CMake/Modules/FindFLEX.cmake

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# - Find 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
#
# The minimum required version of flex can be specified using the
# standard syntax, e.g. 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 <string>])
# 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. 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 scanners oftenly 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 ${CMAKE_CURRENT_BIANRY_DIR}/lexer.cpp)
# ADD_FLEX_BISON_DEPENDENCY(MyScanner MyParser)
#
# include_directories(${CMAKE_CURRENT_BINARY_DIR})
# add_executable(Foo
# Foo.cc
# ${BISON_MyParser_OUTPUTS}
# ${FLEX_MyScanner_OUTPUTS}
# )
# ====================================================================
#=============================================================================
# Copyright 2009 Kitware, Inc.
# Copyright 2006 Tristan Carel
#
# Distributed under the OSI-approved BSD License (the "License");
# see accompanying file Copyright.txt for details.
#
# This software is distributed WITHOUT ANY WARRANTY; without even the
# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# See the License for more information.
#=============================================================================
# (To distribute this file outside of CMake, substitute the full
# License text for the above reference.)
FIND_PROGRAM(FLEX_EXECUTABLE flex DOC "path to the flex executable")
MARK_AS_ADVANCED(FLEX_EXECUTABLE)
FIND_LIBRARY(FL_LIBRARY NAMES fl
DOC "path to the fl library")
MARK_AS_ADVANCED(FL_LIBRARY)
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${FLEX_version_error}\nFLEX_VERSION will not be available")
ENDIF()
ELSE()
STRING(REGEX REPLACE "^flex (.*)$" "\\1"
FLEX_VERSION "${FLEX_version_output}")
ENDIF()
#============================================================
# FLEX_TARGET (public macro)
#============================================================
#
MACRO(FLEX_TARGET Name Input Output)
SET(FLEX_TARGET_usage "FLEX_TARGET(<Name> <Input> <Output> [COMPILE_FLAGS <string>]")
IF(${ARGC} GREATER 3)
IF(${ARGC} EQUAL 5)
IF("${ARGV3}" STREQUAL "COMPILE_FLAGS")
SET(FLEX_EXECUTABLE_opts "${ARGV4}")
SEPARATE_ARGUMENTS(FLEX_EXECUTABLE_opts)
ELSE()
MESSAGE(SEND_ERROR ${FLEX_TARGET_usage})
ENDIF()
ELSE()
MESSAGE(SEND_ERROR ${FLEX_TARGET_usage})
ENDIF()
ENDIF()
ADD_CUSTOM_COMMAND(OUTPUT ${Output}
COMMAND ${FLEX_EXECUTABLE}
ARGS ${FLEX_EXECUTABLE_opts} -o${Output} ${Input}
DEPENDS ${Input}
COMMENT "[FLEX][${Name}] Building scanner with flex ${FLEX_VERSION}"
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
SET(FLEX_${Name}_DEFINED TRUE)
SET(FLEX_${Name}_OUTPUTS ${Output})
SET(FLEX_${Name}_INPUT ${Input})
SET(FLEX_${Name}_COMPILE_FLAGS ${FLEX_EXECUTABLE_opts})
ENDMACRO(FLEX_TARGET)
#============================================================
#============================================================
# ADD_FLEX_BISON_DEPENDENCY (public macro)
#============================================================
#
MACRO(ADD_FLEX_BISON_DEPENDENCY FlexTarget BisonTarget)
IF(NOT FLEX_${FlexTarget}_OUTPUTS)
MESSAGE(SEND_ERROR "Flex target `${FlexTarget}' does not exists.")
ENDIF()
IF(NOT BISON_${BisonTarget}_OUTPUT_HEADER)
MESSAGE(SEND_ERROR "Bison target `${BisonTarget}' does not exists.")
ENDIF()
SET_SOURCE_FILES_PROPERTIES(${FLEX_${FlexTarget}_OUTPUTS}
PROPERTIES OBJECT_DEPENDS ${BISON_${BisonTarget}_OUTPUT_HEADER})
ENDMACRO(ADD_FLEX_BISON_DEPENDENCY)
#============================================================
ENDIF(FLEX_EXECUTABLE)
INCLUDE(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(FLEX REQUIRED_VARS FLEX_EXECUTABLE
VERSION_VAR FLEX_VERSION)
# FindFLEX.cmake ends here