/*

 * Copyright (c) 2009, 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.code;

import static java.util.Collections.emptyList;

import static java.util.Collections.unmodifiableList;

import static jdk.vm.ci.meta.MetaUtil.identityHashCodeString;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Collections;

import java.util.List;

import java.util.Objects;

import org.graalvm.compiler.graph.NodeSourcePosition;

import jdk.vm.ci.code.DebugInfo;

import jdk.vm.ci.code.StackSlot;

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

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.ExceptionHandler;

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.Reference;

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

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

import jdk.vm.ci.meta.InvokeTarget;

import jdk.vm.ci.meta.ResolvedJavaField;

import jdk.vm.ci.meta.ResolvedJavaMethod;

/**

 * Represents the output from compiling a method, including the compiled machine code, associated

 * data and references, relocation information, deoptimization information, etc.

 */

public class CompilationResult {

    /**

     * Provides extra information about instructions or data at specific positions in

     * {@link CompilationResult#getTargetCode()}. This is optional information that can be used to

     * enhance a disassembly of the code.

     */

    public abstract static class CodeAnnotation {

        public final int position;

        public CodeAnnotation(int position) {

            this.position = position;

        }

        @Override

        public final int hashCode() {

            throw new UnsupportedOperationException("hashCode");

        }

        @Override

        public String toString() {

            return identityHashCodeString(this);

        }

        @Override

        public abstract boolean equals(Object obj);

    }

    /**

     * A string comment about one or more instructions at a specific position in the code.

     */

    public static final class CodeComment extends CodeAnnotation {

        public final String value;

        public CodeComment(int position, String comment) {

            super(position);

            this.value = comment;

        }

        @Override

        public boolean equals(Object obj) {

            if (this == obj) {

                return true;

            }

            if (obj instanceof CodeComment) {

                CodeComment that = (CodeComment) obj;

                if (this.position == that.position && this.value.equals(that.value)) {

                    return true;

                }

            }

            return false;

        }

        @Override

        public String toString() {

            return getClass().getSimpleName() + "@" + position + ": " + value;

        }

    }

    /**

     * Describes a table of signed offsets embedded in the code. The offsets are relative to the

     * starting address of the table. This type of table maybe generated when translating a

     * multi-way branch based on a key value from a dense value set (e.g. the {@code tableswitch}

     * JVM instruction).

     *

     * The table is indexed by the contiguous range of integers from {@link #low} to {@link #high}

     * inclusive.

     */

    public static final class JumpTable extends CodeAnnotation {

        /**

         * The low value in the key range (inclusive).

         */

        public final int low;

        /**

         * The high value in the key range (inclusive).

         */

        public final int high;

        /**

         * The size (in bytes) of each table entry.

         */

        public final int entrySize;

        public JumpTable(int position, int low, int high, int entrySize) {

            super(position);

            this.low = low;

            this.high = high;

            this.entrySize = entrySize;

        }

        @Override

        public boolean equals(Object obj) {

            if (this == obj) {

                return true;

            }

            if (obj instanceof JumpTable) {

                JumpTable that = (JumpTable) obj;

                if (this.position == that.position && this.entrySize == that.entrySize && this.low == that.low && this.high == that.high) {

                    return true;

                }

            }

            return false;

        }

        @Override

        public String toString() {

            return getClass().getSimpleName() + "@" + position + ": [" + low + " .. " + high + "]";

        }

    }

    private boolean closed;

    private int entryBCI = -1;

    private final DataSection dataSection = new DataSection();

    private final List<Infopoint> infopoints = new ArrayList<>();

    private final List<SourceMapping> sourceMapping = new ArrayList<>();

    private final List<DataPatch> dataPatches = new ArrayList<>();

    private final List<ExceptionHandler> exceptionHandlers = new ArrayList<>();

    private final List<Mark> marks = new ArrayList<>();

    private int totalFrameSize = -1;

    private int maxInterpreterFrameSize = -1;

    private StackSlot customStackArea = null;

    private final String name;

    /**

     * The buffer containing the emitted machine code.

     */

    private byte[] targetCode;

    /**

     * The leading number of bytes in {@link #targetCode} containing the emitted machine code.

     */

    private int targetCodeSize;

    private ArrayList<CodeAnnotation> annotations;

    private Assumption[] assumptions;

    /**

     * The list of the methods whose bytecodes were used as input to the compilation. If

     * {@code null}, then the compilation did not record method dependencies. Otherwise, the first

     * element of this array is the root method of the compilation.

     */

    private ResolvedJavaMethod[] methods;

    /**

     * The list of fields that were accessed from the bytecodes.

