cmake_minimum_required(VERSION 3.9)

if (NOT NODE_MODULE_MINIMUM_ABI)

set(NODE_MODULE_MINIMUM_ABI 46) # Don't build node modules for versions earlier than Node 4

endif()

if (NOT NODE_MODULE_CACHE_DIR)

set(NODE_MODULE_CACHE_DIR "${CMAKE_BINARY_DIR}")

endif()

function(_node_module_download _TYPE _URL _FILE)

file(REMOVE_RECURSE "${_FILE}")

string(RANDOM LENGTH 32 _TMP)

set(_TMP "${CMAKE_BINARY_DIR}/${_TMP}")

message(STATUS "[Node.js] Downloading ${_TYPE}...")

file(DOWNLOAD "${_URL}" "${_TMP}" STATUS _STATUS TLS_VERIFY ON)

list(GET _STATUS 0 _STATUS_CODE)

if(NOT _STATUS_CODE EQUAL 0)

file(REMOVE "${_TMP}")

list(GET _STATUS 1 _STATUS_MESSAGE)

message(FATAL_ERROR "[Node.js] Failed to download ${_TYPE}: ${_STATUS_MESSAGE}")

else()

get_filename_component(_DIR "${_FILE}" DIRECTORY)

file(MAKE_DIRECTORY "${_DIR}")

file(RENAME "${_TMP}" "${_FILE}")

endif()

endfunction()

function(_node_module_unpack_tar_gz _TYPE _URL _PATH _DEST)

string(RANDOM LENGTH 32 _TMP)

set(_TMP "${CMAKE_BINARY_DIR}/${_TMP}")

_node_module_download("${_TYPE}" "${_URL}" "${_TMP}.tar.gz")

file(REMOVE_RECURSE "${_DEST}" "${_TMP}")

file(MAKE_DIRECTORY "${_TMP}")

execute_process(COMMAND ${CMAKE_COMMAND} -E tar xfz "${_TMP}.tar.gz"

WORKING_DIRECTORY "${_TMP}"

RESULT_VARIABLE _STATUS_CODE

OUTPUT_VARIABLE _STATUS_MESSAGE

ERROR_VARIABLE _STATUS_MESSAGE)

if(NOT _STATUS_CODE EQUAL 0)

message(FATAL_ERROR "[Node.js] Failed to unpack ${_TYPE}: ${_STATUS_MESSAGE}")

endif()

get_filename_component(_DIR "${_DEST}" DIRECTORY)

file(MAKE_DIRECTORY "${_DIR}")

file(RENAME "${_TMP}/${_PATH}" "${_DEST}")

file(REMOVE_RECURSE "${_TMP}" "${_TMP}.tar.gz")

endfunction()

function(add_node_module NAME)

cmake_parse_arguments("" "" "MINIMUM_NODE_ABI;NAN_VERSION;INSTALL_PATH;CACHE_DIR" "EXCLUDE_NODE_ABIS" ${ARGN})

if(NOT _MINIMUM_NODE_ABI)

set(_MINIMUM_NODE_ABI "${NODE_MODULE_MINIMUM_ABI}")

endif()

if (NOT _CACHE_DIR)

set(_CACHE_DIR "${NODE_MODULE_CACHE_DIR}")

endif()

if (NOT _INSTALL_PATH)

set(_INSTALL_PATH "lib/{node_abi}/${NAME}.node")

endif()

get_filename_component(_CACHE_DIR "${_CACHE_DIR}" REALPATH BASE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")

if(_UNPARSED_ARGUMENTS)

message(WARNING "[Node.js] Unused arguments: '${_UNPARSED_ARGUMENTS}'")

endif()

# Create master target

add_library(${NAME} INTERFACE)

# Obtain a list of current Node versions and retrieves the latest version per ABI

if(NOT EXISTS "${_CACHE_DIR}/node/index.tab")

_node_module_download(

"Node.js version list"

"https://nodejs.org/dist/index.tab"

"${_CACHE_DIR}/node/index.tab"

)

endif()

file(STRINGS "${_CACHE_DIR}/node/index.tab" _INDEX_FILE)

list(REMOVE_AT _INDEX_FILE 0)

set(_ABIS)

foreach(_LINE IN LISTS _INDEX_FILE)

string(REGEX MATCHALL "[^\t]*\t" _COLUMNS "${_LINE}")

list(GET _COLUMNS 8 _ABI)

string(STRIP "${_ABI}" _ABI)

if((_ABI GREATER _MINIMUM_NODE_ABI OR _ABI EQUAL _MINIMUM_NODE_ABI) AND NOT _ABI IN_LIST _EXCLUDE_NODE_ABIS AND NOT DEFINED _NODE_ABI_${_ABI}_VERSION)

list(APPEND _ABIS ${_ABI})

list(GET _COLUMNS 0 _VERSION)

string(STRIP "${_VERSION}" _NODE_ABI_${_ABI}_VERSION)

endif()

endforeach()

