This patch introduces support for Integrated Distributed ThinLTO (DTLTO)
in ELF LLD.
DTLTO enables the distribution of ThinLTO backend compilations via
external distribution systems, such as Incredibuild, during the
traditional link step: https://llvm.org/docs/DTLTO.html.
It is expected that users will invoke DTLTO through the compiler driver
(e.g., Clang) rather than calling LLD directly. A Clang-side interface
for DTLTO will be added in a follow-up patch.
Note: Bitcode members of archives (thin or non-thin) are not currently
supported. This will be addressed in a future change. As a consequence
of this lack of support, this patch is not sufficient to allow for
self-hosting an LLVM build with DTLTO. Theoretically,
--start-lib/--end-lib could be used instead of archives in a self-host
build. However, it's unclear how --start-lib/--end-lib can be easily
used with the LLVM build system.
Testing:
- ELF LLD `lit` test coverage has been added, using a mock distributor
to avoid requiring Clang.
- Cross-project `lit` tests cover integration with Clang.
For the design discussion of the DTLTO feature, see: #126654.
This adds support for the LoongArch ELF psABI v2.00 [1] relocation
model to LLD. The deprecated stack-machine-based psABI v1 relocs are not
supported.
The code is tested by successfully bootstrapping a Gentoo/LoongArch
stage3, complete with common GNU userland tools and both the LLVM and
GNU toolchains (GNU toolchain is present only for building glibc,
LLVM+Clang+LLD are used for the rest). Large programs like QEMU are
tested to work as well.
[1]: https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html
Reviewed By: MaskRay, SixWeining
Differential Revision: https://reviews.llvm.org/D138135
This reverts commit aa495214b39d475bab24b468de7a7c676ce9e366.
As discussed in https://github.com/llvm/llvm-project/issues/53475 this patch
allows for using LLD-as-a-lib. It also lets clients link only the drivers that
they want (see unit tests).
This also adds the unit test infra as in the other LLVM projects. Among the
test coverage, I've added the original issue from @krzysz00, see:
https://github.com/ROCmSoftwarePlatform/D108850-lld-bug-reproduction
Important note: this doesn't allow (yet) linking in parallel. This will come a
bit later hopefully, in subsequent patches, for COFF at least.
Differential revision: https://reviews.llvm.org/D119049
I wasn't able to find any docs for Mach-O in `lld/docs`, so here's an attempt at adding basic docs. One of my goals here is to make it easy for users who are unfamiliar with linkers to successfully use lld.
Reviewed By: #lld-macho, int3
Differential Revision: https://reviews.llvm.org/D132893
The outdated documentation diverges a lot from the current state of
COFF/Mach-O/ELF/wasm ports and may just confuse users. It is better rewriting
some if useful.
Tested with `ninja docs-lld-html`
Reviewed By: #lld-macho, lhames, Jez Ng
Differential Revision: https://reviews.llvm.org/D113432
Make it possible for lld users to provide a custom script that would help to
find missing libraries. A possible scenario could be:
% clang /tmp/a.c -fuse-ld=lld -loauth -Wl,--error-handling-script=/tmp/addLibrary.py
unable to find library -loauth
looking for relevant packages to provides that library
liboauth-0.9.7-4.el7.i686
liboauth-devel-0.9.7-4.el7.i686
liboauth-0.9.7-4.el7.x86_64
liboauth-devel-0.9.7-4.el7.x86_64
pix-1.6.1-3.el7.x86_64
Where addLibrary would be called with the missing library name as first argument
(in that case addLibrary.py oauth)
Differential Revision: https://reviews.llvm.org/D87758
LLD implements Linker Scripts as they are described in the GNU ld manual.
This description is far from a specification, with the only true reference
the GNU ld implementation, which has undocumented behaviour that can vary
from release to release.
To make it easy for people to switch between linkers we try to follow GNU
ld implementation details wherever possible. We reserve the right to make
our own decisions where the undocumented GNU ld behaviour is not
appropriate for LLD. We don't have a place to document these decisions and
it can be difficult for users to find out this information.
This file is a statement of the LLD implementation policy and will contain
intentional deviations from GNU ld.
The first patch that will add concrete details to this file is D75724
Differential Revision: https://reviews.llvm.org/D75921
This fixes most references to the paths:
llvm.org/svn/
llvm.org/git/
llvm.org/viewvc/
github.com/llvm-mirror/
github.com/llvm-project/
reviews.llvm.org/diffusion/
to instead point to https://github.com/llvm/llvm-project.
This is *not* a trivial substitution, because additionally, all the
checkout instructions had to be migrated to instruct users on how to
use the monorepo layout, setting LLVM_ENABLE_PROJECTS instead of
checking out various projects into various subdirectories.
I've attempted to not change any scripts here, only documentation. The
scripts will have to be addressed separately.
Additionally, I've deleted one document which appeared to be outdated
and unneeded:
lldb/docs/building-with-debug-llvm.txt
Differential Revision: https://reviews.llvm.org/D57330
llvm-svn: 352514
- fix minor grammar stuff (I'm not a native speaker either, but it's hopefully a net improvement)
- mention that lld/coff is used in production
- update AArch64, ARM to production quality
- remove lld/include/lld/Core/TODO.txt which looks outdated
Differential Revision: https://reviews.llvm.org/D56600
llvm-svn: 351030
This linker backend is still a work in progress but is
enough to link simple programs including linking against
library archives.
Differential Revision: https://reviews.llvm.org/D34851
llvm-svn: 318539
Looks like it is not allowed to have an .rst file in this directory
that does not belong to a document tree. I don't know why. This patch
adds a file back to fix a bot.
llvm-svn: 296087
The Native file format was designed to be the fastest on-memory or
on-disk file format for object files. The problem is that no one
is working on that. No LLVM tools can produce object files in
the Native, thus the feature of supporting the format is useless
in the linker.
This patch removes the Native file support. We can add it back
if we really want it in future.
llvm-svn: 234641
