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Diffstat (limited to 'compiler/rustc_mir_transform/src/coverage/debug.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/coverage/debug.rs | 831 |
1 files changed, 831 insertions, 0 deletions
diff --git a/compiler/rustc_mir_transform/src/coverage/debug.rs b/compiler/rustc_mir_transform/src/coverage/debug.rs new file mode 100644 index 000000000..0f8679b0b --- /dev/null +++ b/compiler/rustc_mir_transform/src/coverage/debug.rs @@ -0,0 +1,831 @@ +//! The `InstrumentCoverage` MIR pass implementation includes debugging tools and options +//! to help developers understand and/or improve the analysis and instrumentation of a MIR. +//! +//! To enable coverage, include the rustc command line option: +//! +//! * `-C instrument-coverage` +//! +//! MIR Dump Files, with additional `CoverageGraph` graphviz and `CoverageSpan` spanview +//! ------------------------------------------------------------------------------------ +//! +//! Additional debugging options include: +//! +//! * `-Z dump-mir=InstrumentCoverage` - Generate `.mir` files showing the state of the MIR, +//! before and after the `InstrumentCoverage` pass, for each compiled function. +//! +//! * `-Z dump-mir-graphviz` - If `-Z dump-mir` is also enabled for the current MIR node path, +//! each MIR dump is accompanied by a before-and-after graphical view of the MIR, in Graphviz +//! `.dot` file format (which can be visually rendered as a graph using any of a number of free +//! Graphviz viewers and IDE extensions). +//! +//! For the `InstrumentCoverage` pass, this option also enables generation of an additional +//! Graphviz `.dot` file for each function, rendering the `CoverageGraph`: the control flow +//! graph (CFG) of `BasicCoverageBlocks` (BCBs), as nodes, internally labeled to show the +//! `CoverageSpan`-based MIR elements each BCB represents (`BasicBlock`s, `Statement`s and +//! `Terminator`s), assigned coverage counters and/or expressions, and edge counters, as needed. +//! +//! (Note the additional option, `-Z graphviz-dark-mode`, can be added, to change the rendered +//! output from its default black-on-white background to a dark color theme, if desired.) +//! +//! * `-Z dump-mir-spanview` - If `-Z dump-mir` is also enabled for the current MIR node path, +//! each MIR dump is accompanied by a before-and-after `.html` document showing the function's +//! original source code, highlighted by it's MIR spans, at the `statement`-level (by default), +//! `terminator` only, or encompassing span for the `Terminator` plus all `Statement`s, in each +//! `block` (`BasicBlock`). +//! +//! For the `InstrumentCoverage` pass, this option also enables generation of an additional +//! spanview `.html` file for each function, showing the aggregated `CoverageSpan`s that will +//! require counters (or counter expressions) for accurate coverage analysis. +//! +//! Debug Logging +//! ------------- +//! +//! The `InstrumentCoverage` pass includes debug logging messages at various phases and decision +//! points, which can be enabled via environment variable: +//! +//! ```shell +//! RUSTC_LOG=rustc_mir_transform::transform::coverage=debug +//! ``` +//! +//! Other module paths with coverage-related debug logs may also be of interest, particularly for +//! debugging the coverage map data, injected as global variables in the LLVM IR (during rustc's +//! code generation pass). For example: +//! +//! ```shell +//! RUSTC_LOG=rustc_mir_transform::transform::coverage,rustc_codegen_ssa::coverageinfo,rustc_codegen_llvm::coverageinfo=debug +//! ``` +//! +//! Coverage Debug Options +//! --------------------------------- +//! +//! Additional debugging options can be enabled using the environment variable: +//! +//! ```shell +//! RUSTC_COVERAGE_DEBUG_OPTIONS=<options> +//! ``` +//! +//! These options are comma-separated, and specified in the format `option-name=value`. For example: +//! +//! ```shell +//! $ RUSTC_COVERAGE_DEBUG_OPTIONS=counter-format=id+operation,allow-unused-expressions=yes cargo build +//! ``` +//! +//! Coverage debug options include: +//! +//! * `allow-unused-expressions=yes` or `no` (default: `no`) +//! +//! The `InstrumentCoverage` algorithms _should_ only create and assign expressions to a +//! `BasicCoverageBlock`, or an incoming edge, if that expression is either (a) required to +//! count a `CoverageSpan`, or (b) a dependency of some other required counter expression. +//! +//! If an expression is generated that does not map to a `CoverageSpan` or dependency, this +//! probably indicates there was a bug in the algorithm that creates and assigns counters +//! and expressions. +//! +//! When this kind of bug is encountered, the rustc compiler will panic by default. Setting: +//! `allow-unused-expressions=yes` will log a warning message instead of panicking (effectively +//! ignoring the unused expressions), which may be helpful when debugging the root cause of +//! the problem. +//! +//! * `counter-format=<choices>`, where `<choices>` can be any plus-separated combination of `id`, +//! `block`, and/or `operation` (default: `block+operation`) +//! +//! This option effects both the `CoverageGraph` (graphviz `.dot` files) and debug logging, when +//! generating labels for counters and expressions. +//! +//! Depending on the values and combinations, counters can be labeled by: +//! +//! * `id` - counter or expression ID (ascending counter IDs, starting at 1, or descending +//! expression IDs, starting at `u32:MAX`) +//! * `block` - the `BasicCoverageBlock` label (for example, `bcb0`) or edge label (for +//! example `bcb0->bcb1`), for counters or expressions assigned to count a +//! `BasicCoverageBlock` or edge. Intermediate expressions (not directly associated with +//! a BCB or edge) will be labeled by their expression ID, unless `operation` is also +//! specified. +//! * `operation` - applied to expressions only, labels include the left-hand-side counter +//! or expression label (lhs operand), the operator (`+` or `-`), and the right-hand-side +//! counter or expression (rhs operand). Expression operand labels are generated +//! recursively, generating labels with nested operations, enclosed in parentheses +//! (for example: `bcb2 + (bcb0 - bcb1)`). + +use super::graph::{BasicCoverageBlock, BasicCoverageBlockData, CoverageGraph}; +use super::spans::CoverageSpan; + +use itertools::Itertools; +use rustc_middle::mir::create_dump_file; +use rustc_middle::mir::generic_graphviz::GraphvizWriter; +use rustc_middle::mir::spanview::{self, SpanViewable}; + +use rustc_data_structures::fx::FxHashMap; +use rustc_middle::mir::coverage::*; +use rustc_middle::mir::{self, BasicBlock, TerminatorKind}; +use rustc_middle::ty::TyCtxt; +use rustc_span::Span; + +use std::iter; +use std::ops::Deref; +use std::sync::OnceLock; + +pub const NESTED_INDENT: &str = " "; + +const RUSTC_COVERAGE_DEBUG_OPTIONS: &str = "RUSTC_COVERAGE_DEBUG_OPTIONS"; + +pub(super) fn debug_options<'a>() -> &'a DebugOptions { + static DEBUG_OPTIONS: OnceLock<DebugOptions> = OnceLock::new(); + + &DEBUG_OPTIONS.get_or_init(DebugOptions::from_env) +} + +/// Parses and maintains coverage-specific