SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.228 2005/09/16 02:38:10 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** Return the 'affinity' of the expression pExpr if any.
**

        break;
      }
    }
    if( i>=pParse->nVarExpr ){
      pExpr->iTable = ++pParse->nVar;
      if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
        pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
        sqlite3ReallocOrFree((void**)&pParse->apVarExpr,
                       pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0]) );
      }
      if( !sqlite3_malloc_failed ){
        assert( pParse->apVarExpr!=0 );
        pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
      }
    }

  ** If all of the above are false, then we can run this code just once
  ** save the results, and reuse the same result on subsequent invocations.
  */
  if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->trigStack ){
    int mem = pParse->nMem++;
    sqlite3VdbeAddOp(v, OP_MemLoad, mem, 0);
    testAddr = sqlite3VdbeAddOp(v, OP_If, 0, 0);
    assert( testAddr>0 || sqlite3_malloc_failed );
    sqlite3VdbeAddOp(v, OP_Integer, 1, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, mem, 1);
  }

  switch( pExpr->op ){
    case TK_IN: {
      char affinity;

**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
** @(#) $Id: parse.y,v 1.180 2005/09/16 02:38:10 drh Exp $
*/

// All token codes are small integers with #defines that begin with "TK_"
%token_prefix TK_

// The type of the data attached to each token is Token.  This is also the
// default type for non-terminals.

%type between_op {int}
between_op(A) ::= BETWEEN.     {A = 0;}
between_op(A) ::= NOT BETWEEN. {A = 1;}
expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
  ExprList *pList = sqlite3ExprListAppend(0, X, 0);
  pList = sqlite3ExprListAppend(pList, Y, 0);
  A = sqlite3Expr(TK_BETWEEN, W, 0, 0);
  if( A ){
    A->pList = pList;
  }else{
    sqlite3ExprListDelete(pList);
  } 
  if( N ) A = sqlite3Expr(TK_NOT, A, 0, 0);
  sqlite3ExprSpan(A,&W->span,&Y->span);
}
%ifndef SQLITE_OMIT_SUBQUERY
  %type in_op {int}
  in_op(A) ::= IN.      {A = 0;}
  in_op(A) ::= NOT IN.  {A = 1;}
  expr(A) ::= expr(X) in_op(N) LP exprlist(Y) RP(E). [IN] {
    A = sqlite3Expr(TK_IN, X, 0, 0);
    if( A ){
      A->pList = Y;
    }else{
      sqlite3ExprListDelete(Y);
    }
    if( N ) A = sqlite3Expr(TK_NOT, A, 0, 0);
    sqlite3ExprSpan(A,&X->span,&E);
  }
  expr(A) ::= LP(B) select(X) RP(E). {
    A = sqlite3Expr(TK_SELECT, 0, 0, 0);
    if( A ){
      A->pSelect = X;
    }else{
      sqlite3SelectDelete(X);
    }
    sqlite3ExprSpan(A,&B,&E);
  }
  expr(A) ::= expr(X) in_op(N) LP select(Y) RP(E).  [IN] {
    A = sqlite3Expr(TK_IN, X, 0, 0);
    if( A ){
      A->pSelect = Y;
    }else{
      sqlite3SelectDelete(Y);
    }
    if( N ) A = sqlite3Expr(TK_NOT, A, 0, 0);
    sqlite3ExprSpan(A,&X->span,&E);
  }
  expr(A) ::= expr(X) in_op(N) nm(Y) dbnm(Z). [IN] {
    SrcList *pSrc = sqlite3SrcListAppend(0,&Y,&Z);
    A = sqlite3Expr(TK_IN, X, 0, 0);
    if( A ){
      A->pSelect = sqlite3SelectNew(0,pSrc,0,0,0,0,0,0,0);
    }else{
      sqlite3SrcListDelete(pSrc);
    }
    if( N ) A = sqlite3Expr(TK_NOT, A, 0, 0);
    sqlite3ExprSpan(A,&X->span,Z.z?&Z:&Y);
  }
  expr(A) ::= EXISTS(B) LP select(Y) RP(E). {
    Expr *p = A = sqlite3Expr(TK_EXISTS, 0, 0, 0);
    if( p ){
      p->pSelect = Y;
      sqlite3ExprSpan(p,&B,&E);
    }else{
      sqlite3SelectDelete(Y);
    }
  }
%endif // SQLITE_OMIT_SUBQUERY

