i386-protos.h (x86_emit_floatuns): Declare.
[official-gcc.git] / gcc / c-typeck.c
blobbbd94a044fafba5b26f9bffa148d13e638f7b882
1 /* Build expressions with type checking for C compiler.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
10 version.
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
20 02111-1307, USA. */
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.
28 There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
29 and to process initializations in declarations (since they work
30 like a strange sort of assignment). */
32 #include "config.h"
33 #include "system.h"
34 #include "coretypes.h"
35 #include "tm.h"
36 #include "rtl.h"
37 #include "tree.h"
38 #include "c-tree.h"
39 #include "tm_p.h"
40 #include "flags.h"
41 #include "output.h"
42 #include "expr.h"
43 #include "toplev.h"
44 #include "intl.h"
45 #include "ggc.h"
46 #include "target.h"
48 /* Nonzero if we've already printed a "missing braces around initializer"
49 message within this initializer. */
50 static int missing_braces_mentioned;
52 /* 1 if we explained undeclared var errors. */
53 static int undeclared_variable_notice;
55 static tree qualify_type PARAMS ((tree, tree));
56 static int comp_target_types PARAMS ((tree, tree, int));
57 static int function_types_compatible_p PARAMS ((tree, tree));
58 static int type_lists_compatible_p PARAMS ((tree, tree));
59 static tree decl_constant_value_for_broken_optimization PARAMS ((tree));
60 static tree default_function_array_conversion PARAMS ((tree));
61 static tree lookup_field PARAMS ((tree, tree));
62 static tree convert_arguments PARAMS ((tree, tree, tree, tree));
63 static tree pointer_diff PARAMS ((tree, tree));
64 static tree unary_complex_lvalue PARAMS ((enum tree_code, tree, int));
65 static void pedantic_lvalue_warning PARAMS ((enum tree_code));
66 static tree internal_build_compound_expr PARAMS ((tree, int));
67 static tree convert_for_assignment PARAMS ((tree, tree, const char *,
68 tree, tree, int));
69 static void warn_for_assignment PARAMS ((const char *, const char *,
70 tree, int));
71 static tree valid_compound_expr_initializer PARAMS ((tree, tree));
72 static void push_string PARAMS ((const char *));
73 static void push_member_name PARAMS ((tree));
74 static void push_array_bounds PARAMS ((int));
75 static int spelling_length PARAMS ((void));
76 static char *print_spelling PARAMS ((char *));
77 static void warning_init PARAMS ((const char *));
78 static tree digest_init PARAMS ((tree, tree, int));
79 static void output_init_element PARAMS ((tree, tree, tree, int));
80 static void output_pending_init_elements PARAMS ((int));
81 static int set_designator PARAMS ((int));
82 static void push_range_stack PARAMS ((tree));
83 static void add_pending_init PARAMS ((tree, tree));
84 static void set_nonincremental_init PARAMS ((void));
85 static void set_nonincremental_init_from_string PARAMS ((tree));
86 static tree find_init_member PARAMS ((tree));
88 /* Do `exp = require_complete_type (exp);' to make sure exp
89 does not have an incomplete type. (That includes void types.) */
91 tree
92 require_complete_type (value)
93 tree value;
95 tree type = TREE_TYPE (value);
97 if (value == error_mark_node || type == error_mark_node)
98 return error_mark_node;
100 /* First, detect a valid value with a complete type. */
101 if (COMPLETE_TYPE_P (type))
102 return value;
104 c_incomplete_type_error (value, type);
105 return error_mark_node;
108 /* Print an error message for invalid use of an incomplete type.
109 VALUE is the expression that was used (or 0 if that isn't known)
110 and TYPE is the type that was invalid. */
112 void
113 c_incomplete_type_error (value, type)
114 tree value;
115 tree type;
117 const char *type_code_string;
119 /* Avoid duplicate error message. */
120 if (TREE_CODE (type) == ERROR_MARK)
121 return;
123 if (value != 0 && (TREE_CODE (value) == VAR_DECL
124 || TREE_CODE (value) == PARM_DECL))
125 error ("`%s' has an incomplete type",
126 IDENTIFIER_POINTER (DECL_NAME (value)));
127 else
129 retry:
130 /* We must print an error message. Be clever about what it says. */
132 switch (TREE_CODE (type))
134 case RECORD_TYPE:
135 type_code_string = "struct";
136 break;
138 case UNION_TYPE:
139 type_code_string = "union";
140 break;
142 case ENUMERAL_TYPE:
143 type_code_string = "enum";
144 break;
146 case VOID_TYPE:
147 error ("invalid use of void expression");
148 return;
150 case ARRAY_TYPE:
151 if (TYPE_DOMAIN (type))
153 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
155 error ("invalid use of flexible array member");
156 return;
158 type = TREE_TYPE (type);
159 goto retry;
161 error ("invalid use of array with unspecified bounds");
162 return;
164 default:
165 abort ();
168 if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
169 error ("invalid use of undefined type `%s %s'",
170 type_code_string, IDENTIFIER_POINTER (TYPE_NAME (type)));
171 else
172 /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
173 error ("invalid use of incomplete typedef `%s'",
174 IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))));
178 /* Given a type, apply default promotions wrt unnamed function
179 arguments and return the new type. */
181 tree
182 c_type_promotes_to (type)
183 tree type;
185 if (TYPE_MAIN_VARIANT (type) == float_type_node)
186 return double_type_node;
188 if (c_promoting_integer_type_p (type))
190 /* Preserve unsignedness if not really getting any wider. */
191 if (TREE_UNSIGNED (type)
192 && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
193 return unsigned_type_node;
194 return integer_type_node;
197 return type;
200 /* Return a variant of TYPE which has all the type qualifiers of LIKE
201 as well as those of TYPE. */
203 static tree
204 qualify_type (type, like)
205 tree type, like;
207 return c_build_qualified_type (type,
208 TYPE_QUALS (type) | TYPE_QUALS (like));
211 /* Return the common type of two types.
212 We assume that comptypes has already been done and returned 1;
213 if that isn't so, this may crash. In particular, we assume that qualifiers
214 match.
216 This is the type for the result of most arithmetic operations
217 if the operands have the given two types. */
219 tree
220 common_type (t1, t2)
221 tree t1, t2;
223 enum tree_code code1;
224 enum tree_code code2;
225 tree attributes;
227 /* Save time if the two types are the same. */
229 if (t1 == t2) return t1;
231 /* If one type is nonsense, use the other. */
232 if (t1 == error_mark_node)
233 return t2;
234 if (t2 == error_mark_node)
235 return t1;
237 /* Merge the attributes. */
238 attributes = (*targetm.merge_type_attributes) (t1, t2);
240 /* Treat an enum type as the unsigned integer type of the same width. */
242 if (TREE_CODE (t1) == ENUMERAL_TYPE)
243 t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
244 if (TREE_CODE (t2) == ENUMERAL_TYPE)
245 t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
247 code1 = TREE_CODE (t1);
248 code2 = TREE_CODE (t2);
250 /* If one type is complex, form the common type of the non-complex
251 components, then make that complex. Use T1 or T2 if it is the
252 required type. */
253 if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
255 tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
256 tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
257 tree subtype = common_type (subtype1, subtype2);
259 if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
260 return build_type_attribute_variant (t1, attributes);
261 else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
262 return build_type_attribute_variant (t2, attributes);
263 else
264 return build_type_attribute_variant (build_complex_type (subtype),
265 attributes);
268 switch (code1)
270 case INTEGER_TYPE:
271 case REAL_TYPE:
272 /* If only one is real, use it as the result. */
274 if (code1 == REAL_TYPE && code2 != REAL_TYPE)
275 return build_type_attribute_variant (t1, attributes);
277 if (code2 == REAL_TYPE && code1 != REAL_TYPE)
278 return build_type_attribute_variant (t2, attributes);
280 /* Both real or both integers; use the one with greater precision. */
282 if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
283 return build_type_attribute_variant (t1, attributes);
284 else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
285 return build_type_attribute_variant (t2, attributes);
287 /* Same precision. Prefer longs to ints even when same size. */
289 if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
290 || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
291 return build_type_attribute_variant (long_unsigned_type_node,
292 attributes);
294 if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
295 || TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
297 /* But preserve unsignedness from the other type,
298 since long cannot hold all the values of an unsigned int. */
299 if (TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
300 t1 = long_unsigned_type_node;
301 else
302 t1 = long_integer_type_node;
303 return build_type_attribute_variant (t1, attributes);
306 /* Likewise, prefer long double to double even if same size. */
307 if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
308 || TYPE_MAIN_VARIANT (t2) == long_double_type_node)
309 return build_type_attribute_variant (long_double_type_node,
310 attributes);
312 /* Otherwise prefer the unsigned one. */
314 if (TREE_UNSIGNED (t1))
315 return build_type_attribute_variant (t1, attributes);
316 else
317 return build_type_attribute_variant (t2, attributes);
319 case POINTER_TYPE:
320 /* For two pointers, do this recursively on the target type,
321 and combine the qualifiers of the two types' targets. */
322 /* This code was turned off; I don't know why.
323 But ANSI C specifies doing this with the qualifiers.
324 So I turned it on again. */
326 tree pointed_to_1 = TREE_TYPE (t1);
327 tree pointed_to_2 = TREE_TYPE (t2);
328 tree target = common_type (TYPE_MAIN_VARIANT (pointed_to_1),
329 TYPE_MAIN_VARIANT (pointed_to_2));
330 t1 = build_pointer_type (c_build_qualified_type
331 (target,
332 TYPE_QUALS (pointed_to_1) |
333 TYPE_QUALS (pointed_to_2)));
334 return build_type_attribute_variant (t1, attributes);
336 #if 0
337 t1 = build_pointer_type (common_type (TREE_TYPE (t1), TREE_TYPE (t2)));
338 return build_type_attribute_variant (t1, attributes);
339 #endif
341 case ARRAY_TYPE:
343 tree elt = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
344 /* Save space: see if the result is identical to one of the args. */
345 if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
346 return build_type_attribute_variant (t1, attributes);
347 if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
348 return build_type_attribute_variant (t2, attributes);
349 /* Merge the element types, and have a size if either arg has one. */
350 t1 = build_array_type (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
351 return build_type_attribute_variant (t1, attributes);
354 case FUNCTION_TYPE:
355 /* Function types: prefer the one that specified arg types.
356 If both do, merge the arg types. Also merge the return types. */
358 tree valtype = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
359 tree p1 = TYPE_ARG_TYPES (t1);
360 tree p2 = TYPE_ARG_TYPES (t2);
361 int len;
362 tree newargs, n;
363 int i;
365 /* Save space: see if the result is identical to one of the args. */
366 if (valtype == TREE_TYPE (t1) && ! TYPE_ARG_TYPES (t2))
367 return build_type_attribute_variant (t1, attributes);
368 if (valtype == TREE_TYPE (t2) && ! TYPE_ARG_TYPES (t1))
369 return build_type_attribute_variant (t2, attributes);
371 /* Simple way if one arg fails to specify argument types. */
372 if (TYPE_ARG_TYPES (t1) == 0)
374 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
375 return build_type_attribute_variant (t1, attributes);
377 if (TYPE_ARG_TYPES (t2) == 0)
379 t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
380 return build_type_attribute_variant (t1, attributes);
383 /* If both args specify argument types, we must merge the two
384 lists, argument by argument. */
386 pushlevel (0);
387 declare_parm_level (1);
389 len = list_length (p1);
390 newargs = 0;
392 for (i = 0; i < len; i++)
393 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
395 n = newargs;
397 for (; p1;
398 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
400 /* A null type means arg type is not specified.
401 Take whatever the other function type has. */
402 if (TREE_VALUE (p1) == 0)
404 TREE_VALUE (n) = TREE_VALUE (p2);
405 goto parm_done;
407 if (TREE_VALUE (p2) == 0)
409 TREE_VALUE (n) = TREE_VALUE (p1);
410 goto parm_done;
413 /* Given wait (union {union wait *u; int *i} *)
414 and wait (union wait *),
415 prefer union wait * as type of parm. */
416 if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
417 && TREE_VALUE (p1) != TREE_VALUE (p2))
419 tree memb;
420 for (memb = TYPE_FIELDS (TREE_VALUE (p1));
421 memb; memb = TREE_CHAIN (memb))
422 if (comptypes (TREE_TYPE (memb), TREE_VALUE (p2)))
424 TREE_VALUE (n) = TREE_VALUE (p2);
425 if (pedantic)
426 pedwarn ("function types not truly compatible in ISO C");
427 goto parm_done;
430 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
431 && TREE_VALUE (p2) != TREE_VALUE (p1))
433 tree memb;
434 for (memb = TYPE_FIELDS (TREE_VALUE (p2));
435 memb; memb = TREE_CHAIN (memb))
436 if (comptypes (TREE_TYPE (memb), TREE_VALUE (p1)))
438 TREE_VALUE (n) = TREE_VALUE (p1);
439 if (pedantic)
440 pedwarn ("function types not truly compatible in ISO C");
441 goto parm_done;
444 TREE_VALUE (n) = common_type (TREE_VALUE (p1), TREE_VALUE (p2));
445 parm_done: ;
448 poplevel (0, 0, 0);
450 t1 = build_function_type (valtype, newargs);
451 /* ... falls through ... */
454 default:
455 return build_type_attribute_variant (t1, attributes);
460 /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
461 or various other operations. Return 2 if they are compatible
462 but a warning may be needed if you use them together. */
465 comptypes (type1, type2)
466 tree type1, type2;
468 tree t1 = type1;
469 tree t2 = type2;
470 int attrval, val;
472 /* Suppress errors caused by previously reported errors. */
474 if (t1 == t2 || !t1 || !t2
475 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
476 return 1;
478 /* If either type is the internal version of sizetype, return the
479 language version. */
480 if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
481 && TYPE_DOMAIN (t1) != 0)
482 t1 = TYPE_DOMAIN (t1);
484 if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
485 && TYPE_DOMAIN (t2) != 0)
486 t2 = TYPE_DOMAIN (t2);
488 /* Treat an enum type as the integer type of the same width and
489 signedness. */
491 if (TREE_CODE (t1) == ENUMERAL_TYPE)
492 t1 = c_common_type_for_size (TYPE_PRECISION (t1), TREE_UNSIGNED (t1));
493 if (TREE_CODE (t2) == ENUMERAL_TYPE)
494 t2 = c_common_type_for_size (TYPE_PRECISION (t2), TREE_UNSIGNED (t2));
496 if (t1 == t2)
497 return 1;
499 /* Different classes of types can't be compatible. */
501 if (TREE_CODE (t1) != TREE_CODE (t2)) return 0;
503 /* Qualifiers must match. */
505 if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
506 return 0;
508 /* Allow for two different type nodes which have essentially the same
509 definition. Note that we already checked for equality of the type
510 qualifiers (just above). */
512 if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
513 return 1;
515 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
516 if (! (attrval = (*targetm.comp_type_attributes) (t1, t2)))
517 return 0;
519 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
520 val = 0;
522 switch (TREE_CODE (t1))
524 case POINTER_TYPE:
525 val = (TREE_TYPE (t1) == TREE_TYPE (t2)
526 ? 1 : comptypes (TREE_TYPE (t1), TREE_TYPE (t2)));
527 break;
529 case FUNCTION_TYPE:
530 val = function_types_compatible_p (t1, t2);
531 break;
533 case ARRAY_TYPE:
535 tree d1 = TYPE_DOMAIN (t1);
536 tree d2 = TYPE_DOMAIN (t2);
537 bool d1_variable, d2_variable;
538 bool d1_zero, d2_zero;
539 val = 1;
541 /* Target types must match incl. qualifiers. */
542 if (TREE_TYPE (t1) != TREE_TYPE (t2)
543 && 0 == (val = comptypes (TREE_TYPE (t1), TREE_TYPE (t2))))
544 return 0;
546 /* Sizes must match unless one is missing or variable. */
547 if (d1 == 0 || d2 == 0 || d1 == d2)
548 break;
550 d1_zero = ! TYPE_MAX_VALUE (d1);
551 d2_zero = ! TYPE_MAX_VALUE (d2);
553 d1_variable = (! d1_zero
554 && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
555 || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
556 d2_variable = (! d2_zero
557 && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
558 || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
560 if (d1_variable || d2_variable)
561 break;
562 if (d1_zero && d2_zero)
563 break;
564 if (d1_zero || d2_zero
565 || ! tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
566 || ! tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
567 val = 0;
569 break;
572 case RECORD_TYPE:
573 if (flag_objc && objc_comptypes (t1, t2, 0) == 1)
574 val = 1;
575 break;
577 default:
578 break;
580 return attrval == 2 && val == 1 ? 2 : val;
583 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
584 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
585 to 1 or 0 depending if the check of the pointer types is meant to
586 be reflexive or not (typically, assignments are not reflexive,
587 while comparisons are reflexive).
590 static int
591 comp_target_types (ttl, ttr, reflexive)
592 tree ttl, ttr;
593 int reflexive;
595 int val;
597 /* Give objc_comptypes a crack at letting these types through. */
598 if ((val = objc_comptypes (ttl, ttr, reflexive)) >= 0)
599 return val;
601 val = comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (ttl)),
602 TYPE_MAIN_VARIANT (TREE_TYPE (ttr)));
604 if (val == 2 && pedantic)
605 pedwarn ("types are not quite compatible");
606 return val;
609 /* Subroutines of `comptypes'. */
611 /* Return 1 if two function types F1 and F2 are compatible.
612 If either type specifies no argument types,
613 the other must specify a fixed number of self-promoting arg types.
614 Otherwise, if one type specifies only the number of arguments,
615 the other must specify that number of self-promoting arg types.
616 Otherwise, the argument types must match. */
618 static int
619 function_types_compatible_p (f1, f2)
620 tree f1, f2;
622 tree args1, args2;
623 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
624 int val = 1;
625 int val1;
627 if (!(TREE_TYPE (f1) == TREE_TYPE (f2)
628 || (val = comptypes (TREE_TYPE (f1), TREE_TYPE (f2)))))
629 return 0;
631 args1 = TYPE_ARG_TYPES (f1);
632 args2 = TYPE_ARG_TYPES (f2);
634 /* An unspecified parmlist matches any specified parmlist
635 whose argument types don't need default promotions. */
637 if (args1 == 0)
639 if (!self_promoting_args_p (args2))
640 return 0;
641 /* If one of these types comes from a non-prototype fn definition,
642 compare that with the other type's arglist.
643 If they don't match, ask for a warning (but no error). */
644 if (TYPE_ACTUAL_ARG_TYPES (f1)
645 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
646 val = 2;
647 return val;
649 if (args2 == 0)
651 if (!self_promoting_args_p (args1))
652 return 0;
653 if (TYPE_ACTUAL_ARG_TYPES (f2)
654 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
655 val = 2;
656 return val;
659 /* Both types have argument lists: compare them and propagate results. */
660 val1 = type_lists_compatible_p (args1, args2);
661 return val1 != 1 ? val1 : val;
664 /* Check two lists of types for compatibility,
665 returning 0 for incompatible, 1 for compatible,
666 or 2 for compatible with warning. */
668 static int
669 type_lists_compatible_p (args1, args2)
670 tree args1, args2;
672 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
673 int val = 1;
674 int newval = 0;
676 while (1)
678 if (args1 == 0 && args2 == 0)
679 return val;
680 /* If one list is shorter than the other,
681 they fail to match. */
682 if (args1 == 0 || args2 == 0)
683 return 0;
684 /* A null pointer instead of a type
685 means there is supposed to be an argument
686 but nothing is specified about what type it has.
687 So match anything that self-promotes. */
688 if (TREE_VALUE (args1) == 0)
690 if (c_type_promotes_to (TREE_VALUE (args2)) != TREE_VALUE (args2))
691 return 0;
693 else if (TREE_VALUE (args2) == 0)
695 if (c_type_promotes_to (TREE_VALUE (args1)) != TREE_VALUE (args1))
696 return 0;
698 else if (! (newval = comptypes (TYPE_MAIN_VARIANT (TREE_VALUE (args1)),
699 TYPE_MAIN_VARIANT (TREE_VALUE (args2)))))
701 /* Allow wait (union {union wait *u; int *i} *)
702 and wait (union wait *) to be compatible. */
703 if (TREE_CODE (TREE_VALUE (args1)) == UNION_TYPE
704 && (TYPE_NAME (TREE_VALUE (args1)) == 0
705 || TYPE_TRANSPARENT_UNION (TREE_VALUE (args1)))
706 && TREE_CODE (TYPE_SIZE (TREE_VALUE (args1))) == INTEGER_CST
707 && tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args1)),
708 TYPE_SIZE (TREE_VALUE (args2))))
710 tree memb;
711 for (memb = TYPE_FIELDS (TREE_VALUE (args1));
712 memb; memb = TREE_CHAIN (memb))
713 if (comptypes (TREE_TYPE (memb), TREE_VALUE (args2)))
714 break;
715 if (memb == 0)
716 return 0;
718 else if (TREE_CODE (TREE_VALUE (args2)) == UNION_TYPE
719 && (TYPE_NAME (TREE_VALUE (args2)) == 0
720 || TYPE_TRANSPARENT_UNION (TREE_VALUE (args2)))
721 && TREE_CODE (TYPE_SIZE (TREE_VALUE (args2))) == INTEGER_CST
722 && tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args2)),
723 TYPE_SIZE (TREE_VALUE (args1))))
725 tree memb;
726 for (memb = TYPE_FIELDS (TREE_VALUE (args2));
727 memb; memb = TREE_CHAIN (memb))
728 if (comptypes (TREE_TYPE (memb), TREE_VALUE (args1)))
729 break;
730 if (memb == 0)
731 return 0;
733 else
734 return 0;
737 /* comptypes said ok, but record if it said to warn. */
738 if (newval > val)
739 val = newval;
741 args1 = TREE_CHAIN (args1);
742 args2 = TREE_CHAIN (args2);
746 /* Compute the size to increment a pointer by. */
748 tree
749 c_size_in_bytes (type)
750 tree type;
752 enum tree_code code = TREE_CODE (type);
754 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
755 return size_one_node;
757 if (!COMPLETE_OR_VOID_TYPE_P (type))
759 error ("arithmetic on pointer to an incomplete type");
760 return size_one_node;
763 /* Convert in case a char is more than one unit. */
764 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
765 size_int (TYPE_PRECISION (char_type_node)
766 / BITS_PER_UNIT));
769 /* Return either DECL or its known constant value (if it has one). */
771 tree
772 decl_constant_value (decl)
773 tree decl;
775 if (/* Don't change a variable array bound or initial value to a constant
776 in a place where a variable is invalid. */
777 current_function_decl != 0
778 && ! TREE_THIS_VOLATILE (decl)
779 && TREE_READONLY (decl)
780 && DECL_INITIAL (decl) != 0
781 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
782 /* This is invalid if initial value is not constant.
783 If it has either a function call, a memory reference,
784 or a variable, then re-evaluating it could give different results. */
785 && TREE_CONSTANT (DECL_INITIAL (decl))
786 /* Check for cases where this is sub-optimal, even though valid. */
787 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
788 return DECL_INITIAL (decl);
789 return decl;
792 /* Return either DECL or its known constant value (if it has one), but
793 return DECL if pedantic or DECL has mode BLKmode. This is for
794 bug-compatibility with the old behavior of decl_constant_value
795 (before GCC 3.0); every use of this function is a bug and it should
796 be removed before GCC 3.1. It is not appropriate to use pedantic
797 in a way that affects optimization, and BLKmode is probably not the
798 right test for avoiding misoptimizations either. */
800 static tree
801 decl_constant_value_for_broken_optimization (decl)
802 tree decl;
804 if (pedantic || DECL_MODE (decl) == BLKmode)
805 return decl;
806 else
807 return decl_constant_value (decl);
811 /* Perform the default conversion of arrays and functions to pointers.
812 Return the result of converting EXP. For any other expression, just
813 return EXP. */
815 static tree
816 default_function_array_conversion (exp)
817 tree exp;
819 tree orig_exp;
820 tree type = TREE_TYPE (exp);
821 enum tree_code code = TREE_CODE (type);
822 int not_lvalue = 0;
824 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
825 an lvalue.
827 Do not use STRIP_NOPS here! It will remove conversions from pointer
828 to integer and cause infinite recursion. */
829 orig_exp = exp;
830 while (TREE_CODE (exp) == NON_LVALUE_EXPR
831 || (TREE_CODE (exp) == NOP_EXPR
832 && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp)))
834 if (TREE_CODE (exp) == NON_LVALUE_EXPR)
835 not_lvalue = 1;
836 exp = TREE_OPERAND (exp, 0);
839 /* Preserve the original expression code. */
840 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (exp))))
841 C_SET_EXP_ORIGINAL_CODE (exp, C_EXP_ORIGINAL_CODE (orig_exp));
843 if (code == FUNCTION_TYPE)
845 return build_unary_op (ADDR_EXPR, exp, 0);
847 if (code == ARRAY_TYPE)
849 tree adr;
850 tree restype = TREE_TYPE (type);
851 tree ptrtype;
852 int constp = 0;
853 int volatilep = 0;
854 int lvalue_array_p;
856 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'r' || DECL_P (exp))
858 constp = TREE_READONLY (exp);
859 volatilep = TREE_THIS_VOLATILE (exp);
862 if (TYPE_QUALS (type) || constp || volatilep)
863 restype
864 = c_build_qualified_type (restype,
865 TYPE_QUALS (type)
866 | (constp * TYPE_QUAL_CONST)
867 | (volatilep * TYPE_QUAL_VOLATILE));
869 if (TREE_CODE (exp) == INDIRECT_REF)
870 return convert (TYPE_POINTER_TO (restype),
871 TREE_OPERAND (exp, 0));
873 if (TREE_CODE (exp) == COMPOUND_EXPR)
875 tree op1 = default_conversion (TREE_OPERAND (exp, 1));
876 return build (COMPOUND_EXPR, TREE_TYPE (op1),
877 TREE_OPERAND (exp, 0), op1);
880 lvalue_array_p = !not_lvalue && lvalue_p (exp);
881 if (!flag_isoc99 && !lvalue_array_p)
883 /* Before C99, non-lvalue arrays do not decay to pointers.
884 Normally, using such an array would be invalid; but it can
885 be used correctly inside sizeof or as a statement expression.
