diff options
Diffstat (limited to 'compiler/rustc_mir_transform')
| -rw-r--r-- | compiler/rustc_mir_transform/src/inline.rs | 19 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/required_consts.rs | 22 |
2 files changed, 20 insertions, 21 deletions
diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs index 7dcff458ced..b21bbc98f73 100644 --- a/compiler/rustc_mir_transform/src/inline.rs +++ b/compiler/rustc_mir_transform/src/inline.rs @@ -720,18 +720,8 @@ impl<'tcx> Inliner<'tcx> { kind: TerminatorKind::Goto { target: integrator.map_block(START_BLOCK) }, }); - // Copy only unevaluated constants from the callee_body into the caller_body. - // Although we are only pushing `ConstKind::Unevaluated` consts to - // `required_consts`, here we may not only have `ConstKind::Unevaluated` - // because we are calling `instantiate_and_normalize_erasing_regions`. - caller_body.required_consts.extend(callee_body.required_consts.iter().copied().filter( - |&ct| match ct.const_ { - Const::Ty(_) => { - bug!("should never encounter ty::UnevaluatedConst in `required_consts`") - } - Const::Val(..) | Const::Unevaluated(..) => true, - }, - )); + // Copy required constants from the callee_body into the caller_body. + caller_body.required_consts.extend(callee_body.required_consts); // Now that we incorporated the callee's `required_consts`, we can remove the callee from // `mentioned_items` -- but we have to take their `mentioned_items` in return. This does // some extra work here to save the monomorphization collector work later. It helps a lot, @@ -747,8 +737,9 @@ impl<'tcx> Inliner<'tcx> { caller_body.mentioned_items.remove(idx); caller_body.mentioned_items.extend(callee_body.mentioned_items); } else { - // If we can't find the callee, there's no point in adding its items. - // Probably it already got removed by being inlined elsewhere in the same function. + // If we can't find the callee, there's no point in adding its items. Probably it + // already got removed by being inlined elsewhere in the same function, so we already + // took its items. } } 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); } } } |