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llvm / llvm-project / lld / b5f5aa94e8f716a7056f9509018bf7c20fea1104
commitb5f5aa94e8f716a7056f9509018bf7c20fea1104[log] [tgz]
authorFangrui Song <i@maskray.me>Tue Mar 12 10:56:14 2024 -0700
committerCopybara-Service <copybara-worker@google.com>Tue Mar 12 10:57:17 2024 -0700
tree0d143dcd636ef32e9e1f74bd92d9a375da0fbca6
parent027a38a0d8f5a1c73b032a38ed4f2b147fdaec42 [diff]
[ELF] Add --compress-section to compress matched non-SHF_ALLOC sections

--compress-sections <section-glib>=[none|zlib|zstd] is similar to
--compress-debug-sections but applies to broader sections without the
SHF_ALLOC flag. lld will report an error if a SHF_ALLOC section is
matched. An interesting use case is to compress `.strtab`/`.symtab`,
which consume a significant portion of the file size (15.1% for a
release build of Clang).

An older revision is available at https://reviews.llvm.org/D154641 .
This patch focuses on non-allocated sections for safety. Moving
`maybeCompress` as D154641 does not handle STT_SECTION symbols for
`-r --compress-debug-sections=zlib` (see `relocatable-section-symbol.s`
from #66804).

Since different output sections may use different compression
algorithms, we need CompressedData::type to generalize
config->compressDebugSections.

GNU ld feature request: https://sourceware.org/bugzilla/show_bug.cgi?id=27452

Link: https://discourse.llvm.org/t/rfc-compress-arbitrary-sections-with-ld-lld-compress-sections/71674

Pull Request: https://github.com/llvm/llvm-project/pull/84855

GitOrigin-RevId: f1ca2a09671e4d4acc2bea362b39268ed7883b6d
11 files changed
tree: 0d143dcd636ef32e9e1f74bd92d9a375da0fbca6
  1. cmake/
  2. COFF/
  3. Common/
  4. docs/
  5. ELF/
  6. include/
  7. MachO/
  8. MinGW/
  9. test/
  10. tools/
  11. unittests/
  12. utils/
  13. wasm/
  14. .clang-format
  15. .clang-tidy
  16. .gitignore
  17. CMakeLists.txt
  18. CODE_OWNERS.TXT
  19. LICENSE.TXT
  20. README.md
README.md

LLVM Linker (lld)

This directory and its subdirectories contain source code for the LLVM Linker, a modular cross platform linker which is built as part of the LLVM compiler infrastructure project.

lld is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt.

Benchmarking

In order to make sure various developers can evaluate patches over the same tests, we create a collection of self contained programs.

It is hosted at https://s3-us-west-2.amazonaws.com/linker-tests/lld-speed-test.tar.xz

The current sha256 is 10eec685463d5a8bbf08d77f4ca96282161d396c65bd97dc99dbde644a31610f.