Andrew's git - gitweb.git/blob

cf2d8f7fae1356e50736cb9d599625df79738a2a
   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                }
  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{
 138        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 139        const char **sargv = cmd->argv;
 140        char **env = environ;
 141
 142        if (cmd->no_stdin) {
 143                s0 = dup(0);
 144                dup_devnull(0);
 145        } else if (need_in) {
 146                s0 = dup(0);
 147                dup2(fdin[0], 0);
 148        } else if (cmd->in) {
 149                s0 = dup(0);
 150                dup2(cmd->in, 0);
 151        }
 152
 153        if (cmd->no_stderr) {
 154                s2 = dup(2);
 155                dup_devnull(2);
 156        } else if (need_err) {
 157                s2 = dup(2);
 158                dup2(fderr[1], 2);
 159        }
 160
 161        if (cmd->no_stdout) {
 162                s1 = dup(1);
 163                dup_devnull(1);
 164        } else if (cmd->stdout_to_stderr) {
 165                s1 = dup(1);
 166                dup2(2, 1);
 167        } else if (need_out) {
 168                s1 = dup(1);
 169                dup2(fdout[1], 1);
 170        } else if (cmd->out > 1) {
 171                s1 = dup(1);
 172                dup2(cmd->out, 1);
 173        }
 174
 175        if (cmd->dir)
 176                die("chdir in start_command() not implemented");
 177        if (cmd->env)
 178                env = make_augmented_environ(cmd->env);
 179
 180        if (cmd->git_cmd) {
 181                cmd->argv = prepare_git_cmd(cmd->argv);
 182        }
 183
 184        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 185        failed_errno = errno;
 186        if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 187                error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 188
 189        if (cmd->env)
 190                free_environ(env);
 191        if (cmd->git_cmd)
 192                free(cmd->argv);
 193
 194        cmd->argv = sargv;
 195        if (s0 >= 0)
 196                dup2(s0, 0), close(s0);
 197        if (s1 >= 0)
 198                dup2(s1, 1), close(s1);
 199        if (s2 >= 0)
 200                dup2(s2, 2), close(s2);
 201}
 202#endif
 203
 204        if (cmd->pid < 0) {
 205                if (need_in)
 206                        close_pair(fdin);
 207                else if (cmd->in)
 208                        close(cmd->in);
 209                if (need_out)
 210                        close_pair(fdout);
 211                else if (cmd->out)
 212                        close(cmd->out);
 213                if (need_err)
 214                        close_pair(fderr);
 215                errno = failed_errno;
 216                return -1;
 217        }
 218
 219        if (need_in)
 220                close(fdin[0]);
 221        else if (cmd->in)
 222                close(cmd->in);
 223
 224        if (need_out)
 225                close(fdout[1]);
 226        else if (cmd->out)
 227                close(cmd->out);
 228
 229        if (need_err)
 230                close(fderr[1]);
 231
 232        return 0;
 233}
 234
 235static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 236{
 237        int status, code = -1;
 238        pid_t waiting;
 239        int failed_errno = 0;
 240
 241        while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 242                ;       /* nothing */
 243
 244        if (waiting < 0) {
 245                failed_errno = errno;
 246                error("waitpid for %s failed: %s", argv0, strerror(errno));
 247        } else if (waiting != pid) {
 248                error("waitpid is confused (%s)", argv0);
 249        } else if (WIFSIGNALED(status)) {
 250                code = WTERMSIG(status);
 251                error("%s died of signal %d", argv0, code);
 252                /*
 253                 * This return value is chosen so that code & 0xff
 254                 * mimics the exit code that a POSIX shell would report for
 255                 * a program that died from this signal.
 256                 */
 257                code -= 128;
 258        } else if (WIFEXITED(status)) {
 259                code = WEXITSTATUS(status);
 260                /*
 261                 * Convert special exit code when execvp failed.
