1 /* Evaluate expressions for GDB.
2 Copyright 1986, 1987, 1989, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GDB.
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.
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.
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. */
24 #include "expression.h"
28 /* Values of NOSIDE argument to eval_subexp. */
31 EVAL_SKIP, /* Only effect is to increment pos. */
32 EVAL_AVOID_SIDE_EFFECTS /* Don't modify any variables or
33 call any functions. The value
34 returned will have the correct
35 type, and will have an
36 approximately correct lvalue
37 type (inaccuracy: anything that is
38 listed as being in a register in
39 the function in which it was
40 declared will be lval_register). */
43 /* Prototypes for local functions. */
46 evaluate_subexp_for_sizeof PARAMS ((struct expression *, int *));
49 evaluate_subexp_with_coercion PARAMS ((struct expression *, int *,
53 evaluate_subexp_for_address PARAMS ((struct expression *, int *,
57 evaluate_subexp PARAMS ((struct type *, struct expression *, int *,
61 /* Parse the string EXP as a C expression, evaluate it,
62 and return the result as a number. */
65 parse_and_eval_address (exp)
68 struct expression *expr = parse_expression (exp);
69 register CORE_ADDR addr;
70 register struct cleanup *old_chain =
71 make_cleanup (free_current_contents, &expr);
73 addr = value_as_pointer (evaluate_expression (expr));
74 do_cleanups (old_chain);
78 /* Like parse_and_eval_address but takes a pointer to a char * variable
79 and advanced that variable across the characters parsed. */
82 parse_and_eval_address_1 (expptr)
85 struct expression *expr = parse_exp_1 (expptr, (struct block *)0, 0);
86 register CORE_ADDR addr;
87 register struct cleanup *old_chain =
88 make_cleanup (free_current_contents, &expr);
90 addr = value_as_pointer (evaluate_expression (expr));
91 do_cleanups (old_chain);
99 struct expression *expr = parse_expression (exp);
101 register struct cleanup *old_chain
102 = make_cleanup (free_current_contents, &expr);
104 val = evaluate_expression (expr);
105 do_cleanups (old_chain);
109 /* Parse up to a comma (or to a closeparen)
110 in the string EXPP as an expression, evaluate it, and return the value.
111 EXPP is advanced to point to the comma. */
114 parse_to_comma_and_eval (expp)
117 struct expression *expr = parse_exp_1 (expp, (struct block *) 0, 1);
119 register struct cleanup *old_chain
120 = make_cleanup (free_current_contents, &expr);
122 val = evaluate_expression (expr);
123 do_cleanups (old_chain);
127 /* Evaluate an expression in internal prefix form
128 such as is constructed by parse.y.
130 See expression.h for info on the format of an expression. */
132 static value evaluate_subexp ();
133 static value evaluate_subexp_for_address ();
134 static value evaluate_subexp_for_sizeof ();
135 static value evaluate_subexp_with_coercion ();
138 evaluate_expression (exp)
139 struct expression *exp;
142 return evaluate_subexp (NULL_TYPE, exp, &pc, EVAL_NORMAL);
145 /* Evaluate an expression, avoiding all memory references
146 and getting a value whose type alone is correct. */
150 struct expression *exp;
153 return evaluate_subexp (NULL_TYPE, exp, &pc, EVAL_AVOID_SIDE_EFFECTS);
157 evaluate_subexp (expect_type, exp, pos, noside)
158 struct type *expect_type;
159 register struct expression *exp;
165 register int pc, pc2, oldpos;
166 register value arg1, arg2, arg3;
172 op = exp->elts[pc].opcode;
177 tem = strlen (&exp->elts[pc + 2].string);
178 (*pos) += 3 + ((tem + sizeof (union exp_element))
179 / sizeof (union exp_element));
180 arg1 = value_struct_elt_for_reference (exp->elts[pc + 1].type,
182 exp->elts[pc + 1].type,
183 &exp->elts[pc + 2].string,
186 error ("There is no field named %s", &exp->elts[pc + 2].string);
191 return value_from_longest (exp->elts[pc + 1].type,
192 exp->elts[pc + 2].longconst);
196 return value_from_double (exp->elts[pc + 1].type,
197 exp->elts[pc + 2].doubleconst);
201 if (noside == EVAL_SKIP)
203 if (noside == EVAL_AVOID_SIDE_EFFECTS)
205 struct symbol * sym = exp->elts[pc + 1].symbol;
208 switch (SYMBOL_CLASS (sym))
212 case LOC_CONST_BYTES:
226 return value_zero (SYMBOL_TYPE (sym), lv);
229 return value_of_variable (exp->elts[pc + 1].symbol);
234 access_value_history (longest_to_int (exp->elts[pc + 1].longconst));
238 return value_of_register (longest_to_int (exp->elts[pc + 1].longconst));
