* src/lalr.h (state_t): New.

[bison.git] / src / lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index 117f2b9fa9d15a756ea4645b35c8cf64e572c54f..4b11caaa7d124ecaeccee297da91031368ddb26f 100644 (file)
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -1,99 +1,55 @@
 /* Compute look-ahead criteria for bison,
 /* Compute look-ahead criteria for bison,

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

 
 

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

 
 

-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.
+   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.

 
 

-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.  */
+   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.  */

 
 
 
 

-/* 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.  */

 
 

-lalr(), the entry point, builds these data structures:
-
-goto_map, from_state and to_state 
- record each shift transition which accepts a variable (a nonterminal).
-ngotos is the number of such transitions.
-from_state[t] is the state number which a transition leads from
-and to_state[t] is the state number it leads to.
-All the transitions that accept a particular variable are grouped together and
-goto_map[i - ntokens] is the index in from_state and to_state of the first of them.
-
-consistent[s] is nonzero if no lookahead is needed to decide what to do in state s.
-
-LAruleno is a vector which records the rules that need lookahead in various states.
-The elements of LAruleno that apply to state s are those from
- lookaheads[s] through lookaheads[s+1]-1.
-Each element of LAruleno is a rule number.
-
-If lr is the length of LAruleno, then a number from 0 to lr-1 
-can specify both a rule and a state where the rule might be applied.
-
-LA is a lr by ntokens matrix of bits.
-LA[l, i] is 1 if the rule LAruleno[l] is applicable in the appropriate state
- when the next token is symbol i.
-If LA[l, i] and LA[l, j] are both 1 for i != j, it is a conflict.
-*/
-
-#include <stdio.h>

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

-#include "machine.h"

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

-#include "state.h"
-#include "alloc.h"
+#include "LR0.h"

 #include "gram.h"
 #include "gram.h"

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

 
 

-
-extern short **derives;
-extern char *nullable;
-
+/* All the decorated states, indexed by the state number.  Warning:
+   there is a state_TABLE in LR0.c, but it is different and static.
+   */
+state_t *state_table = NULL;

 
 int tokensetsize;
 short *lookaheads;
 short *LAruleno;
 unsigned *LA;
 
 int tokensetsize;
 short *lookaheads;
 short *LAruleno;
 unsigned *LA;

-short *accessing_symbol;
+

 char *consistent;
 char *consistent;

-core **state_table;

 shifts **shift_table;
 reductions **reduction_table;
 short *goto_map;
 short *from_state;
 short *to_state;
 
 shifts **shift_table;
 reductions **reduction_table;
 short *goto_map;
 short *from_state;
 short *to_state;
 

-void lalr PARAMS((void));
-short **transpose PARAMS((short **, int));
-void set_state_table PARAMS((void));
-void set_accessing_symbol PARAMS((void));
-void set_shift_table PARAMS((void));
-void set_reduction_table PARAMS((void));
-void set_maxrhs PARAMS((void));
-void initialize_LA PARAMS((void));
-void set_goto_map PARAMS((void));
-int map_goto PARAMS((int, int));
-void initialize_F PARAMS((void));
-void build_relations PARAMS((void));
-void add_lookback_edge PARAMS((int, int, int));
-void compute_FOLLOWS PARAMS((void));
-void compute_lookaheads PARAMS((void));
-void digraph PARAMS((short **));
-void traverse PARAMS((register int));
-
-extern void toomany PARAMS((char *));
-extern void berror PARAMS((char *));
+extern void berror PARAMS ((const char *));

 
 static int infinity;
 static int maxrhs;
 
 static int infinity;
 static int maxrhs;


@@ -107,79 +63,133 @@ static short *VERTICES;
 static int top;
 
 
 static int top;
 
 

-void
-lalr (void)
+static void
+traverse (int i)