debug options captured from the environment variable +/// "RUSTC_COVERAGE_DEBUG_OPTIONS", if set. +#[derive(Debug, Clone)] +pub(super) struct DebugOptions { + pub allow_unused_expressions: bool, + counter_format: ExpressionFormat, +} + +impl DebugOptions { + fn from_env() -> Self { + let mut allow_unused_expressions = true; + let mut counter_format = ExpressionFormat::default(); + + if let Ok(env_debug_options) = std::env::var(RUSTC_COVERAGE_DEBUG_OPTIONS) { + for setting_str in env_debug_options.replace(' ', "").replace('-', "_").split(',') { + let (option, value) = match setting_str.split_once('=') { + None => (setting_str, None), + Some((k, v)) => (k, Some(v)), + }; + match option { + "allow_unused_expressions" => { + allow_unused_expressions = bool_option_val(option, value); + debug!( + "{} env option `allow_unused_expressions` is set to {}", + RUSTC_COVERAGE_DEBUG_OPTIONS, allow_unused_expressions + ); + } + "counter_format" => { + match value { + None => { + bug!( + "`{}` option in environment variable {} requires one or more \ + plus-separated choices (a non-empty subset of \ + `id+block+operation`)", + option, + RUSTC_COVERAGE_DEBUG_OPTIONS + ); + } + Some(val) => { + counter_format = counter_format_option_val(val); + debug!( + "{} env option `counter_format` is set to {:?}", + RUSTC_COVERAGE_DEBUG_OPTIONS, counter_format + ); + } + }; + } + _ => bug!( + "Unsupported setting `{}` in environment variable {}", + option, + RUSTC_COVERAGE_DEBUG_OPTIONS + ), + }; + } + } + + Self { allow_unused_expressions, counter_format } + } +} + +fn bool_option_val(option: &str, some_strval: Option<&str>) -> bool { + if let Some(val) = some_strval { + if vec!["yes", "y", "on", "true"].contains(&val) { + true + } else if vec!["no", "n", "off", "false"].contains(&val) { + false + } else { + bug!( + "Unsupported value `{}` for option `{}` in environment variable {}", + option, + val, + RUSTC_COVERAGE_DEBUG_OPTIONS + ) + } + } else { + true + } +} + +fn counter_format_option_val(strval: &str) -> ExpressionFormat { + let mut counter_format = ExpressionFormat { id: false, block: false, operation: false }; + let components = strval.splitn(3, '+'); + for component in components { + match component { + "id" => counter_format.id = true, + "block" => counter_format.block = true, + "operation" => counter_format.operation = true, + _ => bug!( + "Unsupported counter_format choice `{}` in environment variable {}", + component, + RUSTC_COVERAGE_DEBUG_OPTIONS + ), + } + } + counter_format +} + +#[derive(Debug, Clone)] +struct ExpressionFormat { + id: bool, + block: bool, + operation: bool, +} + +impl Default for ExpressionFormat { + fn default() -> Self { + Self { id: false, block: true, operation: true } + } +} + +/// If enabled, this struct maintains a map from `CoverageKind` IDs (as `ExpressionOperandId`) to +/// the `CoverageKind` data and optional label (normally, the counter's associated +/// `BasicCoverageBlock` format string, if any). +/// +/// Use `format_counter` to convert one of these `CoverageKind` counters to a debug output string, +/// as directed by the `DebugOptions`. This allows the format of counter labels in logs and dump +/// files (including the `CoverageGraph` graphviz file) to be changed at runtime, via environment +/// variable. +/// +/// `DebugCounters` supports a recursive rendering of `Expression` counters, so they can be +/// presented as nested expressions such as `(bcb3 - (bcb0 + bcb1))`. +pub(super) struct DebugCounters { + some_counters: Option<FxHashMap<ExpressionOperandId, DebugCounter>>, +} + +impl DebugCounters { + pub fn new() -> Self { + Self { some_counters: None } + } + + pub fn enable(&mut self) { + debug_assert!