Build Truth with -source 8 -target 8, updating annotations appropri…

…ately.

This is a small step in the general direction of #746

While there, improve the documentation of deprecated `LiteProtoSubject.isEqualTo(MessageLite.Builder)` and `isNotEqualTo(MessageLite.Builder)`, and add a TODO about possible future steps.

RELNOTES=Truth is now built with `-source 8 -target 8`. This means that it no longer runs under Java 7 VMs. It continues to run under Android, even old versions, for all apps that have [enabled support for Java 8 language features](https://developer.android.com/studio/write/java8-support#supported_features).
PiperOrigin-RevId: 388266403

core/src/main/java/com/google/common/truth/ActualValueInference.java

@@ -31,6 +31,7 @@
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.Map.Entry;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.objectweb.asm.ClassReader;
 import org.objectweb.asm.ClassVisitor;
 import org.objectweb.asm.Handle;
@@ -1507,14 +1508,5 @@ private static void closeQuietly(InputStream stream) {
     }
   }
 
-  /*
-   * TODO(cpovirk): Switch to using Checker Framework @Nullable. The problem I see if I try to
-   * switch now is that the AutoValue-generated code is `@Nullable ActualValueInference.StackEntry`
-   * rather than `ActualValueInference.@Nullable StackEntry`. AutoValue normally gets this right
-   * (b/29530042), so I think the failure here is because we use `-source 7`. That might still be
-   * fine, except that j2objc compilation appears to then use `-source 8`.
-   */
-  @interface Nullable {}
-
   private ActualValueInference() {}
 }

core/src/main/java/com/google/common/truth/FailureMetadata.java

@@ -161,7 +161,7 @@ enum OldAndNewValuesAreSimilar {
    * to set a message is {@code check(...).withMessage(...).that(...)} (for calls from within a
    * {@code Subject}) or {@link Truth#assertWithMessage} (for most other calls).
    */
-  FailureMetadata withMessage(String format, /*@Nullable*/ Object[] args) {
+  FailureMetadata withMessage(String format, @Nullable Object[] args) {
     ImmutableList<LazyMessage> messages = append(this.messages, new LazyMessage(format, args));
     return derive(messages, steps);
   }

core/src/main/java/com/google/common/truth/IterableSubject.java

@@ -204,7 +204,7 @@ public final void containsNoDuplicates() {
 
   /** Checks that the subject contains at least one of the provided objects or fails. */
   public final void containsAnyOf(
-      @Nullable Object first, @Nullable Object second, @Nullable Object /*@Nullable*/... rest) {
+      @Nullable Object first, @Nullable Object second, @Nullable Object @Nullable ... rest) {
     containsAnyIn(accumulate(first, second, rest));
   }
 
@@ -255,7 +255,7 @@ public final void containsAnyIn(Object[] expected) {
   public final Ordered containsAtLeast(
       @Nullable Object firstExpected,
       @Nullable Object secondExpected,
-      @Nullable Object /*@Nullable*/... restOfExpected) {
+      @Nullable Object @Nullable ... restOfExpected) {
     return containsAtLeastElementsIn(accumulate(firstExpected, secondExpected, restOfExpected));
   }
 
@@ -379,7 +379,7 @@ private static void moveElements(List<?> input, Collection<Object> output, int m
    * elements, not an element itself. This helps human readers and avoids a compiler warning.
    */
   @CanIgnoreReturnValue
-  public final Ordered containsExactly(@Nullable Object /*@Nullable*/... varargs) {
+  public final Ordered containsExactly(@Nullable Object @Nullable ... varargs) {
     List<Object> expected = (varargs == null) ? newArrayList((Object) null) : asList(varargs);
     return containsExactlyElementsIn(
         expected, varargs != null && varargs.length == 1 && varargs[0] instanceof Iterable);
@@ -694,7 +694,7 @@ enum ElementFactGrouping {
   public final void containsNoneOf(
       @Nullable Object firstExcluded,
       @Nullable Object secondExcluded,
-      @Nullable Object /*@Nullable*/... restOfExcluded) {
+      @Nullable Object @Nullable ... restOfExcluded) {
     containsNoneIn(accumulate(firstExcluded, secondExcluded, restOfExcluded));
   }
 
