regression in alien compilation since 1.0.12 (?)

[Nikodemus Siivola]

Reported by Ken Olum to sbcl-devel on Jan 5 2009:

I get the error "The value NIL is not of type SB-KERNEL:CTYPE" when
trying to compile a function that uses the values returned from an
inline function defined by DEFINE-ALIEN-ROUTINE that has a return type
of "void" and an argument of type :OUT. For example compiling this file,

----------------------------------------------------------------------

(declaim (inline store))

(sb-alien:define-alien-routine "store" void
 (result char :out))

(defun do-store ()
 (multiple-value-list (store)))

----------------------------------------------------------------------

will generate the above error.

I am using X86-64. This happens in SBCL 1.0.23 and in 1.0.20, but not
in 1.0.12. It doesn't happen without the INLINE declaration. It
doesn't happen if I change void to int. If I macroexpand the
DEFINE-ALIEN-ROUTINE form, I get this:

(PROGN
 (DECLAIM (FTYPE (FUNCTION NIL (VALUES NULL (ALIEN CHAR) &OPTIONAL)) STORE))
 (DEFUN STORE ()
  (WITH-ALIEN ((STORE (FUNCTION VOID (* CHAR)) :EXTERN "store") (RESULT CHAR))
              (VALUES (ALIEN-FUNCALL STORE (ADDR RESULT)) RESULT))))

If I evaluate only the defun, I don't get the problem. If I evaluate
the DECLAIM as well, then I do, even though the function does in fact
appear to have the given type.

Apart from whenever is causing the compiler problem, I think it would
be better if when the return type is "void" DEFINE-ALIEN-ROUTINE
did not return the extra NIL.

[Nikodemus Siivola (nikodemus)]

In 1.0.24.33 / 1.0.25.