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Comment:Enhance LEMON so that it generates the action table in such a way that no range check is needed on the lookahead table to verify that the next input token is valid. This makes the lookahead table slightly larger (about 120 bytes) but helps the parser to run faster.
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SHA3-256:7eb0198d0102e97e4b7ad9e359d95985e55e09c510ea4b360265ac8feb9ed814
User & Date: drh 2017-12-25 04:15:38
Context
2017-12-26
18:04
Add support for measuring and reporting coverage of the parser state machine using the SQLITE_TESTCTRL_PARSER_COVERAGE test-control. check-in: 1253a872 user: drh tags: lemon-improvements
2017-12-25
04:15
Enhance LEMON so that it generates the action table in such a way that no range check is needed on the lookahead table to verify that the next input token is valid. This makes the lookahead table slightly larger (about 120 bytes) but helps the parser to run faster. check-in: 7eb0198d user: drh tags: lemon-improvements
00:10
In the LEMON-generated parser, avoid unnecessary tests for the acceptance state. check-in: fdbb35c5 user: drh tags: lemon-improvements
Changes
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Changes to tool/lemon.c.

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  char *tokendest;         /* Code to execute to destroy token data */
  char *vardest;           /* Code for the default non-terminal destructor */
  char *filename;          /* Name of the input file */
  char *outname;           /* Name of the current output file */
  char *tokenprefix;       /* A prefix added to token names in the .h file */
  int nconflict;           /* Number of parsing conflicts */
  int nactiontab;          /* Number of entries in the yy_action[] table */

  int tablesize;           /* Total table size of all tables in bytes */
  int basisflag;           /* Print only basis configurations */
  int has_fallback;        /* True if any %fallback is seen in the grammar */
  int nolinenosflag;       /* True if #line statements should not be printed */
  char *argv0;             /* Name of the program */
};

................................................................................
    *aAction,                  /* The yy_action[] table under construction */
    *aLookahead;               /* A single new transaction set */
  int mnLookahead;             /* Minimum aLookahead[].lookahead */
  int mnAction;                /* Action associated with mnLookahead */
  int mxLookahead;             /* Maximum aLookahead[].lookahead */
  int nLookahead;              /* Used slots in aLookahead[] */
  int nLookaheadAlloc;         /* Slots allocated in aLookahead[] */


};

/* Return the number of entries in the yy_action table */
#define acttab_size(X) ((X)->nAction)

/* The value for the N-th entry in yy_action */
#define acttab_yyaction(X,N)  ((X)->aAction[N].action)

/* The value for the N-th entry in yy_lookahead */
#define acttab_yylookahead(X,N)  ((X)->aAction[N].lookahead)

................................................................................
void acttab_free(acttab *p){
  free( p->aAction );
  free( p->aLookahead );
  free( p );
}

/* Allocate a new acttab structure */
acttab *acttab_alloc(void){
  acttab *p = (acttab *) calloc( 1, sizeof(*p) );
  if( p==0 ){
    fprintf(stderr,"Unable to allocate memory for a new acttab.");
    exit(1);
  }
  memset(p, 0, sizeof(*p));


  return p;
}

/* Add a new action to the current transaction set.
**
** This routine is called once for each lookahead for a particular
** state.
................................................................................

/*
** Add the transaction set built up with prior calls to acttab_action()
** into the current action table.  Then reset the transaction set back
** to an empty set in preparation for a new round of acttab_action() calls.
**
** Return the offset into the action table of the new transaction.








*/
int acttab_insert(acttab *p){
  int i, j, k, n;
  assert( p->nLookahead>0 );

  /* Make sure we have enough space to hold the expanded action table
  ** in the worst case.  The worst case occurs if the transaction set
  ** must be appended to the current action table
  */
  n = p->mxLookahead + 1;
  if( p->nAction + n >= p->nActionAlloc ){
    int oldAlloc = p->nActionAlloc;
    p->nActionAlloc = p->nAction + n + p->nActionAlloc + 20;
    p->aAction = (struct lookahead_action *) realloc( p->aAction,
                          sizeof(p->aAction[0])*p->nActionAlloc);
    if( p->aAction==0 ){
      fprintf(stderr,"malloc failed\n");
................................................................................

