Re: PATCH: More stdbool tweaking

[Ian Lance Taylor <ian at airs dot com>]

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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/*
 * 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 */