4.1cBSD/usr/src/ucb/pascal/src/lab.c
/* Copyright (c) 1979 Regents of the University of California */
static char sccsid[] = "@(#)lab.c 1.17 2/1/83";
#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;
{
static bool label_order = FALSE;
static bool label_seen = FALSE;
#ifdef PC
char extname[ BUFSIZ ];
#endif PC
#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();
error("Label declarations should precede const, type, var and routine declarations");
} else {
if ( !label_order ) {
label_order = TRUE;
warning();
error("Label declarations should precede const, type, var and routine declarations");
}
}
}
if (parts[ cbn ] & LPRT) {
if ( opt( 's' ) ) {
standard();
error("All labels should be declared in one label part");
} else {
if ( !label_seen ) {
label_seen = TRUE;
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->value[NL_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);
put(2, O_GOTO | cbn<<8, (long)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.
*/
extlabname( extname , p -> symbol , cbn );
putprintf(" .globl %s", 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;
#ifdef PC
char extname[ BUFSIZ ];
#endif PC
gocnt++;
p = lookup(s);
if (p == NIL)
return (NIL);
# ifdef OBJ
put(2, O_TRA4, (long)p->value[NL_ENTLOC]);
# endif OBJ
# ifdef PC
if ( cbn == bn ) {
/*
* local goto.
*/
extlabname( extname , p -> symbol , bn );
/*
* this is a funny jump because it's to a label that
* has been declared global.
* Although this branch is within this module
* the assembler will complain that the destination
* is a global symbol.
* The complaint arises because the assembler
* doesn't change relative jumps into absolute jumps.
* and this may cause a branch displacement overflow
* when the module is subsequently linked with
* the rest of the program.
*/
# ifdef vax
putprintf(" jmp %s", 0, extname);
# endif vax
# ifdef mc68000
putprintf(" jra %s", 0, extname);
# endif mc68000
} else {
/*
* Non-local goto.
*
* Close all active files between top of stack and
* frame at the destination level. Then call longjmp
* to unwind the stack to the destination level.
*
* For nested routines the end of the frame
* is calculated as:
* __disply[bn].fp + sizeof(local frame)
* (adjusted by (sizeof int) to get just past the end).
* The size of the local frame is dumped out by
* the second pass as an assembler constant.
* The main routine may not be compiled in this
* module, so its size may not be available.
* However all of its variables will be globally
* declared, so only the known runtime temporaries
* will be in its stack frame.
*/
parts[ bn ] |= NONLOCALGOTO;
putleaf( P2ICON , 0 , 0 , ADDTYPE( P2FTN | P2INT , P2PTR )
, "_PCLOSE" );
if ( bn > 1 ) {
p = lookup( enclosing[ bn - 1 ] );
sprintf( extname, "%s%d+%d",
FRAME_SIZE_LABEL, p -> value[NL_ENTLOC], sizeof(int));
p = lookup(s);
putLV( extname , bn , 0 , NNLOCAL , P2PTR | P2CHAR );
} else {
putLV( 0 , bn , -( DPOFF1 + sizeof( int ) ) , LOCALVAR ,
P2PTR | P2CHAR );
}
putop( P2CALL , P2INT );
putdot( filename , line );
putleaf( P2ICON , 0 , 0 , ADDTYPE( P2FTN | P2INT , P2PTR )
, "_longjmp" );
putLV( 0 , bn , GOTOENVOFFSET , NLOCAL , P2PTR|P2STRTY );
extlabname( extname , p -> symbol , bn );
putLV( extname , 0 , 0 , NGLOBAL , P2PTR|P2STRTY );
putop( P2LISTOP , P2INT );
putop( P2CALL , P2INT );
putdot( filename , line );
}
# 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;
#ifdef PC
char extname[ BUFSIZ ];
#endif PC
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->value[NL_ENTLOC]);
# endif OBJ
# ifdef PC
extlabname( extname , p -> symbol , bn );
putprintf( "%s:" , 0 , extname );
# 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
#ifdef PC
/*
* construct the long name of a label based on it's static nesting.
* into a caller-supplied buffer (that should be about BUFSIZ big).
*/
extlabname( buffer , name , level )
char buffer[];
char *name;
int level;
{
char *starthere;
int i;
starthere = &buffer[0];
for ( i = 1 ; i < level ; i++ ) {
sprintf( starthere , EXTFORMAT , enclosing[ i ] );
starthere += strlen( enclosing[ i ] ) + 1;
}
sprintf( starthere , EXTFORMAT , "" );
starthere += 1;
sprintf( starthere , LABELFORMAT , name );
starthere += strlen( name ) + 1;
if ( starthere >= &buffer[ BUFSIZ ] ) {
panic( "extlabname" );
}
}
#endif PC