@@ -845,7 +845,7 @@ private void pairwiseCheck(String expectedFact, PairwiseChecker checker) {
   @Override
   @Deprecated
   public void isNoneOf(
-      @Nullable Object first, @Nullable Object second, @Nullable Object /*@Nullable*/... rest) {
+      @Nullable Object first, @Nullable Object second, @Nullable Object @Nullable ... rest) {
     super.isNoneOf(first, second, rest);
   }
 
@@ -1056,6 +1056,11 @@ public UsingCorrespondence<A, E> displayingDiffsPairedBy(
      * Checks that the subject contains at least one element that corresponds to the given expected
      * element.
      */
+    /*
+     * TODO(cpovirk): Do we want @Nullable on usages of E? Probably not, since it could throw errors
+     * during comparisons? Or maybe we should take the risk for user convenience? If we make
+     * changes, also make them in MapSubject, MultimapSubject, and possibly others.
+     */
     public void contains(@Nullable E expected) {
       Correspondence.ExceptionStore exceptions = Correspondence.ExceptionStore.forIterable();
       for (A actual : getCastActual()) {
@@ -1153,7 +1158,7 @@ public void doesNotContain(@Nullable E excluded) {
      */
     @SafeVarargs
     @CanIgnoreReturnValue
-    public final Ordered containsExactly(@Nullable E /*@Nullable*/... expected) {
+    public final Ordered containsExactly(@Nullable E @Nullable ... expected) {
       return containsExactlyElementsIn(
           (expected == null) ? newArrayList((E) null) : asList(expected));
     }
@@ -1504,7 +1509,7 @@ private boolean failIfOneToOneMappingHasMissingOrExtra(
     @SafeVarargs
     @CanIgnoreReturnValue
     public final Ordered containsAtLeast(
-        @Nullable E first, @Nullable E second, @Nullable E /*@Nullable*/... rest) {
+        @Nullable E first, @Nullable E second, @Nullable E @Nullable ... rest) {
       return containsAtLeastElementsIn(accumulate(first, second, rest));
     }
 
@@ -1753,7 +1758,7 @@ private boolean failIfOneToOneMappingHasMissing(
      */
     @SafeVarargs
     public final void containsAnyOf(
-        @Nullable E first, @Nullable E second, @Nullable E /*@Nullable*/... rest) {
+        @Nullable E first, @Nullable E second, @Nullable E @Nullable ... rest) {
       containsAnyIn(accumulate(first, second, rest));
     }
 
@@ -1861,7 +1866,7 @@ private ImmutableList<Fact> describeAnyMatchesByKey(
     public final void containsNoneOf(
         @Nullable E firstExcluded,
         @Nullable E secondExcluded,
-        @Nullable E /*@Nullable*/... restOfExcluded) {
+        @Nullable E @Nullable ... restOfExcluded) {
       containsNoneIn(accumulate(firstExcluded, secondExcluded, restOfExcluded));
     }
 

core/src/main/java/com/google/common/truth/LazyMessage.java

@@ -20,6 +20,7 @@
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableList;
+import org.checkerframework.checker.nullness.qual.Nullable;
 
 final class LazyMessage {
   private static final String PLACEHOLDER_ERR =
@@ -28,7 +29,7 @@ final class LazyMessage {
   private final String format;
   private final Object[] args;
 
-  LazyMessage(String format, /*@Nullable*/ Object... args) {
+  LazyMessage(String format, @Nullable Object... args) {
     this.format = format;
     this.args = args;
     int placeholders = countPlaceholders(format);

core/src/main/java/com/google/common/truth/MapSubject.java

@@ -188,18 +188,18 @@ public final Ordered containsExactly() {
    */
   @CanIgnoreReturnValue
   public final Ordered containsExactly(
-      @Nullable Object k0, @Nullable Object v0, /*@Nullable*/ Object... rest) {
+      @Nullable Object k0, @Nullable Object v0, @Nullable Object... rest) {
     return containsExactlyEntriesIn(accumulateMap("containsExactly", k0, v0, rest));
   }
 
