Re: reference environment variables from gdb scripts

[Sheng-Liang Song <ssl@baymicrosystems.com>]

Eli Zaretskii wrote:
>> Date: Fri, 24 Aug 2007 09:37:25 -0700
>> From: Sheng-Liang Song <ssl@baymicrosystems.com>
>>
>> BTW, Is there a gdb script functional document?
>>     
>
> The GDB scripting commands are documented in the GDB user manual.  See
> the node "Sequences".
>   
Hi,

I am looking for a more detail document.
(just like this vim script doc with examples):
  http://vimdoc.sourceforge.net/htmldoc/usr_41.html


What is the different between "." and "->" operator in gdb script? 
(Looks like no difference to me. works the same.)

What operators does gdb 6.6 support?

Is a gdb script grammar like this one:
  http://www.nongnu.org/hcb/

$vec->_M_impl
STL vector does not have the member var _M_impl.
gdb) will report: There is no member or method named _M_impl.

How do I check if $vec has the member _M_impl?

I would like to write a script like this:

if  isMember($vec,_M_impl)
  //do something
else
  //do something else
end


I have some examples that works on gdb.6.6 only.

define adder
  if $argc == 1
    print $arg0
  end
  if $argc == 2
    print $arg0 + $arg1
  end
  if $argc == 3
    print $arg0 + $arg1 + $arg2
  end
end

define p_stl_vector64
  set $vec = ($arg0)
  set $vec_begin = 0
  set $vec_size = $vec->_M_impl->_M_finish - $vec->_M_impl->_M_start
  set $vec_end = $vec_size - 1
  if $argc == 3  
    set $vec_begin = ($arg1)
  end
  if $argc == 3
    set $vec_end  = ($arg2)
  end
  if ($vec_size != 0)
    set $i = 0
    while ($i <= $vec_end)
      printf "Vector Element %d:  ", $i
      p *($vec->_M_impl->_M_start+$i)
      set $i++
    end
  end
end


GNU gdb Red Hat Linux (6.3.0.0-1.132.EL4rh) 
(DOES NOT WORK!)

(gdb) adder 1 2 3
Invalid type combination in equality test.


GNU gdb 6.6  (works)
(gdb) adder 1 2 3
$1 = 6