THROWS_METHOD_THROWS_CLAUSE_BASIC_EXCEPTION false positive with super class

[rovarga]

With spotbugs-4.7.0, the following snipped incurs THROWS_METHOD_THROWS_CLAUSE_BASIC_EXCEPTION:

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;

    private static final LoadingCache<Object, SingletonSet<Object>> CACHE = CacheBuilder.newBuilder().weakValues()
            .build(new CacheLoader<Object, SingletonSet<Object>>() {
                @Override
                public SingletonSet<Object> load(final Object key) {
                    return SingletonSet.of(key);
                }
            });

The resulting bytecode for the anonymous CacheLoader subclass looks like this:

{
  org.opendaylight.yangtools.util.SharedSingletonMap$1();
    descriptor: ()V
    flags: (0x0000)
    Code:
      stack=1, locals=1, args_size=1
         0: aload_0
         1: invokespecial #1                  // Method com/google/common/cache/CacheLoader."<init>":()V
         4: return
      LineNumberTable:
        line 72: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       5     0  this   Lorg/opendaylight/yangtools/util/SharedSingletonMap$1;

  public org.opendaylight.yangtools.util.SingletonSet<java.lang.Object> load(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Lorg/opendaylight/yangtools/util/SingletonSet;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=2, args_size=2
         0: aload_1
         1: invokestatic  #7                  // Method org/opendaylight/yangtools/util/SingletonSet.of:(Ljava/lang/Object;)Lorg/opendaylight/yangtools/util/SingletonSet;
         4: areturn
      LineNumberTable:
        line 75: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       5     0  this   Lorg/opendaylight/yangtools/util/SharedSingletonMap$1;
            0       5     1   key   Ljava/lang/Object;
    MethodParameters:
      Name                           Flags
      key                            final
    Signature: #27                          // (Ljava/lang/Object;)Lorg/opendaylight/yangtools/util/SingletonSet<Ljava/lang/Object;>;

  public java.lang.Object load(java.lang.Object) throws java.lang.Exception;
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: aload_0
         1: aload_1
         2: invokevirtual #13                 // Method load:(Ljava/lang/Object;)Lorg/opendaylight/yangtools/util/SingletonSet;
         5: areturn
      LineNumberTable:
        line 72: 0
      LocalVariableTable:
        Start  Length  Slot  Name   Signature
            0       6     0  this   Lorg/opendaylight/yangtools/util/SharedSingletonMap$1;
    Exceptions:
      throws java.lang.Exception
    MethodParameters:
      Name                           Flags
      key                            final synthetic
}

SpotBugs will complain about the second method and (based on line numbers) will point the user to the perfectly-fine looking source code.

[KengoTODA]

@baloghadamsoftware could you check this issue when you have time? Thanks in advance!

[baloghadamsoftware]

@oroszbd Could please take a look on this one?

[famod]

IMO, there should be no such violation in general when the exception declaration is inherited from a super class or interface.
While it's true that you can and probably should reduce the throws declaration to what can actually happen in the concrete impl, it all becomes very awkward when lambda expressions are involved (for which you cannot alter the declaration).

[iloveeclipse]

IMO, there should be no such violation in general when the exception declaration is inherited form a super class or interface.

Exact. We see literally hundreds of warnings reported on implementors of ISafeRunnable which is defined like

	/**
	 * Runs this runnable.  Any exceptions thrown from this method will
	 * be logged by the caller and passed to this runnable's
	 * {@link #handleException} method.
	 *
	 * @exception Exception if a problem occurred while running this method
	 * @see SafeRunner#run(ISafeRunnable)
	 */
	public void run() throws Exception;

See
https://github.com/eclipse-equinox/equinox.bundles/blob/fd2f4fbc8f5be1ff93d197e974ffd3482788e837/bundles/org.eclipse.equinox.common/src/org/eclipse/core/runtime/ISafeRunnable.java#L38

[baloghadamsoftware]

IMO, there should be no such violation in general when the exception declaration is inherited from a super class or interface.

I agree. The case where the exception declaration is inherited from the superclass must be ignored.

[iloveeclipse]

Duplicate of #2040