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04497f0b NW |
1 | /*- |
2 | * This code is derived from software copyrighted by the Free Software | |
3 | * Foundation. | |
4 | * | |
5 | * Modified 1991 by Donn Seeley at UUNET Technologies, Inc. | |
6 | * Modified 1990 by Van Jacobson at Lawrence Berkeley Laboratory. | |
7 | */ | |
8 | ||
9 | #ifndef lint | |
10 | static char sccsid[] = "@(#)eval.c 6.3 (Berkeley) 5/8/91"; | |
11 | #endif /* not lint */ | |
12 | ||
13 | /* Evaluate expressions for GDB. | |
14 | Copyright (C) 1986, 1987, 1989 Free Software Foundation, Inc. | |
15 | ||
16 | This file is part of GDB. | |
17 | ||
18 | GDB is free software; you can redistribute it and/or modify | |
19 | it under the terms of the GNU General Public License as published by | |
20 | the Free Software Foundation; either version 1, or (at your option) | |
21 | any later version. | |
22 | ||
23 | GDB is distributed in the hope that it will be useful, | |
24 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
25 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
26 | GNU General Public License for more details. | |
27 | ||
28 | You should have received a copy of the GNU General Public License | |
29 | along with GDB; see the file COPYING. If not, write to | |
30 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
31 | ||
32 | #include "defs.h" | |
33 | #include "param.h" | |
34 | #include "symtab.h" | |
35 | #include "value.h" | |
36 | #include "expression.h" | |
37 | ||
38 | \f | |
39 | /* Parse the string EXP as a C expression, evaluate it, | |
40 | and return the result as a number. */ | |
41 | ||
42 | CORE_ADDR | |
43 | parse_and_eval_address (exp) | |
44 | char *exp; | |
45 | { | |
46 | struct expression *expr = parse_c_expression (exp); | |
47 | register CORE_ADDR addr; | |
48 | register struct cleanup *old_chain | |
49 | = make_cleanup (free_current_contents, &expr); | |
50 | ||
51 | addr = (CORE_ADDR) value_as_long (evaluate_expression (expr)); | |
52 | do_cleanups (old_chain); | |
53 | return addr; | |
54 | } | |
55 | ||
56 | /* Like parse_and_eval_address but takes a pointer to a char * variable | |
57 | and advanced that variable across the characters parsed. */ | |
58 | ||
59 | CORE_ADDR | |
60 | parse_and_eval_address_1 (expptr) | |
61 | char **expptr; | |
62 | { | |
63 | struct expression *expr = parse_c_1 (expptr, 0, 0); | |
64 | register CORE_ADDR addr; | |
65 | register struct cleanup *old_chain | |
66 | = make_cleanup (free_current_contents, &expr); | |
67 | ||
68 | addr = value_as_long (evaluate_expression (expr)); | |
69 | do_cleanups (old_chain); | |
70 | return addr; | |
71 | } | |
72 | ||
73 | value | |
74 | parse_and_eval (exp) | |
75 | char *exp; | |
76 | { | |
77 | struct expression *expr = parse_c_expression (exp); | |
78 | register value val; | |
79 | register struct cleanup *old_chain | |
80 | = make_cleanup (free_current_contents, &expr); | |
81 | ||
82 | val = evaluate_expression (expr); | |
83 | do_cleanups (old_chain); | |
84 | return val; | |
85 | } | |
86 | ||
87 | /* Parse up to a comma (or to a closeparen) | |
88 | in the string EXPP as an expression, evaluate it, and return the value. | |
89 | EXPP is advanced to point to the comma. */ | |
90 | ||
91 | value | |
92 | parse_to_comma_and_eval (expp) | |
93 | char **expp; | |
94 | { | |
95 | struct expression *expr = parse_c_1 (expp, 0, 1); | |
96 | register value val; | |
97 | register struct cleanup *old_chain | |
98 | = make_cleanup (free_current_contents, &expr); | |
99 | ||
100 | val = evaluate_expression (expr); | |
101 | do_cleanups (old_chain); | |
102 | return val; | |
103 | } | |
104 | \f | |
105 | /* Evaluate an expression in internal prefix form | |
106 | such as is constructed by expread.y. | |
107 | ||
108 | See expression.h for info on the format of an expression. */ | |
109 | ||
110 | static value evaluate_subexp (); | |
111 | static value evaluate_subexp_for_address (); | |
112 | static value evaluate_subexp_for_sizeof (); | |
113 | static value evaluate_subexp_with_coercion (); | |
114 | ||
115 | /* return true if 'var' has an address in inferior's memory. */ | |
116 | static int | |
117 | value_has_lval(var) | |
118 | register struct symbol *var; | |
119 | { | |
120 | switch (SYMBOL_CLASS(var)) | |
121 | { | |
122 | case LOC_STATIC: | |
123 | case LOC_LABEL: | |
124 | case LOC_ARG: | |
125 | case LOC_REF_ARG: | |
126 | case LOC_LOCAL: | |
127 | case LOC_BLOCK: | |
128 | return (1); | |
129 | } | |
130 | return (0); | |
131 | } | |
132 | ||
133 | /* Values of NOSIDE argument to eval_subexp. */ | |
134 | enum noside | |
135 | { EVAL_NORMAL, | |
136 | EVAL_SKIP, /* Only effect is to increment pos. */ | |
