| 1 | /* Evaluate expressions for GDB. |
| 2 | Copyright 1986, 1987, 1989, 1991, 1992 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "symtab.h" |
| 22 | #include "gdbtypes.h" |
| 23 | #include "value.h" |
| 24 | #include "expression.h" |
| 25 | #include "target.h" |
| 26 | #include "frame.h" |
| 27 | #include "language.h" /* For CAST_IS_CONVERSION */ |
| 28 | |
| 29 | /* Values of NOSIDE argument to eval_subexp. */ |
| 30 | enum noside |
| 31 | { EVAL_NORMAL, |
| 32 | EVAL_SKIP, /* Only effect is to increment pos. */ |
| 33 | EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or |
| 34 | call any functions. The value |
| 35 | returned will have the correct |
| 36 | type, and will have an |
| 37 | approximately correct lvalue |
| 38 | type (inaccuracy: anything that is |
| 39 | listed as being in a register in |
| 40 | the function in which it was |
| 41 | declared will be lval_register). */ |
| 42 | }; |
| 43 | |
| 44 | /* Prototypes for local functions. */ |
| 45 | |
| 46 | static value |
| 47 | evaluate_subexp_for_sizeof PARAMS ((struct expression *, int *)); |
| 48 | |
| 49 | static value |
| 50 | evaluate_subexp_with_coercion PARAMS ((struct expression *, int *, |
| 51 | enum noside)); |
| 52 | |
| 53 | static value |
| 54 | evaluate_subexp_for_address PARAMS ((struct expression *, int *, |
| 55 | enum noside)); |
| 56 | |
| 57 | static value |
| 58 | evaluate_subexp PARAMS ((struct type *, struct expression *, int *, |
| 59 | enum noside)); |
| 60 | |
| 61 | \f |
| 62 | /* Parse the string EXP as a C expression, evaluate it, |
| 63 | and return the result as a number. */ |
| 64 | |
| 65 | CORE_ADDR |
| 66 | parse_and_eval_address (exp) |
| 67 | char *exp; |
| 68 | { |
| 69 | struct expression *expr = parse_expression (exp); |
| 70 | register CORE_ADDR addr; |
| 71 | register struct cleanup *old_chain = |
| 72 | make_cleanup (free_current_contents, &expr); |
| 73 | |
| 74 | addr = value_as_pointer (evaluate_expression (expr)); |
| 75 | do_cleanups (old_chain); |
| 76 | return addr; |
| 77 | } |
| 78 | |
| 79 | /* Like parse_and_eval_address but takes a pointer to a char * variable |
| 80 | and advanced that variable across the characters parsed. */ |
| 81 | |
| 82 | CORE_ADDR |
| 83 | parse_and_eval_address_1 (expptr) |
| 84 | char **expptr; |
| 85 | { |
| 86 | struct expression *expr = parse_exp_1 (expptr, (struct block *)0, 0); |
| 87 | register CORE_ADDR addr; |
| 88 | register struct cleanup *old_chain = |
| 89 | make_cleanup (free_current_contents, &expr); |
| 90 | |
| 91 | addr = value_as_pointer (evaluate_expression (expr)); |
| 92 | do_cleanups (old_chain); |
| 93 | return addr; |
| 94 | } |
| 95 | |
| 96 | value |
| 97 | parse_and_eval (exp) |
| 98 | char *exp; |
| 99 | { |
| 100 | struct expression *expr = parse_expression (exp); |
| 101 | register value val; |
| 102 | register struct cleanup *old_chain |
| 103 | = make_cleanup (free_current_contents, &expr); |
| 104 | |
| 105 | val = evaluate_expression (expr); |
| 106 | do_cleanups (old_chain); |
| 107 | return val; |
| 108 | } |
| 109 | |
| 110 | /* Parse up to a comma (or to a closeparen) |
| 111 | in the string EXPP as an expression, evaluate it, and return the value. |
| 112 | EXPP is advanced to point to the comma. */ |
| 113 | |
| 114 | value |
| 115 | parse_to_comma_and_eval (expp) |
| 116 | char **expp; |
| 117 | { |
| 118 | struct expression *expr = parse_exp_1 (expp, (struct block *) 0, 1); |
| 119 | register value val; |
| 120 | register struct cleanup *old_chain |
| 121 | = make_cleanup (free_current_contents, &expr); |
| 122 | |
| 123 | val = evaluate_expression (expr); |
| 124 | do_cleanups (old_chain); |
| 125 | return val; |
| 126 | } |
| 127 | \f |
| 128 | /* Evaluate an expression in internal prefix form |
| 129 | such as is constructed by parse.y. |
| 130 | |
| 131 | See expression.h for info on the format of an expression. */ |
| 132 | |
| 133 | static value evaluate_subexp (); |
| 134 | static value evaluate_subexp_for_address (); |
| 135 | static value evaluate_subexp_for_sizeof (); |
| 136 | static value evaluate_subexp_with_coercion (); |
| 137 | |
| 138 | value |
| 139 | evaluate_expression (exp) |
| 140 | struct expression *exp; |
| 141 | { |
| 142 | int pc = 0; |
| 143 | return evaluate_subexp (NULL_TYPE, exp, &pc, EVAL_NORMAL); |
| 144 | } |
| 145 | |
| 146 | /* Evaluate an expression, avoiding all memory references |
| 147 | and getting a value whose type alone is correct. */ |
| 148 | |
| 149 | value |
| 150 | evaluate_type (exp) |
| 151 | struct expression *exp; |
| 152 | { |
| 153 | int pc = 0; |
| 154 | return evaluate_subexp (NULL_TYPE, exp, &pc, EVAL_AVOID_SIDE_EFFECTS); |
| 155 | } |
| 156 | |
| 157 | static value |
| 158 | evaluate_subexp (expect_type, exp, pos, noside) |
| 159 | struct type *expect_type; |
| 160 | register struct expression *exp; |
| 161 | register int *pos; |
| 162 | enum noside noside; |
| 163 | { |
| 164 | enum exp_opcode op; |
| 165 | int tem, tem2, tem3; |
| 166 | register int pc, pc2, oldpos; |
| 167 | register value arg1, arg2, arg3; |
| 168 | struct type *type; |
| 169 | int nargs; |
| 170 | value *argvec; |
| 171 | |
| 172 | pc = (*pos)++; |
| 173 | op = exp->elts[pc].opcode; |
| 174 | |
| 175 | switch (op) |
| 176 | { |
| 177 | case OP_SCOPE: |
| 178 | tem = longest_to_int (exp->elts[pc + 2].longconst); |
