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
  18int start_command(struct child_process *cmd)
  19{
  20        int need_in, need_out, need_err;
  21        int fdin[2], fdout[2], fderr[2];
  22        int failed_errno = failed_errno;
  23
  24        /*
  25         * In case of errors we must keep the promise to close FDs
  26         * that have been passed in via ->in and ->out.
  27         */
  28
  29        need_in = !cmd->no_stdin && cmd->in < 0;
  30        if (need_in) {
  31                if (pipe(fdin) < 0) {
  32                        failed_errno = errno;
  33                        if (cmd->out > 0)
  34                                close(cmd->out);
  35                        goto fail_pipe;
  36                }
  37                cmd->in = fdin[1];
  38        }
  39
  40        need_out = !cmd->no_stdout
  41                && !cmd->stdout_to_stderr
  42                && cmd->out < 0;
  43        if (need_out) {
  44                if (pipe(fdout) < 0) {
  45                        failed_errno = errno;
  46                        if (need_in)
  47                                close_pair(fdin);
  48                        else if (cmd->in)
  49                                close(cmd->in);
  50                        goto fail_pipe;
  51                }
  52                cmd->out = fdout[0];
  53        }
  54
  55        need_err = !cmd->no_stderr && cmd->err < 0;
  56        if (need_err) {
  57                if (pipe(fderr) < 0) {
  58                        failed_errno = errno;
  59                        if (need_in)
  60                                close_pair(fdin);
  61                        else if (cmd->in)
  62                                close(cmd->in);
  63                        if (need_out)
  64                                close_pair(fdout);
  65                        else if (cmd->out)
  66                                close(cmd->out);
  67fail_pipe:
  68                        error("cannot create pipe for %s: %s",
  69                                cmd->argv[0], strerror(failed_errno));
  70                        errno = failed_errno;
  71                        return -1;
  72                }
  73                cmd->err = fderr[0];
  74        }
  75
  76        trace_argv_printf(cmd->argv, "trace: run_command:");
  77
  78#ifndef __MINGW32__
  79        fflush(NULL);
  80        cmd->pid = fork();
  81        if (!cmd->pid) {
  82                if (cmd->no_stdin)
  83                        dup_devnull(0);
  84                else if (need_in) {
  85                        dup2(fdin[0], 0);
  86                        close_pair(fdin);
  87                } else if (cmd->in) {
  88                        dup2(cmd->in, 0);
  89                        close(cmd->in);
  90                }
  91
  92                if (cmd->no_stderr)
  93                        dup_devnull(2);
  94                else if (need_err) {
  95                        dup2(fderr[1], 2);
  96                        close_pair(fderr);
  97                }
  98
  99                if (cmd->no_stdout)
 100                        dup_devnull(1);
 101                else if (cmd->stdout_to_stderr)
 102                        dup2(2, 1);
 103                else if (need_out) {
 104                        dup2(fdout[1], 1);
 105                        close_pair(fdout);
 106                } else if (cmd->out > 1) {
 107                        dup2(cmd->out, 1);
 108                        close(cmd->out);
 109                }
 110
 111                if (cmd->dir && chdir(cmd->dir))
 112                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 113                            cmd->dir);
 114                if (cmd->env) {
 115                        for (; *cmd->env; cmd->env++) {
 116                                if (strchr(*cmd->env, '='))
 117                                        putenv((char *)*cmd->env);
 118                                else
 119                                        unsetenv(*cmd->env);
 120                        }
 121                }
 122                if (cmd->preexec_cb)
 123                        cmd->preexec_cb();
 124                if (cmd->git_cmd) {
 125                        execv_git_cmd(cmd->argv);
 126                } else {
 127                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 128                }
 129                trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
