2 # Make sure _GNU_SOURCE is defined where necessary: as early as possible
3 # for configure-time tests, as well as for every source file that includes
8 AC_DEFUN(AC__GNU_SOURCE,
10 # Make sure that _GNU_SOURCE is defined for all subsequent
11 # configure-time compile tests.
12 # This definition must be emitted (into confdefs.h) before any
13 # test that involves compilation.
14 AC_DEFINE(_GNU_SOURCE_KLUDGE, [1
17 #endif], [This definition has a four-line value, the last three of which
18 ensure that _GNU_SOURCE is defined in confdefs.h.])
20 # Emit this code into config.h.in.
21 # The ifndef is to avoid redefinition warnings.
22 AH_VERBATIM([_GNU_SOURCE], [#ifndef _GNU_SOURCE