1 /* Data structures and function exported by the C++ Parser. 2 Copyright (C) 2010 Free Software Foundation, Inc. 3 4 This file is part of GCC. 5 6 GCC is free software; you can redistribute it and/or modify it 7 under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3, or (at your option) 9 any later version. 10 11 GCC is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GCC; see the file COPYING3. If not see 18 <http://www.gnu.org/licenses/>. */ 19 20 #ifndef GCC_CP_PARSER_H 21 #define GCC_CP_PARSER_H 22 23 #include "tree.h" 24 #include "c-family/c-pragma.h" 25 26 /* A token's value and its associated deferred access checks and 27 qualifying scope. */ 28 29 struct GTY(()) tree_check { 30 /* The value associated with the token. */ 31 tree value; 32 /* The checks that have been associated with value. */ 33 VEC (deferred_access_check, gc)* checks; 34 /* The token's qualifying scope (used when it is a 35 CPP_NESTED_NAME_SPECIFIER). */ 36 tree qualifying_scope; 37 }; 38 39 /* A C++ token. */ 40 41 typedef struct GTY (()) cp_token { 42 /* The kind of token. */ 43 ENUM_BITFIELD (cpp_ttype) type : 8; 44 /* If this token is a keyword, this value indicates which keyword. 45 Otherwise, this value is RID_MAX. */ 46 ENUM_BITFIELD (rid) keyword : 8; 47 /* Token flags. */ 48 unsigned char flags; 49 /* Identifier for the pragma. */ 50 ENUM_BITFIELD (pragma_kind) pragma_kind : 6; 51 /* True if this token is from a context where it is implicitly extern "C" */ 52 BOOL_BITFIELD implicit_extern_c : 1; 53 /* True for a CPP_NAME token that is not a keyword (i.e., for which 54 KEYWORD is RID_MAX) iff this name was looked up and found to be 55 ambiguous. An error has already been reported. */ 56 BOOL_BITFIELD ambiguous_p : 1; 57 /* True for a token that has been purged. If a token is purged, 58 it is no longer a valid token and it should be considered 59 deleted. */ 60 BOOL_BITFIELD purged_p : 1; 61 /* The location at which this token was found. */ 62 location_t location; 63 /* The value associated with this token, if any. */ 64 union cp_token_value { 65 /* Used for CPP_NESTED_NAME_SPECIFIER and CPP_TEMPLATE_ID. */ 66 struct tree_check* GTY((tag ("1"))) tree_check_value; 67 /* Use for all other tokens. */ 68 tree GTY((tag ("0"))) value; 69 } GTY((desc ("(%1.type == CPP_TEMPLATE_ID) || (%1.type == CPP_NESTED_NAME_SPECIFIER)"))) u; 70 } cp_token; 71 72 DEF_VEC_O (cp_token); 73 DEF_VEC_ALLOC_O (cp_token,gc); 74 DEF_VEC_ALLOC_O (cp_token,heap); 75 76 /* We use a stack of token pointer for saving token sets. */ 77 typedef struct cp_token *cp_token_position; 78 DEF_VEC_P (cp_token_position); 79 DEF_VEC_ALLOC_P (cp_token_position,heap); 80 81 /* The cp_lexer structure represents the C++ lexer. It is responsible 82 for managing the token stream from the preprocessor and supplying 83 it to the parser. Tokens are never added to the cp_lexer after 84 it is created. */ 85 86 typedef struct GTY (()) cp_lexer { 87 /* The memory allocated for the buffer. NULL if this lexer does not 88 own the token buffer. */ 89 VEC(cp_token,gc) *buffer; 90 91 /* A pointer just past the last available token. The tokens 92 in this lexer are [buffer, last_token). */ 93 cp_token_position GTY ((skip)) last_token; 94 95 /* The next available token. If NEXT_TOKEN is &eof_token, then there are 96 no more available tokens. */ 97 cp_token_position GTY ((skip)) next_token; 98 99 /* A stack indicating positions at which cp_lexer_save_tokens was 100 called. The top entry is the most recent position at which we 101 began saving tokens. If the stack is non-empty, we are saving 102 tokens. */ 103 VEC(cp_token_position,heap) *GTY ((skip)) saved_tokens; 104 105 /* The next lexer in a linked list of lexers. */ 106 struct cp_lexer *next; 107 108 /* True if we should output debugging information. */ 109 bool debugging_p; 110 111 /* True if we're in the context of parsing a pragma, and should not 112 increment past the end-of-line marker. */ 113 bool in_pragma; 114 } cp_lexer; 115 116 DEF_VEC_O (cp_lexer); 117 DEF_VEC_ALLOC_O (cp_lexer,heap); 118 119 /* cp_token_cache is a range of tokens. There is no need to represent 120 allocate heap memory for it, since tokens are never removed from the 121 lexer's array. There is also no need for the GC to walk through 122 a cp_token_cache, since everything in here is referenced through 123 a lexer. */ 124 125 typedef struct GTY(()) cp_token_cache { 126 /* The beginning of the token range. */ 127 cp_token * GTY((skip)) first; 128 129 /* Points immediately after