From 33706fc17f858caf42d36a9f67ef794269b6a83f Mon Sep 17 00:00:00 2001 From: Zalathar Date: Sat, 2 Aug 2025 22:17:14 +1000 Subject: coverage: Include an `Instance` in `CovfunRecord` for debug messages --- compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'compiler/rustc_codegen_llvm/src') diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs index b704cf2b1cd..44b6eb0e689 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, @@ -106,7 +110,7 @@ fn fill_region_tables<'tcx>( // 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()); @@ -184,6 +188,7 @@ pub(crate) fn generate_covfun_record<'tcx>( covfun: &CovfunRecord<'tcx>, ) { let &CovfunRecord { + _instance, mangled_function_name, source_hash, is_used, -- cgit 1.4.1-3-g733a5 From 16843ce427965a39a5f226ce3057ba3c2f5ed23c Mon Sep 17 00:00:00 2001 From: Zalathar Date: Fri, 9 May 2025 21:27:27 +1000 Subject: coverage: Hoist `counter_for_bcb` out of its loop Having this helper function in the loop was confusing, because it doesn't rely on anything that changes between loop iterations. --- .../src/coverageinfo/mapgen/covfun.rs | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'compiler/rustc_codegen_llvm/src') diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs index 44b6eb0e689..69dfe1e98db 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs @@ -106,6 +106,16 @@ 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(); @@ -137,16 +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); -- cgit 1.4.1-3-g733a5 From f496e83fe9a12cbaec6a61da83ba32159a87afde Mon Sep 17 00:00:00 2001 From: Zalathar Date: Sat, 2 Aug 2025 18:41:04 +1000 Subject: coverage: Simplify access to debug/testing `-Zcoverage-options` flags --- .../rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs | 2 +- compiler/rustc_session/src/config.rs | 1 + compiler/rustc_session/src/session.rs | 12 +++++++----- 3 files changed, 9 insertions(+), 6 deletions(-) (limited to 'compiler/rustc_codegen_llvm/src') diff --git a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs index 69dfe1e98db..fd1e7f7f160 100644 --- a/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs +++ b/compiler/rustc_codegen_llvm/src/coverageinfo/mapgen/covfun.rs @@ -131,7 +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) } }; diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs index e82f4527c6c..cfeadf3c759 100644 --- a/compiler/rustc_session/src/config.rs +++ b/compiler/rustc_session/src/config.rs @@ -182,6 +182,7 @@ pub enum InstrumentCoverage { pub struct CoverageOptions { pub level: CoverageLevel, + /// **(internal test-only flag)** /// `-Zcoverage-options=discard-all-spans-in-codegen`: During codegen, /// discard all coverage spans as though they were invalid. Needed by /// regression tests for #133606, because we don't have an easy way to diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs index c311a726aa7..b94636fea94 100644 --- a/compiler/rustc_session/src/session.rs +++ b/compiler/rustc_session/src/session.rs @@ -39,8 +39,8 @@ use rustc_target::spec::{ use crate::code_stats::CodeStats; pub use crate::code_stats::{DataTypeKind, FieldInfo, FieldKind, SizeKind, VariantInfo}; use crate::config::{ - self, CoverageLevel, CrateType, DebugInfo, ErrorOutputType, FunctionReturn, Input, - InstrumentCoverage, OptLevel, OutFileName, OutputType, RemapPathScopeComponents, + self, CoverageLevel, CoverageOptions, CrateType, DebugInfo, ErrorOutputType, FunctionReturn, + Input, InstrumentCoverage, OptLevel, OutFileName, OutputType, RemapPathScopeComponents, SwitchWithOptPath, }; use crate::filesearch::FileSearch; @@ -359,9 +359,11 @@ impl Session { && self.opts.unstable_opts.coverage_options.level >= CoverageLevel::Mcdc } - /// True if `-Zcoverage-options=discard-all-spans-in-codegen` was passed. - pub fn coverage_discard_all_spans_in_codegen(&self) -> bool { - self.opts.unstable_opts.coverage_options.discard_all_spans_in_codegen + /// Provides direct access to the `CoverageOptions` struct, so that + /// individual flags for debugging/testing coverage instrumetation don't + /// need separate accessors. + pub fn coverage_options(&self) -> &CoverageOptions { + &self.opts.unstable_opts.coverage_options } pub fn is_sanitizer_cfi_enabled(&self) -> bool { -- cgit 1.4.1-3-g733a5 From b37c214ec2bbb7609eb4b963bb2b0da160fef57f Mon Sep 17 00:00:00 2001 From: Zalathar Date: Sun, 3 Aug 2025 14:35:17 +1000 Subject: coverage: Represent `CovmapVersion` as an enum Using an enum here was historically not worth the extra hassle, but now we can lean on `#[derive(TryFromU32)]` to hide most of the boilerplate. --- .../rustc_codegen_llvm/src/coverageinfo/mapgen.rs | 47 +++++++++++++++------- 1 file changed, 32 insertions(+), 15 deletions(-) (limited to 'compiler/rustc_codegen_llvm/src') 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, ); -- cgit 1.4.1-3-g733a5 From 868bdde25b030e0b71a29a5dbc04a891036e702e Mon Sep 17 00:00:00 2001 From: Sebastian Poeplau Date: Fri, 1 Aug 2025 12:39:50 +0200 Subject: Preserve the .debug_gdb_scripts section Make sure that compiler and linker don't optimize the section's contents away by adding the global holding the data to "llvm.used". The volatile load in the main shim is retained because "llvm.used", which translates to SHF_GNU_RETAIN on ELF targets, requires a reasonably recent linker; emitting the volatile load ensures compatibility with older linkers, at least when libstd is used. Pretty printers in dylib dependencies are now emitted by the main crate instead of the dylib; apart from matching how rlibs are handled, this approach has the advantage that `omit_gdb_pretty_printer_section` keeps working with dylib dependencies. --- compiler/rustc_codegen_gcc/src/debuginfo.rs | 3 +- compiler/rustc_codegen_llvm/src/base.rs | 12 ++++---- compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs | 30 +++++++++--------- compiler/rustc_codegen_llvm/src/debuginfo/mod.rs | 36 +++++++++++++--------- compiler/rustc_codegen_ssa/src/base.rs | 10 +----- compiler/rustc_codegen_ssa/src/traits/debuginfo.rs | 2 +- tests/codegen-llvm/gdb_debug_script_load.rs | 4 ++- tests/run-make/symbols-all-mangled/rmake.rs | 35 ++++++++++++--------- 8 files changed, 72 insertions(+), 60 deletions(-) (limited to 'compiler/rustc_codegen_llvm/src') diff --git a/compiler/rustc_codegen_gcc/src/debuginfo.rs b/compiler/rustc_codegen_gcc/src/debuginfo.rs index 4c8585192a1..4c0b6439523 100644 --- a/compiler/rustc_codegen_gcc/src/debuginfo.rs +++ b/compiler/rustc_codegen_gcc/src/debuginfo.rs @@ -254,7 +254,8 @@ impl<'gcc, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> { // TODO(antoyo): implement. } - fn debuginfo_finalize(&self) { + fn debuginfo_finalize(&mut self) { + // TODO: emit section `.debug_gdb_scripts`. self.context.set_debug_info(true) } diff --git a/compiler/rustc_codegen_llvm/src/base.rs b/compiler/rustc_codegen_llvm/src/base.rs index 5dda836988c..d7da03bf490 100644 --- a/compiler/rustc_codegen_llvm/src/base.rs +++ b/compiler/rustc_codegen_llvm/src/base.rs @@ -109,11 +109,16 @@ pub(crate) fn compile_codegen_unit( } // Finalize code coverage by injecting the coverage map. Note, the coverage map will - // also be added to the `llvm.compiler.used` variable, created next. + // also be added to the `llvm.compiler.used` variable, created below. if cx.sess().instrument_coverage() { cx.coverageinfo_finalize(); } + // Finalize debuginfo. This