diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/coverage/mod.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/coverage/mod.rs | 294 |
1 files changed, 13 insertions, 281 deletions
diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs index f253d1662ca..c5fef299244 100644 --- a/compiler/rustc_mir_transform/src/coverage/mod.rs +++ b/compiler/rustc_mir_transform/src/coverage/mod.rs @@ -1,5 +1,15 @@ +use rustc_middle::mir::coverage::{CoverageKind, FunctionCoverageInfo}; +use rustc_middle::mir::{self, BasicBlock, Statement, StatementKind, TerminatorKind}; +use rustc_middle::ty::TyCtxt; +use tracing::{debug, debug_span, trace}; + +use crate::coverage::counters::BcbCountersData; +use crate::coverage::graph::CoverageGraph; +use crate::coverage::mappings::ExtractedMappings; + mod counters; mod graph; +mod hir_info; mod mappings; pub(super) mod query; mod spans; @@ -7,22 +17,6 @@ mod spans; mod tests; mod unexpand; -use rustc_hir as hir; -use rustc_hir::intravisit::{Visitor, walk_expr}; -use rustc_middle::hir::nested_filter; -use rustc_middle::mir::coverage::{ - CoverageKind, DecisionInfo, FunctionCoverageInfo, Mapping, MappingKind, -}; -use rustc_middle::mir::{self, BasicBlock, Statement, StatementKind, TerminatorKind}; -use rustc_middle::ty::TyCtxt; -use rustc_span::Span; -use rustc_span::def_id::LocalDefId; -use tracing::{debug, debug_span, trace}; - -use crate::coverage::counters::BcbCountersData; -use crate::coverage::graph::CoverageGraph; -use crate::coverage::mappings::ExtractedMappings; - /// Inserts `StatementKind::Coverage` statements that either instrument the binary with injected /// counters, via intrinsic `llvm.instrprof.increment`, and/or inject metadata used during codegen /// to construct the coverage map. @@ -69,7 +63,7 @@ fn instrument_function_for_coverage<'tcx>(tcx: TyCtxt<'tcx>, mir_body: &mut mir: let def_id = mir_body.source.def_id(); let _span = debug_span!("instrument_function_for_coverage", ?def_id).entered(); - let hir_info = extract_hir_info(tcx, def_id.expect_local()); + let hir_info = hir_info::extract_hir_info(tcx, def_id.expect_local()); // Build the coverage graph, which is a simplified view of the MIR control-flow // graph that ignores some details not relevant to coverage instrumentation. @@ -77,10 +71,8 @@ fn instrument_function_for_coverage<'tcx>(tcx: TyCtxt<'tcx>, mir_body: &mut mir: //////////////////////////////////////////////////// // Extract coverage spans and other mapping info from MIR. - let extracted_mappings = - mappings::extract_all_mapping_info_from_mir(tcx, mir_body, &hir_info, &graph); - - let mappings = create_mappings(&extracted_mappings); + let ExtractedMappings { mappings } = + mappings::extract_mappings_from_mir(tcx, mir_body, &hir_info, &graph); if mappings.is_empty() { // No spans could be converted into valid mappings, so skip this function. debug!("no spans could be converted into valid mappings; skipping"); @@ -95,14 +87,6 @@ fn instrument_function_for_coverage<'tcx>(tcx: TyCtxt<'tcx>, mir_body: &mut mir: // Inject coverage statements into MIR. inject_coverage_statements(mir_body, &graph); - inject_mcdc_statements(mir_body, &graph, &extracted_mappings); - - let mcdc_num_condition_bitmaps = extracted_mappings - .mcdc_mappings - .iter() - .map(|&(mappings::MCDCDecision { decision_depth, .. }, _)| decision_depth) - .max() - .map_or(0, |max| usize::from(max) + 1); mir_body.function_coverage_info = Some(Box::new(FunctionCoverageInfo { function_source_hash: hir_info.function_source_hash, @@ -111,97 +95,9 @@ fn instrument_function_for_coverage<'tcx>(tcx: TyCtxt<'tcx>, mir_body: &mut mir: priority_list, mappings, - - mcdc_bitmap_bits: extracted_mappings.mcdc_bitmap_bits, - mcdc_num_condition_bitmaps, })); } -/// For each coverage span extracted from MIR, create a corresponding mapping. -/// -/// FIXME(Zalathar): This used to be where BCBs in the extracted mappings were -/// resolved to a `CovTerm`. But that is now handled elsewhere, so this -/// function can potentially be simplified even further. -fn create_mappings(extracted_mappings: &ExtractedMappings) -> Vec<Mapping> { - // Fully destructure the mappings struct to make sure we don't miss any kinds. - let ExtractedMappings { - code_mappings, - branch_pairs, - mcdc_bitmap_bits: _, - mcdc_degraded_branches, - mcdc_mappings, - } = extracted_mappings; - let mut mappings = Vec::new(); - - mappings.extend(code_mappings.iter().map( - // Ordinary code mappings are the simplest kind. - |&mappings::CodeMapping { span, bcb }| { - let kind = MappingKind::Code { bcb }; - Mapping { kind, span } - }, - )); - - mappings.extend(branch_pairs.iter().map( - |&mappings::BranchPair { span, true_bcb, false_bcb }| { - let kind = MappingKind::Branch { true_bcb, false_bcb }; - Mapping { kind, span } - }, - )); - - // MCDC branch mappings are appended with their decisions in case decisions were ignored. - mappings.extend(mcdc_degraded_branches.iter().map( - |&mappings::MCDCBranch { - span, - true_bcb, - false_bcb, - condition_info: _, - true_index: _, - false_index: _, - }| { Mapping { kind: MappingKind::Branch { true_bcb, false_bcb }, span } }, - )); - - for (decision, branches) in mcdc_mappings { - // 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( - |&mappings::MCDCBranch { - span, - true_bcb, - false_bcb, - condition_info, - true_index: _, - false_index: _, - }| { - Mapping { - kind: MappingKind::MCDCBranch { - true_bcb, - false_bcb, - mcdc_params: condition_info, - }, - span, - } - }, - ) - .collect::<Vec<_>>(); - - // 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 -} - /// Inject any necessary coverage statements into MIR, so that they influence codegen. fn inject_coverage_statements<'tcx>(mir_body: &mut mir::Body<'tcx>, graph: &CoverageGraph) { for (bcb, data) in graph.iter_enumerated() { @@ -210,51 +106,6 @@ fn inject_coverage_statements<'tcx>(mir_body: &mut mir::Body<'tcx>, graph: &Cove } } -/// For each conditions inject statements to update condition bitmap after it has been evaluated. -/// For each decision inject statements to update test vector bitmap after it has been evaluated. -fn inject_mcdc_statements<'tcx>( - mir_body: &mut mir::Body<'tcx>, - graph: &CoverageGraph, - extracted_mappings: &ExtractedMappings, -) { - for (decision, conditions) in &extracted_mappings.mcdc_mappings { - // Inject test vector update first because `inject_statement` always insert new statement at head. - for &end in &decision.end_bcbs { - let end_bb = graph[end].leader_bb(); - inject_statement( - mir_body, - CoverageKind::TestVectorBitmapUpdate { - bitmap_idx: decision.bitmap_idx as u32, - decision_depth: decision.decision_depth, - }, - end_bb, - ); - } - - for &mappings::MCDCBranch { - span: _, - true_bcb, - false_bcb, - condition_info: _, - true_index, - false_index, - } in conditions - { - for (index, bcb) in [(false_index, false_bcb), (true_index, true_bcb)] { - let bb = graph[bcb].leader_bb(); - inject_statement( - mir_body, - CoverageKind::CondBitmapUpdate { - index: index as u32, - decision_depth: decision.decision_depth, - }, - bb, - ); - } - } - } -} - fn inject_statement(mir_body: &mut mir::Body<'_>, counter_kind: CoverageKind, bb: BasicBlock) { debug!(" injecting statement {counter_kind:?} for {bb:?}"); let data = &mut mir_body[bb]; @@ -262,122 +113,3 @@ fn inject_statement(mir_body: &mut mir::Body<'_>, counter_kind: CoverageKind, bb let statement = Statement::new(source_info, StatementKind::Coverage(counter_kind)); data.statements.insert(0, statement); } - -/// Function information extracted from HIR by the coverage instrumentor. -#[derive(Debug)] -struct ExtractedHirInfo { - function_source_hash: u64, - is_async_fn: bool, - /// The span of the function's signature, if available. - /// Must have the same context and filename as the body span. - fn_sig_span: Option<Span>, - body_span: Span, - /// "Holes" are regions within the function body (or its expansions) that - /// should not be