2 files changed, 46 insertions, 28 deletions

diff --git a/llvm/include/llvm/MC/MCAssembler.h b/llvm/include/llvm/MC/MCAssembler.h
index 368846a6efe..427c1099d58 100644
--- a/llvm/include/llvm/MC/MCAssembler.h
+++ b/llvm/include/llvm/MC/MCAssembler.h
@@ -12,6 +12,7 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/ilist.h"
@@ -551,11 +552,11 @@ class MCAssembler {
   friend class MCAsmLayout;
 
 public:
-  typedef iplist<MCSectionData> SectionDataListType;
+  typedef SetVector<MCSection *> SectionListType;
   typedef std::vector<const MCSymbol *> SymbolDataListType;
 
-  typedef SectionDataListType::const_iterator const_iterator;
-  typedef SectionDataListType::iterator iterator;
+  typedef pointee_iterator<SectionListType::const_iterator> const_iterator;
+  typedef pointee_iterator<SectionListType::iterator> iterator;
 
   typedef pointee_iterator<SymbolDataListType::const_iterator>
   const_symbol_iterator;
@@ -599,17 +600,12 @@ private:
 
   raw_ostream &OS;
 
-  iplist<MCSectionData> Sections;
+  SectionListType Sections;
 
   SymbolDataListType Symbols;
 
   DenseSet<const MCSymbol *> LocalsUsedInReloc;
 
-  /// The map of sections to their associated assembler backend data.
-  //
-  // FIXME: Avoid this indirection?
-  DenseMap<const MCSection *, MCSectionData *> SectionMap;
-
   std::vector<IndirectSymbolData> IndirectSymbols;
 
   std::vector<DataRegionData> DataRegions;
@@ -888,24 +884,22 @@ public:
   /// \name Backend Data Access
   /// @{
 
-  MCSectionData &getSectionData(const MCSection &Section) const {
-    MCSectionData *Entry = SectionMap.lookup(&Section);
-    assert(Entry && "Missing section data!");
-    return *Entry;
+  MCSectionData &getSectionData(MCSection &Section) {
+    assert(Sections.count(&Section) && "Unknown Seciton");
+    return Section.getSectionData();
+  }
+
+  const MCSectionData &getSectionData(const MCSection &Section) const {
+    return const_cast<MCAssembler *>(this)
+        ->getSectionData(const_cast<MCSection &>(Section));
   }
 
   MCSectionData &getOrCreateSectionData(MCSection &Section,
                                         bool *Created = nullptr) {
-    MCSectionData *&Entry = SectionMap[&Section];
-
+    bool C = Sections.insert(&Section);
     if (Created)
-      *Created = !Entry;
-    if (!Entry) {
-      Entry = new MCSectionData(Section);
-      Sections.push_back(Entry);
-    }
-
-    return *Entry;
+      *Created = C;
+    return Section.getSectionData();
   }
 
   bool hasSymbolData(const MCSymbol &Symbol) const { return Symbol.hasData(); }
diff --git a/llvm/include/llvm/MC/MCSection.h b/llvm/include/llvm/MC/MCSection.h
index 5b1aeda126d..5ca83398bd0 100644
--- a/llvm/include/llvm/MC/MCSection.h
+++ b/llvm/include/llvm/MC/MCSection.h
@@ -31,7 +31,7 @@ class MCSection;
 class MCSymbol;
 class raw_ostream;
 
-class MCSectionData : public ilist_node<MCSectionData> {
+class MCSectionData {
   friend class MCAsmLayout;
 
   MCSectionData(const MCSectionData &) = delete;
@@ -62,9 +62,7 @@ private:
   /// @}
 
 public:
-  // Only for use as sentinel.
-  MCSectionData();
-  MCSectionData(MCSection &Section);
+  explicit MCSectionData(MCSection &Section);
 
   MCSection &getSection() const { return *Section; }
 
@@ -144,9 +142,10 @@ private:
   /// Whether this section has had instructions emitted into it.
   unsigned HasInstructions : 1;
 
+  MCSectionData Data;
+
 protected:
-  MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin)
-      : Begin(Begin), HasInstructions(false), Variant(V), Kind(K) {}
+  MCSection(SectionVariant V, SectionKind K, MCSymbol *Begin);
   SectionVariant Variant;
   SectionKind Kind;
 
@@ -191,6 +190,31 @@ public:
   bool hasInstructions() const { return HasInstructions; }
   void setHasInstructions(bool Value) { HasInstructions = Value; }
 
+  MCSectionData &getSectionData() { return Data; }
+  const MCSectionData &getSectionData() const {
+    return const_cast<MCSection *>(this)->getSectionData();
+  }
+
+  MCSectionData::FragmentListType &getFragmentList();
+  const MCSectionData::FragmentListType &getFragmentList() const {
+    return const_cast<MCSection *>(this)->getFragmentList();
+  }
+
+  MCSectionData::iterator begin();
+  MCSectionData::const_iterator begin() const {
+    return const_cast<MCSection *>(this)->begin();
+  }
+
+  MCSectionData::iterator end();
+  MCSectionData::const_iterator end() const {
+    return const_cast<MCSection *>(this)->end();
+  }
+
+  MCSectionData::reverse_iterator rend();
+  MCSectionData::const_reverse_iterator rend() const {
+    return const_cast<MCSection *>(this)->rend();
+  }
+
   virtual void PrintSwitchToSection(const MCAsmInfo &MAI, raw_ostream &OS,
                                     const MCExpr *Subsection) const = 0;