/* CASE expressions */
expr(A) ::= CASE(C) case_operand(X) case_exprlist(Y) case_else(Z) END(E). {
  A = sqlite3Expr(TK_CASE, X, Z, 0);
  if( A ){
    A->pList = Y;
  }else{
    sqlite3ExprListDelete(Y);
  }
  sqlite3ExprSpan(A, &C, &E);
}
%type case_exprlist {ExprList*}
%destructor case_exprlist {sqlite3ExprListDelete($$);}
case_exprlist(A) ::= case_exprlist(X) WHEN expr(Y) THEN expr(Z). {
  A = sqlite3ExprListAppend(X, Y, 0);
  A = sqlite3ExprListAppend(A, Z, 0);

      pM->nAlloc = pM->nChar + nNewChar*2 + 1;
      if( pM->zText==pM->zBase ){
        pM->zText = pM->xRealloc(0, pM->nAlloc);
        if( pM->zText && pM->nChar ){
          memcpy(pM->zText, pM->zBase, pM->nChar);
        }
      }else{
        char *zNew;
        zNew = pM->xRealloc(pM->zText, pM->nAlloc);
        if( zNew ){
          pM->zText = zNew;
        }
      }
    }
  }
  if( pM->zText ){
    if( nNewChar>0 ){
      memcpy(&pM->zText[pM->nChar], zNewText, nNewChar);
      pM->nChar += nNewChar;

  if( xRealloc ){
    if( sM.zText==sM.zBase ){
      sM.zText = xRealloc(0, sM.nChar+1);
      if( sM.zText ){
        memcpy(sM.zText, sM.zBase, sM.nChar+1);
      }
    }else if( sM.nAlloc>sM.nChar+10 ){
      char *zNew = xRealloc(sM.zText, sM.nChar+1);
      if( zNew ){
        sM.zText = zNew;
      }
    }
  }
  return sM.zText;
}

/*
** Realloc that is a real function, not a macro.

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.418 2005/09/16 02:38:11 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Many people are failing to set -DNDEBUG=1 when compiling SQLite.
** Setting NDEBUG makes the code smaller and run faster.  So the following

  void sqlite3Free(void*);
  void *sqlite3Realloc(void*,int);
  char *sqlite3StrDup(const char*);
  char *sqlite3StrNDup(const char*, int);
# define sqlite3CheckMemory(a,b)
# define sqlite3MallocX sqlite3Malloc
#endif
void sqlite3ReallocOrFree(void**,int);
void sqlite3FreeX(void*);
void *sqlite3MallocX(int);
char *sqlite3MPrintf(const char*, ...);
char *sqlite3VMPrintf(const char*, va_list);
void sqlite3DebugPrintf(const char*, ...);
void *sqlite3TextToPtr(const char*);
void sqlite3SetString(char **, ...);

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.145 2005/09/16 02:38:11 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

#if SQLITE_MEMDEBUG>2 && defined(__GLIBC__)
#include <execinfo.h>

  if( zNew ){
    memcpy(zNew, z, n);
    zNew[n] = 0;
  }
  return zNew;
}
#endif /* !defined(SQLITE_MEMDEBUG) */

/*
** Reallocate a buffer to a different size.  This is similar to
** sqliteRealloc() except that if the allocation fails the buffer
** is freed.
*/
void sqlite3ReallocOrFree(void **ppBuf, int newSize){
  void *pNew = sqliteRealloc(*ppBuf, newSize);
  if( pNew ){
    *ppBuf = pNew;
  }else{
    sqliteFree(*ppBuf);
  }
}

/*
** Create a string from the 2nd and subsequent arguments (up to the
** first NULL argument), store the string in memory obtained from
** sqliteMalloc() and make the pointer indicated by the 1st argument
** point to that string.  The 1st argument must either be NULL or 
** point to memory obtained from sqliteMalloc().

**
** 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 1.487 2005/09/16 02:38:11 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

  int i = p->contextStackTop++;
  Context *pContext;

  assert( i>=0 );
  /* FIX ME: This should be allocated as part of the vdbe at compile-time */
  if( i>=p->contextStackDepth ){
    p->contextStackDepth = i+1;
    sqlite3ReallocOrFree((void**)&p->contextStack, sizeof(Context)*(i+1));
    if( p->contextStack==0 ) goto no_mem;
  }
  pContext = &p->contextStack[i];
  pContext->lastRowid = db->lastRowid;
  pContext->nChange = p->nChange;
  pContext->sFifo = p->sFifo;
  sqlite3VdbeFifoInit(&p->sFifo);

  struct AuxData *pAuxData;
  VdbeFunc *pVdbeFunc;
  if( iArg<0 ) return;

  pVdbeFunc = pCtx->pVdbeFunc;
  if( !pVdbeFunc || pVdbeFunc->nAux<=iArg ){
    int nMalloc = sizeof(VdbeFunc) + sizeof(struct AuxData)*iArg;
    pVdbeFunc = sqliteRealloc(pVdbeFunc, nMalloc);
    if( !pVdbeFunc ) return;
    pCtx->pVdbeFunc = pVdbeFunc;
    memset(&pVdbeFunc->apAux[pVdbeFunc->nAux], 0, 
             sizeof(struct AuxData)*(iArg+1-pVdbeFunc->nAux));
    pVdbeFunc->nAux = iArg+1;
    pVdbeFunc->pFunc = pCtx->pFunc;
  }

  pAuxData = &pVdbeFunc->apAux[iArg];

