cor3ntin added inline comments.
================ Comment at: clang/lib/Sema/SemaExprCXX.cpp:4016-4019 + // Ensure that `-Wunused-variable` will be emitted for condition variables + // that are not referenced later. e.g.: if (int var = init()); + if (!T->isAggregateType()) + ConditionVar->setReferenced(/*R=*/false); ---------------- hazohelet wrote: > cor3ntin wrote: > > aaron.ballman wrote: > > > `isAggregateType()` includes arrays and I think we still want to diagnose > > > an unused array. > > Should it not be `Condition->hasSideEffects()` ? > > Hopefully we want to be consistent with existing behavior > > https://godbolt.org/z/6abbPhn4G > The condition here only applies to condition variables. > C++ does not allow array type in condition variable, correct? I think it's OK > to use `isAggregateType` as well then. After a chat with Aaron, I have a few questions: Do we call `Scope::AddDecl` - or `PushOnScopeChains` somewhere? My intuition is that if the condition is added to a scope, and we call ` ConditionVar->setReferenced(false);`, the all the diagnostic mechanism in `DiagnoseUnusedDecl` should be triggered. and it seen to be because we do get a diagnostic. So neither `if (!T->isAggregateType())` or any check should be needed there Can you just remove that if statement (just set `setReferenced(false)`) and see if it works? Otherwise, i think we need to understand why it doesn't but trying to reimplement the logic of `ShouldDiagnoseUnusedDecl`seems fraught with unbounded complexity. CHANGES SINCE LAST ACTION https://reviews.llvm.org/D152495/new/ https://reviews.llvm.org/D152495 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
