git/exec_cmd.c
Jeff King 007ac54401 git_exec_path: do not return the result of getenv()
The result of getenv() is not guaranteed by POSIX to last
beyond another call to getenv(), or setenv(), etc.  We
should duplicate the string before returning to the caller
to avoid any surprises.

We already keep a cached pointer to avoid repeatedly leaking
the result of system_path(). We can use the same pointer
here to avoid allocating and leaking for each call.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-09 01:29:50 -08:00

156 lines
3.1 KiB
C

#include "cache.h"
#include "exec_cmd.h"
#include "quote.h"
#include "argv-array.h"
#define MAX_ARGS 32
static const char *argv_exec_path;
static const char *argv0_path;
char *system_path(const char *path)
{
#ifdef RUNTIME_PREFIX
static const char *prefix;
#else
static const char *prefix = PREFIX;
#endif
struct strbuf d = STRBUF_INIT;
if (is_absolute_path(path))
return xstrdup(path);
#ifdef RUNTIME_PREFIX
assert(argv0_path);
assert(is_absolute_path(argv0_path));
if (!prefix &&
!(prefix = strip_path_suffix(argv0_path, GIT_EXEC_PATH)) &&
!(prefix = strip_path_suffix(argv0_path, BINDIR)) &&
!(prefix = strip_path_suffix(argv0_path, "git"))) {
prefix = PREFIX;
trace_printf("RUNTIME_PREFIX requested, "
"but prefix computation failed. "
"Using static fallback '%s'.\n", prefix);
}
#endif
strbuf_addf(&d, "%s/%s", prefix, path);
return strbuf_detach(&d, NULL);
}
const char *git_extract_argv0_path(const char *argv0)
{
const char *slash;
if (!argv0 || !*argv0)
return NULL;
slash = find_last_dir_sep(argv0);
if (slash) {
argv0_path = xstrndup(argv0, slash - argv0);
return slash + 1;
}
return argv0;
}
void git_set_argv_exec_path(const char *exec_path)
{
argv_exec_path = exec_path;
/*
* Propagate this setting to external programs.
*/
setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
}
/* Returns the highest-priority, location to look for git programs. */
const char *git_exec_path(void)
{
static char *cached_exec_path;
if (argv_exec_path)
return argv_exec_path;
if (!cached_exec_path) {
const char *env = getenv(EXEC_PATH_ENVIRONMENT);
if (env && *env)
cached_exec_path = xstrdup(env);
else
cached_exec_path = system_path(GIT_EXEC_PATH);
}
return cached_exec_path;
}
static void add_path(struct strbuf *out, const char *path)
{
if (path && *path) {
strbuf_add_absolute_path(out, path);
strbuf_addch(out, PATH_SEP);
}
}
void setup_path(void)
{
const char *old_path = getenv("PATH");
struct strbuf new_path = STRBUF_INIT;
add_path(&new_path, git_exec_path());
if (old_path)
strbuf_addstr(&new_path, old_path);
else
strbuf_addstr(&new_path, _PATH_DEFPATH);
setenv("PATH", new_path.buf, 1);
strbuf_release(&new_path);
}
const char **prepare_git_cmd(struct argv_array *out, const char **argv)
{
argv_array_push(out, "git");
argv_array_pushv(out, argv);
return out->argv;
}
int execv_git_cmd(const char **argv) {
struct argv_array nargv = ARGV_ARRAY_INIT;
prepare_git_cmd(&nargv, argv);
trace_argv_printf(nargv.argv, "trace: exec:");
/* execvp() can only ever return if it fails */
sane_execvp("git", (char **)nargv.argv);
trace_printf("trace: exec failed: %s\n", strerror(errno));
argv_array_clear(&nargv);
return -1;
}
int execl_git_cmd(const char *cmd,...)
{
int argc;
const char *argv[MAX_ARGS + 1];
const char *arg;
va_list param;
va_start(param, cmd);
argv[0] = cmd;
argc = 1;
while (argc < MAX_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_ARGS <= argc)
return error("too many args to run %s", cmd);
argv[argc] = NULL;
return execv_git_cmd(argv);
}