/*

 * Copyright (c) 2009, 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package org.graalvm.compiler.core.target;

import java.util.ArrayList;

import org.graalvm.compiler.code.CompilationResult;

import org.graalvm.compiler.core.common.CompilationIdentifier;

import org.graalvm.compiler.core.common.LIRKind;

import org.graalvm.compiler.core.common.alloc.RegisterAllocationConfig;

import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;

import org.graalvm.compiler.core.common.spi.ForeignCallsProvider;

import org.graalvm.compiler.core.gen.LIRCompilerBackend;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.lir.asm.CompilationResultBuilderFactory;

import org.graalvm.compiler.lir.phases.LIRSuites;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.options.OptionValues;

import org.graalvm.compiler.phases.tiers.SuitesProvider;

import org.graalvm.compiler.phases.tiers.TargetProvider;

import org.graalvm.compiler.phases.util.Providers;

import jdk.vm.ci.code.BailoutException;

import jdk.vm.ci.code.CodeCacheProvider;

import jdk.vm.ci.code.CompilationRequest;

import jdk.vm.ci.code.CompiledCode;

import jdk.vm.ci.code.InstalledCode;

import jdk.vm.ci.code.RegisterConfig;

import jdk.vm.ci.code.TargetDescription;

import jdk.vm.ci.code.ValueKindFactory;

import jdk.vm.ci.meta.ConstantReflectionProvider;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.MetaAccessProvider;

import jdk.vm.ci.meta.ResolvedJavaMethod;

/**

 * Represents a compiler backend for Graal.

 */

public abstract class Backend implements TargetProvider, ValueKindFactory<LIRKind> {

    private final Providers providers;

    private final ArrayList<CodeInstallationTaskFactory> codeInstallationTaskFactories;

    public static final ForeignCallDescriptor ARITHMETIC_FREM = new ForeignCallDescriptor("arithmeticFrem", float.class, float.class, float.class);

    public static final ForeignCallDescriptor ARITHMETIC_DREM = new ForeignCallDescriptor("arithmeticDrem", double.class, double.class, double.class);

    protected Backend(Providers providers) {

        this.providers = providers;

        this.codeInstallationTaskFactories = new ArrayList<>();

    }

    public synchronized void addCodeInstallationTask(CodeInstallationTaskFactory factory) {

        this.codeInstallationTaskFactories.add(factory);

    }

    public Providers getProviders() {

        return providers;

    }

    public CodeCacheProvider getCodeCache() {

        return providers.getCodeCache();

    }

    public MetaAccessProvider getMetaAccess() {

        return providers.getMetaAccess();

    }

    public ConstantReflectionProvider getConstantReflection() {

        return providers.getConstantReflection();

    }

    public ForeignCallsProvider getForeignCalls() {

        return providers.getForeignCalls();

    }

    public abstract SuitesProvider getSuites();

    @Override

    public TargetDescription getTarget() {

        return providers.getCodeCache().getTarget();

    }

    @Override

    public LIRKind getValueKind(JavaKind javaKind) {

        return LIRKind.fromJavaKind(getTarget().arch, javaKind);

    }

    /**

     * Creates a new configuration for register allocation.

     *

     * @param allocationRestrictedTo if not {@code null}, register allocation will be restricted to

     *            registers whose names appear in this array

     */

    public abstract RegisterAllocationConfig newRegisterAllocationConfig(RegisterConfig registerConfig, String[] allocationRestrictedTo);

    /**

     * Turns a Graal {@link CompilationResult} into a {@link CompiledCode} object that can be passed

     * to the VM for code installation.

     */

    protected abstract CompiledCode createCompiledCode(ResolvedJavaMethod method, CompilationRequest compilationRequest, CompilationResult compilationResult, boolean isDefault, OptionValues options);

    /**

     * @see #createInstalledCode(DebugContext, ResolvedJavaMethod, CompilationRequest,

     *      CompilationResult, InstalledCode, boolean, Object[])

     */

    public InstalledCode createInstalledCode(DebugContext debug,

                    ResolvedJavaMethod method,

                    CompilationResult compilationResult,

                    InstalledCode predefinedInstalledCode,

                    boolean isDefault) {

        return createInstalledCode(debug, method, null, compilationResult, predefinedInstalledCode, isDefault, null);

    }

    /**

     * @see #createInstalledCode(DebugContext, ResolvedJavaMethod, CompilationRequest,

     *      CompilationResult, InstalledCode, boolean, Object[])

     */

    @SuppressWarnings("try")

    public InstalledCode createInstalledCode(DebugContext debug,

                    ResolvedJavaMethod method,

                    CompilationRequest compilationRequest,

                    CompilationResult compilationResult,

                    InstalledCode predefinedInstalledCode,

                    boolean isDefault) {

        return createInstalledCode(debug, method, compilationRequest, compilationResult, predefinedInstalledCode, isDefault, null);

    }

    /**

     * Installs code based on a given compilation result.

     *

     * @param method the method compiled to produce {@code compiledCode} or {@code null} if the

     *            input to {@code compResult} was not a {@link ResolvedJavaMethod}

     * @param compilationRequest the compilation request or {@code null}

     * @param compilationResult the code to be installed

     * @param predefinedInstalledCode a pre-allocated {@link InstalledCode} object to use as a

     *            reference to the installed code. If {@code null}, a new {@link InstalledCode}

     *            object will be created.

     * @param isDefault specifies if the installed code should be made the default implementation of

     *            {@code compRequest.getMethod()}. The default implementation for a method is the

     *            code executed for standard calls to the method. This argument is ignored if

     *            {@code compRequest == null}.

