run-command.c

   1 #include "cache.h"
   2 #include "run-command.h"
   3 #include "exec_cmd.h"
   4
   5 static inline void close_pair(int fd[2])
   6 {
   7         close(fd[0]);
   8         close(fd[1]);
   9 }
  10
  11 #ifndef WIN32
  12 static 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
  20 int start_command(struct child_process *cmd)
  21 {
  22         int need_in, need_out, need_err;
  23         int fdin[2], fdout[2], fderr[2];
  24         int failed_errno = failed_errno;
  25
  26         /*
  27          * In case of errors we must keep the promise to close FDs
  28          * that have been passed in via ->in and ->out.
  29          */
  30
  31         need_in = !cmd->no_stdin && cmd->in < 0;
  32         if (need_in) {
  33                 if (pipe(fdin) < 0) {
  34                         failed_errno = errno;
  35                         if (cmd->out > 0)
  36                                 close(cmd->out);
  37                         goto fail_pipe;
  38                 }
  39                 cmd->in = fdin[1];
  40         }
  41
  42         need_out = !cmd->no_stdout
  43                 && !cmd->stdout_to_stderr
  44                 && cmd->out < 0;
  45         if (need_out) {
  46                 if (pipe(fdout) < 0) {
  47                         failed_errno = errno;
  48                         if (need_in)
  49                                 close_pair(fdin);
  50                         else if (cmd->in)
  51                                 close(cmd->in);
  52                         goto fail_pipe;
  53                 }
  54                 cmd->out = fdout[0];
  55         }
  56
  57         need_err = !cmd->no_stderr && cmd->err < 0;
  58         if (need_err) {
  59                 if (pipe(fderr) < 0) {
  60                         failed_errno = errno;
  61                         if (need_in)
  62                                 close_pair(fdin);
  63                         else if (cmd->in)
  64                                 close(cmd->in);
  65                         if (need_out)
  66                                 close_pair(fdout);
  67                         else if (cmd->out)
  68                                 close(cmd->out);
  69 fail_pipe:
  70                         error("cannot create pipe for %s: %s",
  71                                 cmd->argv[0], strerror(failed_errno));
  72                         errno = failed_errno;
  73                         return -1;
  74                 }
  75                 cmd->err = fderr[0];
  76         }
  77
  78         trace_argv_printf(cmd->argv, "trace: run_command:");
  79
  80 #ifndef WIN32
  81         fflush(NULL);
  82         cmd->pid = fork();
  83         if (!cmd->pid) {
  84                 if (cmd->no_stdin)
  85                         dup_devnull(0);
  86                 else if (need_in) {
  87                         dup2(fdin[0], 0);
  88                         close_pair(fdin);
  89                 } else if (cmd->in) {
  90                         dup2(cmd->in, 0);
  91                         close(cmd->in);
  92                 }
  93
  94                 if (cmd->no_stderr)
  95                         dup_devnull(2);
  96                 else if (need_err) {
  97                         dup2(fderr[1], 2);
  98                         close_pair(fderr);
  99                 }
 100
 101                 if (cmd->no_stdout)
 102                         dup_devnull(1);
 103                 else if (cmd->stdout_to_stderr)
 104                         dup2(2, 1);
 105                 else if (need_out) {
 106                         dup2(fdout[1], 1);
 107                         close_pair(fdout);
 108                 } else if (cmd->out > 1) {
 109                         dup2(cmd->out, 1);
 110                         close(cmd->out);
 111                 }
 112
 113                 if (cmd->dir && chdir(cmd->dir))
 114                         die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
 115                             cmd->dir);
 116                 if (cmd->env) {
 117                         for (; *cmd->env; cmd->env++) {
 118                                 if (strchr(*cmd->env, '='))
 119                                         putenv((char *)*cmd->env);
 120                                 else
 121                                         unsetenv(*cmd->env);
 122                         }
 123                 }
 124                 if (cmd->preexec_cb)
 125                         cmd->preexec_cb();
 126                 if (cmd->git_cmd) {
