# HG changeset patch
# User Jaroslav Tulach <jaroslav.tulach@apidesign.org>
# Date 1370880758 -7200
# Node ID ebedd84fba806a40673c2385f68336f19fbe7d07
# Parent  c19ac78b940e4a75b248c5ae96d121644c46a7a4
Initial version of ClassLoader that understands @JavaScriptBody

diff -r c19ac78b940e -r ebedd84fba80 launcher/fx/pom.xml
--- a/launcher/fx/pom.xml	Sat Jun 08 12:09:10 2013 +0200
+++ b/launcher/fx/pom.xml	Mon Jun 10 18:12:38 2013 +0200
@@ -64,5 +64,16 @@
       <artifactId>org-netbeans-bootstrap</artifactId>
       <version>RELEASE73</version>
     </dependency>
+    <dependency>
+      <groupId>${project.groupId}</groupId>
+      <artifactId>core</artifactId>
+      <version>${project.version}</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.ow2.asm</groupId>
+      <artifactId>asm</artifactId>
+      <version>4.1</version>
+    </dependency>
   </dependencies>
 </project>
diff -r c19ac78b940e -r ebedd84fba80 launcher/fx/src/main/java/org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/launcher/fx/src/main/java/org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader.java	Mon Jun 10 18:12:38 2013 +0200
@@ -0,0 +1,228 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.bck2brwsr.launcher.fximpl;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import org.objectweb.asm.AnnotationVisitor;
+import org.objectweb.asm.ClassReader;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.ClassWriter;
+import org.objectweb.asm.Label;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+import org.objectweb.asm.Type;
+
+/** 
+ *
+ * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ */
+public abstract class JsClassLoader extends URLClassLoader {
+    JsClassLoader(URL[] urls, ClassLoader parent) {
+        super(urls, parent);
+    }
+
+    @Override
+    protected Class<?> findClass(String name) throws ClassNotFoundException {
+        URL u = findResource(name.replace('.', '/') + ".class");
+        if (u != null) {
+            InputStream is = null;
+            try {
+                is = u.openStream();
+                ClassReader cr = new ClassReader(is);
+                ClassWriter w = new ClassWriter(cr, ClassWriter.COMPUTE_MAXS | ClassWriter.COMPUTE_FRAMES);
+                FindInClass fic = new FindInClass(w);
+                cr.accept(fic, 0);
+                byte[] arr = w.toByteArray();
+                return defineClass(name, arr, 0, arr.length);
+            } catch (IOException ex) {
+                throw new ClassNotFoundException("Can't load " + name, ex);
+            } finally {
+                try {
+                    if (is != null) is.close();
+                } catch (IOException ex) {
+                    throw new ClassNotFoundException(null, ex);
+                }
+            }
+        }
+        if (name.startsWith("org.apidesign.bck2brwsr.launcher.fximpl.JsClassLoader")) {
+            return Class.forName(name);
+        }
+        
+        return super.findClass(name);
+    }
+    
+    public final Fn define(String code, String... names) {
+        return defineFn(code, names);
+    }
+    
+
+    protected abstract Fn defineFn(String code, String... names);
+    
+    public static abstract class Fn {
+        public abstract Object invoke(Object... args) throws Exception;
+    }
+    
+    
+    private static final class FindInClass extends ClassVisitor {
+        private String name;
+        
+        public FindInClass(ClassVisitor cv) {
+            super(Opcodes.ASM4, cv);
+        }
+
+        @Override
+        public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+            this.name = name;
+            super.visit(version, access, name, signature, superName, interfaces);
+        }
+        
+        
+
+        @Override
+        public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
+            return new FindInMethod(name,
+                super.visitMethod(access, name, desc, signature, exceptions)
+            );
+        }
+        
+        private final class FindInMethod extends MethodVisitor {
+            private final String name;
+            private List<String> args;
+            private String body;
+            
+            public FindInMethod(String name, MethodVisitor mv) {
+                super(Opcodes.ASM4, mv);
+                this.name = name;
+            }
+
+            @Override
