SQLite

  int csChange;     /* Current statement change count (from db->csChange) */
};

/*
** An instance of the virtual machine.  This structure contains the complete
** state of the virtual machine.
**
** The "sqlite_vm" structure pointer that is returned by sqlite3_compile()
** is really a pointer to an instance of this structure.
*/
struct Vdbe {
  sqlite *db;         /* The whole database */
  Vdbe *pPrev,*pNext; /* Linked list of VDBEs with the same Vdbe.db */
  FILE *trace;        /* Write an execution trace here, if not NULL */
  int nOp;            /* Number of instructions in the program */

#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"


/*
** When debugging the code generator in a symbolic debugger, one can
** set the sqlite3_vdbe_addop_trace to 1 and all opcodes will be printed
** as they are added to the instruction stream.
*/
#ifndef NDEBUG
int sqlite3_vdbe_addop_trace = 0;
#endif


/*
** Create a new virtual database engine.
*/
Vdbe *sqlite3VdbeCreate(sqlite *db){

  if( p2<0 && (-1-p2)<p->nLabel && p->aLabel[-1-p2]>=0 ){
    p2 = p->aLabel[-1-p2];
  }
  pOp->p2 = p2;
  pOp->p3 = 0;
  pOp->p3type = P3_NOTUSED;
#ifndef NDEBUG
  if( sqlite3_vdbe_addop_trace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]);
#endif
  return i;
}

/*
** Add an opcode that includes the p3 value.
*/

      VdbeOp *pOut = &p->aOp[i+addr];
      pOut->opcode = pIn->opcode;
      pOut->p1 = pIn->p1;
      pOut->p2 = p2<0 ? addr + ADDR(p2) : p2;
      pOut->p3 = pIn->p3;
      pOut->p3type = pIn->p3 ? P3_STATIC : P3_NOTUSED;
#ifndef NDEBUG
      if( sqlite3_vdbe_addop_trace ){
        sqlite3VdbePrintOp(0, i+addr, &p->aOp[i+addr]);
      }
#endif
    }
    p->nOp += nOp;
  }
  return addr;

  return &p->aOp[addr];
}

/*
** The following group or routines are employed by installable functions
** to return their results.
**
** The sqlite3_set_result_string() routine can be used to return a string
** value or to return a NULL.  To return a NULL, pass in NULL for zResult.
** A copy is made of the string before this routine returns so it is safe
** to pass in an ephemeral string.
**
** sqlite3_set_result_error() works like sqlite3_set_result_string() except
** that it signals a fatal error.  The string argument, if any, is the
** error message.  If the argument is NULL a generic substitute error message
** is used.
**
** The sqlite3_set_result_int() and sqlite3_set_result_double() set the return
** value of the user function to an integer or a double.
**
** These routines are defined here in vdbe.c because they depend on knowing
** the internals of the sqlite_func structure which is only defined in 
** this source file.
*/
char *sqlite3_set_result_string(sqlite_func *p, const char *zResult, int n){
  assert( !p->isStep );
  if( p->s.flags & MEM_Dyn ){
    sqliteFree(p->s.z);
  }
  if( zResult==0 ){
    p->s.flags = MEM_Null;
    n = 0;

      }
      p->s.flags = MEM_Str | MEM_Dyn;
    }
    p->s.n = n+1;
  }
  return p->s.z;
}
void sqlite3_set_result_int(sqlite_func *p, int iResult){
  assert( !p->isStep );
  if( p->s.flags & MEM_Dyn ){
    sqliteFree(p->s.z);
  }
  p->s.i = iResult;
  p->s.flags = MEM_Int;
}
void sqlite3_set_result_double(sqlite_func *p, double rResult){
  assert( !p->isStep );
  if( p->s.flags & MEM_Dyn ){
    sqliteFree(p->s.z);
  }
  p->s.r = rResult;
  p->s.flags = MEM_Real;
}
void sqlite3_set_result_error(sqlite_func *p, const char *zMsg, int n){
  assert( !p->isStep );
  sqlite3_set_result_string(p, zMsg, n);
  p->isError = 1;
}

/*
** Extract the user data from a sqlite_func structure and return a
** pointer to it.
*/
void *sqlite3_user_data(sqlite_func *p){
  assert( p && p->pFunc );
  return p->pFunc->pUserData;
}

/*
** Allocate or return the aggregate context for a user function.  A new
** context is allocated on the first call.  Subsequent calls return the
** same context that was returned on prior calls.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in
** this source file.
*/
void *sqlite3_aggregate_context(sqlite_func *p, int nByte){
  assert( p && p->pFunc && p->pFunc->xStep );
  if( p->pAgg==0 ){
    if( nByte<=NBFS ){
      p->pAgg = (void*)p->s.z;
      memset(p->pAgg, 0, nByte);
    }else{
      p->pAgg = sqliteMalloc( nByte );
    }
  }
  return p->pAgg;
}

/*
** Return the number of times the Step function of a aggregate has been 
** called.
**
** This routine is defined here in vdbe.c because it depends on knowing
** the internals of the sqlite_func structure which is only defined in
** this source file.
*/
int sqlite3_aggregate_count(sqlite_func *p){
  assert( p && p->pFunc && p->pFunc->xStep );
  return p->cnt;
}

#if !defined(NDEBUG) || defined(VDBE_PROFILE)
/*
** Print a single opcode.  This routine is used for debugging only.

