| 1 | /* Parse expressions for GDB. |
| 2 | |
| 3 | Copyright (C) 1986, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, |
| 4 | 1998, 1999, 2000, 2001, 2004, 2005, 2007, 2008, 2009, 2010, 2011 |
| 5 | Free Software Foundation, Inc. |
| 6 | |
| 7 | Modified from expread.y by the Department of Computer Science at the |
| 8 | State University of New York at Buffalo, 1991. |
| 9 | |
| 10 | This file is part of GDB. |
| 11 | |
| 12 | This program is free software; you can redistribute it and/or modify |
| 13 | it under the terms of the GNU General Public License as published by |
| 14 | the Free Software Foundation; either version 3 of the License, or |
| 15 | (at your option) any later version. |
| 16 | |
| 17 | This program is distributed in the hope that it will be useful, |
| 18 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | GNU General Public License for more details. |
| 21 | |
| 22 | You should have received a copy of the GNU General Public License |
| 23 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 24 | |
| 25 | /* Parse an expression from text in a string, |
| 26 | and return the result as a struct expression pointer. |
| 27 | That structure contains arithmetic operations in reverse polish, |
| 28 | with constants represented by operations that are followed by special data. |
| 29 | See expression.h for the details of the format. |
| 30 | What is important here is that it can be built up sequentially |
| 31 | during the process of parsing; the lower levels of the tree always |
| 32 | come first in the result. */ |
| 33 | |
| 34 | #include "defs.h" |
| 35 | #include <ctype.h> |
| 36 | #include "arch-utils.h" |
| 37 | #include "gdb_string.h" |
| 38 | #include "symtab.h" |
| 39 | #include "gdbtypes.h" |
| 40 | #include "frame.h" |
| 41 | #include "expression.h" |
| 42 | #include "value.h" |
| 43 | #include "command.h" |
| 44 | #include "language.h" |
| 45 | #include "f-lang.h" |
| 46 | #include "parser-defs.h" |
| 47 | #include "gdbcmd.h" |
| 48 | #include "symfile.h" /* for overlay functions */ |
| 49 | #include "inferior.h" |
| 50 | #include "doublest.h" |
| 51 | #include "gdb_assert.h" |
| 52 | #include "block.h" |
| 53 | #include "source.h" |
| 54 | #include "objfiles.h" |
| 55 | #include "exceptions.h" |
| 56 | #include "user-regs.h" |
| 57 | |
| 58 | /* Standard set of definitions for printing, dumping, prefixifying, |
| 59 | * and evaluating expressions. */ |
| 60 | |
| 61 | const struct exp_descriptor exp_descriptor_standard = |
| 62 | { |
| 63 | print_subexp_standard, |
| 64 | operator_length_standard, |
| 65 | operator_check_standard, |
| 66 | op_name_standard, |
| 67 | dump_subexp_body_standard, |
| 68 | evaluate_subexp_standard |
| 69 | }; |
| 70 | \f |
| 71 | /* Global variables declared in parser-defs.h (and commented there). */ |
| 72 | struct expression *expout; |
| 73 | int expout_size; |
| 74 | int expout_ptr; |
| 75 | struct block *expression_context_block; |
| 76 | CORE_ADDR expression_context_pc; |
| 77 | struct block *innermost_block; |
| 78 | int arglist_len; |
| 79 | union type_stack_elt *type_stack; |
| 80 | int type_stack_depth, type_stack_size; |
| 81 | char *lexptr; |
| 82 | char *prev_lexptr; |
| 83 | int paren_depth; |
| 84 | int comma_terminates; |
| 85 | |
| 86 | /* True if parsing an expression to find a field reference. This is |
| 87 | only used by completion. */ |
| 88 | int in_parse_field; |
| 89 | |
| 90 | /* The index of the last struct expression directly before a '.' or |
| 91 | '->'. This is set when parsing and is only used when completing a |
| 92 | field name. It is -1 if no dereference operation was found. */ |
| 93 | static int expout_last_struct = -1; |
| 94 | |
| 95 | /* A temporary buffer for identifiers, so we can null-terminate them. |
| 96 | |
| 97 | We allocate this with xrealloc. parse_exp_1 used to allocate with |
| 98 | alloca, using the size of the whole expression as a conservative |
| 99 | estimate of the space needed. However, macro expansion can |
| 100 | introduce names longer than the original expression; there's no |
| 101 | practical way to know beforehand how large that might be. */ |
| 102 | char *namecopy; |
| 103 | size_t namecopy_size; |
| 104 | \f |
| 105 | static int expressiondebug = 0; |
| 106 | static void |
| 107 | show_expressiondebug (struct ui_file *file, int from_tty, |
| 108 | struct cmd_list_element *c, const char *value) |
| 109 | { |
| 110 | fprintf_filtered (file, _("Expression debugging is %s.\n"), value); |
| 111 | } |
| 112 | |
| 113 | |
| 114 | /* Non-zero if an expression parser should set yydebug. */ |
| 115 | int parser_debug; |
| 116 | |
| 117 | static void |
| 118 | show_parserdebug (struct ui_file *file, int from_tty, |
| 119 | struct cmd_list_element *c, const char *value) |
| 120 | { |
| 121 | fprintf_filtered (file, _("Parser debugging is %s.\n"), value); |
| 122 | } |
| 123 | |
| 124 | |
| 125 | static void free_funcalls (void *ignore); |
| 126 | |
| 127 | static int prefixify_expression (struct expression *); |
| 128 | |
| 129 | static int prefixify_subexp (struct expression *, struct expression *, int, |
| 130 | int); |
| 131 | |
| 132 | static struct expression *parse_exp_in_context (char **, struct block *, int, |
| 133 | int, int *); |
| 134 | |
| 135 | void _initialize_parse (void); |
| 136 | |
| 137 | /* Data structure for saving values of arglist_len for function calls whose |
| 138 | arguments contain other function calls. */ |
| 139 | |
| 140 | struct funcall |
| 141 | { |
| 142 | struct funcall *next; |
| 143 | int arglist_len; |
| 144 | }; |
| 145 | |
| 146 | static struct funcall *funcall_chain; |
| 147 | |
| 148 | /* Begin counting arguments for a function call, |
| 149 | saving the data about any containing call. */ |
| 150 | |
| 151 | void |
| 152 | start_arglist (void) |
| 153 | { |
| 154 | struct funcall *new; |
| 155 | |
| 156 | new = (struct funcall *) xmalloc (sizeof (struct funcall)); |
| 157 | new->next = funcall_chain; |
| 158 | new->arglist_len = arglist_len; |
| 159 | arglist_len = 0; |
| 160 | funcall_chain = new; |
| 161 | } |
| 162 | |
| 163 | /* Return the number of arguments in a function call just terminated, |
| 164 | and restore the data for the containing function call. */ |
| 165 | |
| 166 | int |
| 167 | end_arglist (void) |
| 168 | { |
| 169 | int val = arglist_len; |
| 170 | struct funcall *call = funcall_chain; |
| 171 | |
| 172 | funcall_chain = call->next; |
| 173 | arglist_len = call->arglist_len; |
| 174 | xfree (call); |
| 175 | return val; |
| 176 | } |
| 177 | |
| 178 | /* Free everything in the funcall chain. |
| 179 | Used when there is an error inside parsing. */ |
| 180 | |
| 181 | static void |
| 182 | free_funcalls (void *ignore) |
| 183 | { |
| 184 | struct funcall *call, *next; |
| 185 | |
| 186 | for (call = funcall_chain; call; call = next) |
| 187 | { |
| 188 | next = call->next; |
| 189 | xfree (call); |
| 190 | } |
| 191 | } |
| 192 | \f |
| 193 | /* This page contains the functions for adding data to the struct expression |
| 194 | being constructed. */ |
| 195 | |
| 196 | /* Add one element to the end of the expression. */ |
| 197 | |
| 198 | /* To avoid a bug in the Sun 4 compiler, we pass things that can fit into |
| 199 | a register through here. */ |
