# Check linker capabilities
#
# Copyright © 2015 Open Microscopy Environment / University of Dundee
# Copyright © 2021 Roger Leigh <rleigh@codelibre.net>
# Written by Roger Leigh <rleigh@codelibre.net>
#
# Permission to use, copy, modify, distribute, and sell this software and
# its documentation for any purpose is hereby granted without fee, provided
# that (i) the above copyright notices and this permission notice appear in
# all copies of the software and related documentation, and (ii) the names of
# Sam Leffler and Silicon Graphics may not be used in any advertising or
# publicity relating to the software without the specific, prior written
# permission of Sam Leffler and Silicon Graphics.
#
# THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
# EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
# WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
#
# IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
# ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
# OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
# WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
# LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
# OF THIS SOFTWARE.


include(CheckCSourceCompiles)


if (FALSE) # XXX(kitware): hardcode settings
option(ld-version-script "Enable linker version script" ON)
else ()
set(ld-version-script ON)
endif ()

# Check if LD supports linker scripts.
file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map" "VERS_1 {
        global: sym;
};

VERS_2 {
        global: sym;
} VERS_1;
")
set(CMAKE_REQUIRED_FLAGS_SAVE ${CMAKE_REQUIRED_FLAGS})
set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS} "-Wl,--version-script=${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
check_c_source_compiles("int main(void){return 0;}" HAVE_LD_VERSION_SCRIPT)
set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS_SAVE})
file(REMOVE "${CMAKE_CURRENT_BINARY_DIR}/conftest.map")
if (ld-version-script AND HAVE_LD_VERSION_SCRIPT AND NOT CMAKE_GENERATOR MATCHES "Xcode")
    set(HAVE_LD_VERSION_SCRIPT TRUE)
else()
    set(HAVE_LD_VERSION_SCRIPT FALSE)
endif()