INTEGRAL_TYPE_P (type)
2565 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2566 warning (0, "passing argument %d of %qE as integer "
2567 "rather than complex due to prototype",
2568 argnum, rname);
2569 else if (TREE_CODE (type) == COMPLEX_TYPE
2570 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2571 warning (0, "passing argument %d of %qE as complex "
2572 "rather than floating due to prototype",
2573 argnum, rname);
2574 else if (TREE_CODE (type) == REAL_TYPE
2575 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2576 warning (0, "passing argument %d of %qE as floating "
2577 "rather than integer due to prototype",
2578 argnum, rname);
2579 else if (TREE_CODE (type) == COMPLEX_TYPE
2580 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2581 warning (0, "passing argument %d of %qE as complex "
2582 "rather than integer due to prototype",
2583 argnum, rname);
2584 else if (TREE_CODE (type) == REAL_TYPE
2585 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2586 warning (0, "passing argument %d of %qE as floating "
2587 "rather than complex due to prototype",
2588 argnum, rname);
2589 /* ??? At some point, messages should be written about
2590 conversions between complex types, but that's too messy
2591 to do now. */
2592 else if (TREE_CODE (type) == REAL_TYPE
2593 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2594 {
2595 /* Warn if any argument is passed as `float',
2596 since without a prototype it would be `double'. */
2597 if (formal_prec == TYPE_PRECISION (float_type_node)
2598 && type != dfloat32_type_node)
2599 warning (0, "passing argument %d of %qE as %<float%> "
2600 "rather than %<double%> due to prototype",
2601 argnum, rname);
2602
2603 /* Warn if mismatch between argument and prototype
2604 for decimal float types. Warn of conversions with
2605 binary float types and of precision narrowing due to
2606 prototype. */
2607 else if (type != TREE_TYPE (val)
2608 && (type == dfloat32_type_node
2609 || type == dfloat64_type_node
2610 || type == dfloat128_type_node
2611 || TREE_TYPE (val) == dfloat32_type_node
2612 || TREE_TYPE (val) == dfloat64_type_node
2613 || TREE_TYPE (val) == dfloat128_type_node)
2614 && (formal_prec
2615 <= TYPE_PRECISION (TREE_TYPE (val))
2616 || (type == dfloat128_type_node
2617 && (TREE_TYPE (val)
2618 != dfloat64_type_node
2619 && (TREE_TYPE (val)
2620 != dfloat32_type_node)))
2621 || (type == dfloat64_type_node
2622 && (TREE_TYPE (val)
2623 != dfloat32_type_node))))
2624 warning (0, "passing argument %d of %qE as %qT "
2625 "rather than %qT due to prototype",
2626 argnum, rname, type, TREE_TYPE (val));
2627
2628 }
2629 /* Detect integer changing in width or signedness.
2630 These warnings are only activated with
2631 -Wtraditional-conversion, not with -Wtraditional. */
2632 else if (warn_traditional_conversion && INTEGRAL_TYPE_P (type)
2633 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2634 {
2635 tree would_have_been = default_conversion (val);
2636 tree type1 = TREE_TYPE (would_have_been);
2637
2638 if (TREE_CODE (type) == ENUMERAL_TYPE
2639 && (TYPE_MAIN_VARIANT (type)
2640 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2641 /* No warning if function asks for enum
2642 and the actual arg is that enum type. */
2643 ;
2644 else if (formal_prec != TYPE_PRECISION (type1))
2645 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2646 "with different width due to prototype",
2647 argnum, rname);
2648 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2649 ;
2650 /* Don't complain if the formal parameter type
2651 is an enum, because we can't tell now whether
2652 the value was an enum--even the same enum. */
2653 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2654 ;
2655 else if (TREE_CODE (val) == INTEGER_CST
2656 && int_fits_type_p (val, type))
2657 /* Change in signedness doesn't matter
2658 if a constant value is unaffected. */
2659 ;
2660 /* If the value is extended from a narrower
2661 unsigned type, it doesn't matter whether we
2662 pass it as signed or unsigned; the value
2663 certainly is the same either way. */
2664 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2665 && TYPE_UNSIGNED (TREE_TYPE (val)))
2666 ;
2667 else if (TYPE_UNSIGNED (type))
2668 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2669 "as unsigned due to prototype",
2670 argnum, rname);
2671 else
2672 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2673 "as signed due to prototype", argnum, rname);
2674 }
2675 }
2676
2677 parmval = convert_for_assignment (type, val, ic_argpass,
2678 fundecl, function,
2679 parmnum + 1);
2680
2681 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2682 && INTEGRAL_TYPE_P (type)
2683 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2684 parmval = default_conversion (parmval);
2685 }
2686 argarray[parmnum] = parmval;
2687 }
2688 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2689 && (TYPE_PRECISION (TREE_TYPE (val))
2690 < TYPE_PRECISION (double_type_node))
2691 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2692 {
2693 if (type_generic)
2694 argarray[parmnum] = val;
2695 else
2696 /* Convert `float' to `double'. */
2697 argarray[parmnum] = convert (double_type_node, val);
2698 }
2699 else if ((invalid_func_diag =
2700 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2701 {
2702 error (invalid_func_diag);
2703 return -1;
2704 }
2705 else
2706 /* Convert `short' and `char' to full-size `int'. */
2707 argarray[parmnum] = default_conversion (val);
2708
2709 if (typetail)
2710 typetail = TREE_CHAIN (typetail);
2711 }
2712
2713 gcc_assert (parmnum == nargs);
2714
2715 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2716 {
2717 error ("too few arguments to function %qE", function);
2718 return -1;
2719 }
2720
2721 return parmnum;
2722 }
2723 \f
2724 /* This is the entry point used by the parser to build unary operators
2725 in the input. CODE, a tree_code, specifies the unary operator, and
2726 ARG is the operand. For unary plus, the C parser currently uses
2727 CONVERT_EXPR for code. */
2728
2729 struct c_expr
2730 parser_build_unary_op (enum tree_code code, struct c_expr arg)
2731 {
2732 struct c_expr result;
2733
2734 result.original_code = ERROR_MARK;
2735 result.value = build_unary_op (code, arg.value, 0);
2736
2737 if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value))
2738 overflow_warning (result.value);
2739
2740 return result;
2741 }
2742
2743 /* This is the entry point used by the parser to build binary operators
2744 in the input. CODE, a tree_code, specifies the binary operator, and
2745 ARG1 and ARG2 are the operands. In addition to constructing the
2746 expression, we check for operands that were written with other binary
2747 operators in a way that is likely to confuse the user. */
2748
2749 struct c_expr
2750 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2751 struct c_expr arg2)
2752 {
2753 struct c_expr result;
2754
2755 enum tree_code code1 = arg1.original_code;
2756 enum tree_code code2 = arg2.original_code;
2757
2758 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2759 result.original_code = code;
2760
2761 if (TREE_CODE (result.value) == ERROR_MARK)
2762 return result;
2763
2764 /* Check for cases such as x+y<<z which users are likely
2765 to misinterpret. */
2766 if (warn_parentheses)
2767 warn_about_parentheses (code, code1, code2);
2768
2769 if (TREE_CODE_CLASS (code1) != tcc_comparison)
2770 warn_logical_operator (code, arg1.value, arg2.value);
2771
2772 /* Warn about comparisons against string literals, with the exception
2773 of testing for equality or inequality of a string literal with NULL. */
2774 if (code == EQ_EXPR || code == NE_EXPR)
2775 {
2776 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2777 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2778 warning (OPT_Waddress, "comparison with string literal results in unspecified behavior");
2779 }
2780 else if (TREE_CODE_CLASS (code) == tcc_comparison
2781 && (code1 == STRING_CST || code2 == STRING_CST))
2782 warning (OPT_Waddress, "comparison with string literal results in unspecified behavior");
2783
2784 if (TREE_OVERFLOW_P (result.value)
2785 && !TREE_OVERFLOW_P (arg1.value)
2786 && !TREE_OVERFLOW_P (arg2.value))
2787 overflow_warning (result.value);
2788
2789 return result;
2790 }
2791 \f
2792 /* Return a tree for the difference of pointers OP0 and OP1.
2793 The resulting tree has type int. */
2794
2795 static tree
2796 pointer_diff (tree op0, tree op1)
2797 {
2798 tree restype = ptrdiff_type_node;
2799
2800 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2801 tree con0, con1, lit0, lit1;
2802 tree orig_op1 = op1;
2803
2804 if (TREE_CODE (target_type) == VOID_TYPE)
2805 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
2806 "pointer of type %<void *%> used in subtraction");
2807 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2808 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
2809 "pointer to a function used in subtraction");
2810
2811 /* If the conversion to ptrdiff_type does anything like widening or
2812 converting a partial to an integral mode, we get a convert_expression
2813 that is in the way to do any simplifications.
2814 (fold-const.c doesn't know that the extra bits won't be needed.
2815 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2816 different mode in place.)
2817 So first try to find a common term here 'by hand'; we want to cover
2818 at least the cases that occur in legal static initializers. */
2819 if (CONVERT_EXPR_P (op0)
2820 && (TYPE_PRECISION (TREE_TYPE (op0))
2821 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2822 con0 = TREE_OPERAND (op0, 0);
2823 else
2824 con0 = op0;
2825 if (CONVERT_EXPR_P (op1)
2826 && (TYPE_PRECISION (TREE_TYPE (op1))
2827 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2828 con1 = TREE_OPERAND (op1, 0);
2829 else
2830 con1 = op1;
2831
2832 if (TREE_CODE (con0) == PLUS_EXPR)
2833 {
2834 lit0 = TREE_OPERAND (con0, 1);
2835 con0 = TREE_OPERAND (con0, 0);
2836 }
2837 else
2838 lit0 = integer_zero_node;
2839
2840 if (TREE_CODE (con1) == PLUS_EXPR)
2841 {
2842 lit1 = TREE_OPERAND (con1, 1);
2843 con1 = TREE_OPERAND (con1, 0);
2844 }
2845 else
2846 lit1 = integer_zero_node;
2847
2848 if (operand_equal_p (con0, con1, 0))
2849 {
2850 op0 = lit0;
2851 op1 = lit1;
2852 }
2853
2854
2855 /* First do the subtraction as integers;
2856 then drop through to build the divide operator.
2857 Do not do default conversions on the minus operator
2858 in case restype is a short type. */
2859
2860 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2861 convert (restype, op1), 0);
2862 /* This generates an error if op1 is pointer to incomplete type. */
2863 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2864 error ("arithmetic on pointer to an incomplete type");
2865
2866 /* This generates an error if op0 is pointer to incomplete type. */
2867 op1 = c_size_in_bytes (target_type);
2868
2869 /* Divide by the size, in easiest possible way. */
2870 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2871 }
2872 \f
2873 /* Construct and perhaps optimize a tree representation
2874 for a unary operation. CODE, a tree_code, specifies the operation
2875 and XARG is the operand.
2876 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2877 the default promotions (such as from short to int).
2878 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2879 allows non-lvalues; this is only used to handle conversion of non-lvalue
2880 arrays to pointers in C99. */
2881
2882 tree
2883 build_unary_op (enum tree_code code, tree xarg, int flag)
2884 {
2885 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2886 tree arg = xarg;
2887 tree argtype = 0;
2888 enum tree_code typecode;
2889 tree val;
2890 int noconvert = flag;
2891 const char *invalid_op_diag;
2892
2893 if (code != ADDR_EXPR)
2894 arg = require_complete_type (arg);
2895
2896 typecode = TREE_CODE (TREE_TYPE (arg));
2897 if (typecode == ERROR_MARK)
2898 return error_mark_node;
2899 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2900 typecode = INTEGER_TYPE;
2901
2902 if ((invalid_op_diag
2903 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2904 {
2905 error (invalid_op_diag);
2906 return error_mark_node;
2907 }
2908
2909 switch (code)
2910 {
2911 case CONVERT_EXPR:
2912 /* This is used for unary plus, because a CONVERT_EXPR
2913 is enough to prevent anybody from looking inside for
2914 associativity, but won't generate any code. */
2915 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2916 || typecode == FIXED_POINT_TYPE || typecode == COMPLEX_TYPE
2917 || typecode == VECTOR_TYPE))
2918 {
2919 error ("wrong type argument to unary plus");
2920 return error_mark_node;
2921 }
2922 else if (!noconvert)
2923 arg = default_conversion (arg);
2924 arg = non_lvalue (arg);
2925 break;
2926
2927 case NEGATE_EXPR:
2928 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2929 || typecode == FIXED_POINT_TYPE || typecode == COMPLEX_TYPE
2930 || typecode == VECTOR_TYPE))
2931 {
2932 error ("wrong type argument to unary minus");
2933 return error_mark_node;
2934 }
2935 else if (!noconvert)
2936 arg = default_conversion (arg);
2937 break;
2938
2939 case BIT_NOT_EXPR:
2940 /* ~ works on integer types and non float vectors. */
2941 if (typecode == INTEGER_TYPE
2942 || (typecode == VECTOR_TYPE
2943 && !VECTOR_FLOAT_TYPE_P (TREE_TYPE (arg))))
2944 {
2945 if (!noconvert)
2946 arg = default_conversion (arg);
2947 }
2948 else if (typecode == COMPLEX_TYPE)
2949 {
2950 code = CONJ_EXPR;
2951 pedwarn (input_location, OPT_pedantic,
2952 "ISO C does not support %<~%> for complex conjugation");
2953 if (!noconvert)
2954 arg = default_conversion (arg);
2955 }
2956 else
2957 {
2958 error ("wrong type argument to bit-complement");
2959 return error_mark_node;
2960 }
2961 break;
2962
2963 case ABS_EXPR:
2964 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2965 {
2966 error ("wrong type argument to abs");
2967 return error_mark_node;
2968 }
2969 else if (!noconvert)
2970 arg = default_conversion (arg);
2971 break;
2972
2973 case CONJ_EXPR:
2974 /* Conjugating a real value is a no-op, but allow it anyway. */
2975 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2976 || typecode == COMPLEX_TYPE))
2977 {
2978 error ("wrong type argument to conjugation");
2979 return error_mark_node;
2980 }
2981 else if (!noconvert)
2982 arg = default_conversion (arg);
2983 break;
2984
2985 case TRUTH_NOT_EXPR:
2986 if (typecode != INTEGER_TYPE && typecode != FIXED_POINT_TYPE
2987 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2988 && typecode != COMPLEX_TYPE)
2989 {
2990 error ("wrong type argument to unary exclamation mark");
2991 return error_mark_node;
2992 }
2993 arg = c_objc_common_truthvalue_conversion (arg);
2994 return invert_truthvalue (arg);
2995
2996 case REALPART_EXPR:
2997 if (TREE_CODE (arg) == COMPLEX_CST)
2998 return TREE_REALPART (arg);
2999 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3000 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3001 else
3002 return arg;
3003
3004 case IMAGPART_EXPR:
3005 if (TREE_CODE (arg) == COMPLEX_CST)
3006 return TREE_IMAGPART (arg);
3007 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
3008 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
3009 else
3010 return convert (TREE_TYPE (arg), integer_zero_node);
3011
3012 case PREINCREMENT_EXPR:
3013 case POSTINCREMENT_EXPR:
3014 case PREDECREMENT_EXPR:
3015 case POSTDECREMENT_EXPR:
3016
3017 /* Increment or decrement the real part of the value,
3018 and don't change the imaginary part. */
3019 if (typecode == COMPLEX_TYPE)
3020 {
3021 tree real, imag;
3022
3023 pedwarn (input_location, OPT_pedantic,
3024 "ISO C does not support %<++%> and %<--%> on complex types");
3025
3026 arg = stabilize_reference (arg);
3027 real = build_unary_op (REALPART_EXPR, arg, 1);
3028 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
3029 real = build_unary_op (code, real, 1);
3030 if (real == error_mark_node || imag == error_mark_node)
3031 return error_mark_node;
3032 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
3033 real, imag);
3034 }
3035
3036 /* Report invalid types. */
3037
3038 if (typecode != POINTER_TYPE && typecode != FIXED_POINT_TYPE
3039 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
3040 {
3041 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3042 error ("wrong type argument to increment");
3043 else
3044 error ("wrong type argument to decrement");
3045
3046 return error_mark_node;
3047 }
3048
3049 {
3050 tree inc;
3051 tree result_type = TREE_TYPE (arg);
3052
3053 arg = get_unwidened (arg, 0);
3054 argtype = TREE_TYPE (arg);
3055
3056 /* Compute the increment. */
3057
3058 if (typecode == POINTER_TYPE)
3059 {
3060 /* If pointer target is an undefined struct,
3061 we just cannot know how to do the arithmetic. */
3062 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
3063 {
3064 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3065 error ("increment of pointer to unknown structure");
3066 else
3067 error ("decrement of pointer to unknown structure");
3068 }
3069 else if (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
3070 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)
3071 {
3072 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
3073 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3074 "wrong type argument to increment");
3075 else
3076 pedwarn (input_location, pedantic ? OPT_pedantic : OPT_Wpointer_arith,
3077 "wrong type argument to decrement");
3078 }
3079
3080 inc = c_size_in_bytes (TREE_TYPE (result_type));
3081 inc = fold_convert (sizetype, inc);
3082 }
3083 else if (FRACT_MODE_P (TYPE_MODE (result_type)))
3084 {
3085 /* For signed fract types, we invert ++ to -- or
3086 -- to ++, and change inc from 1 to -1, because
3087 it is not possible to represent 1 in signed fract constants.
3088 For unsigned fract types, the result always overflows and
3089 we get an undefined (original) or the maximum value. */
3090 if (code == PREINCREMENT_EXPR)
3091 code = PREDECREMENT_EXPR;
3092 else if (code == PREDECREMENT_EXPR)
3093 code = PREINCREMENT_EXPR;
3094 else if (code == POSTINCREMENT_EXPR)
3095 code = POSTDECREMENT_EXPR;
3096 else /* code == POSTDECREMENT_EXPR */
3097 code = POSTINCREMENT_EXPR;
3098
3099 inc = integer_minus_one_node;
3100 inc = convert (argtype, inc);
3101 }
3102 else
3103 {
3104 inc = integer_one_node;
3105 inc = convert (argtype, inc);
3106 }
3107
3108 /* Complain about anything else that is not a true lvalue. */
3109 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
3110 || code == POSTINCREMENT_EXPR)
3111 ? lv_increment
3112 : lv_decrement)))
3113 return error_mark_node;
3114
3115 /* Report a read-only lvalue. */
3116 if (TREE_READONLY (arg))
3117 {
3118 readonly_error (arg,
3119 ((code == PREINCREMENT_EXPR
3120 || code == POSTINCREMENT_EXPR)
3121 ? lv_increment : lv_decrement));
3122 return error_mark_node;
3123 }
3124
3125 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3126 val = boolean_increment (code, arg);
3127 else
3128 val = build2 (code, TREE_TYPE (arg), arg, inc);
3129 TREE_SIDE_EFFECTS (val) = 1;
3130 val = convert (result_type, val);
3131 if (TREE_CODE (val) != code)
3132 TREE_NO_WARNING (val) = 1;
3133 return val;
3134 }
3135
3136 case ADDR_EXPR:
3137 /* Note that this operation never does default_conversion. */
3138
3139 /* Let &* cancel out to simplify resulting code. */
3140 if (TREE_CODE (arg) == INDIRECT_REF)
3141 {
3142 /* Don't let this be an lvalue. */
3143 if (lvalue_p (TREE_OPERAND (arg, 0)))
3144 return non_lvalue (TREE_OPERAND (arg, 0));
3145 return TREE_OPERAND (arg, 0);
3146 }
3147
3148 /* For &x[y], return x+y */
3149 if (TREE_CODE (arg) == ARRAY_REF)
3150 {
3151 tree op0 = TREE_OPERAND (arg, 0);
3152 if (!c_mark_addressable (op0))
3153 return error_mark_node;
3154 return build_binary_op (PLUS_EXPR,
3155 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
3156 ? array_to_pointer_conversion (op0)
3157 : op0),
3158 TREE_OPERAND (arg, 1), 1);
3159 }
3160
3161 /* Anything not already handled and not a true memory reference
3162 or a non-lvalue array is an error. */
3163 else if (typecode != FUNCTION_TYPE && !flag
3164 && !lvalue_or_else (arg, lv_addressof))
3165 return error_mark_node;
3166
3167 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3168 argtype = TREE_TYPE (arg);
3169
3170 /* If the lvalue is const or volatile, merge that into the type
3171 to which the address will point. Note that you can't get a
3172 restricted pointer by taking the address of something, so we
3173 only have to deal with `const' and `volatile' here. */
3174 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3175 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3176 argtype = c_build_type_variant (argtype,
3177 TREE_READONLY (arg),
3178 TREE_THIS_VOLATILE (arg));
3179
3180 if (!c_mark_addressable (arg))
3181 return error_mark_node;
3182
3183 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3184 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3185
3186 argtype = build_pointer_type (argtype);
3187
3188 /* ??? Cope with user tricks that amount to offsetof. Delete this
3189 when we have proper support for integer constant expressions. */
3190 val = get_base_address (arg);
3191 if (val && TREE_CODE (val) == INDIRECT_REF
3192 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3193 {
3194 tree op0 = fold_convert (sizetype, fold_offsetof (arg, val)), op1;
3195
3196 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3197 return fold_build2 (POINTER_PLUS_EXPR, argtype, op1, op0);
3198 }
3199
3200 val = build1 (ADDR_EXPR, argtype, arg);
3201
3202 return val;
3203
3204 default:
3205 gcc_unreachable ();
3206 }
3207
3208 if (argtype == 0)
3209 argtype = TREE_TYPE (arg);
3210 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3211 : fold_build1 (code, argtype, arg);
3212 }
3213
3214 /* Return nonzero if REF is an lvalue valid for this language.
3215 Lvalues can be assigned, unless their type has TYPE_READONLY.
3216 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3217
3218 static int
3219 lvalue_p (const_tree ref)
3220 {
3221 const enum tree_code code = TREE_CODE (ref);
3222
3223 switch (code)
3224 {
3225 case REALPART_EXPR:
3226 case IMAGPART_EXPR:
3227 case COMPONENT_REF:
3228 return lvalue_p (TREE_OPERAND (ref, 0));
3229
3230 case COMPOUND_LITERAL_EXPR:
3231 case STRING_CST:
3232 return 1;
3233
3234 case INDIRECT_REF:
3235 case ARRAY_REF:
3236 case VAR_DECL:
3237 case PARM_DECL:
3238 case RESULT_DECL:
3239 case ERROR_MARK:
3240 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3241 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3242
3243 case BIND_EXPR:
3244 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3245
3246 default:
3247 return 0;
3248 }
3249 }
3250 \f
3251 /* Give an error for storing in something that is 'const'. */
3252
3253 static void
3254 readonly_error (tree arg, enum lvalue_use use)
3255 {
3256 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3257 || use == lv_asm);
3258 /* Using this macro rather than (for example) arrays of messages
3259 ensures that all the format strings are checked at compile
3260 time. */
3261 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3262 : (use == lv_increment ? (I) \
3263 : (use == lv_decrement ? (D) : (AS))))
3264 if (TREE_CODE (arg) == COMPONENT_REF)
3265 {
3266 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3267 readonly_error (TREE_OPERAND (arg, 0), use);
3268 else
3269 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3270 G_("increment of read-only member %qD"),
3271 G_("decrement of read-only member %qD"),
3272 G_("read-only member %qD used as %<asm%> output")),
3273 TREE_OPERAND (arg, 1));
3274 }
3275 else if (TREE_CODE (arg) == VAR_DECL)
3276 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3277 G_("increment of read-only variable %qD"),
3278 G_("decrement of read-only variable %qD"),
3279 G_("read-only variable %qD used as %<asm%> output")),
3280 arg);
3281 else
3282 error (READONLY_MSG (G_("assignment of read-only location %qE"),
3283 G_("increment of read-only location %qE"),
3284 G_("decrement of read-only location %qE"),
3285 G_("read-only location %qE used as %<asm%> output")),
3286 arg);
3287 }
3288
3289
3290 /* Return nonzero if REF is an lvalue valid for this language;
3291 otherwise, print an error message and return zero. USE says
3292 how the lvalue is being used and so selects the error message. */
3293
3294 static int
3295 lvalue_or_else (const_tree ref, enum lvalue_use use)
3296 {
3297 int win = lvalue_p (ref);
3298
3299 if (!win)
3300 lvalue_error (use);
3301
3302 return win;
3303 }
3304 \f
3305 /* Mark EXP saying that we need to be able to take the
3306 address of it; it should not be allocated in a register.
