From 4d0dbb8b634ab0ec833348502aff284598858696 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Fri, 16 Oct 2009 00:42:22 +0200 Subject: [PATCH] include: add c.h with fundamental C definitions Add: * ARRAY_SIZE with array type check * PATH_MAX, TRUE and FALSE macros * dummy __attribute__ for non-gcc compilers Signed-off-by: Karel Zak --- include/Makefile.am | 1 + include/c.h | 49 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 50 insertions(+) create mode 100644 include/c.h diff --git a/include/Makefile.am b/include/Makefile.am index 9f581fda..525e3d2e 100644 --- a/include/Makefile.am +++ b/include/Makefile.am @@ -1,6 +1,7 @@ include $(top_srcdir)/config/include-Makefile.am dist_noinst_HEADERS = \ + c.h \ bitops.h \ blkdev.h \ canonicalize.h \ diff --git a/include/c.h b/include/c.h new file mode 100644 index 00000000..413366b2 --- /dev/null +++ b/include/c.h @@ -0,0 +1,49 @@ +/* + * Fundamental C definitions. + */ + +#ifndef UTIL_LINUX_C_H +#define UTIL_LINUX_C_H + +#include + +/* + * Compiler specific stuff + */ +#ifdef __GNUC__ + +/* &a[0] degrades to a pointer: a different type from an array */ +# define __must_be_array(a) \ + BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0]))) + +#else /* !__GNUC__ */ +# define __must_be_array(a) 0 +# define __attribute__(_arg_) +#endif /* !__GNUC__ */ + + +/* Force a compilation error if condition is true, but also produce a + * result (of value 0 and type size_t), so the expression can be used + * e.g. in a structure initializer (or where-ever else comma expressions + * aren't permitted). + */ +#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); })) +#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); })) + +#ifndef ARRAY_SIZE +# define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr)) +#endif + +#ifndef PATH_MAX +# define PATH_MAX 4096 +#endif + +#ifndef TRUE +# define TRUE 1 +#endif + +#ifndef FALSE +# define FALSE 0 +#endif + +#endif /* UTIL_LINUX_C_H */ -- 2.39.5