More reliably use transitional @CheckForNull and `@ParametricNullne…

…ss` annotations.

I would assume we're still not 100% consistent in using them, and we might someday consider an Error Prone check to identify the remaining places that we ought to be using them. But in an ideal world, they'll be able to go away entirely before we need to bother.

(There are a few reasons to use these annotations, but the one that I was poking at today was trying to [run NullAway](#2484 (comment)).)

RELNOTES=n/a
PiperOrigin-RevId: 494880081

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

@@ -39,7 +39,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import org.checkerframework.checker.nullness.qual.Nullable;
+import javax.annotation.CheckForNull;
 
 /**
  * A builder of {@link LoadingCache} and {@link Cache} instances.
@@ -276,10 +276,10 @@ public long read() {
   int concurrencyLevel = UNSET_INT;
   long maximumSize = UNSET_INT;
   long maximumWeight = UNSET_INT;
-  @Nullable Weigher<? super K, ? super V> weigher;
+  @CheckForNull Weigher<? super K, ? super V> weigher;
 
-  @Nullable Strength keyStrength;
-  @Nullable Strength valueStrength;
+  @CheckForNull Strength keyStrength;
+  @CheckForNull Strength valueStrength;
 
   @SuppressWarnings("GoodTime") // should be a java.time.Duration
   long expireAfterWriteNanos = UNSET_INT;
@@ -290,11 +290,11 @@ public long read() {
   @SuppressWarnings("GoodTime") // should be a java.time.Duration
   long refreshNanos = UNSET_INT;
 
-  @Nullable Equivalence<Object> keyEquivalence;
-  @Nullable Equivalence<Object> valueEquivalence;
+  @CheckForNull Equivalence<Object> keyEquivalence;
+  @CheckForNull Equivalence<Object> valueEquivalence;
 
-  @Nullable RemovalListener<? super K, ? super V> removalListener;
-  @Nullable Ticker ticker;
+  @CheckForNull RemovalListener<? super K, ? super V> removalListener;
+  @CheckForNull Ticker ticker;
 
   Supplier<? extends StatsCounter> statsCounterSupplier = NULL_STATS_COUNTER;
 

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

@@ -1175,6 +1175,7 @@ public boolean hasNext() {
     }
 
     @Override
+    @ParametricNullness
     public T next() {
       if (!valueIterator.hasNext()) {
         Entry<K, Collection<V>> mapEntry = keyIterator.next();

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

@@ -32,7 +32,6 @@
 import java.util.Map;
 import java.util.Map.Entry;
 import javax.annotation.CheckForNull;
-import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
  * A {@link ListMultimap} whose contents will never change, with many other important properties
@@ -280,7 +279,7 @@ public static <K, V> ImmutableListMultimap<K, V> copyOf(
   /** Creates an ImmutableListMultimap from an asMap.entrySet. */
   static <K, V> ImmutableListMultimap<K, V> fromMapEntries(
       Collection<? extends Map.Entry<? extends K, ? extends Collection<? extends V>>> mapEntries,
-      @Nullable Comparator<? super V> valueComparator) {
+      @CheckForNull Comparator<? super V> valueComparator) {
     if (mapEntries.isEmpty()) {
       return of();
     }

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

@@ -1993,6 +1993,7 @@ public interface EntryTransformer<
      * @throws NullPointerException if the key or value is null and this transformer does not accept
      *     null arguments
      */
+    @ParametricNullness
     V2 transformEntry(@ParametricNullness K key, @ParametricNullness V1 value);
   }
 

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

@@ -459,7 +459,7 @@ public int count(@CheckForNull Object o) {
     }
 
     @Override
-    public int add(E e, int n) {
+    public int add(@ParametricNullness E e, int n) {
       synchronized (mutex) {
         return delegate().add(e, n);
       }
@@ -473,14 +473,14 @@ public int remove(@CheckForNull Object o, int n) {
     }
 
     @Override
-    public int setCount(E element, int count) {
+    public int setCount(@ParametricNullness E element, int count) {
       synchronized (mutex) {
         return delegate().setCount(element, count);
       }
     }
 
     @Override
-    public boolean setCount(E element, int oldCount, int newCount) {
+    public boolean setCount(@ParametricNullness E element, int oldCount, int newCount) {
       synchronized (mutex) {
         return delegate().setCount(element, oldCount, newCount);
       }
@@ -588,21 +588,21 @@ public boolean containsEntry(@CheckForNull Object key, @CheckForNull Object valu
     }
 
     @Override
-    public Collection<V> get(K key) {
+    public Collection<V> get(@ParametricNullness K key) {
       synchronized (mutex) {
         return typePreservingCollection(delegate().get(key), mutex);
       }
     }
 
