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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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package com.sun.tools.javac.util;

import java.util.HashSet;
import java.util.Objects;
import java.util.Set;
import javax.tools.JavaFileObject;

import com.sun.tools.javac.code.Lint.LintCategory;
import com.sun.tools.javac.code.Source;
import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
import com.sun.tools.javac.util.JCDiagnostic.Note;
import com.sun.tools.javac.util.JCDiagnostic.Warning;


A handler to process mandatory warnings, setting up a deferred diagnostic
to be printed at the end of the compilation if some warnings get suppressed
because too many warnings have already been generated.
Note that the SuppressWarnings annotation can be used to suppress warnings
about conditions that would otherwise merit a warning. Such processing
is done when the condition is detected, and in those cases, no call is
made on any API to generate a warning at all. In consequence, this handler only
Returns to handle those warnings that JLS says must be generated.
 
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.
/**
 * A handler to process mandatory warnings, setting up a deferred diagnostic
 * to be printed at the end of the compilation if some warnings get suppressed
 * because too many warnings have already been generated.
 *
 * Note that the SuppressWarnings annotation can be used to suppress warnings
 * about conditions that would otherwise merit a warning. Such processing
 * is done when the condition is detected, and in those cases, no call is
 * made on any API to generate a warning at all. In consequence, this handler only
 * Returns to handle those warnings that JLS says must be generated.
 *
 *  <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 MandatoryWarningHandler {

    
The kinds of different deferred diagnostics that might be generated
if a mandatory warning is suppressed because too many warnings have
already been output.
The parameter is a fragment used to build an I18N message key for Log.
/**
     * The kinds of different deferred diagnostics that might be generated
     * if a mandatory warning is suppressed because too many warnings have
     * already been output.
     *
     * The parameter is a fragment used to build an I18N message key for Log.
     */
    private enum DeferredDiagnosticKind {
        
This kind is used when a single specific file is found to have warnings
and no similar warnings have already been given.
It generates a message like:
     FILE has ISSUES
/**
         * This kind is used when a single specific file is found to have warnings
         * and no similar warnings have already been given.
         * It generates a message like:
         *      FILE has ISSUES
         */
        IN_FILE(".filename"),
        
This kind is used when a single specific file is found to have warnings
and when similar warnings have already been reported for the file.
It generates a message like:
     FILE has additional ISSUES
/**
         * This kind is used when a single specific file is found to have warnings
         * and when similar warnings have already been reported for the file.
         * It generates a message like:
         *      FILE has additional ISSUES
         */
        ADDITIONAL_IN_FILE(".filename.additional"),
        
This kind is used when multiple files have been found to have warnings,
and none of them have had any similar warnings.
It generates a message like:
     Some files have ISSUES
/**
         * This kind is used when multiple files have been found to have warnings,
         * and none of them have had any similar warnings.
         * It generates a message like:
         *      Some files have ISSUES
         */
        IN_FILES(".plural"),
        
This kind is used when multiple files have been found to have warnings,
and some of them have had already had specific similar warnings.
It generates a message like:
     Some files have additional ISSUES
/**
         * This kind is used when multiple files have been found to have warnings,
         * and some of them have had already had specific similar warnings.
         * It generates a message like:
         *      Some files have additional ISSUES
         */
        ADDITIONAL_IN_FILES(".plural.additional");

        DeferredDiagnosticKind(String v) { value = v; }
        String getKey(String prefix) { return prefix + value; }

