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 WIN32
  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                } else if (cmd->err > 1) {
  98                        dup2(cmd->err, 2);
  99                        close(cmd->err);
 100                }
 101
 102                if (cmd->no_stdout)
 103                        dup_devnull(1);
 104                else if (cmd->stdout_to_stderr)
 105                        dup2(2, 1);
 106                else if (need_out) {
 107                        dup2(fdout[1], 1);
 108                        close_pair(fdout);
 109                } else if (cmd->out > 1) {
 110                        dup2(cmd->out, 1);
 111                        close(cmd->out);
 112                }
 113
 114                if (cmd->dir && chdir(cmd->dir))
 115                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 116                            cmd->dir);
 117                if (cmd->env) {
 118                        for (; *cmd->env; cmd->env++) {
 119                                if (strchr(*cmd->env, '='))
 120                                        putenv((char *)*cmd->env);
 121                                else
 122                                        unsetenv(*cmd->env);
 123                        }
 124                }
 125                if (cmd->preexec_cb)
 126                        cmd->preexec_cb();
 127                if (cmd->git_cmd) {
 128                        execv_git_cmd(cmd->argv);
 129                } else {
 130                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 131                }
 132                trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
 133                                strerror(errno));
 134                exit(127);
 135        }
 136        if (cmd->pid < 0)
 137                error("cannot fork() for %s: %s", cmd->argv[0],
 138                        strerror(failed_errno = errno));
 139#else
 140{
 141        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 142        const char **sargv = cmd->argv;
 143        char **env = environ;
 144
 145        if (cmd->no_stdin) {
 146                s0 = dup(0);
 147                dup_devnull(0);
 148        } else if (need_in) {
 149                s0 = dup(0);
 150                dup2(fdin[0], 0);
 151        } else if (cmd->in) {
 152                s0 = dup(0);
 153                dup2(cmd->in, 0);
 154        }
 155
 156        if (cmd->no_stderr) {
 157                s2 = dup(2);
 158                dup_devnull(2);
 159        } else if (need_err) {
 160                s2 = dup(2);
 161                dup2(fderr[1], 2);
 162        } else if (cmd->err > 2) {
 163                s2 = dup(2);
 164                dup2(cmd->err, 2);
 165        }
 166
 167        if (cmd->no_stdout) {
 168                s1 = dup(1);
 169                dup_devnull(1);
 170        } else if (cmd->stdout_to_stderr) {
 171                s1 = dup(1);
 172                dup2(2, 1);
 173        } else if (need_out) {
 174                s1 = dup(1);
 175                dup2(fdout[1], 1);
 176        } else if (cmd->out > 1) {
 177                s1 = dup(1);
 178                dup2(cmd->out, 1);
 179        }
 180
 181        if (cmd->dir)
 182                die("chdir in start_command() not implemented");
 183        if (cmd->env)
 184                env = make_augmented_environ(cmd->env);
 185
 186        if (cmd->git_cmd) {
 187                cmd->argv = prepare_git_cmd(cmd->argv);
 188        }
 189
 190        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 191        failed_errno = errno;
 192        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 193                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 194
 195        if (cmd->env)
 196                free_environ(env);
 197        if (cmd->git_cmd)
 198                free(cmd->argv);
 199
 200        cmd->argv = sargv;
 201        if (s0 >= 0)
 202                dup2(s0, 0), close(s0);
 203        if (s1 >= 0)
 204                dup2(s1, 1), close(s1);
 205        if (s2 >= 0)
 206                dup2(s2, 2), close(s2);
 207}
 208#endif
 209
 210        if (cmd->pid < 0) {
 211                if (need_in)
 212                        close_pair(fdin);
 213                else if (cmd->in)
 214                        close(cmd->in);
 215                if (need_out)
 216                        close_pair(fdout);
 217                else if (cmd->out)
 218                        close(cmd->out);
 219                if (need_err)
 220                        close_pair(fderr);
 221                errno = failed_errno;
 222                return -1;
 223        }
 224
 225        if (need_in)
 226                close(fdin[0]);
 227        else if (cmd->in)
 228                close(cmd->in);
 229
 230        if (need_out)
 231                close(fdout[1]);
 232        else if (cmd->out)
 233                close(cmd->out);
 234
 235        if (need_err)
 236                close(fderr[1]);
 237        else if (cmd->err)
 238                close(cmd->err);
 239
 240        return 0;
 241}
 242
 243static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 244{
 245        int status, code = -1;
 246        pid_t waiting;
 247        int failed_errno = 0;
 248
 249        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 250                ;       /* nothing */
 251
 252        if (waiting < 0) {
 253                failed_errno = errno;
 254                error("waitpid for %s failed: %s", argv0, strerror(errno));
 255        } else if (waiting != pid) {
 256                error("waitpid is confused (%s)", argv0);
 257        } else if (WIFSIGNALED(status)) {
 258                code = WTERMSIG(status);
 259                error("%s died of signal %d", argv0, code);
 260                /*
 261                 * This return value is chosen so that code & 0xff
 262                 * mimics the exit code that a POSIX shell would report for
 263                 * a program that died from this signal.
