1 /* $Id: mkpar.c,v 1.14 2014/04/01 23:05:37 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)
178 to_state2 = p->shift;
180 for (i = p->nshifts - 1; i >= 0; --i)
182 final_state = to_state2[i];
183 if (accessing_symbol[final_state] == goal)
194 rules_used = TMALLOC(Value_t, nrules);
195 NO_SPACE(rules_used);
197 for (i = 0; i < nrules; ++i)
200 for (i = 0; i < nstates; ++i)
202 for (p = parser[i]; p; p = p->next)
204 if ((p->action_code == REDUCE) && MaySuppress(p))
205 rules_used[p->number] = 1;
210 for (i = 3; i < nrules; ++i)
217 fprintf(stderr, "%s: 1 rule never reduced\n", myname);
219 fprintf(stderr, "%s: %d rules never reduced\n", myname, nunused);
224 remove_conflicts(void)
228 action *p, *pref = 0;
232 SRconflicts = NEW2(nstates, Value_t);
233 RRconflicts = NEW2(nstates, Value_t);
234 for (i = 0; i < nstates; i++)
239 #if defined(YYBTYACC)
242 for (p = parser[i]; p; p = p->next)
244 if (p->symbol != symbol)
246 /* the first parse action for each symbol is the preferred action */
250 /* following conditions handle multiple, i.e., conflicting, parse actions */
251 else if (i == final_state && symbol == 0)
255 StartBacktrack(pref);
257 else if (pref != 0 && pref->action_code == SHIFT)
259 if (pref->prec > 0 && p->prec > 0)
261 if (pref->prec < p->prec)
263 pref->suppressed = 2;
266 else if (pref->prec > p->prec)
270 else if (pref->assoc == LEFT)
272 pref->suppressed = 2;
275 else if (pref->assoc == RIGHT)
281 pref->suppressed = 2;
289 StartBacktrack(pref);
296 StartBacktrack(pref);
301 SRconflicts[i] = SRcount;
302 RRconflicts[i] = RRcount;
307 total_conflicts(void)
309 fprintf(stderr, "%s: ", myname);
311 fprintf(stderr, "1 shift/reduce conflict");
312 else if (SRtotal > 1)
313 fprintf(stderr, "%d shift/reduce conflicts", SRtotal);
315 if (SRtotal && RRtotal)
316 fprintf(stderr, ", ");
319 fprintf(stderr, "1 reduce/reduce conflict");
320 else if (RRtotal > 1)
321 fprintf(stderr, "%d reduce/reduce conflicts", RRtotal);
323 fprintf(stderr, ".\n");
325 if (SRexpect >= 0 && SRtotal != SRexpect)
327 fprintf(stderr, "%s: ", myname);
328 fprintf(stderr, "expected %d shift/reduce conflict%s.\n",
329 SRexpect, PLURAL(SRexpect));
330 exit_code = EXIT_FAILURE;
332 if (RRexpect >= 0 && RRtotal != RRexpect)
334 fprintf(stderr, "%s: ", myname);
335 fprintf(stderr, "expected %d reduce/reduce conflict%s.\n",
336 RRexpect, PLURAL(RRexpect));
337 exit_code = EXIT_FAILURE;
342 sole_reduction(int stateno)
349 for (p = parser[stateno]; p; p = p->next)
351 if (p->action_code == SHIFT && MaySuppress(p))
353 else if ((p->action_code == REDUCE) && MaySuppress(p))
355 if (ruleno > 0 && p->number != ruleno)
373 defred = NEW2(nstates, Value_t);
374 for (i = 0; i < nstates; i++)
375 defred[i] = (Value_t) sole_reduction(i);
379 free_action_row(action *p)
396 for (i = 0; i < nstates; i++)
397 free_action_row(parser[i]);
408 DO_FREE(SRconflicts);
409 DO_FREE(RRconflicts);