#[=======================================================================[.rst:
FindLibDW
---------

Find libdw, the elfutils library for DWARF data and ELF file or process inspection.

Variables that affect this module

``LibDW_NO_SYSTEM_PATHS``
  If `True`, no system paths are searched.

Imported targets
^^^^^^^^^^^^^^^^

This module defines the following :prop_tgt:`IMPORTED` target:

``LibDW::LibDW``
  The libdw library, if found.

Result variables
^^^^^^^^^^^^^^^^

This module will set the following variables in your project:

``LibDW_INCLUDE_DIRS``
  where to find libdw.h, etc.
``LibDW_LIBRARIES``
  the libraries to link against to use libdw.
``LibDW_FOUND``
  If false, do not try to use libdw.
``LibDW_VERSION``
  the version of the libdw library found

#]=======================================================================]
cmake_policy(SET CMP0074 NEW) # Use <Package>_ROOT

if(LibDW_NO_SYSTEM_PATHS)
    set(_find_path_args NO_CMAKE_SYSTEM_PATH NO_SYSTEM_ENVIRONMENT_PATH)
endif()

# There is no way to tell pkg-config to ignore directories, so disable it
if(NOT LibDW_NO_SYSTEM_PATHS)
    find_package(PkgConfig QUIET)
    if(PKG_CONFIG_FOUND)
        if(NOT "x${LibDW_FIND_VERSION}" STREQUAL "x")
            set(_version ">=${LibDW_FIND_VERSION}")
        endif()
        if(LibDW_FIND_QUIETLY)
            set(_quiet "QUIET")
        endif()

        pkg_check_modules(PC_LIBDW ${_quiet} "libdw${_version}")
        unset(_version)
        unset(_quiet)
    endif()
endif()

if(PC_LIBDW_FOUND)
    # FindPkgConfig sometimes gets the include dir wrong
    if("x${PC_LIBDW_INCLUDE_DIRS}" STREQUAL "x")
        pkg_get_variable(PC_LIBDW_INCLUDE_DIRS libdw includedir)
    endif()

    set(LibDW_INCLUDE_DIRS ${PC_LIBDW_INCLUDE_DIRS} CACHE PATH "")
    set(LibDW_LIBRARIES ${PC_LIBDW_LINK_LIBRARIES} CACHE PATH "")
    set(LibDW_VERSION ${PC_LIBDW_VERSION} CACHE STRING "")
else()
    find_path(LibDW_INCLUDE_DIRS NAMES libdw.h PATH_SUFFIXES elfutils ${_find_path_args})

    find_library(LibDW_LIBRARIES NAMES libdw dw PATH_SUFFIXES elfutils ${_find_path_args})

    if(EXISTS "${LibDW_INCLUDE_DIRS}/version.h")
        file(
            STRINGS "${LibDW_INCLUDE_DIRS}/version.h"
            _version_line
            REGEX "^#define _ELFUTILS_VERSION[ \t]+[0-9]+"
        )
        string(REGEX MATCH "[0-9]+" _version "${_version_line}")
        if(NOT "x${_version}" STREQUAL "x")
            set(LibDW_VERSION "0.${_version}")
        endif()
        unset(_version_line)
        unset(_version)
    endif()
endif()

include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(
    LibDW
    FOUND_VAR LibDW_FOUND
    REQUIRED_VARS LibDW_LIBRARIES LibDW_INCLUDE_DIRS
    VERSION_VAR LibDW_VERSION
)

if(LibDW_FOUND)
    mark_as_advanced(LibDW_INCLUDE_DIRS)
    mark_as_advanced(LibDW_LIBRARIES)
    mark_as_advanced(LibDW_VERSION)

    # Some platforms explicitly list libelf as a dependency, so separate it out
    list(LENGTH LibDW_LIBRARIES _cnt)
    if(${_cnt} GREATER 1)
        foreach(_l ${LibDW_LIBRARIES})
            if(${_l} MATCHES "libdw")
                set(_libdw ${_l})
            else()
                list(APPEND _link_libs ${_l})
            endif()
        endforeach()
    endif()
    unset(_cnt)

    if(NOT TARGET LibDW::LibDW)
        add_library(LibDW::LibDW UNKNOWN IMPORTED)
        set_target_properties(
            LibDW::LibDW
            PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${LibDW_INCLUDE_DIRS}"
        )

        if(NOT "x${_link_libs}" STREQUAL "x")
            set_target_properties(
                LibDW::LibDW
                PROPERTIES
                    IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                    IMPORTED_LINK_DEPENDENT_LIBRARIES "${_link_libs}"
            )
            set(LibDW_LIBRARIES ${_libdw})
            unset(_libdw)
            unset(_link_libs)
        endif()

        set_target_properties(
            LibDW::LibDW
            PROPERTIES
                IMPORTED_LINK_INTERFACE_LANGUAGES "C"
                IMPORTED_LOCATION "${LibDW_LIBRARIES}"
        )
    endif()
endif()

unset(_find_path_args)