        private final String value;
    }


    
Create a handler for mandatory warnings.
Params:
log –     The log on which to generate any diagnostics
verbose – Specify whether or not detailed messages about
               individual instances should be given, or whether an aggregate
               message should be generated at the end of the compilation.
               Typically set via  -Xlint:option.
enforceMandatory – 
               True if mandatory warnings and notes are being enforced.
prefix –  A common prefix for the set of message keys for
               the messages that may be generated.
lc –      An associated lint category for the warnings, or null if none./**
     * Create a handler for mandatory warnings.
     * @param log     The log on which to generate any diagnostics
     * @param verbose Specify whether or not detailed messages about
     *                individual instances should be given, or whether an aggregate
     *                message should be generated at the end of the compilation.
     *                Typically set via  -Xlint:option.
     * @param enforceMandatory
     *                True if mandatory warnings and notes are being enforced.
     * @param prefix  A common prefix for the set of message keys for
     *                the messages that may be generated.
     * @param lc      An associated lint category for the warnings, or null if none.
     */
    public MandatoryWarningHandler(Log log, Source source, boolean verbose,
                                   boolean enforceMandatory, String prefix,
                                   LintCategory lc) {
        this.log = log;
        this.source = source;
        this.verbose = verbose;
        this.prefix = prefix;
        this.enforceMandatory = enforceMandatory;
        this.lintCategory = lc;
    }

    
Report a mandatory warning.
/**
     * Report a mandatory warning.
     */
    public void report(DiagnosticPosition pos, Warning warnKey) {
        JavaFileObject currentSource = log.currentSourceFile();

        if (verbose) {
            if (sourcesWithReportedWarnings == null)
                sourcesWithReportedWarnings = new HashSet<>();

            if (log.nwarnings < log.MaxWarnings) {
                // generate message and remember the source file
                logMandatoryWarning(pos, warnKey);
                sourcesWithReportedWarnings.add(currentSource);
            } else if (deferredDiagnosticKind == null) {
                // set up deferred message
                if (sourcesWithReportedWarnings.contains(currentSource)) {
                    // more errors in a file that already has reported warnings
                    deferredDiagnosticKind = DeferredDiagnosticKind.ADDITIONAL_IN_FILE;
                } else {
                    // warnings in a new source file
                    deferredDiagnosticKind = DeferredDiagnosticKind.IN_FILE;
                }
                deferredDiagnosticSource = currentSource;
                deferredDiagnosticArg = currentSource;
            } else if ((deferredDiagnosticKind == DeferredDiagnosticKind.IN_FILE
                        || deferredDiagnosticKind == DeferredDiagnosticKind.ADDITIONAL_IN_FILE)
                       && !Objects.equals(deferredDiagnosticSource, currentSource)) {
                // additional errors in more than one source file
                deferredDiagnosticKind = DeferredDiagnosticKind.ADDITIONAL_IN_FILES;
                deferredDiagnosticArg = null;
            }
        } else {
            if (deferredDiagnosticKind == null) {
                // warnings in a single source
                deferredDiagnosticKind = DeferredDiagnosticKind.IN_FILE;
                deferredDiagnosticSource = currentSource;
                deferredDiagnosticArg = currentSource;
            }  else if (deferredDiagnosticKind == DeferredDiagnosticKind.IN_FILE &&
                        !Objects.equals(deferredDiagnosticSource, currentSource)) {
                // warnings in multiple source files
                deferredDiagnosticKind = DeferredDiagnosticKind.IN_FILES;
                deferredDiagnosticArg = null;
            }
        }
    }

    
Report any diagnostic that might have been deferred by previous calls of report().
/**
     * Report any diagnostic that might have been deferred by previous calls of report().
     */
    public void reportDeferredDiagnostic() {
        if (deferredDiagnosticKind != null) {
            if (deferredDiagnosticArg == null) {
                if (source != null) {
                    logMandatoryNote(deferredDiagnosticSource, deferredDiagnosticKind.getKey(prefix), source);
                } else {
                    logMandatoryNote(deferredDiagnosticSource, deferredDiagnosticKind.getKey(prefix));
                }
            } else {
                if (source != null) {
                    logMandatoryNote(deferredDiagnosticSource, deferredDiagnosticKind.getKey(prefix), deferredDiagnosticArg, source);
                } else {
                    logMandatoryNote(deferredDiagnosticSource, deferredDiagnosticKind.getKey(prefix), deferredDiagnosticArg);
                }
            }

            if (!verbose)
                logMandatoryNote(deferredDiagnosticSource, prefix + ".recompile");
        }
    }

