Turn @ParametricNullness into a no-op for Kotlin and IntelliJ, and reduce its retention to CLASS.

We'll continue annotating our APIs with it for now, since it can be helpful for NullAway and perhaps other tools. (But please [let us know](https://github.com/google/guava/issues/new?template=Blank+issue) if you are depending on it from a tool other than NullAway.)

This is the next step toward [using JSpecify in Guava](jspecify/jspecify#239 (comment)).

Also, I've updated the Javadoc to belatedly note that `ParametricNulless` isn't used by `NullPointerTester` anymore (as of cl/530341970).

RELNOTES=Changed `@ParametricNullness` into a no-op for Kotlin and IntelliJ. Before now, it was forcing many usages of type variables to have [platform types](https://kotlinlang.org/docs/java-interop.html#null-safety-and-platform-types), which meant that Kotlin couldn't check those usages for nullness errors. With this change, Kotlin can detect more errors.
PiperOrigin-RevId: 708610470

Author: cpovirk

android/guava/src/com/google/common/base/ParametricNullness.java

@@ -19,7 +19,7 @@
 import static java.lang.annotation.ElementType.FIELD;
 import static java.lang.annotation.ElementType.METHOD;
 import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static java.lang.annotation.RetentionPolicy.CLASS;
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.annotation.Retention;
@@ -54,32 +54,19 @@
  * <p>Consumers of this annotation include:
  *
  * <ul>
- *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
- *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
- *       to reduce the immediate effects of {@code NullMarked} as we transition to JSpecify
- *       annotations.
- *   <li>NullAway, which will <a
- *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
- *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
- *       you can set {@code
- *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
- *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
- *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
- *       list.
- *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>
- *   <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations
- *       {@code NullPointerTester} would need are not available) and in case of <a
- *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
+ *   <li>NullAway, which <a
+ *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
+ *       identically to {@code Nullable}</a> as of version 0.9.9.
+ *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
+ *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}
+ *       annotations that {@code ParametricNullness} was counteracting.
  * </ul>
  *
- * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
- * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
+ * <p>This annotation is a temporary hack. We will remove it after <a
  * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
  * it</a>.
  */
 @GwtCompatible
-@Retention(RUNTIME)
+@Retention(CLASS)
 @Target({FIELD, METHOD, PARAMETER})
-@javax.annotation.meta.TypeQualifierNickname
-@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)
 @interface ParametricNullness {}

android/guava/src/com/google/common/cache/ParametricNullness.java

@@ -19,7 +19,7 @@
 import static java.lang.annotation.ElementType.FIELD;
 import static java.lang.annotation.ElementType.METHOD;
 import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static java.lang.annotation.RetentionPolicy.CLASS;
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.annotation.Retention;
@@ -54,32 +54,19 @@
  * <p>Consumers of this annotation include:
  *
  * <ul>
- *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
- *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
- *       to reduce the immediate effects of {@code NullMarked} as we transition to JSpecify
- *       annotations.
- *   <li>NullAway, which will <a
- *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
- *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
- *       you can set {@code
- *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
- *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
- *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
- *       list.
- *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>
- *   <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations
- *       {@code NullPointerTester} would need are not available) and in case of <a
- *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
+ *   <li>NullAway, which <a
+ *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
+ *       identically to {@code Nullable}</a> as of version 0.9.9.
+ *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
+ *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}
+ *       annotations that {@code ParametricNullness} was counteracting.
  * </ul>
  *
- * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
- * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
+ * <p>This annotation is a temporary hack. We will remove it after <a
  * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
  * it</a>.
  */
 @GwtCompatible
-@Retention(RUNTIME)
+@Retention(CLASS)
 @Target({FIELD, METHOD, PARAMETER})
-@javax.annotation.meta.TypeQualifierNickname
-@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)
 @interface ParametricNullness {}

