Checker.java revision 3896:8e4dbcb99277 
1/*
2 * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package com.sun.tools.doclint;
27
28import java.io.IOException;
29import java.io.StringWriter;
30import java.net.URI;
31import java.net.URISyntaxException;
32import java.util.Deque;
33import java.util.EnumSet;
34import java.util.HashMap;
35import java.util.HashSet;
36import java.util.LinkedList;
37import java.util.List;
38import java.util.Map;
39import java.util.Set;
40import java.util.regex.Matcher;
41import java.util.regex.Pattern;
42
43import javax.lang.model.element.Element;
44import javax.lang.model.element.ElementKind;
45import javax.lang.model.element.ExecutableElement;
46import javax.lang.model.element.Name;
47import javax.lang.model.element.VariableElement;
48import javax.lang.model.type.TypeKind;
49import javax.lang.model.type.TypeMirror;
50import javax.tools.Diagnostic.Kind;
51import javax.tools.JavaFileObject;
52
53import com.sun.source.doctree.AttributeTree;
54import com.sun.source.doctree.AuthorTree;
55import com.sun.source.doctree.DocCommentTree;
56import com.sun.source.doctree.DocRootTree;
57import com.sun.source.doctree.DocTree;
58import com.sun.source.doctree.EndElementTree;
59import com.sun.source.doctree.EntityTree;
60import com.sun.source.doctree.ErroneousTree;
61import com.sun.source.doctree.IdentifierTree;
62import com.sun.source.doctree.InheritDocTree;
63import com.sun.source.doctree.LinkTree;
64import com.sun.source.doctree.LiteralTree;
65import com.sun.source.doctree.ParamTree;
66import com.sun.source.doctree.ProvidesTree;
67import com.sun.source.doctree.ReferenceTree;
68import com.sun.source.doctree.ReturnTree;
69import com.sun.source.doctree.SerialDataTree;
70import com.sun.source.doctree.SerialFieldTree;
71import com.sun.source.doctree.SinceTree;
72import com.sun.source.doctree.StartElementTree;
73import com.sun.source.doctree.TextTree;
74import com.sun.source.doctree.ThrowsTree;
75import com.sun.source.doctree.UnknownBlockTagTree;
76import com.sun.source.doctree.UnknownInlineTagTree;
77import com.sun.source.doctree.UsesTree;
78import com.sun.source.doctree.ValueTree;
79import com.sun.source.doctree.VersionTree;
80import com.sun.source.tree.Tree;
81import com.sun.source.util.DocTreePath;
82import com.sun.source.util.DocTreePathScanner;
83import com.sun.source.util.TreePath;
84import com.sun.tools.doclint.HtmlTag.AttrKind;
85import com.sun.tools.javac.tree.DocPretty;
86import com.sun.tools.javac.util.Assert;
87import com.sun.tools.javac.util.DefinedBy;
88import com.sun.tools.javac.util.DefinedBy.Api;
89import com.sun.tools.javac.util.StringUtils;
90
91import static com.sun.tools.doclint.Messages.Group.*;
92
93
94/**
95 * Validate a doc comment.
96 *
97 * <p><b>This is NOT part of any supported API.
98 * If you write code that depends on this, you do so at your own
99 * risk.  This code and its internal interfaces are subject to change
100 * or deletion without notice.</b></p>
101 */
102public class Checker extends DocTreePathScanner<Void, Void> {
103    final Env env;
104
105    Set<Element> foundParams = new HashSet<>();
106    Set<TypeMirror> foundThrows = new HashSet<>();
107    Map<Element, Set<String>> foundAnchors = new HashMap<>();
108    boolean foundInheritDoc = false;
109    boolean foundReturn = false;
110
111    public enum Flag {
112        TABLE_HAS_CAPTION,
113        HAS_ELEMENT,
114        HAS_HEADING,
115        HAS_INLINE_TAG,
116        HAS_TEXT,
117        REPORTED_BAD_INLINE
118    }
119
120    static class TagStackItem {
121        final DocTree tree; // typically, but not always, StartElementTree
122        final HtmlTag tag;
123        final Set<HtmlTag.Attr> attrs;
124        final Set<Flag> flags;
125        TagStackItem(DocTree tree, HtmlTag tag) {
126            this.tree = tree;
127            this.tag = tag;
128            attrs = EnumSet.noneOf(HtmlTag.Attr.class);
129            flags = EnumSet.noneOf(Flag.class);
130        }
131        @Override
132        public String toString() {
133            return String.valueOf(tag);
134        }
135    }
136
137    private final Deque<TagStackItem> tagStack; // TODO: maybe want to record starting tree as well
138    private HtmlTag currHeaderTag;
139
140    private final int implicitHeaderLevel;
141
142    // <editor-fold defaultstate="collapsed" desc="Top level">
143
144    Checker(Env env) {
145        this.env = Assert.checkNonNull(env);
146        tagStack = new LinkedList<>();
147        implicitHeaderLevel = env.implicitHeaderLevel;
148    }
149
150    public Void scan(DocCommentTree tree, TreePath p) {
151        env.initTypes();
152        env.setCurrent(p, tree);
153
154        boolean isOverridingMethod = !env.currOverriddenMethods.isEmpty();
155        JavaFileObject fo = p.getCompilationUnit().getSourceFile();
156
157        if (p.getLeaf().getKind() == Tree.Kind.PACKAGE) {
158            // If p points to a package, the implied declaration is the
159            // package declaration (if any) for the compilation unit.
160            // Handle this case specially, because doc comments are only
161            // expected in package-info files.
162            boolean isPkgInfo = fo.isNameCompatible("package-info", JavaFileObject.Kind.SOURCE);
163            if (tree == null) {
164                if (isPkgInfo)
165                    reportMissing("dc.missing.comment");
166                return null;
167            } else {
168                if (!isPkgInfo)
169                    reportReference("dc.unexpected.comment");
170            }
171        } else if (tree != null && fo.isNameCompatible("package", JavaFileObject.Kind.HTML)) {
172            // a package.html file with a DocCommentTree
173            if (tree.getFullBody().isEmpty()) {
174                reportMissing("dc.missing.comment");
175                return null;
176            }
177        } else {
178            if (tree == null) {
179                if (!isSynthetic() && !isOverridingMethod)
180                    reportMissing("dc.missing.comment");
181                return null;
182            }
183        }
184
185        tagStack.clear();
186        currHeaderTag = null;
187
188        foundParams.clear();
189        foundThrows.clear();
190        foundInheritDoc = false;
191        foundReturn = false;
192
193        scan(new DocTreePath(p, tree), null);
194
195        if (!isOverridingMethod) {
196            switch (env.currElement.getKind()) {
197                case METHOD:
198                case CONSTRUCTOR: {
199                    ExecutableElement ee = (ExecutableElement) env.currElement;
200                    checkParamsDocumented(ee.getTypeParameters());
201                    checkParamsDocumented(ee.getParameters());
202                    switch (ee.getReturnType().getKind()) {
203                        case VOID:
204                        case NONE:
205                            break;
206                        default:
207                            if (!foundReturn
208                                    && !foundInheritDoc
209                                    && !env.types.isSameType(ee.getReturnType(), env.java_lang_Void)) {
210                                reportMissing("dc.missing.return");
211                            }
212                    }
213                    checkThrowsDocumented(ee.getThrownTypes());
214                }
215            }
216        }
217
218        return null;
219    }
220
221    private void reportMissing(String code, Object... args) {
222        env.messages.report(MISSING, Kind.WARNING, env.currPath.getLeaf(), code, args);
223    }
224
225    private void reportReference(String code, Object... args) {
226        env.messages.report(REFERENCE, Kind.WARNING, env.currPath.getLeaf(), code, args);
227    }
228
229    @Override @DefinedBy(Api.COMPILER_TREE)
230    public Void visitDocComment(DocCommentTree tree, Void ignore) {
231        super.visitDocComment(tree, ignore);
232        for (TagStackItem tsi: tagStack) {
233            warnIfEmpty(tsi, null);
234            if (tsi.tree.getKind() == DocTree.Kind.START_ELEMENT
235                    && tsi.tag.endKind == HtmlTag.EndKind.REQUIRED) {
236                StartElementTree t = (StartElementTree) tsi.tree;
237                env.messages.error(HTML, t, "dc.tag.not.closed", t.getName());
238            }
239        }
240        return null;
241    }
242    // </editor-fold>
243
244    // <editor-fold defaultstate="collapsed" desc="Text and entities.">
245
246    @Override @DefinedBy(Api.COMPILER_TREE)
247    public Void visitText(TextTree tree, Void ignore) {
248        if (hasNonWhitespace(tree)) {
249            checkAllowsText(tree);
250            markEnclosingTag(Flag.HAS_TEXT);
251        }
252        return null;
253    }
254
255    @Override @DefinedBy(Api.COMPILER_TREE)
256    public Void visitEntity(EntityTree tree, Void ignore) {
257        checkAllowsText(tree);
258        markEnclosingTag(Flag.HAS_TEXT);
259        String name = tree.getName().toString();
260        if (name.startsWith("#")) {
261            int v = StringUtils.toLowerCase(name).startsWith("#x")
262                    ? Integer.parseInt(name.substring(2), 16)
263                    : Integer.parseInt(name.substring(1), 10);
264            if (!Entity.isValid(v)) {
265                env.messages.error(HTML, tree, "dc.entity.invalid", name);
266            }
267        } else if (!Entity.isValid(name)) {
268            env.messages.error(HTML, tree, "dc.entity.invalid", name);
269        }
270        return null;
271    }
272
273    void checkAllowsText(DocTree tree) {
274        TagStackItem top = tagStack.peek();
275        if (top != null
276                && top.tree.getKind() == DocTree.Kind.START_ELEMENT
277                && !top.tag.acceptsText()) {
278            if (top.flags.add(Flag.REPORTED_BAD_INLINE)) {
279                env.messages.error(HTML, tree, "dc.text.not.allowed",
280                        ((StartElementTree) top.tree).getName());
281            }
282        }
283    }
284
285    // </editor-fold>
286
287    // <editor-fold defaultstate="collapsed" desc="HTML elements">
288
289    @Override @DefinedBy(Api.COMPILER_TREE)
290    public Void visitStartElement(StartElementTree tree, Void ignore) {
291        final Name treeName = tree.getName();
292        final HtmlTag t = HtmlTag.get(treeName);
293        if (t == null) {
294            env.messages.error(HTML, tree, "dc.tag.unknown", treeName);
295        } else if (t.allowedVersion != HtmlVersion.ALL && t.allowedVersion != env.htmlVersion) {
