src/main/java/org/apache/sling/scripting/sightly/java/compiler/impl/GlobalShadowChecker.java

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 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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package org.apache.sling.scripting.sightly.java.compiler.impl;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import org.apache.sling.scripting.sightly.compiler.commands.AbstractCommandVisitor;
import org.apache.sling.scripting.sightly.compiler.commands.Loop;
import org.apache.sling.scripting.sightly.compiler.commands.Procedure;
import org.apache.sling.scripting.sightly.compiler.commands.VariableBinding;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Checks whether variable declarations shadow global bindings
 */
public class GlobalShadowChecker extends AbstractCommandVisitor {

    private static final Logger log = LoggerFactory.getLogger(GlobalShadowChecker.class);
    private final Map<String, String> globals;

    public GlobalShadowChecker(Set<String> globals) {
        this.globals = new HashMap<>();
        for (String global : globals) {
            this.globals.put(global.toLowerCase(), global);
        }
    }

    @Override
    public void visit(VariableBinding.Start variableBindingStart) {
        checkVariable(variableBindingStart.getVariableName());
    }

    @Override
    public void visit(VariableBinding.Global globalAssignment) {
        checkVariable(globalAssignment.getVariableName());
    }

    @Override
    public void visit(Loop.Start loopStart) {
        checkVariable(loopStart.getItemVariable());
        checkVariable(loopStart.getIndexVariable());
        checkVariable(loopStart.getBeginVariable());
        checkVariable(loopStart.getStepVariable());
        checkVariable(loopStart.getEndVariable());
    }

    @Override
    public void visit(Procedure.Start startProcedure) {
        checkVariable(startProcedure.getName());
    }

    private void checkVariable(String variableName) {
        variableName = variableName.toLowerCase();
        if (globals.containsKey(variableName)) {
            String originalName = globals.get(variableName);
            log.warn("Global variable '{}' is being overridden in template", originalName);
        }
    }
}