(!self.is_enabled()); + self.some_counters.replace(FxHashMap::default()); + } + + pub fn is_enabled(&self) -> bool { + self.some_counters.is_some() + } + + pub fn add_counter(&mut self, counter_kind: &CoverageKind, some_block_label: Option<String>) { + if let Some(counters) = &mut self.some_counters { + let id: ExpressionOperandId = match *counter_kind { + CoverageKind::Counter { id, .. } => id.into(), + CoverageKind::Expression { id, .. } => id.into(), + _ => bug!( + "the given `CoverageKind` is not an counter or expression: {:?}", + counter_kind + ), + }; + counters + .try_insert(id, DebugCounter::new(counter_kind.clone(), some_block_label)) + .expect("attempt to add the same counter_kind to DebugCounters more than once"); + } + } + + pub fn some_block_label(&self, operand: ExpressionOperandId) -> Option<&String> { + self.some_counters.as_ref().map_or(None, |counters| { + counters + .get(&operand) + .map_or(None, |debug_counter| debug_counter.some_block_label.as_ref()) + }) + } + + pub fn format_counter(&self, counter_kind: &CoverageKind) -> String { + match *counter_kind { + CoverageKind::Counter { .. } => { + format!("Counter({})", self.format_counter_kind(counter_kind)) + } + CoverageKind::Expression { .. } => { + format!("Expression({})", self.format_counter_kind(counter_kind)) + } + CoverageKind::Unreachable { .. } => "Unreachable".to_owned(), + } + } + + fn format_counter_kind(&self, counter_kind: &CoverageKind) -> String { + let counter_format = &debug_options().counter_format; + if let CoverageKind::Expression { id, lhs, op, rhs } = *counter_kind { + if counter_format.operation { + return format!( + "{}{} {} {}", + if counter_format.id || self.some_counters.is_none() { + format!("#{} = ", id.index()) + } else { + String::new() + }, + self.format_operand(lhs), + if op == Op::Add { "+" } else { "-" }, + self.format_operand(rhs), + ); + } + } + + let id: ExpressionOperandId = match *counter_kind { + CoverageKind::Counter { id, .. } => id.into(), + CoverageKind::Expression { id, .. } => id.into(), + _ => { + bug!("the given `CoverageKind` is not an counter or expression: {:?}", counter_kind) + } + }; + if self.some_counters.is_some() && (counter_format.block || !counter_format.id) { + let counters = self.some_counters.as_ref().unwrap(); + if let Some(DebugCounter { some_block_label: Some(block_label), .. }) = + counters.get(&id) + { + return if counter_format.id { + format!("{}#{}", block_label, id.index()) + } else { + block_label.to_string() + }; + } + } + format!("#{}", id.index()) + } + + fn format_operand(&self, operand: ExpressionOperandId) -> String { + if operand.index() == 0 { + return String::from("0"); + } + if let Some(counters) = &self.some_counters { + if let Some(DebugCounter { counter_kind, some_block_label }) = counters.get(&operand) { + if let CoverageKind::Expression { .. } = counter_kind { + if let Some(label) = some_block_label && debug_options().counter_format.block { + return format!( + "{}:({})", + label, + self.format_counter_kind(counter_kind) + ); + } + return format!("({})", self.format_counter_kind(counter_kind)); + } + return self.format_counter_kind(counter_kind); + } + } + format!