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 1.193 2003/01/07 13:43:46 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.

  int nOp;            /* Number of instructions in the program */
  int nOpAlloc;       /* Number of slots allocated for aOp[] */
  Op *aOp;            /* Space to hold the virtual machine's program */
  int nLabel;         /* Number of labels used */
  int nLabelAlloc;    /* Number of slots allocated in aLabel[] */
  int *aLabel;        /* Space to hold the labels */
  int tos;            /* Index of top of stack */
  int nStackAlloc;    /* Size of the stack */
  Stack *aStack;      /* The operand stack, except string values */
  char **zStack;      /* Text or binary values of the stack */
  char **azColName;   /* Becomes the 4th parameter to callbacks */
  int nCursor;        /* Number of slots in aCsr[] */
  Cursor *aCsr;       /* One element of this array for each open cursor */
  Keylist *pList;     /* A list of ROWIDs */
  Sorter *pSort;      /* A linked list of objects to be sorted */

**
** This routine will automatically close any cursors, lists, and/or
** sorters that were left open.
*/
static void Cleanup(Vdbe *p){
  int i;
  PopStack(p, p->tos+1);
  sqliteFree(p->azColName);
  p->azColName = 0;
  closeAllCursors(p);
  if( p->aMem ){
    for(i=0; i<p->nMem; i++){
      if( p->aMem[i].s.flags & STK_Dyn ){
        sqliteFree(p->aMem[i].z);
      }
    }

    if( p->aOp[i].p3type==P3_DYNAMIC ){
      sqliteFree(p->aOp[i].p3);
    }
  }
  sqliteFree(p->aOp);
  sqliteFree(p->aLabel);
  sqliteFree(p->aStack);
  sqliteFree(p->zStack);
  sqliteFree(p);
}

/*
** Give a listing of the program in the virtual machine.
**
** The interface is the same as sqliteVdbeExec().  But instead of

  ** stack.  And the stack never grows on successive executions of the
  ** same loop.  So the total number of instructions is an upper bound
  ** on the maximum stack depth required.
  **
  ** Allocation all the stack space we will ever need.
  */
  sqliteVdbeAddOp(p, OP_Halt, 0, 0);
  zStack = p->zStack = sqliteMalloc( p->nOp*sizeof(zStack[0]) );
  aStack = p->aStack = sqliteMalloc( p->nOp*sizeof(aStack[0]) );


  p->tos = -1;
#ifdef VDBE_PROFILE
  {
    int i;
    for(i=0; i<p->nOp; i++){
      p->aOp[i].cnt = 0;
      p->aOp[i].cycles = 0;

  p->tos--;
  break;
}

/* Opcode: ColumnCount P1 * *
**
** Specify the number of column values that will appear in the
** array passed as the 4th parameter to the callback.  No checking
** is done.  If this value is wrong, a coredump can result.
*/
case OP_ColumnCount: {
  char **az = sqliteRealloc(p->azColName, (pOp->p1+1)*sizeof(char*));
  if( az==0 ){ goto no_mem; }
  p->azColName = az;
  p->azColName[pOp->p1] = 0;
  p->nCallback = 0;
  break;
}

/* Opcode: ColumnName P1 * P3
**
** P3 becomes the P1-th column name (first is 0).  An array of pointers
** to all column names is passed as the 4th parameter to the callback.
** The ColumnCount opcode must be executed first to allocate space to
** hold the column names.  Failure to do this will likely result in
** a coredump.
*/
case OP_ColumnName: {
  p->azColName[pOp->p1] = pOp->p3;
  p->nCallback = 0;
  break;
}