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
7 This file is part of GCC.
8
9 GCC is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 3, or (at your option) any later
12 version.
13
14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 for more details.
18
19 You should have received a copy of the GNU General Public License
20 along 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. */
38 enum 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. */
53 struct 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 (line_table, location);
75 }
76
77 location_t get_finish () const
78 {
79 return get_range ().m_finish;
80 }
81 };
82
83 /* The parser. */
84 struct c_parser;
85
86 /* Possibly kinds of declarator to parse. */
87 enum c_dtr_syn {
88 /* A normal declarator with an identifier. */
89 C_DTR_NORMAL,
90 /* An abstract declarator (maybe empty). */
91 C_DTR_ABSTRACT,
92 /* A parameter declarator: may be either, but after a type name does
93 not redeclare a typedef name as an identifier if it can
94 alternatively be interpreted as a typedef name; see DR#009,
95 applied in C90 TC1, omitted from C99 and reapplied in C99 TC2
96 following DR#249. For example, given a typedef T, "int T" and
97 "int *T" are valid parameter declarations redeclaring T, while
98 "int (T)" and "int * (T)" and "int (T[])" and "int (T (int))" are
99 abstract declarators rather than involving redundant parentheses;
100 the same applies with attributes inside the parentheses before
101 "T". */
102 C_DTR_PARM
103 };
104
105 /* The binary operation precedence levels, where 0 is a dummy lowest level
106 used for the bottom of the stack. */
107 enum c_parser_prec {
108 PREC_NONE,
109 PREC_LOGOR,
110 PREC_LOGAND,
111 PREC_BITOR,
112 PREC_BITXOR,
113 PREC_BITAND,
114 PREC_EQ,
115 PREC_REL,
116 PREC_SHIFT,
117 PREC_ADD,
118 PREC_MULT,
119 NUM_PRECS
120 };
121
122 enum c_lookahead_kind {
123 /* Always treat unknown identifiers as typenames. */
124 cla_prefer_type,
125
126 /* Could be parsing a nonabstract declarator. Only treat an identifier
127 as a typename if followed by another identifier or a star. */
128 cla_nonabstract_decl,
129
130 /* Never treat identifiers as typenames. */
131 cla_prefer_id
132 };
133
134
135 extern c_token * c_parser_peek_token (c_parser *parser);
136 extern c_token * c_parser_peek_2nd_token (c_parser *parser);
137 extern c_token * c_parser_peek_nth_token (c_parser *parser, unsigned int n);
138 extern bool c_parser_require (c_parser *parser, enum cpp_ttype type,
139 const char *msgid,
140 location_t matching_location = UNKNOWN_LOCATION,
141 bool type_is_unique=true);
142 extern bool c_parser_error (c_parser *parser, const char *gmsgid);
143 extern void c_parser_consume_token (c_parser *parser);
144 extern void c_parser_skip_until_found (c_parser *parser, enum cpp_ttype type,
145 const char *msgid,
146 location_t = UNKNOWN_LOCATION);
147 extern bool c_parser_next_token_starts_declspecs (c_parser *parser);
148 bool c_parser_next_tokens_start_declaration (c_parser *parser);
149 bool c_token_starts_typename (c_token *token);
150
151 /* Abstraction to avoid defining c_parser here which messes up gengtype
152 output wrt ObjC due to vec<c_token> routines being put in gtype-c.h
153 but not gtype-objc.h. */
154 extern c_token * c_parser_tokens_buf (c_parser *parser, unsigned n);
155 extern bool c_parser_error (c_parser *parser);
156 extern void c_parser_set_error (c_parser *parser, bool);
157
158 /* A bit of a hack to have this here. It would be better in a c-decl.h. */
159 extern bool old_style_parameter_scope (void);
160
161 /* Return true if the next token from PARSER has the indicated
162 TYPE. */
163
164 inline bool
165 c_parser_next_token_is (c_parser *parser, enum cpp_ttype type)
166 {
167 return c_parser_peek_token (parser)->type == type;
168 }
169
170 /* Return true if the next token from PARSER does not have the
171 indicated TYPE. */
172
173 inline bool
174 c_parser_next_token_is_not (c_parser *parser, enum cpp_ttype type)
175 {
176 return !c_parser_next_token_is (parser, type);
177 }
178
179 /* Return true if the next token from PARSER is the indicated
180 KEYWORD. */
181
182 inline bool
183 c_parser_next_token_is_keyword (c_parser *parser, enum rid keyword)
184 {
185 return c_parser_peek_token (parser)->keyword == keyword;
186 }
187
188 struct c_expr c_parser_string_literal (c_parser *, bool, bool);
189 extern struct c_declarator *
190 c_parser_declarator (c_parser *parser, bool type_seen_p, c_dtr_syn kind,
191 bool *seen_id);
192 extern void c_parser_declspecs (c_parser *, struct c_declspecs *, bool, bool,
193 bool, bool, bool, bool, bool,
194 enum c_lookahead_kind);
195 extern struct c_type_name *c_parser_type_name (c_parser *, bool = false);
196
197 #endif