[Fuchsia][cmake] Avoid referencing cxx_shared in compiler-rt (llvm#112257)

After llvm#80007 Fuchsia builds are
now always building cxx_shared for arm64 and x64 Linux. Ultimately, this
is because the LIBCXX_ENABLE_SHARED is not used in compiler-rt to select
the correct libc++ target, and because cxx_shared is now always defined,
it is selected as a dependency when building runtimes tests.

---------

Co-authored-by: Petr Hosek <[email protected]>

Author: ilovepi

compiler-rt/CMakeLists.txt

@@ -621,7 +621,7 @@ if(COMPILER_RT_USE_LLVM_UNWINDER)
   if (COMPILER_RT_ENABLE_STATIC_UNWINDER)
     list(APPEND COMPILER_RT_UNWINDER_LINK_LIBS "$<TARGET_LINKER_FILE:unwind_static>")
   else()
-    list(APPEND COMPILER_RT_UNWINDER_LINK_LIBS "$<TARGET_LINKER_FILE:$<IF:$<TARGET_EXISTS:unwind_shared>,unwind_shared,unwind_static>>")
+    list(APPEND COMPILER_RT_UNWINDER_LINK_LIBS "$<TARGET_LINKER_FILE:$<IF:$<BOOL:${LIBUNWIND_ENABLE_SHARED}>,unwind_shared,unwind_static>>")
   endif()
 endif()
 
@@ -634,7 +634,7 @@ if (COMPILER_RT_CXX_LIBRARY STREQUAL "libcxx")
   if (COMPILER_RT_STATIC_CXX_LIBRARY)
     set(COMPILER_RT_CXX_LINK_LIBS "$<TARGET_LINKER_FILE:cxx_static>")
   else()
-    set(COMPILER_RT_CXX_LINK_LIBS "$<TARGET_LINKER_FILE:$<IF:$<TARGET_EXISTS:cxx_shared>,cxx_shared,cxx_static>>")
+    set(COMPILER_RT_CXX_LINK_LIBS "$<TARGET_LINKER_FILE:$<IF:$<BOOL:${LIBCXX_ENABLE_SHARED}>,cxx_shared,cxx_static>>")
   endif()
 elseif (COMPILER_RT_CXX_LIBRARY STREQUAL "none")
   # We aren't using any C++ standard library so avoid including the default one.
@@ -676,7 +676,7 @@ if (SANITIZER_TEST_CXX_LIBNAME STREQUAL "libc++")
     if (SANITIZER_USE_STATIC_TEST_CXX)
       list(APPEND SANITIZER_TEST_CXX_LIBRARIES "$<TARGET_LINKER_FILE:cxx_static>")
     else()
-      list(APPEND SANITIZER_TEST_CXX_LIBRARIES "$<TARGET_LINKER_FILE:$<IF:$<TARGET_EXISTS:cxx_shared>,cxx_shared,cxx_static>>")
+      list(APPEND SANITIZER_TEST_CXX_LIBRARIES "$<TARGET_LINKER_FILE:$<IF:$<BOOL:${LIBCXX_ENABLE_SHARED}>,cxx_shared,cxx_static>>")
     endif()
     # We are using the in tree libc++ so avoid including the default one.
     append_list_if(COMPILER_RT_HAS_NOSTDINCXX_FLAG -nostdinc++ COMPILER_RT_UNITTEST_CFLAGS)

compiler-rt/test/fuzzer/CMakeLists.txt

@@ -73,10 +73,10 @@ endmacro()
 
 test_fuzzer("default")
 if("${CMAKE_SYSTEM_NAME}" STREQUAL "Linux")
-  if(TARGET cxx_shared)
+  if(LIBCXX_ENABLE_SHARED)
     test_fuzzer("libc++" DEPS cxx_shared)
   endif()
-  if(TARGET cxx_static)
+  if(LIBCXX_ENABLE_STATIC)
     test_fuzzer("static-libc++" DEPS cxx_static)
   endif()
 endif()