Version 2.0.76
This version fixes b/157926129. The fix is tailored to 2.0 (thus not a cherry pick), but uses the insights from https://r8-review.googlesource.com/c/r8/+/51854.
Cherry pick: Reproduce stack overflow from mutual recursion in side effect analysis
CL: https://r8-review.googlesource.com/c/r8/+/51853
Bug: 157926129
Change-Id: Ia262e8a4b74a87510b3788229d6f951e558e0174
diff --git a/src/main/java/com/android/tools/r8/Version.java b/src/main/java/com/android/tools/r8/Version.java
index 05557f3..bc99ee3 100644
--- a/src/main/java/com/android/tools/r8/Version.java
+++ b/src/main/java/com/android/tools/r8/Version.java
@@ -11,7 +11,7 @@
// This field is accessed from release scripts using simple pattern matching.
// Therefore, changing this field could break our release scripts.
- public static final String LABEL = "2.0.75";
+ public static final String LABEL = "2.0.76";
private Version() {
}
diff --git a/src/main/java/com/android/tools/r8/ir/code/InvokeDirect.java b/src/main/java/com/android/tools/r8/ir/code/InvokeDirect.java
index 936757f..a52eba7 100644
--- a/src/main/java/com/android/tools/r8/ir/code/InvokeDirect.java
+++ b/src/main/java/com/android/tools/r8/ir/code/InvokeDirect.java
@@ -25,7 +25,6 @@
import com.android.tools.r8.ir.optimize.info.MethodOptimizationInfo;
import com.android.tools.r8.ir.optimize.info.initializer.InstanceInitializerInfo;
import com.android.tools.r8.shaking.AppInfoWithLiveness;
-import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;
@@ -233,48 +232,15 @@
if (instructionMayHaveSideEffects(appView, method.method.holder)) {
return false;
}
-
- if (appView.dexItemFactory().isConstructor(getInvokedMethod())) {
- // If it is a constructor call that initializes an uninitialized object, then the
- // uninitialized object must be dead. This is the case if all the constructor calls cannot
- // have side effects and the instance is dead except for the constructor calls.
- List<Instruction> otherInitCalls = null;
- for (Instruction user : getReceiver().uniqueUsers()) {
- if (user == this) {
- continue;
- }
- if (user.isInvokeDirect()) {
- InvokeDirect invoke = user.asInvokeDirect();
- if (appView.dexItemFactory().isConstructor(invoke.getInvokedMethod())
- && invoke.getReceiver() == getReceiver()) {
- // If another constructor call than `this` is found, then it must not have side effects.
- if (invoke.instructionMayHaveSideEffects(appView, method.method.holder)) {
- return false;
- }
- if (otherInitCalls == null) {
- otherInitCalls = new ArrayList<>();
- }
- otherInitCalls.add(invoke);
- }
- }
- }
-
- // Now check that the instance is dead except for the constructor calls.
- final List<Instruction> finalOtherInitCalls = otherInitCalls;
- Predicate<Instruction> ignoreConstructorCalls =
- instruction ->
- instruction == this
- || (finalOtherInitCalls != null && finalOtherInitCalls.contains(instruction));
- if (!getReceiver().isDead(appView, code, ignoreConstructorCalls)) {
- return false;
- }
-
- // Verify that it is not a super-constructor call (these cannot be removed).
- if (getReceiver().getAliasedValue() == code.getThis()) {
- return false;
- }
+ if (!appView.dexItemFactory().isConstructor(getInvokedMethod())) {
+ return true;
}
-
+ // Super-constructor calls cannot be removed.
+ if (getReceiver().getAliasedValue() == code.getThis()) {
+ return false;
+ }
+ // Constructor calls can only be removed if the receiver is dead. It is the responsibility of
+ // the caller to check this property.
return true;
}
diff --git a/src/main/java/com/android/tools/r8/ir/code/Value.java b/src/main/java/com/android/tools/r8/ir/code/Value.java
index 819e684..bb631c5 100644
--- a/src/main/java/com/android/tools/r8/ir/code/Value.java
+++ b/src/main/java/com/android/tools/r8/ir/code/Value.java
@@ -1057,6 +1057,16 @@
if (!instruction.canBeDeadCode(appView, code)) {
return false;
}
+ if (instruction.isInvokeDirect()) {
+ // Constructor calls can only be removed if the receiver is dead.
