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 * 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.hotspot.replacements;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_UNKNOWN;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_20;

import org.graalvm.compiler.core.common.type.StampPair;
import org.graalvm.compiler.debug.GraalError;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.graph.spi.Canonicalizable;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.CallTargetNode.InvokeKind;
import org.graalvm.compiler.nodes.ConstantNode;
import org.graalvm.compiler.nodes.FrameState;
import org.graalvm.compiler.nodes.InvokeNode;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.spi.Lowerable;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.replacements.nodes.MacroStateSplitNode;

import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;
import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;
import jdk.vm.ci.meta.ConstantReflectionProvider;
import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.ResolvedJavaMethod;

@NodeInfo(cycles = CYCLES_UNKNOWN, cyclesRationale = "This node can be lowered to a call", size = SIZE_20)
public final class ReflectionGetCallerClassNode extends MacroStateSplitNode implements Canonicalizable, Lowerable {

    public static final NodeClass<ReflectionGetCallerClassNode> TYPE = NodeClass.create(ReflectionGetCallerClassNode.class);

    public ReflectionGetCallerClassNode(InvokeKind invokeKind, ResolvedJavaMethod targetMethod, int bci, StampPair returnStamp, ValueNode... arguments) {
        super(TYPE, invokeKind, targetMethod, bci, returnStamp, arguments);
    }

    @Override
    public Node canonical(CanonicalizerTool tool) {
        ConstantNode callerClassNode = getCallerClassNode(tool.getMetaAccess(), tool.getConstantReflection());
        if (callerClassNode != null) {
            return callerClassNode;
        }
        return this;
    }

    @Override
    public void lower(LoweringTool tool) {
        ConstantNode callerClassNode = getCallerClassNode(tool.getMetaAccess(), tool.getConstantReflection());

        if (callerClassNode != null) {
            graph().replaceFixedWithFloating(this, graph().addOrUniqueWithInputs(callerClassNode));
        } else {
            InvokeNode invoke = createInvoke();
            graph().replaceFixedWithFixed(this, invoke);
            invoke.lower(tool);
        }
    }

    
If inlining is deep enough this method returns a ConstantNode of the caller class by walking the the stack.
Params:
  • metaAccess –
Returns:ConstantNode of the caller class, or null
/** * If inlining is deep enough this method returns a {@link ConstantNode} of the caller class by * walking the the stack. * * @param metaAccess * @return ConstantNode of the caller class, or null */
private ConstantNode getCallerClassNode(MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) { // Walk back up the frame states to find the caller at the required depth. FrameState state = stateAfter(); // Cf. JVM_GetCallerClass // NOTE: Start the loop at depth 1 because the current frame state does // not include the Reflection.getCallerClass() frame. for (int n = 1; state != null; state = state.outerFrameState(), n++) { HotSpotResolvedJavaMethod method = (HotSpotResolvedJavaMethod) state.getMethod(); switch (n) { case 0: throw GraalError.shouldNotReachHere("current frame state does not include the Reflection.getCallerClass frame"); case 1: // Frame 0 and 1 must be caller sensitive (see JVM_GetCallerClass). if (!method.isCallerSensitive()) { return null; // bail-out; let JVM_GetCallerClass do the work } break; default: if (!method.ignoredBySecurityStackWalk()) { // We have reached the desired frame; return the holder class. HotSpotResolvedObjectType callerClass = method.getDeclaringClass(); return ConstantNode.forConstant(constantReflection.asJavaClass(callerClass), metaAccess); } break; } } return null; // bail-out; let JVM_GetCallerClass do the work } }