 130                                strerror(errno));
 131                exit(127);
 132        }
 133        if (cmd->pid < 0)
 134                error("cannot fork() for %s: %s", cmd->argv[0],
 135                        strerror(failed_errno = errno));
 136#else
 137        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 138        const char **sargv = cmd->argv;
 139        char **env = environ;
 140
 141        if (cmd->no_stdin) {
 142                s0 = dup(0);
 143                dup_devnull(0);
 144        } else if (need_in) {
 145                s0 = dup(0);
 146                dup2(fdin[0], 0);
 147        } else if (cmd->in) {
 148                s0 = dup(0);
 149                dup2(cmd->in, 0);
 150        }
 151
 152        if (cmd->no_stderr) {
 153                s2 = dup(2);
 154                dup_devnull(2);
 155        } else if (need_err) {
 156                s2 = dup(2);
 157                dup2(fderr[1], 2);
 158        }
 159
 160        if (cmd->no_stdout) {
 161                s1 = dup(1);
 162                dup_devnull(1);
 163        } else if (cmd->stdout_to_stderr) {
 164                s1 = dup(1);
 165                dup2(2, 1);
 166        } else if (need_out) {
 167                s1 = dup(1);
 168                dup2(fdout[1], 1);
 169        } else if (cmd->out > 1) {
 170                s1 = dup(1);
 171                dup2(cmd->out, 1);
 172        }
 173
 174        if (cmd->dir)
 175                die("chdir in start_command() not implemented");
 176        if (cmd->env)
 177                env = make_augmented_environ(cmd->env);
 178
 179        if (cmd->git_cmd) {
 180                cmd->argv = prepare_git_cmd(cmd->argv);
 181        }
 182
 183        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 184        failed_errno = errno;
 185        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 186                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 187
 188        if (cmd->env)
 189                free_environ(env);
 190        if (cmd->git_cmd)
 191                free(cmd->argv);
 192
 193        cmd->argv = sargv;
 194        if (s0 >= 0)
 195                dup2(s0, 0), close(s0);
 196        if (s1 >= 0)
 197                dup2(s1, 1), close(s1);
 198        if (s2 >= 0)
 199                dup2(s2, 2), close(s2);
 200#endif
 201
 202        if (cmd->pid < 0) {
 203                if (need_in)
 204                        close_pair(fdin);
 205                else if (cmd->in)
 206                        close(cmd->in);
 207                if (need_out)
 208                        close_pair(fdout);
 209                else if (cmd->out)
 210                        close(cmd->out);
 211                if (need_err)
 212                        close_pair(fderr);
 213                errno = failed_errno;
 214                return -1;
 215        }
 216
 217        if (need_in)
 218                close(fdin[0]);
 219        else if (cmd->in)
 220                close(cmd->in);
 221
 222        if (need_out)
 223                close(fdout[1]);
 224        else if (cmd->out)
 225                close(cmd->out);
 226
 227        if (need_err)
 228                close(fderr[1]);
 229
 230        return 0;
 231}
 232
 233static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 234{
 235        int status, code = -1;
 236        pid_t waiting;
 237        int failed_errno = 0;
 238
 239        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 240                ;       /* nothing */
 241
 242        if (waiting < 0) {
 243                failed_errno = errno;
 244                error("waitpid for %s failed: %s", argv0, strerror(errno));
 245        } else if (waiting != pid) {
 246                error("waitpid is confused (%s)", argv0);
 247        } else if (WIFSIGNALED(status)) {
 248                code = WTERMSIG(status);
 249                error("%s died of signal %d", argv0, code);
 250                /*
 251                 * This return value is chosen so that code & 0xff
 252                 * mimics the exit code that a POSIX shell would report for
 253                 * a program that died from this signal.
 254                 */
 255                code -= 128;
 256        } else if (WIFEXITED(status)) {
 257                code = WEXITSTATUS(status);
 258                /*
 259                 * Convert special exit code when execvp failed.