296            env.messages.error(HTML, tree, "dc.tag.not.supported", treeName);
297        } else {
298            boolean done = false;
299            for (TagStackItem tsi: tagStack) {
300                if (tsi.tag.accepts(t)) {
301                    while (tagStack.peek() != tsi) {
302                        warnIfEmpty(tagStack.peek(), null);
303                        tagStack.pop();
304                    }
305                    done = true;
306                    break;
307                } else if (tsi.tag.endKind != HtmlTag.EndKind.OPTIONAL) {
308                    done = true;
309                    break;
310                }
311            }
312            if (!done && HtmlTag.BODY.accepts(t)) {
313                while (!tagStack.isEmpty()) {
314                    warnIfEmpty(tagStack.peek(), null);
315                    tagStack.pop();
316                }
317            }
318
319            markEnclosingTag(Flag.HAS_ELEMENT);
320            checkStructure(tree, t);
321
322            // tag specific checks
323            switch (t) {
324                // check for out of sequence headers, such as <h1>...</h1>  <h3>...</h3>
325                case H1: case H2: case H3: case H4: case H5: case H6:
326                    checkHeader(tree, t);
327                    break;
328            }
329
330            if (t.flags.contains(HtmlTag.Flag.NO_NEST)) {
331                for (TagStackItem i: tagStack) {
332                    if (t == i.tag) {
333                        env.messages.warning(HTML, tree, "dc.tag.nested.not.allowed", treeName);
334                        break;
335                    }
336                }
337            }
338        }
339
340        // check for self closing tags, such as <a id="name"/>
341        if (tree.isSelfClosing()) {
342            env.messages.error(HTML, tree, "dc.tag.self.closing", treeName);
343        }
344
345        try {
346            TagStackItem parent = tagStack.peek();
347            TagStackItem top = new TagStackItem(tree, t);
348            tagStack.push(top);
349
350            super.visitStartElement(tree, ignore);
351
352            // handle attributes that may or may not have been found in start element
353            if (t != null) {
354                switch (t) {
355                    case CAPTION:
356                        if (parent != null && parent.tag == HtmlTag.TABLE)
357                            parent.flags.add(Flag.TABLE_HAS_CAPTION);
358                        break;
359
360                    case H1: case H2: case H3: case H4: case H5: case H6:
361                        if (parent != null && (parent.tag == HtmlTag.SECTION || parent.tag == HtmlTag.ARTICLE)) {
362                            parent.flags.add(Flag.HAS_HEADING);
363                        }
364                        break;
365
366                    case IMG:
367                        if (!top.attrs.contains(HtmlTag.Attr.ALT))
368                            env.messages.error(ACCESSIBILITY, tree, "dc.no.alt.attr.for.image");
369                        break;
370                }
371            }
372
373            return null;
374        } finally {
375
376            if (t == null || t.endKind == HtmlTag.EndKind.NONE)
377                tagStack.pop();
378        }
379    }
380
381    private void checkStructure(StartElementTree tree, HtmlTag t) {
382        Name treeName = tree.getName();
383        TagStackItem top = tagStack.peek();
384        switch (t.blockType) {
385            case BLOCK:
386                if (top == null || top.tag.accepts(t))
387                    return;
388
389                switch (top.tree.getKind()) {
390                    case START_ELEMENT: {
391                        if (top.tag.blockType == HtmlTag.BlockType.INLINE) {
392                            Name name = ((StartElementTree) top.tree).getName();
393                            env.messages.error(HTML, tree, "dc.tag.not.allowed.inline.element",
394                                    treeName, name);
395                            return;
396                        }
397                    }
398                    break;
399
400                    case LINK:
401                    case LINK_PLAIN: {
402                        String name = top.tree.getKind().tagName;
403                        env.messages.error(HTML, tree, "dc.tag.not.allowed.inline.tag",
404                                treeName, name);
405                        return;
406                    }
407                }
408                break;
409
410            case INLINE:
411                if (top == null || top.tag.accepts(t))
412                    return;
413                break;
414
415            case LIST_ITEM:
416            case TABLE_ITEM:
417                if (top != null) {
418                    // reset this flag so subsequent bad inline content gets reported
419                    top.flags.remove(Flag.REPORTED_BAD_INLINE);
420                    if (top.tag.accepts(t))
421                        return;
422                }
423                break;
424
425            case OTHER:
426                switch (t) {
427                    case SCRIPT:
428                        // <script> may or may not be allowed, depending on --allow-script-in-comments
429                        // but we allow it here, and rely on a separate scanner to detect all uses
430                        // of JavaScript, including <script> tags, and use in attributes, etc.
