Point to an official beta.

[bison.git] / src / lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index 3851350bdfce5482587ae71803ebf86196c92c8f..643f8fd91d20ab78bf6f460dde57cd424e8f67d1 100644 (file)
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -1,5 +1,6 @@
 /* Compute look-ahead criteria for bison,
 /* Compute look-ahead criteria for bison,

-   Copyright 1984, 1986, 1989, 2000, 2001  Free Software Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002
+   Free Software Foundation, Inc.

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


@@ -24,9 +25,14 @@
    tokens they accept.  */
 
 #include "system.h"
    tokens they accept.  */
 
 #include "system.h"

+#include "bitset.h"
+#include "bitsetv.h"
+#include "quotearg.h"
+#include "symtab.h"
+#include "gram.h"
+#include "reader.h"

 #include "types.h"
 #include "LR0.h"
 #include "types.h"
 #include "LR0.h"

-#include "gram.h"

 #include "complain.h"
 #include "lalr.h"
 #include "nullable.h"
 #include "complain.h"
 #include "lalr.h"
 #include "nullable.h"


@@ -34,22 +40,20 @@
 #include "getargs.h"
 
 /* All the decorated states, indexed by the state number.  */
 #include "getargs.h"
 
 /* All the decorated states, indexed by the state number.  */

-state_t **state_table = NULL;
+state_t **states = NULL;

 
 

-int tokensetsize;
-short *LAruleno;
-unsigned *LA;
+rule_t **LArule = NULL;
+bitsetv LA = NULL;

 size_t nLA;
 
 static int ngotos;
 size_t nLA;
 
 static int ngotos;

-short *goto_map;
-short *from_state;
-short *to_state;
+short *goto_map = NULL;
+short *from_state = NULL;
+short *to_state = NULL;

 
 /* And for the famous F variable, which name is so descriptive that a
    comment is hardly needed.  <grin>.  */
 
 /* And for the famous F variable, which name is so descriptive that a
    comment is hardly needed.  <grin>.  */

-static unsigned *F = NULL;
-#define F(Rule)  (F + (Rule) * tokensetsize)
+static bitsetv F = NULL;

 
 static short **includes;
 static shorts **lookback;
 
 static short **includes;
 static shorts **lookback;


@@ -72,9 +76,7 @@ static void
 traverse (int i)
 {
   int j;
 traverse (int i)
 {
   int j;

-  size_t k;

   int height;
   int height;

-  size_t size = F (i + 1) - F(i);

 
   VERTICES[++top] = i;
   INDEX[i] = height = top;
 
   VERTICES[++top] = i;
   INDEX[i] = height = top;


@@ -88,8 +90,7 @@ traverse (int i)
        if (INDEX[i] > INDEX[R[i][j]])
          INDEX[i] = INDEX[R[i][j]];
 
        if (INDEX[i] > INDEX[R[i][j]])
          INDEX[i] = INDEX[R[i][j]];
 

-       for (k = 0; k < size; ++k)
-         F (i)[k] |= F (R[i][j])[k];
+       bitset_or (F[i], F[i], F[R[i][j]]);

       }
 
   if (INDEX[i] == height)
       }
 
   if (INDEX[i] == height)


@@ -101,8 +102,7 @@ traverse (int i)
        if (i == j)
          break;
 
        if (i == j)
          break;
 

-       for (k = 0; k < size; ++k)
-         F (j)[k] = F (i)[k];
+       bitset_copy (F[j], F[i]);

       }
 }
 
       }
 }
 


@@ -134,32 +134,31 @@ digraph (short **relation)
 static void
 initialize_LA (void)
 {
 static void
 initialize_LA (void)
 {

-  int i;
+  size_t i;

   int j;
   int j;

-  short *np;
-  reductions *rp;
+  rule_t **np;

 
   /* Avoid having to special case 0.  */
   if (!nLA)
     nLA = 1;
 
 
   /* Avoid having to special case 0.  */
   if (!nLA)
     nLA = 1;
 

-  LA = XCALLOC (unsigned, nLA * tokensetsize);
-  LAruleno = XCALLOC (short, nLA);
+  LA = bitsetv_create (nLA, ntokens, BITSET_FIXED);
+  LArule = XCALLOC (rule_t *, nLA);

   lookback = XCALLOC (shorts *, nLA);
 
   lookback = XCALLOC (shorts *, nLA);
 

