DebuggingApplication < DULG

%SECTION0{name=DebuggingApplication}% Application Debugging

%SECTION1{name=DebuggingApplicationLocal}% Local Debugging

In case there is a native GDB available for your target you can use
it for application debugging as usual:

<verbatim>
bash$ gcc -Wall -g -o hello hello.c 
bash$ gdb hello
...
(gdb) l
1       #include <stdio.h>
2
3       int main(int argc, char* argv[])
4       {
5               printf ("Hello world\n");
6               return 0;
7       }
(gdb) break 5
Breakpoint 1 at 0x8048466: file hello.c, line 5.
(gdb) run
Starting program: /opt/eldk/ppc_8xx/tmp/hello

Breakpoint 1, main (argc=0x1, argv=0xbffff9f4) at hello.c:5
5               printf ("Hello world\n");
(gdb) c
Continuing.
Hello world

Program exited normally.
</verbatim>

%SECTION1{name=DebuggingApplicationRemote}% Remote Debugging

=gdbserver= allows you to connect your program with
a remote GDB using the "target remote" command. On the target
machine, you need to have a copy of the program you want to debug.
=gdbserver= does not need your program's symbol
table, so you can strip the program if necessary to save space.
=GDB= on the host system does all the symbol
handling. Here is an example:

<verbatim>
bash$ ${CROSS_COMPILE}gcc -Wall -g -o hello hello.c
bash$ cp -p hello <directory-shared-with-target>/hello-stripped
bash$ ${CROSS_COMPILE}strip <directory-shared-with-target>/hello-stripped
</verbatim>

To use the server, you must tell it how to communicate with =GDB=, the
name of your program, and the arguments for your program. To start a
debugging session via network type on the target:

<verbatim>
bash$ cd <directory-shared-with-host>
bash$ gdbserver 192.168.1.1:12345 hello-stripped
Process hello-stripped created; pid = 353
</verbatim>

And then on the host:

<verbatim>
bash$ ${CROSS_COMPILE}gdb hello
...
(gdb) set solib-absolute-prefix /opt/eldk/$CROSS_COMPILE
(gdb) dir /opt/eldk/$CROSS_COMPILE
Source directories searched:
/opt/eldk/$CROSS_COMPILE:$cdir:$cwd
(gdb) target remote 192.168.1.99:12345
Remote debugging using 192.168.1.99:12345
0x30012748 in ?? ()
...
(gdb) l
1       #include <stdio.h>
2
3       int main(int argc, char* argv[])
4       {
5               printf ("Hello world\n");
6               return 0;
7       }
(gdb) break 5
Breakpoint 1 at 0x10000498: file hello.c, line 5.
(gdb) continue
Continuing.

Breakpoint 1, main (argc=1, argv=0x7ffffbe4) at hello.c:5
5               printf ("Hello world\n");
(gdb) p argc
$1 = 1
(gdb) continue
Continuing.

Program exited normally.
</verbatim>

%X% If the target program you want to debug is linked against shared
libraries, you _must_ tell GDB where the proper target libraries are
located. This is done using the =set solib-absolute-prefix= GDB
command. If this command is omitted, then, apparently, GDB loads the
host versions of the libraries and gets crazy because of that.
10.4. Tips and Tricks		1. Abstract		10.6. Debugging with Graphical User Interfaces
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