X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/8307162d58343d40c8e6630326575edd71771957..a26424642b1de2c5e237cd69a54f12b2f430321f:/src/print.c

diff --git a/src/print.c b/src/print.c
index ae2ead9a..cb227aa5 100644
--- a/src/print.c
+++ b/src/print.c
@@ -1,43 +1,44 @@
 /* Print information on generated parser, for bison,
-   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002
-   Free Software Foundation, Inc.
+
+   Copyright (C) 1984, 1986, 1989, 2000-2005, 2007, 2009-2012 Free
+   Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
-   Bison is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
 
-   Bison is distributed in the hope that it will be useful,
+   This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with Bison; see the file COPYING.  If not, write to
-   the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-   Boston, MA 02111-1307, USA.  */
-
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
+#include <config.h>
 #include "system.h"
-#include "quotearg.h"
-#include "files.h"
-#include "symtab.h"
-#include "gram.h"
+
+#include <bitset.h>
+
 #include "LR0.h"
-#include "lalr.h"
+#include "closure.h"
 #include "conflicts.h"
+#include "files.h"
 #include "getargs.h"
-#include "state.h"
-#include "reader.h"
+#include "gram.h"
+#include "lalr.h"
+#include "muscle-tab.h"
 #include "print.h"
+#include "reader.h"
 #include "reduce.h"
-#include "closure.h"
-#include "bitset.h"
+#include "state.h"
+#include "symtab.h"
+#include "tables.h"
 
-static bitset shiftset;
-static bitset lookaheadset;
+static bitset no_reduce_set;
 
 #if 0
 static void
@@ -66,19 +67,19 @@ max_length (size_t *width, const char *str)
 `--------------------------------*/
 
 static void
-print_core (FILE *out, state_t *state)
+print_core (FILE *out, state *s)
 {
-  int i;
-  item_number_t *sitems = state->items;
-  int snritems   = state->nitems;
-  symbol_t *previous_lhs = NULL;
+  size_t i;
+  item_number *sitems = s->items;
+  size_t snritems = s->nitems;
+  symbol *previous_lhs = NULL;
 
   /* Output all the items of a state, not only its kernel.  */
   if (report_flag & report_itemsets)
     {
       closure (sitems, snritems);
       sitems = itemset;
-      snritems = nritemset;
+      snritems = nitemset;
     }
 
   if (!snritems)
@@ -88,54 +89,55 @@ print_core (FILE *out, state_t *state)
 
   for (i = 0; i < snritems; i++)
     {
-      item_number_t *sp;
-      item_number_t *sp1;
-      int rule;
+      item_number *sp;
+      item_number *sp1;
+      rule_number r;
 
       sp1 = sp = ritem + sitems[i];
 
       while (*sp >= 0)
 	sp++;
 
-      rule = item_number_as_rule_number (*sp);
+      r = item_number_as_rule_number (*sp);
 
-      rule_lhs_print (&rules[rule], previous_lhs, out);
-      previous_lhs = rules[rule].lhs;
+      rule_lhs_print (&rules[r], previous_lhs, out);
+      previous_lhs = rules[r].lhs;
 
-      for (sp = rules[rule].rhs; sp < sp1; sp++)
+      for (sp = rules[r].rhs; sp < sp1; sp++)
 	fprintf (out, " %s", symbols[*sp]->tag);
       fputs (" .", out);
       for (/* Nothing */; *sp >= 0; ++sp)
 	fprintf (out, " %s", symbols[*sp]->tag);
 
-      /* Display the lookaheads?  */
-      if (report_flag & report_lookaheads)
-	state_rule_lookaheads_print (state, &rules[rule], out);
+      /* Display the lookahead tokens?  */
+      if (report_flag & report_lookahead_tokens
+          && item_number_is_rule_number (*sp1))
+	state_rule_lookahead_tokens_print (s, &rules[r], out);
 
       fputc ('\n', out);
     }
 }
 
 
-/*----------------------------------------------------------------.
-| Report the shifts iff DISPLAY_SHIFTS_P or the gotos of STATE on |
-| OUT.                                                            |
-`----------------------------------------------------------------*/
+/*------------------------------------------------------------.
+| Report the shifts iff DISPLAY_SHIFTS_P or the gotos of S on |
+| OUT.                                                        |
+`------------------------------------------------------------*/
 
 static void
-print_transitions (state_t *state, FILE *out, bool display_transitions_p)
+print_transitions (state *s, FILE *out, bool display_transitions_p)
 {
-  transitions_t *transitions = state->transitions;
+  transitions *trans = s->transitions;
   size_t width = 0;
   int i;
 
