Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "run-command.h"
   3#include "exec_cmd.h"
   4
   5static inline void close_pair(int fd[2])
   6{
   7        close(fd[0]);
   8        close(fd[1]);
   9}
  10
  11static inline void dup_devnull(int to)
  12{
  13        int fd = open("/dev/null", O_RDWR);
  14        dup2(fd, to);
  15        close(fd);
  16}
  17
  18#ifndef WIN32
  19static int child_err = 2;
  20
  21static NORETURN void die_child(const char *err, va_list params)
  22{
  23        char msg[4096];
  24        int len = vsnprintf(msg, sizeof(msg), err, params);
  25        if (len > sizeof(msg))
  26                len = sizeof(msg);
  27
  28        write(child_err, "fatal: ", 7);
  29        write(child_err, msg, len);
  30        write(child_err, "\n", 1);
  31        exit(128);
  32}
  33
  34static inline void set_cloexec(int fd)
  35{
  36        int flags = fcntl(fd, F_GETFD);
  37        if (flags >= 0)
  38                fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  39}
  40#endif
  41
  42static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
  43{
  44        int status, code = -1;
  45        pid_t waiting;
  46        int failed_errno = 0;
  47
  48        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
  49                ;       /* nothing */
  50
  51        if (waiting < 0) {
  52                failed_errno = errno;
  53                error("waitpid for %s failed: %s", argv0, strerror(errno));
  54        } else if (waiting != pid) {
  55                error("waitpid is confused (%s)", argv0);
  56        } else if (WIFSIGNALED(status)) {
  57                code = WTERMSIG(status);
  58                error("%s died of signal %d", argv0, code);
  59                /*
  60                 * This return value is chosen so that code & 0xff
  61                 * mimics the exit code that a POSIX shell would report for
  62                 * a program that died from this signal.
  63                 */
  64                code -= 128;
  65        } else if (WIFEXITED(status)) {
  66                code = WEXITSTATUS(status);
  67                /*
  68                 * Convert special exit code when execvp failed.
  69                 */
  70                if (code == 127) {
  71                        code = -1;
  72                        failed_errno = ENOENT;
  73                        if (!silent_exec_failure)
  74                                error("cannot run %s: %s", argv0,
  75                                        strerror(ENOENT));
  76                }
  77        } else {
  78                error("waitpid is confused (%s)", argv0);
  79        }
  80        errno = failed_errno;
  81        return code;
  82}
  83
  84int start_command(struct child_process *cmd)
  85{
  86        int need_in, need_out, need_err;
  87        int fdin[2], fdout[2], fderr[2];
  88        int failed_errno = failed_errno;
  89
  90        /*
  91         * In case of errors we must keep the promise to close FDs
  92         * that have been passed in via ->in and ->out.
  93         */
  94
  95        need_in = !cmd->no_stdin && cmd->in < 0;
  96        if (need_in) {
  97                if (pipe(fdin) < 0) {
  98                        failed_errno = errno;
  99                        if (cmd->out > 0)
 100                                close(cmd->out);
 101                        goto fail_pipe;
 102                }
 103                cmd->in = fdin[1];
 104        }
 105
 106        need_out = !cmd->no_stdout
 107                && !cmd->stdout_to_stderr
 108                && cmd->out < 0;
 109        if (need_out) {
 110                if (pipe(fdout) < 0) {
 111                        failed_errno = errno;
 112                        if (need_in)
 113                                close_pair(fdin);
 114                        else if (cmd->in)
 115                                close(cmd->in);
 116                        goto fail_pipe;
 117                }
 118                cmd->out = fdout[0];
 119        }
 120
 121        need_err = !cmd->no_stderr && cmd->err < 0;
 122        if (need_err) {
 123                if (pipe(fderr) < 0) {
 124                        failed_errno = errno;
 125                        if (need_in)
 126                                close_pair(fdin);
 127                        else if (cmd->in)
 128                                close(cmd->in);
 129                        if (need_out)
 130                                close_pair(fdout);
 131                        else if (cmd->out)
 132                                close(cmd->out);
 133fail_pipe:
 134                        error("cannot create pipe for %s: %s",
 135                                cmd->argv[0], strerror(failed_errno));
 136                        errno = failed_errno;
 137                        return -1;
 138                }
 139                cmd->err = fderr[0];
 140        }
 141
 142        trace_argv_printf(cmd->argv, "trace: run_command:");
 143
 144#ifndef WIN32
 145        fflush(NULL);
 146        cmd->pid = fork();
 147        if (!cmd->pid) {
 148                /*
 149                 * Redirect the channel to write syscall error messages to
 150                 * before redirecting the process's stderr so that all die()
 151                 * in subsequent call paths use the parent's stderr.
