Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

do not emit .debug_pubnames .debug_pubtypes on Linux #94181

Closed
wants to merge 1 commit into from

Conversation

csmoe
Copy link
Member

@csmoe csmoe commented Feb 20, 2022

Cherry-pick from @tromey
Closes #48762

@rustbot rustbot added the T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. label Feb 20, 2022
@rust-highfive
Copy link
Collaborator

r? @petrochenkov

(rust-highfive has picked a reviewer for you, use r? to override)

@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 20, 2022
@rust-log-analyzer

This comment was marked as outdated.

@rust-log-analyzer

This comment has been minimized.

compiler/rustc_codegen_llvm/src/llvm/ffi.rs Outdated Show resolved Hide resolved
compiler/rustc_codegen_llvm/src/llvm/ffi.rs Outdated Show resolved Hide resolved
compiler/rustc_session/src/options.rs Outdated Show resolved Hide resolved
@petrochenkov
Copy link
Contributor

petrochenkov commented Feb 20, 2022

I have no idea whether this option should exist or not, and what default value it should have, so I only left some generic comments.
This PR needs to be sent to the debuginfo working group for a proper review.

@petrochenkov petrochenkov added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 20, 2022
@rust-log-analyzer

This comment has been minimized.

@rust-log-analyzer

This comment has been minimized.

@rust-log-analyzer
Copy link
Collaborator

The job x86_64-gnu-llvm-12 failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)
   Compiling rustc_macros v0.1.0 (/checkout/compiler/rustc_macros)
   Compiling chalk-derive v0.76.0
The following warnings were emitted during compilation:

warning: llvm-wrapper/RustWrapper.cpp: In function ‘llvm::DICompileUnit::DebugNameTableKind fromRust(LLVMRustDebugNameTableKind)’:
warning: llvm-wrapper/RustWrapper.cpp:717:47: error: ‘Gnu’ is not a member of ‘llvm::DICompileUnit::DebugNameTableKind’
warning:   717 |     return DICompileUnit::DebugNameTableKind::Gnu;
warning:       |                                               ^~~
warning: llvm-wrapper/RustWrapper.cpp: In function ‘LLVMOpaqueMetadata* LLVMRustDIBuilderCreateCompileUnit(LLVMRustDIBuilderRef, unsigned int, LLVMMetadataRef, const char*, size_t, bool, const char*, unsigned int, const char*, size_t, LLVMRustDebugEmissionKind, uint64_t, bool, LLVMRustDebugNameTableKind)’:
warning: llvm-wrapper/RustWrapper.cpp:802:85: error: expected ‘)’ before ‘;’ token
warning:   802 |                                          DebugInfoForProfiling, fromRust(TableKind));
warning:       |                                                                                     )
warning: llvm-wrapper/RustWrapper.cpp:798:14: note: to match this ‘(’
warning: llvm-wrapper/RustWrapper.cpp:798:14: note: to match this ‘(’
warning:   798 |   return wrap(Builder->createCompileUnit(Lang, File, StringRef(Producer, ProducerLen),

error: failed to run custom build command for `rustc_llvm v0.0.0 (/checkout/compiler/rustc_llvm)`