431                        break;
432
433                    default:
434                        env.messages.error(HTML, tree, "dc.tag.not.allowed", treeName);
435                }
436                return;
437        }
438
439        env.messages.error(HTML, tree, "dc.tag.not.allowed.here", treeName);
440    }
441
442    private void checkHeader(StartElementTree tree, HtmlTag tag) {
443        // verify the new tag
444        if (getHeaderLevel(tag) > getHeaderLevel(currHeaderTag) + 1) {
445            if (currHeaderTag == null) {
446                env.messages.error(ACCESSIBILITY, tree, "dc.tag.header.sequence.1", tag);
447            } else {
448                env.messages.error(ACCESSIBILITY, tree, "dc.tag.header.sequence.2",
449                    tag, currHeaderTag);
450            }
451        }
452
453        currHeaderTag = tag;
454    }
455
456    private int getHeaderLevel(HtmlTag tag) {
457        if (tag == null)
458            return implicitHeaderLevel;
459        switch (tag) {
460            case H1: return 1;
461            case H2: return 2;
462            case H3: return 3;
463            case H4: return 4;
464            case H5: return 5;
465            case H6: return 6;
466            default: throw new IllegalArgumentException();
467        }
468    }
469
470    @Override @DefinedBy(Api.COMPILER_TREE)
471    public Void visitEndElement(EndElementTree tree, Void ignore) {
472        final Name treeName = tree.getName();
473        final HtmlTag t = HtmlTag.get(treeName);
474        if (t == null) {
475            env.messages.error(HTML, tree, "dc.tag.unknown", treeName);
476        } else if (t.endKind == HtmlTag.EndKind.NONE) {
477            env.messages.error(HTML, tree, "dc.tag.end.not.permitted", treeName);
478        } else {
479            boolean done = false;
480            while (!tagStack.isEmpty()) {
481                TagStackItem top = tagStack.peek();
482                if (t == top.tag) {
483                    switch (t) {
484                        case TABLE:
485                            if (!top.attrs.contains(HtmlTag.Attr.SUMMARY)
486                                    && !top.flags.contains(Flag.TABLE_HAS_CAPTION)) {
487                                env.messages.error(ACCESSIBILITY, tree,
488                                        "dc.no.summary.or.caption.for.table");
489                            }
490                            break;
491
492                        case SECTION:
493                        case ARTICLE:
494                            if (env.htmlVersion == HtmlVersion.HTML5 && !top.flags.contains(Flag.HAS_HEADING)) {
495                                env.messages.error(HTML, tree, "dc.tag.requires.heading", treeName);
496                            }
497                            break;
498                    }
499                    warnIfEmpty(top, tree);
500                    tagStack.pop();
501                    done = true;
502                    break;
503                } else if (top.tag == null || top.tag.endKind != HtmlTag.EndKind.REQUIRED) {
504                    tagStack.pop();
505                } else {
506                    boolean found = false;
507                    for (TagStackItem si: tagStack) {
508                        if (si.tag == t) {
509                            found = true;
510                            break;
511                        }
512                    }
513                    if (found && top.tree.getKind() == DocTree.Kind.START_ELEMENT) {
514                        env.messages.error(HTML, top.tree, "dc.tag.start.unmatched",
515                                ((StartElementTree) top.tree).getName());
516                        tagStack.pop();
517                    } else {
518                        env.messages.error(HTML, tree, "dc.tag.end.unexpected", treeName);
519                        done = true;
520                        break;
521                    }
522                }
523            }
524
525            if (!done && tagStack.isEmpty()) {
526                env.messages.error(HTML, tree, "dc.tag.end.unexpected", treeName);
527            }
528        }
529
530        return super.visitEndElement(tree, ignore);
531    }
532
533    void warnIfEmpty(TagStackItem tsi, DocTree endTree) {
534        if (tsi.tag != null && tsi.tree instanceof StartElementTree) {
535            if (tsi.tag.flags.contains(HtmlTag.Flag.EXPECT_CONTENT)
536                    && !tsi.flags.contains(Flag.HAS_TEXT)
537                    && !tsi.flags.contains(Flag.HAS_ELEMENT)
538                    && !tsi.flags.contains(Flag.HAS_INLINE_TAG)) {
539                DocTree tree = (endTree != null) ? endTree : tsi.tree;
540                Name treeName = ((StartElementTree) tsi.tree).getName();
541                env.messages.warning(HTML, tree, "dc.tag.empty", treeName);
542            }
543        }
544    }
545
546    // </editor-fold>
547
548    // <editor-fold defaultstate="collapsed" desc="HTML attributes">
549
550    @Override @DefinedBy(Api.COMPILER_TREE) @SuppressWarnings("fallthrough")
551    public Void visitAttribute(AttributeTree tree, Void ignore) {
552        HtmlTag currTag = tagStack.peek().tag;
553        if (currTag != null) {
554            Name name = tree.getName();
555            HtmlTag.Attr attr = currTag.getAttr(name);
556            if (attr != null) {
557                if (env.htmlVersion == HtmlVersion.HTML4 && attr.name().contains("-")) {
558                    env.messages.error(HTML, tree, "dc.attr.not.supported.html4", name);
559                }
560                boolean first = tagStack.peek().attrs.add(attr);
561                if (!first)
562                    env.messages.error(HTML, tree, "dc.attr.repeated", name);
563            }
564            // for now, doclint allows all attribute names beginning with "on" as event handler names,
565            // without checking the validity or applicability of the name
566            if (!name.toString().startsWith("on")) {
567                AttrKind k = currTag.getAttrKind(name);
