2 * Back 2 Browser Bytecode Translator
3 * Copyright (C) 2012-2015 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 StringBuilder invokerMethods;
37 private final StringArray asBinary;
41 Appendable out, Bck2Brwsr.Resources resources,
42 StringArray explicitlyExported, StringArray asBinary
45 this.resources = resources;
46 this.classDataCache = new ClassDataCache(resources);
47 this.exportedSymbols = new ExportedSymbols(resources, explicitlyExported);
48 this.invokerMethods = new StringBuilder();
49 this.asBinary = asBinary;
53 // uses VMLazy to load dynamic classes
54 boolean assertsOn = false;
55 assert assertsOn = true;
63 boolean debug(String msg) throws IOException {
67 static void compile(Appendable out,
69 ) throws IOException {
70 String[] both = config.classes().toArray();
72 final StringArray fixedNames = new StringArray();
73 fixedNames.add(Object.class.getName().replace('.', '/'));
74 fixedNames.add(Class.class.getName().replace('.', '/'));
75 fixedNames.add(ArithmeticException.class.getName().replace('.', '/'));
78 if (config.isExtension()) {
79 fixedNames.add(VM.class.getName().replace('.', '/'));
80 vm = new Extension(out,
81 config.getResources(), both, config.exported(),
82 config.allResources(), config.classpath()
85 if (config.includeVM()) {
86 fixedNames.add(VM.class.getName().replace('.', '/'));
88 vm = new Standalone(out,
89 config.getResources(), config.exported(),
93 vm.doCompile(fixedNames.addAndNew(both));
96 private void doCompile(StringArray names) throws IOException {
99 "\n var invoker = {};");
101 append(invokerMethods);
103 for (String r : asBinary.toArray()) {
104 append("\n ").append(getExportsObject()).append("['registerResource']('");
105 append(r).append("', '");
106 InputStream is = this.resources.get(r);
107 byte[] arr = new byte[is.available()];
110 if (offset == arr.length) {
111 byte[] tmp = new byte[arr.length * 2];
112 System.arraycopy(arr, 0, tmp, 0, arr.length);
115 int len = is.read(arr, offset, arr.length - offset);
121 if (offset != arr.length) {
122 byte[] tmp = new byte[offset];
123 System.arraycopy(arr, 0, tmp, 0, offset);
134 @JavaScriptBody(args = { "arr" }, body = "return btoa(arr);")
135 private static String btoa(byte[] arr) {
136 return javax.xml.bind.DatatypeConverter.printBase64Binary(arr);
139 protected abstract void generatePrologue() throws IOException;
141 protected abstract void generateEpilogue() throws IOException;
143 protected abstract String getExportsObject();
145 protected abstract boolean isExternalClass(String className);
147 protected abstract void lazyReference(Appendable out, String n) throws IOException;
150 protected final void declaredClass(ClassData classData, String mangledName)
152 if (exportedSymbols.isExported(classData)) {
153 append("\n").append(getExportsObject()).append("['")
156 .append(accessClass(mangledName))
162 protected String generateClass(String className) throws IOException {
163 ClassData classData = classDataCache.getClassData(className);
164 if (classData == null) {
165 throw new IOException("Can't find class " + className);
167 return compile(classData);
171 protected void declaredField(FieldData fieldData,
173 String mangledName) throws IOException {
174 if (exportedSymbols.isExported(fieldData)) {
175 exportMember(destObject, mangledName);
180 protected void declaredMethod(MethodData methodData,
182 String mangledName) throws IOException {
183 if (isHierarchyExported(methodData)) {
184 exportMember(destObject, mangledName);
188 private void exportMember(String destObject, String memberName)
190 append("\n").append(destObject).append("['")
192 .append("'] = m;\n");
195 private void generateBody(StringArray names) throws IOException {
196 StringArray processed = new StringArray();
197 StringArray initCode = new StringArray();
198 StringArray skipClass = new StringArray();
199 for (String baseClass : names.toArray()) {
200 references.add(baseClass);
203 for (String n : references.toArray()) {
204 if (skipClass.contains(n)) {
207 if (processed.contains(n)) {
215 InputStream is = resources.get(name + ".class");
217 lazyReference(this, name);
222 String ic = generateClass(name);
224 initCode.add(ic == null ? "" : ic);
225 } catch (RuntimeException ex) {
226 throw new IOException("Error while compiling " + name + "\n", ex);
230 for (String resource : scripts.toArray()) {
231 while (resource.startsWith("/")) {
232 resource = resource.substring(1);