android/guava/src/com/google/common/collect/ParametricNullness.java

@@ -19,7 +19,7 @@
 import static java.lang.annotation.ElementType.FIELD;
 import static java.lang.annotation.ElementType.METHOD;
 import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static java.lang.annotation.RetentionPolicy.CLASS;
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.annotation.Retention;
@@ -54,32 +54,19 @@
  * <p>Consumers of this annotation include:
  *
  * <ul>
- *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
- *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
- *       to reduce the immediate effects of {@code NullMarked} as we transition to JSpecify
- *       annotations.
- *   <li>NullAway, which will <a
- *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
- *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
- *       you can set {@code
- *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
- *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
- *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
- *       list.
- *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>
- *   <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations
- *       {@code NullPointerTester} would need are not available) and in case of <a
- *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
+ *   <li>NullAway, which <a
+ *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
+ *       identically to {@code Nullable}</a> as of version 0.9.9.
+ *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
+ *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}
+ *       annotations that {@code ParametricNullness} was counteracting.
  * </ul>
  *
- * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
- * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
+ * <p>This annotation is a temporary hack. We will remove it after <a
  * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
  * it</a>.
  */
 @GwtCompatible
-@Retention(RUNTIME)
+@Retention(CLASS)
 @Target({FIELD, METHOD, PARAMETER})
-@javax.annotation.meta.TypeQualifierNickname
-@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)
 @interface ParametricNullness {}

android/guava/src/com/google/common/escape/ParametricNullness.java

@@ -19,7 +19,7 @@
 import static java.lang.annotation.ElementType.FIELD;
 import static java.lang.annotation.ElementType.METHOD;
 import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static java.lang.annotation.RetentionPolicy.CLASS;
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.annotation.Retention;
@@ -54,32 +54,19 @@
  * <p>Consumers of this annotation include:
  *
  * <ul>
- *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
- *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
- *       to reduce the immediate effects of {@code NullMarked} as we transition to JSpecify
- *       annotations.
- *   <li>NullAway, which will <a
- *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
- *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
- *       you can set {@code
- *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
- *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
- *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
- *       list.
- *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>
- *   <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations
- *       {@code NullPointerTester} would need are not available) and in case of <a
- *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
+ *   <li>NullAway, which <a
+ *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
+ *       identically to {@code Nullable}</a> as of version 0.9.9.
+ *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
+ *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}
+ *       annotations that {@code ParametricNullness} was counteracting.
  * </ul>
  *
- * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
- * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
+ * <p>This annotation is a temporary hack. We will remove it after <a
  * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
  * it</a>.
  */
 @GwtCompatible
-@Retention(RUNTIME)
+@Retention(CLASS)
 @Target({FIELD, METHOD, PARAMETER})
-@javax.annotation.meta.TypeQualifierNickname
-@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)
 @interface ParametricNullness {}

android/guava/src/com/google/common/eventbus/ParametricNullness.java

@@ -19,7 +19,7 @@
 import static java.lang.annotation.ElementType.FIELD;
 import static java.lang.annotation.ElementType.METHOD;
 import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static java.lang.annotation.RetentionPolicy.CLASS;
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.annotation.Retention;
@@ -54,32 +54,19 @@
  * <p>Consumers of this annotation include:
  *
  * <ul>
- *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
- *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
- *       to reduce the immediate effects of {@code NullMarked} as we transition to JSpecify
- *       annotations.
- *   <li>NullAway, which will <a
- *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
- *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
- *       you can set {@code
- *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
- *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
- *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
- *       list.
- *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>
- *   <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations
- *       {@code NullPointerTester} would need are not available) and in case of <a
- *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
+ *   <li>NullAway, which <a
+ *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
+ *       identically to {@code Nullable}</a> as of version 0.9.9.
+ *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
+ *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}
+ *       annotations that {@code ParametricNullness} was counteracting.
  * </ul>
  *
- * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
- * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
+ * <p>This annotation is a temporary hack. We will remove it after <a
  * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
  * it</a>.
  */
 @GwtCompatible
-@Retention(RUNTIME)
+@Retention(CLASS)
 @Target({FIELD, METHOD, PARAMETER})
-@javax.annotation.meta.TypeQualifierNickname
-@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)
 @interface ParametricNullness {}

