Merge pull request swiftlang#81517 from rintaro/macros-wait-rdar150474701

[Macros] Mitigate plugin process 'wait' failure

Author: rintaro

lib/AST/PluginRegistry.cpp

@@ -213,14 +213,17 @@ LoadedExecutablePlugin::PluginProcess::~PluginProcess() {
 #else
   close(input);
   close(output);
+  kill(process.Pid, SIGTERM);
 #endif
 
   // Set `SecondsToWait` non-zero so it waits for the timeout and kill it after
   // that. Usually when the pipe is closed above, the plugin detects the EOF in
   // the stdin and exits immediately, so this usually doesn't wait for the
   // timeout. Note that we can't use '0' because it performs a non-blocking
-  // wait, which make the plugin a zombie if it hasn't exited.
-  llvm::sys::Wait(process, /*SecondsToWait=*/1);
+  // wait, which make the plugin a zombie if it hasn't exited. We don't use
+  // a small number like '1' because the timeout alarm(3) can fire before the
+  // wait4(2).
+  llvm::sys::Wait(process, /*SecondsToWait=*/10);
 }
 
 ssize_t LoadedExecutablePlugin::PluginProcess::read(void *buf,

lib/Basic/Program.cpp

@@ -123,11 +123,15 @@ swift::ExecuteWithPipe(llvm::StringRef program,
   posix_spawn_file_actions_t FileActions;
   posix_spawn_file_actions_init(&FileActions);
 
+  // Redirect file descriptors...
   posix_spawn_file_actions_adddup2(&FileActions, p1.read, STDIN_FILENO);
-  posix_spawn_file_actions_addclose(&FileActions, p1.write);
-
   posix_spawn_file_actions_adddup2(&FileActions, p2.write, STDOUT_FILENO);
+
+  // Close all file descriptors, not needed as we duped them to the stdio.
+  posix_spawn_file_actions_addclose(&FileActions, p1.read);
+  posix_spawn_file_actions_addclose(&FileActions, p1.write);
   posix_spawn_file_actions_addclose(&FileActions, p2.read);
+  posix_spawn_file_actions_addclose(&FileActions, p2.write);
 
   // Spawn the subtask.
   int error = posix_spawn(&pid, progCStr, &FileActions, nullptr,
@@ -156,13 +160,16 @@ swift::ExecuteWithPipe(llvm::StringRef program,
 
   // Child process.
   case 0:
-    close(p1.write);
-    close(p2.read);
-
     // Redirect file descriptors...
     dup2(p1.read, STDIN_FILENO);
     dup2(p2.write, STDOUT_FILENO);
 
+    // Close all file descriptors, not needed as we duped them to the stdio.
+    close(p1.read);
+    close(p1.write);
+    close(p2.read);
+    close(p2.write);
+
     // Execute the program.
     if (envp) {
       execve(progCStr, const_cast<char **>(argv), const_cast<char **>(envp));
@@ -180,11 +187,12 @@ swift::ExecuteWithPipe(llvm::StringRef program,
 
   // Parent process.
   default:
+    close(p1.read);
+    close(p2.write);
     break;
   }
 #endif
-  close(p1.read);
-  close(p2.write);
+
   llvm::sys::ProcessInfo proc;
   proc.Pid = pid;
   proc.Process = pid;