From 5709a3756c8390d5c18ed26119caecf89fcd129f Mon Sep 17 00:00:00 2001
From: Peter Bex <address@hidden>
Date: Tue, 7 May 2019 21:00:34 +0200
Subject: [PATCH] Fix how define-foreign-type defines its conversion procedures

It used to call "define", but this may not be available in the current
macro environment (or refer to something else than Scheme "define"),
so it was changed in de342aacd5bd18a6533e4eb4e04c2955e0f02959 to use
the ##core#set compiler form instead.  This would cause problems when
define-foreign-type was used inside a module, because later references
to the type would trigger an "undefined export" error, which would
cause the module to be unresolvable.

These procedures are gensymed, so they should not actually be
registered for export, but this restores the old behaviour based on
how "define" works at toplevel.  The compiler form already checks that
it is used at toplevel, so we may safely make the assumption that this
won't expand to an internal define in a lambda.
---
 core.scm                 |  7 +++++++
 tests/compiler-tests.scm | 13 +++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/core.scm b/core.scm
index d9aa8a4c..0f08a002 100644
--- a/core.scm
+++ b/core.scm
@@ -1237,6 +1237,13 @@
 				    (mark-variable ret '##compiler#always-bound)
 				    (hide-variable arg)
 				    (hide-variable ret)
+				    ;; NOTE: Above we already check
+				    ;; we're in toplevel context, so
+				    ;; we can unconditionally register
+				    ;; the export here.
+				    ;; TODO: Remove after fixing #1615
+				    (##sys#register-export arg (##sys#current-module))
+				    (##sys#register-export ret (##sys#current-module))
 				    (walk
 				     `(##core#begin
 					(##core#set! ,arg ,(first conv))
diff --git a/tests/compiler-tests.scm b/tests/compiler-tests.scm
index 6e5c8b27..d4585e37 100644
--- a/tests/compiler-tests.scm
+++ b/tests/compiler-tests.scm
@@ -69,6 +69,19 @@
 (import x)
 (assert (= 1 ((bar 42))))
 
+
+;; Test custom foreign type conversions
+
+(module y (my-add1)
+  (import scheme (chicken base) (chicken foreign))
+
+  (define-foreign-type my-int integer add1 sub1)
+
+  (define my-add1 (foreign-lambda* my-int ((my-int x)) "C_return(x+1);")))
+
+(import y)
+(assert (= 2 (my-add1 1)))
+
 ;;; rev. 14574 (reported by Peter Bex)
 ;
 ; - type specifiers in foreign-lambda in macros are incorrectly renamed
-- 
2.11.0