Caused by:
Caused by:
  process didn't exit successfully: `/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/release/build/rustc_llvm-c5c973c13747b49c/build-script-build` (exit status: 1)
  --- stdout
  cargo:rerun-if-env-changed=RUST_CHECK
  cargo:rerun-if-env-changed=REAL_LIBRARY_PATH_VAR
  cargo:rerun-if-env-changed=REAL_LIBRARY_PATH
  cargo:rerun-if-env-changed=LLVM_CONFIG
  cargo:rerun-if-changed=/usr/lib/llvm-12/bin/llvm-config
  cargo:rustc-cfg=llvm_component="aarch64"
  cargo:rustc-cfg=llvm_component="amdgpu"
  cargo:rustc-cfg=llvm_component="arm"
  cargo:rustc-cfg=llvm_component="asmparser"
  cargo:rustc-cfg=llvm_component="avr"
  cargo:rustc-cfg=llvm_component="bitreader"
  cargo:rustc-cfg=llvm_component="bitwriter"
  cargo:rustc-cfg=llvm_component="bpf"
  cargo:rustc-cfg=llvm_component="coverage"
  cargo:rustc-cfg=llvm_component="hexagon"
  cargo:rustc-cfg=llvm_component="instrumentation"
  cargo:rustc-cfg=llvm_component="ipo"
  cargo:rustc-cfg=llvm_component="linker"
  cargo:rustc-cfg=llvm_component="lto"
  cargo:rustc-cfg=llvm_component="mips"
  cargo:rustc-cfg=llvm_component="msp430"
  cargo:rustc-cfg=llvm_component="nvptx"
  cargo:rustc-cfg=llvm_component="powerpc"
  cargo:rustc-cfg=llvm_component="riscv"
  cargo:rustc-cfg=llvm_component="sparc"
  cargo:rustc-cfg=llvm_component="systemz"
  cargo:rustc-cfg=llvm_component="webassembly"
  cargo:rustc-cfg=llvm_component="x86"
  cargo:rerun-if-env-changed=LLVM_RUSTLLVM
  cargo:rerun-if-env-changed=LLVM_NDEBUG
  cargo:rerun-if-changed=llvm-wrapper/PassWrapper.cpp
  cargo:rerun-if-changed=llvm-wrapper/ArchiveWrapper.cpp
  cargo:rerun-if-changed=llvm-wrapper/CoverageMappingWrapper.cpp
  cargo:rerun-if-changed=llvm-wrapper/LLVMWrapper.h
  cargo:rerun-if-changed=llvm-wrapper/RustWrapper.cpp
  cargo:rerun-if-changed=llvm-wrapper/.editorconfig
  cargo:rerun-if-changed=llvm-wrapper/README
  cargo:rerun-if-changed=llvm-wrapper/Linker.cpp
  TARGET = Some("x86_64-unknown-linux-gnu")
  OPT_LEVEL = Some("3")
  HOST = Some("x86_64-unknown-linux-gnu")
  CXX_x86_64-unknown-linux-gnu = Some("sccache c++")
  CXXFLAGS_x86_64-unknown-linux-gnu = Some("-ffunction-sections -fdata-sections -fPIC -m64")
  CRATE_CC_NO_DEFAULTS = None
  CARGO_CFG_TARGET_FEATURE = Some("fxsr,sse,sse2")
  running: "sccache" "c++" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "-I/usr/lib/llvm-12/include" "-std=c++14" "-fno-exceptions" "-D_GNU_SOURCE" "-D__STDC_CONSTANT_MACROS" "-D__STDC_FORMAT_MACROS" "-D__STDC_LIMIT_MACROS" "-DLLVM_COMPONENT_AARCH64" "-DLLVM_COMPONENT_AMDGPU" "-DLLVM_COMPONENT_ARM" "-DLLVM_COMPONENT_ASMPARSER" "-DLLVM_COMPONENT_AVR" "-DLLVM_COMPONENT_BITREADER" "-DLLVM_COMPONENT_BITWRITER" "-DLLVM_COMPONENT_BPF" "-DLLVM_COMPONENT_COVERAGE" "-DLLVM_COMPONENT_HEXAGON" "-DLLVM_COMPONENT_INSTRUMENTATION" "-DLLVM_COMPONENT_IPO" "-DLLVM_COMPONENT_LINKER" "-DLLVM_COMPONENT_LTO" "-DLLVM_COMPONENT_MIPS" "-DLLVM_COMPONENT_MSP430" "-DLLVM_COMPONENT_NVPTX" "-DLLVM_COMPONENT_POWERPC" "-DLLVM_COMPONENT_RISCV" "-DLLVM_COMPONENT_SPARC" "-DLLVM_COMPONENT_SYSTEMZ" "-DLLVM_COMPONENT_WEBASSEMBLY" "-DLLVM_COMPONENT_X86" "-DNDEBUG" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/build/rustc_llvm-a07adcddf35006a8/out/llvm-wrapper/PassWrapper.o" "-c" "llvm-wrapper/PassWrapper.cpp"
  exit status: 0
  running: "sccache" "c++" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "-I/usr/lib/llvm-12/include" "-std=c++14" "-fno-exceptions" "-D_GNU_SOURCE" "-D__STDC_CONSTANT_MACROS" "-D__STDC_FORMAT_MACROS" "-D__STDC_LIMIT_MACROS" "-DLLVM_COMPONENT_AARCH64" "-DLLVM_COMPONENT_AMDGPU" "-DLLVM_COMPONENT_ARM" "-DLLVM_COMPONENT_ASMPARSER" "-DLLVM_COMPONENT_AVR" "-DLLVM_COMPONENT_BITREADER" "-DLLVM_COMPONENT_BITWRITER" "-DLLVM_COMPONENT_BPF" "-DLLVM_COMPONENT_COVERAGE" "-DLLVM_COMPONENT_HEXAGON" "-DLLVM_COMPONENT_INSTRUMENTATION" "-DLLVM_COMPONENT_IPO" "-DLLVM_COMPONENT_LINKER" "-DLLVM_COMPONENT_LTO" "-DLLVM_COMPONENT_MIPS" "-DLLVM_COMPONENT_MSP430" "-DLLVM_COMPONENT_NVPTX" "-DLLVM_COMPONENT_POWERPC" "-DLLVM_COMPONENT_RISCV" "-DLLVM_COMPONENT_SPARC" "-DLLVM_COMPONENT_SYSTEMZ" "-DLLVM_COMPONENT_WEBASSEMBLY" "-DLLVM_COMPONENT_X86" "-DNDEBUG" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/build/rustc_llvm-a07adcddf35006a8/out/llvm-wrapper/RustWrapper.o" "-c" "llvm-wrapper/RustWrapper.cpp"
  cargo:warning=llvm-wrapper/RustWrapper.cpp: In function ‘llvm::DICompileUnit::DebugNameTableKind fromRust(LLVMRustDebugNameTableKind)’:
  cargo:warning=llvm-wrapper/RustWrapper.cpp:717:47: error: ‘Gnu’ is not a member of ‘llvm::DICompileUnit::DebugNameTableKind’
  cargo:warning=  717 |     return DICompileUnit::DebugNameTableKind::Gnu;
  cargo:warning=      |                                               ^~~
  cargo:warning=llvm-wrapper/RustWrapper.cpp: In function ‘LLVMOpaqueMetadata* LLVMRustDIBuilderCreateCompileUnit(LLVMRustDIBuilderRef, unsigned int, LLVMMetadataRef, const char*, size_t, bool, const char*, unsigned int, const char*, size_t, LLVMRustDebugEmissionKind, uint64_t, bool, LLVMRustDebugNameTableKind)’:
  cargo:warning=llvm-wrapper/RustWrapper.cpp:802:85: error: expected ‘)’ before ‘;’ token
  cargo:warning=  802 |                                          DebugInfoForProfiling, fromRust(TableKind));
  cargo:warning=      |                                                                                     ^
  cargo:warning=      |                                                                                     )
  cargo:warning=llvm-wrapper/RustWrapper.cpp:798:14: note: to match this ‘(’
  cargo:warning=  798 |   return wrap(Builder->createCompileUnit(Lang, File, StringRef(Producer, ProducerLen),
  cargo:warning=      |              ^

