/*

 * Copyright (c) 2005, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package com.sun.tools.javac.code;

import java.util.Arrays;

import java.util.EnumSet;

import java.util.Map;

import java.util.concurrent.ConcurrentHashMap;

import com.sun.tools.javac.code.Symbol.*;

import com.sun.tools.javac.main.Option;

import com.sun.tools.javac.util.Context;

import com.sun.tools.javac.util.List;

import com.sun.tools.javac.util.Options;

import com.sun.tools.javac.util.Pair;

/**

 * A class for handling -Xlint suboptions and @SuppresssWarnings.

 *

 *  <p><b>This is NOT part of any supported API.

 *  If you write code that depends on this, you do so at your own risk.

 *  This code and its internal interfaces are subject to change or

 *  deletion without notice.</b>

 */

public class Lint

{

    /** The context key for the root Lint object. */

    protected static final Context.Key<Lint> lintKey = new Context.Key<>();

    /** Get the root Lint instance. */

    public static Lint instance(Context context) {

        Lint instance = context.get(lintKey);

        if (instance == null)

            instance = new Lint(context);

        return instance;

    }

    /**

     * Returns the result of combining the values in this object with

     * the given annotation.

     */

    public Lint augment(Attribute.Compound attr) {

        return augmentor.augment(this, attr);

    }

    /**

     * Returns the result of combining the values in this object with

     * the metadata on the given symbol.

     */

    public Lint augment(Symbol sym) {

        Lint l = augmentor.augment(this, sym.getDeclarationAttributes());

        if (sym.isDeprecated()) {

            if (l == this)

                l = new Lint(this);

            l.values.remove(LintCategory.DEPRECATION);

            l.suppressedValues.add(LintCategory.DEPRECATION);

        }

        return l;

    }

    /**

     * Returns a new Lint that has the given LintCategorys suppressed.

     * @param lc one or more categories to be suppressed

     */

    public Lint suppress(LintCategory... lc) {

        Lint l = new Lint(this);

        l.values.removeAll(Arrays.asList(lc));

        l.suppressedValues.addAll(Arrays.asList(lc));

        return l;

    }

    private final AugmentVisitor augmentor;

    private final EnumSet<LintCategory> values;

    private final EnumSet<LintCategory> suppressedValues;

    private static final Map<String, LintCategory> map = new ConcurrentHashMap<>(20);

    protected Lint(Context context) {

        // initialize values according to the lint options

        Options options = Options.instance(context);

        if (options.isSet(Option.XLINT) || options.isSet(Option.XLINT_CUSTOM, "all")) {

            // If -Xlint or -Xlint:all is given, enable all categories by default

            values = EnumSet.allOf(LintCategory.class);

        } else if (options.isSet(Option.XLINT_CUSTOM, "none")) {

            // if -Xlint:none is given, disable all categories by default

            values = EnumSet.noneOf(LintCategory.class);

        } else {

            // otherwise, enable on-by-default categories

            values = EnumSet.noneOf(LintCategory.class);

            Source source = Source.instance(context);

            if (source.compareTo(Source.JDK9) >= 0) {

                values.add(LintCategory.DEP_ANN);

            }

            values.add(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC);

            values.add(LintCategory.OPENS);

            values.add(LintCategory.MODULE);

            values.add(LintCategory.REMOVAL);

        }

        // Look for specific overrides

        for (LintCategory lc : LintCategory.values()) {

            if (options.isSet(Option.XLINT_CUSTOM, lc.option)) {

                values.add(lc);

            } else if (options.isSet(Option.XLINT_CUSTOM, "-" + lc.option)) {

                values.remove(lc);

            }

        }

        suppressedValues = EnumSet.noneOf(LintCategory.class);

        context.put(lintKey, this);

        augmentor = new AugmentVisitor(context);

    }

    protected Lint(Lint other) {

        this.augmentor = other.augmentor;

        this.values = other.values.clone();

        this.suppressedValues = other.suppressedValues.clone();

    }

    @Override

    public String toString() {

        return "Lint:[values" + values + " suppressedValues" + suppressedValues + "]";

    }

    /**

     * Categories of warnings that can be generated by the compiler.

     */

    public enum LintCategory {

        /**

         * Warn when code refers to a auxiliary class that is hidden in a source file (ie source file name is

         * different from the class name, and the type is not properly nested) and the referring code

         * is not located in the same source file.

         */

        AUXILIARYCLASS("auxiliaryclass"),

        /**

         * Warn about use of unnecessary casts.

         */

        CAST("cast"),

        /**

         * Warn about issues related to classfile contents

         */

        CLASSFILE("classfile"),

        /**

         * Warn about use of deprecated items.

         */

        DEPRECATION("deprecation"),

        /**

         * Warn about items which are documented with an {@code @deprecated} JavaDoc

         * comment, but which do not have {@code @Deprecated} annotation.

         */

        DEP_ANN("dep-ann"),

        /**

         * Warn about division by constant integer 0.

         */

        DIVZERO("divzero"),

        /**

         * Warn about empty statement after if.

         */

        EMPTY("empty"),

        /**

         * Warn about issues regarding module exports.

         */

        EXPORTS("exports"),

        /**

         * Warn about falling through from one case of a switch statement to the next.

