* src/system.h (LIST_FREE, shortcpy): New.

[bison.git] / src / lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index 4b11caaa7d124ecaeccee297da91031368ddb26f..42cd05ef938f287ae97866fccd98c1c7a02eb29d 100644 (file)
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -1,5 +1,5 @@
 /* Compute look-ahead criteria for bison,
 /* Compute look-ahead criteria for bison,

-   Copyright 1984, 1986, 1989, 2000 Free Software Foundation, Inc.
+   Copyright 1984, 1986, 1989, 2000, 2001  Free Software Foundation, Inc.

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


@@ -38,13 +38,9 @@
 state_t *state_table = NULL;
 
 int tokensetsize;
 state_t *state_table = NULL;
 
 int tokensetsize;

-short *lookaheads;

 short *LAruleno;
 unsigned *LA;
 
 short *LAruleno;
 unsigned *LA;
 

-char *consistent;
-shifts **shift_table;
-reductions **reduction_table;

 short *goto_map;
 short *from_state;
 short *to_state;
 short *goto_map;
 short *from_state;
 short *to_state;


@@ -52,9 +48,13 @@ short *to_state;
 extern void berror PARAMS ((const char *));
 
 static int infinity;
 extern void berror PARAMS ((const char *));
 
 static int infinity;

-static int maxrhs;

 static int ngotos;
 static int ngotos;

-static unsigned *F;
+
+/* And for the famous F variable, which named is so descriptive that a
+   comment is hardly needed.  <grin>.  */
+static unsigned *F = NULL;
+#define F(Rule)  (F + (Rule) * tokensetsize)
+

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


@@ -78,8 +78,8 @@ traverse (int i)
   VERTICES[++top] = i;
   INDEX[i] = height = top;
 
   VERTICES[++top] = i;
   INDEX[i] = height = top;
 

-  base = F + i * tokensetsize;
-  fp3 = base + tokensetsize;
+  base = F (i);
+  fp3 = F (i + 1);

 
   rp = R[i];
   if (rp)
 
   rp = R[i];
   if (rp)


@@ -93,7 +93,7 @@ traverse (int i)
            INDEX[i] = INDEX[j];
 
          fp1 = base;
            INDEX[i] = INDEX[j];
 
          fp1 = base;

-         fp2 = F + j * tokensetsize;
+         fp2 = F (j);

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


@@ -111,7 +111,7 @@ traverse (int i)
            break;
 
          fp1 = base;
            break;
 
          fp1 = base;

-         fp2 = F + j * tokensetsize;
+         fp2 = F (j);

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


@@ -136,56 +136,85 @@ digraph (short **relation)
     INDEX[i] = 0;
 
   for (i = 0; i < ngotos; i++)
     INDEX[i] = 0;
 
   for (i = 0; i < ngotos; i++)

-    {
-      if (INDEX[i] == 0 && R[i])
-       traverse (i);
-    }
+    if (INDEX[i] == 0 && R[i])
+      traverse (i);

 
   XFREE (INDEX);
   XFREE (VERTICES);
 }
 
 
   XFREE (INDEX);
   XFREE (VERTICES);
 }
 

-static void
-set_state_table (void)
-{
-  core *sp;
-
-  state_table = XCALLOC (state_t, nstates);
-
-  for (sp = first_state; sp; sp = sp->next)
-    {
-      state_table[sp->number].state = sp;
-      state_table[sp->number].accessing_symbol = sp->accessing_symbol;
-    }
-}
-
-
-static void
-set_shift_table (void)
-{
-  shifts *sp;
-
-  shift_table = XCALLOC (shifts *, nstates);
-
-  for (sp = first_shift; sp; sp = sp->next)
-    shift_table[sp->number] = sp;
-}

 
 

+/*--------------------.
+| Build STATE_TABLE.  |
+`--------------------*/

 
 static void
 
 static void

-set_reduction_table (void)
+set_state_table (void)

 {
 {

-  reductions *rp;
-
-  reduction_table = XCALLOC (reductions *, nstates);
-
-  for (rp = first_reduction; rp; rp = rp->next)
-    reduction_table[rp->number] = rp;
+  /* NSTATES + 1 because lookahead for the pseudo state number NSTATES
+     might be used (see conflicts.c).  It is too opaque for me to
+     provide a probably less hacky implementation. --akim */
+  state_table = XCALLOC (state_t, nstates + 1);
+
+  {
+    core *sp;
+    for (sp = first_state; sp; sp = sp->next)
+      {
+       state_table[sp->number].state = sp;
+       state_table[sp->number].accessing_symbol = sp->accessing_symbol;
+      }
+  }
+
+  {
+    shifts *sp;
+    for (sp = first_shift; sp; sp = sp->next)
+      state_table[sp->number].shift_table = sp;
+  }
+
+  {
+    reductions *rp;
+    for (rp = first_reduction; rp; rp = rp->next)
+      state_table[rp->number].reduction_table = rp;
+  }
+
+  /* Initializing the lookaheads members.  Please note that it must be
+     performed after having set some of the other members which are
+     used below.  Change with extreme caution.  */
+  {
+    int i;
+    int count = 0;
+    for (i = 0; i < nstates; i++)
+      {
+       int k;
+       reductions *rp = state_table[i].reduction_table;
+       shifts *sp = state_table[i].shift_table;
+
+       state_table[i].lookaheads = count;
+
+       if (rp
+           && (rp->nreds > 1
+               || (sp && !ISVAR (state_table[sp->shifts[0]].accessing_symbol))))
+         count += rp->nreds;
+       else
+         state_table[i].consistent = 1;
+
+       if (sp)
+         for (k = 0; k < sp->nshifts; k++)
+           if (state_table[sp->shifts[k]].accessing_symbol
+               == error_token_number)
+             {
+               state_table[i].consistent = 0;
+               break;
+             }
+      }
+     state_table[nstates].lookaheads = count;
+  }

 }
 
 
 }
 
 

-static void
-set_maxrhs (void)
+/* Return the size of the longest ride hand side of the rules. */
+static size_t
+maxrhs (void)

 {
   short *itemp;
   int length;
 {
   short *itemp;
   int length;


@@ -207,7 +236,7 @@ set_maxrhs (void)
        }
     }
 
        }
     }
 

-  maxrhs = max;
+  return max;

 }
 
 
 }
 
 


@@ -216,65 +245,23 @@ initialize_LA (void)
 {
   int i;
   int j;
 {
   int i;
   int j;

-  int count;
-  reductions *rp;
-  shifts *sp;

   short *np;
   short *np;

+  reductions *rp;

 
 

-  consistent = XCALLOC (char, nstates);
-  lookaheads = XCALLOC (short, nstates + 1);
-
-  count = 0;
-  for (i = 0; i < nstates; i++)
-    {
-      int k;
-
-      lookaheads[i] = count;
-
-      rp = reduction_table[i];
-      sp = shift_table[i];
-      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++)
-         if (state_table[sp->shifts[k]].accessing_symbol
-             == error_token_number)
-           {
-             consistent[i] = 0;
-             break;
-           }
-    }
-
-  lookaheads[nstates] = count;
+  size_t nLA = state_table[nstates].lookaheads;
+  if (!nLA)
+    nLA = 1;

 
 

-  if (count == 0)
-    {
-      LA = XCALLOC (unsigned, 1 * tokensetsize);
-      LAruleno = XCALLOC (short, 1);
-      lookback = XCALLOC (shorts *, 1);
-    }
-  else
-    {
-      LA = XCALLOC (unsigned, count * tokensetsize);
-      LAruleno = XCALLOC (short, count);
-      lookback = XCALLOC (shorts *, count);
-    }
+  LA = XCALLOC (unsigned, nLA * tokensetsize);
+  LAruleno = XCALLOC (short, nLA);
+  lookback = XCALLOC (shorts *, nLA);

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

-    {
-      if (!consistent[i])
-       {
-         if ((rp = reduction_table[i]))
-           for (j = 0; j < rp->nreds; j++)
-             *np++ = rp->rules[j];
-       }
-    }
+    if (!state_table[i].consistent)
+      if ((rp = state_table[i].reduction_table))
+       for (j = 0; j < rp->nreds; j++)
+         *np++ = rp->rules[j];

 }
 
 
 }
 
 


@@ -408,7 +395,7 @@ initialize_F (void)
   for (i = 0; i < ngotos; i++)
     {
       stateno = to_state[i];
   for (i = 0; i < ngotos; i++)
     {
       stateno = to_state[i];