adds to `llvm.used`, created below. + if cx.sess().opts.debuginfo != DebugInfo::None { + cx.debuginfo_finalize(); + } + // Create the llvm.used and llvm.compiler.used variables. if !cx.used_statics.is_empty() { cx.create_used_variable_impl(c"llvm.used", &cx.used_statics); @@ -130,11 +135,6 @@ pub(crate) fn compile_codegen_unit( llvm::LLVMDeleteGlobal(old_g); } } - - // Finalize debuginfo - if cx.sess().opts.debuginfo != DebugInfo::None { - cx.debuginfo_finalize(); - } } ModuleCodegen::new_regular(cgu_name.to_string(), llvm_module) diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs index 6eb7042da61..b3e978be570 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs @@ -1,5 +1,7 @@ // .debug_gdb_scripts binary section. +use std::ffi::CString; + use rustc_codegen_ssa::base::collect_debugger_visualizers_transitive; use rustc_codegen_ssa::traits::*; use rustc_hir::def_id::LOCAL_CRATE; @@ -31,7 +33,12 @@ pub(crate) fn insert_reference_to_gdb_debug_scripts_section_global(bx: &mut Buil pub(crate) fn get_or_insert_gdb_debug_scripts_section_global<'ll>( cx: &CodegenCx<'ll, '_>, ) -> &'ll Value { - let c_section_var_name = c"__rustc_debug_gdb_scripts_section__"; + let c_section_var_name = CString::new(format!( + "__rustc_debug_gdb_scripts_section_{}_{:08x}", + cx.tcx.crate_name(LOCAL_CRATE), + cx.tcx.stable_crate_id(LOCAL_CRATE), + )) + .unwrap(); let section_var_name = c_section_var_name.to_str().unwrap(); let section_var = unsafe { llvm::LLVMGetNamedGlobal(cx.llmod, c_section_var_name.as_ptr()) }; @@ -84,17 +91,10 @@ pub(crate) fn get_or_insert_gdb_debug_scripts_section_global<'ll>( } pub(crate) fn needs_gdb_debug_scripts_section(cx: &CodegenCx<'_, '_>) -> bool { - // To ensure the section `__rustc_debug_gdb_scripts_section__` will not create - // ODR violations at link time, this section will not be emitted for rlibs since - // each rlib could produce a different set of visualizers that would be embedded - // in the `.debug_gdb_scripts` section. For that reason, we make sure that the - // section is only emitted for leaf crates. + // We collect pretty printers transitively for all crates, so we make sure + // that the section is only emitted for leaf crates. let embed_visualizers = cx.tcx.crate_types().iter().any(|&crate_type| match crate_type { - CrateType::Executable - | CrateType::Dylib - | CrateType::Cdylib - | CrateType::Staticlib - | CrateType::Sdylib => { + CrateType::Executable | CrateType::Cdylib | CrateType::Staticlib | CrateType::Sdylib => { // These are crate types for which we will embed pretty printers since they // are treated as leaf crates. true @@ -105,9 +105,11 @@ pub(crate) fn needs_gdb_debug_scripts_section(cx: &CodegenCx<'_, '_>) -> bool { // want to slow down the common case. false } - CrateType::Rlib => { - // As per the above description, embedding pretty printers for rlibs could - // lead to ODR violations so we skip this crate type as well. + CrateType::Rlib | CrateType::Dylib => { + // Don't embed pretty printers for these crate types; the compiler + // can see the `#[debug_visualizer]` attributes when using the + // library, and emitting `.debug_gdb_scripts` regardless would + // break `#![omit_gdb_pretty_printer_section]`. false } }); diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs index 6cbf2dbf7d3..c911435967c 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs @@ -30,7 +30,7 @@ use tracing::debug; use self::metadata::{UNKNOWN_COLUMN_NUMBER, UNKNOWN_LINE_NUMBER, file_metadata, type_di_node}; use self::namespace::mangled_name_of_instance; -use self::utils::{DIB, create_DIArray, is_node_local_to_unit}; +use self::utils::{DIB, create_DIArray, debug_context, is_node_local_to_unit}; use crate::builder::Builder; use crate::common::{AsCCharPtr, CodegenCx}; use crate::llvm; @@ -131,20 +131,28 @@ impl<'ll, 'tcx> CodegenUnitDebugContext<'ll, 'tcx> { } /// Creates any deferred debug metadata nodes -pub(crate) fn finalize(cx: &CodegenCx<'_, '_>) { - if let Some(dbg_cx) = &cx.dbg_cx { - debug!