2007-02-07 Paolo Bonzini <bonzini@gnu.org>

[bison.git] / src / lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index a549e5b43061ce28977cc4cfcb53b57c1ec7dae4..f2bfa96738f2b4e5b1dcce61486bc4381c779064 100644 (file)
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -1,6 +1,7 @@
-/* Compute look-ahead criteria for bison,
-   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002
-   Free Software Foundation, Inc.
+/* Compute lookahead criteria for Bison.
+
+   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2003, 2004, 2005,
+   2006 Free Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 


@@ -16,40 +17,43 @@
 
    You should have received a copy of the GNU General Public License
    along with Bison; see the file COPYING.  If not, write to
 
    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.  */
+   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */

 
 
 /* Compute how to make the finite state machine deterministic; find
    which rules need lookahead in each state, and which lookahead
    tokens they accept.  */
 
 
 
 /* Compute how to make the finite state machine deterministic; find
    which rules need lookahead in each state, and which lookahead
    tokens they accept.  */
 

+#include <config.h>

 #include "system.h"
 #include "system.h"

-#include "bitset.h"
-#include "bitsetv.h"
-#include "relation.h"
-#include "quotearg.h"
-#include "symtab.h"
-#include "gram.h"
-#include "reader.h"
+
+#include <bitset.h>
+#include <bitsetv.h>
+#include <quotearg.h>
+

 #include "LR0.h"
 #include "complain.h"
 #include "LR0.h"
 #include "complain.h"

-#include "lalr.h"
-#include "nullable.h"

 #include "derives.h"
 #include "getargs.h"
 #include "derives.h"
 #include "getargs.h"

+#include "gram.h"
+#include "lalr.h"
+#include "nullable.h"
+#include "reader.h"
+#include "relation.h"
+#include "symtab.h"

 
 

-goto_number_t *goto_map = NULL;
-static goto_number_t ngotos = 0;
-state_number_t *from_state = NULL;
-state_number_t *to_state = NULL;
+goto_number *goto_map;
+static goto_number ngotos;
+state_number *from_state;
+state_number *to_state;

 
 /* Linked list of goto numbers.  */
 
 /* Linked list of goto numbers.  */

-typedef struct goto_list_s
+typedef struct goto_list

 {
 {

-  struct goto_list_s *next;
-  goto_number_t value;
-} goto_list_t;
+  struct goto_list *next;
+  goto_number value;
+} goto_list;

 
 
 /* LA is a LR by NTOKENS matrix of bits.  LA[l, i] is 1 if the rule
 
 
 /* LA is a LR by NTOKENS matrix of bits.  LA[l, i] is 1 if the rule


@@ -65,8 +69,8 @@ size_t nLA;
    comment is hardly needed.  <grin>.  */
 static bitsetv F = NULL;
 
    comment is hardly needed.  <grin>.  */
 static bitsetv F = NULL;
 

-static goto_number_t **includes;
-static goto_list_t **lookback;
+static goto_number **includes;
+static goto_list **lookback;

 
 
 
 
 
 


@@ -74,58 +78,60 @@ static goto_list_t **lookback;
 static void
 set_goto_map (void)
 {
 static void
 set_goto_map (void)
 {

-  state_number_t state;
-  goto_number_t *temp_map;
+  state_number s;
+  goto_number *temp_map;

 
 

-  goto_map = XCALLOC (goto_number_t, nvars + 1) - ntokens;
-  temp_map = XCALLOC (goto_number_t, nvars + 1) - ntokens;
+  goto_map = xcalloc (nvars + 1, sizeof *goto_map);
+  temp_map = xnmalloc (nvars + 1, sizeof *temp_map);

 
   ngotos = 0;
 
   ngotos = 0;

-  for (state = 0; state < nstates; ++state)
+  for (s = 0; s < nstates; ++s)

     {
     {

-      transitions_t *sp = states[state]->transitions;
+      transitions *sp = states[s]->transitions;

       int i;
       for (i = sp->num - 1; i >= 0 && TRANSITION_IS_GOTO (sp, i); --i)
        {
       int i;
       for (i = sp->num - 1; i >= 0 && TRANSITION_IS_GOTO (sp, i); --i)
        {

