Building a Complete Toolchain

[thekief]

I wanted to introduce some changes to the LLVM toolchain for testing purposes and built a toolchain following the official guide [1]. I stumbled on an issue though, the wrapper bash scripts for clang, e.g.,

./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi22-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android30-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android27-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi27-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android21-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android24-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android16-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android17-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi28-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android27-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android29-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi17-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android23-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android18-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android31-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android22-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android22-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android23-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android21-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi23-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang

are not created. I looked into this and noticed that toolchain/prebuilts/ndk/r24/build/tools/make_standalone_toolchain.py builds thems. Further down it is written that:

make_standalone_toolchain.py is no longer necessary

So I was wondering if there is a new way to create the bash script wrapper or make_standalone_toolchain.py is still the way to go.

[1] https://android.googlesource.com/toolchain/llvm_android/+/master/README.md

[rprichard]

Running build.py in llvm_android creates a "toolchain prebuilt", like the clang-r487747c directory in:
https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86/+/refs/heads/master

The wrapper scripts with the API levels in them (the 24 in aarch64-linux-android24-clang) are actually created by the NDK build script (checkbuild.py, https://android.googlesource.com/platform/ndk/+/master/docs/Building.md).

See the "NDK" section in https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86/+/master/README.md, which describes how to update the NDK build script to use a different toolchain prebuilt.

The make_standalone_toolchain.py script copies the NDK and creates a few extra wrapper scripts like clang and clang++ scripts that target a specific Android triple. It's been more-or-less unnecessary for a few years now, because the triple-prefixed wrapper scripts created by checkbuild.py should be sufficient.

[nikijohnson77]

I wanted to introduce some changes to the LLVM toolchain for testing purposes and built a toolchain following the official guide [1]. I stumbled on an issue though, the wrapper bash scripts for clang, e.g.,

./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi22-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android30-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android27-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi27-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android21-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android24-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android16-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android17-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi28-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android27-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android29-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi17-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android23-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android18-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android31-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android22-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android22-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android23-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/i686-linux-android21-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi23-clang
./ndk/23.1.7779620/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang

are not created. I looked into this and noticed that toolchain/prebuilts/ndk/r24/build/tools/make_standalone_toolchain.py builds thems. Further down it is written that:

make_standalone_toolchain.py is no longer necessary

So I was wondering if there is a new way to create the bash script wrapper or make_standalone_toolchain.py is still the way to go.

[1]__ https://android.googlesource.com/toolchain/llvm_android/+/master/REAjDME.md