Track multiple values in IntInterpreter

This helps us catch a few more cases in DummyTransformer.
bzip2
Graham 5 years ago
parent 3c1ec9f210
commit 766b544fc1
  1. 128
      deob/src/main/java/dev/openrs2/deob/analysis/IntInterpreter.java
  2. 39
      deob/src/main/java/dev/openrs2/deob/analysis/IntValue.java
  3. 116
      deob/src/main/java/dev/openrs2/deob/transform/DummyTransformer.java

@ -3,6 +3,8 @@ package dev.openrs2.deob.analysis;
import java.util.List;
import java.util.stream.Collectors;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import dev.openrs2.asm.InsnNodeUtils;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.Type;
@ -14,11 +16,13 @@ import org.objectweb.asm.tree.analysis.BasicValue;
import org.objectweb.asm.tree.analysis.Interpreter;
public final class IntInterpreter extends Interpreter<IntValue> {
private final Interpreter<BasicValue> basicInterpreter = new BasicInterpreter();
// TODO(gpe): this is fairly arbitrary and will need tweaking
private static final int MAX_TRACKED_VALUES = 8;
private final Integer[] parameters;
private final Interpreter<BasicValue> basicInterpreter = new BasicInterpreter();
private final ImmutableSet<Integer>[] parameters;
public IntInterpreter(Integer[] parameters) {
public IntInterpreter(ImmutableSet<Integer>[] parameters) {
super(Opcodes.ASM7);
this.parameters = parameters;
}
@ -86,25 +90,36 @@ public final class IntInterpreter extends Interpreter<IntValue> {
return null;
}
if (value.isConstant()) {
var v = value.getIntValue();
if (value.isUnknown()) {
return IntValue.newUnknown(basicValue);
}
var set = ImmutableSet.<Integer>builder();
for (var v : value.getIntValues()) {
switch (insn.getOpcode()) {
case Opcodes.INEG:
return IntValue.newConstant(basicValue, -v);
set.add(-v);
break;
case Opcodes.IINC:
var iinc = (IincInsnNode) insn;
return IntValue.newConstant(basicValue, v + iinc.incr);
set.add(v + iinc.incr);
break;
case Opcodes.I2B:
return IntValue.newConstant(basicValue, (byte) v);
set.add((int) (byte) (int) v);
break;
case Opcodes.I2C:
return IntValue.newConstant(basicValue, (char) v);
set.add((int) (char) (int) v);
break;
case Opcodes.I2S:
return IntValue.newConstant(basicValue, (short) v);
set.add((int) (short) (int) v);
break;
default:
return IntValue.newUnknown(basicValue);
}
}
return IntValue.newUnknown(basicValue);
return IntValue.newConstant(basicValue, set.build());
}
@Override
@ -114,43 +129,61 @@ public final class IntInterpreter extends Interpreter<IntValue> {
return null;
}
if (value1.isConstant() && value2.isConstant()) {
var v1 = value1.getIntValue();
var v2 = value2.getIntValue();
if (value1.isUnknown() || value2.isUnknown()) {
return IntValue.newUnknown(basicValue);
}
switch (insn.getOpcode()) {
case Opcodes.IADD:
return IntValue.newConstant(basicValue, v1 + v2);
case Opcodes.ISUB:
return IntValue.newConstant(basicValue, v1 - v2);
case Opcodes.IMUL:
return IntValue.newConstant(basicValue, v1 * v2);
case Opcodes.IDIV:
if (v2 == 0) {
var set = ImmutableSet.<Integer>builder();
for (var v1 : value1.getIntValues()) {
for (var v2 : value2.getIntValues()) {
switch (insn.getOpcode()) {
case Opcodes.IADD:
set.add(v1 + v2);
break;
case Opcodes.ISUB:
set.add(v1 - v2);
break;
case Opcodes.IMUL:
set.add(v1 * v2);
break;
case Opcodes.IDIV:
if (v2 == 0) {
return IntValue.newUnknown(basicValue);
}
set.add(v1 / v2);
break;
case Opcodes.IREM:
if (v2 == 0) {
return IntValue.newUnknown(basicValue);
}
set.add(v1 % v2);
break;
case Opcodes.ISHL:
set.add(v1 << v2);
break;
case Opcodes.ISHR:
set.add(v1 >> v2);
break;
case Opcodes.IUSHR:
set.add(v1 >>> v2);
break;
case Opcodes.IAND:
set.add(v1 & v2);
break;
case Opcodes.IOR:
set.add(v1 | v2);
break;
case Opcodes.IXOR:
set.add(v1 ^ v2);
break;
default:
return IntValue.newUnknown(basicValue);
}
return IntValue.newConstant(basicValue, v1 / v2);
case Opcodes.IREM:
if (v2 == 0) {
return IntValue.newUnknown(basicValue);
}
return IntValue.newConstant(basicValue, v1 % v2);
case Opcodes.ISHL:
return IntValue.newConstant(basicValue, v1 << v2);
case Opcodes.ISHR:
return IntValue.newConstant(basicValue, v1 >> v2);
case Opcodes.IUSHR:
return IntValue.newConstant(basicValue, v1 >>> v2);
case Opcodes.IAND:
return IntValue.newConstant(basicValue, v1 & v2);
case Opcodes.IOR:
return IntValue.newConstant(basicValue, v1 | v2);
case Opcodes.IXOR:
return IntValue.newConstant(basicValue, v1 ^ v2);
}
}
return IntValue.newUnknown(basicValue);
return IntValue.newConstant(basicValue, set.build());
}
@Override
@ -188,10 +221,15 @@ public final class IntInterpreter extends Interpreter<IntValue> {
return null;
}
if (value1.isConstant() && value2.isConstant() && value1.getIntValue() == value2.getIntValue()) {
return IntValue.newConstant(basicValue, value1.getIntValue());
if (value1.isUnknown() || value2.isUnknown()) {
return IntValue.newUnknown(basicValue);
}
return IntValue.newUnknown(basicValue);
var set = ImmutableSet.copyOf(Sets.union(value1.getIntValues(), value2.getIntValues()));
if (set.size() > MAX_TRACKED_VALUES) {
return IntValue.newUnknown(basicValue);
}
return IntValue.newConstant(basicValue, set);
}
}

