/* Build expressions with type checking for C compiler. Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GCC; see the file COPYING. If not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* This file is part of the C front end. It contains routines to build C expressions given their operands, including computing the types of the result, C-specific error checks, and some optimization. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "rtl.h" #include "tree.h" #include "langhooks.h" #include "c-tree.h" #include "tm_p.h" #include "flags.h" #include "output.h" #include "expr.h" #include "toplev.h" #include "intl.h" #include "ggc.h" #include "target.h" #include "tree-iterator.h" #include "tree-gimple.h" #include "tree-flow.h" /* Possible cases of implicit bad conversions. Used to select diagnostic messages in convert_for_assignment. */ enum impl_conv { ic_argpass, ic_argpass_nonproto, ic_assign, ic_init, ic_return }; /* The level of nesting inside "__alignof__". */ int in_alignof; /* The level of nesting inside "sizeof". */ int in_sizeof; /* The level of nesting inside "typeof". */ int in_typeof; /* Nonzero if we've already printed a "missing braces around initializer" message within this initializer. */ static int missing_braces_mentioned; static int require_constant_value; static int require_constant_elements; static tree qualify_type (tree, tree); static int tagged_types_tu_compatible_p (tree, tree); static int comp_target_types (tree, tree, int); static int function_types_compatible_p (tree, tree); static int type_lists_compatible_p (tree, tree); static tree decl_constant_value_for_broken_optimization (tree); static tree default_function_array_conversion (tree); static tree lookup_field (tree, tree); static tree convert_arguments (tree, tree, tree, tree); static tree pointer_diff (tree, tree); static tree convert_for_assignment (tree, tree, enum impl_conv, tree, tree, int); static tree valid_compound_expr_initializer (tree, tree); static void push_string (const char *); static void push_member_name (tree); static void push_array_bounds (int); static int spelling_length (void); static char *print_spelling (char *); static void warning_init (const char *); static tree digest_init (tree, tree, bool, int); static void output_init_element (tree, bool, tree, tree, int); static void output_pending_init_elements (int); static int set_designator (int); static void push_range_stack (tree); static void add_pending_init (tree, tree); static void set_nonincremental_init (void); static void set_nonincremental_init_from_string (tree); static tree find_init_member (tree); static void readonly_error (tree, enum lvalue_use); static int lvalue_or_else (tree, enum lvalue_use); static int lvalue_p (tree); static void record_maybe_used_decl (tree); /* Do `exp = require_complete_type (exp);' to make sure exp does not have an incomplete type. (That includes void types.) */ tree require_complete_type (tree value) { tree type = TREE_TYPE (value); if (value == error_mark_node || type == error_mark_node) return error_mark_node; /* First, detect a valid value with a complete type. */ if (COMPLETE_TYPE_P (type)) return value; c_incomplete_type_error (value, type); return error_mark_node; } /* Print an error message for invalid use of an incomplete type. VALUE is the expression that was used (or 0 if that isn't known) and TYPE is the type that was invalid. */ void c_incomplete_type_error (tree value, tree type) { const char *type_code_string; /* Avoid duplicate error message. */ if (TREE_CODE (type) == ERROR_MARK) return; if (value != 0 && (TREE_CODE (value) == VAR_DECL || TREE_CODE (value) == PARM_DECL)) error ("%qD has an incomplete type", value); else { retry: /* We must print an error message. Be clever about what it says. */ switch (TREE_CODE (type)) { case RECORD_TYPE: type_code_string = "struct"; break; case UNION_TYPE: type_code_string = "union"; break; case ENUMERAL_TYPE: type_code_string = "enum"; break; case VOID_TYPE: error ("invalid use of void expression"); return; case ARRAY_TYPE: if (TYPE_DOMAIN (type)) { if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL) { error ("invalid use of flexible array member"); return; } type = TREE_TYPE (type); goto retry; } error ("invalid use of array with unspecified bounds"); return; default: gcc_unreachable (); } if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE) error ("invalid use of undefined type %<%s %E%>", type_code_string, TYPE_NAME (type)); else /* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */ error ("invalid use of incomplete typedef %qD", TYPE_NAME (type)); } } /* Given a type, apply default promotions wrt unnamed function arguments and return the new type. */ tree c_type_promotes_to (tree type) { if (TYPE_MAIN_VARIANT (type) == float_type_node) return double_type_node; if (c_promoting_integer_type_p (type)) { /* Preserve unsignedness if not really getting any wider. */ if (TYPE_UNSIGNED (type) && (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node))) return unsigned_type_node; return integer_type_node; } return type; } /* Return a variant of TYPE which has all the type qualifiers of LIKE as well as those of TYPE. */ static tree qualify_type (tree type, tree like) { return c_build_qualified_type (type, TYPE_QUALS (type) | TYPE_QUALS (like)); } /* Return the composite type of two compatible types. We assume that comptypes has already been done and returned nonzero; if that isn't so, this may crash. In particular, we assume that qualifiers match. */ tree composite_type (tree t1, tree t2) { enum tree_code code1; enum tree_code code2; tree attributes; /* Save time if the two types are the same. */ if (t1 == t2) return t1; /* If one type is nonsense, use the other. */ if (t1 == error_mark_node) return t2; if (t2 == error_mark_node) return t1; code1 = TREE_CODE (t1); code2 = TREE_CODE (t2); /* Merge the attributes. */ attributes = targetm.merge_type_attributes (t1, t2); /* If one is an enumerated type and the other is the compatible integer type, the composite type might be either of the two (DR#013 question 3). For consistency, use the enumerated type as the composite type. */ if (code1 == ENUMERAL_TYPE && code2 == INTEGER_TYPE) return t1; if (code2 == ENUMERAL_TYPE && code1 == INTEGER_TYPE) return t2; gcc_assert (code1 == code2); switch (code1) { case POINTER_TYPE: /* For two pointers, do this recursively on the target type. */ { tree pointed_to_1 = TREE_TYPE (t1); tree pointed_to_2 = TREE_TYPE (t2); tree target = composite_type (pointed_to_1, pointed_to_2); t1 = build_pointer_type (target); t1 = build_type_attribute_variant (t1, attributes); return qualify_type (t1, t2); } case ARRAY_TYPE: { tree elt = composite_type (TREE_TYPE (t1), TREE_TYPE (t2)); int quals; tree unqual_elt; /* We should not have any type quals on arrays at all. */ gcc_assert (!TYPE_QUALS (t1) && !TYPE_QUALS (t2)); /* Save space: see if the result is identical to one of the args. */ if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1)) return build_type_attribute_variant (t1, attributes); if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2)) return build_type_attribute_variant (t2, attributes); if (elt == TREE_TYPE (t1) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1)) return build_type_attribute_variant (t1, attributes); if (elt == TREE_TYPE (t2) && !TYPE_DOMAIN (t2) && !TYPE_DOMAIN (t1)) return build_type_attribute_variant (t2, attributes); /* Merge the element types, and have a size if either arg has one. We may have qualifiers on the element types. To set up TYPE_MAIN_VARIANT correctly, we need to form the composite of the unqualified types and add the qualifiers back at the end. */ quals = TYPE_QUALS (strip_array_types (elt)); unqual_elt = c_build_qualified_type (elt, TYPE_UNQUALIFIED); t1 = build_array_type (unqual_elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2)); t1 = c_build_qualified_type (t1, quals); return build_type_attribute_variant (t1, attributes); } case FUNCTION_TYPE: /* Function types: prefer the one that specified arg types. If both do, merge the arg types. Also merge the return types. */ { tree valtype = composite_type (TREE_TYPE (t1), TREE_TYPE (t2)); tree p1 = TYPE_ARG_TYPES (t1); tree p2 = TYPE_ARG_TYPES (t2); int len; tree newargs, n; int i; /* Save space: see if the result is identical to one of the args. */ if (valtype == TREE_TYPE (t1) && !TYPE_ARG_TYPES (t2)) return build_type_attribute_variant (t1, attributes); if (valtype == TREE_TYPE (t2) && !TYPE_ARG_TYPES (t1)) return build_type_attribute_variant (t2, attributes); /* Simple way if one arg fails to specify argument types. */ if (TYPE_ARG_TYPES (t1) == 0) { t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2)); t1 = build_type_attribute_variant (t1, attributes); return qualify_type (t1, t2); } if (TYPE_ARG_TYPES (t2) == 0) { t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1)); t1 = build_type_attribute_variant (t1, attributes); return qualify_type (t1, t2); } /* If both args specify argument types, we must merge the two lists, argument by argument. */ /* Tell global_bindings_p to return false so that variable_size doesn't abort on VLAs in parameter types. */ c_override_global_bindings_to_false = true; len = list_length (p1); newargs = 0; for (i = 0; i < len; i++) newargs = tree_cons (NULL_TREE, NULL_TREE, newargs); n = newargs; for (; p1; p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n)) { /* A null type means arg type is not specified. Take whatever the other function type has. */ if (TREE_VALUE (p1) == 0) { TREE_VALUE (n) = TREE_VALUE (p2); goto parm_done; } if (TREE_VALUE (p2) == 0) { TREE_VALUE (n) = TREE_VALUE (p1); goto parm_done; } /* Given wait (union {union wait *u; int *i} *) and wait (union wait *), prefer union wait * as type of parm. */ if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE && TREE_VALUE (p1) != TREE_VALUE (p2)) { tree memb; tree mv2 = TREE_VALUE (p2); if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE) mv2 = TYPE_MAIN_VARIANT (mv2); for (memb = TYPE_FIELDS (TREE_VALUE (p1)); memb; memb = TREE_CHAIN (memb)) { tree mv3 = TREE_TYPE (memb); if (mv3 && mv3 != error_mark_node && TREE_CODE (mv3) != ARRAY_TYPE) mv3 = TYPE_MAIN_VARIANT (mv3); if (comptypes (mv3, mv2)) { TREE_VALUE (n) = composite_type (TREE_TYPE (memb), TREE_VALUE (p2)); if (pedantic) pedwarn ("function types not truly compatible in ISO C"); goto parm_done; } } } if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE && TREE_VALUE (p2) != TREE_VALUE (p1)) { tree memb; tree mv1 = TREE_VALUE (p1); if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE) mv1 = TYPE_MAIN_VARIANT (mv1); for (memb = TYPE_FIELDS (TREE_VALUE (p2)); memb; memb = TREE_CHAIN (memb)) { tree mv3 = TREE_TYPE (memb); if (mv3 && mv3 != error_mark_node && TREE_CODE (mv3) != ARRAY_TYPE) mv3 = TYPE_MAIN_VARIANT (mv3); if (comptypes (mv3, mv1)) { TREE_VALUE (n) = composite_type (TREE_TYPE (memb), TREE_VALUE (p1)); if (pedantic) pedwarn ("function types not truly compatible in ISO C"); goto parm_done; } } } TREE_VALUE (n) = composite_type (TREE_VALUE (p1), TREE_VALUE (p2)); parm_done: ; } c_override_global_bindings_to_false = false; t1 = build_function_type (valtype, newargs); t1 = qualify_type (t1, t2); /* ... falls through ... */ } default: return build_type_attribute_variant (t1, attributes); } } /* Return the type of a conditional expression between pointers to possibly differently qualified versions of compatible types. We assume that comp_target_types has already been done and returned nonzero; if that isn't so, this may crash. */ static tree common_pointer_type (tree t1, tree t2) { tree attributes; tree pointed_to_1, mv1; tree pointed_to_2, mv2; tree target; /* Save time if the two types are the same. */ if (t1 == t2) return t1; /* If one type is nonsense, use the other. */ if (t1 == error_mark_node) return t2; if (t2 == error_mark_node) return t1; gcc_assert (TREE_CODE (t1) == POINTER_TYPE && TREE_CODE (t2) == POINTER_TYPE); /* Merge the attributes. */ attributes = targetm.merge_type_attributes (t1, t2); /* Find the composite type of the target types, and combine the qualifiers of the two types' targets. Do not lose qualifiers on array element types by taking the TYPE_MAIN_VARIANT. */ mv1 = pointed_to_1 = TREE_TYPE (t1); mv2 = pointed_to_2 = TREE_TYPE (t2); if (TREE_CODE (mv1) != ARRAY_TYPE) mv1 = TYPE_MAIN_VARIANT (pointed_to_1); if (TREE_CODE (mv2) != ARRAY_TYPE) mv2 = TYPE_MAIN_VARIANT (pointed_to_2); target = composite_type (mv1, mv2); t1 = build_pointer_type (c_build_qualified_type (target, TYPE_QUALS (pointed_to_1) | TYPE_QUALS (pointed_to_2))); return build_type_attribute_variant (t1, attributes); } /* Return the common type for two arithmetic types under the usual arithmetic conversions. The default conversions have already been applied, and enumerated types converted to their compatible integer types. The resulting type is unqualified and has no attributes. This is the type for the result of most arithmetic operations if the operands have the given two types. */ static tree c_common_type (tree t1, tree t2) { enum tree_code code1; enum tree_code code2; /* If one type is nonsense, use the other. */ if (t1 == error_mark_node) return t2; if (t2 == error_mark_node) return t1; if (TYPE_QUALS (t1) != TYPE_UNQUALIFIED) t1 = TYPE_MAIN_VARIANT (t1); if (TYPE_QUALS (t2) != TYPE_UNQUALIFIED) t2 = TYPE_MAIN_VARIANT (t2); if (TYPE_ATTRIBUTES (t1) != NULL_TREE) t1 = build_type_attribute_variant (t1, NULL_TREE); if (TYPE_ATTRIBUTES (t2) != NULL_TREE) t2 = build_type_attribute_variant (t2, NULL_TREE); /* Save time if the two types are the same. */ if (t1 == t2) return t1; code1 = TREE_CODE (t1); code2 = TREE_CODE (t2); gcc_assert (code1 == VECTOR_TYPE || code1 == COMPLEX_TYPE || code1 == REAL_TYPE || code1 == INTEGER_TYPE); gcc_assert (code2 == VECTOR_TYPE || code2 == COMPLEX_TYPE || code2 == REAL_TYPE || code2 == INTEGER_TYPE); /* If one type is a vector type, return that type. (How the usual arithmetic conversions apply to the vector types extension is not precisely specified.) */ if (code1 == VECTOR_TYPE) return t1; if (code2 == VECTOR_TYPE) return t2; /* If one type is complex, form the common type of the non-complex components, then make that complex. Use T1 or T2 if it is the required type. */ if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE) { tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1; tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2; tree subtype = c_common_type (subtype1, subtype2); if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype) return t1; else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype) return t2; else return build_complex_type (subtype); } /* If only one is real, use it as the result. */ if (code1 == REAL_TYPE && code2 != REAL_TYPE) return t1; if (code2 == REAL_TYPE && code1 != REAL_TYPE) return t2; /* Both real or both integers; use the one with greater precision. */ if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2)) return t1; else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1)) return t2; /* Same precision. Prefer long longs to longs to ints when the same precision, following the C99 rules on integer type rank (which are equivalent to the C90 rules for C90 types). */ if (TYPE_MAIN_VARIANT (t1) == long_long_unsigned_type_node || TYPE_MAIN_VARIANT (t2) == long_long_unsigned_type_node) return long_long_unsigned_type_node; if (TYPE_MAIN_VARIANT (t1) == long_long_integer_type_node || TYPE_MAIN_VARIANT (t2) == long_long_integer_type_node) { if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) return long_long_unsigned_type_node; else return long_long_integer_type_node; } if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node || TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node) return long_unsigned_type_node; if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node || TYPE_MAIN_VARIANT (t2) == long_integer_type_node) { /* But preserve unsignedness from the other type, since long cannot hold all the values of an unsigned int. */ if (TYPE_UNSIGNED (t1) || TYPE_UNSIGNED (t2)) return long_unsigned_type_node; else return long_integer_type_node; } /* Likewise, prefer long double to double even if same size. */ if (TYPE_MAIN_VARIANT (t1) == long_double_type_node || TYPE_MAIN_VARIANT (t2) == long_double_type_node) return long_double_type_node; /* Otherwise prefer the unsigned one. */ if (TYPE_UNSIGNED (t1)) return t1; else return t2; } /* Wrapper around c_common_type that is used by c-common.c. ENUMERAL_TYPEs are allowed here and are converted to their compatible integer types. */ tree common_type (tree t1, tree t2) { if (TREE_CODE (t1) == ENUMERAL_TYPE) t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1); if (TREE_CODE (t2) == ENUMERAL_TYPE) t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1); return c_common_type (t1, t2); } /* Return 1 if TYPE1 and TYPE2 are compatible types for assignment or various other operations. Return 2 if they are compatible but a warning may be needed if you use them together. */ int comptypes (tree type1, tree type2) { tree t1 = type1; tree t2 = type2; int attrval, val; /* Suppress errors caused by previously reported errors. */ if (t1 == t2 || !t1 || !t2 || TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK) return 1; /* If either type is the internal version of sizetype, return the language version. */ if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1) && TYPE_ORIG_SIZE_TYPE (t1)) t1 = TYPE_ORIG_SIZE_TYPE (t1); if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2) && TYPE_ORIG_SIZE_TYPE (t2)) t2 = TYPE_ORIG_SIZE_TYPE (t2); /* Enumerated types are compatible with integer types, but this is not transitive: two enumerated types in the same translation unit are compatible with each other only if they are the same type. */ if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE) t1 = c_common_type_for_size (TYPE_PRECISION (t1), TYPE_UNSIGNED (t1)); else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE) t2 = c_common_type_for_size (TYPE_PRECISION (t2), TYPE_UNSIGNED (t2)); if (t1 == t2) return 1; /* Different classes of types can't be compatible. */ if (TREE_CODE (t1) != TREE_CODE (t2)) return 0; /* Qualifiers must match. C99 6.7.3p9 */ if (TYPE_QUALS (t1) != TYPE_QUALS (t2)) return 0; /* Allow for two different type nodes which have essentially the same definition. Note that we already checked for equality of the type qualifiers (just above). */ if (TREE_CODE (t1) != ARRAY_TYPE && TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2)) return 1; /* 1 if no need for warning yet, 2 if warning cause has been seen. */ if (!(attrval = targetm.comp_type_attributes (t1, t2))) return 0; /* 1 if no need for warning yet, 2 if warning cause has been seen. */ val = 0; switch (TREE_CODE (t1)) { case POINTER_TYPE: /* We must give ObjC the first crack at comparing pointers, since protocol qualifiers may be involved. */ if (c_dialect_objc () && (val = objc_comptypes (t1, t2, 0)) >= 0) break; /* Do not remove mode or aliasing information. */ if (TYPE_MODE (t1) != TYPE_MODE (t2) || TYPE_REF_CAN_ALIAS_ALL (t1) != TYPE_REF_CAN_ALIAS_ALL (t2)) break; val = (TREE_TYPE (t1) == TREE_TYPE (t2) ? 1 : comptypes (TREE_TYPE (t1), TREE_TYPE (t2))); break; case FUNCTION_TYPE: val = function_types_compatible_p (t1, t2); break; case ARRAY_TYPE: { tree d1 = TYPE_DOMAIN (t1); tree d2 = TYPE_DOMAIN (t2); bool d1_variable, d2_variable; bool d1_zero, d2_zero; val = 1; /* Target types must match incl. qualifiers. */ if (TREE_TYPE (t1) != TREE_TYPE (t2) && 0 == (val = comptypes (TREE_TYPE (t1), TREE_TYPE (t2)))) return 0; /* Sizes must match unless one is missing or variable. */ if (d1 == 0 || d2 == 0 || d1 == d2) break; d1_zero = !TYPE_MAX_VALUE (d1); d2_zero = !TYPE_MAX_VALUE (d2); d1_variable = (!d1_zero && (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST || TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST)); d2_variable = (!d2_zero && (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST || TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST)); if (d1_variable || d2_variable) break; if (d1_zero && d2_zero) break; if (d1_zero || d2_zero || !tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2)) || !tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2))) val = 0; break; } case RECORD_TYPE: /* We are dealing with two distinct structs. In assorted Objective-C corner cases, however, these can still be deemed equivalent. */ if (c_dialect_objc () && objc_comptypes (t1, t2, 0) == 1) val = 1; case ENUMERAL_TYPE: case UNION_TYPE: if (val != 1 && !same_translation_unit_p (t1, t2)) val = tagged_types_tu_compatible_p (t1, t2); break; case VECTOR_TYPE: val = TYPE_VECTOR_SUBPARTS (t1) == TYPE_VECTOR_SUBPARTS (t2) && comptypes (TREE_TYPE (t1), TREE_TYPE (t2)); break; default: break; } return attrval == 2 && val == 1 ? 2 : val; } /* Return 1 if TTL and TTR are pointers to types that are equivalent, ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it to 1 or 0 depending if the check of the pointer types is meant to be reflexive or not (typically, assignments are not reflexive, while comparisons are reflexive). */ static int comp_target_types (tree ttl, tree ttr, int reflexive) { int val; tree mvl, mvr; /* Give objc_comptypes a crack at letting these types through. */ if ((val = objc_comptypes (ttl, ttr, reflexive)) >= 0) return val; /* Do not lose qualifiers on element types of array types that are pointer targets by taking their TYPE_MAIN_VARIANT. */ mvl = TREE_TYPE (ttl); mvr = TREE_TYPE (ttr); if (TREE_CODE (mvl) != ARRAY_TYPE) mvl = TYPE_MAIN_VARIANT (mvl); if (TREE_CODE (mvr) != ARRAY_TYPE) mvr = TYPE_MAIN_VARIANT (mvr); val = comptypes (mvl, mvr); if (val == 2 && pedantic) pedwarn ("types are not quite compatible"); return val; } /* Subroutines of `comptypes'. */ /* Determine whether two trees derive from the same translation unit. If the CONTEXT chain ends in a null, that tree's context is still being parsed, so if two trees have context chains ending in null, they're in the same translation unit. */ int same_translation_unit_p (tree t1, tree t2) { while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL) switch (TREE_CODE_CLASS (TREE_CODE (t1))) { case tcc_declaration: t1 = DECL_CONTEXT (t1); break; case tcc_type: t1 = TYPE_CONTEXT (t1); break; case tcc_exceptional: t1 = BLOCK_SUPERCONTEXT (t1); break; /* assume block */ default: gcc_unreachable (); } while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL) switch (TREE_CODE_CLASS (TREE_CODE (t2))) { case tcc_declaration: t2 = DECL_CONTEXT (t2); break; case tcc_type: t2 = TYPE_CONTEXT (t2); break; case tcc_exceptional: t2 = BLOCK_SUPERCONTEXT (t2); break; /* assume block */ default: gcc_unreachable (); } return t1 == t2; } /* The C standard says that two structures in different translation units are compatible with each other only if the types of their fields are compatible (among other things). So, consider two copies of this structure: */ struct tagged_tu_seen { const struct tagged_tu_seen * next; tree t1; tree t2; }; /* Can they be compatible with each other? We choose to break the recursion by allowing those types to be compatible. */ static const struct tagged_tu_seen * tagged_tu_seen_base; /* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are compatible. If the two types are not the same (which has been checked earlier), this can only happen when multiple translation units are being compiled. See C99 6.2.7 paragraph 1 for the exact rules. */ static int tagged_types_tu_compatible_p (tree t1, tree t2) { tree s1, s2; bool needs_warning = false; /* We have to verify that the tags of the types are the same. This is harder than it looks because this may be a typedef, so we have to go look at the original type. It may even be a typedef of a typedef... In the case of compiler-created builtin structs the TYPE_DECL may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */ while (TYPE_NAME (t1) && TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL && DECL_ORIGINAL_TYPE (TYPE_NAME (t1))) t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1)); while (TYPE_NAME (t2) && TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL && DECL_ORIGINAL_TYPE (TYPE_NAME (t2))) t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2)); /* C90 didn't have the requirement that the two tags be the same. */ if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2)) return 0; /* C90 didn't say what happened if one or both of the types were incomplete; we choose to follow C99 rules here, which is that they are compatible. */ if (TYPE_SIZE (t1) == NULL || TYPE_SIZE (t2) == NULL) return 1; { const struct tagged_tu_seen * tts_i; for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next) if (tts_i->t1 == t1 && tts_i->t2 == t2) return 1; } switch (TREE_CODE (t1)) { case ENUMERAL_TYPE: { /* Speed up the case where the type values are in the same order. */ tree tv1 = TYPE_VALUES (t1); tree tv2 = TYPE_VALUES (t2); if (tv1 == tv2) return 1; for (;tv1 && tv2; tv1 = TREE_CHAIN (tv1), tv2 = TREE_CHAIN (tv2)) { if (TREE_PURPOSE (tv1) != TREE_PURPOSE (tv2)) break; if (simple_cst_equal (TREE_VALUE (tv1), TREE_VALUE (tv2)) != 1) return 0; } if (tv1 == NULL_TREE && tv2 == NULL_TREE) return 1; if (tv1 == NULL_TREE || tv2 == NULL_TREE) return 0; if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2))) return 0; for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1)) { s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2)); if (s2 == NULL || simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1) return 0; } return 1; } case UNION_TYPE: { if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2))) return 0; for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1)) { bool ok = false; struct tagged_tu_seen tts; tts.next = tagged_tu_seen_base; tts.t1 = t1; tts.t2 = t2; tagged_tu_seen_base = &tts; if (DECL_NAME (s1) != NULL) for (s2 = TYPE_FIELDS (t2); s2; s2 = TREE_CHAIN (s2)) if (DECL_NAME (s1) == DECL_NAME (s2)) { int result; result = comptypes (TREE_TYPE (s1), TREE_TYPE (s2)); if (result == 0) break; if (result == 2) needs_warning = true; if (TREE_CODE (s1) == FIELD_DECL && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1), DECL_FIELD_BIT_OFFSET (s2)) != 1) break; ok = true; break; } tagged_tu_seen_base = tts.next; if (!ok) return 0; } return needs_warning ? 