diff --git a/compiler/rustc_mir_transform/src/coverage/mappings.rs b/compiler/rustc_mir_transform/src/coverage/mappings.rs new file mode 100644 index 0000000000000..d364658efb6d6 --- /dev/null +++ b/compiler/rustc_mir_transform/src/coverage/mappings.rs @@ -0,0 +1,275 @@ +use std::collections::BTreeSet; + +use rustc_data_structures::graph::DirectedGraph; +use rustc_index::bit_set::BitSet; +use rustc_middle::mir::coverage::{ + BlockMarkerId, BranchSpan, ConditionInfo, CoverageKind, MCDCBranchSpan, MCDCDecisionSpan, +}; +use rustc_middle::mir::{self, BasicBlock, StatementKind}; +use rustc_span::Span; + +use crate::coverage::graph::{BasicCoverageBlock, CoverageGraph, START_BCB}; +use crate::coverage::spans::{ + extract_refined_covspans, unexpand_into_body_span_with_visible_macro, +}; +use crate::coverage::ExtractedHirInfo; +use rustc_index::IndexVec; + +#[derive(Clone, Debug)] +pub(super) enum BcbMappingKind { + /// Associates an ordinary executable code span with its corresponding BCB. + Code(BasicCoverageBlock), + + // Ordinary branch mappings are stored separately, so they don't have a + // variant in this enum. + // + /// Associates a mcdc branch span with condition info besides fields for normal branch. + MCDCBranch { + true_bcb: BasicCoverageBlock, + false_bcb: BasicCoverageBlock, + /// If `None`, this actually represents a normal branch mapping inserted + /// for code that was too complex for MC/DC. + condition_info: Option, + decision_depth: u16, + }, + /// Associates a mcdc decision with its join BCB. + MCDCDecision { + end_bcbs: BTreeSet, + bitmap_idx: u32, + conditions_num: u16, + decision_depth: u16, + }, +} + +#[derive(Debug)] +pub(super) struct BcbMapping { + pub(super) kind: BcbMappingKind, + pub(super) span: Span, +} + +/// This is separate from [`BcbMappingKind`] to help prepare for larger changes +/// that will be needed for improved branch coverage in the future. +/// (See .) +#[derive(Debug)] +pub(super) struct BcbBranchPair { + pub(super) span: Span, + pub(super) true_bcb: BasicCoverageBlock, + pub(super) false_bcb: BasicCoverageBlock, +} + +pub(super) struct CoverageSpans { + bcb_has_mappings: BitSet, + pub(super) mappings: Vec, + pub(super) branch_pairs: Vec, + test_vector_bitmap_bytes: u32, +} + +impl CoverageSpans { + pub(super) fn bcb_has_coverage_spans(&self, bcb: BasicCoverageBlock) -> bool { + self.bcb_has_mappings.contains(bcb) + } + + pub(super) fn test_vector_bitmap_bytes(&self) -> u32 { + self.test_vector_bitmap_bytes + } +} + +/// Extracts coverage-relevant spans from MIR, and associates them with +/// their corresponding BCBs. +/// +/// Returns `None` if no coverage-relevant spans could be extracted. +pub(super) fn generate_coverage_spans( + mir_body: &mir::Body<'_>, + hir_info: &ExtractedHirInfo, + basic_coverage_blocks: &CoverageGraph, +) -> Option { + let mut mappings = vec![]; + let mut branch_pairs = vec![]; + + if hir_info.is_async_fn { + // An async function desugars into a function that returns a future, + // with the user code wrapped in a closure. Any spans in the desugared + // outer function will be unhelpful, so just keep the signature span + // and ignore all of the spans in the MIR body. + if let Some(span) = hir_info.fn_sig_span_extended { + mappings.push(BcbMapping { kind: BcbMappingKind::Code(START_BCB), span }); + } + } else { + extract_refined_covspans(mir_body, hir_info, basic_coverage_blocks, &mut mappings); + + branch_pairs.extend(extract_branch_pairs(mir_body, hir_info, basic_coverage_blocks)); + + mappings.extend(extract_mcdc_mappings(mir_body, hir_info.body_span, basic_coverage_blocks)); + } + + if