X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/340ef489223a5d1f9c40674ea2973435cb8ecc1b..84b113cd22554d6660b94033199d148138b3ad33:/src/lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index af2ea100..42cd05ef 100644
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -1,5 +1,5 @@
 /* Compute look-ahead criteria for bison,
-   Copyright (C) 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.
 
@@ -26,22 +26,21 @@
 #include "system.h"
 #include "types.h"
 #include "LR0.h"
-#include "alloc.h"
 #include "gram.h"
 #include "complain.h"
 #include "lalr.h"
 #include "nullable.h"
 #include "derives.h"
 
+/* 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;
-short *accessing_symbol;
-char *consistent;
-core **state_table;
-shifts **shift_table;
-reductions **reduction_table;
+
 short *goto_map;
 short *from_state;
 short *to_state;
@@ -49,9 +48,13 @@ short *to_state;
 extern void berror PARAMS ((const char *));
 
 static int infinity;
-static int maxrhs;
 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;
@@ -75,8 +78,8 @@ traverse (int i)
   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)
@@ -90,7 +93,7 @@ traverse (int i)
 	    INDEX[i] = INDEX[j];
 
 	  fp1 = base;
-	  fp2 = F + j * tokensetsize;
+	  fp2 = F (j);
 
 	  while (fp1 < fp3)
 	    *fp1++ |= *fp2++;
@@ -108,7 +111,7 @@ traverse (int i)
 	    break;
 
 	  fp1 = base;
-	  fp2 = F + j * tokensetsize;
+	  fp2 = F (j);
 
 	  while (fp1 < fp3)
 	    *fp2++ = *fp1++;
@@ -123,8 +126,8 @@ digraph (short **relation)
   int i;
 
   infinity = ngotos + 2;
-  INDEX = NEW2 (ngotos + 1, short);
-  VERTICES = NEW2 (ngotos + 1, short);
+  INDEX = XCALLOC (short, ngotos + 1);
+  VERTICES = XCALLOC (short, ngotos + 1);
   top = 0;
 
   R = relation;
@@ -133,65 +136,85 @@ digraph (short **relation)
     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);
 
-  FREE (INDEX);
-  FREE (VERTICES);
+  XFREE (INDEX);
+  XFREE (VERTICES);
 }
 
-static void
-set_state_table (void)
-{
-  core *sp;
-
-  state_table = NEW2 (nstates, core *);
-
-  for (sp = first_state; sp; sp = sp->next)
-    state_table[sp->number] = sp;
-}
-
-
-static void
-set_accessing_symbol (void)
-{
-  core *sp;
-
-  accessing_symbol = NEW2 (nstates, short);
-
-  for (sp = first_state; sp; sp = sp->next)
-    accessing_symbol[sp->number] = sp->accessing_symbol;
-}
-
-
-static void
-set_shift_table (void)
-{
-  shifts *sp;
-
-  shift_table = NEW2 (nstates, shifts *);
-
-  for (sp = first_shift; sp; sp = sp->next)
-    shift_table[sp->number] = sp;
-}
 
+/*--------------------.
+| Build STATE_TABLE.  |
+`--------------------*/
 
 static void
-set_reduction_table (void)
+set_state_table (void)
 {
-  reductions *rp;
-
-  reduction_table = NEW2 (nstates, reductions *);
-
-  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;
@@ -213,7 +236,7 @@ set_maxrhs (void)
 	}
     }
 
-  maxrhs = max;
+  return max;
 }
 
 
@@ -222,65 +245,23 @@ initialize_LA (void)
 {
   int i;
   int j;
-  int count;
-  reductions *rp;
-  shifts *sp;
   short *np;
+  reductions *rp;
 
-  consistent = NEW2 (nstates, char);
-  lookaheads = NEW2 (nstates + 1, short);
-
-  count = 0;
-  for (i = 0; i < nstates; i++)
-    {
-      int k;
-
-      lookaheads[i] = count;
+  size_t nLA = state_table[nstates].lookaheads;
+  if (!nLA)
+    nLA = 1;
 