| 179 | (*pos) += 4 + BYTES_TO_EXP_ELEM (tem + 1); |
| 180 | arg1 = value_struct_elt_for_reference (exp->elts[pc + 1].type, |
| 181 | 0, |
| 182 | exp->elts[pc + 1].type, |
| 183 | &exp->elts[pc + 3].string, |
| 184 | expect_type); |
| 185 | if (arg1 == NULL) |
| 186 | error ("There is no field named %s", &exp->elts[pc + 3].string); |
| 187 | return arg1; |
| 188 | |
| 189 | case OP_LONG: |
| 190 | (*pos) += 3; |
| 191 | return value_from_longest (exp->elts[pc + 1].type, |
| 192 | exp->elts[pc + 2].longconst); |
| 193 | |
| 194 | case OP_DOUBLE: |
| 195 | (*pos) += 3; |
| 196 | return value_from_double (exp->elts[pc + 1].type, |
| 197 | exp->elts[pc + 2].doubleconst); |
| 198 | |
| 199 | case OP_VAR_VALUE: |
| 200 | (*pos) += 3; |
| 201 | if (noside == EVAL_SKIP) |
| 202 | goto nosideret; |
| 203 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 204 | { |
| 205 | struct symbol * sym = exp->elts[pc + 1].symbol; |
| 206 | enum lval_type lv; |
| 207 | |
| 208 | switch (SYMBOL_CLASS (sym)) |
| 209 | { |
| 210 | case LOC_CONST: |
| 211 | case LOC_LABEL: |
| 212 | case LOC_CONST_BYTES: |
| 213 | lv = not_lval; |
| 214 | break; |
| 215 | |
| 216 | case LOC_REGISTER: |
| 217 | case LOC_REGPARM: |
| 218 | lv = lval_register; |
| 219 | break; |
| 220 | |
| 221 | default: |
| 222 | lv = lval_memory; |
| 223 | break; |
| 224 | } |
| 225 | |
| 226 | return value_zero (SYMBOL_TYPE (sym), lv); |
| 227 | } |
| 228 | else |
| 229 | return value_of_variable (exp->elts[pc + 2].symbol, |
| 230 | exp->elts[pc + 1].block); |
| 231 | |
| 232 | case OP_LAST: |
| 233 | (*pos) += 2; |
| 234 | return |
| 235 | access_value_history (longest_to_int (exp->elts[pc + 1].longconst)); |
| 236 | |
| 237 | case OP_REGISTER: |
| 238 | (*pos) += 2; |
| 239 | return value_of_register (longest_to_int (exp->elts[pc + 1].longconst)); |
| 240 | |
| 241 | case OP_BOOL: |
| 242 | (*pos) += 2; |
| 243 | return value_from_longest (builtin_type_chill_bool, |
| 244 | exp->elts[pc + 1].longconst); |
| 245 | |
| 246 | case OP_INTERNALVAR: |
| 247 | (*pos) += 2; |
| 248 | return value_of_internalvar (exp->elts[pc + 1].internalvar); |
| 249 | |
| 250 | case OP_STRING: |
| 251 | tem = longest_to_int (exp->elts[pc + 1].longconst); |
| 252 | (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1); |
| 253 | if (noside == EVAL_SKIP) |
| 254 | goto nosideret; |
| 255 | return value_string (&exp->elts[pc + 2].string, tem); |
| 256 | |
| 257 | case OP_BITSTRING: |
| 258 | error ("support for OP_BITSTRING unimplemented"); |
| 259 | break; |
| 260 | |
| 261 | case OP_ARRAY: |
| 262 | (*pos) += 3; |
| 263 | tem2 = longest_to_int (exp->elts[pc + 1].longconst); |
| 264 | tem3 = longest_to_int (exp->elts[pc + 2].longconst); |
| 265 | nargs = tem3 - tem2 + 1; |
| 266 | argvec = (value *) alloca (sizeof (value) * nargs); |
| 267 | for (tem = 0; tem < nargs; tem++) |
| 268 | { |
| 269 | /* Ensure that array expressions are coerced into pointer objects. */ |
| 270 | argvec[tem] = evaluate_subexp_with_coercion (exp, pos, noside); |
| 271 | } |
| 272 | if (noside == EVAL_SKIP) |
| 273 | goto nosideret; |
| 274 | return (value_array (tem2, tem3, argvec)); |
| 275 | break; |
| 276 | |
| 277 | case TERNOP_COND: |
| 278 | /* Skip third and second args to evaluate the first one. */ |
| 279 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 280 | if (value_logical_not (arg1)) |
| 281 | { |
| 282 | evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP); |
| 283 | return evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 284 | } |
| 285 | else |
| 286 | { |
| 287 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 288 | evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP); |
| 289 | return arg2; |
| 290 | } |
| 291 | |
| 292 | case OP_FUNCALL: |
| 293 | (*pos) += 2; |
| 294 | op = exp->elts[*pos].opcode; |
| 295 | if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR) |
| 296 | { |
| 297 | int fnptr; |
| 298 | |
| 299 | nargs = longest_to_int (exp->elts[pc + 1].longconst) + 1; |
| 300 | /* First, evaluate the structure into arg2 */ |
| 301 | pc2 = (*pos)++; |
| 302 | |
| 303 | if (noside == EVAL_SKIP) |
| 304 | goto nosideret; |
| 305 | |
| 306 | if (op == STRUCTOP_MEMBER) |
| 307 | { |
| 308 | arg2 = evaluate_subexp_for_address (exp, pos, noside); |
| 309 | } |
| 310 | else |
| 311 | { |
| 312 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 313 | } |
| 314 | |
| 315 | /* If the function is a virtual function, then the |
| 316 | aggregate value (providing the structure) plays |
| 317 | its part by providing the vtable. Otherwise, |
| 318 | it is just along for the ride: call the function |
| 319 | directly. */ |
| 320 | |
| 321 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 322 | |
| 323 | fnptr = longest_to_int (value_as_long (arg1)); |
| 324 | |
| 325 | if (METHOD_PTR_IS_VIRTUAL(fnptr)) |
| 326 | { |
| 327 | int fnoffset = METHOD_PTR_TO_VOFFSET(fnptr); |
| 328 | struct type *basetype; |
| 329 | struct type *domain_type = |
| 330 | TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (VALUE_TYPE (arg1))); |
| 331 | int i, j; |
| 332 | basetype = TYPE_TARGET_TYPE (VALUE_TYPE (arg2)); |
| 333 | if (domain_type != basetype) |
| 334 | arg2 = value_cast(lookup_pointer_type (domain_type), arg2); |
| 335 | basetype = TYPE_VPTR_BASETYPE (domain_type); |
