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re PR c/30427 (~ vector float is accepted)
[gcc.git] / gcc / c-typeck.c
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22
23 /* This file is part of the C front end.
24 It contains routines to build C expressions given their operands,
25 including computing the types of the result, C-specific error checks,
26 and some optimization. */
27
28 #include "config.h"
29 #include "system.h"
30 #include "coretypes.h"
31 #include "tm.h"
32 #include "rtl.h"
33 #include "tree.h"
34 #include "langhooks.h"
35 #include "c-tree.h"
36 #include "tm_p.h"
37 #include "flags.h"
38 #include "output.h"
39 #include "expr.h"
40 #include "toplev.h"
41 #include "intl.h"
42 #include "ggc.h"
43 #include "target.h"
44 #include "tree-iterator.h"
45 #include "tree-gimple.h"
46 #include "tree-flow.h"
47
48 /* Possible cases of implicit bad conversions. Used to select
49 diagnostic messages in convert_for_assignment. */
50 enum impl_conv {
51 ic_argpass,
52 ic_argpass_nonproto,
53 ic_assign,
54 ic_init,
55 ic_return
56 };
57
58 /* The level of nesting inside "__alignof__". */
59 int in_alignof;
60
61 /* The level of nesting inside "sizeof". */
62 int in_sizeof;
63
64 /* The level of nesting inside "typeof". */
65 int in_typeof;
66
67 struct c_label_context_se *label_context_stack_se;
68 struct c_label_context_vm *label_context_stack_vm;
69
70 /* Nonzero if we've already printed a "missing braces around initializer"
71 message within this initializer. */
72 static int missing_braces_mentioned;
73
74 static int require_constant_value;
75 static int require_constant_elements;
76
77 static bool null_pointer_constant_p (tree);
78 static tree qualify_type (tree, tree);
79 static int tagged_types_tu_compatible_p (tree, tree);
80 static int comp_target_types (tree, tree);
81 static int function_types_compatible_p (tree, tree);
82 static int type_lists_compatible_p (tree, tree);
83 static tree decl_constant_value_for_broken_optimization (tree);
84 static tree lookup_field (tree, tree);
85 static int convert_arguments (int, tree *, tree, tree, tree, tree);
86 static tree pointer_diff (tree, tree);
87 static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree,
88 int);
89 static tree valid_compound_expr_initializer (tree, tree);
90 static void push_string (const char *);
91 static void push_member_name (tree);
92 static int spelling_length (void);
93 static char *print_spelling (char *);
94 static void warning_init (const char *);
95 static tree digest_init (tree, tree, bool, int);
96 static void output_init_element (tree, bool, tree, tree, int);
97 static void output_pending_init_elements (int);
98 static int set_designator (int);
99 static void push_range_stack (tree);
100 static void add_pending_init (tree, tree);
101 static void set_nonincremental_init (void);
102 static void set_nonincremental_init_from_string (tree);
103 static tree find_init_member (tree);
104 static void readonly_error (tree, enum lvalue_use);
105 static int lvalue_or_else (tree, enum lvalue_use);
106 static int lvalue_p (tree);
107 static void record_maybe_used_decl (tree);
108 static int comptypes_internal (tree, tree);
109 \f
110 /* Return true if EXP is a null pointer constant, false otherwise. */
111
112 static bool
113 null_pointer_constant_p (tree expr)
114 {
115 /* This should really operate on c_expr structures, but they aren't
116 yet available everywhere required. */
117 tree type = TREE_TYPE (expr);
118 return (TREE_CODE (expr) == INTEGER_CST
119 && !TREE_OVERFLOW (expr)
120 && integer_zerop (expr)
121 && (INTEGRAL_TYPE_P (type)
122 || (TREE_CODE (type) == POINTER_TYPE
123 && VOID_TYPE_P (TREE_TYPE (type))
124 && TYPE_QUALS (TREE_TYPE (type)) == TYPE_UNQUALIFIED)));
125 }
126 \f/* This is a cache to hold if two types are compatible or not. */
127
128 struct tagged_tu_seen_cache {
129 const struct tagged_tu_seen_cache * next;
130 tree t1;
131 tree t2;
132 /* The return value of tagged_types_tu_compatible_p if we had seen
133 these two types already. */
134 int val;
135 };
136
137 static const struct tagged_tu_seen_cache * tagged_tu_seen_base;
138 static void free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *);
139
140 /* Do `exp = require_complete_type (exp);' to make sure exp
141 does not have an incomplete type. (That includes void types.) */
142
143 tree
144 require_complete_type (tree value)
145 {
146 tree type = TREE_TYPE (value);
147
148 if (value == error_mark_node || type == error_mark_node)
149 return error_mark_node;
150
151 /* First, detect a valid value with a complete type. */
152 if (COMPLETE_TYPE_P (type))
153 return value;
154
155 c_incomplete_type_error (value, type);
156 return error_mark_node;
157 }
158
159 /* Print an error message for invalid use of an incomplete type.
160 VALUE is the expression that was used (or 0 if that isn't known)
161 and TYPE is the type that was invalid. */
162
163 void
164 c_incomplete_type_error (tree value, tree type)
165 {
166 const char *type_code_string;
167
168 /* Avoid duplicate error message. */
169 if (TREE_CODE (type) == ERROR_MARK)
170 return;
171
172 if (value != 0 && (TREE_CODE (value) == VAR_DECL
173 || TREE_CODE (value) == PARM_DECL))
174 error ("%qD has an incomplete type", value);
175 else
176 {
177 retry:
178 /* We must print an error message. Be clever about what it says. */
179
180 switch (TREE_CODE (type))
181 {
182 case RECORD_TYPE:
183 type_code_string = "struct";
184 break;
185
186 case UNION_TYPE:
187 type_code_string = "union";
188 break;
189
190 case ENUMERAL_TYPE:
191 type_code_string = "enum";
192 break;
193
194 case VOID_TYPE:
195 error ("invalid use of void expression");
196 return;
197
198 case ARRAY_TYPE:
199 if (TYPE_DOMAIN (type))
200 {
201 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
202 {
203 error ("invalid use of flexible array member");
204 return;
205 }
206 type = TREE_TYPE (type);
207 goto retry;
208 }
209 error ("invalid use of array with unspecified bounds");
210 return;
211
212 default:
213 gcc_unreachable ();
214 }
215
216 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
217 error ("invalid use of undefined type %<%s %E%>",
218 type_code_string, TYPE_NAME (type));
219 else
220 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
221 error ("invalid use of incomplete typedef %qD", TYPE_NAME (type));
222 }
223 }
224
225 /* Given a type, apply default promotions wrt unnamed function
226 arguments and return the new type. */
227
228 tree
229 c_type_promotes_to (tree type)
230 {
231 if (TYPE_MAIN_VARIANT (type) == float_type_node)
232 return double_type_node;
233
234 if (c_promoting_integer_type_p (type))
235 {
236 /* Preserve unsignedness if not really getting any wider. */
237 if (TYPE_UNSIGNED (type)
238 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
239 return unsigned_type_node;
240 return integer_type_node;
241 }
242
243 return type;
244 }
245
246 /* Return a variant of TYPE which has all the type qualifiers of LIKE
247 as well as those of TYPE. */
248
249 static tree
250 qualify_type (tree type, tree like)
251 {
252 return c_build_qualified_type (type,
253 TYPE_QUALS (type) | TYPE_QUALS (like));
254 }
255
256 /* Return true iff the given tree T is a variable length array. */
257
258 bool
259 c_vla_type_p (tree t)
260 {
261 if (TREE_CODE (t) == ARRAY_TYPE
262 && C_TYPE_VARIABLE_SIZE (t))
263 return true;
264 return false;
265 }
266 \f
267 /* Return the composite type of two compatible types.
268
269 We assume that comptypes has already been done and returned
270 nonzero; if that isn't so, this may crash. In particular, we
271 assume that qualifiers match. */
272
273 tree
274 composite_type (tree t1, tree t2)
275 {
276 enum tree_code code1;
277 enum tree_code code2;
278 tree attributes;
279
280 /* Save time if the two types are the same. */
281
282 if (t1 == t2) return t1;
283
284 /* If one type is nonsense, use the other. */
285 if (t1 == error_mark_node)
286 return t2;
287 if (t2 == error_mark_node)
288 return t1;
289
290 code1 = TREE_CODE (t1);
291 code2 = TREE_CODE (t2);
292
293 /* Merge the attributes. */
294 attributes = targetm.merge_type_attributes (t1, t2);
295
296 /* If one is an enumerated type and the other is the compatible
297 integer type, the composite type might be either of the two
298 (DR#013 question 3). For consistency, use the enumerated type as
299 the composite type. */
300
301 if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE)
302 return t1;
303 if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE)
304 return t2;
305
306 gcc_assert (code1 == code2);
307
308 switch (code1)
309 {
310 case POINTER_TYPE:
311 /* For two pointers, do this recursively on the target type. */
312 {
313 tree pointed_to_1 = TREE_TYPE (t1);
314 tree pointed_to_2 = TREE_TYPE (t2);
315 tree target = composite_type (pointed_to_1, pointed_to_2);
316 t1 = build_pointer_type (target);
317 t1 = build_type_attribute_variant (t1, attributes);
318 return qualify_type (t1, t2);
319 }
320
321 case ARRAY_TYPE:
322 {
323 tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
324 int quals;
325 tree unqual_elt;
326 tree d1 = TYPE_DOMAIN (t1);
327 tree d2 = TYPE_DOMAIN (t2);
328 bool d1_variable, d2_variable;
329 bool d1_zero, d2_zero;
330
331 /* We should not have any type quals on arrays at all. */
332 gcc_assert (!TYPE_QUALS (t1) && !TYPE_QUALS (t2));
333
334 d1_zero = d1 == 0 || !TYPE_MAX_VALUE (d1);
335 d2_zero = d2 == 0 || !TYPE_MAX_VALUE (d2);
336
337 d1_variable = (!d1_zero
338 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
339 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
340 d2_variable = (!d2_zero
341 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
342 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
343 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
344 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
345
346 /* Save space: see if the result is identical to one of the args. */
347 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)
348 && (d2_variable || d2_zero || !d1_variable))
349 return build_type_attribute_variant (t1, attributes);
350 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)
351 && (d1_variable || d1_zero || !d2_variable))
352 return build_type_attribute_variant (t2, attributes);
353
354 if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
355 return build_type_attribute_variant (t1, attributes);
356 if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1))
357 return build_type_attribute_variant (t2, attributes);
358
359 /* Merge the element types, and have a size if either arg has
360 one. We may have qualifiers on the element types. To set
361 up TYPE_MAIN_VARIANT correctly, we need to form the
362 composite of the unqualified types and add the qualifiers
363 back at the end. */
364 quals = TYPE_QUALS (strip_array_types (elt));
365 unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED);
366 t1 = build_array_type (unqual_elt,
367 TYPE_DOMAIN ((TYPE_DOMAIN (t1)
368 && (d2_variable
369 || d2_zero
370 || !d1_variable))
371 ? t1
372 : t2));
373 t1 = c_build_qualified_type (t1, quals);
374 return build_type_attribute_variant (t1, attributes);
375 }
376
377 case ENUMERAL_TYPE:
378 case RECORD_TYPE:
379 case UNION_TYPE:
380 if (attributes != NULL)
381 {
382 /* Try harder not to create a new aggregate type. */
383 if (attribute_list_equal (TYPE_ATTRIBUTES (t1), attributes))
384 return t1;
385 if (attribute_list_equal (TYPE_ATTRIBUTES (t2), attributes))
386 return t2;
387 }
388 return build_type_attribute_variant (t1, attributes);
389
390 case FUNCTION_TYPE:
391 /* Function types: prefer the one that specified arg types.
392 If both do, merge the arg types. Also merge the return types. */
393 {
394 tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2));
395 tree p1 = TYPE_ARG_TYPES (t1);
396 tree p2 = TYPE_ARG_TYPES (t2);
397 int len;
398 tree newargs, n;
399 int i;
400
401 /* Save space: see if the result is identical to one of the args. */
402 if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2))
403 return build_type_attribute_variant (t1, attributes);
404 if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1))
405 return build_type_attribute_variant (t2, attributes);
406
407 /* Simple way if one arg fails to specify argument types. */
408 if (TYPE_ARG_TYPES (t1) == 0)
409 {
410 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
411 t1 = build_type_attribute_variant (t1, attributes);
412 return qualify_type (t1, t2);
413 }
414 if (TYPE_ARG_TYPES (t2) == 0)
415 {
416 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
417 t1 = build_type_attribute_variant (t1, attributes);
418 return qualify_type (t1, t2);
419 }
420
421 /* If both args specify argument types, we must merge the two
422 lists, argument by argument. */
423 /* Tell global_bindings_p to return false so that variable_size
424 doesn't die on VLAs in parameter types. */
425 c_override_global_bindings_to_false = true;
426
427 len = list_length (p1);
428 newargs = 0;
429
430 for (i = 0; i < len; i++)
431 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
432
433 n = newargs;
434
435 for (; p1;
436 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
437 {
438 /* A null type means arg type is not specified.
439 Take whatever the other function type has. */
440 if (TREE_VALUE (p1) == 0)
441 {
442 TREE_VALUE (n) = TREE_VALUE (p2);
443 goto parm_done;
444 }
445 if (TREE_VALUE (p2) == 0)
446 {
447 TREE_VALUE (n) = TREE_VALUE (p1);
448 goto parm_done;
449 }
450
451 /* Given wait (union {union wait *u; int *i} *)
452 and wait (union wait *),
453 prefer union wait * as type of parm. */
454 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
455 && TREE_VALUE (p1) != TREE_VALUE (p2))
456 {
457 tree memb;
458 tree mv2 = TREE_VALUE (p2);
459 if (mv2 && mv2 != error_mark_node
460 && TREE_CODE (mv2) != ARRAY_TYPE)
461 mv2 = TYPE_MAIN_VARIANT (mv2);
462 for (memb = TYPE_FIELDS (TREE_VALUE (p1));
463 memb; memb = TREE_CHAIN (memb))
464 {
465 tree mv3 = TREE_TYPE (memb);
466 if (mv3 && mv3 != error_mark_node
467 && TREE_CODE (mv3) != ARRAY_TYPE)
468 mv3 = TYPE_MAIN_VARIANT (mv3);
469 if (comptypes (mv3, mv2))
470 {
471 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
472 TREE_VALUE (p2));
473 if (pedantic)
474 pedwarn ("function types not truly compatible in ISO C");
475 goto parm_done;
476 }
477 }
478 }
479 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
480 && TREE_VALUE (p2) != TREE_VALUE (p1))
481 {
482 tree memb;
483 tree mv1 = TREE_VALUE (p1);
484 if (mv1 && mv1 != error_mark_node
485 && TREE_CODE (mv1) != ARRAY_TYPE)
486 mv1 = TYPE_MAIN_VARIANT (mv1);
487 for (memb = TYPE_FIELDS (TREE_VALUE (p2));
488 memb; memb = TREE_CHAIN (memb))
489 {
490 tree mv3 = TREE_TYPE (memb);
491 if (mv3 && mv3 != error_mark_node
492 && TREE_CODE (mv3) != ARRAY_TYPE)
493 mv3 = TYPE_MAIN_VARIANT (mv3);
494 if (comptypes (mv3, mv1))
495 {
496 TREE_VALUE (n) = composite_type (TREE_TYPE (memb),
497 TREE_VALUE (p1));
498 if (pedantic)
499 pedwarn ("function types not truly compatible in ISO C");
500 goto parm_done;
501 }
502 }
503 }
504 TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2));
505 parm_done: ;
506 }
507
508 c_override_global_bindings_to_false = false;
509 t1 = build_function_type (valtype, newargs);
510 t1 = qualify_type (t1, t2);
511 /* ... falls through ... */
512 }
513
514 default:
515 return build_type_attribute_variant (t1, attributes);
516 }
517
518 }
519
520 /* Return the type of a conditional expression between pointers to
521 possibly differently qualified versions of compatible types.
522
523 We assume that comp_target_types has already been done and returned
524 nonzero; if that isn't so, this may crash. */
525
526 static tree
527 common_pointer_type (tree t1, tree t2)
528 {
529 tree attributes;
530 tree pointed_to_1, mv1;
531 tree pointed_to_2, mv2;
532 tree target;
533
534 /* Save time if the two types are the same. */
535
536 if (t1 == t2) return t1;
537
538 /* If one type is nonsense, use the other. */
539 if (t1 == error_mark_node)
540 return t2;
541 if (t2 == error_mark_node)
542 return t1;
543
544 gcc_assert (TREE_CODE (t1) == POINTER_TYPE
545 && TREE_CODE (t2) == POINTER_TYPE);
546
547 /* Merge the attributes. */
548 attributes = targetm.merge_type_attributes (t1, t2);
549
550 /* Find the composite type of the target types, and combine the
551 qualifiers of the two types' targets. Do not lose qualifiers on
552 array element types by taking the TYPE_MAIN_VARIANT. */
553 mv1 = pointed_to_1 = TREE_TYPE (t1);
554 mv2 = pointed_to_2 = TREE_TYPE (t2);
555 if (TREE_CODE (mv1) != ARRAY_TYPE)
556 mv1 = TYPE_MAIN_VARIANT (pointed_to_1);
557 if (TREE_CODE (mv2) != ARRAY_TYPE)
558 mv2 = TYPE_MAIN_VARIANT (pointed_to_2);
559 target = composite_type (mv1, mv2);
560 t1 = build_pointer_type (c_build_qualified_type
561 (target,
562 TYPE_QUALS (pointed_to_1) |
563 TYPE_QUALS (pointed_to_2)));
564 return build_type_attribute_variant (t1, attributes);
565 }
566
567 /* Return the common type for two arithmetic types under the usual
568 arithmetic conversions. The default conversions have already been
569 applied, and enumerated types converted to their compatible integer
570 types. The resulting type is unqualified and has no attributes.
571
572 This is the type for the result of most arithmetic operations
573 if the operands have the given two types. */
574
575 static tree
576 c_common_type (tree t1, tree t2)
577 {
578 enum tree_code code1;
579 enum tree_code code2;
580
581 /* If one type is nonsense, use the other. */
582 if (t1 == error_mark_node)
583 return t2;
584 if (t2 == error_mark_node)
585 return t1;
586
587 if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED)
588 t1 = TYPE_MAIN_VARIANT (t1);
589
590 if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED)
591 t2 = TYPE_MAIN_VARIANT (t2);
592
593 if (TYPE_ATTRIBUTES (t1) != NULL_TREE)
594 t1 = build_type_attribute_variant (t1, NULL_TREE);
595
596 if (TYPE_ATTRIBUTES (t2) != NULL_TREE)
597 t2 = build_type_attribute_variant (t2, NULL_TREE);
598
599 /* Save time if the two types are the same. */
600
601 if (t1 == t2) return t1;
602
603 code1 = TREE_CODE (t1);
604 code2 = TREE_CODE (t2);
605
606 gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE
607 || code1 == REAL_TYPE || code1 == INTEGER_TYPE);
608 gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE
609 || code2 == REAL_TYPE || code2 == INTEGER_TYPE);
610
611 /* When one operand is a decimal float type, the other operand cannot be
612 a generic float type or a complex type. We also disallow vector types
613 here. */
614 if ((DECIMAL_FLOAT_TYPE_P (t1) || DECIMAL_FLOAT_TYPE_P (t2))
615 && !(DECIMAL_FLOAT_TYPE_P (t1) && DECIMAL_FLOAT_TYPE_P (t2)))
616 {
617 if (code1 == VECTOR_TYPE || code2 == VECTOR_TYPE)
618 {
619 error ("can%'t mix operands of decimal float and vector types");
620 return error_mark_node;
621 }
622 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
623 {
624 error ("can%'t mix operands of decimal float and complex types");
625 return error_mark_node;
626 }
627 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
628 {
629 error ("can%'t mix operands of decimal float and other float types");
630 return error_mark_node;
631 }
632 }
633
634 /* If one type is a vector type, return that type. (How the usual
635 arithmetic conversions apply to the vector types extension is not
636 precisely specified.) */
637 if (code1 == VECTOR_TYPE)
638 return t1;
639
640 if (code2 == VECTOR_TYPE)
641 return t2;
642
643 /* If one type is complex, form the common type of the non-complex
644 components, then make that complex. Use T1 or T2 if it is the
645 required type. */
646 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
647 {
648 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
649 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
650 tree subtype = c_common_type (subtype1, subtype2);
651
652 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
653 return t1;
654 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
655 return t2;
656 else
657 return build_complex_type (subtype);
658 }
659
660 /* If only one is real, use it as the result. */
661
662 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
663 return t1;
664
665 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
666 return t2;
667
668 /* If both are real and either are decimal floating point types, use
669 the decimal floating point type with the greater precision. */
670
671 if (code1 == REAL_TYPE && code2 == REAL_TYPE)
672 {
673 if (TYPE_MAIN_VARIANT (t1) == dfloat128_type_node
674 || TYPE_MAIN_VARIANT (t2) == dfloat128_type_node)
675 return dfloat128_type_node;
676 else if (TYPE_MAIN_VARIANT (t1) == dfloat64_type_node
677 || TYPE_MAIN_VARIANT (t2) == dfloat64_type_node)
678 return dfloat64_type_node;
679 else if (TYPE_MAIN_VARIANT (t1) == dfloat32_type_node
680 || TYPE_MAIN_VARIANT (t2) == dfloat32_type_node)
681 return dfloat32_type_node;
682 }
683
684 /* Both real or both integers; use the one with greater precision. */
685
686 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
687 return t1;
688 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
689 return t2;
690
691 /* Same precision. Prefer long longs to longs to ints when the
692 same precision, following the C99 rules on integer type rank
693 (which are equivalent to the C90 rules for C90 types). */
694
695 if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node
696 || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node)
697 return long_long_unsigned_type_node;
698
699 if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node
700 || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node)
701 {
702 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
703 return long_long_unsigned_type_node;
704 else
705 return long_long_integer_type_node;
706 }
707
708 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
709 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
710 return long_unsigned_type_node;
711
712 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
713 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
714 {
715 /* But preserve unsignedness from the other type,
716 since long cannot hold all the values of an unsigned int. */
717 if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2))
718 return long_unsigned_type_node;
719 else
720 return long_integer_type_node;
721 }
722
723 /* Likewise, prefer long double to double even if same size. */
724 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
725 || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
726 return long_double_type_node;
727
728 /* Otherwise prefer the unsigned one. */
729
730 if (TYPE_UNSIGNED (t1))
731 return t1;
732 else
733 return t2;
734 }
735 \f
736 /* Wrapper around c_common_type that is used by c-common.c and other
737 front end optimizations that remove promotions. ENUMERAL_TYPEs
738 are allowed here and are converted to their compatible integer types.
739 BOOLEAN_TYPEs are allowed here and return either boolean_type_node or
740 preferably a non-Boolean type as the common type. */
741 tree
742 common_type (tree t1, tree t2)
743 {
744 if (TREE_CODE (t1) == ENUMERAL_TYPE)
745 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
746 if (TREE_CODE (t2) == ENUMERAL_TYPE)
747 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
748
749 /* If both types are BOOLEAN_TYPE, then return boolean_type_node. */
750 if (TREE_CODE (t1) == BOOLEAN_TYPE
751 && TREE_CODE (t2) == BOOLEAN_TYPE)
752 return boolean_type_node;
753
754 /* If either type is BOOLEAN_TYPE, then return the other. */
755 if (TREE_CODE (t1) == BOOLEAN_TYPE)
756 return t2;
757 if (TREE_CODE (t2) == BOOLEAN_TYPE)
758 return t1;
759
760 return c_common_type (t1, t2);
761 }
762
763 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
764 or various other operations. Return 2 if they are compatible
765 but a warning may be needed if you use them together. */
766
767 int
768 comptypes (tree type1, tree type2)
769 {
770 const struct tagged_tu_seen_cache * tagged_tu_seen_base1 = tagged_tu_seen_base;
771 int val;
772
773 val = comptypes_internal (type1, type2);
774 free_all_tagged_tu_seen_up_to (tagged_tu_seen_base1);
775
776 return val;
777 }
778 \f
779 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
780 or various other operations. Return 2 if they are compatible
781 but a warning may be needed if you use them together. This
782 differs from comptypes, in that we don't free the seen types. */
783
784 static int
785 comptypes_internal (tree type1, tree type2)
786 {
787 tree t1 = type1;
788 tree t2 = type2;
789 int attrval, val;
790
791 /* Suppress errors caused by previously reported errors. */
792
793 if (t1 == t2 || !t1 || !t2
794 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
795 return 1;
796
797 /* If either type is the internal version of sizetype, return the
798 language version. */
799 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
800 && TYPE_ORIG_SIZE_TYPE (t1))
801 t1 = TYPE_ORIG_SIZE_TYPE (t1);
802
803 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
804 && TYPE_ORIG_SIZE_TYPE (t2))
805 t2 = TYPE_ORIG_SIZE_TYPE (t2);
806
807
808 /* Enumerated types are compatible with integer types, but this is
809 not transitive: two enumerated types in the same translation unit
810 are compatible with each other only if they are the same type. */
811
812 if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE)
813 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1));
814 else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE)
815 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2));
816
817 if (t1 == t2)
818 return 1;
819
820 /* Different classes of types can't be compatible. */
821
822 if (TREE_CODE (t1) != TREE_CODE (t2))
823 return 0;
824
825 /* Qualifiers must match. C99 6.7.3p9 */
826
827 if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
828 return 0;
829
830 /* Allow for two different type nodes which have essentially the same
831 definition. Note that we already checked for equality of the type
832 qualifiers (just above). */
833
834 if (TREE_CODE (t1) != ARRAY_TYPE
835 && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
836 return 1;
837
838 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
839 if (!(attrval = targetm.comp_type_attributes (t1, t2)))
840 return 0;
841
842 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
843 val = 0;
844
845 switch (TREE_CODE (t1))
846 {
847 case POINTER_TYPE:
848 /* Do not remove mode or aliasing information. */
849 if (TYPE_MODE (t1) != TYPE_MODE (t2)
850 || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2))
851 break;
852 val = (TREE_TYPE (t1) == TREE_TYPE (t2)
853 ? 1 : comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2)));
854 break;
855
856 case FUNCTION_TYPE:
857 val = function_types_compatible_p (t1, t2);
858 break;
859
860 case ARRAY_TYPE:
861 {
862 tree d1 = TYPE_DOMAIN (t1);
863 tree d2 = TYPE_DOMAIN (t2);
864 bool d1_variable, d2_variable;
865 bool d1_zero, d2_zero;
866 val = 1;
867
868 /* Target types must match incl. qualifiers. */
869 if (TREE_TYPE (t1) != TREE_TYPE (t2)
870 && 0 == (val = comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2))))
871 return 0;
872
873 /* Sizes must match unless one is missing or variable. */
874 if (d1 == 0 || d2 == 0 || d1 == d2)
875 break;
876
877 d1_zero = !TYPE_MAX_VALUE (d1);
878 d2_zero = !TYPE_MAX_VALUE (d2);
879
880 d1_variable = (!d1_zero
881 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
882 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
883 d2_variable = (!d2_zero
884 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
885 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
886 d1_variable = d1_variable || (d1_zero && c_vla_type_p (t1));
887 d2_variable = d2_variable || (d2_zero && c_vla_type_p (t2));
888
889 if (d1_variable || d2_variable)
890 break;
891 if (d1_zero && d2_zero)
892 break;
893 if (d1_zero || d2_zero
894 || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
895 || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
896 val = 0;
897
898 break;
899 }
900
901 case ENUMERAL_TYPE:
902 case RECORD_TYPE:
903 case UNION_TYPE:
904 if (val != 1 && !same_translation_unit_p (t1, t2))
905 {
906 tree a1 = TYPE_ATTRIBUTES (t1);
907 tree a2 = TYPE_ATTRIBUTES (t2);
908
909 if (! attribute_list_contained (a1, a2)
910 && ! attribute_list_contained (a2, a1))
911 break;
912
913 if (attrval != 2)
914 return tagged_types_tu_compatible_p (t1, t2);
915 val = tagged_types_tu_compatible_p (t1, t2);
916 }
917 break;
918
919 case VECTOR_TYPE:
920 val = TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2)
921 && comptypes_internal (TREE_TYPE (t1), TREE_TYPE (t2));
922 break;
923
924 default:
925 break;
926 }
927 return attrval == 2 && val == 1 ? 2 : val;
928 }
929
930 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
931 ignoring their qualifiers. */
932
933 static int
934 comp_target_types (tree ttl, tree ttr)
935 {
936 int val;
937 tree mvl, mvr;
938
939 /* Do not lose qualifiers on element types of array types that are
940 pointer targets by taking their TYPE_MAIN_VARIANT. */
941 mvl = TREE_TYPE (ttl);
942 mvr = TREE_TYPE (ttr);
943 if (TREE_CODE (mvl) != ARRAY_TYPE)
944 mvl = TYPE_MAIN_VARIANT (mvl);
945 if (TREE_CODE (mvr) != ARRAY_TYPE)
946 mvr = TYPE_MAIN_VARIANT (mvr);
947 val = comptypes (mvl, mvr);
948
949 if (val == 2 && pedantic)
950 pedwarn ("types are not quite compatible");
951 return val;
952 }
953 \f
954 /* Subroutines of `comptypes'. */
955
956 /* Determine whether two trees derive from the same translation unit.
957 If the CONTEXT chain ends in a null, that tree's context is still
958 being parsed, so if two trees have context chains ending in null,
959 they're in the same translation unit. */
960 int
961 same_translation_unit_p (tree t1, tree t2)
962 {
963 while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL)
964 switch (TREE_CODE_CLASS (TREE_CODE (t1)))
965 {
966 case tcc_declaration:
967 t1 = DECL_CONTEXT (t1); break;
968 case tcc_type:
969 t1 = TYPE_CONTEXT (t1); break;
970 case tcc_exceptional:
971 t1 = BLOCK_SUPERCONTEXT (t1); break; /* assume block */
972 default: gcc_unreachable ();
973 }
974
975 while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL)
976 switch (TREE_CODE_CLASS (TREE_CODE (t2)))
977 {
978 case tcc_declaration:
979 t2 = DECL_CONTEXT (t2); break;
980 case tcc_type:
981 t2 = TYPE_CONTEXT (t2); break;
982 case tcc_exceptional:
983 t2 = BLOCK_SUPERCONTEXT (t2); break; /* assume block */
984 default: gcc_unreachable ();
985 }
986
987 return t1 == t2;
988 }
989
990 /* Allocate the seen two types, assuming that they are compatible. */
991
992 static struct tagged_tu_seen_cache *
993 alloc_tagged_tu_seen_cache (tree t1, tree t2)
994 {
995 struct tagged_tu_seen_cache *tu = XNEW (struct tagged_tu_seen_cache);
996 tu->next = tagged_tu_seen_base;
997 tu->t1 = t1;
998 tu->t2 = t2;
999
1000 tagged_tu_seen_base = tu;
1001
1002 /* The C standard says that two structures in different translation
1003 units are compatible with each other only if the types of their
1004 fields are compatible (among other things). We assume that they
1005 are compatible until proven otherwise when building the cache.
1006 An example where this can occur is:
1007 struct a
1008 {
1009 struct a *next;
1010 };
1011 If we are comparing this against a similar struct in another TU,
1012 and did not assume they were compatible, we end up with an infinite
1013 loop. */
1014 tu->val = 1;
1015 return tu;
1016 }
1017
1018 /* Free the seen types until we get to TU_TIL. */
1019
1020 static void
1021 free_all_tagged_tu_seen_up_to (const struct tagged_tu_seen_cache *tu_til)
1022 {
1023 const struct tagged_tu_seen_cache *tu = tagged_tu_seen_base;
1024 while (tu != tu_til)
1025 {
1026 const struct tagged_tu_seen_cache *const tu1
1027 = (const struct tagged_tu_seen_cache *) tu;
1028 tu = tu1->next;
1029 free (CONST_CAST (tu1));
1030 }
1031 tagged_tu_seen_base = tu_til;
1032 }
1033
1034 /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
1035 compatible. If the two types are not the same (which has been
1036 checked earlier), this can only happen when multiple translation
1037 units are being compiled. See C99 6.2.7 paragraph 1 for the exact
1038 rules. */
1039
1040 static int
1041 tagged_types_tu_compatible_p (tree t1, tree t2)
1042 {
1043 tree s1, s2;
1044 bool needs_warning = false;
1045
1046 /* We have to verify that the tags of the types are the same. This
1047 is harder than it looks because this may be a typedef, so we have
1048 to go look at the original type. It may even be a typedef of a
1049 typedef...
1050 In the case of compiler-created builtin structs the TYPE_DECL
1051 may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
1052 while (TYPE_NAME (t1)
1053 && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL
1054 && DECL_ORIGINAL_TYPE (TYPE_NAME (t1)))
1055 t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1));
1056
1057 while (TYPE_NAME (t2)
1058 && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL
1059 && DECL_ORIGINAL_TYPE (TYPE_NAME (t2)))
1060 t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2));
1061
1062 /* C90 didn't have the requirement that the two tags be the same. */
1063 if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2))
1064 return 0;
1065
1066 /* C90 didn't say what happened if one or both of the types were
1067 incomplete; we choose to follow C99 rules here, which is that they
1068 are compatible. */
1069 if (TYPE_SIZE (t1) == NULL
1070 || TYPE_SIZE (t2) == NULL)
1071 return 1;
1072
1073 {
1074 const struct tagged_tu_seen_cache * tts_i;
1075 for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next)
1076 if (tts_i->t1 == t1 && tts_i->t2 == t2)
1077 return tts_i->val;
1078 }
1079
1080 switch (TREE_CODE (t1))
1081 {
1082 case ENUMERAL_TYPE:
1083 {
1084 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1085 /* Speed up the case where the type values are in the same order. */
1086 tree tv1 = TYPE_VALUES (t1);
1087 tree tv2 = TYPE_VALUES (t2);
1088
1089 if (tv1 == tv2)
1090 {
1091 return 1;
1092 }
1093
1094 for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2))
1095 {
1096 if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2))
1097 break;
1098 if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1)
1099 {
1100 tu->val = 0;
1101 return 0;
1102 }
1103 }
1104
1105 if (tv1 == NULL_TREE && tv2 == NULL_TREE)
1106 {
1107 return 1;
1108 }
1109 if (tv1 == NULL_TREE || tv2 == NULL_TREE)
1110 {
1111 tu->val = 0;
1112 return 0;
1113 }
1114
1115 if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2)))
1116 {
1117 tu->val = 0;
1118 return 0;
1119 }
1120
1121 for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1))
1122 {
1123 s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2));
1124 if (s2 == NULL
1125 || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1)
1126 {
1127 tu->val = 0;
1128 return 0;
1129 }
1130 }
1131 return 1;
1132 }
1133
1134 case UNION_TYPE:
1135 {
1136 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1137 if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2)))
1138 {
1139 tu->val = 0;
1140 return 0;
1141 }
1142
1143 /* Speed up the common case where the fields are in the same order. */
1144 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2;
1145 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1146 {
1147 int result;
1148
1149
1150 if (DECL_NAME (s1) == NULL
1151 || DECL_NAME (s1) != DECL_NAME (s2))
1152 break;
1153 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1154 if (result == 0)
1155 {
1156 tu->val = 0;
1157 return 0;
1158 }
1159 if (result == 2)
1160 needs_warning = true;
1161
1162 if (TREE_CODE (s1) == FIELD_DECL
1163 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1164 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1165 {
1166 tu->val = 0;
1167 return 0;
1168 }
1169 }
1170 if (!s1 && !s2)
1171 {
1172 tu->val = needs_warning ? 2 : 1;
1173 return tu->val;
1174 }
1175
1176 for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1))
1177 {
1178 bool ok = false;
1179
1180 if (DECL_NAME (s1) != NULL)
1181 for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2))
1182 if (DECL_NAME (s1) == DECL_NAME (s2))
1183 {
1184 int result;
1185 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1186 if (result == 0)
1187 {
1188 tu->val = 0;
1189 return 0;
1190 }
1191 if (result == 2)
1192 needs_warning = true;
1193
1194 if (TREE_CODE (s1) == FIELD_DECL
1195 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1196 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1197 break;
1198
1199 ok = true;
1200 break;
1201 }
1202 if (!ok)
1203 {
1204 tu->val = 0;
1205 return 0;
1206 }
1207 }
1208 tu->val = needs_warning ? 2 : 10;
1209 return tu->val;
1210 }
1211
1212 case RECORD_TYPE:
1213 {
1214 struct tagged_tu_seen_cache *tu = alloc_tagged_tu_seen_cache (t1, t2);
1215
1216 for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2);
1217 s1 && s2;
1218 s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
1219 {
1220 int result;
1221 if (TREE_CODE (s1) != TREE_CODE (s2)
1222 || DECL_NAME (s1) != DECL_NAME (s2))
1223 break;
1224 result = comptypes_internal (TREE_TYPE (s1), TREE_TYPE (s2));
1225 if (result == 0)
1226 break;
1227 if (result == 2)
1228 needs_warning = true;
1229
1230 if (TREE_CODE (s1) == FIELD_DECL
1231 && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
1232 DECL_FIELD_BIT_OFFSET (s2)) != 1)
1233 break;
1234 }
1235 if (s1 && s2)
1236 tu->val = 0;
1237 else
1238 tu->val = needs_warning ? 2 : 1;
1239 return tu->val;
1240 }
1241
1242 default:
1243 gcc_unreachable ();
1244 }
1245 }
1246
1247 /* Return 1 if two function types F1 and F2 are compatible.
