diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/asm.rs | 2 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs | 36 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs | 14 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs | 129 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs | 124 | ||||
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/lib.rs | 1 |
6 files changed, 210 insertions, 96 deletions
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs index 6ee80c08d4a..9aa01bd1b95 100644 --- a/compiler/rustc_codegen_llvm/src/asm.rs +++ b/compiler/rustc_codegen_llvm/src/asm.rs @@ -645,6 +645,7 @@ fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'_>>) -> | Arm(ArmInlineAsmRegClass::qreg_low4) => "x", Arm(ArmInlineAsmRegClass::dreg) | Arm(ArmInlineAsmRegClass::qreg) => "w", Hexagon(HexagonInlineAsmRegClass::reg) => "r", + Hexagon(HexagonInlineAsmRegClass::preg) => unreachable!("clobber-only"), LoongArch(LoongArchInlineAsmRegClass::reg) => "r", LoongArch(LoongArchInlineAsmRegClass::freg) => "f", Mips(MipsInlineAsmRegClass::reg) => "r", @@ -813,6 +814,7 @@ fn dummy_output_type<'ll>(cx: &CodegenCx<'ll, '_>, reg: InlineAsmRegClass) -> &' | Arm(ArmInlineAsmRegClass::qreg_low8) | Arm(ArmInlineAsmRegClass::qreg_low4) => cx.type_vector(cx.type_i64(), 2), Hexagon(HexagonInlineAsmRegClass::reg) => cx.type_i32(), + Hexagon(HexagonInlineAsmRegClass::preg) => unreachable!("clobber-only"), LoongArch(LoongArchInlineAsmRegClass::reg) => cx.type_i32(), LoongArch(LoongArchInlineAsmRegClass::freg) => cx.type_f32(), Mips(MipsInlineAsmRegClass::reg) => cx.type_i32(), diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs index a6e07ea2a60..19d6726002c 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/ffi.rs @@ -1,6 +1,4 @@ -use rustc_middle::mir::coverage::{CounterId, CovTerm, ExpressionId, SourceRegion}; - -use crate::coverageinfo::mapgen::LocalFileId; +use rustc_middle::mir::coverage::{CounterId, CovTerm, ExpressionId}; /// Must match the layout of `LLVMRustCounterKind`. #[derive(Copy, Clone, Debug)] @@ -126,37 +124,23 @@ pub(crate) struct CoverageSpan { /// Local index into the function's local-to-global file ID table. /// The value at that index is itself an index into the coverage filename /// table in the CGU's `__llvm_covmap` section. - file_id: u32, + pub(crate) file_id: u32, /// 1-based starting line of the source code span. - start_line: u32, + pub(crate) start_line: u32, /// 1-based starting column of the source code span. - start_col: u32, + pub(crate) start_col: u32, /// 1-based ending line of the source code span. - end_line: u32, + pub(crate) end_line: u32, /// 1-based ending column of the source code span. High bit must be unset. - end_col: u32, -} - -impl CoverageSpan { - pub(crate) fn from_source_region( - local_file_id: LocalFileId, - code_region: &SourceRegion, - ) -> Self { - let file_id = local_file_id.as_u32(); - let &SourceRegion { start_line, start_col, end_line, end_col } = code_region; - // Internally, LLVM uses the high bit of `end_col` to distinguish between - // code regions and gap regions, so it can't be used by the column number. - assert!(end_col & (1u32 << 31) == 0, "high bit of `end_col` must be unset: {end_col:#X}"); - Self { file_id, start_line, start_col, end_line, end_col } - } + pub(crate) end_col: u32, } /// Must match the layout of `LLVMRustCoverageCodeRegion`. #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct CodeRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) counter: Counter, } @@ -164,7 +148,7 @@ pub(crate) struct CodeRegion { #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct BranchRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) true_counter: Counter, pub(crate) false_counter: Counter, } @@ -173,7 +157,7 @@ pub(crate) struct BranchRegion { #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct MCDCBranchRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) true_counter: Counter, pub(crate) false_counter: Counter, pub(crate) mcdc_branch_params: mcdc::BranchParameters, @@ -183,6 +167,6 @@ pub(crate) struct MCDCBranchRegion { #[derive(Clone, Debug)] #[repr(C)] pub(crate) struct MCDCDecisionRegion { - pub(crate) span: CoverageSpan, + pub(crate) cov_span: CoverageSpan, pub(crate) mcdc_decision_params: mcdc::DecisionParameters, } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs index e3c0df27883..95746b88ced 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/map_data.rs @@ -3,9 +3,9 @@ use rustc_data_structures::fx::FxIndexSet; use rustc_index::bit_set::BitSet; use rustc_middle::mir::coverage::{ CounterId, CovTerm, Expression, ExpressionId, FunctionCoverageInfo, Mapping, MappingKind, Op, - SourceRegion, }; use rustc_middle::ty::Instance; +use rustc_span::Span; use tracing::{debug, instrument}; use crate::coverageinfo::ffi::{Counter, CounterExpression, ExprKind}; @@ -220,16 +220,16 @@ impl<'tcx> FunctionCoverage<'tcx> { }) } - /// Converts this function's coverage mappings into an intermediate form - /// that will be used by `mapgen` when preparing for FFI. - pub(crate) fn counter_regions( + /// Yields all this function's coverage mappings, after simplifying away + /// unused counters and counter expressions. + pub(crate) fn mapping_spans( &self, - ) -> impl Iterator<Item = (MappingKind, &SourceRegion)> + ExactSizeIterator { + ) -> impl Iterator<Item = (MappingKind, Span)> + ExactSizeIterator + Captures<'_> { self.function_coverage_info.mappings.iter().map(move |mapping| { - let Mapping { kind, source_region } = mapping; + let &Mapping { ref kind, span } = mapping; let kind = kind.map_terms(|term| if self.is_zero_term(term) { CovTerm::Zero } else { term }); - (kind, source_region) + (kind, span) }) } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index b582dd967a7..ed881418cb0 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -1,12 +1,14 @@ +mod spans; + use std::ffi::CString; -use std::iter; +use std::sync::Arc; use itertools::Itertools as _; use rustc_abi::Align; use rustc_codegen_ssa::traits::{ BaseTypeCodegenMethods, ConstCodegenMethods, StaticCodegenMethods, }; -use rustc_data_structures::fx::{FxHashSet, FxIndexMap, FxIndexSet}; +use rustc_data_structures::fx::{FxHashSet, FxIndexMap}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_index::IndexVec; use rustc_middle::mir::coverage::MappingKind; @@ -15,7 +17,7 @@ use rustc_middle::{bug, mir}; use rustc_session::RemapFileNameExt; use rustc_session::config::RemapPathScopeComponents; use rustc_span::def_id::DefIdSet; -use rustc_span::{Span, Symbol}; +use rustc_span::{SourceFile, StableSourceFileId}; use rustc_target::spec::HasTargetSpec; use tracing::debug; @@ -72,11 +74,11 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { .map(|(instance, function_coverage)| (instance, function_coverage.into_finished())) .collect::<Vec<_>>(); - let all_file_names = function_coverage_entries + let all_files = function_coverage_entries .iter() .map(|(_, fn_cov)| fn_cov.function_coverage_info.body_span) - .map(|span| span_file_name(tcx, span)); - let global_file_table = GlobalFileTable::new(all_file_names); + .map(|span| tcx.sess.source_map().lookup_source_file(span.lo())); + let global_file_table = GlobalFileTable::new(all_files); // Encode all filenames referenced by coverage mappings in this CGU. let filenames_buffer = global_file_table.make_filenames_buffer(tcx); @@ -103,15 +105,8 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { encode_mappings_for_function(tcx, &global_file_table, &function_coverage); if coverage_mapping_buffer.is_empty() { - if function_coverage.is_used() { - bug!( - "A used function should have had coverage mapping data but did not: {}", - mangled_function_name - ); - } else { - debug!("unused function had no coverage mapping data: {}", mangled_function_name); - continue; - } + debug!("function has no mappings to embed; skipping"); + continue; } if !is_used { @@ -148,29 +143,34 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { } } -/// Maps "global" (per-CGU) file ID numbers to their underlying filenames. +/// Maps "global" (per-CGU) file ID numbers to their underlying source files. struct GlobalFileTable { - /// This "raw" table doesn't include the working dir, so a filename's + /// This "raw" table doesn't include the working dir, so a file's /// global ID is its index in this set **plus one**. - raw_file_table: FxIndexSet<Symbol>, + raw_file_table: FxIndexMap<StableSourceFileId, Arc<SourceFile>>, } impl GlobalFileTable { - fn new(all_file_names: impl IntoIterator<Item = Symbol>) -> Self { - // Collect all of the filenames into a set. Filenames usually come in - // contiguous runs, so we can dedup adjacent ones to save work. - let mut raw_file_table = all_file_names.into_iter().dedup().collect::<FxIndexSet<Symbol>>(); + fn new(all_files: impl IntoIterator<Item = Arc<SourceFile>>) -> Self { + // Collect all of the files into a set. Files usually come in contiguous + // runs, so we can dedup adjacent ones to save work. + let mut raw_file_table = all_files + .into_iter() + .dedup_by(|a, b| a.stable_id == b.stable_id) + .map(|f| (f.stable_id, f)) + .collect::<FxIndexMap<StableSourceFileId, Arc<SourceFile>>>(); - // Sort the file table by its actual string values, not the arbitrary - // ordering of its symbols. - raw_file_table.sort_unstable_by(|a, b| a.as_str().cmp(b.as_str())); + // Sort the file table by its underlying filenames. + raw_file_table.sort_unstable_by(|_, a, _, b| { + Ord::cmp(&a.name, &b.name).then_with(|| Ord::cmp(&a.stable_id, &b.stable_id)) + }); Self { raw_file_table } } - fn global_file_id_for_file_name(&self, file_name: Symbol) -> GlobalFileId { - let raw_id = self.raw_file_table.get_index_of(&file_name).unwrap_or_else(|| { - bug!("file name not found in prepared global file table: {file_name}"); + fn global_file_id_for_file(&self, file: &SourceFile) -> GlobalFileId { + let raw_id = self.raw_file_table.get_index_of(&file.stable_id).unwrap_or_else(|| { + bug!("file not found in prepared global file table: {:?}", file.name); }); // The raw file table doesn't include an entry for the working dir // (which has ID 0), so add 1 to get the correct ID. @@ -178,24 +178,27 @@ impl GlobalFileTable { } fn make_filenames_buffer(&self, tcx: TyCtxt<'_>) -> Vec<u8> { + let mut table = Vec::with_capacity(self.raw_file_table.len() + 1); + // 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 // compilation directory can be combined with the relative paths // to get absolute paths, if needed. - use rustc_session::RemapFileNameExt; - use rustc_session::config::RemapPathScopeComponents; - let working_dir: &str = &tcx - .sess - .opts - .working_dir - .for_scope(tcx.sess, RemapPathScopeComponents::MACRO) - .to_string_lossy(); - - // Insert the working dir at index 0, before the other filenames. - let filenames = - iter::once(working_dir).chain(self.raw_file_table.iter().map(Symbol::as_str)); - llvm_cov::write_filenames_to_buffer(filenames) + table.push( + tcx.sess + .opts + .working_dir + .for_scope(tcx.sess, RemapPathScopeComponents::MACRO) + .to_string_lossy(), + ); + + // Add the regular entries after the base directory. + table.extend(self.raw_file_table.values().map(|file| { + file.name.for_scope(tcx.sess, RemapPathScopeComponents::MACRO).to_string_lossy() + })); + + llvm_cov::write_filenames_to_buffer(table.iter().map(|f| f.as_ref())) } } @@ -208,7 +211,7 @@ rustc_index::newtype_index! { /// An index into a function's list of global file IDs. That underlying list /// of local-to-global mappings will be embedded in the function's record in /// the `__llvm_covfun` linker section. - pub(crate) struct LocalFileId {} + struct LocalFileId {} } /// Holds a mapping from "local" (per-function) file IDs to "global" (per-CGU) @@ -234,13 +237,6 @@ impl VirtualFileMapping { } } -fn span_file_name(tcx: TyCtxt<'_>, span: Span) -> Symbol { - let source_file = tcx.sess.source_map().lookup_source_file(span.lo()); - let name = - source_file.name.for_scope(tcx.sess, RemapPathScopeComponents::MACRO).to_string_lossy(); - Symbol::intern(&name) -} - /// 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. @@ -251,11 +247,13 @@ fn encode_mappings_for_function( global_file_table: &GlobalFileTable, function_coverage: &FunctionCoverage<'_>, ) -> Vec<u8> { - let counter_regions = function_coverage.counter_regions(); - if counter_regions.is_empty() { + let mapping_spans = function_coverage.mapping_spans(); + if mapping_spans.is_empty() { return Vec::new(); } + let fn_cov_info = function_coverage.function_coverage_info; + let expressions = function_coverage.counter_expressions().collect::<Vec<_>>(); let mut virtual_file_mapping = VirtualFileMapping::default(); @@ -265,34 +263,39 @@ fn encode_mappings_for_function( let mut mcdc_decision_regions = vec![]; // Currently a function's mappings must all be in the same file as its body span. - let file_name = span_file_name(tcx, function_coverage.function_coverage_info.body_span); + let source_map = tcx.sess.source_map(); + let source_file = source_map.lookup_source_file(fn_cov_info.body_span.lo()); - // Look up the global file ID for that filename. - let global_file_id = global_file_table.global_file_id_for_file_name(file_name); + // Look up the global file ID for that file. + let global_file_id = global_file_table.global_file_id_for_file(&source_file); // Associate that global file ID with a local file ID for this function. let local_file_id = virtual_file_mapping.local_id_for_global(global_file_id); - debug!(" file id: {local_file_id:?} => {global_file_id:?} = '{file_name:?}'"); - // For each counter/region pair in this function+file, convert it to a + let make_cov_span = |span| { + spans::make_coverage_span(local_file_id, source_map, fn_cov_info, &source_file, span) + }; + + // For each coverage mapping span in this function+file, convert it to a // form suitable for FFI. - for (mapping_kind, region) in counter_regions { - debug!("Adding counter {mapping_kind:?} to map for {region:?}"); - let span = ffi::CoverageSpan::from_source_region(local_file_id, region); + for (mapping_kind, span) in mapping_spans { + debug!("Adding counter {mapping_kind:?} to map for {span:?}"); + let Some(cov_span) = make_cov_span(span) else { continue }; match mapping_kind { MappingKind::Code(term) => { - code_regions.push(ffi::CodeRegion { span, counter: ffi::Counter::from_term(term) }); + code_regions + .push(ffi::CodeRegion { cov_span, counter: ffi::Counter::from_term(term) }); } MappingKind::Branch { true_term, false_term } => { branch_regions.push(ffi::BranchRegion { - span, + cov_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, + cov_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), @@ -300,7 +303,7 @@ fn encode_mappings_for_function( } MappingKind::MCDCDecision(mcdc_decision_params) => { mcdc_decision_regions.push(ffi::MCDCDecisionRegion { - span, + cov_span, mcdc_decision_params: ffi::mcdc::DecisionParameters::from(mcdc_decision_params), }); } diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs new file mode 100644 index 00000000000..4a7721879fd --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/spans.rs @@ -0,0 +1,124 @@ +use rustc_middle::mir::coverage::FunctionCoverageInfo; +use rustc_span::source_map::SourceMap; +use rustc_span::{BytePos, Pos, SourceFile, Span}; +use tracing::debug; + +use crate::coverageinfo::ffi; +use crate::coverageinfo::mapgen::LocalFileId; + +/// Converts the span into its start line and column, and end line and column. +/// +/// Line numbers and column numbers are 1-based. Unlike most column numbers emitted by +/// the compiler, these column numbers are denoted in **bytes**, because that's what +/// LLVM's `llvm-cov` tool expects to see in coverage maps. +/// +/// Returns `None` if the conversion failed for some reason. This shouldn't happen, +/// but it's hard to rule out entirely (especially in the presence of complex macros +/// 