4 files changed, 53 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 4b2b7b01f17..a03da3c452a 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -364,6 +364,7 @@ bool DwarfDebug::isSubprogramContext(const MDNode *Context) {
 // scope then create and insert DIEs for these variables.
 DIE *DwarfDebug::updateSubprogramScopeDIE(DwarfCompileUnit *SPCU,
                                           DISubprogram SP) {
+  SP = SPCU->getOdrUniqueSubprogram(resolve(SP.getContext()), SP);
   DIE *SPDie = SPCU->getDIE(SP);
 
   assert(SPDie && "Unable to find subprogram DIE!");
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
index bd1d304b71d..baf87323178 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -353,6 +353,9 @@ class DwarfDebug : public AsmPrinterHandler {
   /// of in DwarfCompileUnit.
   DenseMap<const MDNode *, DIE *> MDTypeNodeToDieMap;
 
+  // Used to unique C++ member function declarations.
+  StringMap<const MDNode *> OdrMemberMap;
+
   // Stores the current file ID for a given compile unit.
   DenseMap<unsigned, unsigned> FileIDCUMap;
   // Source id map, i.e. CUID, source filename and directory,
@@ -702,6 +705,11 @@ public:
     return MDTypeNodeToDieMap.lookup(TypeMD);
   }
 
+  /// \brief Look up or create an entry in the OdrMemberMap.
+  const MDNode *&getOrCreateOdrMember(StringRef Key) {
+    return OdrMemberMap.GetOrCreateValue(Key).getValue();
+  }
+
   /// \brief Emit all Dwarf sections that should come prior to the
   /// content.
   void beginModule();
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
index dbdcf9d2e11..836beb89b45 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.cpp
@@ -1405,12 +1405,33 @@ DIE *DwarfUnit::getOrCreateNameSpace(DINameSpace NS) {
   return NDie;
 }
 
+/// Unique C++ member function declarations based on their
+/// context and mangled name.
+DISubprogram
+DwarfUnit::getOdrUniqueSubprogram(DIScope Context, DISubprogram SP) const {
+  if (!hasODR() ||
+      !Context.isCompositeType() ||
+      SP.getLinkageName().empty() ||
+      SP.isDefinition())
+    return SP;
+  // Create a key with the UID of the parent class and this SP's name.
+  Twine Key = SP.getContext().getName() + SP.getLinkageName();
+  const MDNode *&Entry = DD->getOrCreateOdrMember(Key.str());
+  if (!Entry)
+    Entry = &*SP;
+
+  return DISubprogram(Entry);
+}
+
 /// getOrCreateSubprogramDIE - Create new DIE using SP.
 DIE *DwarfUnit::getOrCreateSubprogramDIE(DISubprogram SP) {
   // Construct the context before querying for the existence of the DIE in case
   // such construction creates the DIE (as is the case for member function
   // declarations).
-  DIE *ContextDIE = getOrCreateContextDIE(resolve(SP.getContext()));
+  DIScope Context = resolve(SP.getContext());
+  DIE *ContextDIE = getOrCreateContextDIE(Context);
+  // Unique declarations based on the ODR, where applicable.
+  SP = getOdrUniqueSubprogram(Context, SP);
 
   DIE *SPDie = getDIE(SP);
   if (SPDie)
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
index af465c006ed..d8208737663 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfUnit.h
@@ -485,6 +485,28 @@ public:
 
   virtual DwarfCompileUnit &getCU() = 0;
 
+  /// \brief Return whether this compilation unit has the
+  /// one-definition-rule (ODR).  In C++ this allows the compiler to
+  /// perform type unique during LTO.
+  bool hasODR() const {
+    switch (getLanguage()) {
+    case dwarf::DW_LANG_C_plus_plus:
+    case dwarf::DW_LANG_C_plus_plus_03:
+    case dwarf::DW_LANG_C_plus_plus_11:
+      // For all we care, the C++ part of the language has the ODR and
+      // ObjC methods are not represented in a way that they could be
+      // confused with C++ member functions.
+    case dwarf::DW_LANG_ObjC_plus_plus:
+      return true;
+    default:
+      return false;
+    }
+  }
+
+  /// \brief Unique C++ member function declarations based on their
+  /// context+mangled name.
+  DISubprogram getOdrUniqueSubprogram(DIScope Context, DISubprogram SP) const;
+
 protected:
   /// getOrCreateStaticMemberDIE - Create new static data member DIE.
   DIE *getOrCreateStaticMemberDIE(DIDerivedType DT);