1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
22
23
24 /* This file is part of the C front end.
25 It contains routines to build C expressions given their operands,
26 including computing the types of the result, C-specific error checks,
27 and some optimization. */
28
29 #include "config.h"
30 #include "system.h"
31 #include "coretypes.h"
32 #include "tm.h"
33 #include "rtl.h"
34 #include "tree.h"
35 #include "langhooks.h"
36 #include "c-tree.h"
37 #include "tm_p.h"
38 #include "flags.h"
39 #include "output.h"
40 #include "expr.h"
41 #include "toplev.h"
42 #include "intl.h"
43 #include "ggc.h"
44 #include "target.h"
45 #include "tree-iterator.h"
46 #include "tree-gimple.h"
47 #include "tree-flow.h"
48
49 /* Possible cases of implicit bad conversions. Used to select
50 diagnostic messages in convert_for_assignment. */
51 enum impl_conv {
52 ic_argpass,
53 ic_argpass_nonproto,
54 ic_assign,
55 ic_init,
56 ic_return
57 };
58
59 /* The level of nesting inside "__alignof__". */
60 int in_alignof;
61
62 /* The level of nesting inside "sizeof". */
63 int in_sizeof;
64
65 /* The level of nesting inside "typeof". */
66 int in_typeof;
67
68 struct c_label_context_se *label_context_stack_se;
69 struct c_label_context_vm *label_context_stack_vm;
70
71 /* Nonzero if we've already printed a "missing braces around initializer"
72 message within this initializer. */
73 static int missing_braces_mentioned;
74
75 static int require_constant_value;
76 static int require_constant_elements;
77
78 static bool null_pointer_constant_p (tree);
79 static tree qualify_type (tree, tree);
80 static int tagged_types_tu_compatible_p (tree, tree);
81 static int comp_target_types (tree, tree);
82 static int function_types_compatible_p (tree, tree);
83 static int type_lists_compatible_p (tree, tree);
84 static tree decl_constant_value_for_broken_optimization (tree);
85 static tree lookup_field (tree, tree);
86 static tree convert_arguments (tree, tree, tree, tree);
87 static tree pointer_diff (tree, tree);
88 static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree,
89 int);
90 static tree valid_compound_expr_initializer (tree, tree);
91 static void push_string (const char *);
92 static void push_member_name (tree);
93 static int spelling_length (void);
94 static char *print_spelling (char *);
95 static void warning_init (const char *);
96 static tree digest_init (tree, tree, bool, int);
97 static void output_init_element (tree, bool, tree, tree, int);
98 static void output_pending_init_elements (int);
99 static int set_designator (int);
100 static void push_range_stack (tree);
101 static void add_pending_init (tree, tree);
102 static void set_nonincremental_init (void);
103 static void set_nonincremental_init_from_string (tree);
104 static tree find_init_member (tree);
105 static void readonly_error (tree, enum lvalue_use);
106 static int lvalue_or_else (tree, enum lvalue_use);
107 static int lvalue_p (tree);
108 static void record_maybe_used_decl (tree);
109 static int comptypes_internal (tree, tree);
110
111 /* Return true if EXP is a null pointer constant, false otherwise. */
112
113 static bool
null_pointer_constant_p(tree expr)114 null_pointer_constant_p (tree expr)
115 {
116 /* This should really operate on c_expr structures, but they aren't
117 yet available everywhere required. */
118 tree type = TREE_TYPE (expr);
119 return (TREE_CODE (expr) == INTEGER_CST
120 && !TREE_CONSTANT_OVERFLOW (expr)
121 && integer_zerop (expr)
122 && (INTEGRAL_TYPE_P (type)
123 || (TREE_CODE (type) == POINTER_TYPE
124 && VOID_TYPE_P (TREE_TYPE (type))
125 && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED)));
126 }
127 /* 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
require_complete_type(tree value)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
c_incomplete_type_error(tree value,tree type)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
c_type_promotes_to(tree type)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
qualify_type(tree type,tree like)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
c_vla_type_p(tree t)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
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
composite_type(tree t1,tree t2)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
common_pointer_type(tree t1,tree t2)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
c_common_type(tree t1,tree t2)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
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
common_type(tree t1,tree t2)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
comptypes(tree type1,tree type2)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
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
comptypes_internal(tree type1,tree type2)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
comp_target_types(tree ttl,tree ttr)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
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
same_translation_unit_p(tree t1,tree t2)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 *
alloc_tagged_tu_seen_cache(tree t1,tree t2)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
free_all_tagged_tu_seen_up_to(const struct tagged_tu_seen_cache * tu_til)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
tagged_types_tu_compatible_p(tree t1,tree t2)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
function_types_compatible_p(tree f1,tree f2)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
type_lists_compatible_p(tree args1,tree args2)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
1416 /* Compute the size to increment a pointer by. */
1417
1418 static tree
c_size_in_bytes(tree type)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
1438 /* Return either DECL or its known constant value (if it has one). */
1439
1440 tree
decl_constant_value(tree decl)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
decl_constant_value_for_broken_optimization(tree decl)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
array_to_pointer_conversion(tree exp)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
function_to_pointer_conversion(tree exp)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
default_function_array_conversion(struct c_expr exp)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
perform_integral_promotions(tree exp)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
default_conversion(tree exp)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
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
lookup_field(tree decl,tree component)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
build_component_ref(tree datum,tree component)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
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
build_indirect_ref(tree ptr,const char * errorstring)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
build_array_ref(tree array,tree index)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
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
build_external_ref(tree id,int fun,location_t loc)2050 build_external_ref (tree id, int fun, location_t loc)
2051 {
2052 tree ref;
2053 tree decl = lookup_name (id);
2054
2055 /* In Objective-C, an instance variable (ivar) may be preferred to
2056 whatever lookup_name() found. */
2057 decl = objc_lookup_ivar (decl, id);
2058
2059 if (decl && decl != error_mark_node)
2060 ref = decl;
2061 else if (fun)
2062 /* Implicit function declaration. */
2063 ref = implicitly_declare (id);
2064 else if (decl == error_mark_node)
2065 /* Don't complain about something that's already been
2066 complained about. */
2067 return error_mark_node;
2068 else
2069 {
2070 undeclared_variable (id, loc);
2071 return error_mark_node;
2072 }
2073
2074 if (TREE_TYPE (ref) == error_mark_node)
2075 return error_mark_node;
2076
2077 if (TREE_DEPRECATED (ref))
2078 warn_deprecated_use (ref);
2079
2080 if (!skip_evaluation)
2081 assemble_external (ref);
2082 TREE_USED (ref) = 1;
2083
2084 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof)
2085 {
2086 if (!in_sizeof && !in_typeof)
2087 C_DECL_USED (ref) = 1;
2088 else if (DECL_INITIAL (ref) == 0
2089 && DECL_EXTERNAL (ref)
2090 && !TREE_PUBLIC (ref))
2091 record_maybe_used_decl (ref);
2092 }
2093
2094 if (TREE_CODE (ref) == CONST_DECL)
2095 {
2096 used_types_insert (TREE_TYPE (ref));
2097 ref = DECL_INITIAL (ref);
2098 TREE_CONSTANT (ref) = 1;
2099 TREE_INVARIANT (ref) = 1;
2100 }
2101 else if (current_function_decl != 0
2102 && !DECL_FILE_SCOPE_P (current_function_decl)
2103 && (TREE_CODE (ref) == VAR_DECL
2104 || TREE_CODE (ref) == PARM_DECL
2105 || TREE_CODE (ref) == FUNCTION_DECL))
2106 {
2107 tree context = decl_function_context (ref);
2108
2109 if (context != 0 && context != current_function_decl)
2110 DECL_NONLOCAL (ref) = 1;
2111 }
2112
2113 return ref;
2114 }
2115
2116 /* Record details of decls possibly used inside sizeof or typeof. */
2117 struct maybe_used_decl
2118 {
2119 /* The decl. */
2120 tree decl;
2121 /* The level seen at (in_sizeof + in_typeof). */
2122 int level;
2123 /* The next one at this level or above, or NULL. */
2124 struct maybe_used_decl *next;
2125 };
2126
2127 static struct maybe_used_decl *maybe_used_decls;
2128
2129 /* Record that DECL, an undefined static function reference seen
2130 inside sizeof or typeof, might be used if the operand of sizeof is
2131 a VLA type or the operand of typeof is a variably modified
2132 type. */
2133
2134 static void
record_maybe_used_decl(tree decl)2135 record_maybe_used_decl (tree decl)
2136 {
2137 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2138 t->decl = decl;
2139 t->level = in_sizeof + in_typeof;
2140 t->next = maybe_used_decls;
2141 maybe_used_decls = t;
2142 }
2143
2144 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2145 USED is false, just discard them. If it is true, mark them used
2146 (if no longer inside sizeof or typeof) or move them to the next
2147 level up (if still inside sizeof or typeof). */
2148
2149 void
pop_maybe_used(bool used)2150 pop_maybe_used (bool used)
2151 {
2152 struct maybe_used_decl *p = maybe_used_decls;
2153 int cur_level = in_sizeof + in_typeof;
2154 while (p && p->level > cur_level)
2155 {
2156 if (used)
2157 {
2158 if (cur_level == 0)
2159 C_DECL_USED (p->decl) = 1;
2160 else
2161 p->level = cur_level;
2162 }
2163 p = p->next;
2164 }
2165 if (!used || cur_level == 0)
2166 maybe_used_decls = p;
2167 }
2168
2169 /* Return the result of sizeof applied to EXPR. */
2170
2171 struct c_expr
c_expr_sizeof_expr(struct c_expr expr)2172 c_expr_sizeof_expr (struct c_expr expr)
2173 {
2174 struct c_expr ret;
2175 if (expr.value == error_mark_node)
2176 {
2177 ret.value = error_mark_node;
2178 ret.original_code = ERROR_MARK;
2179 pop_maybe_used (false);
2180 }
2181 else
2182 {
2183 ret.value = c_sizeof (TREE_TYPE (expr.value));
2184 ret.original_code = ERROR_MARK;
2185 if (c_vla_type_p (TREE_TYPE (expr.value)))
2186 {
2187 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2188 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2189 }
2190 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2191 }
2192 return ret;
2193 }
2194
2195 /* Return the result of sizeof applied to T, a structure for the type
2196 name passed to sizeof (rather than the type itself). */
2197
2198 struct c_expr
c_expr_sizeof_type(struct c_type_name * t)2199 c_expr_sizeof_type (struct c_type_name *t)
2200 {
2201 tree type;
2202 struct c_expr ret;
2203 type = groktypename (t);
2204 ret.value = c_sizeof (type);
2205 ret.original_code = ERROR_MARK;
2206 pop_maybe_used (type != error_mark_node
2207 ? C_TYPE_VARIABLE_SIZE (type) : false);
2208 return ret;
2209 }
2210
2211 /* Build a function call to function FUNCTION with parameters PARAMS.
2212 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2213 TREE_VALUE of each node is a parameter-expression.
2214 FUNCTION's data type may be a function type or a pointer-to-function. */
2215
2216 tree
build_function_call(tree function,tree params)2217 build_function_call (tree function, tree params)
2218 {
2219 tree fntype, fundecl = 0;
2220 tree coerced_params;
2221 tree name = NULL_TREE, result;
2222 tree tem;
2223
2224 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2225 STRIP_TYPE_NOPS (function);
2226
2227 /* Convert anything with function type to a pointer-to-function. */
2228 if (TREE_CODE (function) == FUNCTION_DECL)
2229 {
2230 /* Implement type-directed function overloading for builtins.
2231 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2232 handle all the type checking. The result is a complete expression
2233 that implements this function call. */
2234 tem = resolve_overloaded_builtin (function, params);
2235 if (tem)
2236 return tem;
2237
2238 name = DECL_NAME (function);
2239 fundecl = function;
2240 }
2241 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2242 function = function_to_pointer_conversion (function);
2243
2244 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2245 expressions, like those used for ObjC messenger dispatches. */
2246 function = objc_rewrite_function_call (function, params);
2247
2248 fntype = TREE_TYPE (function);
2249
2250 if (TREE_CODE (fntype) == ERROR_MARK)
2251 return error_mark_node;
2252
2253 if (!(TREE_CODE (fntype) == POINTER_TYPE
2254 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2255 {
2256 error ("called object %qE is not a function", function);
2257 return error_mark_node;
2258 }
2259
2260 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2261 current_function_returns_abnormally = 1;
2262
2263 /* fntype now gets the type of function pointed to. */
2264 fntype = TREE_TYPE (fntype);
2265
2266 /* Check that the function is called through a compatible prototype.
2267 If it is not, replace the call by a trap, wrapped up in a compound
2268 expression if necessary. This has the nice side-effect to prevent
2269 the tree-inliner from generating invalid assignment trees which may
2270 blow up in the RTL expander later. */
2271 if ((TREE_CODE (function) == NOP_EXPR
2272 || TREE_CODE (function) == CONVERT_EXPR)
2273 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2274 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2275 && !comptypes (fntype, TREE_TYPE (tem)))
2276 {
2277 tree return_type = TREE_TYPE (fntype);
2278 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2279 NULL_TREE);
2280
2281 /* This situation leads to run-time undefined behavior. We can't,
2282 therefore, simply error unless we can prove that all possible
2283 executions of the program must execute the code. */
2284 warning (0, "function called through a non-compatible type");
2285
2286 /* We can, however, treat "undefined" any way we please.
2287 Call abort to encourage the user to fix the program. */
2288 inform ("if this code is reached, the program will abort");
2289
2290 if (VOID_TYPE_P (return_type))
2291 return trap;
2292 else
2293 {
2294 tree rhs;
2295
2296 if (AGGREGATE_TYPE_P (return_type))
2297 rhs = build_compound_literal (return_type,
2298 build_constructor (return_type, 0));
2299 else
2300 rhs = fold_convert (return_type, integer_zero_node);
2301
2302 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2303 }
2304 }
2305
2306 /* Convert the parameters to the types declared in the
2307 function prototype, or apply default promotions. */
2308
2309 coerced_params
2310 = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl);
2311
2312 if (coerced_params == error_mark_node)
2313 return error_mark_node;
2314
2315 /* Check that the arguments to the function are valid. */
2316
2317 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params,
2318 TYPE_ARG_TYPES (fntype));
2319
2320 if (require_constant_value)
2321 {
2322 result = fold_build3_initializer (CALL_EXPR, TREE_TYPE (fntype),
2323 function, coerced_params, NULL_TREE);
2324
2325 if (TREE_CONSTANT (result)
2326 && (name == NULL_TREE
2327 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2328 pedwarn_init ("initializer element is not constant");
2329 }
2330 else
2331 result = fold_build3 (CALL_EXPR, TREE_TYPE (fntype),
2332 function, coerced_params, NULL_TREE);
2333
2334 if (VOID_TYPE_P (TREE_TYPE (result)))
2335 return result;
2336 return require_complete_type (result);
2337 }
2338
2339 /* Convert the argument expressions in the list VALUES
2340 to the types in the list TYPELIST. The result is a list of converted
2341 argument expressions, unless there are too few arguments in which
2342 case it is error_mark_node.
2343
2344 If TYPELIST is exhausted, or when an element has NULL as its type,
2345 perform the default conversions.
2346
2347 PARMLIST is the chain of parm decls for the function being called.
2348 It may be 0, if that info is not available.
2349 It is used only for generating error messages.
2350
2351 FUNCTION is a tree for the called function. It is used only for
2352 error messages, where it is formatted with %qE.
2353
2354 This is also where warnings about wrong number of args are generated.
2355
2356 Both VALUES and the returned value are chains of TREE_LIST nodes
2357 with the elements of the list in the TREE_VALUE slots of those nodes. */
2358
2359 static tree
convert_arguments(tree typelist,tree values,tree function,tree fundecl)2360 convert_arguments (tree typelist, tree values, tree function, tree fundecl)
2361 {
2362 tree typetail, valtail;
2363 tree result = NULL;
2364 int parmnum;
2365 tree selector;
2366
2367 /* Change pointer to function to the function itself for
2368 diagnostics. */
2369 if (TREE_CODE (function) == ADDR_EXPR
2370 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2371 function = TREE_OPERAND (function, 0);
2372
2373 /* Handle an ObjC selector specially for diagnostics. */
2374 selector = objc_message_selector ();
2375
2376 /* Scan the given expressions and types, producing individual
2377 converted arguments and pushing them on RESULT in reverse order. */
2378
2379 for (valtail = values, typetail = typelist, parmnum = 0;
2380 valtail;
2381 valtail = TREE_CHAIN (valtail), parmnum++)
2382 {
2383 tree type = typetail ? TREE_VALUE (typetail) : 0;
2384 tree val = TREE_VALUE (valtail);
2385 tree rname = function;
2386 int argnum = parmnum + 1;
2387 const char *invalid_func_diag;
2388
2389 if (type == void_type_node)
2390 {
2391 error ("too many arguments to function %qE", function);
2392 break;
2393 }
2394
2395 if (selector && argnum > 2)
2396 {
2397 rname = selector;
2398 argnum -= 2;
2399 }
2400
2401 STRIP_TYPE_NOPS (val);
2402
2403 val = require_complete_type (val);
2404
2405 if (type != 0)
2406 {
2407 /* Formal parm type is specified by a function prototype. */
2408 tree parmval;
2409
2410 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2411 {
2412 error ("type of formal parameter %d is incomplete", parmnum + 1);
2413 parmval = val;
2414 }
2415 else
2416 {
2417 /* Optionally warn about conversions that
2418 differ from the default conversions. */
2419 if (warn_conversion || warn_traditional)
2420 {
2421 unsigned int formal_prec = TYPE_PRECISION (type);
2422
2423 if (INTEGRAL_TYPE_P (type)
2424 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2425 warning (0, "passing argument %d of %qE as integer "
2426 "rather than floating due to prototype",
2427 argnum, rname);
2428 if (INTEGRAL_TYPE_P (type)
2429 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2430 warning (0, "passing argument %d of %qE as integer "
2431 "rather than complex due to prototype",
2432 argnum, rname);
2433 else if (TREE_CODE (type) == COMPLEX_TYPE
2434 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2435 warning (0, "passing argument %d of %qE as complex "
2436 "rather than floating due to prototype",
2437 argnum, rname);
2438 else if (TREE_CODE (type) == REAL_TYPE
2439 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2440 warning (0, "passing argument %d of %qE as floating "
2441 "rather than integer due to prototype",
2442 argnum, rname);
2443 else if (TREE_CODE (type) == COMPLEX_TYPE
2444 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2445 warning (0, "passing argument %d of %qE as complex "
2446 "rather than integer due to prototype",
2447 argnum, rname);
2448 else if (TREE_CODE (type) == REAL_TYPE
2449 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2450 warning (0, "passing argument %d of %qE as floating "
2451 "rather than complex due to prototype",
2452 argnum, rname);
2453 /* ??? At some point, messages should be written about
2454 conversions between complex types, but that's too messy
2455 to do now. */
2456 else if (TREE_CODE (type) == REAL_TYPE
2457 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2458 {
2459 /* Warn if any argument is passed as `float',
2460 since without a prototype it would be `double'. */
2461 if (formal_prec == TYPE_PRECISION (float_type_node)
2462 && type != dfloat32_type_node)
2463 warning (0, "passing argument %d of %qE as %<float%> "
2464 "rather than %<double%> due to prototype",
2465 argnum, rname);
2466
2467 /* Warn if mismatch between argument and prototype
2468 for decimal float types. Warn of conversions with
2469 binary float types and of precision narrowing due to
2470 prototype. */
2471 else if (type != TREE_TYPE (val)
2472 && (type == dfloat32_type_node
2473 || type == dfloat64_type_node
2474 || type == dfloat128_type_node
2475 || TREE_TYPE (val) == dfloat32_type_node
2476 || TREE_TYPE (val) == dfloat64_type_node
2477 || TREE_TYPE (val) == dfloat128_type_node)
2478 && (formal_prec
2479 <= TYPE_PRECISION (TREE_TYPE (val))
2480 || (type == dfloat128_type_node
2481 && (TREE_TYPE (val)
2482 != dfloat64_type_node
2483 && (TREE_TYPE (val)
2484 != dfloat32_type_node)))
2485 || (type == dfloat64_type_node
2486 && (TREE_TYPE (val)
2487 != dfloat32_type_node))))
2488 warning (0, "passing argument %d of %qE as %qT "
2489 "rather than %qT due to prototype",
2490 argnum, rname, type, TREE_TYPE (val));
2491
2492 }
2493 /* Detect integer changing in width or signedness.
2494 These warnings are only activated with
2495 -Wconversion, not with -Wtraditional. */
2496 else if (warn_conversion && INTEGRAL_TYPE_P (type)
2497 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2498 {
2499 tree would_have_been = default_conversion (val);
2500 tree type1 = TREE_TYPE (would_have_been);
2501
2502 if (TREE_CODE (type) == ENUMERAL_TYPE
2503 && (TYPE_MAIN_VARIANT (type)
2504 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2505 /* No warning if function asks for enum
2506 and the actual arg is that enum type. */
2507 ;
2508 else if (formal_prec != TYPE_PRECISION (type1))
2509 warning (OPT_Wconversion, "passing argument %d of %qE "
2510 "with different width due to prototype",
2511 argnum, rname);
2512 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2513 ;
2514 /* Don't complain if the formal parameter type
2515 is an enum, because we can't tell now whether
2516 the value was an enum--even the same enum. */
2517 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2518 ;
2519 else if (TREE_CODE (val) == INTEGER_CST
2520 && int_fits_type_p (val, type))
2521 /* Change in signedness doesn't matter
2522 if a constant value is unaffected. */
2523 ;
2524 /* If the value is extended from a narrower
2525 unsigned type, it doesn't matter whether we
2526 pass it as signed or unsigned; the value
2527 certainly is the same either way. */
2528 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2529 && TYPE_UNSIGNED (TREE_TYPE (val)))
2530 ;
2531 else if (TYPE_UNSIGNED (type))
2532 warning (OPT_Wconversion, "passing argument %d of %qE "
2533 "as unsigned due to prototype",
2534 argnum, rname);
2535 else
2536 warning (OPT_Wconversion, "passing argument %d of %qE "
2537 "as signed due to prototype", argnum, rname);
2538 }
2539 }
2540
2541 parmval = convert_for_assignment (type, val, ic_argpass,
2542 fundecl, function,
2543 parmnum + 1);
2544
2545 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2546 && INTEGRAL_TYPE_P (type)
2547 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2548 parmval = default_conversion (parmval);
2549 }
2550 result = tree_cons (NULL_TREE, parmval, result);
2551 }
2552 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2553 && (TYPE_PRECISION (TREE_TYPE (val))
2554 < TYPE_PRECISION (double_type_node))
2555 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2556 /* Convert `float' to `double'. */
2557 result = tree_cons (NULL_TREE, convert (double_type_node, val), result);
2558 else if ((invalid_func_diag =
2559 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2560 {
2561 error (invalid_func_diag);
2562 return error_mark_node;
2563 }
2564 else
2565 /* Convert `short' and `char' to full-size `int'. */
2566 result = tree_cons (NULL_TREE, default_conversion (val), result);
2567
2568 if (typetail)
2569 typetail = TREE_CHAIN (typetail);
2570 }
2571
2572 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2573 {
2574 error ("too few arguments to function %qE", function);
2575 return error_mark_node;
2576 }
2577
2578 return nreverse (result);
2579 }
2580
2581 /* This is the entry point used by the parser to build unary operators
2582 in the input. CODE, a tree_code, specifies the unary operator, and
2583 ARG is the operand. For unary plus, the C parser currently uses
2584 CONVERT_EXPR for code. */
2585
2586 struct c_expr
parser_build_unary_op(enum tree_code code,struct c_expr arg)2587 parser_build_unary_op (enum tree_code code, struct c_expr arg)
2588 {
2589 struct c_expr result;
2590
2591 result.original_code = ERROR_MARK;
2592 result.value = build_unary_op (code, arg.value, 0);
2593 overflow_warning (result.value);
2594 return result;
2595 }
2596
2597 /* This is the entry point used by the parser to build binary operators
2598 in the input. CODE, a tree_code, specifies the binary operator, and
2599 ARG1 and ARG2 are the operands. In addition to constructing the
2600 expression, we check for operands that were written with other binary
2601 operators in a way that is likely to confuse the user. */
2602
2603 struct c_expr
parser_build_binary_op(enum tree_code code,struct c_expr arg1,struct c_expr arg2)2604 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2605 struct c_expr arg2)
2606 {
2607 struct c_expr result;
2608
2609 enum tree_code code1 = arg1.original_code;
2610 enum tree_code code2 = arg2.original_code;
2611
2612 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2613 result.original_code = code;
2614
2615 if (TREE_CODE (result.value) == ERROR_MARK)
2616 return result;
2617
2618 /* Check for cases such as x+y<<z which users are likely
2619 to misinterpret. */
2620 if (warn_parentheses)
2621 {
2622 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
2623 {
2624 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
2625 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2626 warning (OPT_Wparentheses,
2627 "suggest parentheses around + or - inside shift");
2628 }
2629
2630 if (code == TRUTH_ORIF_EXPR)
2631 {
2632 if (code1 == TRUTH_ANDIF_EXPR
2633 || code2 == TRUTH_ANDIF_EXPR)
2634 warning (OPT_Wparentheses,
2635 "suggest parentheses around && within ||");
2636 }
2637
2638 if (code == BIT_IOR_EXPR)
2639 {
2640 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR
2641 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
2642 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR
2643 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2644 warning (OPT_Wparentheses,
2645 "suggest parentheses around arithmetic in operand of |");
2646 /* Check cases like x|y==z */
2647 if (TREE_CODE_CLASS (code1) == tcc_comparison
2648 || TREE_CODE_CLASS (code2) == tcc_comparison)
2649 warning (OPT_Wparentheses,
2650 "suggest parentheses around comparison in operand of |");
2651 }
2652
2653 if (code == BIT_XOR_EXPR)
2654 {
2655 if (code1 == BIT_AND_EXPR
2656 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
2657 || code2 == BIT_AND_EXPR
2658 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2659 warning (OPT_Wparentheses,
2660 "suggest parentheses around arithmetic in operand of ^");
2661 /* Check cases like x^y==z */
2662 if (TREE_CODE_CLASS (code1) == tcc_comparison
2663 || TREE_CODE_CLASS (code2) == tcc_comparison)
2664 warning (OPT_Wparentheses,
2665 "suggest parentheses around comparison in operand of ^");
2666 }
2667
2668 if (code == BIT_AND_EXPR)
2669 {
2670 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
2671 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
2672 warning (OPT_Wparentheses,
2673 "suggest parentheses around + or - in operand of &");
2674 /* Check cases like x&y==z */
2675 if (TREE_CODE_CLASS (code1) == tcc_comparison
2676 || TREE_CODE_CLASS (code2) == tcc_comparison)
2677 warning (OPT_Wparentheses,
2678 "suggest parentheses around comparison in operand of &");
2679 }
2680 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
2681 if (TREE_CODE_CLASS (code) == tcc_comparison
2682 && (TREE_CODE_CLASS (code1) == tcc_comparison
2683 || TREE_CODE_CLASS (code2) == tcc_comparison))
2684 warning (OPT_Wparentheses, "comparisons like X<=Y<=Z do not "
2685 "have their mathematical meaning");
2686
2687 }
2688
2689 /* Warn about comparisons against string literals, with the exception
2690 of testing for equality or inequality of a string literal with NULL. */
2691 if (code == EQ_EXPR || code == NE_EXPR)
2692 {
2693 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2694 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2695 warning (OPT_Waddress,
2696 "comparison with string literal results in unspecified behaviour");
2697 }
2698 else if (TREE_CODE_CLASS (code) == tcc_comparison
2699 && (code1 == STRING_CST || code2 == STRING_CST))
2700 warning (OPT_Waddress,
2701 "comparison with string literal results in unspecified behaviour");
2702
2703 overflow_warning (result.value);
2704
2705 return result;
2706 }
2707
2708 /* Return a tree for the difference of pointers OP0 and OP1.
