diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-30 18:31:44 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-30 18:31:44 +0000 |
commit | c23a457e72abe608715ac76f076f47dc42af07a5 (patch) | |
tree | 2772049aaf84b5c9d0ed12ec8d86812f7a7904b6 /compiler/rustc_codegen_llvm/src/coverageinfo | |
parent | Releasing progress-linux version 1.73.0+dfsg1-1~progress7.99u1. (diff) | |
download | rustc-c23a457e72abe608715ac76f076f47dc42af07a5.tar.xz rustc-c23a457e72abe608715ac76f076f47dc42af07a5.zip |
Merging upstream version 1.74.1+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/coverageinfo')
-rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs | 46 | ||||
-rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs | 248 | ||||
-rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs | 200 | ||||
-rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs | 169 |
4 files changed, 280 insertions, 383 deletions
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs index 7a82d05ce..763186a58 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs @@ -1,4 +1,4 @@ -use rustc_middle::mir::coverage::{CounterId, MappedExpressionIndex}; +use rustc_middle::mir::coverage::{CounterId, ExpressionId, Operand}; /// Must match the layout of `LLVMRustCounterKind`. #[derive(Copy, Clone, Debug)] @@ -30,11 +30,8 @@ pub struct Counter { } impl Counter { - /// Constructs a new `Counter` of kind `Zero`. For this `CounterKind`, the - /// `id` is not used. - pub fn zero() -> Self { - Self { kind: CounterKind::Zero, id: 0 } - } + /// A `Counter` of kind `Zero`. For this counter kind, the `id` is not used. + pub(crate) const ZERO: Self = Self { kind: CounterKind::Zero, id: 0 }; /// Constructs a new `Counter` of kind `CounterValueReference`. pub fn counter_value_reference(counter_id: CounterId) -> Self { @@ -42,20 +39,16 @@ impl Counter { } /// Constructs a new `Counter` of kind `Expression`. - pub fn expression(mapped_expression_index: MappedExpressionIndex) -> Self { - Self { kind: CounterKind::Expression, id: mapped_expression_index.into() } - } - - /// Returns true if the `Counter` kind is `Zero`. - pub fn is_zero(&self) -> bool { - matches!(self.kind, CounterKind::Zero) + pub(crate) fn expression(expression_id: ExpressionId) -> Self { + Self { kind: CounterKind::Expression, id: expression_id.as_u32() } } - /// An explicitly-named function to get the ID value, making it more obvious - /// that the stored value is now 0-based. - pub fn zero_based_id(&self) -> u32 { - debug_assert!(!self.is_zero(), "`id` is undefined for CounterKind::Zero"); - self.id + pub(crate) fn from_operand(operand: Operand) -> Self { + match operand { + Operand::Zero => Self::ZERO, + Operand::Counter(id) => Self::counter_value_reference(id), + Operand::Expression(id) => Self::expression(id), + } } } @@ -81,6 +74,11 @@ pub struct CounterExpression { } impl CounterExpression { + /// The dummy expression `(0 - 0)` has a representation of all zeroes, + /// making it marginally more efficient to initialize than `(0 + 0)`. + pub(crate) const DUMMY: Self = + Self { lhs: Counter::ZERO, kind: ExprKind::Subtract, rhs: Counter::ZERO }; + pub fn new(lhs: Counter, kind: ExprKind, rhs: Counter) -> Self { Self { kind, lhs, rhs } } @@ -172,7 +170,7 @@ impl CounterMappingRegion { ) -> Self { Self { counter, - false_counter: Counter::zero(), + false_counter: Counter::ZERO, file_id, expanded_file_id: 0, start_line, @@ -220,8 +218,8 @@ impl CounterMappingRegion { end_col: u32, ) -> Self { Self { - counter: Counter::zero(), - false_counter: Counter::zero(), + counter: Counter::ZERO, + false_counter: Counter::ZERO, file_id, expanded_file_id, start_line, @@ -243,8 +241,8 @@ impl CounterMappingRegion { end_col: u32, ) -> Self { Self { - counter: Counter::zero(), - false_counter: Counter::zero(), + counter: Counter::ZERO, + false_counter: Counter::ZERO, file_id, expanded_file_id: 0, start_line, @@ -268,7 +266,7 @@ impl CounterMappingRegion { ) -> Self { Self { counter, - false_counter: Counter::zero(), + false_counter: Counter::ZERO, file_id, expanded_file_id: 0, start_line, diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs index f1e68af25..e83110dca 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs @@ -1,10 +1,8 @@ use crate::coverageinfo::ffi::{Counter, CounterExpression, ExprKind}; -use