("#{}", operand.index()) + } +} + +/// A non-public support class to `DebugCounters`. +#[derive(Debug)] +struct DebugCounter { + counter_kind: CoverageKind, + some_block_label: Option<String>, +} + +impl DebugCounter { + fn new(counter_kind: CoverageKind, some_block_label: Option<String>) -> Self { + Self { counter_kind, some_block_label } + } +} + +/// If enabled, this data structure captures additional debugging information used when generating +/// a Graphviz (.dot file) representation of the `CoverageGraph`, for debugging purposes. +pub(super) struct GraphvizData { + some_bcb_to_coverage_spans_with_counters: + Option<FxHashMap<BasicCoverageBlock, Vec<(CoverageSpan, CoverageKind)>>>, + some_bcb_to_dependency_counters: Option<FxHashMap<BasicCoverageBlock, Vec<CoverageKind>>>, + some_edge_to_counter: Option<FxHashMap<(BasicCoverageBlock, BasicBlock), CoverageKind>>, +} + +impl GraphvizData { + pub fn new() -> Self { + Self { + some_bcb_to_coverage_spans_with_counters: None, + some_bcb_to_dependency_counters: None, + some_edge_to_counter: None, + } + } + + pub fn enable(&mut self) { + debug_assert!(!self.is_enabled()); + self.some_bcb_to_coverage_spans_with_counters = Some(FxHashMap::default()); + self.some_bcb_to_dependency_counters = Some(FxHashMap::default()); + self.some_edge_to_counter = Some(FxHashMap::default()); + } + + pub fn is_enabled(&self) -> bool { + self.some_bcb_to_coverage_spans_with_counters.is_some() + } + + pub fn add_bcb_coverage_span_with_counter( + &mut self, + bcb: BasicCoverageBlock, + coverage_span: &CoverageSpan, + counter_kind: &CoverageKind, + ) { + if let Some(bcb_to_coverage_spans_with_counters) = + self.some_bcb_to_coverage_spans_with_counters.as_mut() + { + bcb_to_coverage_spans_with_counters + .entry(bcb) + .or_insert_with(Vec::new) + .push((coverage_span.clone(), counter_kind.clone())); + } + } + + pub fn get_bcb_coverage_spans_with_counters( + &self, + bcb: BasicCoverageBlock, + ) -> Option<&[(CoverageSpan, CoverageKind)]> { + if let Some(bcb_to_coverage_spans_with_counters) = + self.some_bcb_to_coverage_spans_with_counters.as_ref() + { + bcb_to_coverage_spans_with_counters.get(&bcb).map(Deref::deref) + } else { + None + } + } + + pub fn add_bcb_dependency_counter( + &mut self, + bcb: BasicCoverageBlock, + counter_kind: &CoverageKind, + ) { + if let Some(bcb_to_dependency_counters) = self.some_bcb_to_dependency_counters.as_mut() { + bcb_to_dependency_counters + .entry(bcb) + .or_insert_with(Vec::new) + .push(counter_kind.clone()); + } + } + + pub fn get_bcb_dependency_counters(&self, bcb: BasicCoverageBlock) -> Option<&[CoverageKind]> { + if let Some(bcb_to_dependency_counters) = self.some_bcb_to_dependency_counters.as_ref() { + bcb_to_dependency_counters.get(&bcb).map(Deref::deref) + } else { + None + } + } + + pub fn set_edge_counter( + &mut self, + from_bcb: BasicCoverageBlock, + to_bb: BasicBlock, + counter_kind: &CoverageKind, + ) { + if let Some(edge_to_counter) = self.some_edge_to_counter.as_mut() { + edge_to_counter + .try_insert((from_bcb, to_bb), counter_kind.clone()) + .expect("invalid attempt to insert more than one edge counter for the same edge"); + } + } + + pub fn get_edge_counter( + &self, + from_bcb: BasicCoverageBlock, + to_bb: BasicBlock, + ) -> Option<&CoverageKind> { + if let Some(edge_to_counter) = self.some_edge_to_counter.as_ref() { + edge_to_counter.get(&(from_bcb, to_bb)) + } else { + None + } + } +} + +/// If enabled, this struct captures additional data used to track whether expressions were used, +/// directly or indirectly, to compute the coverage counts for all `CoverageSpan`s, and any that are +/// _not_ used are retained in the `unused_expressions` Vec, to be included in debug output (logs +/// and/or a `CoverageGraph` graphviz output). +pub(super) struct UsedExpressions { + some_used_expression_operands: + Option<FxHashMap<ExpressionOperandId, Vec<InjectedExpressionId>>>, + some_unused_expressions: + Option<Vec<(CoverageKind, Option<BasicCoverageBlock>, BasicCoverageBlock)>>, +} + +impl UsedExpressions { + pub fn new() -> Self { + Self { some_used_expression_operands: None, some_unused_expressions: None } + } + + pub fn enable(&mut self) { + debug_assert!