svn merge ^/branches/released .

1 files changed, 772 insertions, 0 deletions

diff --git a/tools/bison++/conflict.cc b/tools/bison++/conflict.cc
new file mode 100644
index 000000000..8a3cd4902
--- /dev/null
+++ b/tools/bison++/conflict.cc
@@ -0,0 +1,772 @@
+/* Find and resolve or report look-ahead conflicts for bison,
+   Copyright (C) 1984, 1989 Free Software Foundation, Inc.
+
+This file is part of Bison, the GNU Compiler Compiler.
+
+Bison is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+Bison is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Bison; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#ifdef _AIX
+ #pragma alloca
+#endif
+#include <stdio.h>
+#include "system.h"
+#include "machine.h"
+#include "new.h"
+#include "files.h"
+#include "gram.h"
+#include "state.h"
+
+
+
+#ifdef __GNUC__
+#define alloca __builtin_alloca
+
+#elif defined (HAVE_ALLOCA_H) 
+#include <alloca.h>
+
+#elif defined( _AIX)
+
+#elif defined( _MSDOS)
+
+#ifndef alloca
+#include <malloc.h>
+#define alloca _alloca
+#endif /* ndef alloca */
+
+#else /* not msdos */
+#ifdef _MSC_VER
+#include <malloc.h>
+#define alloca _alloca
+#else
+char *alloca ();
+#endif
+
+#endif /* msdos ? */
+
+extern char **tags;
+extern int tokensetsize;
+extern char *consistent;
+extern short *accessing_symbol;
+extern shifts **shift_table;
+extern unsigned *LA;
+extern short *LAruleno;
+extern short *lookaheads;
+extern int verboseflag;
+
+void set_conflicts(int);
+void resolve_sr_conflict(int,int);
+void flush_shift(int,int);
+void log_resolution(int,int,int,char*);
+void total_conflicts();
+void count_sr_conflicts(int);
+void count_rr_conflicts(int);
+
+char any_conflicts;
+char *conflicts;
+errs **err_table;
+int expected_conflicts;
+
+
+static unsigned *shiftset;
+static unsigned *lookaheadset;
+static int src_total;
+static int rrc_total;
+static int src_count;
+static int rrc_count;
+
+
+void
+initialize_conflicts()
+{
+  register int i;
+/*  register errs *sp; JF unused */
+
+  conflicts = NEW2(nstates, char);
+  shiftset = NEW2(tokensetsize, unsigned);
+  lookaheadset = NEW2(tokensetsize, unsigned);
+
+  err_table = NEW2(nstates, errs *);
+
+  any_conflicts = 0;
+
+  for (i = 0; i < nstates; i++)
+    set_conflicts(i);
+}
+
+
+void
+set_conflicts(int state)
+{
+  register int i;
+  register int k;
+  register shifts *shiftp;
+  register unsigned *fp2;
+  register unsigned *fp3;
+  register unsigned *fp4;
+  register unsigned *fp1;
+  register int symbol;
+
+  if (consistent[state]) return;
+
+  for (i = 0; i < tokensetsize; i++)
+    lookaheadset[i] = 0;
+
+  shiftp = shift_table[state];
+  if (shiftp)
+    {
+      k = shiftp->nshifts;
+      for (i = 0; i < k; i++)
+	{
+	  symbol = accessing_symbol[shiftp->internalShifts[i]];
+	  if (ISVAR(symbol)) break;
+	  SETBIT(lookaheadset, symbol);
+	}
+    }
+
+  k = lookaheads[state + 1];
+  fp4 = lookaheadset + tokensetsize;
+
+  /* loop over all rules which require lookahead in this state */
+  /* first check for shift-reduce conflict, and try to resolve using precedence  */
+
+  for (i = lookaheads[state]; i < k; i++)
+    if (rprec[LAruleno[i]])
+      {
+	fp1 = LA + i * tokensetsize;
+	fp2 = fp1;
+	fp3 = lookaheadset;
+  
+	while (fp3 < fp4)
+	  {
+	    if (*fp2++ & *fp3++)
+	      {
+		resolve_sr_conflict(state, i);
+		break;
+	      }
+	  }
+      }
+
+  /* loop over all rules which require lookahead in this state */
+  /* Check for conflicts not resolved above.  */
+
+  for (i = lookaheads[state]; i < k; i++)
+    {
+      fp1 = LA + i * tokensetsize;
+      fp2 = fp1;
+      fp3 = lookaheadset;
+
+      while (fp3 < fp4)
+	{
+	  if (*fp2++ & *fp3++)
+	    {
+	      conflicts[state] = 1;
+	      any_conflicts = 1;
+	    }
+	}
+
+      fp2 = fp1;
+      fp3 = lookaheadset;
+
+      while (fp3 < fp4)
+	*fp3++ |= *fp2++;
+    }
+}
+
+
+
+/* Attempt to resolve shift-reduce conflict for one rule
+by means of precedence declarations.