2 : 1; } case RECORD_TYPE: { struct tagged_tu_seen tts; tts.next = tagged_tu_seen_base; tts.t1 = t1; tts.t2 = t2; tagged_tu_seen_base = &tts; for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2); s1 && s2; s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2)) { int result; if (TREE_CODE (s1) != TREE_CODE (s2) || DECL_NAME (s1) != DECL_NAME (s2)) break; result = comptypes (TREE_TYPE (s1), TREE_TYPE (s2)); if (result == 0) break; if (result == 2) needs_warning = true; if (TREE_CODE (s1) == FIELD_DECL && simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1), DECL_FIELD_BIT_OFFSET (s2)) != 1) break; } tagged_tu_seen_base = tts.next; if (s1 && s2) return 0; return needs_warning ? 2 : 1; } default: gcc_unreachable (); } } /* Return 1 if two function types F1 and F2 are compatible. If either type specifies no argument types, the other must specify a fixed number of self-promoting arg types. Otherwise, if one type specifies only the number of arguments, the other must specify that number of self-promoting arg types. Otherwise, the argument types must match. */ static int function_types_compatible_p (tree f1, tree f2) { tree args1, args2; /* 1 if no need for warning yet, 2 if warning cause has been seen. */ int val = 1; int val1; tree ret1, ret2; ret1 = TREE_TYPE (f1); ret2 = TREE_TYPE (f2); /* 'volatile' qualifiers on a function's return type used to mean the function is noreturn. */ if (TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2)) pedwarn ("function return types not compatible due to %"); if (TYPE_VOLATILE (ret1)) ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1), TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE); if (TYPE_VOLATILE (ret2)) ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2), TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE); val = comptypes (ret1, ret2); if (val == 0) return 0; args1 = TYPE_ARG_TYPES (f1); args2 = TYPE_ARG_TYPES (f2); /* An unspecified parmlist matches any specified parmlist whose argument types don't need default promotions. */ if (args1 == 0) { if (!self_promoting_args_p (args2)) return 0; /* If one of these types comes from a non-prototype fn definition, compare that with the other type's arglist. If they don't match, ask for a warning (but no error). */ if (TYPE_ACTUAL_ARG_TYPES (f1) && 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1))) val = 2; return val; } if (args2 == 0) { if (!self_promoting_args_p (args1)) return 0; if (TYPE_ACTUAL_ARG_TYPES (f2) && 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2))) val = 2; return val; } /* Both types have argument lists: compare them and propagate results. */ val1 = type_lists_compatible_p (args1, args2); return val1 != 1 ? val1 : val; } /* Check two lists of types for compatibility, returning 0 for incompatible, 1 for compatible, or 2 for compatible with warning. */ static int type_lists_compatible_p (tree args1, tree args2) { /* 1 if no need for warning yet, 2 if warning cause has been seen. */ int val = 1; int newval = 0; while (1) { tree a1, mv1, a2, mv2; if (args1 == 0 && args2 == 0) return val; /* If one list is shorter than the other, they fail to match. */ if (args1 == 0 || args2 == 0) return 0; mv1 = a1 = TREE_VALUE (args1); mv2 = a2 = TREE_VALUE (args2); if (mv1 && mv1 != error_mark_node && TREE_CODE (mv1) != ARRAY_TYPE) mv1 = TYPE_MAIN_VARIANT (mv1); if (mv2 && mv2 != error_mark_node && TREE_CODE (mv2) != ARRAY_TYPE) mv2 = TYPE_MAIN_VARIANT (mv2); /* A null pointer instead of a type means there is supposed to be an argument but nothing is specified about what type it has. So match anything that self-promotes. */ if (a1 == 0) { if (c_type_promotes_to (a2) != a2) return 0; } else if (a2 == 0) { if (c_type_promotes_to (a1) != a1) return 0; } /* If one of the lists has an error marker, ignore this arg. */ else if (TREE_CODE (a1) == ERROR_MARK || TREE_CODE (a2) == ERROR_MARK) ; else if (!(newval = comptypes (mv1, mv2))) { /* Allow wait (union {union wait *u; int *i} *) and wait (union wait *) to be compatible. */ if (TREE_CODE (a1) == UNION_TYPE && (TYPE_NAME (a1) == 0 || TYPE_TRANSPARENT_UNION (a1)) && TREE_CODE (TYPE_SIZE (a1)) == INTEGER_CST && tree_int_cst_equal (TYPE_SIZE (a1), TYPE_SIZE (a2))) { tree memb; for (memb = TYPE_FIELDS (a1); memb; memb = TREE_CHAIN (memb)) { tree mv3 = TREE_TYPE (memb); if (mv3 && mv3 != error_mark_node && TREE_CODE (mv3) != ARRAY_TYPE) mv3 = TYPE_MAIN_VARIANT (mv3); if (comptypes (mv3, mv2)) break; } if (memb == 0) return 0; } else if (TREE_CODE (a2) == UNION_TYPE && (TYPE_NAME (a2) == 0 || TYPE_TRANSPARENT_UNION (a2)) && TREE_CODE (TYPE_SIZE (a2)) == INTEGER_CST && tree_int_cst_equal (TYPE_SIZE (a2), TYPE_SIZE (a1))) { tree memb; for (memb = TYPE_FIELDS (a2); memb; memb = TREE_CHAIN (memb)) { tree mv3 = TREE_TYPE (memb); if (mv3 && mv3 != error_mark_node && TREE_CODE (mv3) != ARRAY_TYPE) mv3 = TYPE_MAIN_VARIANT (mv3); if (comptypes (mv3, mv1)) break; } if (memb == 0) return 0; } else return 0; } /* comptypes said ok, but record if it said to warn. */ if (newval > val) val = newval; args1 = TREE_CHAIN (args1); args2 = TREE_CHAIN (args2); } } /* Compute the size to increment a pointer by. */ static tree c_size_in_bytes (tree type) { enum tree_code code = TREE_CODE (type); if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK) return size_one_node; if (!COMPLETE_OR_VOID_TYPE_P (type)) { error ("arithmetic on pointer to an incomplete type"); return size_one_node; } /* Convert in case a char is more than one unit. */ return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type), size_int (TYPE_PRECISION (char_type_node) / BITS_PER_UNIT)); } /* Return either DECL or its known constant value (if it has one). */ tree decl_constant_value (tree decl) { if (/* Don't change a variable array bound or initial value to a constant in a place where a variable is invalid. Note that DECL_INITIAL isn't valid for a PARM_DECL. */ current_function_decl != 0 && TREE_CODE (decl) != PARM_DECL && !TREE_THIS_VOLATILE (decl) && TREE_READONLY (decl) && DECL_INITIAL (decl) != 0 && TREE_CODE (DECL_INITIAL (decl)) != ERROR_MARK /* This is invalid if initial value is not constant. If it has either a function call, a memory reference, or a variable, then re-evaluating it could give different results. */ && TREE_CONSTANT (DECL_INITIAL (decl)) /* Check for cases where this is sub-optimal, even though valid. */ && TREE_CODE (DECL_INITIAL (decl)) != CONSTRUCTOR) return DECL_INITIAL (decl); return decl; } /* Return either DECL or its known constant value (if it has one), but return DECL if pedantic or DECL has mode BLKmode. This is for bug-compatibility with the old behavior of decl_constant_value (before GCC 3.0); every use of this function is a bug and it should be removed before GCC 3.1. It is not appropriate to use pedantic in a way that affects optimization, and BLKmode is probably not the right test for avoiding misoptimizations either. */ static tree decl_constant_value_for_broken_optimization (tree decl) { if (pedantic || DECL_MODE (decl) == BLKmode) return decl; else return decl_constant_value (decl); } /* Perform the default conversion of arrays and functions to pointers. Return the result of converting EXP. For any other expression, just return EXP. */ static tree default_function_array_conversion (tree exp) { tree orig_exp; tree type = TREE_TYPE (exp); enum tree_code code = TREE_CODE (type); int not_lvalue = 0; /* Strip NON_LVALUE_EXPRs and no-op conversions, since we aren't using as an lvalue. Do not use STRIP_NOPS here! It will remove conversions from pointer to integer and cause infinite recursion. */ orig_exp = exp; while (TREE_CODE (exp) == NON_LVALUE_EXPR || (TREE_CODE (exp) == NOP_EXPR && TREE_TYPE (TREE_OPERAND (exp, 0)) == TREE_TYPE (exp))) { if (TREE_CODE (exp) == NON_LVALUE_EXPR) not_lvalue = 1; exp = TREE_OPERAND (exp, 0); } if (TREE_NO_WARNING (orig_exp)) TREE_NO_WARNING (exp) = 1; if (code == FUNCTION_TYPE) { return build_unary_op (ADDR_EXPR, exp, 0); } if (code == ARRAY_TYPE) { tree adr; tree restype = TREE_TYPE (type); tree ptrtype; int constp = 0; int volatilep = 0; int lvalue_array_p; if (REFERENCE_CLASS_P (exp) || DECL_P (exp)) { constp = TREE_READONLY (exp); volatilep = TREE_THIS_VOLATILE (exp); } if (TYPE_QUALS (type) || constp || volatilep) restype = c_build_qualified_type (restype, TYPE_QUALS (type) | (constp * TYPE_QUAL_CONST) | (volatilep * TYPE_QUAL_VOLATILE)); if (TREE_CODE (exp) == INDIRECT_REF) return convert (build_pointer_type (restype), TREE_OPERAND (exp, 0)); if (TREE_CODE (exp) == COMPOUND_EXPR) { tree op1 = default_conversion (TREE_OPERAND (exp, 1)); return build2 (COMPOUND_EXPR, TREE_TYPE (op1), TREE_OPERAND (exp, 0), op1); } lvalue_array_p = !not_lvalue && lvalue_p (exp); if (!flag_isoc99 && !lvalue_array_p) { /* Before C99, non-lvalue arrays do not decay to pointers. Normally, using such an array would be invalid; but it can be used correctly inside sizeof or as a statement expression. Thus, do not give an error here; an error will result later. */ return exp; } ptrtype = build_pointer_type (restype); if (TREE_CODE (exp) == VAR_DECL) { /* We are making an ADDR_EXPR of ptrtype. This is a valid ADDR_EXPR because it's the best way of representing what happens in C when we take the address of an array and place it in a pointer to the element type. */ adr = build1 (ADDR_EXPR, ptrtype, exp); if (!c_mark_addressable (exp)) return error_mark_node; TREE_SIDE_EFFECTS (adr) = 0; /* Default would be, same as EXP. */ return adr; } /* This way is better for a COMPONENT_REF since it can simplify the offset for a component. */ adr = build_unary_op (ADDR_EXPR, exp, 1); return convert (ptrtype, adr); } return exp; } /* EXP is an expression of integer type. Apply the integer promotions to it and return the promoted value. */ tree perform_integral_promotions (tree exp) { tree type = TREE_TYPE (exp); enum tree_code code = TREE_CODE (type); gcc_assert (INTEGRAL_TYPE_P (type)); /* Normally convert enums to int, but convert wide enums to something wider. */ if (code == ENUMERAL_TYPE) { type = c_common_type_for_size (MAX (TYPE_PRECISION (type), TYPE_PRECISION (integer_type_node)), ((TYPE_PRECISION (type) >= TYPE_PRECISION (integer_type_node)) && TYPE_UNSIGNED (type))); return convert (type, exp); } /* ??? This should no longer be needed now bit-fields have their proper types. */ if (TREE_CODE (exp) == COMPONENT_REF && DECL_C_BIT_FIELD (TREE_OPERAND (exp, 1)) /* If it's thinner than an int, promote it like a c_promoting_integer_type_p, otherwise leave it alone. */ && 0 > compare_tree_int (DECL_SIZE (TREE_OPERAND (exp, 1)), TYPE_PRECISION (integer_type_node))) return convert (integer_type_node, exp); if (c_promoting_integer_type_p (type)) { /* Preserve unsignedness if not really getting any wider. */ if (TYPE_UNSIGNED (type) && TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)) return convert (unsigned_type_node, exp); return convert (integer_type_node, exp); } return exp; } /* Perform default promotions for C data used in expressions. Arrays and functions are converted to pointers; enumeral types or short or char, to int. In addition, manifest constants symbols are replaced by their values. */ tree default_conversion (tree exp) { tree orig_exp; tree type = TREE_TYPE (exp); enum tree_code code = TREE_CODE (type); if (code == FUNCTION_TYPE || code == ARRAY_TYPE) return default_function_array_conversion (exp); /* Constants can be used directly unless they're not loadable. */ if (TREE_CODE (exp) == CONST_DECL) exp = DECL_INITIAL (exp); /* Replace a nonvolatile const static variable with its value unless it is an array, in which case we must be sure that taking the address of the array produces consistent results. */ else if (optimize && TREE_CODE (exp) == VAR_DECL && code != ARRAY_TYPE) { exp = decl_constant_value_for_broken_optimization (exp); type = TREE_TYPE (exp); } /* Strip no-op conversions. */ orig_exp = exp; STRIP_TYPE_NOPS (exp); if (TREE_NO_WARNING (orig_exp)) TREE_NO_WARNING (exp) = 1; if (INTEGRAL_TYPE_P (type)) return perform_integral_promotions (exp); if (code == VOID_TYPE) { error ("void value not ignored as it ought to be"); return error_mark_node; } return exp; } /* Look up COMPONENT in a structure or union DECL. If the component name is not found, returns NULL_TREE. Otherwise, the return value is a TREE_LIST, with each TREE_VALUE a FIELD_DECL stepping down the chain to the component, which is in the last TREE_VALUE of the list. Normally the list is of length one, but if the component is embedded within (nested) anonymous structures or unions, the list steps down the chain to the component. */ static tree lookup_field (tree decl, tree component) { tree type = TREE_TYPE (decl); tree field; /* If TYPE_LANG_SPECIFIC is set, then it is a sorted array of pointers to the field elements. Use a binary search on this array to quickly find the element. Otherwise, do a linear search. TYPE_LANG_SPECIFIC will always be set for structures which have many elements. */ if (TYPE_LANG_SPECIFIC (type) && TYPE_LANG_SPECIFIC (type)->s) { int bot, top, half; tree *field_array = &TYPE_LANG_SPECIFIC (type)->s->elts[0]; field = TYPE_FIELDS (type); bot = 0; top = TYPE_LANG_SPECIFIC (type)->s->len; while (top - bot > 1) { half = (top - bot + 1) >> 1; field = field_array[bot+half]; if (DECL_NAME (field) == NULL_TREE) { /* Step through all anon unions in linear fashion. */ while (DECL_NAME (field_array[bot]) == NULL_TREE) { field = field_array[bot++]; if (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE) { tree anon = lookup_field (field, component); if (anon) return tree_cons (NULL_TREE, field, anon); } } /* Entire record is only anon unions. */ if (bot > top) return NULL_TREE; /* Restart the binary search, with new lower bound. */ continue; } if (DECL_NAME (field) == component) break; if (DECL_NAME (field) < component) bot += half; else top = bot + half; } if (DECL_NAME (field_array[bot]) == component) field = field_array[bot]; else if (DECL_NAME (field) != component) return NULL_TREE; } else { for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) { if (DECL_NAME (field) == NULL_TREE && (TREE_CODE (TREE_TYPE (field)) == RECORD_TYPE || TREE_CODE (TREE_TYPE (field)) == UNION_TYPE)) { tree anon = lookup_field (field, component); if (anon) return tree_cons (NULL_TREE, field, anon); } if (DECL_NAME (field) == component) break; } if (field == NULL_TREE) return NULL_TREE; } return tree_cons (NULL_TREE, field, NULL_TREE); } /* Make an expression to refer to the COMPONENT field of structure or union value DATUM. COMPONENT is an IDENTIFIER_NODE. */ tree build_component_ref (tree datum, tree component) { tree type = TREE_TYPE (datum); enum tree_code code = TREE_CODE (type); tree field = NULL; tree ref; if (!objc_is_public (datum, component)) return error_mark_node; /* See if there is a field or component with name COMPONENT. */ if (code == RECORD_TYPE || code == UNION_TYPE) { if (!COMPLETE_TYPE_P (type)) { c_incomplete_type_error (NULL_TREE, type); return error_mark_node; } field = lookup_field (datum, component); if (!field) { error ("%qT has no member named %qE", type, component); return error_mark_node; } /* Chain the COMPONENT_REFs if necessary down to the FIELD. This might be better solved in future the way the C++ front end does it - by giving the anonymous entities each a separate name and type, and then have build_component_ref recursively call itself. We can't do that here. */ do { tree subdatum = TREE_VALUE (field); if (TREE_TYPE (subdatum) == error_mark_node) return error_mark_node; ref = build3 (COMPONENT_REF, TREE_TYPE (subdatum), datum, subdatum, NULL_TREE); if (TREE_READONLY (datum) || TREE_READONLY (subdatum)) TREE_READONLY (ref) = 1; if (TREE_THIS_VOLATILE (datum) || TREE_THIS_VOLATILE (subdatum)) TREE_THIS_VOLATILE (ref) = 1; if (TREE_DEPRECATED (subdatum)) warn_deprecated_use (subdatum); datum = ref; field = TREE_CHAIN (field); } while (field); return ref; } else if (code != ERROR_MARK) error ("request for member %qE in something not a structure or union", component); return error_mark_node; } /* Given an expression PTR for a pointer, return an expression for the value pointed to. ERRORSTRING is the name of the operator to appear in error messages. */ tree build_indirect_ref (tree ptr, const char *errorstring) { tree pointer = default_conversion (ptr); tree type = TREE_TYPE (pointer); if (TREE_CODE (type) == POINTER_TYPE) { if (TREE_CODE (pointer) == ADDR_EXPR && (TREE_TYPE (TREE_OPERAND (pointer, 0)) == TREE_TYPE (type))) return TREE_OPERAND (pointer, 0); else { tree t = TREE_TYPE (type); tree mvt = t; tree ref; if (TREE_CODE (mvt) != ARRAY_TYPE) mvt = TYPE_MAIN_VARIANT (mvt); ref = build1 (INDIRECT_REF, mvt, pointer); if (!COMPLETE_OR_VOID_TYPE_P (t) && TREE_CODE (t) != ARRAY_TYPE) { error ("dereferencing pointer to incomplete type"); return error_mark_node; } if (VOID_TYPE_P (t) && skip_evaluation == 0) warning ("dereferencing % pointer"); /* We *must* set TREE_READONLY when dereferencing a pointer to const, so that we get the proper error message if the result is used to assign to. Also, &* is supposed to be a no-op. And ANSI C seems to specify that the type of the result should be the const type. */ /* A de-reference of a pointer to const is not a const. It is valid to change it via some other pointer. */ TREE_READONLY (ref) = TYPE_READONLY (t); TREE_SIDE_EFFECTS (ref) = TYPE_VOLATILE (t) || TREE_SIDE_EFFECTS (pointer); TREE_THIS_VOLATILE (ref) = TYPE_VOLATILE (t); return ref; } } else if (TREE_CODE (pointer) != ERROR_MARK) error ("invalid type argument of %qs", errorstring); return error_mark_node; } /* This handles expressions of the form "a[i]", which denotes an array reference. This is logically equivalent in C to *(a+i), but we may do it differently. If A is a variable or a member, we generate a primitive ARRAY_REF. This avoids forcing the array out of registers, and can work on arrays that are not lvalues (for example, members of structures returned by functions). */ tree build_array_ref (tree array, tree index) { bool swapped = false; if (TREE_TYPE (array) == error_mark_node || TREE_TYPE (index) == error_mark_node) return error_mark_node; if (TREE_CODE (TREE_TYPE (array)) != ARRAY_TYPE && TREE_CODE (TREE_TYPE (array)) != POINTER_TYPE) { tree temp; if (TREE_CODE (TREE_TYPE (index)) != ARRAY_TYPE && TREE_CODE (TREE_TYPE (index)) != POINTER_TYPE) { error ("subscripted value is neither array nor pointer"); return error_mark_node; } temp = array; array = index; index = temp; swapped = true; } if (!INTEGRAL_TYPE_P (TREE_TYPE (index))) { error ("array subscript is not an integer"); return error_mark_node; } if (TREE_CODE (TREE_TYPE (TREE_TYPE (array))) == FUNCTION_TYPE) { error ("subscripted value is pointer to function"); return error_mark_node; } /* Subscripting with type char is likely to lose on a machine where chars are signed. So warn on any machine, but optionally. Don't warn for unsigned char since that type is safe. Don't warn for signed char because anyone who uses that must have done so deliberately. ??? Existing practice has also been to warn only when the char index is syntactically the index, not for char[array]. */ if (warn_char_subscripts && !swapped && TYPE_MAIN_VARIANT (TREE_TYPE (index)) == char_type_node) warning ("array subscript has type %"); /* Apply default promotions *after* noticing character types. */ index = default_conversion (index); gcc_assert (TREE_CODE (TREE_TYPE (index)) == INTEGER_TYPE); if (TREE_CODE (TREE_TYPE (array)) == ARRAY_TYPE) { tree rval, type; /* An array that is indexed by a non-constant cannot be stored in a register; we must be able to do address arithmetic on its address. Likewise an array of elements of variable size. */ if (TREE_CODE (index) != INTEGER_CST || (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (array))) && TREE_CODE (TYPE_SIZE (TREE_TYPE (TREE_TYPE (array)))) != INTEGER_CST)) { if (!c_mark_addressable (array)) return error_mark_node; } /* An array that is indexed by a constant value which is not within the array bounds cannot be stored in a register either; because we would get a crash in store_bit_field/extract_bit_field when trying to access a non-existent part of the register. */ if (TREE_CODE (index) == INTEGER_CST && TYPE_DOMAIN (TREE_TYPE (array)) && !int_fits_type_p (index, TYPE_DOMAIN (TREE_TYPE (array)))) { if (!c_mark_addressable (array)) return error_mark_node; } if (pedantic) { tree foo = array; while (TREE_CODE (foo) == COMPONENT_REF) foo = TREE_OPERAND (foo, 0); if (TREE_CODE (foo) == VAR_DECL && C_DECL_REGISTER (foo)) pedwarn ("ISO C forbids subscripting % array"); else if (!flag_isoc99 && !lvalue_p (foo)) pedwarn ("ISO C90 forbids subscripting non-lvalue array"); } type = TREE_TYPE (TREE_TYPE (array)); if (TREE_CODE (type) != ARRAY_TYPE) type = TYPE_MAIN_VARIANT (type); rval = build4 (ARRAY_REF, type, array, index, NULL_TREE, NULL_TREE); /* Array ref is const/volatile if the array elements are or if the array is. */ TREE_READONLY (rval) |= (TYPE_READONLY (TREE_TYPE (TREE_TYPE (array))) | TREE_READONLY (array)); TREE_SIDE_EFFECTS (rval) |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) | TREE_SIDE_EFFECTS (array)); TREE_THIS_VOLATILE (rval) |= (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (array))) /* This was added by rms on 16 Nov 91. It fixes vol struct foo *a; a->elts[1] in an inline function. Hope it doesn't break something else. */ | TREE_THIS_VOLATILE (array)); return require_complete_type (fold (rval)); } else { tree ar = default_conversion (array); if (ar == error_mark_node) return ar; gcc_assert (TREE_CODE (TREE_TYPE (ar)) == POINTER_TYPE); gcc_assert (TREE_CODE (TREE_TYPE (TREE_TYPE (ar))) != FUNCTION_TYPE); return build_indirect_ref (build_binary_op (PLUS_EXPR, ar, index, 0), "array indexing"); } } /* Build an external reference to identifier ID. FUN indicates whether this will be used for a function call. LOC is the source location of the identifier. */ tree build_external_ref (tree id, int fun, location_t loc) { tree ref; tree decl = lookup_name (id); /* In Objective-C, an instance variable (ivar) may be preferred to whatever lookup_name() found. */ decl = objc_lookup_ivar (decl, id); if (decl && decl != error_mark_node) ref = decl; else if (fun) /* Implicit function declaration. */ ref = implicitly_declare (id); else if (decl == error_mark_node) /* Don't complain about something that's already been complained about. */ return error_mark_node; else { undeclared_variable (id, loc); return error_mark_node; } if (TREE_TYPE (ref) == error_mark_node) return error_mark_node; if (TREE_DEPRECATED (ref)) warn_deprecated_use (ref); if (!skip_evaluation) assemble_external (ref); TREE_USED (ref) = 1; if (TREE_CODE (ref) == FUNCTION_DECL && !in_alignof) { if (!in_sizeof && !in_typeof) C_DECL_USED (ref) = 1; else if (DECL_INITIAL (ref) == 0 && DECL_EXTERNAL (ref) && !TREE_PUBLIC (ref)) record_maybe_used_decl (ref); } if (TREE_CODE (ref) == CONST_DECL) { ref = DECL_INITIAL (ref); TREE_CONSTANT (ref) = 1; TREE_INVARIANT (ref) = 1; } else if (current_function_decl != 0 && !DECL_FILE_SCOPE_P (current_function_decl) && (TREE_CODE (ref) == VAR_DECL || TREE_CODE (ref) == PARM_DECL || TREE_CODE (ref) == FUNCTION_DECL)) { tree context = decl_function_context (ref); if (context != 0 && context != current_function_decl) DECL_NONLOCAL (ref) = 1; } return ref; } /* Record details of decls possibly used inside sizeof or typeof. */ struct maybe_used_decl { /* The decl. */ tree decl; /* The level seen at (in_sizeof + in_typeof). */ int level; /* The next one at this level or above, or NULL. */ struct maybe_used_decl *next; }; static struct maybe_used_decl *maybe_used_decls; /* Record that DECL, an undefined static function reference seen inside sizeof or typeof, might be used if the operand of sizeof is a VLA type or the operand of typeof is a variably modified type. */ static void record_maybe_used_decl (tree decl) { struct maybe_used_decl *t = XOBNEW (&parser_obstack, struct maybe_used_decl); t->decl = decl; t->level = in_sizeof + in_typeof; t->next = maybe_used_decls; maybe_used_decls = t; } /* Pop the stack of decls possibly used inside sizeof or typeof. If USED is false, just discard them. If it is true, mark them used (if no longer inside sizeof or typeof) or move them to the next level up (if still inside sizeof or typeof). */ void pop_maybe_used (bool used) { struct maybe_used_decl *p = maybe_used_decls; int cur_level = in_sizeof + in_typeof; while (p && p->level > cur_level) { if (used) { if (cur_level == 0) C_DECL_USED (p->decl) = 1; else p->level = cur_level; } p = p->next; } if (!used || cur_level == 0) maybe_used_decls = p; } /* Return the result of sizeof applied to EXPR. */ struct c_expr c_expr_sizeof_expr (struct c_expr expr) { struct c_expr ret; if (expr.value == error_mark_node) { ret.value = error_mark_node; ret.original_code = ERROR_MARK; pop_maybe_used (false); } else { ret.value = c_sizeof (TREE_TYPE (expr.value)); ret.original_code = ERROR_MARK; pop_maybe_used (C_TYPE_VARIABLE_SIZE (TREE_TYPE (expr.value))); } return ret; } /* Return the result of sizeof applied to T, a structure for the type name passed to sizeof (rather than the type itself). */ struct c_expr c_expr_sizeof_type (struct c_type_name *t) { tree type; struct c_expr ret; type = groktypename (t); ret.value = c_sizeof (type); ret.original_code = ERROR_MARK; pop_maybe_used (C_TYPE_VARIABLE_SIZE (type)); return ret; } /* Build a function call to function FUNCTION with parameters PARAMS. PARAMS is a list--a chain of TREE_LIST nodes--in which the TREE_VALUE of each node is a parameter-expression. FUNCTION's data type may be a function type or a pointer-to-function. */ tree build_function_call (tree function, tree params) { tree fntype, fundecl = 0; tree coerced_params; tree name = NULL_TREE, result; tree tem; /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ STRIP_TYPE_NOPS (function); /* Convert anything with function type to a pointer-to-function. */ if (TREE_CODE (function) == FUNCTION_DECL) { name = DECL_NAME (function); /* Differs from default_conversion by not setting TREE_ADDRESSABLE (because calling an inline function does not mean the function needs to be separately compiled). */ fntype = build_type_variant (TREE_TYPE (function), TREE_READONLY (function), TREE_THIS_VOLATILE (function)); fundecl = function; function = build1 (ADDR_EXPR, build_pointer_type (fntype), function); } else function = default_conversion (function); fntype = TREE_TYPE (function); if (TREE_CODE (fntype) == ERROR_MARK) return error_mark_node; if (!