(!self.is_enabled()); + self.some_used_expression_operands = Some(FxHashMap::default()); + self.some_unused_expressions = Some(Vec::new()); + } + + pub fn is_enabled(&self) -> bool { + self.some_used_expression_operands.is_some() + } + + pub fn add_expression_operands(&mut self, expression: &CoverageKind) { + if let Some(used_expression_operands) = self.some_used_expression_operands.as_mut() { + if let CoverageKind::Expression { id, lhs, rhs, .. } = *expression { + used_expression_operands.entry(lhs).or_insert_with(Vec::new).push(id); + used_expression_operands.entry(rhs).or_insert_with(Vec::new).push(id); + } + } + } + + pub fn expression_is_used(&self, expression: &CoverageKind) -> bool { + if let Some(used_expression_operands) = self.some_used_expression_operands.as_ref() { + used_expression_operands.contains_key(&expression.as_operand_id()) + } else { + false + } + } + + pub fn add_unused_expression_if_not_found( + &mut self, + expression: &CoverageKind, + edge_from_bcb: Option<BasicCoverageBlock>, + target_bcb: BasicCoverageBlock, + ) { + if let Some(used_expression_operands) = self.some_used_expression_operands.as_ref() { + if !used_expression_operands.contains_key(&expression.as_operand_id()) { + self.some_unused_expressions.as_mut().unwrap().push(( + expression.clone(), + edge_from_bcb, + target_bcb, + )); + } + } + } + + /// Return the list of unused counters (if any) as a tuple with the counter (`CoverageKind`), + /// optional `from_bcb` (if it was an edge counter), and `target_bcb`. + pub fn get_unused_expressions( + &self, + ) -> Vec<(CoverageKind, Option<BasicCoverageBlock>, BasicCoverageBlock)> { + if let Some(unused_expressions) = self.some_unused_expressions.as_ref() { + unused_expressions.clone() + } else { + Vec::new() + } + } + + /// If enabled, validate that every BCB or edge counter not directly associated with a coverage + /// span is at least indirectly associated (it is a dependency of a BCB counter that _is_ + /// associated with a coverage span). + pub fn validate( + &mut self, + bcb_counters_without_direct_coverage_spans: &[( + Option<BasicCoverageBlock>, + BasicCoverageBlock, + CoverageKind, + )], + ) { + if self.is_enabled() { + let mut not_validated = bcb_counters_without_direct_coverage_spans + .iter() + .map(|(_, _, counter_kind)| counter_kind) + .collect::<Vec<_>>(); + let mut validating_count = 0; + while not_validated.len() != validating_count { + let to_validate = not_validated.split_off(0); + validating_count = to_validate.len(); + for counter_kind in to_validate { + if self.expression_is_used(counter_kind) { + self.add_expression_operands(counter_kind); + } else { + not_validated.push(counter_kind); + } + } + } + } + } + + pub fn alert_on_unused_expressions(&self, debug_counters: &DebugCounters) { + if let Some(unused_expressions) = self.some_unused_expressions.as_ref() { + for (counter_kind, edge_from_bcb, target_bcb) in unused_expressions { + let unused_counter_message = if let Some(from_bcb) = edge_from_bcb.as_ref() { + format!( + "non-coverage edge counter found without a dependent expression, in \ + {:?}->{:?}; counter={}", + from_bcb, + target_bcb, + debug_counters.format_counter(&counter_kind), + ) + } else { + format!( + "non-coverage counter found without a dependent expression, in {:?