+It has already been checked that the rule has a precedence.
+A conflict is resolved by modifying the shift or reduce tables
+so that there is no longer a conflict.  */
+
+void
+resolve_sr_conflict(int state, int lookaheadnum)
+{
+  register int i;
+  register int mask;
+  register unsigned *fp1;
+  register unsigned *fp2;
+  register int redprec;
+  /* Extra parens avoid errors on Ultrix 4.3.  */
+  errs *errp = (errs *) alloca ((sizeof(errs) + ntokens * sizeof(short)));
+  short *errtokens = errp->internalErrs;
+
+  /* find the rule to reduce by to get precedence of reduction  */
+  redprec = rprec[LAruleno[lookaheadnum]];
+
+  mask = 1;
+  fp1 = LA + lookaheadnum * tokensetsize;
+  fp2 = lookaheadset;
+  for (i = 0; i < ntokens; i++)
+    {
+      if ((mask & *fp2 & *fp1) && sprec[i])
+	/* Shift-reduce conflict occurs for token number i
+	   and it has a precedence.
+	   The precedence of shifting is that of token i.  */
+	{
+	  if (sprec[i] < redprec)
+	    {
+	      if (verboseflag) log_resolution(state, lookaheadnum, i, "reduce");
+	      *fp2 &= ~mask;  /* flush the shift for this token */
+	      flush_shift(state, i);
+	    }
+	  else if (sprec[i] > redprec)
+	    {
+	      if (verboseflag) log_resolution(state, lookaheadnum, i, "shift");
+	      *fp1 &= ~mask;  /* flush the reduce for this token */
+	    }
+	  else
+	    {
+	      /* Matching precedence levels.
+		 For left association, keep only the reduction.
+		 For right association, keep only the shift.
+		 For nonassociation, keep neither.  */
+
+	      switch (sassoc[i])
+		{
+
+		case RIGHT_ASSOC:
+	          if (verboseflag) log_resolution(state, lookaheadnum, i, "shift");
+		  break;
+
+		case LEFT_ASSOC:
+	          if (verboseflag) log_resolution(state, lookaheadnum, i, "reduce");
+		  break;
+
+		case NON_ASSOC:
+	          if (verboseflag) log_resolution(state, lookaheadnum, i, "an error");
+		  break;
+		}
+
+	      if (sassoc[i] != RIGHT_ASSOC)
+		{
+		  *fp2 &= ~mask;  /* flush the shift for this token */
+		  flush_shift(state, i);
+		}
+	      if (sassoc[i] != LEFT_ASSOC)
+	        {
+		  *fp1 &= ~mask;  /* flush the reduce for this token */
+		}
+	      if (sassoc[i] == NON_ASSOC)
+		{
+		  /* Record an explicit error for this token.  */
+		  *errtokens++ = i;
+		}
+	    }
+	}
+
+      mask <<= 1;
+      if (mask == 0)
+	{
+	  mask = 1;
+	  fp2++;  fp1++;
+	}
+    }
+  errp->nerrs = errtokens - errp->internalErrs;
+  if (errp->nerrs)
+    {
+      /* Some tokens have been explicitly made errors.  Allocate
+	 a permanent errs structure for this state, to record them.  */
+      i = (char *) errtokens - (char *) errp;
+      err_table[state] = (errs *) xmalloc ((unsigned int)i);
+      bcopy (errp, err_table[state], i);
+    }
+  else
+    err_table[state] = 0;
+}
+
+
+
+/* turn off the shift recorded for the specified token in the specified state.
