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));
299 /* FIXME-tiemann: this is way obsolete. */
302 struct type *basetype;
304 basetype = TYPE_TARGET_TYPE (VALUE_TYPE (arg2));
305 basetype = TYPE_VPTR_BASETYPE (basetype);
306 for (i = TYPE_NFN_FIELDS (basetype) - 1; i >= 0; i--)
308 struct fn_field *f = TYPE_FN_FIELDLIST1 (basetype, i);
309 /* If one is virtual, then all are virtual. */
310 if (TYPE_FN_FIELD_VIRTUAL_P (f, 0))
311 for (j = TYPE_FN_FIELDLIST_LENGTH (basetype, i) - 1; j >= 0; --j)
312 if (TYPE_FN_FIELD_VOFFSET (f, j) == fnptr)
315 value base = value_ind (arg2);
316 struct type *fntype = lookup_pointer_type (TYPE_FN_FIELD_TYPE (f, j));
318 if (TYPE_VPTR_FIELDNO (basetype) < 0)
319 fill_in_vptr_fieldno (basetype);
321 VALUE_TYPE (base) = basetype;
322 vtbl = value_field (base, TYPE_VPTR_FIELDNO (basetype));
323 VALUE_TYPE (vtbl) = lookup_pointer_type (fntype);
324 VALUE_TYPE (arg1) = builtin_type_int;
325 arg1 = value_subscript (vtbl, arg1);
326 VALUE_TYPE (arg1) = fntype;
331 error ("virtual function at index %d not found", fnptr);
335 VALUE_TYPE (arg1) = lookup_pointer_type (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)));
339 /* Now, say which argument to start evaluating from */
342 else if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR)
344 /* Hair for method invocations */
347 nargs = longest_to_int (exp->elts[pc + 1].longconst) + 1;
348 /* First, evaluate the structure into arg2 */
350 tem2 = strlen (&exp->elts[pc2 + 1].string);
351 *pos += 2 + (tem2 + sizeof (union exp_element)) / sizeof (union exp_element);
352 if (noside == EVAL_SKIP)
355 if (op == STRUCTOP_STRUCT)
357 arg2 = evaluate_subexp_for_address (exp, pos, noside);
361 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
363 /* Now, say which argument to start evaluating from */
368 nargs = longest_to_int (exp->elts[pc + 1].longconst);
371 argvec = (value *) alloca (sizeof (value) * (nargs + 2));
372 for (; tem <= nargs; tem++)
373 /* Ensure that array expressions are coerced into pointer objects. */
374 argvec[tem] = evaluate_subexp_with_coercion (exp, pos, noside);
376 /* signal end of arglist */
379 if (op == STRUCTOP_STRUCT || op == STRUCTOP_PTR)
386 value_struct_elt (&temp, argvec+1, &exp->elts[pc2 + 1].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 + 1].string);
432 (*pos) += 2 + ((tem + sizeof (union exp_element))
433 / sizeof (union exp_element));
434 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
435 if (noside == EVAL_SKIP)
437 if (noside == EVAL_AVOID_SIDE_EFFECTS)
438 return value_zero (lookup_struct_elt_type (VALUE_TYPE (arg1),
439 &exp->elts[pc + 1].string,
445 return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 1].string,
446 (int *) 0, "structure");
450 tem = strlen (&exp->elts[pc + 1].string);
451 (*pos) += 2 + (tem + sizeof (union exp_element)) / sizeof (union exp_element);
452 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
453 if (noside == EVAL_SKIP)
455 if (noside == EVAL_AVOID_SIDE_EFFECTS)
456 return value_zero (lookup_struct_elt_type (TYPE_TARGET_TYPE
458 &exp->elts[pc + 1].string,
464 return value_struct_elt (&temp, (value *)0, &exp->elts[pc + 1].string,
465 (int *) 0, "structure pointer");
468 case STRUCTOP_MEMBER:
469 arg1 = evaluate_subexp_for_address (exp, pos, noside);
470 goto handle_pointer_to_member;
472 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
473 handle_pointer_to_member:
474 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
475 if (noside == EVAL_SKIP)
477 if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_PTR)