1248 If either type specifies no argument types,
1249 the other must specify a fixed number of self-promoting arg types.
1250 Otherwise, if one type specifies only the number of arguments,
1251 the other must specify that number of self-promoting arg types.
1252 Otherwise, the argument types must match. */
1253
1254 static int
1255 function_types_compatible_p (tree f1, tree f2)
1256 {
1257 tree args1, args2;
1258 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1259 int val = 1;
1260 int val1;
1261 tree ret1, ret2;
1262
1263 ret1 = TREE_TYPE (f1);
1264 ret2 = TREE_TYPE (f2);
1265
1266 /* 'volatile' qualifiers on a function's return type used to mean
1267 the function is noreturn. */
1268 if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2))
1269 pedwarn ("function return types not compatible due to %<volatile%>");
1270 if (TYPE_VOLATILE (ret1))
1271 ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1),
1272 TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE);
1273 if (TYPE_VOLATILE (ret2))
1274 ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2),
1275 TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE);
1276 val = comptypes_internal (ret1, ret2);
1277 if (val == 0)
1278 return 0;
1279
1280 args1 = TYPE_ARG_TYPES (f1);
1281 args2 = TYPE_ARG_TYPES (f2);
1282
1283 /* An unspecified parmlist matches any specified parmlist
1284 whose argument types don't need default promotions. */
1285
1286 if (args1 == 0)
1287 {
1288 if (!self_promoting_args_p (args2))
1289 return 0;
1290 /* If one of these types comes from a non-prototype fn definition,
1291 compare that with the other type's arglist.
1292 If they don't match, ask for a warning (but no error). */
1293 if (TYPE_ACTUAL_ARG_TYPES (f1)
1294 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
1295 val = 2;
1296 return val;
1297 }
1298 if (args2 == 0)
1299 {
1300 if (!self_promoting_args_p (args1))
1301 return 0;
1302 if (TYPE_ACTUAL_ARG_TYPES (f2)
1303 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
1304 val = 2;
1305 return val;
1306 }
1307
1308 /* Both types have argument lists: compare them and propagate results. */
1309 val1 = type_lists_compatible_p (args1, args2);
1310 return val1 != 1 ? val1 : val;
1311 }
1312
1313 /* Check two lists of types for compatibility,
1314 returning 0 for incompatible, 1 for compatible,
1315 or 2 for compatible with warning. */
1316
1317 static int
1318 type_lists_compatible_p (tree args1, tree args2)
1319 {
1320 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
1321 int val = 1;
1322 int newval = 0;
1323
1324 while (1)
1325 {
1326 tree a1, mv1, a2, mv2;
1327 if (args1 == 0 && args2 == 0)
1328 return val;
1329 /* If one list is shorter than the other,
1330 they fail to match. */
1331 if (args1 == 0 || args2 == 0)
1332 return 0;
1333 mv1 = a1 = TREE_VALUE (args1);
1334 mv2 = a2 = TREE_VALUE (args2);
1335 if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE)
1336 mv1 = TYPE_MAIN_VARIANT (mv1);
1337 if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE)
1338 mv2 = TYPE_MAIN_VARIANT (mv2);
1339 /* A null pointer instead of a type
1340 means there is supposed to be an argument
1341 but nothing is specified about what type it has.
1342 So match anything that self-promotes. */
1343 if (a1 == 0)
1344 {
1345 if (c_type_promotes_to (a2) != a2)
1346 return 0;
1347 }
1348 else if (a2 == 0)
1349 {
1350 if (c_type_promotes_to (a1) != a1)
1351 return 0;
1352 }
1353 /* If one of the lists has an error marker, ignore this arg. */
1354 else if (TREE_CODE (a1) == ERROR_MARK
1355 || TREE_CODE (a2) == ERROR_MARK)
1356 ;
1357 else if (!(newval = comptypes_internal (mv1, mv2)))
1358 {
1359 /* Allow wait (union {union wait *u; int *i} *)
1360 and wait (union wait *) to be compatible. */
1361 if (TREE_CODE (a1) == UNION_TYPE
1362 && (TYPE_NAME (a1) == 0
1363 || TYPE_TRANSPARENT_UNION (a1))
1364 && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST
1365 && tree_int_cst_equal (TYPE_SIZE (a1),
1366 TYPE_SIZE (a2)))
1367 {
1368 tree memb;
1369 for (memb = TYPE_FIELDS (a1);
1370 memb; memb = TREE_CHAIN (memb))
1371 {
1372 tree mv3 = TREE_TYPE (memb);
1373 if (mv3 && mv3 != error_mark_node
1374 && TREE_CODE (mv3) != ARRAY_TYPE)
1375 mv3 = TYPE_MAIN_VARIANT (mv3);
1376 if (comptypes_internal (mv3, mv2))
1377 break;
1378 }
1379 if (memb == 0)
1380 return 0;
1381 }
1382 else if (TREE_CODE (a2) == UNION_TYPE
1383 && (TYPE_NAME (a2) == 0
1384 || TYPE_TRANSPARENT_UNION (a2))
1385 && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST
1386 && tree_int_cst_equal (TYPE_SIZE (a2),
1387 TYPE_SIZE (a1)))
1388 {
1389 tree memb;
1390 for (memb = TYPE_FIELDS (a2);
1391 memb; memb = TREE_CHAIN (memb))
1392 {
1393 tree mv3 = TREE_TYPE (memb);
1394 if (mv3 && mv3 != error_mark_node
1395 && TREE_CODE (mv3) != ARRAY_TYPE)
1396 mv3 = TYPE_MAIN_VARIANT (mv3);
1397 if (comptypes_internal (mv3, mv1))
1398 break;
1399 }
1400 if (memb == 0)
1401 return 0;
1402 }
1403 else
1404 return 0;
1405 }
1406
1407 /* comptypes said ok, but record if it said to warn. */
1408 if (newval > val)
1409 val = newval;
1410
1411 args1 = TREE_CHAIN (args1);
1412 args2 = TREE_CHAIN (args2);
1413 }
1414 }
1415 \f
1416 /* Compute the size to increment a pointer by. */
1417
1418 static tree
1419 c_size_in_bytes (tree type)
1420 {
1421 enum tree_code code = TREE_CODE (type);
1422
1423 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
1424 return size_one_node;
1425
1426 if (!COMPLETE_OR_VOID_TYPE_P (type))
1427 {
1428 error ("arithmetic on pointer to an incomplete type");
1429 return size_one_node;
1430 }
1431
1432 /* Convert in case a char is more than one unit. */
1433 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
1434 size_int (TYPE_PRECISION (char_type_node)
1435 / BITS_PER_UNIT));
1436 }
1437 \f
1438 /* Return either DECL or its known constant value (if it has one). */
1439
1440 tree
1441 decl_constant_value (tree decl)
1442 {
1443 if (/* Don't change a variable array bound or initial value to a constant
1444 in a place where a variable is invalid. Note that DECL_INITIAL
1445 isn't valid for a PARM_DECL. */
1446 current_function_decl != 0
1447 && TREE_CODE (decl) != PARM_DECL
1448 && !TREE_THIS_VOLATILE (decl)
1449 && TREE_READONLY (decl)
1450 && DECL_INITIAL (decl) != 0
1451 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
1452 /* This is invalid if initial value is not constant.
1453 If it has either a function call, a memory reference,
1454 or a variable, then re-evaluating it could give different results. */
1455 && TREE_CONSTANT (DECL_INITIAL (decl))
1456 /* Check for cases where this is sub-optimal, even though valid. */
1457 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
1458 return DECL_INITIAL (decl);
1459 return decl;
1460 }
1461
1462 /* Return either DECL or its known constant value (if it has one), but
1463 return DECL if pedantic or DECL has mode BLKmode. This is for
1464 bug-compatibility with the old behavior of decl_constant_value
1465 (before GCC 3.0); every use of this function is a bug and it should
1466 be removed before GCC 3.1. It is not appropriate to use pedantic
1467 in a way that affects optimization, and BLKmode is probably not the
1468 right test for avoiding misoptimizations either. */
1469
1470 static tree
1471 decl_constant_value_for_broken_optimization (tree decl)
1472 {
1473 tree ret;
1474
1475 if (pedantic || DECL_MODE (decl) == BLKmode)
1476 return decl;
1477
1478 ret = decl_constant_value (decl);
1479 /* Avoid unwanted tree sharing between the initializer and current
1480 function's body where the tree can be modified e.g. by the
1481 gimplifier. */
1482 if (ret != decl && TREE_STATIC (decl))
1483 ret = unshare_expr (ret);
1484 return ret;
1485 }
1486
1487 /* Convert the array expression EXP to a pointer. */
1488 static tree
1489 array_to_pointer_conversion (tree exp)
1490 {
1491 tree orig_exp = exp;
1492 tree type = TREE_TYPE (exp);
1493 tree adr;
1494 tree restype = TREE_TYPE (type);
1495 tree ptrtype;
1496
1497 gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
1498
1499 STRIP_TYPE_NOPS (exp);
1500
1501 if (TREE_NO_WARNING (orig_exp))
1502 TREE_NO_WARNING (exp) = 1;
1503
1504 ptrtype = build_pointer_type (restype);
1505
1506 if (TREE_CODE (exp) == INDIRECT_REF)
1507 return convert (ptrtype, TREE_OPERAND (exp, 0));
1508
1509 if (TREE_CODE (exp) == VAR_DECL)
1510 {
1511 /* We are making an ADDR_EXPR of ptrtype. This is a valid
1512 ADDR_EXPR because it's the best way of representing what
1513 happens in C when we take the address of an array and place
1514 it in a pointer to the element type. */
1515 adr = build1 (ADDR_EXPR, ptrtype, exp);
1516 if (!c_mark_addressable (exp))
1517 return error_mark_node;
1518 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
1519 return adr;
1520 }
1521
1522 /* This way is better for a COMPONENT_REF since it can
1523 simplify the offset for a component. */
1524 adr = build_unary_op (ADDR_EXPR, exp, 1);
1525 return convert (ptrtype, adr);
1526 }
1527
1528 /* Convert the function expression EXP to a pointer. */
1529 static tree
1530 function_to_pointer_conversion (tree exp)
1531 {
1532 tree orig_exp = exp;
1533
1534 gcc_assert (TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE);
1535
1536 STRIP_TYPE_NOPS (exp);
1537
1538 if (TREE_NO_WARNING (orig_exp))
1539 TREE_NO_WARNING (exp) = 1;
1540
1541 return build_unary_op (ADDR_EXPR, exp, 0);
1542 }
1543
1544 /* Perform the default conversion of arrays and functions to pointers.
1545 Return the result of converting EXP. For any other expression, just
1546 return EXP after removing NOPs. */
1547
1548 struct c_expr
1549 default_function_array_conversion (struct c_expr exp)
1550 {
1551 tree orig_exp = exp.value;
1552 tree type = TREE_TYPE (exp.value);
1553 enum tree_code code = TREE_CODE (type);
1554
1555 switch (code)
1556 {
1557 case ARRAY_TYPE:
1558 {
1559 bool not_lvalue = false;
1560 bool lvalue_array_p;
1561
1562 while ((TREE_CODE (exp.value) == NON_LVALUE_EXPR
1563 || TREE_CODE (exp.value) == NOP_EXPR
1564 || TREE_CODE (exp.value) == CONVERT_EXPR)
1565 && TREE_TYPE (TREE_OPERAND (exp.value, 0)) == type)
1566 {
1567 if (TREE_CODE (exp.value) == NON_LVALUE_EXPR)
1568 not_lvalue = true;
1569 exp.value = TREE_OPERAND (exp.value, 0);
1570 }
1571
1572 if (TREE_NO_WARNING (orig_exp))
1573 TREE_NO_WARNING (exp.value) = 1;
1574
1575 lvalue_array_p = !not_lvalue && lvalue_p (exp.value);
1576 if (!flag_isoc99 && !lvalue_array_p)
1577 {
1578 /* Before C99, non-lvalue arrays do not decay to pointers.
1579 Normally, using such an array would be invalid; but it can
1580 be used correctly inside sizeof or as a statement expression.
1581 Thus, do not give an error here; an error will result later. */
1582 return exp;
1583 }
1584
1585 exp.value = array_to_pointer_conversion (exp.value);
1586 }
1587 break;
1588 case FUNCTION_TYPE:
1589 exp.value = function_to_pointer_conversion (exp.value);
1590 break;
1591 default:
1592 STRIP_TYPE_NOPS (exp.value);
1593 if (TREE_NO_WARNING (orig_exp))
1594 TREE_NO_WARNING (exp.value) = 1;
1595 break;
1596 }
1597
1598 return exp;
1599 }
1600
1601
1602 /* EXP is an expression of integer type. Apply the integer promotions
1603 to it and return the promoted value. */
1604
1605 tree
1606 perform_integral_promotions (tree exp)
1607 {
1608 tree type = TREE_TYPE (exp);
1609 enum tree_code code = TREE_CODE (type);
1610
1611 gcc_assert (INTEGRAL_TYPE_P (type));
1612
1613 /* Normally convert enums to int,
1614 but convert wide enums to something wider. */
1615 if (code == ENUMERAL_TYPE)
1616 {
1617 type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
1618 TYPE_PRECISION (integer_type_node)),
1619 ((TYPE_PRECISION (type)
1620 >= TYPE_PRECISION (integer_type_node))
1621 && TYPE_UNSIGNED (type)));
1622
1623 return convert (type, exp);
1624 }
1625
1626 /* ??? This should no longer be needed now bit-fields have their
1627 proper types. */
1628 if (TREE_CODE (exp) == COMPONENT_REF
1629 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
1630 /* If it's thinner than an int, promote it like a
1631 c_promoting_integer_type_p, otherwise leave it alone. */
1632 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
1633 TYPE_PRECISION (integer_type_node)))
1634 return convert (integer_type_node, exp);
1635
1636 if (c_promoting_integer_type_p (type))
1637 {
1638 /* Preserve unsignedness if not really getting any wider. */
1639 if (TYPE_UNSIGNED (type)
1640 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
1641 return convert (unsigned_type_node, exp);
1642
1643 return convert (integer_type_node, exp);
1644 }
1645
1646 return exp;
1647 }
1648
1649
1650 /* Perform default promotions for C data used in expressions.
1651 Enumeral types or short or char are converted to int.
1652 In addition, manifest constants symbols are replaced by their values. */
1653
1654 tree
1655 default_conversion (tree exp)
1656 {
1657 tree orig_exp;
1658 tree type = TREE_TYPE (exp);
1659 enum tree_code code = TREE_CODE (type);
1660
1661 /* Functions and arrays have been converted during parsing. */
1662 gcc_assert (code != FUNCTION_TYPE);
1663 if (code == ARRAY_TYPE)
1664 return exp;
1665
1666 /* Constants can be used directly unless they're not loadable. */
1667 if (TREE_CODE (exp) == CONST_DECL)
1668 exp = DECL_INITIAL (exp);
1669
1670 /* Replace a nonvolatile const static variable with its value unless
1671 it is an array, in which case we must be sure that taking the
1672 address of the array produces consistent results. */
1673 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE)
1674 {
1675 exp = decl_constant_value_for_broken_optimization (exp);
1676 type = TREE_TYPE (exp);
1677 }
1678
1679 /* Strip no-op conversions. */
1680 orig_exp = exp;
1681 STRIP_TYPE_NOPS (exp);
1682
1683 if (TREE_NO_WARNING (orig_exp))
1684 TREE_NO_WARNING (exp) = 1;
1685
1686 if (INTEGRAL_TYPE_P (type))
1687 return perform_integral_promotions (exp);
1688
1689 if (code == VOID_TYPE)
1690 {
1691 error ("void value not ignored as it ought to be");
1692 return error_mark_node;
1693 }
1694 return exp;
1695 }
1696 \f
1697 /* Look up COMPONENT in a structure or union DECL.
1698
1699 If the component name is not found, returns NULL_TREE. Otherwise,
1700 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1701 stepping down the chain to the component, which is in the last
1702 TREE_VALUE of the list. Normally the list is of length one, but if
1703 the component is embedded within (nested) anonymous structures or
1704 unions, the list steps down the chain to the component. */
1705
1706 static tree
1707 lookup_field (tree decl, tree component)
1708 {
1709 tree type = TREE_TYPE (decl);
1710 tree field;
1711
1712 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1713 to the field elements. Use a binary search on this array to quickly
1714 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1715 will always be set for structures which have many elements. */
1716
1717 if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s)
1718 {
1719 int bot, top, half;
1720 tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0];
1721
1722 field = TYPE_FIELDS (type);
1723 bot = 0;
1724 top = TYPE_LANG_SPECIFIC (type)->s->len;
1725 while (top - bot > 1)
1726 {
1727 half = (top - bot + 1) >> 1;
1728 field = field_array[bot+half];
1729
1730 if (DECL_NAME (field) == NULL_TREE)
1731 {
1732 /* Step through all anon unions in linear fashion. */
1733 while (DECL_NAME (field_array[bot]) == NULL_TREE)
1734 {
1735 field = field_array[bot++];
1736 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1737 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1738 {
1739 tree anon = lookup_field (field, component);
1740
1741 if (anon)
1742 return tree_cons (NULL_TREE, field, anon);
1743 }
1744 }
1745
1746 /* Entire record is only anon unions. */
1747 if (bot > top)
1748 return NULL_TREE;
1749
1750 /* Restart the binary search, with new lower bound. */
1751 continue;
1752 }
1753
1754 if (DECL_NAME (field) == component)
1755 break;
1756 if (DECL_NAME (field) < component)
1757 bot += half;
1758 else
1759 top = bot + half;
1760 }
1761
1762 if (DECL_NAME (field_array[bot]) == component)
1763 field = field_array[bot];
1764 else if (DECL_NAME (field) != component)
1765 return NULL_TREE;
1766 }
1767 else
1768 {
1769 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1770 {
1771 if (DECL_NAME (field) == NULL_TREE
1772 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1773 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
1774 {
1775 tree anon = lookup_field (field, component);
1776
1777 if (anon)
1778 return tree_cons (NULL_TREE, field, anon);
1779 }
1780
1781 if (DECL_NAME (field) == component)
1782 break;
1783 }
1784
1785 if (field == NULL_TREE)
1786 return NULL_TREE;
1787 }
1788
1789 return tree_cons (NULL_TREE, field, NULL_TREE);
1790 }
1791
1792 /* Make an expression to refer to the COMPONENT field of
1793 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1794
1795 tree
1796 build_component_ref (tree datum, tree component)
1797 {
1798 tree type = TREE_TYPE (datum);
1799 enum tree_code code = TREE_CODE (type);
1800 tree field = NULL;
1801 tree ref;
1802
1803 if (!objc_is_public (datum, component))
1804 return error_mark_node;
1805
1806 /* See if there is a field or component with name COMPONENT. */
1807
1808 if (code == RECORD_TYPE || code == UNION_TYPE)
1809 {
1810 if (!COMPLETE_TYPE_P (type))
1811 {
1812 c_incomplete_type_error (NULL_TREE, type);
1813 return error_mark_node;
1814 }
1815
1816 field = lookup_field (datum, component);
1817
1818 if (!field)
1819 {
1820 error ("%qT has no member named %qE", type, component);
1821 return error_mark_node;
1822 }
1823
1824 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1825 This might be better solved in future the way the C++ front
1826 end does it - by giving the anonymous entities each a
1827 separate name and type, and then have build_component_ref
1828 recursively call itself. We can't do that here. */
1829 do
1830 {
1831 tree subdatum = TREE_VALUE (field);
1832 int quals;
1833 tree subtype;
1834
1835 if (TREE_TYPE (subdatum) == error_mark_node)
1836 return error_mark_node;
1837
1838 quals = TYPE_QUALS (strip_array_types (TREE_TYPE (subdatum)));
1839 quals |= TYPE_QUALS (TREE_TYPE (datum));
1840 subtype = c_build_qualified_type (TREE_TYPE (subdatum), quals);
1841
1842 ref = build3 (COMPONENT_REF, subtype, datum, subdatum,
1843 NULL_TREE);
1844 if (TREE_READONLY (datum) || TREE_READONLY (subdatum))
1845 TREE_READONLY (ref) = 1;
1846 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
1847 TREE_THIS_VOLATILE (ref) = 1;
1848
1849 if (TREE_DEPRECATED (subdatum))
1850 warn_deprecated_use (subdatum);
1851
1852 datum = ref;
1853
1854 field = TREE_CHAIN (field);
1855 }
1856 while (field);
1857
1858 return ref;
1859 }
1860 else if (code != ERROR_MARK)
1861 error ("request for member %qE in something not a structure or union",
1862 component);
1863
1864 return error_mark_node;
1865 }
1866 \f
1867 /* Given an expression PTR for a pointer, return an expression
1868 for the value pointed to.
1869 ERRORSTRING is the name of the operator to appear in error messages. */
1870
1871 tree
1872 build_indirect_ref (tree ptr, const char *errorstring)
1873 {
1874 tree pointer = default_conversion (ptr);
1875 tree type = TREE_TYPE (pointer);
1876
1877 if (TREE_CODE (type) == POINTER_TYPE)
1878 {
1879 if (TREE_CODE (pointer) == CONVERT_EXPR
1880 || TREE_CODE (pointer) == NOP_EXPR
1881 || TREE_CODE (pointer) == VIEW_CONVERT_EXPR)
1882 {
1883 /* If a warning is issued, mark it to avoid duplicates from
1884 the backend. This only needs to be done at
1885 warn_strict_aliasing > 2. */
1886 if (warn_strict_aliasing > 2)
1887 if (strict_aliasing_warning (TREE_TYPE (TREE_OPERAND (pointer, 0)),
1888 type, TREE_OPERAND (pointer, 0)))
1889 TREE_NO_WARNING (pointer) = 1;
1890 }
1891
1892 if (TREE_CODE (pointer) == ADDR_EXPR
1893 && (TREE_TYPE (TREE_OPERAND (pointer, 0))
1894 == TREE_TYPE (type)))
1895 return TREE_OPERAND (pointer, 0);
1896 else
1897 {
1898 tree t = TREE_TYPE (type);
1899 tree ref;
1900
1901 ref = build1 (INDIRECT_REF, t, pointer);
1902
1903 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
1904 {
1905 error ("dereferencing pointer to incomplete type");
1906 return error_mark_node;
1907 }
1908 if (VOID_TYPE_P (t) && skip_evaluation == 0)
1909 warning (0, "dereferencing %<void *%> pointer");
1910
1911 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1912 so that we get the proper error message if the result is used
1913 to assign to. Also, &* is supposed to be a no-op.
1914 And ANSI C seems to specify that the type of the result
1915 should be the const type. */
1916 /* A de-reference of a pointer to const is not a const. It is valid
1917 to change it via some other pointer. */
1918 TREE_READONLY (ref) = TYPE_READONLY (t);
1919 TREE_SIDE_EFFECTS (ref)
1920 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
1921 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
1922 return ref;
1923 }
1924 }
1925 else if (TREE_CODE (pointer) != ERROR_MARK)
1926 error ("invalid type argument of %qs (have %qT)", errorstring, type);
1927 return error_mark_node;
1928 }
1929
1930 /* This handles expressions of the form "a[i]", which denotes
1931 an array reference.
1932
1933 This is logically equivalent in C to *(a+i), but we may do it differently.
1934 If A is a variable or a member, we generate a primitive ARRAY_REF.
1935 This avoids forcing the array out of registers, and can work on
1936 arrays that are not lvalues (for example, members of structures returned
1937 by functions). */
1938
1939 tree
1940 build_array_ref (tree array, tree index)
1941 {
1942 bool swapped = false;
1943 if (TREE_TYPE (array) == error_mark_node
1944 || TREE_TYPE (index) == error_mark_node)
1945 return error_mark_node;
1946
1947 if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE
1948 && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE)
1949 {
1950 tree temp;
1951 if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE
1952 && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE)
1953 {
1954 error ("subscripted value is neither array nor pointer");
1955 return error_mark_node;
1956 }
1957 temp = array;
1958 array = index;
1959 index = temp;
1960 swapped = true;
1961 }
1962
1963 if (!INTEGRAL_TYPE_P (TREE_TYPE (index)))
1964 {
1965 error ("array subscript is not an integer");
1966 return error_mark_node;
1967 }
1968
1969 if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE)
1970 {
1971 error ("subscripted value is pointer to function");
1972 return error_mark_node;
1973 }
1974
1975 /* ??? Existing practice has been to warn only when the char
1976 index is syntactically the index, not for char[array]. */
1977 if (!swapped)
1978 warn_array_subscript_with_type_char (index);
1979
1980 /* Apply default promotions *after* noticing character types. */
1981 index = default_conversion (index);
1982
1983 gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE);
1984
1985 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE)
1986 {
1987 tree rval, type;
1988
1989 /* An array that is indexed by a non-constant
1990 cannot be stored in a register; we must be able to do
1991 address arithmetic on its address.
1992 Likewise an array of elements of variable size. */
1993 if (TREE_CODE (index) != INTEGER_CST
1994 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
1995 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
1996 {
1997 if (!c_mark_addressable (array))
1998 return error_mark_node;
1999 }
2000 /* An array that is indexed by a constant value which is not within
2001 the array bounds cannot be stored in a register either; because we
2002 would get a crash in store_bit_field/extract_bit_field when trying
2003 to access a non-existent part of the register. */
2004 if (TREE_CODE (index) == INTEGER_CST
2005 && TYPE_DOMAIN (TREE_TYPE (array))
2006 && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array))))
2007 {
2008 if (!c_mark_addressable (array))
2009 return error_mark_node;
2010 }
2011
2012 if (pedantic)
2013 {
2014 tree foo = array;
2015 while (TREE_CODE (foo) == COMPONENT_REF)
2016 foo = TREE_OPERAND (foo, 0);
2017 if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo))
2018 pedwarn ("ISO C forbids subscripting %<register%> array");
2019 else if (!flag_isoc99 && !lvalue_p (foo))
2020 pedwarn ("ISO C90 forbids subscripting non-lvalue array");
2021 }
2022
2023 type = TREE_TYPE (TREE_TYPE (array));
2024 if (TREE_CODE (type) != ARRAY_TYPE)
2025 type = TYPE_MAIN_VARIANT (type);
2026 rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE);
2027 /* Array ref is const/volatile if the array elements are
2028 or if the array is. */
2029 TREE_READONLY (rval)
2030 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
2031 | TREE_READONLY (array));
2032 TREE_SIDE_EFFECTS (rval)
2033 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2034 | TREE_SIDE_EFFECTS (array));
2035 TREE_THIS_VOLATILE (rval)
2036 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
2037 /* This was added by rms on 16 Nov 91.
2038 It fixes vol struct foo *a; a->elts[1]
2039 in an inline function.
2040 Hope it doesn't break something else. */
2041 | TREE_THIS_VOLATILE (array));
2042 return require_complete_type (fold (rval));
2043 }
2044 else
2045 {
2046 tree ar = default_conversion (array);
2047
2048 if (ar == error_mark_node)
2049 return ar;
2050
2051 gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE);
2052 gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE);
2053
2054 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0),
2055 "array indexing");
2056 }
2057 }
2058 \f
2059 /* Build an external reference to identifier ID. FUN indicates
2060 whether this will be used for a function call. LOC is the source
2061 location of the identifier. */
2062 tree
2063 build_external_ref (tree id, int fun, location_t loc)
2064 {
2065 tree ref;
2066 tree decl = lookup_name (id);
2067
2068 /* In Objective-C, an instance variable (ivar) may be preferred to
2069 whatever lookup_name() found. */
2070 decl = objc_lookup_ivar (decl, id);
2071
2072 if (decl && decl != error_mark_node)
2073 ref = decl;
2074 else if (fun)
2075 /* Implicit function declaration. */
2076 ref = implicitly_declare (id);
2077 else if (decl == error_mark_node)
2078 /* Don't complain about something that's already been
2079 complained about. */
2080 return error_mark_node;
2081 else
2082 {
2083 undeclared_variable (id, loc);
2084 return error_mark_node;
2085 }
2086
2087 if (TREE_TYPE (ref) == error_mark_node)
2088 return error_mark_node;
2089
2090 if (TREE_DEPRECATED (ref))
2091 warn_deprecated_use (ref);
2092
2093 /* Recursive call does not count as usage. */
2094 if (ref != current_function_decl)
2095 {
2096 if (!skip_evaluation)
2097 assemble_external (ref);
2098 TREE_USED (ref) = 1;
2099 }
2100
2101 if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof)
2102 {
2103 if (!in_sizeof && !in_typeof)
2104 C_DECL_USED (ref) = 1;
2105 else if (DECL_INITIAL (ref) == 0
2106 && DECL_EXTERNAL (ref)
2107 && !TREE_PUBLIC (ref))
2108 record_maybe_used_decl (ref);
2109 }
2110
2111 if (TREE_CODE (ref) == CONST_DECL)
2112 {
2113 used_types_insert (TREE_TYPE (ref));
2114 ref = DECL_INITIAL (ref);
2115 TREE_CONSTANT (ref) = 1;
2116 TREE_INVARIANT (ref) = 1;
2117 }
2118 else if (current_function_decl != 0
2119 && !DECL_FILE_SCOPE_P (current_function_decl)
2120 && (TREE_CODE (ref) == VAR_DECL
2121 || TREE_CODE (ref) == PARM_DECL
2122 || TREE_CODE (ref) == FUNCTION_DECL))
2123 {
2124 tree context = decl_function_context (ref);
2125
2126 if (context != 0 && context != current_function_decl)
2127 DECL_NONLOCAL (ref) = 1;
2128 }
2129 /* C99 6.7.4p3: An inline definition of a function with external
2130 linkage ... shall not contain a reference to an identifier with
2131 internal linkage. */
2132 else if (current_function_decl != 0
2133 && DECL_DECLARED_INLINE_P (current_function_decl)
2134 && DECL_EXTERNAL (current_function_decl)
2135 && VAR_OR_FUNCTION_DECL_P (ref)
2136 && (TREE_CODE (ref) != VAR_DECL || TREE_STATIC (ref))
2137 && ! TREE_PUBLIC (ref))
2138 pedwarn ("%H%qD is static but used in inline function %qD "
2139 "which is not static", &loc, ref, current_function_decl);
2140
2141 return ref;
2142 }
2143
2144 /* Record details of decls possibly used inside sizeof or typeof. */
2145 struct maybe_used_decl
2146 {
2147 /* The decl. */
2148 tree decl;
2149 /* The level seen at (in_sizeof + in_typeof). */
2150 int level;
2151 /* The next one at this level or above, or NULL. */
2152 struct maybe_used_decl *next;
2153 };
2154
2155 static struct maybe_used_decl *maybe_used_decls;
2156
2157 /* Record that DECL, an undefined static function reference seen
2158 inside sizeof or typeof, might be used if the operand of sizeof is
2159 a VLA type or the operand of typeof is a variably modified
2160 type. */
2161
2162 static void
2163 record_maybe_used_decl (tree decl)
2164 {
2165 struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl);
2166 t->decl = decl;
2167 t->level = in_sizeof + in_typeof;
2168 t->next = maybe_used_decls;
2169 maybe_used_decls = t;
2170 }
2171
2172 /* Pop the stack of decls possibly used inside sizeof or typeof. If
2173 USED is false, just discard them. If it is true, mark them used
2174 (if no longer inside sizeof or typeof) or move them to the next
2175 level up (if still inside sizeof or typeof). */
2176
2177 void
2178 pop_maybe_used (bool used)
2179 {
2180 struct maybe_used_decl *p = maybe_used_decls;
2181 int cur_level = in_sizeof + in_typeof;
2182 while (p && p->level > cur_level)
2183 {
2184 if (used)
2185 {
2186 if (cur_level == 0)
2187 C_DECL_USED (p->decl) = 1;
2188 else
2189 p->level = cur_level;
2190 }
2191 p = p->next;
2192 }
2193 if (!used || cur_level == 0)
2194 maybe_used_decls = p;
2195 }
2196
2197 /* Return the result of sizeof applied to EXPR. */
2198
2199 struct c_expr
2200 c_expr_sizeof_expr (struct c_expr expr)
2201 {
2202 struct c_expr ret;
2203 if (expr.value == error_mark_node)
2204 {
2205 ret.value = error_mark_node;
2206 ret.original_code = ERROR_MARK;
2207 pop_maybe_used (false);
2208 }
2209 else
2210 {
2211 ret.value = c_sizeof (TREE_TYPE (expr.value));
2212 ret.original_code = ERROR_MARK;
2213 if (c_vla_type_p (TREE_TYPE (expr.value)))
2214 {
2215 /* sizeof is evaluated when given a vla (C99 6.5.3.4p2). */
2216 ret.value = build2 (COMPOUND_EXPR, TREE_TYPE (ret.value), expr.value, ret.value);
2217 }
2218 pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value)));
2219 }
2220 return ret;
2221 }
2222
2223 /* Return the result of sizeof applied to T, a structure for the type
2224 name passed to sizeof (rather than the type itself). */
2225
2226 struct c_expr
2227 c_expr_sizeof_type (struct c_type_name *t)
2228 {
2229 tree type;
2230 struct c_expr ret;
2231 type = groktypename (t);
2232 ret.value = c_sizeof (type);
2233 ret.original_code = ERROR_MARK;
2234 pop_maybe_used (type != error_mark_node
2235 ? C_TYPE_VARIABLE_SIZE (type) : false);
2236 return ret;
2237 }
2238
2239 /* Build a function call to function FUNCTION with parameters PARAMS.