(TREE_CODE (fntype) == POINTER_TYPE && TREE_CODE (TREE_TYPE (fntype)) == FUNCTION_TYPE)) { error ("called object %qE is not a function", function); return error_mark_node; } if (fundecl && TREE_THIS_VOLATILE (fundecl)) current_function_returns_abnormally = 1; /* fntype now gets the type of function pointed to. */ fntype = TREE_TYPE (fntype); /* Check that the function is called through a compatible prototype. If it is not, replace the call by a trap, wrapped up in a compound expression if necessary. This has the nice side-effect to prevent the tree-inliner from generating invalid assignment trees which may blow up in the RTL expander later. ??? This doesn't work for Objective-C because objc_comptypes refuses to compare function prototypes, yet the compiler appears to build calls that are flagged as invalid by C's comptypes. */ if (!c_dialect_objc () && TREE_CODE (function) == NOP_EXPR && TREE_CODE (tem = TREE_OPERAND (function, 0)) == ADDR_EXPR && TREE_CODE (tem = TREE_OPERAND (tem, 0)) == FUNCTION_DECL && !comptypes (fntype, TREE_TYPE (tem))) { tree return_type = TREE_TYPE (fntype); tree trap = build_function_call (built_in_decls[BUILT_IN_TRAP], NULL_TREE); /* This situation leads to run-time undefined behavior. We can't, therefore, simply error unless we can prove that all possible executions of the program must execute the code. */ warning ("function called through a non-compatible type"); /* We can, however, treat "undefined" any way we please. Call abort to encourage the user to fix the program. */ inform ("if this code is reached, the program will abort"); if (VOID_TYPE_P (return_type)) return trap; else { tree rhs; if (AGGREGATE_TYPE_P (return_type)) rhs = build_compound_literal (return_type, build_constructor (return_type, NULL_TREE)); else rhs = fold (build1 (NOP_EXPR, return_type, integer_zero_node)); return build2 (COMPOUND_EXPR, return_type, trap, rhs); } } /* Convert the parameters to the types declared in the function prototype, or apply default promotions. */ coerced_params = convert_arguments (TYPE_ARG_TYPES (fntype), params, function, fundecl); if (coerced_params == error_mark_node) return error_mark_node; /* Check that the arguments to the function are valid. */ check_function_arguments (TYPE_ATTRIBUTES (fntype), coerced_params); result = build3 (CALL_EXPR, TREE_TYPE (fntype), function, coerced_params, NULL_TREE); TREE_SIDE_EFFECTS (result) = 1; if (require_constant_value) { result = fold_initializer (result); if (TREE_CONSTANT (result) && (name == NULL_TREE || strncmp (IDENTIFIER_POINTER (name), "__builtin_", 10) != 0)) pedwarn_init ("initializer element is not constant"); } else result = fold (result); if (VOID_TYPE_P (TREE_TYPE (result))) return result; return require_complete_type (result); } /* Convert the argument expressions in the list VALUES to the types in the list TYPELIST. The result is a list of converted argument expressions, unless there are too few arguments in which case it is error_mark_node. If TYPELIST is exhausted, or when an element has NULL as its type, perform the default conversions. PARMLIST is the chain of parm decls for the function being called. It may be 0, if that info is not available. It is used only for generating error messages. FUNCTION is a tree for the called function. It is used only for error messages, where it is formatted with %qE. This is also where warnings about wrong number of args are generated. Both VALUES and the returned value are chains of TREE_LIST nodes with the elements of the list in the TREE_VALUE slots of those nodes. */ static tree convert_arguments (tree typelist, tree values, tree function, tree fundecl) { tree typetail, valtail; tree result = NULL; int parmnum; tree selector; /* Change pointer to function to the function itself for diagnostics. */ if (TREE_CODE (function) == ADDR_EXPR && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) function = TREE_OPERAND (function, 0); /* Handle an ObjC selector specially for diagnostics. */ selector = objc_message_selector (); /* Scan the given expressions and types, producing individual converted arguments and pushing them on RESULT in reverse order. */ for (valtail = values, typetail = typelist, parmnum = 0; valtail; valtail = TREE_CHAIN (valtail), parmnum++) { tree type = typetail ? TREE_VALUE (typetail) : 0; tree val = TREE_VALUE (valtail); tree rname = function; int argnum = parmnum + 1; const char *invalid_func_diag; if (type == void_type_node) { error ("too many arguments to function %qE", function); break; } if (selector && argnum > 2) { rname = selector; argnum -= 2; } STRIP_TYPE_NOPS (val); val = default_function_array_conversion (val); val = require_complete_type (val); if (type != 0) { /* Formal parm type is specified by a function prototype. */ tree parmval; if (type == error_mark_node || !COMPLETE_TYPE_P (type)) { error ("type of formal parameter %d is incomplete", parmnum + 1); parmval = val; } else { /* Optionally warn about conversions that differ from the default conversions. */ if (warn_conversion || warn_traditional) { unsigned int formal_prec = TYPE_PRECISION (type); if (INTEGRAL_TYPE_P (type) && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) warning ("passing argument %d of %qE as integer " "rather than floating due to prototype", argnum, rname); if (INTEGRAL_TYPE_P (type) && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) warning ("passing argument %d of %qE as integer " "rather than complex due to prototype", argnum, rname); else if (TREE_CODE (type) == COMPLEX_TYPE && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) warning ("passing argument %d of %qE as complex " "rather than floating due to prototype", argnum, rname); else if (TREE_CODE (type) == REAL_TYPE && INTEGRAL_TYPE_P (TREE_TYPE (val))) warning ("passing argument %d of %qE as floating " "rather than integer due to prototype", argnum, rname); else if (TREE_CODE (type) == COMPLEX_TYPE && INTEGRAL_TYPE_P (TREE_TYPE (val))) warning ("passing argument %d of %qE as complex " "rather than integer due to prototype", argnum, rname); else if (TREE_CODE (type) == REAL_TYPE && TREE_CODE (TREE_TYPE (val)) == COMPLEX_TYPE) warning ("passing argument %d of %qE as floating " "rather than complex due to prototype", argnum, rname); /* ??? At some point, messages should be written about conversions between complex types, but that's too messy to do now. */ else if (TREE_CODE (type) == REAL_TYPE && TREE_CODE (TREE_TYPE (val)) == REAL_TYPE) { /* Warn if any argument is passed as `float', since without a prototype it would be `double'. */ if (formal_prec == TYPE_PRECISION (float_type_node)) warning ("passing argument %d of %qE as % " "rather than % due to prototype", argnum, rname); } /* Detect integer changing in width or signedness. These warnings are only activated with -Wconversion, not with -Wtraditional. */ else if (warn_conversion && INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (val))) { tree would_have_been = default_conversion (val); tree type1 = TREE_TYPE (would_have_been); if (TREE_CODE (type) == ENUMERAL_TYPE && (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (TREE_TYPE (val)))) /* No warning if function asks for enum and the actual arg is that enum type. */ ; else if (formal_prec != TYPE_PRECISION (type1)) warning ("passing argument %d of %qE with different " "width due to prototype", argnum, rname); else if (TYPE_UNSIGNED (type) == TYPE_UNSIGNED (type1)) ; /* Don't complain if the formal parameter type is an enum, because we can't tell now whether the value was an enum--even the same enum. */ else if (TREE_CODE (type) == ENUMERAL_TYPE) ; else if (TREE_CODE (val) == INTEGER_CST && int_fits_type_p (val, type)) /* Change in signedness doesn't matter if a constant value is unaffected. */ ; /* If the value is extended from a narrower unsigned type, it doesn't matter whether we pass it as signed or unsigned; the value certainly is the same either way. */ else if (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type) && TYPE_UNSIGNED (TREE_TYPE (val))) ; else if (TYPE_UNSIGNED (type)) warning ("passing argument %d of %qE as unsigned " "due to prototype", argnum, rname); else warning ("passing argument %d of %qE as signed " "due to prototype", argnum, rname); } } parmval = convert_for_assignment (type, val, ic_argpass, fundecl, function, parmnum + 1); if (targetm.calls.promote_prototypes (fundecl ? TREE_TYPE (fundecl) : 0) && INTEGRAL_TYPE_P (type) && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) parmval = default_conversion (parmval); } result = tree_cons (NULL_TREE, parmval, result); } else if (TREE_CODE (TREE_TYPE (val)) == REAL_TYPE && (TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (double_type_node))) /* Convert `float' to `double'. */ result = tree_cons (NULL_TREE, convert (double_type_node, val), result); else if ((invalid_func_diag = targetm.calls.invalid_arg_for_unprototyped_fn (typelist, fundecl, val))) { error (invalid_func_diag); return error_mark_node; } else /* Convert `short' and `char' to full-size `int'. */ result = tree_cons (NULL_TREE, default_conversion (val), result); if (typetail) typetail = TREE_CHAIN (typetail); } if (typetail != 0 && TREE_VALUE (typetail) != void_type_node) { error ("too few arguments to function %qE", function); return error_mark_node; } return nreverse (result); } /* This is the entry point used by the parser for binary operators in the input. In addition to constructing the expression, we check for operands that were written with other binary operators in a way that is likely to confuse the user. */ struct c_expr parser_build_binary_op (enum tree_code code, struct c_expr arg1, struct c_expr arg2) { struct c_expr result; enum tree_code code1 = arg1.original_code; enum tree_code code2 = arg2.original_code; result.value = build_binary_op (code, arg1.value, arg2.value, 1); result.original_code = code; if (TREE_CODE (result.value) == ERROR_MARK) return result; /* Check for cases such as x+y< used in subtraction"); if (TREE_CODE (target_type) == FUNCTION_TYPE) pedwarn ("pointer to a function used in subtraction"); } /* If the conversion to ptrdiff_type does anything like widening or converting a partial to an integral mode, we get a convert_expression that is in the way to do any simplifications. (fold-const.c doesn't know that the extra bits won't be needed. split_tree uses STRIP_SIGN_NOPS, which leaves conversions to a different mode in place.) So first try to find a common term here 'by hand'; we want to cover at least the cases that occur in legal static initializers. */ con0 = TREE_CODE (op0) == NOP_EXPR ? TREE_OPERAND (op0, 0) : op0; con1 = TREE_CODE (op1) == NOP_EXPR ? TREE_OPERAND (op1, 0) : op1; if (TREE_CODE (con0) == PLUS_EXPR) { lit0 = TREE_OPERAND (con0, 1); con0 = TREE_OPERAND (con0, 0); } else lit0 = integer_zero_node; if (TREE_CODE (con1) == PLUS_EXPR) { lit1 = TREE_OPERAND (con1, 1); con1 = TREE_OPERAND (con1, 0); } else lit1 = integer_zero_node; if (operand_equal_p (con0, con1, 0)) { op0 = lit0; op1 = lit1; } /* First do the subtraction as integers; then drop through to build the divide operator. Do not do default conversions on the minus operator in case restype is a short type. */ op0 = build_binary_op (MINUS_EXPR, convert (restype, op0), convert (restype, op1), 0); /* This generates an error if op1 is pointer to incomplete type. */ if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (TREE_TYPE (orig_op1)))) error ("arithmetic on pointer to an incomplete type"); /* This generates an error if op0 is pointer to incomplete type. */ op1 = c_size_in_bytes (target_type); /* Divide by the size, in easiest possible way. */ return fold (build2 (EXACT_DIV_EXPR, restype, op0, convert (restype, op1))); } /* Construct and perhaps optimize a tree representation for a unary operation. CODE, a tree_code, specifies the operation and XARG is the operand. For any CODE other than ADDR_EXPR, FLAG nonzero suppresses the default promotions (such as from short to int). For ADDR_EXPR, the default promotions are not applied; FLAG nonzero allows non-lvalues; this is only used to handle conversion of non-lvalue arrays to pointers in C99. */ tree build_unary_op (enum tree_code code, tree xarg, int flag) { /* No default_conversion here. It causes trouble for ADDR_EXPR. */ tree arg = xarg; tree argtype = 0; enum tree_code typecode = TREE_CODE (TREE_TYPE (arg)); tree val; int noconvert = flag; if (typecode == ERROR_MARK) return error_mark_node; if (typecode == ENUMERAL_TYPE || typecode == BOOLEAN_TYPE) typecode = INTEGER_TYPE; switch (code) { case CONVERT_EXPR: /* This is used for unary plus, because a CONVERT_EXPR is enough to prevent anybody from looking inside for associativity, but won't generate any code. */ if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE || typecode == COMPLEX_TYPE || typecode == VECTOR_TYPE)) { error ("wrong type argument to unary plus"); return error_mark_node; } else if (!noconvert) arg = default_conversion (arg); arg = non_lvalue (arg); break; case NEGATE_EXPR: if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE || typecode == COMPLEX_TYPE || typecode == VECTOR_TYPE)) { error ("wrong type argument to unary minus"); return error_mark_node; } else if (!noconvert) arg = default_conversion (arg); break; case BIT_NOT_EXPR: if (typecode == INTEGER_TYPE || typecode == VECTOR_TYPE) { if (!noconvert) arg = default_conversion (arg); } else if (typecode == COMPLEX_TYPE) { code = CONJ_EXPR; if (pedantic) pedwarn ("ISO C does not support %<~%> for complex conjugation"); if (!noconvert) arg = default_conversion (arg); } else { error ("wrong type argument to bit-complement"); return error_mark_node; } break; case ABS_EXPR: if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE)) { error ("wrong type argument to abs"); return error_mark_node; } else if (!noconvert) arg = default_conversion (arg); break; case CONJ_EXPR: /* Conjugating a real value is a no-op, but allow it anyway. */ if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE || typecode == COMPLEX_TYPE)) { error ("wrong type argument to conjugation"); return error_mark_node; } else if (!noconvert) arg = default_conversion (arg); break; case TRUTH_NOT_EXPR: /* ??? Why do most validation here but that for non-lvalue arrays in c_objc_common_truthvalue_conversion? */ if (typecode != INTEGER_TYPE && typecode != REAL_TYPE && typecode != POINTER_TYPE && typecode != COMPLEX_TYPE /* These will convert to a pointer. */ && typecode != ARRAY_TYPE && typecode != FUNCTION_TYPE) { error ("wrong type argument to unary exclamation mark"); return error_mark_node; } arg = c_objc_common_truthvalue_conversion (arg); return invert_truthvalue (arg); case NOP_EXPR: break; case REALPART_EXPR: if (TREE_CODE (arg) == COMPLEX_CST) return TREE_REALPART (arg); else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) return fold (build1 (REALPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg)); else return arg; case IMAGPART_EXPR: if (TREE_CODE (arg) == COMPLEX_CST) return TREE_IMAGPART (arg); else if (TREE_CODE (TREE_TYPE (arg)) == COMPLEX_TYPE) return fold (build1 (IMAGPART_EXPR, TREE_TYPE (TREE_TYPE (arg)), arg)); else return convert (TREE_TYPE (arg), integer_zero_node); case PREINCREMENT_EXPR: case POSTINCREMENT_EXPR: case PREDECREMENT_EXPR: case POSTDECREMENT_EXPR: /* Increment or decrement the real part of the value, and don't change the imaginary part. */ if (typecode == COMPLEX_TYPE) { tree real, imag; if (pedantic) pedwarn ("ISO C does not support %<++%> and %<--%>" " on complex types"); arg = stabilize_reference (arg); real = build_unary_op (REALPART_EXPR, arg, 1); imag = build_unary_op (IMAGPART_EXPR, arg, 1); return build2 (COMPLEX_EXPR, TREE_TYPE (arg), build_unary_op (code, real, 1), imag); } /* Report invalid types. */ if (typecode != POINTER_TYPE && typecode != INTEGER_TYPE && typecode != REAL_TYPE) { if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) error ("wrong type argument to increment"); else error ("wrong type argument to decrement"); return error_mark_node; } { tree inc; tree result_type = TREE_TYPE (arg); arg = get_unwidened (arg, 0); argtype = TREE_TYPE (arg); /* Compute the increment. */ if (typecode == POINTER_TYPE) { /* If pointer target is an undefined struct, we just cannot know how to do the arithmetic. */ if (!COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (result_type))) { if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) error ("increment of pointer to unknown structure"); else error ("decrement of pointer to unknown structure"); } else if ((pedantic || warn_pointer_arith) && (TREE_CODE (TREE_TYPE (result_type)) == FUNCTION_TYPE || TREE_CODE (TREE_TYPE (result_type)) == VOID_TYPE)) { if (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) pedwarn ("wrong type argument to increment"); else pedwarn ("wrong type argument to decrement"); } inc = c_size_in_bytes (TREE_TYPE (result_type)); } else inc = integer_one_node; inc = convert (argtype, inc); /* Complain about anything else that is not a true lvalue. */ if (!lvalue_or_else (arg, ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) ? lv_increment : lv_decrement))) return error_mark_node; /* Report a read-only lvalue. */ if (TREE_READONLY (arg)) readonly_error (arg, ((code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR) ? lv_increment : lv_decrement)); if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE) val = boolean_increment (code, arg); else val = build2 (code, TREE_TYPE (arg), arg, inc); TREE_SIDE_EFFECTS (val) = 1; val = convert (result_type, val); if (TREE_CODE (val) != code) TREE_NO_WARNING (val) = 1; return val; } case ADDR_EXPR: /* Note that this operation never does default_conversion. */ /* Let &* cancel out to simplify resulting code. */ if (TREE_CODE (arg) == INDIRECT_REF) { /* Don't let this be an lvalue. */ if (lvalue_p (TREE_OPERAND (arg, 0))) return non_lvalue (TREE_OPERAND (arg, 0)); return TREE_OPERAND (arg, 0); } /* For &x[y], return x+y */ if (TREE_CODE (arg) == ARRAY_REF) { if (!c_mark_addressable (TREE_OPERAND (arg, 0))) return error_mark_node; return build_binary_op (PLUS_EXPR, TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1), 1); } /* Anything not already handled and not a true memory reference or a non-lvalue array is an error. */ else if (typecode != FUNCTION_TYPE && !flag && !lvalue_or_else (arg, lv_addressof)) return error_mark_node; /* Ordinary case; arg is a COMPONENT_REF or a decl. */ argtype = TREE_TYPE (arg); /* If the lvalue is const or volatile, merge that into the type to which the address will point. Note that you can't get a restricted pointer by taking the address of something, so we only have to deal with `const' and `volatile' here. */ if ((DECL_P (arg) || REFERENCE_CLASS_P (arg)) && (TREE_READONLY (arg) || TREE_THIS_VOLATILE (arg))) argtype = c_build_type_variant (argtype, TREE_READONLY (arg), TREE_THIS_VOLATILE (arg)); if (!c_mark_addressable (arg)) return error_mark_node; gcc_assert (TREE_CODE (arg) != COMPONENT_REF || !DECL_C_BIT_FIELD (TREE_OPERAND (arg, 1))); argtype = build_pointer_type (argtype); /* ??? Cope with user tricks that amount to offsetof. Delete this when we have proper support for integer constant expressions. */ val = get_base_address (arg); if (val && TREE_CODE (val) == INDIRECT_REF && integer_zerop (TREE_OPERAND (val, 0))) return fold_convert (argtype, fold_offsetof (arg)); val = build1 (ADDR_EXPR, argtype, arg); if (TREE_CODE (arg) == COMPOUND_LITERAL_EXPR) TREE_INVARIANT (val) = TREE_CONSTANT (val) = 1; return val; default: break; } if (argtype == 0) argtype = TREE_TYPE (arg); val = build1 (code, argtype, arg); return require_constant_value ? fold_initializer (val) : fold (val); } /* Return nonzero if REF is an lvalue valid for this language. Lvalues can be assigned, unless their type has TYPE_READONLY. Lvalues can have their address taken, unless they have C_DECL_REGISTER. */ static int lvalue_p (tree ref) { enum tree_code code = TREE_CODE (ref); switch (code) { case REALPART_EXPR: case IMAGPART_EXPR: case COMPONENT_REF: return lvalue_p (TREE_OPERAND (ref, 0)); case COMPOUND_LITERAL_EXPR: case STRING_CST: return 1; case INDIRECT_REF: case ARRAY_REF: case VAR_DECL: case PARM_DECL: case RESULT_DECL: case ERROR_MARK: return (TREE_CODE (TREE_TYPE (ref)) != FUNCTION_TYPE && TREE_CODE (TREE_TYPE (ref)) != METHOD_TYPE); case BIND_EXPR: return TREE_CODE (TREE_TYPE (ref)) == ARRAY_TYPE; default: return 0; } } /* Give an error for storing in something that is 'const'. */ static void readonly_error (tree arg, enum lvalue_use use) { gcc_assert (use == lv_assign || use == lv_increment || use == lv_decrement); /* Using this macro rather than (for example) arrays of messages ensures that all the format strings are checked at compile time. */ #define READONLY_MSG(A, I, D) (use == lv_assign \ ? (A) \ : (use == lv_increment ? (I) : (D))) if (TREE_CODE (arg) == COMPONENT_REF) { if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0)))) readonly_error (TREE_OPERAND (arg, 0), use); else error (READONLY_MSG (N_("assignment of read-only member %qD"), N_("increment of read-only member %qD"), N_("decrement of read-only member %qD")), TREE_OPERAND (arg, 1)); } else if (TREE_CODE (arg) == VAR_DECL) error (READONLY_MSG (N_("assignment of read-only variable %qD"), N_("increment of read-only variable %qD"), N_("decrement of read-only variable %qD")), arg); else error (READONLY_MSG (N_("assignment of read-only location"), N_("increment of read-only location"), N_("decrement of read-only location"))); } /* Return nonzero if REF is an lvalue valid for this language; otherwise, print an error message and return zero. USE says how the lvalue is being used and so selects the error message. */ static int lvalue_or_else (tree ref, enum lvalue_use use) { int win = lvalue_p (ref); if (!win) lvalue_error (use); return win; } /* Mark EXP saying that we need to be able to take the address of it; it should not be allocated in a register. Returns true if successful. */ bool c_mark_addressable (tree exp) { tree x = exp; while (1) switch (TREE_CODE (x)) { case COMPONENT_REF: if (DECL_C_BIT_FIELD (TREE_OPERAND (x, 1))) { error ("cannot take address of bit-field %qD", TREE_OPERAND (x, 1)); return false; } /* ... fall through ... */ case ADDR_EXPR: case ARRAY_REF: case REALPART_EXPR: case IMAGPART_EXPR: x = TREE_OPERAND (x, 0); break; case COMPOUND_LITERAL_EXPR: case CONSTRUCTOR: TREE_ADDRESSABLE (x) = 1; return true; case VAR_DECL: case CONST_DECL: case PARM_DECL: case RESULT_DECL: if (C_DECL_REGISTER (x) && DECL_NONLOCAL (x)) { if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) { error ("global register variable %qD used in nested function", x); return false; } pedwarn ("register variable %qD used in nested function", x); } else if (C_DECL_REGISTER (x)) { if (TREE_PUBLIC (x) || TREE_STATIC (x) || DECL_EXTERNAL (x)) error ("address of global register variable %qD requested", x); else error ("address of register variable %qD requested", x); return false; } /* drops in */ case FUNCTION_DECL: TREE_ADDRESSABLE (x) = 1; /* drops out */ default: return true; } } /* Build and return a conditional expression IFEXP ? OP1 : OP2. */ tree build_conditional_expr (tree ifexp, tree op1, tree op2) { tree type1; tree type2; enum tree_code code1; enum tree_code code2; tree result_type = NULL; tree orig_op1 = op1, orig_op2 = op2; /* Promote both alternatives. */ if (TREE_CODE (TREE_TYPE (op1)) != VOID_TYPE) op1 = default_conversion (op1); if (TREE_CODE (TREE_TYPE (op2)) != VOID_TYPE) op2 = default_conversion (op2); if (TREE_CODE (ifexp) == ERROR_MARK || TREE_CODE (TREE_TYPE (op1)) == ERROR_MARK || TREE_CODE (TREE_TYPE (op2)) == ERROR_MARK) return error_mark_node; type1 = TREE_TYPE (op1); code1 = TREE_CODE (type1); type2 = TREE_TYPE (op2); code2 = TREE_CODE (type2); /* C90 does not permit non-lvalue arrays in conditional expressions. In C99 they will be pointers by now. */ if (code1 == ARRAY_TYPE || code2 == ARRAY_TYPE) { error ("non-lvalue array in conditional expression"); return error_mark_node; } /* Quickly detect the usual case where op1 and op2 have the same type after promotion. */ if (TYPE_MAIN_VARIANT (type1) == TYPE_MAIN_VARIANT (type2)) { if (type1 == type2) result_type = type1; else result_type = TYPE_MAIN_VARIANT (type1); } else if ((code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE) && (code2 == INTEGER_TYPE || code2 == REAL_TYPE || code2 == COMPLEX_TYPE)) { result_type = c_common_type (type1, type2); /* If -Wsign-compare, warn here if type1 and type2 have different signedness. We'll promote the signed to unsigned and later code won't know it used to be different. Do this check on the original types, so that explicit casts will be considered, but default promotions won't. */ if (warn_sign_compare && !skip_evaluation) { int unsigned_op1 = TYPE_UNSIGNED (TREE_TYPE (orig_op1)); int unsigned_op2 = TYPE_UNSIGNED (TREE_TYPE (orig_op2)); if (unsigned_op1 ^ unsigned_op2) { /* Do not warn if the result type is signed, since the signed type will only be chosen if it can represent all the values of the unsigned type. */ if (!TYPE_UNSIGNED (result_type)) /* OK */; /* Do not warn if the signed quantity is an unsuffixed integer literal (or some static constant expression involving such literals) and it is non-negative. */ else if ((unsigned_op2 && tree_expr_nonnegative_p (op1)) || (unsigned_op1 && tree_expr_nonnegative_p (op2))) /* OK */; else warning ("signed and unsigned type in conditional expression"); } } } else if (code1 == VOID_TYPE || code2 == VOID_TYPE) { if (pedantic && (code1 != VOID_TYPE || code2 != VOID_TYPE)) pedwarn ("ISO C forbids conditional expr with only one void side"); result_type = void_type_node; } else if (code1 == POINTER_TYPE && code2 == POINTER_TYPE) { if (comp_target_types (type1, type2, 1)) result_type = common_pointer_type (type1, type2); else if (integer_zerop (op1) && TREE_TYPE (type1) == void_type_node && TREE_CODE (orig_op1) != NOP_EXPR) result_type = qualify_type (type2, type1); else if (integer_zerop (op2) && TREE_TYPE (type2) == void_type_node && TREE_CODE (orig_op2) != NOP_EXPR) result_type = qualify_type (type1, type2); else if (VOID_TYPE_P (TREE_TYPE (type1))) { if (pedantic && TREE_CODE (TREE_TYPE (type2)) == FUNCTION_TYPE) pedwarn ("ISO C forbids conditional expr between " "% and function pointer"); result_type = build_pointer_type (qualify_type (TREE_TYPE (type1), TREE_TYPE (type2))); } else if (VOID_TYPE_P (TREE_TYPE (type2))) { if (pedantic && TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE) pedwarn ("ISO C forbids conditional expr between " "% and function pointer"); result_type = build_pointer_type (qualify_type (TREE_TYPE (type2), TREE_TYPE (type1))); } else { pedwarn ("pointer type mismatch in conditional expression"); result_type = build_pointer_type (void_type_node); } } else if (code1 == POINTER_TYPE && code2 == INTEGER_TYPE) { if (!integer_zerop (op2)) pedwarn ("pointer/integer type mismatch in conditional expression"); else { op2 = null_pointer_node; } result_type = type1; } else if (code2 == POINTER_TYPE && code1 == INTEGER_TYPE) { if (!integer_zerop (op1)) pedwarn ("pointer/integer type mismatch in conditional expression"); else { op1 = null_pointer_node; } result_type = type2; } if (!result_type) { if (flag_cond_mismatch) result_type = void_type_node; else { error ("type mismatch in conditional expression"); return error_mark_node; } } /* Merge const and volatile flags of the incoming types. */ result_type = build_type_variant (result_type, TREE_READONLY (op1) || TREE_READONLY (op2), TREE_THIS_VOLATILE (op1) || TREE_THIS_VOLATILE (op2)); if (result_type != TREE_TYPE (op1)) op1 = convert_and_check (result_type, op1); if (result_type != TREE_TYPE (op2)) op2 = convert_and_check (result_type, op2); if (TREE_CODE (ifexp) == INTEGER_CST) return non_lvalue (integer_zerop (ifexp) ? op2 : op1); return fold (build3 (COND_EXPR, result_type, ifexp, op1, op2)); } /* Return a compound expression that performs two expressions and returns the value of the second of them. */ tree build_compound_expr (tree expr1, tree expr2) { /* Convert arrays and functions to pointers. */ expr2 = default_function_array_conversion (expr2); if (!TREE_SIDE_EFFECTS (expr1)) { /* The left-hand operand of a comma expression is like an expression statement: with -Wextra or -Wunused, we should warn if it doesn't have any side-effects, unless it was explicitly cast to (void). */ if (warn_unused_value && !