| 336 | for (i = TYPE_NFN_FIELDS (basetype) - 1; i >= 0; i--) |
| 337 | { |
| 338 | struct fn_field *f = TYPE_FN_FIELDLIST1 (basetype, i); |
| 339 | /* If one is virtual, then all are virtual. */ |
| 340 | if (TYPE_FN_FIELD_VIRTUAL_P (f, 0)) |
| 341 | for (j = TYPE_FN_FIELDLIST_LENGTH (basetype, i) - 1; j >= 0; --j) |
| 342 | if (TYPE_FN_FIELD_VOFFSET (f, j) == fnoffset) |
| 343 | { |
| 344 | value temp = value_ind (arg2); |
| 345 | arg1 = value_virtual_fn_field (&temp, f, j, domain_type, 0); |
| 346 | arg2 = value_addr (temp); |
| 347 | goto got_it; |
| 348 | } |
| 349 | } |
| 350 | if (i < 0) |
| 351 | error ("virtual function at index %d not found", fnoffset); |
| 352 | } |
| 353 | else |
| 354 | { |
| 355 | VALUE_TYPE (arg1) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg1))); |
| 356 | } |
| 357 | got_it: |
| 358 | |
| 359 | /* Now, say which argument to start evaluating from */ |
| 360 | tem = 2; |
| 361 | } |
| 362 | else if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR) |
| 363 | { |
| 364 | /* Hair for method invocations */ |
| 365 | int tem2; |
| 366 | |
| 367 | nargs = longest_to_int (exp->elts[pc + 1].longconst) + 1; |
| 368 | /* First, evaluate the structure into arg2 */ |
| 369 | pc2 = (*pos)++; |
| 370 | tem2 = longest_to_int (exp->elts[pc2 + 1].longconst); |
| 371 | *pos += 3 + BYTES_TO_EXP_ELEM (tem2 + 1); |
| 372 | if (noside == EVAL_SKIP) |
| 373 | goto nosideret; |
| 374 | |
| 375 | if (op == STRUCTOP_STRUCT) |
| 376 | { |
| 377 | /* If v is a variable in a register, and the user types |
| 378 | v.method (), this will produce an error, because v has |
| 379 | no address. |
| 380 | |
| 381 | A possible way around this would be to allocate a |
| 382 | copy of the variable on the stack, copy in the |
| 383 | contents, call the function, and copy out the |
| 384 | contents. I.e. convert this from call by reference |
| 385 | to call by copy-return (or whatever it's called). |
| 386 | However, this does not work because it is not the |
| 387 | same: the method being called could stash a copy of |
| 388 | the address, and then future uses through that address |
| 389 | (after the method returns) would be expected to |
| 390 | use the variable itself, not some copy of it. */ |
| 391 | arg2 = evaluate_subexp_for_address (exp, pos, noside); |
| 392 | } |
| 393 | else |
| 394 | { |
| 395 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 396 | } |
| 397 | /* Now, say which argument to start evaluating from */ |
| 398 | tem = 2; |
| 399 | } |
| 400 | else |
| 401 | { |
| 402 | nargs = longest_to_int (exp->elts[pc + 1].longconst); |
| 403 | tem = 0; |
| 404 | } |
| 405 | /* Allocate arg vector, including space for the function to be |
| 406 | called in argvec[0] and a terminating NULL */ |
| 407 | argvec = (value *) alloca (sizeof (value) * (nargs + 2)); |
| 408 | for (; tem <= nargs; tem++) |
| 409 | /* Ensure that array expressions are coerced into pointer objects. */ |
| 410 | argvec[tem] = evaluate_subexp_with_coercion (exp, pos, noside); |
| 411 | |
| 412 | /* signal end of arglist */ |
| 413 | argvec[tem] = 0; |
| 414 | |
| 415 | if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR) |
| 416 | { |
| 417 | int static_memfuncp; |
| 418 | value temp = arg2; |
| 419 | |
| 420 | argvec[1] = arg2; |
| 421 | argvec[0] = |
| 422 | value_struct_elt (&temp, argvec+1, &exp->elts[pc2 + 2].string, |
| 423 | &static_memfuncp, |
| 424 | op == STRUCTOP_STRUCT |
| 425 | ? "structure" : "structure pointer"); |
| 426 | if (VALUE_OFFSET (temp)) |
| 427 | { |
| 428 | arg2 = value_from_longest (lookup_pointer_type (VALUE_TYPE (temp)), |
| 429 | VALUE_ADDRESS (temp)+VALUE_OFFSET (temp)); |
| 430 | argvec[1] = arg2; |
| 431 | } |
| 432 | if (static_memfuncp) |
| 433 | { |
| 434 | argvec[1] = argvec[0]; |
| 435 | nargs--; |
| 436 | argvec++; |
| 437 | } |
| 438 | } |
| 439 | else if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR) |
| 440 | { |
| 441 | argvec[1] = arg2; |
| 442 | argvec[0] = arg1; |
| 443 | } |
| 444 | |
| 445 | if (noside == EVAL_SKIP) |
| 446 | goto nosideret; |
| 447 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 448 | { |
| 449 | /* If the return type doesn't look like a function type, call an |
| 450 | error. This can happen if somebody tries to turn a variable into |
| 451 | a function call. This is here because people often want to |
| 452 | call, eg, strcmp, which gdb doesn't know is a function. If |
| 453 | gdb isn't asked for it's opinion (ie. through "whatis"), |
| 454 | it won't offer it. */ |
| 455 | |
| 456 | struct type *ftype = |
| 457 | TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0])); |
| 458 | |
| 459 | if (ftype) |
| 460 | return allocate_value (TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0]))); |
| 461 | else |
| 462 | error ("Expression of type other than \"Function returning ...\" used as function"); |
| 463 | } |
| 464 | return call_function_by_hand (argvec[0], nargs, argvec + 1); |
| 465 | |
| 466 | case STRUCTOP_STRUCT: |
| 467 | tem = longest_to_int (exp->elts[pc + 1].longconst); |
| 468 | (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1); |
| 469 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 470 | if (noside == EVAL_SKIP) |
| 471 | goto nosideret; |
| 472 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 473 | return value_zero (lookup_struct_elt_type (VALUE_TYPE (arg1), |
