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Overview
Comment:Change the PopStack() routine so that it doesn't confuse bounds checkers. Ticket #222. (CVS 825)
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SHA1: fc11fa50b8f39f5e0b3674d7df832ffbca0d948f
User & Date: drh 2003-01-12 17:28:19.000
Context
2003-01-12
17:35
Remove an unused variable from the VDBE. Ticket #223. (CVS 826) (check-in: 0deaf563fd user: drh tags: trunk)
17:28
Change the PopStack() routine so that it doesn't confuse bounds checkers. Ticket #222. (CVS 825) (check-in: fc11fa50b8 user: drh tags: trunk)
2003-01-11
15:02
Remove the aOrder() array from where.c. (CVS 824) (check-in: b2c1edb47f user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/vdbe.c.
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**
** 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 1.195 2003/01/11 13:30:58 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.








|








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**
** 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 1.196 2003/01/12 17:28:19 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.
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}

/*
** Pop the stack N times.  Free any memory associated with the
** popped stack elements.
*/
static void PopStack(Vdbe *p, int N){
  char **pzStack;
  Stack *pStack;
  if( p->zStack==0 ) return;
  pStack = &p->aStack[p->tos];
  pzStack = &p->zStack[p->tos];
  p->tos -= N;
  while( N-- > 0 ){
    if( pStack->flags & STK_Dyn ){
      sqliteFree(*pzStack);
    }
    pStack->flags = 0;
    *pzStack = 0;
    pStack--;
    pzStack--;
  }
}

/*
** Here is a macro to handle the common case of popping the stack
** once.  This macro only works from within the sqliteVdbeExec()
** function.
*/
#define POPSTACK \

 if( aStack[p->tos].flags & STK_Dyn ) sqliteFree(zStack[p->tos]); \
 p->tos--;

/*
** Return TRUE if zNum is a floating-point or integer number.
*/
static int isNumber(const char *zNum){
  if( *zNum=='-' || *zNum=='+' ) zNum++;
  if( !isdigit(*zNum) ) return 0;








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}

/*
** Pop the stack N times.  Free any memory associated with the
** popped stack elements.
*/
static void PopStack(Vdbe *p, int N){
  assert( N>=0 );

  if( p->zStack==0 ) return;
  assert( p->aStack );


  while( N-- > 0 ){
    if( p->aStack[p->tos].flags & STK_Dyn ){
      sqliteFree(p->zStack[p->tos]);
    }
    p->aStack[p->tos].flags = 0;
    p->zStack[p->tos] = 0;
    p->tos--;

  }
}

/*
** Here is a macro to handle the common case of popping the stack
** once.  This macro only works from within the sqliteVdbeExec()
** function.
*/
#define POPSTACK \
  assert(p->tos>=0); \
  if( aStack[p->tos].flags & STK_Dyn ) sqliteFree(zStack[p->tos]); \
  p->tos--;

/*
** Return TRUE if zNum is a floating-point or integer number.
*/
static int isNumber(const char *zNum){
  if( *zNum=='-' || *zNum=='+' ) zNum++;
  if( !isdigit(*zNum) ) return 0;
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  char zBuf[100];             /* Space to sprintf() an integer */
  int returnStack[100];     /* Return address stack for OP_Gosub & OP_Return */
  int returnDepth = 0;      /* Next unused element in returnStack[] */
#ifdef VDBE_PROFILE
  unsigned long long start;
  int origPc;
#endif


  /* No instruction ever pushes more than a single element onto the
  ** 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.








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  char zBuf[100];             /* Space to sprintf() an integer */
  int returnStack[100];     /* Return address stack for OP_Gosub & OP_Return */
  int returnDepth = 0;      /* Next unused element in returnStack[] */
#ifdef VDBE_PROFILE
  unsigned long long start;
  int origPc;
#endif


  /* No instruction ever pushes more than a single element onto the
  ** 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.
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