    
The log to which to report warnings.
/**
     * The log to which to report warnings.
     */
    private final Log log;
    private final Source source;

    
Whether or not to report individual warnings, or simply to report a
single aggregate warning at the end of the compilation.
/**
     * Whether or not to report individual warnings, or simply to report a
     * single aggregate warning at the end of the compilation.
     */
    private final boolean verbose;

    
The common prefix for all I18N message keys generated by this handler.
/**
     * The common prefix for all I18N message keys generated by this handler.
     */
    private final String prefix;

    
A set containing the names of the source files for which specific
warnings have been generated -- i.e. in verbose mode.  If a source name
appears in this list, then deferred diagnostics will be phrased to
include "additionally"...
/**
     * A set containing the names of the source files for which specific
     * warnings have been generated -- i.e. in verbose mode.  If a source name
     * appears in this list, then deferred diagnostics will be phrased to
     * include "additionally"...
     */
    private Set<JavaFileObject> sourcesWithReportedWarnings;

    
A variable indicating the latest best guess at what the final
deferred diagnostic will be. Initially as specific and helpful
as possible, as more warnings are reported, the scope of the
diagnostic will be broadened.
/**
     * A variable indicating the latest best guess at what the final
     * deferred diagnostic will be. Initially as specific and helpful
     * as possible, as more warnings are reported, the scope of the
     * diagnostic will be broadened.
     */
    private DeferredDiagnosticKind deferredDiagnosticKind;

    
If deferredDiagnosticKind is IN_FILE or ADDITIONAL_IN_FILE, this variable
gives the value of log.currentSource() for the file in question.
/**
     * If deferredDiagnosticKind is IN_FILE or ADDITIONAL_IN_FILE, this variable
     * gives the value of log.currentSource() for the file in question.
     */
    private JavaFileObject deferredDiagnosticSource;

    
An optional argument to be used when constructing the
deferred diagnostic message, based on deferredDiagnosticKind.
This variable should normally be set/updated whenever
deferredDiagnosticKind is updated.
/**
     * An optional argument to be used when constructing the
     * deferred diagnostic message, based on deferredDiagnosticKind.
     * This variable should normally be set/updated whenever
     * deferredDiagnosticKind is updated.
     */
    private Object deferredDiagnosticArg;

    
True if mandatory warnings and notes are being enforced.
/**
     * True if mandatory warnings and notes are being enforced.
     */
    private final boolean enforceMandatory;

    
A LintCategory to be included in point-of-use diagnostics to indicate
how messages might be suppressed (i.e. with @SuppressWarnings).
/**
     * A LintCategory to be included in point-of-use diagnostics to indicate
     * how messages might be suppressed (i.e. with @SuppressWarnings).
     */
    private final LintCategory lintCategory;

    
Reports a mandatory warning to the log.  If mandatory warnings
are not being enforced, treat this as an ordinary warning.
/**
     * Reports a mandatory warning to the log.  If mandatory warnings
     * are not being enforced, treat this as an ordinary warning.
     */
    private void logMandatoryWarning(DiagnosticPosition pos, Warning warnKey) {
        // Note: the following log methods are safe if lintCategory is null.
        if (enforceMandatory)
            log.mandatoryWarning(lintCategory, pos, warnKey);
        else
            log.warning(lintCategory, pos, warnKey);
    }

    
Reports a mandatory note to the log.  If mandatory notes are
not being enforced, treat this as an ordinary note.
/**
     * Reports a mandatory note to the log.  If mandatory notes are
     * not being enforced, treat this as an ordinary note.
     */
    private void logMandatoryNote(JavaFileObject file, String msg, Object... args) {
        if (enforceMandatory)
            log.mandatoryNote(file, new Note("compiler", msg, args));
        else
            log.note(file, new Note("compiler", msg, args));
    }

    public void clear() {
        sourcesWithReportedWarnings = null;
        deferredDiagnosticKind = null;
        deferredDiagnosticSource = null;
        deferredDiagnosticArg = null;
    }
}