     */

    private ResolvedJavaField[] fields;

    private int bytecodeSize;

    private boolean hasUnsafeAccess;

    private boolean isImmutablePIC;

    public CompilationResult() {

        this(null, false);

    }

    public CompilationResult(String name) {

        this(name, false);

    }

    public CompilationResult(boolean isImmutablePIC) {

        this(null, isImmutablePIC);

    }

    public CompilationResult(String name, boolean isImmutablePIC) {

        this.name = name;

        this.isImmutablePIC = isImmutablePIC;

    }

    @Override

    public int hashCode() {

        // CompilationResult instances should not be used as hash map keys

        throw new UnsupportedOperationException("hashCode");

    }

    @Override

    public String toString() {

        if (methods != null) {

            return getClass().getName() + "[" + methods[0].format("%H.%n(%p)%r") + "]";

        }

        return identityHashCodeString(this);

    }

    @Override

    public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (obj != null && obj.getClass() == getClass()) {

            CompilationResult that = (CompilationResult) obj;

            // @formatter:off

            if (this.entryBCI == that.entryBCI &&

                Objects.equals(this.customStackArea, that.customStackArea) &&

                this.totalFrameSize == that.totalFrameSize &&

                this.targetCodeSize == that.targetCodeSize &&

                Objects.equals(this.name, that.name) &&

                Objects.equals(this.annotations, that.annotations) &&

                Objects.equals(this.dataSection, that.dataSection) &&

                Objects.equals(this.exceptionHandlers, that.exceptionHandlers) &&

                Objects.equals(this.dataPatches, that.dataPatches) &&

                Objects.equals(this.infopoints, that.infopoints) &&

                Objects.equals(this.marks,  that.marks) &&

                Arrays.equals(this.assumptions, that.assumptions) &&

                Arrays.equals(targetCode, that.targetCode)) {

                return true;

            }

            // @formatter:on

        }

        return false;

    }

    /**

     * @return the entryBCI

     */

    public int getEntryBCI() {

        return entryBCI;

    }

    /**

     * @param entryBCI the entryBCI to set

     */

    public void setEntryBCI(int entryBCI) {

        checkOpen();

        this.entryBCI = entryBCI;

    }

    /**

     * Sets the assumptions made during compilation.

     */

    public void setAssumptions(Assumption[] assumptions) {

        checkOpen();

        this.assumptions = assumptions;

    }

    /**

     * Gets the assumptions made during compilation.

     *

     * The caller must not modify the contents of the returned array.

     */

    public Assumption[] getAssumptions() {

        return assumptions;

    }

    /**

     * Sets the methods whose bytecodes were used as input to the compilation.

     *

     * @param rootMethod the root method of the compilation

     * @param inlinedMethods the methods inlined during compilation

     */

    public void setMethods(ResolvedJavaMethod rootMethod, Collection<ResolvedJavaMethod> inlinedMethods) {

        checkOpen();

        assert rootMethod != null;

        assert inlinedMethods != null;

        if (inlinedMethods.contains(rootMethod)) {

            methods = inlinedMethods.toArray(new ResolvedJavaMethod[inlinedMethods.size()]);

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

                if (methods[i].equals(rootMethod)) {

                    if (i != 0) {

                        ResolvedJavaMethod tmp = methods[0];

                        methods[0] = methods[i];

                        methods[i] = tmp;

                    }

                    break;

                }

            }

        } else {

            methods = new ResolvedJavaMethod[1 + inlinedMethods.size()];

            methods[0] = rootMethod;

            int i = 1;

            for (ResolvedJavaMethod m : inlinedMethods) {

                methods[i++] = m;

            }

        }

    }

    /**

     * Gets the methods whose bytecodes were used as input to the compilation.

     *

     * The caller must not modify the contents of the returned array.

     *

     * @return {@code null} if the compilation did not record method dependencies otherwise the

     *         methods whose bytecodes were used as input to the compilation with the first element

     *         being the root method of the compilation

     */

    public ResolvedJavaMethod[] getMethods() {

        return methods;

    }

    /**

     * Sets the fields that were referenced from the bytecodes that were used as input to the

     * compilation.

     *

     * @param accessedFields the collected set of fields accessed during compilation

     */

    public void setFields(Collection<ResolvedJavaField> accessedFields) {

        assert accessedFields != null;

        fields = accessedFields.toArray(new ResolvedJavaField[accessedFields.size()]);

    }

    /**

     * Gets the fields that were referenced from bytecodes that were used as input to the

     * compilation.

     *

     * The caller must not modify the contents of the returned array.

