Andrew's git - gitweb.git/blob

b2bdcfda3df9cc9a50453dae33926da7377a7b57
   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
  18static const char **prepare_shell_cmd(const char **argv)
  19{
  20        int argc, nargc = 0;
  21        const char **nargv;
  22
  23        for (argc = 0; argv[argc]; argc++)
  24                ; /* just counting */
  25        /* +1 for NULL, +3 for "sh -c" plus extra $0 */
  26        nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
  27
  28        if (argc < 1)
  29                die("BUG: shell command is empty");
  30
  31        nargv[nargc++] = "sh";
  32        nargv[nargc++] = "-c";
  33
  34        if (argc < 2)
  35                nargv[nargc++] = argv[0];
  36        else {
  37                struct strbuf arg0 = STRBUF_INIT;
  38                strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
  39                nargv[nargc++] = strbuf_detach(&arg0, NULL);
  40        }
  41
  42        for (argc = 0; argv[argc]; argc++)
  43                nargv[nargc++] = argv[argc];
  44        nargv[nargc] = NULL;
  45
  46        return nargv;
  47}
  48
  49#ifndef WIN32
  50static int execv_shell_cmd(const char **argv)
  51{
  52        const char **nargv = prepare_shell_cmd(argv);
  53        trace_argv_printf(nargv, "trace: exec:");
  54        execvp(nargv[0], (char **)nargv);
  55        free(nargv);
  56        return -1;
  57}
  58#endif
  59
  60int start_command(struct child_process *cmd)
  61{
  62        int need_in, need_out, need_err;
  63        int fdin[2], fdout[2], fderr[2];
  64        int failed_errno = failed_errno;
  65
  66        /*
  67         * In case of errors we must keep the promise to close FDs
  68         * that have been passed in via ->in and ->out.
  69         */
  70
  71        need_in = !cmd->no_stdin && cmd->in < 0;
  72        if (need_in) {
  73                if (pipe(fdin) < 0) {
  74                        failed_errno = errno;
  75                        if (cmd->out > 0)
  76                                close(cmd->out);
  77                        goto fail_pipe;
  78                }
  79                cmd->in = fdin[1];
  80        }
  81
  82        need_out = !cmd->no_stdout
  83                && !cmd->stdout_to_stderr
  84                && cmd->out < 0;
  85        if (need_out) {
  86                if (pipe(fdout) < 0) {
  87                        failed_errno = errno;
  88                        if (need_in)
  89                                close_pair(fdin);
  90                        else if (cmd->in)
  91                                close(cmd->in);
  92                        goto fail_pipe;
  93                }
  94                cmd->out = fdout[0];
  95        }
  96
  97        need_err = !cmd->no_stderr && cmd->err < 0;
  98        if (need_err) {
  99                if (pipe(fderr) < 0) {
 100                        failed_errno = errno;
 101                        if (need_in)
 102                                close_pair(fdin);
 103                        else if (cmd->in)
 104                                close(cmd->in);
 105                        if (need_out)
 106                                close_pair(fdout);
 107                        else if (cmd->out)
 108                                close(cmd->out);
 109fail_pipe:
 110                        error("cannot create pipe for %s: %s",
 111                                cmd->argv[0], strerror(failed_errno));
 112                        errno = failed_errno;
 113                        return -1;
 114                }
 115                cmd->err = fderr[0];
 116        }
 117
 118        trace_argv_printf(cmd->argv, "trace: run_command:");
 119
 120#ifndef WIN32
 121        fflush(NULL);
 122        cmd->pid = fork();
 123        if (!cmd->pid) {
 124                if (cmd->no_stdin)
 125                        dup_devnull(0);
 126                else if (need_in) {
 127                        dup2(fdin[0], 0);
 128                        close_pair(fdin);
 129                } else if (cmd->in) {
 130                        dup2(cmd->in, 0);
 131                        close(cmd->in);
 132                }
 133
 134                if (cmd->no_stderr)
 135                        dup_devnull(2);
 136                else if (need_err) {
 137                        dup2(fderr[1], 2);
 138                        close_pair(fderr);
 139                }
 140
 141                if (cmd->no_stdout)
 142                        dup_devnull(1);
 143                else if (cmd->stdout_to_stderr)
 144                        dup2(2, 1);
 145                else if (need_out) {
 146                        dup2(fdout[1], 1);
 147                        close_pair(fdout);
 148                } else if (cmd->out > 1) {
 149                        dup2(cmd->out, 1);
 150                        close(cmd->out);
 151                }
 152
 153                if (cmd->dir && chdir(cmd->dir))
 154                        die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 155                            cmd->dir);
 156                if (cmd->env) {
