/*
 * Copyright (c) 2017, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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
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package com.oracle.svm.polyglot.scala;

import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderContext;
import org.graalvm.compiler.nodes.graphbuilderconf.NodePlugin;

import com.oracle.graal.pointsto.meta.AnalysisType;

import jdk.vm.ci.meta.JavaConstant;
import jdk.vm.ci.meta.ResolvedJavaMethod;

Registers array classes for reflective instantiation.
Scala uses ClassTags to reflectively instantiate arrays. This plugin tracks creations of class
tags and marks types as in heap.
/**
 * Registers array classes for reflective instantiation.
 *
 * Scala uses ClassTags to reflectively instantiate arrays. This plugin tracks creations of class
 * tags and marks types as in heap.
 */
public final class ScalaAnalysisPlugin implements NodePlugin {

    
Should be high enough to never be encountered in practice and low enough so types do not take
much space in the native image heap. Current number is chosen as ClassTag has methods for
instantiating arrays up to 5 levels of nesting, and we want to support them.
/**
     * Should be high enough to never be encountered in practice and low enough so types do not take
     * much space in the native image heap. Current number is chosen as ClassTag has methods for
     * instantiating arrays up to 5 levels of nesting, and we want to support them.
     */
    private static final int SUPPORTED_LEVEL_OF_NESTED_ARRAYS = 5;

    @Override
    public boolean handleInvoke(GraphBuilderContext b, ResolvedJavaMethod method, ValueNode[] args) {
        /* ClassTag(<type>.class) */
        if (method.getDeclaringClass().getName().equals("Lscala/reflect/ClassTag$;") && method.getName().equals("apply") && args.length == 2) {
            JavaConstant clazzConstant = args[1].asJavaConstant();
            if (clazzConstant != null) {
                AnalysisType type = (AnalysisType) b.getConstantReflection().asJavaType(clazzConstant);
                for (int i = 0; i < SUPPORTED_LEVEL_OF_NESTED_ARRAYS; i++) {
                    type = type.getArrayClass();
                    type.registerAsInHeap();
                }
            }
        }
        return false;
    }
}