lbrycrd/contrib/cmake/cmake/FindLibevent.cmake
2019-07-19 12:21:59 -06:00

97 lines
3.4 KiB
CMake

# - Try to find libevent
#.rst
# FindLibevent
# ------------
#
# Find Libevent include directories and libraries. Invoke as::
#
# find_package(Libevent
# [version] [EXACT] # Minimum or exact version
# [REQUIRED] # Fail if Libevent is not found
# [COMPONENT <C>...]) # Libraries to look for
#
# Valid components are one or more of:: libevent core extra pthreads openssl.
# Note that 'libevent' contains both core and extra. You must specify one of
# them for the other components.
#
# This module will define the following variables::
#
# LIBEVENT_FOUND - True if headers and requested libraries were found
# LIBEVENT_INCLUDE_DIRS - Libevent include directories
# LIBEVENT_LIBRARIES - Libevent libraries to be linked
# LIBEVENT_<C>_FOUND - Component <C> was found (<C> is uppercase)
# LIBEVENT_<C>_LIBRARY - Library to be linked for Libevent component <C>.
find_package(PkgConfig QUIET)
pkg_check_modules(PC_LIBEVENT QUIET libevent)
# Look for the Libevent 2.0 or 1.4 headers
find_path(LIBEVENT_INCLUDE_DIR
NAMES
event2/event-config.h
event-config.h
HINTS
${PC_LIBEVENT_INCLUDE_DIRS}
)
if(LIBEVENT_INCLUDE_DIR)
set(_version_regex "^#define[ \t]+_EVENT_VERSION[ \t]+\"([^\"]+)\".*")
if(EXISTS "${LIBEVENT_INCLUDE_DIR}/event2/event-config.h")
# Libevent 2.0
file(STRINGS "${LIBEVENT_INCLUDE_DIR}/event2/event-config.h"
LIBEVENT_VERSION REGEX "${_version_regex}")
if("${LIBEVENT_VERSION}" STREQUAL "")
set(LIBEVENT_VERSION ${PC_LIBEVENT_VERSION})
endif()
else()
# Libevent 1.4
file(STRINGS "${LIBEVENT_INCLUDE_DIR}/event-config.h"
LIBEVENT_VERSION REGEX "${_version_regex}")
endif()
string(REGEX REPLACE "${_version_regex}" "\\1"
LIBEVENT_VERSION "${LIBEVENT_VERSION}")
unset(_version_regex)
endif()
set(_LIBEVENT_REQUIRED_VARS)
foreach(COMPONENT ${Libevent_FIND_COMPONENTS})
set(_LIBEVENT_LIBNAME libevent)
# Note: compare two variables to avoid a CMP0054 policy warning
if(COMPONENT STREQUAL _LIBEVENT_LIBNAME)
set(_LIBEVENT_LIBNAME event)
else()
set(_LIBEVENT_LIBNAME "event_${COMPONENT}")
endif()
string(TOUPPER "${COMPONENT}" COMPONENT_UPPER)
find_library(LIBEVENT_${COMPONENT_UPPER}_LIBRARY
NAMES ${_LIBEVENT_LIBNAME}
HINTS ${PC_LIBEVENT_LIBRARY_DIRS}
)
if(LIBEVENT_${COMPONENT_UPPER}_LIBRARY)
set(Libevent_${COMPONENT}_FOUND 1)
endif()
list(APPEND _LIBEVENT_REQUIRED_VARS LIBEVENT_${COMPONENT_UPPER}_LIBRARY)
endforeach()
unset(_LIBEVENT_LIBNAME)
include(FindPackageHandleStandardArgs)
# handle the QUIETLY and REQUIRED arguments and set LIBEVENT_FOUND to TRUE
# if all listed variables are TRUE and the requested version matches.
find_package_handle_standard_args(Libevent REQUIRED_VARS
${_LIBEVENT_REQUIRED_VARS}
LIBEVENT_INCLUDE_DIR
VERSION_VAR LIBEVENT_VERSION
HANDLE_COMPONENTS)
if(LIBEVENT_FOUND)
set(LIBEVENT_INCLUDE_DIRS ${LIBEVENT_INCLUDE_DIR})
set(LIBEVENT_LIBRARIES)
foreach(COMPONENT ${Libevent_FIND_COMPONENTS})
string(TOUPPER "${COMPONENT}" COMPONENT_UPPER)
list(APPEND LIBEVENT_LIBRARIES ${LIBEVENT_${COMPONENT_UPPER}_LIBRARY})
set(LIBEVENT_${COMPONENT_UPPER}_FOUND ${Libevent_${COMPONENT}_FOUND})
endforeach()
endif()
mark_as_advanced(LIBEVENT_INCLUDE_DIR ${_LIBEVENT_REQUIRED_VARS})
unset(_LIBEVENT_REQUIRED_VARS)