# Install Nan

if(_NAN_VERSION AND NOT EXISTS "${_CACHE_DIR}/nan/${_NAN_VERSION}/nan.h")

_node_module_unpack_tar_gz(

"Nan ${_NAN_VERSION}"

"https://registry.npmjs.org/nan/-/nan-${_NAN_VERSION}.tgz"

"package"

"${_CACHE_DIR}/nan/${_NAN_VERSION}"

)

endif()

# Generate a target for every ABI

set(_TARGETS)

foreach(_ABI IN LISTS _ABIS)

set(_NODE_VERSION ${_NODE_ABI_${_ABI}_VERSION})

# Download the headers if we don't have them yet

if(NOT EXISTS "${_CACHE_DIR}/node/${_NODE_VERSION}/node.h")

_node_module_unpack_tar_gz(

"headers for Node ${_NODE_VERSION}"

"https://nodejs.org/download/release/${_NODE_VERSION}/node-${_NODE_VERSION}-headers.tar.gz"

"node-${_NODE_VERSION}/include/node"

"${_CACHE_DIR}/node/${_NODE_VERSION}"

)

endif()

# Generate the library

set(_TARGET "${NAME}.abi-${_ABI}")

add_library(${_TARGET} SHARED "${_CACHE_DIR}/empty.cpp")

list(APPEND _TARGETS "${_TARGET}")

# C identifiers can only contain certain characters (e.g. no dashes)

string(REGEX REPLACE "[^a-z0-9]+" "_" NAME_IDENTIFIER "${NAME}")

set_target_properties(${_TARGET} PROPERTIES

OUTPUT_NAME "${_TARGET}"

SOURCES "" # Removes the fake empty.cpp again

PREFIX ""

SUFFIX ".node"

MACOSX_RPATH ON

C_VISIBILITY_PRESET hidden

CXX_VISIBILITY_PRESET hidden

POSITION_INDEPENDENT_CODE TRUE

)

target_compile_definitions(${_TARGET} PRIVATE

"MODULE_NAME=${NAME_IDENTIFIER}"

"BUILDING_NODE_EXTENSION"

"_LARGEFILE_SOURCE"

"_FILE_OFFSET_BITS=64"

)

target_include_directories(${_TARGET} SYSTEM PRIVATE

"${_CACHE_DIR}/node/${_NODE_VERSION}"

)

if(_NAN_VERSION)

# Nan requires C++11. Use a compile option to allow interfaces to override this with a later version.

target_compile_options(${_TARGET} PRIVATE -std=c++11)

target_include_directories(${_TARGET} SYSTEM PRIVATE

"${_CACHE_DIR}/nan/${_NAN_VERSION}"

)

endif()

target_link_libraries(${_TARGET} PRIVATE ${NAME})

if(APPLE)

# Ensures that linked symbols are loaded when the module is loaded instead of causing

# unresolved symbol errors later during runtime.

set_target_properties(${_TARGET} PROPERTIES

LINK_FLAGS "-undefined dynamic_lookup -bind_at_load"

)

target_compile_definitions(${_TARGET} PRIVATE

"_DARWIN_USE_64_BIT_INODE=1"

)

else()

# Ensures that linked symbols are loaded when the module is loaded instead of causing

# unresolved symbol errors later during runtime.

set_target_properties(${_TARGET} PROPERTIES

LINK_FLAGS "-z now"

)

endif()

# Copy the file to the installation directory.

string(REPLACE "{node_abi}" "node-v${_ABI}" _OUTPUT_PATH "${_INSTALL_PATH}")

get_filename_component(_OUTPUT_PATH "${_OUTPUT_PATH}" ABSOLUTE "${CMAKE_CURRENT_SOURCE_PATH}")

add_custom_command(

TARGET ${_TARGET}

POST_BUILD

COMMAND ${CMAKE_COMMAND} -E copy "$<TARGET_FILE:${_TARGET}>" "${_OUTPUT_PATH}"

)

endforeach()

# Add a target that builds all Node ABIs.

add_custom_target("${NAME}.all")

add_dependencies("${NAME}.all" ${_TARGETS})

# Add a variable that allows users to iterate over all of the generated/dependendent targets.

set("${NAME}::abis" "${_ABIS}" PARENT_SCOPE)

set("${NAME}::targets" "${_TARGETS}" PARENT_SCOPE)

endfunction()