@ -4,39 +4,54 @@ import java.util.Objects;
import com.google.common.base.MoreObjects;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableSet;
import org.objectweb.asm.tree.analysis.BasicValue;
import org.objectweb.asm.tree.analysis.Value;
public final class IntValue implements Value {
public static IntValue newConstant(BasicValue basicValue, int intValue) {
return newConstant(basicValue, ImmutableSet.of(intValue));
}
public static IntValue newConstant(BasicValue basicValue, ImmutableSet<Integer> intValues) {
Preconditions.checkArgument(basicValue == BasicValue.INT_VALUE);
return new IntValue(basicValue, intValue);
Preconditions.checkArgument(!intValues.isEmpty());
return new IntValue(basicValue, intValues);
}
public static IntValue newUnknown(BasicValue basicValue) {
Preconditions.checkNotNull(basicValue);
return new IntValue(basicValue, null);
return new IntValue(basicValue, ImmutableSet.of());
}
private final BasicValue basicValue;
private final Integer intValue;
private final ImmutableSet<Integer> intValues;
private IntValue(BasicValue basicValue, Integer intValue) {
private IntValue(BasicValue basicValue, ImmutableSet<Integer> intValues) {
this.basicValue = basicValue;
this.intValue = intValue;
this.intValues = intValues;
}
public BasicValue getBasicValue() {
return basicValue;
}
public boolean isConstant() {
return intValue != null;
public boolean isUnknown() {
return intValues.isEmpty();
}
public boolean isSingleConstant() {
return intValues.size() == 1;
}
public int getIntValue() {
Preconditions.checkState(intValue != null);
return intValue;
Preconditions.checkState(isSingleConstant());
return intValues.iterator().next();
}
public ImmutableSet<Integer> getIntValues() {
Preconditions.checkArgument(!isUnknown());
return intValues;
}
@Override
@ -54,19 +69,19 @@ public final class IntValue implements Value {
}
IntValue intValue1 = (IntValue) o;
return basicValue.equals(intValue1.basicValue) &&
Objects.equals(intValue, intValue1.intValue);
Objects.equals(intValues, intValue1.intValues);
}
@Override
public int hashCode() {
return Objects.hash(basicValue, intValue);
return Objects.hash(basicValue, intValues);
}
@Override
public String toString() {
return MoreObjects.toStringHelper(this)
.add("basicValue", basicValue)
.add("intValue", intValue)
.add("intValues", intValues)
.toString();
}
}

