# Copyright 2015 Google Inc. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not use this
# file except in compliance with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed under
# the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific language
# governing permissions and limitations under the License.
# General function to create FlatBuffer build rules for the given list of schemas.
#
# flatbuffers_schemas: A list of flatbuffer schema files to process.
#
# schema_include_dirs: A list of schema file include directories, which will be passed
# to flatc via the -I parameter.
#
# custom_target_name: The generated files will be added as dependencies for a new custom
# target with this name. You should add that target as a dependency for your main target
# to ensure these files are built. You can also retrieve various properties from this
# target, such as GENERATED_INCLUDES_DIR, BINARY_SCHEMAS_DIR, and COPY_TEXT_SCHEMAS_DIR.
#
# additional_dependencies: A list of additional dependencies that you'd like all
# generated files to depend on. Pass in a blank string if you have none.
#
# generated_includes_dir: Where to generate the C++ header files for these schemas. The
# generated includes directory will automatically be added to CMake's include
# directories, and will be where generated header files are placed. This parameter is
# optional; pass in empty string if you don't want to generate include files for these
# schemas.
#
# binary_schemas_dir: If you specify an optional binary schema directory, binary schemas
# will be generated for these schemas as well, and placed into the given directory.
#
# copy_text_schemas_dir: If you want all text schemas (including schemas from all schema
# include directories) copied into a directory (for example, if you need them within
# your project to build JSON files), you can specify that folder here. All text schemas
# will be copied to that folder.
#
# IMPORTANT: Make sure you quote all list arguments you pass to this function! Otherwise
# CMake will only pass in the first element. Example: build_flatbuffers("${fb_files}"
# "${include_dirs}" target_name ...)
function(
build_flatbuffers
flatbuffers_schemas
schema_include_dirs
custom_target_name
additional_dependencies
generated_includes_dir
binary_schemas_dir
copy_text_schemas_dir)
# Test if including from FindFlatBuffers
if(FLATBUFFERS_FLATC_EXECUTABLE)
set(FLATC_TARGET "")
set(FLATC ${FLATBUFFERS_FLATC_EXECUTABLE})
else()
set(FLATC_TARGET flatbuffers::flatc)
set(FLATC flatc)
endif()
set(FLATC_SCHEMA_ARGS --gen-mutable)
if(FLATBUFFERS_FLATC_SCHEMA_EXTRA_ARGS)
set(FLATC_SCHEMA_ARGS ${FLATBUFFERS_FLATC_SCHEMA_EXTRA_ARGS} ${FLATC_SCHEMA_ARGS})
endif()
set(working_dir "${CMAKE_CURRENT_SOURCE_DIR}")
set(schema_glob "*.fbs")
# Generate the include files parameters.
set(include_params "")
set(all_generated_files "")
foreach(include_dir ${schema_include_dirs})
set(include_params -I ${include_dir} ${include_params})
if(NOT ${copy_text_schemas_dir} STREQUAL "")
# Copy text schemas from dependent folders.
file(GLOB_RECURSE dependent_schemas ${include_dir}/${schema_glob})
foreach(dependent_schema ${dependent_schemas})
file(COPY ${dependent_schema} DESTINATION ${copy_text_schemas_dir})
endforeach()
endif()
endforeach()
foreach(schema ${flatbuffers_schemas})
get_filename_component(filename ${schema} NAME_WE)
# For each schema, do the things we requested.
if(NOT ${generated_includes_dir} STREQUAL "")
set(generated_include ${generated_includes_dir}/${filename}_generated.h)
add_custom_command(
OUTPUT ${generated_include}
COMMAND ${FLATC} ${FLATC_SCHEMA_ARGS} -o ${generated_includes_dir}
${include_params} -c ${schema}
DEPENDS ${FLATC_TARGET} ${schema} ${additional_dependencies}
WORKING_DIRECTORY "${working_dir}")
list(APPEND all_generated_files ${generated_include})
endif()
if(NOT ${binary_schemas_dir} STREQUAL "")
set(binary_schema ${binary_schemas_dir}/${filename}.bfbs)
add_custom_command(
OUTPUT ${binary_schema}
COMMAND ${FLATC} -b --schema -o ${binary_schemas_dir} ${include_params}
${schema}
DEPENDS ${FLATC_TARGET} ${schema} ${additional_dependencies}
WORKING_DIRECTORY "${working_dir}")
list(APPEND all_generated_files ${binary_schema})
endif()
if(NOT ${copy_text_schemas_dir} STREQUAL "")
file(COPY ${schema} DESTINATION ${copy_text_schemas_dir})
endif()
endforeach()
# Create a custom target that depends on all the generated files. This is the target
# that you can depend on to trigger all these to be built.
add_custom_target(${custom_target_name} DEPENDS ${all_generated_files}
${additional_dependencies})
# Register the include directory we are using.
if(NOT ${generated_includes_dir} STREQUAL "")
include_directories(${generated_includes_dir})
set_property(TARGET ${custom_target_name} PROPERTY GENERATED_INCLUDES_DIR
${generated_includes_dir})
endif()
# Register the binary schemas dir we are using.
if(NOT ${binary_schemas_dir} STREQUAL "")
set_property(TARGET ${custom_target_name} PROPERTY BINARY_SCHEMAS_DIR
${binary_schemas_dir})
endif()
# Register the text schema copy dir we are using.
if(NOT ${copy_text_schemas_dir} STREQUAL "")
set_property(TARGET ${custom_target_name} PROPERTY COPY_TEXT_SCHEMAS_DIR
${copy_text_schemas_dir})
endif()
endfunction()