 {
 {

-  tokensetsize = WORDSIZE(ntokens);
-
-  set_state_table();
-  set_accessing_symbol();
-  set_shift_table();
-  set_reduction_table();
-  set_maxrhs();
-  initialize_LA();
-  set_goto_map();
-  initialize_F();
-  build_relations();
-  compute_FOLLOWS();
-  compute_lookaheads();
+  unsigned *fp1;
+  unsigned *fp2;
+  unsigned *fp3;
+  int j;
+  short *rp;
+
+  int height;
+  unsigned *base;
+
+  VERTICES[++top] = i;
+  INDEX[i] = height = top;
+
+  base = F + i * tokensetsize;
+  fp3 = base + tokensetsize;
+
+  rp = R[i];
+  if (rp)
+    {
+      while ((j = *rp++) >= 0)
+       {
+         if (INDEX[j] == 0)
+           traverse (j);
+
+         if (INDEX[i] > INDEX[j])
+           INDEX[i] = INDEX[j];
+
+         fp1 = base;
+         fp2 = F + j * tokensetsize;
+
+         while (fp1 < fp3)
+           *fp1++ |= *fp2++;
+       }
+    }
+
+  if (INDEX[i] == height)
+    {
+      for (;;)
+       {
+         j = VERTICES[top--];
+         INDEX[j] = infinity;
+
+         if (i == j)
+           break;
+
+         fp1 = base;
+         fp2 = F + j * tokensetsize;
+
+         while (fp1 < fp3)
+           *fp2++ = *fp1++;
+       }
+    }

 }
 
 
 }
 
 

-void
-set_state_table (void)
+static void
+digraph (short **relation)

 {
 {

-  register core *sp;
+  int i;

 
 

-  state_table = NEW2(nstates, core *);
+  infinity = ngotos + 2;
+  INDEX = XCALLOC (short, ngotos + 1);
+  VERTICES = XCALLOC (short, ngotos + 1);
+  top = 0;

 
 

-  for (sp = first_state; sp; sp = sp->next)
-    state_table[sp->number] = sp;
-}
+  R = relation;

 
 

+  for (i = 0; i < ngotos; i++)
+    INDEX[i] = 0;

 
 

-void
-set_accessing_symbol (void)
+  for (i = 0; i < ngotos; i++)
+    {
+      if (INDEX[i] == 0 && R[i])
+       traverse (i);
+    }
+
+  XFREE (INDEX);
+  XFREE (VERTICES);
+}
+
+static void
+set_state_table (void)

 {
 {

-  register core *sp;
+  core *sp;

 
 

-  accessing_symbol = NEW2(nstates, short);
+  state_table = XCALLOC (state_t, nstates);

 
   for (sp = first_state; sp; sp = sp->next)
 
   for (sp = first_state; sp; sp = sp->next)

-    accessing_symbol[sp->number] = sp->accessing_symbol;
+    {
+      state_table[sp->number].state = sp;
+      state_table[sp->number].accessing_symbol = sp->accessing_symbol;
+    }

 }
 
 
 }
 
 

-void
+static void

 set_shift_table (void)
 {
 set_shift_table (void)
 {

-  register shifts *sp;
+  shifts *sp;

 
 

-  shift_table = NEW2(nstates, shifts *);
+  shift_table = XCALLOC (shifts *, nstates);

 
   for (sp = first_shift; sp; sp = sp->next)
     shift_table[sp->number] = sp;
 }
 
 
 
   for (sp = first_shift; sp; sp = sp->next)
     shift_table[sp->number] = sp;
 }
 
 

-void
+static void

 set_reduction_table (void)
 {
 set_reduction_table (void)
 {

-  register reductions *rp;
+  reductions *rp;

 
 

-  reduction_table = NEW2(nstates, reductions *);
+  reduction_table = XCALLOC (reductions *, nstates);

 
   for (rp = first_reduction; rp; rp = rp->next)
     reduction_table[rp->number] = rp;
 }
 
 
 
   for (rp = first_reduction; rp; rp = rp->next)
     reduction_table[rp->number] = rp;
 }
 
 

-void
+static void

 set_maxrhs (void)
 {
 set_maxrhs (void)
 {

-  register short *itemp;
-  register int length;
-  register int max;
+  short *itemp;
+  int length;
+  int max;

 
   length = 0;
   max = 0;
 
   length = 0;
   max = 0;


@@ -191,7 +201,8 @@ set_maxrhs (void)
        }
       else
        {
        }
       else
        {

-         if (length > max) max = length;
+         if (length > max)
+           max = length;

          length = 0;
        }
     }
          length = 0;
        }
     }


@@ -200,58 +211,58 @@ set_maxrhs (void)
 }
 
 
 }
 
 

-void
+static void

 initialize_LA (void)
 {
 initialize_LA (void)
 {

-  register int i;
-  register int j;
-  register int count;
-  register reductions *rp;
-  register shifts *sp;
-  register short *np;
+  int i;
+  int j;
+  int count;
+  reductions *rp;
+  shifts *sp;
+  short *np;