  /* Scan the existing action table looking for an offset that is a
  ** duplicate of the current transaction set.  Fall out of the loop
  ** if and when the duplicate is found.
  **
  ** i is the index in p->aAction[] where p->mnLookahead is inserted.
  */

  for(i=p->nAction-1; i>=0; i--){
    if( p->aAction[i].lookahead==p->mnLookahead ){
      /* All lookaheads and actions in the aLookahead[] transaction
      ** must match against the candidate aAction[i] entry. */
      if( p->aAction[i].action!=p->mnAction ) continue;
      for(j=0; j<p->nLookahead; j++){
        k = p->aLookahead[j].lookahead - p->mnLookahead + i;
        if( k<0 || k>=p->nAction ) break;
................................................................................
    }
  }

  /* If no existing offsets exactly match the current transaction, find an
  ** an empty offset in the aAction[] table in which we can add the
  ** aLookahead[] transaction.
  */
  if( i<0 ){
    /* Look for holes in the aAction[] table that fit the current
    ** aLookahead[] transaction.  Leave i set to the offset of the hole.
    ** If no holes are found, i is left at p->nAction, which means the
    ** transaction will be appended. */

    for(i=0; i<p->nActionAlloc - p->mxLookahead; i++){
      if( p->aAction[i].lookahead<0 ){
        for(j=0; j<p->nLookahead; j++){
          k = p->aLookahead[j].lookahead - p->mnLookahead + i;
          if( k<0 ) break;
          if( p->aAction[k].lookahead>=0 ) break;
        }
        if( j<p->nLookahead ) continue;
................................................................................
        if( j==p->nAction ){
          break;  /* Fits in empty slots */
        }
      }
    }
  }
  /* Insert transaction set at index i. */







  for(j=0; j<p->nLookahead; j++){
    k = p->aLookahead[j].lookahead - p->mnLookahead + i;
    p->aAction[k] = p->aLookahead[j];
    if( k>=p->nAction ) p->nAction = k+1;
  }

  p->nLookahead = 0;

  /* Return the offset that is added to the lookahead in order to get the
  ** index into yy_action of the action */
  return i - p->mnLookahead;
}











/********************** From the file "build.c" *****************************/
/*
** Routines to construction the finite state machine for the LEMON
** parser generator.
*/

................................................................................
    stats_line("terminal symbols", lem.nterminal);
    stats_line("non-terminal symbols", lem.nsymbol - lem.nterminal);
    stats_line("total symbols", lem.nsymbol);
    stats_line("rules", lem.nrule);
    stats_line("states", lem.nxstate);
    stats_line("conflicts", lem.nconflict);
    stats_line("action table entries", lem.nactiontab);

    stats_line("total table size (bytes)", lem.tablesize);
  }
  if( lem.nconflict > 0 ){
    fprintf(stderr,"%d parsing conflicts.\n",lem.nconflict);
  }

