Just mangle substituted template parameter types as unresolved types.

This is kindof questionable but seems to do more-or-less the right thing.
This is not a particularly friendly part of the ABI.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@134227 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/ItaniumMangle.cpp

@@ -818,28 +818,21 @@ void CXXNameMangler::mangleUnresolvedPrefix(NestedNameSpecifier *qualifier,
     case Type::Decltype:
     case Type::TemplateTypeParm:
     case Type::UnaryTransform:
+    case Type::SubstTemplateTypeParm:
     unresolvedType:
       assert(!qualifier->getPrefix());
 
       // We only get here recursively if we're followed by identifiers.
       if (recursive) Out << 'N';
 
-      // This seems to do everything we want.
+      // This seems to do everything we want.  It's not really
+      // sanctioned for a substituted template parameter, though.
       mangleType(QualType(type, 0));
 
       // We never want to print 'E' directly after an unresolved-type,
       // so we return directly.
       return;
 
-    // Substituted template type parameters should only come up with
-    // enclosing templates.
-    // <unresolved-type> ::= <existing-substitution> [ <template-args> ]
-    case Type::SubstTemplateTypeParm: {
-      if (recursive) Out << 'N';
-      mangleExistingSubstitution(QualType(type, 0));
-      return;
-    }
-
     case Type::Typedef:
       mangleSourceName(cast<TypedefType>(type)->getDecl()->getIdentifier());
       break;

test/CodeGenCXX/mangle.cpp

@@ -770,3 +770,35 @@ namespace test31 { // instantiation-dependent mangling of decltype
   // CHECK: define weak_odr void @_ZN6test312f3IiEEDTcl1gfp_EET_
   template void f3(int);
 }
+
+// PR10205
+namespace test32 {
+  template<typename T, int=T::value> struct A {
+    typedef int type;
+  };
+  struct B { enum { value = 4 }; };
+
+  template <class T> typename A<T>::type foo() { return 0; }
+  void test() {
+    foo<B>();
+    // CHECK: call i32 @_ZN6test323fooINS_1BEEENS_1AIT_XsrS3_5valueEE4typeEv()
+  }
+}
+
+namespace test33 {
+  template <class T> struct X {
+    enum { value = T::value };
+  };
+
+  template<typename T, int=X<T>::value> struct A {
+    typedef int type;
+  };
+  struct B { enum { value = 4 }; };
+
+  template <class T> typename A<T>::type foo() { return 0; }
+
+  void test() {
+    foo<B>();
+    // CHECK: call i32 @_ZN6test333fooINS_1BEEENS_1AIT_Xsr1XIS3_EE5valueEE4typeEv()
+  }
+}