I have a very strange (at least, to me) behavior of gdb:
when I step through some code, and print the value of a simple int
variable, I get different results, depending on whether I link
one of my libraries or not.
Here is the little sample program:
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
int main( void )
{
unsigned int c = 4;
c = static_cast<unsigned int>( logf( c*c ) );
printf("c=%d\n", c );
return 0;
}
This is how I compile/link it:
/usr/bin/g++ -ansi -DOSG_DEBUG -DOSG_BUILD_DLL -DOSG_WITH_GLUT
-DOSG_WITH_QT -g3 -ggdb3 -Wall -W -D_GNU_SOURCE
-I/usr/local/include/OpenSG -o obj/linux2_gcc_dbg/q.o -c q.cpp
/usr/bin/g++ -g3 -ggdb3 -L/usr/X11R6/lib -L/usr/local/lib/OpenSG
obj/linux2_gcc_dbg/q.o -lOSGBase -lOSGSystem -lglut -lGLU -lGL -lXmu
-lXi -lXt -lX11 -o q
Now, when I step through the program, I get this:
(gdb) b 8
Breakpoint 1 at 0x8048686: file q.cpp, line 8.
(gdb) r
Starting program: /work/vd3/kelvin/Coll/test/q
Breakpoint 1, main () at q.cpp:8
8 unsigned int c = 4;
(gdb) n
9 c = static_cast<unsigned int>( logf( c*c ) );
(gdb) p c
$4 = 4
(gdb) n
10 printf("c=%d\n", c );
(gdb) p c
$5 = 0
(gdb) n
c=0
12 return 0;
The funny thing is, when I omit the libraries OSGBase OSGSystem,
I get the correct behavior ("c=2") even when I step through
the program as above!
This is even more funny, because those libraries are actually
not used in the little example above!
All this happens under RedHat 7.1 with g++ 2.96 and
GNU gdb Red Hat Linux 7.x (5.0rh-15) (MI_OUT).
Any ideas?
Thanks a lot in advance,
Gab.
--
/---------------------------------------------------------------------\
| And what if all of animated nature |
| Be but organic Harps diversely fram'd, |
| That tremble into thought, as o'er them sweeps |
| Plastic and vast, one intellectual breeze, |
| At once the Soul of each, and God of all? (Samuel Taylor Coleridge)|
| |
| [EMAIL PROTECTED] __@/' [EMAIL PROTECTED] |
| web.informatik.uni-bonn.de/~zach __@/' www.gabrielzachmann.org |
\---------------------------------------------------------------------/
_______________________________________________
Bug-gdb mailing list
[EMAIL PROTECTED]
http://mail.gnu.org/mailman/listinfo/bug-gdb