3307 Returns true if successful. */
3308
3309 bool
3310 c_mark_addressable (tree exp)
3311 {
3312 tree x = exp;
3313
3314 while (1)
3315 switch (TREE_CODE (x))
3316 {
3317 case COMPONENT_REF:
3318 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3319 {
3320 error
3321 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3322 return false;
3323 }
3324
3325 /* ... fall through ... */
3326
3327 case ADDR_EXPR:
3328 case ARRAY_REF:
3329 case REALPART_EXPR:
3330 case IMAGPART_EXPR:
3331 x = TREE_OPERAND (x, 0);
3332 break;
3333
3334 case COMPOUND_LITERAL_EXPR:
3335 case CONSTRUCTOR:
3336 TREE_ADDRESSABLE (x) = 1;
3337 return true;
3338
3339 case VAR_DECL:
3340 case CONST_DECL:
3341 case PARM_DECL:
3342 case RESULT_DECL:
3343 if (C_DECL_REGISTER (x)
3344 && DECL_NONLOCAL (x))
3345 {
3346 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3347 {
3348 error
3349 ("global register variable %qD used in nested function", x);
3350 return false;
3351 }
3352 pedwarn (input_location, 0, "register variable %qD used in nested function", x);
3353 }
3354 else if (C_DECL_REGISTER (x))
3355 {
3356 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3357 error ("address of global register variable %qD requested", x);
3358 else
3359 error ("address of register variable %qD requested", x);
3360 return false;
3361 }
3362
3363 /* drops in */
3364 case FUNCTION_DECL:
3365 TREE_ADDRESSABLE (x) = 1;
3366 /* drops out */
3367 default:
3368 return true;
3369 }
3370 }
3371 \f
3372 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3373
3374 tree
3375 build_conditional_expr (tree ifexp, tree op1, tree op2)
3376 {
3377 tree type1;
3378 tree type2;
3379 enum tree_code code1;
3380 enum tree_code code2;
3381 tree result_type = NULL;
3382 tree orig_op1 = op1, orig_op2 = op2;
3383
3384 /* Promote both alternatives. */
3385
3386 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3387 op1 = default_conversion (op1);
3388 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3389 op2 = default_conversion (op2);
3390
3391 if (TREE_CODE (ifexp) == ERROR_MARK
3392 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3393 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3394 return error_mark_node;
3395
3396 type1 = TREE_TYPE (op1);
3397 code1 = TREE_CODE (type1);
3398 type2 = TREE_TYPE (op2);
3399 code2 = TREE_CODE (type2);
3400
3401 /* C90 does not permit non-lvalue arrays in conditional expressions.
3402 In C99 they will be pointers by now. */
3403 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3404 {
3405 error ("non-lvalue array in conditional expression");
3406 return error_mark_node;
3407 }
3408
3409 /* Quickly detect the usual case where op1 and op2 have the same type
3410 after promotion. */
3411 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3412 {
3413 if (type1 == type2)
3414 result_type = type1;
3415 else
3416 result_type = TYPE_MAIN_VARIANT (type1);
3417 }
3418 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3419 || code1 == COMPLEX_TYPE)
3420 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3421 || code2 == COMPLEX_TYPE))
3422 {
3423 result_type = c_common_type (type1, type2);
3424
3425 /* If -Wsign-compare, warn here if type1 and type2 have
3426 different signedness. We'll promote the signed to unsigned
3427 and later code won't know it used to be different.
3428 Do this check on the original types, so that explicit casts
3429 will be considered, but default promotions won't. */
3430 if (warn_sign_compare && !skip_evaluation)
3431 {
3432 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3433 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3434
3435 if (unsigned_op1 ^ unsigned_op2)
3436 {
3437 bool ovf;
3438
3439 /* Do not warn if the result type is signed, since the
3440 signed type will only be chosen if it can represent
3441 all the values of the unsigned type. */
3442 if (!TYPE_UNSIGNED (result_type))
3443 /* OK */;
3444 /* Do not warn if the signed quantity is an unsuffixed
3445 integer literal (or some static constant expression
3446 involving such literals) and it is non-negative. */
3447 else if ((unsigned_op2
3448 && tree_expr_nonnegative_warnv_p (op1, &ovf))
3449 || (unsigned_op1
3450 && tree_expr_nonnegative_warnv_p (op2, &ovf)))
3451 /* OK */;
3452 else
3453 warning (OPT_Wsign_compare, "signed and unsigned type in conditional expression");
3454 }
3455 }
3456 }
3457 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3458 {
3459 if (code1 != VOID_TYPE || code2 != VOID_TYPE)
3460 pedwarn (input_location, OPT_pedantic,
3461 "ISO C forbids conditional expr with only one void side");
3462 result_type = void_type_node;
3463 }
3464 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3465 {
3466 if (comp_target_types (type1, type2))
3467 result_type = common_pointer_type (type1, type2);
3468 else if (null_pointer_constant_p (orig_op1))
3469 result_type = qualify_type (type2, type1);
3470 else if (null_pointer_constant_p (orig_op2))
3471 result_type = qualify_type (type1, type2);
3472 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3473 {
3474 if (TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3475 pedwarn (input_location, OPT_pedantic,
3476 "ISO C forbids conditional expr between "
3477 "%<void *%> and function pointer");
3478 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3479 TREE_TYPE (type2)));
3480 }
3481 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3482 {
3483 if (TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3484 pedwarn (input_location, OPT_pedantic,
3485 "ISO C forbids conditional expr between "
3486 "%<void *%> and function pointer");
3487 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3488 TREE_TYPE (type1)));
3489 }
3490 else
3491 {
3492 pedwarn (input_location, 0,
3493 "pointer type mismatch in conditional expression");
3494 result_type = build_pointer_type (void_type_node);
3495 }
3496 }
3497 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3498 {
3499 if (!null_pointer_constant_p (orig_op2))
3500 pedwarn (input_location, 0,
3501 "pointer/integer type mismatch in conditional expression");
3502 else
3503 {
3504 op2 = null_pointer_node;
3505 }
3506 result_type = type1;
3507 }
3508 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3509 {
3510 if (!null_pointer_constant_p (orig_op1))
3511 pedwarn (input_location, 0,
3512 "pointer/integer type mismatch in conditional expression");
3513 else
3514 {
3515 op1 = null_pointer_node;
3516 }
3517 result_type = type2;
3518 }
3519
3520 if (!result_type)
3521 {
3522 if (flag_cond_mismatch)
3523 result_type = void_type_node;
3524 else
3525 {
3526 error ("type mismatch in conditional expression");
3527 return error_mark_node;
3528 }
3529 }
3530
3531 /* Merge const and volatile flags of the incoming types. */
3532 result_type
3533 = build_type_variant (result_type,
3534 TREE_READONLY (op1) || TREE_READONLY (op2),
3535 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3536
3537 if (result_type != TREE_TYPE (op1))
3538 op1 = convert_and_check (result_type, op1);
3539 if (result_type != TREE_TYPE (op2))
3540 op2 = convert_and_check (result_type, op2);
3541
3542 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3543 }
3544 \f
3545 /* Return a compound expression that performs two expressions and
3546 returns the value of the second of them. */
3547
3548 tree
3549 build_compound_expr (tree expr1, tree expr2)
3550 {
3551 if (!TREE_SIDE_EFFECTS (expr1))
3552 {
3553 /* The left-hand operand of a comma expression is like an expression
3554 statement: with -Wunused, we should warn if it doesn't have
3555 any side-effects, unless it was explicitly cast to (void). */
3556 if (warn_unused_value)
3557 {
3558 if (VOID_TYPE_P (TREE_TYPE (expr1))
3559 && CONVERT_EXPR_P (expr1))
3560 ; /* (void) a, b */
3561 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3562 && TREE_CODE (expr1) == COMPOUND_EXPR
3563 && CONVERT_EXPR_P (TREE_OPERAND (expr1, 1)))
3564 ; /* (void) a, (void) b, c */
3565 else
3566 warning (OPT_Wunused_value,
3567 "left-hand operand of comma expression has no effect");
3568 }
3569 }
3570
3571 /* With -Wunused, we should also warn if the left-hand operand does have
3572 side-effects, but computes a value which is not used. For example, in
3573 `foo() + bar(), baz()' the result of the `+' operator is not used,
3574 so we should issue a warning. */
3575 else if (warn_unused_value)
3576 warn_if_unused_value (expr1, input_location);
3577
3578 if (expr2 == error_mark_node)
3579 return error_mark_node;
3580
3581 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3582 }
3583
3584 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3585
3586 tree
3587 build_c_cast (tree type, tree expr)
3588 {
3589 tree value = expr;
3590
3591 if (type == error_mark_node || expr == error_mark_node)
3592 return error_mark_node;
3593
3594 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3595 only in <protocol> qualifications. But when constructing cast expressions,
3596 the protocols do matter and must be kept around. */
3597 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3598 return build1 (NOP_EXPR, type, expr);
3599
3600 type = TYPE_MAIN_VARIANT (type);
3601
3602 if (TREE_CODE (type) == ARRAY_TYPE)
3603 {
3604 error ("cast specifies array type");
3605 return error_mark_node;
3606 }
3607
3608 if (TREE_CODE (type) == FUNCTION_TYPE)
3609 {
3610 error ("cast specifies function type");
3611 return error_mark_node;
3612 }
3613
3614 if (!VOID_TYPE_P (type))
3615 {
3616 value = require_complete_type (value);
3617 if (value == error_mark_node)
3618 return error_mark_node;
3619 }
3620
3621 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3622 {
3623 if (TREE_CODE (type) == RECORD_TYPE
3624 || TREE_CODE (type) == UNION_TYPE)
3625 pedwarn (input_location, OPT_pedantic,
3626 "ISO C forbids casting nonscalar to the same type");
3627 }
3628 else if (TREE_CODE (type) == UNION_TYPE)
3629 {
3630 tree field;
3631
3632 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3633 if (TREE_TYPE (field) != error_mark_node
3634 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3635 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3636 break;
3637
3638 if (field)
3639 {
3640 tree t;
3641
3642 pedwarn (input_location, OPT_pedantic,
3643 "ISO C forbids casts to union type");
3644 t = digest_init (type,
3645 build_constructor_single (type, field, value),
3646 true, 0);
3647 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3648 return t;
3649 }
3650 error ("cast to union type from type not present in union");
3651 return error_mark_node;
3652 }
3653 else
3654 {
3655 tree otype, ovalue;
3656
3657 if (type == void_type_node)
3658 return build1 (CONVERT_EXPR, type, value);
3659
3660 otype = TREE_TYPE (value);
3661
3662 /* Optionally warn about potentially worrisome casts. */
3663
3664 if (warn_cast_qual
3665 && TREE_CODE (type) == POINTER_TYPE
3666 && TREE_CODE (otype) == POINTER_TYPE)
3667 {
3668 tree in_type = type;
3669 tree in_otype = otype;
3670 int added = 0;
3671 int discarded = 0;
3672
3673 /* Check that the qualifiers on IN_TYPE are a superset of
3674 the qualifiers of IN_OTYPE. The outermost level of
3675 POINTER_TYPE nodes is uninteresting and we stop as soon
3676 as we hit a non-POINTER_TYPE node on either type. */
3677 do
3678 {
3679 in_otype = TREE_TYPE (in_otype);
3680 in_type = TREE_TYPE (in_type);
3681
3682 /* GNU C allows cv-qualified function types. 'const'
3683 means the function is very pure, 'volatile' means it
3684 can't return. We need to warn when such qualifiers
3685 are added, not when they're taken away. */
3686 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3687 && TREE_CODE (in_type) == FUNCTION_TYPE)
3688 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3689 else
3690 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3691 }
3692 while (TREE_CODE (in_type) == POINTER_TYPE
3693 && TREE_CODE (in_otype) == POINTER_TYPE);
3694
3695 if (added)
3696 warning (OPT_Wcast_qual, "cast adds new qualifiers to function type");
3697
3698 if (discarded)
3699 /* There are qualifiers present in IN_OTYPE that are not
3700 present in IN_TYPE. */
3701 warning (OPT_Wcast_qual, "cast discards qualifiers from pointer target type");
3702 }
3703
3704 /* Warn about possible alignment problems. */
3705 if (STRICT_ALIGNMENT
3706 && TREE_CODE (type) == POINTER_TYPE
3707 && TREE_CODE (otype) == POINTER_TYPE
3708 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3709 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3710 /* Don't warn about opaque types, where the actual alignment
3711 restriction is unknown. */
3712 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3713 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3714 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3715 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3716 warning (OPT_Wcast_align,
3717 "cast increases required alignment of target type");
3718
3719 if (TREE_CODE (type) == INTEGER_TYPE
3720 && TREE_CODE (otype) == POINTER_TYPE
3721 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3722 /* Unlike conversion of integers to pointers, where the
3723 warning is disabled for converting constants because
3724 of cases such as SIG_*, warn about converting constant
3725 pointers to integers. In some cases it may cause unwanted
3726 sign extension, and a warning is appropriate. */
3727 warning (OPT_Wpointer_to_int_cast,
3728 "cast from pointer to integer of different size");
3729
3730 if (TREE_CODE (value) == CALL_EXPR
3731 && TREE_CODE (type) != TREE_CODE (otype))
3732 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3733 "to non-matching type %qT", otype, type);
3734
3735 if (TREE_CODE (type) == POINTER_TYPE
3736 && TREE_CODE (otype) == INTEGER_TYPE
3737 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3738 /* Don't warn about converting any constant. */
3739 && !TREE_CONSTANT (value))
3740 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3741 "of different size");
3742
3743 if (warn_strict_aliasing <= 2)
3744 strict_aliasing_warning (otype, type, expr);
3745
3746 /* If pedantic, warn for conversions between function and object
3747 pointer types, except for converting a null pointer constant
3748 to function pointer type. */
3749 if (pedantic
3750 && TREE_CODE (type) == POINTER_TYPE
3751 && TREE_CODE (otype) == POINTER_TYPE
3752 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3753 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3754 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
3755 "conversion of function pointer to object pointer type");
3756
3757 if (pedantic
3758 && TREE_CODE (type) == POINTER_TYPE
3759 && TREE_CODE (otype) == POINTER_TYPE
3760 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3761 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3762 && !null_pointer_constant_p (value))
3763 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
3764 "conversion of object pointer to function pointer type");
3765
3766 ovalue = value;
3767 value = convert (type, value);
3768
3769 /* Ignore any integer overflow caused by the cast. */
3770 if (TREE_CODE (value) == INTEGER_CST)
3771 {
3772 if (CONSTANT_CLASS_P (ovalue) && TREE_OVERFLOW (ovalue))
3773 {
3774 if (!TREE_OVERFLOW (value))
3775 {
3776 /* Avoid clobbering a shared constant. */
3777 value = copy_node (value);
3778 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3779 }
3780 }
3781 else if (TREE_OVERFLOW (value))
3782 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3783 value = build_int_cst_wide (TREE_TYPE (value),
3784 TREE_INT_CST_LOW (value),
3785 TREE_INT_CST_HIGH (value));
3786 }
3787 }
3788
3789 /* Don't let a cast be an lvalue. */
3790 if (value == expr)
3791 value = non_lvalue (value);
3792
3793 return value;
3794 }
3795
3796 /* Interpret a cast of expression EXPR to type TYPE. */
3797 tree
3798 c_cast_expr (struct c_type_name *type_name, tree expr)
3799 {
3800 tree type;
3801 int saved_wsp = warn_strict_prototypes;
3802
3803 /* This avoids warnings about unprototyped casts on
3804 integers. E.g. "#define SIG_DFL (void(*)())0". */
3805 if (TREE_CODE (expr) == INTEGER_CST)
3806 warn_strict_prototypes = 0;
3807 type = groktypename (type_name);
3808 warn_strict_prototypes = saved_wsp;
3809
3810 return build_c_cast (type, expr);
3811 }
3812 \f
3813 /* Build an assignment expression of lvalue LHS from value RHS.
3814 MODIFYCODE is the code for a binary operator that we use
3815 to combine the old value of LHS with RHS to get the new value.
3816 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3817
3818 tree
3819 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3820 {
3821 tree result;
3822 tree newrhs;
3823 tree lhstype = TREE_TYPE (lhs);
3824 tree olhstype = lhstype;
3825
3826 /* Types that aren't fully specified cannot be used in assignments. */
3827 lhs = require_complete_type (lhs);
3828
3829 /* Avoid duplicate error messages from operands that had errors. */
3830 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3831 return error_mark_node;
3832
3833 if (!lvalue_or_else (lhs, lv_assign))
3834 return error_mark_node;
3835
3836 STRIP_TYPE_NOPS (rhs);
3837
3838 newrhs = rhs;
3839
3840 /* If a binary op has been requested, combine the old LHS value with the RHS
3841 producing the value we should actually store into the LHS. */
3842
3843 if (modifycode != NOP_EXPR)
3844 {
3845 lhs = stabilize_reference (lhs);
3846 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3847 }
3848
3849 /* Give an error for storing in something that is 'const'. */
3850
3851 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3852 || ((TREE_CODE (lhstype) == RECORD_TYPE
3853 || TREE_CODE (lhstype) == UNION_TYPE)
3854 && C_TYPE_FIELDS_READONLY (lhstype)))
3855 {
3856 readonly_error (lhs, lv_assign);
3857 return error_mark_node;
3858 }
3859
3860 /* If storing into a structure or union member,
3861 it has probably been given type `int'.
3862 Compute the type that would go with
3863 the actual amount of storage the member occupies. */
3864
3865 if (TREE_CODE (lhs) == COMPONENT_REF
3866 && (TREE_CODE (lhstype) == INTEGER_TYPE
3867 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3868 || TREE_CODE (lhstype) == REAL_TYPE
3869 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3870 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3871
3872 /* If storing in a field that is in actuality a short or narrower than one,
3873 we must store in the field in its actual type. */
3874
3875 if (lhstype != TREE_TYPE (lhs))
3876 {
3877 lhs = copy_node (lhs);
3878 TREE_TYPE (lhs) = lhstype;
3879 }
3880
3881 /* Convert new value to destination type. */
3882
3883 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3884 NULL_TREE, NULL_TREE, 0);
3885 if (TREE_CODE (newrhs) == ERROR_MARK)
3886 return error_mark_node;
3887
3888 /* Emit ObjC write barrier, if necessary. */
3889 if (c_dialect_objc () && flag_objc_gc)
3890 {
3891 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3892 if (result)
3893 return result;
3894 }
3895
3896 /* Scan operands. */
3897
3898 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3899 TREE_SIDE_EFFECTS (result) = 1;
3900
3901 /* If we got the LHS in a different type for storing in,
3902 convert the result back to the nominal type of LHS
3903 so that the value we return always has the same type
3904 as the LHS argument. */
3905
3906 if (olhstype == TREE_TYPE (result))
3907 return result;
3908 return convert_for_assignment (olhstype, result, ic_assign,
3909 NULL_TREE, NULL_TREE, 0);
3910 }
3911 \f
3912 /* Convert value RHS to type TYPE as preparation for an assignment
3913 to an lvalue of type TYPE.
3914 The real work of conversion is done by `convert'.
3915 The purpose of this function is to generate error messages
3916 for assignments that are not allowed in C.
3917 ERRTYPE says whether it is argument passing, assignment,
3918 initialization or return.
3919
3920 FUNCTION is a tree for the function being called.
3921 PARMNUM is the number of the argument, for printing in error messages. */
3922
3923 static tree
3924 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3925 tree fundecl, tree function, int parmnum)
3926 {
3927 enum tree_code codel = TREE_CODE (type);
3928 tree rhstype;
3929 enum tree_code coder;
3930 tree rname = NULL_TREE;
3931 bool objc_ok = false;
3932
3933 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3934 {
3935 tree selector;
3936 /* Change pointer to function to the function itself for
3937 diagnostics. */
3938 if (TREE_CODE (function) == ADDR_EXPR
3939 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3940 function = TREE_OPERAND (function, 0);
3941
3942 /* Handle an ObjC selector specially for diagnostics. */
3943 selector = objc_message_selector ();
3944 rname = function;
3945 if (selector && parmnum > 2)
3946 {
3947 rname = selector;
3948 parmnum -= 2;
3949 }
3950 }
3951
3952 /* This macro is used to emit diagnostics to ensure that all format
3953 strings are complete sentences, visible to gettext and checked at
3954 compile time. */
3955 #define WARN_FOR_ASSIGNMENT(LOCATION, OPT, AR, AS, IN, RE) \
3956 do { \
3957 switch (errtype) \
3958 { \
3959 case ic_argpass: \
3960 if (pedwarn (LOCATION, OPT, AR, parmnum, rname)) \
3961 inform (fundecl ? DECL_SOURCE_LOCATION (fundecl) : LOCATION, \
3962 "expected %qT but argument is of type %qT", \
3963 type, rhstype); \
3964 break; \
3965 case ic_argpass_nonproto: \
3966 warning (OPT, AR, parmnum, rname); \
3967 break; \
3968 case ic_assign: \
3969 pedwarn (LOCATION, OPT, AS); \
3970 break; \
3971 case ic_init: \
3972 pedwarn (LOCATION, OPT, IN); \
3973 break; \
3974 case ic_return: \
3975 pedwarn (LOCATION, OPT, RE); \
3976 break; \
3977 default: \
3978 gcc_unreachable (); \
3979 } \
3980 } while (0)
3981
3982 STRIP_TYPE_NOPS (rhs);
3983
3984 if (optimize && TREE_CODE (rhs) == VAR_DECL
3985 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
3986 rhs = decl_constant_value_for_broken_optimization (rhs);
3987
3988 rhstype = TREE_TYPE (rhs);
3989 coder = TREE_CODE (rhstype);
3990
3991 if (coder == ERROR_MARK)
3992 return error_mark_node;
3993
3994 if (c_dialect_objc ())
3995 {
3996 int parmno;
3997
3998 switch (errtype)
3999 {
4000 case ic_return:
4001 parmno = 0;
4002 break;
4003
4004 case ic_assign:
4005 parmno = -1;
4006 break;
4007
4008 case ic_init:
4009 parmno = -2;
4010 break;
4011
4012 default:
4013 parmno = parmnum;
4014 break;
4015 }
4016
4017 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
4018 }
4019
4020 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
4021 return rhs;
4022
4023 if (coder == VOID_TYPE)
4024 {
4025 /* Except for passing an argument to an unprototyped function,
4026 this is a constraint violation. When passing an argument to
4027 an unprototyped function, it is compile-time undefined;
4028 making it a constraint in that case was rejected in
4029 DR#252. */
4030 error ("void value not ignored as it ought to be");
4031 return error_mark_node;
4032 }
4033 rhs = require_complete_type (rhs);
4034 if (rhs == error_mark_node)
4035 return error_mark_node;
4036 /* A type converts to a reference to it.
4037 This code doesn't fully support references, it's just for the
4038 special case of va_start and va_copy. */
4039 if (codel == REFERENCE_TYPE
4040 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
4041 {
4042 if (!lvalue_p (rhs))
4043 {
4044 error ("cannot pass rvalue to reference parameter");
4045 return error_mark_node;
4046 }
4047 if (!c_mark_addressable (rhs))
4048 return error_mark_node;
4049 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
4050
4051 /* We already know that these two types are compatible, but they
4052 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4053 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4054 likely to be va_list, a typedef to __builtin_va_list, which
4055 is different enough that it will cause problems later. */
4056 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
4057 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
4058
4059 rhs = build1 (NOP_EXPR, type, rhs);
4060 return rhs;
4061 }
4062 /* Some types can interconvert without explicit casts. */
4063 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
4064 && vector_types_convertible_p (type, TREE_TYPE (rhs), true))
4065 return convert (type, rhs);
4066 /* Arithmetic types all interconvert, and enum is treated like int. */
4067 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
4068 || codel == FIXED_POINT_TYPE
4069 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
4070 || codel == BOOLEAN_TYPE)
4071 && (coder == INTEGER_TYPE || coder == REAL_TYPE
4072 || coder == FIXED_POINT_TYPE
4073 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
4074 || coder == BOOLEAN_TYPE))
4075 return convert_and_check (type, rhs);
4076
4077 /* Aggregates in different TUs might need conversion. */
4078 if ((codel == RECORD_TYPE || codel == UNION_TYPE)
4079 && codel == coder
4080 && comptypes (type, rhstype))
4081 return convert_and_check (type, rhs);
4082
4083 /* Conversion to a transparent union from its member types.
