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 cmd->pid = fork();
72 if (!cmd->pid) {
73 if (cmd->no_stdin)
74 dup_devnull(0);
75 else if (need_in) {
76 dup2(fdin[0], 0);
77 close_pair(fdin);
78 } else if (cmd->in) {
79 dup2(cmd->in, 0);
80 close(cmd->in);
81 }
82
83 if (cmd->no_stderr)
84 dup_devnull(2);
85 else if (need_err) {
86 dup2(fderr[1], 2);
87 close_pair(fderr);
88 }
89
90 if (cmd->no_stdout)
91 dup_devnull(1);
92 else if (cmd->stdout_to_stderr)
93 dup2(2, 1);
94 else if (need_out) {
95 dup2(fdout[1], 1);
96 close_pair(fdout);
97 } else if (cmd->out > 1) {
98 dup2(cmd->out, 1);
99 close(cmd->out);
100 }
101
102 if (cmd->dir && chdir(cmd->dir))
103 die("exec %s: cd to %s failed (%s)", cmd->argv[0],
104 cmd->dir, strerror(errno));
105 if (cmd->env) {
106 for (; *cmd->env; cmd->env++) {
107 if (strchr(*cmd->env, '='))
108 putenv((char*)*cmd->env);
109 else
110 unsetenv(*cmd->env);
111 }
112 }
113 if (cmd->git_cmd) {
114 execv_git_cmd(cmd->argv);
115 } else {
116 execvp(cmd->argv[0], (char *const*) cmd->argv);
117 }
118 die("exec %s failed.", cmd->argv[0]);
119 }
120#else
121 int s0 = -1, s1 = -1, s2 = -1; /* backups of stdin, stdout, stderr */
122 const char **sargv = cmd->argv;
123 char **env = environ;
124
125 if (cmd->no_stdin) {
126 s0 = dup(0);
127 dup_devnull(0);
128 } else if (need_in) {
129 s0 = dup(0);
130 dup2(fdin[0], 0);
131 } else if (cmd->in) {
132 s0 = dup(0);
133 dup2(cmd->in, 0);
134 }
135
136 if (cmd->no_stderr) {
137 s2 = dup(2);
138 dup_devnull(2);
139 } else if (need_err) {
140 s2 = dup(2);
141 dup2(fderr[1], 2);
142 }
143
144 if (cmd->no_stdout) {
145 s1 = dup(1);
146 dup_devnull(1);
147 } else if (cmd->stdout_to_stderr) {
148 s1 = dup(1);
149 dup2(2, 1);
150 } else if (need_out) {
151 s1 = dup(1);
152 dup2(fdout[1], 1);
153 } else if (cmd->out > 1) {
154 s1 = dup(1);
155 dup2(cmd->out, 1);
156 }
157
158 if (cmd->dir)
159 die("chdir in start_command() not implemented");
160 if (cmd->env) {
161 env = copy_environ();
162 for (; *cmd->env; cmd->env++)
163 env = env_setenv(env, *cmd->env);
164 }
165
166 if (cmd->git_cmd) {
167 cmd->argv = prepare_git_cmd(cmd->argv);
168 }
169
170 cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
171
172 if (cmd->env)
173 free_environ(env);
174 if (cmd->git_cmd)
175 free(cmd->argv);
176
177 cmd->argv = sargv;
178 if (s0 >= 0)
179 dup2(s0, 0), close(s0);
180 if (s1 >= 0)
181 dup2(s1, 1), close(s1);
182 if (s2 >= 0)
183 dup2(s2, 2), close(s2);
184#endif
185
186 if (cmd->pid < 0) {
187 if (need_in)
188 close_pair(fdin);
189 else if (cmd->in)
190 close(cmd->in);
191 if (need_out)
192 close_pair(fdout);
193 else if (cmd->out)
194 close(cmd->out);
195 if (need_err)
196 close_pair(fderr);
197 return -ERR_RUN_COMMAND_FORK;
198 }
199
200 if (need_in)
201 close(fdin[0]);
202 else if (cmd->in)
203 close(cmd->in);
204
205 if (need_out)
206 close(fdout[1]);
207 else if (cmd->out)
208 close(cmd->out);
209
210 if (need_err)
211 close(fderr[1]);
212
213 return 0;
214}
215
216static int wait_or_whine(pid_t pid)
217{
218 for (;;) {
219 int status, code;
220 pid_t waiting = waitpid(pid, &status, 0);
221
222 if (waiting < 0) {
223 if (errno == EINTR)
