/***** spin: dstep.c *****/ /* Copyright (c) 1991,1995 by AT&T Corporation.  All Rights Reserved.     *//* This software is for educational purposes only.                        *//* Permission is given to distribute this code provided that this intro-  *//* ductory message is not removed and no monies are exchanged.            *//* No guarantee is expressed or implied by the distribution of this code. *//* Software written by Gerard J. Holzmann as part of the book:            *//* `Design and Validation of Computer Protocols,' ISBN 0-13-539925-4,     *//* Prentice Hall, Englewood Cliffs, NJ, 07632.                            *//* Send bug-reports and/or questions to: gerard@research.att.com          */ #include "spin.h"#include "y.tab.h" char	*NextLab[64];int	Level=0, GenCode=0, IsGuard=0, TestOnly=0;int	Tj=0, Jt=0, LastGoto=0;int	Tojump[512], Jumpto[512], Special[512]; voidSourced(int n, int special){	int i;	for (i = 0; i < Tj; i++)		if (Tojump[i] == n)			return;	Special[Tj] = special;	Tojump[Tj++] = n;} voidDested(int n){	int i; 	LastGoto = 1;	for (i = 0; i < Tj; i++)		if (Tojump[i] == n)			return;	for (i = 0; i < Jt; i++)		if (Jumpto[i] == n)			return;	Jumpto[Jt++] = n;} voidMopup(FILE *fd){	int i, j;	for (i = 0; i < Jt; i++)	{	for (j = 0; j < Tj; j++)		{	if (Tojump[j] == Jumpto[i])				break;		}		if (j == Tj)		{	char buf[12];			sprintf(buf, "S_%.3d_0", Jumpto[i]);			non_fatal("goto %s breaks from d_step seq", buf);	}	}	for (j = 0; j < Tj; j++)	{	for (i = 0; i < Jt; i++)		{	if (Tojump[j] == Jumpto[i])				break;		}#ifdef DEBUG		if (i == Jt && !Special[i])		{	fprintf(fd, "\t\t/* >>no goto's for S_%.3d_0<< */\n",			Tojump[j]);		}#endif	}	for (j = i = 0; j < Tj; j++)	{	if (Special[j])		{	Tojump[i] = Tojump[j];			Special[i] = 2;			i++;	}	}	Tj = i;	/* keep only the global exit-labels */	Jt = 0;} intFirstTime(int n){	int i;	for (i = 0; i < Tj; i++)		if (Tojump[i] == n)			return (Special[i] <= 1);	return 1;} voidillegal(Element *e, char *str){	printf("illegal operator in 'step:' '");	comment(stdout, e->n, 0);	printf("'\n");	fatal("saw %s", str);} voidfilterbad(Element *e){	switch (e->n->ntyp) {	case ASSERT:	case PRINT:	case 'c':		/* run cannot be completely undone		 * with sv_save-sv_restor		 */		if (any_oper(e->n->lft, RUN))			illegal(e, "run operator");		break;	case '@':		illegal(e, "process termination");		break;	case D_STEP:		illegal(e, "nested d_step sequence");		break;	case ATOMIC:		illegal(e, "nested atomic sequence");		break;	default:		break;	}} intCollectGuards(FILE *fd, Element *e, int inh){	SeqList *h; Element *ee; 	for (h = e->sub; h; h = h->nxt)	{	ee = huntstart(h->this->frst);		filterbad(ee);		switch (ee->n->ntyp) {		case  IF:			inh += CollectGuards(fd, ee, inh);			break;		case '.':			if (ee->nxt->n->ntyp == DO)				inh += CollectGuards(fd, ee->nxt, inh);			break;		case ELSE:			if (inh++ > 0) fprintf(fd, " || ");			fprintf(fd, "(1 /* else */)");			break;		case 'c':			if (inh++ > 0) fprintf(fd, " || ");			fprintf(fd, "("); TestOnly=1;			putstmnt(fd, ee->n->lft, e->seqno);			fprintf(fd, ")"); TestOnly=0;			break;		}	}	return inh;} intputcode(FILE *fd, Sequence *s, Element *nxt, int justguards){	int isg=0; 	NextLab[0] = "continue"; 	filterbad(s->frst); 	switch (s->frst->n->ntyp) {	case UNLESS:		non_fatal("'unless' inside d_step - ignored", (char *) 0);		return putcode(fd, s->frst->n->sl->this, nxt, 0);	case NON_ATOMIC:		(void) putcode(fd, s->frst->n->sl->this, ZE, 1);		break;	case IF:		fprintf(fd, "if (!