1 /*

     2  * Copyright (c) 2012, 2017, 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 

    26 package com.sun.tools.doclint;

    27 

    28 import java.io.IOException;

    29 import java.io.StringWriter;

    30 import java.net.URI;

    31 import java.net.URISyntaxException;

    32 import java.util.Deque;

    33 import java.util.EnumSet;

    34 import java.util.HashMap;

    35 import java.util.HashSet;

    36 import java.util.LinkedList;

    37 import java.util.List;

    38 import java.util.Map;

    39 import java.util.Set;

    40 import java.util.regex.Matcher;

    41 import java.util.regex.Pattern;

    42 

    43 import javax.lang.model.element.Element;

    44 import javax.lang.model.element.ElementKind;

    45 import javax.lang.model.element.ExecutableElement;

    46 import javax.lang.model.element.Name;

    47 import javax.lang.model.element.VariableElement;

    48 import javax.lang.model.type.TypeKind;

    49 import javax.lang.model.type.TypeMirror;

    50 import javax.tools.Diagnostic.Kind;

    51 import javax.tools.JavaFileObject;

    52 

    53 import com.sun.source.doctree.AttributeTree;

    54 import com.sun.source.doctree.AuthorTree;

    55 import com.sun.source.doctree.DocCommentTree;

    56 import com.sun.source.doctree.DocRootTree;

    57 import com.sun.source.doctree.DocTree;

    58 import com.sun.source.doctree.EndElementTree;

    59 import com.sun.source.doctree.EntityTree;

    60 import com.sun.source.doctree.ErroneousTree;

    61 import com.sun.source.doctree.IdentifierTree;

    62 import com.sun.source.doctree.InheritDocTree;

    63 import com.sun.source.doctree.LinkTree;

    64 import com.sun.source.doctree.LiteralTree;

    65 import com.sun.source.doctree.ParamTree;

    66 import com.sun.source.doctree.ProvidesTree;

    67 import com.sun.source.doctree.ReferenceTree;

    68 import com.sun.source.doctree.ReturnTree;

    69 import com.sun.source.doctree.SerialDataTree;

    70 import com.sun.source.doctree.SerialFieldTree;

    71 import com.sun.source.doctree.SinceTree;

    72 import com.sun.source.doctree.StartElementTree;

    73 import com.sun.source.doctree.SummaryTree;

    74 import com.sun.source.doctree.TextTree;

    75 import com.sun.source.doctree.ThrowsTree;

    76 import com.sun.source.doctree.UnknownBlockTagTree;

    77 import com.sun.source.doctree.UnknownInlineTagTree;

    78 import com.sun.source.doctree.UsesTree;

    79 import com.sun.source.doctree.ValueTree;

    80 import com.sun.source.doctree.VersionTree;

    81 import com.sun.source.tree.Tree;

    82 import com.sun.source.util.DocTreePath;

    83 import com.sun.source.util.DocTreePathScanner;

    84 import com.sun.source.util.TreePath;

    85 import com.sun.tools.doclint.HtmlTag.AttrKind;

    86 import com.sun.tools.javac.tree.DocPretty;

    87 import com.sun.tools.javac.util.Assert;

    88 import com.sun.tools.javac.util.DefinedBy;

    89 import com.sun.tools.javac.util.DefinedBy.Api;

    90 import com.sun.tools.javac.util.StringUtils;

    91 

    92 import static com.sun.tools.doclint.Messages.Group.*;

    93 

    94 

    95 /**

    96  * Validate a doc comment.

    97  *

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

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

   100  * risk.  This code and its internal interfaces are subject to change

   101  * or deletion without notice.</b></p>

   102  */

   103 public class Checker extends DocTreePathScanner<Void, Void> {

   104     final Env env;

   105 

   106     Set<Element> foundParams = new HashSet<>();

   107     Set<TypeMirror> foundThrows = new HashSet<>();

   108     Map<Element, Set<String>> foundAnchors = new HashMap<>();

   109     boolean foundInheritDoc = false;

   110     boolean foundReturn = false;

   111     boolean hasNonWhitespaceText = false;

