[PATCH] -var-update [was Re: Variable objects: references formatting]

Nick Roberts
2006-05-08T12:41:34Z

> > However, do you see the problem with references that I mentioned earlier
> > (that they don't seem to disappear from the changelist with -var-update)?
> > This seems to be the case for any variable object made from a reference.
>
> Yes, I see that for variable object created from reference, -var-update *
> always mentions that. Looking at this under debugger, it seems that the call
> to my_value_equal in varobj_update compares the value of *reference* to the
> value of new *referenced-to* object. This happens in my_value_equal
> (varobj.c):
>
> static int
> my_value_equal (struct value *val1, struct value *volatile val2, int
> *error2)
> ...

> ...Alas, quick attempt to do that results in segfault, and I'm out of
> time for today. Feel free to beat me to it ;-)

I think this patch works. My reasoning is one of symmetry: whatever is done to
val2 should also be done to val1, and that you probably don't want to change
the contents of val1 (hence val3). I don't know exactly what coerce_array
does, apart from convert the type from TYPE_CODE_REF to TYPE_CODE_INT or
TYPE_CODE_FLOAT or whatever, so the comment might not be quite right.

AFAICS it introduces no new fails into the testsuite. Then again there
are no tests for references, so I guess a new one would be appropriate

--
Nick http://www.inet.net.nz/~nickrob

2006-05-09 Nick Roberts <nickrob@snap.net.nz>

* varobj.c (my_value_equal): Make it work for references.

*** varobj.c 04 May 2006 22:11:38 +1200 1.60
--- varobj.c 09 May 2006 00:08:55 +1200
***************
*** 1460,1465 ****
--- 1460,1466 ----
my_value_equal (struct value *val1, struct value *volatile val2, int *error2)
{
volatile struct gdb_exception except;
+ struct value *val3;

/* As a special case, if both are null, we say they're equal. */
if (val1 == NULL && val2 == NULL)
***************
*** 1470,1475 ****
--- 1471,1479 ----
/* The contents of VAL1 are supposed to be known. */
gdb_assert (!value_lazy (val1));

+ /* Make sure we get the contents of VAL1. */
+ val3 = coerce_array (val1);
+
/* Make sure we also know the contents of VAL2. */
val2 = coerce_array (val2);
TRY_CATCH (except, RETURN_MASK_ERROR)
***************
*** 1484,1490 ****
}
gdb_assert (!value_lazy (val2));

! return value_contents_equal (val1, val2);
}

/* FIXME: The following should be generic for any pointer */
--- 1488,1494 ----
}
gdb_assert (!value_lazy (val2));

! return value_contents_equal (val3, val2);
}

/* FIXME: The following should be generic for any pointer */