| 1 | /* Parser definitions for GDB. |
| 2 | |
| 3 | Copyright (C) 1986-2019 Free Software Foundation, Inc. |
| 4 | |
| 5 | Modified from expread.y by the Department of Computer Science at the |
| 6 | State University of New York at Buffalo. |
| 7 | |
| 8 | This file is part of GDB. |
| 9 | |
| 10 | This program is free software; you can redistribute it and/or modify |
| 11 | it under the terms of the GNU General Public License as published by |
| 12 | the Free Software Foundation; either version 3 of the License, or |
| 13 | (at your option) any later version. |
| 14 | |
| 15 | This program is distributed in the hope that it will be useful, |
| 16 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | GNU General Public License for more details. |
| 19 | |
| 20 | You should have received a copy of the GNU General Public License |
| 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 22 | |
| 23 | #if !defined (PARSER_DEFS_H) |
| 24 | #define PARSER_DEFS_H 1 |
| 25 | |
| 26 | #include "expression.h" |
| 27 | #include "symtab.h" |
| 28 | |
| 29 | struct block; |
| 30 | struct language_defn; |
| 31 | struct internalvar; |
| 32 | class innermost_block_tracker; |
| 33 | |
| 34 | extern bool parser_debug; |
| 35 | |
| 36 | /* A class that can be used to build a "struct expression". */ |
| 37 | |
| 38 | struct expr_builder |
| 39 | { |
| 40 | /* Constructor. LANG is the language used to parse the expression. |
| 41 | And GDBARCH is the gdbarch to use during parsing. */ |
| 42 | |
| 43 | expr_builder (const struct language_defn *lang, |
| 44 | struct gdbarch *gdbarch); |
| 45 | |
| 46 | DISABLE_COPY_AND_ASSIGN (expr_builder); |
| 47 | |
| 48 | /* Resize the allocated expression to the correct size, and return |
| 49 | it as an expression_up -- passing ownership to the caller. */ |
| 50 | ATTRIBUTE_UNUSED_RESULT expression_up release (); |
| 51 | |
| 52 | /* Return the gdbarch that was passed to the constructor. */ |
| 53 | |
| 54 | struct gdbarch *gdbarch () |
| 55 | { |
| 56 | return expout->gdbarch; |
| 57 | } |
| 58 | |
| 59 | /* Return the language that was passed to the constructor. */ |
| 60 | |
| 61 | const struct language_defn *language () |
| 62 | { |
| 63 | return expout->language_defn; |
| 64 | } |
| 65 | |
| 66 | /* The size of the expression above. */ |
| 67 | |
| 68 | size_t expout_size; |
| 69 | |
| 70 | /* The expression related to this parser state. */ |
| 71 | |
| 72 | expression_up expout; |
| 73 | |
| 74 | /* The number of elements already in the expression. This is used |
| 75 | to know where to put new elements. */ |
| 76 | |
| 77 | size_t expout_ptr; |
| 78 | }; |
| 79 | |
| 80 | /* This is used for expression completion. */ |
| 81 | |
| 82 | struct expr_completion_state |
| 83 | { |
| 84 | /* The index of the last struct expression directly before a '.' or |
| 85 | '->'. This is set when parsing and is only used when completing a |
| 86 | field name. It is -1 if no dereference operation was found. */ |
| 87 | int expout_last_struct = -1; |
| 88 | |
| 89 | /* If we are completing a tagged type name, this will be nonzero. */ |
| 90 | enum type_code expout_tag_completion_type = TYPE_CODE_UNDEF; |
| 91 | |
| 92 | /* The token for tagged type name completion. */ |
| 93 | gdb::unique_xmalloc_ptr<char> expout_completion_name; |
| 94 | }; |
| 95 | |
| 96 | /* An instance of this type is instantiated during expression parsing, |
| 97 | and passed to the appropriate parser. It holds both inputs to the |
| 98 | parser, and result. */ |
| 99 | |