     *

     * @return {@code null} if the compilation did not record fields dependencies otherwise the

     *         fields that were accessed from bytecodes were used as input to the compilation.

     */

    public ResolvedJavaField[] getFields() {

        return fields;

    }

    public void setBytecodeSize(int bytecodeSize) {

        checkOpen();

        this.bytecodeSize = bytecodeSize;

    }

    public int getBytecodeSize() {

        return bytecodeSize;

    }

    public DataSection getDataSection() {

        return dataSection;

    }

    /**

     * The total frame size of the method in bytes. This includes the return address pushed onto the

     * stack, if any.

     *

     * @return the frame size

     */

    public int getTotalFrameSize() {

        assert totalFrameSize != -1 : "frame size not yet initialized!";

        return totalFrameSize;

    }

    /**

     * Sets the total frame size in bytes. This includes the return address pushed onto the stack,

     * if any.

     *

     * @param size the size of the frame in bytes

     */

    public void setTotalFrameSize(int size) {

        checkOpen();

        totalFrameSize = size;

    }

    public int getMaxInterpreterFrameSize() {

        return maxInterpreterFrameSize;

    }

    public void setMaxInterpreterFrameSize(int maxInterpreterFrameSize) {

        checkOpen();

        this.maxInterpreterFrameSize = maxInterpreterFrameSize;

    }

    public boolean isImmutablePIC() {

        return this.isImmutablePIC;

    }

    /**

     * Sets the machine that has been generated by the compiler.

     *

     * @param code the machine code generated

     * @param size the size of the machine code

     */

    public void setTargetCode(byte[] code, int size) {

        checkOpen();

        targetCode = code;

        targetCodeSize = size;

    }

    /**

     * Records a data patch in the code section. The data patch can refer to something in the

     * {@link DataSectionReference data section} or directly to an {@link ConstantReference inlined

     * constant}.

     *

     * @param codePos the position in the code that needs to be patched

     * @param ref the reference that should be inserted in the code

     */

    public void recordDataPatch(int codePos, Reference ref) {

        checkOpen();

        assert codePos >= 0 && ref != null;

        dataPatches.add(new DataPatch(codePos, ref));

    }

    /**

     * Records a data patch in the code section. The data patch can refer to something in the

     * {@link DataSectionReference data section} or directly to an {@link ConstantReference inlined

     * constant}.

     *

     * @param codePos the position in the code that needs to be patched

     * @param ref the reference that should be inserted in the code

     * @param note a note attached to data patch for use by post-processing tools

     */

    public void recordDataPatchWithNote(int codePos, Reference ref, Object note) {

        assert codePos >= 0 && ref != null;

        dataPatches.add(new DataPatch(codePos, ref, note));

    }

    /**

     * Records a call in the code array.

     *

     * @param codePos the position of the call in the code array

     * @param size the size of the call instruction

     * @param target the being called

     * @param debugInfo the debug info for the call

     * @param direct specifies if this is a {@linkplain Call#direct direct} call

     */

    public void recordCall(int codePos, int size, InvokeTarget target, DebugInfo debugInfo, boolean direct) {

        checkOpen();

        final Call call = new Call(target, codePos, size, direct, debugInfo);

        addInfopoint(call);

    }

    /**

     * Records an exception handler for this method.

     *

     * @param codePos the position in the code that is covered by the handler

     * @param handlerPos the position of the handler

     */

    public void recordExceptionHandler(int codePos, int handlerPos) {

        checkOpen();

        assert validateExceptionHandlerAdd(codePos, handlerPos) : String.format("Duplicate exception handler for pc 0x%x handlerPos 0x%x", codePos, handlerPos);

        exceptionHandlers.add(new ExceptionHandler(codePos, handlerPos));

    }

    /**

     * Validate if the exception handler for codePos already exists and handlerPos is different.

     *

     * @param codePos

     * @param handlerPos

     * @return true if the validation is successful

     */

    private boolean validateExceptionHandlerAdd(int codePos, int handlerPos) {

        ExceptionHandler exHandler = getExceptionHandlerForCodePos(codePos);

        return exHandler == null || exHandler.handlerPos == handlerPos;

    }

    /**

     * Returns the first ExceptionHandler which matches codePos.

     *

     * @param codePos position to search for

     * @return first matching ExceptionHandler

     */

    private ExceptionHandler getExceptionHandlerForCodePos(int codePos) {

        for (ExceptionHandler h : exceptionHandlers) {

            if (h.pcOffset == codePos) {

                return h;

            }

        }

        return null;

    }

    /**

     * Records an infopoint in the code array.

     *

     * @param codePos the position of the infopoint in the code array