Calling back scheme from C

[divoplade]

Hello guile,

I am having a hard time understanding what I do wrong when trying to
pass a guile function as a C callback (from C).

You should be able to trigger the bug by saving the 3 attached files
and running:

    guix build -L . pkg-with-the-bug

The bug disappears when ignoring the scheme callback, so I suspect it
has something to do with the callback and not further functions:

    guix build -L . pkg-without-the-bug

Does anyone see an error?

You will find the C code under libguile-nettle.c. guile-nettle.c is
just an ad-hoc interpreter with the primitives built in, to run the
test. The test is example-rsa-sign.in: it defines a callback that will
return a bytevector of length its argument, and that bytevector will be
processed to generate an RSA key pair with nettle. The function with-
rsa-generated-key-pair takes the callback plus other arguments and a
function, and it will call that function with the public key and the
private key.

(define (random-with-guile length)
  (use-modules (srfi srfi-1))
  (use-modules (rnrs bytevectors))
  (u8-list->bytevector
   (unfold (lambda (i) (>= i length))
           (lambda (i) (random 256))
           1+
           0)))

(define (generate-rsa-keypair nbits random progress)
  (with-rsa-generated-key-pair random progress nbits 16
    (lambda (public private)
      (rsa-public-key-n public))))

(define keypair
  (generate-rsa-keypair 2048 random-with-guile #f))

(if keypair
    (format #t "The key pair has been generated.\n")
    (begin
      (format (current-error-port)
              "The key pair could not be generated.\n")
      (exit 1)))

Best regards,

divoplade

bugs.scm
Description: Text Data

disable-function-call.patch
Description: Text Data

guile-nettle-0.3.0.8-c2e5.tar.gz
Description: application/compressed-tar