the last token in the range. */ 130 cp_token * GTY ((skip)) last; 131 } cp_token_cache; 132 133 typedef cp_token_cache *cp_token_cache_ptr; 134 DEF_VEC_P (cp_token_cache_ptr); 135 DEF_VEC_ALLOC_P (cp_token_cache_ptr,gc); 136 137 struct cp_token_ident_d 138 { 139 unsigned int ident_len; 140 const char *ident_str; 141 unsigned int before_len; 142 const char *before_str; 143 unsigned int after_len; 144 const char *after_str; 145 }; 146 147 typedef struct cp_token_ident_d cp_token_ident; 148 149 /* An entry in a queue of function arguments that require post-processing. */ 150 151 typedef struct GTY(()) cp_default_arg_entry_d { 152 /* The current_class_type when we parsed this arg. */ 153 tree class_type; 154 155 /* The function decl itself. */ 156 tree decl; 157 } cp_default_arg_entry; 158 159 DEF_VEC_O(cp_default_arg_entry); 160 DEF_VEC_ALLOC_O(cp_default_arg_entry,gc); 161 162 /* An entry in a stack for member functions of local classes. */ 163 164 typedef struct GTY(()) cp_unparsed_functions_entry_d { 165 /* Functions with default arguments that require post-processing. 166 Functions appear in this list in declaration order. */ 167 VEC(cp_default_arg_entry,gc) *funs_with_default_args; 168 169 /* Functions with defintions that require post-processing. Functions 170 appear in this list in declaration order. */ 171 VEC(tree,gc) *funs_with_definitions; 172 173 /* Non-static data members with initializers that require post-processing. 174 FIELD_DECLs appear in this list in declaration order. */ 175 VEC(tree,gc) *nsdmis; 176 } cp_unparsed_functions_entry; 177 178 DEF_VEC_O(cp_unparsed_functions_entry); 179 DEF_VEC_ALLOC_O(cp_unparsed_functions_entry,gc); 180 181 /* The status of a tentative parse. */ 182 183 typedef enum cp_parser_status_kind 184 { 185 /* No errors have occurred. */ 186 CP_PARSER_STATUS_KIND_NO_ERROR, 187 /* An error has occurred. */ 188 CP_PARSER_STATUS_KIND_ERROR, 189 /* We are committed to this tentative parse, whether or not an error 190 has occurred. */ 191 CP_PARSER_STATUS_KIND_COMMITTED 192 } cp_parser_status_kind; 193 194 195 /* Context that is saved and restored when parsing tentatively. */ 196 typedef struct GTY (()) cp_parser_context { 197 /* If this is a tentative parsing context, the status of the 198 tentative parse. */ 199 enum cp_parser_status_kind status; 200 /* If non-NULL, we have just seen a `x->' or `x.' expression. Names 201 that are looked up in this context must be looked up both in the 202 scope given by OBJECT_TYPE (the type of `x' or `*x') and also in 203 the context of the containing expression. */ 204 tree object_type; 205 206 /* The next parsing context in the stack. */ 207 struct cp_parser_context *next; 208 } cp_parser_context; 209 210 211 /* The cp_parser structure represents the C++ parser. */ 212 213 typedef struct GTY(()) cp_parser { 214 /* The lexer from which we are obtaining tokens. */ 215 cp_lexer *lexer; 216 217 /* The scope in which names should be looked up. If NULL_TREE, then 218 we look up names in the scope that is currently open in the 219 source program. If non-NULL, this is either a TYPE or 220 NAMESPACE_DECL for the scope in which we should look. It can 221 also be ERROR_MARK, when we've parsed a bogus scope. 222 223 This value is not cleared automatically after a name is looked 224 up, so we must be careful to clear it before starting a new look 225 up sequence. (If it is not cleared, then `X::Y' followed by `Z' 226 will look up `Z' in the scope of `X', rather than the current 227 scope.) Unfortunately, it is difficult to tell when name lookup 228 is complete, because we sometimes peek at a token, look it up, 229 and then decide not to consume it. */ 230 tree scope; 231 232 /* OBJECT_SCOPE and QUALIFYING_SCOPE give the scopes in which the 233 last lookup took place. OBJECT_SCOPE is used if an expression 234 like "x->y" or "x.y" was used; it gives the type of "*x" or "x", 235 respectively. QUALIFYING_SCOPE is used for an expression of the 236 form "X::Y"; it refers to X. */ 237 tree object_scope; 238 tree qualifying_scope; 239 240 /* A stack of parsing contexts. All but the bottom entry on the 241 stack will be tentative contexts. 