X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/d57650a5ff3d9d1202f6d04de1a10e32cee85499..e62f1a899168bdf1658dd6d934dea407491a80ff:/src/conflicts.c

diff --git a/src/conflicts.c b/src/conflicts.c
index b64845e0..bcd6c846 100644
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -1,5 +1,6 @@
 /* Find and resolve or report look-ahead conflicts for bison,
-   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002
+
+   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004
    Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
@@ -20,29 +21,32 @@
    02111-1307, USA.  */
 
 #include "system.h"
-#include "bitset.h"
+
+#include <bitset.h>
+
+#include "LR0.h"
 #include "complain.h"
-#include "getargs.h"
-#include "symtab.h"
+#include "conflicts.h"
 #include "files.h"
+#include "getargs.h"
 #include "gram.h"
-#include "state.h"
 #include "lalr.h"
-#include "conflicts.h"
 #include "reader.h"
-#include "LR0.h"
+#include "state.h"
+#include "symtab.h"
 
 /* -1 stands for not specified. */
-int expected_conflicts = -1;
-static char *conflicts = NULL;
+int expected_sr_conflicts = -1;
+int expected_rr_conflicts = -1;
+static char *conflicts;
 struct obstack solved_conflicts_obstack;
 
-static bitset shiftset;
-static bitset lookaheadset;
+static bitset shift_set;
+static bitset look_ahead_set;
 
 
 
-enum conflict_resolution_e
+enum conflict_resolution
   {
     shift_resolution,
     reduce_resolution,
@@ -58,8 +62,8 @@ enum conflict_resolution_e
 `----------------------------------------------------------------*/
 
 static inline void
-log_resolution (rule_t *rule, int token,
-		enum conflict_resolution_e resolution)
+log_resolution (rule *r, symbol_number token,
+		enum conflict_resolution resolution)
 {
   if (report_flag & report_solved_conflicts)
     {
@@ -67,26 +71,26 @@ log_resolution (rule_t *rule, int token,
       switch (resolution)
 	{
 	case shift_resolution:
-	case left_resolution:
+	case right_resolution:
 	  obstack_fgrow2 (&solved_conflicts_obstack,
 			  _("\
     Conflict between rule %d and token %s resolved as shift"),
-			  rule->number,
+			  r->number,
 			  symbols[token]->tag);
 	  break;
 	case reduce_resolution:
-	case right_resolution:
+	case left_resolution:
 	  obstack_fgrow2 (&solved_conflicts_obstack,
 			  _("\
     Conflict between rule %d and token %s resolved as reduce"),
-			  rule->number,
+			  r->number,
 			  symbols[token]->tag);
 	  break;
 	case nonassoc_resolution:
 	  obstack_fgrow2 (&solved_conflicts_obstack,
 			  _("\
     Conflict between rule %d and token %s resolved as an error"),
-			  rule->number,
+			  r->number,
 			  symbols[token]->tag);
 	  break;
 	}
@@ -97,7 +101,7 @@ log_resolution (rule_t *rule, int token,
 	case shift_resolution:
 	  obstack_fgrow2 (&solved_conflicts_obstack,
 			  " (%s < %s)",
-			  rule->prec->tag,
+			  r->prec->tag,
 			  symbols[token]->tag);
 	  break;
 
@@ -105,7 +109,7 @@ log_resolution (rule_t *rule, int token,
 	  obstack_fgrow2 (&solved_conflicts_obstack,
 			  " (%s < %s)",
 			  symbols[token]->tag,
-			  rule->prec->tag);
+			  r->prec->tag);
 	  break;
 
 	case left_resolution:
@@ -137,28 +141,29 @@ log_resolution (rule_t *rule, int token,
 `------------------------------------------------------------------*/
 
 static void
-flush_shift (state_t *state, int token)
+flush_shift (state *s, int token)
 {
-  shifts *shiftp = state->shifts;
+  transitions *trans = s->transitions;
   int i;
 
-  bitset_reset (lookaheadset, token);
-  for (i = 0; i < shiftp->nshifts; i++)
-    if (!SHIFT_IS_DISABLED (shiftp, i) && SHIFT_SYMBOL (shiftp, i) == token)
-      SHIFT_DISABLE (shiftp, i);
+  bitset_reset (look_ahead_set, token);
+  for (i = 0; i < trans->num; i++)
+    if (!TRANSITION_IS_DISABLED (trans, i)
+	&& TRANSITION_SYMBOL (trans, i) == token)
+      TRANSITION_DISABLE (trans, i);
 }
 
