Revision d64ea0f83bd7e676778f833c57f969a94518a28d authored by Jeff King on 13 January 2015, 01:57:37 UTC, committed by Junio C Hamano on 13 January 2015, 18:03:30 UTC
It's a common idiom to duplicate a string if it is non-NULL, or pass a literal NULL through. This is already a one-liner in C, but you do have to repeat the name of the string twice. So if there's a function call, you must write: const char *x = some_fun(...); return x ? xstrdup(x) : NULL; instead of (with this patch) just: return xstrdup_or_null(some_fun(...)); Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 1da1e07
sigchain.c
#include "sigchain.h"
#include "cache.h"
#define SIGCHAIN_MAX_SIGNALS 32
struct sigchain_signal {
sigchain_fun *old;
int n;
int alloc;
};
static struct sigchain_signal signals[SIGCHAIN_MAX_SIGNALS];
static void check_signum(int sig)
{
if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS)
die("BUG: signal out of range: %d", sig);
}
int sigchain_push(int sig, sigchain_fun f)
{
struct sigchain_signal *s = signals + sig;
check_signum(sig);
ALLOC_GROW(s->old, s->n + 1, s->alloc);
s->old[s->n] = signal(sig, f);
if (s->old[s->n] == SIG_ERR)
return -1;
s->n++;
return 0;
}
int sigchain_pop(int sig)
{
struct sigchain_signal *s = signals + sig;
check_signum(sig);
if (s->n < 1)
return 0;
if (signal(sig, s->old[s->n - 1]) == SIG_ERR)
return -1;
s->n--;
return 0;
}
void sigchain_push_common(sigchain_fun f)
{
sigchain_push(SIGINT, f);
sigchain_push(SIGHUP, f);
sigchain_push(SIGTERM, f);
sigchain_push(SIGQUIT, f);
sigchain_push(SIGPIPE, f);
}
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