rustc_index::{IndexSlice, IndexVec}; -use rustc_middle::bug; -use rustc_middle::mir::coverage::{ - CodeRegion, CounterId, ExpressionId, MappedExpressionIndex, Op, Operand, -}; +use rustc_data_structures::fx::FxIndexSet; +use rustc_index::IndexVec; +use rustc_middle::mir::coverage::{CodeRegion, CounterId, ExpressionId, Op, Operand}; use rustc_middle::ty::Instance; use rustc_middle::ty::TyCtxt; @@ -128,6 +126,58 @@ impl<'tcx> FunctionCoverage<'tcx> { self.unreachable_regions.push(region) } + /// Perform some simplifications to make the final coverage mappings + /// slightly smaller. + /// + /// This method mainly exists to preserve the simplifications that were + /// already being performed by the Rust-side expression renumbering, so that + /// the resulting coverage mappings don't get worse. + pub(crate) fn simplify_expressions(&mut self) { + // The set of expressions that either were optimized out entirely, or + // have zero as both of their operands, and will therefore always have + // a value of zero. Other expressions that refer to these as operands + // can have those operands replaced with `Operand::Zero`. + let mut zero_expressions = FxIndexSet::default(); + + // For each expression, perform simplifications based on lower-numbered + // expressions, and then update the set of always-zero expressions if + // necessary. + // (By construction, expressions can only refer to other expressions + // that have lower IDs, so one simplification pass is sufficient.) + for (id, maybe_expression) in self.expressions.iter_enumerated_mut() { + let Some(expression) = maybe_expression else { + // If an expression is missing, it must have been optimized away, + // so any operand that refers to it can be replaced with zero. + zero_expressions.insert(id); + continue; + }; + + // If an operand refers to an expression that is always zero, then + // that operand can be replaced with `Operand::Zero`. + let maybe_set_operand_to_zero = |operand: &mut Operand| match &*operand { + Operand::Expression(id) if zero_expressions.contains(id) => { + *operand = Operand::Zero; + } + _ => (), + }; + maybe_set_operand_to_zero(&mut expression.lhs); + maybe_set_operand_to_zero(&mut expression.rhs); + + // Coverage counter values cannot be negative, so if an expression + // involves subtraction from zero, assume that its RHS must also be zero. + // (Do this after simplifications that could set the LHS to zero.) + if let Expression { lhs: Operand::Zero, op: Op::Subtract, .. } = expression { + expression.rhs = Operand::Zero; + } + + // After the above simplifications, if both operands are zero, then + // we know that this expression is always zero too. + if let Expression { lhs: Operand::Zero, rhs: Operand::Zero, .. } = expression { + zero_expressions.insert(id); + } + } + } + /// Return the source hash, generated from the HIR node structure, and used to indicate whether /// or not the source code structure changed between different compilations. pub fn source_hash(&self) -> u64 { @@ -146,8 +196,14 @@ impl<'tcx> FunctionCoverage<'tcx> { self.instance ); + let counter_expressions = self.counter_expressions(); + // Expression IDs are indices into `self.expressions`, and on the LLVM + // side they will be treated as indices into `counter_expressions`, so + // the two vectors should correspond 1:1. + assert_eq!(self.expressions.len(), counter_expressions.len()); + let counter_regions = self.counter_regions(); - let (counter_expressions, expression_regions) = self.expressions_with_regions(); + let expression_regions = self.expression_regions(); let unreachable_regions = self.unreachable_regions(); let counter_regions = @@ -163,149 +219,53 @@ impl<'tcx> FunctionCoverage<'tcx> { }) } - fn expressions_with_regions( - &self, - ) -> (Vec<CounterExpression>, impl Iterator<Item = (Counter, &CodeRegion)>) { - let mut counter_expressions = Vec::with_capacity(self.expressions.len()); - let mut expression_regions = Vec::with_capacity(self.expressions.len()); - let mut new_indexes = IndexVec::from_elem_n(None, self.expressions.len()); + /// Convert this function's coverage expression data into a form that can be + /// passed through FFI to LLVM. + fn counter_expressions(&self) -> Vec<CounterExpression> { + // We know that LLVM will optimize out any unused expressions before + // producing the