}; \ + counter={}", + target_bcb, + debug_counters.format_counter(&counter_kind), + ) + }; + + if debug_options().allow_unused_expressions { + debug!("WARNING: {}", unused_counter_message); + } else { + bug!("{}", unused_counter_message); + } + } + } + } +} + +/// Generates the MIR pass `CoverageSpan`-specific spanview dump file. +pub(super) fn dump_coverage_spanview<'tcx>( + tcx: TyCtxt<'tcx>, + mir_body: &mir::Body<'tcx>, + basic_coverage_blocks: &CoverageGraph, + pass_name: &str, + body_span: Span, + coverage_spans: &[CoverageSpan], +) { + let mir_source = mir_body.source; + let def_id = mir_source.def_id(); + + let span_viewables = span_viewables(tcx, mir_body, basic_coverage_blocks, &coverage_spans); + let mut file = create_dump_file(tcx, "html", None, pass_name, &0, mir_source) + .expect("Unexpected error creating MIR spanview HTML file"); + let crate_name = tcx.crate_name(def_id.krate); + let item_name = tcx.def_path(def_id).to_filename_friendly_no_crate(); + let title = format!("{}.{} - Coverage Spans", crate_name, item_name); + spanview::write_document(tcx, body_span, span_viewables, &title, &mut file) + .expect("Unexpected IO error dumping coverage spans as HTML"); +} + +/// Converts the computed `BasicCoverageBlockData`s into `SpanViewable`s. +fn span_viewables<'tcx>( + tcx: TyCtxt<'tcx>, + mir_body: &mir::Body<'tcx>, + basic_coverage_blocks: &CoverageGraph, + coverage_spans: &[CoverageSpan], +) -> Vec<SpanViewable> { + let mut span_viewables = Vec::new(); + for coverage_span in coverage_spans { + let tooltip = coverage_span.format_coverage_statements(tcx, mir_body); + let CoverageSpan { span, bcb, .. } = coverage_span; + let bcb_data = &basic_coverage_blocks[*bcb]; + let id = bcb_data.id(); + let leader_bb = bcb_data.leader_bb(); + span_viewables.push(SpanViewable { bb: leader_bb, span: *span, id, tooltip }); + } + span_viewables +} + +/// Generates the MIR pass coverage-specific graphviz dump file. +pub(super) fn dump_coverage_graphviz<'tcx>( + tcx: TyCtxt<'tcx>, + mir_body: &mir::Body<'tcx>, + pass_name: &str, + basic_coverage_blocks: &CoverageGraph, + debug_counters: &DebugCounters, + graphviz_data: &GraphvizData, + intermediate_expressions: &[CoverageKind], + debug_used_expressions: &UsedExpressions, +) { + let mir_source = mir_body.source; + let def_id = mir_source.def_id(); + let node_content = |bcb| { + bcb_to_string_sections( + tcx, + mir_body, + debug_counters, + &basic_coverage_blocks[bcb], + graphviz_data.get_bcb_coverage_spans_with_counters(bcb), + graphviz_data.get_bcb_dependency_counters(bcb), + // intermediate_expressions are injected into the mir::START_BLOCK, so + // include them in the first BCB. + if bcb.index() == 0 { Some(&intermediate_expressions) } else { None }, + ) + }; + let edge_labels = |from_bcb| { + let from_bcb_data = &basic_coverage_blocks[from_bcb]; + let from_terminator = from_bcb_data.terminator(mir_body); + let mut edge_labels = from_terminator.kind.fmt_successor_labels(); + edge_labels.retain(|label| label != "unreachable"); + let edge_counters = from_terminator + .successors() + .map(|successor_bb| graphviz_data.get_edge_counter(from_bcb, successor_bb)); + iter::zip(&edge_labels, edge_counters) + .map(|(label, some_counter)| { + if let Some(counter) = some_counter { + format!("{}\n{}", label, debug_counters.format_counter(counter)) + } else { + label.to_string() + } + }) + .collect::<Vec<_>>() + }; + let graphviz_name = format!