FindProtobufC.cmake

# - Find protobuf-c
# Find protobuf c implementation libraries, includes and the protoc-c compiler
# FindProtobufC was loosely based on FindProtobuf that is shipped with cmake
#
# Module defines:
#   PROTOBUFC_FOUND        - library, includes and compiler where found
#   PROTOBUFC_INCLUDE_DIRS - include directories
#   PROTOBUFC_LIBRARIES    - protobuf-c libraries
#   PROTOBUFC_EXECUTEABLE  - protobuf-c compiler
#
# Environment variables:
#   PROTOBUFC_ROOTDIR      - optional - rootdir of protobuf-c installation
#
# Cache entries:
#   PROTOBUFC_LIBRARY      - detected protobuf-c library
#   PROTOBUF_INCLUDE_DIR   - detected protobuf-c include dir(s)
#   PROTOBUF_COMPILER      - detected protobuf-c compiler
#
####
#
#  ====================================================================
#  Example:
#
#   find_package(ProtobufC REQUIRED)
#   include_directories(${PROTOBUFC_INCLUDE_DIRS})
#   include_directories(${CMAKE_CURRENT_BINARY_DIR})
#   PROTOBUFC_GENERATE_C(PROTO_SOURCES PROTO_HEADERS protobuf.proto)
#   add_executable(bar bar.c ${PROTO_SRCn} ${PROTO_HDRS})
#   target_link_libraries(bar ${PROTOBUF_LIBRARIES})
#
# NOTE: You may need to link against pthreads, depending
#       on the platform.
#
# NOTE: The PROTOBUF_GENERATE_CPP macro & add_executable() or add_library()
#       calls only work properly within the same directory.
#
#  ====================================================================

#=============================================================================
# Copyright 2013 Thinstuff Technologies GmbH
# Copyright 2013 Bernhard Miklautz <bmiklautz@thinstuff.at>
#
# 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.
#=============================================================================

set(PROTBUFC_SOURCE_EXTENSION "pb-c.c")
set(PROTBUFC_HEADER_EXTENSION "pb-c.h")
function(PROTOBUFC_GENERATE_C SOURCES HEADERS)
	if(NOT ARGN)
		message(SEND_ERROR "Error: PROTOBUFC_GENERATE_C() called without any proto files")
 	 	return()
	endif(NOT ARGN)

 foreach(FIL ${ARGN})
    get_filename_component(ABS_FIL ${FIL} ABSOLUTE)
    get_filename_component(FIL_WE ${FIL} NAME_WE)
    get_filename_component(FIL_PATH ${ABS_FIL} PATH)

    list(APPEND ${SOURCES} "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.${PROTBUFC_SOURCE_EXTENSION}")
    list(APPEND ${HEADERS} "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.${PROTBUFC_HEADER_EXTENSION}")

    add_custom_command(
      OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.${PROTBUFC_SOURCE_EXTENSION}"
             "${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.${PROTBUFC_HEADER_EXTENSION}"
      COMMAND  ${PROTOBUFC_COMPILER}
      ARGS --c_out ${CMAKE_CURRENT_BINARY_DIR} -I ${CMAKE_CURRENT_SOURCE_DIR} -I ${FIL_PATH} ${ABS_FIL}
      DEPENDS ${ABS_FIL}
      COMMENT "Running protobuf-c compiler on ${FIL}"
      VERBATIM )
  endforeach()
  set_source_files_properties(${${SOURCES}} ${${HEADERS}} PROPERTIES GENERATED TRUE)
  set(${SOURCES} ${${SOURCES}} PARENT_SCOPE)
  set(${HEADERS} ${${HEADERS}} PARENT_SCOPE)
endfunction()

find_library(PROTOBUFC_LIBRARY
							NAMES "protobuf-c"
							PATHS "/usr" "/usr/local" "/opt" ENV PROTOBUFC_ROOTDIR
							PATH_SUFFIXES "lib")
mark_as_advanced(PROTOBUFC_LIBRARY)

find_path(PROTOBUFC_INCLUDE_DIR
							NAMES "google/protobuf-c/protobuf-c.h"
							PATHS "/usr" "/usr/local" "/opt" ENV PROTOBUFC_ROOTDIR
							PATH_SUFFIXES "include")
mark_as_advanced(PROTOBUFC_INCLUDE_DIR)

find_program(PROTOBUFC_COMPILER
							NAMES "protoc-c"
							PATHS "/usr" "/usr/local" "/opt" ENV PROTOBUFC_ROOTDIR
							PATH_SUFFIXES "bin")
mark_as_advanced(PROTOBUFC_COMPILER)

include(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(ProtobufC DEFAULT_MSG PROTOBUFC_LIBRARY PROTOBUFC_COMPILER PROTOBUFC_INCLUDE_DIR )

if (PROTOBUFC_FOUND)
	set(PROTOBUFC_LIBRARIES ${PROTOBUFC_LIBRARY})
	set(PROTOBUFC_INCLUDE_DIRS ${PROTOBUFC_INCLUDE_DIR})
	set(PROTOBUFC_EXECUTEABLE ${PROTOBUFC_COMPILER})
endif(PROTOBUFC_FOUND)