hotspot/src/jdk.vm.compiler/share/classes/org.graalvm.compiler.lir/src/org/graalvm/compiler/lir/framemap/FrameMapBuilder.java

/*
 * Copyright (c) 2014, 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.
 *
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package org.graalvm.compiler.lir.framemap;

import java.util.BitSet;
import java.util.List;

import org.graalvm.compiler.lir.VirtualStackSlot;
import org.graalvm.compiler.lir.gen.LIRGenerationResult;

import jdk.vm.ci.code.CallingConvention;
import jdk.vm.ci.code.CodeCacheProvider;
import jdk.vm.ci.code.RegisterConfig;
import jdk.vm.ci.meta.ValueKind;

/**
 * A {@link FrameMapBuilder} is used to collect all information necessary to
 * {@linkplain #buildFrameMap create} a {@link FrameMap}.
 */
public abstract class FrameMapBuilder {

    /**
     * Reserves a spill slot in the frame of the method being compiled. The returned slot is aligned
     * on its natural alignment, i.e., an 8-byte spill slot is aligned at an 8-byte boundary, unless
     * overridden by a subclass.
     *
     * @param kind The kind of the spill slot to be reserved.
     * @return A spill slot denoting the reserved memory area.
     */
    public abstract VirtualStackSlot allocateSpillSlot(ValueKind<?> kind);

    /**
     * Reserves a number of contiguous slots in the frame of the method being compiled. If the
     * requested number of slots is 0, this method returns {@code null}.
     *
     * @param slots the number of slots to reserve
     * @param objects specifies the indexes of the object pointer slots. The caller is responsible
     *            for guaranteeing that each such object pointer slot is initialized before any
     *            instruction that uses a reference map. Without this guarantee, the garbage
     *            collector could see garbage object values.
     * @param outObjectStackSlots if non-null, the object pointer slots allocated are added to this
     *            list
     * @return the first reserved stack slot (i.e., at the lowest address)
     */
    public abstract VirtualStackSlot allocateStackSlots(int slots, BitSet objects, List<VirtualStackSlot> outObjectStackSlots);

    public abstract RegisterConfig getRegisterConfig();

    public abstract CodeCacheProvider getCodeCache();

    /**
     * Informs the frame map that the compiled code calls a particular method, which may need stack
     * space for outgoing arguments.
     *
     * @param cc The calling convention for the called method.
     */
    public abstract void callsMethod(CallingConvention cc);

    /**
     * Creates a {@linkplain FrameMap} based on the information collected by this
     * {@linkplain FrameMapBuilder}.
     */
    public abstract FrameMap buildFrameMap(LIRGenerationResult result);
}