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[official-gcc.git] / gcc / c-typeck.c
blob28ce2baf1633ef801c18272efa2932dedfc0b454
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
22
23
24 /* This file is part of the C front end.
25 It contains routines to build C expressions given their operands,
26 including computing the types of the result, C-specific error checks,
27 and some optimization. */
28
29 #include "config.h"
30 #include "system.h"
31 #include "coretypes.h"
32 #include "tm.h"
33 #include "rtl.h"
34 #include "tree.h"
35 #include "langhooks.h"
36 #include "c-tree.h"
37 #include "tm_p.h"
38 #include "flags.h"
39 #include "output.h"
40 #include "expr.h"
41 #include "toplev.h"
42 #include "intl.h"
43 #include "ggc.h"
44 #include "target.h"
45 #include "tree-iterator.h"
46 #include "tree-gimple.h"
47 #include "tree-flow.h"
48
49 /* Possible cases of implicit bad conversions. Used to select
50 diagnostic messages in convert_for_assignment. */
51 enum impl_conv {
52 ic_argpass,
53 ic_argpass_nonproto,
54 ic_assign,
55 ic_init,
56 ic_return
57 };
58
59 /* The level of nesting inside "__alignof__". */
60 int in_alignof;
61
62 /* The level of nesting inside "sizeof". */
63 int in_sizeof;
64
65 /* The level of nesting inside "typeof". */
66 int in_typeof;
67
68 struct c_label_context_se *label_context_stack_se;
69 struct c_label_context_vm *label_context_stack_vm;
70
71 /* Nonzero if we've already printed a "missing braces around initializer"
72 message within this initializer. */
73 static int missing_braces_mentioned;
74
75 static int require_constant_value;
76 static int require_constant_elements;
77
78 static bool null_pointer_constant_p (tree);
79 static tree qualify_type (tree, tree);
80 static int tagged_types_tu_compatible_p (tree, tree);
81 static int comp_target_types (tree, tree);
82 static int function_types_compatible_p (tree, tree);
83 static int type_lists_compatible_p (tree, tree);
84 static tree decl_constant_value_for_broken_optimization (tree);
85 static tree lookup_field (tree, tree);
86 static tree convert_arguments (tree, tree, tree, tree);
87 static tree pointer_diff (tree, tree);
88 static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree,
89 int);
90 static tree valid_compound_expr_initializer (tree, tree);
91 static void push_string (const char *);
92 static void push_member_name (tree);
93 static int spelling_length (void);
94 static char *print_spelling (char *);
95 static void warning_init (const char *);
96 static tree digest_init (tree, tree, bool, int);
97 static void output_init_element (tree, bool, tree, tree, int);
98 static void output_pending_init_elements (int);
99 static int set_designator (int);
100 static void push_range_stack (tree);
101 static void add_pending_init (tree, tree);
102 static void set_nonincremental_init (void);
103 static void set_nonincremental_init_from_string (tree);
104 static tree find_init_member (tree);
105 static void readonly_error (tree, enum lvalue_use);
106 static int lvalue_or_else (tree, enum lvalue_use);
107 static int lvalue_p (tree);
108 static void record_maybe_used_decl (tree);
109 static int comptypes_internal (tree, tree);
110 \f
111 /* Return true if EXP is a null pointer constant, false otherwise. */
112
113 static bool
114 null_pointer_constant_p (tree expr)
115 {
116 /* This should really operate on c_expr structures, but they aren't
117 yet available everywhere required. */
118 tree type = TREE_TYPE (expr);
119 return (TREE_CODE (expr) == INTEGER_CST
120 && !TREE_OVERFLOW (expr)
121 && integer_zerop (expr)
122 && (INTEGRAL_TYPE_P (type)
123 || (TREE_CODE (type) == POINTER_TYPE
124 && VOID_TYPE_P (TREE_TYPE (type))
125 && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED)));
126 }
127 \f/* This is a cache to hold if two types are compatible or not. */
128
129 struct tagged_tu_seen_cache {
130 const struct tagged_tu_seen_cache * next;
131 tree t1;
132 tree t2;
133 /* The return value of tagged_types_tu_compatible_p if we had seen
134 these two types already. */
135 int val;
136 };
137
138 static const struct tagged_tu_seen_cache * tagged_tu_seen_base;
139 static void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *);
140
141 /* Do `exp = require_complete_type (exp);' to make sure exp
142 does not have an incomplete type. (That includes void types.) */
143
144 tree
145 require_complete_type (tree value)
146 {
147 tree type = TREE_TYPE (value);
148
149 if (value == error_mark_node || type == error_mark_node)
150 return error_mark_node;
151
152 /* First, detect a valid value with a complete type. */
153 if (COMPLETE_TYPE_P (type))
154 return value;
155
156 c_incomplete_type_error (value, type);
157 return error_mark_node;
158 }
159
160 /* Print an error message for invalid use of an incomplete type.
161 VALUE is the expression that was used (or 0 if that isn't known)
162 and TYPE is the type that was invalid. */
163
164 void
165 c_incomplete_type_error (tree value, tree type)
166 {
167 const char *type_code_string;
168
169 /* Avoid duplicate error message. */
170 if (TREE_CODE (type) == ERROR_MARK)
171 return;
172
173 if (value != 0 && (TREE_CODE (value) == VAR_DECL
174 || TREE_CODE (value) == PARM_DECL))
175 error ("%qD has an incomplete type", value);
176 else
177 {
178 retry:
179 /* We must print an error message. Be clever about what it says. */
180
181 switch (TREE_CODE (type))
182 {
183 case RECORD_TYPE:
184 type_code_string = "struct";
185 break;
186
187 case UNION_TYPE:
188 type_code_string = "union";
189 break;
190
191 case ENUMERAL_TYPE:
192 type_code_string = "enum";
193 break;
194
195 case VOID_TYPE:
196 error ("invalid use of void expression");
197 return;
198
199 case ARRAY_TYPE:
200 if (TYPE_DOMAIN (type))
201 {
202 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
203 {
204 error ("invalid use of flexible array member");
205 return;
206 }
207 type = TREE_TYPE (type);
208 goto retry;
209 }
210 error ("invalid use of array with unspecified bounds");
211 return;
212
213 default:
214 gcc_unreachable ();
215 }
216
217 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
218 error ("invalid use of undefined type %<%s %E%>",
219 type_code_string, TYPE_NAME (type));
220 else
221 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
222 error ("invalid use of incomplete typedef %qD", TYPE_NAME (type));
223 }
224 }
225
226 /* Given a type, apply default promotions wrt unnamed function
227 arguments and return the new type. */
228
229 tree
230 c_type_promotes_to (tree type)
231 {
232 if (TYPE_MAIN_VARIANT (type) == float_type_node)
233 return double_type_node;
234
235 if (c_promoting_integer_type_p (type))
236 {
237 /* Preserve unsignedness if not really getting any wider. */
238 if (TYPE_UNSIGNED (type)
239 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
240 return unsigned_type_node;
241 return integer_type_node;
242 }
243
244 return type;
245 }
246
247 /* Return a variant of TYPE which has all the type qualifiers of LIKE
248 as well as those of TYPE. */
249
250 static tree
251 qualify_type (tree type, tree like)
252 {
253 return c_build_qualified_type (type,
254 TYPE_QUALS (type) | TYPE_QUALS (like));
255 }
256
257 /* Return true iff the given tree T is a variable length array. */
258
259 bool
260 c_vla_type_p (tree t)
261 {
262 if (TREE_CODE (t) == ARRAY_TYPE
263 && C_TYPE_VARIABLE_SIZE (t))
264 return true;
265 return false;
266 }
267 \f
268 /* Return the composite type of two compatible types.
269
270 We assume that comptypes has already been done and returned
271 nonzero; if that isn't so, this may crash. In particular, we
272 assume that qualifiers match. */
273
274 tree
275 composite_type (tree t1, tree t2)
276 {
277 enum tree_code code1;
278 enum tree_code code2;
279 tree attributes;
280
281 /* Save time if the two types are the same. */
282
283 if (t1 == t2) return t1;
284
285 /* If one type is nonsense, use the other. */
286 if (t1 == error_mark_node)
287 return t2;
288 if (t2 == error_mark_node)
289 return t1;
290
291 code1 = TREE_CODE (t1);
292 code2 = TREE_CODE (t2);
293
294 /* Merge the attributes. */
295 attributes = targetm.merge_type_attributes (t1, t2);
296
297 /* If one is an enumerated type and the other is the compatible
298 integer type, the composite type might be either of the two
299 (DR#013 question 3). For consistency, use the enumerated type as
300 the composite type. */
301
302 if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE)
303 return t1;
304 if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE)
305 return t2;
306
307 gcc_assert (code1 == code2);
308
309 switch (code1)
310 {
311 case POINTER_TYPE:
312 /* For two pointers, do this recursively on the target type. */
313 {
314 tree pointed_to_1 = TREE_TYPE (t1);
315 tree pointed_to_2 = TREE_TYPE (t2);
316 tree target = composite_type (pointed_to_1, pointed_to_2);
317 t1 = build_pointer_type (target);
318 t1 = build_type_attribute_variant (t1, attributes);
319 return qualify_type (t1, t2);
320 }
321
322 case ARRAY_TYPE:
323 {
324 tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
325 int quals;
326 tree unqual_elt;
327 tree d1 = TYPE_DOMAIN (t1);
328 tree d2 = TYPE_DOMAIN (t2);
329 bool d1_variable, d2_variable;
330 bool d1_zero, d2_zero;
331
332 /* We should not have any type quals on arrays at all. */
333 gcc_assert (!TYPE_QUALS (t1) && !TYPE_QUALS (t2));
334
335 d1_zero = d1 == 0 || !TYPE_MAX_VALUE (d1);
336 d2_zero = d2 == 0 || !TYPE_MAX_VALUE (d2);
337
338 d1_variable = (!d1_zero
339 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
340 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
341 d2_variable = (!d2_zero
342 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
343 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
344 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
345 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
346
347 /* Save space: see if the result is identical to one of the args. */
348 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)
349 && (d2_variable || d2_zero || !d1_variable))
350 return build_type_attribute_variant (t1, attributes);
351 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)
352 && (d1_variable || d1_zero || !d2_variable))
353 return build_type_attribute_variant (t2, attributes);
354
355 if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
356 return build_type_attribute_variant (t1, attributes);
357 if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
358 return build_type_attribute_variant (t2, attributes);
359
360 /* Merge the element types, and have a size if either arg has
361 one. We may have qualifiers on the element types. To set
362 up TYPE_MAIN_VARIANT correctly, we need to form the
363 composite of the unqualified types and add the qualifiers
364 back at the end. */
365 quals = TYPE_QUALS (strip_array_types (elt));
366 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
367 t1 = build_array_type (unqual_elt,
368 TYPE_DOMAIN ((TYPE_DOMAIN (t1)
369 && (d2_variable
370 || d2_zero
371 || !d1_variable))
372 ? t1
373 : t2));
374 t1 = c_build_qualified_type (t1, quals);
375 return build_type_attribute_variant (t1, attributes);
376 }
377
378 case ENUMERAL_TYPE:
379 case RECORD_TYPE:
380 case UNION_TYPE:
381 if (attributes != NULL)
382 {
383 /* Try harder not to create a new aggregate type. */
384 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
385 return t1;
386 if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
387 return t2;
388 }
389 return build_type_attribute_variant (t1, attributes);
390
391 case FUNCTION_TYPE:
392 /* Function types: prefer the one that specified arg types.
393 If both do, merge the arg types. Also merge the return types. */
394 {
395 tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
396 tree p1 = TYPE_ARG_TYPES (t1);
397 tree p2 = TYPE_ARG_TYPES (t2);
398 int len;
399 tree newargs, n;
400 int i;
401
402 /* Save space: see if the result is identical to one of the args. */
403 if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2))
404 return build_type_attribute_variant (t1, attributes);
405 if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1))
406 return build_type_attribute_variant (t2, attributes);
407
408 /* Simple way if one arg fails to specify argument types. */
409 if (TYPE_ARG_TYPES (t1) == 0)
410 {
411 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
412 t1 = build_type_attribute_variant (t1, attributes);
413 return qualify_type (t1, t2);
414 }
415 if (TYPE_ARG_TYPES (t2) == 0)
416 {
417 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
418 t1 = build_type_attribute_variant (t1, attributes);
419 return qualify_type (t1, t2);
420 }
421
422 /* If both args specify argument types, we must merge the two
423 lists, argument by argument. */
424 /* Tell global_bindings_p to return false so that variable_size
425 doesn't die on VLAs in parameter types. */
426 c_override_global_bindings_to_false = true;
427
428 len = list_length (p1);
429 newargs = 0;
430
431 for (i = 0; i < len; i++)
432 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
433
434 n = newargs;
435
436 for (; p1;
437 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
438 {
439 /* A null type means arg type is not specified.
440 Take whatever the other function type has. */
441 if (TREE_VALUE (p1) == 0)
442 {
443 TREE_VALUE (n) = TREE_VALUE (p2);
444 goto parm_done;
445 }
446 if (TREE_VALUE (p2) == 0)
447 {
448 TREE_VALUE (n) = TREE_VALUE (p1);
449 goto parm_done;
450 }
451
452 /* Given wait (union {union wait *u; int *i} *)
453 and wait (union wait *),
454 prefer union wait * as type of parm. */
455 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
456 && TREE_VALUE (p1) != TREE_VALUE (p2))
457 {
458 tree memb;
459 tree mv2 = TREE_VALUE (p2);
460 if (mv2 && mv2 != error_mark_node
461 && TREE_CODE (mv2) != ARRAY_TYPE)
462 mv2 = TYPE_MAIN_VARIANT (mv2);
463 for (memb = TYPE_FIELDS (TREE_VALUE (p1));
464 memb; memb = TREE_CHAIN (memb))
465 {
466 tree mv3 = TREE_TYPE (memb);
467 if (mv3 && mv3 != error_mark_node
468 && TREE_CODE (mv3) != ARRAY_TYPE)
469 mv3 = TYPE_MAIN_VARIANT (mv3);
470 if (comptypes (mv3, mv2))
471 {
472 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
473 TREE_VALUE (p2));
474 if (pedantic)
475 pedwarn ("function types not truly compatible in ISO C");
476 goto parm_done;
477 }
478 }
479 }
480 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
481 && TREE_VALUE (p2) != TREE_VALUE (p1))
482 {
483 tree memb;
484 tree mv1 = TREE_VALUE (p1);
485 if (mv1 && mv1 != error_mark_node
486 && TREE_CODE (mv1) != ARRAY_TYPE)
487 mv1 = TYPE_MAIN_VARIANT (mv1);
488 for (memb = TYPE_FIELDS (TREE_VALUE (p2));
489 memb; memb = TREE_CHAIN (memb))
490 {
491 tree mv3 = TREE_TYPE (memb);
492 if (mv3 && mv3 != error_mark_node
493 && TREE_CODE (mv3) != ARRAY_TYPE)
494 mv3 = TYPE_MAIN_VARIANT (mv3);
495 if (comptypes (mv3, mv1))
496 {
497 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
498 TREE_VALUE (p1));
499 if (pedantic)
500 pedwarn ("function types not truly compatible in ISO C");
501 goto parm_done;
502 }
503 }
504 }
505 TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2));
506 parm_done: ;
507 }
508
509 c_override_global_bindings_to_false = false;
510 t1 = build_function_type (valtype, newargs);
511 t1 = qualify_type (t1, t2);
512 /* ... falls through ... */
513 }
514
515 default:
516 return build_type_attribute_variant (t1, attributes);
517 }
518
519 }
520
521 /* Return the type of a conditional expression between pointers to
522 possibly differently qualified versions of compatible types.
523
524 We assume that comp_target_types has already been done and returned
525 nonzero; if that isn't so, this may crash. */
526
527 static tree
528 common_pointer_type (tree t1, tree t2)
529 {
530 tree attributes;
531 tree pointed_to_1, mv1;
532 tree pointed_to_2, mv2;
533 tree target;
534
535 /* Save time if the two types are the same. */
536
537 if (t1 == t2) return t1;
538
539 /* If one type is nonsense, use the other. */
540 if (t1 == error_mark_node)
541 return t2;
542 if (t2 == error_mark_node)
543 return t1;
544
545 gcc_assert (TREE_CODE (t1) == POINTER_TYPE
546 && TREE_CODE (t2) == POINTER_TYPE);
547
548 /* Merge the attributes. */
549 attributes = targetm.merge_type_attributes (t1, t2);
550
551 /* Find the composite type of the target types, and combine the
552 qualifiers of the two types' targets. Do not lose qualifiers on
553 array element types by taking the TYPE_MAIN_VARIANT. */
554 mv1 = pointed_to_1 = TREE_TYPE (t1);
555 mv2 = pointed_to_2 = TREE_TYPE (t2);
556 if (TREE_CODE (mv1) != ARRAY_TYPE)
557 mv1 = TYPE_MAIN_VARIANT (pointed_to_1);
558 if (TREE_CODE (mv2) != ARRAY_TYPE)
559 mv2 = TYPE_MAIN_VARIANT (pointed_to_2);
560 target = composite_type (mv1, mv2);
561 t1 = build_pointer_type (c_build_qualified_type
562 (target,
563 TYPE_QUALS (pointed_to_1) |
564 TYPE_QUALS (pointed_to_2)));
565 return build_type_attribute_variant (t1, attributes);
566 }
567
568 /* Return the common type for two arithmetic types under the usual
569 arithmetic conversions. The default conversions have already been
570 applied, and enumerated types converted to their compatible integer
571 types. The resulting type is unqualified and has no attributes.
572
573 This is the type for the result of most arithmetic operations
574 if the operands have the given two types. */
575
576 static tree
577 c_common_type (tree t1, tree t2)
578 {
579 enum tree_code code1;
580 enum tree_code code2;
581
582 /* If one type is nonsense, use the other. */
583 if (t1 == error_mark_node)
584 return t2;
585 if (t2 == error_mark_node)
586 return t1;
587
588 if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED)
589 t1 = TYPE_MAIN_VARIANT (t1);
590
591 if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED)
592 t2 = TYPE_MAIN_VARIANT (t2);
593
594 if (TYPE_ATTRIBUTES (t1) != NULL_TREE)
595 t1 = build_type_attribute_variant (t1, NULL_TREE);
596
597 if (TYPE_ATTRIBUTES (t2) != NULL_TREE)
598 t2 = build_type_attribute_variant (t2, NULL_TREE);
599
600 /* Save time if the two types are the same. */
601
602 if (t1 == t2) return t1;
603
604 code1 = TREE_CODE (t1);
605 code2 = TREE_CODE (t2);
606
607 gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE
608 || code1 == REAL_TYPE || code1 == INTEGER_TYPE);
609 gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE
610 || code2 == REAL_TYPE || code2 == INTEGER_TYPE);
611
612 /* When one operand is a decimal float type, the other operand cannot be
613 a generic float type or a complex type. We also disallow vector types
614 here. */
615 if ((DECIMAL_FLOAT_TYPE_P (t1) || DECIMAL_FLOAT_TYPE_P (t2))
616 && !(DECIMAL_FLOAT_TYPE_P (t1) && DECIMAL_FLOAT_TYPE_P (t2)))
617 {
618 if (code1 == VECTOR_TYPE || code2 == VECTOR_TYPE)
619 {
620 error ("can%'t mix operands of decimal float and vector types");
621 return error_mark_node;
622 }
623 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
624 {
625 error ("can%'t mix operands of decimal float and complex types");
626 return error_mark_node;
627 }
628 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
629 {
630 error ("can%'t mix operands of decimal float and other float types");
631 return error_mark_node;
632 }
633 }
634
635 /* If one type is a vector type, return that type. (How the usual
636 arithmetic conversions apply to the vector types extension is not
637 precisely specified.) */
638 if (code1 == VECTOR_TYPE)
639 return t1;
640
641 if (code2 == VECTOR_TYPE)
642 return t2;
643
644 /* If one type is complex, form the common type of the non-complex
645 components, then make that complex. Use T1 or T2 if it is the
646 required type. */
647 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
648 {
649 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
650 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
651 tree subtype = c_common_type (subtype1, subtype2);
652
653 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
654 return t1;
655 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
656 return t2;
657 else
658 return build_complex_type (subtype);
659 }
660
661 /* If only one is real, use it as the result. */
662
663 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
664 return t1;
665
666 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
667 return t2;
668
669 /* If both are real and either are decimal floating point types, use
670 the decimal floating point type with the greater precision. */
671
672 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
673 {
674 if (TYPE_MAIN_VARIANT (t1) == dfloat128_type_node
675 || TYPE_MAIN_VARIANT (t2) == dfloat128_type_node)
676 return dfloat128_type_node;
677 else if (TYPE_MAIN_VARIANT (t1) == dfloat64_type_node
678 || TYPE_MAIN_VARIANT (t2) == dfloat64_type_node)
679 return dfloat64_type_node;
680 else if (TYPE_MAIN_VARIANT (t1) == dfloat32_type_node
681 || TYPE_MAIN_VARIANT (t2) == dfloat32_type_node)
682 return dfloat32_type_node;
683 }
684
685 /* Both real or both integers; use the one with greater precision. */
686
687 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
688 return t1;
689 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
690 return t2;
691
692 /* Same precision. Prefer long longs to longs to ints when the
693 same precision, following the C99 rules on integer type rank
694 (which are equivalent to the C90 rules for C90 types). */
695
696 if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node
697 || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node)
698 return long_long_unsigned_type_node;
699
700 if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node
701 || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node)
702 {
703 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
704 return long_long_unsigned_type_node;
705 else
706 return long_long_integer_type_node;
707 }
708
709 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
710 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
711 return long_unsigned_type_node;
712
713 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
714 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
715 {
716 /* But preserve unsignedness from the other type,
717 since long cannot hold all the values of an unsigned int. */
718 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
719 return long_unsigned_type_node;
720 else
721 return long_integer_type_node;
722 }
723
724 /* Likewise, prefer long double to double even if same size. */
725 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
726 || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
727 return long_double_type_node;
728
729 /* Otherwise prefer the unsigned one. */
730
731 if (TYPE_UNSIGNED (t1))
732 return t1;
733 else
734 return t2;
735 }
736 \f
737 /* Wrapper around c_common_type that is used by c-common.c and other
738 front end optimizations that remove promotions. ENUMERAL_TYPEs
739 are allowed here and are converted to their compatible integer types.
740 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
741 preferably a non-Boolean type as the common type. */
742 tree
743 common_type (tree t1, tree t2)
744 {
745 if (TREE_CODE (t1) == ENUMERAL_TYPE)
746 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
747 if (TREE_CODE (t2) == ENUMERAL_TYPE)
748 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
749
750 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
751 if (TREE_CODE (t1) == BOOLEAN_TYPE
752 && TREE_CODE (t2) == BOOLEAN_TYPE)
753 return boolean_type_node;
754
755 /* If either type is BOOLEAN_TYPE, then return the other. */
756 if (TREE_CODE (t1) == BOOLEAN_TYPE)
757 return t2;
758 if (TREE_CODE (t2) == BOOLEAN_TYPE)
759 return t1;
760
761 return c_common_type (t1, t2);
762 }
763
764 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
765 or various other operations. Return 2 if they are compatible
766 but a warning may be needed if you use them together. */
767
768 int
769 comptypes (tree type1, tree type2)
770 {
771 const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base;
772 int val;
773
774 val = comptypes_internal (type1, type2);
775 free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1);
776
777 return val;
778 }
779 \f
780 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
781 or various other operations. Return 2 if they are compatible
782 but a warning may be needed if you use them together. This
783 differs from comptypes, in that we don't free the seen types. */
784
785 static int
786 comptypes_internal (tree type1, tree type2)
787 {
788 tree t1 = type1;
789 tree t2 = type2;
790 int attrval, val;
791
792 /* Suppress errors caused by previously reported errors. */
793
794 if (t1 == t2 || !t1 || !t2
795 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
796 return 1;
797
798 /* If either type is the internal version of sizetype, return the
799 language version. */
800 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
801 && TYPE_ORIG_SIZE_TYPE (t1))
802 t1 = TYPE_ORIG_SIZE_TYPE (t1);
803
804 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
805 && TYPE_ORIG_SIZE_TYPE (t2))
806 t2 = TYPE_ORIG_SIZE_TYPE (t2);
807
808
809 /* Enumerated types are compatible with integer types, but this is
810 not transitive: two enumerated types in the same translation unit
811 are compatible with each other only if they are the same type. */
812
813 if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE)
814 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1));
815 else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE)
816 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2));
817
818 if (t1 == t2)
819 return 1;
820
821 /* Different classes of types can't be compatible. */
822
823 if (TREE_CODE (t1) != TREE_CODE (t2))
824 return 0;
825
826 /* Qualifiers must match. C99 6.7.3p9 */
827
828 if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
829 return 0;
830
831 /* Allow for two different type nodes which have essentially the same
832 definition. Note that we already checked for equality of the type
833 qualifiers (just above). */
834
835 if (TREE_CODE (t1) != ARRAY_TYPE
836 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
837 return 1;
838
839 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
840 if (!(attrval = targetm.comp_type_attributes (t1, t2)))
841 return 0;
842
843 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
844 val = 0;
845
846 switch (TREE_CODE (t1))
847 {
848 case POINTER_TYPE:
849 /* Do not remove mode or aliasing information. */
850 if (TYPE_MODE (t1) != TYPE_MODE (t2)
851 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2))
852 break;
853 val = (TREE_TYPE (t1) == TREE_TYPE (t2)
854 ? 1 : comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2)));
855 break;
856
857 case FUNCTION_TYPE:
858 val = function_types_compatible_p (t1, t2);
859 break;
860
861 case ARRAY_TYPE:
862 {
863 tree d1 = TYPE_DOMAIN (t1);
864 tree d2 = TYPE_DOMAIN (t2);
865 bool d1_variable, d2_variable;
866 bool d1_zero, d2_zero;
867 val = 1;
868
869 /* Target types must match incl. qualifiers. */
870 if (TREE_TYPE (t1) != TREE_TYPE (t2)
871 && 0 == (val = comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2))))
872 return 0;
873
874 /* Sizes must match unless one is missing or variable. */
875 if (d1 == 0 || d2 == 0 || d1 == d2)
876 break;
877
878 d1_zero = !TYPE_MAX_VALUE (d1);
879 d2_zero = !TYPE_MAX_VALUE (d2);
880
881 d1_variable = (!d1_zero
882 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
883 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
884 d2_variable = (!d2_zero
885 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
886 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
887 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
888 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
889
890 if (d1_variable || d2_variable)
891 break;
892 if (d1_zero && d2_zero)
893 break;
894 if (d1_zero || d2_zero
895 || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
896 || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
897 val = 0;
898
899 break;
900 }
901
902 case ENUMERAL_TYPE:
903 case RECORD_TYPE:
904 case UNION_TYPE:
905 if (val != 1 && !same_translation_unit_p (t1, t2))
906 {
907 tree a1 = TYPE_ATTRIBUTES (t1);
908 tree a2 = TYPE_ATTRIBUTES (t2);
909
910 if (! attribute_list_contained (a1, a2)
911 && ! attribute_list_contained (a2, a1))
912 break;
913
914 if (attrval != 2)
915 return tagged_types_tu_compatible_p (t1, t2);
916 val = tagged_types_tu_compatible_p (t1, t2);
917 }
918 break;
919
920 case VECTOR_TYPE:
921 val = TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
922 && comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2));
923 break;
924
925 default:
926 break;
927 }
928 return attrval == 2 && val == 1 ? 2 : val;
929 }
930
931 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
932 ignoring their qualifiers. */
933
934 static int
935 comp_target_types (tree ttl, tree ttr)
936 {
937 int val;
938 tree mvl, mvr;
939
940 /* Do not lose qualifiers on element types of array types that are
941 pointer targets by taking their TYPE_MAIN_VARIANT. */
942 mvl = TREE_TYPE (ttl);
943 mvr = TREE_TYPE (ttr);
944 if (TREE_CODE (mvl) != ARRAY_TYPE)
945 mvl = TYPE_MAIN_VARIANT (mvl);
946 if (TREE_CODE (mvr) != ARRAY_TYPE)
947 mvr = TYPE_MAIN_VARIANT (mvr);
948 val = comptypes (mvl, mvr);
949
950 if (val == 2 && pedantic)
951 pedwarn ("types are not quite compatible");
952 return val;
953 }
954 \f
955 /* Subroutines of `comptypes'. */
956
957 /* Determine whether two trees derive from the same translation unit.
958 If the CONTEXT chain ends in a null, that tree's context is still
959 being parsed, so if two trees have context chains ending in null,
960 they're in the same translation unit. */
961 int
962 same_translation_unit_p (tree t1, tree t2)
963 {
964 while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL)
965 switch (TREE_CODE_CLASS (TREE_CODE (t1)))
966 {
967 case tcc_declaration:
968 t1 = DECL_CONTEXT (t1); break;
969 case tcc_type:
970 t1 = TYPE_CONTEXT (t1); break;
971 case tcc_exceptional:
972 t1 = BLOCK_SUPERCONTEXT (t1); break; /* assume block */
973 default: gcc_unreachable ();
974 }
975
976 while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL)
977 switch (TREE_CODE_CLASS (TREE_CODE (t2)))
978 {
979 case tcc_declaration:
980 t2 = DECL_CONTEXT (t2); break;
981 case tcc_type:
982 t2 = TYPE_CONTEXT (t2); break;
983 case tcc_exceptional:
984 t2 = BLOCK_SUPERCONTEXT (t2); break; /* assume block */
985 default: gcc_unreachable ();
986 }
987
988 return t1 == t2;
989 }
990
991 /* Allocate the seen two types, assuming that they are compatible. */
992
993 static struct tagged_tu_seen_cache *
994 alloc_tagged_tu_seen_cache (tree t1, tree t2)
995 {
996 struct tagged_tu_seen_cache *tu = XNEW (struct tagged_tu_seen_cache);
997 tu->next = tagged_tu_seen_base;
998 tu->t1 = t1;
999 tu->t2 = t2;
1000
1001 tagged_tu_seen_base = tu;
1002
1003 /* The C standard says that two structures in different translation
1004 units are compatible with each other only if the types of their
1005 fields are compatible (among other things). We assume that they
1006 are compatible until proven otherwise when building the cache.
1007 An example where this can occur is:
1008 struct a
1009 {
1010 struct a *next;
1011 };
1012 If we are comparing this against a similar struct in another TU,
1013 and did not assume they were compatible, we end up with an infinite
1014 loop. */
1015 tu->val = 1;
1016 return tu;
1017 }
1018
1019 /* Free the seen types until we get to TU_TIL. */
1020
1021 static void
1022 free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *tu_til)
1023 {
1024 const struct tagged_tu_seen_cache *tu = tagged_tu_seen_base;
1025 while (tu != tu_til)
1026 {
1027 struct tagged_tu_seen_cache *tu1 = (struct tagged_tu_seen_cache*)tu;
1028 tu = tu1->next;
1029 free (tu1);
1030 }
1031 tagged_tu_seen_base = tu_til;
1032 }
1033
1034 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1035 compatible. If the two types are not the same (which has been
1036 checked earlier), this can only happen when multiple translation
1037 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1038 rules. */
1039
1040 static int
1041 tagged_types_tu_compatible_p (tree t1, tree t2)
1042 {
1043 tree s1, s2;
1044 bool needs_warning = false;
1045
1046 /* We have to verify that the tags of the types are the same. This
1047 is harder than it looks because this may be a typedef, so we have
1048 to go look at the original type. It may even be a typedef of a
1049 typedef...