2240 PARAMS is a list--a chain of TREE_LIST nodes--in which the
2241 TREE_VALUE of each node is a parameter-expression.
2242 FUNCTION's data type may be a function type or a pointer-to-function. */
2243
2244 tree
2245 build_function_call (tree function, tree params)
2246 {
2247 tree fntype, fundecl = 0;
2248 tree name = NULL_TREE, result;
2249 tree tem;
2250 int nargs;
2251 tree *argarray;
2252
2253
2254 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
2255 STRIP_TYPE_NOPS (function);
2256
2257 /* Convert anything with function type to a pointer-to-function. */
2258 if (TREE_CODE (function) == FUNCTION_DECL)
2259 {
2260 /* Implement type-directed function overloading for builtins.
2261 resolve_overloaded_builtin and targetm.resolve_overloaded_builtin
2262 handle all the type checking. The result is a complete expression
2263 that implements this function call. */
2264 tem = resolve_overloaded_builtin (function, params);
2265 if (tem)
2266 return tem;
2267
2268 name = DECL_NAME (function);
2269 fundecl = function;
2270 }
2271 if (TREE_CODE (TREE_TYPE (function)) == FUNCTION_TYPE)
2272 function = function_to_pointer_conversion (function);
2273
2274 /* For Objective-C, convert any calls via a cast to OBJC_TYPE_REF
2275 expressions, like those used for ObjC messenger dispatches. */
2276 function = objc_rewrite_function_call (function, params);
2277
2278 fntype = TREE_TYPE (function);
2279
2280 if (TREE_CODE (fntype) == ERROR_MARK)
2281 return error_mark_node;
2282
2283 if (!(TREE_CODE (fntype) == POINTER_TYPE
2284 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
2285 {
2286 error ("called object %qE is not a function", function);
2287 return error_mark_node;
2288 }
2289
2290 if (fundecl && TREE_THIS_VOLATILE (fundecl))
2291 current_function_returns_abnormally = 1;
2292
2293 /* fntype now gets the type of function pointed to. */
2294 fntype = TREE_TYPE (fntype);
2295
2296 /* Check that the function is called through a compatible prototype.
2297 If it is not, replace the call by a trap, wrapped up in a compound
2298 expression if necessary. This has the nice side-effect to prevent
2299 the tree-inliner from generating invalid assignment trees which may
2300 blow up in the RTL expander later. */
2301 if ((TREE_CODE (function) == NOP_EXPR
2302 || TREE_CODE (function) == CONVERT_EXPR)
2303 && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR
2304 && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL
2305 && !comptypes (fntype, TREE_TYPE (tem)))
2306 {
2307 tree return_type = TREE_TYPE (fntype);
2308 tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP],
2309 NULL_TREE);
2310
2311 /* This situation leads to run-time undefined behavior. We can't,
2312 therefore, simply error unless we can prove that all possible
2313 executions of the program must execute the code. */
2314 warning (0, "function called through a non-compatible type");
2315
2316 /* We can, however, treat "undefined" any way we please.
2317 Call abort to encourage the user to fix the program. */
2318 inform ("if this code is reached, the program will abort");
2319
2320 if (VOID_TYPE_P (return_type))
2321 return trap;
2322 else
2323 {
2324 tree rhs;
2325
2326 if (AGGREGATE_TYPE_P (return_type))
2327 rhs = build_compound_literal (return_type,
2328 build_constructor (return_type, 0));
2329 else
2330 rhs = fold_convert (return_type, integer_zero_node);
2331
2332 return build2 (COMPOUND_EXPR, return_type, trap, rhs);
2333 }
2334 }
2335
2336 /* Convert the parameters to the types declared in the
2337 function prototype, or apply default promotions. */
2338
2339 nargs = list_length (params);
2340 argarray = (tree *) alloca (nargs * sizeof (tree));
2341 nargs = convert_arguments (nargs, argarray, TYPE_ARG_TYPES (fntype),
2342 params, function, fundecl);
2343 if (nargs < 0)
2344 return error_mark_node;
2345
2346 /* Check that the arguments to the function are valid. */
2347
2348 check_function_arguments (TYPE_ATTRIBUTES (fntype), nargs, argarray,
2349 TYPE_ARG_TYPES (fntype));
2350
2351 if (require_constant_value)
2352 {
2353 result = fold_build_call_array_initializer (TREE_TYPE (fntype),
2354 function, nargs, argarray);
2355 if (TREE_CONSTANT (result)
2356 && (name == NULL_TREE
2357 || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0))
2358 pedwarn_init ("initializer element is not constant");
2359 }
2360 else
2361 result = fold_build_call_array (TREE_TYPE (fntype),
2362 function, nargs, argarray);
2363
2364 if (VOID_TYPE_P (TREE_TYPE (result)))
2365 return result;
2366 return require_complete_type (result);
2367 }
2368 \f
2369 /* Convert the argument expressions in the list VALUES
2370 to the types in the list TYPELIST. The resulting arguments are
2371 stored in the array ARGARRAY which has size NARGS.
2372
2373 If TYPELIST is exhausted, or when an element has NULL as its type,
2374 perform the default conversions.
2375
2376 PARMLIST is the chain of parm decls for the function being called.
2377 It may be 0, if that info is not available.
2378 It is used only for generating error messages.
2379
2380 FUNCTION is a tree for the called function. It is used only for
2381 error messages, where it is formatted with %qE.
2382
2383 This is also where warnings about wrong number of args are generated.
2384
2385 VALUES is a chain of TREE_LIST nodes with the elements of the list
2386 in the TREE_VALUE slots of those nodes.
2387
2388 Returns the actual number of arguments processed (which may be less
2389 than NARGS in some error situations), or -1 on failure. */
2390
2391 static int
2392 convert_arguments (int nargs, tree *argarray,
2393 tree typelist, tree values, tree function, tree fundecl)
2394 {
2395 tree typetail, valtail;
2396 int parmnum;
2397 const bool type_generic = fundecl
2398 && lookup_attribute ("type generic", TYPE_ATTRIBUTES(TREE_TYPE (fundecl)));
2399 tree selector;
2400
2401 /* Change pointer to function to the function itself for
2402 diagnostics. */
2403 if (TREE_CODE (function) == ADDR_EXPR
2404 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
2405 function = TREE_OPERAND (function, 0);
2406
2407 /* Handle an ObjC selector specially for diagnostics. */
2408 selector = objc_message_selector ();
2409
2410 /* Scan the given expressions and types, producing individual
2411 converted arguments and storing them in ARGARRAY. */
2412
2413 for (valtail = values, typetail = typelist, parmnum = 0;
2414 valtail;
2415 valtail = TREE_CHAIN (valtail), parmnum++)
2416 {
2417 tree type = typetail ? TREE_VALUE (typetail) : 0;
2418 tree val = TREE_VALUE (valtail);
2419 tree rname = function;
2420 int argnum = parmnum + 1;
2421 const char *invalid_func_diag;
2422
2423 if (type == void_type_node)
2424 {
2425 error ("too many arguments to function %qE", function);
2426 return parmnum;
2427 }
2428
2429 if (selector && argnum > 2)
2430 {
2431 rname = selector;
2432 argnum -= 2;
2433 }
2434
2435 STRIP_TYPE_NOPS (val);
2436
2437 val = require_complete_type (val);
2438
2439 if (type != 0)
2440 {
2441 /* Formal parm type is specified by a function prototype. */
2442 tree parmval;
2443
2444 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2445 {
2446 error ("type of formal parameter %d is incomplete", parmnum + 1);
2447 parmval = val;
2448 }
2449 else
2450 {
2451 /* Optionally warn about conversions that
2452 differ from the default conversions. */
2453 if (warn_traditional_conversion || warn_traditional)
2454 {
2455 unsigned int formal_prec = TYPE_PRECISION (type);
2456
2457 if (INTEGRAL_TYPE_P (type)
2458 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2459 warning (0, "passing argument %d of %qE as integer "
2460 "rather than floating due to prototype",
2461 argnum, rname);
2462 if (INTEGRAL_TYPE_P (type)
2463 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2464 warning (0, "passing argument %d of %qE as integer "
2465 "rather than complex due to prototype",
2466 argnum, rname);
2467 else if (TREE_CODE (type) == COMPLEX_TYPE
2468 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2469 warning (0, "passing argument %d of %qE as complex "
2470 "rather than floating due to prototype",
2471 argnum, rname);
2472 else if (TREE_CODE (type) == REAL_TYPE
2473 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2474 warning (0, "passing argument %d of %qE as floating "
2475 "rather than integer due to prototype",
2476 argnum, rname);
2477 else if (TREE_CODE (type) == COMPLEX_TYPE
2478 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2479 warning (0, "passing argument %d of %qE as complex "
2480 "rather than integer due to prototype",
2481 argnum, rname);
2482 else if (TREE_CODE (type) == REAL_TYPE
2483 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
2484 warning (0, "passing argument %d of %qE as floating "
2485 "rather than complex due to prototype",
2486 argnum, rname);
2487 /* ??? At some point, messages should be written about
2488 conversions between complex types, but that's too messy
2489 to do now. */
2490 else if (TREE_CODE (type) == REAL_TYPE
2491 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
2492 {
2493 /* Warn if any argument is passed as `float',
2494 since without a prototype it would be `double'. */
2495 if (formal_prec == TYPE_PRECISION (float_type_node)
2496 && type != dfloat32_type_node)
2497 warning (0, "passing argument %d of %qE as %<float%> "
2498 "rather than %<double%> due to prototype",
2499 argnum, rname);
2500
2501 /* Warn if mismatch between argument and prototype
2502 for decimal float types. Warn of conversions with
2503 binary float types and of precision narrowing due to
2504 prototype. */
2505 else if (type != TREE_TYPE (val)
2506 && (type == dfloat32_type_node
2507 || type == dfloat64_type_node
2508 || type == dfloat128_type_node
2509 || TREE_TYPE (val) == dfloat32_type_node
2510 || TREE_TYPE (val) == dfloat64_type_node
2511 || TREE_TYPE (val) == dfloat128_type_node)
2512 && (formal_prec
2513 <= TYPE_PRECISION (TREE_TYPE (val))
2514 || (type == dfloat128_type_node
2515 && (TREE_TYPE (val)
2516 != dfloat64_type_node
2517 && (TREE_TYPE (val)
2518 != dfloat32_type_node)))
2519 || (type == dfloat64_type_node
2520 && (TREE_TYPE (val)
2521 != dfloat32_type_node))))
2522 warning (0, "passing argument %d of %qE as %qT "
2523 "rather than %qT due to prototype",
2524 argnum, rname, type, TREE_TYPE (val));
2525
2526 }
2527 /* Detect integer changing in width or signedness.
2528 These warnings are only activated with
2529 -Wtraditional-conversion, not with -Wtraditional. */
2530 else if (warn_traditional_conversion && INTEGRAL_TYPE_P (type)
2531 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
2532 {
2533 tree would_have_been = default_conversion (val);
2534 tree type1 = TREE_TYPE (would_have_been);
2535
2536 if (TREE_CODE (type) == ENUMERAL_TYPE
2537 && (TYPE_MAIN_VARIANT (type)
2538 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
2539 /* No warning if function asks for enum
2540 and the actual arg is that enum type. */
2541 ;
2542 else if (formal_prec != TYPE_PRECISION (type1))
2543 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2544 "with different width due to prototype",
2545 argnum, rname);
2546 else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1))
2547 ;
2548 /* Don't complain if the formal parameter type
2549 is an enum, because we can't tell now whether
2550 the value was an enum--even the same enum. */
2551 else if (TREE_CODE (type) == ENUMERAL_TYPE)
2552 ;
2553 else if (TREE_CODE (val) == INTEGER_CST
2554 && int_fits_type_p (val, type))
2555 /* Change in signedness doesn't matter
2556 if a constant value is unaffected. */
2557 ;
2558 /* If the value is extended from a narrower
2559 unsigned type, it doesn't matter whether we
2560 pass it as signed or unsigned; the value
2561 certainly is the same either way. */
2562 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
2563 && TYPE_UNSIGNED (TREE_TYPE (val)))
2564 ;
2565 else if (TYPE_UNSIGNED (type))
2566 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2567 "as unsigned due to prototype",
2568 argnum, rname);
2569 else
2570 warning (OPT_Wtraditional_conversion, "passing argument %d of %qE "
2571 "as signed due to prototype", argnum, rname);
2572 }
2573 }
2574
2575 parmval = convert_for_assignment (type, val, ic_argpass,
2576 fundecl, function,
2577 parmnum + 1);
2578
2579 if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0)
2580 && INTEGRAL_TYPE_P (type)
2581 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
2582 parmval = default_conversion (parmval);
2583 }
2584 argarray[parmnum] = parmval;
2585 }
2586 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
2587 && (TYPE_PRECISION (TREE_TYPE (val))
2588 < TYPE_PRECISION (double_type_node))
2589 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (val))))
2590 {
2591 if (type_generic)
2592 argarray[parmnum] = val;
2593 else
2594 /* Convert `float' to `double'. */
2595 argarray[parmnum] = convert (double_type_node, val);
2596 }
2597 else if ((invalid_func_diag =
2598 targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val)))
2599 {
2600 error (invalid_func_diag);
2601 return -1;
2602 }
2603 else
2604 /* Convert `short' and `char' to full-size `int'. */
2605 argarray[parmnum] = default_conversion (val);
2606
2607 if (typetail)
2608 typetail = TREE_CHAIN (typetail);
2609 }
2610
2611 gcc_assert (parmnum == nargs);
2612
2613 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
2614 {
2615 error ("too few arguments to function %qE", function);
2616 return -1;
2617 }
2618
2619 return parmnum;
2620 }
2621 \f
2622 /* This is the entry point used by the parser to build unary operators
2623 in the input. CODE, a tree_code, specifies the unary operator, and
2624 ARG is the operand. For unary plus, the C parser currently uses
2625 CONVERT_EXPR for code. */
2626
2627 struct c_expr
2628 parser_build_unary_op (enum tree_code code, struct c_expr arg)
2629 {
2630 struct c_expr result;
2631
2632 result.original_code = ERROR_MARK;
2633 result.value = build_unary_op (code, arg.value, 0);
2634
2635 if (TREE_OVERFLOW_P (result.value) && !TREE_OVERFLOW_P (arg.value))
2636 overflow_warning (result.value);
2637
2638 return result;
2639 }
2640
2641 /* This is the entry point used by the parser to build binary operators
2642 in the input. CODE, a tree_code, specifies the binary operator, and
2643 ARG1 and ARG2 are the operands. In addition to constructing the
2644 expression, we check for operands that were written with other binary
2645 operators in a way that is likely to confuse the user. */
2646
2647 struct c_expr
2648 parser_build_binary_op (enum tree_code code, struct c_expr arg1,
2649 struct c_expr arg2)
2650 {
2651 struct c_expr result;
2652
2653 enum tree_code code1 = arg1.original_code;
2654 enum tree_code code2 = arg2.original_code;
2655
2656 result.value = build_binary_op (code, arg1.value, arg2.value, 1);
2657 result.original_code = code;
2658
2659 if (TREE_CODE (result.value) == ERROR_MARK)
2660 return result;
2661
2662 /* Check for cases such as x+y<<z which users are likely
2663 to misinterpret. */
2664 if (warn_parentheses)
2665 warn_about_parentheses (code, code1, code2);
2666
2667 if (code1 != tcc_comparison)
2668 warn_logical_operator (code, arg1.value, arg2.value);
2669
2670 /* Warn about comparisons against string literals, with the exception
2671 of testing for equality or inequality of a string literal with NULL. */
2672 if (code == EQ_EXPR || code == NE_EXPR)
2673 {
2674 if ((code1 == STRING_CST && !integer_zerop (arg2.value))
2675 || (code2 == STRING_CST && !integer_zerop (arg1.value)))
2676 warning (OPT_Waddress, "comparison with string literal results in unspecified behavior");
2677 }
2678 else if (TREE_CODE_CLASS (code) == tcc_comparison
2679 && (code1 == STRING_CST || code2 == STRING_CST))
2680 warning (OPT_Waddress, "comparison with string literal results in unspecified behavior");
2681
2682 if (TREE_OVERFLOW_P (result.value)
2683 && !TREE_OVERFLOW_P (arg1.value)
2684 && !TREE_OVERFLOW_P (arg2.value))
2685 overflow_warning (result.value);
2686
2687 return result;
2688 }
2689 \f
2690 /* Return a tree for the difference of pointers OP0 and OP1.
2691 The resulting tree has type int. */
2692
2693 static tree
2694 pointer_diff (tree op0, tree op1)
2695 {
2696 tree restype = ptrdiff_type_node;
2697
2698 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2699 tree con0, con1, lit0, lit1;
2700 tree orig_op1 = op1;
2701
2702 if (pedantic || warn_pointer_arith)
2703 {
2704 if (TREE_CODE (target_type) == VOID_TYPE)
2705 pedwarn ("pointer of type %<void *%> used in subtraction");
2706 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2707 pedwarn ("pointer to a function used in subtraction");
2708 }
2709
2710 /* If the conversion to ptrdiff_type does anything like widening or
2711 converting a partial to an integral mode, we get a convert_expression
2712 that is in the way to do any simplifications.
2713 (fold-const.c doesn't know that the extra bits won't be needed.
2714 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2715 different mode in place.)
2716 So first try to find a common term here 'by hand'; we want to cover
2717 at least the cases that occur in legal static initializers. */
2718 if ((TREE_CODE (op0) == NOP_EXPR || TREE_CODE (op0) == CONVERT_EXPR)
2719 && (TYPE_PRECISION (TREE_TYPE (op0))
2720 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
2721 con0 = TREE_OPERAND (op0, 0);
2722 else
2723 con0 = op0;
2724 if ((TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == CONVERT_EXPR)
2725 && (TYPE_PRECISION (TREE_TYPE (op1))
2726 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op1, 0)))))
2727 con1 = TREE_OPERAND (op1, 0);
2728 else
2729 con1 = op1;
2730
2731 if (TREE_CODE (con0) == PLUS_EXPR)
2732 {
2733 lit0 = TREE_OPERAND (con0, 1);
2734 con0 = TREE_OPERAND (con0, 0);
2735 }
2736 else
2737 lit0 = integer_zero_node;
2738
2739 if (TREE_CODE (con1) == PLUS_EXPR)
2740 {
2741 lit1 = TREE_OPERAND (con1, 1);
2742 con1 = TREE_OPERAND (con1, 0);
2743 }
2744 else
2745 lit1 = integer_zero_node;
2746
2747 if (operand_equal_p (con0, con1, 0))
2748 {
2749 op0 = lit0;
2750 op1 = lit1;
2751 }
2752
2753
2754 /* First do the subtraction as integers;
2755 then drop through to build the divide operator.
2756 Do not do default conversions on the minus operator
2757 in case restype is a short type. */
2758
2759 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2760 convert (restype, op1), 0);
2761 /* This generates an error if op1 is pointer to incomplete type. */
2762 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2763 error ("arithmetic on pointer to an incomplete type");
2764
2765 /* This generates an error if op0 is pointer to incomplete type. */
2766 op1 = c_size_in_bytes (target_type);
2767
2768 /* Divide by the size, in easiest possible way. */
2769 return fold_build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2770 }
2771 \f
2772 /* Construct and perhaps optimize a tree representation
2773 for a unary operation. CODE, a tree_code, specifies the operation
2774 and XARG is the operand.
2775 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2776 the default promotions (such as from short to int).
2777 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2778 allows non-lvalues; this is only used to handle conversion of non-lvalue
2779 arrays to pointers in C99. */
2780
2781 tree
2782 build_unary_op (enum tree_code code, tree xarg, int flag)
2783 {
2784 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2785 tree arg = xarg;
2786 tree argtype = 0;
2787 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2788 tree val;
2789 int noconvert = flag;
2790 const char *invalid_op_diag;
2791
2792 if (typecode == ERROR_MARK)
2793 return error_mark_node;
2794 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2795 typecode = INTEGER_TYPE;
2796
2797 if ((invalid_op_diag
2798 = targetm.invalid_unary_op (code, TREE_TYPE (xarg))))
2799 {
2800 error (invalid_op_diag);
2801 return error_mark_node;
2802 }
2803
2804 switch (code)
2805 {
2806 case CONVERT_EXPR:
2807 /* This is used for unary plus, because a CONVERT_EXPR
2808 is enough to prevent anybody from looking inside for
2809 associativity, but won't generate any code. */
2810 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2811 || typecode == COMPLEX_TYPE
2812 || typecode == VECTOR_TYPE))
2813 {
2814 error ("wrong type argument to unary plus");
2815 return error_mark_node;
2816 }
2817 else if (!noconvert)
2818 arg = default_conversion (arg);
2819 arg = non_lvalue (arg);
2820 break;
2821
2822 case NEGATE_EXPR:
2823 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2824 || typecode == COMPLEX_TYPE
2825 || typecode == VECTOR_TYPE))
2826 {
2827 error ("wrong type argument to unary minus");
2828 return error_mark_node;
2829 }
2830 else if (!noconvert)
2831 arg = default_conversion (arg);
2832 break;
2833
2834 case BIT_NOT_EXPR:
2835 /* ~ works on integer types and non float vectors. */
2836 if (typecode == INTEGER_TYPE
2837 || (typecode == VECTOR_TYPE
2838 && !VECTOR_FLOAT_TYPE_P (TREE_TYPE (arg))))
2839 {
2840 if (!noconvert)
2841 arg = default_conversion (arg);
2842 }
2843 else if (typecode == COMPLEX_TYPE)
2844 {
2845 code = CONJ_EXPR;
2846 if (pedantic)
2847 pedwarn ("ISO C does not support %<~%> for complex conjugation");
2848 if (!noconvert)
2849 arg = default_conversion (arg);
2850 }
2851 else
2852 {
2853 error ("wrong type argument to bit-complement");
2854 return error_mark_node;
2855 }
2856 break;
2857
2858 case ABS_EXPR:
2859 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE))
2860 {
2861 error ("wrong type argument to abs");
2862 return error_mark_node;
2863 }
2864 else if (!noconvert)
2865 arg = default_conversion (arg);
2866 break;
2867
2868 case CONJ_EXPR:
2869 /* Conjugating a real value is a no-op, but allow it anyway. */
2870 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2871 || typecode == COMPLEX_TYPE))
2872 {
2873 error ("wrong type argument to conjugation");
2874 return error_mark_node;
2875 }
2876 else if (!noconvert)
2877 arg = default_conversion (arg);
2878 break;
2879
2880 case TRUTH_NOT_EXPR:
2881 if (typecode != INTEGER_TYPE
2882 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2883 && typecode != COMPLEX_TYPE)
2884 {
2885 error ("wrong type argument to unary exclamation mark");
2886 return error_mark_node;
2887 }
2888 arg = c_objc_common_truthvalue_conversion (arg);
2889 return invert_truthvalue (arg);
2890
2891 case REALPART_EXPR:
2892 if (TREE_CODE (arg) == COMPLEX_CST)
2893 return TREE_REALPART (arg);
2894 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2895 return fold_build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2896 else
2897 return arg;
2898
2899 case IMAGPART_EXPR:
2900 if (TREE_CODE (arg) == COMPLEX_CST)
2901 return TREE_IMAGPART (arg);
2902 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2903 return fold_build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg);
2904 else
2905 return convert (TREE_TYPE (arg), integer_zero_node);
2906
2907 case PREINCREMENT_EXPR:
2908 case POSTINCREMENT_EXPR:
2909 case PREDECREMENT_EXPR:
2910 case POSTDECREMENT_EXPR:
2911
2912 /* Increment or decrement the real part of the value,
2913 and don't change the imaginary part. */
2914 if (typecode == COMPLEX_TYPE)
2915 {
2916 tree real, imag;
2917
2918 if (pedantic)
2919 pedwarn ("ISO C does not support %<++%> and %<--%>"
2920 " on complex types");
2921
2922 arg = stabilize_reference (arg);
2923 real = build_unary_op (REALPART_EXPR, arg, 1);
2924 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2925 real = build_unary_op (code, real, 1);
2926 if (real == error_mark_node || imag == error_mark_node)
2927 return error_mark_node;
2928 return build2 (COMPLEX_EXPR, TREE_TYPE (arg),
2929 real, imag);
2930 }
2931
2932 /* Report invalid types. */
2933
2934 if (typecode != POINTER_TYPE
2935 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2936 {
2937 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2938 error ("wrong type argument to increment");
2939 else
2940 error ("wrong type argument to decrement");
2941
2942 return error_mark_node;
2943 }
2944
2945 {
2946 tree inc;
2947 tree result_type = TREE_TYPE (arg);
2948
2949 arg = get_unwidened (arg, 0);
2950 argtype = TREE_TYPE (arg);
2951
2952 /* Compute the increment. */
2953
2954 if (typecode == POINTER_TYPE)
2955 {
2956 /* If pointer target is an undefined struct,
2957 we just cannot know how to do the arithmetic. */
2958 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2959 {
2960 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2961 error ("increment of pointer to unknown structure");
2962 else
2963 error ("decrement of pointer to unknown structure");
2964 }
2965 else if ((pedantic || warn_pointer_arith)
2966 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2967 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2968 {
2969 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2970 pedwarn ("wrong type argument to increment");
2971 else
2972 pedwarn ("wrong type argument to decrement");
2973 }
2974
2975 inc = c_size_in_bytes (TREE_TYPE (result_type));
2976 inc = fold_convert (sizetype, inc);
2977 }
2978 else
2979 {
2980 inc = integer_one_node;
2981 inc = convert (argtype, inc);
2982 }
2983
2984 /* Complain about anything else that is not a true lvalue. */
2985 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
2986 || code == POSTINCREMENT_EXPR)
2987 ? lv_increment
2988 : lv_decrement)))
2989 return error_mark_node;
2990
2991 /* Report a read-only lvalue. */
2992 if (TREE_READONLY (arg))
2993 {
2994 readonly_error (arg,
2995 ((code == PREINCREMENT_EXPR
2996 || code == POSTINCREMENT_EXPR)
2997 ? lv_increment : lv_decrement));
2998 return error_mark_node;
2999 }
3000
3001 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
3002 val = boolean_increment (code, arg);
3003 else
3004 val = build2 (code, TREE_TYPE (arg), arg, inc);
3005 TREE_SIDE_EFFECTS (val) = 1;
3006 val = convert (result_type, val);
3007 if (TREE_CODE (val) != code)
3008 TREE_NO_WARNING (val) = 1;
3009 return val;
3010 }
3011
3012 case ADDR_EXPR:
3013 /* Note that this operation never does default_conversion. */
3014
3015 /* Let &* cancel out to simplify resulting code. */
3016 if (TREE_CODE (arg) == INDIRECT_REF)
3017 {
3018 /* Don't let this be an lvalue. */
3019 if (lvalue_p (TREE_OPERAND (arg, 0)))
3020 return non_lvalue (TREE_OPERAND (arg, 0));
3021 return TREE_OPERAND (arg, 0);
3022 }
3023
3024 /* For &x[y], return x+y */
3025 if (TREE_CODE (arg) == ARRAY_REF)
3026 {
3027 tree op0 = TREE_OPERAND (arg, 0);
3028 if (!c_mark_addressable (op0))
3029 return error_mark_node;
3030 return build_binary_op (PLUS_EXPR,
3031 (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE
3032 ? array_to_pointer_conversion (op0)
3033 : op0),
3034 TREE_OPERAND (arg, 1), 1);
3035 }
3036
3037 /* Anything not already handled and not a true memory reference
3038 or a non-lvalue array is an error. */
3039 else if (typecode != FUNCTION_TYPE && !flag
3040 && !lvalue_or_else (arg, lv_addressof))
3041 return error_mark_node;
3042
3043 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3044 argtype = TREE_TYPE (arg);
3045
3046 /* If the lvalue is const or volatile, merge that into the type
3047 to which the address will point. Note that you can't get a
3048 restricted pointer by taking the address of something, so we
3049 only have to deal with `const' and `volatile' here. */
3050 if ((DECL_P (arg) || REFERENCE_CLASS_P (arg))
3051 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3052 argtype = c_build_type_variant (argtype,
3053 TREE_READONLY (arg),
3054 TREE_THIS_VOLATILE (arg));
3055
3056 if (!c_mark_addressable (arg))
3057 return error_mark_node;
3058
3059 gcc_assert (TREE_CODE (arg) != COMPONENT_REF
3060 || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1)));
3061
3062 argtype = build_pointer_type (argtype);
3063
3064 /* ??? Cope with user tricks that amount to offsetof. Delete this
3065 when we have proper support for integer constant expressions. */
3066 val = get_base_address (arg);
3067 if (val && TREE_CODE (val) == INDIRECT_REF
3068 && TREE_CONSTANT (TREE_OPERAND (val, 0)))
3069 {
3070 tree op0 = fold_convert (sizetype, fold_offsetof (arg, val)), op1;
3071
3072 op1 = fold_convert (argtype, TREE_OPERAND (val, 0));
3073 return fold_build2 (POINTER_PLUS_EXPR, argtype, op1, op0);
3074 }
3075
3076 val = build1 (ADDR_EXPR, argtype, arg);
3077
3078 return val;
3079
3080 default:
3081 gcc_unreachable ();
3082 }
3083
3084 if (argtype == 0)
3085 argtype = TREE_TYPE (arg);
3086 return require_constant_value ? fold_build1_initializer (code, argtype, arg)
3087 : fold_build1 (code, argtype, arg);
3088 }
3089
3090 /* Return nonzero if REF is an lvalue valid for this language.
3091 Lvalues can be assigned, unless their type has TYPE_READONLY.
3092 Lvalues can have their address taken, unless they have C_DECL_REGISTER. */
3093
3094 static int
3095 lvalue_p (tree ref)
3096 {
3097 enum tree_code code = TREE_CODE (ref);
3098
3099 switch (code)
3100 {
3101 case REALPART_EXPR:
3102 case IMAGPART_EXPR:
3103 case COMPONENT_REF:
3104 return lvalue_p (TREE_OPERAND (ref, 0));
3105
3106 case COMPOUND_LITERAL_EXPR:
3107 case STRING_CST:
3108 return 1;
3109
3110 case INDIRECT_REF:
3111 case ARRAY_REF:
3112 case VAR_DECL:
3113 case PARM_DECL:
3114 case RESULT_DECL:
3115 case ERROR_MARK:
3116 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3117 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3118
3119 case BIND_EXPR:
3120 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3121
3122 default:
3123 return 0;
3124 }
3125 }
3126 \f
3127 /* Give an error for storing in something that is 'const'. */
3128
3129 static void
3130 readonly_error (tree arg, enum lvalue_use use)
3131 {
3132 gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement
3133 || use == lv_asm);
3134 /* Using this macro rather than (for example) arrays of messages
3135 ensures that all the format strings are checked at compile
3136 time. */
3137 #define READONLY_MSG(A, I, D, AS) (use == lv_assign ? (A) \
3138 : (use == lv_increment ? (I) \
3139 : (use == lv_decrement ? (D) : (AS))))
3140 if (TREE_CODE (arg) == COMPONENT_REF)
3141 {
3142 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3143 readonly_error (TREE_OPERAND (arg, 0), use);
3144 else
3145 error (READONLY_MSG (G_("assignment of read-only member %qD"),
3146 G_("increment of read-only member %qD"),
3147 G_("decrement of read-only member %qD"),
3148 G_("read-only member %qD used as %<asm%> output")),
3149 TREE_OPERAND (arg, 1));
3150 }
3151 else if (TREE_CODE (arg) == VAR_DECL)
3152 error (READONLY_MSG (G_("assignment of read-only variable %qD"),
3153 G_("increment of read-only variable %qD"),
3154 G_("decrement of read-only variable %qD"),
3155 G_("read-only variable %qD used as %<asm%> output")),
3156 arg);
3157 else
3158 error (READONLY_MSG (G_("assignment of read-only location %qE"),
3159 G_("increment of read-only location %qE"),
3160 G_("decrement of read-only location %qE"),
3161 G_("read-only location %qE used as %<asm%> output")),
3162 arg);
3163 }
3164
3165
3166 /* Return nonzero if REF is an lvalue valid for this language;
3167 otherwise, print an error message and return zero. USE says
3168 how the lvalue is being used and so selects the error message. */
3169
3170 static int
3171 lvalue_or_else (tree ref, enum lvalue_use use)
3172 {
3173 int win = lvalue_p (ref);
3174
3175 if (!win)
3176 lvalue_error (use);
3177
3178 return win;
3179 }
3180 \f
3181 /* Mark EXP saying that we need to be able to take the
3182 address of it; it should not be allocated in a register.
3183 Returns true if successful. */
3184
3185 bool
3186 c_mark_addressable (tree exp)
3187 {
3188 tree x = exp;
3189
3190 while (1)
3191 switch (TREE_CODE (x))
3192 {
3193 case COMPONENT_REF:
3194 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3195 {
3196 error
3197 ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1));
3198 return false;
3199 }
3200
3201 /* ... fall through ... */
3202
3203 case ADDR_EXPR:
3204 case ARRAY_REF:
3205 case REALPART_EXPR:
3206 case IMAGPART_EXPR:
3207 x = TREE_OPERAND (x, 0);
3208 break;
3209
3210 case COMPOUND_LITERAL_EXPR:
3211 case CONSTRUCTOR:
3212 TREE_ADDRESSABLE (x) = 1;
3213 return true;
3214
3215 case VAR_DECL:
3216 case CONST_DECL:
3217 case PARM_DECL:
3218 case RESULT_DECL:
3219 if (C_DECL_REGISTER (x)
3220 && DECL_NONLOCAL (x))
3221 {
3222 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3223 {
3224 error
3225 ("global register variable %qD used in nested function", x);
3226 return false;
3227 }
3228 pedwarn ("register variable %qD used in nested function", x);
3229 }
3230 else if (C_DECL_REGISTER (x))
3231 {
3232 if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x))
3233 error ("address of global register variable %qD requested", x);
3234 else
3235 error ("address of register variable %qD requested", x);
3236 return false;
3237 }
3238
3239 /* drops in */
3240 case FUNCTION_DECL:
3241 TREE_ADDRESSABLE (x) = 1;
3242 /* drops out */
3243 default:
3244 return true;
3245 }
3246 }
3247 \f
3248 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3249
3250 tree
3251 build_conditional_expr (tree ifexp, tree op1, tree op2)
3252 {
3253 tree type1;
3254 tree type2;
3255 enum tree_code code1;
3256 enum tree_code code2;
3257 tree result_type = NULL;
3258 tree orig_op1 = op1, orig_op2 = op2;
3259
3260 /* Promote both alternatives. */
3261
3262 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3263 op1 = default_conversion (op1);
3264 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3265 op2 = default_conversion (op2);
3266
3267 if (TREE_CODE (ifexp) == ERROR_MARK
3268 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3269 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3270 return error_mark_node;
3271
3272 type1 = TREE_TYPE (op1);
3273 code1 = TREE_CODE (type1);
3274 type2 = TREE_TYPE (op2);
3275 code2 = TREE_CODE (type2);
3276
3277 /* C90 does not permit non-lvalue arrays in conditional expressions.