("Cov_{}_{}", def_id.krate.index(), def_id.index.index()); + let mut graphviz_writer = + GraphvizWriter::new(basic_coverage_blocks, &graphviz_name, node_content, edge_labels); + let unused_expressions = debug_used_expressions.get_unused_expressions(); + if unused_expressions.len() > 0 { + graphviz_writer.set_graph_label(&format!( + "Unused expressions:\n {}", + unused_expressions + .as_slice() + .iter() + .map(|(counter_kind, edge_from_bcb, target_bcb)| { + if let Some(from_bcb) = edge_from_bcb.as_ref() { + format!( + "{:?}->{:?}: {}", + from_bcb, + target_bcb, + debug_counters.format_counter(&counter_kind), + ) + } else { + format!( + "{:?}: {}", + target_bcb, + debug_counters.format_counter(&counter_kind), + ) + } + }) + .join("\n ") + )); + } + let mut file = create_dump_file(tcx, "dot", None, pass_name, &0, mir_source) + .expect("Unexpected error creating BasicCoverageBlock graphviz DOT file"); + graphviz_writer + .write_graphviz(tcx, &mut file) + .expect("Unexpected error writing BasicCoverageBlock graphviz DOT file"); +} + +fn bcb_to_string_sections<'tcx>( + tcx: TyCtxt<'tcx>, + mir_body: &mir::Body<'tcx>, + debug_counters: &DebugCounters, + bcb_data: &BasicCoverageBlockData, + some_coverage_spans_with_counters: Option<&[(CoverageSpan, CoverageKind)]>, + some_dependency_counters: Option<&[CoverageKind]>, + some_intermediate_expressions: Option<&[CoverageKind]>, +) -> Vec<String> { + let len = bcb_data.basic_blocks.len(); + let mut sections = Vec::new(); + if let Some(collect_intermediate_expressions) = some_intermediate_expressions { + sections.push( + collect_intermediate_expressions + .iter() + .map(|expression| { + format!("Intermediate {}", debug_counters.format_counter(expression)) + }) + .join("\n"), + ); + } + if let Some(coverage_spans_with_counters) = some_coverage_spans_with_counters { + sections.push( + coverage_spans_with_counters + .iter() + .map(|(covspan, counter)| { + format!( + "{} at {}", + debug_counters.format_counter(counter), + covspan.format(tcx, mir_body) + ) + }) + .join("\n"), + ); + } + if let Some(dependency_counters) = some_dependency_counters { + sections.push(format!( + "Non-coverage counters:\n {}", + dependency_counters + .iter() + .map(|counter| debug_counters.format_counter(counter)) + .join(" \n"), + )); + } + if let Some(counter_kind) = &bcb_data.counter_kind { + sections.push(format!("{:?}", counter_kind)); + } + let non_term_blocks = bcb_data.basic_blocks[0..len - 1] + .iter() + .map(|&bb| format!("{:?}: {}", bb, term_type(&mir_body[bb].terminator().kind))) + .collect::<Vec<_>>(); + if non_term_blocks.len() > 0 { + sections.push(non_term_blocks.join("\n")); + } + sections.push(format!( + "{:?}: {}", + bcb_data.basic_blocks.last().unwrap(), + term_type(&bcb_data.terminator(mir_body).kind) + )); + sections +} + +/// Returns a simple string representation of a `TerminatorKind` variant, independent of any +/// values it might hold. +pub(super) fn term_type(kind: &TerminatorKind<'_>) -> &'static str { + match kind { + TerminatorKind::Goto { .. } => "Goto", + TerminatorKind::SwitchInt { .. } => "SwitchInt", + TerminatorKind::Resume => "Resume", + TerminatorKind::Abort => "Abort", + TerminatorKind::Return => "Return", + TerminatorKind::Unreachable => "Unreachable", + TerminatorKind::Drop { .. } => "Drop", + TerminatorKind::DropAndReplace { .. } => "DropAndReplace", + TerminatorKind::Call { .. } => "Call", + TerminatorKind::Assert { .. } => "Assert", + TerminatorKind::Yield { .. } => "Yield", + TerminatorKind::GeneratorDrop => "GeneratorDrop", + TerminatorKind::FalseEdge { .. } => "FalseEdge", + TerminatorKind::FalseUnwind { .. } => "FalseUnwind", + TerminatorKind::InlineAsm { .. } => "InlineAsm", + } +} |