1050 In the case of compiler-created builtin structs the TYPE_DECL
1051 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1052 while (TYPE_NAME (t1)
1053 && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL
1054 && DECL_ORIGINAL_TYPE (TYPE_NAME (t1)))
1055 t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1));
1056
1057 while (TYPE_NAME (t2)
1058 && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL
1059 && DECL_ORIGINAL_TYPE (TYPE_NAME (t2)))
1060 t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2));
1061
1062 /* C90 didn't have the requirement that the two tags be the same. */
1063 if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2))
1064 return 0;
1065
1066 /* C90 didn't say what happened if one or both of the types were
1067 incomplete; we choose to follow C99 rules here, which is that they
1068 are compatible. */
1069 if (TYPE_SIZE (t1) == NULL
1070 || TYPE_SIZE (t2) == NULL)
1071 return 1;
1072
1073 {
1074 const struct tagged_tu_seen_cache * tts_i;
1075 for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next)
1076 if (tts_i->t1 == t1 && tts_i->t2 == t2)
1077 return tts_i->val;
1078 }
1079
1080 switch (TREE_CODE (t1))
1081 {
1082 case ENUMERAL_TYPE:
1083 {
1084 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1085 /* Speed up the case where the type values are in the same order. */
1086 tree tv1 = TYPE_VALUES (t1);
1087 tree tv2 = TYPE_VALUES (t2);
1088
1089 if (tv1 == tv2)
1090 {
1091 return 1;
1092 }
1093
1094 for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2))
1095 {
1096 if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2))
1097 break;
1098 if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1)
1099 {
1100 tu->val = 0;
1101 return 0;
1102 }
1103 }
1104
1105 if (tv1 == NULL_TREE && tv2 == NULL_TREE)
1106 {
1107 return 1;
1108 }
1109 if (tv1 == NULL_TREE || tv2 == NULL_TREE)
1110 {
1111 tu->val = 0;
1112 return 0;
1113 }
1114
1115 if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2)))
1116 {
1117 tu->val = 0;
1118 return 0;
1119 }
1120
1121 for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1))
1122 {
1123 s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2));
1124 if (s2 == NULL
1125 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1)
1126 {
1127 tu->val = 0;
1128 return 0;
1129 }
1130 }
1131 return 1;
1132 }
1133
1134 case UNION_TYPE:
1135 {
1136 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1137 if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2)))
1138 {
1139 tu->val = 0;
1140 return 0;
1141 }
1142
1143 /* Speed up the common case where the fields are in the same order. */
1144 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2;
1145 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1146 {
1147 int result;
1148
1149
1150 if (DECL_NAME (s1) == NULL
1151 || DECL_NAME (s1) != DECL_NAME (s2))
1152 break;
1153 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1154 if (result == 0)
1155 {
1156 tu->val = 0;
1157 return 0;
1158 }
1159 if (result == 2)
1160 needs_warning = true;
1161
1162 if (TREE_CODE (s1) == FIELD_DECL
1163 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1164 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1165 {
1166 tu->val = 0;
1167 return 0;
1168 }
1169 }
1170 if (!s1 && !s2)
1171 {
1172 tu->val = needs_warning ? 2 : 1;
1173 return tu->val;
1174 }
1175
1176 for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1))
1177 {
1178 bool ok = false;
1179
1180 if (DECL_NAME (s1) != NULL)
1181 for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2))
1182 if (DECL_NAME (s1) == DECL_NAME (s2))
1183 {
1184 int result;
1185 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1186 if (result == 0)
1187 {
1188 tu->val = 0;
1189 return 0;
1190 }
1191 if (result == 2)
1192 needs_warning = true;
1193
1194 if (TREE_CODE (s1) == FIELD_DECL
1195 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1196 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1197 break;
1198
1199 ok = true;
1200 break;
1201 }
1202 if (!ok)
1203 {
1204 tu->val = 0;
1205 return 0;
1206 }
1207 }
1208 tu->val = needs_warning ? 2 : 10;
1209 return tu->val;
1210 }
1211
1212 case RECORD_TYPE:
1213 {
1214 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1215
1216 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2);
1217 s1 && s2;
1218 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1219 {
1220 int result;
1221 if (TREE_CODE (s1) != TREE_CODE (s2)
1222 || DECL_NAME (s1) != DECL_NAME (s2))
1223 break;
1224 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1225 if (result == 0)
1226 break;
1227 if (result == 2)
1228 needs_warning = true;
1229
1230 if (TREE_CODE (s1) == FIELD_DECL
1231 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1232 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1233 break;
1234 }
1235 if (s1 && s2)
1236 tu->val = 0;
1237 else
1238 tu->val = needs_warning ? 2 : 1;
1239 return tu->val;
1240 }
1241
1242 default:
1243 gcc_unreachable ();
1244 }
1245 }
1246
1247 /* Return 1 if two function types F1 and F2 are compatible.
1248 If either type specifies no argument types,
1249 the other must specify a fixed number of self-promoting arg types.
1250 Otherwise, if one type specifies only the number of arguments,
1251 the other must specify that number of self-promoting arg types.
1252 Otherwise, the argument types must match. */
1253
1254 static int
1255 function_types_compatible_p (tree f1, tree f2)
1256 {
1257 tree args1, args2;
1258 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1259 int val = 1;
1260 int val1;
1261 tree ret1, ret2;
1262
1263 ret1 = TREE_TYPE (f1);
1264 ret2 = TREE_TYPE (f2);
1265
1266 /* 'volatile' qualifiers on a function's return type used to mean
1267 the function is noreturn. */
1268 if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2))
1269 pedwarn ("function return types not compatible due to %<volatile%>");
1270 if (TYPE_VOLATILE (ret1))
1271 ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1),
1272 TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE);
1273 if (TYPE_VOLATILE (ret2))
1274 ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2),
1275 TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE);
1276 val = comptypes_internal (ret1, ret2);
1277 if (val == 0)
1278 return 0;
1279
1280 args1 = TYPE_ARG_TYPES (f1);
1281 args2 = TYPE_ARG_TYPES (f2);
1282
1283 /* An unspecified parmlist matches any specified parmlist
1284 whose argument types don't need default promotions. */
1285
1286 if (args1 == 0)
1287 {
1288 if (!self_promoting_args_p (args2))
1289 return 0;
1290 /* If one of these types comes from a non-prototype fn definition,
1291 compare that with the other type's arglist.
1292 If they don't match, ask for a warning (but no error). */
1293 if (TYPE_ACTUAL_ARG_TYPES (f1)
1294 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
1295 val = 2;
1296 return val;
1297 }
1298 if (args2 == 0)
1299 {
1300 if (!self_promoting_args_p (args1))
1301 return 0;
1302 if (TYPE_ACTUAL_ARG_TYPES (f2)
1303 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
1304 val = 2;
1305 return val;
1306 }
1307
1308 /* Both types have argument lists: compare them and propagate results. */
1309 val1 = type_lists_compatible_p (args1, args2);
1310 return val1 != 1 ? val1 : val;
1311 }
1312
1313 /* Check two lists of types for compatibility,
1314 returning 0 for incompatible, 1 for compatible,
1315 or 2 for compatible with warning. */
1316
1317 static int
1318 type_lists_compatible_p (tree args1, tree args2)
1319 {
1320 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1321 int val = 1;
1322 int newval = 0;
1323
1324 while (1)
1325 {
1326 tree a1, mv1, a2, mv2;
1327 if (args1 == 0 && args2 == 0)
1328 return val;
1329 /* If one list is shorter than the other,
1330 they fail to match. */
1331 if (args1 == 0 || args2 == 0)
1332 return 0;
1333 mv1 = a1 = TREE_VALUE (args1);
1334 mv2 = a2 = TREE_VALUE (args2);
1335 if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE)
1336 mv1 = TYPE_MAIN_VARIANT (mv1);
1337 if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE)
1338 mv2 = TYPE_MAIN_VARIANT (mv2);
1339 /* A null pointer instead of a type
1340 means there is supposed to be an argument
1341 but nothing is specified about what type it has.
1342 So match anything that self-promotes. */
1343 if (a1 == 0)
1344 {
1345 if (c_type_promotes_to (a2) != a2)
1346 return 0;
1347 }
1348 else if (a2 == 0)
1349 {
1350 if (c_type_promotes_to (a1) != a1)
1351 return 0;
1352 }
1353 /* If one of the lists has an error marker, ignore this arg. */
1354 else if (TREE_CODE (a1) == ERROR_MARK
1355 || TREE_CODE (a2) == ERROR_MARK)
1356 ;
1357 else if (!(newval = comptypes_internal (mv1, mv2)))
1358 {
1359 /* Allow wait (union {union wait *u; int *i} *)
1360 and wait (union wait *) to be compatible. */
1361 if (TREE_CODE (a1) == UNION_TYPE
1362 && (TYPE_NAME (a1) == 0
1363 || TYPE_TRANSPARENT_UNION (a1))
1364 && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST
1365 && tree_int_cst_equal (TYPE_SIZE (a1),
1366 TYPE_SIZE (a2)))
1367 {
1368 tree memb;
1369 for (memb = TYPE_FIELDS (a1);
1370 memb; memb = TREE_CHAIN (memb))
1371 {
1372 tree mv3 = TREE_TYPE (memb);
1373 if (mv3 && mv3 != error_mark_node
1374 && TREE_CODE (mv3) != ARRAY_TYPE)
1375 mv3 = TYPE_MAIN_VARIANT (mv3);
1376 if (comptypes_internal (mv3, mv2))
1377 break;
1378 }
1379 if (memb == 0)
1380 return 0;
1381 }
1382 else if (TREE_CODE (a2) == UNION_TYPE
1383 && (TYPE_NAME (a2) == 0
1384 || TYPE_TRANSPARENT_UNION (a2))
1385 && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST
1386 && tree_int_cst_equal (TYPE_SIZE (a2),
1387 TYPE_SIZE (a1)))
1388 {
1389 tree memb;
1390 for (memb = TYPE_FIELDS (a2);
1391 memb; memb = TREE_CHAIN (memb))
1392 {
1393 tree mv3 = TREE_TYPE (memb);
1394 if (mv3 && mv3 != error_mark_node
1395 && TREE_CODE (mv3) != ARRAY_TYPE)
1396 mv3 = TYPE_MAIN_VARIANT (mv3);
1397 if (comptypes_internal (mv3, mv1))
1398 break;
1399 }
1400 if (memb == 0)
1401 return 0;
1402 }
1403 else
1404 return 0;
1405 }
1406
1407 /* comptypes said ok, but record if it said to warn. */
1408 if (newval > val)
1409 val = newval;
1410
1411 args1 = TREE_CHAIN (args1);
1412 args2 = TREE_CHAIN (args2);
1413 }
1414 }
1415 \f
1416 /* Compute the size to increment a pointer by. */
1417
1418 static tree
1419 c_size_in_bytes (tree type)
1420 {
1421 enum tree_code code = TREE_CODE (type);
1422
1423 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
1424 return size_one_node;
1425
1426 if (!COMPLETE_OR_VOID_TYPE_P (type))
1427 {
1428 error ("arithmetic on pointer to an incomplete type");
1429 return size_one_node;
1430 }
1431
1432 /* Convert in case a char is more than one unit. */
1433 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
1434 size_int (TYPE_PRECISION (char_type_node)
1435 / BITS_PER_UNIT));
1436 }
1437 \f
1438 /* Return either DECL or its known constant value (if it has one). */
1439
1440 tree
1441 decl_constant_value (tree decl)
1442 {
1443 if (/* Don't change a variable array bound or initial value to a constant
1444 in a place where a variable is invalid. Note that DECL_INITIAL
1445 isn't valid for a PARM_DECL. */
1446 current_function_decl != 0
1447 && TREE_CODE (decl) != PARM_DECL
1448 && !TREE_THIS_VOLATILE (decl)
1449 && TREE_READONLY (decl)
1450 && DECL_INITIAL (decl) != 0
1451 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
1452 /* This is invalid if initial value is not constant.
1453 If it has either a function call, a memory reference,
1454 or a variable, then re-evaluating it could give different results. */
1455 && TREE_CONSTANT (DECL_INITIAL (decl))
1456 /* Check for cases where this is sub-optimal, even though valid. */
1457 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
1458 return DECL_INITIAL (decl);
1459 return decl;
1460 }
1461
1462 /* Return either DECL or its known constant value (if it has one), but
1463 return DECL if pedantic or DECL has mode BLKmode. This is for
1464 bug-compatibility with the old behavior of decl_constant_value
1465 (before GCC 3.0); every use of this function is a bug and it should
1466 be removed before GCC 3.1. It is not appropriate to use pedantic
1467 in a way that affects optimization, and BLKmode is probably not the
1468 right test for avoiding misoptimizations either. */
1469
1470 static tree
1471 decl_constant_value_for_broken_optimization (tree decl)
1472 {
1473 tree ret;
1474
1475 if (pedantic || DECL_MODE (decl) == BLKmode)
1476 return decl;
1477
1478 ret = decl_constant_value (decl);
1479 /* Avoid unwanted tree sharing between the initializer and current
1480 function's body where the tree can be modified e.g. by the
1481 gimplifier. */
1482 if (ret != decl && TREE_STATIC (decl))
1483 ret = unshare_expr (ret);
1484 return ret;
1485 }
1486
1487 /* Convert the array expression EXP to a pointer. */
1488 static tree
1489 array_to_pointer_conversion (tree exp)
1490 {
1491 tree orig_exp = exp;
1492 tree type = TREE_TYPE (exp);
1493 tree adr;
1494 tree restype = TREE_TYPE (type);
1495 tree ptrtype;
1496
1497 gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
1498
1499 STRIP_TYPE_NOPS (exp);
1500
1501 if (TREE_NO_WARNING (orig_exp))
1502 TREE_NO_WARNING (exp) = 1;
1503
1504 ptrtype = build_pointer_type (restype);
1505
1506 if (TREE_CODE (exp) == INDIRECT_REF)
1507 return convert (ptrtype, TREE_OPERAND (exp, 0));
1508
1509 if (TREE_CODE (exp) == VAR_DECL)
1510 {
1511 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1512 ADDR_EXPR because it's the best way of representing what
1513 happens in C when we take the address of an array and place
1514 it in a pointer to the element type. */
1515 adr = build1 (ADDR_EXPR, ptrtype, exp);
1516 if (!c_mark_addressable (exp))
1517 return error_mark_node;
1518 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
1519 return adr;
1520 }
1521
1522 /* This way is better for a COMPONENT_REF since it can
1523 simplify the offset for a component. */
1524 adr = build_unary_op (ADDR_EXPR, exp, 1);
1525 return convert (ptrtype, adr);
1526 }
1527
1528 /* Convert the function expression EXP to a pointer. */
1529 static tree
1530 function_to_pointer_conversion (tree exp)
1531 {
1532 tree orig_exp = exp;
1533
1534 gcc_assert (TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE);
1535
1536 STRIP_TYPE_NOPS (exp);
1537
1538 if (TREE_NO_WARNING (orig_exp))
1539 TREE_NO_WARNING (exp) = 1;
1540
1541 return build_unary_op (ADDR_EXPR, exp, 0);
1542 }
1543
1544 /* Perform the default conversion of arrays and functions to pointers.
1545 Return the result of converting EXP. For any other expression, just
1546 return EXP after removing NOPs. */
1547
1548 struct c_expr
1549 default_function_array_conversion (struct c_expr exp)
1550 {
1551 tree orig_exp = exp.value;
1552 tree type = TREE_TYPE (exp.value);
1553 enum tree_code code = TREE_CODE (type);
1554
1555 switch (code)
1556 {
1557 case ARRAY_TYPE:
1558 {
1559 bool not_lvalue = false;
1560 bool lvalue_array_p;
1561
1562 while ((TREE_CODE (exp.value) == NON_LVALUE_EXPR
1563 || TREE_CODE (exp.value) == NOP_EXPR
1564 || TREE_CODE (exp.value) == CONVERT_EXPR)
1565 && TREE_TYPE (TREE_OPERAND (exp.value, 0)) == type)
1566 {
1567 if (TREE_CODE (exp.value) == NON_LVALUE_EXPR)
1568 not_lvalue = true;
1569 exp.value = TREE_OPERAND (exp.value, 0);
1570 }
1571
1572 if (TREE_NO_WARNING (orig_exp))
1573 TREE_NO_WARNING (exp.value) = 1;
1574
1575 lvalue_array_p = !not_lvalue && lvalue_p (exp.value);
1576 if (!flag_isoc99 && !lvalue_array_p)
1577 {
1578 /* Before C99, non-lvalue arrays do not decay to pointers.
1579 Normally, using such an array would be invalid; but it can
1580 be used correctly inside sizeof or as a statement expression.
1581 Thus, do not give an error here; an error will result later. */
1582 return exp;
1583 }
1584
1585 exp.value = array_to_pointer_conversion (exp.value);
1586 }
1587 break;
1588 case FUNCTION_TYPE:
1589 exp.value = function_to_pointer_conversion (exp.value);
1590 break;
1591 default:
1592 STRIP_TYPE_NOPS (exp.value);
1593 if (TREE_NO_WARNING (orig_exp))
1594 TREE_NO_WARNING (exp.value) = 1;
1595 break;
1596 }
1597
1598 return exp;
1599 }
1600
1601
1602 /* EXP is an expression of integer type. Apply the integer promotions
1603 to it and return the promoted value. */
1604
1605 tree
1606 perform_integral_promotions (tree exp)
1607 {
1608 tree type = TREE_TYPE (exp);
1609 enum tree_code code = TREE_CODE (type);
1610
1611 gcc_assert (INTEGRAL_TYPE_P (type));
1612
1613 /* Normally convert enums to int,
1614 but convert wide enums to something wider. */
1615 if (code == ENUMERAL_TYPE)
1616 {
1617 type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
1618 TYPE_PRECISION (integer_type_node)),
1619 ((TYPE_PRECISION (type)
1620 >= TYPE_PRECISION (integer_type_node))
1621 && TYPE_UNSIGNED (type)));
1622
1623 return convert (type, exp);
1624 }
1625
1626 /* ??? This should no longer be needed now bit-fields have their
1627 proper types. */
1628 if (TREE_CODE (exp) == COMPONENT_REF
1629 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
1630 /* If it's thinner than an int, promote it like a
1631 c_promoting_integer_type_p, otherwise leave it alone. */
1632 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
1633 TYPE_PRECISION (integer_type_node)))
1634 return convert (integer_type_node, exp);
1635
1636 if (c_promoting_integer_type_p (type))
1637 {
1638 /* Preserve unsignedness if not really getting any wider. */
1639 if (TYPE_UNSIGNED (type)
1640 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
1641 return convert (unsigned_type_node, exp);
1642
1643 return convert (integer_type_node, exp);
1644 }
1645
1646 return exp;
1647 }
1648
1649
1650 /* Perform default promotions for C data used in expressions.
1651 Enumeral types or short or char are converted to int.
1652 In addition, manifest constants symbols are replaced by their values. */
1653
1654 tree
1655 default_conversion (tree exp)
1656 {
1657 tree orig_exp;
1658 tree type = TREE_TYPE (exp);
1659 enum tree_code code = TREE_CODE (type);
1660
1661 /* Functions and arrays have been converted during parsing. */
1662 gcc_assert (code != FUNCTION_TYPE);
1663 if (code == ARRAY_TYPE)
1664 return exp;
1665
1666 /* Constants can be used directly unless they're not loadable. */
1667 if (TREE_CODE (exp) == CONST_DECL)
1668 exp = DECL_INITIAL (exp);
1669
1670 /* Replace a nonvolatile const static variable with its value unless
1671 it is an array, in which case we must be sure that taking the
1672 address of the array produces consistent results. */
1673 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE)
1674 {
1675 exp = decl_constant_value_for_broken_optimization (exp);
1676 type = TREE_TYPE (exp);
1677 }
1678
1679 /* Strip no-op conversions. */
1680 orig_exp = exp;
1681 STRIP_TYPE_NOPS (exp);
1682
1683 if (TREE_NO_WARNING (orig_exp))
1684 TREE_NO_WARNING (exp) = 1;
1685
1686 if (INTEGRAL_TYPE_P (type))
1687 return perform_integral_promotions (exp);
1688
1689 if (code == VOID_TYPE)
1690 {
1691 error ("void value not ignored as it ought to be");
1692 return error_mark_node;
1693 }
1694 return exp;
1695 }
1696 \f
1697 /* Look up COMPONENT in a structure or union DECL.
1698
1699 If the component name is not found, returns NULL_TREE. Otherwise,
1700 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1701 stepping down the chain to the component, which is in the last
1702 TREE_VALUE of the list. Normally the list is of length one, but if
1703 the component is embedded within (nested) anonymous structures or
1704 unions, the list steps down the chain to the component. */
1705
1706 static tree
1707 lookup_field (tree decl, tree component)
1708 {
1709 tree type = TREE_TYPE (decl);
1710 tree field;
1711
1712 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1713 to the field elements. Use a binary search on this array to quickly
1714 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1715 will always be set for structures which have many elements. */
1716
1717 if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s)
1718 {
1719 int bot, top, half;
1720 tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0];
1721
1722 field = TYPE_FIELDS (type);
1723 bot = 0;
1724 top = TYPE_LANG_SPECIFIC (type)->s->len;
1725 while (top - bot > 1)
1726 {
1727 half = (top - bot + 1) >> 1;
1728 field = field_array[bot+half];
1729
1730 if (DECL_NAME (field) == NULL_TREE)
1731 {
1732 /* Step through all anon unions in linear fashion. */
1733 while (DECL_NAME (field_array[bot]) == NULL_TREE)
1734 {
1735 field = field_array[bot++];
1736 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1737 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1738 {
1739 tree anon = lookup_field (field, component);
1740
1741 if (anon)
1742 return tree_cons (NULL_TREE, field, anon);
1743 }
1744 }
1745
1746 /* Entire record is only anon unions. */
1747 if (bot > top)
1748 return NULL_TREE;
1749
1750 /* Restart the binary search, with new lower bound. */
1751 continue;
1752 }
1753
1754 if (DECL_NAME (field) == component)
1755 break;
1756 if (DECL_NAME (field) < component)
1757 bot += half;
1758 else
1759 top = bot + half;
1760 }
1761
1762 if (DECL_NAME (field_array[bot]) == component)
1763 field = field_array[bot];
1764 else if (DECL_NAME (field) != component)
1765 return NULL_TREE;
1766 }
1767 else
1768 {
1769 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1770 {
1771 if (DECL_NAME (field) == NULL_TREE
1772 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1773 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
1774 {
1775 tree anon = lookup_field (field, component);
1776
1777 if (anon)
1778 return tree_cons (NULL_TREE, field, anon);
1779 }
1780
1781 if (DECL_NAME (field) == component)
1782 break;
1783 }
1784
1785 if (field == NULL_TREE)
1786 return NULL_TREE;
1787 }
1788
1789 return tree_cons (NULL_TREE, field, NULL_TREE);
1790 }
1791
1792 /* Make an expression to refer to the COMPONENT field of
1793 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1794
1795 tree
1796 build_component_ref (tree datum, tree component)
1797 {
1798 tree type = TREE_TYPE (datum);
1799 enum tree_code code = TREE_CODE (type);
1800 tree field = NULL;
1801 tree ref;
1802
1803 if (!objc_is_public (datum, component))
1804 return error_mark_node;
1805
1806 /* See if there is a field or component with name COMPONENT. */
1807
1808 if (code == RECORD_TYPE || code == UNION_TYPE)
1809 {
1810 if (!COMPLETE_TYPE_P (type))
1811 {
1812 c_incomplete_type_error (NULL_TREE, type);
1813 return error_mark_node;
1814 }
1815
1816 field = lookup_field (datum, component);
1817
1818 if (!field)
1819 {
1820 error ("%qT has no member named %qE", type, component);
1821 return error_mark_node;
1822 }
1823
1824 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1825 This might be better solved in future the way the C++ front
1826 end does it - by giving the anonymous entities each a
1827 separate name and type, and then have build_component_ref
1828 recursively call itself. We can't do that here. */
1829 do
1830 {
1831 tree subdatum = TREE_VALUE (field);
1832 int quals;
1833 tree subtype;
1834
1835 if (TREE_TYPE (subdatum) == error_mark_node)
1836 return error_mark_node;
1837
1838 quals = TYPE_QUALS (strip_array_types (TREE_TYPE (subdatum)));
1839 quals |= TYPE_QUALS (TREE_TYPE (datum));
1840 subtype = c_build_qualified_type (TREE_TYPE (subdatum), quals);
1841
1842 ref = build3 (COMPONENT_REF, subtype, datum, subdatum,
1843 NULL_TREE);
1844 if (TREE_READONLY (datum) || TREE_READONLY (subdatum))
1845 TREE_READONLY (ref) = 1;
1846 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
1847 TREE_THIS_VOLATILE (ref) = 1;
1848
1849 if (TREE_DEPRECATED (subdatum))
1850 warn_deprecated_use (subdatum);
1851
1852 datum = ref;
1853
1854 field = TREE_CHAIN (field);
1855 }
1856 while (field);
1857
1858 return ref;
1859 }
1860 else if (code != ERROR_MARK)
1861 error ("request for member %qE in something not a structure or union",
1862 component);
1863
1864 return error_mark_node;
1865 }
1866 \f
1867 /* Given an expression PTR for a pointer, return an expression
1868 for the value pointed to.
1869 ERRORSTRING is the name of the operator to appear in error messages. */
1870
1871 tree
1872 build_indirect_ref (tree ptr, const char *errorstring)
1873 {
1874 tree pointer = default_conversion (ptr);
1875 tree type = TREE_TYPE (pointer);
1876
1877 if (TREE_CODE (type) == POINTER_TYPE)
1878 {
1879 if (TREE_CODE (pointer) == ADDR_EXPR
1880 && (TREE_TYPE (TREE_OPERAND (pointer, 0))
1881 == TREE_TYPE (type)))
1882 return TREE_OPERAND (pointer, 0);
1883 else
1884 {
1885 tree t = TREE_TYPE (type);
1886 tree ref;
1887
1888 ref = build1 (INDIRECT_REF, t, pointer);
1889
1890 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
1891 {
1892 error ("dereferencing pointer to incomplete type");
1893 return error_mark_node;
1894 }
1895 if (VOID_TYPE_P (t) && skip_evaluation == 0)
1896 warning (0, "dereferencing %<void *%> pointer");
1897
1898 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1899 so that we get the proper error message if the result is used
1900 to assign to. Also, &* is supposed to be a no-op.
1901 And ANSI C seems to specify that the type of the result
1902 should be the const type. */
1903 /* A de-reference of a pointer to const is not a const. It is valid
1904 to change it via some other pointer. */
1905 TREE_READONLY (ref) = TYPE_READONLY (t);
1906 TREE_SIDE_EFFECTS (ref)
1907 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
1908 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
1909 return ref;
1910 }
1911 }
1912 else if (TREE_CODE (pointer) != ERROR_MARK)
1913 error ("invalid type argument of %qs", errorstring);
1914 return error_mark_node;
1915 }
1916
1917 /* This handles expressions of the form "a[i]", which denotes
1918 an array reference.
1919
1920 This is logically equivalent in C to *(a+i), but we may do it differently.
1921 If A is a variable or a member, we generate a primitive ARRAY_REF.
1922 This avoids forcing the array out of registers, and can work on
1923 arrays that are not lvalues (for example, members of structures returned
1924 by functions). */
1925
1926 tree
1927 build_array_ref (tree array, tree index)
1928 {
1929 bool swapped = false;
1930 if (TREE_TYPE (array) == error_mark_node
1931 || TREE_TYPE (index) == error_mark_node)
1932 return error_mark_node;
1933
1934 if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE
1935 && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE)
1936 {
1937 tree temp;
1938 if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE
1939 && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE)
1940 {
1941 error ("subscripted value is neither array nor pointer");
1942 return error_mark_node;
1943 }
1944 temp = array;
1945 array = index;
1946 index = temp;
1947 swapped = true;
1948 }
1949
1950 if (!INTEGRAL_TYPE_P (TREE_TYPE (index)))
1951 {
1952 error ("array subscript is not an integer");
1953 return error_mark_node;
1954 }
1955
1956 if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE)
1957 {
1958 error ("subscripted value is pointer to function");
1959 return error_mark_node;
1960 }
1961
1962 /* ??? Existing practice has been to warn only when the char
1963 index is syntactically the index, not for char[array]. */
1964 if (!swapped)
1965 warn_array_subscript_with_type_char (index);
1966
1967 /* Apply default promotions *after* noticing character types. */
1968 index = default_conversion (index);
1969
1970 gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
1971
1972 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
1973 {
1974 tree rval, type;
1975
1976 /* An array that is indexed by a non-constant
1977 cannot be stored in a register; we must be able to do
1978 address arithmetic on its address.
1979 Likewise an array of elements of variable size. */
1980 if (TREE_CODE (index) != INTEGER_CST
1981 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
1982 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
1983 {
1984 if (!c_mark_addressable (array))
1985 return error_mark_node;
1986 }
1987 /* An array that is indexed by a constant value which is not within
1988 the array bounds cannot be stored in a register either; because we
1989 would get a crash in store_bit_field/extract_bit_field when trying
1990 to access a non-existent part of the register. */
1991 if (TREE_CODE (index) == INTEGER_CST
1992 && TYPE_DOMAIN (TREE_TYPE (array))
1993 && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array))))
1994 {
1995 if (!c_mark_addressable (array))
1996 return error_mark_node;
1997 }
1998
1999 if (pedantic)
2000 {
2001 tree foo = array;
2002 while (TREE_CODE (foo) == COMPONENT_REF)
2003 foo = TREE_OPERAND (foo, 0);
2004 if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
2005 pedwarn ("ISO C forbids subscripting %<register%> array");
2006 else if (!flag_isoc99 && !lvalue_p (foo))
2007 pedwarn ("ISO C90 forbids subscripting non-lvalue array");
2008 }
2009
2010 type = TREE_TYPE (TREE_TYPE (array));
2011 if (TREE_CODE (type) != ARRAY_TYPE)
2012 type = TYPE_MAIN_VARIANT (type);
2013 rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE);
2014 /* Array ref is const/volatile if the array elements are
2015 or if the array is. */
2016 TREE_READONLY (rval)
2017 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
2018 | TREE_READONLY (array));
2019 TREE_SIDE_EFFECTS (rval)
2020 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2021 | TREE_SIDE_EFFECTS (array));
2022 TREE_THIS_VOLATILE (rval)
2023 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2024 /* This was added by rms on 16 Nov 91.
2025 It fixes vol struct foo *a; a->elts[1]
2026 in an inline function.
2027 Hope it doesn't break something else. */
2028 | TREE_THIS_VOLATILE (array));
2029 return require_complete_type (fold (rval));
2030 }
2031 else
2032 {
2033 tree ar = default_conversion (array);
2034
2035 if (ar == error_mark_node)
2036 return ar;
2037
2038 gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE);
2039 gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE);
2040
2041 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0),
2042 "array indexing");
2043 }
2044 }
2045 \f
2046 /* Build an external reference to identifier ID. FUN indicates
2047 whether this will be used for a function call. LOC is the source
2048 location of the identifier. */
2049 tree
2050 build_external_ref (tree id, int fun, location_t loc)
2051 {
2052 tree ref;
2053 tree decl = lookup_name (id);
2054
2055 /* In Objective-C, an instance variable (ivar) may be preferred to
2056 whatever lookup_name() found. */
2057 decl = objc_lookup_ivar (decl, id);
2058
2059 if (decl && decl != error_mark_node)
2060 ref = decl;
2061 else if (fun)
2062 /* Implicit function declaration. */
2063 ref = implicitly_declare (id);
2064 else if (decl == error_mark_node)
2065 /* Don't complain about something that's already been
2066 complained about. */
2067 return error_mark_node;
2068 else
2069 {
2070 undeclared_variable (id, loc);
2071 return error_mark_node;
2072 }
2073
2074 if (TREE_TYPE (ref) == error_mark_node)
2075 return error_mark_node;
2076
2077 if (TREE_DEPRECATED (ref))
2078 warn_deprecated_use (ref);
2079
2080 if (!skip_evaluation)
2081 assemble_external (ref);
2082 TREE_USED (ref) = 1;
2083
2084 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof)
2085 {
2086 if (!in_sizeof && !in_typeof)
2087 C_DECL_USED (ref) = 1;
2088 else if (DECL_INITIAL (ref) == 0
2089 && DECL_EXTERNAL (ref)
2090 && !TREE_PUBLIC (ref))
2091 record_maybe_used_decl (ref);
2092 }
2093
2094 if (TREE_CODE (ref) == CONST_DECL)
2095 {
2096 used_types_insert (TREE_TYPE (ref));
2097 ref = DECL_INITIAL (ref);
2098 TREE_CONSTANT (ref) = 1;
2099 TREE_INVARIANT (ref) = 1;
2100 }
2101 else if (current_function_decl != 0
2102 && !DECL_FILE_SCOPE_P (current_function_decl)
2103 && (TREE_CODE (ref) == VAR_DECL
2104 || TREE_CODE (ref) == PARM_DECL
2105 || TREE_CODE (ref) == FUNCTION_DECL))
2106 {
2107 tree context = decl_function_context (ref);
2108
2109 if (context != 0 && context != current_function_decl)
2110 DECL_NONLOCAL (ref) = 1;
2111 }
2112 /* C99 6.7.4p3: An inline definition of a function with external
2113 linkage ... shall not contain a reference to an identifier with
2114 internal linkage. */
2115 else if (current_function_decl != 0
2116 && DECL_DECLARED_INLINE_P (current_function_decl)
2117 && DECL_EXTERNAL (current_function_decl)
2118 && VAR_OR_FUNCTION_DECL_P (ref)
2119 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref))
2120 && ! TREE_PUBLIC (ref))
2121 pedwarn ("%H%qD is static but used in inline function %qD "
2122 "which is not static", &loc, ref, current_function_decl);
2123
2124 return ref;
2125 }
2126
2127 /* Record details of decls possibly used inside sizeof or typeof. */
2128 struct maybe_used_decl
2129 {
2130 /* The decl. */
2131 tree decl;
2132 /* The level seen at (in_sizeof + in_typeof). */
2133 int level;
2134 /* The next one at this level or above, or NULL. */
2135 struct maybe_used_decl *next;
2136 };
2137
2138 static struct maybe_used_decl *maybe_used_decls;
2139
2140 /* Record that DECL, an undefined static function reference seen
2141 inside sizeof or typeof, might be used if the operand of sizeof is
2142 a VLA type or the operand of typeof is a variably modified
2143 type. */
2144
2145 static void
2146 record_maybe_used_decl (tree decl)
2147 {
2148 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2149 t->decl = decl;
2150 t->level = in_sizeof + in_typeof;
2151 t->next = maybe_used_decls;
2152 maybe_used_decls = t;
2153 }
2154
2155 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2156 USED is false, just discard them. If it is true, mark them used
2157 (if no longer inside sizeof or typeof) or move them to the next
2158 level up (if still inside sizeof or typeof). */
2159
2160 void
2161 pop_maybe_used (bool used)
2162 {
2163 struct maybe_used_decl *p = maybe_used_decls;
2164 int cur_level = in_sizeof + in_typeof;
2165 while (p && p->level > cur_level)
2166 {
2167 if (used)
2168 {
2169 if (cur_level == 0)
2170 C_DECL_USED (p->decl) = 1;
2171 else
2172 p->level = cur_level;
2173 }
2174 p = p->next;
2175 }
2176 if (!used || cur_level == 0)
2177 maybe_used_decls = p;
2178 }
2179
2180 /* Return the result of sizeof applied to EXPR. */
2181
2182 struct c_expr
2183 c_expr_sizeof_expr (struct c_expr expr)
2184 {
2185 struct c_expr ret;
2186 if (expr.value == error_mark_node)
2187 {
2188 ret.value = error_mark_node;
2189 ret.original_code = ERROR_MARK;
2190 pop_maybe_used (false);
2191 }
2192 else
2193 {
2194 ret.value = c_sizeof (TREE_TYPE (expr.value));
2195 ret.original_code = ERROR_MARK;
2196 if (c_vla_type_p (TREE_TYPE (expr.value)))
2197 {
2198 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2199 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2200 }
2201 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2202 }
2203 return ret;
2204 }
2205
2206 /* Return the result of sizeof applied to T, a structure for the type
2207 name passed to sizeof (rather than the type itself). */
2208
2209 struct c_expr
2210 c_expr_sizeof_type (struct c_type_name *t)
2211 {
2212 tree type;
2213 struct c_expr ret;
2214 type = groktypename (t);
2215 ret.value = c_sizeof (type);
2216 ret.original_code = ERROR_MARK;
2217 pop_maybe_used (type != error_mark_node
2218 ? C_TYPE_VARIABLE_SIZE (type) : false);
2219 return ret;
2220 }
2221
2222 /* Build a function call to function FUNCTION with parameters PARAMS.
