From 4b02d18ca2e6664c527cbb1abffa9dedae3ce9a3 Mon Sep 17 00:00:00 2001
From: Tex Riddell <texr@microsoft.com>
Date: Mon, 12 Mar 2018 20:09:24 +0000
Subject: [PATCH] Merged PR 39: Linker: add resources to LLVMUsed so they don't
 get deleted prematurely

Linker: add resources to LLVMUsed so they don't get deleted prematurely
---
 lib/HLSL/DxilLinker.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/HLSL/DxilLinker.cpp b/lib/HLSL/DxilLinker.cpp
index 1be26adaf..6c4f1459f 100644
--- a/lib/HLSL/DxilLinker.cpp
+++ b/lib/HLSL/DxilLinker.cpp
@@ -506,7 +506,11 @@ void DxilLinkJob::AddResourceToDM(DxilModule &DM) {
     basePtr->SetID(ID);
 
     basePtr->SetGlobalSymbol(GV);
+    DM.GetLLVMUsed().push_back(GV);
   }
+  // Prevent global vars used for resources from being deleted through optimizations
+  // while we still have hidden uses (pointers in resource vectors).
+  DM.EmitLLVMUsed();
 }
 
 void DxilLinkJob::LinkNamedMDNodes(Module *pM, ValueToValueMapTy &vmap) {
@@ -769,7 +773,7 @@ DxilLinkJob::Link(std::pair<DxilFunctionLinkInfo *, DxilLib *> &entryLinkPair,
   // Add resource to DM.
   // This should be after functions cloned.
   AddResourceToDM(DM);
-  
+
   // Link metadata like debug info.
   LinkNamedMDNodes(pM.get(), vmap);