-  np = LAruleno;
+  np = LArule;

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

-    if (!state_table[i]->consistent)
-      if ((rp = state_table[i]->reductions))
-       for (j = 0; j < rp->nreds; j++)
-         *np++ = rp->rules[j];
+    if (!states[i]->consistent)
+      for (j = 0; j < states[i]->reductions->nreds; j++)
+       *np++ = &rules[states[i]->reductions->rules[j]];

 }
 
 
 static void
 set_goto_map (void)
 {
 }
 
 
 static void
 set_goto_map (void)
 {

-  int state, i;
+  size_t state;
+  int i;

   short *temp_map;
 
   goto_map = XCALLOC (short, nvars + 1) - ntokens;
   short *temp_map;
 
   goto_map = XCALLOC (short, nvars + 1) - ntokens;


@@ -168,11 +167,11 @@ set_goto_map (void)
   ngotos = 0;
   for (state = 0; state < nstates; ++state)
     {
   ngotos = 0;
   for (state = 0; state < nstates; ++state)
     {

-      shifts *sp = state_table[state]->shifts;
+      shifts *sp = states[state]->shifts;

       for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i)
        {
       for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i)
        {

-         if (ngotos == MAXSHORT)
-           fatal (_("too many gotos (max %d)"), MAXSHORT);
+         if (ngotos == SHRT_MAX)
+           fatal (_("too many gotos (max %d)"), SHRT_MAX);

 
          ngotos++;
          goto_map[SHIFT_SYMBOL (sp, i)]++;
 
          ngotos++;
          goto_map[SHIFT_SYMBOL (sp, i)]++;


@@ -199,7 +198,7 @@ set_goto_map (void)
 
   for (state = 0; state < nstates; ++state)
     {
 
   for (state = 0; state < nstates; ++state)
     {

-      shifts *sp = state_table[state]->shifts;
+      shifts *sp = states[state]->shifts;

       for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i)
        {
          int k = temp_map[SHIFT_SYMBOL (sp, i)]++;
       for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i)
        {
          int k = temp_map[SHIFT_SYMBOL (sp, i)]++;


@@ -218,7 +217,7 @@ set_goto_map (void)
 `----------------------------------------------------------*/
 
 static int
 `----------------------------------------------------------*/
 
 static int

-map_goto (int state, int symbol)
+map_goto (int state, token_number_t symbol)

 {
   int high;
   int low;
 {
   int high;
   int low;


@@ -255,20 +254,20 @@ initialize_F (void)
 
   int i;
 
 
   int i;
 

-  F = XCALLOC (unsigned, ngotos * tokensetsize);
+  F = bitsetv_create (ngotos, ntokens, BITSET_FIXED);

 
   for (i = 0; i < ngotos; i++)
     {
       int stateno = to_state[i];
 
   for (i = 0; i < ngotos; i++)
     {
       int stateno = to_state[i];

-      shifts *sp = state_table[stateno]->shifts;
+      shifts *sp = states[stateno]->shifts;

 
       int j;
       for (j = 0; j < sp->nshifts && SHIFT_IS_SHIFT (sp, j); j++)
 
       int j;
       for (j = 0; j < sp->nshifts && SHIFT_IS_SHIFT (sp, j); j++)

-       SETBIT (F (i), SHIFT_SYMBOL (sp, j));
+       bitset_set (F[i], SHIFT_SYMBOL (sp, j));

 
       for (; j < sp->nshifts; j++)
        {
 
       for (; j < sp->nshifts; j++)
        {

-         int symbol = SHIFT_SYMBOL (sp, j);
+         token_number_t symbol = SHIFT_SYMBOL (sp, j);

          if (nullable[symbol])
            edge[nedges++] = map_goto (stateno, symbol);
        }
          if (nullable[symbol])
            edge[nedges++] = map_goto (stateno, symbol);
        }


@@ -276,7 +275,7 @@ initialize_F (void)
       if (nedges)
        {
          reads[i] = XCALLOC (short, nedges + 1);
       if (nedges)
        {
          reads[i] = XCALLOC (short, nedges + 1);