+Used when we resolve a shift-reduce conflict in favor of the reduction.  */
+
+void
+flush_shift(int state, int token)
+{
+  register shifts *shiftp;
+  register int k, i;
+/*  register unsigned symbol; JF unused */
+
+  shiftp = shift_table[state];
+
+  if (shiftp)
+    {
+      k = shiftp->nshifts;
+      for (i = 0; i < k; i++)
+	{
+	  if (shiftp->internalShifts[i] && token == accessing_symbol[shiftp->internalShifts[i]])
+	    (shiftp->internalShifts[i]) = 0;
+	}
+    }
+}
+
+
+void
+log_resolution(int state, int LAno, int token, char* resolution)
+{
+  fprintf(foutput,
+	  "Conflict in state %d between rule %d and token %s resolved as %s.\n",
+	  state, LAruleno[LAno], tags[token], resolution);
+}
+
+
+void
+conflict_log()
+{
+  register int i;
+
+  src_total = 0;
+  rrc_total = 0;
+
+  for (i = 0; i < nstates; i++)
+    {
+      if (conflicts[i])
+	{
+	  count_sr_conflicts(i);
+	  count_rr_conflicts(i);
+	  src_total += src_count;
+	  rrc_total += rrc_count;
+	}
+    }
+
+  total_conflicts();
+}
+  
+
+void
+verbose_conflict_log()
+{
+  register int i;
+
+  src_total = 0;
+  rrc_total = 0;
+
+  for (i = 0; i < nstates; i++)
+    {
+      if (conflicts[i])
+	{
+	  count_sr_conflicts(i);
+	  count_rr_conflicts(i);
+	  src_total += src_count;
+	  rrc_total += rrc_count;
+
+	  fprintf(foutput, "State %d contains", i);
+
+	  if (src_count == 1)
+	    fprintf(foutput, " 1 shift/reduce conflict");
+	  else if (src_count > 1)
+	    fprintf(foutput, " %d shift/reduce conflicts", src_count);
+
+	  if (src_count > 0 && rrc_count > 0)
+	    fprintf(foutput, " and");
+
+	  if (rrc_count == 1)
+	    fprintf(foutput, " 1 reduce/reduce conflict");
+	  else if (rrc_count > 1)
+	    fprintf(foutput, " %d reduce/reduce conflicts", rrc_count);
+
+	  putc('.', foutput);
+	  putc('\n', foutput);
+	}
+    }
+
+  total_conflicts();
+}
+
+
+void
+total_conflicts()
+{
+  extern int fixed_outfiles;
+
+  if (src_total == expected_conflicts && rrc_total == 0)
+    return;
+
+  if (fixed_outfiles)
+    {
+      /* If invoked under the name `yacc', use the output format
+	 specified by POSIX.  */
+      fprintf(stderr, "conflicts: ");
+      if (src_total > 0)
+	fprintf(stderr, " %d shift/reduce", src_total);
+      if (src_total > 0 && rrc_total > 0)
+	fprintf(stderr, ",");
+      if (rrc_total > 0)
+	fprintf(stderr, " %d reduce/reduce", rrc_total);
+      putc('\n', stderr);
+    }
+  else
+    {
+      fprintf(stderr, "%s contains", infile);
+
+      if (src_total == 1)
+	fprintf(stderr, " 1 shift/reduce conflict");
+      else if (src_total > 1)
+	fprintf(stderr, " %d shift/reduce conflicts", src_total);
+
+      if (src_total > 0 && rrc_total > 0)
+	fprintf(stderr, " and");
+
+      if (rrc_total == 1)
+	fprintf(stderr, " 1 reduce/reduce conflict");
+      else if (rrc_total > 1)
+	fprintf(stderr, " %d reduce/reduce conflicts", rrc_total);
+
+      putc('.', stderr);
+      putc('\n', stderr);
+    }
+}
+
+
+void
+count_sr_conflicts(int state)
+{
+  register int i;
+  register int k;
+  register int mask;
+  register shifts *shiftp;
+  register unsigned *fp1;
+  register unsigned *fp2;
+  register unsigned *fp3;
+  register int symbol;