224 continue;
225 error("waitpid failed (%s)", strerror(errno));
226 return -ERR_RUN_COMMAND_WAITPID;
227 }
228 if (waiting != pid)
229 return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
230 if (WIFSIGNALED(status))
231 return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
232
233 if (!WIFEXITED(status))
234 return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
235 code = WEXITSTATUS(status);
236 if (code)
237 return -code;
238 return 0;
239 }
240}
241
242int finish_command(struct child_process *cmd)
243{
244 return wait_or_whine(cmd->pid);
245}
246
247int run_command(struct child_process *cmd)
248{
249 int code = start_command(cmd);
250 if (code)
251 return code;
252 return finish_command(cmd);
253}
254
255static void prepare_run_command_v_opt(struct child_process *cmd,
256 const char **argv,
257 int opt)
258{
259 memset(cmd, 0, sizeof(*cmd));
260 cmd->argv = argv;
261 cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
262 cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
263 cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
264}
265
266int run_command_v_opt(const char **argv, int opt)
267{
268 struct child_process cmd;
269 prepare_run_command_v_opt(&cmd, argv, opt);
270 return run_command(&cmd);
271}
272
273int run_command_v_opt_cd(const char **argv, int opt, const char *dir)
274{
275 struct child_process cmd;
276 prepare_run_command_v_opt(&cmd, argv, opt);
277 cmd.dir = dir;
278 return run_command(&cmd);
279}
280
281int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
282{
283 struct child_process cmd;
284 prepare_run_command_v_opt(&cmd, argv, opt);
285 cmd.dir = dir;
286 cmd.env = env;
287 return run_command(&cmd);
288}
289
290#ifdef __MINGW32__
291static __stdcall unsigned run_thread(void *data)
292{
293 struct async *async = data;
294 return async->proc(async->fd_for_proc, async->data);
295}
296#endif
297
298int start_async(struct async *async)
299{
300 int pipe_out[2];
301
302 if (pipe(pipe_out) < 0)
303 return error("cannot create pipe: %s", strerror(errno));
304 async->out = pipe_out[0];
305
306#ifndef __MINGW32__
307 async->pid = fork();
308 if (async->pid < 0) {
309 error("fork (async) failed: %s", strerror(errno));
310 close_pair(pipe_out);
311 return -1;
312 }
313 if (!async->pid) {
314 close(pipe_out[0]);
315 exit(!!async->proc(pipe_out[1], async->data));
316 }
317 close(pipe_out[1]);
318#else
319 async->fd_for_proc = pipe_out[1];
320 async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
321 if (!async->tid) {
322 error("cannot create thread: %s", strerror(errno));
323 close_pair(pipe_out);
324 return -1;
325 }
326#endif
327 return 0;
328}
329
330int finish_async(struct async *async)
331{
332#ifndef __MINGW32__
333 int ret = 0;
334
335 if (wait_or_whine(async->pid))
336 ret = error("waitpid (async) failed");
337#else
338 DWORD ret = 0;
339 if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
340 ret = error("waiting for thread failed: %lu", GetLastError());
341 else if (!GetExitCodeThread(async->tid, &ret))
342 ret = error("cannot get thread exit code: %lu", GetLastError());
343 CloseHandle(async->tid);
344#endif
345 return ret;
346}