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git/usage.c
Brandon Casey cd163d4b4e usage.c: detect recursion in die routines and bail out immediately
It is theoretically possible for a die handler to get into a state of
infinite recursion.  For example, if a die handler called another function
which itself called die().  Let's at least detect this situation, inform the
user, and call exit.

Signed-off-by: Brandon Casey <bcasey@nvidia.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-11-15 18:04:54 -08:00

150 lines
3.1 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "git-compat-util.h"
#include "cache.h"
static int dying;
void vreportf(const char *prefix, const char *err, va_list params)
{
char msg[4096];
vsnprintf(msg, sizeof(msg), err, params);
fprintf(stderr, "%s%s\n", prefix, msg);
}
void vwritef(int fd, const char *prefix, const char *err, va_list params)
{
char msg[4096];
int len = vsnprintf(msg, sizeof(msg), err, params);
if (len > sizeof(msg))
len = sizeof(msg);
write_in_full(fd, prefix, strlen(prefix));
write_in_full(fd, msg, len);
write_in_full(fd, "\n", 1);
}
static NORETURN void usage_builtin(const char *err, va_list params)
{
vreportf("usage: ", err, params);
exit(129);
}
static NORETURN void die_builtin(const char *err, va_list params)
{
vreportf("fatal: ", err, params);
exit(128);
}
static void error_builtin(const char *err, va_list params)
{
vreportf("error: ", err, params);
}
static void warn_builtin(const char *warn, va_list params)
{
vreportf("warning: ", warn, params);
}
/* If we are in a dlopen()ed .so write to a global variable would segfault
* (ugh), so keep things static. */
static NORETURN_PTR void (*usage_routine)(const char *err, va_list params) = usage_builtin;
static NORETURN_PTR void (*die_routine)(const char *err, va_list params) = die_builtin;
static void (*error_routine)(const char *err, va_list params) = error_builtin;
static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
void set_die_routine(NORETURN_PTR void (*routine)(const char *err, va_list params))
{
die_routine = routine;
}
void set_error_routine(void (*routine)(const char *err, va_list params))
{
error_routine = routine;
}
void NORETURN usagef(const char *err, ...)
{
va_list params;
va_start(params, err);
usage_routine(err, params);
va_end(params);
}
void NORETURN usage(const char *err)
{
usagef("%s", err);
}
void NORETURN die(const char *err, ...)
{
va_list params;
if (dying) {
fputs("fatal: recursion detected in die handler\n", stderr);
exit(128);
}
dying = 1;
va_start(params, err);
die_routine(err, params);
va_end(params);
}
void NORETURN die_errno(const char *fmt, ...)
{
va_list params;
char fmt_with_err[1024];
char str_error[256], *err;
int i, j;
if (dying) {
fputs("fatal: recursion detected in die_errno handler\n",
stderr);
exit(128);
}
dying = 1;
err = strerror(errno);
for (i = j = 0; err[i] && j < sizeof(str_error) - 1; ) {
if ((str_error[j++] = err[i++]) != '%')
continue;
if (j < sizeof(str_error) - 1) {
str_error[j++] = '%';
} else {
/* No room to double the '%', so we overwrite it with
* '\0' below */
j--;
break;
}
}
str_error[j] = 0;
snprintf(fmt_with_err, sizeof(fmt_with_err), "%s: %s", fmt, str_error);
va_start(params, fmt);
die_routine(fmt_with_err, params);
va_end(params);
}
int error(const char *err, ...)
{
va_list params;
va_start(params, err);
error_routine(err, params);
va_end(params);
return -1;
}
void warning(const char *warn, ...)
{
va_list params;
va_start(params, warn);
warn_routine(warn, params);
va_end(params);
}