From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Tue, 15 May 2012 05:04:02 +0000 (+0000)
Subject: PR12826: Converting an lvalue to an xvalue is a no-op conversion, not an lvalue-to... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=dbbecccb8431bb4545fc01c6401abc4253667360;p=clang

PR12826: Converting an lvalue to an xvalue is a no-op conversion, not an lvalue-to-rvalue conversion.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156803 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaStmt.cpp b/lib/Sema/SemaStmt.cpp
index 2e1cc7c600..2ea07efde8 100644
--- a/lib/Sema/SemaStmt.cpp
+++ b/lib/Sema/SemaStmt.cpp
@@ -2033,8 +2033,7 @@ Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
   if (AllowNRVO &&
       (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) {
     ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack,
-                              Value->getType(), CK_LValueToRValue,
-                              Value, VK_XValue);
+                              Value->getType(), CK_NoOp, Value, VK_XValue);
 
     Expr *InitExpr = &AsRvalue;
     InitializationKind Kind
@@ -2069,8 +2068,7 @@ Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity,
         // Promote "AsRvalue" to the heap, since we now need this
         // expression node to persist.
         Value = ImplicitCastExpr::Create(Context, Value->getType(),
-                                         CK_LValueToRValue, Value, 0,
-                                         VK_XValue);
+                                         CK_NoOp, Value, 0, VK_XValue);
 
         // Complete type-checking the initialization of the return type
         // using the constructor we found.
diff --git a/test/SemaCXX/constant-expression-cxx11.cpp b/test/SemaCXX/constant-expression-cxx11.cpp
index a9e1008ec6..263e8411b4 100644
--- a/test/SemaCXX/constant-expression-cxx11.cpp
+++ b/test/SemaCXX/constant-expression-cxx11.cpp
@@ -1258,3 +1258,11 @@ namespace InvalidClasses {
     auto& b = y.b;
   }
 }
+
+// Indirectly test that an implicit lvalue to xvalue conversion performed for
+// an NRVO move operation isn't implemented as CK_LValueToRValue.
+namespace PR12826 {
+  struct Foo {};
+  constexpr Foo id(Foo x) { return x; }
+  constexpr Foo res(id(Foo()));
+}