[compiler-rt] Fix cross build when multiple targets are enabled.

[gberry]

Summary

Fix cross build if COMPILER_RT_TEST_TARGET_ARCH is specified as a
different arch than LLVM_NATIVE_ARCH.

[samsonov]

What is the exact cmake invocation you're using, and what are the errors you see? ${COMPILER_RT_TEST_TARGET_ARCH} is supposed to be used, well, in testing. It probably shouldn't affect the set of architectures we're targeting.

cmake/config-ix.cmake

177

This doesn't seem right - arch may be deduced to be i386

[gberry]

Do you think x86|i[0-9]86 would be better?

[gberry]

I share your concern about using COMPILER_RT_TEST_TARGET_ARCH, but unless I'm missing something that seems to be how the compiler-rt cmake build is set up.

For some background, I'm trying to build compiler-rt on x86_64-linux targeting aarch64-linux, with a toolchain that is configured to support both X86 and AArch64 targets.
Without my change, the compiler-rt cmake config thinks I'm trying to build for x86, no matter how I set up my compiler & flag cmake variables.

[samsonov]

OK, we shouldn't really LLVM_NATIVE_ARCH either. I've submitted similar changes to this code in r247099, could you please check if they solve the problem for you?

[gberry]

r247099 resolves the issue for us. Thanks!

cmake/config-ix.cmake

 
 # Generate the COMPILER_RT_SUPPORTED_ARCH list.
 if(ANDROID)
   # Can't rely on LLVM_NATIVE_ARCH in cross-compilation.
   # Examine compiler output instead.
   detect_target_arch()
   set(COMPILER_RT_OS_SUFFIX "-android")
 elseif(NOT APPLE) # Supported archs for Apple platforms are generated later
-  if("${LLVM_NATIVE_ARCH}" STREQUAL "X86")
+  if("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "x86")
     if(NOT MSVC)
       test_target_arch(x86_64 "" "-m64")
       # FIXME: We build runtimes for both i686 and i386, as "clang -m32" may
       # target different variant than "$CMAKE_C_COMPILER -m32". This part should
       # be gone after we resolve PR14109.
       test_target_arch(i686 __i686__ "-m32")
       test_target_arch(i386 __i386__ "-m32")
     else()
       if (CMAKE_SIZEOF_VOID_P EQUAL 4)
         test_target_arch(i386 "" "")
       else()
         test_target_arch(x86_64 "" "")
       endif()
     endif()
-  elseif("${LLVM_NATIVE_ARCH}" STREQUAL "PowerPC")
+  elseif("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "powerpc")
     TEST_BIG_ENDIAN(HOST_IS_BIG_ENDIAN)
     if(HOST_IS_BIG_ENDIAN)
       test_target_arch(powerpc64 "" "-m64")
     else()
       test_target_arch(powerpc64le "" "-m64")
     endif()
-  elseif("${LLVM_NATIVE_ARCH}" STREQUAL "Mips")
+  elseif("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "mips")
     # Gcc doesn't accept -m32/-m64 so we do the next best thing and use
     # -mips32r2/-mips64r2. We don't use -mips1/-mips3 because we want to match
     # clang's default CPU's. In the 64-bit case, we must also specify the ABI
     # since the default ABI differs between gcc and clang.
     # FIXME: Ideally, we would build the N32 library too.
     if("${COMPILER_RT_TEST_TARGET_ARCH}" MATCHES "mipsel|mips64el")
       # regex for mipsel, mips64el
       test_target_arch(mipsel "" "-mips32r2" "--target=mipsel-linux-gnu")