3278 In C99 they will be pointers by now. */
3279 if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE)
3280 {
3281 error ("non-lvalue array in conditional expression");
3282 return error_mark_node;
3283 }
3284
3285 /* Quickly detect the usual case where op1 and op2 have the same type
3286 after promotion. */
3287 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3288 {
3289 if (type1 == type2)
3290 result_type = type1;
3291 else
3292 result_type = TYPE_MAIN_VARIANT (type1);
3293 }
3294 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3295 || code1 == COMPLEX_TYPE)
3296 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3297 || code2 == COMPLEX_TYPE))
3298 {
3299 result_type = c_common_type (type1, type2);
3300
3301 /* If -Wsign-compare, warn here if type1 and type2 have
3302 different signedness. We'll promote the signed to unsigned
3303 and later code won't know it used to be different.
3304 Do this check on the original types, so that explicit casts
3305 will be considered, but default promotions won't. */
3306 if (warn_sign_compare && !skip_evaluation)
3307 {
3308 int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1));
3309 int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2));
3310
3311 if (unsigned_op1 ^ unsigned_op2)
3312 {
3313 bool ovf;
3314
3315 /* Do not warn if the result type is signed, since the
3316 signed type will only be chosen if it can represent
3317 all the values of the unsigned type. */
3318 if (!TYPE_UNSIGNED (result_type))
3319 /* OK */;
3320 /* Do not warn if the signed quantity is an unsuffixed
3321 integer literal (or some static constant expression
3322 involving such literals) and it is non-negative. */
3323 else if ((unsigned_op2
3324 && tree_expr_nonnegative_warnv_p (op1, &ovf))
3325 || (unsigned_op1
3326 && tree_expr_nonnegative_warnv_p (op2, &ovf)))
3327 /* OK */;
3328 else
3329 warning (0, "signed and unsigned type in conditional expression");
3330 }
3331 }
3332 }
3333 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3334 {
3335 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3336 pedwarn ("ISO C forbids conditional expr with only one void side");
3337 result_type = void_type_node;
3338 }
3339 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3340 {
3341 if (comp_target_types (type1, type2))
3342 result_type = common_pointer_type (type1, type2);
3343 else if (null_pointer_constant_p (orig_op1))
3344 result_type = qualify_type (type2, type1);
3345 else if (null_pointer_constant_p (orig_op2))
3346 result_type = qualify_type (type1, type2);
3347 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3348 {
3349 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3350 pedwarn ("ISO C forbids conditional expr between "
3351 "%<void *%> and function pointer");
3352 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3353 TREE_TYPE (type2)));
3354 }
3355 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3356 {
3357 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3358 pedwarn ("ISO C forbids conditional expr between "
3359 "%<void *%> and function pointer");
3360 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3361 TREE_TYPE (type1)));
3362 }
3363 else
3364 {
3365 pedwarn ("pointer type mismatch in conditional expression");
3366 result_type = build_pointer_type (void_type_node);
3367 }
3368 }
3369 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3370 {
3371 if (!null_pointer_constant_p (orig_op2))
3372 pedwarn ("pointer/integer type mismatch in conditional expression");
3373 else
3374 {
3375 op2 = null_pointer_node;
3376 }
3377 result_type = type1;
3378 }
3379 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3380 {
3381 if (!null_pointer_constant_p (orig_op1))
3382 pedwarn ("pointer/integer type mismatch in conditional expression");
3383 else
3384 {
3385 op1 = null_pointer_node;
3386 }
3387 result_type = type2;
3388 }
3389
3390 if (!result_type)
3391 {
3392 if (flag_cond_mismatch)
3393 result_type = void_type_node;
3394 else
3395 {
3396 error ("type mismatch in conditional expression");
3397 return error_mark_node;
3398 }
3399 }
3400
3401 /* Merge const and volatile flags of the incoming types. */
3402 result_type
3403 = build_type_variant (result_type,
3404 TREE_READONLY (op1) || TREE_READONLY (op2),
3405 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3406
3407 if (result_type != TREE_TYPE (op1))
3408 op1 = convert_and_check (result_type, op1);
3409 if (result_type != TREE_TYPE (op2))
3410 op2 = convert_and_check (result_type, op2);
3411
3412 return fold_build3 (COND_EXPR, result_type, ifexp, op1, op2);
3413 }
3414 \f
3415 /* Return a compound expression that performs two expressions and
3416 returns the value of the second of them. */
3417
3418 tree
3419 build_compound_expr (tree expr1, tree expr2)
3420 {
3421 if (!TREE_SIDE_EFFECTS (expr1))
3422 {
3423 /* The left-hand operand of a comma expression is like an expression
3424 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3425 any side-effects, unless it was explicitly cast to (void). */
3426 if (warn_unused_value)
3427 {
3428 if (VOID_TYPE_P (TREE_TYPE (expr1))
3429 && (TREE_CODE (expr1) == NOP_EXPR
3430 || TREE_CODE (expr1) == CONVERT_EXPR))
3431 ; /* (void) a, b */
3432 else if (VOID_TYPE_P (TREE_TYPE (expr1))
3433 && TREE_CODE (expr1) == COMPOUND_EXPR
3434 && (TREE_CODE (TREE_OPERAND (expr1, 1)) == CONVERT_EXPR
3435 || TREE_CODE (TREE_OPERAND (expr1, 1)) == NOP_EXPR))
3436 ; /* (void) a, (void) b, c */
3437 else
3438 warning (OPT_Wunused_value,
3439 "left-hand operand of comma expression has no effect");
3440 }
3441 }
3442
3443 /* With -Wunused, we should also warn if the left-hand operand does have
3444 side-effects, but computes a value which is not used. For example, in
3445 `foo() + bar(), baz()' the result of the `+' operator is not used,
3446 so we should issue a warning. */
3447 else if (warn_unused_value)
3448 warn_if_unused_value (expr1, input_location);
3449
3450 if (expr2 == error_mark_node)
3451 return error_mark_node;
3452
3453 return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2);
3454 }
3455
3456 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3457
3458 tree
3459 build_c_cast (tree type, tree expr)
3460 {
3461 tree value = expr;
3462
3463 if (type == error_mark_node || expr == error_mark_node)
3464 return error_mark_node;
3465
3466 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3467 only in <protocol> qualifications. But when constructing cast expressions,
3468 the protocols do matter and must be kept around. */
3469 if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr)))
3470 return build1 (NOP_EXPR, type, expr);
3471
3472 type = TYPE_MAIN_VARIANT (type);
3473
3474 if (TREE_CODE (type) == ARRAY_TYPE)
3475 {
3476 error ("cast specifies array type");
3477 return error_mark_node;
3478 }
3479
3480 if (TREE_CODE (type) == FUNCTION_TYPE)
3481 {
3482 error ("cast specifies function type");
3483 return error_mark_node;
3484 }
3485
3486 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3487 {
3488 if (pedantic)
3489 {
3490 if (TREE_CODE (type) == RECORD_TYPE
3491 || TREE_CODE (type) == UNION_TYPE)
3492 pedwarn ("ISO C forbids casting nonscalar to the same type");
3493 }
3494 }
3495 else if (TREE_CODE (type) == UNION_TYPE)
3496 {
3497 tree field;
3498
3499 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3500 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3501 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3502 break;
3503
3504 if (field)
3505 {
3506 tree t;
3507
3508 if (pedantic)
3509 pedwarn ("ISO C forbids casts to union type");
3510 t = digest_init (type,
3511 build_constructor_single (type, field, value),
3512 true, 0);
3513 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3514 TREE_INVARIANT (t) = TREE_INVARIANT (value);
3515 return t;
3516 }
3517 error ("cast to union type from type not present in union");
3518 return error_mark_node;
3519 }
3520 else
3521 {
3522 tree otype, ovalue;
3523
3524 if (type == void_type_node)
3525 return build1 (CONVERT_EXPR, type, value);
3526
3527 otype = TREE_TYPE (value);
3528
3529 /* Optionally warn about potentially worrisome casts. */
3530
3531 if (warn_cast_qual
3532 && TREE_CODE (type) == POINTER_TYPE
3533 && TREE_CODE (otype) == POINTER_TYPE)
3534 {
3535 tree in_type = type;
3536 tree in_otype = otype;
3537 int added = 0;
3538 int discarded = 0;
3539
3540 /* Check that the qualifiers on IN_TYPE are a superset of
3541 the qualifiers of IN_OTYPE. The outermost level of
3542 POINTER_TYPE nodes is uninteresting and we stop as soon
3543 as we hit a non-POINTER_TYPE node on either type. */
3544 do
3545 {
3546 in_otype = TREE_TYPE (in_otype);
3547 in_type = TREE_TYPE (in_type);
3548
3549 /* GNU C allows cv-qualified function types. 'const'
3550 means the function is very pure, 'volatile' means it
3551 can't return. We need to warn when such qualifiers
3552 are added, not when they're taken away. */
3553 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3554 && TREE_CODE (in_type) == FUNCTION_TYPE)
3555 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3556 else
3557 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3558 }
3559 while (TREE_CODE (in_type) == POINTER_TYPE
3560 && TREE_CODE (in_otype) == POINTER_TYPE);
3561
3562 if (added)
3563 warning (OPT_Wcast_qual, "cast adds new qualifiers to function type");
3564
3565 if (discarded)
3566 /* There are qualifiers present in IN_OTYPE that are not
3567 present in IN_TYPE. */
3568 warning (OPT_Wcast_qual, "cast discards qualifiers from pointer target type");
3569 }
3570
3571 /* Warn about possible alignment problems. */
3572 if (STRICT_ALIGNMENT
3573 && TREE_CODE (type) == POINTER_TYPE
3574 && TREE_CODE (otype) == POINTER_TYPE
3575 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3576 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3577 /* Don't warn about opaque types, where the actual alignment
3578 restriction is unknown. */
3579 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3580 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3581 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3582 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3583 warning (OPT_Wcast_align,
3584 "cast increases required alignment of target type");
3585
3586 if (TREE_CODE (type) == INTEGER_TYPE
3587 && TREE_CODE (otype) == POINTER_TYPE
3588 && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
3589 /* Unlike conversion of integers to pointers, where the
3590 warning is disabled for converting constants because
3591 of cases such as SIG_*, warn about converting constant
3592 pointers to integers. In some cases it may cause unwanted
3593 sign extension, and a warning is appropriate. */
3594 warning (OPT_Wpointer_to_int_cast,
3595 "cast from pointer to integer of different size");
3596
3597 if (TREE_CODE (value) == CALL_EXPR
3598 && TREE_CODE (type) != TREE_CODE (otype))
3599 warning (OPT_Wbad_function_cast, "cast from function call of type %qT "
3600 "to non-matching type %qT", otype, type);
3601
3602 if (TREE_CODE (type) == POINTER_TYPE
3603 && TREE_CODE (otype) == INTEGER_TYPE
3604 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3605 /* Don't warn about converting any constant. */
3606 && !TREE_CONSTANT (value))
3607 warning (OPT_Wint_to_pointer_cast, "cast to pointer from integer "
3608 "of different size");
3609
3610 if (warn_strict_aliasing <= 2)
3611 strict_aliasing_warning (otype, type, expr);
3612
3613 /* If pedantic, warn for conversions between function and object
3614 pointer types, except for converting a null pointer constant
3615 to function pointer type. */
3616 if (pedantic
3617 && TREE_CODE (type) == POINTER_TYPE
3618 && TREE_CODE (otype) == POINTER_TYPE
3619 && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE
3620 && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE)
3621 pedwarn ("ISO C forbids conversion of function pointer to object pointer type");
3622
3623 if (pedantic
3624 && TREE_CODE (type) == POINTER_TYPE
3625 && TREE_CODE (otype) == POINTER_TYPE
3626 && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE
3627 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3628 && !null_pointer_constant_p (value))
3629 pedwarn ("ISO C forbids conversion of object pointer to function pointer type");
3630
3631 ovalue = value;
3632 value = convert (type, value);
3633
3634 /* Ignore any integer overflow caused by the cast. */
3635 if (TREE_CODE (value) == INTEGER_CST)
3636 {
3637 if (CONSTANT_CLASS_P (ovalue) && TREE_OVERFLOW (ovalue))
3638 {
3639 if (!TREE_OVERFLOW (value))
3640 {
3641 /* Avoid clobbering a shared constant. */
3642 value = copy_node (value);
3643 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3644 }
3645 }
3646 else if (TREE_OVERFLOW (value))
3647 /* Reset VALUE's overflow flags, ensuring constant sharing. */
3648 value = build_int_cst_wide (TREE_TYPE (value),
3649 TREE_INT_CST_LOW (value),
3650 TREE_INT_CST_HIGH (value));
3651 }
3652 }
3653
3654 /* Don't let a cast be an lvalue. */
3655 if (value == expr)
3656 value = non_lvalue (value);
3657
3658 return value;
3659 }
3660
3661 /* Interpret a cast of expression EXPR to type TYPE. */
3662 tree
3663 c_cast_expr (struct c_type_name *type_name, tree expr)
3664 {
3665 tree type;
3666 int saved_wsp = warn_strict_prototypes;
3667
3668 /* This avoids warnings about unprototyped casts on
3669 integers. E.g. "#define SIG_DFL (void(*)())0". */
3670 if (TREE_CODE (expr) == INTEGER_CST)
3671 warn_strict_prototypes = 0;
3672 type = groktypename (type_name);
3673 warn_strict_prototypes = saved_wsp;
3674
3675 return build_c_cast (type, expr);
3676 }
3677 \f
3678 /* Build an assignment expression of lvalue LHS from value RHS.
3679 MODIFYCODE is the code for a binary operator that we use
3680 to combine the old value of LHS with RHS to get the new value.
3681 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3682
3683 tree
3684 build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs)
3685 {
3686 tree result;
3687 tree newrhs;
3688 tree lhstype = TREE_TYPE (lhs);
3689 tree olhstype = lhstype;
3690
3691 /* Types that aren't fully specified cannot be used in assignments. */
3692 lhs = require_complete_type (lhs);
3693
3694 /* Avoid duplicate error messages from operands that had errors. */
3695 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3696 return error_mark_node;
3697
3698 if (!lvalue_or_else (lhs, lv_assign))
3699 return error_mark_node;
3700
3701 STRIP_TYPE_NOPS (rhs);
3702
3703 newrhs = rhs;
3704
3705 /* If a binary op has been requested, combine the old LHS value with the RHS
3706 producing the value we should actually store into the LHS. */
3707
3708 if (modifycode != NOP_EXPR)
3709 {
3710 lhs = stabilize_reference (lhs);
3711 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3712 }
3713
3714 /* Give an error for storing in something that is 'const'. */
3715
3716 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3717 || ((TREE_CODE (lhstype) == RECORD_TYPE
3718 || TREE_CODE (lhstype) == UNION_TYPE)
3719 && C_TYPE_FIELDS_READONLY (lhstype)))
3720 {
3721 readonly_error (lhs, lv_assign);
3722 return error_mark_node;
3723 }
3724
3725 /* If storing into a structure or union member,
3726 it has probably been given type `int'.
3727 Compute the type that would go with
3728 the actual amount of storage the member occupies. */
3729
3730 if (TREE_CODE (lhs) == COMPONENT_REF
3731 && (TREE_CODE (lhstype) == INTEGER_TYPE
3732 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3733 || TREE_CODE (lhstype) == REAL_TYPE
3734 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3735 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3736
3737 /* If storing in a field that is in actuality a short or narrower than one,
3738 we must store in the field in its actual type. */
3739
3740 if (lhstype != TREE_TYPE (lhs))
3741 {
3742 lhs = copy_node (lhs);
3743 TREE_TYPE (lhs) = lhstype;
3744 }
3745
3746 /* Convert new value to destination type. */
3747
3748 newrhs = convert_for_assignment (lhstype, newrhs, ic_assign,
3749 NULL_TREE, NULL_TREE, 0);
3750 if (TREE_CODE (newrhs) == ERROR_MARK)
3751 return error_mark_node;
3752
3753 /* Emit ObjC write barrier, if necessary. */
3754 if (c_dialect_objc () && flag_objc_gc)
3755 {
3756 result = objc_generate_write_barrier (lhs, modifycode, newrhs);
3757 if (result)
3758 return result;
3759 }
3760
3761 /* Scan operands. */
3762
3763 result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs);
3764 TREE_SIDE_EFFECTS (result) = 1;
3765
3766 /* If we got the LHS in a different type for storing in,
3767 convert the result back to the nominal type of LHS
3768 so that the value we return always has the same type
3769 as the LHS argument. */
3770
3771 if (olhstype == TREE_TYPE (result))
3772 return result;
3773 return convert_for_assignment (olhstype, result, ic_assign,
3774 NULL_TREE, NULL_TREE, 0);
3775 }
3776 \f
3777 /* Convert value RHS to type TYPE as preparation for an assignment
3778 to an lvalue of type TYPE.
3779 The real work of conversion is done by `convert'.
3780 The purpose of this function is to generate error messages
3781 for assignments that are not allowed in C.
3782 ERRTYPE says whether it is argument passing, assignment,
3783 initialization or return.
3784
3785 FUNCTION is a tree for the function being called.
3786 PARMNUM is the number of the argument, for printing in error messages. */
3787
3788 static tree
3789 convert_for_assignment (tree type, tree rhs, enum impl_conv errtype,
3790 tree fundecl, tree function, int parmnum)
3791 {
3792 enum tree_code codel = TREE_CODE (type);
3793 tree rhstype;
3794 enum tree_code coder;
3795 tree rname = NULL_TREE;
3796 bool objc_ok = false;
3797
3798 if (errtype == ic_argpass || errtype == ic_argpass_nonproto)
3799 {
3800 tree selector;
3801 /* Change pointer to function to the function itself for
3802 diagnostics. */
3803 if (TREE_CODE (function) == ADDR_EXPR
3804 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
3805 function = TREE_OPERAND (function, 0);
3806
3807 /* Handle an ObjC selector specially for diagnostics. */
3808 selector = objc_message_selector ();
3809 rname = function;
3810 if (selector && parmnum > 2)
3811 {
3812 rname = selector;
3813 parmnum -= 2;
3814 }
3815 }
3816
3817 /* This macro is used to emit diagnostics to ensure that all format
3818 strings are complete sentences, visible to gettext and checked at
3819 compile time. */
3820 #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \
3821 do { \
3822 switch (errtype) \
3823 { \
3824 case ic_argpass: \
3825 pedwarn (AR, parmnum, rname); \
3826 break; \
3827 case ic_argpass_nonproto: \
3828 warning (0, AR, parmnum, rname); \
3829 break; \
3830 case ic_assign: \
3831 pedwarn (AS); \
3832 break; \
3833 case ic_init: \
3834 pedwarn (IN); \
3835 break; \
3836 case ic_return: \
3837 pedwarn (RE); \
3838 break; \
3839 default: \
3840 gcc_unreachable (); \
3841 } \
3842 } while (0)
3843
3844 STRIP_TYPE_NOPS (rhs);
3845
3846 if (optimize && TREE_CODE (rhs) == VAR_DECL
3847 && TREE_CODE (TREE_TYPE (rhs)) != ARRAY_TYPE)
3848 rhs = decl_constant_value_for_broken_optimization (rhs);
3849
3850 rhstype = TREE_TYPE (rhs);
3851 coder = TREE_CODE (rhstype);
3852
3853 if (coder == ERROR_MARK)
3854 return error_mark_node;
3855
3856 if (c_dialect_objc ())
3857 {
3858 int parmno;
3859
3860 switch (errtype)
3861 {
3862 case ic_return:
3863 parmno = 0;
3864 break;
3865
3866 case ic_assign:
3867 parmno = -1;
3868 break;
3869
3870 case ic_init:
3871 parmno = -2;
3872 break;
3873
3874 default:
3875 parmno = parmnum;
3876 break;
3877 }
3878
3879 objc_ok = objc_compare_types (type, rhstype, parmno, rname);
3880 }
3881
3882 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
3883 return rhs;
3884
3885 if (coder == VOID_TYPE)
3886 {
3887 /* Except for passing an argument to an unprototyped function,
3888 this is a constraint violation. When passing an argument to
3889 an unprototyped function, it is compile-time undefined;
3890 making it a constraint in that case was rejected in
3891 DR#252. */
3892 error ("void value not ignored as it ought to be");
3893 return error_mark_node;
3894 }
3895 /* A type converts to a reference to it.
3896 This code doesn't fully support references, it's just for the
3897 special case of va_start and va_copy. */
3898 if (codel == REFERENCE_TYPE
3899 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
3900 {
3901 if (!lvalue_p (rhs))
3902 {
3903 error ("cannot pass rvalue to reference parameter");
3904 return error_mark_node;
3905 }
3906 if (!c_mark_addressable (rhs))
3907 return error_mark_node;
3908 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
3909
3910 /* We already know that these two types are compatible, but they
3911 may not be exactly identical. In fact, `TREE_TYPE (type)' is
3912 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
3913 likely to be va_list, a typedef to __builtin_va_list, which
3914 is different enough that it will cause problems later. */
3915 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
3916 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
3917
3918 rhs = build1 (NOP_EXPR, type, rhs);
3919 return rhs;
3920 }
3921 /* Some types can interconvert without explicit casts. */
3922 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
3923 && vector_types_convertible_p (type, TREE_TYPE (rhs), true))
3924 return convert (type, rhs);
3925 /* Arithmetic types all interconvert, and enum is treated like int. */
3926 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
3927 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
3928 || codel == BOOLEAN_TYPE)
3929 && (coder == INTEGER_TYPE || coder == REAL_TYPE
3930 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
3931 || coder == BOOLEAN_TYPE))
3932 return convert_and_check (type, rhs);
3933
3934 /* Aggregates in different TUs might need conversion. */
3935 if ((codel == RECORD_TYPE || codel == UNION_TYPE)
3936 && codel == coder
3937 && comptypes (type, rhstype))
3938 return convert_and_check (type, rhs);
3939
3940 /* Conversion to a transparent union from its member types.
3941 This applies only to function arguments. */
3942 if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type)
3943 && (errtype == ic_argpass || errtype == ic_argpass_nonproto))
3944 {
3945 tree memb, marginal_memb = NULL_TREE;
3946
3947 for (memb = TYPE_FIELDS (type); memb ; memb = TREE_CHAIN (memb))
3948 {
3949 tree memb_type = TREE_TYPE (memb);
3950
3951 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
3952 TYPE_MAIN_VARIANT (rhstype)))
3953 break;
3954
3955 if (TREE_CODE (memb_type) != POINTER_TYPE)
3956 continue;
3957
3958 if (coder == POINTER_TYPE)
3959 {
3960 tree ttl = TREE_TYPE (memb_type);
3961 tree ttr = TREE_TYPE (rhstype);
3962
3963 /* Any non-function converts to a [const][volatile] void *
3964 and vice versa; otherwise, targets must be the same.
3965 Meanwhile, the lhs target must have all the qualifiers of
3966 the rhs. */
3967 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
3968 || comp_target_types (memb_type, rhstype))
3969 {
3970 /* If this type won't generate any warnings, use it. */
3971 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
3972 || ((TREE_CODE (ttr) == FUNCTION_TYPE
3973 && TREE_CODE (ttl) == FUNCTION_TYPE)
3974 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3975 == TYPE_QUALS (ttr))
3976 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
3977 == TYPE_QUALS (ttl))))
3978 break;
3979
3980 /* Keep looking for a better type, but remember this one. */
3981 if (!marginal_memb)
3982 marginal_memb = memb;
3983 }
3984 }
3985
3986 /* Can convert integer zero to any pointer type. */
3987 if (null_pointer_constant_p (rhs))
3988 {
3989 rhs = null_pointer_node;
3990 break;
3991 }
3992 }
3993
3994 if (memb || marginal_memb)
3995 {
3996 if (!memb)
3997 {
3998 /* We have only a marginally acceptable member type;
3999 it needs a warning. */
4000 tree ttl = TREE_TYPE (TREE_TYPE (marginal_memb));
4001 tree ttr = TREE_TYPE (rhstype);
4002
4003 /* Const and volatile mean something different for function
4004 types, so the usual warnings are not appropriate. */
4005 if (TREE_CODE (ttr) == FUNCTION_TYPE
4006 && TREE_CODE (ttl) == FUNCTION_TYPE)
4007 {
4008 /* Because const and volatile on functions are
4009 restrictions that say the function will not do
4010 certain things, it is okay to use a const or volatile
4011 function where an ordinary one is wanted, but not
4012 vice-versa. */
4013 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4014 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE "
4015 "makes qualified function "
4016 "pointer from unqualified"),
4017 G_("assignment makes qualified "
4018 "function pointer from "
4019 "unqualified"),
4020 G_("initialization makes qualified "
4021 "function pointer from "
4022 "unqualified"),
4023 G_("return makes qualified function "
4024 "pointer from unqualified"));
4025 }
4026 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4027 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4028 "qualifiers from pointer target type"),
4029 G_("assignment discards qualifiers "
4030 "from pointer target type"),
4031 G_("initialization discards qualifiers "
4032 "from pointer target type"),
4033 G_("return discards qualifiers from "
4034 "pointer target type"));
4035
4036 memb = marginal_memb;
4037 }
4038
4039 if (pedantic && (!fundecl || !DECL_IN_SYSTEM_HEADER (fundecl)))
4040 pedwarn ("ISO C prohibits argument conversion to union type");
4041
4042 return build_constructor_single (type, memb, rhs);
4043 }
4044 }
4045
4046 /* Conversions among pointers */
4047 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4048 && (coder == codel))
4049 {
4050 tree ttl = TREE_TYPE (type);
4051 tree ttr = TREE_TYPE (rhstype);
4052 tree mvl = ttl;
4053 tree mvr = ttr;
4054 bool is_opaque_pointer;
4055 int target_cmp = 0; /* Cache comp_target_types () result. */
4056
4057 if (TREE_CODE (mvl) != ARRAY_TYPE)
4058 mvl = TYPE_MAIN_VARIANT (mvl);
4059 if (TREE_CODE (mvr) != ARRAY_TYPE)
4060 mvr = TYPE_MAIN_VARIANT (mvr);
4061 /* Opaque pointers are treated like void pointers. */
4062 is_opaque_pointer = (targetm.vector_opaque_p (type)
4063 || targetm.vector_opaque_p (rhstype))
4064 && TREE_CODE (ttl) == VECTOR_TYPE
4065 && TREE_CODE (ttr) == VECTOR_TYPE;
4066
4067 /* C++ does not allow the implicit conversion void* -> T*. However,
4068 for the purpose of reducing the number of false positives, we
4069 tolerate the special case of
4070
4071 int *p = NULL;
4072
4073 where NULL is typically defined in C to be '(void *) 0'. */
4074 if (VOID_TYPE_P (ttr) && rhs != null_pointer_node && !VOID_TYPE_P (ttl))
4075 warning (OPT_Wc___compat, "request for implicit conversion from "
4076 "%qT to %qT not permitted in C++", rhstype, type);
4077
4078 /* Check if the right-hand side has a format attribute but the
4079 left-hand side doesn't. */
4080 if (warn_missing_format_attribute
4081 && check_missing_format_attribute (type, rhstype))
4082 {
4083 switch (errtype)
4084 {
4085 case ic_argpass:
4086 case ic_argpass_nonproto:
4087 warning (OPT_Wmissing_format_attribute,
4088 "argument %d of %qE might be "
4089 "a candidate for a format attribute",
4090 parmnum, rname);
4091 break;
4092 case ic_assign:
4093 warning (OPT_Wmissing_format_attribute,
4094 "assignment left-hand side might be "
4095 "a candidate for a format attribute");
4096 break;
4097 case ic_init:
4098 warning (OPT_Wmissing_format_attribute,
4099 "initialization left-hand side might be "
4100 "a candidate for a format attribute");
4101 break;
4102 case ic_return:
4103 warning (OPT_Wmissing_format_attribute,
4104 "return type might be "
4105 "a candidate for a format attribute");
4106 break;
4107 default:
4108 gcc_unreachable ();
4109 }
4110 }
4111
4112 /* Any non-function converts to a [const][volatile] void *
4113 and vice versa; otherwise, targets must be the same.
4114 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4115 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4116 || (target_cmp = comp_target_types (type, rhstype))
4117 || is_opaque_pointer
4118 || (c_common_unsigned_type (mvl)
4119 == c_common_unsigned_type (mvr)))
4120 {
4121 if (pedantic
4122 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4123 ||
4124 (VOID_TYPE_P (ttr)
4125 && !null_pointer_constant_p (rhs)
4126 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4127 WARN_FOR_ASSIGNMENT (G_("ISO C forbids passing argument %d of "
4128 "%qE between function pointer "
4129 "and %<void *%>"),
4130 G_("ISO C forbids assignment between "
4131 "function pointer and %<void *%>"),
4132 G_("ISO C forbids initialization between "
4133 "function pointer and %<void *%>"),
4134 G_("ISO C forbids return between function "
4135 "pointer and %<void *%>"));
4136 /* Const and volatile mean something different for function types,
4137 so the usual warnings are not appropriate. */
4138 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4139 && TREE_CODE (ttl) != FUNCTION_TYPE)
4140 {
4141 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4142 {
4143 /* Types differing only by the presence of the 'volatile'
4144 qualifier are acceptable if the 'volatile' has been added
4145 in by the Objective-C EH machinery. */
4146 if (!objc_type_quals_match (ttl, ttr))
4147 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE discards "
4148 "qualifiers from pointer target type"),
4149 G_("assignment discards qualifiers "
4150 "from pointer target type"),
4151 G_("initialization discards qualifiers "
4152 "from pointer target type"),
4153 G_("return discards qualifiers from "
4154 "pointer target type"));
4155 }
4156 /* If this is not a case of ignoring a mismatch in signedness,
4157 no warning. */
4158 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4159 || target_cmp)
4160 ;
4161 /* If there is a mismatch, do warn. */
4162 else if (warn_pointer_sign)
4163 WARN_FOR_ASSIGNMENT (G_("pointer targets in passing argument "
4164 "%d of %qE differ in signedness"),
4165 G_("pointer targets in assignment "
4166 "differ in signedness"),
4167 G_("pointer targets in initialization "
4168 "differ in signedness"),
4169 G_("pointer targets in return differ "
4170 "in signedness"));
4171 }
4172 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4173 && TREE_CODE (ttr) == FUNCTION_TYPE)
4174 {
4175 /* Because const and volatile on functions are restrictions
4176 that say the function will not do certain things,
4177 it is okay to use a const or volatile function
4178 where an ordinary one is wanted, but not vice-versa. */
4179 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4180 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4181 "qualified function pointer "
4182 "from unqualified"),
4183 G_("assignment makes qualified function "
4184 "pointer from unqualified"),
4185 G_("initialization makes qualified "
4186 "function pointer from unqualified"),
4187 G_("return makes qualified function "
4188 "pointer from unqualified"));
4189 }
4190 }
4191 else
4192 /* Avoid warning about the volatile ObjC EH puts on decls. */
4193 if (!objc_ok)
4194 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE from "
4195 "incompatible pointer type"),
4196 G_("assignment from incompatible pointer type"),
4197 G_("initialization from incompatible "
4198 "pointer type"),
4199 G_("return from incompatible pointer type"));
4200
4201 return convert (type, rhs);
4202 }
4203 else if (codel == POINTER_TYPE && coder == ARRAY_TYPE)
4204 {
4205 /* ??? This should not be an error when inlining calls to
4206 unprototyped functions. */
4207 error ("invalid use of non-lvalue array");
4208 return error_mark_node;
4209 }
4210 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4211 {
4212 /* An explicit constant 0 can convert to a pointer,
4213 or one that results from arithmetic, even including
4214 a cast to integer type. */
4215 if (!null_pointer_constant_p (rhs))
4216 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes "
4217 "pointer from integer without a cast"),
4218 G_("assignment makes pointer from integer "
4219 "without a cast"),
4220 G_("initialization makes pointer from "
4221 "integer without a cast"),
4222 G_("return makes pointer from integer "
4223 "without a cast"));
4224
4225 return convert (type, rhs);
4226 }
4227 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4228 {
4229 WARN_FOR_ASSIGNMENT (G_("passing argument %d of %qE makes integer "
4230 "from pointer without a cast"),
4231 G_("assignment makes integer from pointer "
4232 "without a cast"),
4233 G_("initialization makes integer from pointer "
4234 "without a cast"),
4235 G_("return makes integer from pointer "
4236 "without a cast"));
4237 return convert (type, rhs);
4238 }
4239 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4240 return convert (type, rhs);
4241
4242 switch (errtype)
4243 {
4244 case ic_argpass:
4245 case ic_argpass_nonproto:
4246 /* ??? This should not be an error when inlining calls to
4247 unprototyped functions. */
4248 error ("incompatible type for argument %d of %qE", parmnum, rname);
4249 break;
4250 case ic_assign:
4251 error ("incompatible types in assignment");
4252 break;
4253 case ic_init:
4254 error ("incompatible types in initialization");
4255 break;
4256 case ic_return:
4257 error ("incompatible types in return");
4258 break;
4259 default:
4260 gcc_unreachable ();
4261 }
4262
4263 return error_mark_node;
4264 }
4265 \f
4266 /* If VALUE is a compound expr all of whose expressions are constant, then
4267 return its value. Otherwise, return error_mark_node.
4268
4269 This is for handling COMPOUND_EXPRs as initializer elements
4270 which is allowed with a warning when -pedantic is specified. */
4271
4272 static tree
4273 valid_compound_expr_initializer (tree value, tree endtype)
4274 {
4275 if (TREE_CODE (value) == COMPOUND_EXPR)
4276 {
4277 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4278 == error_mark_node)
4279 return error_mark_node;
4280 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4281 endtype);
4282 }
4283 else if (!initializer_constant_valid_p (value, endtype))
4284 return error_mark_node;
4285 else
4286 return value;
4287 }
4288 \f
4289 /* Perform appropriate conversions on the initial value of a variable,
4290 store it in the declaration DECL,
4291 and print any error messages that are appropriate.
4292 If the init is invalid, store an ERROR_MARK. */
4293
4294 void
4295 store_init_value (tree decl, tree init)
4296 {
4297 tree value, type;
4298
4299 /* If variable's type was invalidly declared, just ignore it. */
4300
4301 type = TREE_TYPE (decl);
4302 if (TREE_CODE (type) == ERROR_MARK)
4303 return;
4304
4305 /* Digest the specified initializer into an expression. */
4306
4307 value = digest_init (type, init, true, TREE_STATIC (decl));
4308
4309 /* Store the expression if valid; else report error. */
4310
4311 if (!in_system_header
4312 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl))
4313 warning (OPT_Wtraditional, "traditional C rejects automatic "
4314 "aggregate initialization");
4315
4316 DECL_INITIAL (decl) = value;
4317
4318 /* ANSI wants warnings about out-of-range constant initializers. */
4319 STRIP_TYPE_NOPS (value);
4320 if (TREE_STATIC (decl))
4321 constant_expression_warning (value);
4322
4323 /* Check if we need to set array size from compound literal size. */
4324 if (TREE_CODE (type) == ARRAY_TYPE
4325 && TYPE_DOMAIN (type) == 0
4326 && value != error_mark_node)
4327 {
4328 tree inside_init = init;
4329
4330 STRIP_TYPE_NOPS (inside_init);
4331 inside_init = fold (inside_init);
4332
4333 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4334 {
4335 tree cldecl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4336
4337 if (TYPE_DOMAIN (TREE_TYPE (cldecl)))
4338 {
4339 /* For int foo[] = (int [3]){1}; we need to set array size
4340 now since later on array initializer will be just the
4341 brace enclosed list of the compound literal. */
4342 type = build_distinct_type_copy (TYPE_MAIN_VARIANT (type));
4343 TREE_TYPE (decl) = type;
4344 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (cldecl));
4345 layout_type (type);
4346 layout_decl (cldecl, 0);
4347 }
4348 }
4349 }
4350 }
4351 \f
4352 /* Methods for storing and printing names for error messages. */
4353
4354 /* Implement a spelling stack that allows components of a name to be pushed
4355 and popped. Each element on the stack is this structure. */
4356
4357 struct spelling
4358 {
4359 int kind;
4360 union
4361 {
4362 unsigned HOST_WIDE_INT i;
4363 const char *s;
4364 } u;
4365 };
4366
4367 #define SPELLING_STRING 1
4368 #define SPELLING_MEMBER 2
4369 #define SPELLING_BOUNDS 3
4370
4371 static struct spelling *spelling; /* Next stack element (unused). */
4372 static struct spelling *spelling_base; /* Spelling stack base. */
4373 static int spelling_size; /* Size of the spelling stack. */
4374
4375 /* Macros to save and restore the spelling stack around push_... functions.
4376 Alternative to SAVE_SPELLING_STACK. */
4377
4378 #define SPELLING_DEPTH() (spelling - spelling_base)
4379 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4380
4381 /* Push an element on the spelling stack with type KIND and assign VALUE
4382 to MEMBER. */
4383
4384 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4385 { \
4386 int depth = SPELLING_DEPTH (); \
4387 \
4388 if (depth >= spelling_size) \
4389 { \
4390 spelling_size += 10; \
4391 spelling_base = XRESIZEVEC (struct spelling, spelling_base, \
4392 spelling_size); \
4393 RESTORE_SPELLING_DEPTH (depth); \
4394 } \
4395 \
4396 spelling->kind = (KIND); \
4397 spelling->MEMBER = (VALUE); \
4398 spelling++; \
4399 }
4400
4401 /* Push STRING on the stack. Printed literally. */
4402
4403 static void
4404 push_string (const char *string)
4405 {
4406 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4407 }
4408
4409 /* Push a member name on the stack. Printed as '.' STRING. */
4410
4411 static void
4412 push_member_name (tree decl)
4413 {
4414 const char *const string
4415 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4416 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4417 }
4418
4419 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4420
4421 static void
4422 push_array_bounds (unsigned HOST_WIDE_INT bounds)
4423 {
4424 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4425 }
4426
4427 /* Compute the maximum size in bytes of the printed spelling. */
4428
4429 static int
4430 spelling_length (void)
4431 {
4432 int size = 0;
4433 struct spelling *p;
4434
4435 for (p = spelling_base; p < spelling; p++)
4436 {
4437 if (p->kind == SPELLING_BOUNDS)
4438 size += 25;
4439 else
4440 size += strlen (p->u.s) + 1;
4441 }
4442
4443 return size;
4444 }
4445
4446 /* Print the spelling to BUFFER and return it. */
4447
4448 static char *
4449 print_spelling (char *buffer)
4450 {
4451 char *d = buffer;
4452 struct spelling *p;
4453
4454 for (p = spelling_base; p < spelling; p++)
4455 if (p->kind == SPELLING_BOUNDS)
4456 {
4457 sprintf (d, "[" HOST_WIDE_INT_PRINT_UNSIGNED "]", p->u.i);
4458 d += strlen (d);
4459 }
4460 else
4461 {
4462 const char *s;
4463 if (p->kind == SPELLING_MEMBER)
4464 *d++ = '.';
4465 for (s = p->u.s; (*d = *s++); d++)
4466 ;
4467 }
4468 *d++ = '\0';
4469 return buffer;
4470 }
4471
4472 /* Issue an error message for a bad initializer component.
4473 MSGID identifies the message.
4474 The component name is taken from the spelling stack. */
4475
4476 void
4477 error_init (const char *msgid)
4478 {
4479 char *ofwhat;
4480
4481 error ("%s", _(msgid));
4482 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4483 if (*ofwhat)
4484 error ("(near initialization for %qs)", ofwhat);
4485 }
4486
4487 /* Issue a pedantic warning for a bad initializer component.
4488 MSGID identifies the message.
4489 The component name is taken from the spelling stack. */
4490
4491 void
4492 pedwarn_init (const char *msgid)
4493 {
4494 char *ofwhat;
4495
4496 pedwarn ("%s", _(msgid));
4497 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4498 if (*ofwhat)
4499 pedwarn ("(near initialization for %qs)", ofwhat);
4500 }
4501
4502 /* Issue a warning for a bad initializer component.
4503 MSGID identifies the message.
4504 The component name is taken from the spelling stack. */
4505
4506 static void
4507 warning_init (const char *msgid)
4508 {
4509 char *ofwhat;
4510
4511 warning (0, "%s", _(msgid));
4512 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4513 if (*ofwhat)
4514 warning (0, "(near initialization for %qs)", ofwhat);
4515 }
4516 \f
4517 /* If TYPE is an array type and EXPR is a parenthesized string
4518 constant, warn if pedantic that EXPR is being used to initialize an
4519 object of type TYPE. */
4520
4521 void
4522 maybe_warn_string_init (tree type, struct c_expr expr)
4523 {
4524 if (pedantic
4525 && TREE_CODE (type) == ARRAY_TYPE
4526 && TREE_CODE (expr.value) == STRING_CST
4527 && expr.original_code != STRING_CST)
4528 pedwarn_init ("array initialized from parenthesized string constant");
4529 }
4530
4531 /* Digest the parser output INIT as an initializer for type TYPE.
4532 Return a C expression of type TYPE to represent the initial value.
4533
4534 If INIT is a string constant, STRICT_STRING is true if it is
4535 unparenthesized or we should not warn here for it being parenthesized.
4536 For other types of INIT, STRICT_STRING is not used.
4537
4538 REQUIRE_CONSTANT requests an error if non-constant initializers or
4539 elements are seen. */
4540
4541 static tree
4542 digest_init (tree type, tree init, bool strict_string, int require_constant)
4543 {
4544 enum tree_code code = TREE_CODE (type);
4545 tree inside_init = init;
4546
4547 if (type == error_mark_node
4548 || !init
4549 || init == error_mark_node
4550 || TREE_TYPE (init) == error_mark_node)
4551 return error_mark_node;
4552
4553 STRIP_TYPE_NOPS (inside_init);
4554
4555 inside_init = fold (inside_init);
4556
4557 /* Initialization of an array of chars from a string constant
4558 optionally enclosed in braces. */
4559
4560 if (code == ARRAY_TYPE && inside_init
4561 && TREE_CODE (inside_init) == STRING_CST)
4562 {
4563 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4564 /* Note that an array could be both an array of character type
4565 and an array of wchar_t if wchar_t is signed char or unsigned
4566 char. */
4567 bool char_array = (typ1 == char_type_node
4568 || typ1 == signed_char_type_node
4569 || typ1 == unsigned_char_type_node);
4570 bool wchar_array = !!comptypes (typ1, wchar_type_node);
4571 if (char_array || wchar_array)
4572 {
4573 struct c_expr expr;
4574 bool char_string;
4575 expr.value = inside_init;
4576 expr.original_code = (strict_string ? STRING_CST : ERROR_MARK);
4577 maybe_warn_string_init (type, expr);
4578
4579 char_string
4580 = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4581 == char_type_node);
4582
4583 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4584 TYPE_MAIN_VARIANT (type)))
4585 return inside_init;
4586
4587 if (!wchar_array && !char_string)
4588 {
4589 error_init ("char-array initialized from wide string");
4590 return error_mark_node;
4591 }
4592 if (char_string && !char_array)
4593 {
4594 error_init ("wchar_t-array initialized from non-wide string");
4595 return error_mark_node;
4596 }
4597
4598 TREE_TYPE (inside_init) = type;
4599 if (TYPE_DOMAIN (type) != 0
4600 && TYPE_SIZE (type) != 0
4601 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4602 /* Subtract 1 (or sizeof (wchar_t))
4603 because it's ok to ignore the terminating null char
4604 that is counted in the length of the constant. */
4605 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4606 TREE_STRING_LENGTH (inside_init)
4607 - ((TYPE_PRECISION (typ1)
4608 != TYPE_PRECISION (char_type_node))
4609 ? (TYPE_PRECISION (wchar_type_node)
4610 / BITS_PER_UNIT)
4611 : 1)))
4612 pedwarn_init ("initializer-string for array of chars is too long");
4613
4614 return inside_init;
4615 }
4616 else if (INTEGRAL_TYPE_P (typ1))
4617 {
4618 error_init ("array of inappropriate type initialized "
4619 "from string constant");
4620 return error_mark_node;
4621 }
4622 }
4623
4624 /* Build a VECTOR_CST from a *constant* vector constructor. If the
4625 vector constructor is not constant (e.g. {1,2,3,foo()}) then punt
4626 below and handle as a constructor. */
4627 if (code == VECTOR_TYPE
4628 && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE
4629 && vector_types_convertible_p (TREE_TYPE (inside_init), type, true)
4630 && TREE_CONSTANT (inside_init))
4631 {
4632 if (TREE_CODE (inside_init) == VECTOR_CST
4633 && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4634 TYPE_MAIN_VARIANT (type)))
4635 return inside_init;
4636
4637 if (TREE_CODE (inside_init) == CONSTRUCTOR)
4638 {
4639 unsigned HOST_WIDE_INT ix;
4640 tree value;
4641 bool constant_p = true;
4642
4643 /* Iterate through elements and check if all constructor
4644 elements are *_CSTs. */
4645 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (inside_init), ix, value)
4646 if (!CONSTANT_CLASS_P (value))
4647 {
4648 constant_p = false;
4649 break;
4650 }
4651
4652 if (constant_p)
4653 return build_vector_from_ctor (type,
4654 CONSTRUCTOR_ELTS (inside_init));
4655 }
4656 }
4657
4658 /* Any type can be initialized
4659 from an expression of the same type, optionally with braces. */
4660
4661 if (inside_init && TREE_TYPE (inside_init) != 0
4662 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4663 TYPE_MAIN_VARIANT (type))
4664 || (code == ARRAY_TYPE
4665 && comptypes (TREE_TYPE (inside_init), type))
4666 || (code == VECTOR_TYPE
4667 && comptypes (TREE_TYPE (inside_init), type))
4668 || (code == POINTER_TYPE
4669 && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4670 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4671 TREE_TYPE (type)))))
4672 {
4673 if (code == POINTER_TYPE)
4674 {
4675 if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE)
4676 {
4677 if (TREE_CODE (inside_init) == STRING_CST
4678 || TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4679 inside_init = array_to_pointer_conversion (inside_init);
4680 else
4681 {
4682 error_init ("invalid use of non-lvalue array");
4683 return error_mark_node;
4684 }
4685 }
4686 }
4687
4688 if (code == VECTOR_TYPE)
4689 /* Although the types are compatible, we may require a
4690 conversion. */
4691 inside_init = convert (type, inside_init);
4692
4693 if (require_constant
4694 && (code == VECTOR_TYPE || !flag_isoc99)
4695 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4696 {
4697 /* As an extension, allow initializing objects with static storage
4698 duration with compound literals (which are then treated just as
4699 the brace enclosed list they contain). Also allow this for
4700 vectors, as we can only assign them with compound literals. */
4701 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4702 inside_init = DECL_INITIAL (decl);
4703 }
4704
4705 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4706 && TREE_CODE (inside_init) != CONSTRUCTOR)
4707 {
4708 error_init ("array initialized from non-constant array expression");
4709 return error_mark_node;
4710 }
4711
4712 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4713 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4714
4715 /* Compound expressions can only occur here if -pedantic or
4716 -pedantic-errors is specified. In the later case, we always want
4717 an error. In the former case, we simply want a warning. */
4718 if (require_constant && pedantic
4719 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4720 {
4721 inside_init
4722 = valid_compound_expr_initializer (inside_init,
4723 TREE_TYPE (inside_init));
4724 if (inside_init == error_mark_node)
4725 error_init ("initializer element is not constant");
4726 else
4727 pedwarn_init ("initializer element is not constant");
4728 if (flag_pedantic_errors)
4729 inside_init = error_mark_node;
4730 }
4731 else if (require_constant
4732 && !initializer_constant_valid_p (inside_init,
4733 TREE_TYPE (inside_init)))
4734 {
4735 error_init ("initializer element is not constant");
4736 inside_init = error_mark_node;
4737 }
4738
4739 /* Added to enable additional -Wmissing-format-attribute warnings. */
4740 if (TREE_CODE (TREE_TYPE (inside_init)) == POINTER_TYPE)
4741 inside_init = convert_for_assignment (type, inside_init, ic_init, NULL_TREE,
4742 NULL_TREE, 0);
4743 return inside_init;
4744 }
4745
4746 /* Handle scalar types, including conversions. */
4747
4748 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4749 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE
4750 || code == VECTOR_TYPE)
4751 {
4752 if (TREE_CODE (TREE_TYPE (init)) == ARRAY_TYPE
4753 && (TREE_CODE (init) == STRING_CST
4754 || TREE_CODE (init) == COMPOUND_LITERAL_EXPR))
4755 init = array_to_pointer_conversion (init);
4756 inside_init
4757 = convert_for_assignment (type, init, ic_init,
4758 NULL_TREE, NULL_TREE, 0);
4759
4760 /* Check to see if we have already given an error message. */
4761 if (inside_init == error_mark_node)
4762 ;
4763 else if (require_constant && !TREE_CONSTANT (inside_init))
4764 {
4765 error_init ("initializer element is not constant");
4766 inside_init = error_mark_node;
4767 }
4768 else if (require_constant
4769 && !initializer_constant_valid_p (inside_init,
4770 TREE_TYPE (inside_init)))
4771 {
4772 error_init ("initializer element is not computable at load time");
4773 inside_init = error_mark_node;
4774 }
4775
4776 return inside_init;
4777 }
4778
4779 /* Come here only for records and arrays. */
4780
4781 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4782 {
4783 error_init ("variable-sized object may not be initialized");
4784 return error_mark_node;
4785 }
4786
4787 error_init ("invalid initializer");
4788 return error_mark_node;
4789 }
4790 \f
4791 /* Handle initializers that use braces. */
4792
4793 /* Type of object we are accumulating a constructor for.
4794 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4795 static tree constructor_type;
4796
4797 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4798 left to fill. */
4799 static tree constructor_fields;
4800
4801 /* For an ARRAY_TYPE, this is the specified index
4802 at which to store the next element we get. */
4803 static tree constructor_index;
4804
4805 /* For an ARRAY_TYPE, this is the maximum index. */
4806 static tree constructor_max_index;
4807
4808 /* For a RECORD_TYPE, this is the first field not yet written out. */
4809 static tree constructor_unfilled_fields;
4810
4811 /* For an ARRAY_TYPE, this is the index of the first element
4812 not yet written out. */
4813 static tree constructor_unfilled_index;
4814
4815 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4816 This is so we can generate gaps between fields, when appropriate. */
4817 static tree constructor_bit_index;
4818
4819 /* If we are saving up the elements rather than allocating them,
4820 this is the list of elements so far (in reverse order,
4821 most recent first). */
4822 static VEC(constructor_elt,gc) *constructor_elements;
4823
4824 /* 1 if constructor should be incrementally stored into a constructor chain,
4825 0 if all the elements should be kept in AVL tree. */
4826 static int constructor_incremental;
4827
4828 /* 1 if so far this constructor's elements are all compile-time constants. */
4829 static int constructor_constant;
4830
4831 /* 1 if so far this constructor's elements are all valid address constants. */
4832 static int constructor_simple;
4833
4834 /* 1 if this constructor is erroneous so far. */
4835 static int constructor_erroneous;
4836
4837 /* Structure for managing pending initializer elements, organized as an
4838 AVL tree. */
4839
4840 struct init_node
4841 {
4842 struct init_node *left, *right;
4843 struct init_node *parent;
4844 int balance;
4845 tree purpose;
4846 tree value;
4847 };
4848
4849 /* Tree of pending elements at this constructor level.
4850 These are elements encountered out of order
4851 which belong at places we haven't reached yet in actually
4852 writing the output.
4853 Will never hold tree nodes across GC runs. */
4854 static struct init_node *constructor_pending_elts;
4855
4856 /* The SPELLING_DEPTH of this constructor. */
4857 static int constructor_depth;
4858
4859 /* DECL node for which an initializer is being read.
4860 0 means we are reading a constructor expression
4861 such as (struct foo) {...}. */
4862 static tree constructor_decl;
4863
4864 /* Nonzero if this is an initializer for a top-level decl. */
4865 static int constructor_top_level;
4866
4867 /* Nonzero if there were any member designators in this initializer. */
4868 static int constructor_designated;
4869
4870 /* Nesting depth of designator list. */
4871 static int designator_depth;
4872
4873 /* Nonzero if there were diagnosed errors in this designator list. */
4874 static int designator_erroneous;
4875
4876 \f
4877 /* This stack has a level for each implicit or explicit level of
4878 structuring in the initializer, including the outermost one. It
4879 saves the values of most of the variables above. */
4880
4881 struct constructor_range_stack;
4882
4883 struct constructor_stack
4884 {
4885 struct constructor_stack *next;
4886 tree type;
4887 tree fields;
4888 tree index;
4889 tree max_index;
4890 tree unfilled_index;
4891 tree unfilled_fields;
4892 tree bit_index;
4893 VEC(constructor_elt,gc) *elements;
4894 struct init_node *pending_elts;
4895 int offset;
4896 int depth;
4897 /* If value nonzero, this value should replace the entire
4898 constructor at this level. */
4899 struct c_expr replacement_value;
4900 struct constructor_range_stack *range_stack;
4901 char constant;
4902 char simple;
4903 char implicit;
4904 char erroneous;
4905 char outer;
4906 char incremental;
4907 char designated;
4908 };
4909
4910 static struct constructor_stack *constructor_stack;
4911
4912 /* This stack represents designators from some range designator up to
4913 the last designator in the list. */
4914
4915 struct constructor_range_stack
4916 {
4917 struct constructor_range_stack *next, *prev;
4918 struct constructor_stack *stack;
4919 tree range_start;
4920 tree index;
4921 tree range_end;
4922 tree fields;
4923 };
4924
4925 static struct constructor_range_stack *constructor_range_stack;
4926
4927 /* This stack records separate initializers that are nested.
4928 Nested initializers can't happen in ANSI C, but GNU C allows them
4929 in cases like { ... (struct foo) { ... } ... }. */
4930
4931 struct initializer_stack
4932 {
4933 struct initializer_stack *next;
4934 tree decl;
4935 struct constructor_stack *constructor_stack;
4936 struct constructor_range_stack *constructor_range_stack;
4937 VEC(constructor_elt,gc) *elements;
4938 struct spelling *spelling;
4939 struct spelling *spelling_base;
4940 int spelling_size;
4941 char top_level;
4942 char require_constant_value;
4943 char require_constant_elements;
4944 };
4945
4946 static struct initializer_stack *initializer_stack;
4947 \f
4948 /* Prepare to parse and output the initializer for variable DECL. */
4949
4950 void
4951 start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level)
4952 {
4953 const char *locus;
4954 struct initializer_stack *p = XNEW (struct initializer_stack);
4955
4956 p->decl = constructor_decl;
4957 p->require_constant_value = require_constant_value;
4958 p->require_constant_elements = require_constant_elements;
4959 p->constructor_stack = constructor_stack;
4960 p->constructor_range_stack = constructor_range_stack;
4961 p->elements = constructor_elements;
4962 p->spelling = spelling;
4963 p->spelling_base = spelling_base;
4964 p->spelling_size = spelling_size;
4965 p->top_level = constructor_top_level;
4966 p->next = initializer_stack;
4967 initializer_stack = p;
4968
4969 constructor_decl = decl;
4970 constructor_designated = 0;
4971 constructor_top_level = top_level;
4972
4973 if (decl != 0 && decl != error_mark_node)
4974 {
4975 require_constant_value = TREE_STATIC (decl);
4976 require_constant_elements
4977 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
4978 /* For a scalar, you can always use any value to initialize,
4979 even within braces. */
4980 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
4981 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
4982 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
4983 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
4984 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
4985 }
4986 else
4987 {
4988 require_constant_value = 0;
4989 require_constant_elements = 0;
4990 locus = "(anonymous)";
4991 }
4992
4993 constructor_stack = 0;
4994 constructor_range_stack = 0;
4995
4996 missing_braces_mentioned = 0;
4997
4998 spelling_base = 0;
4999 spelling_size = 0;
5000 RESTORE_SPELLING_DEPTH (0);
5001
5002 if (locus)
5003 push_string (locus);
5004 }
5005
5006 void
5007 finish_init (void)
5008 {
5009 struct initializer_stack *p = initializer_stack;
5010
5011 /* Free the whole constructor stack of this initializer. */
5012 while (constructor_stack)
5013 {
5014 struct constructor_stack *q = constructor_stack;
5015 constructor_stack = q->next;
5016 free (q);
5017 }
5018
5019 gcc_assert (!constructor_range_stack);
5020
5021 /* Pop back to the data of the outer initializer (if any). */
5022 free (spelling_base);
5023
5024 constructor_decl = p->decl;
5025 require_constant_value = p->require_constant_value;
5026 require_constant_elements = p->require_constant_elements;
5027 constructor_stack = p->constructor_stack;
5028 constructor_range_stack = p->constructor_range_stack;
5029 constructor_elements = p->elements;
5030 spelling = p->spelling;
5031 spelling_base = p->spelling_base;
5032 spelling_size = p->spelling_size;
5033 constructor_top_level = p->top_level;
5034 initializer_stack = p->next;
5035 free (p);
5036 }
5037 \f
5038 /* Call here when we see the initializer is surrounded by braces.
5039 This is instead of a call to push_init_level;
5040 it is matched by a call to pop_init_level.
5041
5042 TYPE is the type to initialize, for a constructor expression.
5043 For an initializer for a decl, TYPE is zero. */
5044
5045 void
5046 really_start_incremental_init (tree type)
5047 {
5048 struct constructor_stack *p = XNEW (struct constructor_stack);
5049
5050 if (type == 0)
5051 type = TREE_TYPE (constructor_decl);
5052
5053 if (targetm.vector_opaque_p (type))
5054 error ("opaque vector types cannot be initialized");
5055
5056 p->type = constructor_type;
5057 p->fields = constructor_fields;
5058 p->index = constructor_index;
5059 p->max_index = constructor_max_index;
5060 p->unfilled_index = constructor_unfilled_index;
5061 p->unfilled_fields = constructor_unfilled_fields;
5062 p->bit_index = constructor_bit_index;
5063 p->elements = constructor_elements;
5064 p->constant = constructor_constant;
5065 p->simple = constructor_simple;
5066 p->erroneous = constructor_erroneous;
5067 p->pending_elts = constructor_pending_elts;
5068 p->depth = constructor_depth;
5069 p->replacement_value.value = 0;
5070 p->replacement_value.original_code = ERROR_MARK;
5071 p->implicit = 0;
5072 p->range_stack = 0;
5073 p->outer = 0;
5074 p->incremental = constructor_incremental;
5075 p->designated = constructor_designated;
5076 p->next = 0;
5077 constructor_stack = p;
5078
5079 constructor_constant = 1;
5080 constructor_simple = 1;
5081 constructor_depth = SPELLING_DEPTH ();
5082 constructor_elements = 0;
5083 constructor_pending_elts = 0;
5084 constructor_type = type;
5085 constructor_incremental = 1;
5086 constructor_designated = 0;
5087 designator_depth = 0;
5088 designator_erroneous = 0;
5089
5090 if (TREE_CODE (constructor_type) == RECORD_TYPE
5091 || TREE_CODE (constructor_type) == UNION_TYPE)
5092 {
5093 constructor_fields = TYPE_FIELDS (constructor_type);
5094 /* Skip any nameless bit fields at the beginning. */
5095 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5096 && DECL_NAME (constructor_fields) == 0)
5097 constructor_fields = TREE_CHAIN (constructor_fields);
5098
5099 constructor_unfilled_fields = constructor_fields;
5100 constructor_bit_index = bitsize_zero_node;
5101 }
5102 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5103 {
5104 if (TYPE_DOMAIN (constructor_type))
5105 {
5106 constructor_max_index
5107 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5108
5109 /* Detect non-empty initializations of zero-length arrays. */
5110 if (constructor_max_index == NULL_TREE
5111 && TYPE_SIZE (constructor_type))
5112 constructor_max_index = build_int_cst (NULL_TREE, -1);
5113
5114 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5115 to initialize VLAs will cause a proper error; avoid tree
5116 checking errors as well by setting a safe value. */
5117 if (constructor_max_index
5118 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5119 constructor_max_index = build_int_cst (NULL_TREE, -1);
5120
5121 constructor_index
5122 = convert (bitsizetype,
5123 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5124 }
5125 else
5126 {
5127 constructor_index = bitsize_zero_node;
5128 constructor_max_index = NULL_TREE;
5129 }
5130
5131 constructor_unfilled_index = constructor_index;
5132 }
5133 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5134 {
5135 /* Vectors are like simple fixed-size arrays. */
5136 constructor_max_index =
5137 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5138 constructor_index = bitsize_zero_node;
5139 constructor_unfilled_index = constructor_index;
5140 }
5141 else
5142 {
5143 /* Handle the case of int x = {5}; */
5144 constructor_fields = constructor_type;
5145 constructor_unfilled_fields = constructor_type;
5146 }
5147 }
5148 \f
5149 /* Push down into a subobject, for initialization.
5150 If this is for an explicit set of braces, IMPLICIT is 0.
5151 If it is because the next element belongs at a lower level,
5152 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5153
5154 void
5155 push_init_level (int implicit)
5156 {
5157 struct constructor_stack *p;
5158 tree value = NULL_TREE;
5159
5160 /* If we've exhausted any levels that didn't have braces,
5161 pop them now. If implicit == 1, this will have been done in
5162 process_init_element; do not repeat it here because in the case
5163 of excess initializers for an empty aggregate this leads to an
5164 infinite cycle of popping a level and immediately recreating
5165 it. */
5166 if (implicit != 1)
5167 {
5168 while (constructor_stack->implicit)
5169 {
5170 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5171 || TREE_CODE (constructor_type) == UNION_TYPE)
5172 && constructor_fields == 0)
5173 process_init_element (pop_init_level (1));
5174 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5175 && constructor_max_index
5176 && tree_int_cst_lt (constructor_max_index,
5177 constructor_index))
5178 process_init_element (pop_init_level (1));
5179 else
5180 break;
5181 }
5182 }
5183
5184 /* Unless this is an explicit brace, we need to preserve previous
5185 content if any. */
5186 if (implicit)
5187 {
5188 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5189 || TREE_CODE (constructor_type) == UNION_TYPE)
5190 && constructor_fields)
5191 value = find_init_member (constructor_fields);
5192 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5193 value = find_init_member (constructor_index);
5194 }
5195
5196 p = XNEW (struct constructor_stack);
5197 p->type = constructor_type;
5198 p->fields = constructor_fields;
5199 p->index = constructor_index;
5200 p->max_index = constructor_max_index;
5201 p->unfilled_index = constructor_unfilled_index;
5202 p->unfilled_fields = constructor_unfilled_fields;
5203 p->bit_index = constructor_bit_index;
5204 p->elements = constructor_elements;
5205 p->constant = constructor_constant;
5206 p->simple = constructor_simple;
5207 p->erroneous = constructor_erroneous;
5208 p->pending_elts = constructor_pending_elts;
5209 p->depth = constructor_depth;
5210 p->replacement_value.value = 0;
5211 p->replacement_value.original_code = ERROR_MARK;
5212 p->implicit = implicit;
5213 p->outer = 0;
5214 p->incremental = constructor_incremental;
5215 p->designated = constructor_designated;
5216 p->next = constructor_stack;
5217 p->range_stack = 0;
5218 constructor_stack = p;
5219
5220 constructor_constant = 1;
5221 constructor_simple = 1;
5222 constructor_depth = SPELLING_DEPTH ();
5223 constructor_elements = 0;
5224 constructor_incremental = 1;
5225 constructor_designated = 0;
5226 constructor_pending_elts = 0;
5227 if (!implicit)
5228 {
5229 p->range_stack = constructor_range_stack;
5230 constructor_range_stack = 0;
5231 designator_depth = 0;
5232 designator_erroneous = 0;
5233 }
5234
5235 /* Don't die if an entire brace-pair level is superfluous
5236 in the containing level. */
5237 if (constructor_type == 0)
5238 ;
5239 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5240 || TREE_CODE (constructor_type) == UNION_TYPE)
5241 {
5242 /* Don't die if there are extra init elts at the end. */
5243 if (constructor_fields == 0)
5244 constructor_type = 0;
5245 else
5246 {
5247 constructor_type = TREE_TYPE (constructor_fields);
5248 push_member_name (constructor_fields);
5249 constructor_depth++;
5250 }
5251 }
5252 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5253 {
5254 constructor_type = TREE_TYPE (constructor_type);
5255 push_array_bounds (tree_low_cst (constructor_index, 1));
5256 constructor_depth++;
5257 }
5258
5259 if (constructor_type == 0)
5260 {
5261 error_init ("extra brace group at end of initializer");
5262 constructor_fields = 0;
5263 constructor_unfilled_fields = 0;
5264 return;
5265 }
5266
5267 if (value && TREE_CODE (value) == CONSTRUCTOR)
5268 {
5269 constructor_constant = TREE_CONSTANT (value);
5270 constructor_simple = TREE_STATIC (value);
5271 constructor_elements = CONSTRUCTOR_ELTS (value);
5272 if (!VEC_empty (constructor_elt, constructor_elements)
5273 && (TREE_CODE (constructor_type) == RECORD_TYPE
5274 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5275 set_nonincremental_init ();
5276 }
5277
5278 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5279 {
5280 missing_braces_mentioned = 1;
5281 warning_init ("missing braces around initializer");
5282 }
5283
5284 if (TREE_CODE (constructor_type) == RECORD_TYPE
5285 || TREE_CODE (constructor_type) == UNION_TYPE)
5286 {
5287 constructor_fields = TYPE_FIELDS (constructor_type);
5288 /* Skip any nameless bit fields at the beginning. */
5289 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5290 && DECL_NAME (constructor_fields) == 0)
5291 constructor_fields = TREE_CHAIN (constructor_fields);
5292
5293 constructor_unfilled_fields = constructor_fields;
5294 constructor_bit_index = bitsize_zero_node;
5295 }
5296 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5297 {
5298 /* Vectors are like simple fixed-size arrays. */
5299 constructor_max_index =
5300 build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1);
5301 constructor_index = convert (bitsizetype, integer_zero_node);
5302 constructor_unfilled_index = constructor_index;
5303 }
5304 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5305 {
5306 if (TYPE_DOMAIN (constructor_type))
5307 {
5308 constructor_max_index
5309 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5310
5311 /* Detect non-empty initializations of zero-length arrays. */
5312 if (constructor_max_index == NULL_TREE
5313 && TYPE_SIZE (constructor_type))
5314 constructor_max_index = build_int_cst (NULL_TREE, -1);
5315
5316 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5317 to initialize VLAs will cause a proper error; avoid tree
5318 checking errors as well by setting a safe value. */
5319 if (constructor_max_index
5320 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5321 constructor_max_index = build_int_cst (NULL_TREE, -1);
5322
5323 constructor_index
5324 = convert (bitsizetype,
5325 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5326 }
5327 else
5328 constructor_index = bitsize_zero_node;
5329
5330 constructor_unfilled_index = constructor_index;
5331 if (value && TREE_CODE (value) == STRING_CST)
5332 {
5333 /* We need to split the char/wchar array into individual
5334 characters, so that we don't have to special case it
5335 everywhere. */
5336 set_nonincremental_init_from_string (value);
5337 }
5338 }
5339 else
5340 {
5341 if (constructor_type != error_mark_node)
5342 warning_init ("braces around scalar initializer");
5343 constructor_fields = constructor_type;
5344 constructor_unfilled_fields = constructor_type;
5345 }
5346 }
5347
5348 /* At the end of an implicit or explicit brace level,
5349 finish up that level of constructor. If a single expression
5350 with redundant braces initialized that level, return the
5351 c_expr structure for that expression. Otherwise, the original_code
5352 element is set to ERROR_MARK.
5353 If we were outputting the elements as they are read, return 0 as the value
5354 from inner levels (process_init_element ignores that),
5355 but return error_mark_node as the value from the outermost level
5356 (that's what we want to put in DECL_INITIAL).
5357 Otherwise, return a CONSTRUCTOR expression as the value. */
5358
5359 struct c_expr
5360 pop_init_level (int implicit)
5361 {
5362 struct constructor_stack *p;
5363 struct c_expr ret;
5364 ret.value = 0;
5365 ret.original_code = ERROR_MARK;
5366
5367 if (implicit == 0)
5368 {
5369 /* When we come to an explicit close brace,
5370 pop any inner levels that didn't have explicit braces. */
5371 while (constructor_stack->implicit)
5372 process_init_element (pop_init_level (1));
5373
5374 gcc_assert (!constructor_range_stack);
5375 }
5376
5377 /* Now output all pending elements. */
5378 constructor_incremental = 1;
5379 output_pending_init_elements (1);
5380
5381 p = constructor_stack;
5382
5383 /* Error for initializing a flexible array member, or a zero-length
5384 array member in an inappropriate context. */
5385 if (constructor_type && constructor_fields
5386 && TREE_CODE (constructor_type) == ARRAY_TYPE
5387 && TYPE_DOMAIN (constructor_type)
5388 && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5389 {
5390 /* Silently discard empty initializations. The parser will
5391 already have pedwarned for empty brackets. */
5392 if (integer_zerop (constructor_unfilled_index))
5393 constructor_type = NULL_TREE;
5394 else
5395 {
5396 gcc_assert (!TYPE_SIZE (constructor_type));
5397
5398 if (constructor_depth > 2)
5399 error_init ("initialization of flexible array member in a nested context");
5400 else if (pedantic)
5401 pedwarn_init ("initialization of a flexible array member");
5402
5403 /* We have already issued an error message for the existence
5404 of a flexible array member not at the end of the structure.
