Although we currently have explicit lvalue-to-rvalue conversions, they're
not actually frequently used, because ImpCastExprToType only creates a node
if the types differ.  So explicitly create an ICE in the lvalue-to-rvalue
conversion code in DefaultFunctionArrayLvalueConversion() as well as several
other new places, and consistently deal with the consequences throughout the
compiler.

In addition, introduce a new cast kind for loading an ObjCProperty l-value,
and make sure we emit those nodes whenever an ObjCProperty l-value appears
that's not on the LHS of an assignment operator.

This breaks a couple of rewriter tests, which I've x-failed until future
development occurs on the rewriter.

Ted Kremenek kindly contributed the analyzer workarounds in this patch.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@120890 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 9e4e7dc..b2679a3 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -282,8 +282,16 @@
     break;
   }
 
+  case CK_GetObjCProperty: {
+    LValue LV = CGF.EmitLValue(E->getSubExpr());
+    assert(LV.isPropertyRef());
+    RValue RV = CGF.EmitLoadOfPropertyRefLValue(LV, getReturnValueSlot());
+    EmitGCMove(E, RV);
+    break;
+  }
+
+  case CK_LValueToRValue: // hope for downstream optimization
   case CK_NoOp:
-  case CK_LValueToRValue:
   case CK_UserDefinedConversion:
   case CK_ConstructorConversion:
     assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),
@@ -349,9 +357,8 @@
 }
 
 void AggExprEmitter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
-  RValue RV = CGF.EmitLoadOfPropertyRefLValue(CGF.EmitObjCPropertyRefLValue(E),
-                                              getReturnValueSlot());
-  EmitGCMove(E, RV);
+  llvm_unreachable("direct property access not surrounded by "
+                   "lvalue-to-rvalue cast");
 }
 
 void AggExprEmitter::VisitBinComma(const BinaryOperator *E) {