         */

        FALLTHROUGH("fallthrough"),

        /**

         * Warn about finally clauses that do not terminate normally.

         */

        FINALLY("finally"),

        /**

         * Warn about module system related issues.

         */

        MODULE("module"),

        /**

         * Warn about issues regarding module opens.

         */

        OPENS("opens"),

        /**

         * Warn about issues relating to use of command line options

         */

        OPTIONS("options"),

        /**

         * Warn about issues regarding method overloads.

         */

        OVERLOADS("overloads"),

        /**

         * Warn about issues regarding method overrides.

         */

        OVERRIDES("overrides"),

        /**

         * Warn about invalid path elements on the command line.

         * Such warnings cannot be suppressed with the SuppressWarnings

         * annotation.

         */

        PATH("path"),

        /**

         * Warn about issues regarding annotation processing.

         */

        PROCESSING("processing"),

        /**

         * Warn about unchecked operations on raw types.

         */

        RAW("rawtypes"),

        /**

         * Warn about use of deprecated-for-removal items.

         */

        REMOVAL("removal"),

        /**

         * Warn about use of automatic modules in the requires clauses.

         */

        REQUIRES_AUTOMATIC("requires-automatic"),

        /**

         * Warn about automatic modules in requires transitive.

         */

        REQUIRES_TRANSITIVE_AUTOMATIC("requires-transitive-automatic"),

        /**

         * Warn about Serializable classes that do not provide a serial version ID.

         */

        SERIAL("serial"),

        /**

         * Warn about issues relating to use of statics

         */

        STATIC("static"),

        /**

         * Warn about issues relating to use of text blocks

         */

        TEXT_BLOCKS("text-blocks"),

        /**

         * Warn about issues relating to use of try blocks (i.e. try-with-resources)

         */

        TRY("try"),

        /**

         * Warn about unchecked operations on raw types.

         */

        UNCHECKED("unchecked"),

        /**

         * Warn about potentially unsafe vararg methods

         */

        VARARGS("varargs"),

        /**

         * Warn about use of preview features.

         */

        PREVIEW("preview");

        LintCategory(String option) {

            this(option, false);

        }

        LintCategory(String option, boolean hidden) {

            this.option = option;

            this.hidden = hidden;

            map.put(option, this);

        }

        static LintCategory get(String option) {

            return map.get(option);

        }

        public final String option;

        public final boolean hidden;

    }

    /**

     * Checks if a warning category is enabled. A warning category may be enabled

     * on the command line, or by default, and can be temporarily disabled with

     * the SuppressWarnings annotation.

     */

    public boolean isEnabled(LintCategory lc) {

        return values.contains(lc);

    }

    /**

     * Checks is a warning category has been specifically suppressed, by means

     * of the SuppressWarnings annotation, or, in the case of the deprecated

     * category, whether it has been implicitly suppressed by virtue of the

     * current entity being itself deprecated.

     */

    public boolean isSuppressed(LintCategory lc) {

        return suppressedValues.contains(lc);

    }

    protected static class AugmentVisitor implements Attribute.Visitor {

        private final Context context;

        private Symtab syms;

        private Lint parent;

        private Lint lint;

        AugmentVisitor(Context context) {

            // to break an ugly sequence of initialization dependencies,

            // we defer the initialization of syms until it is needed

            this.context = context;

        }

        Lint augment(Lint parent, Attribute.Compound attr) {

            initSyms();

            this.parent = parent;

            lint = null;

            attr.accept(this);

            return (lint == null ? parent : lint);

        }

        Lint augment(Lint parent, List<Attribute.Compound> attrs) {

            initSyms();

            this.parent = parent;

            lint = null;

            for (Attribute.Compound a: attrs) {

                a.accept(this);

            }

            return (lint == null ? parent : lint);

        }

        private void initSyms() {

            if (syms == null)

                syms = Symtab.instance(context);

        }

        private void suppress(LintCategory lc) {

            if (lint == null)

                lint = new Lint(parent);

            lint.suppressedValues.add(lc);

            lint.values.remove(lc);

        }

        public void visitConstant(Attribute.Constant value) {

            if (value.type.tsym == syms.stringType.tsym) {

                LintCategory lc = LintCategory.get((String) (value.value));

                if (lc != null)

                    suppress(lc);

            }

        }

        public void visitClass(Attribute.Class clazz) {

        }

        // If we find a @SuppressWarnings annotation, then we continue

        // walking the tree, in order to suppress the individual warnings

        // specified in the @SuppressWarnings annotation.

        public void visitCompound(Attribute.Compound compound) {

            if (compound.type.tsym == syms.suppressWarningsType.tsym) {

                for (List<Pair<MethodSymbol,Attribute>> v = compound.values;

                     v.nonEmpty(); v = v.tail) {

                    Pair<MethodSymbol,Attribute> value = v.head;

                    if (value.fst.name.toString().equals("value"))

                        value.snd.accept(this);

                }

            }

        }

        public void visitArray(Attribute.Array array) {

            for (Attribute value : array.values)

                value.accept(this);

        }

        public void visitEnum(Attribute.Enum e) {

        }

        public void visitError(Attribute.Error e) {

        }

    }

}