4084 This applies only to function arguments. */
4085 if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
4086 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
4087 {
4088 tree memb, marginal_memb = NULL_TREE;
4089
4090 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
4091 {
4092 tree memb_type = TREE_TYPE (memb);
4093
4094 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
4095 TYPE_MAIN_VARIANT (rhstype)))
4096 break;
4097
4098 if (TREE_CODE (memb_type) != POINTER_TYPE)
4099 continue;
4100
4101 if (coder == POINTER_TYPE)
4102 {
4103 tree ttl = TREE_TYPE (memb_type);
4104 tree ttr = TREE_TYPE (rhstype);
4105
4106 /* Any non-function converts to a [const][volatile] void *
4107 and vice versa; otherwise, targets must be the same.
4108 Meanwhile, the lhs target must have all the qualifiers of
4109 the rhs. */
4110 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4111 || comp_target_types (memb_type, rhstype))
4112 {
4113 /* If this type won't generate any warnings, use it. */
4114 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
4115 || ((TREE_CODE (ttr) == FUNCTION_TYPE
4116 && TREE_CODE (ttl) == FUNCTION_TYPE)
4117 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4118 == TYPE_QUALS (ttr))
4119 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4120 == TYPE_QUALS (ttl))))
4121 break;
4122
4123 /* Keep looking for a better type, but remember this one. */
4124 if (!marginal_memb)
4125 marginal_memb = memb;
4126 }
4127 }
4128
4129 /* Can convert integer zero to any pointer type. */
4130 if (null_pointer_constant_p (rhs))
4131 {
4132 rhs = null_pointer_node;
4133 break;
4134 }
4135 }
4136
4137 if (memb || marginal_memb)
4138 {
4139 if (!memb)
4140 {
4141 /* We have only a marginally acceptable member type;
4142 it needs a warning. */
4143 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
4144 tree ttr = TREE_TYPE (rhstype);
4145
4146 /* Const and volatile mean something different for function
4147 types, so the usual warnings are not appropriate. */
4148 if (TREE_CODE (ttr) == FUNCTION_TYPE
4149 && TREE_CODE (ttl) == FUNCTION_TYPE)
4150 {
4151 /* Because const and volatile on functions are
4152 restrictions that say the function will not do
4153 certain things, it is okay to use a const or volatile
4154 function where an ordinary one is wanted, but not
4155 vice-versa. */
4156 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4157 WARN_FOR_ASSIGNMENT (input_location, 0,
4158 G_("passing argument %d of %qE "
4159 "makes qualified function "
4160 "pointer from unqualified"),
4161 G_("assignment makes qualified "
4162 "function pointer from "
4163 "unqualified"),
4164 G_("initialization makes qualified "
4165 "function pointer from "
4166 "unqualified"),
4167 G_("return makes qualified function "
4168 "pointer from unqualified"));
4169 }
4170 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4171 WARN_FOR_ASSIGNMENT (input_location, 0,
4172 G_("passing argument %d of %qE discards "
4173 "qualifiers from pointer target type"),
4174 G_("assignment discards qualifiers "
4175 "from pointer target type"),
4176 G_("initialization discards qualifiers "
4177 "from pointer target type"),
4178 G_("return discards qualifiers from "
4179 "pointer target type"));
4180
4181 memb = marginal_memb;
4182 }
4183
4184 if (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl))
4185 pedwarn (input_location, OPT_pedantic,
4186 "ISO C prohibits argument conversion to union type");
4187
4188 rhs = fold_convert (TREE_TYPE (memb), rhs);
4189 return build_constructor_single (type, memb, rhs);
4190 }
4191 }
4192
4193 /* Conversions among pointers */
4194 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4195 && (coder == codel))
4196 {
4197 tree ttl = TREE_TYPE (type);
4198 tree ttr = TREE_TYPE (rhstype);
4199 tree mvl = ttl;
4200 tree mvr = ttr;
4201 bool is_opaque_pointer;
4202 int target_cmp = 0; /* Cache comp_target_types () result. */
4203
4204 if (TREE_CODE (mvl) != ARRAY_TYPE)
4205 mvl = TYPE_MAIN_VARIANT (mvl);
4206 if (TREE_CODE (mvr) != ARRAY_TYPE)
4207 mvr = TYPE_MAIN_VARIANT (mvr);
4208 /* Opaque pointers are treated like void pointers. */
4209 is_opaque_pointer = vector_targets_convertible_p (ttl, ttr);
4210
4211 /* C++ does not allow the implicit conversion void* -> T*. However,
4212 for the purpose of reducing the number of false positives, we
4213 tolerate the special case of
4214
4215 int *p = NULL;
4216
4217 where NULL is typically defined in C to be '(void *) 0'. */
4218 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4219 warning (OPT_Wc___compat, "request for implicit conversion from "
4220 "%qT to %qT not permitted in C++", rhstype, type);
4221
4222 /* Check if the right-hand side has a format attribute but the
4223 left-hand side doesn't. */
4224 if (warn_missing_format_attribute
4225 && check_missing_format_attribute (type, rhstype))
4226 {
4227 switch (errtype)
4228 {
4229 case ic_argpass:
4230 case ic_argpass_nonproto:
4231 warning (OPT_Wmissing_format_attribute,
4232 "argument %d of %qE might be "
4233 "a candidate for a format attribute",
4234 parmnum, rname);
4235 break;
4236 case ic_assign:
4237 warning (OPT_Wmissing_format_attribute,
4238 "assignment left-hand side might be "
4239 "a candidate for a format attribute");
4240 break;
4241 case ic_init:
4242 warning (OPT_Wmissing_format_attribute,
4243 "initialization left-hand side might be "
4244 "a candidate for a format attribute");
4245 break;
4246 case ic_return:
4247 warning (OPT_Wmissing_format_attribute,
4248 "return type might be "
4249 "a candidate for a format attribute");
4250 break;
4251 default:
4252 gcc_unreachable ();
4253 }
4254 }
4255
4256 /* Any non-function converts to a [const][volatile] void *
4257 and vice versa; otherwise, targets must be the same.
4258 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4259 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4260 || (target_cmp = comp_target_types (type, rhstype))
4261 || is_opaque_pointer
4262 || (c_common_unsigned_type (mvl)
4263 == c_common_unsigned_type (mvr)))
4264 {
4265 if (pedantic
4266 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4267 ||
4268 (VOID_TYPE_P (ttr)
4269 && !null_pointer_constant_p (rhs)
4270 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4271 WARN_FOR_ASSIGNMENT (input_location, OPT_pedantic,
4272 G_("ISO C forbids passing argument %d of "
4273 "%qE between function pointer "
4274 "and %<void *%>"),
4275 G_("ISO C forbids assignment between "
4276 "function pointer and %<void *%>"),
4277 G_("ISO C forbids initialization between "
4278 "function pointer and %<void *%>"),
4279 G_("ISO C forbids return between function "
4280 "pointer and %<void *%>"));
4281 /* Const and volatile mean something different for function types,
4282 so the usual warnings are not appropriate. */
4283 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4284 && TREE_CODE (ttl) != FUNCTION_TYPE)
4285 {
4286 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4287 {
4288 /* Types differing only by the presence of the 'volatile'
4289 qualifier are acceptable if the 'volatile' has been added
4290 in by the Objective-C EH machinery. */
4291 if (!objc_type_quals_match (ttl, ttr))
4292 WARN_FOR_ASSIGNMENT (input_location, 0,
4293 G_("passing argument %d of %qE discards "
4294 "qualifiers from pointer target type"),
4295 G_("assignment discards qualifiers "
4296 "from pointer target type"),
4297 G_("initialization discards qualifiers "
4298 "from pointer target type"),
4299 G_("return discards qualifiers from "
4300 "pointer target type"));
4301 }
4302 /* If this is not a case of ignoring a mismatch in signedness,
4303 no warning. */
4304 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4305 || target_cmp)
4306 ;
4307 /* If there is a mismatch, do warn. */
4308 else if (warn_pointer_sign)
4309 WARN_FOR_ASSIGNMENT (input_location, OPT_Wpointer_sign,
4310 G_("pointer targets in passing argument "
4311 "%d of %qE differ in signedness"),
4312 G_("pointer targets in assignment "
4313 "differ in signedness"),
4314 G_("pointer targets in initialization "
4315 "differ in signedness"),
4316 G_("pointer targets in return differ "
4317 "in signedness"));
4318 }
4319 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4320 && TREE_CODE (ttr) == FUNCTION_TYPE)
4321 {
4322 /* Because const and volatile on functions are restrictions
4323 that say the function will not do certain things,
4324 it is okay to use a const or volatile function
4325 where an ordinary one is wanted, but not vice-versa. */
4326 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4327 WARN_FOR_ASSIGNMENT (input_location, 0,
4328 G_("passing argument %d of %qE makes "
4329 "qualified function pointer "
4330 "from unqualified"),
4331 G_("assignment makes qualified function "
4332 "pointer from unqualified"),
4333 G_("initialization makes qualified "
4334 "function pointer from unqualified"),
4335 G_("return makes qualified function "
4336 "pointer from unqualified"));
4337 }
4338 }
4339 else
4340 /* Avoid warning about the volatile ObjC EH puts on decls. */
4341 if (!objc_ok)
4342 WARN_FOR_ASSIGNMENT (input_location, 0,
4343 G_("passing argument %d of %qE from "
4344 "incompatible pointer type"),
4345 G_("assignment from incompatible pointer type"),
4346 G_("initialization from incompatible "
4347 "pointer type"),
4348 G_("return from incompatible pointer type"));
4349
4350 return convert (type, rhs);
4351 }
4352 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4353 {
4354 /* ??? This should not be an error when inlining calls to
4355 unprototyped functions. */
4356 error ("invalid use of non-lvalue array");
4357 return error_mark_node;
4358 }
4359 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4360 {
4361 /* An explicit constant 0 can convert to a pointer,
4362 or one that results from arithmetic, even including
4363 a cast to integer type. */
4364 if (!null_pointer_constant_p (rhs))
4365 WARN_FOR_ASSIGNMENT (input_location, 0,
4366 G_("passing argument %d of %qE makes "
4367 "pointer from integer without a cast"),
4368 G_("assignment makes pointer from integer "
4369 "without a cast"),
4370 G_("initialization makes pointer from "
4371 "integer without a cast"),
4372 G_("return makes pointer from integer "
4373 "without a cast"));
4374
4375 return convert (type, rhs);
4376 }
4377 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4378 {
4379 WARN_FOR_ASSIGNMENT (input_location, 0,
4380 G_("passing argument %d of %qE makes integer "
4381 "from pointer without a cast"),
4382 G_("assignment makes integer from pointer "
4383 "without a cast"),
4384 G_("initialization makes integer from pointer "
4385 "without a cast"),
4386 G_("return makes integer from pointer "
4387 "without a cast"));
4388 return convert (type, rhs);
4389 }
4390 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4391 return convert (type, rhs);
4392
4393 switch (errtype)
4394 {
4395 case ic_argpass:
4396 case ic_argpass_nonproto:
4397 /* ??? This should not be an error when inlining calls to
4398 unprototyped functions. */
4399 error ("incompatible type for argument %d of %qE", parmnum, rname);
4400 break;
4401 case ic_assign:
4402 error ("incompatible types in assignment");
4403 break;
4404 case ic_init:
4405 error ("incompatible types in initialization");
4406 break;
4407 case ic_return:
4408 error ("incompatible types in return");
4409 break;
4410 default:
4411 gcc_unreachable ();
4412 }
4413
4414 return error_mark_node;
4415 }
4416 \f
4417 /* If VALUE is a compound expr all of whose expressions are constant, then
4418 return its value. Otherwise, return error_mark_node.
4419
4420 This is for handling COMPOUND_EXPRs as initializer elements
4421 which is allowed with a warning when -pedantic is specified. */
4422
4423 static tree
4424 valid_compound_expr_initializer (tree value, tree endtype)
4425 {
4426 if (TREE_CODE (value) == COMPOUND_EXPR)
4427 {
4428 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4429 == error_mark_node)
4430 return error_mark_node;
4431 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4432 endtype);
4433 }
4434 else if (!initializer_constant_valid_p (value, endtype))
4435 return error_mark_node;
4436 else
4437 return value;
4438 }
4439 \f
4440 /* Perform appropriate conversions on the initial value of a variable,
4441 store it in the declaration DECL,
4442 and print any error messages that are appropriate.
4443 If the init is invalid, store an ERROR_MARK. */
4444
4445 void
4446 store_init_value (tree decl, tree init)
4447 {
4448 tree value, type;
4449
4450 /* If variable's type was invalidly declared, just ignore it. */
4451
4452 type = TREE_TYPE (decl);
4453 if (TREE_CODE (type) == ERROR_MARK)
4454 return;
4455
4456 /* Digest the specified initializer into an expression. */
4457
4458 value = digest_init (type, init, true, TREE_STATIC (decl));
4459
4460 /* Store the expression if valid; else report error. */
4461
4462 if (!in_system_header
4463 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4464 warning (OPT_Wtraditional, "traditional C rejects automatic "
4465 "aggregate initialization");
4466
4467 DECL_INITIAL (decl) = value;
4468
4469 /* ANSI wants warnings about out-of-range constant initializers. */
4470 STRIP_TYPE_NOPS (value);
4471 if (TREE_STATIC (decl))
4472 constant_expression_warning (value);
4473
4474 /* Check if we need to set array size from compound literal size. */
4475 if (TREE_CODE (type) == ARRAY_TYPE
4476 && TYPE_DOMAIN (type) == 0
4477 && value != error_mark_node)
4478 {
4479 tree inside_init = init;
4480
4481 STRIP_TYPE_NOPS (inside_init);
4482 inside_init = fold (inside_init);
4483
4484 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4485 {
4486 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4487
4488 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4489 {
4490 /* For int foo[] = (int [3]){1}; we need to set array size
4491 now since later on array initializer will be just the
4492 brace enclosed list of the compound literal. */
4493 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4494 TREE_TYPE (decl) = type;
4495 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4496 layout_type (type);
4497 layout_decl (cldecl, 0);
4498 }
4499 }
4500 }
4501 }
4502 \f
4503 /* Methods for storing and printing names for error messages. */
4504
4505 /* Implement a spelling stack that allows components of a name to be pushed
4506 and popped. Each element on the stack is this structure. */
4507
4508 struct spelling
4509 {
4510 int kind;
4511 union
4512 {
4513 unsigned HOST_WIDE_INT i;
4514 const char *s;
4515 } u;
4516 };
4517
4518 #define SPELLING_STRING 1
4519 #define SPELLING_MEMBER 2
4520 #define SPELLING_BOUNDS 3
4521
4522 static struct spelling *spelling; /* Next stack element (unused). */
4523 static struct spelling *spelling_base; /* Spelling stack base. */
4524 static int spelling_size; /* Size of the spelling stack. */
4525
4526 /* Macros to save and restore the spelling stack around push_... functions.
4527 Alternative to SAVE_SPELLING_STACK. */
4528
4529 #define SPELLING_DEPTH() (spelling - spelling_base)
4530 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4531
4532 /* Push an element on the spelling stack with type KIND and assign VALUE
4533 to MEMBER. */
4534
4535 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4536 { \
4537 int depth = SPELLING_DEPTH (); \
4538 \
4539 if (depth >= spelling_size) \
4540 { \
4541 spelling_size += 10; \
4542 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4543 spelling_size); \
4544 RESTORE_SPELLING_DEPTH (depth); \
4545 } \
4546 \
4547 spelling->kind = (KIND); \
4548 spelling->MEMBER = (VALUE); \
4549 spelling++; \
4550 }
4551
4552 /* Push STRING on the stack. Printed literally. */
4553
4554 static void
4555 push_string (const char *string)
4556 {
4557 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4558 }
4559
4560 /* Push a member name on the stack. Printed as '.' STRING. */
4561
4562 static void
4563 push_member_name (tree decl)
4564 {
4565 const char *const string
4566 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4567 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4568 }
4569
4570 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4571
4572 static void
4573 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4574 {
4575 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4576 }
4577
4578 /* Compute the maximum size in bytes of the printed spelling. */
4579
4580 static int
4581 spelling_length (void)
4582 {
4583 int size = 0;
4584 struct spelling *p;
4585
4586 for (p = spelling_base; p < spelling; p++)
4587 {
4588 if (p->kind == SPELLING_BOUNDS)
4589 size += 25;
4590 else
4591 size += strlen (p->u.s) + 1;
4592 }
4593
4594 return size;
4595 }
4596
4597 /* Print the spelling to BUFFER and return it. */
4598
4599 static char *
4600 print_spelling (char *buffer)
4601 {
4602 char *d = buffer;
4603 struct spelling *p;
4604
4605 for (p = spelling_base; p < spelling; p++)
4606 if (p->kind == SPELLING_BOUNDS)
4607 {
4608 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4609 d += strlen (d);
4610 }
4611 else
4612 {
4613 const char *s;
4614 if (p->kind == SPELLING_MEMBER)
4615 *d++ = '.';
4616 for (s = p->u.s; (*d = *s++); d++)
4617 ;
4618 }
4619 *d++ = '\0';
4620 return buffer;
4621 }
4622
4623 /* Issue an error message for a bad initializer component.
4624 MSGID identifies the message.
4625 The component name is taken from the spelling stack. */
4626
4627 void
4628 error_init (const char *msgid)
4629 {
4630 char *ofwhat;
4631
4632 error ("%s", _(msgid));
4633 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4634 if (*ofwhat)
4635 error ("(near initialization for %qs)", ofwhat);
4636 }
4637
4638 /* Issue a pedantic warning for a bad initializer component. OPT is
4639 the option OPT_* (from options.h) controlling this warning or 0 if
4640 it is unconditionally given. MSGID identifies the message. The
4641 component name is taken from the spelling stack. */
4642
4643 void
4644 pedwarn_init (location_t location, int opt, const char *msgid)
4645 {
4646 char *ofwhat;
4647
4648 pedwarn (location, opt, "%s", _(msgid));
4649 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4650 if (*ofwhat)
4651 pedwarn (location, opt, "(near initialization for %qs)", ofwhat);
4652 }
4653
4654 /* Issue a warning for a bad initializer component.
4655
4656 OPT is the OPT_W* value corresponding to the warning option that
4657 controls this warning. MSGID identifies the message. The
4658 component name is taken from the spelling stack. */
4659
4660 static void
4661 warning_init (int opt, const char *msgid)
4662 {
4663 char *ofwhat;
4664
4665 warning (opt, "%s", _(msgid));
4666 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4667 if (*ofwhat)
4668 warning (opt, "(near initialization for %qs)", ofwhat);
4669 }
4670 \f
4671 /* If TYPE is an array type and EXPR is a parenthesized string
4672 constant, warn if pedantic that EXPR is being used to initialize an
4673 object of type TYPE. */
4674
4675 void
4676 maybe_warn_string_init (tree type, struct c_expr expr)
4677 {
4678 if (pedantic
4679 && TREE_CODE (type) == ARRAY_TYPE
4680 && TREE_CODE (expr.value) == STRING_CST
4681 && expr.original_code != STRING_CST)
4682 pedwarn_init (input_location, OPT_pedantic,
4683 "array initialized from parenthesized string constant");
4684 }
4685
4686 /* Digest the parser output INIT as an initializer for type TYPE.
4687 Return a C expression of type TYPE to represent the initial value.
4688
4689 If INIT is a string constant, STRICT_STRING is true if it is
4690 unparenthesized or we should not warn here for it being parenthesized.
4691 For other types of INIT, STRICT_STRING is not used.
4692
4693 REQUIRE_CONSTANT requests an error if non-constant initializers or
4694 elements are seen. */
4695
4696 static tree
4697 digest_init (tree type, tree init, bool strict_string, int require_constant)
4698 {
4699 enum tree_code code = TREE_CODE (type);
4700 tree inside_init = init;
4701
4702 if (type == error_mark_node
4703 || !init
4704 || init == error_mark_node
4705 || TREE_TYPE (init) == error_mark_node)
4706 return error_mark_node;
4707
4708 STRIP_TYPE_NOPS (inside_init);
4709
4710 inside_init = fold (inside_init);
4711
4712 /* Initialization of an array of chars from a string constant
4713 optionally enclosed in braces. */
4714
4715 if (code == ARRAY_TYPE && inside_init
4716 && TREE_CODE (inside_init) == STRING_CST)
4717 {
4718 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4719 /* Note that an array could be both an array of character type
4720 and an array of wchar_t if wchar_t is signed char or unsigned
4721 char. */
4722 bool char_array = (typ1 == char_type_node
4723 || typ1 == signed_char_type_node
4724 || typ1 == unsigned_char_type_node);
4725 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4726 bool char16_array = !!comptypes (typ1, char16_type_node);
4727 bool char32_array = !!comptypes (typ1, char32_type_node);
4728
4729 if (char_array || wchar_array || char16_array || char32_array)
4730 {
4731 struct c_expr expr;
4732 tree typ2 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)));
4733 expr.value = inside_init;
4734 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4735 maybe_warn_string_init (type, expr);
4736
4737 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4738 TYPE_MAIN_VARIANT (type)))
4739 return inside_init;
4740
4741 if (char_array)
4742 {
4743 if (typ2 != char_type_node)
4744 {
4745 error_init ("char-array initialized from wide string");
4746 return error_mark_node;
4747 }
4748 }
4749 else
4750 {
4751 if (typ2 == char_type_node)
4752 {
4753 error_init ("wide character array initialized from non-wide "
4754 "string");
4755 return error_mark_node;
4756 }
4757 else if (!comptypes(typ1, typ2))
4758 {
4759 error_init ("wide character array initialized from "
4760 "incompatible wide string");
4761 return error_mark_node;
4762 }
4763 }
4764
4765 TREE_TYPE (inside_init) = type;
4766 if (TYPE_DOMAIN (type) != 0
4767 && TYPE_SIZE (type) != 0
4768 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4769 /* Subtract the size of a single (possibly wide) character
4770 because it's ok to ignore the terminating null char
4771 that is counted in the length of the constant. */
4772 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4773 TREE_STRING_LENGTH (inside_init)
4774 - (TYPE_PRECISION (typ1)
4775 / BITS_PER_UNIT)))
4776 pedwarn_init (input_location, 0,
4777 "initializer-string for array of chars is too long");
4778
4779 return inside_init;
4780 }
4781 else if (INTEGRAL_TYPE_P (typ1))
4782 {
4783 error_init ("array of inappropriate type initialized "
4784 "from string constant");
4785 return error_mark_node;
4786 }
4787 }
4788
4789 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4790 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4791 below and handle as a constructor. */
4792 if (code == VECTOR_TYPE
4793 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4794 && vector_types_convertible_p (TREE_TYPE (inside_init), type, true)
4795 && TREE_CONSTANT (inside_init))
4796 {
4797 if (TREE_CODE (inside_init) == VECTOR_CST
4798 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4799 TYPE_MAIN_VARIANT (type)))
4800 return inside_init;
4801
4802 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4803 {
4804 unsigned HOST_WIDE_INT ix;
4805 tree value;
4806 bool constant_p = true;
4807
4808 /* Iterate through elements and check if all constructor
4809 elements are *_CSTs. */
4810 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4811 if (!CONSTANT_CLASS_P (value))
4812 {
4813 constant_p = false;
4814 break;
4815 }
4816
4817 if (constant_p)
4818 return build_vector_from_ctor (type,
4819 CONSTRUCTOR_ELTS (inside_init));
4820 }
4821 }
4822
4823 if (warn_sequence_point)
4824 verify_sequence_points (inside_init);
4825
4826 /* Any type can be initialized
4827 from an expression of the same type, optionally with braces. */
4828
4829 if (inside_init && TREE_TYPE (inside_init) != 0
4830 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4831 TYPE_MAIN_VARIANT (type))
4832 || (code == ARRAY_TYPE
4833 && comptypes (TREE_TYPE (inside_init), type))
4834 || (code == VECTOR_TYPE
4835 && comptypes (TREE_TYPE (inside_init), type))
4836 || (code == POINTER_TYPE
4837 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4838 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4839 TREE_TYPE (type)))))
4840 {
4841 if (code == POINTER_TYPE)
4842 {
4843 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4844 {
4845 if (TREE_CODE (inside_init) == STRING_CST
4846 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4847 inside_init = array_to_pointer_conversion (inside_init);
4848 else
4849 {
4850 error_init ("invalid use of non-lvalue array");
4851 return error_mark_node;
4852 }
4853 }
4854 }
4855
4856 if (code == VECTOR_TYPE)
4857 /* Although the types are compatible, we may require a
4858 conversion. */
4859 inside_init = convert (type, inside_init);
4860
4861 if (require_constant
4862 && (code == VECTOR_TYPE || !flag_isoc99)
4863 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4864 {
4865 /* As an extension, allow initializing objects with static storage
4866 duration with compound literals (which are then treated just as
4867 the brace enclosed list they contain). Also allow this for
4868 vectors, as we can only assign them with compound literals. */
4869 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4870 inside_init = DECL_INITIAL (decl);
4871 }
4872
4873 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4874 && TREE_CODE (inside_init) != CONSTRUCTOR)
4875 {
4876 error_init ("array initialized from non-constant array expression");
4877 return error_mark_node;
4878 }
4879
4880 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4881 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4882
4883 /* Compound expressions can only occur here if -pedantic or
4884 -pedantic-errors is specified. In the later case, we always want
4885 an error. In the former case, we simply want a warning. */
4886 if (require_constant && pedantic
4887 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4888 {
4889 inside_init
4890 = valid_compound_expr_initializer (inside_init,
4891 TREE_TYPE (inside_init));
4892 if (inside_init == error_mark_node)
4893 error_init ("initializer element is not constant");
4894 else
4895 pedwarn_init (input_location, OPT_pedantic,
4896 "initializer element is not constant");
4897 if (flag_pedantic_errors)
4898 inside_init = error_mark_node;
4899 }
4900 else if (require_constant
4901 && !initializer_constant_valid_p (inside_init,
4902 TREE_TYPE (inside_init)))
4903 {
4904 error_init ("initializer element is not constant");
4905 inside_init = error_mark_node;
4906 }
4907
4908 /* Added to enable additional -Wmissing-format-attribute warnings. */
4909 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4910 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4911 NULL_TREE, 0);
4912 return inside_init;
4913 }
4914
4915 /* Handle scalar types, including conversions. */
4916
4917 if (code == INTEGER_TYPE || code == REAL_TYPE || code == FIXED_POINT_TYPE
4918 || code == POINTER_TYPE || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE
4919 || code == COMPLEX_TYPE || code == VECTOR_TYPE)
4920 {
4921 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4922 && (TREE_CODE (init) == STRING_CST
4923 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4924 init = array_to_pointer_conversion (init);
4925 inside_init
4926 = convert_for_assignment (type, init, ic_init,
4927 NULL_TREE, NULL_TREE, 0);
4928
4929 /* Check to see if we have already given an error message. */
4930 if (inside_init == error_mark_node)
4931 ;
4932 else if (require_constant && !TREE_CONSTANT (inside_init))
4933 {
4934 error_init ("initializer element is not constant");
4935 inside_init = error_mark_node;
4936 }
4937 else if (require_constant
4938 && !initializer_constant_valid_p (inside_init,
4939 TREE_TYPE (inside_init)))
4940 {
4941 error_init ("initializer element is not computable at load time");
4942 inside_init = error_mark_node;
4943 }
4944
4945 return inside_init;
4946 }
4947
4948 /* Come here only for records and arrays. */
4949
4950 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4951 {
4952 error_init ("variable-sized object may not be initialized");
4953 return error_mark_node;
4954 }
4955
4956 error_init ("invalid initializer");
4957 return error_mark_node;
4958 }
4959 \f
4960 /* Handle initializers that use braces. */
4961
4962 /* Type of object we are accumulating a constructor for.