   112 

   113     public enum Flag {

   114         TABLE_HAS_CAPTION,

   115         HAS_ELEMENT,

   116         HAS_HEADING,

   117         HAS_INLINE_TAG,

   118         HAS_TEXT,

   119         REPORTED_BAD_INLINE

   120     }

   121 

   122     static class TagStackItem {

   123         final DocTree tree; // typically, but not always, StartElementTree

   124         final HtmlTag tag;

   125         final Set<HtmlTag.Attr> attrs;

   126         final Set<Flag> flags;

   127         TagStackItem(DocTree tree, HtmlTag tag) {

   128             this.tree = tree;

   129             this.tag = tag;

   130             attrs = EnumSet.noneOf(HtmlTag.Attr.class);

   131             flags = EnumSet.noneOf(Flag.class);

   132         }

   133         @Override

   134         public String toString() {

   135             return String.valueOf(tag);

   136         }

   137     }

   138 

   139     private final Deque<TagStackItem> tagStack; // TODO: maybe want to record starting tree as well

   140     private HtmlTag currHeaderTag;

   141 

   142     private final int implicitHeaderLevel;

   143 

   144     // <editor-fold defaultstate="collapsed" desc="Top level">

   145 

   146     Checker(Env env) {

   147         this.env = Assert.checkNonNull(env);

   148         tagStack = new LinkedList<>();

   149         implicitHeaderLevel = env.implicitHeaderLevel;

   150     }

   151 

   152     public Void scan(DocCommentTree tree, TreePath p) {

   153         env.initTypes();

   154         env.setCurrent(p, tree);

   155 

   156         boolean isOverridingMethod = !env.currOverriddenMethods.isEmpty();

   157         JavaFileObject fo = p.getCompilationUnit().getSourceFile();

   158 

   159         if (p.getLeaf().getKind() == Tree.Kind.PACKAGE) {

   160             // If p points to a package, the implied declaration is the

   161             // package declaration (if any) for the compilation unit.

   162             // Handle this case specially, because doc comments are only

   163             // expected in package-info files.

   164             boolean isPkgInfo = fo.isNameCompatible("package-info", JavaFileObject.Kind.SOURCE);

   165             if (tree == null) {

   166                 if (isPkgInfo)

   167                     reportMissing("dc.missing.comment");

   168                 return null;

   169             } else {

   170                 if (!isPkgInfo)

   171                     reportReference("dc.unexpected.comment");

   172             }

   173         } else if (tree != null && fo.isNameCompatible("package", JavaFileObject.Kind.HTML)) {

   174             // a package.html file with a DocCommentTree

   175             if (tree.getFullBody().isEmpty()) {

   176                 reportMissing("dc.missing.comment");

   177                 return null;

   178             }

   179         } else {

   180             if (tree == null) {

   181                 if (!isSynthetic() && !isOverridingMethod)

   182                     reportMissing("dc.missing.comment");

   183                 return null;

   184             }

   185         }

   186 

   187         tagStack.clear();

   188         currHeaderTag = null;

   189 

   190         foundParams.clear();

   191         foundThrows.clear();

   192         foundInheritDoc = false;

   193         foundReturn = false;

   194         hasNonWhitespaceText = false;

   195 

   196         scan(new DocTreePath(p, tree), null);

   197 

   198         if (!isOverridingMethod) {

   199             switch (env.currElement.getKind()) {

   200                 case METHOD:

   201                 case CONSTRUCTOR: {

   202                     ExecutableElement ee = (ExecutableElement) env.currElement;

   203                     checkParamsDocumented(ee.getTypeParameters());

   204                     checkParamsDocumented(ee.getParameters());

   205                     switch (ee.getReturnType().getKind()) {

   206                         case VOID:

   207                         case NONE:

   208                             break;

   209                         default:

   210                             if (!foundReturn

   211                                     && !foundInheritDoc

   212                                     && !env.types.isSameType(ee.getReturnType(), env.java_lang_Void)) {

   213                                 reportMissing("dc.missing.return");

   214                             }

   215                     }

   216                     checkThrowsDocumented(ee.getThrownTypes());

   217                 }

   218             }

   219         }

   220 

   221         return null;