(TREE_CODE (expr1) == CONVERT_EXPR && VOID_TYPE_P (TREE_TYPE (expr1)))) warning ("left-hand operand of comma expression has no effect"); } /* With -Wunused, we should also warn if the left-hand operand does have side-effects, but computes a value which is not used. For example, in `foo() + bar(), baz()' the result of the `+' operator is not used, so we should issue a warning. */ else if (warn_unused_value) warn_if_unused_value (expr1, input_location); return build2 (COMPOUND_EXPR, TREE_TYPE (expr2), expr1, expr2); } /* Build an expression representing a cast to type TYPE of expression EXPR. */ tree build_c_cast (tree type, tree expr) { tree value = expr; if (type == error_mark_node || expr == error_mark_node) return error_mark_node; /* The ObjC front-end uses TYPE_MAIN_VARIANT to tie together types differing only in qualifications. But when constructing cast expressions, the protocols do matter and must be kept around. */ if (objc_is_object_ptr (type) && objc_is_object_ptr (TREE_TYPE (expr))) return build1 (NOP_EXPR, type, expr); type = TYPE_MAIN_VARIANT (type); if (TREE_CODE (type) == ARRAY_TYPE) { error ("cast specifies array type"); return error_mark_node; } if (TREE_CODE (type) == FUNCTION_TYPE) { error ("cast specifies function type"); return error_mark_node; } if (type == TYPE_MAIN_VARIANT (TREE_TYPE (value))) { if (pedantic) { if (TREE_CODE (type) == RECORD_TYPE || TREE_CODE (type) == UNION_TYPE) pedwarn ("ISO C forbids casting nonscalar to the same type"); } } else if (TREE_CODE (type) == UNION_TYPE) { tree field; value = default_function_array_conversion (value); for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field)) if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (field)), TYPE_MAIN_VARIANT (TREE_TYPE (value)))) break; if (field) { tree t; if (pedantic) pedwarn ("ISO C forbids casts to union type"); t = digest_init (type, build_constructor (type, build_tree_list (field, value)), true, 0); TREE_CONSTANT (t) = TREE_CONSTANT (value); TREE_INVARIANT (t) = TREE_INVARIANT (value); return t; } error ("cast to union type from type not present in union"); return error_mark_node; } else { tree otype, ovalue; /* If casting to void, avoid the error that would come from default_conversion in the case of a non-lvalue array. */ if (type == void_type_node) return build1 (CONVERT_EXPR, type, value); /* Convert functions and arrays to pointers, but don't convert any other types. */ value = default_function_array_conversion (value); otype = TREE_TYPE (value); /* Optionally warn about potentially worrisome casts. */ if (warn_cast_qual && TREE_CODE (type) == POINTER_TYPE && TREE_CODE (otype) == POINTER_TYPE) { tree in_type = type; tree in_otype = otype; int added = 0; int discarded = 0; /* Check that the qualifiers on IN_TYPE are a superset of the qualifiers of IN_OTYPE. The outermost level of POINTER_TYPE nodes is uninteresting and we stop as soon as we hit a non-POINTER_TYPE node on either type. */ do { in_otype = TREE_TYPE (in_otype); in_type = TREE_TYPE (in_type); /* GNU C allows cv-qualified function types. 'const' means the function is very pure, 'volatile' means it can't return. We need to warn when such qualifiers are added, not when they're taken away. */ if (TREE_CODE (in_otype) == FUNCTION_TYPE && TREE_CODE (in_type) == FUNCTION_TYPE) added |= (TYPE_QUALS (in_type) & ~TYPE_QUALS (in_otype)); else discarded |= (TYPE_QUALS (in_otype) & ~TYPE_QUALS (in_type)); } while (TREE_CODE (in_type) == POINTER_TYPE && TREE_CODE (in_otype) == POINTER_TYPE); if (added) warning ("cast adds new qualifiers to function type"); if (discarded) /* There are qualifiers present in IN_OTYPE that are not present in IN_TYPE. */ warning ("cast discards qualifiers from pointer target type"); } /* Warn about possible alignment problems. */ if (STRICT_ALIGNMENT && warn_cast_align && TREE_CODE (type) == POINTER_TYPE && TREE_CODE (otype) == POINTER_TYPE && TREE_CODE (TREE_TYPE (otype)) != VOID_TYPE && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE /* Don't warn about opaque types, where the actual alignment restriction is unknown. */ && !((TREE_CODE (TREE_TYPE (otype)) == UNION_TYPE || TREE_CODE (TREE_TYPE (otype)) == RECORD_TYPE) && TYPE_MODE (TREE_TYPE (otype)) == VOIDmode) && TYPE_ALIGN (TREE_TYPE (type)) > TYPE_ALIGN (TREE_TYPE (otype))) warning ("cast increases required alignment of target type"); if (TREE_CODE (type) == INTEGER_TYPE && TREE_CODE (otype) == POINTER_TYPE && TYPE_PRECISION (type) != TYPE_PRECISION (otype) && !TREE_CONSTANT (value)) warning ("cast from pointer to integer of different size"); if (warn_bad_function_cast && TREE_CODE (value) == CALL_EXPR && TREE_CODE (type) != TREE_CODE (otype)) warning ("cast from function call of type %qT to non-matching " "type %qT", otype, type); if (TREE_CODE (type) == POINTER_TYPE && TREE_CODE (otype) == INTEGER_TYPE && TYPE_PRECISION (type) != TYPE_PRECISION (otype) /* Don't warn about converting any constant. */ && !TREE_CONSTANT (value)) warning ("cast to pointer from integer of different size"); if (TREE_CODE (type) == POINTER_TYPE && TREE_CODE (otype) == POINTER_TYPE && TREE_CODE (expr) == ADDR_EXPR && DECL_P (TREE_OPERAND (expr, 0)) && flag_strict_aliasing && warn_strict_aliasing && !VOID_TYPE_P (TREE_TYPE (type))) { /* Casting the address of a decl to non void pointer. Warn if the cast breaks type based aliasing. */ if (!COMPLETE_TYPE_P (TREE_TYPE (type))) warning ("type-punning to incomplete type might break strict-aliasing rules"); else { HOST_WIDE_INT set1 = get_alias_set (TREE_TYPE (TREE_OPERAND (expr, 0))); HOST_WIDE_INT set2 = get_alias_set (TREE_TYPE (type)); if (!alias_sets_conflict_p (set1, set2)) warning ("dereferencing type-punned pointer will break strict-aliasing rules"); else if (warn_strict_aliasing > 1 && !alias_sets_might_conflict_p (set1, set2)) warning ("dereferencing type-punned pointer might break strict-aliasing rules"); } } /* If pedantic, warn for conversions between function and object pointer types, except for converting a null pointer constant to function pointer type. */ if (pedantic && TREE_CODE (type) == POINTER_TYPE && TREE_CODE (otype) == POINTER_TYPE && TREE_CODE (TREE_TYPE (otype)) == FUNCTION_TYPE && TREE_CODE (TREE_TYPE (type)) != FUNCTION_TYPE) pedwarn ("ISO C forbids conversion of function pointer to object pointer type"); if (pedantic && TREE_CODE (type) == POINTER_TYPE && TREE_CODE (otype) == POINTER_TYPE && TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE && TREE_CODE (TREE_TYPE (otype)) != FUNCTION_TYPE && !(integer_zerop (value) && TREE_TYPE (otype) == void_type_node && TREE_CODE (expr) != NOP_EXPR)) pedwarn ("ISO C forbids conversion of object pointer to function pointer type"); ovalue = value; value = convert (type, value); /* Ignore any integer overflow caused by the cast. */ if (TREE_CODE (value) == INTEGER_CST) { if (EXPR_P (ovalue)) /* If OVALUE had overflow set, then so will VALUE, so it is safe to overwrite. */ TREE_OVERFLOW (value) = TREE_OVERFLOW (ovalue); else TREE_OVERFLOW (value) = 0; if (CONSTANT_CLASS_P (ovalue)) /* Similarly, constant_overflow cannot have become cleared. */ TREE_CONSTANT_OVERFLOW (value) = TREE_CONSTANT_OVERFLOW (ovalue); } } /* Don't let a cast be an lvalue. */ if (value == expr) value = non_lvalue (value); return value; } /* Interpret a cast of expression EXPR to type TYPE. */ tree c_cast_expr (struct c_type_name *type_name, tree expr) { tree type; int saved_wsp = warn_strict_prototypes; /* This avoids warnings about unprototyped casts on integers. E.g. "#define SIG_DFL (void(*)())0". */ if (TREE_CODE (expr) == INTEGER_CST) warn_strict_prototypes = 0; type = groktypename (type_name); warn_strict_prototypes = saved_wsp; return build_c_cast (type, expr); } /* Build an assignment expression of lvalue LHS from value RHS. MODIFYCODE is the code for a binary operator that we use to combine the old value of LHS with RHS to get the new value. Or else MODIFYCODE is NOP_EXPR meaning do a simple assignment. */ tree build_modify_expr (tree lhs, enum tree_code modifycode, tree rhs) { tree result; tree newrhs; tree lhstype = TREE_TYPE (lhs); tree olhstype = lhstype; /* Types that aren't fully specified cannot be used in assignments. */ lhs = require_complete_type (lhs); /* Avoid duplicate error messages from operands that had errors. */ if (TREE_CODE (lhs) == ERROR_MARK || TREE_CODE (rhs) == ERROR_MARK) return error_mark_node; STRIP_TYPE_NOPS (rhs); newrhs = rhs; /* If a binary op has been requested, combine the old LHS value with the RHS producing the value we should actually store into the LHS. */ if (modifycode != NOP_EXPR) { lhs = stabilize_reference (lhs); newrhs = build_binary_op (modifycode, lhs, rhs, 1); } if (!lvalue_or_else (lhs, lv_assign)) return error_mark_node; /* Give an error for storing in something that is 'const'. */ if (TREE_READONLY (lhs) || TYPE_READONLY (lhstype) || ((TREE_CODE (lhstype) == RECORD_TYPE || TREE_CODE (lhstype) == UNION_TYPE) && C_TYPE_FIELDS_READONLY (lhstype))) readonly_error (lhs, lv_assign); /* If storing into a structure or union member, it has probably been given type `int'. Compute the type that would go with the actual amount of storage the member occupies. */ if (TREE_CODE (lhs) == COMPONENT_REF && (TREE_CODE (lhstype) == INTEGER_TYPE || TREE_CODE (lhstype) == BOOLEAN_TYPE || TREE_CODE (lhstype) == REAL_TYPE || TREE_CODE (lhstype) == ENUMERAL_TYPE)) lhstype = TREE_TYPE (get_unwidened (lhs, 0)); /* If storing in a field that is in actuality a short or narrower than one, we must store in the field in its actual type. */ if (lhstype != TREE_TYPE (lhs)) { lhs = copy_node (lhs); TREE_TYPE (lhs) = lhstype; } /* Convert new value to destination type. */ newrhs = convert_for_assignment (lhstype, newrhs, ic_assign, NULL_TREE, NULL_TREE, 0); if (TREE_CODE (newrhs) == ERROR_MARK) return error_mark_node; /* Scan operands. */ result = build2 (MODIFY_EXPR, lhstype, lhs, newrhs); TREE_SIDE_EFFECTS (result) = 1; /* If we got the LHS in a different type for storing in, convert the result back to the nominal type of LHS so that the value we return always has the same type as the LHS argument. */ if (olhstype == TREE_TYPE (result)) return result; return convert_for_assignment (olhstype, result, ic_assign, NULL_TREE, NULL_TREE, 0); } /* Convert value RHS to type TYPE as preparation for an assignment to an lvalue of type TYPE. The real work of conversion is done by `convert'. The purpose of this function is to generate error messages for assignments that are not allowed in C. ERRTYPE says whether it is argument passing, assignment, initialization or return. FUNCTION is a tree for the function being called. PARMNUM is the number of the argument, for printing in error messages. */ static tree convert_for_assignment (tree type, tree rhs, enum impl_conv errtype, tree fundecl, tree function, int parmnum) { enum tree_code codel = TREE_CODE (type); tree rhstype; enum tree_code coder; tree rname = NULL_TREE; if (errtype == ic_argpass || errtype == ic_argpass_nonproto) { tree selector; /* Change pointer to function to the function itself for diagnostics. */ if (TREE_CODE (function) == ADDR_EXPR && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL) function = TREE_OPERAND (function, 0); /* Handle an ObjC selector specially for diagnostics. */ selector = objc_message_selector (); rname = function; if (selector && parmnum > 2) { rname = selector; parmnum -= 2; } } /* This macro is used to emit diagnostics to ensure that all format strings are complete sentences, visible to gettext and checked at compile time. */ #define WARN_FOR_ASSIGNMENT(AR, AS, IN, RE) \ do { \ switch (errtype) \ { \ case ic_argpass: \ pedwarn (AR, parmnum, rname); \ break; \ case ic_argpass_nonproto: \ warning (AR, parmnum, rname); \ break; \ case ic_assign: \ pedwarn (AS); \ break; \ case ic_init: \ pedwarn (IN); \ break; \ case ic_return: \ pedwarn (RE); \ break; \ default: \ gcc_unreachable (); \ } \ } while (0) STRIP_TYPE_NOPS (rhs); if (TREE_CODE (TREE_TYPE (rhs)) == ARRAY_TYPE || TREE_CODE (TREE_TYPE (rhs)) == FUNCTION_TYPE) rhs = default_conversion (rhs); else if (optimize && TREE_CODE (rhs) == VAR_DECL) rhs = decl_constant_value_for_broken_optimization (rhs); rhstype = TREE_TYPE (rhs); coder = TREE_CODE (rhstype); if (coder == ERROR_MARK) return error_mark_node; if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (rhstype)) { overflow_warning (rhs); /* Check for Objective-C protocols. This will automatically issue a warning if there are protocol violations. No need to use the return value. */ if (c_dialect_objc ()) objc_comptypes (type, rhstype, 0); return rhs; } if (coder == VOID_TYPE) { /* Except for passing an argument to an unprototyped function, this is a constraint violation. When passing an argument to an unprototyped function, it is compile-time undefined; making it a constraint in that case was rejected in DR#252. */ error ("void value not ignored as it ought to be"); return error_mark_node; } /* A type converts to a reference to it. This code doesn't fully support references, it's just for the special case of va_start and va_copy. */ if (codel == REFERENCE_TYPE && comptypes (TREE_TYPE (type), TREE_TYPE (rhs)) == 1) { if (!lvalue_p (rhs)) { error ("cannot pass rvalue to reference parameter"); return error_mark_node; } if (!c_mark_addressable (rhs)) return error_mark_node; rhs = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (rhs)), rhs); /* We already know that these two types are compatible, but they may not be exactly identical. In fact, `TREE_TYPE (type)' is likely to be __builtin_va_list and `TREE_TYPE (rhs)' is likely to be va_list, a typedef to __builtin_va_list, which is different enough that it will cause problems later. */ if (TREE_TYPE (TREE_TYPE (rhs)) != TREE_TYPE (type)) rhs = build1 (NOP_EXPR, build_pointer_type (TREE_TYPE (type)), rhs); rhs = build1 (NOP_EXPR, type, rhs); return rhs; } /* Some types can interconvert without explicit casts. */ else if (codel == VECTOR_TYPE && coder == VECTOR_TYPE && vector_types_convertible_p (type, TREE_TYPE (rhs))) return convert (type, rhs); /* Arithmetic types all interconvert, and enum is treated like int. */ else if ((codel == INTEGER_TYPE || codel == REAL_TYPE || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE || codel == BOOLEAN_TYPE) && (coder == INTEGER_TYPE || coder == REAL_TYPE || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE || coder == BOOLEAN_TYPE)) return convert_and_check (type, rhs); /* Conversion to a transparent union from its member types. This applies only to function arguments. */ else if (codel == UNION_TYPE && TYPE_TRANSPARENT_UNION (type) && (errtype == ic_argpass || errtype == ic_argpass_nonproto)) { tree memb_types; tree marginal_memb_type = 0; for (memb_types = TYPE_FIELDS (type); memb_types; memb_types = TREE_CHAIN (memb_types)) { tree memb_type = TREE_TYPE (memb_types); if (comptypes (TYPE_MAIN_VARIANT (memb_type), TYPE_MAIN_VARIANT (rhstype))) break; if (TREE_CODE (memb_type) != POINTER_TYPE) continue; if (coder == POINTER_TYPE) { tree ttl = TREE_TYPE (memb_type); tree ttr = TREE_TYPE (rhstype); /* Any non-function converts to a [const][volatile] void * and vice versa; otherwise, targets must be the same. Meanwhile, the lhs target must have all the qualifiers of the rhs. */ if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) || comp_target_types (memb_type, rhstype, 0)) { /* If this type won't generate any warnings, use it. */ if (TYPE_QUALS (ttl) == TYPE_QUALS (ttr) || ((TREE_CODE (ttr) == FUNCTION_TYPE && TREE_CODE (ttl) == FUNCTION_TYPE) ? ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) == TYPE_QUALS (ttr)) : ((TYPE_QUALS (ttl) | TYPE_QUALS (ttr)) == TYPE_QUALS (ttl)))) break; /* Keep looking for a better type, but remember this one. */ if (!marginal_memb_type) marginal_memb_type = memb_type; } } /* Can convert integer zero to any pointer type. */ if (integer_zerop (rhs) || (TREE_CODE (rhs) == NOP_EXPR && integer_zerop (TREE_OPERAND (rhs, 0)))) { rhs = null_pointer_node; break; } } if (memb_types || marginal_memb_type) { if (!memb_types) { /* We have only a marginally acceptable member type; it needs a warning. */ tree ttl = TREE_TYPE (marginal_memb_type); tree ttr = TREE_TYPE (rhstype); /* Const and volatile mean something different for function types, so the usual warnings are not appropriate. */ if (TREE_CODE (ttr) == FUNCTION_TYPE && TREE_CODE (ttl) == FUNCTION_TYPE) { /* Because const and volatile on functions are restrictions that say the function will not do certain things, it is okay to use a const or volatile function where an ordinary one is wanted, but not vice-versa. */ if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) WARN_FOR_ASSIGNMENT (N_("passing argument %d of %qE " "makes qualified function " "pointer from unqualified"), N_("assignment makes qualified " "function pointer from " "unqualified"), N_("initialization makes qualified " "function pointer from " "unqualified"), N_("return makes qualified function " "pointer from unqualified")); } else if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) WARN_FOR_ASSIGNMENT (N_("passing argument %d of %qE discards " "qualifiers from pointer target type"), N_("assignment discards qualifiers " "from pointer target type"), N_("initialization discards qualifiers " "from pointer target type"), N_("return discards qualifiers from " "pointer target type")); } if (pedantic && !DECL_IN_SYSTEM_HEADER (fundecl)) pedwarn ("ISO C prohibits argument conversion to union type"); return build1 (NOP_EXPR, type, rhs); } } /* Conversions among pointers */ else if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE) && (coder == codel)) { tree ttl = TREE_TYPE (type); tree ttr = TREE_TYPE (rhstype); tree mvl = ttl; tree mvr = ttr; bool is_opaque_pointer; int target_cmp = 0; /* Cache comp_target_types () result. */ if (TREE_CODE (mvl) != ARRAY_TYPE) mvl = TYPE_MAIN_VARIANT (mvl); if (TREE_CODE (mvr) != ARRAY_TYPE) mvr = TYPE_MAIN_VARIANT (mvr); /* Opaque pointers are treated like void pointers. */ is_opaque_pointer = (targetm.vector_opaque_p (type) || targetm.vector_opaque_p (rhstype)) && TREE_CODE (ttl) == VECTOR_TYPE && TREE_CODE (ttr) == VECTOR_TYPE; /* Any non-function converts to a [const][volatile] void * and vice versa; otherwise, targets must be the same. Meanwhile, the lhs target must have all the qualifiers of the rhs. */ if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) || (target_cmp = comp_target_types (type, rhstype, 0)) || is_opaque_pointer || (c_common_unsigned_type (mvl) == c_common_unsigned_type (mvr))) { if (pedantic && ((VOID_TYPE_P (ttl) && TREE_CODE (ttr) == FUNCTION_TYPE) || (VOID_TYPE_P (ttr) /* Check TREE_CODE to catch cases like (void *) (char *) 0 which are not ANSI null ptr constants. */ && (!integer_zerop (rhs) || TREE_CODE (rhs) == NOP_EXPR) && TREE_CODE (ttl) == FUNCTION_TYPE))) WARN_FOR_ASSIGNMENT (N_("ISO C forbids passing argument %d of " "%qE between function pointer " "and %"), N_("ISO C forbids assignment between " "function pointer and %"), N_("ISO C forbids initialization between " "function pointer and %"), N_("ISO C forbids return between function " "pointer and %")); /* Const and volatile mean something different for function types, so the usual warnings are not appropriate. */ else if (TREE_CODE (ttr) != FUNCTION_TYPE && TREE_CODE (ttl) != FUNCTION_TYPE) { if (TYPE_QUALS (ttr) & ~TYPE_QUALS (ttl)) WARN_FOR_ASSIGNMENT (N_("passing argument %d of %qE discards " "qualifiers from pointer target type"), N_("assignment discards qualifiers " "from pointer target type"), N_("initialization discards qualifiers " "from pointer target type"), N_("return discards qualifiers from " "pointer target type")); /* If this is not a case of ignoring a mismatch in signedness, no warning. */ else if (VOID_TYPE_P (ttl) || VOID_TYPE_P (ttr) || target_cmp) ; /* If there is a mismatch, do warn. */ else if (warn_pointer_sign) WARN_FOR_ASSIGNMENT (N_("pointer targets in passing argument " "%d of %qE differ in signedness"), N_("pointer targets in assignment " "differ in signedness"), N_("pointer targets in initialization " "differ in signedness"), N_("pointer targets in return differ " "in signedness")); } else if (TREE_CODE (ttl) == FUNCTION_TYPE && TREE_CODE (ttr) == FUNCTION_TYPE) { /* Because const and volatile on functions are restrictions that say the function will not do certain things, it is okay to use a const or volatile function where an ordinary one is wanted, but not vice-versa. */ if (TYPE_QUALS (ttl) & ~TYPE_QUALS (ttr)) WARN_FOR_ASSIGNMENT (N_("passing argument %d of %qE makes " "qualified function pointer " "from unqualified"), N_("assignment makes qualified function " "pointer from unqualified"), N_("initialization makes qualified " "function pointer from unqualified"), N_("return makes qualified function " "pointer from unqualified")); } } else WARN_FOR_ASSIGNMENT (N_("passing argument %d of %qE from " "incompatible pointer type"), N_("assignment from incompatible pointer type"), N_("initialization from incompatible " "pointer type"), N_("return from incompatible pointer type")); return convert (type, rhs); } else if (codel == POINTER_TYPE && coder == ARRAY_TYPE) { /* ??? This should not be an error when inlining calls to unprototyped functions. */ error ("invalid use of non-lvalue array"); return error_mark_node; } else if (codel == POINTER_TYPE && coder == INTEGER_TYPE) { /* An explicit constant 0 can convert to a pointer, or one that results from arithmetic, even including a cast to integer type. */ if (!(TREE_CODE (rhs) == INTEGER_CST && integer_zerop (rhs)) && !