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 boolean addThree = false;
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()
84 if (config.includeVM()) {
85 fixedNames.add(VM.class.getName().replace('.', '/'));
88 vm = new Standalone(out,
89 config.getResources(), config.exported(),
94 fixedNames.add(Object.class.getName().replace('.', '/'));
95 fixedNames.add(Class.class.getName().replace('.', '/'));
96 fixedNames.add(ArithmeticException.class.getName().replace('.', '/'));
98 vm.doCompile(fixedNames.addAndNew(both));
101 private void doCompile(StringArray names) throws IOException {
103 append("\n var invoker = {};");
104 append("\n function registerClass(vm, name, fn) {");
105 append("\n if (!vm[name]) vm[name] = fn;");
106 append("\n return vm[name];");
109 append(invokerMethods);
111 for (String r : asBinary.toArray()) {
112 append("\n ").append(getExportsObject()).append("['registerResource']('");
113 append(r).append("', '");
114 InputStream is = this.resources.get(r);
115 int avail = is.available();
119 byte[] arr = new byte[avail];
122 if (offset == arr.length) {
123 byte[] tmp = new byte[arr.length * 2];
124 System.arraycopy(arr, 0, tmp, 0, arr.length);
127 int len = is.read(arr, offset, arr.length - offset);
133 if (offset != arr.length) {
134 byte[] tmp = new byte[offset];
135 System.arraycopy(arr, 0, tmp, 0, offset);
146 @JavaScriptBody(args = { "arr" }, body = "return btoa(arr);")
147 private static String btoa(byte[] arr) {
148 return javax.xml.bind.DatatypeConverter.printBase64Binary(arr);
151 protected abstract void generatePrologue() throws IOException;
153 protected abstract void generateEpilogue() throws IOException;
155 protected abstract String getExportsObject();
157 protected abstract boolean isExternalClass(String className);
159 protected abstract void lazyReference(Appendable out, String n) throws IOException;
162 protected final void declareClass(ClassData classData, String mangledName)
164 if (exportedSymbols.isExported(classData)) {
165 append("registerClass(").append(getExportsObject()).append(",'")
176 protected String generateClass(String className) throws IOException {
177 ClassData classData = classDataCache.getClassData(className);
178 if (classData == null) {
179 throw new IOException("Can't find class " + className);
181 return compile(classData);
185 protected void declaredField(FieldData fieldData,
187 String mangledName) throws IOException {
188 if (exportedSymbols.isExported(fieldData)) {
189 exportMember(destObject, mangledName);
194 protected void declaredMethod(MethodData methodData,
196 String mangledName) throws IOException {
197 if (isHierarchyExported(methodData)) {
198 exportMember(destObject, mangledName);
202 private void exportMember(String destObject, String memberName)
204 append("\n").append(destObject).append("['")
206 .append("'] = m;\n");
209 private void generateBody(StringArray names) throws IOException {
210 StringArray processed = new StringArray();
211 StringArray initCode = new StringArray();
212 StringArray skipClass = new StringArray();
213 for (String baseClass : names.toArray()) {
214 references.add(baseClass);
217 for (String n : references.toArray()) {
218 if (skipClass.contains(n)) {
221 if (processed.contains(n)) {
229 InputStream is = resources.get(name + ".class");
231 lazyReference(this, name);
236 String ic = generateClass(name);
238 initCode.add(ic == null ? "" : ic);
239 } catch (RuntimeException ex) {
240 throw new IOException("Error while compiling " + name + "\n", ex);
244 for (String resource : scripts.toArray()) {
245 while (resource.startsWith("/")) {
246 resource = resource.substring(1);
248 requireResourceImpl(false, resource);
249 asBinary.remove(resource);
251 scripts = new StringArray();
253 StringArray toInit = StringArray.asList(references.toArray());
256 for (String ic : toInit.toArray()) {
257 int indx = processed.indexOf(ic);
259 final String theCode = initCode.toArray()[indx];
260 if (!theCode.isEmpty()) {
261 append(theCode).append("\n");
263 initCode.toArray()[indx] = "";
269 final void requireResourceImpl(boolean useEval, String resource) throws IOException {
