Java tutorial
/*** * ASM: a very small and fast Java bytecode manipulation framework * Copyright (c) 2000-2007 INRIA, France Telecom * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ package com.google.gwt.dev.asm.signature; /** * A type signature parser to make a signature visitor visit an existing * signature. * * @author Thomas Hallgren * @author Eric Bruneton */ public class SignatureReader { /** * The signature to be read. */ private final String signature; /** * Constructs a {@link SignatureReader} for the given signature. * * @param signature A <i>ClassSignature</i>, <i>MethodTypeSignature</i>, * or <i>FieldTypeSignature</i>. */ public SignatureReader(final String signature) { this.signature = signature; } /** * Makes the given visitor visit the signature of this * {@link SignatureReader}. This signature is the one specified in the * constructor (see {@link #SignatureReader(String) SignatureReader}). This * method is intended to be called on a {@link SignatureReader} that was * created using a <i>ClassSignature</i> (such as the * <code>signature</code> parameter of the * {@link com.google.gwt.dev.asm.ClassVisitor#visit ClassVisitor.visit} method) * or a <i>MethodTypeSignature</i> (such as the <code>signature</code> * parameter of the * {@link com.google.gwt.dev.asm.ClassVisitor#visitMethod ClassVisitor.visitMethod} * method). * * @param v the visitor that must visit this signature. */ public void accept(final SignatureVisitor v) { String signature = this.signature; int len = signature.length(); int pos; char c; if (signature.charAt(0) == '<') { pos = 2; do { int end = signature.indexOf(':', pos); v.visitFormalTypeParameter(signature.substring(pos - 1, end)); pos = end + 1; c = signature.charAt(pos); if (c == 'L' || c == '[' || c == 'T') { pos = parseType(signature, pos, v.visitClassBound()); } while ((c = signature.charAt(pos++)) == ':') { pos = parseType(signature, pos, v.visitInterfaceBound()); } } while (c != '>'); } else { pos = 0; } if (signature.charAt(pos) == '(') { pos++; while (signature.charAt(pos) != ')') { pos = parseType(signature, pos, v.visitParameterType()); } pos = parseType(signature, pos + 1, v.visitReturnType()); while (pos < len) { pos = parseType(signature, pos + 1, v.visitExceptionType()); } } else { pos = parseType(signature, pos, v.visitSuperclass()); while (pos < len) { pos = parseType(signature, pos, v.visitInterface()); } } } /** * Makes the given visitor visit the signature of this * {@link SignatureReader}. This signature is the one specified in the * constructor (see {@link #SignatureReader(String) SignatureReader}). This * method is intended to be called on a {@link SignatureReader} that was * created using a <i>FieldTypeSignature</i>, such as the * <code>signature</code> parameter of the * {@link com.google.gwt.dev.asm.ClassVisitor#visitField * ClassVisitor.visitField} or {@link * com.google.gwt.dev.asm.MethodVisitor#visitLocalVariable * MethodVisitor.visitLocalVariable} methods. * * @param v the visitor that must visit this signature. */ public void acceptType(final SignatureVisitor v) { parseType(this.signature, 0, v); } /** * Parses a field type signature and makes the given visitor visit it. * * @param signature a string containing the signature that must be parsed. * @param pos index of the first character of the signature to parsed. * @param v the visitor that must visit this signature. * @return the index of the first character after the parsed signature. */ private static int parseType(final String signature, int pos, final SignatureVisitor v) { char c; int start, end; boolean visited, inner; String name; switch (c = signature.charAt(pos++)) { case 'Z': case 'C': case 'B': case 'S': case 'I': case 'F': case 'J': case 'D': case 'V': v.visitBaseType(c); return pos; case '[': return parseType(signature, pos, v.visitArrayType()); case 'T': end = signature.indexOf(';', pos); v.visitTypeVariable(signature.substring(pos, end)); return end + 1; default: // case 'L': start = pos; visited = false; inner = false; for (;;) { switch (c = signature.charAt(pos++)) { case '.': case ';': if (!visited) { name = signature.substring(start, pos - 1); if (inner) { v.visitInnerClassType(name); } else { v.visitClassType(name); } } if (c == ';') { v.visitEnd(); return pos; } start = pos; visited = false; inner = true; break; case '<': name = signature.substring(start, pos - 1); if (inner) { v.visitInnerClassType(name); } else { v.visitClassType(name); } visited = true; top: for (;;) { switch (c = signature.charAt(pos)) { case '>': break top; case '*': ++pos; v.visitTypeArgument(); break; case '+': case '-': pos = parseType(signature, pos + 1, v.visitTypeArgument(c)); break; default: pos = parseType(signature, pos, v.visitTypeArgument('=')); break; } } } } } } }