+            public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
+                if ("Lorg/apidesign/bck2brwsr/core/JavaScriptBody;".equals(desc)) { // NOI18N
+                    return new FindInAnno();
+                }
+                return super.visitAnnotation(desc, visible);
+            }
+
+            private void generateJSBody(List<String> args, String body) {
+                this.args = args;
+                this.body = body;
+            }
+            
+            @Override
+            public void visitCode() {
+                if (body == null) {
+                    return;
+                } 
+                
+                super.visitFieldInsn(
+                    Opcodes.GETSTATIC, FindInClass.this.name, 
+                    "$$bck2brwsr$$" + name, 
+                    "Lorg/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader$Fn;"
+                );
+                super.visitInsn(Opcodes.DUP);
+                Label ifNotNull = new Label();
+                super.visitJumpInsn(Opcodes.IFNONNULL, ifNotNull);
+                
+                // init Fn
+                super.visitInsn(Opcodes.POP);
+                super.visitLdcInsn(Type.getObjectType(FindInClass.this.name));
+                super.visitMethodInsn(Opcodes.INVOKEVIRTUAL, 
+                    "java/lang/Class", "getClassLoader", "()Ljava/lang/ClassLoader;"
+                );
+                super.visitTypeInsn(Opcodes.CHECKCAST, "org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader");
+                super.visitLdcInsn(body);
+                super.visitIntInsn(Opcodes.SIPUSH, args.size());
+                super.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/String");
+                for (int i = 0; i < args.size(); i++) {
+                    String name = args.get(i);
+                    super.visitInsn(Opcodes.DUP);
+                    super.visitIntInsn(Opcodes.BIPUSH, i);
+                    super.visitLdcInsn(name);
+                    super.visitInsn(Opcodes.AASTORE);
+                }
+                super.visitMethodInsn(Opcodes.INVOKEVIRTUAL, 
+                    "org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader",
+                    "define", "(Ljava/lang/String;[Ljava/lang/String;)Lorg/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader$Fn;"
+                );
+                // end of Fn init
+                
+                super.visitLabel(ifNotNull);
+                super.visitIntInsn(Opcodes.SIPUSH, args.size());
+                super.visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/Object");
+                super.visitMethodInsn(Opcodes.INVOKEVIRTUAL, 
+                    "org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader$Fn", "invoke", "([Ljava/lang/Object;)Ljava/lang/Object;"
+                );
+                super.visitInsn(Opcodes.ARETURN);
+            }
+
+            @Override
+            public void visitEnd() {
+                super.visitEnd();
+                if (body != null) {
+                    FindInClass.this.visitField(
+                        Opcodes.ACC_PRIVATE | Opcodes.ACC_STATIC, 
+                        "$$bck2brwsr$$" + name, 
+                        "Lorg/apidesign/bck2brwsr/launcher/fximpl/JsClassLoader$Fn;", 
+                        null, null
+                    );
+                }
+            }
+            
+            
+            
+            
+        
+            private final class FindInAnno extends AnnotationVisitor {
+                private List<String> args = new ArrayList<String>();
+                private String body;
+
+                public FindInAnno() {
+                    super(Opcodes.ASM4);
+                }
+
+                @Override
+                public void visit(String name, Object value) {
+                    if (name == null) {
+                        args.add((String) value);
+                        return;
+                    }
+                    assert name.equals("body");
+                    body = (String) value;
+                }
+
+                @Override
+                public AnnotationVisitor visitArray(String name) {
+                    return this;
+                }
+
+                @Override
+                public void visitEnd() {
+                    if (body != null) {
+                        generateJSBody(args, body);