886 Thus, do not give an error here; an error will result later. */
887 return exp;
890 ptrtype = build_pointer_type (restype);
892 if (TREE_CODE (exp) == VAR_DECL)
894 /* ??? This is not really quite correct
895 in that the type of the operand of ADDR_EXPR
896 is not the target type of the type of the ADDR_EXPR itself.
897 Question is, can this lossage be avoided? */
898 adr = build1 (ADDR_EXPR, ptrtype, exp);
899 if (!c_mark_addressable (exp))
900 return error_mark_node;
901 TREE_CONSTANT (adr) = staticp (exp);
902 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
903 return adr;
905 /* This way is better for a COMPONENT_REF since it can
906 simplify the offset for a component. */
907 adr = build_unary_op (ADDR_EXPR, exp, 1);
908 return convert (ptrtype, adr);
910 return exp;
913 /* Perform default promotions for C data used in expressions.
914 Arrays and functions are converted to pointers;
915 enumeral types or short or char, to int.
916 In addition, manifest constants symbols are replaced by their values. */
918 tree
919 default_conversion (exp)
920 tree exp;
922 tree orig_exp;
923 tree type = TREE_TYPE (exp);
924 enum tree_code code = TREE_CODE (type);
926 if (code == FUNCTION_TYPE || code == ARRAY_TYPE)
927 return default_function_array_conversion (exp);
929 /* Constants can be used directly unless they're not loadable. */
930 if (TREE_CODE (exp) == CONST_DECL)
931 exp = DECL_INITIAL (exp);
933 /* Replace a nonvolatile const static variable with its value unless
934 it is an array, in which case we must be sure that taking the
935 address of the array produces consistent results. */
936 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE)
938 exp = decl_constant_value_for_broken_optimization (exp);
939 type = TREE_TYPE (exp);
942 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
943 an lvalue.
945 Do not use STRIP_NOPS here! It will remove conversions from pointer
946 to integer and cause infinite recursion. */
947 orig_exp = exp;
948 while (TREE_CODE (exp) == NON_LVALUE_EXPR
949 || (TREE_CODE (exp) == NOP_EXPR
950 && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp)))
951 exp = TREE_OPERAND (exp, 0);
953 /* Preserve the original expression code. */
954 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (exp))))
955 C_SET_EXP_ORIGINAL_CODE (exp, C_EXP_ORIGINAL_CODE (orig_exp));
957 /* Normally convert enums to int,
958 but convert wide enums to something wider. */
959 if (code == ENUMERAL_TYPE)
961 type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
962 TYPE_PRECISION (integer_type_node)),
963 ((TYPE_PRECISION (type)
964 >= TYPE_PRECISION (integer_type_node))
965 && TREE_UNSIGNED (type)));
967 return convert (type, exp);
970 if (TREE_CODE (exp) == COMPONENT_REF
971 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
972 /* If it's thinner than an int, promote it like a
973 c_promoting_integer_type_p, otherwise leave it alone. */
974 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
975 TYPE_PRECISION (integer_type_node)))
976 return convert (integer_type_node, exp);
978 if (c_promoting_integer_type_p (type))
980 /* Preserve unsignedness if not really getting any wider. */
981 if (TREE_UNSIGNED (type)
982 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
983 return convert (unsigned_type_node, exp);
985 return convert (integer_type_node, exp);
988 if (code == VOID_TYPE)
990 error ("void value not ignored as it ought to be");
991 return error_mark_node;
993 return exp;
996 /* Look up COMPONENT in a structure or union DECL.
998 If the component name is not found, returns NULL_TREE. Otherwise,
999 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1000 stepping down the chain to the component, which is in the last
1001 TREE_VALUE of the list. Normally the list is of length one, but if
1002 the component is embedded within (nested) anonymous structures or
1003 unions, the list steps down the chain to the component. */
1005 static tree
1006 lookup_field (decl, component)
1007 tree decl, component;
1009 tree type = TREE_TYPE (decl);
1010 tree field;
1012 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1013 to the field elements. Use a binary search on this array to quickly
1014 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1015 will always be set for structures which have many elements. */
1017 if (TYPE_LANG_SPECIFIC (type))
1019 int bot, top, half;
1020 tree *field_array = &TYPE_LANG_SPECIFIC (type)->elts[0];
1022 field = TYPE_FIELDS (type);
1023 bot = 0;
1024 top = TYPE_LANG_SPECIFIC (type)->len;
1025 while (top - bot > 1)
1027 half = (top - bot + 1) >> 1;
1028 field = field_array[bot+half];
1030 if (DECL_NAME (field) == NULL_TREE)
1032 /* Step through all anon unions in linear fashion. */
1033 while (DECL_NAME (field_array[bot]) == NULL_TREE)
1035 field = field_array[bot++];
1036 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1037 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1039 tree anon = lookup_field (field, component);
1041 if (anon)
1042 return tree_cons (NULL_TREE, field, anon);
1046 /* Entire record is only anon unions. */
1047 if (bot > top)
1048 return NULL_TREE;
1050 /* Restart the binary search, with new lower bound. */
1051 continue;
1054 if (DECL_NAME (field) == component)
1055 break;
1056 if (DECL_NAME (field) < component)
1057 bot += half;
1058 else
1059 top = bot + half;
1062 if (DECL_NAME (field_array[bot]) == component)
1063 field = field_array[bot];
1064 else if (DECL_NAME (field) != component)
1065 return NULL_TREE;
1067 else
1069 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1071 if (DECL_NAME (field) == NULL_TREE
1072 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1073 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
1075 tree anon = lookup_field (field, component);
1077 if (anon)
1078 return tree_cons (NULL_TREE, field, anon);
1081 if (DECL_NAME (field) == component)
1082 break;
1085 if (field == NULL_TREE)
1086 return NULL_TREE;
1089 return tree_cons (NULL_TREE, field, NULL_TREE);
1092 /* Make an expression to refer to the COMPONENT field of
1093 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1095 tree
1096 build_component_ref (datum, component)
1097 tree datum, component;
1099 tree type = TREE_TYPE (datum);
1100 enum tree_code code = TREE_CODE (type);
1101 tree field = NULL;
1102 tree ref;
1104 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1105 If pedantic ensure that the arguments are not lvalues; otherwise,
1106 if the component is an array, it would wrongly decay to a pointer in
1107 C89 mode.
1108 We cannot do this with a COND_EXPR, because in a conditional expression
1109 the default promotions are applied to both sides, and this would yield
1110 the wrong type of the result; for example, if the components have
1111 type "char". */
1112 switch (TREE_CODE (datum))
1114 case COMPOUND_EXPR:
1116 tree value = build_component_ref (TREE_OPERAND (datum, 1), component);
1117 return build (COMPOUND_EXPR, TREE_TYPE (value),
1118 TREE_OPERAND (datum, 0), pedantic_non_lvalue (value));
1120 default:
1121 break;
1124 /* See if there is a field or component with name COMPONENT. */
1126 if (code == RECORD_TYPE || code == UNION_TYPE)
1128 if (!COMPLETE_TYPE_P (type))
1130 c_incomplete_type_error (NULL_TREE, type);
1131 return error_mark_node;
1134 field = lookup_field (datum, component);
1136 if (!field)
1138 error ("%s has no member named `%s'",
1139 code == RECORD_TYPE ? "structure" : "union",
1140 IDENTIFIER_POINTER (component));
1141 return error_mark_node;
1144 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1145 This might be better solved in future the way the C++ front
1146 end does it - by giving the anonymous entities each a
1147 separate name and type, and then have build_component_ref
1148 recursively call itself. We can't do that here. */
1149 for (; field; field = TREE_CHAIN (field))
1151 tree subdatum = TREE_VALUE (field);
1153 if (TREE_TYPE (subdatum) == error_mark_node)
1154 return error_mark_node;
1156 ref = build (COMPONENT_REF, TREE_TYPE (subdatum), datum, subdatum);
1157 if (TREE_READONLY (datum) || TREE_READONLY (subdatum))
1158 TREE_READONLY (ref) = 1;
1159 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
1160 TREE_THIS_VOLATILE (ref) = 1;
1162 if (TREE_DEPRECATED (subdatum))
1163 warn_deprecated_use (subdatum);
1165 datum = ref;
1168 return ref;
1170 else if (code != ERROR_MARK)
1171 error ("request for member `%s' in something not a structure or union",
1172 IDENTIFIER_POINTER (component));
1174 return error_mark_node;
1177 /* Given an expression PTR for a pointer, return an expression
1178 for the value pointed to.
1179 ERRORSTRING is the name of the operator to appear in error messages. */
1181 tree
1182 build_indirect_ref (ptr, errorstring)
1183 tree ptr;
1184 const char *errorstring;
1186 tree pointer = default_conversion (ptr);
1187 tree type = TREE_TYPE (pointer);
1189 if (TREE_CODE (type) == POINTER_TYPE)
1191 if (TREE_CODE (pointer) == ADDR_EXPR
1192 && (TREE_TYPE (TREE_OPERAND (pointer, 0))
1193 == TREE_TYPE (type)))
1194 return TREE_OPERAND (pointer, 0);
1195 else
1197 tree t = TREE_TYPE (type);
1198 tree ref = build1 (INDIRECT_REF, TYPE_MAIN_VARIANT (t), pointer);
1200 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
1202 error ("dereferencing pointer to incomplete type");
1203 return error_mark_node;
1205 if (VOID_TYPE_P (t) && skip_evaluation == 0)
1206 warning ("dereferencing `void *' pointer");
1208 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1209 so that we get the proper error message if the result is used
1210 to assign to. Also, &* is supposed to be a no-op.
1211 And ANSI C seems to specify that the type of the result
1212 should be the const type. */
1213 /* A de-reference of a pointer to const is not a const. It is valid
1214 to change it via some other pointer. */
1215 TREE_READONLY (ref) = TYPE_READONLY (t);
1216 TREE_SIDE_EFFECTS (ref)
1217 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
1218 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
1219 return ref;
1222 else if (TREE_CODE (pointer) != ERROR_MARK)
1223 error ("invalid type argument of `%s'", errorstring);
1224 return error_mark_node;
1227 /* This handles expressions of the form "a[i]", which denotes
1228 an array reference.
1230 This is logically equivalent in C to *(a+i), but we may do it differently.
1231 If A is a variable or a member, we generate a primitive ARRAY_REF.
1232 This avoids forcing the array out of registers, and can work on
1233 arrays that are not lvalues (for example, members of structures returned
1234 by functions). */
1236 tree
1237 build_array_ref (array, index)
1238 tree array, index;
1240 if (index == 0)
1242 error ("subscript missing in array reference");
1243 return error_mark_node;
1246 if (TREE_TYPE (array) == error_mark_node
1247 || TREE_TYPE (index) == error_mark_node)
1248 return error_mark_node;
1250 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE
1251 && TREE_CODE (array) != INDIRECT_REF)
1253 tree rval, type;
1255 /* Subscripting with type char is likely to lose
1256 on a machine where chars are signed.
1257 So warn on any machine, but optionally.
1258 Don't warn for unsigned char since that type is safe.
1259 Don't warn for signed char because anyone who uses that
1260 must have done so deliberately. */
1261 if (warn_char_subscripts
1262 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node)
1263 warning ("array subscript has type `char'");
1265 /* Apply default promotions *after* noticing character types. */
1266 index = default_conversion (index);
1268 /* Require integer *after* promotion, for sake of enums. */
1269 if (TREE_CODE (TREE_TYPE (index)) != INTEGER_TYPE)
1271 error ("array subscript is not an integer");
1272 return error_mark_node;
1275 /* An array that is indexed by a non-constant
1276 cannot be stored in a register; we must be able to do
1277 address arithmetic on its address.
1278 Likewise an array of elements of variable size. */
1279 if (TREE_CODE (index) != INTEGER_CST
1280 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
1281 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
1283 if (!c_mark_addressable (array))
1284 return error_mark_node;
1286 /* An array that is indexed by a constant value which is not within
1287 the array bounds cannot be stored in a register either; because we
1288 would get a crash in store_bit_field/extract_bit_field when trying
1289 to access a non-existent part of the register. */
1290 if (TREE_CODE (index) == INTEGER_CST
1291 && TYPE_VALUES (TREE_TYPE (array))
1292 && ! int_fits_type_p (index, TYPE_VALUES (TREE_TYPE (array))))
1294 if (!c_mark_addressable (array))
1295 return error_mark_node;
1298 if (pedantic)
1300 tree foo = array;
1301 while (TREE_CODE (foo) == COMPONENT_REF)
1302 foo = TREE_OPERAND (foo, 0);
1303 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
1304 pedwarn ("ISO C forbids subscripting `register' array");
1305 else if (! flag_isoc99 && ! lvalue_p (foo))
1306 pedwarn ("ISO C90 forbids subscripting non-lvalue array");
1309 type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (array)));
1310 rval = build (ARRAY_REF, type, array, index);
1311 /* Array ref is const/volatile if the array elements are
1312 or if the array is. */
1313 TREE_READONLY (rval)
1314 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
1315 | TREE_READONLY (array));
1316 TREE_SIDE_EFFECTS (rval)
1317 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
1318 | TREE_SIDE_EFFECTS (array));
1319 TREE_THIS_VOLATILE (rval)
1320 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
1321 /* This was added by rms on 16 Nov 91.
1322 It fixes vol struct foo *a; a->elts[1]
1323 in an inline function.
1324 Hope it doesn't break something else. */
1325 | TREE_THIS_VOLATILE (array));
1326 return require_complete_type (fold (rval));
1330 tree ar = default_conversion (array);
1331 tree ind = default_conversion (index);
1333 /* Do the same warning check as above, but only on the part that's
1334 syntactically the index and only if it is also semantically
1335 the index. */
1336 if (warn_char_subscripts
1337 && TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE
1338 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node)
1339 warning ("subscript has type `char'");
1341 /* Put the integer in IND to simplify error checking. */
1342 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
1344 tree temp = ar;
1345 ar = ind;
1346 ind = temp;
1349 if (ar == error_mark_node)
1350 return ar;
1352 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE
1353 || TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) == FUNCTION_TYPE)
1355 error ("subscripted value is neither array nor pointer");
1356 return error_mark_node;
1358 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
1360 error ("array subscript is not an integer");
1361 return error_mark_node;
1364 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, ind, 0),
1365 "array indexing");
1369 /* Build an external reference to identifier ID. FUN indicates
1370 whether this will be used for a function call. */
1371 tree
1372 build_external_ref (id, fun)
1373 tree id;
1374 int fun;
1376 tree ref;
1377 tree decl = lookup_name (id);
1378 tree objc_ivar = lookup_objc_ivar (id);
1380 if (decl && TREE_DEPRECATED (decl))
1381 warn_deprecated_use (decl);
1383 if (!decl || decl == error_mark_node || C_DECL_ANTICIPATED (decl))
1385 if (objc_ivar)
1386 ref = objc_ivar;
1387 else if (fun)
1389 if (!decl || decl == error_mark_node)
1390 /* Ordinary implicit function declaration. */
1391 ref = implicitly_declare (id);
1392 else
1394 /* Implicit declaration of built-in function. Don't
1395 change the built-in declaration, but don't let this
1396 go by silently, either. */
1397 implicit_decl_warning (id);
1399 /* only issue this warning once */
1400 C_DECL_ANTICIPATED (decl) = 0;
1401 ref = decl;
1404 else
1406 /* Reference to undeclared variable, including reference to
1407 builtin outside of function-call context. */
1408 if (current_function_decl == 0)
1409 error ("`%s' undeclared here (not in a function)",
1410 IDENTIFIER_POINTER (id));
1411 else
1413 if (IDENTIFIER_GLOBAL_VALUE (id) != error_mark_node
1414 || IDENTIFIER_ERROR_LOCUS (id) != current_function_decl)
1416 error ("`%s' undeclared (first use in this function)",
1417 IDENTIFIER_POINTER (id));
1419 if (! undeclared_variable_notice)
1421 error ("(Each undeclared identifier is reported only once");
1422 error ("for each function it appears in.)");
1423 undeclared_variable_notice = 1;
1426 IDENTIFIER_GLOBAL_VALUE (id) = error_mark_node;
1427 IDENTIFIER_ERROR_LOCUS (id) = current_function_decl;
1429 return error_mark_node;
1432 else
1434 /* Properly declared variable or function reference. */
1435 if (!objc_ivar)
1436 ref = decl;
1437 else if (decl != objc_ivar && IDENTIFIER_LOCAL_VALUE (id))
1439 warning ("local declaration of `%s' hides instance variable",
1440 IDENTIFIER_POINTER (id));
1441 ref = decl;
1443 else
1444 ref = objc_ivar;
1447 if (TREE_TYPE (ref) == error_mark_node)
1448 return error_mark_node;
1450 if (!skip_evaluation)
1451 assemble_external (ref);
1452 TREE_USED (ref) = 1;
1454 if (TREE_CODE (ref) == CONST_DECL)
1456 ref = DECL_INITIAL (ref);
1457 TREE_CONSTANT (ref) = 1;
1460 return ref;
1463 /* Build a function call to function FUNCTION with parameters PARAMS.
1464 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1465 TREE_VALUE of each node is a parameter-expression.
1466 FUNCTION's data type may be a function type or a pointer-to-function. */
1468 tree
1469 build_function_call (function, params)
1470 tree function, params;
1472 tree fntype, fundecl = 0;
1473 tree coerced_params;
1474 tree name = NULL_TREE, result;
1476 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1477 STRIP_TYPE_NOPS (function);
1479 /* Convert anything with function type to a pointer-to-function. */
1480 if (TREE_CODE (function) == FUNCTION_DECL)
1482 name = DECL_NAME (function);
1484 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1485 (because calling an inline function does not mean the function
1486 needs to be separately compiled). */
1487 fntype = build_type_variant (TREE_TYPE (function),
1488 TREE_READONLY (function),
1489 TREE_THIS_VOLATILE (function));
1490 fundecl = function;
1491 function = build1 (ADDR_EXPR, build_pointer_type (fntype), function);
1493 else
1494 function = default_conversion (function);
1496 fntype = TREE_TYPE (function);
1498 if (TREE_CODE (fntype) == ERROR_MARK)
1499 return error_mark_node;
1501 if (!(TREE_CODE (fntype) == POINTER_TYPE
1502 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
1504 error ("called object is not a function");
1505 return error_mark_node;
1508 if (fundecl && TREE_THIS_VOLATILE (fundecl))
1509 current_function_returns_abnormally = 1;
1511 /* fntype now gets the type of function pointed to. */
1512 fntype = TREE_TYPE (fntype);
1514 /* Convert the parameters to the types declared in the
1515 function prototype, or apply default promotions. */
1517 coerced_params
1518 = convert_arguments (TYPE_ARG_TYPES (fntype), params, name, fundecl);
1520 /* Check that the arguments to the function are valid. */
1522 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
1524 /* Recognize certain built-in functions so we can make tree-codes
1525 other than CALL_EXPR. We do this when it enables fold-const.c
1526 to do something useful. */
1528 if (TREE_CODE (function) == ADDR_EXPR
1529 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL
1530 && DECL_BUILT_IN (TREE_OPERAND (function, 0)))
1532 result = expand_tree_builtin (TREE_OPERAND (function, 0),
1533 params, coerced_params);
1534 if (result)
1535 return result;
1538 result = build (CALL_EXPR, TREE_TYPE (fntype),
1539 function, coerced_params, NULL_TREE);
1540 TREE_SIDE_EFFECTS (result) = 1;
1541 result = fold (result);
1543 if (VOID_TYPE_P (TREE_TYPE (result)))
1544 return result;
1545 return require_complete_type (result);
1548 /* Convert the argument expressions in the list VALUES
1549 to the types in the list TYPELIST. The result is a list of converted
1550 argument expressions.
1552 If TYPELIST is exhausted, or when an element has NULL as its type,
1553 perform the default conversions.
1555 PARMLIST is the chain of parm decls for the function being called.
1556 It may be 0, if that info is not available.
1557 It is used only for generating error messages.
1559 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1561 This is also where warnings about wrong number of args are generated.
1563 Both VALUES and the returned value are chains of TREE_LIST nodes
1564 with the elements of the list in the TREE_VALUE slots of those nodes. */
1566 static tree
1567 convert_arguments (typelist, values, name, fundecl)
1568 tree typelist, values, name, fundecl;
1570 tree typetail, valtail;
1571 tree result = NULL;
1572 int parmnum;
1574 /* Scan the given expressions and types, producing individual
1575 converted arguments and pushing them on RESULT in reverse order. */
1577 for (valtail = values, typetail = typelist, parmnum = 0;
1578 valtail;
1579 valtail = TREE_CHAIN (valtail), parmnum++)
1581 tree type = typetail ? TREE_VALUE (typetail) : 0;
1582 tree val = TREE_VALUE (valtail);
1584 if (type == void_type_node)
1586 if (name)
1587 error ("too many arguments to function `%s'",
1588 IDENTIFIER_POINTER (name));
1589 else
1590 error ("too many arguments to function");
1591 break;
1594 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1595 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1596 to convert automatically to a pointer. */
1597 if (TREE_CODE (val) == NON_LVALUE_EXPR)
1598 val = TREE_OPERAND (val, 0);
1600 val = default_function_array_conversion (val);
1602 val = require_complete_type (val);
1604 if (type != 0)
1606 /* Formal parm type is specified by a function prototype. */
1607 tree parmval;
1609 if (!COMPLETE_TYPE_P (type))
1611 error ("type of formal parameter %d is incomplete", parmnum + 1);
1612 parmval = val;
1614 else
1616 /* Optionally warn about conversions that
1617 differ from the default conversions. */
1618 if (warn_conversion || warn_traditional)
1620 int formal_prec = TYPE_PRECISION (type);
1622 if (INTEGRAL_TYPE_P (type)
1623 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
1624 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1625 if (INTEGRAL_TYPE_P (type)
1626 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
1627 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1628 else if (TREE_CODE (type) == COMPLEX_TYPE
1629 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
1630 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1631 else if (TREE_CODE (type) == REAL_TYPE
1632 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
1633 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1634 else if (TREE_CODE (type) == COMPLEX_TYPE
1635 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
1636 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1637 else if (TREE_CODE (type) == REAL_TYPE
1638 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
1639 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1640 /* ??? At some point, messages should be written about
1641 conversions between complex types, but that's too messy
1642 to do now. */
1643 else if (TREE_CODE (type) == REAL_TYPE
1644 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
1646 /* Warn if any argument is passed as `float',
1647 since without a prototype it would be `double'. */
1648 if (formal_prec == TYPE_PRECISION (float_type_node))
1649 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1651 /* Detect integer changing in width or signedness.
1652 These warnings are only activated with
1653 -Wconversion, not with -Wtraditional. */
1654 else if (warn_conversion && INTEGRAL_TYPE_P (type)
1655 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
1657 tree would_have_been = default_conversion (val);
1658 tree type1 = TREE_TYPE (would_have_been);
1660 if (TREE_CODE (type) == ENUMERAL_TYPE
1661 && (TYPE_MAIN_VARIANT (type)
1662 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
1663 /* No warning if function asks for enum
1664 and the actual arg is that enum type. */
1666 else if (formal_prec != TYPE_PRECISION (type1))
1667 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1668 else if (TREE_UNSIGNED (type) == TREE_UNSIGNED (type1))
1670 /* Don't complain if the formal parameter type
1671 is an enum, because we can't tell now whether
1672 the value was an enum--even the same enum. */
1673 else if (TREE_CODE (type) == ENUMERAL_TYPE)
1675 else if (TREE_CODE (val) == INTEGER_CST
1676 && int_fits_type_p (val, type))
1677 /* Change in signedness doesn't matter
1678 if a constant value is unaffected. */
1680 /* Likewise for a constant in a NOP_EXPR. */
1681 else if (TREE_CODE (val) == NOP_EXPR
1682 && TREE_CODE (TREE_OPERAND (val, 0)) == INTEGER_CST
1683 && int_fits_type_p (TREE_OPERAND (val, 0), type))
1685 #if 0 /* We never get such tree structure here. */
1686 else if (TREE_CODE (TREE_TYPE (val)) == ENUMERAL_TYPE
1687 && int_fits_type_p (TYPE_MIN_VALUE (TREE_TYPE (val)), type)
1688 && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (val)), type))
1689 /* Change in signedness doesn't matter
1690 if an enum value is unaffected. */
1692 #endif
1693 /* If the value is extended from a narrower
1694 unsigned type, it doesn't matter whether we
1695 pass it as signed or unsigned; the value
1696 certainly is the same either way. */
1697 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
1698 && TREE_UNSIGNED (TREE_TYPE (val)))
1700 else if (TREE_UNSIGNED (type))
1701 warn_for_assignment ("%s as unsigned due to prototype", (char *) 0, name, parmnum + 1);
1702 else
1703 warn_for_assignment ("%s as signed due to prototype", (char *) 0, name, parmnum + 1);
1707 parmval = convert_for_assignment (type, val,
1708 (char *) 0, /* arg passing */
1709 fundecl, name, parmnum + 1);
1711 if (PROMOTE_PROTOTYPES
1712 && INTEGRAL_TYPE_P (type)
1713 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
1714 parmval = default_conversion (parmval);
1716 result = tree_cons (NULL_TREE, parmval, result);
1718 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
1719 && (TYPE_PRECISION (TREE_TYPE (val))
1720 < TYPE_PRECISION (double_type_node)))
1721 /* Convert `float' to `double'. */
1722 result = tree_cons (NULL_TREE, convert (double_type_node, val), result);
1723 else
1724 /* Convert `short' and `char' to full-size `int'. */
1725 result = tree_cons (NULL_TREE, default_conversion (val), result);
1727 if (typetail)
1728 typetail = TREE_CHAIN (typetail);
1731 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
1733 if (name)
1734 error ("too few arguments to function `%s'",
1735 IDENTIFIER_POINTER (name));
1736 else
1737 error ("too few arguments to function");
1740 return nreverse (result);
1743 /* This is the entry point used by the parser
1744 for binary operators in the input.
