Problem with getting function arguments and the right line number in a backtrace.

[Eelco Chaudron <echaudron at extremenetworks dot com>]

Hi all,

I'm trying to use GDB to analyze a memory / core dump made by a system
running VxWorks in a MIPS environment. I wrote a target that should take
care of this, all memory and register access seems to work, but I do have
some problems with the source integration. I'm using GDB version 5.0 build
20010314.

This is what happens; when I do a "back trace" this is the output:
(vxgdb) bt
#0  0x80625130 in dumpMem () at dump.c:475
...
...

The dump mem function is in dump.c, but it points to the last line of that
function:
(vxgdb) l
470             return (ERROR);
471
472         } while (size == TFTP_SEGSIZE);
473         
474       return (OK);
475     }

Also the argument is not correct (i.e. the variables are not shown). If I do
a print for this function, I do see the right types:

(vxgdb) p dumpMem
$1 = {void (int)} 0x80625104 <dumpMem>

I'm not 100% sure all necessary debug information is in the binary/exec
file. What information is needed to get the right line number of the current
PC, and also is there a tool to check this (objdump etc.)?

Also for the arguments, what debug information is needed? If all the
information is in the files, which places in the source are a good start for
debugging?

I hope some one can help....? 

Thanks,

Eelco

PS: This is the frame info...

(vxgdb) info frame
Stack level 0, frame at 0x83976d58:
 pc = 0x80625130 in dumpMem (dump.c:475); saved pc 0x80669bd0
 called by frame at 0x83976de8
 source language c.
 Arglist at 0x83976d58, args: 
 Locals at 0x83976d58, Previous frame's sp is 0x83976d58
 Saved registers:
  v0 at 0x83976d58, a0 at 0x83976d58, s8 at 0x83976d50, ra at 0x83976d54,
  pc at 0x83976d54