Andrew's git - gitweb.git/blob

a4e309eeb9b1e92dea7a4c179276a0a45f8064c7
   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
  23        /*
  24         * In case of errors we must keep the promise to close FDs
  25         * that have been passed in via ->in and ->out.
  26         */
  27
  28        need_in = !cmd->no_stdin && cmd->in < 0;
  29        if (need_in) {
  30                if (pipe(fdin) < 0) {
  31                        if (cmd->out > 0)
  32                                close(cmd->out);
  33                        return -ERR_RUN_COMMAND_PIPE;
  34                }
  35                cmd->in = fdin[1];
  36        }
  37
  38        need_out = !cmd->no_stdout
  39                && !cmd->stdout_to_stderr
  40                && cmd->out < 0;
  41        if (need_out) {
  42                if (pipe(fdout) < 0) {
  43                        if (need_in)
  44                                close_pair(fdin);
  45                        else if (cmd->in)
  46                                close(cmd->in);
  47                        return -ERR_RUN_COMMAND_PIPE;
  48                }
  49                cmd->out = fdout[0];
  50        }
  51
  52        need_err = !cmd->no_stderr && cmd->err < 0;
  53        if (need_err) {
  54                if (pipe(fderr) < 0) {
  55                        if (need_in)
  56                                close_pair(fdin);
  57                        else if (cmd->in)
  58                                close(cmd->in);
  59                        if (need_out)
  60                                close_pair(fdout);
  61                        else if (cmd->out)
  62                                close(cmd->out);
  63                        return -ERR_RUN_COMMAND_PIPE;
  64                }
  65                cmd->err = fderr[0];
  66        }
  67
  68        trace_argv_printf(cmd->argv, "trace: run_command:");
  69
  70#ifndef __MINGW32__
  71        fflush(NULL);
  72        cmd->pid = fork();
  73        if (!cmd->pid) {
  74                if (cmd->no_stdin)
  75                        dup_devnull(0);
  76                else if (need_in) {
  77                        dup2(fdin[0], 0);
  78                        close_pair(fdin);
  79                } else if (cmd->in) {
  80                        dup2(cmd->in, 0);
  81                        close(cmd->in);
  82                }
  83
  84                if (cmd->no_stderr)
  85                        dup_devnull(2);
  86                else if (need_err) {
  87                        dup2(fderr[1], 2);
  88                        close_pair(fderr);
  89                }
  90
  91                if (cmd->no_stdout)
  92                        dup_devnull(1);
  93                else if (cmd->stdout_to_stderr)
  94                        dup2(2, 1);
  95                else if (need_out) {
  96                        dup2(fdout[1], 1);
  97                        close_pair(fdout);
  98                } else if (cmd->out > 1) {
  99                        dup2(cmd->out, 1);
 100                        close(cmd->out);
 101                }
 102
 103                if (cmd->dir && chdir(cmd->dir))
 104                        die("exec %s: cd to %s failed (%s)", cmd->argv[0],
 105                            cmd->dir, strerror(errno));
 106                if (cmd->env) {
 107                        for (; *cmd->env; cmd->env++) {
 108                                if (strchr(*cmd->env, '='))
 109                                        putenv((char *)*cmd->env);
 110                                else
 111                                        unsetenv(*cmd->env);
 112                        }
 113                }
 114                if (cmd->preexec_cb)
 115                        cmd->preexec_cb();
 116                if (cmd->git_cmd) {
 117                        execv_git_cmd(cmd->argv);
 118                } else {
 119                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 120                }
 121                trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
 122                                strerror(errno));
 123                exit(127);
 124        }
 125#else
 126        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 127        const char **sargv = cmd->argv;
