diff options
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index 95cd4cca4d2..0fbc624389b 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -353,10 +353,11 @@ fn add_unused_functions(cx: &CodegenCx<'_, '_>) { // To be eligible for "unused function" mappings, a definition must: // - Be function-like - // - Not participate directly in codegen + // - Not participate directly in codegen (or have lost all its coverage statements) // - Not have any coverage statements inlined into codegenned functions tcx.def_kind(def_id).is_fn_like() - && !usage.all_mono_items.contains(&def_id) + && (!usage.all_mono_items.contains(&def_id) + || usage.missing_own_coverage.contains(&def_id)) && !usage.used_via_inlining.contains(&def_id) }; @@ -379,6 +380,7 @@ fn add_unused_functions(cx: &CodegenCx<'_, '_>) { struct UsageSets<'tcx> { all_mono_items: &'tcx DefIdSet, used_via_inlining: FxHashSet<DefId>, + missing_own_coverage: FxHashSet<DefId>, } /// Prepare sets of definitions that are relevant to deciding whether something @@ -406,8 +408,13 @@ fn prepare_usage_sets<'tcx>(tcx: TyCtxt<'tcx>) -> UsageSets<'tcx> { // Functions whose coverage statments were found inlined into other functions. let mut used_via_inlining = FxHashSet::default(); + // Functions that were instrumented, but had all of their coverage statements + // removed by later MIR transforms (e.g. UnreachablePropagation). + let mut missing_own_coverage = FxHashSet::default(); + + for (def_id, body) in def_and_mir_for_all_mono_fns { + let mut saw_own_coverage = false; - for (_def_id, body) in def_and_mir_for_all_mono_fns { // Inspect every coverage statement in the function's MIR. for stmt in body .basic_blocks @@ -418,11 +425,18 @@ fn prepare_usage_sets<'tcx>(tcx: TyCtxt<'tcx>) -> UsageSets<'tcx> { if let Some(inlined) = stmt.source_info.scope.inlined_instance(&body.source_scopes) { // This coverage statement was inlined from another function. used_via_inlining.insert(inlined.def_id()); + } else { + // Non-inlined coverage statements belong to the enclosing function. + saw_own_coverage = true; } } + + if !saw_own_coverage && body.function_coverage_info.is_some() { + missing_own_coverage.insert(def_id); + } } - UsageSets { all_mono_items, used_via_inlining } + UsageSets { all_mono_items, used_via_inlining, missing_own_coverage } } fn add_unused_function_coverage<'tcx>( |