1745 In addition to constructing the expression,
1746 we check for operands that were written with other binary operators
1747 in a way that is likely to confuse the user. */
1749 tree
1750 parser_build_binary_op (code, arg1, arg2)
1751 enum tree_code code;
1752 tree arg1, arg2;
1754 tree result = build_binary_op (code, arg1, arg2, 1);
1756 char class;
1757 char class1 = TREE_CODE_CLASS (TREE_CODE (arg1));
1758 char class2 = TREE_CODE_CLASS (TREE_CODE (arg2));
1759 enum tree_code code1 = ERROR_MARK;
1760 enum tree_code code2 = ERROR_MARK;
1762 if (TREE_CODE (result) == ERROR_MARK)
1763 return error_mark_node;
1765 if (IS_EXPR_CODE_CLASS (class1))
1766 code1 = C_EXP_ORIGINAL_CODE (arg1);
1767 if (IS_EXPR_CODE_CLASS (class2))
1768 code2 = C_EXP_ORIGINAL_CODE (arg2);
1770 /* Check for cases such as x+y<<z which users are likely
1771 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1772 is cleared to prevent these warnings. */
1773 if (warn_parentheses)
1775 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
1777 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
1778 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1779 warning ("suggest parentheses around + or - inside shift");
1782 if (code == TRUTH_ORIF_EXPR)
1784 if (code1 == TRUTH_ANDIF_EXPR
1785 || code2 == TRUTH_ANDIF_EXPR)
1786 warning ("suggest parentheses around && within ||");
1789 if (code == BIT_IOR_EXPR)
1791 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR
1792 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
1793 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR
1794 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1795 warning ("suggest parentheses around arithmetic in operand of |");
1796 /* Check cases like x|y==z */
1797 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')
1798 warning ("suggest parentheses around comparison in operand of |");
1801 if (code == BIT_XOR_EXPR)
1803 if (code1 == BIT_AND_EXPR
1804 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
1805 || code2 == BIT_AND_EXPR
1806 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1807 warning ("suggest parentheses around arithmetic in operand of ^");
1808 /* Check cases like x^y==z */
1809 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')
1810 warning ("suggest parentheses around comparison in operand of ^");
1813 if (code == BIT_AND_EXPR)
1815 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
1816 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1817 warning ("suggest parentheses around + or - in operand of &");
1818 /* Check cases like x&y==z */
1819 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')
1820 warning ("suggest parentheses around comparison in operand of &");
1824 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1825 if (TREE_CODE_CLASS (code) == '<' && extra_warnings
1826 && (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<'))
1827 warning ("comparisons like X<=Y<=Z do not have their mathematical meaning");
1829 unsigned_conversion_warning (result, arg1);
1830 unsigned_conversion_warning (result, arg2);
1831 overflow_warning (result);
1833 class = TREE_CODE_CLASS (TREE_CODE (result));
1835 /* Record the code that was specified in the source,
1836 for the sake of warnings about confusing nesting. */
1837 if (IS_EXPR_CODE_CLASS (class))
1838 C_SET_EXP_ORIGINAL_CODE (result, code);
1839 else
1841 int flag = TREE_CONSTANT (result);
1842 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
1843 so that convert_for_assignment wouldn't strip it.
1844 That way, we got warnings for things like p = (1 - 1).
1845 But it turns out we should not get those warnings. */
1846 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
1847 C_SET_EXP_ORIGINAL_CODE (result, code);
1848 TREE_CONSTANT (result) = flag;
1851 return result;
1854 /* Build a binary-operation expression without default conversions.
1855 CODE is the kind of expression to build.
1856 This function differs from `build' in several ways:
1857 the data type of the result is computed and recorded in it,
1858 warnings are generated if arg data types are invalid,
1859 special handling for addition and subtraction of pointers is known,
1860 and some optimization is done (operations on narrow ints
1861 are done in the narrower type when that gives the same result).
1862 Constant folding is also done before the result is returned.
1864 Note that the operands will never have enumeral types, or function
1865 or array types, because either they will have the default conversions
1866 performed or they have both just been converted to some other type in which
1867 the arithmetic is to be done. */
1869 tree
1870 build_binary_op (code, orig_op0, orig_op1, convert_p)
1871 enum tree_code code;
1872 tree orig_op0, orig_op1;
1873 int convert_p;
1875 tree type0, type1;
1876 enum tree_code code0, code1;
1877 tree op0, op1;
1879 /* Expression code to give to the expression when it is built.
1880 Normally this is CODE, which is what the caller asked for,
1881 but in some special cases we change it. */
1882 enum tree_code resultcode = code;
1884 /* Data type in which the computation is to be performed.
1885 In the simplest cases this is the common type of the arguments. */
1886 tree result_type = NULL;
1888 /* Nonzero means operands have already been type-converted
1889 in whatever way is necessary.
1890 Zero means they need to be converted to RESULT_TYPE. */
1891 int converted = 0;
1893 /* Nonzero means create the expression with this type, rather than
1894 RESULT_TYPE. */
1895 tree build_type = 0;
1897 /* Nonzero means after finally constructing the expression
1898 convert it to this type. */
1899 tree final_type = 0;
1901 /* Nonzero if this is an operation like MIN or MAX which can
1902 safely be computed in short if both args are promoted shorts.
1903 Also implies COMMON.
1904 -1 indicates a bitwise operation; this makes a difference
1905 in the exact conditions for when it is safe to do the operation
1906 in a narrower mode. */
1907 int shorten = 0;
1909 /* Nonzero if this is a comparison operation;
1910 if both args are promoted shorts, compare the original shorts.
1911 Also implies COMMON. */
1912 int short_compare = 0;
1914 /* Nonzero if this is a right-shift operation, which can be computed on the
1915 original short and then promoted if the operand is a promoted short. */
1916 int short_shift = 0;
1918 /* Nonzero means set RESULT_TYPE to the common type of the args. */
1919 int common = 0;
1921 if (convert_p)
1923 op0 = default_conversion (orig_op0);
1924 op1 = default_conversion (orig_op1);
1926 else
1928 op0 = orig_op0;
1929 op1 = orig_op1;
1932 type0 = TREE_TYPE (op0);
1933 type1 = TREE_TYPE (op1);
1935 /* The expression codes of the data types of the arguments tell us
1936 whether the arguments are integers, floating, pointers, etc. */
1937 code0 = TREE_CODE (type0);
1938 code1 = TREE_CODE (type1);
1940 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1941 STRIP_TYPE_NOPS (op0);
1942 STRIP_TYPE_NOPS (op1);
1944 /* If an error was already reported for one of the arguments,
1945 avoid reporting another error. */
1947 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
1948 return error_mark_node;
1950 switch (code)
1952 case PLUS_EXPR:
1953 /* Handle the pointer + int case. */
1954 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
1955 return pointer_int_sum (PLUS_EXPR, op0, op1);
1956 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
1957 return pointer_int_sum (PLUS_EXPR, op1, op0);
1958 else
1959 common = 1;
1960 break;
1962 case MINUS_EXPR:
1963 /* Subtraction of two similar pointers.
1964 We must subtract them as integers, then divide by object size. */
1965 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
1966 && comp_target_types (type0, type1, 1))
1967 return pointer_diff (op0, op1);
1968 /* Handle pointer minus int. Just like pointer plus int. */
1969 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
1970 return pointer_int_sum (MINUS_EXPR, op0, op1);
1971 else
1972 common = 1;
1973 break;
1975 case MULT_EXPR:
1976 common = 1;
1977 break;
1979 case TRUNC_DIV_EXPR:
1980 case CEIL_DIV_EXPR:
1981 case FLOOR_DIV_EXPR:
1982 case ROUND_DIV_EXPR:
1983 case EXACT_DIV_EXPR:
1984 /* Floating point division by zero is a legitimate way to obtain
1985 infinities and NaNs. */
1986 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1))
1987 warning ("division by zero");
1989 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
1990 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
1991 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
1992 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
1994 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
1995 resultcode = RDIV_EXPR;
1996 else
1997 /* Although it would be tempting to shorten always here, that
1998 loses on some targets, since the modulo instruction is
1999 undefined if the quotient can't be represented in the
2000 computation mode. We shorten only if unsigned or if
2001 dividing by something we know != -1. */
2002 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0))
2003 || (TREE_CODE (op1) == INTEGER_CST
2004 && ! integer_all_onesp (op1)));
2005 common = 1;
2007 break;
2009 case BIT_AND_EXPR:
2010 case BIT_ANDTC_EXPR:
2011 case BIT_IOR_EXPR:
2012 case BIT_XOR_EXPR:
2013 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2014 shorten = -1;
2015 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
2016 common = 1;
2017 break;
2019 case TRUNC_MOD_EXPR:
2020 case FLOOR_MOD_EXPR:
2021 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1))
2022 warning ("division by zero");
2024 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2026 /* Although it would be tempting to shorten always here, that loses
2027 on some targets, since the modulo instruction is undefined if the
2028 quotient can't be represented in the computation mode. We shorten
2029 only if unsigned or if dividing by something we know != -1. */
2030 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0))
2031 || (TREE_CODE (op1) == INTEGER_CST
2032 && ! integer_all_onesp (op1)));
2033 common = 1;
2035 break;
2037 case TRUTH_ANDIF_EXPR:
2038 case TRUTH_ORIF_EXPR:
2039 case TRUTH_AND_EXPR:
2040 case TRUTH_OR_EXPR:
2041 case TRUTH_XOR_EXPR:
2042 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
2043 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
2044 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
2045 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
2047 /* Result of these operations is always an int,
2048 but that does not mean the operands should be
2049 converted to ints! */
2050 result_type = integer_type_node;
2051 op0 = c_common_truthvalue_conversion (op0);
2052 op1 = c_common_truthvalue_conversion (op1);
2053 converted = 1;
2055 break;
2057 /* Shift operations: result has same type as first operand;
2058 always convert second operand to int.
2059 Also set SHORT_SHIFT if shifting rightward. */
2061 case RSHIFT_EXPR:
2062 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2064 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
2066 if (tree_int_cst_sgn (op1) < 0)
2067 warning ("right shift count is negative");
2068 else
2070 if (! integer_zerop (op1))
2071 short_shift = 1;
2073 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2074 warning ("right shift count >= width of type");
2078 /* Use the type of the value to be shifted. */
2079 result_type = type0;
2080 /* Convert the shift-count to an integer, regardless of size
2081 of value being shifted. */
2082 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2083 op1 = convert (integer_type_node, op1);
2084 /* Avoid converting op1 to result_type later. */
2085 converted = 1;
2087 break;
2089 case LSHIFT_EXPR:
2090 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2092 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
2094 if (tree_int_cst_sgn (op1) < 0)
2095 warning ("left shift count is negative");
2097 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2098 warning ("left shift count >= width of type");
2101 /* Use the type of the value to be shifted. */
2102 result_type = type0;
2103 /* Convert the shift-count to an integer, regardless of size
2104 of value being shifted. */
2105 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2106 op1 = convert (integer_type_node, op1);
2107 /* Avoid converting op1 to result_type later. */
2108 converted = 1;
2110 break;
2112 case RROTATE_EXPR:
2113 case LROTATE_EXPR:
2114 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2116 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
2118 if (tree_int_cst_sgn (op1) < 0)
2119 warning ("shift count is negative");
2120 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2121 warning ("shift count >= width of type");
2124 /* Use the type of the value to be shifted. */
2125 result_type = type0;
2126 /* Convert the shift-count to an integer, regardless of size
2127 of value being shifted. */
2128 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2129 op1 = convert (integer_type_node, op1);
2130 /* Avoid converting op1 to result_type later. */
2131 converted = 1;
2133 break;
2135 case EQ_EXPR:
2136 case NE_EXPR:
2137 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
2138 warning ("comparing floating point with == or != is unsafe");
2139 /* Result of comparison is always int,
2140 but don't convert the args to int! */
2141 build_type = integer_type_node;
2142 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2143 || code0 == COMPLEX_TYPE
2144 || code0 == VECTOR_TYPE)
2145 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2146 || code1 == COMPLEX_TYPE
2147 || code1 == VECTOR_TYPE))
2148 short_compare = 1;
2149 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2151 tree tt0 = TREE_TYPE (type0);
2152 tree tt1 = TREE_TYPE (type1);
2153 /* Anything compares with void *. void * compares with anything.
2154 Otherwise, the targets must be compatible
2155 and both must be object or both incomplete. */
2156 if (comp_target_types (type0, type1, 1))
2157 result_type = common_type (type0, type1);
2158 else if (VOID_TYPE_P (tt0))
2160 /* op0 != orig_op0 detects the case of something
2161 whose value is 0 but which isn't a valid null ptr const. */
2162 if (pedantic && (!integer_zerop (op0) || op0 != orig_op0)
2163 && TREE_CODE (tt1) == FUNCTION_TYPE)
2164 pedwarn ("ISO C forbids comparison of `void *' with function pointer");
2166 else if (VOID_TYPE_P (tt1))
2168 if (pedantic && (!integer_zerop (op1) || op1 != orig_op1)
2169 && TREE_CODE (tt0) == FUNCTION_TYPE)
2170 pedwarn ("ISO C forbids comparison of `void *' with function pointer");
2172 else
2173 pedwarn ("comparison of distinct pointer types lacks a cast");
2175 if (result_type == NULL_TREE)
2176 result_type = ptr_type_node;
2178 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
2179 && integer_zerop (op1))
2180 result_type = type0;
2181 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
2182 && integer_zerop (op0))
2183 result_type = type1;
2184 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2186 result_type = type0;
2187 pedwarn ("comparison between pointer and integer");
2189 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
2191 result_type = type1;
2192 pedwarn ("comparison between pointer and integer");
2194 break;
2196 case MAX_EXPR:
2197 case MIN_EXPR:
2198 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
2199 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
2200 shorten = 1;
2201 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2203 if (comp_target_types (type0, type1, 1))
2205 result_type = common_type (type0, type1);
2206 if (pedantic
2207 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
2208 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
2210 else
2212 result_type = ptr_type_node;
2213 pedwarn ("comparison of distinct pointer types lacks a cast");
2216 break;
2218 case LE_EXPR:
2219 case GE_EXPR:
2220 case LT_EXPR:
2221 case GT_EXPR:
2222 build_type = integer_type_node;
2223 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
2224 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
2225 short_compare = 1;
2226 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2228 if (comp_target_types (type0, type1, 1))
2230 result_type = common_type (type0, type1);
2231 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
2232 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
2233 pedwarn ("comparison of complete and incomplete pointers");
2234 else if (pedantic
2235 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
2236 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
2238 else
2240 result_type = ptr_type_node;
2241 pedwarn ("comparison of distinct pointer types lacks a cast");
2244 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
2245 && integer_zerop (op1))
2247 result_type = type0;
2248 if (pedantic || extra_warnings)
2249 pedwarn ("ordered comparison of pointer with integer zero");
2251 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
2252 && integer_zerop (op0))
2254 result_type = type1;
2255 if (pedantic)
2256 pedwarn ("ordered comparison of pointer with integer zero");
2258 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2260 result_type = type0;
2261 pedwarn ("comparison between pointer and integer");
2263 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
2265 result_type = type1;
2266 pedwarn ("comparison between pointer and integer");
2268 break;
2270 case UNORDERED_EXPR:
2271 case ORDERED_EXPR:
2272 case UNLT_EXPR:
2273 case UNLE_EXPR:
2274 case UNGT_EXPR:
2275 case UNGE_EXPR:
2276 case UNEQ_EXPR:
2277 build_type = integer_type_node;
2278 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
2280 error ("unordered comparison on non-floating point argument");
2281 return error_mark_node;
2283 common = 1;
2284 break;
2286 default:
2287 break;
2290 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
2291 || code0 == VECTOR_TYPE)
2293 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
2294 || code1 == VECTOR_TYPE))
2296 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
2298 if (shorten || common || short_compare)
2299 result_type = common_type (type0, type1);
2301 /* For certain operations (which identify themselves by shorten != 0)
2302 if both args were extended from the same smaller type,
2303 do the arithmetic in that type and then extend.
2305 shorten !=0 and !=1 indicates a bitwise operation.
2306 For them, this optimization is safe only if
2307 both args are zero-extended or both are sign-extended.
2308 Otherwise, we might change the result.
2309 Eg, (short)-1 | (unsigned short)-1 is (int)-1
2310 but calculated in (unsigned short) it would be (unsigned short)-1. */
2312 if (shorten && none_complex)
2314 int unsigned0, unsigned1;
2315 tree arg0 = get_narrower (op0, &unsigned0);
2316 tree arg1 = get_narrower (op1, &unsigned1);
2317 /* UNS is 1 if the operation to be done is an unsigned one. */
2318 int uns = TREE_UNSIGNED (result_type);
2319 tree type;
2321 final_type = result_type;
2323 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
2324 but it *requires* conversion to FINAL_TYPE. */
2326 if ((TYPE_PRECISION (TREE_TYPE (op0))
2327 == TYPE_PRECISION (TREE_TYPE (arg0)))
2328 && TREE_TYPE (op0) != final_type)
2329 unsigned0 = TREE_UNSIGNED (TREE_TYPE (op0));
2330 if ((TYPE_PRECISION (TREE_TYPE (op1))
2331 == TYPE_PRECISION (TREE_TYPE (arg1)))
2332 && TREE_TYPE (op1) != final_type)
2333 unsigned1 = TREE_UNSIGNED (TREE_TYPE (op1));
2335 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
2337 /* For bitwise operations, signedness of nominal type
2338 does not matter. Consider only how operands were extended. */
2339 if (shorten == -1)
2340 uns = unsigned0;
2342 /* Note that in all three cases below we refrain from optimizing
2343 an unsigned operation on sign-extended args.
2344 That would not be valid. */
2346 /* Both args variable: if both extended in same way
2347 from same width, do it in that width.
2348 Do it unsigned if args were zero-extended. */
2349 if ((TYPE_PRECISION (TREE_TYPE (arg0))
2350 < TYPE_PRECISION (result_type))
2351 && (TYPE_PRECISION (TREE_TYPE (arg1))
2352 == TYPE_PRECISION (TREE_TYPE (arg0)))
2353 && unsigned0 == unsigned1
2354 && (unsigned0 || !uns))
2355 result_type
2356 = c_common_signed_or_unsigned_type
2357 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
2358 else if (TREE_CODE (arg0) == INTEGER_CST
2359 && (unsigned1 || !uns)
2360 && (TYPE_PRECISION (TREE_TYPE (arg1))
2361 < TYPE_PRECISION (result_type))
2362 && (type
2363 = c_common_signed_or_unsigned_type (unsigned1,
2364 TREE_TYPE (arg1)),
2365 int_fits_type_p (arg0, type)))
2366 result_type = type;
2367 else if (TREE_CODE (arg1) == INTEGER_CST
2368 && (unsigned0 || !uns)
2369 && (TYPE_PRECISION (TREE_TYPE (arg0))
2370 < TYPE_PRECISION (result_type))
2371 && (type
2372 = c_common_signed_or_unsigned_type (unsigned0,
2373 TREE_TYPE (arg0)),
2374 int_fits_type_p (arg1, type)))
2375 result_type = type;
2378 /* Shifts can be shortened if shifting right. */
2380 if (short_shift)
2382 int unsigned_arg;
2383 tree arg0 = get_narrower (op0, &unsigned_arg);
2385 final_type = result_type;
2387 if (arg0 == op0 && final_type == TREE_TYPE (op0))
2388 unsigned_arg = TREE_UNSIGNED (TREE_TYPE (op0));
2390 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
2391 /* We can shorten only if the shift count is less than the
2392 number of bits in the smaller type size. */
2393 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
2394 /* We cannot drop an unsigned shift after sign-extension. */
2395 && (!TREE_UNSIGNED (final_type) || unsigned_arg))
2397 /* Do an unsigned shift if the operand was zero-extended. */
2398 result_type
2399 = c_common_signed_or_unsigned_type (unsigned_arg,
2400 TREE_TYPE (arg0));
2401 /* Convert value-to-be-shifted to that type. */
2402 if (TREE_TYPE (op0) != result_type)
2403 op0 = convert (result_type, op0);
2404 converted = 1;
2408 /* Comparison operations are shortened too but differently.
2409 They identify themselves by setting short_compare = 1. */
2411 if (short_compare)
2413 /* Don't write &op0, etc., because that would prevent op0
2414 from being kept in a register.
2415 Instead, make copies of the our local variables and
2416 pass the copies by reference, then copy them back afterward. */
2417 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
2418 enum tree_code xresultcode = resultcode;
2419 tree val
2420 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
2422 if (val != 0)
2423 return val;
2425 op0 = xop0, op1 = xop1;
2426 converted = 1;
2427 resultcode = xresultcode;
2429 if ((warn_sign_compare < 0 ? extra_warnings : warn_sign_compare != 0)
2430 && skip_evaluation == 0)
2432 int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0));
2433 int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1));
2434 int unsignedp0, unsignedp1;
2435 tree primop0 = get_narrower (op0, &unsignedp0);
2436 tree primop1 = get_narrower (op1, &unsignedp1);
2438 xop0 = orig_op0;
2439 xop1 = orig_op1;
2440 STRIP_TYPE_NOPS (xop0);
2441 STRIP_TYPE_NOPS (xop1);
2443 /* Give warnings for comparisons between signed and unsigned
2444 quantities that may fail.
2446 Do the checking based on the original operand trees, so that
2447 casts will be considered, but default promotions won't be.
2449 Do not warn if the comparison is being done in a signed type,
2450 since the signed type will only be chosen if it can represent
2451 all the values of the unsigned type. */
2452 if (! TREE_UNSIGNED (result_type))
2453 /* OK */;
2454 /* Do not warn if both operands are the same signedness. */
2455 else if (op0_signed == op1_signed)
2456 /* OK */;
2457 else
2459 tree sop, uop;
2461 if (op0_signed)
2462 sop = xop0, uop = xop1;
2463 else
2464 sop = xop1, uop = xop0;
2466 /* Do not warn if the signed quantity is an
2467 unsuffixed integer literal (or some static
2468 constant expression involving such literals or a
2469 conditional expression involving such literals)
2470 and it is non-negative. */
2471 if (c_tree_expr_nonnegative_p (sop))
2472 /* OK */;
2473 /* Do not warn if the comparison is an equality operation,
2474 the unsigned quantity is an integral constant, and it
2475 would fit in the result if the result were signed. */
2476 else if (TREE_CODE (uop) == INTEGER_CST
2477 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
2478 && int_fits_type_p
2479 (uop, c_common_signed_type (result_type)))
2480 /* OK */;
2481 /* Do not warn if the unsigned quantity is an enumeration
2482 constant and its maximum value would fit in the result
2483 if the result were signed. */
2484 else if (TREE_CODE (uop) == INTEGER_CST
2485 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
2486 && int_fits_type_p
2487 (TYPE_MAX_VALUE (TREE_TYPE(uop)),
2488 c_common_signed_type (result_type)))
2489 /* OK */;
2490 else
2491 warning ("comparison between signed and unsigned");
2494 /* Warn if two unsigned values are being compared in a size
2495 larger than their original size, and one (and only one) is the
2496 result of a `~' operator. This comparison will always fail.
2498 Also warn if one operand is a constant, and the constant
2499 does not have all bits set that are set in the ~ operand
2500 when it is extended. */
2502 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
2503 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
2505 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
2506 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
2507 &unsignedp0);
2508 else
2509 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
2510 &unsignedp1);
2512 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
2514 tree primop;
2515 HOST_WIDE_INT constant, mask;
2516 int unsignedp, bits;
2518 if (host_integerp (primop0, 0))
2520 primop = primop1;
2521 unsignedp = unsignedp1;
2522 constant = tree_low_cst (primop0, 0);
2524 else
2526 primop = primop0;
2527 unsignedp = unsignedp0;
2528 constant = tree_low_cst (primop1, 0);
2531 bits = TYPE_PRECISION (TREE_TYPE (primop));
2532 if (bits < TYPE_PRECISION (result_type)
2533 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
2535 mask = (~ (HOST_WIDE_INT) 0) << bits;
2536 if ((mask & constant) != mask)
2537 warning ("comparison of promoted ~unsigned with constant");
2540 else if (unsignedp0 && unsignedp1
2541 && (TYPE_PRECISION (TREE_TYPE (primop0))
2542 < TYPE_PRECISION (result_type))
2543 && (TYPE_PRECISION (TREE_TYPE (primop1))
2544 < TYPE_PRECISION (result_type)))
2545 warning ("comparison of promoted ~unsigned with unsigned");
2551 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
2552 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
2553 Then the expression will be built.
2554 It will be given type FINAL_TYPE if that is nonzero;
2555 otherwise, it will be given type RESULT_TYPE. */
2557 if (!result_type)
2559 binary_op_error (code);
2560 return error_mark_node;
2563 if (! converted)
2565 if (TREE_TYPE (op0) != result_type)
2566 op0 = convert (result_type, op0);
2567 if (TREE_TYPE (op1) != result_type)
2568 op1 = convert (result_type, op1);
2571 if (build_type == NULL_TREE)
2572 build_type = result_type;
2575 tree result = build (resultcode, build_type, op0, op1);
2576 tree folded;
2578 folded = fold (result);
2579 if (folded == result)
2580 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
2581 if (final_type != 0)
2582 return convert (final_type, folded);
2583 return folded;
2588 /* Return true if `t' is known to be non-negative. */
2591 c_tree_expr_nonnegative_p (t)
2592 tree t;
2594 if (TREE_CODE (t) == STMT_EXPR)
2596 t=COMPOUND_BODY (STMT_EXPR_STMT (t));
2598 /* Find the last statement in the chain, ignoring the final
2599 * scope statement */
2600 while (TREE_CHAIN (t) != NULL_TREE
2601 && TREE_CODE (TREE_CHAIN (t)) != SCOPE_STMT)
2602 t=TREE_CHAIN (t);
2603 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
2605 return tree_expr_nonnegative_p (t);
2608 /* Return a tree for the difference of pointers OP0 and OP1.
2609 The resulting tree has type int. */
2611 static tree
2612 pointer_diff (op0, op1)
2613 tree op0, op1;
2615 tree result, folded;
2616 tree restype = ptrdiff_type_node;
2618 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2619 tree con0, con1, lit0, lit1;
2620 tree orig_op1 = op1;
2622 if (pedantic || warn_pointer_arith)
2624 if (TREE_CODE (target_type) == VOID_TYPE)
2625 pedwarn ("pointer of type `void *' used in subtraction");
2626 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2627 pedwarn ("pointer to a function used in subtraction");
2630 /* If the conversion to ptrdiff_type does anything like widening or
2631 converting a partial to an integral mode, we get a convert_expression
2632 that is in the way to do any simplifications.
2633 (fold-const.c doesn't know that the extra bits won't be needed.
2634 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2635 different mode in place.)