-  /* Compute the width of the lookaheads column.  */
-  for (i = 0; i < transitions->num; i++)
-    if (!TRANSITION_IS_DISABLED (transitions, i)
-	&& TRANSITION_IS_SHIFT (transitions, i) == display_transitions_p)
+  /* Compute the width of the lookahead token column.  */
+  for (i = 0; i < trans->num; i++)
+    if (!TRANSITION_IS_DISABLED (trans, i)
+	&& TRANSITION_IS_SHIFT (trans, i) == display_transitions_p)
       {
-	symbol_t *symbol = symbols[TRANSITION_SYMBOL (transitions, i)];
-	max_length (&width, symbol->tag);
+	symbol *sym = symbols[TRANSITION_SYMBOL (trans, i)];
+	max_length (&width, sym->tag);
       }
 
   /* Nothing to report. */
@@ -145,39 +147,39 @@ print_transitions (state_t *state, FILE *out, bool display_transitions_p)
   fputc ('\n', out);
   width += 2;
 
-  /* Report lookaheads and shifts.  */
-  for (i = 0; i < transitions->num; i++)
-    if (!TRANSITION_IS_DISABLED (transitions, i)
-	&& TRANSITION_IS_SHIFT (transitions, i) == display_transitions_p)
+  /* Report lookahead tokens and shifts.  */
+  for (i = 0; i < trans->num; i++)
+    if (!TRANSITION_IS_DISABLED (trans, i)
+	&& TRANSITION_IS_SHIFT (trans, i) == display_transitions_p)
       {
-	symbol_t *symbol = symbols[TRANSITION_SYMBOL (transitions, i)];
-	const char *tag = symbol->tag;
-	state_t *state1 = transitions->states[i];
+	symbol *sym = symbols[TRANSITION_SYMBOL (trans, i)];
+	const char *tag = sym->tag;
+	state *s1 = trans->states[i];
 	int j;
 
 	fprintf (out, "    %s", tag);
 	for (j = width - strlen (tag); j > 0; --j)
 	  fputc (' ', out);
 	if (display_transitions_p)
-	  fprintf (out, _("shift, and go to state %d\n"), state1->number);
+	  fprintf (out, _("shift, and go to state %d\n"), s1->number);
 	else
-	  fprintf (out, _("go to state %d\n"), state1->number);
+	  fprintf (out, _("go to state %d\n"), s1->number);
       }
 }
 
 
-/*------------------------------------------------------------.
-| Report the explicit errors of STATE raised from %nonassoc.  |
-`------------------------------------------------------------*/
+/*--------------------------------------------------------.
+| Report the explicit errors of S raised from %nonassoc.  |
+`--------------------------------------------------------*/
 
 static void
-print_errs (FILE *out, state_t *state)
+print_errs (FILE *out, state *s)
 {
-  errs_t *errp = state->errs;
+  errs *errp = s->errs;
   size_t width = 0;
   int i;
 
-  /* Compute the width of the lookaheads column.  */
+  /* Compute the width of the lookahead token column.  */
   for (i = 0; i < errp->num; ++i)
     if (errp->symbols[i])
       max_length (&width, errp->symbols[i]->tag);
@@ -189,7 +191,7 @@ print_errs (FILE *out, state_t *state)
   fputc ('\n', out);
   width += 2;
 
-  /* Report lookaheads and errors.  */
+  /* Report lookahead tokens and errors.  */
   for (i = 0; i < errp->num; ++i)
     if (errp->symbols[i])
       {
@@ -203,92 +205,25 @@ print_errs (FILE *out, state_t *state)
 }
 