568                switch (env.htmlVersion) {
569                    case HTML4:
570                        validateHtml4Attrs(tree, name, k);
571                        break;
572
573                    case HTML5:
574                        validateHtml5Attrs(tree, name, k);
575                        break;
576                }
577            }
578
579            if (attr != null) {
580                switch (attr) {
581                    case NAME:
582                        if (currTag != HtmlTag.A) {
583                            break;
584                        }
585                        // fallthrough
586                    case ID:
587                        String value = getAttrValue(tree);
588                        if (value == null) {
589                            env.messages.error(HTML, tree, "dc.anchor.value.missing");
590                        } else {
591                            if (!validName.matcher(value).matches()) {
592                                env.messages.error(HTML, tree, "dc.invalid.anchor", value);
593                            }
594                            if (!checkAnchor(value)) {
595                                env.messages.error(HTML, tree, "dc.anchor.already.defined", value);
596                            }
597                        }
598                        break;
599
600                    case HREF:
601                        if (currTag == HtmlTag.A) {
602                            String v = getAttrValue(tree);
603                            if (v == null || v.isEmpty()) {
604                                env.messages.error(HTML, tree, "dc.attr.lacks.value");
605                            } else {
606                                Matcher m = docRoot.matcher(v);
607                                if (m.matches()) {
608                                    String rest = m.group(2);
609                                    if (!rest.isEmpty())
610                                        checkURI(tree, rest);
611                                } else {
612                                    checkURI(tree, v);
613                                }
614                            }
615                        }
616                        break;
617
618                    case VALUE:
619                        if (currTag == HtmlTag.LI) {
620                            String v = getAttrValue(tree);
621                            if (v == null || v.isEmpty()) {
622                                env.messages.error(HTML, tree, "dc.attr.lacks.value");
623                            } else if (!validNumber.matcher(v).matches()) {
624                                env.messages.error(HTML, tree, "dc.attr.not.number");
625                            }
626                        }
627                        break;
628
629                    case BORDER:
630                        if (currTag == HtmlTag.TABLE) {
631                            String v = getAttrValue(tree);
632                            try {
633                                if (env.htmlVersion == HtmlVersion.HTML5
634                                        && (v == null || (!v.isEmpty() && Integer.parseInt(v) != 1))) {
635                                    env.messages.error(HTML, tree, "dc.attr.table.border.html5", attr);
636                                }
637                            } catch (NumberFormatException ex) {
638                                env.messages.error(HTML, tree, "dc.attr.table.border.html5", attr);
639                            }
640                        }
641                        break;
642                }
643            }
644        }
645
646        // TODO: basic check on value
647
648        return super.visitAttribute(tree, ignore);
649    }
650
651    private void validateHtml4Attrs(AttributeTree tree, Name name, AttrKind k) {
652        switch (k) {
653            case ALL:
654            case HTML4:
655                break;
656
657            case INVALID:
658                env.messages.error(HTML, tree, "dc.attr.unknown", name);
659                break;
660
661            case OBSOLETE:
662                env.messages.warning(ACCESSIBILITY, tree, "dc.attr.obsolete", name);
663                break;
664
665            case USE_CSS:
666                env.messages.warning(ACCESSIBILITY, tree, "dc.attr.obsolete.use.css", name);
667                break;
668
669            case HTML5:
670                env.messages.error(HTML, tree, "dc.attr.not.supported.html4", name);
671                break;
672        }
673    }
674
675    private void validateHtml5Attrs(AttributeTree tree, Name name, AttrKind k) {
676        switch (k) {
677            case ALL:
678            case HTML5:
679                break;
680
681            case INVALID:
682            case OBSOLETE:
683            case USE_CSS:
684            case HTML4:
685                env.messages.error(HTML, tree, "dc.attr.not.supported.html5", name);
686                break;
687        }
688    }
689
690    private boolean checkAnchor(String name) {
691        Element e = getEnclosingPackageOrClass(env.currElement);
692        if (e == null)
693            return true;
694        Set<String> set = foundAnchors.get(e);
695        if (set == null)
696            foundAnchors.put(e, set = new HashSet<>());
697        return set.add(name);
698    }
699
700    private Element getEnclosingPackageOrClass(Element e) {
701        while (e != null) {
702            switch (e.getKind()) {
703                case CLASS:
704                case ENUM:
705                case INTERFACE:
706                case PACKAGE:
707                    return e;
708                default:
709                    e = e.getEnclosingElement();
710            }
711        }
712        return e;
713    }
714
715    // http://www.w3.org/TR/html401/types.html#type-name
716    private static final Pattern validName = Pattern.compile("[A-Za-z][A-Za-z0-9-_:.]*");
717
718    private static final Pattern validNumber = Pattern.compile("-?[0-9]+");
719
720    // pattern to remove leading {@docRoot}/?
