/***
* 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.apache.tapestry5.internal.plastic.asm.util;
import org.apache.tapestry5.internal.plastic.asm.Opcodes;
import org.apache.tapestry5.internal.plastic.asm.signature.SignatureVisitor;
/**
* A {@link SignatureVisitor} that checks that its methods are properly used.
*
* @author Eric Bruneton
*/
public class CheckSignatureAdapter extends SignatureVisitor {
/**
* Type to be used to check class signatures. See
* {@link #CheckSignatureAdapter(int, SignatureVisitor)
* CheckSignatureAdapter}.
*/
public static final int CLASS_SIGNATURE = 0;
/**
* Type to be used to check method signatures. See
* {@link #CheckSignatureAdapter(int, SignatureVisitor)
* CheckSignatureAdapter}.
*/
public static final int METHOD_SIGNATURE = 1;
/**
* Type to be used to check type signatures.See
* {@link #CheckSignatureAdapter(int, SignatureVisitor)
* CheckSignatureAdapter}.
*/
public static final int TYPE_SIGNATURE = 2;
private static final int EMPTY = 1;
private static final int FORMAL = 2;
private static final int BOUND = 4;
private static final int SUPER = 8;
private static final int PARAM = 16;
private static final int RETURN = 32;
private static final int SIMPLE_TYPE = 64;
private static final int CLASS_TYPE = 128;
private static final int END = 256;
/**
* Type of the signature to be checked.
*/
private final int type;
/**
* State of the automaton used to check the order of method calls.
*/
private int state;
/**
* <tt>true</tt> if the checked type signature can be 'V'.
*/
private boolean canBeVoid;
/**
* The visitor to which this adapter must delegate calls. May be
* <tt>null</tt>.
*/
private final SignatureVisitor sv;
/**
* Creates a new {@link CheckSignatureAdapter} object. <i>Subclasses must
* not use this constructor</i>. Instead, they must use the
* {@link #CheckSignatureAdapter(int, int, SignatureVisitor)} version.
*
* @param type
* the type of signature to be checked. See
* {@link #CLASS_SIGNATURE}, {@link #METHOD_SIGNATURE} and
* {@link #TYPE_SIGNATURE}.
* @param sv
* the visitor to which this adapter must delegate calls. May be
* <tt>null</tt>.
*/
public CheckSignatureAdapter(final int type, final SignatureVisitor sv) {
this(Opcodes.ASM5, type, sv);
}
/**
* Creates a new {@link CheckSignatureAdapter} object.
*
* @param api
* the ASM API version implemented by this visitor. Must be one
* of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
* @param type
* the type of signature to be checked. See
* {@link #CLASS_SIGNATURE}, {@link #METHOD_SIGNATURE} and
* {@link #TYPE_SIGNATURE}.
* @param sv
* the visitor to which this adapter must delegate calls. May be
* <tt>null</tt>.