2636 So first try to find a common term here 'by hand'; we want to cover
2637 at least the cases that occur in legal static initializers. */
2638 con0 = TREE_CODE (op0) == NOP_EXPR ? TREE_OPERAND (op0, 0) : op0;
2639 con1 = TREE_CODE (op1) == NOP_EXPR ? TREE_OPERAND (op1, 0) : op1;
2641 if (TREE_CODE (con0) == PLUS_EXPR)
2643 lit0 = TREE_OPERAND (con0, 1);
2644 con0 = TREE_OPERAND (con0, 0);
2646 else
2647 lit0 = integer_zero_node;
2649 if (TREE_CODE (con1) == PLUS_EXPR)
2651 lit1 = TREE_OPERAND (con1, 1);
2652 con1 = TREE_OPERAND (con1, 0);
2654 else
2655 lit1 = integer_zero_node;
2657 if (operand_equal_p (con0, con1, 0))
2659 op0 = lit0;
2660 op1 = lit1;
2664 /* First do the subtraction as integers;
2665 then drop through to build the divide operator.
2666 Do not do default conversions on the minus operator
2667 in case restype is a short type. */
2669 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2670 convert (restype, op1), 0);
2671 /* This generates an error if op1 is pointer to incomplete type. */
2672 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2673 error ("arithmetic on pointer to an incomplete type");
2675 /* This generates an error if op0 is pointer to incomplete type. */
2676 op1 = c_size_in_bytes (target_type);
2678 /* Divide by the size, in easiest possible way. */
2680 result = build (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2682 folded = fold (result);
2683 if (folded == result)
2684 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
2685 return folded;
2688 /* Construct and perhaps optimize a tree representation
2689 for a unary operation. CODE, a tree_code, specifies the operation
2690 and XARG is the operand.
2691 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2692 the default promotions (such as from short to int).
2693 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2694 allows non-lvalues; this is only used to handle conversion of non-lvalue
2695 arrays to pointers in C99. */
2697 tree
2698 build_unary_op (code, xarg, flag)
2699 enum tree_code code;
2700 tree xarg;
2701 int flag;
2703 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2704 tree arg = xarg;
2705 tree argtype = 0;
2706 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2707 tree val;
2708 int noconvert = flag;
2710 if (typecode == ERROR_MARK)
2711 return error_mark_node;
2712 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2713 typecode = INTEGER_TYPE;
2715 switch (code)
2717 case CONVERT_EXPR:
2718 /* This is used for unary plus, because a CONVERT_EXPR
2719 is enough to prevent anybody from looking inside for
2720 associativity, but won't generate any code. */
2721 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2722 || typecode == COMPLEX_TYPE))
2724 error ("wrong type argument to unary plus");
2725 return error_mark_node;
2727 else if (!noconvert)
2728 arg = default_conversion (arg);
2729 arg = non_lvalue (arg);
2730 break;
2732 case NEGATE_EXPR:
2733 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2734 || typecode == COMPLEX_TYPE
2735 || typecode == VECTOR_TYPE))
2737 error ("wrong type argument to unary minus");
2738 return error_mark_node;
2740 else if (!noconvert)
2741 arg = default_conversion (arg);
2742 break;
2744 case BIT_NOT_EXPR:
2745 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE)
2747 if (!noconvert)
2748 arg = default_conversion (arg);
2750 else if (typecode == COMPLEX_TYPE)
2752 code = CONJ_EXPR;
2753 if (pedantic)
2754 pedwarn ("ISO C does not support `~' for complex conjugation");
2755 if (!noconvert)
2756 arg = default_conversion (arg);
2758 else
2760 error ("wrong type argument to bit-complement");
2761 return error_mark_node;
2763 break;
2765 case ABS_EXPR:
2766 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2767 || typecode == COMPLEX_TYPE))
2769 error ("wrong type argument to abs");
2770 return error_mark_node;
2772 else if (!noconvert)
2773 arg = default_conversion (arg);
2774 break;
2776 case CONJ_EXPR:
2777 /* Conjugating a real value is a no-op, but allow it anyway. */
2778 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2779 || typecode == COMPLEX_TYPE))
2781 error ("wrong type argument to conjugation");
2782 return error_mark_node;
2784 else if (!noconvert)
2785 arg = default_conversion (arg);
2786 break;
2788 case TRUTH_NOT_EXPR:
2789 if (typecode != INTEGER_TYPE
2790 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2791 && typecode != COMPLEX_TYPE
2792 /* These will convert to a pointer. */
2793 && typecode != ARRAY_TYPE && typecode != FUNCTION_TYPE)
2795 error ("wrong type argument to unary exclamation mark");
2796 return error_mark_node;
2798 arg = c_common_truthvalue_conversion (arg);
2799 return invert_truthvalue (arg);
2801 case NOP_EXPR:
2802 break;
2804 case REALPART_EXPR:
2805 if (TREE_CODE (arg) == COMPLEX_CST)
2806 return TREE_REALPART (arg);
2807 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2808 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
2809 else
2810 return arg;
2812 case IMAGPART_EXPR:
2813 if (TREE_CODE (arg) == COMPLEX_CST)
2814 return TREE_IMAGPART (arg);
2815 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2816 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
2817 else
2818 return convert (TREE_TYPE (arg), integer_zero_node);
2820 case PREINCREMENT_EXPR:
2821 case POSTINCREMENT_EXPR:
2822 case PREDECREMENT_EXPR:
2823 case POSTDECREMENT_EXPR:
2824 /* Handle complex lvalues (when permitted)
2825 by reduction to simpler cases. */
2827 val = unary_complex_lvalue (code, arg, 0);
2828 if (val != 0)
2829 return val;
2831 /* Increment or decrement the real part of the value,
2832 and don't change the imaginary part. */
2833 if (typecode == COMPLEX_TYPE)
2835 tree real, imag;
2837 if (pedantic)
2838 pedwarn ("ISO C does not support `++' and `--' on complex types");
2840 arg = stabilize_reference (arg);
2841 real = build_unary_op (REALPART_EXPR, arg, 1);
2842 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2843 return build (COMPLEX_EXPR, TREE_TYPE (arg),
2844 build_unary_op (code, real, 1), imag);
2847 /* Report invalid types. */
2849 if (typecode != POINTER_TYPE
2850 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2852 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2853 error ("wrong type argument to increment");
2854 else
2855 error ("wrong type argument to decrement");
2857 return error_mark_node;
2861 tree inc;
2862 tree result_type = TREE_TYPE (arg);
2864 arg = get_unwidened (arg, 0);
2865 argtype = TREE_TYPE (arg);
2867 /* Compute the increment. */
2869 if (typecode == POINTER_TYPE)
2871 /* If pointer target is an undefined struct,
2872 we just cannot know how to do the arithmetic. */
2873 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2875 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2876 error ("increment of pointer to unknown structure");
2877 else
2878 error ("decrement of pointer to unknown structure");
2880 else if ((pedantic || warn_pointer_arith)
2881 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2882 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2884 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2885 pedwarn ("wrong type argument to increment");
2886 else
2887 pedwarn ("wrong type argument to decrement");
2890 inc = c_size_in_bytes (TREE_TYPE (result_type));
2892 else
2893 inc = integer_one_node;
2895 inc = convert (argtype, inc);
2897 /* Handle incrementing a cast-expression. */
2899 while (1)
2900 switch (TREE_CODE (arg))
2902 case NOP_EXPR:
2903 case CONVERT_EXPR:
2904 case FLOAT_EXPR:
2905 case FIX_TRUNC_EXPR:
2906 case FIX_FLOOR_EXPR:
2907 case FIX_ROUND_EXPR:
2908 case FIX_CEIL_EXPR:
2909 pedantic_lvalue_warning (CONVERT_EXPR);
2910 /* If the real type has the same machine representation
2911 as the type it is cast to, we can make better output
2912 by adding directly to the inside of the cast. */
2913 if ((TREE_CODE (TREE_TYPE (arg))
2914 == TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0))))
2915 && (TYPE_MODE (TREE_TYPE (arg))
2916 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (arg, 0)))))
2917 arg = TREE_OPERAND (arg, 0);
2918 else
2920 tree incremented, modify, value;
2921 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2922 value = boolean_increment (code, arg);
2923 else
2925 arg = stabilize_reference (arg);
2926 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
2927 value = arg;
2928 else
2929 value = save_expr (arg);
2930 incremented = build (((code == PREINCREMENT_EXPR
2931 || code == POSTINCREMENT_EXPR)
2932 ? PLUS_EXPR : MINUS_EXPR),
2933 argtype, value, inc);
2934 TREE_SIDE_EFFECTS (incremented) = 1;
2935 modify = build_modify_expr (arg, NOP_EXPR, incremented);
2936 value = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value);
2938 TREE_USED (value) = 1;
2939 return value;
2941 break;
2943 default:
2944 goto give_up;
2946 give_up:
2948 /* Complain about anything else that is not a true lvalue. */
2949 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
2950 || code == POSTINCREMENT_EXPR)
2951 ? "invalid lvalue in increment"
2952 : "invalid lvalue in decrement")))
2953 return error_mark_node;
2955 /* Report a read-only lvalue. */
2956 if (TREE_READONLY (arg))
2957 readonly_warning (arg,
2958 ((code == PREINCREMENT_EXPR
2959 || code == POSTINCREMENT_EXPR)
2960 ? "increment" : "decrement"));
2962 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2963 val = boolean_increment (code, arg);
2964 else
2965 val = build (code, TREE_TYPE (arg), arg, inc);
2966 TREE_SIDE_EFFECTS (val) = 1;
2967 val = convert (result_type, val);
2968 if (TREE_CODE (val) != code)
2969 TREE_NO_UNUSED_WARNING (val) = 1;
2970 return val;
2973 case ADDR_EXPR:
2974 /* Note that this operation never does default_conversion. */
2976 /* Let &* cancel out to simplify resulting code. */
2977 if (TREE_CODE (arg) == INDIRECT_REF)
2979 /* Don't let this be an lvalue. */
2980 if (lvalue_p (TREE_OPERAND (arg, 0)))
2981 return non_lvalue (TREE_OPERAND (arg, 0));
2982 return TREE_OPERAND (arg, 0);
2985 /* For &x[y], return x+y */
2986 if (TREE_CODE (arg) == ARRAY_REF)
2988 if (!c_mark_addressable (TREE_OPERAND (arg, 0)))
2989 return error_mark_node;
2990 return build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
2991 TREE_OPERAND (arg, 1), 1);
2994 /* Handle complex lvalues (when permitted)
2995 by reduction to simpler cases. */
2996 val = unary_complex_lvalue (code, arg, flag);
2997 if (val != 0)
2998 return val;
3000 #if 0 /* Turned off because inconsistent;
3001 float f; *&(int)f = 3.4 stores in int format
3002 whereas (int)f = 3.4 stores in float format. */
3003 /* Address of a cast is just a cast of the address
3004 of the operand of the cast. */
3005 switch (TREE_CODE (arg))
3007 case NOP_EXPR:
3008 case CONVERT_EXPR:
3009 case FLOAT_EXPR:
3010 case FIX_TRUNC_EXPR:
3011 case FIX_FLOOR_EXPR:
3012 case FIX_ROUND_EXPR:
3013 case FIX_CEIL_EXPR:
3014 if (pedantic)
3015 pedwarn ("ISO C forbids the address of a cast expression");
3016 return convert (build_pointer_type (TREE_TYPE (arg)),
3017 build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0),
3018 0));
3020 #endif
3022 /* Anything not already handled and not a true memory reference
3023 or a non-lvalue array is an error. */
3024 else if (typecode != FUNCTION_TYPE && !flag
3025 && !lvalue_or_else (arg, "invalid lvalue in unary `&'"))
3026 return error_mark_node;
3028 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3029 argtype = TREE_TYPE (arg);
3031 /* If the lvalue is const or volatile, merge that into the type
3032 to which the address will point. Note that you can't get a
3033 restricted pointer by taking the address of something, so we
3034 only have to deal with `const' and `volatile' here. */
3035 if ((DECL_P (arg) || TREE_CODE_CLASS (TREE_CODE (arg)) == 'r')
3036 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3037 argtype = c_build_type_variant (argtype,
3038 TREE_READONLY (arg),
3039 TREE_THIS_VOLATILE (arg));
3041 argtype = build_pointer_type (argtype);
3043 if (!c_mark_addressable (arg))
3044 return error_mark_node;
3047 tree addr;
3049 if (TREE_CODE (arg) == COMPONENT_REF)
3051 tree field = TREE_OPERAND (arg, 1);
3053 addr = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), flag);
3055 if (DECL_C_BIT_FIELD (field))
3057 error ("attempt to take address of bit-field structure member `%s'",
3058 IDENTIFIER_POINTER (DECL_NAME (field)));
3059 return error_mark_node;
3062 addr = fold (build (PLUS_EXPR, argtype,
3063 convert (argtype, addr),
3064 convert (argtype, byte_position (field))));
3066 else
3067 addr = build1 (code, argtype, arg);
3069 /* Address of a static or external variable or
3070 file-scope function counts as a constant. */
3071 if (staticp (arg)
3072 && ! (TREE_CODE (arg) == FUNCTION_DECL
3073 && DECL_CONTEXT (arg) != 0))
3074 TREE_CONSTANT (addr) = 1;
3075 return addr;
3078 default:
3079 break;
3082 if (argtype == 0)
3083 argtype = TREE_TYPE (arg);
3084 return fold (build1 (code, argtype, arg));
3087 #if 0
3088 /* If CONVERSIONS is a conversion expression or a nested sequence of such,
3089 convert ARG with the same conversions in the same order
3090 and return the result. */
3092 static tree
3093 convert_sequence (conversions, arg)
3094 tree conversions;
3095 tree arg;
3097 switch (TREE_CODE (conversions))
3099 case NOP_EXPR:
3100 case CONVERT_EXPR:
3101 case FLOAT_EXPR:
3102 case FIX_TRUNC_EXPR:
3103 case FIX_FLOOR_EXPR:
3104 case FIX_ROUND_EXPR:
3105 case FIX_CEIL_EXPR:
3106 return convert (TREE_TYPE (conversions),
3107 convert_sequence (TREE_OPERAND (conversions, 0),
3108 arg));
3110 default:
3111 return arg;
3114 #endif /* 0 */
3116 /* Return nonzero if REF is an lvalue valid for this language.
3117 Lvalues can be assigned, unless their type has TYPE_READONLY.
3118 Lvalues can have their address taken, unless they have DECL_REGISTER. */
3121 lvalue_p (ref)
3122 tree ref;
3124 enum tree_code code = TREE_CODE (ref);
3126 switch (code)
3128 case REALPART_EXPR:
3129 case IMAGPART_EXPR:
3130 case COMPONENT_REF:
3131 return lvalue_p (TREE_OPERAND (ref, 0));
3133 case COMPOUND_LITERAL_EXPR:
3134 case STRING_CST:
3135 return 1;
3137 case INDIRECT_REF:
3138 case ARRAY_REF:
3139 case VAR_DECL:
3140 case PARM_DECL:
3141 case RESULT_DECL:
3142 case ERROR_MARK:
3143 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3144 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3146 case BIND_EXPR:
3147 case RTL_EXPR:
3148 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3150 default:
3151 return 0;
3155 /* Return nonzero if REF is an lvalue valid for this language;
3156 otherwise, print an error message and return zero. */
3159 lvalue_or_else (ref, msgid)
3160 tree ref;
3161 const char *msgid;
3163 int win = lvalue_p (ref);
3165 if (! win)
3166 error ("%s", msgid);
3168 return win;
3171 /* Apply unary lvalue-demanding operator CODE to the expression ARG
3172 for certain kinds of expressions which are not really lvalues
3173 but which we can accept as lvalues. If FLAG is nonzero, then
3174 non-lvalues are OK since we may be converting a non-lvalue array to
3175 a pointer in C99.
3177 If ARG is not a kind of expression we can handle, return zero. */
3179 static tree
3180 unary_complex_lvalue (code, arg, flag)
3181 enum tree_code code;
3182 tree arg;
3183 int flag;
3185 /* Handle (a, b) used as an "lvalue". */
3186 if (TREE_CODE (arg) == COMPOUND_EXPR)
3188 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
3190 /* If this returns a function type, it isn't really being used as
3191 an lvalue, so don't issue a warning about it. */
3192 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag)
3193 pedantic_lvalue_warning (COMPOUND_EXPR);
3195 return build (COMPOUND_EXPR, TREE_TYPE (real_result),
3196 TREE_OPERAND (arg, 0), real_result);
3199 /* Handle (a ? b : c) used as an "lvalue". */
3200 if (TREE_CODE (arg) == COND_EXPR)
3202 if (!flag)
3203 pedantic_lvalue_warning (COND_EXPR);
3204 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag)
3205 pedantic_lvalue_warning (COMPOUND_EXPR);
3207 return (build_conditional_expr
3208 (TREE_OPERAND (arg, 0),
3209 build_unary_op (code, TREE_OPERAND (arg, 1), flag),
3210 build_unary_op (code, TREE_OPERAND (arg, 2), flag)));
3213 return 0;
3216 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
3217 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
3219 static void
3220 pedantic_lvalue_warning (code)
3221 enum tree_code code;
3223 if (pedantic)
3224 switch (code)
3226 case COND_EXPR:
3227 pedwarn ("ISO C forbids use of conditional expressions as lvalues");
3228 break;
3229 case COMPOUND_EXPR:
3230 pedwarn ("ISO C forbids use of compound expressions as lvalues");
3231 break;
3232 default:
3233 pedwarn ("ISO C forbids use of cast expressions as lvalues");
3234 break;
3238 /* Warn about storing in something that is `const'. */
3240 void
3241 readonly_warning (arg, msgid)
3242 tree arg;
3243 const char *msgid;
3245 if (TREE_CODE (arg) == COMPONENT_REF)
3247 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3248 readonly_warning (TREE_OPERAND (arg, 0), msgid);
3249 else
3250 pedwarn ("%s of read-only member `%s'", _(msgid),
3251 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (arg, 1))));
3253 else if (TREE_CODE (arg) == VAR_DECL)
3254 pedwarn ("%s of read-only variable `%s'", _(msgid),
3255 IDENTIFIER_POINTER (DECL_NAME (arg)));
3256 else
3257 pedwarn ("%s of read-only location", _(msgid));
3260 /* Mark EXP saying that we need to be able to take the
3261 address of it; it should not be allocated in a register.
3262 Returns true if successful. */
3264 bool
3265 c_mark_addressable (exp)
3266 tree exp;
3268 tree x = exp;
3270 while (1)
3271 switch (TREE_CODE (x))
3273 case COMPONENT_REF:
3274 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3276 error ("cannot take address of bit-field `%s'",
3277 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (x, 1))));
3278 return false;
3281 /* ... fall through ... */
3283 case ADDR_EXPR:
3284 case ARRAY_REF:
3285 case REALPART_EXPR:
3286 case IMAGPART_EXPR:
3287 x = TREE_OPERAND (x, 0);
3288 break;
3290 case COMPOUND_LITERAL_EXPR:
3291 case CONSTRUCTOR:
3292 TREE_ADDRESSABLE (x) = 1;
3293 return true;
3295 case VAR_DECL:
3296 case CONST_DECL:
3297 case PARM_DECL:
3298 case RESULT_DECL:
3299 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
3300 && DECL_NONLOCAL (x))
3302 if (TREE_PUBLIC (x))
3304 error ("global register variable `%s' used in nested function",
3305 IDENTIFIER_POINTER (DECL_NAME (x)));
3306 return false;
3308 pedwarn ("register variable `%s' used in nested function",
3309 IDENTIFIER_POINTER (DECL_NAME (x)));
3311 else if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x))
3313 if (TREE_PUBLIC (x))
3315 error ("address of global register variable `%s' requested",
3316 IDENTIFIER_POINTER (DECL_NAME (x)));
3317 return false;
3320 /* If we are making this addressable due to its having
3321 volatile components, give a different error message. Also
3322 handle the case of an unnamed parameter by not trying
3323 to give the name. */
3325 else if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (x)))
3327 error ("cannot put object with volatile field into register");
3328 return false;
3331 pedwarn ("address of register variable `%s' requested",
3332 IDENTIFIER_POINTER (DECL_NAME (x)));
3334 put_var_into_stack (x);
3336 /* drops in */
3337 case FUNCTION_DECL:
3338 TREE_ADDRESSABLE (x) = 1;
3339 #if 0 /* poplevel deals with this now. */
3340 if (DECL_CONTEXT (x) == 0)
3341 TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (x)) = 1;
3342 #endif
3344 default:
3345 return true;
3349 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3351 tree
3352 build_conditional_expr (ifexp, op1, op2)
3353 tree ifexp, op1, op2;
3355 tree type1;
3356 tree type2;
3357 enum tree_code code1;
3358 enum tree_code code2;
3359 tree result_type = NULL;
3360 tree orig_op1 = op1, orig_op2 = op2;
3362 ifexp = c_common_truthvalue_conversion (default_conversion (ifexp));
3364 #if 0 /* Produces wrong result if within sizeof. */
3365 /* Don't promote the operands separately if they promote
3366 the same way. Return the unpromoted type and let the combined
3367 value get promoted if necessary. */
3369 if (TREE_TYPE (op1) == TREE_TYPE (op2)
3370 && TREE_CODE (TREE_TYPE (op1)) != ARRAY_TYPE
3371 && TREE_CODE (TREE_TYPE (op1)) != ENUMERAL_TYPE
3372 && TREE_CODE (TREE_TYPE (op1)) != FUNCTION_TYPE)
3374 if (TREE_CODE (ifexp) == INTEGER_CST)
3375 return pedantic_non_lvalue (integer_zerop (ifexp) ? op2 : op1);
3377 return fold (build (COND_EXPR, TREE_TYPE (op1), ifexp, op1, op2));
3379 #endif
3381 /* Promote both alternatives. */
3383 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3384 op1 = default_conversion (op1);
3385 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3386 op2 = default_conversion (op2);
3388 if (TREE_CODE (ifexp) == ERROR_MARK
3389 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3390 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3391 return error_mark_node;
3393 type1 = TREE_TYPE (op1);
3394 code1 = TREE_CODE (type1);
3395 type2 = TREE_TYPE (op2);
3396 code2 = TREE_CODE (type2);
3398 /* Quickly detect the usual case where op1 and op2 have the same type
3399 after promotion. */
3400 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3402 if (type1 == type2)
3403 result_type = type1;
3404 else
3405 result_type = TYPE_MAIN_VARIANT (type1);
3407 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3408 || code1 == COMPLEX_TYPE)
3409 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3410 || code2 == COMPLEX_TYPE))
3412 result_type = common_type (type1, type2);
3414 /* If -Wsign-compare, warn here if type1 and type2 have
3415 different signedness. We'll promote the signed to unsigned
3416 and later code won't know it used to be different.
