Refactor in-flow computation in code scanner
Bug: b/296030319
Change-Id: I7374afbecbc5ef5cc061c0de49361a8a9f44a8b3
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/ArgumentPropagatorCodeScanner.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/ArgumentPropagatorCodeScanner.java
index 7cfd03a..5ec5473 100644
--- a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/ArgumentPropagatorCodeScanner.java
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/ArgumentPropagatorCodeScanner.java
@@ -7,6 +7,7 @@
import com.android.tools.r8.errors.Unreachable;
import com.android.tools.r8.graph.AppView;
import com.android.tools.r8.graph.DexClassAndMethod;
+import com.android.tools.r8.graph.DexField;
import com.android.tools.r8.graph.DexMethod;
import com.android.tools.r8.graph.DexMethodHandle;
import com.android.tools.r8.graph.DexType;
@@ -16,7 +17,6 @@
import com.android.tools.r8.ir.analysis.type.DynamicType;
import com.android.tools.r8.ir.analysis.type.DynamicTypeWithUpperBound;
import com.android.tools.r8.ir.analysis.type.Nullability;
-import com.android.tools.r8.ir.analysis.type.TypeElement;
import com.android.tools.r8.ir.analysis.value.AbstractValue;
import com.android.tools.r8.ir.analysis.value.objectstate.ObjectState;
import com.android.tools.r8.ir.code.AbstractValueSupplier;
@@ -30,6 +30,8 @@
import com.android.tools.r8.ir.code.InvokeMethod;
import com.android.tools.r8.ir.code.InvokeMethodWithReceiver;
import com.android.tools.r8.ir.code.Value;
+import com.android.tools.r8.optimize.argumentpropagation.codescanner.AbstractFunction;
+import com.android.tools.r8.optimize.argumentpropagation.codescanner.BaseInFlow;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.ConcreteArrayTypeValueState;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.ConcreteClassTypeValueState;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.ConcreteMonomorphicMethodState;
@@ -41,7 +43,6 @@
import com.android.tools.r8.optimize.argumentpropagation.codescanner.ConcreteReceiverValueState;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.ConcreteValueState;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.FieldStateCollection;
-import com.android.tools.r8.optimize.argumentpropagation.codescanner.FieldValue;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.FieldValueFactory;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.InFlow;
import com.android.tools.r8.optimize.argumentpropagation.codescanner.MethodParameter;
@@ -142,12 +143,19 @@
return virtualRootMethods.get(method.getReference());
}
+ // TODO(b/296030319): Allow lookups in the FieldStateCollection using DexField keys to avoid the
+ // need for definitionFor here.
+ private boolean isFieldValueAlreadyUnknown(DexField field) {
+ return isFieldValueAlreadyUnknown(appView.definitionFor(field).asProgramField());
+ }
+
private boolean isFieldValueAlreadyUnknown(ProgramField field) {
return fieldStates.get(field).isUnknown();
}
protected boolean isMethodParameterAlreadyUnknown(
MethodParameter methodParameter, ProgramMethod method) {
+ assert methodParameter.getMethod().isIdenticalTo(method.getReference());
MethodState methodState =
methodStates.get(
method.getDefinition().belongsToDirectPool() || isMonomorphicVirtualMethod(method)
@@ -248,33 +256,9 @@
ProgramField field,
AbstractValueSupplier abstractValueSupplier,
ProgramMethod context) {
- Value valueRoot = fieldPut.value().getAliasedValue(aliasedValueConfiguration);
- InFlow inFlow = null;
- if (valueRoot.isArgument()) {
- // If the value is an argument of the enclosing method, then clearly we have no information
- // about its abstract value. Instead of treating this as having an unknown runtime value, we
- // instead record a flow constraint that specifies that all values that flow into the
- // parameter of this enclosing method also flows into the current field.
