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-rw-r--r--contrib/byacc/mkpar.c392
1 files changed, 392 insertions, 0 deletions
diff --git a/contrib/byacc/mkpar.c b/contrib/byacc/mkpar.c
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+++ b/contrib/byacc/mkpar.c
@@ -0,0 +1,392 @@
+/* $Id: mkpar.c,v 1.12 2012/05/26 00:42:18 tom Exp $ */
+
+#include "defs.h"
+
+static action *add_reduce(action *actions, int ruleno, int symbol);
+static action *add_reductions(int stateno, action *actions);
+static action *get_shifts(int stateno);
+static action *parse_actions(int stateno);
+static int sole_reduction(int stateno);
+static void defreds(void);
+static void find_final_state(void);
+static void free_action_row(action *p);
+static void remove_conflicts(void);
+static void total_conflicts(void);
+static void unused_rules(void);
+
+action **parser;
+
+int SRexpect;
+int RRexpect;
+
+int SRtotal;
+int RRtotal;
+
+Value_t *SRconflicts;
+Value_t *RRconflicts;
+Value_t *defred;
+Value_t *rules_used;
+Value_t nunused;
+Value_t final_state;
+
+static Value_t SRcount;
+static Value_t RRcount;
+
+void
+make_parser(void)
+{
+ int i;
+
+ parser = NEW2(nstates, action *);
+ for (i = 0; i < nstates; i++)
+ parser[i] = parse_actions(i);
+
+ find_final_state();
+ remove_conflicts();
+ unused_rules();
+ if (SRtotal + RRtotal > 0)
+ total_conflicts();
+ defreds();
+}
+
+static action *
+parse_actions(int stateno)
+{
+ action *actions;
+
+ actions = get_shifts(stateno);
+ actions = add_reductions(stateno, actions);
+ return (actions);
+}
+
+static action *
+get_shifts(int stateno)
+{
+ action *actions, *temp;
+ shifts *sp;
+ Value_t *to_state2;
+ Value_t i, k;
+ Value_t symbol;
+
+ actions = 0;
+ sp = shift_table[stateno];
+ if (sp)
+ {
+ to_state2 = sp->shift;
+ for (i = (Value_t) (sp->nshifts - 1); i >= 0; i--)
+ {
+ k = to_state2[i];
+ symbol = accessing_symbol[k];
+ if (ISTOKEN(symbol))
+ {
+ temp = NEW(action);
+ temp->next = actions;
+ temp->symbol = symbol;
+ temp->number = k;
+ temp->prec = symbol_prec[symbol];
+ temp->action_code = SHIFT;
+ temp->assoc = symbol_assoc[symbol];
+ actions = temp;
+ }
+ }
+ }
+ return (actions);
+}
+
+static action *
+add_reductions(int stateno, action *actions)
+{
+ int i, j, m, n;
+ int ruleno, tokensetsize;
+ unsigned *rowp;
+
+ tokensetsize = WORDSIZE(ntokens);
+ m = lookaheads[stateno];
+ n = lookaheads[stateno + 1];
+ for (i = m; i < n; i++)
+ {
+ ruleno = LAruleno[i];
+ rowp = LA + i * tokensetsize;
+ for (j = ntokens - 1; j >= 0; j--)
+ {
+ if (BIT(rowp, j))
+ actions = add_reduce(actions, ruleno, j);
+ }
+ }
+ return (actions);
+}
+
+static action *
+add_reduce(action *actions,
+ int ruleno,
+ int symbol)
+{
+ action *temp, *prev, *next;
+
+ prev = 0;
+ for (next = actions; next && next->symbol < symbol; next = next->next)
+ prev = next;
+
+ while (next && next->symbol == symbol && next->action_code == SHIFT)
+ {
+ prev = next;
+ next = next->next;
+ }
+
+ while (next && next->symbol == symbol &&
+ next->action_code == REDUCE && next->number < ruleno)
+ {
+ prev = next;
+ next = next->next;
+ }
+
+ temp = NEW(action);
+ temp->next = next;
+ temp->symbol = (Value_t) symbol;
+ temp->number = (Value_t) ruleno;
+ temp->prec = rprec[ruleno];
+ temp->action_code = REDUCE;
+ temp->assoc = rassoc[ruleno];
+
+ if (prev)
+ prev->next = temp;
+ else
+ actions = temp;
+
+ return (actions);
+}
+
+static void
+find_final_state(void)
+{
+ int goal, i;
+ Value_t *to_state2;
+ shifts *p;
+
+ p = shift_table[0];
+ to_state2 = p->shift;
+ goal = ritem[1];
+ for (i = p->nshifts - 1; i >= 0; --i)
+ {
+ final_state = to_state2[i];
+ if (accessing_symbol[final_state] == goal)
+ break;
+ }
+}
+