2223 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2224 TREE_VALUE of each node is a parameter-expression.
2225 FUNCTION's data type may be a function type or a pointer-to-function. */
2226
2227 tree
2228 build_function_call (tree function, tree params)
2229 {
2230 tree fntype, fundecl = 0;
2231 tree coerced_params;
2232 tree name = NULL_TREE, result;
2233 tree tem;
2234
2235 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2236 STRIP_TYPE_NOPS (function);
2237
2238 /* Convert anything with function type to a pointer-to-function. */
2239 if (TREE_CODE (function) == FUNCTION_DECL)
2240 {
2241 /* Implement type-directed function overloading for builtins.
2242 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2243 handle all the type checking. The result is a complete expression
2244 that implements this function call. */
2245 tem = resolve_overloaded_builtin (function, params);
2246 if (tem)
2247 return tem;
2248
2249 name = DECL_NAME (function);
2250 fundecl = function;
2251 }
2252 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2253 function = function_to_pointer_conversion (function);
2254
2255 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2256 expressions, like those used for ObjC messenger dispatches. */
2257 function = objc_rewrite_function_call (function, params);
2258
2259 fntype = TREE_TYPE (function);
2260
2261 if (TREE_CODE (fntype) == ERROR_MARK)
2262 return error_mark_node;
2263
2264 if (!(TREE_CODE (fntype) == POINTER_TYPE
2265 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2266 {
2267 error ("called object %qE is not a function", function);
2268 return error_mark_node;
2269 }
2270
2271 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2272 current_function_returns_abnormally = 1;
2273
2274 /* fntype now gets the type of function pointed to. */
2275 fntype = TREE_TYPE (fntype);
2276
2277 /* Check that the function is called through a compatible prototype.
2278 If it is not, replace the call by a trap, wrapped up in a compound
2279 expression if necessary. This has the nice side-effect to prevent
2280 the tree-inliner from generating invalid assignment trees which may
2281 blow up in the RTL expander later. */
2282 if ((TREE_CODE (function) == NOP_EXPR
2283 || TREE_CODE (function) == CONVERT_EXPR)
2284 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2285 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2286 && !comptypes (fntype, TREE_TYPE (tem)))
2287 {
2288 tree return_type = TREE_TYPE (fntype);
2289 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2290 NULL_TREE);
2291
2292 /* This situation leads to run-time undefined behavior. We can't,
2293 therefore, simply error unless we can prove that all possible
2294 executions of the program must execute the code. */
2295 warning (0, "function called through a non-compatible type");
2296
2297 /* We can, however, treat "undefined" any way we please.
2298 Call abort to encourage the user to fix the program. */
2299 inform ("if this code is reached, the program will abort");
2300
2301 if (VOID_TYPE_P (return_type))
2302 return trap;
2303 else
2304 {
2305 tree rhs;
2306
2307 if (AGGREGATE_TYPE_P (return_type))
2308 rhs = build_compound_literal (return_type,
2309 build_constructor (return_type, 0));
2310 else
2311 rhs = fold_convert (return_type, integer_zero_node);
2312
2313 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2314 }
2315 }
2316
2317 /* Convert the parameters to the types declared in the
2318 function prototype, or apply default promotions. */
2319
2320 coerced_params
2321 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl);
2322
2323 if (coerced_params == error_mark_node)
2324 return error_mark_node;
2325
2326 /* Check that the arguments to the function are valid. */
2327
2328 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2329 TYPE_ARG_TYPES (fntype));
2330
2331 if (require_constant_value)
2332 {
2333 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype),
2334 function, coerced_params, NULL_TREE);
2335
2336 if (TREE_CONSTANT (result)
2337 && (name == NULL_TREE
2338 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2339 pedwarn_init ("initializer element is not constant");
2340 }
2341 else
2342 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype),
2343 function, coerced_params, NULL_TREE);
2344
2345 if (VOID_TYPE_P (TREE_TYPE (result)))
2346 return result;
2347 return require_complete_type (result);
2348 }
2349 \f
2350 /* Convert the argument expressions in the list VALUES
2351 to the types in the list TYPELIST. The result is a list of converted
2352 argument expressions, unless there are too few arguments in which
2353 case it is error_mark_node.
2354
2355 If TYPELIST is exhausted, or when an element has NULL as its type,
2356 perform the default conversions.
2357
2358 PARMLIST is the chain of parm decls for the function being called.
2359 It may be 0, if that info is not available.
2360 It is used only for generating error messages.
2361
2362 FUNCTION is a tree for the called function. It is used only for
2363 error messages, where it is formatted with %qE.
2364
2365 This is also where warnings about wrong number of args are generated.
2366
2367 Both VALUES and the returned value are chains of TREE_LIST nodes
2368 with the elements of the list in the TREE_VALUE slots of those nodes. */
2369
2370 static tree
2371 convert_arguments (tree typelist, tree values, tree function, tree fundecl)
2372 {
2373 tree typetail, valtail;
2374 tree result = NULL;
2375 int parmnum;
2376 tree selector;
2377
2378 /* Change pointer to function to the function itself for
2379 diagnostics. */
2380 if (TREE_CODE (function) == ADDR_EXPR
2381 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2382 function = TREE_OPERAND (function, 0);
2383
2384 /* Handle an ObjC selector specially for diagnostics. */
2385 selector = objc_message_selector ();
2386
2387 /* Scan the given expressions and types, producing individual
2388 converted arguments and pushing them on RESULT in reverse order. */
2389
2390 for (valtail = values, typetail = typelist, parmnum = 0;
2391 valtail;
2392 valtail = TREE_CHAIN (valtail), parmnum++)
2393 {
2394 tree type = typetail ? TREE_VALUE (typetail) : 0;
2395 tree val = TREE_VALUE (valtail);
2396 tree rname = function;
2397 int argnum = parmnum + 1;
2398 const char *invalid_func_diag;
2399
2400 if (type == void_type_node)
2401 {
2402 error ("too many arguments to function %qE", function);
2403 break;
2404 }
2405
2406 if (selector && argnum > 2)
2407 {
2408 rname = selector;
2409 argnum -= 2;
2410 }
2411
2412 STRIP_TYPE_NOPS (val);
2413
2414 val = require_complete_type (val);
2415
2416 if (type != 0)
2417 {
2418 /* Formal parm type is specified by a function prototype. */
2419 tree parmval;
2420
2421 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2422 {
2423 error ("type of formal parameter %d is incomplete", parmnum + 1);
2424 parmval = val;
2425 }
2426 else
2427 {
2428 /* Optionally warn about conversions that
2429 differ from the default conversions. */
2430 if (warn_traditional_conversion || warn_traditional)
2431 {
2432 unsigned int formal_prec = TYPE_PRECISION (type);
2433
2434 if (INTEGRAL_TYPE_P (type)
2435 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2436 warning (0, "passing argument %d of %qE as integer "
2437 "rather than floating due to prototype",
2438 argnum, rname);
2439 if (INTEGRAL_TYPE_P (type)
2440 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2441 warning (0, "passing argument %d of %qE as integer "
2442 "rather than complex due to prototype",
2443 argnum, rname);
2444 else if (TREE_CODE (type) == COMPLEX_TYPE
2445 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2446 warning (0, "passing argument %d of %qE as complex "
2447 "rather than floating due to prototype",
2448 argnum, rname);
2449 else if (TREE_CODE (type) == REAL_TYPE
2450 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2451 warning (0, "passing argument %d of %qE as floating "
2452 "rather than integer due to prototype",
2453 argnum, rname);
2454 else if (TREE_CODE (type) == COMPLEX_TYPE
2455 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2456 warning (0, "passing argument %d of %qE as complex "
2457 "rather than integer due to prototype",
2458 argnum, rname);
2459 else if (TREE_CODE (type) == REAL_TYPE
2460 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2461 warning (0, "passing argument %d of %qE as floating "
2462 "rather than complex due to prototype",
2463 argnum, rname);
2464 /* ??? At some point, messages should be written about
2465 conversions between complex types, but that's too messy
2466 to do now. */
2467 else if (TREE_CODE (type) == REAL_TYPE
2468 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2469 {
2470 /* Warn if any argument is passed as `float',
2471 since without a prototype it would be `double'. */
2472 if (formal_prec == TYPE_PRECISION (float_type_node)
2473 && type != dfloat32_type_node)
2474 warning (0, "passing argument %d of %qE as %<float%> "
2475 "rather than %<double%> due to prototype",
2476 argnum, rname);
2477
2478 /* Warn if mismatch between argument and prototype
2479 for decimal float types. Warn of conversions with
2480 binary float types and of precision narrowing due to
2481 prototype. */
2482 else if (type != TREE_TYPE (val)
2483 && (type == dfloat32_type_node
2484 || type == dfloat64_type_node
2485 || type == dfloat128_type_node
2486 || TREE_TYPE (val) == dfloat32_type_node
2487 || TREE_TYPE (val) == dfloat64_type_node
2488 || TREE_TYPE (val) == dfloat128_type_node)
2489 && (formal_prec
2490 <= TYPE_PRECISION (TREE_TYPE (val))
2491 || (type == dfloat128_type_node
2492 && (TREE_TYPE (val)
2493 != dfloat64_type_node
2494 && (TREE_TYPE (val)
2495 != dfloat32_type_node)))
2496 || (type == dfloat64_type_node
2497 && (TREE_TYPE (val)
2498 != dfloat32_type_node))))
2499 warning (0, "passing argument %d of %qE as %qT "
2500 "rather than %qT due to prototype",
2501 argnum, rname, type, TREE_TYPE (val));
2502
2503 }
2504 /* Detect integer changing in width or signedness.
2505 These warnings are only activated with
2506 -Wtraditional-conversion, not with -Wtraditional. */
2507 else if (warn_traditional_conversion && INTEGRAL_TYPE_P (type)
2508 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2509 {
2510 tree would_have_been = default_conversion (val);
2511 tree type1 = TREE_TYPE (would_have_been);
2512
2513 if (TREE_CODE (type) == ENUMERAL_TYPE
2514 && (TYPE_MAIN_VARIANT (type)
2515 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2516 /* No warning if function asks for enum
2517 and the actual arg is that enum type. */
2518 ;
2519 else if (formal_prec != TYPE_PRECISION (type1))
2520 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2521 "with different width due to prototype",
2522 argnum, rname);
2523 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2524 ;
2525 /* Don't complain if the formal parameter type
2526 is an enum, because we can't tell now whether
2527 the value was an enum--even the same enum. */
2528 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2529 ;
2530 else if (TREE_CODE (val) == INTEGER_CST
2531 && int_fits_type_p (val, type))
2532 /* Change in signedness doesn't matter
2533 if a constant value is unaffected. */
2534 ;
2535 /* If the value is extended from a narrower
2536 unsigned type, it doesn't matter whether we
2537 pass it as signed or unsigned; the value
2538 certainly is the same either way. */
2539 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2540 && TYPE_UNSIGNED (TREE_TYPE (val)))
2541 ;
2542 else if (TYPE_UNSIGNED (type))
2543 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2544 "as unsigned due to prototype",
2545 argnum, rname);
2546 else
2547 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2548 "as signed due to prototype", argnum, rname);
2549 }
2550 }
2551
2552 parmval = convert_for_assignment (type, val, ic_argpass,
2553 fundecl, function,
2554 parmnum + 1);
2555
2556 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2557 && INTEGRAL_TYPE_P (type)
2558 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2559 parmval = default_conversion (parmval);
2560 }
2561 result = tree_cons (NULL_TREE, parmval, result);
2562 }
2563 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2564 && (TYPE_PRECISION (TREE_TYPE (val))
2565 < TYPE_PRECISION (double_type_node))
2566 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2567 /* Convert `float' to `double'. */
2568 result = tree_cons (NULL_TREE, convert (double_type_node, val), result);
2569 else if ((invalid_func_diag =
2570 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2571 {
2572 error (invalid_func_diag);
2573 return error_mark_node;
2574 }
2575 else
2576 /* Convert `short' and `char' to full-size `int'. */
2577 result = tree_cons (NULL_TREE, default_conversion (val), result);
2578
2579 if (typetail)
2580 typetail = TREE_CHAIN (typetail);
2581 }
2582
2583 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2584 {
2585 error ("too few arguments to function %qE", function);
2586 return error_mark_node;
2587 }
2588
2589 return nreverse (result);
2590 }
2591 \f
2592 /* This is the entry point used by the parser to build unary operators
2593 in the input. CODE, a tree_code, specifies the unary operator, and
2594 ARG is the operand. For unary plus, the C parser currently uses
2595 CONVERT_EXPR for code. */
2596
2597 struct c_expr
2598 parser_build_unary_op (enum tree_code code, struct c_expr arg)
2599 {
2600 struct c_expr result;
2601
2602 result.original_code = ERROR_MARK;
2603 result.value = build_unary_op (code, arg.value, 0);
2604
2605 if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value))
2606 overflow_warning (result.value);
2607
2608 return result;
2609 }
2610
2611 /* This is the entry point used by the parser to build binary operators
2612 in the input. CODE, a tree_code, specifies the binary operator, and
2613 ARG1 and ARG2 are the operands. In addition to constructing the
2614 expression, we check for operands that were written with other binary
2615 operators in a way that is likely to confuse the user. */
2616
2617 struct c_expr
2618 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2619 struct c_expr arg2)
2620 {
2621 struct c_expr result;
2622
2623 enum tree_code code1 = arg1.original_code;
2624 enum tree_code code2 = arg2.original_code;
2625
2626 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2627 result.original_code = code;
2628
2629 if (TREE_CODE (result.value) == ERROR_MARK)
2630 return result;
2631
2632 /* Check for cases such as x+y<<z which users are likely
2633 to misinterpret. */
2634 if (warn_parentheses)
2635 warn_about_parentheses (code, code1, code2);
2636
2637 /* Warn about comparisons against string literals, with the exception
2638 of testing for equality or inequality of a string literal with NULL. */
2639 if (code == EQ_EXPR || code == NE_EXPR)
2640 {
2641 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2642 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2643 warning (OPT_Wstring_literal_comparison,
2644 "comparison with string literal");
2645 }
2646 else if (TREE_CODE_CLASS (code) == tcc_comparison
2647 && (code1 == STRING_CST || code2 == STRING_CST))
2648 warning (OPT_Wstring_literal_comparison,
2649 "comparison with string literal");
2650
2651 if (TREE_OVERFLOW_P (result.value)
2652 && !TREE_OVERFLOW_P (arg1.value)
2653 && !TREE_OVERFLOW_P (arg2.value))
2654 overflow_warning (result.value);
2655
2656 return result;
2657 }
2658 \f
2659 /* Return a tree for the difference of pointers OP0 and OP1.
2660 The resulting tree has type int. */
2661
2662 static tree
2663 pointer_diff (tree op0, tree op1)
2664 {
2665 tree restype = ptrdiff_type_node;
2666
2667 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2668 tree con0, con1, lit0, lit1;
2669 tree orig_op1 = op1;
2670
2671 if (pedantic || warn_pointer_arith)
2672 {
2673 if (TREE_CODE (target_type) == VOID_TYPE)
2674 pedwarn ("pointer of type %<void *%> used in subtraction");
2675 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2676 pedwarn ("pointer to a function used in subtraction");
2677 }
2678
2679 /* If the conversion to ptrdiff_type does anything like widening or
2680 converting a partial to an integral mode, we get a convert_expression
2681 that is in the way to do any simplifications.
2682 (fold-const.c doesn't know that the extra bits won't be needed.
2683 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2684 different mode in place.)
2685 So first try to find a common term here 'by hand'; we want to cover
2686 at least the cases that occur in legal static initializers. */
2687 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR)
2688 && (TYPE_PRECISION (TREE_TYPE (op0))
2689 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2690 con0 = TREE_OPERAND (op0, 0);
2691 else
2692 con0 = op0;
2693 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR)
2694 && (TYPE_PRECISION (TREE_TYPE (op1))
2695 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2696 con1 = TREE_OPERAND (op1, 0);
2697 else
2698 con1 = op1;
2699
2700 if (TREE_CODE (con0) == PLUS_EXPR)
2701 {
2702 lit0 = TREE_OPERAND (con0, 1);
2703 con0 = TREE_OPERAND (con0, 0);
2704 }
2705 else
2706 lit0 = integer_zero_node;
2707
2708 if (TREE_CODE (con1) == PLUS_EXPR)
2709 {
2710 lit1 = TREE_OPERAND (con1, 1);
2711 con1 = TREE_OPERAND (con1, 0);
2712 }
2713 else
2714 lit1 = integer_zero_node;
2715
2716 if (operand_equal_p (con0, con1, 0))
2717 {
2718 op0 = lit0;
2719 op1 = lit1;
2720 }
2721
2722
2723 /* First do the subtraction as integers;
2724 then drop through to build the divide operator.
2725 Do not do default conversions on the minus operator
2726 in case restype is a short type. */
2727
2728 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2729 convert (restype, op1), 0);
2730 /* This generates an error if op1 is pointer to incomplete type. */
2731 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2732 error ("arithmetic on pointer to an incomplete type");
2733
2734 /* This generates an error if op0 is pointer to incomplete type. */
2735 op1 = c_size_in_bytes (target_type);
2736
2737 /* Divide by the size, in easiest possible way. */
2738 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2739 }
2740 \f
2741 /* Construct and perhaps optimize a tree representation
2742 for a unary operation. CODE, a tree_code, specifies the operation
2743 and XARG is the operand.
2744 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2745 the default promotions (such as from short to int).
2746 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2747 allows non-lvalues; this is only used to handle conversion of non-lvalue
2748 arrays to pointers in C99. */
2749
2750 tree
2751 build_unary_op (enum tree_code code, tree xarg, int flag)
2752 {
2753 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2754 tree arg = xarg;
2755 tree argtype = 0;
2756 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2757 tree val;
2758 int noconvert = flag;
2759 const char *invalid_op_diag;
2760
2761 if (typecode == ERROR_MARK)
2762 return error_mark_node;
2763 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2764 typecode = INTEGER_TYPE;
2765
2766 if ((invalid_op_diag
2767 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2768 {
2769 error (invalid_op_diag);
2770 return error_mark_node;
2771 }
2772
2773 switch (code)
2774 {
2775 case CONVERT_EXPR:
2776 /* This is used for unary plus, because a CONVERT_EXPR
2777 is enough to prevent anybody from looking inside for
2778 associativity, but won't generate any code. */
2779 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2780 || typecode == COMPLEX_TYPE
2781 || typecode == VECTOR_TYPE))
2782 {
2783 error ("wrong type argument to unary plus");
2784 return error_mark_node;
2785 }
2786 else if (!noconvert)
2787 arg = default_conversion (arg);
2788 arg = non_lvalue (arg);
2789 break;
2790
2791 case NEGATE_EXPR:
2792 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2793 || typecode == COMPLEX_TYPE
2794 || typecode == VECTOR_TYPE))
2795 {
2796 error ("wrong type argument to unary minus");
2797 return error_mark_node;
2798 }
2799 else if (!noconvert)
2800 arg = default_conversion (arg);
2801 break;
2802
2803 case BIT_NOT_EXPR:
2804 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE)
2805 {
2806 if (!noconvert)
2807 arg = default_conversion (arg);
2808 }
2809 else if (typecode == COMPLEX_TYPE)
2810 {
2811 code = CONJ_EXPR;
2812 if (pedantic)
2813 pedwarn ("ISO C does not support %<~%> for complex conjugation");
2814 if (!noconvert)
2815 arg = default_conversion (arg);
2816 }
2817 else
2818 {
2819 error ("wrong type argument to bit-complement");
2820 return error_mark_node;
2821 }
2822 break;
2823
2824 case ABS_EXPR:
2825 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2826 {
2827 error ("wrong type argument to abs");
2828 return error_mark_node;
2829 }
2830 else if (!noconvert)
2831 arg = default_conversion (arg);
2832 break;
2833
2834 case CONJ_EXPR:
2835 /* Conjugating a real value is a no-op, but allow it anyway. */
2836 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2837 || typecode == COMPLEX_TYPE))
2838 {
2839 error ("wrong type argument to conjugation");
2840 return error_mark_node;
2841 }
2842 else if (!noconvert)
2843 arg = default_conversion (arg);
2844 break;
2845
2846 case TRUTH_NOT_EXPR:
2847 if (typecode != INTEGER_TYPE
2848 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2849 && typecode != COMPLEX_TYPE)
2850 {
2851 error ("wrong type argument to unary exclamation mark");
2852 return error_mark_node;
2853 }
2854 arg = c_objc_common_truthvalue_conversion (arg);
2855 return invert_truthvalue (arg);
2856
2857 case REALPART_EXPR:
2858 if (TREE_CODE (arg) == COMPLEX_CST)
2859 return TREE_REALPART (arg);
2860 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2861 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2862 else
2863 return arg;
2864
2865 case IMAGPART_EXPR:
2866 if (TREE_CODE (arg) == COMPLEX_CST)
2867 return TREE_IMAGPART (arg);
2868 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2869 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2870 else
2871 return convert (TREE_TYPE (arg), integer_zero_node);
2872
2873 case PREINCREMENT_EXPR:
2874 case POSTINCREMENT_EXPR:
2875 case PREDECREMENT_EXPR:
2876 case POSTDECREMENT_EXPR:
2877
2878 /* Increment or decrement the real part of the value,
2879 and don't change the imaginary part. */
2880 if (typecode == COMPLEX_TYPE)
2881 {
2882 tree real, imag;
2883
2884 if (pedantic)
2885 pedwarn ("ISO C does not support %<++%> and %<--%>"
2886 " on complex types");
2887
2888 arg = stabilize_reference (arg);
2889 real = build_unary_op (REALPART_EXPR, arg, 1);
2890 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2891 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
2892 build_unary_op (code, real, 1), imag);
2893 }
2894
2895 /* Report invalid types. */
2896
2897 if (typecode != POINTER_TYPE
2898 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2899 {
2900 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2901 error ("wrong type argument to increment");
2902 else
2903 error ("wrong type argument to decrement");
2904
2905 return error_mark_node;
2906 }
2907
2908 {
2909 tree inc;
2910 tree result_type = TREE_TYPE (arg);
2911
2912 arg = get_unwidened (arg, 0);
2913 argtype = TREE_TYPE (arg);
2914
2915 /* Compute the increment. */
2916
2917 if (typecode == POINTER_TYPE)
2918 {
2919 /* If pointer target is an undefined struct,
2920 we just cannot know how to do the arithmetic. */
2921 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2922 {
2923 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2924 error ("increment of pointer to unknown structure");
2925 else
2926 error ("decrement of pointer to unknown structure");
2927 }
2928 else if ((pedantic || warn_pointer_arith)
2929 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2930 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2931 {
2932 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2933 pedwarn ("wrong type argument to increment");
2934 else
2935 pedwarn ("wrong type argument to decrement");
2936 }
2937
2938 inc = c_size_in_bytes (TREE_TYPE (result_type));
2939 }
2940 else
2941 inc = integer_one_node;
2942
2943 inc = convert (argtype, inc);
2944
2945 /* Complain about anything else that is not a true lvalue. */
2946 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
2947 || code == POSTINCREMENT_EXPR)
2948 ? lv_increment
2949 : lv_decrement)))
2950 return error_mark_node;
2951
2952 /* Report a read-only lvalue. */
2953 if (TREE_READONLY (arg))
2954 {
2955 readonly_error (arg,
2956 ((code == PREINCREMENT_EXPR
2957 || code == POSTINCREMENT_EXPR)
2958 ? lv_increment : lv_decrement));
2959 return error_mark_node;
2960 }
2961
2962 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2963 val = boolean_increment (code, arg);
2964 else
2965 val = build2 (code, TREE_TYPE (arg), arg, inc);
2966 TREE_SIDE_EFFECTS (val) = 1;
2967 val = convert (result_type, val);
2968 if (TREE_CODE (val) != code)
2969 TREE_NO_WARNING (val) = 1;
2970 return val;
2971 }
2972
2973 case ADDR_EXPR:
2974 /* Note that this operation never does default_conversion. */
2975
2976 /* Let &* cancel out to simplify resulting code. */
2977 if (TREE_CODE (arg) == INDIRECT_REF)
2978 {
2979 /* Don't let this be an lvalue. */
2980 if (lvalue_p (TREE_OPERAND (arg, 0)))
2981 return non_lvalue (TREE_OPERAND (arg, 0));
2982 return TREE_OPERAND (arg, 0);
2983 }
2984
2985 /* For &x[y], return x+y */
2986 if (TREE_CODE (arg) == ARRAY_REF)
2987 {
2988 tree op0 = TREE_OPERAND (arg, 0);
2989 if (!c_mark_addressable (op0))
2990 return error_mark_node;
2991 return build_binary_op (PLUS_EXPR,
2992 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
2993 ? array_to_pointer_conversion (op0)
2994 : op0),
2995 TREE_OPERAND (arg, 1), 1);
2996 }
2997
2998 /* Anything not already handled and not a true memory reference
2999 or a non-lvalue array is an error. */
3000 else if (typecode != FUNCTION_TYPE && !flag
3001 && !lvalue_or_else (arg, lv_addressof))
3002 return error_mark_node;
3003
3004 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3005 argtype = TREE_TYPE (arg);
3006
3007 /* If the lvalue is const or volatile, merge that into the type
3008 to which the address will point. Note that you can't get a
3009 restricted pointer by taking the address of something, so we
3010 only have to deal with `const' and `volatile' here. */
3011 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3012 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3013 argtype = c_build_type_variant (argtype,
3014 TREE_READONLY (arg),
3015 TREE_THIS_VOLATILE (arg));
3016
3017 if (!c_mark_addressable (arg))
3018 return error_mark_node;
3019
3020 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3021 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3022
3023 argtype = build_pointer_type (argtype);
3024
3025 /* ??? Cope with user tricks that amount to offsetof. Delete this
3026 when we have proper support for integer constant expressions. */
3027 val = get_base_address (arg);
3028 if (val && TREE_CODE (val) == INDIRECT_REF
3029 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3030 {
3031 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1;
3032
3033 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3034 return fold_build2 (PLUS_EXPR, argtype, op0, op1);
3035 }
3036
3037 val = build1 (ADDR_EXPR, argtype, arg);
3038
3039 return val;
3040
3041 default:
3042 gcc_unreachable ();
3043 }
3044
3045 if (argtype == 0)
3046 argtype = TREE_TYPE (arg);
3047 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3048 : fold_build1 (code, argtype, arg);
3049 }
3050
3051 /* Return nonzero if REF is an lvalue valid for this language.
3052 Lvalues can be assigned, unless their type has TYPE_READONLY.
3053 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3054
3055 static int
3056 lvalue_p (tree ref)
3057 {
3058 enum tree_code code = TREE_CODE (ref);
3059
3060 switch (code)
3061 {
3062 case REALPART_EXPR:
3063 case IMAGPART_EXPR:
3064 case COMPONENT_REF:
3065 return lvalue_p (TREE_OPERAND (ref, 0));
3066
3067 case COMPOUND_LITERAL_EXPR:
3068 case STRING_CST:
3069 return 1;
3070
3071 case INDIRECT_REF:
3072 case ARRAY_REF:
3073 case VAR_DECL:
3074 case PARM_DECL:
3075 case RESULT_DECL:
3076 case ERROR_MARK:
3077 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3078 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3079
3080 case BIND_EXPR:
3081 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3082
3083 default:
3084 return 0;
3085 }
3086 }
3087 \f
3088 /* Give an error for storing in something that is 'const'. */
3089
3090 static void
3091 readonly_error (tree arg, enum lvalue_use use)
3092 {
3093 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3094 || use == lv_asm);
3095 /* Using this macro rather than (for example) arrays of messages
3096 ensures that all the format strings are checked at compile
3097 time. */
3098 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3099 : (use == lv_increment ? (I) \
3100 : (use == lv_decrement ? (D) : (AS))))
3101 if (TREE_CODE (arg) == COMPONENT_REF)
3102 {
3103 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3104 readonly_error (TREE_OPERAND (arg, 0), use);
3105 else
3106 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3107 G_("increment of read-only member %qD"),
3108 G_("decrement of read-only member %qD"),
3109 G_("read-only member %qD used as %<asm%> output")),
3110 TREE_OPERAND (arg, 1));
3111 }
3112 else if (TREE_CODE (arg) == VAR_DECL)
3113 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3114 G_("increment of read-only variable %qD"),
3115 G_("decrement of read-only variable %qD"),
3116 G_("read-only variable %qD used as %<asm%> output")),
3117 arg);
3118 else
3119 error (READONLY_MSG (G_("assignment of read-only location"),
3120 G_("increment of read-only location"),
3121 G_("decrement of read-only location"),
3122 G_("read-only location used as %<asm%> output")));
3123 }
3124
3125
3126 /* Return nonzero if REF is an lvalue valid for this language;
3127 otherwise, print an error message and return zero. USE says
3128 how the lvalue is being used and so selects the error message. */
3129
3130 static int
3131 lvalue_or_else (tree ref, enum lvalue_use use)
3132 {
3133 int win = lvalue_p (ref);
3134
3135 if (!win)
3136 lvalue_error (use);
3137
3138 return win;
3139 }
3140 \f
3141 /* Mark EXP saying that we need to be able to take the
3142 address of it; it should not be allocated in a register.
3143 Returns true if successful. */
3144
3145 bool
3146 c_mark_addressable (tree exp)
3147 {
3148 tree x = exp;
3149
3150 while (1)
3151 switch (TREE_CODE (x))
3152 {
3153 case COMPONENT_REF:
3154 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3155 {
3156 error
3157 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3158 return false;
3159 }
3160
3161 /* ... fall through ... */
3162
3163 case ADDR_EXPR:
3164 case ARRAY_REF:
3165 case REALPART_EXPR:
3166 case IMAGPART_EXPR:
3167 x = TREE_OPERAND (x, 0);
3168 break;
3169
3170 case COMPOUND_LITERAL_EXPR:
3171 case CONSTRUCTOR:
3172 TREE_ADDRESSABLE (x) = 1;
3173 return true;
3174
3175 case VAR_DECL:
3176 case CONST_DECL:
3177 case PARM_DECL:
3178 case RESULT_DECL:
3179 if (C_DECL_REGISTER (x)
3180 && DECL_NONLOCAL (x))
3181 {
3182 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3183 {
3184 error
3185 ("global register variable %qD used in nested function", x);
3186 return false;
3187 }
3188 pedwarn ("register variable %qD used in nested function", x);
3189 }
3190 else if (C_DECL_REGISTER (x))
3191 {
3192 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3193 error ("address of global register variable %qD requested", x);
3194 else
3195 error ("address of register variable %qD requested", x);
3196 return false;
3197 }
3198
3199 /* drops in */
3200 case FUNCTION_DECL:
3201 TREE_ADDRESSABLE (x) = 1;
3202 /* drops out */
3203 default:
3204 return true;
3205 }
3206 }
3207 \f
3208 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3209
3210 tree
3211 build_conditional_expr (tree ifexp, tree op1, tree op2)
3212 {
3213 tree type1;
3214 tree type2;
3215 enum tree_code code1;
3216 enum tree_code code2;
3217 tree result_type = NULL;
3218 tree orig_op1 = op1, orig_op2 = op2;
3219
3220 /* Promote both alternatives. */
3221
3222 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3223 op1 = default_conversion (op1);
3224 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3225 op2 = default_conversion (op2);
3226
3227 if (TREE_CODE (ifexp) == ERROR_MARK
3228 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3229 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3230 return error_mark_node;
3231
3232 type1 = TREE_TYPE (op1);
3233 code1 = TREE_CODE (type1);
3234 type2 = TREE_TYPE (op2);
3235 code2 = TREE_CODE (type2);
3236
3237 /* C90 does not permit non-lvalue arrays in conditional expressions.