137 | EVAL_AVOID_SIDE_EFFECTS, /* Don't modify any variables or | |
138 | call any functions. The value | |
139 | returned will have the correct | |
140 | type, and will have an | |
141 | approximately correct lvalue | |
142 | type (inaccuracy: anything that is | |
143 | listed as being in a register in | |
144 | the function in which it was | |
145 | declared will be lval_register). */ | |
146 | }; | |
147 | ||
148 | value | |
149 | evaluate_expression (exp) | |
150 | struct expression *exp; | |
151 | { | |
152 | int pc = 0; | |
153 | return evaluate_subexp (0, exp, &pc, EVAL_NORMAL); | |
154 | } | |
155 | ||
156 | /* Evaluate an expression, avoiding all memory references | |
157 | and getting a value whose type alone is correct. */ | |
158 | ||
159 | value | |
160 | evaluate_type (exp) | |
161 | struct expression *exp; | |
162 | { | |
163 | int pc = 0; | |
164 | return evaluate_subexp (0, exp, &pc, EVAL_AVOID_SIDE_EFFECTS); | |
165 | } | |
166 | ||
167 | static value | |
168 | evaluate_subexp (expect_type, exp, pos, noside) | |
169 | struct type *expect_type; | |
170 | register struct expression *exp; | |
171 | register int *pos; | |
172 | enum noside noside; | |
173 | { | |
174 | enum exp_opcode op; | |
175 | int tem; | |
176 | register int pc, pc2, oldpos; | |
177 | register value arg1, arg2, arg3; | |
178 | int nargs; | |
179 | value *argvec; | |
180 | ||
181 | pc = (*pos)++; | |
182 | op = exp->elts[pc].opcode; | |
183 | ||
184 | switch (op) | |
185 | { | |
186 | case OP_SCOPE: | |
187 | tem = strlen (&exp->elts[pc + 2].string); | |
188 | (*pos) += 3 + ((tem + sizeof (union exp_element)) | |
189 | / sizeof (union exp_element)); | |
190 | return value_static_field (exp->elts[pc + 1].type, | |
191 | &exp->elts[pc + 2].string, -1); | |
192 | ||
193 | case OP_LONG: | |
194 | (*pos) += 3; | |
195 | return value_from_long (exp->elts[pc + 1].type, | |
196 | exp->elts[pc + 2].longconst); | |
197 | ||
198 | case OP_DOUBLE: | |
199 | (*pos) += 3; | |
200 | return value_from_double (exp->elts[pc + 1].type, | |
201 | exp->elts[pc + 2].doubleconst); | |
202 | ||
203 | case OP_VAR_VALUE: | |
204 | (*pos) += 2; | |
205 | if (noside == EVAL_SKIP) | |
206 | goto nosideret; | |
207 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
208 | { | |
209 | struct symbol * sym = exp->elts[pc + 1].symbol; | |
210 | enum lval_type lv; | |
211 | ||
212 | switch (SYMBOL_CLASS (sym)) | |
213 | { | |
214 | case LOC_CONST: | |
215 | case LOC_LABEL: | |
216 | case LOC_CONST_BYTES: | |
217 | lv = not_lval; | |
218 | case LOC_REGISTER: | |
219 | case LOC_REGPARM: | |
220 | lv = lval_register; | |
221 | default: | |
222 | lv = lval_memory; | |
223 | } | |
224 | ||
225 | return value_zero (SYMBOL_TYPE (sym), lv); | |
226 | } | |
227 | else | |
228 | return value_of_variable (exp->elts[pc + 1].symbol); | |
229 | ||
230 | case OP_LAST: | |
231 | (*pos) += 2; | |
232 | return access_value_history ((int) exp->elts[pc + 1].longconst); | |
233 | ||
234 | case OP_REGISTER: | |
235 | (*pos) += 2; | |
236 | return value_of_register ((int) exp->elts[pc + 1].longconst); | |
237 | ||
238 | case OP_INTERNALVAR: | |
239 | (*pos) += 2; | |
240 | return value_of_internalvar (exp->elts[pc + 1].internalvar); | |
241 | ||
242 | case OP_STRING: | |
243 | tem = strlen (&exp->elts[pc + 1].string); | |
244 | (*pos) += 2 + ((tem + sizeof (union exp_element)) | |
245 | / sizeof (union exp_element)); | |
246 | if (noside == EVAL_SKIP) | |
247 | goto nosideret; | |
248 | return value_string (&exp->elts[pc + 1].string, tem); | |
249 | ||
250 | case TERNOP_COND: | |
251 | /* Skip third and second args to evaluate the first one. */ | |
252 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
253 | if (value_zerop (arg1)) | |
254 | { | |
255 | evaluate_subexp (0, exp, pos, EVAL_SKIP); | |
256 | return evaluate_subexp (0, exp, pos, noside); | |
257 | } | |
258 | else | |
259 | { | |
260 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
261 | evaluate_subexp (0, exp, pos, EVAL_SKIP); | |
262 | return arg2; | |
263 | } | |
264 | ||
265 | case OP_FUNCALL: | |
266 | (*pos) += 2; | |
267 | op = exp->elts[*pos].opcode; | |
268 | if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR) | |
269 | { | |
270 | int fnptr; | |
271 | int tem2; | |
272 | ||
273 | nargs = (int) exp->elts[pc + 1].longconst + 1; | |
274 | /* First, evaluate the structure into arg2 */ | |
275 | pc2 = (*pos)++; | |
276 | ||
277 | if (noside == EVAL_SKIP) | |
278 | goto nosideret; | |
279 | ||
280 | if (op == STRUCTOP_MEMBER) | |
281 | { | |
282 | arg2 = evaluate_subexp_for_address (exp, pos, noside); | |
283 | } | |
284 | else | |
285 | { | |