 
 

-  consistent = NEW2(nstates, char);
-  lookaheads = NEW2(nstates + 1, short);
+  consistent = XCALLOC (char, nstates);
+  lookaheads = XCALLOC (short, nstates + 1);

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

-      register int k;
+      int k;

 
       lookaheads[i] = count;
 
       rp = reduction_table[i];
       sp = shift_table[i];
 
       lookaheads[i] = count;
 
       rp = reduction_table[i];
       sp = shift_table[i];

-      if (rp && (rp->nreds > 1
-          || (sp && ! ISVAR(accessing_symbol[sp->shifts[0]]))))
+      if (rp
+         && (rp->nreds > 1
+             || (sp && !ISVAR (state_table[sp->shifts[0]].accessing_symbol))))

        count += rp->nreds;
       else
        consistent[i] = 1;
 
       if (sp)
        for (k = 0; k < sp->nshifts; k++)
        count += rp->nreds;
       else
        consistent[i] = 1;
 
       if (sp)
        for (k = 0; k < sp->nshifts; k++)

-         {
-           if (accessing_symbol[sp->shifts[k]] == error_token_number)
-             {
-               consistent[i] = 0;
-               break;
-             }
-         }
+         if (state_table[sp->shifts[k]].accessing_symbol
+             == error_token_number)
+           {
+             consistent[i] = 0;
+             break;
+           }

     }
 
   lookaheads[nstates] = count;
 
   if (count == 0)
     {
     }
 
   lookaheads[nstates] = count;
 
   if (count == 0)
     {

-      LA = NEW2(1 * tokensetsize, unsigned);
-      LAruleno = NEW2(1, short);
-      lookback = NEW2(1, shorts *);
+      LA = XCALLOC (unsigned, 1 * tokensetsize);
+      LAruleno = XCALLOC (short, 1);
+      lookback = XCALLOC (shorts *, 1);

     }
   else
     {
     }
   else
     {

-      LA = NEW2(count * tokensetsize, unsigned);
-      LAruleno = NEW2(count, short);
-      lookback = NEW2(count, shorts *);
+      LA = XCALLOC (unsigned, count * tokensetsize);
+      LAruleno = XCALLOC (short, count);
+      lookback = XCALLOC (shorts *, count);

     }
 
   np = LAruleno;
     }
 
   np = LAruleno;


@@ -267,35 +278,36 @@ initialize_LA (void)
 }
 
 
 }
 
 

-void
+static void

 set_goto_map (void)
 {
 set_goto_map (void)
 {

-  register shifts *sp;
-  register int i;
-  register int symbol;
-  register int k;
-  register short *temp_map;
-  register int state2;
-  register int state1;
+  shifts *sp;
+  int i;
+  int symbol;
+  int k;
+  short *temp_map;
+  int state2;
+  int state1;

 
 

-  goto_map = NEW2(nvars + 1, short) - ntokens;
-  temp_map = NEW2(nvars + 1, short) - ntokens;
+  goto_map = XCALLOC (short, nvars + 1) - ntokens;
+  temp_map = XCALLOC (short, nvars + 1) - ntokens;

 
   ngotos = 0;
   for (sp = first_shift; sp; sp = sp->next)
     {
       for (i = sp->nshifts - 1; i >= 0; i--)
        {
 
   ngotos = 0;
   for (sp = first_shift; sp; sp = sp->next)
     {
       for (i = sp->nshifts - 1; i >= 0; i--)
        {

-         symbol = accessing_symbol[sp->shifts[i]];
+         symbol = state_table[sp->shifts[i]].accessing_symbol;

 
 

-         if (ISTOKEN(symbol)) break;
+         if (ISTOKEN (symbol))
+           break;

 
          if (ngotos == MAXSHORT)
 
          if (ngotos == MAXSHORT)

-           toomany(_("gotos"));
+           fatal (_("too many gotos (max %d)"), MAXSHORT);

 
          ngotos++;
          goto_map[symbol]++;
 
          ngotos++;
          goto_map[symbol]++;

-        }
+       }

     }
 
   k = 0;
     }
 
   k = 0;