     @Override
-    public boolean put(K key, V value) {
+    public boolean put(@ParametricNullness K key, @ParametricNullness V value) {
       synchronized (mutex) {
         return delegate().put(key, value);
       }
     }
 
     @Override
-    public boolean putAll(K key, Iterable<? extends V> values) {
+    public boolean putAll(@ParametricNullness K key, Iterable<? extends V> values) {
       synchronized (mutex) {
         return delegate().putAll(key, values);
       }
@@ -616,7 +616,7 @@ public boolean putAll(Multimap<? extends K, ? extends V> multimap) {
     }
 
     @Override
-    public Collection<V> replaceValues(K key, Iterable<? extends V> values) {
+    public Collection<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
       synchronized (mutex) {
         return delegate().replaceValues(key, values); // copy not synchronized
       }
@@ -1229,7 +1229,7 @@ public Set<V> values() {
 
     @Override
     @CheckForNull
-    public V forcePut(K key, V value) {
+    public V forcePut(@ParametricNullness K key, @ParametricNullness V value) {
       synchronized (mutex) {
         return delegate().forcePut(key, value);
       }
@@ -1989,7 +1989,10 @@ public void clear() {
 
     @Override
     @CheckForNull
-    public V put(R rowKey, C columnKey, V value) {
+    public V put(
+        @ParametricNullness R rowKey,
+        @ParametricNullness C columnKey,
+        @ParametricNullness V value) {
       synchronized (mutex) {
         return delegate().put(rowKey, columnKey, value);
       }
@@ -2011,14 +2014,14 @@ public V remove(@CheckForNull Object rowKey, @CheckForNull Object columnKey) {
     }
 
     @Override
-    public Map<C, V> row(R rowKey) {
+    public Map<C, V> row(@ParametricNullness R rowKey) {
       synchronized (mutex) {
         return map(delegate().row(rowKey), mutex);
       }
     }
 
     @Override
-    public Map<R, V> column(C columnKey) {
+    public Map<R, V> column(@ParametricNullness C columnKey) {
       synchronized (mutex) {
         return map(delegate().column(columnKey), mutex);
       }

android/guava/src/com/google/common/io/ByteSource.java

@@ -316,6 +316,7 @@ public byte[] read() throws IOException {
    */
   @Beta
   @CanIgnoreReturnValue // some processors won't return a useful result
+  @ParametricNullness
   public <T extends @Nullable Object> T read(ByteProcessor<T> processor) throws IOException {
     checkNotNull(processor);
 

android/guava/src/com/google/common/util/concurrent/CollectionFuture.java

@@ -102,9 +102,9 @@ static final class ListFuture<V extends @Nullable Object>
 
   /** The result of a successful {@code Future}. */
   private static final class Present<V extends @Nullable Object> {
-    final V value;
+    @ParametricNullness final V value;
 
-    Present(V value) {
+    Present(@ParametricNullness V value) {
       this.value = value;
     }
   }

android/guava/src/com/google/common/util/concurrent/ImmediateFuture.java

@@ -23,6 +23,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
+import javax.annotation.CheckForNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /** Implementation of {@link Futures#immediateFuture}. */
@@ -98,7 +99,8 @@ static final class ImmediateFailedFuture<V extends @Nullable Object> extends Tru
   }
 
   static final class ImmediateCancelledFuture<V extends @Nullable Object> extends TrustedFuture<V> {
-    static final @Nullable ImmediateCancelledFuture<Object> INSTANCE =
+    @CheckForNull
+    static final ImmediateCancelledFuture<Object> INSTANCE =
         AbstractFuture.GENERATE_CANCELLATION_CAUSES ? null : new ImmediateCancelledFuture<>();
 
     ImmediateCancelledFuture() {

android/guava/src/com/google/common/util/concurrent/SimpleTimeLimiter.java

@@ -111,6 +111,7 @@ private static <T> T newProxy(Class<T> interfaceType, InvocationHandler handler)
     return interfaceType.cast(object);
   }
 
+  @ParametricNullness
   private <T extends @Nullable Object> T callWithTimeout(
       Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit, boolean amInterruptible)
       throws Exception {
@@ -141,6 +142,7 @@ private static <T> T newProxy(Class<T> interfaceType, InvocationHandler handler)
 
   @CanIgnoreReturnValue
   @Override
+  @ParametricNullness
   public <T extends @Nullable Object> T callWithTimeout(
       Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
       throws TimeoutException, InterruptedException, ExecutionException {
@@ -163,6 +165,7 @@ private static <T> T newProxy(Class<T> interfaceType, InvocationHandler handler)
 