  /* return 0 on success, 1 on failure. */
................................................................................
  }
  mxTknOfst = mnTknOfst = 0;
  mxNtOfst = mnNtOfst = 0;
  /* In an effort to minimize the action table size, use the heuristic
  ** of placing the largest action sets first */
  for(i=0; i<lemp->nxstate*2; i++) ax[i].iOrder = i;
  qsort(ax, lemp->nxstate*2, sizeof(ax[0]), axset_compare);
  pActtab = acttab_alloc();
  for(i=0; i<lemp->nxstate*2 && ax[i].nAction>0; i++){
    stp = ax[i].stp;
    if( ax[i].isTkn ){
      for(ap=stp->ap; ap; ap=ap->next){
        int action;
        if( ap->sp->index>=lemp->nterminal ) continue;
        action = compute_action(lemp, ap);
        if( action<0 ) continue;
        acttab_action(pActtab, ap->sp->index, action);
      }
      stp->iTknOfst = acttab_insert(pActtab);
      if( stp->iTknOfst<mnTknOfst ) mnTknOfst = stp->iTknOfst;
      if( stp->iTknOfst>mxTknOfst ) mxTknOfst = stp->iTknOfst;
    }else{
      for(ap=stp->ap; ap; ap=ap->next){
        int action;
        if( ap->sp->index<lemp->nterminal ) continue;
        if( ap->sp->index==lemp->nsymbol ) continue;
        action = compute_action(lemp, ap);
        if( action<0 ) continue;
        acttab_action(pActtab, ap->sp->index, action);
      }
      stp->iNtOfst = acttab_insert(pActtab);
      if( stp->iNtOfst<mnNtOfst ) mnNtOfst = stp->iNtOfst;
      if( stp->iNtOfst>mxNtOfst ) mxNtOfst = stp->iNtOfst;
    }
#if 0  /* Uncomment for a trace of how the yy_action[] table fills out */
    { int jj, nn;
      for(jj=nn=0; jj<pActtab->nAction; jj++){
        if( pActtab->aAction[jj].action<0 ) nn++;
................................................................................
  **                     shifting terminals.
  **  yy_reduce_ofst[]   For each state, the offset into yy_action for
  **                     shifting non-terminals after a reduce.
  **  yy_default[]       Default action for each state.
  */

  /* Output the yy_action table */
  lemp->nactiontab = n = acttab_size(pActtab);
  lemp->tablesize += n*szActionType;
  fprintf(out,"#define YY_ACTTAB_COUNT (%d)\n", n); lineno++;
  fprintf(out,"static const YYACTIONTYPE yy_action[] = {\n"); lineno++;
  for(i=j=0; i<n; i++){
    int action = acttab_yyaction(pActtab, i);
    if( action<0 ) action = lemp->noAction;
    if( j==0 ) fprintf(out," /* %5d */ ", i);
................................................................................
    }else{
      j++;
    }
  }
  fprintf(out, "};\n"); lineno++;

  /* Output the yy_lookahead table */

  lemp->tablesize += n*szCodeType;
  fprintf(out,"static const YYCODETYPE yy_lookahead[] = {\n"); lineno++;
  for(i=j=0; i<n; i++){
    int la = acttab_yylookahead(pActtab, i);
    if( la<0 ) la = lemp->nsymbol;
    if( j==0 ) fprintf(out," /* %5d */ ", i);
    fprintf(out, " %4d,", la);
................................................................................
    }
  }
  fprintf(out, "};\n"); lineno++;

  /* Output the yy_shift_ofst[] table */
  n = lemp->nxstate;
  while( n>0 && lemp->sorted[n-1]->iTknOfst==NO_OFFSET ) n--;
  fprintf(out, "#define YY_SHIFT_USE_DFLT (%d)\n", lemp->nactiontab); lineno++;
  fprintf(out, "#define YY_SHIFT_COUNT    (%d)\n", n-1); lineno++;
  fprintf(out, "#define YY_SHIFT_MIN      (%d)\n", mnTknOfst); lineno++;
  fprintf(out, "#define YY_SHIFT_MAX      (%d)\n", mxTknOfst); lineno++;
  fprintf(out, "static const %s yy_shift_ofst[] = {\n",
       minimum_size_type(mnTknOfst, lemp->nterminal+lemp->nactiontab, &sz));
       lineno++;
  lemp->tablesize += n*sz;
................................................................................
    }else{
      j++;
    }
  }
  fprintf(out, "};\n"); lineno++;

