build: probe the compiler to see if we need to turn down _FORTIFY_SOURCE

Some builds don't use Release (such as Gentoo, though it can be told
to).  So let's go a bit further and probe the compiler to see if we need
to turn down the _FORTIFY_SOURCE level.
This commit is contained in:
John Szakmeister 2014-11-21 03:42:59 -05:00
parent 68fcd8b696
commit 7b6f705e5f

View File

@ -73,8 +73,19 @@ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wconversion")
# gcc 4.0 and better turn on _FORTIFY_SOURCE=2 automatically. This currently
# does not work with Neovim due to some uses of dynamically-sized structures.
# See https://github.com/neovim/neovim/issues/223 for details.
if(CMAKE_COMPILER_IS_GNUCC AND NOT CMAKE_C_COMPILER_VERSION VERSION_LESS "4"
AND CMAKE_BUILD_TYPE MATCHES "^Rel")
include(CheckCSourceCompiles)
check_c_source_compiles("
#if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 1
#error \"_FORTIFY_SOURCE > 1\"
#endif
int
main(void)
{
return 0;
}
" _FORTIFY_SOURCE_ACCEPTABLE)
if(NOT _FORTIFY_SOURCE_ACCEPTABLE)
# -U in add_definitions doesn't end up in the correct spot, so we add it to
# the flags variable instead.
set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1")