3417 Do this check on the original types, so that explicit casts
3418 will be considered, but default promotions won't. */
3419 if ((warn_sign_compare < 0 ? extra_warnings : warn_sign_compare)
3420 && !skip_evaluation)
3422 int unsigned_op1 = TREE_UNSIGNED (TREE_TYPE (orig_op1));
3423 int unsigned_op2 = TREE_UNSIGNED (TREE_TYPE (orig_op2));
3425 if (unsigned_op1 ^ unsigned_op2)
3427 /* Do not warn if the result type is signed, since the
3428 signed type will only be chosen if it can represent
3429 all the values of the unsigned type. */
3430 if (! TREE_UNSIGNED (result_type))
3431 /* OK */;
3432 /* Do not warn if the signed quantity is an unsuffixed
3433 integer literal (or some static constant expression
3434 involving such literals) and it is non-negative. */
3435 else if ((unsigned_op2 && c_tree_expr_nonnegative_p (op1))
3436 || (unsigned_op1 && c_tree_expr_nonnegative_p (op2)))
3437 /* OK */;
3438 else
3439 warning ("signed and unsigned type in conditional expression");
3443 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3445 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3446 pedwarn ("ISO C forbids conditional expr with only one void side");
3447 result_type = void_type_node;
3449 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3451 if (comp_target_types (type1, type2, 1))
3452 result_type = common_type (type1, type2);
3453 else if (integer_zerop (op1) && TREE_TYPE (type1) == void_type_node
3454 && TREE_CODE (orig_op1) != NOP_EXPR)
3455 result_type = qualify_type (type2, type1);
3456 else if (integer_zerop (op2) && TREE_TYPE (type2) == void_type_node
3457 && TREE_CODE (orig_op2) != NOP_EXPR)
3458 result_type = qualify_type (type1, type2);
3459 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3461 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3462 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer");
3463 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3464 TREE_TYPE (type2)));
3466 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3468 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3469 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer");
3470 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3471 TREE_TYPE (type1)));
3473 else
3475 pedwarn ("pointer type mismatch in conditional expression");
3476 result_type = build_pointer_type (void_type_node);
3479 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3481 if (! integer_zerop (op2))
3482 pedwarn ("pointer/integer type mismatch in conditional expression");
3483 else
3485 op2 = null_pointer_node;
3487 result_type = type1;
3489 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3491 if (!integer_zerop (op1))
3492 pedwarn ("pointer/integer type mismatch in conditional expression");
3493 else
3495 op1 = null_pointer_node;
3497 result_type = type2;
3500 if (!result_type)
3502 if (flag_cond_mismatch)
3503 result_type = void_type_node;
3504 else
3506 error ("type mismatch in conditional expression");
3507 return error_mark_node;
3511 /* Merge const and volatile flags of the incoming types. */
3512 result_type
3513 = build_type_variant (result_type,
3514 TREE_READONLY (op1) || TREE_READONLY (op2),
3515 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3517 if (result_type != TREE_TYPE (op1))
3518 op1 = convert_and_check (result_type, op1);
3519 if (result_type != TREE_TYPE (op2))
3520 op2 = convert_and_check (result_type, op2);
3522 if (TREE_CODE (ifexp) == INTEGER_CST)
3523 return pedantic_non_lvalue (integer_zerop (ifexp) ? op2 : op1);
3525 return fold (build (COND_EXPR, result_type, ifexp, op1, op2));
3528 /* Given a list of expressions, return a compound expression
3529 that performs them all and returns the value of the last of them. */
3531 tree
3532 build_compound_expr (list)
3533 tree list;
3535 return internal_build_compound_expr (list, TRUE);
3538 static tree
3539 internal_build_compound_expr (list, first_p)
3540 tree list;
3541 int first_p;
3543 tree rest;
3545 if (TREE_CHAIN (list) == 0)
3547 /* Convert arrays and functions to pointers when there
3548 really is a comma operator. */
3549 if (!first_p)
3550 TREE_VALUE (list)
3551 = default_function_array_conversion (TREE_VALUE (list));
3553 #if 0 /* If something inside inhibited lvalueness, we should not override. */
3554 /* Consider (x, y+0), which is not an lvalue since y+0 is not. */
3556 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3557 if (TREE_CODE (list) == NON_LVALUE_EXPR)
3558 list = TREE_OPERAND (list, 0);
3559 #endif
3561 /* Don't let (0, 0) be null pointer constant. */
3562 if (!first_p && integer_zerop (TREE_VALUE (list)))
3563 return non_lvalue (TREE_VALUE (list));
3564 return TREE_VALUE (list);
3567 rest = internal_build_compound_expr (TREE_CHAIN (list), FALSE);
3569 if (! TREE_SIDE_EFFECTS (TREE_VALUE (list)))
3571 /* The left-hand operand of a comma expression is like an expression
3572 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3573 any side-effects, unless it was explicitly cast to (void). */
3574 if ((extra_warnings || warn_unused_value)
3575 && ! (TREE_CODE (TREE_VALUE (list)) == CONVERT_EXPR
3576 && VOID_TYPE_P (TREE_TYPE (TREE_VALUE (list)))))
3577 warning ("left-hand operand of comma expression has no effect");
3579 /* When pedantic, a compound expression can be neither an lvalue
3580 nor an integer constant expression. */
3581 if (! pedantic)
3582 return rest;
3585 /* With -Wunused, we should also warn if the left-hand operand does have
3586 side-effects, but computes a value which is not used. For example, in
3587 `foo() + bar(), baz()' the result of the `+' operator is not used,
3588 so we should issue a warning. */
3589 else if (warn_unused_value)
3590 warn_if_unused_value (TREE_VALUE (list));
3592 return build (COMPOUND_EXPR, TREE_TYPE (rest), TREE_VALUE (list), rest);
3595 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3597 tree
3598 build_c_cast (type, expr)
3599 tree type;
3600 tree expr;
3602 tree value = expr;
3604 if (type == error_mark_node || expr == error_mark_node)
3605 return error_mark_node;
3607 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3608 only in <protocol> qualifications. But when constructing cast expressions,
3609 the protocols do matter and must be kept around. */
3610 if (!flag_objc || !objc_is_id (type))
3611 type = TYPE_MAIN_VARIANT (type);
3613 #if 0
3614 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3615 if (TREE_CODE (value) == NON_LVALUE_EXPR)
3616 value = TREE_OPERAND (value, 0);
3617 #endif
3619 if (TREE_CODE (type) == ARRAY_TYPE)
3621 error ("cast specifies array type");
3622 return error_mark_node;
3625 if (TREE_CODE (type) == FUNCTION_TYPE)
3627 error ("cast specifies function type");
3628 return error_mark_node;
3631 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3633 if (pedantic)
3635 if (TREE_CODE (type) == RECORD_TYPE
3636 || TREE_CODE (type) == UNION_TYPE)
3637 pedwarn ("ISO C forbids casting nonscalar to the same type");
3640 else if (TREE_CODE (type) == UNION_TYPE)
3642 tree field;
3643 value = default_function_array_conversion (value);
3645 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3646 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3647 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3648 break;
3650 if (field)
3652 tree t;
3654 if (pedantic)
3655 pedwarn ("ISO C forbids casts to union type");
3656 t = digest_init (type, build (CONSTRUCTOR, type, NULL_TREE,
3657 build_tree_list (field, value)), 0);
3658 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3659 return t;
3661 error ("cast to union type from type not present in union");
3662 return error_mark_node;
3664 else
3666 tree otype, ovalue;
3668 /* If casting to void, avoid the error that would come
3669 from default_conversion in the case of a non-lvalue array. */
3670 if (type == void_type_node)
3671 return build1 (CONVERT_EXPR, type, value);
3673 /* Convert functions and arrays to pointers,
3674 but don't convert any other types. */
3675 value = default_function_array_conversion (value);
3676 otype = TREE_TYPE (value);
3678 /* Optionally warn about potentially worrisome casts. */
3680 if (warn_cast_qual
3681 && TREE_CODE (type) == POINTER_TYPE
3682 && TREE_CODE (otype) == POINTER_TYPE)
3684 tree in_type = type;
3685 tree in_otype = otype;
3686 int added = 0;
3687 int discarded = 0;
3689 /* Check that the qualifiers on IN_TYPE are a superset of
3690 the qualifiers of IN_OTYPE. The outermost level of
3691 POINTER_TYPE nodes is uninteresting and we stop as soon
3692 as we hit a non-POINTER_TYPE node on either type. */
3695 in_otype = TREE_TYPE (in_otype);
3696 in_type = TREE_TYPE (in_type);
3698 /* GNU C allows cv-qualified function types. 'const'
3699 means the function is very pure, 'volatile' means it
3700 can't return. We need to warn when such qualifiers
3701 are added, not when they're taken away. */
3702 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3703 && TREE_CODE (in_type) == FUNCTION_TYPE)
3704 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3705 else
3706 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3708 while (TREE_CODE (in_type) == POINTER_TYPE
3709 && TREE_CODE (in_otype) == POINTER_TYPE);
3711 if (added)
3712 warning ("cast adds new qualifiers to function type");
3714 if (discarded)
3715 /* There are qualifiers present in IN_OTYPE that are not
3716 present in IN_TYPE. */
3717 warning ("cast discards qualifiers from pointer target type");
3720 /* Warn about possible alignment problems. */
3721 if (STRICT_ALIGNMENT && warn_cast_align
3722 && TREE_CODE (type) == POINTER_TYPE
3723 && TREE_CODE (otype) == POINTER_TYPE
3724 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3725 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3726 /* Don't warn about opaque types, where the actual alignment
3727 restriction is unknown. */
3728 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3729 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3730 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3731 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3732 warning ("cast increases required alignment of target type");
3734 if (TREE_CODE (type) == INTEGER_TYPE
3735 && TREE_CODE (otype) == POINTER_TYPE
3736 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3737 && !TREE_CONSTANT (value))
3738 warning ("cast from pointer to integer of different size");
3740 if (warn_bad_function_cast
3741 && TREE_CODE (value) == CALL_EXPR
3742 && TREE_CODE (type) != TREE_CODE (otype))
3743 warning ("cast does not match function type");
3745 if (TREE_CODE (type) == POINTER_TYPE
3746 && TREE_CODE (otype) == INTEGER_TYPE
3747 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3748 /* Don't warn about converting any constant. */
3749 && !TREE_CONSTANT (value))
3750 warning ("cast to pointer from integer of different size");
3752 if (TREE_CODE (type) == POINTER_TYPE
3753 && TREE_CODE (otype) == POINTER_TYPE
3754 && TREE_CODE (expr) == ADDR_EXPR
3755 && DECL_P (TREE_OPERAND (expr, 0))
3756 && flag_strict_aliasing && warn_strict_aliasing
3757 && !VOID_TYPE_P (TREE_TYPE (type)))
3759 /* Casting the address of a decl to non void pointer. Warn
3760 if the cast breaks type based aliasing. */
3761 if (!COMPLETE_TYPE_P (TREE_TYPE (type)))
3762 warning ("type-punning to incomplete type might break strict-aliasing rules");
3763 else if (!alias_sets_conflict_p
3764 (get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))),
3765 get_alias_set (TREE_TYPE (type))))
3766 warning ("dereferencing type-punned pointer will break strict-aliasing rules");
3769 ovalue = value;
3770 value = convert (type, value);
3772 /* Ignore any integer overflow caused by the cast. */
3773 if (TREE_CODE (value) == INTEGER_CST)
3775 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3776 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
3780 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3781 if (pedantic && TREE_CODE (value) == INTEGER_CST
3782 && TREE_CODE (expr) == INTEGER_CST
3783 && TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE)
3784 value = non_lvalue (value);
3786 /* If pedantic, don't let a cast be an lvalue. */
3787 if (value == expr && pedantic)
3788 value = non_lvalue (value);
3790 return value;
3793 /* Interpret a cast of expression EXPR to type TYPE. */
3794 tree
3795 c_cast_expr (type, expr)
3796 tree type, expr;
3798 int saved_wsp = warn_strict_prototypes;
3800 /* This avoids warnings about unprototyped casts on
3801 integers. E.g. "#define SIG_DFL (void(*)())0". */
3802 if (TREE_CODE (expr) == INTEGER_CST)
3803 warn_strict_prototypes = 0;
3804 type = groktypename (type);
3805 warn_strict_prototypes = saved_wsp;
3807 return build_c_cast (type, expr);
3811 /* Build an assignment expression of lvalue LHS from value RHS.
3812 MODIFYCODE is the code for a binary operator that we use
3813 to combine the old value of LHS with RHS to get the new value.
3814 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3816 tree
3817 build_modify_expr (lhs, modifycode, rhs)
3818 tree lhs, rhs;
3819 enum tree_code modifycode;
3821 tree result;
3822 tree newrhs;
3823 tree lhstype = TREE_TYPE (lhs);
3824 tree olhstype = lhstype;
3826 /* Types that aren't fully specified cannot be used in assignments. */
3827 lhs = require_complete_type (lhs);
3829 /* Avoid duplicate error messages from operands that had errors. */
3830 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3831 return error_mark_node;
3833 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3834 /* Do not use STRIP_NOPS here. We do not want an enumerator
3835 whose value is 0 to count as a null pointer constant. */
3836 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
3837 rhs = TREE_OPERAND (rhs, 0);
3839 newrhs = rhs;
3841 /* Handle control structure constructs used as "lvalues". */
3843 switch (TREE_CODE (lhs))
3845 /* Handle (a, b) used as an "lvalue". */
3846 case COMPOUND_EXPR:
3847 pedantic_lvalue_warning (COMPOUND_EXPR);
3848 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1), modifycode, rhs);
3849 if (TREE_CODE (newrhs) == ERROR_MARK)
3850 return error_mark_node;
3851 return build (COMPOUND_EXPR, lhstype,
3852 TREE_OPERAND (lhs, 0), newrhs);
3854 /* Handle (a ? b : c) used as an "lvalue". */
3855 case COND_EXPR:
3856 pedantic_lvalue_warning (COND_EXPR);
3857 rhs = save_expr (rhs);
3859 /* Produce (a ? (b = rhs) : (c = rhs))
3860 except that the RHS goes through a save-expr
3861 so the code to compute it is only emitted once. */
3862 tree cond
3863 = build_conditional_expr (TREE_OPERAND (lhs, 0),
3864 build_modify_expr (TREE_OPERAND (lhs, 1),
3865 modifycode, rhs),
3866 build_modify_expr (TREE_OPERAND (lhs, 2),
3867 modifycode, rhs));
3868 if (TREE_CODE (cond) == ERROR_MARK)
3869 return cond;
3870 /* Make sure the code to compute the rhs comes out
3871 before the split. */
3872 return build (COMPOUND_EXPR, TREE_TYPE (lhs),
3873 /* But cast it to void to avoid an "unused" error. */
3874 convert (void_type_node, rhs), cond);
3876 default:
3877 break;
3880 /* If a binary op has been requested, combine the old LHS value with the RHS
3881 producing the value we should actually store into the LHS. */
3883 if (modifycode != NOP_EXPR)
3885 lhs = stabilize_reference (lhs);
3886 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3889 /* Handle a cast used as an "lvalue".
3890 We have already performed any binary operator using the value as cast.
3891 Now convert the result to the cast type of the lhs,
3892 and then true type of the lhs and store it there;
3893 then convert result back to the cast type to be the value
3894 of the assignment. */
3896 switch (TREE_CODE (lhs))
3898 case NOP_EXPR:
3899 case CONVERT_EXPR:
3900 case FLOAT_EXPR:
3901 case FIX_TRUNC_EXPR:
3902 case FIX_FLOOR_EXPR:
3903 case FIX_ROUND_EXPR:
3904 case FIX_CEIL_EXPR:
3905 newrhs = default_function_array_conversion (newrhs);
3907 tree inner_lhs = TREE_OPERAND (lhs, 0);
3908 tree result;
3909 result = build_modify_expr (inner_lhs, NOP_EXPR,
3910 convert (TREE_TYPE (inner_lhs),
3911 convert (lhstype, newrhs)));
3912 if (TREE_CODE (result) == ERROR_MARK)
3913 return result;
3914 pedantic_lvalue_warning (CONVERT_EXPR);
3915 return convert (TREE_TYPE (lhs), result);
3918 default:
3919 break;
3922 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
3923 Reject anything strange now. */
3925 if (!lvalue_or_else (lhs, "invalid lvalue in assignment"))
3926 return error_mark_node;
3928 /* Warn about storing in something that is `const'. */
3930 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3931 || ((TREE_CODE (lhstype) == RECORD_TYPE
3932 || TREE_CODE (lhstype) == UNION_TYPE)
3933 && C_TYPE_FIELDS_READONLY (lhstype)))
3934 readonly_warning (lhs, "assignment");
3936 /* If storing into a structure or union member,
3937 it has probably been given type `int'.
3938 Compute the type that would go with
3939 the actual amount of storage the member occupies. */
3941 if (TREE_CODE (lhs) == COMPONENT_REF
3942 && (TREE_CODE (lhstype) == INTEGER_TYPE
3943 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3944 || TREE_CODE (lhstype) == REAL_TYPE
3945 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3946 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3948 /* If storing in a field that is in actuality a short or narrower than one,
3949 we must store in the field in its actual type. */
3951 if (lhstype != TREE_TYPE (lhs))
3953 lhs = copy_node (lhs);
3954 TREE_TYPE (lhs) = lhstype;
3957 /* Convert new value to destination type. */
3959 newrhs = convert_for_assignment (lhstype, newrhs, _("assignment"),
3960 NULL_TREE, NULL_TREE, 0);
3961 if (TREE_CODE (newrhs) == ERROR_MARK)
3962 return error_mark_node;
3964 /* Scan operands */
3966 result = build (MODIFY_EXPR, lhstype, lhs, newrhs);
3967 TREE_SIDE_EFFECTS (result) = 1;
3969 /* If we got the LHS in a different type for storing in,
3970 convert the result back to the nominal type of LHS
3971 so that the value we return always has the same type
3972 as the LHS argument. */
3974 if (olhstype == TREE_TYPE (result))
3975 return result;
3976 return convert_for_assignment (olhstype, result, _("assignment"),
3977 NULL_TREE, NULL_TREE, 0);
3980 /* Convert value RHS to type TYPE as preparation for an assignment
3981 to an lvalue of type TYPE.
3982 The real work of conversion is done by `convert'.
3983 The purpose of this function is to generate error messages
3984 for assignments that are not allowed in C.
3985 ERRTYPE is a string to use in error messages:
3986 "assignment", "return", etc. If it is null, this is parameter passing
3987 for a function call (and different error messages are output).
3989 FUNNAME is the name of the function being called,
3990 as an IDENTIFIER_NODE, or null.
3991 PARMNUM is the number of the argument, for printing in error messages. */
3993 static tree
3994 convert_for_assignment (type, rhs, errtype, fundecl, funname, parmnum)
3995 tree type, rhs;
3996 const char *errtype;
3997 tree fundecl, funname;
3998 int parmnum;
4000 enum tree_code codel = TREE_CODE (type);
4001 tree rhstype;
4002 enum tree_code coder;
4004 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4005 /* Do not use STRIP_NOPS here. We do not want an enumerator
4006 whose value is 0 to count as a null pointer constant. */
4007 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
4008 rhs = TREE_OPERAND (rhs, 0);
4010 if (TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
4011 || TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE)
4012 rhs = default_conversion (rhs);
4013 else if (optimize && TREE_CODE (rhs) == VAR_DECL)
4014 rhs = decl_constant_value_for_broken_optimization (rhs);
4016 rhstype = TREE_TYPE (rhs);
4017 coder = TREE_CODE (rhstype);
4019 if (coder == ERROR_MARK)
4020 return error_mark_node;
4022 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
4024 overflow_warning (rhs);
4025 /* Check for Objective-C protocols. This will automatically
4026 issue a warning if there are protocol violations. No need to
4027 use the return value. */
4028 if (flag_objc)
4029 objc_comptypes (type, rhstype, 0);
4030 return rhs;
4033 if (coder == VOID_TYPE)
4035 error ("void value not ignored as it ought to be");
4036 return error_mark_node;
4038 /* A type converts to a reference to it.
4039 This code doesn't fully support references, it's just for the
4040 special case of va_start and va_copy. */
4041 if (codel == REFERENCE_TYPE
4042 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
4044 if (!lvalue_p (rhs))
4046 error ("cannot pass rvalue to reference parameter");
4047 return error_mark_node;
4049 if (!c_mark_addressable (rhs))
4050 return error_mark_node;
4051 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
4053 /* We already know that these two types are compatible, but they
4054 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4055 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4056 likely to be va_list, a typedef to __builtin_va_list, which
4057 is different enough that it will cause problems later. */
4058 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
4059 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
4061 rhs = build1 (NOP_EXPR, type, rhs);
4062 return rhs;
4064 /* Arithmetic types all interconvert, and enum is treated like int. */
4065 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
4066 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
4067 || codel == BOOLEAN_TYPE)
4068 && (coder == INTEGER_TYPE || coder == REAL_TYPE
4069 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
4070 || coder == BOOLEAN_TYPE))
4071 return convert_and_check (type, rhs);
4073 /* Conversion to a transparent union from its member types.
4074 This applies only to function arguments. */
4075 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) && ! errtype)
4077 tree memb_types;
4078 tree marginal_memb_type = 0;
4080 for (memb_types = TYPE_FIELDS (type); memb_types;
4081 memb_types = TREE_CHAIN (memb_types))
4083 tree memb_type = TREE_TYPE (memb_types);
4085 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
4086 TYPE_MAIN_VARIANT (rhstype)))
4087 break;
4089 if (TREE_CODE (memb_type) != POINTER_TYPE)
4090 continue;
4092 if (coder == POINTER_TYPE)
4094 tree ttl = TREE_TYPE (memb_type);
4095 tree ttr = TREE_TYPE (rhstype);
4097 /* Any non-function converts to a [const][volatile] void *
4098 and vice versa; otherwise, targets must be the same.
4099 Meanwhile, the lhs target must have all the qualifiers of
4100 the rhs. */
4101 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4102 || comp_target_types (memb_type, rhstype, 0))
4104 /* If this type won't generate any warnings, use it. */
4105 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
4106 || ((TREE_CODE (ttr) == FUNCTION_TYPE
4107 && TREE_CODE (ttl) == FUNCTION_TYPE)
4108 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4109 == TYPE_QUALS (ttr))
4110 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4111 == TYPE_QUALS (ttl))))
4112 break;
4114 /* Keep looking for a better type, but remember this one. */
4115 if (! marginal_memb_type)
4116 marginal_memb_type = memb_type;
4120 /* Can convert integer zero to any pointer type. */
4121 if (integer_zerop (rhs)
4122 || (TREE_CODE (rhs) == NOP_EXPR
4123 && integer_zerop (TREE_OPERAND (rhs, 0))))
4125 rhs = null_pointer_node;
4126 break;
4130 if (memb_types || marginal_memb_type)
4132 if (! memb_types)
4134 /* We have only a marginally acceptable member type;
4135 it needs a warning. */
4136 tree ttl = TREE_TYPE (marginal_memb_type);
4137 tree ttr = TREE_TYPE (rhstype);
4139 /* Const and volatile mean something different for function
4140 types, so the usual warnings are not appropriate. */
4141 if (TREE_CODE (ttr) == FUNCTION_TYPE
4142 && TREE_CODE (ttl) == FUNCTION_TYPE)
4144 /* Because const and volatile on functions are
4145 restrictions that say the function will not do
4146 certain things, it is okay to use a const or volatile
4147 function where an ordinary one is wanted, but not
4148 vice-versa. */
4149 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4150 warn_for_assignment ("%s makes qualified function pointer from unqualified",
4151 errtype, funname, parmnum);
4153 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4154 warn_for_assignment ("%s discards qualifiers from pointer target type",
4155 errtype, funname,
4156 parmnum);
4159 if (pedantic && ! DECL_IN_SYSTEM_HEADER (fundecl))
4160 pedwarn ("ISO C prohibits argument conversion to union type");
4162 return build1 (NOP_EXPR, type, rhs);
4166 /* Conversions among pointers */
4167 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4168 && (coder == codel))
4170 tree ttl = TREE_TYPE (type);
4171 tree ttr = TREE_TYPE (rhstype);
4173 /* Any non-function converts to a [const][volatile] void *
4174 and vice versa; otherwise, targets must be the same.
4175 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4176 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4177 || comp_target_types (type, rhstype, 0)
4178 || (c_common_unsigned_type (TYPE_MAIN_VARIANT (ttl))
4179 == c_common_unsigned_type (TYPE_MAIN_VARIANT (ttr))))
4181 if (pedantic
4182 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4184 (VOID_TYPE_P (ttr)
4185 /* Check TREE_CODE to catch cases like (void *) (char *) 0
4186 which are not ANSI null ptr constants. */
4187 && (!integer_zerop (rhs) || TREE_CODE (rhs) == NOP_EXPR)
4188 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4189 warn_for_assignment ("ISO C forbids %s between function pointer and `void *'",
4190 errtype, funname, parmnum);
4191 /* Const and volatile mean something different for function types,
4192 so the usual warnings are not appropriate. */
4193 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4194 && TREE_CODE (ttl) != FUNCTION_TYPE)
4196 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4197 warn_for_assignment ("%s discards qualifiers from pointer target type",
4198 errtype, funname, parmnum);
4199 /* If this is not a case of ignoring a mismatch in signedness,
4200 no warning. */
4201 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4202 || comp_target_types (type, rhstype, 0))
4204 /* If there is a mismatch, do warn. */
4205 else if (pedantic)
4206 warn_for_assignment ("pointer targets in %s differ in signedness",
4207 errtype, funname, parmnum);
4209 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4210 && TREE_CODE (ttr) == FUNCTION_TYPE)
4212 /* Because const and volatile on functions are restrictions
4213 that say the function will not do certain things,
4214 it is okay to use a const or volatile function
4215 where an ordinary one is wanted, but not vice-versa. */
4216 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4217 warn_for_assignment ("%s makes qualified function pointer from unqualified",
4218 errtype, funname, parmnum);
4221 else
4222 warn_for_assignment ("%s from incompatible pointer type",
4223 errtype, funname, parmnum);
4224 return convert (type, rhs);
4226 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4228 /* An explicit constant 0 can convert to a pointer,
4229 or one that results from arithmetic, even including
4230 a cast to integer type. */
4231 if (! (TREE_CODE (rhs) == INTEGER_CST && integer_zerop (rhs))
4233 ! (TREE_CODE (rhs) == NOP_EXPR
4234 && TREE_CODE (TREE_TYPE (rhs)) == INTEGER_TYPE
4235 && TREE_CODE (TREE_OPERAND (rhs, 0)) == INTEGER_CST
4236 && integer_zerop (TREE_OPERAND (rhs, 0))))
4238 warn_for_assignment ("%s makes pointer from integer without a cast",
4239 errtype, funname, parmnum);
4240 return convert (type, rhs);
4242 return null_pointer_node;
4244 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4246 warn_for_assignment ("%s makes integer from pointer without a cast",
4247 errtype, funname, parmnum);
4248 return convert (type, rhs);
4250 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4251 return convert (type, rhs);
4253 if (!errtype)
4255 if (funname)
4257 tree selector = objc_message_selector ();
4259 if (selector && parmnum > 2)
4260 error ("incompatible type for argument %d of `%s'",
4261 parmnum - 2, IDENTIFIER_POINTER (selector));
4262 else
4263 error ("incompatible type for argument %d of `%s'",
4264 parmnum, IDENTIFIER_POINTER (funname));
4266 else
4267 error ("incompatible type for argument %d of indirect function call",
4268 parmnum);
4270 else
4271 error ("incompatible types in %s", errtype);
4273 return error_mark_node;
4276 /* Convert VALUE for assignment into inlined parameter PARM. */
4278 tree
4279 c_convert_parm_for_inlining (parm, value, fn)
4280 tree parm, value, fn;
4282 tree ret, type;
4284 /* If FN was prototyped, the value has been converted already
4285 in convert_arguments. */
4286 if (! value || TYPE_ARG_TYPES (TREE_TYPE (fn)))
4287 return value;
4289 type = TREE_TYPE (parm);
4290 ret = convert_for_assignment (type, value,
4291 (char *) 0 /* arg passing */, fn,
4292 DECL_NAME (fn), 0);
4293 if (PROMOTE_PROTOTYPES
4294 && INTEGRAL_TYPE_P (type)
4295 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
4296 ret = default_conversion (ret);
4297 return ret;
4300 /* Print a warning using MSGID.
4301 It gets OPNAME as its one parameter.
4302 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
4303 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
4304 FUNCTION and ARGNUM are handled specially if we are building an
4305 Objective-C selector. */
4307 static void
4308 warn_for_assignment (msgid, opname, function, argnum)
4309 const char *msgid;
4310 const char *opname;
4311 tree function;
4312 int argnum;
4314 if (opname == 0)
4316 tree selector = objc_message_selector ();
4317 char * new_opname;
4319 if (selector && argnum > 2)
4321 function = selector;
4322 argnum -= 2;
4324 if (argnum == 0)
4326 if (function)
4328 /* Function name is known; supply it. */
4329 const char *const argstring = _("passing arg of `%s'");
4330 new_opname = (char *) alloca (IDENTIFIER_LENGTH (function)
4331 + strlen (argstring) + 1
4332 + 1);
4333 sprintf (new_opname, argstring,
4334 IDENTIFIER_POINTER (function));
4336 else
4338 /* Function name unknown (call through ptr). */
4339 const char *const argnofun = _("passing arg of pointer to function");
4340 new_opname = (char *) alloca (strlen (argnofun) + 1 + 1);
4341 sprintf (new_opname, argnofun);
4344 else if (function)
4346 /* Function name is known; supply it. */
4347 const char *const argstring = _("passing arg %d of `%s'");
4348 new_opname = (char *) alloca (IDENTIFIER_LENGTH (function)
4349 + strlen (argstring) + 1 + 25
4350 /*%d*/ + 1);
4351 sprintf (new_opname, argstring, argnum,
4352 IDENTIFIER_POINTER (function));
4354 else
4356 /* Function name unknown (call through ptr); just give arg number. */
4357 const char *const argnofun = _("passing arg %d of pointer to function");
4358 new_opname = (char *) alloca (strlen (argnofun) + 1 + 25 /*%d*/ + 1);
4359 sprintf (new_opname, argnofun, argnum);
4361 opname = new_opname;
4363 pedwarn (msgid, opname);
4366 /* If VALUE is a compound expr all of whose expressions are constant, then
4367 return its value. Otherwise, return error_mark_node.
