Through using ndk-build, -Wno-unused-command-line-argument is passed in
somewhere in the pipeline and hides this warning.
The warning can be turned on with:
APP_CPPFLAGS := -Wunused-command-line-argument ...
and then when building, you can see:
C/C++: clang++: warning: argument unused during compilation: '-mfloat-abi=softfp' [-Wunused-command-line-argument]
C/C++: clang++: warning: argument unused during compilation: '-mfpu=neon' [-Wunused-command-line-argument]
C/C++: clang++: warning: argument unused during compilation: '-maes' [-Wunused-command-line-argument]
These are unused because both floating-point and NEON are required in
all standard ARMv8 implementations. [1] [2]
[1] https://developer.arm.com/documentation/den0024/a/AArch64-Floating-point-and-NEON
[2] https://stackoverflow.com/a/29891469
475281935e