From 1b5f85615a3391b9c7abb749e4c4599815a47b55 Mon Sep 17 00:00:00 2001
From: Brian Fiete <bfiete@gmail.com>
Date: Thu, 13 Jan 2022 11:40:44 -0500
Subject: [PATCH] Disable lto on modules with dll exports (lld-link bug)

---
 IDEHelper/Compiler/BfIRCodeGen.cpp | 5 +++++
 IDEHelper/Compiler/BfIRCodeGen.h   | 1 +
 2 files changed, 6 insertions(+)

diff --git a/IDEHelper/Compiler/BfIRCodeGen.cpp b/IDEHelper/Compiler/BfIRCodeGen.cpp
index 393d992a..d92a6c8c 100644
--- a/IDEHelper/Compiler/BfIRCodeGen.cpp
+++ b/IDEHelper/Compiler/BfIRCodeGen.cpp
@@ -352,6 +352,7 @@ BfIRCodeGen::BfIRCodeGen()
 	mLLVMContext = new llvm::LLVMContext();
 	mLLVMModule = NULL;
 	mIsCodeView = false;
+	mHadDLLExport = false;
 	mConstValIdx = 0;
 	mCmdCount = 0;
 	
@@ -3794,6 +3795,7 @@ void BfIRCodeGen::HandleNextCmd()
 			else if (attribute == BFIRAttribute_DllExport)
 			{
 				func->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
+				mHadDLLExport = true;
 			}
 			else if (attribute == BFIRAttribute_NoFramePointerElim)
 			{
@@ -5314,6 +5316,9 @@ bool BfIRCodeGen::WriteObjectFile(const StringImpl& outFileName)
 		{
 			enableLTO = false;
 		}
+
+		if (mHadDLLExport) // LTO bug in LLVM-link?
+			enableLTO = false;
 	}
 		
 	std::error_code EC;
diff --git a/IDEHelper/Compiler/BfIRCodeGen.h b/IDEHelper/Compiler/BfIRCodeGen.h
index 7cd3868f..ad474f4d 100644
--- a/IDEHelper/Compiler/BfIRCodeGen.h
+++ b/IDEHelper/Compiler/BfIRCodeGen.h
@@ -106,6 +106,7 @@ public:
 	BfCodeGenOptions mCodeGenOptions;
 	bool mHasDebugLoc;	
 	bool mIsCodeView;
+	bool mHadDLLExport;
 	int mConstValIdx;
 
 	int mCmdCount;