242 return value_of_internalvar (exp->elts[pc + 1].internalvar);
245 tem = strlen (&exp->elts[pc + 1].string);
246 (*pos) += 2 + ((tem + sizeof (union exp_element))
247 / sizeof (union exp_element));
248 if (noside == EVAL_SKIP)
250 return value_string (&exp->elts[pc + 1].string, tem);
253 /* Skip third and second args to evaluate the first one. */
254 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
255 if (value_zerop (arg1))
257 evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP);
258 return evaluate_subexp (NULL_TYPE, exp, pos, noside);
262 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
263 evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP);
269 op = exp->elts[*pos].opcode;
270 if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR)
274 nargs = longest_to_int (exp->elts[pc + 1].longconst) + 1;
275 /* First, evaluate the structure into arg2 */
278 if (noside == EVAL_SKIP)
281 if (op == STRUCTOP_MEMBER)
283 arg2 = evaluate_subexp_for_address (exp, pos, noside);
287 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
290 /* If the function is a virtual function, then the
291 aggregate value (providing the structure) plays
292 its part by providing the vtable. Otherwise,
293 it is just along for the ride: call the function
296 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
298 fnptr = longest_to_int (value_as_long (arg1));
300 if (METHOD_PTR_IS_VIRTUAL(fnptr))
302 int fnoffset = METHOD_PTR_TO_VOFFSET(fnptr);
303 struct type *basetype;
304 struct type *domain_type =
305 TYPE_DOMAIN_TYPE (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)));
307 basetype = TYPE_TARGET_TYPE (VALUE_TYPE (arg2));
308 if (domain_type != basetype)
309 arg2 = value_cast(lookup_pointer_type (domain_type), arg2);
310 basetype = TYPE_VPTR_BASETYPE (domain_type);
311 for (i = TYPE_NFN_FIELDS (basetype) - 1; i >= 0; i--)
313 struct fn_field *f = TYPE_FN_FIELDLIST1 (basetype, i);
314 /* If one is virtual, then all are virtual. */
315 if (TYPE_FN_FIELD_VIRTUAL_P (f, 0))
316 for (j = TYPE_FN_FIELDLIST_LENGTH (basetype, i) - 1; j >= 0; --j)
317 if (TYPE_FN_FIELD_VOFFSET (f, j) == fnoffset)
319 value temp = value_ind (arg2);
320 arg1 = value_virtual_fn_field (&temp, f, j, domain_type, 0);
321 arg2 = value_addr (temp);
326 error ("virtual function at index %d not found", fnoffset);
330 VALUE_TYPE (arg1) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)));
334 /* Now, say which argument to start evaluating from */
337 else if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR)
339 /* Hair for method invocations */
342 nargs = longest_to_int (exp->elts[pc + 1].longconst) + 1;
343 /* First, evaluate the structure into arg2 */
345 /* type = exp->elts[pc2 + 1].type; */
346 tem2 = strlen (&exp->elts[pc2 + 2].string);
347 *pos += 3 + (tem2 + sizeof (union exp_element)) / sizeof (union exp_element);
348 if (noside == EVAL_SKIP)
351 if (op == STRUCTOP_STRUCT)
353 arg2 = evaluate_subexp_for_address (exp, pos, noside);
357 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
359 /* Now, say which argument to start evaluating from */
364 nargs = longest_to_int (exp->elts[pc + 1].longconst);
367 argvec = (value *) alloca (sizeof (value) * (nargs + 2));
368 for (; tem <= nargs; tem++)
369 /* Ensure that array expressions are coerced into pointer objects. */
370 argvec[tem] = evaluate_subexp_with_coercion (exp, pos, noside);
372 /* signal end of arglist */
375 if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR)
380 /* argvec[0] gets the method;
381 argvec[1] gets the 'this' pointer (unless static) (from arg2);
382 the remaining args go into the rest of argvec. */
386 value_struct_elt (&temp, argvec+1, &exp->elts[pc2 + 2].string,
388 op == STRUCTOP_STRUCT
389 ? "structure" : "structure pointer");
390 if (VALUE_OFFSET (temp))
392 arg2 = value_from_longest (lookup_pointer_type (VALUE_TYPE (temp)),
393 value_as_long (arg2)+VALUE_OFFSET (temp));
398 argvec[1] = argvec[0];
403 else if (op == STRUCTOP_MEMBER || op == STRUCTOP_MPTR)
409 if (noside == EVAL_SKIP)
411 if (noside == EVAL_AVOID_SIDE_EFFECTS)
413 /* If the return type doesn't look like a function type, call an
414 error. This can happen if somebody tries to turn a variable into
415 a function call. This is here because people often want to
416 call, eg, strcmp, which gdb doesn't know is a function. If
