Subj : Re: js engine crashes at NewScopeProperty
To   : netscape.public.mozilla.jseng
From : "Pradip Singh" <pradip.s@ap.sony.com>
Date : Tue Mar 23 2004 12:27 pm

Hi Brendon,

  Thanx for replying so fast. Actually the whole scenario is like this. I am
compiling a script using the function JS_CompileFileHandle(cx, glob,
filename,&fileRef);

It was failing in compilation in the file jsemit.c in function
JSBool
js_SetSrcNoteOffset(JSContext *cx, JSCodeGenerator *cg, uintN index,uintN
which, ptrdiff_t offset)

at point  if ((jsuword)offset >= (jsuword)(((ptrdiff_t)SN_3BYTE_OFFSET_FLAG)
<< 16))

and it gave me the error statement to large. So i changed the value of the
macro SN_3BYTE_OFFSET_FLAG to 0x100.

Now after changing the value to hundred the script started compiling. But it
failed to execute as it was crashing in the function
NewScopeProperty(JSRuntime *rt); As u sugested to Debug more. I debuged and
found that it was crashing at point JS_ARENA_ALLOCATE_CAST(sprop,
JSScopeProperty *,
                               &rt->propertyArenaPool,
                               sizeof(JSScopeProperty));

Inside this macro it was crashing at point _q = _p + _nb;
I feel _p doesnot contain proper value. Its value was comming as 0x0000001
which i think is wrong.

The script is given below

function test1(event)
{
  var target = event.getTarget();
  var x =  event.getXPosition();
  var y =  event.getYPosition();
  var attrList = target.get_attributes();
  var len = attrList.get_length();
  var no = 0;
  for (no = 0;no<len;no++)
  {
    var atts = attrList.item(no);
    var attName = atts.get_nodeName();
    if (attName == "x")
    {
       atts.set_nodeValue(x+20);
    }

   if (attName == "y")
    {
       atts.set_nodeValue(y+20);
    }

  }

But it gets executed onclick event.

Also what is the type of info u want regarding the OS and hardware.

Plz reply.
Thanks in advance.
Pradip


----- Original Message -----
From: "Brendan Eich" <brendan@meer.net>
To: "Pradip Singh" <pradip.s@ap.sony.com>
Sent: Tuesday, March 23, 2004 1:10 AM
Subject: Re: js engine crashes at NewScopeProperty


> Pradip Singh wrote:
>
> > in jsscope.c. It crashes at this point
> > JS_ARENA_ALLOCATE_CAST(sprop, JSScopeProperty *,
> >                                &rt->propertyArenaPool,
> >                                sizeof(JSScopeProperty));
> > Plz help. Any help will be appriciated.
>
> You'll have to debug more.  Where in that macro's expansion does it
> crash?  Expand the macro by hand at that call site and re-test.  And is
> the crash a null pointer, or a misaligned access, or some other kind of
> fault?  More machine- or OS-specific exception information needed.
>
> /be
>
>

.