public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) {
// DEBUG =
// clazz.getName().equals("abc/Def") &&
// method.getName(clazz).equals("abc");
// The minimum variable size is determined by the arguments.
codeAttribute.u2maxLocals =
ClassUtil.internalMethodParameterSize(method.getDescriptor(clazz), method.getAccessFlags());
if (DEBUG) {
System.out.println(
"VariableSizeUpdater: "
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz));
System.out.println(" Max locals: " + codeAttribute.u2maxLocals + " <- parameters");
}
// Go over all instructions.
codeAttribute.instructionsAccept(clazz, method, this);
// Remove the unused variables of the attributes.
codeAttribute.attributesAccept(clazz, method, variableCleaner);
}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) {
// DEBUG =
// clazz.getName().equals("abc/Def") &&
// method.getName(clazz).equals("abc");
// TODO: Remove this when the code has stabilized.
// Catch any unexpected exceptions from the actual visiting method.
try {
// Process the code.
visitCodeAttribute0(clazz, method, codeAttribute);
} catch (RuntimeException ex) {
System.err.println("Unexpected error while computing stack sizes:");
System.err.println(" Class = [" + clazz.getName() + "]");
System.err.println(
" Method = [" + method.getName(clazz) + method.getDescriptor(clazz) + "]");
System.err.println(
" Exception = [" + ex.getClass().getName() + "] (" + ex.getMessage() + ")");
if (DEBUG) {
method.accept(clazz, new ClassPrinter());
}
throw ex;
}
}
public void visitCodeAttribute0(Clazz clazz, Method method, CodeAttribute codeAttribute) {
if (DEBUG) {
System.out.println(
"StackSizeComputer: "
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz));
}
// Try to reuse the previous array.
int codeLength = codeAttribute.u4codeLength;
if (evaluated.length < codeLength) {
evaluated = new boolean[codeLength];
stackSizes = new int[codeLength];
} else {
Arrays.fill(evaluated, 0, codeLength, false);
}
// The initial stack is always empty.
stackSize = 0;
maxStackSize = 0;
// Evaluate the instruction block starting at the entry point of the method.
evaluateInstructionBlock(clazz, method, codeAttribute, 0);
// Evaluate the exception handlers.
codeAttribute.exceptionsAccept(clazz, method, this);
}
/**
* Marks the hierarchy of implementing or overriding methods corresponding to the given method, if
* any.
*/
protected void markMethodHierarchy(Clazz clazz, Method method) {
int accessFlags = method.getAccessFlags();
if ((accessFlags & (ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC)) == 0
&& !ClassUtil.isInitializer(method.getName(clazz))) {
// We can skip private and static methods in the hierarchy, and
// also abstract methods, unless they might widen a current
// non-public access.
int requiredUnsetAccessFlags =
ClassConstants.ACC_PRIVATE
| ClassConstants.ACC_STATIC
| ((accessFlags & ClassConstants.ACC_PUBLIC) == 0 ? 0 : ClassConstants.ACC_ABSTRACT);
clazz.accept(
new ConcreteClassDownTraveler(
new ClassHierarchyTraveler(
true,
true,
false,
true,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(0, requiredUnsetAccessFlags, this)))));
}
}
/**
* Marks the hierarchy of implementing or overriding methods corresponding to the given method, if
* any.
*/
protected void markMethodHierarchy(Clazz clazz, Method method) {
int accessFlags = method.getAccessFlags();
if ((accessFlags & (ClassConstants.ACC_PRIVATE | ClassConstants.ACC_STATIC)) == 0
&& !ClassUtil.isInitializer(method.getName(clazz))) {
// We can skip private and static methods in the hierarchy, and
// also abstract methods, unless they might widen a current
// non-public access.
int requiredUnsetAccessFlags =
ClassConstants.ACC_PRIVATE
| ClassConstants.ACC_STATIC
| ((accessFlags & ClassConstants.ACC_PUBLIC) == 0 ? 0 : ClassConstants.ACC_ABSTRACT);
// Mark default implementations in interfaces down the hierarchy.
// TODO: This may be premature if there aren't any concrete implementing classes.
clazz.accept(
new ClassAccessFilter(
ClassConstants.ACC_ABSTRACT,
0,
new ClassHierarchyTraveler(
false,
false,
false,
true,
new ProgramClassFilter(
new ClassAccessFilter(
ClassConstants.ACC_ABSTRACT,
0,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(
0, requiredUnsetAccessFlags, defaultMethodUsageMarker)))))));
// Mark other implementations.
clazz.accept(
new ConcreteClassDownTraveler(
new ClassHierarchyTraveler(
true,
true,
false,
true,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(0, requiredUnsetAccessFlags, this)))));
}
}
/**
* Marks the hierarchy of implementing or overriding methods corresponding to the given method, if
* any.