417 gdb isn't asked for it's opinion (ie. through "whatis"),
418 it won't offer it. */
421 TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0]));
424 return allocate_value (TYPE_TARGET_TYPE (VALUE_TYPE (argvec[0])));
426 error ("Expression of type other than \"Function returning ...\" used as function");
428 return call_function_by_hand (argvec[0], nargs, argvec + 1);
430 case STRUCTOP_STRUCT:
431 tem = strlen (&exp->elts[pc + 2].string);
432 (*pos) += 3 + ((tem + sizeof (union exp_element))
433 / sizeof (union exp_element));
434 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
435 if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR)
436 goto handle_structop_ptr;
437 type = exp->elts[pc + 1].type;
439 arg1 = value_ind (value_cast (lookup_pointer_type (type),
441 if (noside == EVAL_SKIP)
443 if (noside == EVAL_AVOID_SIDE_EFFECTS)
444 return value_zero (lookup_struct_elt_type (VALUE_TYPE (arg1),
445 &exp->elts[pc + 2].string,
451 return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 2].string,
452 (int *) 0, "structure");
456 tem = strlen (&exp->elts[pc + 2].string);
457 (*pos) += 3 + (tem + sizeof (union exp_element)) / sizeof (union exp_element);
458 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
460 type = exp->elts[pc + 1].type;
462 arg1 = value_cast (lookup_pointer_type (type), arg1);
463 if (noside == EVAL_SKIP)
465 if (noside == EVAL_AVOID_SIDE_EFFECTS)
466 return value_zero (lookup_struct_elt_type (TYPE_TARGET_TYPE
468 &exp->elts[pc + 2].string,
474 return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 2].string,
475 (int *) 0, "structure pointer");
478 case STRUCTOP_MEMBER:
479 arg1 = evaluate_subexp_for_address (exp, pos, noside);
480 goto handle_pointer_to_member;
482 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
483 handle_pointer_to_member:
484 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
485 if (noside == EVAL_SKIP)
487 if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_PTR)
488 goto bad_pointer_to_member;
489 type = TYPE_TARGET_TYPE (VALUE_TYPE (arg2));
490 if (TYPE_CODE (type) == TYPE_CODE_METHOD)
491 error ("not implemented: pointer-to-method in pointer-to-member construct");
492 if (TYPE_CODE (type) != TYPE_CODE_MEMBER)
493 goto bad_pointer_to_member;
494 /* Now, convert these values to an address. */
495 arg1 = value_cast (lookup_pointer_type (TYPE_DOMAIN_TYPE (type)),
497 arg3 = value_from_longest (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
498 value_as_long (arg1) + value_as_long (arg2));
499 return value_ind (arg3);
500 bad_pointer_to_member:
501 error("non-pointer-to-member value used in pointer-to-member construct");
504 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
505 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
506 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
508 if (binop_user_defined_p (op, arg1, arg2))
509 return value_x_binop (arg1, arg2, op, OP_NULL);
511 return value_assign (arg1, arg2);
513 case BINOP_ASSIGN_MODIFY:
515 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
516 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
517 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
519 op = exp->elts[pc + 1].opcode;
520 if (binop_user_defined_p (op, arg1, arg2))
521 return value_x_binop (arg1, arg2, BINOP_ASSIGN_MODIFY, op);
522 else if (op == BINOP_ADD)
523 arg2 = value_add (arg1, arg2);
524 else if (op == BINOP_SUB)
525 arg2 = value_sub (arg1, arg2);
527 arg2 = value_binop (arg1, arg2, op);
528 return value_assign (arg1, arg2);
531 arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
532 arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
533 if (noside == EVAL_SKIP)
535 if (binop_user_defined_p (op, arg1, arg2))
536 return value_x_binop (arg1, arg2, op, OP_NULL);
538 return value_add (arg1, arg2);
541 arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
542 arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
543 if (noside == EVAL_SKIP)
545 if (binop_user_defined_p (op, arg1, arg2))
546 return value_x_binop (arg1, arg2, op, OP_NULL);
548 return value_sub (arg1, arg2);
558 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
559 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
560 if (noside == EVAL_SKIP)
562 if (binop_user_defined_p (op, arg1, arg2))
563 return value_x_binop (arg1, arg2, op, OP_NULL);
565 if (noside == EVAL_AVOID_SIDE_EFFECTS
