Files
spark/cmake/ProtobufGenerateCppConfig.cmake
John Colvin 4f404eec24 build: Clean up protobuf cmake scripts
Make them more flexible, reusable. This is a precursor to porting over
python md provider code from another branch.
2025-06-13 20:50:28 +00:00

62 lines
2.5 KiB
CMake

include_guard(GLOBAL)
function(protobuf_generate_cpp_config)
set(_options)
set(_one_value_args
PROTO_SOURCES_HEADER
PROTO_DEFAULTS_HEADER
)
set(_multi_value_args
PROTO_SOURCES
PROTO_DEFAULTS
)
cmake_parse_arguments(_ARGS "${_options}" "${_one_value_args}" "${_multi_value_args}" ${ARGN})
# Configure the 'config_proto_files' header. It provides an array of strings populated with the
# files in PROTO_SOURCES. At runtime, we use this array to generate a special 'config' proto
# message with fields for each message defined in said files. A global instance of this 'config'
# proto is then constructed, and populated with [compile-time] defaults, and [runtime] overrides
# (i.e., in spark.conf). Calls to `bts::config::get<T>()` retrieve the value from the field
# associated with type `T` in this global instance.
message(STATUS "PROTO_SOURCES: ${_ARGS_PROTO_SOURCES}")
message(STATUS "PROTO_SOURCES_HEADER: ${_ARGS_PROTO_SOURCES_HEADER}")
message(STATUS "PROTO_DEFAULTS_HEADER: ${_ARGS_PROTO_DEFAULTS_HEADER}")
if (_ARGS_PROTO_SOURCES_HEADER)
set(PROTO_SOURCES)
set(PROTO_SOURCES_CXX_ARRAY_ITEMS "")
foreach(_proto_path ${_ARGS_PROTO_SOURCES})
list(APPEND PROTO_SOURCES ${_proto_path})
string(APPEND PROTO_SOURCES_CXX_ARRAY_ITEMS "\"${_proto_path}\",\n")
endforeach()
list(LENGTH PROTO_SOURCES PROTO_SOURCES_LENGTH)
message(STATUS "CONFIGURING PROTO_SOURCES_HEADER): ${_ARGS_PROTO_SOURCES_HEADER}")
configure_file(${CMAKE_SOURCE_DIR}/cmake/config_proto_files.h.in ${_ARGS_PROTO_SOURCES_HEADER})
endif()
# Generate static defaults. Ideally, this would be a single string, but we use an array because
# the compiler complains if the string is longer than 65k.
set(_cfg_defaults_str "inline const char * config_static_defaults[] = { ")
foreach(_cfg_file_path ${_ARGS_PROTO_DEFAULTS})
file(READ ${_cfg_file_path} _cfg_file_content)
string(REPLACE "\"" "\\\"" _cfg_file_content_escaped ${_cfg_file_content})
string(REPLACE "\n" ";" _cfg_lines ${_cfg_file_content_escaped})
foreach(_line ${_cfg_lines})
string(APPEND _cfg_defaults_str "\n \"${_line}\",")
endforeach(_line)
endforeach(_cfg_file_path)
string(APPEND _cfg_defaults_str "};")
set(_old_cfg_defaults_str "")
if(EXISTS ${_ARGS_PROTO_DEFAULTS_HEADER})
file(READ ${_ARGS_PROTO_DEFAULTS_HEADER} _old_cfg_defaults_str)
endif()
if(NOT _cfg_defaults_str STREQUAL _old_cfg_defaults_str)
file(WRITE "${_ARGS_PROTO_DEFAULTS_HEADER}" "${_cfg_defaults_str}")
endif()
endfunction()