From 7bcf44ee14947ad934d2d0702b80beffeb1dc05d Mon Sep 17 00:00:00 2001
From: Pirama Arumuga Nainar <pirama@google.com>
Date: Wed, 28 Aug 2019 17:43:14 +0000
Subject: [PATCH] [ValueMapper] NFC: Remove dead code to pause metadata mapping

Summary:
This functionality was added when Mapper::mapMetadata was recursive.  It
is no longer needed after r265456, which switched it to be iterative.

Reviewers: dexonsmith, srhines

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66860

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370236 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/IR/ValueMap.h           |  5 -----
 lib/Transforms/Utils/ValueMapper.cpp | 17 -----------------
 2 files changed, 22 deletions(-)

diff --git a/include/llvm/IR/ValueMap.h b/include/llvm/IR/ValueMap.h
index faa27039af1..fb5440d5efe 100644
--- a/include/llvm/IR/ValueMap.h
+++ b/include/llvm/IR/ValueMap.h
@@ -93,7 +93,6 @@ class ValueMap {
   MapT Map;
   Optional<MDMapT> MDMap;
   ExtraData Data;
-  bool MayMapMetadata = true;
 
 public:
   using key_type = KeyT;
@@ -120,10 +119,6 @@ public:
   }
   Optional<MDMapT> &getMDMap() { return MDMap; }
 
-  bool mayMapMetadata() const { return MayMapMetadata; }
-  void enableMapMetadata() { MayMapMetadata = true; }
-  void disableMapMetadata() { MayMapMetadata = false; }
-
   /// Get the mapped metadata, if it's in the map.
   Optional<Metadata *> getMappedMD(const Metadata *MD) const {
     if (!MDMap)
diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
index 6aca0e417bb..da68d3713b4 100644
--- a/lib/Transforms/Utils/ValueMapper.cpp
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -774,20 +774,6 @@ Metadata *MDNodeMapper::mapTopLevelUniquedNode(const MDNode &FirstN) {
   return *getMappedOp(&FirstN);
 }
 
-namespace {
-
-struct MapMetadataDisabler {
-  ValueToValueMapTy &VM;
-
-  MapMetadataDisabler(ValueToValueMapTy &VM) : VM(VM) {
-    VM.disableMapMetadata();
-  }
-
-  ~MapMetadataDisabler() { VM.enableMapMetadata(); }
-};
-
-} // end anonymous namespace
-
 Optional<Metadata *> Mapper::mapSimpleMetadata(const Metadata *MD) {
   // If the value already exists in the map, use it.
   if (Optional<Metadata *> NewMD = getVM().getMappedMD(MD))
@@ -802,9 +788,6 @@ Optional<Metadata *> Mapper::mapSimpleMetadata(const Metadata *MD) {
     return const_cast<Metadata *>(MD);
 
   if (auto *CMD = dyn_cast<ConstantAsMetadata>(MD)) {
-    // Disallow recursion into metadata mapping through mapValue.
-    MapMetadataDisabler MMD(getVM());
-
     // Don't memoize ConstantAsMetadata.  Instead of lasting until the
     // LLVMContext is destroyed, they can be deleted when the GlobalValue they
     // reference is destructed.  These aren't super common, so the extra
-- 
2.40.0