4963 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4964 static tree constructor_type;
4965
4966 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4967 left to fill. */
4968 static tree constructor_fields;
4969
4970 /* For an ARRAY_TYPE, this is the specified index
4971 at which to store the next element we get. */
4972 static tree constructor_index;
4973
4974 /* For an ARRAY_TYPE, this is the maximum index. */
4975 static tree constructor_max_index;
4976
4977 /* For a RECORD_TYPE, this is the first field not yet written out. */
4978 static tree constructor_unfilled_fields;
4979
4980 /* For an ARRAY_TYPE, this is the index of the first element
4981 not yet written out. */
4982 static tree constructor_unfilled_index;
4983
4984 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4985 This is so we can generate gaps between fields, when appropriate. */
4986 static tree constructor_bit_index;
4987
4988 /* If we are saving up the elements rather than allocating them,
4989 this is the list of elements so far (in reverse order,
4990 most recent first). */
4991 static VEC(constructor_elt,gc) *constructor_elements;
4992
4993 /* 1 if constructor should be incrementally stored into a constructor chain,
4994 0 if all the elements should be kept in AVL tree. */
4995 static int constructor_incremental;
4996
4997 /* 1 if so far this constructor's elements are all compile-time constants. */
4998 static int constructor_constant;
4999
5000 /* 1 if so far this constructor's elements are all valid address constants. */
5001 static int constructor_simple;
5002
5003 /* 1 if this constructor is erroneous so far. */
5004 static int constructor_erroneous;
5005
5006 /* Structure for managing pending initializer elements, organized as an
5007 AVL tree. */
5008
5009 struct init_node
5010 {
5011 struct init_node *left, *right;
5012 struct init_node *parent;
5013 int balance;
5014 tree purpose;
5015 tree value;
5016 };
5017
5018 /* Tree of pending elements at this constructor level.
5019 These are elements encountered out of order
5020 which belong at places we haven't reached yet in actually
5021 writing the output.
5022 Will never hold tree nodes across GC runs. */
5023 static struct init_node *constructor_pending_elts;
5024
5025 /* The SPELLING_DEPTH of this constructor. */
5026 static int constructor_depth;
5027
5028 /* DECL node for which an initializer is being read.
5029 0 means we are reading a constructor expression
5030 such as (struct foo) {...}. */
5031 static tree constructor_decl;
5032
5033 /* Nonzero if this is an initializer for a top-level decl. */
5034 static int constructor_top_level;
5035
5036 /* Nonzero if there were any member designators in this initializer. */
5037 static int constructor_designated;
5038
5039 /* Nesting depth of designator list. */
5040 static int designator_depth;
5041
5042 /* Nonzero if there were diagnosed errors in this designator list. */
5043 static int designator_erroneous;
5044
5045 \f
5046 /* This stack has a level for each implicit or explicit level of
5047 structuring in the initializer, including the outermost one. It
5048 saves the values of most of the variables above. */
5049
5050 struct constructor_range_stack;
5051
5052 struct constructor_stack
5053 {
5054 struct constructor_stack *next;
5055 tree type;
5056 tree fields;
5057 tree index;
5058 tree max_index;
5059 tree unfilled_index;
5060 tree unfilled_fields;
5061 tree bit_index;
5062 VEC(constructor_elt,gc) *elements;
5063 struct init_node *pending_elts;
5064 int offset;
5065 int depth;
5066 /* If value nonzero, this value should replace the entire
5067 constructor at this level. */
5068 struct c_expr replacement_value;
5069 struct constructor_range_stack *range_stack;
5070 char constant;
5071 char simple;
5072 char implicit;
5073 char erroneous;
5074 char outer;
5075 char incremental;
5076 char designated;
5077 };
5078
5079 static struct constructor_stack *constructor_stack;
5080
5081 /* This stack represents designators from some range designator up to
5082 the last designator in the list. */
5083
5084 struct constructor_range_stack
5085 {
5086 struct constructor_range_stack *next, *prev;
5087 struct constructor_stack *stack;
5088 tree range_start;
5089 tree index;
5090 tree range_end;
5091 tree fields;
5092 };
5093
5094 static struct constructor_range_stack *constructor_range_stack;
5095
5096 /* This stack records separate initializers that are nested.
5097 Nested initializers can't happen in ANSI C, but GNU C allows them
5098 in cases like { ... (struct foo) { ... } ... }. */
5099
5100 struct initializer_stack
5101 {
5102 struct initializer_stack *next;
5103 tree decl;
5104 struct constructor_stack *constructor_stack;
5105 struct constructor_range_stack *constructor_range_stack;
5106 VEC(constructor_elt,gc) *elements;
5107 struct spelling *spelling;
5108 struct spelling *spelling_base;
5109 int spelling_size;
5110 char top_level;
5111 char require_constant_value;
5112 char require_constant_elements;
5113 };
5114
5115 static struct initializer_stack *initializer_stack;
5116 \f
5117 /* Prepare to parse and output the initializer for variable DECL. */
5118
5119 void
5120 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
5121 {
5122 const char *locus;
5123 struct initializer_stack *p = XNEW (struct initializer_stack);
5124
5125 p->decl = constructor_decl;
5126 p->require_constant_value = require_constant_value;
5127 p->require_constant_elements = require_constant_elements;
5128 p->constructor_stack = constructor_stack;
5129 p->constructor_range_stack = constructor_range_stack;
5130 p->elements = constructor_elements;
5131 p->spelling = spelling;
5132 p->spelling_base = spelling_base;
5133 p->spelling_size = spelling_size;
5134 p->top_level = constructor_top_level;
5135 p->next = initializer_stack;
5136 initializer_stack = p;
5137
5138 constructor_decl = decl;
5139 constructor_designated = 0;
5140 constructor_top_level = top_level;
5141
5142 if (decl != 0 && decl != error_mark_node)
5143 {
5144 require_constant_value = TREE_STATIC (decl);
5145 require_constant_elements
5146 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5147 /* For a scalar, you can always use any value to initialize,
5148 even within braces. */
5149 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5150 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5151 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5152 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5153 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5154 }
5155 else
5156 {
5157 require_constant_value = 0;
5158 require_constant_elements = 0;
5159 locus = "(anonymous)";
5160 }
5161
5162 constructor_stack = 0;
5163 constructor_range_stack = 0;
5164
5165 missing_braces_mentioned = 0;
5166
5167 spelling_base = 0;
5168 spelling_size = 0;
5169 RESTORE_SPELLING_DEPTH (0);
5170
5171 if (locus)
5172 push_string (locus);
5173 }
5174
5175 void
5176 finish_init (void)
5177 {
5178 struct initializer_stack *p = initializer_stack;
5179
5180 /* Free the whole constructor stack of this initializer. */
5181 while (constructor_stack)
5182 {
5183 struct constructor_stack *q = constructor_stack;
5184 constructor_stack = q->next;
5185 free (q);
5186 }
5187
5188 gcc_assert (!constructor_range_stack);
5189
5190 /* Pop back to the data of the outer initializer (if any). */
5191 free (spelling_base);
5192
5193 constructor_decl = p->decl;
5194 require_constant_value = p->require_constant_value;
5195 require_constant_elements = p->require_constant_elements;
5196 constructor_stack = p->constructor_stack;
5197 constructor_range_stack = p->constructor_range_stack;
5198 constructor_elements = p->elements;
5199 spelling = p->spelling;
5200 spelling_base = p->spelling_base;
5201 spelling_size = p->spelling_size;
5202 constructor_top_level = p->top_level;
5203 initializer_stack = p->next;
5204 free (p);
5205 }
5206 \f
5207 /* Call here when we see the initializer is surrounded by braces.
5208 This is instead of a call to push_init_level;
5209 it is matched by a call to pop_init_level.
5210
5211 TYPE is the type to initialize, for a constructor expression.
5212 For an initializer for a decl, TYPE is zero. */
5213
5214 void
5215 really_start_incremental_init (tree type)
5216 {
5217 struct constructor_stack *p = XNEW (struct constructor_stack);
5218
5219 if (type == 0)
5220 type = TREE_TYPE (constructor_decl);
5221
5222 if (targetm.vector_opaque_p (type))
5223 error ("opaque vector types cannot be initialized");
5224
5225 p->type = constructor_type;
5226 p->fields = constructor_fields;
5227 p->index = constructor_index;
5228 p->max_index = constructor_max_index;
5229 p->unfilled_index = constructor_unfilled_index;
5230 p->unfilled_fields = constructor_unfilled_fields;
5231 p->bit_index = constructor_bit_index;
5232 p->elements = constructor_elements;
5233 p->constant = constructor_constant;
5234 p->simple = constructor_simple;
5235 p->erroneous = constructor_erroneous;
5236 p->pending_elts = constructor_pending_elts;
5237 p->depth = constructor_depth;
5238 p->replacement_value.value = 0;
5239 p->replacement_value.original_code = ERROR_MARK;
5240 p->implicit = 0;
5241 p->range_stack = 0;
5242 p->outer = 0;
5243 p->incremental = constructor_incremental;
5244 p->designated = constructor_designated;
5245 p->next = 0;
5246 constructor_stack = p;
5247
5248 constructor_constant = 1;
5249 constructor_simple = 1;
5250 constructor_depth = SPELLING_DEPTH ();
5251 constructor_elements = 0;
5252 constructor_pending_elts = 0;
5253 constructor_type = type;
5254 constructor_incremental = 1;
5255 constructor_designated = 0;
5256 designator_depth = 0;
5257 designator_erroneous = 0;
5258
5259 if (TREE_CODE (constructor_type) == RECORD_TYPE
5260 || TREE_CODE (constructor_type) == UNION_TYPE)
5261 {
5262 constructor_fields = TYPE_FIELDS (constructor_type);
5263 /* Skip any nameless bit fields at the beginning. */
5264 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5265 && DECL_NAME (constructor_fields) == 0)
5266 constructor_fields = TREE_CHAIN (constructor_fields);
5267
5268 constructor_unfilled_fields = constructor_fields;
5269 constructor_bit_index = bitsize_zero_node;
5270 }
5271 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5272 {
5273 if (TYPE_DOMAIN (constructor_type))
5274 {
5275 constructor_max_index
5276 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5277
5278 /* Detect non-empty initializations of zero-length arrays. */
5279 if (constructor_max_index == NULL_TREE
5280 && TYPE_SIZE (constructor_type))
5281 constructor_max_index = build_int_cst (NULL_TREE, -1);
5282
5283 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5284 to initialize VLAs will cause a proper error; avoid tree
5285 checking errors as well by setting a safe value. */
5286 if (constructor_max_index
5287 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5288 constructor_max_index = build_int_cst (NULL_TREE, -1);
5289
5290 constructor_index
5291 = convert (bitsizetype,
5292 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5293 }
5294 else
5295 {
5296 constructor_index = bitsize_zero_node;
5297 constructor_max_index = NULL_TREE;
5298 }
5299
5300 constructor_unfilled_index = constructor_index;
5301 }
5302 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5303 {
5304 /* Vectors are like simple fixed-size arrays. */
5305 constructor_max_index =
5306 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5307 constructor_index = bitsize_zero_node;
5308 constructor_unfilled_index = constructor_index;
5309 }
5310 else
5311 {
5312 /* Handle the case of int x = {5}; */
5313 constructor_fields = constructor_type;
5314 constructor_unfilled_fields = constructor_type;
5315 }
5316 }
5317 \f
5318 /* Push down into a subobject, for initialization.
5319 If this is for an explicit set of braces, IMPLICIT is 0.
5320 If it is because the next element belongs at a lower level,
5321 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5322
5323 void
5324 push_init_level (int implicit)
5325 {
5326 struct constructor_stack *p;
5327 tree value = NULL_TREE;
5328
5329 /* If we've exhausted any levels that didn't have braces,
5330 pop them now. If implicit == 1, this will have been done in
5331 process_init_element; do not repeat it here because in the case
5332 of excess initializers for an empty aggregate this leads to an
5333 infinite cycle of popping a level and immediately recreating
5334 it. */
5335 if (implicit != 1)
5336 {
5337 while (constructor_stack->implicit)
5338 {
5339 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5340 || TREE_CODE (constructor_type) == UNION_TYPE)
5341 && constructor_fields == 0)
5342 process_init_element (pop_init_level (1));
5343 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5344 && constructor_max_index
5345 && tree_int_cst_lt (constructor_max_index,
5346 constructor_index))
5347 process_init_element (pop_init_level (1));
5348 else
5349 break;
5350 }
5351 }
5352
5353 /* Unless this is an explicit brace, we need to preserve previous
5354 content if any. */
5355 if (implicit)
5356 {
5357 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5358 || TREE_CODE (constructor_type) == UNION_TYPE)
5359 && constructor_fields)
5360 value = find_init_member (constructor_fields);
5361 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5362 value = find_init_member (constructor_index);
5363 }
5364
5365 p = XNEW (struct constructor_stack);
5366 p->type = constructor_type;
5367 p->fields = constructor_fields;
5368 p->index = constructor_index;
5369 p->max_index = constructor_max_index;
5370 p->unfilled_index = constructor_unfilled_index;
5371 p->unfilled_fields = constructor_unfilled_fields;
5372 p->bit_index = constructor_bit_index;
5373 p->elements = constructor_elements;
5374 p->constant = constructor_constant;
5375 p->simple = constructor_simple;
5376 p->erroneous = constructor_erroneous;
5377 p->pending_elts = constructor_pending_elts;
5378 p->depth = constructor_depth;
5379 p->replacement_value.value = 0;
5380 p->replacement_value.original_code = ERROR_MARK;
5381 p->implicit = implicit;
5382 p->outer = 0;
5383 p->incremental = constructor_incremental;
5384 p->designated = constructor_designated;
5385 p->next = constructor_stack;
5386 p->range_stack = 0;
5387 constructor_stack = p;
5388
5389 constructor_constant = 1;
5390 constructor_simple = 1;
5391 constructor_depth = SPELLING_DEPTH ();
5392 constructor_elements = 0;
5393 constructor_incremental = 1;
5394 constructor_designated = 0;
5395 constructor_pending_elts = 0;
5396 if (!implicit)
5397 {
5398 p->range_stack = constructor_range_stack;
5399 constructor_range_stack = 0;
5400 designator_depth = 0;
5401 designator_erroneous = 0;
5402 }
5403
5404 /* Don't die if an entire brace-pair level is superfluous
5405 in the containing level. */
5406 if (constructor_type == 0)
5407 ;
5408 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5409 || TREE_CODE (constructor_type) == UNION_TYPE)
5410 {
5411 /* Don't die if there are extra init elts at the end. */
5412 if (constructor_fields == 0)
5413 constructor_type = 0;
5414 else
5415 {
5416 constructor_type = TREE_TYPE (constructor_fields);
5417 push_member_name (constructor_fields);
5418 constructor_depth++;
5419 }
5420 }
5421 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5422 {
5423 constructor_type = TREE_TYPE (constructor_type);
5424 push_array_bounds (tree_low_cst (constructor_index, 1));
5425 constructor_depth++;
5426 }
5427
5428 if (constructor_type == 0)
5429 {
5430 error_init ("extra brace group at end of initializer");
5431 constructor_fields = 0;
5432 constructor_unfilled_fields = 0;
5433 return;
5434 }
5435
5436 if (value && TREE_CODE (value) == CONSTRUCTOR)
5437 {
5438 constructor_constant = TREE_CONSTANT (value);
5439 constructor_simple = TREE_STATIC (value);
5440 constructor_elements = CONSTRUCTOR_ELTS (value);
5441 if (!VEC_empty (constructor_elt, constructor_elements)
5442 && (TREE_CODE (constructor_type) == RECORD_TYPE
5443 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5444 set_nonincremental_init ();
5445 }
5446
5447 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5448 {
5449 missing_braces_mentioned = 1;
5450 warning_init (OPT_Wmissing_braces, "missing braces around initializer");
5451 }
5452
5453 if (TREE_CODE (constructor_type) == RECORD_TYPE
5454 || TREE_CODE (constructor_type) == UNION_TYPE)
5455 {
5456 constructor_fields = TYPE_FIELDS (constructor_type);
5457 /* Skip any nameless bit fields at the beginning. */
5458 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5459 && DECL_NAME (constructor_fields) == 0)
5460 constructor_fields = TREE_CHAIN (constructor_fields);
5461
5462 constructor_unfilled_fields = constructor_fields;
5463 constructor_bit_index = bitsize_zero_node;
5464 }
5465 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5466 {
5467 /* Vectors are like simple fixed-size arrays. */
5468 constructor_max_index =
5469 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5470 constructor_index = convert (bitsizetype, integer_zero_node);
5471 constructor_unfilled_index = constructor_index;
5472 }
5473 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5474 {
5475 if (TYPE_DOMAIN (constructor_type))
5476 {
5477 constructor_max_index
5478 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5479
5480 /* Detect non-empty initializations of zero-length arrays. */
5481 if (constructor_max_index == NULL_TREE
5482 && TYPE_SIZE (constructor_type))
5483 constructor_max_index = build_int_cst (NULL_TREE, -1);
5484
5485 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5486 to initialize VLAs will cause a proper error; avoid tree
5487 checking errors as well by setting a safe value. */
5488 if (constructor_max_index
5489 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5490 constructor_max_index = build_int_cst (NULL_TREE, -1);
5491
5492 constructor_index
5493 = convert (bitsizetype,
5494 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5495 }
5496 else
5497 constructor_index = bitsize_zero_node;
5498
5499 constructor_unfilled_index = constructor_index;
5500 if (value && TREE_CODE (value) == STRING_CST)
5501 {
5502 /* We need to split the char/wchar array into individual
5503 characters, so that we don't have to special case it
5504 everywhere. */
5505 set_nonincremental_init_from_string (value);
5506 }
5507 }
5508 else
5509 {
5510 if (constructor_type != error_mark_node)
5511 warning_init (0, "braces around scalar initializer");
5512 constructor_fields = constructor_type;
5513 constructor_unfilled_fields = constructor_type;
5514 }
5515 }
5516
5517 /* At the end of an implicit or explicit brace level,
5518 finish up that level of constructor. If a single expression
5519 with redundant braces initialized that level, return the
5520 c_expr structure for that expression. Otherwise, the original_code
5521 element is set to ERROR_MARK.
5522 If we were outputting the elements as they are read, return 0 as the value
5523 from inner levels (process_init_element ignores that),
5524 but return error_mark_node as the value from the outermost level
5525 (that's what we want to put in DECL_INITIAL).
5526 Otherwise, return a CONSTRUCTOR expression as the value. */
5527
5528 struct c_expr
5529 pop_init_level (int implicit)
5530 {
5531 struct constructor_stack *p;
5532 struct c_expr ret;
5533 ret.value = 0;
5534 ret.original_code = ERROR_MARK;
5535
5536 if (implicit == 0)
5537 {
5538 /* When we come to an explicit close brace,
5539 pop any inner levels that didn't have explicit braces. */
5540 while (constructor_stack->implicit)
5541 process_init_element (pop_init_level (1));
5542
5543 gcc_assert (!constructor_range_stack);
5544 }
5545
5546 /* Now output all pending elements. */
5547 constructor_incremental = 1;
5548 output_pending_init_elements (1);
5549
5550 p = constructor_stack;
5551
5552 /* Error for initializing a flexible array member, or a zero-length
5553 array member in an inappropriate context. */
5554 if (constructor_type && constructor_fields
5555 && TREE_CODE (constructor_type) == ARRAY_TYPE
5556 && TYPE_DOMAIN (constructor_type)
5557 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5558 {
5559 /* Silently discard empty initializations. The parser will
5560 already have pedwarned for empty brackets. */
5561 if (integer_zerop (constructor_unfilled_index))
5562 constructor_type = NULL_TREE;
5563 else
5564 {
5565 gcc_assert (!TYPE_SIZE (constructor_type));
5566
5567 if (constructor_depth > 2)
5568 error_init ("initialization of flexible array member in a nested context");
5569 else
5570 pedwarn_init (input_location, OPT_pedantic,
5571 "initialization of a flexible array member");
5572
5573 /* We have already issued an error message for the existence
5574 of a flexible array member not at the end of the structure.
