Re: [U-Boot] [PATCH resend] kconfig: Fix compiler warning in menu.c
From: Jeroen Hofstee
Date: Mon Oct 13 2014 - 02:48:48 EST
Hello Simon,
On 13-10-14 07:14, Simon Glass wrote:
Hi Jeroen,
On 12 October 2014 10:13, Jeroen Hofstee <jeroen@xxxxxxxxxxxxx> wrote:
Hello Hans,
On 12-10-14 12:25, Hans de Goede wrote:
Hi,
This one seems to have fallen through the cracks.
Regards,
Hans
(for U-boot)
nope, you replace an innocent warning (_might_ be) with
bad code, without any comment it is just because gcc failed
to recognize it is fine. Nor did you respond to the suggestion
if it helps gcc to recognize that if the two booleans are merged
into a single one. [or even split it in an if () if ()]. With this patch
you prevent any serious warning in case the variable is actually
used but not initialized, which is even worse if you ask me.
That is a pretty acerbic tone to take on the U-Boot list at least. Are you
two drinking buddies or something?
no, it is because we have discussed this patch before and resending
it won't address the issue raised. But you are right, it is likely done with
less evil intends then I took it for, so let me explain my concern again
in a politer way. The problem is that gcc 4.9 starts warning in the
following case:
int *ptr;
if (a)
ptr = something;
if (a && b)
ptr->bla = value;
else
do_something_else();
it will warn that ptr _might_ be used uninitialized (but it always is).
This is fixed in this patch by assigning NULL to ptr, and while that makes
the warning go away it actually prevents the valid warning, ptr _is_ used
uninitialized if you start using it in the else case. Hence my request if we
can't find a better solution for this.
Does anyone know a better solution for this or should we consider
disabling the might be unused warning?
Regards,
Jeroen
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/