2709 The resulting tree has type int. */
2710
2711 static tree
pointer_diff(tree op0,tree op1)2712 pointer_diff (tree op0, tree op1)
2713 {
2714 tree restype = ptrdiff_type_node;
2715
2716 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2717 tree con0, con1, lit0, lit1;
2718 tree orig_op1 = op1;
2719
2720 if (pedantic || warn_pointer_arith)
2721 {
2722 if (TREE_CODE (target_type) == VOID_TYPE)
2723 pedwarn ("pointer of type %<void *%> used in subtraction");
2724 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2725 pedwarn ("pointer to a function used in subtraction");
2726 }
2727
2728 /* If the conversion to ptrdiff_type does anything like widening or
2729 converting a partial to an integral mode, we get a convert_expression
2730 that is in the way to do any simplifications.
2731 (fold-const.c doesn't know that the extra bits won't be needed.
2732 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2733 different mode in place.)
2734 So first try to find a common term here 'by hand'; we want to cover
2735 at least the cases that occur in legal static initializers. */
2736 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR)
2737 && (TYPE_PRECISION (TREE_TYPE (op0))
2738 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2739 con0 = TREE_OPERAND (op0, 0);
2740 else
2741 con0 = op0;
2742 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR)
2743 && (TYPE_PRECISION (TREE_TYPE (op1))
2744 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2745 con1 = TREE_OPERAND (op1, 0);
2746 else
2747 con1 = op1;
2748
2749 if (TREE_CODE (con0) == PLUS_EXPR)
2750 {
2751 lit0 = TREE_OPERAND (con0, 1);
2752 con0 = TREE_OPERAND (con0, 0);
2753 }
2754 else
2755 lit0 = integer_zero_node;
2756
2757 if (TREE_CODE (con1) == PLUS_EXPR)
2758 {
2759 lit1 = TREE_OPERAND (con1, 1);
2760 con1 = TREE_OPERAND (con1, 0);
2761 }
2762 else
2763 lit1 = integer_zero_node;
2764
2765 if (operand_equal_p (con0, con1, 0))
2766 {
2767 op0 = lit0;
2768 op1 = lit1;
2769 }
2770
2771
2772 /* First do the subtraction as integers;
2773 then drop through to build the divide operator.
2774 Do not do default conversions on the minus operator
2775 in case restype is a short type. */
2776
2777 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2778 convert (restype, op1), 0);
2779 /* This generates an error if op1 is pointer to incomplete type. */
2780 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2781 error ("arithmetic on pointer to an incomplete type");
2782
2783 /* This generates an error if op0 is pointer to incomplete type. */
2784 op1 = c_size_in_bytes (target_type);
2785
2786 /* Divide by the size, in easiest possible way. */
2787 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2788 }
2789
2790 /* Construct and perhaps optimize a tree representation
2791 for a unary operation. CODE, a tree_code, specifies the operation
2792 and XARG is the operand.
2793 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2794 the default promotions (such as from short to int).
2795 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2796 allows non-lvalues; this is only used to handle conversion of non-lvalue
2797 arrays to pointers in C99. */
2798
2799 tree
build_unary_op(enum tree_code code,tree xarg,int flag)2800 build_unary_op (enum tree_code code, tree xarg, int flag)
2801 {
2802 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2803 tree arg = xarg;
2804 tree argtype = 0;
2805 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2806 tree val;
2807 int noconvert = flag;
2808 const char *invalid_op_diag;
2809
2810 if (typecode == ERROR_MARK)
2811 return error_mark_node;
2812 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2813 typecode = INTEGER_TYPE;
2814
2815 if ((invalid_op_diag
2816 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2817 {
2818 error (invalid_op_diag);
2819 return error_mark_node;
2820 }
2821
2822 switch (code)
2823 {
2824 case CONVERT_EXPR:
2825 /* This is used for unary plus, because a CONVERT_EXPR
2826 is enough to prevent anybody from looking inside for
2827 associativity, but won't generate any code. */
2828 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2829 || typecode == COMPLEX_TYPE
2830 || typecode == VECTOR_TYPE))
2831 {
2832 error ("wrong type argument to unary plus");
2833 return error_mark_node;
2834 }
2835 else if (!noconvert)
2836 arg = default_conversion (arg);
2837 arg = non_lvalue (arg);
2838 break;
2839
2840 case NEGATE_EXPR:
2841 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2842 || typecode == COMPLEX_TYPE
2843 || typecode == VECTOR_TYPE))
2844 {
2845 error ("wrong type argument to unary minus");
2846 return error_mark_node;
2847 }
2848 else if (!noconvert)
2849 arg = default_conversion (arg);
2850 break;
2851
2852 case BIT_NOT_EXPR:
2853 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE)
2854 {
2855 if (!noconvert)
2856 arg = default_conversion (arg);
2857 }
2858 else if (typecode == COMPLEX_TYPE)
2859 {
2860 code = CONJ_EXPR;
2861 if (pedantic)
2862 pedwarn ("ISO C does not support %<~%> for complex conjugation");
2863 if (!noconvert)
2864 arg = default_conversion (arg);
2865 }
2866 else
2867 {
2868 error ("wrong type argument to bit-complement");
2869 return error_mark_node;
2870 }
2871 break;
2872
2873 case ABS_EXPR:
2874 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2875 {
2876 error ("wrong type argument to abs");
2877 return error_mark_node;
2878 }
2879 else if (!noconvert)
2880 arg = default_conversion (arg);
2881 break;
2882
2883 case CONJ_EXPR:
2884 /* Conjugating a real value is a no-op, but allow it anyway. */
2885 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2886 || typecode == COMPLEX_TYPE))
2887 {
2888 error ("wrong type argument to conjugation");
2889 return error_mark_node;
2890 }
2891 else if (!noconvert)
2892 arg = default_conversion (arg);
2893 break;
2894
2895 case TRUTH_NOT_EXPR:
2896 if (typecode != INTEGER_TYPE
2897 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2898 && typecode != COMPLEX_TYPE)
2899 {
2900 error ("wrong type argument to unary exclamation mark");
2901 return error_mark_node;
2902 }
2903 arg = c_objc_common_truthvalue_conversion (arg);
2904 return invert_truthvalue (arg);
2905
2906 case REALPART_EXPR:
2907 if (TREE_CODE (arg) == COMPLEX_CST)
2908 return TREE_REALPART (arg);
2909 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2910 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2911 else
2912 return arg;
2913
2914 case IMAGPART_EXPR:
2915 if (TREE_CODE (arg) == COMPLEX_CST)
2916 return TREE_IMAGPART (arg);
2917 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2918 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2919 else
2920 return convert (TREE_TYPE (arg), integer_zero_node);
2921
2922 case PREINCREMENT_EXPR:
2923 case POSTINCREMENT_EXPR:
2924 case PREDECREMENT_EXPR:
2925 case POSTDECREMENT_EXPR:
2926
2927 /* Increment or decrement the real part of the value,
2928 and don't change the imaginary part. */
2929 if (typecode == COMPLEX_TYPE)
2930 {
2931 tree real, imag;
2932
2933 if (pedantic)
2934 pedwarn ("ISO C does not support %<++%> and %<--%>"
2935 " on complex types");
2936
2937 arg = stabilize_reference (arg);
2938 real = build_unary_op (REALPART_EXPR, arg, 1);
2939 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2940 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
2941 build_unary_op (code, real, 1), imag);
2942 }
2943
2944 /* Report invalid types. */
2945
2946 if (typecode != POINTER_TYPE
2947 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2948 {
2949 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2950 error ("wrong type argument to increment");
2951 else
2952 error ("wrong type argument to decrement");
2953
2954 return error_mark_node;
2955 }
2956
2957 {
2958 tree inc;
2959 tree result_type = TREE_TYPE (arg);
2960
2961 arg = get_unwidened (arg, 0);
2962 argtype = TREE_TYPE (arg);
2963
2964 /* Compute the increment. */
2965
2966 if (typecode == POINTER_TYPE)
2967 {
2968 /* If pointer target is an undefined struct,
2969 we just cannot know how to do the arithmetic. */
2970 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2971 {
2972 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2973 error ("increment of pointer to unknown structure");
2974 else
2975 error ("decrement of pointer to unknown structure");
2976 }
2977 else if ((pedantic || warn_pointer_arith)
2978 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2979 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2980 {
2981 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2982 pedwarn ("wrong type argument to increment");
2983 else
2984 pedwarn ("wrong type argument to decrement");
2985 }
2986
2987 inc = c_size_in_bytes (TREE_TYPE (result_type));
2988 }
2989 else
2990 inc = integer_one_node;
2991
2992 inc = convert (argtype, inc);
2993
2994 /* Complain about anything else that is not a true lvalue. */
2995 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
2996 || code == POSTINCREMENT_EXPR)
2997 ? lv_increment
2998 : lv_decrement)))
2999 return error_mark_node;
3000
3001 /* Report a read-only lvalue. */
3002 if (TREE_READONLY (arg))
3003 {
3004 readonly_error (arg,
3005 ((code == PREINCREMENT_EXPR
3006 || code == POSTINCREMENT_EXPR)
3007 ? lv_increment : lv_decrement));
3008 return error_mark_node;
3009 }
3010
3011 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3012 val = boolean_increment (code, arg);
3013 else
3014 val = build2 (code, TREE_TYPE (arg), arg, inc);
3015 TREE_SIDE_EFFECTS (val) = 1;
3016 val = convert (result_type, val);
3017 if (TREE_CODE (val) != code)
3018 TREE_NO_WARNING (val) = 1;
3019 return val;
3020 }
3021
3022 case ADDR_EXPR:
3023 /* Note that this operation never does default_conversion. */
3024
3025 /* Let &* cancel out to simplify resulting code. */
3026 if (TREE_CODE (arg) == INDIRECT_REF)
3027 {
3028 /* Don't let this be an lvalue. */
3029 if (lvalue_p (TREE_OPERAND (arg, 0)))
3030 return non_lvalue (TREE_OPERAND (arg, 0));
3031 return TREE_OPERAND (arg, 0);
3032 }
3033
3034 /* For &x[y], return x+y */
3035 if (TREE_CODE (arg) == ARRAY_REF)
3036 {
3037 tree op0 = TREE_OPERAND (arg, 0);
3038 if (!c_mark_addressable (op0))
3039 return error_mark_node;
3040 return build_binary_op (PLUS_EXPR,
3041 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
3042 ? array_to_pointer_conversion (op0)
3043 : op0),
3044 TREE_OPERAND (arg, 1), 1);
3045 }
3046
3047 /* Anything not already handled and not a true memory reference
3048 or a non-lvalue array is an error. */
3049 else if (typecode != FUNCTION_TYPE && !flag
3050 && !lvalue_or_else (arg, lv_addressof))
3051 return error_mark_node;
3052
3053 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3054 argtype = TREE_TYPE (arg);
3055
3056 /* If the lvalue is const or volatile, merge that into the type
3057 to which the address will point. Note that you can't get a
3058 restricted pointer by taking the address of something, so we
3059 only have to deal with `const' and `volatile' here. */
3060 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3061 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3062 argtype = c_build_type_variant (argtype,
3063 TREE_READONLY (arg),
3064 TREE_THIS_VOLATILE (arg));
3065
3066 if (!c_mark_addressable (arg))
3067 return error_mark_node;
3068
3069 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3070 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3071
3072 argtype = build_pointer_type (argtype);
3073
3074 /* ??? Cope with user tricks that amount to offsetof. Delete this
3075 when we have proper support for integer constant expressions. */
3076 val = get_base_address (arg);
3077 if (val && TREE_CODE (val) == INDIRECT_REF
3078 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3079 {
3080 tree op0 = fold_convert (argtype, fold_offsetof (arg, val)), op1;
3081
3082 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3083 return fold_build2 (PLUS_EXPR, argtype, op0, op1);
3084 }
3085
3086 val = build1 (ADDR_EXPR, argtype, arg);
3087
3088 return val;
3089
3090 default:
3091 gcc_unreachable ();
3092 }
3093
3094 if (argtype == 0)
3095 argtype = TREE_TYPE (arg);
3096 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3097 : fold_build1 (code, argtype, arg);
3098 }
3099
3100 /* Return nonzero if REF is an lvalue valid for this language.
3101 Lvalues can be assigned, unless their type has TYPE_READONLY.
3102 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3103
3104 static int
lvalue_p(tree ref)3105 lvalue_p (tree ref)
3106 {
3107 enum tree_code code = TREE_CODE (ref);
3108
3109 switch (code)
3110 {
3111 case REALPART_EXPR:
3112 case IMAGPART_EXPR:
3113 case COMPONENT_REF:
3114 return lvalue_p (TREE_OPERAND (ref, 0));
3115
3116 case COMPOUND_LITERAL_EXPR:
3117 case STRING_CST:
3118 return 1;
3119
3120 case INDIRECT_REF:
3121 case ARRAY_REF:
3122 case VAR_DECL:
3123 case PARM_DECL:
3124 case RESULT_DECL:
3125 case ERROR_MARK:
3126 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3127 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3128
3129 case BIND_EXPR:
3130 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3131
3132 default:
3133 return 0;
3134 }
3135 }
3136
3137 /* Give an error for storing in something that is 'const'. */
3138
3139 static void
readonly_error(tree arg,enum lvalue_use use)3140 readonly_error (tree arg, enum lvalue_use use)
3141 {
3142 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3143 || use == lv_asm);
3144 /* Using this macro rather than (for example) arrays of messages
3145 ensures that all the format strings are checked at compile
3146 time. */
3147 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3148 : (use == lv_increment ? (I) \
3149 : (use == lv_decrement ? (D) : (AS))))
3150 if (TREE_CODE (arg) == COMPONENT_REF)
3151 {
3152 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3153 readonly_error (TREE_OPERAND (arg, 0), use);
3154 else
3155 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3156 G_("increment of read-only member %qD"),
3157 G_("decrement of read-only member %qD"),
3158 G_("read-only member %qD used as %<asm%> output")),
3159 TREE_OPERAND (arg, 1));
3160 }
3161 else if (TREE_CODE (arg) == VAR_DECL)
3162 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3163 G_("increment of read-only variable %qD"),
3164 G_("decrement of read-only variable %qD"),
3165 G_("read-only variable %qD used as %<asm%> output")),
3166 arg);
3167 else
3168 error (READONLY_MSG (G_("assignment of read-only location"),
3169 G_("increment of read-only location"),
3170 G_("decrement of read-only location"),
3171 G_("read-only location used as %<asm%> output")));
3172 }
3173
3174
3175 /* Return nonzero if REF is an lvalue valid for this language;
3176 otherwise, print an error message and return zero. USE says
3177 how the lvalue is being used and so selects the error message. */
3178
3179 static int
lvalue_or_else(tree ref,enum lvalue_use use)3180 lvalue_or_else (tree ref, enum lvalue_use use)
3181 {
3182 int win = lvalue_p (ref);
3183
3184 if (!win)
3185 lvalue_error (use);
3186
3187 return win;
3188 }
3189
3190 /* Mark EXP saying that we need to be able to take the
3191 address of it; it should not be allocated in a register.
3192 Returns true if successful. */
3193
3194 bool
c_mark_addressable(tree exp)3195 c_mark_addressable (tree exp)
3196 {
3197 tree x = exp;
3198
3199 while (1)
3200 switch (TREE_CODE (x))
3201 {
3202 case COMPONENT_REF:
3203 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3204 {
3205 error
3206 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3207 return false;
3208 }
3209
3210 /* ... fall through ... */
3211
3212 case ADDR_EXPR:
3213 case ARRAY_REF:
3214 case REALPART_EXPR:
3215 case IMAGPART_EXPR:
3216 x = TREE_OPERAND (x, 0);
3217 break;
3218
3219 case COMPOUND_LITERAL_EXPR:
3220 case CONSTRUCTOR:
3221 TREE_ADDRESSABLE (x) = 1;
3222 return true;
3223
3224 case VAR_DECL:
3225 case CONST_DECL:
3226 case PARM_DECL:
3227 case RESULT_DECL:
3228 if (C_DECL_REGISTER (x)
3229 && DECL_NONLOCAL (x))
3230 {
3231 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3232 {
3233 error
3234 ("global register variable %qD used in nested function", x);
3235 return false;
3236 }
3237 pedwarn ("register variable %qD used in nested function", x);
3238 }
3239 else if (C_DECL_REGISTER (x))
3240 {
3241 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3242 error ("address of global register variable %qD requested", x);
3243 else
3244 error ("address of register variable %qD requested", x);
3245 return false;
3246 }
3247
3248 /* drops in */
3249 case FUNCTION_DECL:
3250 TREE_ADDRESSABLE (x) = 1;
3251 /* drops out */
3252 default:
3253 return true;
3254 }
3255 }
3256
3257 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3258
3259 tree
build_conditional_expr(tree ifexp,tree op1,tree op2)3260 build_conditional_expr (tree ifexp, tree op1, tree op2)
3261 {
3262 tree type1;
3263 tree type2;
3264 enum tree_code code1;
3265 enum tree_code code2;
3266 tree result_type = NULL;
3267 tree orig_op1 = op1, orig_op2 = op2;
3268
3269 /* Promote both alternatives. */
3270
3271 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3272 op1 = default_conversion (op1);
3273 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3274 op2 = default_conversion (op2);
3275
3276 if (TREE_CODE (ifexp) == ERROR_MARK
3277 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3278 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3279 return error_mark_node;
3280
3281 type1 = TREE_TYPE (op1);
3282 code1 = TREE_CODE (type1);
3283 type2 = TREE_TYPE (op2);
3284 code2 = TREE_CODE (type2);
3285
3286 /* C90 does not permit non-lvalue arrays in conditional expressions.
3287 In C99 they will be pointers by now. */
3288 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3289 {
3290 error ("non-lvalue array in conditional expression");
3291 return error_mark_node;
3292 }
3293
3294 /* Quickly detect the usual case where op1 and op2 have the same type
3295 after promotion. */
3296 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3297 {
3298 if (type1 == type2)
3299 result_type = type1;
3300 else
3301 result_type = TYPE_MAIN_VARIANT (type1);
3302 }
3303 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3304 || code1 == COMPLEX_TYPE)
3305 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3306 || code2 == COMPLEX_TYPE))
3307 {
3308 result_type = c_common_type (type1, type2);
3309
3310 /* If -Wsign-compare, warn here if type1 and type2 have
3311 different signedness. We'll promote the signed to unsigned
3312 and later code won't know it used to be different.
3313 Do this check on the original types, so that explicit casts
3314 will be considered, but default promotions won't. */
3315 if (warn_sign_compare && !skip_evaluation)
3316 {
3317 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3318 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3319
3320 if (unsigned_op1 ^ unsigned_op2)
3321 {
3322 bool ovf;
3323
3324 /* Do not warn if the result type is signed, since the
3325 signed type will only be chosen if it can represent
3326 all the values of the unsigned type. */
3327 if (!TYPE_UNSIGNED (result_type))
3328 /* OK */;
3329 /* Do not warn if the signed quantity is an unsuffixed
3330 integer literal (or some static constant expression
3331 involving such literals) and it is non-negative. */
3332 else if ((unsigned_op2
3333 && tree_expr_nonnegative_warnv_p (op1, &ovf))
3334 || (unsigned_op1
3335 && tree_expr_nonnegative_warnv_p (op2, &ovf)))
3336 /* OK */;
3337 else
3338 warning (0, "signed and unsigned type in conditional expression");
3339 }
3340 }
3341 }
3342 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3343 {
3344 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3345 pedwarn ("ISO C forbids conditional expr with only one void side");
3346 result_type = void_type_node;
3347 }
3348 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3349 {
3350 if (comp_target_types (type1, type2))
3351 result_type = common_pointer_type (type1, type2);
3352 else if (null_pointer_constant_p (orig_op1))
3353 result_type = qualify_type (type2, type1);
3354 else if (null_pointer_constant_p (orig_op2))
3355 result_type = qualify_type (type1, type2);
3356 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3357 {
3358 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3359 pedwarn ("ISO C forbids conditional expr between "
3360 "%<void *%> and function pointer");
3361 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3362 TREE_TYPE (type2)));
3363 }
3364 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3365 {
3366 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3367 pedwarn ("ISO C forbids conditional expr between "
3368 "%<void *%> and function pointer");
3369 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3370 TREE_TYPE (type1)));
3371 }
3372 else
3373 {
3374 pedwarn ("pointer type mismatch in conditional expression");
3375 result_type = build_pointer_type (void_type_node);
3376 }
3377 }
3378 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3379 {
3380 if (!null_pointer_constant_p (orig_op2))
3381 pedwarn ("pointer/integer type mismatch in conditional expression");
3382 else
3383 {
3384 op2 = null_pointer_node;
3385 }
3386 result_type = type1;
3387 }
3388 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3389 {
3390 if (!null_pointer_constant_p (orig_op1))
3391 pedwarn ("pointer/integer type mismatch in conditional expression");
3392 else
3393 {
3394 op1 = null_pointer_node;
3395 }
3396 result_type = type2;
3397 }
3398
3399 if (!result_type)
3400 {
3401 if (flag_cond_mismatch)
3402 result_type = void_type_node;
3403 else
3404 {
3405 error ("type mismatch in conditional expression");
3406 return error_mark_node;
3407 }
3408 }
3409
3410 /* Merge const and volatile flags of the incoming types. */
3411 result_type
3412 = build_type_variant (result_type,
3413 TREE_READONLY (op1) || TREE_READONLY (op2),
3414 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3415
3416 if (result_type != TREE_TYPE (op1))
3417 op1 = convert_and_check (result_type, op1);
3418 if (result_type != TREE_TYPE (op2))
3419 op2 = convert_and_check (result_type, op2);
3420
3421 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3422 }
3423
3424 /* Return a compound expression that performs two expressions and
3425 returns the value of the second of them. */
3426
3427 tree
build_compound_expr(tree expr1,tree expr2)3428 build_compound_expr (tree expr1, tree expr2)
3429 {
3430 if (!TREE_SIDE_EFFECTS (expr1))
3431 {
3432 /* The left-hand operand of a comma expression is like an expression
3433 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3434 any side-effects, unless it was explicitly cast to (void). */
3435 if (warn_unused_value)
3436 {
3437 if (VOID_TYPE_P (TREE_TYPE (expr1))
3438 && (TREE_CODE (expr1) == NOP_EXPR
3439 || TREE_CODE (expr1) == CONVERT_EXPR))
3440 ; /* (void) a, b */
3441 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3442 && TREE_CODE (expr1) == COMPOUND_EXPR
3443 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR
3444 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR))
3445 ; /* (void) a, (void) b, c */
3446 else
3447 warning (0, "left-hand operand of comma expression has no effect");
3448 }
3449 }
3450
3451 /* With -Wunused, we should also warn if the left-hand operand does have
3452 side-effects, but computes a value which is not used. For example, in
3453 `foo() + bar(), baz()' the result of the `+' operator is not used,
3454 so we should issue a warning. */
3455 else if (warn_unused_value)
3456 warn_if_unused_value (expr1, input_location);
3457
3458 if (expr2 == error_mark_node)
3459 return error_mark_node;
3460
3461 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3462 }
3463
3464 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3465
3466 tree
build_c_cast(tree type,tree expr)3467 build_c_cast (tree type, tree expr)
3468 {
3469 tree value = expr;
3470
3471 if (type == error_mark_node || expr == error_mark_node)
3472 return error_mark_node;
3473
3474 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3475 only in <protocol> qualifications. But when constructing cast expressions,
3476 the protocols do matter and must be kept around. */
3477 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3478 return build1 (NOP_EXPR, type, expr);
3479
3480 type = TYPE_MAIN_VARIANT (type);
3481
3482 if (TREE_CODE (type) == ARRAY_TYPE)
3483 {
3484 error ("cast specifies array type");
3485 return error_mark_node;
3486 }
3487
3488 if (TREE_CODE (type) == FUNCTION_TYPE)
3489 {
3490 error ("cast specifies function type");
3491 return error_mark_node;
3492 }
3493
3494 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3495 {
3496 if (pedantic)
3497 {
3498 if (TREE_CODE (type) == RECORD_TYPE
3499 || TREE_CODE (type) == UNION_TYPE)
3500 pedwarn ("ISO C forbids casting nonscalar to the same type");
3501 }
3502 }
3503 else if (TREE_CODE (type) == UNION_TYPE)
3504 {
3505 tree field;
3506
3507 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3508 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3509 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3510 break;
3511
3512 if (field)
3513 {
3514 tree t;
3515
3516 if (pedantic)
3517 pedwarn ("ISO C forbids casts to union type");
3518 t = digest_init (type,
3519 build_constructor_single (type, field, value),
3520 true, 0);
3521 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3522 TREE_INVARIANT (t) = TREE_INVARIANT (value);
3523 return t;
3524 }
3525 error ("cast to union type from type not present in union");
3526 return error_mark_node;
3527 }
3528 else
3529 {
3530 tree otype, ovalue;
3531
3532 if (type == void_type_node)
3533 return build1 (CONVERT_EXPR, type, value);
3534
3535 otype = TREE_TYPE (value);
3536
3537 /* Optionally warn about potentially worrisome casts. */
3538
3539 if (warn_cast_qual
3540 && TREE_CODE (type) == POINTER_TYPE
3541 && TREE_CODE (otype) == POINTER_TYPE)
3542 {
3543 tree in_type = type;
3544 tree in_otype = otype;
3545 int added = 0;
3546 int discarded = 0;
3547
3548 /* Check that the qualifiers on IN_TYPE are a superset of
3549 the qualifiers of IN_OTYPE. The outermost level of
3550 POINTER_TYPE nodes is uninteresting and we stop as soon
3551 as we hit a non-POINTER_TYPE node on either type. */
3552 do
3553 {
3554 in_otype = TREE_TYPE (in_otype);
3555 in_type = TREE_TYPE (in_type);
3556
3557 /* GNU C allows cv-qualified function types. 'const'
3558 means the function is very pure, 'volatile' means it
3559 can't return. We need to warn when such qualifiers
3560 are added, not when they're taken away. */
3561 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3562 && TREE_CODE (in_type) == FUNCTION_TYPE)
3563 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3564 else
3565 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3566 }
3567 while (TREE_CODE (in_type) == POINTER_TYPE
3568 && TREE_CODE (in_otype) == POINTER_TYPE);
3569
3570 if (added)
3571 warning (0, "cast adds new qualifiers to function type");
3572
3573 if (discarded)
3574 /* There are qualifiers present in IN_OTYPE that are not
3575 present in IN_TYPE. */
3576 warning (0, "cast discards qualifiers from pointer target type");
3577 }
3578
3579 /* Warn about possible alignment problems. */
3580 if (STRICT_ALIGNMENT
3581 && TREE_CODE (type) == POINTER_TYPE
3582 && TREE_CODE (otype) == POINTER_TYPE
3583 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3584 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3585 /* Don't warn about opaque types, where the actual alignment
3586 restriction is unknown. */
3587 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3588 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3589 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3590 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3591 warning (OPT_Wcast_align,
3592 "cast increases required alignment of target type");
3593
3594 if (TREE_CODE (type) == INTEGER_TYPE
3595 && TREE_CODE (otype) == POINTER_TYPE
3596 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3597 /* Unlike conversion of integers to pointers, where the
3598 warning is disabled for converting constants because
3599 of cases such as SIG_*, warn about converting constant
3600 pointers to integers. In some cases it may cause unwanted
3601 sign extension, and a warning is appropriate. */
3602 warning (OPT_Wpointer_to_int_cast,
3603 "cast from pointer to integer of different size");
3604
3605 if (TREE_CODE (value) == CALL_EXPR
3606 && TREE_CODE (type) != TREE_CODE (otype))
3607 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3608 "to non-matching type %qT", otype, type);
3609
3610 if (TREE_CODE (type) == POINTER_TYPE
3611 && TREE_CODE (otype) == INTEGER_TYPE
3612 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3613 /* Don't warn about converting any constant. */
3614 && !TREE_CONSTANT (value))
3615 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3616 "of different size");
3617
3618 strict_aliasing_warning (otype, type, expr);
3619
3620 /* If pedantic, warn for conversions between function and object
3621 pointer types, except for converting a null pointer constant
3622 to function pointer type. */
3623 if (pedantic
3624 && TREE_CODE (type) == POINTER_TYPE
3625 && TREE_CODE (otype) == POINTER_TYPE
3626 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3627 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3628 pedwarn ("ISO C forbids conversion of function pointer to object pointer type");
3629
3630 if (pedantic
3631 && TREE_CODE (type) == POINTER_TYPE
3632 && TREE_CODE (otype) == POINTER_TYPE
3633 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3634 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3635 && !null_pointer_constant_p (value))
3636 pedwarn ("ISO C forbids conversion of object pointer to function pointer type");
3637
3638 ovalue = value;
3639 value = convert (type, value);
3640
3641 /* Ignore any integer overflow caused by the cast. */
3642 if (TREE_CODE (value) == INTEGER_CST)
3643 {
3644 if (CONSTANT_CLASS_P (ovalue)
3645 && (TREE_OVERFLOW (ovalue) || TREE_CONSTANT_OVERFLOW (ovalue)))
3646 {
3647 /* Avoid clobbering a shared constant. */
3648 value = copy_node (value);
3649 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3650 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
3651 }
3652 else if (TREE_OVERFLOW (value) || TREE_CONSTANT_OVERFLOW (value))
3653 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3654 value = build_int_cst_wide (TREE_TYPE (value),
3655 TREE_INT_CST_LOW (value),
3656 TREE_INT_CST_HIGH (value));
3657 }
3658 }
3659
3660 /* Don't let a cast be an lvalue. */
3661 if (value == expr)
3662 value = non_lvalue (value);
3663
3664 return value;
3665 }
3666
3667 /* Interpret a cast of expression EXPR to type TYPE. */
3668 tree
c_cast_expr(struct c_type_name * type_name,tree expr)3669 c_cast_expr (struct c_type_name *type_name, tree expr)
3670 {
3671 tree type;
3672 int saved_wsp = warn_strict_prototypes;
3673
3674 /* This avoids warnings about unprototyped casts on
3675 integers. E.g. "#define SIG_DFL (void(*)())0". */
3676 if (TREE_CODE (expr) == INTEGER_CST)
3677 warn_strict_prototypes = 0;
3678 type = groktypename (type_name);
3679 warn_strict_prototypes = saved_wsp;
3680
3681 return build_c_cast (type, expr);
3682 }
3683
3684 /* Build an assignment expression of lvalue LHS from value RHS.
