977d62c33e
For arm64, llvm-mc emits relocations for the target function
address like so:
ltmp:
<CIE start>
...
<CIE end>
... multiple FDEs ...
<FDE start>
<target function address - (ltmp + pcrel offset)>
...
If any of the FDEs in `multiple FDEs` get dead-stripped, then `FDE start`
will move to an earlier address, and `ltmp + pcrel offset` will no longer
reflect an accurate pcrel value. To avoid this problem, we "canonicalize"
our relocation by adding an `EH_Frame` symbol at `FDE start`, and updating
the reloc to be `target function address - (EH_Frame + new pcrel offset)`.
Reviewed By: #lld-macho, Roger
Differential Revision: https://reviews.llvm.org/D124561
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.