On Wed, Feb 18, 2015 at 01:16:55PM +0100, Jakub Jelinek wrote: > On Wed, Feb 18, 2015 at 01:04:30PM +0100, Marek Polacek wrote: > > --- porting_to.html 10 Feb 2015 11:12:20 -0000 1.3 > > +++ porting_to.html 18 Feb 2015 12:01:50 -0000 > > @@ -24,6 +24,17 @@ > > manner. Additions and suggestions for improvement are welcome. > > </p> > > > > +<h2>Preprocessor issues</h2> > > + > > +<p>The preprocessor started to emit line markers to properly distinguish > > +whether a macro token comes from a system header, or from a normal header > > +(see <a > > href="https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60723">PR60723</a>). > > +These new markers can cause intriguing problems, if the packages aren't > > ready > > +to handle them. To stop the preprocessor from generating the > > <code>#line</code> > > +directives, use the <code>-P</code> option, documented > > +<a > > href="https://gcc.gnu.org/onlinedocs/gcc/Preprocessor-Options.html#Preprocessor-Options">here</a>. > > +</p> > > I think it would be nice to give here some example, like: > #include <stdlib.h> > exitfailure EXIT_FAILURE > and showing that older gcc -E used to emit > # 2 "test.c" 2 > exitfailure 1 > whereas GCC 5 emits: > # 2 "test.c" 2 > > # 2 "test.c" > exitfailure > # 2 "test.c" 3 4 > 1 > and thus it can break simple tools that expect the tokens on a single line.
Added. > Otherwise, LGTM. Thanks, committed now. Marek