-      rp = reduction_table[i];
-      sp = shift_table[i];
-      if (rp && (rp->nreds > 1
-		 || (sp && !ISVAR (accessing_symbol[sp->shifts[0]]))))
-	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;
-	      }
-	  }
-    }
-
-  lookaheads[nstates] = count;
-
-  if (count == 0)
-    {
-      LA = NEW2 (1 * tokensetsize, unsigned);
-      LAruleno = NEW2 (1, short);
-      lookback = NEW2 (1, shorts *);
-    }
-  else
-    {
-      LA = NEW2 (count * tokensetsize, unsigned);
-      LAruleno = NEW2 (count, short);
-      lookback = NEW2 (count, shorts *);
-    }
+  LA = XCALLOC (unsigned, nLA * tokensetsize);
+  LAruleno = XCALLOC (short, nLA);
+  lookback = XCALLOC (shorts *, nLA);
 
   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];
 }
 
 
@@ -295,15 +276,15 @@ set_goto_map (void)
   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--)
 	{
-	  symbol = accessing_symbol[sp->shifts[i]];
+	  symbol = state_table[sp->shifts[i]].accessing_symbol;
 
 	  if (ISTOKEN (symbol))
 	    break;
@@ -329,8 +310,8 @@ set_goto_map (void)
   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)
     {
@@ -338,7 +319,7 @@ set_goto_map (void)
       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;
@@ -349,12 +330,14 @@ 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.  |
+`----------------------------------------------------------*/
 
 static int
 map_goto (int state, int symbol)
@@ -379,8 +362,8 @@ map_goto (int state, int symbol)
 	high = middle - 1;
     }
 
-  berror ("map_goto");
-/* NOTREACHED */
+  assert (0);
+  /* NOTREACHED */
   return 0;
 }
 
@@ -402,17 +385,17 @@ initialize_F (void)
   int nwords;
 
   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;
   for (i = 0; i < ngotos; i++)
     {
       stateno = to_state[i];
-      sp = shift_table[stateno];
+      sp = state_table[stateno].shift_table;
 
       if (sp)
 	{
@@ -420,7 +403,7 @@ initialize_F (void)
 
 	  for (j = 0; j < k; j++)
 	    {
-	      symbol = accessing_symbol[sp->shifts[j]];
+	      symbol = state_table[sp->shifts[j]].accessing_symbol;
 	      if (ISVAR (symbol))
 		break;
 	      SETBIT (rowp, symbol);
@@ -428,14 +411,14 @@ initialize_F (void)
 
 	  for (; j < k; j++)
 	    {
-	      symbol = accessing_symbol[sp->shifts[j]];
+	      symbol = state_table[sp->shifts[j]].accessing_symbol;
 	      if (nullable[symbol])
 		edge[nedges++] = map_goto (stateno, symbol);
 	    }
 
 	  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];
@@ -451,13 +434,10 @@ initialize_F (void)
   digraph (reads);
 
   for (i = 0; i < ngotos; i++)
-    {
-      if (reads[i])
-	FREE (reads[i]);
-    }
+    XFREE (reads[i]);
 
-  FREE (reads);
-  FREE (edge);
+  XFREE (reads);
+  XFREE (edge);
 }
 
 
@@ -469,8 +449,8 @@ add_lookback_edge (int stateno, int ruleno, int gotono)
   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)
     {
@@ -482,7 +462,7 @@ add_lookback_edge (int stateno, int ruleno, int gotono)
 
   assert (found);
 
-  sp = NEW (shorts);
+  sp = XCALLOC (shorts, 1);
   sp->next = lookback[i];
   sp->value = gotono;
   lookback[i] = sp;
@@ -499,7 +479,7 @@ transpose (short **R_arg, int n)
   int i;
   int k;
 
-  nedges = NEW2 (n, short);
+  nedges = XCALLOC (short, n);
 
   for (i = 0; i < n; i++)
     {
@@ -511,22 +491,22 @@ 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)
 	{
-	  sp = NEW2 (k + 1, short);
+	  sp = XCALLOC (short, k + 1);
 	  new_R[i] = sp;
 	  temp_R[i] = sp;
 	  sp[k] = -1;
 	}
     }
 
