Andrew's git / gitweb.git / run-command.c
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run-command.con commit git-am: Add am.keepcr and --no-keep-cr to override it (e80d4cb)
   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
  11#ifndef WIN32
  12static inline void dup_devnull(int to)
  13{
  14        int fd = open("/dev/null", O_RDWR);
  15        dup2(fd, to);
  16        close(fd);
  17}
  18#endif
  19
  20static const char **prepare_shell_cmd(const char **argv)
  21{
  22        int argc, nargc = 0;
  23        const char **nargv;
  24
  25        for (argc = 0; argv[argc]; argc++)
  26                ; /* just counting */
  27        /* +1 for NULL, +3 for "sh -c" plus extra $0 */
  28        nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
  29
  30        if (argc < 1)
  31                die("BUG: shell command is empty");
  32
  33        if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
  34                nargv[nargc++] = "sh";
  35                nargv[nargc++] = "-c";
  36
  37                if (argc < 2)
  38                        nargv[nargc++] = argv[0];
  39                else {
  40                        struct strbuf arg0 = STRBUF_INIT;
  41                        strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
  42                        nargv[nargc++] = strbuf_detach(&arg0, NULL);
  43                }
  44        }
  45
  46        for (argc = 0; argv[argc]; argc++)
  47                nargv[nargc++] = argv[argc];
  48        nargv[nargc] = NULL;
  49
  50        return nargv;
  51}
  52
  53#ifndef WIN32
  54static int execv_shell_cmd(const char **argv)
  55{
  56        const char **nargv = prepare_shell_cmd(argv);
  57        trace_argv_printf(nargv, "trace: exec:");
  58        execvp(nargv[0], (char **)nargv);
  59        free(nargv);
  60        return -1;
  61}
  62#endif
  63
  64#ifndef WIN32
  65static int child_err = 2;
  66static int child_notifier = -1;
  67
  68static void notify_parent(void)
  69{
  70        write(child_notifier, "", 1);
  71}
  72
  73static NORETURN void die_child(const char *err, va_list params)
  74{
  75        char msg[4096];
  76        int len = vsnprintf(msg, sizeof(msg), err, params);
  77        if (len > sizeof(msg))
  78                len = sizeof(msg);
  79
  80        write(child_err, "fatal: ", 7);
  81        write(child_err, msg, len);
  82        write(child_err, "\n", 1);
  83        exit(128);
  84}
  85
  86static inline void set_cloexec(int fd)
  87{
  88        int flags = fcntl(fd, F_GETFD);
  89        if (flags >= 0)
  90                fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
  91}
  92#endif
  93
  94static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
  95{
  96        int status, code = -1;
  97        pid_t waiting;
  98        int failed_errno = 0;
  99
 100        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 101                ;       /* nothing */
 102
 103        if (waiting < 0) {
 104                failed_errno = errno;
 105                error("waitpid for %s failed: %s", argv0, strerror(errno));
 106        } else if (waiting != pid) {
 107                error("waitpid is confused (%s)", argv0);
 108        } else if (WIFSIGNALED(status)) {
 109                code = WTERMSIG(status);
 110                error("%s died of signal %d", argv0, code);
 111                /*
 112                 * This return value is chosen so that code & 0xff
 113                 * mimics the exit code that a POSIX shell would report for
 114                 * a program that died from this signal.
 115                 */
 116                code -= 128;
 117        } else if (WIFEXITED(status)) {
 118                code = WEXITSTATUS(status);
 119                /*
 120                 * Convert special exit code when execvp failed.
 121                 */
 122                if (code == 127) {
 123                        code = -1;
 124                        failed_errno = ENOENT;
 125                        if (!silent_exec_failure)
 126                                error("cannot run %s: %s", argv0,
 127                                        strerror(ENOENT));
 128                }
 129        } else {
 130                error("waitpid is confused (%s)", argv0);
 131        }
 132        errno = failed_errno;
 133        return code;
 134}
 135
 136int start_command(struct child_process *cmd)
 137{
 138        int need_in, need_out, need_err;
 139        int fdin[2], fdout[2], fderr[2];
 140        int failed_errno = failed_errno;
 141
 142        /*
 143         * In case of errors we must keep the promise to close FDs
 144         * that have been passed in via ->in and ->out.