  /* Output the yy_reduce_ofst[] table */
  fprintf(out, "#define YY_REDUCE_USE_DFLT (%d)\n", mnNtOfst-1); lineno++;
  n = lemp->nxstate;
  while( n>0 && lemp->sorted[n-1]->iNtOfst==NO_OFFSET ) n--;
  fprintf(out, "#define YY_REDUCE_COUNT (%d)\n", n-1); lineno++;
  fprintf(out, "#define YY_REDUCE_MIN   (%d)\n", mnNtOfst); lineno++;
  fprintf(out, "#define YY_REDUCE_MAX   (%d)\n", mxNtOfst); lineno++;
  fprintf(out, "static const %s yy_reduce_ofst[] = {\n",
          minimum_size_type(mnNtOfst-1, mxNtOfst, &sz)); lineno++;
................................................................................
  }
  tplt_xfer(lemp->name, in, out, &lineno);

  /* Generate a table containing the symbolic name of every symbol
  */
  for(i=0; i<lemp->nsymbol; i++){
    lemon_sprintf(line,"\"%s\",",lemp->symbols[i]->name);
    fprintf(out,"  %-15s",line);
    if( (i&3)==3 ){ fprintf(out,"\n"); lineno++; }
  }
  if( (i&3)!=0 ){ fprintf(out,"\n"); lineno++; }
  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate a table containing a text string that describes every
  ** rule in the rule set of the grammar.  This information is used
  ** when tracing REDUCE actions.
  */
  for(i=0, rp=lemp->rule; rp; rp=rp->next, i++){







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  char *tokendest;         /* Code to execute to destroy token data */
  char *vardest;           /* Code for the default non-terminal destructor */
  char *filename;          /* Name of the input file */
  char *outname;           /* Name of the current output file */
  char *tokenprefix;       /* A prefix added to token names in the .h file */
  int nconflict;           /* Number of parsing conflicts */
  int nactiontab;          /* Number of entries in the yy_action[] table */
  int nlookaheadtab;       /* Number of entries in yy_lookahead[] */
  int tablesize;           /* Total table size of all tables in bytes */
  int basisflag;           /* Print only basis configurations */
  int has_fallback;        /* True if any %fallback is seen in the grammar */
  int nolinenosflag;       /* True if #line statements should not be printed */
  char *argv0;             /* Name of the program */
};

................................................................................
    *aAction,                  /* The yy_action[] table under construction */
    *aLookahead;               /* A single new transaction set */
  int mnLookahead;             /* Minimum aLookahead[].lookahead */
  int mnAction;                /* Action associated with mnLookahead */
  int mxLookahead;             /* Maximum aLookahead[].lookahead */
  int nLookahead;              /* Used slots in aLookahead[] */
  int nLookaheadAlloc;         /* Slots allocated in aLookahead[] */
  int nterminal;               /* Number of terminal symbols */
  int nsymbol;                 /* total number of symbols */
};

/* Return the number of entries in the yy_action table */
#define acttab_lookahead_size(X) ((X)->nAction)

/* The value for the N-th entry in yy_action */
#define acttab_yyaction(X,N)  ((X)->aAction[N].action)

/* The value for the N-th entry in yy_lookahead */
#define acttab_yylookahead(X,N)  ((X)->aAction[N].lookahead)

................................................................................
void acttab_free(acttab *p){
  free( p->aAction );
  free( p->aLookahead );
  free( p );
}

/* Allocate a new acttab structure */
acttab *acttab_alloc(int nsymbol, int nterminal){
  acttab *p = (acttab *) calloc( 1, sizeof(*p) );
  if( p==0 ){
    fprintf(stderr,"Unable to allocate memory for a new acttab.");
    exit(1);
  }
  memset(p, 0, sizeof(*p));
  p->nsymbol = nsymbol;
  p->nterminal = nterminal;
  return p;
}

/* Add a new action to the current transaction set.
**
** This routine is called once for each lookahead for a particular
** state.
................................................................................