@ -1,11 +1,15 @@
package dev.openrs2.deob.transform;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import com.google.common.base.Preconditions;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Multimap;
import dev.openrs2.asm.InsnNodeUtils;
import dev.openrs2.asm.MemberRef;
@ -58,6 +62,39 @@ public final class DummyTransformer extends Transformer {
}
}
private enum BranchResult {
ALWAYS_TAKEN,
NEVER_TAKEN,
UNKNOWN;
public static BranchResult fromTakenNotTaken(int taken, int notTaken) {
Preconditions.checkArgument(taken != 0 || notTaken != 0);
if (taken == 0) {
return NEVER_TAKEN;
} else if (notTaken == 0) {
return ALWAYS_TAKEN;
} else {
return UNKNOWN;
}
}
}
private static BranchResult evaluateUnaryBranch(int opcode, Set<Integer> values) {
Preconditions.checkArgument(!values.isEmpty());
int taken = 0, notTaken = 0;
for (var v : values) {
if (evaluateUnaryBranch(opcode, v)) {
taken++;
} else {
notTaken++;
}
}
return BranchResult.fromTakenNotTaken(taken, notTaken);
}
private static boolean evaluateUnaryBranch(int opcode, int value) {
switch (opcode) {
case Opcodes.IFEQ:
@ -69,6 +106,23 @@ public final class DummyTransformer extends Transformer {
}
}
private static BranchResult evaluateBinaryBranch(int opcode, Set<Integer> values1, Set<Integer> values2) {
Preconditions.checkArgument(!values1.isEmpty() && !values2.isEmpty());
int taken = 0, notTaken = 0;
for (var v1 : values1) {
for (var v2 : values2) {
if (evaluateBinaryBranch(opcode, v1, v2)) {
taken++;
} else {
notTaken++;
}
}
}
return BranchResult.fromTakenNotTaken(taken, notTaken);
}
private static boolean evaluateBinaryBranch(int opcode, int value1, int value2) {
switch (opcode) {
case Opcodes.IF_ICMPEQ:
@ -88,8 +142,27 @@ public final class DummyTransformer extends Transformer {
}
}
private static ImmutableSet<Integer> union(Collection<IntValue> intValues) {
var builder = ImmutableSet.<Integer>builder();
for (var value : intValues) {
if (value.isUnknown()) {
return null;
}
builder.addAll(value.getIntValues());
}
var set = builder.build();
if (set.isEmpty()) {
return null;
}
return set;
}
private final Multimap<ArgRef, IntValue> argValues = HashMultimap.create();
private final Map<DisjointSet.Partition<MemberRef>, Integer[]> constArgs = new HashMap<>();
private final Map<DisjointSet.Partition<MemberRef>, ImmutableSet<Integer>[]> constArgs = new HashMap<>();
private DisjointSet<MemberRef> inheritedMethodSets;
private int loadsInlined, branchesSimplified;
@ -153,7 +226,7 @@ public final class DummyTransformer extends Transformer {
case Opcodes.ILOAD:
var iload = (VarInsnNode) insn;
var value = frame.getLocal(iload.var);
if (value.isConstant()) {
if (value.isSingleConstant()) {
method.instructions.set(insn, InsnNodeUtils.createIntConstant(value.getIntValue()));
loadsInlined++;
changed = true;
@ -162,15 +235,18 @@ public final class DummyTransformer extends Transformer {
case Opcodes.IFEQ:
case Opcodes.IFNE:
value = frame.getStack(stackSize - 1);
if (!value.isConstant()) {
if (value.isUnknown()) {
continue;
}
var taken = evaluateUnaryBranch(insn.getOpcode(), value.getIntValue());
if (taken) {
var result = evaluateUnaryBranch(insn.getOpcode(), value.getIntValues());
switch (result) {
case ALWAYS_TAKEN:
alwaysTakenUnaryBranches.add((JumpInsnNode) insn);
} else {
break;
case NEVER_TAKEN:
neverTakenUnaryBranches.add((JumpInsnNode) insn);
break;
}
break;
case Opcodes.IF_ICMPEQ:
@ -180,20 +256,19 @@ public final class DummyTransformer extends Transformer {
case Opcodes.IF_ICMPGT:
case Opcodes.IF_ICMPLE:
var value1 = frame.getStack(stackSize - 2);
if (!value1.isConstant()) {
continue;
}
var value2 = frame.getStack(stackSize - 1);
if (!value2.isConstant()) {
if (value1.isUnknown() || value2.isUnknown()) {
continue;
}
taken = evaluateBinaryBranch(insn.getOpcode(), value1.getIntValue(), value2.getIntValue());
if (taken) {
result = evaluateBinaryBranch(insn.getOpcode(), value1.getIntValues(), value2.getIntValues());
switch (result) {
case ALWAYS_TAKEN:
alwaysTakenBinaryBranches.add((JumpInsnNode) insn);
} else {
break;
case NEVER_TAKEN:
neverTakenBinaryBranches.add((JumpInsnNode) insn);
break;
}
break;
}
@ -235,17 +310,10 @@ public final class DummyTransformer extends Transformer {
for (var method : inheritedMethodSets) {
var args = (Type.getArgumentsAndReturnSizes(method.iterator().next().getDesc()) >> 2) - 1;
var parameters = new Integer[args];
@SuppressWarnings("unchecked")
var parameters = (ImmutableSet<Integer>[]) new ImmutableSet<?>[args];
for (int i = 0; i < args; i++) {
var values = argValues.get(new ArgRef(method, i));
if (values.size() != 1) {
continue;
}
var value = values.iterator().next();
if (value.isConstant()) {
parameters[i] = value.getIntValue();
}
parameters[i] = union(argValues.get(new ArgRef(method, i)));
}
constArgs.put(method, parameters);
}

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