packaging/cmake/Modules/NetdataProtobuf.cmake
# Macros and functions for handling of Protobuf
#
# Copyright (c) 2024 Netdata Inc.
# SPDX-License-Identifier: GPL-3.0-or-later
# Prepare a vendored copy of Protobuf for use with Netdata.
function(netdata_bundle_protobuf)
include(FetchContent)
include(NetdataFetchContentExtra)
set(PROTOBUF_TAG f0dc78d7e6e331b8c6bb2d5283e06aa26883ca7c) # v21.12
set(NEED_ABSL False)
if(CMAKE_CXX_STANDARD GREATER_EQUAL 14)
set(PROTOBUF_TAG 4a2aef570deb2bfb8927426558701e8bfc26f2a4) # v25.3
set(NEED_ABSL True)
set(ABSL_TAG 2f9e432cce407ce0ae50676696666f33a77d42ac) # 20240116.1
endif()
set(FETCHCONTENT_TRY_FIND_PACKAGE_MODE NEVER)
string(REPLACE "-fsanitize=address" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
string(REPLACE "-fsanitize=address" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
# ignore debhelper
set(FETCHCONTENT_FULLY_DISCONNECTED Off)
if(NEED_ABSL)
set(ABSL_PROPAGATE_CXX_STD On)
set(ABSL_ENABLE_INSTALL Off)
message(STATUS "Preparing bundled Abseil (required by bundled Protobuf)")
FetchContent_Declare(absl
GIT_REPOSITORY https://github.com/abseil/abseil-cpp
GIT_TAG ${ABSL_TAG}
)
FetchContent_MakeAvailable_NoInstall(absl)
message(STATUS "Finished preparing bundled Abseil")
endif()
set(protobuf_INSTALL Off)
set(protobuf_BUILD_LIBPROTOC Off)
set(protobuf_BUILD_TESTS Off)
set(protobuf_BUILD_SHARED_LIBS Off)
message(STATUS "Preparing bundled Protobuf")
FetchContent_Declare(protobuf
GIT_REPOSITORY https://github.com/protocolbuffers/protobuf.git
GIT_TAG ${PROTOBUF_TAG}
)
FetchContent_MakeAvailable_NoInstall(protobuf)
message(STATUS "Finished preparing bundled Protobuf.")
set(BUNDLED_PROTOBUF True PARENT_SCOPE)
endfunction()
# Handle detection of Protobuf
macro(netdata_detect_protobuf)
if(COMPILED_FOR_WINDOWS)
set(PROTOBUF_PROTOC_EXECUTABLE "$ENV{PROTOBUF_PROTOC_EXECUTABLE}")
if(NOT PROTOBUF_PROTOC_EXECUTABLE)
set(PROTOBUF_PROTOC_EXECUTABLE "/bin/protoc")
endif()
set(PROTOBUF_CFLAGS_OTHER "")
set(PROTOBUF_INCLUDE_DIRS "")
set(PROTOBUF_LIBRARIES "-lprotobuf")
set(ENABLE_PROTOBUF True)
set(HAVE_PROTOBUF True)
else()
if(NOT ENABLE_BUNDLED_PROTOBUF)
if (NOT BUILD_SHARED_LIBS)
set(Protobuf_USE_STATIC_LIBS On)
endif()
