Minor CMake refactoring

[george.karpenkov]

Summary

Generalize clang_compile to work with objective C files.

Part of simplifying
https://reviews.llvm.org/D36116

[george.karpenkov]

@vitalybuka any comments? I'm not sure I'm able to split any other meaningful chunks.

[vitalybuka]

Could please land small accepted patches and rebase the large one?

cmake/Modules/CompilerRTCompile.cmake

macro(sanitizer_test_compile obj_list source arch)
   list(APPEND ${obj_list} ${output_obj})
 endmacro()
 
 # Compile a source into an object file with COMPILER_RT_TEST_COMPILER using
 # a provided compile flags and dependenices.
 # clang_compile(<object> <source>
 #               CFLAGS <list of compile flags>
 #               DEPS <list of dependencies>)
-macro(clang_compile object_file source)
+function(clang_compile object_file source)
   cmake_parse_arguments(SOURCE "" "" "CFLAGS;DEPS" ${ARGN})
   get_filename_component(source_rpath ${source} REALPATH)
   if(NOT COMPILER_RT_STANDALONE_BUILD)
     list(APPEND SOURCE_DEPS clang compiler-rt-headers)
   endif()
   if (TARGET CompilerRTUnitTestCheckCxx)
     list(APPEND SOURCE_DEPS CompilerRTUnitTestCheckCxx)
   endif()
   string(REGEX MATCH "[.](cc|cpp)$" is_cxx ${source_rpath})
+  string(REGEX MATCH "[.](m|mm)$" is_objc ${source_rpath})
   if(is_cxx)
     string(REPLACE " " ";" global_flags "${CMAKE_CXX_FLAGS}")
   else()
     string(REPLACE " " ";" global_flags "${CMAKE_C_FLAGS}")
   endif()
 
   if (MSVC)
     translate_msvc_cflags(global_flags "${global_flags}")
   endif()
 
   if (APPLE)
     set(global_flags ${OSX_SYSROOT_FLAG} ${global_flags})
   endif()
+  if (is_objc)
+    list(APPEND global_flags -ObjC)
+  endif()
 
   # Ignore unknown warnings. CMAKE_CXX_FLAGS may contain GCC-specific options
   # which are not supported by Clang.
   list(APPEND global_flags -Wno-unknown-warning-option)
   set(compile_flags ${global_flags} ${SOURCE_CFLAGS})
   add_custom_command(
     OUTPUT ${object_file}
     COMMAND ${COMPILER_RT_TEST_COMPILER} ${compile_flags} -c
             -o "${object_file}"
             ${source_rpath}
     MAIN_DEPENDENCY ${source}
     DEPENDS ${SOURCE_DEPS})
-endmacro()
+endfunction()
 
 # On Darwin, there are no system-wide C++ headers and the just-built clang is
 # therefore not able to compile C++ files unless they are copied/symlinked into
 # ${LLVM_BINARY_DIR}/include/c++
 # The just-built clang is used to build compiler-rt unit tests. Let's detect
 # this before we try to build the tests and print out a suggestion how to fix
 # it.
 # On other platforms, this is currently not an issue.

lib/asan/tests/CMakeLists.txt

set(ASAN_INST_TEST_SOURCES
   asan_interface_test.cc
   asan_internal_interface_test.cc
   asan_test.cc
   asan_oob_test.cc
   asan_mem_test.cc
   asan_str_test.cc
   asan_test_main.cc)
 if(APPLE)
-  list(APPEND ASAN_INST_TEST_SOURCES asan_mac_test.cc)
+  list(APPEND ASAN_INST_TEST_SOURCES asan_mac_test.cc asan_mac_test_helpers.mm)
 endif()
 
 set(ASAN_BENCHMARKS_SOURCES
   ${COMPILER_RT_GTEST_SOURCE}
   asan_benchmarks_test.cc)
 
 # Adds ASan unit tests and benchmarks for architecture.
 macro(add_asan_tests_for_arch_and_kind arch kind cflags)
   # Instrumented tests.
   set(ASAN_INST_TEST_OBJECTS)
   foreach(src ${ASAN_INST_TEST_SOURCES})
     asan_compile(ASAN_INST_TEST_OBJECTS ${src} ${arch} ${kind}
                  CFLAGS ${ASAN_UNITTEST_INSTRUMENTED_CFLAGS} ${cflags})
   endforeach()
-  if (APPLE)
-    # Add Mac-specific helper.
-    asan_compile(ASAN_INST_TEST_OBJECTS asan_mac_test_helpers.mm ${arch} ${kind}
-                 CFLAGS ${ASAN_UNITTEST_INSTRUMENTED_CFLAGS} -ObjC ${cflags})
-  endif()
 
   if (MSVC)
     # With the MSVC CRT, the choice between static and dynamic CRT is made at
     # compile time with a macro. Simulate the effect of passing /MD to clang-cl.
     set(ASAN_INST_DYNAMIC_TEST_OBJECTS)
     foreach(src ${ASAN_INST_TEST_SOURCES})
       asan_compile(ASAN_INST_DYNAMIC_TEST_OBJECTS ${src} ${arch} ${kind}
         CFLAGS ${ASAN_UNITTEST_INSTRUMENTED_CFLAGS} -D_MT -D_DLL ${cflags})