Re: lua debug info

[Andreas Stenius <kaos@...>]

Roberto Ierusalimschy wrote:
> > > Please tell us where are those places so we can correct them.
> >
> > [...]
> > llimits.h
> > lines 44, 46: changed type from int to long, since the comment says it
> > might hold values that won't fit in 16 bits.
>
>
> Actually the comment was wrong :) It is safe to use 16-bit ints there.
Oh, ok :)

> > lobject.c:62
> > integer const larger than 16 bits makes my compiler complain (only warning,
> > so it's no big deal) but it makes me wonder if the calculations may get wrong
>
>
> The only problem is that the test is always false (and the compiler
> is right about the warning). But the algorithm is ok.
Good.

> Now, back to the bug:
Yes!

> > I tried the same example on linux, which gave the expected result:
>
>
> Wich means we need to debug in your machine... Can you help with
> the following tests?
Absolutely.

> do
        local test = {}
        test.__index = test

        function test:foo()
                return self[1]
        end

        function test:func( idx )
                local a, b, c = 1, 2, { foo = idx }
                if idx.foo then return false end
                return self:foo() + idx
        end

        function new_test()
                return setmetatable( { 1, 2, 3, 4, 5 }, test )
        end
end

-- What happens if you write "test.func( self, idx )" instead of the original "test:func( idx )"?
--   same error: attempt to index local `self' (a number value)
--   also tried to call it with t.func(t,3) instead of t:func(3)

-- What happens if you add one or more parameters to the function?
--   function test:func( idx, a, b, c )
--     if b.foo then return false end
--  gives: attempt to index local `self' (a nil value)
--  unless called with a table as arg b, so: t:func(3,_,t) == false (since t.foo == function)

-- What happens if you add one or more local variables to the function?
--   same error again.

> t=new_test()
> =t:func(3)
0: self
1: self
2: self
3: self
4: self
R2RMon: stdin:11: attempt to index local `self' (a number value)
stack traceback:
        stdin:11: in function <stdin:9>
        (tail call): ?
        [C]: ?

What's next?
Too bad I don't have a debugger for my target so I could single step through the code (c-side) as it executes..

//Andreas