# Distributed under the OSI-approved BSD 3-Clause License. See accompanying # file Copyright.txt or https://cmake.org/licensing for details. #[=======================================================================[.rst: FindFLEX -------- Find Fast Lexical Analyzer (Flex) executable and provides a macro to generate custom build rules The module defines the following variables: :: FLEX_FOUND - True is flex executable is found FLEX_EXECUTABLE - the path to the flex executable FLEX_VERSION - the version of flex FLEX_LIBRARIES - The flex libraries FLEX_INCLUDE_DIRS - The path to the flex headers The minimum required version of flex can be specified using the standard syntax, e.g. :command:`find_package(FLEX 2.5.13)` If flex is found on the system, the module provides the macro: :: FLEX_TARGET(Name FlexInput FlexOutput [COMPILE_FLAGS ] [DEFINES_FILE ] ) which creates a custom command to generate the ``FlexOutput`` file from the ``FlexInput`` file. If ``COMPILE_FLAGS`` option is specified, the next parameter is added to the flex command line. If flex is configured to output a header file, the ``DEFINES_FILE`` option may be used to specify its name. Name is an alias used to get details of this custom command. Indeed the macro defines the following variables: :: FLEX_${Name}_DEFINED - true is the macro ran successfully FLEX_${Name}_OUTPUTS - the source file generated by the custom rule, an alias for FlexOutput FLEX_${Name}_INPUT - the flex source file, an alias for ${FlexInput} FLEX_${Name}_OUTPUT_HEADER - the header flex output, if any. Flex scanners often use tokens defined by Bison: the code generated by Flex depends of the header generated by Bison. This module also defines a macro: :: ADD_FLEX_BISON_DEPENDENCY(FlexTarget BisonTarget) which adds the required dependency between a scanner and a parser where ``FlexTarget`` and ``BisonTarget`` are the first parameters of respectively ``FLEX_TARGET`` and ``BISON_TARGET`` macros. :: ==================================================================== Example: :: find_package(BISON) find_package(FLEX) :: BISON_TARGET(MyParser parser.y ${CMAKE_CURRENT_BINARY_DIR}/parser.cpp) FLEX_TARGET(MyScanner lexer.l ${CMAKE_CURRENT_BINARY_DIR}/lexer.cpp) ADD_FLEX_BISON_DEPENDENCY(MyScanner MyParser) :: include_directories(${CMAKE_CURRENT_BINARY_DIR}) add_executable(Foo Foo.cc ${BISON_MyParser_OUTPUTS} ${FLEX_MyScanner_OUTPUTS} ) target_link_libraries(Foo ${FLEX_LIBRARIES}) ==================================================================== #]=======================================================================] find_program(FLEX_EXECUTABLE NAMES flex win_flex DOC "path to the flex executable") mark_as_advanced(FLEX_EXECUTABLE) find_library(FL_LIBRARY NAMES fl DOC "Path to the fl library") find_path(FLEX_INCLUDE_DIR FlexLexer.h DOC "Path to the flex headers") mark_as_advanced(FL_LIBRARY FLEX_INCLUDE_DIR) set(FLEX_INCLUDE_DIRS ${FLEX_INCLUDE_DIR}) set(FLEX_LIBRARIES ${FL_LIBRARY}) if(FLEX_EXECUTABLE) execute_process(COMMAND ${FLEX_EXECUTABLE} --version OUTPUT_VARIABLE FLEX_version_output ERROR_VARIABLE FLEX_version_error RESULT_VARIABLE FLEX_version_result OUTPUT_STRIP_TRAILING_WHITESPACE) if(NOT ${FLEX_version_result} EQUAL 0) if(FLEX_FIND_REQUIRED) message(SEND_ERROR "Command \"${FLEX_EXECUTABLE} --version\" failed with output:\n${FLEX_version_output}\n${FLEX_version_error}") else() message("Command \"${FLEX_EXECUTABLE} --version\" failed with output:\n${FLEX_version_output}\n${FLEX_version_error}\nFLEX_VERSION will not be available") endif() else() # older versions of flex printed "/full/path/to/executable version X.Y" # newer versions use "basename(executable) X.Y" get_filename_component(FLEX_EXE_NAME_WE "${FLEX_EXECUTABLE}" NAME_WE) get_filename_component(FLEX_EXE_EXT "${FLEX_EXECUTABLE}" EXT) string(REGEX REPLACE "^.*${FLEX_EXE_NAME_WE}(${FLEX_EXE_EXT})?\"? (version )?([0-9]+[^ ]*)( .*)?$" "\\3" FLEX_VERSION "${FLEX_version_output}") unset(FLEX_EXE_EXT) unset(FLEX_EXE_NAME_WE) endif() #============================================================ # FLEX_TARGET (public macro) #============================================================ # macro(FLEX_TARGET Name Input Output) set(FLEX_TARGET_PARAM_OPTIONS) set(FLEX_TARGET_PARAM_ONE_VALUE_KEYWORDS COMPILE_FLAGS DEFINES_FILE ) set(FLEX_TARGET_PARAM_MULTI_VALUE_KEYWORDS) cmake_parse_arguments( FLEX_TARGET_ARG "${FLEX_TARGET_PARAM_OPTIONS}" "${FLEX_TARGET_PARAM_ONE_VALUE_KEYWORDS}" "${FLEX_TARGET_MULTI_VALUE_KEYWORDS}" ${ARGN} ) set(FLEX_TARGET_usage "FLEX_TARGET( [COMPILE_FLAGS ] [DEFINES_FILE ]") if(NOT "${FLEX_TARGET_ARG_UNPARSED_ARGUMENTS}" STREQUAL "") message(SEND_ERROR ${FLEX_TARGET_usage}) else() cmake_policy(GET CMP0098 _flex_CMP0098 PARENT_SCOPE # undocumented, do not use outside of CMake ) set(_flex_INPUT "${Input}") if("x${_flex_CMP0098}x" STREQUAL "xNEWx") set(_flex_WORKING_DIR "${CMAKE_CURRENT_BINARY_DIR}") if(NOT IS_ABSOLUTE "${_flex_INPUT}") set(_flex_INPUT "${CMAKE_CURRENT_SOURCE_DIR}/${_flex_INPUT}") endif() else() set(_flex_WORKING_DIR "${CMAKE_CURRENT_SOURCE_DIR}") endif() unset(_flex_CMP0098) set(_flex_OUTPUT "${Output}") if(NOT IS_ABSOLUTE ${_flex_OUTPUT}) set(_flex_OUTPUT "${_flex_WORKING_DIR}/${_flex_OUTPUT}") endif() set(_flex_TARGET_OUTPUTS "${_flex_OUTPUT}") set(_flex_EXE_OPTS "") if(NOT "${FLEX_TARGET_ARG_COMPILE_FLAGS}" STREQUAL "") set(_flex_EXE_OPTS "${FLEX_TARGET_ARG_COMPILE_FLAGS}") separate_arguments(_flex_EXE_OPTS) endif() set(_flex_OUTPUT_HEADER "") if(NOT "${FLEX_TARGET_ARG_DEFINES_FILE}" STREQUAL "") set(_flex_OUTPUT_HEADER "${FLEX_TARGET_ARG_DEFINES_FILE}") if(IS_ABSOLUTE "${_flex_OUTPUT_HEADER}") set(_flex_OUTPUT_HEADER_ABS "${_flex_OUTPUT_HEADER}") else() set(_flex_OUTPUT_HEADER_ABS "${_flex_WORKING_DIR}/${_flex_OUTPUT_HEADER}") endif() list(APPEND _flex_TARGET_OUTPUTS "${_flex_OUTPUT_HEADER_ABS}") list(APPEND _flex_EXE_OPTS --header-file=${_flex_OUTPUT_HEADER_ABS}) endif() get_filename_component(_flex_EXE_NAME_WE "${FLEX_EXECUTABLE}" NAME_WE) add_custom_command(OUTPUT ${_flex_TARGET_OUTPUTS} COMMAND ${FLEX_EXECUTABLE} ${_flex_EXE_OPTS} -o${_flex_OUTPUT} ${_flex_INPUT} VERBATIM DEPENDS ${_flex_INPUT} COMMENT "[FLEX][${Name}] Building scanner with ${_flex_EXE_NAME_WE} ${FLEX_VERSION}" WORKING_DIRECTORY ${_flex_WORKING_DIR}) set(FLEX_${Name}_DEFINED TRUE) set(FLEX_${Name}_OUTPUTS ${_flex_TARGET_OUTPUTS}) set(FLEX_${Name}_INPUT ${_flex_INPUT}) set(FLEX_${Name}_COMPILE_FLAGS ${_flex_EXE_OPTS}) set(FLEX_${Name}_OUTPUT_HEADER ${_flex_OUTPUT_HEADER}) unset(_flex_EXE_NAME_WE) unset(_flex_EXE_OPTS) unset(_flex_INPUT) unset(_flex_OUTPUT) unset(_flex_OUTPUT_HEADER) unset(_flex_OUTPUT_HEADER_ABS) unset(_flex_TARGET_OUTPUTS) unset(_flex_WORKING_DIR) endif() endmacro() #============================================================ #============================================================ # ADD_FLEX_BISON_DEPENDENCY (public macro) #============================================================ # macro(ADD_FLEX_BISON_DEPENDENCY FlexTarget BisonTarget) if(NOT FLEX_${FlexTarget}_OUTPUTS) message(SEND_ERROR "Flex target `${FlexTarget}' does not exist.") endif() if(NOT BISON_${BisonTarget}_OUTPUT_HEADER) message(SEND_ERROR "Bison target `${BisonTarget}' does not exist.") endif() set_source_files_properties(${FLEX_${FlexTarget}_OUTPUTS} PROPERTIES OBJECT_DEPENDS ${BISON_${BisonTarget}_OUTPUT_HEADER}) endmacro() #============================================================ endif() include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake) FIND_PACKAGE_HANDLE_STANDARD_ARGS(FLEX REQUIRED_VARS FLEX_EXECUTABLE VERSION_VAR FLEX_VERSION)