286 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
287 | } | |
288 | ||
289 | /* If the function is a virtual function, then the | |
290 | aggregate value (providing the structure) plays | |
291 | its part by providing the vtable. Otherwise, | |
292 | it is just along for the ride: call the function | |
293 | directly. */ | |
294 | ||
295 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
296 | ||
297 | fnptr = (int) value_as_long (arg1); | |
298 | if (fnptr < 128) | |
299 | { | |
300 | struct type *basetype; | |
301 | int i, j; | |
302 | basetype = TYPE_TARGET_TYPE (VALUE_TYPE (arg2)); | |
303 | basetype = TYPE_VPTR_BASETYPE (basetype); | |
304 | for (i = TYPE_NFN_FIELDS (basetype) - 1; i >= 0; i--) | |
305 | { | |
306 | struct fn_field *f = TYPE_FN_FIELDLIST1 (basetype, i); | |
307 | /* If one is virtual, then all are virtual. */ | |
308 | if (TYPE_FN_FIELD_VIRTUAL_P (f, 0)) | |
309 | for (j = TYPE_FN_FIELDLIST_LENGTH (basetype, i) - 1; j >= 0; --j) | |
310 | if (TYPE_FN_FIELD_VOFFSET (f, j) == fnptr) | |
311 | { | |
312 | value vtbl; | |
313 | value base = value_ind (arg2); | |
314 | struct type *fntype = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j)); | |
315 | ||
316 | if (TYPE_VPTR_FIELDNO (basetype) < 0) | |
317 | TYPE_VPTR_FIELDNO (basetype) | |
318 | = fill_in_vptr_fieldno (basetype); | |
319 | ||
320 | VALUE_TYPE (base) = basetype; | |
321 | vtbl = value_field (base, TYPE_VPTR_FIELDNO (basetype)); | |
322 | VALUE_TYPE (vtbl) = lookup_pointer_type (fntype); | |
323 | VALUE_TYPE (arg1) = builtin_type_int; | |
324 | arg1 = value_subscript (vtbl, arg1); | |
325 | VALUE_TYPE (arg1) = fntype; | |
326 | goto got_it; | |
327 | } | |
328 | } | |
329 | if (i < 0) | |
330 | error ("virtual function at index %d not found", fnptr); | |
331 | } | |
332 | else | |
333 | { | |
334 | VALUE_TYPE (arg1) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg1))); | |
335 | } | |
336 | got_it: | |
337 | ||
338 | /* Now, say which argument to start evaluating from */ | |
339 | tem = 2; | |
340 | } | |
341 | else if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR) | |
342 | { | |
343 | /* Hair for method invocations */ | |
344 | int tem2; | |
345 | ||
346 | nargs = (int) exp->elts[pc + 1].longconst + 1; | |
347 | /* First, evaluate the structure into arg2 */ | |
348 | pc2 = (*pos)++; | |
349 | tem2 = strlen (&exp->elts[pc2 + 1].string); | |
350 | *pos += 2 + (tem2 + sizeof (union exp_element)) / sizeof (union exp_element); | |
351 | if (noside == EVAL_SKIP) | |
352 | goto nosideret; | |
353 | ||
354 | if (op == STRUCTOP_STRUCT) | |
355 | { | |
356 | arg2 = evaluate_subexp_for_address (exp, pos, noside); | |
357 | } | |
358 | else | |
359 | { | |
360 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
361 | } | |
362 | /* Now, say which argument to start evaluating from */ | |
363 | tem = 2; | |
364 | } | |
365 | else | |
366 | { | |
367 | nargs = (int) exp->elts[pc + 1].longconst; | |
368 | tem = 0; | |
369 | } | |
370 | argvec = (value *) alloca (sizeof (value) * (nargs + 2)); | |
371 | for (; tem <= nargs; tem++) | |
372 | /* Ensure that array expressions are coerced into pointer objects. */ | |
373 | argvec[tem] = evaluate_subexp_with_coercion (exp, pos, noside); | |
374 | ||
375 | /* signal end of arglist */ | |
376 | argvec[tem] = 0; | |
377 | ||
378 | if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR) | |
379 | { | |
380 | int static_memfuncp; | |
381 | ||
382 | argvec[1] = arg2; | |
383 | argvec[0] = | |
384 | value_struct_elt (arg2, argvec+1, &exp->elts[pc2 + 1].string, | |
385 | &static_memfuncp, | |
386 | op == STRUCTOP_STRUCT | |
387 | ? "structure" : "structure pointer"); | |
388 | if (static_memfuncp) | |
389 | { | |
390 | argvec[1] = argvec[0]; | |
391 | nargs--; | |
392 | argvec++; | |
393 | } | |
394 | } | |
395 | else if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR) | |
396 | { | |
397 | argvec[1] = arg2; | |
398 | argvec[0] = arg1; | |
399 | } | |
400 | ||
401 | if (noside == EVAL_SKIP) | |
402 | goto nosideret; | |
403 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
404 | { | |
405 | /* If the return type doesn't look like a function type, call an | |
406 | error. This can happen if somebody tries to turn a variable into | |
407 | a function call. This is here because people often want to | |
408 | call, eg, strcmp, which gdb doesn't know is a function. If | |
409 | gdb isn't asked for it's opinion (ie. through "whatis"), | |
410 | it won't offer it. */ | |
411 | ||
412 | struct type *ftype = | |
413 | TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0])); | |
414 | ||
415 | if (ftype) | |
416 | return allocate_value (TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0]))); | |