-         shortcpy (reads[i], edge, nedges);
+         memcpy (reads[i], edge, nedges * sizeof (edge[0]));

          reads[i][nedges] = -1;
          nedges = 0;
        }
          reads[i][nedges] = -1;
          nedges = 0;
        }


@@ -299,10 +298,10 @@ add_lookback_edge (state_t *state, int ruleno, int gotono)
   shorts *sp;
 
   for (i = 0; i < state->nlookaheads; ++i)
   shorts *sp;
 
   for (i = 0; i < state->nlookaheads; ++i)

-    if (LAruleno[state->lookaheadsp + i] == ruleno)
+    if (LArule[state->lookaheadsp + i]->number == ruleno)

       break;
 
       break;
 

-  assert (LAruleno[state->lookaheadsp + i] == ruleno);
+  assert (LArule[state->lookaheadsp + i]->number == ruleno);

 
   sp = XCALLOC (shorts, 1);
   sp->next = lookback[state->lookaheadsp + i];
 
   sp = XCALLOC (shorts, 1);
   sp->next = lookback[state->lookaheadsp + i];


@@ -401,7 +400,7 @@ static void
 build_relations (void)
 {
   short *edge = XCALLOC (short, ngotos + 1);
 build_relations (void)
 {
   short *edge = XCALLOC (short, ngotos + 1);

-  short *states = XCALLOC (short, ritem_longest_rhs () + 1);
+  short *states1 = XCALLOC (short, ritem_longest_rhs () + 1);

   int i;
 
   includes = XCALLOC (short *, ngotos);
   int i;
 
   includes = XCALLOC (short *, ngotos);


@@ -409,29 +408,30 @@ build_relations (void)
   for (i = 0; i < ngotos; i++)
     {
       int nedges = 0;
   for (i = 0; i < ngotos; i++)
     {
       int nedges = 0;

-      int symbol1 = state_table[to_state[i]]->accessing_symbol;
+      token_number_t symbol1 = states[to_state[i]]->accessing_symbol;

       short *rulep;
 
       for (rulep = derives[symbol1]; *rulep > 0; rulep++)
        {
          int done;
          int length = 1;
       short *rulep;
 
       for (rulep = derives[symbol1]; *rulep > 0; rulep++)
        {
          int done;
          int length = 1;

-         short *rp;
-         state_t *state = state_table[from_state[i]];
-         states[0] = state->number;
+         item_number_t *rp;
+         state_t *state = states[from_state[i]];
+         states1[0] = state->number;

 
 

-         for (rp = ritem + rule_table[*rulep].rhs; *rp > 0; rp++)
+         for (rp = rules[*rulep].rhs; *rp >= 0; rp++)

            {
              shifts *sp = state->shifts;
              int j;
              for (j = 0; j < sp->nshifts; j++)
                {
            {
              shifts *sp = state->shifts;
              int j;
              for (j = 0; j < sp->nshifts; j++)
                {

-                 state = state_table[sp->shifts[j]];
-                 if (state->accessing_symbol == *rp)
+                 state = states[sp->shifts[j]];
+                 if (state->accessing_symbol
+                     == item_number_as_token_number (*rp))

                    break;
                }
 
                    break;
                }
 

-             states[length++] = state->number;
+             states1[length++] = state->number;

            }
 
          if (!state->consistent)
            }
 
          if (!state->consistent)


@@ -446,7 +446,9 @@ build_relations (void)
              /* JF added rp>=ritem &&   I hope to god its right! */
              if (rp >= ritem && ISVAR (*rp))
                {
              /* JF added rp>=ritem &&   I hope to god its right! */
              if (rp >= ritem && ISVAR (*rp))
                {

-                 edge[nedges++] = map_goto (states[--length], *rp);
+                 /* Downcasting from item_number_t to token_number_t. */
+                 edge[nedges++] = map_goto (states1[--length],
+                                            item_number_as_token_number (*rp));

                  if (nullable[*rp])
                    done = 0;
                }
                  if (nullable[*rp])
                    done = 0;
                }


@@ -464,7 +466,7 @@ build_relations (void)
     }
 
   XFREE (edge);
     }
 
   XFREE (edge);

-  XFREE (states);
+  XFREE (states1);

 
   includes = transpose (includes, ngotos);
 }
 
   includes = transpose (includes, ngotos);
 }


@@ -493,19 +495,14 @@ compute_lookaheads (void)
 