234 requireResourceImpl(resource);
235 asBinary.remove(resource);
237 scripts = new StringArray();
239 StringArray toInit = StringArray.asList(references.toArray());
242 for (String ic : toInit.toArray()) {
243 int indx = processed.indexOf(ic);
245 final String theCode = initCode.toArray()[indx];
246 if (!theCode.isEmpty()) {
247 append(theCode).append("\n");
249 initCode.toArray()[indx] = "";
255 final void requireResourceImpl(String resource) throws IOException {
256 InputStream emul = resources.get(resource);
258 throw new IOException("Can't find " + resource);
260 append("\n// resource from ").append(resource).append("\n");
261 readResource(emul, this);
265 private static void readResource(InputStream emul, Appendable out) throws IOException {
269 int ch = emul.read();
273 if (ch < 0 || ch > 255) {
274 throw new IOException("Invalid char in emulation " + ch);
276 out.append((char)ch);
283 static String toString(String name) throws IOException {
284 StringBuilder sb = new StringBuilder();
285 // compile(sb, name);
286 return sb.toString().toString();
289 private StringArray scripts = new StringArray();
290 private StringArray references = new StringArray();
293 protected boolean requireReference(String cn) {
294 return references.addIfMissing(cn);
298 protected void requireScript(String resourcePath) {
299 scripts.add(resourcePath);
303 String assignClass(String className) {
304 return "vm." + className + " = ";
308 String accessClass(String className) {
309 return "vm." + className;
313 protected FieldData findField(String[] fieldInfoName) throws IOException {
314 FieldData field = classDataCache.findField(
315 fieldInfoName[0], fieldInfoName[1], fieldInfoName[2]
317 return field != null && canAccessDirectly(field.cls) ? field : null;
321 protected String accessField(String object, FieldData field, String[] fieldInfoName)
324 return "fld_" + object + "_" + field.getName();
326 String mangledName = "_" + fieldInfoName[1];
327 return accessNonVirtualMember(object, mangledName, null);
332 protected String accessStaticMethod(
335 String[] fieldInfoName) throws IOException {
336 final MethodData method =
337 classDataCache.findMethod(fieldInfoName[0],
340 return accessNonVirtualMember(object, mangledName,
341 (method != null) ? method.cls : null);
345 protected String accessVirtualMethod(
348 String[] fieldInfoName,
350 ) throws IOException {
351 final ClassData referencedClass =
352 classDataCache.getClassData(fieldInfoName[0]);
353 final MethodData method =
354 classDataCache.findMethod(referencedClass,
359 && !isExternalClass(method.cls.getClassName())
360 && (((method.access & ByteCodeParser.ACC_FINAL) != 0)
361 || ((referencedClass.getAccessFlags()
362 & ByteCodeParser.ACC_FINAL) != 0)
363 || !isHierarchyExported(method))) {
364 return object + "." + mangledName + '(';
367 return accessThroughInvoker(object, mangledName, params);
370 private String accessThroughInvoker(String object, String mangledName, int params)
372 String def = "\n invoker." + mangledName + " = function(target";
373 if (invokerMethods.indexOf(def) == -1) {
374 invokerMethods.append(def);
375 for (int j = 0; j < params; j++) {
376 invokerMethods.append(", p").append(j);
378 invokerMethods.append(") {\n return target['").
379 append(mangledName).append("'](");
380 for (int j = 0; j < params; j++) {
382 invokerMethods.append(",");
384 invokerMethods.append("p").append(j);
386 invokerMethods.append(");\n };");
388 return "invoker." + mangledName + '(' + object + (params > 1 ? "," : "");
391 private boolean isHierarchyExported(final MethodData methodData)
393 if (exportedSymbols.isExported(methodData)) {
396 if ((methodData.access & (ByteCodeParser.ACC_PRIVATE
397 | ByteCodeParser.ACC_STATIC)) != 0) {
401 final ExportedMethodFinder exportedMethodFinder =
402 new ExportedMethodFinder(exportedSymbols);
404 classDataCache.findMethods(
406 methodData.getName(),
407 methodData.getInternalSig(),
408 exportedMethodFinder);
410 return (exportedMethodFinder.getFound() != null);
413 private boolean canAccessDirectly(ClassData declaringClass) {
414 if (declaringClass == null) {
417 final String className = declaringClass.getClassName();
419 "java/lang/Object".equals(className) ||
420 "java/lang/reflect/Array".equals(className) ||
421 isExternalClass(className)
428 private String accessNonVirtualMember(
429 String object, String mangledName, ClassData declaringClass
431 return canAccessDirectly(declaringClass) ?