478 goto bad_pointer_to_member;
479 type = TYPE_TARGET_TYPE (VALUE_TYPE (arg2));
480 if (TYPE_CODE (type) == TYPE_CODE_METHOD)
481 error ("not implemented: pointer-to-method in pointer-to-member construct");
482 if (TYPE_CODE (type) != TYPE_CODE_MEMBER)
483 goto bad_pointer_to_member;
484 /* Now, convert these values to an address. */
485 arg1 = value_cast (lookup_pointer_type (TYPE_DOMAIN_TYPE (type)),
487 arg3 = value_from_longest (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
488 value_as_long (arg1) + value_as_long (arg2));
489 return value_ind (arg3);
490 bad_pointer_to_member:
491 error("non-pointer-to-member value used in pointer-to-member construct");
494 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
495 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
496 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
498 if (binop_user_defined_p (op, arg1, arg2))
499 return value_x_binop (arg1, arg2, op, OP_NULL);
501 return value_assign (arg1, arg2);
503 case BINOP_ASSIGN_MODIFY:
505 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
506 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
507 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
509 op = exp->elts[pc + 1].opcode;
510 if (binop_user_defined_p (op, arg1, arg2))
511 return value_x_binop (arg1, arg2, BINOP_ASSIGN_MODIFY, op);
512 else if (op == BINOP_ADD)
513 arg2 = value_add (arg1, arg2);
514 else if (op == BINOP_SUB)
515 arg2 = value_sub (arg1, arg2);
517 arg2 = value_binop (arg1, arg2, op);
518 return value_assign (arg1, arg2);
521 arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
522 arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
523 if (noside == EVAL_SKIP)
525 if (binop_user_defined_p (op, arg1, arg2))
526 return value_x_binop (arg1, arg2, op, OP_NULL);
528 return value_add (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_sub (arg1, arg2);
548 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
549 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
550 if (noside == EVAL_SKIP)
552 if (binop_user_defined_p (op, arg1, arg2))
553 return value_x_binop (arg1, arg2, op, OP_NULL);
555 if (noside == EVAL_AVOID_SIDE_EFFECTS
556 && (op == BINOP_DIV || op == BINOP_REM))
557 return value_zero (VALUE_TYPE (arg1), not_lval);
559 return value_binop (arg1, arg2, op);
561 case BINOP_SUBSCRIPT:
562 arg1 = evaluate_subexp_with_coercion (exp, pos, noside);
563 arg2 = evaluate_subexp_with_coercion (exp, pos, noside);
564 if (noside == EVAL_SKIP)
566 if (noside == EVAL_AVOID_SIDE_EFFECTS)
567 return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)),
570 if (binop_user_defined_p (op, arg1, arg2))
571 return value_x_binop (arg1, arg2, op, OP_NULL);
573 return value_subscript (arg1, arg2);
576 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
577 if (noside == EVAL_SKIP)
579 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
584 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
587 if (binop_user_defined_p (op, arg1, arg2))
589 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
590 return value_x_binop (arg1, arg2, op, OP_NULL);
594 tem = value_zerop (arg1);
595 arg2 = evaluate_subexp (NULL_TYPE, exp, pos,
596 (tem ? EVAL_SKIP : noside));
597 return value_from_longest (builtin_type_int,
598 (LONGEST) (!tem && !value_zerop (arg2)));
602 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
603 if (noside == EVAL_SKIP)
605 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
610 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
613 if (binop_user_defined_p (op, arg1, arg2))
