Provide a real fix for PR6199, reverting the old workaround. Here, we

realize that CXXConstructExpr is always implicit, so we should just
return its argument (if there is only one) rather than directly
invoking the constructor.

llvm-svn: 95192

2 files changed, 7 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp
index 8dd747240aa..4253d18c390 100644
--- a/clang/lib/CodeGen/CGExprCXX.cpp
+++ b/clang/lib/CodeGen/CGExprCXX.cpp
@@ -309,9 +309,7 @@ CodeGenFunction::EmitCXXConstructExpr(llvm::Value *Dest,
   if (getContext().getLangOptions().ElideConstructors && E->isElidable()) {
     const Expr *Arg = E->getArg(0);
     
-    // FIXME: This 'while' statement should really be an 'if' statement, it's 
-    // added as a workaround for PR6199.
-    while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
+    if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
       assert((ICE->getCastKind() == CastExpr::CK_NoOp ||
               ICE->getCastKind() == CastExpr::CK_ConstructorConversion ||
               ICE->getCastKind() == CastExpr::CK_UserDefinedConversion) &&
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 1938e3dfb59..b1b85e5928a 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -4808,6 +4808,12 @@ TreeTransform<Derived>::TransformDependentScopeDeclRefExpr(
 template<typename Derived>
 Sema::OwningExprResult
 TreeTransform<Derived>::TransformCXXConstructExpr(CXXConstructExpr *E) {
+  // CXXConstructExprs are always implicit, so when we have a
+  // 1-argument construction we just transform that argument.
+  if (E->getNumArgs() == 1 ||
+      (E->getNumArgs() > 1 && getDerived().DropCallArgument(E->getArg(1))))
+    return getDerived().TransformExpr(E->getArg(0));
+
   TemporaryBase Rebase(*this, /*FIXME*/E->getLocStart(), DeclarationName());
 
   QualType T = getDerived().TransformType(E->getType());