 152                 */
 153                if (cmd->no_stderr || need_err) {
 154                        child_err = dup(2);
 155                        set_cloexec(child_err);
 156                }
 157                set_die_routine(die_child);
 158
 159                if (cmd->no_stdin)
 160                        dup_devnull(0);
 161                else if (need_in) {
 162                        dup2(fdin[0], 0);
 163                        close_pair(fdin);
 164                } else if (cmd->in) {
 165                        dup2(cmd->in, 0);
 166                        close(cmd->in);
 167                }
 168
 169                if (cmd->no_stderr)
 170                        dup_devnull(2);
 171                else if (need_err) {
 172                        dup2(fderr[1], 2);
 173                        close_pair(fderr);
 174                }
 175
 176                if (cmd->no_stdout)
 177                        dup_devnull(1);
 178                else if (cmd->stdout_to_stderr)
 179                        dup2(2, 1);
 180                else if (need_out) {
 181                        dup2(fdout[1], 1);
 182                        close_pair(fdout);
 183                } else if (cmd->out > 1) {
 184                        dup2(cmd->out, 1);
 185                        close(cmd->out);
 186                }
 187
 188                if (cmd->dir && chdir(cmd->dir))
 189                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 190                            cmd->dir);
 191                if (cmd->env) {
 192                        for (; *cmd->env; cmd->env++) {
 193                                if (strchr(*cmd->env, '='))
 194                                        putenv((char *)*cmd->env);
 195                                else
 196                                        unsetenv(*cmd->env);
 197                        }
 198                }
 199                if (cmd->preexec_cb)
 200                        cmd->preexec_cb();
 201                if (cmd->git_cmd) {
 202                        execv_git_cmd(cmd->argv);
 203                } else {
 204                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 205                }
 206                /*
 207                 * Do not check for cmd->silent_exec_failure; the parent
 208                 * process will check it when it sees this exit code.
 209                 */
 210                if (errno == ENOENT)
 211                        exit(127);
 212                else
 213                        die_errno("cannot exec '%s'", cmd->argv[0]);
 214        }
 215        if (cmd->pid < 0)
 216                error("cannot fork() for %s: %s", cmd->argv[0],
 217                        strerror(failed_errno = errno));
 218#else
 219{
 220        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 221        const char **sargv = cmd->argv;
 222        char **env = environ;
 223
 224        if (cmd->no_stdin) {
 225                s0 = dup(0);
 226                dup_devnull(0);
 227        } else if (need_in) {
 228                s0 = dup(0);
 229                dup2(fdin[0], 0);
 230        } else if (cmd->in) {
 231                s0 = dup(0);
 232                dup2(cmd->in, 0);
 233        }
 234
 235        if (cmd->no_stderr) {
 236                s2 = dup(2);
 237                dup_devnull(2);
 238        } else if (need_err) {
 239                s2 = dup(2);
 240                dup2(fderr[1], 2);
 241        }
 242
 243        if (cmd->no_stdout) {
 244                s1 = dup(1);
 245                dup_devnull(1);
 246        } else if (cmd->stdout_to_stderr) {
 247                s1 = dup(1);
 248                dup2(2, 1);
 249        } else if (need_out) {
 250                s1 = dup(1);
 251                dup2(fdout[1], 1);
 252        } else if (cmd->out > 1) {
 253                s1 = dup(1);
 254                dup2(cmd->out, 1);
 255        }
 256
 257        if (cmd->dir)
 258                die("chdir in start_command() not implemented");
 259        if (cmd->env)
 260                env = make_augmented_environ(cmd->env);
 261
 262        if (cmd->git_cmd) {
 263                cmd->argv = prepare_git_cmd(cmd->argv);
 264        }
 265
 266        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 267        failed_errno = errno;
 268        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 269                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 270
 271        if (cmd->env)
 272                free_environ(env);
 273        if (cmd->git_cmd)
 274                free(cmd->argv);
 275
 276        cmd->argv = sargv;
 277        if (s0 >= 0)
 278                dup2(s0, 0), close(s0);
 279        if (s1 >= 0)
 280                dup2(s1, 1), close(s1);
 281        if (s2 >= 0)
 282                dup2(s2, 2), close(s2);
 283}
 284#endif
 285
 286        if (cmd->pid < 0) {
 287                if (need_in)
 288                        close_pair(fdin);
 289                else if (cmd->in)
 290                        close(cmd->in);