(TREE_CODE (rhs) == NOP_EXPR && TREE_CODE (TREE_TYPE (rhs)) == INTEGER_TYPE && TREE_CODE (TREE_OPERAND (rhs, 0)) == INTEGER_CST && integer_zerop (TREE_OPERAND (rhs, 0)))) WARN_FOR_ASSIGNMENT (N_("passing argument %d of %qE makes " "pointer from integer without a cast"), N_("assignment makes pointer from integer " "without a cast"), N_("initialization makes pointer from " "integer without a cast"), N_("return makes pointer from integer " "without a cast")); return convert (type, rhs); } else if (codel == INTEGER_TYPE && coder == POINTER_TYPE) { WARN_FOR_ASSIGNMENT (N_("passing argument %d of %qE makes integer " "from pointer without a cast"), N_("assignment makes integer from pointer " "without a cast"), N_("initialization makes integer from pointer " "without a cast"), N_("return makes integer from pointer " "without a cast")); return convert (type, rhs); } else if (codel == BOOLEAN_TYPE && coder == POINTER_TYPE) return convert (type, rhs); switch (errtype) { case ic_argpass: case ic_argpass_nonproto: /* ??? This should not be an error when inlining calls to unprototyped functions. */ error ("incompatible type for argument %d of %qE", parmnum, rname); break; case ic_assign: error ("incompatible types in assignment"); break; case ic_init: error ("incompatible types in initialization"); break; case ic_return: error ("incompatible types in return"); break; default: gcc_unreachable (); } return error_mark_node; } /* Convert VALUE for assignment into inlined parameter PARM. ARGNUM is used for error and waring reporting and indicates which argument is being processed. */ tree c_convert_parm_for_inlining (tree parm, tree value, tree fn, int argnum) { tree ret, type; /* If FN was prototyped, the value has been converted already in convert_arguments. */ if (!value || TYPE_ARG_TYPES (TREE_TYPE (fn))) return value; type = TREE_TYPE (parm); ret = convert_for_assignment (type, value, ic_argpass_nonproto, fn, fn, argnum); if (targetm.calls.promote_prototypes (TREE_TYPE (fn)) && INTEGRAL_TYPE_P (type) && (TYPE_PRECISION (type) < TYPE_PRECISION (integer_type_node))) ret = default_conversion (ret); return ret; } /* If VALUE is a compound expr all of whose expressions are constant, then return its value. Otherwise, return error_mark_node. This is for handling COMPOUND_EXPRs as initializer elements which is allowed with a warning when -pedantic is specified. */ static tree valid_compound_expr_initializer (tree value, tree endtype) { if (TREE_CODE (value) == COMPOUND_EXPR) { if (valid_compound_expr_initializer (TREE_OPERAND (value, 0), endtype) == error_mark_node) return error_mark_node; return valid_compound_expr_initializer (TREE_OPERAND (value, 1), endtype); } else if (!initializer_constant_valid_p (value, endtype)) return error_mark_node; else return value; } /* Perform appropriate conversions on the initial value of a variable, store it in the declaration DECL, and print any error messages that are appropriate. If the init is invalid, store an ERROR_MARK. */ void store_init_value (tree decl, tree init) { tree value, type; /* If variable's type was invalidly declared, just ignore it. */ type = TREE_TYPE (decl); if (TREE_CODE (type) == ERROR_MARK) return; /* Digest the specified initializer into an expression. */ value = digest_init (type, init, true, TREE_STATIC (decl)); /* Store the expression if valid; else report error. */ if (warn_traditional && !in_system_header && AGGREGATE_TYPE_P (TREE_TYPE (decl)) && !TREE_STATIC (decl)) warning ("traditional C rejects automatic aggregate initialization"); DECL_INITIAL (decl) = value; /* ANSI wants warnings about out-of-range constant initializers. */ STRIP_TYPE_NOPS (value); constant_expression_warning (value); /* Check if we need to set array size from compound literal size. */ if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == 0 && value != error_mark_node) { tree inside_init = init; STRIP_TYPE_NOPS (inside_init); inside_init = fold (inside_init); if (TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) { tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); if (TYPE_DOMAIN (TREE_TYPE (decl))) { /* For int foo[] = (int [3]){1}; we need to set array size now since later on array initializer will be just the brace enclosed list of the compound literal. */ TYPE_DOMAIN (type) = TYPE_DOMAIN (TREE_TYPE (decl)); layout_type (type); layout_decl (decl, 0); } } } } /* Methods for storing and printing names for error messages. */ /* Implement a spelling stack that allows components of a name to be pushed and popped. Each element on the stack is this structure. */ struct spelling { int kind; union { int i; const char *s; } u; }; #define SPELLING_STRING 1 #define SPELLING_MEMBER 2 #define SPELLING_BOUNDS 3 static struct spelling *spelling; /* Next stack element (unused). */ static struct spelling *spelling_base; /* Spelling stack base. */ static int spelling_size; /* Size of the spelling stack. */ /* Macros to save and restore the spelling stack around push_... functions. Alternative to SAVE_SPELLING_STACK. */ #define SPELLING_DEPTH() (spelling - spelling_base) #define RESTORE_SPELLING_DEPTH(DEPTH) (spelling = spelling_base + (DEPTH)) /* Push an element on the spelling stack with type KIND and assign VALUE to MEMBER. */ #define PUSH_SPELLING(KIND, VALUE, MEMBER) \ { \ int depth = SPELLING_DEPTH (); \ \ if (depth >= spelling_size) \ { \ spelling_size += 10; \ spelling_base = XRESIZEVEC (struct spelling, spelling_base, \ spelling_size); \ RESTORE_SPELLING_DEPTH (depth); \ } \ \ spelling->kind = (KIND); \ spelling->MEMBER = (VALUE); \ spelling++; \ } /* Push STRING on the stack. Printed literally. */ static void push_string (const char *string) { PUSH_SPELLING (SPELLING_STRING, string, u.s); } /* Push a member name on the stack. Printed as '.' STRING. */ static void push_member_name (tree decl) { const char *const string = DECL_NAME (decl) ? IDENTIFIER_POINTER (DECL_NAME (decl)) : ""; PUSH_SPELLING (SPELLING_MEMBER, string, u.s); } /* Push an array bounds on the stack. Printed as [BOUNDS]. */ static void push_array_bounds (int bounds) { PUSH_SPELLING (SPELLING_BOUNDS, bounds, u.i); } /* Compute the maximum size in bytes of the printed spelling. */ static int spelling_length (void) { int size = 0; struct spelling *p; for (p = spelling_base; p < spelling; p++) { if (p->kind == SPELLING_BOUNDS) size += 25; else size += strlen (p->u.s) + 1; } return size; } /* Print the spelling to BUFFER and return it. */ static char * print_spelling (char *buffer) { char *d = buffer; struct spelling *p; for (p = spelling_base; p < spelling; p++) if (p->kind == SPELLING_BOUNDS) { sprintf (d, "[%d]", p->u.i); d += strlen (d); } else { const char *s; if (p->kind == SPELLING_MEMBER) *d++ = '.'; for (s = p->u.s; (*d = *s++); d++) ; } *d++ = '\0'; return buffer; } /* Issue an error message for a bad initializer component. MSGID identifies the message. The component name is taken from the spelling stack. */ void error_init (const char *msgid) { char *ofwhat; error ("%s", _(msgid)); ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); if (*ofwhat) error ("(near initialization for %qs)", ofwhat); } /* Issue a pedantic warning for a bad initializer component. MSGID identifies the message. The component name is taken from the spelling stack. */ void pedwarn_init (const char *msgid) { char *ofwhat; pedwarn ("%s", _(msgid)); ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); if (*ofwhat) pedwarn ("(near initialization for %qs)", ofwhat); } /* Issue a warning for a bad initializer component. MSGID identifies the message. The component name is taken from the spelling stack. */ static void warning_init (const char *msgid) { char *ofwhat; warning ("%s", _(msgid)); ofwhat = print_spelling ((char *) alloca (spelling_length () + 1)); if (*ofwhat) warning ("(near initialization for %qs)", ofwhat); } /* If TYPE is an array type and EXPR is a parenthesized string constant, warn if pedantic that EXPR is being used to initialize an object of type TYPE. */ void maybe_warn_string_init (tree type, struct c_expr expr) { if (pedantic && TREE_CODE (type) == ARRAY_TYPE && TREE_CODE (expr.value) == STRING_CST && expr.original_code != STRING_CST) pedwarn_init ("array initialized from parenthesized string constant"); } /* Digest the parser output INIT as an initializer for type TYPE. Return a C expression of type TYPE to represent the initial value. If INIT is a string constant, STRICT_STRING is true if it is unparenthesized or we should not warn here for it being parenthesized. For other types of INIT, STRICT_STRING is not used. REQUIRE_CONSTANT requests an error if non-constant initializers or elements are seen. */ static tree digest_init (tree type, tree init, bool strict_string, int require_constant) { enum tree_code code = TREE_CODE (type); tree inside_init = init; if (type == error_mark_node || init == error_mark_node || TREE_TYPE (init) == error_mark_node) return error_mark_node; STRIP_TYPE_NOPS (inside_init); inside_init = fold (inside_init); /* Initialization of an array of chars from a string constant optionally enclosed in braces. */ if (code == ARRAY_TYPE && inside_init && TREE_CODE (inside_init) == STRING_CST) { tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type)); /* Note that an array could be both an array of character type and an array of wchar_t if wchar_t is signed char or unsigned char. */ bool char_array = (typ1 == char_type_node || typ1 == signed_char_type_node || typ1 == unsigned_char_type_node); bool wchar_array = !!comptypes (typ1, wchar_type_node); if (char_array || wchar_array) { struct c_expr expr; bool char_string; expr.value = inside_init; expr.original_code = (strict_string ? STRING_CST : ERROR_MARK); maybe_warn_string_init (type, expr); char_string = (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (inside_init))) == char_type_node); if (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), TYPE_MAIN_VARIANT (type))) return inside_init; if (!wchar_array && !char_string) { error_init ("char-array initialized from wide string"); return error_mark_node; } if (char_string && !char_array) { error_init ("wchar_t-array initialized from non-wide string"); return error_mark_node; } TREE_TYPE (inside_init) = type; if (TYPE_DOMAIN (type) != 0 && TYPE_SIZE (type) != 0 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST /* Subtract 1 (or sizeof (wchar_t)) because it's ok to ignore the terminating null char that is counted in the length of the constant. */ && 0 > compare_tree_int (TYPE_SIZE_UNIT (type), TREE_STRING_LENGTH (inside_init) - ((TYPE_PRECISION (typ1) != TYPE_PRECISION (char_type_node)) ? (TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT) : 1))) pedwarn_init ("initializer-string for array of chars is too long"); return inside_init; } else if (INTEGRAL_TYPE_P (typ1)) { error_init ("array of inappropriate type initialized " "from string constant"); return error_mark_node; } } /* Build a VECTOR_CST from a *constant* vector constructor. If the vector constructor is not constant (e.g. {1,2,3,foo()}) then punt below and handle as a constructor. */ if (code == VECTOR_TYPE && TREE_CODE (TREE_TYPE (inside_init)) == VECTOR_TYPE && vector_types_convertible_p (TREE_TYPE (inside_init), type) && TREE_CONSTANT (inside_init)) { if (TREE_CODE (inside_init) == VECTOR_CST && comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), TYPE_MAIN_VARIANT (type))) return inside_init; if (TREE_CODE (inside_init) == CONSTRUCTOR) { tree link; /* Iterate through elements and check if all constructor elements are *_CSTs. */ for (link = CONSTRUCTOR_ELTS (inside_init); link; link = TREE_CHAIN (link)) if (! CONSTANT_CLASS_P (TREE_VALUE (link))) break; if (link == NULL) return build_vector (type, CONSTRUCTOR_ELTS (inside_init)); } } /* Any type can be initialized from an expression of the same type, optionally with braces. */ if (inside_init && TREE_TYPE (inside_init) != 0 && (comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (inside_init)), TYPE_MAIN_VARIANT (type)) || (code == ARRAY_TYPE && comptypes (TREE_TYPE (inside_init), type)) || (code == VECTOR_TYPE && comptypes (TREE_TYPE (inside_init), type)) || (code == POINTER_TYPE && TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE && comptypes (TREE_TYPE (TREE_TYPE (inside_init)), TREE_TYPE (type))) || (code == POINTER_TYPE && TREE_CODE (TREE_TYPE (inside_init)) == FUNCTION_TYPE && comptypes (TREE_TYPE (inside_init), TREE_TYPE (type))))) { if (code == POINTER_TYPE) { inside_init = default_function_array_conversion (inside_init); if (TREE_CODE (TREE_TYPE (inside_init)) == ARRAY_TYPE) { error_init ("invalid use of non-lvalue array"); return error_mark_node; } } if (code == VECTOR_TYPE) /* Although the types are compatible, we may require a conversion. */ inside_init = convert (type, inside_init); if (require_constant && !flag_isoc99 && TREE_CODE (inside_init) == COMPOUND_LITERAL_EXPR) { /* As an extension, allow initializing objects with static storage duration with compound literals (which are then treated just as the brace enclosed list they contain). */ tree decl = COMPOUND_LITERAL_EXPR_DECL (inside_init); inside_init = DECL_INITIAL (decl); } if (code == ARRAY_TYPE && TREE_CODE (inside_init) != STRING_CST && TREE_CODE (inside_init) != CONSTRUCTOR) { error_init ("array initialized from non-constant array expression"); return error_mark_node; } if (optimize && TREE_CODE (inside_init) == VAR_DECL) inside_init = decl_constant_value_for_broken_optimization (inside_init); /* Compound expressions can only occur here if -pedantic or -pedantic-errors is specified. In the later case, we always want an error. In the former case, we simply want a warning. */ if (require_constant && pedantic && TREE_CODE (inside_init) == COMPOUND_EXPR) { inside_init = valid_compound_expr_initializer (inside_init, TREE_TYPE (inside_init)); if (inside_init == error_mark_node) error_init ("initializer element is not constant"); else pedwarn_init ("initializer element is not constant"); if (flag_pedantic_errors) inside_init = error_mark_node; } else if (require_constant && !initializer_constant_valid_p (inside_init, TREE_TYPE (inside_init))) { error_init ("initializer element is not constant"); inside_init = error_mark_node; } return inside_init; } /* Handle scalar types, including conversions. */ if (code == INTEGER_TYPE || code == REAL_TYPE || code == POINTER_TYPE || code == ENUMERAL_TYPE || code == BOOLEAN_TYPE || code == COMPLEX_TYPE || code == VECTOR_TYPE) { /* Note that convert_for_assignment calls default_conversion for arrays and functions. We must not call it in the case where inside_init is a null pointer constant. */ inside_init = convert_for_assignment (type, init, ic_init, NULL_TREE, NULL_TREE, 0); /* Check to see if we have already given an error message. */ if (inside_init == error_mark_node) ; else if (require_constant && !TREE_CONSTANT (inside_init)) { error_init ("initializer element is not constant"); inside_init = error_mark_node; } else if (require_constant && !initializer_constant_valid_p (inside_init, TREE_TYPE (inside_init))) { error_init ("initializer element is not computable at load time"); inside_init = error_mark_node; } return inside_init; } /* Come here only for records and arrays. */ if (COMPLETE_TYPE_P (type) && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST) { error_init ("variable-sized object may not be initialized"); return error_mark_node; } error_init ("invalid initializer"); return error_mark_node; } /* Handle initializers that use braces. */ /* Type of object we are accumulating a constructor for. This type is always a RECORD_TYPE, UNION_TYPE or ARRAY_TYPE. */ static tree constructor_type; /* For a RECORD_TYPE or UNION_TYPE, this is the chain of fields left to fill. */ static tree constructor_fields; /* For an ARRAY_TYPE, this is the specified index at which to store the next element we get. */ static tree constructor_index; /* For an ARRAY_TYPE, this is the maximum index. */ static tree constructor_max_index; /* For a RECORD_TYPE, this is the first field not yet written out. */ static tree constructor_unfilled_fields; /* For an ARRAY_TYPE, this is the index of the first element not yet written out. */ static tree constructor_unfilled_index; /* In a RECORD_TYPE, the byte index of the next consecutive field. This is so we can generate gaps between fields, when appropriate. */ static tree constructor_bit_index; /* If we are saving up the elements rather than allocating them, this is the list of elements so far (in reverse order, most recent first). */ static tree constructor_elements; /* 1 if constructor should be incrementally stored into a constructor chain, 0 if all the elements should be kept in AVL tree. */ static int constructor_incremental; /* 1 if so far this constructor's elements are all compile-time constants. */ static int constructor_constant; /* 1 if so far this constructor's elements are all valid address constants. */ static int constructor_simple; /* 1 if this constructor is erroneous so far. */ static int constructor_erroneous; /* Structure for managing pending initializer elements, organized as an AVL tree. */ struct init_node { struct init_node *left, *right; struct init_node *parent; int balance; tree purpose; tree value; }; /* Tree of pending elements at this constructor level. These are elements encountered out of order which belong at places we haven't reached yet in actually writing the output. Will never hold tree nodes across GC runs. */ static struct init_node *constructor_pending_elts; /* The SPELLING_DEPTH of this constructor. */ static int constructor_depth; /* DECL node for which an initializer is being read. 0 means we are reading a constructor expression such as (struct foo) {...}. */ static tree constructor_decl; /* Nonzero if this is an initializer for a top-level decl. */ static int constructor_top_level; /* Nonzero if there were any member designators in this initializer. */ static int constructor_designated; /* Nesting depth of designator list. */ static int designator_depth; /* Nonzero if there were diagnosed errors in this designator list. */ static int designator_errorneous; /* This stack has a level for each implicit or explicit level of structuring in the initializer, including the outermost one. It saves the values of most of the variables above. */ struct constructor_range_stack; struct constructor_stack { struct constructor_stack *next; tree type; tree fields; tree index; tree max_index; tree unfilled_index; tree unfilled_fields; tree bit_index; tree elements; struct init_node *pending_elts; int offset; int depth; /* If value nonzero, this value should replace the entire constructor at this level. */ struct c_expr replacement_value; struct constructor_range_stack *range_stack; char constant; char simple; char implicit; char erroneous; char outer; char incremental; char designated; }; static struct constructor_stack *constructor_stack; /* This stack represents designators from some range designator up to the last designator in the list. */ struct constructor_range_stack { struct constructor_range_stack *next, *prev; struct constructor_stack *stack; tree range_start; tree index; tree range_end; tree fields; }; static struct constructor_range_stack *constructor_range_stack; /* This stack records separate initializers that are nested. Nested initializers can't happen in ANSI C, but GNU C allows them in cases like { ... (struct foo) { ... } ... }. */ struct initializer_stack { struct initializer_stack *next; tree decl; struct constructor_stack *constructor_stack; struct constructor_range_stack *constructor_range_stack; tree elements; struct spelling *spelling; struct spelling *spelling_base; int spelling_size; char top_level; char require_constant_value; char require_constant_elements; }; static struct initializer_stack *initializer_stack; /* Prepare to parse and output the initializer for variable DECL. */ void start_init (tree decl, tree asmspec_tree ATTRIBUTE_UNUSED, int top_level) { const char *locus; struct initializer_stack *p = xmalloc (sizeof (struct initializer_stack)); p->decl = constructor_decl; p->require_constant_value = require_constant_value; p->require_constant_elements = require_constant_elements; p->constructor_stack = constructor_stack; p->constructor_range_stack = constructor_range_stack; p->elements = constructor_elements; p->spelling = spelling; p->spelling_base = spelling_base; p->spelling_size = spelling_size; p->top_level = constructor_top_level; p->next = initializer_stack; initializer_stack = p; constructor_decl = decl; constructor_designated = 0; constructor_top_level = top_level; if (decl != 0 && decl != error_mark_node) { require_constant_value = TREE_STATIC (decl); require_constant_elements = ((TREE_STATIC (decl) || (pedantic && !flag_isoc99)) /* For a scalar, you can always use any value to initialize, even within braces. */ && (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE || TREE_CODE (TREE_TYPE (decl)) == RECORD_TYPE || TREE_CODE (TREE_TYPE (decl)) == UNION_TYPE || TREE_CODE (TREE_TYPE (decl)) == QUAL_UNION_TYPE)); locus = IDENTIFIER_POINTER (DECL_NAME (decl)); } else { require_constant_value = 0; require_constant_elements = 0; locus = "(anonymous)"; } constructor_stack = 0; constructor_range_stack = 0; missing_braces_mentioned = 0; spelling_base = 0; spelling_size = 0; RESTORE_SPELLING_DEPTH (0); if (locus) push_string (locus); } void finish_init (void) { struct initializer_stack *p = initializer_stack; /* Free the whole constructor stack of this initializer. */ while (constructor_stack) { struct constructor_stack *q = constructor_stack; constructor_stack = q->next; free (q); } gcc_assert (!constructor_range_stack); /* Pop back to the data of the outer initializer (if any). */ free (spelling_base); constructor_decl = p->decl; require_constant_value = p->require_constant_value; require_constant_elements = p->require_constant_elements; constructor_stack = p->constructor_stack; constructor_range_stack = p->constructor_range_stack; constructor_elements = p->elements; spelling = p->spelling; spelling_base = p->spelling_base; spelling_size = p->spelling_size; constructor_top_level = p->top_level; initializer_stack = p->next; free (p); } /* Call here when we see the initializer is surrounded by braces. This is instead of a call to push_init_level; it is matched by a call to pop_init_level. TYPE is the type to initialize, for a constructor expression. For an initializer for a decl, TYPE is zero. */ void really_start_incremental_init (tree type) { struct constructor_stack *p = XNEW (struct constructor_stack); if (type == 0) type = TREE_TYPE (constructor_decl); if (targetm.vector_opaque_p (type)) error ("opaque vector types cannot be initialized"); p->type = constructor_type; p->fields = constructor_fields; p->index = constructor_index; p->max_index = constructor_max_index; p->unfilled_index = constructor_unfilled_index; p->unfilled_fields = constructor_unfilled_fields; p->bit_index = constructor_bit_index; p->elements = constructor_elements; p->constant = constructor_constant; p->simple = constructor_simple; p->erroneous = constructor_erroneous; p->pending_elts = constructor_pending_elts; p->depth = constructor_depth; p->replacement_value.value = 0; p->replacement_value.original_code = ERROR_MARK; p->implicit = 0; p->range_stack = 0; p->outer = 0; p->incremental = constructor_incremental; p->designated = constructor_designated; p->next = 0; constructor_stack = p; constructor_constant = 1; constructor_simple = 1; constructor_depth = SPELLING_DEPTH (); constructor_elements = 0; constructor_pending_elts = 0; constructor_type = type; constructor_incremental = 1; constructor_designated = 0; designator_depth = 0; designator_errorneous = 0; if (TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) { constructor_fields = TYPE_FIELDS (constructor_type); /* Skip any nameless bit fields at the beginning. */ while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) && DECL_NAME (constructor_fields) == 0) constructor_fields = TREE_CHAIN (constructor_fields); constructor_unfilled_fields = constructor_fields; constructor_bit_index = bitsize_zero_node; } else if (TREE_CODE (constructor_type) == ARRAY_TYPE) { if (TYPE_DOMAIN (constructor_type)) { constructor_max_index = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); /* Detect non-empty initializations of zero-length arrays. */ if (constructor_max_index == NULL_TREE && TYPE_SIZE (constructor_type)) constructor_max_index = build_int_cst (NULL_TREE, -1); /* constructor_max_index needs to be an INTEGER_CST. Attempts to initialize VLAs will cause a proper error; avoid tree checking errors as well by setting a safe value. */ if (constructor_max_index && TREE_CODE (constructor_max_index) != INTEGER_CST) constructor_max_index = build_int_cst (NULL_TREE, -1); constructor_index = convert (bitsizetype, TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); } else { constructor_index = bitsize_zero_node; constructor_max_index = NULL_TREE; } constructor_unfilled_index = constructor_index; } else if (TREE_CODE (constructor_type) == VECTOR_TYPE) { /* Vectors are like simple fixed-size arrays. */ constructor_max_index = build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); constructor_index = convert (bitsizetype, bitsize_zero_node); constructor_unfilled_index = constructor_index; } else { /* Handle the case of int x = {5}; */ constructor_fields = constructor_type; constructor_unfilled_fields = constructor_type; } } /* Push down into a subobject, for initialization. If this is for an explicit set of braces, IMPLICIT is 0. If it is because the next element belongs at a lower level, IMPLICIT is 1 (or 2 if the push is because of designator list). */ void push_init_level (int implicit) { struct constructor_stack *p; tree value = NULL_TREE; /* If we've exhausted any levels that didn't have braces, pop them now. */ while (constructor_stack->implicit) { if ((TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) && constructor_fields == 0) process_init_element (pop_init_level (1)); else if (TREE_CODE (constructor_type) == ARRAY_TYPE && constructor_max_index && tree_int_cst_lt (constructor_max_index, constructor_index)) process_init_element (pop_init_level (1)); else break; } /* Unless this is an explicit brace, we need to preserve previous content if any. */ if (implicit) { if ((TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) && constructor_fields) value = find_init_member (constructor_fields); else if (TREE_CODE (constructor_type) == ARRAY_TYPE) value = find_init_member (constructor_index); } p = XNEW (struct constructor_stack); p->type = constructor_type; p->fields = constructor_fields; p->index = constructor_index; p->max_index = constructor_max_index; p->unfilled_index = constructor_unfilled_index; p->unfilled_fields = constructor_unfilled_fields; p->bit_index = constructor_bit_index; p->elements = constructor_elements; p->constant = constructor_constant; p->simple = constructor_simple; p->erroneous = constructor_erroneous; p->pending_elts = constructor_pending_elts; p->depth = constructor_depth; p->replacement_value.value = 0; p->replacement_value.original_code = ERROR_MARK; p->implicit = implicit; p->outer = 0; p->incremental = constructor_incremental; p->designated = constructor_designated; p->next = constructor_stack; p->range_stack = 0; constructor_stack = p; constructor_constant = 1; constructor_simple = 1; constructor_depth = SPELLING_DEPTH (); constructor_elements = 0; constructor_incremental = 1; constructor_designated = 0; constructor_pending_elts = 0; if (!implicit) { p->range_stack = constructor_range_stack; constructor_range_stack = 0; designator_depth = 0; designator_errorneous = 0; } /* Don't die if an entire brace-pair level is superfluous in the containing level. */ if (constructor_type == 0) ; else if (TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) { /* Don't die if there are extra init elts at the end. */ if (constructor_fields == 0) constructor_type = 0; else { constructor_type = TREE_TYPE (constructor_fields); push_member_name (constructor_fields); constructor_depth++; } } else if (TREE_CODE (constructor_type) == ARRAY_TYPE) { constructor_type = TREE_TYPE (constructor_type); push_array_bounds (tree_low_cst (constructor_index, 0)); constructor_depth++; } if (constructor_type == 0) { error_init ("extra brace group at end of initializer"); constructor_fields = 0; constructor_unfilled_fields = 0; return; } if (value && TREE_CODE (value) == CONSTRUCTOR) { constructor_constant = TREE_CONSTANT (value); constructor_simple = TREE_STATIC (value); constructor_elements = CONSTRUCTOR_ELTS (value); if (constructor_elements && (TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == ARRAY_TYPE)) set_nonincremental_init (); } if (implicit == 1 && warn_missing_braces && !missing_braces_mentioned) { missing_braces_mentioned = 1; warning_init ("missing braces around initializer"); } if (TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) { constructor_fields = TYPE_FIELDS (constructor_type); /* Skip any nameless bit fields at the beginning. */ while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) && DECL_NAME (constructor_fields) == 0) constructor_fields = TREE_CHAIN (constructor_fields); constructor_unfilled_fields = constructor_fields; constructor_bit_index = bitsize_zero_node; } else if (TREE_CODE (constructor_type) == VECTOR_TYPE) { /* Vectors are like simple fixed-size arrays. */ constructor_max_index = build_int_cst (NULL_TREE, TYPE_VECTOR_SUBPARTS (constructor_type) - 1); constructor_index = convert (bitsizetype, integer_zero_node); constructor_unfilled_index = constructor_index; } else if (TREE_CODE (constructor_type) == ARRAY_TYPE) { if (TYPE_DOMAIN (constructor_type)) { constructor_max_index = TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type)); /* Detect non-empty initializations of zero-length arrays. */ if (constructor_max_index == NULL_TREE && TYPE_SIZE (constructor_type)) constructor_max_index = build_int_cst (NULL_TREE, -1); /* constructor_max_index needs to be an INTEGER_CST. Attempts to initialize VLAs will cause a proper error; avoid tree checking errors as well by setting a safe value. */ if (constructor_max_index && TREE_CODE (constructor_max_index) != INTEGER_CST) constructor_max_index = build_int_cst (NULL_TREE, -1); constructor_index = convert (bitsizetype, TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); } else constructor_index = bitsize_zero_node; constructor_unfilled_index = constructor_index; if (value && TREE_CODE (value) == STRING_CST) { /* We need to split the char/wchar array into individual characters, so that we don't have to special case it everywhere. */ set_nonincremental_init_from_string (value); } } else { if (constructor_type != error_mark_node) warning_init ("braces around scalar initializer"); constructor_fields = constructor_type; constructor_unfilled_fields = constructor_type; } } /* At the end of an implicit or explicit brace level, finish up that level of constructor. If a single expression with redundant braces initialized that level, return the c_expr structure for that expression. Otherwise, the original_code element is set to ERROR_MARK. If we were outputting the elements as they are read, return 0 as the value from inner levels (process_init_element ignores that), but return error_mark_node as the value from the outermost level (that's what we want to put in DECL_INITIAL). Otherwise, return a CONSTRUCTOR expression as the value. */ struct c_expr pop_init_level (int implicit) { struct constructor_stack *p; struct c_expr ret; ret.value = 0; ret.original_code = ERROR_MARK; if (implicit == 0) { /* When we come to an explicit close brace, pop any inner levels that didn't have explicit braces. */ while (constructor_stack->implicit) process_init_element (pop_init_level (1)); gcc_assert (!constructor_range_stack); } /* Now output all pending elements. */ constructor_incremental = 1; output_pending_init_elements (1); p = constructor_stack; /* Error for initializing a flexible array member, or a zero-length array member in an inappropriate context. */ if (constructor_type && constructor_fields && TREE_CODE (constructor_type) == ARRAY_TYPE && TYPE_DOMAIN (constructor_type) && !TYPE_MAX_VALUE (TYPE_DOMAIN (constructor_type))) { /* Silently discard empty initializations. The parser will already have pedwarned for empty brackets. */ if (integer_zerop (constructor_unfilled_index)) constructor_type = NULL_TREE; else { gcc_assert (!TYPE_SIZE (constructor_type)); if (constructor_depth > 2) error_init ("initialization of flexible array member in a nested context"); else if (pedantic) pedwarn_init ("initialization of a flexible array member"); /* We have already issued an error message for the existence of a flexible array member not at the end of the structure. Discard the initializer so that we do not abort later. */ if (TREE_CHAIN (constructor_fields) != NULL_TREE) constructor_type = NULL_TREE; } } /* Warn when some struct elements are implicitly initialized to zero. */ if (warn_missing_field_initializers && constructor_type && TREE_CODE (constructor_type) == RECORD_TYPE && constructor_unfilled_fields) { /* Do not warn for flexible array members or zero-length arrays. */ while (constructor_unfilled_fields && (!DECL_SIZE (constructor_unfilled_fields) || integer_zerop (DECL_SIZE (constructor_unfilled_fields)))) constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); /* Do not warn if this level of the initializer uses member designators; it is likely to be deliberate. */ if (constructor_unfilled_fields && !constructor_designated) { push_member_name (constructor_unfilled_fields); warning_init ("missing initializer"); RESTORE_SPELLING_DEPTH (constructor_depth); } } /* Pad out the end of the structure. */ if (p->replacement_value.value) /* If this closes a superfluous brace pair, just pass out the element between them. */ ret = p->replacement_value; else if (constructor_type == 0) ; else if (TREE_CODE (constructor_type) != RECORD_TYPE && TREE_CODE (constructor_type) != UNION_TYPE && TREE_CODE (constructor_type) != ARRAY_TYPE && TREE_CODE (constructor_type) != VECTOR_TYPE) { /* A nonincremental scalar initializer--just return the element, after verifying there is just one. */ if (constructor_elements == 0) { if (!constructor_erroneous) error_init ("empty scalar initializer"); ret.value = error_mark_node; } else if (TREE_CHAIN (constructor_elements) != 0) { error_init ("extra elements in scalar initializer"); ret.value = TREE_VALUE (constructor_elements); } else ret.value = TREE_VALUE (constructor_elements); } else { if (constructor_erroneous) ret.value = error_mark_node; else { ret.value = build_constructor (constructor_type, nreverse (constructor_elements)); if (constructor_constant) TREE_CONSTANT (ret.value) = TREE_INVARIANT (ret.value) = 1; if (constructor_constant && constructor_simple) TREE_STATIC (ret.value) = 1; } } constructor_type = p->type; constructor_fields = p->fields; constructor_index = p->index; constructor_max_index = p->max_index; constructor_unfilled_index = p->unfilled_index; constructor_unfilled_fields = p->unfilled_fields; constructor_bit_index = p->bit_index; constructor_elements = p->elements; constructor_constant = p->constant; constructor_simple = p->simple; constructor_erroneous = p->erroneous; constructor_incremental = p->incremental; constructor_designated = p->designated; constructor_pending_elts = p->pending_elts; constructor_depth = p->depth; if (!p->implicit) constructor_range_stack = p->range_stack; RESTORE_SPELLING_DEPTH (constructor_depth); constructor_stack = p->next; free (p); if (ret.value == 0) { if (constructor_stack == 0) { ret.value = error_mark_node; return ret; } return ret; } return ret; } /* Common handling for both array range and field name designators. ARRAY argument is nonzero for array ranges. Returns zero for success. */ static int set_designator (int array) { tree subtype; enum tree_code subcode; /* Don't die if an entire brace-pair level is superfluous in the containing level. */ if (constructor_type == 0) return 1; /* If there were errors in this designator list already, bail out silently. */ if (designator_errorneous) return 1; if (!designator_depth) { gcc_assert (!constructor_range_stack); /* Designator list starts at the level of closest explicit braces. */ while (constructor_stack->implicit) process_init_element (pop_init_level (1)); constructor_designated = 1; return 0; } switch (TREE_CODE (constructor_type)) { case RECORD_TYPE: case UNION_TYPE: subtype = TREE_TYPE (constructor_fields); if (subtype != error_mark_node) subtype = TYPE_MAIN_VARIANT (subtype); break; case ARRAY_TYPE: subtype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); break; default: gcc_unreachable (); } subcode = TREE_CODE (subtype); if (array && subcode != ARRAY_TYPE) { error_init ("array index in non-array initializer"); return 1; } else if (!array && subcode != RECORD_TYPE && subcode != UNION_TYPE) { error_init ("field name not in record or union initializer"); return 1; } constructor_designated = 1; push_init_level (2); return 0; } /* If there are range designators in designator list, push a new designator to constructor_range_stack. RANGE_END is end of such stack range or NULL_TREE if there is no range designator at this level. */ static void push_range_stack (tree range_end) { struct constructor_range_stack *p; p = GGC_NEW (struct constructor_range_stack); p->prev = constructor_range_stack; p->next = 0; p->fields = constructor_fields; p->range_start = constructor_index; p->index = constructor_index; p->stack = constructor_stack; p->range_end = range_end; if (constructor_range_stack) constructor_range_stack->next = p; constructor_range_stack = p; } /* Within an array initializer, specify the next index to be initialized. FIRST is that index. If LAST is nonzero, then initialize a range of indices, running from FIRST through LAST. */ void set_init_index (tree first, tree last) { if (set_designator (1)) return; designator_errorneous = 1; if (!INTEGRAL_TYPE_P (TREE_TYPE (first)) || (last && !INTEGRAL_TYPE_P (TREE_TYPE (last)))) { error_init ("array index in initializer not of integer type"); return; } if (TREE_CODE (first) != INTEGER_CST) error_init ("nonconstant array index in initializer"); else if (last != 0 && TREE_CODE (last) != INTEGER_CST) error_init ("nonconstant array index in initializer"); else if (TREE_CODE (constructor_type) != ARRAY_TYPE) error_init ("array index in non-array initializer"); else if (tree_int_cst_sgn (first) == -1) error_init ("array index in initializer exceeds array bounds"); else if (constructor_max_index && tree_int_cst_lt (constructor_max_index, first)) error_init ("array index in initializer exceeds array bounds"); else { constructor_index = convert (bitsizetype, first); if (last) { if (tree_int_cst_equal (first, last)) last = 0; else if (tree_int_cst_lt (last, first)) { error_init ("empty index range in initializer"); last = 0; } else { last = convert (bitsizetype, last); if (constructor_max_index != 0 && tree_int_cst_lt (constructor_max_index, last)) { error_init ("array index range in initializer exceeds array bounds"); last = 0; } } } designator_depth++; designator_errorneous = 0; if (constructor_range_stack || last) push_range_stack (last); } } /* Within a struct initializer, specify the next field to be initialized. */ void set_init_label (tree fieldname) { tree tail; if (set_designator (0)) return; designator_errorneous = 1; if (TREE_CODE (constructor_type) != RECORD_TYPE && TREE_CODE (constructor_type) != UNION_TYPE) { error_init ("field name not in record or union initializer"); return; } for (tail = TYPE_FIELDS (constructor_type); tail; tail = TREE_CHAIN (tail)) { if (DECL_NAME (tail) == fieldname) break; } if (tail == 0) error ("unknown field %qE specified in initializer", fieldname); else { constructor_fields = tail; designator_depth++; designator_errorneous = 0; if (constructor_range_stack) push_range_stack (NULL_TREE); } } /* Add a new initializer to the tree of pending initializers. PURPOSE identifies the initializer, either array index or field in a structure. VALUE is the value of that index or field. */ static void add_pending_init (tree purpose, tree value) { struct init_node *p, **q, *r; q = &constructor_pending_elts; p = 0; if (TREE_CODE (constructor_type) == ARRAY_TYPE) { while (*q != 0) { p = *q; if (tree_int_cst_lt (purpose, p->purpose)) q = &p->left; else if (tree_int_cst_lt (p->purpose, purpose)) q = &p->right; else { if (TREE_SIDE_EFFECTS (p->value)) warning_init ("initialized field with side-effects overwritten"); p->value = value; return; } } } else { tree bitpos; bitpos = bit_position (purpose); while (*q != NULL) { p = *q; if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) q = &p->left; else if (p->purpose != purpose) q = &p->right; else { if (TREE_SIDE_EFFECTS (p->value)) warning_init ("initialized field with side-effects overwritten"); p->value = value; return; } } } r = GGC_NEW (struct init_node); r->purpose = purpose; r->value = value; *q = r; r->parent = p; r->left = 0; r->right = 0; r->balance = 0; while (p) { struct init_node *s; if (r == p->left) { if (p->balance == 0) p->balance = -1; else if (p->balance < 0) { if (r->balance < 0) { /* L rotation. */ p->left = r->right; if (p->left) p->left->parent = p; r->right = p; p->balance = 0; r->balance = 0; s = p->parent; p->parent = r; r->parent = s; if (s) { if (s->left == p) s->left = r; else s->right = r; } else constructor_pending_elts = r; } else { /* LR rotation. */ struct init_node *t = r->right; r->right = t->left; if (r->right) r->right->parent = r; t->left = r; p->left = t->right; if (p->left) p->left->parent = p; t->right = p; p->balance = t->balance < 0; r->balance = -(t->balance > 0); t->balance = 0; s = p->parent; p->parent = t; r->parent = t; t->parent = s; if (s) { if (s->left == p) s->left = t; else s->right = t; } else constructor_pending_elts = t; } break; } else { /* p->balance == +1; growth of left side balances the node. */ p->balance = 0; break; } } else /* r == p->right */ { if (p->balance == 0) /* Growth propagation from right side. */ p->balance++; else if (p->balance > 0) { if (r->balance > 0) { /* R rotation. */ p->right = r->left; if (p->right) p->right->parent = p; r->left = p; p->balance = 0; r->balance = 0; s = p->parent; p->parent = r; r->parent = s; if (s) { if (s->left == p) s->left = r; else s->right = r; } else constructor_pending_elts = r; } else /* r->balance == -1 */ { /* RL rotation */ struct init_node *t = r->left; r->left = t->right; if (r->left) r->left->parent = r; t->right = r; p->right = t->left; if (p->right) p->right->parent = p; t->left = p; r->balance = (t->balance < 0); p->balance = -(t->balance > 0); t->balance = 0; s = p->parent; p->parent = t; r->parent = t; t->parent = s; if (s) { if (s->left == p) s->left = t; else s->right = t; } else constructor_pending_elts = t; } break; } else { /* p->balance == -1; growth of right side balances the node. */ p->balance = 0; break; } } r = p; p = p->parent; } } /* Build AVL tree from a sorted chain. */ static void set_nonincremental_init (void) { tree chain; if (TREE_CODE (constructor_type) != RECORD_TYPE && TREE_CODE (constructor_type) != ARRAY_TYPE) return; for (chain = constructor_elements; chain; chain = TREE_CHAIN (chain)) add_pending_init (TREE_PURPOSE (chain), TREE_VALUE (chain)); constructor_elements = 0; if (TREE_CODE (constructor_type) == RECORD_TYPE) { constructor_unfilled_fields = TYPE_FIELDS (constructor_type); /* Skip any nameless bit fields at the beginning. */ while (constructor_unfilled_fields != 0 && DECL_C_BIT_FIELD (constructor_unfilled_fields) && DECL_NAME (constructor_unfilled_fields) == 0) constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); } else if (TREE_CODE (constructor_type) == ARRAY_TYPE) { if (TYPE_DOMAIN (constructor_type)) constructor_unfilled_index = convert (bitsizetype, TYPE_MIN_VALUE (TYPE_DOMAIN (constructor_type))); else constructor_unfilled_index = bitsize_zero_node; } constructor_incremental = 0; } /* Build AVL tree from a string constant. */ static void set_nonincremental_init_from_string (tree str) { tree value, purpose, type; HOST_WIDE_INT val[2]; const char *p, *end; int byte, wchar_bytes, charwidth, bitpos; gcc_assert (TREE_CODE (constructor_type) == ARRAY_TYPE); if (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) == TYPE_PRECISION (char_type_node)) wchar_bytes = 1; else { gcc_assert (TYPE_PRECISION (TREE_TYPE (TREE_TYPE (str))) == TYPE_PRECISION (wchar_type_node)); wchar_bytes = TYPE_PRECISION (wchar_type_node) / BITS_PER_UNIT; } charwidth = TYPE_PRECISION (char_type_node); type = TREE_TYPE (constructor_type); p = TREE_STRING_POINTER (str); end = p + TREE_STRING_LENGTH (str); for (purpose = bitsize_zero_node; p < end && !tree_int_cst_lt (constructor_max_index, purpose); purpose = size_binop (PLUS_EXPR, purpose, bitsize_one_node)) { if (wchar_bytes == 1) { val[1] = (unsigned char) *p++; val[0] = 0; } else { val[0] = 0; val[1] = 0; for (byte = 0; byte < wchar_bytes; byte++) { if (BYTES_BIG_ENDIAN) bitpos = (wchar_bytes - byte - 1) * charwidth; else bitpos = byte * charwidth; val[bitpos < HOST_BITS_PER_WIDE_INT] |= ((unsigned HOST_WIDE_INT) ((unsigned char) *p++)) << (bitpos % HOST_BITS_PER_WIDE_INT); } } if (!TYPE_UNSIGNED (type)) { bitpos = ((wchar_bytes - 1) * charwidth) + HOST_BITS_PER_CHAR; if (bitpos < HOST_BITS_PER_WIDE_INT) { if (val[1] & (((HOST_WIDE_INT) 1) << (bitpos - 1))) { val[1] |= ((HOST_WIDE_INT) -1) << bitpos; val[0] = -1; } } else if (bitpos == HOST_BITS_PER_WIDE_INT) { if (val[1] < 0) val[0] = -1; } else if (val[0] & (((HOST_WIDE_INT) 1) << (bitpos - 1 - HOST_BITS_PER_WIDE_INT))) val[0] |= ((HOST_WIDE_INT) -1) << (bitpos - HOST_BITS_PER_WIDE_INT); } value = build_int_cst_wide (type, val[1], val[0]); add_pending_init (purpose, value); } constructor_incremental = 0; } /* Return value of FIELD in pending initializer or zero if the field was not initialized yet. */ static tree find_init_member (tree field) { struct init_node *p; if (TREE_CODE (constructor_type) == ARRAY_TYPE) { if (constructor_incremental && tree_int_cst_lt (field, constructor_unfilled_index)) set_nonincremental_init (); p = constructor_pending_elts; while (p) { if (tree_int_cst_lt (field, p->purpose)) p = p->left; else if (tree_int_cst_lt (p->purpose, field)) p = p->right; else return p->value; } } else if (TREE_CODE (constructor_type) == RECORD_TYPE) { tree bitpos = bit_position (field); if (constructor_incremental && (!constructor_unfilled_fields || tree_int_cst_lt (bitpos, bit_position (constructor_unfilled_fields)))) set_nonincremental_init (); p = constructor_pending_elts; while (p) { if (field == p->purpose) return p->value; else if (tree_int_cst_lt (bitpos, bit_position (p->purpose))) p = p->left; else p = p->right; } } else if (TREE_CODE (constructor_type) == UNION_TYPE) { if (constructor_elements && TREE_PURPOSE (constructor_elements) == field) return TREE_VALUE (constructor_elements); } return 0; } /* "Output" the next constructor element. At top level, really output it to assembler code now. Otherwise, collect it in a list from which we will make a CONSTRUCTOR. TYPE is the data type that the containing data type wants here. FIELD is the field (a FIELD_DECL) or the index that this element fills. If VALUE is a string constant, STRICT_STRING is true if it is unparenthesized or we should not warn here for it being parenthesized. For other types of VALUE, STRICT_STRING is not used. PENDING if non-nil means output pending elements that belong right after this element. (PENDING is normally 1; it is 0 while outputting pending elements, to avoid recursion.) */ static void output_init_element (tree value, bool strict_string, tree type, tree field, int pending) { if (type == error_mark_node || value == error_mark_node) { constructor_erroneous = 1; return; } if (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE || (TREE_CODE (TREE_TYPE (value)) == ARRAY_TYPE && !(TREE_CODE (value) == STRING_CST && TREE_CODE (type) == ARRAY_TYPE && INTEGRAL_TYPE_P (TREE_TYPE (type))) && !comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (value)), TYPE_MAIN_VARIANT (type)))) value = default_conversion (value); if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR && require_constant_value && !flag_isoc99 && pending) { /* As an extension, allow initializing objects with static storage duration with compound literals (which are then treated just as the brace enclosed list they contain). */ tree decl = COMPOUND_LITERAL_EXPR_DECL (value); value = DECL_INITIAL (decl); } if (value == error_mark_node) constructor_erroneous = 1; else if (!TREE_CONSTANT (value)) constructor_constant = 0; else if (!initializer_constant_valid_p (value, TREE_TYPE (value)) || ((TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) && DECL_C_BIT_FIELD (field) && TREE_CODE (value) != INTEGER_CST)) constructor_simple = 0; if (!initializer_constant_valid_p (value, TREE_TYPE (value))) { if (require_constant_value) { error_init ("initializer element is not constant"); value = error_mark_node; } else if (require_constant_elements) pedwarn ("initializer element is not computable at load time"); } /* If this field is empty (and not at the end of structure), don't do anything other than checking the initializer. */ if (field && (TREE_TYPE (field) == error_mark_node || (COMPLETE_TYPE_P (TREE_TYPE (field)) && integer_zerop (TYPE_SIZE (TREE_TYPE (field))) && (TREE_CODE (constructor_type) == ARRAY_TYPE || TREE_CHAIN (field))))) return; value = digest_init (type, value, strict_string, require_constant_value); if (value == error_mark_node) { constructor_erroneous = 1; return; } /* If this element doesn't come next in sequence, put it on constructor_pending_elts. */ if (TREE_CODE (constructor_type) == ARRAY_TYPE && (!constructor_incremental || !tree_int_cst_equal (field, constructor_unfilled_index))) { if (constructor_incremental && tree_int_cst_lt (field, constructor_unfilled_index)) set_nonincremental_init (); add_pending_init (field, value); return; } else if (TREE_CODE (constructor_type) == RECORD_TYPE && (!constructor_incremental || field != constructor_unfilled_fields)) { /* We do this for records but not for unions. In a union, no matter which field is specified, it can be initialized right away since it starts at the beginning of the union. */ if (constructor_incremental) { if (!constructor_unfilled_fields) set_nonincremental_init (); else { tree bitpos, unfillpos; bitpos = bit_position (field); unfillpos = bit_position (constructor_unfilled_fields); if (tree_int_cst_lt (bitpos, unfillpos)) set_nonincremental_init (); } } add_pending_init (field, value); return; } else if (TREE_CODE (constructor_type) == UNION_TYPE && constructor_elements) { if (TREE_SIDE_EFFECTS (TREE_VALUE (constructor_elements))) warning_init ("initialized field with side-effects overwritten"); /* We can have just one union field set. */ constructor_elements = 0; } /* Otherwise, output this element either to constructor_elements or to the assembler file. */ if (field && TREE_CODE (field) == INTEGER_CST) field = copy_node (field); constructor_elements = tree_cons (field, value, constructor_elements); /* Advance the variable that indicates sequential elements output. */ if (TREE_CODE (constructor_type) == ARRAY_TYPE) constructor_unfilled_index = size_binop (PLUS_EXPR, constructor_unfilled_index, bitsize_one_node); else if (TREE_CODE (constructor_type) == RECORD_TYPE) { constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); /* Skip any nameless bit fields. */ while (constructor_unfilled_fields != 0 && DECL_C_BIT_FIELD (constructor_unfilled_fields) && DECL_NAME (constructor_unfilled_fields) == 0) constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); } else if (TREE_CODE (constructor_type) == UNION_TYPE) constructor_unfilled_fields = 0; /* Now output any pending elements which have become next. */ if (pending) output_pending_init_elements (0); } /* Output any pending elements which have become next. As we output elements, constructor_unfilled_{fields,index} advances, which may cause other elements to become next; if so, they too are output. If ALL is 0, we return when there are no more pending elements to output now. If ALL is 1, we output space as necessary so that we can output all the pending elements. */ static void output_pending_init_elements (int all) { struct init_node *elt = constructor_pending_elts; tree next; retry: /* Look through the whole pending tree. If we find an element that should be output now, output it. Otherwise, set NEXT to the element that comes first among those still pending. */ next = 0; while (elt) { if (TREE_CODE (constructor_type) == ARRAY_TYPE) { if (tree_int_cst_equal (elt->purpose, constructor_unfilled_index)) output_init_element (elt->value, true, TREE_TYPE (constructor_type), constructor_unfilled_index, 0); else if (tree_int_cst_lt (constructor_unfilled_index, elt->purpose)) { /* Advance to the next smaller node. */ if (elt->left) elt = elt->left; else { /* We have reached the smallest node bigger than the current unfilled index. Fill the space first. */ next = elt->purpose; break; } } else { /* Advance to the next bigger node. */ if (elt->right) elt = elt->right; else { /* We have reached the biggest node in a subtree. Find the parent of it, which is the next bigger node. */ while (elt->parent && elt->parent->right == elt) elt = elt->parent; elt = elt->parent; if (elt && tree_int_cst_lt (constructor_unfilled_index, elt->purpose)) { next = elt->purpose; break; } } } } else if (TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) { tree ctor_unfilled_bitpos, elt_bitpos; /* If the current record is complete we are done. */ if (constructor_unfilled_fields == 0) break; ctor_unfilled_bitpos = bit_position (constructor_unfilled_fields); elt_bitpos = bit_position (elt->purpose); /* We can't compare fields here because there might be empty fields in between. */ if (tree_int_cst_equal (elt_bitpos, ctor_unfilled_bitpos)) { constructor_unfilled_fields = elt->purpose; output_init_element (elt->value, true, TREE_TYPE (elt->purpose), elt->purpose, 0); } else if (tree_int_cst_lt (ctor_unfilled_bitpos, elt_bitpos)) { /* Advance to the next smaller node. */ if (elt->left) elt = elt->left; else { /* We have reached the smallest node bigger than the current unfilled field. Fill the space first. */ next = elt->purpose; break; } } else { /* Advance to the next bigger node. */ if (elt->right) elt = elt->right; else { /* We have reached the biggest node in a subtree. Find the parent of it, which is the next bigger node. */ while (elt->parent && elt->parent->right == elt) elt = elt->parent; elt = elt->parent; if (elt && (tree_int_cst_lt (ctor_unfilled_bitpos, bit_position (elt->purpose)))) { next = elt->purpose; break; } } } } } /* Ordinarily return, but not if we want to output all and there are elements left. */ if (!