/*

 * Copyright (c) 2018, 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.hotspot;

import static jdk.vm.ci.runtime.JVMCI.getRuntime;

import static jdk.vm.ci.services.Services.IS_BUILDING_NATIVE_IMAGE;

import static jdk.vm.ci.services.Services.IS_IN_NATIVE_IMAGE;

import static org.graalvm.compiler.core.common.GraalOptions.UseEncodedGraphs;

import static org.graalvm.compiler.nodes.graphbuilderconf.InlineInvokePlugin.InlineInfo.createIntrinsicInlineInfo;

import static org.graalvm.compiler.nodes.graphbuilderconf.IntrinsicContext.CompilationContext.INLINE_AFTER_PARSING;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Objects;

import java.util.Set;

import java.util.concurrent.ConcurrentHashMap;

import org.graalvm.compiler.api.replacements.Fold;

import org.graalvm.compiler.api.replacements.MethodSubstitution;

import org.graalvm.compiler.api.replacements.Snippet;

import org.graalvm.compiler.api.replacements.SnippetReflectionProvider;

import org.graalvm.compiler.api.runtime.GraalJVMCICompiler;

import org.graalvm.compiler.api.runtime.GraalRuntime;

import org.graalvm.compiler.bytecode.BytecodeProvider;

import org.graalvm.compiler.bytecode.ResolvedJavaMethodBytecode;

import org.graalvm.compiler.core.common.type.AbstractObjectStamp;

import org.graalvm.compiler.core.common.type.Stamp;

import org.graalvm.compiler.core.common.type.StampPair;

import org.graalvm.compiler.core.common.type.SymbolicJVMCIReference;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.debug.GraalError;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.graph.NodeMap;

import org.graalvm.compiler.graph.NodeSourcePosition;

import org.graalvm.compiler.hotspot.meta.HotSpotForeignCallsProvider;

import org.graalvm.compiler.hotspot.meta.HotSpotProviders;

import org.graalvm.compiler.java.BytecodeParser;

import org.graalvm.compiler.java.GraphBuilderPhase;

import org.graalvm.compiler.nodeinfo.Verbosity;

import org.graalvm.compiler.nodes.CallTargetNode;

import org.graalvm.compiler.nodes.Cancellable;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.EncodedGraph;

import org.graalvm.compiler.nodes.FrameState;

import org.graalvm.compiler.nodes.FullInfopointNode;

import org.graalvm.compiler.nodes.GraphEncoder;

import org.graalvm.compiler.nodes.ParameterNode;

import org.graalvm.compiler.nodes.ProxyNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.cfg.Block;

import org.graalvm.compiler.nodes.graphbuilderconf.GeneratedInvocationPlugin;

import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderConfiguration;

import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext;

import org.graalvm.compiler.nodes.graphbuilderconf.InlineInvokePlugin;

import org.graalvm.compiler.nodes.graphbuilderconf.IntrinsicContext;

import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugin;

import org.graalvm.compiler.nodes.graphbuilderconf.InvocationPlugins;

import org.graalvm.compiler.nodes.graphbuilderconf.MethodSubstitutionPlugin;

import org.graalvm.compiler.nodes.graphbuilderconf.NodePlugin;

import org.graalvm.compiler.nodes.graphbuilderconf.ParameterPlugin;

import org.graalvm.compiler.nodes.java.AccessFieldNode;

import org.graalvm.compiler.nodes.java.MethodCallTargetNode;

import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;

import org.graalvm.compiler.options.OptionValues;

import org.graalvm.compiler.phases.OptimisticOptimizations;

import org.graalvm.compiler.phases.schedule.SchedulePhase;

