All classes loaded through the 'vm' object will have 'invoke' method that can be used to invoke static methods like main(String[]), so our examples no longer need to rely on initialization in static initializers.
2 * Back 2 Browser Bytecode Translator
3 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, version 2 of the License.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. Look for COPYING file in the top folder.
16 * If not, see http://opensource.org/licenses/GPL-2.0.
18 package org.apidesign.vm4brwsr;
20 import java.io.IOException;
21 import java.io.InputStream;
22 import org.apidesign.bck2brwsr.core.JavaScriptBody;
23 import org.apidesign.vm4brwsr.ByteCodeParser.ClassData;
24 import org.apidesign.vm4brwsr.ByteCodeParser.FieldData;
25 import org.apidesign.vm4brwsr.ByteCodeParser.MethodData;
27 /** Generator of JavaScript from bytecode of classes on classpath of the VM.
29 * @author Jaroslav Tulach <jtulach@netbeans.org>
31 abstract class VM extends ByteCodeToJavaScript {
32 protected final ClassDataCache classDataCache;
34 private final Bck2Brwsr.Resources resources;
35 private final ExportedSymbols exportedSymbols;
36 private final StringArray invokerMethods;
37 private final StringArray asBinary;
40 Appendable out, Bck2Brwsr.Resources resources,
41 StringArray explicitlyExported, StringArray asBinary
44 this.resources = resources;
45 this.classDataCache = new ClassDataCache(resources);
46 this.exportedSymbols = new ExportedSymbols(resources, explicitlyExported);
47 this.invokerMethods = new StringArray();
48 this.asBinary = asBinary;
52 // uses VMLazy to load dynamic classes
53 boolean assertsOn = false;
54 assert assertsOn = true;
62 boolean debug(String msg) throws IOException {
66 static void compile(Appendable out,
68 ) throws IOException {
69 String[] both = config.classes().toArray();
71 final StringArray fixedNames = new StringArray();
72 fixedNames.add(Class.class.getName().replace('.', '/'));
73 fixedNames.add(ArithmeticException.class.getName().replace('.', '/'));
76 if (config.isExtension()) {
77 fixedNames.add(VM.class.getName().replace('.', '/'));
78 vm = new Extension(out,
79 config.getResources(), both, config.exported(),
80 config.allResources(), config.classpath()
83 if (config.includeVM()) {
84 fixedNames.add(VM.class.getName().replace('.', '/'));
86 vm = new Standalone(out,
87 config.getResources(), config.exported(),
91 vm.doCompile(fixedNames.addAndNew(both));
94 private void doCompile(StringArray names) throws IOException {
97 "\n var invoker = {};");
99 for (String invokerMethod: invokerMethods.toArray()) {
100 append("\n invoker." + invokerMethod + " = function(target) {"
101 + "\n return function() {"
102 + "\n return target['" + invokerMethod + "'].apply(target, arguments);"
108 for (String r : asBinary.toArray()) {
109 append("\n ").append(getExportsObject()).append("['registerResource']('");
110 append(r).append("', '");
111 InputStream is = this.resources.get(r);
112 byte[] arr = new byte[is.available()];
115 if (offset == arr.length) {
116 byte[] tmp = new byte[arr.length * 2];
117 System.arraycopy(arr, 0, tmp, 0, arr.length);
120 int len = is.read(arr, offset, arr.length - offset);
126 if (offset != arr.length) {
127 byte[] tmp = new byte[offset];
128 System.arraycopy(arr, 0, tmp, 0, offset);
139 @JavaScriptBody(args = { "arr" }, body = "return btoa(arr);")
140 private static String btoa(byte[] arr) {
141 return javax.xml.bind.DatatypeConverter.printBase64Binary(arr);
144 protected abstract void generatePrologue() throws IOException;
146 protected abstract void generateEpilogue() throws IOException;
148 protected abstract String getExportsObject();