mappings.is_empty() && branch_pairs.is_empty() { + return None; + } + + // Identify which BCBs have one or more mappings. + let mut bcb_has_mappings = BitSet::new_empty(basic_coverage_blocks.num_nodes()); + let mut insert = |bcb| { + bcb_has_mappings.insert(bcb); + }; + let mut test_vector_bitmap_bytes = 0; + for BcbMapping { kind, span: _ } in &mappings { + match *kind { + BcbMappingKind::Code(bcb) => insert(bcb), + BcbMappingKind::MCDCBranch { true_bcb, false_bcb, .. } => { + insert(true_bcb); + insert(false_bcb); + } + BcbMappingKind::MCDCDecision { bitmap_idx, conditions_num, .. } => { + // `bcb_has_mappings` is used for inject coverage counters + // but they are not needed for decision BCBs. + // While the length of test vector bitmap should be calculated here. + test_vector_bitmap_bytes = test_vector_bitmap_bytes + .max(bitmap_idx + (1_u32 << conditions_num as u32).div_ceil(8)); + } + } + } + for &BcbBranchPair { true_bcb, false_bcb, .. } in &branch_pairs { + insert(true_bcb); + insert(false_bcb); + } + + Some(CoverageSpans { bcb_has_mappings, mappings, branch_pairs, test_vector_bitmap_bytes }) +} + +fn resolve_block_markers( + branch_info: &mir::coverage::BranchInfo, + mir_body: &mir::Body<'_>, +) -> IndexVec> { + let mut block_markers = IndexVec::>::from_elem_n( + None, + branch_info.num_block_markers, + ); + + // Fill out the mapping from block marker IDs to their enclosing blocks. + for (bb, data) in mir_body.basic_blocks.iter_enumerated() { + for statement in &data.statements { + if let StatementKind::Coverage(CoverageKind::BlockMarker { id }) = statement.kind { + block_markers[id] = Some(bb); + } + } + } + + block_markers +} + +// FIXME: There is currently a lot of redundancy between +// `extract_branch_pairs` and `extract_mcdc_mappings`. This is needed so +// that they can each be modified without interfering with the other, but in +// the long term we should try to bring them together again when branch coverage +// and MC/DC coverage support are more mature. + +pub(super) fn extract_branch_pairs( + mir_body: &mir::Body<'_>, + hir_info: &ExtractedHirInfo, + basic_coverage_blocks: &CoverageGraph, +) -> Vec { + let Some(branch_info) = mir_body.coverage_branch_info.as_deref() else { return vec![] }; + + let block_markers = resolve_block_markers(branch_info, mir_body); + + branch_info + .branch_spans + .iter() + .filter_map(|&BranchSpan { span: raw_span, true_marker, false_marker }| { + // For now, ignore any branch span that was introduced by + // expansion. This makes things like assert macros less noisy. + if !raw_span.ctxt().outer_expn_data().is_root() { + return None; + } + let (span, _) = + unexpand_into_body_span_with_visible_macro(raw_span, hir_info.body_span)?; + + let bcb_from_marker = + |marker: BlockMarkerId| basic_coverage_blocks.bcb_from_bb(block_markers[marker]?); + + let true_bcb = bcb_from_marker(true_marker)?; + let false_bcb = bcb_from_marker(false_marker)?; + + Some(BcbBranchPair { span, true_bcb, false_bcb }) + }) + .collect::>() +} + +pub(super) fn extract_mcdc_mappings( + mir_body: &mir::Body<'_>, + body_span: Span, + basic_coverage_blocks: &CoverageGraph, +) -> Vec { + let Some(branch_info) = mir_body.coverage_branch_info.as_deref() else { + return vec![]; + }; + + let block_markers = resolve_block_markers(branch_info, mir_body); + + let bcb_from_marker = + |marker: BlockMarkerId| basic_coverage_blocks.bcb_from_bb(block_markers[marker]?); + + let check_branch_bcb = + |raw_span: Span, true_marker: BlockMarkerId, false_marker: BlockMarkerId| { + // For now, ignore any branch span that was introduced by + // expansion. This makes things like assert macros less noisy. + if !raw_span.ctxt().outer_expn_data().is_root() { + return None; + } + let (span, _) = unexpand_into_body_span_with_visible_macro(raw_span, body_span)?; + + let true_bcb = bcb_from_marker(true_marker)?; + let false_bcb = bcb_from_marker(false_marker)?; + Some((span, true_bcb, false_bcb)) + }; + + let mcdc_branch_filter_map = |&MCDCBranchSpan { + span: raw_span, + true_marker, + false_marker, + condition_info, + decision_depth, + }| { + check_branch_bcb(raw_span, true_marker, false_marker).map(|(span, true_bcb, false_bcb)| { + BcbMapping { + kind: BcbMappingKind::MCDCBranch { + true_bcb, + false_bcb, + condition_info, + decision_depth, + }, + span, + } + }) + }; + + let mut next_bitmap_idx = 0; + + let decision_filter_map = |decision: &MCDCDecisionSpan| { + let (span, _) = unexpand_into_body_span_with_visible_macro(decision.span, body_span)?; + + let end_bcbs = decision + .end_markers + .iter() + .map(|&marker| bcb_from_marker(marker)) + .collect::>()?; + + let bitmap_idx = next_bitmap_idx; + next_bitmap_idx += (1_u32 << decision.conditions_num).div_ceil(8); + + Some(BcbMapping { + kind: BcbMappingKind::MCDCDecision { + end_bcbs, + bitmap_idx, + conditions_num: decision.conditions_num as u16, + decision_depth: decision.decision_depth, + }, + span, + }) + }; + + std::iter::empty() + .chain(branch_info.mcdc_branch_spans.iter().filter_map(mcdc_branch_filter_map)) + .chain(branch_info.mcdc_decision_spans.iter().filter_map(decision_filter_map)) + .collect::>() +} diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs index 159c099fac507..9edde6662469e 100644 --- a/compiler/rustc_mir_transform/src/coverage/mod.rs +++ b/compiler/rustc_mir_transform/src/coverage/mod.rs @@ -2,14 +2,14 @@ pub mod query; mod counters; mod graph; +mod mappings; mod spans; - #[cfg(test)] mod tests; use self::counters::{CounterIncrementSite, CoverageCounters}; use self::graph::{BasicCoverageBlock, CoverageGraph}; -use self::spans::{BcbBranchPair, BcbMapping, BcbMappingKind, CoverageSpans}; +use self::mappings::{BcbBranchPair, BcbMapping, BcbMappingKind, CoverageSpans}; use crate::MirPass; @@ -71,7 +71,7 @@ fn instrument_function_for_coverage<'tcx>(tcx: TyCtxt<'tcx>, mir_body: &mut mir: //////////////////////////////////////////////////// // Compute coverage spans from the `CoverageGraph`. let Some(coverage_spans) = - spans::generate_coverage_spans(mir_body, &hir_info, &basic_coverage_blocks) + mappings::generate_coverage_spans(mir_body, &hir_info, &basic_coverage_blocks) else { // No relevant spans were found in MIR, so skip instrumenting this function. return; diff --git a/compiler/rustc_mir_transform/src/coverage/spans.rs b/compiler/rustc_mir_transform/src/coverage/spans.rs index b64b1212cecc6..d6432e2e9d41c 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans.rs @@ -1,152 +1,31 @@ -use rustc_data_structures::graph::DirectedGraph; -use rustc_index::bit_set::BitSet; use rustc_middle::mir; -use rustc_middle::mir::coverage::ConditionInfo; use rustc_span::{BytePos, Span}; -use std::collections::BTreeSet; -use crate::coverage::graph::{BasicCoverageBlock, CoverageGraph, START_BCB}; +use crate::coverage::graph::{BasicCoverageBlock, CoverageGraph}; +use crate::coverage::mappings::{BcbMapping, BcbMappingKind}; use crate::coverage::spans::from_mir::SpanFromMir; use crate::coverage::ExtractedHirInfo; mod from_mir; -#[derive(Clone, Debug)] -pub(super) enum