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

import org.graalvm.compiler.replacements.ConstantBindingParameterPlugin;

import org.graalvm.compiler.replacements.PEGraphDecoder;

import org.graalvm.compiler.replacements.ReplacementsImpl;

import org.graalvm.compiler.replacements.SnippetCounter;

import org.graalvm.compiler.replacements.SnippetIntegerHistogram;

import jdk.vm.ci.code.TargetDescription;

import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;

import jdk.vm.ci.hotspot.HotSpotResolvedJavaField;

import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;

import jdk.vm.ci.hotspot.HotSpotResolvedJavaType;

import jdk.vm.ci.hotspot.HotSpotSignature;

import jdk.vm.ci.meta.Constant;

import jdk.vm.ci.meta.ConstantReflectionProvider;

import jdk.vm.ci.meta.JavaConstant;

import jdk.vm.ci.meta.JavaKind;

import jdk.vm.ci.meta.MemoryAccessProvider;

import jdk.vm.ci.meta.MethodHandleAccessProvider;

import jdk.vm.ci.meta.ResolvedJavaField;

import jdk.vm.ci.meta.ResolvedJavaMethod;

import jdk.vm.ci.meta.ResolvedJavaType;

import jdk.vm.ci.meta.UnresolvedJavaField;

import jdk.vm.ci.meta.UnresolvedJavaMethod;

import jdk.vm.ci.meta.UnresolvedJavaType;

/**

 * This class performs graph encoding using {@link GraphEncoder} but also converts JVMCI type and

 * method references into a symbolic form that can be resolved at graph decode time using

 * {@link SymbolicJVMCIReference}.

 */

public class SymbolicSnippetEncoder {

    /**

     * This is a customized HotSpotReplacementsImpl intended only for parsing snippets and method

     * substitutions for graph encoding.

     */

    private final HotSpotSnippetReplacementsImpl snippetReplacements;

    /**

     * The set of all snippet methods that have been encoded.

     */

    private final Set<ResolvedJavaMethod> snippetMethods = Collections.synchronizedSet(new HashSet<>());

    /**

     * A mapping from the method substitution method to the original method name. The string key and

     * values are produced using {@link #methodKey(ResolvedJavaMethod)}.

     */

    private final Map<String, String> originalMethods = new ConcurrentHashMap<>();

    private final HotSpotReplacementsImpl originalReplacements;

    /**

     * The current count of graphs encoded. Used to detect when new graphs have been enqueued for

     * encoding.

     */

    private int encodedGraphs = 0;

    /**

     * All the graphs parsed so far.

     */

    private Map<String, StructuredGraph> preparedSnippetGraphs = new HashMap<>();

    /**

     * The invocation plugins which were delayed during graph preparation.

     */

    private Set<ResolvedJavaMethod> delayedInvocationPluginMethods = new HashSet<>();

    void addDelayedInvocationPluginMethod(ResolvedJavaMethod method) {

        delayedInvocationPluginMethods.add(method);

    }

    Set<ResolvedJavaMethod> getSnippetMethods() {

        return snippetMethods;

    }

    protected class SnippetInlineInvokePlugin implements InlineInvokePlugin {

        @Override

        public InlineInfo shouldInlineInvoke(GraphBuilderContext b, ResolvedJavaMethod method, ValueNode[] args) {

            if (method.getAnnotation(Fold.class) != null) {

                delayedInvocationPluginMethods.add(method);

                return InlineInfo.DO_NOT_INLINE_NO_EXCEPTION;

            }

            if (snippetReplacements.getIntrinsifyingPlugin(method) != null) {

                delayedInvocationPluginMethods.add(method);

                return InlineInfo.DO_NOT_INLINE_NO_EXCEPTION;

            }

            // Force inlining when parsing replacements

            return createIntrinsicInlineInfo(method, snippetReplacements.getDefaultReplacementBytecodeProvider());

        }

        @Override

        public void notifyAfterInline(ResolvedJavaMethod methodToInline) {

            assert methodToInline.getAnnotation(Fold.class) == null : methodToInline;

        }

    }

    public static class SnippetInvocationPlugins extends InvocationPlugins {

        SnippetInvocationPlugins(InvocationPlugins invocationPlugins) {

            super(invocationPlugins);

        }

        @Override

        public InvocationPlugin lookupInvocation(ResolvedJavaMethod method) {

            if (method.getAnnotation(Fold.class) != null) {

                return null;

            }

            return super.lookupInvocation(method);

        }

    }

    /**

     * This plugin disables the snippet counter machinery.

