The effect of `.out // { outputSpecified = false; }` in these cases
is to select the default output explicitly, but then make the
selection implicit until `overrideAttrs` is called. Previously
`overrideAttrs` would not preserve output selection, masking the
apparently unnecessary behavior of this workaround.
For `libllvm-polly`, this logic does not apply, as it does not
select the default output.
The `outputSpecified` workaround was introduced in
https://github.com/NixOS/nixpkgs/pull/122554
and was perhaps rushed because of a release deadline, and expected
delays from mass rebuilds.
The change in `overrideAttrs` behavior was added in
5b2f597b11 / https://github.com/NixOS/nixpkgs/pull/211685
and the problem was discovered in https://github.com/NixOS/nixpkgs/pull/218537,
which may contain further information.
FreeBSD doesn't use LLVM's cxxabi implementation, for backwards
compatibility reasons. Software expects the libcxxrt API when
building on FreeBSD. This fixes the build of
pkgsCross.x86_64-freebsd.boost.
As a first stop towards getting a bit more organized for #171047, add a
maintainer team and add myself and John Ericson as new members. Michael
Raskin asked to be removed.
A second step could be creating a github team additionally.
libcxxClang still depends on cc wrapper's gccForLibs for libgcc which is
not available when useLLVM is set. In such cases we need to switch to
clangUseLLVM and (try) to use compiler-rt instead.
Resolves#153759: pkgsLLVM.llvmPackages.stdenv now correctly
clangUseLLVM as cc, allowing compilation to work as expected.
llvmPackages_*.clang should check the default compiler for the package
set it is targeting (targetPackages.stdenv.cc) instead of the compiler
that has been used to build it (stdenv.cc) in order to get some sense of
whether to use libc++ or libstdc++.
Since we are now inspecting targetPackages in the llvmPackages.clang
attribute, we need to avoid using it in the cross stdenv — which just
forces us to explicitly request libcxxClang for darwin instead of
relying on the clang attribute to pick it for us.
We also need to do something similar for targetPackages.stdenv.cc: Here
the llvmPackages.clang logic would work as we want (inspect
targetPackages.stdenv.cc and if it doesn't exist, make the choice based
on stdenv.cc), but it gets locked in a cycle with the previous package.
We can easily break this, however: We know that the previous set had
clang and the next one doesn't exist, so we'd choose libcxxClang any day
of the week.
the fix to extendDerivation in #140051 unwittingly worsened eval performance by
quite a bit. set elements alone needed over 1GB extra after the change, which
seems disproportionate to how small it was. if we flip the logic used to
determine which outputs to install around and keep a "this one exactly" flag in
the specific outputs instead of a "all of them" in the root we can avoid most
of that cost.
The main thing was using `llvm_meta` in all versions.
Secondarily:
- libunwindx7: Forgot to split outputs
- libcxx{,abi} 12: Forgot to apply output-splitting patches.
- simplify `useLLVM` stdenv-switching logic.
- openmp always gets its own directory
Also begin to start work on cross compilation, though that will have to
be finished later.
The patches are based on the first version of
https://reviews.llvm.org/D99484. It's very annoying to do the
back-porting but the review has uncovered nothing super major so I'm
fine sticking with what I've got.
Beyond making the outputs work, I also strove to re-sync the packages,
as they have been drifting pointlessly apart for some time.
----
Other misc notes, highly incomplete
- lvm-config-native and llvm-config are put in `dev` because they are
tools just for build time.
- Clang no longer has an lld dep. That was introduced in
db29857eb3, but if clang needs help
finding lld when it is used we should just pass it flags / put in the
resource dir. Providing it at build time increases critical path
length for no good reason.
----
A note on `nativeCC`:
`stdenv` takes tools from the previous stage, so:
1. `pkgsBuildBuild`: `(?1, x, x)`
2. `pkgsBuildBuild.stdenv.cc`: `(?0, ?1, x)`
while:
1. `pkgsBuildBuild`: `(?1, x, x)`
2. `pkgsBuildBuild.targetPackages`: `(x, x, ?2)`
3. `pkgsBuildBuild.targetPackages.stdenv.cc`: `(?1, x, x)`
clang needs to find headers + libraries for compiling with libc++. We
need to add a libcxx argument to cc-wrapper. This means you do not
have to pass in c++ headers directly.
This resolves the last case remaining of #30670. Darwin clang++ now
works properly.
Fixes#30670
On darwin llvmPackages is built using python-boot to avoid dependencies
in the stdenv, but we can't and shouldn't use that when building the
manpages since it depends on python packages.
