procps/proc/procps.h

#ifndef PROCPS_PROC_PROCPS_H
#define PROCPS_PROC_PROCPS_H

#ifdef  __cplusplus
#define EXTERN_C_BEGIN extern "C" {
#define EXTERN_C_END }
#else
#define EXTERN_C_BEGIN
#define EXTERN_C_END
#endif

#if !defined(restrict) && __STDC_VERSION__ < 199901
#if __GNUC__ > 2 || __GNUC_MINOR__ >= 91    // maybe 92 or 95 ?
#define restrict __restrict__
#else
#warning No restrict keyword?
#define restrict
#endif
#endif

// since gcc-2.5
#define NORETURN __attribute__((__noreturn__))

#if __GNUC__ > 2 || __GNUC_MINOR__ >= 96
// won't alias anything, and aligned enough for anything
#define MALLOC __attribute__ ((__malloc__))
// tell gcc what to expect:   if(unlikely(err)) die(err);
#define likely(x)       __builtin_expect(!!(x),1)
#define unlikely(x)     __builtin_expect(!!(x),0)
#define expected(x,y)   __builtin_expect((x),(y))
#else
#define MALLOC
#define likely(x)       (x)
#define unlikely(x)     (x)
#define expected(x,y)   (x)
#endif

#endif