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PATCH: More stdbool tweaking

Ian Lance Taylor ian@airs.com
Thu Feb 7 14:19:00 GMT 2002 
Daniel Jacobowitz <drow@mvista.com> writes:

> > The only bfd.h issue is the definitions of true and false.  Daniel has
> > proposed a simple patch which works provided stdbool.h is included first.  I
> > already proposed a simple patch which should work in all cases:
> >     http://sources.redhat.com/ml/binutils/2002-02/msg00068.html
> > However, I have not tested it.
> 
> (Is the assumption that the first thing in an enum has value 0 always
> valid?  I think so, but not sure.)

Yes.  If it were not, the current code would not work.  A lot of code
in BFD uses a boolean by saying
    if (b)
If false were not 0, this would fail.

> In any case, your patch would not finesse the problem.  False is
> defined to 'false', an enum value, in <stdbool.h>.  While the value
> false evalutates to 0, that would not fix the problem, since it is not
> the same.

Not in the version of stdbool.h distributed with gcc 3.0.3.  I have
appended it.  Can you send a copy of the stdbool.h which you are
looking at?  Don't get confused by the C++ code.

Ian

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/* As a special exception, if you include this header file into source
   files compiled by GCC, this header file does not by itself cause
   the resulting executable to be covered by the GNU General Public
   License.  This exception does not however invalidate any other
   reasons why the executable file might be covered by the GNU General
   Public License.  */

/*
 * ISO C Standard:  7.16  Boolean type and values  <stdbool.h>
 */

#ifndef _STDBOOL_H
#define _STDBOOL_H

#ifndef __cplusplus

#define bool	_Bool
#define true	1
#define false	0

#else /* __cplusplus */

/* Supporting <stdbool.h> in C++ is a GCC extension.  */
#define _Bool	bool
#define bool	bool
#define false	false
#define true	true

#endif /* __cplusplus */

/* Signal that all the definitions are present.  */
#define __bool_true_false_are_defined	1

#endif	/* stdbool.h */
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