-         if (ngotos >= GOTO_NUMBER_MAX)
-           abort ();

          ngotos++;
          ngotos++;

-         goto_map[TRANSITION_SYMBOL (sp, i)]++;
+
+         /* Abort if (ngotos + 1) would overflow.  */
+         aver (ngotos != GOTO_NUMBER_MAXIMUM);
+
+         goto_map[TRANSITION_SYMBOL (sp, i) - ntokens]++;

        }
     }
 
   {
        }
     }
 
   {

-    int k = 0;
+    goto_number k = 0;

     int i;
     for (i = ntokens; i < nsyms; i++)
       {
     int i;
     for (i = ntokens; i < nsyms; i++)
       {

-       temp_map[i] = k;
-       k += goto_map[i];
+       temp_map[i - ntokens] = k;
+       k += goto_map[i - ntokens];

       }
 
     for (i = ntokens; i < nsyms; i++)
       }
 
     for (i = ntokens; i < nsyms; i++)

-      goto_map[i] = temp_map[i];
+      goto_map[i - ntokens] = temp_map[i - ntokens];

 
 

-    goto_map[nsyms] = ngotos;
-    temp_map[nsyms] = ngotos;
+    goto_map[nsyms - ntokens] = ngotos;
+    temp_map[nsyms - ntokens] = ngotos;

   }
 
   }
 

-  from_state = XCALLOC (state_number_t, ngotos);
-  to_state = XCALLOC (state_number_t, ngotos);
+  from_state = xcalloc (ngotos, sizeof *from_state);
+  to_state = xcalloc (ngotos, sizeof *to_state);

 
 

-  for (state = 0; state < nstates; ++state)
+  for (s = 0; s < nstates; ++s)

     {
     {

-      transitions_t *sp = states[state]->transitions;
+      transitions *sp = states[s]->transitions;

       int i;
       for (i = sp->num - 1; i >= 0 && TRANSITION_IS_GOTO (sp, i); --i)
        {
       int i;
       for (i = sp->num - 1; i >= 0 && TRANSITION_IS_GOTO (sp, i); --i)
        {

-         int k = temp_map[TRANSITION_SYMBOL (sp, i)]++;
-         from_state[k] = state;
+         goto_number k = temp_map[TRANSITION_SYMBOL (sp, i) - ntokens]++;
+         from_state[k] = s;

          to_state[k] = sp->states[i]->number;
        }
     }
 
          to_state[k] = sp->states[i]->number;
        }
     }
 

-  XFREE (temp_map + ntokens);
+  free (temp_map);

 }
 
 
 }
 
 


@@ -134,26 +140,25 @@ set_goto_map (void)
 | Map a state/symbol pair into its numeric representation.  |
 `----------------------------------------------------------*/
 
 | Map a state/symbol pair into its numeric representation.  |
 `----------------------------------------------------------*/
 

-static int
-map_goto (state_number_t state, symbol_number_t symbol)
+static goto_number
+map_goto (state_number s0, symbol_number sym)

 {
 {

-  int high;
-  int low;
-  int middle;
-  state_number_t s;
+  goto_number high;
+  goto_number low;
+  goto_number middle;
+  state_number s;

 
 

-  low = goto_map[symbol];
-  high = goto_map[symbol + 1] - 1;
+  low = goto_map[sym - ntokens];
+  high = goto_map[sym - ntokens + 1] - 1;

 
   for (;;)
     {
 
   for (;;)
     {

-      if (high < low)
-       abort ();
+      aver (low <= high);

       middle = (low + high) / 2;
       s = from_state[middle];
       middle = (low + high) / 2;
       s = from_state[middle];

-      if (s == state)
+      if (s == s0)

        return middle;
        return middle;

-      else if (s < state)
+      else if (s < s0)

        low = middle + 1;
       else
        high = middle - 1;
        low = middle + 1;
       else
        high = middle - 1;


@@ -164,18 +169,18 @@ map_goto (state_number_t state, symbol_number_t symbol)
 static void
 initialize_F (void)
 {
 static void
 initialize_F (void)
 {

