From 2748009aade554a31dd4ea3312cf7a8314f6105d Mon Sep 17 00:00:00 2001 From: Zalathar Date: Sun, 24 Nov 2024 22:41:56 +1100 Subject: [PATCH] coverage: Identify source files by ID, not by interned filename --- .../src/coverageinfo/mapgen.rs | 85 +++++++++---------- 1 file changed, 42 insertions(+), 43 deletions(-) diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs index e8dfed1f06a5f..ed881418cb003 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs @@ -1,14 +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; @@ -17,7 +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; @@ -74,11 +74,11 @@ pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { .map(|(instance, function_coverage)| (instance, function_coverage.into_finished())) .collect::>(); - 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); @@ -143,29 +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, + raw_file_table: FxIndexMap>, } impl GlobalFileTable { - fn new(all_file_names: impl IntoIterator) -> 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::>(); + fn new(all_files: impl IntoIterator>) -> 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::>>(); - // 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. @@ -173,24 +178,27 @@ impl GlobalFileTable { } fn make_filenames_buffer(&self, tcx: TyCtxt<'_>) -> Vec { + 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())) } } @@ -229,13 +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. @@ -262,16 +263,14 @@ 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, fn_cov_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:?}'"); let make_cov_span = |span| { spans::make_coverage_span(local_file_id, source_map, fn_cov_info, &source_file, span)