]> git.saurik.com Git - bison.git/blobdiff - src/conflicts.c
maint: run "make update-copyright".
[bison.git] / src / conflicts.c
index cb7f13a6ebe3b24f44a39536ef07f477da71bda2..9603498970c4185f285e2864a634cd15053861ec 100644 (file)
@@ -1,24 +1,22 @@
 /* Find and resolve or report lookahead conflicts for bison,
 
-   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-   2007 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989, 1992, 2000-2011 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 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.
+   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 3 of the License, or
+   (at your option) any later version.
 
-   Bison 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.
+   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., 51 Franklin Street, Fifth Floor, Boston, MA
-   02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include "system.h"
@@ -32,6 +30,7 @@
 #include "getargs.h"
 #include "gram.h"
 #include "lalr.h"
+#include "print-xml.h"
 #include "reader.h"
 #include "state.h"
 #include "symtab.h"
@@ -41,6 +40,7 @@ int expected_sr_conflicts = -1;
 int expected_rr_conflicts = -1;
 static char *conflicts;
 static struct obstack solved_conflicts_obstack;
+static struct obstack solved_conflicts_xml_obstack;
 
 static bitset shift_set;
 static bitset lookahead_set;
@@ -74,23 +74,25 @@ log_resolution (rule *r, symbol_number token,
        case shift_resolution:
        case right_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,
-                         _("\
-    Conflict between rule %d and token %s resolved as shift"),
+                         _("    Conflict between rule %d and token %s"
+                           " resolved as shift"),
                          r->number,
                          symbols[token]->tag);
          break;
+
        case reduce_resolution:
        case left_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,
-                         _("\
-    Conflict between rule %d and token %s resolved as reduce"),
+                         _("    Conflict between rule %d and token %s"
+                           " resolved as reduce"),
                          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"),
+                         _("    Conflict between rule %d and token %s"
+                           " resolved as an error"),
                          r->number,
                          symbols[token]->tag);
          break;
@@ -124,21 +126,95 @@ log_resolution (rule *r, symbol_number token,
                          " (%%right %s)",
                          symbols[token]->tag);
          break;
+
        case nonassoc_resolution:
          obstack_fgrow1 (&solved_conflicts_obstack,
                          " (%%nonassoc %s)",
                          symbols[token]->tag);
          break;
        }
+
       obstack_sgrow (&solved_conflicts_obstack, ".\n");
     }
+
+  /* XML report */
+  if (xml_flag)
+    {
+      /* The description of the resolution. */
+      switch (resolution)
+        {
+        case shift_resolution:
+        case right_resolution:
+          obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                          "        <resolution rule=\"%d\" symbol=\"%s\""
+                          " type=\"shift\">",
+                          r->number,
+                          xml_escape (symbols[token]->tag));
+          break;
+
+        case reduce_resolution:
+        case left_resolution:
+          obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                          "        <resolution rule=\"%d\" symbol=\"%s\""
+                          " type=\"reduce\">",
+                          r->number,
+                          xml_escape (symbols[token]->tag));
+          break;
+
+        case nonassoc_resolution:
+          obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                          "        <resolution rule=\"%d\" symbol=\"%s\""
+                          " type=\"error\">",
+                          r->number,
+                          xml_escape (symbols[token]->tag));
+          break;
+        }
+
+      /* The reason. */
+      switch (resolution)
+        {
+        case shift_resolution:
+          obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                          "%s &lt; %s",
+                          xml_escape_n (0, r->prec->tag),
+                          xml_escape_n (1, symbols[token]->tag));
+          break;
+
+        case reduce_resolution:
+          obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                          "%s &lt; %s",
+                          xml_escape_n (0, symbols[token]->tag),
+                          xml_escape_n (1, r->prec->tag));
+          break;
+
+        case left_resolution:
+          obstack_fgrow1 (&solved_conflicts_xml_obstack,
+                          "%%left %s",
+                          xml_escape (symbols[token]->tag));
+          break;
+
+        case right_resolution:
+          obstack_fgrow1 (&solved_conflicts_xml_obstack,
+                          "%%right %s",
+                          xml_escape (symbols[token]->tag));
+          break;
+
+        case nonassoc_resolution:
+          obstack_fgrow1 (&solved_conflicts_xml_obstack,
+                          "%%nonassoc %s",
+                          xml_escape (symbols[token]->tag));
+      break;
+        }
+
+      obstack_sgrow (&solved_conflicts_xml_obstack, "</resolution>\n");
+    }
 }
 
