/**
* Verifies that the current state of the local variables array matches the state specified by a
* stack map entry.
*
* @param target the target encapsulating a stack map entry specifying what the current state of
* the local variables array should be
* @param replaceWithTarget if true, then the current state of the local variable array is updated
* to reflect the state recorded in the stack map entry
*/
public void mergeLocals(Target target, boolean replaceWithTarget) {
Klass[] recordedTypes = target.getLocals();
if (recordedTypes.length > localTypes.length) {
throw codeParser.verifyError("size of recorded and derived local variable array differs");
}
/*
* Check the locals
*/
for (int i = 0; i < recordedTypes.length; i++) {
Klass recordedType = recordedTypes[i];
Klass derivedType = localTypes[i];
if (!recordedType.isAssignableFrom(derivedType)) {
/*
* For some reason, the preverifier occasionally generates
* stack map entries for local variables even though the
* local variable is dead. What's more, in these cases,
* it determines that the type resulting from merging an
* object type and an interface type is the interface
* type. This makes no sense to me, but the case must be
* allowed.
*/
if (!recordedType.isInterface() || derivedType.isPrimitive()) {
throw codeParser.verifyError("invalid type in local variable");
}
}
if (replaceWithTarget) {
localTypes[i] = recordedType;
}
}
}
/**
* Gets the super class of this class.
*
* @return the super class of this class
*/
public final ProxyType getSuperclass() throws IOException, SDWPException {
Klass superClass = klass.getSuperclass();
// the "-bytecode-" class actually inherits from INT, but don't tell jdwp that!
if (superClass != null && !superClass.isPrimitive()) {
return ptm.lookup(superClass, true);
}
return null;
}
@SuppressWarnings("unchecked")
private void addFields(List list, boolean isStatic) {
int count = klass.getFieldCount(isStatic);
for (int i = 0; i != count; ++i) {
Field field = klass.getField(i, isStatic);
FieldID fid = new FieldID(JDWP.getTag(field.getType()), field.getOffset(), isStatic, getID());
ProxyField proxyField = new ProxyField(fid, field);
list.add(proxyField);
}
}
/**
* Gets the class file corresponding to a given instance class. The <code>klass</code> must not
* yet be converted and it must not be a {@link Klass#isSynthetic() synthetic} class.
*
* @param klass the instance class for which a class file is requested
* @return the class file for <code>klass</code>
*/
ClassFile getClassFile(Klass klass) {
Assert.that(!klass.isSynthetic(), "synthethic class has no classfile");
String name = klass.getName();
ClassFile classFile = (ClassFile) classFiles.get(name);
if (classFile == null) {
classFile = new ClassFile(klass);
classFiles.put(name, classFile);
}
return classFile;
}
/**
* Emulates the storing of a value to a local variable.
*
* @param index the index of the local variable being stored to
* @param type the type of the value
* @param local the variable to which the value is stored
*/
public void store(int index, Klass type, Local local) {
Klass localType = local.getType();
Assert.that(localType.isAssignableFrom(type) || localType == getLocalTypeFor(type));
verifyLocalVariableIndex(localType, index);
localTypes[index] = type;
if (localType.isDoubleWord()) {
localTypes[index + 1] = Klass.getSecondWordType(localType);
} else {
verifyUseOfSquawkPrimitive(localType, type);
}
}
@SuppressWarnings("unchecked")
private void addMethods(List list, boolean isStatic) {
int count = klass.getMethodCount(isStatic);
for (int i = 0; i != count; ++i) {
Method method = klass.getMethod(i, isStatic);
if (!method.isHosted()) {
MethodID mid = new MethodID(method.getOffset(), isStatic);
ProxyMethod proxyMethod = new ProxyMethod(mid, method);
list.add(proxyMethod);
}
}
}
/**
* Gets the fully qualified name of this type. The returned name is formatted as it might appear
* in a Java programming language declaration for objects of this type.
*
* <p>For primitive classes the returned name is the name of the corresponding primitive type; for
* example, "int" is returned as the name of the class represented by {@link
* java.lang.Integer#TYPE Integer.TYPE}.
*
* @return a string containing the type name.