("finalize"); - - if gdb::needs_gdb_debug_scripts_section(cx) { - // Add a .debug_gdb_scripts section to this compile-unit. This will - // cause GDB to try and load the gdb_load_rust_pretty_printers.py file, - // which activates the Rust pretty printers for binary this section is - // contained in. - gdb::get_or_insert_gdb_debug_scripts_section_global(cx); - } +pub(crate) fn finalize(cx: &mut CodegenCx<'_, '_>) { + if cx.dbg_cx.is_none() { + return; + } + + debug!("finalize"); - dbg_cx.finalize(cx.sess()); + if gdb::needs_gdb_debug_scripts_section(cx) { + // Add a .debug_gdb_scripts section to this compile-unit. This will + // cause GDB to try and load the gdb_load_rust_pretty_printers.py file, + // which activates the Rust pretty printers for binary this section is + // contained in. + let section_var = gdb::get_or_insert_gdb_debug_scripts_section_global(cx); + + // Make sure that the linker doesn't optimize the global away. Adding + // it to `llvm.used` has the advantage that it works even in no_std + // binaries, where we don't have a main shim and thus don't emit a + // volatile load to preserve the global. + cx.add_used_global(section_var); } + + debug_context(cx).finalize(cx.sess()); } impl<'ll> Builder<'_, 'll, '_> { @@ -614,7 +622,7 @@ impl<'ll, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'ll, 'tcx> { metadata::extend_scope_to_file(self, scope_metadata, file) } - fn debuginfo_finalize(&self) { + fn debuginfo_finalize(&mut self) { finalize(self) } diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs index b4556ced0b3..eb21468650c 100644 --- a/compiler/rustc_codegen_ssa/src/base.rs +++ b/compiler/rustc_codegen_ssa/src/base.rs @@ -609,15 +609,7 @@ pub fn collect_debugger_visualizers_transitive( ) -> BTreeSet { tcx.debugger_visualizers(LOCAL_CRATE) .iter() - .chain( - tcx.crates(()) - .iter() - .filter(|&cnum| { - let used_crate_source = tcx.used_crate_source(*cnum); - used_crate_source.rlib.is_some() || used_crate_source.rmeta.is_some() - }) - .flat_map(|&cnum| tcx.debugger_visualizers(cnum)), - ) + .chain(tcx.crates(()).iter().flat_map(|&cnum| tcx.debugger_visualizers(cnum))) .filter(|visualizer| visualizer.visualizer_type == visualizer_type) .cloned() .collect::>() diff --git a/compiler/rustc_codegen_ssa/src/traits/debuginfo.rs b/compiler/rustc_codegen_ssa/src/traits/debuginfo.rs index b9d4950e0ad..30a3bd5abe4 100644 --- a/compiler/rustc_codegen_ssa/src/traits/debuginfo.rs +++ b/compiler/rustc_codegen_ssa/src/traits/debuginfo.rs @@ -50,7 +50,7 @@ pub trait DebugInfoCodegenMethods<'tcx>: BackendTypes { scope_metadata: Self::DIScope, file: &SourceFile, ) -> Self::DIScope; - fn debuginfo_finalize(&self); + fn debuginfo_finalize(&mut self); // FIXME(eddyb) find a common convention for all of the debuginfo-related // names (choose between `dbg`, `debug`, `debuginfo`, `debug_info` etc.). diff --git a/tests/codegen-llvm/gdb_debug_script_load.rs b/tests/codegen-llvm/gdb_debug_script_load.rs index 3e92eba10b1..90f2be41cf2 100644 --- a/tests/codegen-llvm/gdb_debug_script_load.rs +++ b/tests/codegen-llvm/gdb_debug_script_load.rs @@ -9,6 +9,8 @@ #![feature(lang_items)] #![no_std] +// CHECK: @llvm.used = {{.+}} @__rustc_debug_gdb_scripts_section + #[panic_handler] fn panic_handler(_: &core::panic::PanicInfo) -> ! { loop {} @@ -22,7 +24,7 @@ extern "C" fn rust_eh_personality() { // Needs rustc to generate `main` as that's where the magic load is inserted. // IOW, we cannot write this test with `#![no_main]`. // CHECK-LABEL: @main -// CHECK: load volatile i8, {{.