3685 MODIFYCODE is the code for a binary operator that we use
3686 to combine the old value of LHS with RHS to get the new value.
3687 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3688
3689 tree
build_modify_expr(tree lhs,enum tree_code modifycode,tree rhs)3690 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3691 {
3692 tree result;
3693 tree newrhs;
3694 tree lhstype = TREE_TYPE (lhs);
3695 tree olhstype = lhstype;
3696
3697 /* Types that aren't fully specified cannot be used in assignments. */
3698 lhs = require_complete_type (lhs);
3699
3700 /* Avoid duplicate error messages from operands that had errors. */
3701 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3702 return error_mark_node;
3703
3704 if (!lvalue_or_else (lhs, lv_assign))
3705 return error_mark_node;
3706
3707 STRIP_TYPE_NOPS (rhs);
3708
3709 newrhs = rhs;
3710
3711 /* If a binary op has been requested, combine the old LHS value with the RHS
3712 producing the value we should actually store into the LHS. */
3713
3714 if (modifycode != NOP_EXPR)
3715 {
3716 lhs = stabilize_reference (lhs);
3717 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3718 }
3719
3720 /* Give an error for storing in something that is 'const'. */
3721
3722 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3723 || ((TREE_CODE (lhstype) == RECORD_TYPE
3724 || TREE_CODE (lhstype) == UNION_TYPE)
3725 && C_TYPE_FIELDS_READONLY (lhstype)))
3726 {
3727 readonly_error (lhs, lv_assign);
3728 return error_mark_node;
3729 }
3730
3731 /* If storing into a structure or union member,
3732 it has probably been given type `int'.
3733 Compute the type that would go with
3734 the actual amount of storage the member occupies. */
3735
3736 if (TREE_CODE (lhs) == COMPONENT_REF
3737 && (TREE_CODE (lhstype) == INTEGER_TYPE
3738 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3739 || TREE_CODE (lhstype) == REAL_TYPE
3740 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3741 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3742
3743 /* If storing in a field that is in actuality a short or narrower than one,
3744 we must store in the field in its actual type. */
3745
3746 if (lhstype != TREE_TYPE (lhs))
3747 {
3748 lhs = copy_node (lhs);
3749 TREE_TYPE (lhs) = lhstype;
3750 }
3751
3752 /* Convert new value to destination type. */
3753
3754 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3755 NULL_TREE, NULL_TREE, 0);
3756 if (TREE_CODE (newrhs) == ERROR_MARK)
3757 return error_mark_node;
3758
3759 /* Emit ObjC write barrier, if necessary. */
3760 if (c_dialect_objc () && flag_objc_gc)
3761 {
3762 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3763 if (result)
3764 return result;
3765 }
3766
3767 /* Scan operands. */
3768
3769 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3770 TREE_SIDE_EFFECTS (result) = 1;
3771
3772 /* If we got the LHS in a different type for storing in,
3773 convert the result back to the nominal type of LHS
3774 so that the value we return always has the same type
3775 as the LHS argument. */
3776
3777 if (olhstype == TREE_TYPE (result))
3778 return result;
3779 return convert_for_assignment (olhstype, result, ic_assign,
3780 NULL_TREE, NULL_TREE, 0);
3781 }
3782
3783 /* Convert value RHS to type TYPE as preparation for an assignment
3784 to an lvalue of type TYPE.
3785 The real work of conversion is done by `convert'.
3786 The purpose of this function is to generate error messages
3787 for assignments that are not allowed in C.
3788 ERRTYPE says whether it is argument passing, assignment,
3789 initialization or return.
3790
3791 FUNCTION is a tree for the function being called.
3792 PARMNUM is the number of the argument, for printing in error messages. */
3793
3794 static tree
convert_for_assignment(tree type,tree rhs,enum impl_conv errtype,tree fundecl,tree function,int parmnum)3795 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3796 tree fundecl, tree function, int parmnum)
3797 {
3798 enum tree_code codel = TREE_CODE (type);
3799 tree rhstype;
3800 enum tree_code coder;
3801 tree rname = NULL_TREE;
3802 bool objc_ok = false;
3803
3804 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3805 {
3806 tree selector;
3807 /* Change pointer to function to the function itself for
3808 diagnostics. */
3809 if (TREE_CODE (function) == ADDR_EXPR
3810 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3811 function = TREE_OPERAND (function, 0);
3812
3813 /* Handle an ObjC selector specially for diagnostics. */
3814 selector = objc_message_selector ();
3815 rname = function;
3816 if (selector && parmnum > 2)
3817 {
3818 rname = selector;
3819 parmnum -= 2;
3820 }
3821 }
3822
3823 /* This macro is used to emit diagnostics to ensure that all format
3824 strings are complete sentences, visible to gettext and checked at
3825 compile time. */
3826 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3827 do { \
3828 switch (errtype) \
3829 { \
3830 case ic_argpass: \
3831 pedwarn (AR, parmnum, rname); \
3832 break; \
3833 case ic_argpass_nonproto: \
3834 warning (0, AR, parmnum, rname); \
3835 break; \
3836 case ic_assign: \
3837 pedwarn (AS); \
3838 break; \
3839 case ic_init: \
3840 pedwarn (IN); \
3841 break; \
3842 case ic_return: \
3843 pedwarn (RE); \
3844 break; \
3845 default: \
3846 gcc_unreachable (); \
3847 } \
3848 } while (0)
3849
3850 STRIP_TYPE_NOPS (rhs);
3851
3852 if (optimize && TREE_CODE (rhs) == VAR_DECL
3853 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
3854 rhs = decl_constant_value_for_broken_optimization (rhs);
3855
3856 rhstype = TREE_TYPE (rhs);
3857 coder = TREE_CODE (rhstype);
3858
3859 if (coder == ERROR_MARK)
3860 return error_mark_node;
3861
3862 if (c_dialect_objc ())
3863 {
3864 int parmno;
3865
3866 switch (errtype)
3867 {
3868 case ic_return:
3869 parmno = 0;
3870 break;
3871
3872 case ic_assign:
3873 parmno = -1;
3874 break;
3875
3876 case ic_init:
3877 parmno = -2;
3878 break;
3879
3880 default:
3881 parmno = parmnum;
3882 break;
3883 }
3884
3885 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
3886 }
3887
3888 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
3889 {
3890 overflow_warning (rhs);
3891 return rhs;
3892 }
3893
3894 if (coder == VOID_TYPE)
3895 {
3896 /* Except for passing an argument to an unprototyped function,
3897 this is a constraint violation. When passing an argument to
3898 an unprototyped function, it is compile-time undefined;
3899 making it a constraint in that case was rejected in
3900 DR#252. */
3901 error ("void value not ignored as it ought to be");
3902 return error_mark_node;
3903 }
3904 /* A type converts to a reference to it.
3905 This code doesn't fully support references, it's just for the
3906 special case of va_start and va_copy. */
3907 if (codel == REFERENCE_TYPE
3908 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
3909 {
3910 if (!lvalue_p (rhs))
3911 {
3912 error ("cannot pass rvalue to reference parameter");
3913 return error_mark_node;
3914 }
3915 if (!c_mark_addressable (rhs))
3916 return error_mark_node;
3917 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
3918
3919 /* We already know that these two types are compatible, but they
3920 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3921 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3922 likely to be va_list, a typedef to __builtin_va_list, which
3923 is different enough that it will cause problems later. */
3924 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
3925 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
3926
3927 rhs = build1 (NOP_EXPR, type, rhs);
3928 return rhs;
3929 }
3930 /* Some types can interconvert without explicit casts. */
3931 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
3932 && vector_types_convertible_p (type, TREE_TYPE (rhs)))
3933 return convert (type, rhs);
3934 /* Arithmetic types all interconvert, and enum is treated like int. */
3935 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
3936 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
3937 || codel == BOOLEAN_TYPE)
3938 && (coder == INTEGER_TYPE || coder == REAL_TYPE
3939 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
3940 || coder == BOOLEAN_TYPE))
3941 return convert_and_check (type, rhs);
3942
3943 /* Aggregates in different TUs might need conversion. */
3944 if ((codel == RECORD_TYPE || codel == UNION_TYPE)
3945 && codel == coder
3946 && comptypes (type, rhstype))
3947 return convert_and_check (type, rhs);
3948
3949 /* Conversion to a transparent union from its member types.
3950 This applies only to function arguments. */
3951 if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
3952 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
3953 {
3954 tree memb, marginal_memb = NULL_TREE;
3955
3956 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
3957 {
3958 tree memb_type = TREE_TYPE (memb);
3959
3960 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
3961 TYPE_MAIN_VARIANT (rhstype)))
3962 break;
3963
3964 if (TREE_CODE (memb_type) != POINTER_TYPE)
3965 continue;
3966
3967 if (coder == POINTER_TYPE)
3968 {
3969 tree ttl = TREE_TYPE (memb_type);
3970 tree ttr = TREE_TYPE (rhstype);
3971
3972 /* Any non-function converts to a [const][volatile] void *
3973 and vice versa; otherwise, targets must be the same.
3974 Meanwhile, the lhs target must have all the qualifiers of
3975 the rhs. */
3976 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
3977 || comp_target_types (memb_type, rhstype))
3978 {
3979 /* If this type won't generate any warnings, use it. */
3980 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
3981 || ((TREE_CODE (ttr) == FUNCTION_TYPE
3982 && TREE_CODE (ttl) == FUNCTION_TYPE)
3983 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3984 == TYPE_QUALS (ttr))
3985 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3986 == TYPE_QUALS (ttl))))
3987 break;
3988
3989 /* Keep looking for a better type, but remember this one. */
3990 if (!marginal_memb)
3991 marginal_memb = memb;
3992 }
3993 }
3994
3995 /* Can convert integer zero to any pointer type. */
3996 if (null_pointer_constant_p (rhs))
3997 {
3998 rhs = null_pointer_node;
3999 break;
4000 }
4001 }
4002
4003 if (memb || marginal_memb)
4004 {
4005 if (!memb)
4006 {
4007 /* We have only a marginally acceptable member type;
4008 it needs a warning. */
4009 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
4010 tree ttr = TREE_TYPE (rhstype);
4011
4012 /* Const and volatile mean something different for function
4013 types, so the usual warnings are not appropriate. */
4014 if (TREE_CODE (ttr) == FUNCTION_TYPE
4015 && TREE_CODE (ttl) == FUNCTION_TYPE)
4016 {
4017 /* Because const and volatile on functions are
4018 restrictions that say the function will not do
4019 certain things, it is okay to use a const or volatile
4020 function where an ordinary one is wanted, but not
4021 vice-versa. */
4022 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4023 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE "
4024 "makes qualified function "
4025 "pointer from unqualified"),
4026 G_("assignment makes qualified "
4027 "function pointer from "
4028 "unqualified"),
4029 G_("initialization makes qualified "
4030 "function pointer from "
4031 "unqualified"),
4032 G_("return makes qualified function "
4033 "pointer from unqualified"));
4034 }
4035 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4036 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4037 "qualifiers from pointer target type"),
4038 G_("assignment discards qualifiers "
4039 "from pointer target type"),
4040 G_("initialization discards qualifiers "
4041 "from pointer target type"),
4042 G_("return discards qualifiers from "
4043 "pointer target type"));
4044
4045 memb = marginal_memb;
4046 }
4047
4048 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl)))
4049 pedwarn ("ISO C prohibits argument conversion to union type");
4050
4051 return build_constructor_single (type, memb, rhs);
4052 }
4053 }
4054
4055 /* Conversions among pointers */
4056 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4057 && (coder == codel))
4058 {
4059 tree ttl = TREE_TYPE (type);
4060 tree ttr = TREE_TYPE (rhstype);
4061 tree mvl = ttl;
4062 tree mvr = ttr;
4063 bool is_opaque_pointer;
4064 int target_cmp = 0; /* Cache comp_target_types () result. */
4065
4066 if (TREE_CODE (mvl) != ARRAY_TYPE)
4067 mvl = TYPE_MAIN_VARIANT (mvl);
4068 if (TREE_CODE (mvr) != ARRAY_TYPE)
4069 mvr = TYPE_MAIN_VARIANT (mvr);
4070 /* Opaque pointers are treated like void pointers. */
4071 is_opaque_pointer = (targetm.vector_opaque_p (type)
4072 || targetm.vector_opaque_p (rhstype))
4073 && TREE_CODE (ttl) == VECTOR_TYPE
4074 && TREE_CODE (ttr) == VECTOR_TYPE;
4075
4076 /* C++ does not allow the implicit conversion void* -> T*. However,
4077 for the purpose of reducing the number of false positives, we
4078 tolerate the special case of
4079
4080 int *p = NULL;
4081
4082 where NULL is typically defined in C to be '(void *) 0'. */
4083 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4084 warning (OPT_Wc___compat, "request for implicit conversion from "
4085 "%qT to %qT not permitted in C++", rhstype, type);
4086
4087 /* Check if the right-hand side has a format attribute but the
4088 left-hand side doesn't. */
4089 if (warn_missing_format_attribute
4090 && check_missing_format_attribute (type, rhstype))
4091 {
4092 switch (errtype)
4093 {
4094 case ic_argpass:
4095 case ic_argpass_nonproto:
4096 warning (OPT_Wmissing_format_attribute,
4097 "argument %d of %qE might be "
4098 "a candidate for a format attribute",
4099 parmnum, rname);
4100 break;
4101 case ic_assign:
4102 warning (OPT_Wmissing_format_attribute,
4103 "assignment left-hand side might be "
4104 "a candidate for a format attribute");
4105 break;
4106 case ic_init:
4107 warning (OPT_Wmissing_format_attribute,
4108 "initialization left-hand side might be "
4109 "a candidate for a format attribute");
4110 break;
4111 case ic_return:
4112 warning (OPT_Wmissing_format_attribute,
4113 "return type might be "
4114 "a candidate for a format attribute");
4115 break;
4116 default:
4117 gcc_unreachable ();
4118 }
4119 }
4120
4121 /* Any non-function converts to a [const][volatile] void *
4122 and vice versa; otherwise, targets must be the same.
4123 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4124 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4125 || (target_cmp = comp_target_types (type, rhstype))
4126 || is_opaque_pointer
4127 || (c_common_unsigned_type (mvl)
4128 == c_common_unsigned_type (mvr)))
4129 {
4130 if (pedantic
4131 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4132 ||
4133 (VOID_TYPE_P (ttr)
4134 && !null_pointer_constant_p (rhs)
4135 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4136 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of "
4137 "%qE between function pointer "
4138 "and %<void *%>"),
4139 G_("ISO C forbids assignment between "
4140 "function pointer and %<void *%>"),
4141 G_("ISO C forbids initialization between "
4142 "function pointer and %<void *%>"),
4143 G_("ISO C forbids return between function "
4144 "pointer and %<void *%>"));
4145 /* Const and volatile mean something different for function types,
4146 so the usual warnings are not appropriate. */
4147 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4148 && TREE_CODE (ttl) != FUNCTION_TYPE)
4149 {
4150 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4151 {
4152 /* Types differing only by the presence of the 'volatile'
4153 qualifier are acceptable if the 'volatile' has been added
4154 in by the Objective-C EH machinery. */
4155 if (!objc_type_quals_match (ttl, ttr))
4156 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4157 "qualifiers from pointer target type"),
4158 G_("assignment discards qualifiers "
4159 "from pointer target type"),
4160 G_("initialization discards qualifiers "
4161 "from pointer target type"),
4162 G_("return discards qualifiers from "
4163 "pointer target type"));
4164 }
4165 /* If this is not a case of ignoring a mismatch in signedness,
4166 no warning. */
4167 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4168 || target_cmp)
4169 ;
4170 /* If there is a mismatch, do warn. */
4171 else if (warn_pointer_sign)
4172 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument "
4173 "%d of %qE differ in signedness"),
4174 G_("pointer targets in assignment "
4175 "differ in signedness"),
4176 G_("pointer targets in initialization "
4177 "differ in signedness"),
4178 G_("pointer targets in return differ "
4179 "in signedness"));
4180 }
4181 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4182 && TREE_CODE (ttr) == FUNCTION_TYPE)
4183 {
4184 /* Because const and volatile on functions are restrictions
4185 that say the function will not do certain things,
4186 it is okay to use a const or volatile function
4187 where an ordinary one is wanted, but not vice-versa. */
4188 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4189 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4190 "qualified function pointer "
4191 "from unqualified"),
4192 G_("assignment makes qualified function "
4193 "pointer from unqualified"),
4194 G_("initialization makes qualified "
4195 "function pointer from unqualified"),
4196 G_("return makes qualified function "
4197 "pointer from unqualified"));
4198 }
4199 }
4200 else
4201 /* Avoid warning about the volatile ObjC EH puts on decls. */
4202 if (!objc_ok)
4203 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from "
4204 "incompatible pointer type"),
4205 G_("assignment from incompatible pointer type"),
4206 G_("initialization from incompatible "
4207 "pointer type"),
4208 G_("return from incompatible pointer type"));
4209
4210 return convert (type, rhs);
4211 }
4212 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4213 {
4214 /* ??? This should not be an error when inlining calls to
4215 unprototyped functions. */
4216 error ("invalid use of non-lvalue array");
4217 return error_mark_node;
4218 }
4219 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4220 {
4221 /* An explicit constant 0 can convert to a pointer,
4222 or one that results from arithmetic, even including
4223 a cast to integer type. */
4224 if (!null_pointer_constant_p (rhs))
4225 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4226 "pointer from integer without a cast"),
4227 G_("assignment makes pointer from integer "
4228 "without a cast"),
4229 G_("initialization makes pointer from "
4230 "integer without a cast"),
4231 G_("return makes pointer from integer "
4232 "without a cast"));
4233
4234 return convert (type, rhs);
4235 }
4236 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4237 {
4238 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer "
4239 "from pointer without a cast"),
4240 G_("assignment makes integer from pointer "
4241 "without a cast"),
4242 G_("initialization makes integer from pointer "
4243 "without a cast"),
4244 G_("return makes integer from pointer "
4245 "without a cast"));
4246 return convert (type, rhs);
4247 }
4248 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4249 return convert (type, rhs);
4250
4251 switch (errtype)
4252 {
4253 case ic_argpass:
4254 case ic_argpass_nonproto:
4255 /* ??? This should not be an error when inlining calls to
4256 unprototyped functions. */
4257 error ("incompatible type for argument %d of %qE", parmnum, rname);
4258 break;
4259 case ic_assign:
4260 error ("incompatible types in assignment");
4261 break;
4262 case ic_init:
4263 error ("incompatible types in initialization");
4264 break;
4265 case ic_return:
4266 error ("incompatible types in return");
4267 break;
4268 default:
4269 gcc_unreachable ();
4270 }
4271
4272 return error_mark_node;
4273 }
4274
4275 /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM
4276 is used for error and warning reporting and indicates which argument
4277 is being processed. */
4278
4279 tree
c_convert_parm_for_inlining(tree parm,tree value,tree fn,int argnum)4280 c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum)
4281 {
4282 tree ret, type;
4283
4284 /* If FN was prototyped at the call site, the value has been converted
4285 already in convert_arguments.
4286 However, we might see a prototype now that was not in place when
4287 the function call was seen, so check that the VALUE actually matches
4288 PARM before taking an early exit. */
4289 if (!value
4290 || (TYPE_ARG_TYPES (TREE_TYPE (fn))
4291 && (TYPE_MAIN_VARIANT (TREE_TYPE (parm))
4292 == TYPE_MAIN_VARIANT (TREE_TYPE (value)))))
4293 return value;
4294
4295 type = TREE_TYPE (parm);
4296 ret = convert_for_assignment (type, value,
4297 ic_argpass_nonproto, fn,
4298 fn, argnum);
4299 if (targetm.calls.promote_prototypes (TREE_TYPE (fn))
4300 && INTEGRAL_TYPE_P (type)
4301 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
4302 ret = default_conversion (ret);
4303 return ret;
4304 }
4305
4306 /* If VALUE is a compound expr all of whose expressions are constant, then
4307 return its value. Otherwise, return error_mark_node.
4308
4309 This is for handling COMPOUND_EXPRs as initializer elements
4310 which is allowed with a warning when -pedantic is specified. */
4311
4312 static tree
valid_compound_expr_initializer(tree value,tree endtype)4313 valid_compound_expr_initializer (tree value, tree endtype)
4314 {
4315 if (TREE_CODE (value) == COMPOUND_EXPR)
4316 {
4317 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4318 == error_mark_node)
4319 return error_mark_node;
4320 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4321 endtype);
4322 }
4323 else if (!initializer_constant_valid_p (value, endtype))
4324 return error_mark_node;
4325 else
4326 return value;
4327 }
4328
4329 /* Perform appropriate conversions on the initial value of a variable,
4330 store it in the declaration DECL,
4331 and print any error messages that are appropriate.
4332 If the init is invalid, store an ERROR_MARK. */
4333
4334 void
store_init_value(tree decl,tree init)4335 store_init_value (tree decl, tree init)
4336 {
4337 tree value, type;
4338
4339 /* If variable's type was invalidly declared, just ignore it. */
4340
4341 type = TREE_TYPE (decl);
4342 if (TREE_CODE (type) == ERROR_MARK)
4343 return;
4344
4345 /* Digest the specified initializer into an expression. */
4346
4347 value = digest_init (type, init, true, TREE_STATIC (decl));
4348
4349 /* Store the expression if valid; else report error. */
4350
4351 if (!in_system_header
4352 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4353 warning (OPT_Wtraditional, "traditional C rejects automatic "
4354 "aggregate initialization");
4355
4356 DECL_INITIAL (decl) = value;
4357
4358 /* ANSI wants warnings about out-of-range constant initializers. */
4359 STRIP_TYPE_NOPS (value);
4360 constant_expression_warning (value);
4361
4362 /* Check if we need to set array size from compound literal size. */
4363 if (TREE_CODE (type) == ARRAY_TYPE
4364 && TYPE_DOMAIN (type) == 0
4365 && value != error_mark_node)
4366 {
4367 tree inside_init = init;
4368
4369 STRIP_TYPE_NOPS (inside_init);
4370 inside_init = fold (inside_init);
4371
4372 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4373 {
4374 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4375
4376 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4377 {
4378 /* For int foo[] = (int [3]){1}; we need to set array size
4379 now since later on array initializer will be just the
4380 brace enclosed list of the compound literal. */
4381 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4382 TREE_TYPE (decl) = type;
4383 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4384 layout_type (type);
4385 layout_decl (cldecl, 0);
4386 }
4387 }
4388 }
4389 }
4390
4391 /* Methods for storing and printing names for error messages. */
4392
4393 /* Implement a spelling stack that allows components of a name to be pushed
4394 and popped. Each element on the stack is this structure. */
4395
4396 struct spelling
4397 {
4398 int kind;
4399 union
4400 {
4401 unsigned HOST_WIDE_INT i;
4402 const char *s;
4403 } u;
4404 };
4405
4406 #define SPELLING_STRING 1
4407 #define SPELLING_MEMBER 2
4408 #define SPELLING_BOUNDS 3
4409
4410 static struct spelling *spelling; /* Next stack element (unused). */
4411 static struct spelling *spelling_base; /* Spelling stack base. */
4412 static int spelling_size; /* Size of the spelling stack. */
4413
4414 /* Macros to save and restore the spelling stack around push_... functions.
