diff options
Diffstat (limited to 'run-command.c')
| -rw-r--r-- | run-command.c | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/run-command.c b/run-command.c new file mode 100644 index 000000000..2feb49395 --- /dev/null +++ b/run-command.c @@ -0,0 +1,536 @@ +#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) +{ + write(child_notifier, "", 1); +} + +static NORETURN void die_child(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(child_err, "fatal: ", 7); + write(child_err, msg, len); + 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); + } + + 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], ¬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 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]); + + 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]); + + 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->fd_for_proc, async->data); +} +#endif + +int start_async(struct async *async) +{ + int pipe_out[2]; + + if (pipe(pipe_out) < 0) + return error("cannot create pipe: %s", strerror(errno)); + async->out = pipe_out[0]; + +#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; + } + if (!async->pid) { + close(pipe_out[0]); + exit(!!async->proc(pipe_out[1], async->data)); + } + close(pipe_out[1]); +#else + async->fd_for_proc = pipe_out[1]; + 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; + } +#endif + return 0; +} + +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; +} |