The NDK provides prebuilt toolchain files in directories named for the
host architecture. The NDK build system calls this `HOST_TAG`.
Expose the value publicly for use by clients that need to pass it
to external tools.
Suggested-by: Ruslan Baratov <ruslan_baratov@yahoo.com>
When this variable is not set by the user or toolchain file, set it to
the default selected. This will be useful for client code that needs to
pass the value to an external tool that needs to find the same toolchain
in the NDK. Leave it empty for a standalone toolchain.
Suggested-by: Ruslan Baratov <ruslan_baratov@yahoo.com>
Add missing "unwind" and "atomic" libraries needed for this combination.
See `${ndk}/sources/cxx-stl/llvm-libc++/libs/armeabi/libc++.a` for the
libraries the NDK uses.
Issue: #16380
We use `-Werror` in the Android test builds to make sure there are
no warnings that we care about (e.g. unused flags). However, the
NDK r13 tools produce a warning about their own builtins:
```
<built-in>: In function 'float abs(float)':
<built-in>: warning: conflicts with previous declaration here [-Wattributes]
```
Suppress this warning so that we can continue using `-Werror` but
tolerate these warnings.
Brad King