define-external variables can't be exported

[sjamaan]

This program fails to compile:

(module test (x)
  (import foreign scheme chicken)
  (define-external x int 123))

If you don't wrap it in a module, x doesn't exist if you load the shared object you get from csc -s.

[LemonBoy]

Here's a patch ​patch addressing this problem.

[sjamaan]

Let's try to fix this in 5.1. It's still relevant.

[sjamaan]

Getting ready for 5.1, moving tickets which won't make it in to 5.2.

[felix winkelmann]

You cannot export a foreign variable - it is not a variable that doesn't have normal Scheme semantics, it may be a volatile memory location and any Scheme variable bound to this will be completely detached. Note that the situation for callback-functions is different, the Scheme part can be called externally and refers only internally to the foreign entity (a function in this case).

I recommend to signal an error when a foreign-variable is appearing in an export list.

[felix winkelmann]

A patch has been posted for this, but it is probably not complete. We could also check for names defined by define-constant and define-type as well...

[sjamaan]

Patch has been applied. Should we keep this ticket here or move to 5.3 for the remaining things?

[felix winkelmann]

A patch for detecting all other entities has been submitted to chicken-hackers.