-  goto_number_t **reads = XCALLOC (goto_number_t *, ngotos);
-  goto_number_t *edge = XCALLOC (goto_number_t, ngotos + 1);
-  int nedges = 0;
+  goto_number **reads = xnmalloc (ngotos, sizeof *reads);
+  goto_number *edge = xnmalloc (ngotos + 1, sizeof *edge);
+  goto_number nedges = 0;

 
 

-  int i;
+  goto_number i;

 
   F = bitsetv_create (ngotos, ntokens, BITSET_FIXED);
 
   for (i = 0; i < ngotos; i++)
     {
 
   F = bitsetv_create (ngotos, ntokens, BITSET_FIXED);
 
   for (i = 0; i < ngotos; i++)
     {

-      state_number_t stateno = to_state[i];
-      transitions_t *sp = states[stateno]->transitions;
+      state_number stateno = to_state[i];
+      transitions *sp = states[stateno]->transitions;

 
       int j;
       FOR_EACH_SHIFT (sp, j)
 
       int j;
       FOR_EACH_SHIFT (sp, j)


@@ -183,16 +188,18 @@ initialize_F (void)
 
       for (; j < sp->num; j++)
        {
 
       for (; j < sp->num; j++)
        {

-         symbol_number_t symbol = TRANSITION_SYMBOL (sp, j);
-         if (nullable[symbol])
-           edge[nedges++] = map_goto (stateno, symbol);
+         symbol_number sym = TRANSITION_SYMBOL (sp, j);
+         if (nullable[sym - ntokens])
+           edge[nedges++] = map_goto (stateno, sym);

        }
 
        }
 

-      if (nedges)
+      if (nedges == 0)
+       reads[i] = NULL;
+      else

        {
        {

-         reads[i] = XCALLOC (goto_number_t, nedges + 1);
-         memcpy (reads[i], edge, nedges * sizeof (edge[0]));
-         reads[i][nedges] = -1;
+         reads[i] = xnmalloc (nedges + 1, sizeof reads[i][0]);
+         memcpy (reads[i], edge, nedges * sizeof edge[0]);
+         reads[i][nedges] = END_NODE;

          nedges = 0;
        }
     }
          nedges = 0;
        }
     }


@@ -200,21 +207,21 @@ initialize_F (void)
   relation_digraph (reads, ngotos, &F);
 
   for (i = 0; i < ngotos; i++)
   relation_digraph (reads, ngotos, &F);
 
   for (i = 0; i < ngotos; i++)

-    XFREE (reads[i]);
+    free (reads[i]);

 
 

-  XFREE (reads);
-  XFREE (edge);
+  free (reads);
+  free (edge);

 }
 
 
 static void
 }
 
 
 static void

-add_lookback_edge (state_t *state, rule_t *rule, int gotono)
+add_lookback_edge (state *s, rule *r, goto_number gotono)

 {
 {

-  int r = state_reduction_find (state, rule);
-  goto_list_t *sp = XCALLOC (goto_list_t, 1);
-  sp->next = lookback[(state->reductions->lookaheads - LA) + r];
+  int ri = state_reduction_find (s, r);
+  goto_list *sp = xmalloc (sizeof *sp);
+  sp->next = lookback[(s->reductions->lookahead_tokens - LA) + ri];

   sp->value = gotono;
   sp->value = gotono;

-  lookback[(state->reductions->lookaheads - LA) + r] = sp;
+  lookback[(s->reductions->lookahead_tokens - LA) + ri] = sp;

 }
 
 
 }
 
 


@@ -222,66 +229,70 @@ add_lookback_edge (state_t *state, rule_t *rule, int gotono)
 static void
 build_relations (void)
 {
 static void
 build_relations (void)
 {

-  goto_number_t *edge = XCALLOC (goto_number_t, ngotos + 1);
-  state_number_t *states1 = XCALLOC (state_number_t, ritem_longest_rhs () + 1);
-  int i;
+  goto_number *edge = xnmalloc (ngotos + 1, sizeof *edge);
+  state_number *states1 = xnmalloc (ritem_longest_rhs () + 1, sizeof *states1);
+  goto_number i;

 
 

