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Re: [rfa] PROBLEMS: document 'constructor breakpoint ignored' bug
- From: Daniel Jacobowitz <drow at mvista dot com>
- To: Andrew Cagney <ac131313 at redhat dot com>
- Cc: Michael Elizabeth Chastain <mec at shout dot net>,gdb-patches at sources dot redhat dot com
- Date: Wed, 25 Jun 2003 19:04:48 -0400
- Subject: Re: [rfa] PROBLEMS: document 'constructor breakpoint ignored' bug
- References: <200306242026.h5OKQThr012996@duracef.shout.net> <3EFA0DE4.4070009@redhat.com>
Sure, since it's not going to be fixed in time. Go for it.
On Wed, Jun 25, 2003 at 05:02:28PM -0400, Andrew Cagney wrote:
> It's C++ so Daniel?
>
> Andrew
> Date: Tue, 24 Jun 2003 16:26:29 -0400
> From: Michael Elizabeth Chastain <mec@shout.net>
> Subject: [rfa] PROBLEMS: document 'constructor breakpoint ignored' bug
> To: gdb-patches@sources.redhat.com
>
> This patch documents the notorious "constructor breakpoints ignored"
> problem in the gdb PROBLEMS file.
>
> Okay to apply this to mainline?
>
> Okay to apply this to the 6.0 branch?
>
> Michael C
>
> 2003-06-24 Michael Chastain <mec@shout.net>
>
> * PROBLEMS: Document pr gdb/1091 and pr gdb/1193,
> the "constructor breakpoints ignored" bug.
>
> Index: PROBLEMS
> ===================================================================
> RCS file: /cvs/src/src/gdb/PROBLEMS,v
> retrieving revision 1.15
> diff -c -3 -r1.15 PROBLEMS
> *** PROBLEMS 23 Jun 2003 03:28:13 -0000 1.15
> --- PROBLEMS 24 Jun 2003 20:20:53 -0000
> ***************
> *** 3,6 ****
> --- 3,21 ----
>
> See also: http://www.gnu.org/software/gdb/bugs/
>
> + gdb/1091: Constructor breakpoints ignored
> + gdb/1193: g++ 3.3 creates multiple constructors: gdb 5.3 can't set breakpoints
>
> + When gcc 3.x compiles a C++ constructor or C++ destructor, it generates
> + 2 or 3 different versions of the object code. These versions have
> + unique mangled names (they have to, in order for linking to work), but
> + they have identical source code names, which leads to a great deal of
> + confusion. Specifically, if you set a breakpoint in a constructor or a
> + destructor, gdb will put a breakpoint in one of the versions, but your
> + program may execute the other version. This makes it impossible to set
> + breakpoints reliably in constructors or destructors.
> +
> + gcc 3.x generates these multiple object code functions in order to
> + implement virtual base classes. gcc 2.x generated just one object code
> + function with a hidden parameter, but gcc 3.x conforms to a multi-vendor
> + ABI for C++ which requires multiple object code functions.
>
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer