list_cpu_feature doesn't build on Apple M1

[jwatte]

Note that Apple no longer sells new x64 MacBooks. It's literally impossible to get a new x64 MacBook for an engineer joining a team.

Using CMake 3.22

When doing a git clone [email protected]:google/cpu_features && cd cpu_features && mkdir build && cd build && cmake ../ && make I get the following build errors:

Cloning into 'cpu_features'...
remote: Enumerating objects: 1476, done.
remote: Counting objects: 100% (473/473), done.
remote: Compressing objects: 100% (258/258), done.
remote: Total 1476 (delta 261), reused 349 (delta 197), pack-reused 1003
Receiving objects: 100% (1476/1476), 522.02 KiB | 1.81 MiB/s, done.
Resolving deltas: 100% (922/922), done.
jwatte@Jons-MBP ~ % cd cpu_features 
jwatte@Jons-MBP cpu_features % ls
CMakeLists.txt	LICENSE		ci		include		scripts		test
CONTRIBUTING.md	README.md	cmake		ndk_compat	src
jwatte@Jons-MBP cpu_features % mkdir build
jwatte@Jons-MBP cpu_features % cd build 
jwatte@Jons-MBP build % cmake ..
-- The C compiler identification is AppleClang 13.0.0.13000029
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Library/Developer/CommandLineTools/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Looking for dlfcn.h
-- Looking for dlfcn.h - found
-- Looking for getauxval
-- Looking for getauxval - not found
-- The CXX compiler identification is AppleClang 13.0.0.13000029
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Library/Developer/CommandLineTools/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 2.8.12 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


-- Configuring done
-- Generating done
-- Build files have been written to: /Users/jwatte/cpu_features/build/googletest-download
[ 11%] Creating directories for 'googletest'
[ 22%] Performing download step (git clone) for 'googletest'
Cloning into 'googletest-src'...
Already on 'main'
Your branch is up to date with 'origin/main'.
[ 33%] Performing update step for 'googletest'
HEAD is now at 71d4e2f7 Makes TestForDeathTest.CRTDebugDeath only run when _DEBUG is defined
[ 44%] No patch step for 'googletest'
[ 55%] No configure step for 'googletest'
[ 66%] No build step for 'googletest'
[ 77%] No install step for 'googletest'
[ 88%] No test step for 'googletest'
[100%] Completed 'googletest'
[100%] Built target googletest
-- Found Python: /opt/homebrew/Frameworks/Python.framework/Versions/3.9/bin/python3.9 (found version "3.9.9") found components: Interpreter 
-- Looking for pthread.h
-- Looking for pthread.h - found
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/jwatte/cpu_features/build
jwatte@Jons-MBP build % make
[  2%] Building C object CMakeFiles/utils.dir/src/filesystem.c.o
[  4%] Building C object CMakeFiles/utils.dir/src/stack_line_reader.c.o
[  6%] Building C object CMakeFiles/utils.dir/src/string_view.c.o
[  6%] Built target utils
[  9%] Building C object CMakeFiles/unix_based_hardware_detection.dir/src/hwcaps.c.o
[  9%] Built target unix_based_hardware_detection
[ 11%] Building C object CMakeFiles/cpu_features.dir/src/impl_aarch64_linux_or_android.c.o
[ 13%] Building C object CMakeFiles/cpu_features.dir/src/impl_arm_linux_or_android.c.o
[ 15%] Building C object CMakeFiles/cpu_features.dir/src/impl_mips_linux_or_android.c.o
[ 18%] Building C object CMakeFiles/cpu_features.dir/src/impl_ppc_linux.c.o
[ 20%] Building C object CMakeFiles/cpu_features.dir/src/impl_x86_freebsd.c.o
[ 22%] Building C object CMakeFiles/cpu_features.dir/src/impl_x86_linux_or_android.c.o
[ 25%] Building C object CMakeFiles/cpu_features.dir/src/impl_x86_macos.c.o
[ 27%] Building C object CMakeFiles/cpu_features.dir/src/impl_x86_windows.c.o
[ 29%] Linking C static library libcpu_features.a
[ 29%] Built target cpu_features
[ 31%] Building C object CMakeFiles/list_cpu_features.dir/src/utils/list_cpu_features.c.o
[ 34%] Linking C executable list_cpu_features
Undefined symbols for architecture arm64:
  "_GetAarch64FeaturesEnumName", referenced from:
      _main in list_cpu_features.c.o
  "_GetAarch64FeaturesEnumValue", referenced from:
      _main in list_cpu_features.c.o
  "_GetAarch64Info", referenced from:
      _main in list_cpu_features.c.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make[2]: *** [list_cpu_features] Error 1
make[1]: *** [CMakeFiles/list_cpu_features.dir/all] Error 2
make: *** [all] Error 2

So, the architecture here is arm64 not aarch64, which is unfortunate, but a fact of life.
I imagine the easiest fix might be to patch that up to alias. There was at least one other patch to do that, #150, which has been open for over a year.
And, because the world is what it is, this means that building MacOS installers for electron apps no longer works.
Just sayin'.

[Mizux]

Feel free to send us a patch to:

cpu_features/src/utils/list_cpu_features.c

Lines 199 to 201 in 69d3993

	#elif defined(CPU_FEATURES_ARCH_AARCH64)
	DEFINE_ADD_FLAGS(GetAarch64FeaturesEnumValue, GetAarch64FeaturesEnumName,
	Aarch64Features, AARCH64_LAST_)

here we should split this code in

#elif defined(CPU_FEATURES_ARCH_AARCH64)  && defined(CPU_FEATURES_OS_MACOS)
....
#elif defined(CPU_FEATURES_ARCH_AARCH64)  && !defined(CPU_FEATURES_OS_MACOS)
...

ref:

cpu_features/include/cpu_features_macros.h

Lines 87 to 97 in 69d3993

	#if (defined(__apple__) || defined(__APPLE__) || defined(__MACH__))
	// From https://stackoverflow.com/a/49560690
	#include "TargetConditionals.h"
	#if defined(TARGET_OS_OSX)
	#define CPU_FEATURES_OS_MACOS
	#endif
	#if defined(TARGET_OS_IPHONE)
	// This is set for any non-Mac Apple products (IOS, TV, WATCH)
	#define CPU_FEATURES_OS_IPHONE
	#endif
	#endif

Otherwise CMake seems to correctly detect arm64 architecture and build for it.
note: You should consider to use cmake -S. -Bbuild && cmake --build build -v instead of creating the build dir by hand and call make directly....

[Mizux]

ugly workaround: disable the build of list_cpu_features
aka comment out the lines:

cpu_features/CMakeLists.txt

Lines 149 to 151 in 69d3993

	add_executable(list_cpu_features ${PROJECT_SOURCE_DIR}/src/utils/list_cpu_features.c)
	target_link_libraries(list_cpu_features PRIVATE cpu_features)
	add_executable(CpuFeature::list_cpu_features ALIAS list_cpu_features)