Handling static lambda calls

rt/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeParser.java

@@ -1626,9 +1626,9 @@ public String[] getAccess() {
     } // end InnerClassData
 
     static class BootMethodData {
-        private final ClassData clazz;
+        final ClassData clazz;
         final int method;
-        private final int[] args;
+        final int[] args;
 
         private BootMethodData(ClassData clazz, int method, int[] args) {
             this.clazz = clazz;

rt/vm/src/main/java/org/apidesign/vm4brwsr/ByteCodeToJavaScript.java

@@ -258,13 +258,22 @@ private String compileImpl(Appendable out, final String cn) throws IOException {
         out.append("\n    function ").append(className).append("fillInstOf(x) {");
         String instOfName = "$instOf_" + className;
         out.append("\n        Object.defineProperty(x, '").append(instOfName).append("', { value : true });");
+        MethodData functionalInterfaceMethod = null;
         if (jc.isInterface()) {
+            int cnt = 0;
             for (MethodData m : jc.getMethods()) {
-                if ((m.getAccess() & ACC_ABSTRACT) == 0
-                    && (m.getAccess() & ACC_STATIC) == 0
-                    && (m.getAccess() & ACC_PRIVATE) == 0) {
-                    final String mn = findMethodName(m, new StringBuilder());
-                    out.append("\n        if (!x['").append(mn).append("']) Object.defineProperty(x, '").append(mn).append("', { value : c['").append(mn).append("']});");
+                if ((m.getAccess() & ACC_ABSTRACT) == 0) {
+                    if ((m.getAccess() & ACC_STATIC) == 0
+                        && (m.getAccess() & ACC_PRIVATE) == 0) {
+                        final String mn = findMethodName(m, new StringBuilder());
+                        out.append("\n        if (!x['").append(mn).append("']) Object.defineProperty(x, '").append(mn).append("', { value : c['").append(mn).append("']});");
+                    }
+                } else {
+                    functionalInterfaceMethod = m;
+                    cnt++;
+                }
+                if (cnt != 1) {
+                    functionalInterfaceMethod = null;
                 }
             }
         }
@@ -282,6 +291,14 @@ private String compileImpl(Appendable out, final String cn) throws IOException {
         out.append(accessClass("java_lang_Class")).append("(true);");
         out.append("\n    CLS.$class.jvmName = '").append(cn).append("';");
         out.append("\n    CLS.$class.superclass = sprcls;");
+        if (functionalInterfaceMethod != null) {
+            final String mn = findMethodName(functionalInterfaceMethod, new StringBuilder());
+            out.append("\n    CLS.$class.functional = function(arr, fn) {");
+            out.append("\n      var inst = new CLS();");
+            out.append("\n      inst['").append(mn).append("'] = function() { return fn(arr, arguments); };");
+            out.append("\n      return inst;");
+            out.append("\n    };");
+        }
         out.append("\n    CLS.$class.interfaces = function() { return [");
         {
             boolean first = true;
@@ -542,7 +559,7 @@ static int readShortArg(byte[] byteCodes, int offsetInstruction) {
         return readShort(byteCodes, offsetInstruction + 1);
     }
 
-    private static void countArgs(String descriptor, char[] returnType, StringBuilder sig, StringBuilder cnt) {
+    static void countArgs(String descriptor, char[] returnType, StringBuilder sig, StringBuilder cnt) {
         int i = 0;
         Boolean count = null;
         boolean array = false;

rt/vm/src/main/java/org/apidesign/vm4brwsr/IndyHandler.java

@@ -17,6 +17,8 @@
  */
 package org.apidesign.vm4brwsr;
 
+import java.io.IOException;
+
 abstract class IndyHandler {
     final String factoryClazz;
     final String factoryMethod;
@@ -26,13 +28,19 @@ abstract class IndyHandler {
         this.factoryMethod = method;
     }
 
-    protected abstract boolean handle(Ctx ctx);
+    protected abstract boolean handle(Ctx ctx) throws IOException ;
 
     static class Ctx {
+        final Appendable out;
+        final StackMapper stackMapper;
+        final ByteCodeToJavaScript byteCodeToJavaScript;
         final ByteCodeParser.BootMethodData bm;
         final String[] mt;
 
-        Ctx(String[] methodAndType, ByteCodeParser.BootMethodData bm) {
+        Ctx(Appendable out, StackMapper m, ByteCodeToJavaScript bc, String[] methodAndType, ByteCodeParser.BootMethodData bm) {
+            this.out = out;
+            this.stackMapper = m;
+            this.byteCodeToJavaScript = bc;
             this.mt = methodAndType;
             this.bm = bm;
         }

rt/vm/src/main/java/org/apidesign/vm4brwsr/LoopCode.java

@@ -1014,7 +1014,7 @@ void loopCode(
     private void handleIndy(int indx, String[] methodAndType, String[] mi, ByteCodeParser.BootMethodData bm, StackMapper mapper) throws IOException {
         for (IndyHandler h : byteCodeToJavaScript.getIndyHandlers()) {
             if (h.factoryClazz.equals(mi[0]) && h.factoryMethod.equals(mi[1])) {
-                IndyHandler.Ctx ctx = new IndyHandler.Ctx(methodAndType, bm);
+                IndyHandler.Ctx ctx = new IndyHandler.Ctx(out, mapper, byteCodeToJavaScript, methodAndType, bm);
                 if (h.handle(ctx)) {
                     return;
                 }

rt/vm/src/main/java/org/apidesign/vm4brwsr/MetafactoryHandler.java

@@ -17,17 +17,82 @@
  */
 package org.apidesign.vm4brwsr;
 