@@ -311,8 +323,8 @@ set_goto_map (void)
   goto_map[nsyms] = ngotos;
   temp_map[nsyms] = ngotos;
 
   goto_map[nsyms] = ngotos;
   temp_map[nsyms] = ngotos;
 

-  from_state = NEW2(ngotos, short);
-  to_state = NEW2(ngotos, short);
+  from_state = XCALLOC (short, ngotos);
+  to_state = XCALLOC (short, ngotos);

 
   for (sp = first_shift; sp; sp = sp->next)
     {
 
   for (sp = first_shift; sp; sp = sp->next)
     {


@@ -320,9 +332,10 @@ set_goto_map (void)
       for (i = sp->nshifts - 1; i >= 0; i--)
        {
          state2 = sp->shifts[i];
       for (i = sp->nshifts - 1; i >= 0; i--)
        {
          state2 = sp->shifts[i];

-         symbol = accessing_symbol[state2];
+         symbol = state_table[state2].accessing_symbol;

 
 

-         if (ISTOKEN(symbol)) break;
+         if (ISTOKEN (symbol))
+           break;

 
          k = temp_map[symbol]++;
          from_state[k] = state1;
 
          k = temp_map[symbol]++;
          from_state[k] = state1;


@@ -330,20 +343,22 @@ set_goto_map (void)
        }
     }
 
        }
     }
 

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

 }
 
 
 
 }
 
 
 

-/*  Map_goto maps a state/symbol pair into its numeric representation. */
+/*----------------------------------------------------------.
+| Map a state/symbol pair into its numeric representation.  |
+`----------------------------------------------------------*/

 
 

-int
+static int

 map_goto (int state, int symbol)
 {
 map_goto (int state, int symbol)
 {

-  register int high;
-  register int low;
-  register int middle;
-  register int s;
+  int high;
+  int low;
+  int middle;
+  int s;

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


@@ -353,40 +368,40 @@ map_goto (int state, int symbol)
       middle = (low + high) / 2;
       s = from_state[middle];
       if (s == state)
       middle = (low + high) / 2;
       s = from_state[middle];
       if (s == state)

-       return (middle);
+       return middle;

       else if (s < state)
        low = middle + 1;
       else
        high = middle - 1;
     }
 
       else if (s < state)
        low = middle + 1;
       else
        high = middle - 1;
     }
 

-  berror("map_goto");
-/* NOTREACHED */
+  assert (0);
+  /* NOTREACHED */

   return 0;
 }
 
 
   return 0;
 }
 
 

-void
+static void

 initialize_F (void)
 {
 initialize_F (void)
 {

-  register int i;
-  register int j;
-  register int k;
-  register shifts *sp;
-  register short *edge;
-  register unsigned *rowp;
-  register short *rp;
-  register short **reads;
-  register int nedges;
-  register int stateno;
-  register int symbol;
-  register int nwords;
+  int i;
+  int j;
+  int k;
+  shifts *sp;
+  short *edge;
+  unsigned *rowp;
+  short *rp;
+  short **reads;
+  int nedges;
+  int stateno;
+  int symbol;
+  int nwords;

 
   nwords = ngotos * tokensetsize;
 
   nwords = ngotos * tokensetsize;

-  F = NEW2(nwords, unsigned);
+  F = XCALLOC (unsigned, nwords);

 
 

-  reads = NEW2(ngotos, short *);
-  edge = NEW2(ngotos + 1, short);
+  reads = XCALLOC (short *, ngotos);
+  edge = XCALLOC (short, ngotos + 1);

   nedges = 0;
 
   rowp = F;
   nedges = 0;
 
   rowp = F;


@@ -401,22 +416,22 @@ initialize_F (void)
 
          for (j = 0; j < k; j++)
            {
 
          for (j = 0; j < k; j++)
            {

-             symbol = accessing_symbol[sp->shifts[j]];
-             if (ISVAR(symbol))
+             symbol = state_table[sp->shifts[j]].accessing_symbol;
+             if (ISVAR (symbol))

                break;
                break;

-             SETBIT(rowp, symbol);
+             SETBIT (rowp, symbol);

            }
 
          for (; j < k; j++)
            {
            }
 
          for (; j < k; j++)
            {

-             symbol = accessing_symbol[sp->shifts[j]];
+             symbol = state_table[sp->shifts[j]].accessing_symbol;

              if (nullable[symbol])
              if (nullable[symbol])

