Re: Any support plan to breakpoints of multiple locations?

[Keith Seitz <keiths at redhat dot com>]

Robert Bu 卜勇华 wrote:
> Eg, for C++ constructor, G++ will generate several machine code
> constructors related to the same source code. So if i set a breakpoint
> in the source line within the constructor, such as:

Ah, for C++... Wow, I haven't looked at insight with C++ for a long time
-- I've given up using gdb with C++ altogether. gdb just plain sucks for
C++ debugging.

> I tried Insight 6.7.1, even the console window does not work. I don't
> know wheter GDB 6.7.1 supports breakpoint with multiple locations.

What do you mean when you say the console window doesn't work? The
console window *is* command-line gdb. If you can't do "break
some_overloaded_function" in the console window and have it do exactly
the same thing as doing it at (the same version of) gdb's command line,
then your version of gdb/insight doesn't have the this feature.

Insight's Function Browser was supposed to assist with overloaded
function resolution (amongst other things). Unfortunately, I see that
the Function Browser has developed some bitrot -- it no longer works as
I expected it to. :-(

MULTIPLE breakpoints do not appear to be working, with either templates
or overloaded functions:

GNU gdb 6.8.50.20080303-cvs
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
(gdb) list
9
10      template <class T>
11      T max(T a, T b)
12      {
13              return a > b ? a : b ;
14      }
15
(gdb) info func max
All functions matching regular expression "max":

File aclass.cpp:
int int max<int>(int, int);
long int long max<long>(long, long);
short int short max<short>(short, short);
(gdb) break max
Function "max" not defined.
Make breakpoint pending on future shared library load? (y or [n]) n
(gdb) rbreak max
Breakpoint 9 at 0x80485a0: file aclass.cpp, line 13.
int int max<int>(int, int);
Breakpoint 10 at 0x80485c2: file aclass.cpp, line 13.
long int long max<long>(long, long);
Breakpoint 11 at 0x80485f2: file aclass.cpp, line 13.
short int short max<short>(short, short);
(gdb) i b
Num     Type           Disp Enb Address    What
1       breakpoint     keep y   0x080485a0 in int max<int>(int, int) at
aclass.cpp:13
2       breakpoint     keep y   0x080485c2 in long max<long>(long, long)
                                       at aclass.cpp:13
3       breakpoint     keep y   0x080485f2 in short max<short>(short, short)
                                       at aclass.cpp:13

So you would have to use "rbreak" to set them, and none of the resulting
breakpoints show "MULTIPLE" at all (I presume the manual is either
out-dated or just plain wrong). Alas, templates don't work at all in the
Function Browser.

You should be able to use the console window to do anything you can with
command-line gdb. The Function Browser is apparently very broken right now.

Keith