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. Otherwise, LGTM. Jakub