   @CanIgnoreReturnValue
   @Override
+  @ParametricNullness
   public <T extends @Nullable Object> T callUninterruptiblyWithTimeout(
       Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
       throws TimeoutException, ExecutionException {

android/guava/src/com/google/common/util/concurrent/TimeLimiter.java

@@ -99,6 +99,7 @@ public interface TimeLimiter {
    * @since 22.0
    */
   @CanIgnoreReturnValue
+  @ParametricNullness
   <T extends @Nullable Object> T callWithTimeout(
       Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
       throws TimeoutException, InterruptedException, ExecutionException;
@@ -123,6 +124,7 @@ public interface TimeLimiter {
    * @since 22.0
    */
   @CanIgnoreReturnValue
+  @ParametricNullness
   <T extends @Nullable Object> T callUninterruptiblyWithTimeout(
       Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit)
       throws TimeoutException, ExecutionException;

guava/src/com/google/common/cache/CacheBuilder.java

@@ -40,7 +40,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Level;
 import java.util.logging.Logger;
-import org.checkerframework.checker.nullness.qual.Nullable;
+import javax.annotation.CheckForNull;
 
 /**
  * A builder of {@link LoadingCache} and {@link Cache} instances.
@@ -277,10 +277,10 @@ public long read() {
   int concurrencyLevel = UNSET_INT;
   long maximumSize = UNSET_INT;
   long maximumWeight = UNSET_INT;
-  @Nullable Weigher<? super K, ? super V> weigher;
+  @CheckForNull Weigher<? super K, ? super V> weigher;
 
-  @Nullable Strength keyStrength;
-  @Nullable Strength valueStrength;
+  @CheckForNull Strength keyStrength;
+  @CheckForNull Strength valueStrength;
 
   @SuppressWarnings("GoodTime") // should be a java.time.Duration
   long expireAfterWriteNanos = UNSET_INT;
@@ -291,11 +291,11 @@ public long read() {
   @SuppressWarnings("GoodTime") // should be a java.time.Duration
   long refreshNanos = UNSET_INT;
 
-  @Nullable Equivalence<Object> keyEquivalence;
-  @Nullable Equivalence<Object> valueEquivalence;
+  @CheckForNull Equivalence<Object> keyEquivalence;
+  @CheckForNull Equivalence<Object> valueEquivalence;
 
-  @Nullable RemovalListener<? super K, ? super V> removalListener;
-  @Nullable Ticker ticker;
+  @CheckForNull RemovalListener<? super K, ? super V> removalListener;
+  @CheckForNull Ticker ticker;
 
   Supplier<? extends StatsCounter> statsCounterSupplier = NULL_STATS_COUNTER;
 

guava/src/com/google/common/collect/AbstractMapBasedMultimap.java

@@ -1188,6 +1188,7 @@ public boolean hasNext() {
     }
 
     @Override
+    @ParametricNullness
     public T next() {
       if (!valueIterator.hasNext()) {
         Entry<K, Collection<V>> mapEntry = keyIterator.next();

guava/src/com/google/common/collect/ImmutableListMultimap.java

@@ -356,7 +356,7 @@ public static <K, V> ImmutableListMultimap<K, V> copyOf(
   /** Creates an ImmutableListMultimap from an asMap.entrySet. */
   static <K, V> ImmutableListMultimap<K, V> fromMapEntries(
       Collection<? extends Map.Entry<? extends K, ? extends Collection<? extends V>>> mapEntries,
-      @Nullable Comparator<? super V> valueComparator) {
+      @CheckForNull Comparator<? super V> valueComparator) {
     if (mapEntries.isEmpty()) {
       return of();
     }

guava/src/com/google/common/collect/ImmutableSet.java

@@ -724,7 +724,7 @@ static int chooseTableSize(int setSize) {
    */
   private static final class RegularSetBuilderImpl<E> extends SetBuilderImpl<E> {
     // null until at least two elements are present
-    private @Nullable Object @Nullable [] hashTable;
+    @CheckForNull private @Nullable Object[] hashTable;
     private int maxRunBeforeFallback;
     private int expandTableThreshold;
     private int hashCode;

guava/src/com/google/common/collect/Maps.java

@@ -2121,6 +2121,7 @@ public interface EntryTransformer<
      * @throws NullPointerException if the key or value is null and this transformer does not accept
      *     null arguments
      */
+    @ParametricNullness
     V2 transformEntry(@ParametricNullness K key, @ParametricNullness V1 value);
   }
 

guava/src/com/google/common/collect/MoreCollectors.java

@@ -25,6 +25,7 @@
 import java.util.NoSuchElementException;
 import java.util.Optional;
 import java.util.stream.Collector;
+import javax.annotation.CheckForNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 /**
@@ -93,7 +94,7 @@ public final class MoreCollectors {
   private static final class ToOptionalState {
     static final int MAX_EXTRAS = 4;
 
-    @Nullable Object element;
+    @CheckForNull Object element;
     List<Object> extras;
 
     ToOptionalState() {