4369 This is for handling COMPOUND_EXPRs as initializer elements
4370 which is allowed with a warning when -pedantic is specified. */
4372 static tree
4373 valid_compound_expr_initializer (value, endtype)
4374 tree value;
4375 tree endtype;
4377 if (TREE_CODE (value) == COMPOUND_EXPR)
4379 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4380 == error_mark_node)
4381 return error_mark_node;
4382 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4383 endtype);
4385 else if (! TREE_CONSTANT (value)
4386 && ! initializer_constant_valid_p (value, endtype))
4387 return error_mark_node;
4388 else
4389 return value;
4392 /* Perform appropriate conversions on the initial value of a variable,
4393 store it in the declaration DECL,
4394 and print any error messages that are appropriate.
4395 If the init is invalid, store an ERROR_MARK. */
4397 void
4398 store_init_value (decl, init)
4399 tree decl, init;
4401 tree value, type;
4403 /* If variable's type was invalidly declared, just ignore it. */
4405 type = TREE_TYPE (decl);
4406 if (TREE_CODE (type) == ERROR_MARK)
4407 return;
4409 /* Digest the specified initializer into an expression. */
4411 value = digest_init (type, init, TREE_STATIC (decl));
4413 /* Store the expression if valid; else report error. */
4415 #if 0
4416 /* Note that this is the only place we can detect the error
4417 in a case such as struct foo bar = (struct foo) { x, y };
4418 where there is one initial value which is a constructor expression. */
4419 if (value == error_mark_node)
4421 else if (TREE_STATIC (decl) && ! TREE_CONSTANT (value))
4423 error ("initializer for static variable is not constant");
4424 value = error_mark_node;
4426 else if (TREE_STATIC (decl)
4427 && initializer_constant_valid_p (value, TREE_TYPE (value)) == 0)
4429 error ("initializer for static variable uses complicated arithmetic");
4430 value = error_mark_node;
4432 else
4434 if (pedantic && TREE_CODE (value) == CONSTRUCTOR)
4436 if (! TREE_CONSTANT (value))
4437 pedwarn ("aggregate initializer is not constant");
4438 else if (! TREE_STATIC (value))
4439 pedwarn ("aggregate initializer uses complicated arithmetic");
4442 #endif
4444 if (warn_traditional && !in_system_header
4445 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && ! TREE_STATIC (decl))
4446 warning ("traditional C rejects automatic aggregate initialization");
4448 DECL_INITIAL (decl) = value;
4450 /* ANSI wants warnings about out-of-range constant initializers. */
4451 STRIP_TYPE_NOPS (value);
4452 constant_expression_warning (value);
4454 /* Check if we need to set array size from compound literal size. */
4455 if (TREE_CODE (type) == ARRAY_TYPE
4456 && TYPE_DOMAIN (type) == 0
4457 && value != error_mark_node)
4459 tree inside_init = init;
4461 if (TREE_CODE (init) == NON_LVALUE_EXPR)
4462 inside_init = TREE_OPERAND (init, 0);
4463 inside_init = fold (inside_init);
4465 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4467 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4469 if (TYPE_DOMAIN (TREE_TYPE (decl)))
4471 /* For int foo[] = (int [3]){1}; we need to set array size
4472 now since later on array initializer will be just the
4473 brace enclosed list of the compound literal. */
4474 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (decl));
4475 layout_type (type);
4476 layout_decl (decl, 0);
4482 /* Methods for storing and printing names for error messages. */
4484 /* Implement a spelling stack that allows components of a name to be pushed
4485 and popped. Each element on the stack is this structure. */
4487 struct spelling
4489 int kind;
4490 union
4492 int i;
4493 const char *s;
4494 } u;
4497 #define SPELLING_STRING 1
4498 #define SPELLING_MEMBER 2
4499 #define SPELLING_BOUNDS 3
4501 static struct spelling *spelling; /* Next stack element (unused). */
4502 static struct spelling *spelling_base; /* Spelling stack base. */
4503 static int spelling_size; /* Size of the spelling stack. */
4505 /* Macros to save and restore the spelling stack around push_... functions.
4506 Alternative to SAVE_SPELLING_STACK. */
4508 #define SPELLING_DEPTH() (spelling - spelling_base)
4509 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4511 /* Push an element on the spelling stack with type KIND and assign VALUE
4512 to MEMBER. */
4514 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4516 int depth = SPELLING_DEPTH (); \
4518 if (depth >= spelling_size) \
4520 spelling_size += 10; \
4521 if (spelling_base == 0) \
4522 spelling_base \
4523 = (struct spelling *) xmalloc (spelling_size * sizeof (struct spelling)); \
4524 else \
4525 spelling_base \
4526 = (struct spelling *) xrealloc (spelling_base, \
4527 spelling_size * sizeof (struct spelling)); \
4528 RESTORE_SPELLING_DEPTH (depth); \
4531 spelling->kind = (KIND); \
4532 spelling->MEMBER = (VALUE); \
4533 spelling++; \
4536 /* Push STRING on the stack. Printed literally. */
4538 static void
4539 push_string (string)
4540 const char *string;
4542 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4545 /* Push a member name on the stack. Printed as '.' STRING. */
4547 static void
4548 push_member_name (decl)
4549 tree decl;
4552 const char *const string
4553 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4554 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4557 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4559 static void
4560 push_array_bounds (bounds)
4561 int bounds;
4563 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4566 /* Compute the maximum size in bytes of the printed spelling. */
4568 static int
4569 spelling_length ()
4571 int size = 0;
4572 struct spelling *p;
4574 for (p = spelling_base; p < spelling; p++)
4576 if (p->kind == SPELLING_BOUNDS)
4577 size += 25;
4578 else
4579 size += strlen (p->u.s) + 1;
4582 return size;
4585 /* Print the spelling to BUFFER and return it. */
4587 static char *
4588 print_spelling (buffer)
4589 char *buffer;
4591 char *d = buffer;
4592 struct spelling *p;
4594 for (p = spelling_base; p < spelling; p++)
4595 if (p->kind == SPELLING_BOUNDS)
4597 sprintf (d, "[%d]", p->u.i);
4598 d += strlen (d);
4600 else
4602 const char *s;
4603 if (p->kind == SPELLING_MEMBER)
4604 *d++ = '.';
4605 for (s = p->u.s; (*d = *s++); d++)
4608 *d++ = '\0';
4609 return buffer;
4612 /* Issue an error message for a bad initializer component.
4613 MSGID identifies the message.
4614 The component name is taken from the spelling stack. */
4616 void
4617 error_init (msgid)
4618 const char *msgid;
4620 char *ofwhat;
4622 error ("%s", _(msgid));
4623 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4624 if (*ofwhat)
4625 error ("(near initialization for `%s')", ofwhat);
4628 /* Issue a pedantic warning for a bad initializer component.
4629 MSGID identifies the message.
4630 The component name is taken from the spelling stack. */
4632 void
4633 pedwarn_init (msgid)
4634 const char *msgid;
4636 char *ofwhat;
4638 pedwarn ("%s", _(msgid));
4639 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4640 if (*ofwhat)
4641 pedwarn ("(near initialization for `%s')", ofwhat);
4644 /* Issue a warning for a bad initializer component.
4645 MSGID identifies the message.
4646 The component name is taken from the spelling stack. */
4648 static void
4649 warning_init (msgid)
4650 const char *msgid;
4652 char *ofwhat;
4654 warning ("%s", _(msgid));
4655 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4656 if (*ofwhat)
4657 warning ("(near initialization for `%s')", ofwhat);
4660 /* Digest the parser output INIT as an initializer for type TYPE.
4661 Return a C expression of type TYPE to represent the initial value.
4663 REQUIRE_CONSTANT requests an error if non-constant initializers or
4664 elements are seen. */
4666 static tree
4667 digest_init (type, init, require_constant)
4668 tree type, init;
4669 int require_constant;
4671 enum tree_code code = TREE_CODE (type);
4672 tree inside_init = init;
4674 if (type == error_mark_node
4675 || init == error_mark_node
4676 || TREE_TYPE (init) == error_mark_node)
4677 return error_mark_node;
4679 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4680 /* Do not use STRIP_NOPS here. We do not want an enumerator
4681 whose value is 0 to count as a null pointer constant. */
4682 if (TREE_CODE (init) == NON_LVALUE_EXPR)
4683 inside_init = TREE_OPERAND (init, 0);
4685 inside_init = fold (inside_init);
4687 /* Initialization of an array of chars from a string constant
4688 optionally enclosed in braces. */
4690 if (code == ARRAY_TYPE)
4692 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4693 if ((typ1 == char_type_node
4694 || typ1 == signed_char_type_node
4695 || typ1 == unsigned_char_type_node
4696 || typ1 == unsigned_wchar_type_node
4697 || typ1 == signed_wchar_type_node)
4698 && ((inside_init && TREE_CODE (inside_init) == STRING_CST)))
4700 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4701 TYPE_MAIN_VARIANT (type)))
4702 return inside_init;
4704 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4705 != char_type_node)
4706 && TYPE_PRECISION (typ1) == TYPE_PRECISION (char_type_node))
4708 error_init ("char-array initialized from wide string");
4709 return error_mark_node;
4711 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4712 == char_type_node)
4713 && TYPE_PRECISION (typ1) != TYPE_PRECISION (char_type_node))
4715 error_init ("int-array initialized from non-wide string");
4716 return error_mark_node;
4719 TREE_TYPE (inside_init) = type;
4720 if (TYPE_DOMAIN (type) != 0
4721 && TYPE_SIZE (type) != 0
4722 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4723 /* Subtract 1 (or sizeof (wchar_t))
4724 because it's ok to ignore the terminating null char
4725 that is counted in the length of the constant. */
4726 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4727 TREE_STRING_LENGTH (inside_init)
4728 - ((TYPE_PRECISION (typ1)
4729 != TYPE_PRECISION (char_type_node))
4730 ? (TYPE_PRECISION (wchar_type_node)
4731 / BITS_PER_UNIT)
4732 : 1)))
4733 pedwarn_init ("initializer-string for array of chars is too long");
4735 return inside_init;
4739 /* Any type can be initialized
4740 from an expression of the same type, optionally with braces. */
4742 if (inside_init && TREE_TYPE (inside_init) != 0
4743 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4744 TYPE_MAIN_VARIANT (type))
4745 || (code == ARRAY_TYPE
4746 && comptypes (TREE_TYPE (inside_init), type))
4747 || (code == VECTOR_TYPE
4748 && comptypes (TREE_TYPE (inside_init), type))
4749 || (code == POINTER_TYPE
4750 && (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4751 || TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE)
4752 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4753 TREE_TYPE (type)))))
4755 if (code == POINTER_TYPE)
4756 inside_init = default_function_array_conversion (inside_init);
4758 if (require_constant && !flag_isoc99
4759 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4761 /* As an extension, allow initializing objects with static storage
4762 duration with compound literals (which are then treated just as
4763 the brace enclosed list they contain). */
4764 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4765 inside_init = DECL_INITIAL (decl);
4768 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4769 && TREE_CODE (inside_init) != CONSTRUCTOR)
4771 error_init ("array initialized from non-constant array expression");
4772 return error_mark_node;
4775 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4776 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4778 /* Compound expressions can only occur here if -pedantic or
4779 -pedantic-errors is specified. In the later case, we always want
4780 an error. In the former case, we simply want a warning. */
4781 if (require_constant && pedantic
4782 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4784 inside_init
4785 = valid_compound_expr_initializer (inside_init,
4786 TREE_TYPE (inside_init));
4787 if (inside_init == error_mark_node)
4788 error_init ("initializer element is not constant");
4789 else
4790 pedwarn_init ("initializer element is not constant");
4791 if (flag_pedantic_errors)
4792 inside_init = error_mark_node;
4794 else if (require_constant
4795 && (!TREE_CONSTANT (inside_init)
4796 /* This test catches things like `7 / 0' which
4797 result in an expression for which TREE_CONSTANT
4798 is true, but which is not actually something
4799 that is a legal constant. We really should not
4800 be using this function, because it is a part of
4801 the back-end. Instead, the expression should
4802 already have been turned into ERROR_MARK_NODE. */
4803 || !initializer_constant_valid_p (inside_init,
4804 TREE_TYPE (inside_init))))
4806 error_init ("initializer element is not constant");
4807 inside_init = error_mark_node;
4810 return inside_init;
4813 /* Handle scalar types, including conversions. */
4815 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4816 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE)
4818 /* Note that convert_for_assignment calls default_conversion
4819 for arrays and functions. We must not call it in the
4820 case where inside_init is a null pointer constant. */
4821 inside_init
4822 = convert_for_assignment (type, init, _("initialization"),
4823 NULL_TREE, NULL_TREE, 0);
4825 if (require_constant && ! TREE_CONSTANT (inside_init))
4827 error_init ("initializer element is not constant");
4828 inside_init = error_mark_node;
4830 else if (require_constant
4831 && initializer_constant_valid_p (inside_init, TREE_TYPE (inside_init)) == 0)
4833 error_init ("initializer element is not computable at load time");
4834 inside_init = error_mark_node;
4837 return inside_init;
4840 /* Come here only for records and arrays. */
4842 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4844 error_init ("variable-sized object may not be initialized");
4845 return error_mark_node;
4848 error_init ("invalid initializer");
4849 return error_mark_node;
4852 /* Handle initializers that use braces. */
4854 /* Type of object we are accumulating a constructor for.
4855 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4856 static tree constructor_type;
4858 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4859 left to fill. */
4860 static tree constructor_fields;
4862 /* For an ARRAY_TYPE, this is the specified index
4863 at which to store the next element we get. */
4864 static tree constructor_index;
4866 /* For an ARRAY_TYPE, this is the maximum index. */
4867 static tree constructor_max_index;
4869 /* For a RECORD_TYPE, this is the first field not yet written out. */
4870 static tree constructor_unfilled_fields;
4872 /* For an ARRAY_TYPE, this is the index of the first element
4873 not yet written out. */
4874 static tree constructor_unfilled_index;
4876 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4877 This is so we can generate gaps between fields, when appropriate. */
4878 static tree constructor_bit_index;
4880 /* If we are saving up the elements rather than allocating them,
4881 this is the list of elements so far (in reverse order,
4882 most recent first). */
4883 static tree constructor_elements;
4885 /* 1 if constructor should be incrementally stored into a constructor chain,
4886 0 if all the elements should be kept in AVL tree. */
4887 static int constructor_incremental;
4889 /* 1 if so far this constructor's elements are all compile-time constants. */
4890 static int constructor_constant;
4892 /* 1 if so far this constructor's elements are all valid address constants. */
4893 static int constructor_simple;
4895 /* 1 if this constructor is erroneous so far. */
4896 static int constructor_erroneous;
4898 /* 1 if have called defer_addressed_constants. */
4899 static int constructor_subconstants_deferred;
4901 /* Structure for managing pending initializer elements, organized as an
4902 AVL tree. */
4904 struct init_node
4906 struct init_node *left, *right;
4907 struct init_node *parent;
4908 int balance;
4909 tree purpose;
4910 tree value;
4913 /* Tree of pending elements at this constructor level.
4914 These are elements encountered out of order
4915 which belong at places we haven't reached yet in actually
4916 writing the output.
4917 Will never hold tree nodes across GC runs. */
4918 static struct init_node *constructor_pending_elts;
4920 /* The SPELLING_DEPTH of this constructor. */
4921 static int constructor_depth;
4923 /* 0 if implicitly pushing constructor levels is allowed. */
4924 int constructor_no_implicit = 0; /* 0 for C; 1 for some other languages. */
4926 static int require_constant_value;
4927 static int require_constant_elements;
4929 /* DECL node for which an initializer is being read.
4930 0 means we are reading a constructor expression
4931 such as (struct foo) {...}. */
4932 static tree constructor_decl;
4934 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4935 static const char *constructor_asmspec;
4937 /* Nonzero if this is an initializer for a top-level decl. */
4938 static int constructor_top_level;
4940 /* Nonzero if there were any member designators in this initializer. */
4941 static int constructor_designated;
4943 /* Nesting depth of designator list. */
4944 static int designator_depth;
4946 /* Nonzero if there were diagnosed errors in this designator list. */
4947 static int designator_errorneous;
4950 /* This stack has a level for each implicit or explicit level of
4951 structuring in the initializer, including the outermost one. It
4952 saves the values of most of the variables above. */
4954 struct constructor_range_stack;
4956 struct constructor_stack
4958 struct constructor_stack *next;
4959 tree type;
4960 tree fields;
4961 tree index;
4962 tree max_index;
4963 tree unfilled_index;
4964 tree unfilled_fields;
4965 tree bit_index;
4966 tree elements;
4967 struct init_node *pending_elts;
4968 int offset;
4969 int depth;
4970 /* If nonzero, this value should replace the entire
4971 constructor at this level. */
4972 tree replacement_value;
4973 struct constructor_range_stack *range_stack;
4974 char constant;
4975 char simple;
4976 char implicit;
4977 char erroneous;
4978 char outer;
4979 char incremental;
4980 char designated;
4983 struct constructor_stack *constructor_stack;
4985 /* This stack represents designators from some range designator up to
4986 the last designator in the list. */
4988 struct constructor_range_stack
4990 struct constructor_range_stack *next, *prev;
4991 struct constructor_stack *stack;
4992 tree range_start;
4993 tree index;
4994 tree range_end;
4995 tree fields;
4998 struct constructor_range_stack *constructor_range_stack;
5000 /* This stack records separate initializers that are nested.
5001 Nested initializers can't happen in ANSI C, but GNU C allows them
5002 in cases like { ... (struct foo) { ... } ... }. */
5004 struct initializer_stack
5006 struct initializer_stack *next;
5007 tree decl;
5008 const char *asmspec;
5009 struct constructor_stack *constructor_stack;
5010 struct constructor_range_stack *constructor_range_stack;
5011 tree elements;
5012 struct spelling *spelling;
5013 struct spelling *spelling_base;
5014 int spelling_size;
5015 char top_level;
5016 char require_constant_value;
5017 char require_constant_elements;
5018 char deferred;
5021 struct initializer_stack *initializer_stack;
5023 /* Prepare to parse and output the initializer for variable DECL. */
5025 void
5026 start_init (decl, asmspec_tree, top_level)
5027 tree decl;
5028 tree asmspec_tree;
5029 int top_level;
5031 const char *locus;
5032 struct initializer_stack *p
5033 = (struct initializer_stack *) xmalloc (sizeof (struct initializer_stack));
5034 const char *asmspec = 0;
5036 if (asmspec_tree)
5037 asmspec = TREE_STRING_POINTER (asmspec_tree);
5039 p->decl = constructor_decl;
5040 p->asmspec = constructor_asmspec;
5041 p->require_constant_value = require_constant_value;
5042 p->require_constant_elements = require_constant_elements;
5043 p->constructor_stack = constructor_stack;
5044 p->constructor_range_stack = constructor_range_stack;
5045 p->elements = constructor_elements;
5046 p->spelling = spelling;
5047 p->spelling_base = spelling_base;
5048 p->spelling_size = spelling_size;
5049 p->deferred = constructor_subconstants_deferred;
5050 p->top_level = constructor_top_level;
5051 p->next = initializer_stack;
5052 initializer_stack = p;
5054 constructor_decl = decl;
5055 constructor_asmspec = asmspec;
5056 constructor_subconstants_deferred = 0;
5057 constructor_designated = 0;
5058 constructor_top_level = top_level;
5060 if (decl != 0)
5062 require_constant_value = TREE_STATIC (decl);
5063 require_constant_elements
5064 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5065 /* For a scalar, you can always use any value to initialize,
5066 even within braces. */
5067 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5068 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5069 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5070 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5071 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5073 else
5075 require_constant_value = 0;
5076 require_constant_elements = 0;
5077 locus = "(anonymous)";
5080 constructor_stack = 0;
5081 constructor_range_stack = 0;
5083 missing_braces_mentioned = 0;
5085 spelling_base = 0;
5086 spelling_size = 0;
5087 RESTORE_SPELLING_DEPTH (0);
5089 if (locus)
5090 push_string (locus);
5093 void
5094 finish_init ()
5096 struct initializer_stack *p = initializer_stack;
5098 /* Output subconstants (string constants, usually)
5099 that were referenced within this initializer and saved up.
5100 Must do this if and only if we called defer_addressed_constants. */
5101 if (constructor_subconstants_deferred)
5102 output_deferred_addressed_constants ();
5104 /* Free the whole constructor stack of this initializer. */
5105 while (constructor_stack)
5107 struct constructor_stack *q = constructor_stack;
5108 constructor_stack = q->next;
5109 free (q);
5112 if (constructor_range_stack)
5113 abort ();
5115 /* Pop back to the data of the outer initializer (if any). */
5116 constructor_decl = p->decl;
5117 constructor_asmspec = p->asmspec;
5118 require_constant_value = p->require_constant_value;
5119 require_constant_elements = p->require_constant_elements;
5120 constructor_stack = p->constructor_stack;
5121 constructor_range_stack = p->constructor_range_stack;
5122 constructor_elements = p->elements;
5123 spelling = p->spelling;
5124 spelling_base = p->spelling_base;
5125 spelling_size = p->spelling_size;
5126 constructor_subconstants_deferred = p->deferred;
5127 constructor_top_level = p->top_level;
5128 initializer_stack = p->next;
5129 free (p);
5132 /* Call here when we see the initializer is surrounded by braces.
5133 This is instead of a call to push_init_level;
5134 it is matched by a call to pop_init_level.
5136 TYPE is the type to initialize, for a constructor expression.
5137 For an initializer for a decl, TYPE is zero. */
5139 void
5140 really_start_incremental_init (type)
5141 tree type;
5143 struct constructor_stack *p
5144 = (struct constructor_stack *) xmalloc (sizeof (struct constructor_stack));
5146 if (type == 0)
5147 type = TREE_TYPE (constructor_decl);
5149 p->type = constructor_type;
5150 p->fields = constructor_fields;
5151 p->index = constructor_index;
5152 p->max_index = constructor_max_index;
5153 p->unfilled_index = constructor_unfilled_index;
5154 p->unfilled_fields = constructor_unfilled_fields;
5155 p->bit_index = constructor_bit_index;
5156 p->elements = constructor_elements;
5157 p->constant = constructor_constant;
5158 p->simple = constructor_simple;
5159 p->erroneous = constructor_erroneous;
5160 p->pending_elts = constructor_pending_elts;
5161 p->depth = constructor_depth;
5162 p->replacement_value = 0;
5163 p->implicit = 0;
5164 p->range_stack = 0;
5165 p->outer = 0;
5166 p->incremental = constructor_incremental;
5167 p->designated = constructor_designated;
5168 p->next = 0;
5169 constructor_stack = p;
5171 constructor_constant = 1;
5172 constructor_simple = 1;
5173 constructor_depth = SPELLING_DEPTH ();
5174 constructor_elements = 0;
5175 constructor_pending_elts = 0;
5176 constructor_type = type;
5177 constructor_incremental = 1;
5178 constructor_designated = 0;
5179 designator_depth = 0;
5180 designator_errorneous = 0;
5182 if (TREE_CODE (constructor_type) == RECORD_TYPE
5183 || TREE_CODE (constructor_type) == UNION_TYPE)
5185 constructor_fields = TYPE_FIELDS (constructor_type);
5186 /* Skip any nameless bit fields at the beginning. */
5187 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5188 && DECL_NAME (constructor_fields) == 0)
5189 constructor_fields = TREE_CHAIN (constructor_fields);
5191 constructor_unfilled_fields = constructor_fields;
5192 constructor_bit_index = bitsize_zero_node;
5194 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5196 if (TYPE_DOMAIN (constructor_type))
5198 constructor_max_index
5199 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5201 /* Detect non-empty initializations of zero-length arrays. */
5202 if (constructor_max_index == NULL_TREE
5203 && TYPE_SIZE (constructor_type))
5204 constructor_max_index = build_int_2 (-1, -1);
5206 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5207 to initialize VLAs will cause a proper error; avoid tree
5208 checking errors as well by setting a safe value. */
5209 if (constructor_max_index
5210 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5211 constructor_max_index = build_int_2 (-1, -1);
5213 constructor_index
5214 = convert (bitsizetype,
5215 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5217 else
5218 constructor_index = bitsize_zero_node;
5220 constructor_unfilled_index = constructor_index;
5222 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5224 /* Vectors are like simple fixed-size arrays. */
5225 constructor_max_index =
5226 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0);
5227 constructor_index = convert (bitsizetype, bitsize_zero_node);
5228 constructor_unfilled_index = constructor_index;
5230 else
5232 /* Handle the case of int x = {5}; */
5233 constructor_fields = constructor_type;
5234 constructor_unfilled_fields = constructor_type;
5238 /* Push down into a subobject, for initialization.
