Portable C Compiler Bug

[Chris Torek]

In article <2737 at uvacs.cs.Virginia.EDU> amh at uvacs.cs.Virginia.EDU
(Anne M. Holler) writes:
>...3.  The bug causes the compiler to sometimes fail giving the error
>message "schain botch".

Yes.  Anne's fix should work.  The bug is already fixed in
4.3BSD-tahoe; here is the `official' fix.  Your line numbers will
differ.

***************
*** 1854,1859 ****
  	/* step 1: remove entries */
  	while( chaintop-1 > lev ){
- 		register int type;
- 
  		p = schain[--chaintop];
  		schain[chaintop] = 0;
--- 1890,1893 ----
***************
*** 1860,1864 ****
  		for( ; p; p = q ){
  			q = p->snext;
- 			type = p->stype;
  			if( p->stype == TNULL || p->slevel <= lev )
  				cerror( "schain botch" );
--- 1894,1897 ----
***************
*** 1894,1898 ****
  	p = clist;
  	while( p ){
! 		register struct symtab *r, *next;
  
  		q = p;
--- 1927,1931 ----
  	p = clist;
  	while( p ){
! 		register struct symtab *next, **t, *r;
  
  		q = p;
***************
*** 1902,1905 ****
--- 1935,1946 ----
  			if( q == p || q->stype == TNULL )break;
  			if( (r = relook(q)) != q ) {
+ 				/* move q in schain list */
+ 				t = &schain[q->slevel];
+ 				while( *t && *t != q )
+ 					t = &(*t)->snext;
+ 				if( *t )
+ 					*t = r;
+ 				else
+ 					cerror("schain botch 2");
  				*r = *q;
  				q->stype = TNULL;
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris at mimsy.umd.edu	Path:	uunet!mimsy!chris