417 | else | |
418 | error ("Expression of type other than \"Function returning ...\" used as function"); | |
419 | } | |
420 | return call_function (argvec[0], nargs, argvec + 1); | |
421 | ||
422 | case STRUCTOP_STRUCT: | |
423 | tem = strlen (&exp->elts[pc + 1].string); | |
424 | (*pos) += 2 + ((tem + sizeof (union exp_element)) | |
425 | / sizeof (union exp_element)); | |
426 | ||
427 | /* Try to convert "foo.bar" into "(&foo)->bar" so we won't copy | |
428 | * the entire contents of a large struct just to extract one | |
429 | * value from it. */ | |
430 | if (noside == EVAL_NORMAL && exp->elts[*pos].opcode == OP_VAR_VALUE | |
431 | && value_has_lval(exp->elts[*pos + 1].symbol)) | |
432 | arg1 = evaluate_subexp_for_address(exp, pos, noside); | |
433 | else | |
434 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
435 | ||
436 | if (noside == EVAL_SKIP) | |
437 | goto nosideret; | |
438 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
439 | { | |
440 | register struct type *type = VALUE_TYPE (arg1); | |
441 | if (TYPE_CODE (type) == TYPE_CODE_PTR) | |
442 | type = TYPE_TARGET_TYPE (type); | |
443 | return value_zero (lookup_struct_elt_type (type, | |
444 | &exp->elts[pc + 1].string), | |
445 | lval_memory); | |
446 | } | |
447 | else | |
448 | return value_struct_elt (arg1, 0, &exp->elts[pc + 1].string, 0, | |
449 | "structure"); | |
450 | ||
451 | case STRUCTOP_PTR: | |
452 | tem = strlen (&exp->elts[pc + 1].string); | |
453 | (*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element); | |
454 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
455 | if (noside == EVAL_SKIP) | |
456 | goto nosideret; | |
457 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
458 | return value_zero (lookup_struct_elt_type (TYPE_TARGET_TYPE | |
459 | (VALUE_TYPE (arg1)), | |
460 | &exp->elts[pc + 1].string), | |
461 | lval_memory); | |
462 | else | |
463 | return value_struct_elt (arg1, 0, &exp->elts[pc + 1].string, 0, | |
464 | "structure pointer"); | |
465 | ||
466 | case STRUCTOP_MEMBER: | |
467 | arg1 = evaluate_subexp_for_address (exp, pos, noside); | |
468 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
469 | if (noside == EVAL_SKIP) | |
470 | goto nosideret; | |
471 | /* Now, convert these values to an address. */ | |
472 | if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_PTR | |
473 | || ((TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))) | |
474 | != TYPE_CODE_MEMBER) | |
475 | && (TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))) | |
476 | != TYPE_CODE_METHOD))) | |
477 | error ("non-pointer-to-member value used in pointer-to-member construct"); | |
478 | arg3 = value_from_long (builtin_type_long, | |
479 | value_as_long (arg1) + value_as_long (arg2)); | |
480 | VALUE_TYPE (arg3) = | |
481 | lookup_pointer_type (TYPE_TARGET_TYPE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2)))); | |
482 | return value_ind (arg3); | |
483 | ||
484 | case STRUCTOP_MPTR: | |
485 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
486 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
487 | if (noside == EVAL_SKIP) | |
488 | goto nosideret; | |
489 | /* Now, convert these values to an address. */ | |
490 | if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_PTR | |
491 | || (TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))) != TYPE_CODE_MEMBER | |
492 | && TYPE_CODE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2))) != TYPE_CODE_METHOD)) | |
493 | error ("non-pointer-to-member value used in pointer-to-member construct"); | |
494 | arg3 = value_from_long (builtin_type_long, | |
495 | value_as_long (arg1) + value_as_long (arg2)); | |
496 | VALUE_TYPE (arg3) = | |
497 | lookup_pointer_type (TYPE_TARGET_TYPE (TYPE_TARGET_TYPE (VALUE_TYPE (arg2)))); | |
498 | return value_ind (arg3); | |
499 | ||
500 | case BINOP_ASSIGN: | |
501 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
502 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
503 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) | |
504 | return arg1; | |
505 | if (binop_user_defined_p (op, arg1, arg2)) | |
506 | return value_x_binop (arg1, arg2, op, 0); | |
507 | else | |
508 | return value_assign (arg1, arg2); | |
509 | ||
510 | case BINOP_ASSIGN_MODIFY: | |
511 | (*pos) += 2; | |
512 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
513 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
514 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) | |
515 | return arg1; | |
516 | op = exp->elts[pc + 1].opcode; | |
517 | if (binop_user_defined_p (op, arg1, arg2)) | |
518 | return value_x_binop (arg1, arg2, BINOP_ASSIGN_MODIFY, op); | |
