[PATCH] make memcmp arguments const

[Simon Horman]

On Mon, Nov 03, 2008 at 03:34:36PM +0100, Stefan Assmann wrote:
> In purgatory/string.c the definition of memcmp is
> 	int memcmp(void *src1, void *src2, size_t len)
> man memcmp reveals
> 	int memcmp(const void *s1, const void *s2, size_t n)
> 
> Signed-off-by: Stefan Assmann <sassmann at suse.de>
> 
> ---
>  purgatory/string.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> --- a/purgatory/string.c
> +++ b/purgatory/string.c
> @@ -36,9 +36,9 @@ void* memcpy(void *dest, const void *src
>  }
> 
> 
> -int memcmp(void *src1, void *src2, size_t len)
> +int memcmp(const void *src1, const void *src2, size_t len)
>  {
> -	unsigned char *s1, *s2;
> +	const unsigned char *s1, *s2;
>  	size_t i;
>  	s1 = src1;
>  	s2 = src2;

Hi Stefan,

this change seems reasonable to me, but I think that
the declaration also needs to be updated. If the change
below is fine by you, could you please add it to your patch
and repost ?

# gcc --version
gcc (Debian 4.3.2-1) 4.3.2
Copyright (C) 2008 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

# make
...
gcc -Wall -O2 -fomit-frame-pointer -pipe -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss  -Os -fno-builtin -ffreestanding  -I./purgatory/include -I./purgatory/arch/i386/include -I./util_lib/include -I/usr/lib/gcc/i486-linux-gnu/4.3.2/include  -c -MD -o purgatory/string.o purgatory/string.c
purgatory/string.c:39: error: conflicting types for $B!F(Bmemcmp$B!G(B
./purgatory/include/string.h:9: error: previous declaration of $B!F(Bmemcmp$B!G(B was
here
make: *** [purgatory/string.o] Error 1

Index: kexec-tools/purgatory/include/string.h
===================================================================
--- kexec-tools.orig/purgatory/include/string.h	2008-11-04 09:07:48.000000000 +1100
+++ kexec-tools/purgatory/include/string.h	2008-11-04 09:08:02.000000000 +1100
@@ -6,7 +6,7 @@
 size_t strnlen(const char *s, size_t max);
 void* memset(void* s, int c, size_t n);
 void* memcpy(void *dest, const void *src, size_t len);
-int memcmp(void *src1, void *src2, size_t len);
+int memcmp(const void *src1, const void *src2, size_t len);
 
 
 #endif /* STRING_H */

-- 
Simon Horman
  VA Linux Systems Japan K.K., Sydney, Australia Satellite Office
  H: www.vergenet.net/~horms/             W: www.valinux.co.jp/en