   222     }

   223 

   224     private void reportMissing(String code, Object... args) {

   225         env.messages.report(MISSING, Kind.WARNING, env.currPath.getLeaf(), code, args);

   226     }

   227 

   228     private void reportReference(String code, Object... args) {

   229         env.messages.report(REFERENCE, Kind.WARNING, env.currPath.getLeaf(), code, args);

   230     }

   231 

   232     @Override @DefinedBy(Api.COMPILER_TREE)

   233     public Void visitDocComment(DocCommentTree tree, Void ignore) {

   234         super.visitDocComment(tree, ignore);

   235         for (TagStackItem tsi: tagStack) {

   236             warnIfEmpty(tsi, null);

   237             if (tsi.tree.getKind() == DocTree.Kind.START_ELEMENT

   238                     && tsi.tag.endKind == HtmlTag.EndKind.REQUIRED) {

   239                 StartElementTree t = (StartElementTree) tsi.tree;

   240                 env.messages.error(HTML, t, "dc.tag.not.closed", t.getName());

   241             }

   242         }

   243         return null;

   244     }

   245     // </editor-fold>

   246 

   247     // <editor-fold defaultstate="collapsed" desc="Text and entities.">

   248 

   249     @Override @DefinedBy(Api.COMPILER_TREE)

   250     public Void visitText(TextTree tree, Void ignore) {

   251         hasNonWhitespaceText = hasNonWhitespace(tree);

   252         if (hasNonWhitespaceText) {

   253             checkAllowsText(tree);

   254             markEnclosingTag(Flag.HAS_TEXT);

   255         }

   256         return null;

   257     }

   258 

   259     @Override @DefinedBy(Api.COMPILER_TREE)

   260     public Void visitEntity(EntityTree tree, Void ignore) {

   261         checkAllowsText(tree);

   262         markEnclosingTag(Flag.HAS_TEXT);

   263         String name = tree.getName().toString();

   264         if (name.startsWith("#")) {

   265             int v = StringUtils.toLowerCase(name).startsWith("#x")

   266                     ? Integer.parseInt(name.substring(2), 16)

   267                     : Integer.parseInt(name.substring(1), 10);

   268             if (!Entity.isValid(v)) {

   269                 env.messages.error(HTML, tree, "dc.entity.invalid", name);

   270             }

   271         } else if (!Entity.isValid(name)) {

   272             env.messages.error(HTML, tree, "dc.entity.invalid", name);

   273         }

   274         return null;

   275     }

   276 

   277     void checkAllowsText(DocTree tree) {

   278         TagStackItem top = tagStack.peek();

   279         if (top != null

   280                 && top.tree.getKind() == DocTree.Kind.START_ELEMENT

   281                 && !top.tag.acceptsText()) {

   282             if (top.flags.add(Flag.REPORTED_BAD_INLINE)) {

   283                 env.messages.error(HTML, tree, "dc.text.not.allowed",

   284                         ((StartElementTree) top.tree).getName());

   285             }

   286         }

   287     }

   288 

   289     // </editor-fold>

   290 

   291     // <editor-fold defaultstate="collapsed" desc="HTML elements">

   292 

   293     @Override @DefinedBy(Api.COMPILER_TREE)

   294     public Void visitStartElement(StartElementTree tree, Void ignore) {

   295         final Name treeName = tree.getName();

   296         final HtmlTag t = HtmlTag.get(treeName);

   297         if (t == null) {

   298             env.messages.error(HTML, tree, "dc.tag.unknown", treeName);

   299         } else if (t.allowedVersion != HtmlVersion.ALL && t.allowedVersion != env.htmlVersion) {

   300             env.messages.error(HTML, tree, "dc.tag.not.supported", treeName);

   301         } else {

   302             boolean done = false;

   303             for (TagStackItem tsi: tagStack) {

   304                 if (tsi.tag.accepts(t)) {

   305                     while (tagStack.peek() != tsi) {

   306                         warnIfEmpty(tagStack.peek(), null);

   307                         tagStack.pop();

   308                     }

   309                     done = true;

   310                     break;

   311                 } else if (tsi.tag.endKind != HtmlTag.EndKind.OPTIONAL) {

   312                     done = true;