| 474 | &exp->elts[pc + 2].string, |
| 475 | 0), |
| 476 | lval_memory); |
| 477 | else |
| 478 | { |
| 479 | value temp = arg1; |
| 480 | return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 2].string, |
| 481 | (int *) 0, "structure"); |
| 482 | } |
| 483 | |
| 484 | case STRUCTOP_PTR: |
| 485 | tem = longest_to_int (exp->elts[pc + 1].longconst); |
| 486 | (*pos) += 3 + BYTES_TO_EXP_ELEM (tem + 1); |
| 487 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 488 | if (noside == EVAL_SKIP) |
| 489 | goto nosideret; |
| 490 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 491 | return value_zero (lookup_struct_elt_type (VALUE_TYPE (arg1), |
| 492 | &exp->elts[pc + 2].string, |
| 493 | 0), |
| 494 | lval_memory); |
| 495 | else |
| 496 | { |
| 497 | value temp = arg1; |
| 498 | return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 2].string, |
| 499 | (int *) 0, "structure pointer"); |
| 500 | } |
| 501 | |
| 502 | case STRUCTOP_MEMBER: |
| 503 | arg1 = evaluate_subexp_for_address (exp, pos, noside); |
| 504 | goto handle_pointer_to_member; |
| 505 | case STRUCTOP_MPTR: |
| 506 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 507 | handle_pointer_to_member: |
| 508 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 509 | if (noside == EVAL_SKIP) |
| 510 | goto nosideret; |
| 511 | if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_PTR) |
| 512 | goto bad_pointer_to_member; |
| 513 | type = TYPE_TARGET_TYPE (VALUE_TYPE (arg2)); |
| 514 | if (TYPE_CODE (type) == TYPE_CODE_METHOD) |
| 515 | error ("not implemented: pointer-to-method in pointer-to-member construct"); |
| 516 | if (TYPE_CODE (type) != TYPE_CODE_MEMBER) |
| 517 | goto bad_pointer_to_member; |
| 518 | /* Now, convert these values to an address. */ |
| 519 | arg1 = value_cast (lookup_pointer_type (TYPE_DOMAIN_TYPE (type)), |
| 520 | arg1); |
| 521 | arg3 = value_from_longest (lookup_pointer_type (TYPE_TARGET_TYPE (type)), |
| 522 | value_as_long (arg1) + value_as_long (arg2)); |
| 523 | return value_ind (arg3); |
| 524 | bad_pointer_to_member: |
| 525 | error("non-pointer-to-member value used in pointer-to-member construct"); |
| 526 | |
| 527 | case BINOP_CONCAT: |
| 528 | arg1 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 529 | arg2 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 530 | if (noside == EVAL_SKIP) |
| 531 | goto nosideret; |
| 532 | if (binop_user_defined_p (op, arg1, arg2)) |
| 533 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 534 | else |
| 535 | return value_concat (arg1, arg2); |
| 536 | |
| 537 | case BINOP_ASSIGN: |
| 538 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 539 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 540 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) |
| 541 | return arg1; |
| 542 | if (binop_user_defined_p (op, arg1, arg2)) |
| 543 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 544 | else |
| 545 | return value_assign (arg1, arg2); |
| 546 | |
| 547 | case BINOP_ASSIGN_MODIFY: |
| 548 | (*pos) += 2; |
| 549 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 550 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 551 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) |
| 552 | return arg1; |
| 553 | op = exp->elts[pc + 1].opcode; |
| 554 | if (binop_user_defined_p (op, arg1, arg2)) |
| 555 | return value_x_binop (arg1, arg2, BINOP_ASSIGN_MODIFY, op); |
| 556 | else if (op == BINOP_ADD) |
| 557 | arg2 = value_add (arg1, arg2); |
| 558 | else if (op == BINOP_SUB) |
| 559 | arg2 = value_sub (arg1, arg2); |
| 560 | else |
| 561 | arg2 = value_binop (arg1, arg2, op); |
| 562 | return value_assign (arg1, arg2); |
| 563 | |
| 564 | case BINOP_ADD: |
| 565 | arg1 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 566 | arg2 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 567 | if (noside == EVAL_SKIP) |
| 568 | goto nosideret; |
| 569 | if (binop_user_defined_p (op, arg1, arg2)) |
| 570 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 571 | else |
| 572 | return value_add (arg1, arg2); |
| 573 | |
| 574 | case BINOP_SUB: |
| 575 | arg1 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 576 | arg2 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 577 | if (noside == EVAL_SKIP) |
| 578 | goto nosideret; |
| 579 | if (binop_user_defined_p (op, arg1, arg2)) |
| 580 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 581 | else |
| 582 | return value_sub (arg1, arg2); |
| 583 | |
| 584 | case BINOP_MUL: |
| 585 | case BINOP_DIV: |
| 586 | case BINOP_REM: |
| 587 | case BINOP_MOD: |
| 588 | case BINOP_LSH: |
| 589 | case BINOP_RSH: |
| 590 | case BINOP_BITWISE_AND: |
| 591 | case BINOP_BITWISE_IOR: |
| 592 | case BINOP_BITWISE_XOR: |
| 593 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 594 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 595 | if (noside == EVAL_SKIP) |
| 596 | goto nosideret; |
| 597 | if (binop_user_defined_p (op, arg1, arg2)) |
| 598 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 599 | else |
| 600 | if (noside == EVAL_AVOID_SIDE_EFFECTS |
| 601 | && (op == BINOP_DIV || op == BINOP_REM || op == BINOP_MOD)) |
| 602 | return value_zero (VALUE_TYPE (arg1), not_lval); |
| 603 | else |
| 604 | return value_binop (arg1, arg2, op); |
| 605 | |
| 606 | case BINOP_SUBSCRIPT: |
