maint: make it easier to copy FORTIFY_SOURCE snippet

While libvirt intentionally avoids -Wundef (after all, C99
guarantees sane semantics of treating undefined macros as 0),
the glibc insanity of #warning on _FORTIFY_SOURCE coupled with
what some people feel is the black magic of autoconf means
that other projects are likely to copy our snippet verbatim.
We can be nicer to other projects by making it easier to
integrate into projects that use -Wundef.

Suggested by Christophe Fergeau.

* m4/virt-compile-warnings.m4 (LIBVIRT_COMPILE_WARNINGS): Be nice
to other projects using -Wundef.
(cherry picked from commit 1c2edf0fbd)
This commit is contained in:
Eric Blake 2012-06-07 10:48:05 -06:00 committed by Cole Robinson
parent 55157abb0b
commit 29263ec243

View File

@ -103,8 +103,9 @@ AC_DEFUN([LIBVIRT_COMPILE_WARNINGS],[
AC_DEFINE([lint], [1],
[Define to 1 if the compiler is checking for lint.])
AH_VERBATIM([FORTIFY_SOURCE],
[/* Enable compile-time and run-time bounds-checking, and some warnings. */
#if __OPTIMIZE__
[/* Enable compile-time and run-time bounds-checking, and some warnings,
without upsetting newer glibc. */
#if defined __OPTIMIZE__ && __OPTIMIZE__
# define _FORTIFY_SOURCE 2
#endif
])