value to function?

value to function?

[Andrew Cagney]

Hello,

If the proposal to pass a function value to push_dummy_call is going to 
fly there's going to need to be a method that converts an arbitrary 
value into a function/method value.

Kind of like find_function_addr() and the oposite of value_coerce_function.

Any way, does anyone have a name for such a function, and the code :-)

Andrew

Re: value to function?

[Jim Blandy]

Andrew Cagney <ac131313@redhat.com> writes:
> If the proposal to pass a function value to push_dummy_call is going
> to fly there's going to need to be a method that converts an arbitrary
> value into a function/method value.

A new gdbarch method to be called from where, specifically?  This area
is a mess (just try describing the behavior of find_function_addr...),
so I'm not sure what you mean.

Re: value to function?

[Andrew Cagney]

> Andrew Cagney <ac131313@redhat.com> writes:
> 
>> If the proposal to pass a function value to push_dummy_call is going
>> to fly there's going to need to be a method that converts an arbitrary
>> value into a function/method value.
> 
> 
> A new gdbarch method to be called from where, specifically?  This area
> is a mess (just try describing the behavior of find_function_addr...),
> so I'm not sure what you mean.

Now I think I'm missing something.  What new architecture method?  What 
mess?

> Kind of like find_function_addr() and the oposite of value_coerce_function.

	pre (I guess that value isn't void or NULL);
	struct value *foo (struct value *);
	post (VALUE_TYPE (foo (value)) == TYPE_CODE_FUNC
		|| VALUE_TYPE (foo (value)) == TYPE_CODE_METHOD));

it would be used in relative proximity to push_dummy_call and 
return_value (ex, replace find_function_addr).

Andrew

Re: value to function?

[Jim Blandy]

Andrew Cagney <ac131313@redhat.com> writes:
> > Andrew Cagney <ac131313@redhat.com> writes:
> >
> >> If the proposal to pass a function value to push_dummy_call is going
> >> to fly there's going to need to be a method that converts an arbitrary
> >> value into a function/method value.
> > A new gdbarch method to be called from where, specifically?  This
> > area
> > is a mess (just try describing the behavior of find_function_addr...),
> > so I'm not sure what you mean.
> 
> Now I think I'm missing something.  What new architecture method?
> What mess?

Never mind.  You said "there's going to need to be a method that
converts..."  Since you said "method", I assumed you didn't mean
"function", so I was trying to figure out what sort of method you
meant.

> > Kind of like find_function_addr() and the oposite of value_coerce_function.
> 
> 	pre (I guess that value isn't void or NULL);
> 	struct value *foo (struct value *);
> 	post (VALUE_TYPE (foo (value)) == TYPE_CODE_FUNC
> 		|| VALUE_TYPE (foo (value)) == TYPE_CODE_METHOD));
> 
> it would be used in relative proximity to push_dummy_call and
> return_value (ex, replace find_function_addr).

Sure, this is just a nicer packaging of find_function_addr, which
seems to be doing two separable jobs:

- coercing various non-function values into callable things, and 

- extracting that callable thing's entry point address and return
  type.

A function value carries both those data in a handy and obvious way.