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
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);
- return -ERR_RUN_COMMAND_PIPE;
+ goto fail_pipe;
}
cmd->in = fdin[1];
}
&& 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);
- return -ERR_RUN_COMMAND_PIPE;
+ 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_pair(fdout);
else if (cmd->out)
close(cmd->out);
- return -ERR_RUN_COMMAND_PIPE;
+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 __MINGW32__
+#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) {
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)
unsetenv(*cmd->env);
}
}
- if (cmd->preexec_cb)
+ 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);
}
- trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
- strerror(errno));
- exit(127);
+ /*
+ * 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], ¬ify_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 s0 = -1, s1 = -1, s2 = -1; /* backups of stdin, stdout, stderr */
+{
+ int fhin = 0, fhout = 1, fherr = 2;
const char **sargv = cmd->argv;
char **env = environ;
- if (cmd->no_stdin) {
- s0 = dup(0);
- dup_devnull(0);
- } else if (need_in) {
- s0 = dup(0);
- dup2(fdin[0], 0);
- } else if (cmd->in) {
- s0 = dup(0);
- dup2(cmd->in, 0);
- }
-
- if (cmd->no_stderr) {
- s2 = dup(2);
- dup_devnull(2);
- } else if (need_err) {
- s2 = dup(2);
- dup2(fderr[1], 2);
- }
-
- if (cmd->no_stdout) {
- s1 = dup(1);
- dup_devnull(1);
- } else if (cmd->stdout_to_stderr) {
- s1 = dup(1);
- dup2(2, 1);
- } else if (need_out) {
- s1 = dup(1);
- dup2(fdout[1], 1);
- } else if (cmd->out > 1) {
- s1 = dup(1);
- dup2(cmd->out, 1);
- }
+ 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 = copy_environ();
- for (; *cmd->env; cmd->env++)
- env = env_setenv(env, *cmd->env);
- }
+ 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);
+ cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env, cmd->dir,
+ 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);
free(cmd->argv);
cmd->argv = sargv;
- if (s0 >= 0)
- dup2(s0, 0), close(s0);
- if (s1 >= 0)
- dup2(s1, 1), close(s1);
- if (s2 >= 0)
- dup2(s2, 2), close(s2);
+ if (fhin != 0)
+ close(fhin);
+ if (fhout != 1)
+ close(fhout);
+ if (fherr != 2)
+ close(fherr);
+}
#endif
if (cmd->pid < 0) {
- int err = errno;
if (need_in)
close_pair(fdin);
else if (cmd->in)
close(cmd->out);
if (need_err)
close_pair(fderr);
- return err == ENOENT ?
- -ERR_RUN_COMMAND_EXEC :
- -ERR_RUN_COMMAND_FORK;
+ errno = failed_errno;
+ return -1;
}
if (need_in)
if (need_err)
close(fderr[1]);
+ else if (cmd->err)
+ close(cmd->err);
return 0;
}
-static int wait_or_whine(pid_t pid)
-{
- for (;;) {
- int status, code;
- pid_t waiting = waitpid(pid, &status, 0);
-
- if (waiting < 0) {
- if (errno == EINTR)
- continue;
- error("waitpid failed (%s)", strerror(errno));
- return -ERR_RUN_COMMAND_WAITPID;
- }
- if (waiting != pid)
- return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
- if (WIFSIGNALED(status))
- return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
-
- if (!WIFEXITED(status))
- return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
- code = WEXITSTATUS(status);
- switch (code) {
- case 127:
- return -ERR_RUN_COMMAND_EXEC;
- case 0:
- return 0;
- default:
- return -code;
- }
- }
-}
-
int finish_command(struct child_process *cmd)
{
- return wait_or_whine(cmd->pid);
+ return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
}
int run_command(struct child_process *cmd)
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)
return run_command(&cmd);
}
-#ifdef __MINGW32__
-static __stdcall unsigned run_thread(void *data)
+#ifdef WIN32
+static unsigned __stdcall run_thread(void *data)
{
struct async *async = data;
- return async->proc(async->fd_for_proc, async->data);
+ return async->proc(async->proc_in, async->proc_out, async->data);
}
#endif
int start_async(struct async *async)
{
- int pipe_out[2];
+ 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 (pipe(pipe_out) < 0)
- return error("cannot create pipe: %s", strerror(errno));
- async->out = pipe_out[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 __MINGW32__
+#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));
- close_pair(pipe_out);
- return -1;
+ goto error;
}
if (!async->pid) {
- close(pipe_out[0]);
- exit(!!async->proc(pipe_out[1], async->data));
+ if (need_in)
+ close(fdin[1]);
+ if (need_out)
+ close(fdout[0]);
+ exit(!!async->proc(proc_in, proc_out, async->data));
}
- close(pipe_out[1]);
+
+ 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->fd_for_proc = pipe_out[1];
+ 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));
- close_pair(pipe_out);
- return -1;
+ 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 __MINGW32__
- int ret = 0;
-
- if (wait_or_whine(async->pid))
- ret = error("waitpid (async) failed");
+#ifndef WIN32
+ int ret = wait_or_whine(async->pid, "child process", 0);
#else
DWORD ret = 0;
if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
hook.env = env;
}
- ret = start_command(&hook);
+ ret = run_command(&hook);
free(argv);
- if (ret) {
- warning("Could not spawn %s", argv[0]);
- return ret;
- }
- ret = finish_command(&hook);
- if (ret == -ERR_RUN_COMMAND_WAITPID_SIGNAL)
- warning("%s exited due to uncaught signal", argv[0]);
-
return ret;
}