| 200 | |
| 201 | void |
| 202 | write_exp_elt (union exp_element expelt) |
| 203 | { |
| 204 | if (expout_ptr >= expout_size) |
| 205 | { |
| 206 | expout_size *= 2; |
| 207 | expout = (struct expression *) |
| 208 | xrealloc ((char *) expout, sizeof (struct expression) |
| 209 | + EXP_ELEM_TO_BYTES (expout_size)); |
| 210 | } |
| 211 | expout->elts[expout_ptr++] = expelt; |
| 212 | } |
| 213 | |
| 214 | void |
| 215 | write_exp_elt_opcode (enum exp_opcode expelt) |
| 216 | { |
| 217 | union exp_element tmp; |
| 218 | |
| 219 | memset (&tmp, 0, sizeof (union exp_element)); |
| 220 | tmp.opcode = expelt; |
| 221 | write_exp_elt (tmp); |
| 222 | } |
| 223 | |
| 224 | void |
| 225 | write_exp_elt_sym (struct symbol *expelt) |
| 226 | { |
| 227 | union exp_element tmp; |
| 228 | |
| 229 | memset (&tmp, 0, sizeof (union exp_element)); |
| 230 | tmp.symbol = expelt; |
| 231 | write_exp_elt (tmp); |
| 232 | } |
| 233 | |
| 234 | void |
| 235 | write_exp_elt_block (struct block *b) |
| 236 | { |
| 237 | union exp_element tmp; |
| 238 | |
| 239 | memset (&tmp, 0, sizeof (union exp_element)); |
| 240 | tmp.block = b; |
| 241 | write_exp_elt (tmp); |
| 242 | } |
| 243 | |
| 244 | void |
| 245 | write_exp_elt_objfile (struct objfile *objfile) |
| 246 | { |
| 247 | union exp_element tmp; |
| 248 | |
| 249 | memset (&tmp, 0, sizeof (union exp_element)); |
| 250 | tmp.objfile = objfile; |
| 251 | write_exp_elt (tmp); |
| 252 | } |
| 253 | |
| 254 | void |
| 255 | write_exp_elt_longcst (LONGEST expelt) |
| 256 | { |
| 257 | union exp_element tmp; |
| 258 | |
| 259 | memset (&tmp, 0, sizeof (union exp_element)); |
| 260 | tmp.longconst = expelt; |
| 261 | write_exp_elt (tmp); |
| 262 | } |
| 263 | |
| 264 | void |
| 265 | write_exp_elt_dblcst (DOUBLEST expelt) |
| 266 | { |
| 267 | union exp_element tmp; |
| 268 | |
| 269 | memset (&tmp, 0, sizeof (union exp_element)); |
| 270 | tmp.doubleconst = expelt; |
| 271 | write_exp_elt (tmp); |
| 272 | } |
| 273 | |
| 274 | void |
| 275 | write_exp_elt_decfloatcst (gdb_byte expelt[16]) |
| 276 | { |
| 277 | union exp_element tmp; |
| 278 | int index; |
| 279 | |
| 280 | for (index = 0; index < 16; index++) |
| 281 | tmp.decfloatconst[index] = expelt[index]; |
| 282 | |
| 283 | write_exp_elt (tmp); |
| 284 | } |
| 285 | |
| 286 | void |
| 287 | write_exp_elt_type (struct type *expelt) |
| 288 | { |
| 289 | union exp_element tmp; |
| 290 | |
| 291 | memset (&tmp, 0, sizeof (union exp_element)); |
| 292 | tmp.type = expelt; |
| 293 | write_exp_elt (tmp); |
| 294 | } |
| 295 | |
| 296 | void |
| 297 | write_exp_elt_intern (struct internalvar *expelt) |
| 298 | { |
| 299 | union exp_element tmp; |
| 300 | |
| 301 | memset (&tmp, 0, sizeof (union exp_element)); |
| 302 | tmp.internalvar = expelt; |
| 303 | write_exp_elt (tmp); |
| 304 | } |
| 305 | |
| 306 | /* Add a string constant to the end of the expression. |
| 307 | |
| 308 | String constants are stored by first writing an expression element |
| 309 | that contains the length of the string, then stuffing the string |
| 310 | constant itself into however many expression elements are needed |
| 311 | to hold it, and then writing another expression element that contains |
| 312 | the length of the string. I.e. an expression element at each end of |
| 313 | the string records the string length, so you can skip over the |
| 314 | expression elements containing the actual string bytes from either |
| 315 | end of the string. Note that this also allows gdb to handle |
| 316 | strings with embedded null bytes, as is required for some languages. |
| 317 | |
| 318 | Don't be fooled by the fact that the string is null byte terminated, |
| 319 | this is strictly for the convenience of debugging gdb itself. |
| 320 | Gdb does not depend up the string being null terminated, since the |
| 321 | actual length is recorded in expression elements at each end of the |
| 322 | string. The null byte is taken into consideration when computing how |
| 323 | many expression elements are required to hold the string constant, of |
| 324 | course. */ |
| 325 | |
| 326 | |
| 327 | void |
| 328 | write_exp_string (struct stoken str) |
| 329 | { |
| 330 | int len = str.length; |
| 331 | int lenelt; |
| 332 | char *strdata; |
| 333 | |
| 334 | /* Compute the number of expression elements required to hold the string |
| 335 | (including a null byte terminator), along with one expression element |
| 336 | at each end to record the actual string length (not including the |
| 337 | null byte terminator). */ |
| 338 | |
| 339 | lenelt = 2 + BYTES_TO_EXP_ELEM (len + 1); |
| 340 | |
| 341 | /* Ensure that we have enough available expression elements to store |
| 342 | everything. */ |
| 343 | |
| 344 | if ((expout_ptr + lenelt) >= expout_size) |
| 345 | { |
| 346 | expout_size = max (expout_size * 2, expout_ptr + lenelt + 10); |
| 347 | expout = (struct expression *) |
| 348 | xrealloc ((char *) expout, (sizeof (struct expression) |
| 349 | + EXP_ELEM_TO_BYTES (expout_size))); |
| 350 | } |
| 351 | |
| 352 | /* Write the leading length expression element (which advances the current |
| 353 | expression element index), then write the string constant followed by a |
| 354 | terminating null byte, and then write the trailing length expression |
| 355 | element. */ |
| 356 | |
| 357 | write_exp_elt_longcst ((LONGEST) len); |
| 358 | strdata = (char *) &expout->elts[expout_ptr]; |
| 359 | memcpy (strdata, str.ptr, len); |
| 360 | *(strdata + len) = '\0'; |
| 361 | expout_ptr += lenelt - 2; |
| 362 | write_exp_elt_longcst ((LONGEST) len); |
| 363 | } |
| 364 | |
| 365 | /* Add a vector of string constants to the end of the expression. |
| 366 | |
| 367 | This adds an OP_STRING operation, but encodes the contents |
| 368 | differently from write_exp_string. The language is expected to |
| 369 | handle evaluation of this expression itself. |
| 370 | |
| 371 | After the usual OP_STRING header, TYPE is written into the |
| 372 | expression as a long constant. The interpretation of this field is |
| 373 | up to the language evaluator. |
| 374 | |
| 375 | Next, each string in VEC is written. The length is written as a |
| 376 | long constant, followed by the contents of the string. */ |
| 377 | |
| 378 | void |
| 379 | write_exp_string_vector (int type, struct stoken_vector *vec) |
| 380 | { |
| 381 | int i, n_slots, len; |
| 382 | |
| 383 | /* Compute the size. We compute the size in number of slots to |
| 384 | avoid issues with string padding. */ |
| 385 | n_slots = 0; |
| 386 | for (i = 0; i < vec->len; ++i) |
| 387 | { |
| 388 | /* One slot for the length of this element, plus the number of |
| 389 | slots needed for this string. */ |
| 390 | n_slots += 1 + BYTES_TO_EXP_ELEM (vec->tokens[i].length); |
| 391 | } |
| 392 | |
| 393 | /* One more slot for the type of the string. */ |
| 394 | ++n_slots; |
| 395 | |
| 396 | /* Now compute a phony string length. */ |
| 397 | len = EXP_ELEM_TO_BYTES (n_slots) - 1; |
| 398 | |
| 399 | n_slots += 4; |
| 400 | if ((expout_ptr + n_slots) >= expout_size) |
| 401 | { |
| 402 | expout_size = max (expout_size * 2, expout_ptr + n_slots + 10); |
| 403 | expout = (struct expression *) |
| 404 | xrealloc ((char *) expout, (sizeof (struct expression) |