 145         */
 146
 147        need_in = !cmd->no_stdin && cmd->in < 0;
 148        if (need_in) {
 149                if (pipe(fdin) < 0) {
 150                        failed_errno = errno;
 151                        if (cmd->out > 0)
 152                                close(cmd->out);
 153                        goto fail_pipe;
 154                }
 155                cmd->in = fdin[1];
 156        }
 157
 158        need_out = !cmd->no_stdout
 159                && !cmd->stdout_to_stderr
 160                && cmd->out < 0;
 161        if (need_out) {
 162                if (pipe(fdout) < 0) {
 163                        failed_errno = errno;
 164                        if (need_in)
 165                                close_pair(fdin);
 166                        else if (cmd->in)
 167                                close(cmd->in);
 168                        goto fail_pipe;
 169                }
 170                cmd->out = fdout[0];
 171        }
 172
 173        need_err = !cmd->no_stderr && cmd->err < 0;
 174        if (need_err) {
 175                if (pipe(fderr) < 0) {
 176                        failed_errno = errno;
 177                        if (need_in)
 178                                close_pair(fdin);
 179                        else if (cmd->in)
 180                                close(cmd->in);
 181                        if (need_out)
 182                                close_pair(fdout);
 183                        else if (cmd->out)
 184                                close(cmd->out);
 185fail_pipe:
 186                        error("cannot create pipe for %s: %s",
 187                                cmd->argv[0], strerror(failed_errno));
 188                        errno = failed_errno;
 189                        return -1;
 190                }
 191                cmd->err = fderr[0];
 192        }
 193
 194        trace_argv_printf(cmd->argv, "trace: run_command:");
 195
 196#ifndef WIN32
 197{
 198        int notify_pipe[2];
 199        if (pipe(notify_pipe))
 200                notify_pipe[0] = notify_pipe[1] = -1;
 201
 202        fflush(NULL);
 203        cmd->pid = fork();
 204        if (!cmd->pid) {
 205                /*
 206                 * Redirect the channel to write syscall error messages to
 207                 * before redirecting the process's stderr so that all die()
 208                 * in subsequent call paths use the parent's stderr.
 209                 */
 210                if (cmd->no_stderr || need_err) {
 211                        child_err = dup(2);
 212                        set_cloexec(child_err);
 213                }
 214                set_die_routine(die_child);
 215
 216                close(notify_pipe[0]);
 217                set_cloexec(notify_pipe[1]);
 218                child_notifier = notify_pipe[1];
 219                atexit(notify_parent);
 220
 221                if (cmd->no_stdin)
 222                        dup_devnull(0);
 223                else if (need_in) {
 224                        dup2(fdin[0], 0);
 225                        close_pair(fdin);
 226                } else if (cmd->in) {
 227                        dup2(cmd->in, 0);
 228                        close(cmd->in);
 229                }
 230
 231                if (cmd->no_stderr)
 232                        dup_devnull(2);
 233                else if (need_err) {
 234                        dup2(fderr[1], 2);
 235                        close_pair(fderr);
 236                } else if (cmd->err > 1) {
 237                        dup2(cmd->err, 2);
 238                        close(cmd->err);
 239                }
 240
 241                if (cmd->no_stdout)
 242                        dup_devnull(1);
 243                else if (cmd->stdout_to_stderr)
 244                        dup2(2, 1);
 245                else if (need_out) {
 246                        dup2(fdout[1], 1);
 247                        close_pair(fdout);
 248                } else if (cmd->out > 1) {
 249                        dup2(cmd->out, 1);
 250                        close(cmd->out);
 251                }
 252
 253                if (cmd->dir && chdir(cmd->dir))
 254                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 255                            cmd->dir);
 256                if (cmd->env) {
 257                        for (; *cmd->env; cmd->env++) {
 258                                if (strchr(*cmd->env, '='))
 259                                        putenv((char *)*cmd->env);
 260                                else
 261                                        unsetenv(*cmd->env);
 262                        }
 263                }
 264                if (cmd->preexec_cb) {
 265                        /*
 266                         * We cannot predict what the pre-exec callback does.
 267                         * Forgo parent notification.
 268                         */
 269                        close(child_notifier);
 270                        child_notifier = -1;
 271
 272                        cmd->preexec_cb();
 273                }
 274                if (cmd->git_cmd) {
 275                        execv_git_cmd(cmd->argv);
 276                } else if (cmd->use_shell) {
 277                        execv_shell_cmd(cmd->argv);
 278                } else {
 279                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 280                }
 281                /*
 282                 * Do not check for cmd->silent_exec_failure; the parent
 283                 * process will check it when it sees this exit code.