final coverage map, so there's no need to do the same + // thing on the Rust side unless we're confident we can do much better. + // (See `CounterExpressionsMinimizer` in `CoverageMappingWriter.cpp`.) - // This closure converts any `Expression` operand (`lhs` or `rhs` of the `Op::Add` or - // `Op::Subtract` operation) into its native `llvm::coverage::Counter::CounterKind` type - // and value. - // - // Expressions will be returned from this function in a sequential vector (array) of - // `CounterExpression`, so the expression IDs must be mapped from their original, - // potentially sparse set of indexes. - // - // An `Expression` as an operand will have already been encountered as an `Expression` with - // operands, so its new_index will already have been generated (as a 1-up index value). - // (If an `Expression` as an operand does not have a corresponding new_index, it was - // probably optimized out, after the expression was injected into the MIR, so it will - // get a `CounterKind::Zero` instead.) - // - // In other words, an `Expression`s at any given index can include other expressions as - // operands, but expression operands can only come from the subset of expressions having - // `expression_index`s lower than the referencing `Expression`. Therefore, it is - // reasonable to look up the new index of an expression operand while the `new_indexes` - // vector is only complete up to the current `ExpressionIndex`. - type NewIndexes = IndexSlice<ExpressionId, Option<MappedExpressionIndex>>; - let id_to_counter = |new_indexes: &NewIndexes, operand: Operand| match operand { - Operand::Zero => Some(Counter::zero()), - Operand::Counter(id) => Some(Counter::counter_value_reference(id)), - Operand::Expression(id) => { - self.expressions - .get(id) - .expect("expression id is out of range") - .as_ref() - // If an expression was optimized out, assume it would have produced a count - // of zero. This ensures that expressions dependent on optimized-out - // expressions are still valid. - .map_or(Some(Counter::zero()), |_| new_indexes[id].map(Counter::expression)) - } - }; - - for (original_index, expression) in - self.expressions.iter_enumerated().filter_map(|(original_index, entry)| { - // Option::map() will return None to filter out missing expressions. This may happen - // if, for example, a MIR-instrumented expression is removed during an optimization. - entry.as_ref().map(|expression| (original_index, expression)) - }) - { - let optional_region = &expression.region; - let Expression { lhs, op, rhs, .. } = *expression; - - if let Some(Some((lhs_counter, mut rhs_counter))) = id_to_counter(&new_indexes, lhs) - .map(|lhs_counter| { - id_to_counter(&new_indexes, rhs).map(|rhs_counter| (lhs_counter, rhs_counter)) - }) - { - if lhs_counter.is_zero() && op.is_subtract() { - // The left side of a subtraction was probably optimized out. As an example, - // a branch condition might be evaluated as a constant expression, and the - // branch could be removed, dropping unused counters in the process. - // - // Since counters are unsigned, we must assume the result of the expression - // can be no more and no less than zero. An expression known to evaluate to zero - // does not need to be added to the coverage map. - // - // Coverage test `loops_branches.rs` includes multiple variations of branches - // based on constant conditional (literal `true` or `false`), and demonstrates - // that the expected counts are still correct. - debug!( - "Expression subtracts from zero (assume unreachable): \ - original_index={:?}, lhs={:?}, op={:?}, rhs={:?}, region={:?}", - original_index, lhs, op, rhs, optional_region, - ); - rhs_counter = Counter::zero(); + self.expressions + .iter() + .map(|expression| match expression { + None => { + // This expression ID was allocated, but we never saw the + // actual expression, so it must have been optimized out. + // Replace it with a dummy expression, and let LLVM take + // care of omitting it from the expression list. + CounterExpression::DUMMY } - debug_assert!( - lhs_counter.is_zero() - // Note: with `as usize` the ID _could_ overflow/wrap if `usize = u16` - || ((lhs_counter.zero_based_id() as usize) - <= usize::max(self.counters.len(), self.expressions.len())), - "lhs id={} > both counters.len()={} and expressions.len()={} - ({:?