615 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
616 return value_x_binop (arg1, arg2, op, OP_NULL);
620 tem = value_zerop (arg1);
621 arg2 = evaluate_subexp (NULL_TYPE, exp, pos,
622 (!tem ? EVAL_SKIP : noside));
623 return value_from_longest (builtin_type_int,
624 (LONGEST) (!tem || !value_zerop (arg2)));
628 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
629 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
630 if (noside == EVAL_SKIP)
632 if (binop_user_defined_p (op, arg1, arg2))
634 return value_x_binop (arg1, arg2, op, OP_NULL);
638 tem = value_equal (arg1, arg2);
639 return value_from_longest (builtin_type_int, (LONGEST) tem);
643 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
644 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
645 if (noside == EVAL_SKIP)
647 if (binop_user_defined_p (op, arg1, arg2))
649 return value_x_binop (arg1, arg2, op, OP_NULL);
653 tem = value_equal (arg1, arg2);
654 return value_from_longest (builtin_type_int, (LONGEST) ! tem);
658 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
659 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
660 if (noside == EVAL_SKIP)
662 if (binop_user_defined_p (op, arg1, arg2))
664 return value_x_binop (arg1, arg2, op, OP_NULL);
668 tem = value_less (arg1, arg2);
669 return value_from_longest (builtin_type_int, (LONGEST) tem);
673 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
674 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
675 if (noside == EVAL_SKIP)
677 if (binop_user_defined_p (op, arg1, arg2))
679 return value_x_binop (arg1, arg2, op, OP_NULL);
683 tem = value_less (arg2, arg1);
684 return value_from_longest (builtin_type_int, (LONGEST) tem);
688 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
689 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
690 if (noside == EVAL_SKIP)
692 if (binop_user_defined_p (op, arg1, arg2))
694 return value_x_binop (arg1, arg2, op, OP_NULL);
698 tem = value_less (arg2, arg1) || value_equal (arg1, arg2);
699 return value_from_longest (builtin_type_int, (LONGEST) tem);
703 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
704 arg2 = evaluate_subexp (VALUE_TYPE (arg1), exp, pos, noside);
705 if (noside == EVAL_SKIP)
707 if (binop_user_defined_p (op, arg1, arg2))
709 return value_x_binop (arg1, arg2, op, OP_NULL);
713 tem = value_less (arg1, arg2) || value_equal (arg1, arg2);
714 return value_from_longest (builtin_type_int, (LONGEST) tem);
718 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
719 arg2 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
720 if (noside == EVAL_SKIP)
722 if (TYPE_CODE (VALUE_TYPE (arg2)) != TYPE_CODE_INT)
723 error ("Non-integral right operand for \"@\" operator.");
724 if (noside == EVAL_AVOID_SIDE_EFFECTS)
725 return allocate_repeat_value (VALUE_TYPE (arg1),
726 longest_to_int (value_as_long (arg2)));
728 return value_repeat (arg1, longest_to_int (value_as_long (arg2)));
731 evaluate_subexp (NULL_TYPE, exp, pos, noside);
732 return evaluate_subexp (NULL_TYPE, exp, pos, noside);
735 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
736 if (noside == EVAL_SKIP)
738 if (unop_user_defined_p (op, arg1))
739 return value_x_unop (arg1, op);
741 return value_neg (arg1);
744 /* C++: check for and handle destructor names. */
745 op = exp->elts[*pos].opcode;
747 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
748 if (noside == EVAL_SKIP)
750 if (unop_user_defined_p (UNOP_LOGNOT, arg1))
751 return value_x_unop (arg1, UNOP_LOGNOT);
753 return value_lognot (arg1);
756 arg1 = evaluate_subexp (NULL_TYPE, exp, pos, noside);