 128        char **env = environ;
 129
 130        if (cmd->no_stdin) {
 131                s0 = dup(0);
 132                dup_devnull(0);
 133        } else if (need_in) {
 134                s0 = dup(0);
 135                dup2(fdin[0], 0);
 136        } else if (cmd->in) {
 137                s0 = dup(0);
 138                dup2(cmd->in, 0);
 139        }
 140
 141        if (cmd->no_stderr) {
 142                s2 = dup(2);
 143                dup_devnull(2);
 144        } else if (need_err) {
 145                s2 = dup(2);
 146                dup2(fderr[1], 2);
 147        }
 148
 149        if (cmd->no_stdout) {
 150                s1 = dup(1);
 151                dup_devnull(1);
 152        } else if (cmd->stdout_to_stderr) {
 153                s1 = dup(1);
 154                dup2(2, 1);
 155        } else if (need_out) {
 156                s1 = dup(1);
 157                dup2(fdout[1], 1);
 158        } else if (cmd->out > 1) {
 159                s1 = dup(1);
 160                dup2(cmd->out, 1);
 161        }
 162
 163        if (cmd->dir)
 164                die("chdir in start_command() not implemented");
 165        if (cmd->env) {
 166                env = copy_environ();
 167                for (; *cmd->env; cmd->env++)
 168                        env = env_setenv(env, *cmd->env);
 169        }
 170
 171        if (cmd->git_cmd) {
 172                cmd->argv = prepare_git_cmd(cmd->argv);
 173        }
 174
 175        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 176
 177        if (cmd->env)
 178                free_environ(env);
 179        if (cmd->git_cmd)
 180                free(cmd->argv);
 181
 182        cmd->argv = sargv;
 183        if (s0 >= 0)
 184                dup2(s0, 0), close(s0);
 185        if (s1 >= 0)
 186                dup2(s1, 1), close(s1);
 187        if (s2 >= 0)
 188                dup2(s2, 2), close(s2);
 189#endif
 190
 191        if (cmd->pid < 0) {
 192                int err = errno;
 193                if (need_in)
 194                        close_pair(fdin);
 195                else if (cmd->in)
 196                        close(cmd->in);
 197                if (need_out)
 198                        close_pair(fdout);
 199                else if (cmd->out)
 200                        close(cmd->out);
 201                if (need_err)
 202                        close_pair(fderr);
 203                return err == ENOENT ?
 204                        -ERR_RUN_COMMAND_EXEC :
 205                        -ERR_RUN_COMMAND_FORK;
 206        }
 207
 208        if (need_in)
 209                close(fdin[0]);
 210        else if (cmd->in)
 211                close(cmd->in);
 212
 213        if (need_out)
 214                close(fdout[1]);
 215        else if (cmd->out)
 216                close(cmd->out);
 217
 218        if (need_err)
 219                close(fderr[1]);
 220
 221        return 0;
 222}
 223
 224static int wait_or_whine(pid_t pid)
 225{
 226        for (;;) {
 227                int status, code;
 228                pid_t waiting = waitpid(pid, &status, 0);
 229
 230                if (waiting < 0) {
 231                        if (errno == EINTR)
 232                                continue;
 233                        error("waitpid failed (%s)", strerror(errno));
 234                        return -ERR_RUN_COMMAND_WAITPID;
 235                }
 236                if (waiting != pid)
 237                        return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 238                if (WIFSIGNALED(status))
 239                        return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 240
 241                if (!WIFEXITED(status))
 242                        return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 243                code = WEXITSTATUS(status);
 244                return code == 127 ? -ERR_RUN_COMMAND_EXEC : code;
 245        }
 246}
 247
 248int finish_command(struct child_process *cmd)
 249{
 250        return wait_or_whine(cmd->pid);
 251}
 252
 253int run_command(struct child_process *cmd)
 254{
 255        int code = start_command(cmd);
 256        if (code)
 257                return code;
 258        return finish_command(cmd);
 259}
 260
 261static void prepare_run_command_v_opt(struct child_process *cmd,
