From: Wang Nan <pi3orama@xxxxxxxxx> According to C standard, numerical limitations macros such as ULONG_MAX should be defined in <limits.h>, and must be defined as "constant expressions suitable for use in #if preprocessing directives." (see "Numerical limits" section in the standard). Original definition in common.h breaks this rule: #define LONG_MAX ((long)(~0UL>>1)) which causes macros like following failure: #if LONG_MAX == 2147483647 # define LONG_BIT 32 #else # define LONG_BIT 64 #endif Unfortunately, the above code piece is taken from real glibc header (/usr/include/bits/xopen_lim.h), which is happen to be included by <limits.h> if _GNU_SOURCE is defined. This patch include <limits.h> in common.h to use C standard numerical macros. For system without such macros defined by C, this patch also defines L(L)ONG_MAX in a standard compatible way. By checking wich gcc -dM -E - <<<'' we know that __LONG_MAX__ and __LLONG_MAX__ macros should be defined by gcc by default. Definition of ULONG_MAX and ULLONG_MAX are taken from gcc standard include file (include-fixed/limits.h). In addition, macro ULONGLONG_MAX is nonstandard, the standard way for defining max ulonglong is ULLONG_MAX. Signed-off-by: Wang Nan <wangnan0 at huawei.com> Cc: Atsushi Kumagai <kumagai-atsushi at mxc.nes.nec.co.jp> Cc: Petr Tesarik <ptesarik at suse.cz> Cc: kexec at lists.infradead.org Cc: Geng Hui <hui.geng at huawei.com> Cc: Liu Hua <sdu.liu at huawei.com> --- common.h | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/common.h b/common.h index 6ad3ca7..124f107 100644 --- a/common.h +++ b/common.h @@ -16,17 +16,29 @@ #ifndef _COMMON_H #define _COMMON_H +#include <limits.h> + #define TRUE (1) #define FALSE (0) #define ERROR (-1) #ifndef LONG_MAX -#define LONG_MAX ((long)(~0UL>>1)) +# warning LONG_MAX should have been defined in <limits.h> +# define LONG_MAX __LONG_MAX__ #endif #ifndef ULONG_MAX -#define ULONG_MAX (~0UL) +# warning ULONG_MAX should have been defined in <limits.h> +# define ULONG_MAX (LONG_MAX * 2UL + 1UL) +#endif +#ifndef LLONG_MAX +# warning LLONG_MAX should have been defined in <limits.h> +# define LLONG_MAX __LONG_LONG_MAX__ +#endif +#ifndef ULLONG_MAX +# warning ULLONG_MAX should have been defined in <limits.h> +# define ULLONG_MAX (LLONG_MAX * 2ULL + 1ULL) #endif -#define ULONGLONG_MAX (~0ULL) +#define ULONGLONG_MAX ULLONG_MAX #define MAX(a,b) ((a) > (b) ? (a) : (b)) #define MIN(a,b) ((a) < (b) ? (a) : (b)) -- 1.8.4