+}} @__rustc_debug_gdb_scripts_section__ +// CHECK: load volatile i8, {{.+}} @__rustc_debug_gdb_scripts_section #[lang = "start"] fn lang_start( diff --git a/tests/run-make/symbols-all-mangled/rmake.rs b/tests/run-make/symbols-all-mangled/rmake.rs index 2cf57975800..e30bef98580 100644 --- a/tests/run-make/symbols-all-mangled/rmake.rs +++ b/tests/run-make/symbols-all-mangled/rmake.rs @@ -35,13 +35,7 @@ fn symbols_check_archive(path: &str) { continue; // All compiler-builtins symbols must remain unmangled } - if name.contains("rust_eh_personality") { - continue; // Unfortunately LLVM doesn't allow us to mangle this symbol - } - - if name.contains(".llvm.") { - // Starting in LLVM 21 we get various implementation-detail functions which - // contain .llvm. that are not a problem. + if symbol_ok_everywhere(name) { continue; } @@ -71,13 +65,7 @@ fn symbols_check(path: &str) { continue; } - if name.contains("rust_eh_personality") { - continue; // Unfortunately LLVM doesn't allow us to mangle this symbol - } - - if name.contains(".llvm.") { - // Starting in LLVM 21 we get various implementation-detail functions which - // contain .llvm. that are not a problem. + if symbol_ok_everywhere(name) { continue; } @@ -88,3 +76,22 @@ fn symbols_check(path: &str) { fn strip_underscore_if_apple(symbol: &str) -> &str { if cfg!(target_vendor = "apple") { symbol.strip_prefix("_").unwrap() } else { symbol } } + +fn symbol_ok_everywhere(name: &str) -> bool { + if name.contains("rust_eh_personality") { + return true; // Unfortunately LLVM doesn't allow us to mangle this symbol + } + + if name.contains(".llvm.") { + // Starting in LLVM 21 we get various implementation-detail functions which + // contain .llvm. that are not a problem. + return true; + } + + if name.starts_with("__rustc_debug_gdb_scripts_section") { + // These symbols are fine; they're made unique by the crate ID. + return true; + } + + return false; +} -- cgit 1.4.1-3-g733a5 From b4d923cea0509933b1fb859930cb20784251f9be Mon Sep 17 00:00:00 2001 From: Sebastian Poeplau Date: Fri, 1 Aug 2025 13:22:06 +0200 Subject: Embed GDB pretty printers in rlibs and dylibs Instead of collecting pretty printers transitively when building executables/staticlibs/cdylibs, let the debugger find each crate's pretty printers via its .debug_gdb_scripts section. This covers the case where libraries defining custom pretty printers are loaded dynamically. --- compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs | 43 ++++++---------------- compiler/rustc_codegen_ssa/src/base.rs | 10 ++++- .../compiletest/src/directives/directive_names.rs | 1 + tests/debuginfo/embedded-visualizer.rs | 2 + 4 files changed, 23 insertions(+), 33 deletions(-) (limited to 'compiler/rustc_codegen_llvm/src') diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs index b3e978be570..fccd32dec95 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/gdb.rs @@ -1,13 +1,13 @@ // .debug_gdb_scripts binary section. +use std::collections::BTreeSet; use std::ffi::CString; -use rustc_codegen_ssa::base::collect_debugger_visualizers_transitive; use rustc_codegen_ssa::traits::*; use rustc_hir::def_id::LOCAL_CRATE; use rustc_middle::bug; use rustc_middle::middle::debugger_visualizer::DebuggerVisualizerType; -use rustc_session::config::{CrateType, DebugInfo}; +use rustc_session::config::DebugInfo; use crate::builder::Builder; use crate::common::CodegenCx; @@ -51,10 +51,14 @@ pub(crate) fn get_or_insert_gdb_debug_scripts_section_global<'ll>( // Next, add the pretty printers that were