+++ /dev/null
-/***** spin: flow.c *****/
-
-/* Copyright (c) 1989-2003 by Lucent Technologies, Bell Laboratories. */
-/* All Rights Reserved. This software is for educational purposes only. */
-/* No guarantee whatsoever is expressed or implied by the distribution of */
-/* this code. Permission is given to distribute this code provided that */
-/* this introductory message is not removed and no monies are exchanged. */
-/* Software written by Gerard J. Holzmann. For tool documentation see: */
-/* http://spinroot.com/ */
-/* Send all bug-reports and/or questions to: bugs@spinroot.com */
-
-#include "spin.h"
-#include "y.tab.h"
-
-extern Symbol *Fname;
-extern int nr_errs, lineno, verbose;
-extern short has_unless, has_badelse;
-
-Element *Al_El = ZE;
-Label *labtab = (Label *) 0;
-int Unique=0, Elcnt=0, DstepStart = -1;
-
-static Lbreak *breakstack = (Lbreak *) 0;
-static Lextok *innermost;
-static SeqList *cur_s = (SeqList *) 0;
-static int break_id=0;
-
-static Element *if_seq(Lextok *);
-static Element *new_el(Lextok *);
-static Element *unless_seq(Lextok *);
-static void add_el(Element *, Sequence *);
-static void attach_escape(Sequence *, Sequence *);
-static void mov_lab(Symbol *, Element *, Element *);
-static void walk_atomic(Element *, Element *, int);
-
-void
-open_seq(int top)
-{ SeqList *t;
- Sequence *s = (Sequence *) emalloc(sizeof(Sequence));
-
- t = seqlist(s, cur_s);
- cur_s = t;
- if (top) Elcnt = 1;
-}
-
-void
-rem_Seq(void)
-{
- DstepStart = Unique;
-}
-
-void
-unrem_Seq(void)
-{
- DstepStart = -1;
-}
-
-static int
-Rjumpslocal(Element *q, Element *stop)
-{ Element *lb, *f;
- SeqList *h;
-
- /* allow no jumps out of a d_step sequence */
- for (f = q; f && f != stop; f = f->nxt)
- { if (f && f->n && f->n->ntyp == GOTO)
- { lb = get_lab(f->n, 0);
- if (!lb || lb->Seqno < DstepStart)
- { lineno = f->n->ln;
- Fname = f->n->fn;
- return 0;
- } }
- for (h = f->sub; h; h = h->nxt)
- { if (!Rjumpslocal(h->this->frst, h->this->last))
- return 0;
-
- } }
- return 1;
-}
-
-void
-cross_dsteps(Lextok *a, Lextok *b)
-{
- if (a && b
- && a->indstep != b->indstep)
- { lineno = a->ln;
- Fname = a->fn;
- fatal("jump into d_step sequence", (char *) 0);
- }
-}
-
-int
-is_skip(Lextok *n)
-{
- return (n->ntyp == PRINT
- || n->ntyp == PRINTM
- || (n->ntyp == 'c'
- && n->lft
- && n->lft->ntyp == CONST
- && n->lft->val == 1));
-}
-
-void
-check_sequence(Sequence *s)
-{ Element *e, *le = ZE;
- Lextok *n;
- int cnt = 0;
-
- for (e = s->frst; e; le = e, e = e->nxt)
- { n = e->n;
- if (is_skip(n) && !has_lab(e, 0))
- { cnt++;
- if (cnt > 1
- && n->ntyp != PRINT
- && n->ntyp != PRINTM)
- { if (verbose&32)
- printf("spin: line %d %s, redundant skip\n",
- n->ln, n->fn->name);
- if (e != s->frst
- && e != s->last
- && e != s->extent)
- { e->status |= DONE; /* not unreachable */
- le->nxt = e->nxt; /* remove it */
- e = le;
- }
- }
- } else
- cnt = 0;
- }
-}
-
-void
-prune_opts(Lextok *n)