*/
protected CheckSignatureAdapter(final int api, final int type,
final SignatureVisitor sv) {
super(api);
this.type = type;
this.state = EMPTY;
this.sv = sv;
}
// class and method signatures
@Override
public void visitFormalTypeParameter(final String name) {
if (type == TYPE_SIGNATURE
|| (state != EMPTY && state != FORMAL && state != BOUND)) {
throw new IllegalStateException();
}
CheckMethodAdapter.checkIdentifier(name, "formal type parameter");
state = FORMAL;
if (sv != null) {
sv.visitFormalTypeParameter(name);
}
}
@Override
public SignatureVisitor visitClassBound() {
if (state != FORMAL) {
throw new IllegalStateException();
}
state = BOUND;
SignatureVisitor v = sv == null ? null : sv.visitClassBound();
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
@Override
public SignatureVisitor visitInterfaceBound() {
if (state != FORMAL && state != BOUND) {
throw new IllegalArgumentException();
}
SignatureVisitor v = sv == null ? null : sv.visitInterfaceBound();
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
// class signatures
@Override
public SignatureVisitor visitSuperclass() {
if (type != CLASS_SIGNATURE || (state & (EMPTY | FORMAL | BOUND)) == 0) {
throw new IllegalArgumentException();
}
state = SUPER;
SignatureVisitor v = sv == null ? null : sv.visitSuperclass();
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
@Override
public SignatureVisitor visitInterface() {
if (state != SUPER) {
throw new IllegalStateException();
}
SignatureVisitor v = sv == null ? null : sv.visitInterface();
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
// method signatures
@Override
public SignatureVisitor visitParameterType() {
if (type != METHOD_SIGNATURE
|| (state & (EMPTY | FORMAL | BOUND | PARAM)) == 0) {
throw new IllegalArgumentException();
}
state = PARAM;
SignatureVisitor v = sv == null ? null : sv.visitParameterType();
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
@Override
public SignatureVisitor visitReturnType() {
if (type != METHOD_SIGNATURE
|| (state & (EMPTY | FORMAL | BOUND | PARAM)) == 0) {
throw new IllegalArgumentException();
}
state = RETURN;
SignatureVisitor v = sv == null ? null : sv.visitReturnType();
CheckSignatureAdapter cv = new CheckSignatureAdapter(TYPE_SIGNATURE, v);
cv.canBeVoid = true;
return cv;
}
@Override
public SignatureVisitor visitExceptionType() {
if (state != RETURN) {
throw new IllegalStateException();
}
SignatureVisitor v = sv == null ? null : sv.visitExceptionType();
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
// type signatures
@Override
public void visitBaseType(final char descriptor) {
if (type != TYPE_SIGNATURE || state != EMPTY) {
throw new IllegalStateException();
}
if (descriptor == 'V') {
if (!canBeVoid) {
throw new IllegalArgumentException();
}
} else {
if ("ZCBSIFJD".indexOf(descriptor) == -1) {
throw new IllegalArgumentException();
}
}
state = SIMPLE_TYPE;
if (sv != null) {
sv.visitBaseType(descriptor);
}
}
@Override
public void visitTypeVariable(final String name) {
if (type != TYPE_SIGNATURE || state != EMPTY) {
throw new IllegalStateException();
}
CheckMethodAdapter.checkIdentifier(name, "type variable");
state = SIMPLE_TYPE;
if (sv != null) {
sv.visitTypeVariable(name);
}
}
@Override
public SignatureVisitor visitArrayType() {
if (type != TYPE_SIGNATURE || state != EMPTY) {
throw new IllegalStateException();
}
state = SIMPLE_TYPE;
SignatureVisitor v = sv == null ? null : sv.visitArrayType();
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
@Override
public void visitClassType(final String name) {
if (type != TYPE_SIGNATURE || state != EMPTY) {
throw new IllegalStateException();
}
CheckMethodAdapter.checkInternalName(name, "class name");
state = CLASS_TYPE;
if (sv != null) {
sv.visitClassType(name);
}
}
@Override
public void visitInnerClassType(final String name) {
if (state != CLASS_TYPE) {
throw new IllegalStateException();
}
CheckMethodAdapter.checkIdentifier(name, "inner class name");
if (sv != null) {
sv.visitInnerClassType(name);
}
}
@Override
public void visitTypeArgument() {
if (state != CLASS_TYPE) {
throw new IllegalStateException();
}
if (sv != null) {
sv.visitTypeArgument();
}
}
@Override
public SignatureVisitor visitTypeArgument(final char wildcard) {
if (state != CLASS_TYPE) {
throw new IllegalStateException();
}
if ("+-=".indexOf(wildcard) == -1) {
throw new IllegalArgumentException();
}
SignatureVisitor v = sv == null ? null : sv.visitTypeArgument(wildcard);
return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
}
@Override
public void visitEnd() {
if (state != CLASS_TYPE) {
throw new IllegalStateException();
}
state = END;
if (sv != null) {
sv.visitEnd();
}
}
}