specified via the `#[debugger_visualizer]` // attribute. - let visualizers = collect_debugger_visualizers_transitive( - cx.tcx, - DebuggerVisualizerType::GdbPrettyPrinter, - ); + let visualizers = cx + .tcx + .debugger_visualizers(LOCAL_CRATE) + .iter() + .filter(|visualizer| { + visualizer.visualizer_type == DebuggerVisualizerType::GdbPrettyPrinter + }) + .collect::>(); let crate_name = cx.tcx.crate_name(LOCAL_CRATE); for (index, visualizer) in visualizers.iter().enumerate() { // The initial byte `4` instructs GDB that the following pretty printer @@ -91,30 +95,5 @@ pub(crate) fn get_or_insert_gdb_debug_scripts_section_global<'ll>( } pub(crate) fn needs_gdb_debug_scripts_section(cx: &CodegenCx<'_, '_>) -> bool { - // We collect pretty printers transitively for all crates, so we make sure - // that the section is only emitted for leaf crates. - let embed_visualizers = cx.tcx.crate_types().iter().any(|&crate_type| match crate_type { - CrateType::Executable | CrateType::Cdylib | CrateType::Staticlib | CrateType::Sdylib => { - // These are crate types for which we will embed pretty printers since they - // are treated as leaf crates. - true - } - CrateType::ProcMacro => { - // We could embed pretty printers for proc macro crates too but it does not - // seem like a good default, since this is a rare use case and we don't - // want to slow down the common case. - false - } - CrateType::Rlib | CrateType::Dylib => { - // Don't embed pretty printers for these crate types; the compiler - // can see the `#[debug_visualizer]` attributes when using the - // library, and emitting `.debug_gdb_scripts` regardless would - // break `#![omit_gdb_pretty_printer_section]`. - false - } - }); - - cx.sess().opts.debuginfo != DebugInfo::None - && cx.sess().target.emit_debug_gdb_scripts - && embed_visualizers + cx.sess().opts.debuginfo != DebugInfo::None && cx.sess().target.emit_debug_gdb_scripts } diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs index eb21468650c..b4556ced0b3 100644 --- a/compiler/rustc_codegen_ssa/src/base.rs +++ b/compiler/rustc_codegen_ssa/src/base.rs @@ -609,7 +609,15 @@ pub fn collect_debugger_visualizers_transitive( ) -> BTreeSet { tcx.debugger_visualizers(LOCAL_CRATE) .iter() - .chain(tcx.crates(()).iter().flat_map(|&cnum| tcx.debugger_visualizers(cnum))) + .chain( + tcx.crates(()) + .iter() + .filter(|&cnum| { + let used_crate_source = tcx.used_crate_source(*cnum); + used_crate_source.rlib.is_some() || used_crate_source.rmeta.is_some() + }) + .flat_map(|&cnum| tcx.debugger_visualizers(cnum)), + ) .filter(|visualizer| visualizer.visualizer_type == visualizer_type) .cloned() .collect::>() diff --git a/src/tools/compiletest/src/directives/directive_names.rs b/src/tools/compiletest/src/directives/directive_names.rs index f7955429d83..099058bf051 100644 --- a/src/tools/compiletest/src/directives/directive_names.rs +++ b/src/tools/compiletest/src/directives/directive_names.rs @@ -68,6 +68,7 @@ pub(crate) const KNOWN_DIRECTIVE_NAMES: &[&str] = &[ "ignore-gnu", "ignore-haiku", "ignore-horizon", + "ignore-i586-unknown-linux-gnu", "ignore-i686-pc-windows-gnu", "ignore-i686-pc-windows-msvc", "ignore-illumos", diff --git a/tests/debuginfo/embedded-visualizer.rs b/tests/debuginfo/embedded-visualizer.rs index cbd8691394d..12d87be7c66 100644 --- a/tests/debuginfo/embedded-visualizer.rs +++ b/tests/debuginfo/embedded-visualizer.rs @@ -1,6 +1,8 @@ //@ compile-flags:-g //@ ignore-lldb //@ ignore-windows-gnu: #128981 +//@ ignore-musl: linker too old in CI +//@ ignore-i586-unknown-linux-gnu: linker too old in CI // === CDB TESTS ================================================================================== -- cgit 1.4.1-3-g733a5