/**
* verify that variables mentioned in this expression are actually available in the supplied
* bindings list and infer/validate the type of this expression or its subexpressions where
* possible
*
* @throws TypeException if any variable is missing or has the wrong type
*/
public void bind() throws TypeException {
// check that the recipient and argument expressions have valid bindings
if (recipient != null) {
// ok, we have a supplied recipient
recipient.bind();
} else if (pathList != null) {
// see if the path starts with a bound variable and, if so, treat the path as a series
// of field references and construct a owner expression from it.
String leading = pathList[0];
Binding binding = getBindings().lookup(leading);
if (binding != null) {
// create a sequence of field expressions and make it the recipient
int l = pathList.length;
Expression recipient = new Variable(rule, binding.getType(), token, binding.getName());
for (int idx = 1; idx < l; idx++) {
recipient =
new FieldExpression(rule, Type.UNDEFINED, token, pathList[idx], recipient, null);
}
this.recipient = recipient;
this.pathList = null;
// not strictly necessary?
this.recipient.bind();
}
}
Iterator<Expression> iterator = arguments.iterator();
while (iterator.hasNext()) {
iterator.next().bind();
}
}
private void installParameters(boolean isStatic, String className) throws TypeException {
Type type;
// add a binding for the helper so we can call builtin static methods
type = typeGroup.create(helperClass.getName());
Binding ruleBinding = bindings.lookup("$$");
if (ruleBinding != null) {
ruleBinding.setType(type);
} else {
bindings.append(new Binding(this, "$$", type));
}
if (!isStatic) {
Binding recipientBinding = bindings.lookup("$0");
if (recipientBinding != null) {
type = typeGroup.create(className);
if (type.isUndefined()) {
throw new TypeException(
"Rule.installParameters : Rule " + name + " unable to load class " + className);
}
recipientBinding.setType(type);
}
}
String returnTypeName = Type.parseMethodReturnType(triggerDescriptor);
returnType = typeGroup.create(returnTypeName);
Iterator<Binding> iterator = bindings.iterator();
while (iterator.hasNext()) {
Binding binding = iterator.next();
// these bindings are typed via the descriptor installed during trigger injection
// note that the return type has to be done this way because it may represent the
// trigger method return type or the invoke method return type
if (binding.isParam() || binding.isLocalVar() || binding.isReturn()) {
String typeName = binding.getDescriptor();
String[] typeAndArrayBounds = typeName.split("\\[");
Type baseType = typeGroup.create(typeAndArrayBounds[0]);
Type fullType = baseType;
if (baseType.isUndefined()) {
throw new TypeException(
"Rule.installParameters : Rule " + name + " unable to load class " + baseType);
}
for (int i = 1; i < typeAndArrayBounds.length; i++) {
fullType = typeGroup.createArray(fullType);
}
binding.setType(fullType);
} else if (binding.isThrowable()) {
// TODO -- enable a more precise specification of the throwable type
// we need to be able to obtain the type descriptor for the throw operation
binding.setType(typeGroup.ensureType(Throwable.class));
} else if (binding.isParamCount()) {
binding.setType(Type.I);
} else if (binding.isParamArray() || binding.isInvokeParamArray()) {
binding.setType(Type.OBJECT.arrayType());
} else if (binding.isTriggerClass() || binding.isTriggerMethod()) {
binding.setType(Type.STRING);
}
}
}
private static byte[] compileBytes(
Rule rule,
Class helperClass,
String helperName,
String compiledHelperName,
boolean compileToBytecode)
throws Exception {
ClassWriter cw = new ClassWriter(0);
FieldVisitor fv;
MethodVisitor mv;
AnnotationVisitor av0;