432 object + "." + mangledName :
433 object + "['" + mangledName + "']";
436 private final class ExportedMethodFinder
437 implements ClassDataCache.TraversalCallback<MethodData> {
438 private final ExportedSymbols exportedSymbols;
439 private MethodData found;
441 public ExportedMethodFinder(final ExportedSymbols exportedSymbols) {
442 this.exportedSymbols = exportedSymbols;
446 public boolean traverse(final MethodData methodData) {
449 exportedSymbols.isExported(methodData) ||
450 isExternalClass(methodData.cls.getClassName())
455 } catch (final IOException e) {
461 public MethodData getFound() {
466 private static final class Standalone extends VM {
467 private Standalone(Appendable out,
468 Bck2Brwsr.Resources resources,
469 StringArray explicitlyExported, StringArray asBinary
471 super(out, resources, explicitlyExported, asBinary);
475 protected void generatePrologue() throws IOException {
476 append("(function VM(global) {var fillInVMSkeleton = function(vm) {");
480 protected void generateEpilogue() throws IOException {
484 + " var extensions = [];\n"
485 + " function replaceAll(s, target, replacement) {\n"
488 + " var indx = s.indexOf(target, pos);\n"
489 + " if (indx === -1) {\n"
492 + " pos = indx + replacement.length;\n"
493 + " s = s.substring(0, indx) + replacement + s.substring(indx + target.length);\n"
496 + " function mangleClass(name) {\n"
497 + " name = replaceAll(name, '_', '_1');\n"
498 + " name = replaceAll(name, '.', '_');\n"
501 + " var pending = [];\n"
502 + " var pendingClasses = [];\n"
503 + " function extensionLoaded(ev) {\n"
504 + " var at = pending.indexOf(ev.target);\n"
505 + " pending.splice(at, 1);\n"
506 + " if (pending.length === 0) {\n"
507 + " for (var i = 0; i < pendingClasses.length; i += 3) {\n"
508 + " invokeMethod(pendingClasses[i], pendingClasses[i + 1], pendingClasses[i + 2]);\n"
510 + " pendingClasses = [];\n"
513 + " function invokeMethod(vm, n, args) {\n"
514 + " var clazz = vm.loadClass(n);\n"
516 + " var seek = args[0];\n"
517 + " var prefix = seek.indexOf('__') == -1 ? seek + '__' : seek;\n"
518 + " args = Array.prototype.slice.call(args, 1);\n"
519 + " var found = '';\n"
520 + " for (var m in clazz) {\n"
521 + " if (m.indexOf(prefix) === 0) {\n"
522 + " return clazz[m].apply(null, args);\n"
524 + " found += m.toString() + '\\n'\n"
526 + " throw 'Cannot find ' + seek + ' in ' + n + ' found:\\n' + found;\n"
529 + " function extensionError(ev) {\n"
530 + " console.log('error loading ' + ev.target.src);\n"
531 + " extensionLoaded(ev);\n"
533 + " function loadExtension(url) {\n"
534 + " if (url.substring(url.length - 4) == '.jar')\n"
535 + " url = url.substring(0, url.length - 4) + '.js';\n"
536 + " var script = document.createElement('script');\n"
537 + " script.type = 'text/javascript';\n"
538 + " script.src = url;\n"
539 + " script.onload = extensionLoaded;\n"
540 + " script.onerror = extensionError;\n"
541 + " document.getElementsByTagName('head')[0].appendChild(script);\n"
542 + " pending.push(script);\n"
544 + " global.bck2brwsr = function() {\n"
545 + " var args = Array.prototype.slice.apply(arguments);\n"
546 + " var resources = {};\n"
547 + " function registerResource(n, a64) {\n"
548 + " var frm = atob || window.atob;\n"
549 + " var str = frm(a64);\n"
551 + " for (var i = 0; i < str.length; i++) {\n"
552 + " var ch = str.charCodeAt(i) & 0xff;\n"
553 + " if (ch > 127) ch -= 256;\n"
556 + " if (!resources[n]) resources[n] = [arr];\n"
557 + " else resources[n].push(arr);\n"
559 + " var vm = fillInVMSkeleton({ 'registerResource' : registerResource });\n"