+                    }
+                }
+            }
+        }
+    }
+}
diff -r c19ac78b940e -r ebedd84fba80 launcher/fx/src/test/java/org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoaderTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/launcher/fx/src/test/java/org/apidesign/bck2brwsr/launcher/fximpl/JsClassLoaderTest.java	Mon Jun 10 18:12:38 2013 +0200
@@ -0,0 +1,106 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.bck2brwsr.launcher.fximpl;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.net.URL;
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+import static org.testng.Assert.*;
+import org.testng.annotations.BeforeClass;
+import org.testng.annotations.Test;
+
+/**
+ *
+ * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ */
+public class JsClassLoaderTest {
+    private static ClassLoader loader;
+    private static Class<?> methodClass;
+    
+    public JsClassLoaderTest() {
+    }
+
+    @BeforeClass
+    public static void setUpClass() throws Exception {
+        ScriptEngineManager sem = new ScriptEngineManager();
+        final ScriptEngine eng = sem.getEngineByMimeType("text/javascript");
+        
+        URL my = JsClassLoaderTest.class.getProtectionDomain().getCodeSource().getLocation();
+        ClassLoader parent = JsClassLoaderTest.class.getClassLoader().getParent();
+        loader = new JsClassLoader(new URL[] { my }, parent) {
+            @Override
+            protected JsClassLoader.Fn defineFn(String code, String... names) {
+                StringBuilder sb = new StringBuilder();
+                sb.append("(function() {");
+                sb.append("var r = {};");
+                sb.append("r.fn = function(");
+                String sep = "";
+                for (String n : names) {
+                    sb.append(sep);
+                    sb.append(n);
+                    sep = ", ";
+                }
+                sb.append(") {");
+                sb.append(code);
+                sb.append("};");
+                sb.append("return r;");
+                sb.append("})()");
+                try {
+                    final Object val = eng.eval(sb.toString());
+                    return new JsClassLoader.Fn() {
+                        @Override
+                        public Object invoke(Object... args) throws Exception {
+                            Invocable inv = (Invocable)eng;
+                            return inv.invokeMethod(val, "fn", args);
+                        }
+                    };
+                } catch (ScriptException ex) {
+                    throw new LinkageError("Can't parse: " + sb, ex);
+                }
+            }
+        };
+        
+        methodClass = loader.loadClass(JsMethods.class.getName());
+    }
+    
+    @Test public void noParamMethod() throws Throwable {
+        Method plus = methodClass.getMethod("fortyTwo");
+        try {
+            final Object val = plus.invoke(null);
+            assertTrue(val instanceof Number, "A number returned " + val);
+            assertEquals(((Number)val).intValue(), 42);
+        } catch (InvocationTargetException ex) {
+            throw ex.getTargetException();
+        }
+    }
+    /*
+    @Test public void testExecuteScript() throws Throwable {
+        Method plus = methodClass.getMethod("plus", int.class, int.class);
+        try {
+            assertEquals(plus.invoke(null, 10, 20), 30);
+        } catch (InvocationTargetException ex) {
+            throw ex.getTargetException();
+        }
+    }
+    */
+
+}
\ No newline at end of file
diff -r c19ac78b940e -r ebedd84fba80 launcher/fx/src/test/java/org/apidesign/bck2brwsr/launcher/fximpl/JsMethods.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/launcher/fx/src/test/java/org/apidesign/bck2brwsr/launcher/fximpl/JsMethods.java	Mon Jun 10 18:12:38 2013 +0200
@@ -0,0 +1,38 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.bck2brwsr.launcher.fximpl;
+
+import org.apidesign.bck2brwsr.core.JavaScriptBody;
+
+/**
+ *
+ * @author Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ */
+public class JsMethods {
+    @JavaScriptBody(args = {}, body = "return 42;")
+    public static Object fortyTwo() {
+        return -42;
+    }
+    
+/*
+    @JavaScriptBody(args = {"x", "y" }, body = "return x + y;")
+    public static int plus(int x, int y) {
+        return 0;
+    }
+ */   
+}