 262                                      const char **argv,
 263                                      int opt)
 264{
 265        memset(cmd, 0, sizeof(*cmd));
 266        cmd->argv = argv;
 267        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 268        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 269        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 270}
 271
 272int run_command_v_opt(const char **argv, int opt)
 273{
 274        struct child_process cmd;
 275        prepare_run_command_v_opt(&cmd, argv, opt);
 276        return run_command(&cmd);
 277}
 278
 279int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 280{
 281        struct child_process cmd;
 282        prepare_run_command_v_opt(&cmd, argv, opt);
 283        cmd.dir = dir;
 284        cmd.env = env;
 285        return run_command(&cmd);
 286}
 287
 288#ifdef __MINGW32__
 289static __stdcall unsigned run_thread(void *data)
 290{
 291        struct async *async = data;
 292        return async->proc(async->fd_for_proc, async->data);
 293}
 294#endif
 295
 296int start_async(struct async *async)
 297{
 298        int pipe_out[2];
 299
 300        if (pipe(pipe_out) < 0)
 301                return error("cannot create pipe: %s", strerror(errno));
 302        async->out = pipe_out[0];
 303
 304#ifndef __MINGW32__
 305        /* Flush stdio before fork() to avoid cloning buffers */
 306        fflush(NULL);
 307
 308        async->pid = fork();
 309        if (async->pid < 0) {
 310                error("fork (async) failed: %s", strerror(errno));
 311                close_pair(pipe_out);
 312                return -1;
 313        }
 314        if (!async->pid) {
 315                close(pipe_out[0]);
 316                exit(!!async->proc(pipe_out[1], async->data));
 317        }
 318        close(pipe_out[1]);
 319#else
 320        async->fd_for_proc = pipe_out[1];
 321        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 322        if (!async->tid) {
 323                error("cannot create thread: %s", strerror(errno));
 324                close_pair(pipe_out);
 325                return -1;
 326        }
 327#endif
 328        return 0;
 329}
 330
 331int finish_async(struct async *async)
 332{
 333#ifndef __MINGW32__
 334        int ret = 0;
 335
 336        if (wait_or_whine(async->pid))
 337                ret = error("waitpid (async) failed");
 338#else
 339        DWORD ret = 0;
 340        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 341                ret = error("waiting for thread failed: %lu", GetLastError());
 342        else if (!GetExitCodeThread(async->tid, &ret))
 343                ret = error("cannot get thread exit code: %lu", GetLastError());
 344        CloseHandle(async->tid);
 345#endif
 346        return ret;
 347}
 348
 349int run_hook(const char *index_file, const char *name, ...)
 350{
 351        struct child_process hook;
 352        const char **argv = NULL, *env[2];
 353        char index[PATH_MAX];
 354        va_list args;
 355        int ret;
 356        size_t i = 0, alloc = 0;
 357
 358        if (access(git_path("hooks/%s", name), X_OK) < 0)
 359                return 0;
 360
 361        va_start(args, name);
 362        ALLOC_GROW(argv, i + 1, alloc);
 363        argv[i++] = git_path("hooks/%s", name);
 364        while (argv[i-1]) {
 365                ALLOC_GROW(argv, i + 1, alloc);
 366                argv[i++] = va_arg(args, const char *);
 367        }
 368        va_end(args);
 369
 370        memset(&hook, 0, sizeof(hook));
 371        hook.argv = argv;
 372        hook.no_stdin = 1;
 373        hook.stdout_to_stderr = 1;
 374        if (index_file) {
 375                snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 376                env[0] = index;
 377                env[1] = NULL;
 378                hook.env = env;
 379        }
 380
 381        ret = start_command(&hook);
 382        free(argv);
 383        if (ret) {
 384                warning("Could not spawn %s", argv[0]);
 385                return ret;
 386        }
 387        ret = finish_command(&hook);
 388        if (ret == -ERR_RUN_COMMAND_WAITPID_SIGNAL)
 389                warning("%s exited due to uncaught signal", argv[0]);
 390
 391        return ret;
 392}