/*
** Resize the Vdbe.aOp array so that it contains at least N
** elements. If the Vdbe is in VDBE_MAGIC_RUN state, then
** the Vdbe.aOp array will be sized to contain exactly N 
** elements.
*/
static void resizeOpArray(Vdbe *p, int N){
  int runMode = p->magic==VDBE_MAGIC_RUN;



  if( runMode || p->nOpAlloc<N ){

    VdbeOp *pNew;
    int nNew = N + 100*(!runMode);
    int oldSize = p->nOpAlloc;
    pNew = sqliteRealloc(p->aOp, nNew*sizeof(Op));
    if( pNew ){
      p->nOpAlloc = nNew;
      p->aOp = pNew;
      if( nNew>oldSize ){
        memset(&p->aOp[oldSize], 0, (nNew-oldSize)*sizeof(Op));
      }
    }
  }
}

/*
** Add a new instruction to the list of instructions current in the
** VDBE.  Return the address of the new instruction.

  int i;
  VdbeOp *pOp;

  i = p->nOp;
  p->nOp++;
  assert( p->magic==VDBE_MAGIC_INIT );
  resizeOpArray(p, i+1);
  if( sqlite3_malloc_failed ){
    return 0;
  }
  pOp = &p->aOp[i];
  pOp->opcode = op;
  pOp->p1 = p1;
  pOp->p2 = p2;
  pOp->p3 = 0;

*/
int sqlite3VdbeMakeLabel(Vdbe *p){
  int i;
  i = p->nLabel++;
  assert( p->magic==VDBE_MAGIC_INIT );
  if( i>=p->nLabelAlloc ){
    p->nLabelAlloc = p->nLabelAlloc*2 + 10;
    sqlite3ReallocOrFree((void**)&p->aLabel,
                          p->nLabelAlloc*sizeof(p->aLabel[0]));
  }
  if( p->aLabel ){
    p->aLabel[i] = -1;
  }
  return -1-i;
}

** Add a whole list of operations to the operation stack.  Return the
** address of the first operation added.
*/
int sqlite3VdbeAddOpList(Vdbe *p, int nOp, VdbeOpList const *aOp){
  int addr;
  assert( p->magic==VDBE_MAGIC_INIT );
  resizeOpArray(p, p->nOp + nOp);
  if( sqlite3_malloc_failed ){
    return 0;
  }
  addr = p->nOp;
  if( nOp>0 ){
    int i;
    VdbeOpList const *pIn = aOp;
    for(i=0; i<nOp; i++, pIn++){

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.172 2005/09/16 02:38:11 drh Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)

      }
      pDup = sqlite3Expr(TK_COLUMN, 0, 0, 0);
      if( pDup ){
        pDup->iTable = iCursor;
        pDup->iColumn = iColumn;
      }
      pNew = sqlite3Expr(TK_IN, pDup, 0, 0);
      if( pNew ){
        pNew->pList = pList;
      }else{
        sqlite3ExprListDelete(pList);
      }
      pTerm->pExpr = pNew;
      pTerm->flags |= TERM_DYNAMIC;
      exprAnalyze(pSrc, pMaskSet, pWC, idxTerm);
      pTerm = &pWC->a[idxTerm];
    }
or_not_possible:
    whereClauseClear(&sOr);

    Vdbe *v = pParse->pVdbe;

    sqlite3CodeSubselect(pParse, pX);
    iTab = pX->iTable;
    sqlite3VdbeAddOp(v, OP_Rewind, iTab, brk);
    VdbeComment((v, "# %.*s", pX->span.n, pX->span.z));
    pLevel->nIn++;
    sqlite3ReallocOrFree((void**)&pLevel->aInLoop,
                                 sizeof(pLevel->aInLoop[0])*3*pLevel->nIn);
    aIn = pLevel->aInLoop;
    if( aIn ){
      aIn += pLevel->nIn*3 - 3;
      aIn[0] = OP_Next;
      aIn[1] = iTab;
      aIn[2] = sqlite3VdbeAddOp(v, OP_Column, iTab, 0);
    }else{
      pLevel->nIn = 0;