RE: Void functions returning NULL

[Tim Auckland]

An example of mixing char and unsigned char is the use of the first
argument of ChecksumChanged()

prototypes.h:

        int ChecksumChanged ARGLIST((char *filename, unsigned char
digest  [EVP_MAX_MD_SIZE+1], int warnlevel, int refresh, char type));

cfservd.c, CompareLocalChecksum()

        { unsigned char digest[EVP_MAX_MD_SIZE+1],filename[bufsize];
        ...
        if (ChecksumChanged(filename,digest,cfverbose,true,'m'))
        ...


An example of mixing void and void* is in cfservd.c:

        void ExitCleanly ARGLIST((int signum));
        ...
        signal(SIGINT,(void*)ExitCleanly);
        ...

Returning void and returning NULL are not the same thing.  NULL is
defined in many places, but they usually boil down to '0', '0L', or
(void *)0L.  None of these can legally be returned by a function
declared void.

Tim 

> -----Original Message-----
> From: address@hidden [mailto:address@hidden 
> Sent: Thursday, September 12, 2002 11:47 AM
> To: Tim Auckland
> Cc: address@hidden
> Subject: Re: Void functions returning NULL
> 
> 
> 
> The HPUX compiler is especially tough on these messages. Many 
> of them are caused by inconsistencies in datatypes between 
> platforms. The return values were a cut and paste error that 
> have no effect on the program, since the function is void. 
> Mixing void and void* is potentially more serious - can you 
> be specific?
> 
> M
> 
> On 12 Sep, Tim Auckland wrote:
> > FYI,
> > 
> > I just tried to compile cfengine 2.0.4 on HP-UX 11 with HP's C 
> > compiler.
> > 
> > The compile failed in cfservd.c where several functions have been 
> > declared "void" but contain one of more "return NULL" instructions. 
> > HP's C compiler doesn't let you get away with this (and I'm not 
> > surprised!).
> > 
> > Commenting out the NULLs fixes the problem.
> > 
> > (It still complains a lot about incorrect types where "char" and 
> > "unsigned char" have been freely mixed and also "void" and "void*", 
> > but those at least don't prevent compilation).
> > 
> > Tim
> > 
> > 
> > _______________________________________________
> > Bug-cfengine mailing list
> > address@hidden 
> http://mail.gnu.org/mailman/listinfo/bug-> cfengine
> 
> 
> 
> 
> 
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