BcbMappingKind { - /// Associates an ordinary executable code span with its corresponding BCB. - Code(BasicCoverageBlock), - - // Ordinary branch mappings are stored separately, so they don't have a - // variant in this enum. - // - /// Associates a mcdc branch span with condition info besides fields for normal branch. - MCDCBranch { - true_bcb: BasicCoverageBlock, - false_bcb: BasicCoverageBlock, - /// If `None`, this actually represents a normal branch mapping inserted - /// for code that was too complex for MC/DC. - condition_info: Option, - decision_depth: u16, - }, - /// Associates a mcdc decision with its join BCB. - MCDCDecision { - end_bcbs: BTreeSet, - bitmap_idx: u32, - conditions_num: u16, - decision_depth: u16, - }, -} - -#[derive(Debug)] -pub(super) struct BcbMapping { - pub(super) kind: BcbMappingKind, - pub(super) span: Span, -} - -/// This is separate from [`BcbMappingKind`] to help prepare for larger changes -/// that will be needed for improved branch coverage in the future. -/// (See .) -#[derive(Debug)] -pub(super) struct BcbBranchPair { - pub(super) span: Span, - pub(super) true_bcb: BasicCoverageBlock, - pub(super) false_bcb: BasicCoverageBlock, -} - -pub(super) struct CoverageSpans { - bcb_has_mappings: BitSet, - pub(super) mappings: Vec, - pub(super) branch_pairs: Vec, - test_vector_bitmap_bytes: u32, -} - -impl CoverageSpans { - pub(super) fn bcb_has_coverage_spans(&self, bcb: BasicCoverageBlock) -> bool { - self.bcb_has_mappings.contains(bcb) - } - - pub(super) fn test_vector_bitmap_bytes(&self) -> u32 { - self.test_vector_bitmap_bytes - } -} +// FIXME(#124545) It's awkward that we have to re-export this, because it's an +// internal detail of `from_mir` that is also needed when handling branch and +// MC/DC spans. Ideally we would find a more natural home for it. +pub(super) use from_mir::unexpand_into_body_span_with_visible_macro; -/// Extracts coverage-relevant spans from MIR, and associates them with -/// their corresponding BCBs. -/// -/// Returns `None` if no coverage-relevant spans could be extracted. -pub(super) fn generate_coverage_spans( +pub(super) fn extract_refined_covspans( mir_body: &mir::Body<'_>, hir_info: &ExtractedHirInfo, basic_coverage_blocks: &CoverageGraph, -) -> Option { - let mut mappings = vec![]; - let mut branch_pairs = vec![]; - - if hir_info.is_async_fn { - // An async function desugars into a function that returns a future, - // with the user code wrapped in a closure. Any spans in the desugared - // outer function will be unhelpful, so just keep the signature span - // and ignore all of the spans in the MIR body. - if let Some(span) = hir_info.fn_sig_span_extended { - mappings.push(BcbMapping { kind: BcbMappingKind::Code(START_BCB), span }); - } - } else { - let sorted_spans = from_mir::mir_to_initial_sorted_coverage_spans( - mir_body, - hir_info, - basic_coverage_blocks, - ); - let coverage_spans = SpansRefiner::refine_sorted_spans(sorted_spans); - mappings.extend(coverage_spans.into_iter().map(|RefinedCovspan { bcb, span, .. }| { - // Each span produced by the generator represents an ordinary code region. - BcbMapping { kind: BcbMappingKind::Code(bcb), span } - })); - - branch_pairs.extend(from_mir::extract_branch_pairs( - mir_body, - hir_info, - basic_coverage_blocks, - )); - - mappings.extend(from_mir::extract_mcdc_mappings( - mir_body, - hir_info.body_span, - basic_coverage_blocks, - )); - } - - if mappings.is_empty() && branch_pairs.is_empty() { - return None; - } - - // Identify which BCBs have one or more mappings. - let