Don't smash stack when $GIT_ALTERNATE_OBJECT_DIRECTORIES is too long

[git.git] / run-command.c

diff --git a/run-command.c b/run-command.c
index 61908682b9b251ac49ae655522a3143476a888ea..eff523e191b35385895f6b077fc76c7c21819012 100644 (file)
--- a/run-command.c
+++ b/run-command.c
@@ -1,31 +1,109 @@
 #include "cache.h"
 #include "run-command.h"
-#include <sys/wait.h>
 #include "exec_cmd.h"
 
-int run_command_v_opt(int argc, const char **argv, int flags)
+static inline void close_pair(int fd[2])
 {
-       pid_t pid = fork();
+       close(fd[0]);
+       close(fd[1]);
+}
+
+static inline void dup_devnull(int to)
+{
+       int fd = open("/dev/null", O_RDWR);
+       dup2(fd, to);
+       close(fd);
+}
+
+int start_command(struct child_process *cmd)
+{
+       int need_in, need_out;
+       int fdin[2], fdout[2];
 
-       if (pid < 0)
+       need_in = !cmd->no_stdin && cmd->in < 0;
+       if (need_in) {
+               if (pipe(fdin) < 0)
+                       return -ERR_RUN_COMMAND_PIPE;
+               cmd->in = fdin[1];
+               cmd->close_in = 1;
+       }
+
+       need_out = !cmd->no_stdout
+               && !cmd->stdout_to_stderr
+               && cmd->out < 0;
+       if (need_out) {
+               if (pipe(fdout) < 0) {
+                       if (need_in)
+                               close_pair(fdin);
+                       return -ERR_RUN_COMMAND_PIPE;
+               }
+               cmd->out = fdout[0];
+               cmd->close_out = 1;
+       }
+
+       cmd->pid = fork();
+       if (cmd->pid < 0) {
+               if (need_in)
+                       close_pair(fdin);
+               if (need_out)
+                       close_pair(fdout);
                return -ERR_RUN_COMMAND_FORK;
-       if (!pid) {
-               if (flags & RUN_COMMAND_NO_STDIO) {
-                       int fd = open("/dev/null", O_RDWR);
-                       dup2(fd, 0);
-                       dup2(fd, 1);
-                       close(fd);
+       }
+
+       if (!cmd->pid) {
+               if (cmd->no_stdin)
+                       dup_devnull(0);
+               else if (need_in) {
+                       dup2(fdin[0], 0);
+                       close_pair(fdin);
+               } else if (cmd->in) {
+                       dup2(cmd->in, 0);
+                       close(cmd->in);
+               }
+
+               if (cmd->no_stdout)
+                       dup_devnull(1);
+               else if (cmd->stdout_to_stderr)
+                       dup2(2, 1);
+               else if (need_out) {
+                       dup2(fdout[1], 1);
+                       close_pair(fdout);
+               } else if (cmd->out > 1) {
+                       dup2(cmd->out, 1);
+                       close(cmd->out);
                }
-               if (flags & RUN_GIT_CMD) {
-                       execv_git_cmd(argv);
+
+               if (cmd->git_cmd) {
+                       execv_git_cmd(cmd->argv);
                } else {
-                       execvp(argv[0], (char *const*) argv);
+                       execvp(cmd->argv[0], (char *const*) cmd->argv);
                }
-               die("exec %s failed.", argv[0]);
+               die("exec %s failed.", cmd->argv[0]);
        }
+
+       if (need_in)
+               close(fdin[0]);
+       else if (cmd->in)
+               close(cmd->in);
+
+       if (need_out)
+               close(fdout[1]);
+       else if (cmd->out > 1)
+               close(cmd->out);
+
+       return 0;
+}
+
+int finish_command(struct child_process *cmd)
+{
+       if (cmd->close_in)
+               close(cmd->in);
+       if (cmd->close_out)
+               close(cmd->out);
+
        for (;;) {
                int status, code;
-               pid_t waiting = waitpid(pid, &status, 0);
+               pid_t waiting = waitpid(cmd->pid, &status, 0);
 
                if (waiting < 0) {
                        if (errno == EINTR)
@@ -33,7 +111,7 @@ int run_command_v_opt(int argc, const char **argv, int flags)
                        error("waitpid failed (%s)", strerror(errno));
                        return -ERR_RUN_COMMAND_WAITPID;
                }
-               if (waiting != pid)
+               if (waiting != cmd->pid)
                        return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
                if (WIFSIGNALED(status))
                        return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
@@ -47,28 +125,21 @@ int run_command_v_opt(int argc, const char **argv, int flags)
        }
 }
 
-int run_command_v(int argc, const char **argv)
+int run_command(struct child_process *cmd)
 {
-       return run_command_v_opt(argc, argv, 0);
+       int code = start_command(cmd);
+       if (code)
+               return code;
+       return finish_command(cmd);
 }
 
-int run_command(const char *cmd, ...)
+int run_command_v_opt(const char **argv, int opt)
 {
-       int argc;
-       const char *argv[MAX_RUN_COMMAND_ARGS];
-       const char *arg;
-       va_list param;
-
-       va_start(param, cmd);
-       argv[0] = (char*) cmd;
-       argc = 1;
-       while (argc < MAX_RUN_COMMAND_ARGS) {
-               arg = argv[argc++] = va_arg(param, char *);
-               if (!arg)
-                       break;
-       }
-       va_end(param);
-       if (MAX_RUN_COMMAND_ARGS <= argc)
-               return error("too many args to run %s", cmd);
-       return run_command_v_opt(argc, argv, 0);
+       struct child_process cmd;
+       memset(&cmd, 0, sizeof(cmd));
+       cmd.argv = argv;
+       cmd.no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
+       cmd.git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
+       cmd.stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
+       return run_command(&cmd);
 }