linkage-checker-exclusion-default.xml

<LinkageCheckerFilter>
  <LinkageError>
    <Source>
      <Package name="reactor.core.publisher.Traces" />
    </Source>
    <Reason>
      reactor-core's Traces catches Throwable to detect classes available in
      Java 9+. As Linkage Checker targets Java 8, it ignores these errors to avoid
      false positives.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/816
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="com.oracle.objectfile" />
    </Source>
    <Reason>
      GraalVM-related libraries depend on Java Compiler Interface (JVMCI) that
      only exists in special JDK. These missing classes are false positives, because
      the code is only invoked when running in a GraalVM.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/929
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="com.oracle.svm" />
    </Source>
    <Reason>
      GraalVM-related libraries depend on Java Compiler Interface (JVMCI) that
      only exists in special JDK. These missing classes are false positives, because
      the code is only invoked when running in a GraalVM.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/929
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="jdk.vm.ci" />
    </Target>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="jdk.vm.ci" />
    </Target>
    <Reason>
      Substrate VM is part of GraalVM and the virtual machine references classes in the JVM-internal
      package 'sun.text.normalizer' that are not available in JVM runtime.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1825
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="sun.text.normalizer" />
    </Target>
    <Source>
      <Package name="com.oracle.svm.core.jdk8" />
    </Source>
    <Reason>
      Substrate VM is part of GraalVM and the virtual machine references classes in the JVM-internal
      package 'sun.text.normalizer' that are not available in JVM runtime.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1825
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Class name="sun.util.logging.LoggingSupport" />
    </Target>
    <Source>
      <Class name="com.oracle.svm.core.jdk.FormatAccessors" />
    </Source>
    <Reason>
      Substrate VM references the JVM-internal class 'sun.util.logging.LoggingSupport' that are not
      available in JVM runtime.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1825
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Class name="sun.misc.JavaUtilZipFileAccess" />
    </Target>
    <Source>
      <Class name="com.oracle.svm.core.jdk8.zipfile.ZipFileUtil" />
    </Source>
    <Reason>
      Substrate VM references the class that are only available in Java 8.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1825
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Class name="sun.misc.SharedSecrets" />
    </Target>
    <Source>
      <Package name="com.oracle.svm.core.jdk8" />
    </Source>
    <Reason>
      Substrate VM references the class that are only available in Java 8.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1825
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Class name="sun.misc.PerfCounter" />
    </Target>
    <Source>
      <Package name="com.oracle.svm.core.jdk8" />
    </Source>
    <Reason>
      Substrate VM references the class that are only available in Java 8.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1825
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Class name="org.mockito.internal.creation.bytebuddy.MockMethodDispatcher" />
    </Target>
    <Source>
      <Package name="org.mockito.internal.creation.bytebuddy" />
    </Source>
    <Reason>
      Mockito's MockMethodDispatcher uses special class loader to load
      MockMethodDispatcher.raw. The class file with "raw" suffix is in mockito-core JAR file.
      Because Linkage Checker does not use the special class loader, it ignores the missing
      class errors to avoid false positives.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/407
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="com.sun.jna" />
    </Target>
    <Source>
      <Package name="reactor.blockhound.shaded.net.bytebuddy.agent.VirtualMachine" />
    </Source>
    <Reason>
      BlockHound shades ByteBuddy's VirtualMachine class. The class uses Java Native Access (JNA)
      only when the com.sun.jna package is available. Therefore the invalid references from the
      VirtualMachine class to JNA classes do not cause linkage errors at runtime.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1296
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="reactor.blockhound" />
    </Target>
    <Source>
      <Class name="io.netty.util.internal.Hidden" />
    </Source>
    <Reason>
      If BlockHound library is present in the class path, it loads the Hidden class to enable
      Netty-BlockHound integration. In this case, the target classes are on the class path.
      If BlockHound is not on the class path, nothing loads this source class.
      https://github.com/reactor/BlockHound/blob/master/docs/custom_integrations.md
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="reactor.blockhound" />
    </Target>
    <Source>
      <Class name="io.grpc.netty.shaded.io.netty.util.internal.Hidden" />
    </Source>
    <Reason>
      (For grpc-netty-shaded source)
      If BlockHound library is present in the class path, it loads the Hidden class to enable
      Netty-BlockHound integration. In this case, the target classes are on the class path.
      If BlockHound is not on the class path, nothing loads this source class.
      https://github.com/reactor/BlockHound/blob/master/docs/custom_integrations.md
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.netty.util.internal.logging" />
    </Source>
    <Reason>
      InternalLoggerFactory catches and handles errors caused by the missing classes.
