RackSDK.cmake

# Mapping of plugin build definitions from the Rack-SDK arch.mk, compile.mk, dep.mk and plugin.mk to CMake.
# From https://github.com/baconpaul/airwin2rack/blob/main/RackSDK.cmake

set(RACK_SDK_VERSION 2.4.0)
message(STATUS "Load RackSDK.cmake (mapping based on Rack-SDK-${RACK_SDK_VERSION})")

if ("${RACK_SDK_DIR}" STREQUAL "")
  message(FATAL_ERROR "Path to Rack SDK is missing! Add -DRACK_SDK_DIR=<PATH> to the cmake call.")
else ()
  message(STATUS "Using Rack-SDK in '${RACK_SDK_DIR}'")
endif ()

if (EXISTS "${RACK_SDK_DIR}/include/rack.hpp")
  message(STATUS "Found include/rack.hpp")
else()
  message(FATAL_ERROR "Rack SDK in ${RACK_SDK_DIR} missing include/rack.hpp")
endif()

if ("${PLUGIN_NAME}" STREQUAL "")
  message(FATAL_ERROR "PLUGIN_NAME variable not set! Add PLUGIN_NAME variable to the project CMakeLists.txt before including RackSDK.cmake.\
 The PLUGIN_NAME must correspond to the plugin slug, as defined in plugin.json.")
else ()
  message(STATUS "Using PLUGIN_NAME '${PLUGIN_NAME}'")
endif ()

if ("${ADDITIONAL_PLUGIN_DISTRIBUTABLES}" STREQUAL "")
  message(WARNING "ADDITIONAL_PLUGIN_DISTRIBUTABLES variable not set. For installing additional files into '${PLUGIN_NAME}'\
   folder add ADDITIONAL_PLUGIN_DISTRIBUTABLES variable to the project CMakeLists.txt before including RackSDK.cmake.")
endif ()

# Do not change the RACK_PLUGIN_LIB!
if (${CMAKE_OSX_ARCHITECTURES} MATCHES "arm64")
  # Some older versions of VCV Rack Beta ARM added -arm64 to the plugin name
  # set(RACK_PLUGIN_ARCH -arm64)
endif ()
set(RACK_PLUGIN_LIB plugin${RACK_PLUGIN_ARCH})

file(GLOB LICENSE LICENSE*)
set(PLUGIN_DISTRIBUTABLES plugin.json res ${LICENSE} ${ADDITIONAL_PLUGIN_DISTRIBUTABLES})

message(STATUS "PLUGIN_DISTRIBUTABLES: ${PLUGIN_DISTRIBUTABLES}")

# Since the plugin's compiler could be a different version than Rack's compiler, link libstdc++ and libgcc statically to avoid ABI issues.
add_link_options($<$<CXX_COMPILER_ID:GNU>:-static-libstdc++>)
add_link_options($<$<PLATFORM_ID:Linux>:-static-libgcc>)
add_compile_options($<IF:$<STREQUAL:${CMAKE_OSX_ARCHITECTURES},arm64>,-march=armv8-a+fp+simd,-march=nehalem>)

add_compile_options(-fvisibility=hidden $<$<COMPILE_LANGUAGE:CXX>:-fvisibility-inlines-hidden>)
# This is needed for Rack for DAWs.
# Static libs don't usually compiled with -fPIC, but since we're including them in a shared library, it's needed.
add_compile_options(-fPIC)
# Generate dependency files alongside the object files
# Not required with CMake
#add_compile_options(-MMD -MP)

