cmake/nc_cxx.cmake

###############################################################################
if (__nc_cxx)
    return ()
endif ()

set (__nc_cxx TRUE)

###############################################################################
# clear the default flags because they include optimisation flags we
# explicitly do not want (ie, O3).
set (CMAKE_CXX_FLAGS_RELEASE "")
set (CMAKE_C_FLAGS_RELEASE "")
set (CMAKE_CXX_FLAGS_DEBUG "")
set (CMAKE_C_FLAGS_DEBUG "")


###############################################################################
include (compile_flag)
include (link_flag)
include (test_restrict)


###############################################################################
append_compile_flag ("-fdiagnostics-color=auto")


###############################################################################
append_compile_flag ("-std=c++2a")
append_compile_flag ("-fpermissive")
append_compile_flag ("/std:c++latest")

# try to use clangs libc++ under the assumption that gcc will fail this test
# and clang will pass (if it is present). this is necessary because some
# libstdc++ headers don't behave well under c++17/clang.
append_compile_flag ("-stdlib=libc++")

###############################################################################
# find the gcc or clang filesystem library and append to libs if needed
#
# note, we specifically _cannot_ use find_library because it just makes wild
# hardcoded guess and doesn't respect _all_ the system paths; specifically
# something like /usr/lib/gcc/x86_64-pc-linux-gnu/6.3.0/libstdc++.so won't get
# discovered.
#if (NOT DEFINED __nc_cxx_stdcxxfs)
#    foreach(lib "" "c++fs" "c++experimental" "stdc++fs")
#        message (STATUS "Trying c++fs library '${lib}'")
#        try_compile(
#            __nc_cxx_stdcxxfs ${CMAKE_CURRENT_BINARY_DIR}
#        SOURCES
#            ${NC_CMAKE_BASE}/nc_cxx_stdcxxfs.cpp
#        LINK_LIBRARIES
#            ${lib}
#        )
#
#        if (__nc_cxx_stdcxxfs)
#            set (__nc_cxx_stdcxxfs "${lib}" CACHE INTERNAL "library required for c++ filesystem")
#            break ()
#        endif ()
#    endforeach()
#
#    if (NOT DEFINED __nc_cxx_stdcxxfs)
#        message (FATAL_ERROR "Could not locate the required c++fs library")
#    endif ()
#
#    message (STATUS "Using c++fs library ${__nc_cxx_stdcxxfs}")
#endif ()

set(NC_CXX_STDCXXFS ${__nc_cxx_stdcxxfs})


###############################################################################
test_restrict(RESTRICT_KEYWORD)
add_definitions("-Drestrict=${RESTRICT_KEYWORD}")


###############################################################################
append_compile_flag("-pipe")
append_compile_flag("-fno-deduce-init-list")
append_compile_flag("-fvisibility=hidden")
append_compile_flag("-fvisibility-inlines-hidden")
append_compile_flag("-fPIC")

# We want a build-id so that we can attribute minidumps
append_link_flag("-Wl,--build-id")

append_compile_flag("-D__STDC_FORMAT_MACROS")

add_definitions("-D_FILE_OFFSET_BITS=64")