 260                 */
 261                if (code == 127) {
 262                        code = -1;
 263                        failed_errno = ENOENT;
 264                        if (!silent_exec_failure)
 265                                error("cannot run %s: %s", argv0,
 266                                        strerror(ENOENT));
 267                }
 268        } else {
 269                error("waitpid is confused (%s)", argv0);
 270        }
 271        errno = failed_errno;
 272        return code;
 273}
 274
 275int finish_command(struct child_process *cmd)
 276{
 277        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 278}
 279
 280int run_command(struct child_process *cmd)
 281{
 282        int code = start_command(cmd);
 283        if (code)
 284                return code;
 285        return finish_command(cmd);
 286}
 287
 288static void prepare_run_command_v_opt(struct child_process *cmd,
 289                                      const char **argv,
 290                                      int opt)
 291{
 292        memset(cmd, 0, sizeof(*cmd));
 293        cmd->argv = argv;
 294        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 295        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 296        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 297        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 298}
 299
 300int run_command_v_opt(const char **argv, int opt)
 301{
 302        struct child_process cmd;
 303        prepare_run_command_v_opt(&cmd, argv, opt);
 304        return run_command(&cmd);
 305}
 306
 307int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 308{
 309        struct child_process cmd;
 310        prepare_run_command_v_opt(&cmd, argv, opt);
 311        cmd.dir = dir;
 312        cmd.env = env;
 313        return run_command(&cmd);
 314}
 315
 316#ifdef __MINGW32__
 317static __stdcall unsigned run_thread(void *data)
 318{
 319        struct async *async = data;
 320        return async->proc(async->fd_for_proc, async->data);
 321}
 322#endif
 323
 324int start_async(struct async *async)
 325{
 326        int pipe_out[2];
 327
 328        if (pipe(pipe_out) < 0)
 329                return error("cannot create pipe: %s", strerror(errno));
 330        async->out = pipe_out[0];
 331
 332#ifndef __MINGW32__
 333        /* Flush stdio before fork() to avoid cloning buffers */
 334        fflush(NULL);
 335
 336        async->pid = fork();
 337        if (async->pid < 0) {
 338                error("fork (async) failed: %s", strerror(errno));
 339                close_pair(pipe_out);
 340                return -1;
 341        }
 342        if (!async->pid) {
 343                close(pipe_out[0]);
 344                exit(!!async->proc(pipe_out[1], async->data));
 345        }
 346        close(pipe_out[1]);
 347#else
 348        async->fd_for_proc = pipe_out[1];
 349        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 350        if (!async->tid) {
 351                error("cannot create thread: %s", strerror(errno));
 352                close_pair(pipe_out);
 353                return -1;
 354        }
 355#endif
 356        return 0;
 357}
 358
 359int finish_async(struct async *async)
 360{
 361#ifndef __MINGW32__
 362        int ret = wait_or_whine(async->pid, "child process", 0);
 363#else
 364        DWORD ret = 0;
 365        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 366                ret = error("waiting for thread failed: %lu", GetLastError());
 367        else if (!GetExitCodeThread(async->tid, &ret))
 368                ret = error("cannot get thread exit code: %lu", GetLastError());
 369        CloseHandle(async->tid);
 370#endif
 371        return ret;
 372}
 373
 374int run_hook(const char *index_file, const char *name, ...)
 375{
 376        struct child_process hook;
 377        const char **argv = NULL, *env[2];
 378        char index[PATH_MAX];
 379        va_list args;
 380        int ret;
 381        size_t i = 0, alloc = 0;
 382
 383        if (access(git_path("hooks/%s", name), X_OK) < 0)
 384                return 0;
 385
 386        va_start(args, name);
 387        ALLOC_GROW(argv, i + 1, alloc);
 388        argv[i++] = git_path("hooks/%s", name);
 389        while (argv[i-1]) {
 390                ALLOC_GROW(argv, i + 1, alloc);
 391                argv[i++] = va_arg(args, const char *);
 392        }
 393        va_end(args);
 394
 395        memset(&hook, 0, sizeof(hook));
 396        hook.argv = argv;
 397        hook.no_stdin = 1;
 398        hook.stdout_to_stderr = 1;
 399        if (index_file) {
 400                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 401                env[0] = index;
 402                env[1] = NULL;
 403                hook.env = env;
 404        }
 405
 406        ret = run_command(&hook);
 407        free(argv);
 408        return ret;
 409}