4415 Alternative to SAVE_SPELLING_STACK. */
4416
4417 #define SPELLING_DEPTH() (spelling - spelling_base)
4418 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4419
4420 /* Push an element on the spelling stack with type KIND and assign VALUE
4421 to MEMBER. */
4422
4423 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4424 { \
4425 int depth = SPELLING_DEPTH (); \
4426 \
4427 if (depth >= spelling_size) \
4428 { \
4429 spelling_size += 10; \
4430 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4431 spelling_size); \
4432 RESTORE_SPELLING_DEPTH (depth); \
4433 } \
4434 \
4435 spelling->kind = (KIND); \
4436 spelling->MEMBER = (VALUE); \
4437 spelling++; \
4438 }
4439
4440 /* Push STRING on the stack. Printed literally. */
4441
4442 static void
push_string(const char * string)4443 push_string (const char *string)
4444 {
4445 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4446 }
4447
4448 /* Push a member name on the stack. Printed as '.' STRING. */
4449
4450 static void
push_member_name(tree decl)4451 push_member_name (tree decl)
4452 {
4453 const char *const string
4454 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4455 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4456 }
4457
4458 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4459
4460 static void
push_array_bounds(unsigned HOST_WIDE_INT bounds)4461 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4462 {
4463 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4464 }
4465
4466 /* Compute the maximum size in bytes of the printed spelling. */
4467
4468 static int
spelling_length(void)4469 spelling_length (void)
4470 {
4471 int size = 0;
4472 struct spelling *p;
4473
4474 for (p = spelling_base; p < spelling; p++)
4475 {
4476 if (p->kind == SPELLING_BOUNDS)
4477 size += 25;
4478 else
4479 size += strlen (p->u.s) + 1;
4480 }
4481
4482 return size;
4483 }
4484
4485 /* Print the spelling to BUFFER and return it. */
4486
4487 static char *
print_spelling(char * buffer)4488 print_spelling (char *buffer)
4489 {
4490 char *d = buffer;
4491 struct spelling *p;
4492
4493 for (p = spelling_base; p < spelling; p++)
4494 if (p->kind == SPELLING_BOUNDS)
4495 {
4496 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4497 d += strlen (d);
4498 }
4499 else
4500 {
4501 const char *s;
4502 if (p->kind == SPELLING_MEMBER)
4503 *d++ = '.';
4504 for (s = p->u.s; (*d = *s++); d++)
4505 ;
4506 }
4507 *d++ = '\0';
4508 return buffer;
4509 }
4510
4511 /* Issue an error message for a bad initializer component.
4512 MSGID identifies the message.
4513 The component name is taken from the spelling stack. */
4514
4515 void
error_init(const char * msgid)4516 error_init (const char *msgid)
4517 {
4518 char *ofwhat;
4519
4520 error ("%s", _(msgid));
4521 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4522 if (*ofwhat)
4523 error ("(near initialization for %qs)", ofwhat);
4524 }
4525
4526 /* Issue a pedantic warning for a bad initializer component.
4527 MSGID identifies the message.
4528 The component name is taken from the spelling stack. */
4529
4530 void
pedwarn_init(const char * msgid)4531 pedwarn_init (const char *msgid)
4532 {
4533 char *ofwhat;
4534
4535 pedwarn ("%s", _(msgid));
4536 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4537 if (*ofwhat)
4538 pedwarn ("(near initialization for %qs)", ofwhat);
4539 }
4540
4541 /* Issue a warning for a bad initializer component.
4542 MSGID identifies the message.
4543 The component name is taken from the spelling stack. */
4544
4545 static void
warning_init(const char * msgid)4546 warning_init (const char *msgid)
4547 {
4548 char *ofwhat;
4549
4550 warning (0, "%s", _(msgid));
4551 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4552 if (*ofwhat)
4553 warning (0, "(near initialization for %qs)", ofwhat);
4554 }
4555
4556 /* If TYPE is an array type and EXPR is a parenthesized string
4557 constant, warn if pedantic that EXPR is being used to initialize an
4558 object of type TYPE. */
4559
4560 void
maybe_warn_string_init(tree type,struct c_expr expr)4561 maybe_warn_string_init (tree type, struct c_expr expr)
4562 {
4563 if (pedantic
4564 && TREE_CODE (type) == ARRAY_TYPE
4565 && TREE_CODE (expr.value) == STRING_CST
4566 && expr.original_code != STRING_CST)
4567 pedwarn_init ("array initialized from parenthesized string constant");
4568 }
4569
4570 /* Digest the parser output INIT as an initializer for type TYPE.
4571 Return a C expression of type TYPE to represent the initial value.
4572
4573 If INIT is a string constant, STRICT_STRING is true if it is
4574 unparenthesized or we should not warn here for it being parenthesized.
4575 For other types of INIT, STRICT_STRING is not used.
4576
4577 REQUIRE_CONSTANT requests an error if non-constant initializers or
4578 elements are seen. */
4579
4580 static tree
digest_init(tree type,tree init,bool strict_string,int require_constant)4581 digest_init (tree type, tree init, bool strict_string, int require_constant)
4582 {
4583 enum tree_code code = TREE_CODE (type);
4584 tree inside_init = init;
4585
4586 if (type == error_mark_node
4587 || !init
4588 || init == error_mark_node
4589 || TREE_TYPE (init) == error_mark_node)
4590 return error_mark_node;
4591
4592 STRIP_TYPE_NOPS (inside_init);
4593
4594 inside_init = fold (inside_init);
4595
4596 /* Initialization of an array of chars from a string constant
4597 optionally enclosed in braces. */
4598
4599 if (code == ARRAY_TYPE && inside_init
4600 && TREE_CODE (inside_init) == STRING_CST)
4601 {
4602 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4603 /* Note that an array could be both an array of character type
4604 and an array of wchar_t if wchar_t is signed char or unsigned
4605 char. */
4606 bool char_array = (typ1 == char_type_node
4607 || typ1 == signed_char_type_node
4608 || typ1 == unsigned_char_type_node);
4609 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4610 if (char_array || wchar_array)
4611 {
4612 struct c_expr expr;
4613 bool char_string;
4614 expr.value = inside_init;
4615 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4616 maybe_warn_string_init (type, expr);
4617
4618 char_string
4619 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4620 == char_type_node);
4621
4622 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4623 TYPE_MAIN_VARIANT (type)))
4624 return inside_init;
4625
4626 if (!wchar_array && !char_string)
4627 {
4628 error_init ("char-array initialized from wide string");
4629 return error_mark_node;
4630 }
4631 if (char_string && !char_array)
4632 {
4633 error_init ("wchar_t-array initialized from non-wide string");
4634 return error_mark_node;
4635 }
4636
4637 TREE_TYPE (inside_init) = type;
4638 if (TYPE_DOMAIN (type) != 0
4639 && TYPE_SIZE (type) != 0
4640 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4641 /* Subtract 1 (or sizeof (wchar_t))
4642 because it's ok to ignore the terminating null char
4643 that is counted in the length of the constant. */
4644 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4645 TREE_STRING_LENGTH (inside_init)
4646 - ((TYPE_PRECISION (typ1)
4647 != TYPE_PRECISION (char_type_node))
4648 ? (TYPE_PRECISION (wchar_type_node)
4649 / BITS_PER_UNIT)
4650 : 1)))
4651 pedwarn_init ("initializer-string for array of chars is too long");
4652
4653 return inside_init;
4654 }
4655 else if (INTEGRAL_TYPE_P (typ1))
4656 {
4657 error_init ("array of inappropriate type initialized "
4658 "from string constant");
4659 return error_mark_node;
4660 }
4661 }
4662
4663 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4664 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4665 below and handle as a constructor. */
4666 if (code == VECTOR_TYPE
4667 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4668 && vector_types_convertible_p (TREE_TYPE (inside_init), type)
4669 && TREE_CONSTANT (inside_init))
4670 {
4671 if (TREE_CODE (inside_init) == VECTOR_CST
4672 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4673 TYPE_MAIN_VARIANT (type)))
4674 return inside_init;
4675
4676 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4677 {
4678 unsigned HOST_WIDE_INT ix;
4679 tree value;
4680 bool constant_p = true;
4681
4682 /* Iterate through elements and check if all constructor
4683 elements are *_CSTs. */
4684 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4685 if (!CONSTANT_CLASS_P (value))
4686 {
4687 constant_p = false;
4688 break;
4689 }
4690
4691 if (constant_p)
4692 return build_vector_from_ctor (type,
4693 CONSTRUCTOR_ELTS (inside_init));
4694 }
4695 }
4696
4697 /* Any type can be initialized
4698 from an expression of the same type, optionally with braces. */
4699
4700 if (inside_init && TREE_TYPE (inside_init) != 0
4701 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4702 TYPE_MAIN_VARIANT (type))
4703 || (code == ARRAY_TYPE
4704 && comptypes (TREE_TYPE (inside_init), type))
4705 || (code == VECTOR_TYPE
4706 && comptypes (TREE_TYPE (inside_init), type))
4707 || (code == POINTER_TYPE
4708 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4709 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4710 TREE_TYPE (type)))))
4711 {
4712 if (code == POINTER_TYPE)
4713 {
4714 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4715 {
4716 if (TREE_CODE (inside_init) == STRING_CST
4717 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4718 inside_init = array_to_pointer_conversion (inside_init);
4719 else
4720 {
4721 error_init ("invalid use of non-lvalue array");
4722 return error_mark_node;
4723 }
4724 }
4725 }
4726
4727 if (code == VECTOR_TYPE)
4728 /* Although the types are compatible, we may require a
4729 conversion. */
4730 inside_init = convert (type, inside_init);
4731
4732 if (require_constant
4733 && (code == VECTOR_TYPE || !flag_isoc99)
4734 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4735 {
4736 /* As an extension, allow initializing objects with static storage
4737 duration with compound literals (which are then treated just as
4738 the brace enclosed list they contain). Also allow this for
4739 vectors, as we can only assign them with compound literals. */
4740 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4741 inside_init = DECL_INITIAL (decl);
4742 }
4743
4744 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4745 && TREE_CODE (inside_init) != CONSTRUCTOR)
4746 {
4747 error_init ("array initialized from non-constant array expression");
4748 return error_mark_node;
4749 }
4750
4751 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4752 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4753
4754 /* Compound expressions can only occur here if -pedantic or
4755 -pedantic-errors is specified. In the later case, we always want
4756 an error. In the former case, we simply want a warning. */
4757 if (require_constant && pedantic
4758 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4759 {
4760 inside_init
4761 = valid_compound_expr_initializer (inside_init,
4762 TREE_TYPE (inside_init));
4763 if (inside_init == error_mark_node)
4764 error_init ("initializer element is not constant");
4765 else
4766 pedwarn_init ("initializer element is not constant");
4767 if (flag_pedantic_errors)
4768 inside_init = error_mark_node;
4769 }
4770 else if (require_constant
4771 && !initializer_constant_valid_p (inside_init,
4772 TREE_TYPE (inside_init)))
4773 {
4774 error_init ("initializer element is not constant");
4775 inside_init = error_mark_node;
4776 }
4777
4778 /* Added to enable additional -Wmissing-format-attribute warnings. */
4779 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4780 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4781 NULL_TREE, 0);
4782 return inside_init;
4783 }
4784
4785 /* Handle scalar types, including conversions. */
4786
4787 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4788 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE
4789 || code == VECTOR_TYPE)
4790 {
4791 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4792 && (TREE_CODE (init) == STRING_CST
4793 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4794 init = array_to_pointer_conversion (init);
4795 inside_init
4796 = convert_for_assignment (type, init, ic_init,
4797 NULL_TREE, NULL_TREE, 0);
4798
4799 /* Check to see if we have already given an error message. */
4800 if (inside_init == error_mark_node)
4801 ;
4802 else if (require_constant && !TREE_CONSTANT (inside_init))
4803 {
4804 error_init ("initializer element is not constant");
4805 inside_init = error_mark_node;
4806 }
4807 else if (require_constant
4808 && !initializer_constant_valid_p (inside_init,
4809 TREE_TYPE (inside_init)))
4810 {
4811 error_init ("initializer element is not computable at load time");
4812 inside_init = error_mark_node;
4813 }
4814
4815 return inside_init;
4816 }
4817
4818 /* Come here only for records and arrays. */
4819
4820 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4821 {
4822 error_init ("variable-sized object may not be initialized");
4823 return error_mark_node;
4824 }
4825
4826 error_init ("invalid initializer");
4827 return error_mark_node;
4828 }
4829
4830 /* Handle initializers that use braces. */
4831
4832 /* Type of object we are accumulating a constructor for.
4833 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4834 static tree constructor_type;
4835
4836 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4837 left to fill. */
4838 static tree constructor_fields;
4839
4840 /* For an ARRAY_TYPE, this is the specified index
4841 at which to store the next element we get. */
4842 static tree constructor_index;
4843
4844 /* For an ARRAY_TYPE, this is the maximum index. */
4845 static tree constructor_max_index;
4846
4847 /* For a RECORD_TYPE, this is the first field not yet written out. */
4848 static tree constructor_unfilled_fields;
4849
4850 /* For an ARRAY_TYPE, this is the index of the first element
4851 not yet written out. */
4852 static tree constructor_unfilled_index;
4853
4854 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4855 This is so we can generate gaps between fields, when appropriate. */
4856 static tree constructor_bit_index;
4857
4858 /* If we are saving up the elements rather than allocating them,
4859 this is the list of elements so far (in reverse order,
4860 most recent first). */
4861 static VEC(constructor_elt,gc) *constructor_elements;
4862
4863 /* 1 if constructor should be incrementally stored into a constructor chain,
4864 0 if all the elements should be kept in AVL tree. */
4865 static int constructor_incremental;
4866
4867 /* 1 if so far this constructor's elements are all compile-time constants. */
4868 static int constructor_constant;
4869
4870 /* 1 if so far this constructor's elements are all valid address constants. */
4871 static int constructor_simple;
4872
4873 /* 1 if this constructor is erroneous so far. */
4874 static int constructor_erroneous;
4875
4876 /* 1 if this constructor is a zero init. */
4877 static int constructor_zeroinit;
4878
4879 /* Structure for managing pending initializer elements, organized as an
4880 AVL tree. */
4881
4882 struct init_node
4883 {
4884 struct init_node *left, *right;
4885 struct init_node *parent;
4886 int balance;
4887 tree purpose;
4888 tree value;
4889 };
4890
4891 /* Tree of pending elements at this constructor level.
4892 These are elements encountered out of order
4893 which belong at places we haven't reached yet in actually
4894 writing the output.
4895 Will never hold tree nodes across GC runs. */
4896 static struct init_node *constructor_pending_elts;
4897
4898 /* The SPELLING_DEPTH of this constructor. */
4899 static int constructor_depth;
4900
4901 /* DECL node for which an initializer is being read.
4902 0 means we are reading a constructor expression
4903 such as (struct foo) {...}. */
4904 static tree constructor_decl;
4905
4906 /* Nonzero if this is an initializer for a top-level decl. */
4907 static int constructor_top_level;
4908
4909 /* Nonzero if there were any member designators in this initializer. */
4910 static int constructor_designated;
4911
4912 /* Nesting depth of designator list. */
4913 static int designator_depth;
4914
4915 /* Nonzero if there were diagnosed errors in this designator list. */
4916 static int designator_erroneous;
4917
4918
4919 /* This stack has a level for each implicit or explicit level of
4920 structuring in the initializer, including the outermost one. It
4921 saves the values of most of the variables above. */
4922
4923 struct constructor_range_stack;
4924
4925 struct constructor_stack
4926 {
4927 struct constructor_stack *next;
4928 tree type;
4929 tree fields;
4930 tree index;
4931 tree max_index;
4932 tree unfilled_index;
4933 tree unfilled_fields;
4934 tree bit_index;
4935 VEC(constructor_elt,gc) *elements;
4936 struct init_node *pending_elts;
4937 int offset;
4938 int depth;
4939 /* If value nonzero, this value should replace the entire
4940 constructor at this level. */
4941 struct c_expr replacement_value;
4942 struct constructor_range_stack *range_stack;
4943 char constant;
4944 char simple;
4945 char implicit;
4946 char erroneous;
4947 char outer;
4948 char incremental;
4949 char designated;
4950 };
4951
4952 static struct constructor_stack *constructor_stack;
4953
4954 /* This stack represents designators from some range designator up to
4955 the last designator in the list. */
4956
4957 struct constructor_range_stack
4958 {
4959 struct constructor_range_stack *next, *prev;
4960 struct constructor_stack *stack;
4961 tree range_start;
4962 tree index;
4963 tree range_end;
4964 tree fields;
4965 };
4966
4967 static struct constructor_range_stack *constructor_range_stack;
4968
4969 /* This stack records separate initializers that are nested.
4970 Nested initializers can't happen in ANSI C, but GNU C allows them
4971 in cases like { ... (struct foo) { ... } ... }. */
4972
4973 struct initializer_stack
4974 {
4975 struct initializer_stack *next;
4976 tree decl;
4977 struct constructor_stack *constructor_stack;
4978 struct constructor_range_stack *constructor_range_stack;
4979 VEC(constructor_elt,gc) *elements;
4980 struct spelling *spelling;
4981 struct spelling *spelling_base;
4982 int spelling_size;
4983 char top_level;
4984 char require_constant_value;
4985 char require_constant_elements;
4986 };
4987
4988 static struct initializer_stack *initializer_stack;
4989
4990 /* Prepare to parse and output the initializer for variable DECL. */
4991
4992 void
start_init(tree decl,tree asmspec_tree ATTRIBUTE_UNUSED,int top_level)4993 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
4994 {
4995 const char *locus;
4996 struct initializer_stack *p = XNEW (struct initializer_stack);
4997
4998 p->decl = constructor_decl;
4999 p->require_constant_value = require_constant_value;
5000 p->require_constant_elements = require_constant_elements;
5001 p->constructor_stack = constructor_stack;
5002 p->constructor_range_stack = constructor_range_stack;
5003 p->elements = constructor_elements;
5004 p->spelling = spelling;
5005 p->spelling_base = spelling_base;
5006 p->spelling_size = spelling_size;
5007 p->top_level = constructor_top_level;
5008 p->next = initializer_stack;
5009 initializer_stack = p;
5010
5011 constructor_decl = decl;
5012 constructor_designated = 0;
5013 constructor_top_level = top_level;
5014
5015 if (decl != 0 && decl != error_mark_node)
5016 {
5017 require_constant_value = TREE_STATIC (decl);
5018 require_constant_elements
5019 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5020 /* For a scalar, you can always use any value to initialize,
5021 even within braces. */
5022 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5023 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5024 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5025 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5026 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5027 }
5028 else
5029 {
5030 require_constant_value = 0;
5031 require_constant_elements = 0;
5032 locus = "(anonymous)";
5033 }
5034
5035 constructor_stack = 0;
5036 constructor_range_stack = 0;
5037
5038 constructor_zeroinit = 0;
5039 missing_braces_mentioned = 0;
5040
5041 spelling_base = 0;
5042 spelling_size = 0;
5043 RESTORE_SPELLING_DEPTH (0);
5044
5045 if (locus)
5046 push_string (locus);
5047 }
5048
5049 void
finish_init(void)5050 finish_init (void)
5051 {
5052 struct initializer_stack *p = initializer_stack;
5053
5054 /* Free the whole constructor stack of this initializer. */
5055 while (constructor_stack)
5056 {
5057 struct constructor_stack *q = constructor_stack;
5058 constructor_stack = q->next;
5059 free (q);
5060 }
5061
5062 gcc_assert (!constructor_range_stack);
5063
5064 /* Pop back to the data of the outer initializer (if any). */
5065 free (spelling_base);
5066
5067 constructor_decl = p->decl;
5068 require_constant_value = p->require_constant_value;
5069 require_constant_elements = p->require_constant_elements;
5070 constructor_stack = p->constructor_stack;
5071 constructor_range_stack = p->constructor_range_stack;
5072 constructor_elements = p->elements;
5073 spelling = p->spelling;
5074 spelling_base = p->spelling_base;
5075 spelling_size = p->spelling_size;
5076 constructor_top_level = p->top_level;
5077 initializer_stack = p->next;
5078 free (p);
5079 }
5080
5081 /* Call here when we see the initializer is surrounded by braces.
5082 This is instead of a call to push_init_level;
5083 it is matched by a call to pop_init_level.
5084
5085 TYPE is the type to initialize, for a constructor expression.
5086 For an initializer for a decl, TYPE is zero. */
5087
5088 void
really_start_incremental_init(tree type)5089 really_start_incremental_init (tree type)
5090 {
5091 struct constructor_stack *p = XNEW (struct constructor_stack);
5092
5093 if (type == 0)
5094 type = TREE_TYPE (constructor_decl);
5095
5096 if (targetm.vector_opaque_p (type))
5097 error ("opaque vector types cannot be initialized");
5098
5099 p->type = constructor_type;
5100 p->fields = constructor_fields;
5101 p->index = constructor_index;
5102 p->max_index = constructor_max_index;
5103 p->unfilled_index = constructor_unfilled_index;
5104 p->unfilled_fields = constructor_unfilled_fields;
5105 p->bit_index = constructor_bit_index;
5106 p->elements = constructor_elements;
5107 p->constant = constructor_constant;
5108 p->simple = constructor_simple;
5109 p->erroneous = constructor_erroneous;
5110 p->pending_elts = constructor_pending_elts;
5111 p->depth = constructor_depth;
5112 p->replacement_value.value = 0;
5113 p->replacement_value.original_code = ERROR_MARK;
5114 p->implicit = 0;
5115 p->range_stack = 0;
5116 p->outer = 0;
5117 p->incremental = constructor_incremental;
5118 p->designated = constructor_designated;
5119 p->next = 0;
5120 constructor_stack = p;
5121
5122 constructor_constant = 1;
5123 constructor_simple = 1;
5124 constructor_depth = SPELLING_DEPTH ();
5125 constructor_elements = 0;
5126 constructor_pending_elts = 0;
5127 constructor_type = type;
5128 constructor_incremental = 1;
5129 constructor_designated = 0;
5130 designator_depth = 0;
5131 designator_erroneous = 0;
5132
5133 if (TREE_CODE (constructor_type) == RECORD_TYPE
5134 || TREE_CODE (constructor_type) == UNION_TYPE)
5135 {
5136 constructor_fields = TYPE_FIELDS (constructor_type);
5137 /* Skip any nameless bit fields at the beginning. */
5138 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5139 && DECL_NAME (constructor_fields) == 0)
5140 constructor_fields = TREE_CHAIN (constructor_fields);
5141
5142 constructor_unfilled_fields = constructor_fields;
5143 constructor_bit_index = bitsize_zero_node;
5144 }
5145 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5146 {
5147 if (TYPE_DOMAIN (constructor_type))
5148 {
5149 constructor_max_index
5150 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5151
5152 /* Detect non-empty initializations of zero-length arrays. */
5153 if (constructor_max_index == NULL_TREE
5154 && TYPE_SIZE (constructor_type))
5155 constructor_max_index = build_int_cst (NULL_TREE, -1);
5156
5157 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5158 to initialize VLAs will cause a proper error; avoid tree
5159 checking errors as well by setting a safe value. */
5160 if (constructor_max_index
5161 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5162 constructor_max_index = build_int_cst (NULL_TREE, -1);
5163
5164 constructor_index
5165 = convert (bitsizetype,
5166 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5167 }
5168 else
5169 {
5170 constructor_index = bitsize_zero_node;
5171 constructor_max_index = NULL_TREE;
5172 }
5173
5174 constructor_unfilled_index = constructor_index;
5175 }
5176 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5177 {
5178 /* Vectors are like simple fixed-size arrays. */
5179 constructor_max_index =
5180 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5181 constructor_index = bitsize_zero_node;
5182 constructor_unfilled_index = constructor_index;
5183 }
5184 else
5185 {
5186 /* Handle the case of int x = {5}; */
5187 constructor_fields = constructor_type;
5188 constructor_unfilled_fields = constructor_type;
5189 }
5190 }
5191
5192 /* Push down into a subobject, for initialization.
