d9ddd18544
This patch adds support for bitcode members of thin archives to DTLTO (https://llvm.org/docs/DTLTO.html) in ELF LLD. For DTLTO, bitcode identifiers must be valid paths to bitcode files on disk. Clang does not support archive inputs for ThinLTO backend compilations. This patch adjusts the identifier for bitcode members of thin archives in DTLTO links so that it is the path to the member file on disk, allowing such members to be supported in DTLTO. This patch is sufficient to allow for self-hosting an LLVM build with DTLTO when thin archives are used. Note: Bitcode members of non-thin archives remain unsupported. This will be addressed in a future change. Testing: - LLD lit test coverage has been added to check that the identifier is adjusted appropriately. - A cross-project lit test has been added to show that a DTLTO link can succeed when linking bitcode members of thin archives. For the design discussion of the DTLTO feature, see: #126654. (cherry picked from commit 673476d96bed306be6ed81a8174f481a9a4b2934)
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.