[Bug preprocessor/33907] Empty macro definitions not considered equal

["manu at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #13 from manu at gcc dot gnu dot org  2007-11-26 13:03 -------
(In reply to comment #11)
> I see.  But sth changed in the cpp defaults for C++ in 4.3 as things
> that were previously warnings (with 4.2) are now errors (with 4.3), such
> as this one or the macro re-definition.
> 

(My english must be getting pretty bad lately, please let me know what part is
not clear. Perhaps we should put up some Developers FAQ in the wiki.)

* C++ front-end did not and does not enable -pedantic-errors by default. 

* C++ front-end makes pedwarns to be emitted as errors.

* -pedantic-errors sets the variable pedantic to true and makes pedwarns to be
emitted as errors.

* C++ front-end in 4.3 now makes CPP's pedwarns to be emitted as errors.

* C++ front-end in 4.3 did not and does not set CPP's pedantic flag to true,
you still need -pedantic or -pedantic-errors for that.

* So, a CPP's pedwarn that is guarded by the pedantic flag still requires an
explicit -pedantic or -pedantic-errors in the command-line to be generated (as
error by default, as a warning with -fpermissive).

Please, I am banging my head against the wall since comment #7 of why this is
not clear. So, please, let me know which part I am explaining wrong.


-- 

manu at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2007-11-25 22:23:50         |2007-11-26 13:03:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=33907