To keep this for the future we also strictDeps where possible, including for janePackages, topkg, oasis and ocamlbuild.
This makes some closures significantly smaller and makes cross compilation easier
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)`
The opam patch makes ocaml link dependent executables with
-L${LLVM_OCAML_EXTERNAL_LLVM_LIBDIR}. This variable was previously
undefined and as a result the linker would previously be called with
just -L which makes it ignore the next argument. This would lead strange
linking errors, like missing caml_apply2.
Despite defining this variable correctly, propagating llvm is still
necessary for linking to complete. In case ocaml-llvm is a transitive
dependency only, propagatedBuildInputs is not enough. To avoid having to
guess which version of llvm was used, we provide the right one in
passthrough.