 
-/*-------------------------------------------------------------------.
-| Turn off the reduce recorded for the specified token for the       |
-| specified lookahead.  Used when we resolve a shift-reduce conflict |
-| in favor of the shift.                                             |
-`-------------------------------------------------------------------*/
+/*--------------------------------------------------------------------.
+| Turn off the reduce recorded for the specified token for the        |
+| specified look-ahead.  Used when we resolve a shift-reduce conflict |
+| in favor of the shift.                                              |
+`--------------------------------------------------------------------*/
 
 static void
-flush_reduce (bitset lookaheads, int token)
+flush_reduce (bitset look_ahead_tokens, int token)
 {
-  bitset_reset (lookaheads, token);
+  bitset_reset (look_ahead_tokens, token);
 }
 
 
@@ -168,23 +173,25 @@ flush_reduce (bitset lookaheads, int token)
 | rule has a precedence.  A conflict is resolved by modifying the   |
 | shift or reduce tables so that there is no longer a conflict.     |
 |                                                                   |
-| LOOKAHEAD is the number of the lookahead bitset to consider.      |
+| RULENO is the number of the look-ahead bitset to consider.      |
+|                                                                   |
+| ERRORS can be used to store discovered explicit errors.           |
 `------------------------------------------------------------------*/
 
 static void
-resolve_sr_conflict (state_t *state, int lookahead)
+resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 {
-  int i;
+  symbol_number i;
+  reductions *reds = s->reductions;
   /* Find the rule to reduce by to get precedence of reduction.  */
-  rule_t *redrule = state->lookaheads_rule[lookahead];
+  rule *redrule = reds->rules[ruleno];
   int redprec = redrule->prec->prec;
-  bitset lookaheads = state->lookaheads[lookahead];
-  errs *errp = errs_new (ntokens + 1);
-  errp->nerrs = 0;
+  bitset look_ahead_tokens = reds->look_ahead_tokens[ruleno];
+  int nerrs = 0;
 
   for (i = 0; i < ntokens; i++)
-    if (bitset_test (lookaheads, i)
-	&& bitset_test (lookaheadset, i)
+    if (bitset_test (look_ahead_tokens, i)
+	&& bitset_test (look_ahead_set, i)
 	&& symbols[i]->prec)
       {
 	/* Shift-reduce conflict occurs for token number i
@@ -193,12 +200,12 @@ resolve_sr_conflict (state_t *state, int lookahead)
 	if (symbols[i]->prec < redprec)
 	  {
 	    log_resolution (redrule, i, reduce_resolution);
-	    flush_shift (state, i);
+	    flush_shift (s, i);
 	  }
 	else if (symbols[i]->prec > redprec)
 	  {
 	    log_resolution (redrule, i, shift_resolution);
-	    flush_reduce (lookaheads, i);
+	    flush_reduce (look_ahead_tokens, i);
 	  }
 	else
 	  /* Matching precedence levels.
@@ -210,92 +217,112 @@ resolve_sr_conflict (state_t *state, int lookahead)
 	    {
 	    case right_assoc:
 	      log_resolution (redrule, i, right_resolution);
-	      flush_reduce (lookaheads, i);
+	      flush_reduce (look_ahead_tokens, i);
 	      break;
 
 	    case left_assoc:
 	      log_resolution (redrule, i, left_resolution);
-	      flush_shift (state, i);
+	      flush_shift (s, i);
 	      break;
 
 	    case non_assoc:
 	      log_resolution (redrule, i, nonassoc_resolution);
-	      flush_shift (state, i);
-	      flush_reduce (lookaheads, i);
+	      flush_shift (s, i);
+	      flush_reduce (look_ahead_tokens, i);
 	      /* Record an explicit error for this token.  */
-	      errp->errs[errp->nerrs++] = i;
+	      errors[nerrs++] = symbols[i];
 	      break;
 
 	    case undef_assoc:
-	      assert (symbols[i]->assoc != undef_assoc);
-	      break;
+	      abort ();
 	    }
       }
 
-  /* Some tokens have been explicitly made errors.  Allocate a
-     permanent errs structure for this state, to record them.  */
-  state->errs = errs_dup (errp);
-  free (errp);
+  if (nerrs)
+    {
+      /* Some tokens have been explicitly made errors.  Allocate a
+	 permanent errs structure for this state, to record them.  */
+      state_errs_set (s, nerrs, errors);
+    }
 
   if (obstack_object_size (&solved_conflicts_obstack))
     {
       obstack_1grow (&solved_conflicts_obstack, '\0');
-      state->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
+      s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
     }
 }
 