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_coverage_span( + file_id: LocalFileId, + source_map: &SourceMap, + fn_cov_info: &FunctionCoverageInfo, + file: &SourceFile, + span: Span, +) -> Option<ffi::CoverageSpan> { + let span = ensure_non_empty_span(source_map, fn_cov_info, span)?; + + let lo = span.lo(); + let hi = span.hi(); + + // Column numbers need to be in bytes, so we can't use the more convenient + // `SourceMap` methods for looking up file coordinates. + let line_and_byte_column = |pos: BytePos| -> Option<(usize, usize)> { + let rpos = file.relative_position(pos); + let line_index = file.lookup_line(rpos)?; + let line_start = file.lines()[line_index]; + // Line numbers and column numbers are 1-based, so add 1 to each. + Some((line_index + 1, (rpos - line_start).to_usize() + 1)) + }; + + let (mut start_line, start_col) = line_and_byte_column(lo)?; + let (mut end_line, end_col) = line_and_byte_column(hi)?; + + // Apply an offset so that code in doctests has correct line numbers. + // FIXME(#79417): Currently we have no way to offset doctest _columns_. + start_line = source_map.doctest_offset_line(&file.name, start_line); + end_line = source_map.doctest_offset_line(&file.name, end_line); + + check_coverage_span(ffi::CoverageSpan { + file_id: file_id.as_u32(), + start_line: start_line as u32, + start_col: start_col as u32, + end_line: end_line as u32, + end_col: end_col as u32, + }) +} + +fn ensure_non_empty_span( + source_map: &SourceMap, + fn_cov_info: &FunctionCoverageInfo, + span: Span, +) -> Option<Span> { + if !span.is_empty() { + return Some(span); + } + + let lo = span.lo(); + let hi = span.hi(); + + // The span is empty, so try to expand it to cover an adjacent '{' or '}', + // but only within the bounds of the body span. + let try_next = hi < fn_cov_info.body_span.hi(); + let try_prev = fn_cov_info.body_span.lo() < lo; + if !(try_next || try_prev) { + return None; + } + + source_map + .span_to_source(span, |src, start, end| try { + // We're only checking for specific ASCII characters, so we don't + // have to worry about multi-byte code points. + if try_next && src.as_bytes()[end] == b'{' { + Some(span.with_hi(hi + BytePos(1))) + } else if try_prev && src.as_bytes()[start - 1] == b'}' { + Some(span.with_lo(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 +/// way that makes them improperly ordered. +fn check_coverage_span(cov_span: ffi::CoverageSpan) -> Option<ffi::CoverageSpan> { + let ffi::CoverageSpan { file_id: _, start_line, start_col, end_line, end_col } = cov_span; + + // Line/column coordinates are supposed to be 1-based. If we ever emit + // coordinates of 0, `llvm-cov` might misinterpret them. + let all_nonzero = [start_line, start_col, end_line, end_col].into_iter().all(|x| x != 0); + // Coverage mappings use the high bit of `end_col` to indicate that a + // region is actually a "gap" region, so make sure it's unset. + let end_col_has_high_bit_unset = (end_col & (1 << 31)) == 0; + // If a region is improperly ordered (end < start), `llvm-cov` will exit + // with a fatal error, which is inconvenient for users and hard to debug. + let is_ordered = (start_line, start_col) <= (end_line, end_col); + + if all_nonzero && end_col_has_high_bit_unset && is_ordered { + Some(cov_span) + } else { + debug!( + ?cov_span, + ?all_nonzero, + ?end_col_has_high_bit_unset, + ?is_ordered, + "Skipping source region that would be misinterpreted or rejected by LLVM" + ); + // If this happens in a debug build, ICE to make it easier to notice. + debug_assert!(false, "Improper source region: {cov_span:?}"); + None + } +} diff --git a/compiler/rustc_codegen_llvm/src/lib.rs b/compiler/rustc_codegen_llvm/src/lib.rs index 3dfb86d422d..9f398107fc6 100644 --- a/compiler/rustc_codegen_llvm/src/lib.rs +++ b/compiler/rustc_codegen_llvm/src/lib.rs @@ -17,6 +17,7 @@ #![feature(iter_intersperse)] #![feature(let_chains)] #![feature(rustdoc_internals)] +#![feature(try_blocks)] #![warn(unreachable_pub)] // tidy-alphabetical-end |