/*

 * 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 static org.graalvm.compiler.hotspot.HotSpotForeignCallLinkage.RegisterEffect.DESTROYS_REGISTERS;

import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;

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

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

import org.graalvm.compiler.core.target.Backend;

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

import org.graalvm.compiler.hotspot.stubs.Stub;

import org.graalvm.compiler.word.WordTypes;

import jdk.vm.ci.code.CallingConvention;

import jdk.vm.ci.code.CallingConvention.Type;

import jdk.vm.ci.code.CodeCacheProvider;

import jdk.vm.ci.code.InstalledCode;

import jdk.vm.ci.code.Register;

import jdk.vm.ci.code.RegisterConfig;

import jdk.vm.ci.code.ValueKindFactory;

import jdk.vm.ci.hotspot.HotSpotCallingConventionType;

import jdk.vm.ci.hotspot.HotSpotForeignCallTarget;

import jdk.vm.ci.meta.AllocatableValue;

import jdk.vm.ci.meta.JavaType;

import jdk.vm.ci.meta.MetaAccessProvider;

import jdk.vm.ci.meta.ResolvedJavaType;

import jdk.vm.ci.meta.Value;

/**

 * The details required to link a HotSpot runtime or stub call.

 */

public class HotSpotForeignCallLinkageImpl extends HotSpotForeignCallTarget implements HotSpotForeignCallLinkage {

    /**

     * The descriptor of the call.

     */

    protected final ForeignCallDescriptor descriptor;

    /**

     * Non-null (eventually) iff this is a call to a compiled {@linkplain Stub stub}.

     */

    private Stub stub;

    /**

     * The calling convention for this call.

     */

    private final CallingConvention outgoingCallingConvention;

    /**

     * The calling convention for incoming arguments to the stub, iff this call uses a compiled

     * {@linkplain Stub stub}.

     */

    private final CallingConvention incomingCallingConvention;

    private final RegisterEffect effect;

    private final Transition transition;

    /**

     * The registers and stack slots defined/killed by the call.

     */

    private Value[] temporaries = AllocatableValue.NONE;

    /**

     * The memory locations killed by the call.

     */

    private final LocationIdentity[] killedLocations;

    private final boolean reexecutable;

    /**

     * Creates a {@link HotSpotForeignCallLinkage}.

     *

     * @param descriptor the descriptor of the call

     * @param address the address of the code to call

     * @param effect specifies if the call destroys or preserves all registers (apart from

     *            temporaries which are always destroyed)

     * @param outgoingCcType outgoing (caller) calling convention type

     * @param incomingCcType incoming (callee) calling convention type (can be null)

     * @param transition specifies if this is a {@linkplain #needsDebugInfo() leaf} call

     * @param reexecutable specifies if the call can be re-executed without (meaningful) side

     *            effects. Deoptimization will not return to a point before a call that cannot be

     *            re-executed.

     * @param killedLocations the memory locations killed by the call

     */

    public static HotSpotForeignCallLinkage create(MetaAccessProvider metaAccess, CodeCacheProvider codeCache, WordTypes wordTypes, HotSpotForeignCallsProvider foreignCalls,

                    ForeignCallDescriptor descriptor, long address, RegisterEffect effect, Type outgoingCcType, Type incomingCcType, Transition transition, boolean reexecutable,

                    LocationIdentity... killedLocations) {

        CallingConvention outgoingCc = createCallingConvention(metaAccess, codeCache, wordTypes, foreignCalls, descriptor, outgoingCcType);

        CallingConvention incomingCc = incomingCcType == null ? null : createCallingConvention(metaAccess, codeCache, wordTypes, foreignCalls, descriptor, incomingCcType);

        HotSpotForeignCallLinkageImpl linkage = new HotSpotForeignCallLinkageImpl(descriptor, address, effect, transition, outgoingCc, incomingCc, reexecutable, killedLocations);

        if (outgoingCcType == HotSpotCallingConventionType.NativeCall) {

            linkage.temporaries = foreignCalls.getNativeABICallerSaveRegisters();

        }

        return linkage;

    }

    /**

     * Gets a calling convention for a given descriptor and call type.

