Implement final resolution of DR1402: implicitly-declared move operators that

would be deleted are still declared, but are ignored by overload resolution.

Also, don't delete such members if a subobject has no corresponding move
operation and a non-trivial copy. This causes us to implicitly declare move
operations in more cases, but risks move-assigning virtual bases multiple
times in some circumstances (a warning for that is to follow).

llvm-svn: 193969

1 files changed, 16 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index c6bcf449b77..c0bd2229472 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -5448,10 +5448,18 @@ Sema::AddOverloadCandidate(FunctionDecl *Function,
   if (!CandidateSet.isNewCandidate(Function))
     return;
 
+  // C++11 [class.copy]p11: [DR1402]
+  //   A defaulted move constructor that is defined as deleted is ignored by
+  //   overload resolution.
+  CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function);
+  if (Constructor && Constructor->isDefaulted() && Constructor->isDeleted() &&
+      Constructor->isMoveConstructor())
+    return;
+
   // Overload resolution is always an unevaluated context.
   EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);
 
-  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){
+  if (Constructor) {
     // C++ [class.copy]p3:
     //   A member function template is never instantiated to perform the copy
     //   of a class object to an object of its class type.
@@ -5626,6 +5634,13 @@ Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl,
   if (!CandidateSet.isNewCandidate(Method))
     return;
 
+  // C++11 [class.copy]p23: [DR1402]
+  //   A defaulted move assignment operator that is defined as deleted is
+  //   ignored by overload resolution.
+  if (Method->isDefaulted() && Method->isDeleted() &&
+      Method->isMoveAssignmentOperator())
+    return;
+
   // Overload resolution is always an unevaluated context.
   EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated);