Re: gdb 6.x 'next' does not work on mips-linux/mipsel-linux

John Van Horne
2005-04-22T22:39:16Z

I just posted a note on PR 1716 about my experience with this problem. Basically,
"next" on a dynamically linked library function fails for me using gdb 6.2.1, 6.3
and 6.3.50.20050420. I saw the previous posts in this thread that made it sound as
though this was fixed in the 20050104 snapshot. However I couldn't find that snapshot,
and the latest failed for me.

I've got gdb configured for mips-linux-gnu, and I'm using gcc-3.3.4 and binutils-2.15.
As a test I'm using testsuite/gdb.base/call-strs.exp. Version 6.3.50.20050420 fails
on the "next" at line 73 (strcpy) with this message:

warning: GDB can't find the start of the function at 0x400cf0.

GDB is unable to find the start of the function at 0x400cf0
and thus can't determine the size of that function's stack frame.
This means that GDB may be unable to access that stack frame, or
the frames below it.
This problem is most likely caused by an invalid program counter or
stack pointer.
However, if you think GDB should simply search farther back
from 0x400cf0 for code which looks like the beginning of a
function, you can increase the range of the search using the `set
heuristic-fence-post' command.
warning: GDB can't find the start of the function at 0x400cf0.
?? ()

The failure occurs both with native and remote debugging.
There's no failure when I "step" into "strcpy" and then finish it.

I'd be happy to provide any more information and would like to know if anyone's
working on this.

Thanks,
-John Van Horne
(not on mailing list, please cc jvh@tivo.com)