(all && next != 0)) return; /* If it's not incremental, just skip over the gap, so that after jumping to retry we will output the next successive element. */ if (TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) constructor_unfilled_fields = next; else if (TREE_CODE (constructor_type) == ARRAY_TYPE) constructor_unfilled_index = next; /* ELT now points to the node in the pending tree with the next initializer to output. */ goto retry; } /* Add one non-braced element to the current constructor level. This adjusts the current position within the constructor's type. This may also start or terminate implicit levels to handle a partly-braced initializer. Once this has found the correct level for the new element, it calls output_init_element. */ void process_init_element (struct c_expr value) { tree orig_value = value.value; int string_flag = orig_value != 0 && TREE_CODE (orig_value) == STRING_CST; bool strict_string = value.original_code == STRING_CST; designator_depth = 0; designator_errorneous = 0; /* Handle superfluous braces around string cst as in char x[] = {"foo"}; */ if (string_flag && constructor_type && TREE_CODE (constructor_type) == ARRAY_TYPE && INTEGRAL_TYPE_P (TREE_TYPE (constructor_type)) && integer_zerop (constructor_unfilled_index)) { if (constructor_stack->replacement_value.value) error_init ("excess elements in char array initializer"); constructor_stack->replacement_value = value; return; } if (constructor_stack->replacement_value.value != 0) { error_init ("excess elements in struct initializer"); return; } /* Ignore elements of a brace group if it is entirely superfluous and has already been diagnosed. */ if (constructor_type == 0) return; /* If we've exhausted any levels that didn't have braces, pop them now. */ while (constructor_stack->implicit) { if ((TREE_CODE (constructor_type) == RECORD_TYPE || TREE_CODE (constructor_type) == UNION_TYPE) && constructor_fields == 0) process_init_element (pop_init_level (1)); else if (TREE_CODE (constructor_type) == ARRAY_TYPE && (constructor_max_index == 0 || tree_int_cst_lt (constructor_max_index, constructor_index))) process_init_element (pop_init_level (1)); else break; } /* In the case of [LO ... HI] = VALUE, only evaluate VALUE once. */ if (constructor_range_stack) { /* If value is a compound literal and we'll be just using its content, don't put it into a SAVE_EXPR. */ if (TREE_CODE (value.value) != COMPOUND_LITERAL_EXPR || !require_constant_value || flag_isoc99) value.value = save_expr (value.value); } while (1) { if (TREE_CODE (constructor_type) == RECORD_TYPE) { tree fieldtype; enum tree_code fieldcode; if (constructor_fields == 0) { pedwarn_init ("excess elements in struct initializer"); break; } fieldtype = TREE_TYPE (constructor_fields); if (fieldtype != error_mark_node) fieldtype = TYPE_MAIN_VARIANT (fieldtype); fieldcode = TREE_CODE (fieldtype); /* Error for non-static initialization of a flexible array member. */ if (fieldcode == ARRAY_TYPE && !require_constant_value && TYPE_SIZE (fieldtype) == NULL_TREE && TREE_CHAIN (constructor_fields) == NULL_TREE) { error_init ("non-static initialization of a flexible array member"); break; } /* Accept a string constant to initialize a subarray. */ if (value.value != 0 && fieldcode == ARRAY_TYPE && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) && string_flag) value.value = orig_value; /* Otherwise, if we have come to a subaggregate, and we don't have an element of its type, push into it. */ else if (value.value != 0 && value.value != error_mark_node && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE || fieldcode == UNION_TYPE)) { push_init_level (1); continue; } if (value.value) { push_member_name (constructor_fields); output_init_element (value.value, strict_string, fieldtype, constructor_fields, 1); RESTORE_SPELLING_DEPTH (constructor_depth); } else /* Do the bookkeeping for an element that was directly output as a constructor. */ { /* For a record, keep track of end position of last field. */ if (DECL_SIZE (constructor_fields)) constructor_bit_index = size_binop (PLUS_EXPR, bit_position (constructor_fields), DECL_SIZE (constructor_fields)); /* If the current field was the first one not yet written out, it isn't now, so update. */ if (constructor_unfilled_fields == constructor_fields) { constructor_unfilled_fields = TREE_CHAIN (constructor_fields); /* Skip any nameless bit fields. */ while (constructor_unfilled_fields != 0 && DECL_C_BIT_FIELD (constructor_unfilled_fields) && DECL_NAME (constructor_unfilled_fields) == 0) constructor_unfilled_fields = TREE_CHAIN (constructor_unfilled_fields); } } constructor_fields = TREE_CHAIN (constructor_fields); /* Skip any nameless bit fields at the beginning. */ while (constructor_fields != 0 && DECL_C_BIT_FIELD (constructor_fields) && DECL_NAME (constructor_fields) == 0) constructor_fields = TREE_CHAIN (constructor_fields); } else if (TREE_CODE (constructor_type) == UNION_TYPE) { tree fieldtype; enum tree_code fieldcode; if (constructor_fields == 0) { pedwarn_init ("excess elements in union initializer"); break; } fieldtype = TREE_TYPE (constructor_fields); if (fieldtype != error_mark_node) fieldtype = TYPE_MAIN_VARIANT (fieldtype); fieldcode = TREE_CODE (fieldtype); /* Warn that traditional C rejects initialization of unions. We skip the warning if the value is zero. This is done under the assumption that the zero initializer in user code appears conditioned on e.g. __STDC__ to avoid "missing initializer" warnings and relies on default initialization to zero in the traditional C case. We also skip the warning if the initializer is designated, again on the assumption that this must be conditional on __STDC__ anyway (and we've already complained about the member-designator already). */ if (warn_traditional && !in_system_header && !constructor_designated && !(value.value && (integer_zerop (value.value) || real_zerop (value.value)))) warning ("traditional C rejects initialization of unions"); /* Accept a string constant to initialize a subarray. */ if (value.value != 0 && fieldcode == ARRAY_TYPE && INTEGRAL_TYPE_P (TREE_TYPE (fieldtype)) && string_flag) value.value = orig_value; /* Otherwise, if we have come to a subaggregate, and we don't have an element of its type, push into it. */ else if (value.value != 0 && value.value != error_mark_node && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != fieldtype && (fieldcode == RECORD_TYPE || fieldcode == ARRAY_TYPE || fieldcode == UNION_TYPE)) { push_init_level (1); continue; } if (value.value) { push_member_name (constructor_fields); output_init_element (value.value, strict_string, fieldtype, constructor_fields, 1); RESTORE_SPELLING_DEPTH (constructor_depth); } else /* Do the bookkeeping for an element that was directly output as a constructor. */ { constructor_bit_index = DECL_SIZE (constructor_fields); constructor_unfilled_fields = TREE_CHAIN (constructor_fields); } constructor_fields = 0; } else if (TREE_CODE (constructor_type) == ARRAY_TYPE) { tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); enum tree_code eltcode = TREE_CODE (elttype); /* Accept a string constant to initialize a subarray. */ if (value.value != 0 && eltcode == ARRAY_TYPE && INTEGRAL_TYPE_P (TREE_TYPE (elttype)) && string_flag) value.value = orig_value; /* Otherwise, if we have come to a subaggregate, and we don't have an element of its type, push into it. */ else if (value.value != 0 && value.value != error_mark_node && TYPE_MAIN_VARIANT (TREE_TYPE (value.value)) != elttype && (eltcode == RECORD_TYPE || eltcode == ARRAY_TYPE || eltcode == UNION_TYPE)) { push_init_level (1); continue; } if (constructor_max_index != 0 && (tree_int_cst_lt (constructor_max_index, constructor_index) || integer_all_onesp (constructor_max_index))) { pedwarn_init ("excess elements in array initializer"); break; } /* Now output the actual element. */ if (value.value) { push_array_bounds (tree_low_cst (constructor_index, 0)); output_init_element (value.value, strict_string, elttype, constructor_index, 1); RESTORE_SPELLING_DEPTH (constructor_depth); } constructor_index = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); if (!value.value) /* If we are doing the bookkeeping for an element that was directly output as a constructor, we must update constructor_unfilled_index. */ constructor_unfilled_index = constructor_index; } else if (TREE_CODE (constructor_type) == VECTOR_TYPE) { tree elttype = TYPE_MAIN_VARIANT (TREE_TYPE (constructor_type)); /* Do a basic check of initializer size. Note that vectors always have a fixed size derived from their type. */ if (tree_int_cst_lt (constructor_max_index, constructor_index)) { pedwarn_init ("excess elements in vector initializer"); break; } /* Now output the actual element. */ if (value.value) output_init_element (value.value, strict_string, elttype, constructor_index, 1); constructor_index = size_binop (PLUS_EXPR, constructor_index, bitsize_one_node); if (!value.value) /* If we are doing the bookkeeping for an element that was directly output as a constructor, we must update constructor_unfilled_index. */ constructor_unfilled_index = constructor_index; } /* Handle the sole element allowed in a braced initializer for a scalar variable. */ else if (constructor_type != error_mark_node && constructor_fields == 0) { pedwarn_init ("excess elements in scalar initializer"); break; } else { if (value.value) output_init_element (value.value, strict_string, constructor_type, NULL_TREE, 1); constructor_fields = 0; } /* Handle range initializers either at this level or anywhere higher in the designator stack. */ if (constructor_range_stack) { struct constructor_range_stack *p, *range_stack; int finish = 0; range_stack = constructor_range_stack; constructor_range_stack = 0; while (constructor_stack != range_stack->stack) { gcc_assert (constructor_stack->implicit); process_init_element (pop_init_level (1)); } for (p = range_stack; !p->range_end || tree_int_cst_equal (p->index, p->range_end); p = p->prev) { gcc_assert (constructor_stack->implicit); process_init_element (pop_init_level (1)); } p->index = size_binop (PLUS_EXPR, p->index, bitsize_one_node); if (tree_int_cst_equal (p->index, p->range_end) && !p->prev) finish = 1; while (1) { constructor_index = p->index; constructor_fields = p->fields; if (finish && p->range_end && p->index == p->range_start) { finish = 0; p->prev = 0; } p = p->next; if (!p) break; push_init_level (2); p->stack = constructor_stack; if (p->range_end && tree_int_cst_equal (p->index, p->range_end)) p->index = p->range_start; } if (!finish) constructor_range_stack = range_stack; continue; } break; } constructor_range_stack = 0; } /* Build a complete asm-statement, whose components are a CV_QUALIFIER (guaranteed to be 'volatile' or null) and ARGS (represented using an ASM_EXPR node). */ tree build_asm_stmt (tree cv_qualifier, tree args) { if (!ASM_VOLATILE_P (args) && cv_qualifier) ASM_VOLATILE_P (args) = 1; return add_stmt (args); } /* Build an asm-expr, whose components are a STRING, some OUTPUTS, some INPUTS, and some CLOBBERS. The latter three may be NULL. SIMPLE indicates whether there was anything at all after the string in the asm expression -- asm("blah") and asm("blah" : ) are subtly different. We use a ASM_EXPR node to represent this. */ tree build_asm_expr (tree string, tree outputs, tree inputs, tree clobbers, bool simple) { tree tail; tree args; int i; const char *constraint; const char **oconstraints; bool allows_mem, allows_reg, is_inout; int ninputs, noutputs; ninputs = list_length (inputs); noutputs = list_length (outputs); oconstraints = (const char **) alloca (noutputs * sizeof (const char *)); string = resolve_asm_operand_names (string, outputs, inputs); /* Remove output conversions that change the type but not the mode. */ for (i = 0, tail = outputs; tail; ++i, tail = TREE_CHAIN (tail)) { tree output = TREE_VALUE (tail); /* ??? Really, this should not be here. Users should be using a proper lvalue, dammit. But there's a long history of using casts in the output operands. In cases like longlong.h, this becomes a primitive form of typechecking -- if the cast can be removed, then the output operand had a type of the proper width; otherwise we'll get an error. Gross, but ... */ STRIP_NOPS (output); if (!lvalue_or_else (output, lv_asm)) output = error_mark_node; constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); oconstraints[i] = constraint; if (parse_output_constraint (&constraint, i, ninputs, noutputs, &allows_mem, &allows_reg, &is_inout)) { /* If the operand is going to end up in memory, mark it addressable. */ if (!allows_reg && !c_mark_addressable (output)) output = error_mark_node; } else output = error_mark_node; TREE_VALUE (tail) = output; } /* Perform default conversions on array and function inputs. Don't do this for other types as it would screw up operands expected to be in memory. */ for (i = 0, tail = inputs; tail; ++i, tail = TREE_CHAIN (tail)) { tree input; constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (tail))); input = TREE_VALUE (tail); input = default_function_array_conversion (input); if (parse_input_constraint (&constraint, i, ninputs, noutputs, 0, oconstraints, &allows_mem, &allows_reg)) { /* If the operand is going to end up in memory, mark it addressable. */ if (!allows_reg && allows_mem) { /* Strip the nops as we allow this case. FIXME, this really should be rejected or made deprecated. */ STRIP_NOPS (input); if (!c_mark_addressable (input)) input = error_mark_node; } } else input = error_mark_node; TREE_VALUE (tail) = input; } args = build_stmt (ASM_EXPR, string, outputs, inputs, clobbers); /* Simple asm statements are treated as volatile. */ if (simple) { ASM_VOLATILE_P (args) = 1; ASM_INPUT_P (args) = 1; } return args; } /* Generate a goto statement to LABEL. */ tree c_finish_goto_label (tree label) { tree decl = lookup_label (label); if (!decl) return NULL_TREE; TREE_USED (decl) = 1; return add_stmt (build1 (GOTO_EXPR, void_type_node, decl)); } /* Generate a computed goto statement to EXPR. */ tree c_finish_goto_ptr (tree expr) { if (pedantic) pedwarn ("ISO C forbids %"); expr = convert (ptr_type_node, expr); return add_stmt (build1 (GOTO_EXPR, void_type_node, expr)); } /* Generate a C `return' statement. RETVAL is the expression for what to return, or a null pointer for `return;' with no value. */ tree c_finish_return (tree retval) { tree valtype = TREE_TYPE (TREE_TYPE (current_function_decl)); if (TREE_THIS_VOLATILE (current_function_decl)) warning ("function declared % has a % statement"); if (!retval) { current_function_returns_null = 1; if ((warn_return_type || flag_isoc99) && valtype != 0 && TREE_CODE (valtype) != VOID_TYPE) pedwarn_c99 ("% with no value, in " "function returning non-void"); } else if (valtype == 0 || TREE_CODE (valtype) == VOID_TYPE) { current_function_returns_null = 1; if (pedantic || TREE_CODE (TREE_TYPE (retval)) != VOID_TYPE) pedwarn ("% with a value, in function returning void"); } else { tree t = convert_for_assignment (valtype, retval, ic_return, NULL_TREE, NULL_TREE, 0); tree res = DECL_RESULT (current_function_decl); tree inner; current_function_returns_value = 1; if (t == error_mark_node) return NULL_TREE; inner = t = convert (TREE_TYPE (res), t); /* Strip any conversions, additions, and subtractions, and see if we are returning the address of a local variable. Warn if so. */ while (1) { switch (TREE_CODE (inner)) { case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR: case PLUS_EXPR: inner = TREE_OPERAND (inner, 0); continue; case MINUS_EXPR: /* If the second operand of the MINUS_EXPR has a pointer type (or is converted from it), this may be valid, so don't give a warning. */ { tree op1 = TREE_OPERAND (inner, 1); while (!POINTER_TYPE_P (TREE_TYPE (op1)) && (TREE_CODE (op1) == NOP_EXPR || TREE_CODE (op1) == NON_LVALUE_EXPR || TREE_CODE (op1) == CONVERT_EXPR)) op1 = TREE_OPERAND (op1, 0); if (POINTER_TYPE_P (TREE_TYPE (op1))) break; inner = TREE_OPERAND (inner, 0); continue; } case ADDR_EXPR: inner = TREE_OPERAND (inner, 0); while (REFERENCE_CLASS_P (inner) && TREE_CODE (inner) != INDIRECT_REF) inner = TREE_OPERAND (inner, 0); if (DECL_P (inner) && !DECL_EXTERNAL (inner) && !TREE_STATIC (inner) && DECL_CONTEXT (inner) == current_function_decl) warning ("function returns address of local variable"); break; default: break; } break; } retval = build2 (MODIFY_EXPR, TREE_TYPE (res), res, t); } return add_stmt (build_stmt (RETURN_EXPR, retval)); } struct c_switch { /* The SWITCH_STMT being built. */ tree switch_stmt; /* The original type of the testing expression, i.e. before the default conversion is applied. */ tree orig_type; /* A splay-tree mapping the low element of a case range to the high element, or NULL_TREE if there is no high element. Used to determine whether or not a new case label duplicates an old case label. We need a tree, rather than simply a hash table, because of the GNU case range extension. */ splay_tree cases; /* The next node on the stack. */ struct c_switch *next; }; /* A stack of the currently active switch statements. The innermost switch statement is on the top of the stack. There is no need to mark the stack for garbage collection because it is only active during the processing of the body of a function, and we never collect at that point. */ struct c_switch *c_switch_stack; /* Start a C switch statement, testing expression EXP. Return the new SWITCH_STMT. */ tree c_start_case (tree exp) { enum tree_code code; tree type, orig_type = error_mark_node; struct c_switch *cs; if (exp != error_mark_node) { code = TREE_CODE (TREE_TYPE (exp)); orig_type = TREE_TYPE (exp); if (!INTEGRAL_TYPE_P (orig_type) && code != ERROR_MARK) { error ("switch quantity not an integer"); exp = integer_zero_node; orig_type = error_mark_node; } else { type = TYPE_MAIN_VARIANT (TREE_TYPE (exp)); if (warn_traditional && !in_system_header && (type == long_integer_type_node || type == long_unsigned_type_node)) warning ("% switch expression not converted to " "% in ISO C"); exp = default_conversion (exp); type = TREE_TYPE (exp); } } /* Add this new SWITCH_STMT to the stack. */ cs = XNEW (struct c_switch); cs->switch_stmt = build_stmt (SWITCH_STMT, exp, NULL_TREE, orig_type); cs->orig_type = orig_type; cs->cases = splay_tree_new (case_compare, NULL, NULL); cs->next = c_switch_stack; c_switch_stack = cs; return add_stmt (cs->switch_stmt); } /* Process a case label. */ tree do_case (tree low_value, tree high_value) { tree label = NULL_TREE; if (c_switch_stack) { label = c_add_case_label (c_switch_stack->cases, SWITCH_STMT_COND (c_switch_stack->switch_stmt), c_switch_stack->orig_type, low_value, high_value); if (label == error_mark_node) label = NULL_TREE; } else if (low_value) error ("case label not within a switch statement"); else error ("% label not within a switch statement"); return label; } /* Finish the switch statement. */ void c_finish_case (tree body) { struct c_switch *cs = c_switch_stack; SWITCH_STMT_BODY (cs->switch_stmt) = body; /* Emit warnings as needed. */ c_do_switch_warnings (cs->cases, cs->switch_stmt); /* Pop the stack. */ c_switch_stack = cs->next; splay_tree_delete (cs->cases); XDELETE (cs); } /* Emit an if statement. IF_LOCUS is the location of the 'if'. COND, THEN_BLOCK and ELSE_BLOCK are expressions to be used; ELSE_BLOCK may be null. NESTED_IF is true if THEN_BLOCK contains another IF statement, and was not surrounded with parenthesis. */ void c_finish_if_stmt (location_t if_locus, tree cond, tree then_block, tree else_block, bool nested_if) { tree stmt; /* Diagnose an ambiguous else if if-then-else is nested inside if-then. */ if (warn_parentheses && nested_if && else_block == NULL) { tree inner_if = then_block; /* We know from the grammar productions that there is an IF nested within THEN_BLOCK. Due to labels and c99 conditional declarations, it might not be exactly THEN_BLOCK, but should be the last non-container statement within. */ while (1) switch (TREE_CODE (inner_if)) { case COND_EXPR: goto found; case BIND_EXPR: inner_if = BIND_EXPR_BODY (inner_if); break; case STATEMENT_LIST: inner_if = expr_last (then_block); break; case TRY_FINALLY_EXPR: case TRY_CATCH_EXPR: inner_if = TREE_OPERAND (inner_if, 0); break; default: gcc_unreachable (); } found: if (COND_EXPR_ELSE (inner_if)) warning ("%Hsuggest explicit braces to avoid ambiguous %", &if_locus); } /* Diagnose ";" via the special empty statement node that we create. */ if (extra_warnings) { if (TREE_CODE (then_block) == NOP_EXPR && !TREE_TYPE (then_block)) { if (!else_block) warning ("%Hempty body in an if-statement", EXPR_LOCUS (then_block)); then_block = alloc_stmt_list (); } if (else_block && TREE_CODE (else_block) == NOP_EXPR && !TREE_TYPE (else_block)) { warning ("%Hempty body in an else-statement", EXPR_LOCUS (else_block)); else_block = alloc_stmt_list (); } } stmt = build3 (COND_EXPR, NULL_TREE, cond, then_block, else_block); SET_EXPR_LOCATION (stmt, if_locus); add_stmt (stmt); } /* Emit a general-purpose loop construct. START_LOCUS is the location of the beginning of the loop. COND is the loop condition. COND_IS_FIRST is false for DO loops. INCR is the FOR increment expression. BODY is the statement controlled by the loop. BLAB is the break label. CLAB is the continue label. Everything is allowed to be NULL. */ void c_finish_loop (location_t start_locus, tree cond, tree incr, tree body, tree blab, tree clab, bool cond_is_first) { tree entry = NULL, exit = NULL, t; /* If the condition is zero don't generate a loop construct. */ if (cond && integer_zerop (cond)) { if (cond_is_first) { t = build_and_jump (&blab); SET_EXPR_LOCATION (t, start_locus); add_stmt (t); } } else { tree top = build1 (LABEL_EXPR, void_type_node, NULL_TREE); /* If we have an exit condition, then we build an IF with gotos either out of the loop, or to the top of it. If there's no exit condition, then we just build a jump back to the top. */ exit = build_and_jump (&LABEL_EXPR_LABEL (top)); if (cond && !integer_nonzerop (cond)) { /* Canonicalize the loop condition to the end. This means generating a branch to the loop condition. Reuse the continue label, if possible. */ if (cond_is_first) { if (incr || !clab) { entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE); t = build_and_jump (&LABEL_EXPR_LABEL (entry)); } else t = build1 (GOTO_EXPR, void_type_node, clab); SET_EXPR_LOCATION (t, start_locus); add_stmt (t); } t = build_and_jump (&blab); exit = build3 (COND_EXPR, void_type_node, cond, exit, t); exit = fold (exit); if (cond_is_first) SET_EXPR_LOCATION (exit, start_locus); else SET_EXPR_LOCATION (exit, input_location); } add_stmt (top); } if (body) add_stmt (body); if (clab) add_stmt (build1 (LABEL_EXPR, void_type_node, clab)); if (incr) add_stmt (incr); if (entry) add_stmt (entry); if (exit) add_stmt (exit); if (blab) add_stmt (build1 (LABEL_EXPR, void_type_node, blab)); } tree c_finish_bc_stmt (tree *label_p, bool is_break) { bool skip; tree label = *label_p; /* In switch statements break is sometimes stylistically used after a return statement. This can lead to spurious warnings about control reaching the end of a non-void function when it is inlined. Note that we are calling block_may_fallthru with language specific tree nodes; this works because block_may_fallthru returns true when given something it does not understand. */ skip = !block_may_fallthru (cur_stmt_list); if (!label) { if (!skip) *label_p = label = create_artificial_label (); } else if (TREE_CODE (label) != LABEL_DECL) { if (is_break) error ("break statement not within loop or switch"); else error ("continue statement not within a loop"); return NULL_TREE; } if (skip) return NULL_TREE; return add_stmt (build1 (GOTO_EXPR, void_type_node, label)); } /* A helper routine for c_process_expr_stmt and c_finish_stmt_expr. */ static void emit_side_effect_warnings (tree expr) { if (expr == error_mark_node) ; else if (!TREE_SIDE_EFFECTS (expr)) { if (!VOID_TYPE_P (TREE_TYPE (expr)) && !TREE_NO_WARNING (expr)) warning ("%Hstatement with no effect", EXPR_HAS_LOCATION (expr) ? EXPR_LOCUS (expr) : &input_location); } else if (warn_unused_value) warn_if_unused_value (expr, input_location); } /* Process an expression as if it were a complete statement. Emit diagnostics, but do not call ADD_STMT. */ tree c_process_expr_stmt (tree expr) { if (!expr) return NULL_TREE; /* Do default conversion if safe and possibly important, in case within ({...