16-fyi-all-reds.patch

[Akim Demaille]

Index: ChangeLog
from  Akim Demaille  <address@hidden>
        * src/state.h, src/state.c (reductions_new): New.
        * src/LR0.c (set_state_table): Let all the states have a
        `reductions', even if reduced to 0.
        (save_reductions): Adjust.
        * src/lalr.c (initialize_LA, initialize_lookaheads): Adjust.
        * src/print.c (print_reductions, print_actions): Adjust.
        * src/output.c (action_row): Adjust.
        
        
Index: src/LR0.c
--- src/LR0.c Thu, 27 Dec 2001 10:53:35 +0100 akim
+++ src/LR0.c Thu, 27 Dec 2001 10:59:26 +0100 akim
@@ -522,15 +522,8 @@
     }
 
   /* Make a reductions structure and copy the data into it.  */
-
-  if (count)
-    {
-      reductions *p = REDUCTIONS_ALLOC (count);
-      p->nreds = count;
-      shortcpy (p->rules, redset, count);
-
-      this_state->reductions = p;
-    }
+  this_state->reductions = reductions_new (count);
+  shortcpy (this_state->reductions->rules, redset, count);
 }
 
 
@@ -547,11 +540,14 @@
   for (sp = first_state; sp; sp = sp->next)
     {
       /* Pessimization, but simplification of the code: make sure all
-        the states have a shifts and errs, even if reduced to 0.  */
+        the states have a shifts, errs, and reductions, even if
+        reduced to 0.  */
       if (!sp->shifts)
        sp->shifts = shifts_new (0);
       if (!sp->errs)
        sp->errs = errs_new (0);
+      if (!sp->reductions)
+       sp->reductions = reductions_new (0);
 
       state_table[sp->number] = sp;
     }
Index: src/lalr.c
--- src/lalr.c Thu, 27 Dec 2001 10:29:38 +0100 akim
+++ src/lalr.c Thu, 27 Dec 2001 11:08:54 +0100 akim
@@ -137,7 +137,6 @@
   int i;
   int j;
   short *np;
-  reductions *rp;
 
   /* Avoid having to special case 0.  */
   if (!nLA)
@@ -150,9 +149,8 @@
   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];
+      for (j = 0; j < state_table[i]->reductions->nreds; j++)
+       *np++ = state_table[i]->reductions->rules[j];
 }
 
 
@@ -525,8 +523,12 @@
       reductions *rp = state_table[i]->reductions;
       shifts *sp = state_table[i]->shifts;
 
-      if (rp
-         && (rp->nreds > 1 || (sp->nshifts && SHIFT_IS_SHIFT (sp, 0))))
+      /* 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
        state_table[i]->consistent = 1;
Index: src/output.c
--- src/output.c Thu, 27 Dec 2001 10:53:35 +0100 akim
+++ src/output.c Thu, 27 Dec 2001 11:02:56 +0100 akim
@@ -326,7 +326,6 @@
   int i;
   int default_rule = 0;
   reductions *redp = state->reductions;
-  int nreds = redp ? redp->nreds : 0;
   shifts *shiftp = state->shifts;
   errs *errp = state->errs;
   /* set nonzero to inhibit having any default reduction */
@@ -335,7 +334,7 @@
   for (i = 0; i < ntokens; i++)
     actrow[i] = 0;
 
-  if (nreds >= 1)
+  if (redp->nreds >= 1)
     {
       int j;
       /* loop over all the rules available here which require
@@ -384,7 +383,7 @@
   /* Now find the most common reduction and make it the default action
      for this state.  */
 
-  if (nreds >= 1 && !nodefault)
+  if (redp->nreds >= 1 && !nodefault)
     {
       if (state->consistent)
        default_rule = redp->rules[0];
Index: src/print.c
--- src/print.c Thu, 27 Dec 2001 10:53:35 +0100 akim
+++ src/print.c Thu, 27 Dec 2001 11:13:48 +0100 akim
@@ -167,6 +167,9 @@
   errs *errp = state->errs;
   int nodefault = 0;
 
+  if (redp->nreds == 0)
+    return;
+
   if (state->consistent)
     {
       int rule = redp->rules[0];
@@ -303,7 +306,7 @@
   reductions *redp = state->reductions;
   shifts *shiftp = state->shifts;
 
-  if (!shiftp->nshifts && !redp)
+  if (shiftp->nshifts == 0 && redp->nreds == 0)
     {
       if (final_state == state->number)
        fprintf (out, _("    $default\taccept\n"));
@@ -314,8 +317,7 @@
 
   print_shifts (out, state);
   print_errs (out, state);
-  if (redp)
-    print_reductions (out, state);
+  print_reductions (out, state);
   print_gotos (out, state);
 }
 
Index: src/state.c
--- src/state.c Thu, 27 Dec 2001 10:53:35 +0100 akim
+++ src/state.c Thu, 27 Dec 2001 10:59:15 +0100 akim
@@ -64,3 +64,19 @@
   memcpy (res->errs, src->errs, src->nerrs);
   return res;
 }
+
+/*-------------------------------------.
+| Create a new array of N reductions.  |
+`-------------------------------------*/
+
+#define REDUCTIONS_ALLOC(Nreductions)                                  \
+  (reductions *) xcalloc ((unsigned) (sizeof (reductions)              \
+                                  + (Nreductions - 1) * sizeof (short)), 1)
+
+reductions *
+reductions_new (int n)
+{
+  reductions *res = REDUCTIONS_ALLOC (n);
+  res->nreds = n;
+  return res;
+}
Index: src/state.h
--- src/state.h Thu, 27 Dec 2001 10:53:35 +0100 akim
+++ src/state.h Thu, 27 Dec 2001 10:55:57 +0100 akim
@@ -158,10 +158,7 @@
   short rules[1];
 } reductions;
 
-#define REDUCTIONS_ALLOC(Nreductions)                                  \
-  (reductions *) xcalloc ((unsigned) (sizeof (reductions)              \
-                                  + (Nreductions - 1) * sizeof (short)), 1)
-
+reductions *reductions_new PARAMS ((int n));
 
 
 /*----------.