| 100 | struct parser_state : public expr_builder |
| 101 | { |
| 102 | /* Constructor. LANG is the language used to parse the expression. |
| 103 | And GDBARCH is the gdbarch to use during parsing. */ |
| 104 | |
| 105 | parser_state (const struct language_defn *lang, |
| 106 | struct gdbarch *gdbarch, |
| 107 | const struct block *context_block, |
| 108 | CORE_ADDR context_pc, |
| 109 | int comma, |
| 110 | const char *input, |
| 111 | int completion, |
| 112 | innermost_block_tracker *tracker) |
| 113 | : expr_builder (lang, gdbarch), |
| 114 | expression_context_block (context_block), |
| 115 | expression_context_pc (context_pc), |
| 116 | comma_terminates (comma), |
| 117 | lexptr (input), |
| 118 | parse_completion (completion), |
| 119 | block_tracker (tracker) |
| 120 | { |
| 121 | } |
| 122 | |
| 123 | DISABLE_COPY_AND_ASSIGN (parser_state); |
| 124 | |
| 125 | /* Begin counting arguments for a function call, |
| 126 | saving the data about any containing call. */ |
| 127 | |
| 128 | void start_arglist () |
| 129 | { |
| 130 | m_funcall_chain.push_back (arglist_len); |
| 131 | arglist_len = 0; |
| 132 | } |
| 133 | |
| 134 | /* Return the number of arguments in a function call just terminated, |
| 135 | and restore the data for the containing function call. */ |
| 136 | |
| 137 | int end_arglist () |
| 138 | { |
| 139 | int val = arglist_len; |
| 140 | arglist_len = m_funcall_chain.back (); |
| 141 | m_funcall_chain.pop_back (); |
| 142 | return val; |
| 143 | } |
| 144 | |
| 145 | /* Mark the current index as the starting location of a structure |
| 146 | expression. This is used when completing on field names. */ |
| 147 | |
| 148 | void mark_struct_expression (); |
| 149 | |
| 150 | /* Indicate that the current parser invocation is completing a tag. |
| 151 | TAG is the type code of the tag, and PTR and LENGTH represent the |
| 152 | start of the tag name. */ |
| 153 | |
| 154 | void mark_completion_tag (enum type_code tag, const char *ptr, int length); |
| 155 | |
| 156 | |
| 157 | /* If this is nonzero, this block is used as the lexical context for |
| 158 | symbol names. */ |
| 159 | |
| 160 | const struct block * const expression_context_block; |
| 161 | |
| 162 | /* If expression_context_block is non-zero, then this is the PC |
| 163 | within the block that we want to evaluate expressions at. When |
| 164 | debugging C or C++ code, we use this to find the exact line we're |
| 165 | at, and then look up the macro definitions active at that |
| 166 | point. */ |
| 167 | const CORE_ADDR expression_context_pc; |
| 168 | |
| 169 | /* Nonzero means stop parsing on first comma (if not within parentheses). */ |
| 170 | |
| 171 | int comma_terminates; |
| 172 | |
| 173 | /* During parsing of a C expression, the pointer to the next character |
| 174 | is in this variable. */ |
| 175 | |
| 176 | const char *lexptr; |
| 177 | |
| 178 | /* After a token has been recognized, this variable points to it. |
| 179 | Currently used only for error reporting. */ |
| 180 | const char *prev_lexptr = nullptr; |
| 181 | |
| 182 | /* Number of arguments seen so far in innermost function call. */ |
| 183 | |
| 184 | int arglist_len = 0; |
| 185 | |
| 186 | /* True if parsing an expression to attempt completion. */ |
| 187 | int parse_completion; |
| 188 | |
| 189 | /* Completion state is updated here. */ |
| 190 | expr_completion_state m_completion_state; |
| 191 | |
| 192 | /* The innermost block tracker. */ |
| 193 | innermost_block_tracker *block_tracker; |
| 194 | |
| 195 | private: |
| 196 | |