} {:?} {:?})", - lhs_counter.zero_based_id(), - self.counters.len(), - self.expressions.len(), - lhs_counter, - op, - rhs_counter, - ); - - debug_assert!( - rhs_counter.is_zero() - // Note: with `as usize` the ID _could_ overflow/wrap if `usize = u16` - || ((rhs_counter.zero_based_id() as usize) - <= usize::max(self.counters.len(), self.expressions.len())), - "rhs id={} > both counters.len()={} and expressions.len()={} - ({:?} {:?} {:?})", - rhs_counter.zero_based_id(), - self.counters.len(), - self.expressions.len(), - lhs_counter, - op, - rhs_counter, - ); - - // Both operands exist. `Expression` operands exist in `self.expressions` and have - // been assigned a `new_index`. - let mapped_expression_index = - MappedExpressionIndex::from(counter_expressions.len()); - let expression = CounterExpression::new( - lhs_counter, - match op { - Op::Add => ExprKind::Add, - Op::Subtract => ExprKind::Subtract, - }, - rhs_counter, - ); - debug!( - "Adding expression {:?} = {:?}, region: {:?}", - mapped_expression_index, expression, optional_region - ); - counter_expressions.push(expression); - new_indexes[original_index] = Some(mapped_expression_index); - if let Some(region) = optional_region { - expression_regions.push((Counter::expression(mapped_expression_index), region)); + &Some(Expression { lhs, op, rhs, .. }) => { + // Convert the operands and operator as normal. + CounterExpression::new( + Counter::from_operand(lhs), + match op { + Op::Add => ExprKind::Add, + Op::Subtract => ExprKind::Subtract, + }, + Counter::from_operand(rhs), + ) } - } else { - bug!( - "expression has one or more missing operands \ - original_index={:?}, lhs={:?}, op={:?}, rhs={:?}, region={:?}", - original_index, - lhs, - op, - rhs, - optional_region, - ); - } - } - (counter_expressions, expression_regions.into_iter()) + }) + .collect::<Vec<_>>() + } + + fn expression_regions(&self) -> Vec<(Counter, &CodeRegion)> { + // Find all of the expression IDs that weren't optimized out AND have + // an attached code region, and return the corresponding mapping as a + // counter/region pair. + self.expressions + .iter_enumerated() + .filter_map(|(id, expression)| { + let code_region = expression.as_ref()?.region.as_ref()?; + Some((Counter::expression(id), code_region)) + }) + .collect::<Vec<_>>() } fn unreachable_regions(&self) -> impl Iterator<Item = (Counter, &CodeRegion)> { - self.unreachable_regions.iter().map(|region| (Counter::zero(), region)) + self.unreachable_regions.iter().map(|region| (Counter::ZERO, region)) } } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index 97a99e510..d4e775256 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -1,13 +1,14 @@ use crate::common::CodegenCx; use crate::coverageinfo; -use crate::coverageinfo::ffi::{Counter, CounterExpression, CounterMappingRegion}; +use crate::coverageinfo::ffi::CounterMappingRegion; +use crate::coverageinfo::map_data::FunctionCoverage; use crate::llvm; use rustc_codegen_ssa::traits::ConstMethods; use rustc_data_structures::fx::FxIndexSet; use rustc_hir::def::DefKind; use rustc_hir::def_id::DefId; -use rustc_llvm::RustString; +use rustc_index::IndexVec; use rustc_middle::bug; use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags; use rustc_middle::mir::coverage::CodeRegion; @@ -55,21 +56,21 @@ pub fn finalize(cx: &CodegenCx<'_, '_>) { return; } - let mut mapgen = CoverageMapGenerator::new(tcx); + let mut global_file_table = GlobalFileTable::new(tcx); // Encode coverage mappings and generate function records let mut function_data = Vec::new(); - for (instance, function_coverage) in function_coverage_map { + for (instance, mut function_coverage) in function_coverage_map { debug!("Generate function coverage for {}, {:?