diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/coverageinfo')
3 files changed, 53 insertions, 51 deletions
diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index 8c9dfcfd18c..d1cb95507d9 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -1,3 +1,4 @@ +use std::assert_matches::assert_matches; use std::sync::Arc; use itertools::Itertools; @@ -5,6 +6,7 @@ use rustc_abi::Align; use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, ConstCodegenMethods}; use rustc_data_structures::fx::FxIndexMap; use rustc_index::IndexVec; +use rustc_macros::TryFromU32; use rustc_middle::ty::TyCtxt; use rustc_session::RemapFileNameExt; use rustc_session::config::RemapPathScopeComponents; @@ -20,6 +22,23 @@ mod covfun; mod spans; mod unused; +/// Version number that will be included the `__llvm_covmap` section header. +/// Corresponds to LLVM's `llvm::coverage::CovMapVersion` (in `CoverageMapping.h`), +/// or at least the subset that we know and care about. +/// +/// Note that version `n` is encoded as `(n-1)`. +#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, TryFromU32)] +enum CovmapVersion { + /// Used by LLVM 18 onwards. + Version7 = 6, +} + +impl CovmapVersion { + fn to_u32(self) -> u32 { + self as u32 + } +} + /// Generates and exports the coverage map, which is embedded in special /// linker sections in the final binary. /// @@ -29,19 +48,13 @@ pub(crate) fn finalize(cx: &mut CodegenCx<'_, '_>) { let tcx = cx.tcx; // Ensure that LLVM is using a version of the coverage mapping format that - // agrees with our Rust-side code. Expected versions (encoded as n-1) are: - // - `CovMapVersion::Version7` (6) used by LLVM 18-19 - let covmap_version = { - let llvm_covmap_version = llvm_cov::mapping_version(); - let expected_versions = 6..=6; - assert!( - expected_versions.contains(&llvm_covmap_version), - "Coverage mapping version exposed by `llvm-wrapper` is out of sync; \ - expected {expected_versions:?} but was {llvm_covmap_version}" - ); - // This is the version number that we will embed in the covmap section: - llvm_covmap_version - }; + // agrees with our Rust-side code. Expected versions are: + // - `Version7` (6) used by LLVM 18 onwards. + let covmap_version = + CovmapVersion::try_from(llvm_cov::mapping_version()).unwrap_or_else(|raw_version: u32| { + panic!("unknown coverage mapping version reported by `llvm-wrapper`: {raw_version}") + }); + assert_matches!(covmap_version, CovmapVersion::Version7); debug!("Generating coverage map for CodegenUnit: `{}`", cx.codegen_unit.name()); @@ -201,7 +214,11 @@ impl VirtualFileMapping { /// 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: &mut CodegenCx<'ll, '_>, version: u32, filenames_buffer: &[u8]) { +fn generate_covmap_record<'ll>( + cx: &mut CodegenCx<'ll, '_>, + version: CovmapVersion, + filenames_buffer: &[u8], +) { // A covmap record consists of four target-endian u32 values, followed by // the encoded filenames table. Two of the header fields are unused in // modern versions of the LLVM coverage mapping format, and are always 0. @@ -212,7 +229,7 @@ fn generate_covmap_record<'ll>(cx: &mut CodegenCx<'ll, '_>, version: u32, filena cx.const_u32(0), // (unused) cx.const_u32(filenames_buffer.len() as u32), cx.const_u32(0), // (unused) - cx.const_u32(version), + cx.const_u32(version.to_u32()), ], /* packed */ false, ); diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs index b704cf2b1cd..fd1e7f7f160 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs @@ -27,6 +27,9 @@ use crate::llvm; /// the final record that will be embedded in the `__llvm_covfun` section. #[derive(Debug)] pub(crate) struct CovfunRecord<'tcx> { + /// Not used directly, but helpful in debug messages. + _instance: Instance<'tcx>, + mangled_function_name: &'tcx str, source_hash: u64, is_used: bool, @@ -55,6 +58,7 @@ pub(crate) fn prepare_covfun_record<'tcx>( let expressions = prepare_expressions(ids_info); let mut covfun = CovfunRecord { + _instance: instance, mangled_function_name: tcx.symbol_name(instance).name, source_hash: if is_used { fn_cov_info.function_source_hash } else { 0 }, is_used, @@ -102,11 +106,21 @@ fn fill_region_tables<'tcx>( ids_info: &'tcx CoverageIdsInfo, covfun: &mut CovfunRecord<'tcx>, ) { + // If this function is unused, replace all counters with zero. + let counter_for_bcb = |bcb: BasicCoverageBlock| -> ffi::Counter { + let term = if covfun.is_used { + ids_info.term_for_bcb[bcb].expect("every BCB in a mapping was given a term") + } else { + CovTerm::Zero + }; + ffi::Counter::from_term(term) + }; + // Currently a function's mappings must all be in the same file, so use the // first mapping's span to determine the file. let source_map = tcx.sess.source_map(); let Some(first_span) = (try { fn_cov_info.mappings.first()?.span }) else { - debug_assert!(false, "function has no mappings: {:?}", covfun.mangled_function_name); + debug_assert!(false, "function has no mappings: {covfun:?}"); return; }; let source_file = source_map.lookup_source_file(first_span.lo()); @@ -117,7 +131,7 @@ fn fill_region_tables<'tcx>( // codegen needs to handle that gracefully to avoid #133606. // It's hard for tests to trigger this organically, so instead we set // `-Zcoverage-options=discard-all-spans-in-codegen` to force it to occur. - let discard_all = tcx.sess.coverage_discard_all_spans_in_codegen(); + let discard_all = tcx.sess.coverage_options().discard_all_spans_in_codegen; let make_coords = |span: Span| { if discard_all { None } else { spans::make_coords(source_map, &source_file, span) } }; @@ -133,16 +147,6 @@ fn fill_region_tables<'tcx>( // For each counter/region pair in this function+file, convert it to a // form suitable for FFI. for &Mapping { ref kind, span } in &fn_cov_info.mappings { - // If this function is unused, replace all counters with zero. - let counter_for_bcb = |bcb: BasicCoverageBlock| -> ffi::Counter { - let term = if covfun.is_used { - ids_info.term_for_bcb[bcb].expect("every BCB in a mapping was given a term") - } else { - CovTerm::Zero - }; - ffi::Counter::from_term(term) - }; - let Some(coords) = make_coords(span) else { continue }; let cov_span = coords.make_coverage_span(local_file_id); @@ -184,6 +188,7 @@ pub(crate) fn generate_covfun_record<'tcx>( covfun: &CovfunRecord<'tcx>, ) { let &CovfunRecord { + _instance, mangled_function_name, source_hash, is_used, diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs index 39a59560c9d..574463be7ff 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs @@ -39,7 +39,10 @@ impl Coords { /// or other expansions), and if it does happen then skipping a span or function is /// better than an ICE or `llvm-cov` failure that the user might have no way to avoid. pub(crate) fn make_coords(source_map: &SourceMap, file: &SourceFile, span: Span) -> Option<Coords> { - let span = ensure_non_empty_span(source_map, span)?; + if span.is_empty() { + debug_assert!(false, "can't make coords from empty span: {span:?}"); + return None; + } let lo = span.lo(); let hi = span.hi(); @@ -70,29 +73,6 @@ pub(crate) fn make_coords(source_map: &SourceMap, file: &SourceFile, span: Span) }) } -fn ensure_non_empty_span(source_map: &SourceMap, span: Span) -> Option<Span> { - if !span.is_empty() { - return Some(span); - } - - // The span is empty, so try to enlarge it to cover an adjacent '{' or '}'. - source_map - .span_to_source(span, |src, start, end| try { - // Adjusting span endpoints by `BytePos(1)` is normally a bug, - // but in this case we have specifically checked that the character - // we're skipping over is one of two specific ASCII characters, so - // adjusting by exactly 1 byte is correct. - if src.as_bytes().get(end).copied() == Some(b'{') { - Some(span.with_hi(span.hi() + BytePos(1))) - } else if start > 0 && src.as_bytes()[start - 1] == b'}' { - Some(span.with_lo(span.lo() - BytePos(1))) - } else { - None - } - }) - .ok()? -} - /// If `llvm-cov` sees a source region that is improperly ordered (end < start), /// it will immediately exit with a fatal error. To prevent that from happening, /// discard regions that are improperly ordered, or might be interpreted in a |