| 405 | + EXP_ELEM_TO_BYTES (expout_size))); |
| 406 | } |
| 407 | |
| 408 | write_exp_elt_opcode (OP_STRING); |
| 409 | write_exp_elt_longcst (len); |
| 410 | write_exp_elt_longcst (type); |
| 411 | |
| 412 | for (i = 0; i < vec->len; ++i) |
| 413 | { |
| 414 | write_exp_elt_longcst (vec->tokens[i].length); |
| 415 | memcpy (&expout->elts[expout_ptr], vec->tokens[i].ptr, |
| 416 | vec->tokens[i].length); |
| 417 | expout_ptr += BYTES_TO_EXP_ELEM (vec->tokens[i].length); |
| 418 | } |
| 419 | |
| 420 | write_exp_elt_longcst (len); |
| 421 | write_exp_elt_opcode (OP_STRING); |
| 422 | } |
| 423 | |
| 424 | /* Add a bitstring constant to the end of the expression. |
| 425 | |
| 426 | Bitstring constants are stored by first writing an expression element |
| 427 | that contains the length of the bitstring (in bits), then stuffing the |
| 428 | bitstring constant itself into however many expression elements are |
| 429 | needed to hold it, and then writing another expression element that |
| 430 | contains the length of the bitstring. I.e. an expression element at |
| 431 | each end of the bitstring records the bitstring length, so you can skip |
| 432 | over the expression elements containing the actual bitstring bytes from |
| 433 | either end of the bitstring. */ |
| 434 | |
| 435 | void |
| 436 | write_exp_bitstring (struct stoken str) |
| 437 | { |
| 438 | int bits = str.length; /* length in bits */ |
| 439 | int len = (bits + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; |
| 440 | int lenelt; |
| 441 | char *strdata; |
| 442 | |
| 443 | /* Compute the number of expression elements required to hold the bitstring, |
| 444 | along with one expression element at each end to record the actual |
| 445 | bitstring length in bits. */ |
| 446 | |
| 447 | lenelt = 2 + BYTES_TO_EXP_ELEM (len); |
| 448 | |
| 449 | /* Ensure that we have enough available expression elements to store |
| 450 | everything. */ |
| 451 | |
| 452 | if ((expout_ptr + lenelt) >= expout_size) |
| 453 | { |
| 454 | expout_size = max (expout_size * 2, expout_ptr + lenelt + 10); |
| 455 | expout = (struct expression *) |
| 456 | xrealloc ((char *) expout, (sizeof (struct expression) |
| 457 | + EXP_ELEM_TO_BYTES (expout_size))); |
| 458 | } |
| 459 | |
| 460 | /* Write the leading length expression element (which advances the current |
| 461 | expression element index), then write the bitstring constant, and then |
| 462 | write the trailing length expression element. */ |
| 463 | |
| 464 | write_exp_elt_longcst ((LONGEST) bits); |
| 465 | strdata = (char *) &expout->elts[expout_ptr]; |
| 466 | memcpy (strdata, str.ptr, len); |
| 467 | expout_ptr += lenelt - 2; |
| 468 | write_exp_elt_longcst ((LONGEST) bits); |
| 469 | } |
| 470 | |
| 471 | /* Add the appropriate elements for a minimal symbol to the end of |
| 472 | the expression. */ |
| 473 | |
| 474 | void |
| 475 | write_exp_msymbol (struct minimal_symbol *msymbol) |
| 476 | { |
| 477 | struct objfile *objfile = msymbol_objfile (msymbol); |
| 478 | struct gdbarch *gdbarch = get_objfile_arch (objfile); |
| 479 | |
| 480 | CORE_ADDR addr = SYMBOL_VALUE_ADDRESS (msymbol); |
| 481 | struct obj_section *section = SYMBOL_OBJ_SECTION (msymbol); |
| 482 | enum minimal_symbol_type type = MSYMBOL_TYPE (msymbol); |
| 483 | CORE_ADDR pc; |
| 484 | |
| 485 | /* The minimal symbol might point to a function descriptor; |
| 486 | resolve it to the actual code address instead. */ |
| 487 | pc = gdbarch_convert_from_func_ptr_addr (gdbarch, addr, ¤t_target); |
| 488 | if (pc != addr) |
| 489 | { |
| 490 | struct minimal_symbol *ifunc_msym = lookup_minimal_symbol_by_pc (pc); |
| 491 | |
| 492 | /* In this case, assume we have a code symbol instead of |
| 493 | a data symbol. */ |
| 494 | |
| 495 | if (ifunc_msym != NULL && MSYMBOL_TYPE (ifunc_msym) == mst_text_gnu_ifunc |
| 496 | && SYMBOL_VALUE_ADDRESS (ifunc_msym) == pc) |
| 497 | { |
| 498 | /* A function descriptor has been resolved but PC is still in the |
| 499 | STT_GNU_IFUNC resolver body (such as because inferior does not |
| 500 | run to be able to call it). */ |
| 501 | |
| 502 | type = mst_text_gnu_ifunc; |
| 503 | } |
| 504 | else |
| 505 | type = mst_text; |
| 506 | section = NULL; |
| 507 | addr = pc; |
| 508 | } |
| 509 | |
| 510 | if (overlay_debugging) |
| 511 | addr = symbol_overlayed_address (addr, section); |
| 512 | |
| 513 | write_exp_elt_opcode (OP_LONG); |
| 514 | /* Let's make the type big enough to hold a 64-bit address. */ |
| 515 | write_exp_elt_type (objfile_type (objfile)->builtin_core_addr); |
| 516 | write_exp_elt_longcst ((LONGEST) addr); |
| 517 | write_exp_elt_opcode (OP_LONG); |
| 518 | |
| 519 | if (section && section->the_bfd_section->flags & SEC_THREAD_LOCAL) |
| 520 | { |
| 521 | write_exp_elt_opcode (UNOP_MEMVAL_TLS); |
| 522 | write_exp_elt_objfile (objfile); |
| 523 | write_exp_elt_type (objfile_type (objfile)->nodebug_tls_symbol); |
| 524 | write_exp_elt_opcode (UNOP_MEMVAL_TLS); |
| 525 | return; |
| 526 | } |
| 527 | |
| 528 | write_exp_elt_opcode (UNOP_MEMVAL); |
| 529 | switch (type) |
| 530 | { |
| 531 | case mst_text: |
| 532 | case mst_file_text: |
| 533 | case mst_solib_trampoline: |
| 534 | write_exp_elt_type (objfile_type (objfile)->nodebug_text_symbol); |
| 535 | break; |
| 536 | |
| 537 | case mst_text_gnu_ifunc: |
| 538 | write_exp_elt_type (objfile_type (objfile) |
| 539 | ->nodebug_text_gnu_ifunc_symbol); |
| 540 | break; |
| 541 | |
| 542 | case mst_data: |
| 543 | case mst_file_data: |
| 544 | case mst_bss: |
| 545 | case mst_file_bss: |
| 546 | write_exp_elt_type (objfile_type (objfile)->nodebug_data_symbol); |
| 547 | break; |
| 548 | |
| 549 | case mst_slot_got_plt: |
| 550 | write_exp_elt_type (objfile_type (objfile)->nodebug_got_plt_symbol); |
| 551 | break; |
| 552 | |
| 553 | default: |
| 554 | write_exp_elt_type (objfile_type (objfile)->nodebug_unknown_symbol); |
| 555 | break; |
| 556 | } |
| 557 | write_exp_elt_opcode (UNOP_MEMVAL); |
| 558 | } |
| 559 | |
| 560 | /* Mark the current index as the starting location of a structure |
| 561 | expression. This is used when completing on field names. */ |
| 562 | |
| 563 | void |
| 564 | mark_struct_expression (void) |
| 565 | { |
| 566 | expout_last_struct = expout_ptr; |
| 567 | } |
| 568 | |
| 569 | \f |
| 570 | /* Recognize tokens that start with '$'. These include: |
| 571 | |
| 572 | $regname A native register name or a "standard |
| 573 | register name". |
| 574 | |
| 575 | $variable A convenience variable with a name chosen |
| 576 | by the user. |
| 577 | |
| 578 | $digits Value history with index <digits>, starting |
| 579 | from the first value which has index 1. |
| 580 | |
| 581 | $$digits Value history with index <digits> relative |
| 582 | to the last value. I.e. $$0 is the last |
| 583 | value, $$1 is the one previous to that, $$2 |
| 584 | is the one previous to $$1, etc. |
| 585 | |
| 586 | $ | $0 | $$0 The last value in the value history. |
| 587 | |
| 588 | $$ An abbreviation for the second to the last |
| 589 | value in the value history, I.e. $$1 */ |
| 590 | |
| 591 | void |
| 592 | write_dollar_variable (struct stoken str) |
| 593 | { |
| 594 | struct symbol *sym = NULL; |
| 595 | struct minimal_symbol *msym = NULL; |
