/*

 * Copyright (c) 2016, 2017, 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 jdk.tools.jaotc;

import java.nio.ByteBuffer;

import java.nio.ByteOrder;

import jdk.tools.jaotc.binformat.BinaryContainer;

import jdk.tools.jaotc.binformat.Relocation;

import jdk.tools.jaotc.binformat.Relocation.RelocType;

import jdk.tools.jaotc.binformat.Symbol;

import jdk.tools.jaotc.binformat.Symbol.Binding;

import jdk.tools.jaotc.binformat.Symbol.Kind;

import jdk.tools.jaotc.AOTCompiledClass;

import org.graalvm.compiler.code.DataSection;

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

import jdk.vm.ci.code.TargetDescription;

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

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

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

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

import jdk.vm.ci.hotspot.HotSpotConstantPoolObject;

import jdk.vm.ci.hotspot.HotSpotMetaspaceConstant;

import jdk.vm.ci.hotspot.HotSpotObjectConstant;

import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;

import jdk.vm.ci.hotspot.HotSpotSentinelConstant;

import jdk.vm.ci.meta.VMConstant;

final class DataPatchProcessor {

    private final TargetDescription target;

    private final BinaryContainer binaryContainer;

    DataPatchProcessor(DataBuilder dataBuilder) {

        this.target = dataBuilder.getBackend().getTarget();

        this.binaryContainer = dataBuilder.getBinaryContainer();

    }

    /**

     * Process a {@link DataPatch} generated by the compiler and create all needed binary section

     * constructs.

     */

    void process(CompiledMethodInfo methodInfo, DataPatch dataPatch) {

        Reference reference = dataPatch.reference;

        if (reference instanceof ConstantReference) {

            processConstantReference(dataPatch, methodInfo);

        } else if (reference instanceof DataSectionReference) {

            processDataSectionReference(dataPatch, methodInfo);

        } else {

            throw new InternalError("Unknown data patch reference: " + reference);

        }

    }

    private void processConstantReference(DataPatch dataPatch, CompiledMethodInfo methodInfo) {

        HotSpotConstantLoadAction action = (HotSpotConstantLoadAction) dataPatch.note;

        ConstantReference constantReference = (ConstantReference) dataPatch.reference;

        assert action != null : "action should be set";

        VMConstant constant = constantReference.getConstant();

        String targetSymbol = null;

        String gotName = null;

        if (constant instanceof HotSpotMetaspaceConstant) {

            HotSpotMetaspaceConstant metaspaceConstant = (HotSpotMetaspaceConstant) constant;

            if (metaspaceConstant.asResolvedJavaType() != null) {

                HotSpotResolvedObjectType type = metaspaceConstant.asResolvedJavaType();

                methodInfo.addDependentKlassData(binaryContainer, type);

                targetSymbol = AOTCompiledClass.metadataName(type);

                gotName = ((action == HotSpotConstantLoadAction.INITIALIZE) ? "got.init." : "got.") + targetSymbol;

            } else if (metaspaceConstant.asResolvedJavaMethod() != null && action == HotSpotConstantLoadAction.LOAD_COUNTERS) {

                targetSymbol = "counters." + JavaMethodInfo.uniqueMethodName(metaspaceConstant.asResolvedJavaMethod());

                gotName = "got." + targetSymbol;

                binaryContainer.addCountersSymbol(targetSymbol);

            }

        } else if (constant instanceof HotSpotObjectConstant) {

            HotSpotObjectConstant oopConstant = (HotSpotObjectConstant) constant;

            if (oopConstant instanceof HotSpotConstantPoolObject) {

                HotSpotConstantPoolObject cpo = (HotSpotConstantPoolObject)oopConstant;

                // Even if two locations use the same object, resolve separately

                targetSymbol = "ldc." + cpo.getCpType().getName() + cpo.getCpi();

            } else {

                // String constant.

                targetSymbol = "ldc." + oopConstant.toValueString();

            }

            Integer offset = binaryContainer.addOopSymbol(targetSymbol);

            gotName = "got.ldc." + offset;

        } else if (constant instanceof HotSpotSentinelConstant) {

            targetSymbol = "state.M" + methodInfo.getCodeId();

            gotName = "got." + targetSymbol;

        }

        assert gotName != null : "Unknown constant type: " + constant;

        InstructionDecoder decoder = InstructionDecoder.getInstructionDecoder(target);

        decoder.decodePosition(methodInfo.getCompilationResult().getTargetCode(), dataPatch.pcOffset);

        int instructionEndOffset = decoder.currentEndOfInstruction();

        int textBaseOffset = methodInfo.getTextSectionOffset();

        int relocOffset = textBaseOffset + instructionEndOffset;

        Symbol relocationSymbol = binaryContainer.getSymbol(gotName);

        assert relocationSymbol != null : "symbol for " + gotName + " missing";

        Relocation reloc = new Relocation(relocOffset, RelocType.METASPACE_GOT_REFERENCE, 0, binaryContainer.getCodeContainer(), relocationSymbol);

        binaryContainer.addRelocation(reloc);

    }

    private void processDataSectionReference(DataPatch dataPatch, CompiledMethodInfo methodInfo) {

        DataSectionReference dataReference = (DataSectionReference) dataPatch.reference;

        InstructionDecoder decoder = InstructionDecoder.getInstructionDecoder(target);

        decoder.decodePosition(methodInfo.getCompilationResult().getTargetCode(), dataPatch.pcOffset);

        int instructionEndOffset = decoder.currentEndOfInstruction();

        int textBaseOffset = methodInfo.getTextSectionOffset();

        int relocOffset = textBaseOffset + instructionEndOffset;

        int dataOffset = dataReference.getOffset();

        DataSection dataSection = methodInfo.getCompilationResult().getDataSection();

        DataSection.Data data = dataSection.findData(dataReference);

        int size = data.getSize();

        int alignment = data.getAlignment();

        byte[] value = new byte[size];

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

        });

        String targetSymbol = "data.M" + methodInfo.getCodeId() + "." + dataOffset;

        Symbol relocationSymbol = binaryContainer.getSymbol(targetSymbol);

        if (relocationSymbol == null) {

            int symSize = Math.max(8, size);

            int symAlig = Math.max(8, alignment);

            int offsetInConstantDataSection = binaryContainer.addConstantData(value, symAlig);

            relocationSymbol = binaryContainer.getConstantDataContainer().createSymbol(offsetInConstantDataSection, Kind.OBJECT, Binding.LOCAL, symSize, targetSymbol);

        }

        Relocation reloc = new Relocation(relocOffset, RelocType.METASPACE_GOT_REFERENCE, 0, binaryContainer.getCodeContainer(), relocationSymbol);

        binaryContainer.addRelocation(reloc);

    }

}