git/trace.c
Brandon Casey e83c267f71 trace.c: ensure NULL is not passed to printf
GNU printf, and many others, will print the string "(null)" if a NULL
pointer is passed as the argument to a "%s" format specifier.  Some
implementations (like on Solaris) do not detect a NULL pointer and will
produce a segfault in this case.

So, fix this by ensuring that pointer variables do not contain the value
NULL.  Assign the string "(null)" to the variables are NULL.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-01-06 12:21:49 -08:00

179 lines
4.7 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
* Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
* Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
* Copyright (C) 2006 Mike McCormack
* Copyright (C) 2006 Christian Couder
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "cache.h"
#include "quote.h"
/* Get a trace file descriptor from GIT_TRACE env variable. */
static int get_trace_fd(int *need_close)
{
char *trace = getenv("GIT_TRACE");
if (!trace || !strcmp(trace, "") ||
!strcmp(trace, "0") || !strcasecmp(trace, "false"))
return 0;
if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
return STDERR_FILENO;
if (strlen(trace) == 1 && isdigit(*trace))
return atoi(trace);
if (is_absolute_path(trace)) {
int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
if (fd == -1) {
fprintf(stderr,
"Could not open '%s' for tracing: %s\n"
"Defaulting to tracing on stderr...\n",
trace, strerror(errno));
return STDERR_FILENO;
}
*need_close = 1;
return fd;
}
fprintf(stderr, "What does '%s' for GIT_TRACE mean?\n", trace);
fprintf(stderr, "If you want to trace into a file, "
"then please set GIT_TRACE to an absolute pathname "
"(starting with /).\n");
fprintf(stderr, "Defaulting to tracing on stderr...\n");
return STDERR_FILENO;
}
static const char err_msg[] = "Could not trace into fd given by "
"GIT_TRACE environment variable";
void trace_printf(const char *fmt, ...)
{
struct strbuf buf;
va_list ap;
int fd, len, need_close = 0;
fd = get_trace_fd(&need_close);
if (!fd)
return;
set_try_to_free_routine(NULL); /* is never reset */
strbuf_init(&buf, 64);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf)) {
strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf))
die("broken vsnprintf");
}
strbuf_setlen(&buf, len);
write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
strbuf_release(&buf);
if (need_close)
close(fd);
}
void trace_argv_printf(const char **argv, const char *fmt, ...)
{
struct strbuf buf;
va_list ap;
int fd, len, need_close = 0;
fd = get_trace_fd(&need_close);
if (!fd)
return;
set_try_to_free_routine(NULL); /* is never reset */
strbuf_init(&buf, 64);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf)) {
strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
va_start(ap, fmt);
len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&buf))
die("broken vsnprintf");
}
strbuf_setlen(&buf, len);
sq_quote_argv(&buf, argv, 0);
strbuf_addch(&buf, '\n');
write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
strbuf_release(&buf);
if (need_close)
close(fd);
}
static const char *quote_crnl(const char *path)
{
static char new_path[PATH_MAX];
const char *p2 = path;
char *p1 = new_path;
if (!path)
return NULL;
while (*p2) {
switch (*p2) {
case '\\': *p1++ = '\\'; *p1++ = '\\'; break;
case '\n': *p1++ = '\\'; *p1++ = 'n'; break;
case '\r': *p1++ = '\\'; *p1++ = 'r'; break;
default:
*p1++ = *p2;
}
p2++;
}
*p1 = '\0';
return new_path;
}
/* FIXME: move prefix to startup_info struct and get rid of this arg */
void trace_repo_setup(const char *prefix)
{
const char *git_work_tree;
char cwd[PATH_MAX];
char *trace = getenv("GIT_TRACE");
if (!trace || !strcmp(trace, "") ||
!strcmp(trace, "0") || !strcasecmp(trace, "false"))
return;
if (!getcwd(cwd, PATH_MAX))
die("Unable to get current working directory");
if (!(git_work_tree = get_git_work_tree()))
git_work_tree = "(null)";
if (!prefix)
prefix = "(null)";
trace_printf("setup: git_dir: %s\n", quote_crnl(get_git_dir()));
trace_printf("setup: worktree: %s\n", quote_crnl(git_work_tree));
trace_printf("setup: cwd: %s\n", quote_crnl(cwd));
trace_printf("setup: prefix: %s\n", quote_crnl(prefix));
}