-{ SeqList *l;
- extern Symbol *context;
- extern char *claimproc;
-
- if (!n
- || (context && claimproc && strcmp(context->name, claimproc) == 0))
- return;
-
- for (l = n->sl; l; l = l->nxt) /* find sequences of unlabeled skips */
- check_sequence(l->this);
-}
-
-Sequence *
-close_seq(int nottop)
-{ Sequence *s = cur_s->this;
- Symbol *z;
-
- if (nottop > 0 && (z = has_lab(s->frst, 0)))
- { printf("error: (%s:%d) label %s placed incorrectly\n",
- (s->frst->n)?s->frst->n->fn->name:"-",
- (s->frst->n)?s->frst->n->ln:0,
- z->name);
- switch (nottop) {
- case 1:
- printf("=====> stmnt unless Label: stmnt\n");
- printf("sorry, cannot jump to the guard of an\n");
- printf("escape (it is not a unique state)\n");
- break;
- case 2:
- printf("=====> instead of ");
- printf("\"Label: stmnt unless stmnt\"\n");
- printf("=====> always use ");
- printf("\"Label: { stmnt unless stmnt }\"\n");
- break;
- case 3:
- printf("=====> instead of ");
- printf("\"atomic { Label: statement ... }\"\n");
- printf("=====> always use ");
- printf("\"Label: atomic { statement ... }\"\n");
- break;
- case 4:
- printf("=====> instead of ");
- printf("\"d_step { Label: statement ... }\"\n");
- printf("=====> always use ");
- printf("\"Label: d_step { statement ... }\"\n");
- break;
- case 5:
- printf("=====> instead of ");
- printf("\"{ Label: statement ... }\"\n");
- printf("=====> always use ");
- printf("\"Label: { statement ... }\"\n");
- break;
- case 6:
- printf("=====>instead of\n");
- printf(" do (or if)\n");
- printf(" :: ...\n");
- printf(" :: Label: statement\n");
- printf(" od (of fi)\n");
- printf("=====>always use\n");
- printf("Label: do (or if)\n");
- printf(" :: ...\n");
- printf(" :: statement\n");
- printf(" od (or fi)\n");
- break;
- case 7:
- printf("cannot happen - labels\n");
- break;
- }
- alldone(1);
- }
-
- if (nottop == 4
- && !Rjumpslocal(s->frst, s->last))
- fatal("non_local jump in d_step sequence", (char *) 0);
-
- cur_s = cur_s->nxt;
- s->maxel = Elcnt;
- s->extent = s->last;
- if (!s->last)
- fatal("sequence must have at least one statement", (char *) 0);
- return s;
-}
-
-Lextok *
-do_unless(Lextok *No, Lextok *Es)
-{ SeqList *Sl;
- Lextok *Re = nn(ZN, UNLESS, ZN, ZN);
- Re->ln = No->ln;
- Re->fn = No->fn;
-
- has_unless++;
- if (Es->ntyp == NON_ATOMIC)
- Sl = Es->sl;
- else
- { open_seq(0); add_seq(Es);
- Sl = seqlist(close_seq(1), 0);
- }
-
- if (No->ntyp == NON_ATOMIC)
- { No->sl->nxt = Sl;
- Sl = No->sl;
- } else if (No->ntyp == ':'
- && (No->lft->ntyp == NON_ATOMIC
- || No->lft->ntyp == ATOMIC
- || No->lft->ntyp == D_STEP))
- {
- int tok = No->lft->ntyp;
-
- No->lft->sl->nxt = Sl;
- Re->sl = No->lft->sl;
-
- open_seq(0); add_seq(Re);
- Re = nn(ZN, tok, ZN, ZN);
- Re->sl = seqlist(close_seq(7), 0);
- Re->ln = No->ln;
- Re->fn = No->fn;
-
- Re = nn(No, ':', Re, ZN); /* lift label */
- Re->ln = No->ln;
- Re->fn = No->fn;
- return Re;
- } else
