[runtimes] Pass COMPILER_RT* through to runtime build

[russell.gallop]

Summary

Without this COMPILER_RT_BUILD_SANITIZERS=OFF etc. would not work with cross compilation (e.g. with LLVM_ENABLE_RUNTIMES=compiler-rt)

[phosek]

This needs be done on a per-target basis, not globally (e.g. you may want to use COMPILER_RT_BUILD_SANITIZERS=OFF for target1 but not target2). Have you tried setting RUNTIMES_${target}_COMPILER_RT_BUILD_SANITIZERS=OFF? This should be already supported, see for example https://github.com/llvm/llvm-project/blob/master/clang/cmake/caches/Fuchsia-stage2.cmake#L100

[russell.gallop]

In D80442#2061115, @phosek wrote:

This needs be done on a per-target basis, not globally (e.g. you may want to use COMPILER_RT_BUILD_SANITIZERS=OFF for target1 but not target2). Have you tried setting RUNTIMES_${target}_COMPILER_RT_BUILD_SANITIZERS=OFF? This should be already supported, see for example https://github.com/llvm/llvm-project/blob/master/clang/cmake/caches/Fuchsia-stage2.cmake#L100

Thanks, that works, and looks better so I'll close this review.

llvm/runtimes/CMakeLists.txt

llvm_ExternalProject_Add(runtimes-${name}
                                         -DCMAKE_CXX_COMPILER_TARGET=${target}
                                         -DCMAKE_ASM_COMPILER_TARGET=${target}
                                         -DCMAKE_C_COMPILER_WORKS=ON
                                         -DCMAKE_CXX_COMPILER_WORKS=ON
                                         -DCMAKE_ASM_COMPILER_WORKS=ON
                                         -DCOMPILER_RT_DEFAULT_TARGET_ONLY=ON
                                         -DLLVM_RUNTIMES_TARGET=${name}
                                         ${${name}_extra_args}
+                             PASSTHROUGH_PREFIXES COMPILER_RT
                              TOOLCHAIN_TOOLS clang lld llvm-ar llvm-lipo llvm-ranlib llvm-nm llvm-objcopy llvm-objdump llvm-strip
                              EXTRA_TARGETS ${${name}_extra_targets}
                                            ${${name}_test_targets}
                              USE_TOOLCHAIN
                              ${EXTRA_ARGS})
   endfunction()
 
   if(runtimes)