From ad5cd31498a7d6835957b7fe3a9ece4b12753867 Mon Sep 17 00:00:00 2001 From: Samuel Freilich Date: Tue, 5 Sep 2023 09:47:54 -0400 Subject: [PATCH] Add shrinker-test examples with never-referenced constructors (#2478) * Add shrinker-test examples with never-referenced constructors R8 can do some optimizations that assume values of types whose constructors are never referenced are `null`. (A bit confused why the rules here are sufficient to avoid that optimization in the case of a class whose sole constructor has arguments and is unreferenced, since the keep rule only refers to `()` instead of `(...)`. Does R8 have special behavior for `()` where attempting to keep that makes it assume a class is constructable even if it doesn't have a no-args constructor?) Also rename some test classes/names to refer to `NoArgs` instead of `Default` constructors. The examples here care about whether a no-argument constructor is present. While a no-argument constructor (explicitly defined or not) is used by default in some circumstances, the Java documentation consistently uses "default constructor" to refer only to constructors whose implementation is implicitly provided by the complier (all default constructors are no-argument constructors, but not vice versa). * Update shrinker-test/src/main/java/com/example/ClassWithNoArgsConstructor.java Accept review suggestion Co-authored-by: Marcono1234 * Update shrinker-test/src/main/java/com/example/NoSerializedNameMain.java Accept review suggestion Co-authored-by: Marcono1234 * Further adjust test class/method names for consistency * Update shrinker-test/src/main/java/com/example/NoSerializedNameMain.java Co-authored-by: Marcono1234 --------- Co-authored-by: Marcono1234 --- shrinker-test/common.pro | 4 +- shrinker-test/proguard.pro | 4 +- shrinker-test/r8.pro | 4 +- ....java => ClassWithHasArgsConstructor.java} | 6 +- ...r.java => ClassWithNoArgsConstructor.java} | 6 +- ...assWithUnreferencedHasArgsConstructor.java | 19 ++++++ ...lassWithUnreferencedNoArgsConstructor.java | 18 +++++ .../src/main/java/com/example/Main.java | 65 +++++++++++++++++-- .../com/example/NoSerializedNameMain.java | 26 ++++---- .../java/com/google/gson/it/ShrinkingIT.java | 38 ++++++++--- 10 files changed, 151 insertions(+), 39 deletions(-) rename shrinker-test/src/main/java/com/example/{ClassWithoutDefaultConstructor.java => ClassWithHasArgsConstructor.java} (61%) rename shrinker-test/src/main/java/com/example/{ClassWithDefaultConstructor.java => ClassWithNoArgsConstructor.java} (52%) create mode 100644 shrinker-test/src/main/java/com/example/ClassWithUnreferencedHasArgsConstructor.java create mode 100644 shrinker-test/src/main/java/com/example/ClassWithUnreferencedNoArgsConstructor.java diff --git a/shrinker-test/common.pro b/shrinker-test/common.pro index b30faa13..9995925e 100644 --- a/shrinker-test/common.pro +++ b/shrinker-test/common.pro @@ -16,9 +16,9 @@ public static void runTests(...); } -keep class com.example.NoSerializedNameMain { - public static java.lang.String runTest(); + public static java.lang.String runTestNoArgsConstructor(); public static java.lang.String runTestNoJdkUnsafe(); - public static java.lang.String runTestNoDefaultConstructor(); + public static java.lang.String runTestHasArgsConstructor(); } diff --git a/shrinker-test/proguard.pro b/shrinker-test/proguard.pro index ee960733..7922bc09 100644 --- a/shrinker-test/proguard.pro +++ b/shrinker-test/proguard.pro @@ -6,12 +6,12 @@ # Unlike R8, ProGuard does not perform aggressive optimization which makes classes abstract, # therefore for ProGuard can successfully perform deserialization, and for that need to # preserve the field names --keepclassmembernames class com.example.NoSerializedNameMain$TestClass { +-keepclassmembernames class com.example.NoSerializedNameMain$TestClassNoArgsConstructor { ; } -keepclassmembernames class com.example.NoSerializedNameMain$TestClassNotAbstract { ; } --keepclassmembernames class com.example.NoSerializedNameMain$TestClassWithoutDefaultConstructor { +-keepclassmembernames class com.example.NoSerializedNameMain$TestClassHasArgsConstructor { ; } diff --git a/shrinker-test/r8.pro b/shrinker-test/r8.pro index 01b8c84e..642334d5 100644 --- a/shrinker-test/r8.pro +++ b/shrinker-test/r8.pro @@ -10,8 +10,8 @@ -keep,allowshrinking,allowoptimization,allowobfuscation,allowaccessmodification class com.example.GenericClasses$GenericUsingGenericClass # Don't obfuscate class name, to check it in exception message --keep,allowshrinking,allowoptimization class com.example.NoSerializedNameMain$TestClass --keep,allowshrinking,allowoptimization class com.example.NoSerializedNameMain$TestClassWithoutDefaultConstructor +-keep,allowshrinking,allowoptimization class com.example.NoSerializedNameMain$TestClassNoArgsConstructor +-keep,allowshrinking,allowoptimization class com.example.NoSerializedNameMain$TestClassHasArgsConstructor # This rule has the side-effect that R8 still removes the no-args constructor, but does not make the class abstract -keep class com.example.NoSerializedNameMain$TestClassNotAbstract { diff --git a/shrinker-test/src/main/java/com/example/ClassWithoutDefaultConstructor.java b/shrinker-test/src/main/java/com/example/ClassWithHasArgsConstructor.java similarity index 61% rename from shrinker-test/src/main/java/com/example/ClassWithoutDefaultConstructor.java rename to shrinker-test/src/main/java/com/example/ClassWithHasArgsConstructor.java index 2af57367..c65281e0 100644 --- a/shrinker-test/src/main/java/com/example/ClassWithoutDefaultConstructor.java +++ b/shrinker-test/src/main/java/com/example/ClassWithHasArgsConstructor.java @@ -3,15 +3,15 @@ package com.example; import com.google.gson.annotations.SerializedName; /** - * Class without no-args default constructor, but with field annotated with + * Class without no-args constructor, but with field annotated with * {@link SerializedName}. */ -public class ClassWithoutDefaultConstructor { +public class ClassWithHasArgsConstructor { @SerializedName("myField") public int i; // Specify explicit constructor with args to remove implicit no-args default constructor - public ClassWithoutDefaultConstructor(int i) { + public ClassWithHasArgsConstructor(int i) { this.i = i; } } diff --git a/shrinker-test/src/main/java/com/example/ClassWithDefaultConstructor.java b/shrinker-test/src/main/java/com/example/ClassWithNoArgsConstructor.java similarity index 52% rename from shrinker-test/src/main/java/com/example/ClassWithDefaultConstructor.java rename to shrinker-test/src/main/java/com/example/ClassWithNoArgsConstructor.java index 6cff1190..f211daf9 100644 --- a/shrinker-test/src/main/java/com/example/ClassWithDefaultConstructor.java +++ b/shrinker-test/src/main/java/com/example/ClassWithNoArgsConstructor.java @@ -3,14 +3,14 @@ package com.example; import com.google.gson.annotations.SerializedName; /** - * Class with no-args default constructor and with field annotated with + * Class with no-args constructor and with field annotated with * {@link SerializedName}. */ -public class ClassWithDefaultConstructor { +public class ClassWithNoArgsConstructor { @SerializedName("myField") public int i; - public ClassWithDefaultConstructor() { + public ClassWithNoArgsConstructor() { i = -3; } } diff --git a/shrinker-test/src/main/java/com/example/ClassWithUnreferencedHasArgsConstructor.java b/shrinker-test/src/main/java/com/example/ClassWithUnreferencedHasArgsConstructor.java new file mode 100644 index 00000000..b0178bf6 --- /dev/null +++ b/shrinker-test/src/main/java/com/example/ClassWithUnreferencedHasArgsConstructor.java @@ -0,0 +1,19 @@ +package com.example; + +import com.google.gson.annotations.SerializedName; + +/** + * Class without no-args constructor, but with field annotated with + * {@link SerializedName}. The constructor should not actually be used in the + * code, but this shouldn't lead to R8 concluding that values of the type are + * not constructible and therefore must be null. + */ +public class ClassWithUnreferencedHasArgsConstructor { + @SerializedName("myField") + public int i; + + // Specify explicit constructor with args to remove implicit no-args default constructor + public ClassWithUnreferencedHasArgsConstructor(int i) { + this.i = i; + } +} diff --git a/shrinker-test/src/main/java/com/example/ClassWithUnreferencedNoArgsConstructor.java b/shrinker-test/src/main/java/com/example/ClassWithUnreferencedNoArgsConstructor.java new file mode 100644 index 00000000..2d430321 --- /dev/null +++ b/shrinker-test/src/main/java/com/example/ClassWithUnreferencedNoArgsConstructor.java @@ -0,0 +1,18 @@ +package com.example; + +import com.google.gson.annotations.SerializedName; + +/** + * Class with no-args constructor and with field annotated with + * {@link SerializedName}. The constructor should not actually be used in the + * code, but this shouldn't lead to R8 concluding that values of the type are + * not constructible and therefore must be null. + */ +public class ClassWithUnreferencedNoArgsConstructor { + @SerializedName("myField") + public int i; + + public ClassWithUnreferencedNoArgsConstructor() { + i = -3; + } +} diff --git a/shrinker-test/src/main/java/com/example/Main.java b/shrinker-test/src/main/java/com/example/Main.java index 488bc03b..d2d88021 100644 --- a/shrinker-test/src/main/java/com/example/Main.java +++ b/shrinker-test/src/main/java/com/example/Main.java @@ -32,7 +32,11 @@ public class Main { testNamedFields(outputConsumer); testSerializedName(outputConsumer); - testNoDefaultConstructor(outputConsumer); + testConstructorNoArgs(outputConsumer); + testConstructorHasArgs(outputConsumer); + testUnreferencedConstructorNoArgs(outputConsumer); + testUnreferencedConstructorHasArgs(outputConsumer); + testNoJdkUnsafe(outputConsumer); testEnum(outputConsumer); @@ -90,12 +94,57 @@ public class Main { }); } - private static void testNoDefaultConstructor(BiConsumer outputConsumer) { + private static void testConstructorNoArgs(BiConsumer outputConsumer) { Gson gson = new GsonBuilder().setPrettyPrinting().create(); - TestExecutor.run(outputConsumer, "Write: No default constructor", () -> toJson(gson, new ClassWithoutDefaultConstructor(2))); + TestExecutor.run(outputConsumer, "Write: No args constructor", () -> toJson( + gson, new ClassWithNoArgsConstructor())); + TestExecutor.run(outputConsumer, "Read: No args constructor; initial constructor value", () -> { + ClassWithNoArgsConstructor deserialized = fromJson(gson, "{}", ClassWithNoArgsConstructor.class); + return Integer.toString(deserialized.i); + }); + TestExecutor.run(outputConsumer, "Read: No args constructor; custom value", () -> { + ClassWithNoArgsConstructor deserialized = fromJson(gson, "{\"myField\": 3}", ClassWithNoArgsConstructor.class); + return Integer.toString(deserialized.i); + }); + } + + private static void testConstructorHasArgs(BiConsumer outputConsumer) { + Gson gson = new GsonBuilder().setPrettyPrinting().create(); + TestExecutor.run(outputConsumer, "Write: Constructor with args", () -> toJson( + gson, new ClassWithHasArgsConstructor(2))); // This most likely relies on JDK Unsafe (unless the shrinker rewrites the constructor in some way) - TestExecutor.run(outputConsumer, "Read: No default constructor", () -> { - ClassWithoutDefaultConstructor deserialized = fromJson(gson, "{\"myField\": 3}", ClassWithoutDefaultConstructor.class); + TestExecutor.run(outputConsumer, "Read: Constructor with args", () -> { + ClassWithHasArgsConstructor deserialized = fromJson( + gson, "{\"myField\": 3}", ClassWithHasArgsConstructor.class); + return Integer.toString(deserialized.i); + }); + } + + private static void testUnreferencedConstructorNoArgs(BiConsumer outputConsumer) { + Gson gson = new GsonBuilder().setPrettyPrinting().create(); + // No write because we're not referencing this class's constructor. + + // This runs the no-args constructor. + TestExecutor.run(outputConsumer, "Read: Unreferenced no args constructor; initial constructor value", () -> { + ClassWithUnreferencedNoArgsConstructor deserialized = fromJson( + gson, "{}", ClassWithUnreferencedNoArgsConstructor.class); + return Integer.toString(deserialized.i); + }); + TestExecutor.run(outputConsumer, "Read: Unreferenced no args constructor; custom value", () -> { + ClassWithUnreferencedNoArgsConstructor deserialized = fromJson( + gson, "{\"myField\": 3}", ClassWithUnreferencedNoArgsConstructor.class); + return Integer.toString(deserialized.i); + }); + } + + private static void testUnreferencedConstructorHasArgs(BiConsumer outputConsumer) { + Gson gson = new GsonBuilder().setPrettyPrinting().create(); + // No write because we're not referencing this class's constructor. + + // This most likely relies on JDK Unsafe (unless the shrinker rewrites the constructor in some way) + TestExecutor.run(outputConsumer, "Read: Unreferenced constructor with args", () -> { + ClassWithUnreferencedHasArgsConstructor deserialized = fromJson( + gson, "{\"myField\": 3}", ClassWithUnreferencedHasArgsConstructor.class); return Integer.toString(deserialized.i); }); } @@ -103,11 +152,13 @@ public class Main { private static void testNoJdkUnsafe(BiConsumer outputConsumer) { Gson gson = new GsonBuilder().disableJdkUnsafe().create(); TestExecutor.run(outputConsumer, "Read: No JDK Unsafe; initial constructor value", () -> { - ClassWithDefaultConstructor deserialized = fromJson(gson, "{}", ClassWithDefaultConstructor.class); + ClassWithNoArgsConstructor deserialized = fromJson( + gson, "{}", ClassWithNoArgsConstructor.class); return Integer.toString(deserialized.i); }); TestExecutor.run(outputConsumer, "Read: No JDK Unsafe; custom value", () -> { - ClassWithDefaultConstructor deserialized = fromJson(gson, "{\"myField\": 3}", ClassWithDefaultConstructor.class); + ClassWithNoArgsConstructor deserialized = fromJson( + gson, "{\"myField\": 3}", ClassWithNoArgsConstructor.class); return Integer.toString(deserialized.i); }); } diff --git a/shrinker-test/src/main/java/com/example/NoSerializedNameMain.java b/shrinker-test/src/main/java/com/example/NoSerializedNameMain.java index cd70af34..a43fc0bd 100644 --- a/shrinker-test/src/main/java/com/example/NoSerializedNameMain.java +++ b/shrinker-test/src/main/java/com/example/NoSerializedNameMain.java @@ -10,7 +10,8 @@ import com.google.gson.GsonBuilder; * therefore not matched by the default {@code gson.pro} rules. */ public class NoSerializedNameMain { - static class TestClass { + static class TestClassNoArgsConstructor { + // Has a no-args default constructor. public String s; } @@ -19,37 +20,40 @@ public class NoSerializedNameMain { public String s; } - static class TestClassWithoutDefaultConstructor { + static class TestClassHasArgsConstructor { public String s; // Specify explicit constructor with args to remove implicit no-args default constructor - public TestClassWithoutDefaultConstructor(String s) { + public TestClassHasArgsConstructor(String s) { this.s = s; } } /** - * Main entrypoint, called by {@code ShrinkingIT.testNoSerializedName_DefaultConstructor()}. + * Main entrypoint, called by {@code ShrinkingIT.testNoSerializedName_NoArgsConstructor()}. */ - public static String runTest() { - TestClass deserialized = new Gson().fromJson("{\"s\":\"value\"}", same(TestClass.class)); + public static String runTestNoArgsConstructor() { + TestClassNoArgsConstructor deserialized = new Gson().fromJson( + "{\"s\":\"value\"}", same(TestClassNoArgsConstructor.class)); return deserialized.s; } /** - * Main entrypoint, called by {@code ShrinkingIT.testNoSerializedName_DefaultConstructorNoJdkUnsafe()}. + * Main entrypoint, called by {@code ShrinkingIT.testNoSerializedName_NoArgsConstructorNoJdkUnsafe()}. */ public static String runTestNoJdkUnsafe() { Gson gson = new GsonBuilder().disableJdkUnsafe().create(); - TestClassNotAbstract deserialized = gson.fromJson("{\"s\": \"value\"}", same(TestClassNotAbstract.class)); + TestClassNotAbstract deserialized = gson.fromJson( + "{\"s\": \"value\"}", same(TestClassNotAbstract.class)); return deserialized.s; } /** - * Main entrypoint, called by {@code