150 protected abstract boolean isExternalClass(String className);
153 protected final void declaredClass(ClassData classData, String mangledName)
155 if (exportedSymbols.isExported(classData)) {
156 append("\n").append(getExportsObject()).append("['")
159 .append(accessClass(mangledName))
164 protected String generateClass(String className) throws IOException {
165 ClassData classData = classDataCache.getClassData(className);
166 if (classData == null) {
167 throw new IOException("Can't find class " + className);
169 return compile(classData);
173 protected void declaredField(FieldData fieldData,
175 String mangledName) throws IOException {
176 if (exportedSymbols.isExported(fieldData)) {
177 exportMember(destObject, mangledName);
182 protected void declaredMethod(MethodData methodData,
184 String mangledName) throws IOException {
185 if (isHierarchyExported(methodData)) {
186 exportMember(destObject, mangledName);
190 private void exportMember(String destObject, String memberName)
192 append("\n").append(destObject).append("['")
195 .append(destObject).append(".").append(memberName)
199 private void generateBody(StringArray names) throws IOException {
200 StringArray processed = new StringArray();
201 StringArray initCode = new StringArray();
202 StringArray skipClass = new StringArray();
203 for (String baseClass : names.toArray()) {
204 references.add(baseClass);
207 for (String n : references.toArray()) {
208 if (skipClass.contains(n)) {
211 if (processed.contains(n)) {
219 InputStream is = resources.get(name + ".class");
221 lazyReference(this, name);
226 String ic = generateClass(name);
228 initCode.add(ic == null ? "" : ic);
229 } catch (RuntimeException ex) {
230 throw new IOException("Error while compiling " + name + "\n", ex);
234 for (String resource : scripts.toArray()) {
235 while (resource.startsWith("/")) {
236 resource = resource.substring(1);
238 InputStream emul = resources.get(resource);
240 throw new IOException("Can't find " + resource);
242 readResource(emul, this);
243 asBinary.remove(resource);
245 scripts = new StringArray();
247 StringArray toInit = StringArray.asList(references.toArray());
250 for (String ic : toInit.toArray()) {
251 int indx = processed.indexOf(ic);
253 final String theCode = initCode.toArray()[indx];
254 if (!theCode.isEmpty()) {
255 append(theCode).append("\n");
257 initCode.toArray()[indx] = "";
263 private static void readResource(InputStream emul, Appendable out) throws IOException {
267 int ch = emul.read();
271 if (ch < 0 || ch > 255) {
272 throw new IOException("Invalid char in emulation " + ch);
279 out.append((char)ch);
286 out.append('/').append((char)ch);
309 static String toString(String name) throws IOException {
310 StringBuilder sb = new StringBuilder();
311 // compile(sb, name);
312 return sb.toString().toString();
315 private StringArray scripts = new StringArray();
316 private StringArray references = new StringArray();
319 protected boolean requireReference(String cn) {
320 if (references.contains(cn)) {
328 protected void requireScript(String resourcePath) {
329 scripts.add(resourcePath);
333 String assignClass(String className) {
334 return "vm." + className + " = ";
338 String accessClass(String className) {
339 return "vm." + className;
343 protected String accessField(String object, String mangledName,
344 String[] fieldInfoName) throws IOException {
345 final FieldData field =
346 classDataCache.findField(fieldInfoName[0],
349 return accessNonVirtualMember(object, mangledName,
350 (field != null) ? field.cls : null);
354 protected String accessStaticMethod(
357 String[] fieldInfoName) throws IOException {
