Re: size_t/ssize_t warnings (was: Re: Build regressions/improvements inv3.5-rc5)

From: Hans-Peter Nilsson
Date: Thu Jul 05 2012 - 21:18:41 EST


> From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Date: Wed, 4 Jul 2012 22:17:28 +0200

> On Wed, Jul 4, 2012 at 3:34 PM, Jan Kara <jack@xxxxxxx> wrote:
> >> + fs/quota/quota_tree.c: warning: format '%zd' expects argument of type 'signed size_t', but argument 4 has type 'ssize_t' [-Wformat]: => 372:4
> >> + fs/quota/quota_v2.c: warning: format '%zd' expects argument of type 'signed size_t', but argument 5 has type 'ssize_t' [-Wformat]: => 66:92
> > These really look like false positives (there are quite a few of this
> > kind). Can we possibly silence them?
>
> These 2 warnings happen on cris only, because size_t is unsigned int and
> ssize_t is (signed) long.

Um, no, ssize_t isn't long. Do you mean __kernel_ssize_t?
(Or are you looking at cris-axis-elf? ...no, that can't be it,
as you see __SIZE_TYPE__ being unsigned int.)

> They go away if I make ssize_t int.

But ssize_t already is int...

N.B. size_t is different between cris-axis-elf and
cris-axis-linux-gnu. The former uses the default definition in
gcc/defaults.h (long unsigned int) and the latter sets it
specifically to "unsigned int", in gcc/config/cris/linux.h (or
before 2010-12-09, from config/svr4.h). The ssize_t definition
comes from glibc, where it is "int".

> __kernel_size_t __kernel_ssize_t
> --------------- ----------------

> cris: __SIZE_TYPE__ (unsigned int) long

A bit odd; __kernel_ssize_t should probably change to int, to
match ssize_t.

> Cris-people: __SIZE_TYPE__ turned out to be hardcoded in my compiler (gcc
> 4.6.3 from Tony's collection) to unsigned int. Is that correct?

Correct, for cris-axis-linux-gnu.

> And why do some 32-bit architectures use unsigned long/long?

I'd guess from the gcc default.

brgds, H-P
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