Resolve #907 - Handle arrays & generics properly

compiler/Eta/DeSugar/DsForeign.hs

@@ -858,14 +858,25 @@ genMethodParam argType argFt
   | isObjectFt argFt = ReferenceParameter $ genClassMethodParam argType argFt
   | otherwise        = PrimitiveParameter $ baseType argFt
 
+fieldTypeToParam :: FieldType -> [TypeParameter TypeVariable] -> ReferenceParameter TypeVariable
+fieldTypeToParam ft params = case ft of
+  ObjectType c  -> GenericReferenceParameter c params []
+  ArrayType ft' -> ArrayReferenceParameter (go ft')
+  _             -> panic "fieldTypeToParam: Not object type"
+  where go ft = case ft of
+          ObjectType c  -> ReferenceParameter $ GenericReferenceParameter c [] []
+          ArrayType ft' -> ReferenceParameter $ ArrayReferenceParameter (go ft')
+          _             -> PrimitiveParameter $ baseType ft
+
 genClassMethodParam :: Type -> FieldType -> ReferenceParameter TypeVariable
 genClassMethodParam argType argFt
   | Just tyVar <- getTyVar_maybe argType
   = VariableReferenceParameter $ sigTyVarText tyVar
   | Just (_, tyArgs)      <- splitTyConApp_maybe argType
   , isObjectFt argFt
-  = GenericReferenceParameter (IClassName (getFtClass argFt)) (map genTypeParam tyArgs) []
-  | otherwise = pprPanic "genClassMethodParam: Not a valid argument." (ppr argType <+> ppr (show argFt))
+  = fieldTypeToParam argFt (map genTypeParam tyArgs)
+  | otherwise = pprPanic "genClassMethodParam: Not a valid argument."
+                  (ppr argType <+> ppr (show argFt))
 
 getArgFt :: ExtendsInfo -> Type -> FieldType
 getArgFt extendsInfo ty

tests/suite/ffi/run/genArrayExport/Main.hs

@@ -0,0 +1,6 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+foreign import java unsafe "@static Utils.test" test :: IO ()
+
+main :: IO ()
+main = test

tests/suite/ffi/run/genArrayExport/Utils.java

@@ -0,0 +1,13 @@
+import test.Hello;
+import java.util.Arrays;
+import java.util.List;
+import java.util.LinkedList;
+
+public class Utils {
+    public static void test() {
+        Hello h = new Hello();
+        List<Integer> l = new LinkedList<Integer>();
+        l.add(1); l.add(2); l.add(3);
+        System.out.println(Arrays.toString(h.hello(l)));
+    }
+}

tests/suite/ffi/run/genArrayExport/export/Export.hs

@@ -0,0 +1,16 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+module Export where
+
+import Java
+
+data Hello = Hello @test.Hello
+  deriving Class
+
+foreign export java "hello" hello :: List JInteger -> Java Hello JByteArray
+
+hello :: List JInteger -> Java Hello JByteArray
+hello list = do
+  let bytes = map fromJava (fromJava list :: [JInteger]) :: [Byte]
+  arr <- anew (length bytes)
+  arr <.> mapM_ (uncurry aset) (zip [0..] bytes)
+  return arr

tests/suite/ffi/run/genArrayExport/export/export.cabal

@@ -0,0 +1,8 @@
+name: export
+version: 1.0
+build-type: Simple
+cabal-version: >= 1.2
+
+library
+    build-depends: base
+    exposed-modules: Export

tests/suite/ffi/run/genArrayExport/genArrayExport.cabal

@@ -0,0 +1,9 @@
+name: genArrayExport
+version: 1.0
+build-type: Simple
+cabal-version: >= 1.2
+
+executable genArrayExport
+    main-is: Main.hs
+    build-depends: base, export
+    java-sources: Utils.java

tests/suite/ffi/run/genArrayExport/genArrayExport.stdout

@@ -0,0 +1 @@
+[1, 2, 3]