Re: Remove true/false from GDB ....

Daniel Jacobowitz
2002-02-09T06:03:53Z

On Fri, Feb 08, 2002 at 04:54:41PM -0700, Kevin Buettner wrote:
> On Feb 8, 6:31pm, Andrew Cagney wrote:
>
> > This is fallout from the recent <stdbool.h> problem.
> >
> > "bfd.h" was providing ``true'' and ``false'' as convenience
> > enums/macros/... They unfortunatly clash with systems that provide
> > <stdbool.h> (a header in c99?) and even some systems that don't. The
> > relevant code block is:
> >
> > /* I'm sure this is going to break something and someone is going to
> > force me to change it. */
> > /* typedef enum boolean {false, true} boolean; */
> > /* Yup, SVR4 has a "typedef enum boolean" in <sys/types.h> -fnf */
> > /* It gets worse if the host also defines a true/false enum... -sts */
> > /* And even worse if your compiler has built-in boolean types... -law */
> > /* And even worse if your compiler provides a stdbool.h that conflicts
> > with these definitions... gcc 2.95 and later do. If so, it must
> > be included first. -drow */
> > #if ...
> > ... many valiant attemts to define true and false ...
> > #else
> > /* Use enum names that will appear nowhere else. */
> > typedef enum bfd_boolean {bfd_fffalse, bfd_tttrue} boolean;
> > #endif
> >
> > In short, bfd.h should never have been polluting the name space with
> > ``true'' and ``false''.
> >
> > So the proposal is for "bfd.h" to remove all the above code and instead
> > just define:
> >
> > typedef int bfd_boolean;
> >
> > i.e. 0 is false, non-zero is true, just like C intended :-)
> >
> > Problem is, some blocks of GDB make use of ``true'' and ``false'' and
> > they will need to be changed. Two possabilities come to mind:
> >
> > #include "gdb_stdbool.h"
> > which would wrap <stdbool.h>
> >
> > zap ``true'' and ``false''
> >
> > I've strong preferences for the latter. I think BFD serves as a very
> > compelling example of what not to do :-)
> >
> > thoughts?
>
> If GDB made widespread use of ``true'' and ``false'', I'd suggest
> converting these occurences to ``gdb_true'' and ``gdb_false''. I've
> just looked though and GDB has surprisingly few uses of ``true'' and
> ``false''. That being the case, I like Andrew's latter suggestion of
> just zapping them.
>
> Here's the results of my search after removing the occurrences of
> lines containing true and false in comments:
>
> ./memattr.c[34]: false, /* hwbreak */
> ./memattr.c[35]: false, /* cache */
> ./memattr.c[36]: false /* verify */
> ./memattr.c[185]: attrib.hwbreak = true;
> ./memattr.c[187]: attrib.hwbreak = false;
> ./memattr.c[191]: attrib.cache = true;
> ./memattr.c[193]: attrib.cache = false;
> ./memattr.c[197]: attrib.verify = true;
> ./memattr.c[199]: attrib.verify = false;
> ./corelow.c[172]: return (true);
> ./corelow.c[175]: return (false);
> ./irix5-nat.c[437]: abfd->cacheable = true;
> ./osfsolib.c[256]: abfd->cacheable = true;
> ./solib.c[240]: abfd->cacheable = true;
> ./symfile.c[1097]: sym_bfd->cacheable = true;

So would anyone object if we simply removed all of those?

--
Daniel Jacobowitz Carnegie Mellon University
MontaVista Software Debian GNU/Linux Developer