/*
* Copyright (c) 2008-2013, Matthias Mann
* Copyright (C) 2014 Zhang,Yuexiang (xfeep)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Matthias Mann 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 nginx.clojure.wave;
import nginx.clojure.SuspendExecution;
import nginx.clojure.wave.MethodDatabase.ClassEntry;
import nginx.clojure.asm.AnnotationVisitor;
import nginx.clojure.asm.ClassVisitor;
import nginx.clojure.asm.MethodVisitor;
import nginx.clojure.asm.Opcodes;
import nginx.clojure.asm.Type;
/**
* Check if a class contains suspendable methods.
* Basicly this class checks if a method is declared to throw {@link SuspendExecution}.
*
* @author Matthias Mann
*/
public class CheckInstrumentationVisitor extends ClassVisitor {
public static final String EXCEPTION_NAME = Type.getInternalName(SuspendExecution.class);
public static final String EXCEPTION_DESC = Type.getDescriptor(SuspendExecution.class);
private String className;
private ClassEntry classEntry;
private boolean hasSuspendable;
private boolean alreadyInstrumented;
public CheckInstrumentationVisitor() {
super(Opcodes.ASM4);
}
public boolean needsInstrumentation() {
return hasSuspendable;
}
ClassEntry getClassEntry() {
return classEntry;
}
public String getName() {
return className;
}
public boolean isAlreadyInstrumented() {
return alreadyInstrumented;
}
@Override
public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
this.className = name;
this.classEntry = new ClassEntry(superName, interfaces, (access & Opcodes.ACC_INTERFACE) != 0);
}
@Override
public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
if(desc.equals(InstrumentClass.ALREADY_INSTRUMENTED_NAME)) {
alreadyInstrumented = true;
classEntry.setAlreadyInstrumented(true);
}
return null;
}
@Override
public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
boolean suspendable = checkExceptions(exceptions);
if(suspendable) {
hasSuspendable = true;
// synchronized methods can't be made suspendable
if((access & Opcodes.ACC_SYNCHRONIZED) == Opcodes.ACC_SYNCHRONIZED) {
throw new UnableToInstrumentException("synchronized method", className, name, desc);
}
}
classEntry.set(name, desc, suspendable ? MethodDatabase.SUSPEND_NORMAL : MethodDatabase.SUSPEND_NONE);
return null;
}
public static boolean checkExceptions(String[] exceptions) {
if(exceptions != null) {
for(String ex : exceptions) {
if(ex.equals(EXCEPTION_NAME)) {
return true;
}
}
}
return false;
}
}