 264                 */
 265                code -= 128;
 266        } else if (WIFEXITED(status)) {
 267                code = WEXITSTATUS(status);
 268                /*
 269                 * Convert special exit code when execvp failed.
 270                 */
 271                if (code == 127) {
 272                        code = -1;
 273                        failed_errno = ENOENT;
 274                        if (!silent_exec_failure)
 275                                error("cannot run %s: %s", argv0,
 276                                        strerror(ENOENT));
 277                }
 278        } else {
 279                error("waitpid is confused (%s)", argv0);
 280        }
 281        errno = failed_errno;
 282        return code;
 283}
 284
 285int finish_command(struct child_process *cmd)
 286{
 287        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 288}
 289
 290int run_command(struct child_process *cmd)
 291{
 292        int code = start_command(cmd);
 293        if (code)
 294                return code;
 295        return finish_command(cmd);
 296}
 297
 298static void prepare_run_command_v_opt(struct child_process *cmd,
 299                                      const char **argv,
 300                                      int opt)
 301{
 302        memset(cmd, 0, sizeof(*cmd));
 303        cmd->argv = argv;
 304        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 305        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 306        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 307        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 308}
 309
 310int run_command_v_opt(const char **argv, int opt)
 311{
 312        struct child_process cmd;
 313        prepare_run_command_v_opt(&cmd, argv, opt);
 314        return run_command(&cmd);
 315}
 316
 317int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 318{
 319        struct child_process cmd;
 320        prepare_run_command_v_opt(&cmd, argv, opt);
 321        cmd.dir = dir;
 322        cmd.env = env;
 323        return run_command(&cmd);
 324}
 325
 326#ifdef WIN32
 327static unsigned __stdcall run_thread(void *data)
 328{
 329        struct async *async = data;
 330        return async->proc(async->fd_for_proc, async->data);
 331}
 332#endif
 333
 334int start_async(struct async *async)
 335{
 336        int pipe_out[2];
 337
 338        if (pipe(pipe_out) < 0)
 339                return error("cannot create pipe: %s", strerror(errno));
 340        async->out = pipe_out[0];
 341
 342#ifndef WIN32
 343        /* Flush stdio before fork() to avoid cloning buffers */
 344        fflush(NULL);
 345
 346        async->pid = fork();
 347        if (async->pid < 0) {
 348                error("fork (async) failed: %s", strerror(errno));
 349                close_pair(pipe_out);
 350                return -1;
 351        }
 352        if (!async->pid) {
 353                close(pipe_out[0]);
 354                exit(!!async->proc(pipe_out[1], async->data));
 355        }
 356        close(pipe_out[1]);
 357#else
 358        async->fd_for_proc = pipe_out[1];
 359        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 360        if (!async->tid) {
 361                error("cannot create thread: %s", strerror(errno));
 362                close_pair(pipe_out);
 363                return -1;
 364        }
 365#endif
 366        return 0;
 367}
 368
 369int finish_async(struct async *async)
 370{
 371#ifndef WIN32
 372        int ret = wait_or_whine(async->pid, "child process", 0);
 373#else
 374        DWORD ret = 0;
 375        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 376                ret = error("waiting for thread failed: %lu", GetLastError());
 377        else if (!GetExitCodeThread(async->tid, &ret))
 378                ret = error("cannot get thread exit code: %lu", GetLastError());
 379        CloseHandle(async->tid);
 380#endif
 381        return ret;
 382}
 383
 384int run_hook(const char *index_file, const char *name, ...)
 385{
 386        struct child_process hook;
 387        const char **argv = NULL, *env[2];
 388        char index[PATH_MAX];
 389        va_list args;
 390        int ret;
 391        size_t i = 0, alloc = 0;
 392
 393        if (access(git_path("hooks/%s", name), X_OK) < 0)
 394                return 0;
 395
 396        va_start(args, name);
 397        ALLOC_GROW(argv, i + 1, alloc);
 398        argv[i++] = git_path("hooks/%s", name);
 399        while (argv[i-1]) {
 400                ALLOC_GROW(argv, i + 1, alloc);
 401                argv[i++] = va_arg(args, const char *);
 402        }
 403        va_end(args);
 404
 405        memset(&hook, 0, sizeof(hook));
 406        hook.argv = argv;
 407        hook.no_stdin = 1;
 408        hook.stdout_to_stderr = 1;
 409        if (index_file) {
 410                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 411                env[0] = index;
 412                env[1] = NULL;
 413                hook.env = env;
 414        }
 415
 416        ret = run_command(&hook);
 417        free(argv);
 418        return ret;
 419}