Add tests for using String.concat instead of StringBuilder
Bug: b/129200243
Change-Id: I16ddcef8b2ae815587ed12f0347d14e70c9c2691
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendAppendNotNullTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendAppendNotNullTest.java
new file mode 100644
index 0000000..5cde367
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendAppendNotNullTest.java
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatAppendAppendNotNullTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(2, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : null;
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : "o";
+ System.out.println(new StringBuilder().append(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendAppendTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendAppendTest.java
new file mode 100644
index 0000000..3840d75
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendAppendTest.java
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatAppendAppendTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(2, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : null;
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : null;
+ System.out.println(new StringBuilder().append(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendConstantAppendNotNullTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendConstantAppendNotNullTest.java
new file mode 100644
index 0000000..d4ac494
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendConstantAppendNotNullTest.java
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatAppendNotNullAppendConstantAppendNotNullTest extends TestBase {
+
+ private static final String EXPECTED = "oko";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ // TODO(b/129200243): Should only have two appends.
+ assertEquals(3, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg = System.currentTimeMillis() > 0 ? "o" : "";
+ System.out.println(new StringBuilder().append(arg).append("k").append(arg).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendNotNullTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendNotNullTest.java
new file mode 100644
index 0000000..c28729a
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendNotNullTest.java
@@ -0,0 +1,69 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatAppendNotNullAppendNotNullTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): Should be String.concat.
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(2, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : "";
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : "";
+ System.out.println(new StringBuilder().append(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendTest.java
new file mode 100644
index 0000000..21b61f3
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullAppendTest.java
@@ -0,0 +1,69 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatAppendNotNullAppendTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): See if this can be arg1.concat(String.valueOf(arg2))
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(2, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : "";
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : null;
+ System.out.println(new StringBuilder().append(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullTest.java
new file mode 100644
index 0000000..d2c95ab
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendNotNullTest.java
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatAppendNotNullTest extends TestBase {
+
+ private static final String EXPECTED = "o";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): This should just be arg.toString()
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg = System.currentTimeMillis() > 0 ? "o" : "";
+ System.out.println(new StringBuilder().append(arg).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendTest.java
new file mode 100644
index 0000000..534591f
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatAppendTest.java
@@ -0,0 +1,67 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatAppendTest extends TestBase {
+
+ private static final String EXPECTED = "o";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg = System.currentTimeMillis() > 0 ? "o" : null;
+ System.out.println(new StringBuilder().append(arg).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatConstantInitTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatConstantInitTest.java
new file mode 100644
index 0000000..9b9280f
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatConstantInitTest.java
@@ -0,0 +1,71 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatConstantInitTest extends TestBase {
+
+ private static final String EXPECTED = "oko";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): Should be String.concat.
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg = System.currentTimeMillis() > 0 ? "o" : null;
+ if (arg != null) {
+ // The optimization should join "ok" into init and then append with arg.
+ System.out.println(new StringBuilder("o").append("k").append(arg).toString());
+ }
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatImplicitToStringConcatTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatImplicitToStringConcatTest.java
new file mode 100644
index 0000000..a2eb814
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatImplicitToStringConcatTest.java
@@ -0,0 +1,71 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatImplicitToStringConcatTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): This should be String.concat() as argument.
+ assertEquals(2, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : null;
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : null;
+ if (arg1 != null && arg2 != null) {
+ System.out.println(new StringBuilder(new StringBuilder(arg1).append(arg2)).toString());
+ }
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatImplicitToStringSingleTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatImplicitToStringSingleTest.java
new file mode 100644
index 0000000..a3eb034
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatImplicitToStringSingleTest.java
@@ -0,0 +1,70 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatImplicitToStringSingleTest extends TestBase {
+
+ private static final String EXPECTED = "o";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): Use the arg string directly as input.
+ assertEquals(2, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(0, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg = System.currentTimeMillis() > 0 ? "o" : null;
+ if (arg != null) {
+ System.out.println(new StringBuilder(new StringBuilder(arg)).toString());
+ }
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitAppendNotNullTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitAppendNotNullTest.java
new file mode 100644
index 0000000..3f6f896
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitAppendNotNullTest.java
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatInitAppendNotNullTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : null;
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : "";
+ System.out.println(new StringBuilder(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitAppendTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitAppendTest.java
new file mode 100644
index 0000000..d7ace15
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitAppendTest.java
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatInitAppendTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : null;
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : null;
+ System.out.println(new StringBuilder(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullAppendNotNullTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullAppendNotNullTest.java
new file mode 100644
index 0000000..4dce8fd
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullAppendNotNullTest.java
@@ -0,0 +1,69 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatInitNotNullAppendNotNullTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): Should be concat.
