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From: Tom Tromey <tromey@redhat.com>
To: Sinbad <sinbad.sinbad@gmail.com>
Cc: gdb@sourceware.org
Subject: Re: gdb user defined function
References: <CAOCFqOuvnuD2OjkJ0+b+10J+kt892Ch+uT3CF1miTwCo6ZvChQ@mail.gmail.com>
Date: Mon, 16 Jan 2012 20:46:00 -0000
In-Reply-To: <CAOCFqOuvnuD2OjkJ0+b+10J+kt892Ch+uT3CF1miTwCo6ZvChQ@mail.gmail.com>	(Sinbad's message of "Sun, 15 Jan 2012 08:21:11 +0530")
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>>>>> "Sinbad" == Sinbad  <sinbad.sinbad@gmail.com> writes:

Sinbad> i am trying to write a user-defined function in gdb.
Sinbad> while analyzing the core is it possible to see if a
Sinbad> pointer variable is accessible or not inside a gdb
Sinbad> user-defined function. for example.
Sinbad> (gdb) p *ptr
Sinbad> cannot access memory at address 0x35336
Sinbad> is there any way to find this inside a gdb function.
Sinbad> i need something as follows
Sinbad> define sub
Sinbad>    is_accessible(ptr)
Sinbad> end

I can't think of an easy way to do this from the gdb CLI, but you can do
it from Python by catching the exception.

You could straightforwardly write a $is_valid function that examines a
pointer for validity.

Tom