3238 In C99 they will be pointers by now. */
3239 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3240 {
3241 error ("non-lvalue array in conditional expression");
3242 return error_mark_node;
3243 }
3244
3245 /* Quickly detect the usual case where op1 and op2 have the same type
3246 after promotion. */
3247 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3248 {
3249 if (type1 == type2)
3250 result_type = type1;
3251 else
3252 result_type = TYPE_MAIN_VARIANT (type1);
3253 }
3254 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3255 || code1 == COMPLEX_TYPE)
3256 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3257 || code2 == COMPLEX_TYPE))
3258 {
3259 result_type = c_common_type (type1, type2);
3260
3261 /* If -Wsign-compare, warn here if type1 and type2 have
3262 different signedness. We'll promote the signed to unsigned
3263 and later code won't know it used to be different.
3264 Do this check on the original types, so that explicit casts
3265 will be considered, but default promotions won't. */
3266 if (warn_sign_compare && !skip_evaluation)
3267 {
3268 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3269 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3270
3271 if (unsigned_op1 ^ unsigned_op2)
3272 {
3273 bool ovf;
3274
3275 /* Do not warn if the result type is signed, since the
3276 signed type will only be chosen if it can represent
3277 all the values of the unsigned type. */
3278 if (!TYPE_UNSIGNED (result_type))
3279 /* OK */;
3280 /* Do not warn if the signed quantity is an unsuffixed
3281 integer literal (or some static constant expression
3282 involving such literals) and it is non-negative. */
3283 else if ((unsigned_op2
3284 && tree_expr_nonnegative_warnv_p (op1, &ovf))
3285 || (unsigned_op1
3286 && tree_expr_nonnegative_warnv_p (op2, &ovf)))
3287 /* OK */;
3288 else
3289 warning (0, "signed and unsigned type in conditional expression");
3290 }
3291 }
3292 }
3293 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3294 {
3295 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3296 pedwarn ("ISO C forbids conditional expr with only one void side");
3297 result_type = void_type_node;
3298 }
3299 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3300 {
3301 if (comp_target_types (type1, type2))
3302 result_type = common_pointer_type (type1, type2);
3303 else if (null_pointer_constant_p (orig_op1))
3304 result_type = qualify_type (type2, type1);
3305 else if (null_pointer_constant_p (orig_op2))
3306 result_type = qualify_type (type1, type2);
3307 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3308 {
3309 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3310 pedwarn ("ISO C forbids conditional expr between "
3311 "%<void *%> and function pointer");
3312 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3313 TREE_TYPE (type2)));
3314 }
3315 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3316 {
3317 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3318 pedwarn ("ISO C forbids conditional expr between "
3319 "%<void *%> and function pointer");
3320 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3321 TREE_TYPE (type1)));
3322 }
3323 else
3324 {
3325 pedwarn ("pointer type mismatch in conditional expression");
3326 result_type = build_pointer_type (void_type_node);
3327 }
3328 }
3329 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3330 {
3331 if (!null_pointer_constant_p (orig_op2))
3332 pedwarn ("pointer/integer type mismatch in conditional expression");
3333 else
3334 {
3335 op2 = null_pointer_node;
3336 }
3337 result_type = type1;
3338 }
3339 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3340 {
3341 if (!null_pointer_constant_p (orig_op1))
3342 pedwarn ("pointer/integer type mismatch in conditional expression");
3343 else
3344 {
3345 op1 = null_pointer_node;
3346 }
3347 result_type = type2;
3348 }
3349
3350 if (!result_type)
3351 {
3352 if (flag_cond_mismatch)
3353 result_type = void_type_node;
3354 else
3355 {
3356 error ("type mismatch in conditional expression");
3357 return error_mark_node;
3358 }
3359 }
3360
3361 /* Merge const and volatile flags of the incoming types. */
3362 result_type
3363 = build_type_variant (result_type,
3364 TREE_READONLY (op1) || TREE_READONLY (op2),
3365 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3366
3367 if (result_type != TREE_TYPE (op1))
3368 op1 = convert_and_check (result_type, op1);
3369 if (result_type != TREE_TYPE (op2))
3370 op2 = convert_and_check (result_type, op2);
3371
3372 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3373 }
3374 \f
3375 /* Return a compound expression that performs two expressions and
3376 returns the value of the second of them. */
3377
3378 tree
3379 build_compound_expr (tree expr1, tree expr2)
3380 {
3381 if (!TREE_SIDE_EFFECTS (expr1))
3382 {
3383 /* The left-hand operand of a comma expression is like an expression
3384 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3385 any side-effects, unless it was explicitly cast to (void). */
3386 if (warn_unused_value)
3387 {
3388 if (VOID_TYPE_P (TREE_TYPE (expr1))
3389 && (TREE_CODE (expr1) == NOP_EXPR
3390 || TREE_CODE (expr1) == CONVERT_EXPR))
3391 ; /* (void) a, b */
3392 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3393 && TREE_CODE (expr1) == COMPOUND_EXPR
3394 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR
3395 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR))
3396 ; /* (void) a, (void) b, c */
3397 else
3398 warning (0, "left-hand operand of comma expression has no effect");
3399 }
3400 }
3401
3402 /* With -Wunused, we should also warn if the left-hand operand does have
3403 side-effects, but computes a value which is not used. For example, in
3404 `foo() + bar(), baz()' the result of the `+' operator is not used,
3405 so we should issue a warning. */
3406 else if (warn_unused_value)
3407 warn_if_unused_value (expr1, input_location);
3408
3409 if (expr2 == error_mark_node)
3410 return error_mark_node;
3411
3412 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3413 }
3414
3415 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3416
3417 tree
3418 build_c_cast (tree type, tree expr)
3419 {
3420 tree value = expr;
3421
3422 if (type == error_mark_node || expr == error_mark_node)
3423 return error_mark_node;
3424
3425 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3426 only in <protocol> qualifications. But when constructing cast expressions,
3427 the protocols do matter and must be kept around. */
3428 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3429 return build1 (NOP_EXPR, type, expr);
3430
3431 type = TYPE_MAIN_VARIANT (type);
3432
3433 if (TREE_CODE (type) == ARRAY_TYPE)
3434 {
3435 error ("cast specifies array type");
3436 return error_mark_node;
3437 }
3438
3439 if (TREE_CODE (type) == FUNCTION_TYPE)
3440 {
3441 error ("cast specifies function type");
3442 return error_mark_node;
3443 }
3444
3445 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3446 {
3447 if (pedantic)
3448 {
3449 if (TREE_CODE (type) == RECORD_TYPE
3450 || TREE_CODE (type) == UNION_TYPE)
3451 pedwarn ("ISO C forbids casting nonscalar to the same type");
3452 }
3453 }
3454 else if (TREE_CODE (type) == UNION_TYPE)
3455 {
3456 tree field;
3457
3458 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3459 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3460 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3461 break;
3462
3463 if (field)
3464 {
3465 tree t;
3466
3467 if (pedantic)
3468 pedwarn ("ISO C forbids casts to union type");
3469 t = digest_init (type,
3470 build_constructor_single (type, field, value),
3471 true, 0);
3472 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3473 TREE_INVARIANT (t) = TREE_INVARIANT (value);
3474 return t;
3475 }
3476 error ("cast to union type from type not present in union");
3477 return error_mark_node;
3478 }
3479 else
3480 {
3481 tree otype, ovalue;
3482
3483 if (type == void_type_node)
3484 return build1 (CONVERT_EXPR, type, value);
3485
3486 otype = TREE_TYPE (value);
3487
3488 /* Optionally warn about potentially worrisome casts. */
3489
3490 if (warn_cast_qual
3491 && TREE_CODE (type) == POINTER_TYPE
3492 && TREE_CODE (otype) == POINTER_TYPE)
3493 {
3494 tree in_type = type;
3495 tree in_otype = otype;
3496 int added = 0;
3497 int discarded = 0;
3498
3499 /* Check that the qualifiers on IN_TYPE are a superset of
3500 the qualifiers of IN_OTYPE. The outermost level of
3501 POINTER_TYPE nodes is uninteresting and we stop as soon
3502 as we hit a non-POINTER_TYPE node on either type. */
3503 do
3504 {
3505 in_otype = TREE_TYPE (in_otype);
3506 in_type = TREE_TYPE (in_type);
3507
3508 /* GNU C allows cv-qualified function types. 'const'
3509 means the function is very pure, 'volatile' means it
3510 can't return. We need to warn when such qualifiers
3511 are added, not when they're taken away. */
3512 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3513 && TREE_CODE (in_type) == FUNCTION_TYPE)
3514 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3515 else
3516 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3517 }
3518 while (TREE_CODE (in_type) == POINTER_TYPE
3519 && TREE_CODE (in_otype) == POINTER_TYPE);
3520
3521 if (added)
3522 warning (0, "cast adds new qualifiers to function type");
3523
3524 if (discarded)
3525 /* There are qualifiers present in IN_OTYPE that are not
3526 present in IN_TYPE. */
3527 warning (0, "cast discards qualifiers from pointer target type");
3528 }
3529
3530 /* Warn about possible alignment problems. */
3531 if (STRICT_ALIGNMENT
3532 && TREE_CODE (type) == POINTER_TYPE
3533 && TREE_CODE (otype) == POINTER_TYPE
3534 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3535 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3536 /* Don't warn about opaque types, where the actual alignment
3537 restriction is unknown. */
3538 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3539 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3540 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3541 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3542 warning (OPT_Wcast_align,
3543 "cast increases required alignment of target type");
3544
3545 if (TREE_CODE (type) == INTEGER_TYPE
3546 && TREE_CODE (otype) == POINTER_TYPE
3547 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3548 /* Unlike conversion of integers to pointers, where the
3549 warning is disabled for converting constants because
3550 of cases such as SIG_*, warn about converting constant
3551 pointers to integers. In some cases it may cause unwanted
3552 sign extension, and a warning is appropriate. */
3553 warning (OPT_Wpointer_to_int_cast,
3554 "cast from pointer to integer of different size");
3555
3556 if (TREE_CODE (value) == CALL_EXPR
3557 && TREE_CODE (type) != TREE_CODE (otype))
3558 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3559 "to non-matching type %qT", otype, type);
3560
3561 if (TREE_CODE (type) == POINTER_TYPE
3562 && TREE_CODE (otype) == INTEGER_TYPE
3563 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3564 /* Don't warn about converting any constant. */
3565 && !TREE_CONSTANT (value))
3566 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3567 "of different size");
3568
3569 strict_aliasing_warning (otype, type, expr);
3570
3571 /* If pedantic, warn for conversions between function and object
3572 pointer types, except for converting a null pointer constant
3573 to function pointer type. */
3574 if (pedantic
3575 && TREE_CODE (type) == POINTER_TYPE
3576 && TREE_CODE (otype) == POINTER_TYPE
3577 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3578 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3579 pedwarn ("ISO C forbids conversion of function pointer to object pointer type");
3580
3581 if (pedantic
3582 && TREE_CODE (type) == POINTER_TYPE
3583 && TREE_CODE (otype) == POINTER_TYPE
3584 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3585 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3586 && !null_pointer_constant_p (value))
3587 pedwarn ("ISO C forbids conversion of object pointer to function pointer type");
3588
3589 ovalue = value;
3590 value = convert (type, value);
3591
3592 /* Ignore any integer overflow caused by the cast. */
3593 if (TREE_CODE (value) == INTEGER_CST)
3594 {
3595 if (CONSTANT_CLASS_P (ovalue) && TREE_OVERFLOW (ovalue))
3596 {
3597 if (!TREE_OVERFLOW (value))
3598 {
3599 /* Avoid clobbering a shared constant. */
3600 value = copy_node (value);
3601 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3602 }
3603 }
3604 else if (TREE_OVERFLOW (value))
3605 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3606 value = build_int_cst_wide (TREE_TYPE (value),
3607 TREE_INT_CST_LOW (value),
3608 TREE_INT_CST_HIGH (value));
3609 }
3610 }
3611
3612 /* Don't let a cast be an lvalue. */
3613 if (value == expr)
3614 value = non_lvalue (value);
3615
3616 return value;
3617 }
3618
3619 /* Interpret a cast of expression EXPR to type TYPE. */
3620 tree
3621 c_cast_expr (struct c_type_name *type_name, tree expr)
3622 {
3623 tree type;
3624 int saved_wsp = warn_strict_prototypes;
3625
3626 /* This avoids warnings about unprototyped casts on
3627 integers. E.g. "#define SIG_DFL (void(*)())0". */
3628 if (TREE_CODE (expr) == INTEGER_CST)
3629 warn_strict_prototypes = 0;
3630 type = groktypename (type_name);
3631 warn_strict_prototypes = saved_wsp;
3632
3633 return build_c_cast (type, expr);
3634 }
3635 \f
3636 /* Build an assignment expression of lvalue LHS from value RHS.
3637 MODIFYCODE is the code for a binary operator that we use
3638 to combine the old value of LHS with RHS to get the new value.
3639 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3640
3641 tree
3642 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3643 {
3644 tree result;
3645 tree newrhs;
3646 tree lhstype = TREE_TYPE (lhs);
3647 tree olhstype = lhstype;
3648
3649 /* Types that aren't fully specified cannot be used in assignments. */
3650 lhs = require_complete_type (lhs);
3651
3652 /* Avoid duplicate error messages from operands that had errors. */
3653 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3654 return error_mark_node;
3655
3656 if (!lvalue_or_else (lhs, lv_assign))
3657 return error_mark_node;
3658
3659 STRIP_TYPE_NOPS (rhs);
3660
3661 newrhs = rhs;
3662
3663 /* If a binary op has been requested, combine the old LHS value with the RHS
3664 producing the value we should actually store into the LHS. */
3665
3666 if (modifycode != NOP_EXPR)
3667 {
3668 lhs = stabilize_reference (lhs);
3669 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3670 }
3671
3672 /* Give an error for storing in something that is 'const'. */
3673
3674 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3675 || ((TREE_CODE (lhstype) == RECORD_TYPE
3676 || TREE_CODE (lhstype) == UNION_TYPE)
3677 && C_TYPE_FIELDS_READONLY (lhstype)))
3678 {
3679 readonly_error (lhs, lv_assign);
3680 return error_mark_node;
3681 }
3682
3683 /* If storing into a structure or union member,
3684 it has probably been given type `int'.
3685 Compute the type that would go with
3686 the actual amount of storage the member occupies. */
3687
3688 if (TREE_CODE (lhs) == COMPONENT_REF
3689 && (TREE_CODE (lhstype) == INTEGER_TYPE
3690 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3691 || TREE_CODE (lhstype) == REAL_TYPE
3692 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3693 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3694
3695 /* If storing in a field that is in actuality a short or narrower than one,
3696 we must store in the field in its actual type. */
3697
3698 if (lhstype != TREE_TYPE (lhs))
3699 {
3700 lhs = copy_node (lhs);
3701 TREE_TYPE (lhs) = lhstype;
3702 }
3703
3704 /* Convert new value to destination type. */
3705
3706 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3707 NULL_TREE, NULL_TREE, 0);
3708 if (TREE_CODE (newrhs) == ERROR_MARK)
3709 return error_mark_node;
3710
3711 /* Emit ObjC write barrier, if necessary. */
3712 if (c_dialect_objc () && flag_objc_gc)
3713 {
3714 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3715 if (result)
3716 return result;
3717 }
3718
3719 /* Scan operands. */
3720
3721 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3722 TREE_SIDE_EFFECTS (result) = 1;
3723
3724 /* If we got the LHS in a different type for storing in,
3725 convert the result back to the nominal type of LHS
3726 so that the value we return always has the same type
3727 as the LHS argument. */
3728
3729 if (olhstype == TREE_TYPE (result))
3730 return result;
3731 return convert_for_assignment (olhstype, result, ic_assign,
3732 NULL_TREE, NULL_TREE, 0);
3733 }
3734 \f
3735 /* Convert value RHS to type TYPE as preparation for an assignment
3736 to an lvalue of type TYPE.
3737 The real work of conversion is done by `convert'.
3738 The purpose of this function is to generate error messages
3739 for assignments that are not allowed in C.
3740 ERRTYPE says whether it is argument passing, assignment,
3741 initialization or return.
3742
3743 FUNCTION is a tree for the function being called.
3744 PARMNUM is the number of the argument, for printing in error messages. */
3745
3746 static tree
3747 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3748 tree fundecl, tree function, int parmnum)
3749 {
3750 enum tree_code codel = TREE_CODE (type);
3751 tree rhstype;
3752 enum tree_code coder;
3753 tree rname = NULL_TREE;
3754 bool objc_ok = false;
3755
3756 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3757 {
3758 tree selector;
3759 /* Change pointer to function to the function itself for
3760 diagnostics. */
3761 if (TREE_CODE (function) == ADDR_EXPR
3762 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3763 function = TREE_OPERAND (function, 0);
3764
3765 /* Handle an ObjC selector specially for diagnostics. */
3766 selector = objc_message_selector ();
3767 rname = function;
3768 if (selector && parmnum > 2)
3769 {
3770 rname = selector;
3771 parmnum -= 2;
3772 }
3773 }
3774
3775 /* This macro is used to emit diagnostics to ensure that all format
3776 strings are complete sentences, visible to gettext and checked at
3777 compile time. */
3778 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3779 do { \
3780 switch (errtype) \
3781 { \
3782 case ic_argpass: \
3783 pedwarn (AR, parmnum, rname); \
3784 break; \
3785 case ic_argpass_nonproto: \
3786 warning (0, AR, parmnum, rname); \
3787 break; \
3788 case ic_assign: \
3789 pedwarn (AS); \
3790 break; \
3791 case ic_init: \
3792 pedwarn (IN); \
3793 break; \
3794 case ic_return: \
3795 pedwarn (RE); \
3796 break; \
3797 default: \
3798 gcc_unreachable (); \
3799 } \
3800 } while (0)
3801
3802 STRIP_TYPE_NOPS (rhs);
3803
3804 if (optimize && TREE_CODE (rhs) == VAR_DECL
3805 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
3806 rhs = decl_constant_value_for_broken_optimization (rhs);
3807
3808 rhstype = TREE_TYPE (rhs);
3809 coder = TREE_CODE (rhstype);
3810
3811 if (coder == ERROR_MARK)
3812 return error_mark_node;
3813
3814 if (c_dialect_objc ())
3815 {
3816 int parmno;
3817
3818 switch (errtype)
3819 {
3820 case ic_return:
3821 parmno = 0;
3822 break;
3823
3824 case ic_assign:
3825 parmno = -1;
3826 break;
3827
3828 case ic_init:
3829 parmno = -2;
3830 break;
3831
3832 default:
3833 parmno = parmnum;
3834 break;
3835 }
3836
3837 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
3838 }
3839
3840 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
3841 return rhs;
3842
3843 if (coder == VOID_TYPE)
3844 {
3845 /* Except for passing an argument to an unprototyped function,
3846 this is a constraint violation. When passing an argument to
3847 an unprototyped function, it is compile-time undefined;
3848 making it a constraint in that case was rejected in
3849 DR#252. */
3850 error ("void value not ignored as it ought to be");
3851 return error_mark_node;
3852 }
3853 /* A type converts to a reference to it.
3854 This code doesn't fully support references, it's just for the
3855 special case of va_start and va_copy. */
3856 if (codel == REFERENCE_TYPE
3857 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
3858 {
3859 if (!lvalue_p (rhs))
3860 {
3861 error ("cannot pass rvalue to reference parameter");
3862 return error_mark_node;
3863 }
3864 if (!c_mark_addressable (rhs))
3865 return error_mark_node;
3866 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
3867
3868 /* We already know that these two types are compatible, but they
3869 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3870 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3871 likely to be va_list, a typedef to __builtin_va_list, which
3872 is different enough that it will cause problems later. */
3873 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
3874 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
3875
3876 rhs = build1 (NOP_EXPR, type, rhs);
3877 return rhs;
3878 }
3879 /* Some types can interconvert without explicit casts. */
3880 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
3881 && vector_types_convertible_p (type, TREE_TYPE (rhs), true))
3882 return convert (type, rhs);
3883 /* Arithmetic types all interconvert, and enum is treated like int. */
3884 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
3885 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
3886 || codel == BOOLEAN_TYPE)
3887 && (coder == INTEGER_TYPE || coder == REAL_TYPE
3888 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
3889 || coder == BOOLEAN_TYPE))
3890 return convert_and_check (type, rhs);
3891
3892 /* Conversion to a transparent union from its member types.
3893 This applies only to function arguments. */
3894 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
3895 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
3896 {
3897 tree memb, marginal_memb = NULL_TREE;
3898
3899 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
3900 {
3901 tree memb_type = TREE_TYPE (memb);
3902
3903 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
3904 TYPE_MAIN_VARIANT (rhstype)))
3905 break;
3906
3907 if (TREE_CODE (memb_type) != POINTER_TYPE)
3908 continue;
3909
3910 if (coder == POINTER_TYPE)
3911 {
3912 tree ttl = TREE_TYPE (memb_type);
3913 tree ttr = TREE_TYPE (rhstype);
3914
3915 /* Any non-function converts to a [const][volatile] void *
3916 and vice versa; otherwise, targets must be the same.
3917 Meanwhile, the lhs target must have all the qualifiers of
3918 the rhs. */
3919 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
3920 || comp_target_types (memb_type, rhstype))
3921 {
3922 /* If this type won't generate any warnings, use it. */
3923 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
3924 || ((TREE_CODE (ttr) == FUNCTION_TYPE
3925 && TREE_CODE (ttl) == FUNCTION_TYPE)
3926 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3927 == TYPE_QUALS (ttr))
3928 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3929 == TYPE_QUALS (ttl))))
3930 break;
3931
3932 /* Keep looking for a better type, but remember this one. */
3933 if (!marginal_memb)
3934 marginal_memb = memb;
3935 }
3936 }
3937
3938 /* Can convert integer zero to any pointer type. */
3939 if (null_pointer_constant_p (rhs))
3940 {
3941 rhs = null_pointer_node;
3942 break;
3943 }
3944 }
3945
3946 if (memb || marginal_memb)
3947 {
3948 if (!memb)
3949 {
3950 /* We have only a marginally acceptable member type;
3951 it needs a warning. */
3952 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
3953 tree ttr = TREE_TYPE (rhstype);
3954
3955 /* Const and volatile mean something different for function
3956 types, so the usual warnings are not appropriate. */
3957 if (TREE_CODE (ttr) == FUNCTION_TYPE
3958 && TREE_CODE (ttl) == FUNCTION_TYPE)
3959 {
3960 /* Because const and volatile on functions are
3961 restrictions that say the function will not do
3962 certain things, it is okay to use a const or volatile
3963 function where an ordinary one is wanted, but not
3964 vice-versa. */
3965 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
3966 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE "
3967 "makes qualified function "
3968 "pointer from unqualified"),
3969 G_("assignment makes qualified "
3970 "function pointer from "
3971 "unqualified"),
3972 G_("initialization makes qualified "
3973 "function pointer from "
3974 "unqualified"),
3975 G_("return makes qualified function "
3976 "pointer from unqualified"));
3977 }
3978 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
3979 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
3980 "qualifiers from pointer target type"),
3981 G_("assignment discards qualifiers "
3982 "from pointer target type"),
3983 G_("initialization discards qualifiers "
3984 "from pointer target type"),
3985 G_("return discards qualifiers from "
3986 "pointer target type"));
3987
3988 memb = marginal_memb;
3989 }
3990
3991 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl)))
3992 pedwarn ("ISO C prohibits argument conversion to union type");
3993
3994 return build_constructor_single (type, memb, rhs);
3995 }
3996 }
3997
3998 /* Conversions among pointers */
3999 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4000 && (coder == codel))
4001 {
4002 tree ttl = TREE_TYPE (type);
4003 tree ttr = TREE_TYPE (rhstype);
4004 tree mvl = ttl;
4005 tree mvr = ttr;
4006 bool is_opaque_pointer;
4007 int target_cmp = 0; /* Cache comp_target_types () result. */
4008
4009 if (TREE_CODE (mvl) != ARRAY_TYPE)
4010 mvl = TYPE_MAIN_VARIANT (mvl);
4011 if (TREE_CODE (mvr) != ARRAY_TYPE)
4012 mvr = TYPE_MAIN_VARIANT (mvr);
4013 /* Opaque pointers are treated like void pointers. */
4014 is_opaque_pointer = (targetm.vector_opaque_p (type)
4015 || targetm.vector_opaque_p (rhstype))
4016 && TREE_CODE (ttl) == VECTOR_TYPE
4017 && TREE_CODE (ttr) == VECTOR_TYPE;
4018
4019 /* C++ does not allow the implicit conversion void* -> T*. However,
4020 for the purpose of reducing the number of false positives, we
4021 tolerate the special case of
4022
4023 int *p = NULL;
4024
4025 where NULL is typically defined in C to be '(void *) 0'. */
4026 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4027 warning (OPT_Wc___compat, "request for implicit conversion from "
4028 "%qT to %qT not permitted in C++", rhstype, type);
4029
4030 /* Check if the right-hand side has a format attribute but the
4031 left-hand side doesn't. */
4032 if (warn_missing_format_attribute
4033 && check_missing_format_attribute (type, rhstype))
4034 {
4035 switch (errtype)
4036 {
4037 case ic_argpass:
4038 case ic_argpass_nonproto:
4039 warning (OPT_Wmissing_format_attribute,
4040 "argument %d of %qE might be "
4041 "a candidate for a format attribute",
4042 parmnum, rname);
4043 break;
4044 case ic_assign:
4045 warning (OPT_Wmissing_format_attribute,
4046 "assignment left-hand side might be "
4047 "a candidate for a format attribute");
4048 break;
4049 case ic_init:
4050 warning (OPT_Wmissing_format_attribute,
4051 "initialization left-hand side might be "
4052 "a candidate for a format attribute");
4053 break;
4054 case ic_return:
4055 warning (OPT_Wmissing_format_attribute,
4056 "return type might be "
4057 "a candidate for a format attribute");
4058 break;
4059 default:
4060 gcc_unreachable ();
4061 }
4062 }
4063
4064 /* Any non-function converts to a [const][volatile] void *
4065 and vice versa; otherwise, targets must be the same.
4066 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4067 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4068 || (target_cmp = comp_target_types (type, rhstype))
4069 || is_opaque_pointer
4070 || (c_common_unsigned_type (mvl)
4071 == c_common_unsigned_type (mvr)))
4072 {
4073 if (pedantic
4074 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4075 ||
4076 (VOID_TYPE_P (ttr)
4077 && !null_pointer_constant_p (rhs)
4078 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4079 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of "
4080 "%qE between function pointer "
4081 "and %<void *%>"),
4082 G_("ISO C forbids assignment between "
4083 "function pointer and %<void *%>"),
4084 G_("ISO C forbids initialization between "
4085 "function pointer and %<void *%>"),
4086 G_("ISO C forbids return between function "
4087 "pointer and %<void *%>"));
4088 /* Const and volatile mean something different for function types,
4089 so the usual warnings are not appropriate. */
4090 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4091 && TREE_CODE (ttl) != FUNCTION_TYPE)
4092 {
4093 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4094 {
4095 /* Types differing only by the presence of the 'volatile'
4096 qualifier are acceptable if the 'volatile' has been added
4097 in by the Objective-C EH machinery. */
4098 if (!objc_type_quals_match (ttl, ttr))
4099 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4100 "qualifiers from pointer target type"),
4101 G_("assignment discards qualifiers "
4102 "from pointer target type"),
4103 G_("initialization discards qualifiers "
4104 "from pointer target type"),
4105 G_("return discards qualifiers from "
4106 "pointer target type"));
4107 }
4108 /* If this is not a case of ignoring a mismatch in signedness,
4109 no warning. */
4110 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4111 || target_cmp)
4112 ;
4113 /* If there is a mismatch, do warn. */
4114 else if (warn_pointer_sign)
4115 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument "
4116 "%d of %qE differ in signedness"),
4117 G_("pointer targets in assignment "
4118 "differ in signedness"),
4119 G_("pointer targets in initialization "
4120 "differ in signedness"),
4121 G_("pointer targets in return differ "
4122 "in signedness"));
4123 }
4124 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4125 && TREE_CODE (ttr) == FUNCTION_TYPE)
4126 {
4127 /* Because const and volatile on functions are restrictions
4128 that say the function will not do certain things,
4129 it is okay to use a const or volatile function
4130 where an ordinary one is wanted, but not vice-versa. */
4131 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4132 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4133 "qualified function pointer "
4134 "from unqualified"),
4135 G_("assignment makes qualified function "
4136 "pointer from unqualified"),
4137 G_("initialization makes qualified "
4138 "function pointer from unqualified"),
4139 G_("return makes qualified function "
4140 "pointer from unqualified"));
4141 }
4142 }
4143 else
4144 /* Avoid warning about the volatile ObjC EH puts on decls. */
4145 if (!objc_ok)
4146 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from "
4147 "incompatible pointer type"),
4148 G_("assignment from incompatible pointer type"),
4149 G_("initialization from incompatible "
4150 "pointer type"),
4151 G_("return from incompatible pointer type"));
4152
4153 return convert (type, rhs);
4154 }
4155 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4156 {
4157 /* ??? This should not be an error when inlining calls to
4158 unprototyped functions. */
4159 error ("invalid use of non-lvalue array");
4160 return error_mark_node;
4161 }
4162 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4163 {
4164 /* An explicit constant 0 can convert to a pointer,
4165 or one that results from arithmetic, even including
4166 a cast to integer type. */
4167 if (!null_pointer_constant_p (rhs))
4168 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4169 "pointer from integer without a cast"),
4170 G_("assignment makes pointer from integer "
4171 "without a cast"),
4172 G_("initialization makes pointer from "
4173 "integer without a cast"),
4174 G_("return makes pointer from integer "
4175 "without a cast"));
4176
4177 return convert (type, rhs);
4178 }
4179 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4180 {
4181 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer "
4182 "from pointer without a cast"),
4183 G_("assignment makes integer from pointer "
4184 "without a cast"),
4185 G_("initialization makes integer from pointer "
4186 "without a cast"),
4187 G_("return makes integer from pointer "
4188 "without a cast"));
4189 return convert (type, rhs);
4190 }
4191 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4192 return convert (type, rhs);
4193
4194 switch (errtype)
4195 {
4196 case ic_argpass:
4197 case ic_argpass_nonproto:
4198 /* ??? This should not be an error when inlining calls to
4199 unprototyped functions. */
4200 error ("incompatible type for argument %d of %qE", parmnum, rname);
4201 break;
4202 case ic_assign:
4203 error ("incompatible types in assignment");
4204 break;
4205 case ic_init:
4206 error ("incompatible types in initialization");
4207 break;
4208 case ic_return:
4209 error ("incompatible types in return");
4210 break;
4211 default:
4212 gcc_unreachable ();
4213 }
4214
4215 return error_mark_node;
4216 }
4217
4218 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
4219 is used for error and warning reporting and indicates which argument
4220 is being processed. */
4221
4222 tree
4223 c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum)
4224 {
4225 tree ret, type;
4226
4227 /* If FN was prototyped at the call site, the value has been converted
4228 already in convert_arguments.
4229 However, we might see a prototype now that was not in place when
4230 the function call was seen, so check that the VALUE actually matches
4231 PARM before taking an early exit. */
4232 if (!value
4233 || (TYPE_ARG_TYPES (TREE_TYPE (fn))
4234 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
4235 == TYPE_MAIN_VARIANT (TREE_TYPE (value)))))
4236 return value;
4237
4238 type = TREE_TYPE (parm);
4239 ret = convert_for_assignment (type, value,
4240 ic_argpass_nonproto, fn,
4241 fn, argnum);
4242 if (targetm.calls.promote_prototypes (TREE_TYPE (fn))
4243 && INTEGRAL_TYPE_P (type)
4244 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
4245 ret = default_conversion (ret);
4246 return ret;
4247 }
4248 \f
4249 /* If VALUE is a compound expr all of whose expressions are constant, then
4250 return its value. Otherwise, return error_mark_node.
4251
4252 This is for handling COMPOUND_EXPRs as initializer elements
4253 which is allowed with a warning when -pedantic is specified. */
4254
4255 static tree
4256 valid_compound_expr_initializer (tree value, tree endtype)
4257 {
4258 if (TREE_CODE (value) == COMPOUND_EXPR)
4259 {
4260 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4261 == error_mark_node)
4262 return error_mark_node;
4263 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4264 endtype);
4265 }
4266 else if (!initializer_constant_valid_p (value, endtype))
4267 return error_mark_node;
4268 else
4269 return value;
4270 }
4271 \f
4272 /* Perform appropriate conversions on the initial value of a variable,
4273 store it in the declaration DECL,
4274 and print any error messages that are appropriate.
