Re: problems debugging with clang 3.2, gdb 7.6, libobjc2 SVN, and Ubuntu 13.10

[David Chisnall]

On 7 Oct 2013, at 02:30, Eric Wasylishen <address@hidden> wrote:

> Thanks for the pointers…
> 
> I reconfigured make without enabling the nonfragile ABI (just used "CC=clang 
> ./configure --enable-debug-by-default"), rebuilt everything, and now stepping 
> into Objective-C methods works with gdb, as does ivar printing.
> 
> So do gdb and lldb need some changes to support the nonfragile ABI? If that's 
> the case, maybe we should display a warning when configuring make with 
> --enable-nonfragile-abi, so people know that debugging will be broken.

Yes, the debugger needs to know how to look up the ivar offsets and currently 
gdb doesn't know how to do that.  I'll hopefully add support for our ABI to 
LLDB soon, now that the Linux / FreeBSD ports are in an approximately useable 
state.

If you want to inspect ivars in the debugger currently, you should use the 
runtime's introspection functions rather than ->.

David