SQLite

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** in this file for details.  If in doubt, do not deviate from existing
** commenting and indentation practices when changing or adding code.
**
** $Id: vdbe.c,v 1.184 2002/11/11 00:05:43 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The makefile scans this source file and creates the following
** array of string constants which are the names of all VDBE opcodes.

*/
#define Release(P,I)  if((P)->aStack[I].flags&STK_Dyn){ hardRelease(P,I); }
static void hardRelease(Vdbe *p, int i){
  sqliteFree(p->zStack[i]);
  p->zStack[i] = 0;
  p->aStack[i].flags &= ~(STK_Str|STK_Dyn|STK_Static|STK_Ephem);
}

/*
** Return TRUE if zNum is an integer and write
** the value of the integer into *pNum.
**
** Under Linux (RedHat 7.2) this routine is much faster than atoi()
** for converting strings into integers.
*/
static int toInt(const char *zNum, int *pNum){
  int v = 0;
  int neg;
  if( *zNum=='-' ){
    neg = 1;
    zNum++;
  }else if( *zNum=='+' ){
    neg = 0;
    zNum++;
  }else{
    neg = 0;
  }
  while( isdigit(*zNum) ){
    v = v*10 + *zNum - '0';
    zNum++;
  }
  *pNum = neg ? -v : v;
  return *zNum==0;
}

/*
** Convert the given stack entity into a integer if it isn't one
** already.
**
** Any prior string or real representation is invalidated.  
** NULLs are converted into 0.
*/
#define Integerify(P,I) \
    if(((P)->aStack[(I)].flags&STK_Int)==0){ hardIntegerify(P,I); }
static void hardIntegerify(Vdbe *p, int i){
  if( p->aStack[i].flags & STK_Real ){
    p->aStack[i].i = (int)p->aStack[i].r;
    Release(p, i);
  }else if( p->aStack[i].flags & STK_Str ){
    toInt(p->zStack[i], &p->aStack[i].i);
    Release(p, i);
  }else{
    p->aStack[i].i = 0;
  }
  p->aStack[i].flags = STK_Int;
}

  zNum++;
  if( *zNum=='-' || *zNum=='+' ) zNum++;
  if( !isdigit(*zNum) ) return 0;
  while( isdigit(*zNum) ) zNum++;
  return *zNum==0;
}










/*
** Delete a keylist
*/
static void KeylistFree(Keylist *p){
  while( p ){
    Keylist *pNext = p->pNext;
    sqliteFree(p);

    int i = aStack[tos].r;
    double r = i;
    if( r!=aStack[tos].r ){
      goto mismatch;
    }
    aStack[tos].i = i;
  }else if( aStack[tos].flags & STK_Str ){
    int v;
    if( !toInt(zStack[tos], &v) ){
      goto mismatch;
    }
    p->aStack[tos].i = v;
  }else{
    goto mismatch;
  }
  Release(p, tos);
  p->aStack[tos].flags = STK_Int;
  break;

case OP_Ne:
case OP_Lt:
case OP_Le:
case OP_Gt:
case OP_Ge: {
  int tos = p->tos;
  int nos = tos - 1;
  int c, v;
  int ft, fn;
  VERIFY( if( nos<0 ) goto not_enough_stack; )
  ft = aStack[tos].flags;
  fn = aStack[nos].flags;
  if( (ft | fn) & STK_Null ){
    POPSTACK;
    POPSTACK;
    if( pOp->p2 ){
      if( pOp->p1 ) pc = pOp->p2-1;
    }else{
      p->tos++;
      aStack[nos].flags = STK_Null;
    }
    break;
  }else if( (ft & fn & STK_Int)==STK_Int ){
    c = aStack[nos].i - aStack[tos].i;
  }else if( (ft & STK_Int)!=0 && (fn & STK_Str)!=0 && toInt(zStack[nos],&v) ){
    Release(p, nos);
    aStack[nos].i = v;
    aStack[nos].flags = STK_Int;
    c = aStack[nos].i - aStack[tos].i;
  }else if( (fn & STK_Int)!=0 && (ft & STK_Str)!=0 && toInt(zStack[tos],&v) ){
    Release(p, tos);
    aStack[tos].i = v;
    aStack[tos].flags = STK_Int;
    c = aStack[nos].i - aStack[tos].i;
  }else{
    if( Stringify(p, tos) || Stringify(p, nos) ) goto no_mem;
    c = sqliteCompare(zStack[nos], zStack[tos]);
  }
  switch( pOp->opcode ){
    case OP_Eq:    c = c==0;     break;

  VERIFY( if( iSet<0 || iSet>=p->nSet ) goto bad_instruction; )
  VERIFY( if( NeedStack(p, p->tos) ) goto no_mem; )
  pSet = &p->aSet[iSet];
  nRoot = sqliteHashCount(&pSet->hash);
  aRoot = sqliteMalloc( sizeof(int)*(nRoot+1) );
  for(j=0, i=sqliteHashFirst(&pSet->hash); i; i=sqliteHashNext(i), j++){
    toInt((char*)sqliteHashKey(i), &aRoot[j]);
  }
  aRoot[j] = 0;
  z = sqliteBtreeIntegrityCheck(pOp->p2 ? db->pBeTemp : pBt, aRoot, nRoot);
  if( z==0 || z[0]==0 ){
    if( z ) sqliteFree(z);
    zStack[tos] = "ok";
    aStack[tos].n = 3;