-  includes = XCALLOC (goto_number_t *, ngotos);
+  includes = xnmalloc (ngotos, sizeof *includes);

 
   for (i = 0; i < ngotos; i++)
     {
       int nedges = 0;
 
   for (i = 0; i < ngotos; i++)
     {
       int nedges = 0;

-      symbol_number_t symbol1 = states[to_state[i]]->accessing_symbol;
-      rule_t **rulep;
+      symbol_number symbol1 = states[to_state[i]]->accessing_symbol;
+      rule **rulep;

 
 

-      for (rulep = derives[symbol1]; *rulep; rulep++)
+      for (rulep = derives[symbol1 - ntokens]; *rulep; rulep++)

        {
        {

-         int done;
+         bool done;

          int length = 1;
          int length = 1;

-         item_number_t *rp;
-         state_t *state = states[from_state[i]];
-         states1[0] = state->number;
+         item_number const *rp;
+         state *s = states[from_state[i]];
+         states1[0] = s->number;

 
 

-         for (rp = (*rulep)->rhs; *rp >= 0; rp++)
+         for (rp = (*rulep)->rhs; ! item_number_is_rule_number (*rp); rp++)

            {
            {

-             state = transitions_to (state->transitions,
-                                     item_number_as_symbol_number (*rp));
-             states1[length++] = state->number;
+             s = transitions_to (s->transitions,
+                                 item_number_as_symbol_number (*rp));
+             states1[length++] = s->number;

            }
 
            }
 

-         if (!state->consistent)
-           add_lookback_edge (state, *rulep, i);
+         if (!s->consistent)
+           add_lookback_edge (s, *rulep, i);

 
          length--;
 
          length--;

-         done = 0;
+         done = false;

          while (!done)
            {
          while (!done)
            {

-             done = 1;
+             done = true;
+             /* Each rhs ends in an item number, and there is a
+                sentinel before the first rhs, so it is safe to
+                decrement RP here.  */

              rp--;
              rp--;

-             /* JF added rp>=ritem &&   I hope to god its right! */
-             if (rp >= ritem && ISVAR (*rp))
+             if (ISVAR (*rp))

                {
                {

-                 /* Downcasting from item_number_t to symbol_number_t. */
+                 /* Downcasting from item_number to symbol_number.  */

                  edge[nedges++] = map_goto (states1[--length],
                                             item_number_as_symbol_number (*rp));
                  edge[nedges++] = map_goto (states1[--length],
                                             item_number_as_symbol_number (*rp));

-                 if (nullable[*rp])
-                   done = 0;
+                 if (nullable[*rp - ntokens])
+                   done = false;

                }
            }
        }
 
                }
            }
        }
 

-      if (nedges)
+      if (nedges == 0)
+       includes[i] = NULL;
+      else

        {
          int j;
        {
          int j;

-         includes[i] = XCALLOC (goto_number_t, nedges + 1);
+         includes[i] = xnmalloc (nedges + 1, sizeof includes[i][0]);

          for (j = 0; j < nedges; j++)
            includes[i][j] = edge[j];
          for (j = 0; j < nedges; j++)
            includes[i][j] = edge[j];

-         includes[i][nedges] = -1;
+         includes[i][nedges] = END_NODE;

        }
     }
 
        }
     }
 

-  XFREE (edge);
-  XFREE (states1);
+  free (edge);
+  free (states1);

 
   relation_transpose (&includes, ngotos);
 }
 
   relation_transpose (&includes, ngotos);
 }


@@ -291,22 +302,22 @@ build_relations (void)
 static void
 compute_FOLLOWS (void)
 {
 static void
 compute_FOLLOWS (void)
 {

-  int i;
+  goto_number i;

 
   relation_digraph (includes, ngotos, &F);
 
   for (i = 0; i < ngotos; i++)
 
   relation_digraph (includes, ngotos, &F);
 
   for (i = 0; i < ngotos; i++)

-    XFREE (includes[i]);
+    free (includes[i]);

 
 

-  XFREE (includes);
+  free (includes);

 }
 
 
 static void
 }
 
 
 static void

-compute_lookaheads (void)
+compute_lookahead_tokens (void)

 {
   size_t i;
 {
   size_t i;