 291                if (need_out)
 292                        close_pair(fdout);
 293                else if (cmd->out)
 294                        close(cmd->out);
 295                if (need_err)
 296                        close_pair(fderr);
 297                errno = failed_errno;
 298                return -1;
 299        }
 300
 301        if (need_in)
 302                close(fdin[0]);
 303        else if (cmd->in)
 304                close(cmd->in);
 305
 306        if (need_out)
 307                close(fdout[1]);
 308        else if (cmd->out)
 309                close(cmd->out);
 310
 311        if (need_err)
 312                close(fderr[1]);
 313
 314        return 0;
 315}
 316
 317int finish_command(struct child_process *cmd)
 318{
 319        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 320}
 321
 322int run_command(struct child_process *cmd)
 323{
 324        int code = start_command(cmd);
 325        if (code)
 326                return code;
 327        return finish_command(cmd);
 328}
 329
 330static void prepare_run_command_v_opt(struct child_process *cmd,
 331                                      const char **argv,
 332                                      int opt)
 333{
 334        memset(cmd, 0, sizeof(*cmd));
 335        cmd->argv = argv;
 336        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 337        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 338        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 339        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 340}
 341
 342int run_command_v_opt(const char **argv, int opt)
 343{
 344        struct child_process cmd;
 345        prepare_run_command_v_opt(&cmd, argv, opt);
 346        return run_command(&cmd);
 347}
 348
 349int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 350{
 351        struct child_process cmd;
 352        prepare_run_command_v_opt(&cmd, argv, opt);
 353        cmd.dir = dir;
 354        cmd.env = env;
 355        return run_command(&cmd);
 356}
 357
 358#ifdef WIN32
 359static unsigned __stdcall run_thread(void *data)
 360{
 361        struct async *async = data;
 362        return async->proc(async->fd_for_proc, async->data);
 363}
 364#endif
 365
 366int start_async(struct async *async)
 367{
 368        int pipe_out[2];
 369
 370        if (pipe(pipe_out) < 0)
 371                return error("cannot create pipe: %s", strerror(errno));
 372        async->out = pipe_out[0];
 373
 374#ifndef WIN32
 375        /* Flush stdio before fork() to avoid cloning buffers */
 376        fflush(NULL);
 377
 378        async->pid = fork();
 379        if (async->pid < 0) {
 380                error("fork (async) failed: %s", strerror(errno));
 381                close_pair(pipe_out);
 382                return -1;
 383        }
 384        if (!async->pid) {
 385                close(pipe_out[0]);
 386                exit(!!async->proc(pipe_out[1], async->data));
 387        }
 388        close(pipe_out[1]);
 389#else
 390        async->fd_for_proc = pipe_out[1];
 391        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 392        if (!async->tid) {
 393                error("cannot create thread: %s", strerror(errno));
 394                close_pair(pipe_out);
 395                return -1;
 396        }
 397#endif
 398        return 0;
 399}
 400
 401int finish_async(struct async *async)
 402{
 403#ifndef WIN32
 404        int ret = wait_or_whine(async->pid, "child process", 0);
 405#else
 406        DWORD ret = 0;
 407        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 408                ret = error("waiting for thread failed: %lu", GetLastError());
 409        else if (!GetExitCodeThread(async->tid, &ret))
 410                ret = error("cannot get thread exit code: %lu", GetLastError());
 411        CloseHandle(async->tid);
 412#endif
 413        return ret;
 414}
 415
 416int run_hook(const char *index_file, const char *name, ...)
 417{
 418        struct child_process hook;
 419        const char **argv = NULL, *env[2];
 420        char index[PATH_MAX];
 421        va_list args;
 422        int ret;
 423        size_t i = 0, alloc = 0;
 424
 425        if (access(git_path("hooks/%s", name), X_OK) < 0)
 426                return 0;
 427
 428        va_start(args, name);
 429        ALLOC_GROW(argv, i + 1, alloc);
 430        argv[i++] = git_path("hooks/%s", name);
 431        while (argv[i-1]) {
 432                ALLOC_GROW(argv, i + 1, alloc);
 433                argv[i++] = va_arg(args, const char *);
 434        }
 435        va_end(args);
 436
 437        memset(&hook, 0, sizeof(hook));
 438        hook.argv = argv;
 439        hook.no_stdin = 1;
 440        hook.stdout_to_stderr = 1;
 441        if (index_file) {
 442                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 443                env[0] = index;
 444                env[1] = NULL;
 445                hook.env = env;
 446        }
 447
 448        ret = run_command(&hook);
 449        free(argv);
 450        return ret;
 451}