 262                 */
 263                if (code == 127) {
 264                        code = -1;
 265                        failed_errno = ENOENT;
 266                        if (!silent_exec_failure)
 267                                error("cannot run %s: %s", argv0,
 268                                        strerror(ENOENT));
 269                }
 270        } else {
 271                error("waitpid is confused (%s)", argv0);
 272        }
 273        errno = failed_errno;
 274        return code;
 275}
 276
 277int finish_command(struct child_process *cmd)
 278{
 279        return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 280}
 281
 282int run_command(struct child_process *cmd)
 283{
 284        int code = start_command(cmd);
 285        if (code)
 286                return code;
 287        return finish_command(cmd);
 288}
 289
 290static void prepare_run_command_v_opt(struct child_process *cmd,
 291                                      const char **argv,
 292                                      int opt)
 293{
 294        memset(cmd, 0, sizeof(*cmd));
 295        cmd->argv = argv;
 296        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 297        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 298        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 299        cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 300}
 301
 302int run_command_v_opt(const char **argv, int opt)
 303{
 304        struct child_process cmd;
 305        prepare_run_command_v_opt(&cmd, argv, opt);
 306        return run_command(&cmd);
 307}
 308
 309int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 310{
 311        struct child_process cmd;
 312        prepare_run_command_v_opt(&cmd, argv, opt);
 313        cmd.dir = dir;
 314        cmd.env = env;
 315        return run_command(&cmd);
 316}
 317
 318#ifdef WIN32
 319static unsigned __stdcall run_thread(void *data)
 320{
 321        struct async *async = data;
 322        return async->proc(async->fd_for_proc, async->data);
 323}
 324#endif
 325
 326int start_async(struct async *async)
 327{
 328        int pipe_out[2];
 329
 330        if (pipe(pipe_out) < 0)
 331                return error("cannot create pipe: %s", strerror(errno));
 332        async->out = pipe_out[0];
 333
 334#ifndef WIN32
 335        /* Flush stdio before fork() to avoid cloning buffers */
 336        fflush(NULL);
 337
 338        async->pid = fork();
 339        if (async->pid < 0) {
 340                error("fork (async) failed: %s", strerror(errno));
 341                close_pair(pipe_out);
 342                return -1;
 343        }
 344        if (!async->pid) {
 345                close(pipe_out[0]);
 346                exit(!!async->proc(pipe_out[1], async->data));
 347        }
 348        close(pipe_out[1]);
 349#else
 350        async->fd_for_proc = pipe_out[1];
 351        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 352        if (!async->tid) {
 353                error("cannot create thread: %s", strerror(errno));
 354                close_pair(pipe_out);
 355                return -1;
 356        }
 357#endif
 358        return 0;
 359}
 360
 361int finish_async(struct async *async)
 362{
 363#ifndef WIN32
 364        int ret = wait_or_whine(async->pid, "child process", 0);
 365#else
 366        DWORD ret = 0;
 367        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 368                ret = error("waiting for thread failed: %lu", GetLastError());
 369        else if (!GetExitCodeThread(async->tid, &ret))
 370                ret = error("cannot get thread exit code: %lu", GetLastError());
 371        CloseHandle(async->tid);
 372#endif
 373        return ret;
 374}
 375
 376int run_hook(const char *index_file, const char *name, ...)
 377{
 378        struct child_process hook;
 379        const char **argv = NULL, *env[2];
 380        char index[PATH_MAX];
 381        va_list args;
 382        int ret;
 383        size_t i = 0, alloc = 0;
 384
 385        if (access(git_path("hooks/%s", name), X_OK) < 0)
 386                return 0;
 387
 388        va_start(args, name);
 389        ALLOC_GROW(argv, i + 1, alloc);
 390        argv[i++] = git_path("hooks/%s", name);
 391        while (argv[i-1]) {
 392                ALLOC_GROW(argv, i + 1, alloc);
 393                argv[i++] = va_arg(args, const char *);
 394        }
 395        va_end(args);
 396
 397        memset(&hook, 0, sizeof(hook));
 398        hook.argv = argv;
 399        hook.no_stdin = 1;
 400        hook.stdout_to_stderr = 1;
 401        if (index_file) {
 402                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 403                env[0] = index;
 404                env[1] = NULL;
 405                hook.env = env;
 406        }
 407
 408        ret = run_command(&hook);
 409        free(argv);
 410        return ret;
 411}