From 0504a333837e10f19454901fd060c0f99bf8f5b7 Mon Sep 17 00:00:00 2001 From: Julia Tatz Date: Tue, 6 Apr 2021 16:00:35 -0400 Subject: [PATCH] Preserve, clarify, and extend debug information `-Cdebuginfo=1` was never line tables only and can't be due to backwards compatibility issues. This was clarified and an option for line tables only was added. Additionally an option for line info directives only was added, which is well needed for some targets. The debug info options should now behave the same as clang's debug info options. --- .../src/debuginfo/metadata.rs | 19 +----------- .../rustc_codegen_llvm/src/debuginfo/mod.rs | 2 +- compiler/rustc_codegen_llvm/src/llvm/ffi.rs | 6 ++-- compiler/rustc_codegen_ssa/src/back/linker.rs | 5 +++- compiler/rustc_interface/src/tests.rs | 3 +- .../rustc_llvm/llvm-wrapper/RustWrapper.cpp | 3 ++ compiler/rustc_session/src/config.rs | 29 ++++--------------- compiler/rustc_session/src/options.rs | 19 ++++++++++-- src/doc/rustc/src/codegen-options/index.md | 8 +++-- tests/codegen/debug-limited.rs | 28 ++++++++++++++++++ tests/codegen/debug-line-directives-only.rs | 28 ++++++++++++++++++ tests/codegen/debug-line-tables-only.rs | 28 ++++++++++++++++++ tests/rustdoc-ui/c-help.stdout | 2 +- 13 files changed, 126 insertions(+), 54 deletions(-) create mode 100644 tests/codegen/debug-limited.rs create mode 100644 tests/codegen/debug-line-directives-only.rs create mode 100644 tests/codegen/debug-line-tables-only.rs diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs index e2a592d851a..4bf6762d1f6 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs @@ -830,24 +830,7 @@ pub fn build_compile_unit_di_node<'ll, 'tcx>( } .unwrap_or_default(); let split_name = split_name.to_str().unwrap(); - - // FIXME(#60020): - // - // This should actually be - // - // let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo); - // - // That is, we should set LLVM's emission kind to `LineTablesOnly` if - // we are compiling with "limited" debuginfo. However, some of the - // existing tools relied on slightly more debuginfo being generated than - // would be the case with `LineTablesOnly`, and we did not want to break - // these tools in a "drive-by fix", without a good idea or plan about - // what limited debuginfo should exactly look like. So for now we keep - // the emission kind as `FullDebug`. - // - // See https://github.com/rust-lang/rust/issues/60020 for details. - let kind = DebugEmissionKind::FullDebug; - assert!(tcx.sess.opts.debuginfo != DebugInfo::None); + let kind = DebugEmissionKind::from_generic(tcx.sess.opts.debuginfo); unsafe { let compile_unit_file = llvm::LLVMRustDIBuilderCreateFile( diff --git a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs index 5392534cfcb..41a75c9d775 100644 --- a/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs +++ b/compiler/rustc_codegen_llvm/src/debuginfo/mod.rs @@ -402,7 +402,7 @@ impl<'ll, 'tcx> DebugInfoMethods<'tcx> for CodegenCx<'ll, 'tcx> { cx: &CodegenCx<'ll, 'tcx>, fn_abi: &FnAbi<'tcx, Ty<'tcx>>, ) -> &'ll DIArray { - if cx.sess().opts.debuginfo == DebugInfo::Limited { + if cx.sess().opts.debuginfo != DebugInfo::Full { return create_DIArray(DIB(cx), &[]); } diff --git a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs index 0d63e634ad8..aff352abab4 100644 --- a/compiler/rustc_codegen_llvm/src/llvm/ffi.rs +++ b/compiler/rustc_codegen_llvm/src/llvm/ffi.rs @@ -946,6 +946,7 @@ pub mod debuginfo { NoDebug, FullDebug, LineTablesOnly, + DebugDirectivesOnly, } impl DebugEmissionKind { @@ -953,8 +954,9 @@ pub mod debuginfo { use rustc_session::config::DebugInfo; match kind { DebugInfo::None => DebugEmissionKind::NoDebug, - DebugInfo::Limited => DebugEmissionKind::LineTablesOnly, - DebugInfo::Full => DebugEmissionKind::FullDebug, + DebugInfo::LineDirectivesOnly => DebugEmissionKind::DebugDirectivesOnly, + DebugInfo::LineTablesOnly => DebugEmissionKind::LineTablesOnly, + DebugInfo::Limited | DebugInfo::Full => DebugEmissionKind::FullDebug, } } } diff --git a/compiler/rustc_codegen_ssa/src/back/linker.rs b/compiler/rustc_codegen_ssa/src/back/linker.rs index 69bb00f804d..65dfc325a11 100644 --- a/compiler/rustc_codegen_ssa/src/back/linker.rs +++ b/compiler/rustc_codegen_ssa/src/back/linker.rs @@ -1121,9 +1121,12 @@ impl<'a> Linker for EmLinker<'a> { fn debuginfo(&mut self, _strip: Strip, _: &[PathBuf]) { // Preserve names or generate source maps depending on debug info + // For more information see https://emscripten.org/docs/tools_reference/emcc.html#emcc-g self.cmd.arg(match self.sess.opts.debuginfo { DebugInfo::None => "-g0", - DebugInfo::Limited => "--profiling-funcs", + DebugInfo::Limited | DebugInfo::LineTablesOnly | DebugInfo::LineDirectivesOnly => { + "--profiling-funcs" + } DebugInfo::Full => "-g", }); } diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs index eb5990507fb..10dfd32d418 100644 --- a/compiler/rustc_interface/src/tests.rs +++ b/compiler/rustc_interface/src/tests.rs @@ -5,6 +5,7 @@ use rustc_data_structures::fx::FxHashSet; use rustc_data_structures::profiling::TimePassesFormat; use rustc_errors::{emitter::HumanReadableErrorType, registry, ColorConfig}; use rustc_session::config::rustc_optgroups; +use rustc_session::config::DebugInfo; use rustc_session::config::Input; use rustc_session::config::InstrumentXRay; use rustc_session::config::TraitSolver; @@ -574,7 +575,7 @@ fn test_codegen_options_tracking_hash() { tracked!(code_model, Some(CodeModel::Large)); tracked!(control_flow_guard, CFGuard::Checks); tracked!(debug_assertions, Some(true)); - tracked!(debuginfo, 0xdeadbeef); + tracked!(debuginfo, DebugInfo::Limited); tracked!(embed_bitcode, false); tracked!(force_frame_pointers, Some(false)); tracked!(force_unwind_tables, Some(true)); diff --git a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp index e3493caaaf7..6a2fd5aa6e6 100644 --- a/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp +++ b/compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp @@ -682,6 +682,7 @@ enum class LLVMRustDebugEmissionKind { NoDebug, FullDebug, LineTablesOnly, + DebugDirectivesOnly, }; static DICompileUnit::DebugEmissionKind fromRust(LLVMRustDebugEmissionKind Kind) { @@ -692,6 +693,8 @@ static DICompileUnit::DebugEmissionKind fromRust(LLVMRustDebugEmissionKind Kind) return DICompileUnit::DebugEmissionKind::FullDebug; case LLVMRustDebugEmissionKind::LineTablesOnly: return DICompileUnit::DebugEmissionKind::LineTablesOnly; + case LLVMRustDebugEmissionKind::DebugDirectivesOnly: + return DICompileUnit::DebugEmissionKind::DebugDirectivesOnly; default: report_fatal_error("bad DebugEmissionKind."); } diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs index 485c3f55462..1d8fedb8bd7 100644 --- a/compiler/rustc_session/src/config.rs +++ b/compiler/rustc_session/src/config.rs @@ -260,6 +260,8 @@ pub enum SymbolManglingVersion { #[derive(Clone, Copy, Debug, PartialEq, Hash)] pub enum DebugInfo { None, + LineDirectivesOnly, + LineTablesOnly, Limited, Full, } @@ -1979,11 +1981,7 @@ fn parse_opt_level( } } -fn select_debuginfo( - matches: &getopts::Matches, - cg: &CodegenOptions, - error_format: ErrorOutputType, -) -> DebugInfo { +fn select_debuginfo(matches: &getopts::Matches, cg: &CodegenOptions) -> DebugInfo { let max_g = matches.opt_positions("g").into_iter().max(); let max_c = matches .opt_strs_pos("C") @@ -1993,24 +1991,7 @@ fn select_debuginfo( if let Some("debuginfo") = s.split('=').next() { Some(i) } else { None } }) .max(); - if max_g > max_c { - DebugInfo::Full - } else { - match cg.debuginfo { - 0 => DebugInfo::None, - 1 => DebugInfo::Limited, - 2 => DebugInfo::Full, - arg => { - early_error( - error_format, - &format!