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 1.341 2008/01/10 03:46:36 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

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

    if( iCol<0 ){
      int iMem = ++pParse->nMem;
      int iAddr;
      Table *pTab = p->pSrc->a[0].pTab;
      int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
      sqlite3VdbeUsesBtree(v, iDb);


      iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
      sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);

      sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
      eType = IN_INDEX_ROWID;

      sqlite3VdbeJumpHere(v, iAddr);
    }else{

          int iAddr;
          char *pKey;
  
          pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
          iDb = sqlite3SchemaToIndex(db, pIdx->pSchema);
          sqlite3VdbeUsesBtree(v, iDb);


          iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
          sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
  
          sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
                               pKey,P4_KEYINFO_HANDOFF);
          VdbeComment((v, "%s", pIdx->zName));
          eType = IN_INDEX_INDEX;
          sqlite3VdbeAddOp2(v, OP_SetNumColumns, iTab, pIdx->nColumn);

  **    *  We are inside a trigger
  **
  ** 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;
    sqlite3VdbeAddOp1(v, OP_If, mem);
    testAddr = sqlite3VdbeAddOp2(v, OP_Integer, 1, mem);
    assert( testAddr>0 || pParse->db->mallocFailed );

  }

  switch( pExpr->op ){
    case TK_IN: {
      char affinity;
      KeyInfo keyInfo;
      int addr;        /* Address of OP_OpenEphemeral instruction */

          Expr *pE2 = pItem->pExpr;

          /* If the expression is not constant then we will need to
          ** disable the test that was generated above that makes sure
          ** this code only executes once.  Because for a non-constant
          ** expression we need to rerun this code each time.
          */
          if( testAddr && !sqlite3ExprIsConstant(pE2) ){
            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
            testAddr = 0;
          }

          /* Evaluate the expression and insert it into the temp table */
          sqlite3ExprCode(pParse, pE2, 0);
          sqlite3VdbeAddOp4(v, OP_MakeRecord, 1, 0, 0, &affinity, 1);
          sqlite3VdbeAddOp1(v, OP_IdxInsert, pExpr->iTable);

      }
      pExpr->iColumn = dest.iParm;
      break;
    }
  }

  if( testAddr ){
    sqlite3VdbeJumpHere(v, testAddr-1);
  }

  return;
}
#endif /* SQLITE_OMIT_SUBQUERY */

/*

      u8 enc = ENC(db);
      CollSeq *pColl = 0;

      zId = (char*)pExpr->token.z;
      nId = pExpr->token.n;
      pDef = sqlite3FindFunction(pParse->db, zId, nId, nExpr, enc, 0);
      assert( pDef!=0 );
      if( pList ){
        nExpr = pList->nExpr;
        sqlite3ExprCodeExprList(pParse, pList, 0);
      }else{
        nExpr = 0;
      }
#ifndef SQLITE_OMIT_VIRTUALTABLE
      /* Possibly overload the function if the first argument is
      ** a virtual table column.
      **
      ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
      ** second argument, not the first, as the argument to test to
      ** see if it is a column in a virtual table.  This is done because

    pExpr->op = TK_REGISTER;
  }
}
#endif

/*
** Generate code that pushes the value of every element of the given
** expression list onto the stack if target==0 or into a sequence of
** registers beginning at target.
**
** Return the number of elements evaluated.
*/
int sqlite3ExprCodeExprList(
  Parse *pParse,     /* Parsing context */
  ExprList *pList,   /* The expression list to be coded */
  int target         /* Where to write results */
){
  struct ExprList_item *pItem;
  int i, n, incr = 1;
  assert( pList!=0 || pParse->db->mallocFailed );
  if( pList==0 ){
    return 0;
  }
  assert( target>=0 );
  n = pList->nExpr;
  if( target==0 ){



    incr = 0;
  }
  for(pItem=pList->a, i=n; i>0; i--, pItem++){
    sqlite3ExprCode(pParse, pItem->pExpr, target);
    target += incr; 
  }
  return n;

  if( pList ){
    for(pItem=pList->a, i=0; nErr==0 && i<pList->nExpr; i++, pItem++){
      nErr += sqlite3ExprAnalyzeAggregates(pNC, pItem->pExpr);
    }
  }
  return nErr;
}

/*
** Allocate or deallocate temporary use registers during code generation.
*/
int sqlite3GetTempReg(Parse *pParse){
  if( pParse->nTempReg ){
    return pParse->aTempReg[--pParse->nTempReg];
  }else{
    return ++pParse->nMem;
  }
}
void sqlite3ReleaseTempReg(Parse *pParse, int iReg){
  if( pParse->nTempReg<sizeof(pParse->aTempReg)/sizeof(pParse->aTempReg[0]) ){
    pParse->aTempReg[pParse->nTempReg++] = iReg;
  }
}

