static int nentries;
static short **froms = NULL;
static short **tos = NULL;
+static unsigned int **conflict_tos = NULL;
static short *tally = NULL;
static short *width = NULL;
static short *actrow = NULL;
+static short *conflrow = NULL;
static short *state_count = NULL;
static short *order = NULL;
static short *base = NULL;
static short *pos = NULL;
+static unsigned int *conflict_table = NULL;
+static unsigned int *conflict_list = NULL;
+static int conflict_list_cnt;
+static int conflict_list_free;
+
/* TABLE_SIZE is the allocated size of both TABLE and CHECK.
We start with the original hard-coded value: SHRT_MAX
(yes, not USHRT_MAX). */
table = XREALLOC (table, short, table_size);
check = XREALLOC (check, short, table_size);
+ if (glr_parser)
+ conflict_table = XREALLOC (conflict_table, unsigned int, table_size);
for (/* Nothing. */; old_size < table_size; ++old_size)
{
/*-------------------------------------------------------------.
| Prepare the muscles related to the rules: rhs, prhs, r1, r2, |
-| rline. |
+| rline, dprec, merger |
`-------------------------------------------------------------*/
static void
unsigned int *rline = XMALLOC (unsigned int, nrules + 1);
symbol_number_t *r1 = XMALLOC (symbol_number_t, nrules + 1);
unsigned int *r2 = XMALLOC (unsigned int, nrules + 1);
+ short *dprec = XMALLOC (short, nrules + 1);
+ short *merger = XMALLOC (short, nrules + 1);
for (r = 1; r < nrules + 1; ++r)
{
rhs[i++] = -1;
/* Line where rule was defined. */
rline[r] = rules[r].location.first_line;
+ /* Dynamic precedence (GLR) */
+ dprec[r] = rules[r].dprec;
+ /* Merger-function index (GLR) */
+ merger[r] = rules[r].merger;
}
assert (i == nritems);
muscle_insert_unsigned_int_table ("rline", rline, 0, 1, nrules + 1);
muscle_insert_symbol_number_table ("r1", r1, 0, 1, nrules + 1);
muscle_insert_unsigned_int_table ("r2", r2, 0, 1, nrules + 1);
+ muscle_insert_short_table ("dprec", dprec, 0, 1, nrules + 1);
+ muscle_insert_short_table ("merger", merger, 0, 1, nrules + 1);
free (rhs);
free (prhs);
free (rline);
free (r1);
free (r2);
+ free (dprec);
+ free (merger);
}
/*--------------------------------------------.
}
+/*-------------------------------------------------------------------.
+| For GLR parsers, for each conflicted token in STATE, as indicated |
+| by non-zero entries in conflrow, create a list of possible |
+| reductions that are alternatives to the shift or reduction |
+| currently recorded for that token in STATE. Store the alternative |
+| reductions followed by a 0 in conflict_list, updating |
+| conflict_list_cnt, and storing an index to the start of the list |
+| back into conflrow. |
+`-------------------------------------------------------------------*/
+
+static void
+conflict_row (state_t *state)
+{
+ int i, j;
+
+ if (! glr_parser)
+ return;
+
+ for (j = 0; j < ntokens; j += 1)
+ if (conflrow[j])
+ {
+ conflrow[j] = conflict_list_cnt;
+
+ /* find all reductions for token j, and record all that do
+ * not match actrow[j] */
+ for (i = 0; i < state->nlookaheads; i += 1)
+ if (bitset_test (state->lookaheads[i], j)
+ && actrow[j] != -state->lookaheads_rule[i]->number)
+ {
+ assert (conflict_list_free > 0);
+ conflict_list[conflict_list_cnt]
+ = state->lookaheads_rule[i]->number;
+ conflict_list_cnt += 1;
+ conflict_list_free -= 1;
+ }
+
+ /* Leave a 0 at the end */
+ assert (conflict_list_free > 0);
+ conflict_list_cnt += 1;
+ conflict_list_free -= 1;
+ }
+}
+
+
/*------------------------------------------------------------------.