| 607 | arg1 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 608 | arg2 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 609 | if (noside == EVAL_SKIP) |
| 610 | goto nosideret; |
| 611 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 612 | { |
| 613 | /* If the user attempts to subscript something that has no target |
| 614 | type (like a plain int variable for example), then report this |
| 615 | as an error. */ |
| 616 | |
| 617 | type = TYPE_TARGET_TYPE (VALUE_TYPE (arg1)); |
| 618 | if (type) |
| 619 | return value_zero (type, VALUE_LVAL (arg1)); |
| 620 | else |
| 621 | error ("cannot subscript something of type `%s'", |
| 622 | TYPE_NAME (VALUE_TYPE (arg1))); |
| 623 | } |
| 624 | |
| 625 | if (binop_user_defined_p (op, arg1, arg2)) |
| 626 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 627 | else |
| 628 | return value_subscript (arg1, arg2); |
| 629 | |
| 630 | case MULTI_SUBSCRIPT: |
| 631 | (*pos) += 2; |
| 632 | nargs = longest_to_int (exp->elts[pc + 1].longconst); |
| 633 | arg1 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 634 | while (nargs-- > 0) |
| 635 | { |
| 636 | arg2 = evaluate_subexp_with_coercion (exp, pos, noside); |
| 637 | /* FIXME: EVAL_SKIP handling may not be correct. */ |
| 638 | if (noside == EVAL_SKIP) |
| 639 | { |
| 640 | if (nargs > 0) |
| 641 | { |
| 642 | continue; |
| 643 | } |
| 644 | else |
| 645 | { |
| 646 | goto nosideret; |
| 647 | } |
| 648 | } |
| 649 | /* FIXME: EVAL_AVOID_SIDE_EFFECTS handling may not be correct. */ |
| 650 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 651 | { |
| 652 | /* If the user attempts to subscript something that has no target |
| 653 | type (like a plain int variable for example), then report this |
| 654 | as an error. */ |
| 655 | |
| 656 | type = TYPE_TARGET_TYPE (VALUE_TYPE (arg1)); |
| 657 | if (type != NULL) |
| 658 | { |
| 659 | arg1 = value_zero (type, VALUE_LVAL (arg1)); |
| 660 | noside = EVAL_SKIP; |
| 661 | continue; |
| 662 | } |
| 663 | else |
| 664 | { |
| 665 | error ("cannot subscript something of type `%s'", |
| 666 | TYPE_NAME (VALUE_TYPE (arg1))); |
| 667 | } |
| 668 | } |
| 669 | |
| 670 | if (binop_user_defined_p (op, arg1, arg2)) |
| 671 | { |
| 672 | arg1 = value_x_binop (arg1, arg2, op, OP_NULL); |
| 673 | } |
| 674 | else |
| 675 | { |
| 676 | arg1 = value_subscript (arg1, arg2); |
| 677 | } |
| 678 | } |
| 679 | return (arg1); |
| 680 | |
| 681 | case BINOP_LOGICAL_AND: |
| 682 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 683 | if (noside == EVAL_SKIP) |
| 684 | { |
| 685 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 686 | goto nosideret; |
| 687 | } |
| 688 | |
| 689 | oldpos = *pos; |
| 690 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS); |
| 691 | *pos = oldpos; |
| 692 | |
| 693 | if (binop_user_defined_p (op, arg1, arg2)) |
| 694 | { |
| 695 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 696 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 697 | } |
| 698 | else |
| 699 | { |
| 700 | tem = value_logical_not (arg1); |
| 701 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, |
| 702 | (tem ? EVAL_SKIP : noside)); |
| 703 | return value_from_longest (builtin_type_int, |
| 704 | (LONGEST) (!tem && !value_logical_not (arg2))); |
| 705 | } |
| 706 | |
| 707 | case BINOP_LOGICAL_OR: |
| 708 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 709 | if (noside == EVAL_SKIP) |
| 710 | { |
| 711 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 712 | goto nosideret; |
| 713 | } |
| 714 | |
| 715 | oldpos = *pos; |
| 716 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS); |
| 717 | *pos = oldpos; |
| 718 | |
| 719 | if (binop_user_defined_p (op, arg1, arg2)) |
| 720 | { |
| 721 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 722 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 723 | } |
| 724 | else |
| 725 | { |
| 726 | tem = value_logical_not (arg1); |
| 727 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, |
| 728 | (!tem ? EVAL_SKIP : noside)); |
| 729 | return value_from_longest (builtin_type_int, |
| 730 | (LONGEST) (!tem || !value_logical_not (arg2))); |
| 731 | } |
| 732 | |
| 733 | case BINOP_EQUAL: |
| 734 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 735 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 736 | if (noside == EVAL_SKIP) |
| 737 | goto nosideret; |
| 738 | if (binop_user_defined_p (op, arg1, arg2)) |
| 739 | { |
| 740 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 741 | } |
| 742 | else |
| 743 | { |
| 744 | tem = value_equal (arg1, arg2); |
| 745 | return value_from_longest (builtin_type_int, (LONGEST) tem); |
| 746 | } |
| 747 | |
| 748 | case BINOP_NOTEQUAL: |
| 749 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 750 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 751 | if (noside == EVAL_SKIP) |
| 752 | goto nosideret; |
| 753 | if (binop_user_defined_p (op, arg1, arg2)) |
| 754 | { |
| 755 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 756 | } |
| 757 | else |
| 758 | { |
| 759 | tem = value_equal (arg1, arg2); |
| 760 | return value_from_longest (builtin_type_int, (LONGEST) ! tem); |
| 761 | } |
| 762 | |
| 763 | case BINOP_LESS: |
| 764 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 765 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 766 | if (noside == EVAL_SKIP) |