/*
** Allocate or deallocate a block of nReg consecutive registers
*/
int sqlite3GetTempRange(Parse *pParse, int nReg){
  int i;
  if( nReg<=pParse->nRangeReg ){
    i  = pParse->iRangeReg;
    pParse->iRangeReg += nReg;
    pParse->nRangeReg -= nReg;
  }else{
    i = pParse->nMem+1;
    pParse->nMem += nReg;
  }
  return i;
}
void sqlite3ReleaseTempRange(Parse *pParse, int iReg, int nReg){
  if( nReg>pParse->nRangeReg ){
    pParse->nRangeReg = nReg;
    pParse->iRangeReg = iReg;
  }
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.221 2008/01/10 03:46:36 drh Exp $
*/
#include "sqliteInt.h"

/*
** Set P4 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:

    if( overrideError!=OE_Default ){
      onError = overrideError;
    }else if( onError==OE_Default ){
      onError = OE_Abort;
    }
    
    if( isUpdate ){


      j2 = sqlite3VdbeAddOp3(v, OP_Eq, regRowid, 0, regRowid-1);
    }
    j3 = sqlite3VdbeAddOp3(v, OP_NotExists, baseCur, 0, regRowid);
    switch( onError ){
      default: {
        onError = OE_Abort;
        /* Fall thru into the next case */
      }
      case OE_Rollback:
      case OE_Abort:
      case OE_Fail: {
        sqlite3VdbeAddOp4(v, OP_Halt, SQLITE_CONSTRAINT, onError, 0,
                         "PRIMARY KEY must be unique", P4_STATIC);
        break;
      }
      case OE_Replace: {
        sqlite3GenerateRowIndexDelete(v, pTab, baseCur, 0);
        if( isUpdate ){

          sqlite3VdbeAddOp3(v, OP_MoveGe, baseCur, 0, regRowid-hasTwoRowids);
        }
        seenReplace = 1;
        break;
      }
      case OE_Ignore: {
        assert( seenReplace==0 );
        sqlite3VdbeAddOp2(v, OP_Goto, 0, ignoreDest);
        break;
      }
    }
    sqlite3VdbeJumpHere(v, j3);
    if( isUpdate ){
      sqlite3VdbeJumpHere(v, j2);

      sqlite3VdbeAddOp3(v, OP_MoveGe, baseCur, 0, regRowid-1);
    }
  }

  /* Test all UNIQUE constraints by creating entries for each UNIQUE
  ** index and making sure that duplicate entries do not already exist.
  ** Add the new records to the indices as we go.
  */

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.396 2008/01/10 03:46:36 drh Exp $
*/
#include "sqliteInt.h"


/*
** Delete all the content of a Select structure but do not deallocate
** the select structure itself.

*/
static void pushOntoSorter(
  Parse *pParse,         /* Parser context */
  ExprList *pOrderBy,    /* The ORDER BY clause */
  Select *pSelect        /* The whole SELECT statement */
){
  Vdbe *v = pParse->pVdbe;
  int nExpr = pOrderBy->nExpr;
  int regBase = sqlite3GetTempRange(pParse, nExpr+2);
  int regRecord = sqlite3GetTempReg(pParse);
  sqlite3ExprCodeExprList(pParse, pOrderBy, regBase);
  sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr);
  sqlite3VdbeAddOp2(v, OP_Move, 0, regBase+nExpr+1);
  sqlite3VdbeAddOp3(v, OP_RegMakeRec, regBase, nExpr + 2, regRecord);
  sqlite3VdbeAddOp2(v, OP_IdxInsert, pOrderBy->iECursor, regRecord);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3ReleaseTempRange(pParse, regBase, nExpr+2);
  if( pSelect->iLimit>=0 ){
    int addr1, addr2;
    addr1 = sqlite3VdbeAddOp1(v, OP_IfZero, pSelect->iLimit+1);
    sqlite3VdbeAddOp2(v, OP_AddImm, pSelect->iLimit+1, -1);
    addr2 = sqlite3VdbeAddOp0(v, OP_Goto);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3VdbeAddOp1(v, OP_Last, pOrderBy->iECursor);

  for(i=0, pF=pAggInfo->aFunc; i<pAggInfo->nFunc; i++, pF++){
    int nArg;
    int addrNext = 0;
    int regAgg;
    ExprList *pList = pF->pExpr->pList;
    if( pList ){
      nArg = pList->nExpr;
      regAgg = sqlite3GetTempRange(pParse, nArg);
      sqlite3ExprCodeExprList(pParse, pList, regAgg);

