pftn.c

<B>Digital的Unix操作系统VAX 4.2源码</B>

#ifndef lint
static	char	*sccsid = "@(#)pftn.c	4.1	(ULTRIX)	11/23/87";
#endif lint
/************************************************************************
 *
 *			Modification History
 *
 *	@(#)pftn.c	1.3 (Berkeley) 7/15/83
 *
 *	David Metsky, 2-Jul-87
 * 012-	Fixed up types() so it can handle DOUBLE as a type that needs
 *	to be merged with const and volatile.
 *
 *	Victoria Holt, 14-Apr-86
 * 011- Bug fix for constant pointers.
 *
 * 	Lu Anne Van de Pas, 02-Mar-86
 * 010- Added support from intializing f floating constants
 *
 *	Victoria Holt, 26-Feb-86
 * 009- Added support for const and volatile.
 *
 *	Rich Phillips, 14-Sep-84
 * 008- I put the "if" in the wrong place for fix 6. It should go at
 *	the end of the switch, not after the default case.
 *
 *	Rich Phillips,  13-Sep-84
 * 007- Back out of fix 004, see mod history in local.c for reason.
 *
 *	Rich Phillips,  07-Sep-84
 * 006- Fix change 003 so previous symbol table entries are not removed
 *	causing "undefined" errors in later function definitions.
 *
 *	Rich Phillips,  31-Jul-84
 * 005- Issue a warning if the user redeclares a function argument at
 *	level 2.
 *
 *	Rich Phillips,  20-Jul-84
 * 004- Set SWASREG flag in the symbol table if a name was defined 
 *	with REGISTER, but changed by the compiler.
 *
 * 	Rich Phillips,  16-Jul-84
 * 003- Issue an error when an arguement is defined but not in the arguement
 *	list of the function def. It wasn't being caught when the name was used
 *	previously for something else that is still accessable.
 *
 *	Stephen Reilly, 16-Dec-83
 * 002- Give errors if we no that we can not do initialization
 *
 *	Stephen Reilly, 07-Dec-83
 * 001- Fix problem when formal parameters are structures that
 *	sre not aligned properly on the stack
 *
 ***********************************************************************/

/************************************************************************
 *									*
 *			Copyright (c) 1983 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

# include "mfile1"

unsigned int offsz;

struct instk {
	int in_sz;   /* size of array element */
	int in_x;    /* current index for structure member in structure initializations */
	int in_n;    /* number of initializations seen */
	int in_s;    /* sizoff */
	int in_d;    /* dimoff */
	TWORD in_t;    /* type */
	int in_id;   /* stab index */
	int in_fl;   /* flag which says if this level is controlled by {} */
	OFFSZ in_off;  /* offset of the beginning of this level */
	}
instack[10],
*pstk;

	/* defines used for getting things off of the initialization stack */


struct symtab *relook();


int ddebug = 0;

struct symtab * mknonuniq();

defid( q, class )  NODE *q; {
	register struct symtab *p;
	int idp;
	TWORD type, typattr, stattr;
	TWORD stp;
	int scl;
	int dsym, ddef;
	int slev, temp;
	int changed;

	if( q == NIL ) return;  /* an error was detected */

	if( q < node || q >= &node[TREESZ] ) cerror( "defid call" );

	idp = q->tn.rval;

	if( idp < 0 ) cerror( "tyreduce" );
	p = &stab[idp];

# ifndef BUG1
	if( ddebug ){
#ifndef FLEXNAMES
		printf( "defid( %.8s (%d), ", p->sname, idp );
#else
		printf( "defid( %s (%d), ", p->sname, idp );
#endif
		tprint( q->in.type );
		printf( ", %s, (%d,%d) ), level %d\n", scnames(class), q->fn.cdim, q->fn.csiz, blevel );
		}
# endif

	fixtype( q, class );

	type = q->in.type;
	typattr = q->in.typattr;
	class = fixclass( class, type );

	stp = p->stype;
	slev = p->slevel;
	stattr = p->stypattr;

# ifndef BUG1
	if( ddebug ){
		printf( "	modified to " );
		tprint( type );
		printf( ", %s\n", scnames(class) );
		printf( "	previous def'n: " );
		tprint( stp );
		printf( ", %s, (%d,%d) ), level %d\n", scnames(p->sclass), p->dimoff, p->sizoff, slev );
		}
# endif

	if( stp == FTN && p->sclass == SNULL )goto enter;
		/* name encountered as function, not yet defined */


	/*
		RAP003
		The logic of the following "if" was changed to catch the case
		where we are at level 1 and the previous use of the name is
		not FARG or  UNDEF. An external for example.
	*/
	if( blevel == 1 ){
		if( stp!=FARG ) switch( class ){

		default:
		