   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)

-      {
-       int size = LA (i + 1) - LA (i);
-       int j;
-       for (j = 0; j < size; ++j)
-         LA (i)[j] |= F (sp->value)[j];
-      }
+      bitset_or (LA[i], LA[i], F[sp->value]);

 
   /* Free LOOKBACK. */
   for (i = 0; i < nLA; i++)
     LIST_FREE (shorts, lookback[i]);
 
   XFREE (lookback);
 
   /* Free LOOKBACK. */
   for (i = 0; i < nLA; i++)
     LIST_FREE (shorts, lookback[i]);
 
   XFREE (lookback);

-  XFREE (F);
+  bitsetv_free (F);

 }
 
 
 }
 
 


@@ -516,39 +513,67 @@ compute_lookaheads (void)
 static void
 initialize_lookaheads (void)
 {
 static void
 initialize_lookaheads (void)
 {

-  int i;
+  size_t i;

   nLA = 0;
   for (i = 0; i < nstates; i++)
     {
       int k;
       int nlookaheads = 0;
   nLA = 0;
   for (i = 0; i < nstates; i++)
     {
       int k;
       int nlookaheads = 0;

-      reductions *rp = state_table[i]->reductions;
-      shifts *sp = state_table[i]->shifts;
-
-      if (rp
-         && (rp->nreds > 1 || (sp->nshifts && SHIFT_IS_SHIFT (sp, 0))))
+      reductions *rp = states[i]->reductions;
+      shifts *sp = states[i]->shifts;
+
+      /* 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'.  */
+      if (rp->nreds > 1
+         || (rp->nreds == 1 && sp->nshifts && SHIFT_IS_SHIFT (sp, 0)))

        nlookaheads += rp->nreds;
       else
        nlookaheads += rp->nreds;
       else

-       state_table[i]->consistent = 1;
+       states[i]->consistent = 1;

 
       for (k = 0; k < sp->nshifts; k++)
        if (SHIFT_IS_ERROR (sp, k))
          {
 
       for (k = 0; k < sp->nshifts; k++)
        if (SHIFT_IS_ERROR (sp, k))
          {

-           state_table[i]->consistent = 0;
+           states[i]->consistent = 0;

            break;
          }
 
            break;
          }
 

-      state_table[i]->nlookaheads = nlookaheads;
-      state_table[i]->lookaheadsp = nLA;
+      states[i]->nlookaheads = nlookaheads;
+      states[i]->lookaheadsp = nLA;

       nLA += nlookaheads;
     }
 }
 
       nLA += nlookaheads;
     }
 }
 

+
+/*---------------------------------------.
+| Output the lookaheads for each state.  |
+`---------------------------------------*/
+
+static void
+lookaheads_print (FILE *out)
+{
+  size_t i;
+  int j, k;
+  fprintf (out, "Lookaheads: BEGIN\n");
+  for (i = 0; i < nstates; ++i)
+    {
+      fprintf (out, "State %d: %d lookaheads\n",
+              i, states[i]->nlookaheads);
+
+      for (j = 0; j < states[i]->nlookaheads; ++j)
+       for (k = 0; k < ntokens; ++k)
+         if (bitset_test (LA[states[i]->lookaheadsp + j], k))
+           fprintf (out, "   on %d (%s) -> rule %d\n",
+                    k, quotearg_style (escape_quoting_style, symbols[k]->tag),
+                    LArule[states[i]->lookaheadsp + j]->number - 1);
+    }
+  fprintf (out, "Lookaheads: END\n");
+}
+

 void
 lalr (void)
 {
 void
 lalr (void)
 {

-  tokensetsize = WORDSIZE (ntokens);
-

   initialize_lookaheads ();
   initialize_LA ();
   set_goto_map ();
   initialize_lookaheads ();
   initialize_LA ();
   set_goto_map ();


@@ -556,4 +581,7 @@ lalr (void)
   build_relations ();
   compute_FOLLOWS ();
   compute_lookaheads ();
   build_relations ();
   compute_FOLLOWS ();
   compute_lookaheads ();

+
+  if (trace_flag)
+    lookaheads_print (stderr);

 }
 }