+
+  src_count = 0;
+
+  shiftp = shift_table[state];
+  if (!shiftp) return;
+
+  for (i = 0; i < tokensetsize; i++)
+    {
+      shiftset[i] = 0;
+      lookaheadset[i] = 0;
+    }
+
+  k = shiftp->nshifts;
+  for (i = 0; i < k; i++)
+    {
+      if (! shiftp->internalShifts[i]) continue;
+      symbol = accessing_symbol[shiftp->internalShifts[i]];
+      if (ISVAR(symbol)) break;
+      SETBIT(shiftset, symbol);
+    }
+
+  k = lookaheads[state + 1];
+  fp3 = lookaheadset + tokensetsize;
+
+  for (i = lookaheads[state]; i < k; i++)
+    {
+      fp1 = LA + i * tokensetsize;
+      fp2 = lookaheadset;
+
+      while (fp2 < fp3)
+	*fp2++ |= *fp1++;
+    }
+
+  fp1 = shiftset;
+  fp2 = lookaheadset;
+
+  while (fp2 < fp3)
+    *fp2++ &= *fp1++;
+
+  mask = 1;
+  fp2 = lookaheadset;
+  for (i = 0; i < ntokens; i++)
+    {
+      if (mask & *fp2)
+	src_count++;
+
+      mask <<= 1;
+      if (mask == 0)
+	{
+	  mask = 1;
+	  fp2++;
+	}
+    }
+}
+
+
+void
+count_rr_conflicts(int state)
+{
+  register int i;
+  register int j;
+  register int count;
+  register unsigned mask;
+  register unsigned *baseword;
+  register unsigned *wordp;
+  register int m;
+  register int n;
+
+  rrc_count = 0;
+
+  m = lookaheads[state];
+  n = lookaheads[state + 1];
+
+  if (n - m < 2) return;
+
+  mask = 1;
+  baseword = LA + m * tokensetsize;
+  for (i = 0; i < ntokens; i++)
+    {
+      wordp = baseword;
+
+      count = 0;
+      for (j = m; j < n; j++)
+	{
+	  if (mask & *wordp)
+	    count++;
+
+	  wordp += tokensetsize;
+	}
+
+      if (count >= 2) rrc_count++;
+
+      mask <<= 1;
+      if (mask == 0)
+	{
+	  mask = 1;
+	  baseword++;
+	}
+    }
+}
+
+
+void
+print_reductions(int state)
+{
+  register int i;
+  register int j;
+  register int k;
+  register unsigned *fp1;
+  register unsigned *fp2;
+  register unsigned *fp3;
+  register unsigned *fp4;
+  register int rule;
+  register int symbol;
+  register unsigned mask;
+  register int m;
+  register int n;
+  register int default_LA;
+  register int default_rule;
+  register int cmax;
+  register int count;
+  register shifts *shiftp;
+  register errs *errp;
+  int nodefault = 0;
+
+  for (i = 0; i < tokensetsize; i++)
+    shiftset[i] = 0;
+
+  shiftp = shift_table[state];
+  if (shiftp)
+    {
+      k = shiftp->nshifts;
+      for (i = 0; i < k; i++)
+	{
+	  if (! shiftp->internalShifts[i]) continue;
+	  symbol = accessing_symbol[shiftp->internalShifts[i]];
+	  if (ISVAR(symbol)) break;
+	  /* if this state has a shift for the error token,
+	     don't use a default rule.  */
+	  if (symbol == error_token_number) nodefault = 1;
+	  SETBIT(shiftset, symbol);
+	}
+    }
+
+  errp = err_table[state];
+  if (errp)
+    {
+      k = errp->nerrs;
+      for (i = 0; i < k; i++)
+	{
+	  if (! errp->internalErrs[i]) continue;
+	  symbol = errp->internalErrs[i];
+	  SETBIT(shiftset, symbol);
+	}
+    }
+
+  m = lookaheads[state];
+  n = lookaheads[state + 1];
+
+  if (n - m == 1 && ! nodefault)
+    {
+      default_rule = LAruleno[m];
+
+      fp1 = LA + m * tokensetsize;
+      fp2 = shiftset;
+      fp3 = lookaheadset;
+      fp4 = lookaheadset + tokensetsize;