android/guava/src/com/google/common/graph/ParametricNullness.java

@@ -19,7 +19,7 @@
 import static java.lang.annotation.ElementType.FIELD;
 import static java.lang.annotation.ElementType.METHOD;
 import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static java.lang.annotation.RetentionPolicy.CLASS;
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.annotation.Retention;
@@ -54,32 +54,19 @@
  * <p>Consumers of this annotation include:
  *
  * <ul>
- *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
- *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
- *       to reduce the immediate effects of {@code NullMarked} as we transition to JSpecify
- *       annotations.
- *   <li>NullAway, which will <a
- *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
- *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
- *       you can set {@code
- *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
- *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
- *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
- *       list.
- *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>
- *   <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations
- *       {@code NullPointerTester} would need are not available) and in case of <a
- *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
+ *   <li>NullAway, which <a
+ *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
+ *       identically to {@code Nullable}</a> as of version 0.9.9.
+ *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
+ *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}
+ *       annotations that {@code ParametricNullness} was counteracting.
  * </ul>
  *
- * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
- * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
+ * <p>This annotation is a temporary hack. We will remove it after <a
  * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
  * it</a>.
  */
 @GwtCompatible
-@Retention(RUNTIME)
+@Retention(CLASS)
 @Target({FIELD, METHOD, PARAMETER})
-@javax.annotation.meta.TypeQualifierNickname
-@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)
 @interface ParametricNullness {}

android/guava/src/com/google/common/hash/ParametricNullness.java

@@ -19,7 +19,7 @@
 import static java.lang.annotation.ElementType.FIELD;
 import static java.lang.annotation.ElementType.METHOD;
 import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
+import static java.lang.annotation.RetentionPolicy.CLASS;
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.annotation.Retention;
@@ -54,32 +54,19 @@
  * <p>Consumers of this annotation include:
  *
  * <ul>
- *   <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type
- *       argument is non-nullable and (b) nullable when the type argument is nullable. We use this
- *       to reduce the immediate effects of {@code NullMarked} as we transition to JSpecify
- *       annotations.
- *   <li>NullAway, which will <a
- *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treat it
- *       identically to {@code Nullable} as of version 0.9.9</a>. To treat it that way before then,
- *       you can set {@code
- *       -XepOpt:NullAway:CustomNullableAnnotations=com.google.common.base.ParametricNullness,...,com.google.common.util.concurrent.ParametricNullness},
- *       where the {@code ...} contains the names of all the other {@code ParametricNullness}
- *       annotations in Guava. Or you might prefer to omit Guava from your {@code AnnotatedPackages}
- *       list.
- *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>
- *   <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations
- *       {@code NullPointerTester} would need are not available) and in case of <a
- *       href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a>
+ *   <li>NullAway, which <a
+ *       href="https://github.com/google/guava/issues/6126#issuecomment-1204399671">treats it
+ *       identically to {@code Nullable}</a> as of version 0.9.9.
+ *   <li><a href="https://developers.google.com/j2objc">J2ObjC</a>, maybe: It might no longer be
+ *       necessary there, since we have stopped using the {@code @ParametersAreNonnullByDefault}
+ *       annotations that {@code ParametricNullness} was counteracting.
  * </ul>
  *
- * <p>This annotation is a temporary hack. We will remove it after we're able to adopt the <a
- * href="https://jspecify.dev/">JSpecify</a> nullness annotations and <a
+ * <p>This annotation is a temporary hack. We will remove it after <a
  * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
  * it</a>.
  */
 @GwtCompatible
-@Retention(RUNTIME)
+@Retention(CLASS)
 @Target({FIELD, METHOD, PARAMETER})
-@javax.annotation.meta.TypeQualifierNickname
-@javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN)
 @interface ParametricNullness {}