#ifndef FLEXNAMES
			if(!(class&FIELD)) uerror( "declared argument %.8s is missing", p->sname );
#else
			if(!(class&FIELD)) uerror( "declared argument %s is missing", p->sname );
#endif
		case MOS:
		case STNAME:
		case MOU:
		case UNAME:
		case MOE:
		case ENAME:
		case TYPEDEF:
			if (stp!=UNDEF)
				goto mayhide; /*RAP006 RAP008*/
			;
			}
		goto enter;
		} else if ( stp == UNDEF || stp == FARG ) goto enter;
 mayhide:
	if( type != stp ) goto mismatch;
	if (typattr != stattr) goto mismatch;
	/* test (and possibly adjust) dimensions */
	dsym = p->dimoff;
	ddef = q->fn.cdim;
	changed = 0;
	for( temp=type; temp&TMASK; temp = DECREF(temp) ){
		if( ISARY(temp) ){
			if (dimtab[dsym] == 0) {
				dimtab[dsym] = dimtab[ddef];
				changed = 1;
				}
			else if (dimtab[ddef]!=0&&dimtab[dsym]!=dimtab[ddef]) {
				goto mismatch;
				}
			++dsym;
			++ddef;
			}
		}

	if (changed) {
		FIXDEF(p);
		}

	/* check that redeclarations are to the same structure */
	if( (temp==STRTY||temp==UNIONTY||temp==ENUMTY) && p->sizoff != q->fn.csiz
		 && class!=STNAME && class!=UNAME && class!=ENAME ){
		goto mismatch;
		}

	scl = ( p->sclass );

# ifndef BUG1
	if( ddebug ){
		printf( "	previous class: %s\n", scnames(scl) );
		}
# endif

	if( class&FIELD ){
		/* redefinition */
		if( !falloc( p, class&FLDSIZ, 1, NIL ) ) {
			/* successful allocation */
			psave( idp );
			return;
			}
		/* blew it: resume at end of switch... */
		}

	else switch( class ){

	case EXTERN:
		switch( scl ){
		case STATIC:
		case USTATIC:
			if( slev==0 ) return;
			break;
		case EXTDEF:
		case EXTERN:
		case FORTRAN:
		case UFORTRAN:
			return;
			}
		break;

	case STATIC:
		if( scl==USTATIC || (scl==EXTERN && blevel==0) ){
			p->sclass = STATIC;
			if( ISFTN(type) ) curftn = idp;
			return;
			}
		break;

	case USTATIC:
		if( scl==STATIC || scl==USTATIC ) return;
		break;

	case LABEL:
		if( scl == ULABEL ){
			p->sclass = LABEL;
			deflab( p->offset );
			return;
			}
		break;

	case TYPEDEF:
		if( scl == class ) return;
		break;

	case UFORTRAN:
		if( scl == UFORTRAN || scl == FORTRAN ) return;
		break;

	case FORTRAN:
		if( scl == UFORTRAN ){
			p->sclass = FORTRAN;
			if( ISFTN(type) ) curftn = idp;
			return;
			}
		break;

	case MOU:
	case MOS:
		if( scl == class ) {
			if( oalloc( p, &strucoff ) ) break;
			if( class == MOU ) strucoff = 0;
			psave( idp );
			return;
			}
		break;

	case MOE:
		if( scl == class ){
			if( p->offset!= strucoff++ ) break;
			psave( idp );
			}
		break;

	case EXTDEF:
		if( scl == EXTERN ) {
			p->sclass = EXTDEF;
			if( ISFTN(type) ) curftn = idp;
			return;
			}
		break;

	case STNAME:
	case UNAME:
	case ENAME:
		if( scl != class ) break;
		if( dimtab[p->sizoff] == 0 ) return;  /* previous entry just a mention */
		break;

	case ULABEL:
		if( scl == LABEL || scl == ULABEL ) return;
	case PARAM:
	case AUTO:
	case REGISTER:
		;  /* mismatch.. */

		}

	mismatch:
	/* allow nonunique structure/union member names */

	if( class==MOU || class==MOS || class & FIELD ){/* make a new entry */
		int * memp;
		p->sflags |= SNONUNIQ;  /* old entry is nonunique */
		/* determine if name has occurred in this structure/union */
		for( memp = &paramstk[paramno-1];
			/* while */ *memp>=0 && stab[*memp].sclass != STNAME
				&& stab[*memp].sclass != UNAME;
			/* iterate */ --memp){ char * cname, * oname;
			if( stab[*memp].sflags & SNONUNIQ ){int k;
				cname=p->sname;
				oname=stab[*memp].sname;
#ifndef FLEXNAMES
				for(k=1; k<=NCHNAM; ++k){
					if(*cname++ != *oname)goto diff;
					if(!*oname++)break;
					}
#else
				if (cname != oname) goto diff;
#endif
				uerror("redeclaration of: %s",p->sname);
				break;
				diff: continue;
				}
			}
		p = mknonuniq( &idp ); /* update p and idp to new entry */
		goto enter;
		}
	if( blevel > slev && class != EXTERN && class != FORTRAN &&
		class != UFORTRAN && !( class == LABEL && slev >= 2 ) ){
		/*RAP005
			Issue a warning if a function paramater has just
			been redeclared first thing in the function.