(");		if (!CollectGuards(fd, s->frst, 0))			fprintf(fd, "1");		fprintf(fd, "))\n\t\t\tcontinue;");		isg = 1;		break;	case '.':		if (s->frst->nxt->n->ntyp == DO)		{	fprintf(fd, "if (!(");			if (!CollectGuards(fd, s->frst->nxt, 0))				fprintf(fd, "1");			fprintf(fd, "))\n\t\t\tcontinue;");			isg = 1;		}		break;	case 'R':	case 'r':	case 's':		fprintf(fd, "if (!("); TestOnly=1;		putstmnt(fd, s->frst->n, s->frst->seqno);		fprintf(fd, "))\n\t\t\tcontinue;"); TestOnly=0;		break;	case 'c':		fprintf(fd, "if (!("); TestOnly=1;		putstmnt(fd, s->frst->n->lft, s->frst->seqno);		fprintf(fd, "))\n\t\t\tcontinue;"); TestOnly=0;		break;	}	if (justguards) return 0; 	fprintf(fd, "\n#if defined(FULLSTACK) && defined(NOCOMP)\n");	fprintf(fd, "\t\tif (t->atom&2)\n");	fprintf(fd, "#endif\n");	fprintf(fd, "\t\tsv_save((char *)&now);\n");	putCode(fd, s->frst, s->extent, nxt, isg); 	if (nxt)	{	if (FirstTime(nxt->Seqno)		&& (!(nxt->status & DONE2) || !(nxt->status & D_ATOM)))		{	fprintf(fd, "S_%.3d_0: /* 1 */\n", nxt->Seqno);			nxt->status |= DONE2;			LastGoto = 0;		}		Sourced(nxt->Seqno, 1);		Mopup(fd);	}	unskip(s->frst->seqno);	return LastGoto;} voidputCode(FILE *fd, Element *f, Element *last, Element *next, int isguard){	Element *e, *N;	SeqList *h; int i;	char NextOpt[32]; 	for (e = f; e; e = e->nxt)	{	if (e->status & DONE2)			continue;		e->status |= DONE2; 		if (!(e->status & D_ATOM))		{	if (!LastGoto)			{	fprintf(fd, "\t\tgoto S_%.3d_0;\n", e->Seqno);				Dested(e->Seqno);			}			break;		}		fprintf(fd, "S_%.3d_0: /* 2 */\n", e->Seqno);		Sourced(e->Seqno, 0); 		if (!e->sub)		{	filterbad(e);			switch (e->n->ntyp) {			case NON_ATOMIC:				h = e->n->sl;				putCode(fd, h->this->frst, h->this->extent, e->nxt, 0);				break;			case BREAK:				if (LastGoto) break;				i = target(huntele(e->nxt, e->status))->Seqno;				fprintf(fd, "\t\tgoto S_%.3d_0;	/* 'break' */\n", i);				Dested(i);				break;			case GOTO:				if (LastGoto) break;				i = huntele(get_lab(e->n,1), e->status)->Seqno;				fprintf(fd, "\t\tgoto S_%.3d_0;	/* 'goto' */\n", i);				Dested(i);				break;			case '.':				if (LastGoto) break;				if (e->nxt->status & DONE2)				{	i = e->nxt?e->nxt->Seqno:0;					fprintf(fd, "\t\tgoto S_%.3d_0;	/* '.' */\n", i);					Dested(i);				}				break;			default:				putskip(e->seqno);				GenCode = 1; IsGuard = isguard;				fprintf(fd, "\t\t");				putstmnt(fd, e->n, e->seqno);				fprintf(fd, ";\n");				GenCode = IsGuard = isguard = LastGoto = 0;				if (e->n->ntyp == ELSE)					LastGoto = 1;				break;			}			i = e->nxt?e->nxt->Seqno:0;			if (e->nxt && e->nxt->status & DONE2 && !LastGoto)			{	fprintf(fd, "\t\tgoto S_%.3d_0; /* ';' */\n", i);				Dested(i);				break;			}		} else		{	for (h = e->sub, i=1; h; h = h->nxt, i++)			{	sprintf(NextOpt, "goto S_%.3d_%d", e->Seqno, i);				NextLab[++Level] = NextOpt;				N = (e->n->ntyp == DO) ? e : e->nxt;				putCode(fd, h->this->frst, h->this->extent, N, 1);				Level--;				fprintf(fd, "%s: /* 3 */\n", &NextOpt[5]);			}			if (!LastGoto)			{	fprintf(fd, "\t\tUerror(\"blocking sel in d_step\");\n");				LastGoto = 0;			}		}		if (e == last)		{	if (!LastGoto && next)			{	fprintf(fd, "\t\tgoto S_%.3d_0;\n", next->Seqno);				Dested(next->Seqno);			}			break;	}	}}