Fix some memory leaks.

[bison.git] / src / lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index 27866ecf3adbd5479d84d6a6f3e4c304f8df63a8..fbd2800f0529905c30cd990bf30480c1e1fb75ed 100644 (file)
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -43,9 +43,10 @@
 #include "symtab.h"
 
 goto_number *goto_map;
-static goto_number ngotos;
+goto_number ngotos;
 state_number *from_state;
 state_number *to_state;
+bitsetv goto_follows = NULL;
 
 /* Linked list of goto numbers.  */
 typedef struct goto_list
@@ -64,17 +65,13 @@ static bitsetv LA = NULL;
 size_t nLA;
 
 
-/* And for the famous F variable, which name is so descriptive that a
-   comment is hardly needed.  <grin>.  */
-static bitsetv F = NULL;
-
 static goto_number **includes;
 static goto_list **lookback;
 
 
 
 
-static void
+void
 set_goto_map (void)
 {
   state_number s;
@@ -134,12 +131,7 @@ set_goto_map (void)
 }
 
 
-
-/*----------------------------------------------------------.
-| Map a state/symbol pair into its numeric representation.  |
-`----------------------------------------------------------*/
-
-static goto_number
+goto_number
 map_goto (state_number s0, symbol_number sym)
 {
   goto_number high;
@@ -174,7 +166,7 @@ initialize_F (void)
 
   goto_number i;
 
-  F = bitsetv_create (ngotos, ntokens, BITSET_FIXED);
+  goto_follows = bitsetv_create (ngotos, ntokens, BITSET_FIXED);
 
   for (i = 0; i < ngotos; i++)
     {
@@ -183,7 +175,7 @@ initialize_F (void)
 
       int j;
       FOR_EACH_SHIFT (sp, j)
-       bitset_set (F[i], TRANSITION_SYMBOL (sp, j));
+       bitset_set (goto_follows[i], TRANSITION_SYMBOL (sp, j));
 
       for (; j < sp->num; j++)
        {
@@ -203,7 +195,7 @@ initialize_F (void)
        }
     }
 
-  relation_digraph (reads, ngotos, &F);
+  relation_digraph (reads, ngotos, &goto_follows);
 
   for (i = 0; i < ngotos; i++)
     free (reads[i]);
@@ -264,7 +256,7 @@ build_relations (void)
            {
              done = true;
              /* Each rhs ends in a rule number, and there is a
-                sentinel before the first rhs, so it is safe to
+                sentinel (ritem[-1]=0) before the first rhs, so it is safe to
                 decrement RP here.  */
              rp--;
              if (ISVAR (*rp))
@@ -303,7 +295,7 @@ compute_FOLLOWS (void)
 {
   goto_number i;
 
-  relation_digraph (includes, ngotos, &F);
+  relation_digraph (includes, ngotos, &goto_follows);
 
   for (i = 0; i < ngotos; i++)
     free (includes[i]);
@@ -320,14 +312,13 @@ compute_lookahead_tokens (void)
 
   for (i = 0; i < nLA; i++)
     for (sp = lookback[i]; sp; sp = sp->next)
-      bitset_or (LA[i], LA[i], F[sp->value]);
+      bitset_or (LA[i], LA[i], goto_follows[sp->value]);
 
   /* Free LOOKBACK. */
   for (i = 0; i < nLA; i++)
     LIST_FREE (goto_list, lookback[i]);
 
   free (lookback);
-  bitsetv_free (F);
 }
 
 
@@ -337,7 +328,7 @@ compute_lookahead_tokens (void)
 `----------------------------------------------------*/
 
 static int
-state_lookahead_tokens_count (state *s, bool default_rule_only_for_accept)
+state_lookahead_tokens_count (state *s, bool default_reduction_only_for_accept)
 {
   int n_lookahead_tokens = 0;
   reductions *rp = s->reductions;
@@ -353,14 +344,15 @@ state_lookahead_tokens_count (state *s, bool default_rule_only_for_accept)
   /* We need a lookahead either to distinguish different reductions
      (i.e., there are two or more), or to distinguish a reduction from a
      shift.  Otherwise, it is straightforward, and the state is
-     `consistent'.  However, for states that have any rules, treat only
-     the accepting state as consistent (since there is never a lookahead
-     token that makes sense there, and so no lookahead token should be
-     read) if the user has otherwise disabled default rules.  */
+     `consistent'.  However, do not treat a state with any reductions as
+     consistent unless it is the accepting state (because there is never
+     a lookahead token that makes sense there, and so no lookahead token
+     should be read) if the user has otherwise disabled default
+     reductions.  */
   if (rp->num > 1
       || (rp->num == 1 && sp->num && TRANSITION_IS_SHIFT (sp, 0))
       || (rp->num == 1 && rp->rules[0]->number != 0
-          && default_rule_only_for_accept))
+          && default_reduction_only_for_accept))
     n_lookahead_tokens += rp->num;
   else
     s->consistent = 1;
@@ -373,36 +365,39 @@ state_lookahead_tokens_count (state *s, bool default_rule_only_for_accept)
 | Compute LA, NLA, and the lookahead_tokens members.  |
 `----------------------------------------------------*/
 
-static void
+void
 initialize_LA (void)
 {
   state_number i;
   bitsetv pLA;
-  bool default_rule_only_for_accept;
+  bool default_reduction_only_for_accept;
   {
-    char *default_rules = muscle_percent_define_get ("lr.default_rules");
-    default_rule_only_for_accept = 0 == strcmp (default_rules, "accepting");
-    free (default_rules);
+    char *default_reductions =
+      muscle_percent_define_get ("lr.default-reductions");
+    default_reduction_only_for_accept =
+      0 == strcmp (default_reductions, "accepting");
+    free (default_reductions);
   }
 
   /* Compute the total number of reductions requiring a lookahead.  */
   nLA = 0;
   for (i = 0; i < nstates; i++)
     nLA +=
-      state_lookahead_tokens_count (states[i], default_rule_only_for_accept);
+      state_lookahead_tokens_count (states[i],
+                                    default_reduction_only_for_accept);
   /* Avoid having to special case 0.  */
   if (!nLA)
     nLA = 1;
 
   pLA = LA = bitsetv_create (nLA, ntokens, BITSET_FIXED);
-  lookback = xcalloc (nLA, sizeof *lookback);
 
   /* Initialize the members LOOKAHEAD_TOKENS for each state whose reductions
      require lookahead tokens.  */
   for (i = 0; i < nstates; i++)
     {
       int count =
-        state_lookahead_tokens_count (states[i], default_rule_only_for_accept);
+        state_lookahead_tokens_count (states[i],
+                                      default_reduction_only_for_accept);
       if (count)
        {
          states[i]->reductions->lookahead_tokens = pLA;
@@ -454,6 +449,7 @@ lalr (void)
   initialize_LA ();
   set_goto_map ();
   initialize_F ();
+  lookback = xcalloc (nLA, sizeof *lookback);
   build_relations ();
   compute_FOLLOWS ();
   compute_lookahead_tokens ();