1 files changed, 38 insertions, 5 deletions

diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
index dc5d49b5c53..b977e298be6 100644
--- a/clang/include/clang/AST/DeclTemplate.h
+++ b/clang/include/clang/AST/DeclTemplate.h
@@ -901,9 +901,22 @@ class ClassTemplateSpecializationDecl
   llvm::PointerUnion<ClassTemplateDecl *, SpecializedPartialSpecialization *>
     SpecializedTemplate;
 
-  /// \brief The type-as-written of an explicit template specialization.
+  /// \brief Further info for explicit template specialization/instantiation.
+  struct ExplicitSpecializationInfo {
+    /// \brief The type-as-written.
+    TypeSourceInfo *TypeAsWritten;
+    /// \brief The location of the extern keyword.
+    SourceLocation ExternLoc;
+    /// \brief The location of the template keyword.
+    SourceLocation TemplateKeywordLoc;
+
+    ExplicitSpecializationInfo()
+      : TypeAsWritten(0), ExternLoc(), TemplateKeywordLoc() {}
+  };
+
+  /// \brief Further info for explicit template specialization/instantiation.
   /// Does not apply to implicit specializations.
-  TypeSourceInfo *TypeAsWritten;
+  ExplicitSpecializationInfo *ExplicitInfo;
 
   /// \brief The template arguments used to describe this specialization.
   TemplateArgumentList TemplateArgs;
@@ -1018,13 +1031,33 @@ public:
   /// \brief Sets the type of this specialization as it was written by
   /// the user. This will be a class template specialization type.
   void setTypeAsWritten(TypeSourceInfo *T) {
-    TypeAsWritten = T;
+    if (!ExplicitInfo) ExplicitInfo = new ExplicitSpecializationInfo;
+    ExplicitInfo->TypeAsWritten = T;
   }
-
   /// \brief Gets the type of this specialization as it was written by
   /// the user, if it was so written.
   TypeSourceInfo *getTypeAsWritten() const {
-    return TypeAsWritten;
+    return ExplicitInfo ? ExplicitInfo->TypeAsWritten : 0;
+  }
+
+  /// \brief Gets the location of the extern keyword, if present.
+  SourceLocation getExternLoc() const {
+    return ExplicitInfo ? ExplicitInfo->ExternLoc : SourceLocation();
+  }
+  /// \brief Sets the location of the extern keyword.
+  void setExternLoc(SourceLocation Loc) {
+    if (!ExplicitInfo) ExplicitInfo = new ExplicitSpecializationInfo;
+    ExplicitInfo->ExternLoc = Loc;
+  }
+
+  /// \brief Sets the location of the template keyword.
+  void setTemplateKeywordLoc(SourceLocation Loc) {
+    if (!ExplicitInfo) ExplicitInfo = new ExplicitSpecializationInfo;
+    ExplicitInfo->TemplateKeywordLoc = Loc;
+  }
+  /// \brief Gets the location of the template keyword, if present.
+  SourceLocation getTemplateKeywordLoc() const {
+    return ExplicitInfo ? ExplicitInfo->TemplateKeywordLoc : SourceLocation();
   }
 
   void Profile(llvm::FoldingSetNodeID &ID) const {