     * @param context a custom debug context to use for the code installation

     * @return a reference to the compiled and ready-to-run installed code

     * @throws BailoutException if the code installation failed

     * @throws IllegalArgumentException if {@code installedCode != null} and this platform does not

     *             {@linkplain CodeCacheProvider#installCode support} a predefined

     *             {@link InstalledCode} object

     */

    @SuppressWarnings("try")

    public InstalledCode createInstalledCode(DebugContext debug,

                    ResolvedJavaMethod method,

                    CompilationRequest compilationRequest,

                    CompilationResult compilationResult,

                    InstalledCode predefinedInstalledCode,

                    boolean isDefault,

                    Object[] context) {

        Object[] debugContext = context != null ? context : new Object[]{getProviders().getCodeCache(), method, compilationResult};

        CodeInstallationTask[] tasks;

        synchronized (this) {

            tasks = new CodeInstallationTask[codeInstallationTaskFactories.size()];

            for (int i = 0; i < codeInstallationTaskFactories.size(); i++) {

                tasks[i] = codeInstallationTaskFactories.get(i).create();

            }

        }

        try (DebugContext.Scope s2 = debug.scope("CodeInstall", debugContext);

                        DebugContext.Activation a = debug.activate()) {

            InstalledCode installedCode;

            try {

                preCodeInstallationTasks(tasks, compilationResult);

                CompiledCode compiledCode = createCompiledCode(method, compilationRequest, compilationResult, isDefault, debug.getOptions());

                installedCode = getProviders().getCodeCache().installCode(method, compiledCode, predefinedInstalledCode, compilationResult.getSpeculationLog(), isDefault);

                assert predefinedInstalledCode == null || installedCode == predefinedInstalledCode;

            } catch (Throwable t) {

                failCodeInstallationTasks(tasks, t);

                throw t;

            }

            postCodeInstallationTasks(tasks, compilationResult, installedCode);

            return installedCode;

        } catch (Throwable e) {

            throw debug.handle(e);

        }

    }

    private static void failCodeInstallationTasks(CodeInstallationTask[] tasks, Throwable t) {

        for (CodeInstallationTask task : tasks) {

            task.installFailed(t);

        }

    }

    private static void preCodeInstallationTasks(CodeInstallationTask[] tasks, CompilationResult compilationResult) {

        for (CodeInstallationTask task : tasks) {

            task.preProcess(compilationResult);

        }

    }

    private static void postCodeInstallationTasks(CodeInstallationTask[] tasks, CompilationResult compilationResult, InstalledCode installedCode) {

        try {

            for (CodeInstallationTask task : tasks) {

                task.postProcess(compilationResult, installedCode);

            }

        } catch (Throwable t) {

            installedCode.invalidate();

            throw t;

        }

    }

    /**

     * Installs code based on a given compilation result.

     *

     * @param method the method compiled to produce {@code compiledCode} or {@code null} if the

     *            input to {@code compResult} was not a {@link ResolvedJavaMethod}

     * @param compilationRequest the request or {@code null}

     * @param compilationResult the compiled code

     * @return a reference to the compiled and ready-to-run installed code

     * @throws BailoutException if the code installation failed

     */

    public InstalledCode addInstalledCode(DebugContext debug,

                    ResolvedJavaMethod method,

                    CompilationRequest compilationRequest,

                    CompilationResult compilationResult) {

        return createInstalledCode(debug, method, compilationRequest, compilationResult, null, false);

    }

    /**

     * Installs code based on a given compilation result and sets it as the default code to be used

     * when {@code method} is invoked.

     *

     * @param method the method compiled to produce {@code compiledCode} or {@code null} if the

     *            input to {@code compResult} was not a {@link ResolvedJavaMethod}

     * @param compilationResult the compiled code

     * @return a reference to the compiled and ready-to-run installed code

     * @throws BailoutException if the code installation failed

     */

    public InstalledCode createDefaultInstalledCode(DebugContext debug, ResolvedJavaMethod method, CompilationResult compilationResult) {

        return createInstalledCode(debug, method, compilationResult, null, true);

    }

    /**

     * Gets the compilation id for a given {@link ResolvedJavaMethod}. Returns

     * {@code CompilationIdentifier#INVALID_COMPILATION_ID} in case there is no such id.

     *

     * @param resolvedJavaMethod

     */

    public CompilationIdentifier getCompilationIdentifier(ResolvedJavaMethod resolvedJavaMethod) {

        return CompilationIdentifier.INVALID_COMPILATION_ID;

    }

    public void emitBackEnd(StructuredGraph graph,

                    Object stub,

                    ResolvedJavaMethod installedCodeOwner,

                    CompilationResult compilationResult,

                    CompilationResultBuilderFactory factory,

                    RegisterConfig config, LIRSuites lirSuites) {

        LIRCompilerBackend.emitBackEnd(graph, stub, installedCodeOwner, this, compilationResult, factory, config, lirSuites);

    }

    /**

     * Encapsulates custom tasks done before and after code installation.

     */

    public abstract static class CodeInstallationTask {

        /**

         * Task to run before code installation.

         *

         * @param compilationResult the code about to be installed

         *

         */

        public void preProcess(CompilationResult compilationResult) {

        }

        /**

         * Task to run after the code is installed.

         *

         * @param compilationResult the code about to be installed

         * @param installedCode a reference to the installed code

         */

        public void postProcess(CompilationResult compilationResult, InstalledCode installedCode) {

        }

        /**

         * Invoked after {@link #preProcess} when code installation fails.

         *

         * @param cause the cause of the installation failure

         */

        public void installFailed(Throwable cause) {

        }

    }

    /**

     * Creates code installation tasks.

     */

    public abstract static class CodeInstallationTaskFactory {

        public abstract CodeInstallationTask create();

    }

}