diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs | 148 |
1 files changed, 105 insertions, 43 deletions
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index cee704a9c22..8edd788ee36 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -1,18 +1,23 @@ -use std::ffi::CStr; +use std::ffi::CString; use itertools::Itertools as _; -use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, ConstCodegenMethods}; +use rustc_abi::Align; +use rustc_codegen_ssa::traits::{ + BaseTypeCodegenMethods, ConstCodegenMethods, StaticCodegenMethods, +}; use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_index::IndexVec; +use rustc_middle::mir::coverage::MappingKind; use rustc_middle::ty::{self, TyCtxt}; use rustc_middle::{bug, mir}; use rustc_span::Symbol; use rustc_span::def_id::DefIdSet; +use rustc_target::spec::HasTargetSpec; use tracing::debug; use crate::common::CodegenCx; -use crate::coverageinfo::ffi::CounterMappingRegion; +use crate::coverageinfo::ffi; use crate::coverageinfo::map_data::{FunctionCoverage, FunctionCoverageCollector}; use crate::{coverageinfo, llvm}; @@ -49,11 +54,7 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { add_unused_functions(cx); } - let function_coverage_map = match cx.coverage_context() { - Some(ctx) => ctx.take_function_coverage_map(), - None => return, - }; - + let function_coverage_map = cx.coverage_cx().take_function_coverage_map(); if function_coverage_map.is_empty() { // This module has no functions with coverage instrumentation return; @@ -77,11 +78,9 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { // Generate the coverage map header, which contains the filenames used by // this CGU's coverage mappings, and store it in a well-known global. - let cov_data_val = generate_coverage_map(cx, covmap_version, filenames_size, filenames_val); - coverageinfo::save_cov_data_to_mod(cx, cov_data_val); + generate_covmap_record(cx, covmap_version, filenames_size, filenames_val); let mut unused_function_names = Vec::new(); - let covfun_section_name = coverageinfo::covfun_section_name(cx); // Encode coverage mappings and generate function records for (instance, function_coverage) in function_coverage_entries { @@ -110,9 +109,8 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { unused_function_names.push(mangled_function_name); } - save_function_record( + generate_covfun_record( cx, - &covfun_section_name, mangled_function_name, source_hash, filenames_ref, @@ -237,7 +235,10 @@ fn encode_mappings_for_function( let expressions = function_coverage.counter_expressions().collect::<Vec<_>>(); let mut virtual_file_mapping = VirtualFileMapping::default(); - let mut mapping_regions = Vec::with_capacity(counter_regions.len()); + let mut code_regions = vec![]; + let mut branch_regions = vec![]; + let mut mcdc_branch_regions = vec![]; + let mut mcdc_decision_regions = vec![]; // Group mappings into runs with the same filename, preserving the order // yielded by `FunctionCoverage`. @@ -257,11 +258,36 @@ fn encode_mappings_for_function( // form suitable for FFI. for (mapping_kind, region) in counter_regions_for_file { debug!("Adding counter {mapping_kind:?} to map for {region:?}"); - mapping_regions.push(CounterMappingRegion::from_mapping( - &mapping_kind, - local_file_id.as_u32(), - region, - )); + let span = ffi::CoverageSpan::from_source_region(local_file_id.as_u32(), region); + match mapping_kind { + MappingKind::Code(term) => { + code_regions + .push(ffi::CodeRegion { span, counter: ffi::Counter::from_term(term) }); + } + MappingKind::Branch { true_term, false_term } => { + branch_regions.push(ffi::BranchRegion { + span, + true_counter: ffi::Counter::from_term(true_term), + false_counter: ffi::Counter::from_term(false_term), + }); + } + MappingKind::MCDCBranch { true_term, false_term, mcdc_params } => { + mcdc_branch_regions.push(ffi::MCDCBranchRegion { + span, + true_counter: ffi::Counter::from_term(true_term), + false_counter: ffi::Counter::from_term(false_term), + mcdc_branch_params: ffi::mcdc::BranchParameters::from(mcdc_params), + }); + } + MappingKind::MCDCDecision(mcdc_decision_params) => { + mcdc_decision_regions.push(ffi::MCDCDecisionRegion { + span, + mcdc_decision_params: ffi::mcdc::DecisionParameters::from( + mcdc_decision_params, + ), + }); + } + } } } @@ -270,21 +296,24 @@ fn