 157                        for (; *cmd->env; cmd->env++) {
 158                                if (strchr(*cmd->env, '='))
 159                                        putenv((char *)*cmd->env);
 160                                else
 161                                        unsetenv(*cmd->env);
 162                        }
 163                }
 164                if (cmd->preexec_cb)
 165                        cmd->preexec_cb();
 166                if (cmd->git_cmd) {
 167                        execv_git_cmd(cmd->argv);
 168                } else if (cmd->use_shell) {
 169                        execv_shell_cmd(cmd->argv);
 170                } else {
 171                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 172                }
 173                trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
 174                                strerror(errno));
 175                exit(127);
 176        }
 177        if (cmd->pid < 0)
 178                error("cannot fork() for %s: %s", cmd->argv[0],
 179                        strerror(failed_errno = errno));
 180#else
 181{
 182        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 183        const char **sargv = cmd->argv;
 184        char **env = environ;
 185
 186        if (cmd->no_stdin) {
 187                s0 = dup(0);
 188                dup_devnull(0);
 189        } else if (need_in) {
 190                s0 = dup(0);
 191                dup2(fdin[0], 0);
 192        } else if (cmd->in) {
 193                s0 = dup(0);
 194                dup2(cmd->in, 0);
 195        }
 196
 197        if (cmd->no_stderr) {
 198                s2 = dup(2);
 199                dup_devnull(2);
 200        } else if (need_err) {
 201                s2 = dup(2);
 202                dup2(fderr[1], 2);
 203        }
 204
 205        if (cmd->no_stdout) {
 206                s1 = dup(1);
 207                dup_devnull(1);
 208        } else if (cmd->stdout_to_stderr) {
 209                s1 = dup(1);
 210                dup2(2, 1);
 211        } else if (need_out) {
 212                s1 = dup(1);
 213                dup2(fdout[1], 1);
 214        } else if (cmd->out > 1) {
 215                s1 = dup(1);
 216                dup2(cmd->out, 1);
 217        }
 218
 219        if (cmd->dir)
 220                die("chdir in start_command() not implemented");
 221        if (cmd->env)
 222                env = make_augmented_environ(cmd->env);
 223
 224        if (cmd->git_cmd) {
 225                cmd->argv = prepare_git_cmd(cmd->argv);
 226        } else if (cmd->use_shell) {
 227                cmd->argv = prepare_shell_cmd(cmd->argv);
 228        }
 229
 230        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 231        failed_errno = errno;
 232        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 233                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 234
 235        if (cmd->env)
 236                free_environ(env);
 237        if (cmd->git_cmd)
 238                free(cmd->argv);
 239
 240        cmd->argv = sargv;
 241        if (s0 >= 0)
 242                dup2(s0, 0), close(s0);
 243        if (s1 >= 0)
 244                dup2(s1, 1), close(s1);
 245        if (s2 >= 0)
 246                dup2(s2, 2), close(s2);
 247}
 248#endif
 249
 250        if (cmd->pid < 0) {
 251                if (need_in)
 252                        close_pair(fdin);
 253                else if (cmd->in)
 254                        close(cmd->in);
 255                if (need_out)
 256                        close_pair(fdout);
 257                else if (cmd->out)
 258                        close(cmd->out);
 259                if (need_err)
 260                        close_pair(fderr);
 261                errno = failed_errno;
 262                return -1;
 263        }
 264
 265        if (need_in)
 266                close(fdin[0]);
 267        else if (cmd->in)
 268                close(cmd->in);
 269
 270        if (need_out)
 271                close(fdout[1]);
 272        else if (cmd->out)
 273                close(cmd->out);
 274
 275        if (need_err)
 276                close(fderr[1]);
 277
 278        return 0;
 279}
 280
 281static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 282{
 283        int status, code = -1;
 284        pid_t waiting;
 285        int failed_errno = 0;
 286
 287        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 288                ;       /* nothing */
 289
 290        if (waiting < 0) {
 291                failed_errno = errno;
 292                error("waitpid for %s failed: %s", argv0, strerror(errno));
 293        } else if (waiting != pid) {
 294                error("waitpid is confused (%s)", argv0);
 295        } else if (WIFSIGNALED(status)) {
 296                code = WTERMSIG(status);
 297                error("%s died of signal %d", argv0, code);
 298                /*
 299                 * This return value is chosen so that code & 0xff
 300                 * mimics the exit code that a POSIX shell would report for
 301                 * a program that died from this signal.