| Decide what to do for each type of token if seen as the lookahead |
| token in specified state. The value returned is used as the |
| This is where conflicts are resolved. The loop over lookahead |
| rules considered lower-numbered rules last, and the last rule |
| considered that likes a token gets to handle it. |
+| |
+| For GLR parsers, also sets conflrow[SYM] to an index into |
+| conflict_list iff there is an unresolved conflict (s/r or r/r) |
+| with symbol SYM. The default reduction is not used for a symbol |
+| that has any such conflicts. |
`------------------------------------------------------------------*/
static int
errs *errp = state->errs;
/* set nonzero to inhibit having any default reduction */
int nodefault = 0;
+ int conflicted = 0;
for (i = 0; i < ntokens; i++)
- actrow[i] = 0;
+ actrow[i] = conflrow[i] = 0;
if (redp->nreds >= 1)
{
/* and record this rule as the rule to use if that
token follows. */
if (bitset_test (state->lookaheads[i], j))
- actrow[j] = -state->lookaheads_rule[i]->number;
+ {
+ if (actrow[j] != 0)
+ conflicted = conflrow[j] = 1;
+ actrow[j] = -state->lookaheads_rule[i]->number;
+ }
}
/* Now see which tokens are allowed for shifts in this state. For
if (ISVAR (symbol))
break;
+ if (actrow[symbol] != 0)
+ conflicted = conflrow[symbol] = 1;
actrow[symbol] = shift_state;
/* Do not use any default reduction if there is a shift for
}
}
- /* actions which match the default are replaced with zero,
- which means "use the default" */
+ /* GLR parsers need space for conflict lists, so we can't
+ default conflicted entries. For non-conflicted entries
+ or as long as we are not building a GLR parser,
+ actions that match the default are replaced with zero,
+ which means "use the default". */
if (max > 0)
{
int j;
for (j = 0; j < ntokens; j++)
- if (actrow[j] == default_rule)
+ if (actrow[j] == default_rule && ! (glr_parser && conflrow[j]))
actrow[j] = 0;
-
- default_rule = -default_rule;
}
+ default_rule = -default_rule;
}
}
if (actrow[i] == SHRT_MIN)
actrow[i] = 0;
+ if (conflicted)
+ conflict_row (state);
+
return default_rule;
}
short *sp;
short *sp1;
short *sp2;
+ unsigned int *sp3;
count = 0;
for (i = 0; i < ntokens; i++)
froms[state] = sp1 = sp = XCALLOC (short, count);
tos[state] = sp2 = XCALLOC (short, count);
+ if (glr_parser)
+ conflict_tos[state] = sp3 = XCALLOC (unsigned int, count);
+ else
+ conflict_tos[state] = NULL;
for (i = 0; i < ntokens; i++)
if (actrow[i] != 0)
{
*sp1++ = i;
*sp2++ = actrow[i];
+ if (glr_parser)
+ *sp3++ = conflrow[i];
}
tally[state] = count;
token_actions (void)
{
size_t i;
+ int nconflict = conflicts_total_count ();
+
short *yydefact = XCALLOC (short, nstates);
actrow = XCALLOC (short, ntokens);
+
+ conflrow = XCALLOC (short, ntokens);
+ if (glr_parser)
+ {
+ conflict_list = XCALLOC (unsigned int, 1 + 2 * nconflict);
+ conflict_list_free = 2 * nconflict;
+ conflict_list_cnt = 1;
+ }
+ else
+ conflict_list_free = conflict_list_cnt = 0;
+
for (i = 0; i < nstates; ++i)
{
yydefact[i] = action_row (states[i]);
muscle_insert_short_table ("defact", yydefact,
yydefact[0], 1, nstates);
XFREE (actrow);
+ XFREE (conflrow);
XFREE (yydefact);
}
fputs ("]])\n\n", out);
}
+/*--------------------------------------.
+| Output the merge functions to OUT. |
+`--------------------------------------*/
+
+void
+merger_output (FILE *out)
+{
+ int n;
+ merger_list* p;
+
+ fputs ("m4_define([b4_mergers], \n[[", out);
+ for (n = 1, p = merge_functions; p != NULL; n += 1, p = p->next)
+ {
+ if (p->type[0] == '\0')
+ fprintf (out, " case %d: yyval = %s (*yy0, *yy1); break;\n",
+ n, p->name);
+ else
+ fprintf (out, " case %d: yyval.%s = %s (*yy0, *yy1); break;\n",
+ n, p->type, p->name);
+ }
+ fputs ("]])\n\n", out);
+}
/*---------------------------------------.
| Output the tokens definition to OOUT. |
int loc = 0;
short *from = froms[i];
short *to = tos[i];
+ unsigned int *conflict_to = conflict_tos[i];
assert (t);
{
loc = j + from[k];
table[loc] = to[k];
+ if (glr_parser && conflict_to != NULL)
+ conflict_table[loc] = conflict_to[k];
check[loc] = from[k];
}
base = XCALLOC (short, nvectors);
pos = XCALLOC (short, nentries);
table = XCALLOC (short, table_size);
+ if (glr_parser)
+ conflict_table = XCALLOC (unsigned int, table_size);
check = XCALLOC (short, table_size);
lowzero = 0;
{
XFREE (froms[i]);
XFREE (tos[i]);
+ XFREE (conflict_tos[i]);
}
XFREE (froms);
XFREE (tos);
+ XFREE (conflict_tos);
XFREE (pos);
}
-/* the following functions output yytable, yycheck
+/* the following functions output yytable, yycheck, yyconflp, yyconfl,
and the vectors whose elements index the portion starts */
static void
}
+static void
+output_conflicts (void)
+{
+ /* GLR parsing slightly modifies yytable and yycheck
+ (and thus yypact) so that in states with unresolved conflicts,
+ the default reduction is not used in the conflicted entries, so
+ that there is a place to put a conflict pointer. This means that
+ yyconflp and yyconfl are nonsense for a non-GLR parser, so we
+ avoid accidents by not writing them out in that case. */
+ if (! glr_parser)
+ return;
+
+ muscle_insert_unsigned_int_table ("conflict_list_heads", conflict_table,
+ conflict_table[0], 1, high+1);
+ muscle_insert_unsigned_int_table ("conflicting_rules", conflict_list,
+ conflict_list[0], 1, conflict_list_cnt);
+
+ XFREE (conflict_table);
+ XFREE (conflict_list);
+}
+
+
static void
output_check (void)
{
froms = XCALLOC (short *, nvectors);
tos = XCALLOC (short *, nvectors);
+ conflict_tos = XCALLOC (unsigned int *, nvectors);
tally = XCALLOC (short, nvectors);
width = XCALLOC (short, nvectors);
output_base ();
output_table ();
+ output_conflicts ();
output_check ();
fputs ("m4_init()\n", out);
actions_output (out);
+ merger_output (out);
token_definitions_output (out);
symbol_destructors_output (out);
symbol_printers_output (out);
/* Find the right skeleton file. */
if (!skeleton)
- skeleton = "yacc.c";
+ {
+ if (glr_parser)
+ skeleton = "glr.c";
+ else
+ skeleton = "yacc.c";
+ }
/* Parse the skeleton file and output the needed parsers. */
muscle_insert ("skeleton", skeleton);
projects / bison.git / blobdiff