From 1f8008cf214b984954de2e986fb8cb0e5cc58606 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Mon, 15 Mar 2010 06:23:52 +0000
Subject: [PATCH] fix MCSectionELF to not leak memory, just like I did for
 MCSymbol. MCSectionMachO is already fine (yay for fixed size arrays?),
 MCSectionCOFF still leaks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98537 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/llvm/MC/MCSection.h                  |  2 ++
 include/llvm/MC/MCSectionELF.h               |  9 ++++-----
 lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 10 ++++++----
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/include/llvm/MC/MCSection.h b/include/llvm/MC/MCSection.h
index ceb6d278c9c..3d8815a7783 100644
--- a/include/llvm/MC/MCSection.h
+++ b/include/llvm/MC/MCSection.h
@@ -42,6 +42,8 @@ namespace llvm {
   };
 
   class MCSectionCOFF : public MCSection {
+    // FIXME: This memory is leaked because MCSectionCOFF is bump pointer
+    // allocated and this never gets freed.
     std::string Name;
     
     /// IsDirective - This is true if the section name is a directive, not
diff --git a/include/llvm/MC/MCSectionELF.h b/include/llvm/MC/MCSectionELF.h
index 2dccf5c5728..41c17bd8fa1 100644
--- a/include/llvm/MC/MCSectionELF.h
+++ b/include/llvm/MC/MCSectionELF.h
@@ -21,7 +21,9 @@ namespace llvm {
 /// MCSectionELF - This represents a section on linux, lots of unix variants
 /// and some bare metal systems.
 class MCSectionELF : public MCSection {
-  std::string SectionName;
+  /// SectionName - This is the name of the section.  The referenced memory is
+  /// owned by TargetLoweringObjectFileELF's ELFUniqueMap.
+  StringRef SectionName;
   
   /// Type - This is the sh_type field of a section, drawn from the enums below.
   unsigned Type;
@@ -163,10 +165,7 @@ public:
     TARGET_INDEP_SHF     = FIRST_TARGET_DEP_FLAG-1U
   };
 
-  StringRef getSectionName() const {
-    return StringRef(SectionName);
-  }
-  
+  StringRef getSectionName() const { return SectionName; }
   unsigned getType() const { return Type; }
   unsigned getFlags() const { return Flags; }
   
diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index 788bbf11908..05e0ea8dfc1 100644
--- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -53,11 +53,13 @@ getELFSection(StringRef Section, unsigned Type, unsigned Flags,
   ELFUniqueMapTy &Map = *(ELFUniqueMapTy*)UniquingMap;
 
   // Do the lookup, if we have a hit, return it.
-  const MCSectionELF *&Entry = Map[Section];
-  if (Entry) return Entry;
+  StringMapEntry<const MCSectionELF*> &Entry = Map.GetOrCreateValue(Section);
+  if (Entry.getValue()) return Entry.getValue();
 
-  return Entry = MCSectionELF::Create(Section, Type, Flags, Kind, IsExplicit,
-                                      getContext());
+  MCSectionELF *Result = MCSectionELF::Create(Entry.getKey(), Type, Flags, Kind,
+                                              IsExplicit, getContext());
+  Entry.setValue(Result);
+  return Result;
 }
 
 void TargetLoweringObjectFileELF::Initialize(MCContext &Ctx,
-- 
2.34.1