   313                     break;

   314                 }

   315             }

   316             if (!done && HtmlTag.BODY.accepts(t)) {

   317                 while (!tagStack.isEmpty()) {

   318                     warnIfEmpty(tagStack.peek(), null);

   319                     tagStack.pop();

   320                 }

   321             }

   322 

   323             markEnclosingTag(Flag.HAS_ELEMENT);

   324             checkStructure(tree, t);

   325 

   326             // tag specific checks

   327             switch (t) {

   328                 // check for out of sequence headers, such as <h1>...</h1>  <h3>...</h3>

   329                 case H1: case H2: case H3: case H4: case H5: case H6:

   330                     checkHeader(tree, t);

   331                     break;

   332             }

   333 

   334             if (t.flags.contains(HtmlTag.Flag.NO_NEST)) {

   335                 for (TagStackItem i: tagStack) {

   336                     if (t == i.tag) {

   337                         env.messages.warning(HTML, tree, "dc.tag.nested.not.allowed", treeName);

   338                         break;

   339                     }

   340                 }

   341             }

   342         }

   343 

   344         // check for self closing tags, such as <a id="name"/>

   345         if (tree.isSelfClosing()) {

   346             env.messages.error(HTML, tree, "dc.tag.self.closing", treeName);

   347         }

   348 

   349         try {

   350             TagStackItem parent = tagStack.peek();

   351             TagStackItem top = new TagStackItem(tree, t);

   352             tagStack.push(top);

   353 

   354             super.visitStartElement(tree, ignore);

   355 

   356             // handle attributes that may or may not have been found in start element

   357             if (t != null) {

   358                 switch (t) {

   359                     case CAPTION:

   360                         if (parent != null && parent.tag == HtmlTag.TABLE)

   361                             parent.flags.add(Flag.TABLE_HAS_CAPTION);

   362                         break;

   363 

   364                     case H1: case H2: case H3: case H4: case H5: case H6:

   365                         if (parent != null && (parent.tag == HtmlTag.SECTION || parent.tag == HtmlTag.ARTICLE)) {

   366                             parent.flags.add(Flag.HAS_HEADING);

   367                         }

   368                         break;

   369 

   370                     case IMG:

   371                         if (!top.attrs.contains(HtmlTag.Attr.ALT))

   372                             env.messages.error(ACCESSIBILITY, tree, "dc.no.alt.attr.for.image");

   373                         break;

   374                 }

   375             }

   376 

   377             return null;

   378         } finally {

   379 

   380             if (t == null || t.endKind == HtmlTag.EndKind.NONE)

   381                 tagStack.pop();

   382         }

   383     }

   384 

   385     private void checkStructure(StartElementTree tree, HtmlTag t) {

   386         Name treeName = tree.getName();

   387         TagStackItem top = tagStack.peek();

   388         switch (t.blockType) {

   389             case BLOCK:

   390                 if (top == null || top.tag.accepts(t))

   391                     return;

   392 

   393                 switch (top.tree.getKind()) {

   394                     case START_ELEMENT: {

   395                         if (top.tag.blockType == HtmlTag.BlockType.INLINE) {

   396                             Name name = ((StartElementTree) top.tree).getName();

   397                             env.messages.error(HTML, tree, "dc.tag.not.allowed.inline.element",

   398                                     treeName, name);

   399                             return;

   400                         }

   401                     }

   402                     break;

   403 

   404                     case LINK:

   405                     case LINK_PLAIN: {

   406                         String name = top.tree.getKind().tagName;

   407                         env.messages.error(HTML, tree, "dc.tag.not.allowed.inline.tag",

   408                                 treeName, name);

   409                         return;

   410                     }

   411                 }

   412                 break;

   413 

   414             case INLINE:

   415                 if (top == null || top.tag.accepts(t))

   416                     return;

   417                 break;

   418 

   419             case LIST_ITEM:

   420             case TABLE_ITEM:

   421                 if (top != null) {

   422                     // reset this flag so subsequent bad inline content gets reported

   423                     top.flags.remove(Flag.REPORTED_BAD_INLINE);

   424                     if (top.tag.accepts(t))

   425                         return;

   426                 }

   427                 break;

   428 

   429             case OTHER:

   430                 switch (t) {

   431                     case SCRIPT:

   432                         // <script> may or may not be allowed, depending on --allow-script-in-comments

   433                         // but we allow it here, and rely on a separate scanner to detect all uses

   434                         // of JavaScript, including <script> tags, and use in attributes, etc.