/*
** Add the transaction set built up with prior calls to acttab_action()
** into the current action table.  Then reset the transaction set back
** to an empty set in preparation for a new round of acttab_action() calls.
**
** Return the offset into the action table of the new transaction.
**
** If the makeItSafe parameter is true, then the offset is chosen so that
** it is impossible to overread the yy_lookaside[] table regardless of
** the lookaside token.  This is done for the terminal symbols, as they
** come from external inputs and can contain syntax errors.  When makeItSafe
** is false, there is more flexibility in selecting offsets, resulting in
** a smaller table.  For non-terminal symbols, which are never syntax errors,
** makeItSafe can be false.
*/
int acttab_insert(acttab *p, int makeItSafe){
  int i, j, k, n, end;
  assert( p->nLookahead>0 );

  /* Make sure we have enough space to hold the expanded action table
  ** in the worst case.  The worst case occurs if the transaction set
  ** must be appended to the current action table
  */
  n = p->nsymbol + 1;
  if( p->nAction + n >= p->nActionAlloc ){
    int oldAlloc = p->nActionAlloc;
    p->nActionAlloc = p->nAction + n + p->nActionAlloc + 20;
    p->aAction = (struct lookahead_action *) realloc( p->aAction,
                          sizeof(p->aAction[0])*p->nActionAlloc);
    if( p->aAction==0 ){
      fprintf(stderr,"malloc failed\n");
................................................................................

  /* Scan the existing action table looking for an offset that is a
  ** duplicate of the current transaction set.  Fall out of the loop
  ** if and when the duplicate is found.
  **
  ** i is the index in p->aAction[] where p->mnLookahead is inserted.
  */
  end = makeItSafe ? p->mnLookahead : 0;
  for(i=p->nAction-1; i>=end; i--){
    if( p->aAction[i].lookahead==p->mnLookahead ){
      /* All lookaheads and actions in the aLookahead[] transaction
      ** must match against the candidate aAction[i] entry. */
      if( p->aAction[i].action!=p->mnAction ) continue;
      for(j=0; j<p->nLookahead; j++){
        k = p->aLookahead[j].lookahead - p->mnLookahead + i;
        if( k<0 || k>=p->nAction ) break;
................................................................................
    }
  }

  /* If no existing offsets exactly match the current transaction, find an
  ** an empty offset in the aAction[] table in which we can add the
  ** aLookahead[] transaction.
  */
  if( i<end ){
    /* Look for holes in the aAction[] table that fit the current
    ** aLookahead[] transaction.  Leave i set to the offset of the hole.
    ** If no holes are found, i is left at p->nAction, which means the
    ** transaction will be appended. */
    i = makeItSafe ? p->mnLookahead : 0;
    for(; i<p->nActionAlloc - p->mxLookahead; i++){
      if( p->aAction[i].lookahead<0 ){
        for(j=0; j<p->nLookahead; j++){
          k = p->aLookahead[j].lookahead - p->mnLookahead + i;
          if( k<0 ) break;
          if( p->aAction[k].lookahead>=0 ) break;
        }
        if( j<p->nLookahead ) continue;
................................................................................
        if( j==p->nAction ){
          break;  /* Fits in empty slots */
        }
      }
    }
  }
  /* Insert transaction set at index i. */
#if 0
  printf("Acttab:");
  for(j=0; j<p->nLookahead; j++){
    printf(" %d", p->aLookahead[j].lookahead);
  }
  printf(" inserted at %d\n", i);
#endif
  for(j=0; j<p->nLookahead; j++){
    k = p->aLookahead[j].lookahead - p->mnLookahead + i;
    p->aAction[k] = p->aLookahead[j];
    if( k>=p->nAction ) p->nAction = k+1;
  }
  if( makeItSafe && i+p->nterminal>p->nAction ) p->nAction = i+p->nterminal;
  p->nLookahead = 0;

  /* Return the offset that is added to the lookahead in order to get the
  ** index into yy_action of the action */
  return i - p->mnLookahead;
}