 
-/*----------------------------------------------------------.
-| Return the default rule of this STATE if it has one, NULL |
-| otherwise.                                                |
-`----------------------------------------------------------*/
-
-static rule_t *
-state_default_rule (state_t *state)
-{
-  reductions_t *redp = state->reductions;
-  rule_t *default_rule = NULL;
-  int cmax = 0;
-  int i;
-
-  /* No need for a lookahead.  */
-  if (state->consistent)
-    return redp->rules[0];
-
-  /* 1. Each reduction is possibly masked by the lookaheads on which
-     we shift (S/R conflicts)...  */
-  bitset_zero (shiftset);
-  {
-    transitions_t *transitions = state->transitions;
-    FOR_EACH_SHIFT (transitions, i)
-      {
-	/* If this state has a shift for the error token, don't use a
-	     default rule.  */
-	if (TRANSITION_IS_ERROR (transitions, i))
-	  return NULL;
-	bitset_set (shiftset, TRANSITION_SYMBOL (transitions, i));
-      }
-  }
-
-  /* 2. Each reduction is possibly masked by the lookaheads on which
-     we raise an error (due to %nonassoc).  */
-  {
-    errs_t *errp = state->errs;
-    for (i = 0; i < errp->num; i++)
-      if (errp->symbols[i])
-	bitset_set (shiftset, errp->symbols[i]->number);
-  }
-
-  for (i = 0; i < redp->num; ++i)
-    {
-      int count = 0;
-
-      /* How many non-masked lookaheads are there for this reduction?
-	 */
-      bitset_andn (lookaheadset, redp->lookaheads[i], shiftset);
-      count = bitset_count (lookaheadset);
-
-      if (count > cmax)
-	{
-	  cmax = count;
-	  default_rule = redp->rules[i];
-	}
-
-      /* 3. And finally, each reduction is possibly masked by previous
-	 reductions (in R/R conflicts, we keep the first reductions).
-	 */
-      bitset_or (shiftset, shiftset, redp->lookaheads[i]);
-    }
-
-  return default_rule;
-}
-
-
-/*--------------------------------------------------------------------.
-| Report a reduction of RULE on LOOKAHEADS (which can be `default').  |
-| If not ENABLED, the rule is masked by a shift or a reduce (S/R and  |
-| R/R conflicts).                                                     |
-`--------------------------------------------------------------------*/
+/*-------------------------------------------------------------------------.
+| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be `default').  |
+| If not ENABLED, the rule is masked by a shift or a reduce (S/R and       |
+| R/R conflicts).                                                          |
+`-------------------------------------------------------------------------*/
 
 static void
 print_reduction (FILE *out, size_t width,
-		 const char *lookahead,
-		 rule_t *rule, bool enabled)
+		 const char *lookahead_token,
+		 rule *r, bool enabled)
 {
   int j;
-  fprintf (out, "    %s", lookahead);
-  for (j = width - strlen (lookahead); j > 0; --j)
+  fprintf (out, "    %s", lookahead_token);
+  for (j = width - strlen (lookahead_token); j > 0; --j)
     fputc (' ', out);
   if (!enabled)
     fputc ('[', out);
-  if (rule->number)
-    fprintf (out, _("reduce using rule %d (%s)"),
-	     rule->number, rule->lhs->tag);
+  if (r->number)
+    fprintf (out, _("reduce using rule %d (%s)"), r->number, r->lhs->tag);
   else
     fprintf (out, _("accept"));
   if (!enabled)
@@ -297,45 +232,50 @@ print_reduction (FILE *out, size_t width,
 }
 
 
-/*----------------------------------------------------.
-| Report on OUT the reduction actions of this STATE.  |
-`----------------------------------------------------*/
+/*-------------------------------------------.
+| Report on OUT the reduction actions of S.  |
+`-------------------------------------------*/
 
 static void
-print_reductions (FILE *out, state_t *state)
+print_reductions (FILE *out, state *s)
 {
-  transitions_t *transitions = state->transitions;
-  reductions_t *redp = state->reductions;
-  rule_t *default_rule = NULL;
+  transitions *trans = s->transitions;
+  reductions *reds = s->reductions;
+  rule *default_reduction = NULL;
   size_t width = 0;
   int i, j;
+  bool default_reduction_only = true;
 
-  if (redp->num == 0)
+  if (reds->num == 0)
     return;
 
-  default_rule = state_default_rule (state);
+  if (yydefact[s->number] != 0)
+    default_reduction = &rules[yydefact[s->number] - 1];
 
-  bitset_zero (shiftset);
-  FOR_EACH_SHIFT (transitions, i)
-    bitset_set (shiftset, TRANSITION_SYMBOL (transitions, i));
+  bitset_zero (no_reduce_set);
+  FOR_EACH_SHIFT (trans, i)
+    bitset_set (no_reduce_set, TRANSITION_SYMBOL (trans, i));
+  for (i = 0; i < s->errs->num; ++i)
+    if (s->errs->symbols[i])
+      bitset_set (no_reduce_set, s->errs->symbols[i]->number);
 