-               edge[nedges++] = map_goto(stateno, symbol);
+               edge[nedges++] = map_goto (stateno, symbol);

            }
            }

-       
+

          if (nedges)
            {
          if (nedges)
            {

-             reads[i] = rp = NEW2(nedges + 1, short);
+             reads[i] = rp = XCALLOC (short, nedges + 1);

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


@@ -429,121 +444,26 @@ initialize_F (void)
       rowp += tokensetsize;
     }
 
       rowp += tokensetsize;
     }
 

-  digraph(reads);
+  digraph (reads);

 
   for (i = 0; i < ngotos; i++)
     {
       if (reads[i])
 
   for (i = 0; i < ngotos; i++)
     {
       if (reads[i])

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

     }
 
     }
 

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

 }
 
 
 }
 
 

-void
-build_relations (void)
-{
-  register int i;
-  register int j;
-  register int k;
-  register short *rulep;
-  register short *rp;
-  register shifts *sp;
-  register int length;
-  register int nedges;
-  register int done;
-  register int state1;
-  register int stateno;
-  register int symbol1;
-  register int symbol2;
-  register short *shortp;
-  register short *edge;
-  register short *states;
-  register short **new_includes;
-
-  includes = NEW2(ngotos, short *);
-  edge = NEW2(ngotos + 1, short);
-  states = NEW2(maxrhs + 1, short);
-
-  for (i = 0; i < ngotos; i++)
-    {
-      nedges = 0;
-      state1 = from_state[i];
-      symbol1 = accessing_symbol[to_state[i]];
-
-      for (rulep = derives[symbol1]; *rulep > 0; rulep++)
-       {
-         length = 1;
-         states[0] = state1;
-         stateno = state1;
-
-         for (rp = ritem + rrhs[*rulep]; *rp > 0; rp++)
-           {
-             symbol2 = *rp;
-             sp = shift_table[stateno];
-             k = sp->nshifts;
-
-             for (j = 0; j < k; j++)
-               {
-                 stateno = sp->shifts[j];
-                 if (accessing_symbol[stateno] == symbol2) break;
-               }
-
-             states[length++] = stateno;
-           }
-
-         if (!consistent[stateno])
-           add_lookback_edge(stateno, *rulep, i);
-
-         length--;
-         done = 0;
-         while (!done)
-           {
-             done = 1;
-             rp--;
-                       /* JF added rp>=ritem &&   I hope to god its right! */
-             if (rp>=ritem && ISVAR(*rp))
-               {
-                 stateno = states[--length];
-                 edge[nedges++] = map_goto(stateno, *rp);
-                 if (nullable[*rp]) done = 0;
-               }
-           }
-       }
-
-      if (nedges)
-       {
-         includes[i] = shortp = NEW2(nedges + 1, short);
-         for (j = 0; j < nedges; j++)
-           shortp[j] = edge[j];
-         shortp[nedges] = -1;
-       }
-    }
-
-  new_includes = transpose(includes, ngotos);
-
-  for (i = 0; i < ngotos; i++)
-    if (includes[i])
-      FREE(includes[i]);
-
-  FREE(includes);
-
-  includes = new_includes;
-
-  FREE(edge);
-  FREE(states);
-}
-
-
-void
+static void

 add_lookback_edge (int stateno, int ruleno, int gotono)
 {
 add_lookback_edge (int stateno, int ruleno, int gotono)
 {

-  register int i;
-  register int k;
-  register int found;
-  register shorts *sp;
+  int i;
+  int k;
+  int found;
+  shorts *sp;

 
   i = lookaheads[stateno];
   k = lookaheads[stateno + 1];
 
   i = lookaheads[stateno];
   k = lookaheads[stateno + 1];


@@ -556,28 +476,26 @@ add_lookback_edge (int stateno, int ruleno, int gotono)
        i++;
     }
 
        i++;
     }
 

-  if (found == 0)
-    berror("add_lookback_edge");
+  assert (found);

 
 

-  sp = NEW(shorts);
+  sp = XCALLOC (shorts, 1);

   sp->next = lookback[i];
   sp->value = gotono;
   lookback[i] = sp;
 }
 
 
   sp->next = lookback[i];
   sp->value = gotono;
   lookback[i] = sp;
 }
 
 