4275 If the init is invalid, store an ERROR_MARK. */
4276
4277 void
4278 store_init_value (tree decl, tree init)
4279 {
4280 tree value, type;
4281
4282 /* If variable's type was invalidly declared, just ignore it. */
4283
4284 type = TREE_TYPE (decl);
4285 if (TREE_CODE (type) == ERROR_MARK)
4286 return;
4287
4288 /* Digest the specified initializer into an expression. */
4289
4290 value = digest_init (type, init, true, TREE_STATIC (decl));
4291
4292 /* Store the expression if valid; else report error. */
4293
4294 if (!in_system_header
4295 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4296 warning (OPT_Wtraditional, "traditional C rejects automatic "
4297 "aggregate initialization");
4298
4299 DECL_INITIAL (decl) = value;
4300
4301 /* ANSI wants warnings about out-of-range constant initializers. */
4302 STRIP_TYPE_NOPS (value);
4303 if (TREE_STATIC (decl))
4304 constant_expression_warning (value);
4305
4306 /* Check if we need to set array size from compound literal size. */
4307 if (TREE_CODE (type) == ARRAY_TYPE
4308 && TYPE_DOMAIN (type) == 0
4309 && value != error_mark_node)
4310 {
4311 tree inside_init = init;
4312
4313 STRIP_TYPE_NOPS (inside_init);
4314 inside_init = fold (inside_init);
4315
4316 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4317 {
4318 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4319
4320 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4321 {
4322 /* For int foo[] = (int [3]){1}; we need to set array size
4323 now since later on array initializer will be just the
4324 brace enclosed list of the compound literal. */
4325 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4326 TREE_TYPE (decl) = type;
4327 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4328 layout_type (type);
4329 layout_decl (cldecl, 0);
4330 }
4331 }
4332 }
4333 }
4334 \f
4335 /* Methods for storing and printing names for error messages. */
4336
4337 /* Implement a spelling stack that allows components of a name to be pushed
4338 and popped. Each element on the stack is this structure. */
4339
4340 struct spelling
4341 {
4342 int kind;
4343 union
4344 {
4345 unsigned HOST_WIDE_INT i;
4346 const char *s;
4347 } u;
4348 };
4349
4350 #define SPELLING_STRING 1
4351 #define SPELLING_MEMBER 2
4352 #define SPELLING_BOUNDS 3
4353
4354 static struct spelling *spelling; /* Next stack element (unused). */
4355 static struct spelling *spelling_base; /* Spelling stack base. */
4356 static int spelling_size; /* Size of the spelling stack. */
4357
4358 /* Macros to save and restore the spelling stack around push_... functions.
4359 Alternative to SAVE_SPELLING_STACK. */
4360
4361 #define SPELLING_DEPTH() (spelling - spelling_base)
4362 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4363
4364 /* Push an element on the spelling stack with type KIND and assign VALUE
4365 to MEMBER. */
4366
4367 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4368 { \
4369 int depth = SPELLING_DEPTH (); \
4370 \
4371 if (depth >= spelling_size) \
4372 { \
4373 spelling_size += 10; \
4374 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4375 spelling_size); \
4376 RESTORE_SPELLING_DEPTH (depth); \
4377 } \
4378 \
4379 spelling->kind = (KIND); \
4380 spelling->MEMBER = (VALUE); \
4381 spelling++; \
4382 }
4383
4384 /* Push STRING on the stack. Printed literally. */
4385
4386 static void
4387 push_string (const char *string)
4388 {
4389 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4390 }
4391
4392 /* Push a member name on the stack. Printed as '.' STRING. */
4393
4394 static void
4395 push_member_name (tree decl)
4396 {
4397 const char *const string
4398 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4399 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4400 }
4401
4402 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4403
4404 static void
4405 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4406 {
4407 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4408 }
4409
4410 /* Compute the maximum size in bytes of the printed spelling. */
4411
4412 static int
4413 spelling_length (void)
4414 {
4415 int size = 0;
4416 struct spelling *p;
4417
4418 for (p = spelling_base; p < spelling; p++)
4419 {
4420 if (p->kind == SPELLING_BOUNDS)
4421 size += 25;
4422 else
4423 size += strlen (p->u.s) + 1;
4424 }
4425
4426 return size;
4427 }
4428
4429 /* Print the spelling to BUFFER and return it. */
4430
4431 static char *
4432 print_spelling (char *buffer)
4433 {
4434 char *d = buffer;
4435 struct spelling *p;
4436
4437 for (p = spelling_base; p < spelling; p++)
4438 if (p->kind == SPELLING_BOUNDS)
4439 {
4440 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4441 d += strlen (d);
4442 }
4443 else
4444 {
4445 const char *s;
4446 if (p->kind == SPELLING_MEMBER)
4447 *d++ = '.';
4448 for (s = p->u.s; (*d = *s++); d++)
4449 ;
4450 }
4451 *d++ = '\0';
4452 return buffer;
4453 }
4454
4455 /* Issue an error message for a bad initializer component.
4456 MSGID identifies the message.
4457 The component name is taken from the spelling stack. */
4458
4459 void
4460 error_init (const char *msgid)
4461 {
4462 char *ofwhat;
4463
4464 error ("%s", _(msgid));
4465 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4466 if (*ofwhat)
4467 error ("(near initialization for %qs)", ofwhat);
4468 }
4469
4470 /* Issue a pedantic warning for a bad initializer component.
4471 MSGID identifies the message.
4472 The component name is taken from the spelling stack. */
4473
4474 void
4475 pedwarn_init (const char *msgid)
4476 {
4477 char *ofwhat;
4478
4479 pedwarn ("%s", _(msgid));
4480 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4481 if (*ofwhat)
4482 pedwarn ("(near initialization for %qs)", ofwhat);
4483 }
4484
4485 /* Issue a warning for a bad initializer component.
4486 MSGID identifies the message.
4487 The component name is taken from the spelling stack. */
4488
4489 static void
4490 warning_init (const char *msgid)
4491 {
4492 char *ofwhat;
4493
4494 warning (0, "%s", _(msgid));
4495 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4496 if (*ofwhat)
4497 warning (0, "(near initialization for %qs)", ofwhat);
4498 }
4499 \f
4500 /* If TYPE is an array type and EXPR is a parenthesized string
4501 constant, warn if pedantic that EXPR is being used to initialize an
4502 object of type TYPE. */
4503
4504 void
4505 maybe_warn_string_init (tree type, struct c_expr expr)
4506 {
4507 if (pedantic
4508 && TREE_CODE (type) == ARRAY_TYPE
4509 && TREE_CODE (expr.value) == STRING_CST
4510 && expr.original_code != STRING_CST)
4511 pedwarn_init ("array initialized from parenthesized string constant");
4512 }
4513
4514 /* Digest the parser output INIT as an initializer for type TYPE.
4515 Return a C expression of type TYPE to represent the initial value.
4516
4517 If INIT is a string constant, STRICT_STRING is true if it is
4518 unparenthesized or we should not warn here for it being parenthesized.
4519 For other types of INIT, STRICT_STRING is not used.
4520
4521 REQUIRE_CONSTANT requests an error if non-constant initializers or
4522 elements are seen. */
4523
4524 static tree
4525 digest_init (tree type, tree init, bool strict_string, int require_constant)
4526 {
4527 enum tree_code code = TREE_CODE (type);
4528 tree inside_init = init;
4529
4530 if (type == error_mark_node
4531 || !init
4532 || init == error_mark_node
4533 || TREE_TYPE (init) == error_mark_node)
4534 return error_mark_node;
4535
4536 STRIP_TYPE_NOPS (inside_init);
4537
4538 inside_init = fold (inside_init);
4539
4540 /* Initialization of an array of chars from a string constant
4541 optionally enclosed in braces. */
4542
4543 if (code == ARRAY_TYPE && inside_init
4544 && TREE_CODE (inside_init) == STRING_CST)
4545 {
4546 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4547 /* Note that an array could be both an array of character type
4548 and an array of wchar_t if wchar_t is signed char or unsigned
4549 char. */
4550 bool char_array = (typ1 == char_type_node
4551 || typ1 == signed_char_type_node
4552 || typ1 == unsigned_char_type_node);
4553 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4554 if (char_array || wchar_array)
4555 {
4556 struct c_expr expr;
4557 bool char_string;
4558 expr.value = inside_init;
4559 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4560 maybe_warn_string_init (type, expr);
4561
4562 char_string
4563 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4564 == char_type_node);
4565
4566 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4567 TYPE_MAIN_VARIANT (type)))
4568 return inside_init;
4569
4570 if (!wchar_array && !char_string)
4571 {
4572 error_init ("char-array initialized from wide string");
4573 return error_mark_node;
4574 }
4575 if (char_string && !char_array)
4576 {
4577 error_init ("wchar_t-array initialized from non-wide string");
4578 return error_mark_node;
4579 }
4580
4581 TREE_TYPE (inside_init) = type;
4582 if (TYPE_DOMAIN (type) != 0
4583 && TYPE_SIZE (type) != 0
4584 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4585 /* Subtract 1 (or sizeof (wchar_t))
4586 because it's ok to ignore the terminating null char
4587 that is counted in the length of the constant. */
4588 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4589 TREE_STRING_LENGTH (inside_init)
4590 - ((TYPE_PRECISION (typ1)
4591 != TYPE_PRECISION (char_type_node))
4592 ? (TYPE_PRECISION (wchar_type_node)
4593 / BITS_PER_UNIT)
4594 : 1)))
4595 pedwarn_init ("initializer-string for array of chars is too long");
4596
4597 return inside_init;
4598 }
4599 else if (INTEGRAL_TYPE_P (typ1))
4600 {
4601 error_init ("array of inappropriate type initialized "
4602 "from string constant");
4603 return error_mark_node;
4604 }
4605 }
4606
4607 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4608 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4609 below and handle as a constructor. */
4610 if (code == VECTOR_TYPE
4611 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4612 && vector_types_convertible_p (TREE_TYPE (inside_init), type, true)
4613 && TREE_CONSTANT (inside_init))
4614 {
4615 if (TREE_CODE (inside_init) == VECTOR_CST
4616 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4617 TYPE_MAIN_VARIANT (type)))
4618 return inside_init;
4619
4620 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4621 {
4622 unsigned HOST_WIDE_INT ix;
4623 tree value;
4624 bool constant_p = true;
4625
4626 /* Iterate through elements and check if all constructor
4627 elements are *_CSTs. */
4628 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4629 if (!CONSTANT_CLASS_P (value))
4630 {
4631 constant_p = false;
4632 break;
4633 }
4634
4635 if (constant_p)
4636 return build_vector_from_ctor (type,
4637 CONSTRUCTOR_ELTS (inside_init));
4638 }
4639 }
4640
4641 /* Any type can be initialized
4642 from an expression of the same type, optionally with braces. */
4643
4644 if (inside_init && TREE_TYPE (inside_init) != 0
4645 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4646 TYPE_MAIN_VARIANT (type))
4647 || (code == ARRAY_TYPE
4648 && comptypes (TREE_TYPE (inside_init), type))
4649 || (code == VECTOR_TYPE
4650 && comptypes (TREE_TYPE (inside_init), type))
4651 || (code == POINTER_TYPE
4652 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4653 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4654 TREE_TYPE (type)))))
4655 {
4656 if (code == POINTER_TYPE)
4657 {
4658 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4659 {
4660 if (TREE_CODE (inside_init) == STRING_CST
4661 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4662 inside_init = array_to_pointer_conversion (inside_init);
4663 else
4664 {
4665 error_init ("invalid use of non-lvalue array");
4666 return error_mark_node;
4667 }
4668 }
4669 }
4670
4671 if (code == VECTOR_TYPE)
4672 /* Although the types are compatible, we may require a
4673 conversion. */
4674 inside_init = convert (type, inside_init);
4675
4676 if (require_constant
4677 && (code == VECTOR_TYPE || !flag_isoc99)
4678 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4679 {
4680 /* As an extension, allow initializing objects with static storage
4681 duration with compound literals (which are then treated just as
4682 the brace enclosed list they contain). Also allow this for
4683 vectors, as we can only assign them with compound literals. */
4684 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4685 inside_init = DECL_INITIAL (decl);
4686 }
4687
4688 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4689 && TREE_CODE (inside_init) != CONSTRUCTOR)
4690 {
4691 error_init ("array initialized from non-constant array expression");
4692 return error_mark_node;
4693 }
4694
4695 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4696 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4697
4698 /* Compound expressions can only occur here if -pedantic or
4699 -pedantic-errors is specified. In the later case, we always want
4700 an error. In the former case, we simply want a warning. */
4701 if (require_constant && pedantic
4702 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4703 {
4704 inside_init
4705 = valid_compound_expr_initializer (inside_init,
4706 TREE_TYPE (inside_init));
4707 if (inside_init == error_mark_node)
4708 error_init ("initializer element is not constant");
4709 else
4710 pedwarn_init ("initializer element is not constant");
4711 if (flag_pedantic_errors)
4712 inside_init = error_mark_node;
4713 }
4714 else if (require_constant
4715 && !initializer_constant_valid_p (inside_init,
4716 TREE_TYPE (inside_init)))
4717 {
4718 error_init ("initializer element is not constant");
4719 inside_init = error_mark_node;
4720 }
4721
4722 /* Added to enable additional -Wmissing-format-attribute warnings. */
4723 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4724 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4725 NULL_TREE, 0);
4726 return inside_init;
4727 }
4728
4729 /* Handle scalar types, including conversions. */
4730
4731 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4732 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE
4733 || code == VECTOR_TYPE)
4734 {
4735 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4736 && (TREE_CODE (init) == STRING_CST
4737 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4738 init = array_to_pointer_conversion (init);
4739 inside_init
4740 = convert_for_assignment (type, init, ic_init,
4741 NULL_TREE, NULL_TREE, 0);
4742
4743 /* Check to see if we have already given an error message. */
4744 if (inside_init == error_mark_node)
4745 ;
4746 else if (require_constant && !TREE_CONSTANT (inside_init))
4747 {
4748 error_init ("initializer element is not constant");
4749 inside_init = error_mark_node;
4750 }
4751 else if (require_constant
4752 && !initializer_constant_valid_p (inside_init,
4753 TREE_TYPE (inside_init)))
4754 {
4755 error_init ("initializer element is not computable at load time");
4756 inside_init = error_mark_node;
4757 }
4758
4759 return inside_init;
4760 }
4761
4762 /* Come here only for records and arrays. */
4763
4764 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4765 {
4766 error_init ("variable-sized object may not be initialized");
4767 return error_mark_node;
4768 }
4769
4770 error_init ("invalid initializer");
4771 return error_mark_node;
4772 }
4773 \f
4774 /* Handle initializers that use braces. */
4775
4776 /* Type of object we are accumulating a constructor for.
4777 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4778 static tree constructor_type;
4779
4780 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4781 left to fill. */
4782 static tree constructor_fields;
4783
4784 /* For an ARRAY_TYPE, this is the specified index
4785 at which to store the next element we get. */
4786 static tree constructor_index;
4787
4788 /* For an ARRAY_TYPE, this is the maximum index. */
4789 static tree constructor_max_index;
4790
4791 /* For a RECORD_TYPE, this is the first field not yet written out. */
4792 static tree constructor_unfilled_fields;
4793
4794 /* For an ARRAY_TYPE, this is the index of the first element
4795 not yet written out. */
4796 static tree constructor_unfilled_index;
4797
4798 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4799 This is so we can generate gaps between fields, when appropriate. */
4800 static tree constructor_bit_index;
4801
4802 /* If we are saving up the elements rather than allocating them,
4803 this is the list of elements so far (in reverse order,
4804 most recent first). */
4805 static VEC(constructor_elt,gc) *constructor_elements;
4806
4807 /* 1 if constructor should be incrementally stored into a constructor chain,
4808 0 if all the elements should be kept in AVL tree. */
4809 static int constructor_incremental;
4810
4811 /* 1 if so far this constructor's elements are all compile-time constants. */
4812 static int constructor_constant;
4813
4814 /* 1 if so far this constructor's elements are all valid address constants. */
4815 static int constructor_simple;
4816
4817 /* 1 if this constructor is erroneous so far. */
4818 static int constructor_erroneous;
4819
4820 /* Structure for managing pending initializer elements, organized as an
4821 AVL tree. */
4822
4823 struct init_node
4824 {
4825 struct init_node *left, *right;
4826 struct init_node *parent;
4827 int balance;
4828 tree purpose;
4829 tree value;
4830 };
4831
4832 /* Tree of pending elements at this constructor level.
4833 These are elements encountered out of order
4834 which belong at places we haven't reached yet in actually
4835 writing the output.
4836 Will never hold tree nodes across GC runs. */
4837 static struct init_node *constructor_pending_elts;
4838
4839 /* The SPELLING_DEPTH of this constructor. */
4840 static int constructor_depth;
4841
4842 /* DECL node for which an initializer is being read.
4843 0 means we are reading a constructor expression
4844 such as (struct foo) {...}. */
4845 static tree constructor_decl;
4846
4847 /* Nonzero if this is an initializer for a top-level decl. */
4848 static int constructor_top_level;
4849
4850 /* Nonzero if there were any member designators in this initializer. */
4851 static int constructor_designated;
4852
4853 /* Nesting depth of designator list. */
4854 static int designator_depth;
4855
4856 /* Nonzero if there were diagnosed errors in this designator list. */
4857 static int designator_erroneous;
4858
4859 \f
4860 /* This stack has a level for each implicit or explicit level of
4861 structuring in the initializer, including the outermost one. It
4862 saves the values of most of the variables above. */
4863
4864 struct constructor_range_stack;
4865
4866 struct constructor_stack
4867 {
4868 struct constructor_stack *next;
4869 tree type;
4870 tree fields;
4871 tree index;
4872 tree max_index;
4873 tree unfilled_index;
4874 tree unfilled_fields;
4875 tree bit_index;
4876 VEC(constructor_elt,gc) *elements;
4877 struct init_node *pending_elts;
4878 int offset;
4879 int depth;
4880 /* If value nonzero, this value should replace the entire
4881 constructor at this level. */
4882 struct c_expr replacement_value;
4883 struct constructor_range_stack *range_stack;
4884 char constant;
4885 char simple;
4886 char implicit;
4887 char erroneous;
4888 char outer;
4889 char incremental;
4890 char designated;
4891 };
4892
4893 static struct constructor_stack *constructor_stack;
4894
4895 /* This stack represents designators from some range designator up to
4896 the last designator in the list. */
4897
4898 struct constructor_range_stack
4899 {
4900 struct constructor_range_stack *next, *prev;
4901 struct constructor_stack *stack;
4902 tree range_start;
4903 tree index;
4904 tree range_end;
4905 tree fields;
4906 };
4907
4908 static struct constructor_range_stack *constructor_range_stack;
4909
4910 /* This stack records separate initializers that are nested.
4911 Nested initializers can't happen in ANSI C, but GNU C allows them
4912 in cases like { ... (struct foo) { ... } ... }. */
4913
4914 struct initializer_stack
4915 {
4916 struct initializer_stack *next;
4917 tree decl;
4918 struct constructor_stack *constructor_stack;
4919 struct constructor_range_stack *constructor_range_stack;
4920 VEC(constructor_elt,gc) *elements;
4921 struct spelling *spelling;
4922 struct spelling *spelling_base;
4923 int spelling_size;
4924 char top_level;
4925 char require_constant_value;
4926 char require_constant_elements;
4927 };
4928
4929 static struct initializer_stack *initializer_stack;
4930 \f
4931 /* Prepare to parse and output the initializer for variable DECL. */
4932
4933 void
4934 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
4935 {
4936 const char *locus;
4937 struct initializer_stack *p = XNEW (struct initializer_stack);
4938
4939 p->decl = constructor_decl;
4940 p->require_constant_value = require_constant_value;
4941 p->require_constant_elements = require_constant_elements;
4942 p->constructor_stack = constructor_stack;
4943 p->constructor_range_stack = constructor_range_stack;
4944 p->elements = constructor_elements;
4945 p->spelling = spelling;
4946 p->spelling_base = spelling_base;
4947 p->spelling_size = spelling_size;
4948 p->top_level = constructor_top_level;
4949 p->next = initializer_stack;
4950 initializer_stack = p;
4951
4952 constructor_decl = decl;
4953 constructor_designated = 0;
4954 constructor_top_level = top_level;
4955
4956 if (decl != 0 && decl != error_mark_node)
4957 {
4958 require_constant_value = TREE_STATIC (decl);
4959 require_constant_elements
4960 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
4961 /* For a scalar, you can always use any value to initialize,
4962 even within braces. */
4963 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
4964 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
4965 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
4966 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
4967 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
4968 }
4969 else
4970 {
4971 require_constant_value = 0;
4972 require_constant_elements = 0;
4973 locus = "(anonymous)";
4974 }
4975
4976 constructor_stack = 0;
4977 constructor_range_stack = 0;
4978
4979 missing_braces_mentioned = 0;
4980
4981 spelling_base = 0;
4982 spelling_size = 0;
4983 RESTORE_SPELLING_DEPTH (0);
4984
4985 if (locus)
4986 push_string (locus);
4987 }
4988
4989 void
4990 finish_init (void)
4991 {
4992 struct initializer_stack *p = initializer_stack;
4993
4994 /* Free the whole constructor stack of this initializer. */
4995 while (constructor_stack)
4996 {
4997 struct constructor_stack *q = constructor_stack;
4998 constructor_stack = q->next;
4999 free (q);
5000 }
5001
5002 gcc_assert (!constructor_range_stack);
5003
5004 /* Pop back to the data of the outer initializer (if any). */
5005 free (spelling_base);
5006
5007 constructor_decl = p->decl;
5008 require_constant_value = p->require_constant_value;
5009 require_constant_elements = p->require_constant_elements;
5010 constructor_stack = p->constructor_stack;
5011 constructor_range_stack = p->constructor_range_stack;
5012 constructor_elements = p->elements;
5013 spelling = p->spelling;
5014 spelling_base = p->spelling_base;
5015 spelling_size = p->spelling_size;
5016 constructor_top_level = p->top_level;
5017 initializer_stack = p->next;
5018 free (p);
5019 }
5020 \f
5021 /* Call here when we see the initializer is surrounded by braces.
5022 This is instead of a call to push_init_level;
5023 it is matched by a call to pop_init_level.
5024
5025 TYPE is the type to initialize, for a constructor expression.
5026 For an initializer for a decl, TYPE is zero. */
5027
5028 void
5029 really_start_incremental_init (tree type)
5030 {
5031 struct constructor_stack *p = XNEW (struct constructor_stack);
5032
5033 if (type == 0)
5034 type = TREE_TYPE (constructor_decl);
5035
5036 if (targetm.vector_opaque_p (type))
5037 error ("opaque vector types cannot be initialized");
5038
5039 p->type = constructor_type;
5040 p->fields = constructor_fields;
5041 p->index = constructor_index;
5042 p->max_index = constructor_max_index;
5043 p->unfilled_index = constructor_unfilled_index;
5044 p->unfilled_fields = constructor_unfilled_fields;
5045 p->bit_index = constructor_bit_index;
5046 p->elements = constructor_elements;
5047 p->constant = constructor_constant;
5048 p->simple = constructor_simple;
5049 p->erroneous = constructor_erroneous;
5050 p->pending_elts = constructor_pending_elts;
5051 p->depth = constructor_depth;
5052 p->replacement_value.value = 0;
5053 p->replacement_value.original_code = ERROR_MARK;
5054 p->implicit = 0;
5055 p->range_stack = 0;
5056 p->outer = 0;
5057 p->incremental = constructor_incremental;
5058 p->designated = constructor_designated;
5059 p->next = 0;
5060 constructor_stack = p;
5061
5062 constructor_constant = 1;
5063 constructor_simple = 1;
5064 constructor_depth = SPELLING_DEPTH ();
5065 constructor_elements = 0;
5066 constructor_pending_elts = 0;
5067 constructor_type = type;
5068 constructor_incremental = 1;
5069 constructor_designated = 0;
5070 designator_depth = 0;
5071 designator_erroneous = 0;
5072
5073 if (TREE_CODE (constructor_type) == RECORD_TYPE
5074 || TREE_CODE (constructor_type) == UNION_TYPE)
5075 {
5076 constructor_fields = TYPE_FIELDS (constructor_type);
5077 /* Skip any nameless bit fields at the beginning. */
5078 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5079 && DECL_NAME (constructor_fields) == 0)
5080 constructor_fields = TREE_CHAIN (constructor_fields);
5081
5082 constructor_unfilled_fields = constructor_fields;
5083 constructor_bit_index = bitsize_zero_node;
5084 }
5085 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5086 {
5087 if (TYPE_DOMAIN (constructor_type))
5088 {
5089 constructor_max_index
5090 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5091
5092 /* Detect non-empty initializations of zero-length arrays. */
5093 if (constructor_max_index == NULL_TREE
5094 && TYPE_SIZE (constructor_type))
5095 constructor_max_index = build_int_cst (NULL_TREE, -1);
5096
5097 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5098 to initialize VLAs will cause a proper error; avoid tree
5099 checking errors as well by setting a safe value. */
5100 if (constructor_max_index
5101 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5102 constructor_max_index = build_int_cst (NULL_TREE, -1);
5103
5104 constructor_index
5105 = convert (bitsizetype,
5106 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5107 }
5108 else
5109 {
5110 constructor_index = bitsize_zero_node;
5111 constructor_max_index = NULL_TREE;
5112 }
5113
5114 constructor_unfilled_index = constructor_index;
5115 }
5116 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5117 {
5118 /* Vectors are like simple fixed-size arrays. */
5119 constructor_max_index =
5120 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5121 constructor_index = bitsize_zero_node;
5122 constructor_unfilled_index = constructor_index;
5123 }
5124 else
5125 {
5126 /* Handle the case of int x = {5}; */
5127 constructor_fields = constructor_type;
5128 constructor_unfilled_fields = constructor_type;
5129 }
5130 }
5131 \f
5132 /* Push down into a subobject, for initialization.
5133 If this is for an explicit set of braces, IMPLICIT is 0.
5134 If it is because the next element belongs at a lower level,
5135 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5136
5137 void
5138 push_init_level (int implicit)
5139 {
5140 struct constructor_stack *p;
5141 tree value = NULL_TREE;
5142
5143 /* If we've exhausted any levels that didn't have braces,
5144 pop them now. If implicit == 1, this will have been done in
5145 process_init_element; do not repeat it here because in the case
5146 of excess initializers for an empty aggregate this leads to an
5147 infinite cycle of popping a level and immediately recreating
5148 it. */
5149 if (implicit != 1)
5150 {
5151 while (constructor_stack->implicit)
5152 {
5153 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5154 || TREE_CODE (constructor_type) == UNION_TYPE)
5155 && constructor_fields == 0)
5156 process_init_element (pop_init_level (1));
5157 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5158 && constructor_max_index
5159 && tree_int_cst_lt (constructor_max_index,
5160 constructor_index))
5161 process_init_element (pop_init_level (1));
5162 else
5163 break;
5164 }
5165 }
5166
5167 /* Unless this is an explicit brace, we need to preserve previous
5168 content if any. */
5169 if (implicit)
5170 {
5171 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5172 || TREE_CODE (constructor_type) == UNION_TYPE)
5173 && constructor_fields)
5174 value = find_init_member (constructor_fields);
5175 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5176 value = find_init_member (constructor_index);
5177 }
5178
5179 p = XNEW (struct constructor_stack);
5180 p->type = constructor_type;
5181 p->fields = constructor_fields;
5182 p->index = constructor_index;
5183 p->max_index = constructor_max_index;
5184 p->unfilled_index = constructor_unfilled_index;
5185 p->unfilled_fields = constructor_unfilled_fields;
5186 p->bit_index = constructor_bit_index;
5187 p->elements = constructor_elements;
5188 p->constant = constructor_constant;
5189 p->simple = constructor_simple;
5190 p->erroneous = constructor_erroneous;
5191 p->pending_elts = constructor_pending_elts;
5192 p->depth = constructor_depth;
5193 p->replacement_value.value = 0;
5194 p->replacement_value.original_code = ERROR_MARK;
5195 p->implicit = implicit;
5196 p->outer = 0;
5197 p->incremental = constructor_incremental;
5198 p->designated = constructor_designated;
5199 p->next = constructor_stack;
5200 p->range_stack = 0;
5201 constructor_stack = p;
5202
5203 constructor_constant = 1;
5204 constructor_simple = 1;
5205 constructor_depth = SPELLING_DEPTH ();
5206 constructor_elements = 0;
5207 constructor_incremental = 1;
5208 constructor_designated = 0;
5209 constructor_pending_elts = 0;
5210 if (!implicit)
5211 {
5212 p->range_stack = constructor_range_stack;
5213 constructor_range_stack = 0;
5214 designator_depth = 0;
5215 designator_erroneous = 0;
5216 }
5217
5218 /* Don't die if an entire brace-pair level is superfluous
5219 in the containing level. */
5220 if (constructor_type == 0)
5221 ;
5222 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5223 || TREE_CODE (constructor_type) == UNION_TYPE)
5224 {
5225 /* Don't die if there are extra init elts at the end. */
5226 if (constructor_fields == 0)
5227 constructor_type = 0;
5228 else
5229 {
5230 constructor_type = TREE_TYPE (constructor_fields);
5231 push_member_name (constructor_fields);
5232 constructor_depth++;
5233 }
5234 }
5235 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5236 {
5237 constructor_type = TREE_TYPE (constructor_type);
5238 push_array_bounds (tree_low_cst (constructor_index, 1));
5239 constructor_depth++;
5240 }
5241
5242 if (constructor_type == 0)
5243 {
5244 error_init ("extra brace group at end of initializer");
5245 constructor_fields = 0;
5246 constructor_unfilled_fields = 0;
5247 return;
5248 }
5249
5250 if (value && TREE_CODE (value) == CONSTRUCTOR)
5251 {
5252 constructor_constant = TREE_CONSTANT (value);
5253 constructor_simple = TREE_STATIC (value);
5254 constructor_elements = CONSTRUCTOR_ELTS (value);
5255 if (!VEC_empty (constructor_elt, constructor_elements)
5256 && (TREE_CODE (constructor_type) == RECORD_TYPE
5257 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5258 set_nonincremental_init ();
5259 }
5260
5261 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5262 {
5263 missing_braces_mentioned = 1;
5264 warning_init ("missing braces around initializer");
5265 }
5266
5267 if (TREE_CODE (constructor_type) == RECORD_TYPE
5268 || TREE_CODE (constructor_type) == UNION_TYPE)
5269 {
5270 constructor_fields = TYPE_FIELDS (constructor_type);
5271 /* Skip any nameless bit fields at the beginning. */
5272 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5273 && DECL_NAME (constructor_fields) == 0)
5274 constructor_fields = TREE_CHAIN (constructor_fields);
5275
5276 constructor_unfilled_fields = constructor_fields;
5277 constructor_bit_index = bitsize_zero_node;
5278 }
5279 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5280 {
5281 /* Vectors are like simple fixed-size arrays. */
5282 constructor_max_index =
5283 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5284 constructor_index = convert (bitsizetype, integer_zero_node);
5285 constructor_unfilled_index = constructor_index;
5286 }
5287 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5288 {
5289 if (TYPE_DOMAIN (constructor_type))
5290 {
5291 constructor_max_index
5292 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5293
5294 /* Detect non-empty initializations of zero-length arrays. */
5295 if (constructor_max_index == NULL_TREE
5296 && TYPE_SIZE (constructor_type))
5297 constructor_max_index = build_int_cst (NULL_TREE, -1);
5298
5299 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5300 to initialize VLAs will cause a proper error; avoid tree
5301 checking errors as well by setting a safe value. */
5302 if (constructor_max_index
5303 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5304 constructor_max_index = build_int_cst (NULL_TREE, -1);
5305
5306 constructor_index
5307 = convert (bitsizetype,
5308 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5309 }
5310 else
5311 constructor_index = bitsize_zero_node;
5312
5313 constructor_unfilled_index = constructor_index;
5314 if (value && TREE_CODE (value) == STRING_CST)
5315 {
5316 /* We need to split the char/wchar array into individual
5317 characters, so that we don't have to special case it
5318 everywhere. */
5319 set_nonincremental_init_from_string (value);
5320 }
5321 }
5322 else
5323 {
5324 if (constructor_type != error_mark_node)
5325 warning_init ("braces around scalar initializer");
5326 constructor_fields = constructor_type;
5327 constructor_unfilled_fields = constructor_type;
5328 }
5329 }
5330
5331 /* At the end of an implicit or explicit brace level,
5332 finish up that level of constructor. If a single expression
5333 with redundant braces initialized that level, return the
5334 c_expr structure for that expression. Otherwise, the original_code
5335 element is set to ERROR_MARK.
5336 If we were outputting the elements as they are read, return 0 as the value
5337 from inner levels (process_init_element ignores that),
5338 but return error_mark_node as the value from the outermost level
5339 (that's what we want to put in DECL_INITIAL).