+static void
+unused_rules(void)
+{
+ int i;
+ action *p;
+
+ rules_used = TMALLOC(Value_t, nrules);
+ NO_SPACE(rules_used);
+
+ for (i = 0; i < nrules; ++i)
+ rules_used[i] = 0;
+
+ for (i = 0; i < nstates; ++i)
+ {
+ for (p = parser[i]; p; p = p->next)
+ {
+ if (p->action_code == REDUCE && p->suppressed == 0)
+ rules_used[p->number] = 1;
+ }
+ }
+
+ nunused = 0;
+ for (i = 3; i < nrules; ++i)
+ if (!rules_used[i])
+ ++nunused;
+
+ if (nunused)
+ {
+ if (nunused == 1)
+ fprintf(stderr, "%s: 1 rule never reduced\n", myname);
+ else
+ fprintf(stderr, "%s: %d rules never reduced\n", myname, nunused);
+ }
+}
+
+static void
+remove_conflicts(void)
+{
+ int i;
+ int symbol;
+ action *p, *pref = 0;
+
+ SRtotal = 0;
+ RRtotal = 0;
+ SRconflicts = NEW2(nstates, Value_t);
+ RRconflicts = NEW2(nstates, Value_t);
+ for (i = 0; i < nstates; i++)
+ {
+ SRcount = 0;
+ RRcount = 0;
+ symbol = -1;
+ for (p = parser[i]; p; p = p->next)
+ {
+ if (p->symbol != symbol)
+ {
+ pref = p;
+ symbol = p->symbol;
+ }
+ else if (i == final_state && symbol == 0)
+ {
+ SRcount++;
+ p->suppressed = 1;
+ }
+ else if (pref != 0 && pref->action_code == SHIFT)
+ {
+ if (pref->prec > 0 && p->prec > 0)
+ {
+ if (pref->prec < p->prec)
+ {
+ pref->suppressed = 2;
+ pref = p;
+ }
+ else if (pref->prec > p->prec)
+ {
+ p->suppressed = 2;
+ }
+ else if (pref->assoc == LEFT)
+ {
+ pref->suppressed = 2;
+ pref = p;
+ }
+ else if (pref->assoc == RIGHT)
+ {
+ p->suppressed = 2;
+ }
+ else
+ {
+ pref->suppressed = 2;
+ p->suppressed = 2;
+ }
+ }
+ else
+ {
+ SRcount++;
+ p->suppressed = 1;
+ }
+ }
+ else
+ {
+ RRcount++;
+ p->suppressed = 1;
+ }
+ }
+ SRtotal += SRcount;
+ RRtotal += RRcount;
+ SRconflicts[i] = SRcount;
+ RRconflicts[i] = RRcount;
+ }
+}
+
+static void
+total_conflicts(void)
+{
+ fprintf(stderr, "%s: ", myname);
+ if (SRtotal == 1)
+ fprintf(stderr, "1 shift/reduce conflict");
+ else if (SRtotal > 1)
+ fprintf(stderr, "%d shift/reduce conflicts", SRtotal);
+
+ if (SRtotal && RRtotal)
+ fprintf(stderr, ", ");
+
+ if (RRtotal == 1)
+ fprintf(stderr, "1 reduce/reduce conflict");
+ else if (RRtotal > 1)
+ fprintf(stderr, "%d reduce/reduce conflicts", RRtotal);
+
+ fprintf(stderr, ".\n");
+
+ if (SRexpect >= 0 && SRtotal != SRexpect)
+ {
+ fprintf(stderr, "%s: ", myname);
+ fprintf(stderr, "expected %d shift/reduce conflict%s.\n",
+ SRexpect, PLURAL(SRexpect));
+ exit_code = EXIT_FAILURE;
+ }
+ if (RRexpect >= 0 && RRtotal != RRexpect)
+ {
+ fprintf(stderr, "%s: ", myname);
+ fprintf(stderr, "expected %d reduce/reduce conflict%s.\n",
+ RRexpect, PLURAL(RRexpect));
+ exit_code = EXIT_FAILURE;
+ }
+}
+
+static int
+sole_reduction(int stateno)
+{
+ int count, ruleno;
+ action *p;
+
+ count = 0;
+ ruleno = 0;
+ for (p = parser[stateno]; p; p = p->next)
+ {
+ if (p->action_code == SHIFT && p->suppressed == 0)
+ return (0);
+ else if (p->action_code == REDUCE && p->suppressed == 0)
+ {
+ if (ruleno > 0 && p->number != ruleno)
+ return (0);
+ if (p->symbol != 1)
+ ++count;
+ ruleno = p->number;
+ }
+ }
+
+ if (count == 0)
+ return (0);
+ return (ruleno);
+}
+
+static void
+defreds(void)
+{
+ int i;
+
+ defred = NEW2(nstates, Value_t);
+ for (i = 0; i < nstates; i++)
+ defred[i] = (Value_t) sole_reduction(i);
+}
+
+static void
+free_action_row(action *p)
+{
+ action *q;
+
+ while (p)
+ {
+ q = p->next;
+ FREE(p);
+ p = q;
+ }
+}
+
+void
+free_parser(void)
+{
+ int i;
+
+ for (i = 0; i < nstates; i++)
+ free_action_row(parser[i]);
+
+ FREE(parser);
+}
+
+#ifdef NO_LEAKS
+void
+mkpar_leaks(void)
+{
+ DO_FREE(defred);
+ DO_FREE(rules_used);
+ DO_FREE(SRconflicts);
+ DO_FREE(RRconflicts);
+}
+#endif
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