5575 Discard the initializer so that we do not die later. */
5576 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5577 constructor_type = NULL_TREE;
5578 }
5579 }
5580
5581 /* Warn when some struct elements are implicitly initialized to zero. */
5582 if (warn_missing_field_initializers
5583 && constructor_type
5584 && TREE_CODE (constructor_type) == RECORD_TYPE
5585 && constructor_unfilled_fields)
5586 {
5587 /* Do not warn for flexible array members or zero-length arrays. */
5588 while (constructor_unfilled_fields
5589 && (!DECL_SIZE (constructor_unfilled_fields)
5590 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5591 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5592
5593 /* Do not warn if this level of the initializer uses member
5594 designators; it is likely to be deliberate. */
5595 if (constructor_unfilled_fields && !constructor_designated)
5596 {
5597 push_member_name (constructor_unfilled_fields);
5598 warning_init (OPT_Wmissing_field_initializers,
5599 "missing initializer");
5600 RESTORE_SPELLING_DEPTH (constructor_depth);
5601 }
5602 }
5603
5604 /* Pad out the end of the structure. */
5605 if (p->replacement_value.value)
5606 /* If this closes a superfluous brace pair,
5607 just pass out the element between them. */
5608 ret = p->replacement_value;
5609 else if (constructor_type == 0)
5610 ;
5611 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5612 && TREE_CODE (constructor_type) != UNION_TYPE
5613 && TREE_CODE (constructor_type) != ARRAY_TYPE
5614 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5615 {
5616 /* A nonincremental scalar initializer--just return
5617 the element, after verifying there is just one. */
5618 if (VEC_empty (constructor_elt,constructor_elements))
5619 {
5620 if (!constructor_erroneous)
5621 error_init ("empty scalar initializer");
5622 ret.value = error_mark_node;
5623 }
5624 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5625 {
5626 error_init ("extra elements in scalar initializer");
5627 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5628 }
5629 else
5630 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5631 }
5632 else
5633 {
5634 if (constructor_erroneous)
5635 ret.value = error_mark_node;
5636 else
5637 {
5638 ret.value = build_constructor (constructor_type,
5639 constructor_elements);
5640 if (constructor_constant)
5641 TREE_CONSTANT (ret.value) = 1;
5642 if (constructor_constant && constructor_simple)
5643 TREE_STATIC (ret.value) = 1;
5644 }
5645 }
5646
5647 constructor_type = p->type;
5648 constructor_fields = p->fields;
5649 constructor_index = p->index;
5650 constructor_max_index = p->max_index;
5651 constructor_unfilled_index = p->unfilled_index;
5652 constructor_unfilled_fields = p->unfilled_fields;
5653 constructor_bit_index = p->bit_index;
5654 constructor_elements = p->elements;
5655 constructor_constant = p->constant;
5656 constructor_simple = p->simple;
5657 constructor_erroneous = p->erroneous;
5658 constructor_incremental = p->incremental;
5659 constructor_designated = p->designated;
5660 constructor_pending_elts = p->pending_elts;
5661 constructor_depth = p->depth;
5662 if (!p->implicit)
5663 constructor_range_stack = p->range_stack;
5664 RESTORE_SPELLING_DEPTH (constructor_depth);
5665
5666 constructor_stack = p->next;
5667 free (p);
5668
5669 if (ret.value == 0 && constructor_stack == 0)
5670 ret.value = error_mark_node;
5671 return ret;
5672 }
5673
5674 /* Common handling for both array range and field name designators.
5675 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5676
5677 static int
5678 set_designator (int array)
5679 {
5680 tree subtype;
5681 enum tree_code subcode;
5682
5683 /* Don't die if an entire brace-pair level is superfluous
5684 in the containing level. */
5685 if (constructor_type == 0)
5686 return 1;
5687
5688 /* If there were errors in this designator list already, bail out
5689 silently. */
5690 if (designator_erroneous)
5691 return 1;
5692
5693 if (!designator_depth)
5694 {
5695 gcc_assert (!constructor_range_stack);
5696
5697 /* Designator list starts at the level of closest explicit
5698 braces. */
5699 while (constructor_stack->implicit)
5700 process_init_element (pop_init_level (1));
5701 constructor_designated = 1;
5702 return 0;
5703 }
5704
5705 switch (TREE_CODE (constructor_type))
5706 {
5707 case RECORD_TYPE:
5708 case UNION_TYPE:
5709 subtype = TREE_TYPE (constructor_fields);
5710 if (subtype != error_mark_node)
5711 subtype = TYPE_MAIN_VARIANT (subtype);
5712 break;
5713 case ARRAY_TYPE:
5714 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5715 break;
5716 default:
5717 gcc_unreachable ();
5718 }
5719
5720 subcode = TREE_CODE (subtype);
5721 if (array && subcode != ARRAY_TYPE)
5722 {
5723 error_init ("array index in non-array initializer");
5724 return 1;
5725 }
5726 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5727 {
5728 error_init ("field name not in record or union initializer");
5729 return 1;
5730 }
5731
5732 constructor_designated = 1;
5733 push_init_level (2);
5734 return 0;
5735 }
5736
5737 /* If there are range designators in designator list, push a new designator
5738 to constructor_range_stack. RANGE_END is end of such stack range or
5739 NULL_TREE if there is no range designator at this level. */
5740
5741 static void
5742 push_range_stack (tree range_end)
5743 {
5744 struct constructor_range_stack *p;
5745
5746 p = GGC_NEW (struct constructor_range_stack);
5747 p->prev = constructor_range_stack;
5748 p->next = 0;
5749 p->fields = constructor_fields;
5750 p->range_start = constructor_index;
5751 p->index = constructor_index;
5752 p->stack = constructor_stack;
5753 p->range_end = range_end;
5754 if (constructor_range_stack)
5755 constructor_range_stack->next = p;
5756 constructor_range_stack = p;
5757 }
5758
5759 /* Within an array initializer, specify the next index to be initialized.
5760 FIRST is that index. If LAST is nonzero, then initialize a range
5761 of indices, running from FIRST through LAST. */
5762
5763 void
5764 set_init_index (tree first, tree last)
5765 {
5766 if (set_designator (1))
5767 return;
5768
5769 designator_erroneous = 1;
5770
5771 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5772 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5773 {
5774 error_init ("array index in initializer not of integer type");
5775 return;
5776 }
5777
5778 if (TREE_CODE (first) != INTEGER_CST)
5779 error_init ("nonconstant array index in initializer");
5780 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5781 error_init ("nonconstant array index in initializer");
5782 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5783 error_init ("array index in non-array initializer");
5784 else if (tree_int_cst_sgn (first) == -1)
5785 error_init ("array index in initializer exceeds array bounds");
5786 else if (constructor_max_index
5787 && tree_int_cst_lt (constructor_max_index, first))
5788 error_init ("array index in initializer exceeds array bounds");
5789 else
5790 {
5791 constructor_index = convert (bitsizetype, first);
5792
5793 if (last)
5794 {
5795 if (tree_int_cst_equal (first, last))
5796 last = 0;
5797 else if (tree_int_cst_lt (last, first))
5798 {
5799 error_init ("empty index range in initializer");
5800 last = 0;
5801 }
5802 else
5803 {
5804 last = convert (bitsizetype, last);
5805 if (constructor_max_index != 0
5806 && tree_int_cst_lt (constructor_max_index, last))
5807 {
5808 error_init ("array index range in initializer exceeds array bounds");
5809 last = 0;
5810 }
5811 }
5812 }
5813
5814 designator_depth++;
5815 designator_erroneous = 0;
5816 if (constructor_range_stack || last)
5817 push_range_stack (last);
5818 }
5819 }
5820
5821 /* Within a struct initializer, specify the next field to be initialized. */
5822
5823 void
5824 set_init_label (tree fieldname)
5825 {
5826 tree tail;
5827
5828 if (set_designator (0))
5829 return;
5830
5831 designator_erroneous = 1;
5832
5833 if (TREE_CODE (constructor_type) != RECORD_TYPE
5834 && TREE_CODE (constructor_type) != UNION_TYPE)
5835 {
5836 error_init ("field name not in record or union initializer");
5837 return;
5838 }
5839
5840 for (tail = TYPE_FIELDS (constructor_type); tail;
5841 tail = TREE_CHAIN (tail))
5842 {
5843 if (DECL_NAME (tail) == fieldname)
5844 break;
5845 }
5846
5847 if (tail == 0)
5848 error ("unknown field %qE specified in initializer", fieldname);
5849 else
5850 {
5851 constructor_fields = tail;
5852 designator_depth++;
5853 designator_erroneous = 0;
5854 if (constructor_range_stack)
5855 push_range_stack (NULL_TREE);
5856 }
5857 }
5858 \f
5859 /* Add a new initializer to the tree of pending initializers. PURPOSE
5860 identifies the initializer, either array index or field in a structure.
5861 VALUE is the value of that index or field. */
5862
5863 static void
5864 add_pending_init (tree purpose, tree value)
5865 {
5866 struct init_node *p, **q, *r;
5867
5868 q = &constructor_pending_elts;
5869 p = 0;
5870
5871 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5872 {
5873 while (*q != 0)
5874 {
5875 p = *q;
5876 if (tree_int_cst_lt (purpose, p->purpose))
5877 q = &p->left;
5878 else if (tree_int_cst_lt (p->purpose, purpose))
5879 q = &p->right;
5880 else
5881 {
5882 if (TREE_SIDE_EFFECTS (p->value))
5883 warning_init (0, "initialized field with side-effects overwritten");
5884 else if (warn_override_init)
5885 warning_init (OPT_Woverride_init, "initialized field overwritten");
5886 p->value = value;
5887 return;
5888 }
5889 }
5890 }
5891 else
5892 {
5893 tree bitpos;
5894
5895 bitpos = bit_position (purpose);
5896 while (*q != NULL)
5897 {
5898 p = *q;
5899 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5900 q = &p->left;
5901 else if (p->purpose != purpose)
5902 q = &p->right;
5903 else
5904 {
5905 if (TREE_SIDE_EFFECTS (p->value))
5906 warning_init (0, "initialized field with side-effects overwritten");
5907 else if (warn_override_init)
5908 warning_init (OPT_Woverride_init, "initialized field overwritten");
5909 p->value = value;
5910 return;
5911 }
5912 }
5913 }
5914
5915 r = GGC_NEW (struct init_node);
5916 r->purpose = purpose;
5917 r->value = value;
5918
5919 *q = r;
5920 r->parent = p;
5921 r->left = 0;
5922 r->right = 0;
5923 r->balance = 0;
5924
5925 while (p)
5926 {
5927 struct init_node *s;
5928
5929 if (r == p->left)
5930 {
5931 if (p->balance == 0)
5932 p->balance = -1;
5933 else if (p->balance < 0)
5934 {
5935 if (r->balance < 0)
5936 {
5937 /* L rotation. */
5938 p->left = r->right;
5939 if (p->left)
5940 p->left->parent = p;
5941 r->right = p;
5942
5943 p->balance = 0;
5944 r->balance = 0;
5945
5946 s = p->parent;
5947 p->parent = r;
5948 r->parent = s;
5949 if (s)
5950 {
5951 if (s->left == p)
5952 s->left = r;
5953 else
5954 s->right = r;
5955 }
5956 else
5957 constructor_pending_elts = r;
5958 }
5959 else
5960 {
5961 /* LR rotation. */
5962 struct init_node *t = r->right;
5963
5964 r->right = t->left;
5965 if (r->right)
5966 r->right->parent = r;
5967 t->left = r;
5968
5969 p->left = t->right;
5970 if (p->left)
5971 p->left->parent = p;
5972 t->right = p;
5973
5974 p->balance = t->balance < 0;
5975 r->balance = -(t->balance > 0);
5976 t->balance = 0;
5977
5978 s = p->parent;
5979 p->parent = t;
5980 r->parent = t;
5981 t->parent = s;
5982 if (s)
5983 {
5984 if (s->left == p)
5985 s->left = t;
5986 else
5987 s->right = t;
5988 }
5989 else
5990 constructor_pending_elts = t;
5991 }
5992 break;
5993 }
5994 else
5995 {
5996 /* p->balance == +1; growth of left side balances the node. */
5997 p->balance = 0;
5998 break;
5999 }
6000 }
6001 else /* r == p->right */
6002 {
6003 if (p->balance == 0)
6004 /* Growth propagation from right side. */
6005 p->balance++;
6006 else if (p->balance > 0)
6007 {
6008 if (r->balance > 0)
6009 {
6010 /* R rotation. */
6011 p->right = r->left;
6012 if (p->right)
6013 p->right->parent = p;
6014 r->left = p;
6015
6016 p->balance = 0;
6017 r->balance = 0;
6018
6019 s = p->parent;
6020 p->parent = r;
6021 r->parent = s;
6022 if (s)
6023 {
6024 if (s->left == p)
6025 s->left = r;
6026 else
6027 s->right = r;
6028 }
6029 else
6030 constructor_pending_elts = r;
6031 }
6032 else /* r->balance == -1 */
6033 {
6034 /* RL rotation */
6035 struct init_node *t = r->left;
6036
6037 r->left = t->right;
6038 if (r->left)
6039 r->left->parent = r;
6040 t->right = r;
6041
6042 p->right = t->left;
6043 if (p->right)
6044 p->right->parent = p;
6045 t->left = p;
6046
6047 r->balance = (t->balance < 0);
6048 p->balance = -(t->balance > 0);
6049 t->balance = 0;
6050
6051 s = p->parent;
6052 p->parent = t;
6053 r->parent = t;
6054 t->parent = s;
6055 if (s)
6056 {
6057 if (s->left == p)
6058 s->left = t;
6059 else
6060 s->right = t;
6061 }
6062 else
6063 constructor_pending_elts = t;
6064 }
6065 break;
6066 }
6067 else
6068 {
6069 /* p->balance == -1; growth of right side balances the node. */
6070 p->balance = 0;
6071 break;
6072 }
6073 }
6074
6075 r = p;
6076 p = p->parent;
6077 }
6078 }
6079
6080 /* Build AVL tree from a sorted chain. */
6081
6082 static void
6083 set_nonincremental_init (void)
6084 {
6085 unsigned HOST_WIDE_INT ix;
6086 tree index, value;
6087
6088 if (TREE_CODE (constructor_type) != RECORD_TYPE
6089 && TREE_CODE (constructor_type) != ARRAY_TYPE)
6090 return;
6091
6092 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
6093 add_pending_init (index, value);
6094 constructor_elements = 0;
6095 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6096 {
6097 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
6098 /* Skip any nameless bit fields at the beginning. */
6099 while (constructor_unfilled_fields != 0
6100 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6101 && DECL_NAME (constructor_unfilled_fields) == 0)
6102 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
6103
6104 }
6105 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6106 {
6107 if (TYPE_DOMAIN (constructor_type))
6108 constructor_unfilled_index
6109 = convert (bitsizetype,
6110 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
6111 else
6112 constructor_unfilled_index = bitsize_zero_node;
6113 }
6114 constructor_incremental = 0;
6115 }
6116
6117 /* Build AVL tree from a string constant. */
6118
6119 static void
6120 set_nonincremental_init_from_string (tree str)
6121 {
6122 tree value, purpose, type;
6123 HOST_WIDE_INT val[2];
6124 const char *p, *end;
6125 int byte, wchar_bytes, charwidth, bitpos;
6126
6127 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
6128
6129 wchar_bytes = TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) / BITS_PER_UNIT;
6130 charwidth = TYPE_PRECISION (char_type_node);
6131 type = TREE_TYPE (constructor_type);
6132 p = TREE_STRING_POINTER (str);
6133 end = p + TREE_STRING_LENGTH (str);
6134
6135 for (purpose = bitsize_zero_node;
6136 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6137 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6138 {
6139 if (wchar_bytes == 1)
6140 {
6141 val[1] = (unsigned char) *p++;
6142 val[0] = 0;
6143 }
6144 else
6145 {
6146 val[0] = 0;
6147 val[1] = 0;
6148 for (byte = 0; byte < wchar_bytes; byte++)
6149 {
6150 if (BYTES_BIG_ENDIAN)
6151 bitpos = (wchar_bytes - byte - 1) * charwidth;
6152 else
6153 bitpos = byte * charwidth;
6154 val[bitpos < HOST_BITS_PER_WIDE_INT]
6155 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6156 << (bitpos % HOST_BITS_PER_WIDE_INT);
6157 }
6158 }
6159
6160 if (!TYPE_UNSIGNED (type))
6161 {
6162 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6163 if (bitpos < HOST_BITS_PER_WIDE_INT)
6164 {
6165 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6166 {
6167 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6168 val[0] = -1;
6169 }
6170 }
6171 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6172 {
6173 if (val[1] < 0)
6174 val[0] = -1;
6175 }
6176 else if (val[0] & (((HOST_WIDE_INT) 1)
6177 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6178 val[0] |= ((HOST_WIDE_INT) -1)
6179 << (bitpos - HOST_BITS_PER_WIDE_INT);
6180 }
6181
6182 value = build_int_cst_wide (type, val[1], val[0]);
6183 add_pending_init (purpose, value);
6184 }
6185
6186 constructor_incremental = 0;
6187 }
6188
6189 /* Return value of FIELD in pending initializer or zero if the field was
6190 not initialized yet. */
6191
6192 static tree
6193 find_init_member (tree field)
6194 {
6195 struct init_node *p;
6196
6197 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6198 {
6199 if (constructor_incremental
6200 && tree_int_cst_lt (field, constructor_unfilled_index))
6201 set_nonincremental_init ();
6202
6203 p = constructor_pending_elts;
6204 while (p)
6205 {
6206 if (tree_int_cst_lt (field, p->purpose))
6207 p = p->left;
6208 else if (tree_int_cst_lt (p->purpose, field))
6209 p = p->right;
6210 else
6211 return p->value;
6212 }
6213 }
6214 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6215 {
6216 tree bitpos = bit_position (field);
6217
6218 if (constructor_incremental
6219 && (!constructor_unfilled_fields
6220 || tree_int_cst_lt (bitpos,
6221 bit_position (constructor_unfilled_fields))))
6222 set_nonincremental_init ();
6223
6224 p = constructor_pending_elts;
6225 while (p)
6226 {
6227 if (field == p->purpose)
6228 return p->value;
6229 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6230 p = p->left;
6231 else
6232 p = p->right;
6233 }
6234 }
6235 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6236 {
6237 if (!VEC_empty (constructor_elt, constructor_elements)
6238 && (VEC_last (constructor_elt, constructor_elements)->index
6239 == field))
6240 return VEC_last (constructor_elt, constructor_elements)->value;
6241 }
6242 return 0;
6243 }
6244
6245 /* "Output" the next constructor element.
6246 At top level, really output it to assembler code now.
6247 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6248 TYPE is the data type that the containing data type wants here.
6249 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6250 If VALUE is a string constant, STRICT_STRING is true if it is
6251 unparenthesized or we should not warn here for it being parenthesized.
6252 For other types of VALUE, STRICT_STRING is not used.
6253
6254 PENDING if non-nil means output pending elements that belong
6255 right after this element. (PENDING is normally 1;
6256 it is 0 while outputting pending elements, to avoid recursion.) */
6257
6258 static void
6259 output_init_element (tree value, bool strict_string, tree type, tree field,
6260 int pending)
6261 {
6262 constructor_elt *celt;
6263
6264 if (type == error_mark_node || value == error_mark_node)
6265 {
6266 constructor_erroneous = 1;
6267 return;
6268 }
6269 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6270 && (TREE_CODE (value) == STRING_CST
6271 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6272 && !(TREE_CODE (value) == STRING_CST
6273 && TREE_CODE (type) == ARRAY_TYPE
6274 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6275 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6276 TYPE_MAIN_VARIANT (type)))
6277 value = array_to_pointer_conversion (value);
6278
6279 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6280 && require_constant_value && !flag_isoc99 && pending)
6281 {
6282 /* As an extension, allow initializing objects with static storage
6283 duration with compound literals (which are then treated just as
6284 the brace enclosed list they contain). */
6285 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6286 value = DECL_INITIAL (decl);
6287 }
6288
6289 if (value == error_mark_node)
6290 constructor_erroneous = 1;
6291 else if (!TREE_CONSTANT (value))
6292 constructor_constant = 0;
6293 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6294 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6295 || TREE_CODE (constructor_type) == UNION_TYPE)
6296 && DECL_C_BIT_FIELD (field)
6297 && TREE_CODE (value) != INTEGER_CST))
6298 constructor_simple = 0;
6299
6300 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6301 {
6302 if (require_constant_value)
6303 {
6304 error_init ("initializer element is not constant");
6305 value = error_mark_node;
6306 }
6307 else if (require_constant_elements)
6308 pedwarn (input_location, 0,
6309 "initializer element is not computable at load time");
6310 }
6311
6312 /* If this field is empty (and not at the end of structure),
6313 don't do anything other than checking the initializer. */
6314 if (field
6315 && (TREE_TYPE (field) == error_mark_node
6316 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6317 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6318 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6319 || TREE_CHAIN (field)))))
6320 return;
6321
6322 value = digest_init (type, value, strict_string, require_constant_value);
6323 if (value == error_mark_node)
6324 {
6325 constructor_erroneous = 1;
6326 return;
6327 }
6328
6329 /* If this element doesn't come next in sequence,
6330 put it on constructor_pending_elts. */
6331 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6332 && (!constructor_incremental
6333 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6334 {
6335 if (constructor_incremental
6336 && tree_int_cst_lt (field, constructor_unfilled_index))
6337 set_nonincremental_init ();
6338
6339 add_pending_init (field, value);
6340 return;
6341 }
6342 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6343 && (!constructor_incremental
6344 || field != constructor_unfilled_fields))
6345 {
6346 /* We do this for records but not for unions. In a union,
6347 no matter which field is specified, it can be initialized
6348 right away since it starts at the beginning of the union. */
6349 if (constructor_incremental)
6350 {
6351 if (!constructor_unfilled_fields)
6352 set_nonincremental_init ();
6353 else
6354 {
6355 tree bitpos, unfillpos;
6356
6357 bitpos = bit_position (field);
6358 unfillpos = bit_position (constructor_unfilled_fields);
6359
6360 if (tree_int_cst_lt (bitpos, unfillpos))
6361 set_nonincremental_init ();
6362 }
6363 }
6364
6365 add_pending_init (field, value);
6366 return;
6367 }
6368 else if (TREE_CODE (constructor_type) == UNION_TYPE
6369 && !VEC_empty (constructor_elt, constructor_elements))
6370 {
6371 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6372 constructor_elements)->value))
6373 warning_init (0, "initialized field with side-effects overwritten");
6374 else if (warn_override_init)
6375 warning_init (OPT_Woverride_init, "initialized field overwritten");
6376
6377 /* We can have just one union field set. */
6378 constructor_elements = 0;
6379 }
6380
6381 /* Otherwise, output this element either to
6382 constructor_elements or to the assembler file. */
6383
6384 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6385 celt->index = field;
6386 celt->value = value;
6387
6388 /* Advance the variable that indicates sequential elements output. */
6389 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6390 constructor_unfilled_index
6391 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6392 bitsize_one_node);
6393 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6394 {
6395 constructor_unfilled_fields
6396 = TREE_CHAIN (constructor_unfilled_fields);
6397
6398 /* Skip any nameless bit fields. */
6399 while (constructor_unfilled_fields != 0
6400 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6401 && DECL_NAME (constructor_unfilled_fields) == 0)
6402 constructor_unfilled_fields =
6403 TREE_CHAIN (constructor_unfilled_fields);
6404 }
6405 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6406 constructor_unfilled_fields = 0;
6407
6408 /* Now output any pending elements which have become next. */
6409 if (pending)
6410 output_pending_init_elements (0);
6411 }
6412
6413 /* Output any pending elements which have become next.
6414 As we output elements, constructor_unfilled_{fields,index}
6415 advances, which may cause other elements to become next;
6416 if so, they too are output.
6417
6418 If ALL is 0, we return when there are
6419 no more pending elements to output now.
6420
6421 If ALL is 1, we output space as necessary so that
6422 we can output all the pending elements. */
6423
6424 static void
6425 output_pending_init_elements (int all)
6426 {
6427 struct init_node *elt = constructor_pending_elts;
6428 tree next;
6429
6430 retry:
6431
6432 /* Look through the whole pending tree.
