1 files changed, 58 insertions, 21 deletions

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
index e1c51f58087..4b88498e664 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
@@ -63,7 +63,9 @@ extern "C" {
 #include <pthread.h>
 #include <sched.h>
 #include <signal.h>
+#include <spawn.h>
 #include <stdlib.h>
+#include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
@@ -205,27 +207,62 @@ int internal_fork() {
   return fork();
 }
 
-int internal_forkpty(int *amaster) {
-  int master, slave;
-  if (openpty(&master, &slave, nullptr, nullptr, nullptr) == -1) return -1;
-  int pid = internal_fork();
-  if (pid == -1) {
-    close(master);
-    close(slave);
-    return -1;
-  }
-  if (pid == 0) {
-    close(master);
-    if (login_tty(slave) != 0) {
-      // We already forked, there's not much we can do.  Let's quit.
-      Report("login_tty failed (errno %d)\n", errno);
-      internal__exit(1);
-    }
-  } else {
-    *amaster = master;
-    close(slave);
-  }
-  return pid;
+fd_t internal_spawn(const char *argv[], pid_t *pid) {
+  int master_fd = kInvalidFd;
+  int slave_fd = kInvalidFd;
+  char **env = GetEnviron();
+  int res = 0;
+
+  // We need a new pseudoterminal to avoid bufferring problems. The 'atos' tool
+  // in particular detects when it's talking to a pipe and forgets to flush the
+  // output stream after sending a response.
+  master_fd = posix_openpt(O_RDWR);
+  if (master_fd == kInvalidFd) goto cleanup;
+  res = grantpt(master_fd);
+  if (res != 0) goto cleanup;
+  res = unlockpt(master_fd);
+  if (res != 0) goto cleanup;
+
+  // Use TIOCPTYGNAME instead of ptsname() to avoid threading problems.
+  char slave_pty_name[128];
+  res = ioctl(master_fd, TIOCPTYGNAME, slave_pty_name);
+  if (res == -1) goto cleanup;
+
+  slave_fd = internal_open(slave_pty_name, O_RDWR);
+  if (slave_fd == kInvalidFd) goto cleanup;
+
+  posix_spawn_file_actions_t actions;
+  res = posix_spawn_file_actions_init(&actions);
+  if (res != 0) goto cleanup;
+  res = posix_spawn_file_actions_adddup2(&actions, slave_fd, STDIN_FILENO);
+  if (res != 0) goto cleanup;
+  res = posix_spawn_file_actions_adddup2(&actions, slave_fd, STDOUT_FILENO);
+  if (res != 0) goto cleanup;
+  res = posix_spawn_file_actions_addclose(&actions, slave_fd);
+  if (res != 0) goto cleanup;
+  res = posix_spawn_file_actions_addclose(&actions, master_fd);
+  if (res != 0) goto cleanup;
+
+  res = posix_spawnp(pid, argv[0], &actions, NULL, const_cast<char **>(argv),
+                     env);
+  if (res != 0) goto cleanup;
+
+  internal_close(slave_fd);
+  slave_fd = kInvalidFd;
+
+  // Disable echo in the new terminal, disable CR.
+  struct termios termflags;
+  tcgetattr(master_fd, &termflags);
+  termflags.c_oflag &= ~ONLCR;
+  termflags.c_lflag &= ~ECHO;
+  tcsetattr(master_fd, TCSANOW, &termflags);
+
+  return master_fd;
+
+ cleanup:
+  if (master_fd != kInvalidFd) internal_close(master_fd);
+  if (slave_fd != kInvalidFd) internal_close(slave_fd);
+  return kInvalidFd;
 }
 
 uptr internal_rename(const char *oldpath, const char *newpath) {