721    private static final Pattern docRoot = Pattern.compile("(?i)(\\{@docRoot *\\}/?)?(.*)");
722
723    private String getAttrValue(AttributeTree tree) {
724        if (tree.getValue() == null)
725            return null;
726
727        StringWriter sw = new StringWriter();
728        try {
729            new DocPretty(sw).print(tree.getValue());
730        } catch (IOException e) {
731            // cannot happen
732        }
733        // ignore potential use of entities for now
734        return sw.toString();
735    }
736
737    private void checkURI(AttributeTree tree, String uri) {
738        // allow URIs beginning with javascript:, which would otherwise be rejected by the URI API.
739        if (uri.startsWith("javascript:"))
740            return;
741        try {
742            URI u = new URI(uri);
743        } catch (URISyntaxException e) {
744            env.messages.error(HTML, tree, "dc.invalid.uri", uri);
745        }
746    }
747    // </editor-fold>
748
749    // <editor-fold defaultstate="collapsed" desc="javadoc tags">
750
751    @Override @DefinedBy(Api.COMPILER_TREE)
752    public Void visitAuthor(AuthorTree tree, Void ignore) {
753        warnIfEmpty(tree, tree.getName());
754        return super.visitAuthor(tree, ignore);
755    }
756
757    @Override @DefinedBy(Api.COMPILER_TREE)
758    public Void visitDocRoot(DocRootTree tree, Void ignore) {
759        markEnclosingTag(Flag.HAS_INLINE_TAG);
760        return super.visitDocRoot(tree, ignore);
761    }
762
763    @Override @DefinedBy(Api.COMPILER_TREE)
764    public Void visitInheritDoc(InheritDocTree tree, Void ignore) {
765        markEnclosingTag(Flag.HAS_INLINE_TAG);
766        // TODO: verify on overridden method
767        foundInheritDoc = true;
768        return super.visitInheritDoc(tree, ignore);
769    }
770
771    @Override @DefinedBy(Api.COMPILER_TREE)
772    public Void visitLink(LinkTree tree, Void ignore) {
773        markEnclosingTag(Flag.HAS_INLINE_TAG);
774        // simulate inline context on tag stack
775        HtmlTag t = (tree.getKind() == DocTree.Kind.LINK)
776                ? HtmlTag.CODE : HtmlTag.SPAN;
777        tagStack.push(new TagStackItem(tree, t));
778        try {
779            return super.visitLink(tree, ignore);
780        } finally {
781            tagStack.pop();
782        }
783    }
784
785    @Override @DefinedBy(Api.COMPILER_TREE)
786    public Void visitLiteral(LiteralTree tree, Void ignore) {
787        markEnclosingTag(Flag.HAS_INLINE_TAG);
788        if (tree.getKind() == DocTree.Kind.CODE) {
789            for (TagStackItem tsi: tagStack) {
790                if (tsi.tag == HtmlTag.CODE) {
791                    env.messages.warning(HTML, tree, "dc.tag.code.within.code");
792                    break;
793                }
794            }
795        }
796        return super.visitLiteral(tree, ignore);
797    }
798
799    @Override @DefinedBy(Api.COMPILER_TREE)
800    @SuppressWarnings("fallthrough")
801    public Void visitParam(ParamTree tree, Void ignore) {
802        boolean typaram = tree.isTypeParameter();
803        IdentifierTree nameTree = tree.getName();
804        Element paramElement = nameTree != null ? env.trees.getElement(new DocTreePath(getCurrentPath(), nameTree)) : null;
805
806        if (paramElement == null) {
807            switch (env.currElement.getKind()) {
808                case CLASS: case INTERFACE: {
809                    if (!typaram) {
810                        env.messages.error(REFERENCE, tree, "dc.invalid.param");
811                        break;
812                    }
813                }
814                case METHOD: case CONSTRUCTOR: {
815                    env.messages.error(REFERENCE, nameTree, "dc.param.name.not.found");
816                    break;
817                }
818
819                default:
820                    env.messages.error(REFERENCE, tree, "dc.invalid.param");
821                    break;
822            }
823        } else {
824            foundParams.add(paramElement);
825        }
826
827        warnIfEmpty(tree, tree.getDescription());
828        return super.visitParam(tree, ignore);
829    }
830
831    private void checkParamsDocumented(List<? extends Element> list) {
832        if (foundInheritDoc)
833            return;
834
835        for (Element e: list) {
836            if (!foundParams.contains(e)) {
837                CharSequence paramName = (e.getKind() == ElementKind.TYPE_PARAMETER)
838                        ? "<" + e.getSimpleName() + ">"
839                        : e.getSimpleName();
840                reportMissing("dc.missing.param", paramName);
841            }
842        }
843    }
844
845    @Override @DefinedBy(Api.COMPILER_TREE)
846    public Void visitProvides(ProvidesTree tree, Void ignore) {
847        Element e = env.trees.getElement(env.currPath);
