[LLDB][Windows]: Don't pass duplicate HANDLEs to CreateProcess

[lb90]

CreateProcess fails with ERROR_INVALID_PARAMETER when duplicate HANDLEs are passed via PROC_THREAD_ATTRIBUTE_HANDLE_LIST. This can happen, for example, if stdout and stdin are the same device (e.g. a bidirectional named pipe), or if stdout and stderr are the same device.

Fixes msys2/MINGW-packages#26030

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[llvmbot]

@llvm/pr-subscribers-lldb

Author: None (lb90)

Changes

Fixes msys2/MINGW-packages#26030

---

Full diff: https://github.com/llvm/llvm-project/pull/165281.diff

1 Files Affected:

• (modified) lldb/source/Host/windows/ProcessLauncherWindows.cpp (+6)

diff --git a/lldb/source/Host/windows/ProcessLauncherWindows.cpp b/lldb/source/Host/windows/ProcessLauncherWindows.cpp
index f5adadaf061bf..ab151f1a9a0ac 100644
--- a/lldb/source/Host/windows/ProcessLauncherWindows.cpp
+++ b/lldb/source/Host/windows/ProcessLauncherWindows.cpp
@@ -15,6 +15,7 @@
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/Program.h"
 
+#include <algorithm>
 #include <string>
 #include <vector>
 
@@ -122,6 +123,11 @@ ProcessLauncherWindows::LaunchProcess(const ProcessLaunchInfo &launch_info,
         act->GetFD() == act->GetActionArgument())
       inherited_handles.push_back(reinterpret_cast<HANDLE>(act->GetFD()));
   }
+  // Remove duplicate HANDLEs
+  std::sort(inherited_handles.begin(), inherited_handles.end());
+  inherited_handles.erase(
+      std::unique(inherited_handles.begin(), inherited_handles.end()),
+      inherited_handles.end());
   if (!inherited_handles.empty()) {
     if (!UpdateProcThreadAttribute(
             startupinfoex.lpAttributeList, /*dwFlags=*/0,

[charles-zablit]

Thanks for submitting this patch!

This looks good to me, I just wonder if it would make sense to convert this inherited_handles vector to an std::unordered_set?

I think It would make it clearer that we should only have unique handles in this data structure. What do you think?

[lb90]

Nice idea! Changed :)

[charles-zablit]

Thank you for this patch!