      More details in https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1872
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.grpc.netty.shaded.io.netty.util.internal.logging" />
    </Source>
    <Reason>
      grpc-netty-shaded has copies of the netty's internal logging classes. which catches and
      handles errors caused by the missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.netty.handler.codec.marshalling" />
    </Source>
    <Reason>
      Netty users can optionally add JBoss Marshalling dependency to use
      io.netty.handler.codec.marshalling package when they need the serialization algorithm.
      By default, the classes in the package have references to missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.grpc.netty.shaded.io.netty.handler.codec.marshalling" />
    </Source>
    <Reason>
      (For grpc-netty-shaded source)
      Netty users can optionally add JBoss Marshalling dependency to use
      io.netty.handler.codec.marshalling package when they need the serialization algorithm.
      By default, the classes in the package have references to missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.netty.handler.codec.protobuf" />
    </Source>
    <Reason>
      Netty users can optionally add protobuf dependency to use io.netty.handler.codec.protobuf
      package when they need the serialization algorithm. By default, the classes in the package
      have references to missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.grpc.netty.shaded.io.netty.handler.codec.protobuf" />
    </Source>
    <Reason>
      (For grpc-netty-shaded source)
      Netty users can optionally add protobuf dependency to use io.netty.handler.codec.protobuf
      package when they need the serialization algorithm. By default, the classes in the package
      have references to missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.netty.handler.codec.compression" />
    </Source>
    <Reason>
      Netty users can optionally add corresponding dependencies to use compression algorithms (LZMA,
      LZF, zlib). By default, the classes in the package have references to missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="io.grpc.netty.shaded.io.netty.handler.codec.compression" />
    </Source>
    <Reason>
      (For grpc-netty-shaded source)
      Netty users can optionally add corresponding dependencies to use compression algorithms (LZMA,
      LZF, zlib). By default, the classes in the package have references to missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="io.netty.internal.tcnative" />
    </Target>
    <Source>
      <Package name="io.netty.handler.ssl" />
    </Source>
    <Reason>
      Netty users add the dependencies of platform-specific SSL implementations.
      https://netty.io/wiki/forked-tomcat-native.html#wiki-h2-4
      By default, the classes in the package have references to missing classes.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="com.jcraft.jzlib" />
    </Target>
    <Source>
      <Class name="io.netty.handler.codec.spdy.SpdyHeaderBlockJZlibEncoder" />
    </Source>
    <Reason>
      io.netty.handler.codec.spdy.SpdyHeaderBlockEncoder chooses the compression encoder based on
      the Java platform. For Java 7 or later, it does not use SpdyHeaderBlockJZlibEncoder, as the
      Zlib compression is available in JVM.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="com.jcraft.jzlib" />
    </Target>
    <Source>
      <Class name="io.grpc.netty.shaded.io.netty.handler.codec.spdy.SpdyHeaderBlockJZlibEncoder" />
    </Source>
    <Reason>
      (For grpc-netty-shaded source)LinkageCheckerMainIntegrationTest
      io.netty.handler.codec.spdy.SpdyHeaderBlockEncoder chooses the compression encoder based on
      the Java platform. For Java 7 or later, it does not use SpdyHeaderBlockJZlibEncoder, as the
      Zlib compression is available in JVM.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="org.bouncycastle" />
    </Target>
    <Source>
      <Class name="io.netty.handler.ssl.util.BouncyCastleSelfSignedCertGenerator" />
    </Source>
    <Reason>
      io.netty.handler.ssl.util.SelfSignedCertificate checks the availability of Bouncy Castle
      library (http://www.bouncycastle.org/). If it's unavailable, then Netty does not use the
      BouncyCastleSelfSignedCertGenerator.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="org.bouncycastle" />
    </Target>
    <Source>
      <Class name="io.grpc.netty.shaded.io.netty.handler.ssl.util.BouncyCastleSelfSignedCertGenerator" />
    </Source>
    <Reason>
      (For grpc-netty-shaded source)
      io.netty.handler.ssl.util.SelfSignedCertificate checks the availability of Bouncy Castle
      library (http://www.bouncycastle.org/). If it's unavailable, then Netty does not use the
      BouncyCastleSelfSignedCertGenerator.