-  goto_list_t *sp;
+  goto_list *sp;

 
   for (i = 0; i < nLA; i++)
     for (sp = lookback[i]; sp; sp = sp->next)
 
   for (i = 0; i < nLA; i++)
     for (sp = lookback[i]; sp; sp = sp->next)


@@ -314,25 +325,25 @@ compute_lookaheads (void)
 
   /* Free LOOKBACK. */
   for (i = 0; i < nLA; i++)
 
   /* Free LOOKBACK. */
   for (i = 0; i < nLA; i++)

-    LIST_FREE (goto_list_t, lookback[i]);
+    LIST_FREE (goto_list, lookback[i]);

 
 

-  XFREE (lookback);
+  free (lookback);

   bitsetv_free (F);
 }
 
 
   bitsetv_free (F);
 }
 
 

-/*---------------------------------------------------------------.
-| Count the number of lookaheads required for STATE (NLOOKAHEADS |
-| member).                                                       |
-`---------------------------------------------------------------*/
+/*----------------------------------------------------.
+| Count the number of lookahead tokens required for S |
+| (N_LOOKAHEAD_TOKENS member).                        |
+`----------------------------------------------------*/

 
 static int
 
 static int

-state_lookaheads_count (state_t *state)
+state_lookahead_tokens_count (state *s)

 {
   int k;
 {
   int k;

-  int nlookaheads = 0;
-  reductions_t *rp = state->reductions;
-  transitions_t *sp = state->transitions;
+  int n_lookahead_tokens = 0;
+  reductions *rp = s->reductions;
+  transitions *sp = s->transitions;

 
   /* We need a lookahead either to distinguish different
      reductions (i.e., there are two or more), or to distinguish a
 
   /* We need a lookahead either to distinguish different
      reductions (i.e., there are two or more), or to distinguish a


@@ -341,90 +352,90 @@ state_lookaheads_count (state_t *state)
   if (rp->num > 1
       || (rp->num == 1 && sp->num &&
          !TRANSITION_IS_DISABLED (sp, 0) && TRANSITION_IS_SHIFT (sp, 0)))
   if (rp->num > 1
       || (rp->num == 1 && sp->num &&
          !TRANSITION_IS_DISABLED (sp, 0) && TRANSITION_IS_SHIFT (sp, 0)))

-    nlookaheads += rp->num;
+    n_lookahead_tokens += rp->num;

   else
   else

-    state->consistent = 1;
+    s->consistent = 1;

 
   for (k = 0; k < sp->num; k++)
     if (!TRANSITION_IS_DISABLED (sp, k) && TRANSITION_IS_ERROR (sp, k))
       {
 
   for (k = 0; k < sp->num; k++)
     if (!TRANSITION_IS_DISABLED (sp, k) && TRANSITION_IS_ERROR (sp, k))
       {

-       state->consistent = 0;
+       s->consistent = 0;

        break;
       }
 
        break;
       }
 

-  return nlookaheads;
+  return n_lookahead_tokens;

 }
 
 
 }
 
 

-/*----------------------------------------------.
-| Compute LA, NLA, and the lookaheads members.  |
-`----------------------------------------------*/
+/*----------------------------------------------------.
+| Compute LA, NLA, and the lookahead_tokens members.  |
+`----------------------------------------------------*/

 
 static void
 initialize_LA (void)
 {
 
 static void
 initialize_LA (void)
 {

-  state_number_t i;
+  state_number i;

   bitsetv pLA;
 
   /* Compute the total number of reductions requiring a lookahead.  */
   nLA = 0;
   for (i = 0; i < nstates; i++)
   bitsetv pLA;
 
   /* Compute the total number of reductions requiring a lookahead.  */
   nLA = 0;
   for (i = 0; i < nstates; i++)

-    nLA += state_lookaheads_count (states[i]);
+    nLA += state_lookahead_tokens_count (states[i]);

   /* Avoid having to special case 0.  */
   if (!nLA)
     nLA = 1;
 
   pLA = LA = bitsetv_create (nLA, ntokens, BITSET_FIXED);
   /* Avoid having to special case 0.  */
   if (!nLA)
     nLA = 1;
 
   pLA = LA = bitsetv_create (nLA, ntokens, BITSET_FIXED);

