<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 TRANSITIONAL//EN"> <HTML> <HEAD> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; CHARSET=UTF-8"> <META NAME="GENERATOR" CONTENT="GtkHTML/3.26.0"> </HEAD> <BODY> On Mon, 2010-11-01 at 13:40 -0700, Jeremy Huddleston wrote: <BLOCKQUOTE TYPE=CITE> <TT>I don't think that's the correct model.  -fstrict-aliasing is on by default (for many users), and -fno-strict-aliasing should be what is opted into in order to disable optimizations that rely on correctly written C code.</TT> <TT>>> XORG_CWARNFLAGS would be updated to call these two and set CWARNFLAGS="$(CFLAGS_WARNINGS) $(CFLAGS_NO_STRICT_ALIASING)"</TT> <TT>> </TT> <TT>> Nope. Our good old CWARNFLAGS would remain untouched for eternity and</TT> <TT>> will eventually fall off the radar screen.</TT> <TT>Well, I think that in the spirit of abstraction and code-reuse, it would be best to have it call the two new macros... but I guess that is contingent on our dispute over opting-in to -fno-strict-aliasing versus -fstrict-aliasing.</TT> <TT>...</TT> <TT>>> For modules that did have it historically, we'll leave them alone initially.  </TT> <TT>>> As we audit them, we'll change CWARNFLAGS to either CFLAGS_WARNINGS or CFLAGS_WARNINGS CFLAGS_NO_STRICT_ALIASI.  </TT> <TT>>> This will help us keep track of what has been audited to determine what really needs </TT> <TT>>> the flag versus what might've inherited it by accident.</TT> <TT>> </TT> <TT>> Those modules would use both the new CFLAGS_WARNINGS and the new</TT> <TT>> CFLAGS_STRICT_ALIASING, under an opt-in principle</TT> <TT>I'm confused now.  If they actually *NEED* -fno-strict-aliasing, how are you proposing adding -fno-strict-aliasing?  This is why I was suggesting a CFLAGS_NO_STRICT_ALIASING</TT> </BLOCKQUOTE> Sorry, I got confused. I forgot -O brings strict aliasing by default. We need one new variable for "real warnings" and one variable for <TT>-fno-strict-aliasing</TT><TT>. Modules would typically use the new "real warnings" variable and some would pick the new "</TT><TT>-fno-strict-aliasing</TT><TT>" variable (the server and drivers for example). The CWARNFLAGS is untouched for backward compatibility. I hope I got it right :-)</TT> For the server, it would be $(CFLAGS_WARNINGS) + $(CFLAGS_NO_STRICT_ALIASING) For libXxf86vm, it would be $(CFLAGS_WARNINGS) </BODY> </HTML>