| 767 | goto nosideret; |
| 768 | if (binop_user_defined_p (op, arg1, arg2)) |
| 769 | { |
| 770 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 771 | } |
| 772 | else |
| 773 | { |
| 774 | tem = value_less (arg1, arg2); |
| 775 | return value_from_longest (builtin_type_int, (LONGEST) tem); |
| 776 | } |
| 777 | |
| 778 | case BINOP_GTR: |
| 779 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 780 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 781 | if (noside == EVAL_SKIP) |
| 782 | goto nosideret; |
| 783 | if (binop_user_defined_p (op, arg1, arg2)) |
| 784 | { |
| 785 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 786 | } |
| 787 | else |
| 788 | { |
| 789 | tem = value_less (arg2, arg1); |
| 790 | return value_from_longest (builtin_type_int, (LONGEST) tem); |
| 791 | } |
| 792 | |
| 793 | case BINOP_GEQ: |
| 794 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 795 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 796 | if (noside == EVAL_SKIP) |
| 797 | goto nosideret; |
| 798 | if (binop_user_defined_p (op, arg1, arg2)) |
| 799 | { |
| 800 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 801 | } |
| 802 | else |
| 803 | { |
| 804 | tem = value_less (arg2, arg1) || value_equal (arg1, arg2); |
| 805 | return value_from_longest (builtin_type_int, (LONGEST) tem); |
| 806 | } |
| 807 | |
| 808 | case BINOP_LEQ: |
| 809 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 810 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); |
| 811 | if (noside == EVAL_SKIP) |
| 812 | goto nosideret; |
| 813 | if (binop_user_defined_p (op, arg1, arg2)) |
| 814 | { |
| 815 | return value_x_binop (arg1, arg2, op, OP_NULL); |
| 816 | } |
| 817 | else |
| 818 | { |
| 819 | tem = value_less (arg1, arg2) || value_equal (arg1, arg2); |
| 820 | return value_from_longest (builtin_type_int, (LONGEST) tem); |
| 821 | } |
| 822 | |
| 823 | case BINOP_REPEAT: |
| 824 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 825 | arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 826 | if (noside == EVAL_SKIP) |
| 827 | goto nosideret; |
| 828 | if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_INT) |
| 829 | error ("Non-integral right operand for \"@\" operator."); |
| 830 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 831 | return allocate_repeat_value (VALUE_TYPE (arg1), |
| 832 | longest_to_int (value_as_long (arg2))); |
| 833 | else |
| 834 | return value_repeat (arg1, longest_to_int (value_as_long (arg2))); |
| 835 | |
| 836 | case BINOP_COMMA: |
| 837 | evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 838 | return evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 839 | |
| 840 | case UNOP_NEG: |
| 841 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 842 | if (noside == EVAL_SKIP) |
| 843 | goto nosideret; |
| 844 | if (unop_user_defined_p (op, arg1)) |
| 845 | return value_x_unop (arg1, op); |
| 846 | else |
| 847 | return value_neg (arg1); |
| 848 | |
| 849 | case UNOP_COMPLEMENT: |
| 850 | /* C++: check for and handle destructor names. */ |
| 851 | op = exp->elts[*pos].opcode; |
| 852 | |
| 853 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 854 | if (noside == EVAL_SKIP) |
| 855 | goto nosideret; |
| 856 | if (unop_user_defined_p (UNOP_COMPLEMENT, arg1)) |
| 857 | return value_x_unop (arg1, UNOP_COMPLEMENT); |
| 858 | else |
| 859 | return value_complement (arg1); |
| 860 | |
| 861 | case UNOP_LOGICAL_NOT: |
| 862 | arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 863 | if (noside == EVAL_SKIP) |
| 864 | goto nosideret; |
| 865 | if (unop_user_defined_p (op, arg1)) |
| 866 | return value_x_unop (arg1, op); |
| 867 | else |
| 868 | return value_from_longest (builtin_type_int, |
| 869 | (LONGEST) value_logical_not (arg1)); |
| 870 | |
| 871 | case UNOP_IND: |
| 872 | if (expect_type && TYPE_CODE (expect_type) == TYPE_CODE_PTR) |
| 873 | expect_type = TYPE_TARGET_TYPE (expect_type); |
| 874 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); |
| 875 | if (noside == EVAL_SKIP) |
| 876 | goto nosideret; |
| 877 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 878 | { |
| 879 | if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR |
| 880 | || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_REF |
| 881 | /* In C you can dereference an array to get the 1st elt. */ |
| 882 | || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_ARRAY |
| 883 | ) |
| 884 | return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)), |
| 885 | lval_memory); |
| 886 | else if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_INT) |
| 887 | /* GDB allows dereferencing an int. */ |
| 888 | return value_zero (builtin_type_int, lval_memory); |
| 889 | else |
| 890 | error ("Attempt to take contents of a non-pointer value."); |
| 891 | } |
| 892 | return value_ind (arg1); |
| 893 | |
| 894 | case UNOP_ADDR: |
| 895 | /* C++: check for and handle pointer to members. */ |
| 896 | |
| 897 | op = exp->elts[*pos].opcode; |
| 898 | |
| 899 | if (noside == EVAL_SKIP) |
| 900 | { |
| 901 | if (op == OP_SCOPE) |
| 902 | { |
| 903 | int temm = longest_to_int (exp->elts[pc+3].longconst); |
| 904 | (*pos) += 3 + BYTES_TO_EXP_ELEM (temm + 1); |
| 905 | } |
| 906 | else |
| 907 | evaluate_subexp (expect_type, exp, pos, EVAL_SKIP); |
| 908 | goto nosideret; |
| 909 | } |
| 910 | |