   @CanIgnoreReturnValue
   public final Ordered containsAtLeast(
-      @Nullable Object k0, @Nullable Object v0, /*@Nullable*/ Object... rest) {
+      @Nullable Object k0, @Nullable Object v0, @Nullable Object... rest) {
     return containsAtLeastEntriesIn(accumulateMap("containsAtLeast", k0, v0, rest));
   }
 
   private static Map<Object, Object> accumulateMap(
-      String functionName, @Nullable Object k0, @Nullable Object v0, /*@Nullable*/ Object... rest) {
+      String functionName, @Nullable Object k0, @Nullable Object v0, @Nullable Object... rest) {
     checkArgument(
         rest.length % 2 == 0,
         "There must be an equal number of key/value pairs "
@@ -682,8 +682,7 @@ public void doesNotContainEntry(@Nullable Object excludedKey, @Nullable E exclud
     // TODO(b/25744307): Can we add an error-prone check that rest.length % 2 == 0?
     // For bonus points, checking that the even-numbered values are of type E would be sweet.
     @CanIgnoreReturnValue
-    public Ordered containsExactly(
-        @Nullable Object k0, @Nullable E v0, /*@Nullable*/ Object... rest) {
+    public Ordered containsExactly(@Nullable Object k0, @Nullable E v0, @Nullable Object... rest) {
       @SuppressWarnings("unchecked") // throwing ClassCastException is the correct behaviour
       Map<Object, E> expectedMap = (Map<Object, E>) accumulateMap("containsExactly", k0, v0, rest);
       return containsExactlyEntriesIn(expectedMap);
@@ -702,8 +701,7 @@ public Ordered containsExactly(
     // TODO(b/25744307): Can we add an error-prone check that rest.length % 2 == 0?
     // For bonus points, checking that the even-numbered values are of type E would be sweet.
     @CanIgnoreReturnValue
-    public Ordered containsAtLeast(
-        @Nullable Object k0, @Nullable E v0, /*@Nullable*/ Object... rest) {
+    public Ordered containsAtLeast(@Nullable Object k0, @Nullable E v0, @Nullable Object... rest) {
       @SuppressWarnings("unchecked") // throwing ClassCastException is the correct behaviour
       Map<Object, E> expectedMap = (Map<Object, E>) accumulateMap("containsAtLeast", k0, v0, rest);
       return containsAtLeastEntriesIn(expectedMap);

core/src/main/java/com/google/common/truth/MultimapSubject.java

@@ -305,7 +305,7 @@ public final Ordered containsExactly() {
    */
   @CanIgnoreReturnValue
   public final Ordered containsExactly(
-      @Nullable Object k0, @Nullable Object v0, /*@Nullable*/ Object... rest) {
+      @Nullable Object k0, @Nullable Object v0, @Nullable Object... rest) {
     return containsExactlyEntriesIn(accumulateMultimap(k0, v0, rest));
   }
 
@@ -317,12 +317,12 @@ public final Ordered containsExactly(
    */
   @CanIgnoreReturnValue
   public final Ordered containsAtLeast(
-      @Nullable Object k0, @Nullable Object v0, /*@Nullable*/ Object... rest) {
+      @Nullable Object k0, @Nullable Object v0, @Nullable Object... rest) {
     return containsAtLeastEntriesIn(accumulateMultimap(k0, v0, rest));
   }
 