5405 Discard the initializer so that we do not die later. */
5406 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5407 constructor_type = NULL_TREE;
5408 }
5409 }
5410
5411 /* Warn when some struct elements are implicitly initialized to zero. */
5412 if (warn_missing_field_initializers
5413 && constructor_type
5414 && TREE_CODE (constructor_type) == RECORD_TYPE
5415 && constructor_unfilled_fields)
5416 {
5417 /* Do not warn for flexible array members or zero-length arrays. */
5418 while (constructor_unfilled_fields
5419 && (!DECL_SIZE (constructor_unfilled_fields)
5420 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5421 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5422
5423 /* Do not warn if this level of the initializer uses member
5424 designators; it is likely to be deliberate. */
5425 if (constructor_unfilled_fields && !constructor_designated)
5426 {
5427 push_member_name (constructor_unfilled_fields);
5428 warning_init ("missing initializer");
5429 RESTORE_SPELLING_DEPTH (constructor_depth);
5430 }
5431 }
5432
5433 /* Pad out the end of the structure. */
5434 if (p->replacement_value.value)
5435 /* If this closes a superfluous brace pair,
5436 just pass out the element between them. */
5437 ret = p->replacement_value;
5438 else if (constructor_type == 0)
5439 ;
5440 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5441 && TREE_CODE (constructor_type) != UNION_TYPE
5442 && TREE_CODE (constructor_type) != ARRAY_TYPE
5443 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5444 {
5445 /* A nonincremental scalar initializer--just return
5446 the element, after verifying there is just one. */
5447 if (VEC_empty (constructor_elt,constructor_elements))
5448 {
5449 if (!constructor_erroneous)
5450 error_init ("empty scalar initializer");
5451 ret.value = error_mark_node;
5452 }
5453 else if (VEC_length (constructor_elt,constructor_elements) != 1)
5454 {
5455 error_init ("extra elements in scalar initializer");
5456 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5457 }
5458 else
5459 ret.value = VEC_index (constructor_elt,constructor_elements,0)->value;
5460 }
5461 else
5462 {
5463 if (constructor_erroneous)
5464 ret.value = error_mark_node;
5465 else
5466 {
5467 ret.value = build_constructor (constructor_type,
5468 constructor_elements);
5469 if (constructor_constant)
5470 TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1;
5471 if (constructor_constant && constructor_simple)
5472 TREE_STATIC (ret.value) = 1;
5473 }
5474 }
5475
5476 constructor_type = p->type;
5477 constructor_fields = p->fields;
5478 constructor_index = p->index;
5479 constructor_max_index = p->max_index;
5480 constructor_unfilled_index = p->unfilled_index;
5481 constructor_unfilled_fields = p->unfilled_fields;
5482 constructor_bit_index = p->bit_index;
5483 constructor_elements = p->elements;
5484 constructor_constant = p->constant;
5485 constructor_simple = p->simple;
5486 constructor_erroneous = p->erroneous;
5487 constructor_incremental = p->incremental;
5488 constructor_designated = p->designated;
5489 constructor_pending_elts = p->pending_elts;
5490 constructor_depth = p->depth;
5491 if (!p->implicit)
5492 constructor_range_stack = p->range_stack;
5493 RESTORE_SPELLING_DEPTH (constructor_depth);
5494
5495 constructor_stack = p->next;
5496 free (p);
5497
5498 if (ret.value == 0 && constructor_stack == 0)
5499 ret.value = error_mark_node;
5500 return ret;
5501 }
5502
5503 /* Common handling for both array range and field name designators.
5504 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5505
5506 static int
5507 set_designator (int array)
5508 {
5509 tree subtype;
5510 enum tree_code subcode;
5511
5512 /* Don't die if an entire brace-pair level is superfluous
5513 in the containing level. */
5514 if (constructor_type == 0)
5515 return 1;
5516
5517 /* If there were errors in this designator list already, bail out
5518 silently. */
5519 if (designator_erroneous)
5520 return 1;
5521
5522 if (!designator_depth)
5523 {
5524 gcc_assert (!constructor_range_stack);
5525
5526 /* Designator list starts at the level of closest explicit
5527 braces. */
5528 while (constructor_stack->implicit)
5529 process_init_element (pop_init_level (1));
5530 constructor_designated = 1;
5531 return 0;
5532 }
5533
5534 switch (TREE_CODE (constructor_type))
5535 {
5536 case RECORD_TYPE:
5537 case UNION_TYPE:
5538 subtype = TREE_TYPE (constructor_fields);
5539 if (subtype != error_mark_node)
5540 subtype = TYPE_MAIN_VARIANT (subtype);
5541 break;
5542 case ARRAY_TYPE:
5543 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5544 break;
5545 default:
5546 gcc_unreachable ();
5547 }
5548
5549 subcode = TREE_CODE (subtype);
5550 if (array && subcode != ARRAY_TYPE)
5551 {
5552 error_init ("array index in non-array initializer");
5553 return 1;
5554 }
5555 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5556 {
5557 error_init ("field name not in record or union initializer");
5558 return 1;
5559 }
5560
5561 constructor_designated = 1;
5562 push_init_level (2);
5563 return 0;
5564 }
5565
5566 /* If there are range designators in designator list, push a new designator
5567 to constructor_range_stack. RANGE_END is end of such stack range or
5568 NULL_TREE if there is no range designator at this level. */
5569
5570 static void
5571 push_range_stack (tree range_end)
5572 {
5573 struct constructor_range_stack *p;
5574
5575 p = GGC_NEW (struct constructor_range_stack);
5576 p->prev = constructor_range_stack;
5577 p->next = 0;
5578 p->fields = constructor_fields;
5579 p->range_start = constructor_index;
5580 p->index = constructor_index;
5581 p->stack = constructor_stack;
5582 p->range_end = range_end;
5583 if (constructor_range_stack)
5584 constructor_range_stack->next = p;
5585 constructor_range_stack = p;
5586 }
5587
5588 /* Within an array initializer, specify the next index to be initialized.
5589 FIRST is that index. If LAST is nonzero, then initialize a range
5590 of indices, running from FIRST through LAST. */
5591
5592 void
5593 set_init_index (tree first, tree last)
5594 {
5595 if (set_designator (1))
5596 return;
5597
5598 designator_erroneous = 1;
5599
5600 if (!INTEGRAL_TYPE_P (TREE_TYPE (first))
5601 || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last))))
5602 {
5603 error_init ("array index in initializer not of integer type");
5604 return;
5605 }
5606
5607 if (TREE_CODE (first) != INTEGER_CST)
5608 error_init ("nonconstant array index in initializer");
5609 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5610 error_init ("nonconstant array index in initializer");
5611 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5612 error_init ("array index in non-array initializer");
5613 else if (tree_int_cst_sgn (first) == -1)
5614 error_init ("array index in initializer exceeds array bounds");
5615 else if (constructor_max_index
5616 && tree_int_cst_lt (constructor_max_index, first))
5617 error_init ("array index in initializer exceeds array bounds");
5618 else
5619 {
5620 constructor_index = convert (bitsizetype, first);
5621
5622 if (last)
5623 {
5624 if (tree_int_cst_equal (first, last))
5625 last = 0;
5626 else if (tree_int_cst_lt (last, first))
5627 {
5628 error_init ("empty index range in initializer");
5629 last = 0;
5630 }
5631 else
5632 {
5633 last = convert (bitsizetype, last);
5634 if (constructor_max_index != 0
5635 && tree_int_cst_lt (constructor_max_index, last))
5636 {
5637 error_init ("array index range in initializer exceeds array bounds");
5638 last = 0;
5639 }
5640 }
5641 }
5642
5643 designator_depth++;
5644 designator_erroneous = 0;
5645 if (constructor_range_stack || last)
5646 push_range_stack (last);
5647 }
5648 }
5649
5650 /* Within a struct initializer, specify the next field to be initialized. */
5651
5652 void
5653 set_init_label (tree fieldname)
5654 {
5655 tree tail;
5656
5657 if (set_designator (0))
5658 return;
5659
5660 designator_erroneous = 1;
5661
5662 if (TREE_CODE (constructor_type) != RECORD_TYPE
5663 && TREE_CODE (constructor_type) != UNION_TYPE)
5664 {
5665 error_init ("field name not in record or union initializer");
5666 return;
5667 }
5668
5669 for (tail = TYPE_FIELDS (constructor_type); tail;
5670 tail = TREE_CHAIN (tail))
5671 {
5672 if (DECL_NAME (tail) == fieldname)
5673 break;
5674 }
5675
5676 if (tail == 0)
5677 error ("unknown field %qE specified in initializer", fieldname);
5678 else
5679 {
5680 constructor_fields = tail;
5681 designator_depth++;
5682 designator_erroneous = 0;
5683 if (constructor_range_stack)
5684 push_range_stack (NULL_TREE);
5685 }
5686 }
5687 \f
5688 /* Add a new initializer to the tree of pending initializers. PURPOSE
5689 identifies the initializer, either array index or field in a structure.
5690 VALUE is the value of that index or field. */
5691
5692 static void
5693 add_pending_init (tree purpose, tree value)
5694 {
5695 struct init_node *p, **q, *r;
5696
5697 q = &constructor_pending_elts;
5698 p = 0;
5699
5700 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5701 {
5702 while (*q != 0)
5703 {
5704 p = *q;
5705 if (tree_int_cst_lt (purpose, p->purpose))
5706 q = &p->left;
5707 else if (tree_int_cst_lt (p->purpose, purpose))
5708 q = &p->right;
5709 else
5710 {
5711 if (TREE_SIDE_EFFECTS (p->value))
5712 warning_init ("initialized field with side-effects overwritten");
5713 else if (warn_override_init)
5714 warning_init ("initialized field overwritten");
5715 p->value = value;
5716 return;
5717 }
5718 }
5719 }
5720 else
5721 {
5722 tree bitpos;
5723
5724 bitpos = bit_position (purpose);
5725 while (*q != NULL)
5726 {
5727 p = *q;
5728 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5729 q = &p->left;
5730 else if (p->purpose != purpose)
5731 q = &p->right;
5732 else
5733 {
5734 if (TREE_SIDE_EFFECTS (p->value))
5735 warning_init ("initialized field with side-effects overwritten");
5736 else if (warn_override_init)
5737 warning_init ("initialized field overwritten");
5738 p->value = value;
5739 return;
5740 }
5741 }
5742 }
5743
5744 r = GGC_NEW (struct init_node);
5745 r->purpose = purpose;
5746 r->value = value;
5747
5748 *q = r;
5749 r->parent = p;
5750 r->left = 0;
5751 r->right = 0;
5752 r->balance = 0;
5753
5754 while (p)
5755 {
5756 struct init_node *s;
5757
5758 if (r == p->left)
5759 {
5760 if (p->balance == 0)
5761 p->balance = -1;
5762 else if (p->balance < 0)
5763 {
5764 if (r->balance < 0)
5765 {
5766 /* L rotation. */
5767 p->left = r->right;
5768 if (p->left)
5769 p->left->parent = p;
5770 r->right = p;
5771
5772 p->balance = 0;
5773 r->balance = 0;
5774
5775 s = p->parent;
5776 p->parent = r;
5777 r->parent = s;
5778 if (s)
5779 {
5780 if (s->left == p)
5781 s->left = r;
5782 else
5783 s->right = r;
5784 }
5785 else
5786 constructor_pending_elts = r;
5787 }
5788 else
5789 {
5790 /* LR rotation. */
5791 struct init_node *t = r->right;
5792
5793 r->right = t->left;
5794 if (r->right)
5795 r->right->parent = r;
5796 t->left = r;
5797
5798 p->left = t->right;
5799 if (p->left)
5800 p->left->parent = p;
5801 t->right = p;
5802
5803 p->balance = t->balance < 0;
5804 r->balance = -(t->balance > 0);
5805 t->balance = 0;
5806
5807 s = p->parent;
5808 p->parent = t;
5809 r->parent = t;
5810 t->parent = s;
5811 if (s)
5812 {
5813 if (s->left == p)
5814 s->left = t;
5815 else
5816 s->right = t;
5817 }
5818 else
5819 constructor_pending_elts = t;
5820 }
5821 break;
5822 }
5823 else
5824 {
5825 /* p->balance == +1; growth of left side balances the node. */
5826 p->balance = 0;
5827 break;
5828 }
5829 }
5830 else /* r == p->right */
5831 {
5832 if (p->balance == 0)
5833 /* Growth propagation from right side. */
5834 p->balance++;
5835 else if (p->balance > 0)
5836 {
5837 if (r->balance > 0)
5838 {
5839 /* R rotation. */
5840 p->right = r->left;
5841 if (p->right)
5842 p->right->parent = p;
5843 r->left = p;
5844
5845 p->balance = 0;
5846 r->balance = 0;
5847
5848 s = p->parent;
5849 p->parent = r;
5850 r->parent = s;
5851 if (s)
5852 {
5853 if (s->left == p)
5854 s->left = r;
5855 else
5856 s->right = r;
5857 }
5858 else
5859 constructor_pending_elts = r;
5860 }
5861 else /* r->balance == -1 */
5862 {
5863 /* RL rotation */
5864 struct init_node *t = r->left;
5865
5866 r->left = t->right;
5867 if (r->left)
5868 r->left->parent = r;
5869 t->right = r;
5870
5871 p->right = t->left;
5872 if (p->right)
5873 p->right->parent = p;
5874 t->left = p;
5875
5876 r->balance = (t->balance < 0);
5877 p->balance = -(t->balance > 0);
5878 t->balance = 0;
5879
5880 s = p->parent;
5881 p->parent = t;
5882 r->parent = t;
5883 t->parent = s;
5884 if (s)
5885 {
5886 if (s->left == p)
5887 s->left = t;
5888 else
5889 s->right = t;
5890 }
5891 else
5892 constructor_pending_elts = t;
5893 }
5894 break;
5895 }
5896 else
5897 {
5898 /* p->balance == -1; growth of right side balances the node. */
5899 p->balance = 0;
5900 break;
5901 }
5902 }
5903
5904 r = p;
5905 p = p->parent;
5906 }
5907 }
5908
5909 /* Build AVL tree from a sorted chain. */
5910
5911 static void
5912 set_nonincremental_init (void)
5913 {
5914 unsigned HOST_WIDE_INT ix;
5915 tree index, value;
5916
5917 if (TREE_CODE (constructor_type) != RECORD_TYPE
5918 && TREE_CODE (constructor_type) != ARRAY_TYPE)
5919 return;
5920
5921 FOR_EACH_CONSTRUCTOR_ELT (constructor_elements, ix, index, value)
5922 add_pending_init (index, value);
5923 constructor_elements = 0;
5924 if (TREE_CODE (constructor_type) == RECORD_TYPE)
5925 {
5926 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
5927 /* Skip any nameless bit fields at the beginning. */
5928 while (constructor_unfilled_fields != 0
5929 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
5930 && DECL_NAME (constructor_unfilled_fields) == 0)
5931 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5932
5933 }
5934 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5935 {
5936 if (TYPE_DOMAIN (constructor_type))
5937 constructor_unfilled_index
5938 = convert (bitsizetype,
5939 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5940 else
5941 constructor_unfilled_index = bitsize_zero_node;
5942 }
5943 constructor_incremental = 0;
5944 }
5945
5946 /* Build AVL tree from a string constant. */
5947
5948 static void
5949 set_nonincremental_init_from_string (tree str)
5950 {
5951 tree value, purpose, type;
5952 HOST_WIDE_INT val[2];
5953 const char *p, *end;
5954 int byte, wchar_bytes, charwidth, bitpos;
5955
5956 gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE);
5957
5958 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5959 == TYPE_PRECISION (char_type_node))
5960 wchar_bytes = 1;
5961 else
5962 {
5963 gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
5964 == TYPE_PRECISION (wchar_type_node));
5965 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
5966 }
5967 charwidth = TYPE_PRECISION (char_type_node);
5968 type = TREE_TYPE (constructor_type);
5969 p = TREE_STRING_POINTER (str);
5970 end = p + TREE_STRING_LENGTH (str);
5971
5972 for (purpose = bitsize_zero_node;
5973 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
5974 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
5975 {
5976 if (wchar_bytes == 1)
5977 {
5978 val[1] = (unsigned char) *p++;
5979 val[0] = 0;
5980 }
5981 else
5982 {
5983 val[0] = 0;
5984 val[1] = 0;
5985 for (byte = 0; byte < wchar_bytes; byte++)
5986 {
5987 if (BYTES_BIG_ENDIAN)
5988 bitpos = (wchar_bytes - byte - 1) * charwidth;
5989 else
5990 bitpos = byte * charwidth;
5991 val[bitpos < HOST_BITS_PER_WIDE_INT]
5992 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
5993 << (bitpos % HOST_BITS_PER_WIDE_INT);
5994 }
5995 }
5996
5997 if (!TYPE_UNSIGNED (type))
5998 {
5999 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6000 if (bitpos < HOST_BITS_PER_WIDE_INT)
6001 {
6002 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6003 {
6004 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6005 val[0] = -1;
6006 }
6007 }
6008 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6009 {
6010 if (val[1] < 0)
6011 val[0] = -1;
6012 }
6013 else if (val[0] & (((HOST_WIDE_INT) 1)
6014 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6015 val[0] |= ((HOST_WIDE_INT) -1)
6016 << (bitpos - HOST_BITS_PER_WIDE_INT);
6017 }
6018
6019 value = build_int_cst_wide (type, val[1], val[0]);
6020 add_pending_init (purpose, value);
6021 }
6022
6023 constructor_incremental = 0;
6024 }
6025
6026 /* Return value of FIELD in pending initializer or zero if the field was
6027 not initialized yet. */
6028
6029 static tree
6030 find_init_member (tree field)
6031 {
6032 struct init_node *p;
6033
6034 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6035 {
6036 if (constructor_incremental
6037 && tree_int_cst_lt (field, constructor_unfilled_index))
6038 set_nonincremental_init ();
6039
6040 p = constructor_pending_elts;
6041 while (p)
6042 {
6043 if (tree_int_cst_lt (field, p->purpose))
6044 p = p->left;
6045 else if (tree_int_cst_lt (p->purpose, field))
6046 p = p->right;
6047 else
6048 return p->value;
6049 }
6050 }
6051 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6052 {
6053 tree bitpos = bit_position (field);
6054
6055 if (constructor_incremental
6056 && (!constructor_unfilled_fields
6057 || tree_int_cst_lt (bitpos,
6058 bit_position (constructor_unfilled_fields))))
6059 set_nonincremental_init ();
6060
6061 p = constructor_pending_elts;
6062 while (p)
6063 {
6064 if (field == p->purpose)
6065 return p->value;
6066 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6067 p = p->left;
6068 else
6069 p = p->right;
6070 }
6071 }
6072 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6073 {
6074 if (!VEC_empty (constructor_elt, constructor_elements)
6075 && (VEC_last (constructor_elt, constructor_elements)->index
6076 == field))
6077 return VEC_last (constructor_elt, constructor_elements)->value;
6078 }
6079 return 0;
6080 }
6081
6082 /* "Output" the next constructor element.
6083 At top level, really output it to assembler code now.
6084 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6085 TYPE is the data type that the containing data type wants here.
6086 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6087 If VALUE is a string constant, STRICT_STRING is true if it is
6088 unparenthesized or we should not warn here for it being parenthesized.
6089 For other types of VALUE, STRICT_STRING is not used.
6090
6091 PENDING if non-nil means output pending elements that belong
6092 right after this element. (PENDING is normally 1;
6093 it is 0 while outputting pending elements, to avoid recursion.) */
6094
6095 static void
6096 output_init_element (tree value, bool strict_string, tree type, tree field,
6097 int pending)
6098 {
6099 constructor_elt *celt;
6100
6101 if (type == error_mark_node || value == error_mark_node)
6102 {
6103 constructor_erroneous = 1;
6104 return;
6105 }
6106 if (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6107 && (TREE_CODE (value) == STRING_CST
6108 || TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
6109 && !(TREE_CODE (value) == STRING_CST
6110 && TREE_CODE (type) == ARRAY_TYPE
6111 && INTEGRAL_TYPE_P (TREE_TYPE (type)))
6112 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6113 TYPE_MAIN_VARIANT (type)))
6114 value = array_to_pointer_conversion (value);
6115
6116 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6117 && require_constant_value && !flag_isoc99 && pending)
6118 {
6119 /* As an extension, allow initializing objects with static storage
6120 duration with compound literals (which are then treated just as
6121 the brace enclosed list they contain). */
6122 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6123 value = DECL_INITIAL (decl);
6124 }
6125
6126 if (value == error_mark_node)
6127 constructor_erroneous = 1;
6128 else if (!TREE_CONSTANT (value))
6129 constructor_constant = 0;
6130 else if (!initializer_constant_valid_p (value, TREE_TYPE (value))
6131 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6132 || TREE_CODE (constructor_type) == UNION_TYPE)
6133 && DECL_C_BIT_FIELD (field)
6134 && TREE_CODE (value) != INTEGER_CST))
6135 constructor_simple = 0;
6136
6137 if (!initializer_constant_valid_p (value, TREE_TYPE (value)))
6138 {
6139 if (require_constant_value)
6140 {
6141 error_init ("initializer element is not constant");
6142 value = error_mark_node;
6143 }
6144 else if (require_constant_elements)
6145 pedwarn ("initializer element is not computable at load time");
6146 }
6147
6148 /* If this field is empty (and not at the end of structure),
6149 don't do anything other than checking the initializer. */
6150 if (field
6151 && (TREE_TYPE (field) == error_mark_node
6152 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6153 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6154 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6155 || TREE_CHAIN (field)))))
6156 return;
6157
6158 value = digest_init (type, value, strict_string, require_constant_value);
6159 if (value == error_mark_node)
6160 {
6161 constructor_erroneous = 1;
6162 return;
6163 }
6164
6165 /* If this element doesn't come next in sequence,
6166 put it on constructor_pending_elts. */
6167 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6168 && (!constructor_incremental
6169 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6170 {
6171 if (constructor_incremental
6172 && tree_int_cst_lt (field, constructor_unfilled_index))
6173 set_nonincremental_init ();
6174
6175 add_pending_init (field, value);
6176 return;
6177 }
6178 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6179 && (!constructor_incremental
6180 || field != constructor_unfilled_fields))
6181 {
6182 /* We do this for records but not for unions. In a union,
6183 no matter which field is specified, it can be initialized
6184 right away since it starts at the beginning of the union. */
6185 if (constructor_incremental)
6186 {
6187 if (!constructor_unfilled_fields)
6188 set_nonincremental_init ();
6189 else
6190 {
6191 tree bitpos, unfillpos;
6192
6193 bitpos = bit_position (field);
6194 unfillpos = bit_position (constructor_unfilled_fields);
6195
6196 if (tree_int_cst_lt (bitpos, unfillpos))
6197 set_nonincremental_init ();
6198 }
6199 }
6200
6201 add_pending_init (field, value);
6202 return;
6203 }
6204 else if (TREE_CODE (constructor_type) == UNION_TYPE
6205 && !VEC_empty (constructor_elt, constructor_elements))
6206 {
6207 if (TREE_SIDE_EFFECTS (VEC_last (constructor_elt,
6208 constructor_elements)->value))
6209 warning_init ("initialized field with side-effects overwritten");
6210 else if (warn_override_init)
6211 warning_init ("initialized field overwritten");
6212
6213 /* We can have just one union field set. */
6214 constructor_elements = 0;
6215 }
6216
6217 /* Otherwise, output this element either to
6218 constructor_elements or to the assembler file. */
6219
6220 celt = VEC_safe_push (constructor_elt, gc, constructor_elements, NULL);
6221 celt->index = field;
6222 celt->value = value;
6223
6224 /* Advance the variable that indicates sequential elements output. */
6225 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6226 constructor_unfilled_index
6227 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6228 bitsize_one_node);
6229 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6230 {
6231 constructor_unfilled_fields
6232 = TREE_CHAIN (constructor_unfilled_fields);
6233
6234 /* Skip any nameless bit fields. */
6235 while (constructor_unfilled_fields != 0
6236 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6237 && DECL_NAME (constructor_unfilled_fields) == 0)
6238 constructor_unfilled_fields =
6239 TREE_CHAIN (constructor_unfilled_fields);
6240 }
6241 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6242 constructor_unfilled_fields = 0;
6243
6244 /* Now output any pending elements which have become next. */
6245 if (pending)
6246 output_pending_init_elements (0);
6247 }
6248
6249 /* Output any pending elements which have become next.
6250 As we output elements, constructor_unfilled_{fields,index}
6251 advances, which may cause other elements to become next;
6252 if so, they too are output.
6253
6254 If ALL is 0, we return when there are
6255 no more pending elements to output now.
6256
6257 If ALL is 1, we output space as necessary so that
6258 we can output all the pending elements. */
6259
6260 static void
6261 output_pending_init_elements (int all)
6262 {
6263 struct init_node *elt = constructor_pending_elts;
6264 tree next;
6265
6266 retry:
6267
6268 /* Look through the whole pending tree.
6269 If we find an element that should be output now,
6270 output it. Otherwise, set NEXT to the element
6271 that comes first among those still pending. */
6272
6273 next = 0;
6274 while (elt)
6275 {
6276 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6277 {
6278 if (tree_int_cst_equal (elt->purpose,
6279 constructor_unfilled_index))
6280 output_init_element (elt->value, true,
6281 TREE_TYPE (constructor_type),
6282 constructor_unfilled_index, 0);
6283 else if (tree_int_cst_lt (constructor_unfilled_index,
6284 elt->purpose))
6285 {
6286 /* Advance to the next smaller node. */
6287 if (elt->left)
6288 elt = elt->left;
6289 else
6290 {
6291 /* We have reached the smallest node bigger than the
6292 current unfilled index. Fill the space first. */
6293 next = elt->purpose;
6294 break;
6295 }
6296 }
6297 else
6298 {
6299 /* Advance to the next bigger node. */
6300 if (elt->right)
6301 elt = elt->right;
6302 else
6303 {
6304 /* We have reached the biggest node in a subtree. Find
6305 the parent of it, which is the next bigger node. */
6306 while (elt->parent && elt->parent->right == elt)
6307 elt = elt->parent;
6308 elt = elt->parent;
6309 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6310 elt->purpose))
6311 {
6312 next = elt->purpose;
6313 break;
6314 }
6315 }
6316 }
6317 }
6318 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6319 || TREE_CODE (constructor_type) == UNION_TYPE)
6320 {
6321 tree ctor_unfilled_bitpos, elt_bitpos;
6322
6323 /* If the current record is complete we are done. */
6324 if (constructor_unfilled_fields == 0)
6325 break;
6326
6327 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6328 elt_bitpos = bit_position (elt->purpose);
6329 /* We can't compare fields here because there might be empty
6330 fields in between. */
6331 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6332 {
6333 constructor_unfilled_fields = elt->purpose;
6334 output_init_element (elt->value, true, TREE_TYPE (elt->purpose),
6335 elt->purpose, 0);
6336 }
6337 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6338 {
6339 /* Advance to the next smaller node. */
6340 if (elt->left)
6341 elt = elt->left;
6342 else
6343 {
6344 /* We have reached the smallest node bigger than the
6345 current unfilled field. Fill the space first. */
6346 next = elt->purpose;
6347 break;
6348 }
6349 }
6350 else
6351 {
6352 /* Advance to the next bigger node. */
6353 if (elt->right)
6354 elt = elt->right;
6355 else
6356 {
6357 /* We have reached the biggest node in a subtree. Find
6358 the parent of it, which is the next bigger node. */
6359 while (elt->parent && elt->parent->right == elt)
6360 elt = elt->parent;
6361 elt = elt->parent;
6362 if (elt
6363 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6364 bit_position (elt->purpose))))
6365 {
6366 next = elt->purpose;
6367 break;
6368 }
6369 }
6370 }
6371 }
6372 }
6373
6374 /* Ordinarily return, but not if we want to output all
6375 and there are elements left. */
6376 if (!(all && next != 0))
6377 return;
6378
6379 /* If it's not incremental, just skip over the gap, so that after
6380 jumping to retry we will output the next successive element. */
6381 if (TREE_CODE (constructor_type) == RECORD_TYPE
6382 || TREE_CODE (constructor_type) == UNION_TYPE)
6383 constructor_unfilled_fields = next;
6384 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6385 constructor_unfilled_index = next;
6386
6387 /* ELT now points to the node in the pending tree with the next
6388 initializer to output. */
6389 goto retry;
6390 }
6391 \f
6392 /* Add one non-braced element to the current constructor level.
6393 This adjusts the current position within the constructor's type.
6394 This may also start or terminate implicit levels
6395 to handle a partly-braced initializer.
6396
6397 Once this has found the correct level for the new element,
6398 it calls output_init_element. */
6399
6400 void
6401 process_init_element (struct c_expr value)
6402 {
6403 tree orig_value = value.value;
6404 int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST;
6405 bool strict_string = value.original_code == STRING_CST;
6406
6407 designator_depth = 0;
6408 designator_erroneous = 0;
6409
6410 /* Handle superfluous braces around string cst as in
6411 char x[] = {"foo"}; */
6412 if (string_flag
6413 && constructor_type
6414 && TREE_CODE (constructor_type) == ARRAY_TYPE
6415 && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type))
6416 && integer_zerop (constructor_unfilled_index))
6417 {
6418 if (constructor_stack->replacement_value.value)
6419 error_init ("excess elements in char array initializer");
6420 constructor_stack->replacement_value = value;
6421 return;
6422 }
6423
6424 if (constructor_stack->replacement_value.value != 0)
6425 {
6426 error_init ("excess elements in struct initializer");
6427 return;
6428 }
6429
6430 /* Ignore elements of a brace group if it is entirely superfluous
6431 and has already been diagnosed. */
6432 if (constructor_type == 0)
6433 return;
6434
6435 /* If we've exhausted any levels that didn't have braces,
6436 pop them now. */
6437 while (constructor_stack->implicit)
6438 {
6439 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6440 || TREE_CODE (constructor_type) == UNION_TYPE)
6441 && constructor_fields == 0)
6442 process_init_element (pop_init_level (1));
6443 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6444 && (constructor_max_index == 0
6445 || tree_int_cst_lt (constructor_max_index,
6446 constructor_index)))
6447 process_init_element (pop_init_level (1));
6448 else
6449 break;
6450 }
6451
6452 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6453 if (constructor_range_stack)
6454 {
6455 /* If value is a compound literal and we'll be just using its
6456 content, don't put it into a SAVE_EXPR. */
6457 if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR
6458 || !require_constant_value
6459 || flag_isoc99)
6460 value.value = save_expr (value.value);
6461 }
6462
6463 while (1)
6464 {
6465 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6466 {
6467 tree fieldtype;
6468 enum tree_code fieldcode;
6469
6470 if (constructor_fields == 0)
6471 {
6472 pedwarn_init ("excess elements in struct initializer");
6473 break;
6474 }
6475
6476 fieldtype = TREE_TYPE (constructor_fields);
6477 if (fieldtype != error_mark_node)
6478 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6479 fieldcode = TREE_CODE (fieldtype);
6480
6481 /* Error for non-static initialization of a flexible array member. */
6482 if (fieldcode == ARRAY_TYPE
6483 && !require_constant_value
6484 && TYPE_SIZE (fieldtype) == NULL_TREE
6485 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6486 {
6487 error_init ("non-static initialization of a flexible array member");
6488 break;
6489 }
6490
6491 /* Accept a string constant to initialize a subarray. */
6492 if (value.value != 0
6493 && fieldcode == ARRAY_TYPE
6494 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6495 && string_flag)
6496 value.value = orig_value;
6497 /* Otherwise, if we have come to a subaggregate,
6498 and we don't have an element of its type, push into it. */
6499 else if (value.value != 0
6500 && value.value != error_mark_node
6501 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6502 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6503 || fieldcode == UNION_TYPE))
6504 {
6505 push_init_level (1);
6506 continue;
6507 }
6508
6509 if (value.value)
6510 {
6511 push_member_name (constructor_fields);
6512 output_init_element (value.value, strict_string,
6513 fieldtype, constructor_fields, 1);
6514 RESTORE_SPELLING_DEPTH (constructor_depth);
6515 }
6516 else
6517 /* Do the bookkeeping for an element that was
6518 directly output as a constructor. */
6519 {
6520 /* For a record, keep track of end position of last field. */
6521 if (DECL_SIZE (constructor_fields))
6522 constructor_bit_index
6523 = size_binop (PLUS_EXPR,
6524 bit_position (constructor_fields),
6525 DECL_SIZE (constructor_fields));
6526
6527 /* If the current field was the first one not yet written out,
6528 it isn't now, so update. */
6529 if (constructor_unfilled_fields == constructor_fields)
6530 {
6531 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6532 /* Skip any nameless bit fields. */
6533 while (constructor_unfilled_fields != 0
6534 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6535 && DECL_NAME (constructor_unfilled_fields) == 0)
6536 constructor_unfilled_fields =
6537 TREE_CHAIN (constructor_unfilled_fields);
6538 }
6539 }
6540
6541 constructor_fields = TREE_CHAIN (constructor_fields);
6542 /* Skip any nameless bit fields at the beginning. */
6543 while (constructor_fields != 0
6544 && DECL_C_BIT_FIELD (constructor_fields)
6545 && DECL_NAME (constructor_fields) == 0)
6546 constructor_fields = TREE_CHAIN (constructor_fields);
6547 }
6548 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6549 {
6550 tree fieldtype;
6551 enum tree_code fieldcode;
6552
6553 if (constructor_fields == 0)
6554 {
6555 pedwarn_init ("excess elements in union initializer");
6556 break;
6557 }
6558
6559 fieldtype = TREE_TYPE (constructor_fields);
6560 if (fieldtype != error_mark_node)
6561 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6562 fieldcode = TREE_CODE (fieldtype);
6563
6564 /* Warn that traditional C rejects initialization of unions.
6565 We skip the warning if the value is zero. This is done
6566 under the assumption that the zero initializer in user
6567 code appears conditioned on e.g. __STDC__ to avoid
6568 "missing initializer" warnings and relies on default
6569 initialization to zero in the traditional C case.