*/
public String getName() {
String name = klass.getName();
if (!klass.isArray()) {
return name;
}
int dimensions = 0;
while (name.charAt(dimensions) == '[') {
++dimensions;
}
name = name.substring(dimensions);
char first = name.charAt(0);
if (first == 'L') {
name = name.substring(1, name.length() - 2).replace('/', '.');
} else {
switch (first) {
case 'I':
name = "int";
break;
case 'J':
name = "long";
break;
case 'F':
name = "float";
break;
case 'D':
name = "double";
break;
case 'Z':
name = "boolean";
break;
case 'C':
name = "char";
break;
case 'S':
name = "short";
break;
case 'B':
name = "byte";
break;
case 'V':
name = "void";
break;
}
}
while (dimensions-- != 0) {
name += "[]";
}
return name;
}
/**
* Determines if the operand stack or local variable array currently contains an entry whose type
* is equal to or a subtype of a given type.
*
* @param type the type to search for
* @return true if an entry was found
*/
public boolean containsType(Klass type) {
for (int i = 0; i < localTypes.length; i++) {
if (type.isAssignableFrom(localTypes[i])) {
return true;
}
}
for (int i = 0; i < sp; i++) {
StackProducer producer = stack[i];
if (producer != null && type.isAssignableFrom(producer.getType())) {
return true;
}
}
return false;
}
/** {@inheritDoc} */
public void load(Klass klass) {
Assert.that(VM.isHosted() || VM.getCurrentIsolate().getLeafSuite() == suite);
int state = klass.getState();
if (state < Klass.STATE_LOADED) {
if (klass.isArray()) {
load(klass.getComponentType());
} else {
lastClassNameStack.push(klass.getName());
ClassFile classFile = getClassFile(klass);
load(classFile);
lastClassNameStack.pop();
}
}
}
/**
* Get a <code>Local</code> instance to represent a value of a given type that will be
* stored/loaded to/from a given local variable.
*
* @param type the type of the value
* @param index the index of the local variable
* @param isParameter true if the local is a parameter
* @return the variable at index <code>index</code> in which values of type <code>type</code> are
* stored
*/
private Local allocateLocalPrim(Klass type, int index, boolean isParameter) {
Assert.that(localTypes.length < 0xFFFF);
Assert.that(
index >= 0 && index < localTypes.length,
"index=" + index + " localTypes.length=" + localTypes.length);
Klass localType = getLocalTypeFor(type);
int key = localType.getSuiteID();
/* We need a hard partition between uses of a slot as a reference vs. an Address, Offset, or UWord.
* The partitioning of java primitives and objects is accomplished not only by the type passed in here, but
* by the bytecode verifier. We can't be sure that some bytecodes are refering to the same local variable
* as both a reference and as a Squawk primitive. Without that kind of support we are conservative here
* and force a clash whenever javac uses the same local index for a reference and a Squawk primitive.
*/
if (localType.isSquawkPrimitive()) {
key = Klass.REFERENCE.getSuiteID();
}
key = key << 16 | index;
if (localValues == null) {
localValues = new IntHashtable();
}
Local local = (Local) localValues.get(key);
if (local == null) {
local = new Local(localType, index, isParameter);
localValues.put(key, local);
}
/*
* Ensure that the original class file does not use the same local variable
* for both a Squawk primitive value and any other reference value. This prevents the
* translator from having to do a complete liveness analysis to de-multiplex
* such a local variable slot. Such de-multiplexing is required as Squawk primitives
* are 'magically' translated into integers (or longs on a 64 bit system).
*/
if (localType.isSquawkPrimitive() || local.getType().isSquawkPrimitive()) {
if (localType != local.getType()) {
throw codeParser.verifyError(
getBadAddressLocalVariableMessage(index, localType, local.getType()));
}
}
// System.out.println("allocated: "+local+" index "+index);
/// *if[SCOPEDLOCALVARIABLES]*/
codeParser.localVariableAllocated(codeParser.getCurrentIP(), local);
/// *end[SCOPEDLOCALVARIABLES]*/
return local;
}
/**
* Pops a value off the operand stack.