# Debugger symbols. These are removed with `strip`.
add_compile_options(-g)
# Optimization
if (CMAKE_BUILD_TYPE STREQUAL "Debug")
  message(STATUS "Skipping Optimizations for Debug Build")
else()
  message(STATUS "Enabling Optimizations for Non-Debug Build")
  add_compile_options(-O3 -funsafe-math-optimizations -fno-omit-frame-pointer)
endif()
# Warnings
add_compile_options(-Wall -Wextra -Wno-unused-parameter)
# C++ standard
if (DEFINED CMAKE_CXX_STANDARD)
  message(STATUS "Retaining CMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD}")
else()
  set(CMAKE_CXX_STANDARD 11)
  message(STATUS "Defaulting CMAKE_CXX_STANDARD to ${CMAKE_CXX_STANDARD}")
endif()

add_library(${RACK_PLUGIN_LIB} MODULE)
set_target_properties(${RACK_PLUGIN_LIB} PROPERTIES PREFIX "")

add_library(RackSDK INTERFACE)
target_include_directories(RackSDK INTERFACE ${RACK_SDK_DIR}/include ${RACK_SDK_DIR}/dep/include)
target_link_directories(RackSDK INTERFACE ${RACK_SDK_DIR})
target_link_libraries(RackSDK INTERFACE Rack)
target_compile_definitions(RackSDK INTERFACE $<IF:$<STREQUAL:${CMAKE_OSX_ARCHITECTURES},arm64>,ARCH_ARM64,ARCH_X64>)

if (${CMAKE_SYSTEM_NAME} MATCHES "Windows")
  if (NOT MINGW)
    message(FATAL_ERROR "Rack plugin development environment is only supported for MSYS2/MinGW")
  endif ()
  target_compile_definitions(RackSDK INTERFACE ARCH_WIN _USE_MATH_DEFINES)
  target_compile_options(RackSDK INTERFACE -municode -Wsuggest-override)
  target_link_options(${RACK_PLUGIN_LIB} PUBLIC -static-libstdc++)
endif ()

if (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
  message(STATUS "Build Mac OSX Plugin for architecture ${CMAKE_OSX_ARCHITECTURES}")
  target_compile_definitions(RackSDK INTERFACE ARCH_MAC)
  if (${CMAKE_OSX_ARCHITECTURES} MATCHES "x86_64")
    add_compile_options(-arch x86_64)
  endif ()
  if (${CMAKE_OSX_ARCHITECTURES} MATCHES "arm64")
    add_compile_options(-arch arm64)
  endif ()
  set_target_properties(${RACK_PLUGIN_LIB} PROPERTIES SUFFIX ".dylib")
  set_target_properties(${RACK_PLUGIN_LIB} PROPERTIES LINK_FLAGS "-undefined dynamic_lookup")
endif ()

if (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
  target_compile_definitions(RackSDK INTERFACE ARCH_LIN)
  # This prevents static variables in the DSO (dynamic shared object) from being preserved after dlclose().
  target_compile_options(RackSDK INTERFACE -fno-gnu-unique)
  # When Rack loads a plugin, it symlinks /tmp/Rack2 to its system dir, so the plugin can link to libRack.
  target_compile_options(RackSDK INTERFACE -Wl,-rpath=/tmp/Rack2)
endif ()

target_link_libraries(${RACK_PLUGIN_LIB} PRIVATE RackSDK)

install(TARGETS ${RACK_PLUGIN_LIB} LIBRARY DESTINATION ${PROJECT_BINARY_DIR}/${PLUGIN_NAME} OPTIONAL)
install(DIRECTORY ${PROJECT_BINARY_DIR}/${PLUGIN_NAME}/ DESTINATION ${PLUGIN_NAME})
file(COPY ${PLUGIN_DISTRIBUTABLES} DESTINATION ${PLUGIN_NAME})

# A quick installation target to copy the plugin library and plugin.json into VCV Rack plugin folder for development.
# CMAKE_INSTALL_PREFIX needs to point to the VCV Rack plugin folder in user documents.
add_custom_target(build_plugin)
add_dependencies(build_plugin ${RACK_PLUGIN_LIB})

add_custom_target(build_plugin_quick_install
        COMMAND cmake -E copy $<TARGET_FILE:${RACK_PLUGIN_LIB}> ${CMAKE_INSTALL_PREFIX}/${PLUGIN_NAME}
        COMMAND cmake -E copy ${CMAKE_SOURCE_DIR}/plugin.json ${CMAKE_INSTALL_PREFIX}/${PLUGIN_NAME}
        )
add_dependencies(build_plugin_quick_install ${RACK_PLUGIN_LIB})