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
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
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
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). */
34 #include "coretypes.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 *,
69 static void warn_for_assignment PARAMS ((const char *, const char *,
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.) */
92 require_complete_type (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))
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. */
113 c_incomplete_type_error (value, type)
117 const char *type_code_string;
119 /* Avoid duplicate error message. */
120 if (TREE_CODE (type) == ERROR_MARK)
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)));
130 /* We must print an error message. Be clever about what it says. */
132 switch (TREE_CODE (type))
135 type_code_string = "struct";
139 type_code_string = "union";
143 type_code_string = "enum";
147 error ("invalid use of void expression");
151 if (TYPE_DOMAIN (type))
153 if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
155 error ("invalid use of flexible array member");
158 type = TREE_TYPE (type);
161 error ("invalid use of array with unspecified bounds");
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)));
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. */
182 c_type_promotes_to (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;
200 /* Return a variant of TYPE which has all the type qualifiers of LIKE
201 as well as those of TYPE. */
204 qualify_type (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
216 This is the type for the result of most arithmetic operations
217 if the operands have the given two types. */
223 enum tree_code code1;
224 enum tree_code code2;
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)
234 if (t2 == error_mark_node)
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
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);
264 return build_type_attribute_variant (build_complex_type (subtype),
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,
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;
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,
312 /* Otherwise prefer the unsigned one. */
314 if (TREE_UNSIGNED (t1))
315 return build_type_attribute_variant (t1, attributes);
317 return build_type_attribute_variant (t2, attributes);
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
332 TYPE_QUALS (pointed_to_1) |
333 TYPE_QUALS (pointed_to_2)));
334 return build_type_attribute_variant (t1, attributes);
337 t1 = build_pointer_type (common_type (TREE_TYPE (t1), TREE_TYPE (t2)));
338 return build_type_attribute_variant (t1, attributes);
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);
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);
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. */
387 declare_parm_level (1);
389 len = list_length (p1);
392 for (i = 0; i < len; i++)
393 newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
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);
407 if (TREE_VALUE (p2) == 0)
409 TREE_VALUE (n) = TREE_VALUE (p1);
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))
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);
426 pedwarn ("function types not truly compatible in ISO C");
430 if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
431 && TREE_VALUE (p2) != TREE_VALUE (p1))
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);
440 pedwarn ("function types not truly compatible in ISO C");
444 TREE_VALUE (n) = common_type (TREE_VALUE (p1), TREE_VALUE (p2));
450 t1 = build_function_type (valtype, newargs);
451 /* ... falls through ... */
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)
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)
478 /* If either type is the internal version of sizetype, return the
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
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));
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))
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))
515 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
516 if (! (attrval = (*targetm.comp_type_attributes) (t1, t2)))
519 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
522 switch (TREE_CODE (t1))
525 val = (TREE_TYPE (t1) == TREE_TYPE (t2)
526 ? 1 : comptypes (TREE_TYPE (t1), TREE_TYPE (t2)));
530 val = function_types_compatible_p (t1, t2);
535 tree d1 = TYPE_DOMAIN (t1);
536 tree d2 = TYPE_DOMAIN (t2);
537 bool d1_variable, d2_variable;
538 bool d1_zero, d2_zero;
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))))
546 /* Sizes must match unless one is missing or variable. */
547 if (d1 == 0 || d2 == 0 || d1 == d2)
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)
562 if (d1_zero && d2_zero)
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)))
573 if (flag_objc && objc_comptypes (t1, t2, 0) == 1)
578 /* The target might allow certain vector types to be compatible. */
579 val = (*targetm.vector_types_compatible) (t1, t2);
585 return attrval == 2 && val == 1 ? 2 : val;
588 /* Return 1 if TTL and TTR are pointers to types that are equivalent,
589 ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
590 to 1 or 0 depending if the check of the pointer types is meant to
591 be reflexive or not (typically, assignments are not reflexive,
592 while comparisons are reflexive).
596 comp_target_types (ttl, ttr, reflexive)
602 /* Give objc_comptypes a crack at letting these types through. */
603 if ((val = objc_comptypes (ttl, ttr, reflexive)) >= 0)
606 val = comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (ttl)),
607 TYPE_MAIN_VARIANT (TREE_TYPE (ttr)));
609 if (val == 2 && pedantic)
610 pedwarn ("types are not quite compatible");
614 /* Subroutines of `comptypes'. */
616 /* Return 1 if two function types F1 and F2 are compatible.
617 If either type specifies no argument types,
618 the other must specify a fixed number of self-promoting arg types.
619 Otherwise, if one type specifies only the number of arguments,
620 the other must specify that number of self-promoting arg types.
621 Otherwise, the argument types must match. */
624 function_types_compatible_p (f1, f2)
628 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
632 if (!(TREE_TYPE (f1) == TREE_TYPE (f2)
633 || (val = comptypes (TREE_TYPE (f1), TREE_TYPE (f2)))))
636 args1 = TYPE_ARG_TYPES (f1);
637 args2 = TYPE_ARG_TYPES (f2);
639 /* An unspecified parmlist matches any specified parmlist
640 whose argument types don't need default promotions. */
644 if (!self_promoting_args_p (args2))
646 /* If one of these types comes from a non-prototype fn definition,
647 compare that with the other type's arglist.
648 If they don't match, ask for a warning (but no error). */
649 if (TYPE_ACTUAL_ARG_TYPES (f1)
650 && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1)))
656 if (!self_promoting_args_p (args1))
658 if (TYPE_ACTUAL_ARG_TYPES (f2)
659 && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2)))
664 /* Both types have argument lists: compare them and propagate results. */
665 val1 = type_lists_compatible_p (args1, args2);
666 return val1 != 1 ? val1 : val;
669 /* Check two lists of types for compatibility,
670 returning 0 for incompatible, 1 for compatible,
671 or 2 for compatible with warning. */
674 type_lists_compatible_p (args1, args2)
677 /* 1 if no need for warning yet, 2 if warning cause has been seen. */
683 if (args1 == 0 && args2 == 0)
685 /* If one list is shorter than the other,
686 they fail to match. */
687 if (args1 == 0 || args2 == 0)
689 /* A null pointer instead of a type
690 means there is supposed to be an argument
691 but nothing is specified about what type it has.
692 So match anything that self-promotes. */
693 if (TREE_VALUE (args1) == 0)
695 if (c_type_promotes_to (TREE_VALUE (args2)) != TREE_VALUE (args2))
698 else if (TREE_VALUE (args2) == 0)
700 if (c_type_promotes_to (TREE_VALUE (args1)) != TREE_VALUE (args1))
703 else if (! (newval = comptypes (TYPE_MAIN_VARIANT (TREE_VALUE (args1)),
704 TYPE_MAIN_VARIANT (TREE_VALUE (args2)))))
706 /* Allow wait (union {union wait *u; int *i} *)
707 and wait (union wait *) to be compatible. */
708 if (TREE_CODE (TREE_VALUE (args1)) == UNION_TYPE
709 && (TYPE_NAME (TREE_VALUE (args1)) == 0
710 || TYPE_TRANSPARENT_UNION (TREE_VALUE (args1)))
711 && TREE_CODE (TYPE_SIZE (TREE_VALUE (args1))) == INTEGER_CST
712 && tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args1)),
713 TYPE_SIZE (TREE_VALUE (args2))))
716 for (memb = TYPE_FIELDS (TREE_VALUE (args1));
717 memb; memb = TREE_CHAIN (memb))
718 if (comptypes (TREE_TYPE (memb), TREE_VALUE (args2)))
723 else if (TREE_CODE (TREE_VALUE (args2)) == UNION_TYPE
724 && (TYPE_NAME (TREE_VALUE (args2)) == 0
725 || TYPE_TRANSPARENT_UNION (TREE_VALUE (args2)))
726 && TREE_CODE (TYPE_SIZE (TREE_VALUE (args2))) == INTEGER_CST
727 && tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args2)),
728 TYPE_SIZE (TREE_VALUE (args1))))
731 for (memb = TYPE_FIELDS (TREE_VALUE (args2));
732 memb; memb = TREE_CHAIN (memb))
733 if (comptypes (TREE_TYPE (memb), TREE_VALUE (args1)))
742 /* comptypes said ok, but record if it said to warn. */
746 args1 = TREE_CHAIN (args1);
747 args2 = TREE_CHAIN (args2);
751 /* Compute the size to increment a pointer by. */
754 c_size_in_bytes (type)
757 enum tree_code code = TREE_CODE (type);
759 if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
760 return size_one_node;
762 if (!COMPLETE_OR_VOID_TYPE_P (type))
764 error ("arithmetic on pointer to an incomplete type");
765 return size_one_node;
768 /* Convert in case a char is more than one unit. */
769 return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
770 size_int (TYPE_PRECISION (char_type_node)
774 /* Return either DECL or its known constant value (if it has one). */
777 decl_constant_value (decl)
780 if (/* Don't change a variable array bound or initial value to a constant
781 in a place where a variable is invalid. */
782 current_function_decl != 0
783 && ! TREE_THIS_VOLATILE (decl)
784 && TREE_READONLY (decl)
785 && DECL_INITIAL (decl) != 0
786 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK
787 /* This is invalid if initial value is not constant.
788 If it has either a function call, a memory reference,
789 or a variable, then re-evaluating it could give different results. */
790 && TREE_CONSTANT (DECL_INITIAL (decl))
791 /* Check for cases where this is sub-optimal, even though valid. */
792 && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR)
793 return DECL_INITIAL (decl);
797 /* Return either DECL or its known constant value (if it has one), but
798 return DECL if pedantic or DECL has mode BLKmode. This is for
799 bug-compatibility with the old behavior of decl_constant_value
800 (before GCC 3.0); every use of this function is a bug and it should
801 be removed before GCC 3.1. It is not appropriate to use pedantic
802 in a way that affects optimization, and BLKmode is probably not the
803 right test for avoiding misoptimizations either. */
806 decl_constant_value_for_broken_optimization (decl)
809 if (pedantic || DECL_MODE (decl) == BLKmode)
812 return decl_constant_value (decl);
816 /* Perform the default conversion of arrays and functions to pointers.
817 Return the result of converting EXP. For any other expression, just
821 default_function_array_conversion (exp)
825 tree type = TREE_TYPE (exp);
826 enum tree_code code = TREE_CODE (type);
829 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
832 Do not use STRIP_NOPS here! It will remove conversions from pointer
833 to integer and cause infinite recursion. */
835 while (TREE_CODE (exp) == NON_LVALUE_EXPR
836 || (TREE_CODE (exp) == NOP_EXPR
837 && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp)))
839 if (TREE_CODE (exp) == NON_LVALUE_EXPR)
841 exp = TREE_OPERAND (exp, 0);
844 /* Preserve the original expression code. */
845 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (exp))))
846 C_SET_EXP_ORIGINAL_CODE (exp, C_EXP_ORIGINAL_CODE (orig_exp));
848 if (code == FUNCTION_TYPE)
850 return build_unary_op (ADDR_EXPR, exp, 0);
852 if (code == ARRAY_TYPE)
855 tree restype = TREE_TYPE (type);
861 if (TREE_CODE_CLASS (TREE_CODE (exp)) == 'r' || DECL_P (exp))
863 constp = TREE_READONLY (exp);
864 volatilep = TREE_THIS_VOLATILE (exp);
867 if (TYPE_QUALS (type) || constp || volatilep)
869 = c_build_qualified_type (restype,
871 | (constp * TYPE_QUAL_CONST)
872 | (volatilep * TYPE_QUAL_VOLATILE));
874 if (TREE_CODE (exp) == INDIRECT_REF)
875 return convert (TYPE_POINTER_TO (restype),
876 TREE_OPERAND (exp, 0));
878 if (TREE_CODE (exp) == COMPOUND_EXPR)
880 tree op1 = default_conversion (TREE_OPERAND (exp, 1));
881 return build (COMPOUND_EXPR, TREE_TYPE (op1),
882 TREE_OPERAND (exp, 0), op1);
885 lvalue_array_p = !not_lvalue && lvalue_p (exp);
886 if (!flag_isoc99 && !lvalue_array_p)
888 /* Before C99, non-lvalue arrays do not decay to pointers.
889 Normally, using such an array would be invalid; but it can
890 be used correctly inside sizeof or as a statement expression.
891 Thus, do not give an error here; an error will result later. */
895 ptrtype = build_pointer_type (restype);
897 if (TREE_CODE (exp) == VAR_DECL)
899 /* ??? This is not really quite correct
900 in that the type of the operand of ADDR_EXPR
901 is not the target type of the type of the ADDR_EXPR itself.
902 Question is, can this lossage be avoided? */
903 adr = build1 (ADDR_EXPR, ptrtype, exp);
904 if (!c_mark_addressable (exp))
905 return error_mark_node;
906 TREE_CONSTANT (adr) = staticp (exp);
907 TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */
910 /* This way is better for a COMPONENT_REF since it can
911 simplify the offset for a component. */
912 adr = build_unary_op (ADDR_EXPR, exp, 1);
913 return convert (ptrtype, adr);
918 /* Perform default promotions for C data used in expressions.
919 Arrays and functions are converted to pointers;
920 enumeral types or short or char, to int.
921 In addition, manifest constants symbols are replaced by their values. */
924 default_conversion (exp)
928 tree type = TREE_TYPE (exp);
929 enum tree_code code = TREE_CODE (type);
931 if (code == FUNCTION_TYPE || code == ARRAY_TYPE)
932 return default_function_array_conversion (exp);
934 /* Constants can be used directly unless they're not loadable. */
935 if (TREE_CODE (exp) == CONST_DECL)
936 exp = DECL_INITIAL (exp);
938 /* Replace a nonvolatile const static variable with its value unless
939 it is an array, in which case we must be sure that taking the
940 address of the array produces consistent results. */
941 else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE)
943 exp = decl_constant_value_for_broken_optimization (exp);
944 type = TREE_TYPE (exp);
947 /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as
950 Do not use STRIP_NOPS here! It will remove conversions from pointer
951 to integer and cause infinite recursion. */
953 while (TREE_CODE (exp) == NON_LVALUE_EXPR
954 || (TREE_CODE (exp) == NOP_EXPR
955 && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp)))
956 exp = TREE_OPERAND (exp, 0);
958 /* Preserve the original expression code. */
959 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (exp))))
960 C_SET_EXP_ORIGINAL_CODE (exp, C_EXP_ORIGINAL_CODE (orig_exp));
962 /* Normally convert enums to int,
963 but convert wide enums to something wider. */
964 if (code == ENUMERAL_TYPE)
966 type = c_common_type_for_size (MAX (TYPE_PRECISION (type),
967 TYPE_PRECISION (integer_type_node)),
968 ((TYPE_PRECISION (type)
969 >= TYPE_PRECISION (integer_type_node))
970 && TREE_UNSIGNED (type)));
972 return convert (type, exp);
975 if (TREE_CODE (exp) == COMPONENT_REF
976 && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1))
977 /* If it's thinner than an int, promote it like a
978 c_promoting_integer_type_p, otherwise leave it alone. */
979 && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)),
980 TYPE_PRECISION (integer_type_node)))
981 return convert (integer_type_node, exp);
983 if (c_promoting_integer_type_p (type))
985 /* Preserve unsignedness if not really getting any wider. */
986 if (TREE_UNSIGNED (type)
987 && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))
988 return convert (unsigned_type_node, exp);
990 return convert (integer_type_node, exp);
993 if (code == VOID_TYPE)
995 error ("void value not ignored as it ought to be");
996 return error_mark_node;
1001 /* Look up COMPONENT in a structure or union DECL.
1003 If the component name is not found, returns NULL_TREE. Otherwise,
1004 the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL
1005 stepping down the chain to the component, which is in the last
1006 TREE_VALUE of the list. Normally the list is of length one, but if
1007 the component is embedded within (nested) anonymous structures or
1008 unions, the list steps down the chain to the component. */
1011 lookup_field (decl, component)
1012 tree decl, component;
1014 tree type = TREE_TYPE (decl);
1017 /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers
1018 to the field elements. Use a binary search on this array to quickly
1019 find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC
1020 will always be set for structures which have many elements. */
1022 if (TYPE_LANG_SPECIFIC (type))
1025 tree *field_array = &TYPE_LANG_SPECIFIC (type)->elts[0];
1027 field = TYPE_FIELDS (type);
1029 top = TYPE_LANG_SPECIFIC (type)->len;
1030 while (top - bot > 1)
1032 half = (top - bot + 1) >> 1;
1033 field = field_array[bot+half];
1035 if (DECL_NAME (field) == NULL_TREE)
1037 /* Step through all anon unions in linear fashion. */
1038 while (DECL_NAME (field_array[bot]) == NULL_TREE)
1040 field = field_array[bot++];
1041 if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1042 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)
1044 tree anon = lookup_field (field, component);
1047 return tree_cons (NULL_TREE, field, anon);
1051 /* Entire record is only anon unions. */
1055 /* Restart the binary search, with new lower bound. */
1059 if (DECL_NAME (field) == component)
1061 if (DECL_NAME (field) < component)
1067 if (DECL_NAME (field_array[bot]) == component)
1068 field = field_array[bot];
1069 else if (DECL_NAME (field) != component)
1074 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1076 if (DECL_NAME (field) == NULL_TREE
1077 && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE
1078 || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE))
1080 tree anon = lookup_field (field, component);
1083 return tree_cons (NULL_TREE, field, anon);
1086 if (DECL_NAME (field) == component)
1090 if (field == NULL_TREE)
1094 return tree_cons (NULL_TREE, field, NULL_TREE);
1097 /* Make an expression to refer to the COMPONENT field of
1098 structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */
1101 build_component_ref (datum, component)
1102 tree datum, component;
1104 tree type = TREE_TYPE (datum);
1105 enum tree_code code = TREE_CODE (type);
1109 /* If DATUM is a COMPOUND_EXPR, move our reference inside it.
1110 If pedantic ensure that the arguments are not lvalues; otherwise,
1111 if the component is an array, it would wrongly decay to a pointer in
1113 We cannot do this with a COND_EXPR, because in a conditional expression
1114 the default promotions are applied to both sides, and this would yield
1115 the wrong type of the result; for example, if the components have
1117 switch (TREE_CODE (datum))
1121 tree value = build_component_ref (TREE_OPERAND (datum, 1), component);
1122 return build (COMPOUND_EXPR, TREE_TYPE (value),
1123 TREE_OPERAND (datum, 0), pedantic_non_lvalue (value));
1129 /* See if there is a field or component with name COMPONENT. */
1131 if (code == RECORD_TYPE || code == UNION_TYPE)
1133 if (!COMPLETE_TYPE_P (type))
1135 c_incomplete_type_error (NULL_TREE, type);
1136 return error_mark_node;
1139 field = lookup_field (datum, component);
1143 error ("%s has no member named `%s'",
1144 code == RECORD_TYPE ? "structure" : "union",
1145 IDENTIFIER_POINTER (component));
1146 return error_mark_node;
1149 /* Chain the COMPONENT_REFs if necessary down to the FIELD.
1150 This might be better solved in future the way the C++ front
1151 end does it - by giving the anonymous entities each a
1152 separate name and type, and then have build_component_ref
1153 recursively call itself. We can't do that here. */
1154 for (; field; field = TREE_CHAIN (field))
1156 tree subdatum = TREE_VALUE (field);
1158 if (TREE_TYPE (subdatum) == error_mark_node)
1159 return error_mark_node;
1161 ref = build (COMPONENT_REF, TREE_TYPE (subdatum), datum, subdatum);
1162 if (TREE_READONLY (datum) || TREE_READONLY (subdatum))
1163 TREE_READONLY (ref) = 1;
1164 if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum))
1165 TREE_THIS_VOLATILE (ref) = 1;
1167 if (TREE_DEPRECATED (subdatum))
1168 warn_deprecated_use (subdatum);
1175 else if (code != ERROR_MARK)
1176 error ("request for member `%s' in something not a structure or union",
1177 IDENTIFIER_POINTER (component));
1179 return error_mark_node;
1182 /* Given an expression PTR for a pointer, return an expression
1183 for the value pointed to.
1184 ERRORSTRING is the name of the operator to appear in error messages. */
1187 build_indirect_ref (ptr, errorstring)
1189 const char *errorstring;
1191 tree pointer = default_conversion (ptr);
1192 tree type = TREE_TYPE (pointer);
1194 if (TREE_CODE (type) == POINTER_TYPE)
1196 if (TREE_CODE (pointer) == ADDR_EXPR
1197 && (TREE_TYPE (TREE_OPERAND (pointer, 0))
1198 == TREE_TYPE (type)))
1199 return TREE_OPERAND (pointer, 0);
1202 tree t = TREE_TYPE (type);
1203 tree ref = build1 (INDIRECT_REF, TYPE_MAIN_VARIANT (t), pointer);
1205 if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE)
1207 error ("dereferencing pointer to incomplete type");
1208 return error_mark_node;
1210 if (VOID_TYPE_P (t) && skip_evaluation == 0)
1211 warning ("dereferencing `void *' pointer");
1213 /* We *must* set TREE_READONLY when dereferencing a pointer to const,
1214 so that we get the proper error message if the result is used
1215 to assign to. Also, &* is supposed to be a no-op.
1216 And ANSI C seems to specify that the type of the result
1217 should be the const type. */
1218 /* A de-reference of a pointer to const is not a const. It is valid
1219 to change it via some other pointer. */
1220 TREE_READONLY (ref) = TYPE_READONLY (t);
1221 TREE_SIDE_EFFECTS (ref)
1222 = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer);
1223 TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t);
1227 else if (TREE_CODE (pointer) != ERROR_MARK)
1228 error ("invalid type argument of `%s'", errorstring);
1229 return error_mark_node;
1232 /* This handles expressions of the form "a[i]", which denotes
1235 This is logically equivalent in C to *(a+i), but we may do it differently.
1236 If A is a variable or a member, we generate a primitive ARRAY_REF.
1237 This avoids forcing the array out of registers, and can work on
1238 arrays that are not lvalues (for example, members of structures returned
1242 build_array_ref (array, index)
1247 error ("subscript missing in array reference");
1248 return error_mark_node;
1251 if (TREE_TYPE (array) == error_mark_node
1252 || TREE_TYPE (index) == error_mark_node)
1253 return error_mark_node;
1255 if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE
1256 && TREE_CODE (array) != INDIRECT_REF)
1260 /* Subscripting with type char is likely to lose
1261 on a machine where chars are signed.
1262 So warn on any machine, but optionally.
1263 Don't warn for unsigned char since that type is safe.
1264 Don't warn for signed char because anyone who uses that
1265 must have done so deliberately. */
1266 if (warn_char_subscripts
1267 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node)
1268 warning ("array subscript has type `char'");
1270 /* Apply default promotions *after* noticing character types. */
1271 index = default_conversion (index);
1273 /* Require integer *after* promotion, for sake of enums. */
1274 if (TREE_CODE (TREE_TYPE (index)) != INTEGER_TYPE)
1276 error ("array subscript is not an integer");
1277 return error_mark_node;
1280 /* An array that is indexed by a non-constant
1281 cannot be stored in a register; we must be able to do
1282 address arithmetic on its address.