566 && (op == BINOP_DIV || op == BINOP_REM))
567 return value_zero (VALUE_TYPE (arg1), not_lval);
569 return value_binop (arg1, arg2, op);
571 case BINOP_SUBSCRIPT:
572 arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
573 arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
574 if (noside == EVAL_SKIP)
576 if (noside == EVAL_AVOID_SIDE_EFFECTS)
578 /* If the user attempts to subscript something that has no target
579 type (like a plain int variable for example), then report this
582 type = TYPE_TARGET_TYPE (VALUE_TYPE (arg1));
584 return value_zero (type, VALUE_LVAL (arg1));
586 error ("cannot subscript something of type `%s'",
587 TYPE_NAME (VALUE_TYPE (arg1)));
590 if (binop_user_defined_p (op, arg1, arg2))
591 return value_x_binop (arg1, arg2, op, OP_NULL);
593 return value_subscript (arg1, arg2);
596 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
597 if (noside == EVAL_SKIP)
599 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
604 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
607 if (binop_user_defined_p (op, arg1, arg2))
609 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
610 return value_x_binop (arg1, arg2, op, OP_NULL);
614 tem = value_zerop (arg1);
615 arg2 = evaluate_subexp (NULL_TYPE, exp, pos,
616 (tem ? EVAL_SKIP : noside));
617 return value_from_longest (builtin_type_int,
618 (LONGEST) (!tem && !value_zerop (arg2)));
622 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
623 if (noside == EVAL_SKIP)
625 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
630 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
633 if (binop_user_defined_p (op, arg1, arg2))
635 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
636 return value_x_binop (arg1, arg2, op, OP_NULL);
640 tem = value_zerop (arg1);
641 arg2 = evaluate_subexp (NULL_TYPE, exp, pos,
642 (!tem ? EVAL_SKIP : noside));
643 return value_from_longest (builtin_type_int,
644 (LONGEST) (!tem || !value_zerop (arg2)));
648 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
649 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
650 if (noside == EVAL_SKIP)
652 if (binop_user_defined_p (op, arg1, arg2))
654 return value_x_binop (arg1, arg2, op, OP_NULL);
658 tem = value_equal (arg1, arg2);
659 return value_from_longest (builtin_type_int, (LONGEST) tem);
663 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
664 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
665 if (noside == EVAL_SKIP)
667 if (binop_user_defined_p (op, arg1, arg2))
669 return value_x_binop (arg1, arg2, op, OP_NULL);
673 tem = value_equal (arg1, arg2);
674 return value_from_longest (builtin_type_int, (LONGEST) ! tem);
678 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
679 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
680 if (noside == EVAL_SKIP)
682 if (binop_user_defined_p (op, arg1, arg2))
684 return value_x_binop (arg1, arg2, op, OP_NULL);
688 tem = value_less (arg1, arg2);
689 return value_from_longest (builtin_type_int, (LONGEST) tem);
693 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
694 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
695 if (noside == EVAL_SKIP)
697 if (binop_user_defined_p (op, arg1, arg2))
699 return value_x_binop (arg1, arg2, op, OP_NULL);
703 tem = value_less (arg2, arg1);
704 return value_from_longest (builtin_type_int, (LONGEST) tem);
708 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
709 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
710 if (noside == EVAL_SKIP)
712 if (binop_user_defined_p (op, arg1, arg2))
714 return value_x_binop (arg1, arg2, op, OP_NULL);
718 tem = value_less (arg2, arg1) || value_equal (arg1, arg2);
719 return value_from_longest (builtin_type_int, (LONGEST) tem);
723 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
724 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
725 if (noside == EVAL_SKIP)
727 if (binop_user_defined_p (op, arg1, arg2))
729 return value_x_binop (arg1, arg2, op, OP_NULL);
733 tem = value_less (arg1, arg2) || value_equal (arg1, arg2);
734 return value_from_longest (builtin_type_int, (LONGEST) tem);
738 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
739 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
740 if (noside == EVAL_SKIP)
742 if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_INT)
743 error ("Non-integral right operand for \"@\" operator.");
744 if (noside == EVAL_AVOID_SIDE_EFFECTS)