848        if (e.getKind() != ElementKind.MODULE) {
849            env.messages.error(REFERENCE, tree, "dc.invalid.provides");
850        }
851        ReferenceTree serviceType = tree.getServiceType();
852        Element se = env.trees.getElement(new DocTreePath(getCurrentPath(), serviceType));
853        if (se == null) {
854            env.messages.error(REFERENCE, tree, "dc.service.not.found");
855        }
856        return super.visitProvides(tree, ignore);
857    }
858
859    @Override @DefinedBy(Api.COMPILER_TREE)
860    public Void visitReference(ReferenceTree tree, Void ignore) {
861        String sig = tree.getSignature();
862        if (sig.contains("<") || sig.contains(">"))
863            env.messages.error(REFERENCE, tree, "dc.type.arg.not.allowed");
864
865        Element e = env.trees.getElement(getCurrentPath());
866        if (e == null)
867            env.messages.error(REFERENCE, tree, "dc.ref.not.found");
868        return super.visitReference(tree, ignore);
869    }
870
871    @Override @DefinedBy(Api.COMPILER_TREE)
872    public Void visitReturn(ReturnTree tree, Void ignore) {
873        Element e = env.trees.getElement(env.currPath);
874        if (e.getKind() != ElementKind.METHOD
875                || ((ExecutableElement) e).getReturnType().getKind() == TypeKind.VOID)
876            env.messages.error(REFERENCE, tree, "dc.invalid.return");
877        foundReturn = true;
878        warnIfEmpty(tree, tree.getDescription());
879        return super.visitReturn(tree, ignore);
880    }
881
882    @Override @DefinedBy(Api.COMPILER_TREE)
883    public Void visitSerialData(SerialDataTree tree, Void ignore) {
884        warnIfEmpty(tree, tree.getDescription());
885        return super.visitSerialData(tree, ignore);
886    }
887
888    @Override @DefinedBy(Api.COMPILER_TREE)
889    public Void visitSerialField(SerialFieldTree tree, Void ignore) {
890        warnIfEmpty(tree, tree.getDescription());
891        return super.visitSerialField(tree, ignore);
892    }
893
894    @Override @DefinedBy(Api.COMPILER_TREE)
895    public Void visitSince(SinceTree tree, Void ignore) {
896        warnIfEmpty(tree, tree.getBody());
897        return super.visitSince(tree, ignore);
898    }
899
900    @Override @DefinedBy(Api.COMPILER_TREE)
901    public Void visitThrows(ThrowsTree tree, Void ignore) {
902        ReferenceTree exName = tree.getExceptionName();
903        Element ex = env.trees.getElement(new DocTreePath(getCurrentPath(), exName));
904        if (ex == null) {
905            env.messages.error(REFERENCE, tree, "dc.ref.not.found");
906        } else if (isThrowable(ex.asType())) {
907            switch (env.currElement.getKind()) {
908                case CONSTRUCTOR:
909                case METHOD:
910                    if (isCheckedException(ex.asType())) {
911                        ExecutableElement ee = (ExecutableElement) env.currElement;
912                        checkThrowsDeclared(exName, ex.asType(), ee.getThrownTypes());
913                    }
914                    break;
915                default:
916                    env.messages.error(REFERENCE, tree, "dc.invalid.throws");
917            }
918        } else {
919            env.messages.error(REFERENCE, tree, "dc.invalid.throws");
920        }
921        warnIfEmpty(tree, tree.getDescription());
922        return scan(tree.getDescription(), ignore);
923    }
924
925    private boolean isThrowable(TypeMirror tm) {
926        switch (tm.getKind()) {
927            case DECLARED:
928            case TYPEVAR:
929                return env.types.isAssignable(tm, env.java_lang_Throwable);
930        }
931        return false;
932    }
933
934    private void checkThrowsDeclared(ReferenceTree tree, TypeMirror t, List<? extends TypeMirror> list) {
935        boolean found = false;
936        for (TypeMirror tl : list) {
937            if (env.types.isAssignable(t, tl)) {
938                foundThrows.add(tl);
939                found = true;
940            }
941        }
942        if (!found)
943            env.messages.error(REFERENCE, tree, "dc.exception.not.thrown", t);
944    }
945
946    private void checkThrowsDocumented(List<? extends TypeMirror> list) {
947        if (foundInheritDoc)
948            return;
949
950        for (TypeMirror tl: list) {
951            if (isCheckedException(tl) && !foundThrows.contains(tl))
952                reportMissing("dc.missing.throws", tl);
953        }
954    }
955
956    @Override @DefinedBy(Api.COMPILER_TREE)
957    public Void visitUnknownBlockTag(UnknownBlockTagTree tree, Void ignore) {
958        checkUnknownTag(tree, tree.getTagName());
959        return super.visitUnknownBlockTag(tree, ignore);
960    }
961
962    @Override @DefinedBy(Api.COMPILER_TREE)
963    public Void visitUnknownInlineTag(UnknownInlineTagTree tree, Void ignore) {
964        checkUnknownTag(tree, tree.getTagName());