   435                         break;

   436 

   437                     default:

   438                         env.messages.error(HTML, tree, "dc.tag.not.allowed", treeName);

   439                 }

   440                 return;

   441         }

   442 

   443         env.messages.error(HTML, tree, "dc.tag.not.allowed.here", treeName);

   444     }

   445 

   446     private void checkHeader(StartElementTree tree, HtmlTag tag) {

   447         // verify the new tag

   448         if (getHeaderLevel(tag) > getHeaderLevel(currHeaderTag) + 1) {

   449             if (currHeaderTag == null) {

   450                 env.messages.error(ACCESSIBILITY, tree, "dc.tag.header.sequence.1", tag);

   451             } else {

   452                 env.messages.error(ACCESSIBILITY, tree, "dc.tag.header.sequence.2",

   453                     tag, currHeaderTag);

   454             }

   455         }

   456 

   457         currHeaderTag = tag;

   458     }

   459 

   460     private int getHeaderLevel(HtmlTag tag) {

   461         if (tag == null)

   462             return implicitHeaderLevel;

   463         switch (tag) {

   464             case H1: return 1;

   465             case H2: return 2;

   466             case H3: return 3;

   467             case H4: return 4;

   468             case H5: return 5;

   469             case H6: return 6;

   470             default: throw new IllegalArgumentException();

   471         }

   472     }

   473 

   474     @Override @DefinedBy(Api.COMPILER_TREE)

   475     public Void visitEndElement(EndElementTree tree, Void ignore) {

   476         final Name treeName = tree.getName();

   477         final HtmlTag t = HtmlTag.get(treeName);

   478         if (t == null) {

   479             env.messages.error(HTML, tree, "dc.tag.unknown", treeName);

   480         } else if (t.endKind == HtmlTag.EndKind.NONE) {

   481             env.messages.error(HTML, tree, "dc.tag.end.not.permitted", treeName);

   482         } else {

   483             boolean done = false;

   484             while (!tagStack.isEmpty()) {

   485                 TagStackItem top = tagStack.peek();

   486                 if (t == top.tag) {

   487                     switch (t) {

   488                         case TABLE:

   489                             if (!top.attrs.contains(HtmlTag.Attr.SUMMARY)

   490                                     && !top.flags.contains(Flag.TABLE_HAS_CAPTION)) {

   491                                 env.messages.error(ACCESSIBILITY, tree,

   492                                         "dc.no.summary.or.caption.for.table");

   493                             }

   494                             break;

   495 

   496                         case SECTION:

   497                         case ARTICLE:

   498                             if (env.htmlVersion == HtmlVersion.HTML5 && !top.flags.contains(Flag.HAS_HEADING)) {

   499                                 env.messages.error(HTML, tree, "dc.tag.requires.heading", treeName);

   500                             }

   501                             break;

   502                     }

   503                     warnIfEmpty(top, tree);

   504                     tagStack.pop();

   505                     done = true;

   506                     break;

   507                 } else if (top.tag == null || top.tag.endKind != HtmlTag.EndKind.REQUIRED) {

   508                     tagStack.pop();

   509                 } else {

   510                     boolean found = false;

   511                     for (TagStackItem si: tagStack) {

   512                         if (si.tag == t) {

   513                             found = true;

   514                             break;

   515                         }

   516                     }

   517                     if (found && top.tree.getKind() == DocTree.Kind.START_ELEMENT) {

   518                         env.messages.error(HTML, top.tree, "dc.tag.start.unmatched",

   519                                 ((StartElementTree) top.tree).getName());

   520                         tagStack.pop();

   521                     } else {

   522                         env.messages.error(HTML, tree, "dc.tag.end.unexpected", treeName);

   523                         done = true;