5239 If this is for an explicit set of braces, IMPLICIT is 0.
5240 If it is because the next element belongs at a lower level,
5241 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5243 void
5244 push_init_level (implicit)
5245 int implicit;
5247 struct constructor_stack *p;
5248 tree value = NULL_TREE;
5250 /* If we've exhausted any levels that didn't have braces,
5251 pop them now. */
5252 while (constructor_stack->implicit)
5254 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5255 || TREE_CODE (constructor_type) == UNION_TYPE)
5256 && constructor_fields == 0)
5257 process_init_element (pop_init_level (1));
5258 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5259 && tree_int_cst_lt (constructor_max_index, constructor_index))
5260 process_init_element (pop_init_level (1));
5261 else
5262 break;
5265 /* Unless this is an explicit brace, we need to preserve previous
5266 content if any. */
5267 if (implicit)
5269 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5270 || TREE_CODE (constructor_type) == UNION_TYPE)
5271 && constructor_fields)
5272 value = find_init_member (constructor_fields);
5273 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5274 value = find_init_member (constructor_index);
5277 p = (struct constructor_stack *) xmalloc (sizeof (struct constructor_stack));
5278 p->type = constructor_type;
5279 p->fields = constructor_fields;
5280 p->index = constructor_index;
5281 p->max_index = constructor_max_index;
5282 p->unfilled_index = constructor_unfilled_index;
5283 p->unfilled_fields = constructor_unfilled_fields;
5284 p->bit_index = constructor_bit_index;
5285 p->elements = constructor_elements;
5286 p->constant = constructor_constant;
5287 p->simple = constructor_simple;
5288 p->erroneous = constructor_erroneous;
5289 p->pending_elts = constructor_pending_elts;
5290 p->depth = constructor_depth;
5291 p->replacement_value = 0;
5292 p->implicit = implicit;
5293 p->outer = 0;
5294 p->incremental = constructor_incremental;
5295 p->designated = constructor_designated;
5296 p->next = constructor_stack;
5297 p->range_stack = 0;
5298 constructor_stack = p;
5300 constructor_constant = 1;
5301 constructor_simple = 1;
5302 constructor_depth = SPELLING_DEPTH ();
5303 constructor_elements = 0;
5304 constructor_incremental = 1;
5305 constructor_designated = 0;
5306 constructor_pending_elts = 0;
5307 if (!implicit)
5309 p->range_stack = constructor_range_stack;
5310 constructor_range_stack = 0;
5311 designator_depth = 0;
5312 designator_errorneous = 0;
5315 /* Don't die if an entire brace-pair level is superfluous
5316 in the containing level. */
5317 if (constructor_type == 0)
5319 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5320 || TREE_CODE (constructor_type) == UNION_TYPE)
5322 /* Don't die if there are extra init elts at the end. */
5323 if (constructor_fields == 0)
5324 constructor_type = 0;
5325 else
5327 constructor_type = TREE_TYPE (constructor_fields);
5328 push_member_name (constructor_fields);
5329 constructor_depth++;
5332 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5334 constructor_type = TREE_TYPE (constructor_type);
5335 push_array_bounds (tree_low_cst (constructor_index, 0));
5336 constructor_depth++;
5339 if (constructor_type == 0)
5341 error_init ("extra brace group at end of initializer");
5342 constructor_fields = 0;
5343 constructor_unfilled_fields = 0;
5344 return;
5347 if (value && TREE_CODE (value) == CONSTRUCTOR)
5349 constructor_constant = TREE_CONSTANT (value);
5350 constructor_simple = TREE_STATIC (value);
5351 constructor_elements = TREE_OPERAND (value, 1);
5352 if (constructor_elements
5353 && (TREE_CODE (constructor_type) == RECORD_TYPE
5354 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5355 set_nonincremental_init ();
5358 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5360 missing_braces_mentioned = 1;
5361 warning_init ("missing braces around initializer");
5364 if (TREE_CODE (constructor_type) == RECORD_TYPE
5365 || TREE_CODE (constructor_type) == UNION_TYPE)
5367 constructor_fields = TYPE_FIELDS (constructor_type);
5368 /* Skip any nameless bit fields at the beginning. */
5369 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5370 && DECL_NAME (constructor_fields) == 0)
5371 constructor_fields = TREE_CHAIN (constructor_fields);
5373 constructor_unfilled_fields = constructor_fields;
5374 constructor_bit_index = bitsize_zero_node;
5376 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5378 /* Vectors are like simple fixed-size arrays. */
5379 constructor_max_index =
5380 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0);
5381 constructor_index = convert (bitsizetype, integer_zero_node);
5382 constructor_unfilled_index = constructor_index;
5384 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5386 if (TYPE_DOMAIN (constructor_type))
5388 constructor_max_index
5389 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5391 /* Detect non-empty initializations of zero-length arrays. */
5392 if (constructor_max_index == NULL_TREE
5393 && TYPE_SIZE (constructor_type))
5394 constructor_max_index = build_int_2 (-1, -1);
5396 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5397 to initialize VLAs will cause a proper error; avoid tree
5398 checking errors as well by setting a safe value. */
5399 if (constructor_max_index
5400 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5401 constructor_max_index = build_int_2 (-1, -1);
5403 constructor_index
5404 = convert (bitsizetype,
5405 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5407 else
5408 constructor_index = bitsize_zero_node;
5410 constructor_unfilled_index = constructor_index;
5411 if (value && TREE_CODE (value) == STRING_CST)
5413 /* We need to split the char/wchar array into individual
5414 characters, so that we don't have to special case it
5415 everywhere. */
5416 set_nonincremental_init_from_string (value);
5419 else
5421 warning_init ("braces around scalar initializer");
5422 constructor_fields = constructor_type;
5423 constructor_unfilled_fields = constructor_type;
5427 /* At the end of an implicit or explicit brace level,
5428 finish up that level of constructor.
5429 If we were outputting the elements as they are read, return 0
5430 from inner levels (process_init_element ignores that),
5431 but return error_mark_node from the outermost level
5432 (that's what we want to put in DECL_INITIAL).
5433 Otherwise, return a CONSTRUCTOR expression. */
5435 tree
5436 pop_init_level (implicit)
5437 int implicit;
5439 struct constructor_stack *p;
5440 tree constructor = 0;
5442 if (implicit == 0)
5444 /* When we come to an explicit close brace,
5445 pop any inner levels that didn't have explicit braces. */
5446 while (constructor_stack->implicit)
5447 process_init_element (pop_init_level (1));
5449 if (constructor_range_stack)
5450 abort ();
5453 p = constructor_stack;
5455 /* Error for initializing a flexible array member, or a zero-length
5456 array member in an inappropriate context. */
5457 if (constructor_type && constructor_fields
5458 && TREE_CODE (constructor_type) == ARRAY_TYPE
5459 && TYPE_DOMAIN (constructor_type)
5460 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5462 /* Silently discard empty initializations. The parser will
5463 already have pedwarned for empty brackets. */
5464 if (integer_zerop (constructor_unfilled_index))
5465 constructor_type = NULL_TREE;
5466 else if (! TYPE_SIZE (constructor_type))
5468 if (constructor_depth > 2)
5469 error_init ("initialization of flexible array member in a nested context");
5470 else if (pedantic)
5471 pedwarn_init ("initialization of a flexible array member");
5473 /* We have already issued an error message for the existence
5474 of a flexible array member not at the end of the structure.
5475 Discard the initializer so that we do not abort later. */
5476 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5477 constructor_type = NULL_TREE;
5479 else
5480 /* Zero-length arrays are no longer special, so we should no longer
5481 get here. */
5482 abort ();
5485 /* Warn when some struct elements are implicitly initialized to zero. */
5486 if (extra_warnings
5487 && constructor_type
5488 && TREE_CODE (constructor_type) == RECORD_TYPE
5489 && constructor_unfilled_fields)
5491 /* Do not warn for flexible array members or zero-length arrays. */
5492 while (constructor_unfilled_fields
5493 && (! DECL_SIZE (constructor_unfilled_fields)
5494 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5495 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5497 /* Do not warn if this level of the initializer uses member
5498 designators; it is likely to be deliberate. */
5499 if (constructor_unfilled_fields && !constructor_designated)
5501 push_member_name (constructor_unfilled_fields);
5502 warning_init ("missing initializer");
5503 RESTORE_SPELLING_DEPTH (constructor_depth);
5507 /* Now output all pending elements. */
5508 constructor_incremental = 1;
5509 output_pending_init_elements (1);
5511 /* Pad out the end of the structure. */
5512 if (p->replacement_value)
5513 /* If this closes a superfluous brace pair,
5514 just pass out the element between them. */
5515 constructor = p->replacement_value;
5516 else if (constructor_type == 0)
5518 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5519 && TREE_CODE (constructor_type) != UNION_TYPE
5520 && TREE_CODE (constructor_type) != ARRAY_TYPE
5521 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5523 /* A nonincremental scalar initializer--just return
5524 the element, after verifying there is just one. */
5525 if (constructor_elements == 0)
5527 if (!constructor_erroneous)
5528 error_init ("empty scalar initializer");
5529 constructor = error_mark_node;
5531 else if (TREE_CHAIN (constructor_elements) != 0)
5533 error_init ("extra elements in scalar initializer");
5534 constructor = TREE_VALUE (constructor_elements);
5536 else
5537 constructor = TREE_VALUE (constructor_elements);
5539 else
5541 if (constructor_erroneous)
5542 constructor = error_mark_node;
5543 else
5545 constructor = build (CONSTRUCTOR, constructor_type, NULL_TREE,
5546 nreverse (constructor_elements));
5547 if (constructor_constant)
5548 TREE_CONSTANT (constructor) = 1;
5549 if (constructor_constant && constructor_simple)
5550 TREE_STATIC (constructor) = 1;
5554 constructor_type = p->type;
5555 constructor_fields = p->fields;
5556 constructor_index = p->index;
5557 constructor_max_index = p->max_index;
5558 constructor_unfilled_index = p->unfilled_index;
5559 constructor_unfilled_fields = p->unfilled_fields;
5560 constructor_bit_index = p->bit_index;
5561 constructor_elements = p->elements;
5562 constructor_constant = p->constant;
5563 constructor_simple = p->simple;
5564 constructor_erroneous = p->erroneous;
5565 constructor_incremental = p->incremental;
5566 constructor_designated = p->designated;
5567 constructor_pending_elts = p->pending_elts;
5568 constructor_depth = p->depth;
5569 if (!p->implicit)
5570 constructor_range_stack = p->range_stack;
5571 RESTORE_SPELLING_DEPTH (constructor_depth);
5573 constructor_stack = p->next;
5574 free (p);
5576 if (constructor == 0)
5578 if (constructor_stack == 0)
5579 return error_mark_node;
5580 return NULL_TREE;
5582 return constructor;
5585 /* Common handling for both array range and field name designators.
5586 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5588 static int
5589 set_designator (array)
5590 int array;
5592 tree subtype;
5593 enum tree_code subcode;
5595 /* Don't die if an entire brace-pair level is superfluous
5596 in the containing level. */
5597 if (constructor_type == 0)
5598 return 1;
5600 /* If there were errors in this designator list already, bail out silently. */
5601 if (designator_errorneous)
5602 return 1;
5604 if (!designator_depth)
5606 if (constructor_range_stack)
5607 abort ();
5609 /* Designator list starts at the level of closest explicit
5610 braces. */
5611 while (constructor_stack->implicit)
5612 process_init_element (pop_init_level (1));
5613 constructor_designated = 1;
5614 return 0;
5617 if (constructor_no_implicit)
5619 error_init ("initialization designators may not nest");
5620 return 1;
5623 if (TREE_CODE (constructor_type) == RECORD_TYPE
5624 || TREE_CODE (constructor_type) == UNION_TYPE)
5626 subtype = TREE_TYPE (constructor_fields);
5627 if (subtype != error_mark_node)
5628 subtype = TYPE_MAIN_VARIANT (subtype);
5630 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5632 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5634 else
5635 abort ();
5637 subcode = TREE_CODE (subtype);
5638 if (array && subcode != ARRAY_TYPE)
5640 error_init ("array index in non-array initializer");
5641 return 1;
5643 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5645 error_init ("field name not in record or union initializer");
5646 return 1;
5649 constructor_designated = 1;
5650 push_init_level (2);
5651 return 0;
5654 /* If there are range designators in designator list, push a new designator
5655 to constructor_range_stack. RANGE_END is end of such stack range or
5656 NULL_TREE if there is no range designator at this level. */
5658 static void
5659 push_range_stack (range_end)
5660 tree range_end;
5662 struct constructor_range_stack *p;
5664 p = (struct constructor_range_stack *)
5665 ggc_alloc (sizeof (struct constructor_range_stack));
5666 p->prev = constructor_range_stack;
5667 p->next = 0;
5668 p->fields = constructor_fields;
5669 p->range_start = constructor_index;
5670 p->index = constructor_index;
5671 p->stack = constructor_stack;
5672 p->range_end = range_end;
5673 if (constructor_range_stack)
5674 constructor_range_stack->next = p;
5675 constructor_range_stack = p;
5678 /* Within an array initializer, specify the next index to be initialized.
5679 FIRST is that index. If LAST is nonzero, then initialize a range
5680 of indices, running from FIRST through LAST. */
5682 void
5683 set_init_index (first, last)
5684 tree first, last;
5686 if (set_designator (1))
5687 return;
5689 designator_errorneous = 1;
5691 while ((TREE_CODE (first) == NOP_EXPR
5692 || TREE_CODE (first) == CONVERT_EXPR
5693 || TREE_CODE (first) == NON_LVALUE_EXPR)
5694 && (TYPE_MODE (TREE_TYPE (first))
5695 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (first, 0)))))
5696 first = TREE_OPERAND (first, 0);
5698 if (last)
5699 while ((TREE_CODE (last) == NOP_EXPR
5700 || TREE_CODE (last) == CONVERT_EXPR
5701 || TREE_CODE (last) == NON_LVALUE_EXPR)
5702 && (TYPE_MODE (TREE_TYPE (last))
5703 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (last, 0)))))
5704 last = TREE_OPERAND (last, 0);
5706 if (TREE_CODE (first) != INTEGER_CST)
5707 error_init ("nonconstant array index in initializer");
5708 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5709 error_init ("nonconstant array index in initializer");
5710 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5711 error_init ("array index in non-array initializer");
5712 else if (constructor_max_index
5713 && tree_int_cst_lt (constructor_max_index, first))
5714 error_init ("array index in initializer exceeds array bounds");
5715 else
5717 constructor_index = convert (bitsizetype, first);
5719 if (last)
5721 if (tree_int_cst_equal (first, last))
5722 last = 0;
5723 else if (tree_int_cst_lt (last, first))
5725 error_init ("empty index range in initializer");
5726 last = 0;
5728 else
5730 last = convert (bitsizetype, last);
5731 if (constructor_max_index != 0
5732 && tree_int_cst_lt (constructor_max_index, last))
5734 error_init ("array index range in initializer exceeds array bounds");
5735 last = 0;
5740 designator_depth++;
5741 designator_errorneous = 0;
5742 if (constructor_range_stack || last)
5743 push_range_stack (last);
5747 /* Within a struct initializer, specify the next field to be initialized. */
5749 void
5750 set_init_label (fieldname)
5751 tree fieldname;
5753 tree tail;
5755 if (set_designator (0))
5756 return;
5758 designator_errorneous = 1;
5760 if (TREE_CODE (constructor_type) != RECORD_TYPE
5761 && TREE_CODE (constructor_type) != UNION_TYPE)
5763 error_init ("field name not in record or union initializer");
5764 return;
5767 for (tail = TYPE_FIELDS (constructor_type); tail;
5768 tail = TREE_CHAIN (tail))
5770 if (DECL_NAME (tail) == fieldname)
5771 break;
5774 if (tail == 0)
5775 error ("unknown field `%s' specified in initializer",
5776 IDENTIFIER_POINTER (fieldname));
5777 else
5779 constructor_fields = tail;
5780 designator_depth++;
5781 designator_errorneous = 0;
5782 if (constructor_range_stack)
5783 push_range_stack (NULL_TREE);
5787 /* Add a new initializer to the tree of pending initializers. PURPOSE
5788 identifies the initializer, either array index or field in a structure.
5789 VALUE is the value of that index or field. */
5791 static void
5792 add_pending_init (purpose, value)
5793 tree purpose, value;
5795 struct init_node *p, **q, *r;
5797 q = &constructor_pending_elts;
5798 p = 0;
5800 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5802 while (*q != 0)
5804 p = *q;
5805 if (tree_int_cst_lt (purpose, p->purpose))
5806 q = &p->left;
5807 else if (tree_int_cst_lt (p->purpose, purpose))
5808 q = &p->right;
5809 else
5811 if (TREE_SIDE_EFFECTS (p->value))
5812 warning_init ("initialized field with side-effects overwritten");
5813 p->value = value;
5814 return;
5818 else
5820 tree bitpos;
5822 bitpos = bit_position (purpose);
5823 while (*q != NULL)
5825 p = *q;
5826 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5827 q = &p->left;
5828 else if (p->purpose != purpose)
5829 q = &p->right;
5830 else
5832 if (TREE_SIDE_EFFECTS (p->value))
5833 warning_init ("initialized field with side-effects overwritten");
5834 p->value = value;
5835 return;
5840 r = (struct init_node *) ggc_alloc (sizeof (struct init_node));
5841 r->purpose = purpose;
5842 r->value = value;
5844 *q = r;
5845 r->parent = p;
5846 r->left = 0;
5847 r->right = 0;
5848 r->balance = 0;
5850 while (p)
5852 struct init_node *s;
5854 if (r == p->left)
5856 if (p->balance == 0)
5857 p->balance = -1;
5858 else if (p->balance < 0)
5860 if (r->balance < 0)
5862 /* L rotation. */
5863 p->left = r->right;
5864 if (p->left)
5865 p->left->parent = p;
5866 r->right = p;
5868 p->balance = 0;
5869 r->balance = 0;
5871 s = p->parent;
5872 p->parent = r;
5873 r->parent = s;
5874 if (s)
5876 if (s->left == p)
5877 s->left = r;
5878 else
5879 s->right = r;
5881 else
5882 constructor_pending_elts = r;
5884 else
5886 /* LR rotation. */
5887 struct init_node *t = r->right;
5889 r->right = t->left;
5890 if (r->right)
5891 r->right->parent = r;
5892 t->left = r;
5894 p->left = t->right;
5895 if (p->left)
5896 p->left->parent = p;
5897 t->right = p;
5899 p->balance = t->balance < 0;
5900 r->balance = -(t->balance > 0);
5901 t->balance = 0;
5903 s = p->parent;
5904 p->parent = t;
5905 r->parent = t;
5906 t->parent = s;
5907 if (s)
5909 if (s->left == p)
5910 s->left = t;
5911 else
5912 s->right = t;
5914 else
5915 constructor_pending_elts = t;
5917 break;
5919 else
5921 /* p->balance == +1; growth of left side balances the node. */
5922 p->balance = 0;
5923 break;
5926 else /* r == p->right */
5928 if (p->balance == 0)
5929 /* Growth propagation from right side. */
5930 p->balance++;
5931 else if (p->balance > 0)
5933 if (r->balance > 0)
5935 /* R rotation. */
5936 p->right = r->left;
5937 if (p->right)
5938 p->right->parent = p;
5939 r->left = p;
5941 p->balance = 0;
5942 r->balance = 0;
5944 s = p->parent;
5945 p->parent = r;
5946 r->parent = s;
5947 if (s)
5949 if (s->left == p)
5950 s->left = r;
5951 else
5952 s->right = r;
5954 else
5955 constructor_pending_elts = r;
5957 else /* r->balance == -1 */
5959 /* RL rotation */
5960 struct init_node *t = r->left;
5962 r->left = t->right;
5963 if (r->left)
5964 r->left->parent = r;
5965 t->right = r;
5967 p->right = t->left;
5968 if (p->right)
5969 p->right->parent = p;
5970 t->left = p;
5972 r->balance = (t->balance < 0);
5973 p->balance = -(t->balance > 0);
5974 t->balance = 0;
5976 s = p->parent;
5977 p->parent = t;
5978 r->parent = t;
5979 t->parent = s;
5980 if (s)
5982 if (s->left == p)
5983 s->left = t;
5984 else
5985 s->right = t;
5987 else
5988 constructor_pending_elts = t;
5990 break;
5992 else
5994 /* p->balance == -1; growth of right side balances the node. */
5995 p->balance = 0;
5996 break;
6000 r = p;
6001 p = p->parent;
6005 /* Build AVL tree from a sorted chain. */
6007 static void
6008 set_nonincremental_init ()
6010 tree chain;
6012 if (TREE_CODE (constructor_type) != RECORD_TYPE
6013 && TREE_CODE (constructor_type) != ARRAY_TYPE)
6014 return;
6016 for (chain = constructor_elements; chain; chain = TREE_CHAIN (chain))
6017 add_pending_init (TREE_PURPOSE (chain), TREE_VALUE (chain));
6018 constructor_elements = 0;
6019 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6021 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
6022 /* Skip any nameless bit fields at the beginning. */
6023 while (constructor_unfilled_fields != 0
6024 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6025 && DECL_NAME (constructor_unfilled_fields) == 0)
6026 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
6029 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6031 if (TYPE_DOMAIN (constructor_type))
6032 constructor_unfilled_index
6033 = convert (bitsizetype,
6034 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
6035 else
6036 constructor_unfilled_index = bitsize_zero_node;
6038 constructor_incremental = 0;
6041 /* Build AVL tree from a string constant. */
6043 static void
6044 set_nonincremental_init_from_string (str)
6045 tree str;
6047 tree value, purpose, type;
6048 HOST_WIDE_INT val[2];
6049 const char *p, *end;
6050 int byte, wchar_bytes, charwidth, bitpos;
6052 if (TREE_CODE (constructor_type) != ARRAY_TYPE)
6053 abort ();
6055 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
6056 == TYPE_PRECISION (char_type_node))
6057 wchar_bytes = 1;
6058 else if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
6059 == TYPE_PRECISION (wchar_type_node))
6060 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
6061 else
6062 abort ();
6064 charwidth = TYPE_PRECISION (char_type_node);
6065 type = TREE_TYPE (constructor_type);
6066 p = TREE_STRING_POINTER (str);
6067 end = p + TREE_STRING_LENGTH (str);
6069 for (purpose = bitsize_zero_node;
6070 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6071 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6073 if (wchar_bytes == 1)
6075 val[1] = (unsigned char) *p++;
6076 val[0] = 0;
6078 else
6080 val[0] = 0;
6081 val[1] = 0;
6082 for (byte = 0; byte < wchar_bytes; byte++)
6084 if (BYTES_BIG_ENDIAN)
6085 bitpos = (wchar_bytes - byte - 1) * charwidth;
6086 else
6087 bitpos = byte * charwidth;
6088 val[bitpos < HOST_BITS_PER_WIDE_INT]
6089 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6090 << (bitpos % HOST_BITS_PER_WIDE_INT);
6094 if (!TREE_UNSIGNED (type))
6096 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6097 if (bitpos < HOST_BITS_PER_WIDE_INT)
6099 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6101 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6102 val[0] = -1;
6105 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6107 if (val[1] < 0)
6108 val[0] = -1;
6110 else if (val[0] & (((HOST_WIDE_INT) 1)
6111 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6112 val[0] |= ((HOST_WIDE_INT) -1)
6113 << (bitpos - HOST_BITS_PER_WIDE_INT);
6116 value = build_int_2 (val[1], val[0]);
6117 TREE_TYPE (value) = type;
6118 add_pending_init (purpose, value);
6121 constructor_incremental = 0;
6124 /* Return value of FIELD in pending initializer or zero if the field was
6125 not initialized yet. */
6127 static tree
6128 find_init_member (field)
6129 tree field;
6131 struct init_node *p;
6133 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6135 if (constructor_incremental
6136 && tree_int_cst_lt (field, constructor_unfilled_index))
6137 set_nonincremental_init ();
6139 p = constructor_pending_elts;
6140 while (p)
6142 if (tree_int_cst_lt (field, p->purpose))
6143 p = p->left;
6144 else if (tree_int_cst_lt (p->purpose, field))
6145 p = p->right;
6146 else
6147 return p->value;
6150 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6152 tree bitpos = bit_position (field);
6154 if (constructor_incremental
6155 && (!constructor_unfilled_fields
6156 || tree_int_cst_lt (bitpos,
6157 bit_position (constructor_unfilled_fields))))
6158 set_nonincremental_init ();
6160 p = constructor_pending_elts;
6161 while (p)
6163 if (field == p->purpose)
6164 return p->value;
6165 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6166 p = p->left;
6167 else
6168 p = p->right;
6171 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6173 if (constructor_elements
6174 && TREE_PURPOSE (constructor_elements) == field)
6175 return TREE_VALUE (constructor_elements);
6177 return 0;
6180 /* "Output" the next constructor element.
6181 At top level, really output it to assembler code now.
6182 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6183 TYPE is the data type that the containing data type wants here.
6184 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6186 PENDING if non-nil means output pending elements that belong
6187 right after this element. (PENDING is normally 1;
6188 it is 0 while outputting pending elements, to avoid recursion.) */
6190 static void
6191 output_init_element (value, type, field, pending)
6192 tree value, type, field;
6193 int pending;
6195 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
6196 || (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6197 && !(TREE_CODE (value) == STRING_CST
6198 && TREE_CODE (type) == ARRAY_TYPE
6199 && TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE)
6200 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6201 TYPE_MAIN_VARIANT (type))))
6202 value = default_conversion (value);
6204 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6205 && require_constant_value && !flag_isoc99 && pending)
6207 /* As an extension, allow initializing objects with static storage
6208 duration with compound literals (which are then treated just as
6209 the brace enclosed list they contain). */
6210 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6211 value = DECL_INITIAL (decl);
6214 if (value == error_mark_node)
6215 constructor_erroneous = 1;
6216 else if (!TREE_CONSTANT (value))
6217 constructor_constant = 0;
6218 else if (initializer_constant_valid_p (value, TREE_TYPE (value)) == 0
6219 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6220 || TREE_CODE (constructor_type) == UNION_TYPE)
6221 && DECL_C_BIT_FIELD (field)
6222 && TREE_CODE (value) != INTEGER_CST))
6223 constructor_simple = 0;
6225 if (require_constant_value && ! TREE_CONSTANT (value))
6227 error_init ("initializer element is not constant");
6228 value = error_mark_node;
6230 else if (require_constant_elements
6231 && initializer_constant_valid_p (value, TREE_TYPE (value)) == 0)
6232 pedwarn ("initializer element is not computable at load time");
6234 /* If this field is empty (and not at the end of structure),
6235 don't do anything other than checking the initializer. */
6236 if (field
6237 && (TREE_TYPE (field) == error_mark_node
6238 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6239 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6240 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6241 || TREE_CHAIN (field)))))
6242 return;
6244 value = digest_init (type, value, require_constant_value);
6245 if (value == error_mark_node)
6247 constructor_erroneous = 1;
6248 return;
6251 /* If this element doesn't come next in sequence,
6252 put it on constructor_pending_elts. */
6253 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6254 && (!constructor_incremental
6255 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6257 if (constructor_incremental
6258 && tree_int_cst_lt (field, constructor_unfilled_index))
6259 set_nonincremental_init ();
6261 add_pending_init (field, value);
6262 return;
6264 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6265 && (!constructor_incremental
6266 || field != constructor_unfilled_fields))
6268 /* We do this for records but not for unions. In a union,
6269 no matter which field is specified, it can be initialized
6270 right away since it starts at the beginning of the union. */
6271 if (constructor_incremental)
6273 if (!constructor_unfilled_fields)
6274 set_nonincremental_init ();
6275 else
6277 tree bitpos, unfillpos;
6279 bitpos = bit_position (field);
6280 unfillpos = bit_position (constructor_unfilled_fields);
6282 if (tree_int_cst_lt (bitpos, unfillpos))
6283 set_nonincremental_init ();
6287 add_pending_init (field, value);
6288 return;
6290 else if (TREE_CODE (constructor_type) == UNION_TYPE
6291 && constructor_elements)
6293 if (TREE_SIDE_EFFECTS (TREE_VALUE (constructor_elements)))
6294 warning_init ("initialized field with side-effects overwritten");
6296 /* We can have just one union field set. */
6297 constructor_elements = 0;
6300 /* Otherwise, output this element either to
6301 constructor_elements or to the assembler file. */
6303 if (field && TREE_CODE (field) == INTEGER_CST)
6304 field = copy_node (field);
6305 constructor_elements
6306 = tree_cons (field, value, constructor_elements);
6308 /* Advance the variable that indicates sequential elements output. */
6309 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6310 constructor_unfilled_index
6311 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6312 bitsize_one_node);
6313 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6315 constructor_unfilled_fields
6316 = TREE_CHAIN (constructor_unfilled_fields);
6318 /* Skip any nameless bit fields. */
6319 while (constructor_unfilled_fields != 0
6320 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6321 && DECL_NAME (constructor_unfilled_fields) == 0)
6322 constructor_unfilled_fields =
6323 TREE_CHAIN (constructor_unfilled_fields);
6325 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6326 constructor_unfilled_fields = 0;
6328 /* Now output any pending elements which have become next. */
6329 if (pending)
6330 output_pending_init_elements (0);
6333 /* Output any pending elements which have become next.