5193 If this is for an explicit set of braces, IMPLICIT is 0.
5194 If it is because the next element belongs at a lower level,
5195 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5196
5197 void
push_init_level(int implicit)5198 push_init_level (int implicit)
5199 {
5200 struct constructor_stack *p;
5201 tree value = NULL_TREE;
5202
5203 /* If we've exhausted any levels that didn't have braces,
5204 pop them now. If implicit == 1, this will have been done in
5205 process_init_element; do not repeat it here because in the case
5206 of excess initializers for an empty aggregate this leads to an
5207 infinite cycle of popping a level and immediately recreating
5208 it. */
5209 if (implicit != 1)
5210 {
5211 while (constructor_stack->implicit)
5212 {
5213 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5214 || TREE_CODE (constructor_type) == UNION_TYPE)
5215 && constructor_fields == 0)
5216 process_init_element (pop_init_level (1));
5217 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5218 && constructor_max_index
5219 && tree_int_cst_lt (constructor_max_index,
5220 constructor_index))
5221 process_init_element (pop_init_level (1));
5222 else
5223 break;
5224 }
5225 }
5226
5227 /* Unless this is an explicit brace, we need to preserve previous
5228 content if any. */
5229 if (implicit)
5230 {
5231 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5232 || TREE_CODE (constructor_type) == UNION_TYPE)
5233 && constructor_fields)
5234 value = find_init_member (constructor_fields);
5235 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5236 value = find_init_member (constructor_index);
5237 }
5238
5239 p = XNEW (struct constructor_stack);
5240 p->type = constructor_type;
5241 p->fields = constructor_fields;
5242 p->index = constructor_index;
5243 p->max_index = constructor_max_index;
5244 p->unfilled_index = constructor_unfilled_index;
5245 p->unfilled_fields = constructor_unfilled_fields;
5246 p->bit_index = constructor_bit_index;
5247 p->elements = constructor_elements;
5248 p->constant = constructor_constant;
5249 p->simple = constructor_simple;
5250 p->erroneous = constructor_erroneous;
5251 p->pending_elts = constructor_pending_elts;
5252 p->depth = constructor_depth;
5253 p->replacement_value.value = 0;
5254 p->replacement_value.original_code = ERROR_MARK;
5255 p->implicit = implicit;
5256 p->outer = 0;
5257 p->incremental = constructor_incremental;
5258 p->designated = constructor_designated;
5259 p->next = constructor_stack;
5260 p->range_stack = 0;
5261 constructor_stack = p;
5262
5263 constructor_constant = 1;
5264 constructor_simple = 1;
5265 constructor_depth = SPELLING_DEPTH ();
5266 constructor_elements = 0;
5267 constructor_incremental = 1;
5268 constructor_designated = 0;
5269 constructor_pending_elts = 0;
5270 if (!implicit)
5271 {
5272 p->range_stack = constructor_range_stack;
5273 constructor_range_stack = 0;
5274 designator_depth = 0;
5275 designator_erroneous = 0;
5276 }
5277
5278 /* Don't die if an entire brace-pair level is superfluous
5279 in the containing level. */
5280 if (constructor_type == 0)
5281 ;
5282 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5283 || TREE_CODE (constructor_type) == UNION_TYPE)
5284 {
5285 /* Don't die if there are extra init elts at the end. */
5286 if (constructor_fields == 0)
5287 constructor_type = 0;
5288 else
5289 {
5290 constructor_type = TREE_TYPE (constructor_fields);
5291 push_member_name (constructor_fields);
5292 constructor_depth++;
5293 }
5294 }
5295 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5296 {
5297 constructor_type = TREE_TYPE (constructor_type);
5298 push_array_bounds (tree_low_cst (constructor_index, 1));
5299 constructor_depth++;
5300 }
5301
5302 if (constructor_type == 0)
5303 {
5304 error_init ("extra brace group at end of initializer");
5305 constructor_fields = 0;
5306 constructor_unfilled_fields = 0;
5307 return;
5308 }
5309
5310 if (value && TREE_CODE (value) == CONSTRUCTOR)
5311 {
5312 constructor_constant = TREE_CONSTANT (value);
5313 constructor_simple = TREE_STATIC (value);
5314 constructor_elements = CONSTRUCTOR_ELTS (value);
5315 if (!VEC_empty (constructor_elt, constructor_elements)
5316 && (TREE_CODE (constructor_type) == RECORD_TYPE
5317 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5318 set_nonincremental_init ();
5319 }
5320
5321 if (TREE_CODE (constructor_type) == RECORD_TYPE
5322 || TREE_CODE (constructor_type) == UNION_TYPE)
5323 {
5324 constructor_fields = TYPE_FIELDS (constructor_type);
5325 /* Skip any nameless bit fields at the beginning. */
5326 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5327 && DECL_NAME (constructor_fields) == 0)
5328 constructor_fields = TREE_CHAIN (constructor_fields);
5329
5330 constructor_unfilled_fields = constructor_fields;
5331 constructor_bit_index = bitsize_zero_node;
5332 }
5333 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5334 {
5335 /* Vectors are like simple fixed-size arrays. */
5336 constructor_max_index =
5337 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5338 constructor_index = convert (bitsizetype, integer_zero_node);
5339 constructor_unfilled_index = constructor_index;
5340 }
5341 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5342 {
5343 if (TYPE_DOMAIN (constructor_type))
5344 {
5345 constructor_max_index
5346 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5347
5348 /* Detect non-empty initializations of zero-length arrays. */
5349 if (constructor_max_index == NULL_TREE
5350 && TYPE_SIZE (constructor_type))
5351 constructor_max_index = build_int_cst (NULL_TREE, -1);
5352
5353 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5354 to initialize VLAs will cause a proper error; avoid tree
5355 checking errors as well by setting a safe value. */
5356 if (constructor_max_index
5357 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5358 constructor_max_index = build_int_cst (NULL_TREE, -1);
5359
5360 constructor_index
5361 = convert (bitsizetype,
5362 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5363 }
5364 else
5365 constructor_index = bitsize_zero_node;
5366
5367 constructor_unfilled_index = constructor_index;
5368 if (value && TREE_CODE (value) == STRING_CST)
5369 {
5370 /* We need to split the char/wchar array into individual
5371 characters, so that we don't have to special case it
5372 everywhere. */
5373 set_nonincremental_init_from_string (value);
5374 }
5375 }
5376 else
5377 {
5378 if (constructor_type != error_mark_node)
5379 warning_init ("braces around scalar initializer");
5380 constructor_fields = constructor_type;
5381 constructor_unfilled_fields = constructor_type;
5382 }
5383 }
5384
5385 /* At the end of an implicit or explicit brace level,
5386 finish up that level of constructor. If a single expression
5387 with redundant braces initialized that level, return the
5388 c_expr structure for that expression. Otherwise, the original_code
5389 element is set to ERROR_MARK.
5390 If we were outputting the elements as they are read, return 0 as the value
5391 from inner levels (process_init_element ignores that),
5392 but return error_mark_node as the value from the outermost level
5393 (that's what we want to put in DECL_INITIAL).
5394 Otherwise, return a CONSTRUCTOR expression as the value. */
5395
5396 struct c_expr
pop_init_level(int implicit)5397 pop_init_level (int implicit)
5398 {
5399 struct constructor_stack *p;
5400 struct c_expr ret;
5401 ret.value = 0;
5402 ret.original_code = ERROR_MARK;
5403
5404 if (implicit == 0)
5405 {
5406 /* When we come to an explicit close brace,
5407 pop any inner levels that didn't have explicit braces. */
5408 while (constructor_stack->implicit)
5409 process_init_element (pop_init_level (1));
5410
5411 gcc_assert (!constructor_range_stack);
5412 }
5413
5414 /* Now output all pending elements. */
5415 constructor_incremental = 1;
5416 output_pending_init_elements (1);
5417
5418 p = constructor_stack;
5419
5420 /* Error for initializing a flexible array member, or a zero-length
5421 array member in an inappropriate context. */
5422 if (constructor_type && constructor_fields
5423 && TREE_CODE (constructor_type) == ARRAY_TYPE
5424 && TYPE_DOMAIN (constructor_type)
5425 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5426 {
5427 /* Silently discard empty initializations. The parser will
5428 already have pedwarned for empty brackets. */
5429 if (integer_zerop (constructor_unfilled_index))
5430 constructor_type = NULL_TREE;
5431 else
5432 {
5433 gcc_assert (!TYPE_SIZE (constructor_type));
5434
5435 if (constructor_depth > 2)
5436 error_init ("initialization of flexible array member in a nested context");
5437 else if (pedantic)
5438 pedwarn_init ("initialization of a flexible array member");
5439
5440 /* We have already issued an error message for the existence
5441 of a flexible array member not at the end of the structure.
5442 Discard the initializer so that we do not die later. */
5443 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5444 constructor_type = NULL_TREE;
5445 }
5446 }
5447
5448 if (VEC_length (constructor_elt,constructor_elements) == 0)
5449 constructor_zeroinit = 1;
5450 else if (VEC_length (constructor_elt,constructor_elements) == 1 &&
5451 initializer_zerop (VEC_index (constructor_elt,constructor_elements,0)->value))
5452 constructor_zeroinit = 1;
5453 else
5454 constructor_zeroinit = 0;
5455
5456 /* only warn for missing braces unless it is { 0 } */
5457 if (p->implicit == 1 && warn_missing_braces && !missing_braces_mentioned &&
5458 !constructor_zeroinit)
5459 {
5460 missing_braces_mentioned = 1;
5461 warning_init ("missing braces around initializer");
5462 }
5463
5464 /* Warn when some struct elements are implicitly initialized to zero. */
5465 if (warn_missing_field_initializers
5466 && constructor_type
5467 && TREE_CODE (constructor_type) == RECORD_TYPE
5468 && constructor_unfilled_fields)
5469 {
5470 /* Do not warn for flexible array members or zero-length arrays. */
5471 while (constructor_unfilled_fields
5472 && (!DECL_SIZE (constructor_unfilled_fields)
5473 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5474 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5475
5476 /* Do not warn if this level of the initializer uses member
5477 designators; it is likely to be deliberate. */
5478 if (constructor_unfilled_fields && !constructor_designated)
5479 {
5480 push_member_name (constructor_unfilled_fields);
5481 warning_init ("missing initializer");
5482 RESTORE_SPELLING_DEPTH (constructor_depth);
5483 }
5484 }
5485
5486 /* Pad out the end of the structure. */
5487 if (p->replacement_value.value)
5488 /* If this closes a superfluous brace pair,
5489 just pass out the element between them. */
5490 ret = p->replacement_value;
5491 else if (constructor_type == 0)
5492 ;
5493 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5494 && TREE_CODE (constructor_type) != UNION_TYPE
5495 && TREE_CODE (constructor_type) != ARRAY_TYPE
5496 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5497 {
5498 /* A nonincremental scalar initializer--just return
5499 the element, after verifying there is just one. */
5500 if (VEC_empty (constructor_elt,constructor_elements))
5501 {
5502 if (!constructor_erroneous)
5503 error_init ("empty scalar initializer");
5504 ret.value = error_mark_node;
5505 }
5506 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5507 {
5508 error_init ("extra elements in scalar initializer");
5509 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5510 }
5511 else
5512 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5513 }
5514 else
5515 {
5516 if (constructor_erroneous)
5517 ret.value = error_mark_node;
5518 else
5519 {
5520 ret.value = build_constructor (constructor_type,
5521 constructor_elements);
5522 if (constructor_constant)
5523 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1;
5524 if (constructor_constant && constructor_simple)
5525 TREE_STATIC (ret.value) = 1;
5526 }
5527 }
5528
5529 constructor_type = p->type;
5530 constructor_fields = p->fields;
5531 constructor_index = p->index;
5532 constructor_max_index = p->max_index;
5533 constructor_unfilled_index = p->unfilled_index;
5534 constructor_unfilled_fields = p->unfilled_fields;
5535 constructor_bit_index = p->bit_index;
5536 constructor_elements = p->elements;
5537 constructor_constant = p->constant;
5538 constructor_simple = p->simple;
5539 constructor_erroneous = p->erroneous;
5540 constructor_incremental = p->incremental;
5541 constructor_designated = p->designated;
5542 constructor_pending_elts = p->pending_elts;
5543 constructor_depth = p->depth;
5544 if (!p->implicit)
5545 constructor_range_stack = p->range_stack;
5546 RESTORE_SPELLING_DEPTH (constructor_depth);
5547
5548 constructor_stack = p->next;
5549 free (p);
5550
5551 if (ret.value == 0 && constructor_stack == 0)
5552 ret.value = error_mark_node;
5553 return ret;
5554 }
5555
5556 /* Common handling for both array range and field name designators.
5557 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5558
5559 static int
set_designator(int array)5560 set_designator (int array)
5561 {
5562 tree subtype;
5563 enum tree_code subcode;
5564
5565 /* Don't die if an entire brace-pair level is superfluous
5566 in the containing level. */
5567 if (constructor_type == 0)
5568 return 1;
5569
5570 /* If there were errors in this designator list already, bail out
5571 silently. */
5572 if (designator_erroneous)
5573 return 1;
5574
5575 if (!designator_depth)
5576 {
5577 gcc_assert (!constructor_range_stack);
5578
5579 /* Designator list starts at the level of closest explicit
5580 braces. */
5581 while (constructor_stack->implicit)
5582 process_init_element (pop_init_level (1));
5583 constructor_designated = 1;
5584 return 0;
5585 }
5586
5587 switch (TREE_CODE (constructor_type))
5588 {
5589 case RECORD_TYPE:
5590 case UNION_TYPE:
5591 subtype = TREE_TYPE (constructor_fields);
5592 if (subtype != error_mark_node)
5593 subtype = TYPE_MAIN_VARIANT (subtype);
5594 break;
5595 case ARRAY_TYPE:
5596 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5597 break;
5598 default:
5599 gcc_unreachable ();
5600 }
5601
5602 subcode = TREE_CODE (subtype);
5603 if (array && subcode != ARRAY_TYPE)
5604 {
5605 error_init ("array index in non-array initializer");
5606 return 1;
5607 }
5608 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5609 {
5610 error_init ("field name not in record or union initializer");
5611 return 1;
5612 }
5613
5614 constructor_designated = 1;
5615 push_init_level (2);
5616 return 0;
5617 }
5618
5619 /* If there are range designators in designator list, push a new designator
5620 to constructor_range_stack. RANGE_END is end of such stack range or
5621 NULL_TREE if there is no range designator at this level. */
5622
5623 static void
push_range_stack(tree range_end)5624 push_range_stack (tree range_end)
5625 {
5626 struct constructor_range_stack *p;
5627
5628 p = GGC_NEW (struct constructor_range_stack);
5629 p->prev = constructor_range_stack;
5630 p->next = 0;
5631 p->fields = constructor_fields;
5632 p->range_start = constructor_index;
5633 p->index = constructor_index;
5634 p->stack = constructor_stack;
5635 p->range_end = range_end;
5636 if (constructor_range_stack)
5637 constructor_range_stack->next = p;
5638 constructor_range_stack = p;
5639 }
5640
5641 /* Within an array initializer, specify the next index to be initialized.
5642 FIRST is that index. If LAST is nonzero, then initialize a range
5643 of indices, running from FIRST through LAST. */
5644
5645 void
set_init_index(tree first,tree last)5646 set_init_index (tree first, tree last)
5647 {
5648 if (set_designator (1))
5649 return;
5650
5651 designator_erroneous = 1;
5652
5653 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5654 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5655 {
5656 error_init ("array index in initializer not of integer type");
5657 return;
5658 }
5659
5660 if (TREE_CODE (first) != INTEGER_CST)
5661 error_init ("nonconstant array index in initializer");
5662 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5663 error_init ("nonconstant array index in initializer");
5664 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5665 error_init ("array index in non-array initializer");
5666 else if (tree_int_cst_sgn (first) == -1)
5667 error_init ("array index in initializer exceeds array bounds");
5668 else if (constructor_max_index
5669 && tree_int_cst_lt (constructor_max_index, first))
5670 error_init ("array index in initializer exceeds array bounds");
5671 else
5672 {
5673 constructor_index = convert (bitsizetype, first);
5674
5675 if (last)
5676 {
5677 if (tree_int_cst_equal (first, last))
5678 last = 0;
5679 else if (tree_int_cst_lt (last, first))
5680 {
5681 error_init ("empty index range in initializer");
5682 last = 0;
5683 }
5684 else
5685 {
5686 last = convert (bitsizetype, last);
5687 if (constructor_max_index != 0
5688 && tree_int_cst_lt (constructor_max_index, last))
5689 {
5690 error_init ("array index range in initializer exceeds array bounds");
5691 last = 0;
5692 }
5693 }
5694 }
5695
5696 designator_depth++;
5697 designator_erroneous = 0;
5698 if (constructor_range_stack || last)
5699 push_range_stack (last);
5700 }
5701 }
5702
5703 /* Within a struct initializer, specify the next field to be initialized. */
5704
5705 void
set_init_label(tree fieldname)5706 set_init_label (tree fieldname)
5707 {
5708 tree anon = NULL_TREE;
5709 tree tail;
5710
5711 if (set_designator (0))
5712 return;
5713
5714 designator_erroneous = 1;
5715
5716 if (TREE_CODE (constructor_type) != RECORD_TYPE
5717 && TREE_CODE (constructor_type) != UNION_TYPE)
5718 {
5719 error_init ("field name not in record or union initializer");
5720 return;
5721 }
5722
5723 for (tail = TYPE_FIELDS (constructor_type); tail;
5724 tail = TREE_CHAIN (tail))
5725 {
5726 if (DECL_NAME (tail) == NULL_TREE
5727 && (TREE_CODE (TREE_TYPE (tail)) == RECORD_TYPE
5728 || TREE_CODE (TREE_TYPE (tail)) == UNION_TYPE))
5729 {
5730 anon = lookup_field (tail, fieldname);
5731 if (anon)
5732 break;
5733 }
5734
5735 if (DECL_NAME (tail) == fieldname)
5736 break;
5737 }
5738
5739 if (tail == 0)
5740 error ("unknown field %qE specified in initializer", fieldname);
5741
5742 while (tail)
5743 {
5744 constructor_fields = tail;
5745 designator_depth++;
5746 designator_erroneous = 0;
5747 if (constructor_range_stack)
5748 push_range_stack (NULL_TREE);
5749
5750 if (anon)
5751 {
5752 if (set_designator (0))
5753 return;
5754 tail = TREE_VALUE(anon);
5755 anon = TREE_CHAIN(anon);
5756 }
5757 else
5758 tail = NULL_TREE;
5759 }
5760 }
5761
5762 /* Add a new initializer to the tree of pending initializers. PURPOSE
5763 identifies the initializer, either array index or field in a structure.
5764 VALUE is the value of that index or field. */
5765
5766 static void
add_pending_init(tree purpose,tree value)5767 add_pending_init (tree purpose, tree value)
5768 {
5769 struct init_node *p, **q, *r;
5770
5771 q = &constructor_pending_elts;
5772 p = 0;
5773
5774 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5775 {
5776 while (*q != 0)
5777 {
5778 p = *q;
5779 if (tree_int_cst_lt (purpose, p->purpose))
5780 q = &p->left;
5781 else if (tree_int_cst_lt (p->purpose, purpose))
5782 q = &p->right;
5783 else
5784 {
5785 if (TREE_SIDE_EFFECTS (p->value))
5786 warning_init ("initialized field with side-effects overwritten");
5787 else if (warn_override_init)
5788 warning_init ("initialized field overwritten");
5789 p->value = value;
5790 return;
5791 }
5792 }
5793 }
5794 else
5795 {
5796 tree bitpos;
5797
5798 bitpos = bit_position (purpose);
5799 while (*q != NULL)
5800 {
5801 p = *q;
5802 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5803 q = &p->left;
5804 else if (p->purpose != purpose)
5805 q = &p->right;
5806 else
5807 {
5808 if (TREE_SIDE_EFFECTS (p->value))
5809 warning_init ("initialized field with side-effects overwritten");
5810 else if (warn_override_init)
5811 warning_init ("initialized field overwritten");
5812 p->value = value;
5813 return;
5814 }
5815 }
5816 }
5817
5818 r = GGC_NEW (struct init_node);
5819 r->purpose = purpose;
5820 r->value = value;
5821
5822 *q = r;
5823 r->parent = p;
5824 r->left = 0;
5825 r->right = 0;
5826 r->balance = 0;
5827
5828 while (p)
5829 {
5830 struct init_node *s;
5831
5832 if (r == p->left)
5833 {
5834 if (p->balance == 0)
5835 p->balance = -1;
5836 else if (p->balance < 0)
5837 {
5838 if (r->balance < 0)
5839 {
5840 /* L rotation. */
5841 p->left = r->right;
5842 if (p->left)
5843 p->left->parent = p;
5844 r->right = p;
5845
5846 p->balance = 0;
5847 r->balance = 0;
5848
5849 s = p->parent;
5850 p->parent = r;
5851 r->parent = s;
5852 if (s)
5853 {
5854 if (s->left == p)
5855 s->left = r;
5856 else
5857 s->right = r;
5858 }
5859 else
5860 constructor_pending_elts = r;
5861 }
5862 else
5863 {
5864 /* LR rotation. */
5865 struct init_node *t = r->right;
5866
5867 r->right = t->left;
5868 if (r->right)
5869 r->right->parent = r;
5870 t->left = r;
5871
5872 p->left = t->right;
5873 if (p->left)
5874 p->left->parent = p;
5875 t->right = p;
5876
5877 p->balance = t->balance < 0;
5878 r->balance = -(t->balance > 0);
5879 t->balance = 0;
5880
5881 s = p->parent;
5882 p->parent = t;
5883 r->parent = t;
5884 t->parent = s;
5885 if (s)
5886 {
5887 if (s->left == p)
5888 s->left = t;
5889 else
5890 s->right = t;
5891 }
5892 else
5893 constructor_pending_elts = t;
5894 }
5895 break;
5896 }
5897 else
5898 {
5899 /* p->balance == +1; growth of left side balances the node. */
5900 p->balance = 0;
5901 break;
5902 }
5903 }
5904 else /* r == p->right */
5905 {
5906 if (p->balance == 0)
5907 /* Growth propagation from right side. */
5908 p->balance++;
5909 else if (p->balance > 0)
5910 {
5911 if (r->balance > 0)
5912 {
5913 /* R rotation. */
5914 p->right = r->left;
5915 if (p->right)
5916 p->right->parent = p;
5917 r->left = p;
5918
5919 p->balance = 0;
5920 r->balance = 0;
5921
5922 s = p->parent;
5923 p->parent = r;
5924 r->parent = s;
5925 if (s)
5926 {
5927 if (s->left == p)
5928 s->left = r;
5929 else
5930 s->right = r;
5931 }
5932 else
5933 constructor_pending_elts = r;
5934 }
5935 else /* r->balance == -1 */
5936 {
5937 /* RL rotation */
5938 struct init_node *t = r->left;
5939
5940 r->left = t->right;
5941 if (r->left)
5942 r->left->parent = r;
5943 t->right = r;
5944
5945 p->right = t->left;
5946 if (p->right)
5947 p->right->parent = p;
5948 t->left = p;
5949
5950 r->balance = (t->balance < 0);
5951 p->balance = -(t->balance > 0);
5952 t->balance = 0;
5953
5954 s = p->parent;
5955 p->parent = t;
5956 r->parent = t;
5957 t->parent = s;
5958 if (s)
5959 {
5960 if (s->left == p)
5961 s->left = t;
5962 else
5963 s->right = t;
5964 }
5965 else
5966 constructor_pending_elts = t;
5967 }
5968 break;
5969 }
5970 else
5971 {
5972 /* p->balance == -1; growth of right side balances the node. */
5973 p->balance = 0;
5974 break;
5975 }
5976 }
5977
5978 r = p;
5979 p = p->parent;
5980 }
5981 }
5982
5983 /* Build AVL tree from a sorted chain. */
5984
5985 static void
set_nonincremental_init(void)5986 set_nonincremental_init (void)
5987 {
5988 unsigned HOST_WIDE_INT ix;
5989 tree index, value;
5990
5991 if (TREE_CODE (constructor_type) != RECORD_TYPE
5992 && TREE_CODE (constructor_type) != ARRAY_TYPE)
5993 return;
5994
5995 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
5996 add_pending_init (index, value);
5997 constructor_elements = 0;
5998 if (TREE_CODE (constructor_type) == RECORD_TYPE)
5999 {
6000 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
6001 /* Skip any nameless bit fields at the beginning. */
6002 while (constructor_unfilled_fields != 0
6003 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6004 && DECL_NAME (constructor_unfilled_fields) == 0)
6005 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
6006
6007 }
6008 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6009 {
6010 if (TYPE_DOMAIN (constructor_type))
6011 constructor_unfilled_index
6012 = convert (bitsizetype,
6013 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
6014 else
6015 constructor_unfilled_index = bitsize_zero_node;
6016 }
6017 constructor_incremental = 0;
6018 }
6019
6020 /* Build AVL tree from a string constant. */
6021
6022 static void
set_nonincremental_init_from_string(tree str)6023 set_nonincremental_init_from_string (tree str)
6024 {
6025 tree value, purpose, type;
6026 HOST_WIDE_INT val[2];
6027 const char *p, *end;
6028 int byte, wchar_bytes, charwidth, bitpos;
6029
6030 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
6031
6032 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
6033 == TYPE_PRECISION (char_type_node))
6034 wchar_bytes = 1;
6035 else
6036 {
6037 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
6038 == TYPE_PRECISION (wchar_type_node));
6039 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
6040 }
6041 charwidth = TYPE_PRECISION (char_type_node);
6042 type = TREE_TYPE (constructor_type);
6043 p = TREE_STRING_POINTER (str);
6044 end = p + TREE_STRING_LENGTH (str);
6045
6046 for (purpose = bitsize_zero_node;
6047 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6048 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6049 {
6050 if (wchar_bytes == 1)
6051 {
6052 val[1] = (unsigned char) *p++;
6053 val[0] = 0;
6054 }
6055 else
6056 {
6057 val[0] = 0;
6058 val[1] = 0;
6059 for (byte = 0; byte < wchar_bytes; byte++)
6060 {
6061 if (BYTES_BIG_ENDIAN)
6062 bitpos = (wchar_bytes - byte - 1) * charwidth;
6063 else
6064 bitpos = byte * charwidth;
6065 val[bitpos < HOST_BITS_PER_WIDE_INT]
6066 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6067 << (bitpos % HOST_BITS_PER_WIDE_INT);
6068 }
6069 }
6070
6071 if (!TYPE_UNSIGNED (type))
6072 {
6073 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6074 if (bitpos < HOST_BITS_PER_WIDE_INT)
6075 {
6076 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6077 {
6078 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6079 val[0] = -1;
6080 }
6081 }
6082 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6083 {
6084 if (val[1] < 0)
6085 val[0] = -1;
6086 }
6087 else if (val[0] & (((HOST_WIDE_INT) 1)
6088 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6089 val[0] |= ((HOST_WIDE_INT) -1)
6090 << (bitpos - HOST_BITS_PER_WIDE_INT);
6091 }
6092
6093 value = build_int_cst_wide (type, val[1], val[0]);
6094 add_pending_init (purpose, value);
6095 }
6096
6097 constructor_incremental = 0;
6098 }
6099
6100 /* Return value of FIELD in pending initializer or zero if the field was
6101 not initialized yet. */
6102
6103 static tree
find_init_member(tree field)6104 find_init_member (tree field)
6105 {
6106 struct init_node *p;
6107
6108 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6109 {
6110 if (constructor_incremental
6111 && tree_int_cst_lt (field, constructor_unfilled_index))
6112 set_nonincremental_init ();
6113
6114 p = constructor_pending_elts;
6115 while (p)
6116 {
6117 if (tree_int_cst_lt (field, p->purpose))
6118 p = p->left;
6119 else if (tree_int_cst_lt (p->purpose, field))
6120 p = p->right;
6121 else
6122 return p->value;
6123 }
6124 }
6125 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6126 {
6127 tree bitpos = bit_position (field);
6128
6129 if (constructor_incremental
6130 && (!constructor_unfilled_fields
6131 || tree_int_cst_lt (bitpos,
6132 bit_position (constructor_unfilled_fields))))
6133 set_nonincremental_init ();
6134
6135 p = constructor_pending_elts;
6136 while (p)
6137 {
6138 if (field == p->purpose)
6139 return p->value;
6140 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6141 p = p->left;
6142 else
6143 p = p->right;
6144 }
6145 }
6146 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6147 {
6148 if (!VEC_empty (constructor_elt, constructor_elements)
6149 && (VEC_last (constructor_elt, constructor_elements)->index
6150 == field))
6151 return VEC_last (constructor_elt, constructor_elements)->value;
6152 }
6153 return 0;
6154 }
6155
6156 /* "Output" the next constructor element.
6157 At top level, really output it to assembler code now.
6158 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6159 TYPE is the data type that the containing data type wants here.
6160 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6161 If VALUE is a string constant, STRICT_STRING is true if it is
6162 unparenthesized or we should not warn here for it being parenthesized.
