diff options
| author | Andrew Burgess <andrew.burgess@embecosm.com> | 2016-05-24 16:17:52 +0100 |
|---|---|---|
| committer | Andrew Burgess <andrew.burgess@embecosm.com> | 2016-05-27 13:06:25 +0100 |
| commit | ac775bf4d35b7a2d5715e0ccf3d648d4670213fd (patch) | |
| tree | 2a194c3e19f7e27d8fd9fb9ae6a3c130f9eb0dca /gdb/eval.c | |
| parent | 9d07ebe108f4e11508e350eaf2ba10d7480636fa (diff) | |
gdb: Forward VALUE_LVAL when avoiding side effects for STRUCTOP_PTR
Assume that we have a C program like this:
struct foo_type
{
int var;
} foo;
struct foo_type *foo_ptr = &foo;
int
main ()
{
return foo_ptr->var;
}
Then GDB should be able to evaluate the following, however, it currently
does not:
(gdb) start
...
(gdb) whatis &(foo_ptr->var)
Attempt to take address of value not located in memory.
The problem is that in EVAL_AVOID_SIDE_EFFECTS mode,
eval.c:evaluate_subexp_standard always returns a not_lval value as the
result for a STRUCTOP_PTR operation. As a consequence, the rest of
the code believes that one cannot take the address of the returned
value.
This patch fixes STRUCTOP_PTR handling so that the VALUE_LVAL
attribute for the returned value is properly initialized. After this
change, the above session becomes:
(gdb) start
...
(gdb) whatis &(foo_ptr->var)
type = int *
This commit is largely the same as commit 2520f728b710 (Forward
VALUE_LVAL when avoiding side effects for STRUCTOP_STRUCT) but applied
to STRUCTOP_PTR rather than STRUCTOP_STRUCT. Both of these commits are
building on top of commit ac1ca910d74d (Fixes for PR exp/15364).
gdb/ChangeLog:
* eval.c (evaluate_subexp_standard): If EVAL_AVOID_SIDE_EFFECTS
mode, forward the VALUE_LVAL attribute to the returned value in
the STRUCTOP_PTR case.
gdb/testsuite/ChangeLog:
* gdb.base/whatis.c: Extend the test case.
* gdb.base/whatis.exp: Add additional tests.
Diffstat (limited to 'gdb/eval.c')
| -rw-r--r-- | gdb/eval.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/gdb/eval.c b/gdb/eval.c index 3f8ca662a2..de1c6632e0 100644 --- a/gdb/eval.c +++ b/gdb/eval.c @@ -1917,7 +1917,7 @@ evaluate_subexp_standard (struct type *expect_type, arg3 = value_struct_elt (&arg1, NULL, &exp->elts[pc + 2].string, NULL, "structure pointer"); if (noside == EVAL_AVOID_SIDE_EFFECTS) - arg3 = value_zero (value_type (arg3), not_lval); + arg3 = value_zero (value_type (arg3), VALUE_LVAL (arg3)); return arg3; case STRUCTOP_MEMBER: |