6433 If we find an element that should be output now,
6434 output it. Otherwise, set NEXT to the element
6435 that comes first among those still pending. */
6436
6437 next = 0;
6438 while (elt)
6439 {
6440 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6441 {
6442 if (tree_int_cst_equal (elt->purpose,
6443 constructor_unfilled_index))
6444 output_init_element (elt->value, true,
6445 TREE_TYPE (constructor_type),
6446 constructor_unfilled_index, 0);
6447 else if (tree_int_cst_lt (constructor_unfilled_index,
6448 elt->purpose))
6449 {
6450 /* Advance to the next smaller node. */
6451 if (elt->left)
6452 elt = elt->left;
6453 else
6454 {
6455 /* We have reached the smallest node bigger than the
6456 current unfilled index. Fill the space first. */
6457 next = elt->purpose;
6458 break;
6459 }
6460 }
6461 else
6462 {
6463 /* Advance to the next bigger node. */
6464 if (elt->right)
6465 elt = elt->right;
6466 else
6467 {
6468 /* We have reached the biggest node in a subtree. Find
6469 the parent of it, which is the next bigger node. */
6470 while (elt->parent && elt->parent->right == elt)
6471 elt = elt->parent;
6472 elt = elt->parent;
6473 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6474 elt->purpose))
6475 {
6476 next = elt->purpose;
6477 break;
6478 }
6479 }
6480 }
6481 }
6482 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6483 || TREE_CODE (constructor_type) == UNION_TYPE)
6484 {
6485 tree ctor_unfilled_bitpos, elt_bitpos;
6486
6487 /* If the current record is complete we are done. */
6488 if (constructor_unfilled_fields == 0)
6489 break;
6490
6491 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6492 elt_bitpos = bit_position (elt->purpose);
6493 /* We can't compare fields here because there might be empty
6494 fields in between. */
6495 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6496 {
6497 constructor_unfilled_fields = elt->purpose;
6498 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6499 elt->purpose, 0);
6500 }
6501 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6502 {
6503 /* Advance to the next smaller node. */
6504 if (elt->left)
6505 elt = elt->left;
6506 else
6507 {
6508 /* We have reached the smallest node bigger than the
6509 current unfilled field. Fill the space first. */
6510 next = elt->purpose;
6511 break;
6512 }
6513 }
6514 else
6515 {
6516 /* Advance to the next bigger node. */
6517 if (elt->right)
6518 elt = elt->right;
6519 else
6520 {
6521 /* We have reached the biggest node in a subtree. Find
6522 the parent of it, which is the next bigger node. */
6523 while (elt->parent && elt->parent->right == elt)
6524 elt = elt->parent;
6525 elt = elt->parent;
6526 if (elt
6527 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6528 bit_position (elt->purpose))))
6529 {
6530 next = elt->purpose;
6531 break;
6532 }
6533 }
6534 }
6535 }
6536 }
6537
6538 /* Ordinarily return, but not if we want to output all
6539 and there are elements left. */
6540 if (!(all && next != 0))
6541 return;
6542
6543 /* If it's not incremental, just skip over the gap, so that after
6544 jumping to retry we will output the next successive element. */
6545 if (TREE_CODE (constructor_type) == RECORD_TYPE
6546 || TREE_CODE (constructor_type) == UNION_TYPE)
6547 constructor_unfilled_fields = next;
6548 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6549 constructor_unfilled_index = next;
6550
6551 /* ELT now points to the node in the pending tree with the next
6552 initializer to output. */
6553 goto retry;
6554 }
6555 \f
6556 /* Add one non-braced element to the current constructor level.
6557 This adjusts the current position within the constructor's type.
6558 This may also start or terminate implicit levels
6559 to handle a partly-braced initializer.
6560
6561 Once this has found the correct level for the new element,
6562 it calls output_init_element. */
6563
6564 void
6565 process_init_element (struct c_expr value)
6566 {
6567 tree orig_value = value.value;
6568 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6569 bool strict_string = value.original_code == STRING_CST;
6570
6571 designator_depth = 0;
6572 designator_erroneous = 0;
6573
6574 /* Handle superfluous braces around string cst as in
6575 char x[] = {"foo"}; */
6576 if (string_flag
6577 && constructor_type
6578 && TREE_CODE (constructor_type) == ARRAY_TYPE
6579 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6580 && integer_zerop (constructor_unfilled_index))
6581 {
6582 if (constructor_stack->replacement_value.value)
6583 error_init ("excess elements in char array initializer");
6584 constructor_stack->replacement_value = value;
6585 return;
6586 }
6587
6588 if (constructor_stack->replacement_value.value != 0)
6589 {
6590 error_init ("excess elements in struct initializer");
6591 return;
6592 }
6593
6594 /* Ignore elements of a brace group if it is entirely superfluous
6595 and has already been diagnosed. */
6596 if (constructor_type == 0)
6597 return;
6598
6599 /* If we've exhausted any levels that didn't have braces,
6600 pop them now. */
6601 while (constructor_stack->implicit)
6602 {
6603 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6604 || TREE_CODE (constructor_type) == UNION_TYPE)
6605 && constructor_fields == 0)
6606 process_init_element (pop_init_level (1));
6607 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6608 && (constructor_max_index == 0
6609 || tree_int_cst_lt (constructor_max_index,
6610 constructor_index)))
6611 process_init_element (pop_init_level (1));
6612 else
6613 break;
6614 }
6615
6616 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6617 if (constructor_range_stack)
6618 {
6619 /* If value is a compound literal and we'll be just using its
6620 content, don't put it into a SAVE_EXPR. */
6621 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6622 || !require_constant_value
6623 || flag_isoc99)
6624 value.value = save_expr (value.value);
6625 }
6626
6627 while (1)
6628 {
6629 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6630 {
6631 tree fieldtype;
6632 enum tree_code fieldcode;
6633
6634 if (constructor_fields == 0)
6635 {
6636 pedwarn_init (input_location, 0,
6637 "excess elements in struct initializer");
6638 break;
6639 }
6640
6641 fieldtype = TREE_TYPE (constructor_fields);
6642 if (fieldtype != error_mark_node)
6643 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6644 fieldcode = TREE_CODE (fieldtype);
6645
6646 /* Error for non-static initialization of a flexible array member. */
6647 if (fieldcode == ARRAY_TYPE
6648 && !require_constant_value
6649 && TYPE_SIZE (fieldtype) == NULL_TREE
6650 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6651 {
6652 error_init ("non-static initialization of a flexible array member");
6653 break;
6654 }
6655
6656 /* Accept a string constant to initialize a subarray. */
6657 if (value.value != 0
6658 && fieldcode == ARRAY_TYPE
6659 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6660 && string_flag)
6661 value.value = orig_value;
6662 /* Otherwise, if we have come to a subaggregate,
6663 and we don't have an element of its type, push into it. */
6664 else if (value.value != 0
6665 && value.value != error_mark_node
6666 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6667 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6668 || fieldcode == UNION_TYPE))
6669 {
6670 push_init_level (1);
6671 continue;
6672 }
6673
6674 if (value.value)
6675 {
6676 push_member_name (constructor_fields);
6677 output_init_element (value.value, strict_string,
6678 fieldtype, constructor_fields, 1);
6679 RESTORE_SPELLING_DEPTH (constructor_depth);
6680 }
6681 else
6682 /* Do the bookkeeping for an element that was
6683 directly output as a constructor. */
6684 {
6685 /* For a record, keep track of end position of last field. */
6686 if (DECL_SIZE (constructor_fields))
6687 constructor_bit_index
6688 = size_binop (PLUS_EXPR,
6689 bit_position (constructor_fields),
6690 DECL_SIZE (constructor_fields));
6691
6692 /* If the current field was the first one not yet written out,
6693 it isn't now, so update. */
6694 if (constructor_unfilled_fields == constructor_fields)
6695 {
6696 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6697 /* Skip any nameless bit fields. */
6698 while (constructor_unfilled_fields != 0
6699 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6700 && DECL_NAME (constructor_unfilled_fields) == 0)
6701 constructor_unfilled_fields =
6702 TREE_CHAIN (constructor_unfilled_fields);
6703 }
6704 }
6705
6706 constructor_fields = TREE_CHAIN (constructor_fields);
6707 /* Skip any nameless bit fields at the beginning. */
6708 while (constructor_fields != 0
6709 && DECL_C_BIT_FIELD (constructor_fields)
6710 && DECL_NAME (constructor_fields) == 0)
6711 constructor_fields = TREE_CHAIN (constructor_fields);
6712 }
6713 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6714 {
6715 tree fieldtype;
6716 enum tree_code fieldcode;
6717
6718 if (constructor_fields == 0)
6719 {
6720 pedwarn_init (input_location, 0,
6721 "excess elements in union initializer");
6722 break;
6723 }
6724
6725 fieldtype = TREE_TYPE (constructor_fields);
6726 if (fieldtype != error_mark_node)
6727 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6728 fieldcode = TREE_CODE (fieldtype);
6729
6730 /* Warn that traditional C rejects initialization of unions.
6731 We skip the warning if the value is zero. This is done
6732 under the assumption that the zero initializer in user
6733 code appears conditioned on e.g. __STDC__ to avoid
6734 "missing initializer" warnings and relies on default
6735 initialization to zero in the traditional C case.
6736 We also skip the warning if the initializer is designated,
6737 again on the assumption that this must be conditional on
6738 __STDC__ anyway (and we've already complained about the
6739 member-designator already). */
6740 if (!in_system_header && !constructor_designated
6741 && !(value.value && (integer_zerop (value.value)
6742 || real_zerop (value.value))))
6743 warning (OPT_Wtraditional, "traditional C rejects initialization "
6744 "of unions");
6745
6746 /* Accept a string constant to initialize a subarray. */
6747 if (value.value != 0
6748 && fieldcode == ARRAY_TYPE
6749 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6750 && string_flag)
6751 value.value = orig_value;
6752 /* Otherwise, if we have come to a subaggregate,
6753 and we don't have an element of its type, push into it. */
6754 else if (value.value != 0
6755 && value.value != error_mark_node
6756 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6757 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6758 || fieldcode == UNION_TYPE))
6759 {
6760 push_init_level (1);
6761 continue;
6762 }
6763
6764 if (value.value)
6765 {
6766 push_member_name (constructor_fields);
6767 output_init_element (value.value, strict_string,
6768 fieldtype, constructor_fields, 1);
6769 RESTORE_SPELLING_DEPTH (constructor_depth);
6770 }
6771 else
6772 /* Do the bookkeeping for an element that was
6773 directly output as a constructor. */
6774 {
6775 constructor_bit_index = DECL_SIZE (constructor_fields);
6776 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6777 }
6778
6779 constructor_fields = 0;
6780 }
6781 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6782 {
6783 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6784 enum tree_code eltcode = TREE_CODE (elttype);
6785
6786 /* Accept a string constant to initialize a subarray. */
6787 if (value.value != 0
6788 && eltcode == ARRAY_TYPE
6789 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6790 && string_flag)
6791 value.value = orig_value;
6792 /* Otherwise, if we have come to a subaggregate,
6793 and we don't have an element of its type, push into it. */
6794 else if (value.value != 0
6795 && value.value != error_mark_node
6796 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6797 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6798 || eltcode == UNION_TYPE))
6799 {
6800 push_init_level (1);
6801 continue;
6802 }
6803
6804 if (constructor_max_index != 0
6805 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6806 || integer_all_onesp (constructor_max_index)))
6807 {
6808 pedwarn_init (input_location, 0,
6809 "excess elements in array initializer");
6810 break;
6811 }
6812
6813 /* Now output the actual element. */
6814 if (value.value)
6815 {
6816 push_array_bounds (tree_low_cst (constructor_index, 1));
6817 output_init_element (value.value, strict_string,
6818 elttype, constructor_index, 1);
6819 RESTORE_SPELLING_DEPTH (constructor_depth);
6820 }
6821
6822 constructor_index
6823 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6824
6825 if (!value.value)
6826 /* If we are doing the bookkeeping for an element that was
6827 directly output as a constructor, we must update
6828 constructor_unfilled_index. */
6829 constructor_unfilled_index = constructor_index;
6830 }
6831 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6832 {
6833 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6834
6835 /* Do a basic check of initializer size. Note that vectors
6836 always have a fixed size derived from their type. */
6837 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6838 {
6839 pedwarn_init (input_location, 0,
6840 "excess elements in vector initializer");
6841 break;
6842 }
6843
6844 /* Now output the actual element. */
6845 if (value.value)
6846 output_init_element (value.value, strict_string,
6847 elttype, constructor_index, 1);
6848
6849 constructor_index
6850 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6851
6852 if (!value.value)
6853 /* If we are doing the bookkeeping for an element that was
6854 directly output as a constructor, we must update
6855 constructor_unfilled_index. */
6856 constructor_unfilled_index = constructor_index;
6857 }
6858
6859 /* Handle the sole element allowed in a braced initializer
6860 for a scalar variable. */
6861 else if (constructor_type != error_mark_node
6862 && constructor_fields == 0)
6863 {
6864 pedwarn_init (input_location, 0,
6865 "excess elements in scalar initializer");
6866 break;
6867 }
6868 else
6869 {
6870 if (value.value)
6871 output_init_element (value.value, strict_string,
6872 constructor_type, NULL_TREE, 1);
6873 constructor_fields = 0;
6874 }
6875
6876 /* Handle range initializers either at this level or anywhere higher
6877 in the designator stack. */
6878 if (constructor_range_stack)
6879 {
6880 struct constructor_range_stack *p, *range_stack;
6881 int finish = 0;
6882
6883 range_stack = constructor_range_stack;
6884 constructor_range_stack = 0;
6885 while (constructor_stack != range_stack->stack)
6886 {
6887 gcc_assert (constructor_stack->implicit);
6888 process_init_element (pop_init_level (1));
6889 }
6890 for (p = range_stack;
6891 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6892 p = p->prev)
6893 {
6894 gcc_assert (constructor_stack->implicit);
6895 process_init_element (pop_init_level (1));
6896 }
6897
6898 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6899 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6900 finish = 1;
6901
6902 while (1)
6903 {
6904 constructor_index = p->index;
6905 constructor_fields = p->fields;
6906 if (finish && p->range_end && p->index == p->range_start)
6907 {
6908 finish = 0;
6909 p->prev = 0;
6910 }
6911 p = p->next;
6912 if (!p)
6913 break;
6914 push_init_level (2);
6915 p->stack = constructor_stack;
6916 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6917 p->index = p->range_start;
6918 }
6919
6920 if (!finish)
6921 constructor_range_stack = range_stack;
6922 continue;
6923 }
6924
6925 break;
6926 }
6927
6928 constructor_range_stack = 0;
6929 }
6930 \f
6931 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6932 (guaranteed to be 'volatile' or null) and ARGS (represented using
6933 an ASM_EXPR node). */
6934 tree
6935 build_asm_stmt (tree cv_qualifier, tree args)
6936 {
6937 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6938 ASM_VOLATILE_P (args) = 1;
6939 return add_stmt (args);
6940 }
6941
6942 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6943 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6944 SIMPLE indicates whether there was anything at all after the
6945 string in the asm expression -- asm("blah") and asm("blah" : )
6946 are subtly different. We use a ASM_EXPR node to represent this. */
6947 tree
6948 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6949 bool simple)
6950 {
6951 tree tail;
6952 tree args;
6953 int i;
6954 const char *constraint;
6955 const char **oconstraints;
6956 bool allows_mem, allows_reg, is_inout;
6957 int ninputs, noutputs;
6958
6959 ninputs = list_length (inputs);
6960 noutputs = list_length (outputs);
6961 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6962
6963 string = resolve_asm_operand_names (string, outputs, inputs);
6964
6965 /* Remove output conversions that change the type but not the mode. */
6966 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6967 {
6968 tree output = TREE_VALUE (tail);
6969
6970 /* ??? Really, this should not be here. Users should be using a
6971 proper lvalue, dammit. But there's a long history of using casts
6972 in the output operands. In cases like longlong.h, this becomes a
6973 primitive form of typechecking -- if the cast can be removed, then
6974 the output operand had a type of the proper width; otherwise we'll
6975 get an error. Gross, but ... */
6976 STRIP_NOPS (output);
6977
6978 if (!lvalue_or_else (output, lv_asm))
6979 output = error_mark_node;
6980
6981 if (output != error_mark_node
6982 && (TREE_READONLY (output)
6983 || TYPE_READONLY (TREE_TYPE (output))
6984 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6985 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6986 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6987 readonly_error (output, lv_asm);
6988
6989 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6990 oconstraints[i] = constraint;
6991
6992 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6993 &allows_mem, &allows_reg, &is_inout))
6994 {
6995 /* If the operand is going to end up in memory,
6996 mark it addressable. */
6997 if (!allows_reg && !c_mark_addressable (output))
6998 output = error_mark_node;
6999 }
7000 else
7001 output = error_mark_node;
7002
7003 TREE_VALUE (tail) = output;
7004 }
7005
7006 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
7007 {
7008 tree input;
7009
7010 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
7011 input = TREE_VALUE (tail);
7012
7013 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
7014 oconstraints, &allows_mem, &allows_reg))
7015 {
7016 /* If the operand is going to end up in memory,
7017 mark it addressable. */
7018 if (!allows_reg && allows_mem)
7019 {
7020 /* Strip the nops as we allow this case. FIXME, this really
7021 should be rejected or made deprecated. */
7022 STRIP_NOPS (input);
7023 if (!c_mark_addressable (input))
7024 input = error_mark_node;
7025 }
7026 }
7027 else
7028 input = error_mark_node;
7029
7030 TREE_VALUE (tail) = input;
7031 }
7032
7033 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
7034
7035 /* asm statements without outputs, including simple ones, are treated
7036 as volatile. */
7037 ASM_INPUT_P (args) = simple;
7038 ASM_VOLATILE_P (args) = (noutputs == 0);
7039
7040 return args;
7041 }
7042 \f
7043 /* Generate a goto statement to LABEL. */
7044
7045 tree
7046 c_finish_goto_label (tree label)
7047 {
7048 tree decl = lookup_label (label);
7049 if (!decl)
7050 return NULL_TREE;
7051
7052 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
7053 {
7054 error ("jump into statement expression");
7055 return NULL_TREE;
7056 }
7057
7058 if (C_DECL_UNJUMPABLE_VM (decl))
7059 {
7060 error ("jump into scope of identifier with variably modified type");
7061 return NULL_TREE;
7062 }
7063
7064 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
7065 {
7066 /* No jump from outside this statement expression context, so
7067 record that there is a jump from within this context. */
7068 struct c_label_list *nlist;
7069 nlist = XOBNEW (&parser_obstack, struct c_label_list);
7070 nlist->next = label_context_stack_se->labels_used;
7071 nlist->label = decl;
7072 label_context_stack_se->labels_used = nlist;
7073 }
7074
7075 if (!C_DECL_UNDEFINABLE_VM (decl))
7076 {
7077 /* No jump from outside this context context of identifiers with
7078 variably modified type, so record that there is a jump from
7079 within this context. */
7080 struct c_label_list *nlist;
7081 nlist = XOBNEW (&parser_obstack, struct c_label_list);
7082 nlist->next = label_context_stack_vm->labels_used;
7083 nlist->label = decl;
7084 label_context_stack_vm->labels_used = nlist;
7085 }
7086
7087 TREE_USED (decl) = 1;
7088 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
7089 }
7090
7091 /* Generate a computed goto statement to EXPR. */
7092
7093 tree
7094 c_finish_goto_ptr (tree expr)
7095 {
7096 pedwarn (input_location, OPT_pedantic, "ISO C forbids %<goto *expr;%>");
7097 expr = convert (ptr_type_node, expr);
7098 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
7099 }
7100
7101 /* Generate a C `return' statement. RETVAL is the expression for what
7102 to return, or a null pointer for `return;' with no value. */
7103
7104 tree
7105 c_finish_return (tree retval)
7106 {
7107 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
7108 bool no_warning = false;
7109
7110 if (TREE_THIS_VOLATILE (current_function_decl))
7111 warning (0, "function declared %<noreturn%> has a %<return%> statement");
7112
7113 if (!retval)
7114 {
7115 current_function_returns_null = 1;
7116 if ((warn_return_type || flag_isoc99)
7117 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
7118 {
7119 pedwarn_c99 (input_location, flag_isoc99 ? 0 : OPT_Wreturn_type,
7120 "%<return%> with no value, in "
7121 "function returning non-void");
7122 no_warning = true;
7123 }
7124 }
7125 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
7126 {
7127 current_function_returns_null = 1;
7128 if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
7129 pedwarn (input_location, 0,
7130 "%<return%> with a value, in function returning void");
7131 else
7132 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
7133 "%<return%> with expression, in function returning void");
7134 }
7135 else
7136 {
7137 tree t = convert_for_assignment (valtype, retval, ic_return,
7138 NULL_TREE, NULL_TREE, 0);
7139 tree res = DECL_RESULT (current_function_decl);
7140 tree inner;
7141
7142 current_function_returns_value = 1;
7143 if (t == error_mark_node)
7144 return NULL_TREE;
7145
7146 inner = t = convert (TREE_TYPE (res), t);
7147
7148 /* Strip any conversions, additions, and subtractions, and see if
7149 we are returning the address of a local variable. Warn if so. */
7150 while (1)
7151 {
7152 switch (TREE_CODE (inner))
7153 {
7154 CASE_CONVERT: case NON_LVALUE_EXPR:
7155 case PLUS_EXPR:
7156 inner = TREE_OPERAND (inner, 0);
7157 continue;
7158
7159 case MINUS_EXPR:
7160 /* If the second operand of the MINUS_EXPR has a pointer
7161 type (or is converted from it), this may be valid, so
7162 don't give a warning. */
7163 {
7164 tree op1 = TREE_OPERAND (inner, 1);
7165
7166 while (!POINTER_TYPE_P (TREE_TYPE (op1))
7167 && (CONVERT_EXPR_P (op1)
7168 || TREE_CODE (op1) == NON_LVALUE_EXPR))
7169 op1 = TREE_OPERAND (op1, 0);
7170
7171 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7172 break;
7173
7174 inner = TREE_OPERAND (inner, 0);
7175 continue;
7176 }
7177
7178 case ADDR_EXPR:
7179 inner = TREE_OPERAND (inner, 0);
7180
7181 while (REFERENCE_CLASS_P (inner)
7182 && TREE_CODE (inner) != INDIRECT_REF)
7183 inner = TREE_OPERAND (inner, 0);
7184
7185 if (DECL_P (inner)
7186 && !DECL_EXTERNAL (inner)
7187 && !TREE_STATIC (inner)
7188 && DECL_CONTEXT (inner) == current_function_decl)
7189 warning (0, "function returns address of local variable");
7190 break;
7191
7192 default:
7193 break;
7194 }
7195
7196 break;
7197 }
7198
7199 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7200
7201 if (warn_sequence_point)
7202 verify_sequence_points (retval);
7203 }
7204
7205 ret_stmt = build_stmt (RETURN_EXPR, retval);
7206 TREE_NO_WARNING (ret_stmt) |= no_warning;
7207 return add_stmt (ret_stmt);
7208 }
7209 \f
7210 struct c_switch {
7211 /* The SWITCH_EXPR being built. */
7212 tree switch_expr;
7213
7214 /* The original type of the testing expression, i.e. before the
7215 default conversion is applied. */
7216 tree orig_type;
7217
7218 /* A splay-tree mapping the low element of a case range to the high
7219 element, or NULL_TREE if there is no high element. Used to
7220 determine whether or not a new case label duplicates an old case
7221 label. We need a tree, rather than simply a hash table, because
7222 of the GNU case range extension. */
7223 splay_tree cases;
