Switch from vfork to posix_spawn
The macOS 12 SDK has deprecated vfork in preference of posix_spawn or
fork. Switch to posix_spawn with the flag to continue using vfork on
Linux.
diff --git a/src/fileutil.cc b/src/fileutil.cc
index fef8d82..14ee68a 100644
--- a/src/fileutil.cc
+++ b/src/fileutil.cc
@@ -21,6 +21,7 @@
#include <glob.h>
#include <limits.h>
#include <signal.h>
+#include <spawn.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
@@ -34,6 +35,8 @@
#include "log.h"
#include "strutil.h"
+extern char** environ;
+
bool Exists(StringPiece filename) {
CHECK(filename.size() < PATH_MAX);
struct stat st;
@@ -84,52 +87,95 @@
int pipefd[2];
if (pipe(pipefd) != 0)
PERROR("pipe failed");
- int pid;
- if ((pid = vfork())) {
- int status;
- close(pipefd[1]);
- while (true) {
- int result = waitpid(pid, &status, WNOHANG);
- if (result < 0)
- PERROR("waitpid failed");
- while (true) {
- char buf[4096];
- ssize_t r = HANDLE_EINTR(read(pipefd[0], buf, 4096));
- if (r < 0)
- PERROR("read failed");
- if (r == 0)
- break;
- s->append(buf, buf + r);
- }
-
- if (result != 0) {
- break;
- }
- }
- close(pipefd[0]);
-
- return status;
- } else {
- close(pipefd[0]);
- if (redirect_stderr == RedirectStderr::STDOUT) {
- if (dup2(pipefd[1], 2) < 0)
- PERROR("dup2 failed");
- } else if (redirect_stderr == RedirectStderr::DEV_NULL) {
- int fd = open("/dev/null", O_WRONLY);
- if (dup2(fd, 2) < 0)
- PERROR("dup2 failed");
- close(fd);
- }
- if (dup2(pipefd[1], 1) < 0)
- PERROR("dup2 failed");
- close(pipefd[1]);
-
- execvp(argv[0], const_cast<char**>(argv));
- PLOG("execvp for %s failed", argv[0]);
- kill(getppid(), SIGTERM);
- _exit(1);
+ posix_spawn_file_actions_t action;
+ int err = posix_spawn_file_actions_init(&action);
+ if (err != 0) {
+ ERROR("posix_spawn_file_actions_init: %s", strerror(err));
}
+
+ err = posix_spawn_file_actions_addclose(&action, pipefd[0]);
+ if (err != 0) {
+ ERROR("posix_spawn_file_actions_addclose: %s", strerror(err));
+ }
+
+ if (redirect_stderr == RedirectStderr::STDOUT) {
+ err = posix_spawn_file_actions_adddup2(&action, pipefd[1], 2);
+ if (err != 0) {
+ ERROR("posix_spawn_file_actions_adddup2: %s", strerror(err));
+ }
+ } else if (redirect_stderr == RedirectStderr::DEV_NULL) {
+ err =
+ posix_spawn_file_actions_addopen(&action, 2, "/dev/null", O_WRONLY, 0);
+ if (err != 0) {
+ ERROR("posix_spawn_file_actions_addopen: %s", strerror(err));
+ }
+ }
+ err = posix_spawn_file_actions_adddup2(&action, pipefd[1], 1);
+ if (err != 0) {
+ ERROR("posix_spawn_file_actions_adddup2: %s", strerror(err));
+ }
+ err = posix_spawn_file_actions_addclose(&action, pipefd[1]);
+ if (err != 0) {
+ ERROR("posix_spawn_file_actions_addclose: %s", strerror(err));
+ }
+
+ posix_spawnattr_t attr;
+ err = posix_spawnattr_init(&attr);
+ if (err != 0) {
+ ERROR("posix_spawnattr_init: %s", strerror(err));
+ }
+
+ short flags = 0;
+#ifdef POSIX_SPAWN_USEVFORK
+ flags |= POSIX_SPAWN_USEVFORK;
+#endif
+
+ err = posix_spawnattr_setflags(&attr, flags);
+ if (err != 0) {
+ ERROR("posix_spawnattr_setflags: %s", strerror(err));
+ }
+
+ pid_t pid;
+ err = posix_spawn(&pid, argv[0], &action, &attr, const_cast<char**>(argv),
+ environ);
+ if (err != 0) {
+ ERROR("posix_spawn: %s", strerror(err));
+ }
+
+ err = posix_spawnattr_destroy(&attr);
+ if (err != 0) {
+ ERROR("posix_spawnattr_destroy: %s", strerror(err));
+ }
+ err = posix_spawn_file_actions_destroy(&action);
+ if (err != 0) {
+ ERROR("posix_spawn_file_actions_destroy: %s", strerror(err));
+ }
+
+ int status;
+ close(pipefd[1]);
+ while (true) {
+ int result = waitpid(pid, &status, WNOHANG);
+ if (result < 0)
+ PERROR("waitpid failed");
+
+ while (true) {
+ char buf[4096];
+ ssize_t r = HANDLE_EINTR(read(pipefd[0], buf, 4096));
+ if (r < 0)
+ PERROR("read failed");
+ if (r == 0)
+ break;
+ s->append(buf, buf + r);
+ }
+
+ if (result != 0) {
+ break;
+ }
+ }
+ close(pipefd[0]);
+
+ return status;
}
std::string GetExecutablePath() {