( - "debug info level needs to be between \ - 0-2 (instead was `{arg}`)" - ), - ); - } - } - } + if max_g > max_c { DebugInfo::Full } else { cg.debuginfo } } pub(crate) fn parse_assert_incr_state( @@ -2498,7 +2479,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options { // to use them interchangeably. See the note above (regarding `-O` and `-C opt-level`) // for more details. let debug_assertions = cg.debug_assertions.unwrap_or(opt_level == OptLevel::No); - let debuginfo = select_debuginfo(matches, &cg, error_format); + let debuginfo = select_debuginfo(matches, &cg); let mut search_paths = vec![]; for s in &matches.opt_strs("L") { diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs index c75af48e80a..953d6561669 100644 --- a/compiler/rustc_session/src/options.rs +++ b/compiler/rustc_session/src/options.rs @@ -377,6 +377,7 @@ mod desc { pub const parse_cfguard: &str = "either a boolean (`yes`, `no`, `on`, `off`, etc), `checks`, or `nochecks`"; pub const parse_cfprotection: &str = "`none`|`no`|`n` (default), `branch`, `return`, or `full`|`yes`|`y` (equivalent to `branch` and `return`)"; + pub const parse_debuginfo: &str = "either an integer (0, 1, 2), `none`, `line-directives-only`, `line-tables-only`, `limited`, or `full`"; pub const parse_strip: &str = "either `none`, `debuginfo`, or `symbols`"; pub const parse_linker_flavor: &str = ::rustc_target::spec::LinkerFlavorCli::one_of(); pub const parse_optimization_fuel: &str = "crate=integer"; @@ -767,6 +768,18 @@ mod parse { true } + pub(crate) fn parse_debuginfo(slot: &mut DebugInfo, v: Option<&str>) -> bool { + match v { + Some("0") | Some("none") => *slot = DebugInfo::None, + Some("line-directives-only") => *slot = DebugInfo::LineDirectivesOnly, + Some("line-tables-only") => *slot = DebugInfo::LineTablesOnly, + Some("1") | Some("limited") => *slot = DebugInfo::Limited, + Some("2") | Some("full") => *slot = DebugInfo::Full, + _ => return false, + } + true + } + pub(crate) fn parse_linker_flavor(slot: &mut Option, v: Option<&str>) -> bool { match v.and_then(LinkerFlavorCli::from_str) { Some(lf) => *slot = Some(lf), @@ -1217,9 +1230,9 @@ options! { "use Windows Control Flow Guard (default: no)"), debug_assertions: Option = (None, parse_opt_bool, [TRACKED], "explicitly enable the `cfg(debug_assertions)` directive"), - debuginfo: usize = (0, parse_number, [TRACKED], - "debug info emission level (0 = no debug info, 1 = line tables only, \ - 2 = full debug info with variable and type information; default: 0)"), + debuginfo: DebugInfo = (DebugInfo::None, parse_debuginfo, [TRACKED], + "debug info emission level (0-2, none, line-directives-only, \ + line-tables-only, limited, or full; default: 0)"), default_linker_libraries: bool = (false, parse_bool, [UNTRACKED], "allow the linker to link its default libraries (default: no)"), embed_bitcode: bool = (true, parse_bool, [TRACKED], diff --git a/src/doc/rustc/src/codegen-options/index.md b/src/doc/rustc/src/codegen-options/index.md index c7f120dafea..8b4f1cd2d41 100644 --- a/src/doc/rustc/src/codegen-options/index.md +++ b/src/doc/rustc/src/codegen-options/index.md @@ -71,9 +71,11 @@ If not specified, debug assertions are automatically enabled only if the This flag controls the generation of debug information. It takes one of the