     */

    private class SnippetCounterPlugin implements NodePlugin {

        String snippetCounterName = 'L' + SnippetCounter.class.getName().replace('.', '/') + ';';

        String snippetIntegerHistogramName = 'L' + SnippetIntegerHistogram.class.getName().replace('.', '/') + ';';

        @Override

        public boolean handleLoadField(GraphBuilderContext b, ValueNode object, ResolvedJavaField field) {

            if (field.getName().equals("group") && field.getDeclaringClass().getName().equals(snippetCounterName)) {

                b.addPush(JavaKind.Object, ConstantNode.forConstant(JavaConstant.NULL_POINTER, b.getMetaAccess()));

                return true;

            }

            if (field.getType().getName().equals(snippetCounterName)) {

                b.addPush(JavaKind.Object, ConstantNode.forConstant(snippetReplacements.snippetReflection.forObject(SnippetCounter.DISABLED_COUNTER), b.getMetaAccess()));

                return true;

            }

            if (field.getType().getName().equals(snippetIntegerHistogramName)) {

                b.addPush(JavaKind.Object, ConstantNode.forConstant(snippetReplacements.snippetReflection.forObject(SnippetIntegerHistogram.DISABLED_COUNTER), b.getMetaAccess()));

                return true;

            }

            return false;

        }

    }

    /**

     * Generate a String name for a method including all type information. Used as a symbolic key

     * for lookup.

     */

    private static String methodKey(ResolvedJavaMethod method) {

    }

    SymbolicSnippetEncoder(HotSpotReplacementsImpl replacements) {

        this.originalReplacements = replacements;

        GraphBuilderConfiguration.Plugins plugins = replacements.getGraphBuilderPlugins();

        SnippetInvocationPlugins invocationPlugins = new SnippetInvocationPlugins(plugins.getInvocationPlugins());

        GraphBuilderConfiguration.Plugins copy = new GraphBuilderConfiguration.Plugins(plugins, invocationPlugins);

        copy.clearInlineInvokePlugins();

        copy.appendInlineInvokePlugin(new SnippetInlineInvokePlugin());

        copy.appendNodePlugin(new SnippetCounterPlugin());

        HotSpotProviders providers = (HotSpotProviders) replacements.getProviders().copyWith(new HotSpotSubstrateConstantReflectionProvider(replacements.getProviders().getConstantReflection()));

        this.snippetReplacements = new HotSpotSnippetReplacementsImpl(replacements, providers.copyWith(copy));

        this.snippetReplacements.setGraphBuilderPlugins(copy);

    }

    /**

     * Compiles the snippet and stores the graph.

     */

        ResolvedJavaMethod method = plugin.getSubstitute(snippetReplacements.getProviders().getMetaAccess());

        assert method.getAnnotation(MethodSubstitution.class) != null : "MethodSubstitution must be annotated with @" + MethodSubstitution.class.getSimpleName();

        snippetMethods.add(method);

        preparedSnippetGraphs.put(plugin.toString() + context, subst);

    }

    static class EncodedSnippets {

        private byte[] snippetEncoding;

        private Object[] snippetObjects;

        private NodeClass<?>[] snippetNodeClasses;

        private Map<String, Integer> snippetStartOffsets;

        private Map<String, String> originalMethods;

        EncodedSnippets(byte[] snippetEncoding, Object[] snippetObjects, NodeClass<?>[] snippetNodeClasses, Map<String, Integer> snippetStartOffsets, Map<String, String> originalMethods) {

            this.snippetEncoding = snippetEncoding;

            this.snippetObjects = snippetObjects;

            this.snippetNodeClasses = snippetNodeClasses;

            this.snippetStartOffsets = snippetStartOffsets;

            this.originalMethods = originalMethods;

