diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/required_consts.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/required_consts.rs | 22 |
1 files changed, 15 insertions, 7 deletions
diff --git a/compiler/rustc_mir_transform/src/required_consts.rs b/compiler/rustc_mir_transform/src/required_consts.rs index abde6a47e83..f0c63a6648c 100644 --- a/compiler/rustc_mir_transform/src/required_consts.rs +++ b/compiler/rustc_mir_transform/src/required_consts.rs @@ -1,6 +1,6 @@ use rustc_middle::mir::visit::Visitor; use rustc_middle::mir::{Const, ConstOperand, Location}; -use rustc_middle::ty::ConstKind; +use rustc_middle::ty; pub struct RequiredConstsVisitor<'a, 'tcx> { required_consts: &'a mut Vec<ConstOperand<'tcx>>, @@ -14,14 +14,22 @@ impl<'a, 'tcx> RequiredConstsVisitor<'a, 'tcx> { impl<'tcx> Visitor<'tcx> for RequiredConstsVisitor<'_, 'tcx> { fn visit_constant(&mut self, constant: &ConstOperand<'tcx>, _: Location) { - let const_ = constant.const_; - match const_ { + // Only unevaluated consts have to be added to `required_consts` as only those can possibly + // still have latent const-eval errors. + let is_required = match constant.const_ { Const::Ty(c) => match c.kind() { - ConstKind::Param(_) | ConstKind::Error(_) | ConstKind::Value(_) => {} - _ => bug!("only ConstKind::Param/Value should be encountered here, got {:#?}", c), + ty::ConstKind::Value(_) => false, // already a value, cannot error + ty::ConstKind::Param(_) | ty::ConstKind::Error(_) => true, // these are errors or could be replaced by errors + _ => bug!( + "only ConstKind::Param/Value/Error should be encountered here, got {:#?}", + c + ), }, - Const::Unevaluated(..) => self.required_consts.push(*constant), - Const::Val(..) => {} + Const::Unevaluated(..) => true, + Const::Val(..) => false, // already a value, cannot error + }; + if is_required { + self.required_consts.push(*constant); } } } |