-  /* Compute the width of the lookaheads column.  */
-  if (default_rule)
+  /* Compute the width of the lookahead token column.  */
+  if (default_reduction)
     width = strlen (_("$default"));
 
-  if (redp->lookaheads)
+  if (reds->lookahead_tokens)
     for (i = 0; i < ntokens; i++)
       {
-	int count = bitset_test (shiftset, i);
+	bool count = bitset_test (no_reduce_set, i);
 
-	for (j = 0; j < redp->num; ++j)
-	  if (bitset_test (redp->lookaheads[j], i))
+	for (j = 0; j < reds->num; ++j)
+	  if (bitset_test (reds->lookahead_tokens[j], i))
 	    {
-	      if (count == 0)
+	      if (! count)
 		{
-		  if (redp->rules[j] != default_rule)
+		  if (reds->rules[j] != default_reduction)
 		    max_length (&width, symbols[i]->tag);
-		  count++;
+		  count = true;
 		}
 	      else
 		{
@@ -351,80 +291,93 @@ print_reductions (FILE *out, state_t *state)
   fputc ('\n', out);
   width += 2;
 
-  /* Report lookaheads (or $default) and reductions.  */
-  if (redp->lookaheads)
+  /* Report lookahead tokens (or $default) and reductions.  */
+  if (reds->lookahead_tokens)
     for (i = 0; i < ntokens; i++)
       {
-	int defaulted = 0;
-	int count = bitset_test (shiftset, i);
+	bool defaulted = false;
+	bool count = bitset_test (no_reduce_set, i);
+        if (count)
+          default_reduction_only = false;
 
-	for (j = 0; j < redp->num; ++j)
-	  if (bitset_test (redp->lookaheads[j], i))
+	for (j = 0; j < reds->num; ++j)
+	  if (bitset_test (reds->lookahead_tokens[j], i))
 	    {
-	      if (count == 0)
+	      if (! count)
 		{
-		  if (redp->rules[j] != default_rule)
-		    print_reduction (out, width,
-				     symbols[i]->tag,
-				     redp->rules[j], true);
+		  if (reds->rules[j] != default_reduction)
+                    {
+                      default_reduction_only = false;
+                      print_reduction (out, width,
+                                       symbols[i]->tag,
+                                       reds->rules[j], true);
+                    }
 		  else
-		    defaulted = 1;
-		  count++;
+		    defaulted = true;
+		  count = true;
 		}
 	      else
 		{
+                  default_reduction_only = false;
 		  if (defaulted)
 		    print_reduction (out, width,
 				     symbols[i]->tag,
-				     default_rule, true);
-		  defaulted = 0;
+				     default_reduction, true);
+		  defaulted = false;
 		  print_reduction (out, width,
 				   symbols[i]->tag,
-				   redp->rules[j], false);
+				   reds->rules[j], false);
 		}
 	    }
       }
 
-  if (default_rule)
-    print_reduction (out, width,
-		     _("$default"), default_rule, true);
+  if (default_reduction)
+    {
+      char *default_reductions =
+        muscle_percent_define_get ("lr.default-reductions");
+      print_reduction (out, width, _("$default"), default_reduction, true);
+      aver (0 == strcmp (default_reductions, "most")
+            || (0 == strcmp (default_reductions, "consistent")
+                && default_reduction_only)
+            || (reds->num == 1 && reds->rules[0]->number == 0));
+      free (default_reductions);
+    }
 }
 
 
 /*--------------------------------------------------------------.
 | Report on OUT all the actions (shifts, gotos, reductions, and |
-| explicit erros from %nonassoc) of STATE.                      |
+| explicit erros from %nonassoc) of S.                          |
 `--------------------------------------------------------------*/
 
 static void
-print_actions (FILE *out, state_t *state)
+print_actions (FILE *out, state *s)
 {
   /* Print shifts.  */
-  print_transitions (state, out, true);
-  print_errs (out, state);
-  print_reductions (out, state);
+  print_transitions (s, out, true);
+  print_errs (out, s);
+  print_reductions (out, s);
   /* Print gotos.  */
-  print_transitions (state, out, false);
+  print_transitions (s, out, false);
 }
 