following values: -* `0`: no debug info at all (the default). -* `1`: line tables only. -* `2`: full debug info. +* `0` or `none`: no debug info at all (the default). +* `line-directives-only`: line info directives only. +* `line-tables-only`: line tables only. +* `1` or `limited`: debug info without type information. +* `2` or `full`: full debug info. Note: The [`-g` flag][option-g-debug] is an alias for `-C debuginfo=2`. diff --git a/tests/codegen/debug-limited.rs b/tests/codegen/debug-limited.rs new file mode 100644 index 00000000000..fafee0ef583 --- /dev/null +++ b/tests/codegen/debug-limited.rs @@ -0,0 +1,28 @@ +// Verify that the limited debuginfo option emits llvm's FullDebugInfo, but no type info. +// +// ignore-windows +// compile-flags: -C debuginfo=limited + +#[repr(C)] +struct StructType { + a: i64, + b: i32 +} + +extern "C" { + fn creator() -> *mut StructType; + fn save(p: *const StructType); +} + +fn main() { + unsafe { + let value: &mut StructType = &mut* creator(); + value.a = 7; + save(value as *const StructType) + } +} + +// CHECK: !DICompileUnit +// CHECK: emissionKind: FullDebug +// CHECK: !DILocation +// CHECK-NOT: !DIBasicType diff --git a/tests/codegen/debug-line-directives-only.rs b/tests/codegen/debug-line-directives-only.rs new file mode 100644 index 00000000000..0dd22931b30 --- /dev/null +++ b/tests/codegen/debug-line-directives-only.rs @@ -0,0 +1,28 @@ +// Verify that the only debuginfo generated are the line directives. +// +// ignore-windows +// compile-flags: -C debuginfo=line-directives-only + +#[repr(C)] +struct StructType { + a: i64, + b: i32 +} + +extern "C" { + fn creator() -> *mut StructType; + fn save(p: *const StructType); +} + +fn main() { + unsafe { + let value: &mut StructType = &mut* creator(); + value.a = 7; + save(value as *const StructType) + } +} + +// CHECK: !DICompileUnit +// CHECK: emissionKind: DebugDirectivesOnly +// CHECK: !DILocation +// CHECK-NOT: !DIBasicType diff --git a/tests/codegen/debug-line-tables-only.rs b/tests/codegen/debug-line-tables-only.rs new file mode 100644 index 00000000000..3d109d4ae51 --- /dev/null +++ b/tests/codegen/debug-line-tables-only.rs @@ -0,0 +1,28 @@ +// Verify that the only debuginfo generated are the line tables. +// +// ignore-windows +// compile-flags: -C debuginfo=line-tables-only + +#[repr(C)] +struct StructType { + a: i64, + b: i32 +} + +extern "C" { + fn creator() -> *mut StructType; + fn save(p: *const StructType); +} + +fn main() { + unsafe { + let value: &mut StructType = &mut* creator(); + value.a = 7; + save(value as *const StructType) + } +} + +// CHECK: !DICompileUnit +// CHECK: emissionKind: LineTablesOnly +// CHECK: !DILocation +// CHECK-NOT: !DIBasicType diff --git a/tests/rustdoc-ui/c-help.stdout b/tests/rustdoc-ui/c-help.stdout index 75b2e2a2a43..0bd2d73efee 100644 --- a/tests/rustdoc-ui/c-help.stdout +++ b/tests/rustdoc-ui/c-help.stdout @@ -3,7 +3,7 @@ -C codegen-units=val -- divide crate into N units to optimize in parallel -C control-flow-guard=val -- use Windows Control Flow Guard (default: no) -C debug-assertions=val -- explicitly enable the `cfg(debug_assertions)` directive - -C debuginfo=val -- debug info emission level (0 = no debug info, 1 = line tables only, 2 = full debug info with variable and type information; default: 0) + -C debuginfo=val -- debug info emission level (0-2, none, line-directives-only, line-tables-only, limited, or full; default: 0) -C default-linker-libraries=val -- allow the linker to link its default libraries (default: no) -C embed-bitcode=val -- emit bitcode in rlibs (default: yes) -C extra-filename=val -- extra data to put in each output filename