 
 /*------------------------------------------------------------------.
 | Turn off the shift recorded for the specified token in the        |
 | specified state.  Used when we resolve a shift-reduce conflict in |
-| favor of the reduction.                                           |
+| favor of the reduction or as an error (%nonassoc).                |
 `------------------------------------------------------------------*/
 
 static void
@@ -156,9 +232,9 @@ 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 in the         |
+| specified lookahead set.  Used when we resolve a shift-reduce       |
+| conflict in favor of the shift or as an error (%nonassoc).          |
 `--------------------------------------------------------------------*/
 
 static void
@@ -176,11 +252,12 @@ flush_reduce (bitset lookahead_tokens, int token)
 |                                                                   |
 | RULENO is the number of the lookahead bitset to consider.         |
 |                                                                   |
-| ERRORS can be used to store discovered explicit errors.           |
+| ERRORS and NERRS can be used to store discovered explicit         |
+| errors.                                                           |
 `------------------------------------------------------------------*/
 
 static void
-resolve_sr_conflict (state *s, int ruleno, symbol **errors)
+resolve_sr_conflict (state *s, int ruleno, symbol **errors, int *nerrs)
 {
   symbol_number i;
   reductions *reds = s->reductions;
@@ -188,7 +265,6 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
   rule *redrule = reds->rules[ruleno];
   int redprec = redrule->prec->prec;
   bitset lookahead_tokens = reds->lookahead_tokens[ruleno];
-  int nerrs = 0;
 
   for (i = 0; i < ntokens; i++)
     if (bitset_test (lookahead_tokens, i)
@@ -209,16 +285,21 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
            flush_reduce (lookahead_tokens, i);
          }
        else
-         /* Matching precedence levels.
-            For left association, keep only the reduction.
-            For right association, keep only the shift.
-            For nonassociation, keep neither.  */
+          /* Matching precedence levels.
+             For non-defined associativity, keep both: unexpected
+             associativity conflict.
+             For left associativity, keep only the reduction.
+             For right associativity, keep only the shift.
+             For nonassociativity, keep neither.  */
 
          switch (symbols[i]->assoc)
            {
-           default:
+            case undef_assoc:
              abort ();
 
+            case precedence_assoc:
+              break;
+
            case right_assoc:
              log_resolution (redrule, i, right_resolution);
              flush_reduce (lookahead_tokens, i);
@@ -234,23 +315,10 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
              flush_shift (s, i);
              flush_reduce (lookahead_tokens, i);
              /* Record an explicit error for this token.  */
-             errors[nerrs++] = symbols[i];
+             errors[(*nerrs)++] = symbols[i];
              break;
            }
       }
-
-  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');
-      s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
-    }
 }
 
 
@@ -267,6 +335,7 @@ set_conflicts (state *s, symbol **errors)
   int i;
   transitions *trans = s->transitions;
   reductions *reds = s->reductions;
+  int nerrs = 0;
 
   if (s->consistent)
     return;
@@ -282,7 +351,24 @@ set_conflicts (state *s, symbol **errors)
   for (i = 0; i < reds->num; ++i)
     if (reds->rules[i]->prec && reds->rules[i]->prec->prec
        && !bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
-      resolve_sr_conflict (s, i, errors);
+      resolve_sr_conflict (s, i, errors, &nerrs);
+
+  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');
+      s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
+    }
+  if (obstack_object_size (&solved_conflicts_xml_obstack))
+    {
+      obstack_1grow (&solved_conflicts_xml_obstack, '\0');
+      s->solved_conflicts_xml = obstack_finish (&solved_conflicts_xml_obstack);
+    }
 
   /* Loop over all rules which require lookahead in this state.  Check
      for conflicts not resolved above.  */
@@ -290,7 +376,6 @@ set_conflicts (state *s, symbol **errors)
     {
       if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
        conflicts[s->number] = 1;
-
       bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
     }
 }
@@ -312,6 +397,7 @@ conflicts_solve (void)
   shift_set = bitset_create (ntokens, BITSET_FIXED);
   lookahead_set = bitset_create (ntokens, BITSET_FIXED);
   obstack_init (&solved_conflicts_obstack);
+  obstack_init (&solved_conflicts_xml_obstack);
 
   for (i = 0; i < nstates; i++)
     {
@@ -331,7 +417,8 @@ void
 conflicts_update_state_numbers (state_number old_to_new[],
                                 state_number nstates_old)
 {
-  for (state_number i = 0; i < nstates_old; ++i)
+  state_number i;
+  for (i = 0; i < nstates_old; ++i)
     if (old_to_new[i] != nstates_old)
       conflicts[old_to_new[i]] = conflicts[i];
 }
@@ -542,4 +629,5 @@ conflicts_free (void)
   bitset_free (shift_set);
   bitset_free (lookahead_set);
   obstack_free (&solved_conflicts_obstack, NULL);
+  obstack_free (&solved_conflicts_xml_obstack, NULL);
 }