1283 Likewise an array of elements of variable size. */
1284 if (TREE_CODE (index) != INTEGER_CST
1285 || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array)))
1286 && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST))
1288 if (!c_mark_addressable (array))
1289 return error_mark_node;
1291 /* An array that is indexed by a constant value which is not within
1292 the array bounds cannot be stored in a register either; because we
1293 would get a crash in store_bit_field/extract_bit_field when trying
1294 to access a non-existent part of the register. */
1295 if (TREE_CODE (index) == INTEGER_CST
1296 && TYPE_VALUES (TREE_TYPE (array))
1297 && ! int_fits_type_p (index, TYPE_VALUES (TREE_TYPE (array))))
1299 if (!c_mark_addressable (array))
1300 return error_mark_node;
1306 while (TREE_CODE (foo) == COMPONENT_REF)
1307 foo = TREE_OPERAND (foo, 0);
1308 if (TREE_CODE (foo) == VAR_DECL && DECL_REGISTER (foo))
1309 pedwarn ("ISO C forbids subscripting `register' array");
1310 else if (! flag_isoc99 && ! lvalue_p (foo))
1311 pedwarn ("ISO C90 forbids subscripting non-lvalue array");
1314 type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (array)));
1315 rval = build (ARRAY_REF, type, array, index);
1316 /* Array ref is const/volatile if the array elements are
1317 or if the array is. */
1318 TREE_READONLY (rval)
1319 |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array)))
1320 | TREE_READONLY (array));
1321 TREE_SIDE_EFFECTS (rval)
1322 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
1323 | TREE_SIDE_EFFECTS (array));
1324 TREE_THIS_VOLATILE (rval)
1325 |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array)))
1326 /* This was added by rms on 16 Nov 91.
1327 It fixes vol struct foo *a; a->elts[1]
1328 in an inline function.
1329 Hope it doesn't break something else. */
1330 | TREE_THIS_VOLATILE (array));
1331 return require_complete_type (fold (rval));
1335 tree ar = default_conversion (array);
1336 tree ind = default_conversion (index);
1338 /* Do the same warning check as above, but only on the part that's
1339 syntactically the index and only if it is also semantically
1341 if (warn_char_subscripts
1342 && TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE
1343 && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node)
1344 warning ("subscript has type `char'");
1346 /* Put the integer in IND to simplify error checking. */
1347 if (TREE_CODE (TREE_TYPE (ar)) == INTEGER_TYPE)
1354 if (ar == error_mark_node)
1357 if (TREE_CODE (TREE_TYPE (ar)) != POINTER_TYPE
1358 || TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) == FUNCTION_TYPE)
1360 error ("subscripted value is neither array nor pointer");
1361 return error_mark_node;
1363 if (TREE_CODE (TREE_TYPE (ind)) != INTEGER_TYPE)
1365 error ("array subscript is not an integer");
1366 return error_mark_node;
1369 return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, ind, 0),
1374 /* Build an external reference to identifier ID. FUN indicates
1375 whether this will be used for a function call. */
1377 build_external_ref (id, fun)
1382 tree decl = lookup_name (id);
1383 tree objc_ivar = lookup_objc_ivar (id);
1385 if (decl && TREE_DEPRECATED (decl))
1386 warn_deprecated_use (decl);
1388 if (!decl || decl == error_mark_node || C_DECL_ANTICIPATED (decl))
1394 if (!decl || decl == error_mark_node)
1395 /* Ordinary implicit function declaration. */
1396 ref = implicitly_declare (id);
1399 /* Implicit declaration of built-in function. Don't
1400 change the built-in declaration, but don't let this
1401 go by silently, either. */
1402 implicit_decl_warning (id);
1404 /* only issue this warning once */
1405 C_DECL_ANTICIPATED (decl) = 0;
1411 /* Reference to undeclared variable, including reference to
1412 builtin outside of function-call context. */
1413 if (current_function_decl == 0)
1414 error ("`%s' undeclared here (not in a function)",
1415 IDENTIFIER_POINTER (id));
1418 if (IDENTIFIER_GLOBAL_VALUE (id) != error_mark_node
1419 || IDENTIFIER_ERROR_LOCUS (id) != current_function_decl)
1421 error ("`%s' undeclared (first use in this function)",
1422 IDENTIFIER_POINTER (id));
1424 if (! undeclared_variable_notice)
1426 error ("(Each undeclared identifier is reported only once");
1427 error ("for each function it appears in.)");
1428 undeclared_variable_notice = 1;
1431 IDENTIFIER_GLOBAL_VALUE (id) = error_mark_node;
1432 IDENTIFIER_ERROR_LOCUS (id) = current_function_decl;
1434 return error_mark_node;
1439 /* Properly declared variable or function reference. */
1442 else if (decl != objc_ivar && IDENTIFIER_LOCAL_VALUE (id))
1444 warning ("local declaration of `%s' hides instance variable",
1445 IDENTIFIER_POINTER (id));
1452 if (TREE_TYPE (ref) == error_mark_node)
1453 return error_mark_node;
1455 if (!skip_evaluation)
1456 assemble_external (ref);
1457 TREE_USED (ref) = 1;
1459 if (TREE_CODE (ref) == CONST_DECL)
1461 ref = DECL_INITIAL (ref);
1462 TREE_CONSTANT (ref) = 1;
1468 /* Build a function call to function FUNCTION with parameters PARAMS.
1469 PARAMS is a list--a chain of TREE_LIST nodes--in which the
1470 TREE_VALUE of each node is a parameter-expression.
1471 FUNCTION's data type may be a function type or a pointer-to-function. */
1474 build_function_call (function, params)
1475 tree function, params;
1477 tree fntype, fundecl = 0;
1478 tree coerced_params;
1479 tree name = NULL_TREE, result;
1481 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1482 STRIP_TYPE_NOPS (function);
1484 /* Convert anything with function type to a pointer-to-function. */
1485 if (TREE_CODE (function) == FUNCTION_DECL)
1487 name = DECL_NAME (function);
1489 /* Differs from default_conversion by not setting TREE_ADDRESSABLE
1490 (because calling an inline function does not mean the function
1491 needs to be separately compiled). */
1492 fntype = build_type_variant (TREE_TYPE (function),
1493 TREE_READONLY (function),
1494 TREE_THIS_VOLATILE (function));
1496 function = build1 (ADDR_EXPR, build_pointer_type (fntype), function);
1499 function = default_conversion (function);
1501 fntype = TREE_TYPE (function);
1503 if (TREE_CODE (fntype) == ERROR_MARK)
1504 return error_mark_node;
1506 if (!(TREE_CODE (fntype) == POINTER_TYPE
1507 && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE))
1509 error ("called object is not a function");
1510 return error_mark_node;
1513 if (fundecl && TREE_THIS_VOLATILE (fundecl))
1514 current_function_returns_abnormally = 1;
1516 /* fntype now gets the type of function pointed to. */
1517 fntype = TREE_TYPE (fntype);
1519 /* Convert the parameters to the types declared in the
1520 function prototype, or apply default promotions. */
1523 = convert_arguments (TYPE_ARG_TYPES (fntype), params, name, fundecl);
1525 /* Check that the arguments to the function are valid. */
1527 check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params);
1529 /* Recognize certain built-in functions so we can make tree-codes
1530 other than CALL_EXPR. We do this when it enables fold-const.c
1531 to do something useful. */
1533 if (TREE_CODE (function) == ADDR_EXPR
1534 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL
1535 && DECL_BUILT_IN (TREE_OPERAND (function, 0)))
1537 result = expand_tree_builtin (TREE_OPERAND (function, 0),
1538 params, coerced_params);
1543 result = build (CALL_EXPR, TREE_TYPE (fntype),
1544 function, coerced_params, NULL_TREE);
1545 TREE_SIDE_EFFECTS (result) = 1;
1546 result = fold (result);
1548 if (VOID_TYPE_P (TREE_TYPE (result)))
1550 return require_complete_type (result);
1553 /* Convert the argument expressions in the list VALUES
1554 to the types in the list TYPELIST. The result is a list of converted
1555 argument expressions.
1557 If TYPELIST is exhausted, or when an element has NULL as its type,
1558 perform the default conversions.
1560 PARMLIST is the chain of parm decls for the function being called.
1561 It may be 0, if that info is not available.
1562 It is used only for generating error messages.
1564 NAME is an IDENTIFIER_NODE or 0. It is used only for error messages.
1566 This is also where warnings about wrong number of args are generated.
1568 Both VALUES and the returned value are chains of TREE_LIST nodes
1569 with the elements of the list in the TREE_VALUE slots of those nodes. */
1572 convert_arguments (typelist, values, name, fundecl)
1573 tree typelist, values, name, fundecl;
1575 tree typetail, valtail;
1579 /* Scan the given expressions and types, producing individual
1580 converted arguments and pushing them on RESULT in reverse order. */
1582 for (valtail = values, typetail = typelist, parmnum = 0;
1584 valtail = TREE_CHAIN (valtail), parmnum++)
1586 tree type = typetail ? TREE_VALUE (typetail) : 0;
1587 tree val = TREE_VALUE (valtail);
1589 if (type == void_type_node)
1592 error ("too many arguments to function `%s'",
1593 IDENTIFIER_POINTER (name));
1595 error ("too many arguments to function");
1599 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
1600 /* Do not use STRIP_NOPS here! We do not want an enumerator with value 0
1601 to convert automatically to a pointer. */
1602 if (TREE_CODE (val) == NON_LVALUE_EXPR)
1603 val = TREE_OPERAND (val, 0);
1605 val = default_function_array_conversion (val);
1607 val = require_complete_type (val);
1611 /* Formal parm type is specified by a function prototype. */
1614 if (!COMPLETE_TYPE_P (type))
1616 error ("type of formal parameter %d is incomplete", parmnum + 1);
1621 /* Optionally warn about conversions that
1622 differ from the default conversions. */
1623 if (warn_conversion || warn_traditional)
1625 int formal_prec = TYPE_PRECISION (type);
1627 if (INTEGRAL_TYPE_P (type)
1628 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
1629 warn_for_assignment ("%s as integer rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1630 if (INTEGRAL_TYPE_P (type)
1631 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
1632 warn_for_assignment ("%s as integer rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1633 else if (TREE_CODE (type) == COMPLEX_TYPE
1634 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
1635 warn_for_assignment ("%s as complex rather than floating due to prototype", (char *) 0, name, parmnum + 1);
1636 else if (TREE_CODE (type) == REAL_TYPE
1637 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
1638 warn_for_assignment ("%s as floating rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1639 else if (TREE_CODE (type) == COMPLEX_TYPE
1640 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
1641 warn_for_assignment ("%s as complex rather than integer due to prototype", (char *) 0, name, parmnum + 1);
1642 else if (TREE_CODE (type) == REAL_TYPE
1643 && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE)
1644 warn_for_assignment ("%s as floating rather than complex due to prototype", (char *) 0, name, parmnum + 1);
1645 /* ??? At some point, messages should be written about
1646 conversions between complex types, but that's too messy
1648 else if (TREE_CODE (type) == REAL_TYPE
1649 && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE)
1651 /* Warn if any argument is passed as `float',
1652 since without a prototype it would be `double'. */
1653 if (formal_prec == TYPE_PRECISION (float_type_node))
1654 warn_for_assignment ("%s as `float' rather than `double' due to prototype", (char *) 0, name, parmnum + 1);
1656 /* Detect integer changing in width or signedness.
1657 These warnings are only activated with
1658 -Wconversion, not with -Wtraditional. */
1659 else if (warn_conversion && INTEGRAL_TYPE_P (type)
1660 && INTEGRAL_TYPE_P (TREE_TYPE (val)))
1662 tree would_have_been = default_conversion (val);
1663 tree type1 = TREE_TYPE (would_have_been);
1665 if (TREE_CODE (type) == ENUMERAL_TYPE
1666 && (TYPE_MAIN_VARIANT (type)
1667 == TYPE_MAIN_VARIANT (TREE_TYPE (val))))
1668 /* No warning if function asks for enum
1669 and the actual arg is that enum type. */
1671 else if (formal_prec != TYPE_PRECISION (type1))
1672 warn_for_assignment ("%s with different width due to prototype", (char *) 0, name, parmnum + 1);
1673 else if (TREE_UNSIGNED (type) == TREE_UNSIGNED (type1))
1675 /* Don't complain if the formal parameter type
1676 is an enum, because we can't tell now whether
1677 the value was an enum--even the same enum. */
1678 else if (TREE_CODE (type) == ENUMERAL_TYPE)
1680 else if (TREE_CODE (val) == INTEGER_CST
1681 && int_fits_type_p (val, type))
1682 /* Change in signedness doesn't matter
1683 if a constant value is unaffected. */
1685 /* Likewise for a constant in a NOP_EXPR. */
1686 else if (TREE_CODE (val) == NOP_EXPR
1687 && TREE_CODE (TREE_OPERAND (val, 0)) == INTEGER_CST
1688 && int_fits_type_p (TREE_OPERAND (val, 0), type))
1690 #if 0 /* We never get such tree structure here. */
1691 else if (TREE_CODE (TREE_TYPE (val)) == ENUMERAL_TYPE
1692 && int_fits_type_p (TYPE_MIN_VALUE (TREE_TYPE (val)), type)
1693 && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (val)), type))
1694 /* Change in signedness doesn't matter
1695 if an enum value is unaffected. */
1698 /* If the value is extended from a narrower
1699 unsigned type, it doesn't matter whether we
1700 pass it as signed or unsigned; the value
1701 certainly is the same either way. */
1702 else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type)
1703 && TREE_UNSIGNED (TREE_TYPE (val)))
1705 else if (TREE_UNSIGNED (type))
1706 warn_for_assignment ("%s as unsigned due to prototype", (char *) 0, name, parmnum + 1);
1708 warn_for_assignment ("%s as signed due to prototype", (char *) 0, name, parmnum + 1);
1712 parmval = convert_for_assignment (type, val,
1713 (char *) 0, /* arg passing */
1714 fundecl, name, parmnum + 1);
1716 if (PROMOTE_PROTOTYPES
1717 && INTEGRAL_TYPE_P (type)
1718 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
1719 parmval = default_conversion (parmval);
1721 result = tree_cons (NULL_TREE, parmval, result);
1723 else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE
1724 && (TYPE_PRECISION (TREE_TYPE (val))
1725 < TYPE_PRECISION (double_type_node)))
1726 /* Convert `float' to `double'. */
1727 result = tree_cons (NULL_TREE, convert (double_type_node, val), result);
1729 /* Convert `short' and `char' to full-size `int'. */
1730 result = tree_cons (NULL_TREE, default_conversion (val), result);
1733 typetail = TREE_CHAIN (typetail);
1736 if (typetail != 0 && TREE_VALUE (typetail) != void_type_node)
1739 error ("too few arguments to function `%s'",
1740 IDENTIFIER_POINTER (name));
1742 error ("too few arguments to function");
1745 return nreverse (result);
1748 /* This is the entry point used by the parser
1749 for binary operators in the input.
1750 In addition to constructing the expression,
1751 we check for operands that were written with other binary operators
1752 in a way that is likely to confuse the user. */
1755 parser_build_binary_op (code, arg1, arg2)
1756 enum tree_code code;
1759 tree result = build_binary_op (code, arg1, arg2, 1);
1762 char class1 = TREE_CODE_CLASS (TREE_CODE (arg1));
1763 char class2 = TREE_CODE_CLASS (TREE_CODE (arg2));
1764 enum tree_code code1 = ERROR_MARK;
1765 enum tree_code code2 = ERROR_MARK;
1767 if (TREE_CODE (result) == ERROR_MARK)
1768 return error_mark_node;
1770 if (IS_EXPR_CODE_CLASS (class1))
1771 code1 = C_EXP_ORIGINAL_CODE (arg1);
1772 if (IS_EXPR_CODE_CLASS (class2))
1773 code2 = C_EXP_ORIGINAL_CODE (arg2);
1775 /* Check for cases such as x+y<<z which users are likely
1776 to misinterpret. If parens are used, C_EXP_ORIGINAL_CODE
1777 is cleared to prevent these warnings. */
1778 if (warn_parentheses)
1780 if (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
1782 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
1783 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1784 warning ("suggest parentheses around + or - inside shift");
1787 if (code == TRUTH_ORIF_EXPR)
1789 if (code1 == TRUTH_ANDIF_EXPR
1790 || code2 == TRUTH_ANDIF_EXPR)
1791 warning ("suggest parentheses around && within ||");
1794 if (code == BIT_IOR_EXPR)
1796 if (code1 == BIT_AND_EXPR || code1 == BIT_XOR_EXPR
1797 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
1798 || code2 == BIT_AND_EXPR || code2 == BIT_XOR_EXPR
1799 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1800 warning ("suggest parentheses around arithmetic in operand of |");
1801 /* Check cases like x|y==z */
1802 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')
1803 warning ("suggest parentheses around comparison in operand of |");
1806 if (code == BIT_XOR_EXPR)
1808 if (code1 == BIT_AND_EXPR
1809 || code1 == PLUS_EXPR || code1 == MINUS_EXPR
1810 || code2 == BIT_AND_EXPR
1811 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1812 warning ("suggest parentheses around arithmetic in operand of ^");
1813 /* Check cases like x^y==z */
1814 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')
1815 warning ("suggest parentheses around comparison in operand of ^");
1818 if (code == BIT_AND_EXPR)
1820 if (code1 == PLUS_EXPR || code1 == MINUS_EXPR
1821 || code2 == PLUS_EXPR || code2 == MINUS_EXPR)
1822 warning ("suggest parentheses around + or - in operand of &");
1823 /* Check cases like x&y==z */
1824 if (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<')
1825 warning ("suggest parentheses around comparison in operand of &");
1829 /* Similarly, check for cases like 1<=i<=10 that are probably errors. */
1830 if (TREE_CODE_CLASS (code) == '<' && extra_warnings
1831 && (TREE_CODE_CLASS (code1) == '<' || TREE_CODE_CLASS (code2) == '<'))
1832 warning ("comparisons like X<=Y<=Z do not have their mathematical meaning");
1834 unsigned_conversion_warning (result, arg1);
1835 unsigned_conversion_warning (result, arg2);
1836 overflow_warning (result);
1838 class = TREE_CODE_CLASS (TREE_CODE (result));
1840 /* Record the code that was specified in the source,
1841 for the sake of warnings about confusing nesting. */
1842 if (IS_EXPR_CODE_CLASS (class))
1843 C_SET_EXP_ORIGINAL_CODE (result, code);
1846 int flag = TREE_CONSTANT (result);
1847 /* We used to use NOP_EXPR rather than NON_LVALUE_EXPR
1848 so that convert_for_assignment wouldn't strip it.
1849 That way, we got warnings for things like p = (1 - 1).
1850 But it turns out we should not get those warnings. */
1851 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
1852 C_SET_EXP_ORIGINAL_CODE (result, code);
1853 TREE_CONSTANT (result) = flag;
1859 /* Build a binary-operation expression without default conversions.
1860 CODE is the kind of expression to build.
1861 This function differs from `build' in several ways:
1862 the data type of the result is computed and recorded in it,
1863 warnings are generated if arg data types are invalid,
1864 special handling for addition and subtraction of pointers is known,
1865 and some optimization is done (operations on narrow ints
1866 are done in the narrower type when that gives the same result).
1867 Constant folding is also done before the result is returned.
1869 Note that the operands will never have enumeral types, or function
1870 or array types, because either they will have the default conversions
1871 performed or they have both just been converted to some other type in which
1872 the arithmetic is to be done. */
1875 build_binary_op (code, orig_op0, orig_op1, convert_p)
1876 enum tree_code code;
1877 tree orig_op0, orig_op1;
1881 enum tree_code code0, code1;
1884 /* Expression code to give to the expression when it is built.
1885 Normally this is CODE, which is what the caller asked for,
1886 but in some special cases we change it. */
1887 enum tree_code resultcode = code;
1889 /* Data type in which the computation is to be performed.
1890 In the simplest cases this is the common type of the arguments. */
1891 tree result_type = NULL;
1893 /* Nonzero means operands have already been type-converted
1894 in whatever way is necessary.
1895 Zero means they need to be converted to RESULT_TYPE. */
1898 /* Nonzero means create the expression with this type, rather than
1900 tree build_type = 0;
1902 /* Nonzero means after finally constructing the expression
1903 convert it to this type. */
1904 tree final_type = 0;
1906 /* Nonzero if this is an operation like MIN or MAX which can
1907 safely be computed in short if both args are promoted shorts.
1908 Also implies COMMON.
1909 -1 indicates a bitwise operation; this makes a difference
1910 in the exact conditions for when it is safe to do the operation
1911 in a narrower mode. */
1914 /* Nonzero if this is a comparison operation;
1915 if both args are promoted shorts, compare the original shorts.
1916 Also implies COMMON. */
1917 int short_compare = 0;
1919 /* Nonzero if this is a right-shift operation, which can be computed on the
1920 original short and then promoted if the operand is a promoted short. */
1921 int short_shift = 0;
1923 /* Nonzero means set RESULT_TYPE to the common type of the args. */
1928 op0 = default_conversion (orig_op0);
1929 op1 = default_conversion (orig_op1);
1937 type0 = TREE_TYPE (op0);
1938 type1 = TREE_TYPE (op1);
1940 /* The expression codes of the data types of the arguments tell us
1941 whether the arguments are integers, floating, pointers, etc. */
1942 code0 = TREE_CODE (type0);
1943 code1 = TREE_CODE (type1);
1945 /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */
1946 STRIP_TYPE_NOPS (op0);
1947 STRIP_TYPE_NOPS (op1);
1949 /* If an error was already reported for one of the arguments,
1950 avoid reporting another error. */
1952 if (code0 == ERROR_MARK || code1 == ERROR_MARK)
1953 return error_mark_node;
1958 /* Handle the pointer + int case. */
1959 if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
1960 return pointer_int_sum (PLUS_EXPR, op0, op1);
1961 else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE)
1962 return pointer_int_sum (PLUS_EXPR, op1, op0);
1968 /* Subtraction of two similar pointers.
1969 We must subtract them as integers, then divide by object size. */
1970 if (code0 == POINTER_TYPE && code1 == POINTER_TYPE
1971 && comp_target_types (type0, type1, 1))
1972 return pointer_diff (op0, op1);
1973 /* Handle pointer minus int. Just like pointer plus int. */
1974 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
1975 return pointer_int_sum (MINUS_EXPR, op0, op1);
1984 case TRUNC_DIV_EXPR:
1986 case FLOOR_DIV_EXPR:
1987 case ROUND_DIV_EXPR:
1988 case EXACT_DIV_EXPR:
1989 /* Floating point division by zero is a legitimate way to obtain
1990 infinities and NaNs. */
1991 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1))
1992 warning ("division by zero");
1994 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
1995 || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
1996 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
1997 || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
1999 if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
2000 resultcode = RDIV_EXPR;
2002 /* Although it would be tempting to shorten always here, that
2003 loses on some targets, since the modulo instruction is
2004 undefined if the quotient can't be represented in the
2005 computation mode. We shorten only if unsigned or if
2006 dividing by something we know != -1. */
2007 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0))
2008 || (TREE_CODE (op1) == INTEGER_CST
2009 && ! integer_all_onesp (op1)));
2015 case BIT_ANDTC_EXPR:
2018 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2020 else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE)
2024 case TRUNC_MOD_EXPR:
2025 case FLOOR_MOD_EXPR:
2026 if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1))
2027 warning ("division by zero");
2029 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2031 /* Although it would be tempting to shorten always here, that loses
2032 on some targets, since the modulo instruction is undefined if the
2033 quotient can't be represented in the computation mode. We shorten
2034 only if unsigned or if dividing by something we know != -1. */
2035 shorten = (TREE_UNSIGNED (TREE_TYPE (orig_op0))
2036 || (TREE_CODE (op1) == INTEGER_CST
2037 && ! integer_all_onesp (op1)));
2042 case TRUTH_ANDIF_EXPR:
2043 case TRUTH_ORIF_EXPR:
2044 case TRUTH_AND_EXPR:
2046 case TRUTH_XOR_EXPR:
2047 if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE
2048 || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
2049 && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE
2050 || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
2052 /* Result of these operations is always an int,
2053 but that does not mean the operands should be
2054 converted to ints! */
2055 result_type = integer_type_node;
2056 op0 = c_common_truthvalue_conversion (op0);
2057 op1 = c_common_truthvalue_conversion (op1);
2062 /* Shift operations: result has same type as first operand;
2063 always convert second operand to int.
