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
;