<!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/3.32.2"> </HEAD> <BODY> On Fri, 2011-12-09 at 07:40 -0800, Keith Packard wrote: <BLOCKQUOTE TYPE=CITE> <PRE> On Fri, 09 Dec 2011 07:45:01 -0500, Gaetan Nadon <<A HREF="mailto:memsize@videotron.ca">memsize@videotron.ca</A>> wrote: > This function is deprecated because it defines -fno-strict-aliasing > which alters the code generated by the compiler. If -fno-strict-aliasing > is needed, then it should be added explicitly in the module when > it is updated to use BASE_CFLAGS. Does this change the default for this flag? -fno-strict-aliasing is needed to preserve compatibility with older code, and I think it should probably be on by default until a module owner disables it manually. </PRE> </BLOCKQUOTE> The content for CWARNFLAGS will always contain -fno-strict-aliasing. <BLOCKQUOTE> <PRE> # XORG_CWARNFLAGS # --------------- # Minimum version: 1.2.0 # Deprecated since: 1.16.0 (Use XORG_COMPILER_FLAGS instead) # # Defines CWARNFLAGS to enable C compiler warnings. # # This function is deprecated because it defines -fno-strict-aliasing # which alters the code generated by the compiler.  If -fno-strict-aliasing # is needed, then it should be added explicitly in the module when # it is updated to use BASE_CFLAGS. # AC_DEFUN([XORG_CWARNFLAGS], [ AC_REQUIRE([XORG_COMPILER_FLAGS]) AC_REQUIRE([XORG_COMPILER_BRAND]) CWARNFLAGS="$BASE_CFLAGS" if  test "x$GCC" = xyes ; then     CWARNFLAGS="$CWARNFLAGS -fno-strict-aliasing" fi AC_SUBST(CWARNFLAGS) ]) # XORG_CWARNFLAGS </PRE> </BLOCKQUOTE> An alternative is now available which separates the warning flags from -fno-strict-aliasing. In the xserver configuration file, CWARNFLAGS has been replaced with: <BLOCKQUOTE> <PRE> XORG_TESTSET_CFLAG([NO_STRICT_ALIASING_CFLAG], [-fno-strict-aliasing]) XSERVER_CFLAGS='$(BASE_CFLAGS) $(NO_STRICT_ALIASING_CFLAG)' AC_SUBST([NO_STRICT_ALIASING_CFLAG]) </PRE> </BLOCKQUOTE> which is equivalent to CWARNFLAGS in terms of -fno-strict-aliasing. This separation allows (many) modules who do not want -fno-strict-aliasing to get the warning flags only. I originally thought that CWARNFLAGS would fall behind in terms of warning flags (past discussions), but I just noticed Jeremy reimplemented it such that it will be updated whenever the BASE_CFLAGS variable is updated. It isn't as deprecated as the comment says. Thanks for talking a look at this. </BODY> </HTML>