git/run-command.c
Junio C Hamano 6eb3adff9e Merge branch 'mw/maint-gcc-warns-unused-write' into maint
* mw/maint-gcc-warns-unused-write:
  run-command.c: fix build warnings on Ubuntu
2010-03-08 00:36:02 -08:00

603 lines
13 KiB
C

#include "cache.h"
#include "run-command.h"
#include "exec_cmd.h"
static inline void close_pair(int fd[2])
{
close(fd[0]);
close(fd[1]);
}
#ifndef WIN32
static inline void dup_devnull(int to)
{
int fd = open("/dev/null", O_RDWR);
dup2(fd, to);
close(fd);
}
#endif
static const char **prepare_shell_cmd(const char **argv)
{
int argc, nargc = 0;
const char **nargv;
for (argc = 0; argv[argc]; argc++)
; /* just counting */
/* +1 for NULL, +3 for "sh -c" plus extra $0 */
nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
if (argc < 1)
die("BUG: shell command is empty");
if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
nargv[nargc++] = "sh";
nargv[nargc++] = "-c";
if (argc < 2)
nargv[nargc++] = argv[0];
else {
struct strbuf arg0 = STRBUF_INIT;
strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
nargv[nargc++] = strbuf_detach(&arg0, NULL);
}
}
for (argc = 0; argv[argc]; argc++)
nargv[nargc++] = argv[argc];
nargv[nargc] = NULL;
return nargv;
}
#ifndef WIN32
static int execv_shell_cmd(const char **argv)
{
const char **nargv = prepare_shell_cmd(argv);
trace_argv_printf(nargv, "trace: exec:");
execvp(nargv[0], (char **)nargv);
free(nargv);
return -1;
}
#endif
#ifndef WIN32
static int child_err = 2;
static int child_notifier = -1;
static void notify_parent(void)
{
ssize_t unused;
unused = write(child_notifier, "", 1);
}
static NORETURN void die_child(const char *err, va_list params)
{
char msg[4096];
ssize_t unused;
int len = vsnprintf(msg, sizeof(msg), err, params);
if (len > sizeof(msg))
len = sizeof(msg);
unused = write(child_err, "fatal: ", 7);
unused = write(child_err, msg, len);
unused = write(child_err, "\n", 1);
exit(128);
}
static inline void set_cloexec(int fd)
{
int flags = fcntl(fd, F_GETFD);
if (flags >= 0)
fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
}
#endif
static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
{
int status, code = -1;
pid_t waiting;
int failed_errno = 0;
while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
; /* nothing */
if (waiting < 0) {
failed_errno = errno;
error("waitpid for %s failed: %s", argv0, strerror(errno));
} else if (waiting != pid) {
error("waitpid is confused (%s)", argv0);
} else if (WIFSIGNALED(status)) {
code = WTERMSIG(status);
error("%s died of signal %d", argv0, code);
/*
* This return value is chosen so that code & 0xff
* mimics the exit code that a POSIX shell would report for
* a program that died from this signal.
*/
code -= 128;
} else if (WIFEXITED(status)) {
code = WEXITSTATUS(status);
/*
* Convert special exit code when execvp failed.
*/
if (code == 127) {
code = -1;
failed_errno = ENOENT;
if (!silent_exec_failure)
error("cannot run %s: %s", argv0,
strerror(ENOENT));
}
} else {
error("waitpid is confused (%s)", argv0);
}
errno = failed_errno;
return code;
}
int start_command(struct child_process *cmd)
{
int need_in, need_out, need_err;
int fdin[2], fdout[2], fderr[2];
int failed_errno = failed_errno;
/*
* In case of errors we must keep the promise to close FDs
* that have been passed in via ->in and ->out.
*/
need_in = !cmd->no_stdin && cmd->in < 0;
if (need_in) {
if (pipe(fdin) < 0) {
failed_errno = errno;
if (cmd->out > 0)
close(cmd->out);
goto fail_pipe;
}
cmd->in = fdin[1];
}
need_out = !cmd->no_stdout
&& !cmd->stdout_to_stderr
&& cmd->out < 0;
if (need_out) {
if (pipe(fdout) < 0) {
failed_errno = errno;
if (need_in)
close_pair(fdin);
else if (cmd->in)
close(cmd->in);
goto fail_pipe;
}
cmd->out = fdout[0];
}
need_err = !cmd->no_stderr && cmd->err < 0;
if (need_err) {
if (pipe(fderr) < 0) {
failed_errno = errno;
if (need_in)
close_pair(fdin);
else if (cmd->in)
close(cmd->in);
if (need_out)
close_pair(fdout);
else if (cmd->out)
close(cmd->out);
fail_pipe:
error("cannot create pipe for %s: %s",
cmd->argv[0], strerror(failed_errno));
errno = failed_errno;
return -1;
}
cmd->err = fderr[0];
}
trace_argv_printf(cmd->argv, "trace: run_command:");
#ifndef WIN32
{
int notify_pipe[2];
if (pipe(notify_pipe))
notify_pipe[0] = notify_pipe[1] = -1;
fflush(NULL);
cmd->pid = fork();
if (!cmd->pid) {
/*
* Redirect the channel to write syscall error messages to
* before redirecting the process's stderr so that all die()
* in subsequent call paths use the parent's stderr.
