From 8ff338bfd8abd9ac5d0c1d89c1b05e2c02727174 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Fri, 12 Nov 2010 03:34:06 +0000
Subject: [PATCH] When performing initialization of a copy of a temporary
 object, use direct-initialization (rather than copy-initialization) to
 initialize the temporary, allowing explicit constructors. Fixes PR8342.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@118880 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaInit.cpp                                     | 8 +++++---
 .../dcl.init/dcl.init.ref/p5-cxx03-extra-copy.cpp         | 2 +-
 test/SemaCXX/copy-initialization.cpp                      | 4 ++--
 3 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index ffbb76d8c5..7025369b85 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -3391,14 +3391,16 @@ static ExprResult CopyObject(Sema &S,
   OverloadCandidateSet CandidateSet(Loc);
   for (llvm::tie(Con, ConEnd) = S.LookupConstructors(Class);
        Con != ConEnd; ++Con) {
-    // Only consider copy constructors and constructor templates.
+    // Only consider copy constructors and constructor templates. Per
+    // C++0x [dcl.init]p16, second bullet to class types, this
+    // initialization is direct-initialization.
     CXXConstructorDecl *Constructor = 0;
 
     if ((Constructor = dyn_cast<CXXConstructorDecl>(*Con))) {
       // Handle copy constructors, only.
       if (!Constructor || Constructor->isInvalidDecl() ||
           !Constructor->isCopyConstructor() ||
-          !Constructor->isConvertingConstructor(/*AllowExplicit=*/false))
+          !Constructor->isConvertingConstructor(/*AllowExplicit=*/true))
         continue;
 
       DeclAccessPair FoundDecl
@@ -3415,7 +3417,7 @@ static ExprResult CopyObject(Sema &S,
 
     Constructor = cast<CXXConstructorDecl>(
                                          ConstructorTmpl->getTemplatedDecl());
-    if (!Constructor->isConvertingConstructor(/*AllowExplicit=*/false))
+    if (!Constructor->isConvertingConstructor(/*AllowExplicit=*/true))
       continue;
 
     // FIXME: Do we need to limit this to copy-constructor-like
diff --git a/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-cxx03-extra-copy.cpp b/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-cxx03-extra-copy.cpp
index ae59598f69..8c654110fa 100644
--- a/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-cxx03-extra-copy.cpp
+++ b/test/CXX/dcl.decl/dcl.init/dcl.init.ref/p5-cxx03-extra-copy.cpp
@@ -53,7 +53,7 @@ void g4(const X4<int>&);
 void g5(const X5&);
 
 void test() {
-  g1(X1()); // expected-warning{{no viable constructor copying parameter of type 'X1'; C++98 requires a copy constructor when binding a reference to a temporary [-Wbind-to-temporary-copy]}}
+  g1(X1());
   g2(X2()); // expected-warning{{C++98 requires an accessible copy constructor for class 'X2' when binding a reference to a temporary; was private [-Wbind-to-temporary-copy]}}
   g3(X3()); // expected-warning{{no viable constructor copying parameter of type 'X3'}}
   g4(X4<int>());
diff --git a/test/SemaCXX/copy-initialization.cpp b/test/SemaCXX/copy-initialization.cpp
index 641eaa9411..a28a1941ec 100644
--- a/test/SemaCXX/copy-initialization.cpp
+++ b/test/SemaCXX/copy-initialization.cpp
@@ -10,8 +10,8 @@ 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; // expected-error{{no viable constructor copying variable}}
-  X x3 = ip; // expected-error{{no viable constructor copying variable}}
+  X x2 = 0;
+  X x3 = ip;
   X x4 = fp; // expected-error{{no viable conversion}}
   X x2a(0); // expected-error{{call to constructor of 'X' is ambiguous}}
   X x3a(ip);
-- 
2.40.0