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
;