Andrew John Hughes wrote: > 2009/10/23 Andrew Haley <aph@xxxxxxxxxx>: >> Andrew John Hughes wrote: >>> 2009/10/22 Andrew Haley <aph@xxxxxxxxxx>: >>>> This: >>>> >>>> >>>> #ifdef HAVE_GETPEERNAME >>>> #ifdef HAVE_INET6 >>>> struct sockaddr_in6 *addr6; >>>> struct sockaddr_in6 sock_storage; >>>> socklen_t socklen = sizeof (struct sockaddr_in6); >>>> #else >>>> struct sockaddr_in sock_storage; >>>> socklen_t socklen = sizeof (struct sockaddr_in); >>>> #endif /* HAVE_INET6 */ >>>> >>>> struct sockaddr *sockaddr = (struct sockaddr *) &sock_storage; >>>> >>>> >>>> is clearly an aliasing violation: sock_storage is of type struct sockaddr_in6, >>>> and *sockaddr is of type struct sockaddr. >>>> >>>> It would be easy enough to fix the code with a union, but I can't test it >>>> because gcj doesn't use this code. I could simply compile with >>>> -fno-strict-aliasing. >>>> >>>> Thoughts? >>>> >>>> Andrew. >>>> >>>> >>> I posted a patch sometime ago to do exactly that (use a union), but >>> received no response: >>> >>> http://developer.classpath.org/pipermail/classpath-patches/2009-June/006341.html >>> >>> It does need more testing than I've had chance to give it so far, I >>> just haven't had time to do any more work on it. >> I seriously wonder if it's worth the effort. I just did this: >> >> Index: configure.ac >> =================================================================== >> RCS file: /sources/classpath/classpath/configure.ac,v >> retrieving revision 1.244 >> diff -c -u -r1.244 configure.ac >> --- configure.ac 6 Feb 2009 02:21:23 -0000 1.244 >> +++ configure.ac 23 Oct 2009 09:10:33 -0000 >> @@ -514,7 +514,7 @@ >> dnl CFLAGS that are used for all native code. We want to compile >> dnl everything with unwinder data so that backtrace() will always >> dnl work. >> - EXTRA_CFLAGS='-fexceptions -fasynchronous-unwind-tables' >> + EXTRA_CFLAGS='-fexceptions -fasynchronous-unwind-tables -fno-strict-aliasing' >> AC_SUBST(EXTRA_CFLAGS) >> >> dnl Strict warning flags which not every module uses. >> >> which is a much safer change. It will somewhat pessimize other native code, >> that's true, but will that make any real difference to anyone these days? > > Why not just amend the CFLAGS in the local Makefile.am for cpnet? Sure. It won't make much difference, I suspect. Andrew.
