fix compile on Mac when HOMEBREW_PREFIX is /opt/homebrew (#197)

Signed-off-by: Enwei Jiao <[email protected]>

CMakeLists.txt

@@ -22,8 +22,13 @@ add_definitions( -DAUTO_INITIALIZE_EASYLOGGINGPP )
 if ( APPLE )
     set ( CMAKE_CROSSCOMPILING TRUE )
     set ( RUN_HAVE_GNU_POSIX_REGEX 0 )
-    set ( CMAKE_C_COMPILER "/usr/local/opt/llvm/bin/clang" )
-    set ( CMAKE_CXX_COMPILER "/usr/local/opt/llvm/bin/clang++" )
+    if ( DEFINED ENV{HOMEBREW_PREFIX} )
+        set( APPLE_LLVM_PREFIX $ENV{HOMEBREW_PREFIX} )
+    else()
+        set( APPLE_LLVM_PREFIX "/usr/local" )
+    endif()
+    set ( CMAKE_C_COMPILER "${APPLE_LLVM_PREFIX}/opt/llvm/bin/clang" )
+    set ( CMAKE_CXX_COMPILER "${APPLE_LLVM_PREFIX}/opt/llvm/bin/clang++" )
 endif ()
 
 set( CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/cmake" )
@@ -74,7 +79,7 @@ include( CheckCXXCompilerFlag )
 if ( ${CMAKE_SYSTEM_NAME} MATCHES "Darwin" )
     message(STATUS "MacOS")
     set ( MACOS TRUE )
-    set ( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -L/usr/local/opt/libomp/lib" )
+    set ( CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -L${APPLE_LLVM_PREFIX}/opt/libomp/lib" )
 elseif ( "${CMAKE_SYSTEM}" MATCHES "Linux" )
     message( STATUS "Linux")
     set ( LINUX TRUE )