-
-short **
+static short **

 transpose (short **R_arg, int n)
 {
 transpose (short **R_arg, int n)
 {

-  register short **new_R;
-  register short **temp_R;
-  register short *nedges;
-  register short *sp;
-  register int i;
-  register int k;
+  short **new_R;
+  short **temp_R;
+  short *nedges;
+  short *sp;
+  int i;
+  int k;

 
 

-  nedges = NEW2(n, short);
+  nedges = XCALLOC (short, n);

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


@@ -589,22 +507,22 @@ transpose (short **R_arg, int n)
        }
     }
 
        }
     }
 

-  new_R = NEW2(n, short *);
-  temp_R = NEW2(n, short *);
+  new_R = XCALLOC (short *, n);
+  temp_R = XCALLOC (short *, n);

 
   for (i = 0; i < n; i++)
     {
       k = nedges[i];
       if (k > 0)
        {
 
   for (i = 0; i < n; i++)
     {
       k = nedges[i];
       if (k > 0)
        {

-         sp = NEW2(k + 1, short);
+         sp = XCALLOC (short, k + 1);

          new_R[i] = sp;
          temp_R[i] = sp;
          sp[k] = -1;
        }
     }
 
          new_R[i] = sp;
          temp_R[i] = sp;
          sp[k] = -1;
        }
     }
 

-  FREE(nedges);
+  XFREE (nedges);

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


@@ -616,149 +534,183 @@ transpose (short **R_arg, int n)
        }
     }
 
        }
     }
 

-  FREE(temp_R);
+  XFREE (temp_R);

 
 

-  return (new_R);
+  return new_R;

 }
 
 
 }
 
 

-void
-compute_FOLLOWS (void)
+static void
+build_relations (void)

 {
 {

-  register int i;
-
-  digraph(includes);
+  int i;
+  int j;
+  int k;
+  short *rulep;
+  short *rp;
+  shifts *sp;
+  int length;
+  int nedges;
+  int done;
+  int state1;
+  int stateno;
+  int symbol1;
+  int symbol2;
+  short *shortp;
+  short *edge;
+  short *states;
+  short **new_includes;
+
+  includes = XCALLOC (short *, ngotos);
+  edge = XCALLOC (short, ngotos + 1);
+  states = XCALLOC (short, maxrhs + 1);

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

-      if (includes[i]) FREE(includes[i]);
-    }
+      nedges = 0;
+      state1 = from_state[i];
+      symbol1 = state_table[to_state[i]].accessing_symbol;

 
 

-  FREE(includes);
-}
+      for (rulep = derives[symbol1]; *rulep > 0; rulep++)
+       {
+         length = 1;
+         states[0] = state1;
+         stateno = state1;

 
 

+         for (rp = ritem + rrhs[*rulep]; *rp > 0; rp++)
+           {
+             symbol2 = *rp;
+             sp = shift_table[stateno];
+             k = sp->nshifts;

 
 

-void
-compute_lookaheads (void)
-{
-  register int i;
-  register int n;
-  register unsigned *fp1;
-  register unsigned *fp2;
-  register unsigned *fp3;
-  register shorts *sp;
-  register unsigned *rowp;
-/*   register short *rulep; JF unused */
-/*  register int count; JF unused */
-  register shorts *sptmp;/* JF */
+             for (j = 0; j < k; j++)
+               {
+                 stateno = sp->shifts[j];
+                 if (state_table[stateno].accessing_symbol == symbol2)
+                   break;
+               }

 
 

-  rowp = LA;
-  n = lookaheads[nstates];
-  for (i = 0; i < n; i++)
-    {
-      fp3 = rowp + tokensetsize;
-      for (sp = lookback[i]; sp; sp = sp->next)
-       {
-         fp1 = rowp;
-         fp2 = F + tokensetsize * sp->value;
-         while (fp1 < fp3)
-           *fp1++ |= *fp2++;
+             states[length++] = stateno;
+           }
+
+         if (!consistent[stateno])
+           add_lookback_edge (stateno, *rulep, i);
+
+         length--;
+         done = 0;
+         while (!done)
+           {
+             done = 1;
+             rp--;
+             /* JF added rp>=ritem &&   I hope to god its right! */
+             if (rp >= ritem && ISVAR (*rp))
+               {
+                 stateno = states[--length];
+                 edge[nedges++] = map_goto (stateno, *rp);
+                 if (nullable[*rp])
+                   done = 0;
+               }
+           }