| 596 | struct internalvar *isym = NULL; |
| 597 | |
| 598 | /* Handle the tokens $digits; also $ (short for $0) and $$ (short for $$1) |
| 599 | and $$digits (equivalent to $<-digits> if you could type that). */ |
| 600 | |
| 601 | int negate = 0; |
| 602 | int i = 1; |
| 603 | /* Double dollar means negate the number and add -1 as well. |
| 604 | Thus $$ alone means -1. */ |
| 605 | if (str.length >= 2 && str.ptr[1] == '$') |
| 606 | { |
| 607 | negate = 1; |
| 608 | i = 2; |
| 609 | } |
| 610 | if (i == str.length) |
| 611 | { |
| 612 | /* Just dollars (one or two). */ |
| 613 | i = -negate; |
| 614 | goto handle_last; |
| 615 | } |
| 616 | /* Is the rest of the token digits? */ |
| 617 | for (; i < str.length; i++) |
| 618 | if (!(str.ptr[i] >= '0' && str.ptr[i] <= '9')) |
| 619 | break; |
| 620 | if (i == str.length) |
| 621 | { |
| 622 | i = atoi (str.ptr + 1 + negate); |
| 623 | if (negate) |
| 624 | i = -i; |
| 625 | goto handle_last; |
| 626 | } |
| 627 | |
| 628 | /* Handle tokens that refer to machine registers: |
| 629 | $ followed by a register name. */ |
| 630 | i = user_reg_map_name_to_regnum (parse_gdbarch, |
| 631 | str.ptr + 1, str.length - 1); |
| 632 | if (i >= 0) |
| 633 | goto handle_register; |
| 634 | |
| 635 | /* Any names starting with $ are probably debugger internal variables. */ |
| 636 | |
| 637 | isym = lookup_only_internalvar (copy_name (str) + 1); |
| 638 | if (isym) |
| 639 | { |
| 640 | write_exp_elt_opcode (OP_INTERNALVAR); |
| 641 | write_exp_elt_intern (isym); |
| 642 | write_exp_elt_opcode (OP_INTERNALVAR); |
| 643 | return; |
| 644 | } |
| 645 | |
| 646 | /* On some systems, such as HP-UX and hppa-linux, certain system routines |
| 647 | have names beginning with $ or $$. Check for those, first. */ |
| 648 | |
| 649 | sym = lookup_symbol (copy_name (str), (struct block *) NULL, |
| 650 | VAR_DOMAIN, (int *) NULL); |
| 651 | if (sym) |
| 652 | { |
| 653 | write_exp_elt_opcode (OP_VAR_VALUE); |
| 654 | write_exp_elt_block (block_found); /* set by lookup_symbol */ |
| 655 | write_exp_elt_sym (sym); |
| 656 | write_exp_elt_opcode (OP_VAR_VALUE); |
| 657 | return; |
| 658 | } |
| 659 | msym = lookup_minimal_symbol (copy_name (str), NULL, NULL); |
| 660 | if (msym) |
| 661 | { |
| 662 | write_exp_msymbol (msym); |
| 663 | return; |
| 664 | } |
| 665 | |
| 666 | /* Any other names are assumed to be debugger internal variables. */ |
| 667 | |
| 668 | write_exp_elt_opcode (OP_INTERNALVAR); |
| 669 | write_exp_elt_intern (create_internalvar (copy_name (str) + 1)); |
| 670 | write_exp_elt_opcode (OP_INTERNALVAR); |
| 671 | return; |
| 672 | handle_last: |
| 673 | write_exp_elt_opcode (OP_LAST); |
| 674 | write_exp_elt_longcst ((LONGEST) i); |
| 675 | write_exp_elt_opcode (OP_LAST); |
| 676 | return; |
| 677 | handle_register: |
| 678 | write_exp_elt_opcode (OP_REGISTER); |
| 679 | str.length--; |
| 680 | str.ptr++; |
| 681 | write_exp_string (str); |
| 682 | write_exp_elt_opcode (OP_REGISTER); |
| 683 | return; |
| 684 | } |
| 685 | |
| 686 | |
| 687 | char * |
| 688 | find_template_name_end (char *p) |
| 689 | { |
| 690 | int depth = 1; |
| 691 | int just_seen_right = 0; |
| 692 | int just_seen_colon = 0; |
| 693 | int just_seen_space = 0; |
| 694 | |
| 695 | if (!p || (*p != '<')) |
| 696 | return 0; |
| 697 | |
| 698 | while (*++p) |
| 699 | { |
| 700 | switch (*p) |
| 701 | { |
| 702 | case '\'': |
| 703 | case '\"': |
| 704 | case '{': |
| 705 | case '}': |
| 706 | /* In future, may want to allow these?? */ |
| 707 | return 0; |
| 708 | case '<': |
| 709 | depth++; /* start nested template */ |
| 710 | if (just_seen_colon || just_seen_right || just_seen_space) |
| 711 | return 0; /* but not after : or :: or > or space */ |
| 712 | break; |
| 713 | case '>': |
| 714 | if (just_seen_colon || just_seen_right) |
| 715 | return 0; /* end a (nested?) template */ |
| 716 | just_seen_right = 1; /* but not after : or :: */ |
| 717 | if (--depth == 0) /* also disallow >>, insist on > > */ |
| 718 | return ++p; /* if outermost ended, return */ |
| 719 | break; |
| 720 | case ':': |
| 721 | if (just_seen_space || (just_seen_colon > 1)) |
| 722 | return 0; /* nested class spec coming up */ |
| 723 | just_seen_colon++; /* we allow :: but not :::: */ |
| 724 | break; |
| 725 | case ' ': |
| 726 | break; |
| 727 | default: |
| 728 | if (!((*p >= 'a' && *p <= 'z') || /* allow token chars */ |
| 729 | (*p >= 'A' && *p <= 'Z') || |
| 730 | (*p >= '0' && *p <= '9') || |
| 731 | (*p == '_') || (*p == ',') || /* commas for template args */ |
| 732 | (*p == '&') || (*p == '*') || /* pointer and ref types */ |
| 733 | (*p == '(') || (*p == ')') || /* function types */ |
| 734 | (*p == '[') || (*p == ']'))) /* array types */ |
| 735 | return 0; |
| 736 | } |
| 737 | if (*p != ' ') |
| 738 | just_seen_space = 0; |
| 739 | if (*p != ':') |
| 740 | just_seen_colon = 0; |
| 741 | if (*p != '>') |
| 742 | just_seen_right = 0; |
| 743 | } |
| 744 | return 0; |
| 745 | } |
| 746 | \f |
| 747 | |
| 748 | |
| 749 | /* Return a null-terminated temporary copy of the name |
| 750 | of a string token. */ |
| 751 | |
| 752 | char * |
| 753 | copy_name (struct stoken token) |
| 754 | { |
| 755 | /* Make sure there's enough space for the token. */ |
| 756 | if (namecopy_size < token.length + 1) |
| 757 | { |
| 758 | namecopy_size = token.length + 1; |
| 759 | namecopy = xrealloc (namecopy, token.length + 1); |
| 760 | } |
| 761 | |
| 762 | memcpy (namecopy, token.ptr, token.length); |
| 763 | namecopy[token.length] = 0; |
| 764 | |
| 765 | return namecopy; |
| 766 | } |
| 767 | \f |
| 768 | /* Reverse an expression from suffix form (in which it is constructed) |
| 769 | to prefix form (in which we can conveniently print or execute it). |
| 770 | Ordinarily this always returns -1. However, if EXPOUT_LAST_STRUCT |
| 771 | is not -1 (i.e., we are trying to complete a field name), it will |
| 772 | return the index of the subexpression which is the left-hand-side |
| 773 | of the struct operation at EXPOUT_LAST_STRUCT. */ |
| 774 | |
| 775 | static int |
| 776 | prefixify_expression (struct expression *expr) |
| 777 | { |
| 778 | int len = sizeof (struct expression) + EXP_ELEM_TO_BYTES (expr->nelts); |
| 779 | struct expression *temp; |
| 780 | int inpos = expr->nelts, outpos = 0; |
| 781 | |
| 782 | temp = (struct expression *) alloca (len); |
| 783 | |
| 784 | /* Copy the original expression into temp. */ |
| 785 | memcpy (temp, expr, len); |
| 786 | |
| 787 | return prefixify_subexp (temp, expr, inpos, outpos); |
| 788 | } |
| 789 | |
| 790 | /* Return the number of exp_elements in the postfix subexpression |
| 791 | of EXPR whose operator is at index ENDPOS - 1 in EXPR. */ |
| 792 | |
| 793 | int |
| 794 | length_of_subexp (struct expression *expr, int endpos) |
| 795 | { |
| 796 | int oplen, args; |
| 797 | |
| 798 | operator_length (expr, endpos, &oplen, &args); |
| 799 | |
| 800 | while (args > 0) |
| 801 | { |
| 802 | oplen += length_of_subexp (expr, endpos - oplen); |
| 803 | args--; |
| 804 | } |
| 805 | |
| 806 | return oplen; |
| 807 | } |
| 808 | |
| 809 | /* Sets *OPLENP to the length of the operator whose (last) index is |
| 810 | ENDPOS - 1 in EXPR, and sets *ARGSP to the number of arguments that |
| 811 | operator takes. */ |