    </Reason>
  </LinkageError>  <LinkageError>
    <Target>
      <Package name="org.eclipse.jetty.npn" />
    </Target>
    <Source>
      <Class name="io.netty.handler.ssl.JettyNpnSslEngine" />
    </Source>
    <Reason>
      The Jetty-ALPN and Jetty-NPN are the optional fallback method when Netty users cannot use
      OpenSSL with netty-tcnative. Therefore, the JettyNpnSslEngine class has linkage errors by
      default.
      https://netty.io/wiki/requirements-for-4.x.html#tls-with-jdk-jetty-alpnnpn
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="org.eclipse.jetty.npn" />
    </Target>
    <Source>
      <Class name="io.grpc.netty.shaded.io.netty.handler.ssl.JettyNpnSslEngine" />
    </Source>
    <Reason>
      (For grpc-netty-shaded source)
      The Jetty-ALPN and Jetty-NPN are the optional fallback method when Netty users cannot use
      OpenSSL with netty-tcnative. Therefore, the JettyNpnSslEngine class has linkage errors by
      default.
      https://netty.io/wiki/requirements-for-4.x.html#tls-with-jdk-jetty-alpnnpn
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="org.eclipse.jetty.alpn" />
    </Target>
    <Source>
      <Class name="io.netty.handler.ssl.JettyAlpnSslEngine" />
    </Source>
    <Reason>
      The Jetty-ALPN and Jetty-NPN are the optional fallback method when Netty users cannot use
      OpenSSL with netty-tcnative. Therefore, the JettyAlpnSslEngine class has linkage errors by
      default.
      https://netty.io/wiki/requirements-for-4.x.html#tls-with-jdk-jetty-alpnnpn
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="org.eclipse.jetty.alpn" />
    </Target>
    <Source>
      <Class name="io.grpc.netty.shaded.io.netty.handler.ssl.JettyAlpnSslEngine" />
    </Source>
    <Reason>
      The Jetty-ALPN and Jetty-NPN are the optional fallback method when Netty users cannot use
      OpenSSL with netty-tcnative. Therefore, the JettyAlpnSslEngine class has linkage errors by
      default.
      https://netty.io/wiki/requirements-for-4.x.html#tls-with-jdk-jetty-alpnnpn
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Method className="com.google.api.VisibilityProto" name="getDescriptor" />
    </Target>
    <Source>
      <Package name="com.google.appengine.repackaged.com.google" />
    </Source>
    <Reason>
      The appengine-api-1.0-sdk shades certain classes, creating method references that do not
      match original unshaded classes from the proto-google-common-protos artifact.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/2045
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Class name="org.apache.avalon.framework.logger.Logger" />
    </Target>
    <Source>
      <Class name="org.apache.commons.logging.impl.AvalonLogger" />
    </Source>
    <Reason>
      The AvalonLogger is used only when commons-logging users want to use Apache Avalon, which
      has been closed since 2004. For those who don't use Apache Avalon, the class references does
      not cause a problem.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1871
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="org.apache.log" />
    </Target>
    <Source>
      <Class name="org.apache.commons.logging.impl.LogKitLogger" />
    </Source>
    <Reason>
      The LogKitLogger is used only when commons-logging users want to use Apache Avalon, which
      has been closed since 2004. For those who don't use Apache Avalon, the class references does
      not cause a problem.
      https://github.com/GoogleCloudPlatform/cloud-opensource-java/issues/1871
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="sun.misc" />
    </Target>
    <Source>
      <Class name="com.google.common.flogger.util.JavaLangAccessStackGetter" />
    </Source>
    <Reason>
      Flogger's JavaLangAccessStackGetter and StackWalkerStackGetter trys to use available classes
      in different JDK versions. Certain classes are unavailable in a JDK.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Target>
      <Package name="java" />
    </Target>
    <Source>
      <Class name="com.google.common.flogger.util.StackWalkerStackGetter" />
    </Source>
    <Reason>
      Flogger's JavaLangAccessStackGetter and StackWalkerStackGetter trys to use available classes
      in different JDK versions. Certain classes are unavailable in a JDK.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="com.sun.mail.smtp" />
    </Source>
    <Reason>
      Google Cloud libraries do not use SMTP protocols. There are discrepancy in
      javax.mail:mail:1.4.3 com.sun.mail:javax.mail:1.6.2 in dependency graph.
    </Reason>
  </LinkageError>
  <LinkageError>
    <Source>
      <Package name="com.ctc.wstx.shaded" />
    </Source>
    <Target>
      <Class name="com.ctc.wstx.shaded.msv_core.driver.textui.Driver" />
    </Target>
    <Reason>
      Shaded class in com.fasterxml.woodstox:woodstox-core:6.2.6 has a class
      reference to the textui.Driver but the shading process didn't include it.
    </Reason>
  </LinkageError>
</LinkageCheckerFilter>