  --- stderr



  error occurred: Command "sccache" "c++" "-O3" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "-ffunction-sections" "-fdata-sections" "-fPIC" "-m64" "-I/usr/lib/llvm-12/include" "-std=c++14" "-fno-exceptions" "-D_GNU_SOURCE" "-D__STDC_CONSTANT_MACROS" "-D__STDC_FORMAT_MACROS" "-D__STDC_LIMIT_MACROS" "-DLLVM_COMPONENT_AARCH64" "-DLLVM_COMPONENT_AMDGPU" "-DLLVM_COMPONENT_ARM" "-DLLVM_COMPONENT_ASMPARSER" "-DLLVM_COMPONENT_AVR" "-DLLVM_COMPONENT_BITREADER" "-DLLVM_COMPONENT_BITWRITER" "-DLLVM_COMPONENT_BPF" "-DLLVM_COMPONENT_COVERAGE" "-DLLVM_COMPONENT_HEXAGON" "-DLLVM_COMPONENT_INSTRUMENTATION" "-DLLVM_COMPONENT_IPO" "-DLLVM_COMPONENT_LINKER" "-DLLVM_COMPONENT_LTO" "-DLLVM_COMPONENT_MIPS" "-DLLVM_COMPONENT_MSP430" "-DLLVM_COMPONENT_NVPTX" "-DLLVM_COMPONENT_POWERPC" "-DLLVM_COMPONENT_RISCV" "-DLLVM_COMPONENT_SPARC" "-DLLVM_COMPONENT_SYSTEMZ" "-DLLVM_COMPONENT_WEBASSEMBLY" "-DLLVM_COMPONENT_X86" "-DNDEBUG" "-o" "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0-rustc/x86_64-unknown-linux-gnu/release/build/rustc_llvm-a07adcddf35006a8/out/llvm-wrapper/RustWrapper.o" "-c" "llvm-wrapper/RustWrapper.cpp" with args "c++" did not execute successfully (status code exit status: 1).

warning: build failed, waiting for other jobs to finish...
error: build failed
Build completed unsuccessfully in 0:01:01

@bors
Copy link
Contributor

bors commented May 21, 2022

☔ The latest upstream changes (presumably #97239) made this pull request unmergeable. Please resolve the merge conflicts.

@JohnCSimon
Copy link
Member

@csmoe
Ping from triage: I'm closing this due to inactivity, Please reopen when you are ready to continue with this.
Note: if you do please open the PR BEFORE you push to it, else you won't be able to reopen - this is a quirk of github.
Thanks for your contribution.

@rustbot label: +S-inactive

@JohnCSimon JohnCSimon closed this Jan 29, 2023
@rustbot rustbot added the S-inactive Status: Inactive and waiting on the author. This is often applied to closed PRs. label Jan 29, 2023
bors added a commit to rust-lang-ci/rust that referenced this pull request Nov 17, 2023
[EXPERIMENT] fix: stop `emitting .debug_pubnames` and `.debug_pubtypes`

### DO NOT MERGE

---

A continuation of rust-lang#94181.
Fixes rust-lang#48762
MCP can be found in <rust-lang/compiler-team#688>.

`.debug_pubnames` and `.debug_pubtypes` are poorly designed and people
seldom use them. However, they take a considerable portion of size in
the final binary. This tells LLVM stop emitting those sections on
DWARFv4 or lower. DWARFv5 use `.debug_names` which is more concise
in size and performant for name lookup.
bors added a commit to rust-lang-ci/rust that referenced this pull request Dec 11, 2023
fix: stop `emitting .debug_pubnames` and `.debug_pubtypes`

A continuation of rust-lang#94181.
Fixes rust-lang#48762
MCP can be found in <rust-lang/compiler-team#688>.

`.debug_pubnames` and `.debug_pubtypes` are poorly designed and people
seldom use them. However, they take a considerable portion of size in
the final binary. This tells LLVM stop emitting those sections on
DWARFv4 or lower. DWARFv5 use `.debug_names` which is more concise
in size and performant for name lookup.

