Regen.

[bison.git] / src / lalr.c

diff --git a/src/lalr.c b/src/lalr.c
index be178b8d5ee20e46f6b9e966230d1568036a686d..c16c6f52dafaea945a222c3f6103f32c6c312cf2 100644 (file)
--- a/src/lalr.c
+++ b/src/lalr.c
@@ -24,8 +24,10 @@
    tokens they accept.  */
 
 #include "system.h"
    tokens they accept.  */
 
 #include "system.h"

+#include "reader.h"

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

+#include "symtab.h"

 #include "gram.h"
 #include "complain.h"
 #include "lalr.h"
 #include "gram.h"
 #include "complain.h"
 #include "lalr.h"


@@ -34,7 +36,7 @@
 #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;
 
 int tokensetsize;
 short *LAruleno;


@@ -137,7 +139,6 @@ initialize_LA (void)
   int i;
   int j;
   short *np;
   int i;
   int j;
   short *np;

-  reductions *rp;

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


@@ -149,10 +150,9 @@ initialize_LA (void)
 
   np = LAruleno;
   for (i = 0; i < nstates; i++)
 
   np = LAruleno;
   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++ = states[i]->reductions->rules[j];

 }
 
 
 }
 
 


@@ -168,16 +168,14 @@ 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)
        {

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

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

-         goto_map[symbol]++;
+         goto_map[SHIFT_SYMBOL (sp, i)]++;

        }
     }
 
        }
     }
 


@@ -201,15 +199,12 @@ 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)
        {
       for (i = sp->nshifts - 1; i >= 0 && SHIFT_IS_GOTO (sp, i); --i)
        {

-         int state2 = sp->shifts[i];
-         int symbol = state_table[state2]->accessing_symbol;
-
-         int k = temp_map[symbol]++;
+         int k = temp_map[SHIFT_SYMBOL (sp, i)]++;

          from_state[k] = state;
          from_state[k] = state;

-         to_state[k] = state2;
+         to_state[k] = sp->shifts[i];

        }
     }
 
        }
     }
 


@@ -265,18 +260,15 @@ initialize_F (void)
   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++)

-       {
-         int symbol = state_table[sp->shifts[j]]->accessing_symbol;
-         SETBIT (F (i), symbol);
-       }
+       SETBIT (F (i), SHIFT_SYMBOL (sp, j));

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

-         int symbol = state_table[sp->shifts[j]]->accessing_symbol;
+         int symbol = SHIFT_SYMBOL (sp, j);

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


@@ -409,7 +401,7 @@ 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);


@@ -417,7 +409,7 @@ 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;
+      int symbol1 = states[to_state[i]]->accessing_symbol;

       short *rulep;
 
       for (rulep = derives[symbol1]; *rulep > 0; rulep++)
       short *rulep;
 
       for (rulep = derives[symbol1]; *rulep > 0; rulep++)


@@ -425,21 +417,21 @@ build_relations (void)
          int done;
          int length = 1;
          short *rp;
          int done;
          int length = 1;
          short *rp;

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

 
 

-         for (rp = ritem + rule_table[*rulep].rhs; *rp > 0; rp++)
+         for (rp = &ritem[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]];
+                 state = states[sp->shifts[j]];

                  if (state->accessing_symbol == *rp)
                    break;
                }
 
                  if (state->accessing_symbol == *rp)
                    break;
                }
 

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

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


@@ -454,7 +446,7 @@ 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);
+                 edge[nedges++] = map_goto (states1[--length], *rp);

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


@@ -472,7 +464,7 @@ build_relations (void)
     }
 
   XFREE (edge);
     }
 
   XFREE (edge);

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

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


@@ -530,28 +522,57 @@ initialize_lookaheads (void)
     {
       int k;
       int nlookaheads = 0;
     {
       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)
+{
+  int i, 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 (BITISSET (LA (states[i]->lookaheadsp + j), j))
+           fprintf (out, "   on %d (%s) -> rule %d\n",
+                    k, symbols[k]->tag,
+                    -LAruleno[states[i]->lookaheadsp + j] - 1);
+    }
+  fprintf (out, "Lookaheads: END\n");
+}
+

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


@@ -564,4 +585,7 @@ lalr (void)
   build_relations ();
   compute_FOLLOWS ();
   compute_lookaheads ();
   build_relations ();
   compute_FOLLOWS ();
   compute_lookaheads ();

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

 }
 }