358 final MethodData method =
359 classDataCache.findMethod(fieldInfoName[0],
362 return accessNonVirtualMember(object, mangledName,
363 (method != null) ? method.cls : null);
367 protected String accessVirtualMethod(
370 String[] fieldInfoName) throws IOException {
371 final ClassData referencedClass =
372 classDataCache.getClassData(fieldInfoName[0]);
373 final MethodData method =
374 classDataCache.findMethod(referencedClass,
379 && !isExternalClass(method.cls.getClassName())
380 && (((method.access & ByteCodeParser.ACC_FINAL) != 0)
381 || ((referencedClass.getAccessFlags()
382 & ByteCodeParser.ACC_FINAL) != 0)
383 || !isHierarchyExported(method))) {
384 return object + "." + mangledName;
387 return accessThroughInvoker(object, mangledName);
390 private String accessThroughInvoker(String object, String mangledName) {
391 if (!invokerMethods.contains(mangledName)) {
392 invokerMethods.add(mangledName);
394 return "invoker." + mangledName + '(' + object + ')';
397 private boolean isHierarchyExported(final MethodData methodData)
399 if (exportedSymbols.isExported(methodData)) {
402 if ((methodData.access & (ByteCodeParser.ACC_PRIVATE
403 | ByteCodeParser.ACC_STATIC)) != 0) {
407 final ExportedMethodFinder exportedMethodFinder =
408 new ExportedMethodFinder(exportedSymbols);
410 classDataCache.findMethods(
412 methodData.getName(),
413 methodData.getInternalSig(),
414 exportedMethodFinder);
416 return (exportedMethodFinder.getFound() != null);
419 private String accessNonVirtualMember(String object,
421 ClassData declaringClass) {
422 return ((declaringClass != null)
423 && !isExternalClass(declaringClass.getClassName()))
424 ? object + "." + mangledName
425 : object + "['" + mangledName + "']";
428 private static final class ExportedMethodFinder
429 implements ClassDataCache.TraversalCallback<MethodData> {
430 private final ExportedSymbols exportedSymbols;
431 private MethodData found;
433 public ExportedMethodFinder(final ExportedSymbols exportedSymbols) {
434 this.exportedSymbols = exportedSymbols;
438 public boolean traverse(final MethodData methodData) {
440 if (exportedSymbols.isExported(methodData)) {
444 } catch (final IOException e) {
450 public MethodData getFound() {
455 private static final class Standalone extends VM {
456 private Standalone(Appendable out,
457 Bck2Brwsr.Resources resources,
458 StringArray explicitlyExported, StringArray asBinary
460 super(out, resources, explicitlyExported, asBinary);
464 protected void generatePrologue() throws IOException {
465 append("(function VM(global) {var fillInVMSkeleton = function(vm) {");
469 protected void generateEpilogue() throws IOException {
473 + " var extensions = [];\n"
474 + " function replaceAll(s, target, replacement) {\n"
477 + " var indx = s.indexOf(target, pos);\n"
478 + " if (indx === -1) {\n"
481 + " pos = indx + replacement.length;\n"
482 + " s = s.substring(0, indx) + replacement + s.substring(indx + target.length);\n"
485 + " function mangleClass(name) {\n"
486 + " name = replaceAll(name, '_', '_1');\n"
487 + " name = replaceAll(name, '.', '_');\n"
490 + " var pending = [];\n"
491 + " var pendingClasses = [];\n"
492 + " function extensionLoaded(ev) {\n"
493 + " var at = pending.indexOf(ev.target);\n"
494 + " pending.splice(at, 1);\n"
495 + " if (pending.length === 0) {\n"
496 + " for (var i = 0; i < pendingClasses.length; i += 3) {\n"
497 + " invokeMethod(pendingClasses[i], pendingClasses[i + 1], pendingClasses[i + 2]);\n"
499 + " pendingClasses = [];\n"
502 + " function invokeMethod(vm, n, args) {\n"
503 + " var clazz = vm.loadClass(n);\n"
505 + " var seek = args[0];\n"
506 + " var prefix = seek.indexOf('__') == -1 ? seek + '__' : seek;\n"
