Re: Build regressions/improvements in v3.19-rc3

From: Geert Uytterhoeven
Date: Tue Jan 06 2015 - 14:37:18 EST


Hi Peter,

On Tue, Jan 6, 2015 at 8:12 PM, Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> wrote:
>> + /home/kisskb/slave/src/drivers/tty/serial/8250/8250_core.c: warning: 'flags' may be used uninitialized in this function: => 3186:16
>
> Is there some way of finding out what gcc + config produced this warning?

I have it in my summary, but I first have to learn kup before I can publish it.

It's from or32/or1ksim_defconfig, with or32-linux-gcc 4.5.1-or32-1.0rc1.
That's the only remaining 4.5 compiler used by kisskb, I think.

Note that I also see it with m68k-linux-gnu-gcc version 4.1.2 20061115
(prerelease) (Ubuntu 4.1.1-21), which is still my main kernel compiler for m68k.

> I know what commit produced this build regression but I'm not seeing a problem

(old) gcc is not smart enough to notice that flags is used only if locked = 1.
(new) gcc is probably also not smart enough, but someone disabled those
warnings because there were too many false positives...

Anyway, I always investigate new warnings that show up in my m68k builds
(incl. allyesconfig and allmodconfig, plain and limited to Sun-3). So I already
knew this is a false positive ;-)

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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