519 | else if (op == BINOP_ADD) | |
520 | arg2 = value_add (arg1, arg2); | |
521 | else if (op == BINOP_SUB) | |
522 | arg2 = value_sub (arg1, arg2); | |
523 | else | |
524 | arg2 = value_binop (arg1, arg2, op); | |
525 | return value_assign (arg1, arg2); | |
526 | ||
527 | case BINOP_ADD: | |
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, 0); | |
534 | else | |
535 | return value_add (arg1, arg2); | |
536 | ||
537 | case BINOP_SUB: | |
538 | arg1 = evaluate_subexp_with_coercion (exp, pos, noside); | |
539 | arg2 = evaluate_subexp_with_coercion (exp, pos, noside); | |
540 | if (noside == EVAL_SKIP) | |
541 | goto nosideret; | |
542 | if (binop_user_defined_p (op, arg1, arg2)) | |
543 | return value_x_binop (arg1, arg2, op, 0); | |
544 | else | |
545 | return value_sub (arg1, arg2); | |
546 | ||
547 | case BINOP_MUL: | |
548 | case BINOP_DIV: | |
549 | case BINOP_REM: | |
550 | case BINOP_LSH: | |
551 | case BINOP_RSH: | |
552 | case BINOP_LOGAND: | |
553 | case BINOP_LOGIOR: | |
554 | case BINOP_LOGXOR: | |
555 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
556 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
557 | if (noside == EVAL_SKIP) | |
558 | goto nosideret; | |
559 | if (binop_user_defined_p (op, arg1, arg2)) | |
560 | return value_x_binop (arg1, arg2, op, 0); | |
561 | else | |
562 | if (noside == EVAL_AVOID_SIDE_EFFECTS | |
563 | && op == BINOP_DIV) | |
564 | return value_zero (VALUE_TYPE (arg1), not_lval); | |
565 | else | |
566 | return value_binop (arg1, arg2, op); | |
567 | ||
568 | case BINOP_SUBSCRIPT: | |
569 | arg1 = evaluate_subexp_with_coercion (exp, pos, noside); | |
570 | arg2 = evaluate_subexp_with_coercion (exp, pos, noside); | |
571 | if (noside == EVAL_SKIP) | |
572 | goto nosideret; | |
573 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
574 | return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)), | |
575 | VALUE_LVAL (arg1)); | |
576 | ||
577 | if (binop_user_defined_p (op, arg1, arg2)) | |
578 | return value_x_binop (arg1, arg2, op, 0); | |
579 | else | |
580 | return value_subscript (arg1, arg2); | |
581 | ||
582 | case BINOP_AND: | |
583 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
584 | if (noside == EVAL_SKIP) | |
585 | { | |
586 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
587 | goto nosideret; | |
588 | } | |
589 | ||
590 | oldpos = *pos; | |
591 | arg2 = evaluate_subexp (0, exp, pos, EVAL_AVOID_SIDE_EFFECTS); | |
592 | *pos = oldpos; | |
593 | ||
594 | if (binop_user_defined_p (op, arg1, arg2)) | |
595 | { | |
596 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
597 | return value_x_binop (arg1, arg2, op, 0); | |
598 | } | |
599 | else | |
600 | { | |
601 | tem = value_zerop (arg1); | |
602 | arg2 = evaluate_subexp (0, exp, pos, | |
603 | (tem ? EVAL_SKIP : noside)); | |
604 | return value_from_long (builtin_type_int, | |
605 | (LONGEST) (!tem && !value_zerop (arg2))); | |
606 | } | |
607 | ||
608 | case BINOP_OR: | |
609 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
610 | if (noside == EVAL_SKIP) | |
611 | { | |
612 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
613 | goto nosideret; | |
614 | } | |
615 | ||
616 | oldpos = *pos; | |
617 | arg2 = evaluate_subexp (0, exp, pos, EVAL_AVOID_SIDE_EFFECTS); | |
618 | *pos = oldpos; | |
619 | ||
620 | if (binop_user_defined_p (op, arg1, arg2)) | |
621 | { | |
622 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
623 | return value_x_binop (arg1, arg2, op, 0); | |
624 | } | |
625 | else | |
626 | { | |
627 | tem = value_zerop (arg1); | |
628 | arg2 = evaluate_subexp (0, exp, pos, | |
629 | (!tem ? EVAL_SKIP : noside)); | |
630 | return value_from_long (builtin_type_int, | |
631 | (LONGEST) (!tem || !value_zerop (arg2))); | |
632 | } | |
633 | ||
634 | case BINOP_EQUAL: | |
635 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
636 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
637 | if (noside == EVAL_SKIP) | |
638 | goto nosideret; | |
639 | if (binop_user_defined_p (op, arg1, arg2)) | |
640 | { | |
641 | return value_x_binop (arg1, arg2, op, 0); | |
642 | } | |
643 | else | |
644 | { | |
645 | tem = value_equal (arg1, arg2); | |
646 | return value_from_long (builtin_type_int, (LONGEST) tem); | |
647 | } | |
648 | ||
649 | case BINOP_NOTEQUAL: | |
650 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
651 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
652 | if (noside == EVAL_SKIP) | |
653 | goto nosideret; | |
654 | if (binop_user_defined_p (op, arg1, arg2)) | |
655 | { | |
656 | return value_x_binop (arg1, arg2, op, 0); | |
657 | } | |
658 | else | |
659 | { | |
660 | tem = value_equal (arg1, arg2); | |