}). */ if ((TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE && (flag_isoc99 || lvalue_p (expr))) || TREE_CODE (TREE_TYPE (expr)) == FUNCTION_TYPE) expr = default_conversion (expr); if (warn_sequence_point) verify_sequence_points (expr); if (TREE_TYPE (expr) != error_mark_node && !COMPLETE_OR_VOID_TYPE_P (TREE_TYPE (expr)) && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE) error ("expression statement has incomplete type"); /* If we're not processing a statement expression, warn about unused values. Warnings for statement expressions will be emitted later, once we figure out which is the result. */ if (!STATEMENT_LIST_STMT_EXPR (cur_stmt_list) && (extra_warnings || warn_unused_value)) emit_side_effect_warnings (expr); /* If the expression is not of a type to which we cannot assign a line number, wrap the thing in a no-op NOP_EXPR. */ if (DECL_P (expr) || CONSTANT_CLASS_P (expr)) expr = build1 (NOP_EXPR, TREE_TYPE (expr), expr); if (EXPR_P (expr)) SET_EXPR_LOCATION (expr, input_location); return expr; } /* Emit an expression as a statement. */ tree c_finish_expr_stmt (tree expr) { if (expr) return add_stmt (c_process_expr_stmt (expr)); else return NULL; } /* Do the opposite and emit a statement as an expression. To begin, create a new binding level and return it. */ tree c_begin_stmt_expr (void) { tree ret; /* We must force a BLOCK for this level so that, if it is not expanded later, there is a way to turn off the entire subtree of blocks that are contained in it. */ keep_next_level (); ret = c_begin_compound_stmt (true); /* Mark the current statement list as belonging to a statement list. */ STATEMENT_LIST_STMT_EXPR (ret) = 1; return ret; } tree c_finish_stmt_expr (tree body) { tree last, type, tmp, val; tree *last_p; body = c_end_compound_stmt (body, true); /* Locate the last statement in BODY. See c_end_compound_stmt about always returning a BIND_EXPR. */ last_p = &BIND_EXPR_BODY (body); last = BIND_EXPR_BODY (body); continue_searching: if (TREE_CODE (last) == STATEMENT_LIST) { tree_stmt_iterator i; /* This can happen with degenerate cases like ({ }). No value. */ if (!TREE_SIDE_EFFECTS (last)) return body; /* If we're supposed to generate side effects warnings, process all of the statements except the last. */ if (extra_warnings || warn_unused_value) { for (i = tsi_start (last); !tsi_one_before_end_p (i); tsi_next (&i)) emit_side_effect_warnings (tsi_stmt (i)); } else i = tsi_last (last); last_p = tsi_stmt_ptr (i); last = *last_p; } /* If the end of the list is exception related, then the list was split by a call to push_cleanup. Continue searching. */ if (TREE_CODE (last) == TRY_FINALLY_EXPR || TREE_CODE (last) == TRY_CATCH_EXPR) { last_p = &TREE_OPERAND (last, 0); last = *last_p; goto continue_searching; } /* In the case that the BIND_EXPR is not necessary, return the expression out from inside it. */ if (last == error_mark_node || (last == BIND_EXPR_BODY (body) && BIND_EXPR_VARS (body) == NULL)) return last; /* Extract the type of said expression. */ type = TREE_TYPE (last); /* If we're not returning a value at all, then the BIND_EXPR that we already have is a fine expression to return. */ if (!type || VOID_TYPE_P (type)) return body; /* Now that we've located the expression containing the value, it seems silly to make voidify_wrapper_expr repeat the process. Create a temporary of the appropriate type and stick it in a TARGET_EXPR. */ tmp = create_tmp_var_raw (type, NULL); /* Unwrap a no-op NOP_EXPR as added by c_finish_expr_stmt. This avoids tree_expr_nonnegative_p giving up immediately. */ val = last; if (TREE_CODE (val) == NOP_EXPR && TREE_TYPE (val) == TREE_TYPE (TREE_OPERAND (val, 0))) val = TREE_OPERAND (val, 0); *last_p = build2 (MODIFY_EXPR, void_type_node, tmp, val); SET_EXPR_LOCUS (*last_p, EXPR_LOCUS (last)); return build4 (TARGET_EXPR, type, tmp, body, NULL_TREE, NULL_TREE); } /* Begin and end compound statements. This is as simple as pushing and popping new statement lists from the tree. */ tree c_begin_compound_stmt (bool do_scope) { tree stmt = push_stmt_list (); if (do_scope) push_scope (); return stmt; } tree c_end_compound_stmt (tree stmt, bool do_scope) { tree block = NULL; if (do_scope) { if (c_dialect_objc ()) objc_clear_super_receiver (); block = pop_scope (); } stmt = pop_stmt_list (stmt); stmt = c_build_bind_expr (block, stmt); /* If this compound statement is nested immediately inside a statement expression, then force a BIND_EXPR to be created. Otherwise we'll do the wrong thing for ({ { 1; } }) or ({ 1; { } }). In particular, STATEMENT_LISTs merge, and thus we can lose track of what statement was really last. */ if (cur_stmt_list && STATEMENT_LIST_STMT_EXPR (cur_stmt_list) && TREE_CODE (stmt) != BIND_EXPR) { stmt = build3 (BIND_EXPR, void_type_node, NULL, stmt, NULL); TREE_SIDE_EFFECTS (stmt) = 1; } return stmt; } /* Queue a cleanup. CLEANUP is an expression/statement to be executed when the current scope is exited. EH_ONLY is true when this is not meant to apply to normal control flow transfer. */ void push_cleanup (tree ARG_UNUSED (decl), tree cleanup, bool eh_only) { enum tree_code code; tree stmt, list; bool stmt_expr; code = eh_only ? TRY_CATCH_EXPR : TRY_FINALLY_EXPR; stmt = build_stmt (code, NULL, cleanup); add_stmt (stmt); stmt_expr = STATEMENT_LIST_STMT_EXPR (cur_stmt_list); list = push_stmt_list (); TREE_OPERAND (stmt, 0) = list; STATEMENT_LIST_STMT_EXPR (list) = stmt_expr; } /* Build a binary-operation expression without default conversions. CODE is the kind of expression to build. This function differs from `build' in several ways: the data type of the result is computed and recorded in it, warnings are generated if arg data types are invalid, special handling for addition and subtraction of pointers is known, and some optimization is done (operations on narrow ints are done in the narrower type when that gives the same result). Constant folding is also done before the result is returned. Note that the operands will never have enumeral types, or function or array types, because either they will have the default conversions performed or they have both just been converted to some other type in which the arithmetic is to be done. */ tree build_binary_op (enum tree_code code, tree orig_op0, tree orig_op1, int convert_p) { tree type0, type1; enum tree_code code0, code1; tree op0, op1; /* Expression code to give to the expression when it is built. Normally this is CODE, which is what the caller asked for, but in some special cases we change it. */ enum tree_code resultcode = code; /* Data type in which the computation is to be performed. In the simplest cases this is the common type of the arguments. */ tree result_type = NULL; /* Nonzero means operands have already been type-converted in whatever way is necessary. Zero means they need to be converted to RESULT_TYPE. */ int converted = 0; /* Nonzero means create the expression with this type, rather than RESULT_TYPE. */ tree build_type = 0; /* Nonzero means after finally constructing the expression convert it to this type. */ tree final_type = 0; /* Nonzero if this is an operation like MIN or MAX which can safely be computed in short if both args are promoted shorts. Also implies COMMON. -1 indicates a bitwise operation; this makes a difference in the exact conditions for when it is safe to do the operation in a narrower mode. */ int shorten = 0; /* Nonzero if this is a comparison operation; if both args are promoted shorts, compare the original shorts. Also implies COMMON. */ int short_compare = 0; /* Nonzero if this is a right-shift operation, which can be computed on the original short and then promoted if the operand is a promoted short. */ int short_shift = 0; /* Nonzero means set RESULT_TYPE to the common type of the args. */ int common = 0; if (convert_p) { op0 = default_conversion (orig_op0); op1 = default_conversion (orig_op1); } else { op0 = orig_op0; op1 = orig_op1; } type0 = TREE_TYPE (op0); type1 = TREE_TYPE (op1); /* The expression codes of the data types of the arguments tell us whether the arguments are integers, floating, pointers, etc. */ code0 = TREE_CODE (type0); code1 = TREE_CODE (type1); /* Strip NON_LVALUE_EXPRs, etc., since we aren't using as an lvalue. */ STRIP_TYPE_NOPS (op0); STRIP_TYPE_NOPS (op1); /* If an error was already reported for one of the arguments, avoid reporting another error. */ if (code0 == ERROR_MARK || code1 == ERROR_MARK) return error_mark_node; switch (code) { case PLUS_EXPR: /* Handle the pointer + int case. */ if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) return pointer_int_sum (PLUS_EXPR, op0, op1); else if (code1 == POINTER_TYPE && code0 == INTEGER_TYPE) return pointer_int_sum (PLUS_EXPR, op1, op0); else common = 1; break; case MINUS_EXPR: /* Subtraction of two similar pointers. We must subtract them as integers, then divide by object size. */ if (code0 == POINTER_TYPE && code1 == POINTER_TYPE && comp_target_types (type0, type1, 1)) return pointer_diff (op0, op1); /* Handle pointer minus int. Just like pointer plus int. */ else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) return pointer_int_sum (MINUS_EXPR, op0, op1); else common = 1; break; case MULT_EXPR: common = 1; break; case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR: case ROUND_DIV_EXPR: case EXACT_DIV_EXPR: /* Floating point division by zero is a legitimate way to obtain infinities and NaNs. */ if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) warning ("division by zero"); if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) && (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) { if (code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) code0 = TREE_CODE (TREE_TYPE (TREE_TYPE (op0))); if (code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE) code1 = TREE_CODE (TREE_TYPE (TREE_TYPE (op1))); if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE)) resultcode = RDIV_EXPR; else /* Although it would be tempting to shorten always here, that loses on some targets, since the modulo instruction is undefined if the quotient can't be represented in the computation mode. We shorten only if unsigned or if dividing by something we know != -1. */ shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) || (TREE_CODE (op1) == INTEGER_CST && !integer_all_onesp (op1))); common = 1; } break; case BIT_AND_EXPR: case BIT_IOR_EXPR: case BIT_XOR_EXPR: if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) shorten = -1; else if (code0 == VECTOR_TYPE && code1 == VECTOR_TYPE) common = 1; break; case TRUNC_MOD_EXPR: case FLOOR_MOD_EXPR: if (warn_div_by_zero && skip_evaluation == 0 && integer_zerop (op1)) warning ("division by zero"); if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) { /* Although it would be tempting to shorten always here, that loses on some targets, since the modulo instruction is undefined if the quotient can't be represented in the computation mode. We shorten only if unsigned or if dividing by something we know != -1. */ shorten = (TYPE_UNSIGNED (TREE_TYPE (orig_op0)) || (TREE_CODE (op1) == INTEGER_CST && !integer_all_onesp (op1))); common = 1; } break; case TRUTH_ANDIF_EXPR: case TRUTH_ORIF_EXPR: case TRUTH_AND_EXPR: case TRUTH_OR_EXPR: case TRUTH_XOR_EXPR: if ((code0 == INTEGER_TYPE || code0 == POINTER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) && (code1 == INTEGER_TYPE || code1 == POINTER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) { /* Result of these operations is always an int, but that does not mean the operands should be converted to ints! */ result_type = integer_type_node; op0 = c_common_truthvalue_conversion (op0); op1 = c_common_truthvalue_conversion (op1); converted = 1; } break; /* Shift operations: result has same type as first operand; always convert second operand to int. Also set SHORT_SHIFT if shifting rightward. */ case RSHIFT_EXPR: if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) { if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) { if (tree_int_cst_sgn (op1) < 0) warning ("right shift count is negative"); else { if (!integer_zerop (op1)) short_shift = 1; if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) warning ("right shift count >= width of type"); } } /* Use the type of the value to be shifted. */ result_type = type0; /* Convert the shift-count to an integer, regardless of size of value being shifted. */ if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) op1 = convert (integer_type_node, op1); /* Avoid converting op1 to result_type later. */ converted = 1; } break; case LSHIFT_EXPR: if (code0 == INTEGER_TYPE && code1 == INTEGER_TYPE) { if (TREE_CODE (op1) == INTEGER_CST && skip_evaluation == 0) { if (tree_int_cst_sgn (op1) < 0) warning ("left shift count is negative"); else if (compare_tree_int (op1, TYPE_PRECISION (type0)) >= 0) warning ("left shift count >= width of type"); } /* Use the type of the value to be shifted. */ result_type = type0; /* Convert the shift-count to an integer, regardless of size of value being shifted. */ if (TYPE_MAIN_VARIANT (TREE_TYPE (op1)) != integer_type_node) op1 = convert (integer_type_node, op1); /* Avoid converting op1 to result_type later. */ converted = 1; } break; case EQ_EXPR: case NE_EXPR: if (warn_float_equal && (code0 == REAL_TYPE || code1 == REAL_TYPE)) warning ("comparing floating point with == or != is unsafe"); /* Result of comparison is always int, but don't convert the args to int! */ build_type = integer_type_node; if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE) && (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE)) short_compare = 1; else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) { tree tt0 = TREE_TYPE (type0); tree tt1 = TREE_TYPE (type1); /* Anything compares with void *. void * compares with anything. Otherwise, the targets must be compatible and both must be object or both incomplete. */ if (comp_target_types (type0, type1, 1)) result_type = common_pointer_type (type0, type1); else if (VOID_TYPE_P (tt0)) { /* op0 != orig_op0 detects the case of something whose value is 0 but which isn't a valid null ptr const. */ if (pedantic && (!integer_zerop (op0) || op0 != orig_op0) && TREE_CODE (tt1) == FUNCTION_TYPE) pedwarn ("ISO C forbids comparison of %" " with function pointer"); } else if (VOID_TYPE_P (tt1)) { if (pedantic && (!integer_zerop (op1) || op1 != orig_op1) && TREE_CODE (tt0) == FUNCTION_TYPE) pedwarn ("ISO C forbids comparison of %" " with function pointer"); } else pedwarn ("comparison of distinct pointer types lacks a cast"); if (result_type == NULL_TREE) result_type = ptr_type_node; } else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1)) result_type = type0; else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST && integer_zerop (op0)) result_type = type1; else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) { result_type = type0; pedwarn ("comparison between pointer and integer"); } else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) { result_type = type1; pedwarn ("comparison between pointer and integer"); } break; case LE_EXPR: case GE_EXPR: case LT_EXPR: case GT_EXPR: build_type = integer_type_node; if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE) && (code1 == INTEGER_TYPE || code1 == REAL_TYPE)) short_compare = 1; else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE) { if (comp_target_types (type0, type1, 1)) { result_type = common_pointer_type (type0, type1); if (!COMPLETE_TYPE_P (TREE_TYPE (type0)) != !COMPLETE_TYPE_P (TREE_TYPE (type1))) pedwarn ("comparison of complete and incomplete pointers"); else if (pedantic && TREE_CODE (TREE_TYPE (type0)) == FUNCTION_TYPE) pedwarn ("ISO C forbids ordered comparisons of pointers to functions"); } else { result_type = ptr_type_node; pedwarn ("comparison of distinct pointer types lacks a cast"); } } else if (code0 == POINTER_TYPE && TREE_CODE (op1) == INTEGER_CST && integer_zerop (op1)) { result_type = type0; if (pedantic || extra_warnings) pedwarn ("ordered comparison of pointer with integer zero"); } else if (code1 == POINTER_TYPE && TREE_CODE (op0) == INTEGER_CST && integer_zerop (op0)) { result_type = type1; if (pedantic) pedwarn ("ordered comparison of pointer with integer zero"); } else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE) { result_type = type0; pedwarn ("comparison between pointer and integer"); } else if (code0 == INTEGER_TYPE && code1 == POINTER_TYPE) { result_type = type1; pedwarn ("comparison between pointer and integer"); } break; default: gcc_unreachable (); } if (code0 == ERROR_MARK || code1 == ERROR_MARK) return error_mark_node; if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE) && (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE)) { int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE); if (shorten || common || short_compare) result_type = c_common_type (type0, type1); /* For certain operations (which identify themselves by shorten != 0) if both args were extended from the same smaller type, do the arithmetic in that type and then extend. shorten !=0 and !=1 indicates a bitwise operation. For them, this optimization is safe only if both args are zero-extended or both are sign-extended. Otherwise, we might change the result. Eg, (short)-1 | (unsigned short)-1 is (int)-1 but calculated in (unsigned short) it would be (unsigned short)-1. */ if (shorten && none_complex) { int unsigned0, unsigned1; tree arg0 = get_narrower (op0, &unsigned0); tree arg1 = get_narrower (op1, &unsigned1); /* UNS is 1 if the operation to be done is an unsigned one. */ int uns = TYPE_UNSIGNED (result_type); tree type; final_type = result_type; /* Handle the case that OP0 (or OP1) does not *contain* a conversion but it *requires* conversion to FINAL_TYPE. */ if ((TYPE_PRECISION (TREE_TYPE (op0)) == TYPE_PRECISION (TREE_TYPE (arg0))) && TREE_TYPE (op0) != final_type) unsigned0 = TYPE_UNSIGNED (TREE_TYPE (op0)); if ((TYPE_PRECISION (TREE_TYPE (op1)) == TYPE_PRECISION (TREE_TYPE (arg1))) && TREE_TYPE (op1) != final_type) unsigned1 = TYPE_UNSIGNED (TREE_TYPE (op1)); /* Now UNSIGNED0 is 1 if ARG0 zero-extends to FINAL_TYPE. */ /* For bitwise operations, signedness of nominal type does not matter. Consider only how operands were extended. */ if (shorten == -1) uns = unsigned0; /* Note that in all three cases below we refrain from optimizing an unsigned operation on sign-extended args. That would not be valid. */ /* Both args variable: if both extended in same way from same width, do it in that width. Do it unsigned if args were zero-extended. */ if ((TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)) && (TYPE_PRECISION (TREE_TYPE (arg1)) == TYPE_PRECISION (TREE_TYPE (arg0))) && unsigned0 == unsigned1 && (unsigned0 || !uns)) result_type = c_common_signed_or_unsigned_type (unsigned0, c_common_type (TREE_TYPE (arg0), TREE_TYPE (arg1))); else if (TREE_CODE (arg0) == INTEGER_CST && (unsigned1 || !uns) && (TYPE_PRECISION (TREE_TYPE (arg1)) < TYPE_PRECISION (result_type)) && (type = c_common_signed_or_unsigned_type (unsigned1, TREE_TYPE (arg1)), int_fits_type_p (arg0, type))) result_type = type; else if (TREE_CODE (arg1) == INTEGER_CST && (unsigned0 || !uns) && (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type)) && (type = c_common_signed_or_unsigned_type (unsigned0, TREE_TYPE (arg0)), int_fits_type_p (arg1, type))) result_type = type; } /* Shifts can be shortened if shifting right. */ if (short_shift) { int unsigned_arg; tree arg0 = get_narrower (op0, &unsigned_arg); final_type = result_type; if (arg0 == op0 && final_type == TREE_TYPE (op0)) unsigned_arg = TYPE_UNSIGNED (TREE_TYPE (op0)); if (TYPE_PRECISION (TREE_TYPE (arg0)) < TYPE_PRECISION (result_type) /* We can shorten only if the shift count is less than the number of bits in the smaller type size. */ && compare_tree_int (op1, TYPE_PRECISION (TREE_TYPE (arg0))) < 0 /* We cannot drop an unsigned shift after sign-extension. */ && (!TYPE_UNSIGNED (final_type) || unsigned_arg)) { /* Do an unsigned shift if the operand was zero-extended. */ result_type = c_common_signed_or_unsigned_type (unsigned_arg, TREE_TYPE (arg0)); /* Convert value-to-be-shifted to that type. */ if (TREE_TYPE (op0) != result_type) op0 = convert (result_type, op0); converted = 1; } } /* Comparison operations are shortened too but differently. They identify themselves by setting short_compare = 1. */ if (short_compare) { /* Don't write &op0, etc., because that would prevent op0 from being kept in a register. Instead, make copies of the our local variables and pass the copies by reference, then copy them back afterward. */ tree xop0 = op0, xop1 = op1, xresult_type = result_type; enum tree_code xresultcode = resultcode; tree val = shorten_compare (&xop0, &xop1, &xresult_type, &xresultcode); if (val != 0) return val; op0 = xop0, op1 = xop1; converted = 1; resultcode = xresultcode; if (warn_sign_compare && skip_evaluation == 0) { int op0_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op0)); int op1_signed = !TYPE_UNSIGNED (TREE_TYPE (orig_op1)); int unsignedp0, unsignedp1; tree primop0 = get_narrower (op0, &unsignedp0); tree primop1 = get_narrower (op1, &unsignedp1); xop0 = orig_op0; xop1 = orig_op1; STRIP_TYPE_NOPS (xop0); STRIP_TYPE_NOPS (xop1); /* Give warnings for comparisons between signed and unsigned quantities that may fail. Do the checking based on the original operand trees, so that casts will be considered, but default promotions won't be. Do not warn if the comparison is being done in a signed type, since the signed type will only be chosen if it can represent all the values of the unsigned type. */ if (!TYPE_UNSIGNED (result_type)) /* OK */; /* Do not warn if both operands are the same signedness. */ else if (op0_signed == op1_signed) /* OK */; else { tree sop, uop; if (op0_signed) sop = xop0, uop = xop1; else sop = xop1, uop = xop0; /* Do not warn if the signed quantity is an unsuffixed integer literal (or some static constant expression involving such literals or a conditional expression involving such literals) and it is non-negative. */ if (tree_expr_nonnegative_p (sop)) /* OK */; /* Do not warn if the comparison is an equality operation, the unsigned quantity is an integral constant, and it would fit in the result if the result were signed. */ else if (TREE_CODE (uop) == INTEGER_CST && (resultcode == EQ_EXPR || resultcode == NE_EXPR) && int_fits_type_p (uop, c_common_signed_type (result_type))) /* OK */; /* Do not warn if the unsigned quantity is an enumeration constant and its maximum value would fit in the result if the result were signed. */ else if (TREE_CODE (uop) == INTEGER_CST && TREE_CODE (TREE_TYPE (uop)) == ENUMERAL_TYPE && int_fits_type_p (TYPE_MAX_VALUE (TREE_TYPE (uop)), c_common_signed_type (result_type))) /* OK */; else warning ("comparison between signed and unsigned"); } /* Warn if two unsigned values are being compared in a size larger than their original size, and one (and only one) is the result of a `~' operator. This comparison will always fail. Also warn if one operand is a constant, and the constant does not have all bits set that are set in the ~ operand when it is extended. */ if ((TREE_CODE (primop0) == BIT_NOT_EXPR) != (TREE_CODE (primop1) == BIT_NOT_EXPR)) { if (TREE_CODE (primop0) == BIT_NOT_EXPR) primop0 = get_narrower (TREE_OPERAND (primop0, 0), &unsignedp0); else primop1 = get_narrower (TREE_OPERAND (primop1, 0), &unsignedp1); if (host_integerp (primop0, 0) || host_integerp (primop1, 0)) { tree primop; HOST_WIDE_INT constant, mask; int unsignedp, bits; if (host_integerp (primop0, 0)) { primop = primop1; unsignedp = unsignedp1; constant = tree_low_cst (primop0, 0); } else { primop = primop0; unsignedp = unsignedp0; constant = tree_low_cst (primop1, 0); } bits = TYPE_PRECISION (TREE_TYPE (primop)); if (bits < TYPE_PRECISION (result_type) && bits < HOST_BITS_PER_WIDE_INT && unsignedp) { mask = (~(HOST_WIDE_INT) 0) << bits; if ((mask & constant) != mask) warning ("comparison of promoted ~unsigned with constant"); } } else if (unsignedp0 && unsignedp1 && (TYPE_PRECISION (TREE_TYPE (primop0)) < TYPE_PRECISION (result_type)) && (TYPE_PRECISION (TREE_TYPE (primop1)) < TYPE_PRECISION (result_type))) warning ("comparison of promoted ~unsigned with unsigned"); } } } } /* At this point, RESULT_TYPE must be nonzero to avoid an error message. If CONVERTED is zero, both args will be converted to type RESULT_TYPE. Then the expression will be built. It will be given type FINAL_TYPE if that is nonzero; otherwise, it will be given type RESULT_TYPE. */ if (!result_type) { binary_op_error (code); return error_mark_node; } if (!converted) { if (TREE_TYPE (op0) != result_type) op0 = convert (result_type, op0); if (TREE_TYPE (op1) != result_type) op1 = convert (result_type, op1); /* This can happen if one operand has a vector type, and the other has a different type. */ if (TREE_CODE (op0) == ERROR_MARK || TREE_CODE (op1) == ERROR_MARK) return error_mark_node; } if (build_type == NULL_TREE) build_type = result_type; { tree result = build2 (resultcode, build_type, op0, op1); /* Treat expressions in initializers specially as they can't trap. */ result = require_constant_value ? fold_initializer (result) : fold (result); if (final_type != 0) result = convert (final_type, result); return result; } } /* Convert EXPR to be a truth-value, validating its type for this purpose. Passes EXPR to default_function_array_conversion. */ tree c_objc_common_truthvalue_conversion (tree expr) { expr = default_function_array_conversion (expr); switch (TREE_CODE (TREE_TYPE (expr))) { case ARRAY_TYPE: error ("used array that cannot be converted to pointer where scalar is required"); return error_mark_node; case RECORD_TYPE: error ("used struct type value where scalar is required"); return error_mark_node; case UNION_TYPE: error ("used union type value where scalar is required"); return error_mark_node; default: break; } /* ??? Should we also give an error for void and vectors rather than leaving those to give errors later? */ return c_common_truthvalue_conversion (expr); }