[YANGTOOLS-1474] Fail to process augmentation with empty grouping

Relates — Mon, 30 Jan 2023 12:27:11 +0000

Parsing of YANG models may fail with the following conditions:

YANG models include augmentation with an empty grouping
Parsing is done with no supported features

For example, parsing of the following two YANG modules with no supported features - the augmentation effectively does nothing but there is a such data model actually used in the device, believe it or not:

foo.yang

module foo {
  namespace "urn:foo";
  prefix "foo";

  container foo {
    leaf foo-leaf {
      type string;
    }
  }
}

bar.yang

module bar {
  namespace "urn:bar";
  prefix "bar";

  import foo {
    prefix foo;
  }

  grouping bar-group {
  }

  augment "/foo:foo" {
    uses bar-group;
  }
}

may trigger the following exception:

Caused by: org.opendaylight.yangtools.yang.parser.spi.meta.SomeModifiersUnresolvedException: Some of EFFECTIVE_MODEL modifiers for statements were not resolved.
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.BuildGlobalContext.propagateException(BuildGlobalContext.java:233)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.BuildGlobalContext.transformEffective(BuildGlobalContext.java:263)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.BuildGlobalContext.buildEffective(BuildGlobalContext.java:208)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.CrossSourceStatementReactor$BuildAction.buildEffective(CrossSourceStatementReactor.java:232)
	at org.opendaylight.yangtools.yang.parser.rfc7950@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.stmt.TestUtils.parseYangSource(TestUtils.java:95)
	at org.opendaylight.yangtools.yang.parser.rfc7950@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.stmt.AbstractYangTest.assertEffectiveModel(AbstractYangTest.java:44)
	... 72 more
Caused by: com.google.common.base.VerifyException: expected a non-null reference
	at com.google.common@31.1-jre/com.google.common.base.Verify.verifyNotNull(Verify.java:503)
	at com.google.common@31.1-jre/com.google.common.base.Verify.verifyNotNull(Verify.java:479)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.AbstractResumedStatement.mutableDeclaredSubstatements(AbstractResumedStatement.java:67)
	at org.opendaylight.yangtools.yang.parser.spi@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext$Mutable.declaredSubstatements(StmtContext.java:234)
	at org.opendaylight.yangtools.yang.parser.spi@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.spi.meta.StmtContextUtils.checkFeatureSupport(StmtContextUtils.java:221)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.ReactorStmtCtx.isSupportedByFeatures(ReactorStmtCtx.java:490)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:178)
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
	at java.base/java.util.Iterator.forEachRemaining(Iterator.java:133)
	at java.base/java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1845)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
	at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:921)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:682)
	at org.opendaylight.yangtools.yang.parser.spi@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.spi.meta.AbstractStatementSupport.declaredSubstatements(AbstractStatementSupport.java:174)
	at org.opendaylight.yangtools.yang.parser.spi@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.spi.meta.AbstractStatementSupport.createEffective(AbstractStatementSupport.java:84)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.AbstractResumedStatement.createEffective(AbstractResumedStatement.java:131)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.AbstractResumedStatement.createEffective(AbstractResumedStatement.java:116)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.StatementContextBase.createEffective(StatementContextBase.java:426)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.ReactorStmtCtx.loadEffective(ReactorStmtCtx.java:375)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.ReactorStmtCtx.buildEffective(ReactorStmtCtx.java:371)
	at org.opendaylight.yangtools.yang.parser.reactor@10.0.3-SNAPSHOT/org.opendaylight.yangtools.yang.parser.stmt.reactor.BuildGlobalContext.transformEffective(BuildGlobalContext.java:261)
	... 76 more

One thing to note is that the two conditions listed above appear to be necessary but not sufficient because the error is not triggered predictably.

OpenDaylight JIRA

[YANGTOOLS-1474] Fail to process augmentation with empty grouping