| 911 | return evaluate_subexp_for_address (exp, pos, noside); |
| 912 | |
| 913 | case UNOP_SIZEOF: |
| 914 | if (noside == EVAL_SKIP) |
| 915 | { |
| 916 | evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP); |
| 917 | goto nosideret; |
| 918 | } |
| 919 | return evaluate_subexp_for_sizeof (exp, pos); |
| 920 | |
| 921 | case UNOP_CAST: |
| 922 | (*pos) += 2; |
| 923 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); |
| 924 | if (noside == EVAL_SKIP) |
| 925 | goto nosideret; |
| 926 | return value_cast (exp->elts[pc + 1].type, arg1); |
| 927 | |
| 928 | case UNOP_MEMVAL: |
| 929 | (*pos) += 2; |
| 930 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); |
| 931 | if (noside == EVAL_SKIP) |
| 932 | goto nosideret; |
| 933 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 934 | return value_zero (exp->elts[pc + 1].type, lval_memory); |
| 935 | else |
| 936 | return value_at_lazy (exp->elts[pc + 1].type, |
| 937 | value_as_pointer (arg1)); |
| 938 | |
| 939 | case UNOP_PREINCREMENT: |
| 940 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); |
| 941 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) |
| 942 | return arg1; |
| 943 | else if (unop_user_defined_p (op, arg1)) |
| 944 | { |
| 945 | return value_x_unop (arg1, op); |
| 946 | } |
| 947 | else |
| 948 | { |
| 949 | arg2 = value_add (arg1, value_from_longest (builtin_type_char, |
| 950 | (LONGEST) 1)); |
| 951 | return value_assign (arg1, arg2); |
| 952 | } |
| 953 | |
| 954 | case UNOP_PREDECREMENT: |
| 955 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); |
| 956 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) |
| 957 | return arg1; |
| 958 | else if (unop_user_defined_p (op, arg1)) |
| 959 | { |
| 960 | return value_x_unop (arg1, op); |
| 961 | } |
| 962 | else |
| 963 | { |
| 964 | arg2 = value_sub (arg1, value_from_longest (builtin_type_char, |
| 965 | (LONGEST) 1)); |
| 966 | return value_assign (arg1, arg2); |
| 967 | } |
| 968 | |
| 969 | case UNOP_POSTINCREMENT: |
| 970 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); |
| 971 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) |
| 972 | return arg1; |
| 973 | else if (unop_user_defined_p (op, arg1)) |
| 974 | { |
| 975 | return value_x_unop (arg1, op); |
| 976 | } |
| 977 | else |
| 978 | { |
| 979 | arg2 = value_add (arg1, value_from_longest (builtin_type_char, |
| 980 | (LONGEST) 1)); |
| 981 | value_assign (arg1, arg2); |
| 982 | return arg1; |
| 983 | } |
| 984 | |
| 985 | case UNOP_POSTDECREMENT: |
| 986 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); |
| 987 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) |
| 988 | return arg1; |
| 989 | else if (unop_user_defined_p (op, arg1)) |
| 990 | { |
| 991 | return value_x_unop (arg1, op); |
| 992 | } |
| 993 | else |
| 994 | { |
| 995 | arg2 = value_sub (arg1, value_from_longest (builtin_type_char, |
| 996 | (LONGEST) 1)); |
| 997 | value_assign (arg1, arg2); |
| 998 | return arg1; |
| 999 | } |
| 1000 | |
| 1001 | case OP_THIS: |
| 1002 | (*pos) += 1; |
| 1003 | return value_of_this (1); |
| 1004 | |
| 1005 | case OP_TYPE: |
| 1006 | error ("Attempt to use a type name as an expression"); |
| 1007 | |
| 1008 | default: |
| 1009 | /* Removing this case and compiling with gcc -Wall reveals that |
| 1010 | a lot of cases are hitting this case. Some of these should |
| 1011 | probably be removed from expression.h (e.g. do we need a BINOP_SCOPE |
| 1012 | and an OP_SCOPE?); others are legitimate expressions which are |
| 1013 | (apparently) not fully implemented. |
| 1014 | |
| 1015 | If there are any cases landing here which mean a user error, |
| 1016 | then they should be separate cases, with more descriptive |
| 1017 | error messages. */ |
| 1018 | |
| 1019 | error ("\ |
| 1020 | GDB does not (yet) know how to evaluated that kind of expression"); |
| 1021 | } |
| 1022 | |
| 1023 | nosideret: |
| 1024 | return value_from_longest (builtin_type_long, (LONGEST) 1); |
| 1025 | } |
| 1026 | \f |
| 1027 | /* Evaluate a subexpression of EXP, at index *POS, |
| 1028 | and return the address of that subexpression. |
| 1029 | Advance *POS over the subexpression. |
| 1030 | If the subexpression isn't an lvalue, get an error. |
| 1031 | NOSIDE may be EVAL_AVOID_SIDE_EFFECTS; |
| 1032 | then only the type of the result need be correct. */ |
| 1033 | |
| 1034 | static value |
| 1035 | evaluate_subexp_for_address (exp, pos, noside) |
| 1036 | register struct expression *exp; |
| 1037 | register int *pos; |
| 1038 | enum noside noside; |
| 1039 | { |
| 1040 | enum exp_opcode op; |
| 1041 | register int pc; |
| 1042 | struct symbol *var; |
| 1043 | |
| 1044 | pc = (*pos); |
| 1045 | op = exp->elts[pc].opcode; |
| 1046 | |
| 1047 | switch (op) |
| 1048 | { |
| 1049 | case UNOP_IND: |
| 1050 | (*pos)++; |
| 1051 | return evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 1052 | |
| 1053 | case UNOP_MEMVAL: |
| 1054 | (*pos) += 3; |
| 1055 | return value_cast (lookup_pointer_type (exp->elts[pc + 1].type), |
| 1056 | evaluate_subexp (NULL_TYPE, exp, pos, noside)); |
| 1057 | |
| 1058 | case OP_VAR_VALUE: |
| 1059 | var = exp->elts[pc + 2].symbol; |
| 1060 | |
| 1061 | /* C++: The "address" of a reference should yield the address |
| 1062 | * of the object pointed to. Let value_addr() deal with it. */ |
| 1063 | if (TYPE_CODE (SYMBOL_TYPE (var)) == TYPE_CODE_REF) |
