Andrew's git / gitweb.git / run-command.c
?
run-command.con commit git checkout: don't warn about unborn branch if -f is already passed (1510dbe)
   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->git_cmd) {
 115                        execv_git_cmd(cmd->argv);
 116                } else {
 117                        execvp(cmd->argv[0], (char *const*) cmd->argv);
 118                }
 119                die("exec %s failed.", cmd->argv[0]);
 120        }
 121#else
 122        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
 123        const char **sargv = cmd->argv;
 124        char **env = environ;
 125
 126        if (cmd->no_stdin) {
 127                s0 = dup(0);
 128                dup_devnull(0);
 129        } else if (need_in) {
 130                s0 = dup(0);
 131                dup2(fdin[0], 0);
 132        } else if (cmd->in) {
 133                s0 = dup(0);
 134                dup2(cmd->in, 0);
 135        }
 136
 137        if (cmd->no_stderr) {
 138                s2 = dup(2);
 139                dup_devnull(2);
 140        } else if (need_err) {
 141                s2 = dup(2);
 142                dup2(fderr[1], 2);
 143        }
 144
 145        if (cmd->no_stdout) {
 146                s1 = dup(1);
 147                dup_devnull(1);
 148        } else if (cmd->stdout_to_stderr) {
 149                s1 = dup(1);
 150                dup2(2, 1);
 151        } else if (need_out) {
 152                s1 = dup(1);
 153                dup2(fdout[1], 1);
 154        } else if (cmd->out > 1) {
 155                s1 = dup(1);
 156                dup2(cmd->out, 1);
 157        }
 158
 159        if (cmd->dir)
 160                die("chdir in start_command() not implemented");
 161        if (cmd->env) {
 162                env = copy_environ();
 163                for (; *cmd->env; cmd->env++)
 164                        env = env_setenv(env, *cmd->env);
 165        }
 166
 167        if (cmd->git_cmd) {
 168                cmd->argv = prepare_git_cmd(cmd->argv);
 169        }
 170
 171        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
 172
 173        if (cmd->env)
 174                free_environ(env);
 175        if (cmd->git_cmd)
 176                free(cmd->argv);
 177
 178        cmd->argv = sargv;
 179        if (s0 >= 0)
 180                dup2(s0, 0), close(s0);
 181        if (s1 >= 0)
 182                dup2(s1, 1), close(s1);
 183        if (s2 >= 0)
 184                dup2(s2, 2), close(s2);
 185#endif
 186
 187        if (cmd->pid < 0) {
 188                if (need_in)
 189                        close_pair(fdin);
 190                else if (cmd->in)
 191                        close(cmd->in);
 192                if (need_out)
 193                        close_pair(fdout);
 194                else if (cmd->out)
 195                        close(cmd->out);
 196                if (need_err)
 197                        close_pair(fderr);
 198                return -ERR_RUN_COMMAND_FORK;
 199        }
 200
 201        if (need_in)
 202                close(fdin[0]);
 203        else if (cmd->in)
 204                close(cmd->in);
 205
 206        if (need_out)
 207                close(fdout[1]);
 208        else if (cmd->out)
 209                close(cmd->out);
 210
 211        if (need_err)
 212                close(fderr[1]);
 213
 214        return 0;
 215}
 216
 217static int wait_or_whine(pid_t pid)
 218{
 219        for (;;) {
 220                int status, code;
 221                pid_t waiting = waitpid(pid, &status, 0);
 222
 223                if (waiting < 0) {
 224                        if (errno == EINTR)
 225                                continue;
 226                        error("waitpid failed (%s)", strerror(errno));
 227                        return -ERR_RUN_COMMAND_WAITPID;
 228                }
 229                if (waiting != pid)
 230                        return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
 231                if (WIFSIGNALED(status))
 232                        return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
 233
 234                if (!WIFEXITED(status))
 235                        return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
 236                code = WEXITSTATUS(status);
 237                if (code)
 238                        return -code;
 239                return 0;
 240        }
 241}
 242
 243int finish_command(struct child_process *cmd)
 244{
 245        return wait_or_whine(cmd->pid);
 246}
 247
 248int run_command(struct child_process *cmd)
 249{
 250        int code = start_command(cmd);
 251        if (code)
 252                return code;
 253        return finish_command(cmd);
 254}
 255
 256static void prepare_run_command_v_opt(struct child_process *cmd,
 257                                      const char **argv,
 258                                      int opt)
 259{
 260        memset(cmd, 0, sizeof(*cmd));
 261        cmd->argv = argv;
 262        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
 263        cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
 264        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
 265}
 266
 267int run_command_v_opt(const char **argv, int opt)
 268{
 269        struct child_process cmd;
 270        prepare_run_command_v_opt(&cmd, argv, opt);
 271        return run_command(&cmd);
 272}
 273
 274int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
 275{
 276        struct child_process cmd;
 277        prepare_run_command_v_opt(&cmd, argv, opt);
 278        cmd.dir = dir;
 279        return run_command(&cmd);
 280}
 281
 282int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
 283{
 284        struct child_process cmd;
 285        prepare_run_command_v_opt(&cmd, argv, opt);
 286        cmd.dir = dir;
 287        cmd.env = env;
 288        return run_command(&cmd);
 289}
 290
 291#ifdef __MINGW32__
 292static __stdcall unsigned run_thread(void *data)
 293{
 294        struct async *async = data;
 295        return async->proc(async->fd_for_proc, async->data);
 296}
 297#endif
 298
 299int start_async(struct async *async)
 300{
 301        int pipe_out[2];
 302
 303        if (pipe(pipe_out) < 0)
 304                return error("cannot create pipe: %s", strerror(errno));
 305        async->out = pipe_out[0];
 306
 307#ifndef __MINGW32__
 308        /* Flush stdio before fork() to avoid cloning buffers */
 309        fflush(NULL);
 310
 311        async->pid = fork();
 312        if (async->pid < 0) {
 313                error("fork (async) failed: %s", strerror(errno));
 314                close_pair(pipe_out);
 315                return -1;
 316        }
 317        if (!async->pid) {
 318                close(pipe_out[0]);
 319                exit(!!async->proc(pipe_out[1], async->data));
 320        }
 321        close(pipe_out[1]);
 322#else
 323        async->fd_for_proc = pipe_out[1];
 324        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
 325        if (!async->tid) {
 326                error("cannot create thread: %s", strerror(errno));
 327                close_pair(pipe_out);
 328                return -1;
 329        }
 330#endif
 331        return 0;
 332}
 333
 334int finish_async(struct async *async)
 335{
 336#ifndef __MINGW32__
 337        int ret = 0;
 338
 339        if (wait_or_whine(async->pid))
 340                ret = error("waitpid (async) failed");
 341#else
 342        DWORD ret = 0;
 343        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
 344                ret = error("waiting for thread failed: %lu", GetLastError());
 345        else if (!GetExitCodeThread(async->tid, &ret))
 346                ret = error("cannot get thread exit code: %lu", GetLastError());
 347        CloseHandle(async->tid);
 348#endif
 349        return ret;
 350}