965        return super.visitUnknownInlineTag(tree, ignore);
966    }
967
968    private void checkUnknownTag(DocTree tree, String tagName) {
969        if (env.customTags != null && !env.customTags.contains(tagName))
970            env.messages.error(SYNTAX, tree, "dc.tag.unknown", tagName);
971    }
972
973    @Override @DefinedBy(Api.COMPILER_TREE)
974    public Void visitUses(UsesTree tree, Void ignore) {
975        Element e = env.trees.getElement(env.currPath);
976        if (e.getKind() != ElementKind.MODULE) {
977            env.messages.error(REFERENCE, tree, "dc.invalid.uses");
978        }
979        ReferenceTree serviceType = tree.getServiceType();
980        Element se = env.trees.getElement(new DocTreePath(getCurrentPath(), serviceType));
981        if (se == null) {
982            env.messages.error(REFERENCE, tree, "dc.service.not.found");
983        }
984        return super.visitUses(tree, ignore);
985    }
986
987    @Override @DefinedBy(Api.COMPILER_TREE)
988    public Void visitValue(ValueTree tree, Void ignore) {
989        ReferenceTree ref = tree.getReference();
990        if (ref == null || ref.getSignature().isEmpty()) {
991            if (!isConstant(env.currElement))
992                env.messages.error(REFERENCE, tree, "dc.value.not.allowed.here");
993        } else {
994            Element e = env.trees.getElement(new DocTreePath(getCurrentPath(), ref));
995            if (!isConstant(e))
996                env.messages.error(REFERENCE, tree, "dc.value.not.a.constant");
997        }
998
999        markEnclosingTag(Flag.HAS_INLINE_TAG);
1000        return super.visitValue(tree, ignore);
1001    }
1002
1003    private boolean isConstant(Element e) {
1004        if (e == null)
1005            return false;
1006
1007        switch (e.getKind()) {
1008            case FIELD:
1009                Object value = ((VariableElement) e).getConstantValue();
1010                return (value != null); // can't distinguish "not a constant" from "constant is null"
1011            default:
1012                return false;
1013        }
1014    }
1015
1016    @Override @DefinedBy(Api.COMPILER_TREE)
1017    public Void visitVersion(VersionTree tree, Void ignore) {
1018        warnIfEmpty(tree, tree.getBody());
1019        return super.visitVersion(tree, ignore);
1020    }
1021
1022    @Override @DefinedBy(Api.COMPILER_TREE)
1023    public Void visitErroneous(ErroneousTree tree, Void ignore) {
1024        env.messages.error(SYNTAX, tree, null, tree.getDiagnostic().getMessage(null));
1025        return null;
1026    }
1027    // </editor-fold>
1028
1029    // <editor-fold defaultstate="collapsed" desc="Utility methods">
1030
1031    private boolean isCheckedException(TypeMirror t) {
1032        return !(env.types.isAssignable(t, env.java_lang_Error)
1033                || env.types.isAssignable(t, env.java_lang_RuntimeException));
1034    }
1035
1036    private boolean isSynthetic() {
1037        switch (env.currElement.getKind()) {
1038            case CONSTRUCTOR:
1039                // A synthetic default constructor has the same pos as the
1040                // enclosing class
1041                TreePath p = env.currPath;
1042                return env.getPos(p) == env.getPos(p.getParentPath());
1043        }
1044        return false;
1045    }
1046
1047    void markEnclosingTag(Flag flag) {
1048        TagStackItem top = tagStack.peek();
1049        if (top != null)
1050            top.flags.add(flag);
1051    }
1052
1053    String toString(TreePath p) {
1054        StringBuilder sb = new StringBuilder("TreePath[");
1055        toString(p, sb);
1056        sb.append("]");
1057        return sb.toString();
1058    }
1059
1060    void toString(TreePath p, StringBuilder sb) {
1061        TreePath parent = p.getParentPath();
1062        if (parent != null) {
1063            toString(parent, sb);
1064            sb.append(",");
1065        }
1066       sb.append(p.getLeaf().getKind()).append(":").append(env.getPos(p)).append(":S").append(env.getStartPos(p));
1067    }
1068
1069    void warnIfEmpty(DocTree tree, List<? extends DocTree> list) {
1070        for (DocTree d: list) {
1071            switch (d.getKind()) {
1072                case TEXT:
1073                    if (hasNonWhitespace((TextTree) d))
1074                        return;
1075                    break;
1076                default:
1077                    return;
1078            }
1079        }
1080        env.messages.warning(SYNTAX, tree, "dc.empty", tree.getKind().tagName);
1081    }
1082
1083    boolean hasNonWhitespace(TextTree tree) {
1084        String s = tree.getBody();
1085        for (int i = 0; i < s.length(); i++) {
1086            if (!Character.isWhitespace(s.charAt(i)))
1087                return true;
1088        }
1089        return false;
1090    }
1091
1092    // </editor-fold>
1093
1094}
1095