- { open_seq(0); add_seq(No);
- Sl = seqlist(close_seq(2), Sl);
- }
-
- Re->sl = Sl;
- return Re;
-}
-
-SeqList *
-seqlist(Sequence *s, SeqList *r)
-{ SeqList *t = (SeqList *) emalloc(sizeof(SeqList));
-
- t->this = s;
- t->nxt = r;
- return t;
-}
-
-static Element *
-new_el(Lextok *n)
-{ Element *m;
-
- if (n)
- { if (n->ntyp == IF || n->ntyp == DO)
- return if_seq(n);
- if (n->ntyp == UNLESS)
- return unless_seq(n);
- }
- m = (Element *) emalloc(sizeof(Element));
- m->n = n;
- m->seqno = Elcnt++;
- m->Seqno = Unique++;
- m->Nxt = Al_El; Al_El = m;
- return m;
-}
-
-static int
-has_chanref(Lextok *n)
-{
- if (!n) return 0;
-
- switch (n->ntyp) {
- case 's': case 'r':
-#if 0
- case 'R': case LEN:
-#endif
- case FULL: case NFULL:
- case EMPTY: case NEMPTY:
- return 1;
- default:
- break;
- }
- if (has_chanref(n->lft))
- return 1;
-
- return has_chanref(n->rgt);
-}
-
-void
-loose_ends(void) /* properly tie-up ends of sub-sequences */
-{ Element *e, *f;
-
- for (e = Al_El; e; e = e->Nxt)
- { if (!e->n
- || !e->nxt)
- continue;
- switch (e->n->ntyp) {
- case ATOMIC:
- case NON_ATOMIC:
- case D_STEP:
- f = e->nxt;
- while (f && f->n->ntyp == '.')
- f = f->nxt;
- if (0) printf("link %d, {%d .. %d} -> %d (ntyp=%d) was %d\n",
- e->seqno,
- e->n->sl->this->frst->seqno,
- e->n->sl->this->last->seqno,
- f?f->seqno:-1, f?f->n->ntyp:-1,
- e->n->sl->this->last->nxt?e->n->sl->this->last->nxt->seqno:-1);
- if (!e->n->sl->this->last->nxt)
- e->n->sl->this->last->nxt = f;
- else
- { if (e->n->sl->this->last->nxt->n->ntyp != GOTO)
- { if (!f || e->n->sl->this->last->nxt->seqno != f->seqno)
- non_fatal("unexpected: loose ends", (char *)0);
- } else
- e->n->sl->this->last = e->n->sl->this->last->nxt;
- /*
- * fix_dest can push a goto into the nxt position
- * in that case the goto wins and f is not needed
- * but the last fields needs adjusting
- */
- }
- break;
- } }
-}
-
-static Element *
-if_seq(Lextok *n)
-{ int tok = n->ntyp;
- SeqList *s = n->sl;
- Element *e = new_el(ZN);
- Element *t = new_el(nn(ZN,'.',ZN,ZN)); /* target */
- SeqList *z, *prev_z = (SeqList *) 0;
- SeqList *move_else = (SeqList *) 0; /* to end of optionlist */
- int ref_chans = 0;
-
- for (z = s; z; z = z->nxt)
- { if (!z->this->frst)
- continue;
- if (z->this->frst->n->ntyp == ELSE)
- { if (move_else)
- fatal("duplicate `else'", (char *) 0);
- if (z->nxt) /* is not already at the end */
- { move_else = z;
- if (prev_z)
- prev_z->nxt = z->nxt;
- else
- s = n->sl = z->nxt;
- continue;
- }
- } else
- ref_chans |= has_chanref(z->this->frst->n);
- prev_z = z;
- }
- if (move_else)
- { move_else->nxt = (SeqList *) 0;
- /* if there is no prev, then else was at the end */
- if (!prev_z) fatal("cannot happen - if_seq", (char *) 0);
- prev_z->nxt = move_else;
- prev_z = move_else;
- }
- if (prev_z
- && ref_chans
- && prev_z->this->frst->n->ntyp == ELSE)
- { prev_z->this->frst->n->val = 1;
- has_badelse++;
- non_fatal("dubious use of 'else' combined with i/o,",
