Andrew's git - gitweb.git/blob

   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                die("exec %s failed.", cmd->argv[0]);
 122        }
 123#else
 124        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 125        const char **sargv = cmd->argv;
 126        char **env = environ;
 127
 128        if (cmd->no_stdin) {
 129                s0 = dup(0);
 130                dup_devnull(0);
 131        } else if (need_in) {
 132                s0 = dup(0);
 133                dup2(fdin[0], 0);
 134        } else if (cmd->in) {
 135                s0 = dup(0);
 136                dup2(cmd->in, 0);
 137        }
 138
 139        if (cmd->no_stderr) {
 140                s2 = dup(2);
 141                dup_devnull(2);
 142        } else if (need_err) {
 143                s2 = dup(2);
 144                dup2(fderr[1], 2);
 145        }
 146
 147        if (cmd->no_stdout) {
 148                s1 = dup(1);
 149                dup_devnull(1);
 150        } else if (cmd->stdout_to_stderr) {
 151                s1 = dup(1);
 152                dup2(2, 1);
 153        } else if (need_out) {
 154                s1 = dup(1);
 155                dup2(fdout[1], 1);
 156        } else if (cmd->out > 1) {
 157                s1 = dup(1);
 158                dup2(cmd->out, 1);
 159        }
 160
 161        if (cmd->dir)
 162                die("chdir in start_command() not implemented");
 163        if (cmd->env) {
 164                env = copy_environ();
 165                for (; *cmd->env; cmd->env++)
 166                        env = env_setenv(env, *cmd->env);
 167        }
 168
 169        if (cmd->git_cmd) {
 170                cmd->argv = prepare_git_cmd(cmd->argv);
 171        }
 172
 173        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 174
 175        if (cmd->env)
 176                free_environ(env);
 177        if (cmd->git_cmd)
 178                free(cmd->argv);
 179
 180        cmd->argv = sargv;
 181        if (s0 >= 0)
 182                dup2(s0, 0), close(s0);
 183        if (s1 >= 0)
 184                dup2(s1, 1), close(s1);
 185        if (s2 >= 0)
 186                dup2(s2, 2), close(s2);
 187#endif
 188
 189        if (cmd->pid < 0) {
 190                if (need_in)
 191                        close_pair(fdin);
 192                else if (cmd->in)
 193                        close(cmd->in);
 194                if (need_out)
 195                        close_pair(fdout);
 196                else if (cmd->out)
 197                        close(cmd->out);
 198                if (need_err)
 199                        close_pair(fderr);
 200                return -ERR_RUN_COMMAND_FORK;
 201        }
 202
 203        if (need_in)
 204                close(fdin[0]);
 205        else if (cmd->in)
 206                close(cmd->in);
 207
 208        if (need_out)
 209                close(fdout[1]);
 210        else if (cmd->out)
 211                close(cmd->out);
 212
 213        if (need_err)
 214                close(fderr[1]);
 215
 216        return 0;
 217}
 218
 219static int wait_or_whine(pid_t pid)
 220{
 221        for (;;) {
 222                int status, code;
 223                pid_t waiting = waitpid(pid, &status, 0);
 224
 225                if (waiting < 0) {
 226                        if (errno == EINTR)
 227                                continue;
 228                        error("waitpid failed (%s)", strerror(errno));
 229                        return -ERR_RUN_COMMAND_WAITPID;
 230                }
 231                if (waiting != pid)
 232                        return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 233                if (WIFSIGNALED(status))
 234                        return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 235
 236                if (!WIFEXITED(status))
 237                        return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 238                code = WEXITSTATUS(status);
 239                if (code)
 240                        return -code;
 241                return 0;
 242        }
 243}
 244
 245int finish_command(struct child_process *cmd)
 246{
 247        return wait_or_whine(cmd->pid);
 248}
 249
 250int run_command(struct child_process *cmd)
 251{
 252        int code = start_command(cmd);
 253        if (code)
 254                return code;
 255        return finish_command(cmd);
 256}
 257
 258static void prepare_run_command_v_opt(struct child_process *cmd,
 259                                      const char **argv,
 260                                      int opt)
 261{
 262        memset(cmd, 0, sizeof(*cmd));
 263        cmd->argv = argv;
 264        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 265        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 266        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 267}
 268
 269int run_command_v_opt(const char **argv, int opt)
 270{
 271        struct child_process cmd;
 272        prepare_run_command_v_opt(&cmd, argv, opt);
 273        return run_command(&cmd);
 274}
 275
 276int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 277{
 278        struct child_process cmd;
 279        prepare_run_command_v_opt(&cmd, argv, opt);
 280        cmd.dir = dir;
 281        cmd.env = env;
 282        return run_command(&cmd);
 283}
 284
 285#ifdef __MINGW32__
 286static __stdcall unsigned run_thread(void *data)
 287{
 288        struct async *async = data;
 289        return async->proc(async->fd_for_proc, async->data);
 290}
 291#endif
 292
 293int start_async(struct async *async)
 294{
 295        int pipe_out[2];
 296
 297        if (pipe(pipe_out) < 0)
 298                return error("cannot create pipe: %s", strerror(errno));
 299        async->out = pipe_out[0];
 300
 301#ifndef __MINGW32__
 302        /* Flush stdio before fork() to avoid cloning buffers */
 303        fflush(NULL);
 304
 305        async->pid = fork();
 306        if (async->pid < 0) {
 307                error("fork (async) failed: %s", strerror(errno));
 308                close_pair(pipe_out);
 309                return -1;
 310        }
 311        if (!async->pid) {
 312                close(pipe_out[0]);
 313                exit(!!async->proc(pipe_out[1], async->data));
 314        }
 315        close(pipe_out[1]);
 316#else
 317        async->fd_for_proc = pipe_out[1];
 318        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 319        if (!async->tid) {
 320                error("cannot create thread: %s", strerror(errno));
 321                close_pair(pipe_out);
 322                return -1;
 323        }
 324#endif
 325        return 0;
 326}
 327
 328int finish_async(struct async *async)
 329{
 330#ifndef __MINGW32__
 331        int ret = 0;
 332
 333        if (wait_or_whine(async->pid))
 334                ret = error("waitpid (async) failed");
 335#else
 336        DWORD ret = 0;
 337        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 338                ret = error("waiting for thread failed: %lu", GetLastError());
 339        else if (!GetExitCodeThread(async->tid, &ret))
 340                ret = error("cannot get thread exit code: %lu", GetLastError());
 341        CloseHandle(async->tid);
 342#endif
 343        return ret;
 344}