# The FindProtobuf CMake module shipped by upstream CMake is
# broken for Protobuf version 22.0 and newer because it does
# not correctly pull in the new Abseil dependencies. Protobuf
# itself sometimes ships a CMake Package Configuration module
# that _does_ work correctly, so use that in preference to the
# Find module shipped with CMake.
#
# The code below works by first attempting to use find_package
# in config mode, and then checking for the existence of the
# target we actually use that gets defined by the protobuf
# CMake Package Configuration Module to determine if that
# worked. A bit of extra logic is required in the case of the
# config mode working, because some systems ship compatibility
# logic for the old FindProtobuf module while others do not.
#
# Upstream bug reference: https://gitlab.kitware.com/cmake/cmake/-/issues/24321
find_package(Protobuf CONFIG)
if(NOT TARGET protobuf::libprotobuf)
message(STATUS "Could not find Protobuf using Config mode, falling back to Module mode")
find_package(Protobuf REQUIRED)
endif()
endif()
if(TARGET protobuf::libprotobuf)
if(NOT Protobuf_PROTOC_EXECUTABLE AND TARGET protobuf::protoc)
set(Protobuf_PROTOC_EXECUTABLE protobuf::protoc)
endif()
# It is technically possible that this may still not
# be set by this point, so we need to check it and
# fail noisily if it isn't because the build won't
# work without it.
if(NOT Protobuf_PROTOC_EXECUTABLE)
message(FATAL_ERROR "Could not determine the location of the protobuf compiler for the detected version of protobuf.")
endif()
set(PROTOBUF_PROTOC_EXECUTABLE ${Protobuf_PROTOC_EXECUTABLE})
set(PROTOBUF_LIBRARIES protobuf::libprotobuf)
endif()
set(ENABLE_PROTOBUF True)
set(HAVE_PROTOBUF True)
endif()
endmacro()
# Helper function to compile protocol definitions into C++ code.
function(netdata_protoc_generate_cpp INC_DIR OUT_DIR SRCS HDRS)
if(NOT ARGN)
message(SEND_ERROR "Error: protoc_generate_cpp() called without any proto files")
return()
endif()
set(${INC_DIR})
set(${OUT_DIR})
set(${SRCS})
set(${HDRS})
foreach(FIL ${ARGN})
get_filename_component(ABS_FIL ${FIL} ABSOLUTE)
get_filename_component(DIR ${ABS_FIL} DIRECTORY)
get_filename_component(FIL_WE ${FIL} NAME_WE)
set(GENERATED_PB_CC "${DIR}/${FIL_WE}.pb.cc")
list(APPEND ${SRCS} ${GENERATED_PB_CC})
set(GENERATED_PB_H "${DIR}/${FIL_WE}.pb.h")
list(APPEND ${HDRS} ${GENERATED_PB_H})
list(APPEND _PROTOC_INCLUDE_DIRS ${INC_DIR})
if(ENABLE_BUNDLED_PROTOBUF)
list(APPEND _PROTOC_INCLUDE_DIRS ${CMAKE_BINARY_DIR}/_deps/protobuf-src/src/)
endif()
add_custom_command(OUTPUT ${GENERATED_PB_CC} ${GENERATED_PB_H}
COMMAND ${PROTOBUF_PROTOC_EXECUTABLE}
ARGS "-I$<JOIN:${_PROTOC_INCLUDE_DIRS},;-I>" --cpp_out=${OUT_DIR} ${ABS_FIL}
DEPENDS ${ABS_FIL} ${PROTOBUF_PROTOC_EXECUTABLE}
COMMENT "Running C++ protocol buffer compiler on ${FIL}"
COMMAND_EXPAND_LISTS)
endforeach()
set_source_files_properties(${${SRCS}} ${${HDRS}} PROPERTIES GENERATED TRUE)
set_source_files_properties(${${SRCS}} ${${HDRS}} PROPERTIES COMPILE_OPTIONS -Wno-deprecated-declarations)
set(${SRCS} ${${SRCS}} PARENT_SCOPE)
set(${HDRS} ${${HDRS}} PARENT_SCOPE)
endfunction()
# Add protobuf to a specified target.
function(netdata_add_protobuf _target)
target_compile_options(${_target} PRIVATE ${PROTOBUF_CFLAGS_OTHER})
target_include_directories(${_target} PRIVATE ${PROTOBUF_INCLUDE_DIRS})
target_link_libraries(${_target} PRIVATE ${PROTOBUF_LIBRARIES})
endfunction()