-  FREE (nedges);
+  XFREE (nedges);
 
   for (i = 0; i < n; i++)
     {
@@ -538,7 +518,7 @@ transpose (short **R_arg, int n)
 	}
     }
 
-  FREE (temp_R);
+  XFREE (temp_R);
 
   return new_R;
 }
@@ -565,15 +545,15 @@ build_relations (void)
   short *states;
   short **new_includes;
 
-  includes = NEW2 (ngotos, short *);
-  edge = NEW2 (ngotos + 1, short);
-  states = NEW2 (maxrhs + 1, short);
+  includes = XCALLOC (short *, ngotos);
+  edge = XCALLOC (short, ngotos + 1);
+  states = XCALLOC (short, maxrhs () + 1);
 
   for (i = 0; i < ngotos; i++)
     {
       nedges = 0;
       state1 = from_state[i];
-      symbol1 = accessing_symbol[to_state[i]];
+      symbol1 = state_table[to_state[i]].accessing_symbol;
 
       for (rulep = derives[symbol1]; *rulep > 0; rulep++)
 	{
@@ -581,23 +561,23 @@ build_relations (void)
 	  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;
-	      sp = shift_table[stateno];
+	      sp = state_table[stateno].shift_table;
 	      k = sp->nshifts;
 
 	      for (j = 0; j < k; j++)
 		{
 		  stateno = sp->shifts[j];
-		  if (accessing_symbol[stateno] == symbol2)
+		  if (state_table[stateno].accessing_symbol == symbol2)
 		    break;
 		}
 
 	      states[length++] = stateno;
 	    }
 
-	  if (!consistent[stateno])
+	  if (!state_table[stateno].consistent)
 	    add_lookback_edge (stateno, *rulep, i);
 
 	  length--;
@@ -619,7 +599,7 @@ build_relations (void)
 
       if (nedges)
 	{
-	  includes[i] = shortp = NEW2 (nedges + 1, short);
+	  includes[i] = shortp = XCALLOC (short, nedges + 1);
 	  for (j = 0; j < nedges; j++)
 	    shortp[j] = edge[j];
 	  shortp[nedges] = -1;
@@ -630,14 +610,14 @@ build_relations (void)
 
   for (i = 0; i < ngotos; i++)
     if (includes[i])
-      FREE (includes[i]);
+      XFREE (includes[i]);
 
-  FREE (includes);
+  XFREE (includes);
 
   includes = new_includes;
 
-  FREE (edge);
-  FREE (states);
+  XFREE (edge);
+  XFREE (states);
 }
 
 
@@ -650,12 +630,9 @@ compute_FOLLOWS (void)
   digraph (includes);
 
   for (i = 0; i < ngotos; i++)
-    {
-      if (includes[i])
-	FREE (includes[i]);
-    }
+    XFREE (includes[i]);
 
-  FREE (includes);
+  XFREE (includes);
 }
 
 
@@ -663,42 +640,23 @@ static void
 compute_lookaheads (void)
 {
   int i;
-  int n;
-  unsigned *fp1;
-  unsigned *fp2;
-  unsigned *fp3;
   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 < n; i++)
-    {
-      /* JF removed ref to freed storage */
-      for (sp = lookback[i]; sp; sp = sptmp)
-	{
-	  sptmp = sp->next;
-	  FREE (sp);
-	}
-    }
 
-  FREE (lookback);
-  FREE (F);
+  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++;
+      }
+
+  /* Free LOOKBACK. */
+  for (i = 0; i < state_table[nstates].lookaheads; i++)
+    LIST_FREE (shorts, lookback[i]);
+
+  XFREE (lookback);
+  XFREE (F);
 }
 
 
@@ -708,10 +666,6 @@ lalr (void)
   tokensetsize = WORDSIZE (ntokens);
 
   set_state_table ();
-  set_accessing_symbol ();
-  set_shift_table ();
-  set_reduction_table ();
-  set_maxrhs ();
   initialize_LA ();
   set_goto_map ();
   initialize_F ();