- MethodParameter inParameter =
- methodParameterFactory.create(context, valueRoot.getDefinition().asArgument().getIndex());
- if (isMethodParameterAlreadyUnknown(inParameter, context)) {
- return ValueState.unknown();
- }
- inFlow = inParameter;
- } else if (valueRoot.isDefinedByInstructionSatisfying(Instruction::isFieldGet)) {
- FieldGet fieldGet = valueRoot.getDefinition().asFieldGet();
- ProgramField otherField = fieldGet.resolveField(appView, context).getProgramField();
- if (otherField != null) {
- FieldValue fieldValue = fieldValueFactory.create(otherField);
- if (isFieldValueAlreadyUnknown(otherField)) {
- return ValueState.unknown();
- }
- inFlow = fieldValue;
- }
- }
-
- if (inFlow != null) {
- return ConcreteValueState.create(field.getType(), inFlow);
+ NonEmptyValueState inFlowState = computeInFlowState(field.getType(), fieldPut.value(), context);
+ if (inFlowState != null) {
+ return inFlowState;
}
if (field.getType().isArrayType()) {
@@ -298,6 +282,53 @@
}
}
+ // If the value is an argument of the enclosing method or defined by a field-get, then clearly we
+ // have no information about its abstract value (yet). Instead of treating this as having an
+ // unknown runtime value, we instead record a flow constraint.
+ private InFlow computeInFlow(Value value, ProgramMethod context) {
+ Value valueRoot = value.getAliasedValue(aliasedValueConfiguration);
+ if (valueRoot.isArgument()) {
+ MethodParameter inParameter =
+ methodParameterFactory.create(context, valueRoot.getDefinition().asArgument().getIndex());
+ return widenBaseInFlow(inParameter, context);
+ } else if (valueRoot.isDefinedByInstructionSatisfying(Instruction::isFieldGet)) {
+ FieldGet fieldGet = valueRoot.getDefinition().asFieldGet();
+ ProgramField field = fieldGet.resolveField(appView, context).getProgramField();
+ if (field == null) {
+ return null;
+ }
+ return widenBaseInFlow(fieldValueFactory.create(field), context);
+ }
+ return null;
+ }
+
+ private InFlow widenBaseInFlow(BaseInFlow inFlow, ProgramMethod context) {
+ if (inFlow.isFieldValue()) {
+ if (isFieldValueAlreadyUnknown(inFlow.asFieldValue().getField())) {
+ return AbstractFunction.unknown();
+ }
+ } else {
+ assert inFlow.isMethodParameter();
+ if (isMethodParameterAlreadyUnknown(inFlow.asMethodParameter(), context)) {
+ return AbstractFunction.unknown();
+ }
+ }
+ return inFlow;
+ }
+
+ private NonEmptyValueState computeInFlowState(
+ DexType staticType, Value value, ProgramMethod context) {
+ InFlow inFlow = computeInFlow(value, context);
+ if (inFlow == null) {
+ return null;
+ }
+ if (inFlow.isUnknownAbstractFunction()) {
+ return ValueState.unknown();
+ }
+ assert inFlow.isBaseInFlow();
+ return ConcreteValueState.create(staticType, inFlow);
+ }
+
// Strengthens the abstract value of static final fields to a (self-)SingleFieldValue when the
// abstract value is unknown. The soundness of this is based on the fact that static final fields
// will never have their value changed after the <clinit> finishes, so value in a static final
@@ -677,41 +708,17 @@
return ValueState.unknown();
}
- Value argumentRoot = argument.getAliasedValue(aliasedValueConfiguration);
DexType parameterType =
invoke.getInvokedMethod().getArgumentType(argumentIndex, invoke.isInvokeStatic());
- TypeElement parameterTypeElement = parameterType.toTypeElement(appView);
// If the value is an argument of the enclosing method, then clearly we have no information
// about its abstract value. Instead of treating this as having an unknown runtime value, we
// instead record a flow constraint that specifies that all values that flow into the parameter
// of this enclosing method also flows into the corresponding parameter of the methods
// potentially called from this invoke instruction.
