--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.api.test/src/com/oracle/truffle/api/test/vm/ImplicitExplicitExportTest.java	Thu Jun 04 08:08:05 2015 +0200
@@ -0,0 +1,189 @@
+/*
+ * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.api.test.vm;
+
+import com.oracle.truffle.api.TruffleLanguage;
+import com.oracle.truffle.api.source.Source;
+import com.oracle.truffle.api.vm.TruffleVM;
+import java.io.IOException;
+import java.io.Reader;
+import java.util.Enumeration;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+import static org.junit.Assert.*;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ImplicitExplicitExportTest {
+    private TruffleVM vm;
+
+    @Before
+    public void initializeVM() {
+        vm = TruffleVM.newVM().build();
+        assertTrue("Found " + L1 + " language", vm.getLanguages().containsKey(L1));
+        assertTrue("Found " + L2 + " language", vm.getLanguages().containsKey(L2));
+        assertTrue("Found " + L3 + " language", vm.getLanguages().containsKey(L3));
+    }
+
+    @Test
+    public void explicitExportFound() throws IOException {
+        // @formatter:off
+        vm.eval(L1,
+            "explicit.ahoj=42"
+        );
+        Object ret = vm.eval(L3,
+            "return=ahoj"
+        );
+        // @formatter:on
+        assertEquals("42", ret);
+    }
+
+    @Test
+    public void implicitExportFound() throws IOException {
+        // @formatter:off
+        vm.eval(L1,
+            "implicit.ahoj=42"
+        );
+        Object ret = vm.eval(L3,
+            "return=ahoj"
+        );
+        // @formatter:on
+        assertEquals("42", ret);
+    }
+
+    @Test
+    public void explicitExportPreferred2() throws IOException {
+        // @formatter:off
+        vm.eval(L1,
+            "implicit.ahoj=42"
+        );
+        vm.eval(L2,
+            "explicit.ahoj=43"
+        );
+        Object ret = vm.eval(L3,
+            "return=ahoj"
+        );
+        // @formatter:on
+        assertEquals("Explicit import from L2 is used", "43", ret);
+        assertEquals("Global symbol is also 43", "43", vm.findGlobalSymbol("ahoj").invoke(null));
+    }
+
+    @Test
+    public void explicitExportPreferred1() throws IOException {
+        // @formatter:off
+        vm.eval(L1,
+            "explicit.ahoj=43"
+        );
+        vm.eval(L2,
+            "implicit.ahoj=42"
+        );
+        Object ret = vm.eval(L3,
+            "return=ahoj"
+        );
+        // @formatter:on
+        assertEquals("Explicit import from L2 is used", "43", ret);
+        assertEquals("Global symbol is also 43", "43", vm.findGlobalSymbol("ahoj").invoke(null));
+    }
+
+    private abstract static class AbstractExportImportLanguage extends TruffleLanguage {
+        protected AbstractExportImportLanguage(Env env) {
+            super(env);
+        }
+
+        private final Map<String, String> explicit = new HashMap<>();
+        private final Map<String, String> implicit = new HashMap<>();
+
+        @Override
+        protected Object eval(Source code) throws IOException {
+            Properties p = new Properties();
+            try (Reader r = code.getReader()) {
+                p.load(r);
+            }
+            Enumeration<Object> en = p.keys();
+            while (en.hasMoreElements()) {
+                Object n = en.nextElement();
+                if (n instanceof String) {
+                    String k = (String) n;
+                    if (k.startsWith("explicit.")) {
+                        explicit.put(k.substring(9), p.getProperty(k));
+                    }
+                    if (k.startsWith("implicit.")) {
+                        implicit.put(k.substring(9), p.getProperty(k));
+                    }
+                    if (k.equals("return")) {
+                        return env().importSymbol(p.getProperty(k));
+                    }
+                }
+            }
+            return null;
+        }
+
+        @Override
+        protected Object findExportedSymbol(String globalName, boolean onlyExplicit) {
+            if (explicit.containsKey(globalName)) {
+                return explicit.get(globalName);
+            }
+            if (!onlyExplicit && implicit.containsKey(globalName)) {
+                return implicit.get(globalName);
+            }
+            return null;
+        }
+
+        @Override
+        protected Object getLanguageGlobal() {
+            return null;
+        }
+
+        @Override
+        protected boolean isObjectOfLanguage(Object object) {
+            return false;
+        }
+    }
+
+    private static final String L1 = "application/x-test-import-export-1";
+    private static final String L2 = "application/x-test-import-export-2";
+    private static final String L3 = "application/x-test-import-export-3";
+
+    @TruffleLanguage.Registration(mimeType = L1, name = "ImportExport1")
+    public static final class ExportImportLanguage1 extends AbstractExportImportLanguage {
+        public ExportImportLanguage1(Env env) {
+            super(env);
+        }
+    }
+
+    @TruffleLanguage.Registration(mimeType = L2, name = "ImportExport2")
+    public static final class ExportImportLanguage2 extends AbstractExportImportLanguage {
+        public ExportImportLanguage2(Env env) {
+            super(env);
+        }
+    }
+
+    @TruffleLanguage.Registration(mimeType = L3, name = "ImportExport3")
+    public static final class ExportImportLanguage3 extends AbstractExportImportLanguage {
+        public ExportImportLanguage3(Env env) {
+            super(env);
+        }
+    }
+
+}