*
* @param type the type that the value popped off the operand stack must be assignable to
* @return the instruction that produced the popped value
*/
public StackProducer pop(Klass type) {
StackProducer producer;
if (type.isDoubleWord()) {
if (sp < 2) {
throw codeParser.verifyError("operand stack underflow");
}
if (!isTopDoubleWord()) {
throw codeParser.verifyError("incompatible type on operand stack " + tosKlassName());
}
sp -= 2;
producer = stack[sp];
} else {
if (sp < 1) {
throw codeParser.verifyError("operand stack underflow");
}
if (isTopDoubleWord()) {
throw codeParser.verifyError("incompatible type on operand stack " + tosKlassName());
}
producer = stack[--sp];
/*
* The primitive one-word, non-float types are all assignment compatible with each other
*/
if (type.isPrimitive() && type != Klass.FLOAT) {
type = Klass.INT;
}
}
Assert.that(producer != null);
/*
* Interfaces are treated as java.lang.Object in the verifier.
*/
if (type.isInterface()) {
type = Klass.OBJECT;
}
/*
* Verify that the instruction is producing the correct type.
*/
if (!type.isAssignableFrom(producer.getType())) {
throw codeParser.verifyError(
"incompatible type: '" + type + "' is not assignable from '" + producer.getType() + "'");
}
return producer;
}
/**
* Generate squawk code for methods of <code>klass</code> when doing whole-suite translation
* (inlining, etc.)
*
* @param klass the klass to generate code for
*/
void convertPhase2(Klass klass) {
Assert.that(translationStrategy != BY_METHOD);
convert(klass);
if (klass.getState() < Klass.STATE_CONVERTED) {
if (!VM
.isVerbose()) { // "squawk -verbose" will show the class names as it finishes loading
// them, which is progress enough
traceProgress();
}
lastClassNameStack.push(klass.getName());
ClassFile classFile = getClassFile(klass);
classFile.convertPhase2(this, false);
classFiles.remove(klass.getName());
lastClassNameStack.pop();
}
}
/**
* Returns the runtime class of an object. That <tt>Class</tt> object is the object that is locked
* by <tt>static synchronized</tt> methods of the represented class.
*
* @return the object of type <code>Class</code> that represents the runtime class of the object.
*/
public final Class getClass() {
Klass klass = GC.getKlass(this);
if (klass == Klass.STRING_OF_BYTES) {
klass = Klass.STRING;
}
return Klass.asClass(klass);
}
/**
* Gets the type of a local variable that is used to store a value of a given class. This method
* partitions all classes into one of the following categories:
*
* <p>
*
* <blockquote>
*
* <pre>
*
* Local Variable Type | Types
* ---------------------+-------
* INT | boolean, byte, short, int
* FLOAT | float
* LONG | long
* DOUBLE | double
* ADDRESS | Address
* UWORD | UWord
* OFFSET | Offset
* REFERENCE | types in java.lang.Object hierarchy
*
* </pre>
*
* </blockquote>
*
* <p>
*
* @param type the type of a value that will be stored in a local variable
* @return the local variable type for storing values of type <code>type</code>
*/
public static Klass getLocalTypeFor(Klass type) {
switch (type.getSystemID()) {
case CID.BOOLEAN:
case CID.BYTE:
case CID.SHORT:
case CID.CHAR:
case CID.INT:
{
return Klass.INT;
}
case CID.FLOAT:
case CID.LONG:
case CID.DOUBLE:
{
return type;
}
case CID.UWORD:
case CID.OFFSET:
case CID.ADDRESS:
{
return type;
}
default:
{
Assert.that(Klass.REFERENCE.isAssignableFrom(type));
return Klass.REFERENCE;
}
}
}
/**
* Tests two given types to ensure that they are both {@link Klass#isSquawkPrimitive() Squawk
* primitives} or both not Squawk primitives. If they are both Squawk primitives, then they must
* be exactly the same type. This enforces the constraint that Squawk primitive values cannot be
* assigned to or compared with any other type.
*
* @param type1 the first type to compare
* @param type2 the second type to compare
*/
public void verifyUseOfSquawkPrimitive(Klass type1, Klass type2) {
if (type1.isSquawkPrimitive() || type2.isSquawkPrimitive()) {
if (type1 != type2) {
// Offsets are implemented as Words
// if (type1.getClassID() + type2.getClassID() != CID.UWORD + CID.OFFSET) {
String type = type1.getName();
throw codeParser.verifyError(
type
+ " values can only be written to or compared with other "
+ type
+ " values, not with "
+ type2.getName());
// }
}
}
}
/**
* Gets the type of the value at a given index on the operand stack.