661 | return value_from_long (builtin_type_int, (LONGEST) ! tem); | |
662 | } | |
663 | ||
664 | case BINOP_LESS: | |
665 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
666 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
667 | if (noside == EVAL_SKIP) | |
668 | goto nosideret; | |
669 | if (binop_user_defined_p (op, arg1, arg2)) | |
670 | { | |
671 | return value_x_binop (arg1, arg2, op, 0); | |
672 | } | |
673 | else | |
674 | { | |
675 | tem = value_less (arg1, arg2); | |
676 | return value_from_long (builtin_type_int, (LONGEST) tem); | |
677 | } | |
678 | ||
679 | case BINOP_GTR: | |
680 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
681 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
682 | if (noside == EVAL_SKIP) | |
683 | goto nosideret; | |
684 | if (binop_user_defined_p (op, arg1, arg2)) | |
685 | { | |
686 | return value_x_binop (arg1, arg2, op, 0); | |
687 | } | |
688 | else | |
689 | { | |
690 | tem = value_less (arg2, arg1); | |
691 | return value_from_long (builtin_type_int, (LONGEST) tem); | |
692 | } | |
693 | ||
694 | case BINOP_GEQ: | |
695 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
696 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
697 | if (noside == EVAL_SKIP) | |
698 | goto nosideret; | |
699 | if (binop_user_defined_p (op, arg1, arg2)) | |
700 | { | |
701 | return value_x_binop (arg1, arg2, op, 0); | |
702 | } | |
703 | else | |
704 | { | |
705 | tem = value_less (arg1, arg2); | |
706 | return value_from_long (builtin_type_int, (LONGEST) ! tem); | |
707 | } | |
708 | ||
709 | case BINOP_LEQ: | |
710 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
711 | arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside); | |
712 | if (noside == EVAL_SKIP) | |
713 | goto nosideret; | |
714 | if (binop_user_defined_p (op, arg1, arg2)) | |
715 | { | |
716 | return value_x_binop (arg1, arg2, op, 0); | |
717 | } | |
718 | else | |
719 | { | |
720 | tem = value_less (arg2, arg1); | |
721 | return value_from_long (builtin_type_int, (LONGEST) ! tem); | |
722 | } | |
723 | ||
724 | case BINOP_REPEAT: | |
725 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
726 | arg2 = evaluate_subexp (0, exp, pos, noside); | |
727 | if (noside == EVAL_SKIP) | |
728 | goto nosideret; | |
729 | if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_INT) | |
730 | error ("Non-integral right operand for \"@\" operator."); | |
731 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
732 | return allocate_repeat_value (VALUE_TYPE (arg1), | |
733 | (int) value_as_long (arg2)); | |
734 | else | |
735 | return value_repeat (arg1, (int) value_as_long (arg2)); | |
736 | ||
737 | case BINOP_COMMA: | |
738 | evaluate_subexp (0, exp, pos, noside); | |
739 | return evaluate_subexp (0, exp, pos, noside); | |
740 | ||
741 | case UNOP_NEG: | |
742 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
743 | if (noside == EVAL_SKIP) | |
744 | goto nosideret; | |
745 | if (unop_user_defined_p (op, arg1)) | |
746 | return value_x_unop (arg1, op); | |
747 | else | |
748 | return value_neg (arg1); | |
749 | ||
750 | case UNOP_LOGNOT: | |
751 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
752 | if (noside == EVAL_SKIP) | |
753 | goto nosideret; | |
754 | if (unop_user_defined_p (op, arg1)) | |
755 | return value_x_unop (arg1, op); | |
756 | else | |
757 | return value_lognot (arg1); | |
758 | ||
759 | case UNOP_ZEROP: | |
760 | arg1 = evaluate_subexp (0, exp, pos, noside); | |
761 | if (noside == EVAL_SKIP) | |
762 | goto nosideret; | |
763 | if (unop_user_defined_p (op, arg1)) | |
764 | return value_x_unop (arg1, op); | |
765 | else | |
766 | return value_from_long (builtin_type_int, | |
767 | (LONGEST) value_zerop (arg1)); | |
768 | ||
769 | case UNOP_IND: | |
770 | if (expect_type && TYPE_CODE (expect_type) == TYPE_CODE_PTR) | |
771 | expect_type = TYPE_TARGET_TYPE (expect_type); | |
772 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); | |
773 | if (noside == EVAL_SKIP) | |
774 | goto nosideret; | |
775 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
776 | { | |
777 | if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR | |
778 | || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_REF | |
779 | /* In C you can dereference an array to get the 1st elt. */ | |
780 | || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_ARRAY | |
781 | ) | |
782 | return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)), | |
783 | lval_memory); | |
784 | else if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_INT) | |
785 | /* GDB allows dereferencing an int. */ | |
786 | return value_zero (builtin_type_int, lval_memory); | |
787 | else | |