        }

        StructuredGraph getMethodSubstitutionGraph(MethodSubstitutionPlugin plugin, ResolvedJavaMethod original, ReplacementsImpl replacements, IntrinsicContext.CompilationContext context,

                        StructuredGraph.AllowAssumptions allowAssumptions, Cancellable cancellable, OptionValues options) {

            Integer startOffset = snippetStartOffsets.get(plugin.toString() + context);

            if (startOffset == null) {

                throw GraalError.shouldNotReachHere("plugin graph not found: " + plugin + " with " + context);

            }

            ResolvedJavaType accessingClass = replacements.getProviders().getMetaAccess().lookupJavaType(plugin.getDeclaringClass());

            return decodeGraph(original, accessingClass, startOffset, replacements, context, allowAssumptions, cancellable, options);

        }

        @SuppressWarnings("try")

        private StructuredGraph decodeGraph(ResolvedJavaMethod method,

                        ResolvedJavaType accessingClass,

                        int startOffset,

                        ReplacementsImpl replacements,

                        IntrinsicContext.CompilationContext context,

                        StructuredGraph.AllowAssumptions allowAssumptions,

                        Cancellable cancellable,

                        OptionValues options) {

            Providers providers = replacements.getProviders();

            EncodedGraph encodedGraph = new SymbolicEncodedGraph(snippetEncoding, startOffset, snippetObjects, snippetNodeClasses,

                            methodKey(method), accessingClass, method.getDeclaringClass());

            try (DebugContext debug = replacements.openDebugContext("SVMSnippet_", method, options)) {

                StructuredGraph result = new StructuredGraph.Builder(options, debug, allowAssumptions).cancellable(cancellable).method(method).setIsSubstitution(true).build();

                PEGraphDecoder graphDecoder = new SubstitutionGraphDecoder(providers, result, replacements, null, method, context, encodedGraph);

                graphDecoder.decode(method, result.isSubstitution(), encodedGraph.trackNodeSourcePosition());

                assert result.verify();

                return result;

            }

        }

        StructuredGraph getEncodedSnippet(ResolvedJavaMethod method, ReplacementsImpl replacements, Object[] args, StructuredGraph.AllowAssumptions allowAssumptions, OptionValues options) {

            Integer startOffset = null;

            if (snippetStartOffsets != null) {

                startOffset = snippetStartOffsets.get(methodKey(method));

            }

            if (startOffset == null) {

                if (IS_IN_NATIVE_IMAGE) {

                    throw GraalError.shouldNotReachHere("snippet not found: " + method.format("%H.%n(%p)"));

                } else {

                    return null;

                }

            }

            SymbolicEncodedGraph encodedGraph = new SymbolicEncodedGraph(snippetEncoding, startOffset, snippetObjects, snippetNodeClasses,

                            originalMethods.get(methodKey(method)), method.getDeclaringClass());

            return decodeSnippetGraph(encodedGraph, method, replacements, args, allowAssumptions, options);

        }

    }

    private static class SubstitutionGraphDecoder extends PEGraphDecoder {

        private final ResolvedJavaMethod method;

        private final EncodedGraph encodedGraph;

        private IntrinsicContext intrinsic;

        SubstitutionGraphDecoder(Providers providers, StructuredGraph result, ReplacementsImpl replacements, ParameterPlugin parameterPlugin, ResolvedJavaMethod method,

                        IntrinsicContext.CompilationContext context, EncodedGraph encodedGraph) {

            super(providers.getCodeCache().getTarget().arch, result, providers, null,

                            replacements.getGraphBuilderPlugins().getInvocationPlugins(), new InlineInvokePlugin[0], parameterPlugin,

                            null, null, null, null);

            this.method = method;

            this.encodedGraph = encodedGraph;

            intrinsic = new IntrinsicContext(method, null, replacements.getDefaultReplacementBytecodeProvider(), context, false);