*
* @param index the operand stack index
* @return the type of the value at index <code>index</code> on the operand stack
*/
public Klass getStackTypeAt(int index) {
Assert.that(index < sp, "index out of bounds");
if (stack[index] == null) {
return Klass.getSecondWordType(stack[index - 1].getType());
} else {
return stack[index].getType();
}
}
/**
* Returns interfaces directly implemented by this type.
*
* @return a List of the interfaces directly implemented by this type
*/
@SuppressWarnings("unchecked")
public List getInterfaces() throws IOException, SDWPException {
Klass[] interfaces = klass.getInterfaces();
List list = new ArrayList(interfaces.length);
for (int i = 0; i != interfaces.length; ++i) {
list.add(ptm.lookup(interfaces[i], true));
}
return list;
}
/**
* Verify that a local variable index for a given type is not out of bounds.
*
* @param type the type of the local variable at <code>index</code> in the local variables array
* @param index the index of a local variable
*/
public void verifyLocalVariableIndex(Klass type, int index) {
if (index < 0) {
throw codeParser.verifyError("invalid local variable index");
}
if (type.isDoubleWord()) {
index++;
}
if (index >= localTypes.length) {
throw codeParser.verifyError("invalid local variable index");
}
}
/**
* Returns a list containing each {@link Method} declared directly in this type. Inherited methods
* are not included. Constructors, the initialization method if any, and any synthetic methods
* created by the compiler are included in the list.
*
* <p>For arrays and primitive classes, the returned list is always empty.
*
* @return a list {@link Method} objects; the list has length 0 if no methods exist.
*/
public List getMethods() {
if (methods == null) {
if (klass.isArray()) {
methods = Collections.EMPTY_LIST;
} else {
methods = new ArrayList();
addMethods(methods, true);
addMethods(methods, false);
}
}
return methods;
}
/**
* Merges the current state of the operand stack into the saved state at a control flow target.
* This method also verifies that the current state of the operand stack matches the expected
* state of the operand stack at the target as pecified by a stack map entry.
*
* @param target the target encapsulting the merged state of the operand stack at a distinct
* address
* @param replaceWithTarget if true, then the current state of the operand stack is updated to
* reflect the state recorded in the stack map entry
*/
public void mergeStack(Target target, boolean replaceWithTarget) {
Klass[] recordedTypes = target.getStack();
/*
* Fail if the map sp is different
*/
if (recordedTypes.length != getStackSize()) {
throw codeParser.verifyError("size of recorded and derived stack differs");
}
/*
* Check the stack items
*/
for (int r = 0, d = 0; r < recordedTypes.length; ++r, ++d) {
Klass recordedType = recordedTypes[r];
Klass derivedType = getStackTypeAt(d);
if (!recordedType.isAssignableFrom(derivedType)) {
// Interfaces are treated like java.lang.Object in the verifier according to the CLDC spec.
if (!recordedType.isInterface() || !Klass.OBJECT.isAssignableFrom(derivedType)) {
throw codeParser.verifyError(
"invalid type on operand stack @ "
+ d
+ ": expected "
+ recordedType
+ ", received "
+ derivedType);
}
}
}
/*
* Merge the instructions on the stack
*/
target.merge(this);
if (replaceWithTarget) {
resetStack(target, false);
}
}
/** {@inheritDoc} */
public void convert(Klass klass) {
lastClassNameStack.push(klass.getName());
int state = klass.getState();
if (state < Klass.STATE_CONVERTING) {
if (klass.isArray()) {
convert(Klass.OBJECT);
klass.changeState(Klass.STATE_CONVERTED);
} else {
traceProgress();
ClassFile classFile = getClassFile(klass);
classFile.convertPhase1(this, translationStrategy != BY_METHOD);
if (klass.hasGlobalStatics()) {
// record globals now.
recordGlobalStatics(klass);
}
if (translationStrategy == BY_METHOD || translationStrategy == BY_CLASS) {
// if NOT inlining, then generate squawk code now.
classFile.convertPhase2(this, translationStrategy == BY_METHOD);
classFiles.remove(klass.getName());
}
}
}
lastClassNameStack.pop();
}
/** Load and converts the closure of classes in the current suite. */
public void computeClosure() {
boolean changed = true;
while (changed) {
changed = false;
for (int cno = 0; cno < suite.getClassCount(); cno++) {
Klass klass = suite.getKlass(cno);
if (klass == null) {
continue; // if not floats, or if deferred errors, there can be some missing classes
}
if (klass.getState() < Klass.STATE_LOADED) {
load(klass);
changed = true;
}
if (klass.getState() < Klass.STATE_CONVERTING) {
convert(klass);
changed = true;
}
}
}
}
/**
* Pushes a value to the operand stack.