2064 Also set SHORT_SHIFT if shifting rightward. */
2067 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2069 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
2071 if (tree_int_cst_sgn (op1) < 0)
2072 warning ("right shift count is negative");
2075 if (! integer_zerop (op1))
2078 if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2079 warning ("right shift count >= width of type");
2083 /* Use the type of the value to be shifted. */
2084 result_type = type0;
2085 /* Convert the shift-count to an integer, regardless of size
2086 of value being shifted. */
2087 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2088 op1 = convert (integer_type_node, op1);
2089 /* Avoid converting op1 to result_type later. */
2095 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2097 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
2099 if (tree_int_cst_sgn (op1) < 0)
2100 warning ("left shift count is negative");
2102 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2103 warning ("left shift count >= width of type");
2106 /* Use the type of the value to be shifted. */
2107 result_type = type0;
2108 /* Convert the shift-count to an integer, regardless of size
2109 of value being shifted. */
2110 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2111 op1 = convert (integer_type_node, op1);
2112 /* Avoid converting op1 to result_type later. */
2119 if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)
2121 if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0)
2123 if (tree_int_cst_sgn (op1) < 0)
2124 warning ("shift count is negative");
2125 else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0)
2126 warning ("shift count >= width of type");
2129 /* Use the type of the value to be shifted. */
2130 result_type = type0;
2131 /* Convert the shift-count to an integer, regardless of size
2132 of value being shifted. */
2133 if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node)
2134 op1 = convert (integer_type_node, op1);
2135 /* Avoid converting op1 to result_type later. */
2142 if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE))
2143 warning ("comparing floating point with == or != is unsafe");
2144 /* Result of comparison is always int,
2145 but don't convert the args to int! */
2146 build_type = integer_type_node;
2147 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
2148 || code0 == COMPLEX_TYPE
2149 || code0 == VECTOR_TYPE)
2150 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
2151 || code1 == COMPLEX_TYPE
2152 || code1 == VECTOR_TYPE))
2154 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2156 tree tt0 = TREE_TYPE (type0);
2157 tree tt1 = TREE_TYPE (type1);
2158 /* Anything compares with void *. void * compares with anything.
2159 Otherwise, the targets must be compatible
2160 and both must be object or both incomplete. */
2161 if (comp_target_types (type0, type1, 1))
2162 result_type = common_type (type0, type1);
2163 else if (VOID_TYPE_P (tt0))
2165 /* op0 != orig_op0 detects the case of something
2166 whose value is 0 but which isn't a valid null ptr const. */
2167 if (pedantic && (!integer_zerop (op0) || op0 != orig_op0)
2168 && TREE_CODE (tt1) == FUNCTION_TYPE)
2169 pedwarn ("ISO C forbids comparison of `void *' with function pointer");
2171 else if (VOID_TYPE_P (tt1))
2173 if (pedantic && (!integer_zerop (op1) || op1 != orig_op1)
2174 && TREE_CODE (tt0) == FUNCTION_TYPE)
2175 pedwarn ("ISO C forbids comparison of `void *' with function pointer");
2178 pedwarn ("comparison of distinct pointer types lacks a cast");
2180 if (result_type == NULL_TREE)
2181 result_type = ptr_type_node;
2183 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
2184 && integer_zerop (op1))
2185 result_type = type0;
2186 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
2187 && integer_zerop (op0))
2188 result_type = type1;
2189 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2191 result_type = type0;
2192 pedwarn ("comparison between pointer and integer");
2194 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
2196 result_type = type1;
2197 pedwarn ("comparison between pointer and integer");
2203 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
2204 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
2206 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2208 if (comp_target_types (type0, type1, 1))
2210 result_type = common_type (type0, type1);
2212 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
2213 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
2217 result_type = ptr_type_node;
2218 pedwarn ("comparison of distinct pointer types lacks a cast");
2227 build_type = integer_type_node;
2228 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE)
2229 && (code1 == INTEGER_TYPE || code1 == REAL_TYPE))
2231 else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
2233 if (comp_target_types (type0, type1, 1))
2235 result_type = common_type (type0, type1);
2236 if (!COMPLETE_TYPE_P (TREE_TYPE (type0))
2237 != !COMPLETE_TYPE_P (TREE_TYPE (type1)))
2238 pedwarn ("comparison of complete and incomplete pointers");
2240 && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE)
2241 pedwarn ("ISO C forbids ordered comparisons of pointers to functions");
2245 result_type = ptr_type_node;
2246 pedwarn ("comparison of distinct pointer types lacks a cast");
2249 else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST
2250 && integer_zerop (op1))
2252 result_type = type0;
2253 if (pedantic || extra_warnings)
2254 pedwarn ("ordered comparison of pointer with integer zero");
2256 else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST
2257 && integer_zerop (op0))
2259 result_type = type1;
2261 pedwarn ("ordered comparison of pointer with integer zero");
2263 else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
2265 result_type = type0;
2266 pedwarn ("comparison between pointer and integer");
2268 else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE)
2270 result_type = type1;
2271 pedwarn ("comparison between pointer and integer");
2275 case UNORDERED_EXPR:
2282 build_type = integer_type_node;
2283 if (code0 != REAL_TYPE || code1 != REAL_TYPE)
2285 error ("unordered comparison on non-floating point argument");
2286 return error_mark_node;
2295 if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
2296 || code0 == VECTOR_TYPE)
2298 (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
2299 || code1 == VECTOR_TYPE))
2301 int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
2303 if (shorten || common || short_compare)
2304 result_type = common_type (type0, type1);
2306 /* For certain operations (which identify themselves by shorten != 0)
2307 if both args were extended from the same smaller type,
2308 do the arithmetic in that type and then extend.
2310 shorten !=0 and !=1 indicates a bitwise operation.
2311 For them, this optimization is safe only if
2312 both args are zero-extended or both are sign-extended.
2313 Otherwise, we might change the result.
2314 Eg, (short)-1 | (unsigned short)-1 is (int)-1
2315 but calculated in (unsigned short) it would be (unsigned short)-1. */
2317 if (shorten && none_complex)
2319 int unsigned0, unsigned1;
2320 tree arg0 = get_narrower (op0, &unsigned0);
2321 tree arg1 = get_narrower (op1, &unsigned1);
2322 /* UNS is 1 if the operation to be done is an unsigned one. */
2323 int uns = TREE_UNSIGNED (result_type);
2326 final_type = result_type;
2328 /* Handle the case that OP0 (or OP1) does not *contain* a conversion
2329 but it *requires* conversion to FINAL_TYPE. */
2331 if ((TYPE_PRECISION (TREE_TYPE (op0))
2332 == TYPE_PRECISION (TREE_TYPE (arg0)))
2333 && TREE_TYPE (op0) != final_type)
2334 unsigned0 = TREE_UNSIGNED (TREE_TYPE (op0));
2335 if ((TYPE_PRECISION (TREE_TYPE (op1))
2336 == TYPE_PRECISION (TREE_TYPE (arg1)))
2337 && TREE_TYPE (op1) != final_type)
2338 unsigned1 = TREE_UNSIGNED (TREE_TYPE (op1));
2340 /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */
2342 /* For bitwise operations, signedness of nominal type
2343 does not matter. Consider only how operands were extended. */
2347 /* Note that in all three cases below we refrain from optimizing
2348 an unsigned operation on sign-extended args.
2349 That would not be valid. */
2351 /* Both args variable: if both extended in same way
2352 from same width, do it in that width.
2353 Do it unsigned if args were zero-extended. */
2354 if ((TYPE_PRECISION (TREE_TYPE (arg0))
2355 < TYPE_PRECISION (result_type))
2356 && (TYPE_PRECISION (TREE_TYPE (arg1))
2357 == TYPE_PRECISION (TREE_TYPE (arg0)))
2358 && unsigned0 == unsigned1
2359 && (unsigned0 || !uns))
2361 = c_common_signed_or_unsigned_type
2362 (unsigned0, common_type (TREE_TYPE (arg0), TREE_TYPE (arg1)));
2363 else if (TREE_CODE (arg0) == INTEGER_CST
2364 && (unsigned1 || !uns)
2365 && (TYPE_PRECISION (TREE_TYPE (arg1))
2366 < TYPE_PRECISION (result_type))
2368 = c_common_signed_or_unsigned_type (unsigned1,
2370 int_fits_type_p (arg0, type)))
2372 else if (TREE_CODE (arg1) == INTEGER_CST
2373 && (unsigned0 || !uns)
2374 && (TYPE_PRECISION (TREE_TYPE (arg0))
2375 < TYPE_PRECISION (result_type))
2377 = c_common_signed_or_unsigned_type (unsigned0,
2379 int_fits_type_p (arg1, type)))
2383 /* Shifts can be shortened if shifting right. */
2388 tree arg0 = get_narrower (op0, &unsigned_arg);
2390 final_type = result_type;
2392 if (arg0 == op0 && final_type == TREE_TYPE (op0))
2393 unsigned_arg = TREE_UNSIGNED (TREE_TYPE (op0));
2395 if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)
2396 /* We can shorten only if the shift count is less than the
2397 number of bits in the smaller type size. */
2398 && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0
2399 /* We cannot drop an unsigned shift after sign-extension. */
2400 && (!TREE_UNSIGNED (final_type) || unsigned_arg))
2402 /* Do an unsigned shift if the operand was zero-extended. */
2404 = c_common_signed_or_unsigned_type (unsigned_arg,
2406 /* Convert value-to-be-shifted to that type. */
2407 if (TREE_TYPE (op0) != result_type)
2408 op0 = convert (result_type, op0);
2413 /* Comparison operations are shortened too but differently.
2414 They identify themselves by setting short_compare = 1. */
2418 /* Don't write &op0, etc., because that would prevent op0
2419 from being kept in a register.
2420 Instead, make copies of the our local variables and
2421 pass the copies by reference, then copy them back afterward. */
2422 tree xop0 = op0, xop1 = op1, xresult_type = result_type;
2423 enum tree_code xresultcode = resultcode;
2425 = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode);
2430 op0 = xop0, op1 = xop1;
2432 resultcode = xresultcode;
2434 if ((warn_sign_compare < 0 ? extra_warnings : warn_sign_compare != 0)
2435 && skip_evaluation == 0)
2437 int op0_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op0));
2438 int op1_signed = ! TREE_UNSIGNED (TREE_TYPE (orig_op1));
2439 int unsignedp0, unsignedp1;
2440 tree primop0 = get_narrower (op0, &unsignedp0);
2441 tree primop1 = get_narrower (op1, &unsignedp1);
2445 STRIP_TYPE_NOPS (xop0);
2446 STRIP_TYPE_NOPS (xop1);
2448 /* Give warnings for comparisons between signed and unsigned
2449 quantities that may fail.
2451 Do the checking based on the original operand trees, so that
2452 casts will be considered, but default promotions won't be.
2454 Do not warn if the comparison is being done in a signed type,
2455 since the signed type will only be chosen if it can represent
2456 all the values of the unsigned type. */
2457 if (! TREE_UNSIGNED (result_type))
2459 /* Do not warn if both operands are the same signedness. */
2460 else if (op0_signed == op1_signed)
2467 sop = xop0, uop = xop1;
2469 sop = xop1, uop = xop0;
2471 /* Do not warn if the signed quantity is an
2472 unsuffixed integer literal (or some static
2473 constant expression involving such literals or a
2474 conditional expression involving such literals)
2475 and it is non-negative. */
2476 if (c_tree_expr_nonnegative_p (sop))
2478 /* Do not warn if the comparison is an equality operation,
2479 the unsigned quantity is an integral constant, and it
2480 would fit in the result if the result were signed. */
2481 else if (TREE_CODE (uop) == INTEGER_CST
2482 && (resultcode == EQ_EXPR || resultcode == NE_EXPR)
2484 (uop, c_common_signed_type (result_type)))
2486 /* Do not warn if the unsigned quantity is an enumeration
2487 constant and its maximum value would fit in the result
2488 if the result were signed. */
2489 else if (TREE_CODE (uop) == INTEGER_CST
2490 && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE
2492 (TYPE_MAX_VALUE (TREE_TYPE(uop)),
2493 c_common_signed_type (result_type)))
2496 warning ("comparison between signed and unsigned");
2499 /* Warn if two unsigned values are being compared in a size
2500 larger than their original size, and one (and only one) is the
2501 result of a `~' operator. This comparison will always fail.
2503 Also warn if one operand is a constant, and the constant
2504 does not have all bits set that are set in the ~ operand
2505 when it is extended. */
2507 if ((TREE_CODE (primop0) == BIT_NOT_EXPR)
2508 != (TREE_CODE (primop1) == BIT_NOT_EXPR))
2510 if (TREE_CODE (primop0) == BIT_NOT_EXPR)
2511 primop0 = get_narrower (TREE_OPERAND (primop0, 0),
2514 primop1 = get_narrower (TREE_OPERAND (primop1, 0),
2517 if (host_integerp (primop0, 0) || host_integerp (primop1, 0))
2520 HOST_WIDE_INT constant, mask;
2521 int unsignedp, bits;
2523 if (host_integerp (primop0, 0))
2526 unsignedp = unsignedp1;
2527 constant = tree_low_cst (primop0, 0);
2532 unsignedp = unsignedp0;
2533 constant = tree_low_cst (primop1, 0);
2536 bits = TYPE_PRECISION (TREE_TYPE (primop));
2537 if (bits < TYPE_PRECISION (result_type)
2538 && bits < HOST_BITS_PER_WIDE_INT && unsignedp)
2540 mask = (~ (HOST_WIDE_INT) 0) << bits;
2541 if ((mask & constant) != mask)
2542 warning ("comparison of promoted ~unsigned with constant");
2545 else if (unsignedp0 && unsignedp1
2546 && (TYPE_PRECISION (TREE_TYPE (primop0))
2547 < TYPE_PRECISION (result_type))
2548 && (TYPE_PRECISION (TREE_TYPE (primop1))
2549 < TYPE_PRECISION (result_type)))
2550 warning ("comparison of promoted ~unsigned with unsigned");
2556 /* At this point, RESULT_TYPE must be nonzero to avoid an error message.
2557 If CONVERTED is zero, both args will be converted to type RESULT_TYPE.
2558 Then the expression will be built.
2559 It will be given type FINAL_TYPE if that is nonzero;
2560 otherwise, it will be given type RESULT_TYPE. */
2564 binary_op_error (code);
2565 return error_mark_node;
2570 if (TREE_TYPE (op0) != result_type)
2571 op0 = convert (result_type, op0);
2572 if (TREE_TYPE (op1) != result_type)
2573 op1 = convert (result_type, op1);
2576 if (build_type == NULL_TREE)
2577 build_type = result_type;
2580 tree result = build (resultcode, build_type, op0, op1);
2583 folded = fold (result);
2584 if (folded == result)
2585 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
2586 if (final_type != 0)
2587 return convert (final_type, folded);
2593 /* Return true if `t' is known to be non-negative. */
2596 c_tree_expr_nonnegative_p (t)
2599 if (TREE_CODE (t) == STMT_EXPR)
2601 t=COMPOUND_BODY (STMT_EXPR_STMT (t));
2603 /* Find the last statement in the chain, ignoring the final
2604 * scope statement */
2605 while (TREE_CHAIN (t) != NULL_TREE
2606 && TREE_CODE (TREE_CHAIN (t)) != SCOPE_STMT)
2608 return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
2610 return tree_expr_nonnegative_p (t);
2613 /* Return a tree for the difference of pointers OP0 and OP1.
2614 The resulting tree has type int. */
2617 pointer_diff (op0, op1)
2620 tree result, folded;
2621 tree restype = ptrdiff_type_node;
2623 tree target_type = TREE_TYPE (TREE_TYPE (op0));
2624 tree con0, con1, lit0, lit1;
2625 tree orig_op1 = op1;
2627 if (pedantic || warn_pointer_arith)
2629 if (TREE_CODE (target_type) == VOID_TYPE)
2630 pedwarn ("pointer of type `void *' used in subtraction");
2631 if (TREE_CODE (target_type) == FUNCTION_TYPE)
2632 pedwarn ("pointer to a function used in subtraction");
2635 /* If the conversion to ptrdiff_type does anything like widening or
2636 converting a partial to an integral mode, we get a convert_expression
2637 that is in the way to do any simplifications.
2638 (fold-const.c doesn't know that the extra bits won't be needed.
2639 split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a
2640 different mode in place.)
2641 So first try to find a common term here 'by hand'; we want to cover
2642 at least the cases that occur in legal static initializers. */
2643 con0 = TREE_CODE (op0) == NOP_EXPR ? TREE_OPERAND (op0, 0) : op0;
2644 con1 = TREE_CODE (op1) == NOP_EXPR ? TREE_OPERAND (op1, 0) : op1;
2646 if (TREE_CODE (con0) == PLUS_EXPR)
2648 lit0 = TREE_OPERAND (con0, 1);
2649 con0 = TREE_OPERAND (con0, 0);
2652 lit0 = integer_zero_node;
2654 if (TREE_CODE (con1) == PLUS_EXPR)
2656 lit1 = TREE_OPERAND (con1, 1);
2657 con1 = TREE_OPERAND (con1, 0);
2660 lit1 = integer_zero_node;
2662 if (operand_equal_p (con0, con1, 0))
2669 /* First do the subtraction as integers;
2670 then drop through to build the divide operator.
2671 Do not do default conversions on the minus operator
2672 in case restype is a short type. */
2674 op0 = build_binary_op (MINUS_EXPR, convert (restype, op0),
2675 convert (restype, op1), 0);
2676 /* This generates an error if op1 is pointer to incomplete type. */
2677 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1))))
2678 error ("arithmetic on pointer to an incomplete type");
2680 /* This generates an error if op0 is pointer to incomplete type. */
2681 op1 = c_size_in_bytes (target_type);
2683 /* Divide by the size, in easiest possible way. */
2685 result = build (EXACT_DIV_EXPR, restype, op0, convert (restype, op1));
2687 folded = fold (result);
2688 if (folded == result)
2689 TREE_CONSTANT (folded) = TREE_CONSTANT (op0) & TREE_CONSTANT (op1);
2693 /* Construct and perhaps optimize a tree representation
2694 for a unary operation. CODE, a tree_code, specifies the operation
2695 and XARG is the operand.
2696 For any CODE other than ADDR_EXPR, FLAG nonzero suppresses
2697 the default promotions (such as from short to int).