 
+/*-------------------------------------------------------------------.
+| Solve the S/R conflicts of state S using the                       |
+| precedence/associativity, and flag it inconsistent if it still has |
+| conflicts.  ERRORS can be used as storage to compute the list of   |
+| look-ahead tokens on which S raises a syntax error (%nonassoc).    |
+`-------------------------------------------------------------------*/
+
 static void
-set_conflicts (state_t *state)
+set_conflicts (state *s, symbol **errors)
 {
   int i;
-  shifts *shiftp;
+  transitions *trans = s->transitions;
+  reductions *reds = s->reductions;
 
-  if (state->consistent)
+  if (s->consistent)
     return;
 
-  bitset_zero (lookaheadset);
+  bitset_zero (look_ahead_set);
 
-  shiftp = state->shifts;
-  for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
-    if (!SHIFT_IS_DISABLED (shiftp, i))
-      bitset_set (lookaheadset, SHIFT_SYMBOL (shiftp, i));
+  FOR_EACH_SHIFT (trans, i)
+    bitset_set (look_ahead_set, TRANSITION_SYMBOL (trans, i));
 
-  /* Loop over all rules which require lookahead in this state.  First
+  /* Loop over all rules which require look-ahead in this state.  First
      check for shift-reduce conflict, and try to resolve using
      precedence.  */
-  for (i = 0; i < state->nlookaheads; ++i)
-    if (state->lookaheads_rule[i]->prec
-	&& state->lookaheads_rule[i]->prec->prec
-	&& !bitset_disjoint_p (state->lookaheads[i], lookaheadset))
-      {
-	resolve_sr_conflict (state, i);
-	break;
-      }
+  for (i = 0; i < reds->num; ++i)
+    if (reds->rules[i]->prec && reds->rules[i]->prec->prec
+	&& !bitset_disjoint_p (reds->look_ahead_tokens[i], look_ahead_set))
+      resolve_sr_conflict (s, i, errors);
 
-  /* Loop over all rules which require lookahead in this state.  Check
+  /* Loop over all rules which require look-ahead in this state.  Check
      for conflicts not resolved above.  */
-  for (i = 0; i < state->nlookaheads; ++i)
+  for (i = 0; i < reds->num; ++i)
     {
-      if (!bitset_disjoint_p (state->lookaheads[i], lookaheadset))
-	conflicts[state->number] = 1;
+      if (!bitset_disjoint_p (reds->look_ahead_tokens[i], look_ahead_set))
+	conflicts[s->number] = 1;
 
-      bitset_or (lookaheadset, lookaheadset, state->lookaheads[i]);
+      bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
     }
 }
 
+
+/*----------------------------------------------------------------.
+| Solve all the S/R conflicts using the precedence/associativity, |
+| and flag as inconsistent the states that still have conflicts.  |
+`----------------------------------------------------------------*/
+
 void
 conflicts_solve (void)
 {
-  state_number_t i;
+  state_number i;
+  /* List of look-ahead tokens on which we explicitly raise a syntax error.  */
+  symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);
 
-  conflicts = XCALLOC (char, nstates);
-  shiftset = bitset_create (ntokens, BITSET_FIXED);
-  lookaheadset = bitset_create (ntokens, BITSET_FIXED);
+  conflicts = xcalloc (nstates, sizeof *conflicts);
+  shift_set = bitset_create (ntokens, BITSET_FIXED);
+  look_ahead_set = bitset_create (ntokens, BITSET_FIXED);
   obstack_init (&solved_conflicts_obstack);
 
   for (i = 0; i < nstates; i++)
-    set_conflicts (states[i]);
+    {
+      set_conflicts (states[i], errors);
+
+      /* For uniformity of the code, make sure all the states have a valid
+	 `errs' member.  */
+      if (!states[i]->errs)
+	states[i]->errs = errs_new (0, 0);
+    }
+
+  free (errors);
 }
 
 
@@ -304,28 +331,28 @@ conflicts_solve (void)
 `---------------------------------------------*/
 
 static int
-count_sr_conflicts (state_t *state)
+count_sr_conflicts (state *s)
 {
   int i;
   int src_count = 0;
-  shifts *shiftp = state->shifts;
+  transitions *trans = s->transitions;
+  reductions *reds = s->reductions;
 
-  if (!shiftp)
+  if (!trans)
     return 0;
 
-  bitset_zero (lookaheadset);
-  bitset_zero (shiftset);
+  bitset_zero (look_ahead_set);
+  bitset_zero (shift_set);
 