5340 Otherwise, return a CONSTRUCTOR expression as the value. */
5341
5342 struct c_expr
5343 pop_init_level (int implicit)
5344 {
5345 struct constructor_stack *p;
5346 struct c_expr ret;
5347 ret.value = 0;
5348 ret.original_code = ERROR_MARK;
5349
5350 if (implicit == 0)
5351 {
5352 /* When we come to an explicit close brace,
5353 pop any inner levels that didn't have explicit braces. */
5354 while (constructor_stack->implicit)
5355 process_init_element (pop_init_level (1));
5356
5357 gcc_assert (!constructor_range_stack);
5358 }
5359
5360 /* Now output all pending elements. */
5361 constructor_incremental = 1;
5362 output_pending_init_elements (1);
5363
5364 p = constructor_stack;
5365
5366 /* Error for initializing a flexible array member, or a zero-length
5367 array member in an inappropriate context. */
5368 if (constructor_type && constructor_fields
5369 && TREE_CODE (constructor_type) == ARRAY_TYPE
5370 && TYPE_DOMAIN (constructor_type)
5371 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5372 {
5373 /* Silently discard empty initializations. The parser will
5374 already have pedwarned for empty brackets. */
5375 if (integer_zerop (constructor_unfilled_index))
5376 constructor_type = NULL_TREE;
5377 else
5378 {
5379 gcc_assert (!TYPE_SIZE (constructor_type));
5380
5381 if (constructor_depth > 2)
5382 error_init ("initialization of flexible array member in a nested context");
5383 else if (pedantic)
5384 pedwarn_init ("initialization of a flexible array member");
5385
5386 /* We have already issued an error message for the existence
5387 of a flexible array member not at the end of the structure.
5388 Discard the initializer so that we do not die later. */
5389 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5390 constructor_type = NULL_TREE;
5391 }
5392 }
5393
5394 /* Warn when some struct elements are implicitly initialized to zero. */
5395 if (warn_missing_field_initializers
5396 && constructor_type
5397 && TREE_CODE (constructor_type) == RECORD_TYPE
5398 && constructor_unfilled_fields)
5399 {
5400 /* Do not warn for flexible array members or zero-length arrays. */
5401 while (constructor_unfilled_fields
5402 && (!DECL_SIZE (constructor_unfilled_fields)
5403 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5404 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5405
5406 /* Do not warn if this level of the initializer uses member
5407 designators; it is likely to be deliberate. */
5408 if (constructor_unfilled_fields && !constructor_designated)
5409 {
5410 push_member_name (constructor_unfilled_fields);
5411 warning_init ("missing initializer");
5412 RESTORE_SPELLING_DEPTH (constructor_depth);
5413 }
5414 }
5415
5416 /* Pad out the end of the structure. */
5417 if (p->replacement_value.value)
5418 /* If this closes a superfluous brace pair,
5419 just pass out the element between them. */
5420 ret = p->replacement_value;
5421 else if (constructor_type == 0)
5422 ;
5423 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5424 && TREE_CODE (constructor_type) != UNION_TYPE
5425 && TREE_CODE (constructor_type) != ARRAY_TYPE
5426 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5427 {
5428 /* A nonincremental scalar initializer--just return
5429 the element, after verifying there is just one. */
5430 if (VEC_empty (constructor_elt,constructor_elements))
5431 {
5432 if (!constructor_erroneous)
5433 error_init ("empty scalar initializer");
5434 ret.value = error_mark_node;
5435 }
5436 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5437 {
5438 error_init ("extra elements in scalar initializer");
5439 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5440 }
5441 else
5442 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5443 }
5444 else
5445 {
5446 if (constructor_erroneous)
5447 ret.value = error_mark_node;
5448 else
5449 {
5450 ret.value = build_constructor (constructor_type,
5451 constructor_elements);
5452 if (constructor_constant)
5453 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1;
5454 if (constructor_constant && constructor_simple)
5455 TREE_STATIC (ret.value) = 1;
5456 }
5457 }
5458
5459 constructor_type = p->type;
5460 constructor_fields = p->fields;
5461 constructor_index = p->index;
5462 constructor_max_index = p->max_index;
5463 constructor_unfilled_index = p->unfilled_index;
5464 constructor_unfilled_fields = p->unfilled_fields;
5465 constructor_bit_index = p->bit_index;
5466 constructor_elements = p->elements;
5467 constructor_constant = p->constant;
5468 constructor_simple = p->simple;
5469 constructor_erroneous = p->erroneous;
5470 constructor_incremental = p->incremental;
5471 constructor_designated = p->designated;
5472 constructor_pending_elts = p->pending_elts;
5473 constructor_depth = p->depth;
5474 if (!p->implicit)
5475 constructor_range_stack = p->range_stack;
5476 RESTORE_SPELLING_DEPTH (constructor_depth);
5477
5478 constructor_stack = p->next;
5479 free (p);
5480
5481 if (ret.value == 0 && constructor_stack == 0)
5482 ret.value = error_mark_node;
5483 return ret;
5484 }
5485
5486 /* Common handling for both array range and field name designators.
5487 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5488
5489 static int
5490 set_designator (int array)
5491 {
5492 tree subtype;
5493 enum tree_code subcode;
5494
5495 /* Don't die if an entire brace-pair level is superfluous
5496 in the containing level. */
5497 if (constructor_type == 0)
5498 return 1;
5499
5500 /* If there were errors in this designator list already, bail out
5501 silently. */
5502 if (designator_erroneous)
5503 return 1;
5504
5505 if (!designator_depth)
5506 {
5507 gcc_assert (!constructor_range_stack);
5508
5509 /* Designator list starts at the level of closest explicit
5510 braces. */
5511 while (constructor_stack->implicit)
5512 process_init_element (pop_init_level (1));
5513 constructor_designated = 1;
5514 return 0;
5515 }
5516
5517 switch (TREE_CODE (constructor_type))
5518 {
5519 case RECORD_TYPE:
5520 case UNION_TYPE:
5521 subtype = TREE_TYPE (constructor_fields);
5522 if (subtype != error_mark_node)
5523 subtype = TYPE_MAIN_VARIANT (subtype);
5524 break;
5525 case ARRAY_TYPE:
5526 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5527 break;
5528 default:
5529 gcc_unreachable ();
5530 }
5531
5532 subcode = TREE_CODE (subtype);
5533 if (array && subcode != ARRAY_TYPE)
5534 {
5535 error_init ("array index in non-array initializer");
5536 return 1;
5537 }
5538 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5539 {
5540 error_init ("field name not in record or union initializer");
5541 return 1;
5542 }
5543
5544 constructor_designated = 1;
5545 push_init_level (2);
5546 return 0;
5547 }
5548
5549 /* If there are range designators in designator list, push a new designator
5550 to constructor_range_stack. RANGE_END is end of such stack range or
5551 NULL_TREE if there is no range designator at this level. */
5552
5553 static void
5554 push_range_stack (tree range_end)
5555 {
5556 struct constructor_range_stack *p;
5557
5558 p = GGC_NEW (struct constructor_range_stack);
5559 p->prev = constructor_range_stack;
5560 p->next = 0;
5561 p->fields = constructor_fields;
5562 p->range_start = constructor_index;
5563 p->index = constructor_index;
5564 p->stack = constructor_stack;
5565 p->range_end = range_end;
5566 if (constructor_range_stack)
5567 constructor_range_stack->next = p;
5568 constructor_range_stack = p;
5569 }
5570
5571 /* Within an array initializer, specify the next index to be initialized.
5572 FIRST is that index. If LAST is nonzero, then initialize a range
5573 of indices, running from FIRST through LAST. */
5574
5575 void
5576 set_init_index (tree first, tree last)
5577 {
5578 if (set_designator (1))
5579 return;
5580
5581 designator_erroneous = 1;
5582
5583 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5584 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5585 {
5586 error_init ("array index in initializer not of integer type");
5587 return;
5588 }
5589
5590 if (TREE_CODE (first) != INTEGER_CST)
5591 error_init ("nonconstant array index in initializer");
5592 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5593 error_init ("nonconstant array index in initializer");
5594 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5595 error_init ("array index in non-array initializer");
5596 else if (tree_int_cst_sgn (first) == -1)
5597 error_init ("array index in initializer exceeds array bounds");
5598 else if (constructor_max_index
5599 && tree_int_cst_lt (constructor_max_index, first))
5600 error_init ("array index in initializer exceeds array bounds");
5601 else
5602 {
5603 constructor_index = convert (bitsizetype, first);
5604
5605 if (last)
5606 {
5607 if (tree_int_cst_equal (first, last))
5608 last = 0;
5609 else if (tree_int_cst_lt (last, first))
5610 {
5611 error_init ("empty index range in initializer");
5612 last = 0;
5613 }
5614 else
5615 {
5616 last = convert (bitsizetype, last);
5617 if (constructor_max_index != 0
5618 && tree_int_cst_lt (constructor_max_index, last))
5619 {
5620 error_init ("array index range in initializer exceeds array bounds");
5621 last = 0;
5622 }
5623 }
5624 }
5625
5626 designator_depth++;
5627 designator_erroneous = 0;
5628 if (constructor_range_stack || last)
5629 push_range_stack (last);
5630 }
5631 }
5632
5633 /* Within a struct initializer, specify the next field to be initialized. */
5634
5635 void
5636 set_init_label (tree fieldname)
5637 {
5638 tree tail;
5639
5640 if (set_designator (0))
5641 return;
5642
5643 designator_erroneous = 1;
5644
5645 if (TREE_CODE (constructor_type) != RECORD_TYPE
5646 && TREE_CODE (constructor_type) != UNION_TYPE)
5647 {
5648 error_init ("field name not in record or union initializer");
5649 return;
5650 }
5651
5652 for (tail = TYPE_FIELDS (constructor_type); tail;
5653 tail = TREE_CHAIN (tail))
5654 {
5655 if (DECL_NAME (tail) == fieldname)
5656 break;
5657 }
5658
5659 if (tail == 0)
5660 error ("unknown field %qE specified in initializer", fieldname);
5661 else
5662 {
5663 constructor_fields = tail;
5664 designator_depth++;
5665 designator_erroneous = 0;
5666 if (constructor_range_stack)
5667 push_range_stack (NULL_TREE);
5668 }
5669 }
5670 \f
5671 /* Add a new initializer to the tree of pending initializers. PURPOSE
5672 identifies the initializer, either array index or field in a structure.
5673 VALUE is the value of that index or field. */
5674
5675 static void
5676 add_pending_init (tree purpose, tree value)
5677 {
5678 struct init_node *p, **q, *r;
5679
5680 q = &constructor_pending_elts;
5681 p = 0;
5682
5683 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5684 {
5685 while (*q != 0)
5686 {
5687 p = *q;
5688 if (tree_int_cst_lt (purpose, p->purpose))
5689 q = &p->left;
5690 else if (tree_int_cst_lt (p->purpose, purpose))
5691 q = &p->right;
5692 else
5693 {
5694 if (TREE_SIDE_EFFECTS (p->value))
5695 warning_init ("initialized field with side-effects overwritten");
5696 else if (warn_override_init)
5697 warning_init ("initialized field overwritten");
5698 p->value = value;
5699 return;
5700 }
5701 }
5702 }
5703 else
5704 {
5705 tree bitpos;
5706
5707 bitpos = bit_position (purpose);
5708 while (*q != NULL)
5709 {
5710 p = *q;
5711 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5712 q = &p->left;
5713 else if (p->purpose != purpose)
5714 q = &p->right;
5715 else
5716 {
5717 if (TREE_SIDE_EFFECTS (p->value))
5718 warning_init ("initialized field with side-effects overwritten");
5719 else if (warn_override_init)
5720 warning_init ("initialized field overwritten");
5721 p->value = value;
5722 return;
5723 }
5724 }
5725 }
5726
5727 r = GGC_NEW (struct init_node);
5728 r->purpose = purpose;
5729 r->value = value;
5730
5731 *q = r;
5732 r->parent = p;
5733 r->left = 0;
5734 r->right = 0;
5735 r->balance = 0;
5736
5737 while (p)
5738 {
5739 struct init_node *s;
5740
5741 if (r == p->left)
5742 {
5743 if (p->balance == 0)
5744 p->balance = -1;
5745 else if (p->balance < 0)
5746 {
5747 if (r->balance < 0)
5748 {
5749 /* L rotation. */
5750 p->left = r->right;
5751 if (p->left)
5752 p->left->parent = p;
5753 r->right = p;
5754
5755 p->balance = 0;
5756 r->balance = 0;
5757
5758 s = p->parent;
5759 p->parent = r;
5760 r->parent = s;
5761 if (s)
5762 {
5763 if (s->left == p)
5764 s->left = r;
5765 else
5766 s->right = r;
5767 }
5768 else
5769 constructor_pending_elts = r;
5770 }
5771 else
5772 {
5773 /* LR rotation. */
5774 struct init_node *t = r->right;
5775
5776 r->right = t->left;
5777 if (r->right)
5778 r->right->parent = r;
5779 t->left = r;
5780
5781 p->left = t->right;
5782 if (p->left)
5783 p->left->parent = p;
5784 t->right = p;
5785
5786 p->balance = t->balance < 0;
5787 r->balance = -(t->balance > 0);
5788 t->balance = 0;
5789
5790 s = p->parent;
5791 p->parent = t;
5792 r->parent = t;
5793 t->parent = s;
5794 if (s)
5795 {
5796 if (s->left == p)
5797 s->left = t;
5798 else
5799 s->right = t;
5800 }
5801 else
5802 constructor_pending_elts = t;
5803 }
5804 break;
5805 }
5806 else
5807 {
5808 /* p->balance == +1; growth of left side balances the node. */
5809 p->balance = 0;
5810 break;
5811 }
5812 }
5813 else /* r == p->right */
5814 {
5815 if (p->balance == 0)
5816 /* Growth propagation from right side. */
5817 p->balance++;
5818 else if (p->balance > 0)
5819 {
5820 if (r->balance > 0)
5821 {
5822 /* R rotation. */
5823 p->right = r->left;
5824 if (p->right)
5825 p->right->parent = p;
5826 r->left = p;
5827
5828 p->balance = 0;
5829 r->balance = 0;
5830
5831 s = p->parent;
5832 p->parent = r;
5833 r->parent = s;
5834 if (s)
5835 {
5836 if (s->left == p)
5837 s->left = r;
5838 else
5839 s->right = r;
5840 }
5841 else
5842 constructor_pending_elts = r;
5843 }
5844 else /* r->balance == -1 */
5845 {
5846 /* RL rotation */
5847 struct init_node *t = r->left;
5848
5849 r->left = t->right;
5850 if (r->left)
5851 r->left->parent = r;
5852 t->right = r;
5853
5854 p->right = t->left;
5855 if (p->right)
5856 p->right->parent = p;
5857 t->left = p;
5858
5859 r->balance = (t->balance < 0);
5860 p->balance = -(t->balance > 0);
5861 t->balance = 0;
5862
5863 s = p->parent;
5864 p->parent = t;
5865 r->parent = t;
5866 t->parent = s;
5867 if (s)
5868 {
5869 if (s->left == p)
5870 s->left = t;
5871 else
5872 s->right = t;
5873 }
5874 else
5875 constructor_pending_elts = t;
5876 }
5877 break;
5878 }
5879 else
5880 {
5881 /* p->balance == -1; growth of right side balances the node. */
5882 p->balance = 0;
5883 break;
5884 }
5885 }
5886
5887 r = p;
5888 p = p->parent;
5889 }
5890 }
5891
5892 /* Build AVL tree from a sorted chain. */
5893
5894 static void
5895 set_nonincremental_init (void)
5896 {
5897 unsigned HOST_WIDE_INT ix;
5898 tree index, value;
5899
5900 if (TREE_CODE (constructor_type) != RECORD_TYPE
5901 && TREE_CODE (constructor_type) != ARRAY_TYPE)
5902 return;
5903
5904 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
5905 add_pending_init (index, value);
5906 constructor_elements = 0;
5907 if (TREE_CODE (constructor_type) == RECORD_TYPE)
5908 {
5909 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
5910 /* Skip any nameless bit fields at the beginning. */
5911 while (constructor_unfilled_fields != 0
5912 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
5913 && DECL_NAME (constructor_unfilled_fields) == 0)
5914 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5915
5916 }
5917 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5918 {
5919 if (TYPE_DOMAIN (constructor_type))
5920 constructor_unfilled_index
5921 = convert (bitsizetype,
5922 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5923 else
5924 constructor_unfilled_index = bitsize_zero_node;
5925 }
5926 constructor_incremental = 0;
5927 }
5928
5929 /* Build AVL tree from a string constant. */
5930
5931 static void
5932 set_nonincremental_init_from_string (tree str)
5933 {
5934 tree value, purpose, type;
5935 HOST_WIDE_INT val[2];
5936 const char *p, *end;
5937 int byte, wchar_bytes, charwidth, bitpos;
5938
5939 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
5940
5941 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5942 == TYPE_PRECISION (char_type_node))
5943 wchar_bytes = 1;
5944 else
5945 {
5946 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5947 == TYPE_PRECISION (wchar_type_node));
5948 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
5949 }
5950 charwidth = TYPE_PRECISION (char_type_node);
5951 type = TREE_TYPE (constructor_type);
5952 p = TREE_STRING_POINTER (str);
5953 end = p + TREE_STRING_LENGTH (str);
5954
5955 for (purpose = bitsize_zero_node;
5956 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
5957 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
5958 {
5959 if (wchar_bytes == 1)
5960 {
5961 val[1] = (unsigned char) *p++;
5962 val[0] = 0;
5963 }
5964 else
5965 {
5966 val[0] = 0;
5967 val[1] = 0;
5968 for (byte = 0; byte < wchar_bytes; byte++)
5969 {
5970 if (BYTES_BIG_ENDIAN)
5971 bitpos = (wchar_bytes - byte - 1) * charwidth;
5972 else
5973 bitpos = byte * charwidth;
5974 val[bitpos < HOST_BITS_PER_WIDE_INT]
5975 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
5976 << (bitpos % HOST_BITS_PER_WIDE_INT);
5977 }
5978 }
5979
5980 if (!TYPE_UNSIGNED (type))
5981 {
5982 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
5983 if (bitpos < HOST_BITS_PER_WIDE_INT)
5984 {
5985 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
5986 {
5987 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
5988 val[0] = -1;
5989 }
5990 }
5991 else if (bitpos == HOST_BITS_PER_WIDE_INT)
5992 {
5993 if (val[1] < 0)
5994 val[0] = -1;
5995 }
5996 else if (val[0] & (((HOST_WIDE_INT) 1)
5997 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
5998 val[0] |= ((HOST_WIDE_INT) -1)
5999 << (bitpos - HOST_BITS_PER_WIDE_INT);
6000 }
6001
6002 value = build_int_cst_wide (type, val[1], val[0]);
6003 add_pending_init (purpose, value);
6004 }
6005
6006 constructor_incremental = 0;
6007 }
6008
6009 /* Return value of FIELD in pending initializer or zero if the field was
6010 not initialized yet. */
6011
6012 static tree
6013 find_init_member (tree field)
6014 {
6015 struct init_node *p;
6016
6017 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6018 {
6019 if (constructor_incremental
6020 && tree_int_cst_lt (field, constructor_unfilled_index))
6021 set_nonincremental_init ();
6022
6023 p = constructor_pending_elts;
6024 while (p)
6025 {
6026 if (tree_int_cst_lt (field, p->purpose))
6027 p = p->left;
6028 else if (tree_int_cst_lt (p->purpose, field))
6029 p = p->right;
6030 else
6031 return p->value;
6032 }
6033 }
6034 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6035 {
6036 tree bitpos = bit_position (field);
6037
6038 if (constructor_incremental
6039 && (!constructor_unfilled_fields
6040 || tree_int_cst_lt (bitpos,
6041 bit_position (constructor_unfilled_fields))))
6042 set_nonincremental_init ();
6043
6044 p = constructor_pending_elts;
6045 while (p)
6046 {
6047 if (field == p->purpose)
6048 return p->value;
6049 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6050 p = p->left;
6051 else
6052 p = p->right;
6053 }
6054 }
6055 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6056 {
6057 if (!VEC_empty (constructor_elt, constructor_elements)
6058 && (VEC_last (constructor_elt, constructor_elements)->index
6059 == field))
6060 return VEC_last (constructor_elt, constructor_elements)->value;
6061 }
6062 return 0;
6063 }
6064
6065 /* "Output" the next constructor element.
6066 At top level, really output it to assembler code now.
6067 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6068 TYPE is the data type that the containing data type wants here.
6069 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6070 If VALUE is a string constant, STRICT_STRING is true if it is
6071 unparenthesized or we should not warn here for it being parenthesized.
6072 For other types of VALUE, STRICT_STRING is not used.
6073
6074 PENDING if non-nil means output pending elements that belong
6075 right after this element. (PENDING is normally 1;
6076 it is 0 while outputting pending elements, to avoid recursion.) */
6077
6078 static void
6079 output_init_element (tree value, bool strict_string, tree type, tree field,
6080 int pending)
6081 {
6082 constructor_elt *celt;
6083
6084 if (type == error_mark_node || value == error_mark_node)
6085 {
6086 constructor_erroneous = 1;
6087 return;
6088 }
6089 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6090 && (TREE_CODE (value) == STRING_CST
6091 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6092 && !(TREE_CODE (value) == STRING_CST
6093 && TREE_CODE (type) == ARRAY_TYPE
6094 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6095 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6096 TYPE_MAIN_VARIANT (type)))
6097 value = array_to_pointer_conversion (value);
6098
6099 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6100 && require_constant_value && !flag_isoc99 && pending)
6101 {
6102 /* As an extension, allow initializing objects with static storage
6103 duration with compound literals (which are then treated just as
6104 the brace enclosed list they contain). */
6105 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6106 value = DECL_INITIAL (decl);
6107 }
6108
6109 if (value == error_mark_node)
6110 constructor_erroneous = 1;
6111 else if (!TREE_CONSTANT (value))
6112 constructor_constant = 0;
6113 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6114 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6115 || TREE_CODE (constructor_type) == UNION_TYPE)
6116 && DECL_C_BIT_FIELD (field)
6117 && TREE_CODE (value) != INTEGER_CST))
6118 constructor_simple = 0;
6119
6120 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6121 {
6122 if (require_constant_value)
6123 {
6124 error_init ("initializer element is not constant");
6125 value = error_mark_node;
6126 }
6127 else if (require_constant_elements)
6128 pedwarn ("initializer element is not computable at load time");
6129 }
6130
6131 /* If this field is empty (and not at the end of structure),
6132 don't do anything other than checking the initializer. */
6133 if (field
6134 && (TREE_TYPE (field) == error_mark_node
6135 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6136 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6137 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6138 || TREE_CHAIN (field)))))
6139 return;
6140
6141 value = digest_init (type, value, strict_string, require_constant_value);
6142 if (value == error_mark_node)
6143 {
6144 constructor_erroneous = 1;
6145 return;
6146 }
6147
6148 /* If this element doesn't come next in sequence,
6149 put it on constructor_pending_elts. */
6150 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6151 && (!constructor_incremental
6152 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6153 {
6154 if (constructor_incremental
6155 && tree_int_cst_lt (field, constructor_unfilled_index))
6156 set_nonincremental_init ();
6157
6158 add_pending_init (field, value);
6159 return;
6160 }
6161 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6162 && (!constructor_incremental
6163 || field != constructor_unfilled_fields))
6164 {
6165 /* We do this for records but not for unions. In a union,
6166 no matter which field is specified, it can be initialized
6167 right away since it starts at the beginning of the union. */
6168 if (constructor_incremental)
6169 {
6170 if (!constructor_unfilled_fields)
6171 set_nonincremental_init ();
6172 else
6173 {
6174 tree bitpos, unfillpos;
6175
6176 bitpos = bit_position (field);
6177 unfillpos = bit_position (constructor_unfilled_fields);
6178
6179 if (tree_int_cst_lt (bitpos, unfillpos))
6180 set_nonincremental_init ();
6181 }
6182 }
6183
6184 add_pending_init (field, value);
6185 return;
6186 }
6187 else if (TREE_CODE (constructor_type) == UNION_TYPE
6188 && !VEC_empty (constructor_elt, constructor_elements))
6189 {
6190 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6191 constructor_elements)->value))
6192 warning_init ("initialized field with side-effects overwritten");
6193 else if (warn_override_init)
6194 warning_init ("initialized field overwritten");
6195
6196 /* We can have just one union field set. */
6197 constructor_elements = 0;
6198 }
6199
6200 /* Otherwise, output this element either to
6201 constructor_elements or to the assembler file. */
6202
6203 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6204 celt->index = field;
6205 celt->value = value;
6206
6207 /* Advance the variable that indicates sequential elements output. */
6208 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6209 constructor_unfilled_index
6210 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6211 bitsize_one_node);
6212 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6213 {
6214 constructor_unfilled_fields
6215 = TREE_CHAIN (constructor_unfilled_fields);
6216
6217 /* Skip any nameless bit fields. */
6218 while (constructor_unfilled_fields != 0
6219 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6220 && DECL_NAME (constructor_unfilled_fields) == 0)
6221 constructor_unfilled_fields =
6222 TREE_CHAIN (constructor_unfilled_fields);
6223 }
6224 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6225 constructor_unfilled_fields = 0;
6226
6227 /* Now output any pending elements which have become next. */
6228 if (pending)
6229 output_pending_init_elements (0);
6230 }
6231
6232 /* Output any pending elements which have become next.
6233 As we output elements, constructor_unfilled_{fields,index}
6234 advances, which may cause other elements to become next;
6235 if so, they too are output.
6236
6237 If ALL is 0, we return when there are
6238 no more pending elements to output now.
6239
6240 If ALL is 1, we output space as necessary so that
6241 we can output all the pending elements. */
6242
6243 static void
6244 output_pending_init_elements (int all)
6245 {
6246 struct init_node *elt = constructor_pending_elts;
6247 tree next;
6248
6249 retry:
6250
6251 /* Look through the whole pending tree.
6252 If we find an element that should be output now,
6253 output it. Otherwise, set NEXT to the element
6254 that comes first among those still pending. */
6255
6256 next = 0;
6257 while (elt)
6258 {
6259 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6260 {
6261 if (tree_int_cst_equal (elt->purpose,
6262 constructor_unfilled_index))
6263 output_init_element (elt->value, true,
6264 TREE_TYPE (constructor_type),
6265 constructor_unfilled_index, 0);
6266 else if (tree_int_cst_lt (constructor_unfilled_index,
6267 elt->purpose))
6268 {
6269 /* Advance to the next smaller node. */
6270 if (elt->left)
6271 elt = elt->left;
6272 else
6273 {
6274 /* We have reached the smallest node bigger than the
6275 current unfilled index. Fill the space first. */
6276 next = elt->purpose;
6277 break;
6278 }
6279 }
6280 else
6281 {
6282 /* Advance to the next bigger node. */
6283 if (elt->right)
6284 elt = elt->right;
6285 else
6286 {
6287 /* We have reached the biggest node in a subtree. Find
6288 the parent of it, which is the next bigger node. */
6289 while (elt->parent && elt->parent->right == elt)
6290 elt = elt->parent;
6291 elt = elt->parent;
6292 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6293 elt->purpose))
6294 {
6295 next = elt->purpose;
6296 break;
6297 }
6298 }
6299 }
6300 }
6301 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6302 || TREE_CODE (constructor_type) == UNION_TYPE)
6303 {
6304 tree ctor_unfilled_bitpos, elt_bitpos;
6305
6306 /* If the current record is complete we are done. */
6307 if (constructor_unfilled_fields == 0)
6308 break;
6309
6310 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6311 elt_bitpos = bit_position (elt->purpose);
6312 /* We can't compare fields here because there might be empty
6313 fields in between. */
6314 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6315 {
6316 constructor_unfilled_fields = elt->purpose;
6317 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6318 elt->purpose, 0);
6319 }
6320 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6321 {
6322 /* Advance to the next smaller node. */
6323 if (elt->left)
6324 elt = elt->left;
6325 else
6326 {
6327 /* We have reached the smallest node bigger than the
6328 current unfilled field. Fill the space first. */
6329 next = elt->purpose;
6330 break;
6331 }
6332 }
6333 else
6334 {
6335 /* Advance to the next bigger node. */
6336 if (elt->right)
6337 elt = elt->right;
6338 else
6339 {
6340 /* We have reached the biggest node in a subtree. Find
6341 the parent of it, which is the next bigger node. */
6342 while (elt->parent && elt->parent->right == elt)
6343 elt = elt->parent;
6344 elt = elt->parent;
6345 if (elt
6346 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6347 bit_position (elt->purpose))))
6348 {
6349 next = elt->purpose;
6350 break;
6351 }
6352 }
6353 }
6354 }
6355 }
6356
6357 /* Ordinarily return, but not if we want to output all
6358 and there are elements left. */
6359 if (!(all && next != 0))
6360 return;
6361
6362 /* If it's not incremental, just skip over the gap, so that after
6363 jumping to retry we will output the next successive element. */
6364 if (TREE_CODE (constructor_type) == RECORD_TYPE
6365 || TREE_CODE (constructor_type) == UNION_TYPE)
6366 constructor_unfilled_fields = next;
6367 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6368 constructor_unfilled_index = next;
6369
6370 /* ELT now points to the node in the pending tree with the next
6371 initializer to output. */
6372 goto retry;
6373 }
6374 \f
6375 /* Add one non-braced element to the current constructor level.
6376 This adjusts the current position within the constructor's type.
6377 This may also start or terminate implicit levels
6378 to handle a partly-braced initializer.
6379
6380 Once this has found the correct level for the new element,
6381 it calls output_init_element. */
6382
6383 void
6384 process_init_element (struct c_expr value)
6385 {
6386 tree orig_value = value.value;
6387 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6388 bool strict_string = value.original_code == STRING_CST;
6389
6390 designator_depth = 0;
6391 designator_erroneous = 0;
6392
6393 /* Handle superfluous braces around string cst as in
6394 char x[] = {"foo"}; */
6395 if (string_flag
6396 && constructor_type
6397 && TREE_CODE (constructor_type) == ARRAY_TYPE
6398 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6399 && integer_zerop (constructor_unfilled_index))
6400 {
6401 if (constructor_stack->replacement_value.value)
6402 error_init ("excess elements in char array initializer");
6403 constructor_stack->replacement_value = value;
6404 return;
6405 }
6406
6407 if (constructor_stack->replacement_value.value != 0)
6408 {
6409 error_init ("excess elements in struct initializer");
6410 return;
6411 }
6412
6413 /* Ignore elements of a brace group if it is entirely superfluous
6414 and has already been diagnosed. */
6415 if (constructor_type == 0)
6416 return;
6417
6418 /* If we've exhausted any levels that didn't have braces,
6419 pop them now. */
6420 while (constructor_stack->implicit)
6421 {
6422 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6423 || TREE_CODE (constructor_type) == UNION_TYPE)
6424 && constructor_fields == 0)
6425 process_init_element (pop_init_level (1));
6426 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6427 && (constructor_max_index == 0
6428 || tree_int_cst_lt (constructor_max_index,
6429 constructor_index)))
6430 process_init_element (pop_init_level (1));
6431 else
6432 break;
6433 }
6434
6435 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6436 if (constructor_range_stack)
6437 {
6438 /* If value is a compound literal and we'll be just using its
6439 content, don't put it into a SAVE_EXPR. */
6440 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6441 || !require_constant_value
6442 || flag_isoc99)
6443 value.value = save_expr (value.value);
6444 }
6445
6446 while (1)
6447 {
6448 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6449 {
6450 tree fieldtype;
6451 enum tree_code fieldcode;
6452
6453 if (constructor_fields == 0)
6454 {
6455 pedwarn_init ("excess elements in struct initializer");
6456 break;
6457 }
6458
6459 fieldtype = TREE_TYPE (constructor_fields);
6460 if (fieldtype != error_mark_node)
6461 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6462 fieldcode = TREE_CODE (fieldtype);
6463
6464 /* Error for non-static initialization of a flexible array member. */
6465 if (fieldcode == ARRAY_TYPE
6466 && !require_constant_value
6467 && TYPE_SIZE (fieldtype) == NULL_TREE
6468 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6469 {
6470 error_init ("non-static initialization of a flexible array member");
6471 break;
6472 }
6473
6474 /* Accept a string constant to initialize a subarray. */
6475 if (value.value != 0
6476 && fieldcode == ARRAY_TYPE
6477 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6478 && string_flag)
6479 value.value = orig_value;
6480 /* Otherwise, if we have come to a subaggregate,
6481 and we don't have an element of its type, push into it. */
6482 else if (value.value != 0
6483 && value.value != error_mark_node
6484 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6485 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6486 || fieldcode == UNION_TYPE))
6487 {
6488 push_init_level (1);
6489 continue;
6490 }
6491
6492 if (value.value)
6493 {
6494 push_member_name (constructor_fields);
6495 output_init_element (value.value, strict_string,
6496 fieldtype, constructor_fields, 1);
6497 RESTORE_SPELLING_DEPTH (constructor_depth);
6498 }
6499 else
6500 /* Do the bookkeeping for an element that was
6501 directly output as a constructor. */
6502 {
6503 /* For a record, keep track of end position of last field. */
6504 if (DECL_SIZE (constructor_fields))
6505 constructor_bit_index
6506 = size_binop (PLUS_EXPR,
6507 bit_position (constructor_fields),
6508 DECL_SIZE (constructor_fields));
6509
6510 /* If the current field was the first one not yet written out,
6511 it isn't now, so update. */
6512 if (constructor_unfilled_fields == constructor_fields)
6513 {
6514 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6515 /* Skip any nameless bit fields. */
6516 while (constructor_unfilled_fields != 0
6517 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6518 && DECL_NAME (constructor_unfilled_fields) == 0)
6519 constructor_unfilled_fields =
6520 TREE_CHAIN (constructor_unfilled_fields);
6521 }
6522 }
6523
6524 constructor_fields = TREE_CHAIN (constructor_fields);
6525 /* Skip any nameless bit fields at the beginning. */
6526 while (constructor_fields != 0
6527 && DECL_C_BIT_FIELD (constructor_fields)
6528 && DECL_NAME (constructor_fields) == 0)
6529 constructor_fields = TREE_CHAIN (constructor_fields);
6530 }
6531 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6532 {
6533 tree fieldtype;
6534 enum tree_code fieldcode;
6535
6536 if (constructor_fields == 0)
6537 {
6538 pedwarn_init ("excess elements in union initializer");
6539 break;
6540 }
6541
6542 fieldtype = TREE_TYPE (constructor_fields);
6543 if (fieldtype != error_mark_node)
6544 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6545 fieldcode = TREE_CODE (fieldtype);
6546
6547 /* Warn that traditional C rejects initialization of unions.