- InFlow inFlow = null;
- if (argumentRoot.isArgument()) {
- MethodParameter forwardedParameter =
- methodParameterFactory.create(
- context, argumentRoot.getDefinition().asArgument().getIndex());
- if (isMethodParameterAlreadyUnknown(forwardedParameter, context)) {
- return ValueState.unknown();
- }
- inFlow = forwardedParameter;
- } else if (argumentRoot.isDefinedByInstructionSatisfying(Instruction::isFieldGet)) {
- // If the value is defined by a program field read, then record a flow constraint that
- // specifies that all values that flow into the field also flows into the current parameter of
- // this invoke instruction.
- FieldGet fieldGet = argumentRoot.getDefinition().asFieldGet();
- ProgramField field = fieldGet.resolveField(appView, context).getProgramField();
- if (field != null) {
- if (isFieldValueAlreadyUnknown(field)) {
- return ValueState.unknown();
- }
- inFlow = fieldValueFactory.create(field);
- }
- }
-
- if (inFlow != null) {
- return ConcreteValueState.create(parameterType, inFlow);
+ NonEmptyValueState inFlowState = computeInFlowState(parameterType, argument, context);
+ if (inFlowState != null) {
+ return inFlowState;
}
// Only track the nullability for array types.
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/BaseInFlow.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/BaseInFlow.java
new file mode 100644
index 0000000..20ec5c7
--- /dev/null
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/BaseInFlow.java
@@ -0,0 +1,17 @@
+// Copyright (c) 2024, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+package com.android.tools.r8.optimize.argumentpropagation.codescanner;
+
+public interface BaseInFlow extends InFlow {
+
+ @Override
+ default boolean isBaseInFlow() {
+ return true;
+ }
+
+ @Override
+ default BaseInFlow asBaseInFlow() {
+ return this;
+ }
+}
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/FieldValue.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/FieldValue.java
index 24ad150..b049381 100644
--- a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/FieldValue.java
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/FieldValue.java
@@ -7,7 +7,7 @@
// TODO(b/296030319): Change DexField to implement InFlow and use DexField in all places instead of
// FieldValue to avoid wrappers? This would also remove the need for the FieldValueFactory.
-public class FieldValue implements InFlow {
+public class FieldValue implements BaseInFlow {
private final DexField field;
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/InFlow.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/InFlow.java
index d858bef..3cb0550 100644
--- a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/InFlow.java
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/InFlow.java
@@ -15,6 +15,14 @@
return null;
}
+ default boolean isBaseInFlow() {
+ return false;
+ }
+
+ default BaseInFlow asBaseInFlow() {
+ return null;
+ }
+
default boolean isFieldValue() {
return false;
}
@@ -31,6 +39,10 @@
return null;
}
+ default boolean isUnknownAbstractFunction() {
+ return false;
+ }
+
default boolean isUpdateChangedFlagsAbstractFunction() {
return false;
}
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/MethodParameter.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/MethodParameter.java
index 9bfeab7..2fe1a2a 100644
--- a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/MethodParameter.java
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/MethodParameter.java
@@ -7,7 +7,7 @@
import com.android.tools.r8.graph.DexMethod;
import java.util.Objects;
-public class MethodParameter implements InFlow {
+public class MethodParameter implements BaseInFlow {
private final DexMethod method;
private final int index;
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/UnknownAbstractFunction.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/UnknownAbstractFunction.java
index 8ac1736..ccddf4d 100644
--- a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/UnknownAbstractFunction.java
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/UnknownAbstractFunction.java
@@ -24,4 +24,9 @@
public InFlow getBaseInFlow() {
throw new Unreachable();
}
+
+ @Override
+ public boolean isUnknownAbstractFunction() {
+ return true;
+ }
}