270 InputStream emul = resources.get(resource);
272 throw new IOException("Can't find " + resource);
274 append("\n// resource from ").append(resource).append("\n");
277 append("(0 || eval)(\"");
279 readResource(useEval, emul, this);
286 private static void readResource(boolean escape, InputStream emul, Appendable out) throws IOException {
289 int ch = emul.read();
293 if (ch < 0 || ch > 255) {
294 throw new IOException("Invalid char in emulation " + ch);
305 out.append("\\n\"\n + \"");
314 out.append((char)ch);
317 out.append((char)ch);
325 static String toString(String name) throws IOException {
326 StringBuilder sb = new StringBuilder();
327 // compile(sb, name);
328 return sb.toString().toString();
331 private StringArray scripts = new StringArray();
332 private StringArray references = new StringArray();
335 protected boolean requireReference(String cn) {
336 return references.addIfMissing(cn);
340 protected void requireScript(String resourcePath) {
341 scripts.add(resourcePath);
345 String assignClass(String className) {
346 return "vm." + className + " = ";
350 String accessClass(String className) {
351 return "vm." + className;
355 protected FieldData findField(String[] fieldInfoName) throws IOException {
356 FieldData field = classDataCache.findField(
357 fieldInfoName[0], fieldInfoName[1], fieldInfoName[2]
359 return field != null && canAccessDirectly(field.cls) ? field : null;
363 protected String accessField(String object, FieldData field, String[] fieldInfoName)
365 if (field != null && !field.isStatic()) {
366 return "fld_" + object + "_" + field.getName();
368 String mangledName = "_" + fieldInfoName[1];
369 return accessNonVirtualMember(
370 object, mangledName, field != null ? field.cls : null
376 protected String accessStaticMethod(
379 String[] fieldInfoName) throws IOException {
380 final MethodData method =
381 classDataCache.findMethod(fieldInfoName[0],
384 return accessNonVirtualMember(object, mangledName,
385 (method != null) ? method.cls : null);
389 protected String accessVirtualMethod(
392 String[] fieldInfoName,
394 ) throws IOException {
395 final ClassData referencedClass =
396 classDataCache.getClassData(fieldInfoName[0]);
397 final MethodData method =
398 classDataCache.findMethod(referencedClass,
403 && !isExternalClass(method.cls.getClassName())
404 && (((method.access & ByteCodeParser.ACC_FINAL) != 0)
405 || ((referencedClass.getAccessFlags()
406 & ByteCodeParser.ACC_FINAL) != 0)
407 || !isHierarchyExported(method))) {
408 return object + "." + mangledName + '(';
411 return accessThroughInvoker(object, mangledName, params);
414 private String accessThroughInvoker(String object, String mangledName, int params)
416 String def = "\n invoker." + mangledName + " = function(target";
417 if (invokerMethods.indexOf(def) == -1) {
418 invokerMethods.append(def);
419 for (int j = 0; j < params; j++) {
420 invokerMethods.append(", p").append(j);
422 invokerMethods.append(") {\n return target['").
423 append(mangledName).append("'](");
424 for (int j = 0; j < params; j++) {
426 invokerMethods.append(",");
428 invokerMethods.append("p").append(j);
430 invokerMethods.append(");\n };");
432 return "invoker." + mangledName + '(' + object + (params > 1 ? "," : "");
435 private boolean isHierarchyExported(final MethodData methodData)
437 if (exportedSymbols.isExported(methodData)) {
440 if ((methodData.access & (ByteCodeParser.ACC_PRIVATE
441 | ByteCodeParser.ACC_STATIC)) != 0) {
445 final ExportedMethodFinder exportedMethodFinder =
446 new ExportedMethodFinder(exportedSymbols);
448 classDataCache.findMethods(
450 methodData.getName(),
451 methodData.getInternalSig(),
452 exportedMethodFinder);
454 return (exportedMethodFinder.getFound() != null);
457 private boolean canAccessDirectly(ClassData declaringClass) {
458 if (declaringClass == null) {
461 final String className = declaringClass.getClassName();
463 "java/lang/Object".equals(className) ||
464 "java/lang/reflect/Array".equals(className) ||
465 isExternalClass(className)
472 private String accessNonVirtualMember(
473 String object, String mangledName, ClassData declaringClass
475 return canAccessDirectly(declaringClass) ?