included in coverage spans for this function - /// (e.g. closures and nested items). - hole_spans: Vec<Span>, -} - -fn extract_hir_info<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> ExtractedHirInfo { - // FIXME(#79625): Consider improving MIR to provide the information needed, to avoid going back - // to HIR for it. - - // HACK: For synthetic MIR bodies (async closures), use the def id of the HIR body. - if tcx.is_synthetic_mir(def_id) { - return extract_hir_info(tcx, tcx.local_parent(def_id)); - } - - let hir_node = tcx.hir_node_by_def_id(def_id); - let fn_body_id = hir_node.body_id().expect("HIR node is a function with body"); - let hir_body = tcx.hir_body(fn_body_id); - - let maybe_fn_sig = hir_node.fn_sig(); - let is_async_fn = maybe_fn_sig.is_some_and(|fn_sig| fn_sig.header.is_async()); - - let mut body_span = hir_body.value.span; - - use hir::{Closure, Expr, ExprKind, Node}; - // Unexpand a closure's body span back to the context of its declaration. - // This helps with closure bodies that consist of just a single bang-macro, - // and also with closure bodies produced by async desugaring. - if let Node::Expr(&Expr { kind: ExprKind::Closure(&Closure { fn_decl_span, .. }), .. }) = - hir_node - { - body_span = body_span.find_ancestor_in_same_ctxt(fn_decl_span).unwrap_or(body_span); - } - - // The actual signature span is only used if it has the same context and - // filename as the body, and precedes the body. - let fn_sig_span = maybe_fn_sig.map(|fn_sig| fn_sig.span).filter(|&fn_sig_span| { - let source_map = tcx.sess.source_map(); - let file_idx = |span: Span| source_map.lookup_source_file_idx(span.lo()); - - fn_sig_span.eq_ctxt(body_span) - && fn_sig_span.hi() <= body_span.lo() - && file_idx(fn_sig_span) == file_idx(body_span) - }); - - let function_source_hash = hash_mir_source(tcx, hir_body); - - let hole_spans = extract_hole_spans_from_hir(tcx, hir_body); - - ExtractedHirInfo { function_source_hash, is_async_fn, fn_sig_span, body_span, hole_spans } -} - -fn hash_mir_source<'tcx>(tcx: TyCtxt<'tcx>, hir_body: &'tcx hir::Body<'tcx>) -> u64 { - // FIXME(cjgillot) Stop hashing HIR manually here. - let owner = hir_body.id().hir_id.owner; - tcx.hir_owner_nodes(owner).opt_hash_including_bodies.unwrap().to_smaller_hash().as_u64() -} - -fn extract_hole_spans_from_hir<'tcx>(tcx: TyCtxt<'tcx>, hir_body: &hir::Body<'tcx>) -> Vec<Span> { - struct HolesVisitor<'tcx> { - tcx: TyCtxt<'tcx>, - hole_spans: Vec<Span>, - } - - impl<'tcx> Visitor<'tcx> for HolesVisitor<'tcx> { - /// We have special handling for nested items, but we still want to - /// traverse into nested bodies of things that are not considered items, - /// such as "anon consts" (e.g. array lengths). - type NestedFilter = nested_filter::OnlyBodies; - - fn maybe_tcx(&mut self) -> TyCtxt<'tcx> { - self.tcx - } - - /// We override `visit_nested_item` instead of `visit_item` because we - /// only need the item's span, not the item itself. - fn visit_nested_item(&mut self, id: hir::ItemId) -> Self::Result { - let span = self.tcx.def_span(id.owner_id.def_id); - self.visit_hole_span(span); - // Having visited this item, we don't care about its children, - // so don't call `walk_item`. - } - - // We override `visit_expr` instead of the more specific expression - // visitors, so that we have direct access to the expression span. - fn visit_expr(&mut self, expr: &'tcx hir::Expr<'tcx>) { - match expr.kind { - hir::ExprKind::Closure(_) | hir::ExprKind::ConstBlock(_) => { - self.visit_hole_span(expr.span); - // Having visited this expression, we don't care about its - // children, so don't call `walk_expr`. - } - - // For other expressions, recursively visit as normal. - _ => walk_expr(self, expr), - } - } - } - impl HolesVisitor<'_> { - fn visit_hole_span(&mut self, hole_span: Span) { - self.hole_spans.push(hole_span); - } - } - - let mut visitor = HolesVisitor { tcx, hole_spans: vec![] }; - - visitor.visit_body(hir_body); - visitor.hole_spans -} |