1/* Declarations for the parser for C and Objective-C.
2 Copyright (C) 1987-2023 Free Software Foundation, Inc.
3
4 Parser actions based on the old Bison parser; structure somewhat
5 influenced by and fragments based on the C++ parser.
6
7This file is part of GCC.
8
9GCC is free software; you can redistribute it and/or modify it under
10the terms of the GNU General Public License as published by the Free
11Software Foundation; either version 3, or (at your option) any later
12version.
13
14GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15WARRANTY; without even the implied warranty of MERCHANTABILITY or
16FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17for more details.
18
19You should have received a copy of the GNU General Public License
20along with GCC; see the file COPYING3. If not see
21<http://www.gnu.org/licenses/>. */
22
23#ifndef GCC_C_PARSER_H
24#define GCC_C_PARSER_H
25
26/* The C lexer intermediates between the lexer in cpplib and c-lex.cc
27 and the C parser. Unlike the C++ lexer, the parser structure
28 stores the lexer information instead of using a separate structure.
29 Identifiers are separated into ordinary identifiers, type names,
30 keywords and some other Objective-C types of identifiers, and some
31 look-ahead is maintained.
32
33 ??? It might be a good idea to lex the whole file up front (as for
34 C++). It would then be possible to share more of the C and C++
35 lexer code, if desired. */
36
37/* More information about the type of a CPP_NAME token. */
38enum c_id_kind {
39 /* An ordinary identifier. */
40 C_ID_ID,
41 /* An identifier declared as a typedef name. */
42 C_ID_TYPENAME,
43 /* An identifier declared as an Objective-C class name. */
44 C_ID_CLASSNAME,
45 /* An address space identifier. */
46 C_ID_ADDRSPACE,
47 /* Not an identifier. */
48 C_ID_NONE
49};
50
51/* A single C token after string literal concatenation and conversion
52 of preprocessing tokens to tokens. */
53struct GTY (()) c_token {
54 /* The kind of token. */
55 ENUM_BITFIELD (cpp_ttype) type : 8;
56 /* If this token is a CPP_NAME, this value indicates whether also
57 declared as some kind of type. Otherwise, it is C_ID_NONE. */
58 ENUM_BITFIELD (c_id_kind) id_kind : 8;
59 /* If this token is a keyword, this value indicates which keyword.
60 Otherwise, this value is RID_MAX. */
61 ENUM_BITFIELD (rid) keyword : 8;
62 /* If this token is a CPP_PRAGMA, this indicates the pragma that
63 was seen. Otherwise it is PRAGMA_NONE. */
64 ENUM_BITFIELD (pragma_kind) pragma_kind : 8;
65 /* The location at which this token was found. */
66 location_t location;
67 /* The value associated with this token, if any. */
68 tree value;
69 /* Token flags. */
70 unsigned char flags;
71
72 source_range get_range () const
73 {
74 return get_range_from_loc (set: line_table, loc: location);
75 }
76
77 location_t get_finish () const
78 {
79 return get_range ().m_finish;
80 }
81};
82
83/* This should have the same layout as c_tree_token_vec
84 in c-decl.cc, but for GTY reasons with ObjC can't be
85 GTY itself. */
86struct c_tree_token_vec_struct {
87 struct tree_base base;
88 vec<c_token, va_gc> *tokens;
89};
90
91#define C_TOKEN_VEC_TOKENS(NODE) \
92 (((struct c_tree_token_vec_struct *) TREE_CHECK (NODE, C_TOKEN_VEC))->tokens)
93
94/* The parser. */
95struct c_parser;
96
97/* Possibly kinds of declarator to parse. */
98enum c_dtr_syn {
99 /* A normal declarator with an identifier. */
100 C_DTR_NORMAL,
101 /* An abstract declarator (maybe empty). */
102 C_DTR_ABSTRACT,
103 /* A parameter declarator: may be either, but after a type name does
104 not redeclare a typedef name as an identifier if it can
105 alternatively be interpreted as a typedef name; see DR#009,