6548 We skip the warning if the value is zero. This is done
6549 under the assumption that the zero initializer in user
6550 code appears conditioned on e.g. __STDC__ to avoid
6551 "missing initializer" warnings and relies on default
6552 initialization to zero in the traditional C case.
6553 We also skip the warning if the initializer is designated,
6554 again on the assumption that this must be conditional on
6555 __STDC__ anyway (and we've already complained about the
6556 member-designator already). */
6557 if (!in_system_header && !constructor_designated
6558 && !(value.value && (integer_zerop (value.value)
6559 || real_zerop (value.value))))
6560 warning (OPT_Wtraditional, "traditional C rejects initialization "
6561 "of unions");
6562
6563 /* Accept a string constant to initialize a subarray. */
6564 if (value.value != 0
6565 && fieldcode == ARRAY_TYPE
6566 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6567 && string_flag)
6568 value.value = orig_value;
6569 /* Otherwise, if we have come to a subaggregate,
6570 and we don't have an element of its type, push into it. */
6571 else if (value.value != 0
6572 && value.value != error_mark_node
6573 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6574 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6575 || fieldcode == UNION_TYPE))
6576 {
6577 push_init_level (1);
6578 continue;
6579 }
6580
6581 if (value.value)
6582 {
6583 push_member_name (constructor_fields);
6584 output_init_element (value.value, strict_string,
6585 fieldtype, constructor_fields, 1);
6586 RESTORE_SPELLING_DEPTH (constructor_depth);
6587 }
6588 else
6589 /* Do the bookkeeping for an element that was
6590 directly output as a constructor. */
6591 {
6592 constructor_bit_index = DECL_SIZE (constructor_fields);
6593 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6594 }
6595
6596 constructor_fields = 0;
6597 }
6598 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6599 {
6600 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6601 enum tree_code eltcode = TREE_CODE (elttype);
6602
6603 /* Accept a string constant to initialize a subarray. */
6604 if (value.value != 0
6605 && eltcode == ARRAY_TYPE
6606 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6607 && string_flag)
6608 value.value = orig_value;
6609 /* Otherwise, if we have come to a subaggregate,
6610 and we don't have an element of its type, push into it. */
6611 else if (value.value != 0
6612 && value.value != error_mark_node
6613 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6614 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6615 || eltcode == UNION_TYPE))
6616 {
6617 push_init_level (1);
6618 continue;
6619 }
6620
6621 if (constructor_max_index != 0
6622 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6623 || integer_all_onesp (constructor_max_index)))
6624 {
6625 pedwarn_init ("excess elements in array initializer");
6626 break;
6627 }
6628
6629 /* Now output the actual element. */
6630 if (value.value)
6631 {
6632 push_array_bounds (tree_low_cst (constructor_index, 1));
6633 output_init_element (value.value, strict_string,
6634 elttype, constructor_index, 1);
6635 RESTORE_SPELLING_DEPTH (constructor_depth);
6636 }
6637
6638 constructor_index
6639 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6640
6641 if (!value.value)
6642 /* If we are doing the bookkeeping for an element that was
6643 directly output as a constructor, we must update
6644 constructor_unfilled_index. */
6645 constructor_unfilled_index = constructor_index;
6646 }
6647 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6648 {
6649 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6650
6651 /* Do a basic check of initializer size. Note that vectors
6652 always have a fixed size derived from their type. */
6653 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6654 {
6655 pedwarn_init ("excess elements in vector initializer");
6656 break;
6657 }
6658
6659 /* Now output the actual element. */
6660 if (value.value)
6661 output_init_element (value.value, strict_string,
6662 elttype, constructor_index, 1);
6663
6664 constructor_index
6665 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6666
6667 if (!value.value)
6668 /* If we are doing the bookkeeping for an element that was
6669 directly output as a constructor, we must update
6670 constructor_unfilled_index. */
6671 constructor_unfilled_index = constructor_index;
6672 }
6673
6674 /* Handle the sole element allowed in a braced initializer
6675 for a scalar variable. */
6676 else if (constructor_type != error_mark_node
6677 && constructor_fields == 0)
6678 {
6679 pedwarn_init ("excess elements in scalar initializer");
6680 break;
6681 }
6682 else
6683 {
6684 if (value.value)
6685 output_init_element (value.value, strict_string,
6686 constructor_type, NULL_TREE, 1);
6687 constructor_fields = 0;
6688 }
6689
6690 /* Handle range initializers either at this level or anywhere higher
6691 in the designator stack. */
6692 if (constructor_range_stack)
6693 {
6694 struct constructor_range_stack *p, *range_stack;
6695 int finish = 0;
6696
6697 range_stack = constructor_range_stack;
6698 constructor_range_stack = 0;
6699 while (constructor_stack != range_stack->stack)
6700 {
6701 gcc_assert (constructor_stack->implicit);
6702 process_init_element (pop_init_level (1));
6703 }
6704 for (p = range_stack;
6705 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6706 p = p->prev)
6707 {
6708 gcc_assert (constructor_stack->implicit);
6709 process_init_element (pop_init_level (1));
6710 }
6711
6712 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6713 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6714 finish = 1;
6715
6716 while (1)
6717 {
6718 constructor_index = p->index;
6719 constructor_fields = p->fields;
6720 if (finish && p->range_end && p->index == p->range_start)
6721 {
6722 finish = 0;
6723 p->prev = 0;
6724 }
6725 p = p->next;
6726 if (!p)
6727 break;
6728 push_init_level (2);
6729 p->stack = constructor_stack;
6730 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6731 p->index = p->range_start;
6732 }
6733
6734 if (!finish)
6735 constructor_range_stack = range_stack;
6736 continue;
6737 }
6738
6739 break;
6740 }
6741
6742 constructor_range_stack = 0;
6743 }
6744 \f
6745 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6746 (guaranteed to be 'volatile' or null) and ARGS (represented using
6747 an ASM_EXPR node). */
6748 tree
6749 build_asm_stmt (tree cv_qualifier, tree args)
6750 {
6751 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6752 ASM_VOLATILE_P (args) = 1;
6753 return add_stmt (args);
6754 }
6755
6756 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6757 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6758 SIMPLE indicates whether there was anything at all after the
6759 string in the asm expression -- asm("blah") and asm("blah" : )
6760 are subtly different. We use a ASM_EXPR node to represent this. */
6761 tree
6762 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6763 bool simple)
6764 {
6765 tree tail;
6766 tree args;
6767 int i;
6768 const char *constraint;
6769 const char **oconstraints;
6770 bool allows_mem, allows_reg, is_inout;
6771 int ninputs, noutputs;
6772
6773 ninputs = list_length (inputs);
6774 noutputs = list_length (outputs);
6775 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6776
6777 string = resolve_asm_operand_names (string, outputs, inputs);
6778
6779 /* Remove output conversions that change the type but not the mode. */
6780 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6781 {
6782 tree output = TREE_VALUE (tail);
6783
6784 /* ??? Really, this should not be here. Users should be using a
6785 proper lvalue, dammit. But there's a long history of using casts
6786 in the output operands. In cases like longlong.h, this becomes a
6787 primitive form of typechecking -- if the cast can be removed, then
6788 the output operand had a type of the proper width; otherwise we'll
6789 get an error. Gross, but ... */
6790 STRIP_NOPS (output);
6791
6792 if (!lvalue_or_else (output, lv_asm))
6793 output = error_mark_node;
6794
6795 if (output != error_mark_node
6796 && (TREE_READONLY (output)
6797 || TYPE_READONLY (TREE_TYPE (output))
6798 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6799 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6800 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6801 readonly_error (output, lv_asm);
6802
6803 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6804 oconstraints[i] = constraint;
6805
6806 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6807 &allows_mem, &allows_reg, &is_inout))
6808 {
6809 /* If the operand is going to end up in memory,
6810 mark it addressable. */
6811 if (!allows_reg && !c_mark_addressable (output))
6812 output = error_mark_node;
6813 }
6814 else
6815 output = error_mark_node;
6816
6817 TREE_VALUE (tail) = output;
6818 }
6819
6820 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
6821 {
6822 tree input;
6823
6824 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6825 input = TREE_VALUE (tail);
6826
6827 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
6828 oconstraints, &allows_mem, &allows_reg))
6829 {
6830 /* If the operand is going to end up in memory,
6831 mark it addressable. */
6832 if (!allows_reg && allows_mem)
6833 {
6834 /* Strip the nops as we allow this case. FIXME, this really
6835 should be rejected or made deprecated. */
6836 STRIP_NOPS (input);
6837 if (!c_mark_addressable (input))
6838 input = error_mark_node;
6839 }
6840 }
6841 else
6842 input = error_mark_node;
6843
6844 TREE_VALUE (tail) = input;
6845 }
6846
6847 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
6848
6849 /* asm statements without outputs, including simple ones, are treated
6850 as volatile. */
6851 ASM_INPUT_P (args) = simple;
6852 ASM_VOLATILE_P (args) = (noutputs == 0);
6853
6854 return args;
6855 }
6856 \f
6857 /* Generate a goto statement to LABEL. */
6858
6859 tree
6860 c_finish_goto_label (tree label)
6861 {
6862 tree decl = lookup_label (label);
6863 if (!decl)
6864 return NULL_TREE;
6865
6866 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
6867 {
6868 error ("jump into statement expression");
6869 return NULL_TREE;
6870 }
6871
6872 if (C_DECL_UNJUMPABLE_VM (decl))
6873 {
6874 error ("jump into scope of identifier with variably modified type");
6875 return NULL_TREE;
6876 }
6877
6878 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
6879 {
6880 /* No jump from outside this statement expression context, so
6881 record that there is a jump from within this context. */
6882 struct c_label_list *nlist;
6883 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6884 nlist->next = label_context_stack_se->labels_used;
6885 nlist->label = decl;
6886 label_context_stack_se->labels_used = nlist;
6887 }
6888
6889 if (!C_DECL_UNDEFINABLE_VM (decl))
6890 {
6891 /* No jump from outside this context context of identifiers with
6892 variably modified type, so record that there is a jump from
6893 within this context. */
6894 struct c_label_list *nlist;
6895 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6896 nlist->next = label_context_stack_vm->labels_used;
6897 nlist->label = decl;
6898 label_context_stack_vm->labels_used = nlist;
6899 }
6900
6901 TREE_USED (decl) = 1;
6902 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
6903 }
6904
6905 /* Generate a computed goto statement to EXPR. */
6906
6907 tree
6908 c_finish_goto_ptr (tree expr)
6909 {
6910 if (pedantic)
6911 pedwarn ("ISO C forbids %<goto *expr;%>");
6912 expr = convert (ptr_type_node, expr);
6913 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
6914 }
6915
6916 /* Generate a C `return' statement. RETVAL is the expression for what
6917 to return, or a null pointer for `return;' with no value. */
6918
6919 tree
6920 c_finish_return (tree retval)
6921 {
6922 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
6923 bool no_warning = false;
6924
6925 if (TREE_THIS_VOLATILE (current_function_decl))
6926 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6927
6928 if (!retval)
6929 {
6930 current_function_returns_null = 1;
6931 if ((warn_return_type || flag_isoc99)
6932 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
6933 {
6934 pedwarn_c99 ("%<return%> with no value, in "
6935 "function returning non-void");
6936 no_warning = true;
6937 }
6938 }
6939 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
6940 {
6941 current_function_returns_null = 1;
6942 if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
6943 pedwarn ("%<return%> with a value, in function returning void");
6944 else if (pedantic)
6945 pedwarn ("ISO C forbids %<return%> with expression, in function returning void");
6946 }
6947 else
6948 {
6949 tree t = convert_for_assignment (valtype, retval, ic_return,
6950 NULL_TREE, NULL_TREE, 0);
6951 tree res = DECL_RESULT (current_function_decl);
6952 tree inner;
6953
6954 current_function_returns_value = 1;
6955 if (t == error_mark_node)
6956 return NULL_TREE;
6957
6958 inner = t = convert (TREE_TYPE (res), t);
6959
6960 /* Strip any conversions, additions, and subtractions, and see if
6961 we are returning the address of a local variable. Warn if so. */
6962 while (1)
6963 {
6964 switch (TREE_CODE (inner))
6965 {
6966 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
6967 case PLUS_EXPR:
6968 inner = TREE_OPERAND (inner, 0);
6969 continue;
6970
6971 case MINUS_EXPR:
6972 /* If the second operand of the MINUS_EXPR has a pointer
6973 type (or is converted from it), this may be valid, so
6974 don't give a warning. */
6975 {
6976 tree op1 = TREE_OPERAND (inner, 1);
6977
6978 while (!POINTER_TYPE_P (TREE_TYPE (op1))
6979 && (TREE_CODE (op1) == NOP_EXPR
6980 || TREE_CODE (op1) == NON_LVALUE_EXPR
6981 || TREE_CODE (op1) == CONVERT_EXPR))
6982 op1 = TREE_OPERAND (op1, 0);
6983
6984 if (POINTER_TYPE_P (TREE_TYPE (op1)))
6985 break;
6986
6987 inner = TREE_OPERAND (inner, 0);
6988 continue;
6989 }
6990
6991 case ADDR_EXPR:
6992 inner = TREE_OPERAND (inner, 0);
6993
6994 while (REFERENCE_CLASS_P (inner)
6995 && TREE_CODE (inner) != INDIRECT_REF)
6996 inner = TREE_OPERAND (inner, 0);
6997
6998 if (DECL_P (inner)
6999 && !DECL_EXTERNAL (inner)
7000 && !TREE_STATIC (inner)
7001 && DECL_CONTEXT (inner) == current_function_decl)
7002 warning (0, "function returns address of local variable");
7003 break;
7004
7005 default:
7006 break;
7007 }
7008
7009 break;
7010 }
7011
7012 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7013 }
7014
7015 ret_stmt = build_stmt (RETURN_EXPR, retval);
7016 TREE_NO_WARNING (ret_stmt) |= no_warning;
7017 return add_stmt (ret_stmt);
7018 }
7019 \f
7020 struct c_switch {
7021 /* The SWITCH_EXPR being built. */
7022 tree switch_expr;
7023
7024 /* The original type of the testing expression, i.e. before the
7025 default conversion is applied. */
7026 tree orig_type;
7027
7028 /* A splay-tree mapping the low element of a case range to the high
7029 element, or NULL_TREE if there is no high element. Used to
7030 determine whether or not a new case label duplicates an old case
7031 label. We need a tree, rather than simply a hash table, because
7032 of the GNU case range extension. */
7033 splay_tree cases;
7034
7035 /* Number of nested statement expressions within this switch
7036 statement; if nonzero, case and default labels may not
7037 appear. */
7038 unsigned int blocked_stmt_expr;
7039
7040 /* Scope of outermost declarations of identifiers with variably
7041 modified type within this switch statement; if nonzero, case and
7042 default labels may not appear. */
7043 unsigned int blocked_vm;
7044
7045 /* The next node on the stack. */
7046 struct c_switch *next;
7047 };
7048
7049 /* A stack of the currently active switch statements. The innermost
7050 switch statement is on the top of the stack. There is no need to
7051 mark the stack for garbage collection because it is only active
7052 during the processing of the body of a function, and we never
7053 collect at that point. */
7054
7055 struct c_switch *c_switch_stack;
7056
7057 /* Start a C switch statement, testing expression EXP. Return the new
7058 SWITCH_EXPR. */
7059
7060 tree
7061 c_start_case (tree exp)
7062 {
7063 tree orig_type = error_mark_node;
7064 struct c_switch *cs;
7065
7066 if (exp != error_mark_node)
7067 {
7068 orig_type = TREE_TYPE (exp);
7069
7070 if (!INTEGRAL_TYPE_P (orig_type))
7071 {
7072 if (orig_type != error_mark_node)
7073 {
7074 error ("switch quantity not an integer");
7075 orig_type = error_mark_node;
7076 }
7077 exp = integer_zero_node;
7078 }
7079 else
7080 {
7081 tree type = TYPE_MAIN_VARIANT (orig_type);
7082
7083 if (!in_system_header
7084 && (type == long_integer_type_node
7085 || type == long_unsigned_type_node))
7086 warning (OPT_Wtraditional, "%<long%> switch expression not "
7087 "converted to %<int%> in ISO C");
7088
7089 exp = default_conversion (exp);
7090 }
7091 }
7092
7093 /* Add this new SWITCH_EXPR to the stack. */
7094 cs = XNEW (struct c_switch);
7095 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7096 cs->orig_type = orig_type;
7097 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7098 cs->blocked_stmt_expr = 0;
7099 cs->blocked_vm = 0;
7100 cs->next = c_switch_stack;
7101 c_switch_stack = cs;
7102
7103 return add_stmt (cs->switch_expr);
7104 }
7105
7106 /* Process a case label. */
7107
7108 tree
7109 do_case (tree low_value, tree high_value)
7110 {
7111 tree label = NULL_TREE;
7112
7113 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7114 && !c_switch_stack->blocked_vm)
7115 {
7116 label = c_add_case_label (c_switch_stack->cases,
7117 SWITCH_COND (c_switch_stack->switch_expr),
7118 c_switch_stack->orig_type,
7119 low_value, high_value);
7120 if (label == error_mark_node)
7121 label = NULL_TREE;
7122 }
7123 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7124 {
7125 if (low_value)
7126 error ("case label in statement expression not containing "
7127 "enclosing switch statement");
7128 else
7129 error ("%<default%> label in statement expression not containing "
7130 "enclosing switch statement");
7131 }
7132 else if (c_switch_stack && c_switch_stack->blocked_vm)
7133 {
7134 if (low_value)
7135 error ("case label in scope of identifier with variably modified "
7136 "type not containing enclosing switch statement");
7137 else
7138 error ("%<default%> label in scope of identifier with variably "
7139 "modified type not containing enclosing switch statement");
7140 }
7141 else if (low_value)
7142 error ("case label not within a switch statement");
7143 else
7144 error ("%<default%> label not within a switch statement");
7145
7146 return label;
7147 }
7148
7149 /* Finish the switch statement. */
7150
7151 void
7152 c_finish_case (tree body)
7153 {
7154 struct c_switch *cs = c_switch_stack;
7155 location_t switch_location;
7156
7157 SWITCH_BODY (cs->switch_expr) = body;
7158
7159 /* We must not be within a statement expression nested in the switch
7160 at this point; we might, however, be within the scope of an
7161 identifier with variably modified type nested in the switch. */
7162 gcc_assert (!cs->blocked_stmt_expr);
7163
7164 /* Emit warnings as needed. */
7165 if (EXPR_HAS_LOCATION (cs->switch_expr))
7166 switch_location = EXPR_LOCATION (cs->switch_expr);
7167 else
7168 switch_location = input_location;
7169 c_do_switch_warnings (cs->cases, switch_location,
7170 TREE_TYPE (cs->switch_expr),
7171 SWITCH_COND (cs->switch_expr));
7172
7173 /* Pop the stack. */
7174 c_switch_stack = cs->next;
7175 splay_tree_delete (cs->cases);
7176 XDELETE (cs);
7177 }
7178 \f
7179 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7180 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7181 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7182 statement, and was not surrounded with parenthesis. */
7183
7184 void
7185 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7186 tree else_block, bool nested_if)
7187 {
7188 tree stmt;
7189
7190 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7191 if (warn_parentheses && nested_if && else_block == NULL)
7192 {
7193 tree inner_if = then_block;
7194
7195 /* We know from the grammar productions that there is an IF nested
7196 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7197 it might not be exactly THEN_BLOCK, but should be the last
7198 non-container statement within. */
7199 while (1)
7200 switch (TREE_CODE (inner_if))
7201 {
7202 case COND_EXPR:
7203 goto found;
7204 case BIND_EXPR:
7205 inner_if = BIND_EXPR_BODY (inner_if);
7206 break;
7207 case STATEMENT_LIST:
7208 inner_if = expr_last (then_block);
7209 break;
7210 case TRY_FINALLY_EXPR:
7211 case TRY_CATCH_EXPR:
7212 inner_if = TREE_OPERAND (inner_if, 0);
7213 break;
7214 default:
7215 gcc_unreachable ();
7216 }
7217 found:
7218
7219 if (COND_EXPR_ELSE (inner_if))
7220 warning (OPT_Wparentheses,
7221 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7222 &if_locus);
7223 }
7224
7225 empty_body_warning (then_block, else_block);
7226
7227 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7228 SET_EXPR_LOCATION (stmt, if_locus);
7229 add_stmt (stmt);
7230 }
7231
7232 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7233 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7234 is false for DO loops. INCR is the FOR increment expression. BODY is
7235 the statement controlled by the loop. BLAB is the break label. CLAB is
7236 the continue label. Everything is allowed to be NULL. */
7237
7238 void
7239 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7240 tree blab, tree clab, bool cond_is_first)
7241 {
7242 tree entry = NULL, exit = NULL, t;
7243
7244 /* If the condition is zero don't generate a loop construct. */
7245 if (cond && integer_zerop (cond))
7246 {
7247 if (cond_is_first)
7248 {
7249 t = build_and_jump (&blab);
7250 SET_EXPR_LOCATION (t, start_locus);
7251 add_stmt (t);
7252 }
7253 }
7254 else
7255 {
7256 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7257
7258 /* If we have an exit condition, then we build an IF with gotos either
7259 out of the loop, or to the top of it. If there's no exit condition,
7260 then we just build a jump back to the top. */
7261 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7262
7263 if (cond && !integer_nonzerop (cond))
7264 {
7265 /* Canonicalize the loop condition to the end. This means
7266 generating a branch to the loop condition. Reuse the
7267 continue label, if possible. */
7268 if (cond_is_first)
7269 {
7270 if (incr || !clab)
7271 {
7272 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7273 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7274 }
7275 else
7276 t = build1 (GOTO_EXPR, void_type_node, clab);
7277 SET_EXPR_LOCATION (t, start_locus);
7278 add_stmt (t);
7279 }
7280
7281 t = build_and_jump (&blab);
7282 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7283 if (cond_is_first)
7284 SET_EXPR_LOCATION (exit, start_locus);
7285 else
7286 SET_EXPR_LOCATION (exit, input_location);
7287 }
7288
7289 add_stmt (top);
7290 }
7291
7292 if (body)
7293 add_stmt (body);
7294 if (clab)
7295 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7296 if (incr)
7297 add_stmt (incr);
7298 if (entry)
7299 add_stmt (entry);
7300 if (exit)
7301 add_stmt (exit);
7302 if (blab)
7303 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7304 }
7305
7306 tree
7307 c_finish_bc_stmt (tree *label_p, bool is_break)
7308 {
7309 bool skip;
7310 tree label = *label_p;
7311
7312 /* In switch statements break is sometimes stylistically used after
7313 a return statement. This can lead to spurious warnings about
7314 control reaching the end of a non-void function when it is
7315 inlined. Note that we are calling block_may_fallthru with
7316 language specific tree nodes; this works because
7317 block_may_fallthru returns true when given something it does not
7318 understand. */
7319 skip = !block_may_fallthru (cur_stmt_list);
7320
7321 if (!label)
7322 {
7323 if (!skip)
7324 *label_p = label = create_artificial_label ();
7325 }
7326 else if (TREE_CODE (label) == LABEL_DECL)
7327 ;
7328 else switch (TREE_INT_CST_LOW (label))
7329 {
7330 case 0:
7331 if (is_break)
7332 error ("break statement not within loop or switch");
7333 else
7334 error ("continue statement not within a loop");
7335 return NULL_TREE;
7336
7337 case 1:
7338 gcc_assert (is_break);
7339 error ("break statement used with OpenMP for loop");
7340 return NULL_TREE;
7341
7342 default:
7343 gcc_unreachable ();
7344 }
7345
7346 if (skip)
7347 return NULL_TREE;
7348
7349 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7350 }
7351
7352 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7353
7354 static void
7355 emit_side_effect_warnings (tree expr)
7356 {
7357 if (expr == error_mark_node)
7358 ;
7359 else if (!TREE_SIDE_EFFECTS (expr))
7360 {
7361 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7362 warning (OPT_Wunused_value, "%Hstatement with no effect",
7363 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7364 }
7365 else
7366 warn_if_unused_value (expr, input_location);
7367 }
7368
7369 /* Process an expression as if it were a complete statement. Emit
7370 diagnostics, but do not call ADD_STMT. */
7371
7372 tree
7373 c_process_expr_stmt (tree expr)
7374 {
7375 if (!expr)
7376 return NULL_TREE;
7377
7378 if (warn_sequence_point)
7379 verify_sequence_points (expr);
7380
7381 if (TREE_TYPE (expr) != error_mark_node
7382 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7383 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7384 error ("expression statement has incomplete type");
7385
7386 /* If we're not processing a statement expression, warn about unused values.
7387 Warnings for statement expressions will be emitted later, once we figure
7388 out which is the result. */
7389 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7390 && warn_unused_value)
7391 emit_side_effect_warnings (expr);
7392
7393 /* If the expression is not of a type to which we cannot assign a line
7394 number, wrap the thing in a no-op NOP_EXPR. */
7395 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7396 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7397
7398 if (CAN_HAVE_LOCATION_P (expr))
7399 SET_EXPR_LOCATION (expr, input_location);
7400
7401 return expr;
7402 }
7403
7404 /* Emit an expression as a statement. */
7405
7406 tree
7407 c_finish_expr_stmt (tree expr)
7408 {
7409 if (expr)
7410 return add_stmt (c_process_expr_stmt (expr));
7411 else
7412 return NULL;
7413 }
7414
7415 /* Do the opposite and emit a statement as an expression. To begin,
7416 create a new binding level and return it. */
7417
7418 tree
7419 c_begin_stmt_expr (void)
7420 {
7421 tree ret;
7422 struct c_label_context_se *nstack;
7423 struct c_label_list *glist;
7424
7425 /* We must force a BLOCK for this level so that, if it is not expanded
7426 later, there is a way to turn off the entire subtree of blocks that
7427 are contained in it. */
7428 keep_next_level ();
7429 ret = c_begin_compound_stmt (true);
7430 if (c_switch_stack)
7431 {
7432 c_switch_stack->blocked_stmt_expr++;
7433 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7434 }
7435 for (glist = label_context_stack_se->labels_used;
7436 glist != NULL;
7437 glist = glist->next)
7438 {
7439 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7440 }
7441 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7442 nstack->labels_def = NULL;
7443 nstack->labels_used = NULL;
7444 nstack->next = label_context_stack_se;
7445 label_context_stack_se = nstack;
7446
7447 /* Mark the current statement list as belonging to a statement list. */
7448 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7449
7450 return ret;
7451 }
7452
7453 tree
7454 c_finish_stmt_expr (tree body)
7455 {
7456 tree last, type, tmp, val;
7457 tree *last_p;
7458 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7459
7460 body = c_end_compound_stmt (body, true);
7461 if (c_switch_stack)
7462 {
7463 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7464 c_switch_stack->blocked_stmt_expr--;
7465 }
7466 /* It is no longer possible to jump to labels defined within this
7467 statement expression. */
7468 for (dlist = label_context_stack_se->labels_def;
7469 dlist != NULL;
7470 dlist = dlist->next)
7471 {
7472 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7473 }
7474 /* It is again possible to define labels with a goto just outside
7475 this statement expression. */
7476 for (glist = label_context_stack_se->next->labels_used;
7477 glist != NULL;
7478 glist = glist->next)
7479 {
7480 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7481 glist_prev = glist;
7482 }
7483 if (glist_prev != NULL)
7484 glist_prev->next = label_context_stack_se->labels_used;
7485 else
7486 label_context_stack_se->next->labels_used
7487 = label_context_stack_se->labels_used;
7488 label_context_stack_se = label_context_stack_se->next;
7489
7490 /* Locate the last statement in BODY. See c_end_compound_stmt
7491 about always returning a BIND_EXPR. */
7492 last_p = &BIND_EXPR_BODY (body);
7493 last = BIND_EXPR_BODY (body);
7494
7495 continue_searching:
7496 if (TREE_CODE (last) == STATEMENT_LIST)
7497 {
7498 tree_stmt_iterator i;
7499
7500 /* This can happen with degenerate cases like ({ }). No value. */
7501 if (!TREE_SIDE_EFFECTS (last))
7502 return body;
7503
7504 /* If we're supposed to generate side effects warnings, process
7505 all of the statements except the last. */
7506 if (warn_unused_value)
7507 {
7508 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7509 emit_side_effect_warnings (tsi_stmt (i));
7510 }
7511 else
7512 i = tsi_last (last);
7513 last_p = tsi_stmt_ptr (i);
7514 last = *last_p;
7515 }
7516
7517 /* If the end of the list is exception related, then the list was split
7518 by a call to push_cleanup. Continue searching. */
7519 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7520 || TREE_CODE (last) == TRY_CATCH_EXPR)
7521 {
7522 last_p = &TREE_OPERAND (last, 0);
7523 last = *last_p;
7524 goto continue_searching;
7525 }
7526
7527 /* In the case that the BIND_EXPR is not necessary, return the
7528 expression out from inside it. */
7529 if (last == error_mark_node
7530 || (last == BIND_EXPR_BODY (body)
7531 && BIND_EXPR_VARS (body) == NULL))
7532 {
7533 /* Do not warn if the return value of a statement expression is
7534 unused. */
7535 if (CAN_HAVE_LOCATION_P (last))
7536 TREE_NO_WARNING (last) = 1;
7537 return last;
7538 }
7539
7540 /* Extract the type of said expression. */
7541 type = TREE_TYPE (last);
7542
7543 /* If we're not returning a value at all, then the BIND_EXPR that
7544 we already have is a fine expression to return. */
7545 if (!type || VOID_TYPE_P (type))
7546 return body;
7547
7548 /* Now that we've located the expression containing the value, it seems
7549 silly to make voidify_wrapper_expr repeat the process. Create a
7550 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7551 tmp = create_tmp_var_raw (type, NULL);
7552
7553 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7554 tree_expr_nonnegative_p giving up immediately. */
7555 val = last;
7556 if (TREE_CODE (val) == NOP_EXPR
7557 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7558 val = TREE_OPERAND (val, 0);
7559
7560 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7561 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7562
7563 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7564 }
7565
7566 /* Begin the scope of an identifier of variably modified type, scope
7567 number SCOPE. Jumping from outside this scope to inside it is not
7568 permitted. */
7569
7570 void
7571 c_begin_vm_scope (unsigned int scope)
7572 {
7573 struct c_label_context_vm *nstack;
7574 struct c_label_list *glist;
7575
7576 gcc_assert (scope > 0);
7577
7578 /* At file_scope, we don't have to do any processing. */
7579 if (label_context_stack_vm == NULL)
7580 return;
7581
7582 if (c_switch_stack && !c_switch_stack->blocked_vm)
7583 c_switch_stack->blocked_vm = scope;
7584 for (glist = label_context_stack_vm->labels_used;
7585 glist != NULL;
7586 glist = glist->next)
7587 {
7588 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7589 }
7590 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7591 nstack->labels_def = NULL;
7592 nstack->labels_used = NULL;
7593 nstack->scope = scope;
7594 nstack->next = label_context_stack_vm;
7595 label_context_stack_vm = nstack;
7596 }
7597
7598 /* End a scope which may contain identifiers of variably modified
7599 type, scope number SCOPE. */
7600
7601 void
7602 c_end_vm_scope (unsigned int scope)
7603 {
7604 if (label_context_stack_vm == NULL)
7605 return;
7606 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7607 c_switch_stack->blocked_vm = 0;
7608 /* We may have a number of nested scopes of identifiers with
7609 variably modified type, all at this depth. Pop each in turn. */
7610 while (label_context_stack_vm->scope == scope)
7611 {
7612 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7613
7614 /* It is no longer possible to jump to labels defined within this
7615 scope. */
7616 for (dlist = label_context_stack_vm->labels_def;
7617 dlist != NULL;
7618 dlist = dlist->next)
7619 {
7620 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7621 }
7622 /* It is again possible to define labels with a goto just outside
7623 this scope. */
7624 for (glist = label_context_stack_vm->next->labels_used;
7625 glist != NULL;
7626 glist = glist->next)
7627 {
7628 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7629 glist_prev = glist;
7630 }
7631 if (glist_prev != NULL)
7632 glist_prev->next = label_context_stack_vm->labels_used;
7633 else
7634 label_context_stack_vm->next->labels_used
7635 = label_context_stack_vm->labels_used;
7636 label_context_stack_vm = label_context_stack_vm->next;
7637 }
7638 }
7639 \f
7640 /* Begin and end compound statements. This is as simple as pushing
7641 and popping new statement lists from the tree. */
7642
7643 tree
7644 c_begin_compound_stmt (bool do_scope)
7645 {
7646 tree stmt = push_stmt_list ();
7647 if (do_scope)
7648 push_scope ();
7649 return stmt;
7650 }
7651
7652 tree
7653 c_end_compound_stmt (tree stmt, bool do_scope)
7654 {
7655 tree block = NULL;
7656
7657 if (do_scope)
7658 {
7659 if (c_dialect_objc ())
7660 objc_clear_super_receiver ();
7661 block = pop_scope ();
7662 }
7663
7664 stmt = pop_stmt_list (stmt);
7665 stmt = c_build_bind_expr (block, stmt);
7666
7667 /* If this compound statement is nested immediately inside a statement
7668 expression, then force a BIND_EXPR to be created. Otherwise we'll
7669 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7670 STATEMENT_LISTs merge, and thus we can lose track of what statement
7671 was really last. */
7672 if (cur_stmt_list
7673 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7674 && TREE_CODE (stmt) != BIND_EXPR)
7675 {
7676 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7677 TREE_SIDE_EFFECTS (stmt) = 1;
7678 }
7679
7680 return stmt;
7681 }
7682
7683 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7684 when the current scope is exited. EH_ONLY is true when this is not
7685 meant to apply to normal control flow transfer. */
7686
7687 void
7688 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7689 {
7690 enum tree_code code;
7691 tree stmt, list;
7692 bool stmt_expr;
7693
7694 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7695 stmt = build_stmt (code, NULL, cleanup);
7696 add_stmt (stmt);
7697 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7698 list = push_stmt_list ();
7699 TREE_OPERAND (stmt, 0) = list;
7700 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7701 }
7702 \f
7703 /* Build a binary-operation expression without default conversions.