-      sp = shift_table[stateno];
+      sp = state_table[stateno].shift_table;

 
       if (sp)
        {
 
       if (sp)
        {


@@ -447,10 +434,7 @@ initialize_F (void)
   digraph (reads);
 
   for (i = 0; i < ngotos; i++)
   digraph (reads);
 
   for (i = 0; i < ngotos; i++)

-    {
-      if (reads[i])
-       XFREE (reads[i]);
-    }
+    XFREE (reads[i]);

 
   XFREE (reads);
   XFREE (edge);
 
   XFREE (reads);
   XFREE (edge);


@@ -465,8 +449,8 @@ add_lookback_edge (int stateno, int ruleno, int gotono)
   int found;
   shorts *sp;
 
   int found;
   shorts *sp;
 

-  i = lookaheads[stateno];
-  k = lookaheads[stateno + 1];
+  i = state_table[stateno].lookaheads;
+  k = state_table[stateno + 1].lookaheads;

   found = 0;
   while (!found && i < k)
     {
   found = 0;
   while (!found && i < k)
     {


@@ -563,7 +547,7 @@ build_relations (void)
 
   includes = XCALLOC (short *, ngotos);
   edge = XCALLOC (short, ngotos + 1);
 
   includes = XCALLOC (short *, ngotos);
   edge = XCALLOC (short, ngotos + 1);

-  states = XCALLOC (short, maxrhs + 1);
+  states = XCALLOC (short, maxrhs () + 1);

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


@@ -577,10 +561,10 @@ build_relations (void)
          states[0] = state1;
          stateno = state1;
 
          states[0] = state1;
          stateno = state1;
 

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

            {
              symbol2 = *rp;
            {
              symbol2 = *rp;

-             sp = shift_table[stateno];
+             sp = state_table[stateno].shift_table;

              k = sp->nshifts;
 
              for (j = 0; j < k; j++)
              k = sp->nshifts;
 
              for (j = 0; j < k; j++)


@@ -593,7 +577,7 @@ build_relations (void)
              states[length++] = stateno;
            }
 
              states[length++] = stateno;
            }
 

-         if (!consistent[stateno])
+         if (!state_table[stateno].consistent)

            add_lookback_edge (stateno, *rulep, i);
 
          length--;
            add_lookback_edge (stateno, *rulep, i);
 
          length--;


@@ -646,10 +630,7 @@ compute_FOLLOWS (void)
   digraph (includes);
 
   for (i = 0; i < ngotos; i++)
   digraph (includes);
 
   for (i = 0; i < ngotos; i++)

-    {
-      if (includes[i])
-       XFREE (includes[i]);
-    }
+    XFREE (includes[i]);

 
   XFREE (includes);
 }
 
   XFREE (includes);
 }


@@ -659,39 +640,20 @@ static void
 compute_lookaheads (void)
 {
   int i;
 compute_lookaheads (void)
 {
   int i;

-  int n;
-  unsigned *fp1;
-  unsigned *fp2;
-  unsigned *fp3;

   shorts *sp;
   shorts *sp;

-  unsigned *rowp;
-  shorts *sptmp;               /* JF */

 
 

-  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++;
-       }
-
-      rowp = fp3;
-    }
+  for (i = 0; i < state_table[nstates].lookaheads; i++)
+    for (sp = lookback[i]; sp; sp = sp->next)
+      {
+       unsigned *fp1 = LA (i);
+       unsigned *fp2 = F (sp->value);
+       while (fp1 < LA (i + 1))
+         *fp1++ |= *fp2++;
+      }

 
 

-  for (i = 0; i < n; i++)
-    {
-      /* JF removed ref to freed storage */
-      for (sp = lookback[i]; sp; sp = sptmp)
-       {
-         sptmp = sp->next;
-         XFREE (sp);
-       }
-    }
+  /* Free LOOKBACK. */
+  for (i = 0; i < state_table[nstates].lookaheads; i++)
+    LIST_FREE (shorts, lookback[i]);

 
   XFREE (lookback);
   XFREE (F);
 
   XFREE (lookback);
   XFREE (F);


@@ -704,9 +666,6 @@ lalr (void)
   tokensetsize = WORDSIZE (ntokens);
 
   set_state_table ();
   tokensetsize = WORDSIZE (ntokens);
 
   set_state_table ();

-  set_shift_table ();
-  set_reduction_table ();
-  set_maxrhs ();

   initialize_LA ();
   set_goto_map ();
   initialize_F ();
   initialize_LA ();
   set_goto_map ();
   initialize_F ();