106 applied in C90 TC1, omitted from C99 and reapplied in C99 TC2
107 following DR#249. For example, given a typedef T, "int T" and
108 "int *T" are valid parameter declarations redeclaring T, while
109 "int (T)" and "int * (T)" and "int (T[])" and "int (T (int))" are
110 abstract declarators rather than involving redundant parentheses;
111 the same applies with attributes inside the parentheses before
112 "T". */
113 C_DTR_PARM
114};
115
116/* The binary operation precedence levels, where 0 is a dummy lowest level
117 used for the bottom of the stack. */
118enum c_parser_prec {
119 PREC_NONE,
120 PREC_LOGOR,
121 PREC_LOGAND,
122 PREC_BITOR,
123 PREC_BITXOR,
124 PREC_BITAND,
125 PREC_EQ,
126 PREC_REL,
127 PREC_SHIFT,
128 PREC_ADD,
129 PREC_MULT,
130 NUM_PRECS
131};
132
133enum c_lookahead_kind {
134 /* Always treat unknown identifiers as typenames. */
135 cla_prefer_type,
136
137 /* Could be parsing a nonabstract declarator. Only treat an identifier
138 as a typename if followed by another identifier or a star. */
139 cla_nonabstract_decl,
140
141 /* Never treat identifiers as typenames. */
142 cla_prefer_id
143};
144
145
146extern c_token * c_parser_peek_token (c_parser *parser);
147extern c_token * c_parser_peek_2nd_token (c_parser *parser);
148extern c_token * c_parser_peek_nth_token (c_parser *parser, unsigned int n);
149extern bool c_parser_require (c_parser *parser, enum cpp_ttype type,
150 const char *msgid,
151 location_t matching_location = UNKNOWN_LOCATION,
152 bool type_is_unique=true);
153extern bool c_parser_error (c_parser *parser, const char *gmsgid);
154extern void c_parser_consume_token (c_parser *parser);
155extern void c_parser_skip_until_found (c_parser *parser, enum cpp_ttype type,
156 const char *msgid,
157 location_t = UNKNOWN_LOCATION);
158extern bool c_parser_next_token_starts_declspecs (c_parser *parser);
159bool c_parser_next_tokens_start_declaration (c_parser *parser);
160bool c_token_starts_typename (c_token *token);
161
162/* Abstraction to avoid defining c_parser here which messes up gengtype
163 output wrt ObjC due to vec<c_token> routines being put in gtype-c.h
164 but not gtype-objc.h. */
165extern c_token * c_parser_tokens_buf (c_parser *parser, unsigned n);
166extern bool c_parser_error (c_parser *parser);
167extern void c_parser_set_error (c_parser *parser, bool);
168
169/* A bit of a hack to have this here. It would be better in a c-decl.h. */
170extern bool old_style_parameter_scope (void);
171
172/* Return true if the next token from PARSER has the indicated
173 TYPE. */
174
175inline bool
176c_parser_next_token_is (c_parser *parser, enum cpp_ttype type)
177{
178 return c_parser_peek_token (parser)->type == type;
179}
180
181/* Return true if the next token from PARSER does not have the
182 indicated TYPE. */
183
184inline bool
185c_parser_next_token_is_not (c_parser *parser, enum cpp_ttype type)
186{
187 return !c_parser_next_token_is (parser, type);
188}
189
190/* Return true if the next token from PARSER is the indicated
191 KEYWORD. */
192
193inline bool
194c_parser_next_token_is_keyword (c_parser *parser, enum rid keyword)
195{
196 return c_parser_peek_token (parser)->keyword == keyword;
197}
198
199struct c_expr c_parser_string_literal (c_parser *, bool, bool);
200extern struct c_declarator *
201c_parser_declarator (c_parser *parser, bool type_seen_p, c_dtr_syn kind,
202 bool *seen_id);
203extern void c_parser_declspecs (c_parser *, struct c_declspecs *, bool, bool,
204 bool, bool, bool, bool, bool,
205 enum c_lookahead_kind);
206extern struct c_type_name *c_parser_type_name (c_parser *, bool = false);
207extern bool c_maybe_parse_omp_decl (tree, tree);
208
209#endif
210

source code of gcc/c/c-parser.h