242 243 We parse tentatively in order to determine which construct is in 244 use in some situations. For example, in order to determine 245 whether a statement is an expression-statement or a 246 declaration-statement we parse it tentatively as a 247 declaration-statement. If that fails, we then reparse the same 248 token stream as an expression-statement. */ 249 cp_parser_context *context; 250 251 /* True if we are parsing GNU C++. If this flag is not set, then 252 GNU extensions are not recognized. */ 253 bool allow_gnu_extensions_p; 254 255 /* TRUE if the `>' token should be interpreted as the greater-than 256 operator. FALSE if it is the end of a template-id or 257 template-parameter-list. In C++0x mode, this flag also applies to 258 `>>' tokens, which are viewed as two consecutive `>' tokens when 259 this flag is FALSE. */ 260 bool greater_than_is_operator_p; 261 262 /* TRUE if default arguments are allowed within a parameter list 263 that starts at this point. FALSE if only a gnu extension makes 264 them permissible. */ 265 bool default_arg_ok_p; 266 267 /* TRUE if we are parsing an integral constant-expression. See 268 [expr.const] for a precise definition. */ 269 bool integral_constant_expression_p; 270 271 /* TRUE if we are parsing an integral constant-expression -- but a 272 non-constant expression should be permitted as well. This flag 273 is used when parsing an array bound so that GNU variable-length 274 arrays are tolerated. */ 275 bool allow_non_integral_constant_expression_p; 276 277 /* TRUE if ALLOW_NON_CONSTANT_EXPRESSION_P is TRUE and something has 278 been seen that makes the expression non-constant. */ 279 bool non_integral_constant_expression_p; 280 281 /* TRUE if local variable names and `this' are forbidden in the 282 current context. */ 283 bool local_variables_forbidden_p; 284 285 /* TRUE if the declaration we are parsing is part of a 286 linkage-specification of the form `extern string-literal 287 declaration'. */ 288 bool in_unbraced_linkage_specification_p; 289 290 /* TRUE if we are presently parsing a declarator, after the 291 direct-declarator. */ 292 bool in_declarator_p; 293 294 /* TRUE if we are presently parsing a template-argument-list. */ 295 bool in_template_argument_list_p; 296 297 /* Set to IN_ITERATION_STMT if parsing an iteration-statement, 298 to IN_OMP_BLOCK if parsing OpenMP structured block and 299 IN_OMP_FOR if parsing OpenMP loop. If parsing a switch statement, 300 this is bitwise ORed with IN_SWITCH_STMT, unless parsing an 301 iteration-statement, OpenMP block or loop within that switch. */ 302 #define IN_SWITCH_STMT 1 303 #define IN_ITERATION_STMT 2 304 #define IN_OMP_BLOCK 4 305 #define IN_OMP_FOR 8 306 #define IN_IF_STMT 16 307 unsigned char in_statement; 308 309 /* TRUE if we are presently parsing the body of a switch statement. 310 Note that this doesn't quite overlap with in_statement above. 311 The difference relates to giving the right sets of error messages: 312 "case not in switch" vs "break statement used with OpenMP...". */ 313 bool in_switch_statement_p; 314 315 /* TRUE if we are parsing a type-id in an expression context. In 316 such a situation, both "type (expr)" and "type (type)" are valid 317 alternatives. */ 318 bool in_type_id_in_expr_p; 319 320 /* TRUE if we are currently in a header file where declarations are 321 implicitly extern "C". */ 322 bool implicit_extern_c; 323 324 /* TRUE if strings in expressions should be translated to the execution 325 character set. */ 326 bool translate_strings_p; 327 328 /* TRUE if we are presently parsing the body of a function, but not 329 a local class. */ 330 bool in_function_body; 331 332 /* Nonzero if we're processing a __transaction_atomic or 333 __transaction_relaxed statement. */ 334 unsigned char in_transaction; 335 336 /* TRUE if we can auto-correct a colon to a scope operator. */ 337 bool colon_corrects_to_scope_p; 338 339 /* If non-NULL, then we are parsing a construct where new type 340 definitions are not permitted. The string stored here will be 341 issued as an error message if a type is defined. */ 342 const char *type_definition_forbidden_message; 343 344 /* A stack used for member functions of local classes. The lists 345 contained in an individual entry can only be processed once the 346 outermost class being defined is complete. */ 347 VEC(cp_unparsed_functions_entry,gc) *unparsed_queues; 348 349 /* The number of classes whose definitions are currently in 350 progress. */ 351 unsigned num_classes_being_defined; 352 353 /* The number of template parameter lists that apply directly to the 354 current declaration. */ 355 unsigned num_template_parameter_lists; 356 } cp_parser; 357 358 /* In parser.c */ 359 extern void cp_lexer_debug_tokens (VEC(cp_token,gc) *); 360 extern void cp_debug_parser (FILE *, cp_parser *); 361 362 #endif /* GCC_CP_PARSER_H */ 363