X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/69363a9e4d0b8d3b51536434d3395d38519f617b..e62f1a899168bdf1658dd6d934dea407491a80ff:/src/conflicts.c?ds=sidebyside

diff --git a/src/conflicts.c b/src/conflicts.c
index 21ea7ce5..bcd6c846 100644
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -1,6 +1,6 @@
 /* Find and resolve or report look-ahead conflicts for bison,
 
-   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003
+   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004
    Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
@@ -36,12 +36,13 @@
 #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;
 
 
 
@@ -145,7 +146,7 @@ flush_shift (state *s, int token)
   transitions *trans = s->transitions;
   int i;
 
-  bitset_reset (lookaheadset, token);
+  bitset_reset (look_ahead_set, token);
   for (i = 0; i < trans->num; i++)
     if (!TRANSITION_IS_DISABLED (trans, i)
 	&& TRANSITION_SYMBOL (trans, i) == token)
@@ -153,16 +154,16 @@ flush_shift (state *s, int token)
 }
 
 
-/*-------------------------------------------------------------------.
-| 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);
 }
 
 
@@ -172,7 +173,7 @@ 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.           |
 `------------------------------------------------------------------*/
@@ -185,12 +186,12 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
   /* Find the rule to reduce by to get precedence of reduction.  */
   rule *redrule = reds->rules[ruleno];
   int redprec = redrule->prec->prec;
-  bitset lookaheads = reds->lookaheads[ruleno];
+  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
@@ -204,7 +205,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 	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.
@@ -216,7 +217,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 	    {
 	    case right_assoc:
 	      log_resolution (redrule, i, right_resolution);
-	      flush_reduce (lookaheads, i);
+	      flush_reduce (look_ahead_tokens, i);
 	      break;
 
 	    case left_assoc:
@@ -227,7 +228,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 	    case non_assoc:
 	      log_resolution (redrule, i, nonassoc_resolution);
 	      flush_shift (s, i);
-	      flush_reduce (lookaheads, i);
+	      flush_reduce (look_ahead_tokens, i);
 	      /* Record an explicit error for this token.  */
 	      errors[nerrs++] = symbols[i];
 	      break;
@@ -237,9 +238,12 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 	    }
       }
 
-  /* 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 (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))
     {
@@ -253,7 +257,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 | 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   |
-| lookaheads on which S raises a syntax error (%nonassoc).           |
+| look-ahead tokens on which S raises a syntax error (%nonassoc).    |
 `-------------------------------------------------------------------*/
 
 static void
@@ -266,30 +270,27 @@ set_conflicts (state *s, symbol **errors)
   if (s->consistent)
     return;
 
-  bitset_zero (lookaheadset);
+  bitset_zero (look_ahead_set);
 
   FOR_EACH_SHIFT (trans, i)
-    bitset_set (lookaheadset, TRANSITION_SYMBOL (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 < reds->num; ++i)
     if (reds->rules[i]->prec && reds->rules[i]->prec->prec
-	&& !bitset_disjoint_p (reds->lookaheads[i], lookaheadset))
-      {
-	resolve_sr_conflict (s, i, errors);
-	break;
-      }
+	&& !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 < reds->num; ++i)
     {
-      if (!bitset_disjoint_p (reds->lookaheads[i], lookaheadset))
+      if (!bitset_disjoint_p (reds->look_ahead_tokens[i], look_ahead_set))
 	conflicts[s->number] = 1;
 
-      bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]);
+      bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
     }
 }
 
@@ -303,12 +304,12 @@ void
 conflicts_solve (void)
 {
   state_number i;
-  /* List of lookaheads on which we explicitly raise a syntax error.  */
-  symbol **errors = MALLOC (errors, ntokens + 1);
+  /* List of look-ahead tokens on which we explicitly raise a syntax error.  */
+  symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);
 
-  CALLOC (conflicts, 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++)
@@ -340,18 +341,18 @@ count_sr_conflicts (state *s)
   if (!trans)
     return 0;
 
-  bitset_zero (lookaheadset);
-  bitset_zero (shiftset);
+  bitset_zero (look_ahead_set);
+  bitset_zero (shift_set);
 
   FOR_EACH_SHIFT (trans, i)
-    bitset_set (shiftset, TRANSITION_SYMBOL (trans, i));
+    bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
 
   for (i = 0; i < reds->num; ++i)
-    bitset_or (lookaheadset, lookaheadset, reds->lookaheads[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;
 }
@@ -365,7 +366,7 @@ count_sr_conflicts (state *s)
 +`----------------------------------------------------------------*/
 
 static int
-count_rr_conflicts (state *s, int one_per_token)
+count_rr_conflicts (state *s, bool one_per_token)
 {
   int i;
   reductions *reds = s->reductions;
@@ -376,7 +377,7 @@ count_rr_conflicts (state *s, int one_per_token)
       int count = 0;
       int j;
       for (j = 0; j < reds->num; ++j)
-	if (bitset_test (reds->lookaheads[j], i))
+	if (bitset_test (reds->look_ahead_tokens[j], i))
 	  count++;
 
       if (count >= 2)
@@ -431,7 +432,7 @@ 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.						  |
 `--------------------------------------------------------*/
 
@@ -463,7 +464,8 @@ 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;
@@ -480,11 +482,20 @@ conflicts_print (void)
 	}
   }
 
-  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.  */
@@ -492,15 +503,18 @@ conflicts_print (void)
     fprintf (stderr, "%s: ", current_file);
   conflict_report (stderr, src_total, rrc_total);
 
-  if (expected_conflicts != -1)
+  if (expected_sr_conflicts != -1 || expected_rr_conflicts != -1)
     {
+      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",
-			expected_conflicts),
-	      expected_conflicts);
-      if (rrc_total)
-	warn (_("expected 0 reduce/reduce conflicts"));
+			sr), sr);
+      if (! rrc_ok)
+	warn (ngettext ("expected %d reduce/reduce conflict",
+			"expected %d reduce/reduce conflicts",
+			rr), rr);
     }
 }
 
@@ -508,8 +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);
 }