Re: stepping into a shared object

["Ed Harcourt" <shmooga at hotmail dot com>]

Kevin,

Thanks for the prompt reply.

>  1) After the library is dlopen'd, are you able to place a breakpoint
>     in the shared library and continue to the breakpoint?

No, I can't set a breakpoint anywhere in the shared object. I did some 
further experiments and I'm starting to think this may not be a gdb problem 
since I can't step into it in dbx either. But dbx gives me an error message 
that says:

   "cannot find object file corresponding to source f.cpp"

gdb doesn't tell me anything. However, I can step into it in dbx if I build 
my .so with the Sun compiler and not g++.

So maybe its a problem with linking the mix and match of Sun object files 
and g++ object files.  Or maybe I need some other magic switch other than -g 
in on gcc or the linker yet that I haven't yet discovered.

>  2) Are you able to step into other types of shared libraries (i.e,
>     ones that aren't dlopen'd?

Yes. I tried to create a small testcase of a main compiled with Sun's cc and 
a separate .so with g++ and link them. Unfortunately things work fine in 
this case. The example that doesn't work is on quite a large system.

Any other hints on what I might try next?

Ed

>From: Kevin Buettner <kevinb@redhat.com>
>To: "Ed Harcourt" <shmooga@hotmail.com>, gdb@sources.redhat.com
>Subject: Re: stepping into a shared object
>Date: Thu, 16 May 2002 15:47:52 -0700
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>In-Reply-To: "Ed Harcourt" <shmooga@hotmail.com>        "stepping into a 
>shared object" (May 16,  3:22pm)
>References: <F169xw8Zw5V6QcqnWwA00003938@hotmail.com>
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>
>On May 16,  3:22pm, Ed Harcourt wrote:
>
> > I have a main.c compiled using the Solaris C compiler (not C++). Version 
>is
> > Sun WorkShop 6 update 1 C 5.2 2000/09/11.
> >
> > I have C++ objects built using g++ 2.95.2. Everything built with -g. An
> > entry function f is extern "C".
> >
> > I linked the C++ objects and created a mylib.so using the Solaris linker 
>ld.
> >
> > main does a dlopen to get at the mylib.so. I can't step into f from 
>main.
> >
> > Sound familiar? Or should this work?
>
>It should work.
>
>Here are some things to try:
>
>  1) After the library is dlopen'd, are you able to place a breakpoint
>     in the shared library and continue to the breakpoint?
>
>  2) Are you able to step into other types of shared libraries (i.e,
>     ones that aren't dlopen'd?
>
>(This won't directly solve your problem, but knowing the answers might
>help us to figure out what's going wrong.)
>
>Kevin






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