6570 We also skip the warning if the initializer is designated,
6571 again on the assumption that this must be conditional on
6572 __STDC__ anyway (and we've already complained about the
6573 member-designator already). */
6574 if (!in_system_header && !constructor_designated
6575 && !(value.value && (integer_zerop (value.value)
6576 || real_zerop (value.value))))
6577 warning (OPT_Wtraditional, "traditional C rejects initialization "
6578 "of unions");
6579
6580 /* Accept a string constant to initialize a subarray. */
6581 if (value.value != 0
6582 && fieldcode == ARRAY_TYPE
6583 && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype))
6584 && string_flag)
6585 value.value = orig_value;
6586 /* Otherwise, if we have come to a subaggregate,
6587 and we don't have an element of its type, push into it. */
6588 else if (value.value != 0
6589 && value.value != error_mark_node
6590 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype
6591 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6592 || fieldcode == UNION_TYPE))
6593 {
6594 push_init_level (1);
6595 continue;
6596 }
6597
6598 if (value.value)
6599 {
6600 push_member_name (constructor_fields);
6601 output_init_element (value.value, strict_string,
6602 fieldtype, constructor_fields, 1);
6603 RESTORE_SPELLING_DEPTH (constructor_depth);
6604 }
6605 else
6606 /* Do the bookkeeping for an element that was
6607 directly output as a constructor. */
6608 {
6609 constructor_bit_index = DECL_SIZE (constructor_fields);
6610 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6611 }
6612
6613 constructor_fields = 0;
6614 }
6615 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6616 {
6617 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6618 enum tree_code eltcode = TREE_CODE (elttype);
6619
6620 /* Accept a string constant to initialize a subarray. */
6621 if (value.value != 0
6622 && eltcode == ARRAY_TYPE
6623 && INTEGRAL_TYPE_P (TREE_TYPE (elttype))
6624 && string_flag)
6625 value.value = orig_value;
6626 /* Otherwise, if we have come to a subaggregate,
6627 and we don't have an element of its type, push into it. */
6628 else if (value.value != 0
6629 && value.value != error_mark_node
6630 && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype
6631 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6632 || eltcode == UNION_TYPE))
6633 {
6634 push_init_level (1);
6635 continue;
6636 }
6637
6638 if (constructor_max_index != 0
6639 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6640 || integer_all_onesp (constructor_max_index)))
6641 {
6642 pedwarn_init ("excess elements in array initializer");
6643 break;
6644 }
6645
6646 /* Now output the actual element. */
6647 if (value.value)
6648 {
6649 push_array_bounds (tree_low_cst (constructor_index, 1));
6650 output_init_element (value.value, strict_string,
6651 elttype, constructor_index, 1);
6652 RESTORE_SPELLING_DEPTH (constructor_depth);
6653 }
6654
6655 constructor_index
6656 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6657
6658 if (!value.value)
6659 /* If we are doing the bookkeeping for an element that was
6660 directly output as a constructor, we must update
6661 constructor_unfilled_index. */
6662 constructor_unfilled_index = constructor_index;
6663 }
6664 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6665 {
6666 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6667
6668 /* Do a basic check of initializer size. Note that vectors
6669 always have a fixed size derived from their type. */
6670 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6671 {
6672 pedwarn_init ("excess elements in vector initializer");
6673 break;
6674 }
6675
6676 /* Now output the actual element. */
6677 if (value.value)
6678 output_init_element (value.value, strict_string,
6679 elttype, constructor_index, 1);
6680
6681 constructor_index
6682 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6683
6684 if (!value.value)
6685 /* If we are doing the bookkeeping for an element that was
6686 directly output as a constructor, we must update
6687 constructor_unfilled_index. */
6688 constructor_unfilled_index = constructor_index;
6689 }
6690
6691 /* Handle the sole element allowed in a braced initializer
6692 for a scalar variable. */
6693 else if (constructor_type != error_mark_node
6694 && constructor_fields == 0)
6695 {
6696 pedwarn_init ("excess elements in scalar initializer");
6697 break;
6698 }
6699 else
6700 {
6701 if (value.value)
6702 output_init_element (value.value, strict_string,
6703 constructor_type, NULL_TREE, 1);
6704 constructor_fields = 0;
6705 }
6706
6707 /* Handle range initializers either at this level or anywhere higher
6708 in the designator stack. */
6709 if (constructor_range_stack)
6710 {
6711 struct constructor_range_stack *p, *range_stack;
6712 int finish = 0;
6713
6714 range_stack = constructor_range_stack;
6715 constructor_range_stack = 0;
6716 while (constructor_stack != range_stack->stack)
6717 {
6718 gcc_assert (constructor_stack->implicit);
6719 process_init_element (pop_init_level (1));
6720 }
6721 for (p = range_stack;
6722 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6723 p = p->prev)
6724 {
6725 gcc_assert (constructor_stack->implicit);
6726 process_init_element (pop_init_level (1));
6727 }
6728
6729 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6730 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6731 finish = 1;
6732
6733 while (1)
6734 {
6735 constructor_index = p->index;
6736 constructor_fields = p->fields;
6737 if (finish && p->range_end && p->index == p->range_start)
6738 {
6739 finish = 0;
6740 p->prev = 0;
6741 }
6742 p = p->next;
6743 if (!p)
6744 break;
6745 push_init_level (2);
6746 p->stack = constructor_stack;
6747 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6748 p->index = p->range_start;
6749 }
6750
6751 if (!finish)
6752 constructor_range_stack = range_stack;
6753 continue;
6754 }
6755
6756 break;
6757 }
6758
6759 constructor_range_stack = 0;
6760 }
6761 \f
6762 /* Build a complete asm-statement, whose components are a CV_QUALIFIER
6763 (guaranteed to be 'volatile' or null) and ARGS (represented using
6764 an ASM_EXPR node). */
6765 tree
6766 build_asm_stmt (tree cv_qualifier, tree args)
6767 {
6768 if (!ASM_VOLATILE_P (args) && cv_qualifier)
6769 ASM_VOLATILE_P (args) = 1;
6770 return add_stmt (args);
6771 }
6772
6773 /* Build an asm-expr, whose components are a STRING, some OUTPUTS,
6774 some INPUTS, and some CLOBBERS. The latter three may be NULL.
6775 SIMPLE indicates whether there was anything at all after the
6776 string in the asm expression -- asm("blah") and asm("blah" : )
6777 are subtly different. We use a ASM_EXPR node to represent this. */
6778 tree
6779 build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers,
6780 bool simple)
6781 {
6782 tree tail;
6783 tree args;
6784 int i;
6785 const char *constraint;
6786 const char **oconstraints;
6787 bool allows_mem, allows_reg, is_inout;
6788 int ninputs, noutputs;
6789
6790 ninputs = list_length (inputs);
6791 noutputs = list_length (outputs);
6792 oconstraints = (const char **) alloca (noutputs * sizeof (const char *));
6793
6794 string = resolve_asm_operand_names (string, outputs, inputs);
6795
6796 /* Remove output conversions that change the type but not the mode. */
6797 for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail))
6798 {
6799 tree output = TREE_VALUE (tail);
6800
6801 /* ??? Really, this should not be here. Users should be using a
6802 proper lvalue, dammit. But there's a long history of using casts
6803 in the output operands. In cases like longlong.h, this becomes a
6804 primitive form of typechecking -- if the cast can be removed, then
6805 the output operand had a type of the proper width; otherwise we'll
6806 get an error. Gross, but ... */
6807 STRIP_NOPS (output);
6808
6809 if (!lvalue_or_else (output, lv_asm))
6810 output = error_mark_node;
6811
6812 if (output != error_mark_node
6813 && (TREE_READONLY (output)
6814 || TYPE_READONLY (TREE_TYPE (output))
6815 || ((TREE_CODE (TREE_TYPE (output)) == RECORD_TYPE
6816 || TREE_CODE (TREE_TYPE (output)) == UNION_TYPE)
6817 && C_TYPE_FIELDS_READONLY (TREE_TYPE (output)))))
6818 readonly_error (output, lv_asm);
6819
6820 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6821 oconstraints[i] = constraint;
6822
6823 if (parse_output_constraint (&constraint, i, ninputs, noutputs,
6824 &allows_mem, &allows_reg, &is_inout))
6825 {
6826 /* If the operand is going to end up in memory,
6827 mark it addressable. */
6828 if (!allows_reg && !c_mark_addressable (output))
6829 output = error_mark_node;
6830 }
6831 else
6832 output = error_mark_node;
6833
6834 TREE_VALUE (tail) = output;
6835 }
6836
6837 for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail))
6838 {
6839 tree input;
6840
6841 constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail)));
6842 input = TREE_VALUE (tail);
6843
6844 if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0,
6845 oconstraints, &allows_mem, &allows_reg))
6846 {
6847 /* If the operand is going to end up in memory,
6848 mark it addressable. */
6849 if (!allows_reg && allows_mem)
6850 {
6851 /* Strip the nops as we allow this case. FIXME, this really
6852 should be rejected or made deprecated. */
6853 STRIP_NOPS (input);
6854 if (!c_mark_addressable (input))
6855 input = error_mark_node;
6856 }
6857 }
6858 else
6859 input = error_mark_node;
6860
6861 TREE_VALUE (tail) = input;
6862 }
6863
6864 args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers);
6865
6866 /* asm statements without outputs, including simple ones, are treated
6867 as volatile. */
6868 ASM_INPUT_P (args) = simple;
6869 ASM_VOLATILE_P (args) = (noutputs == 0);
6870
6871 return args;
6872 }
6873 \f
6874 /* Generate a goto statement to LABEL. */
6875
6876 tree
6877 c_finish_goto_label (tree label)
6878 {
6879 tree decl = lookup_label (label);
6880 if (!decl)
6881 return NULL_TREE;
6882
6883 if (C_DECL_UNJUMPABLE_STMT_EXPR (decl))
6884 {
6885 error ("jump into statement expression");
6886 return NULL_TREE;
6887 }
6888
6889 if (C_DECL_UNJUMPABLE_VM (decl))
6890 {
6891 error ("jump into scope of identifier with variably modified type");
6892 return NULL_TREE;
6893 }
6894
6895 if (!C_DECL_UNDEFINABLE_STMT_EXPR (decl))
6896 {
6897 /* No jump from outside this statement expression context, so
6898 record that there is a jump from within this context. */
6899 struct c_label_list *nlist;
6900 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6901 nlist->next = label_context_stack_se->labels_used;
6902 nlist->label = decl;
6903 label_context_stack_se->labels_used = nlist;
6904 }
6905
6906 if (!C_DECL_UNDEFINABLE_VM (decl))
6907 {
6908 /* No jump from outside this context context of identifiers with
6909 variably modified type, so record that there is a jump from
6910 within this context. */
6911 struct c_label_list *nlist;
6912 nlist = XOBNEW (&parser_obstack, struct c_label_list);
6913 nlist->next = label_context_stack_vm->labels_used;
6914 nlist->label = decl;
6915 label_context_stack_vm->labels_used = nlist;
6916 }
6917
6918 TREE_USED (decl) = 1;
6919 return add_stmt (build1 (GOTO_EXPR, void_type_node, decl));
6920 }
6921
6922 /* Generate a computed goto statement to EXPR. */
6923
6924 tree
6925 c_finish_goto_ptr (tree expr)
6926 {
6927 if (pedantic)
6928 pedwarn ("ISO C forbids %<goto *expr;%>");
6929 expr = convert (ptr_type_node, expr);
6930 return add_stmt (build1 (GOTO_EXPR, void_type_node, expr));
6931 }
6932
6933 /* Generate a C `return' statement. RETVAL is the expression for what
6934 to return, or a null pointer for `return;' with no value. */
6935
6936 tree
6937 c_finish_return (tree retval)
6938 {
6939 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)), ret_stmt;
6940 bool no_warning = false;
6941
6942 if (TREE_THIS_VOLATILE (current_function_decl))
6943 warning (0, "function declared %<noreturn%> has a %<return%> statement");
6944
6945 if (!retval)
6946 {
6947 current_function_returns_null = 1;
6948 if ((warn_return_type || flag_isoc99)
6949 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
6950 {
6951 pedwarn_c99 ("%<return%> with no value, in "
6952 "function returning non-void");
6953 no_warning = true;
6954 }
6955 }
6956 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
6957 {
6958 current_function_returns_null = 1;
6959 if (TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
6960 pedwarn ("%<return%> with a value, in function returning void");
6961 else if (pedantic)
6962 pedwarn ("ISO C forbids %<return%> with expression, in function returning void");
6963 }
6964 else
6965 {
6966 tree t = convert_for_assignment (valtype, retval, ic_return,
6967 NULL_TREE, NULL_TREE, 0);
6968 tree res = DECL_RESULT (current_function_decl);
6969 tree inner;
6970
6971 current_function_returns_value = 1;
6972 if (t == error_mark_node)
6973 return NULL_TREE;
6974
6975 inner = t = convert (TREE_TYPE (res), t);
6976
6977 /* Strip any conversions, additions, and subtractions, and see if
6978 we are returning the address of a local variable. Warn if so. */
6979 while (1)
6980 {
6981 switch (TREE_CODE (inner))
6982 {
6983 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
6984 case PLUS_EXPR:
6985 inner = TREE_OPERAND (inner, 0);
6986 continue;
6987
6988 case MINUS_EXPR:
6989 /* If the second operand of the MINUS_EXPR has a pointer
6990 type (or is converted from it), this may be valid, so
6991 don't give a warning. */
6992 {
6993 tree op1 = TREE_OPERAND (inner, 1);
6994
6995 while (!POINTER_TYPE_P (TREE_TYPE (op1))
6996 && (TREE_CODE (op1) == NOP_EXPR
6997 || TREE_CODE (op1) == NON_LVALUE_EXPR
6998 || TREE_CODE (op1) == CONVERT_EXPR))
6999 op1 = TREE_OPERAND (op1, 0);
7000
7001 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7002 break;
7003
7004 inner = TREE_OPERAND (inner, 0);
7005 continue;
7006 }
7007
7008 case ADDR_EXPR:
7009 inner = TREE_OPERAND (inner, 0);
7010
7011 while (REFERENCE_CLASS_P (inner)
7012 && TREE_CODE (inner) != INDIRECT_REF)
7013 inner = TREE_OPERAND (inner, 0);
7014
7015 if (DECL_P (inner)
7016 && !DECL_EXTERNAL (inner)
7017 && !TREE_STATIC (inner)
7018 && DECL_CONTEXT (inner) == current_function_decl)
7019 warning (0, "function returns address of local variable");
7020 break;
7021
7022 default:
7023 break;
7024 }
7025
7026 break;
7027 }
7028
7029 retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t);
7030 }
7031
7032 ret_stmt = build_stmt (RETURN_EXPR, retval);
7033 TREE_NO_WARNING (ret_stmt) |= no_warning;
7034 return add_stmt (ret_stmt);
7035 }
7036 \f
7037 struct c_switch {
7038 /* The SWITCH_EXPR being built. */
7039 tree switch_expr;
7040
7041 /* The original type of the testing expression, i.e. before the
7042 default conversion is applied. */
7043 tree orig_type;
7044
7045 /* A splay-tree mapping the low element of a case range to the high
7046 element, or NULL_TREE if there is no high element. Used to
7047 determine whether or not a new case label duplicates an old case
7048 label. We need a tree, rather than simply a hash table, because
7049 of the GNU case range extension. */
7050 splay_tree cases;
7051
7052 /* Number of nested statement expressions within this switch
7053 statement; if nonzero, case and default labels may not
7054 appear. */
7055 unsigned int blocked_stmt_expr;
7056
7057 /* Scope of outermost declarations of identifiers with variably
7058 modified type within this switch statement; if nonzero, case and
7059 default labels may not appear. */
7060 unsigned int blocked_vm;
7061
7062 /* The next node on the stack. */
7063 struct c_switch *next;
7064 };
7065
7066 /* A stack of the currently active switch statements. The innermost
7067 switch statement is on the top of the stack. There is no need to
7068 mark the stack for garbage collection because it is only active
7069 during the processing of the body of a function, and we never
7070 collect at that point. */
7071
7072 struct c_switch *c_switch_stack;
7073
7074 /* Start a C switch statement, testing expression EXP. Return the new
7075 SWITCH_EXPR. */
7076
7077 tree
7078 c_start_case (tree exp)
7079 {
7080 tree orig_type = error_mark_node;
7081 struct c_switch *cs;
7082
7083 if (exp != error_mark_node)
7084 {
7085 orig_type = TREE_TYPE (exp);
7086
7087 if (!INTEGRAL_TYPE_P (orig_type))
7088 {
7089 if (orig_type != error_mark_node)
7090 {
7091 error ("switch quantity not an integer");
7092 orig_type = error_mark_node;
7093 }
7094 exp = integer_zero_node;
7095 }
7096 else
7097 {
7098 tree type = TYPE_MAIN_VARIANT (orig_type);
7099
7100 if (!in_system_header
7101 && (type == long_integer_type_node
7102 || type == long_unsigned_type_node))
7103 warning (OPT_Wtraditional, "%<long%> switch expression not "
7104 "converted to %<int%> in ISO C");
7105
7106 exp = default_conversion (exp);
7107 }
7108 }
7109
7110 /* Add this new SWITCH_EXPR to the stack. */
7111 cs = XNEW (struct c_switch);
7112 cs->switch_expr = build3 (SWITCH_EXPR, orig_type, exp, NULL_TREE, NULL_TREE);
7113 cs->orig_type = orig_type;
7114 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7115 cs->blocked_stmt_expr = 0;
7116 cs->blocked_vm = 0;
7117 cs->next = c_switch_stack;
7118 c_switch_stack = cs;
7119
7120 return add_stmt (cs->switch_expr);
7121 }
7122
7123 /* Process a case label. */
7124
7125 tree
7126 do_case (tree low_value, tree high_value)
7127 {
7128 tree label = NULL_TREE;
7129
7130 if (c_switch_stack && !c_switch_stack->blocked_stmt_expr
7131 && !c_switch_stack->blocked_vm)
7132 {
7133 label = c_add_case_label (c_switch_stack->cases,
7134 SWITCH_COND (c_switch_stack->switch_expr),
7135 c_switch_stack->orig_type,
7136 low_value, high_value);
7137 if (label == error_mark_node)
7138 label = NULL_TREE;
7139 }
7140 else if (c_switch_stack && c_switch_stack->blocked_stmt_expr)
7141 {
7142 if (low_value)
7143 error ("case label in statement expression not containing "
7144 "enclosing switch statement");
7145 else
7146 error ("%<default%> label in statement expression not containing "
7147 "enclosing switch statement");
7148 }
7149 else if (c_switch_stack && c_switch_stack->blocked_vm)
7150 {
7151 if (low_value)
7152 error ("case label in scope of identifier with variably modified "
7153 "type not containing enclosing switch statement");
7154 else
7155 error ("%<default%> label in scope of identifier with variably "
7156 "modified type not containing enclosing switch statement");
7157 }
7158 else if (low_value)
7159 error ("case label not within a switch statement");
7160 else
7161 error ("%<default%> label not within a switch statement");
7162
7163 return label;
7164 }
7165
7166 /* Finish the switch statement. */
7167
7168 void
7169 c_finish_case (tree body)
7170 {
7171 struct c_switch *cs = c_switch_stack;
7172 location_t switch_location;
7173
7174 SWITCH_BODY (cs->switch_expr) = body;
7175
7176 /* We must not be within a statement expression nested in the switch
7177 at this point; we might, however, be within the scope of an
7178 identifier with variably modified type nested in the switch. */
7179 gcc_assert (!cs->blocked_stmt_expr);
7180
7181 /* Emit warnings as needed. */
7182 if (EXPR_HAS_LOCATION (cs->switch_expr))
7183 switch_location = EXPR_LOCATION (cs->switch_expr);
7184 else
7185 switch_location = input_location;
7186 c_do_switch_warnings (cs->cases, switch_location,
7187 TREE_TYPE (cs->switch_expr),
7188 SWITCH_COND (cs->switch_expr));
7189
7190 /* Pop the stack. */
7191 c_switch_stack = cs->next;
7192 splay_tree_delete (cs->cases);
7193 XDELETE (cs);
7194 }
7195 \f
7196 /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND,
7197 THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK
7198 may be null. NESTED_IF is true if THEN_BLOCK contains another IF
7199 statement, and was not surrounded with parenthesis. */
7200
7201 void
7202 c_finish_if_stmt (location_t if_locus, tree cond, tree then_block,
7203 tree else_block, bool nested_if)
7204 {
7205 tree stmt;
7206
7207 /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */
7208 if (warn_parentheses && nested_if && else_block == NULL)
7209 {
7210 tree inner_if = then_block;
7211
7212 /* We know from the grammar productions that there is an IF nested
7213 within THEN_BLOCK. Due to labels and c99 conditional declarations,
7214 it might not be exactly THEN_BLOCK, but should be the last
7215 non-container statement within. */
7216 while (1)
7217 switch (TREE_CODE (inner_if))
7218 {
7219 case COND_EXPR:
7220 goto found;
7221 case BIND_EXPR:
7222 inner_if = BIND_EXPR_BODY (inner_if);
7223 break;
7224 case STATEMENT_LIST:
7225 inner_if = expr_last (then_block);
7226 break;
7227 case TRY_FINALLY_EXPR:
7228 case TRY_CATCH_EXPR:
7229 inner_if = TREE_OPERAND (inner_if, 0);
7230 break;
7231 default:
7232 gcc_unreachable ();
7233 }
7234 found:
7235
7236 if (COND_EXPR_ELSE (inner_if))
7237 warning (OPT_Wparentheses,
7238 "%Hsuggest explicit braces to avoid ambiguous %<else%>",
7239 &if_locus);
7240 }
7241
7242 empty_if_body_warning (then_block, else_block);
7243
7244 stmt = build3 (COND_EXPR, void_type_node, cond, then_block, else_block);
7245 SET_EXPR_LOCATION (stmt, if_locus);
7246 add_stmt (stmt);
7247 }
7248
7249 /* Emit a general-purpose loop construct. START_LOCUS is the location of
7250 the beginning of the loop. COND is the loop condition. COND_IS_FIRST
7251 is false for DO loops. INCR is the FOR increment expression. BODY is
7252 the statement controlled by the loop. BLAB is the break label. CLAB is
7253 the continue label. Everything is allowed to be NULL. */
7254
7255 void
7256 c_finish_loop (location_t start_locus, tree cond, tree incr, tree body,
7257 tree blab, tree clab, bool cond_is_first)
7258 {
7259 tree entry = NULL, exit = NULL, t;
7260
7261 /* If the condition is zero don't generate a loop construct. */
7262 if (cond && integer_zerop (cond))
7263 {
7264 if (cond_is_first)
7265 {
7266 t = build_and_jump (&blab);
7267 SET_EXPR_LOCATION (t, start_locus);
7268 add_stmt (t);
7269 }
7270 }
7271 else
7272 {
7273 tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7274
7275 /* If we have an exit condition, then we build an IF with gotos either
7276 out of the loop, or to the top of it. If there's no exit condition,
7277 then we just build a jump back to the top. */
7278 exit = build_and_jump (&LABEL_EXPR_LABEL (top));
7279
7280 if (cond && !integer_nonzerop (cond))
7281 {
7282 /* Canonicalize the loop condition to the end. This means
7283 generating a branch to the loop condition. Reuse the
7284 continue label, if possible. */
7285 if (cond_is_first)
7286 {
7287 if (incr || !clab)
7288 {
7289 entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
7290 t = build_and_jump (&LABEL_EXPR_LABEL (entry));
7291 }
7292 else
7293 t = build1 (GOTO_EXPR, void_type_node, clab);
7294 SET_EXPR_LOCATION (t, start_locus);
7295 add_stmt (t);
7296 }
7297
7298 t = build_and_jump (&blab);
7299 exit = fold_build3 (COND_EXPR, void_type_node, cond, exit, t);
7300 if (cond_is_first)
7301 SET_EXPR_LOCATION (exit, start_locus);
7302 else
7303 SET_EXPR_LOCATION (exit, input_location);
7304 }
7305
7306 add_stmt (top);
7307 }
7308
7309 if (body)
7310 add_stmt (body);
7311 if (clab)
7312 add_stmt (build1 (LABEL_EXPR, void_type_node, clab));
7313 if (incr)
7314 add_stmt (incr);
7315 if (entry)
7316 add_stmt (entry);
7317 if (exit)
7318 add_stmt (exit);
7319 if (blab)
7320 add_stmt (build1 (LABEL_EXPR, void_type_node, blab));
7321 }
7322
7323 tree
7324 c_finish_bc_stmt (tree *label_p, bool is_break)
7325 {
7326 bool skip;
7327 tree label = *label_p;
7328
7329 /* In switch statements break is sometimes stylistically used after
7330 a return statement. This can lead to spurious warnings about
7331 control reaching the end of a non-void function when it is
7332 inlined. Note that we are calling block_may_fallthru with
7333 language specific tree nodes; this works because
7334 block_may_fallthru returns true when given something it does not
7335 understand. */
7336 skip = !block_may_fallthru (cur_stmt_list);
7337
7338 if (!label)
7339 {
7340 if (!skip)
7341 *label_p = label = create_artificial_label ();
7342 }
7343 else if (TREE_CODE (label) == LABEL_DECL)
7344 ;
7345 else switch (TREE_INT_CST_LOW (label))
7346 {
7347 case 0:
7348 if (is_break)
7349 error ("break statement not within loop or switch");
7350 else
7351 error ("continue statement not within a loop");
7352 return NULL_TREE;
7353
7354 case 1:
7355 gcc_assert (is_break);
7356 error ("break statement used with OpenMP for loop");
7357 return NULL_TREE;
7358
7359 default:
7360 gcc_unreachable ();
7361 }
7362
7363 if (skip)
7364 return NULL_TREE;
7365
7366 return add_stmt (build1 (GOTO_EXPR, void_type_node, label));
7367 }
7368
7369 /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */
7370
7371 static void
7372 emit_side_effect_warnings (tree expr)
7373 {
7374 if (expr == error_mark_node)
7375 ;
7376 else if (!TREE_SIDE_EFFECTS (expr))
7377 {
7378 if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr))
7379 warning (OPT_Wunused_value, "%Hstatement with no effect",
7380 EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location);
7381 }
7382 else
7383 warn_if_unused_value (expr, input_location);
7384 }
7385
7386 /* Process an expression as if it were a complete statement. Emit
7387 diagnostics, but do not call ADD_STMT. */
7388
7389 tree
7390 c_process_expr_stmt (tree expr)
7391 {
7392 if (!expr)
7393 return NULL_TREE;
7394
7395 if (warn_sequence_point)
7396 verify_sequence_points (expr);
7397
7398 if (TREE_TYPE (expr) != error_mark_node
7399 && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr))
7400 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
7401 error ("expression statement has incomplete type");
7402
7403 /* If we're not processing a statement expression, warn about unused values.
7404 Warnings for statement expressions will be emitted later, once we figure
7405 out which is the result. */
7406 if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7407 && warn_unused_value)
7408 emit_side_effect_warnings (expr);
7409
7410 /* If the expression is not of a type to which we cannot assign a line
7411 number, wrap the thing in a no-op NOP_EXPR. */
7412 if (DECL_P (expr) || CONSTANT_CLASS_P (expr))
7413 expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr);
7414
7415 if (CAN_HAVE_LOCATION_P (expr))
7416 SET_EXPR_LOCATION (expr, input_location);
7417
7418 return expr;
7419 }
7420
7421 /* Emit an expression as a statement. */
7422
7423 tree
7424 c_finish_expr_stmt (tree expr)
7425 {
7426 if (expr)
7427 return add_stmt (c_process_expr_stmt (expr));
7428 else
7429 return NULL;
7430 }
7431
7432 /* Do the opposite and emit a statement as an expression. To begin,
7433 create a new binding level and return it. */
7434
7435 tree
7436 c_begin_stmt_expr (void)
7437 {
7438 tree ret;
7439 struct c_label_context_se *nstack;
7440 struct c_label_list *glist;
7441
7442 /* We must force a BLOCK for this level so that, if it is not expanded
7443 later, there is a way to turn off the entire subtree of blocks that
7444 are contained in it. */
7445 keep_next_level ();
7446 ret = c_begin_compound_stmt (true);
7447 if (c_switch_stack)
7448 {
7449 c_switch_stack->blocked_stmt_expr++;
7450 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7451 }
7452 for (glist = label_context_stack_se->labels_used;
7453 glist != NULL;
7454 glist = glist->next)
7455 {
7456 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 1;
7457 }
7458 nstack = XOBNEW (&parser_obstack, struct c_label_context_se);
7459 nstack->labels_def = NULL;
7460 nstack->labels_used = NULL;
7461 nstack->next = label_context_stack_se;
7462 label_context_stack_se = nstack;
7463
7464 /* Mark the current statement list as belonging to a statement list. */
7465 STATEMENT_LIST_STMT_EXPR (ret) = 1;
7466
7467 return ret;
7468 }
7469
7470 tree
7471 c_finish_stmt_expr (tree body)
7472 {
7473 tree last, type, tmp, val;
7474 tree *last_p;
7475 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7476
7477 body = c_end_compound_stmt (body, true);
7478 if (c_switch_stack)
7479 {
7480 gcc_assert (c_switch_stack->blocked_stmt_expr != 0);
7481 c_switch_stack->blocked_stmt_expr--;
7482 }
7483 /* It is no longer possible to jump to labels defined within this
7484 statement expression. */
7485 for (dlist = label_context_stack_se->labels_def;
7486 dlist != NULL;
7487 dlist = dlist->next)
7488 {
7489 C_DECL_UNJUMPABLE_STMT_EXPR (dlist->label) = 1;
7490 }
7491 /* It is again possible to define labels with a goto just outside
7492 this statement expression. */
7493 for (glist = label_context_stack_se->next->labels_used;
7494 glist != NULL;
7495 glist = glist->next)
7496 {
7497 C_DECL_UNDEFINABLE_STMT_EXPR (glist->label) = 0;
7498 glist_prev = glist;
7499 }
7500 if (glist_prev != NULL)
7501 glist_prev->next = label_context_stack_se->labels_used;
7502 else
7503 label_context_stack_se->next->labels_used
7504 = label_context_stack_se->labels_used;
7505 label_context_stack_se = label_context_stack_se->next;
7506
7507 /* Locate the last statement in BODY. See c_end_compound_stmt
7508 about always returning a BIND_EXPR. */
7509 last_p = &BIND_EXPR_BODY (body);
7510 last = BIND_EXPR_BODY (body);
7511
7512 continue_searching:
7513 if (TREE_CODE (last) == STATEMENT_LIST)
7514 {
7515 tree_stmt_iterator i;
7516
7517 /* This can happen with degenerate cases like ({ }). No value. */
7518 if (!TREE_SIDE_EFFECTS (last))
7519 return body;
7520
7521 /* If we're supposed to generate side effects warnings, process
7522 all of the statements except the last. */
7523 if (warn_unused_value)
7524 {
7525 for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i))
7526 emit_side_effect_warnings (tsi_stmt (i));
7527 }
7528 else
7529 i = tsi_last (last);
7530 last_p = tsi_stmt_ptr (i);
7531 last = *last_p;
7532 }
7533
7534 /* If the end of the list is exception related, then the list was split
7535 by a call to push_cleanup. Continue searching. */
7536 if (TREE_CODE (last) == TRY_FINALLY_EXPR
7537 || TREE_CODE (last) == TRY_CATCH_EXPR)
7538 {
7539 last_p = &TREE_OPERAND (last, 0);
7540 last = *last_p;
7541 goto continue_searching;
7542 }
7543
7544 /* In the case that the BIND_EXPR is not necessary, return the
7545 expression out from inside it. */
7546 if (last == error_mark_node
7547 || (last == BIND_EXPR_BODY (body)
7548 && BIND_EXPR_VARS (body) == NULL))
7549 {
7550 /* Do not warn if the return value of a statement expression is
7551 unused. */
7552 if (CAN_HAVE_LOCATION_P (last))
7553 TREE_NO_WARNING (last) = 1;
7554 return last;
7555 }
7556
7557 /* Extract the type of said expression. */
7558 type = TREE_TYPE (last);
7559
7560 /* If we're not returning a value at all, then the BIND_EXPR that
7561 we already have is a fine expression to return. */
7562 if (!type || VOID_TYPE_P (type))
7563 return body;
7564
7565 /* Now that we've located the expression containing the value, it seems
7566 silly to make voidify_wrapper_expr repeat the process. Create a
7567 temporary of the appropriate type and stick it in a TARGET_EXPR. */
7568 tmp = create_tmp_var_raw (type, NULL);
7569
7570 /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids
7571 tree_expr_nonnegative_p giving up immediately. */
7572 val = last;
7573 if (TREE_CODE (val) == NOP_EXPR
7574 && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0)))
7575 val = TREE_OPERAND (val, 0);
7576
7577 *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val);
7578 SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last));
7579
7580 return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE);
7581 }
7582
7583 /* Begin the scope of an identifier of variably modified type, scope
7584 number SCOPE. Jumping from outside this scope to inside it is not
7585 permitted. */
7586
7587 void
7588 c_begin_vm_scope (unsigned int scope)
7589 {
7590 struct c_label_context_vm *nstack;
7591 struct c_label_list *glist;
7592
7593 gcc_assert (scope > 0);
7594
7595 /* At file_scope, we don't have to do any processing. */
7596 if (label_context_stack_vm == NULL)
7597 return;
7598
7599 if (c_switch_stack && !c_switch_stack->blocked_vm)
7600 c_switch_stack->blocked_vm = scope;
7601 for (glist = label_context_stack_vm->labels_used;
7602 glist != NULL;
7603 glist = glist->next)
7604 {
7605 C_DECL_UNDEFINABLE_VM (glist->label) = 1;
7606 }
7607 nstack = XOBNEW (&parser_obstack, struct c_label_context_vm);
7608 nstack->labels_def = NULL;
7609 nstack->labels_used = NULL;
7610 nstack->scope = scope;
7611 nstack->next = label_context_stack_vm;
7612 label_context_stack_vm = nstack;
7613 }
7614
7615 /* End a scope which may contain identifiers of variably modified
7616 type, scope number SCOPE. */
7617
7618 void
7619 c_end_vm_scope (unsigned int scope)
7620 {
7621 if (label_context_stack_vm == NULL)
7622 return;
7623 if (c_switch_stack && c_switch_stack->blocked_vm == scope)
7624 c_switch_stack->blocked_vm = 0;
7625 /* We may have a number of nested scopes of identifiers with
7626 variably modified type, all at this depth. Pop each in turn. */
7627 while (label_context_stack_vm->scope == scope)
7628 {
7629 struct c_label_list *dlist, *glist, *glist_prev = NULL;
7630
7631 /* It is no longer possible to jump to labels defined within this
7632 scope. */
7633 for (dlist = label_context_stack_vm->labels_def;
7634 dlist != NULL;
7635 dlist = dlist->next)
7636 {
7637 C_DECL_UNJUMPABLE_VM (dlist->label) = 1;
7638 }
7639 /* It is again possible to define labels with a goto just outside
7640 this scope. */
7641 for (glist = label_context_stack_vm->next->labels_used;
7642 glist != NULL;
7643 glist = glist->next)
7644 {
7645 C_DECL_UNDEFINABLE_VM (glist->label) = 0;
7646 glist_prev = glist;
7647 }
7648 if (glist_prev != NULL)
7649 glist_prev->next = label_context_stack_vm->labels_used;
7650 else
7651 label_context_stack_vm->next->labels_used
7652 = label_context_stack_vm->labels_used;
7653 label_context_stack_vm = label_context_stack_vm->next;
7654 }
7655 }
7656 \f
7657 /* Begin and end compound statements. This is as simple as pushing
7658 and popping new statement lists from the tree. */
7659
7660 tree
7661 c_begin_compound_stmt (bool do_scope)
7662 {
7663 tree stmt = push_stmt_list ();
7664 if (do_scope)
7665 push_scope ();
7666 return stmt;
7667 }
7668
7669 tree
7670 c_end_compound_stmt (tree stmt, bool do_scope)
7671 {
7672 tree block = NULL;
7673
7674 if (do_scope)
7675 {
7676 if (c_dialect_objc ())
7677 objc_clear_super_receiver ();
7678 block = pop_scope ();
7679 }
7680
7681 stmt = pop_stmt_list (stmt);
7682 stmt = c_build_bind_expr (block, stmt);
7683
7684 /* If this compound statement is nested immediately inside a statement
7685 expression, then force a BIND_EXPR to be created. Otherwise we'll
7686 do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular,
7687 STATEMENT_LISTs merge, and thus we can lose track of what statement
7688 was really last. */
7689 if (cur_stmt_list
7690 && STATEMENT_LIST_STMT_EXPR (cur_stmt_list)
7691 && TREE_CODE (stmt) != BIND_EXPR)
7692 {
7693 stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL);
7694 TREE_SIDE_EFFECTS (stmt) = 1;
7695 }
7696
7697 return stmt;
7698 }
7699
7700 /* Queue a cleanup. CLEANUP is an expression/statement to be executed
7701 when the current scope is exited. EH_ONLY is true when this is not
7702 meant to apply to normal control flow transfer. */
7703
7704 void
7705 push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only)
7706 {
7707 enum tree_code code;
7708 tree stmt, list;
7709 bool stmt_expr;
7710
7711 code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR;
7712 stmt = build_stmt (code, NULL, cleanup);
7713 add_stmt (stmt);
7714 stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list);
7715 list = push_stmt_list ();
7716 TREE_OPERAND (stmt, 0) = list;
7717 STATEMENT_LIST_STMT_EXPR (list) = stmt_expr;
7718 }
7719 \f
7720 /* Build a binary-operation expression without default conversions.