| 197 | /* Data structure for saving values of arglist_len for function calls whose |
| 198 | arguments contain other function calls. */ |
| 199 | |
| 200 | std::vector<int> m_funcall_chain; |
| 201 | }; |
| 202 | |
| 203 | /* When parsing expressions we track the innermost block that was |
| 204 | referenced. */ |
| 205 | |
| 206 | class innermost_block_tracker |
| 207 | { |
| 208 | public: |
| 209 | innermost_block_tracker (innermost_block_tracker_types types |
| 210 | = INNERMOST_BLOCK_FOR_SYMBOLS) |
| 211 | : m_types (types), |
| 212 | m_innermost_block (NULL) |
| 213 | { /* Nothing. */ } |
| 214 | |
| 215 | /* Update the stored innermost block if the new block B is more inner |
| 216 | than the currently stored block, or if no block is stored yet. The |
| 217 | type T tells us whether the block B was for a symbol or for a |
| 218 | register. The stored innermost block is only updated if the type T is |
| 219 | a type we are interested in, the types we are interested in are held |
| 220 | in M_TYPES and set during RESET. */ |
| 221 | void update (const struct block *b, innermost_block_tracker_types t); |
| 222 | |
| 223 | /* Overload of main UPDATE method which extracts the block from BS. */ |
| 224 | void update (const struct block_symbol &bs) |
| 225 | { |
| 226 | update (bs.block, INNERMOST_BLOCK_FOR_SYMBOLS); |
| 227 | } |
| 228 | |
| 229 | /* Return the stored innermost block. Can be nullptr if no symbols or |
| 230 | registers were found during an expression parse, and so no innermost |
| 231 | block was defined. */ |
| 232 | const struct block *block () const |
| 233 | { |
| 234 | return m_innermost_block; |
| 235 | } |
| 236 | |
| 237 | private: |
| 238 | /* The type of innermost block being looked for. */ |
| 239 | innermost_block_tracker_types m_types; |
| 240 | |
| 241 | /* The currently stored innermost block found while parsing an |
| 242 | expression. */ |
| 243 | const struct block *m_innermost_block; |
| 244 | }; |
| 245 | |
| 246 | /* A string token, either a char-string or bit-string. Char-strings are |
| 247 | used, for example, for the names of symbols. */ |
| 248 | |
| 249 | struct stoken |
| 250 | { |
| 251 | /* Pointer to first byte of char-string or first bit of bit-string. */ |
| 252 | const char *ptr; |
| 253 | /* Length of string in bytes for char-string or bits for bit-string. */ |
| 254 | int length; |
| 255 | }; |
| 256 | |
| 257 | struct typed_stoken |
| 258 | { |
| 259 | /* A language-specific type field. */ |
| 260 | int type; |
| 261 | /* Pointer to first byte of char-string or first bit of bit-string. */ |
| 262 | char *ptr; |
| 263 | /* Length of string in bytes for char-string or bits for bit-string. */ |
| 264 | int length; |
| 265 | }; |
| 266 | |
| 267 | struct stoken_vector |
| 268 | { |
| 269 | int len; |
| 270 | struct typed_stoken *tokens; |
| 271 | }; |
| 272 | |
| 273 | struct ttype |
| 274 | { |
| 275 | struct stoken stoken; |
| 276 | struct type *type; |
| 277 | }; |
| 278 | |
| 279 | struct symtoken |
| 280 | { |
| 281 | struct stoken stoken; |
| 282 | struct block_symbol sym; |
| 283 | int is_a_field_of_this; |
| 284 | }; |
| 285 | |
| 286 | struct objc_class_str |
| 287 | { |
| 288 | struct stoken stoken; |
| 289 | struct type *type; |
| 290 | int theclass; |
| 291 | }; |
| 292 | |
| 293 | /* Reverse an expression from suffix form (in which it is constructed) |
| 294 | to prefix form (in which we can conveniently print or execute it). |
| 295 | Ordinarily this always returns -1. However, if LAST_STRUCT |