    }else{
      nArg = 0;
      regAgg = 0;
    }
    if( pF->iDistinct>=0 ){
      addrNext = sqlite3VdbeMakeLabel(v);
      assert( nArg==1 );

        pColl = pParse->db->pDfltColl;
      }
      sqlite3VdbeAddOp4(v, OP_CollSeq, 0, 0, 0, (char *)pColl, P4_COLLSEQ);
    }
    sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem,
                      (void*)pF->pFunc, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, nArg);
    sqlite3ReleaseTempRange(pParse, regAgg, nArg);
    if( addrNext ){
      sqlite3VdbeResolveLabel(v, addrNext);
    }
  }
  for(i=0, pC=pAggInfo->aCol; i<pAggInfo->nAccumulator; i++, pC++){
    sqlite3ExprCode(pParse, pC->pExpr, pC->iMem);
  }

        groupBySort = 0;
      }else{
        /* Rows are coming out in undetermined order.  We have to push
        ** each row into a sorting index, terminate the first loop,
        ** then loop over the sorting index in order to get the output
        ** in sorted order
        */
        int regBase;
        int regRecord;
        int nCol;
        int nGroupBy;

        groupBySort = 1;
        nGroupBy = pGroupBy->nExpr;
        nCol = nGroupBy + 1;
        j = nGroupBy+1;
        for(i=0; i<sAggInfo.nColumn; i++){
          if( sAggInfo.aCol[i].iSorterColumn>=j ){
            nCol++;
            j++;
          }
        }
        regBase = sqlite3GetTempRange(pParse, nCol);
        sqlite3ExprCodeExprList(pParse, pGroupBy, regBase);
        sqlite3VdbeAddOp2(v, OP_Sequence, sAggInfo.sortingIdx,regBase+nGroupBy);
        j = nGroupBy+1;
        for(i=0; i<sAggInfo.nColumn; i++){
          struct AggInfo_col *pCol = &sAggInfo.aCol[i];
          if( pCol->iSorterColumn>=j ){
            sqlite3ExprCodeGetColumn(v, pCol->pTab, pCol->iColumn, pCol->iTable,
                                     j + regBase);
            j++;
          }
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_RegMakeRec, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_IdxInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);
        sqlite3VdbeAddOp2(v, OP_Sort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
      }

      /* Evaluate the current GROUP BY terms and store in b0, b1, b2...

/*
** 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 1.646 2008/01/10 03:46:36 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** The macro unlikely() is a hint that surrounds a boolean
** expression that is usually false.  Macro likely() surrounds

  char *zErrMsg;       /* An error message */
  Vdbe *pVdbe;         /* An engine for executing database bytecode */
  u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
  u8 nameClash;        /* A permanent table name clashes with temp table name */
  u8 checkSchema;      /* Causes schema cookie check after an error */
  u8 nested;           /* Number of nested calls to the parser/code generator */
  u8 parseError;       /* True after a parsing error.  Ticket #1794 */
  u8 nTempReg;         /* Number of temporary registers in aTempReg[] */
  int aTempReg[8];     /* Holding area for temporary registers */
  int nRangeReg;       /* Size of the temporary register block */
  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 nSet;            /* Number of sets used so far */
  int ckBase;          /* Base register of data during check constraints */
  u32 writeMask;       /* Start a write transaction on these databases */
  u32 cookieMask;      /* Bitmask of schema verified databases */

void sqlite3ErrorMsg(Parse*, const char*, ...);
void sqlite3ErrorClear(Parse*);
void sqlite3Dequote(char*);
void sqlite3DequoteExpr(sqlite3*, Expr*);
int sqlite3KeywordCode(const unsigned char*, int);
int sqlite3RunParser(Parse*, const char*, char **);
void sqlite3FinishCoding(Parse*);
int sqlite3GetTempReg(Parse*);
void sqlite3ReleaseTempReg(Parse*,int);
int sqlite3GetTempRange(Parse*,int);
void sqlite3ReleaseTempRange(Parse*,int,int);
Expr *sqlite3Expr(sqlite3*, int, Expr*, Expr*, const Token*);
Expr *sqlite3PExpr(Parse*, int, Expr*, Expr*, const Token*);
Expr *sqlite3RegisterExpr(Parse*,Token*);
Expr *sqlite3ExprAnd(sqlite3*,Expr*, Expr*);
void sqlite3ExprSpan(Expr*,Token*,Token*);
Expr *sqlite3ExprFunction(Parse*,ExprList*, Token*);
void sqlite3ExprAssignVarNumber(Parse*, Expr*);