BSD 4 release

[unix-history] / usr / src / cmd / pc0 / lab.c

/* Copyright (c) 1979 Regents of the University of California */

static  char sccsid[] = "@(#)lab.c 1.5 10/14/80";

#include "whoami.h"
#include "0.h"
#include "tree.h"
#include "opcode.h"
#include "objfmt.h"
#ifdef PC
#   include     "pc.h"
#   include     "pcops.h"
#endif PC

/*
* Label enters the definitions
* of the label declaration part
* into the namelist.
*/
label(r, l)
       int *r, l;
{
#ifndef PI0
       register *ll;
       register struct nl *p, *lp;

       lp = NIL;
#else
       send(REVLAB, r);
#endif
       if ( ! progseen ) {
           level1();
       }
       line = l;
#ifndef PI1
       if (parts[ cbn ] & (CPRT|TPRT|VPRT|RPRT)){
           if ( opt( 's' ) ) {
               standard();
           } else {
               warning();
           }
           error("Label declarations should precede const, type, var and routine declarations");
       }
       if (parts[ cbn ] & LPRT) {
           if ( opt( 's' ) ) {
               standard();
           } else {
               warning();
           }
           error("All labels should be declared in one label part");
       }
       parts[ cbn ] |= LPRT;
#endif
#ifndef PI0
       for (ll = r; ll != NIL; ll = ll[2]) {
               l = getlab();
               p = enter(defnl(ll[1], LABEL, 0, l));
               /*
                * Get the label for the eventual target
                */
               p->value[1] = getlab();
               p->chain = lp;
               p->nl_flags |= (NFORWD|NMOD);
               p->value[NL_GOLEV] = NOTYET;
               p->entloc = l;
               lp = p;
#               ifdef OBJ
                   /*
                    * This operator is between
                    * the bodies of two procedures
                    * and provides a target for
                    * gotos for this label via TRA.
                    */
                   putlab(l);
                   put2(O_GOTO | cbn<<8+INDX, p->value[1]);
#               endif OBJ
#               ifdef PC
                   /*
                    *  labels have to be .globl otherwise /lib/c2 may
                    *  throw them away if they aren't used in the function
                    *  which defines them.
                    */
                   {
                       char    extname[ BUFSIZ ];
                       char    *starthere;
                       int     i;

                       starthere = &extname[0];
                       for ( i = 1 ; i < cbn ; i++ ) {
                           sprintf( starthere , EXTFORMAT , enclosing[ i ] );
                           starthere += strlen( enclosing[ i ] ) + 1;
                       }
                       sprintf( starthere , EXTFORMAT , p -> symbol );
                       starthere += strlen( p -> symbol ) + 1;
                       if ( starthere >= &extname[ BUFSIZ ] ) {
                           panic( "lab decl namelength" );
                       }
                       putprintf( "    .globl  " , 1 );
                       putprintf( NAMEFORMAT , 0 , extname );
                       if ( cbn == 1 ) {
                           stabglabel( extname , line );
                       }
                   }
#               endif PC
       }
       gotos[cbn] = lp;
#       ifdef PTREE
           {
               pPointer        Labels = LabelDCopy( r );

               pDEF( PorFHeader[ nesting ] ).PorFLabels = Labels;
           }
#       endif PTREE
#endif
}

#ifndef PI0
/*
* Gotoop is called when
* we get a statement "goto label"
* and generates the needed tra.
*/
gotoop(s)
       char *s;
{
       register struct nl *p;

       gocnt++;
       p = lookup(s);
       if (p == NIL)
               return (NIL);
#       ifdef OBJ
           put2(O_TRA4, p->entloc);
#       endif OBJ
#       ifdef PC
           if ( cbn != bn ) {
                   /*
                    *  call goto to unwind the stack to the destination level
                    */
               putleaf( P2ICON , 0 , 0 , ADDTYPE( P2FTN | P2INT , P2PTR )
                       , "_GOTO" );
               putLV( DISPLAYNAME , 0 , bn * sizeof( struct dispsave )
                       , P2PTR | P2INT );
               putop( P2CALL , P2INT );
               putdot( filename , line );
           }
           {
               char    extname[ BUFSIZ ];
               char    *starthere;
               int     i;

               starthere = &extname[0];
               for ( i = 1 ; i < bn ; i++ ) {
                   sprintf( starthere , EXTFORMAT , enclosing[ i ] );
                   starthere += strlen( enclosing[ i ] ) + 1;
               }
               sprintf( starthere , EXTFORMAT , p -> symbol );
               starthere += strlen( p -> symbol ) + 1;
               if ( starthere >= &extname[ BUFSIZ ] ) {
                   panic( "goto namelength" );
               }
               putprintf( "    jbr     " , 1 );
               putprintf( NAMEFORMAT , 0 , extname );
           }
#       endif PC
       if (bn == cbn)
               if (p->nl_flags & NFORWD) {
                       if (p->value[NL_GOLEV] == NOTYET) {
                               p->value[NL_GOLEV] = level;
                               p->value[NL_GOLINE] = line;
                       }
               } else
                       if (p->value[NL_GOLEV] == DEAD) {
                               recovered();
                               error("Goto %s is into a structured statement", p->symbol);
                       }
}

/*
* Labeled is called when a label
* definition is encountered, and
* marks that it has been found and
* patches the associated GOTO generated
* by gotoop.
*/
labeled(s)
       char *s;
{
       register struct nl *p;

       p = lookup(s);
       if (p == NIL)
               return (NIL);
       if (bn != cbn) {
               error("Label %s not defined in correct block", s);
               return;
       }
       if ((p->nl_flags & NFORWD) == 0) {
               error("Label %s redefined", s);
               return;
       }
       p->nl_flags &= ~NFORWD;
#       ifdef OBJ
           patch4(p->entloc);
#       endif OBJ
#       ifdef PC
           {
               char    extname[ BUFSIZ ];
               char    *starthere;
               int     i;

               starthere = &extname[0];
               for ( i = 1 ; i < bn ; i++ ) {
                   sprintf( starthere , EXTFORMAT , enclosing[ i ] );
                   starthere += strlen( enclosing[ i ] ) + 1;
               }
               sprintf( starthere , EXTFORMAT , p -> symbol );
               starthere += strlen( p -> symbol ) + 1;
               if ( starthere >= &extname[ BUFSIZ ] ) {
                   panic( "labeled namelength" );
               }
               putprintf( NAMEFORMAT , 1 , extname );
               putprintf( ":" , 0 );
           }
#       endif PC
       if (p->value[NL_GOLEV] != NOTYET)
               if (p->value[NL_GOLEV] < level) {
                       recovered();
                       error("Goto %s from line %d is into a structured statement", s, p->value[NL_GOLINE]);
               }
       p->value[NL_GOLEV] = level;
}
#endif