476 object + "." + mangledName :
477 object + "['" + mangledName + "']";
480 private final class ExportedMethodFinder
481 implements ClassDataCache.TraversalCallback<MethodData> {
482 private final ExportedSymbols exportedSymbols;
483 private MethodData found;
485 public ExportedMethodFinder(final ExportedSymbols exportedSymbols) {
486 this.exportedSymbols = exportedSymbols;
490 public boolean traverse(final MethodData methodData) {
493 exportedSymbols.isExported(methodData) ||
494 isExternalClass(methodData.cls.getClassName())
499 } catch (final IOException e) {
505 public MethodData getFound() {
510 private static final class Standalone extends VM {
511 private Standalone(Appendable out,
512 Bck2Brwsr.Resources resources,
513 StringArray explicitlyExported, StringArray asBinary
515 super(out, resources, explicitlyExported, asBinary);
519 protected void generatePrologue() throws IOException {
520 append("(function VM(global) {var fillInVMSkeleton = function(vm) {");
524 protected void generateEpilogue() throws IOException {
528 + " var extensions = [];\n"
529 + " function replaceAll(s, target, replacement) {\n"
532 + " var indx = s.indexOf(target, pos);\n"
533 + " if (indx === -1) {\n"
536 + " pos = indx + replacement.length;\n"
537 + " s = s.substring(0, indx) + replacement + s.substring(indx + target.length);\n"
540 + " function mangleClass(name) {\n"
541 + " name = replaceAll(name, '_', '_1');\n"
542 + " name = replaceAll(name, '.', '_');\n"
545 + " var pending = [];\n"
546 + " var pendingClasses = [];\n"
547 + " function extensionLoaded(ev) {\n"
548 + " var at = pending.indexOf(ev.target);\n"
549 + " pending.splice(at, 1);\n"
550 + " if (pending.length === 0) {\n"
551 + " for (var i = 0; i < pendingClasses.length; i += 3) {\n"
552 + " invokeMethod(pendingClasses[i], pendingClasses[i + 1], pendingClasses[i + 2]);\n"
554 + " pendingClasses = [];\n"
557 + " function invokeMethod(vm, n, args) {\n"
558 + " var clazz = vm.loadClass(n);\n"
560 + " var seek = args[0];\n"
561 + " var prefix = seek.indexOf('__') == -1 ? seek + '__' : seek;\n"
562 + " args = Array.prototype.slice.call(args, 1);\n"
563 + " var found = '';\n"
564 + " for (var m in clazz) {\n"
565 + " if (m.indexOf(prefix) === 0) {\n"
566 + " return clazz[m].apply(null, args);\n"
568 + " found += m.toString() + '\\n'\n"
570 + " throw 'Cannot find ' + seek + ' in ' + n + ' found:\\n' + found;\n"
573 + " function extensionError(ev) {\n"
574 + " console.log('error loading ' + ev.target.src);\n"
575 + " extensionLoaded(ev);\n"
577 + " function loadExtension(url) {\n"
578 + " if (url.substring(url.length - 4) == '.jar')\n"
579 + " url = url.substring(0, url.length - 4) + '.js';\n"
580 + " var script = document.createElement('script');\n"
581 + " script.type = 'text/javascript';\n"
582 + " script.src = url;\n"
583 + " script.onload = extensionLoaded;\n"
584 + " script.onerror = extensionError;\n"
585 + " document.getElementsByTagName('head')[0].appendChild(script);\n"
586 + " pending.push(script);\n"
588 + " global.bck2brwsr = function() {\n"
589 + " var args = Array.prototype.slice.apply(arguments);\n"
590 + " var resources = {};\n"
591 + " function registerResource(n, a64) {\n"
592 + " var frm = atob || window.atob;\n"
593 + " var str = frm(a64);\n"
595 + " for (var i = 0; i < str.length; i++) {\n"
596 + " var ch = str.charCodeAt(i) & 0xff;\n"
597 + " if (ch > 127) ch -= 256;\n"
600 + " if (!resources[n]) resources[n] = [arr];\n"
601 + " else resources[n].push(arr);\n"
603 + " var vm = fillInVMSkeleton({ 'registerResource' : registerResource });\n"
604 + " function initVM() {\n"
605 + " var clsArray = vm['java_lang_reflect_Array'];\n"
606 + " if (clsArray) clsArray(false);\n"
608 + " for (var i = 0; i < extensions.length; ++i) {\n"