507 + " args = Array.prototype.slice.call(args, 1);\n"
508 + " var found = '';\n"
509 + " for (var m in clazz) {\n"
510 + " if (m.indexOf(prefix) === 0) {\n"
511 + " return clazz[m].apply(null, args);\n"
513 + " found += m.toString() + '\\n'\n"
515 + " throw 'Cannot find ' + seek + ' in ' + n + ' found:\\n' + found;\n"
518 + " function extensionError(ev) {\n"
519 + " console.log('error loading ' + ev.target.src);\n"
520 + " extensionLoaded(ev);\n"
522 + " function loadExtension(url) {\n"
523 + " if (url.substring(url.length - 4) == '.jar')\n"
524 + " url = url.substring(0, url.length - 4) + '.js';\n"
525 + " var script = document.createElement('script');\n"
526 + " script.type = 'text/javascript';\n"
527 + " script.src = url;\n"
528 + " script.onload = extensionLoaded;\n"
529 + " script.onerror = extensionError;\n"
530 + " document.getElementsByTagName('head')[0].appendChild(script);\n"
531 + " pending.push(script);\n"
533 + " global.bck2brwsr = function() {\n"
534 + " var args = Array.prototype.slice.apply(arguments);\n"
535 + " var resources = {};\n"
536 + " function registerResource(n, a64) {\n"
537 + " var str = atob(a64);\n"
539 + " for (var i = 0; i < str.length; i++) {\n"
540 + " var ch = str.charCodeAt(i) & 0xff;\n"
541 + " if (ch > 127) ch -= 256;\n"
544 + " if (!resources[n]) resources[n] = [arr];\n"
545 + " else resources[n].push(arr);\n"
547 + " var vm = fillInVMSkeleton({ 'registerResource' : registerResource });\n"
548 + " function initVM() {\n"
549 + " var clsArray = vm['java_lang_reflect_Array'];\n"
550 + " if (clsArray) clsArray(false);\n"
552 + " for (var i = 0; i < extensions.length; ++i) {\n"
553 + " extensions[i](vm);\n"
555 + " vm['registerResource'] = null;\n"
556 + " var knownExtensions = extensions.length;\n"
557 + " var loader = {};\n"
558 + " var loadBytes = function(name, skip) {\n"
559 + " skip = typeof skip == 'number' ? skip : 0;\n"
560 + " var arr = resources[name];\n"
562 + " var arrSize = arr.length;\n"
563 + " if (skip < arrSize) return arr[skip];\n"
564 + " skip -= arrSize;\n"
566 + " var arrSize = 0;\n"
568 + " for (var i = 0; i < args.length; i++) {\n"
569 + " var at = args[i];\n"
570 + " if(!at) continue;\n"
572 + " if (typeof at === 'string' && at.substring(at.length - 3) === '.js') {\n"
573 + " loadExtension(at);\n"
574 + " args[i] = null;\n"
575 + " } else if (typeof at === 'function') ret = at(name, skip);\n"
577 + " var cp = vm['org_apidesign_vm4brwsr_ClassPath'];\n"
578 + " if (!cp) throw 'Core Java library not registered. Cannot load from ' + at;\n"
579 + " ret = cp(false).\n"
580 + " loadBytes___3BLjava_lang_String_2Ljava_lang_Object_2II(name, args, i, skip);\n"
582 + " if (ret) return ret;\n"
584 + " while (knownExtensions < extensions.length) {\n"
585 + " vm['registerResource'] = registerResource;\n"
586 + " extensions[knownExtensions++](vm);\n"
587 + " vm['registerResource'] = null;\n"
590 + " var arr = resources[name];\n"
591 + " return (arr && arr.length > arrSize) ? arr[arrSize] : null;\n"
593 + " var reload = function(name, arr, keep) {\n"
594 + " if (!arr) throw 'Cannot find ' + name;\n"
595 + " var lazy = vm['org_apidesign_vm4brwsr_VMLazy'];\n"
596 + " if (!lazy) throw 'No bck2brwsr VM module to compile ' + name;\n"
598 + " var attr = mangleClass(name);\n"
599 + " delete vm[attr];\n"
601 + " return lazy(false)\n"
602 + " ['load__Ljava_lang_Object_2Ljava_lang_Object_2Ljava_lang_String_2_3Ljava_lang_Object_2_3B']\n"
603 + " (vm, name, args, arr);\n"
605 + " var loadClass = function(name) {\n"
606 + " var attr = mangleClass(name);\n"
607 + " var fn = vm[attr];\n"
608 + " if (fn) return fn(false);\n"
