Merge "Add checker for inefficient Parcel usage." (3f9f18ea) · Commits · e / os / android_frameworks_base

errorprone/java/com/google/errorprone/bugpatterns/android/ParcelablePerformanceChecker.java

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		/*
		* Copyright (C) 2020 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.google.errorprone.bugpatterns.android;

		import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
		import static com.google.errorprone.matchers.Matchers.allOf;
		import static com.google.errorprone.matchers.Matchers.enclosingClass;
		import static com.google.errorprone.matchers.Matchers.enclosingMethod;
		import static com.google.errorprone.matchers.Matchers.instanceMethod;
		import static com.google.errorprone.matchers.Matchers.isSubtypeOf;
		import static com.google.errorprone.matchers.Matchers.methodInvocation;
		import static com.google.errorprone.matchers.Matchers.methodIsNamed;

		import com.google.auto.service.AutoService;
		import com.google.errorprone.BugPattern;
		import com.google.errorprone.VisitorState;
		import com.google.errorprone.bugpatterns.BugChecker;
		import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
		import com.google.errorprone.matchers.Description;
		import com.google.errorprone.matchers.Matcher;
		import com.sun.source.tree.ExpressionTree;
		import com.sun.source.tree.MethodInvocationTree;
		import com.sun.source.tree.Tree;

		/**
		* Parcelable data can be transported in many ways (some of which can be very
		* inefficient) so this checker guides developers towards using high-performance
		* best-practices.
		*/
		@AutoService(BugChecker.class)
		@BugPattern(
		name = "AndroidFrameworkParcelablePerformance",
		summary = "Verifies Parcelable performance best-practices",
		severity = WARNING)
		public final class ParcelablePerformanceChecker extends BugChecker
		implements MethodInvocationTreeMatcher {
		private static final Matcher<Tree> INSIDE_WRITE_TO_PARCEL = allOf(
		enclosingClass(isSubtypeOf("android.os.Parcelable")),
		enclosingMethod(methodIsNamed("writeToParcel")));

		private static final Matcher<ExpressionTree> WRITE_STRING = methodInvocation(
		instanceMethod().onExactClass("android.os.Parcel").named("writeString"));
		private static final Matcher<ExpressionTree> WRITE_STRING_ARRAY = methodInvocation(
		instanceMethod().onExactClass("android.os.Parcel").named("writeStringArray"));

		private static final Matcher<ExpressionTree> WRITE_VALUE = methodInvocation(
		instanceMethod().onExactClass("android.os.Parcel").named("writeValue"));
		private static final Matcher<ExpressionTree> WRITE_PARCELABLE = methodInvocation(
		instanceMethod().onExactClass("android.os.Parcel").named("writeParcelable"));

		private static final Matcher<ExpressionTree> WRITE_LIST = methodInvocation(
		instanceMethod().onExactClass("android.os.Parcel").named("writeList"));
		private static final Matcher<ExpressionTree> WRITE_PARCELABLE_LIST = methodInvocation(
		instanceMethod().onExactClass("android.os.Parcel").named("writeParcelableList"));
		private static final Matcher<ExpressionTree> WRITE_PARCELABLE_ARRAY = methodInvocation(
		instanceMethod().onExactClass("android.os.Parcel").named("writeParcelableArray"));

		@Override
		public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
		if (INSIDE_WRITE_TO_PARCEL.matches(tree, state)) {
		if (WRITE_STRING.matches(tree, state)) {
		return buildDescription(tree)
		.setMessage("Recommended to use 'writeString8()' to improve "
		+ "efficiency; sending as UTF-8 can double throughput")
		.build();
		}
		if (WRITE_STRING_ARRAY.matches(tree, state)) {
		return buildDescription(tree)
		.setMessage("Recommended to use 'writeString8Array()' to improve "
		+ "efficiency; sending as UTF-8 can double throughput")
		.build();
		}

		if (WRITE_VALUE.matches(tree, state)) {
		return buildDescription(tree)
		.setMessage("Recommended to use strongly-typed methods to improve "
		+ "efficiency; saves 4 bytes for type and overhead of "
		+ "Parcelable class name")
		.build();
		}
		if (WRITE_PARCELABLE.matches(tree, state)) {
		return buildDescription(tree)
		.setMessage("Recommended to use 'item.writeToParcel()' to improve "
		+ "efficiency; saves overhead of Parcelable class name")
		.build();
		}

		if (WRITE_LIST.matches(tree, state)) {
		return buildDescription(tree)
		.setMessage("Recommended to use 'writeTypedList()' to improve "
		+ "efficiency; saves overhead of repeated Parcelable class name")
		.build();
		}
		if (WRITE_PARCELABLE_LIST.matches(tree, state)) {
		return buildDescription(tree)
		.setMessage("Recommended to use 'writeTypedList()' to improve "
		+ "efficiency; saves overhead of repeated Parcelable class name")
		.build();
		}
		if (WRITE_PARCELABLE_ARRAY.matches(tree, state)) {
		return buildDescription(tree)
		.setMessage("Recommended to use 'writeTypedArray()' to improve "
		+ "efficiency; saves overhead of repeated Parcelable class name")
		.build();
		}
		}
		return Description.NO_MATCH;
		}
		}

errorprone/tests/java/com/google/errorprone/bugpatterns/android/ParcelablePerformanceCheckerTest.java

