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- /* Definitions for C parsing and type checking.
- Copyright (C) 1987 Free Software Foundation, Inc.
-
- This file is part of GNU CC.
-
- GNU CC 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.
-
- GNU CC 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 GNU CC; see the file COPYING. If not, write to
- the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
-
- /* Language-dependent contents of an identifier. */
-
- /* The limbo_value is used for block level extern declarations, which need
- to be type checked against subsequent extern declarations. They can't
- be referenced after they fall out of scope, so they can't be global. */
-
- struct lang_identifier
- {
- struct tree_identifier ignore;
- tree global_value, local_value, label_value, implicit_decl;
- tree error_locus, limbo_value;
- };
-
- /* Macros for access to language-specific slots in an identifier. */
- /* Each of these slots contains a DECL node or null. */
-
- /* This represents the value which the identifier has in the
- file-scope namespace. */
- #define IDENTIFIER_GLOBAL_VALUE(NODE) \
- (((struct lang_identifier *)(NODE))->global_value)
- /* This represents the value which the identifier has in the current
- scope. */
- #define IDENTIFIER_LOCAL_VALUE(NODE) \
- (((struct lang_identifier *)(NODE))->local_value)
- /* This represents the value which the identifier has as a label in
- the current label scope. */
- #define IDENTIFIER_LABEL_VALUE(NODE) \
- (((struct lang_identifier *)(NODE))->label_value)
- /* This records the extern decl of this identifier, if it has had one
- at any point in this compilation. */
- #define IDENTIFIER_LIMBO_VALUE(NODE) \
- (((struct lang_identifier *)(NODE))->limbo_value)
- /* This records the implicit function decl of this identifier, if it
- has had one at any point in this compilation. */
- #define IDENTIFIER_IMPLICIT_DECL(NODE) \
- (((struct lang_identifier *)(NODE))->implicit_decl)
- /* This is the last function in which we printed an "undefined variable"
- message for this identifier. Value is a FUNCTION_DECL or null. */
- #define IDENTIFIER_ERROR_LOCUS(NODE) \
- (((struct lang_identifier *)(NODE))->error_locus)
-
- /* In identifiers, C uses the following fields in a special way:
- TREE_PUBLIC to record that there was a previous local extern decl.
- TREE_USED to record that such a decl was used.
- TREE_ADDRESSABLE to record that the address of such a decl was used. */
-
- /* Nonzero means reject anything that ANSI standard C forbids. */
- extern int pedantic;
-
- /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is read-only. */
- #define C_TYPE_FIELDS_READONLY(type) TREE_LANG_FLAG_1 (type)
-
- /* In a RECORD_TYPE or UNION_TYPE, nonzero if any component is volatile. */
- #define C_TYPE_FIELDS_VOLATILE(type) TREE_LANG_FLAG_2 (type)
-
- /* In a RECORD_TYPE or UNION_TYPE or ENUMERAL_TYPE
- nonzero if the definition of the type has already started. */
- #define C_TYPE_BEING_DEFINED(type) TYPE_LANG_FLAG_0 (type)
-
- /* In a RECORD_TYPE, a sorted array of the fields of the type. */
- struct lang_type
- {
- int len;
- tree elts[1];
- };
-
- /* Mark which labels are explicitly declared.
- These may be shadowed, and may be referenced from nested functions. */
- #define C_DECLARED_LABEL_FLAG(label) TREE_LANG_FLAG_1 (label)
-
- /* Record whether a type or decl was written with nonconstant size.
- Note that TYPE_SIZE may have simplified to a constant. */
- #define C_TYPE_VARIABLE_SIZE(type) TYPE_LANG_FLAG_1 (type)
- #define C_DECL_VARIABLE_SIZE(type) DECL_LANG_FLAG_0 (type)
-
- /* Record in each node resulting from a binary operator
- what operator was specified for it. */
- #define C_EXP_ORIGINAL_CODE(exp) ((enum tree_code) TREE_COMPLEXITY (exp))
-
- #if 0 /* Not used. */
- /* Record whether a decl for a function or function pointer has
- already been mentioned (in a warning) because it was called
- but didn't have a prototype. */
- #define C_MISSING_PROTOTYPE_WARNED(decl) DECL_LANG_FLAG_2(decl)
- #endif
-
- /* Store a value in that field. */
- #define C_SET_EXP_ORIGINAL_CODE(exp, code) \
- (TREE_COMPLEXITY (exp) = (int)(code))
-
- /* Record whether a typedef for type `int' was actually `signed int'. */
- #define C_TYPEDEF_EXPLICITLY_SIGNED(exp) DECL_LANG_FLAG_1 ((exp))
-
- /* Nonzero for a declaration of a built in function if there has been no
- occasion that would declare the function in ordinary C.