| 812 | |
| 813 | void |
| 814 | operator_length (const struct expression *expr, int endpos, int *oplenp, |
| 815 | int *argsp) |
| 816 | { |
| 817 | expr->language_defn->la_exp_desc->operator_length (expr, endpos, |
| 818 | oplenp, argsp); |
| 819 | } |
| 820 | |
| 821 | /* Default value for operator_length in exp_descriptor vectors. */ |
| 822 | |
| 823 | void |
| 824 | operator_length_standard (const struct expression *expr, int endpos, |
| 825 | int *oplenp, int *argsp) |
| 826 | { |
| 827 | int oplen = 1; |
| 828 | int args = 0; |
| 829 | enum f90_range_type range_type; |
| 830 | int i; |
| 831 | |
| 832 | if (endpos < 1) |
| 833 | error (_("?error in operator_length_standard")); |
| 834 | |
| 835 | i = (int) expr->elts[endpos - 1].opcode; |
| 836 | |
| 837 | switch (i) |
| 838 | { |
| 839 | /* C++ */ |
| 840 | case OP_SCOPE: |
| 841 | oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
| 842 | oplen = 5 + BYTES_TO_EXP_ELEM (oplen + 1); |
| 843 | break; |
| 844 | |
| 845 | case OP_LONG: |
| 846 | case OP_DOUBLE: |
| 847 | case OP_DECFLOAT: |
| 848 | case OP_VAR_VALUE: |
| 849 | oplen = 4; |
| 850 | break; |
| 851 | |
| 852 | case OP_TYPE: |
| 853 | case OP_BOOL: |
| 854 | case OP_LAST: |
| 855 | case OP_INTERNALVAR: |
| 856 | oplen = 3; |
| 857 | break; |
| 858 | |
| 859 | case OP_COMPLEX: |
| 860 | oplen = 3; |
| 861 | args = 2; |
| 862 | break; |
| 863 | |
| 864 | case OP_FUNCALL: |
| 865 | case OP_F77_UNDETERMINED_ARGLIST: |
| 866 | oplen = 3; |
| 867 | args = 1 + longest_to_int (expr->elts[endpos - 2].longconst); |
| 868 | break; |
| 869 | |
| 870 | case TYPE_INSTANCE: |
| 871 | oplen = 4 + longest_to_int (expr->elts[endpos - 2].longconst); |
| 872 | args = 1; |
| 873 | break; |
| 874 | |
| 875 | case OP_OBJC_MSGCALL: /* Objective C message (method) call. */ |
| 876 | oplen = 4; |
| 877 | args = 1 + longest_to_int (expr->elts[endpos - 2].longconst); |
| 878 | break; |
| 879 | |
| 880 | case UNOP_MAX: |
| 881 | case UNOP_MIN: |
| 882 | oplen = 3; |
| 883 | break; |
| 884 | |
| 885 | case BINOP_VAL: |
| 886 | case UNOP_CAST: |
| 887 | case UNOP_DYNAMIC_CAST: |
| 888 | case UNOP_REINTERPRET_CAST: |
| 889 | case UNOP_MEMVAL: |
| 890 | oplen = 3; |
| 891 | args = 1; |
| 892 | break; |
| 893 | |
| 894 | case UNOP_MEMVAL_TLS: |
| 895 | oplen = 4; |
| 896 | args = 1; |
| 897 | break; |
| 898 | |
| 899 | case UNOP_ABS: |
| 900 | case UNOP_CAP: |
| 901 | case UNOP_CHR: |
| 902 | case UNOP_FLOAT: |
| 903 | case UNOP_HIGH: |
| 904 | case UNOP_ODD: |
| 905 | case UNOP_ORD: |
| 906 | case UNOP_TRUNC: |
| 907 | oplen = 1; |
| 908 | args = 1; |
| 909 | break; |
| 910 | |
| 911 | case OP_ADL_FUNC: |
| 912 | oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
| 913 | oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1); |
| 914 | oplen++; |
| 915 | oplen++; |
| 916 | break; |
| 917 | |
| 918 | case OP_LABELED: |
| 919 | case STRUCTOP_STRUCT: |
| 920 | case STRUCTOP_PTR: |
| 921 | args = 1; |
| 922 | /* fall through */ |
| 923 | case OP_REGISTER: |
| 924 | case OP_M2_STRING: |
| 925 | case OP_STRING: |
| 926 | case OP_OBJC_NSSTRING: /* Objective C Foundation Class |
| 927 | NSString constant. */ |
| 928 | case OP_OBJC_SELECTOR: /* Objective C "@selector" pseudo-op. */ |
| 929 | case OP_NAME: |
| 930 | oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
| 931 | oplen = 4 + BYTES_TO_EXP_ELEM (oplen + 1); |
| 932 | break; |
| 933 | |
| 934 | case OP_BITSTRING: |
| 935 | oplen = longest_to_int (expr->elts[endpos - 2].longconst); |
| 936 | oplen = (oplen + HOST_CHAR_BIT - 1) / HOST_CHAR_BIT; |
| 937 | oplen = 4 + BYTES_TO_EXP_ELEM (oplen); |
| 938 | break; |
| 939 | |
| 940 | case OP_ARRAY: |
| 941 | oplen = 4; |
| 942 | args = longest_to_int (expr->elts[endpos - 2].longconst); |
| 943 | args -= longest_to_int (expr->elts[endpos - 3].longconst); |
| 944 | args += 1; |
| 945 | break; |
| 946 | |
| 947 | case TERNOP_COND: |
| 948 | case TERNOP_SLICE: |
| 949 | case TERNOP_SLICE_COUNT: |
| 950 | args = 3; |
| 951 | break; |
| 952 | |
| 953 | /* Modula-2 */ |
| 954 | case MULTI_SUBSCRIPT: |
| 955 | oplen = 3; |
| 956 | args = 1 + longest_to_int (expr->elts[endpos - 2].longconst); |
| 957 | break; |
| 958 | |
| 959 | case BINOP_ASSIGN_MODIFY: |
| 960 | oplen = 3; |
| 961 | args = 2; |
| 962 | break; |
| 963 | |
| 964 | /* C++ */ |
| 965 | case OP_THIS: |
| 966 | case OP_OBJC_SELF: |
| 967 | oplen = 2; |
| 968 | break; |
| 969 | |
| 970 | case OP_F90_RANGE: |
| 971 | oplen = 3; |
| 972 | |
| 973 | range_type = longest_to_int (expr->elts[endpos - 2].longconst); |
| 974 | switch (range_type) |
| 975 | { |
| 976 | case LOW_BOUND_DEFAULT: |
| 977 | case HIGH_BOUND_DEFAULT: |
| 978 | args = 1; |
| 979 | break; |
| 980 | case BOTH_BOUND_DEFAULT: |
| 981 | args = 0; |
| 982 | break; |
| 983 | case NONE_BOUND_DEFAULT: |
| 984 | args = 2; |
| 985 | break; |
| 986 | } |
| 987 | |
| 988 | break; |
| 989 | |
| 990 | default: |
| 991 | args = 1 + (i < (int) BINOP_END); |
| 992 | } |
| 993 | |
| 994 | *oplenp = oplen; |
| 995 | *argsp = args; |
| 996 | } |
| 997 | |
| 998 | /* Copy the subexpression ending just before index INEND in INEXPR |
| 999 | into OUTEXPR, starting at index OUTBEG. |
| 1000 | In the process, convert it from suffix to prefix form. |
| 1001 | If EXPOUT_LAST_STRUCT is -1, then this function always returns -1. |
| 1002 | Otherwise, it returns the index of the subexpression which is the |
| 1003 | left-hand-side of the expression at EXPOUT_LAST_STRUCT. */ |
| 1004 | |
| 1005 | static int |
| 1006 | prefixify_subexp (struct expression *inexpr, |
| 1007 | struct expression *outexpr, int inend, int outbeg) |
| 1008 | { |
| 1009 | int oplen; |
| 1010 | int args; |
| 1011 | int i; |
| 1012 | int *arglens; |
| 1013 | int result = -1; |
| 1014 | |
| 1015 | operator_length (inexpr, inend, &oplen, &args); |
| 1016 | |
| 1017 | /* Copy the final operator itself, from the end of the input |
| 1018 | to the beginning of the output. */ |
| 1019 | inend -= oplen; |
| 1020 | memcpy (&outexpr->elts[outbeg], &inexpr->elts[inend], |
| 1021 | EXP_ELEM_TO_BYTES (oplen)); |
| 1022 | outbeg += oplen; |
| 1023 | |
| 1024 | if (expout_last_struct == inend) |
| 1025 | result = outbeg - oplen; |
| 1026 | |
| 1027 | /* Find the lengths of the arg subexpressions. */ |
| 1028 | arglens = (int *) alloca (args * sizeof (int)); |
| 1029 | for (i = args - 1; i >= 0; i--) |
| 1030 | { |
| 1031 | oplen = length_of_subexp (inexpr, inend); |
| 1032 | arglens[i] = oplen; |
| 1033 | inend -= oplen; |
| 1034 | } |
| 1035 | |
| 1036 | /* Now copy each subexpression, preserving the order of |
| 1037 | the subexpressions, but prefixifying each one. |
| 1038 | In this loop, inend starts at the beginning of |
| 1039 | the expression this level is working on |
| 1040 | and marches forward over the arguments. |
| 1041 | outbeg does similarly in the output. */ |
| 1042 | for (i = 0; i < args; i++) |
| 1043 | { |
| 1044 | int r; |
| 1045 | |
| 1046 | oplen = arglens[i]; |
| 1047 | inend += oplen; |
| 1048 | r = prefixify_subexp (inexpr, outexpr, inend, outbeg); |
| 1049 | if (r != -1) |
| 1050 | { |
| 1051 | /* Return immediately. We probably have only parsed a |
| 1052 | partial expression, so we don't want to try to reverse |
| 1053 | the other operands. */ |
