gdb doesn't understand function pointers

[jdm]

struct Foo {
    dtor: extern "C" fn(),
}

extern "C" fn dtor() {
}

fn main() {
    let foo = Foo { dtor: dtor };
    let foo2 = Some(dtor);
    let foo3 = dtor;
    println!("{:?}", foo);
}

[jdm@rosencrantz tmp]$ gdb dtor
(gdb) break dtor.rs:12
Breakpoint 1 at 0x405068: dtor.rs:12. (2 locations)
(gdb) r
Starting program: /tmp/dtor 
Breakpoint 1, dtor::main () at dtor.rs:12
12      println!("{:?}", foo);
(gdb) p foo
$1 = {
  dtor = <error reading variable>
(gdb) p foo2
$2 = {
  <error reading variable>
(gdb) p foo3
$3 = {void ()} 0x7fffffffdca8
(gdb) 

cc @michaelwoerister

[michaelwoerister]

Thanks for the filing the issue, Josh!

[steveklabnik]

rust-gdb now prints

(gdb) p foo
$1 = Foo = {dtor = {void (void)} 0x7fffffffe088}
(gdb) p foo2
$2 = Some = {{void (void)} 0x7fffffffe080}
(gdb) pfoo3
Undefined command: "pfoo3".  Try "help".
(gdb) p foo3
$3 = {void (void)} 0x7fffffffe078
(gdb) p foo2
$2 = Some = {{void (void)} 0x7fffffffe080}
(gdb) p foo3
$3 = {void (void)} 0x7fffffffe078

So seems good!