/*
** Return the size of the action table without the trailing syntax error
** entries.
*/
int acttab_action_size(acttab *p){
  int n = p->nAction;
  while( n>0 && p->aAction[n-1].lookahead<0 ){ n--; }
  return n;
}

/********************** From the file "build.c" *****************************/
/*
** Routines to construction the finite state machine for the LEMON
** parser generator.
*/

................................................................................
    stats_line("terminal symbols", lem.nterminal);
    stats_line("non-terminal symbols", lem.nsymbol - lem.nterminal);
    stats_line("total symbols", lem.nsymbol);
    stats_line("rules", lem.nrule);
    stats_line("states", lem.nxstate);
    stats_line("conflicts", lem.nconflict);
    stats_line("action table entries", lem.nactiontab);
    stats_line("lookahead table entries", lem.nlookaheadtab);
    stats_line("total table size (bytes)", lem.tablesize);
  }
  if( lem.nconflict > 0 ){
    fprintf(stderr,"%d parsing conflicts.\n",lem.nconflict);
  }

  /* return 0 on success, 1 on failure. */
................................................................................
  }
  mxTknOfst = mnTknOfst = 0;
  mxNtOfst = mnNtOfst = 0;
  /* In an effort to minimize the action table size, use the heuristic
  ** of placing the largest action sets first */
  for(i=0; i<lemp->nxstate*2; i++) ax[i].iOrder = i;
  qsort(ax, lemp->nxstate*2, sizeof(ax[0]), axset_compare);
  pActtab = acttab_alloc(lemp->nsymbol, lemp->nterminal);
  for(i=0; i<lemp->nxstate*2 && ax[i].nAction>0; i++){
    stp = ax[i].stp;
    if( ax[i].isTkn ){
      for(ap=stp->ap; ap; ap=ap->next){
        int action;
        if( ap->sp->index>=lemp->nterminal ) continue;
        action = compute_action(lemp, ap);
        if( action<0 ) continue;
        acttab_action(pActtab, ap->sp->index, action);
      }
      stp->iTknOfst = acttab_insert(pActtab, 1);
      if( stp->iTknOfst<mnTknOfst ) mnTknOfst = stp->iTknOfst;
      if( stp->iTknOfst>mxTknOfst ) mxTknOfst = stp->iTknOfst;
    }else{
      for(ap=stp->ap; ap; ap=ap->next){
        int action;
        if( ap->sp->index<lemp->nterminal ) continue;
        if( ap->sp->index==lemp->nsymbol ) continue;
        action = compute_action(lemp, ap);
        if( action<0 ) continue;
        acttab_action(pActtab, ap->sp->index, action);
      }
      stp->iNtOfst = acttab_insert(pActtab, 0);
      if( stp->iNtOfst<mnNtOfst ) mnNtOfst = stp->iNtOfst;
      if( stp->iNtOfst>mxNtOfst ) mxNtOfst = stp->iNtOfst;
    }
#if 0  /* Uncomment for a trace of how the yy_action[] table fills out */
    { int jj, nn;
      for(jj=nn=0; jj<pActtab->nAction; jj++){
        if( pActtab->aAction[jj].action<0 ) nn++;
................................................................................
  **                     shifting terminals.
  **  yy_reduce_ofst[]   For each state, the offset into yy_action for
  **                     shifting non-terminals after a reduce.
  **  yy_default[]       Default action for each state.
  */

  /* Output the yy_action table */
  lemp->nactiontab = n = acttab_action_size(pActtab);
  lemp->tablesize += n*szActionType;
  fprintf(out,"#define YY_ACTTAB_COUNT (%d)\n", n); lineno++;
  fprintf(out,"static const YYACTIONTYPE yy_action[] = {\n"); lineno++;
  for(i=j=0; i<n; i++){
    int action = acttab_yyaction(pActtab, i);
    if( action<0 ) action = lemp->noAction;
    if( j==0 ) fprintf(out," /* %5d */ ", i);
................................................................................
    }else{
      j++;
    }
  }
  fprintf(out, "};\n"); lineno++;