}", cx.codegen_unit.name(), instance); + function_coverage.simplify_expressions(); + let function_coverage = function_coverage; + let mangled_function_name = tcx.symbol_name(instance).name; let source_hash = function_coverage.source_hash(); let is_used = function_coverage.is_used(); - let (expressions, counter_regions) = - function_coverage.get_expressions_and_counter_regions(); - let coverage_mapping_buffer = llvm::build_byte_buffer(|coverage_mapping_buffer| { - mapgen.write_coverage_mapping(expressions, counter_regions, coverage_mapping_buffer); - }); + let coverage_mapping_buffer = + encode_mappings_for_function(&mut global_file_table, &function_coverage); if coverage_mapping_buffer.is_empty() { if function_coverage.is_used() { @@ -87,19 +88,14 @@ pub fn finalize(cx: &CodegenCx<'_, '_>) { } // Encode all filenames referenced by counters/expressions in this module - let filenames_buffer = llvm::build_byte_buffer(|filenames_buffer| { - coverageinfo::write_filenames_section_to_buffer( - mapgen.filenames.iter().map(Symbol::as_str), - filenames_buffer, - ); - }); + let filenames_buffer = global_file_table.into_filenames_buffer(); let filenames_size = filenames_buffer.len(); let filenames_val = cx.const_bytes(&filenames_buffer); let filenames_ref = coverageinfo::hash_bytes(&filenames_buffer); // Generate the LLVM IR representation of the coverage map and store it in a well-known global - let cov_data_val = mapgen.generate_coverage_map(cx, version, filenames_size, filenames_val); + let cov_data_val = generate_coverage_map(cx, version, filenames_size, filenames_val); let covfun_section_name = coverageinfo::covfun_section_name(cx); for (mangled_function_name, source_hash, is_used, coverage_mapping_buffer) in function_data { @@ -118,13 +114,13 @@ pub fn finalize(cx: &CodegenCx<'_, '_>) { coverageinfo::save_cov_data_to_mod(cx, cov_data_val); } -struct CoverageMapGenerator { - filenames: FxIndexSet<Symbol>, +struct GlobalFileTable { + global_file_table: FxIndexSet<Symbol>, } -impl CoverageMapGenerator { +impl GlobalFileTable { fn new(tcx: TyCtxt<'_>) -> Self { - let mut filenames = FxIndexSet::default(); + let mut global_file_table = FxIndexSet::default(); // LLVM Coverage Mapping Format version 6 (zero-based encoded as 5) // requires setting the first filename to the compilation directory. // Since rustc generates coverage maps with relative paths, the @@ -133,94 +129,114 @@ impl CoverageMapGenerator { let working_dir = Symbol::intern( &tcx.sess.opts.working_dir.remapped_path_if_available().to_string_lossy(), ); - filenames.insert(working_dir); - Self { filenames } + global_file_table.insert(working_dir); + Self { global_file_table } } - /// Using the `expressions` and `counter_regions` collected for the current function, generate - /// the `mapping_regions` and `virtual_file_mapping`, and capture any new filenames. Then use - /// LLVM APIs to encode the `virtual_file_mapping`, `expressions`, and `mapping_regions` into - /// the given `coverage_mapping` byte buffer, compliant with the LLVM Coverage Mapping format. - fn write_coverage_mapping<'a>( - &mut self, - expressions: Vec<CounterExpression>, - counter_regions: impl Iterator<Item = (Counter, &'a CodeRegion)>, - coverage_mapping_buffer: &RustString, - ) { - let mut counter_regions = counter_regions.collect::<Vec<_>>(); - if counter_regions.is_empty() { - return; - } + fn global_file_id_for_file_name(&mut self, file_name: Symbol) -> u32 { + let (global_file_id, _) = self.global_file_table.insert_full(file_name); + global_file_id as u32 + } - let mut virtual_file_mapping = Vec::new(); - let mut mapping_regions = Vec::new(); - let mut current_file_name = None; - let mut current_file_id = 0; - - // Convert the list of (Counter, CodeRegion) pairs to an array of `CounterMappingRegion`, sorted - // by filename and position. Capture any new files to compute the `CounterMappingRegion`s - // `file_id` (indexing files referenced by the current function), and construct the - // function-specific `virtual_file_mapping` from `file_id` to its index in the module's - // `filenames` array. - counter_regions.sort_unstable_by_key(|(_counter, region)| *region); - for (counter, region) in counter_regions { - let CodeRegion { file_name, start_line, start_col, end_line, end_col } = *region; - let same_file = current_file_name.is_some_and(|p| p == file_name); - if !same_file { - if current_file_name.is_some() { - current_file_id += 1; - } - current_file_name = Some(file_name); - debug!(" file_id: {} = '{:?}'", current_file_id, file_name); - let (filenames_index, _) = self.filenames.insert_full(file_name); - virtual_file_mapping.push(filenames_index as u32); - } - debug!("Adding counter {:?} to map for {:?