2698 For ADDR_EXPR, the default promotions are not applied; FLAG nonzero
2699 allows non-lvalues; this is only used to handle conversion of non-lvalue
2700 arrays to pointers in C99. */
2703 build_unary_op (code, xarg, flag)
2704 enum tree_code code;
2708 /* No default_conversion here. It causes trouble for ADDR_EXPR. */
2711 enum tree_code typecode = TREE_CODE (TREE_TYPE (arg));
2713 int noconvert = flag;
2715 if (typecode == ERROR_MARK)
2716 return error_mark_node;
2717 if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE)
2718 typecode = INTEGER_TYPE;
2723 /* This is used for unary plus, because a CONVERT_EXPR
2724 is enough to prevent anybody from looking inside for
2725 associativity, but won't generate any code. */
2726 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2727 || typecode == COMPLEX_TYPE))
2729 error ("wrong type argument to unary plus");
2730 return error_mark_node;
2732 else if (!noconvert)
2733 arg = default_conversion (arg);
2734 arg = non_lvalue (arg);
2738 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2739 || typecode == COMPLEX_TYPE
2740 || typecode == VECTOR_TYPE))
2742 error ("wrong type argument to unary minus");
2743 return error_mark_node;
2745 else if (!noconvert)
2746 arg = default_conversion (arg);
2750 if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE)
2753 arg = default_conversion (arg);
2755 else if (typecode == COMPLEX_TYPE)
2759 pedwarn ("ISO C does not support `~' for complex conjugation");
2761 arg = default_conversion (arg);
2765 error ("wrong type argument to bit-complement");
2766 return error_mark_node;
2771 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2772 || typecode == COMPLEX_TYPE))
2774 error ("wrong type argument to abs");
2775 return error_mark_node;
2777 else if (!noconvert)
2778 arg = default_conversion (arg);
2782 /* Conjugating a real value is a no-op, but allow it anyway. */
2783 if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
2784 || typecode == COMPLEX_TYPE))
2786 error ("wrong type argument to conjugation");
2787 return error_mark_node;
2789 else if (!noconvert)
2790 arg = default_conversion (arg);
2793 case TRUTH_NOT_EXPR:
2794 if (typecode != INTEGER_TYPE
2795 && typecode != REAL_TYPE && typecode != POINTER_TYPE
2796 && typecode != COMPLEX_TYPE
2797 /* These will convert to a pointer. */
2798 && typecode != ARRAY_TYPE && typecode != FUNCTION_TYPE)
2800 error ("wrong type argument to unary exclamation mark");
2801 return error_mark_node;
2803 arg = c_common_truthvalue_conversion (arg);
2804 return invert_truthvalue (arg);
2810 if (TREE_CODE (arg) == COMPLEX_CST)
2811 return TREE_REALPART (arg);
2812 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2813 return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
2818 if (TREE_CODE (arg) == COMPLEX_CST)
2819 return TREE_IMAGPART (arg);
2820 else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE)
2821 return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg));
2823 return convert (TREE_TYPE (arg), integer_zero_node);
2825 case PREINCREMENT_EXPR:
2826 case POSTINCREMENT_EXPR:
2827 case PREDECREMENT_EXPR:
2828 case POSTDECREMENT_EXPR:
2829 /* Handle complex lvalues (when permitted)
2830 by reduction to simpler cases. */
2832 val = unary_complex_lvalue (code, arg, 0);
2836 /* Increment or decrement the real part of the value,
2837 and don't change the imaginary part. */
2838 if (typecode == COMPLEX_TYPE)
2843 pedwarn ("ISO C does not support `++' and `--' on complex types");
2845 arg = stabilize_reference (arg);
2846 real = build_unary_op (REALPART_EXPR, arg, 1);
2847 imag = build_unary_op (IMAGPART_EXPR, arg, 1);
2848 return build (COMPLEX_EXPR, TREE_TYPE (arg),
2849 build_unary_op (code, real, 1), imag);
2852 /* Report invalid types. */
2854 if (typecode != POINTER_TYPE
2855 && typecode != INTEGER_TYPE && typecode != REAL_TYPE)
2857 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2858 error ("wrong type argument to increment");
2860 error ("wrong type argument to decrement");
2862 return error_mark_node;
2867 tree result_type = TREE_TYPE (arg);
2869 arg = get_unwidened (arg, 0);
2870 argtype = TREE_TYPE (arg);
2872 /* Compute the increment. */
2874 if (typecode == POINTER_TYPE)
2876 /* If pointer target is an undefined struct,
2877 we just cannot know how to do the arithmetic. */
2878 if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type)))
2880 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2881 error ("increment of pointer to unknown structure");
2883 error ("decrement of pointer to unknown structure");
2885 else if ((pedantic || warn_pointer_arith)
2886 && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE
2887 || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE))
2889 if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR)
2890 pedwarn ("wrong type argument to increment");
2892 pedwarn ("wrong type argument to decrement");
2895 inc = c_size_in_bytes (TREE_TYPE (result_type));
2898 inc = integer_one_node;
2900 inc = convert (argtype, inc);
2902 /* Handle incrementing a cast-expression. */
2905 switch (TREE_CODE (arg))
2910 case FIX_TRUNC_EXPR:
2911 case FIX_FLOOR_EXPR:
2912 case FIX_ROUND_EXPR:
2914 pedantic_lvalue_warning (CONVERT_EXPR);
2915 /* If the real type has the same machine representation
2916 as the type it is cast to, we can make better output
2917 by adding directly to the inside of the cast. */
2918 if ((TREE_CODE (TREE_TYPE (arg))
2919 == TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0))))
2920 && (TYPE_MODE (TREE_TYPE (arg))
2921 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (arg, 0)))))
2922 arg = TREE_OPERAND (arg, 0);
2925 tree incremented, modify, value;
2926 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2927 value = boolean_increment (code, arg);
2930 arg = stabilize_reference (arg);
2931 if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR)
2934 value = save_expr (arg);
2935 incremented = build (((code == PREINCREMENT_EXPR
2936 || code == POSTINCREMENT_EXPR)
2937 ? PLUS_EXPR : MINUS_EXPR),
2938 argtype, value, inc);
2939 TREE_SIDE_EFFECTS (incremented) = 1;
2940 modify = build_modify_expr (arg, NOP_EXPR, incremented);
2941 value = build (COMPOUND_EXPR, TREE_TYPE (arg), modify, value);
2943 TREE_USED (value) = 1;
2953 /* Complain about anything else that is not a true lvalue. */
2954 if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR
2955 || code == POSTINCREMENT_EXPR)
2956 ? "invalid lvalue in increment"
2957 : "invalid lvalue in decrement")))
2958 return error_mark_node;
2960 /* Report a read-only lvalue. */
2961 if (TREE_READONLY (arg))
2962 readonly_warning (arg,
2963 ((code == PREINCREMENT_EXPR
2964 || code == POSTINCREMENT_EXPR)
2965 ? "increment" : "decrement"));
2967 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
2968 val = boolean_increment (code, arg);
2970 val = build (code, TREE_TYPE (arg), arg, inc);
2971 TREE_SIDE_EFFECTS (val) = 1;
2972 val = convert (result_type, val);
2973 if (TREE_CODE (val) != code)
2974 TREE_NO_UNUSED_WARNING (val) = 1;
2979 /* Note that this operation never does default_conversion. */
2981 /* Let &* cancel out to simplify resulting code. */
2982 if (TREE_CODE (arg) == INDIRECT_REF)
2984 /* Don't let this be an lvalue. */
2985 if (lvalue_p (TREE_OPERAND (arg, 0)))
2986 return non_lvalue (TREE_OPERAND (arg, 0));
2987 return TREE_OPERAND (arg, 0);
2990 /* For &x[y], return x+y */
2991 if (TREE_CODE (arg) == ARRAY_REF)
2993 if (!c_mark_addressable (TREE_OPERAND (arg, 0)))
2994 return error_mark_node;
2995 return build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0),
2996 TREE_OPERAND (arg, 1), 1);
2999 /* Handle complex lvalues (when permitted)
3000 by reduction to simpler cases. */
3001 val = unary_complex_lvalue (code, arg, flag);
3005 #if 0 /* Turned off because inconsistent;
3006 float f; *&(int)f = 3.4 stores in int format
3007 whereas (int)f = 3.4 stores in float format. */
3008 /* Address of a cast is just a cast of the address
3009 of the operand of the cast. */
3010 switch (TREE_CODE (arg))
3015 case FIX_TRUNC_EXPR:
3016 case FIX_FLOOR_EXPR:
3017 case FIX_ROUND_EXPR:
3020 pedwarn ("ISO C forbids the address of a cast expression");
3021 return convert (build_pointer_type (TREE_TYPE (arg)),
3022 build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0),
3027 /* Anything not already handled and not a true memory reference
3028 or a non-lvalue array is an error. */
3029 else if (typecode != FUNCTION_TYPE && !flag
3030 && !lvalue_or_else (arg, "invalid lvalue in unary `&'"))
3031 return error_mark_node;
3033 /* Ordinary case; arg is a COMPONENT_REF or a decl. */
3034 argtype = TREE_TYPE (arg);
3036 /* If the lvalue is const or volatile, merge that into the type
3037 to which the address will point. Note that you can't get a
3038 restricted pointer by taking the address of something, so we
3039 only have to deal with `const' and `volatile' here. */
3040 if ((DECL_P (arg) || TREE_CODE_CLASS (TREE_CODE (arg)) == 'r')
3041 && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg)))
3042 argtype = c_build_type_variant (argtype,
3043 TREE_READONLY (arg),
3044 TREE_THIS_VOLATILE (arg));
3046 argtype = build_pointer_type (argtype);
3048 if (!c_mark_addressable (arg))
3049 return error_mark_node;
3054 if (TREE_CODE (arg) == COMPONENT_REF)
3056 tree field = TREE_OPERAND (arg, 1);
3058 addr = build_unary_op (ADDR_EXPR, TREE_OPERAND (arg, 0), flag);
3060 if (DECL_C_BIT_FIELD (field))
3062 error ("attempt to take address of bit-field structure member `%s'",
3063 IDENTIFIER_POINTER (DECL_NAME (field)));
3064 return error_mark_node;
3067 addr = fold (build (PLUS_EXPR, argtype,
3068 convert (argtype, addr),
3069 convert (argtype, byte_position (field))));
3072 addr = build1 (code, argtype, arg);
3074 /* Address of a static or external variable or
3075 file-scope function counts as a constant. */
3077 && ! (TREE_CODE (arg) == FUNCTION_DECL
3078 && DECL_CONTEXT (arg) != 0))
3079 TREE_CONSTANT (addr) = 1;
3088 argtype = TREE_TYPE (arg);
3089 return fold (build1 (code, argtype, arg));
3093 /* If CONVERSIONS is a conversion expression or a nested sequence of such,
3094 convert ARG with the same conversions in the same order
3095 and return the result. */
3098 convert_sequence (conversions, arg)
3102 switch (TREE_CODE (conversions))
3107 case FIX_TRUNC_EXPR:
3108 case FIX_FLOOR_EXPR:
3109 case FIX_ROUND_EXPR:
3111 return convert (TREE_TYPE (conversions),
3112 convert_sequence (TREE_OPERAND (conversions, 0),
3121 /* Return nonzero if REF is an lvalue valid for this language.
3122 Lvalues can be assigned, unless their type has TYPE_READONLY.
3123 Lvalues can have their address taken, unless they have DECL_REGISTER. */
3129 enum tree_code code = TREE_CODE (ref);
3136 return lvalue_p (TREE_OPERAND (ref, 0));
3138 case COMPOUND_LITERAL_EXPR:
3148 return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE
3149 && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE);
3153 return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE;
3160 /* Return nonzero if REF is an lvalue valid for this language;
3161 otherwise, print an error message and return zero. */
3164 lvalue_or_else (ref, msgid)
3168 int win = lvalue_p (ref);
3171 error ("%s", msgid);
3176 /* Apply unary lvalue-demanding operator CODE to the expression ARG
3177 for certain kinds of expressions which are not really lvalues
3178 but which we can accept as lvalues. If FLAG is nonzero, then
3179 non-lvalues are OK since we may be converting a non-lvalue array to
3182 If ARG is not a kind of expression we can handle, return zero. */
3185 unary_complex_lvalue (code, arg, flag)
3186 enum tree_code code;
3190 /* Handle (a, b) used as an "lvalue". */
3191 if (TREE_CODE (arg) == COMPOUND_EXPR)
3193 tree real_result = build_unary_op (code, TREE_OPERAND (arg, 1), 0);
3195 /* If this returns a function type, it isn't really being used as
3196 an lvalue, so don't issue a warning about it. */
3197 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag)
3198 pedantic_lvalue_warning (COMPOUND_EXPR);
3200 return build (COMPOUND_EXPR, TREE_TYPE (real_result),
3201 TREE_OPERAND (arg, 0), real_result);
3204 /* Handle (a ? b : c) used as an "lvalue". */
3205 if (TREE_CODE (arg) == COND_EXPR)
3208 pedantic_lvalue_warning (COND_EXPR);
3209 if (TREE_CODE (TREE_TYPE (arg)) != FUNCTION_TYPE && !flag)
3210 pedantic_lvalue_warning (COMPOUND_EXPR);
3212 return (build_conditional_expr
3213 (TREE_OPERAND (arg, 0),
3214 build_unary_op (code, TREE_OPERAND (arg, 1), flag),
3215 build_unary_op (code, TREE_OPERAND (arg, 2), flag)));
3221 /* If pedantic, warn about improper lvalue. CODE is either COND_EXPR
3222 COMPOUND_EXPR, or CONVERT_EXPR (for casts). */
3225 pedantic_lvalue_warning (code)
3226 enum tree_code code;
3232 pedwarn ("ISO C forbids use of conditional expressions as lvalues");
3235 pedwarn ("ISO C forbids use of compound expressions as lvalues");
3238 pedwarn ("ISO C forbids use of cast expressions as lvalues");
3243 /* Warn about storing in something that is `const'. */
3246 readonly_warning (arg, msgid)
3250 if (TREE_CODE (arg) == COMPONENT_REF)
3252 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
3253 readonly_warning (TREE_OPERAND (arg, 0), msgid);
3255 pedwarn ("%s of read-only member `%s'", _(msgid),
3256 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (arg, 1))));
3258 else if (TREE_CODE (arg) == VAR_DECL)
3259 pedwarn ("%s of read-only variable `%s'", _(msgid),
3260 IDENTIFIER_POINTER (DECL_NAME (arg)));
3262 pedwarn ("%s of read-only location", _(msgid));
3265 /* Mark EXP saying that we need to be able to take the
3266 address of it; it should not be allocated in a register.
3267 Returns true if successful. */
3270 c_mark_addressable (exp)
3276 switch (TREE_CODE (x))
3279 if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1)))
3281 error ("cannot take address of bit-field `%s'",
3282 IDENTIFIER_POINTER (DECL_NAME (TREE_OPERAND (x, 1))));
3286 /* ... fall through ... */
3292 x = TREE_OPERAND (x, 0);
3295 case COMPOUND_LITERAL_EXPR:
3297 TREE_ADDRESSABLE (x) = 1;
3304 if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x)
3305 && DECL_NONLOCAL (x))
3307 if (TREE_PUBLIC (x))
3309 error ("global register variable `%s' used in nested function",
3310 IDENTIFIER_POINTER (DECL_NAME (x)));
3313 pedwarn ("register variable `%s' used in nested function",
3314 IDENTIFIER_POINTER (DECL_NAME (x)));
3316 else if (DECL_REGISTER (x) && !TREE_ADDRESSABLE (x))
3318 if (TREE_PUBLIC (x))
3320 error ("address of global register variable `%s' requested",
3321 IDENTIFIER_POINTER (DECL_NAME (x)));
3325 /* If we are making this addressable due to its having
3326 volatile components, give a different error message. Also
3327 handle the case of an unnamed parameter by not trying
3328 to give the name. */
3330 else if (C_TYPE_FIELDS_VOLATILE (TREE_TYPE (x)))
3332 error ("cannot put object with volatile field into register");
3336 pedwarn ("address of register variable `%s' requested",
3337 IDENTIFIER_POINTER (DECL_NAME (x)));
3339 put_var_into_stack (x);
3343 TREE_ADDRESSABLE (x) = 1;
3344 #if 0 /* poplevel deals with this now. */
3345 if (DECL_CONTEXT (x) == 0)
3346 TREE_ADDRESSABLE (DECL_ASSEMBLER_NAME (x)) = 1;
3354 /* Build and return a conditional expression IFEXP ? OP1 : OP2. */
3357 build_conditional_expr (ifexp, op1, op2)
3358 tree ifexp, op1, op2;
3362 enum tree_code code1;
3363 enum tree_code code2;
3364 tree result_type = NULL;
3365 tree orig_op1 = op1, orig_op2 = op2;
3367 ifexp = c_common_truthvalue_conversion (default_conversion (ifexp));
3369 #if 0 /* Produces wrong result if within sizeof. */
3370 /* Don't promote the operands separately if they promote
3371 the same way. Return the unpromoted type and let the combined
3372 value get promoted if necessary. */
3374 if (TREE_TYPE (op1) == TREE_TYPE (op2)
3375 && TREE_CODE (TREE_TYPE (op1)) != ARRAY_TYPE
3376 && TREE_CODE (TREE_TYPE (op1)) != ENUMERAL_TYPE
3377 && TREE_CODE (TREE_TYPE (op1)) != FUNCTION_TYPE)
3379 if (TREE_CODE (ifexp) == INTEGER_CST)
3380 return pedantic_non_lvalue (integer_zerop (ifexp) ? op2 : op1);
3382 return fold (build (COND_EXPR, TREE_TYPE (op1), ifexp, op1, op2));
3386 /* Promote both alternatives. */
3388 if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE)
3389 op1 = default_conversion (op1);
3390 if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE)
3391 op2 = default_conversion (op2);
3393 if (TREE_CODE (ifexp) == ERROR_MARK
3394 || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK
3395 || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK)
3396 return error_mark_node;
3398 type1 = TREE_TYPE (op1);
3399 code1 = TREE_CODE (type1);
3400 type2 = TREE_TYPE (op2);
3401 code2 = TREE_CODE (type2);
3403 /* Quickly detect the usual case where op1 and op2 have the same type
3405 if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2))
3408 result_type = type1;
3410 result_type = TYPE_MAIN_VARIANT (type1);
3412 else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE
3413 || code1 == COMPLEX_TYPE)
3414 && (code2 == INTEGER_TYPE || code2 == REAL_TYPE
3415 || code2 == COMPLEX_TYPE))
3417 result_type = common_type (type1, type2);
3419 /* If -Wsign-compare, warn here if type1 and type2 have
3420 different signedness. We'll promote the signed to unsigned
3421 and later code won't know it used to be different.
3422 Do this check on the original types, so that explicit casts
3423 will be considered, but default promotions won't. */
3424 if ((warn_sign_compare < 0 ? extra_warnings : warn_sign_compare)
3425 && !skip_evaluation)
3427 int unsigned_op1 = TREE_UNSIGNED (TREE_TYPE (orig_op1));
3428 int unsigned_op2 = TREE_UNSIGNED (TREE_TYPE (orig_op2));
3430 if (unsigned_op1 ^ unsigned_op2)
3432 /* Do not warn if the result type is signed, since the
3433 signed type will only be chosen if it can represent
3434 all the values of the unsigned type. */
3435 if (! TREE_UNSIGNED (result_type))
3437 /* Do not warn if the signed quantity is an unsuffixed
3438 integer literal (or some static constant expression
3439 involving such literals) and it is non-negative. */
3440 else if ((unsigned_op2 && c_tree_expr_nonnegative_p (op1))
3441 || (unsigned_op1 && c_tree_expr_nonnegative_p (op2)))
3444 warning ("signed and unsigned type in conditional expression");
3448 else if (code1 == VOID_TYPE || code2 == VOID_TYPE)
3450 if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE))
3451 pedwarn ("ISO C forbids conditional expr with only one void side");
3452 result_type = void_type_node;
3454 else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE)
3456 if (comp_target_types (type1, type2, 1))
3457 result_type = common_type (type1, type2);
3458 else if (integer_zerop (op1) && TREE_TYPE (type1) == void_type_node
3459 && TREE_CODE (orig_op1) != NOP_EXPR)
3460 result_type = qualify_type (type2, type1);
3461 else if (integer_zerop (op2) && TREE_TYPE (type2) == void_type_node
3462 && TREE_CODE (orig_op2) != NOP_EXPR)
3463 result_type = qualify_type (type1, type2);
3464 else if (VOID_TYPE_P (TREE_TYPE (type1)))
3466 if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE)
3467 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer");
3468 result_type = build_pointer_type (qualify_type (TREE_TYPE (type1),
3469 TREE_TYPE (type2)));
3471 else if (VOID_TYPE_P (TREE_TYPE (type2)))
3473 if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE)
3474 pedwarn ("ISO C forbids conditional expr between `void *' and function pointer");
3475 result_type = build_pointer_type (qualify_type (TREE_TYPE (type2),
3476 TREE_TYPE (type1)));
3480 pedwarn ("pointer type mismatch in conditional expression");
3481 result_type = build_pointer_type (void_type_node);
3484 else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE)
3486 if (! integer_zerop (op2))
3487 pedwarn ("pointer/integer type mismatch in conditional expression");
3490 op2 = null_pointer_node;
3492 result_type = type1;
3494 else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE)
3496 if (!integer_zerop (op1))
3497 pedwarn ("pointer/integer type mismatch in conditional expression");
3500 op1 = null_pointer_node;
3502 result_type = type2;
3507 if (flag_cond_mismatch)
3508 result_type = void_type_node;
3511 error ("type mismatch in conditional expression");
3512 return error_mark_node;
3516 /* Merge const and volatile flags of the incoming types. */
3518 = build_type_variant (result_type,
3519 TREE_READONLY (op1) || TREE_READONLY (op2),
3520 TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2));
3522 if (result_type != TREE_TYPE (op1))
3523 op1 = convert_and_check (result_type, op1);
3524 if (result_type != TREE_TYPE (op2))
3525 op2 = convert_and_check (result_type, op2);
3527 if (TREE_CODE (ifexp) == INTEGER_CST)
3528 return pedantic_non_lvalue (integer_zerop (ifexp) ? op2 : op1);
3530 return fold (build (COND_EXPR, result_type, ifexp, op1, op2));
3533 /* Given a list of expressions, return a compound expression
3534 that performs them all and returns the value of the last of them. */
3537 build_compound_expr (list)
3540 return internal_build_compound_expr (list, TRUE);
3544 internal_build_compound_expr (list, first_p)
3550 if (TREE_CHAIN (list) == 0)
3552 /* Convert arrays and functions to pointers when there
3553 really is a comma operator. */
3556 = default_function_array_conversion (TREE_VALUE (list));
3558 #if 0 /* If something inside inhibited lvalueness, we should not override. */
3559 /* Consider (x, y+0), which is not an lvalue since y+0 is not. */
3561 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3562 if (TREE_CODE (list) == NON_LVALUE_EXPR)
3563 list = TREE_OPERAND (list, 0);
3566 /* Don't let (0, 0) be null pointer constant. */
3567 if (!first_p && integer_zerop (TREE_VALUE (list)))
3568 return non_lvalue (TREE_VALUE (list));
3569 return TREE_VALUE (list);
3572 rest = internal_build_compound_expr (TREE_CHAIN (list), FALSE);
3574 if (! TREE_SIDE_EFFECTS (TREE_VALUE (list)))
3576 /* The left-hand operand of a comma expression is like an expression
3577 statement: with -Wextra or -Wunused, we should warn if it doesn't have
3578 any side-effects, unless it was explicitly cast to (void). */
3579 if ((extra_warnings || warn_unused_value)
3580 && ! (TREE_CODE (TREE_VALUE (list)) == CONVERT_EXPR
3581 && VOID_TYPE_P (TREE_TYPE (TREE_VALUE (list)))))
3582 warning ("left-hand operand of comma expression has no effect");
3584 /* When pedantic, a compound expression can be neither an lvalue
3585 nor an integer constant expression. */
3590 /* With -Wunused, we should also warn if the left-hand operand does have
3591 side-effects, but computes a value which is not used. For example, in
3592 `foo() + bar(), baz()' the result of the `+' operator is not used,
3593 so we should issue a warning. */
3594 else if (warn_unused_value)
3595 warn_if_unused_value (TREE_VALUE (list));
3597 return build (COMPOUND_EXPR, TREE_TYPE (rest), TREE_VALUE (list), rest);
3600 /* Build an expression representing a cast to type TYPE of expression EXPR. */
3603 build_c_cast (type, expr)
3609 if (type == error_mark_node || expr == error_mark_node)
3610 return error_mark_node;
3612 /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing
3613 only in <protocol> qualifications. But when constructing cast expressions,
3614 the protocols do matter and must be kept around. */
3615 if (!flag_objc || !objc_is_id (type))
3616 type = TYPE_MAIN_VARIANT (type);
3619 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3620 if (TREE_CODE (value) == NON_LVALUE_EXPR)
3621 value = TREE_OPERAND (value, 0);
3624 if (TREE_CODE (type) == ARRAY_TYPE)
3626 error ("cast specifies array type");
3627 return error_mark_node;
3630 if (TREE_CODE (type) == FUNCTION_TYPE)
3632 error ("cast specifies function type");
3633 return error_mark_node;
3636 if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value)))
3640 if (TREE_CODE (type) == RECORD_TYPE
3641 || TREE_CODE (type) == UNION_TYPE)
3642 pedwarn ("ISO C forbids casting nonscalar to the same type");
3645 else if (TREE_CODE (type) == UNION_TYPE)
3648 value = default_function_array_conversion (value);
3650 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3651 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)),
3652 TYPE_MAIN_VARIANT (TREE_TYPE (value))))
3660 pedwarn ("ISO C forbids casts to union type");
3661 t = digest_init (type, build (CONSTRUCTOR, type, NULL_TREE,
3662 build_tree_list (field, value)), 0);
3663 TREE_CONSTANT (t) = TREE_CONSTANT (value);
3666 error ("cast to union type from type not present in union");
3667 return error_mark_node;
3673 /* If casting to void, avoid the error that would come
3674 from default_conversion in the case of a non-lvalue array. */
3675 if (type == void_type_node)
3676 return build1 (CONVERT_EXPR, type, value);
3678 /* Convert functions and arrays to pointers,
3679 but don't convert any other types. */
3680 value = default_function_array_conversion (value);
3681 otype = TREE_TYPE (value);
3683 /* Optionally warn about potentially worrisome casts. */
3686 && TREE_CODE (type) == POINTER_TYPE
3687 && TREE_CODE (otype) == POINTER_TYPE)
3689 tree in_type = type;
3690 tree in_otype = otype;
3694 /* Check that the qualifiers on IN_TYPE are a superset of
3695 the qualifiers of IN_OTYPE. The outermost level of
3696 POINTER_TYPE nodes is uninteresting and we stop as soon
3697 as we hit a non-POINTER_TYPE node on either type. */
3700 in_otype = TREE_TYPE (in_otype);
3701 in_type = TREE_TYPE (in_type);
3703 /* GNU C allows cv-qualified function types. 'const'
3704 means the function is very pure, 'volatile' means it
3705 can't return. We need to warn when such qualifiers
3706 are added, not when they're taken away. */
3707 if (TREE_CODE (in_otype) == FUNCTION_TYPE
3708 && TREE_CODE (in_type) == FUNCTION_TYPE)
3709 added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype));
3711 discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type));
3713 while (TREE_CODE (in_type) == POINTER_TYPE
3714 && TREE_CODE (in_otype) == POINTER_TYPE);
3717 warning ("cast adds new qualifiers to function type");
3720 /* There are qualifiers present in IN_OTYPE that are not
3721 present in IN_TYPE. */
3722 warning ("cast discards qualifiers from pointer target type");
3725 /* Warn about possible alignment problems. */
3726 if (STRICT_ALIGNMENT && warn_cast_align
3727 && TREE_CODE (type) == POINTER_TYPE
3728 && TREE_CODE (otype) == POINTER_TYPE
3729 && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE
3730 && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE
3731 /* Don't warn about opaque types, where the actual alignment
3732 restriction is unknown. */
3733 && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE
3734 || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE)
3735 && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode)
3736 && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype)))
3737 warning ("cast increases required alignment of target type");
3739 if (TREE_CODE (type) == INTEGER_TYPE
3740 && TREE_CODE (otype) == POINTER_TYPE
3741 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3742 && !TREE_CONSTANT (value))
3743 warning ("cast from pointer to integer of different size");
3745 if (warn_bad_function_cast
3746 && TREE_CODE (value) == CALL_EXPR
3747 && TREE_CODE (type) != TREE_CODE (otype))
3748 warning ("cast does not match function type");
3750 if (TREE_CODE (type) == POINTER_TYPE
3751 && TREE_CODE (otype) == INTEGER_TYPE
3752 && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
3753 /* Don't warn about converting any constant. */
3754 && !TREE_CONSTANT (value))
3755 warning ("cast to pointer from integer of different size");
3757 if (TREE_CODE (type) == POINTER_TYPE
3758 && TREE_CODE (otype) == POINTER_TYPE
3759 && TREE_CODE (expr) == ADDR_EXPR
3760 && DECL_P (TREE_OPERAND (expr, 0))
3761 && flag_strict_aliasing && warn_strict_aliasing
3762 && !VOID_TYPE_P (TREE_TYPE (type)))
3764 /* Casting the address of a decl to non void pointer. Warn
3765 if the cast breaks type based aliasing. */
3766 if (!COMPLETE_TYPE_P (TREE_TYPE (type)))
3767 warning ("type-punning to incomplete type might break strict-aliasing rules");
3768 else if (!alias_sets_conflict_p
3769 (get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))),
3770 get_alias_set (TREE_TYPE (type))))
3771 warning ("dereferencing type-punned pointer will break strict-aliasing rules");
3775 /* Replace a nonvolatile const static variable with its value. */
3776 if (optimize && TREE_CODE (value) == VAR_DECL)
3777 value = decl_constant_value (value);
3778 value = convert (type, value);
3780 /* Ignore any integer overflow caused by the cast. */
3781 if (TREE_CODE (value) == INTEGER_CST)
3783 TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue);
3784 TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue);
3788 /* Pedantically, don't let (void *) (FOO *) 0 be a null pointer constant. */
3789 if (pedantic && TREE_CODE (value) == INTEGER_CST
3790 && TREE_CODE (expr) == INTEGER_CST
3791 && TREE_CODE (TREE_TYPE (expr)) != INTEGER_TYPE)
3792 value = non_lvalue (value);
3794 /* If pedantic, don't let a cast be an lvalue. */
3795 if (value == expr && pedantic)
3796 value = non_lvalue (value);
3801 /* Interpret a cast of expression EXPR to type TYPE. */
3803 c_cast_expr (type, expr)
3806 int saved_wsp = warn_strict_prototypes;
3808 /* This avoids warnings about unprototyped casts on
3809 integers. E.g. "#define SIG_DFL (void(*)())0". */
3810 if (TREE_CODE (expr) == INTEGER_CST)
3811 warn_strict_prototypes = 0;
3812 type = groktypename (type);
3813 warn_strict_prototypes = saved_wsp;
3815 return build_c_cast (type, expr);
3819 /* Build an assignment expression of lvalue LHS from value RHS.