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		/*
		* Copyright (C) 2020 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.google.errorprone.bugpatterns.android;

		import com.google.errorprone.CompilationTestHelper;

		import org.junit.Before;
		import org.junit.Test;
		import org.junit.runner.RunWith;
		import org.junit.runners.JUnit4;

		@RunWith(JUnit4.class)
		public class ParcelablePerformanceCheckerTest {
		private CompilationTestHelper compilationHelper;

		@Before
		public void setUp() {
		compilationHelper = CompilationTestHelper.newInstance(
		ParcelablePerformanceChecker.class, getClass());
		}

		@Test
		public void testString() {
		compilationHelper
		.addSourceFile("/android/os/Parcel.java")
		.addSourceFile("/android/os/Parcelable.java")
		.addSourceLines("FooInfo.java",
		"import android.os.Parcel;",
		"import android.os.Parcelable;",
		"public class FooInfo implements Parcelable {",
		" public void writeToParcel(Parcel dest, int flags) {",
		" // BUG: Diagnostic contains:",
		" dest.writeString(toString());",
		" dest.writeString8(toString());",
		" // BUG: Diagnostic contains:",
		" dest.writeStringArray(new String[0]);",
		" dest.writeString8Array(new String[0]);",
		" }",
		"}")
		.doTest();
		}

		@Test
		public void testSingle() {
		compilationHelper
		.addSourceFile("/android/os/Parcel.java")
		.addSourceFile("/android/os/Parcelable.java")
		.addSourceLines("FooInfo.java",
		"import android.os.Parcel;",
		"import android.os.Parcelable;",
		"public class FooInfo implements Parcelable {",
		" public void writeToParcel(Parcel dest, int flags) {",
		" // BUG: Diagnostic contains:",
		" dest.writeValue(this);",
		" this.writeToParcel(dest, flags);",
		" // BUG: Diagnostic contains:",
		" dest.writeParcelable(this, flags);",
		" this.writeToParcel(dest, flags);",
		" }",
		"}")
		.doTest();
		}

		@Test
		public void testList() {
		compilationHelper
		.addSourceFile("/android/os/Parcel.java")
		.addSourceFile("/android/os/Parcelable.java")
		.addSourceLines("FooInfo.java",
		"import android.os.Parcel;",
		"import android.os.Parcelable;",
		"import java.util.List;",
		"import java.util.ArrayList;",
		"public class FooInfo implements Parcelable {",
		" public void writeToParcel(Parcel dest, int flags) {",
		" List<Parcelable> list = new ArrayList<Parcelable>();",
		" Parcelable[] array = new Parcelable[0];",
		" // BUG: Diagnostic contains:",
		" dest.writeList(list);",
		" dest.writeTypedList(list, flags);",
		" // BUG: Diagnostic contains:",
		" dest.writeParcelableList(list, flags);",
		" dest.writeTypedList(list, flags);",
		" // BUG: Diagnostic contains:",
		" dest.writeParcelableArray(array, flags);",
		" dest.writeTypedArray(array, flags);",
		" }",
		"}")
		.doTest();
		}
		}

errorprone/tests/res/android/os/Parcel.java

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		/*
		* Copyright (C) 2020 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package android.os;

		import java.util.List;

		public class Parcel {
		public void writeString(String val) {
		throw new UnsupportedOperationException();
		}
		public void writeString8(String val) {
		throw new UnsupportedOperationException();
		}
		public final void writeStringArray(String[] val) {
		throw new UnsupportedOperationException();
		}
		public final void writeString8Array(String[] val) {
		throw new UnsupportedOperationException();
		}

		public final void writeValue(Object v) {
		throw new UnsupportedOperationException();
		}
		public final void writeParcelable(Parcelable p, int flags) {
		throw new UnsupportedOperationException();
		}

		public final void writeList(List val) {
		throw new UnsupportedOperationException();
		}
		public final <T extends Parcelable> void writeParcelableList(List<T> val, int flags) {
		throw new UnsupportedOperationException();
		}
		public <T extends Parcelable> void writeTypedList(List<T> val, int flags) {
		throw new UnsupportedOperationException();
		}
		public final <T extends Parcelable> void writeParcelableArray(T[] value, int flags) {
		throw new UnsupportedOperationException();
		}
		public final <T extends Parcelable> void writeTypedArray(T[] val, int flags) {
		throw new UnsupportedOperationException();
		}
		}

errorprone/tests/res/android/os/Parcelable.java

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		/*
		* Copyright (C) 2020 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package android.os;

		public interface Parcelable {
		public void writeToParcel(Parcel dest, int flags);
		}