[Scummvm-devel] remove macro conflict in system headers

[Willem Jan Palenstijn]

On Thu, Oct 31, 2013 at 02:21:56PM +0100, Johannes Schickel wrote:
> On Thu, Oct 31, 2013 at 1:55 PM, Willem Jan Palenstijn <wjp at usecode.org>wrote:
> 
> > On Thu, Oct 31, 2013 at 12:35:28AM +0400, Икар wrote:
> > >
> > > When I building Tsage engine for symbian with GCCE 4.4.1 I got many
> > erros "macro `remove' used without args" because compilers think what
> > function :
> > > virtual void remove()=0
> > > and his virtual inheritance comes from macro definition
> > > #define remove(x) unlink(x)
> > > This define placed in sys/unistd.h
> > >
> > >  I try to  use '#undef remove' in core.h but it doesn't work.
> >
> > What do you mean by "doesn't work"?
> >
> > We use remove() in more places than just core.h, so I'm not sure what you
> > tried or how it doesn't work...
> >
> 
> I think he talks about
> https://github.com/scummvm/scummvm/commit08cd61acc249f93c2760fc45b45705c8836fbc7bwhich
> was reverted later. One possibly issue here could've been that you
> undefine such macros by simple "#undef remove" instead of "#undef
> remove(x)". Other issues might include core.h wasn't included in the
> offending files, core.h was included first and then #undef remove was
> before the actual #define.

The #undefine was at the very top of the header, so that does not sound like a
very safe or robust way to undefine something defined in a system header. It
doesn't surprise me at all that it doesn't compile after just thar one change.

-Willem Jan