CapnProtoMacros.cmake (5121B)
1 # CAPNP_GENERATE_CPP =========================================================== 2 # 3 # Example usage: 4 # find_package(CapnProto) 5 # capnp_generate_cpp(CAPNP_SRCS CAPNP_HDRS schema.capnp) 6 # add_executable(foo main.cpp ${CAPNP_SRCS}) 7 # target_link_libraries(foo PRIVATE CapnProto::capnp-rpc) 8 # target_include_directories(foo PRIVATE ${CMAKE_CURRENT_BINARY_DIR}) 9 # 10 # If you are not using the RPC features you can use 'CapnProto::capnp' in the 11 # target_link_libraries call 12 # 13 # Configuration variables (optional): 14 # CAPNPC_OUTPUT_DIR 15 # Directory to place compiled schema sources (default: CMAKE_CURRENT_BINARY_DIR). 16 # CAPNPC_IMPORT_DIRS 17 # List of additional include directories for the schema compiler. 18 # (CAPNPC_SRC_PREFIX and CAPNP_INCLUDE_DIRECTORY are always included.) 19 # CAPNPC_SRC_PREFIX 20 # Schema file source prefix (default: CMAKE_CURRENT_SOURCE_DIR). 21 # CAPNPC_FLAGS 22 # Additional flags to pass to the schema compiler. 23 # 24 # TODO: convert to cmake_parse_arguments 25 26 function(CAPNP_GENERATE_CPP SOURCES HEADERS) 27 if(NOT ARGN) 28 message(SEND_ERROR "CAPNP_GENERATE_CPP() called without any source files.") 29 endif() 30 set(tool_depends ${EMPTY_STRING}) 31 #Use cmake targets available 32 if(TARGET capnp_tool) 33 if(NOT CAPNP_EXECUTABLE) 34 set(CAPNP_EXECUTABLE $<TARGET_FILE:capnp_tool>) 35 endif() 36 if(NOT CAPNPC_CXX_EXECUTABLE) 37 get_target_property(CAPNPC_CXX_EXECUTABLE capnpc_cpp CAPNPC_CXX_EXECUTABLE) 38 endif() 39 if(NOT CAPNP_INCLUDE_DIRECTORY) 40 get_target_property(CAPNP_INCLUDE_DIRECTORY capnp_tool CAPNP_INCLUDE_DIRECTORY) 41 endif() 42 list(APPEND tool_depends capnp_tool capnpc_cpp) 43 endif() 44 if(NOT CAPNP_EXECUTABLE) 45 message(SEND_ERROR "Could not locate capnp executable (CAPNP_EXECUTABLE).") 46 endif() 47 if(NOT CAPNPC_CXX_EXECUTABLE) 48 message(SEND_ERROR "Could not locate capnpc-c++ executable (CAPNPC_CXX_EXECUTABLE).") 49 endif() 50 if(NOT CAPNP_INCLUDE_DIRECTORY) 51 message(SEND_ERROR "Could not locate capnp header files (CAPNP_INCLUDE_DIRECTORY).") 52 endif() 53 54 if(DEFINED CAPNPC_OUTPUT_DIR) 55 # Prepend a ':' to get the format for the '-o' flag right 56 set(output_dir ":${CAPNPC_OUTPUT_DIR}") 57 else() 58 set(output_dir ":.") 59 endif() 60 61 if(NOT DEFINED CAPNPC_SRC_PREFIX) 62 set(CAPNPC_SRC_PREFIX "${CMAKE_CURRENT_SOURCE_DIR}") 63 endif() 64 get_filename_component(CAPNPC_SRC_PREFIX "${CAPNPC_SRC_PREFIX}" ABSOLUTE) 65 66 # Default compiler includes. Note that in capnp's own test usage of capnp_generate_cpp(), these 67 # two variables will end up evaluating to the same directory. However, it's difficult to 68 # deduplicate them because if CAPNP_INCLUDE_DIRECTORY came from the capnp_tool target property, 69 # then it must be a generator expression in order to handle usages in both the build tree and the 70 # install tree. This vastly overcomplicates duplication detection, so the duplication doesn't seem 71 # worth fixing. 72 set(include_path -I "${CAPNPC_SRC_PREFIX}" -I "${CAPNP_INCLUDE_DIRECTORY}") 73 74 if(DEFINED CAPNPC_IMPORT_DIRS) 75 # Append each directory as a series of '-I' flags in ${include_path} 76 foreach(directory ${CAPNPC_IMPORT_DIRS}) 77 get_filename_component(absolute_path "${directory}" ABSOLUTE) 78 list(APPEND include_path -I "${absolute_path}") 79 endforeach() 80 endif() 81 82 set(${SOURCES}) 83 set(${HEADERS}) 84 foreach(schema_file ${ARGN}) 85 get_filename_component(file_path "${schema_file}" ABSOLUTE) 86 get_filename_component(file_dir "${file_path}" PATH) 87 if(NOT EXISTS "${file_path}") 88 message(FATAL_ERROR "Cap'n Proto schema file '${file_path}' does not exist!") 89 endif() 90 91 # Figure out where the output files will go 92 if (NOT DEFINED CAPNPC_OUTPUT_DIR) 93 set(CAPNPC_OUTPUT_DIR "${CMAKE_CURRENT_BINARY_DIR}/") 94 endif() 95 # Output files are placed in CAPNPC_OUTPUT_DIR, at a location as if they were 96 # relative to CAPNPC_SRC_PREFIX. 97 string(LENGTH "${CAPNPC_SRC_PREFIX}" prefix_len) 98 string(SUBSTRING "${file_path}" 0 ${prefix_len} output_prefix) 99 if(NOT "${CAPNPC_SRC_PREFIX}" STREQUAL "${output_prefix}") 100 message(SEND_ERROR "Could not determine output path for '${schema_file}' ('${file_path}') with source prefix '${CAPNPC_SRC_PREFIX}' into '${CAPNPC_OUTPUT_DIR}'.") 101 endif() 102 103 string(SUBSTRING "${file_path}" ${prefix_len} -1 output_path) 104 set(output_base "${CAPNPC_OUTPUT_DIR}${output_path}") 105 106 add_custom_command( 107 OUTPUT "${output_base}.c++" "${output_base}.h" 108 COMMAND "${CAPNP_EXECUTABLE}" 109 ARGS compile 110 -o ${CAPNPC_CXX_EXECUTABLE}${output_dir} 111 --src-prefix ${CAPNPC_SRC_PREFIX} 112 ${include_path} 113 ${CAPNPC_FLAGS} 114 ${file_path} 115 DEPENDS "${schema_file}" ${tool_depends} 116 COMMENT "Compiling Cap'n Proto schema ${schema_file}" 117 VERBATIM 118 ) 119 120 list(APPEND ${SOURCES} "${output_base}.c++") 121 list(APPEND ${HEADERS} "${output_base}.h") 122 endforeach() 123 124 set_source_files_properties(${${SOURCES}} ${${HEADERS}} PROPERTIES GENERATED TRUE) 125 set(${SOURCES} ${${SOURCES}} PARENT_SCOPE) 126 set(${HEADERS} ${${HEADERS}} PARENT_SCOPE) 127 endfunction()