+ // This fixes b/157926129, but note that the fix is different in R8 version 2.1 and higher.
+ InvokeDirect invoke = instruction.asInvokeDirect();
+ if (appView.dexItemFactory().isConstructor(invoke.getInvokedMethod())
+ && !active.contains(invoke.getReceiver())
+ && !invoke.getReceiver().isDead(appView, code, ignoreUser, active)) {
+ continue;
+ }
+ }
Value outValue = instruction.outValue();
if (outValue != null
&& !active.contains(outValue)
diff --git a/src/main/java/com/android/tools/r8/ir/optimize/DeadCodeRemover.java b/src/main/java/com/android/tools/r8/ir/optimize/DeadCodeRemover.java
index f94b7a7..716f9e6 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/DeadCodeRemover.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/DeadCodeRemover.java
@@ -14,6 +14,7 @@
import com.android.tools.r8.ir.code.IRCode;
import com.android.tools.r8.ir.code.Instruction;
import com.android.tools.r8.ir.code.InstructionListIterator;
+import com.android.tools.r8.ir.code.InvokeDirect;
import com.android.tools.r8.ir.code.Phi;
import com.android.tools.r8.ir.code.Value;
import com.android.tools.r8.shaking.AppInfoWithLiveness;
@@ -102,6 +103,14 @@
if (!current.canBeDeadCode(appView, code)) {
continue;
}
+ if (current.isInvokeDirect()) {
+ // Constructor calls can only be removed if the receiver is dead.
+ InvokeDirect invoke = current.asInvokeDirect();
+ if (appView.dexItemFactory().isConstructor(invoke.getInvokedMethod())
+ && !invoke.getReceiver().isDead(appView, code)) {
+ continue;
+ }
+ }
Value outValue = current.outValue();
if (outValue != null && !outValue.isDead(appView, code)) {
continue;
diff --git a/src/test/java/com/android/tools/r8/ir/analysis/sideeffect/DeadConstructorWithCycleTest.java b/src/test/java/com/android/tools/r8/ir/analysis/sideeffect/DeadConstructorWithCycleTest.java
new file mode 100644
index 0000000..ef95b71
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/analysis/sideeffect/DeadConstructorWithCycleTest.java
@@ -0,0 +1,69 @@
+// Copyright (c) 2020, 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.ir.analysis.sideeffect;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import com.android.tools.r8.NeverClassInline;
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+@RunWith(Parameterized.class)
+public class DeadConstructorWithCycleTest extends TestBase {
+
+ private final TestParameters parameters;
+
+ @Parameterized.Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ public DeadConstructorWithCycleTest(TestParameters parameters) {
+ this.parameters = parameters;
+ }
+
+ @Test
+ public void test() throws Exception {
+ testForR8(parameters.getBackend())
+ .addInnerClasses(DeadConstructorWithCycleTest.class)
+ .addKeepMainRule(TestClass.class)
+ .enableNeverClassInliningAnnotations()
+ .setMinApi(parameters.getApiLevel())
+ .compile()
+ .inspect(inspector -> assertThat(inspector.clazz(A.class), not(isPresent())))
+ .run(parameters.getRuntime(), TestClass.class)
+ .assertSuccessWithOutput("");
+ }
+
+ static class TestClass {
+
+ public static void main(String[] args) {
+ Object o1 = null;
+ Object o2 = null;
+ for (int i = 1; i <= 2; i++) {
+ o1 = new A(o1, o2);
+ o2 = new A(o1, o2);
+ }
+ }
+ }
+
+ @NeverClassInline
+ static class A {
+
+ Object f1;
+ Object f2;
+
+ A(Object o1, Object o2) {
+ this.f1 = o1;
+ this.f2 = o2;
+ }
+ }
+}
