hanchenye-llvm-project/lld
Jez Ng 3646ee503d [lld-macho] Refactor segment/section creation, sorting, and merging
Summary:
There were a few issues with the previous setup:

1. The section sorting comparator used a declarative map of section names to
  determine the correct order, but it turns out we need to match on more than
  just names -- in particular, an upcoming diff will sort based on whether the
  S_ZERO_FILL flag is set. This diff changes the sorter to a more imperative but
  flexible form.

2. We were sorting OutputSections stored in a MapVector, which left the
  MapVector in an inconsistent state -- the wrong keys map to the wrong values!
  In practice, we weren't doing key lookups (only container iteration) after the
  sort, so this was fine, but it was still a dubious state of affairs. This diff
  copies the OutputSections to a vector before sorting them.

3. We were adding unneeded OutputSections to OutputSegments and then filtering
  them out later, which meant that we had to remember whether an OutputSegment
  was in a pre- or post-filtered state. This diff only adds the sections to the
  segments if they are needed.

In addition to those major changes, two minor ones worth noting:

1. I renamed all OutputSection variable names to `osec`, to parallel `isec`.
  Previously we were using some inconsistent combination of `osec`, `os`, and
  `section`.

2. I added a check (and a test) for InputSections with names that clashed with
  those of our synthetic OutputSections.

Reviewers: #lld-macho

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D81887
2020-06-21 17:13:59 -07:00
..
COFF [CodeView] Revert 8374bf4363 and 403f953792 2020-06-18 16:18:46 -04:00
Common FileOutputBuffer.h - remove unused includes. NFC. 2020-05-28 14:38:12 +01:00
ELF [ELF] Refine LMA offset propagation rule in D76995 2020-06-19 09:11:33 -07:00
MachO [lld-macho] Refactor segment/section creation, sorting, and merging 2020-06-21 17:13:59 -07:00
MinGW [LLD/MinGW]: Expose --thinlto-cache-dir 2020-05-24 12:30:56 +03:00
cmake/modules lld: Let find_package(LLD) work 2020-05-14 09:59:53 -04:00
docs [ELF] Refine LMA offset propagation rule in D76995 2020-06-19 09:11:33 -07:00
include/lld [lld] As part of using inclusive language within the llvm 2020-06-19 21:50:14 -07:00
lib [lld] As part of using inclusive language within the llvm 2020-06-19 21:50:14 -07:00
test [lld-macho] Refactor segment/section creation, sorting, and merging 2020-06-21 17:13:59 -07:00
tools/lld Reland D78837 [lld] Remove special cases from default ld driver mode. 2020-04-29 14:45:44 -07:00
unittests
utils
wasm [lld][WebAssembly] Allow ctors functions that return values 2020-06-18 13:11:40 -07:00
.clang-format
.clang-tidy
.gitignore
CMakeLists.txt lld: Let find_package(LLD) work 2020-05-14 09:59:53 -04:00
CODE_OWNERS.TXT
LICENSE.TXT
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.