757 if (noside == EVAL_SKIP)
759 if (unop_user_defined_p (op, arg1))
760 return value_x_unop (arg1, op);
762 return value_from_longest (builtin_type_int,
763 (LONGEST) value_zerop (arg1));
766 if (expect_type && TYPE_CODE (expect_type) == TYPE_CODE_PTR)
767 expect_type = TYPE_TARGET_TYPE (expect_type);
768 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
769 if (noside == EVAL_SKIP)
771 if (noside == EVAL_AVOID_SIDE_EFFECTS)
773 if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_PTR
774 || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_REF
775 /* In C you can dereference an array to get the 1st elt. */
776 || TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_ARRAY
778 return value_zero (TYPE_TARGET_TYPE (VALUE_TYPE (arg1)),
780 else if (TYPE_CODE (VALUE_TYPE (arg1)) == TYPE_CODE_INT)
781 /* GDB allows dereferencing an int. */
782 return value_zero (builtin_type_int, lval_memory);
784 error ("Attempt to take contents of a non-pointer value.");
786 return value_ind (arg1);
789 /* C++: check for and handle pointer to members. */
791 op = exp->elts[*pos].opcode;
793 if (noside == EVAL_SKIP)
797 char *name = &exp->elts[pc+3].string;
798 int temm = strlen (name);
799 (*pos) += 2 + (temm + sizeof (union exp_element)) / sizeof (union exp_element);
802 evaluate_subexp (expect_type, exp, pos, EVAL_SKIP);
806 return evaluate_subexp_for_address (exp, pos, noside);
809 if (noside == EVAL_SKIP)
811 evaluate_subexp (NULL_TYPE, exp, pos, EVAL_SKIP);
814 return evaluate_subexp_for_sizeof (exp, pos);
818 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
819 if (noside == EVAL_SKIP)
821 return value_cast (exp->elts[pc + 1].type, arg1);
825 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
826 if (noside == EVAL_SKIP)
828 if (noside == EVAL_AVOID_SIDE_EFFECTS)
829 return value_zero (exp->elts[pc + 1].type, lval_memory);
831 return value_at_lazy (exp->elts[pc + 1].type,
832 value_as_pointer (arg1));
834 case UNOP_PREINCREMENT:
835 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
836 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
838 else if (unop_user_defined_p (op, arg1))
840 return value_x_unop (arg1, op);
844 arg2 = value_add (arg1, value_from_longest (builtin_type_char,
846 return value_assign (arg1, arg2);
849 case UNOP_PREDECREMENT:
850 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
851 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
853 else if (unop_user_defined_p (op, arg1))
855 return value_x_unop (arg1, op);
859 arg2 = value_sub (arg1, value_from_longest (builtin_type_char,
861 return value_assign (arg1, arg2);
864 case UNOP_POSTINCREMENT:
865 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
866 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
868 else if (unop_user_defined_p (op, arg1))
870 return value_x_unop (arg1, op);
874 arg2 = value_add (arg1, value_from_longest (builtin_type_char,
876 value_assign (arg1, arg2);
880 case UNOP_POSTDECREMENT:
881 arg1 = evaluate_subexp (expect_type, exp, pos, noside);
882 if (noside == EVAL_SKIP || noside == EVAL_AVOID_SIDE_EFFECTS)
884 else if (unop_user_defined_p (op, arg1))
886 return value_x_unop (arg1, op);
890 arg2 = value_sub (arg1, value_from_longest (builtin_type_char,
892 value_assign (arg1, arg2);
898 return value_of_this (1);
901 error ("internal error: I do not know how to evaluate what you gave me");
905 return value_from_longest (builtin_type_long, (LONGEST) 1);
908 /* Evaluate a subexpression of EXP, at index *POS,
909 and return the address of that subexpression.