7224
7225 /* Number of nested statement expressions within this switch
7226 statement; if nonzero, case and default labels may not
7227 appear. */
7228 unsigned int blocked_stmt_expr;
7229
7230 /* Scope of outermost declarations of identifiers with variably
7231 modified type within this switch statement; if nonzero, case and
7232 default labels may not appear. */
7233 unsigned int blocked_vm;
7234
7235 /* The next node on the stack. */
7236 struct c_switch *next;
7237 };
7238
7239 /* A stack of the currently active switch statements. The innermost
7240 switch statement is on the top of the stack. There is no need to
7241 mark the stack for garbage collection because it is only active
7242 during the processing of the body of a function, and we never
7243 collect at that point. */
7244
7245 struct c_switch *c_switch_stack;
7246
7247 /* Start a C switch statement, testing expression EXP. Return the new
7248 SWITCH_EXPR. */
7249
7250 tree
7251 c_start_case (tree exp)
7252 {
7253 tree orig_type = error_mark_node;
7254 struct c_switch *cs;
7255
7256 if (exp != error_mark_node)
7257 {
7258 orig_type = TREE_TYPE (exp);
7259
7260 if (!INTEGRAL_TYPE_P (orig_type))
7261 {
7262 if (orig_type != error_mark_node)
7263 {
7264 error ("switch quantity not an integer");
7265 orig_type = error_mark_node;
7266 }
7267 exp = integer_zero_node;
7268 }
7269 else
7270 {
7271 tree type = TYPE_MAIN_VARIANT (orig_type);
7272
7273 if (!in_system_header
7274 && (type == long_integer_type_node
7275 || type == long_unsigned_type_node))
7276 warning (OPT_Wtraditional, "%<long%> switch expression not "
7277 "converted to %<int%> in ISO C");
7278
7279 exp = default_conversion (exp);
7280
7281 if (warn_sequence_point)
7282 verify_sequence_points (exp);
7283 }
7284 }
7285
7286 /* Add this new SWITCH_EXPR to the stack. */
7287 cs = XNEW (struct c_switch);
7288 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7289 cs->orig_type = orig_type;
7290 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7291 cs->blocked_stmt_expr = 0;
7292 cs->blocked_vm = 0;
7293 cs->next = c_switch_stack;
7294 c_switch_stack = cs;
7295
7296 return add_stmt (cs->switch_expr);
7297 }
7298
7299 /* Process a case label. */
7300
7301 tree
7302 do_case (tree low_value, tree high_value)
7303 {
7304 tree label = NULL_TREE;
7305
7306 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7307 && !c_switch_stack->blocked_vm)
7308 {
7309 label = c_add_case_label (c_switch_stack->cases,
7310 SWITCH_COND (c_switch_stack->switch_expr),
7311 c_switch_stack->orig_type,
7312 low_value, high_value);
7313 if (label == error_mark_node)
7314 label = NULL_TREE;
7315 }
7316 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7317 {
7318 if (low_value)
7319 error ("case label in statement expression not containing "
7320 "enclosing switch statement");
7321 else
7322 error ("%<default%> label in statement expression not containing "
7323 "enclosing switch statement");
7324 }
7325 else if (c_switch_stack && c_switch_stack->blocked_vm)
7326 {
7327 if (low_value)
7328 error ("case label in scope of identifier with variably modified "
7329 "type not containing enclosing switch statement");
7330 else
7331 error ("%<default%> label in scope of identifier with variably "
7332 "modified type not containing enclosing switch statement");
7333 }
7334 else if (low_value)
7335 error ("case label not within a switch statement");
7336 else
7337 error ("%<default%> label not within a switch statement");
7338
7339 return label;
7340 }
7341
7342 /* Finish the switch statement. */
7343
7344 void
7345 c_finish_case (tree body)
7346 {
7347 struct c_switch *cs = c_switch_stack;
7348 location_t switch_location;
7349
7350 SWITCH_BODY (cs->switch_expr) = body;
7351
7352 /* We must not be within a statement expression nested in the switch
7353 at this point; we might, however, be within the scope of an
7354 identifier with variably modified type nested in the switch. */
7355 gcc_assert (!cs->blocked_stmt_expr);
7356
7357 /* Emit warnings as needed. */
7358 if (EXPR_HAS_LOCATION (cs->switch_expr))
7359 switch_location = EXPR_LOCATION (cs->switch_expr);
7360 else
7361 switch_location = input_location;
7362 c_do_switch_warnings (cs->cases, switch_location,
7363 TREE_TYPE (cs->switch_expr),
7364 SWITCH_COND (cs->switch_expr));
7365
7366 /* Pop the stack. */
7367 c_switch_stack = cs->next;
7368 splay_tree_delete (cs->cases);
7369 XDELETE (cs);
7370 }
7371 \f
7372 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7373 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7374 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7375 statement, and was not surrounded with parenthesis. */
7376
7377 void
7378 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7379 tree else_block, bool nested_if)
7380 {
7381 tree stmt;
7382
7383 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7384 if (warn_parentheses && nested_if && else_block == NULL)
7385 {
7386 tree inner_if = then_block;
7387
7388 /* We know from the grammar productions that there is an IF nested
7389 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7390 it might not be exactly THEN_BLOCK, but should be the last
7391 non-container statement within. */
7392 while (1)
7393 switch (TREE_CODE (inner_if))
7394 {
7395 case COND_EXPR:
7396 goto found;
7397 case BIND_EXPR:
7398 inner_if = BIND_EXPR_BODY (inner_if);
7399 break;
7400 case STATEMENT_LIST:
7401 inner_if = expr_last (then_block);
7402 break;
7403 case TRY_FINALLY_EXPR:
7404 case TRY_CATCH_EXPR:
7405 inner_if = TREE_OPERAND (inner_if, 0);
7406 break;
7407 default:
7408 gcc_unreachable ();
7409 }
7410 found:
7411
7412 if (COND_EXPR_ELSE (inner_if))
7413 warning (OPT_Wparentheses,
7414 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7415 &if_locus);
7416 }
7417
7418 empty_if_body_warning (then_block, else_block);
7419
7420 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7421 SET_EXPR_LOCATION (stmt, if_locus);
7422 add_stmt (stmt);
7423 }
7424
7425 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7426 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7427 is false for DO loops. INCR is the FOR increment expression. BODY is
7428 the statement controlled by the loop. BLAB is the break label. CLAB is
7429 the continue label. Everything is allowed to be NULL. */
7430
7431 void
7432 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7433 tree blab, tree clab, bool cond_is_first)
7434 {
7435 tree entry = NULL, exit = NULL, t;
7436
7437 /* If the condition is zero don't generate a loop construct. */
7438 if (cond && integer_zerop (cond))
7439 {
7440 if (cond_is_first)
7441 {
7442 t = build_and_jump (&blab);
7443 SET_EXPR_LOCATION (t, start_locus);
7444 add_stmt (t);
7445 }
7446 }
7447 else
7448 {
7449 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7450
7451 /* If we have an exit condition, then we build an IF with gotos either
7452 out of the loop, or to the top of it. If there's no exit condition,
7453 then we just build a jump back to the top. */
7454 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7455
7456 if (cond && !integer_nonzerop (cond))
7457 {
7458 /* Canonicalize the loop condition to the end. This means
7459 generating a branch to the loop condition. Reuse the
7460 continue label, if possible. */
7461 if (cond_is_first)
7462 {
7463 if (incr || !clab)
7464 {
7465 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7466 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7467 }
7468 else
7469 t = build1 (GOTO_EXPR, void_type_node, clab);
7470 SET_EXPR_LOCATION (t, start_locus);
7471 add_stmt (t);
7472 }
7473
7474 t = build_and_jump (&blab);
7475 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7476 if (cond_is_first)
7477 SET_EXPR_LOCATION (exit, start_locus);
7478 else
7479 SET_EXPR_LOCATION (exit, input_location);
7480 }
7481
7482 add_stmt (top);
7483 }
7484
7485 if (body)
7486 add_stmt (body);
7487 if (clab)
7488 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7489 if (incr)
7490 add_stmt (incr);
7491 if (entry)
7492 add_stmt (entry);
7493 if (exit)
7494 add_stmt (exit);
7495 if (blab)
7496 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7497 }
7498
7499 tree
7500 c_finish_bc_stmt (tree *label_p, bool is_break)
7501 {
7502 bool skip;
7503 tree label = *label_p;
7504
7505 /* In switch statements break is sometimes stylistically used after
7506 a return statement. This can lead to spurious warnings about
7507 control reaching the end of a non-void function when it is
7508 inlined. Note that we are calling block_may_fallthru with
7509 language specific tree nodes; this works because
7510 block_may_fallthru returns true when given something it does not
7511 understand. */
7512 skip = !block_may_fallthru (cur_stmt_list);
7513
7514 if (!label)
7515 {
7516 if (!skip)
7517 *label_p = label = create_artificial_label ();
7518 }
7519 else if (TREE_CODE (label) == LABEL_DECL)
7520 ;
7521 else switch (TREE_INT_CST_LOW (label))
7522 {
7523 case 0:
7524 if (is_break)
7525 error ("break statement not within loop or switch");
7526 else
7527 error ("continue statement not within a loop");
7528 return NULL_TREE;
7529
7530 case 1:
7531 gcc_assert (is_break);
7532 error ("break statement used with OpenMP for loop");
7533 return NULL_TREE;
7534
7535 default:
7536 gcc_unreachable ();
7537 }
7538
7539 if (skip)
7540 return NULL_TREE;
7541
7542 if (!is_break)
7543 add_stmt (build_predict_expr (PRED_CONTINUE, NOT_TAKEN));
7544
7545 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7546 }
7547
7548 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7549
7550 static void
7551 emit_side_effect_warnings (tree expr)
7552 {
7553 if (expr == error_mark_node)
7554 ;
7555 else if (!TREE_SIDE_EFFECTS (expr))
7556 {
7557 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7558 warning (OPT_Wunused_value, "%Hstatement with no effect",
7559 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7560 }
7561 else
7562 warn_if_unused_value (expr, input_location);
7563 }
7564
7565 /* Process an expression as if it were a complete statement. Emit
7566 diagnostics, but do not call ADD_STMT. */
7567
7568 tree
7569 c_process_expr_stmt (tree expr)
7570 {
7571 if (!expr)
7572 return NULL_TREE;
7573
7574 if (warn_sequence_point)
7575 verify_sequence_points (expr);
7576
7577 if (TREE_TYPE (expr) != error_mark_node
7578 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7579 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7580 error ("expression statement has incomplete type");
7581
7582 /* If we're not processing a statement expression, warn about unused values.
7583 Warnings for statement expressions will be emitted later, once we figure
7584 out which is the result. */
7585 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7586 && warn_unused_value)
7587 emit_side_effect_warnings (expr);
7588
7589 /* If the expression is not of a type to which we cannot assign a line
7590 number, wrap the thing in a no-op NOP_EXPR. */
7591 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7592 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7593
7594 if (CAN_HAVE_LOCATION_P (expr))
7595 SET_EXPR_LOCATION (expr, input_location);
7596
7597 return expr;
7598 }
7599
7600 /* Emit an expression as a statement. */
7601
7602 tree
7603 c_finish_expr_stmt (tree expr)
7604 {
7605 if (expr)
7606 return add_stmt (c_process_expr_stmt (expr));
7607 else
7608 return NULL;
7609 }
7610
7611 /* Do the opposite and emit a statement as an expression. To begin,
7612 create a new binding level and return it. */
7613
7614 tree
7615 c_begin_stmt_expr (void)
7616 {
7617 tree ret;
7618 struct c_label_context_se *nstack;
7619 struct c_label_list *glist;
7620
7621 /* We must force a BLOCK for this level so that, if it is not expanded
7622 later, there is a way to turn off the entire subtree of blocks that
7623 are contained in it. */
7624 keep_next_level ();
7625 ret = c_begin_compound_stmt (true);
7626 if (c_switch_stack)
7627 {
7628 c_switch_stack->blocked_stmt_expr++;
7629 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7630 }
7631 for (glist = label_context_stack_se->labels_used;
7632 glist != NULL;
7633 glist = glist->next)
7634 {
7635 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7636 }
7637 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7638 nstack->labels_def = NULL;
7639 nstack->labels_used = NULL;
7640 nstack->next = label_context_stack_se;
7641 label_context_stack_se = nstack;
7642
7643 /* Mark the current statement list as belonging to a statement list. */
7644 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7645
7646 return ret;
7647 }
7648
7649 tree
7650 c_finish_stmt_expr (tree body)
7651 {
7652 tree last, type, tmp, val;
7653 tree *last_p;
7654 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7655
7656 body = c_end_compound_stmt (body, true);
7657 if (c_switch_stack)
7658 {
7659 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7660 c_switch_stack->blocked_stmt_expr--;
7661 }
7662 /* It is no longer possible to jump to labels defined within this
7663 statement expression. */
7664 for (dlist = label_context_stack_se->labels_def;
7665 dlist != NULL;
7666 dlist = dlist->next)
7667 {
7668 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7669 }
7670 /* It is again possible to define labels with a goto just outside
7671 this statement expression. */
7672 for (glist = label_context_stack_se->next->labels_used;
7673 glist != NULL;
7674 glist = glist->next)
7675 {
7676 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7677 glist_prev = glist;
7678 }
7679 if (glist_prev != NULL)
7680 glist_prev->next = label_context_stack_se->labels_used;
7681 else
7682 label_context_stack_se->next->labels_used
7683 = label_context_stack_se->labels_used;
7684 label_context_stack_se = label_context_stack_se->next;
7685
7686 /* Locate the last statement in BODY. See c_end_compound_stmt
7687 about always returning a BIND_EXPR. */
7688 last_p = &BIND_EXPR_BODY (body);
7689 last = BIND_EXPR_BODY (body);
7690
7691 continue_searching:
7692 if (TREE_CODE (last) == STATEMENT_LIST)
7693 {
7694 tree_stmt_iterator i;
7695
7696 /* This can happen with degenerate cases like ({ }). No value. */
7697 if (!TREE_SIDE_EFFECTS (last))
7698 return body;
7699
7700 /* If we're supposed to generate side effects warnings, process
7701 all of the statements except the last. */
7702 if (warn_unused_value)
7703 {
7704 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7705 emit_side_effect_warnings (tsi_stmt (i));
7706 }
7707 else
7708 i = tsi_last (last);
7709 last_p = tsi_stmt_ptr (i);
7710 last = *last_p;
7711 }
7712
7713 /* If the end of the list is exception related, then the list was split
7714 by a call to push_cleanup. Continue searching. */
7715 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7716 || TREE_CODE (last) == TRY_CATCH_EXPR)
7717 {
7718 last_p = &TREE_OPERAND (last, 0);
7719 last = *last_p;
7720 goto continue_searching;
7721 }
7722
7723 /* In the case that the BIND_EXPR is not necessary, return the
7724 expression out from inside it. */
7725 if (last == error_mark_node
7726 || (last == BIND_EXPR_BODY (body)
7727 && BIND_EXPR_VARS (body) == NULL))
7728 {
7729 /* Do not warn if the return value of a statement expression is
7730 unused. */
7731 if (CAN_HAVE_LOCATION_P (last))
7732 TREE_NO_WARNING (last) = 1;
7733 return last;
7734 }
7735
7736 /* Extract the type of said expression. */
7737 type = TREE_TYPE (last);
7738
7739 /* If we're not returning a value at all, then the BIND_EXPR that
7740 we already have is a fine expression to return. */
7741 if (!type || VOID_TYPE_P (type))
7742 return body;
7743
7744 /* Now that we've located the expression containing the value, it seems
7745 silly to make voidify_wrapper_expr repeat the process. Create a
7746 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7747 tmp = create_tmp_var_raw (type, NULL);
7748
7749 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7750 tree_expr_nonnegative_p giving up immediately. */
7751 val = last;
7752 if (TREE_CODE (val) == NOP_EXPR
7753 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7754 val = TREE_OPERAND (val, 0);
7755
7756 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7757 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7758
7759 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7760 }
7761
7762 /* Begin the scope of an identifier of variably modified type, scope
7763 number SCOPE. Jumping from outside this scope to inside it is not
7764 permitted. */
7765
7766 void
7767 c_begin_vm_scope (unsigned int scope)
7768 {
7769 struct c_label_context_vm *nstack;
7770 struct c_label_list *glist;
7771
7772 gcc_assert (scope > 0);
7773
7774 /* At file_scope, we don't have to do any processing. */
7775 if (label_context_stack_vm == NULL)
7776 return;
7777
7778 if (c_switch_stack && !c_switch_stack->blocked_vm)
7779 c_switch_stack->blocked_vm = scope;
7780 for (glist = label_context_stack_vm->labels_used;
7781 glist != NULL;
7782 glist = glist->next)
7783 {
7784 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7785 }
7786 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7787 nstack->labels_def = NULL;
7788 nstack->labels_used = NULL;
7789 nstack->scope = scope;
7790 nstack->next = label_context_stack_vm;
7791 label_context_stack_vm = nstack;
7792 }
7793
7794 /* End a scope which may contain identifiers of variably modified
7795 type, scope number SCOPE. */
7796
7797 void
7798 c_end_vm_scope (unsigned int scope)
7799 {
7800 if (label_context_stack_vm == NULL)
7801 return;
7802 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7803 c_switch_stack->blocked_vm = 0;
7804 /* We may have a number of nested scopes of identifiers with
7805 variably modified type, all at this depth. Pop each in turn. */
7806 while (label_context_stack_vm->scope == scope)
7807 {
7808 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7809
7810 /* It is no longer possible to jump to labels defined within this
7811 scope. */
7812 for (dlist = label_context_stack_vm->labels_def;
7813 dlist != NULL;
7814 dlist = dlist->next)
7815 {
7816 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7817 }
7818 /* It is again possible to define labels with a goto just outside
7819 this scope. */
7820 for (glist = label_context_stack_vm->next->labels_used;
7821 glist != NULL;
7822 glist = glist->next)
7823 {
7824 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7825 glist_prev = glist;
7826 }
7827 if (glist_prev != NULL)
7828 glist_prev->next = label_context_stack_vm->labels_used;
7829 else
7830 label_context_stack_vm->next->labels_used
7831 = label_context_stack_vm->labels_used;
7832 label_context_stack_vm = label_context_stack_vm->next;
7833 }
7834 }
7835 \f
7836 /* Begin and end compound statements. This is as simple as pushing
7837 and popping new statement lists from the tree. */
7838
7839 tree
7840 c_begin_compound_stmt (bool do_scope)
7841 {
7842 tree stmt = push_stmt_list ();
7843 if (do_scope)
7844 push_scope ();
7845 return stmt;
7846 }
7847
7848 tree
7849 c_end_compound_stmt (tree stmt, bool do_scope)
7850 {
7851 tree block = NULL;
7852
7853 if (do_scope)
7854 {
7855 if (c_dialect_objc ())
7856 objc_clear_super_receiver ();
7857 block = pop_scope ();
7858 }
7859
7860 stmt = pop_stmt_list (stmt);
7861 stmt = c_build_bind_expr (block, stmt);
7862
7863 /* If this compound statement is nested immediately inside a statement
7864 expression, then force a BIND_EXPR to be created. Otherwise we'll
7865 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7866 STATEMENT_LISTs merge, and thus we can lose track of what statement
7867 was really last. */
7868 if (cur_stmt_list
7869 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7870 && TREE_CODE (stmt) != BIND_EXPR)
7871 {
7872 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7873 TREE_SIDE_EFFECTS (stmt) = 1;
7874 }
7875
7876 return stmt;
7877 }
7878
7879 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7880 when the current scope is exited. EH_ONLY is true when this is not
7881 meant to apply to normal control flow transfer. */
7882
7883 void
7884 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7885 {
7886 enum tree_code code;
7887 tree stmt, list;
7888 bool stmt_expr;
7889
7890 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7891 stmt = build_stmt (code, NULL, cleanup);
7892 add_stmt (stmt);
7893 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7894 list = push_stmt_list ();
7895 TREE_OPERAND (stmt, 0) = list;
7896 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7897 }
7898 \f
7899 /* Build a binary-operation expression without default conversions.
7900 CODE is the kind of expression to build.
7901 This function differs from `build' in several ways:
7902 the data type of the result is computed and recorded in it,
7903 warnings are generated if arg data types are invalid,
7904 special handling for addition and subtraction of pointers is known,
7905 and some optimization is done (operations on narrow ints
7906 are done in the narrower type when that gives the same result).
7907 Constant folding is also done before the result is returned.
7908
7909 Note that the operands will never have enumeral types, or function
7910 or array types, because either they will have the default conversions
7911 performed or they have both just been converted to some other type in which
7912 the arithmetic is to be done. */
7913
7914 tree
7915 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7916 int convert_p)
7917 {
7918 tree type0, type1;
7919 enum tree_code code0, code1;
7920 tree op0, op1;
7921 const char *invalid_op_diag;
7922
7923 /* Expression code to give to the expression when it is built.
7924 Normally this is CODE, which is what the caller asked for,
7925 but in some special cases we change it. */
7926 enum tree_code resultcode = code;
7927
7928 /* Data type in which the computation is to be performed.
7929 In the simplest cases this is the common type of the arguments. */
7930 tree result_type = NULL;
7931
7932 /* Nonzero means operands have already been type-converted
7933 in whatever way is necessary.
7934 Zero means they need to be converted to RESULT_TYPE. */
7935 int converted = 0;
7936
7937 /* Nonzero means create the expression with this type, rather than
7938 RESULT_TYPE. */
7939 tree build_type = 0;
7940
7941 /* Nonzero means after finally constructing the expression
7942 convert it to this type. */
7943 tree final_type = 0;
7944
7945 /* Nonzero if this is an operation like MIN or MAX which can
7946 safely be computed in short if both args are promoted shorts.
7947 Also implies COMMON.
7948 -1 indicates a bitwise operation; this makes a difference
7949 in the exact conditions for when it is safe to do the operation
7950 in a narrower mode. */
7951 int shorten = 0;
7952
7953 /* Nonzero if this is a comparison operation;
7954 if both args are promoted shorts, compare the original shorts.
7955 Also implies COMMON. */
7956 int short_compare = 0;
7957
7958 /* Nonzero if this is a right-shift operation, which can be computed on the
7959 original short and then promoted if the operand is a promoted short. */
7960 int short_shift = 0;
7961
7962 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7963 int common = 0;
7964
7965 /* True means types are compatible as far as ObjC is concerned. */
7966 bool objc_ok;
7967
7968 if (convert_p)
7969 {
7970 op0 = default_conversion (orig_op0);
7971 op1 = default_conversion (orig_op1);
7972 }
7973 else
7974 {
7975 op0 = orig_op0;
7976 op1 = orig_op1;
7977 }
7978
7979 type0 = TREE_TYPE (op0);
7980 type1 = TREE_TYPE (op1);
7981
7982 /* The expression codes of the data types of the arguments tell us
7983 whether the arguments are integers, floating, pointers, etc. */
7984 code0 = TREE_CODE (type0);
7985 code1 = TREE_CODE (type1);
7986
7987 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7988 STRIP_TYPE_NOPS (op0);
7989 STRIP_TYPE_NOPS (op1);
7990
7991 /* If an error was already reported for one of the arguments,
7992 avoid reporting another error. */
7993
7994 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7995 return error_mark_node;
7996
7997 if ((invalid_op_diag
7998 = targetm.invalid_binary_op (code, type0, type1)))
7999 {
8000 error (invalid_op_diag);
8001 return error_mark_node;
8002 }
8003
8004 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
8005
8006 switch (code)
8007 {
8008 case PLUS_EXPR:
8009 /* Handle the pointer + int case. */
8010 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8011 return pointer_int_sum (PLUS_EXPR, op0, op1);
8012 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
8013 return pointer_int_sum (PLUS_EXPR, op1, op0);
8014 else
8015 common = 1;
8016 break;
8017
8018 case MINUS_EXPR:
8019 /* Subtraction of two similar pointers.
