From fabf95d0667b5dcc9da3d5537f1d3ca20b2914b5 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 30 Apr 2010 21:46:38 +0000
Subject: After substituting a template argument for a non-type template
 parameter with pointer-to-member type, we may have to perform a qualification
 conversion, since the pointee type of the parameter might be more qualified
 than the pointee type of the argument we form from the declaration. Fixes
 PR6986.

llvm-svn: 102777
---
 clang/lib/Sema/SemaTemplate.cpp                    | 14 ++++++++++++-
 .../instantiate-non-type-template-parameter.cpp    | 24 +++++++++++++++++++++-
 2 files changed, 36 insertions(+), 2 deletions(-)

(limited to 'clang')

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index db9ed7e1efc..56410a2cfa4 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -3061,9 +3061,21 @@ Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
         return ExprError();
       
       RefExpr = CreateBuiltinUnaryOp(Loc, UnaryOperator::AddrOf, move(RefExpr));
+      
+      // We might need to perform a trailing qualification conversion, since
+      // the element type on the parameter could be more qualified than the
+      // element type in the expression we constructed.
+      if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
+                                    ParamType.getUnqualifiedType())) {
+        Expr *RefE = RefExpr.takeAs<Expr>();
+        ImpCastExprToType(RefE, ParamType.getUnqualifiedType(),
+                          CastExpr::CK_NoOp);
+        RefExpr = Owned(RefE);
+      }
+      
       assert(!RefExpr.isInvalid() &&
              Context.hasSameType(((Expr*) RefExpr.get())->getType(),
-                                 ParamType));
+                                 ParamType.getUnqualifiedType()));
       return move(RefExpr);
     }
   }
diff --git a/clang/test/SemaTemplate/instantiate-non-type-template-parameter.cpp b/clang/test/SemaTemplate/instantiate-non-type-template-parameter.cpp
index 414e62b13a0..cbadcde2c1c 100644
--- a/clang/test/SemaTemplate/instantiate-non-type-template-parameter.cpp
+++ b/clang/test/SemaTemplate/instantiate-non-type-template-parameter.cpp
@@ -9,6 +9,28 @@ public:
   }
 };
 
-int main(int argc, char *argv[]) {
+void test_stringswitch(int argc, char *argv[]) {
   (void)StringSwitch<int>();
 }
+
+namespace PR6986 {
+  template<class Class,typename Type,Type Class::*> 
+  struct non_const_member_base
+  {
+  };
+
+  template<class Class,typename Type,Type Class::*PtrToMember> 
+  struct member: non_const_member_base<Class,Type,PtrToMember>
+  {
+  };
+
+  struct test_class
+  {
+    int int_member;
+  };
+  typedef member< test_class,const int,&test_class::int_member > ckey_m;
+  void test()
+  {
+    ckey_m m;
+  }
+}
-- 
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