3820 MODIFYCODE is the code for a binary operator that we use
3821 to combine the old value of LHS with RHS to get the new value.
3822 Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */
3825 build_modify_expr (lhs, modifycode, rhs)
3827 enum tree_code modifycode;
3831 tree lhstype = TREE_TYPE (lhs);
3832 tree olhstype = lhstype;
3834 /* Types that aren't fully specified cannot be used in assignments. */
3835 lhs = require_complete_type (lhs);
3837 /* Avoid duplicate error messages from operands that had errors. */
3838 if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK)
3839 return error_mark_node;
3841 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
3842 /* Do not use STRIP_NOPS here. We do not want an enumerator
3843 whose value is 0 to count as a null pointer constant. */
3844 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
3845 rhs = TREE_OPERAND (rhs, 0);
3849 /* Handle control structure constructs used as "lvalues". */
3851 switch (TREE_CODE (lhs))
3853 /* Handle (a, b) used as an "lvalue". */
3855 pedantic_lvalue_warning (COMPOUND_EXPR);
3856 newrhs = build_modify_expr (TREE_OPERAND (lhs, 1), modifycode, rhs);
3857 if (TREE_CODE (newrhs) == ERROR_MARK)
3858 return error_mark_node;
3859 return build (COMPOUND_EXPR, lhstype,
3860 TREE_OPERAND (lhs, 0), newrhs);
3862 /* Handle (a ? b : c) used as an "lvalue". */
3864 pedantic_lvalue_warning (COND_EXPR);
3865 rhs = save_expr (rhs);
3867 /* Produce (a ? (b = rhs) : (c = rhs))
3868 except that the RHS goes through a save-expr
3869 so the code to compute it is only emitted once. */
3871 = build_conditional_expr (TREE_OPERAND (lhs, 0),
3872 build_modify_expr (TREE_OPERAND (lhs, 1),
3874 build_modify_expr (TREE_OPERAND (lhs, 2),
3876 if (TREE_CODE (cond) == ERROR_MARK)
3878 /* Make sure the code to compute the rhs comes out
3879 before the split. */
3880 return build (COMPOUND_EXPR, TREE_TYPE (lhs),
3881 /* But cast it to void to avoid an "unused" error. */
3882 convert (void_type_node, rhs), cond);
3888 /* If a binary op has been requested, combine the old LHS value with the RHS
3889 producing the value we should actually store into the LHS. */
3891 if (modifycode != NOP_EXPR)
3893 lhs = stabilize_reference (lhs);
3894 newrhs = build_binary_op (modifycode, lhs, rhs, 1);
3897 /* Handle a cast used as an "lvalue".
3898 We have already performed any binary operator using the value as cast.
3899 Now convert the result to the cast type of the lhs,
3900 and then true type of the lhs and store it there;
3901 then convert result back to the cast type to be the value
3902 of the assignment. */
3904 switch (TREE_CODE (lhs))
3909 case FIX_TRUNC_EXPR:
3910 case FIX_FLOOR_EXPR:
3911 case FIX_ROUND_EXPR:
3913 newrhs = default_function_array_conversion (newrhs);
3915 tree inner_lhs = TREE_OPERAND (lhs, 0);
3917 result = build_modify_expr (inner_lhs, NOP_EXPR,
3918 convert (TREE_TYPE (inner_lhs),
3919 convert (lhstype, newrhs)));
3920 if (TREE_CODE (result) == ERROR_MARK)
3922 pedantic_lvalue_warning (CONVERT_EXPR);
3923 return convert (TREE_TYPE (lhs), result);
3930 /* Now we have handled acceptable kinds of LHS that are not truly lvalues.
3931 Reject anything strange now. */
3933 if (!lvalue_or_else (lhs, "invalid lvalue in assignment"))
3934 return error_mark_node;
3936 /* Warn about storing in something that is `const'. */
3938 if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype)
3939 || ((TREE_CODE (lhstype) == RECORD_TYPE
3940 || TREE_CODE (lhstype) == UNION_TYPE)
3941 && C_TYPE_FIELDS_READONLY (lhstype)))
3942 readonly_warning (lhs, "assignment");
3944 /* If storing into a structure or union member,
3945 it has probably been given type `int'.
3946 Compute the type that would go with
3947 the actual amount of storage the member occupies. */
3949 if (TREE_CODE (lhs) == COMPONENT_REF
3950 && (TREE_CODE (lhstype) == INTEGER_TYPE
3951 || TREE_CODE (lhstype) == BOOLEAN_TYPE
3952 || TREE_CODE (lhstype) == REAL_TYPE
3953 || TREE_CODE (lhstype) == ENUMERAL_TYPE))
3954 lhstype = TREE_TYPE (get_unwidened (lhs, 0));
3956 /* If storing in a field that is in actuality a short or narrower than one,
3957 we must store in the field in its actual type. */
3959 if (lhstype != TREE_TYPE (lhs))
3961 lhs = copy_node (lhs);
3962 TREE_TYPE (lhs) = lhstype;
3965 /* Convert new value to destination type. */
3967 newrhs = convert_for_assignment (lhstype, newrhs, _("assignment"),
3968 NULL_TREE, NULL_TREE, 0);
3969 if (TREE_CODE (newrhs) == ERROR_MARK)
3970 return error_mark_node;
3974 result = build (MODIFY_EXPR, lhstype, lhs, newrhs);
3975 TREE_SIDE_EFFECTS (result) = 1;
3977 /* If we got the LHS in a different type for storing in,
3978 convert the result back to the nominal type of LHS
3979 so that the value we return always has the same type
3980 as the LHS argument. */
3982 if (olhstype == TREE_TYPE (result))
3984 return convert_for_assignment (olhstype, result, _("assignment"),
3985 NULL_TREE, NULL_TREE, 0);
3988 /* Convert value RHS to type TYPE as preparation for an assignment
3989 to an lvalue of type TYPE.
3990 The real work of conversion is done by `convert'.
3991 The purpose of this function is to generate error messages
3992 for assignments that are not allowed in C.
3993 ERRTYPE is a string to use in error messages:
3994 "assignment", "return", etc. If it is null, this is parameter passing
3995 for a function call (and different error messages are output).
3997 FUNNAME is the name of the function being called,
3998 as an IDENTIFIER_NODE, or null.
3999 PARMNUM is the number of the argument, for printing in error messages. */
4002 convert_for_assignment (type, rhs, errtype, fundecl, funname, parmnum)
4004 const char *errtype;
4005 tree fundecl, funname;
4008 enum tree_code codel = TREE_CODE (type);
4010 enum tree_code coder;
4012 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4013 /* Do not use STRIP_NOPS here. We do not want an enumerator
4014 whose value is 0 to count as a null pointer constant. */
4015 if (TREE_CODE (rhs) == NON_LVALUE_EXPR)
4016 rhs = TREE_OPERAND (rhs, 0);
4018 if (TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE
4019 || TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE)
4020 rhs = default_conversion (rhs);
4021 else if (optimize && TREE_CODE (rhs) == VAR_DECL)
4022 rhs = decl_constant_value_for_broken_optimization (rhs);
4024 rhstype = TREE_TYPE (rhs);
4025 coder = TREE_CODE (rhstype);
4027 if (coder == ERROR_MARK)
4028 return error_mark_node;
4030 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype))
4032 overflow_warning (rhs);
4033 /* Check for Objective-C protocols. This will automatically
4034 issue a warning if there are protocol violations. No need to
4035 use the return value. */
4037 objc_comptypes (type, rhstype, 0);
4041 if (coder == VOID_TYPE)
4043 error ("void value not ignored as it ought to be");
4044 return error_mark_node;
4046 /* A type converts to a reference to it.
4047 This code doesn't fully support references, it's just for the
4048 special case of va_start and va_copy. */
4049 if (codel == REFERENCE_TYPE
4050 && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1)
4052 if (!lvalue_p (rhs))
4054 error ("cannot pass rvalue to reference parameter");
4055 return error_mark_node;
4057 if (!c_mark_addressable (rhs))
4058 return error_mark_node;
4059 rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs);
4061 /* We already know that these two types are compatible, but they
4062 may not be exactly identical. In fact, `TREE_TYPE (type)' is
4063 likely to be __builtin_va_list and `TREE_TYPE (rhs)' is
4064 likely to be va_list, a typedef to __builtin_va_list, which
4065 is different enough that it will cause problems later. */
4066 if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type))
4067 rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs);
4069 rhs = build1 (NOP_EXPR, type, rhs);
4072 /* Some types can interconvert without explicit casts. */
4073 else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE
4074 && (*targetm.vector_types_compatible) (type, rhstype))
4075 return convert (type, rhs);
4076 /* Arithmetic types all interconvert, and enum is treated like int. */
4077 else if ((codel == INTEGER_TYPE || codel == REAL_TYPE
4078 || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
4079 || codel == BOOLEAN_TYPE)
4080 && (coder == INTEGER_TYPE || coder == REAL_TYPE
4081 || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
4082 || coder == BOOLEAN_TYPE))
4083 return convert_and_check (type, rhs);
4085 /* Conversion to a transparent union from its member types.
4086 This applies only to function arguments. */
4087 else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) && ! errtype)
4090 tree marginal_memb_type = 0;
4092 for (memb_types = TYPE_FIELDS (type); memb_types;
4093 memb_types = TREE_CHAIN (memb_types))
4095 tree memb_type = TREE_TYPE (memb_types);
4097 if (comptypes (TYPE_MAIN_VARIANT (memb_type),
4098 TYPE_MAIN_VARIANT (rhstype)))
4101 if (TREE_CODE (memb_type) != POINTER_TYPE)
4104 if (coder == POINTER_TYPE)
4106 tree ttl = TREE_TYPE (memb_type);
4107 tree ttr = TREE_TYPE (rhstype);
4109 /* Any non-function converts to a [const][volatile] void *
4110 and vice versa; otherwise, targets must be the same.
4111 Meanwhile, the lhs target must have all the qualifiers of
4113 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4114 || comp_target_types (memb_type, rhstype, 0))
4116 /* If this type won't generate any warnings, use it. */
4117 if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr)
4118 || ((TREE_CODE (ttr) == FUNCTION_TYPE
4119 && TREE_CODE (ttl) == FUNCTION_TYPE)
4120 ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4121 == TYPE_QUALS (ttr))
4122 : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr))
4123 == TYPE_QUALS (ttl))))
4126 /* Keep looking for a better type, but remember this one. */
4127 if (! marginal_memb_type)
4128 marginal_memb_type = memb_type;
4132 /* Can convert integer zero to any pointer type. */
4133 if (integer_zerop (rhs)
4134 || (TREE_CODE (rhs) == NOP_EXPR
4135 && integer_zerop (TREE_OPERAND (rhs, 0))))
4137 rhs = null_pointer_node;
4142 if (memb_types || marginal_memb_type)
4146 /* We have only a marginally acceptable member type;
4147 it needs a warning. */
4148 tree ttl = TREE_TYPE (marginal_memb_type);
4149 tree ttr = TREE_TYPE (rhstype);
4151 /* Const and volatile mean something different for function
4152 types, so the usual warnings are not appropriate. */
4153 if (TREE_CODE (ttr) == FUNCTION_TYPE
4154 && TREE_CODE (ttl) == FUNCTION_TYPE)
4156 /* Because const and volatile on functions are
4157 restrictions that say the function will not do
4158 certain things, it is okay to use a const or volatile
4159 function where an ordinary one is wanted, but not
4161 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4162 warn_for_assignment ("%s makes qualified function pointer from unqualified",
4163 errtype, funname, parmnum);
4165 else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4166 warn_for_assignment ("%s discards qualifiers from pointer target type",
4171 if (pedantic && ! DECL_IN_SYSTEM_HEADER (fundecl))
4172 pedwarn ("ISO C prohibits argument conversion to union type");
4174 return build1 (NOP_EXPR, type, rhs);
4178 /* Conversions among pointers */
4179 else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4180 && (coder == codel))
4182 tree ttl = TREE_TYPE (type);
4183 tree ttr = TREE_TYPE (rhstype);
4185 /* Any non-function converts to a [const][volatile] void *
4186 and vice versa; otherwise, targets must be the same.
4187 Meanwhile, the lhs target must have all the qualifiers of the rhs. */
4188 if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4189 || comp_target_types (type, rhstype, 0)
4190 || (c_common_unsigned_type (TYPE_MAIN_VARIANT (ttl))
4191 == c_common_unsigned_type (TYPE_MAIN_VARIANT (ttr))))
4194 && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE)
4197 /* Check TREE_CODE to catch cases like (void *) (char *) 0
4198 which are not ANSI null ptr constants. */
4199 && (!integer_zerop (rhs) || TREE_CODE (rhs) == NOP_EXPR)
4200 && TREE_CODE (ttl) == FUNCTION_TYPE)))
4201 warn_for_assignment ("ISO C forbids %s between function pointer and `void *'",
4202 errtype, funname, parmnum);
4203 /* Const and volatile mean something different for function types,
4204 so the usual warnings are not appropriate. */
4205 else if (TREE_CODE (ttr) != FUNCTION_TYPE
4206 && TREE_CODE (ttl) != FUNCTION_TYPE)
4208 if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl))
4209 warn_for_assignment ("%s discards qualifiers from pointer target type",
4210 errtype, funname, parmnum);
4211 /* If this is not a case of ignoring a mismatch in signedness,
4213 else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr)
4214 || comp_target_types (type, rhstype, 0))
4216 /* If there is a mismatch, do warn. */
4218 warn_for_assignment ("pointer targets in %s differ in signedness",
4219 errtype, funname, parmnum);
4221 else if (TREE_CODE (ttl) == FUNCTION_TYPE
4222 && TREE_CODE (ttr) == FUNCTION_TYPE)
4224 /* Because const and volatile on functions are restrictions
4225 that say the function will not do certain things,
4226 it is okay to use a const or volatile function
4227 where an ordinary one is wanted, but not vice-versa. */
4228 if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr))
4229 warn_for_assignment ("%s makes qualified function pointer from unqualified",
4230 errtype, funname, parmnum);
4234 warn_for_assignment ("%s from incompatible pointer type",
4235 errtype, funname, parmnum);
4236 return convert (type, rhs);
4238 else if (codel == POINTER_TYPE && coder == INTEGER_TYPE)
4240 /* An explicit constant 0 can convert to a pointer,
4241 or one that results from arithmetic, even including
4242 a cast to integer type. */
4243 if (! (TREE_CODE (rhs) == INTEGER_CST && integer_zerop (rhs))
4245 ! (TREE_CODE (rhs) == NOP_EXPR
4246 && TREE_CODE (TREE_TYPE (rhs)) == INTEGER_TYPE
4247 && TREE_CODE (TREE_OPERAND (rhs, 0)) == INTEGER_CST
4248 && integer_zerop (TREE_OPERAND (rhs, 0))))
4250 warn_for_assignment ("%s makes pointer from integer without a cast",
4251 errtype, funname, parmnum);
4252 return convert (type, rhs);
4254 return null_pointer_node;
4256 else if (codel == INTEGER_TYPE && coder == POINTER_TYPE)
4258 warn_for_assignment ("%s makes integer from pointer without a cast",
4259 errtype, funname, parmnum);
4260 return convert (type, rhs);
4262 else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE)
4263 return convert (type, rhs);
4269 tree selector = objc_message_selector ();
4271 if (selector && parmnum > 2)
4272 error ("incompatible type for argument %d of `%s'",
4273 parmnum - 2, IDENTIFIER_POINTER (selector));
4275 error ("incompatible type for argument %d of `%s'",
4276 parmnum, IDENTIFIER_POINTER (funname));
4279 error ("incompatible type for argument %d of indirect function call",
4283 error ("incompatible types in %s", errtype);
4285 return error_mark_node;
4288 /* Convert VALUE for assignment into inlined parameter PARM. */
4291 c_convert_parm_for_inlining (parm, value, fn)
4292 tree parm, value, fn;
4296 /* If FN was prototyped, the value has been converted already
4297 in convert_arguments. */
4298 if (! value || TYPE_ARG_TYPES (TREE_TYPE (fn)))
4301 type = TREE_TYPE (parm);
4302 ret = convert_for_assignment (type, value,
4303 (char *) 0 /* arg passing */, fn,
4305 if (PROMOTE_PROTOTYPES
4306 && INTEGRAL_TYPE_P (type)
4307 && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node)))
4308 ret = default_conversion (ret);
4312 /* Print a warning using MSGID.
4313 It gets OPNAME as its one parameter.
4314 if OPNAME is null and ARGNUM is 0, it is replaced by "passing arg of `FUNCTION'".
4315 Otherwise if OPNAME is null, it is replaced by "passing arg ARGNUM of `FUNCTION'".
4316 FUNCTION and ARGNUM are handled specially if we are building an
4317 Objective-C selector. */
4320 warn_for_assignment (msgid, opname, function, argnum)
4328 tree selector = objc_message_selector ();
4331 if (selector && argnum > 2)
4333 function = selector;
4340 /* Function name is known; supply it. */
4341 const char *const argstring = _("passing arg of `%s'");
4342 new_opname = (char *) alloca (IDENTIFIER_LENGTH (function)
4343 + strlen (argstring) + 1
4345 sprintf (new_opname, argstring,
4346 IDENTIFIER_POINTER (function));
4350 /* Function name unknown (call through ptr). */
4351 const char *const argnofun = _("passing arg of pointer to function");
4352 new_opname = (char *) alloca (strlen (argnofun) + 1 + 1);
4353 sprintf (new_opname, argnofun);
4358 /* Function name is known; supply it. */
4359 const char *const argstring = _("passing arg %d of `%s'");
4360 new_opname = (char *) alloca (IDENTIFIER_LENGTH (function)
4361 + strlen (argstring) + 1 + 25
4363 sprintf (new_opname, argstring, argnum,
4364 IDENTIFIER_POINTER (function));
4368 /* Function name unknown (call through ptr); just give arg number. */
4369 const char *const argnofun = _("passing arg %d of pointer to function");
4370 new_opname = (char *) alloca (strlen (argnofun) + 1 + 25 /*%d*/ + 1);
4371 sprintf (new_opname, argnofun, argnum);
4373 opname = new_opname;
4375 pedwarn (msgid, opname);
4378 /* If VALUE is a compound expr all of whose expressions are constant, then
4379 return its value. Otherwise, return error_mark_node.
4381 This is for handling COMPOUND_EXPRs as initializer elements
4382 which is allowed with a warning when -pedantic is specified. */
4385 valid_compound_expr_initializer (value, endtype)
4389 if (TREE_CODE (value) == COMPOUND_EXPR)
4391 if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype)
4393 return error_mark_node;
4394 return valid_compound_expr_initializer (TREE_OPERAND (value, 1),
4397 else if (! TREE_CONSTANT (value)
4398 && ! initializer_constant_valid_p (value, endtype))
4399 return error_mark_node;
4404 /* Perform appropriate conversions on the initial value of a variable,
4405 store it in the declaration DECL,
4406 and print any error messages that are appropriate.
4407 If the init is invalid, store an ERROR_MARK. */
4410 store_init_value (decl, init)
4415 /* If variable's type was invalidly declared, just ignore it. */
4417 type = TREE_TYPE (decl);
4418 if (TREE_CODE (type) == ERROR_MARK)
4421 /* Digest the specified initializer into an expression. */
4423 value = digest_init (type, init, TREE_STATIC (decl));
4425 /* Store the expression if valid; else report error. */
4428 /* Note that this is the only place we can detect the error
4429 in a case such as struct foo bar = (struct foo) { x, y };
4430 where there is one initial value which is a constructor expression. */
4431 if (value == error_mark_node)
4433 else if (TREE_STATIC (decl) && ! TREE_CONSTANT (value))
4435 error ("initializer for static variable is not constant");
4436 value = error_mark_node;
4438 else if (TREE_STATIC (decl)
4439 && initializer_constant_valid_p (value, TREE_TYPE (value)) == 0)
4441 error ("initializer for static variable uses complicated arithmetic");
4442 value = error_mark_node;
4446 if (pedantic && TREE_CODE (value) == CONSTRUCTOR)
4448 if (! TREE_CONSTANT (value))
4449 pedwarn ("aggregate initializer is not constant");
4450 else if (! TREE_STATIC (value))
4451 pedwarn ("aggregate initializer uses complicated arithmetic");
4456 if (warn_traditional && !in_system_header
4457 && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && ! TREE_STATIC (decl))
4458 warning ("traditional C rejects automatic aggregate initialization");
4460 DECL_INITIAL (decl) = value;
4462 /* ANSI wants warnings about out-of-range constant initializers. */
4463 STRIP_TYPE_NOPS (value);
4464 constant_expression_warning (value);
4466 /* Check if we need to set array size from compound literal size. */
4467 if (TREE_CODE (type) == ARRAY_TYPE
4468 && TYPE_DOMAIN (type) == 0
4469 && value != error_mark_node)
4471 tree inside_init = init;
4473 if (TREE_CODE (init) == NON_LVALUE_EXPR)
4474 inside_init = TREE_OPERAND (init, 0);
4475 inside_init = fold (inside_init);
4477 if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4479 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4481 if (TYPE_DOMAIN (TREE_TYPE (decl)))
4483 /* For int foo[] = (int [3]){1}; we need to set array size
4484 now since later on array initializer will be just the
4485 brace enclosed list of the compound literal. */
4486 TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (decl));
4488 layout_decl (decl, 0);
4494 /* Methods for storing and printing names for error messages. */
4496 /* Implement a spelling stack that allows components of a name to be pushed
4497 and popped. Each element on the stack is this structure. */
4509 #define SPELLING_STRING 1
4510 #define SPELLING_MEMBER 2
4511 #define SPELLING_BOUNDS 3
4513 static struct spelling *spelling; /* Next stack element (unused). */
4514 static struct spelling *spelling_base; /* Spelling stack base. */
4515 static int spelling_size; /* Size of the spelling stack. */
4517 /* Macros to save and restore the spelling stack around push_... functions.
