Re: remote dwarf info using libunwind

[Tom Tromey <tromey at redhat dot com>]

Alexandre> Adding more stack frames gives it more stack space to sync
Alexandre> up, and then it does display function names correctly, but
Alexandre> it still fails to print file/line numbers.  I'm yet to
Alexandre> figure out why.

I've got some more data for you.

Today I modified my copy of ftrace to add 'pstack' functionality.
(This took about 5 minutes... yay frysk!)  When I compare 'ftrace -s'
to pstack, the results are quite different.  I tried each on a bash
process waiting for command line input.

In particular the frysk-based trace is missing calls at both ends of
the stack (and pstack seems a bit better at finding the function
names, but that part isn't a surprise).

opsy. pstack 26539
#0  0x45bdc402 in __kernel_vsyscall ()
#1  0x45cb3fa3 in __read_nocancel () from /lib/libc.so.6
#2  0x080c152c in rl_getc ()
#3  0x080c1933 in rl_read_key ()
#4  0x080b14d7 in readline_internal_char ()
#5  0x080b1885 in readline ()
#6  0x080642d8 in parse_string_to_word_list ()
#7  0x08060725 in decode_prompt_string ()
#8  0x0806182a in gather_here_documents ()
#9  0x08064856 in yyparse ()
#10 0x0805e67f in parse_command ()
#11 0x0805e733 in read_command ()
#12 0x0805e964 in reader_loop ()
#13 0x0805e397 in main ()

opsy. ./install/bin/fryski -cp /home/tromey/workspace/fdtrace/bin:/home/tromey/gnu/Generics/Gcjh/gcjh.jar frysk.ftrace.Ftrace -s  -p 26539
Stack trace for task {frysk.proc.LinuxTask@6c89c0,pid=26539,tid=26539,state=Attached.WaitForContinueOrUnblock}
  at 0x45bdc402
  at 0x80c1933
  at 0x80b14d7
  at 0x80b1885
  at 0x80642d8
  at 0x8060725
  at 0x806182a
  at 0x8064856
  at 0x805e67f

Tom