/*

 * Copyright (c) 2012, 2016, 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 java.nio.ByteBuffer;

import java.nio.ByteOrder;

import java.util.ArrayList;

import java.util.Collections;

import java.util.Comparator;

import java.util.EnumMap;

import java.util.List;

import java.util.Map;

import java.util.stream.Stream;

import java.util.stream.Stream.Builder;

import org.graalvm.compiler.code.CompilationResult;

import org.graalvm.compiler.code.CompilationResult.CodeAnnotation;

import org.graalvm.compiler.code.CompilationResult.CodeComment;

import org.graalvm.compiler.code.CompilationResult.JumpTable;

import org.graalvm.compiler.debug.GraalError;

import org.graalvm.compiler.code.DataSection;

import org.graalvm.compiler.code.SourceMapping;

import org.graalvm.compiler.graph.NodeSourcePosition;

import jdk.vm.ci.code.CodeCacheProvider;

import jdk.vm.ci.code.DebugInfo;

import jdk.vm.ci.code.StackSlot;

import jdk.vm.ci.code.site.ConstantReference;

import jdk.vm.ci.code.site.DataPatch;

import jdk.vm.ci.code.site.Infopoint;

import jdk.vm.ci.code.site.InfopointReason;

import jdk.vm.ci.code.site.Mark;

import jdk.vm.ci.code.site.Site;

import jdk.vm.ci.hotspot.HotSpotCompilationRequest;

import jdk.vm.ci.hotspot.HotSpotCompiledCode;

import jdk.vm.ci.hotspot.HotSpotCompiledCode.Comment;

import jdk.vm.ci.hotspot.HotSpotCompiledNmethod;

import jdk.vm.ci.hotspot.HotSpotObjectConstant;

import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;

import jdk.vm.ci.meta.Assumptions.Assumption;

import jdk.vm.ci.meta.ResolvedJavaMethod;

public class HotSpotCompiledCodeBuilder {

    public static HotSpotCompiledCode createCompiledCode(CodeCacheProvider codeCache, ResolvedJavaMethod method, HotSpotCompilationRequest compRequest, CompilationResult compResult) {

        String name = compResult.getName();

        byte[] targetCode = compResult.getTargetCode();

        int targetCodeSize = compResult.getTargetCodeSize();

        Site[] sites = getSortedSites(codeCache, compResult);

        Assumption[] assumptions = compResult.getAssumptions();

        ResolvedJavaMethod[] methods = compResult.getMethods();

        List<CodeAnnotation> annotations = compResult.getAnnotations();

        Comment[] comments = new Comment[annotations.size()];

        if (!annotations.isEmpty()) {

            for (int i = 0; i < comments.length; i++) {

                CodeAnnotation annotation = annotations.get(i);

                String text;

                if (annotation instanceof CodeComment) {

                    CodeComment codeComment = (CodeComment) annotation;

                    text = codeComment.value;

                } else if (annotation instanceof JumpTable) {

                    JumpTable jumpTable = (JumpTable) annotation;

                    text = "JumpTable [" + jumpTable.low + " .. " + jumpTable.high + "]";

                } else {

                    text = annotation.toString();

                }

                comments[i] = new Comment(annotation.position, text);

            }

        }

        DataSection data = compResult.getDataSection();

        byte[] dataSection = new byte[data.getSectionSize()];

        ByteBuffer buffer = ByteBuffer.wrap(dataSection).order(ByteOrder.nativeOrder());

        Builder<DataPatch> patchBuilder = Stream.builder();

        });

        int dataSectionAlignment = data.getSectionAlignment();

        DataPatch[] dataSectionPatches = patchBuilder.build().toArray(len -> new DataPatch[len]);

        int totalFrameSize = compResult.getTotalFrameSize();

        StackSlot customStackArea = compResult.getCustomStackArea();

        boolean isImmutablePIC = compResult.isImmutablePIC();

        if (method instanceof HotSpotResolvedJavaMethod) {

            HotSpotResolvedJavaMethod hsMethod = (HotSpotResolvedJavaMethod) method;

            int entryBCI = compResult.getEntryBCI();

            boolean hasUnsafeAccess = compResult.hasUnsafeAccess();

            int id;

            long jvmciEnv;

            if (compRequest != null) {

                id = compRequest.getId();

                jvmciEnv = compRequest.getJvmciEnv();

            } else {

                id = hsMethod.allocateCompileId(entryBCI);

                jvmciEnv = 0L;

            }

            return new HotSpotCompiledNmethod(name, targetCode, targetCodeSize, sites, assumptions, methods, comments, dataSection, dataSectionAlignment, dataSectionPatches, isImmutablePIC,

                            totalFrameSize, customStackArea, hsMethod, entryBCI, id, jvmciEnv, hasUnsafeAccess);

        } else {

            return new HotSpotCompiledCode(name, targetCode, targetCodeSize, sites, assumptions, methods, comments, dataSection, dataSectionAlignment, dataSectionPatches, isImmutablePIC,

                            totalFrameSize, customStackArea);

        }

    }

    static class SiteComparator implements Comparator<Site> {

        /**

         * Defines an order for sorting {@link Infopoint}s based on their

         * {@linkplain Infopoint#reason reasons}. This is used to choose which infopoint to preserve

         * when multiple infopoints collide on the same PC offset. A negative order value implies a

         * non-optional infopoint (i.e., must be preserved).