// create the class as a subclass of the rule helper class, appending Compiled to the front
// of the class name and a unique number to the end of the class helperName
// also ensure it implements the HelperAdapter interface
//
// public class foo.bar.Compiled_<helper>_<NNN> extends foo.bar.<helper> implements
// HelperAdapter
cw.visit(
V1_5,
ACC_PUBLIC + ACC_SUPER,
compiledHelperName,
null,
helperName,
new String[] {"org/jboss/byteman/rule/helper/HelperAdapter"});
// we need to install the source file name
{
String fullFileName = rule.getFile();
int idx = fullFileName.lastIndexOf(java.io.File.separatorChar);
String basicFileName = (idx < 0 ? fullFileName : fullFileName.substring(idx + 1));
String debug = "// compiled from: " + fullFileName + "\n// generated by Byteman\n";
cw.visitSource(basicFileName, debug);
}
{
// we need a Hashmap field to hold the bindings
//
// private HashMap<String, Object> bindingMap;
fv =
cw.visitField(
ACC_PRIVATE,
"bindingMap",
"Ljava/util/HashMap;",
"Ljava/util/HashMap<Ljava/lang/String;Ljava/lang/Object;>;",
null);
fv.visitEnd();
}
{
// and a rule field to hold the rule
//
// private Rule rule;
fv =
cw.visitField(
ACC_PRIVATE,
"rule",
"Lorg/jboss/byteman/rule/Rule;",
"Lorg/jboss/byteman/rule/Rule;",
null);
fv.visitEnd();
}
{
// we need a constructor which takes a Rule as argument
// if the helper implements a constructor which takes a Rule as argument then we invoke it
// otherwise we invoke the empty helper constructor
Constructor superConstructor = null;
try {
superConstructor = helperClass.getDeclaredConstructor(Rule.class);
} catch (NoSuchMethodException e) {
// hmm, ok see if there is an empty constructor
} catch (SecurityException e) {
throw new CompileException(
"Compiler.compileBytes : unable to access constructor for helper class "
+ helperClass.getCanonicalName());
}
boolean superWantsRule = (superConstructor != null);
if (!superWantsRule) {
try {
superConstructor = helperClass.getDeclaredConstructor();
} catch (NoSuchMethodException e) {
throw new CompileException(
"Compiler.compileBytes : no valid constructor found for helper class "
+ helperClass.getCanonicalName());
} catch (SecurityException e) {
throw new CompileException(
"Compiler.compileBytes : unable to access constructor for helper class "
+ helperClass.getCanonicalName());
}
}
//
// public Compiled<helper>_<NNN>()Rule rule)
mv = cw.visitMethod(ACC_PUBLIC, "<init>", "(Lorg/jboss/byteman/rule/Rule;)V", null, null);
mv.visitCode();
// super();
//
// or
//
// super(Rule);
if (superWantsRule) {
mv.visitVarInsn(ALOAD, 0);
mv.visitVarInsn(ALOAD, 1);
mv.visitMethodInsn(INVOKESPECIAL, helperName, "<init>", "(Lorg/jboss/byteman/rule/Rule;)V");
} else {
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, helperName, "<init>", "()V");
}
// bindingMap = new HashMap<String, Object);
mv.visitVarInsn(ALOAD, 0);
mv.visitTypeInsn(NEW, "java/util/HashMap");
mv.visitInsn(DUP);
mv.visitMethodInsn(INVOKESPECIAL, "java/util/HashMap", "<init>", "()V");
mv.visitFieldInsn(PUTFIELD, compiledHelperName, "bindingMap", "Ljava/util/HashMap;");
// this.rule = rule
mv.visitVarInsn(ALOAD, 0);
mv.visitVarInsn(ALOAD, 1);
mv.visitFieldInsn(PUTFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
// return;
mv.visitInsn(RETURN);
mv.visitMaxs(3, 2);
mv.visitEnd();
}
{
// create the execute method
//
// public void execute(Bindings bindings, Object recipient, Object[] args) throws
// ExecuteException
mv =
cw.visitMethod(
ACC_PUBLIC,
"execute",
"(Ljava/lang/Object;[Ljava/lang/Object;)V",
null,
new String[] {"org/jboss/byteman/rule/exception/ExecuteException"});
mv.visitCode();
// if (Transformer.isVerbose())
mv.visitMethodInsn(INVOKESTATIC, "org/jboss/byteman/agent/Transformer", "isVerbose", "()Z");