  /* Output the yy_lookahead table */
  lemp->nlookaheadtab = n = acttab_lookahead_size(pActtab);
  lemp->tablesize += n*szCodeType;
  fprintf(out,"static const YYCODETYPE yy_lookahead[] = {\n"); lineno++;
  for(i=j=0; i<n; i++){
    int la = acttab_yylookahead(pActtab, i);
    if( la<0 ) la = lemp->nsymbol;
    if( j==0 ) fprintf(out," /* %5d */ ", i);
    fprintf(out, " %4d,", la);
................................................................................
    }
  }
  fprintf(out, "};\n"); lineno++;

  /* Output the yy_shift_ofst[] table */
  n = lemp->nxstate;
  while( n>0 && lemp->sorted[n-1]->iTknOfst==NO_OFFSET ) n--;

  fprintf(out, "#define YY_SHIFT_COUNT    (%d)\n", n-1); lineno++;
  fprintf(out, "#define YY_SHIFT_MIN      (%d)\n", mnTknOfst); lineno++;
  fprintf(out, "#define YY_SHIFT_MAX      (%d)\n", mxTknOfst); lineno++;
  fprintf(out, "static const %s yy_shift_ofst[] = {\n",
       minimum_size_type(mnTknOfst, lemp->nterminal+lemp->nactiontab, &sz));
       lineno++;
  lemp->tablesize += n*sz;
................................................................................
    }else{
      j++;
    }
  }
  fprintf(out, "};\n"); lineno++;

  /* Output the yy_reduce_ofst[] table */

  n = lemp->nxstate;
  while( n>0 && lemp->sorted[n-1]->iNtOfst==NO_OFFSET ) n--;
  fprintf(out, "#define YY_REDUCE_COUNT (%d)\n", n-1); lineno++;
  fprintf(out, "#define YY_REDUCE_MIN   (%d)\n", mnNtOfst); lineno++;
  fprintf(out, "#define YY_REDUCE_MAX   (%d)\n", mxNtOfst); lineno++;
  fprintf(out, "static const %s yy_reduce_ofst[] = {\n",
          minimum_size_type(mnNtOfst-1, mxNtOfst, &sz)); lineno++;
................................................................................
  }
  tplt_xfer(lemp->name, in, out, &lineno);

  /* Generate a table containing the symbolic name of every symbol
  */
  for(i=0; i<lemp->nsymbol; i++){
    lemon_sprintf(line,"\"%s\",",lemp->symbols[i]->name);
    fprintf(out,"  /* %4d */ \"%s\",\n",i, lemp->symbols[i]->name); lineno++;

  }

  tplt_xfer(lemp->name,in,out,&lineno);

  /* Generate a table containing a text string that describes every
  ** rule in the rule set of the grammar.  This information is used
  ** when tracing REDUCE actions.
  */
  for(i=0, rp=lemp->rule; rp; rp=rp->next, i++){

Changes to tool/lempar.c.

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**
** The action table is constructed as a single large table named yy_action[].
** Given state S and lookahead X, the action is computed as either:
**
**    (A)   N = yy_action[ yy_shift_ofst[S] + X ]
**    (B)   N = yy_default[S]
**
** The (A) formula is preferred.  The B formula is used instead if:
**    (1)  The yy_shift_ofst[S]+X value is out of range, or
**    (2)  yy_lookahead[yy_shift_ofst[S]+X] is not equal to X, or
**    (3)  yy_shift_ofst[S] equal YY_SHIFT_USE_DFLT.
** (Implementation note: YY_SHIFT_USE_DFLT is chosen so that
** YY_SHIFT_USE_DFLT+X will be out of range for all possible lookaheads X.
** Hence only tests (1) and (2) need to be evaluated.)
**
** The formulas above are for computing the action when the lookahead is
** a terminal symbol.  If the lookahead is a non-terminal (as occurs after
** a reduce action) then the yy_reduce_ofst[] array is used in place of
** the yy_shift_ofst[] array and YY_REDUCE_USE_DFLT is used in place of
** YY_SHIFT_USE_DFLT.
**
** The following are the tables generated in this section:
**
**  yy_action[]        A single table containing all actions.
**  yy_lookahead[]     A table containing the lookahead for each entry in
**                     yy_action.  Used to detect hash collisions.
**  yy_shift_ofst[]    For each state, the offset into yy_action for
................................................................................
 