*
* @param producer the instruction producing the value being pushed
*/
public void push(StackProducer producer) {
Klass type = producer.getType();
Assert.that(type != Klass.VOID);
/*
* Check for overflow and push the producer.
*/
if (sp == maxStack) {
throw codeParser.verifyError("operand stack overflow");
}
stack[sp++] = producer;
/*
* For long and double check for overflow and then add a null word to the stack.
*/
if (type.isDoubleWord()) {
if (sp == maxStack) {
throw codeParser.verifyError("operand stack overflow");
}
stack[sp++] = null;
}
}
/**
* Traces a type on the operand stack or in a local variable.
*
* @param type the type to trace
* @param prefix the prefix to use if <code>isDerived</code> is true otherwise a prefix of spaces
* the same length as <code>prefix</code> is used instead
* @param isDerived specifies if this a type derived by the verifer or is specified by a stack map
* entry
*/
private void traceType(Klass type, String prefix, boolean isDerived) {
if (Translator.TRACING_ENABLED) {
if (!isDerived) {
char[] spaces = new char[prefix.length()];
Arrays.fill(spaces, ' ');
Tracer.trace(new String(spaces));
} else {
Tracer.trace(prefix);
}
String name = (type == null ? "-T-" : type.getInternalName());
if (isDerived) {
Tracer.traceln(" " + name);
} else {
Tracer.traceln("{" + name + "}");
}
}
}
/**
* Emulates loading a value of a given type from a local variable.
*
* @param index the index of the local variable being loaded from
* @param localType the expected type of the variable from which the value is loaded
* @return the variable from which the value is loaded
*/
public Local load(int index, Klass localType) {
verifyLocalVariableIndex(localType, index);
Klass derivedType = localTypes[index];
if (!localType.isAssignableFrom(derivedType)) {
throw codeParser.verifyError("incompatible type in local variable");
}
if (localType.isDoubleWord()) {
Klass secondWordType = Klass.getSecondWordType(localType);
if (!secondWordType.isAssignableFrom(localTypes[index + 1])) {
throw codeParser.verifyError("incompatible type in local variable");
}
}
if (derivedType.isSquawkPrimitive()) {
localType = derivedType;
}
return allocateLocal(localType, index);
}
/**
* Creates and returns the detailed error message when a local variable is used as a Squawk
* primitive as well as some value not of exactly the same type. The message includes information
* derived from the LocalVariableTable attribute so that the source code can be easily changed.
*
* @param index the local variable index that is (mis)used
* @return the detailed error message
*/
private String getBadAddressLocalVariableMessage(int index, Klass type1, Klass type2) {
Assert.that(type1.isSquawkPrimitive() || type2.isSquawkPrimitive());
if (type2.isSquawkPrimitive()) {
Klass otherType = type1;
type1 = type2;
type2 = otherType;
}
StringBuffer buf =
new StringBuffer(
"Stack location "
+ index
+ " cannot be used for both a local variable of type "
+ type1.getName()
+ " and of type "
+ type2.getName()
+ ". Try moving the variable of type "
+ type1.getName()
+ " to the top-most scope of the method.");
Enumeration e = codeParser.getLocalVariableTableEntries();
if (e != null) {
buf.append(" (source code usage: ");
while (e.hasMoreElements()) {
LocalVariableTableEntry entry = (LocalVariableTableEntry) e.nextElement();
if (entry.getIndex() == index) {
int start = codeParser.getSourceLineNumber(entry.getStart().getBytecodeOffset());
int end = codeParser.getSourceLineNumber(entry.getEnd().getBytecodeOffset());
buf.append(entry.getType().getName())
.append(' ')
.append(entry.getName())
.append(" from line ")
.append(start)
.append(" to line ")
.append(end)
.append(';');
}
}
}
return buf.toString();
}
/**
* Gets an identifying name for the source corresponding to the declaration of this type.