745 return allocate_repeat_value (VALUE_TYPE (arg1),
746 longest_to_int (value_as_long (arg2)));
748 return value_repeat (arg1, longest_to_int (value_as_long (arg2)));
751 evaluate_subexp (NULL_TYPE, exp, pos, noside);
752 return evaluate_subexp (NULL_TYPE, exp, pos, noside);
755 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
756 if (noside == EVAL_SKIP)
758 if (unop_user_defined_p (op, arg1))
759 return value_x_unop (arg1, op);
761 return value_neg (arg1);
764 /* C++: check for and handle destructor names. */
765 op = exp->elts[*pos].opcode;
767 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
768 if (noside == EVAL_SKIP)
770 if (unop_user_defined_p (UNOP_LOGNOT, arg1))
771 return value_x_unop (arg1, UNOP_LOGNOT);
773 return value_lognot (arg1);
776 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
777 if (noside == EVAL_SKIP)
779 if (unop_user_defined_p (op, arg1))
780 return value_x_unop (arg1, op);
782 return value_from_longest (builtin_type_int,
783 (LONGEST) value_zerop (arg1));
786 if (expect_type && TYPE_CODE (expect_type) == TYPE_CODE_PTR)
787 expect_type = TYPE_TARGET_TYPE (expect_type);
788 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
789 if (noside == EVAL_SKIP)
791 if (noside == EVAL_AVOID_SIDE_EFFECTS)
793 if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR
794 || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_REF
795 /* In C you can dereference an array to get the 1st elt. */
796 || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_ARRAY
798 return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)),
800 else if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_INT)
801 /* GDB allows dereferencing an int. */
802 return value_zero (builtin_type_int, lval_memory);
804 error ("Attempt to take contents of a non-pointer value.");
806 return value_ind (arg1);
809 /* C++: check for and handle pointer to members. */
811 op = exp->elts[*pos].opcode;
813 if (noside == EVAL_SKIP)
817 char *name = &exp->elts[pc+3].string;
818 int temm = strlen (name);
819 (*pos) += 2 + (temm + sizeof (union exp_element)) / sizeof (union exp_element);
822 evaluate_subexp (expect_type, exp, pos, EVAL_SKIP);
826 return evaluate_subexp_for_address (exp, pos, noside);
829 if (noside == EVAL_SKIP)
831 evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP);
834 return evaluate_subexp_for_sizeof (exp, pos);
838 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
839 if (noside == EVAL_SKIP)
841 return value_cast (exp->elts[pc + 1].type, arg1);
845 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
846 if (noside == EVAL_SKIP)
848 if (noside == EVAL_AVOID_SIDE_EFFECTS)
849 return value_zero (exp->elts[pc + 1].type, lval_memory);
851 return value_at_lazy (exp->elts[pc + 1].type,
852 value_as_pointer (arg1));
854 case UNOP_PREINCREMENT:
855 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
856 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
858 else if (unop_user_defined_p (op, arg1))
860 return value_x_unop (arg1, op);
864 arg2 = value_add (arg1, value_from_longest (builtin_type_char,
866 return value_assign (arg1, arg2);
869 case UNOP_PREDECREMENT:
870 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
871 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
873 else if (unop_user_defined_p (op, arg1))
875 return value_x_unop (arg1, op);
879 arg2 = value_sub (arg1, value_from_longest (builtin_type_char,
881 return value_assign (arg1, arg2);
884 case UNOP_POSTINCREMENT:
885 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
886 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
888 else if (unop_user_defined_p (op, arg1))
890 return value_x_unop (arg1, op);
894 arg2 = value_add (arg1, value_from_longest (builtin_type_char,
896 value_assign (arg1, arg2);
900 case UNOP_POSTDECREMENT:
901 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
902 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
904 else if (unop_user_defined_p (op, arg1))
906 return value_x_unop (arg1, op);
910 arg2 = value_sub (arg1, value_from_longest (builtin_type_char,
912 value_assign (arg1, arg2);
918 return value_of_this (1);
921 error ("internal error: I do not know how to evaluate what you gave me");
925 return value_from_longest (builtin_type_long, (LONGEST) 1);
928 /* Evaluate a subexpression of EXP, at index *POS,
929 and return the address of that subexpression.