6163 For other types of VALUE, STRICT_STRING is not used.
6164
6165 PENDING if non-nil means output pending elements that belong
6166 right after this element. (PENDING is normally 1;
6167 it is 0 while outputting pending elements, to avoid recursion.) */
6168
6169 static void
output_init_element(tree value,bool strict_string,tree type,tree field,int pending)6170 output_init_element (tree value, bool strict_string, tree type, tree field,
6171 int pending)
6172 {
6173 constructor_elt *celt;
6174
6175 if (type == error_mark_node || value == error_mark_node)
6176 {
6177 constructor_erroneous = 1;
6178 return;
6179 }
6180 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6181 && (TREE_CODE (value) == STRING_CST
6182 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6183 && !(TREE_CODE (value) == STRING_CST
6184 && TREE_CODE (type) == ARRAY_TYPE
6185 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6186 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6187 TYPE_MAIN_VARIANT (type)))
6188 value = array_to_pointer_conversion (value);
6189
6190 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6191 && require_constant_value && !flag_isoc99 && pending)
6192 {
6193 /* As an extension, allow initializing objects with static storage
6194 duration with compound literals (which are then treated just as
6195 the brace enclosed list they contain). */
6196 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6197 value = DECL_INITIAL (decl);
6198 }
6199
6200 if (value == error_mark_node)
6201 constructor_erroneous = 1;
6202 else if (!TREE_CONSTANT (value))
6203 constructor_constant = 0;
6204 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6205 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6206 || TREE_CODE (constructor_type) == UNION_TYPE)
6207 && DECL_C_BIT_FIELD (field)
6208 && TREE_CODE (value) != INTEGER_CST))
6209 constructor_simple = 0;
6210
6211 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6212 {
6213 if (require_constant_value)
6214 {
6215 error_init ("initializer element is not constant");
6216 value = error_mark_node;
6217 }
6218 else if (require_constant_elements)
6219 pedwarn ("initializer element is not computable at load time");
6220 }
6221
6222 /* If this field is empty (and not at the end of structure),
6223 don't do anything other than checking the initializer. */
6224 if (field
6225 && (TREE_TYPE (field) == error_mark_node
6226 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6227 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6228 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6229 || TREE_CHAIN (field)))))
6230 return;
6231
6232 value = digest_init (type, value, strict_string, require_constant_value);
6233 if (value == error_mark_node)
6234 {
6235 constructor_erroneous = 1;
6236 return;
6237 }
6238
6239 /* If this element doesn't come next in sequence,
6240 put it on constructor_pending_elts. */
6241 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6242 && (!constructor_incremental
6243 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6244 {
6245 if (constructor_incremental
6246 && tree_int_cst_lt (field, constructor_unfilled_index))
6247 set_nonincremental_init ();
6248
6249 add_pending_init (field, value);
6250 return;
6251 }
6252 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6253 && (!constructor_incremental
6254 || field != constructor_unfilled_fields))
6255 {
6256 /* We do this for records but not for unions. In a union,
6257 no matter which field is specified, it can be initialized
6258 right away since it starts at the beginning of the union. */
6259 if (constructor_incremental)
6260 {
6261 if (!constructor_unfilled_fields)
6262 set_nonincremental_init ();
6263 else
6264 {
6265 tree bitpos, unfillpos;
6266
6267 bitpos = bit_position (field);
6268 unfillpos = bit_position (constructor_unfilled_fields);
6269
6270 if (tree_int_cst_lt (bitpos, unfillpos))
6271 set_nonincremental_init ();
6272 }
6273 }
6274
6275 add_pending_init (field, value);
6276 return;
6277 }
6278 else if (TREE_CODE (constructor_type) == UNION_TYPE
6279 && !VEC_empty (constructor_elt, constructor_elements))
6280 {
6281 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6282 constructor_elements)->value))
6283 warning_init ("initialized field with side-effects overwritten");
6284 else if (warn_override_init)
6285 warning_init ("initialized field overwritten");
6286
6287 /* We can have just one union field set. */
6288 constructor_elements = 0;
6289 }
6290
6291 /* Otherwise, output this element either to
6292 constructor_elements or to the assembler file. */
6293
6294 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6295 celt->index = field;
6296 celt->value = value;
6297
6298 /* Advance the variable that indicates sequential elements output. */
6299 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6300 constructor_unfilled_index
6301 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6302 bitsize_one_node);
6303 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6304 {
6305 constructor_unfilled_fields
6306 = TREE_CHAIN (constructor_unfilled_fields);
6307
6308 /* Skip any nameless bit fields. */
6309 while (constructor_unfilled_fields != 0
6310 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6311 && DECL_NAME (constructor_unfilled_fields) == 0)
6312 constructor_unfilled_fields =
6313 TREE_CHAIN (constructor_unfilled_fields);
6314 }
6315 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6316 constructor_unfilled_fields = 0;
6317
6318 /* Now output any pending elements which have become next. */
6319 if (pending)
6320 output_pending_init_elements (0);
6321 }
6322
6323 /* Output any pending elements which have become next.
6324 As we output elements, constructor_unfilled_{fields,index}
6325 advances, which may cause other elements to become next;
6326 if so, they too are output.
6327
6328 If ALL is 0, we return when there are
6329 no more pending elements to output now.
6330
6331 If ALL is 1, we output space as necessary so that
6332 we can output all the pending elements. */
6333
6334 static void
output_pending_init_elements(int all)6335 output_pending_init_elements (int all)
6336 {
6337 struct init_node *elt = constructor_pending_elts;
6338 tree next;
6339
6340 retry:
6341
6342 /* Look through the whole pending tree.
6343 If we find an element that should be output now,
6344 output it. Otherwise, set NEXT to the element
6345 that comes first among those still pending. */
6346
6347 next = 0;
6348 while (elt)
6349 {
6350 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6351 {
6352 if (tree_int_cst_equal (elt->purpose,
6353 constructor_unfilled_index))
6354 output_init_element (elt->value, true,
6355 TREE_TYPE (constructor_type),
6356 constructor_unfilled_index, 0);
6357 else if (tree_int_cst_lt (constructor_unfilled_index,
6358 elt->purpose))
6359 {
6360 /* Advance to the next smaller node. */
6361 if (elt->left)
6362 elt = elt->left;
6363 else
6364 {
6365 /* We have reached the smallest node bigger than the
6366 current unfilled index. Fill the space first. */
6367 next = elt->purpose;
6368 break;
6369 }
6370 }
6371 else
6372 {
6373 /* Advance to the next bigger node. */
6374 if (elt->right)
6375 elt = elt->right;
6376 else
6377 {
6378 /* We have reached the biggest node in a subtree. Find
6379 the parent of it, which is the next bigger node. */
6380 while (elt->parent && elt->parent->right == elt)
6381 elt = elt->parent;
6382 elt = elt->parent;
6383 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6384 elt->purpose))
6385 {
6386 next = elt->purpose;
6387 break;
6388 }
6389 }
6390 }
6391 }
6392 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6393 || TREE_CODE (constructor_type) == UNION_TYPE)
6394 {
6395 tree ctor_unfilled_bitpos, elt_bitpos;
6396
6397 /* If the current record is complete we are done. */
6398 if (constructor_unfilled_fields == 0)
6399 break;
6400
6401 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6402 elt_bitpos = bit_position (elt->purpose);
6403 /* We can't compare fields here because there might be empty
6404 fields in between. */
6405 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6406 {
6407 constructor_unfilled_fields = elt->purpose;
6408 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6409 elt->purpose, 0);
6410 }
6411 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6412 {
6413 /* Advance to the next smaller node. */
6414 if (elt->left)
6415 elt = elt->left;
6416 else
6417 {
6418 /* We have reached the smallest node bigger than the
6419 current unfilled field. Fill the space first. */
6420 next = elt->purpose;
6421 break;
6422 }
6423 }
6424 else
6425 {
6426 /* Advance to the next bigger node. */
6427 if (elt->right)
6428 elt = elt->right;
6429 else
6430 {
6431 /* We have reached the biggest node in a subtree. Find
6432 the parent of it, which is the next bigger node. */
6433 while (elt->parent && elt->parent->right == elt)
6434 elt = elt->parent;
6435 elt = elt->parent;
6436 if (elt
6437 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6438 bit_position (elt->purpose))))
6439 {
6440 next = elt->purpose;
6441 break;
6442 }
6443 }
6444 }
6445 }
6446 }
6447
6448 /* Ordinarily return, but not if we want to output all
6449 and there are elements left. */
6450 if (!(all && next != 0))
6451 return;
6452
6453 /* If it's not incremental, just skip over the gap, so that after
6454 jumping to retry we will output the next successive element. */
6455 if (TREE_CODE (constructor_type) == RECORD_TYPE
6456 || TREE_CODE (constructor_type) == UNION_TYPE)
6457 constructor_unfilled_fields = next;
6458 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6459 constructor_unfilled_index = next;
6460
6461 /* ELT now points to the node in the pending tree with the next
6462 initializer to output. */
6463 goto retry;
6464 }
6465
6466 /* Add one non-braced element to the current constructor level.
6467 This adjusts the current position within the constructor's type.
6468 This may also start or terminate implicit levels
6469 to handle a partly-braced initializer.
6470
6471 Once this has found the correct level for the new element,
6472 it calls output_init_element. */
6473
6474 void
process_init_element(struct c_expr value)6475 process_init_element (struct c_expr value)
6476 {
6477 tree orig_value = value.value;
6478 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6479 bool strict_string = value.original_code == STRING_CST;
6480
6481 designator_depth = 0;
6482 designator_erroneous = 0;
6483
6484 /* Handle superfluous braces around string cst as in
6485 char x[] = {"foo"}; */
6486 if (string_flag
6487 && constructor_type
6488 && TREE_CODE (constructor_type) == ARRAY_TYPE
6489 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6490 && integer_zerop (constructor_unfilled_index))
6491 {
6492 if (constructor_stack->replacement_value.value)
6493 error_init ("excess elements in char array initializer");
6494 constructor_stack->replacement_value = value;
6495 return;
6496 }
6497
6498 if (constructor_stack->replacement_value.value != 0)
6499 {
6500 error_init ("excess elements in struct initializer");
6501 return;
6502 }
6503
6504 /* Ignore elements of a brace group if it is entirely superfluous
6505 and has already been diagnosed. */
6506 if (constructor_type == 0)
6507 return;
6508
6509 /* If we've exhausted any levels that didn't have braces,
6510 pop them now. */
6511 while (constructor_stack->implicit)
6512 {
6513 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6514 || TREE_CODE (constructor_type) == UNION_TYPE)
6515 && constructor_fields == 0)
6516 process_init_element (pop_init_level (1));
6517 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6518 && (constructor_max_index == 0
6519 || tree_int_cst_lt (constructor_max_index,
6520 constructor_index)))
6521 process_init_element (pop_init_level (1));
6522 else
6523 break;
6524 }
6525
6526 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6527 if (constructor_range_stack)
6528 {
6529 /* If value is a compound literal and we'll be just using its
6530 content, don't put it into a SAVE_EXPR. */
6531 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6532 || !require_constant_value
6533 || flag_isoc99)
6534 value.value = save_expr (value.value);
6535 }
6536
6537 while (1)
6538 {
6539 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6540 {
6541 tree fieldtype;
6542 enum tree_code fieldcode;
6543
6544 if (constructor_fields == 0)
6545 {
6546 pedwarn_init ("excess elements in struct initializer");
6547 break;
6548 }
6549
6550 fieldtype = TREE_TYPE (constructor_fields);
6551 if (fieldtype != error_mark_node)
6552 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6553 fieldcode = TREE_CODE (fieldtype);
6554
6555 /* Error for non-static initialization of a flexible array member. */
6556 if (fieldcode == ARRAY_TYPE
6557 && !require_constant_value
6558 && TYPE_SIZE (fieldtype) == NULL_TREE
6559 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6560 {
6561 error_init ("non-static initialization of a flexible array member");
6562 break;
6563 }
6564
6565 /* Accept a string constant to initialize a subarray. */
6566 if (value.value != 0
6567 && fieldcode == ARRAY_TYPE
6568 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6569 && string_flag)
6570 value.value = orig_value;
6571 /* Otherwise, if we have come to a subaggregate,
6572 and we don't have an element of its type, push into it. */
6573 else if (value.value != 0
6574 && value.value != error_mark_node
6575 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6576 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6577 || fieldcode == UNION_TYPE))
6578 {
6579 push_init_level (1);
6580 continue;
6581 }
6582
6583 if (value.value)
6584 {
6585 push_member_name (constructor_fields);
6586 output_init_element (value.value, strict_string,
6587 fieldtype, constructor_fields, 1);
6588 RESTORE_SPELLING_DEPTH (constructor_depth);
6589 }
6590 else
6591 /* Do the bookkeeping for an element that was
6592 directly output as a constructor. */
6593 {
6594 /* For a record, keep track of end position of last field. */
6595 if (DECL_SIZE (constructor_fields))
6596 constructor_bit_index
6597 = size_binop (PLUS_EXPR,
6598 bit_position (constructor_fields),
6599 DECL_SIZE (constructor_fields));
6600
6601 /* If the current field was the first one not yet written out,
6602 it isn't now, so update. */
6603 if (constructor_unfilled_fields == constructor_fields)
6604 {
6605 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6606 /* Skip any nameless bit fields. */
6607 while (constructor_unfilled_fields != 0
6608 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6609 && DECL_NAME (constructor_unfilled_fields) == 0)
6610 constructor_unfilled_fields =
6611 TREE_CHAIN (constructor_unfilled_fields);
6612 }
6613 }
6614
6615 constructor_fields = TREE_CHAIN (constructor_fields);
6616 /* Skip any nameless bit fields at the beginning. */
6617 while (constructor_fields != 0
6618 && DECL_C_BIT_FIELD (constructor_fields)
6619 && DECL_NAME (constructor_fields) == 0)
6620 constructor_fields = TREE_CHAIN (constructor_fields);
6621 }
6622 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6623 {
6624 tree fieldtype;
6625 enum tree_code fieldcode;
6626
6627 if (constructor_fields == 0)
6628 {
6629 pedwarn_init ("excess elements in union initializer");
6630 break;
6631 }
6632
6633 fieldtype = TREE_TYPE (constructor_fields);
6634 if (fieldtype != error_mark_node)
6635 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6636 fieldcode = TREE_CODE (fieldtype);
6637
6638 /* Warn that traditional C rejects initialization of unions.
6639 We skip the warning if the value is zero. This is done
6640 under the assumption that the zero initializer in user
6641 code appears conditioned on e.g. __STDC__ to avoid
6642 "missing initializer" warnings and relies on default
6643 initialization to zero in the traditional C case.
6644 We also skip the warning if the initializer is designated,
6645 again on the assumption that this must be conditional on
6646 __STDC__ anyway (and we've already complained about the
6647 member-designator already). */
6648 if (!in_system_header && !constructor_designated
6649 && !(value.value && (integer_zerop (value.value)
6650 || real_zerop (value.value))))
6651 warning (OPT_Wtraditional, "traditional C rejects initialization "
6652 "of unions");
6653
6654 /* Accept a string constant to initialize a subarray. */
6655 if (value.value != 0
6656 && fieldcode == ARRAY_TYPE
6657 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6658 && string_flag)
6659 value.value = orig_value;
6660 /* Otherwise, if we have come to a subaggregate,
6661 and we don't have an element of its type, push into it. */
6662 else if (value.value != 0
6663 && value.value != error_mark_node
6664 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6665 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6666 || fieldcode == UNION_TYPE))
6667 {
6668 push_init_level (1);
6669 continue;
6670 }
6671
6672 if (value.value)
6673 {
6674 push_member_name (constructor_fields);
6675 output_init_element (value.value, strict_string,
6676 fieldtype, constructor_fields, 1);
6677 RESTORE_SPELLING_DEPTH (constructor_depth);
6678 }
6679 else
6680 /* Do the bookkeeping for an element that was
6681 directly output as a constructor. */
6682 {
6683 constructor_bit_index = DECL_SIZE (constructor_fields);
6684 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6685 }
6686
6687 constructor_fields = 0;
6688 }
6689 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6690 {
6691 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6692 enum tree_code eltcode = TREE_CODE (elttype);
6693
6694 /* Accept a string constant to initialize a subarray. */
6695 if (value.value != 0
6696 && eltcode == ARRAY_TYPE
6697 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6698 && string_flag)
6699 value.value = orig_value;
6700 /* Otherwise, if we have come to a subaggregate,
6701 and we don't have an element of its type, push into it. */
6702 else if (value.value != 0
6703 && value.value != error_mark_node
6704 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6705 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6706 || eltcode == UNION_TYPE))
6707 {
6708 push_init_level (1);
6709 continue;
6710 }
6711
6712 if (constructor_max_index != 0
6713 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6714 || integer_all_onesp (constructor_max_index)))
6715 {
6716 pedwarn_init ("excess elements in array initializer");
6717 break;
6718 }
6719
6720 /* Now output the actual element. */
6721 if (value.value)
6722 {
6723 push_array_bounds (tree_low_cst (constructor_index, 1));
6724 output_init_element (value.value, strict_string,
6725 elttype, constructor_index, 1);
6726 RESTORE_SPELLING_DEPTH (constructor_depth);
6727 }
6728
6729 constructor_index
6730 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6731
6732 if (!value.value)
6733 /* If we are doing the bookkeeping for an element that was
6734 directly output as a constructor, we must update
6735 constructor_unfilled_index. */
6736 constructor_unfilled_index = constructor_index;
6737 }
6738 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6739 {
6740 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6741
6742 /* Do a basic check of initializer size. Note that vectors
6743 always have a fixed size derived from their type. */
6744 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6745 {
6746 pedwarn_init ("excess elements in vector initializer");
6747 break;
6748 }
6749
6750 /* Now output the actual element. */
6751 if (value.value)
6752 output_init_element (value.value, strict_string,
6753 elttype, constructor_index, 1);
6754
6755 constructor_index
6756 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6757
6758 if (!value.value)
6759 /* If we are doing the bookkeeping for an element that was
6760 directly output as a constructor, we must update
6761 constructor_unfilled_index. */
6762 constructor_unfilled_index = constructor_index;
6763 }
6764
6765 /* Handle the sole element allowed in a braced initializer
6766 for a scalar variable. */
6767 else if (constructor_type != error_mark_node
6768 && constructor_fields == 0)
6769 {
6770 pedwarn_init ("excess elements in scalar initializer");
6771 break;
6772 }
6773 else
6774 {
6775 if (value.value)
6776 output_init_element (value.value, strict_string,
6777 constructor_type, NULL_TREE, 1);
6778 constructor_fields = 0;
6779 }
6780
6781 /* Handle range initializers either at this level or anywhere higher
6782 in the designator stack. */
6783 if (constructor_range_stack)
6784 {
6785 struct constructor_range_stack *p, *range_stack;
6786 int finish = 0;
6787
6788 range_stack = constructor_range_stack;
6789 constructor_range_stack = 0;
6790 while (constructor_stack != range_stack->stack)
6791 {
6792 gcc_assert (constructor_stack->implicit);
6793 process_init_element (pop_init_level (1));
6794 }
6795 for (p = range_stack;
6796 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6797 p = p->prev)
6798 {
6799 gcc_assert (constructor_stack->implicit);
6800 process_init_element (pop_init_level (1));
6801 }
6802
6803 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6804 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6805 finish = 1;
6806
6807 while (1)
6808 {
6809 constructor_index = p->index;
6810 constructor_fields = p->fields;
6811 if (finish && p->range_end && p->index == p->range_start)
6812 {
6813 finish = 0;
6814 p->prev = 0;
6815 }
6816 p = p->next;
6817 if (!p)
6818 break;
6819 push_init_level (2);
6820 p->stack = constructor_stack;
6821 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6822 p->index = p->range_start;
6823 }
6824
6825 if (!finish)
6826 constructor_range_stack = range_stack;
6827 continue;
6828 }
6829
6830 break;
6831 }
6832
6833 constructor_range_stack = 0;
6834 }
6835
6836 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6837 (guaranteed to be 'volatile' or null) and ARGS (represented using
6838 an ASM_EXPR node). */
6839 tree
build_asm_stmt(tree cv_qualifier,tree args)6840 build_asm_stmt (tree cv_qualifier, tree args)
6841 {
6842 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6843 ASM_VOLATILE_P (args) = 1;
6844 return add_stmt (args);
6845 }
6846
6847 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6848 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6849 SIMPLE indicates whether there was anything at all after the
6850 string in the asm expression -- asm("blah") and asm("blah" : )
6851 are subtly different. We use a ASM_EXPR node to represent this. */
6852 tree
build_asm_expr(tree string,tree outputs,tree inputs,tree clobbers,bool simple)6853 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6854 bool simple)
6855 {
6856 tree tail;
6857 tree args;
6858 int i;
6859 const char *constraint;
6860 const char **oconstraints;
6861 bool allows_mem, allows_reg, is_inout;
6862 int ninputs, noutputs;
6863
6864 ninputs = list_length (inputs);
6865 noutputs = list_length (outputs);
6866 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6867
6868 string = resolve_asm_operand_names (string, outputs, inputs);
6869
6870 /* Remove output conversions that change the type but not the mode. */
6871 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6872 {
6873 tree output = TREE_VALUE (tail);
6874
6875 /* ??? Really, this should not be here. Users should be using a
6876 proper lvalue, dammit. But there's a long history of using casts
6877 in the output operands. In cases like longlong.h, this becomes a
6878 primitive form of typechecking -- if the cast can be removed, then
6879 the output operand had a type of the proper width; otherwise we'll
6880 get an error. Gross, but ... */
6881 STRIP_NOPS (output);
6882
6883 if (!lvalue_or_else (output, lv_asm))
6884 output = error_mark_node;
6885
6886 if (output != error_mark_node
6887 && (TREE_READONLY (output)
6888 || TYPE_READONLY (TREE_TYPE (output))
6889 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6890 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6891 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6892 readonly_error (output, lv_asm);
6893
6894 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6895 oconstraints[i] = constraint;
6896
6897 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6898 &allows_mem, &allows_reg, &is_inout))
6899 {
6900 /* If the operand is going to end up in memory,
6901 mark it addressable. */
6902 if (!allows_reg && !c_mark_addressable (output))
6903 output = error_mark_node;
6904 }
6905 else
6906 output = error_mark_node;
6907
6908 TREE_VALUE (tail) = output;
6909 }
6910
6911 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
6912 {
6913 tree input;
6914
6915 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6916 input = TREE_VALUE (tail);
6917
6918 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
6919 oconstraints, &allows_mem, &allows_reg))
6920 {
6921 /* If the operand is going to end up in memory,
6922 mark it addressable. */
6923 if (!allows_reg && allows_mem)
6924 {
6925 /* Strip the nops as we allow this case. FIXME, this really
6926 should be rejected or made deprecated. */
6927 STRIP_NOPS (input);
6928 if (!c_mark_addressable (input))
6929 input = error_mark_node;
6930 }
6931 }
6932 else
6933 input = error_mark_node;
6934
6935 TREE_VALUE (tail) = input;
6936 }
6937
6938 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
6939
6940 /* asm statements without outputs, including simple ones, are treated
6941 as volatile. */
6942 ASM_INPUT_P (args) = simple;
6943 ASM_VOLATILE_P (args) = (noutputs == 0);
6944
6945 return args;
6946 }
6947
6948 /* Generate a goto statement to LABEL. */
6949
6950 tree
c_finish_goto_label(tree label)6951 c_finish_goto_label (tree label)
6952 {
6953 tree decl = lookup_label (label);
6954 if (!decl)
6955 return NULL_TREE;
6956
6957 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
6958 {
6959 error ("jump into statement expression");
6960 return NULL_TREE;
6961 }
6962
6963 if (C_DECL_UNJUMPABLE_VM (decl))
6964 {
6965 error ("jump into scope of identifier with variably modified type");
6966 return NULL_TREE;
6967 }
6968
6969 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
6970 {
6971 /* No jump from outside this statement expression context, so
6972 record that there is a jump from within this context. */
6973 struct c_label_list *nlist;
6974 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6975 nlist->next = label_context_stack_se->labels_used;
6976 nlist->label = decl;
6977 label_context_stack_se->labels_used = nlist;
6978 }
6979
6980 if (!C_DECL_UNDEFINABLE_VM (decl))
6981 {
6982 /* No jump from outside this context context of identifiers with
6983 variably modified type, so record that there is a jump from
6984 within this context. */
6985 struct c_label_list *nlist;
6986 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6987 nlist->next = label_context_stack_vm->labels_used;
6988 nlist->label = decl;
6989 label_context_stack_vm->labels_used = nlist;
6990 }
6991
6992 TREE_USED (decl) = 1;
6993 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
6994 }
6995
6996 /* Generate a computed goto statement to EXPR. */
6997
6998 tree
c_finish_goto_ptr(tree expr)6999 c_finish_goto_ptr (tree expr)
7000 {
7001 if (pedantic)
7002 pedwarn ("ISO C forbids %<goto *expr;%>");
7003 expr = convert (ptr_type_node, expr);
7004 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
7005 }
7006
7007 /* Generate a C `return' statement. RETVAL is the expression for what
7008 to return, or a null pointer for `return;' with no value. */
7009
7010 tree
c_finish_return(tree retval)7011 c_finish_return (tree retval)
7012 {
7013 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
7014 bool no_warning = false;
7015
7016 if (TREE_THIS_VOLATILE (current_function_decl))
7017 warning (0, "function declared %<noreturn%> has a %<return%> statement");
7018
7019 if (!retval)
7020 {
7021 current_function_returns_null = 1;
7022 if ((warn_return_type || flag_isoc99)
7023 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
7024 {
7025 pedwarn_c99 ("%<return%> with no value, in "
7026 "function returning non-void");