7704 CODE is the kind of expression to build.
7705 This function differs from `build' in several ways:
7706 the data type of the result is computed and recorded in it,
7707 warnings are generated if arg data types are invalid,
7708 special handling for addition and subtraction of pointers is known,
7709 and some optimization is done (operations on narrow ints
7710 are done in the narrower type when that gives the same result).
7711 Constant folding is also done before the result is returned.
7712
7713 Note that the operands will never have enumeral types, or function
7714 or array types, because either they will have the default conversions
7715 performed or they have both just been converted to some other type in which
7716 the arithmetic is to be done. */
7717
7718 tree
7719 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7720 int convert_p)
7721 {
7722 tree type0, type1;
7723 enum tree_code code0, code1;
7724 tree op0, op1;
7725 const char *invalid_op_diag;
7726
7727 /* Expression code to give to the expression when it is built.
7728 Normally this is CODE, which is what the caller asked for,
7729 but in some special cases we change it. */
7730 enum tree_code resultcode = code;
7731
7732 /* Data type in which the computation is to be performed.
7733 In the simplest cases this is the common type of the arguments. */
7734 tree result_type = NULL;
7735
7736 /* Nonzero means operands have already been type-converted
7737 in whatever way is necessary.
7738 Zero means they need to be converted to RESULT_TYPE. */
7739 int converted = 0;
7740
7741 /* Nonzero means create the expression with this type, rather than
7742 RESULT_TYPE. */
7743 tree build_type = 0;
7744
7745 /* Nonzero means after finally constructing the expression
7746 convert it to this type. */
7747 tree final_type = 0;
7748
7749 /* Nonzero if this is an operation like MIN or MAX which can
7750 safely be computed in short if both args are promoted shorts.
7751 Also implies COMMON.
7752 -1 indicates a bitwise operation; this makes a difference
7753 in the exact conditions for when it is safe to do the operation
7754 in a narrower mode. */
7755 int shorten = 0;
7756
7757 /* Nonzero if this is a comparison operation;
7758 if both args are promoted shorts, compare the original shorts.
7759 Also implies COMMON. */
7760 int short_compare = 0;
7761
7762 /* Nonzero if this is a right-shift operation, which can be computed on the
7763 original short and then promoted if the operand is a promoted short. */
7764 int short_shift = 0;
7765
7766 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7767 int common = 0;
7768
7769 /* True means types are compatible as far as ObjC is concerned. */
7770 bool objc_ok;
7771
7772 if (convert_p)
7773 {
7774 op0 = default_conversion (orig_op0);
7775 op1 = default_conversion (orig_op1);
7776 }
7777 else
7778 {
7779 op0 = orig_op0;
7780 op1 = orig_op1;
7781 }
7782
7783 type0 = TREE_TYPE (op0);
7784 type1 = TREE_TYPE (op1);
7785
7786 /* The expression codes of the data types of the arguments tell us
7787 whether the arguments are integers, floating, pointers, etc. */
7788 code0 = TREE_CODE (type0);
7789 code1 = TREE_CODE (type1);
7790
7791 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7792 STRIP_TYPE_NOPS (op0);
7793 STRIP_TYPE_NOPS (op1);
7794
7795 /* If an error was already reported for one of the arguments,
7796 avoid reporting another error. */
7797
7798 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7799 return error_mark_node;
7800
7801 if ((invalid_op_diag
7802 = targetm.invalid_binary_op (code, type0, type1)))
7803 {
7804 error (invalid_op_diag);
7805 return error_mark_node;
7806 }
7807
7808 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
7809
7810 switch (code)
7811 {
7812 case PLUS_EXPR:
7813 /* Handle the pointer + int case. */
7814 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7815 return pointer_int_sum (PLUS_EXPR, op0, op1);
7816 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
7817 return pointer_int_sum (PLUS_EXPR, op1, op0);
7818 else
7819 common = 1;
7820 break;
7821
7822 case MINUS_EXPR:
7823 /* Subtraction of two similar pointers.
7824 We must subtract them as integers, then divide by object size. */
7825 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
7826 && comp_target_types (type0, type1))
7827 return pointer_diff (op0, op1);
7828 /* Handle pointer minus int. Just like pointer plus int. */
7829 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7830 return pointer_int_sum (MINUS_EXPR, op0, op1);
7831 else
7832 common = 1;
7833 break;
7834
7835 case MULT_EXPR:
7836 common = 1;
7837 break;
7838
7839 case TRUNC_DIV_EXPR:
7840 case CEIL_DIV_EXPR:
7841 case FLOOR_DIV_EXPR:
7842 case ROUND_DIV_EXPR:
7843 case EXACT_DIV_EXPR:
7844 /* Floating point division by zero is a legitimate way to obtain
7845 infinities and NaNs. */
7846 if (skip_evaluation == 0 && integer_zerop (op1))
7847 warning (OPT_Wdiv_by_zero, "division by zero");
7848
7849 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7850 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7851 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7852 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
7853 {
7854 enum tree_code tcode0 = code0, tcode1 = code1;
7855
7856 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7857 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
7858 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
7859 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
7860
7861 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
7862 resultcode = RDIV_EXPR;
7863 else
7864 /* Although it would be tempting to shorten always here, that
7865 loses on some targets, since the modulo instruction is
7866 undefined if the quotient can't be represented in the
7867 computation mode. We shorten only if unsigned or if
7868 dividing by something we know != -1. */
7869 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7870 || (TREE_CODE (op1) == INTEGER_CST
7871 && !integer_all_onesp (op1)));
7872 common = 1;
7873 }
7874 break;
7875
7876 case BIT_AND_EXPR:
7877 case BIT_IOR_EXPR:
7878 case BIT_XOR_EXPR:
7879 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7880 shorten = -1;
7881 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
7882 common = 1;
7883 break;
7884
7885 case TRUNC_MOD_EXPR:
7886 case FLOOR_MOD_EXPR:
7887 if (skip_evaluation == 0 && integer_zerop (op1))
7888 warning (OPT_Wdiv_by_zero, "division by zero");
7889
7890 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7891 {
7892 /* Although it would be tempting to shorten always here, that loses
7893 on some targets, since the modulo instruction is undefined if the
7894 quotient can't be represented in the computation mode. We shorten
7895 only if unsigned or if dividing by something we know != -1. */
7896 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7897 || (TREE_CODE (op1) == INTEGER_CST
7898 && !integer_all_onesp (op1)));
7899 common = 1;
7900 }
7901 break;
7902
7903 case TRUTH_ANDIF_EXPR:
7904 case TRUTH_ORIF_EXPR:
7905 case TRUTH_AND_EXPR:
7906 case TRUTH_OR_EXPR:
7907 case TRUTH_XOR_EXPR:
7908 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
7909 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
7910 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
7911 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
7912 {
7913 /* Result of these operations is always an int,
7914 but that does not mean the operands should be
7915 converted to ints! */
7916 result_type = integer_type_node;
7917 op0 = c_common_truthvalue_conversion (op0);
7918 op1 = c_common_truthvalue_conversion (op1);
7919 converted = 1;
7920 }
7921 break;
7922
7923 /* Shift operations: result has same type as first operand;
7924 always convert second operand to int.
7925 Also set SHORT_SHIFT if shifting rightward. */
7926
7927 case RSHIFT_EXPR:
7928 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7929 {
7930 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7931 {
7932 if (tree_int_cst_sgn (op1) < 0)
7933 warning (0, "right shift count is negative");
7934 else
7935 {
7936 if (!integer_zerop (op1))
7937 short_shift = 1;
7938
7939 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7940 warning (0, "right shift count >= width of type");
7941 }
7942 }
7943
7944 /* Use the type of the value to be shifted. */
7945 result_type = type0;
7946 /* Convert the shift-count to an integer, regardless of size
7947 of value being shifted. */
7948 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7949 op1 = convert (integer_type_node, op1);
7950 /* Avoid converting op1 to result_type later. */
7951 converted = 1;
7952 }
7953 break;
7954
7955 case LSHIFT_EXPR:
7956 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7957 {
7958 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7959 {
7960 if (tree_int_cst_sgn (op1) < 0)
7961 warning (0, "left shift count is negative");
7962
7963 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7964 warning (0, "left shift count >= width of type");
7965 }
7966
7967 /* Use the type of the value to be shifted. */
7968 result_type = type0;
7969 /* Convert the shift-count to an integer, regardless of size
7970 of value being shifted. */
7971 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7972 op1 = convert (integer_type_node, op1);
7973 /* Avoid converting op1 to result_type later. */
7974 converted = 1;
7975 }
7976 break;
7977
7978 case EQ_EXPR:
7979 case NE_EXPR:
7980 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
7981 warning (OPT_Wfloat_equal,
7982 "comparing floating point with == or != is unsafe");
7983 /* Result of comparison is always int,
7984 but don't convert the args to int! */
7985 build_type = integer_type_node;
7986 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7987 || code0 == COMPLEX_TYPE)
7988 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7989 || code1 == COMPLEX_TYPE))
7990 short_compare = 1;
7991 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
7992 {
7993 tree tt0 = TREE_TYPE (type0);
7994 tree tt1 = TREE_TYPE (type1);
7995 /* Anything compares with void *. void * compares with anything.
7996 Otherwise, the targets must be compatible
7997 and both must be object or both incomplete. */
7998 if (comp_target_types (type0, type1))
7999 result_type = common_pointer_type (type0, type1);
8000 else if (VOID_TYPE_P (tt0))
8001 {
8002 /* op0 != orig_op0 detects the case of something
8003 whose value is 0 but which isn't a valid null ptr const. */
8004 if (pedantic && !null_pointer_constant_p (orig_op0)
8005 && TREE_CODE (tt1) == FUNCTION_TYPE)
8006 pedwarn ("ISO C forbids comparison of %<void *%>"
8007 " with function pointer");
8008 }
8009 else if (VOID_TYPE_P (tt1))
8010 {
8011 if (pedantic && !null_pointer_constant_p (orig_op1)
8012 && TREE_CODE (tt0) == FUNCTION_TYPE)
8013 pedwarn ("ISO C forbids comparison of %<void *%>"
8014 " with function pointer");
8015 }
8016 else
8017 /* Avoid warning about the volatile ObjC EH puts on decls. */
8018 if (!objc_ok)
8019 pedwarn ("comparison of distinct pointer types lacks a cast");
8020
8021 if (result_type == NULL_TREE)
8022 result_type = ptr_type_node;
8023 }
8024 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8025 {
8026 if (TREE_CODE (op0) == ADDR_EXPR
8027 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
8028 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8029 TREE_OPERAND (op0, 0));
8030 result_type = type0;
8031 }
8032 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8033 {
8034 if (TREE_CODE (op1) == ADDR_EXPR
8035 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
8036 warning (OPT_Walways_true, "the address of %qD will never be NULL",
8037 TREE_OPERAND (op1, 0));
8038 result_type = type1;
8039 }
8040 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8041 {
8042 result_type = type0;
8043 pedwarn ("comparison between pointer and integer");
8044 }
8045 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8046 {
8047 result_type = type1;
8048 pedwarn ("comparison between pointer and integer");
8049 }
8050 break;
8051
8052 case LE_EXPR:
8053 case GE_EXPR:
8054 case LT_EXPR:
8055 case GT_EXPR:
8056 build_type = integer_type_node;
8057 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
8058 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
8059 short_compare = 1;
8060 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8061 {
8062 if (comp_target_types (type0, type1))
8063 {
8064 result_type = common_pointer_type (type0, type1);
8065 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8066 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8067 pedwarn ("comparison of complete and incomplete pointers");
8068 else if (pedantic
8069 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8070 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
8071 }
8072 else
8073 {
8074 result_type = ptr_type_node;
8075 pedwarn ("comparison of distinct pointer types lacks a cast");
8076 }
8077 }
8078 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8079 {
8080 result_type = type0;
8081 if (pedantic || extra_warnings)
8082 pedwarn ("ordered comparison of pointer with integer zero");
8083 }
8084 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8085 {
8086 result_type = type1;
8087 if (pedantic)
8088 pedwarn ("ordered comparison of pointer with integer zero");
8089 }
8090 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8091 {
8092 result_type = type0;
8093 pedwarn ("comparison between pointer and integer");
8094 }
8095 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8096 {
8097 result_type = type1;
8098 pedwarn ("comparison between pointer and integer");
8099 }
8100 break;
8101
8102 default:
8103 gcc_unreachable ();
8104 }
8105
8106 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8107 return error_mark_node;
8108
8109 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8110 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8111 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8112 TREE_TYPE (type1))))
8113 {
8114 binary_op_error (code);
8115 return error_mark_node;
8116 }
8117
8118 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8119 || code0 == VECTOR_TYPE)
8120 &&
8121 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8122 || code1 == VECTOR_TYPE))
8123 {
8124 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8125
8126 if (shorten || common || short_compare)
8127 result_type = c_common_type (type0, type1);
8128
8129 /* For certain operations (which identify themselves by shorten != 0)
8130 if both args were extended from the same smaller type,
8131 do the arithmetic in that type and then extend.
8132
8133 shorten !=0 and !=1 indicates a bitwise operation.
8134 For them, this optimization is safe only if
8135 both args are zero-extended or both are sign-extended.
8136 Otherwise, we might change the result.
8137 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8138 but calculated in (unsigned short) it would be (unsigned short)-1. */
8139
8140 if (shorten && none_complex)
8141 {
8142 int unsigned0, unsigned1;
8143 tree arg0, arg1;
8144 int uns;
8145 tree type;
8146
8147 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8148 excessive narrowing when we call get_narrower below. For
8149 example, suppose that OP0 is of unsigned int extended
8150 from signed char and that RESULT_TYPE is long long int.
8151 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8152 like
8153
8154 (long long int) (unsigned int) signed_char
8155
8156 which get_narrower would narrow down to
8157
8158 (unsigned int) signed char
8159
8160 If we do not cast OP0 first, get_narrower would return
8161 signed_char, which is inconsistent with the case of the
8162 explicit cast. */
8163 op0 = convert (result_type, op0);
8164 op1 = convert (result_type, op1);
8165
8166 arg0 = get_narrower (op0, &unsigned0);
8167 arg1 = get_narrower (op1, &unsigned1);
8168
8169 /* UNS is 1 if the operation to be done is an unsigned one. */
8170 uns = TYPE_UNSIGNED (result_type);
8171
8172 final_type = result_type;
8173
8174 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8175 but it *requires* conversion to FINAL_TYPE. */
8176
8177 if ((TYPE_PRECISION (TREE_TYPE (op0))
8178 == TYPE_PRECISION (TREE_TYPE (arg0)))
8179 && TREE_TYPE (op0) != final_type)
8180 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
8181 if ((TYPE_PRECISION (TREE_TYPE (op1))
8182 == TYPE_PRECISION (TREE_TYPE (arg1)))
8183 && TREE_TYPE (op1) != final_type)
8184 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
8185
8186 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8187
8188 /* For bitwise operations, signedness of nominal type
8189 does not matter. Consider only how operands were extended. */
8190 if (shorten == -1)
8191 uns = unsigned0;
8192
8193 /* Note that in all three cases below we refrain from optimizing
8194 an unsigned operation on sign-extended args.
8195 That would not be valid. */
8196
8197 /* Both args variable: if both extended in same way
8198 from same width, do it in that width.
8199 Do it unsigned if args were zero-extended. */
8200 if ((TYPE_PRECISION (TREE_TYPE (arg0))
8201 < TYPE_PRECISION (result_type))
8202 && (TYPE_PRECISION (TREE_TYPE (arg1))
8203 == TYPE_PRECISION (TREE_TYPE (arg0)))
8204 && unsigned0 == unsigned1
8205 && (unsigned0 || !uns))
8206 result_type
8207 = c_common_signed_or_unsigned_type
8208 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
8209 else if (TREE_CODE (arg0) == INTEGER_CST
8210 && (unsigned1 || !uns)
8211 && (TYPE_PRECISION (TREE_TYPE (arg1))
8212 < TYPE_PRECISION (result_type))
8213 && (type
8214 = c_common_signed_or_unsigned_type (unsigned1,
8215 TREE_TYPE (arg1)),
8216 int_fits_type_p (arg0, type)))
8217 result_type = type;
8218 else if (TREE_CODE (arg1) == INTEGER_CST
8219 && (unsigned0 || !uns)
8220 && (TYPE_PRECISION (TREE_TYPE (arg0))
8221 < TYPE_PRECISION (result_type))
8222 && (type
8223 = c_common_signed_or_unsigned_type (unsigned0,
8224 TREE_TYPE (arg0)),
8225 int_fits_type_p (arg1, type)))
8226 result_type = type;
8227 }
8228
8229 /* Shifts can be shortened if shifting right. */
8230
8231 if (short_shift)
8232 {
8233 int unsigned_arg;
8234 tree arg0 = get_narrower (op0, &unsigned_arg);
8235
8236 final_type = result_type;
8237
8238 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8239 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8240
8241 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8242 /* We can shorten only if the shift count is less than the
8243 number of bits in the smaller type size. */
8244 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8245 /* We cannot drop an unsigned shift after sign-extension. */
8246 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8247 {
8248 /* Do an unsigned shift if the operand was zero-extended. */
8249 result_type
8250 = c_common_signed_or_unsigned_type (unsigned_arg,
8251 TREE_TYPE (arg0));
8252 /* Convert value-to-be-shifted to that type. */
8253 if (TREE_TYPE (op0) != result_type)
8254 op0 = convert (result_type, op0);
8255 converted = 1;
8256 }
8257 }
8258
8259 /* Comparison operations are shortened too but differently.
8260 They identify themselves by setting short_compare = 1. */
8261
8262 if (short_compare)
8263 {
8264 /* Don't write &op0, etc., because that would prevent op0
8265 from being kept in a register.
8266 Instead, make copies of the our local variables and
8267 pass the copies by reference, then copy them back afterward. */
8268 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8269 enum tree_code xresultcode = resultcode;
8270 tree val
8271 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8272
8273 if (val != 0)
8274 return val;
8275
8276 op0 = xop0, op1 = xop1;
8277 converted = 1;
8278 resultcode = xresultcode;
8279
8280 if (warn_sign_compare && skip_evaluation == 0)
8281 {
8282 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8283 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8284 int unsignedp0, unsignedp1;
8285 tree primop0 = get_narrower (op0, &unsignedp0);
8286 tree primop1 = get_narrower (op1, &unsignedp1);
8287
8288 xop0 = orig_op0;
8289 xop1 = orig_op1;
8290 STRIP_TYPE_NOPS (xop0);
8291 STRIP_TYPE_NOPS (xop1);
8292
8293 /* Give warnings for comparisons between signed and unsigned
8294 quantities that may fail.
8295
8296 Do the checking based on the original operand trees, so that
8297 casts will be considered, but default promotions won't be.
8298
8299 Do not warn if the comparison is being done in a signed type,
8300 since the signed type will only be chosen if it can represent
8301 all the values of the unsigned type. */
8302 if (!TYPE_UNSIGNED (result_type))
8303 /* OK */;
8304 /* Do not warn if both operands are the same signedness. */
8305 else if (op0_signed == op1_signed)
8306 /* OK */;
8307 else
8308 {
8309 tree sop, uop;
8310 bool ovf;
8311
8312 if (op0_signed)
8313 sop = xop0, uop = xop1;
8314 else
8315 sop = xop1, uop = xop0;
8316
8317 /* Do not warn if the signed quantity is an
8318 unsuffixed integer literal (or some static
8319 constant expression involving such literals or a
8320 conditional expression involving such literals)
8321 and it is non-negative. */
8322 if (tree_expr_nonnegative_warnv_p (sop, &ovf))
8323 /* OK */;
8324 /* Do not warn if the comparison is an equality operation,
8325 the unsigned quantity is an integral constant, and it
8326 would fit in the result if the result were signed. */
8327 else if (TREE_CODE (uop) == INTEGER_CST
8328 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8329 && int_fits_type_p
8330 (uop, c_common_signed_type (result_type)))
8331 /* OK */;
8332 /* Do not warn if the unsigned quantity is an enumeration
8333 constant and its maximum value would fit in the result
8334 if the result were signed. */
8335 else if (TREE_CODE (uop) == INTEGER_CST
8336 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8337 && int_fits_type_p
8338 (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8339 c_common_signed_type (result_type)))
8340 /* OK */;
8341 else
8342 warning (0, "comparison between signed and unsigned");
8343 }
8344
8345 /* Warn if two unsigned values are being compared in a size
8346 larger than their original size, and one (and only one) is the
8347 result of a `~' operator. This comparison will always fail.
8348
8349 Also warn if one operand is a constant, and the constant
8350 does not have all bits set that are set in the ~ operand
8351 when it is extended. */
8352
8353 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
8354 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
8355 {
8356 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
8357 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
8358 &unsignedp0);
8359 else
8360 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
8361 &unsignedp1);
8362
8363 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
8364 {
8365 tree primop;
8366 HOST_WIDE_INT constant, mask;
8367 int unsignedp, bits;
8368
8369 if (host_integerp (primop0, 0))
8370 {
8371 primop = primop1;
8372 unsignedp = unsignedp1;
8373 constant = tree_low_cst (primop0, 0);
8374 }
8375 else
8376 {
8377 primop = primop0;
8378 unsignedp = unsignedp0;
8379 constant = tree_low_cst (primop1, 0);
8380 }
8381
8382 bits = TYPE_PRECISION (TREE_TYPE (primop));
8383 if (bits < TYPE_PRECISION (result_type)
8384 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
8385 {
8386 mask = (~(HOST_WIDE_INT) 0) << bits;
8387 if ((mask & constant) != mask)
8388 warning (0, "comparison of promoted ~unsigned with constant");
8389 }
8390 }
8391 else if (unsignedp0 && unsignedp1
8392 && (TYPE_PRECISION (TREE_TYPE (primop0))
8393 < TYPE_PRECISION (result_type))
8394 && (TYPE_PRECISION (TREE_TYPE (primop1))
8395 < TYPE_PRECISION (result_type)))
8396 warning (0, "comparison of promoted ~unsigned with unsigned");
8397 }
8398 }
8399 }
8400 }
8401
8402 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8403 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8404 Then the expression will be built.
8405 It will be given type FINAL_TYPE if that is nonzero;
8406 otherwise, it will be given type RESULT_TYPE. */
8407
8408 if (!result_type)
8409 {
8410 binary_op_error (code);
8411 return error_mark_node;
8412 }
8413
8414 if (!converted)
8415 {
8416 if (TREE_TYPE (op0) != result_type)
8417 op0 = convert_and_check (result_type, op0);
8418 if (TREE_TYPE (op1) != result_type)
8419 op1 = convert_and_check (result_type, op1);
8420
8421 /* This can happen if one operand has a vector type, and the other
8422 has a different type. */
8423 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8424 return error_mark_node;
8425 }
8426
8427 if (build_type == NULL_TREE)
8428 build_type = result_type;
8429
8430 {
8431 /* Treat expressions in initializers specially as they can't trap. */
8432 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8433 build_type,
8434 op0, op1)
8435 : fold_build2 (resultcode, build_type,
8436 op0, op1);
8437
8438 if (final_type != 0)
8439 result = convert (final_type, result);
8440 return result;
8441 }
8442 }
8443
8444
8445 /* Convert EXPR to be a truth-value, validating its type for this
8446 purpose. */
8447
8448 tree
8449 c_objc_common_truthvalue_conversion (tree expr)
8450 {
8451 switch (TREE_CODE (TREE_TYPE (expr)))
8452 {
8453 case ARRAY_TYPE:
8454 error ("used array that cannot be converted to pointer where scalar is required");
8455 return error_mark_node;
8456
8457 case RECORD_TYPE:
8458 error ("used struct type value where scalar is required");
8459 return error_mark_node;
8460
8461 case UNION_TYPE:
8462 error ("used union type value where scalar is required");
8463 return error_mark_node;
8464
8465 case FUNCTION_TYPE:
8466 gcc_unreachable ();
8467
8468 default:
8469 break;
8470 }
8471
8472 /* ??? Should we also give an error for void and vectors rather than
8473 leaving those to give errors later? */
8474 return c_common_truthvalue_conversion (expr);
8475 }
8476 \f
8477
8478 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8479 required. */
8480
8481 tree
8482 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
8483 bool *ti ATTRIBUTE_UNUSED, bool *se)
8484 {
8485 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8486 {
8487 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8488 /* Executing a compound literal inside a function reinitializes
8489 it. */
8490 if (!TREE_STATIC (decl))
8491 *se = true;
8492 return decl;
8493 }
8494 else
8495 return expr;
8496 }
8497 \f
8498 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8499
8500 tree
8501 c_begin_omp_parallel (void)
8502 {
8503 tree block;
8504
8505 keep_next_level ();
8506 block = c_begin_compound_stmt (true);
8507
8508 return block;
8509 }
8510
8511 tree
8512 c_finish_omp_parallel (tree clauses, tree block)
8513 {
8514 tree stmt;
8515
8516 block = c_end_compound_stmt (block, true);
8517
8518 stmt = make_node (OMP_PARALLEL);
8519 TREE_TYPE (stmt) = void_type_node;
8520 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8521 OMP_PARALLEL_BODY (stmt) = block;
8522
8523 return add_stmt (stmt);
8524 }
8525
8526 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8527 Remove any elements from the list that are invalid. */
8528
8529 tree
8530 c_finish_omp_clauses (tree clauses)
8531 {
8532 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8533 tree c, t, *pc = &clauses;
8534 const char *name;
8535
8536 bitmap_obstack_initialize (NULL);
8537 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8538 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8539 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8540
8541 for (pc = &clauses, c = clauses; c ; c = *pc)
8542 {
8543 bool remove = false;
8544 bool need_complete = false;
8545 bool need_implicitly_determined = false;
8546
8547 switch (OMP_CLAUSE_CODE (c))
8548 {
8549 case OMP_CLAUSE_SHARED:
8550 name = "shared";
8551 need_implicitly_determined = true;
8552 goto check_dup_generic;
8553
8554 case OMP_CLAUSE_PRIVATE:
8555 name = "private";
8556 need_complete = true;
8557 need_implicitly_determined = true;
8558 goto check_dup_generic;
8559
8560 case OMP_CLAUSE_REDUCTION:
8561 name = "reduction";
8562 need_implicitly_determined = true;
8563 t = OMP_CLAUSE_DECL (c);
8564 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8565 || POINTER_TYPE_P (TREE_TYPE (t)))
8566 {
8567 error ("%qE has invalid type for %<reduction%>", t);
8568 remove = true;
8569 }
8570 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8571 {
8572 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8573 const char *r_name = NULL;
8574
8575 switch (r_code)
8576 {
8577 case PLUS_EXPR:
8578 case MULT_EXPR:
8579 case MINUS_EXPR:
8580 break;
8581 case BIT_AND_EXPR:
8582 r_name = "&";
8583 break;
8584 case BIT_XOR_EXPR:
8585 r_name = "^";
8586 break;
8587 case BIT_IOR_EXPR:
8588 r_name = "|";
8589 break;
8590 case TRUTH_ANDIF_EXPR:
8591 r_name = "&&";
8592 break;
8593 case TRUTH_ORIF_EXPR:
8594 r_name = "||";
8595 break;
8596 default:
8597 gcc_unreachable ();
8598 }
8599 if (r_name)
8600 {
8601 error ("%qE has invalid type for %<reduction(%s)%>",
8602 t, r_name);
8603 remove = true;
8604 }
8605 }
8606 goto check_dup_generic;
8607
8608 case OMP_CLAUSE_COPYPRIVATE:
8609 name = "copyprivate";
8610 goto check_dup_generic;
8611
8612 case OMP_CLAUSE_COPYIN:
8613 name = "copyin";
8614 t = OMP_CLAUSE_DECL (c);
8615 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8616 {
8617 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8618 remove = true;
8619 }
8620 goto check_dup_generic;
8621
8622 check_dup_generic:
8623 t = OMP_CLAUSE_DECL (c);
8624 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8625 {
8626 error ("%qE is not a variable in clause %qs", t, name);
8627 remove = true;
8628 }
8629 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8630 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8631 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8632 {
8633 error ("%qE appears more than once in data clauses", t);
8634 remove = true;
8635 }
8636 else
8637 bitmap_set_bit (&generic_head, DECL_UID (t));
8638 break;
8639
8640 case OMP_CLAUSE_FIRSTPRIVATE:
8641 name = "firstprivate";
8642 t = OMP_CLAUSE_DECL (c);
8643 need_complete = true;
8644 need_implicitly_determined = true;
8645 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8646 {
8647 error ("%qE is not a variable in clause %<firstprivate%>", t);
8648 remove = true;
8649 }
8650 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8651 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8652 {
8653 error ("%qE appears more than once in data clauses", t);
8654 remove = true;
8655 }
8656 else
8657 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8658 break;
8659
8660 case OMP_CLAUSE_LASTPRIVATE:
8661 name = "lastprivate";
8662 t = OMP_CLAUSE_DECL (c);
8663 need_complete = true;
8664 need_implicitly_determined = true;
8665 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8666 {
8667 error ("%qE is not a variable in clause %<lastprivate%>", t);
8668 remove = true;
8669 }
8670 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8671 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8672 {
8673 error ("%qE appears more than once in data clauses", t);
8674 remove = true;
8675 }
8676 else
8677 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8678 break;
8679
8680 case OMP_CLAUSE_IF:
8681 case OMP_CLAUSE_NUM_THREADS:
8682 case OMP_CLAUSE_SCHEDULE:
8683 case OMP_CLAUSE_NOWAIT:
8684 case OMP_CLAUSE_ORDERED:
8685 case OMP_CLAUSE_DEFAULT:
8686 pc = &OMP_CLAUSE_CHAIN (c);
8687 continue;
8688
8689 default:
8690 gcc_unreachable ();
8691 }
8692
8693 if (!remove)
8694 {
8695 t = OMP_CLAUSE_DECL (c);
8696
8697 if (need_complete)
8698 {
8699 t = require_complete_type (t);
8700 if (t == error_mark_node)
8701 remove = true;
8702 }
8703
8704 if (need_implicitly_determined)
8705 {
8706 const char *share_name = NULL;
8707
8708 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8709 share_name = "threadprivate";
8710 else switch (c_omp_predetermined_sharing (t))
8711 {
8712 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8713 break;
8714 case OMP_CLAUSE_DEFAULT_SHARED:
8715 share_name = "shared";
8716 break;
8717 case OMP_CLAUSE_DEFAULT_PRIVATE:
8718 share_name = "private";
8719 break;
8720 default:
8721 gcc_unreachable ();
8722 }
8723 if (share_name)
8724 {
8725 error ("%qE is predetermined %qs for %qs",
8726 t, share_name, name);
8727 remove = true;
8728 }
8729 }
8730 }
8731
8732 if (remove)
8733 *pc = OMP_CLAUSE_CHAIN (c);
8734 else
8735 pc = &OMP_CLAUSE_CHAIN (c);
8736 }
8737
8738 bitmap_obstack_release (NULL);
8739 return clauses;
8740 }
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