org.objectweb.asm.signature.SignatureWriter Maven / Gradle / Ivy
/***
* ASM: a very small and fast Java bytecode manipulation framework
* Copyright (c) 2000-2011 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 org.objectweb.asm.signature;
import org.objectweb.asm.Opcodes;
/**
* A signature visitor that generates signatures in string format.
*
* @author Thomas Hallgren
* @author Eric Bruneton
*/
public class SignatureWriter extends SignatureVisitor {
/**
* Builder used to construct the signature.
*/
private final StringBuilder buf = new StringBuilder();
/**
* Indicates if the signature contains formal type parameters.
*/
private boolean hasFormals;
/**
* Indicates if the signature contains method parameter types.
*/
private boolean hasParameters;
/**
* Stack used to keep track of class types that have arguments. Each element
* of this stack is a boolean encoded in one bit. The top of the stack is
* the lowest order bit. Pushing false = *2, pushing true = *2+1, popping =
* /2.
*/
private int argumentStack;
/**
* Constructs a new {@link SignatureWriter} object.
*/
public SignatureWriter() {
super(Opcodes.ASM6);
}
// ------------------------------------------------------------------------
// Implementation of the SignatureVisitor interface
// ------------------------------------------------------------------------
@Override
public void visitFormalTypeParameter(final String name) {
if (!hasFormals) {
hasFormals = true;
buf.append('<');
}
buf.append(name);
buf.append(':');
}
@Override
public SignatureVisitor visitClassBound() {
return this;
}
@Override
public SignatureVisitor visitInterfaceBound() {
buf.append(':');
return this;
}
@Override
public SignatureVisitor visitSuperclass() {
endFormals();
return this;
}
@Override
public SignatureVisitor visitInterface() {
return this;
}
@Override
public SignatureVisitor visitParameterType() {
endFormals();
if (!hasParameters) {
hasParameters = true;
buf.append('(');
}
return this;
}
@Override
public SignatureVisitor visitReturnType() {
endFormals();
if (!hasParameters) {
buf.append('(');
}
buf.append(')');
return this;
}
@Override
public SignatureVisitor visitExceptionType() {
buf.append('^');
return this;
}
@Override
public void visitBaseType(final char descriptor) {
buf.append(descriptor);
}
@Override
public void visitTypeVariable(final String name) {
buf.append('T');
buf.append(name);
buf.append(';');
}
@Override
public SignatureVisitor visitArrayType() {
buf.append('[');
return this;
}
@Override
public void visitClassType(final String name) {
buf.append('L');
buf.append(name);
argumentStack *= 2;
}
@Override
public void visitInnerClassType(final String name) {
endArguments();
buf.append('.');
buf.append(name);
argumentStack *= 2;
}
@Override
public void visitTypeArgument() {
if (argumentStack % 2 == 0) {
++argumentStack;
buf.append('<');
}
buf.append('*');
}
@Override
public SignatureVisitor visitTypeArgument(final char wildcard) {
if (argumentStack % 2 == 0) {
++argumentStack;
buf.append('<');
}
if (wildcard != '=') {
buf.append(wildcard);
}
return this;
}
@Override
public void visitEnd() {
endArguments();
buf.append(';');
}
/**
* Returns the signature that was built by this signature writer.
*
* @return the signature that was built by this signature writer.
*/
@Override
public String toString() {
return buf.toString();
}
// ------------------------------------------------------------------------
// Utility methods
// ------------------------------------------------------------------------
/**
* Ends the formal type parameters section of the signature.
*/
private void endFormals() {
if (hasFormals) {
hasFormals = false;
buf.append('>');
}
}
/**
* Ends the type arguments of a class or inner class type.
*/
private void endArguments() {
if (argumentStack % 2 != 0) {
buf.append('>');
}
argumentStack /= 2;
}
}