7027 no_warning = true;
7028 }
7029 }
7030 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
7031 {
7032 current_function_returns_null = 1;
7033 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
7034 pedwarn ("%<return%> with a value, in function returning void");
7035 }
7036 else
7037 {
7038 tree t = convert_for_assignment (valtype, retval, ic_return,
7039 NULL_TREE, NULL_TREE, 0);
7040 tree res = DECL_RESULT (current_function_decl);
7041 tree inner;
7042
7043 current_function_returns_value = 1;
7044 if (t == error_mark_node)
7045 return NULL_TREE;
7046
7047 inner = t = convert (TREE_TYPE (res), t);
7048
7049 /* Strip any conversions, additions, and subtractions, and see if
7050 we are returning the address of a local variable. Warn if so. */
7051 while (1)
7052 {
7053 switch (TREE_CODE (inner))
7054 {
7055 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
7056 case PLUS_EXPR:
7057 inner = TREE_OPERAND (inner, 0);
7058 continue;
7059
7060 case MINUS_EXPR:
7061 /* If the second operand of the MINUS_EXPR has a pointer
7062 type (or is converted from it), this may be valid, so
7063 don't give a warning. */
7064 {
7065 tree op1 = TREE_OPERAND (inner, 1);
7066
7067 while (!POINTER_TYPE_P (TREE_TYPE (op1))
7068 && (TREE_CODE (op1) == NOP_EXPR
7069 || TREE_CODE (op1) == NON_LVALUE_EXPR
7070 || TREE_CODE (op1) == CONVERT_EXPR))
7071 op1 = TREE_OPERAND (op1, 0);
7072
7073 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7074 break;
7075
7076 inner = TREE_OPERAND (inner, 0);
7077 continue;
7078 }
7079
7080 case ADDR_EXPR:
7081 inner = TREE_OPERAND (inner, 0);
7082
7083 while (REFERENCE_CLASS_P (inner)
7084 && TREE_CODE (inner) != INDIRECT_REF)
7085 inner = TREE_OPERAND (inner, 0);
7086
7087 if (DECL_P (inner)
7088 && !DECL_EXTERNAL (inner)
7089 && !TREE_STATIC (inner)
7090 && DECL_CONTEXT (inner) == current_function_decl)
7091 warning (0, "function returns address of local variable");
7092 break;
7093
7094 default:
7095 break;
7096 }
7097
7098 break;
7099 }
7100
7101 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7102 }
7103
7104 ret_stmt = build_stmt (RETURN_EXPR, retval);
7105 TREE_NO_WARNING (ret_stmt) |= no_warning;
7106 return add_stmt (ret_stmt);
7107 }
7108
7109 struct c_switch {
7110 /* The SWITCH_EXPR being built. */
7111 tree switch_expr;
7112
7113 /* The original type of the testing expression, i.e. before the
7114 default conversion is applied. */
7115 tree orig_type;
7116
7117 /* A splay-tree mapping the low element of a case range to the high
7118 element, or NULL_TREE if there is no high element. Used to
7119 determine whether or not a new case label duplicates an old case
7120 label. We need a tree, rather than simply a hash table, because
7121 of the GNU case range extension. */
7122 splay_tree cases;
7123
7124 /* Number of nested statement expressions within this switch
7125 statement; if nonzero, case and default labels may not
7126 appear. */
7127 unsigned int blocked_stmt_expr;
7128
7129 /* Scope of outermost declarations of identifiers with variably
7130 modified type within this switch statement; if nonzero, case and
7131 default labels may not appear. */
7132 unsigned int blocked_vm;
7133
7134 /* The next node on the stack. */
7135 struct c_switch *next;
7136 };
7137
7138 /* A stack of the currently active switch statements. The innermost
7139 switch statement is on the top of the stack. There is no need to
7140 mark the stack for garbage collection because it is only active
7141 during the processing of the body of a function, and we never
7142 collect at that point. */
7143
7144 struct c_switch *c_switch_stack;
7145
7146 /* Start a C switch statement, testing expression EXP. Return the new
7147 SWITCH_EXPR. */
7148
7149 tree
c_start_case(tree exp)7150 c_start_case (tree exp)
7151 {
7152 tree orig_type = error_mark_node;
7153 struct c_switch *cs;
7154
7155 if (exp != error_mark_node)
7156 {
7157 orig_type = TREE_TYPE (exp);
7158
7159 if (!INTEGRAL_TYPE_P (orig_type))
7160 {
7161 if (orig_type != error_mark_node)
7162 {
7163 error ("switch quantity not an integer");
7164 orig_type = error_mark_node;
7165 }
7166 exp = integer_zero_node;
7167 }
7168 else
7169 {
7170 tree type = TYPE_MAIN_VARIANT (orig_type);
7171
7172 if (!in_system_header
7173 && (type == long_integer_type_node
7174 || type == long_unsigned_type_node))
7175 warning (OPT_Wtraditional, "%<long%> switch expression not "
7176 "converted to %<int%> in ISO C");
7177
7178 exp = default_conversion (exp);
7179 }
7180 }
7181
7182 /* Add this new SWITCH_EXPR to the stack. */
7183 cs = XNEW (struct c_switch);
7184 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7185 cs->orig_type = orig_type;
7186 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7187 cs->blocked_stmt_expr = 0;
7188 cs->blocked_vm = 0;
7189 cs->next = c_switch_stack;
7190 c_switch_stack = cs;
7191
7192 return add_stmt (cs->switch_expr);
7193 }
7194
7195 /* Process a case label. */
7196
7197 tree
do_case(tree low_value,tree high_value)7198 do_case (tree low_value, tree high_value)
7199 {
7200 tree label = NULL_TREE;
7201
7202 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7203 && !c_switch_stack->blocked_vm)
7204 {
7205 label = c_add_case_label (c_switch_stack->cases,
7206 SWITCH_COND (c_switch_stack->switch_expr),
7207 c_switch_stack->orig_type,
7208 low_value, high_value);
7209 if (label == error_mark_node)
7210 label = NULL_TREE;
7211 }
7212 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7213 {
7214 if (low_value)
7215 error ("case label in statement expression not containing "
7216 "enclosing switch statement");
7217 else
7218 error ("%<default%> label in statement expression not containing "
7219 "enclosing switch statement");
7220 }
7221 else if (c_switch_stack && c_switch_stack->blocked_vm)
7222 {
7223 if (low_value)
7224 error ("case label in scope of identifier with variably modified "
7225 "type not containing enclosing switch statement");
7226 else
7227 error ("%<default%> label in scope of identifier with variably "
7228 "modified type not containing enclosing switch statement");
7229 }
7230 else if (low_value)
7231 error ("case label not within a switch statement");
7232 else
7233 error ("%<default%> label not within a switch statement");
7234
7235 return label;
7236 }
7237
7238 /* Finish the switch statement. */
7239
7240 void
c_finish_case(tree body)7241 c_finish_case (tree body)
7242 {
7243 struct c_switch *cs = c_switch_stack;
7244 location_t switch_location;
7245
7246 SWITCH_BODY (cs->switch_expr) = body;
7247
7248 /* We must not be within a statement expression nested in the switch
7249 at this point; we might, however, be within the scope of an
7250 identifier with variably modified type nested in the switch. */
7251 gcc_assert (!cs->blocked_stmt_expr);
7252
7253 /* Emit warnings as needed. */
7254 if (EXPR_HAS_LOCATION (cs->switch_expr))
7255 switch_location = EXPR_LOCATION (cs->switch_expr);
7256 else
7257 switch_location = input_location;
7258 c_do_switch_warnings (cs->cases, switch_location,
7259 TREE_TYPE (cs->switch_expr),
7260 SWITCH_COND (cs->switch_expr));
7261
7262 /* Pop the stack. */
7263 c_switch_stack = cs->next;
7264 splay_tree_delete (cs->cases);
7265 XDELETE (cs);
7266 }
7267
7268 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7269 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7270 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7271 statement, and was not surrounded with parenthesis. */
7272
7273 void
c_finish_if_stmt(location_t if_locus,tree cond,tree then_block,tree else_block,bool nested_if)7274 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7275 tree else_block, bool nested_if)
7276 {
7277 tree stmt;
7278
7279 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7280 if (warn_parentheses && nested_if && else_block == NULL)
7281 {
7282 tree inner_if = then_block;
7283
7284 /* We know from the grammar productions that there is an IF nested
7285 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7286 it might not be exactly THEN_BLOCK, but should be the last
7287 non-container statement within. */
7288 while (1)
7289 switch (TREE_CODE (inner_if))
7290 {
7291 case COND_EXPR:
7292 goto found;
7293 case BIND_EXPR:
7294 inner_if = BIND_EXPR_BODY (inner_if);
7295 break;
7296 case STATEMENT_LIST:
7297 inner_if = expr_last (then_block);
7298 break;
7299 case TRY_FINALLY_EXPR:
7300 case TRY_CATCH_EXPR:
7301 inner_if = TREE_OPERAND (inner_if, 0);
7302 break;
7303 default:
7304 gcc_unreachable ();
7305 }
7306 found:
7307
7308 if (COND_EXPR_ELSE (inner_if))
7309 warning (OPT_Wparentheses,
7310 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7311 &if_locus);
7312 }
7313
7314 empty_body_warning (then_block, else_block);
7315
7316 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7317 SET_EXPR_LOCATION (stmt, if_locus);
7318 add_stmt (stmt);
7319 }
7320
7321 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7322 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7323 is false for DO loops. INCR is the FOR increment expression. BODY is
7324 the statement controlled by the loop. BLAB is the break label. CLAB is
7325 the continue label. Everything is allowed to be NULL. */
7326
7327 void
c_finish_loop(location_t start_locus,tree cond,tree incr,tree body,tree blab,tree clab,bool cond_is_first)7328 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7329 tree blab, tree clab, bool cond_is_first)
7330 {
7331 tree entry = NULL, exit = NULL, t;
7332
7333 /* If the condition is zero don't generate a loop construct. */
7334 if (cond && integer_zerop (cond))
7335 {
7336 if (cond_is_first)
7337 {
7338 t = build_and_jump (&blab);
7339 SET_EXPR_LOCATION (t, start_locus);
7340 add_stmt (t);
7341 }
7342 }
7343 else
7344 {
7345 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7346
7347 /* If we have an exit condition, then we build an IF with gotos either
7348 out of the loop, or to the top of it. If there's no exit condition,
7349 then we just build a jump back to the top. */
7350 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7351
7352 if (cond && !integer_nonzerop (cond))
7353 {
7354 /* Canonicalize the loop condition to the end. This means
7355 generating a branch to the loop condition. Reuse the
7356 continue label, if possible. */
7357 if (cond_is_first)
7358 {
7359 if (incr || !clab)
7360 {
7361 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7362 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7363 }
7364 else
7365 t = build1 (GOTO_EXPR, void_type_node, clab);
7366 SET_EXPR_LOCATION (t, start_locus);
7367 add_stmt (t);
7368 }
7369
7370 t = build_and_jump (&blab);
7371 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7372 if (cond_is_first)
7373 SET_EXPR_LOCATION (exit, start_locus);
7374 else
7375 SET_EXPR_LOCATION (exit, input_location);
7376 }
7377
7378 add_stmt (top);
7379 }
7380
7381 if (body)
7382 add_stmt (body);
7383 if (clab)
7384 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7385 if (incr)
7386 add_stmt (incr);
7387 if (entry)
7388 add_stmt (entry);
7389 if (exit)
7390 add_stmt (exit);
7391 if (blab)
7392 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7393 }
7394
7395 tree
c_finish_bc_stmt(tree * label_p,bool is_break)7396 c_finish_bc_stmt (tree *label_p, bool is_break)
7397 {
7398 bool skip;
7399 tree label = *label_p;
7400
7401 /* In switch statements break is sometimes stylistically used after
7402 a return statement. This can lead to spurious warnings about
7403 control reaching the end of a non-void function when it is
7404 inlined. Note that we are calling block_may_fallthru with
7405 language specific tree nodes; this works because
7406 block_may_fallthru returns true when given something it does not
7407 understand. */
7408 skip = !block_may_fallthru (cur_stmt_list);
7409
7410 if (!label)
7411 {
7412 if (!skip)
7413 *label_p = label = create_artificial_label ();
7414 }
7415 else if (TREE_CODE (label) == LABEL_DECL)
7416 ;
7417 else switch (TREE_INT_CST_LOW (label))
7418 {
7419 case 0:
7420 if (is_break)
7421 error ("break statement not within loop or switch");
7422 else
7423 error ("continue statement not within a loop");
7424 return NULL_TREE;
7425
7426 case 1:
7427 gcc_assert (is_break);
7428 error ("break statement used with OpenMP for loop");
7429 return NULL_TREE;
7430
7431 default:
7432 gcc_unreachable ();
7433 }
7434
7435 if (skip)
7436 return NULL_TREE;
7437
7438 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7439 }
7440
7441 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7442
7443 static void
emit_side_effect_warnings(tree expr)7444 emit_side_effect_warnings (tree expr)
7445 {
7446 if (expr == error_mark_node)
7447 ;
7448 else if (!TREE_SIDE_EFFECTS (expr))
7449 {
7450 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7451 warning (0, "%Hstatement with no effect",
7452 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7453 }
7454 else if (warn_unused_value)
7455 warn_if_unused_value (expr, input_location);
7456 }
7457
7458 /* Process an expression as if it were a complete statement. Emit
7459 diagnostics, but do not call ADD_STMT. */
7460
7461 tree
c_process_expr_stmt(tree expr)7462 c_process_expr_stmt (tree expr)
7463 {
7464 if (!expr)
7465 return NULL_TREE;
7466
7467 if (warn_sequence_point)
7468 verify_sequence_points (expr);
7469
7470 if (TREE_TYPE (expr) != error_mark_node
7471 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7472 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7473 error ("expression statement has incomplete type");
7474
7475 /* If we're not processing a statement expression, warn about unused values.
7476 Warnings for statement expressions will be emitted later, once we figure
7477 out which is the result. */
7478 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7479 && (extra_warnings || warn_unused_value))
7480 emit_side_effect_warnings (expr);
7481
7482 /* If the expression is not of a type to which we cannot assign a line
7483 number, wrap the thing in a no-op NOP_EXPR. */
7484 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7485 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7486
7487 if (EXPR_P (expr))
7488 SET_EXPR_LOCATION (expr, input_location);
7489
7490 return expr;
7491 }
7492
7493 /* Emit an expression as a statement. */
7494
7495 tree
c_finish_expr_stmt(tree expr)7496 c_finish_expr_stmt (tree expr)
7497 {
7498 if (expr)
7499 return add_stmt (c_process_expr_stmt (expr));
7500 else
7501 return NULL;
7502 }
7503
7504 /* Do the opposite and emit a statement as an expression. To begin,
7505 create a new binding level and return it. */
7506
7507 tree
c_begin_stmt_expr(void)7508 c_begin_stmt_expr (void)
7509 {
7510 tree ret;
7511 struct c_label_context_se *nstack;
7512 struct c_label_list *glist;
7513
7514 /* We must force a BLOCK for this level so that, if it is not expanded
7515 later, there is a way to turn off the entire subtree of blocks that
7516 are contained in it. */
7517 keep_next_level ();
7518 ret = c_begin_compound_stmt (true);
7519 if (c_switch_stack)
7520 {
7521 c_switch_stack->blocked_stmt_expr++;
7522 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7523 }
7524 for (glist = label_context_stack_se->labels_used;
7525 glist != NULL;
7526 glist = glist->next)
7527 {
7528 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7529 }
7530 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7531 nstack->labels_def = NULL;
7532 nstack->labels_used = NULL;
7533 nstack->next = label_context_stack_se;
7534 label_context_stack_se = nstack;
7535
7536 /* Mark the current statement list as belonging to a statement list. */
7537 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7538
7539 return ret;
7540 }
7541
7542 tree
c_finish_stmt_expr(tree body)7543 c_finish_stmt_expr (tree body)
7544 {
7545 tree last, type, tmp, val;
7546 tree *last_p;
7547 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7548
7549 body = c_end_compound_stmt (body, true);
7550 if (c_switch_stack)
7551 {
7552 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7553 c_switch_stack->blocked_stmt_expr--;
7554 }
7555 /* It is no longer possible to jump to labels defined within this
7556 statement expression. */
7557 for (dlist = label_context_stack_se->labels_def;
7558 dlist != NULL;
7559 dlist = dlist->next)
7560 {
7561 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7562 }
7563 /* It is again possible to define labels with a goto just outside
7564 this statement expression. */
7565 for (glist = label_context_stack_se->next->labels_used;
7566 glist != NULL;
7567 glist = glist->next)
7568 {
7569 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7570 glist_prev = glist;
7571 }
7572 if (glist_prev != NULL)
7573 glist_prev->next = label_context_stack_se->labels_used;
7574 else
7575 label_context_stack_se->next->labels_used
7576 = label_context_stack_se->labels_used;
7577 label_context_stack_se = label_context_stack_se->next;
7578
7579 /* Locate the last statement in BODY. See c_end_compound_stmt
7580 about always returning a BIND_EXPR. */
7581 last_p = &BIND_EXPR_BODY (body);
7582 last = BIND_EXPR_BODY (body);
7583
7584 continue_searching:
7585 if (TREE_CODE (last) == STATEMENT_LIST)
7586 {
7587 tree_stmt_iterator i;
7588
7589 /* This can happen with degenerate cases like ({ }). No value. */
7590 if (!TREE_SIDE_EFFECTS (last))
7591 return body;
7592
7593 /* If we're supposed to generate side effects warnings, process
7594 all of the statements except the last. */
7595 if (extra_warnings || warn_unused_value)
7596 {
7597 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7598 emit_side_effect_warnings (tsi_stmt (i));
7599 }
7600 else
7601 i = tsi_last (last);
7602 last_p = tsi_stmt_ptr (i);
7603 last = *last_p;
7604 }
7605
7606 /* If the end of the list is exception related, then the list was split
7607 by a call to push_cleanup. Continue searching. */
7608 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7609 || TREE_CODE (last) == TRY_CATCH_EXPR)
7610 {
7611 last_p = &TREE_OPERAND (last, 0);
7612 last = *last_p;
7613 goto continue_searching;
7614 }
7615
7616 /* In the case that the BIND_EXPR is not necessary, return the
7617 expression out from inside it. */
7618 if (last == error_mark_node
7619 || (last == BIND_EXPR_BODY (body)
7620 && BIND_EXPR_VARS (body) == NULL))
7621 {
7622 /* Do not warn if the return value of a statement expression is
7623 unused. */
7624 if (EXPR_P (last))
7625 TREE_NO_WARNING (last) = 1;
7626 return last;
7627 }
7628
7629 /* Extract the type of said expression. */
7630 type = TREE_TYPE (last);
7631
7632 /* If we're not returning a value at all, then the BIND_EXPR that
7633 we already have is a fine expression to return. */
7634 if (!type || VOID_TYPE_P (type))
7635 return body;
7636
7637 /* Now that we've located the expression containing the value, it seems
7638 silly to make voidify_wrapper_expr repeat the process. Create a
7639 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7640 tmp = create_tmp_var_raw (type, NULL);
7641
7642 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7643 tree_expr_nonnegative_p giving up immediately. */
7644 val = last;
7645 if (TREE_CODE (val) == NOP_EXPR
7646 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7647 val = TREE_OPERAND (val, 0);
7648
7649 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7650 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7651
7652 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7653 }
7654
7655 /* Begin the scope of an identifier of variably modified type, scope
7656 number SCOPE. Jumping from outside this scope to inside it is not
7657 permitted. */
7658
7659 void
c_begin_vm_scope(unsigned int scope)7660 c_begin_vm_scope (unsigned int scope)
7661 {
7662 struct c_label_context_vm *nstack;
7663 struct c_label_list *glist;
7664
7665 gcc_assert (scope > 0);
7666
7667 /* At file_scope, we don't have to do any processing. */
7668 if (label_context_stack_vm == NULL)
7669 return;
7670
7671 if (c_switch_stack && !c_switch_stack->blocked_vm)
7672 c_switch_stack->blocked_vm = scope;
7673 for (glist = label_context_stack_vm->labels_used;
7674 glist != NULL;
7675 glist = glist->next)
7676 {
7677 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7678 }
7679 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7680 nstack->labels_def = NULL;
7681 nstack->labels_used = NULL;
7682 nstack->scope = scope;
7683 nstack->next = label_context_stack_vm;
7684 label_context_stack_vm = nstack;
7685 }
7686
7687 /* End a scope which may contain identifiers of variably modified
7688 type, scope number SCOPE. */
7689
7690 void
c_end_vm_scope(unsigned int scope)7691 c_end_vm_scope (unsigned int scope)
7692 {
7693 if (label_context_stack_vm == NULL)
7694 return;
7695 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7696 c_switch_stack->blocked_vm = 0;
7697 /* We may have a number of nested scopes of identifiers with
7698 variably modified type, all at this depth. Pop each in turn. */
7699 while (label_context_stack_vm->scope == scope)
7700 {
7701 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7702
7703 /* It is no longer possible to jump to labels defined within this
7704 scope. */
7705 for (dlist = label_context_stack_vm->labels_def;
7706 dlist != NULL;
7707 dlist = dlist->next)
7708 {
7709 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7710 }
7711 /* It is again possible to define labels with a goto just outside
7712 this scope. */
7713 for (glist = label_context_stack_vm->next->labels_used;
7714 glist != NULL;
7715 glist = glist->next)
7716 {
7717 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7718 glist_prev = glist;
7719 }
7720 if (glist_prev != NULL)
7721 glist_prev->next = label_context_stack_vm->labels_used;
7722 else
7723 label_context_stack_vm->next->labels_used
7724 = label_context_stack_vm->labels_used;
7725 label_context_stack_vm = label_context_stack_vm->next;
7726 }
7727 }
7728
7729 /* Begin and end compound statements. This is as simple as pushing
7730 and popping new statement lists from the tree. */
7731
7732 tree
c_begin_compound_stmt(bool do_scope)7733 c_begin_compound_stmt (bool do_scope)
7734 {
7735 tree stmt = push_stmt_list ();
7736 if (do_scope)
7737 push_scope ();
7738 return stmt;
7739 }
7740
7741 tree
c_end_compound_stmt(tree stmt,bool do_scope)7742 c_end_compound_stmt (tree stmt, bool do_scope)
7743 {
7744 tree block = NULL;
7745
7746 if (do_scope)
7747 {
7748 if (c_dialect_objc ())
7749 objc_clear_super_receiver ();
7750 block = pop_scope ();
7751 }
7752
7753 stmt = pop_stmt_list (stmt);
7754 stmt = c_build_bind_expr (block, stmt);
7755
7756 /* If this compound statement is nested immediately inside a statement
7757 expression, then force a BIND_EXPR to be created. Otherwise we'll
7758 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7759 STATEMENT_LISTs merge, and thus we can lose track of what statement
7760 was really last. */
7761 if (cur_stmt_list
7762 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7763 && TREE_CODE (stmt) != BIND_EXPR)
7764 {
7765 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7766 TREE_SIDE_EFFECTS (stmt) = 1;
7767 }
7768
7769 return stmt;
7770 }
7771
7772 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7773 when the current scope is exited. EH_ONLY is true when this is not
7774 meant to apply to normal control flow transfer. */
7775
7776 void
push_cleanup(tree ARG_UNUSED (decl),tree cleanup,bool eh_only)7777 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7778 {
7779 enum tree_code code;
7780 tree stmt, list;
7781 bool stmt_expr;
7782
7783 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7784 stmt = build_stmt (code, NULL, cleanup);
7785 add_stmt (stmt);
7786 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7787 list = push_stmt_list ();
7788 TREE_OPERAND (stmt, 0) = list;
7789 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7790 }
7791
7792 /* Build a binary-operation expression without default conversions.
7793 CODE is the kind of expression to build.
7794 This function differs from `build' in several ways:
7795 the data type of the result is computed and recorded in it,
7796 warnings are generated if arg data types are invalid,
7797 special handling for addition and subtraction of pointers is known,
7798 and some optimization is done (operations on narrow ints
7799 are done in the narrower type when that gives the same result).
7800 Constant folding is also done before the result is returned.
7801
7802 Note that the operands will never have enumeral types, or function
7803 or array types, because either they will have the default conversions
7804 performed or they have both just been converted to some other type in which
7805 the arithmetic is to be done. */
7806
7807 tree
build_binary_op(enum tree_code code,tree orig_op0,tree orig_op1,int convert_p)7808 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7809 int convert_p)
7810 {
7811 tree type0, type1;
7812 enum tree_code code0, code1;
7813 tree op0, op1;
7814 const char *invalid_op_diag;
7815
7816 /* Expression code to give to the expression when it is built.
7817 Normally this is CODE, which is what the caller asked for,
7818 but in some special cases we change it. */
7819 enum tree_code resultcode = code;
7820
7821 /* Data type in which the computation is to be performed.
7822 In the simplest cases this is the common type of the arguments. */
7823 tree result_type = NULL;
7824
7825 /* Nonzero means operands have already been type-converted
7826 in whatever way is necessary.
7827 Zero means they need to be converted to RESULT_TYPE. */
7828 int converted = 0;
7829
7830 /* Nonzero means create the expression with this type, rather than
7831 RESULT_TYPE. */
7832 tree build_type = 0;
7833
7834 /* Nonzero means after finally constructing the expression
7835 convert it to this type. */
7836 tree final_type = 0;
7837
7838 /* Nonzero if this is an operation like MIN or MAX which can
7839 safely be computed in short if both args are promoted shorts.
7840 Also implies COMMON.
7841 -1 indicates a bitwise operation; this makes a difference
7842 in the exact conditions for when it is safe to do the operation
7843 in a narrower mode. */
7844 int shorten = 0;
7845
7846 /* Nonzero if this is a comparison operation;
7847 if both args are promoted shorts, compare the original shorts.
7848 Also implies COMMON. */
7849 int short_compare = 0;
7850
7851 /* Nonzero if this is a right-shift operation, which can be computed on the
7852 original short and then promoted if the operand is a promoted short. */
7853 int short_shift = 0;
7854
7855 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7856 int common = 0;
7857
7858 /* True means types are compatible as far as ObjC is concerned. */
7859 bool objc_ok;
7860
7861 if (convert_p)
7862 {
7863 op0 = default_conversion (orig_op0);
7864 op1 = default_conversion (orig_op1);
7865 }
7866 else
7867 {
7868 op0 = orig_op0;
7869 op1 = orig_op1;
7870 }
7871
7872 type0 = TREE_TYPE (op0);
7873 type1 = TREE_TYPE (op1);
7874
7875 /* The expression codes of the data types of the arguments tell us
7876 whether the arguments are integers, floating, pointers, etc. */
7877 code0 = TREE_CODE (type0);
7878 code1 = TREE_CODE (type1);
7879
7880 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7881 STRIP_TYPE_NOPS (op0);
7882 STRIP_TYPE_NOPS (op1);
7883
7884 /* If an error was already reported for one of the arguments,
7885 avoid reporting another error. */
7886
7887 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7888 return error_mark_node;
7889
7890 if ((invalid_op_diag
7891 = targetm.invalid_binary_op (code, type0, type1)))
7892 {
7893 error (invalid_op_diag);
7894 return error_mark_node;
7895 }
7896
7897 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
7898
7899 switch (code)
7900 {
7901 case PLUS_EXPR:
7902 /* Handle the pointer + int case. */
7903 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7904 return pointer_int_sum (PLUS_EXPR, op0, op1);
7905 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
7906 return pointer_int_sum (PLUS_EXPR, op1, op0);
7907 else
7908 common = 1;
7909 break;
7910
7911 case MINUS_EXPR:
7912 /* Subtraction of two similar pointers.