| 1054 | return r; |
| 1055 | } |
| 1056 | outbeg += oplen; |
| 1057 | } |
| 1058 | |
| 1059 | return result; |
| 1060 | } |
| 1061 | \f |
| 1062 | /* Read an expression from the string *STRINGPTR points to, |
| 1063 | parse it, and return a pointer to a struct expression that we malloc. |
| 1064 | Use block BLOCK as the lexical context for variable names; |
| 1065 | if BLOCK is zero, use the block of the selected stack frame. |
| 1066 | Meanwhile, advance *STRINGPTR to point after the expression, |
| 1067 | at the first nonwhite character that is not part of the expression |
| 1068 | (possibly a null character). |
| 1069 | |
| 1070 | If COMMA is nonzero, stop if a comma is reached. */ |
| 1071 | |
| 1072 | struct expression * |
| 1073 | parse_exp_1 (char **stringptr, struct block *block, int comma) |
| 1074 | { |
| 1075 | return parse_exp_in_context (stringptr, block, comma, 0, NULL); |
| 1076 | } |
| 1077 | |
| 1078 | /* As for parse_exp_1, except that if VOID_CONTEXT_P, then |
| 1079 | no value is expected from the expression. |
| 1080 | OUT_SUBEXP is set when attempting to complete a field name; in this |
| 1081 | case it is set to the index of the subexpression on the |
| 1082 | left-hand-side of the struct op. If not doing such completion, it |
| 1083 | is left untouched. */ |
| 1084 | |
| 1085 | static struct expression * |
| 1086 | parse_exp_in_context (char **stringptr, struct block *block, int comma, |
| 1087 | int void_context_p, int *out_subexp) |
| 1088 | { |
| 1089 | volatile struct gdb_exception except; |
| 1090 | struct cleanup *old_chain; |
| 1091 | const struct language_defn *lang = NULL; |
| 1092 | int subexp; |
| 1093 | |
| 1094 | lexptr = *stringptr; |
| 1095 | prev_lexptr = NULL; |
| 1096 | |
| 1097 | paren_depth = 0; |
| 1098 | type_stack_depth = 0; |
| 1099 | expout_last_struct = -1; |
| 1100 | |
| 1101 | comma_terminates = comma; |
| 1102 | |
| 1103 | if (lexptr == 0 || *lexptr == 0) |
| 1104 | error_no_arg (_("expression to compute")); |
| 1105 | |
| 1106 | old_chain = make_cleanup (free_funcalls, 0 /*ignore*/); |
| 1107 | funcall_chain = 0; |
| 1108 | |
| 1109 | expression_context_block = block; |
| 1110 | |
| 1111 | /* If no context specified, try using the current frame, if any. */ |
| 1112 | if (!expression_context_block) |
| 1113 | expression_context_block = get_selected_block (&expression_context_pc); |
| 1114 | else |
| 1115 | expression_context_pc = BLOCK_START (expression_context_block); |
| 1116 | |
| 1117 | /* Fall back to using the current source static context, if any. */ |
| 1118 | |
| 1119 | if (!expression_context_block) |
| 1120 | { |
| 1121 | struct symtab_and_line cursal = get_current_source_symtab_and_line (); |
| 1122 | if (cursal.symtab) |
| 1123 | expression_context_block |
| 1124 | = BLOCKVECTOR_BLOCK (BLOCKVECTOR (cursal.symtab), STATIC_BLOCK); |
| 1125 | if (expression_context_block) |
| 1126 | expression_context_pc = BLOCK_START (expression_context_block); |
| 1127 | } |
| 1128 | |
| 1129 | if (language_mode == language_mode_auto && block != NULL) |
| 1130 | { |
| 1131 | /* Find the language associated to the given context block. |
| 1132 | Default to the current language if it can not be determined. |
| 1133 | |
| 1134 | Note that using the language corresponding to the current frame |
| 1135 | can sometimes give unexpected results. For instance, this |
| 1136 | routine is often called several times during the inferior |
| 1137 | startup phase to re-parse breakpoint expressions after |
| 1138 | a new shared library has been loaded. The language associated |
| 1139 | to the current frame at this moment is not relevant for |
| 1140 | the breakpoint. Using it would therefore be silly, so it seems |
| 1141 | better to rely on the current language rather than relying on |
| 1142 | the current frame language to parse the expression. That's why |
| 1143 | we do the following language detection only if the context block |
| 1144 | has been specifically provided. */ |
| 1145 | struct symbol *func = block_linkage_function (block); |
| 1146 | |
| 1147 | if (func != NULL) |
| 1148 | lang = language_def (SYMBOL_LANGUAGE (func)); |
| 1149 | if (lang == NULL || lang->la_language == language_unknown) |
| 1150 | lang = current_language; |
| 1151 | } |
| 1152 | else |
| 1153 | lang = current_language; |
| 1154 | |
| 1155 | expout_size = 10; |
| 1156 | expout_ptr = 0; |
| 1157 | expout = (struct expression *) |
| 1158 | xmalloc (sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_size)); |
| 1159 | expout->language_defn = lang; |
| 1160 | expout->gdbarch = get_current_arch (); |
| 1161 | |
| 1162 | TRY_CATCH (except, RETURN_MASK_ALL) |
| 1163 | { |
| 1164 | if (lang->la_parser ()) |
| 1165 | lang->la_error (NULL); |
| 1166 | } |
| 1167 | if (except.reason < 0) |
| 1168 | { |
| 1169 | if (! in_parse_field) |
| 1170 | { |
| 1171 | xfree (expout); |
| 1172 | throw_exception (except); |
| 1173 | } |
| 1174 | } |
| 1175 | |
| 1176 | discard_cleanups (old_chain); |
| 1177 | |
| 1178 | /* Record the actual number of expression elements, and then |
| 1179 | reallocate the expression memory so that we free up any |
| 1180 | excess elements. */ |
| 1181 | |
| 1182 | expout->nelts = expout_ptr; |
| 1183 | expout = (struct expression *) |
| 1184 | xrealloc ((char *) expout, |
| 1185 | sizeof (struct expression) + EXP_ELEM_TO_BYTES (expout_ptr)); |
| 1186 | |
| 1187 | /* Convert expression from postfix form as generated by yacc |
| 1188 | parser, to a prefix form. */ |
| 1189 | |
| 1190 | if (expressiondebug) |
| 1191 | dump_raw_expression (expout, gdb_stdlog, |
| 1192 | "before conversion to prefix form"); |
| 1193 | |
| 1194 | subexp = prefixify_expression (expout); |
| 1195 | if (out_subexp) |
| 1196 | *out_subexp = subexp; |
| 1197 | |
| 1198 | lang->la_post_parser (&expout, void_context_p); |
| 1199 | |
| 1200 | if (expressiondebug) |
| 1201 | dump_prefix_expression (expout, gdb_stdlog); |
| 1202 | |
| 1203 | *stringptr = lexptr; |
| 1204 | return expout; |
| 1205 | } |
| 1206 | |
| 1207 | /* Parse STRING as an expression, and complain if this fails |
| 1208 | to use up all of the contents of STRING. */ |
| 1209 | |
| 1210 | struct expression * |
| 1211 | parse_expression (char *string) |
| 1212 | { |
| 1213 | struct expression *exp; |
| 1214 | |
| 1215 | exp = parse_exp_1 (&string, 0, 0); |
| 1216 | if (*string) |
| 1217 | error (_("Junk after end of expression.")); |
| 1218 | return exp; |
| 1219 | } |
| 1220 | |
| 1221 | /* Parse STRING as an expression. If parsing ends in the middle of a |
| 1222 | field reference, return the type of the left-hand-side of the |
| 1223 | reference; furthermore, if the parsing ends in the field name, |
| 1224 | return the field name in *NAME. If the parsing ends in the middle |
| 1225 | of a field reference, but the reference is somehow invalid, throw |
| 1226 | an exception. In all other cases, return NULL. Returned non-NULL |
| 1227 | *NAME must be freed by the caller. */ |
| 1228 | |
| 1229 | struct type * |
| 1230 | parse_field_expression (char *string, char **name) |
| 1231 | { |
| 1232 | struct expression *exp = NULL; |
| 1233 | struct value *val; |
| 1234 | int subexp; |
| 1235 | volatile struct gdb_exception except; |
| 1236 | |
| 1237 | TRY_CATCH (except, RETURN_MASK_ERROR) |
