Force a load when creating a reference to a temporary copied from a bitfield.
For this source:
const int &ref = someStruct.bitfield;
We used to generate this AST:
DeclStmt [...]
`-VarDecl [...] ref 'const int &'
`-MaterializeTemporaryExpr [...] 'const int' lvalue
`-ImplicitCastExpr [...] 'const int' lvalue <NoOp>
`-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
`-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'
Notice the lvalue inside the MaterializeTemporaryExpr, which is very
confusing (and caused an assertion to fire in the analyzer - PR15694).
We now generate this:
DeclStmt [...]
`-VarDecl [...] ref 'const int &'
`-MaterializeTemporaryExpr [...] 'const int' lvalue
`-ImplicitCastExpr [...] 'int' <LValueToRValue>
`-MemberExpr [...] 'int' lvalue bitfield .bitfield [...]
`-DeclRefExpr [...] 'struct X' lvalue ParmVar [...] 'someStruct' 'struct X'
Which makes a lot more sense. This allows us to remove code in both
CodeGen and AST that hacked around this special case.
The commit also makes Clang accept this (legal) C++11 code:
int &&ref = std::move(someStruct).bitfield
PR15694 / <rdar://problem/13600396>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179250 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index ae86150..d7abe30 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -2865,25 +2865,12 @@
bool LValueExprEvaluator::VisitMaterializeTemporaryExpr(
const MaterializeTemporaryExpr *E) {
- if (E->GetTemporaryExpr()->isRValue()) {
- if (E->getType()->isRecordType())
- return EvaluateTemporary(E->GetTemporaryExpr(), Result, Info);
+ if (E->getType()->isRecordType())
+ return EvaluateTemporary(E->GetTemporaryExpr(), Result, Info);
- Result.set(E, Info.CurrentCall->Index);
- return EvaluateInPlace(Info.CurrentCall->Temporaries[E], Info,
- Result, E->GetTemporaryExpr());
- }
-
- // Materialization of an lvalue temporary occurs when we need to force a copy
- // (for instance, if it's a bitfield).
- // FIXME: The AST should contain an lvalue-to-rvalue node for such cases.
- if (!Visit(E->GetTemporaryExpr()))
- return false;
- if (!HandleLValueToRValueConversion(Info, E, E->getType(), Result,
- Info.CurrentCall->Temporaries[E]))
- return false;
Result.set(E, Info.CurrentCall->Index);
- return true;
+ return EvaluateInPlace(Info.CurrentCall->Temporaries[E], Info,
+ Result, E->GetTemporaryExpr());
}
bool