| 296 | is not -1 (i.e., we are trying to complete a field name), it will |
| 297 | return the index of the subexpression which is the left-hand-side |
| 298 | of the struct operation at LAST_STRUCT. */ |
| 299 | |
| 300 | extern int prefixify_expression (struct expression *expr, |
| 301 | int last_struct = -1); |
| 302 | |
| 303 | extern void write_exp_elt_opcode (struct expr_builder *, enum exp_opcode); |
| 304 | |
| 305 | extern void write_exp_elt_sym (struct expr_builder *, struct symbol *); |
| 306 | |
| 307 | extern void write_exp_elt_longcst (struct expr_builder *, LONGEST); |
| 308 | |
| 309 | extern void write_exp_elt_floatcst (struct expr_builder *, const gdb_byte *); |
| 310 | |
| 311 | extern void write_exp_elt_type (struct expr_builder *, struct type *); |
| 312 | |
| 313 | extern void write_exp_elt_intern (struct expr_builder *, struct internalvar *); |
| 314 | |
| 315 | extern void write_exp_string (struct expr_builder *, struct stoken); |
| 316 | |
| 317 | void write_exp_string_vector (struct expr_builder *, int type, |
| 318 | struct stoken_vector *vec); |
| 319 | |
| 320 | extern void write_exp_bitstring (struct expr_builder *, struct stoken); |
| 321 | |
| 322 | extern void write_exp_elt_block (struct expr_builder *, const struct block *); |
| 323 | |
| 324 | extern void write_exp_elt_objfile (struct expr_builder *, |
| 325 | struct objfile *objfile); |
| 326 | |
| 327 | extern void write_exp_msymbol (struct expr_builder *, |
| 328 | struct bound_minimal_symbol); |
| 329 | |
| 330 | extern void write_dollar_variable (struct parser_state *, struct stoken str); |
| 331 | |
| 332 | extern const char *find_template_name_end (const char *); |
| 333 | |
| 334 | extern std::string copy_name (struct stoken); |
| 335 | |
| 336 | extern int dump_subexp (struct expression *, struct ui_file *, int); |
| 337 | |
| 338 | extern int dump_subexp_body_standard (struct expression *, |
| 339 | struct ui_file *, int); |
| 340 | |
| 341 | extern void operator_length (const struct expression *, int, int *, int *); |
| 342 | |
| 343 | extern void operator_length_standard (const struct expression *, int, int *, |
| 344 | int *); |
| 345 | |
| 346 | extern int operator_check_standard (struct expression *exp, int pos, |
| 347 | int (*objfile_func) |
| 348 | (struct objfile *objfile, void *data), |
| 349 | void *data); |
| 350 | |
| 351 | extern const char *op_name_standard (enum exp_opcode); |
| 352 | |
| 353 | extern void null_post_parser (expression_up *, int, int, |
| 354 | innermost_block_tracker *); |
| 355 | |
| 356 | extern bool parse_float (const char *p, int len, |
| 357 | const struct type *type, gdb_byte *data); |
| 358 | \f |
| 359 | /* These codes indicate operator precedences for expression printing, |
| 360 | least tightly binding first. */ |
| 361 | /* Adding 1 to a precedence value is done for binary operators, |
| 362 | on the operand which is more tightly bound, so that operators |
| 363 | of equal precedence within that operand will get parentheses. */ |
| 364 | /* PREC_HYPER and PREC_ABOVE_COMMA are not the precedence of any operator; |
| 365 | they are used as the "surrounding precedence" to force |
| 366 | various kinds of things to be parenthesized. */ |
| 367 | enum precedence |
| 368 | { |
| 369 | PREC_NULL, PREC_COMMA, PREC_ABOVE_COMMA, PREC_ASSIGN, PREC_LOGICAL_OR, |
| 370 | PREC_LOGICAL_AND, PREC_BITWISE_IOR, PREC_BITWISE_AND, PREC_BITWISE_XOR, |
| 371 | PREC_EQUAL, PREC_ORDER, PREC_SHIFT, PREC_ADD, PREC_MUL, PREC_REPEAT, |
