Hello,
With the new ‘-Wunused-toplevel’ the compiler warns about unused
module-local top-level variables [0].
It works well, but has the following limitations:
- Public variables exported with ‘define-public’, ‘export’, or anything
other than the ‘#:export’ option of ‘define-module’ is considered
private, and thus possibly misdiagnosed as unused.
This is because ‘export’ et al. are only evaluated at run-time, not
at compile-time, unlike ‘define-module’. This is something we could
change, though.
- Local variables used only by a macro are incorrectly flagged as
unused. Example:
(define (bar) 'foo)
(define-syntax baz
(syntax-rules () ((_) (bar))))
Here ‘bar’ is incorrectly flagged as unused. This is because the
definition of ‘baz’ expands to ‘(define baz (make-syntax-transformer
...))’ and this code doesn’t contain any literal
‘(toplevel-ref bar)’. Instead, the reference to ‘bar’ is buried in
an opaque syntax object.
Andy: any idea how to work around this?
Thanks,
Ludo’.
[0]
http://git.sv.gnu.org/cgit/guile.git/commit/?id=bcae9a98b0dd82b7be93e90134a01a03b44b4af7
