Re: [3/8] kill gen_init_cpio.c printk() of size_t warning

[linux-os]

On Mon, 3 Jan 2005, H. Peter Anvin wrote:

> William Lee Irwin III wrote:
> > On Mon, Jan 03, 2005 at 09:09:48PM +0000, H. Peter Anvin wrote:
> >
> > > Dear Wrongbot,
> > > Bullshit.  Signed is promoted to unsigned.
> >
> > I'm not sure who you're responding to here, but gcc emitted an actual
> > warning and I was only attempting to carry out the minimal effort
> > necessary to silence it. I'm not really interested in creating or
> > being involved with controversy, just silencing the core build in the
> > least invasive and so on way possible, leaving deeper drivers/ issues
> > to the resolution of the true underlying problems.
> >
> > I don't have anything to do with the code excerpt above; I merely
> > followed the style of the other unsigned integer coercions in the file.
>
> I was not responding to you, your stuff is perfectly sane.
>
> The claim from the Wrongbot was that "foo + 1" is bad when foo is a size_t. 
> This is utter bullshit, since that's EXACTLY equivalent to:
>
> 	foo + (size_t)1
>
> ... because of promotion rules.
>
> 	-hpa
> -

I made no such claim. I claimed that the posted fix was wrong:

> Index: mm1-2.6.10/usr/gen_init_cpio.c
> ===================================================================
> --- mm1-2.6.10.orig/usr/gen_init_cpio.c	2005-01-03 06:45:53.000000000 -0800
> +++ mm1-2.6.10/usr/gen_init_cpio.c	2005-01-03 09:42:18.000000000 -0800
> @@ -112,7 +112,7 @@
> 		(long) gid,		/* gid */
> 		1,			/* nlink */
> 		(long) mtime,		/* mtime */
> -		strlen(target) + 1,	/* filesize */
> +		(unsigned)strlen(target) + 1,/* filesize */
> 		3,			/* major */
> 		1,			/* minor */
> 		0,			/* rmajor */
> -


This is wrong because strlen() already returns a size_t (unsigned).
This "fix" only served to quiet the compiler which was warning
about the conversion. It is a "conversion", not a "promotion".
The simple fix to quiet this conversion warning is to use 1U
as previously shown.

Cheers,
Dick Johnson
Penguin : Linux version 2.6.9 on an i686 machine (5537.79 BogoMips).
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