Re: [PATCH 2/2] gdb: fix crash when getting the value of a label symbol

[Tom Tromey <tom@tromey.com>]

>>>>> "Andrew" == Andrew Burgess via Gdb-patches <gdb-patches@sourceware.org> writes:

Andrew>   (gdb) p some_label
Andrew>   No symbol "some_label" in current context.
...
Andrew> This all seems a little strange to me, it feels like asking about a
Andrew> goto label would not be an unreasonable thing for a user to do.

The issue is that that in C, there's no way to refer to a label in an
expression, so we'd need an extension of some kind.  GNU C has the "&&"
address-of-label extension, I suppose we could do that:

(info "(gcc) Labels as Values")

Andrew> The problem is that label symbols are created using the
Andrew> builtin_core_addr type, which is a pure integer type.

Andrew> The fix I propose is to change the type used for the value of the
Andrew> label symbol, instead of using builtin_core_addr type, we could use
Andrew> builtin_func_ptr, after this calling store_typed_address is fine (the
Andrew> call to store_typed_address is done indirectly through
Andrew> value_from_pointer).

In the GNU C extension, a label value uses "void *" as the type.

Unclear to me which is preferable, or if users are even likely to notice
or care if we decide to change it (like, when/if we implement the
extension).

Anyway the patch looks fine to me.

Tom