*/
protected void markMethodHierarchy(Clazz clazz, Method method) {
if ((method.getAccessFlags()
& (ClassConstants.INTERNAL_ACC_PRIVATE | ClassConstants.INTERNAL_ACC_STATIC))
== 0) {
clazz.accept(
new ConcreteClassDownTraveler(
new ClassHierarchyTraveler(
true,
true,
false,
true,
new NamedMethodVisitor(
method.getName(clazz),
method.getDescriptor(clazz),
new MemberAccessFilter(
0,
ClassConstants.INTERNAL_ACC_PRIVATE
| ClassConstants.INTERNAL_ACC_STATIC
| ClassConstants.INTERNAL_ACC_ABSTRACT,
this)))));
}
}
/**
* Evaluates a block of instructions that hasn't been handled before, starting at the given offset
* and ending at a branch instruction, a return instruction, or a throw instruction. Branch
* instructions are handled recursively.
*/
private void evaluateInstructionBlock(
Clazz clazz, Method method, CodeAttribute codeAttribute, int instructionOffset) {
if (DEBUG) {
if (evaluated[instructionOffset]) {
System.out.println("-- (instruction block at " + instructionOffset + " already evaluated)");
} else {
System.out.println("-- instruction block:");
}
}
// Remember the initial stack size.
int initialStackSize = stackSize;
// Remember the maximum stack size.
if (maxStackSize < stackSize) {
maxStackSize = stackSize;
}
// Evaluate any instructions that haven't been evaluated before.
while (!evaluated[instructionOffset]) {
// Mark the instruction as evaluated.
evaluated[instructionOffset] = true;
Instruction instruction = InstructionFactory.create(codeAttribute.code, instructionOffset);
if (DEBUG) {
int stackPushCount = instruction.stackPushCount(clazz);
int stackPopCount = instruction.stackPopCount(clazz);
System.out.println(
"["
+ instructionOffset
+ "]: "
+ stackSize
+ " - "
+ stackPopCount
+ " + "
+ stackPushCount
+ " = "
+ (stackSize + stackPushCount - stackPopCount)
+ ": "
+ instruction.toString(instructionOffset));
}
// Compute the instruction's effect on the stack size.
stackSize -= instruction.stackPopCount(clazz);
if (stackSize < 0) {
throw new IllegalArgumentException(
"Stack size becomes negative after instruction "
+ instruction.toString(instructionOffset)
+ " in ["
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz)
+ "]");
}
stackSizes[instructionOffset] = stackSize += instruction.stackPushCount(clazz);
// Remember the maximum stack size.
if (maxStackSize < stackSize) {
maxStackSize = stackSize;
}
// Remember the next instruction offset.
int nextInstructionOffset = instructionOffset + instruction.length(instructionOffset);
// Visit the instruction, in order to handle branches.
instruction.accept(clazz, method, codeAttribute, instructionOffset, this);
// Stop evaluating after a branch.
if (exitInstructionBlock) {
break;
}
// Continue with the next instruction.
instructionOffset = nextInstructionOffset;
if (DEBUG) {
if (evaluated[instructionOffset]) {
System.out.println("-- (instruction at " + instructionOffset + " already evaluated)");
}
}
}
// Restore the stack size for possible subsequent instruction blocks.
this.stackSize = initialStackSize;
}
public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) {
// DEBUG =
// clazz.getName().equals("abc/Def") &&
// method.getName(clazz).equals("abc");
if (DEBUG) {
method.accept(clazz, new ClassPrinter());
}
branchTargetFinder.visitCodeAttribute(clazz, method, codeAttribute);
// Don't bother if there aren't any subroutines anyway.
if (!containsSubroutines(codeAttribute)) {
return;
}
if (DEBUG) {
System.out.println(
"SubroutineInliner: processing ["
+ clazz.getName()
+ "."
+ method.getName(clazz)
+ method.getDescriptor(clazz)
+ "]");
}
// Append the body of the code.
codeAttributeComposer.reset();
codeAttributeComposer.beginCodeFragment(codeAttribute.u4codeLength);
// Copy the non-subroutine instructions.
int offset = 0;
while (offset < codeAttribute.u4codeLength) {
Instruction instruction = InstructionFactory.create(codeAttribute.code, offset);
int instructionLength = instruction.length(offset);
// Is this returning subroutine?
if (branchTargetFinder.isSubroutine(offset)
&& branchTargetFinder.isSubroutineReturning(offset)) {
// Skip the subroutine.
if (DEBUG) {
System.out.println(
" Skipping original subroutine instruction " + instruction.toString(offset));
}
// Append a label at this offset instead.
codeAttributeComposer.appendLabel(offset);
} else {
// Copy the instruction, inlining any subroutine call recursively.
instruction.accept(clazz, method, codeAttribute, offset, this);
}
offset += instructionLength;
}
// Copy the exceptions. Note that exceptions with empty try blocks
// are automatically removed.
codeAttribute.exceptionsAccept(clazz, method, subroutineExceptionInliner);
if (DEBUG) {
System.out.println(" Appending label after code at [" + offset + "]");
}
// Append a label just after the code.
codeAttributeComposer.appendLabel(codeAttribute.u4codeLength);
// End and update the code attribute.
codeAttributeComposer.endCodeFragment();
codeAttributeComposer.visitCodeAttribute(clazz, method, codeAttribute);
if (DEBUG) {
method.accept(clazz, new ClassPrinter());
}
}