610 + " var arr = loadBytes(replaceAll(name, '.', '/') + '.class');\n"
611 + " return reload(name, arr, true);\n"
612 + " } catch (err) {\n"
613 + " fn = vm[attr];\n"
614 + " if (fn) return fn(false);\n"
618 + " if (vm['loadClass']) {\n"
619 + " throw 'Cannot initialize the bck2brwsr VM twice!';\n"
621 + " vm['loadClass'] = loadClass;\n"
622 + " vm['_reload'] = reload;\n"
623 + " vm['loadBytes'] = loadBytes;\n"
625 + " loader.loadClass = function(name) {\n"
626 + " if (pending.length === 0) {\n"
628 + " var c = loadClass(name);\n"
629 + " c['invoke'] = function() {\n"
630 + " return invokeMethod(vm, name, arguments);\n"
633 + " } catch (err) {\n"
634 + " if (pending.length === 0) throw err;\n"
637 + " pendingClasses.push(vm);\n"
638 + " pendingClasses.push(name);\n"
639 + " pendingClasses.push(null);\n"
641 + " 'invoke' : function() {\n"
642 + " if (pending.length === 0) {\n"
643 + " invokeMethod(vm, name, arguments);\n"
646 + " pendingClasses.push(vm);\n"
647 + " pendingClasses.push(name);\n"
648 + " pendingClasses.push(arguments);\n"
652 + " return loader;\n"
655 " global.bck2brwsr.register = function(config, extension) {\n"
656 + " if (!config || config['magic'] !== 'kafíčko') {\n"
657 + " console.log('Will not register: ' + extension);\n"
660 + " extensions.push(extension);\n"
661 + " var cp = config['classpath'];\n"
662 + " if (cp) for (var i = 0; i < cp.length; i++) {\n"
663 + " loadExtension(cp[i]);\n"
671 protected String getExportsObject() {
676 protected boolean isExternalClass(String className) {
681 private static final class Extension extends VM {
682 private final StringArray extensionClasses;
683 private final StringArray classpath;
685 private Extension(Appendable out, Bck2Brwsr.Resources resources,
686 String[] extClassesArray, StringArray explicitlyExported,
687 StringArray asBinary, StringArray classpath
689 super(out, resources, explicitlyExported, asBinary);
690 this.extensionClasses = StringArray.asList(extClassesArray);
691 this.classpath = classpath;
695 protected void generatePrologue() throws IOException {
697 "bck2brwsr.register({\n"
698 + " 'magic' : 'kafíčko'"
700 if (classpath != null && classpath.toArray().length > 0) {
702 ",\n 'classpath' : [\n"
705 for (String s : classpath.toArray()) {
706 append(sep).append("'").append(s).append("'");
714 "\n}, function(exports) {\n"
715 + " var vm = {};\n");
716 append(" function link(n) {\n"
717 + " return function() {\n"
718 + " var cls = n['replace__Ljava_lang_String_2CC']"
719 + "('/', '_').toString();\n"
720 + " var dot = n['replace__Ljava_lang_String_2CC']"
721 + "('/', '.').toString();\n"
722 + " exports.loadClass(dot);\n"
723 + " vm[cls] = exports[cls];\n"
724 + " return vm[cls](arguments);\n"
731 protected void generateEpilogue() throws IOException {
736 protected String generateClass(String className) throws IOException {
737 if (isExternalClass(className)) {
738 append("\n").append(assignClass(
739 className.replace('/', '_')))
747 return super.generateClass(className);
751 protected String getExportsObject() {
756 protected boolean isExternalClass(String className) {
757 return !extensionClasses.contains(className);
761 private static void lazyReference(Appendable out, String n) throws IOException {
762 String cls = n.replace('/', '_');
763 String dot = n.replace('/', '.');
765 out.append("\nvm.").append(cls).append(" = function() {");
766 out.append("\n var instance = arguments.length == 0 || arguments[0] === true;");
767 out.append("\n delete vm.").append(cls).append(";");
768 out.append("\n var c = vm.loadClass('").append(dot).append("');");
769 out.append("\n return vm.").append(cls).append("(instance);");