pc doesn't allow an ``others'' clause in outputs

[Chris Torek]

Index: ucb/pc/src 4.2BSD Fix

Description:
	While not strictly a bug, the lack of a specifier for a
	default case label can be quite a pain.  The changes included
	here are straight from Cornell; though their changes were
	for version 2.0, the code has been tested in version 3.0
	and appears to work.

Repeat-By:
	program main (input, output);
	var i : integer;
	begin
		read (i);
		case i of
			1 : writeln ('one');
			2 : writeln ('two');
			others : writeln ('neither one nor two');
		end;
	end.

Fix:
	Apply the appended diff listings.

Chris

RCS file: RCS/hash.c,v
retrieving revision 1.1
diff -c1 -r1.1 hash.c
*** /tmp/,RCSt1004856	Mon Nov  5 01:52:22 1984
--- hash.c	Mon Nov  5 01:18:54 1984
***************
*** 63,64
  	"external",	YEXTERN,
  	0

--- 63,65 -----
  	"external",	YEXTERN,
+ 	"others",	YOTHERS,
  	0
RCS file: RCS/pas.y,v
retrieving revision 1.1
diff -c1 -r1.1 pas.y
*** /tmp/,RCSt1004861	Mon Nov  5 01:52:27 1984
--- pas.y	Mon Nov  5 01:18:37 1984
***************
*** 67,68
  	YCASELAB	YILLCH		YEXTERN		YLAST
  

--- 67,69 -----
  	YCASELAB	YILLCH		YEXTERN		YLAST
+ 	YOTHERS
  
***************
*** 542,543
  		= $$ = tree4(T_CSTAT, lineof($1), NIL, $2);
  		|

--- 543,547 -----
  		= $$ = tree4(T_CSTAT, lineof($1), NIL, $2);
+ 		|
+ 	YOTHERS ':' stat
+ 		= $$ = tree4(T_OTHERCASE, lineof($2), NIL, $3);
  		|
RCS file: RCS/pccaseop.c,v
retrieving revision 1.1
diff -c1 -r1.1 pccaseop.c
*** /tmp/,RCSt1004866	Mon Nov  5 01:52:35 1984
--- pccaseop.c	Mon Nov  5 01:18:46 1984
***************
*** 47,49
       *		[3]	list of cased statements:
!      *			cstat	[0]	T_CSTAT
       *				[1]	lineof ":"

--- 47,49 -----
       *		[3]	list of cased statements:
!      *			cstat	[0]	T_CSTAT  or  T_OTHERCASE
       *				[1]	lineof ":"
***************
*** 68,69
      long	*casep;
      struct ct	*ctab;

--- 68,70 -----
      long	*casep;
+     long	*othercase;
      struct ct	*ctab;
***************
*** 155,156
      count = 0;
      for ( cstatlp = tcase[3] ; cstatlp != NIL ; cstatlp = cstatlp[2] ) {

--- 156,158 -----
      count = 0;
+     othercase = NIL;
      for ( cstatlp = tcase[3] ; cstatlp != NIL ; cstatlp = cstatlp[2] ) {
***************
*** 160,161
  	}
  	line = cstatp[1];

--- 162,171 -----
  	}
+ 	if ( cstatp[0] == T_OTHERCASE ) {
+ 	    if ( othercase != NIL ) {
+ 		error("Too many 'others' cases; only one allowed");
+ 	    } else {
+ 		othercase = cstatp;
+ 	    }
+ 	    continue;
+ 	}
  	line = cstatp[1];
***************
*** 195,197
      }
-     noreach = nr;
  	/*

--- 205,206 -----
      }
  	/*
***************
*** 197,199
  	/*
! 	 *	default action is to call error
  	 */

--- 206,209 -----
  	/*
! 	 *	default action is to call error,
! 	 *	unless there is an ``others:'' label.
  	 */
***************
*** 200,206
      putlab( ctab[0].clabel );
!     putleaf( P2ICON , 0 , 0 , ADDTYPE( P2FTN | P2INT , P2PTR ) , "_CASERNG" );
!     putRV( 0 , cbn , exprnlp -> value[ NL_OFFS ] ,
! 		    exprnlp -> extra_flags , P2INT );
!     putop( P2CALL , P2INT );
!     putdot( filename , line );
  	/*

--- 210,226 -----
      putlab( ctab[0].clabel );
!     if ( othercase == NIL ) {
! 	putleaf( P2ICON , 0 , 0 , ADDTYPE( P2FTN | P2INT , P2PTR ) , "_CASERNG" );
! 	putRV( 0 , cbn , exprnlp -> value[ NL_OFFS ] ,
! 			exprnlp -> extra_flags , P2INT );
! 	putop( P2CALL , P2INT );
! 	putdot( filename , line );
!     } else {
! 	level++;
! 	statement( othercase[3] );
! 	nr = (nr && noreach);
! 	noreach = 0;
! 	level--;
! 	putjbr( endlabel );
!     }
!     noreach = nr;
  	/*
RCS file: RCS/tree.h,v
retrieving revision 1.1
diff -c1 -r1.1 tree.h
*** /tmp/,RCSt1004871	Mon Nov  5 01:52:40 1984
--- tree.h	Mon Nov  5 01:18:49 1984
***************
*** 84
  #define T_LAST 81

--- 84,85 -----
  #define T_LAST 81
+ #define T_OTHERCASE 82

-- 
(This mind accidently left blank.)

In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (301) 454-7690
UUCP:	{seismo,allegra,brl-bmd}!umcp-cs!chris
CSNet:	chris at umcp-cs		ARPA:	chris at maryland