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : "";
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : "";
+ System.out.println(new StringBuilder(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullAppendTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullAppendTest.java
new file mode 100644
index 0000000..3579f20
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullAppendTest.java
@@ -0,0 +1,69 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatInitNotNullAppendTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): See if this can be arg1.concat(String.valueOf(arg2))
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(1, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg1 = System.currentTimeMillis() > 0 ? "o" : "";
+ String arg2 = System.currentTimeMillis() > 0 ? "k" : null;
+ System.out.println(new StringBuilder(arg1).append(arg2).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullTest.java
new file mode 100644
index 0000000..690a604
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitNotNullTest.java
@@ -0,0 +1,68 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatInitNotNullTest extends TestBase {
+
+ private static final String EXPECTED = "o";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ // TODO(b/129200243): This should just be the string as is.
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(0, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg = System.currentTimeMillis() > 0 ? "o" : "";
+ System.out.println(new StringBuilder(arg).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitTest.java
new file mode 100644
index 0000000..44aa31b3
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatInitTest.java
@@ -0,0 +1,67 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatInitTest extends TestBase {
+
+ private static final String EXPECTED = "o";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(1, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(0, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ String arg = System.currentTimeMillis() > 0 ? "o" : null;
+ System.out.println(new StringBuilder(arg).toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatNoRewriteConstantsTest.java b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatNoRewriteConstantsTest.java
new file mode 100644
index 0000000..73e61bc
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/StringConcatNoRewriteConstantsTest.java
@@ -0,0 +1,67 @@
+// Copyright (c) 2022, 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.string;
+
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderAppends;
+import static com.android.tools.r8.ir.optimize.string.utils.StringBuilderCodeMatchers.countStringBuilderInits;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.MethodSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class StringConcatNoRewriteConstantsTest extends TestBase {
+
+ private static final String EXPECTED = "ok";
+
+ @Parameter() public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection data() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void testRuntime() throws Exception {
+ testForRuntime(parameters)
+ .addProgramClasses(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED);
+ }
+
+ @Test
+ public void testR8() throws Exception {
+ testForR8(parameters.getBackend())
+ .addProgramClasses(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .addKeepMainRule(Main.class)
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines(EXPECTED)
+ .inspect(
+ inspect -> {
+ MethodSubject methodSubject = inspect.clazz(Main.class).mainMethod();
+ assertThat(methodSubject, isPresent());
+ assertEquals(0, countStringBuilderInits(methodSubject.asFoundMethodSubject()));
+ assertEquals(0, countStringBuilderAppends(methodSubject.asFoundMethodSubject()));
+ });
+ }
+
+ public static class Main {
+
+ public static void main(String[] args) {
+ // Should just be a single constant string without string.concat.
+ System.out.println(new StringBuilder("o").append("k").toString());
+ }
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/ir/optimize/string/utils/StringBuilderCodeMatchers.java b/src/test/java/com/android/tools/r8/ir/optimize/string/utils/StringBuilderCodeMatchers.java
index 08abff5..e60fb1c 100644
--- a/src/test/java/com/android/tools/r8/ir/optimize/string/utils/StringBuilderCodeMatchers.java
+++ b/src/test/java/com/android/tools/r8/ir/optimize/string/utils/StringBuilderCodeMatchers.java
@@ -5,6 +5,7 @@
package com.android.tools.r8.ir.optimize.string.utils;
import com.android.tools.r8.utils.codeinspector.CodeMatchers;
+import com.android.tools.r8.utils.codeinspector.FoundMethodSubject;
import com.android.tools.r8.utils.codeinspector.InstructionSubject;
import java.util.function.Predicate;
@@ -14,4 +15,23 @@
return CodeMatchers.isInvokeWithTarget(
"java.lang.StringBuilder", "java.lang.StringBuilder", "append", "java.lang.String");
}
+
+ public static long countStringBuilderInits(FoundMethodSubject method) {
+ return countInstructionsOnStringBuilder(method, "<init>");
+ }
+
+ public static long countStringBuilderAppends(FoundMethodSubject method) {
+ return countInstructionsOnStringBuilder(method, "append");
+ }
+
+ public static long countInstructionsOnStringBuilder(
+ FoundMethodSubject method, String methodName) {
+ return method
+ .streamInstructions()
+ .filter(
+ instructionSubject ->
+ CodeMatchers.isInvokeWithTarget(StringBuilder.class.getTypeName(), methodName)
+ .test(instructionSubject))
+ .count();
+ }
}
