diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/coverage/mod.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/coverage/mod.rs | 32 |
1 files changed, 13 insertions, 19 deletions
diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs index 19568735df7..b8aa76a7dbe 100644 --- a/compiler/rustc_mir_transform/src/coverage/mod.rs +++ b/compiler/rustc_mir_transform/src/coverage/mod.rs @@ -180,7 +180,12 @@ fn create_mappings( )); for (decision, branches) in mcdc_mappings { - let num_conditions = branches.len() as u16; + // FIXME(#134497): Previously it was possible for some of these branch + // conversions to fail, in which case the remaining branches in the + // decision would be degraded to plain `MappingKind::Branch`. + // The changes in #134497 made that failure impossible, because the + // fallible step was deferred to codegen. But the corresponding code + // in codegen wasn't updated to detect the need for a degrade step. let conditions = branches .into_iter() .map( @@ -206,24 +211,13 @@ fn create_mappings( ) .collect::<Vec<_>>(); - if conditions.len() == num_conditions as usize { - // LLVM requires end index for counter mapping regions. - let kind = MappingKind::MCDCDecision(DecisionInfo { - bitmap_idx: (decision.bitmap_idx + decision.num_test_vectors) as u32, - num_conditions, - }); - let span = decision.span; - mappings.extend(std::iter::once(Mapping { kind, span }).chain(conditions.into_iter())); - } else { - mappings.extend(conditions.into_iter().map(|mapping| { - let MappingKind::MCDCBranch { true_term, false_term, mcdc_params: _ } = - mapping.kind - else { - unreachable!("all mappings here are MCDCBranch as shown above"); - }; - Mapping { kind: MappingKind::Branch { true_term, false_term }, span: mapping.span } - })) - } + // LLVM requires end index for counter mapping regions. + let kind = MappingKind::MCDCDecision(DecisionInfo { + bitmap_idx: (decision.bitmap_idx + decision.num_test_vectors) as u32, + num_conditions: u16::try_from(conditions.len()).unwrap(), + }); + let span = decision.span; + mappings.extend(std::iter::once(Mapping { kind, span }).chain(conditions.into_iter())); } mappings |