         */

        static final Map<InfopointReason, Integer> HOTSPOT_INFOPOINT_SORT_ORDER = new EnumMap<>(InfopointReason.class);

        static {

            HOTSPOT_INFOPOINT_SORT_ORDER.put(InfopointReason.SAFEPOINT, -4);

            HOTSPOT_INFOPOINT_SORT_ORDER.put(InfopointReason.CALL, -3);

            HOTSPOT_INFOPOINT_SORT_ORDER.put(InfopointReason.IMPLICIT_EXCEPTION, -2);

            HOTSPOT_INFOPOINT_SORT_ORDER.put(InfopointReason.METHOD_START, 2);

            HOTSPOT_INFOPOINT_SORT_ORDER.put(InfopointReason.METHOD_END, 3);

            HOTSPOT_INFOPOINT_SORT_ORDER.put(InfopointReason.BYTECODE_POSITION, 4);

        }

        static int ord(Infopoint info) {

            return HOTSPOT_INFOPOINT_SORT_ORDER.get(info.reason);

        }

        static int checkCollision(Infopoint i1, Infopoint i2) {

            int o1 = ord(i1);

            int o2 = ord(i2);

            if (o1 < 0 && o2 < 0) {

                throw new GraalError("Non optional infopoints cannot collide: %s and %s", i1, i2);

            }

            return o1 - o2;

        }

        /**

         * Records whether any two {@link Infopoint}s had the same {@link Infopoint#pcOffset}.

         */

        boolean sawCollidingInfopoints;

        @Override

        public int compare(Site s1, Site s2) {

            if (s1.pcOffset == s2.pcOffset) {

                // Marks must come first since patching a call site

                // may need to know the mark denoting the call type

                // (see uses of CodeInstaller::_next_call_type).

                boolean s1IsMark = s1 instanceof Mark;

                boolean s2IsMark = s2 instanceof Mark;

                if (s1IsMark != s2IsMark) {

                    return s1IsMark ? -1 : 1;

                }

                // Infopoints must group together so put them after

                // other Site types.

                boolean s1IsInfopoint = s1 instanceof Infopoint;

                boolean s2IsInfopoint = s2 instanceof Infopoint;

                if (s1IsInfopoint != s2IsInfopoint) {

                    return s1IsInfopoint ? 1 : -1;

                }

                if (s1IsInfopoint) {

                    sawCollidingInfopoints = true;

                    return checkCollision((Infopoint) s1, (Infopoint) s2);

                }

            }

            return s1.pcOffset - s2.pcOffset;

        }

    }

    /**

     * HotSpot expects sites to be presented in ascending order of PC (see

     * {@code DebugInformationRecorder::add_new_pc_offset}). In addition, it expects

     * {@link Infopoint} PCs to be unique.

     */

    private static Site[] getSortedSites(CodeCacheProvider codeCache, CompilationResult target) {

        List<Site> sites = new ArrayList<>(

                        target.getExceptionHandlers().size() + target.getInfopoints().size() + target.getDataPatches().size() + target.getMarks().size() + target.getSourceMappings().size());

        sites.addAll(target.getExceptionHandlers());

        sites.addAll(target.getInfopoints());

        sites.addAll(target.getDataPatches());

        sites.addAll(target.getMarks());

        /*

         * Translate the source mapping into appropriate info points. In HotSpot only one position

         * can really be represented and recording the end PC seems to give the best results and

         * corresponds with what C1 and C2 do.

         */

        if (codeCache.shouldDebugNonSafepoints()) {

            for (SourceMapping source : target.getSourceMappings()) {

                sites.add(new Infopoint(source.getEndOffset(), new DebugInfo(source.getSourcePosition()), InfopointReason.BYTECODE_POSITION));

                assert verifySourcePositionReceivers(source.getSourcePosition());

            }

        }

        SiteComparator c = new SiteComparator();

        Collections.sort(sites, c);

        if (c.sawCollidingInfopoints) {

            Infopoint lastInfopoint = null;

            List<Site> copy = new ArrayList<>(sites.size());

            for (Site site : sites) {

                if (site instanceof Infopoint) {

                    Infopoint info = (Infopoint) site;

                    if (lastInfopoint == null || lastInfopoint.pcOffset != info.pcOffset) {

                        lastInfopoint = info;

                        copy.add(info);

                    } else {

                        // Omit this colliding infopoint

                        assert lastInfopoint.reason.compareTo(info.reason) <= 0;

                    }

                } else {

                    copy.add(site);

                }

            }

            sites = copy;

        }

        return sites.toArray(new Site[sites.size()]);

    }

    /**

     * Verifies that the captured receiver type agrees with the declared type of the method.

     */

    private static boolean verifySourcePositionReceivers(NodeSourcePosition start) {

        NodeSourcePosition pos = start;

        while (pos != null) {

            if (pos.getReceiver() != null) {

                assert ((HotSpotObjectConstant) pos.getReceiver()).asObject(pos.getMethod().getDeclaringClass()) != null;

            }

            pos = pos.getCaller();

        }

        return true;

    }

}