}", counter, region); + fn into_filenames_buffer(self) -> Vec<u8> { + // This method takes `self` so that the caller can't accidentally + // modify the original file table after encoding it into a buffer. + + llvm::build_byte_buffer(|buffer| { + coverageinfo::write_filenames_section_to_buffer( + self.global_file_table.iter().map(Symbol::as_str), + buffer, + ); + }) + } +} + +/// Using the expressions and counter regions collected for a single function, +/// generate the variable-sized payload of its corresponding `__llvm_covfun` +/// entry. The payload is returned as a vector of bytes. +/// +/// Newly-encountered filenames will be added to the global file table. +fn encode_mappings_for_function( + global_file_table: &mut GlobalFileTable, + function_coverage: &FunctionCoverage<'_>, +) -> Vec<u8> { + let (expressions, counter_regions) = function_coverage.get_expressions_and_counter_regions(); + + let mut counter_regions = counter_regions.collect::<Vec<_>>(); + if counter_regions.is_empty() { + return Vec::new(); + } + + let mut virtual_file_mapping = IndexVec::<u32, u32>::new(); + let mut mapping_regions = Vec::with_capacity(counter_regions.len()); + + // Sort the list of (counter, region) mapping pairs by region, so that they + // can be grouped by filename. Prepare file IDs for each filename, and + // prepare the mapping data so that we can pass it through FFI to LLVM. + counter_regions.sort_by_key(|(_counter, region)| *region); + for counter_regions_for_file in + counter_regions.group_by(|(_, a), (_, b)| a.file_name == b.file_name) + { + // Look up (or allocate) the global file ID for this filename. + let file_name = counter_regions_for_file[0].1.file_name; + let global_file_id = global_file_table.global_file_id_for_file_name(file_name); + + // Associate that global file ID with a local file ID for this function. + let local_file_id: u32 = virtual_file_mapping.push(global_file_id); + debug!(" file id: local {local_file_id} => global {global_file_id} = '{file_name:?}'"); + + // For each counter/region pair in this function+file, convert it to a + // form suitable for FFI. + for &(counter, region) in counter_regions_for_file { + let CodeRegion { file_name: _, start_line, start_col, end_line, end_col } = *region; + + debug!("Adding counter {counter:?} to map for {region:?}"); mapping_regions.push(CounterMappingRegion::code_region( counter, - current_file_id, + local_file_id, start_line, start_col, end_line, end_col, )); } + } - // Encode and append the current function's coverage mapping data + // Encode the function's coverage mappings into a buffer. + llvm::build_byte_buffer(|buffer| { coverageinfo::write_mapping_to_buffer( - virtual_file_mapping, + virtual_file_mapping.raw, expressions, mapping_regions, - coverage_mapping_buffer, + buffer, ); - } + }) +} - /// Construct coverage map header and the array of function records, and combine them into the - /// coverage map. Save the coverage map data into the LLVM IR as a static global using a - /// specific, well-known section and name. - fn generate_coverage_map<'ll>( - self, - cx: &CodegenCx<'ll, '_>, - version: u32, - filenames_size: usize, - filenames_val: &'ll llvm::Value, - ) -> &'ll llvm::Value { - debug!("cov map: filenames_size = {}, 0-based version = {}", filenames_size, version); - - // Create the coverage data header (Note, fields 0 and 2 are now always zero, - // as of `llvm::coverage::CovMapVersion::Version4`.) - let zero_was_n_records_val = cx.const_u32(0); - let filenames_size_val = cx.const_u32(filenames_size as u32); - let zero_was_coverage_size_val = cx.const_u32(0); - let version_val = cx.const_u32(version); - let cov_data_header_val = cx.const_struct( - &[zero_was_n_records_val, filenames_size_val, zero_was_coverage_size_val, version_val], - /*packed=*/ false, - ); +/// Construct coverage map header and the array of function records, and combine them into the +/// coverage map. Save the coverage map data into the LLVM IR as a static global using a +/// specific, well-known section and name. +fn generate_coverage_map<'ll>( + cx: &CodegenCx<'ll, '_>, + version: u32, + filenames_size: usize, + filenames_val: &'ll llvm::Value, +) -> &'ll llvm::Value { + debug!