 
-/*--------------------------------------.
-| Report all the data on STATE on OUT.  |
-`--------------------------------------*/
+/*----------------------------------.
+| Report all the data on S on OUT.  |
+`----------------------------------*/
 
 static void
-print_state (FILE *out, state_t *state)
+print_state (FILE *out, state *s)
 {
   fputs ("\n\n", out);
-  fprintf (out, _("state %d"), state->number);
+  fprintf (out, _("state %d"), s->number);
   fputc ('\n', out);
-  print_core (out, state);
-  print_actions (out, state);
-  if ((report_flag & report_solved_conflicts)
-      && state->solved_conflicts)
+  print_core (out, s);
+  print_actions (out, s);
+  if ((report_flag & report_solved_conflicts) && s->solved_conflicts)
     {
       fputc ('\n', out);
-      fputs (state->solved_conflicts, out);
+      fputs (s->solved_conflicts, out);
     }
 }
 
@@ -446,7 +399,7 @@ do {						\
 static void
 print_grammar (FILE *out)
 {
-  symbol_number_t i;
+  symbol_number i;
   char buffer[90];
   int column = 0;
 
@@ -458,13 +411,13 @@ print_grammar (FILE *out)
     if (token_translations[i] != undeftoken->number)
       {
 	const char *tag = symbols[token_translations[i]]->tag;
-	rule_number_t r;
-	item_number_t *rhsp;
+	rule_number r;
+	item_number *rhsp;
 
 	buffer[0] = 0;
 	column = strlen (tag);
 	fputs (tag, out);
-	END_TEST (50);
+	END_TEST (65);
 	sprintf (buffer, " (%d)", i);
 
 	for (r = 0; r < nrules; r++)
@@ -484,12 +437,12 @@ print_grammar (FILE *out)
   for (i = ntokens; i < nsyms; i++)
     {
       int left_count = 0, right_count = 0;
-      rule_number_t r;
+      rule_number r;
       const char *tag = symbols[i]->tag;
 
       for (r = 0; r < nrules; r++)
 	{
-	  item_number_t *rhsp;
+	  item_number *rhsp;
 	  if (rules[r].lhs->number == i)
 	    left_count++;
 	  for (rhsp = rules[r].rhs; *rhsp >= 0; rhsp++)
@@ -508,14 +461,16 @@ print_grammar (FILE *out)
 
       if (left_count > 0)
 	{
-	  END_TEST (50);
+	  END_TEST (65);
 	  sprintf (buffer + strlen (buffer), _(" on left:"));
 
 	  for (r = 0; r < nrules; r++)
 	    {
-	      END_TEST (65);
 	      if (rules[r].lhs->number == i)
-		sprintf (buffer + strlen (buffer), " %d", r);
+		{
+		  END_TEST (65);
+		  sprintf (buffer + strlen (buffer), " %d", r);
+		}
 	    }
 	}
 
@@ -523,11 +478,11 @@ print_grammar (FILE *out)
 	{
 	  if (left_count > 0)
 	    sprintf (buffer + strlen (buffer), ",");
-	  END_TEST (50);
+	  END_TEST (65);
 	  sprintf (buffer + strlen (buffer), _(" on right:"));
 	  for (r = 0; r < nrules; r++)
 	    {
-	      item_number_t *rhsp;
+	      item_number *rhsp;
 	      for (rhsp = rules[r].rhs; *rhsp >= 0; rhsp++)
 		if (item_number_as_symbol_number (*rhsp) == i)
 		  {
@@ -544,7 +499,7 @@ print_grammar (FILE *out)
 void
 print_results (void)
 {
-  state_number_t i;
+  state_number i;
 
   /* We used to use just .out if SPEC_NAME_PREFIX (-p) was used, but
      that conflicts with Posix.  */
@@ -552,7 +507,8 @@ print_results (void)
 
   reduce_output (out);
   grammar_rules_partial_print (out,
-			       _("Rules never reduced"), rule_never_reduced_p);
+			       _("Rules useless in parser due to conflicts"),
+                                 rule_useless_in_parser_p);
   conflicts_output (out);
 
   print_grammar (out);
@@ -562,12 +518,10 @@ print_results (void)
   if (report_flag & report_itemsets)
     new_closure (nritems);
   /* Storage for print_reductions.  */
-  shiftset =  bitset_create (ntokens, BITSET_FIXED);
-  lookaheadset = bitset_create (ntokens, BITSET_FIXED);
+  no_reduce_set =  bitset_create (ntokens, BITSET_FIXED);
   for (i = 0; i < nstates; i++)
     print_state (out, states[i]);
-  bitset_free (shiftset);
-  bitset_free (lookaheadset);
+  bitset_free (no_reduce_set);
   if (report_flag & report_itemsets)
     free_closure ();