560 + " function initVM() {\n"
561 + " var clsArray = vm['java_lang_reflect_Array'];\n"
562 + " if (clsArray) clsArray(false);\n"
564 + " for (var i = 0; i < extensions.length; ++i) {\n"
565 + " extensions[i](vm);\n"
567 + " vm['registerResource'] = null;\n"
568 + " var knownExtensions = extensions.length;\n"
569 + " var loader = {};\n"
570 + " var loadBytes = function(name, skip) {\n"
571 + " skip = typeof skip == 'number' ? skip : 0;\n"
572 + " var arr = resources[name];\n"
574 + " var arrSize = arr.length;\n"
575 + " if (skip < arrSize) return arr[skip];\n"
576 + " skip -= arrSize;\n"
578 + " var arrSize = 0;\n"
580 + " for (var i = 0; i < args.length; i++) {\n"
581 + " var at = args[i];\n"
582 + " if(!at) continue;\n"
584 + " if (typeof at === 'string' && at.substring(at.length - 3) === '.js') {\n"
585 + " loadExtension(at);\n"
586 + " args[i] = null;\n"
587 + " } else if (typeof at === 'function') ret = at(name, skip);\n"
589 + " var cp = vm['org_apidesign_vm4brwsr_ClassPath'];\n"
590 + " if (!cp) throw 'Core Java library not registered. Cannot load from ' + at;\n"
591 + " ret = cp(false).\n"
592 + " loadBytes___3BLjava_lang_String_2Ljava_lang_Object_2II(name, args, i, skip);\n"
594 + " if (ret) return ret;\n"
596 + " while (knownExtensions < extensions.length) {\n"
597 + " vm['registerResource'] = registerResource;\n"
598 + " extensions[knownExtensions++](vm);\n"
599 + " vm['registerResource'] = null;\n"
602 + " var arr = resources[name];\n"
603 + " return (arr && arr.length > arrSize) ? arr[arrSize] : null;\n"
605 + " var reload = function(name, arr, keep) {\n"
606 + " if (!arr) throw 'Cannot find ' + name;\n"
607 + " var lazy = vm['org_apidesign_vm4brwsr_VMLazy'];\n"
608 + " if (!lazy) throw 'No bck2brwsr VM module to compile ' + name;\n"
610 + " var attr = mangleClass(name);\n"
611 + " delete vm[attr];\n"
613 + " return lazy(false)\n"
614 + " ['load__Ljava_lang_Object_2Ljava_lang_Object_2Ljava_lang_String_2_3Ljava_lang_Object_2_3B']\n"
615 + " (vm, name, args, arr);\n"
617 + " var loadClass = function(name) {\n"
618 + " var attr = mangleClass(name);\n"
619 + " var fn = vm[attr];\n"
620 + " if (fn) return fn(false);\n"
622 + " var arr = loadBytes(replaceAll(name, '.', '/') + '.class');\n"
623 + " return reload(name, arr, true);\n"
624 + " } catch (err) {\n"
625 + " fn = vm[attr];\n"
626 + " if (fn) return fn(false);\n"
630 + " if (vm['loadClass']) {\n"
631 + " throw 'Cannot initialize the bck2brwsr VM twice!';\n"
633 + " vm['loadClass'] = loadClass;\n"
634 + " vm['_reload'] = reload;\n"
635 + " vm['loadBytes'] = loadBytes;\n"
637 + " loader.loadClass = function(name) {\n"
638 + " if (pending.length === 0) {\n"
640 + " var c = loadClass(name);\n"
641 + " c['invoke'] = function() {\n"
642 + " return invokeMethod(vm, name, arguments);\n"
645 + " } catch (err) {\n"
646 + " if (pending.length === 0) throw err;\n"
649 + " pendingClasses.push(vm);\n"
650 + " pendingClasses.push(name);\n"
651 + " pendingClasses.push(null);\n"
653 + " 'invoke' : function() {\n"
654 + " if (pending.length === 0) {\n"
655 + " invokeMethod(vm, name, arguments);\n"
658 + " pendingClasses.push(vm);\n"
659 + " pendingClasses.push(name);\n"
660 + " pendingClasses.push(arguments);\n"
664 + " return loader;\n"
667 " global.bck2brwsr.register = function(config, extension) {\n"
668 + " if (!config || config['magic'] !== 'kafíčko') {\n"
669 + " console.log('Will not register: ' + extension);\n"
672 + " var cs = typeof document == 'undefined' ? null : document['currentScript'];\n"
673 + " var prefix = cs ? cs['src']['replace'](/\\/[^\\/]*$/,'/') : '';\n"