* Interpretation of this string is the responsibility of the source repository mechanism.
*
* <p>The returned name is dependent on VM's default stratum ({@link
* VirtualMachine#getDefaultStratum()}). In the reference implementation, when using the base
* stratum, the returned string is the unqualified name of the source file containing the
* declaration of this type. In other strata the returned source name is the first source name for
* that stratum. Since other languages may have more than one source name for a reference type,
* the use of {@link Location#sourceName()} or {@link #sourceNames(String)} is preferred.
*
* <p>
*
* @return the string source file name or null if it is not known
*/
public String getSourceName() {
return klass.getSourceFileName();
}
/**
* Returns the modifiers for the reference type. ACC_PUBLIC, ACC_FINAL, etc. Undefined for arrays
* and primitive type.
*
* @return the class modifiers in JVM Spec format.
*/
public int getModifiers() {
return klass.getModifiers() & Modifier.getJVMClassModifiers();
}
/**
* Creates a Frame instance to emulate and verify the execution of a single class file method.
*
* @param codeParser the parser used to parse the "Code" attribute of the method being emulated
* @param extraLocals the number of extra local variables needed
*/
public Frame(CodeParser codeParser, int extraLocals) {
this.maxStack = codeParser.getMaxStack();
this.codeParser = codeParser;
/*
* Initialize the operand stack
*/
stack = new StackProducer[maxStack];
/*
* Initialize the types in the local variables
*/
localTypes = new Klass[codeParser.getMaxLocals() + extraLocals];
Method method = codeParser.getMethod();
Klass[] parameterTypes = method.getParameterTypes();
Local[] parameterLocals = null;
if (Translator.REVERSE_PARAMETERS && method.isInterpreterInvoked()) {
parameterLocals = new Local[parameterTypes.length];
}
int javacIndex = 0;
/*
* Initialize 'this' in non-static methods. The type of 'this' is
* UNINITIALIZED_THIS if this method is a constructor in any class
* except java.lang.Object otherwise it is the class in which the
* method was defined.
*/
if (!method.isStatic() || method.isConstructor()) {
Assert.that(parameterLocals == null);
Klass thisType = method.getDefiningClass();
if (method.isConstructor() && thisType != Klass.OBJECT) {
thisType = Klass.UNINITIALIZED_THIS;
}
Local thisLocal = allocateParameter(thisType, javacIndex);
store(javacIndex, thisType, thisLocal);
javacIndex++;
}
/*
* Initialize locals for the parameters.
*/
int parameterIndex = javacIndex;
for (int i = 0; i < parameterTypes.length; i++) {
Klass parameterType = parameterTypes[i];
Local parameterLocal = allocateParameter(parameterType, javacIndex);
if (parameterLocals != null) {
parameterLocals[i] = parameterLocal;
}
if (Klass.SQUAWK_64) {
if (javacIndex != parameterIndex) {
Assert.that(parameterIndex < javacIndex);
parameterLocal.setParameterIndex(parameterIndex);
}
parameterIndex++;
}
store(javacIndex, parameterType, parameterLocal);
javacIndex += (parameterType.isDoubleWord() ? 2 : 1);
}
parameterLocalsCount = javacIndex;
/*
* Adjust the parameter offsets for parameter order reversal.
*/
if (parameterLocals != null) {
parameterIndex = 0;
for (int i = parameterTypes.length - 1; i >= 0; i--) {
Klass parameterType = parameterTypes[i];
parameterLocals[i].setParameterIndex(parameterIndex++);
if (!Klass.SQUAWK_64 && parameterType.isDoubleWord()) {
parameterIndex++;
}
}
}
/*
* Initialize the remaining local variables to the TOP type
*/
while (javacIndex < localTypes.length) {
localTypes[javacIndex++] = Klass.TOP;
}
}
/**
* Like <code>klass</code> must not yet be converted and it must not be a {@link
* Klass#isSynthetic() synthetic} class.
*
* @param klass the instance class for which a class file is requested
* @return the class file for <code>klass</code>, or null if that ClassFile has not been
* translated by this translator.
*/
ClassFile lookupClassFile(Klass klass) {
Assert.that(!klass.isSynthetic(), "synthethic class has no classfile");
ClassFile classFile = (ClassFile) classFiles.get(klass.getInternalName());
return classFile;
}