   private static Multimap<Object, Object> accumulateMultimap(
-      @Nullable Object k0, @Nullable Object v0, /*@Nullable*/ Object... rest) {
+      @Nullable Object k0, @Nullable Object v0, @Nullable Object... rest) {
     checkArgument(
         rest.length % 2 == 0,
         "There must be an equal number of key/value pairs "
@@ -770,8 +770,7 @@ private <K, V extends E> Ordered internalContainsAtLeastEntriesIn(
      * key/value pairs at compile time. Please make sure you provide varargs in key/value pairs!
      */
     @CanIgnoreReturnValue
-    public Ordered containsExactly(
-        @Nullable Object k0, @Nullable E v0, /*@Nullable*/ Object... rest) {
+    public Ordered containsExactly(@Nullable Object k0, @Nullable E v0, @Nullable Object... rest) {
       @SuppressWarnings("unchecked")
       Multimap<?, E> expectedMultimap = (Multimap<?, E>) accumulateMultimap(k0, v0, rest);
       return containsExactlyEntriesIn(expectedMultimap);
@@ -790,8 +789,7 @@ public Ordered containsExactly() {
      * key/value pairs at compile time. Please make sure you provide varargs in key/value pairs!
      */
     @CanIgnoreReturnValue
-    public Ordered containsAtLeast(
-        @Nullable Object k0, @Nullable E v0, /*@Nullable*/ Object... rest) {
+    public Ordered containsAtLeast(@Nullable Object k0, @Nullable E v0, @Nullable Object... rest) {
       @SuppressWarnings("unchecked")
       Multimap<?, E> expectedMultimap = (Multimap<?, E>) accumulateMultimap(k0, v0, rest);
       return containsAtLeastEntriesIn(expectedMultimap);

core/src/main/java/com/google/common/truth/ObjectArraySubject.java

@@ -27,7 +27,7 @@ public final class ObjectArraySubject<T> extends AbstractArraySubject {
   private final T[] actual;
 
   ObjectArraySubject(
-      FailureMetadata metadata, @Nullable T /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, @Nullable T @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveBooleanArraySubject.java

@@ -27,7 +27,7 @@ public final class PrimitiveBooleanArraySubject extends AbstractArraySubject {
   private final boolean[] actual;
 
   PrimitiveBooleanArraySubject(
-      FailureMetadata metadata, boolean /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, boolean @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveByteArraySubject.java

@@ -27,7 +27,7 @@ public final class PrimitiveByteArraySubject extends AbstractArraySubject {
   private final byte[] actual;
 
   PrimitiveByteArraySubject(
-      FailureMetadata metadata, byte /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, byte @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveCharArraySubject.java

@@ -27,7 +27,7 @@ public final class PrimitiveCharArraySubject extends AbstractArraySubject {
   private final char[] actual;
 
   PrimitiveCharArraySubject(
-      FailureMetadata metadata, char /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, char @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveDoubleArraySubject.java

@@ -34,7 +34,7 @@ public final class PrimitiveDoubleArraySubject extends AbstractArraySubject {
   private final double[] actual;
 
   PrimitiveDoubleArraySubject(
-      FailureMetadata metadata, double /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, double @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveFloatArraySubject.java

@@ -34,7 +34,7 @@ public final class PrimitiveFloatArraySubject extends AbstractArraySubject {
   private final float[] actual;
 
   PrimitiveFloatArraySubject(
-      FailureMetadata metadata, float /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, float @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveIntArraySubject.java

@@ -27,7 +27,7 @@ public final class PrimitiveIntArraySubject extends AbstractArraySubject {
   private final int[] actual;
 
   PrimitiveIntArraySubject(
-      FailureMetadata metadata, int /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, int @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveLongArraySubject.java

@@ -27,7 +27,7 @@ public final class PrimitiveLongArraySubject extends AbstractArraySubject {
   private final long[] actual;
 
   PrimitiveLongArraySubject(
-      FailureMetadata metadata, long /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, long @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/PrimitiveShortArraySubject.java

@@ -27,7 +27,7 @@ public final class PrimitiveShortArraySubject extends AbstractArraySubject {
   private final short[] actual;
 
   PrimitiveShortArraySubject(
-      FailureMetadata metadata, short /*@Nullable*/[] o, @Nullable String typeDescription) {
+      FailureMetadata metadata, short @Nullable [] o, @Nullable String typeDescription) {
     super(metadata, o, typeDescription);
     this.actual = o;
   }

core/src/main/java/com/google/common/truth/StandardSubjectBuilder.java

@@ -112,39 +112,39 @@ public final IterableSubject that(@Nullable Iterable<?> actual) {
     return new IterableSubject(metadata(), actual);
   }
 