6334 As we output elements, constructor_unfilled_{fields,index}
6335 advances, which may cause other elements to become next;
6336 if so, they too are output.
6338 If ALL is 0, we return when there are
6339 no more pending elements to output now.
6341 If ALL is 1, we output space as necessary so that
6342 we can output all the pending elements. */
6344 static void
6345 output_pending_init_elements (all)
6346 int all;
6348 struct init_node *elt = constructor_pending_elts;
6349 tree next;
6351 retry:
6353 /* Look thru the whole pending tree.
6354 If we find an element that should be output now,
6355 output it. Otherwise, set NEXT to the element
6356 that comes first among those still pending. */
6358 next = 0;
6359 while (elt)
6361 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6363 if (tree_int_cst_equal (elt->purpose,
6364 constructor_unfilled_index))
6365 output_init_element (elt->value,
6366 TREE_TYPE (constructor_type),
6367 constructor_unfilled_index, 0);
6368 else if (tree_int_cst_lt (constructor_unfilled_index,
6369 elt->purpose))
6371 /* Advance to the next smaller node. */
6372 if (elt->left)
6373 elt = elt->left;
6374 else
6376 /* We have reached the smallest node bigger than the
6377 current unfilled index. Fill the space first. */
6378 next = elt->purpose;
6379 break;
6382 else
6384 /* Advance to the next bigger node. */
6385 if (elt->right)
6386 elt = elt->right;
6387 else
6389 /* We have reached the biggest node in a subtree. Find
6390 the parent of it, which is the next bigger node. */
6391 while (elt->parent && elt->parent->right == elt)
6392 elt = elt->parent;
6393 elt = elt->parent;
6394 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6395 elt->purpose))
6397 next = elt->purpose;
6398 break;
6403 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6404 || TREE_CODE (constructor_type) == UNION_TYPE)
6406 tree ctor_unfilled_bitpos, elt_bitpos;
6408 /* If the current record is complete we are done. */
6409 if (constructor_unfilled_fields == 0)
6410 break;
6412 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6413 elt_bitpos = bit_position (elt->purpose);
6414 /* We can't compare fields here because there might be empty
6415 fields in between. */
6416 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6418 constructor_unfilled_fields = elt->purpose;
6419 output_init_element (elt->value, TREE_TYPE (elt->purpose),
6420 elt->purpose, 0);
6422 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6424 /* Advance to the next smaller node. */
6425 if (elt->left)
6426 elt = elt->left;
6427 else
6429 /* We have reached the smallest node bigger than the
6430 current unfilled field. Fill the space first. */
6431 next = elt->purpose;
6432 break;
6435 else
6437 /* Advance to the next bigger node. */
6438 if (elt->right)
6439 elt = elt->right;
6440 else
6442 /* We have reached the biggest node in a subtree. Find
6443 the parent of it, which is the next bigger node. */
6444 while (elt->parent && elt->parent->right == elt)
6445 elt = elt->parent;
6446 elt = elt->parent;
6447 if (elt
6448 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6449 bit_position (elt->purpose))))
6451 next = elt->purpose;
6452 break;
6459 /* Ordinarily return, but not if we want to output all
6460 and there are elements left. */
6461 if (! (all && next != 0))
6462 return;
6464 /* If it's not incremental, just skip over the gap, so that after
6465 jumping to retry we will output the next successive element. */
6466 if (TREE_CODE (constructor_type) == RECORD_TYPE
6467 || TREE_CODE (constructor_type) == UNION_TYPE)
6468 constructor_unfilled_fields = next;
6469 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6470 constructor_unfilled_index = next;
6472 /* ELT now points to the node in the pending tree with the next
6473 initializer to output. */
6474 goto retry;
6477 /* Add one non-braced element to the current constructor level.
6478 This adjusts the current position within the constructor's type.
6479 This may also start or terminate implicit levels
6480 to handle a partly-braced initializer.
6482 Once this has found the correct level for the new element,
6483 it calls output_init_element. */
6485 void
6486 process_init_element (value)
6487 tree value;
6489 tree orig_value = value;
6490 int string_flag = value != 0 && TREE_CODE (value) == STRING_CST;
6492 designator_depth = 0;
6493 designator_errorneous = 0;
6495 /* Handle superfluous braces around string cst as in
6496 char x[] = {"foo"}; */
6497 if (string_flag
6498 && constructor_type
6499 && TREE_CODE (constructor_type) == ARRAY_TYPE
6500 && TREE_CODE (TREE_TYPE (constructor_type)) == INTEGER_TYPE
6501 && integer_zerop (constructor_unfilled_index))
6503 if (constructor_stack->replacement_value)
6504 error_init ("excess elements in char array initializer");
6505 constructor_stack->replacement_value = value;
6506 return;
6509 if (constructor_stack->replacement_value != 0)
6511 error_init ("excess elements in struct initializer");
6512 return;
6515 /* Ignore elements of a brace group if it is entirely superfluous
6516 and has already been diagnosed. */
6517 if (constructor_type == 0)
6518 return;
6520 /* If we've exhausted any levels that didn't have braces,
6521 pop them now. */
6522 while (constructor_stack->implicit)
6524 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6525 || TREE_CODE (constructor_type) == UNION_TYPE)
6526 && constructor_fields == 0)
6527 process_init_element (pop_init_level (1));
6528 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6529 && (constructor_max_index == 0
6530 || tree_int_cst_lt (constructor_max_index,
6531 constructor_index)))
6532 process_init_element (pop_init_level (1));
6533 else
6534 break;
6537 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6538 if (constructor_range_stack)
6540 /* If value is a compound literal and we'll be just using its
6541 content, don't put it into a SAVE_EXPR. */
6542 if (TREE_CODE (value) != COMPOUND_LITERAL_EXPR
6543 || !require_constant_value
6544 || flag_isoc99)
6545 value = save_expr (value);
6548 while (1)
6550 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6552 tree fieldtype;
6553 enum tree_code fieldcode;
6555 if (constructor_fields == 0)
6557 pedwarn_init ("excess elements in struct initializer");
6558 break;
6561 fieldtype = TREE_TYPE (constructor_fields);
6562 if (fieldtype != error_mark_node)
6563 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6564 fieldcode = TREE_CODE (fieldtype);
6566 /* Error for non-static initialization of a flexible array member. */
6567 if (fieldcode == ARRAY_TYPE
6568 && !require_constant_value
6569 && TYPE_SIZE (fieldtype) == NULL_TREE
6570 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6572 error_init ("non-static initialization of a flexible array member");
6573 break;
6576 /* Accept a string constant to initialize a subarray. */
6577 if (value != 0
6578 && fieldcode == ARRAY_TYPE
6579 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE
6580 && string_flag)
6581 value = orig_value;
6582 /* Otherwise, if we have come to a subaggregate,
6583 and we don't have an element of its type, push into it. */
6584 else if (value != 0 && !constructor_no_implicit
6585 && value != error_mark_node
6586 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype
6587 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6588 || fieldcode == UNION_TYPE))
6590 push_init_level (1);
6591 continue;
6594 if (value)
6596 push_member_name (constructor_fields);
6597 output_init_element (value, fieldtype, constructor_fields, 1);
6598 RESTORE_SPELLING_DEPTH (constructor_depth);
6600 else
6601 /* Do the bookkeeping for an element that was
6602 directly output as a constructor. */
6604 /* For a record, keep track of end position of last field. */
6605 if (DECL_SIZE (constructor_fields))
6606 constructor_bit_index
6607 = size_binop (PLUS_EXPR,
6608 bit_position (constructor_fields),
6609 DECL_SIZE (constructor_fields));
6611 /* If the current field was the first one not yet written out,
6612 it isn't now, so update. */
6613 if (constructor_unfilled_fields == constructor_fields)
6615 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6616 /* Skip any nameless bit fields. */
6617 while (constructor_unfilled_fields != 0
6618 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6619 && DECL_NAME (constructor_unfilled_fields) == 0)
6620 constructor_unfilled_fields =
6621 TREE_CHAIN (constructor_unfilled_fields);
6625 constructor_fields = TREE_CHAIN (constructor_fields);
6626 /* Skip any nameless bit fields at the beginning. */
6627 while (constructor_fields != 0
6628 && DECL_C_BIT_FIELD (constructor_fields)
6629 && DECL_NAME (constructor_fields) == 0)
6630 constructor_fields = TREE_CHAIN (constructor_fields);
6632 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6634 tree fieldtype;
6635 enum tree_code fieldcode;
6637 if (constructor_fields == 0)
6639 pedwarn_init ("excess elements in union initializer");
6640 break;
6643 fieldtype = TREE_TYPE (constructor_fields);
6644 if (fieldtype != error_mark_node)
6645 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6646 fieldcode = TREE_CODE (fieldtype);
6648 /* Warn that traditional C rejects initialization of unions.
6649 We skip the warning if the value is zero. This is done
6650 under the assumption that the zero initializer in user
6651 code appears conditioned on e.g. __STDC__ to avoid
6652 "missing initializer" warnings and relies on default
6653 initialization to zero in the traditional C case.
6654 We also skip the warning if the initializer is designated,
6655 again on the assumption that this must be conditional on
6656 __STDC__ anyway (and we've already complained about the
6657 member-designator already). */
6658 if (warn_traditional && !in_system_header && !constructor_designated
6659 && !(value && (integer_zerop (value) || real_zerop (value))))
6660 warning ("traditional C rejects initialization of unions");
6662 /* Accept a string constant to initialize a subarray. */
6663 if (value != 0
6664 && fieldcode == ARRAY_TYPE
6665 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE
6666 && string_flag)
6667 value = orig_value;
6668 /* Otherwise, if we have come to a subaggregate,
6669 and we don't have an element of its type, push into it. */
6670 else if (value != 0 && !constructor_no_implicit
6671 && value != error_mark_node
6672 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype
6673 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6674 || fieldcode == UNION_TYPE))
6676 push_init_level (1);
6677 continue;
6680 if (value)
6682 push_member_name (constructor_fields);
6683 output_init_element (value, fieldtype, constructor_fields, 1);
6684 RESTORE_SPELLING_DEPTH (constructor_depth);
6686 else
6687 /* Do the bookkeeping for an element that was
6688 directly output as a constructor. */
6690 constructor_bit_index = DECL_SIZE (constructor_fields);
6691 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6694 constructor_fields = 0;
6696 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6698 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6699 enum tree_code eltcode = TREE_CODE (elttype);
6701 /* Accept a string constant to initialize a subarray. */
6702 if (value != 0
6703 && eltcode == ARRAY_TYPE
6704 && TREE_CODE (TREE_TYPE (elttype)) == INTEGER_TYPE
6705 && string_flag)
6706 value = orig_value;
6707 /* Otherwise, if we have come to a subaggregate,
6708 and we don't have an element of its type, push into it. */
6709 else if (value != 0 && !constructor_no_implicit
6710 && value != error_mark_node
6711 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != elttype
6712 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6713 || eltcode == UNION_TYPE))
6715 push_init_level (1);
6716 continue;
6719 if (constructor_max_index != 0
6720 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6721 || integer_all_onesp (constructor_max_index)))
6723 pedwarn_init ("excess elements in array initializer");
6724 break;
6727 /* Now output the actual element. */
6728 if (value)
6730 push_array_bounds (tree_low_cst (constructor_index, 0));
6731 output_init_element (value, elttype, constructor_index, 1);
6732 RESTORE_SPELLING_DEPTH (constructor_depth);
6735 constructor_index
6736 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6738 if (! value)
6739 /* If we are doing the bookkeeping for an element that was
6740 directly output as a constructor, we must update
6741 constructor_unfilled_index. */
6742 constructor_unfilled_index = constructor_index;
6744 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6746 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6748 /* Do a basic check of initializer size. Note that vectors
6749 always have a fixed size derived from their type. */
6750 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6752 pedwarn_init ("excess elements in vector initializer");
6753 break;
6756 /* Now output the actual element. */
6757 if (value)
6758 output_init_element (value, elttype, constructor_index, 1);
6760 constructor_index
6761 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6763 if (! value)
6764 /* If we are doing the bookkeeping for an element that was
6765 directly output as a constructor, we must update
6766 constructor_unfilled_index. */
6767 constructor_unfilled_index = constructor_index;
6770 /* Handle the sole element allowed in a braced initializer
6771 for a scalar variable. */
6772 else if (constructor_fields == 0)
6774 pedwarn_init ("excess elements in scalar initializer");
6775 break;
6777 else
6779 if (value)
6780 output_init_element (value, constructor_type, NULL_TREE, 1);
6781 constructor_fields = 0;
6784 /* Handle range initializers either at this level or anywhere higher
6785 in the designator stack. */
6786 if (constructor_range_stack)
6788 struct constructor_range_stack *p, *range_stack;
6789 int finish = 0;
6791 range_stack = constructor_range_stack;
6792 constructor_range_stack = 0;
6793 while (constructor_stack != range_stack->stack)
6795 if (!constructor_stack->implicit)
6796 abort ();
6797 process_init_element (pop_init_level (1));
6799 for (p = range_stack;
6800 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6801 p = p->prev)
6803 if (!constructor_stack->implicit)
6804 abort ();
6805 process_init_element (pop_init_level (1));
6808 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6809 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6810 finish = 1;
6812 while (1)
6814 constructor_index = p->index;
6815 constructor_fields = p->fields;
6816 if (finish && p->range_end && p->index == p->range_start)
6818 finish = 0;
6819 p->prev = 0;
6821 p = p->next;
6822 if (!p)
6823 break;
6824 push_init_level (2);
6825 p->stack = constructor_stack;
6826 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6827 p->index = p->range_start;
6830 if (!finish)
6831 constructor_range_stack = range_stack;
6832 continue;
6835 break;
6838 constructor_range_stack = 0;
6841 /* Build a simple asm-statement, from one string literal. */
6842 tree
6843 simple_asm_stmt (expr)
6844 tree expr;
6846 STRIP_NOPS (expr);
6848 if (TREE_CODE (expr) == ADDR_EXPR)
6849 expr = TREE_OPERAND (expr, 0);
6851 if (TREE_CODE (expr) == STRING_CST)
6853 tree stmt;
6855 /* Simple asm statements are treated as volatile. */
6856 stmt = add_stmt (build_stmt (ASM_STMT, ridpointers[(int) RID_VOLATILE],
6857 expr, NULL_TREE, NULL_TREE, NULL_TREE));
6858 ASM_INPUT_P (stmt) = 1;
6859 return stmt;
6862 error ("argument of `asm' is not a constant string");
6863 return NULL_TREE;
6866 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6867 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6869 tree
6870 build_asm_stmt (cv_qualifier, string, outputs, inputs, clobbers)
6871 tree cv_qualifier;
6872 tree string;
6873 tree outputs;
6874 tree inputs;
6875 tree clobbers;
6877 tree tail;
6879 if (TREE_CODE (string) != STRING_CST)
6881 error ("asm template is not a string constant");
6882 return NULL_TREE;
6885 if (cv_qualifier != NULL_TREE
6886 && cv_qualifier != ridpointers[(int) RID_VOLATILE])
6888 warning ("%s qualifier ignored on asm",
6889 IDENTIFIER_POINTER (cv_qualifier));
6890 cv_qualifier = NULL_TREE;
6893 /* We can remove output conversions that change the type,
6894 but not the mode. */
6895 for (tail = outputs; tail; tail = TREE_CHAIN (tail))
6897 tree output = TREE_VALUE (tail);
6899 STRIP_NOPS (output);
6900 TREE_VALUE (tail) = output;
6902 /* Allow conversions as LHS here. build_modify_expr as called below
6903 will do the right thing with them. */
6904 while (TREE_CODE (output) == NOP_EXPR
6905 || TREE_CODE (output) == CONVERT_EXPR
6906 || TREE_CODE (output) == FLOAT_EXPR
6907 || TREE_CODE (output) == FIX_TRUNC_EXPR
6908 || TREE_CODE (output) == FIX_FLOOR_EXPR
6909 || TREE_CODE (output) == FIX_ROUND_EXPR
6910 || TREE_CODE (output) == FIX_CEIL_EXPR)
6911 output = TREE_OPERAND (output, 0);
6913 lvalue_or_else (TREE_VALUE (tail), "invalid lvalue in asm statement");
6916 /* Remove output conversions that change the type but not the mode. */
6917 for (tail = outputs; tail; tail = TREE_CHAIN (tail))
6919 tree output = TREE_VALUE (tail);
6920 STRIP_NOPS (output);
6921 TREE_VALUE (tail) = output;
6924 /* Perform default conversions on array and function inputs.
6925 Don't do this for other types as it would screw up operands
6926 expected to be in memory. */
6927 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
6928 TREE_VALUE (tail) = default_function_array_conversion (TREE_VALUE (tail));
6930 return add_stmt (build_stmt (ASM_STMT, cv_qualifier, string,
6931 outputs, inputs, clobbers));
6934 /* Expand an ASM statement with operands, handling output operands
6935 that are not variables or INDIRECT_REFS by transforming such
6936 cases into cases that expand_asm_operands can handle.
6938 Arguments are same as for expand_asm_operands. */
6940 void
6941 c_expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
6942 tree string, outputs, inputs, clobbers;
6943 int vol;
6944 const char *filename;
6945 int line;
6947 int noutputs = list_length (outputs);
6948 int i;
6949 /* o[I] is the place that output number I should be written. */
6950 tree *o = (tree *) alloca (noutputs * sizeof (tree));
6951 tree tail;
6953 /* Record the contents of OUTPUTS before it is modified. */
6954 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
6956 o[i] = TREE_VALUE (tail);
6957 if (o[i] == error_mark_node)
6958 return;
6961 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6962 OUTPUTS some trees for where the values were actually stored. */
6963 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line);
6965 /* Copy all the intermediate outputs into the specified outputs. */
6966 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
6968 if (o[i] != TREE_VALUE (tail))
6970 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)),
6971 NULL_RTX, VOIDmode, EXPAND_NORMAL);
6972 free_temp_slots ();
6974 /* Restore the original value so that it's correct the next
6975 time we expand this function. */
6976 TREE_VALUE (tail) = o[i];
6978 /* Detect modification of read-only values.
6979 (Otherwise done by build_modify_expr.) */
6980 else
6982 tree type = TREE_TYPE (o[i]);
6983 if (TREE_READONLY (o[i])
6984 || TYPE_READONLY (type)
6985 || ((TREE_CODE (type) == RECORD_TYPE
6986 || TREE_CODE (type) == UNION_TYPE)
6987 && C_TYPE_FIELDS_READONLY (type)))
6988 readonly_warning (o[i], "modification by `asm'");
6992 /* Those MODIFY_EXPRs could do autoincrements. */
6993 emit_queue ();
6996 /* Expand a C `return' statement.
6997 RETVAL is the expression for what to return,
6998 or a null pointer for `return;' with no value. */
7000 tree
7001 c_expand_return (retval)
7002 tree retval;
7004 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl));
7006 if (TREE_THIS_VOLATILE (current_function_decl))
7007 warning ("function declared `noreturn' has a `return' statement");
7009 if (!retval)
7011 current_function_returns_null = 1;
7012 if ((warn_return_type || flag_isoc99)
7013 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
7014 pedwarn_c99 ("`return' with no value, in function returning non-void");
7016 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
7018 current_function_returns_null = 1;
7019 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
7020 pedwarn ("`return' with a value, in function returning void");
7022 else
7024 tree t = convert_for_assignment (valtype, retval, _("return"),
7025 NULL_TREE, NULL_TREE, 0);
7026 tree res = DECL_RESULT (current_function_decl);
7027 tree inner;
7029 current_function_returns_value = 1;
7030 if (t == error_mark_node)
7031 return NULL_TREE;
7033 inner = t = convert (TREE_TYPE (res), t);
7035 /* Strip any conversions, additions, and subtractions, and see if
7036 we are returning the address of a local variable. Warn if so. */
7037 while (1)
7039 switch (TREE_CODE (inner))
7041 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
7042 case PLUS_EXPR:
7043 inner = TREE_OPERAND (inner, 0);
7044 continue;
7046 case MINUS_EXPR:
7047 /* If the second operand of the MINUS_EXPR has a pointer
7048 type (or is converted from it), this may be valid, so
7049 don't give a warning. */
7051 tree op1 = TREE_OPERAND (inner, 1);
7053 while (! POINTER_TYPE_P (TREE_TYPE (op1))
7054 && (TREE_CODE (op1) == NOP_EXPR
7055 || TREE_CODE (op1) == NON_LVALUE_EXPR
7056 || TREE_CODE (op1) == CONVERT_EXPR))
7057 op1 = TREE_OPERAND (op1, 0);
7059 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7060 break;
7062 inner = TREE_OPERAND (inner, 0);
7063 continue;
7066 case ADDR_EXPR:
7067 inner = TREE_OPERAND (inner, 0);
7069 while (TREE_CODE_CLASS (TREE_CODE (inner)) == 'r')
7070 inner = TREE_OPERAND (inner, 0);
7072 if (TREE_CODE (inner) == VAR_DECL
7073 && ! DECL_EXTERNAL (inner)
7074 && ! TREE_STATIC (inner)
7075 && DECL_CONTEXT (inner) == current_function_decl)
7076 warning ("function returns address of local variable");
7077 break;
7079 default:
7080 break;
7083 break;
7086 retval = build (MODIFY_EXPR, TREE_TYPE (res), res, t);
7089 return add_stmt (build_return_stmt (retval));
7092 struct c_switch {
7093 /* The SWITCH_STMT being built. */
7094 tree switch_stmt;
7095 /* A splay-tree mapping the low element of a case range to the high
7096 element, or NULL_TREE if there is no high element. Used to
7097 determine whether or not a new case label duplicates an old case
7098 label. We need a tree, rather than simply a hash table, because
7099 of the GNU case range extension. */
7100 splay_tree cases;
7101 /* The next node on the stack. */
7102 struct c_switch *next;
7105 /* A stack of the currently active switch statements. The innermost
7106 switch statement is on the top of the stack. There is no need to
7107 mark the stack for garbage collection because it is only active
7108 during the processing of the body of a function, and we never
7109 collect at that point. */
7111 static struct c_switch *switch_stack;
7113 /* Start a C switch statement, testing expression EXP. Return the new
7114 SWITCH_STMT. */
7116 tree
7117 c_start_case (exp)
7118 tree exp;
7120 enum tree_code code;
7121 tree type, orig_type = error_mark_node;
7122 struct c_switch *cs;
7124 if (exp != error_mark_node)
7126 code = TREE_CODE (TREE_TYPE (exp));
7127 orig_type = TREE_TYPE (exp);
7129 if (! INTEGRAL_TYPE_P (orig_type)
7130 && code != ERROR_MARK)
7132 error ("switch quantity not an integer");
7133 exp = integer_zero_node;
7135 else
7137 type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
7139 if (warn_traditional && !in_system_header
7140 && (type == long_integer_type_node
7141 || type == long_unsigned_type_node))
7142 warning ("`long' switch expression not converted to `int' in ISO C");
7144 exp = default_conversion (exp);
7145 type = TREE_TYPE (exp);
7149 /* Add this new SWITCH_STMT to the stack. */
7150 cs = (struct c_switch *) xmalloc (sizeof (*cs));
7151 cs->switch_stmt = build_stmt (SWITCH_STMT, exp, NULL_TREE, orig_type);
7152 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7153 cs->next = switch_stack;
7154 switch_stack = cs;
7156 return add_stmt (switch_stack->switch_stmt);
7159 /* Process a case label. */
7161 tree
7162 do_case (low_value, high_value)
7163 tree low_value;
7164 tree high_value;
7166 tree label = NULL_TREE;
7168 if (switch_stack)
7170 label = c_add_case_label (switch_stack->cases,
7171 SWITCH_COND (switch_stack->switch_stmt),
7172 low_value, high_value);
7173 if (label == error_mark_node)
7174 label = NULL_TREE;
7176 else if (low_value)
7177 error ("case label not within a switch statement");
7178 else
7179 error ("`default' label not within a switch statement");
7181 return label;
7184 /* Finish the switch statement. */
7186 void
7187 c_finish_case ()
7189 struct c_switch *cs = switch_stack;
7191 RECHAIN_STMTS (cs->switch_stmt, SWITCH_BODY (cs->switch_stmt));
7193 /* Pop the stack. */
7194 switch_stack = switch_stack->next;
7195 splay_tree_delete (cs->cases);
7196 free (cs);