/** Registers an action to copy Swift standard library dylibs into app bundle. */
  private void registerSwiftStdlibActionsIfNecessary() {
    if (!objcProvider.is(USES_SWIFT)) {
      return;
    }

    ObjcConfiguration objcConfiguration = ObjcRuleClasses.objcConfiguration(ruleContext);

    CustomCommandLine.Builder commandLine =
        CustomCommandLine.builder()
            .addPath(intermediateArtifacts.swiftFrameworksFileZip().getExecPath())
            .add("--platform")
            .add(IosSdkCommands.swiftPlatform(objcConfiguration))
            .addExecPath("--scan-executable", intermediateArtifacts.combinedArchitectureBinary());

    ruleContext.registerAction(
        ObjcRuleClasses.spawnOnDarwinActionBuilder(ruleContext)
            .setMnemonic("SwiftStdlibCopy")
            .setExecutable(attributes.swiftStdlibToolWrapper())
            .setCommandLine(commandLine.build())
            .addOutput(intermediateArtifacts.swiftFrameworksFileZip())
            .addInput(intermediateArtifacts.combinedArchitectureBinary())
            // TODO(dmaclach): Adding realpath and xcrunwrapper should not be required once
            // https://github.com/google/bazel/issues/285 is fixed.
            .addInput(attributes.realpath())
            .addInput(CompilationSupport.xcrunwrapper(ruleContext).getExecutable())
            .build(ruleContext));
  }