/* 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.  */

struct lang_identifier
{
  struct tree_identifier ignore;
  tree global_value, local_value, label_value, implicit_decl;
  tree error_locus;
};

/* Macros for access to language-specific slots in an identifier.  */

#define IDENTIFIER_GLOBAL_VALUE(NODE)	\
  (((struct lang_identifier *)(NODE))->global_value)
#define IDENTIFIER_LOCAL_VALUE(NODE)	\
  (((struct lang_identifier *)(NODE))->local_value)
#define IDENTIFIER_LABEL_VALUE(NODE)	\
  (((struct lang_identifier *)(NODE))->label_value)
#define IDENTIFIER_IMPLICIT_DECL(NODE)	\
  (((struct lang_identifier *)(NODE))->implicit_decl)
#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))

/* 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)

/* 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 ();

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 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;