| 1238 | { |
| 1239 | in_parse_field = 1; |
| 1240 | exp = parse_exp_in_context (&string, 0, 0, 0, &subexp); |
| 1241 | } |
| 1242 | in_parse_field = 0; |
| 1243 | if (except.reason < 0 || ! exp) |
| 1244 | return NULL; |
| 1245 | if (expout_last_struct == -1) |
| 1246 | { |
| 1247 | xfree (exp); |
| 1248 | return NULL; |
| 1249 | } |
| 1250 | |
| 1251 | *name = extract_field_op (exp, &subexp); |
| 1252 | if (!*name) |
| 1253 | { |
| 1254 | xfree (exp); |
| 1255 | return NULL; |
| 1256 | } |
| 1257 | |
| 1258 | /* This might throw an exception. If so, we want to let it |
| 1259 | propagate. */ |
| 1260 | val = evaluate_subexpression_type (exp, subexp); |
| 1261 | /* (*NAME) is a part of the EXP memory block freed below. */ |
| 1262 | *name = xstrdup (*name); |
| 1263 | xfree (exp); |
| 1264 | |
| 1265 | return value_type (val); |
| 1266 | } |
| 1267 | |
| 1268 | /* A post-parser that does nothing. */ |
| 1269 | |
| 1270 | void |
| 1271 | null_post_parser (struct expression **exp, int void_context_p) |
| 1272 | { |
| 1273 | } |
| 1274 | |
| 1275 | /* Parse floating point value P of length LEN. |
| 1276 | Return 0 (false) if invalid, 1 (true) if valid. |
| 1277 | The successfully parsed number is stored in D. |
| 1278 | *SUFFIX points to the suffix of the number in P. |
| 1279 | |
| 1280 | NOTE: This accepts the floating point syntax that sscanf accepts. */ |
| 1281 | |
| 1282 | int |
| 1283 | parse_float (const char *p, int len, DOUBLEST *d, const char **suffix) |
| 1284 | { |
| 1285 | char *copy; |
| 1286 | char *s; |
| 1287 | int n, num; |
| 1288 | |
| 1289 | copy = xmalloc (len + 1); |
| 1290 | memcpy (copy, p, len); |
| 1291 | copy[len] = 0; |
| 1292 | |
| 1293 | num = sscanf (copy, "%" DOUBLEST_SCAN_FORMAT "%n", d, &n); |
| 1294 | xfree (copy); |
| 1295 | |
| 1296 | /* The sscanf man page suggests not making any assumptions on the effect |
| 1297 | of %n on the result, so we don't. |
| 1298 | That is why we simply test num == 0. */ |
| 1299 | if (num == 0) |
| 1300 | return 0; |
| 1301 | |
| 1302 | *suffix = p + n; |
| 1303 | return 1; |
| 1304 | } |
| 1305 | |
| 1306 | /* Parse floating point value P of length LEN, using the C syntax for floats. |
| 1307 | Return 0 (false) if invalid, 1 (true) if valid. |
| 1308 | The successfully parsed number is stored in *D. |
| 1309 | Its type is taken from builtin_type (gdbarch) and is stored in *T. */ |
| 1310 | |
| 1311 | int |
| 1312 | parse_c_float (struct gdbarch *gdbarch, const char *p, int len, |
| 1313 | DOUBLEST *d, struct type **t) |
| 1314 | { |
| 1315 | const char *suffix; |
| 1316 | int suffix_len; |
| 1317 | const struct builtin_type *builtin_types = builtin_type (gdbarch); |
| 1318 | |
| 1319 | if (! parse_float (p, len, d, &suffix)) |
| 1320 | return 0; |
| 1321 | |
| 1322 | suffix_len = p + len - suffix; |
| 1323 | |
| 1324 | if (suffix_len == 0) |
| 1325 | *t = builtin_types->builtin_double; |
| 1326 | else if (suffix_len == 1) |
| 1327 | { |
| 1328 | /* Handle suffixes: 'f' for float, 'l' for long double. */ |
| 1329 | if (tolower (*suffix) == 'f') |
| 1330 | *t = builtin_types->builtin_float; |
| 1331 | else if (tolower (*suffix) == 'l') |
| 1332 | *t = builtin_types->builtin_long_double; |
| 1333 | else |
| 1334 | return 0; |
| 1335 | } |
| 1336 | else |
| 1337 | return 0; |
| 1338 | |
| 1339 | return 1; |
| 1340 | } |
| 1341 | \f |
| 1342 | /* Stuff for maintaining a stack of types. Currently just used by C, but |
| 1343 | probably useful for any language which declares its types "backwards". */ |
| 1344 | |
| 1345 | static void |
| 1346 | check_type_stack_depth (void) |
| 1347 | { |
| 1348 | if (type_stack_depth == type_stack_size) |
| 1349 | { |
| 1350 | type_stack_size *= 2; |
| 1351 | type_stack = (union type_stack_elt *) |
| 1352 | xrealloc ((char *) type_stack, type_stack_size * sizeof (*type_stack)); |
| 1353 | } |
| 1354 | } |
| 1355 | |
| 1356 | void |
| 1357 | push_type (enum type_pieces tp) |
| 1358 | { |
| 1359 | check_type_stack_depth (); |
| 1360 | type_stack[type_stack_depth++].piece = tp; |
| 1361 | } |
| 1362 | |
| 1363 | void |
| 1364 | push_type_int (int n) |
| 1365 | { |
| 1366 | check_type_stack_depth (); |
| 1367 | type_stack[type_stack_depth++].int_val = n; |
| 1368 | } |
| 1369 | |
| 1370 | void |
| 1371 | push_type_address_space (char *string) |
| 1372 | { |
| 1373 | push_type_int (address_space_name_to_int (parse_gdbarch, string)); |
| 1374 | } |
| 1375 | |
| 1376 | enum type_pieces |
| 1377 | pop_type (void) |
| 1378 | { |
| 1379 | if (type_stack_depth) |
| 1380 | return type_stack[--type_stack_depth].piece; |
| 1381 | return tp_end; |
| 1382 | } |
| 1383 | |
| 1384 | int |
| 1385 | pop_type_int (void) |
| 1386 | { |
| 1387 | if (type_stack_depth) |
| 1388 | return type_stack[--type_stack_depth].int_val; |
| 1389 | /* "Can't happen". */ |
| 1390 | return 0; |
| 1391 | } |
| 1392 | |
| 1393 | /* Pop the type stack and return the type which corresponds to FOLLOW_TYPE |
| 1394 | as modified by all the stuff on the stack. */ |
| 1395 | struct type * |
| 1396 | follow_types (struct type *follow_type) |
| 1397 | { |
| 1398 | int done = 0; |
| 1399 | int make_const = 0; |
| 1400 | int make_volatile = 0; |
| 1401 | int make_addr_space = 0; |
| 1402 | int array_size; |
| 1403 | |
| 1404 | while (!done) |
| 1405 | switch (pop_type ()) |
| 1406 | { |
| 1407 | case tp_end: |
| 1408 | done = 1; |
| 1409 | if (make_const) |
| 1410 | follow_type = make_cv_type (make_const, |
| 1411 | TYPE_VOLATILE (follow_type), |
| 1412 | follow_type, 0); |
| 1413 | if (make_volatile) |
| 1414 | follow_type = make_cv_type (TYPE_CONST (follow_type), |
| 1415 | make_volatile, |
| 1416 | follow_type, 0); |
| 1417 | if (make_addr_space) |
| 1418 | follow_type = make_type_with_address_space (follow_type, |
| 1419 | make_addr_space); |
| 1420 | make_const = make_volatile = 0; |
| 1421 | make_addr_space = 0; |
| 1422 | break; |
| 1423 | case tp_const: |
| 1424 | make_const = 1; |
| 1425 | break; |
| 1426 | case tp_volatile: |
| 1427 | make_volatile = 1; |
| 1428 | break; |
| 1429 | case tp_space_identifier: |
| 1430 | make_addr_space = pop_type_int (); |
| 1431 | break; |
| 1432 | case tp_pointer: |
| 1433 | follow_type = lookup_pointer_type (follow_type); |
| 1434 | if (make_const) |
| 1435 | follow_type = make_cv_type (make_const, |
| 1436 | TYPE_VOLATILE (follow_type), |
| 1437 | follow_type, 0); |
| 1438 | if (make_volatile) |
| 1439 | follow_type = make_cv_type (TYPE_CONST (follow_type), |
| 1440 | make_volatile, |
| 1441 | follow_type, 0); |
| 1442 | if (make_addr_space) |
| 1443 | follow_type = make_type_with_address_space (follow_type, |
| 1444 | make_addr_space); |
| 1445 | make_const = make_volatile = 0; |
| 1446 | make_addr_space = 0; |
| 1447 | break; |
| 1448 | case tp_reference: |
| 1449 | follow_type = lookup_reference_type (follow_type); |
| 1450 | if (make_const) |
| 1451 | follow_type = make_cv_type (make_const, |
| 1452 | TYPE_VOLATILE (follow_type), |
| 1453 | follow_type, 0); |
| 1454 | if (make_volatile) |
| 1455 | follow_type = make_cv_type (TYPE_CONST (follow_type), |
| 1456 | make_volatile, |
| 1457 | follow_type, 0); |
| 1458 | if (make_addr_space) |
| 1459 | follow_type = make_type_with_address_space (follow_type, |
