]> git.ipfire.org Git - thirdparty/git.git/blobdiff - run-command.c
Git 1.7.8-rc2
[thirdparty/git.git] / run-command.c
index eb2efc33073512efd14b65e67db8cf814ca3fa33..1c5104388429e50722769358d5d89948c55bb3aa 100644 (file)
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "run-command.h"
 #include "exec_cmd.h"
+#include "argv-array.h"
 
 static inline void close_pair(int fd[2])
 {
@@ -8,17 +9,136 @@ static inline void close_pair(int fd[2])
        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)
+{
+       /*
+        * execvp failed.  If possible, we'd like to let start_command
+        * know, so failures like ENOENT can be handled right away; but
+        * otherwise, finish_command will still report the error.
+        */
+       xwrite(child_notifier, "", 1);
+}
+
+static NORETURN void die_child(const char *err, va_list params)
+{
+       vwritef(child_err, "fatal: ", err, params);
+       exit(128);
+}
+
+static void error_child(const char *err, va_list params)
+{
+       vwritef(child_err, "error: ", err, params);
+}
+#endif
+
+static inline void set_cloexec(int fd)
+{
+       int flags = fcntl(fd, F_GETFD);
+       if (flags >= 0)
+               fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+}
+
+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;
+               }
+       } 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
@@ -28,9 +148,10 @@ int start_command(struct child_process *cmd)
        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];
        }
@@ -40,11 +161,12 @@ int start_command(struct child_process *cmd)
                && 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];
        }
@@ -52,6 +174,7 @@ int start_command(struct child_process *cmd)
        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)
@@ -60,17 +183,43 @@ int start_command(struct child_process *cmd)
                                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__
        fflush(NULL);
+
+#ifndef WIN32
+{
+       int notify_pipe[2];
+       if (pipe(notify_pipe))
+               notify_pipe[0] = notify_pipe[1] = -1;
+
        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);
+               set_error_routine(error_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) {
@@ -86,6 +235,9 @@ int start_command(struct child_process *cmd)
                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)
@@ -101,8 +253,8 @@ int start_command(struct child_process *cmd)
                }
 
                if (cmd->dir && chdir(cmd->dir))
-                       die("exec %s: cd to %s failed (%s)", cmd->argv[0],
-                           cmd->dir, strerror(errno));
+                       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, '='))
@@ -111,68 +263,99 @@ int start_command(struct child_process *cmd)
                                        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);
+               if (errno == ENOENT) {
+                       if (!cmd->silent_exec_failure)
+                               error("cannot run %s: %s", cmd->argv[0],
+                                       strerror(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 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);
@@ -180,16 +363,16 @@ int start_command(struct child_process *cmd)
                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)
@@ -200,9 +383,10 @@ int start_command(struct child_process *cmd)
                        close(cmd->out);
                if (need_err)
                        close_pair(fderr);
-               return err == ENOENT ?
-                       -ERR_RUN_COMMAND_EXEC :
-                       -ERR_RUN_COMMAND_FORK;
+               else if (cmd->err)
+                       close(cmd->err);
+               errno = failed_errno;
+               return -1;
        }
 
        if (need_in)
@@ -217,44 +401,15 @@ int start_command(struct child_process *cmd)
 
        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)
@@ -274,6 +429,8 @@ static void prepare_run_command_v_opt(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)
@@ -292,90 +449,180 @@ int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const
        return run_command(&cmd);
 }
 
-#ifdef __MINGW32__
-static __stdcall unsigned run_thread(void *data)
+#ifndef NO_PTHREADS
+static pthread_t main_thread;
+static int main_thread_set;
+static pthread_key_t async_key;
+
+static void *run_thread(void *data)
 {
        struct async *async = data;
-       return async->proc(async->fd_for_proc, async->data);
+       intptr_t ret;
+
+       pthread_setspecific(async_key, async);
+       ret = async->proc(async->proc_in, async->proc_out, async->data);
+       return (void *)ret;
+}
+
+static NORETURN void die_async(const char *err, va_list params)
+{
+       vreportf("fatal: ", err, params);
+
+       if (!pthread_equal(main_thread, pthread_self())) {
+               struct async *async = pthread_getspecific(async_key);
+               if (async->proc_in >= 0)
+                       close(async->proc_in);
+               if (async->proc_out >= 0)
+                       close(async->proc_out);
+               pthread_exit((void *)128);
+       }
+
+       exit(128);
 }
 #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;
 
-       if (pipe(pipe_out) < 0)
-               return error("cannot create pipe: %s", strerror(errno));
-       async->out = pipe_out[0];
+       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];
+       }
 
-#ifndef __MINGW32__
+       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;
+
+#ifdef NO_PTHREADS
        /* 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->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;
+       if (!main_thread_set) {
+               /*
+                * We assume that the first time that start_async is called
+                * it is from the main thread.
+                */
+               main_thread_set = 1;
+               main_thread = pthread_self();
+               pthread_key_create(&async_key, NULL);
+               set_die_routine(die_async);
+       }
+
+       if (proc_in >= 0)
+               set_cloexec(proc_in);
+       if (proc_out >= 0)
+               set_cloexec(proc_out);
+       async->proc_in = proc_in;
+       async->proc_out = proc_out;
+       {
+               int err = pthread_create(&async->tid, NULL, run_thread, async);
+               if (err) {
+                       error("cannot create thread: %s", strerror(err));
+                       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");
+#ifdef NO_PTHREADS
+       return 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);
+       void *ret = (void *)(intptr_t)(-1);
+
+       if (pthread_join(async->tid, &ret))
+               error("pthread_join failed");
+       return (int)(intptr_t)ret;
 #endif
-       return ret;
 }
 
 int run_hook(const char *index_file, const char *name, ...)
 {
        struct child_process hook;
-       const char **argv = NULL, *env[2];
+       struct argv_array argv = ARGV_ARRAY_INIT;
+       const char *p, *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 *);
-       }
+       argv_array_push(&argv, git_path("hooks/%s", name));
+       while ((p = va_arg(args, const char *)))
+               argv_array_push(&argv, p);
        va_end(args);
 
        memset(&hook, 0, sizeof(hook));
-       hook.argv = argv;
+       hook.argv = argv.argv;
        hook.no_stdin = 1;
        hook.stdout_to_stderr = 1;
        if (index_file) {
@@ -385,15 +632,7 @@ int run_hook(const char *index_file, const char *name, ...)
                hook.env = env;
        }
 
-       ret = start_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]);
-
+       ret = run_command(&hook);
+       argv_array_clear(&argv);
        return ret;
 }