-  public final <T> ObjectArraySubject<T> that(@Nullable T /*@Nullable*/[] actual) {
+  public final <T> ObjectArraySubject<T> that(@Nullable T @Nullable [] actual) {
     return new ObjectArraySubject<>(metadata(), actual, "array");
   }
 
-  public final PrimitiveBooleanArraySubject that(boolean /*@Nullable*/[] actual) {
+  public final PrimitiveBooleanArraySubject that(boolean @Nullable [] actual) {
     return new PrimitiveBooleanArraySubject(metadata(), actual, "array");
   }
 
-  public final PrimitiveShortArraySubject that(short /*@Nullable*/[] actual) {
+  public final PrimitiveShortArraySubject that(short @Nullable [] actual) {
     return new PrimitiveShortArraySubject(metadata(), actual, "array");
   }
 
-  public final PrimitiveIntArraySubject that(int /*@Nullable*/[] actual) {
+  public final PrimitiveIntArraySubject that(int @Nullable [] actual) {
     return new PrimitiveIntArraySubject(metadata(), actual, "array");
   }
 
-  public final PrimitiveLongArraySubject that(long /*@Nullable*/[] actual) {
+  public final PrimitiveLongArraySubject that(long @Nullable [] actual) {
     return new PrimitiveLongArraySubject(metadata(), actual, "array");
   }
 
-  public final PrimitiveCharArraySubject that(char /*@Nullable*/[] actual) {
+  public final PrimitiveCharArraySubject that(char @Nullable [] actual) {
     return new PrimitiveCharArraySubject(metadata(), actual, "array");
   }
 
-  public final PrimitiveByteArraySubject that(byte /*@Nullable*/[] actual) {
+  public final PrimitiveByteArraySubject that(byte @Nullable [] actual) {
     return new PrimitiveByteArraySubject(metadata(), actual, "array");
   }
 
-  public final PrimitiveFloatArraySubject that(float /*@Nullable*/[] actual) {
+  public final PrimitiveFloatArraySubject that(float @Nullable [] actual) {
     return new PrimitiveFloatArraySubject(metadata(), actual, "array");
   }
 
-  public final PrimitiveDoubleArraySubject that(double /*@Nullable*/[] actual) {
+  public final PrimitiveDoubleArraySubject that(double @Nullable [] actual) {
     return new PrimitiveDoubleArraySubject(metadata(), actual, "array");
   }
 
@@ -189,7 +189,7 @@ public final StandardSubjectBuilder withMessage(@Nullable String messageToPrepen
    * @throws IllegalArgumentException if the number of placeholders in the format string does not
    *     equal the number of given arguments
    */
-  public final StandardSubjectBuilder withMessage(String format, /*@Nullable*/ Object... args) {
+  public final StandardSubjectBuilder withMessage(String format, @Nullable Object... args) {
     return new StandardSubjectBuilder(metadata().withMessage(format, args));
   }
 

core/src/main/java/com/google/common/truth/Subject.java

@@ -346,7 +346,7 @@ public void isIn(Iterable<?> iterable) {
 
   /** Fails unless the subject is equal to any of the given elements. */
   public void isAnyOf(
-      @Nullable Object first, @Nullable Object second, @Nullable Object /*@Nullable*/... rest) {
+      @Nullable Object first, @Nullable Object second, @Nullable Object @Nullable ... rest) {
     isIn(accumulate(first, second, rest));
   }
 
@@ -359,7 +359,7 @@ public void isNotIn(Iterable<?> iterable) {
 
   /** Fails if the subject is equal to any of the given elements. */
   public void isNoneOf(
-      @Nullable Object first, @Nullable Object second, @Nullable Object /*@Nullable*/... rest) {
+      @Nullable Object first, @Nullable Object second, @Nullable Object @Nullable ... rest) {
     isNotIn(accumulate(first, second, rest));
   }