788 | error ("Attempt to take contents of a non-pointer value."); | |
789 | } | |
790 | return value_ind (arg1); | |
791 | ||
792 | case UNOP_ADDR: | |
793 | /* C++: check for and handle pointer to members. */ | |
794 | ||
795 | op = exp->elts[*pos].opcode; | |
796 | ||
797 | if (noside == EVAL_SKIP) | |
798 | { | |
799 | if (op == OP_SCOPE) | |
800 | { | |
801 | char *name = &exp->elts[pc+3].string; | |
802 | int tem = strlen (name); | |
803 | (*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element); | |
804 | } | |
805 | else | |
806 | evaluate_subexp (expect_type, exp, pos, EVAL_SKIP); | |
807 | goto nosideret; | |
808 | } | |
809 | ||
810 | if (op == OP_SCOPE) | |
811 | { | |
812 | char *name = &exp->elts[pc+3].string; | |
813 | int tem = strlen (name); | |
814 | struct type *domain = exp->elts[pc+2].type; | |
815 | (*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element); | |
816 | arg1 = value_struct_elt_for_address (domain, expect_type, name); | |
817 | if (arg1) | |
818 | return arg1; | |
819 | error ("no field `%s' in structure", name); | |
820 | } | |
821 | else | |
822 | return evaluate_subexp_for_address (exp, pos, noside); | |
823 | ||
824 | case UNOP_SIZEOF: | |
825 | if (noside == EVAL_SKIP) | |
826 | { | |
827 | evaluate_subexp (0, exp, pos, EVAL_SKIP); | |
828 | goto nosideret; | |
829 | } | |
830 | return evaluate_subexp_for_sizeof (exp, pos); | |
831 | ||
832 | case UNOP_CAST: | |
833 | (*pos) += 2; | |
834 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); | |
835 | if (noside == EVAL_SKIP) | |
836 | goto nosideret; | |
837 | return value_cast (exp->elts[pc + 1].type, arg1); | |
838 | ||
839 | case UNOP_MEMVAL: | |
840 | (*pos) += 2; | |
841 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); | |
842 | if (noside == EVAL_SKIP) | |
843 | goto nosideret; | |
844 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
845 | return value_zero (exp->elts[pc + 1].type, lval_memory); | |
846 | else | |
847 | return value_at (exp->elts[pc + 1].type, | |
848 | (CORE_ADDR) value_as_long (arg1)); | |
849 | ||
850 | case UNOP_PREINCREMENT: | |
851 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); | |
852 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) | |
853 | return arg1; | |
854 | else if (unop_user_defined_p (op, arg1)) | |
855 | { | |
856 | return value_x_unop (arg1, op); | |
857 | } | |
858 | else | |
859 | { | |
860 | arg2 = value_add (arg1, value_from_long (builtin_type_char, | |
861 | (LONGEST) 1)); | |
862 | return value_assign (arg1, arg2); | |
863 | } | |
864 | ||
865 | case UNOP_PREDECREMENT: | |
866 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); | |
867 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) | |
868 | return arg1; | |
869 | else if (unop_user_defined_p (op, arg1)) | |
870 | { | |
871 | return value_x_unop (arg1, op); | |
872 | } | |
873 | else | |
874 | { | |
875 | arg2 = value_sub (arg1, value_from_long (builtin_type_char, | |
876 | (LONGEST) 1)); | |
877 | return value_assign (arg1, arg2); | |
878 | } | |
879 | ||
880 | case UNOP_POSTINCREMENT: | |
881 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); | |
882 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) | |
883 | return arg1; | |
884 | else if (unop_user_defined_p (op, arg1)) | |
885 | { | |
886 | return value_x_unop (arg1, op); | |
887 | } | |
888 | else | |
889 | { | |
890 | arg2 = value_add (arg1, value_from_long (builtin_type_char, | |
891 | (LONGEST) 1)); | |
892 | value_assign (arg1, arg2); | |
893 | return arg1; | |
894 | } | |
895 | ||
896 | case UNOP_POSTDECREMENT: | |
897 | arg1 = evaluate_subexp (expect_type, exp, pos, noside); | |
898 | if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS) | |
899 | return arg1; | |
900 | else if (unop_user_defined_p (op, arg1)) | |
901 | { | |
902 | return value_x_unop (arg1, op); | |
903 | } | |
904 | else | |
905 | { | |
906 | arg2 = value_sub (arg1, value_from_long (builtin_type_char, | |
907 | (LONGEST) 1)); | |
908 | value_assign (arg1, arg2); | |
909 | return arg1; | |
910 | } | |
911 | ||
912 | case OP_THIS: | |
913 | (*pos) += 1; | |
914 | return value_of_this (1); | |
915 | ||
916 | default: | |
917 | error ("internal error: I do not know how to evaluate what you gave me"); | |
918 | } | |
919 | ||
920 | nosideret: | |
921 | return value_from_long (builtin_type_long, (LONGEST) 1); | |
922 | } | |
923 | \f | |
924 | /* Evaluate a subexpression of EXP, at index *POS, | |
925 | and return the address of that subexpression. | |
926 | Advance *POS over the subexpression. | |
927 | If the subexpression isn't an lvalue, get an error. | |
928 | NOSIDE may be EVAL_AVOID_SIDE_EFFECTS; | |
929 | then only the type of the result need be correct. */ | |
