1 /* $Id: mkpar.c,v 1.16 2019/11/04 01:23:02 tom Exp $ */
5 #define NotSuppressed(p) ((p)->suppressed == 0)
8 #define MaySuppress(p) ((backtrack ? ((p)->suppressed <= 1) : (p)->suppressed == 0))
9 /* suppress the preferred action => enable backtracking */
10 #define StartBacktrack(p) if (backtrack && (p) != NULL && NotSuppressed(p)) (p)->suppressed = 1
12 #define MaySuppress(p) ((p)->suppressed == 0)
13 #define StartBacktrack(p) /*nothing */
16 static action *add_reduce(action *actions, int ruleno, int symbol);
17 static action *add_reductions(int stateno, action *actions);
18 static action *get_shifts(int stateno);
19 static action *parse_actions(int stateno);
20 static int sole_reduction(int stateno);
21 static void defreds(void);
22 static void find_final_state(void);
23 static void free_action_row(action *p);
24 static void remove_conflicts(void);
25 static void total_conflicts(void);
26 static void unused_rules(void);
43 static Value_t SRcount;
44 static Value_t RRcount;
51 parser = NEW2(nstates, action *);
52 for (i = 0; i < nstates; i++)
53 parser[i] = parse_actions(i);
58 if (SRtotal + RRtotal > 0)
64 parse_actions(int stateno)
68 actions = get_shifts(stateno);
69 actions = add_reductions(stateno, actions);
74 get_shifts(int stateno)
76 action *actions, *temp;
83 sp = shift_table[stateno];
86 to_state2 = sp->shift;
87 for (i = (Value_t)(sp->nshifts - 1); i >= 0; i--)
90 symbol = accessing_symbol[k];
95 temp->symbol = symbol;
97 temp->prec = symbol_prec[symbol];
98 temp->action_code = SHIFT;
99 temp->assoc = symbol_assoc[symbol];
108 add_reductions(int stateno, action *actions)
111 int ruleno, tokensetsize;
114 tokensetsize = WORDSIZE(ntokens);
115 m = lookaheads[stateno];
116 n = lookaheads[stateno + 1];
117 for (i = m; i < n; i++)
119 ruleno = LAruleno[i];
120 rowp = LA + i * tokensetsize;
121 for (j = ntokens - 1; j >= 0; j--)
124 actions = add_reduce(actions, ruleno, j);
131 add_reduce(action *actions,
135 action *temp, *prev, *next;
138 for (next = actions; next && next->symbol < symbol; next = next->next)
141 while (next && next->symbol == symbol && next->action_code == SHIFT)
147 while (next && next->symbol == symbol &&
148 next->action_code == REDUCE && next->number < ruleno)
156 temp->symbol = (Value_t)symbol;
157 temp->number = (Value_t)ruleno;
158 temp->prec = rprec[ruleno];
159 temp->action_code = REDUCE;
160 temp->assoc = rassoc[ruleno];
171 find_final_state(void)
177 if ((p = shift_table[0]) != 0)
179 to_state2 = p->shift;
181 for (i = p->nshifts - 1; i >= 0; --i)
183 final_state = to_state2[i];
184 if (accessing_symbol[final_state] == goal)
196 rules_used = TMALLOC(Value_t, nrules);
197 NO_SPACE(rules_used);
199 for (i = 0; i < nrules; ++i)
202 for (i = 0; i < nstates; ++i)
204 for (p = parser[i]; p; p = p->next)
206 if ((p->action_code == REDUCE) && MaySuppress(p))
207 rules_used[p->number] = 1;
212 for (i = 3; i < nrules; ++i)
219 fprintf(stderr, "%s: 1 rule never reduced\n", myname);
221 fprintf(stderr, "%s: %d rules never reduced\n", myname, nunused);
226 remove_conflicts(void)
230 action *p, *pref = 0;
234 SRconflicts = NEW2(nstates, Value_t);
235 RRconflicts = NEW2(nstates, Value_t);
236 for (i = 0; i < nstates; i++)
241 #if defined(YYBTYACC)
244 for (p = parser[i]; p; p = p->next)
246 if (p->symbol != symbol)
248 /* the first parse action for each symbol is the preferred action */
252 /* following conditions handle multiple, i.e., conflicting, parse actions */
253 else if (i == final_state && symbol == 0)
257 StartBacktrack(pref);
259 else if (pref != 0 && pref->action_code == SHIFT)
261 if (pref->prec > 0 && p->prec > 0)
263 if (pref->prec < p->prec)
265 pref->suppressed = 2;
268 else if (pref->prec > p->prec)
272 else if (pref->assoc == LEFT)
274 pref->suppressed = 2;
277 else if (pref->assoc == RIGHT)
283 pref->suppressed = 2;
291 StartBacktrack(pref);
298 StartBacktrack(pref);
303 SRconflicts[i] = SRcount;
304 RRconflicts[i] = RRcount;
309 total_conflicts(void)
311 fprintf(stderr, "%s: ", myname);
313 fprintf(stderr, "1 shift/reduce conflict");
314 else if (SRtotal > 1)
315 fprintf(stderr, "%d shift/reduce conflicts", SRtotal);
317 if (SRtotal && RRtotal)
318 fprintf(stderr, ", ");
321 fprintf(stderr, "1 reduce/reduce conflict");
322 else if (RRtotal > 1)
323 fprintf(stderr, "%d reduce/reduce conflicts", RRtotal);
325 fprintf(stderr, ".\n");
327 if (SRexpect >= 0 && SRtotal != SRexpect)
329 fprintf(stderr, "%s: ", myname);
330 fprintf(stderr, "expected %d shift/reduce conflict%s.\n",
331 SRexpect, PLURAL(SRexpect));
332 exit_code = EXIT_FAILURE;
334 if (RRexpect >= 0 && RRtotal != RRexpect)
336 fprintf(stderr, "%s: ", myname);
337 fprintf(stderr, "expected %d reduce/reduce conflict%s.\n",
338 RRexpect, PLURAL(RRexpect));
339 exit_code = EXIT_FAILURE;
344 sole_reduction(int stateno)
351 for (p = parser[stateno]; p; p = p->next)
353 if (p->action_code == SHIFT && MaySuppress(p))
355 else if ((p->action_code == REDUCE) && MaySuppress(p))
357 if (ruleno > 0 && p->number != ruleno)
375 defred = NEW2(nstates, Value_t);
376 for (i = 0; i < nstates; i++)
377 defred[i] = (Value_t)sole_reduction(i);
381 free_action_row(action *p)
398 for (i = 0; i < nstates; i++)
399 free_action_row(parser[i]);
410 DO_FREE(SRconflicts);
411 DO_FREE(RRconflicts);