    db->flags &= ~SQLITE_Interrupt;
    if( db->magic!=SQLITE_MAGIC_BUSY ){
      p->rc = SQLITE_MISUSE;
    }else{
      p->rc = SQLITE_INTERRUPT;
    }
    rc = SQLITE_ERROR;
    sqlite3SetString(&p->zErrMsg, sqlite3_error_string(p->rc), (char*)0);
  }else{
    sprintf(p->zArgv[0],"%d",i);
    sprintf(p->zArgv[2],"%d", p->aOp[i].p1);
    sprintf(p->zArgv[3],"%d", p->aOp[i].p2);
    if( p->aOp[i].p3type==P3_POINTER ){
      sprintf(p->aStack[4].zShort, "ptr(%#x)", (int)p->aOp[i].p3);
      p->zArgv[4] = p->aStack[4].zShort;

** again.
*/
int sqlite3VdbeReset(Vdbe *p, char **pzErrMsg){
  sqlite *db = p->db;
  int i;

  if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
    sqlite3SetString(pzErrMsg, sqlite3_error_string(SQLITE_MISUSE), (char*)0);
    return SQLITE_MISUSE;
  }
  if( p->zErrMsg ){
    if( pzErrMsg && *pzErrMsg==0 ){
      *pzErrMsg = p->zErrMsg;
    }else{
      sqliteFree(p->zErrMsg);
    }
    p->zErrMsg = 0;
  }else if( p->rc ){
    sqlite3SetString(pzErrMsg, sqlite3_error_string(p->rc), (char*)0);
  }
  Cleanup(p);
  if( p->rc!=SQLITE_OK ){
    switch( p->errorAction ){
      case OE_Abort: {
        if( !p->undoTransOnError ){
          for(i=0; i<db->nDb; i++){

  }
  for(i=0; i<db->nDb; i++){
    if( db->aDb[i].pBt && db->aDb[i].inTrans==2 ){
      sqlite3BtreeCommitStmt(db->aDb[i].pBt);
      db->aDb[i].inTrans = 1;
    }
  }
  assert( p->pTos<&p->aStack[p->pc] || sqlite3_malloc_failed==1 );
#ifdef VDBE_PROFILE
  {
    FILE *out = fopen("vdbe_profile.out", "a");
    if( out ){
      int i;
      fprintf(out, "---- ");
      for(i=0; i<p->nOp; i++){

** the result code.  Write any error message text into *pzErrMsg.
*/
int sqlite3VdbeFinalize(Vdbe *p, char **pzErrMsg){
  int rc;
  sqlite *db;

  if( p->magic!=VDBE_MAGIC_RUN && p->magic!=VDBE_MAGIC_HALT ){
    sqlite3SetString(pzErrMsg, sqlite3_error_string(SQLITE_MISUSE), (char*)0);
    return SQLITE_MISUSE;
  }
  db = p->db;
  rc = sqlite3VdbeReset(p, pzErrMsg);
  sqlite3VdbeDelete(p);
  if( db->want_to_close && db->pVdbe==0 ){
    sqlite3_close(db);
  }
  if( rc==SQLITE_SCHEMA ){
    sqlite3ResetInternalSchema(db, 0);
  }
  return rc;
}

/*
** Set the values of all variables.  Variable $1 in the original SQL will
** be the string azValue[0].  $2 will have the value azValue[1].  And
** so forth.  If a value is out of range (for example $3 when nValue==2)
** then its value will be NULL.
**
** This routine overrides any prior call.
*/
int sqlite3_bind(sqlite_vm *pVm, int i, const char *zVal, int len, int copy){
  Vdbe *p = (Vdbe*)pVm;
  if( p->magic!=VDBE_MAGIC_RUN || p->pc!=0 ){
    return SQLITE_MISUSE;
  }
  if( i<1 || i>p->nVar ){
    return SQLITE_RANGE;
  }

** If a MoveTo operation is pending on the given cursor, then do that
** MoveTo now.  Return an error code.  If no MoveTo is pending, this
** routine does nothing and returns SQLITE_OK.
*/
int sqlite3VdbeCursorMoveto(Cursor *p){
  if( p->deferredMoveto ){
    int res;
    extern int sqlite3_search_count;
    sqlite3BtreeMoveto(p->pCursor, (char*)&p->movetoTarget, sizeof(int), &res);
    p->lastRecno = keyToInt(p->movetoTarget);
    p->recnoIsValid = res==0;
    if( res<0 ){
      sqlite3BtreeNext(p->pCursor, &res);
    }
    sqlite3_search_count++;
    p->deferredMoveto = 0;
  }
  return SQLITE_OK;
}

/*
** FIX ME

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.
**
** $Id: where.c,v 1.91 2004/05/10 10:37:19 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The query generator uses an array of instances of this structure to
** help it analyze the subexpressions of the WHERE clause.  Each WHERE
** clause subexpression is separated from the others by an AND operator.

    return 0;
  }
  
  /* Allocate and initialize the WhereInfo structure that will become the
  ** return value.
  */
  pWInfo = sqliteMalloc( sizeof(WhereInfo) + pTabList->nSrc*sizeof(WhereLevel));
  if( sqlite3_malloc_failed ){
    sqliteFree(pWInfo);
    return 0;
  }
  pWInfo->pParse = pParse;
  pWInfo->pTabList = pTabList;
  pWInfo->peakNTab = pWInfo->savedNTab = pParse->nTab;
  pWInfo->iBreak = sqlite3VdbeMakeLabel(v);