# Copyright (C) 2017-2020 LAAS-CNRS, JRL AIST-CNRS.
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation, either version 3 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program.  If not, see <http://www.gnu.org/licenses/>.

include(CheckCCompilerFlag)
# Introduced in 3.18.0 but VERSION_GREAT_OR_EQUAL is not available in CMake 3.1
if(${CMAKE_VERSION} VERSION_LESS 3.18.0)
  # Do nothing
else()
  include(CheckLinkerFlag)
endif()

# _CHECK_VERSION_SCRIPT_SUPPORT
# -----------------------------
#
# Internal macro to check if version scripts are supported by the current
# linker.
macro(_CHECK_VERSION_SCRIPT_SUPPORT)
  set(VERSION_SCRIPT "${PROJECT_JRL_CMAKE_MODULE_DIR}/version-script-test.lds")
  if(COMMAND check_linker_flag)
    check_linker_flag(
      "C"
      "-Wl,--version-script=${VERSION_SCRIPT}"
      HAS_VERSION_SCRIPT_SUPPORT
    )
  else()
    check_c_compiler_flag(
      "-Wl,--version-script=${VERSION_SCRIPT}"
      HAS_VERSION_SCRIPT_SUPPORT
    )
  endif()
  set(
    _HAS_VERSION_SCRIPT_SUPPORT
    ${HAS_VERSION_SCRIPT_SUPPORT}
    CACHE INTERNAL
    "Linker supports version scripts"
  )
endmacro(_CHECK_VERSION_SCRIPT_SUPPORT)

# .rst: .. command:: ADD_VERSION_SCRIPT(TARGET VERSION_SCRIPT)
#
# This macro adds a version script to a given target and a link-time dependency
# between the target and the version script.
#
# See
# https://www.gnu.org/software/gnulib/manual/html_node/LD-Version-Scripts.html
#
# It has no effect on platforms that do not support version script.
#
# :param TARGET:         Name of the target, the macro does nothing if TARGET is
# not a cmake target. :param VERSION_SCRIPT: Version script to add to the
# library.
#
macro(ADD_VERSION_SCRIPT TARGET VERSION_SCRIPT)
  if(NOT DEFINED _HAS_VERSION_SCRIPT_SUPPORT)
    _CHECK_VERSION_SCRIPT_SUPPORT()
  endif()
  if(_HAS_VERSION_SCRIPT_SUPPORT)
    if(TARGET ${TARGET})
      set_property(
        TARGET ${TARGET}
        APPEND_STRING
        PROPERTY LINK_FLAGS " -Wl,--version-script=${VERSION_SCRIPT}"
      )
      set_target_properties(${TARGET} PROPERTIES LINK_DEPENDS ${VERSION_SCRIPT})
    endif()
  endif()
endmacro(ADD_VERSION_SCRIPT)