- Using the function draws a pedantic warning in this case. */
- #define C_DECL_ANTICIPATED(exp) DECL_LANG_FLAG_3 ((exp))
-
- /* For FUNCTION_TYPE, a hidden list of types of arguments. The same as
- TYPE_ARG_TYPES for functions with prototypes, but created for functions
- without prototypes. */
- #define TYPE_ACTUAL_ARG_TYPES(NODE) TYPE_NONCOPIED_PARTS (NODE)
-
- /* Nonzero if the type T promotes to itself.
- ANSI C states explicitly the list of types that promote;
- in particular, short promotes to int even if they have the same width. */
- #define C_PROMOTING_INTEGER_TYPE_P(t) \
- (TREE_CODE ((t)) == INTEGER_TYPE \
- && (TYPE_MAIN_VARIANT (t) == char_type_node \
- || TYPE_MAIN_VARIANT (t) == signed_char_type_node \
- || TYPE_MAIN_VARIANT (t) == unsigned_char_type_node \
- || TYPE_MAIN_VARIANT (t) == short_integer_type_node \
- || TYPE_MAIN_VARIANT (t) == short_unsigned_type_node))
-
- /* in c-typecheck.c */
- extern tree build_component_ref (), build_conditional_expr (), build_compound_expr ();
- extern tree build_unary_op (), build_binary_op (), build_function_call ();
- extern tree parser_build_binary_op ();
- extern tree build_indirect_ref (), build_array_ref (), build_c_cast ();
- extern tree build_modify_expr ();
- extern tree c_sizeof (), c_alignof (), c_alignof_expr ();
- extern void store_init_value ();
- extern tree digest_init ();
- extern tree c_expand_start_case ();
- extern tree default_conversion ();
-
- /* Given two integer or real types, return the type for their sum.
- Given two compatible ANSI C types, returns the merged type. */
-
- extern tree common_type ();
-
- /* in c-decl.c */
- extern tree build_label ();
-
- extern int start_function ();
- extern void finish_function ();
- extern void store_parm_decls ();
- extern tree get_parm_info ();
- extern tree combine_parm_decls ();
-
- extern void pushlevel ();
- extern tree poplevel ();
-
- extern tree groktypename (), lookup_name ();
-
- extern tree lookup_label (), define_label (), shadow_label ();
-
- extern tree implicitly_declare (), getdecls (), gettags ();
-
- extern tree start_decl ();
- extern void finish_decl ();
-
- extern tree start_struct (), finish_struct (), xref_tag ();
- extern tree grokfield ();
-
- extern tree start_enum (), finish_enum ();
- extern tree build_enumerator ();
-
- extern tree make_index_type ();
-
- /* Add qualifiers to a type, in the fashion for C. */
- extern tree c_build_type_variant ();
-
- /* Declare a predefined function. Return the declaration. */
- extern tree builtin_function ();
-
- /* Functions in c-common.c: */
-
- /* Concatenate a list of STRING_CST nodes into one STRING_CST. */
- extern tree combine_strings ();
-
- /* Validate the expression after `case' and apply default promotions. */
- extern tree check_case_value ();
-
- /* Print an error message for invalid operands to arith operation CODE.
- NOP_EXPR is used as a special case (see truthvalue_conversion). */
-
- extern void binary_op_error ();
-
- /* Subroutine of build_binary_op, used for comparison operations.