Label l0 = new Label();
mv.visitJumpInsn(IFEQ, l0);
// then
// System.out.println(rule.getName() + " execute");
mv.visitFieldInsn(GETSTATIC, "java/lang/System", "out", "Ljava/io/PrintStream;");
mv.visitTypeInsn(NEW, "java/lang/StringBuilder");
mv.visitInsn(DUP);
mv.visitMethodInsn(INVOKESPECIAL, "java/lang/StringBuilder", "<init>", "()V");
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitMethodInsn(
INVOKEVIRTUAL, "org/jboss/byteman/rule/Rule", "getName", "()Ljava/lang/String;");
mv.visitMethodInsn(
INVOKEVIRTUAL,
"java/lang/StringBuilder",
"append",
"(Ljava/lang/String;)Ljava/lang/StringBuilder;");
mv.visitLdcInsn(" execute()");
mv.visitMethodInsn(
INVOKEVIRTUAL,
"java/lang/StringBuilder",
"append",
"(Ljava/lang/String;)Ljava/lang/StringBuilder;");
mv.visitMethodInsn(
INVOKEVIRTUAL, "java/lang/StringBuilder", "toString", "()Ljava/lang/String;");
mv.visitMethodInsn(INVOKEVIRTUAL, "java/io/PrintStream", "println", "(Ljava/lang/String;)V");
// end if
mv.visitLabel(l0);
Bindings bindings = rule.getBindings();
Iterator<Binding> iterator = bindings.iterator();
while (iterator.hasNext()) {
Binding binding = iterator.next();
String name = binding.getName();
if (binding.isAlias()) {
// lookups and updates will use the aliased name
continue;
}
if (binding.isHelper()) {
// bindingMap.put(name, this);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "bindingMap", "Ljava/util/HashMap;");
mv.visitLdcInsn(name);
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"java/util/HashMap",
"put",
"(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
mv.visitInsn(POP);
} else if (binding.isRecipient()) {
// bindingMap.put(name, recipient);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "bindingMap", "Ljava/util/HashMap;");
mv.visitLdcInsn(name);
mv.visitVarInsn(ALOAD, 1);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"java/util/HashMap",
"put",
"(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
mv.visitInsn(POP);
// } else if (binding.isParam() || binding.isLocalVar() || binding.isReturn() ||
// binding.isThrowable() || binding.isParamCount() || binding.isParamArray())
// {
} else if (!binding.isBindVar()) {
// bindingMap.put(name, args[binding.getCallArrayIndex()]);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "bindingMap", "Ljava/util/HashMap;");
mv.visitLdcInsn(name);
mv.visitVarInsn(ALOAD, 2);
mv.visitLdcInsn(binding.getCallArrayIndex());
mv.visitInsn(AALOAD);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"java/util/HashMap",
"put",
"(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
mv.visitInsn(POP);
}
}
// execute0()
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKEVIRTUAL, compiledHelperName, "execute0", "()V");
// now restore update bindings
iterator = bindings.iterator();
while (iterator.hasNext()) {
Binding binding = iterator.next();
if (binding.isAlias()) {
continue;
}
String name = binding.getName();
if (binding.isUpdated()) {
// if (binding.isParam() || binding.isLocalVar() || binding.isReturn()) {
if (!binding.isBindVar()) {
int idx = binding.getCallArrayIndex();
// Object value = bindingMap.get(name);
// args[idx] = value;
mv.visitVarInsn(ALOAD, 2); // args
mv.visitLdcInsn(idx);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "bindingMap", "Ljava/util/HashMap;");
mv.visitLdcInsn(name);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"java/util/HashMap",
"get",
"(Ljava/lang/Object;)Ljava/lang/Object;");
mv.visitInsn(AASTORE);
}
}
}
// return
mv.visitInsn(RETURN);
mv.visitMaxs(4, 3);
mv.visitEnd();
}
{
// create the setBinding method
//
// public void setBinding(String name, Object value)
mv =
cw.visitMethod(
ACC_PUBLIC, "setBinding", "(Ljava/lang/String;Ljava/lang/Object;)V", null, null);
