error: unknown target CPU 'armv7-a'

[shaders]

Hi,

I have a very simple script:
export ANDROID_NDK=/android-ndk-r8e
cmake -DCMAKE_TOOLCHAIN_FILE=/android-cmake/android.toolchain.cmake

everything works fine at this point but trying to run make I always receive the same error:
error: unknown target CPU 'armv7-a'

I have tried different toolchains using ANDROID_TOOLCHAIN_NAME, but the error is always the same.

Any ideas what could be wrong?

Thanks!

[shaders]

I have clang selected by default:

/Users/User/android-ndk-r8e/toolchains/llvm-3.1/prebuilt/darwin-x86/bin/clang -fexceptions -Wno-psabi --sysroot=/Users/User/android-ndk-r8e/platforms/android-8/arch-arm -fpic -funwind-tables -finline-limit=64 -fsigned-char -no-canonical-prefixes -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -fdata-sections -ffunction-sections -Wa,--noexecstack -isystem /Users/User/android-ndk-r8e/platforms/android-8/arch-arm/usr/include -isystem /Users/User/android-ndk-r8e/sources/cxx-stl/gnu-libstdc++/4.6/include -isystem /Users/User/android-ndk-r8e/sources/cxx-stl/gnu-libstdc++/4.6/libs/armeabi-v7a/include -o CMakeFiles/libzip.dir/lib/mkstemp.c.o -c mkstemp.c

[taka-no-me]

@shaders, thanks for the report!

At the moment toolchain requires CMAKE_BUILD_TYPE to be set to Release or Debug for the clang compiler.

[dreamzor]

Hi! I've got the same error with clang 3.3 and your toolchain :(

[chromaticbum]

The compiler needs a triplet, and there is code in there to set the triplet to get the proper CPU. Take a look at android.toolchain.cmake and look for the section where it talks about the ANDROID_ABI variable. You need to set this when you are running cmake. For example: "cmake -DCMAKE_TOOLCHAIN_FILE=$ANDTOOLCHAIN -DANDROID_TOOLCHAIN_NAME=$ANDROID_TOOLCHAIN_NAME -DANDROID_ABI=armeabi-v7a .." Here is a link: https://github.com/taka-no-me/android-cmake/blob/5db45cfb87fec180b74963d3680dd60d4d8d8c3a/android.toolchain.cmake#l74-91

[chromaticbum]

Or as taka suggested, add -DCMAKE_BUILD_TYPE=Release|Debug and this will set the triplet as well

[dreamzor]

Thanks, but I already tried that... here's the complete list of relevant cmake options:

-DANDROID_ABI="armeabi-v7a with NEON"
-DANDROID_TOOLCHAIN_NAME=arm-linux-androideabi-clang3.3
-DCMAKE_TOOLCHAIN_FILE=${TOOLCHAIN_DIR}/android.toolchain.cmake
-DCMAKE_BUILD_TYPE=Release 

I ended up compiling a standalone toolchain which worked (yay!) with this cmake toolchain (using make_standalone_toolchain.sh at android-ndk/build/tools, but it certainly would be so much better if 'out of the box' solution would work.

That's the clang instance being called:
android-ndk/toolchains/llvm-3.3/prebuilt/darwin-x86/bin/clang
Maybe it's not suitable for armeabi-v7a with NEON somehow?

[chromaticbum]

This worked for me:
export ANDTOOLCHAIN=/Users/hollin/ndk.workspace/android-cmake/android.toolchain.cmake
export ANDROID_TOOLCHAIN_NAME=arm-linux-androideabi-clang3.3
export ANDROID_NDK=~/Lib/Android/ndk # this is r9c

cmake -DCMAKE_TOOLCHAIN_FILE=$ANDTOOLCHAIN -DANDROID_TOOLCHAIN_NAME=$ANDROID_TOOLCHAIN_NAME -DANDROID_ABI="armeabi-v7a with NEON" -DCMAKE_BUILD_TYPE=Release ..

[dreamzor]

Thanks! That's weird, it looks exactly the same..

Do you have the same clang instance being called? (make VERBOSE=1 will tell) Because when I'm trying to manually compile a int main() { return 0; } program with -march=armv7-a flag using that clang executable, it shows me the same 'unknown target cpu' error.

[chromaticbum]

Make sure to specify -target armv7-none-linux-androideabi
If you are manually invoking clang.

[dreamzor]

Calling clang from this folder
android-ndk/toolchains/llvm-3.3/prebuilt/darwin-x86/bin
With these parameters
./clang++ -target armv7-none-linux-androideabi -march=armv7-a code.cpp
I'm getting this...
FATAL:/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../libexec/as/x86_64/as: I don't understand 'm' flag! clang: error: assembler command failed with exit code 1 (use -v to see invocation)

I feel that something is really wrong..

[chromaticbum]

This is getting a bit off topic. But you would learn a lot by running ndk-build V=1 on one of the sample projects. You will see all of the options that need to be passed in. Of particular importance are compiling with -fPIC and using the proper gcc toolchain. Pretty much just look at the output of ndk-build and see what it's doing then adapt to your files.

[dreamzor]

Ok, I'll take a look at that, thanks a lot!

[taka-no-me]

This problem should be gone with the latest update.