- (char *)0);
- nr_errs--;
- }
-
- e->n = nn(n, tok, ZN, ZN);
- e->n->sl = s; /* preserve as info only */
- e->sub = s;
- for (z = s; z; prev_z = z, z = z->nxt)
- add_el(t, z->this); /* append target */
- if (tok == DO)
- { add_el(t, cur_s->this); /* target upfront */
- t = new_el(nn(n, BREAK, ZN, ZN)); /* break target */
- set_lab(break_dest(), t); /* new exit */
- breakstack = breakstack->nxt; /* pop stack */
- }
- add_el(e, cur_s->this);
- add_el(t, cur_s->this);
- return e; /* destination node for label */
-}
-
-static void
-escape_el(Element *f, Sequence *e)
-{ SeqList *z;
-
- for (z = f->esc; z; z = z->nxt)
- if (z->this == e)
- return; /* already there */
-
- /* cover the lower-level escapes of this state */
- for (z = f->esc; z; z = z->nxt)
- attach_escape(z->this, e);
-
- /* now attach escape to the state itself */
-
- f->esc = seqlist(e, f->esc); /* in lifo order... */
-#ifdef DEBUG
- printf("attach %d (", e->frst->Seqno);
- comment(stdout, e->frst->n, 0);
- printf(") to %d (", f->Seqno);
- comment(stdout, f->n, 0);
- printf(")\n");
-#endif
- switch (f->n->ntyp) {
- case UNLESS:
- attach_escape(f->sub->this, e);
- break;
- case IF:
- case DO:
- for (z = f->sub; z; z = z->nxt)
- attach_escape(z->this, e);
- break;
- case D_STEP:
- /* attach only to the guard stmnt */
- escape_el(f->n->sl->this->frst, e);
- break;
- case ATOMIC:
- case NON_ATOMIC:
- /* attach to all stmnts */
- attach_escape(f->n->sl->this, e);
- break;
- }
-}
-
-static void
-attach_escape(Sequence *n, Sequence *e)
-{ Element *f;
-
- for (f = n->frst; f; f = f->nxt)
- { escape_el(f, e);
- if (f == n->extent)
- break;
- }
-}
-
-static Element *
-unless_seq(Lextok *n)
-{ SeqList *s = n->sl;
- Element *e = new_el(ZN);
- Element *t = new_el(nn(ZN,'.',ZN,ZN)); /* target */
- SeqList *z;
-
- e->n = nn(n, UNLESS, ZN, ZN);
- e->n->sl = s; /* info only */
- e->sub = s;
-
- /* need 2 sequences: normal execution and escape */
- if (!s || !s->nxt || s->nxt->nxt)
- fatal("unexpected unless structure", (char *)0);
-
- /* append the target state to both */
- for (z = s; z; z = z->nxt)
- add_el(t, z->this);
-
- /* attach escapes to all states in normal sequence */
- attach_escape(s->this, s->nxt->this);
-
- add_el(e, cur_s->this);
- add_el(t, cur_s->this);
-#ifdef DEBUG
- printf("unless element (%d,%d):\n", e->Seqno, t->Seqno);
- for (z = s; z; z = z->nxt)
- { Element *x; printf("\t%d,%d,%d :: ",
- z->this->frst->Seqno,
- z->this->extent->Seqno,
- z->this->last->Seqno);
- for (x = z->this->frst; x; x = x->nxt)
- printf("(%d)", x->Seqno);
- printf("\n");
- }
-#endif
- return e;
-}
-
-Element *
-mk_skip(void)
-{ Lextok *t = nn(ZN, CONST, ZN, ZN);
- t->val = 1;
- return new_el(nn(ZN, 'c', t, ZN));
-}
-
-static void
-add_el(Element *e, Sequence *s)
-{
- if (e->n->ntyp == GOTO)
- { Symbol *z = has_lab(e, (1|2|4));
- if (z)
- { Element *y; /* insert a skip */
- y = mk_skip();
- mov_lab(z, e, y); /* inherit label */
- add_el(y, s);
- } }
-#ifdef DEBUG
- printf("add_el %d after %d -- ",
- e->Seqno, (s->last)?s->last->Seqno:-1);
- comment(stdout, e->n, 0);
- printf("\n");
-#endif
- if (!s->frst)
- s->frst = e;
- else
- s->last->nxt = e;
- s->last = e;
-}
-
-static Element *
-colons(Lextok *n)
-{
- if (!n)
- return ZE;
- if (n->ntyp == ':')
- { Element *e = colons(n->lft);
- set_lab(n->sym, e);
- return e;
- }
- innermost = n;
- return new_el(n);
-}
-
-void
-add_seq(Lextok *n)
-{ Element *e;
-
- if (!n) return;
- innermost = n;
- e = colons(n);
- if (innermost->ntyp != IF
- && innermost->ntyp != DO
- && innermost->ntyp != UNLESS)
- add_el(e, cur_s->this);
-}
-
-void
-set_lab(Symbol *s, Element *e)
-{ Label *l; extern Symbol *context;
-
- if (!s) return;
- for (l = labtab; l; l = l->nxt)
- if (l->s == s && l->c == context)
- { non_fatal("label %s redeclared", s->name);
- break;
- }
- l = (Label *) emalloc(sizeof(Label));
- l->s = s;
- l->c = context;
- l->e = e;
- l->nxt = labtab;
- labtab = l;
-}
-
-Element *
-get_lab(Lextok *n, int md)
-{ Label *l;
- Symbol *s = n->sym;
-
- for (l = labtab; l; l = l->nxt)
- if (s == l->s)
- return (l->e);
-
- lineno = n->ln;
- Fname = n->fn;
- if (md) fatal("undefined label %s", s->name);
- return ZE;
-}
-
-Symbol *
-has_lab(Element *e, int special)
-{ Label *l;
-
- for (l = labtab; l; l = l->nxt)
- { if (e != l->e)
- continue;
- if (special == 0
- || ((special&1) && !strncmp(l->s->name, "accept", 6))
- || ((special&2) && !strncmp(l->s->name, "end", 3))
- || ((special&4) && !strncmp(l->s->name, "progress", 8)))
- return (l->s);
- }
- return ZS;
-}
-
-static void
-mov_lab(Symbol *z, Element *e, Element *y)
-{ Label *l;
-
- for (l = labtab; l; l = l->nxt)
- if (e == l->e)
- { l->e = y;
- return;
- }
- if (e->n)
- { lineno = e->n->ln;
- Fname = e->n->fn;
- }
- fatal("cannot happen - mov_lab %s", z->name);
-}
-
-void
-fix_dest(Symbol *c, Symbol *a) /* c:label name, a:proctype name */
-{ Label *l; extern Symbol *context;
-
-#if 0
- printf("ref to label '%s' in proctype '%s', search:\n",
- c->name, a->name);
- for (l = labtab; l; l = l->nxt)
- printf(" %s in %s\n", l->s->name, l->c->name);
-#endif
-
- for (l = labtab; l; l = l->nxt)
- { if (strcmp(c->name, l->s->name) == 0
- && strcmp(a->name, l->c->name) == 0) /* ? */
- break;
- }
- if (!l)
- { printf("spin: label '%s' (proctype %s)\n", c->name, a->name);
- non_fatal("unknown label '%s'", c->name);
- if (context == a)
- printf("spin: cannot remote ref a label inside the same proctype\n");
- return;
- }
- if (!l->e || !l->e->n)
- fatal("fix_dest error (%s)", c->name);
- if (l->e->n->ntyp == GOTO)
- { Element *y = (Element *) emalloc(sizeof(Element));
- int keep_ln = l->e->n->ln;
- Symbol *keep_fn = l->e->n->fn;
-
- /* insert skip - or target is optimized away */
- y->n = l->e->n; /* copy of the goto */
- y->seqno = find_maxel(a); /* unique seqno within proc */
- y->nxt = l->e->nxt;