| 1064 | goto default_case; |
| 1065 | |
| 1066 | (*pos) += 4; |
| 1067 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 1068 | { |
| 1069 | struct type *type = |
| 1070 | lookup_pointer_type (SYMBOL_TYPE (var)); |
| 1071 | enum address_class sym_class = SYMBOL_CLASS (var); |
| 1072 | |
| 1073 | if (sym_class == LOC_CONST |
| 1074 | || sym_class == LOC_CONST_BYTES |
| 1075 | || sym_class == LOC_REGISTER |
| 1076 | || sym_class == LOC_REGPARM) |
| 1077 | error ("Attempt to take address of register or constant."); |
| 1078 | |
| 1079 | return |
| 1080 | value_zero (type, not_lval); |
| 1081 | } |
| 1082 | else |
| 1083 | return |
| 1084 | locate_var_value |
| 1085 | (var, |
| 1086 | block_innermost_frame (exp->elts[pc + 1].block)); |
| 1087 | |
| 1088 | default: |
| 1089 | default_case: |
| 1090 | if (noside == EVAL_AVOID_SIDE_EFFECTS) |
| 1091 | { |
| 1092 | value x = evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 1093 | if (VALUE_LVAL (x) == lval_memory) |
| 1094 | return value_zero (lookup_pointer_type (VALUE_TYPE (x)), |
| 1095 | not_lval); |
| 1096 | else |
| 1097 | error ("Attempt to take address of non-lval"); |
| 1098 | } |
| 1099 | return value_addr (evaluate_subexp (NULL_TYPE, exp, pos, noside)); |
| 1100 | } |
| 1101 | } |
| 1102 | |
| 1103 | /* Evaluate like `evaluate_subexp' except coercing arrays to pointers. |
| 1104 | When used in contexts where arrays will be coerced anyway, this is |
| 1105 | equivalent to `evaluate_subexp' but much faster because it avoids |
| 1106 | actually fetching array contents (perhaps obsolete now that we have |
| 1107 | VALUE_LAZY). |
| 1108 | |
| 1109 | Note that we currently only do the coercion for C expressions, where |
| 1110 | arrays are zero based and the coercion is correct. For other languages, |
| 1111 | with nonzero based arrays, coercion loses. Use CAST_IS_CONVERSION |
| 1112 | to decide if coercion is appropriate. |
| 1113 | |
| 1114 | */ |
| 1115 | |
| 1116 | static value |
| 1117 | evaluate_subexp_with_coercion (exp, pos, noside) |
| 1118 | register struct expression *exp; |
| 1119 | register int *pos; |
| 1120 | enum noside noside; |
| 1121 | { |
| 1122 | register enum exp_opcode op; |
| 1123 | register int pc; |
| 1124 | register value val; |
| 1125 | struct symbol *var; |
| 1126 | |
| 1127 | pc = (*pos); |
| 1128 | op = exp->elts[pc].opcode; |
| 1129 | |
| 1130 | switch (op) |
| 1131 | { |
| 1132 | case OP_VAR_VALUE: |
| 1133 | var = exp->elts[pc + 2].symbol; |
| 1134 | if (TYPE_CODE (SYMBOL_TYPE (var)) == TYPE_CODE_ARRAY |
| 1135 | && CAST_IS_CONVERSION) |
| 1136 | { |
| 1137 | (*pos) += 4; |
| 1138 | val = |
| 1139 | locate_var_value |
| 1140 | (var, block_innermost_frame (exp->elts[pc + 1].block)); |
| 1141 | return value_cast (lookup_pointer_type (TYPE_TARGET_TYPE (SYMBOL_TYPE (var))), |
| 1142 | val); |
| 1143 | } |
| 1144 | /* FALLTHROUGH */ |
| 1145 | |
| 1146 | default: |
| 1147 | return evaluate_subexp (NULL_TYPE, exp, pos, noside); |
| 1148 | } |
| 1149 | } |
| 1150 | |
| 1151 | /* Evaluate a subexpression of EXP, at index *POS, |
| 1152 | and return a value for the size of that subexpression. |
| 1153 | Advance *POS over the subexpression. */ |
| 1154 | |
| 1155 | static value |
| 1156 | evaluate_subexp_for_sizeof (exp, pos) |
| 1157 | register struct expression *exp; |
| 1158 | register int *pos; |
| 1159 | { |
| 1160 | enum exp_opcode op; |
| 1161 | register int pc; |
| 1162 | value val; |
| 1163 | |
| 1164 | pc = (*pos); |
| 1165 | op = exp->elts[pc].opcode; |
| 1166 | |
| 1167 | switch (op) |
| 1168 | { |
| 1169 | /* This case is handled specially |
| 1170 | so that we avoid creating a value for the result type. |
| 1171 | If the result type is very big, it's desirable not to |
| 1172 | create a value unnecessarily. */ |
| 1173 | case UNOP_IND: |
| 1174 | (*pos)++; |
| 1175 | val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS); |
| 1176 | return value_from_longest (builtin_type_int, (LONGEST) |
| 1177 | TYPE_LENGTH (TYPE_TARGET_TYPE (VALUE_TYPE (val)))); |
| 1178 | |
| 1179 | case UNOP_MEMVAL: |
| 1180 | (*pos) += 3; |
| 1181 | return value_from_longest (builtin_type_int, |
| 1182 | (LONGEST) TYPE_LENGTH (exp->elts[pc + 1].type)); |
| 1183 | |
| 1184 | case OP_VAR_VALUE: |
| 1185 | (*pos) += 4; |
| 1186 | return |
| 1187 | value_from_longest |
| 1188 | (builtin_type_int, |
| 1189 | (LONGEST) TYPE_LENGTH (SYMBOL_TYPE (exp->elts[pc + 2].symbol))); |
| 1190 | |
| 1191 | default: |
| 1192 | val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS); |
| 1193 | return value_from_longest (builtin_type_int, |
| 1194 | (LONGEST) TYPE_LENGTH (VALUE_TYPE (val))); |
| 1195 | } |
| 1196 | } |
| 1197 | |
| 1198 | /* Parse a type expression in the string [P..P+LENGTH). */ |
| 1199 | |
| 1200 | struct type * |
| 1201 | parse_and_eval_type (p, length) |
| 1202 | char *p; |
| 1203 | int length; |
| 1204 | { |
| 1205 | char *tmp = (char *)alloca (length + 4); |
| 1206 | struct expression *expr; |
| 1207 | tmp[0] = '('; |
| 1208 | memcpy (tmp+1, p, length); |
| 1209 | tmp[length+1] = ')'; |
| 1210 | tmp[length+2] = '0'; |
| 1211 | tmp[length+3] = '\0'; |
| 1212 | expr = parse_expression (tmp); |
| 1213 | if (expr->elts[0].opcode != UNOP_CAST) |
| 1214 | error ("Internal error in eval_type."); |
| 1215 | return expr->elts[1].type; |
| 1216 | } |