 127                         execv_git_cmd(cmd->argv);
 128                 } else {
 129                         execvp(cmd->argv[0], (char *const*) cmd->argv);
 130                 }
 131                 trace_printf("trace: exec '%s' failed: %s\n", cmd->argv[0],
 132                                 strerror(errno));
 133                 exit(127);
 134         }
 135         if (cmd->pid < 0)
 136                 error("cannot fork() for %s: %s", cmd->argv[0],
 137                         strerror(failed_errno = errno));
 138 #else
 139 {
 140         int fhin = 0, fhout = 1, fherr = 2;
 141         const char **sargv = cmd->argv;
 142         char **env = environ;
 143
 144         if (cmd->no_stdin)
 145                 fhin = open("/dev/null", O_RDWR);
 146         else if (need_in)
 147                 fhin = dup(fdin[0]);
 148         else if (cmd->in)
 149                 fhin = dup(cmd->in);
 150
 151         if (cmd->no_stderr)
 152                 fherr = open("/dev/null", O_RDWR);
 153         else if (need_err)
 154                 fherr = dup(fderr[1]);
 155
 156         if (cmd->no_stdout)
 157                 fhout = open("/dev/null", O_RDWR);
 158         else if (cmd->stdout_to_stderr)
 159                 fhout = dup(fherr);
 160         else if (need_out)
 161                 fhout = dup(fdout[1]);
 162         else if (cmd->out > 1)
 163                 fhout = dup(cmd->out);
 164
 165         if (cmd->dir)
 166                 die("chdir in start_command() not implemented");
 167         if (cmd->env)
 168                 env = make_augmented_environ(cmd->env);
 169
 170         if (cmd->git_cmd) {
 171                 cmd->argv = prepare_git_cmd(cmd->argv);
 172         }
 173
 174         cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
 175                                   fhin, fhout, fherr);
 176         failed_errno = errno;
 177         if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
 178                 error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
 179
 180         if (cmd->env)
 181                 free_environ(env);
 182         if (cmd->git_cmd)
 183                 free(cmd->argv);
 184
 185         cmd->argv = sargv;
 186         if (fhin != 0)
 187                 close(fhin);
 188         if (fhout != 1)
 189                 close(fhout);
 190         if (fherr != 2)
 191                 close(fherr);
 192 }
 193 #endif
 194
 195         if (cmd->pid < 0) {
 196                 if (need_in)
 197                         close_pair(fdin);
 198                 else if (cmd->in)
 199                         close(cmd->in);
 200                 if (need_out)
 201                         close_pair(fdout);
 202                 else if (cmd->out)
 203                         close(cmd->out);
 204                 if (need_err)
 205                         close_pair(fderr);
 206                 errno = failed_errno;
 207                 return -1;
 208         }
 209
 210         if (need_in)
 211                 close(fdin[0]);
 212         else if (cmd->in)
 213                 close(cmd->in);
 214
 215         if (need_out)
 216                 close(fdout[1]);
 217         else if (cmd->out)
 218                 close(cmd->out);
 219
 220         if (need_err)
 221                 close(fderr[1]);
 222
 223         return 0;
 224 }
 225
 226 static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
 227 {
 228         int status, code = -1;
 229         pid_t waiting;
 230         int failed_errno = 0;
 231
 232         while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
 233                 ;       /* nothing */
 234
 235         if (waiting < 0) {
 236                 failed_errno = errno;
 237                 error("waitpid for %s failed: %s", argv0, strerror(errno));
 238         } else if (waiting != pid) {
 239                 error("waitpid is confused (%s)", argv0);
 240         } else if (WIFSIGNALED(status)) {
 241                 code = WTERMSIG(status);
 242                 error("%s died of signal %d", argv0, code);
 243                 /*
 244                  * This return value is chosen so that code & 0xff
 245                  * mimics the exit code that a POSIX shell would report for
 246                  * a program that died from this signal.
 247                  */
 248                 code -= 128;
 249         } else if (WIFEXITED(status)) {
 250                 code = WEXITSTATUS(status);
 251                 /*
 252                  * Convert special exit code when execvp failed.
