diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp index 3ab85686752c..b3cf921bc57e 100644 --- a/clang/lib/CodeGen/CGExpr.cpp +++ b/clang/lib/CodeGen/CGExpr.cpp @@ -179,6 +179,19 @@ LValue CodeGenFunction::EmitLValue(const Expr *E) { return EmitCompoundLiteralLValue(cast(E)); case Expr::ChooseExprClass: return EmitLValue(cast(E)->getChosenSubExpr(getContext())); + case Expr::ImplicitCastExprClass: + case Expr::CStyleCastExprClass: + case Expr::CXXFunctionalCastExprClass: + case Expr::CXXStaticCastExprClass: + case Expr::CXXDynamicCastExprClass: + case Expr::CXXReinterpretCastExprClass: + case Expr::CXXConstCastExprClass: + // Casts are only lvalues when the source and destination types are the + // same. + assert(getContext().hasSameUnqualifiedType(E->getType(), + cast(E)->getSubExpr()->getType()) && + "Type changing cast is not an lvalue"); + return EmitLValue(cast(E)->getSubExpr()); } } diff --git a/clang/test/CodeGen/exprs.c b/clang/test/CodeGen/exprs.c index 81742673c2aa..db60b5a3301d 100644 --- a/clang/test/CodeGen/exprs.c +++ b/clang/test/CodeGen/exprs.c @@ -58,4 +58,12 @@ void f0(void (*fp)(void), void (*fp2)(void)) { int x = fp - fp2; } +// noop casts as lvalues. +struct X { + int Y; +}; +struct X foo(); +int bar() { + return ((struct X)foo()).Y + 1; +}