930 Advance *POS over the subexpression.
931 If the subexpression isn't an lvalue, get an error.
932 NOSIDE may be EVAL_AVOID_SIDE_EFFECTS;
933 then only the type of the result need be correct. */
936 evaluate_subexp_for_address (exp, pos, noside)
937 register struct expression *exp;
946 op = exp->elts[pc].opcode;
952 return evaluate_subexp (NULL_TYPE, exp, pos, noside);
956 return value_cast (lookup_pointer_type (exp->elts[pc + 1].type),
957 evaluate_subexp (NULL_TYPE, exp, pos, noside));
960 var = exp->elts[pc + 1].symbol;
962 /* C++: The "address" of a reference should yield the address
963 * of the object pointed to. Let value_addr() deal with it. */
964 if (TYPE_CODE (SYMBOL_TYPE (var)) == TYPE_CODE_REF)
968 if (noside == EVAL_AVOID_SIDE_EFFECTS)
971 lookup_pointer_type (SYMBOL_TYPE (var));
972 enum address_class sym_class = SYMBOL_CLASS (var);
974 if (sym_class == LOC_CONST
975 || sym_class == LOC_CONST_BYTES
976 || sym_class == LOC_REGISTER
977 || sym_class == LOC_REGPARM)
978 error ("Attempt to take address of register or constant.");
981 value_zero (type, not_lval);
984 return locate_var_value (var, (FRAME) 0);
988 if (noside == EVAL_AVOID_SIDE_EFFECTS)
990 value x = evaluate_subexp (NULL_TYPE, exp, pos, noside);
991 if (VALUE_LVAL (x) == lval_memory)
992 return value_zero (lookup_pointer_type (VALUE_TYPE (x)),
995 error ("Attempt to take address of non-lval");
997 return value_addr (evaluate_subexp (NULL_TYPE, exp, pos, noside));
1001 /* Evaluate like `evaluate_subexp' except coercing arrays to pointers.
1002 When used in contexts where arrays will be coerced anyway,
1003 this is equivalent to `evaluate_subexp'
1004 but much faster because it avoids actually fetching array contents. */
1007 evaluate_subexp_with_coercion (exp, pos, noside)
1008 register struct expression *exp;
1012 register enum exp_opcode op;
1018 op = exp->elts[pc].opcode;
1023 var = exp->elts[pc + 1].symbol;
1024 if (TYPE_CODE (SYMBOL_TYPE (var)) == TYPE_CODE_ARRAY)
1027 val = locate_var_value (var, (FRAME) 0);
1028 return value_cast (lookup_pointer_type (TYPE_TARGET_TYPE (SYMBOL_TYPE (var))),
1032 return evaluate_subexp (NULL_TYPE, exp, pos, noside);
1036 /* Evaluate a subexpression of EXP, at index *POS,
1037 and return a value for the size of that subexpression.
1038 Advance *POS over the subexpression. */
1041 evaluate_subexp_for_sizeof (exp, pos)
1042 register struct expression *exp;
1050 op = exp->elts[pc].opcode;
1054 /* This case is handled specially
1055 so that we avoid creating a value for the result type.
1056 If the result type is very big, it's desirable not to
1057 create a value unnecessarily. */
1060 val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
1061 return value_from_longest (builtin_type_int, (LONGEST)
1062 TYPE_LENGTH (TYPE_TARGET_TYPE (VALUE_TYPE (val))));
1066 return value_from_longest (builtin_type_int,
1067 (LONGEST) TYPE_LENGTH (exp->elts[pc + 1].type));
1071 return value_from_longest (builtin_type_int,
1072 (LONGEST) TYPE_LENGTH (SYMBOL_TYPE (exp->elts[pc + 1].symbol)));
1075 val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
1076 return value_from_longest (builtin_type_int,
1077 (LONGEST) TYPE_LENGTH (VALUE_TYPE (val)));
1081 /* Parse a type expression in the string [P..P+LENGTH). */
1084 parse_and_eval_type (p, length)
1088 char *tmp = (char *)alloca (length + 4);
1089 struct expression *expr;
1091 memcpy (tmp+1, p, length);
1092 tmp[length+1] = ')';
1093 tmp[length+2] = '0';
1094 tmp[length+3] = '\0';
1095 expr = parse_expression (tmp);
1096 if (expr->elts[0].opcode != UNOP_CAST)
1097 error ("Internal error in eval_type.");
1098 return expr->elts[1].type;