SQLite

  int iRangeReg;       /* First register in temporary register block */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int szOpAlloc;       /* Bytes of memory space allocated for Vdbe.aOp[] */
  int iSelfTab;        /* Table associated with an index on expr, or negative
                       ** of the base register during check-constraint eval */
  int nLabel;          /* The *negative* of the number of labels used */
  int nLabelAlloc;     /* Number of slots in aLabel */
  int *aLabel;         /* Space to hold the labels */
  ExprList *pConstExpr;/* Constant expressions */
  Token constraintName;/* Name of the constraint currently being parsed */
  yDbMask writeMask;   /* Start a write transaction on these databases */
  yDbMask cookieMask;  /* Bitmask of schema verified databases */
  int regRowid;        /* Register holding rowid of CREATE TABLE entry */

#   define COLNAME_N      1      /* Store only the name */
# else
#   define COLNAME_N      2      /* Store the name and decltype */
# endif
#endif

/*
** The following macro converts a label returned by sqlite3VdbeMakeLabel()
** into an index into the Parse.aLabel[] array that contains the resolved

** address of that label.
*/
#define ADDR(X)  (~(X))

/*
** The makefile scans the vdbe.c source file and creates the "opcodes.h"
** header file that defines a number for each opcode used by the VDBE.
*/
#include "opcodes.h"

** the label is resolved to a specific address, the VDBE will scan
** through its operation list and change all values of P2 which match
** the label into the resolved address.
**
** The VDBE knows that a P2 value is a label because labels are
** always negative and P2 values are suppose to be non-negative.
** Hence, a negative P2 value is a label that has yet to be resolved.
** (Later:) This is only true for opcodes that have the OPFLG_JUMP
** property.
**
** Variable usage notes:
**
**     Parse.aLabel[x]     Stores the address that the x-th label resolves
**                         into.  For testing (SQLITE_DEBUG), unresolved
**                         labels stores -1, but that is not required.
**     Parse.nLabelAlloc   Number of slots allocated to Parse.aLabel[]
**     Parse.nLabel        The *negative* of the number of labels that have
**                         been issued.  The negative is stored because
**                         that gives a performance improvement over storing
**                         the equivalent positive value.
*/
int sqlite3VdbeMakeLabel(Parse *pParse){
  return --pParse->nLabel;
}

/*
** Resolve label "x" to be the address of the next instruction to
** be inserted.  The parameter "x" must have been obtained from
** a prior call to sqlite3VdbeMakeLabel().
*/
static SQLITE_NOINLINE void resizeResolveLabel(Parse *p, Vdbe *v, int j){
  int nNewSize = 10 - p->nLabel;
  p->aLabel = sqlite3DbReallocOrFree(p->db, p->aLabel,
                     nNewSize*sizeof(p->aLabel[0]));
  if( p->aLabel==0 ){
    p->nLabelAlloc = 0;
  }else{
#ifdef SQLITE_DEBUG
    int i;
    for(i=p->nLabelAlloc; i<nNewSize; i++) p->aLabel[i] = -1;
#endif
    p->nLabelAlloc = nNewSize;
    p->aLabel[j] = v->nOp;
  }
}
void sqlite3VdbeResolveLabel(Vdbe *v, int x){
  Parse *p = v->pParse;
  int j = ADDR(x);
  assert( v->magic==VDBE_MAGIC_INIT );
  assert( j<-p->nLabel );
  assert( j>=0 );
#ifdef SQLITE_DEBUG
  if( p->db->flags & SQLITE_VdbeAddopTrace ){
    printf("RESOLVE LABEL %d to %d\n", x, v->nOp);
  }
#endif
  if( p->nLabelAlloc + p->nLabel < 0 ){
    resizeResolveLabel(p,v,j);
  }else{
    assert( p->aLabel[j]==(-1) ); /* Labels may only be resolved once */
    p->aLabel[j] = v->nOp;
  }
}

#endif
        default: {
          if( pOp->p2<0 ){
            /* The mkopcodeh.tcl script has so arranged things that the only
            ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to
            ** have non-negative values for P2. */
            assert( (sqlite3OpcodeProperty[pOp->opcode] & OPFLG_JUMP)!=0 );
            assert( ADDR(pOp->p2)<-pParse->nLabel );
            pOp->p2 = aLabel[ADDR(pOp->p2)];
          }
          break;
        }
      }
      /* The mkopcodeh.tcl script has so arranged things that the only
      ** non-jump opcodes less than SQLITE_MX_JUMP_CODE are guaranteed to