        }

        @Override

        protected EncodedGraph lookupEncodedGraph(ResolvedJavaMethod lookupMethod,

                        MethodSubstitutionPlugin plugin,

                        BytecodeProvider intrinsicBytecodeProvider,

                        boolean isSubstitution,

                        boolean trackNodeSourcePosition) {

            if (lookupMethod.equals(method)) {

                return encodedGraph;

            } else {

                throw GraalError.shouldNotReachHere(method.format("%H.%n(%p)"));

            }

        }

        @Override

        protected IntrinsicContext getIntrinsic() {

            return intrinsic;

        }

    }

                    IntrinsicContext.CompilationContext context, OptionValues options) {

        assert method.hasBytecodes() : "Snippet must not be abstract or native";

        Object[] args = null;

        if (receiver != null) {

            args = new Object[method.getSignature().getParameterCount(true)];

            args[0] = receiver;

        }

            StructuredGraph graph = snippetReplacements.makeGraph(debug, snippetReplacements.getDefaultReplacementBytecodeProvider(), method, args, original, trackNodeSourcePosition, null, context);

            // Check if all methods which should be inlined are really inlined.

            for (MethodCallTargetNode callTarget : graph.getNodes(MethodCallTargetNode.TYPE)) {

                ResolvedJavaMethod callee = callTarget.targetMethod();

                if (requireInlining && !delayedInvocationPluginMethods.contains(callee) && !Objects.equals(callee, original)) {

                    throw GraalError.shouldNotReachHere("method " + callee.format("%H.%n") + " not inlined in snippet " + method.getName() + " (maybe not final?)");

                }

            }

            debug.dump(DebugContext.VERBOSE_LEVEL, graph, "After buildGraph");

            return graph;

        }

    }

    @SuppressWarnings("try")

    private static StructuredGraph decodeSnippetGraph(SymbolicEncodedGraph encodedGraph, ResolvedJavaMethod method, ReplacementsImpl replacements, Object[] args,

                    StructuredGraph.AllowAssumptions allowAssumptions, OptionValues options) {

        Providers providers = replacements.getProviders();

        ParameterPlugin parameterPlugin = null;

        if (args != null) {

            parameterPlugin = new ConstantBindingParameterPlugin(args, providers.getMetaAccess(), replacements.snippetReflection);

        }

        try (DebugContext debug = replacements.openDebugContext("SVMSnippet_", method, options)) {

            // @formatter:off

            StructuredGraph result = new StructuredGraph.Builder(options, debug, allowAssumptions)

                    .method(method)

                    .trackNodeSourcePosition(encodedGraph.trackNodeSourcePosition())

                    .setIsSubstitution(true)

                    .build();

            // @formatter:on

            try (DebugContext.Scope scope = debug.scope("DecodeSnippetGraph", result)) {

                PEGraphDecoder graphDecoder = new SubstitutionGraphDecoder(providers, result, replacements, parameterPlugin, method, INLINE_AFTER_PARSING, encodedGraph);

                graphDecoder.decode(method, result.isSubstitution(), encodedGraph.trackNodeSourcePosition());

                debug.dump(DebugContext.VERBOSE_LEVEL, result, "After decoding");

                assert result.verify();

                return result;

            } catch (Throwable t) {

                throw debug.handle(t);

            }

        }

    }

    @SuppressWarnings("try")

        // Verify the encoding and decoding process

        EncodedGraph encodedGraph = GraphEncoder.encodeSingleGraph(graph, HotSpotJVMCIRuntime.runtime().getHostJVMCIBackend().getTarget().arch);

            }

        }

        return true;

    }

    /**

     * If there are new graphs waiting to be encoded, reencode all the graphs and return the result.

     */

    @SuppressWarnings("try")

    private synchronized EncodedSnippets maybeEncodeSnippets(OptionValues options) {