Re: [rfa] PROBLEMS: document 'constructor breakpoint ignored' bug

[Daniel Jacobowitz <drow@mvista.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