*/
if (cmd->no_stderr || need_err) {
child_err = dup(2);
set_cloexec(child_err);
}
set_die_routine(die_child);
close(notify_pipe[0]);
set_cloexec(notify_pipe[1]);
child_notifier = notify_pipe[1];
atexit(notify_parent);
if (cmd->no_stdin)
dup_devnull(0);
else if (need_in) {
dup2(fdin[0], 0);
close_pair(fdin);
} else if (cmd->in) {
dup2(cmd->in, 0);
close(cmd->in);
}
if (cmd->no_stderr)
dup_devnull(2);
else if (need_err) {
dup2(fderr[1], 2);
close_pair(fderr);
} else if (cmd->err > 1) {
dup2(cmd->err, 2);
close(cmd->err);
}
if (cmd->no_stdout)
dup_devnull(1);
else if (cmd->stdout_to_stderr)
dup2(2, 1);
else if (need_out) {
dup2(fdout[1], 1);
close_pair(fdout);
} else if (cmd->out > 1) {
dup2(cmd->out, 1);
close(cmd->out);
}
if (cmd->dir && chdir(cmd->dir))
die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
cmd->dir);
if (cmd->env) {
for (; *cmd->env; cmd->env++) {
if (strchr(*cmd->env, '='))
putenv((char *)*cmd->env);
else
unsetenv(*cmd->env);
}
}
if (cmd->preexec_cb) {
/*
* We cannot predict what the pre-exec callback does.
* Forgo parent notification.
*/
close(child_notifier);
child_notifier = -1;
cmd->preexec_cb();
}
if (cmd->git_cmd) {
execv_git_cmd(cmd->argv);
} else if (cmd->use_shell) {
execv_shell_cmd(cmd->argv);
} else {
execvp(cmd->argv[0], (char *const*) cmd->argv);
}
/*
* Do not check for cmd->silent_exec_failure; the parent
* process will check it when it sees this exit code.
*/
if (errno == ENOENT)
exit(127);
else
die_errno("cannot exec '%s'", cmd->argv[0]);
}
if (cmd->pid < 0)
error("cannot fork() for %s: %s", cmd->argv[0],
strerror(failed_errno = errno));
/*
* Wait for child's execvp. If the execvp succeeds (or if fork()
* failed), EOF is seen immediately by the parent. Otherwise, the
* child process sends a single byte.
* Note that use of this infrastructure is completely advisory,
* therefore, we keep error checks minimal.
*/
close(notify_pipe[1]);
if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
/*
* At this point we know that fork() succeeded, but execvp()
* failed. Errors have been reported to our stderr.
*/
wait_or_whine(cmd->pid, cmd->argv[0],
cmd->silent_exec_failure);
failed_errno = errno;
cmd->pid = -1;
}
close(notify_pipe[0]);
}
#else
{
int fhin = 0, fhout = 1, fherr = 2;
const char **sargv = cmd->argv;
char **env = environ;
if (cmd->no_stdin)
fhin = open("/dev/null", O_RDWR);
else if (need_in)
fhin = dup(fdin[0]);
else if (cmd->in)
fhin = dup(cmd->in);
if (cmd->no_stderr)
fherr = open("/dev/null", O_RDWR);
else if (need_err)
fherr = dup(fderr[1]);
else if (cmd->err > 2)
fherr = dup(cmd->err);
if (cmd->no_stdout)
fhout = open("/dev/null", O_RDWR);
else if (cmd->stdout_to_stderr)
fhout = dup(fherr);
else if (need_out)
fhout = dup(fdout[1]);
else if (cmd->out > 1)
fhout = dup(cmd->out);
if (cmd->dir)
die("chdir in start_command() not implemented");
if (cmd->env)
env = make_augmented_environ(cmd->env);
if (cmd->git_cmd) {
cmd->argv = prepare_git_cmd(cmd->argv);
} else if (cmd->use_shell) {
cmd->argv = prepare_shell_cmd(cmd->argv);
}
cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
fhin, fhout, fherr);
failed_errno = errno;
if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
if (cmd->env)
free_environ(env);
if (cmd->git_cmd)
free(cmd->argv);
cmd->argv = sargv;
if (fhin != 0)
close(fhin);
if (fhout != 1)
close(fhout);
if (fherr != 2)
close(fherr);
}
#endif
if (cmd->pid < 0) {
if (need_in)
close_pair(fdin);
else if (cmd->in)
close(cmd->in);
if (need_out)
close_pair(fdout);
else if (cmd->out)
close(cmd->out);
if (need_err)
close_pair(fderr);
errno = failed_errno;
return -1;
}
if (need_in)
close(fdin[0]);
else if (cmd->in)
close(cmd->in);
if (need_out)
close(fdout[1]);
else if (cmd->out)
close(cmd->out);
