Change @dircategory from "GNU programming tools" to "Software development".

[bison.git] / src / lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index 2c0c942aeb216ab26c958efa11b616a5c0753de3..e69c05c75d972c7d94bf1d4009325ad1482c88d7 100644 (file)
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -1,5 +1,6 @@
-/* Compute look-ahead criteria for bison,
-   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002
+/* Compute look-ahead criteria for Bison.
+
+   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2003, 2004

    Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
    Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.


@@ -21,35 +22,37 @@
 
 
 /* Compute how to make the finite state machine deterministic; find
 
 
 /* Compute how to make the finite state machine deterministic; find

-   which rules need lookahead in each state, and which lookahead
+   which rules need look-ahead in each state, and which look-ahead

    tokens they accept.  */
 
 #include "system.h"
    tokens they accept.  */
 
 #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 +68,8 @@ 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;

 
 
 
 
 
 


@@ -74,59 +77,61 @@ 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)
-           fatal (_("too many gotos (max %d)"), GOTO_NUMBER_MAX);
-

          ngotos++;
          ngotos++;

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

 }
 
 
 }
 
 


@@ -135,50 +140,48 @@ 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;

 
 

-  while (low <= high)
+  for (;;)

     {
     {

+      if (high < low)
+       abort ();

       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;
     }

-
-  assert (0);
-  /* NOTREACHED */
-  return 0;

 }
 
 
 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)


@@ -186,16 +189,18 @@ 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;
        }
     }


@@ -203,21 +208,21 @@ 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->look_ahead_tokens - LA) + ri];

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

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

 }
 
 
 }
 
 


@@ -225,66 +230,68 @@ 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 *rp;
+         state *s = states[from_state[i]];
+         states1[0] = s->number;

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

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


@@ -294,22 +301,22 @@ 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_look_ahead_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)


@@ -317,117 +324,117 @@ 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 look-ahead tokens required for S |
+| (N_LOOK_AHEAD_TOKENS member).                        |
+`-----------------------------------------------------*/

 
 static int
 
 static int

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

 {
   int k;
 {
   int k;

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

 
 

-  /* We need a lookahead either to distinguish different
+  /* We need a look-ahead 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'.  */
   if (rp->num > 1
       || (rp->num == 1 && sp->num &&
          !TRANSITION_IS_DISABLED (sp, 0) && TRANSITION_IS_SHIFT (sp, 0)))
      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'.  */
   if (rp->num > 1
       || (rp->num == 1 && sp->num &&
          !TRANSITION_IS_DISABLED (sp, 0) && TRANSITION_IS_SHIFT (sp, 0)))

-    nlookaheads += rp->num;
+    n_look_ahead_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_look_ahead_tokens;

 }
 
 
 }
 
 

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

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

-  state_number_t i;
+  state_number i;

   bitsetv pLA;
 
   bitsetv pLA;
 

-  /* Compute the total number of reductions requiring a lookahead.  */
+  /* Compute the total number of reductions requiring a look-ahead.  */

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

-    nLA += state_lookaheads_count (states[i]);
+    nLA += state_look_ahead_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 LOOK_AHEAD_TOKENS for each state whose reductions
+     require look-ahead tokens.  */

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

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

       if (count)
        {
       if (count)
        {

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

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

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

 
 static void
 
 static void

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

 {
 {

-  state_number_t i;
+  state_number i;

   int j, k;
   int j, k;

-  fprintf (out, "Lookaheads: BEGIN\n");
+  fprintf (out, "Look-ahead 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_look_ahead_tokens = 0;

 
 

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

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

-         if (reds->lookaheads[k])
-           ++nlookaheads;
+         if (reds->look_ahead_tokens[k])
+           ++n_look_ahead_tokens;

 
 

-      fprintf (out, "State %d: %d lookaheads\n",
-              i, nlookaheads);
+      fprintf (out, "State %d: %d look-ahead tokens\n",
+              i, n_look_ahead_tokens);

 
 

-      if (reds->lookaheads)
+      if (reds->look_ahead_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->look_ahead_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, "Look-ahead tokens: END\n");

 }
 
 void
 }
 
 void


@@ -438,18 +445,18 @@ lalr (void)
   initialize_F ();
   build_relations ();
   compute_FOLLOWS ();
   initialize_F ();
   build_relations ();
   compute_FOLLOWS ();

-  compute_lookaheads ();
+  compute_look_ahead_tokens ();

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

-    lookaheads_print (stderr);
+    look_ahead_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->look_ahead_tokens = NULL;

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