Where to find definition for __FUNCTION__ macro

Where to find definition for __FUNCTION__ macro

[Shriek]

Hi
  Where can I find the implementation of the __FUNCTION__ macro, does
it use symbol table look up  or something ... thanks and regards ...

Shrikanth R K

Re: Where to find definition for __FUNCTION__ macro

[Mihai Dontu]

Shriek wrote:
> Hi
>  Where can I find the implementation of the __FUNCTION__ macro, does
> it use symbol table look up  or something ... thanks and regards ...

A.f.a.i.k __FUNCTION__ is a gcc builtin macro. It's not defined as
regular macros.

M.D.


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Re: Where to find definition for __FUNCTION__ macro

[Shriek]

Alright, I might just as well present my problem here... I am trying
to debug some call back handlers which are actualy registered as
function pointers at boot time for a router, now lets say there is  a
central notification framework and looking at the msg-type it calls a
specific handler, so there is some statement like

               ev_msg_handlers[msg->rtsm_type].
So I was thinking if I could get the internals of the __FUNCTION__
macro and if my assumption that it looks it up in system map then I
could possibly attempt to modify it so as to accept the handler
address and return the function name it is entering ... what say ???

On 8/23/06, Vadiraj <vadiraj.cs@gmail.com> wrote:
> __FUNCTION__ is not defined macro part of compiler(GCC).
>
>
> On 8/23/06, Shriek <shriek.007@gmail.com> wrote:
> >
> Hi
>   Where can I find the implementation of the __FUNCTION__ macro, does
> it use symbol table look up  or something ... thanks and regards ...
>
> Shrikanth R K
> -
> To unsubscribe from this list: send the line "unsubscribe
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>
>
>
>
> --
> cheers,
> Vadi

Re: Where to find definition for __FUNCTION__ macro

[Glynn Clements]

Shriek wrote:

> Alright, I might just as well present my problem here... I am trying
> to debug some call back handlers which are actualy registered as
> function pointers at boot time for a router, now lets say there is  a
> central notification framework and looking at the msg-type it calls a
> specific handler, so there is some statement like
> 
>                ev_msg_handlers[msg->rtsm_type].
> So I was thinking if I could get the internals of the __FUNCTION__
> macro and if my assumption that it looks it up in system map then I
> could possibly attempt to modify it so as to accept the handler
> address and return the function name it is entering ... what say ???

__FUNCTION__ won't help you here.

You need to be able to read either the executable's symbol table (for
a dynamically-linked executable) or its debug information (for an
executable with debug info). For a statically-linked executable with
no debug info, it's impossible; the function's names simply don't
exist anywhere at run-time.

I'd suggest looking at the source code for "nm" for details on reading
symbol information.

-- 
Glynn Clements <glynn@gclements.plus.com>

RE: Where to find definition for __FUNCTION__ macro

[Shorty Porty]

My understanding is that __FUNCTION__ is substituted at compile time. So
__FUNCTION__ doesn't run anything, it's just a string, like __FILE__ or
__LINE__.

shorty

-----Original Message-----
From: linux-c-programming-owner@vger.kernel.org
[mailto:linux-c-programming-owner@vger.kernel.org] On Behalf Of Glynn
Clements
Sent: Wednesday, 23 August 2006 9:12 PM


Shriek wrote:

> Alright, I might just as well present my problem here... I am trying
> to debug some call back handlers which are actualy registered as
> function pointers at boot time for a router, now lets say there is  a
> central notification framework and looking at the msg-type it calls a
> specific handler, so there is some statement like
> 
>                ev_msg_handlers[msg->rtsm_type].
> So I was thinking if I could get the internals of the __FUNCTION__
> macro and if my assumption that it looks it up in system map then I
> could possibly attempt to modify it so as to accept the handler
> address and return the function name it is entering ... what say ???

__FUNCTION__ won't help you here.

You need to be able to read either the executable's symbol table (for
a dynamically-linked executable) or its debug information (for an
executable with debug info). For a statically-linked executable with
no debug info, it's impossible; the function's names simply don't
exist anywhere at run-time.

I'd suggest looking at the source code for "nm" for details on reading
symbol information.