[m-rev.] Compiler bug in conjunction with modes

[Volker Wysk]

Hi

I think I found a compiler bug. The following segment:


:- pred with_connection(pred(T, io, io), T, io, io).
:- mode with_connection(pred(out, di, uo) is det,      out, di, uo) is det.
:- mode with_connection(pred(out, di, uo) is cc_multi, out, di, uo) is
cc_multi.

with_connection(Pred, PRes, !IO) :-

    Cleanup =
        (pred(io.ok::out, !.IO1::di, !:IO1::uo) is cc_multi :-
            !:IO1 = !.IO1),

    exception.finally(   % Line 27
        Pred,
        PRes,
        Cleanup,
        _CleanupRes,
        !IO).


... leads to this compiler error:


finally.m:027: In clause for `with_connection((pred(out, di, uo) is det),
out,
finally.m:027:   di, uo)':
finally.m:027:   in call to predicate `exception.finally'/6:
finally.m:027:   mode error: arguments
finally.m:027:   `Pred, PRes, Cleanup, _CleanupRes, STATE_VARIABLE_IO_0,
STATE_VARIABLE_IO'
finally.m:027:   have the following insts:
finally.m:027:     (pred(out, di, uo) is det),
finally.m:027:     free,
finally.m:027:     /* unique */ (pred(out, di, uo) is cc_multi),
finally.m:027:     free,
finally.m:027:     unique,
finally.m:027:     free
finally.m:027:   which does not match any of the modes for predicate
finally.m:027:   `exception.finally'/6.


It says that the inst of the !:IO argument is free. That's wrong, isn't it?
And when you comment out the ":- mode with_connection... is det." line, it
compiles.

I've attached a module with this, which is ready for compilation.

Cheers,
Volker
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