     */

    public static CallingConvention createCallingConvention(MetaAccessProvider metaAccess, CodeCacheProvider codeCache, WordTypes wordTypes, ValueKindFactory<?> valueKindFactory,

                    ForeignCallDescriptor descriptor, Type ccType) {

        assert ccType != null;

        Class<?>[] argumentTypes = descriptor.getArgumentTypes();

        JavaType[] parameterTypes = new JavaType[argumentTypes.length];

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

            parameterTypes[i] = asJavaType(argumentTypes[i], metaAccess, wordTypes);

        }

        JavaType returnType = asJavaType(descriptor.getResultType(), metaAccess, wordTypes);

        RegisterConfig regConfig = codeCache.getRegisterConfig();

        return regConfig.getCallingConvention(ccType, returnType, parameterTypes, valueKindFactory);

    }

    private static JavaType asJavaType(Class<?> type, MetaAccessProvider metaAccess, WordTypes wordTypes) {

        ResolvedJavaType javaType = metaAccess.lookupJavaType(type);

        if (wordTypes.isWord(javaType)) {

            javaType = metaAccess.lookupJavaType(wordTypes.getWordKind().toJavaClass());

        }

        return javaType;

    }

    public HotSpotForeignCallLinkageImpl(ForeignCallDescriptor descriptor, long address, RegisterEffect effect, Transition transition, CallingConvention outgoingCallingConvention,

                    CallingConvention incomingCallingConvention, boolean reexecutable, LocationIdentity... killedLocations) {

        super(address);

        this.descriptor = descriptor;

        this.address = address;

        this.effect = effect;

        this.transition = transition;

        assert outgoingCallingConvention != null : "only incomingCallingConvention can be null";

        this.outgoingCallingConvention = outgoingCallingConvention;

        this.incomingCallingConvention = incomingCallingConvention != null ? incomingCallingConvention : outgoingCallingConvention;

        this.reexecutable = reexecutable;

        this.killedLocations = killedLocations;

    }

    @Override

    public String toString() {

        StringBuilder sb = new StringBuilder(stub == null ? descriptor.toString() : stub.toString());

        sb.append("@0x").append(Long.toHexString(address)).append(':').append(outgoingCallingConvention).append(":").append(incomingCallingConvention);

        if (temporaries != null && temporaries.length != 0) {

            sb.append("; temps=");

            String sep = "";

            for (Value op : temporaries) {

                sb.append(sep).append(op);

                sep = ",";

            }

        }

        return sb.toString();

    }

    @Override

    public boolean isReexecutable() {

        return reexecutable;

    }

    @Override

    public boolean isGuaranteedSafepoint() {

        return transition == Transition.SAFEPOINT;

    }

    @Override

    public LocationIdentity[] getKilledLocations() {

        return killedLocations;

    }

    @Override

    public CallingConvention getOutgoingCallingConvention() {

        return outgoingCallingConvention;

    }

    @Override

    public CallingConvention getIncomingCallingConvention() {

        return incomingCallingConvention;

    }

    @Override

    public Value[] getTemporaries() {

        if (temporaries.length == 0) {

            return temporaries;

        }

        return temporaries.clone();

    }

    @Override

    public long getMaxCallTargetOffset() {

        return runtime().getHostJVMCIBackend().getCodeCache().getMaxCallTargetOffset(address);

    }

    @Override

    public ForeignCallDescriptor getDescriptor() {

        return descriptor;

    }

    @Override

    public void setCompiledStub(Stub stub) {

        assert address == 0L : "cannot set stub for linkage that already has an address: " + this;

        this.stub = stub;

    }

    /**

     * Determines if this is a call to a compiled {@linkplain Stub stub}.

     */

    @Override

    public boolean isCompiledStub() {

        return address == 0L || stub != null;

    }

    @Override

    public void finalizeAddress(Backend backend) {

        if (address == 0) {

            InstalledCode code = stub.getCode(backend);

            if (!destroyedRegisters.isEmpty()) {

                AllocatableValue[] temporaryLocations = new AllocatableValue[destroyedRegisters.size()];

                int i = 0;

                for (Register reg : destroyedRegisters) {

                    temporaryLocations[i++] = reg.asValue();

                }

                temporaries = temporaryLocations;

            }

            address = code.getStart();

        }

    }

    @Override

    public long getAddress() {

        assert address != 0L : "address not yet finalized: " + this;

        return address;

    }

    @Override

    public boolean destroysRegisters() {

        return effect == DESTROYS_REGISTERS;

    }

    @Override

    public boolean needsDebugInfo() {

        return transition == Transition.SAFEPOINT;

    }

    @Override

    public boolean mayContainFP() {

        return transition != Transition.LEAF_NOFP;

    }

    @Override

    public boolean needsJavaFrameAnchor() {

        if (transition == Transition.SAFEPOINT || transition == Transition.STACK_INSPECTABLE_LEAF) {

            if (stub != null) {

                // The stub will do the JavaFrameAnchor management

                // around the runtime call(s) it makes

                return false;

            } else {

                return true;

            }

        }

        return false;

    }

    @Override

    public String getSymbol() {

        return stub == null ? null : stub.toString();

    }

}