ShrinkingIT.testNoSerializedName_NoDefaultConstructor()}. + * Main entrypoint, called by {@code ShrinkingIT.testNoSerializedName_HasArgsConstructor()}. */ - public static String runTestNoDefaultConstructor() { - TestClassWithoutDefaultConstructor deserialized = new Gson().fromJson("{\"s\":\"value\"}", same(TestClassWithoutDefaultConstructor.class)); + public static String runTestHasArgsConstructor() { + TestClassHasArgsConstructor deserialized = new Gson().fromJson( + "{\"s\":\"value\"}", same(TestClassHasArgsConstructor.class)); return deserialized.s; } } diff --git a/shrinker-test/src/test/java/com/google/gson/it/ShrinkingIT.java b/shrinker-test/src/test/java/com/google/gson/it/ShrinkingIT.java index be5a6213..a017c2c3 100644 --- a/shrinker-test/src/test/java/com/google/gson/it/ShrinkingIT.java +++ b/shrinker-test/src/test/java/com/google/gson/it/ShrinkingIT.java @@ -129,12 +129,32 @@ public class ShrinkingIT { "Read: SerializedName", "3", "===", - "Write: No default constructor", + "Write: No args constructor", + "{", + " \"myField\": -3", + "}", + "===", + "Read: No args constructor; initial constructor value", + "-3", + "===", + "Read: No args constructor; custom value", + "3", + "===", + "Write: Constructor with args", "{", " \"myField\": 2", "}", "===", - "Read: No default constructor", + "Read: Constructor with args", + "3", + "===", + "Read: Unreferenced no args constructor; initial constructor value", + "-3", + "===", + "Read: Unreferenced no args constructor; custom value", + "3", + "===", + "Read: Unreferenced constructor with args", "3", "===", "Read: No JDK Unsafe; initial constructor value", @@ -191,9 +211,9 @@ public class ShrinkingIT { } @Test - public void testNoSerializedName_DefaultConstructor() throws Exception { + public void testNoSerializedName_NoArgsConstructor() throws Exception { runTest("com.example.NoSerializedNameMain", c -> { - Method m = c.getMethod("runTest"); + Method m = c.getMethod("runTestNoArgsConstructor"); if (jarToTest.equals(PROGUARD_RESULT_PATH)) { Object result = m.invoke(null); @@ -203,7 +223,7 @@ public class ShrinkingIT { Exception e = assertThrows(InvocationTargetException.class, () -> m.invoke(null)); assertThat(e).hasCauseThat().hasMessageThat().isEqualTo( "Abstract classes can't be instantiated! Adjust the R8 configuration or register an InstanceCreator" - + " or a TypeAdapter for this type. Class name: com.example.NoSerializedNameMain$TestClass" + + " or a TypeAdapter for this type. Class name: com.example.NoSerializedNameMain$TestClassNoArgsConstructor" + "\nSee https://github.com/google/gson/blob/main/Troubleshooting.md#r8-abstract-class" ); } @@ -211,7 +231,7 @@ public class ShrinkingIT { } @Test - public void testNoSerializedName_DefaultConstructorNoJdkUnsafe() throws Exception { + public void testNoSerializedName_NoArgsConstructorNoJdkUnsafe() throws Exception { runTest("com.example.NoSerializedNameMain", c -> { Method m = c.getMethod("runTestNoJdkUnsafe"); @@ -232,9 +252,9 @@ public class ShrinkingIT { } @Test - public void testNoSerializedName_NoDefaultConstructor() throws Exception { + public void testNoSerializedName_HasArgsConstructor() throws Exception { runTest("com.example.NoSerializedNameMain", c -> { - Method m = c.getMethod("runTestNoDefaultConstructor"); + Method m = c.getMethod("runTestHasArgsConstructor"); if (jarToTest.equals(PROGUARD_RESULT_PATH)) { Object result = m.invoke(null); @@ -244,7 +264,7 @@ public class ShrinkingIT { Exception e = assertThrows(InvocationTargetException.class, () -> m.invoke(null)); assertThat(e).hasCauseThat().hasMessageThat().isEqualTo( "Abstract classes can't be instantiated! Adjust the R8 configuration or register an InstanceCreator" - + " or a TypeAdapter for this type. Class name: com.example.NoSerializedNameMain$TestClassWithoutDefaultConstructor" + + " or a TypeAdapter for this type. Class name: com.example.NoSerializedNameMain$TestClassHasArgsConstructor" + "\nSee https://github.com/google/gson/blob/main/Troubleshooting.md#r8-abstract-class" ); }