mut bcb_has_mappings = BitSet::new_empty(basic_coverage_blocks.num_nodes()); - let mut insert = |bcb| { - bcb_has_mappings.insert(bcb); - }; - let mut test_vector_bitmap_bytes = 0; - for BcbMapping { kind, span: _ } in &mappings { - match *kind { - BcbMappingKind::Code(bcb) => insert(bcb), - BcbMappingKind::MCDCBranch { true_bcb, false_bcb, .. } => { - insert(true_bcb); - insert(false_bcb); - } - BcbMappingKind::MCDCDecision { bitmap_idx, conditions_num, .. } => { - // `bcb_has_mappings` is used for inject coverage counters - // but they are not needed for decision BCBs. - // While the length of test vector bitmap should be calculated here. - test_vector_bitmap_bytes = test_vector_bitmap_bytes - .max(bitmap_idx + (1_u32 << conditions_num as u32).div_ceil(8)); - } - } - } - for &BcbBranchPair { true_bcb, false_bcb, .. } in &branch_pairs { - insert(true_bcb); - insert(false_bcb); - } - - Some(CoverageSpans { bcb_has_mappings, mappings, branch_pairs, test_vector_bitmap_bytes }) + mappings: &mut impl Extend, +) { + let sorted_spans = + from_mir::mir_to_initial_sorted_coverage_spans(mir_body, hir_info, basic_coverage_blocks); + let coverage_spans = SpansRefiner::refine_sorted_spans(sorted_spans); + mappings.extend(coverage_spans.into_iter().map(|RefinedCovspan { bcb, span, .. }| { + // Each span produced by the generator represents an ordinary code region. + BcbMapping { kind: BcbMappingKind::Code(bcb), span } + })); } #[derive(Debug)] diff --git a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs index 142dfc17fb8f1..4ce37b5defcee 100644 --- a/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs +++ b/compiler/rustc_mir_transform/src/coverage/spans/from_mir.rs @@ -1,11 +1,8 @@ use rustc_data_structures::captures::Captures; use rustc_data_structures::fx::FxHashSet; -use rustc_index::IndexVec; -use rustc_middle::mir::coverage::{ - BlockMarkerId, BranchSpan, CoverageKind, MCDCBranchSpan, MCDCDecisionSpan, -}; +use rustc_middle::mir::coverage::CoverageKind; use rustc_middle::mir::{ - self, AggregateKind, BasicBlock, FakeReadCause, Rvalue, Statement, StatementKind, Terminator, + self, AggregateKind, FakeReadCause, Rvalue, Statement, StatementKind, Terminator, TerminatorKind, }; use rustc_span::{ExpnKind, MacroKind, Span, Symbol}; @@ -13,7 +10,6 @@ use rustc_span::{ExpnKind, MacroKind, Span, Symbol}; use crate::coverage::graph::{ BasicCoverageBlock, BasicCoverageBlockData, CoverageGraph, START_BCB, }; -use crate::coverage::spans::{BcbBranchPair, BcbMapping, BcbMappingKind}; use crate::coverage::ExtractedHirInfo; /// Traverses the MIR body to produce an initial collection of coverage-relevant @@ -287,7 +283,7 @@ fn filtered_terminator_span(terminator: &Terminator<'_>) -> Option { /// /// [^1]Expansions result from Rust syntax including macros, syntactic sugar, /// etc.). -fn unexpand_into_body_span_with_visible_macro( +pub(crate) fn unexpand_into_body_span_with_visible_macro( original_span: Span, body_span: Span, ) -> Option<(Span, Option)> { @@ -365,141 +361,3 @@ impl SpanFromMir { Self { span, visible_macro, bcb, is_hole } } } - -fn resolve_block_markers( - branch_info: &mir::coverage::BranchInfo, - mir_body: &mir::Body<'_>, -) -> IndexVec> { - let mut block_markers = IndexVec::>::from_elem_n( - None, - branch_info.num_block_markers, - ); - - // Fill out the mapping from block marker IDs to their enclosing blocks. - for (bb, data) in mir_body.basic_blocks.iter_enumerated() { - for statement in &data.statements { - if let StatementKind::Coverage(CoverageKind::BlockMarker { id }) = statement.kind { - block_markers[id] = Some(bb); - } - } - } - - block_markers -} - -// FIXME: There is currently a lot of redundancy between -// `extract_branch_pairs` and `extract_mcdc_mappings`. This is needed so -// that they can each be modified without interfering with the other, but in -// the long term we should try to bring them together again when branch coverage -// and MC/DC coverage support are more mature. - -pub(super) fn extract_branch_pairs( - mir_body: &mir::Body<'_>, - hir_info: &ExtractedHirInfo, - basic_coverage_blocks: &CoverageGraph, -) -> Vec { - let Some(branch_info) = mir_body.coverage_branch_info.as_deref() else { return vec![] }; - - let block_markers = resolve_block_markers(branch_info, mir_body); - - branch_info - .branch_spans - .iter() - .filter_map(|&BranchSpan { span: raw_span, true_marker, false_marker }| { - // For now, ignore any branch span that was introduced by - // expansion. This makes things like assert macros less noisy. - if !raw_span.ctxt().outer_expn_data().is_root() { - return None; - } - let (span, _) = - unexpand_into_body_span_with_visible_macro(raw_span, hir_info.body_span)?; - - let bcb_from_marker = - |marker: BlockMarkerId| basic_coverage_blocks.bcb_from_bb(block_markers[marker]?); - - let true_bcb = bcb_from_marker(true_marker)?; - let false_bcb = bcb_from_marker(false_marker)?; - - Some(BcbBranchPair { span, true_bcb, false_bcb }) - }) - .collect::>() -} - -pub(super) fn extract_mcdc_mappings( - mir_body: &mir::Body<'_>, - body_span: Span, - basic_coverage_blocks: &CoverageGraph, -) -> Vec { - let Some(branch_info) = mir_body.coverage_branch_info.as_deref() else { - return vec![]; - }; - - let block_markers = resolve_block_markers(branch_info, mir_body); - - let bcb_from_marker = - |marker: BlockMarkerId| basic_coverage_blocks.bcb_from_bb(block_markers[marker]?); - - let check_branch_bcb = - |raw_span: Span, true_marker: BlockMarkerId, false_marker: BlockMarkerId| { - // For now, ignore any branch span that was introduced by - // expansion. This makes things like assert macros less noisy. - if !raw_span.ctxt().outer_expn_data().is_root() { - return None; - } - let (span, _) = unexpand_into_body_span_with_visible_macro(raw_span, body_span)?; - - let true_bcb = bcb_from_marker(true_marker)?; - let false_bcb = bcb_from_marker(false_marker)?; - Some((span, true_bcb, false_bcb)) - }; - - let mcdc_branch_filter_map = |&MCDCBranchSpan { - span: raw_span, - true_marker, - false_marker, - condition_info, - decision_depth, - }| { - check_branch_bcb(raw_span, true_marker, false_marker).map(|(span, true_bcb, false_bcb)| { - BcbMapping { - kind: BcbMappingKind::MCDCBranch { - true_bcb, - false_bcb, - condition_info, - decision_depth, - }, - span, - } - }) - }; - - let mut next_bitmap_idx = 0; - - let decision_filter_map = |decision: &MCDCDecisionSpan| { - let (span, _) = unexpand_into_body_span_with_visible_macro(decision.span, body_span)?; - - let end_bcbs = decision - .end_markers - .iter() - .map(|&marker| bcb_from_marker(marker)) - .collect::>()?; - - let bitmap_idx = next_bitmap_idx; - next_bitmap_idx += (1_u32 << decision.conditions_num).div_ceil(8); - - Some(BcbMapping { - kind: BcbMappingKind::MCDCDecision { - end_bcbs, - bitmap_idx, - conditions_num: decision.conditions_num as u16, - decision_depth: decision.decision_depth, - }, - span, - }) - }; - - std::iter::empty() - .chain(branch_info.mcdc_branch_spans.iter().filter_map(mcdc_branch_filter_map)) - .chain(branch_info.mcdc_decision_spans.iter().filter_map(decision_filter_map)) - .collect::>() -}