609 + " extensions[i](vm);\n"
611 + " vm['registerResource'] = null;\n"
612 + " var knownExtensions = extensions.length;\n"
613 + " var loader = {};\n"
614 + " var classPath;\n"
615 + " var loadBytes = function(name, skip) {\n"
616 + " skip = typeof skip == 'number' ? skip : 0;\n"
617 + " var arr = resources[name];\n"
619 + " var arrSize = arr.length;\n"
620 + " if (skip < arrSize) return arr[skip];\n"
621 + " skip -= arrSize;\n"
623 + " var arrSize = 0;\n"
625 + " for (var i = 0; i < args.length; i++) {\n"
626 + " var at = args[i];\n"
627 + " if(!at) continue;\n"
629 + " if (typeof at === 'string' && at.substring(at.length - 3) === '.js') {\n"
630 + " loadExtension(at);\n"
631 + " args[i] = null;\n"
632 + " } else if (typeof at === 'function') ret = at(name, skip);\n"
634 + " if (classPath === undefined) {\n"
635 + " classPath = null;\n"
637 + " classPath = vm.loadClass('org.apidesign.vm4brwsr.ClassPath');\n"
638 + " } catch (err) {\n"
641 + " if (!classPath) {\n"
642 + " if (name !== 'org/apidesign/vm4brwsr/ClassPath.class') {\n"
643 + " throw 'Core Java library not registered. Cannot load from ' + at;\n"
647 + " ret = classPath['loadBytes___3BLjava_lang_String_2Ljava_lang_Object_2II'](name, args, i, skip);\n"
650 + " if (ret) return ret;\n"
652 + " while (knownExtensions < extensions.length) {\n"
653 + " vm['registerResource'] = registerResource;\n"
654 + " extensions[knownExtensions++](vm);\n"
655 + " vm['registerResource'] = null;\n"
658 + " var arr = resources[name];\n"
659 + " return (arr && arr.length > arrSize) ? arr[arrSize] : null;\n"
661 + " var reload = function(name, arr, keep) {\n"
662 + " if (!arr) throw 'Cannot find ' + name;\n"
663 + " var err = null;\n"
665 + " var lazy = loadClass('org.apidesign.vm4brwsr.VMLazy');\n"
670 + " throw 'No bck2brwsr VM module to compile ' + name + ':\\n' + err;\n"
673 + " var attr = mangleClass(name);\n"
674 + " delete vm[attr];\n"
676 + " return lazy['load__Ljava_lang_Object_2Ljava_lang_Object_2Ljava_lang_String_2_3Ljava_lang_Object_2_3B']\n"
677 + " (vm, name, args, arr);\n"
679 + " var loadClass = function(name) {\n"
680 + " var attr = mangleClass(name);\n"
681 + " var fn = vm[attr];\n"
682 + " if (fn) return fn(false);\n"
684 + " var arr = loadBytes(replaceAll(name, '.', '/') + '.class');\n"
685 + " return reload(name, arr, true);\n"
686 + " } catch (err) {\n"
687 + " fn = vm[attr];\n"
688 + " if (fn) return fn(false);\n"
692 + " if (vm['loadClass']) {\n"
693 + " throw 'Cannot initialize the bck2brwsr VM twice!';\n"
695 + " vm['loadClass'] = loadClass;\n"
696 + " vm['_reload'] = reload;\n"
697 + " vm['loadBytes'] = loadBytes;\n"
699 + " loader.loadClass = function(name) {\n"
700 + " if (pending.length === 0) {\n"
702 + " var c = loadClass(name);\n"
703 + " c['invoke'] = function() {\n"
704 + " return invokeMethod(vm, name, arguments);\n"
707 + " } catch (err) {\n"
708 + " if (pending.length === 0) throw err;\n"
711 + " pendingClasses.push(vm);\n"
712 + " pendingClasses.push(name);\n"
713 + " pendingClasses.push(null);\n"
715 + " 'invoke' : function() {\n"
716 + " if (pending.length === 0) {\n"
717 + " invokeMethod(vm, name, arguments);\n"
720 + " pendingClasses.push(vm);\n"
721 + " pendingClasses.push(name);\n"
722 + " pendingClasses.push(arguments);\n"
726 + " return loader;\n"
729 " global.bck2brwsr.register = function(config, extension) {\n"
730 + " if (!config || config['magic'] !== 'kafčo') {\n"
731 + " console.log('Will not register: ' + extension);\n"
734 + " var cs = typeof document == 'undefined' ? null : document['currentScript'];\n"
735 + " var csUrl = cs ? cs['src'] : null;\n"
736 + " var prefix = csUrl ? csUrl['replace'](/\\/[^\\/]*$/,'/') : '';\n"
737 + " extensions.push(extension);\n"