| 372 | PREC_HYPER, PREC_PREFIX, PREC_SUFFIX, PREC_BUILTIN_FUNCTION |
| 373 | }; |
| 374 | |
| 375 | /* Table mapping opcodes into strings for printing operators |
| 376 | and precedences of the operators. */ |
| 377 | |
| 378 | struct op_print |
| 379 | { |
| 380 | const char *string; |
| 381 | enum exp_opcode opcode; |
| 382 | /* Precedence of operator. These values are used only by comparisons. */ |
| 383 | enum precedence precedence; |
| 384 | |
| 385 | /* For a binary operator: 1 iff right associate. |
| 386 | For a unary operator: 1 iff postfix. */ |
| 387 | int right_assoc; |
| 388 | }; |
| 389 | |
| 390 | /* Information needed to print, prefixify, and evaluate expressions for |
| 391 | a given language. */ |
| 392 | |
| 393 | struct exp_descriptor |
| 394 | { |
| 395 | /* Print subexpression. */ |
| 396 | void (*print_subexp) (struct expression *, int *, struct ui_file *, |
| 397 | enum precedence); |
| 398 | |
| 399 | /* Returns number of exp_elements needed to represent an operator and |
| 400 | the number of subexpressions it takes. */ |
| 401 | void (*operator_length) (const struct expression*, int, int*, int *); |
| 402 | |
| 403 | /* Call OBJFILE_FUNC for any objfile found being referenced by the |
| 404 | single operator of EXP at position POS. Operator parameters are |
| 405 | located at positive (POS + number) offsets in EXP. OBJFILE_FUNC |
| 406 | should never be called with NULL OBJFILE. OBJFILE_FUNC should |
| 407 | get passed an arbitrary caller supplied DATA pointer. If it |
| 408 | returns non-zero value then (any other) non-zero value should be |
| 409 | immediately returned to the caller. Otherwise zero should be |
| 410 | returned. */ |
| 411 | int (*operator_check) (struct expression *exp, int pos, |
| 412 | int (*objfile_func) (struct objfile *objfile, |
| 413 | void *data), |
| 414 | void *data); |
| 415 | |
| 416 | /* Name of this operator for dumping purposes. |
| 417 | The returned value should never be NULL, even if EXP_OPCODE is |
| 418 | an unknown opcode (a string containing an image of the numeric |
| 419 | value of the opcode can be returned, for instance). */ |
| 420 | const char *(*op_name) (enum exp_opcode); |
| 421 | |
| 422 | /* Dump the rest of this (prefix) expression after the operator |
| 423 | itself has been printed. See dump_subexp_body_standard in |
| 424 | (expprint.c). */ |
| 425 | int (*dump_subexp_body) (struct expression *, struct ui_file *, int); |
| 426 | |
| 427 | /* Evaluate an expression. */ |
| 428 | struct value *(*evaluate_exp) (struct type *, struct expression *, |
| 429 | int *, enum noside); |
| 430 | }; |
| 431 | |
| 432 | |
| 433 | /* Default descriptor containing standard definitions of all |
| 434 | elements. */ |
| 435 | extern const struct exp_descriptor exp_descriptor_standard; |
| 436 | |
| 437 | /* Functions used by language-specific extended operators to (recursively) |
| 438 | print/dump subexpressions. */ |
| 439 | |
| 440 | extern void print_subexp (struct expression *, int *, struct ui_file *, |
| 441 | enum precedence); |
| 442 | |
| 443 | extern void print_subexp_standard (struct expression *, int *, |
| 444 | struct ui_file *, enum precedence); |
| 445 | |
| 446 | /* Function used to avoid direct calls to fprintf |
| 447 | in the code generated by the bison parser. */ |
| 448 | |
| 449 | extern void parser_fprintf (FILE *, const char *, ...) ATTRIBUTE_PRINTF (2, 3); |
| 450 | |
| 451 | extern int exp_uses_objfile (struct expression *exp, struct objfile *objfile); |
| 452 | |
| 453 | #endif /* PARSER_DEFS_H */ |
| 454 | |