 253                  */
 254                 if (code == 127) {
 255                         code = -1;
 256                         failed_errno = ENOENT;
 257                         if (!silent_exec_failure)
 258                                 error("cannot run %s: %s", argv0,
 259                                         strerror(ENOENT));
 260                 }
 261         } else {
 262                 error("waitpid is confused (%s)", argv0);
 263         }
 264         errno = failed_errno;
 265         return code;
 266 }
 267
 268 int finish_command(struct child_process *cmd)
 269 {
 270         return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
 271 }
 272
 273 int run_command(struct child_process *cmd)
 274 {
 275         int code = start_command(cmd);
 276         if (code)
 277                 return code;
 278         return finish_command(cmd);
 279 }
 280
 281 static void prepare_run_command_v_opt(struct child_process *cmd,
 282                                       const char **argv,
 283                                       int opt)
 284 {
 285         memset(cmd, 0, sizeof(*cmd));
 286         cmd->argv = argv;
 287         cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 288         cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 289         cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 290         cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
 291 }
 292
 293 int run_command_v_opt(const char **argv, int opt)
 294 {
 295         struct child_process cmd;
 296         prepare_run_command_v_opt(&cmd, argv, opt);
 297         return run_command(&cmd);
 298 }
 299
 300 int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 301 {
 302         struct child_process cmd;
 303         prepare_run_command_v_opt(&cmd, argv, opt);
 304         cmd.dir = dir;
 305         cmd.env = env;
 306         return run_command(&cmd);
 307 }
 308
 309 #ifdef WIN32
 310 static unsigned __stdcall run_thread(void *data)
 311 {
 312         struct async *async = data;
 313         return async->proc(async->fd_for_proc, async->data);
 314 }
 315 #endif
 316
 317 int start_async(struct async *async)
 318 {
 319         int pipe_out[2];
 320
 321         if (pipe(pipe_out) < 0)
 322                 return error("cannot create pipe: %s", strerror(errno));
 323         async->out = pipe_out[0];
 324
 325 #ifndef WIN32
 326         /* Flush stdio before fork() to avoid cloning buffers */
 327         fflush(NULL);
 328
 329         async->pid = fork();
 330         if (async->pid < 0) {
 331                 error("fork (async) failed: %s", strerror(errno));
 332                 close_pair(pipe_out);
 333                 return -1;
 334         }
 335         if (!async->pid) {
 336                 close(pipe_out[0]);
 337                 exit(!!async->proc(pipe_out[1], async->data));
 338         }
 339         close(pipe_out[1]);
 340 #else
 341         async->fd_for_proc = pipe_out[1];
 342         async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 343         if (!async->tid) {
 344                 error("cannot create thread: %s", strerror(errno));
 345                 close_pair(pipe_out);
 346                 return -1;
 347         }
 348 #endif
 349         return 0;
 350 }
 351
 352 int finish_async(struct async *async)
 353 {
 354 #ifndef WIN32
 355         int ret = wait_or_whine(async->pid, "child process", 0);
 356 #else
 357         DWORD ret = 0;
 358         if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 359                 ret = error("waiting for thread failed: %lu", GetLastError());
 360         else if (!GetExitCodeThread(async->tid, &ret))
 361                 ret = error("cannot get thread exit code: %lu", GetLastError());
 362         CloseHandle(async->tid);
 363 #endif
 364         return ret;
 365 }
 366
 367 int run_hook(const char *index_file, const char *name, ...)
 368 {
 369         struct child_process hook;
 370         const char **argv = NULL, *env[2];
 371         char index[PATH_MAX];
 372         va_list args;
 373         int ret;
 374         size_t i = 0, alloc = 0;
 375
 376         if (access(git_path("hooks/%s", name), X_OK) < 0)
 377                 return 0;
 378
 379         va_start(args, name);
 380         ALLOC_GROW(argv, i + 1, alloc);
 381         argv[i++] = git_path("hooks/%s", name);
 382         while (argv[i-1]) {
 383                 ALLOC_GROW(argv, i + 1, alloc);
 384                 argv[i++] = va_arg(args, const char *);
 385         }
 386         va_end(args);
 387
 388         memset(&hook, 0, sizeof(hook));
 389         hook.argv = argv;
 390         hook.no_stdin = 1;
 391         hook.stdout_to_stderr = 1;
 392         if (index_file) {
 393                 snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 394                 env[0] = index;
 395                 env[1] = NULL;
 396                 hook.env = env;
 397         }
 398
 399         ret = run_command(&hook);
 400         free(argv);
 401         return ret;
 402 }