738 + " var cp = config['classpath'];\n"
739 + " if (cp) for (var i = 0; i < cp.length; i++) {\n"
740 + " loadExtension(prefix + cp[i]);\n"
748 protected String getExportsObject() {
753 protected boolean isExternalClass(String className) {
758 protected void lazyReference(Appendable out, String n) throws IOException {
759 String cls = n.replace('/', '_');
760 String dot = n.replace('/', '.');
762 out.append("\nvm.").append(cls).append(" = function() {");
763 out.append("\n var instance = arguments.length == 0 || arguments[0] === true;");
764 out.append("\n delete vm.").append(cls).append(";");
765 out.append("\n var c = vm.loadClass('").append(dot).append("');");
766 out.append("\n return vm.").append(cls).append("(instance);");
771 protected void requireResource(String resourcePath) throws IOException {
772 requireResourceImpl(true, resourcePath);
773 super.asBinary.remove(resourcePath);
777 private static final class Extension extends VM {
778 private final StringArray extensionClasses;
779 private final StringArray classpath;
781 private Extension(Appendable out, Bck2Brwsr.Resources resources,
782 String[] extClassesArray, StringArray explicitlyExported,
783 StringArray asBinary, StringArray classpath
784 ) throws IOException {
785 super(out, resources, explicitlyExported, asBinary);
786 this.extensionClasses = StringArray.asList(extClassesArray);
787 this.classpath = classpath;
791 protected void generatePrologue() throws IOException {
793 "bck2brwsr.register({\n"
794 + " 'magic' : 'kafčo'"
796 if (classpath != null && classpath.toArray().length > 0) {
798 ",\n 'classpath' : [\n"
801 for (String s : classpath.toArray()) {
802 append(sep).append("'").append(s).append("'");
810 "\n}, function(exports) {\n"
811 + " var vm = {};\n");
812 append(" function link(n, assign) {\n"
813 + " function replaceAll(s, o, n) {\n"
816 + " var indx = s.indexOf(o, pos);\n"
817 + " if (indx === -1) {\n"
820 + " pos = indx + n.length;\n"
821 + " s = s.substring(0, indx) + n + s.substring(indx + o.length);\n"
824 + " return function() {\n"
825 + " var no_ = replaceAll(n, '_', '_1');\n"
826 + " var cls = replaceAll(no_, '/', '_');\n"
827 + " var dot = replaceAll(n, '/', '.');\n"
828 + " exports.loadClass(dot);\n"
829 + " assign(exports[cls]);\n"
830 + " return exports[cls](arguments);\n"
837 protected void generateEpilogue() throws IOException {
839 if (exportedCount == 0) {
840 throw new IOException("Creating library without any exported symbols is useless!");
845 String accessClass(String className) {
846 if (this.extensionClasses.contains(className.replace('_', '/'))) {
849 return super.accessClass(className);
853 protected String generateClass(String className) throws IOException {
854 if (isExternalClass(className)) {
855 final String cls = className.replace("_", "_1").replace('/', '_');
856 append("\n").append(assignClass(cls))
859 .append("', function(f) { ").append(assignClass(cls)).append(" f; });");
864 return super.generateClass(className);
868 protected String getExportsObject() {
873 protected boolean isExternalClass(String className) {
874 return !extensionClasses.contains(className);
878 protected void lazyReference(Appendable out, String n) throws IOException {
879 String cls = n.replace('/', '_');
881 out.append("\nvm.").append(cls).append(" = function() {");
882 out.append("\n var instance = arguments.length == 0 || arguments[0] === true;");
883 out.append("\n delete vm.").append(cls).append(";");
884 out.append("\n return link('").append(n).append("', function(f) { vm.");
885 out.append(cls).append(" = f;})(instance);");
890 protected void requireResource(String resourcePath) throws IOException {
891 requireResourceImpl(true, resourcePath);
892 super.asBinary.remove(resourcePath);