Some other no-really-useful personal notes:

<details><summary>Details</summary>
<p>

## Pepole saying they are not useful

* rust-lang#48762
* https://rust-lang.zulipchat.com/#narrow/stream/317568-t-compiler.2Fwg-debugging/topic/investigating.20debuginfo.20size/near/342713604
* `DwarfCompileUnit::hasDwarfPubSections()` — https://github.com/llvm/llvm-project/blob/f633f325a1b808d33ca9653ed373353549ddcde6/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp#L1477-L1494
* clang default to no debug name table when no option provided — https://github.com/llvm/llvm-project/blob/f633f325a1b808d33ca9653ed373353549ddcde6/clang/lib/Frontend/CompilerInvocation.cpp#L1819-L1824
* GCC explicitly says GDB doesn't use pub sections (`TARGET_WANT_DEBUG_PUB_SECTIONS` only be true on Darwin) — https://github.com/gcc-mirror/gcc/blob/5d2a360f0a541646abb11efdbabc33c6a04de7ee/gcc/target.def#L6985-L6990 and https://github.com/bminor/binutils-gdb/blob/319b460545dc79280e2904dcc280057cf71fb753/gold/dwarf_reader.h#L424-L427
* Probably the only place that makes use of pub section in lldb — https://github.com/llvm/llvm-project/blob/725115d7bba2faf3d0c21442f4661dea77b8a77c/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp#L2117-L2135

* "The -gsplit-dwarf option requires -ggnu-pubnames." — https://github.com/gcc-mirror/gcc/blob/5d2a360f0a541646abb11efdbabc33c6a04de7ee/gcc/opts.cc#L1205

* LLVM: Always emit `.debug_names` with dwarf 5 for Apple platforms — https://reviews.llvm.org/D118754

</p>
</details>
bors added a commit to rust-lang-ci/rust that referenced this pull request Dec 11, 2023
…wiser

fix: stop emitting `.debug_pubnames` and `.debug_pubtypes`

A continuation of rust-lang#94181.
Fixes rust-lang#48762
MCP can be found in <rust-lang/compiler-team#688>.

`.debug_pubnames` and `.debug_pubtypes` are poorly designed and people
seldom use them. However, they take a considerable portion of size in
the final binary. This tells LLVM stop emitting those sections on
DWARFv4 or lower. DWARFv5 use `.debug_names` which is more concise
in size and performant for name lookup.

Some other no-really-useful personal notes:

<details><summary>Details</summary>
<p>

## Pepole saying they are not useful

* rust-lang#48762
* https://rust-lang.zulipchat.com/#narrow/stream/317568-t-compiler.2Fwg-debugging/topic/investigating.20debuginfo.20size/near/342713604
* `DwarfCompileUnit::hasDwarfPubSections()` — https://github.com/llvm/llvm-project/blob/f633f325a1b808d33ca9653ed373353549ddcde6/llvm/lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp#L1477-L1494
* clang default to no debug name table when no option provided — https://github.com/llvm/llvm-project/blob/f633f325a1b808d33ca9653ed373353549ddcde6/clang/lib/Frontend/CompilerInvocation.cpp#L1819-L1824
* GCC explicitly says GDB doesn't use pub sections (`TARGET_WANT_DEBUG_PUB_SECTIONS` only be true on Darwin) — https://github.com/gcc-mirror/gcc/blob/5d2a360f0a541646abb11efdbabc33c6a04de7ee/gcc/target.def#L6985-L6990 and https://github.com/bminor/binutils-gdb/blob/319b460545dc79280e2904dcc280057cf71fb753/gold/dwarf_reader.h#L424-L427
* Probably the only place that makes use of pub section in lldb — https://github.com/llvm/llvm-project/blob/725115d7bba2faf3d0c21442f4661dea77b8a77c/lldb/source/Plugins/SymbolFile/DWARF/SymbolFileDWARF.cpp#L2117-L2135

* "The -gsplit-dwarf option requires -ggnu-pubnames." — https://github.com/gcc-mirror/gcc/blob/5d2a360f0a541646abb11efdbabc33c6a04de7ee/gcc/opts.cc#L1205

* LLVM: Always emit `.debug_names` with dwarf 5 for Apple platforms — https://reviews.llvm.org/D118754

</p>
</details>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
S-inactive Status: Inactive and waiting on the author. This is often applied to closed PRs. S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue.
Projects
None yet
Development

Successfully merging this pull request may close these issues.

Stop emitting .debug_pubnames and .debug_pubtypes into Linux object files and binaries
7 participants