("cov map: filenames_size = {}, 0-based version = {}", filenames_size, version); + + // Create the coverage data header (Note, fields 0 and 2 are now always zero, + // as of `llvm::coverage::CovMapVersion::Version4`.) + let zero_was_n_records_val = cx.const_u32(0); + let filenames_size_val = cx.const_u32(filenames_size as u32); + let zero_was_coverage_size_val = cx.const_u32(0); + let version_val = cx.const_u32(version); + let cov_data_header_val = cx.const_struct( + &[zero_was_n_records_val, filenames_size_val, zero_was_coverage_size_val, version_val], + /*packed=*/ false, + ); - // Create the complete LLVM coverage data value to add to the LLVM IR - cx.const_struct(&[cov_data_header_val, filenames_val], /*packed=*/ false) - } + // Create the complete LLVM coverage data value to add to the LLVM IR + cx.const_struct(&[cov_data_header_val, filenames_val], /*packed=*/ false) } /// Construct a function record and combine it with the function's coverage mapping data. @@ -317,10 +333,10 @@ fn add_unused_functions(cx: &CodegenCx<'_, '_>) { { let codegen_fn_attrs = tcx.codegen_fn_attrs(non_codegenned_def_id); - // If a function is marked `#[no_coverage]`, then skip generating a + // If a function is marked `#[coverage(off)]`, then skip generating a // dead code stub for it. if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::NO_COVERAGE) { - debug!("skipping unused fn marked #[no_coverage]: {:?}", non_codegenned_def_id); + debug!("skipping unused fn marked #[coverage(off)]: {:?}", non_codegenned_def_id); continue; } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs index 621fd36b2..c70cb670e 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mod.rs @@ -16,7 +16,7 @@ use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_llvm::RustString; use rustc_middle::bug; -use rustc_middle::mir::coverage::{CodeRegion, CounterId, CoverageKind, ExpressionId, Op, Operand}; +use rustc_middle::mir::coverage::{CounterId, CoverageKind}; use rustc_middle::mir::Coverage; use rustc_middle::ty; use rustc_middle::ty::layout::{FnAbiOf, HasTyCtxt}; @@ -104,144 +104,67 @@ impl<'tcx> CoverageInfoBuilderMethods<'tcx> for Builder<'_, '_, 'tcx> { fn add_coverage(&mut self, instance: Instance<'tcx>, coverage: &Coverage) { let bx = self; + let Some(coverage_context) = bx.coverage_context() else { return }; + let mut coverage_map = coverage_context.function_coverage_map.borrow_mut(); + let func_coverage = coverage_map + .entry(instance) + .or_insert_with(|| FunctionCoverage::new(bx.tcx(), instance)); + let Coverage { kind, code_region } = coverage.clone(); match kind { CoverageKind::Counter { function_source_hash, id } => { - if bx.set_function_source_hash(instance, function_source_hash) { - // If `set_function_source_hash()` returned true, the coverage map is enabled, - // so continue adding the counter. - if let Some(code_region) = code_region { - // Note: Some counters do not have code regions, but may still be referenced - // from expressions. In that case, don't add the counter to the coverage map, - // but do inject the counter intrinsic. - bx.add_coverage_counter(instance, id, code_region); - } - - let coverageinfo = bx.tcx().coverageinfo(instance.def); - - let fn_name = bx.get_pgo_func_name_var(instance); - let hash = bx.const_u64(function_source_hash); - let num_counters = bx.const_u32(coverageinfo.num_counters); - let index = bx.const_u32(id.as_u32()); + debug!( + "ensuring function source hash is set for instance={:?}; function_source_hash={}", + instance, function_source_hash, + ); + func_coverage.set_function_source_hash(function_source_hash); + + if let Some(code_region) = code_region { + // Note: Some counters do not have code regions, but may still be referenced + // from expressions. In that case, don't add the counter to the coverage map, + // but do inject the counter intrinsic. debug!( - "codegen intrinsic instrprof.increment(fn_name={:?}, hash={:?}, num_counters={:?}, index={:?})", - fn_name, hash, num_counters, index, + "adding counter to coverage_map: instance={:?}, id={:?}, region={:?}", + instance, id, code_region, ); - bx.instrprof_increment(fn_name, hash, num_counters, index); + func_coverage.add_counter(id, code_region); } + // We need to explicitly drop the `RefMut` before calling into `instrprof_increment`, + // as that needs an exclusive borrow. + drop(coverage_map); + + let coverageinfo = bx.tcx().coverageinfo(instance.def); + + let fn_name = bx.get_pgo_func_name_var(instance); + let hash = bx.const_u64(function_source_hash); + let num_counters = bx.const_u32(coverageinfo.num_counters); + let index = bx.const_u32(id.as_u32()); + debug!