4518 Alternative to SAVE_SPELLING_STACK. */
4520 #define SPELLING_DEPTH() (spelling - spelling_base)
4521 #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH))
4523 /* Push an element on the spelling stack with type KIND and assign VALUE
4526 #define PUSH_SPELLING(KIND, VALUE, MEMBER) \
4528 int depth = SPELLING_DEPTH (); \
4530 if (depth >= spelling_size) \
4532 spelling_size += 10; \
4533 if (spelling_base == 0) \
4535 = (struct spelling *) xmalloc (spelling_size * sizeof (struct spelling)); \
4538 = (struct spelling *) xrealloc (spelling_base, \
4539 spelling_size * sizeof (struct spelling)); \
4540 RESTORE_SPELLING_DEPTH (depth); \
4543 spelling->kind = (KIND); \
4544 spelling->MEMBER = (VALUE); \
4548 /* Push STRING on the stack. Printed literally. */
4551 push_string (string)
4554 PUSH_SPELLING (SPELLING_STRING, string, u.s);
4557 /* Push a member name on the stack. Printed as '.' STRING. */
4560 push_member_name (decl)
4564 const char *const string
4565 = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : "<anonymous>";
4566 PUSH_SPELLING (SPELLING_MEMBER, string, u.s);
4569 /* Push an array bounds on the stack. Printed as [BOUNDS]. */
4572 push_array_bounds (bounds)
4575 PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i);
4578 /* Compute the maximum size in bytes of the printed spelling. */
4586 for (p = spelling_base; p < spelling; p++)
4588 if (p->kind == SPELLING_BOUNDS)
4591 size += strlen (p->u.s) + 1;
4597 /* Print the spelling to BUFFER and return it. */
4600 print_spelling (buffer)
4606 for (p = spelling_base; p < spelling; p++)
4607 if (p->kind == SPELLING_BOUNDS)
4609 sprintf (d, "[%d]", p->u.i);
4615 if (p->kind == SPELLING_MEMBER)
4617 for (s = p->u.s; (*d = *s++); d++)
4624 /* Issue an error message for a bad initializer component.
4625 MSGID identifies the message.
4626 The component name is taken from the spelling stack. */
4634 error ("%s", _(msgid));
4635 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4637 error ("(near initialization for `%s')", ofwhat);
4640 /* Issue a pedantic warning for a bad initializer component.
4641 MSGID identifies the message.
4642 The component name is taken from the spelling stack. */
4645 pedwarn_init (msgid)
4650 pedwarn ("%s", _(msgid));
4651 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4653 pedwarn ("(near initialization for `%s')", ofwhat);
4656 /* Issue a warning for a bad initializer component.
4657 MSGID identifies the message.
4658 The component name is taken from the spelling stack. */
4661 warning_init (msgid)
4666 warning ("%s", _(msgid));
4667 ofwhat = print_spelling ((char *) alloca (spelling_length () + 1));
4669 warning ("(near initialization for `%s')", ofwhat);
4672 /* Digest the parser output INIT as an initializer for type TYPE.
4673 Return a C expression of type TYPE to represent the initial value.
4675 REQUIRE_CONSTANT requests an error if non-constant initializers or
4676 elements are seen. */
4679 digest_init (type, init, require_constant)
4681 int require_constant;
4683 enum tree_code code = TREE_CODE (type);
4684 tree inside_init = init;
4686 if (type == error_mark_node
4687 || init == error_mark_node
4688 || TREE_TYPE (init) == error_mark_node)
4689 return error_mark_node;
4691 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue. */
4692 /* Do not use STRIP_NOPS here. We do not want an enumerator
4693 whose value is 0 to count as a null pointer constant. */
4694 if (TREE_CODE (init) == NON_LVALUE_EXPR)
4695 inside_init = TREE_OPERAND (init, 0);
4697 inside_init = fold (inside_init);
4699 /* Initialization of an array of chars from a string constant
4700 optionally enclosed in braces. */
4702 if (code == ARRAY_TYPE)
4704 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
4705 if ((typ1 == char_type_node
4706 || typ1 == signed_char_type_node
4707 || typ1 == unsigned_char_type_node
4708 || typ1 == unsigned_wchar_type_node
4709 || typ1 == signed_wchar_type_node)
4710 && ((inside_init && TREE_CODE (inside_init) == STRING_CST)))
4712 if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4713 TYPE_MAIN_VARIANT (type)))
4716 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4718 && TYPE_PRECISION (typ1) == TYPE_PRECISION (char_type_node))
4720 error_init ("char-array initialized from wide string");
4721 return error_mark_node;
4723 if ((TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init)))
4725 && TYPE_PRECISION (typ1) != TYPE_PRECISION (char_type_node))
4727 error_init ("int-array initialized from non-wide string");
4728 return error_mark_node;
4731 TREE_TYPE (inside_init) = type;
4732 if (TYPE_DOMAIN (type) != 0
4733 && TYPE_SIZE (type) != 0
4734 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST
4735 /* Subtract 1 (or sizeof (wchar_t))
4736 because it's ok to ignore the terminating null char
4737 that is counted in the length of the constant. */
4738 && 0 > compare_tree_int (TYPE_SIZE_UNIT (type),
4739 TREE_STRING_LENGTH (inside_init)
4740 - ((TYPE_PRECISION (typ1)
4741 != TYPE_PRECISION (char_type_node))
4742 ? (TYPE_PRECISION (wchar_type_node)
4745 pedwarn_init ("initializer-string for array of chars is too long");
4751 /* Any type can be initialized
4752 from an expression of the same type, optionally with braces. */
4754 if (inside_init && TREE_TYPE (inside_init) != 0
4755 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)),
4756 TYPE_MAIN_VARIANT (type))
4757 || (code == ARRAY_TYPE
4758 && comptypes (TREE_TYPE (inside_init), type))
4759 || (code == VECTOR_TYPE
4760 && comptypes (TREE_TYPE (inside_init), type))
4761 || (code == POINTER_TYPE
4762 && (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE
4763 || TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE)
4764 && comptypes (TREE_TYPE (TREE_TYPE (inside_init)),
4765 TREE_TYPE (type)))))
4767 if (code == POINTER_TYPE)
4768 inside_init = default_function_array_conversion (inside_init);
4770 if (require_constant && !flag_isoc99
4771 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR)
4773 /* As an extension, allow initializing objects with static storage
4774 duration with compound literals (which are then treated just as
4775 the brace enclosed list they contain). */
4776 tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init);
4777 inside_init = DECL_INITIAL (decl);
4780 if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST
4781 && TREE_CODE (inside_init) != CONSTRUCTOR)
4783 error_init ("array initialized from non-constant array expression");
4784 return error_mark_node;
4787 if (optimize && TREE_CODE (inside_init) == VAR_DECL)
4788 inside_init = decl_constant_value_for_broken_optimization (inside_init);
4790 /* Compound expressions can only occur here if -pedantic or
4791 -pedantic-errors is specified. In the later case, we always want
4792 an error. In the former case, we simply want a warning. */
4793 if (require_constant && pedantic
4794 && TREE_CODE (inside_init) == COMPOUND_EXPR)
4797 = valid_compound_expr_initializer (inside_init,
4798 TREE_TYPE (inside_init));
4799 if (inside_init == error_mark_node)
4800 error_init ("initializer element is not constant");
4802 pedwarn_init ("initializer element is not constant");
4803 if (flag_pedantic_errors)
4804 inside_init = error_mark_node;
4806 else if (require_constant
4807 && (!TREE_CONSTANT (inside_init)
4808 /* This test catches things like `7 / 0' which
4809 result in an expression for which TREE_CONSTANT
4810 is true, but which is not actually something
4811 that is a legal constant. We really should not
4812 be using this function, because it is a part of
4813 the back-end. Instead, the expression should
4814 already have been turned into ERROR_MARK_NODE. */
4815 || !initializer_constant_valid_p (inside_init,
4816 TREE_TYPE (inside_init))))
4818 error_init ("initializer element is not constant");
4819 inside_init = error_mark_node;
4825 /* Handle scalar types, including conversions. */
4827 if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE
4828 || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE)
4830 /* Note that convert_for_assignment calls default_conversion
4831 for arrays and functions. We must not call it in the
4832 case where inside_init is a null pointer constant. */
4834 = convert_for_assignment (type, init, _("initialization"),
4835 NULL_TREE, NULL_TREE, 0);
4837 if (require_constant && ! TREE_CONSTANT (inside_init))
4839 error_init ("initializer element is not constant");
4840 inside_init = error_mark_node;
4842 else if (require_constant
4843 && initializer_constant_valid_p (inside_init, TREE_TYPE (inside_init)) == 0)
4845 error_init ("initializer element is not computable at load time");
4846 inside_init = error_mark_node;
4852 /* Come here only for records and arrays. */
4854 if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4856 error_init ("variable-sized object may not be initialized");
4857 return error_mark_node;
4860 error_init ("invalid initializer");
4861 return error_mark_node;
4864 /* Handle initializers that use braces. */
4866 /* Type of object we are accumulating a constructor for.
4867 This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */
4868 static tree constructor_type;
4870 /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields
4872 static tree constructor_fields;
4874 /* For an ARRAY_TYPE, this is the specified index
4875 at which to store the next element we get. */
4876 static tree constructor_index;
4878 /* For an ARRAY_TYPE, this is the maximum index. */
4879 static tree constructor_max_index;
4881 /* For a RECORD_TYPE, this is the first field not yet written out. */
4882 static tree constructor_unfilled_fields;
4884 /* For an ARRAY_TYPE, this is the index of the first element
4885 not yet written out. */
4886 static tree constructor_unfilled_index;
4888 /* In a RECORD_TYPE, the byte index of the next consecutive field.
4889 This is so we can generate gaps between fields, when appropriate. */
4890 static tree constructor_bit_index;
4892 /* If we are saving up the elements rather than allocating them,
4893 this is the list of elements so far (in reverse order,
4894 most recent first). */
4895 static tree constructor_elements;
4897 /* 1 if constructor should be incrementally stored into a constructor chain,
4898 0 if all the elements should be kept in AVL tree. */
4899 static int constructor_incremental;
4901 /* 1 if so far this constructor's elements are all compile-time constants. */
4902 static int constructor_constant;
4904 /* 1 if so far this constructor's elements are all valid address constants. */
4905 static int constructor_simple;
4907 /* 1 if this constructor is erroneous so far. */
4908 static int constructor_erroneous;
4910 /* 1 if have called defer_addressed_constants. */
4911 static int constructor_subconstants_deferred;
4913 /* Structure for managing pending initializer elements, organized as an
4918 struct init_node *left, *right;
4919 struct init_node *parent;
4925 /* Tree of pending elements at this constructor level.
4926 These are elements encountered out of order
4927 which belong at places we haven't reached yet in actually
4929 Will never hold tree nodes across GC runs. */
4930 static struct init_node *constructor_pending_elts;
4932 /* The SPELLING_DEPTH of this constructor. */
4933 static int constructor_depth;
4935 /* 0 if implicitly pushing constructor levels is allowed. */
4936 int constructor_no_implicit = 0; /* 0 for C; 1 for some other languages. */
4938 static int require_constant_value;
4939 static int require_constant_elements;
4941 /* DECL node for which an initializer is being read.
4942 0 means we are reading a constructor expression
4943 such as (struct foo) {...}. */
4944 static tree constructor_decl;
4946 /* start_init saves the ASMSPEC arg here for really_start_incremental_init. */
4947 static const char *constructor_asmspec;
4949 /* Nonzero if this is an initializer for a top-level decl. */
4950 static int constructor_top_level;
4952 /* Nonzero if there were any member designators in this initializer. */
4953 static int constructor_designated;
4955 /* Nesting depth of designator list. */
4956 static int designator_depth;
4958 /* Nonzero if there were diagnosed errors in this designator list. */
4959 static int designator_errorneous;
4962 /* This stack has a level for each implicit or explicit level of
4963 structuring in the initializer, including the outermost one. It
4964 saves the values of most of the variables above. */
4966 struct constructor_range_stack;
4968 struct constructor_stack
4970 struct constructor_stack *next;
4975 tree unfilled_index;
4976 tree unfilled_fields;
4979 struct init_node *pending_elts;
4982 /* If nonzero, this value should replace the entire
4983 constructor at this level. */
4984 tree replacement_value;
4985 struct constructor_range_stack *range_stack;
4995 struct constructor_stack *constructor_stack;
4997 /* This stack represents designators from some range designator up to
4998 the last designator in the list. */
5000 struct constructor_range_stack
5002 struct constructor_range_stack *next, *prev;
5003 struct constructor_stack *stack;
5010 struct constructor_range_stack *constructor_range_stack;
5012 /* This stack records separate initializers that are nested.
5013 Nested initializers can't happen in ANSI C, but GNU C allows them
5014 in cases like { ... (struct foo) { ... } ... }. */
5016 struct initializer_stack
5018 struct initializer_stack *next;
5020 const char *asmspec;
5021 struct constructor_stack *constructor_stack;
5022 struct constructor_range_stack *constructor_range_stack;
5024 struct spelling *spelling;
5025 struct spelling *spelling_base;
5028 char require_constant_value;
5029 char require_constant_elements;
5033 struct initializer_stack *initializer_stack;
5035 /* Prepare to parse and output the initializer for variable DECL. */
5038 start_init (decl, asmspec_tree, top_level)
5044 struct initializer_stack *p
5045 = (struct initializer_stack *) xmalloc (sizeof (struct initializer_stack));
5046 const char *asmspec = 0;
5049 asmspec = TREE_STRING_POINTER (asmspec_tree);
5051 p->decl = constructor_decl;
5052 p->asmspec = constructor_asmspec;
5053 p->require_constant_value = require_constant_value;
5054 p->require_constant_elements = require_constant_elements;
5055 p->constructor_stack = constructor_stack;
5056 p->constructor_range_stack = constructor_range_stack;
5057 p->elements = constructor_elements;
5058 p->spelling = spelling;
5059 p->spelling_base = spelling_base;
5060 p->spelling_size = spelling_size;
5061 p->deferred = constructor_subconstants_deferred;
5062 p->top_level = constructor_top_level;
5063 p->next = initializer_stack;
5064 initializer_stack = p;
5066 constructor_decl = decl;
5067 constructor_asmspec = asmspec;
5068 constructor_subconstants_deferred = 0;
5069 constructor_designated = 0;
5070 constructor_top_level = top_level;
5074 require_constant_value = TREE_STATIC (decl);
5075 require_constant_elements
5076 = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99))
5077 /* For a scalar, you can always use any value to initialize,
5078 even within braces. */
5079 && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
5080 || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE
5081 || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE
5082 || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE));
5083 locus = IDENTIFIER_POINTER (DECL_NAME (decl));
5087 require_constant_value = 0;
5088 require_constant_elements = 0;
5089 locus = "(anonymous)";
5092 constructor_stack = 0;
5093 constructor_range_stack = 0;
5095 missing_braces_mentioned = 0;
5099 RESTORE_SPELLING_DEPTH (0);
5102 push_string (locus);
5108 struct initializer_stack *p = initializer_stack;
5110 /* Output subconstants (string constants, usually)
5111 that were referenced within this initializer and saved up.
5112 Must do this if and only if we called defer_addressed_constants. */
5113 if (constructor_subconstants_deferred)
5114 output_deferred_addressed_constants ();
5116 /* Free the whole constructor stack of this initializer. */
5117 while (constructor_stack)
5119 struct constructor_stack *q = constructor_stack;
5120 constructor_stack = q->next;
5124 if (constructor_range_stack)
5127 /* Pop back to the data of the outer initializer (if any). */
5128 constructor_decl = p->decl;
5129 constructor_asmspec = p->asmspec;
5130 require_constant_value = p->require_constant_value;
5131 require_constant_elements = p->require_constant_elements;
5132 constructor_stack = p->constructor_stack;
5133 constructor_range_stack = p->constructor_range_stack;
5134 constructor_elements = p->elements;
5135 spelling = p->spelling;
5136 spelling_base = p->spelling_base;
5137 spelling_size = p->spelling_size;
5138 constructor_subconstants_deferred = p->deferred;
5139 constructor_top_level = p->top_level;
5140 initializer_stack = p->next;
5144 /* Call here when we see the initializer is surrounded by braces.
5145 This is instead of a call to push_init_level;
5146 it is matched by a call to pop_init_level.
5148 TYPE is the type to initialize, for a constructor expression.
5149 For an initializer for a decl, TYPE is zero. */
5152 really_start_incremental_init (type)
5155 struct constructor_stack *p
5156 = (struct constructor_stack *) xmalloc (sizeof (struct constructor_stack));
5159 type = TREE_TYPE (constructor_decl);
5161 p->type = constructor_type;
5162 p->fields = constructor_fields;
5163 p->index = constructor_index;
5164 p->max_index = constructor_max_index;
5165 p->unfilled_index = constructor_unfilled_index;
5166 p->unfilled_fields = constructor_unfilled_fields;
5167 p->bit_index = constructor_bit_index;
5168 p->elements = constructor_elements;
5169 p->constant = constructor_constant;
5170 p->simple = constructor_simple;
5171 p->erroneous = constructor_erroneous;
5172 p->pending_elts = constructor_pending_elts;
5173 p->depth = constructor_depth;
5174 p->replacement_value = 0;
5178 p->incremental = constructor_incremental;
5179 p->designated = constructor_designated;
5181 constructor_stack = p;
5183 constructor_constant = 1;
5184 constructor_simple = 1;
5185 constructor_depth = SPELLING_DEPTH ();
5186 constructor_elements = 0;
5187 constructor_pending_elts = 0;
5188 constructor_type = type;
5189 constructor_incremental = 1;
5190 constructor_designated = 0;
5191 designator_depth = 0;
5192 designator_errorneous = 0;
5194 if (TREE_CODE (constructor_type) == RECORD_TYPE
5195 || TREE_CODE (constructor_type) == UNION_TYPE)
5197 constructor_fields = TYPE_FIELDS (constructor_type);
5198 /* Skip any nameless bit fields at the beginning. */
5199 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5200 && DECL_NAME (constructor_fields) == 0)
5201 constructor_fields = TREE_CHAIN (constructor_fields);
5203 constructor_unfilled_fields = constructor_fields;
5204 constructor_bit_index = bitsize_zero_node;
5206 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5208 if (TYPE_DOMAIN (constructor_type))
5210 constructor_max_index
5211 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5213 /* Detect non-empty initializations of zero-length arrays. */
5214 if (constructor_max_index == NULL_TREE
5215 && TYPE_SIZE (constructor_type))
5216 constructor_max_index = build_int_2 (-1, -1);
5218 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5219 to initialize VLAs will cause a proper error; avoid tree
5220 checking errors as well by setting a safe value. */
5221 if (constructor_max_index
5222 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5223 constructor_max_index = build_int_2 (-1, -1);
5226 = convert (bitsizetype,
5227 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5230 constructor_index = bitsize_zero_node;
5232 constructor_unfilled_index = constructor_index;
5234 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5236 /* Vectors are like simple fixed-size arrays. */
5237 constructor_max_index =
5238 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0);
5239 constructor_index = convert (bitsizetype, bitsize_zero_node);
5240 constructor_unfilled_index = constructor_index;
5244 /* Handle the case of int x = {5}; */
5245 constructor_fields = constructor_type;
5246 constructor_unfilled_fields = constructor_type;
5250 /* Push down into a subobject, for initialization.
