Restore the lvalue-to-rvalue conversion patch with a minimal fix.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@120555 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 44 insertions, 6 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index ce25b7ff25..466f55f341 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -1789,8 +1789,7 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
     llvm_unreachable("dependent cast kind in IR gen!");
 
   case CK_NoOp:
-    if (E->getSubExpr()->Classify(getContext()).getKind() 
-                                          != Expr::Classification::CL_PRValue) {
+    if (!E->getSubExpr()->isRValue() || E->getType()->isRecordType()) {
       LValue LV = EmitLValue(E->getSubExpr());
       if (LV.isPropertyRef() || LV.isKVCRef()) {
         QualType QT = E->getSubExpr()->getType();
@@ -1805,6 +1804,7 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
     }
     // Fall through to synthesize a temporary.
 
+  case CK_LValueToRValue:
   case CK_BitCast:
   case CK_ArrayToPointerDecay:
   case CK_FunctionToPointerDecay:
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 308520aadd..bd1c43dff5 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -250,8 +250,6 @@ void AggExprEmitter::VisitCastExpr(CastExpr *E) {
   }
 
   switch (E->getCastKind()) {
-  default: assert(0 && "Unhandled cast kind!");
-
   case CK_Dynamic: {
     assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?");
     LValue LV = CGF.EmitCheckedLValue(E->getSubExpr());
@@ -286,6 +284,7 @@ void AggExprEmitter::VisitCastExpr(CastExpr *E) {
   }
 
   case CK_NoOp:
+  case CK_LValueToRValue:
   case CK_UserDefinedConversion:
   case CK_ConstructorConversion:
     assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
@@ -293,10 +292,45 @@ void AggExprEmitter::VisitCastExpr(CastExpr *E) {
            "Implicit cast types must be compatible");
     Visit(E->getSubExpr());
     break;
-
+      
   case CK_LValueBitCast:
-    llvm_unreachable("there are no lvalue bit-casts on aggregates");
+    llvm_unreachable("should not be emitting lvalue bitcast as rvalue");
     break;
+      
+  case CK_Dependent:
+  case CK_BitCast:
+  case CK_ArrayToPointerDecay:
+  case CK_FunctionToPointerDecay:
+  case CK_NullToPointer:
+  case CK_NullToMemberPointer:
+  case CK_BaseToDerivedMemberPointer:
+  case CK_DerivedToBaseMemberPointer:
+  case CK_MemberPointerToBoolean:
+  case CK_IntegralToPointer:
+  case CK_PointerToIntegral:
+  case CK_PointerToBoolean:
+  case CK_ToVoid:
+  case CK_VectorSplat:
+  case CK_IntegralCast:
+  case CK_IntegralToBoolean:
+  case CK_IntegralToFloating:
+  case CK_FloatingToIntegral:
+  case CK_FloatingToBoolean:
+  case CK_FloatingCast:
+  case CK_AnyPointerToObjCPointerCast:
+  case CK_AnyPointerToBlockPointerCast:
+  case CK_ObjCObjectLValueCast:
+  case CK_FloatingRealToComplex:
+  case CK_FloatingComplexToReal:
+  case CK_FloatingComplexToBoolean:
+  case CK_FloatingComplexCast:
+  case CK_FloatingComplexToIntegralComplex:
+  case CK_IntegralRealToComplex:
+  case CK_IntegralComplexToReal:
+  case CK_IntegralComplexToBoolean:
+  case CK_IntegralComplexCast:
+  case CK_IntegralComplexToFloatingComplex:
+    llvm_unreachable("cast kind invalid for aggregate types");
   }
 }
 
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index e5ea26c24b..a46afe6f65 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -1101,6 +1101,10 @@ Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) {
   case CK_ToUnion:
     llvm_unreachable("scalar cast to non-scalar value");
     break;
+      
+  case CK_LValueToRValue:
+    assert(CGF.getContext().hasSameUnqualifiedType(E->getType(), DestTy));
+    return Visit(const_cast<Expr*>(E));
 
   case CK_IntegralToPointer: {
     Value *Src = Visit(const_cast<Expr*>(E));