8020 We must subtract them as integers, then divide by object size. */
8021 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
8022 && comp_target_types (type0, type1))
8023 return pointer_diff (op0, op1);
8024 /* Handle pointer minus int. Just like pointer plus int. */
8025 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8026 return pointer_int_sum (MINUS_EXPR, op0, op1);
8027 else
8028 common = 1;
8029 break;
8030
8031 case MULT_EXPR:
8032 common = 1;
8033 break;
8034
8035 case TRUNC_DIV_EXPR:
8036 case CEIL_DIV_EXPR:
8037 case FLOOR_DIV_EXPR:
8038 case ROUND_DIV_EXPR:
8039 case EXACT_DIV_EXPR:
8040 warn_for_div_by_zero (op1);
8041
8042 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8043 || code0 == FIXED_POINT_TYPE
8044 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
8045 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8046 || code1 == FIXED_POINT_TYPE
8047 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
8048 {
8049 enum tree_code tcode0 = code0, tcode1 = code1;
8050
8051 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
8052 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
8053 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
8054 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
8055
8056 if (!((tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE)
8057 || (tcode0 == FIXED_POINT_TYPE && tcode1 == FIXED_POINT_TYPE)))
8058 resultcode = RDIV_EXPR;
8059 else
8060 /* Although it would be tempting to shorten always here, that
8061 loses on some targets, since the modulo instruction is
8062 undefined if the quotient can't be represented in the
8063 computation mode. We shorten only if unsigned or if
8064 dividing by something we know != -1. */
8065 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
8066 || (TREE_CODE (op1) == INTEGER_CST
8067 && !integer_all_onesp (op1)));
8068 common = 1;
8069 }
8070 break;
8071
8072 case BIT_AND_EXPR:
8073 case BIT_IOR_EXPR:
8074 case BIT_XOR_EXPR:
8075 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8076 shorten = -1;
8077 /* Allow vector types which are not floating point types. */
8078 else if (code0 == VECTOR_TYPE
8079 && code1 == VECTOR_TYPE
8080 && !VECTOR_FLOAT_TYPE_P (type0)
8081 && !VECTOR_FLOAT_TYPE_P (type1))
8082 common = 1;
8083 break;
8084
8085 case TRUNC_MOD_EXPR:
8086 case FLOOR_MOD_EXPR:
8087 warn_for_div_by_zero (op1);
8088
8089 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8090 {
8091 /* Although it would be tempting to shorten always here, that loses
8092 on some targets, since the modulo instruction is undefined if the
8093 quotient can't be represented in the computation mode. We shorten
8094 only if unsigned or if dividing by something we know != -1. */
8095 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
8096 || (TREE_CODE (op1) == INTEGER_CST
8097 && !integer_all_onesp (op1)));
8098 common = 1;
8099 }
8100 break;
8101
8102 case TRUTH_ANDIF_EXPR:
8103 case TRUTH_ORIF_EXPR:
8104 case TRUTH_AND_EXPR:
8105 case TRUTH_OR_EXPR:
8106 case TRUTH_XOR_EXPR:
8107 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
8108 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8109 || code0 == FIXED_POINT_TYPE)
8110 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
8111 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8112 || code1 == FIXED_POINT_TYPE))
8113 {
8114 /* Result of these operations is always an int,
8115 but that does not mean the operands should be
8116 converted to ints! */
8117 result_type = integer_type_node;
8118 op0 = c_common_truthvalue_conversion (op0);
8119 op1 = c_common_truthvalue_conversion (op1);
8120 converted = 1;
8121 }
8122 break;
8123
8124 /* Shift operations: result has same type as first operand;
8125 always convert second operand to int.
8126 Also set SHORT_SHIFT if shifting rightward. */
8127
8128 case RSHIFT_EXPR:
8129 if ((code0 == INTEGER_TYPE || code0 == FIXED_POINT_TYPE)
8130 && code1 == INTEGER_TYPE)
8131 {
8132 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8133 {
8134 if (tree_int_cst_sgn (op1) < 0)
8135 warning (0, "right shift count is negative");
8136 else
8137 {
8138 if (!integer_zerop (op1))
8139 short_shift = 1;
8140
8141 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8142 warning (0, "right shift count >= width of type");
8143 }
8144 }
8145
8146 /* Use the type of the value to be shifted. */
8147 result_type = type0;
8148 /* Convert the shift-count to an integer, regardless of size
8149 of value being shifted. */
8150 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8151 op1 = convert (integer_type_node, op1);
8152 /* Avoid converting op1 to result_type later. */
8153 converted = 1;
8154 }
8155 break;
8156
8157 case LSHIFT_EXPR:
8158 if ((code0 == INTEGER_TYPE || code0 == FIXED_POINT_TYPE)
8159 && code1 == INTEGER_TYPE)
8160 {
8161 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8162 {
8163 if (tree_int_cst_sgn (op1) < 0)
8164 warning (0, "left shift count is negative");
8165
8166 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8167 warning (0, "left shift count >= width of type");
8168 }
8169
8170 /* Use the type of the value to be shifted. */
8171 result_type = type0;
8172 /* Convert the shift-count to an integer, regardless of size
8173 of value being shifted. */
8174 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8175 op1 = convert (integer_type_node, op1);
8176 /* Avoid converting op1 to result_type later. */
8177 converted = 1;
8178 }
8179 break;
8180
8181 case EQ_EXPR:
8182 case NE_EXPR:
8183 if (FLOAT_TYPE_P (type0) || FLOAT_TYPE_P (type1))
8184 warning (OPT_Wfloat_equal,
8185 "comparing floating point with == or != is unsafe");
8186 /* Result of comparison is always int,
8187 but don't convert the args to int! */
8188 build_type = integer_type_node;
8189 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8190 || code0 == FIXED_POINT_TYPE || code0 == COMPLEX_TYPE)
8191 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8192 || code1 == FIXED_POINT_TYPE || code1 == COMPLEX_TYPE))
8193 short_compare = 1;
8194 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8195 {
8196 tree tt0 = TREE_TYPE (type0);
8197 tree tt1 = TREE_TYPE (type1);
8198 /* Anything compares with void *. void * compares with anything.
8199 Otherwise, the targets must be compatible
8200 and both must be object or both incomplete. */
8201 if (comp_target_types (type0, type1))
8202 result_type = common_pointer_type (type0, type1);
8203 else if (VOID_TYPE_P (tt0))
8204 {
8205 /* op0 != orig_op0 detects the case of something
8206 whose value is 0 but which isn't a valid null ptr const. */
8207 if (pedantic && !null_pointer_constant_p (orig_op0)
8208 && TREE_CODE (tt1) == FUNCTION_TYPE)
8209 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
8210 "comparison of %<void *%> with function pointer");
8211 }
8212 else if (VOID_TYPE_P (tt1))
8213 {
8214 if (pedantic && !null_pointer_constant_p (orig_op1)
8215 && TREE_CODE (tt0) == FUNCTION_TYPE)
8216 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
8217 "comparison of %<void *%> with function pointer");
8218 }
8219 else
8220 /* Avoid warning about the volatile ObjC EH puts on decls. */
8221 if (!objc_ok)
8222 pedwarn (input_location, 0,
8223 "comparison of distinct pointer types lacks a cast");
8224
8225 if (result_type == NULL_TREE)
8226 result_type = ptr_type_node;
8227 }
8228 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8229 {
8230 if (TREE_CODE (op0) == ADDR_EXPR
8231 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
8232 warning (OPT_Waddress, "the address of %qD will never be NULL",
8233 TREE_OPERAND (op0, 0));
8234 result_type = type0;
8235 }
8236 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8237 {
8238 if (TREE_CODE (op1) == ADDR_EXPR
8239 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
8240 warning (OPT_Waddress, "the address of %qD will never be NULL",
8241 TREE_OPERAND (op1, 0));
8242 result_type = type1;
8243 }
8244 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8245 {
8246 result_type = type0;
8247 pedwarn (input_location, 0, "comparison between pointer and integer");
8248 }
8249 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8250 {
8251 result_type = type1;
8252 pedwarn (input_location, 0, "comparison between pointer and integer");
8253 }
8254 break;
8255
8256 case LE_EXPR:
8257 case GE_EXPR:
8258 case LT_EXPR:
8259 case GT_EXPR:
8260 build_type = integer_type_node;
8261 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8262 || code0 == FIXED_POINT_TYPE)
8263 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8264 || code1 == FIXED_POINT_TYPE))
8265 short_compare = 1;
8266 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8267 {
8268 if (comp_target_types (type0, type1))
8269 {
8270 result_type = common_pointer_type (type0, type1);
8271 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8272 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8273 pedwarn (input_location, 0,
8274 "comparison of complete and incomplete pointers");
8275 else if (TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8276 pedwarn (input_location, OPT_pedantic, "ISO C forbids "
8277 "ordered comparisons of pointers to functions");
8278 }
8279 else
8280 {
8281 result_type = ptr_type_node;
8282 pedwarn (input_location, 0,
8283 "comparison of distinct pointer types lacks a cast");
8284 }
8285 }
8286 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8287 {
8288 result_type = type0;
8289 if (pedantic)
8290 pedwarn (input_location, OPT_pedantic,
8291 "ordered comparison of pointer with integer zero");
8292 else if (extra_warnings)
8293 warning (OPT_Wextra,
8294 "ordered comparison of pointer with integer zero");
8295 }
8296 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8297 {
8298 result_type = type1;
8299 pedwarn (input_location, OPT_pedantic,
8300 "ordered comparison of pointer with integer zero");
8301 }
8302 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8303 {
8304 result_type = type0;
8305 pedwarn (input_location, 0, "comparison between pointer and integer");
8306 }
8307 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8308 {
8309 result_type = type1;
8310 pedwarn (input_location, 0, "comparison between pointer and integer");
8311 }
8312 break;
8313
8314 default:
8315 gcc_unreachable ();
8316 }
8317
8318 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8319 return error_mark_node;
8320
8321 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8322 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8323 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8324 TREE_TYPE (type1))))
8325 {
8326 binary_op_error (code, type0, type1);
8327 return error_mark_node;
8328 }
8329
8330 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8331 || code0 == FIXED_POINT_TYPE || code0 == VECTOR_TYPE)
8332 &&
8333 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8334 || code1 == FIXED_POINT_TYPE || code1 == VECTOR_TYPE))
8335 {
8336 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8337
8338 if (shorten || common || short_compare)
8339 {
8340 result_type = c_common_type (type0, type1);
8341 if (result_type == error_mark_node)
8342 return error_mark_node;
8343 }
8344
8345 /* For certain operations (which identify themselves by shorten != 0)
8346 if both args were extended from the same smaller type,
8347 do the arithmetic in that type and then extend.
8348
8349 shorten !=0 and !=1 indicates a bitwise operation.
8350 For them, this optimization is safe only if
8351 both args are zero-extended or both are sign-extended.
8352 Otherwise, we might change the result.
8353 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8354 but calculated in (unsigned short) it would be (unsigned short)-1. */
8355
8356 if (shorten && none_complex)
8357 {
8358 final_type = result_type;
8359 result_type = shorten_binary_op (result_type, op0, op1,
8360 shorten == -1);
8361 }
8362
8363 /* Shifts can be shortened if shifting right. */
8364
8365 if (short_shift)
8366 {
8367 int unsigned_arg;
8368 tree arg0 = get_narrower (op0, &unsigned_arg);
8369
8370 final_type = result_type;
8371
8372 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8373 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8374
8375 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8376 /* We can shorten only if the shift count is less than the
8377 number of bits in the smaller type size. */
8378 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8379 /* We cannot drop an unsigned shift after sign-extension. */
8380 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8381 {
8382 /* Do an unsigned shift if the operand was zero-extended. */
8383 result_type
8384 = c_common_signed_or_unsigned_type (unsigned_arg,
8385 TREE_TYPE (arg0));
8386 /* Convert value-to-be-shifted to that type. */
8387 if (TREE_TYPE (op0) != result_type)
8388 op0 = convert (result_type, op0);
8389 converted = 1;
8390 }
8391 }
8392
8393 /* Comparison operations are shortened too but differently.
8394 They identify themselves by setting short_compare = 1. */
8395
8396 if (short_compare)
8397 {
8398 /* Don't write &op0, etc., because that would prevent op0
8399 from being kept in a register.
8400 Instead, make copies of the our local variables and
8401 pass the copies by reference, then copy them back afterward. */
8402 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8403 enum tree_code xresultcode = resultcode;
8404 tree val
8405 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8406
8407 if (val != 0)
8408 return val;
8409
8410 op0 = xop0, op1 = xop1;
8411 converted = 1;
8412 resultcode = xresultcode;
8413
8414 if (warn_sign_compare && !skip_evaluation)
8415 {
8416 warn_for_sign_compare (orig_op0, orig_op1, op0, op1,
8417 result_type, resultcode);
8418 }
8419 }
8420 }
8421
8422 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8423 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8424 Then the expression will be built.
8425 It will be given type FINAL_TYPE if that is nonzero;
8426 otherwise, it will be given type RESULT_TYPE. */
8427
8428 if (!result_type)
8429 {
8430 binary_op_error (code, TREE_TYPE (op0), TREE_TYPE (op1));
8431 return error_mark_node;
8432 }
8433
8434 if (!converted)
8435 {
8436 if (TREE_TYPE (op0) != result_type)
8437 op0 = convert_and_check (result_type, op0);
8438 if (TREE_TYPE (op1) != result_type)
8439 op1 = convert_and_check (result_type, op1);
8440
8441 /* This can happen if one operand has a vector type, and the other
8442 has a different type. */
8443 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8444 return error_mark_node;
8445 }
8446
8447 if (build_type == NULL_TREE)
8448 build_type = result_type;
8449
8450 {
8451 /* Treat expressions in initializers specially as they can't trap. */
8452 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8453 build_type,
8454 op0, op1)
8455 : fold_build2 (resultcode, build_type,
8456 op0, op1);
8457
8458 if (final_type != 0)
8459 result = convert (final_type, result);
8460 return result;
8461 }
8462 }
8463
8464
8465 /* Convert EXPR to be a truth-value, validating its type for this
8466 purpose. */
8467
8468 tree
8469 c_objc_common_truthvalue_conversion (tree expr)
8470 {
8471 switch (TREE_CODE (TREE_TYPE (expr)))
8472 {
8473 case ARRAY_TYPE:
8474 error ("used array that cannot be converted to pointer where scalar is required");
8475 return error_mark_node;
8476
8477 case RECORD_TYPE:
8478 error ("used struct type value where scalar is required");
8479 return error_mark_node;
8480
8481 case UNION_TYPE:
8482 error ("used union type value where scalar is required");
8483 return error_mark_node;
8484
8485 case FUNCTION_TYPE:
8486 gcc_unreachable ();
8487
8488 default:
8489 break;
8490 }
8491
8492 /* ??? Should we also give an error for void and vectors rather than
8493 leaving those to give errors later? */
8494 return c_common_truthvalue_conversion (expr);
8495 }
8496 \f
8497
8498 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8499 required. */
8500
8501 tree
8502 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED, bool *se)
8503 {
8504 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8505 {
8506 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8507 /* Executing a compound literal inside a function reinitializes
8508 it. */
8509 if (!TREE_STATIC (decl))
8510 *se = true;
8511 return decl;
8512 }
8513 else
8514 return expr;
8515 }
8516 \f
8517 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8518
8519 tree
8520 c_begin_omp_parallel (void)
8521 {
8522 tree block;
8523
8524 keep_next_level ();
8525 block = c_begin_compound_stmt (true);
8526
8527 return block;
8528 }
8529
8530 /* Generate OMP_PARALLEL, with CLAUSES and BLOCK as its compound statement. */
8531
8532 tree
8533 c_finish_omp_parallel (tree clauses, tree block)
8534 {
8535 tree stmt;
8536
8537 block = c_end_compound_stmt (block, true);
8538
8539 stmt = make_node (OMP_PARALLEL);
8540 TREE_TYPE (stmt) = void_type_node;
8541 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8542 OMP_PARALLEL_BODY (stmt) = block;
8543
8544 return add_stmt (stmt);
8545 }
8546
8547 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8548
8549 tree
8550 c_begin_omp_task (void)
8551 {
8552 tree block;
8553
8554 keep_next_level ();
8555 block = c_begin_compound_stmt (true);
8556
8557 return block;
8558 }
8559
8560 /* Generate OMP_TASK, with CLAUSES and BLOCK as its compound statement. */
8561
8562 tree
8563 c_finish_omp_task (tree clauses, tree block)
8564 {
8565 tree stmt;
8566
8567 block = c_end_compound_stmt (block, true);
8568
8569 stmt = make_node (OMP_TASK);
8570 TREE_TYPE (stmt) = void_type_node;
8571 OMP_TASK_CLAUSES (stmt) = clauses;
8572 OMP_TASK_BODY (stmt) = block;
8573
8574 return add_stmt (stmt);
8575 }
8576
8577 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8578 Remove any elements from the list that are invalid. */
8579
8580 tree
8581 c_finish_omp_clauses (tree clauses)
8582 {
8583 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8584 tree c, t, *pc = &clauses;
8585 const char *name;
8586
8587 bitmap_obstack_initialize (NULL);
8588 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8589 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8590 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8591
8592 for (pc = &clauses, c = clauses; c ; c = *pc)
8593 {
8594 bool remove = false;
8595 bool need_complete = false;
8596 bool need_implicitly_determined = false;
8597
8598 switch (OMP_CLAUSE_CODE (c))
8599 {
8600 case OMP_CLAUSE_SHARED:
8601 name = "shared";
8602 need_implicitly_determined = true;
8603 goto check_dup_generic;
8604
8605 case OMP_CLAUSE_PRIVATE:
8606 name = "private";
8607 need_complete = true;
8608 need_implicitly_determined = true;
8609 goto check_dup_generic;
8610
8611 case OMP_CLAUSE_REDUCTION:
8612 name = "reduction";
8613 need_implicitly_determined = true;
8614 t = OMP_CLAUSE_DECL (c);
8615 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8616 || POINTER_TYPE_P (TREE_TYPE (t)))
8617 {
8618 error ("%qE has invalid type for %<reduction%>", t);
8619 remove = true;
8620 }
8621 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8622 {
8623 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8624 const char *r_name = NULL;
8625
8626 switch (r_code)
8627 {
8628 case PLUS_EXPR:
8629 case MULT_EXPR:
8630 case MINUS_EXPR:
8631 break;
8632 case BIT_AND_EXPR:
8633 r_name = "&";
8634 break;
8635 case BIT_XOR_EXPR:
8636 r_name = "^";
8637 break;
8638 case BIT_IOR_EXPR:
8639 r_name = "|";
8640 break;
8641 case TRUTH_ANDIF_EXPR:
8642 r_name = "&&";
8643 break;
8644 case TRUTH_ORIF_EXPR:
8645 r_name = "||";
8646 break;
8647 default:
8648 gcc_unreachable ();
8649 }
8650 if (r_name)
8651 {
8652 error ("%qE has invalid type for %<reduction(%s)%>",
8653 t, r_name);
8654 remove = true;
8655 }
8656 }
8657 goto check_dup_generic;
8658
8659 case OMP_CLAUSE_COPYPRIVATE:
8660 name = "copyprivate";
8661 goto check_dup_generic;
8662
8663 case OMP_CLAUSE_COPYIN:
8664 name = "copyin";
8665 t = OMP_CLAUSE_DECL (c);
8666 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8667 {
8668 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8669 remove = true;
8670 }
8671 goto check_dup_generic;
8672
8673 check_dup_generic:
8674 t = OMP_CLAUSE_DECL (c);
8675 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8676 {
8677 error ("%qE is not a variable in clause %qs", t, name);
8678 remove = true;
8679 }
8680 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8681 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8682 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8683 {
8684 error ("%qE appears more than once in data clauses", t);
8685 remove = true;
8686 }
8687 else
8688 bitmap_set_bit (&generic_head, DECL_UID (t));
8689 break;
8690
8691 case OMP_CLAUSE_FIRSTPRIVATE:
8692 name = "firstprivate";
8693 t = OMP_CLAUSE_DECL (c);
8694 need_complete = true;
8695 need_implicitly_determined = true;
8696 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8697 {
8698 error ("%qE is not a variable in clause %<firstprivate%>", t);
8699 remove = true;
8700 }
8701 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8702 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8703 {
8704 error ("%qE appears more than once in data clauses", t);
8705 remove = true;
8706 }
8707 else
8708 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8709 break;
8710
8711 case OMP_CLAUSE_LASTPRIVATE:
8712 name = "lastprivate";
8713 t = OMP_CLAUSE_DECL (c);
8714 need_complete = true;
8715 need_implicitly_determined = true;
8716 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8717 {
8718 error ("%qE is not a variable in clause %<lastprivate%>", t);
8719 remove = true;
8720 }
8721 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8722 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8723 {
8724 error ("%qE appears more than once in data clauses", t);
8725 remove = true;
8726 }
8727 else
8728 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8729 break;
8730
8731 case OMP_CLAUSE_IF:
8732 case OMP_CLAUSE_NUM_THREADS:
8733 case OMP_CLAUSE_SCHEDULE:
8734 case OMP_CLAUSE_NOWAIT:
8735 case OMP_CLAUSE_ORDERED:
8736 case OMP_CLAUSE_DEFAULT:
8737 case OMP_CLAUSE_UNTIED:
8738 case OMP_CLAUSE_COLLAPSE:
8739 pc = &OMP_CLAUSE_CHAIN (c);
8740 continue;
8741
8742 default:
8743 gcc_unreachable ();
8744 }
8745
8746 if (!remove)
8747 {
8748 t = OMP_CLAUSE_DECL (c);
8749
8750 if (need_complete)
8751 {
8752 t = require_complete_type (t);
8753 if (t == error_mark_node)
8754 remove = true;
8755 }
8756
8757 if (need_implicitly_determined)
8758 {
8759 const char *share_name = NULL;
8760
8761 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8762 share_name = "threadprivate";
8763 else switch (c_omp_predetermined_sharing (t))
8764 {
8765 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8766 break;
8767 case OMP_CLAUSE_DEFAULT_SHARED:
8768 share_name = "shared";
8769 break;
8770 case OMP_CLAUSE_DEFAULT_PRIVATE:
8771 share_name = "private";
8772 break;
8773 default:
8774 gcc_unreachable ();
8775 }
8776 if (share_name)
8777 {
8778 error ("%qE is predetermined %qs for %qs",
8779 t, share_name, name);
8780 remove = true;
8781 }
8782 }
8783 }
8784
8785 if (remove)
8786 *pc = OMP_CLAUSE_CHAIN (c);
8787 else
8788 pc = &OMP_CLAUSE_CHAIN (c);
8789 }
8790
8791 bitmap_obstack_release (NULL);
8792 return clauses;
8793 }
8794
8795 /* Make a variant type in the proper way for C/C++, propagating qualifiers
8796 down to the element type of an array. */
8797
8798 tree
8799 c_build_qualified_type (tree type, int type_quals)
8800 {
8801 if (type == error_mark_node)
8802 return type;
8803
8804 if (TREE_CODE (type) == ARRAY_TYPE)
8805 {
8806 tree t;
8807 tree element_type = c_build_qualified_type (TREE_TYPE (type),
8808 type_quals);
8809
8810 /* See if we already have an identically qualified type. */
8811 for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
8812 {
8813 if (TYPE_QUALS (strip_array_types (t)) == type_quals
8814 && TYPE_NAME (t) == TYPE_NAME (type)
8815 && TYPE_CONTEXT (t) == TYPE_CONTEXT (type)
8816 && attribute_list_equal (TYPE_ATTRIBUTES (t),
8817 TYPE_ATTRIBUTES (type)))
8818 break;
8819 }
8820 if (!t)
8821 {
8822 tree domain = TYPE_DOMAIN (type);
8823
8824 t = build_variant_type_copy (type);
8825 TREE_TYPE (t) = element_type;
8826
8827 if (TYPE_STRUCTURAL_EQUALITY_P (element_type)
8828 || (domain && TYPE_STRUCTURAL_EQUALITY_P (domain)))
8829 SET_TYPE_STRUCTURAL_EQUALITY (t);
8830 else if (TYPE_CANONICAL (element_type) != element_type
8831 || (domain && TYPE_CANONICAL (domain) != domain))
8832 {
8833 tree unqualified_canon
8834 = build_array_type (TYPE_CANONICAL (element_type),
8835 domain? TYPE_CANONICAL (domain)
8836 : NULL_TREE);
8837 TYPE_CANONICAL (t)
8838 = c_build_qualified_type (unqualified_canon, type_quals);
8839 }
8840 else
8841 TYPE_CANONICAL (t) = t;
8842 }
8843 return t;
8844 }
8845
8846 /* A restrict-qualified pointer type must be a pointer to object or
8847 incomplete type. Note that the use of POINTER_TYPE_P also allows
8848 REFERENCE_TYPEs, which is appropriate for C++. */
8849 if ((type_quals & TYPE_QUAL_RESTRICT)
8850 && (!POINTER_TYPE_P (type)
8851 || !C_TYPE_OBJECT_OR_INCOMPLETE_P (TREE_TYPE (type))))
8852 {
8853 error ("invalid use of %<restrict%>");
8854 type_quals &= ~TYPE_QUAL_RESTRICT;
8855 }
8856
8857 return build_qualified_type (type, type_quals);
8858 }