5251 If this is for an explicit set of braces, IMPLICIT is 0.
5252 If it is because the next element belongs at a lower level,
5253 IMPLICIT is 1 (or 2 if the push is because of designator list). */
5256 push_init_level (implicit)
5259 struct constructor_stack *p;
5260 tree value = NULL_TREE;
5262 /* If we've exhausted any levels that didn't have braces,
5264 while (constructor_stack->implicit)
5266 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5267 || TREE_CODE (constructor_type) == UNION_TYPE)
5268 && constructor_fields == 0)
5269 process_init_element (pop_init_level (1));
5270 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
5271 && tree_int_cst_lt (constructor_max_index, constructor_index))
5272 process_init_element (pop_init_level (1));
5277 /* Unless this is an explicit brace, we need to preserve previous
5281 if ((TREE_CODE (constructor_type) == RECORD_TYPE
5282 || TREE_CODE (constructor_type) == UNION_TYPE)
5283 && constructor_fields)
5284 value = find_init_member (constructor_fields);
5285 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5286 value = find_init_member (constructor_index);
5289 p = (struct constructor_stack *) xmalloc (sizeof (struct constructor_stack));
5290 p->type = constructor_type;
5291 p->fields = constructor_fields;
5292 p->index = constructor_index;
5293 p->max_index = constructor_max_index;
5294 p->unfilled_index = constructor_unfilled_index;
5295 p->unfilled_fields = constructor_unfilled_fields;
5296 p->bit_index = constructor_bit_index;
5297 p->elements = constructor_elements;
5298 p->constant = constructor_constant;
5299 p->simple = constructor_simple;
5300 p->erroneous = constructor_erroneous;
5301 p->pending_elts = constructor_pending_elts;
5302 p->depth = constructor_depth;
5303 p->replacement_value = 0;
5304 p->implicit = implicit;
5306 p->incremental = constructor_incremental;
5307 p->designated = constructor_designated;
5308 p->next = constructor_stack;
5310 constructor_stack = p;
5312 constructor_constant = 1;
5313 constructor_simple = 1;
5314 constructor_depth = SPELLING_DEPTH ();
5315 constructor_elements = 0;
5316 constructor_incremental = 1;
5317 constructor_designated = 0;
5318 constructor_pending_elts = 0;
5321 p->range_stack = constructor_range_stack;
5322 constructor_range_stack = 0;
5323 designator_depth = 0;
5324 designator_errorneous = 0;
5327 /* Don't die if an entire brace-pair level is superfluous
5328 in the containing level. */
5329 if (constructor_type == 0)
5331 else if (TREE_CODE (constructor_type) == RECORD_TYPE
5332 || TREE_CODE (constructor_type) == UNION_TYPE)
5334 /* Don't die if there are extra init elts at the end. */
5335 if (constructor_fields == 0)
5336 constructor_type = 0;
5339 constructor_type = TREE_TYPE (constructor_fields);
5340 push_member_name (constructor_fields);
5341 constructor_depth++;
5344 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5346 constructor_type = TREE_TYPE (constructor_type);
5347 push_array_bounds (tree_low_cst (constructor_index, 0));
5348 constructor_depth++;
5351 if (constructor_type == 0)
5353 error_init ("extra brace group at end of initializer");
5354 constructor_fields = 0;
5355 constructor_unfilled_fields = 0;
5359 if (value && TREE_CODE (value) == CONSTRUCTOR)
5361 constructor_constant = TREE_CONSTANT (value);
5362 constructor_simple = TREE_STATIC (value);
5363 constructor_elements = TREE_OPERAND (value, 1);
5364 if (constructor_elements
5365 && (TREE_CODE (constructor_type) == RECORD_TYPE
5366 || TREE_CODE (constructor_type) == ARRAY_TYPE))
5367 set_nonincremental_init ();
5370 if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned)
5372 missing_braces_mentioned = 1;
5373 warning_init ("missing braces around initializer");
5376 if (TREE_CODE (constructor_type) == RECORD_TYPE
5377 || TREE_CODE (constructor_type) == UNION_TYPE)
5379 constructor_fields = TYPE_FIELDS (constructor_type);
5380 /* Skip any nameless bit fields at the beginning. */
5381 while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields)
5382 && DECL_NAME (constructor_fields) == 0)
5383 constructor_fields = TREE_CHAIN (constructor_fields);
5385 constructor_unfilled_fields = constructor_fields;
5386 constructor_bit_index = bitsize_zero_node;
5388 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
5390 /* Vectors are like simple fixed-size arrays. */
5391 constructor_max_index =
5392 build_int_2 (TYPE_VECTOR_SUBPARTS (constructor_type) - 1, 0);
5393 constructor_index = convert (bitsizetype, integer_zero_node);
5394 constructor_unfilled_index = constructor_index;
5396 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5398 if (TYPE_DOMAIN (constructor_type))
5400 constructor_max_index
5401 = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type));
5403 /* Detect non-empty initializations of zero-length arrays. */
5404 if (constructor_max_index == NULL_TREE
5405 && TYPE_SIZE (constructor_type))
5406 constructor_max_index = build_int_2 (-1, -1);
5408 /* constructor_max_index needs to be an INTEGER_CST. Attempts
5409 to initialize VLAs will cause a proper error; avoid tree
5410 checking errors as well by setting a safe value. */
5411 if (constructor_max_index
5412 && TREE_CODE (constructor_max_index) != INTEGER_CST)
5413 constructor_max_index = build_int_2 (-1, -1);
5416 = convert (bitsizetype,
5417 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
5420 constructor_index = bitsize_zero_node;
5422 constructor_unfilled_index = constructor_index;
5423 if (value && TREE_CODE (value) == STRING_CST)
5425 /* We need to split the char/wchar array into individual
5426 characters, so that we don't have to special case it
5428 set_nonincremental_init_from_string (value);
5433 warning_init ("braces around scalar initializer");
5434 constructor_fields = constructor_type;
5435 constructor_unfilled_fields = constructor_type;
5439 /* At the end of an implicit or explicit brace level,
5440 finish up that level of constructor.
5441 If we were outputting the elements as they are read, return 0
5442 from inner levels (process_init_element ignores that),
5443 but return error_mark_node from the outermost level
5444 (that's what we want to put in DECL_INITIAL).
5445 Otherwise, return a CONSTRUCTOR expression. */
5448 pop_init_level (implicit)
5451 struct constructor_stack *p;
5452 tree constructor = 0;
5456 /* When we come to an explicit close brace,
5457 pop any inner levels that didn't have explicit braces. */
5458 while (constructor_stack->implicit)
5459 process_init_element (pop_init_level (1));
5461 if (constructor_range_stack)
5465 p = constructor_stack;
5467 /* Error for initializing a flexible array member, or a zero-length
5468 array member in an inappropriate context. */
5469 if (constructor_type && constructor_fields
5470 && TREE_CODE (constructor_type) == ARRAY_TYPE
5471 && TYPE_DOMAIN (constructor_type)
5472 && ! TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)))
5474 /* Silently discard empty initializations. The parser will
5475 already have pedwarned for empty brackets. */
5476 if (integer_zerop (constructor_unfilled_index))
5477 constructor_type = NULL_TREE;
5478 else if (! TYPE_SIZE (constructor_type))
5480 if (constructor_depth > 2)
5481 error_init ("initialization of flexible array member in a nested context");
5483 pedwarn_init ("initialization of a flexible array member");
5485 /* We have already issued an error message for the existence
5486 of a flexible array member not at the end of the structure.
5487 Discard the initializer so that we do not abort later. */
5488 if (TREE_CHAIN (constructor_fields) != NULL_TREE)
5489 constructor_type = NULL_TREE;
5492 /* Zero-length arrays are no longer special, so we should no longer
5497 /* Warn when some struct elements are implicitly initialized to zero. */
5500 && TREE_CODE (constructor_type) == RECORD_TYPE
5501 && constructor_unfilled_fields)
5503 /* Do not warn for flexible array members or zero-length arrays. */
5504 while (constructor_unfilled_fields
5505 && (! DECL_SIZE (constructor_unfilled_fields)
5506 || integer_zerop (DECL_SIZE (constructor_unfilled_fields))))
5507 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
5509 /* Do not warn if this level of the initializer uses member
5510 designators; it is likely to be deliberate. */
5511 if (constructor_unfilled_fields && !constructor_designated)
5513 push_member_name (constructor_unfilled_fields);
5514 warning_init ("missing initializer");
5515 RESTORE_SPELLING_DEPTH (constructor_depth);
5519 /* Now output all pending elements. */
5520 constructor_incremental = 1;
5521 output_pending_init_elements (1);
5523 /* Pad out the end of the structure. */
5524 if (p->replacement_value)
5525 /* If this closes a superfluous brace pair,
5526 just pass out the element between them. */
5527 constructor = p->replacement_value;
5528 else if (constructor_type == 0)
5530 else if (TREE_CODE (constructor_type) != RECORD_TYPE
5531 && TREE_CODE (constructor_type) != UNION_TYPE
5532 && TREE_CODE (constructor_type) != ARRAY_TYPE
5533 && TREE_CODE (constructor_type) != VECTOR_TYPE)
5535 /* A nonincremental scalar initializer--just return
5536 the element, after verifying there is just one. */
5537 if (constructor_elements == 0)
5539 if (!constructor_erroneous)
5540 error_init ("empty scalar initializer");
5541 constructor = error_mark_node;
5543 else if (TREE_CHAIN (constructor_elements) != 0)
5545 error_init ("extra elements in scalar initializer");
5546 constructor = TREE_VALUE (constructor_elements);
5549 constructor = TREE_VALUE (constructor_elements);
5553 if (constructor_erroneous)
5554 constructor = error_mark_node;
5557 constructor = build (CONSTRUCTOR, constructor_type, NULL_TREE,
5558 nreverse (constructor_elements));
5559 if (constructor_constant)
5560 TREE_CONSTANT (constructor) = 1;
5561 if (constructor_constant && constructor_simple)
5562 TREE_STATIC (constructor) = 1;
5566 constructor_type = p->type;
5567 constructor_fields = p->fields;
5568 constructor_index = p->index;
5569 constructor_max_index = p->max_index;
5570 constructor_unfilled_index = p->unfilled_index;
5571 constructor_unfilled_fields = p->unfilled_fields;
5572 constructor_bit_index = p->bit_index;
5573 constructor_elements = p->elements;
5574 constructor_constant = p->constant;
5575 constructor_simple = p->simple;
5576 constructor_erroneous = p->erroneous;
5577 constructor_incremental = p->incremental;
5578 constructor_designated = p->designated;
5579 constructor_pending_elts = p->pending_elts;
5580 constructor_depth = p->depth;
5582 constructor_range_stack = p->range_stack;
5583 RESTORE_SPELLING_DEPTH (constructor_depth);
5585 constructor_stack = p->next;
5588 if (constructor == 0)
5590 if (constructor_stack == 0)
5591 return error_mark_node;
5597 /* Common handling for both array range and field name designators.
5598 ARRAY argument is nonzero for array ranges. Returns zero for success. */
5601 set_designator (array)
5605 enum tree_code subcode;
5607 /* Don't die if an entire brace-pair level is superfluous
5608 in the containing level. */
5609 if (constructor_type == 0)
5612 /* If there were errors in this designator list already, bail out silently. */
5613 if (designator_errorneous)
5616 if (!designator_depth)
5618 if (constructor_range_stack)
5621 /* Designator list starts at the level of closest explicit
5623 while (constructor_stack->implicit)
5624 process_init_element (pop_init_level (1));
5625 constructor_designated = 1;
5629 if (constructor_no_implicit)
5631 error_init ("initialization designators may not nest");
5635 if (TREE_CODE (constructor_type) == RECORD_TYPE
5636 || TREE_CODE (constructor_type) == UNION_TYPE)
5638 subtype = TREE_TYPE (constructor_fields);
5639 if (subtype != error_mark_node)
5640 subtype = TYPE_MAIN_VARIANT (subtype);
5642 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5644 subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
5649 subcode = TREE_CODE (subtype);
5650 if (array && subcode != ARRAY_TYPE)
5652 error_init ("array index in non-array initializer");
5655 else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE)
5657 error_init ("field name not in record or union initializer");
5661 constructor_designated = 1;
5662 push_init_level (2);
5666 /* If there are range designators in designator list, push a new designator
5667 to constructor_range_stack. RANGE_END is end of such stack range or
5668 NULL_TREE if there is no range designator at this level. */
5671 push_range_stack (range_end)
5674 struct constructor_range_stack *p;
5676 p = (struct constructor_range_stack *)
5677 ggc_alloc (sizeof (struct constructor_range_stack));
5678 p->prev = constructor_range_stack;
5680 p->fields = constructor_fields;
5681 p->range_start = constructor_index;
5682 p->index = constructor_index;
5683 p->stack = constructor_stack;
5684 p->range_end = range_end;
5685 if (constructor_range_stack)
5686 constructor_range_stack->next = p;
5687 constructor_range_stack = p;
5690 /* Within an array initializer, specify the next index to be initialized.
5691 FIRST is that index. If LAST is nonzero, then initialize a range
5692 of indices, running from FIRST through LAST. */
5695 set_init_index (first, last)
5698 if (set_designator (1))
5701 designator_errorneous = 1;
5703 while ((TREE_CODE (first) == NOP_EXPR
5704 || TREE_CODE (first) == CONVERT_EXPR
5705 || TREE_CODE (first) == NON_LVALUE_EXPR)
5706 && (TYPE_MODE (TREE_TYPE (first))
5707 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (first, 0)))))
5708 first = TREE_OPERAND (first, 0);
5711 while ((TREE_CODE (last) == NOP_EXPR
5712 || TREE_CODE (last) == CONVERT_EXPR
5713 || TREE_CODE (last) == NON_LVALUE_EXPR)
5714 && (TYPE_MODE (TREE_TYPE (last))
5715 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (last, 0)))))
5716 last = TREE_OPERAND (last, 0);
5718 if (TREE_CODE (first) != INTEGER_CST)
5719 error_init ("nonconstant array index in initializer");
5720 else if (last != 0 && TREE_CODE (last) != INTEGER_CST)
5721 error_init ("nonconstant array index in initializer");
5722 else if (TREE_CODE (constructor_type) != ARRAY_TYPE)
5723 error_init ("array index in non-array initializer");
5724 else if (constructor_max_index
5725 && tree_int_cst_lt (constructor_max_index, first))
5726 error_init ("array index in initializer exceeds array bounds");
5729 constructor_index = convert (bitsizetype, first);
5733 if (tree_int_cst_equal (first, last))
5735 else if (tree_int_cst_lt (last, first))
5737 error_init ("empty index range in initializer");
5742 last = convert (bitsizetype, last);
5743 if (constructor_max_index != 0
5744 && tree_int_cst_lt (constructor_max_index, last))
5746 error_init ("array index range in initializer exceeds array bounds");
5753 designator_errorneous = 0;
5754 if (constructor_range_stack || last)
5755 push_range_stack (last);
5759 /* Within a struct initializer, specify the next field to be initialized. */
5762 set_init_label (fieldname)
5767 if (set_designator (0))
5770 designator_errorneous = 1;
5772 if (TREE_CODE (constructor_type) != RECORD_TYPE
5773 && TREE_CODE (constructor_type) != UNION_TYPE)
5775 error_init ("field name not in record or union initializer");
5779 for (tail = TYPE_FIELDS (constructor_type); tail;
5780 tail = TREE_CHAIN (tail))
5782 if (DECL_NAME (tail) == fieldname)
5787 error ("unknown field `%s' specified in initializer",
5788 IDENTIFIER_POINTER (fieldname));
5791 constructor_fields = tail;
5793 designator_errorneous = 0;
5794 if (constructor_range_stack)
5795 push_range_stack (NULL_TREE);
5799 /* Add a new initializer to the tree of pending initializers. PURPOSE
5800 identifies the initializer, either array index or field in a structure.
5801 VALUE is the value of that index or field. */
5804 add_pending_init (purpose, value)
5805 tree purpose, value;
5807 struct init_node *p, **q, *r;
5809 q = &constructor_pending_elts;
5812 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
5817 if (tree_int_cst_lt (purpose, p->purpose))
5819 else if (tree_int_cst_lt (p->purpose, purpose))
5823 if (TREE_SIDE_EFFECTS (p->value))
5824 warning_init ("initialized field with side-effects overwritten");
5834 bitpos = bit_position (purpose);
5838 if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
5840 else if (p->purpose != purpose)
5844 if (TREE_SIDE_EFFECTS (p->value))
5845 warning_init ("initialized field with side-effects overwritten");
5852 r = (struct init_node *) ggc_alloc (sizeof (struct init_node));
5853 r->purpose = purpose;
5864 struct init_node *s;
5868 if (p->balance == 0)
5870 else if (p->balance < 0)
5877 p->left->parent = p;
5894 constructor_pending_elts = r;
5899 struct init_node *t = r->right;
5903 r->right->parent = r;
5908 p->left->parent = p;
5911 p->balance = t->balance < 0;
5912 r->balance = -(t->balance > 0);
5927 constructor_pending_elts = t;
5933 /* p->balance == +1; growth of left side balances the node. */
5938 else /* r == p->right */
5940 if (p->balance == 0)
5941 /* Growth propagation from right side. */
5943 else if (p->balance > 0)
5950 p->right->parent = p;
5967 constructor_pending_elts = r;
5969 else /* r->balance == -1 */
5972 struct init_node *t = r->left;
5976 r->left->parent = r;
5981 p->right->parent = p;
5984 r->balance = (t->balance < 0);
5985 p->balance = -(t->balance > 0);
6000 constructor_pending_elts = t;
6006 /* p->balance == -1; growth of right side balances the node. */
6017 /* Build AVL tree from a sorted chain. */
6020 set_nonincremental_init ()
6024 if (TREE_CODE (constructor_type) != RECORD_TYPE
6025 && TREE_CODE (constructor_type) != ARRAY_TYPE)
6028 for (chain = constructor_elements; chain; chain = TREE_CHAIN (chain))
6029 add_pending_init (TREE_PURPOSE (chain), TREE_VALUE (chain));
6030 constructor_elements = 0;
6031 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6033 constructor_unfilled_fields = TYPE_FIELDS (constructor_type);
6034 /* Skip any nameless bit fields at the beginning. */
6035 while (constructor_unfilled_fields != 0
6036 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6037 && DECL_NAME (constructor_unfilled_fields) == 0)
6038 constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields);
6041 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6043 if (TYPE_DOMAIN (constructor_type))
6044 constructor_unfilled_index
6045 = convert (bitsizetype,
6046 TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type)));
6048 constructor_unfilled_index = bitsize_zero_node;
6050 constructor_incremental = 0;
6053 /* Build AVL tree from a string constant. */
6056 set_nonincremental_init_from_string (str)
6059 tree value, purpose, type;
6060 HOST_WIDE_INT val[2];
6061 const char *p, *end;
6062 int byte, wchar_bytes, charwidth, bitpos;
6064 if (TREE_CODE (constructor_type) != ARRAY_TYPE)
6067 if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
6068 == TYPE_PRECISION (char_type_node))
6070 else if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str)))
6071 == TYPE_PRECISION (wchar_type_node))
6072 wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT;
6076 charwidth = TYPE_PRECISION (char_type_node);
6077 type = TREE_TYPE (constructor_type);
6078 p = TREE_STRING_POINTER (str);
6079 end = p + TREE_STRING_LENGTH (str);
6081 for (purpose = bitsize_zero_node;
6082 p < end && !tree_int_cst_lt (constructor_max_index, purpose);
6083 purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node))
6085 if (wchar_bytes == 1)
6087 val[1] = (unsigned char) *p++;
6094 for (byte = 0; byte < wchar_bytes; byte++)
6096 if (BYTES_BIG_ENDIAN)
6097 bitpos = (wchar_bytes - byte - 1) * charwidth;
6099 bitpos = byte * charwidth;
6100 val[bitpos < HOST_BITS_PER_WIDE_INT]
6101 |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++))
6102 << (bitpos % HOST_BITS_PER_WIDE_INT);
6106 if (!TREE_UNSIGNED (type))
6108 bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR;
6109 if (bitpos < HOST_BITS_PER_WIDE_INT)
6111 if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1)))
6113 val[1] |= ((HOST_WIDE_INT) -1) << bitpos;
6117 else if (bitpos == HOST_BITS_PER_WIDE_INT)
6122 else if (val[0] & (((HOST_WIDE_INT) 1)
6123 << (bitpos - 1 - HOST_BITS_PER_WIDE_INT)))
6124 val[0] |= ((HOST_WIDE_INT) -1)
6125 << (bitpos - HOST_BITS_PER_WIDE_INT);
6128 value = build_int_2 (val[1], val[0]);
6129 TREE_TYPE (value) = type;
6130 add_pending_init (purpose, value);
6133 constructor_incremental = 0;
6136 /* Return value of FIELD in pending initializer or zero if the field was
6137 not initialized yet. */
6140 find_init_member (field)
6143 struct init_node *p;
6145 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6147 if (constructor_incremental
6148 && tree_int_cst_lt (field, constructor_unfilled_index))
6149 set_nonincremental_init ();
6151 p = constructor_pending_elts;
6154 if (tree_int_cst_lt (field, p->purpose))
6156 else if (tree_int_cst_lt (p->purpose, field))
6162 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6164 tree bitpos = bit_position (field);
6166 if (constructor_incremental
6167 && (!constructor_unfilled_fields
6168 || tree_int_cst_lt (bitpos,
6169 bit_position (constructor_unfilled_fields))))
6170 set_nonincremental_init ();
6172 p = constructor_pending_elts;
6175 if (field == p->purpose)
6177 else if (tree_int_cst_lt (bitpos, bit_position (p->purpose)))
6183 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6185 if (constructor_elements
6186 && TREE_PURPOSE (constructor_elements) == field)
6187 return TREE_VALUE (constructor_elements);
6192 /* "Output" the next constructor element.
6193 At top level, really output it to assembler code now.
6194 Otherwise, collect it in a list from which we will make a CONSTRUCTOR.
6195 TYPE is the data type that the containing data type wants here.
6196 FIELD is the field (a FIELD_DECL) or the index that this element fills.
6198 PENDING if non-nil means output pending elements that belong
6199 right after this element. (PENDING is normally 1;
6200 it is 0 while outputting pending elements, to avoid recursion.) */
6203 output_init_element (value, type, field, pending)
6204 tree value, type, field;
6207 if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE
6208 || (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE
6209 && !(TREE_CODE (value) == STRING_CST
6210 && TREE_CODE (type) == ARRAY_TYPE
6211 && TREE_CODE (TREE_TYPE (type)) == INTEGER_TYPE)
6212 && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)),
6213 TYPE_MAIN_VARIANT (type))))
6214 value = default_conversion (value);
6216 if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR
6217 && require_constant_value && !flag_isoc99 && pending)
6219 /* As an extension, allow initializing objects with static storage
6220 duration with compound literals (which are then treated just as
6221 the brace enclosed list they contain). */
6222 tree decl = COMPOUND_LITERAL_EXPR_DECL (value);
6223 value = DECL_INITIAL (decl);
6226 if (value == error_mark_node)
6227 constructor_erroneous = 1;
6228 else if (!TREE_CONSTANT (value))
6229 constructor_constant = 0;
6230 else if (initializer_constant_valid_p (value, TREE_TYPE (value)) == 0
6231 || ((TREE_CODE (constructor_type) == RECORD_TYPE
6232 || TREE_CODE (constructor_type) == UNION_TYPE)
6233 && DECL_C_BIT_FIELD (field)
6234 && TREE_CODE (value) != INTEGER_CST))
6235 constructor_simple = 0;
6237 if (require_constant_value && ! TREE_CONSTANT (value))
6239 error_init ("initializer element is not constant");
6240 value = error_mark_node;
6242 else if (require_constant_elements
6243 && initializer_constant_valid_p (value, TREE_TYPE (value)) == 0)
6244 pedwarn ("initializer element is not computable at load time");
6246 /* If this field is empty (and not at the end of structure),
6247 don't do anything other than checking the initializer. */
6249 && (TREE_TYPE (field) == error_mark_node
6250 || (COMPLETE_TYPE_P (TREE_TYPE (field))
6251 && integer_zerop (TYPE_SIZE (TREE_TYPE (field)))
6252 && (TREE_CODE (constructor_type) == ARRAY_TYPE
6253 || TREE_CHAIN (field)))))
6256 value = digest_init (type, value, require_constant_value);
6257 if (value == error_mark_node)
6259 constructor_erroneous = 1;
6263 /* If this element doesn't come next in sequence,
6264 put it on constructor_pending_elts. */
6265 if (TREE_CODE (constructor_type) == ARRAY_TYPE
6266 && (!constructor_incremental
6267 || !tree_int_cst_equal (field, constructor_unfilled_index)))
6269 if (constructor_incremental
6270 && tree_int_cst_lt (field, constructor_unfilled_index))
6271 set_nonincremental_init ();
6273 add_pending_init (field, value);
6276 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6277 && (!constructor_incremental
6278 || field != constructor_unfilled_fields))
6280 /* We do this for records but not for unions. In a union,
6281 no matter which field is specified, it can be initialized
6282 right away since it starts at the beginning of the union. */
6283 if (constructor_incremental)
6285 if (!constructor_unfilled_fields)
6286 set_nonincremental_init ();
6289 tree bitpos, unfillpos;
6291 bitpos = bit_position (field);
6292 unfillpos = bit_position (constructor_unfilled_fields);
6294 if (tree_int_cst_lt (bitpos, unfillpos))
6295 set_nonincremental_init ();
6299 add_pending_init (field, value);
6302 else if (TREE_CODE (constructor_type) == UNION_TYPE
6303 && constructor_elements)
6305 if (TREE_SIDE_EFFECTS (TREE_VALUE (constructor_elements)))
6306 warning_init ("initialized field with side-effects overwritten");
6308 /* We can have just one union field set. */
6309 constructor_elements = 0;
6312 /* Otherwise, output this element either to
6313 constructor_elements or to the assembler file. */
6315 if (field && TREE_CODE (field) == INTEGER_CST)
6316 field = copy_node (field);
6317 constructor_elements
6318 = tree_cons (field, value, constructor_elements);
6320 /* Advance the variable that indicates sequential elements output. */
6321 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6322 constructor_unfilled_index
6323 = size_binop (PLUS_EXPR, constructor_unfilled_index,
6325 else if (TREE_CODE (constructor_type) == RECORD_TYPE)
6327 constructor_unfilled_fields
6328 = TREE_CHAIN (constructor_unfilled_fields);
6330 /* Skip any nameless bit fields. */
6331 while (constructor_unfilled_fields != 0
6332 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6333 && DECL_NAME (constructor_unfilled_fields) == 0)
6334 constructor_unfilled_fields =
6335 TREE_CHAIN (constructor_unfilled_fields);
6337 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6338 constructor_unfilled_fields = 0;
6340 /* Now output any pending elements which have become next. */
6342 output_pending_init_elements (0);
6345 /* Output any pending elements which have become next.