7721 CODE is the kind of expression to build.
7722 This function differs from `build' in several ways:
7723 the data type of the result is computed and recorded in it,
7724 warnings are generated if arg data types are invalid,
7725 special handling for addition and subtraction of pointers is known,
7726 and some optimization is done (operations on narrow ints
7727 are done in the narrower type when that gives the same result).
7728 Constant folding is also done before the result is returned.
7729
7730 Note that the operands will never have enumeral types, or function
7731 or array types, because either they will have the default conversions
7732 performed or they have both just been converted to some other type in which
7733 the arithmetic is to be done. */
7734
7735 tree
7736 build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1,
7737 int convert_p)
7738 {
7739 tree type0, type1;
7740 enum tree_code code0, code1;
7741 tree op0, op1;
7742 const char *invalid_op_diag;
7743
7744 /* Expression code to give to the expression when it is built.
7745 Normally this is CODE, which is what the caller asked for,
7746 but in some special cases we change it. */
7747 enum tree_code resultcode = code;
7748
7749 /* Data type in which the computation is to be performed.
7750 In the simplest cases this is the common type of the arguments. */
7751 tree result_type = NULL;
7752
7753 /* Nonzero means operands have already been type-converted
7754 in whatever way is necessary.
7755 Zero means they need to be converted to RESULT_TYPE. */
7756 int converted = 0;
7757
7758 /* Nonzero means create the expression with this type, rather than
7759 RESULT_TYPE. */
7760 tree build_type = 0;
7761
7762 /* Nonzero means after finally constructing the expression
7763 convert it to this type. */
7764 tree final_type = 0;
7765
7766 /* Nonzero if this is an operation like MIN or MAX which can
7767 safely be computed in short if both args are promoted shorts.
7768 Also implies COMMON.
7769 -1 indicates a bitwise operation; this makes a difference
7770 in the exact conditions for when it is safe to do the operation
7771 in a narrower mode. */
7772 int shorten = 0;
7773
7774 /* Nonzero if this is a comparison operation;
7775 if both args are promoted shorts, compare the original shorts.
7776 Also implies COMMON. */
7777 int short_compare = 0;
7778
7779 /* Nonzero if this is a right-shift operation, which can be computed on the
7780 original short and then promoted if the operand is a promoted short. */
7781 int short_shift = 0;
7782
7783 /* Nonzero means set RESULT_TYPE to the common type of the args. */
7784 int common = 0;
7785
7786 /* True means types are compatible as far as ObjC is concerned. */
7787 bool objc_ok;
7788
7789 if (convert_p)
7790 {
7791 op0 = default_conversion (orig_op0);
7792 op1 = default_conversion (orig_op1);
7793 }
7794 else
7795 {
7796 op0 = orig_op0;
7797 op1 = orig_op1;
7798 }
7799
7800 type0 = TREE_TYPE (op0);
7801 type1 = TREE_TYPE (op1);
7802
7803 /* The expression codes of the data types of the arguments tell us
7804 whether the arguments are integers, floating, pointers, etc. */
7805 code0 = TREE_CODE (type0);
7806 code1 = TREE_CODE (type1);
7807
7808 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
7809 STRIP_TYPE_NOPS (op0);
7810 STRIP_TYPE_NOPS (op1);
7811
7812 /* If an error was already reported for one of the arguments,
7813 avoid reporting another error. */
7814
7815 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
7816 return error_mark_node;
7817
7818 if ((invalid_op_diag
7819 = targetm.invalid_binary_op (code, type0, type1)))
7820 {
7821 error (invalid_op_diag);
7822 return error_mark_node;
7823 }
7824
7825 objc_ok = objc_compare_types (type0, type1, -3, NULL_TREE);
7826
7827 switch (code)
7828 {
7829 case PLUS_EXPR:
7830 /* Handle the pointer + int case. */
7831 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7832 return pointer_int_sum (PLUS_EXPR, op0, op1);
7833 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
7834 return pointer_int_sum (PLUS_EXPR, op1, op0);
7835 else
7836 common = 1;
7837 break;
7838
7839 case MINUS_EXPR:
7840 /* Subtraction of two similar pointers.
7841 We must subtract them as integers, then divide by object size. */
7842 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
7843 && comp_target_types (type0, type1))
7844 return pointer_diff (op0, op1);
7845 /* Handle pointer minus int. Just like pointer plus int. */
7846 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
7847 return pointer_int_sum (MINUS_EXPR, op0, op1);
7848 else
7849 common = 1;
7850 break;
7851
7852 case MULT_EXPR:
7853 common = 1;
7854 break;
7855
7856 case TRUNC_DIV_EXPR:
7857 case CEIL_DIV_EXPR:
7858 case FLOOR_DIV_EXPR:
7859 case ROUND_DIV_EXPR:
7860 case EXACT_DIV_EXPR:
7861 warn_for_div_by_zero (op1);
7862
7863 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
7864 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7865 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
7866 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
7867 {
7868 enum tree_code tcode0 = code0, tcode1 = code1;
7869
7870 if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
7871 tcode0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0)));
7872 if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)
7873 tcode1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1)));
7874
7875 if (!(tcode0 == INTEGER_TYPE && tcode1 == INTEGER_TYPE))
7876 resultcode = RDIV_EXPR;
7877 else
7878 /* Although it would be tempting to shorten always here, that
7879 loses on some targets, since the modulo instruction is
7880 undefined if the quotient can't be represented in the
7881 computation mode. We shorten only if unsigned or if
7882 dividing by something we know != -1. */
7883 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7884 || (TREE_CODE (op1) == INTEGER_CST
7885 && !integer_all_onesp (op1)));
7886 common = 1;
7887 }
7888 break;
7889
7890 case BIT_AND_EXPR:
7891 case BIT_IOR_EXPR:
7892 case BIT_XOR_EXPR:
7893 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7894 shorten = -1;
7895 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
7896 common = 1;
7897 break;
7898
7899 case TRUNC_MOD_EXPR:
7900 case FLOOR_MOD_EXPR:
7901 warn_for_div_by_zero (op1);
7902
7903 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7904 {
7905 /* Although it would be tempting to shorten always here, that loses
7906 on some targets, since the modulo instruction is undefined if the
7907 quotient can't be represented in the computation mode. We shorten
7908 only if unsigned or if dividing by something we know != -1. */
7909 shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0))
7910 || (TREE_CODE (op1) == INTEGER_CST
7911 && !integer_all_onesp (op1)));
7912 common = 1;
7913 }
7914 break;
7915
7916 case TRUTH_ANDIF_EXPR:
7917 case TRUTH_ORIF_EXPR:
7918 case TRUTH_AND_EXPR:
7919 case TRUTH_OR_EXPR:
7920 case TRUTH_XOR_EXPR:
7921 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
7922 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
7923 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
7924 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
7925 {
7926 /* Result of these operations is always an int,
7927 but that does not mean the operands should be
7928 converted to ints! */
7929 result_type = integer_type_node;
7930 op0 = c_common_truthvalue_conversion (op0);
7931 op1 = c_common_truthvalue_conversion (op1);
7932 converted = 1;
7933 }
7934 break;
7935
7936 /* Shift operations: result has same type as first operand;
7937 always convert second operand to int.
7938 Also set SHORT_SHIFT if shifting rightward. */
7939
7940 case RSHIFT_EXPR:
7941 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7942 {
7943 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7944 {
7945 if (tree_int_cst_sgn (op1) < 0)
7946 warning (0, "right shift count is negative");
7947 else
7948 {
7949 if (!integer_zerop (op1))
7950 short_shift = 1;
7951
7952 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7953 warning (0, "right shift count >= width of type");
7954 }
7955 }
7956
7957 /* Use the type of the value to be shifted. */
7958 result_type = type0;
7959 /* Convert the shift-count to an integer, regardless of size
7960 of value being shifted. */
7961 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7962 op1 = convert (integer_type_node, op1);
7963 /* Avoid converting op1 to result_type later. */
7964 converted = 1;
7965 }
7966 break;
7967
7968 case LSHIFT_EXPR:
7969 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
7970 {
7971 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
7972 {
7973 if (tree_int_cst_sgn (op1) < 0)
7974 warning (0, "left shift count is negative");
7975
7976 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
7977 warning (0, "left shift count >= width of type");
7978 }
7979
7980 /* Use the type of the value to be shifted. */
7981 result_type = type0;
7982 /* Convert the shift-count to an integer, regardless of size
7983 of value being shifted. */
7984 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
7985 op1 = convert (integer_type_node, op1);
7986 /* Avoid converting op1 to result_type later. */
7987 converted = 1;
7988 }
7989 break;
7990
7991 case EQ_EXPR:
7992 case NE_EXPR:
7993 if (code0 == REAL_TYPE || code1 == REAL_TYPE)
7994 warning (OPT_Wfloat_equal,
7995 "comparing floating point with == or != is unsafe");
7996 /* Result of comparison is always int,
7997 but don't convert the args to int! */
7998 build_type = integer_type_node;
7999 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
8000 || code0 == COMPLEX_TYPE)
8001 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
8002 || code1 == COMPLEX_TYPE))
8003 short_compare = 1;
8004 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8005 {
8006 tree tt0 = TREE_TYPE (type0);
8007 tree tt1 = TREE_TYPE (type1);
8008 /* Anything compares with void *. void * compares with anything.
8009 Otherwise, the targets must be compatible
8010 and both must be object or both incomplete. */
8011 if (comp_target_types (type0, type1))
8012 result_type = common_pointer_type (type0, type1);
8013 else if (VOID_TYPE_P (tt0))
8014 {
8015 /* op0 != orig_op0 detects the case of something
8016 whose value is 0 but which isn't a valid null ptr const. */
8017 if (pedantic && !null_pointer_constant_p (orig_op0)
8018 && TREE_CODE (tt1) == FUNCTION_TYPE)
8019 pedwarn ("ISO C forbids comparison of %<void *%>"
8020 " with function pointer");
8021 }
8022 else if (VOID_TYPE_P (tt1))
8023 {
8024 if (pedantic && !null_pointer_constant_p (orig_op1)
8025 && TREE_CODE (tt0) == FUNCTION_TYPE)
8026 pedwarn ("ISO C forbids comparison of %<void *%>"
8027 " with function pointer");
8028 }
8029 else
8030 /* Avoid warning about the volatile ObjC EH puts on decls. */
8031 if (!objc_ok)
8032 pedwarn ("comparison of distinct pointer types lacks a cast");
8033
8034 if (result_type == NULL_TREE)
8035 result_type = ptr_type_node;
8036 }
8037 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8038 {
8039 if (TREE_CODE (op0) == ADDR_EXPR
8040 && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
8041 warning (OPT_Waddress, "the address of %qD will never be NULL",
8042 TREE_OPERAND (op0, 0));
8043 result_type = type0;
8044 }
8045 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8046 {
8047 if (TREE_CODE (op1) == ADDR_EXPR
8048 && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
8049 warning (OPT_Waddress, "the address of %qD will never be NULL",
8050 TREE_OPERAND (op1, 0));
8051 result_type = type1;
8052 }
8053 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8054 {
8055 result_type = type0;
8056 pedwarn ("comparison between pointer and integer");
8057 }
8058 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8059 {
8060 result_type = type1;
8061 pedwarn ("comparison between pointer and integer");
8062 }
8063 break;
8064
8065 case LE_EXPR:
8066 case GE_EXPR:
8067 case LT_EXPR:
8068 case GT_EXPR:
8069 build_type = integer_type_node;
8070 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
8071 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
8072 short_compare = 1;
8073 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
8074 {
8075 if (comp_target_types (type0, type1))
8076 {
8077 result_type = common_pointer_type (type0, type1);
8078 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
8079 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
8080 pedwarn ("comparison of complete and incomplete pointers");
8081 else if (pedantic
8082 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
8083 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
8084 }
8085 else
8086 {
8087 result_type = ptr_type_node;
8088 pedwarn ("comparison of distinct pointer types lacks a cast");
8089 }
8090 }
8091 else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
8092 {
8093 result_type = type0;
8094 if (pedantic || extra_warnings)
8095 pedwarn ("ordered comparison of pointer with integer zero");
8096 }
8097 else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
8098 {
8099 result_type = type1;
8100 if (pedantic)
8101 pedwarn ("ordered comparison of pointer with integer zero");
8102 }
8103 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
8104 {
8105 result_type = type0;
8106 pedwarn ("comparison between pointer and integer");
8107 }
8108 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
8109 {
8110 result_type = type1;
8111 pedwarn ("comparison between pointer and integer");
8112 }
8113 break;
8114
8115 default:
8116 gcc_unreachable ();
8117 }
8118
8119 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
8120 return error_mark_node;
8121
8122 if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE
8123 && (!tree_int_cst_equal (TYPE_SIZE (type0), TYPE_SIZE (type1))
8124 || !same_scalar_type_ignoring_signedness (TREE_TYPE (type0),
8125 TREE_TYPE (type1))))
8126 {
8127 binary_op_error (code, type0, type1);
8128 return error_mark_node;
8129 }
8130
8131 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
8132 || code0 == VECTOR_TYPE)
8133 &&
8134 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
8135 || code1 == VECTOR_TYPE))
8136 {
8137 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
8138
8139 if (shorten || common || short_compare)
8140 {
8141 result_type = c_common_type (type0, type1);
8142 if (result_type == error_mark_node)
8143 return error_mark_node;
8144 }
8145
8146 /* For certain operations (which identify themselves by shorten != 0)
8147 if both args were extended from the same smaller type,
8148 do the arithmetic in that type and then extend.
8149
8150 shorten !=0 and !=1 indicates a bitwise operation.
8151 For them, this optimization is safe only if
8152 both args are zero-extended or both are sign-extended.
8153 Otherwise, we might change the result.
8154 Eg, (short)-1 | (unsigned short)-1 is (int)-1
8155 but calculated in (unsigned short) it would be (unsigned short)-1. */
8156
8157 if (shorten && none_complex)
8158 {
8159 int unsigned0, unsigned1;
8160 tree arg0, arg1;
8161 int uns;
8162 tree type;
8163
8164 /* Cast OP0 and OP1 to RESULT_TYPE. Doing so prevents
8165 excessive narrowing when we call get_narrower below. For
8166 example, suppose that OP0 is of unsigned int extended
8167 from signed char and that RESULT_TYPE is long long int.
8168 If we explicitly cast OP0 to RESULT_TYPE, OP0 would look
8169 like
8170
8171 (long long int) (unsigned int) signed_char
8172
8173 which get_narrower would narrow down to
8174
8175 (unsigned int) signed char
8176
8177 If we do not cast OP0 first, get_narrower would return
8178 signed_char, which is inconsistent with the case of the
8179 explicit cast. */
8180 op0 = convert (result_type, op0);
8181 op1 = convert (result_type, op1);
8182
8183 arg0 = get_narrower (op0, &unsigned0);
8184 arg1 = get_narrower (op1, &unsigned1);
8185
8186 /* UNS is 1 if the operation to be done is an unsigned one. */
8187 uns = TYPE_UNSIGNED (result_type);
8188
8189 final_type = result_type;
8190
8191 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
8192 but it *requires* conversion to FINAL_TYPE. */
8193
8194 if ((TYPE_PRECISION (TREE_TYPE (op0))
8195 == TYPE_PRECISION (TREE_TYPE (arg0)))
8196 && TREE_TYPE (op0) != final_type)
8197 unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0));
8198 if ((TYPE_PRECISION (TREE_TYPE (op1))
8199 == TYPE_PRECISION (TREE_TYPE (arg1)))
8200 && TREE_TYPE (op1) != final_type)
8201 unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1));
8202
8203 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
8204
8205 /* For bitwise operations, signedness of nominal type
8206 does not matter. Consider only how operands were extended. */
8207 if (shorten == -1)
8208 uns = unsigned0;
8209
8210 /* Note that in all three cases below we refrain from optimizing
8211 an unsigned operation on sign-extended args.
8212 That would not be valid. */
8213
8214 /* Both args variable: if both extended in same way
8215 from same width, do it in that width.
8216 Do it unsigned if args were zero-extended. */
8217 if ((TYPE_PRECISION (TREE_TYPE (arg0))
8218 < TYPE_PRECISION (result_type))
8219 && (TYPE_PRECISION (TREE_TYPE (arg1))
8220 == TYPE_PRECISION (TREE_TYPE (arg0)))
8221 && unsigned0 == unsigned1
8222 && (unsigned0 || !uns))
8223 result_type
8224 = c_common_signed_or_unsigned_type
8225 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
8226 else if (TREE_CODE (arg0) == INTEGER_CST
8227 && (unsigned1 || !uns)
8228 && (TYPE_PRECISION (TREE_TYPE (arg1))
8229 < TYPE_PRECISION (result_type))
8230 && (type
8231 = c_common_signed_or_unsigned_type (unsigned1,
8232 TREE_TYPE (arg1)))
8233 && !POINTER_TYPE_P (type)
8234 && int_fits_type_p (arg0, type))
8235 result_type = type;
8236 else if (TREE_CODE (arg1) == INTEGER_CST
8237 && (unsigned0 || !uns)
8238 && (TYPE_PRECISION (TREE_TYPE (arg0))
8239 < TYPE_PRECISION (result_type))
8240 && (type
8241 = c_common_signed_or_unsigned_type (unsigned0,
8242 TREE_TYPE (arg0)))
8243 && !POINTER_TYPE_P (type)
8244 && int_fits_type_p (arg1, type))
8245 result_type = type;
8246 }
8247
8248 /* Shifts can be shortened if shifting right. */
8249
8250 if (short_shift)
8251 {
8252 int unsigned_arg;
8253 tree arg0 = get_narrower (op0, &unsigned_arg);
8254
8255 final_type = result_type;
8256
8257 if (arg0 == op0 && final_type == TREE_TYPE (op0))
8258 unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0));
8259
8260 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
8261 /* We can shorten only if the shift count is less than the
8262 number of bits in the smaller type size. */
8263 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
8264 /* We cannot drop an unsigned shift after sign-extension. */
8265 && (!TYPE_UNSIGNED (final_type) || unsigned_arg))
8266 {
8267 /* Do an unsigned shift if the operand was zero-extended. */
8268 result_type
8269 = c_common_signed_or_unsigned_type (unsigned_arg,
8270 TREE_TYPE (arg0));
8271 /* Convert value-to-be-shifted to that type. */
8272 if (TREE_TYPE (op0) != result_type)
8273 op0 = convert (result_type, op0);
8274 converted = 1;
8275 }
8276 }
8277
8278 /* Comparison operations are shortened too but differently.
8279 They identify themselves by setting short_compare = 1. */
8280
8281 if (short_compare)
8282 {
8283 /* Don't write &op0, etc., because that would prevent op0
8284 from being kept in a register.
8285 Instead, make copies of the our local variables and
8286 pass the copies by reference, then copy them back afterward. */
8287 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
8288 enum tree_code xresultcode = resultcode;
8289 tree val
8290 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
8291
8292 if (val != 0)
8293 return val;
8294
8295 op0 = xop0, op1 = xop1;
8296 converted = 1;
8297 resultcode = xresultcode;
8298
8299 if (warn_sign_compare && skip_evaluation == 0)
8300 {
8301 int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0));
8302 int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1));
8303 int unsignedp0, unsignedp1;
8304 tree primop0 = get_narrower (op0, &unsignedp0);
8305 tree primop1 = get_narrower (op1, &unsignedp1);
8306
8307 xop0 = orig_op0;
8308 xop1 = orig_op1;
8309 STRIP_TYPE_NOPS (xop0);
8310 STRIP_TYPE_NOPS (xop1);
8311
8312 /* Give warnings for comparisons between signed and unsigned
8313 quantities that may fail.
8314
8315 Do the checking based on the original operand trees, so that
8316 casts will be considered, but default promotions won't be.
8317
8318 Do not warn if the comparison is being done in a signed type,
8319 since the signed type will only be chosen if it can represent
8320 all the values of the unsigned type. */
8321 if (!TYPE_UNSIGNED (result_type))
8322 /* OK */;
8323 /* Do not warn if both operands are the same signedness. */
8324 else if (op0_signed == op1_signed)
8325 /* OK */;
8326 else
8327 {
8328 tree sop, uop;
8329 bool ovf;
8330
8331 if (op0_signed)
8332 sop = xop0, uop = xop1;
8333 else
8334 sop = xop1, uop = xop0;
8335
8336 /* Do not warn if the signed quantity is an
8337 unsuffixed integer literal (or some static
8338 constant expression involving such literals or a
8339 conditional expression involving such literals)
8340 and it is non-negative. */
8341 if (tree_expr_nonnegative_warnv_p (sop, &ovf))
8342 /* OK */;
8343 /* Do not warn if the comparison is an equality operation,
8344 the unsigned quantity is an integral constant, and it
8345 would fit in the result if the result were signed. */
8346 else if (TREE_CODE (uop) == INTEGER_CST
8347 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
8348 && int_fits_type_p
8349 (uop, c_common_signed_type (result_type)))
8350 /* OK */;
8351 /* Do not warn if the unsigned quantity is an enumeration
8352 constant and its maximum value would fit in the result
8353 if the result were signed. */
8354 else if (TREE_CODE (uop) == INTEGER_CST
8355 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
8356 && int_fits_type_p
8357 (TYPE_MAX_VALUE (TREE_TYPE (uop)),
8358 c_common_signed_type (result_type)))
8359 /* OK */;
8360 else
8361 warning (0, "comparison between signed and unsigned");
8362 }
8363
8364 /* Warn if two unsigned values are being compared in a size
8365 larger than their original size, and one (and only one) is the
8366 result of a `~' operator. This comparison will always fail.
8367
8368 Also warn if one operand is a constant, and the constant
8369 does not have all bits set that are set in the ~ operand
8370 when it is extended. */
8371
8372 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
8373 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
8374 {
8375 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
8376 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
8377 &unsignedp0);
8378 else
8379 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
8380 &unsignedp1);
8381
8382 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
8383 {
8384 tree primop;
8385 HOST_WIDE_INT constant, mask;
8386 int unsignedp, bits;
8387
8388 if (host_integerp (primop0, 0))
8389 {
8390 primop = primop1;
8391 unsignedp = unsignedp1;
8392 constant = tree_low_cst (primop0, 0);
8393 }
8394 else
8395 {
8396 primop = primop0;
8397 unsignedp = unsignedp0;
8398 constant = tree_low_cst (primop1, 0);
8399 }
8400
8401 bits = TYPE_PRECISION (TREE_TYPE (primop));
8402 if (bits < TYPE_PRECISION (result_type)
8403 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
8404 {
8405 mask = (~(HOST_WIDE_INT) 0) << bits;
8406 if ((mask & constant) != mask)
8407 warning (0, "comparison of promoted ~unsigned with constant");
8408 }
8409 }
8410 else if (unsignedp0 && unsignedp1
8411 && (TYPE_PRECISION (TREE_TYPE (primop0))
8412 < TYPE_PRECISION (result_type))
8413 && (TYPE_PRECISION (TREE_TYPE (primop1))
8414 < TYPE_PRECISION (result_type)))
8415 warning (0, "comparison of promoted ~unsigned with unsigned");
8416 }
8417 }
8418 }
8419 }
8420
8421 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
8422 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
8423 Then the expression will be built.
8424 It will be given type FINAL_TYPE if that is nonzero;
8425 otherwise, it will be given type RESULT_TYPE. */
8426
8427 if (!result_type)
8428 {
8429 binary_op_error (code, TREE_TYPE (op0), TREE_TYPE (op1));
8430 return error_mark_node;
8431 }
8432
8433 if (!converted)
8434 {
8435 if (TREE_TYPE (op0) != result_type)
8436 op0 = convert_and_check (result_type, op0);
8437 if (TREE_TYPE (op1) != result_type)
8438 op1 = convert_and_check (result_type, op1);
8439
8440 /* This can happen if one operand has a vector type, and the other
8441 has a different type. */
8442 if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK)
8443 return error_mark_node;
8444 }
8445
8446 if (build_type == NULL_TREE)
8447 build_type = result_type;
8448
8449 {
8450 /* Treat expressions in initializers specially as they can't trap. */
8451 tree result = require_constant_value ? fold_build2_initializer (resultcode,
8452 build_type,
8453 op0, op1)
8454 : fold_build2 (resultcode, build_type,
8455 op0, op1);
8456
8457 if (final_type != 0)
8458 result = convert (final_type, result);
8459 return result;
8460 }
8461 }
8462
8463
8464 /* Convert EXPR to be a truth-value, validating its type for this
8465 purpose. */
8466
8467 tree
8468 c_objc_common_truthvalue_conversion (tree expr)
8469 {
8470 switch (TREE_CODE (TREE_TYPE (expr)))
8471 {
8472 case ARRAY_TYPE:
8473 error ("used array that cannot be converted to pointer where scalar is required");
8474 return error_mark_node;
8475
8476 case RECORD_TYPE:
8477 error ("used struct type value where scalar is required");
8478 return error_mark_node;
8479
8480 case UNION_TYPE:
8481 error ("used union type value where scalar is required");
8482 return error_mark_node;
8483
8484 case FUNCTION_TYPE:
8485 gcc_unreachable ();
8486
8487 default:
8488 break;
8489 }
8490
8491 /* ??? Should we also give an error for void and vectors rather than
8492 leaving those to give errors later? */
8493 return c_common_truthvalue_conversion (expr);
8494 }
8495 \f
8496
8497 /* Convert EXPR to a contained DECL, updating *TC, *TI and *SE as
8498 required. */
8499
8500 tree
8501 c_expr_to_decl (tree expr, bool *tc ATTRIBUTE_UNUSED,
8502 bool *ti ATTRIBUTE_UNUSED, bool *se)
8503 {
8504 if (TREE_CODE (expr) == COMPOUND_LITERAL_EXPR)
8505 {
8506 tree decl = COMPOUND_LITERAL_EXPR_DECL (expr);
8507 /* Executing a compound literal inside a function reinitializes
8508 it. */
8509 if (!TREE_STATIC (decl))
8510 *se = true;
8511 return decl;
8512 }
8513 else
8514 return expr;
8515 }
8516 \f
8517 /* Like c_begin_compound_stmt, except force the retention of the BLOCK. */
8518
8519 tree
8520 c_begin_omp_parallel (void)
8521 {
8522 tree block;
8523
8524 keep_next_level ();
8525 block = c_begin_compound_stmt (true);
8526
8527 return block;
8528 }
8529
8530 tree
8531 c_finish_omp_parallel (tree clauses, tree block)
8532 {
8533 tree stmt;
8534
8535 block = c_end_compound_stmt (block, true);
8536
8537 stmt = make_node (OMP_PARALLEL);
8538 TREE_TYPE (stmt) = void_type_node;
8539 OMP_PARALLEL_CLAUSES (stmt) = clauses;
8540 OMP_PARALLEL_BODY (stmt) = block;
8541
8542 return add_stmt (stmt);
8543 }
8544
8545 /* For all elements of CLAUSES, validate them vs OpenMP constraints.
8546 Remove any elements from the list that are invalid. */
8547
8548 tree
8549 c_finish_omp_clauses (tree clauses)
8550 {
8551 bitmap_head generic_head, firstprivate_head, lastprivate_head;
8552 tree c, t, *pc = &clauses;
8553 const char *name;
8554
8555 bitmap_obstack_initialize (NULL);
8556 bitmap_initialize (&generic_head, &bitmap_default_obstack);
8557 bitmap_initialize (&firstprivate_head, &bitmap_default_obstack);
8558 bitmap_initialize (&lastprivate_head, &bitmap_default_obstack);
8559
8560 for (pc = &clauses, c = clauses; c ; c = *pc)
8561 {
8562 bool remove = false;
8563 bool need_complete = false;
8564 bool need_implicitly_determined = false;
8565
8566 switch (OMP_CLAUSE_CODE (c))
8567 {
8568 case OMP_CLAUSE_SHARED:
8569 name = "shared";
8570 need_implicitly_determined = true;
8571 goto check_dup_generic;
8572
8573 case OMP_CLAUSE_PRIVATE:
8574 name = "private";
8575 need_complete = true;
8576 need_implicitly_determined = true;
8577 goto check_dup_generic;
8578
8579 case OMP_CLAUSE_REDUCTION:
8580 name = "reduction";
8581 need_implicitly_determined = true;
8582 t = OMP_CLAUSE_DECL (c);
8583 if (AGGREGATE_TYPE_P (TREE_TYPE (t))
8584 || POINTER_TYPE_P (TREE_TYPE (t)))
8585 {
8586 error ("%qE has invalid type for %<reduction%>", t);
8587 remove = true;
8588 }
8589 else if (FLOAT_TYPE_P (TREE_TYPE (t)))
8590 {
8591 enum tree_code r_code = OMP_CLAUSE_REDUCTION_CODE (c);
8592 const char *r_name = NULL;
8593
8594 switch (r_code)
8595 {
8596 case PLUS_EXPR:
8597 case MULT_EXPR:
8598 case MINUS_EXPR:
8599 break;
8600 case BIT_AND_EXPR:
8601 r_name = "&";
8602 break;
8603 case BIT_XOR_EXPR:
8604 r_name = "^";
8605 break;
8606 case BIT_IOR_EXPR:
8607 r_name = "|";
8608 break;
8609 case TRUTH_ANDIF_EXPR:
8610 r_name = "&&";
8611 break;
8612 case TRUTH_ORIF_EXPR:
8613 r_name = "||";
8614 break;
8615 default:
8616 gcc_unreachable ();
8617 }
8618 if (r_name)
8619 {
8620 error ("%qE has invalid type for %<reduction(%s)%>",
8621 t, r_name);
8622 remove = true;
8623 }
8624 }
8625 goto check_dup_generic;
8626
8627 case OMP_CLAUSE_COPYPRIVATE:
8628 name = "copyprivate";
8629 goto check_dup_generic;
8630
8631 case OMP_CLAUSE_COPYIN:
8632 name = "copyin";
8633 t = OMP_CLAUSE_DECL (c);
8634 if (TREE_CODE (t) != VAR_DECL || !DECL_THREAD_LOCAL_P (t))
8635 {
8636 error ("%qE must be %<threadprivate%> for %<copyin%>", t);
8637 remove = true;
8638 }
8639 goto check_dup_generic;
8640
8641 check_dup_generic:
8642 t = OMP_CLAUSE_DECL (c);
8643 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8644 {
8645 error ("%qE is not a variable in clause %qs", t, name);
8646 remove = true;
8647 }
8648 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8649 || bitmap_bit_p (&firstprivate_head, DECL_UID (t))
8650 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8651 {
8652 error ("%qE appears more than once in data clauses", t);
8653 remove = true;
8654 }
8655 else
8656 bitmap_set_bit (&generic_head, DECL_UID (t));
8657 break;
8658
8659 case OMP_CLAUSE_FIRSTPRIVATE:
8660 name = "firstprivate";
8661 t = OMP_CLAUSE_DECL (c);
8662 need_complete = true;
8663 need_implicitly_determined = true;
8664 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8665 {
8666 error ("%qE is not a variable in clause %<firstprivate%>", t);
8667 remove = true;
8668 }
8669 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8670 || bitmap_bit_p (&firstprivate_head, DECL_UID (t)))
8671 {
8672 error ("%qE appears more than once in data clauses", t);
8673 remove = true;
8674 }
8675 else
8676 bitmap_set_bit (&firstprivate_head, DECL_UID (t));
8677 break;
8678
8679 case OMP_CLAUSE_LASTPRIVATE:
8680 name = "lastprivate";
8681 t = OMP_CLAUSE_DECL (c);
8682 need_complete = true;
8683 need_implicitly_determined = true;
8684 if (TREE_CODE (t) != VAR_DECL && TREE_CODE (t) != PARM_DECL)
8685 {
8686 error ("%qE is not a variable in clause %<lastprivate%>", t);
8687 remove = true;
8688 }
8689 else if (bitmap_bit_p (&generic_head, DECL_UID (t))
8690 || bitmap_bit_p (&lastprivate_head, DECL_UID (t)))
8691 {
8692 error ("%qE appears more than once in data clauses", t);
8693 remove = true;
8694 }
8695 else
8696 bitmap_set_bit (&lastprivate_head, DECL_UID (t));
8697 break;
8698
8699 case OMP_CLAUSE_IF:
8700 case OMP_CLAUSE_NUM_THREADS:
8701 case OMP_CLAUSE_SCHEDULE:
8702 case OMP_CLAUSE_NOWAIT:
8703 case OMP_CLAUSE_ORDERED:
8704 case OMP_CLAUSE_DEFAULT:
8705 pc = &OMP_CLAUSE_CHAIN (c);
8706 continue;
8707
8708 default:
8709 gcc_unreachable ();
8710 }
8711
8712 if (!remove)
8713 {
8714 t = OMP_CLAUSE_DECL (c);
8715
8716 if (need_complete)
8717 {
8718 t = require_complete_type (t);
8719 if (t == error_mark_node)
8720 remove = true;
8721 }
8722
8723 if (need_implicitly_determined)
8724 {
8725 const char *share_name = NULL;
8726
8727 if (TREE_CODE (t) == VAR_DECL && DECL_THREAD_LOCAL_P (t))
8728 share_name = "threadprivate";
8729 else switch (c_omp_predetermined_sharing (t))
8730 {
8731 case OMP_CLAUSE_DEFAULT_UNSPECIFIED:
8732 break;
8733 case OMP_CLAUSE_DEFAULT_SHARED:
8734 share_name = "shared";
8735 break;
8736 case OMP_CLAUSE_DEFAULT_PRIVATE:
8737 share_name = "private";
8738 break;
8739 default:
8740 gcc_unreachable ();
8741 }
8742 if (share_name)
8743 {
8744 error ("%qE is predetermined %qs for %qs",
8745 t, share_name, name);
8746 remove = true;
8747 }
8748 }
8749 }
8750
8751 if (remove)
8752 *pc = OMP_CLAUSE_CHAIN (c);
8753 else
8754 pc = &OMP_CLAUSE_CHAIN (c);
8755 }
8756
8757 bitmap_obstack_release (NULL);
8758 return clauses;
8759 }