7913 We must subtract them as integers, then divide by object size. */
7914 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
7915 && comp_target_types (type0, type1))
7916 return pointer_diff (op0, op1);
7917 /* Handle pointer minus int. Just like pointer plus int. */
7918 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7919 return pointer_int_sum (MINUS_EXPR, op0, op1);
7920 else
7921 common = 1;
7922 break;
7923
7924 case MULT_EXPR:
7925 common = 1;
7926 break;
7927
7928 case TRUNC_DIV_EXPR:
7929 case CEIL_DIV_EXPR:
7930 case FLOOR_DIV_EXPR:
7931 case ROUND_DIV_EXPR:
7932 case EXACT_DIV_EXPR:
7933 /* Floating point division by zero is a legitimate way to obtain
7934 infinities and NaNs. */
7935 if (skip_evaluation == 0 && integer_zerop (op1))
7936 warning (OPT_Wdiv_by_zero, "division by zero");
7937
7938 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7939 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7940 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7941 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
7942 {
7943 enum tree_code tcode0 = code0, tcode1 = code1;
7944
7945 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7946 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
7947 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
7948 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
7949
7950 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
7951 resultcode = RDIV_EXPR;
7952 else
7953 /* Although it would be tempting to shorten always here, that
7954 loses on some targets, since the modulo instruction is
7955 undefined if the quotient can't be represented in the
7956 computation mode. We shorten only if unsigned or if
7957 dividing by something we know != -1. */
7958 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7959 || (TREE_CODE (op1) == INTEGER_CST
7960 && !integer_all_onesp (op1)));
7961 common = 1;
7962 }
7963 break;
7964
7965 case BIT_AND_EXPR:
7966 case BIT_IOR_EXPR:
7967 case BIT_XOR_EXPR:
7968 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7969 shorten = -1;
7970 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
7971 common = 1;
7972 break;
7973
7974 case TRUNC_MOD_EXPR:
7975 case FLOOR_MOD_EXPR:
7976 if (skip_evaluation == 0 && integer_zerop (op1))
7977 warning (OPT_Wdiv_by_zero, "division by zero");
7978
7979 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7980 {
7981 /* Although it would be tempting to shorten always here, that loses
7982 on some targets, since the modulo instruction is undefined if the
7983 quotient can't be represented in the computation mode. We shorten
7984 only if unsigned or if dividing by something we know != -1. */
7985 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7986 || (TREE_CODE (op1) == INTEGER_CST
7987 && !integer_all_onesp (op1)));
7988 common = 1;
7989 }
7990 break;
7991
7992 case TRUTH_ANDIF_EXPR:
7993 case TRUTH_ORIF_EXPR:
7994 case TRUTH_AND_EXPR:
7995 case TRUTH_OR_EXPR:
7996 case TRUTH_XOR_EXPR:
7997 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
7998 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
7999 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
8000 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
8001 {
8002 /* Result of these operations is always an int,
8003 but that does not mean the operands should be
8004 converted to ints! */
8005 result_type = integer_type_node;
8006 op0 = c_common_truthvalue_conversion (op0);
8007 op1 = c_common_truthvalue_conversion (op1);
8008 converted = 1;
8009 }
8010 break;
8011
8012 /* Shift operations: result has same type as first operand;
8013 always convert second operand to int.
8014 Also set SHORT_SHIFT if shifting rightward. */
8015
8016 case RSHIFT_EXPR:
8017 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8018 {
8019 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8020 {
8021 if (tree_int_cst_sgn (op1) < 0)
8022 warning (0, "right shift count is negative");
8023 else
8024 {
8025 if (!integer_zerop (op1))
8026 short_shift = 1;
8027
8028 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8029 warning (0, "right shift count >= width of type");
8030 }
8031 }
8032
8033 /* Use the type of the value to be shifted. */
8034 result_type = type0;
8035 /* Convert the shift-count to an integer, regardless of size
8036 of value being shifted. */
8037 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8038 op1 = convert (integer_type_node, op1);
8039 /* Avoid converting op1 to result_type later. */
8040 converted = 1;
8041 }
8042 break;
8043
8044 case LSHIFT_EXPR:
8045 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
8046 {
8047 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
8048 {
8049 if (tree_int_cst_sgn (op1) < 0)
8050 warning (0, "left shift count is negative");
8051
8052 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
8053 warning (0, "left shift count >= width of type");
8054 }
8055
8056 /* Use the type of the value to be shifted. */
8057 result_type = type0;
8058 /* Convert the shift-count to an integer, regardless of size
8059 of value being shifted. */
8060 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
8061 op1 = convert (integer_type_node, op1);
8062 /* Avoid converting op1 to result_type later. */
8063 converted = 1;
8064 }
8065 break;
8066
8067 case EQ_EXPR:
8068 case NE_EXPR:
8069 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
8070 warning (OPT_Wfloat_equal,
8071 "comparing floating point with == or != is unsafe");
8072 /* Result of comparison is always int,
8073 but don't convert the args to int! */
8074 build_type = integer_type_node;
8075 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8076 || code0 == COMPLEX_TYPE)
8077 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8078 || code1 == COMPLEX_TYPE))
8079 short_compare = 1;
8080 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8081 {
8082 tree tt0 = TREE_TYPE (type0);
8083 tree tt1 = TREE_TYPE (type1);
8084 /* Anything compares with void *. void * compares with anything.
8085 Otherwise, the targets must be compatible
8086 and both must be object or both incomplete. */
8087 if (comp_target_types (type0, type1))
8088 result_type = common_pointer_type (type0, type1);
8089 else if (VOID_TYPE_P (tt0))
8090 {
8091 /* op0 != orig_op0 detects the case of something
8092 whose value is 0 but which isn't a valid null ptr const. */
8093 if (pedantic && !null_pointer_constant_p (orig_op0)
8094 && TREE_CODE (tt1) == FUNCTION_TYPE)
8095 pedwarn ("ISO C forbids comparison of %<void *%>"
8096 " with function pointer");
8097 }
8098 else if (VOID_TYPE_P (tt1))
8099 {
8100 if (pedantic && !null_pointer_constant_p (orig_op1)
8101 && TREE_CODE (tt0) == FUNCTION_TYPE)
8102 pedwarn ("ISO C forbids comparison of %<void *%>"
8103 " with function pointer");
8104 }
8105 else
8106 /* Avoid warning about the volatile ObjC EH puts on decls. */
8107 if (!objc_ok)
8108 pedwarn ("comparison of distinct pointer types lacks a cast");
8109
8110 if (result_type == NULL_TREE)
8111 result_type = ptr_type_node;
8112 }
8113 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8114 {
8115 if (TREE_CODE (op0) == ADDR_EXPR
8116 && DECL_P (TREE_OPERAND (op0, 0))
8117 && (TREE_CODE (TREE_OPERAND (op0, 0)) == PARM_DECL
8118 || TREE_CODE (TREE_OPERAND (op0, 0)) == LABEL_DECL
8119 || !DECL_WEAK (TREE_OPERAND (op0, 0))))
8120 warning (OPT_Waddress, "the address of %qD will never be NULL",
8121 TREE_OPERAND (op0, 0));
8122 result_type = type0;
8123 }
8124 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8125 {
8126 if (TREE_CODE (op1) == ADDR_EXPR
8127 && DECL_P (TREE_OPERAND (op1, 0))
8128 && (TREE_CODE (TREE_OPERAND (op1, 0)) == PARM_DECL
8129 || TREE_CODE (TREE_OPERAND (op1, 0)) == LABEL_DECL
8130 || !DECL_WEAK (TREE_OPERAND (op1, 0))))
8131 warning (OPT_Waddress, "the address of %qD will never be NULL",
8132 TREE_OPERAND (op1, 0));
8133 result_type = type1;
8134 }
8135 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8136 {
8137 result_type = type0;
8138 pedwarn ("comparison between pointer and integer");
8139 }
8140 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8141 {
8142 result_type = type1;
8143 pedwarn ("comparison between pointer and integer");
8144 }
8145 break;
8146
8147 case LE_EXPR:
8148 case GE_EXPR:
8149 case LT_EXPR:
8150 case GT_EXPR:
8151 build_type = integer_type_node;
8152 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
8153 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
8154 short_compare = 1;
8155 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8156 {
8157 if (comp_target_types (type0, type1))
8158 {
8159 result_type = common_pointer_type (type0, type1);
8160 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8161 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8162 pedwarn ("comparison of complete and incomplete pointers");
8163 else if (pedantic
8164 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8165 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
8166 }
8167 else
8168 {
8169 result_type = ptr_type_node;
8170 pedwarn ("comparison of distinct pointer types lacks a cast");
8171 }
8172 }
8173 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8174 {
8175 result_type = type0;
8176 if (pedantic || extra_warnings)
8177 pedwarn ("ordered comparison of pointer with integer zero");
8178 }
8179 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8180 {
8181 result_type = type1;
8182 if (pedantic)
8183 pedwarn ("ordered comparison of pointer with integer zero");
8184 }
8185 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8186 {
8187 result_type = type0;
8188 pedwarn ("comparison between pointer and integer");
8189 }
8190 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8191 {
8192 result_type = type1;
8193 pedwarn ("comparison between pointer and integer");
8194 }
8195 break;
8196
8197 default:
8198 gcc_unreachable ();
8199 }
8200
8201 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8202 return error_mark_node;
8203
8204 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8205 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8206 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8207 TREE_TYPE (type1))))
8208 {
8209 binary_op_error (code);
8210 return error_mark_node;
8211 }
8212
8213 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8214 || code0 == VECTOR_TYPE)
8215 &&
8216 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8217 || code1 == VECTOR_TYPE))
8218 {
8219 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8220
8221 if (shorten || common || short_compare)
8222 result_type = c_common_type (type0, type1);
8223
8224 /* For certain operations (which identify themselves by shorten != 0)
8225 if both args were extended from the same smaller type,
8226 do the arithmetic in that type and then extend.
8227
8228 shorten !=0 and !=1 indicates a bitwise operation.
8229 For them, this optimization is safe only if
8230 both args are zero-extended or both are sign-extended.
8231 Otherwise, we might change the result.
8232 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8233 but calculated in (unsigned short) it would be (unsigned short)-1. */
8234
8235 if (shorten && none_complex)
8236 {
8237 int unsigned0, unsigned1;
8238 tree arg0, arg1;
8239 int uns;
8240 tree type;
8241
8242 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8243 excessive narrowing when we call get_narrower below. For
8244 example, suppose that OP0 is of unsigned int extended
8245 from signed char and that RESULT_TYPE is long long int.
8246 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8247 like
8248
8249 (long long int) (unsigned int) signed_char
8250
8251 which get_narrower would narrow down to
8252
8253 (unsigned int) signed char
8254
8255 If we do not cast OP0 first, get_narrower would return
8256 signed_char, which is inconsistent with the case of the
8257 explicit cast. */
8258 op0 = convert (result_type, op0);
8259 op1 = convert (result_type, op1);
8260
8261 arg0 = get_narrower (op0, &unsigned0);
8262 arg1 = get_narrower (op1, &unsigned1);
8263
8264 /* UNS is 1 if the operation to be done is an unsigned one. */
8265 uns = TYPE_UNSIGNED (result_type);
8266
8267 final_type = result_type;
8268
8269 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8270 but it *requires* conversion to FINAL_TYPE. */
8271
8272 if ((TYPE_PRECISION (TREE_TYPE (op0))
8273 == TYPE_PRECISION (TREE_TYPE (arg0)))
8274 && TREE_TYPE (op0) != final_type)
8275 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
8276 if ((TYPE_PRECISION (TREE_TYPE (op1))
8277 == TYPE_PRECISION (TREE_TYPE (arg1)))
8278 && TREE_TYPE (op1) != final_type)
8279 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
8280
8281 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8282
8283 /* For bitwise operations, signedness of nominal type
8284 does not matter. Consider only how operands were extended. */
8285 if (shorten == -1)
8286 uns = unsigned0;
8287
8288 /* Note that in all three cases below we refrain from optimizing
8289 an unsigned operation on sign-extended args.
8290 That would not be valid. */
8291
8292 /* Both args variable: if both extended in same way
8293 from same width, do it in that width.
8294 Do it unsigned if args were zero-extended. */
8295 if ((TYPE_PRECISION (TREE_TYPE (arg0))
8296 < TYPE_PRECISION (result_type))
8297 && (TYPE_PRECISION (TREE_TYPE (arg1))
8298 == TYPE_PRECISION (TREE_TYPE (arg0)))
8299 && unsigned0 == unsigned1
8300 && (unsigned0 || !uns))
8301 result_type
8302 = c_common_signed_or_unsigned_type
8303 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
8304 else if (TREE_CODE (arg0) == INTEGER_CST
8305 && (unsigned1 || !uns)
8306 && (TYPE_PRECISION (TREE_TYPE (arg1))
8307 < TYPE_PRECISION (result_type))
8308 && (type
8309 = c_common_signed_or_unsigned_type (unsigned1,
8310 TREE_TYPE (arg1)),
8311 int_fits_type_p (arg0, type)))
8312 result_type = type;
8313 else if (TREE_CODE (arg1) == INTEGER_CST
8314 && (unsigned0 || !uns)
8315 && (TYPE_PRECISION (TREE_TYPE (arg0))
8316 < TYPE_PRECISION (result_type))
8317 && (type
8318 = c_common_signed_or_unsigned_type (unsigned0,
8319 TREE_TYPE (arg0)),
8320 int_fits_type_p (arg1, type)))
8321 result_type = type;
8322 }
8323
8324 /* Shifts can be shortened if shifting right. */
8325
8326 if (short_shift)
8327 {
8328 int unsigned_arg;
8329 tree arg0 = get_narrower (op0, &unsigned_arg);
8330
8331 final_type = result_type;
8332
8333 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8334 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8335
8336 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8337 /* We can shorten only if the shift count is less than the
8338 number of bits in the smaller type size. */
8339 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8340 /* We cannot drop an unsigned shift after sign-extension. */
8341 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8342 {
8343 /* Do an unsigned shift if the operand was zero-extended. */
8344 result_type
8345 = c_common_signed_or_unsigned_type (unsigned_arg,
8346 TREE_TYPE (arg0));
8347 /* Convert value-to-be-shifted to that type. */
8348 if (TREE_TYPE (op0) != result_type)
8349 op0 = convert (result_type, op0);
8350 converted = 1;
8351 }
8352 }
8353
8354 /* Comparison operations are shortened too but differently.
8355 They identify themselves by setting short_compare = 1. */
8356
8357 if (short_compare)
8358 {
8359 /* Don't write &op0, etc., because that would prevent op0
8360 from being kept in a register.
8361 Instead, make copies of the our local variables and
8362 pass the copies by reference, then copy them back afterward. */
8363 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8364 enum tree_code xresultcode = resultcode;
8365 tree val
8366 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8367
8368 if (val != 0)
8369 return val;
8370
8371 op0 = xop0, op1 = xop1;
8372 converted = 1;
8373 resultcode = xresultcode;
8374
8375 if (warn_sign_compare && skip_evaluation == 0)
8376 {
8377 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8378 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8379 int unsignedp0, unsignedp1;
8380 tree primop0 = get_narrower (op0, &unsignedp0);
8381 tree primop1 = get_narrower (op1, &unsignedp1);
8382
8383 xop0 = orig_op0;
8384 xop1 = orig_op1;
8385 STRIP_TYPE_NOPS (xop0);
8386 STRIP_TYPE_NOPS (xop1);
8387
8388 /* Give warnings for comparisons between signed and unsigned
8389 quantities that may fail.
8390
8391 Do the checking based on the original operand trees, so that
8392 casts will be considered, but default promotions won't be.
8393
8394 Do not warn if the comparison is being done in a signed type,
8395 since the signed type will only be chosen if it can represent
8396 all the values of the unsigned type. */
8397 if (!TYPE_UNSIGNED (result_type))
8398 /* OK */;
8399 /* Do not warn if both operands are the same signedness. */
8400 else if (op0_signed == op1_signed)
8401 /* OK */;
8402 else
8403 {
8404 tree sop, uop;
8405 bool ovf;
8406
8407 if (op0_signed)
8408 sop = xop0, uop = xop1;
8409 else
8410 sop = xop1, uop = xop0;
8411
8412 /* Do not warn if the signed quantity is an
8413 unsuffixed integer literal (or some static
8414 constant expression involving such literals or a
8415 conditional expression involving such literals)
8416 and it is non-negative. */
8417 if (tree_expr_nonnegative_warnv_p (sop, &ovf))
8418 /* OK */;
8419 /* Do not warn if the comparison is an equality operation,
8420 the unsigned quantity is an integral constant, and it
8421 would fit in the result if the result were signed. */
8422 else if (TREE_CODE (uop) == INTEGER_CST
8423 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8424 && int_fits_type_p
8425 (uop, c_common_signed_type (result_type)))
8426 /* OK */;
8427 /* Do not warn if the unsigned quantity is an enumeration
8428 constant and its maximum value would fit in the result
8429 if the result were signed. */
8430 else if (TREE_CODE (uop) == INTEGER_CST
8431 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8432 && int_fits_type_p
8433 (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8434 c_common_signed_type (result_type)))
8435 /* OK */;
8436 else
8437 warning (0, "comparison between signed and unsigned");
8438 }
8439
8440 /* Warn if two unsigned values are being compared in a size
8441 larger than their original size, and one (and only one) is the
8442 result of a `~' operator. This comparison will always fail.
8443
8444 Also warn if one operand is a constant, and the constant
8445 does not have all bits set that are set in the ~ operand
8446 when it is extended. */
8447
8448 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
8449 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
8450 {
8451 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
8452 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
8453 &unsignedp0);
8454 else
8455 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
8456 &unsignedp1);
8457
8458 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
8459 {
8460 tree primop;
8461 HOST_WIDE_INT constant, mask;
8462 int unsignedp, bits;
8463
8464 if (host_integerp (primop0, 0))
8465 {
8466 primop = primop1;
8467 unsignedp = unsignedp1;
8468 constant = tree_low_cst (primop0, 0);
8469 }
8470 else
8471 {
8472 primop = primop0;
8473 unsignedp = unsignedp0;
8474 constant = tree_low_cst (primop1, 0);
8475 }
8476
8477 bits = TYPE_PRECISION (TREE_TYPE (primop));
8478 if (bits < TYPE_PRECISION (result_type)
8479 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
8480 {
8481 mask = (~(HOST_WIDE_INT) 0) << bits;
8482 if ((mask & constant) != mask)
8483 warning (0, "comparison of promoted ~unsigned with constant");
8484 }
8485 }
8486 else if (unsignedp0 && unsignedp1
8487 && (TYPE_PRECISION (TREE_TYPE (primop0))
8488 < TYPE_PRECISION (result_type))
8489 && (TYPE_PRECISION (TREE_TYPE (primop1))
8490 < TYPE_PRECISION (result_type)))
8491 warning (0, "comparison of promoted ~unsigned with unsigned");
8492 }
8493 }
8494 }
8495 }
8496
8497 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8498 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8499 Then the expression will be built.
8500 It will be given type FINAL_TYPE if that is nonzero;
8501 otherwise, it will be given type RESULT_TYPE. */
8502
8503 if (!result_type)
8504 {
8505 binary_op_error (code);
8506 return error_mark_node;
8507 }
8508
8509 if (!converted)
8510 {
8511 if (TREE_TYPE (op0) != result_type)
8512 op0 = convert_and_check (result_type, op0);
8513 if (TREE_TYPE (op1) != result_type)
8514 op1 = convert_and_check (result_type, op1);
8515
8516 /* This can happen if one operand has a vector type, and the other
8517 has a different type. */
8518 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8519 return error_mark_node;
8520 }
8521
8522 if (build_type == NULL_TREE)
8523 build_type = result_type;
8524
8525 {
8526 /* Treat expressions in initializers specially as they can't trap. */
8527 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8528 build_type,
8529 op0, op1)
8530 : fold_build2 (resultcode, build_type,
8531 op0, op1);
8532
8533 if (final_type != 0)
8534 result = convert (final_type, result);
8535 return result;
8536 }
8537 }
8538
8539
8540 /* Convert EXPR to be a truth-value, validating its type for this
8541 purpose. */
8542
8543 tree
c_objc_common_truthvalue_conversion(tree expr)8544 c_objc_common_truthvalue_conversion (tree expr)
8545 {
8546 switch (TREE_CODE (TREE_TYPE (expr)))
8547 {
8548 case ARRAY_TYPE:
8549 error ("used array that cannot be converted to pointer where scalar is required");
8550 return error_mark_node;
8551
8552 case RECORD_TYPE:
8553 error ("used struct type value where scalar is required");
8554 return error_mark_node;
8555
8556 case UNION_TYPE:
8557 error ("used union type value where scalar is required");
8558 return error_mark_node;
8559
8560 case FUNCTION_TYPE:
8561 gcc_unreachable ();
8562
8563 default:
8564 break;
8565 }
8566
8567 /* ??? Should we also give an error for void and vectors rather than
8568 leaving those to give errors later? */
8569 return c_common_truthvalue_conversion (expr);
8570 }
8571
8572
8573 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8574 required. */
8575
8576 tree
c_expr_to_decl(tree expr,bool * tc ATTRIBUTE_UNUSED,bool * ti ATTRIBUTE_UNUSED,bool * se)8577 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
8578 bool *ti ATTRIBUTE_UNUSED, bool *se)
8579 {
8580 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8581 {
8582 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8583 /* Executing a compound literal inside a function reinitializes
8584 it. */
8585 if (!TREE_STATIC (decl))
8586 *se = true;
8587 return decl;
8588 }
8589 else
8590 return expr;
8591 }
8592
8593 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8594
8595 tree
c_begin_omp_parallel(void)8596 c_begin_omp_parallel (void)
8597 {
8598 tree block;
8599
8600 keep_next_level ();
8601 block = c_begin_compound_stmt (true);
8602
8603 return block;
8604 }
8605
8606 tree
c_finish_omp_parallel(tree clauses,tree block)8607 c_finish_omp_parallel (tree clauses, tree block)
8608 {
8609 tree stmt;
8610
8611 block = c_end_compound_stmt (block, true);
8612
8613 stmt = make_node (OMP_PARALLEL);
8614 TREE_TYPE (stmt) = void_type_node;
8615 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8616 OMP_PARALLEL_BODY (stmt) = block;
8617
8618 return add_stmt (stmt);
8619 }
8620
8621 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8622 Remove any elements from the list that are invalid. */
8623
8624 tree
c_finish_omp_clauses(tree clauses)8625 c_finish_omp_clauses (tree clauses)
8626 {
8627 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8628 tree c, t, *pc = &clauses;
8629 const char *name;
8630
8631 bitmap_obstack_initialize (NULL);
8632 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8633 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8634 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8635
8636 for (pc = &clauses, c = clauses; c ; c = *pc)
8637 {
8638 bool remove = false;
8639 bool need_complete = false;
8640 bool need_implicitly_determined = false;
8641
8642 switch (OMP_CLAUSE_CODE (c))
8643 {
8644 case OMP_CLAUSE_SHARED:
8645 name = "shared";
8646 need_implicitly_determined = true;
8647 goto check_dup_generic;
8648
8649 case OMP_CLAUSE_PRIVATE:
8650 name = "private";
8651 need_complete = true;
8652 need_implicitly_determined = true;
8653 goto check_dup_generic;
8654
8655 case OMP_CLAUSE_REDUCTION:
8656 name = "reduction";
8657 need_implicitly_determined = true;
8658 t = OMP_CLAUSE_DECL (c);
8659 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8660 || POINTER_TYPE_P (TREE_TYPE (t)))
8661 {
8662 error ("%qE has invalid type for %<reduction%>", t);
8663 remove = true;
8664 }
8665 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8666 {
8667 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8668 const char *r_name = NULL;
8669
8670 switch (r_code)
8671 {
8672 case PLUS_EXPR:
8673 case MULT_EXPR:
8674 case MINUS_EXPR:
8675 break;
8676 case BIT_AND_EXPR:
8677 r_name = "&";
8678 break;
8679 case BIT_XOR_EXPR:
8680 r_name = "^";
8681 break;
8682 case BIT_IOR_EXPR:
8683 r_name = "|";
8684 break;
8685 case TRUTH_ANDIF_EXPR:
8686 r_name = "&&";
8687 break;
8688 case TRUTH_ORIF_EXPR:
8689 r_name = "||";
8690 break;
8691 default:
8692 gcc_unreachable ();
8693 }
8694 if (r_name)
8695 {
8696 error ("%qE has invalid type for %<reduction(%s)%>",
8697 t, r_name);
8698 remove = true;
8699 }
8700 }
8701 goto check_dup_generic;
8702
8703 case OMP_CLAUSE_COPYPRIVATE:
8704 name = "copyprivate";
8705 goto check_dup_generic;
8706
8707 case OMP_CLAUSE_COPYIN:
8708 name = "copyin";
8709 t = OMP_CLAUSE_DECL (c);
8710 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8711 {
8712 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8713 remove = true;
8714 }
8715 goto check_dup_generic;
8716
8717 check_dup_generic:
8718 t = OMP_CLAUSE_DECL (c);
8719 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8720 {
8721 error ("%qE is not a variable in clause %qs", t, name);
8722 remove = true;
8723 }
8724 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8725 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8726 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8727 {
8728 error ("%qE appears more than once in data clauses", t);
8729 remove = true;
8730 }
8731 else
8732 bitmap_set_bit (&generic_head, DECL_UID (t));
8733 break;
8734
8735 case OMP_CLAUSE_FIRSTPRIVATE:
8736 name = "firstprivate";
8737 t = OMP_CLAUSE_DECL (c);
8738 need_complete = true;
8739 need_implicitly_determined = true;
8740 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8741 {
8742 error ("%qE is not a variable in clause %<firstprivate%>", t);
8743 remove = true;
8744 }
8745 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8746 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8747 {
8748 error ("%qE appears more than once in data clauses", t);
8749 remove = true;
8750 }
8751 else
8752 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8753 break;
8754
8755 case OMP_CLAUSE_LASTPRIVATE:
8756 name = "lastprivate";
8757 t = OMP_CLAUSE_DECL (c);
8758 need_complete = true;
8759 need_implicitly_determined = true;
8760 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8761 {
8762 error ("%qE is not a variable in clause %<lastprivate%>", t);
8763 remove = true;
8764 }
8765 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8766 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8767 {
8768 error ("%qE appears more than once in data clauses", t);
8769 remove = true;
8770 }
8771 else
8772 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8773 break;
8774
8775 case OMP_CLAUSE_IF:
8776 case OMP_CLAUSE_NUM_THREADS:
8777 case OMP_CLAUSE_SCHEDULE:
8778 case OMP_CLAUSE_NOWAIT:
8779 case OMP_CLAUSE_ORDERED:
8780 case OMP_CLAUSE_DEFAULT:
8781 pc = &OMP_CLAUSE_CHAIN (c);
8782 continue;
8783
8784 default:
8785 gcc_unreachable ();
8786 }
8787
8788 if (!remove)
8789 {
8790 t = OMP_CLAUSE_DECL (c);
8791
8792 if (need_complete)
8793 {
8794 t = require_complete_type (t);
8795 if (t == error_mark_node)
8796 remove = true;
8797 }
8798
8799 if (need_implicitly_determined)
8800 {
8801 const char *share_name = NULL;
8802
8803 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8804 share_name = "threadprivate";
8805 else switch (c_omp_predetermined_sharing (t))
8806 {
8807 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8808 break;
8809 case OMP_CLAUSE_DEFAULT_SHARED:
8810 share_name = "shared";
8811 break;
8812 case OMP_CLAUSE_DEFAULT_PRIVATE:
8813 share_name = "private";
8814 break;
8815 default:
8816 gcc_unreachable ();
8817 }
8818 if (share_name)
8819 {
8820 error ("%qE is predetermined %qs for %qs",
8821 t, share_name, name);
8822 remove = true;
8823 }
8824 }
8825 }
8826
8827 if (remove)
8828 *pc = OMP_CLAUSE_CHAIN (c);
8829 else
8830 pc = &OMP_CLAUSE_CHAIN (c);
8831 }
8832
8833 bitmap_obstack_release (NULL);
8834 return clauses;
8835 }
8836