20-fyi-more-deobf-conflicts.patch

[Akim Demaille]

Index: ChangeLog
from  Akim Demaille  <address@hidden>
        * src/conflicts.c (flush_shift, resolve_sr_conflict): De-obfuscate
        using the good o' techniques: arrays not pointers, variable
        locality, BITISSET, RESETBIT etc.
        
        
Index: src/conflicts.c
--- src/conflicts.c Sat, 01 Dec 2001 19:13:37 +0100 akim
+++ src/conflicts.c Sat, 01 Dec 2001 19:22:46 +0100 akim
@@ -57,21 +57,13 @@
 static void
 flush_shift (int state, int token)
 {
-  shifts *shiftp;
-  int k, i;
-
-  shiftp = state_table[state].shift_table;
+  shifts *shiftp = state_table[state].shift_table;
+  int i;
 
   if (shiftp)
-    {
-      k = shiftp->nshifts;
-      for (i = 0; i < k; i++)
-       {
-         if (shiftp->shifts[i]
-             && token == state_table[shiftp->shifts[i]].accessing_symbol)
-           (shiftp->shifts[i]) = 0;
-       }
-    }
+    for (i = 0; i < shiftp->nshifts; i++)
+      if (shiftp->shifts[i] && SHIFT_SYMBOL (shiftp, i) == token)
+       shiftp->shifts[i] = 0;
 }
 
 
@@ -86,22 +78,16 @@
 resolve_sr_conflict (int state, int lookaheadnum)
 {
   int i;
-  int mask;
-  unsigned *fp1;
-  unsigned *fp2;
-  int redprec;
+  /* find the rule to reduce by to get precedence of reduction  */
+  int redprec = rule_table[LAruleno[lookaheadnum]].prec;
   errs *errp = ERRS_ALLOC (ntokens + 1);
   short *errtokens = errp->errs;
 
-  /* find the rule to reduce by to get precedence of reduction  */
-  redprec = rule_table[LAruleno[lookaheadnum]].prec;
-
-  mask = 1;
-  fp1 = LA (lookaheadnum);
-  fp2 = lookaheadset;
   for (i = 0; i < ntokens; i++)
     {
-      if ((mask & *fp2 & *fp1) && sprec[i])
+      if (BITISSET (LA (lookaheadnum), i)
+         && BITISSET (lookaheadset, i)
+         && sprec[i])
        /* Shift-reduce conflict occurs for token number i
           and it has a precedence.
           The precedence of shifting is that of token i.  */
@@ -109,13 +95,15 @@
          if (sprec[i] < redprec)
            {
              log_resolution (state, lookaheadnum, i, _("reduce"));
-             *fp2 &= ~mask;    /* flush the shift for this token */
+             /* flush the shift for this token */
+             RESETBIT (lookaheadset, i);
              flush_shift (state, i);
            }
          else if (sprec[i] > redprec)
            {
              log_resolution (state, lookaheadnum, i, _("shift"));
-             *fp1 &= ~mask;    /* flush the reduce for this token */
+             /* flush the reduce for this token */
+             RESETBIT (LA (lookaheadnum), i);
            }
          else
            {
@@ -141,12 +129,14 @@
 
              if (sassoc[i] != right_assoc)
                {
-                 *fp2 &= ~mask;        /* flush the shift for this token */
+                 /* flush the shift for this token */
+                 RESETBIT (lookaheadset, i);
                  flush_shift (state, i);
                }
              if (sassoc[i] != left_assoc)
                {
-                 *fp1 &= ~mask;        /* flush the reduce for this token */
+                 /* flush the reduce for this token */
+                 RESETBIT (LA (lookaheadnum), i);
                }
              if (sassoc[i] == non_assoc)
                {
@@ -154,14 +144,6 @@
                  *errtokens++ = i;
                }
            }
-       }
-
-      mask <<= 1;
-      if (mask == 0)
-       {
-         mask = 1;
-         fp2++;
-         fp1++;
        }
     }
   errp->nerrs = errtokens - errp->errs;