 284                 */
 285                if (errno == ENOENT)
 286                        exit(127);
 287                else
 288                        die_errno("cannot exec '%s'", cmd->argv[0]);
 289        }
 290        if (cmd->pid < 0)
 291                error("cannot fork() for %s: %s", cmd->argv[0],
 292                        strerror(failed_errno = errno));
 293
 294        /*
 295         * Wait for child's execvp. If the execvp succeeds (or if fork()
 296         * failed), EOF is seen immediately by the parent. Otherwise, the
 297         * child process sends a single byte.
 298         * Note that use of this infrastructure is completely advisory,
 299         * therefore, we keep error checks minimal.
 300         */
 301        close(notify_pipe[1]);
 302        if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
 303                /*
 304                 * At this point we know that fork() succeeded, but execvp()
 305                 * failed. Errors have been reported to our stderr.
 306                 */
 307                wait_or_whine(cmd->pid, cmd->argv[0],
 308                              cmd->silent_exec_failure);
 309                failed_errno = errno;
 310                cmd->pid = -1;
 311        }
 312        close(notify_pipe[0]);
 313}
 314#else
 315{
 316        int fhin = 0, fhout = 1, fherr = 2;
 317        const char **sargv = cmd->argv;
 318        char **env = environ;
 319
 320        if (cmd->no_stdin)
 321                fhin = open("/dev/null", O_RDWR);
 322        else if (need_in)
 323                fhin = dup(fdin[0]);
 324        else if (cmd->in)
 325                fhin = dup(cmd->in);
 326
 327        if (cmd->no_stderr)
 328                fherr = open("/dev/null", O_RDWR);
 329        else if (need_err)
 330                fherr = dup(fderr[1]);
 331        else if (cmd->err > 2)
 332                fherr = dup(cmd->err);
 333
 334        if (cmd->no_stdout)
 335                fhout = open("/dev/null", O_RDWR);
 336        else if (cmd->stdout_to_stderr)
 337                fhout = dup(fherr);
 338        else if (need_out)
 339                fhout = dup(fdout[1]);
 340        else if (cmd->out > 1)
 341                fhout = dup(cmd->out);
 342
 343        if (cmd->dir)
 344                die("chdir in start_command() not implemented");
 345        if (cmd->env)
 346                env = make_augmented_environ(cmd->env);
 347
 348        if (cmd->git_cmd) {
 349                cmd->argv = prepare_git_cmd(cmd->argv);
 350        } else if (cmd->use_shell) {
 351                cmd->argv = prepare_shell_cmd(cmd->argv);
 352        }
 353
 354        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
 355                                  fhin, fhout, fherr);
 356        failed_errno = errno;
 357        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 358                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 359
 360        if (cmd->env)
 361                free_environ(env);
 362        if (cmd->git_cmd)
 363                free(cmd->argv);
 364
 365        cmd->argv = sargv;
 366        if (fhin != 0)
 367                close(fhin);
 368        if (fhout != 1)
 369                close(fhout);
 370        if (fherr != 2)
 371                close(fherr);
 372}
 373#endif
 374
 375        if (cmd->pid < 0) {
 376                if (need_in)
 377                        close_pair(fdin);
 378                else if (cmd->in)
 379                        close(cmd->in);
 380                if (need_out)
 381                        close_pair(fdout);
 382                else if (cmd->out)
 383                        close(cmd->out);
 384                if (need_err)
 385                        close_pair(fderr);
 386                errno = failed_errno;
 387                return -1;
 388        }
 389
 390        if (need_in)
 391                close(fdin[0]);
 392        else if (cmd->in)
 393                close(cmd->in);
 394
 395        if (need_out)
 396                close(fdout[1]);
 397        else if (cmd->out)
 398                close(cmd->out);
 399
 400        if (need_err)
 401                close(fderr[1]);
 402        else if (cmd->err)
 403                close(cmd->err);
 404
 405        return 0;
 406}
 407
 408int finish_command(struct child_process *cmd)
 409{
 410        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 411}
 412
 413int run_command(struct child_process *cmd)
 414{
 415        int code = start_command(cmd);
 416        if (code)
 417                return code;
 418        return finish_command(cmd);
 419}
 420
 421static void prepare_run_command_v_opt(struct child_process *cmd,
 422                                      const char **argv,
 423                                      int opt)
 424{
 425        memset(cmd, 0, sizeof(*cmd));
 426        cmd->argv = argv;
 427        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 428        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 429        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 430        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 431        cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 432}
 433
 434int run_command_v_opt(const char **argv, int opt)