+
+      while (fp3 < fp4)
+	*fp3++ = *fp1++ & *fp2++;
+
+      mask = 1;
+      fp3 = lookaheadset;
+
+      for (i = 0; i < ntokens; i++)
+	{
+	  if (mask & *fp3)
+	    fprintf(foutput, "    %-4s\t[reduce using rule %d (%s)]\n",
+		    tags[i], default_rule, tags[rlhs[default_rule]]);
+
+	  mask <<= 1;
+	  if (mask == 0)
+	    {
+	      mask = 1;
+	      fp3++;
+	    }
+	}
+
+      fprintf(foutput, "    $default\treduce using rule %d (%s)\n\n",
+	      default_rule, tags[rlhs[default_rule]]);
+    }
+  else if (n - m >= 1)
+    {
+      cmax = 0;
+      default_LA = -1;
+      fp4 = lookaheadset + tokensetsize;
+
+      if (! nodefault)
+	for (i = m; i < n; i++)
+	  {
+	    fp1 = LA + i * tokensetsize;
+	    fp2 = shiftset;
+	    fp3 = lookaheadset;
+  
+	    while (fp3 < fp4)
+	      *fp3++ = *fp1++ & ( ~ (*fp2++));
+  
+	    count = 0;
+	    mask = 1;
+	    fp3 = lookaheadset;
+	    for (j = 0; j < ntokens; j++)
+	      {
+		if (mask & *fp3)
+		  count++;
+  
+		mask <<= 1;
+		if (mask == 0)
+		  {
+		    mask = 1;
+		    fp3++;
+		  }
+	      }
+  
+	    if (count > cmax)
+	      {
+		cmax = count;
+		default_LA = i;
+		default_rule = LAruleno[i];
+	      }
+  
+	    fp2 = shiftset;
+	    fp3 = lookaheadset;
+  
+	    while (fp3 < fp4)
+	      *fp2++ |= *fp3++;
+	  }
+
+      for (i = 0; i < tokensetsize; i++)
+        shiftset[i] = 0;
+
+      if (shiftp)
+        {
+          k = shiftp->nshifts;
+          for (i = 0; i < k; i++)
+	    {
+	      if (! shiftp->internalShifts[i]) continue;
+	      symbol = accessing_symbol[shiftp->internalShifts[i]];
+	      if (ISVAR(symbol)) break;
+	      SETBIT(shiftset, symbol);
+	    }
+        }
+
+      mask = 1;
+      fp1 = LA + m * tokensetsize;
+      fp2 = shiftset;
+      for (i = 0; i < ntokens; i++)
+	{
+	  int defaulted = 0;
+
+	  if (mask & *fp2)
+	    count = 1;
+	  else
+	    count = 0;
+
+	  fp3 = fp1;
+	  for (j = m; j < n; j++)
+	    {
+	      if (mask & *fp3)
+		{
+		  if (count == 0)
+		    {
+		      if (j != default_LA)
+			{
+			  rule = LAruleno[j];
+			  fprintf(foutput, "    %-4s\treduce using rule %d (%s)\n",
+				  tags[i], rule, tags[rlhs[rule]]);
+			}
+		      else defaulted = 1;
+
+		      count++;
+		    }
+		  else
+		    {
+		      if (defaulted)
+			{
+			  rule = LAruleno[default_LA];
+			  fprintf(foutput, "    %-4s\treduce using rule %d (%s)\n",
+				  tags[i], rule, tags[rlhs[rule]]);
+			  defaulted = 0;
+			}
+		      rule = LAruleno[j];
+		      fprintf(foutput, "    %-4s\t[reduce using rule %d (%s)]\n",
+			      tags[i], rule, tags[rlhs[rule]]);
+		    }
+		}
+
+	      fp3 += tokensetsize;
+	    }
+
+	  mask <<= 1;
+	  if (mask == 0)
+	    {
+	      mask = 1;
+	      /* This used to be fp1, but I think fp2 is right
+		 because fp2 is where the words are fetched to test with mask
+		 in this loop.  */
+	      fp2++;
+	    }
+	}
+
+      if (default_LA >= 0)
+	{
+	  fprintf(foutput, "    $default\treduce using rule %d (%s)\n",
+		  default_rule, tags[rlhs[default_rule]]);
+	}
+
+      putc('\n', foutput);
+    }
+}
+
+
+void
+finalize_conflicts()
+{
+  FREE(conflicts);
+  FREE(shiftset);
+  FREE(lookaheadset);
+}