[Lldb-commits] [lldb] [lldb/Host] Enable inheriting "non-inheritable" FDs (PR #126935)

[David Spickett via lldb-commits]

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@@ -122,8 +123,14 @@ struct ForkLaunchInfo {
         ExitWithError(error_fd, "close");
       break;
     case FileAction::eFileActionDuplicate:
-      if (dup2(action.fd, action.arg) == -1)
-        ExitWithError(error_fd, "dup2");
+      if (action.fd != action.arg) {
+        if (dup2(action.fd, action.arg) == -1)
+          ExitWithError(error_fd, "dup2");
+      } else {
+        if (fcntl(action.fd, F_SETFD,
+                  fcntl(action.fd, F_GETFD) & ~FD_CLOEXEC) == -1)
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DavidSpickett wrote:

I don't think I knew what I was asking either tbh but I think I understand a bit more now.

You, the current process, are about to exec. So trying to give the new process an fd with O_CLOEXEC set wouldn't make any sense. By the time the new process tried to use it, it's already been closed.

I will see if the code makes more sense to me now.

https://github.com/llvm/llvm-project/pull/126935