Re: Symbols/blocks questions

Matt Rice
2009-09-19T14:34:43Z

On Sat, Sep 19, 2009 at 4:52 AM, Vladimir Prus <ghost@cs.msu.su> wrote:
>
> I am trying to port some MI improvement from the Apple GDB,
> and got some questions about symbol/block handling. I'd
> appreciate if somebody comment on it.
>
> 1. Given 'struct block *b', is it true that
>
>    block_for_pc (b.startaddr) == b
>
> ?
>
> 2. Uness I am mistaken, in case of lines inside templates,
> inline functions, and constructors, decode_line_1 returns
> just one sal. (And breakpoint.c explicitly expands thsoe in
> expand_line_sal). In what cases will decode_line_1 actually
> return multiple sals? For overloaded functions? Anything else?
> Would it be sensible, eventually, to make decode_line_1
> return all locations corresponding to file:line?

decode_all_digits: single (break {,+,-}[0-9]+)
decode_objc: multiple via decode_line_2
decode_indirect: single (break *functionptr)
decode_dollar: single (the first break $convenience or break $function found)
decode_compound: multiple via decode_line_2
decode_variable: single, this one i'm less clear on

if passed a symbol which is not a function, it throws an error
'whatever' not found. through symbols which are functions e.g.
break main fall through, and those do not pass an error but return a
single value.

some of these could potentially return a single when ambiguity exist
based on whatever they decide.

e.g. a function
void $foobar() { }
void uhh() {}
set $foobar = &uhh
or something crazy like that that will never happen and could easily
be avoided by the user.

and decode_indirect i would assume uses whatever is in the scope
objc categories are technically not overloaded functions but I think
this is just semantics on the choice of the term overloaded function.

I wouldn't take this as gospel or anything, i could have easily
overlooked something, for instance i have no idea how
Ada hooks into this.