674 + " extensions.push(extension);\n"
675 + " var cp = config['classpath'];\n"
676 + " if (cp) for (var i = 0; i < cp.length; i++) {\n"
677 + " loadExtension(prefix + cp[i]);\n"
685 protected String getExportsObject() {
690 protected boolean isExternalClass(String className) {
695 protected void lazyReference(Appendable out, String n) throws IOException {
696 String cls = n.replace('/', '_');
697 String dot = n.replace('/', '.');
699 out.append("\nvm.").append(cls).append(" = function() {");
700 out.append("\n var instance = arguments.length == 0 || arguments[0] === true;");
701 out.append("\n delete vm.").append(cls).append(";");
702 out.append("\n var c = vm.loadClass('").append(dot).append("');");
703 out.append("\n return vm.").append(cls).append("(instance);");
708 protected void requireResource(String resourcePath) throws IOException {
709 requireResourceImpl(resourcePath);
710 super.asBinary.remove(resourcePath);
714 private static final class Extension extends VM {
715 private final StringArray extensionClasses;
716 private final StringArray classpath;
718 private Extension(Appendable out, Bck2Brwsr.Resources resources,
719 String[] extClassesArray, StringArray explicitlyExported,
720 StringArray asBinary, StringArray classpath
721 ) throws IOException {
722 super(out, resources, explicitlyExported, asBinary);
723 this.extensionClasses = StringArray.asList(extClassesArray);
724 this.classpath = classpath;
728 protected void generatePrologue() throws IOException {
730 "bck2brwsr.register({\n"
731 + " 'magic' : 'kafíčko'"
733 if (classpath != null && classpath.toArray().length > 0) {
735 ",\n 'classpath' : [\n"
738 for (String s : classpath.toArray()) {
739 append(sep).append("'").append(s).append("'");
747 "\n}, function(exports) {\n"
748 + " var vm = {};\n");
749 append(" function link(n, assign) {\n"
750 + " return function() {\n"
751 + " var no_ = n['replace__Ljava_lang_String_2Ljava_lang_CharSequence_2Ljava_lang_CharSequence_2']"
752 + "('_', '_1').toString();\n"
753 + " var cls = no_['replace__Ljava_lang_String_2CC']"
754 + "('/', '_').toString();\n"
755 + " var dot = n['replace__Ljava_lang_String_2CC']"
756 + "('/', '.').toString();\n"
757 + " exports.loadClass(dot);\n"
758 + " assign(exports[cls]);\n"
759 + " return exports[cls](arguments);\n"
766 protected void generateEpilogue() throws IOException {
768 if (exportedCount == 0) {
769 throw new IOException("Creating library without any exported symbols is useless!");
774 protected String generateClass(String className) throws IOException {
775 if (isExternalClass(className)) {
776 final String cls = className.replace("_", "_1").replace('/', '_');
777 append("\n").append(assignClass(cls))
780 .append("', function(f) { ").append(assignClass(cls)).append(" f; });");
785 return super.generateClass(className);
789 protected String getExportsObject() {
794 protected boolean isExternalClass(String className) {
795 return !extensionClasses.contains(className);
799 protected void lazyReference(Appendable out, String n) throws IOException {
800 String cls = n.replace('/', '_');
802 out.append("\nvm.").append(cls).append(" = function() {");
803 out.append("\n var instance = arguments.length == 0 || arguments[0] === true;");
804 out.append("\n delete vm.").append(cls).append(";");
805 out.append("\n return link('").append(n).append("', function(f) { vm.");
806 out.append(cls).append(" = f;})(instance);");
811 protected void requireResource(String resourcePath) throws IOException {
812 requireResourceImpl(resourcePath);
813 super.asBinary.remove(resourcePath);