Do not consider explicit constructors when performing a copy to a

temporary object. This is blindingly obvious from reading C++
[over.match.ctor]p1, but somehow I'd missed it and it took DR152 to
educate me. Adjust one test that was relying on this non-standard
behavior.

llvm-svn: 101688

clang/lib/Sema/SemaInit.cpp

@@ -3174,7 +3174,8 @@ static Sema::OwningExprResult CopyObject(Sema &S,
     // Only consider copy constructors.
     CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(*Con);
     if (!Constructor || Constructor->isInvalidDecl() ||
-        !Constructor->isCopyConstructor())
+        !Constructor->isCopyConstructor() ||
+        !Constructor->isConvertingConstructor(/*AllowExplicit=*/false))
       continue;
 
     DeclAccessPair FoundDecl

clang/test/SemaCXX/copy-initialization.cpp

@@ -1,18 +1,21 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s 
 class X {
 public:
-  explicit X(const X&);
-  X(int*); // expected-note 2{{candidate constructor}}
-  explicit X(float*);
+  explicit X(const X&); // expected-note {{candidate constructor}}
+  X(int*); // expected-note 3{{candidate constructor}}
+  explicit X(float*); // expected-note {{candidate constructor}}
 };
 
 class Y : public X { };
 
 void f(Y y, int *ip, float *fp) {
   X x1 = y; // expected-error{{no matching constructor for initialization of 'X'}}
-  X x2 = 0;
-  X x3 = ip;
+  X x2 = 0; // expected-error{{no viable constructor copying variable}}
+  X x3 = ip; // expected-error{{no viable constructor copying variable}}
   X x4 = fp; // expected-error{{no viable conversion}}
+  X x2a(0); // expected-error{{call to constructor of 'X' is ambiguous}}
+  X x3a(ip);
+  X x4a(fp);
 }
 
 struct foo {