-  for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
-    if (!SHIFT_IS_DISABLED (shiftp, i))
-      bitset_set (shiftset, SHIFT_SYMBOL (shiftp, i));
+  FOR_EACH_SHIFT (trans, i)
+    bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
 
-  for (i = 0; i < state->nlookaheads; ++i)
-    bitset_or (lookaheadset, lookaheadset, state->lookaheads[i]);
+  for (i = 0; i < reds->num; ++i)
+    bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
 
-  bitset_and (lookaheadset, lookaheadset, shiftset);
+  bitset_and (look_ahead_set, look_ahead_set, shift_set);
 
-  src_count = bitset_count (lookaheadset);
+  src_count = bitset_count (look_ahead_set);
 
   return src_count;
 }
@@ -339,20 +366,18 @@ count_sr_conflicts (state_t *state)
 +`----------------------------------------------------------------*/
 
 static int
-count_rr_conflicts (state_t *state, int one_per_token)
+count_rr_conflicts (state *s, bool one_per_token)
 {
   int i;
+  reductions *reds = s->reductions;
   int rrc_count = 0;
 
-  if (state->nlookaheads < 2)
-    return 0;
-
   for (i = 0; i < ntokens; i++)
     {
       int count = 0;
       int j;
-      for (j = 0; j < state->nlookaheads; ++j)
-	if (bitset_test (state->lookaheads[j], i))
+      for (j = 0; j < reds->num; ++j)
+	if (bitset_test (reds->look_ahead_tokens[j], i))
 	  count++;
 
       if (count >= 2)
@@ -362,42 +387,21 @@ count_rr_conflicts (state_t *state, int one_per_token)
   return rrc_count;
 }
 
-/*--------------------------------------------------------------.
-| Return a human readable string which reports shift/reduce and |
-| reduce/reduce conflict numbers (SRC_NUM, RRC_NUM).            |
-`--------------------------------------------------------------*/
-
-static const char *
-conflict_report (int src_num, int rrc_num)
-{
-  static char res[4096];
-  char *cp = res;
-
-  if (src_num >= 1)
-    {
-      sprintf (cp, ngettext ("%d shift/reduce conflict",
-			     "%d shift/reduce conflicts", src_num), src_num);
-      cp += strlen (cp);
-    }
 
-  if (src_num > 0 && rrc_num > 0)
-    {
-      sprintf (cp, " %s ", _("and"));
-      cp += strlen (cp);
-    }
-
-  if (rrc_num >= 1)
-    {
-      sprintf (cp, ngettext ("%d reduce/reduce conflict",
-			     "%d reduce/reduce conflicts", rrc_num), rrc_num);
-      cp += strlen (cp);
-    }
-
-  *cp++ = '.';
-  *cp++ = '\n';
-  *cp++ = '\0';
+/*--------------------------------------------------------.
+| Report the number of conflicts, using the Yacc format.  |
+`--------------------------------------------------------*/
 
-  return res;
+static void
+conflict_report (FILE *out, int src_num, int rrc_num)
+{
+  if (src_num && rrc_num)
+    fprintf (out, _("conflicts: %d shift/reduce, %d reduce/reduce\n"),
+	     src_num, rrc_num);
+  else if (src_num)
+    fprintf (out, _("conflicts: %d shift/reduce\n"), src_num);
+  else if (rrc_num)
+    fprintf (out, _("conflicts: %d reduce/reduce\n"), rrc_num);
 }
 
 
@@ -408,16 +412,19 @@ conflict_report (int src_num, int rrc_num)
 void
 conflicts_output (FILE *out)
 {
-  bool printed_sth = FALSE;
-  state_number_t i;
+  bool printed_sth = false;
+  state_number i;
   for (i = 0; i < nstates; i++)
-    if (conflicts[i])
-      {
-	fprintf (out, _("State %d contains "), i);
-	fputs (conflict_report (count_sr_conflicts (states[i]),
-				count_rr_conflicts (states[i], TRUE)), out);
-	printed_sth = TRUE;
-      }
+    {
+      state *s = states[i];
+      if (conflicts[i])
+	{
+	  fprintf (out, _("State %d "), i);
+	  conflict_report (out, count_sr_conflicts (s),
+			   count_rr_conflicts (s, true));
+	  printed_sth = true;
+	}
+    }
   if (printed_sth)
     fputs ("\n\n", out);
 }
@@ -425,14 +432,14 @@ conflicts_output (FILE *out)
 /*--------------------------------------------------------.
 | Total the number of S/R and R/R conflicts.  Unlike the  |
 | code in conflicts_output, however, count EACH pair of   |
-| reductions for the same state and lookahead as one      |
+| reductions for the same state and look-ahead as one     |
 | conflict.						  |
 `--------------------------------------------------------*/
 
 int
 conflicts_total_count (void)
 {
-  state_number_t i;
+  state_number i;
   int count;
 