  if( stateno>YY_MAX_SHIFT ) return stateno;
  assert( stateno <= YY_SHIFT_COUNT );
  do{
    i = yy_shift_ofst[stateno];
    assert( iLookAhead!=YYNOCODE );
    i += iLookAhead;

    if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
#ifdef YYFALLBACK
      YYCODETYPE iFallback;            /* Fallback token */
      if( iLookAhead<sizeof(yyFallback)/sizeof(yyFallback[0])
             && (iFallback = yyFallback[iLookAhead])!=0 ){
#ifndef NDEBUG
        if( yyTraceFILE ){
          fprintf(yyTraceFILE, "%sFALLBACK %s => %s\n",
................................................................................
  if( stateno>YY_REDUCE_COUNT ){
    return yy_default[stateno];
  }
#else
  assert( stateno<=YY_REDUCE_COUNT );
#endif
  i = yy_reduce_ofst[stateno];
  assert( i!=YY_REDUCE_USE_DFLT );
  assert( iLookAhead!=YYNOCODE );
  i += iLookAhead;
#ifdef YYERRORSYMBOL
  if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
    return yy_default[stateno];
  }
#else







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**
** The action table is constructed as a single large table named yy_action[].
** Given state S and lookahead X, the action is computed as either:
**
**    (A)   N = yy_action[ yy_shift_ofst[S] + X ]
**    (B)   N = yy_default[S]
**
** The (A) formula is preferred.  The B formula is used instead if

** yy_lookahead[yy_shift_ofst[S]+X] is not equal to X.




**
** The formulas above are for computing the action when the lookahead is
** a terminal symbol.  If the lookahead is a non-terminal (as occurs after
** a reduce action) then the yy_reduce_ofst[] array is used in place of
** the yy_shift_ofst[] array.

**
** The following are the tables generated in this section:
**
**  yy_action[]        A single table containing all actions.
**  yy_lookahead[]     A table containing the lookahead for each entry in
**                     yy_action.  Used to detect hash collisions.
**  yy_shift_ofst[]    For each state, the offset into yy_action for
................................................................................
 
  if( stateno>YY_MAX_SHIFT ) return stateno;
  assert( stateno <= YY_SHIFT_COUNT );
  do{
    i = yy_shift_ofst[stateno];
    assert( iLookAhead!=YYNOCODE );
    i += iLookAhead;
    assert( i>=0 && i<sizeof(yy_lookahead)/sizeof(yy_lookahead[0]) );
    if( yy_lookahead[i]!=iLookAhead ){
#ifdef YYFALLBACK
      YYCODETYPE iFallback;            /* Fallback token */
      if( iLookAhead<sizeof(yyFallback)/sizeof(yyFallback[0])
             && (iFallback = yyFallback[iLookAhead])!=0 ){
#ifndef NDEBUG
        if( yyTraceFILE ){
          fprintf(yyTraceFILE, "%sFALLBACK %s => %s\n",
................................................................................
  if( stateno>YY_REDUCE_COUNT ){
    return yy_default[stateno];
  }
#else
  assert( stateno<=YY_REDUCE_COUNT );
#endif
  i = yy_reduce_ofst[stateno];

  assert( iLookAhead!=YYNOCODE );
  i += iLookAhead;
#ifdef YYERRORSYMBOL
  if( i<0 || i>=YY_ACTTAB_COUNT || yy_lookahead[i]!=iLookAhead ){
    return yy_default[stateno];
  }
#else