mv.visitCode();
// bindingMap.put(name, value);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "bindingMap", "Ljava/util/HashMap;");
mv.visitVarInsn(ALOAD, 1);
mv.visitVarInsn(ALOAD, 2);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"java/util/HashMap",
"put",
"(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
mv.visitInsn(POP);
// return
mv.visitInsn(RETURN);
mv.visitMaxs(3, 3);
mv.visitEnd();
}
{
// create the getBinding method
//
// public Object getBinding(String name)
mv =
cw.visitMethod(
ACC_PUBLIC, "getBinding", "(Ljava/lang/String;)Ljava/lang/Object;", null, null);
mv.visitCode();
// {TOS} <== bindingMap.get(name);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "bindingMap", "Ljava/util/HashMap;");
mv.visitVarInsn(ALOAD, 1);
mv.visitMethodInsn(
INVOKEVIRTUAL, "java/util/HashMap", "get", "(Ljava/lang/Object;)Ljava/lang/Object;");
// return {TOS}
mv.visitInsn(ARETURN);
mv.visitMaxs(2, 2);
mv.visitEnd();
}
{
// create the getName method
//
// public String getName()
mv = cw.visitMethod(ACC_PUBLIC, "getName", "()Ljava/lang/String;", null, null);
mv.visitCode();
// {TOS} <== rule.getName()
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitMethodInsn(
INVOKEVIRTUAL, "org/jboss/byteman/rule/Rule", "getName", "()Ljava/lang/String;");
// return {TOS}
mv.visitInsn(ARETURN);
mv.visitMaxs(1, 1);
mv.visitEnd();
}
// create the getAccessibleField method
//
// public Object getAccessibleField(Object owner, int fieldIndex)
{
mv =
cw.visitMethod(
ACC_PUBLIC,
"getAccessibleField",
"(Ljava/lang/Object;I)Ljava/lang/Object;",
null,
null);
mv.visitCode();
// {TOS} <== rule.getAccessibleField(owner, fieldIndex);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitVarInsn(ALOAD, 1);
mv.visitVarInsn(ILOAD, 2);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Rule",
"getAccessibleField",
"(Ljava/lang/Object;I)Ljava/lang/Object;");
// return {TOS}
mv.visitInsn(ARETURN);
mv.visitMaxs(3, 3);
mv.visitEnd();
}
// create the setAccessibleField method
//
// public void setAccessibleField(Object owner, Object value, int fieldIndex)
// rule.setAccessibleField(owner, value, fieldIndex);
{
mv =
cw.visitMethod(
ACC_PUBLIC,
"setAccessibleField",
"(Ljava/lang/Object;Ljava/lang/Object;I)V",
null,
null);
mv.visitCode();
// rule.setAccessibleField(owner, value, fieldIndex);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitVarInsn(ALOAD, 1);
mv.visitVarInsn(ALOAD, 2);
mv.visitVarInsn(ILOAD, 3);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Rule",
"setAccessibleField",
"(Ljava/lang/Object;Ljava/lang/Object;I)V");
// return
mv.visitInsn(RETURN);
mv.visitMaxs(4, 4);
mv.visitEnd();
}
// create the invokeAccessibleMethod method
//
// public Object invokeAccessibleMethod(Object target, Object[] args, int methodIndex)
// {TOS} <== rule.invokeAccessibleMethod(target, args, methodIndex);
{
mv =
cw.visitMethod(
ACC_PUBLIC,
"invokeAccessibleMethod",
"(Ljava/lang/Object;[Ljava/lang/Object;I)Ljava/lang/Object;",
null,
null);
mv.visitCode();
// rule.invokeAccessibleMethod(target, args, fieldIndex);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitVarInsn(ALOAD, 1);
mv.visitVarInsn(ALOAD, 2);
mv.visitVarInsn(ILOAD, 3);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Rule",
"invokeAccessibleMethod",
"(Ljava/lang/Object;[Ljava/lang/Object;I)Ljava/lang/Object;");
// return {TOS}
mv.visitInsn(ARETURN);
mv.visitMaxs(4, 4);
mv.visitEnd();
}
if (compileToBytecode) {
// we generate a single execute0 method if we want to run compiled and get
// the event, condiiton and action to insert the relevant bytecode to implement
// bind(), test() and fire()
{
// create the execute0() method
//
// private void execute0()
mv =
cw.visitMethod(