6346 As we output elements, constructor_unfilled_{fields,index}
6347 advances, which may cause other elements to become next;
6348 if so, they too are output.
6350 If ALL is 0, we return when there are
6351 no more pending elements to output now.
6353 If ALL is 1, we output space as necessary so that
6354 we can output all the pending elements. */
6357 output_pending_init_elements (all)
6360 struct init_node *elt = constructor_pending_elts;
6365 /* Look thru the whole pending tree.
6366 If we find an element that should be output now,
6367 output it. Otherwise, set NEXT to the element
6368 that comes first among those still pending. */
6373 if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6375 if (tree_int_cst_equal (elt->purpose,
6376 constructor_unfilled_index))
6377 output_init_element (elt->value,
6378 TREE_TYPE (constructor_type),
6379 constructor_unfilled_index, 0);
6380 else if (tree_int_cst_lt (constructor_unfilled_index,
6383 /* Advance to the next smaller node. */
6388 /* We have reached the smallest node bigger than the
6389 current unfilled index. Fill the space first. */
6390 next = elt->purpose;
6396 /* Advance to the next bigger node. */
6401 /* We have reached the biggest node in a subtree. Find
6402 the parent of it, which is the next bigger node. */
6403 while (elt->parent && elt->parent->right == elt)
6406 if (elt && tree_int_cst_lt (constructor_unfilled_index,
6409 next = elt->purpose;
6415 else if (TREE_CODE (constructor_type) == RECORD_TYPE
6416 || TREE_CODE (constructor_type) == UNION_TYPE)
6418 tree ctor_unfilled_bitpos, elt_bitpos;
6420 /* If the current record is complete we are done. */
6421 if (constructor_unfilled_fields == 0)
6424 ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields);
6425 elt_bitpos = bit_position (elt->purpose);
6426 /* We can't compare fields here because there might be empty
6427 fields in between. */
6428 if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos))
6430 constructor_unfilled_fields = elt->purpose;
6431 output_init_element (elt->value, TREE_TYPE (elt->purpose),
6434 else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos))
6436 /* Advance to the next smaller node. */
6441 /* We have reached the smallest node bigger than the
6442 current unfilled field. Fill the space first. */
6443 next = elt->purpose;
6449 /* Advance to the next bigger node. */
6454 /* We have reached the biggest node in a subtree. Find
6455 the parent of it, which is the next bigger node. */
6456 while (elt->parent && elt->parent->right == elt)
6460 && (tree_int_cst_lt (ctor_unfilled_bitpos,
6461 bit_position (elt->purpose))))
6463 next = elt->purpose;
6471 /* Ordinarily return, but not if we want to output all
6472 and there are elements left. */
6473 if (! (all && next != 0))
6476 /* If it's not incremental, just skip over the gap, so that after
6477 jumping to retry we will output the next successive element. */
6478 if (TREE_CODE (constructor_type) == RECORD_TYPE
6479 || TREE_CODE (constructor_type) == UNION_TYPE)
6480 constructor_unfilled_fields = next;
6481 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6482 constructor_unfilled_index = next;
6484 /* ELT now points to the node in the pending tree with the next
6485 initializer to output. */
6489 /* Add one non-braced element to the current constructor level.
6490 This adjusts the current position within the constructor's type.
6491 This may also start or terminate implicit levels
6492 to handle a partly-braced initializer.
6494 Once this has found the correct level for the new element,
6495 it calls output_init_element. */
6498 process_init_element (value)
6501 tree orig_value = value;
6502 int string_flag = value != 0 && TREE_CODE (value) == STRING_CST;
6504 designator_depth = 0;
6505 designator_errorneous = 0;
6507 /* Handle superfluous braces around string cst as in
6508 char x[] = {"foo"}; */
6511 && TREE_CODE (constructor_type) == ARRAY_TYPE
6512 && TREE_CODE (TREE_TYPE (constructor_type)) == INTEGER_TYPE
6513 && integer_zerop (constructor_unfilled_index))
6515 if (constructor_stack->replacement_value)
6516 error_init ("excess elements in char array initializer");
6517 constructor_stack->replacement_value = value;
6521 if (constructor_stack->replacement_value != 0)
6523 error_init ("excess elements in struct initializer");
6527 /* Ignore elements of a brace group if it is entirely superfluous
6528 and has already been diagnosed. */
6529 if (constructor_type == 0)
6532 /* If we've exhausted any levels that didn't have braces,
6534 while (constructor_stack->implicit)
6536 if ((TREE_CODE (constructor_type) == RECORD_TYPE
6537 || TREE_CODE (constructor_type) == UNION_TYPE)
6538 && constructor_fields == 0)
6539 process_init_element (pop_init_level (1));
6540 else if (TREE_CODE (constructor_type) == ARRAY_TYPE
6541 && (constructor_max_index == 0
6542 || tree_int_cst_lt (constructor_max_index,
6543 constructor_index)))
6544 process_init_element (pop_init_level (1));
6549 /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */
6550 if (constructor_range_stack)
6552 /* If value is a compound literal and we'll be just using its
6553 content, don't put it into a SAVE_EXPR. */
6554 if (TREE_CODE (value) != COMPOUND_LITERAL_EXPR
6555 || !require_constant_value
6557 value = save_expr (value);
6562 if (TREE_CODE (constructor_type) == RECORD_TYPE)
6565 enum tree_code fieldcode;
6567 if (constructor_fields == 0)
6569 pedwarn_init ("excess elements in struct initializer");
6573 fieldtype = TREE_TYPE (constructor_fields);
6574 if (fieldtype != error_mark_node)
6575 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6576 fieldcode = TREE_CODE (fieldtype);
6578 /* Error for non-static initialization of a flexible array member. */
6579 if (fieldcode == ARRAY_TYPE
6580 && !require_constant_value
6581 && TYPE_SIZE (fieldtype) == NULL_TREE
6582 && TREE_CHAIN (constructor_fields) == NULL_TREE)
6584 error_init ("non-static initialization of a flexible array member");
6588 /* Accept a string constant to initialize a subarray. */
6590 && fieldcode == ARRAY_TYPE
6591 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE
6594 /* Otherwise, if we have come to a subaggregate,
6595 and we don't have an element of its type, push into it. */
6596 else if (value != 0 && !constructor_no_implicit
6597 && value != error_mark_node
6598 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype
6599 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6600 || fieldcode == UNION_TYPE))
6602 push_init_level (1);
6608 push_member_name (constructor_fields);
6609 output_init_element (value, fieldtype, constructor_fields, 1);
6610 RESTORE_SPELLING_DEPTH (constructor_depth);
6613 /* Do the bookkeeping for an element that was
6614 directly output as a constructor. */
6616 /* For a record, keep track of end position of last field. */
6617 if (DECL_SIZE (constructor_fields))
6618 constructor_bit_index
6619 = size_binop (PLUS_EXPR,
6620 bit_position (constructor_fields),
6621 DECL_SIZE (constructor_fields));
6623 /* If the current field was the first one not yet written out,
6624 it isn't now, so update. */
6625 if (constructor_unfilled_fields == constructor_fields)
6627 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6628 /* Skip any nameless bit fields. */
6629 while (constructor_unfilled_fields != 0
6630 && DECL_C_BIT_FIELD (constructor_unfilled_fields)
6631 && DECL_NAME (constructor_unfilled_fields) == 0)
6632 constructor_unfilled_fields =
6633 TREE_CHAIN (constructor_unfilled_fields);
6637 constructor_fields = TREE_CHAIN (constructor_fields);
6638 /* Skip any nameless bit fields at the beginning. */
6639 while (constructor_fields != 0
6640 && DECL_C_BIT_FIELD (constructor_fields)
6641 && DECL_NAME (constructor_fields) == 0)
6642 constructor_fields = TREE_CHAIN (constructor_fields);
6644 else if (TREE_CODE (constructor_type) == UNION_TYPE)
6647 enum tree_code fieldcode;
6649 if (constructor_fields == 0)
6651 pedwarn_init ("excess elements in union initializer");
6655 fieldtype = TREE_TYPE (constructor_fields);
6656 if (fieldtype != error_mark_node)
6657 fieldtype = TYPE_MAIN_VARIANT (fieldtype);
6658 fieldcode = TREE_CODE (fieldtype);
6660 /* Warn that traditional C rejects initialization of unions.
6661 We skip the warning if the value is zero. This is done
6662 under the assumption that the zero initializer in user
6663 code appears conditioned on e.g. __STDC__ to avoid
6664 "missing initializer" warnings and relies on default
6665 initialization to zero in the traditional C case.
6666 We also skip the warning if the initializer is designated,
6667 again on the assumption that this must be conditional on
6668 __STDC__ anyway (and we've already complained about the
6669 member-designator already). */
6670 if (warn_traditional && !in_system_header && !constructor_designated
6671 && !(value && (integer_zerop (value) || real_zerop (value))))
6672 warning ("traditional C rejects initialization of unions");
6674 /* Accept a string constant to initialize a subarray. */
6676 && fieldcode == ARRAY_TYPE
6677 && TREE_CODE (TREE_TYPE (fieldtype)) == INTEGER_TYPE
6680 /* Otherwise, if we have come to a subaggregate,
6681 and we don't have an element of its type, push into it. */
6682 else if (value != 0 && !constructor_no_implicit
6683 && value != error_mark_node
6684 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != fieldtype
6685 && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE
6686 || fieldcode == UNION_TYPE))
6688 push_init_level (1);
6694 push_member_name (constructor_fields);
6695 output_init_element (value, fieldtype, constructor_fields, 1);
6696 RESTORE_SPELLING_DEPTH (constructor_depth);
6699 /* Do the bookkeeping for an element that was
6700 directly output as a constructor. */
6702 constructor_bit_index = DECL_SIZE (constructor_fields);
6703 constructor_unfilled_fields = TREE_CHAIN (constructor_fields);
6706 constructor_fields = 0;
6708 else if (TREE_CODE (constructor_type) == ARRAY_TYPE)
6710 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6711 enum tree_code eltcode = TREE_CODE (elttype);
6713 /* Accept a string constant to initialize a subarray. */
6715 && eltcode == ARRAY_TYPE
6716 && TREE_CODE (TREE_TYPE (elttype)) == INTEGER_TYPE
6719 /* Otherwise, if we have come to a subaggregate,
6720 and we don't have an element of its type, push into it. */
6721 else if (value != 0 && !constructor_no_implicit
6722 && value != error_mark_node
6723 && TYPE_MAIN_VARIANT (TREE_TYPE (value)) != elttype
6724 && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE
6725 || eltcode == UNION_TYPE))
6727 push_init_level (1);
6731 if (constructor_max_index != 0
6732 && (tree_int_cst_lt (constructor_max_index, constructor_index)
6733 || integer_all_onesp (constructor_max_index)))
6735 pedwarn_init ("excess elements in array initializer");
6739 /* Now output the actual element. */
6742 push_array_bounds (tree_low_cst (constructor_index, 0));
6743 output_init_element (value, elttype, constructor_index, 1);
6744 RESTORE_SPELLING_DEPTH (constructor_depth);
6748 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6751 /* If we are doing the bookkeeping for an element that was
6752 directly output as a constructor, we must update
6753 constructor_unfilled_index. */
6754 constructor_unfilled_index = constructor_index;
6756 else if (TREE_CODE (constructor_type) == VECTOR_TYPE)
6758 tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type));
6760 /* Do a basic check of initializer size. Note that vectors
6761 always have a fixed size derived from their type. */
6762 if (tree_int_cst_lt (constructor_max_index, constructor_index))
6764 pedwarn_init ("excess elements in vector initializer");
6768 /* Now output the actual element. */
6770 output_init_element (value, elttype, constructor_index, 1);
6773 = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node);
6776 /* If we are doing the bookkeeping for an element that was
6777 directly output as a constructor, we must update
6778 constructor_unfilled_index. */
6779 constructor_unfilled_index = constructor_index;
6782 /* Handle the sole element allowed in a braced initializer
6783 for a scalar variable. */
6784 else if (constructor_fields == 0)
6786 pedwarn_init ("excess elements in scalar initializer");
6792 output_init_element (value, constructor_type, NULL_TREE, 1);
6793 constructor_fields = 0;
6796 /* Handle range initializers either at this level or anywhere higher
6797 in the designator stack. */
6798 if (constructor_range_stack)
6800 struct constructor_range_stack *p, *range_stack;
6803 range_stack = constructor_range_stack;
6804 constructor_range_stack = 0;
6805 while (constructor_stack != range_stack->stack)
6807 if (!constructor_stack->implicit)
6809 process_init_element (pop_init_level (1));
6811 for (p = range_stack;
6812 !p->range_end || tree_int_cst_equal (p->index, p->range_end);
6815 if (!constructor_stack->implicit)
6817 process_init_element (pop_init_level (1));
6820 p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node);
6821 if (tree_int_cst_equal (p->index, p->range_end) && !p->prev)
6826 constructor_index = p->index;
6827 constructor_fields = p->fields;
6828 if (finish && p->range_end && p->index == p->range_start)
6836 push_init_level (2);
6837 p->stack = constructor_stack;
6838 if (p->range_end && tree_int_cst_equal (p->index, p->range_end))
6839 p->index = p->range_start;
6843 constructor_range_stack = range_stack;
6850 constructor_range_stack = 0;
6853 /* Build a simple asm-statement, from one string literal. */
6855 simple_asm_stmt (expr)
6860 if (TREE_CODE (expr) == ADDR_EXPR)
6861 expr = TREE_OPERAND (expr, 0);
6863 if (TREE_CODE (expr) == STRING_CST)
6867 /* Simple asm statements are treated as volatile. */
6868 stmt = add_stmt (build_stmt (ASM_STMT, ridpointers[(int) RID_VOLATILE],
6869 expr, NULL_TREE, NULL_TREE, NULL_TREE));
6870 ASM_INPUT_P (stmt) = 1;
6874 error ("argument of `asm' is not a constant string");
6878 /* Build an asm-statement, whose components are a CV_QUALIFIER, a
6879 STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. */
6882 build_asm_stmt (cv_qualifier, string, outputs, inputs, clobbers)
6891 if (TREE_CODE (string) != STRING_CST)
6893 error ("asm template is not a string constant");
6897 if (cv_qualifier != NULL_TREE
6898 && cv_qualifier != ridpointers[(int) RID_VOLATILE])
6900 warning ("%s qualifier ignored on asm",
6901 IDENTIFIER_POINTER (cv_qualifier));
6902 cv_qualifier = NULL_TREE;
6905 /* We can remove output conversions that change the type,
6906 but not the mode. */
6907 for (tail = outputs; tail; tail = TREE_CHAIN (tail))
6909 tree output = TREE_VALUE (tail);
6911 STRIP_NOPS (output);
6912 TREE_VALUE (tail) = output;
6914 /* Allow conversions as LHS here. build_modify_expr as called below
6915 will do the right thing with them. */
6916 while (TREE_CODE (output) == NOP_EXPR
6917 || TREE_CODE (output) == CONVERT_EXPR
6918 || TREE_CODE (output) == FLOAT_EXPR
6919 || TREE_CODE (output) == FIX_TRUNC_EXPR
6920 || TREE_CODE (output) == FIX_FLOOR_EXPR
6921 || TREE_CODE (output) == FIX_ROUND_EXPR
6922 || TREE_CODE (output) == FIX_CEIL_EXPR)
6923 output = TREE_OPERAND (output, 0);
6925 lvalue_or_else (TREE_VALUE (tail), "invalid lvalue in asm statement");
6928 /* Remove output conversions that change the type but not the mode. */
6929 for (tail = outputs; tail; tail = TREE_CHAIN (tail))
6931 tree output = TREE_VALUE (tail);
6932 STRIP_NOPS (output);
6933 TREE_VALUE (tail) = output;
6936 /* Perform default conversions on array and function inputs.
6937 Don't do this for other types as it would screw up operands
6938 expected to be in memory. */
6939 for (tail = inputs; tail; tail = TREE_CHAIN (tail))
6940 TREE_VALUE (tail) = default_function_array_conversion (TREE_VALUE (tail));
6942 return add_stmt (build_stmt (ASM_STMT, cv_qualifier, string,
6943 outputs, inputs, clobbers));
6946 /* Expand an ASM statement with operands, handling output operands
6947 that are not variables or INDIRECT_REFS by transforming such
6948 cases into cases that expand_asm_operands can handle.
6950 Arguments are same as for expand_asm_operands. */
6953 c_expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line)
6954 tree string, outputs, inputs, clobbers;
6956 const char *filename;
6959 int noutputs = list_length (outputs);
6961 /* o[I] is the place that output number I should be written. */
6962 tree *o = (tree *) alloca (noutputs * sizeof (tree));
6965 /* Record the contents of OUTPUTS before it is modified. */
6966 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
6968 o[i] = TREE_VALUE (tail);
6969 if (o[i] == error_mark_node)
6973 /* Generate the ASM_OPERANDS insn; store into the TREE_VALUEs of
6974 OUTPUTS some trees for where the values were actually stored. */
6975 expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line);
6977 /* Copy all the intermediate outputs into the specified outputs. */
6978 for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++)
6980 if (o[i] != TREE_VALUE (tail))
6982 expand_expr (build_modify_expr (o[i], NOP_EXPR, TREE_VALUE (tail)),
6983 NULL_RTX, VOIDmode, EXPAND_NORMAL);
6986 /* Restore the original value so that it's correct the next
6987 time we expand this function. */
6988 TREE_VALUE (tail) = o[i];
6990 /* Detect modification of read-only values.
6991 (Otherwise done by build_modify_expr.) */
6994 tree type = TREE_TYPE (o[i]);
6995 if (TREE_READONLY (o[i])
6996 || TYPE_READONLY (type)
6997 || ((TREE_CODE (type) == RECORD_TYPE
6998 || TREE_CODE (type) == UNION_TYPE)
6999 && C_TYPE_FIELDS_READONLY (type)))
7000 readonly_warning (o[i], "modification by `asm'");
7004 /* Those MODIFY_EXPRs could do autoincrements. */
7008 /* Expand a C `return' statement.
7009 RETVAL is the expression for what to return,
7010 or a null pointer for `return;' with no value. */
7013 c_expand_return (retval)
7016 tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl));
7018 if (TREE_THIS_VOLATILE (current_function_decl))
7019 warning ("function declared `noreturn' has a `return' statement");
7023 current_function_returns_null = 1;
7024 if ((warn_return_type || flag_isoc99)
7025 && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE)
7026 pedwarn_c99 ("`return' with no value, in function returning non-void");
7028 else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE)
7030 current_function_returns_null = 1;
7031 if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE)
7032 pedwarn ("`return' with a value, in function returning void");
7036 tree t = convert_for_assignment (valtype, retval, _("return"),
7037 NULL_TREE, NULL_TREE, 0);
7038 tree res = DECL_RESULT (current_function_decl);
7041 current_function_returns_value = 1;
7042 if (t == error_mark_node)
7045 inner = t = convert (TREE_TYPE (res), t);
7047 /* Strip any conversions, additions, and subtractions, and see if
7048 we are returning the address of a local variable. Warn if so. */
7051 switch (TREE_CODE (inner))
7053 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
7055 inner = TREE_OPERAND (inner, 0);
7059 /* If the second operand of the MINUS_EXPR has a pointer
7060 type (or is converted from it), this may be valid, so
7061 don't give a warning. */
7063 tree op1 = TREE_OPERAND (inner, 1);
7065 while (! POINTER_TYPE_P (TREE_TYPE (op1))
7066 && (TREE_CODE (op1) == NOP_EXPR
7067 || TREE_CODE (op1) == NON_LVALUE_EXPR
7068 || TREE_CODE (op1) == CONVERT_EXPR))
7069 op1 = TREE_OPERAND (op1, 0);
7071 if (POINTER_TYPE_P (TREE_TYPE (op1)))
7074 inner = TREE_OPERAND (inner, 0);
7079 inner = TREE_OPERAND (inner, 0);
7081 while (TREE_CODE_CLASS (TREE_CODE (inner)) == 'r')
7082 inner = TREE_OPERAND (inner, 0);
7084 if (TREE_CODE (inner) == VAR_DECL
7085 && ! DECL_EXTERNAL (inner)
7086 && ! TREE_STATIC (inner)
7087 && DECL_CONTEXT (inner) == current_function_decl)
7088 warning ("function returns address of local variable");
7098 retval = build (MODIFY_EXPR, TREE_TYPE (res), res, t);
7101 return add_stmt (build_return_stmt (retval));
7105 /* The SWITCH_STMT being built. */
7107 /* A splay-tree mapping the low element of a case range to the high
7108 element, or NULL_TREE if there is no high element. Used to
7109 determine whether or not a new case label duplicates an old case
7110 label. We need a tree, rather than simply a hash table, because
7111 of the GNU case range extension. */
7113 /* The next node on the stack. */
7114 struct c_switch *next;
7117 /* A stack of the currently active switch statements. The innermost
7118 switch statement is on the top of the stack. There is no need to
7119 mark the stack for garbage collection because it is only active
7120 during the processing of the body of a function, and we never
7121 collect at that point. */
7123 static struct c_switch *switch_stack;
7125 /* Start a C switch statement, testing expression EXP. Return the new
7132 enum tree_code code;
7133 tree type, orig_type = error_mark_node;
7134 struct c_switch *cs;
7136 if (exp != error_mark_node)
7138 code = TREE_CODE (TREE_TYPE (exp));
7139 orig_type = TREE_TYPE (exp);
7141 if (! INTEGRAL_TYPE_P (orig_type)
7142 && code != ERROR_MARK)
7144 error ("switch quantity not an integer");
7145 exp = integer_zero_node;
7149 type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
7151 if (warn_traditional && !in_system_header
7152 && (type == long_integer_type_node
7153 || type == long_unsigned_type_node))
7154 warning ("`long' switch expression not converted to `int' in ISO C");
7156 exp = default_conversion (exp);
7157 type = TREE_TYPE (exp);
7161 /* Add this new SWITCH_STMT to the stack. */
7162 cs = (struct c_switch *) xmalloc (sizeof (*cs));
7163 cs->switch_stmt = build_stmt (SWITCH_STMT, exp, NULL_TREE, orig_type);
7164 cs->cases = splay_tree_new (case_compare, NULL, NULL);
7165 cs->next = switch_stack;
7168 return add_stmt (switch_stack->switch_stmt);
7171 /* Process a case label. */
7174 do_case (low_value, high_value)
7178 tree label = NULL_TREE;
7182 label = c_add_case_label (switch_stack->cases,
7183 SWITCH_COND (switch_stack->switch_stmt),
7184 low_value, high_value);
7185 if (label == error_mark_node)
7189 error ("case label not within a switch statement");
7191 error ("`default' label not within a switch statement");
7196 /* Finish the switch statement. */
7201 struct c_switch *cs = switch_stack;
7203 RECHAIN_STMTS (cs->switch_stmt, SWITCH_BODY (cs->switch_stmt));
7205 /* Pop the stack. */
7206 switch_stack = switch_stack->next;
7207 splay_tree_delete (cs->cases);