import org.gradle.api.Action;
import org.gradle.nativeplatform.toolchain.GccCommandLineToolConfiguration;
import org.gradle.nativeplatform.toolchain.internal.ToolType;

import java.util.List;

public interface GccCommandLineToolConfigurationInternal extends GccCommandLineToolConfiguration {

    ToolType getToolType();

    Action<List<String>> getArgAction();

        GccCommandLineToolConfigurationInternal symbolExtractor = toolRegistry.getTool(ToolType.SYMBOL_EXTRACTOR);
        return new SymbolExtractor(buildOperationExecutor, commandLineTool(symbolExtractor), context(symbolExtractor), workerLeaseService);
    }

    @Override
    protected Compiler<?> createStripper() {
        GccCommandLineToolConfigurationInternal stripper = toolRegistry.getTool(ToolType.STRIPPER);

    }

    @Nullable
    @Override
    public GccCommandLineToolConfigurationInternal getTool(ToolType toolType) {
        return tools.get(toolType);
    }

    public Collection<GccCommandLineToolConfigurationInternal> getTools() {
        return tools.values();
    }

    public Collection<GccCommandLineToolConfigurationInternal> getCompilers() {

import org.gradle.api.NonNullApi;
import org.gradle.nativeplatform.toolchain.internal.ToolType;

import javax.annotation.Nullable;

@NonNullApi
public interface ToolRegistry {
    @Nullable
    GccCommandLineToolConfigurationInternal getTool(ToolType toolType);

import org.gradle.nativeplatform.toolchain.internal.ToolType;

public class DefaultGccCommandLineToolConfiguration extends DefaultCommandLineToolConfiguration implements GccCommandLineToolConfigurationInternal {
    private String executable;

    public DefaultGccCommandLineToolConfiguration(ToolType toolType, String defaultExecutable) {
        super(toolType);
        this.executable = defaultExecutable;

import org.gradle.nativeplatform.toolchain.internal.tools.DefaultGccCommandLineToolConfiguration;
import org.gradle.nativeplatform.toolchain.internal.tools.GccCommandLineToolConfigurationInternal;
import org.gradle.nativeplatform.toolchain.internal.tools.ToolSearchPath;
import org.gradle.platform.base.internal.toolchain.SearchResult;
import org.gradle.platform.base.internal.toolchain.ToolChainAvailability;

            return "Test"
        }
    }

    def argsFor(GccCommandLineToolConfiguration tool) {
        assert tool instanceof GccCommandLineToolConfigurationInternal : "Expected argument to be an instance of GccCommandLineToolConfigurationInternal"
        def args = []
        tool.getArgAction().execute(args)
        args
    }

Class <org.gradle.nativeplatform.toolchain.internal.tools.GccCommandLineToolConfigurationInternal> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (GccCommandLineToolConfigurationInternal.java:0)