			sub(a) int a;
			{
				int a;
			}
		*/
		if (slev==1 && blevel==2)
#ifndef FLEXNAMES
			werror("immediate redeclaration of argument: %.8s",
				p->sname);
#else
			werror("immediate redeclaration of argument: %s",
				p->sname);
#endif
		q->tn.rval = idp = hide( p );
		p = &stab[idp];
		goto enter;
		}
#ifndef FLEXNAMES
	uerror( "redeclaration of %.8s", p->sname );
#else
	uerror( "redeclaration of %s", p->sname );
#endif
	if( class==EXTDEF && ISFTN(type) ) curftn = idp;
	return;

	enter:  /* make a new entry */

# ifndef BUG1
	if( ddebug ) printf( "	new entry made\n" );
# endif
	if( type == UNDEF ) uerror("void type for %s",p->sname);
	p->stype = type;
	p->stypattr = typattr;
	p->sclass = class;
	p->slevel = blevel;
	p->offset = NOOFFSET;
	p->suse = lineno;
	if( class == STNAME || class == UNAME || class == ENAME ) {
		p->sizoff = curdim;
		dstash( 0 );  /* size */
		dstash( -1 ); /* index to members of str or union */
		dstash( ALSTRUCT );  /* alignment */
		dstash( idp );
		}
	else {
		switch( BTYPE(type) ){
		case STRTY:
		case UNIONTY:
		case ENUMTY:
			p->sizoff = q->fn.csiz;
			break;
		default:
			p->sizoff = BTYPE(type);
			}
		}

	/* copy dimensions */

	p->dimoff = q->fn.cdim;

	/* allocate offsets */
	if( class&FIELD ){
		falloc( p, class&FLDSIZ, 0, NIL );  /* new entry */
		psave( idp );
		}
	else switch( class ){

	case AUTO:
		oalloc( p, &autooff );
		break;
	case STATIC:
	case EXTDEF:
		p->offset = getlab();
		if( ISFTN(type) ) curftn = idp;
		break;
	case ULABEL:
	case LABEL:
		p->offset = getlab();
		p->slevel = 2;
		if( class == LABEL ){
			locctr( PROG );
			deflab( p->offset );
			}
		break;

	case EXTERN:
	case UFORTRAN:
	case FORTRAN:
		p->offset = getlab();
		p->slevel = 0;
		break;
	case MOU:
	case MOS:
		oalloc( p, &strucoff );
		if( class == MOU ) strucoff = 0;
		psave( idp );
		break;

	case MOE:
		p->offset = strucoff++;
		psave( idp );
		break;
	case REGISTER:
		p->offset = regvar--;
		if( blevel == 1 ) p->sflags |= SSET;
		if( regvar < minrvar ) minrvar = regvar;
		break;
		}

	/* user-supplied routine to fix up new definitions */

	FIXDEF(p);

# ifndef BUG1
	if( ddebug ) printf( "	dimoff, sizoff, offset: %d, %d, %d\n", p->dimoff, p->sizoff, p->offset );
# endif

	}

psave( i ){
	if( paramno >= PARAMSZ ){
		cerror( "parameter stack overflow");
		}
	paramstk[ paramno++ ] = i;
	}

ftnend(){ /* end of function */
	if( retlab != NOLAB ){ /* inside a real function */
		efcode();
		}
	checkst(0);
	retstat = 0;
	tcheck();
	curclass = SNULL;
	brklab = contlab = retlab = NOLAB;
	flostat = 0;
	if( nerrors == 0 ){
		if( psavbc != & asavbc[0] ) cerror("bcsave error");
		if( paramno != 0 ) cerror("parameter reset error");
		if( swx != 0 ) cerror( "switch error");
		}
	psavbc = &asavbc[0];
	paramno = 0;
	autooff = AUTOINIT;
	minrvar = regvar = MAXRVAR;
	reached = 1;
	swx = 0;
	swp = swtab;
	locctr(DATA);
	}

dclargs(){
	register i, j;
	register struct symtab *p;
	register NODE *q;
	argoff = ARGINIT;
# ifndef BUG1
	if( ddebug > 2) printf("dclargs()\n");
# endif
	for( i=0; i<paramno; ++i ){
		if( (j = paramstk[i]) < 0 ) continue;
		p = &stab[j];
# ifndef BUG1
		if( ddebug > 2 ){
			printf("\t%s (%d) ",p->sname, j);
			tprint(p->stype);
			printf("\n");
			}
# endif
		if( p->stype == FARG ) {
			q = block(FREE,NIL,NIL,INT,0,INT);
			q->tn.rval = j;
			q->in.typattr = p->stypattr;
			defid( q, PARAM );
			}
		FIXARG(p); /* local arg hook, eg. for sym. debugger */
		oalloc( p, &argoff );  /* always set aside space, even for register arguments */
 		if( p->stype==STRTY || p->stype==UNIONTY )