   /* Conflicts by state.  */
@@ -441,7 +448,7 @@ conflicts_total_count (void)
     if (conflicts[i])
       {
 	count += count_sr_conflicts (states[i]);
-	count += count_rr_conflicts (states[i], FALSE);
+	count += count_rr_conflicts (states[i], false);
       }
   return count;
 }
@@ -457,57 +464,57 @@ conflicts_print (void)
   /* Is the number of SR conflicts OK?  Either EXPECTED_CONFLICTS is
      not set, and then we want 0 SR, or else it is specified, in which
      case we want equality.  */
-  int src_ok = 0;
+  bool src_ok = false;
+  bool rrc_ok = false;
 
   int src_total = 0;
   int rrc_total = 0;
 
   /* Conflicts by state.  */
   {
-    state_number_t i;
+    state_number i;
 
     for (i = 0; i < nstates; i++)
       if (conflicts[i])
 	{
 	  src_total += count_sr_conflicts (states[i]);
-	  rrc_total += count_rr_conflicts (states[i], TRUE);
+	  rrc_total += count_rr_conflicts (states[i], true);
 	}
   }
 
-  src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts);
+  if (! glr_parser && rrc_total > 0 && expected_rr_conflicts != -1)
+    {
+      warn (_("%%expect-rr applies only to GLR parsers"));
+      expected_rr_conflicts = -1;
+    }
+
+  src_ok =
+    src_total == (expected_sr_conflicts == -1 ? 0 : expected_sr_conflicts);
+  rrc_ok =
+    rrc_total == (expected_rr_conflicts == -1 ? 0 : expected_rr_conflicts);
 
-  /* If there are no RR conflicts, and as many SR conflicts as
+  /* If there are as many RR conflicts and SR conflicts as
      expected, then there is nothing to report.  */
-  if (!rrc_total && src_ok)
+  if (rrc_ok && src_ok)
     return;
 
   /* Report the total number of conflicts on STDERR.  */
-  if (yacc_flag)
-    {
-      /* If invoked with `--yacc', use the output format specified by
-	 POSIX.  */
-      fprintf (stderr, _("conflicts: "));
-      if (src_total > 0)
-	fprintf (stderr, _(" %d shift/reduce"), src_total);
-      if (src_total > 0 && rrc_total > 0)
-	fprintf (stderr, ",");
-      if (rrc_total > 0)
-	fprintf (stderr, _(" %d reduce/reduce"), rrc_total);
-      putc ('\n', stderr);
-    }
-  else
-    {
-      fprintf (stderr, _("%s contains "), infile);
-      fputs (conflict_report (src_total, rrc_total), stderr);
-    }
+  if (! yacc_flag)
+    fprintf (stderr, "%s: ", current_file);
+  conflict_report (stderr, src_total, rrc_total);
 
-  if (expected_conflicts != -1 && !src_ok)
+  if (expected_sr_conflicts != -1 || expected_rr_conflicts != -1)
     {
-      complain_message_count++;
-      fprintf (stderr, ngettext ("expected %d shift/reduce conflict\n",
-				 "expected %d shift/reduce conflicts\n",
-				 expected_conflicts),
-	       expected_conflicts);
+      int sr = expected_sr_conflicts == -1 ? 0 : expected_sr_conflicts;
+      int rr = expected_rr_conflicts == -1 ? 0 : expected_rr_conflicts;
+      if (! src_ok)
+	warn (ngettext ("expected %d shift/reduce conflict",
+			"expected %d shift/reduce conflicts",
+			sr), sr);
+      if (! rrc_ok)
+	warn (ngettext ("expected %d reduce/reduce conflict",
+			"expected %d reduce/reduce conflicts",
+			rr), rr);
     }
 }
 
@@ -515,8 +522,8 @@ conflicts_print (void)
 void
 conflicts_free (void)
 {
-  XFREE (conflicts);
-  bitset_free (shiftset);
-  bitset_free (lookaheadset);
+  free (conflicts);
+  bitset_free (shift_set);
+  bitset_free (look_ahead_set);
   obstack_free (&solved_conflicts_obstack, NULL);
 }