        }
 
        }
 

-      rowp = fp3;
+      if (nedges)
+       {
+         includes[i] = shortp = XCALLOC (short, nedges + 1);
+         for (j = 0; j < nedges; j++)
+           shortp[j] = edge[j];
+         shortp[nedges] = -1;
+       }

     }
 
     }
 

-  for (i = 0; i < n; i++)
-    {/* JF removed ref to freed storage */
-      for (sp = lookback[i]; sp; sp = sptmp) {
-       sptmp=sp->next;
-       FREE(sp);
-      }
-    }
+  new_includes = transpose (includes, ngotos);

 
 

-  FREE(lookback);
-  FREE(F);
-}
+  for (i = 0; i < ngotos; i++)
+    if (includes[i])
+      XFREE (includes[i]);

 
 

+  XFREE (includes);

 
 

-void
-digraph (short **relation)
-{
-  register int i;
+  includes = new_includes;

 
 

-  infinity = ngotos + 2;
-  INDEX = NEW2(ngotos + 1, short);
-  VERTICES = NEW2(ngotos + 1, short);
-  top = 0;
+  XFREE (edge);
+  XFREE (states);
+}

 
 

-  R = relation;

 
 

-  for (i = 0; i < ngotos; i++)
-    INDEX[i] = 0;
+
+static void
+compute_FOLLOWS (void)
+{
+  int i;
+
+  digraph (includes);

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

-      if (INDEX[i] == 0 && R[i])
-       traverse(i);
+      if (includes[i])
+       XFREE (includes[i]);

     }
 
     }
 

-  FREE(INDEX);
-  FREE(VERTICES);
+  XFREE (includes);

 }
 
 
 }
 
 

-void
-traverse (register int i)
+static void
+compute_lookaheads (void)

 {
 {

-  register unsigned *fp1;
-  register unsigned *fp2;
-  register unsigned *fp3;
-  register int j;
-  register short *rp;
+  int i;
+  int n;
+  unsigned *fp1;
+  unsigned *fp2;
+  unsigned *fp3;
+  shorts *sp;
+  unsigned *rowp;
+  shorts *sptmp;               /* JF */

 
 

-  int height;
-  unsigned *base;
-
-  VERTICES[++top] = i;
-  INDEX[i] = height = top;
-
-  base = F + i * tokensetsize;
-  fp3 = base + tokensetsize;
-
-  rp = R[i];
-  if (rp)
+  rowp = LA;
+  n = lookaheads[nstates];
+  for (i = 0; i < n; i++)

     {
     {

-      while ((j = *rp++) >= 0)
+      fp3 = rowp + tokensetsize;
+      for (sp = lookback[i]; sp; sp = sp->next)

        {
        {

-         if (INDEX[j] == 0)
-           traverse(j);
-
-         if (INDEX[i] > INDEX[j])
-           INDEX[i] = INDEX[j];
-
-         fp1 = base;
-         fp2 = F + j * tokensetsize;
-
+         fp1 = rowp;
+         fp2 = F + tokensetsize * sp->value;

          while (fp1 < fp3)
            *fp1++ |= *fp2++;
        }
          while (fp1 < fp3)
            *fp1++ |= *fp2++;
        }

+
+      rowp = fp3;

     }
 
     }
 

-  if (INDEX[i] == height)
+  for (i = 0; i < n; i++)

     {
     {

-      for (;;)
+      /* JF removed ref to freed storage */
+      for (sp = lookback[i]; sp; sp = sptmp)

        {
        {

-         j = VERTICES[top--];
-         INDEX[j] = infinity;
+         sptmp = sp->next;
+         XFREE (sp);
+       }
+    }

 
 

-         if (i == j)
-           break;
+  XFREE (lookback);
+  XFREE (F);
+}

 
 

-         fp1 = base;
-         fp2 = F + j * tokensetsize;

 
 

-         while (fp1 < fp3)
-           *fp2++ = *fp1++;
-       }
-    }
+void
+lalr (void)
+{
+  tokensetsize = WORDSIZE (ntokens);
+
+  set_state_table ();
+  set_shift_table ();
+  set_reduction_table ();
+  set_maxrhs ();
+  initialize_LA ();
+  set_goto_map ();
+  initialize_F ();
+  build_relations ();
+  compute_FOLLOWS ();
+  compute_lookaheads ();

 }
 }