930 | ||
931 | static value | |
932 | evaluate_subexp_for_address (exp, pos, noside) | |
933 | register struct expression *exp; | |
934 | register int *pos; | |
935 | enum noside noside; | |
936 | { | |
937 | enum exp_opcode op; | |
938 | register int pc; | |
939 | ||
940 | pc = (*pos); | |
941 | op = exp->elts[pc].opcode; | |
942 | ||
943 | switch (op) | |
944 | { | |
945 | case UNOP_IND: | |
946 | (*pos)++; | |
947 | return evaluate_subexp (0, exp, pos, noside); | |
948 | ||
949 | case UNOP_MEMVAL: | |
950 | (*pos) += 3; | |
951 | return value_cast (lookup_pointer_type (exp->elts[pc + 1].type), | |
952 | evaluate_subexp (0, exp, pos, noside)); | |
953 | ||
954 | case OP_VAR_VALUE: | |
955 | (*pos) += 3; | |
956 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
957 | { | |
958 | struct type *type = | |
959 | lookup_pointer_type (SYMBOL_TYPE (exp->elts[pc + 1].symbol)); | |
960 | enum address_class sym_class = | |
961 | SYMBOL_CLASS (exp->elts[pc + 1].symbol); | |
962 | ||
963 | if (sym_class == LOC_CONST | |
964 | || sym_class == LOC_CONST_BYTES | |
965 | || sym_class == LOC_REGISTER | |
966 | || sym_class == LOC_REGPARM) | |
967 | error ("Attempt to take address of register or constant."); | |
968 | ||
969 | return | |
970 | value_zero (type, not_lval); | |
971 | } | |
972 | else | |
973 | return locate_var_value (exp->elts[pc + 1].symbol, (CORE_ADDR) 0); | |
974 | ||
975 | default: | |
976 | if (noside == EVAL_AVOID_SIDE_EFFECTS) | |
977 | { | |
978 | value x = evaluate_subexp (0, exp, pos, noside); | |
979 | if (VALUE_LVAL (x) == lval_memory) | |
980 | return value_zero (TYPE_POINTER_TYPE (VALUE_TYPE (x)), | |
981 | not_lval); | |
982 | else | |
983 | error ("Attempt to take address of non-lval"); | |
984 | } | |
985 | return value_addr (evaluate_subexp (0, exp, pos, noside)); | |
986 | } | |
987 | } | |
988 | ||
989 | /* Evaluate like `evaluate_subexp' except coercing arrays to pointers. | |
990 | When used in contexts where arrays will be coerced anyway, | |
991 | this is equivalent to `evaluate_subexp' | |
992 | but much faster because it avoids actually fetching array contents. */ | |
993 | ||
994 | static value | |
995 | evaluate_subexp_with_coercion (exp, pos, noside) | |
996 | register struct expression *exp; | |
997 | register int *pos; | |
998 | enum noside noside; | |
999 | { | |
1000 | register enum exp_opcode op; | |
1001 | register int pc; | |
1002 | register value val; | |
1003 | ||
1004 | pc = (*pos); | |
1005 | op = exp->elts[pc].opcode; | |
1006 | ||
1007 | switch (op) | |
1008 | { | |
1009 | case OP_VAR_VALUE: | |
1010 | if (TYPE_CODE (SYMBOL_TYPE (exp->elts[pc + 1].symbol)) == TYPE_CODE_ARRAY) | |
1011 | { | |
1012 | (*pos) += 3; | |
1013 | val = locate_var_value (exp->elts[pc + 1].symbol, (CORE_ADDR) 0); | |
1014 | return value_cast (lookup_pointer_type (TYPE_TARGET_TYPE (SYMBOL_TYPE (exp->elts[pc + 1].symbol))), | |
1015 | val); | |
1016 | } | |
1017 | } | |
1018 | ||
1019 | return evaluate_subexp (0, exp, pos, noside); | |
1020 | } | |
1021 | ||
1022 | /* Evaluate a subexpression of EXP, at index *POS, | |
1023 | and return a value for the size of that subexpression. | |
1024 | Advance *POS over the subexpression. */ | |
1025 | ||
1026 | static value | |
1027 | evaluate_subexp_for_sizeof (exp, pos) | |
1028 | register struct expression *exp; | |
1029 | register int *pos; | |
1030 | { | |
1031 | enum exp_opcode op; | |
1032 | register int pc; | |
1033 | value val; | |
1034 | ||
1035 | pc = (*pos); | |
1036 | op = exp->elts[pc].opcode; | |
1037 | ||
1038 | switch (op) | |
1039 | { | |
1040 | /* This case is handled specially | |
1041 | so that we avoid creating a value for the result type. | |
1042 | If the result type is very big, it's desirable not to | |
1043 | create a value unnecessarily. */ | |
1044 | case UNOP_IND: | |
1045 | (*pos)++; | |
1046 | val = evaluate_subexp (0, exp, pos, EVAL_AVOID_SIDE_EFFECTS); | |
1047 | return value_from_long (builtin_type_int, (LONGEST) | |
1048 | TYPE_LENGTH (TYPE_TARGET_TYPE (VALUE_TYPE (val)))); | |
1049 | ||
1050 | case UNOP_MEMVAL: | |
1051 | (*pos) += 3; | |
1052 | return value_from_long (builtin_type_int, | |
1053 | (LONGEST) TYPE_LENGTH (exp->elts[pc + 1].type)); | |
1054 | ||
1055 | case OP_VAR_VALUE: | |
1056 | (*pos) += 3; | |
1057 | return value_from_long (builtin_type_int, | |
1058 | (LONGEST) TYPE_LENGTH (SYMBOL_TYPE (exp->elts[pc + 1].symbol))); | |
1059 | ||
1060 | default: | |
1061 | val = evaluate_subexp (0, exp, pos, EVAL_AVOID_SIDE_EFFECTS); | |
1062 | return value_from_long (builtin_type_int, | |
1063 | (LONGEST) TYPE_LENGTH (VALUE_TYPE (val))); | |
1064 | } | |
1065 | } |