Account for exceptional control flow in not-null analysis
Bug: 180121974
Change-Id: I8c6d15c4d6466dd838670bf0f79fa87052cbccb0
diff --git a/src/main/java/com/android/tools/r8/ir/optimize/info/MethodOptimizationInfoCollector.java b/src/main/java/com/android/tools/r8/ir/optimize/info/MethodOptimizationInfoCollector.java
index 3aaba06..7432e43 100644
--- a/src/main/java/com/android/tools/r8/ir/optimize/info/MethodOptimizationInfoCollector.java
+++ b/src/main/java/com/android/tools/r8/ir/optimize/info/MethodOptimizationInfoCollector.java
@@ -1248,10 +1248,29 @@
// Collect basic blocks that check nullability of the parameter.
Set<BasicBlock> nullCheckedBlocks = Sets.newIdentityHashSet();
for (Instruction user : value.aliasedUsers()) {
- if (user.isAssumeWithNonNullAssumption()
- || user.throwsNpeIfValueIsNull(value, appView, code.context())) {
+ if (user.isAssumeWithNonNullAssumption()) {
+ // We don't allow assume instructions after throwing instructions, thus this block is either
+ // non-throwing or the assume instruction is before the throwing instruction.
+ assert !user.getBlock().hasCatchHandlers()
+ || user.getBlock().getInstructions().stream()
+ .filter(
+ instruction -> instruction == user || instruction.instructionTypeCanThrow())
+ .findFirst()
+ .get()
+ == user;
nullCheckedBlocks.add(user.getBlock());
+ continue;
}
+
+ if (user.throwsNpeIfValueIsNull(value, appView, code.context())) {
+ if (user.getBlock().hasCatchHandlers()) {
+ nullCheckedBlocks.addAll(user.getBlock().getNormalSuccessors());
+ } else {
+ nullCheckedBlocks.add(user.getBlock());
+ }
+ continue;
+ }
+
if (user.isIf()
&& user.asIf().isZeroTest()
&& (user.asIf().getType() == If.Type.EQ || user.asIf().getType() == If.Type.NE)) {
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/nonnull/NullCheckWithCatchHandlerTest.java b/src/test/java/com/android/tools/r8/ir/optimize/nonnull/NullCheckWithCatchHandlerTest.java
new file mode 100644
index 0000000..3e58794
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/nonnull/NullCheckWithCatchHandlerTest.java
@@ -0,0 +1,56 @@
+// Copyright (c) 2021, 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.optimize.nonnull;
+
+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 NullCheckWithCatchHandlerTest extends TestBase {
+
+ private final TestParameters parameters;
+
+ @Parameterized.Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ public NullCheckWithCatchHandlerTest(TestParameters parameters) {
+ this.parameters = parameters;
+ }
+
+ @Test
+ public void test() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .addKeepMainRule(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .compile()
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithEmptyOutput();
+ }
+
+ static class Main {
+
+ public static void main(String[] args) {
+ Object alwaysNull = System.currentTimeMillis() > 0 ? null : new Object();
+ notNullCheck(alwaysNull);
+ if (alwaysNull != null) {
+ System.out.println(alwaysNull.toString());
+ }
+ }
+
+ private static void notNullCheck(Object o) {
+ try {
+ o.getClass();
+ } catch (Throwable e) {
+ }
+ }
+ }
+}