- See if the operands have both been converted from subword integer types
- and, if so, perhaps change them both back to their original type. */
-
- extern tree shorten_compare ();
-
- /* Read the rest of the current #-directive line. */
- extern char *get_directive_line ();
-
- /* Prepare expr to be an argument of a TRUTH_NOT_EXPR,
- or validate its data type for an `if' or `while' statement or ?..: exp. */
- extern tree truthvalue_conversion ();
-
- extern int maybe_objc_comptypes ();
- extern tree maybe_building_objc_message_expr ();
-
- /* Standard named or nameless data types of the C compiler. */
-
- extern tree short_integer_type_node, integer_type_node;
- extern tree long_integer_type_node, long_long_integer_type_node;
- extern tree short_unsigned_type_node, unsigned_type_node;
- extern tree long_unsigned_type_node, long_long_unsigned_type_node;
- extern tree ptrdiff_type_node;
- extern tree unsigned_char_type_node, signed_char_type_node, char_type_node;
- extern tree wchar_type_node, signed_wchar_type_node, unsigned_wchar_type_node;
- extern tree float_type_node, double_type_node, long_double_type_node;
- extern tree intQI_type_node, unsigned_intQI_type_node;
- extern tree intHI_type_node, unsigned_intHI_type_node;
- extern tree intSI_type_node, unsigned_intSI_type_node;
- extern tree intDI_type_node, unsigned_intDI_type_node;
- extern tree void_type_node, ptr_type_node, const_ptr_type_node;
- extern tree string_type_node, const_string_type_node;
- extern tree char_array_type_node, int_array_type_node, wchar_array_type_node;
- extern tree default_function_type;
- extern tree double_ftype_double, double_ftype_double_double;
- extern tree int_ftype_int, long_ftype_long;
- extern tree void_ftype_ptr_ptr_int, int_ftype_ptr_ptr_int;
- extern tree void_ftype_ptr_int_int, string_ftype_ptr_ptr;
- extern tree int_ftype_string_string, int_ftype_cptr_cptr_sizet;
-
- /* Set to 0 at beginning of a function definition, set to 1 if
- a return statement that specifies a return value is seen. */
-
- extern int current_function_returns_value;
-
- /* Set to 0 at beginning of a function definition, set to 1 if
- a return statement with no argument is seen. */
-
- extern int current_function_returns_null;
-
- /* Nonzero means `$' can be in an identifier. */
-
- extern int dollars_in_ident;
-
- /* Nonzero means allow type mismatches in conditional expressions;
- just make their values `void'. */
-
- extern int flag_cond_mismatch;
-
- /* Nonzero means don't recognize the keyword `asm'. */
-
- extern int flag_no_asm;
-
- /* Nonzero means ignore `#ident' directives. */
-
- extern int flag_no_ident;
-
- /* Nonzero means warn about implicit declarations. */
-
- extern int warn_implicit;
-
- /* Nonzero means give string constants the type `const char *'
- to get extra warnings from them. These warnings will be too numerous
- to be useful, except in thoroughly ANSIfied programs. */
-
- extern int warn_write_strings;
-
- /* Nonzero means warn about sizeof (function) or addition/subtraction
- of function pointers. */
-
- extern int warn_pointer_arith;
-
- /* Nonzero means warn for all old-style non-prototype function decls. */
-
- extern int warn_strict_prototypes;
-
- /* Nonzero means warn about multiple (redundant) decls for the same single
- variable or function. */
-
- extern int warn_redundant_decls;
-
- /* Nonzero means warn about extern declarations of objects not at
- file-scope level and about *all* declarations of functions (whether
- extern or static) not at file-scope level. Note that we exclude
- implicit function declarations. To get warnings about those, use
- -Wimplicit. */
-
- extern int warn_nested_externs;
-
- /* Nonzero means warn about pointer casts that can drop a type qualifier
- from the pointer target type. */
-
- extern int warn_cast_qual;
-
- /* Warn about traditional constructs whose meanings changed in ANSI C. */
-
- extern int warn_traditional;
-
- /* Warn about *printf or *scanf format/argument anomalies. */
-
- extern int warn_format;
-
- /* Warn about a subscript that has type char. */
-
- extern int warn_char_subscripts;
-
- /* Warn if a type conversion is done that might have confusing results. */
-
- extern int warn_conversion;
-
- /* Nonzero means do some things the same way PCC does. */
-
- extern int flag_traditional;
-
- /* Nonzero means warn about suggesting putting in ()'s. */
-
- extern int warn_parentheses;
-
- /* Nonzero means this is a function to call to perform comptypes
- on two record types. */
-
- extern int (*comptypes_record_hook) ();
-
- /* Nonzero means we are reading code that came from a system header file. */
-
- extern int system_header_p;
-