if (need_err)
close(fderr[1]);
else if (cmd->err)
close(cmd->err);
return 0;
}
int finish_command(struct child_process *cmd)
{
return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
}
int run_command(struct child_process *cmd)
{
int code = start_command(cmd);
if (code)
return code;
return finish_command(cmd);
}
static void prepare_run_command_v_opt(struct child_process *cmd,
const char **argv,
int opt)
{
memset(cmd, 0, sizeof(*cmd));
cmd->argv = argv;
cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
}
int run_command_v_opt(const char **argv, int opt)
{
struct child_process cmd;
prepare_run_command_v_opt(&cmd, argv, opt);
return run_command(&cmd);
}
int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
{
struct child_process cmd;
prepare_run_command_v_opt(&cmd, argv, opt);
cmd.dir = dir;
cmd.env = env;
return run_command(&cmd);
}
#ifdef WIN32
static unsigned __stdcall run_thread(void *data)
{
struct async *async = data;
return async->proc(async->proc_in, async->proc_out, async->data);
}
#endif
int start_async(struct async *async)
{
int need_in, need_out;
int fdin[2], fdout[2];
int proc_in, proc_out;
need_in = async->in < 0;
if (need_in) {
if (pipe(fdin) < 0) {
if (async->out > 0)
close(async->out);
return error("cannot create pipe: %s", strerror(errno));
}
async->in = fdin[1];
}
need_out = async->out < 0;
if (need_out) {
if (pipe(fdout) < 0) {
if (need_in)
close_pair(fdin);
else if (async->in)
close(async->in);
return error("cannot create pipe: %s", strerror(errno));
}
async->out = fdout[0];
}
if (need_in)
proc_in = fdin[0];
else if (async->in)
proc_in = async->in;
else
proc_in = -1;
if (need_out)
proc_out = fdout[1];
else if (async->out)
proc_out = async->out;
else
proc_out = -1;
#ifndef WIN32
/* Flush stdio before fork() to avoid cloning buffers */
fflush(NULL);
async->pid = fork();
if (async->pid < 0) {
error("fork (async) failed: %s", strerror(errno));
goto error;
}
if (!async->pid) {
if (need_in)
close(fdin[1]);
if (need_out)
close(fdout[0]);
exit(!!async->proc(proc_in, proc_out, async->data));
}
if (need_in)
close(fdin[0]);
else if (async->in)
close(async->in);
if (need_out)
close(fdout[1]);
else if (async->out)
close(async->out);
#else
async->proc_in = proc_in;
async->proc_out = proc_out;
async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
if (!async->tid) {
error("cannot create thread: %s", strerror(errno));
goto error;
}
#endif
return 0;
error:
if (need_in)
close_pair(fdin);
else if (async->in)
close(async->in);
if (need_out)
close_pair(fdout);
else if (async->out)
close(async->out);
return -1;
}
int finish_async(struct async *async)
{
#ifndef WIN32
int ret = wait_or_whine(async->pid, "child process", 0);
#else
DWORD ret = 0;
if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
ret = error("waiting for thread failed: %lu", GetLastError());
else if (!GetExitCodeThread(async->tid, &ret))
ret = error("cannot get thread exit code: %lu", GetLastError());
CloseHandle(async->tid);
#endif
return ret;
}
int run_hook(const char *index_file, const char *name, ...)
{
struct child_process hook;
const char **argv = NULL, *env[2];
char index[PATH_MAX];
va_list args;
int ret;
size_t i = 0, alloc = 0;
if (access(git_path("hooks/%s", name), X_OK) < 0)
return 0;
va_start(args, name);
ALLOC_GROW(argv, i + 1, alloc);
argv[i++] = git_path("hooks/%s", name);
while (argv[i-1]) {
ALLOC_GROW(argv, i + 1, alloc);
argv[i++] = va_arg(args, const char *);
}
va_end(args);
memset(&hook, 0, sizeof(hook));
hook.argv = argv;
hook.no_stdin = 1;
hook.stdout_to_stderr = 1;
if (index_file) {
snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
env[0] = index;
env[1] = NULL;
hook.env = env;
}
ret = run_command(&hook);
free(argv);
return ret;
}