-  lookback = XCALLOC (goto_list_t *, nLA);
+  lookback = xcalloc (nLA, sizeof *lookback);

 
 

-  /* Initialize the members LOOKAHEADS for each state which reductions
-     require lookaheads.  */
+  /* Initialize the members LOOKAHEAD_TOKENS for each state whose reductions
+     require lookahead tokens.  */

   for (i = 0; i < nstates; i++)
     {
   for (i = 0; i < nstates; i++)
     {

-      int count = state_lookaheads_count (states[i]);
+      int count = state_lookahead_tokens_count (states[i]);

       if (count)
        {
       if (count)
        {

-         states[i]->reductions->lookaheads = pLA;
+         states[i]->reductions->lookahead_tokens = pLA;

          pLA += count;
        }
     }
 }
 
 
          pLA += count;
        }
     }
 }
 
 

-/*---------------------------------------.
-| Output the lookaheads for each state.  |
-`---------------------------------------*/
+/*---------------------------------------------.
+| Output the lookahead tokens for each state.  |
+`---------------------------------------------*/

 
 static void
 
 static void

-lookaheads_print (FILE *out)
+lookahead_tokens_print (FILE *out)

 {
 {

-  state_number_t i;
+  state_number i;

   int j, k;
   int j, k;

-  fprintf (out, "Lookaheads: BEGIN\n");
+  fprintf (out, "Lookahead tokens: BEGIN\n");

   for (i = 0; i < nstates; ++i)
     {
   for (i = 0; i < nstates; ++i)
     {

-      reductions_t *reds = states[i]->reductions;
+      reductions *reds = states[i]->reductions;

       bitset_iterator iter;
       bitset_iterator iter;

-      int nlookaheads = 0;
+      int n_lookahead_tokens = 0;

 
 

-      if (reds->lookaheads)
+      if (reds->lookahead_tokens)

        for (k = 0; k < reds->num; ++k)
        for (k = 0; k < reds->num; ++k)

-         if (reds->lookaheads[k])
-           ++nlookaheads;
+         if (reds->lookahead_tokens[k])
+           ++n_lookahead_tokens;

 
 

-      fprintf (out, "State %d: %d lookaheads\n",
-              i, nlookaheads);
+      fprintf (out, "State %d: %d lookahead tokens\n",
+              i, n_lookahead_tokens);

 
 

-      if (reds->lookaheads)
+      if (reds->lookahead_tokens)

        for (j = 0; j < reds->num; ++j)
        for (j = 0; j < reds->num; ++j)

-         BITSET_FOR_EACH (iter, reds->lookaheads[j], k, 0)
+         BITSET_FOR_EACH (iter, reds->lookahead_tokens[j], k, 0)

          {
            fprintf (out, "   on %d (%s) -> rule %d\n",
                     k, symbols[k]->tag,
                     reds->rules[j]->number);
          };
     }
          {
            fprintf (out, "   on %d (%s) -> rule %d\n",
                     k, symbols[k]->tag,
                     reds->rules[j]->number);
          };
     }

-  fprintf (out, "Lookaheads: END\n");
+  fprintf (out, "Lookahead tokens: END\n");

 }
 
 void
 }
 
 void


@@ -435,18 +446,18 @@ lalr (void)
   initialize_F ();
   build_relations ();
   compute_FOLLOWS ();
   initialize_F ();
   build_relations ();
   compute_FOLLOWS ();

-  compute_lookaheads ();
+  compute_lookahead_tokens ();

 
   if (trace_flag & trace_sets)
 
   if (trace_flag & trace_sets)

-    lookaheads_print (stderr);
+    lookahead_tokens_print (stderr);

 }
 
 
 void
 lalr_free (void)
 {
 }
 
 
 void
 lalr_free (void)
 {

-  state_number_t s;
+  state_number s;

   for (s = 0; s < nstates; ++s)
   for (s = 0; s < nstates; ++s)

-    states[s]->reductions->lookaheads = NULL;
+    states[s]->reductions->lookahead_tokens = NULL;

   bitsetv_free (LA);
 }
   bitsetv_free (LA);
 }