- y->Seqno = Unique++; y->Nxt = Al_El; Al_El = y;
-
- /* turn the original element+seqno into a skip */
- l->e->n = nn(ZN, 'c', nn(ZN, CONST, ZN, ZN), ZN);
- l->e->n->ln = l->e->n->lft->ln = keep_ln;
- l->e->n->fn = l->e->n->lft->fn = keep_fn;
- l->e->n->lft->val = 1;
- l->e->nxt = y; /* append the goto */
- }
- l->e->status |= CHECK2; /* treat as if global */
- if (l->e->status & (ATOM | L_ATOM | D_ATOM))
- { non_fatal("cannot reference label inside atomic or d_step (%s)",
- c->name);
- }
-}
-
-int
-find_lab(Symbol *s, Symbol *c, int markit)
-{ Label *l;
-
- for (l = labtab; l; l = l->nxt)
- { if (strcmp(s->name, l->s->name) == 0
- && strcmp(c->name, l->c->name) == 0)
- { l->visible |= markit;
- return (l->e->seqno);
- } }
- return 0;
-}
-
-void
-pushbreak(void)
-{ Lbreak *r = (Lbreak *) emalloc(sizeof(Lbreak));
- Symbol *l;
- char buf[64];
-
- sprintf(buf, ":b%d", break_id++);
- l = lookup(buf);
- r->l = l;
- r->nxt = breakstack;
- breakstack = r;
-}
-
-Symbol *
-break_dest(void)
-{
- if (!breakstack)
- fatal("misplaced break statement", (char *)0);
- return breakstack->l;
-}
-
-void
-make_atomic(Sequence *s, int added)
-{ Element *f;
-
- walk_atomic(s->frst, s->last, added);
-
- f = s->last;
- switch (f->n->ntyp) { /* is last step basic stmnt or sequence ? */
- case NON_ATOMIC:
- case ATOMIC:
- /* redo and search for the last step of that sequence */
- make_atomic(f->n->sl->this, added);
- break;
-
- case UNLESS:
- /* escapes are folded into main sequence */
- make_atomic(f->sub->this, added);
- break;
-
- default:
- f->status &= ~ATOM;
- f->status |= L_ATOM;
- break;
- }
-}
-
-static void
-walk_atomic(Element *a, Element *b, int added)
-{ Element *f; Symbol *ofn; int oln;
- SeqList *h;
-
- ofn = Fname;
- oln = lineno;
- for (f = a; ; f = f->nxt)
- { f->status |= (ATOM|added);
- switch (f->n->ntyp) {
- case ATOMIC:
- if (verbose&32)
- printf("spin: warning, line %3d %s, atomic inside %s (ignored)\n",
- f->n->ln, f->n->fn->name, (added)?"d_step":"atomic");
- goto mknonat;
- case D_STEP:
- if (!(verbose&32))
- { if (added) goto mknonat;
- break;
- }
- printf("spin: warning, line %3d %s, d_step inside ",
- f->n->ln, f->n->fn->name);
- if (added)
- { printf("d_step (ignored)\n");
- goto mknonat;
- }
- printf("atomic\n");
- break;
- case NON_ATOMIC:
-mknonat: f->n->ntyp = NON_ATOMIC; /* can jump here */
- h = f->n->sl;
- walk_atomic(h->this->frst, h->this->last, added);
- break;
- case UNLESS:
- if (added)
- { printf("spin: error, line %3d %s, unless in d_step (ignored)\n",
- f->n->ln, f->n->fn->name);
- }
- }
- for (h = f->sub; h; h = h->nxt)
- walk_atomic(h->this->frst, h->this->last, added);
- if (f == b)
- break;
- }
- Fname = ofn;
- lineno = oln;
-}
-
-void
-dumplabels(void)
-{ Label *l;
-
- for (l = labtab; l; l = l->nxt)
- if (l->c != 0 && l->s->name[0] != ':')
- printf("label %s %d <%s>\n",
- l->s->name, l->e->seqno, l->c->name);
-}
projects / lttv.git / blobdiff