Implement function template specialization at class scope extension in Microsoft mode. A new AST node is introduced: ClassScopeFunctionSpecialization. This node holds a FunctionDecl that is not yet specialized; then during the class template instantiation the ClassScopeFunctionSpecialization will spawn the actual function specialization.

Example:
template <class T>
class A {
public:
  template <class U> void f(U p) {  }
  template <> void f(int p) {  } // <== class scope specialization
};

This extension is necessary to parse MSVC standard C++ headers, MFC and ATL code.
BTW, with this feature in, clang can parse (-fsyntax-only) all the MSVC 2010 standard header files without any error.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@137573 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 02bd21fef0..e9d421f0ff 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1568,6 +1568,10 @@ Decl *ASTReader::ReadDeclRecord(DeclID ID) {
     D = ClassTemplatePartialSpecializationDecl::Create(*Context,
                                                        Decl::EmptyShell());
     break;
+  case DECL_CLASS_SCOPE_FUNCTION_SPECIALIZATION:
+    D = ClassScopeFunctionSpecializationDecl::Create(*Context,
+                                                     Decl::EmptyShell());
+    break;
   case DECL_FUNCTION_TEMPLATE:
       D = FunctionTemplateDecl::Create(*Context, Decl::EmptyShell());
     break;