Reading Stack Trace

01-24-2005

Hi guys,

I'm trying to debug a deployed application (no debug symbols) and what
I got is a stack trace similar to this one. What does the '+' prefixed
number after the method name signify?

[ApplicationException: Hello, World!]
ASP.Default_cs_aspx.Page_Load() +34
System.Web.Util.ArglessEventHandlerDelegateProxy.C allback(Object
sender, EventArgs e)
System.Web.UI.Control.OnLoad(EventArgs e) +67
System.Web.UI.Control.LoadRecursive() +35
System.Web.UI.Page.ProcessRequestMain() +731

Thanks.
/jop

01-24-2005

+ prefix mean location of the exception can be identified
where it originated in the code.

>-----Original Message-----
>Hi guys,
>
>I'm trying to debug a deployed application (no debug
symbols) and what
>I got is a stack trace similar to this one. What does
the '+' prefixed
>number after the method name signify?
>
>[ApplicationException: Hello, World!]
>ASP.Default_cs_aspx.Page_Load() +34
>System.Web.Util.ArglessEventHandlerDelegateProxy. Callback
(Object
>sender, EventArgs e)
>System.Web.UI.Control.OnLoad(EventArgs e) +67
>System.Web.UI.Control.LoadRecursive() +35
>System.Web.UI.Page.ProcessRequestMain() +731
>
>Thanks.
>/jop
>
>.
>

01-24-2005

Thanks for the info, but where exactly is number pointing to? It is not
the line number because the application does not have source/debug info
to get the numbers from. The stack trace in question came from the code
below. What is the link between the number +34 in the above stack trace
to the line throwing the exception.

Is it possible to translate the +numbers into something more useful? I
guess there should be: why display something that we can not use?

<%@ Page language="c#" AutoEventWireup="true"%>
<script runat="server">
void Page_Load()
{
throw new ApplicationException("Hello, World!");
}
</script>
<html>
<body>
<form runat="server"></form>
</body>
</html>

Cheers,
/jop

01-24-2005

Thanks for the info, but where exactly is number pointing to? It is not
a line number because the application does not have source/debug info
to get the numbers from. The stack trace in question came from the code
below. What is the link between the number +34 in the above stack trace
to the line throwing the exception.

Is it possible to translate the +numbers into something more useful? I
guess there should be: why display something that we can not use?

<%@ Page language="c#" AutoEventWireup="true"%>
<script runat="server">
void Page_Load()
{
throw new ApplicationException("Hello, World!");
}
</script>
<html>
<body>
<form runat="server"></form>
</body>
</html>

01-24-2005

Thanks for the info, but where exactly is number pointing to? It is not
the line number because the application does not have source/debug info
to get the numbers from. The stack trace in question came from the code
below. What is the link between the number +34 in the above stack trace
to the line throwing the exception.

Is it possible to translate the +numbers into something more useful? I
guess there should be: why display something that we can not use?

<%@ Page language="c#" AutoEventWireup="true"%>
<script runat="server">
void Page_Load()
{
throw new ApplicationException("Hello, World!");
}
</script>
<html>
<body>
<form runat="server"></form>
</body>
</html>

Cheers,
/jop

01-24-2005

page_load event handle by +34
onload event handle +64
each event has particular event handler which is invoked
by numbers having prefix +

>-----Original Message-----
>Thanks for the info, but where exactly is number pointing
to? It is not
>a line number because the application does not have
source/debug info
>to get the numbers from. The stack trace in question came
from the code
>below. What is the link between the number +34 in the
above stack trace
>to the line throwing the exception.
>
>Is it possible to translate the +numbers into something
more useful? I
>guess there should be: why display something that we can
not use?
>
><%@ Page language="c#" AutoEventWireup="true"%>
><script runat="server">
>void Page_Load()
>{
>throw new ApplicationException("Hello, World!");
>}
></script>
><html>
> <body>
> <form runat="server"></form>
> </body>
></html>
>
>.
>

01-24-2005

I'm sorry but I still don't get it. What does the numbers mean?

For example, if a program with debug info throws an exception, it will
print out a similar stack trace. But instead of a +prefixed number, it
shows the line number where the exception occurred.

However, if the program does not have debug info, it shows the
+prefixed number instead. I would expect that the +prefixed number
would carry the same type of information (i.e. line number). Even if
debug info is not available, it should be something similar, like IL
code offset in the methods, etc...

Any ideas?

01-24-2005

"Jop" wrote:

> Even if debug info is not available, it should be something similar,
> like IL code offset in the methods, etc...

My guess would be that you're right. Without debug info, it's probably
showing an offset in the compiled DLL.

Have you tried ILDASM to see what's inside the Page_Load?

Steven

- - -

01-24-2005

It is, I believe, an offset into the JIT'ed code - that is the native code.
If you have WinDbg you could disassemble the native code for Page_Load and
have a better idea of where the exception occured, but being native it is
sometimes difficult to map back the instruction to a specific line in C#/VB
or even IL. It would be easier to set the project options to "generate debugging
information" and have a line number to work from.

--
Scott
http://www.OdeToCode.com/blogs/scott/

> I'm sorry but I still don't get it. What does the numbers mean?
>
> For example, if a program with debug info throws an exception, it will
> print out a similar stack trace. But instead of a +prefixed number, it
> shows the line number where the exception occurred.
>
> However, if the program does not have debug info, it shows the
> +prefixed number instead. I would expect that the +prefixed number
> would carry the same type of information (i.e. line number). Even if
> debug info is not available, it should be something similar, like IL
> code offset in the methods, etc...
>
> Any ideas?
>

01-24-2005

Actually, yes - it is the byte offset into native code.

I think I'll make a blog entry out of how to track this down later tonight.

--
Scott
http://www.OdeToCode.com/blogs/scott/

> It is, I believe, an offset into the JIT'ed code - that is the native
> code. If you have WinDbg you could disassemble the native code for
> Page_Load and have a better idea of where the exception occured, but
> being native it is sometimes difficult to map back the instruction to
> a specific line in C#/VB or even IL. It would be easier to set the
> project options to "generate debugging information" and have a line
> number to work from.
>
> --
> Scott
> http://www.OdeToCode.com/blogs/scott/
>> I'm sorry but I still don't get it. What does the numbers mean?
>>
>> For example, if a program with debug info throws an exception, it
>> will print out a similar stack trace. But instead of a +prefixed
>> number, it shows the line number where the exception occurred.
>>
>> However, if the program does not have debug info, it shows the
>> +prefixed number instead. I would expect that the +prefixed number
>> would carry the same type of information (i.e. line number). Even if
>> debug info is not available, it should be something similar, like IL
>> code offset in the methods, etc...
>>
>> Any ideas?
>>

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
C/C++ compilers have one stack for local variables and return addresses and then another stack for array allocations on the stack.	Casey Hawthorne	C Programming	3	11-01-2009 08:23 PM
trace.axd and asp.net trace feature IIS only?	Jiho Han	ASP .Net	0	08-22-2006 12:44 PM
No trace messages using Diagnostics.Trace	McGeeky	ASP .Net	0	02-01-2006 02:49 PM
How to redirect output from Diagnostics.Trace to Page.Trace?	Matthias S.	ASP .Net	1	11-30-2005 09:01 AM
Trace: Can anyone suggest a good tool to catch trace messages?	Rukmal Fernando	ASP .Net	4	10-27-2003 09:03 PM