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From: manning@halley.tmc.edu (Arthur T. Manning)
Newsgroups: comp.os.os9
Subject: inconsistent *** illegal type combination *** error
Message-ID: <1991Jun18.123455.12845@mmm.serc.3m.com>
Date: 18 Jun 91 12:34:55 GMT
Organization: Minnesota Mining & Manufacturing
Lines: 46

cc68 doesn't behave consistently with types.  It will complain about
it in certain cases, but not in others due to nothing other than
THE ORDER OF OPERANDS.  cc68 is not comutative with == .

try this code:
/**************************************************************************/
/* test for bad type combination */

#include <stdio.h>

foo()
{
  FILE *fptr;

  fptr=fopen("badtype.c","r");

  if ( fptr == NULL )		/* no complaint here! */
    printf("couldn't open\n");

  if ( NULL == fptr )		/* cc68 complains about this line */
    printf("couldn't open\n");

}

/* cc68 output:
% cc68 -r badtype.c

'badtype.c'
cpp:
c68:
"badtype.c", line 15: ****  illegal type combination ****
  if ( 0 == fptr )
            ^
errors in compilation : 1
% 
****************************************************************************/



QED.

--
Arthur T. Manning   <manning@halley.est.3m.com>  
3M Center 518-1    St Paul MN  55144-1000        \___/______         
ph. 612 733-4401   fax 612 736-3122             __  / _ _ _  \
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