Fix Clang Detection

For several versions now, CMake by default refers to macOS’ Clang as AppleClang instead of just Clang, which would fail STREQUAL. Fixed by changing it to MATCHES.

Author: Lord-Kamina

CMakeLists.txt

@@ -193,7 +193,7 @@ else()
       if (GCC_RANLIB)
         set(CMAKE_RANLIB ${GCC_RANLIB})
       endif()
-    elseif("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang")
+    elseif("${CMAKE_C_COMPILER_ID}" MATCHES "Clang")
       include(llvm-toolchain)
     endif()
   endif()
@@ -218,7 +218,7 @@ else()
 endif()
 
 if (BENCHMARK_USE_LIBCXX)
-  if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+  if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
     add_cxx_compiler_flag(-stdlib=libc++)
   elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU" OR
           "${CMAKE_CXX_COMPILER_ID}" STREQUAL "Intel")

cmake/HandleGTest.cmake

@@ -5,7 +5,7 @@ macro(build_external_gtest)
   include(ExternalProject)
   set(GTEST_FLAGS "")
   if (BENCHMARK_USE_LIBCXX)
-    if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+    if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
       list(APPEND GTEST_FLAGS -stdlib=libc++)
     else()
       message(WARNING "Unsupported compiler (${CMAKE_CXX_COMPILER}) when using libc++")