 302                 */
 303                code -= 128;
 304        } else if (WIFEXITED(status)) {
 305                code = WEXITSTATUS(status);
 306                /*
 307                 * Convert special exit code when execvp failed.
 308                 */
 309                if (code == 127) {
 310                        code = -1;
 311                        failed_errno = ENOENT;
 312                        if (!silent_exec_failure)
 313                                error("cannot run %s: %s", argv0,
 314                                        strerror(ENOENT));
 315                }
 316        } else {
 317                error("waitpid is confused (%s)", argv0);
 318        }
 319        errno = failed_errno;
 320        return code;
 321}
 322
 323int finish_command(struct child_process *cmd)
 324{
 325        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 326}
 327
 328int run_command(struct child_process *cmd)
 329{
 330        int code = start_command(cmd);
 331        if (code)
 332                return code;
 333        return finish_command(cmd);
 334}
 335
 336static void prepare_run_command_v_opt(struct child_process *cmd,
 337                                      const char **argv,
 338                                      int opt)
 339{
 340        memset(cmd, 0, sizeof(*cmd));
 341        cmd->argv = argv;
 342        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 343        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 344        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 345        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 346        cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
 347}
 348
 349int run_command_v_opt(const char **argv, int opt)
 350{
 351        struct child_process cmd;
 352        prepare_run_command_v_opt(&cmd, argv, opt);
 353        return run_command(&cmd);
 354}
 355
 356int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 357{
 358        struct child_process cmd;
 359        prepare_run_command_v_opt(&cmd, argv, opt);
 360        cmd.dir = dir;
 361        cmd.env = env;
 362        return run_command(&cmd);
 363}
 364
 365#ifdef WIN32
 366static unsigned __stdcall run_thread(void *data)
 367{
 368        struct async *async = data;
 369        return async->proc(async->fd_for_proc, async->data);
 370}
 371#endif
 372
 373int start_async(struct async *async)
 374{
 375        int pipe_out[2];
 376
 377        if (pipe(pipe_out) < 0)
 378                return error("cannot create pipe: %s", strerror(errno));
 379        async->out = pipe_out[0];
 380
 381#ifndef WIN32
 382        /* Flush stdio before fork() to avoid cloning buffers */
 383        fflush(NULL);
 384
 385        async->pid = fork();
 386        if (async->pid < 0) {
 387                error("fork (async) failed: %s", strerror(errno));
 388                close_pair(pipe_out);
 389                return -1;
 390        }
 391        if (!async->pid) {
 392                close(pipe_out[0]);
 393                exit(!!async->proc(pipe_out[1], async->data));
 394        }
 395        close(pipe_out[1]);
 396#else
 397        async->fd_for_proc = pipe_out[1];
 398        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 399        if (!async->tid) {
 400                error("cannot create thread: %s", strerror(errno));
 401                close_pair(pipe_out);
 402                return -1;
 403        }
 404#endif
 405        return 0;
 406}
 407
 408int finish_async(struct async *async)
 409{
 410#ifndef WIN32
 411        int ret = wait_or_whine(async->pid, "child process", 0);
 412#else
 413        DWORD ret = 0;
 414        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 415                ret = error("waiting for thread failed: %lu", GetLastError());
 416        else if (!GetExitCodeThread(async->tid, &ret))
 417                ret = error("cannot get thread exit code: %lu", GetLastError());
 418        CloseHandle(async->tid);
 419#endif
 420        return ret;
 421}
 422
 423int run_hook(const char *index_file, const char *name, ...)
 424{
 425        struct child_process hook;
 426        const char **argv = NULL, *env[2];
 427        char index[PATH_MAX];
 428        va_list args;
 429        int ret;
 430        size_t i = 0, alloc = 0;
 431
 432        if (access(git_path("hooks/%s", name), X_OK) < 0)
 433                return 0;
 434
 435        va_start(args, name);
 436        ALLOC_GROW(argv, i + 1, alloc);
 437        argv[i++] = git_path("hooks/%s", name);
 438        while (argv[i-1]) {
 439                ALLOC_GROW(argv, i + 1, alloc);
 440                argv[i++] = va_arg(args, const char *);
 441        }
 442        va_end(args);
 443
 444        memset(&hook, 0, sizeof(hook));
 445        hook.argv = argv;
 446        hook.no_stdin = 1;
 447        hook.stdout_to_stderr = 1;
 448        if (index_file) {
 449                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 450                env[0] = index;
 451                env[1] = NULL;
 452                hook.env = env;
 453        }
 454
 455        ret = run_command(&hook);
 456        free(argv);
 457        return ret;
 458}