Re: [PATCH] Print void types correctly in Rust

[Tom Tromey <tom@tromey.com>]

Tom> ... I wonder if that is something that changed after 1.8, or if it's the
Tom> case that the unit type can be represented in multiple ways.  (Or maybe
Tom> this only handles the unit type constructed by rust_language_arch_info?)

[...]

Manish> +// Empty function, should not have "void"
Manish> +// or "()" in its return type
Manish> +fn empty() {

Tom> I'm curious what happens if it does say "-> ()"?

I did the experiment myself and I think I see what's going on now.

For an explicit "()", like "let y = ()", we'll end up with a zero-sized
integer type:

 <1><98>: Abbrev Number: 7 (DW_TAG_base_type)
    <99>   DW_AT_name        : (indirect string, offset: 0x88): ()
    <9d>   DW_AT_encoding    : 7	(unsigned)
    <9e>   DW_AT_byte_size   : 0


However, "fn empty()" (or in my experiment also "fn empty()->()"), the
type is left unspecified in the DWARF, which gdb turns into
TYPE_CODE_VOID (see dwarf2read.c:read_unspecified_type).

I think both have to be handled.  However I think it's fine to do some
cleanup in a follow-up patch, which I'm happy to do.

So your patch is OK with the ChangeLog entry and the indentation fixed.

Tom