 435{
 436        struct child_process cmd;
 437        prepare_run_command_v_opt(&cmd, argv, opt);
 438        return run_command(&cmd);
 439}
 440
 441int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 442{
 443        struct child_process cmd;
 444        prepare_run_command_v_opt(&cmd, argv, opt);
 445        cmd.dir = dir;
 446        cmd.env = env;
 447        return run_command(&cmd);
 448}
 449
 450#ifdef WIN32
 451static unsigned __stdcall run_thread(void *data)
 452{
 453        struct async *async = data;
 454        return async->proc(async->proc_in, async->proc_out, async->data);
 455}
 456#endif
 457
 458int start_async(struct async *async)
 459{
 460        int need_in, need_out;
 461        int fdin[2], fdout[2];
 462        int proc_in, proc_out;
 463
 464        need_in = async->in < 0;
 465        if (need_in) {
 466                if (pipe(fdin) < 0) {
 467                        if (async->out > 0)
 468                                close(async->out);
 469                        return error("cannot create pipe: %s", strerror(errno));
 470                }
 471                async->in = fdin[1];
 472        }
 473
 474        need_out = async->out < 0;
 475        if (need_out) {
 476                if (pipe(fdout) < 0) {
 477                        if (need_in)
 478                                close_pair(fdin);
 479                        else if (async->in)
 480                                close(async->in);
 481                        return error("cannot create pipe: %s", strerror(errno));
 482                }
 483                async->out = fdout[0];
 484        }
 485
 486        if (need_in)
 487                proc_in = fdin[0];
 488        else if (async->in)
 489                proc_in = async->in;
 490        else
 491                proc_in = -1;
 492
 493        if (need_out)
 494                proc_out = fdout[1];
 495        else if (async->out)
 496                proc_out = async->out;
 497        else
 498                proc_out = -1;
 499
 500#ifndef WIN32
 501        /* Flush stdio before fork() to avoid cloning buffers */
 502        fflush(NULL);
 503
 504        async->pid = fork();
 505        if (async->pid < 0) {
 506                error("fork (async) failed: %s", strerror(errno));
 507                goto error;
 508        }
 509        if (!async->pid) {
 510                if (need_in)
 511                        close(fdin[1]);
 512                if (need_out)
 513                        close(fdout[0]);
 514                exit(!!async->proc(proc_in, proc_out, async->data));
 515        }
 516
 517        if (need_in)
 518                close(fdin[0]);
 519        else if (async->in)
 520                close(async->in);
 521
 522        if (need_out)
 523                close(fdout[1]);
 524        else if (async->out)
 525                close(async->out);
 526#else
 527        async->proc_in = proc_in;
 528        async->proc_out = proc_out;
 529        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 530        if (!async->tid) {
 531                error("cannot create thread: %s", strerror(errno));
 532                goto error;
 533        }
 534#endif
 535        return 0;
 536
 537error:
 538        if (need_in)
 539                close_pair(fdin);
 540        else if (async->in)
 541                close(async->in);
 542
 543        if (need_out)
 544                close_pair(fdout);
 545        else if (async->out)
 546                close(async->out);
 547        return -1;
 548}
 549
 550int finish_async(struct async *async)
 551{
 552#ifndef WIN32
 553        int ret = wait_or_whine(async->pid, "child process", 0);
 554#else
 555        DWORD ret = 0;
 556        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 557                ret = error("waiting for thread failed: %lu", GetLastError());
 558        else if (!GetExitCodeThread(async->tid, &ret))
 559                ret = error("cannot get thread exit code: %lu", GetLastError());
 560        CloseHandle(async->tid);
 561#endif
 562        return ret;
 563}
 564
 565int run_hook(const char *index_file, const char *name, ...)
 566{
 567        struct child_process hook;
 568        const char **argv = NULL, *env[2];
 569        char index[PATH_MAX];
 570        va_list args;
 571        int ret;
 572        size_t i = 0, alloc = 0;
 573
 574        if (access(git_path("hooks/%s", name), X_OK) < 0)
 575                return 0;
 576
 577        va_start(args, name);
 578        ALLOC_GROW(argv, i + 1, alloc);
 579        argv[i++] = git_path("hooks/%s", name);
 580        while (argv[i-1]) {
 581                ALLOC_GROW(argv, i + 1, alloc);
 582                argv[i++] = va_arg(args, const char *);
 583        }
 584        va_end(args);
 585
 586        memset(&hook, 0, sizeof(hook));
 587        hook.argv = argv;
 588        hook.no_stdin = 1;
 589        hook.stdout_to_stderr = 1;
 590        if (index_file) {
 591                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 592                env[0] = index;
 593                env[1] = NULL;
 594                hook.env = env;
 595        }
 596
 597        ret = run_command(&hook);
 598        free(argv);
 599        return ret;
 600}