encode_mappings_for_function( coverageinfo::write_mapping_to_buffer( virtual_file_mapping.into_vec(), expressions, - mapping_regions, + &code_regions, + &branch_regions, + &mcdc_branch_regions, + &mcdc_decision_regions, 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>( +/// Generates the contents of the covmap record for this CGU, which mostly +/// consists of a header and a list of filenames. The record is then stored +/// as a global variable in the `__llvm_covmap` section. +fn generate_covmap_record<'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, @@ -299,15 +328,37 @@ fn generate_coverage_map<'ll>( ); // Create the complete LLVM coverage data value to add to the LLVM IR - cx.const_struct(&[cov_data_header_val, filenames_val], /*packed=*/ false) + let covmap_data = + cx.const_struct(&[cov_data_header_val, filenames_val], /*packed=*/ false); + + let covmap_var_name = CString::new(llvm::build_byte_buffer(|s| unsafe { + llvm::LLVMRustCoverageWriteMappingVarNameToString(s); + })) + .unwrap(); + debug!("covmap var name: {:?}", covmap_var_name); + + let covmap_section_name = CString::new(llvm::build_byte_buffer(|s| unsafe { + llvm::LLVMRustCoverageWriteMapSectionNameToString(cx.llmod, s); + })) + .expect("covmap section name should not contain NUL"); + debug!("covmap section name: {:?}", covmap_section_name); + + let llglobal = llvm::add_global(cx.llmod, cx.val_ty(covmap_data), &covmap_var_name); + llvm::set_initializer(llglobal, covmap_data); + llvm::set_global_constant(llglobal, true); + llvm::set_linkage(llglobal, llvm::Linkage::PrivateLinkage); + llvm::set_section(llglobal, &covmap_section_name); + // LLVM's coverage mapping format specifies 8-byte alignment for items in this section. + // <https://llvm.org/docs/CoverageMappingFormat.html> + llvm::set_alignment(llglobal, Align::EIGHT); + cx.add_used_global(llglobal); } -/// Construct a function record and combine it with the function's coverage mapping data. -/// Save the function record into the LLVM IR as a static global using a -/// specific, well-known section and name. -fn save_function_record( +/// Generates the contents of the covfun record for this function, which +/// contains the function's coverage mapping data. The record is then stored +/// as a global variable in the `__llvm_covfun` section. +fn generate_covfun_record( cx: &CodegenCx<'_, '_>, - covfun_section_name: &CStr, mangled_function_name: &str, source_hash: u64, filenames_ref: u64, @@ -334,13 +385,28 @@ fn save_function_record( /*packed=*/ true, ); - coverageinfo::save_func_record_to_mod( - cx, - covfun_section_name, - func_name_hash, - func_record_val, - is_used, - ); + // Choose a variable name to hold this function's covfun data. + // Functions that are used have a suffix ("u") to distinguish them from + // unused copies of the same function (from different CGUs), so that if a + // linker sees both it won't discard the used copy's data. + let func_record_var_name = + CString::new(format!("__covrec_{:X}{}", func_name_hash, if is_used { "u" } else { "" })) + .unwrap(); + debug!("function record var name: {:?}", func_record_var_name); + + let llglobal = llvm::add_global(cx.llmod, cx.val_ty(func_record_val), &func_record_var_name); + llvm::set_initializer(llglobal, func_record_val); + llvm::set_global_constant(llglobal, true); + llvm::set_linkage(llglobal, llvm::Linkage::LinkOnceODRLinkage); + llvm::set_visibility(llglobal, llvm::Visibility::Hidden); + llvm::set_section(llglobal, cx.covfun_section_name()); + // LLVM's coverage mapping format specifies 8-byte alignment for items in this section. + // <https://llvm.org/docs/CoverageMappingFormat.html> + llvm::set_alignment(llglobal, Align::EIGHT); + if cx.target_spec().supports_comdat() { + llvm::set_comdat(cx.llmod, llglobal, &func_record_var_name); + } + cx.add_used_global(llglobal); } /// Each CGU will normally only emit coverage metadata for the functions that it actually generates. @@ -472,9 +538,5 @@ fn add_unused_function_coverage<'tcx>( // zero, because none of its counters/expressions are marked as seen. let function_coverage = FunctionCoverageCollector::unused(instance, function_coverage_info); - if let Some(coverage_context) = cx.coverage_context() { - coverage_context.function_coverage_map.borrow_mut().insert(instance, function_coverage); - } else { - bug!("Could not get the `coverage_context`"); - } + cx.coverage_cx().function_coverage_map.borrow_mut().insert(instance, function_coverage); } |