910 Advance *POS over the subexpression.
911 If the subexpression isn't an lvalue, get an error.
912 NOSIDE may be EVAL_AVOID_SIDE_EFFECTS;
913 then only the type of the result need be correct. */
916 evaluate_subexp_for_address (exp, pos, noside)
917 register struct expression *exp;
926 op = exp->elts[pc].opcode;
932 return evaluate_subexp (NULL_TYPE, exp, pos, noside);
936 return value_cast (lookup_pointer_type (exp->elts[pc + 1].type),
937 evaluate_subexp (NULL_TYPE, exp, pos, noside));
940 var = exp->elts[pc + 1].symbol;
942 /* C++: The "address" of a reference should yield the address
943 * of the object pointed to. Let value_addr() deal with it. */
944 if (TYPE_CODE (SYMBOL_TYPE (var)) == TYPE_CODE_REF)
948 if (noside == EVAL_AVOID_SIDE_EFFECTS)
951 lookup_pointer_type (SYMBOL_TYPE (var));
952 enum address_class sym_class = SYMBOL_CLASS (var);
954 if (sym_class == LOC_CONST
955 || sym_class == LOC_CONST_BYTES
956 || sym_class == LOC_REGISTER
957 || sym_class == LOC_REGPARM)
958 error ("Attempt to take address of register or constant.");
961 value_zero (type, not_lval);
964 return locate_var_value (var, (FRAME) 0);
968 if (noside == EVAL_AVOID_SIDE_EFFECTS)
970 value x = evaluate_subexp (NULL_TYPE, exp, pos, noside);
971 if (VALUE_LVAL (x) == lval_memory)
972 return value_zero (lookup_pointer_type (VALUE_TYPE (x)),
975 error ("Attempt to take address of non-lval");
977 return value_addr (evaluate_subexp (NULL_TYPE, exp, pos, noside));
981 /* Evaluate like `evaluate_subexp' except coercing arrays to pointers.
982 When used in contexts where arrays will be coerced anyway,
983 this is equivalent to `evaluate_subexp'
984 but much faster because it avoids actually fetching array contents. */
987 evaluate_subexp_with_coercion (exp, pos, noside)
988 register struct expression *exp;
992 register enum exp_opcode op;
998 op = exp->elts[pc].opcode;
1003 var = exp->elts[pc + 1].symbol;
1004 if (TYPE_CODE (SYMBOL_TYPE (var)) == TYPE_CODE_ARRAY)
1007 val = locate_var_value (var, (FRAME) 0);
1008 return value_cast (lookup_pointer_type (TYPE_TARGET_TYPE (SYMBOL_TYPE (var))),
1012 return evaluate_subexp (NULL_TYPE, exp, pos, noside);
1016 /* Evaluate a subexpression of EXP, at index *POS,
1017 and return a value for the size of that subexpression.
1018 Advance *POS over the subexpression. */
1021 evaluate_subexp_for_sizeof (exp, pos)
1022 register struct expression *exp;
1030 op = exp->elts[pc].opcode;
1034 /* This case is handled specially
1035 so that we avoid creating a value for the result type.
1036 If the result type is very big, it's desirable not to
1037 create a value unnecessarily. */
1040 val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
1041 return value_from_longest (builtin_type_int, (LONGEST)
1042 TYPE_LENGTH (TYPE_TARGET_TYPE (VALUE_TYPE (val))));
1046 return value_from_longest (builtin_type_int,
1047 (LONGEST) TYPE_LENGTH (exp->elts[pc + 1].type));
1051 return value_from_longest (builtin_type_int,
1052 (LONGEST) TYPE_LENGTH (SYMBOL_TYPE (exp->elts[pc + 1].symbol)));
1055 val = evaluate_subexp (NULL_TYPE, exp, pos, EVAL_AVOID_SIDE_EFFECTS);
1056 return value_from_longest (builtin_type_int,
1057 (LONGEST) TYPE_LENGTH (VALUE_TYPE (val)));
1061 /* Parse a type expression in the string [P..P+LENGTH). */
1064 parse_and_eval_type (p, length)
1068 char *tmp = (char *)alloca (length + 4);
1069 struct expression *expr;
1071 (void) memcpy (tmp+1, p, length);
1072 tmp[length+1] = ')';
1073 tmp[length+2] = '0';
1074 tmp[length+3] = '\0';
1075 expr = parse_expression (tmp);
1076 if (expr->elts[0].opcode != UNOP_CAST)
1077 error ("Internal error in eval_type.");
1078 return expr->elts[1].type;