[compiler-rt][Fuchsia] Support building + running compiler-rt tests on fuchsia's host toolchain

[phosek]

@leonardchan would it be possible to break this up into 3 changes?

clang/cmake/caches/Fuchsia-stage2.cmake

123

This shouldn't be needed.

140

Don't we need the -static-libgcc flag here as well?

[leonardchan]

In D109199#2981174, @phosek wrote:

@leonardchan would it be possible to break this up into 3 changes?

Can do.

clang/cmake/caches/Fuchsia-stage2.cmake

123

So while we do build builtins, this is actually needed to run builtins tests: https://github.com/llvm/llvm-project/blob/ad7e12226f6b1ebf91511899016cdfb29aa8919e/compiler-rt/test/CMakeLists.txt#L59

140

When testing locally, there was actually a tsan test that wasn't working if -static-libgcc was here. I can try to reproduce it. I believe it had to do with static linking in an archive, but a particular object file in that archive wasn't getting linked in which changed some runtime logic and caused the test to fail.

[leonardchan]

clang/cmake/caches/Fuchsia-stage2.cmake

140

Oh ok. Disregard my last explanation. So the test is compiler-rt/test/tsan/Linux/check_memcpy.c, and the actual reason it failed is because the test just checks to make sure calls to memcpy/memset are not used at all (since tsan should intercept them and replace them with its own functions/code).

The issue is that if we statically link in an uninstrumented libunwind, then the test will fail bc it will find memcpy/set calls in that libunwind code. Removing the -static-libgcc seems to instead opt for dynamically linking against libunwind.so, and not linking in any uninstrumented code.

[leonardchan]

Split also into https://reviews.llvm.org/D109207 and https://reviews.llvm.org/D109208

[phosek]

clang/cmake/caches/Fuchsia-stage2.cmake

123

We are already build builtins in a separate build so I think we should be running the tests there rather than building the twice.

[leonardchan]

clang/cmake/caches/Fuchsia-stage2.cmake

123

Ah, I didn't know that. Removed.

[phosek]

LGTM

clang/cmake/caches/Fuchsia-stage2.cmake

if(APPLE)
   list(APPEND BUILTIN_TARGETS "default")
   list(APPEND RUNTIME_TARGETS "default")
 
   set(COMPILER_RT_ENABLE_TVOS OFF CACHE BOOL "")
   set(COMPILER_RT_ENABLE_WATCHOS OFF CACHE BOOL "")
   set(COMPILER_RT_USE_BUILTINS_LIBRARY ON CACHE BOOL "")
 
   set(LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
-  set(LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
   set(LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
   set(LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
   set(LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
   set(LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
   set(LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
   set(LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
   set(LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
   set(LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
if(LINUX_${target}_SYSROOT)
     set(RUNTIMES_${target}_CMAKE_C_FLAGS "--target=${target}" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_CXX_FLAGS "--target=${target}" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_ASM_FLAGS "--target=${target}" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SYSROOT ${LINUX_${target}_SYSROOT} CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_SHARED_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_MODULE_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
     set(RUNTIMES_${target}_CMAKE_EXE_LINKER_FLAGS "-fuse-ld=lld" CACHE STRING "")
     set(RUNTIMES_${target}_COMPILER_RT_USE_BUILTINS_LIBRARY ON CACHE BOOL "")
+    set(RUNTIMES_${target}_COMPILER_RT_CAN_EXECUTE_TESTS ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBUNWIND_USE_COMPILER_RT ON CACHE BOOL "")
-    set(RUNTIMES_${target}_LIBUNWIND_INSTALL_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_USE_LLVM_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_ENABLE_STATIC_UNWINDER ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXXABI_INSTALL_LIBRARY OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_USE_COMPILER_RT ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ENABLE_SHARED OFF CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ENABLE_STATIC_ABI_LIBRARY ON CACHE BOOL "")
     set(RUNTIMES_${target}_LIBCXX_ABI_VERSION 2 CACHE STRING "")
     set(RUNTIMES_${target}_LLVM_ENABLE_ASSERTIONS OFF CACHE BOOL "")
     set(RUNTIMES_${target}_SANITIZER_CXX_ABI "libc++" CACHE STRING "")
     set(RUNTIMES_${target}_SANITIZER_CXX_ABI_INTREE ON CACHE BOOL "")
+    set(RUNTIMES_${target}_COMPILER_RT_TEST_COMPILER_CFLAGS "--unwindlib=libunwind -static-libgcc" CACHE STRING "")
+    set(RUNTIMES_${target}_SANITIZER_COMMON_TEST_TARGET_CFLAGS "--unwindlib=libunwind -static-libgcc" CACHE STRING "")
+    set(RUNTIMES_${target}_TSAN_TEST_TARGET_CFLAGS "--unwindlib=libunwind" CACHE STRING "")
+    set(RUNTIMES_${target}_LLVM_TOOLS_DIR "${CMAKE_BINARY_DIR}/bin" CACHE BOOL "")
     set(RUNTIMES_${target}_LLVM_ENABLE_RUNTIMES "compiler-rt;libcxx;libcxxabi;libunwind" CACHE STRING "")
 
     # Use .build-id link.
     list(APPEND RUNTIME_BUILD_ID_LINK "${target}")
   endif()
 endforeach()
 
 if(FUCHSIA_SDK)