Add support for macOS

[aaronfranke]

When I try to compile GodotPckTool using make on macOS, I get this output:

% make
cd build && cmake .. -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/aaronfranke/workspace/GodotPckTool/build
/Applications/Xcode.app/Contents/Developer/usr/bin/make -C build
Consolidate compiler generated dependencies of target pck
[ 16%] Building CXX object src/CMakeFiles/pck.dir/PckTool.cpp.o
[ 33%] Building CXX object src/CMakeFiles/pck.dir/FileFilter.cpp.o
[ 50%] Linking CXX static library libpck.a
[ 66%] Built target pck
[ 83%] Building CXX object src/CMakeFiles/godotpcktool.dir/main.cpp.o
[100%] Linking CXX executable godotpcktool
clang: error: invalid linker name in argument '-fuse-ld=gold'
clang: error: unsupported option '-static-libgcc'
make[3]: *** [src/godotpcktool] Error 1
make[2]: *** [src/CMakeFiles/godotpcktool.dir/all] Error 2
make[1]: *** [all] Error 2
make: *** [compile] Error 2

I'm not familiar with CMake, so I'm not sure how to add support for macOS. But I would greatly appreciate it, it would be useful to have when trying to debug a Mac build of my Godot project.

[hhyyrylainen]

Getting things compiling should be relatively easy by detecting apple platform in cmake and then not using the Linux specific flags. Just saying if someone wants to give this a go, as I have currently no need myself to get this working on mac.

[april]

You can use -fuse-ld=ld and drop the two static arguments and it builds fine for me on macOS.

--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -20,7 +20,7 @@ add_executable(godotpcktool main.cpp)
 target_link_libraries(godotpcktool PRIVATE pck)

 # Static standard lib
-target_link_libraries(godotpcktool PRIVATE -static-libgcc -static-libstdc++)
+target_link_libraries(godotpcktool PRIVATE)

 # Fully static executable
 if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
@@ -28,7 +28,7 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
 endif()

 if(NOT WIN32)
-  set_target_properties(godotpcktool PROPERTIES LINK_FLAGS_RELEASE "-s -fuse-ld=gold")
+  set_target_properties(godotpcktool PROPERTIES LINK_FLAGS_RELEASE "-s -fuse-ld=ld")
 else()
   set_target_properties(godotpcktool PROPERTIES LINK_FLAGS_RELEASE "-s")
 endif()