Displaying structs

[Daniel Berlin]

Ben Elliston <bje@redhat.com> writes:

Try this patch.

set print follow-pointers to the max depth you want to follow, it defaults to 0.

Then print *ptr, should follow the pointers in the structures up to
that depth.

11        dans=new dan;
(gdb) n
12        dans->next=new dan;
(gdb) p dans
$1 = (dan *) 0x8049760
(gdb) n
13        dans->prev=NULL;
(gdb) p dans
$2 = (dan *) 0x8049760
(gdb) set print follow-pointers 1
(gdb) p dans
$3 = (dan *) 0x8049760
(gdb) p dans[0]
$4 = {next = {next = 0x0, prev = 0x0}, prev = 0x0}          
(gdb) set print pretty on
(gdb) p dans[0]
$5 = {
  next = {
      next = 0x0,
      prev = 0x0
    },
  prev = 0x0
}          

Howzat for ya?
I didn't have it print the type of the pointer it's following, it
seemed like it would just waste space.

Is this useful to people?
Should i clean it up and submit it to gdb-patches?
--Dan

> Often, when debugging, I like to examine pointers to structures.  When
> examining the struct instance that the pointer is addressing, I might use:
> 
> (gdb) print/x *ptr
> 
> If the struct has fields which are further pointers to structs, I have to
> manually follow these pointers:
> 
> (gdb) print/x *ptr->next
> or
> (gdb) print/x *ptr->prev
> 
> Is there a way that GDB can recursively follow these (to some level)?  I am
> guessing that there is enough debugging information for it to know that the
> pointers are to meaningful types.
> 
> Ben