If we attempt to add a constructor template specialization that looks

like a copy constructor to the overload set, just ignore it. This
ensures that we don't try to use such a constructor as a copy
constructor *without* triggering diagnostics at the point of
declaration.

Note that we *do* diagnose such copy constructors when explicitly
written by the user (e.g., as an explicit specialization).



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@88733 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 2 deletions

diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 3948b22f7b..53e64dfc68 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -1422,7 +1422,7 @@ Sema::OverloadingResult Sema::IsUserDefinedConversion(
             = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl());
         else
           Constructor = cast<CXXConstructorDecl>(*Con);
-
+        
         if (!Constructor->isInvalidDecl() &&
             Constructor->isConvertingConstructor(AllowExplicit)) {
           if (ConstructorTmpl)
@@ -2239,7 +2239,18 @@ Sema::AddOverloadCandidate(FunctionDecl *Function,
 
   if (!CandidateSet.isNewCandidate(Function))
     return;
-    
+
+  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){
+    // 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.
+    QualType ClassType = Context.getTypeDeclType(Constructor->getParent());
+    if (NumArgs == 1 && 
+        Constructor->isCopyConstructorLikeSpecialization() &&
+        Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()))
+      return;
+  }
+  
   // Add this candidate
   CandidateSet.push_back(OverloadCandidate());
   OverloadCandidate& Candidate = CandidateSet.back();