CMake fails at detecting ASM COMPILER with latest ARMClang

[antoine-morvan]

Hello,

I was trying to build openblas 0.3.21 using the latest Arm Compiler for Linux 22.1 (former armclang). Its --version ouput changed, and the CMake fails at detecting the ASM compiler properly:

Checking whether the ASM compiler is ARMClang using "--version" did not match "armclang":
Arm C/C++/Fortran Compiler version 22.1 (build number 12) (based on LLVM 13.0.1)

Note: Although the ASM compiler remains unidentified, the C compiler is properly detected:

-- The C compiler identification is Clang 13.0.1
-- The ASM compiler identification is unknown

PS: I dont want to debate on wether ARMClang should be detected as ARMClang or Clang here :)

The CMake command then fails with:

CMake Error: CMAKE_ASM_COMPILER not set, after EnableLanguage
CMake Error at cmake/prebuild.cmake:1325 (try_compile):
  Failed to configure test project build system.
Call Stack (most recent call first):
  cmake/system.cmake:163 (include)
  CMakeLists.txt:93 (include)


-- Configuring incomplete, errors occurred!

Forcing the ASM COMPILER & COMPILER_ID can be used as workaround:

        -DCMAKE_ASM_COMPILER="$CC" \
        -DCMAKE_ASM_COMPILER_ID="Clang" \

Best.

[brada4]

It is cmake shortcoming for brand new compiler. Your report could help there, not here.
https://cmake.org/cmake/help/latest/variable/CMAKE_LANG_COMPILER_ID.html

[martin-frbg]

This is certainly relevant here, and I will provide a fix after testing.