ACC_PRIVATE,
"execute0",
"()V",
null,
new String[] {"org/jboss/byteman/rule/exception/ExecuteException"});
mv.visitCode();
CompileContext compileContext = new CompileContext(mv);
// make sure we set the first line number before generating any code
compileContext.notifySourceLine(rule.getLine());
compileContext.addLocalCount(3); // for this and 2 object args
// bind();
rule.getEvent().compile(mv, compileContext);
// if (test())
rule.getCondition().compile(mv, compileContext);
Label l0 = new Label();
mv.visitJumpInsn(IFEQ, l0);
compileContext.addStackCount(-1);
// then
rule.getAction().compile(mv, compileContext);
// fire();
// end if
mv.visitLabel(l0);
// this will match the ENDRULE line
compileContext.notifySourceEnd();
// return
mv.visitInsn(RETURN);
// need to specify correct Maxs values
mv.visitMaxs(compileContext.getStackMax(), compileContext.getLocalMax());
mv.visitEnd();
}
} else {
// we generate the following methods if we want to run interpreted
{
// create the execute0() method
//
// private void execute0()
mv =
cw.visitMethod(
ACC_PRIVATE,
"execute0",
"()V",
null,
new String[] {"org/jboss/byteman/rule/exception/ExecuteException"});
mv.visitCode();
// bind();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, compiledHelperName, "bind", "()V");
// if (test())
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, compiledHelperName, "test", "()Z");
Label l0 = new Label();
mv.visitJumpInsn(IFEQ, l0);
// then
// fire();
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(INVOKESPECIAL, compiledHelperName, "fire", "()V");
// end if
mv.visitLabel(l0);
// return
mv.visitInsn(RETURN);
mv.visitMaxs(1, 1);
mv.visitEnd();
}
{
// create the bind method
//
// private void bind()
mv =
cw.visitMethod(
ACC_PRIVATE,
"bind",
"()V",
null,
new String[] {"org/jboss/byteman/rule/exception/ExecuteException"});
mv.visitCode();
// rule.getEvent().interpret(this);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Rule",
"getEvent",
"()Lorg/jboss/byteman/rule/Event;");
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Event",
"interpret",
"(Lorg/jboss/byteman/rule/helper/HelperAdapter;)Ljava/lang/Object;");
mv.visitInsn(RETURN);
mv.visitMaxs(2, 1);
mv.visitEnd();
}
{
// create the test method
//
// private boolean test()
mv =
cw.visitMethod(
ACC_PRIVATE,
"test",
"()Z",
null,
new String[] {"org/jboss/byteman/rule/exception/ExecuteException"});
mv.visitCode();
// {TOS} <== rule.getCondition().interpret(this);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Rule",
"getCondition",
"()Lorg/jboss/byteman/rule/Condition;");
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Condition",
"interpret",
"(Lorg/jboss/byteman/rule/helper/HelperAdapter;)Ljava/lang/Object;");
mv.visitTypeInsn(Opcodes.CHECKCAST, "java/lang/Boolean");
// unbox the returned Boolean
mv.visitMethodInsn(Opcodes.INVOKEVIRTUAL, "java/lang/Boolean", "booleanValue", "()Z");
// return {TOS}
mv.visitInsn(IRETURN);
mv.visitMaxs(2, 1);
mv.visitEnd();
}
{
// create the fire method
//
// private void fire()
mv =
cw.visitMethod(
ACC_PRIVATE,
"fire",
"()V",
null,
new String[] {"org/jboss/byteman/rule/exception/ExecuteException"});
mv.visitCode();
// rule.getAction().interpret(this);
mv.visitVarInsn(ALOAD, 0);
mv.visitFieldInsn(GETFIELD, compiledHelperName, "rule", "Lorg/jboss/byteman/rule/Rule;");
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Rule",
"getAction",
"()Lorg/jboss/byteman/rule/Action;");
mv.visitVarInsn(ALOAD, 0);
mv.visitMethodInsn(
INVOKEVIRTUAL,
"org/jboss/byteman/rule/Action",
"interpret",
"(Lorg/jboss/byteman/rule/helper/HelperAdapter;)Ljava/lang/Object;");
// return
mv.visitInsn(RETURN);
mv.visitMaxs(2, 1);
mv.visitEnd();
}
}
cw.visitEnd();
return cw.toByteArray();
}