From: Duncan P. N. Exon Smith <dexonsmith@apple.com>
Date: Fri, 5 Dec 2014 01:41:34 +0000 (+0000)
Subject: IR: Stop relying on GetStringMapEntryFromValue()
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=397b575f817010a9169b14cfbd8653493cd8ce3e;p=oota-llvm.git

IR: Stop relying on GetStringMapEntryFromValue()

It relies on undefined behaviour.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223438 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/IR/Metadata.h b/include/llvm/IR/Metadata.h
index a056b0d2973..189ea3e73d6 100644
--- a/include/llvm/IR/Metadata.h
+++ b/include/llvm/IR/Metadata.h
@@ -63,8 +63,9 @@ class MDString : public Metadata {
   virtual void anchor();
   MDString(const MDString &) LLVM_DELETED_FUNCTION;
 
+  StringMapEntry<MDString> *Entry;
   explicit MDString(LLVMContext &Context)
-      : Metadata(Context, Value::MDStringVal) {}
+      : Metadata(Context, Value::MDStringVal), Entry(nullptr) {}
 
   /// \brief Shadow Value::getName() to prevent its use.
   StringRef getName() const LLVM_DELETED_FUNCTION;
diff --git a/lib/IR/Metadata.cpp b/lib/IR/Metadata.cpp
index 27ba9f7a87b..3a7c293bcdd 100644
--- a/lib/IR/Metadata.cpp
+++ b/lib/IR/Metadata.cpp
@@ -48,11 +48,13 @@ MDString *MDString::get(LLVMContext &Context, StringRef Str) {
   bool WasInserted = Store.insert(Entry);
   (void)WasInserted;
   assert(WasInserted && "Expected entry to be inserted");
+  Entry->second.Entry = Entry;
   return &Entry->second;
 }
 
 StringRef MDString::getString() const {
-  return StringMapEntry<MDString>::GetStringMapEntryFromValue(*this).first();
+  assert(Entry && "Expected to find string map entry");
+  return Entry->first();
 }
 
 //===----------------------------------------------------------------------===//