| 1460 | make_addr_space); |
| 1461 | make_const = make_volatile = 0; |
| 1462 | make_addr_space = 0; |
| 1463 | break; |
| 1464 | case tp_array: |
| 1465 | array_size = pop_type_int (); |
| 1466 | /* FIXME-type-allocation: need a way to free this type when we are |
| 1467 | done with it. */ |
| 1468 | follow_type = |
| 1469 | lookup_array_range_type (follow_type, |
| 1470 | 0, array_size >= 0 ? array_size - 1 : 0); |
| 1471 | if (array_size < 0) |
| 1472 | TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (follow_type) = 1; |
| 1473 | break; |
| 1474 | case tp_function: |
| 1475 | /* FIXME-type-allocation: need a way to free this type when we are |
| 1476 | done with it. */ |
| 1477 | follow_type = lookup_function_type (follow_type); |
| 1478 | break; |
| 1479 | } |
| 1480 | return follow_type; |
| 1481 | } |
| 1482 | \f |
| 1483 | /* This function avoids direct calls to fprintf |
| 1484 | in the parser generated debug code. */ |
| 1485 | void |
| 1486 | parser_fprintf (FILE *x, const char *y, ...) |
| 1487 | { |
| 1488 | va_list args; |
| 1489 | |
| 1490 | va_start (args, y); |
| 1491 | if (x == stderr) |
| 1492 | vfprintf_unfiltered (gdb_stderr, y, args); |
| 1493 | else |
| 1494 | { |
| 1495 | fprintf_unfiltered (gdb_stderr, " Unknown FILE used.\n"); |
| 1496 | vfprintf_unfiltered (gdb_stderr, y, args); |
| 1497 | } |
| 1498 | va_end (args); |
| 1499 | } |
| 1500 | |
| 1501 | /* Implementation of the exp_descriptor method operator_check. */ |
| 1502 | |
| 1503 | int |
| 1504 | operator_check_standard (struct expression *exp, int pos, |
| 1505 | int (*objfile_func) (struct objfile *objfile, |
| 1506 | void *data), |
| 1507 | void *data) |
| 1508 | { |
| 1509 | const union exp_element *const elts = exp->elts; |
| 1510 | struct type *type = NULL; |
| 1511 | struct objfile *objfile = NULL; |
| 1512 | |
| 1513 | /* Extended operators should have been already handled by exp_descriptor |
| 1514 | iterate method of its specific language. */ |
| 1515 | gdb_assert (elts[pos].opcode < OP_EXTENDED0); |
| 1516 | |
| 1517 | /* Track the callers of write_exp_elt_type for this table. */ |
| 1518 | |
| 1519 | switch (elts[pos].opcode) |
| 1520 | { |
| 1521 | case BINOP_VAL: |
| 1522 | case OP_COMPLEX: |
| 1523 | case OP_DECFLOAT: |
| 1524 | case OP_DOUBLE: |
| 1525 | case OP_LONG: |
| 1526 | case OP_SCOPE: |
| 1527 | case OP_TYPE: |
| 1528 | case UNOP_CAST: |
| 1529 | case UNOP_DYNAMIC_CAST: |
| 1530 | case UNOP_REINTERPRET_CAST: |
| 1531 | case UNOP_MAX: |
| 1532 | case UNOP_MEMVAL: |
| 1533 | case UNOP_MIN: |
| 1534 | type = elts[pos + 1].type; |
| 1535 | break; |
| 1536 | |
| 1537 | case TYPE_INSTANCE: |
| 1538 | { |
| 1539 | LONGEST arg, nargs = elts[pos + 1].longconst; |
| 1540 | |
| 1541 | for (arg = 0; arg < nargs; arg++) |
| 1542 | { |
| 1543 | struct type *type = elts[pos + 2 + arg].type; |
| 1544 | struct objfile *objfile = TYPE_OBJFILE (type); |
| 1545 | |
| 1546 | if (objfile && (*objfile_func) (objfile, data)) |
| 1547 | return 1; |
| 1548 | } |
| 1549 | } |
| 1550 | break; |
| 1551 | |
| 1552 | case UNOP_MEMVAL_TLS: |
| 1553 | objfile = elts[pos + 1].objfile; |
| 1554 | type = elts[pos + 2].type; |
| 1555 | break; |
| 1556 | |
| 1557 | case OP_VAR_VALUE: |
| 1558 | { |
| 1559 | const struct block *const block = elts[pos + 1].block; |
| 1560 | const struct symbol *const symbol = elts[pos + 2].symbol; |
| 1561 | |
| 1562 | /* Check objfile where the variable itself is placed. |
| 1563 | SYMBOL_OBJ_SECTION (symbol) may be NULL. */ |
| 1564 | if ((*objfile_func) (SYMBOL_SYMTAB (symbol)->objfile, data)) |
| 1565 | return 1; |
| 1566 | |
| 1567 | /* Check objfile where is placed the code touching the variable. */ |
| 1568 | objfile = lookup_objfile_from_block (block); |
| 1569 | |
| 1570 | type = SYMBOL_TYPE (symbol); |
| 1571 | } |
| 1572 | break; |
| 1573 | } |
| 1574 | |
| 1575 | /* Invoke callbacks for TYPE and OBJFILE if they were set as non-NULL. */ |
| 1576 | |
| 1577 | if (type && TYPE_OBJFILE (type) |
| 1578 | && (*objfile_func) (TYPE_OBJFILE (type), data)) |
| 1579 | return 1; |
| 1580 | if (objfile && (*objfile_func) (objfile, data)) |
| 1581 | return 1; |
| 1582 | |
| 1583 | return 0; |
| 1584 | } |
| 1585 | |
| 1586 | /* Call OBJFILE_FUNC for any TYPE and OBJFILE found being referenced by EXP. |
| 1587 | The functions are never called with NULL OBJFILE. Functions get passed an |
| 1588 | arbitrary caller supplied DATA pointer. If any of the functions returns |
| 1589 | non-zero value then (any other) non-zero value is immediately returned to |
| 1590 | the caller. Otherwise zero is returned after iterating through whole EXP. |
| 1591 | */ |
| 1592 | |
| 1593 | static int |
| 1594 | exp_iterate (struct expression *exp, |
| 1595 | int (*objfile_func) (struct objfile *objfile, void *data), |
| 1596 | void *data) |
| 1597 | { |
| 1598 | int endpos; |
| 1599 | |
| 1600 | for (endpos = exp->nelts; endpos > 0; ) |
| 1601 | { |
| 1602 | int pos, args, oplen = 0; |
| 1603 | |
| 1604 | operator_length (exp, endpos, &oplen, &args); |
| 1605 | gdb_assert (oplen > 0); |
| 1606 | |
| 1607 | pos = endpos - oplen; |
| 1608 | if (exp->language_defn->la_exp_desc->operator_check (exp, pos, |
| 1609 | objfile_func, data)) |
| 1610 | return 1; |
| 1611 | |
| 1612 | endpos = pos; |
| 1613 | } |
| 1614 | |
| 1615 | return 0; |
| 1616 | } |
| 1617 | |
| 1618 | /* Helper for exp_uses_objfile. */ |
| 1619 | |
| 1620 | static int |
| 1621 | exp_uses_objfile_iter (struct objfile *exp_objfile, void *objfile_voidp) |
| 1622 | { |
| 1623 | struct objfile *objfile = objfile_voidp; |
| 1624 | |
| 1625 | if (exp_objfile->separate_debug_objfile_backlink) |
| 1626 | exp_objfile = exp_objfile->separate_debug_objfile_backlink; |
| 1627 | |
| 1628 | return exp_objfile == objfile; |
| 1629 | } |
| 1630 | |
| 1631 | /* Return 1 if EXP uses OBJFILE (and will become dangling when OBJFILE |
| 1632 | is unloaded), otherwise return 0. OBJFILE must not be a separate debug info |
| 1633 | file. */ |
| 1634 | |
| 1635 | int |
| 1636 | exp_uses_objfile (struct expression *exp, struct objfile *objfile) |
| 1637 | { |
| 1638 | gdb_assert (objfile->separate_debug_objfile_backlink == NULL); |
| 1639 | |
| 1640 | return exp_iterate (exp, exp_uses_objfile_iter, objfile); |
| 1641 | } |
| 1642 | |
| 1643 | void |
| 1644 | _initialize_parse (void) |
| 1645 | { |
| 1646 | type_stack_size = 80; |
| 1647 | type_stack_depth = 0; |
| 1648 | type_stack = (union type_stack_elt *) |
| 1649 | xmalloc (type_stack_size * sizeof (*type_stack)); |
| 1650 | |
| 1651 | add_setshow_zinteger_cmd ("expression", class_maintenance, |
| 1652 | &expressiondebug, |
| 1653 | _("Set expression debugging."), |
| 1654 | _("Show expression debugging."), |
| 1655 | _("When non-zero, the internal representation " |
| 1656 | "of expressions will be printed."), |
| 1657 | NULL, |
| 1658 | show_expressiondebug, |
| 1659 | &setdebuglist, &showdebuglist); |
| 1660 | add_setshow_boolean_cmd ("parser", class_maintenance, |
| 1661 | &parser_debug, |
| 1662 | _("Set parser debugging."), |
| 1663 | _("Show parser debugging."), |
| 1664 | _("When non-zero, expression parser " |
| 1665 | "tracing will be enabled."), |
| 1666 | NULL, |
| 1667 | show_parserdebug, |
| 1668 | &setdebuglist, &showdebuglist); |
| 1669 | } |