This PR adds a new aarch64 android toolchain, which leverages the
existing crossSystem infrastructure and LLVM builders to generate a
working toolchain with minimal prebuilt components.
The only thing that is prebuilt is the bionic libc. This is because it
is practically impossible to compile bionic outside of an AOSP tree. I
tried and failed, braver souls may prevail. For now I just grab the
relevant binaries from https://android.googlesource.com/.
I also grab the msm kernel sources from there to generate headers. I've
included a minor patch to the existing kernel-headers derivation in
order to expose an internal function.
Everything else, from binutils up, is using stock code. Many thanks to
@Ericson2314 for his help on this, and for building such a powerful
system in the first place!
One motivation for this is to be able to build a toolchain which will
work on an aarch64 linux machine. To my knowledge, there is no existing
toolchain for an aarch64-linux builder and an aarch64-android target.
In 7869d16545 I got rid of the symlinking
by forcing `COMPILER_RT_OS_DIR` to always be the empty string. I thought
this was good because it just make compiler-rt be installed in a normal
way.
However, various LLVM tools expect the `COMPILER_RT_OS_DIR` to be set
normally, and fail to find things when they aren't in the expected lib
subdir.
Maybe it would be best to patch that too in the long term, but for now
we just undo this change.
Rust 1.50.0 incorporated a Cargo change (rust-lang/cargo#8937) in
which cargo vendor erroneously changed permissions of vendored
crates. This was fixed in Rust
1.51.0 (rust-lang/cargo#9131). Unfortunately, this means that all
cargoSha256/cargoHashes produced during the Rust 1.50.0 cycle are
potentially broken.
This change updates cargoSha256/cargoHash tree-wide.
Fixes#121994.
Before, clang was able to find some headers with a relative path to the
`-B` flag pointing near the unwrapped clang binary. But with multiple
outputs that doesn't work, so we use a "resource directory" as it done
later in the bootstrap.