+import java.io.IOException;
+
 final class MetafactoryHandler extends IndyHandler {
     MetafactoryHandler() {
         super("java/lang/invoke/LambdaMetafactory", "metafactory");
     }
 
     @Override
-    protected boolean handle(Ctx ctx) {
-        for (int i = 0; i < ctx.bm.getArguments(); i++) {
-            System.err.println("  arg#" + i + " = " + ctx.bm.getArgument(i));
+    protected boolean handle(Ctx ctx) throws IOException {
+        final int fixedArgsCount;
+        {
+            final String sig = ctx.mt[1];
+            int typeEnd = sig.lastIndexOf(')');
+            String typeSig = sig.substring(typeEnd + 1);
+            if (!typeSig.startsWith("L") || !typeSig.endsWith(";")) {
+                return false;
+            }
+            final String type = typeSig.substring(1, typeSig.length() - 1);
+            ctx.byteCodeToJavaScript.requireReference(type);
+            final String mangledType = ByteCodeToJavaScript.mangleClassName(type);
+            String interfaceToCreate = ctx.byteCodeToJavaScript.accessClassFalse(mangledType);
+
+            StringBuilder sigB = new StringBuilder();
+            StringBuilder cnt = new StringBuilder();
+            char[] returnType = { 'V' };
+            boolean isStatic = true;
+            ByteCodeToJavaScript.countArgs(sig, returnType, sigB, cnt);
+
+            fixedArgsCount = isStatic ? cnt.length() : cnt.length() + 1;
+            final CharSequence[] vars = new CharSequence[fixedArgsCount];
+            for (int j = fixedArgsCount - 1; j >= 0; --j) {
+                vars[j] = ctx.stackMapper.popValue();
+            }
+
+            assert returnType[0] == 'L';
+
+            ctx.stackMapper.flush(ctx.out);
+
+            final Variable samVar = ctx.stackMapper.pushA();
+            ctx.out.append("var ").append(samVar).append(" = ").append(interfaceToCreate).append(".constructor.$class.functional([");
+
+            String sep = "";
+            for (int j = 0; j < fixedArgsCount; j++) {
+                ctx.out.append(sep).append(vars[j]);
+                sep = ", ";
+            }
+
+            ctx.out.append("], function(args1, args2) {\n");
+        }
+        {
+            ByteCodeParser.CPX2 methodHandle = ctx.bm.clazz.getCpoolEntry(ctx.bm.args[1]);
+
+            String[] methodInfoName = ctx.bm.clazz.getFieldInfoName(methodHandle.cpx2);
+            ctx.byteCodeToJavaScript.requireReference(methodInfoName[0]);
+            final String mangledType = ByteCodeToJavaScript.mangleClassName(methodInfoName[0]);
+            StringBuilder cnt = new StringBuilder();
+            char[] returnType = { 'V' };
+            String mangledMethod = ByteCodeToJavaScript.findMethodName(methodInfoName, cnt, returnType);
+
+            ctx.out.append("\n      return ");
+            ctx.out.append(ctx.byteCodeToJavaScript.accessClassFalse(mangledType));
+            ctx.out.append(".").append(mangledMethod).append('(');
+            String sep = "";
+            for (int i = 0; i < cnt.length(); i++) {
+                ctx.out.append(sep);
+                if (i < fixedArgsCount) {
+                    ctx.out.append("args1[" + i + "]");
+                } else {
+                    ctx.out.append("args2[" + (i - fixedArgsCount) + "]");
+                }
+                sep = ", ";
+            }
+            ctx.out.append(");");
+            ctx.out.append("\n   })");
         }
-        return false;
+        return true;
     }
 
 }

rt/vm8/src/test/java/org/apidesign/bck2brwsr/vm8/SamTest.java

@@ -0,0 +1,38 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012-2018 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.vm8;
+
+import org.apidesign.bck2brwsr.vmtest.Compare;
+import org.apidesign.bck2brwsr.vmtest.VMTest;
+import org.testng.annotations.Factory;
+
+public class SamTest {
+
+    @Compare
+    public int staticLambdas() {
+        int[] sum = {0};
+        Functions.Compute<Integer> inc = () -> sum[0]++;
+        Functions.Compute<Integer> ret = () -> sum[0];
+        inc.get();
+        return ret.get();
+    }
+
+    @Factory public static Object[] create() {
+        return VMTest.create(SamTest.class);
+    }
+}