( + "codegen intrinsic instrprof.increment(fn_name={:?}, hash={:?}, num_counters={:?}, index={:?})", + fn_name, hash, num_counters, index, + ); + bx.instrprof_increment(fn_name, hash, num_counters, index); } CoverageKind::Expression { id, lhs, op, rhs } => { - bx.add_coverage_counter_expression(instance, id, lhs, op, rhs, code_region); + debug!( + "adding counter expression to coverage_map: instance={:?}, id={:?}, {:?} {:?} {:?}; region: {:?}", + instance, id, lhs, op, rhs, code_region, + ); + func_coverage.add_counter_expression(id, lhs, op, rhs, code_region); } CoverageKind::Unreachable => { - bx.add_coverage_unreachable( - instance, - code_region.expect("unreachable regions always have code regions"), + let code_region = + code_region.expect("unreachable regions always have code regions"); + debug!( + "adding unreachable code to coverage_map: instance={:?}, at {:?}", + instance, code_region, ); + func_coverage.add_unreachable_region(code_region); } } } } -// These methods used to be part of trait `CoverageInfoBuilderMethods`, but -// after moving most coverage code out of SSA they are now just ordinary methods. -impl<'tcx> Builder<'_, '_, 'tcx> { - /// Returns true if the function source hash was added to the coverage map (even if it had - /// already been added, for this instance). Returns false *only* if `-C instrument-coverage` is - /// not enabled (a coverage map is not being generated). - fn set_function_source_hash( - &mut self, - instance: Instance<'tcx>, - function_source_hash: u64, - ) -> bool { - if let Some(coverage_context) = self.coverage_context() { - debug!( - "ensuring function source hash is set for instance={:?}; function_source_hash={}", - instance, function_source_hash, - ); - let mut coverage_map = coverage_context.function_coverage_map.borrow_mut(); - coverage_map - .entry(instance) - .or_insert_with(|| FunctionCoverage::new(self.tcx, instance)) - .set_function_source_hash(function_source_hash); - true - } else { - false - } - } - - /// Returns true if the counter was added to the coverage map; false if `-C instrument-coverage` - /// is not enabled (a coverage map is not being generated). - fn add_coverage_counter( - &mut self, - instance: Instance<'tcx>, - id: CounterId, - region: CodeRegion, - ) -> bool { - if let Some(coverage_context) = self.coverage_context() { - debug!( - "adding counter to coverage_map: instance={:?}, id={:?}, region={:?}", - instance, id, region, - ); - let mut coverage_map = coverage_context.function_coverage_map.borrow_mut(); - coverage_map - .entry(instance) - .or_insert_with(|| FunctionCoverage::new(self.tcx, instance)) - .add_counter(id, region); - true - } else { - false - } - } - - /// Returns true if the expression was added to the coverage map; false if - /// `-C instrument-coverage` is not enabled (a coverage map is not being generated). - fn add_coverage_counter_expression( - &mut self, - instance: Instance<'tcx>, - id: ExpressionId, - lhs: Operand, - op: Op, - rhs: Operand, - region: Option<CodeRegion>, - ) -> bool { - if let Some(coverage_context) = self.coverage_context() { - debug!( - "adding counter expression to coverage_map: instance={:?}, id={:?}, {:?} {:?} {:?}; \ - region: {:?}", - instance, id, lhs, op, rhs, region, - ); - let mut coverage_map = coverage_context.function_coverage_map.borrow_mut(); - coverage_map - .entry(instance) - .or_insert_with(|| FunctionCoverage::new(self.tcx, instance)) - .add_counter_expression(id, lhs, op, rhs, region); - true - } else { - false - } - } - - /// Returns true if the region was added to the coverage map; false if `-C instrument-coverage` - /// is not enabled (a coverage map is not being generated). - fn add_coverage_unreachable(&mut self, instance: Instance<'tcx>, region: CodeRegion) -> bool { - if let Some(coverage_context) = self.coverage_context() { - debug!( - "adding unreachable code to coverage_map: instance={:?}, at {:?}", - instance, region, - ); - let mut coverage_map = coverage_context.function_coverage_map.borrow_mut(); - coverage_map - .entry(instance) - .or_insert_with(|| FunctionCoverage::new(self.tcx, instance)) - .add_unreachable_region(region); - true - } else { - false - } - } -} - fn declare_unused_fn<'tcx>(cx: &CodegenCx<'_, 'tcx>, def_id: DefId) -> Instance<'tcx> { let tcx = cx.tcx; |