   524                         break;

   525                     }

   526                 }

   527             }

   528 

   529             if (!done && tagStack.isEmpty()) {

   530                 env.messages.error(HTML, tree, "dc.tag.end.unexpected", treeName);

   531             }

   532         }

   533 

   534         return super.visitEndElement(tree, ignore);

   535     }

   536 

   537     void warnIfEmpty(TagStackItem tsi, DocTree endTree) {

   538         if (tsi.tag != null && tsi.tree instanceof StartElementTree) {

   539             if (tsi.tag.flags.contains(HtmlTag.Flag.EXPECT_CONTENT)

   540                     && !tsi.flags.contains(Flag.HAS_TEXT)

   541                     && !tsi.flags.contains(Flag.HAS_ELEMENT)

   542                     && !tsi.flags.contains(Flag.HAS_INLINE_TAG)) {

   543                 DocTree tree = (endTree != null) ? endTree : tsi.tree;

   544                 Name treeName = ((StartElementTree) tsi.tree).getName();

   545                 env.messages.warning(HTML, tree, "dc.tag.empty", treeName);

   546             }

   547         }

   548     }

   549 

   550     // </editor-fold>

   551 

   552     // <editor-fold defaultstate="collapsed" desc="HTML attributes">

   553 

   554     @Override @DefinedBy(Api.COMPILER_TREE) @SuppressWarnings("fallthrough")

   555     public Void visitAttribute(AttributeTree tree, Void ignore) {

   556         HtmlTag currTag = tagStack.peek().tag;

   557         if (currTag != null) {

   558             Name name = tree.getName();

   559             HtmlTag.Attr attr = currTag.getAttr(name);

   560             if (attr != null) {

   561                 if (env.htmlVersion == HtmlVersion.HTML4 && attr.name().contains("-")) {

   562                     env.messages.error(HTML, tree, "dc.attr.not.supported.html4", name);

   563                 }

   564                 boolean first = tagStack.peek().attrs.add(attr);

   565                 if (!first)

   566                     env.messages.error(HTML, tree, "dc.attr.repeated", name);

   567             }

   568             // for now, doclint allows all attribute names beginning with "on" as event handler names,

   569             // without checking the validity or applicability of the name

   570             if (!name.toString().startsWith("on")) {

   571                 AttrKind k = currTag.getAttrKind(name);

   572                 switch (env.htmlVersion) {

   573                     case HTML4:

   574                         validateHtml4Attrs(tree, name, k);

   575                         break;

   576 

   577                     case HTML5:

   578                         validateHtml5Attrs(tree, name, k);

   579                         break;

   580                 }

   581             }

   582 

   583             if (attr != null) {

   584                 switch (attr) {

   585                     case NAME:

   586                         if (currTag != HtmlTag.A) {

   587                             break;

   588                         }

   589                         // fallthrough

   590                     case ID:

   591                         String value = getAttrValue(tree);

   592                         if (value == null) {

   593                             env.messages.error(HTML, tree, "dc.anchor.value.missing");

   594                         } else {

   595                             if (!validName.matcher(value).matches()) {

   596                                 env.messages.error(HTML, tree, "dc.invalid.anchor", value);

   597                             }

   598                             if (!checkAnchor(value)) {

   599                                 env.messages.error(HTML, tree, "dc.anchor.already.defined", value);

   600                             }

   601                         }

   602                         break;

   603 

   604                     case HREF:

   605                         if (currTag == HtmlTag.A) {

   606                             String v = getAttrValue(tree);

   607                             if (v == null || v.isEmpty()) {

   608                                 env.messages.error(HTML, tree, "dc.attr.lacks.value");

   609                             } else {

   610                                 Matcher m = docRoot.matcher(v);

   611                                 if (m.matches()) {

   612                                     String rest = m.group(2);

   613                                     if (!rest.isEmpty())

   614                                         checkURI(tree, rest);

   615                                 } else {

   616                                     checkURI(tree, v);

   617                                 }

   618                             }

   619                         }

   620                         break;

   621 

   622                     case VALUE:

   623                         if (currTag == HtmlTag.LI) {

   624                             String v = getAttrValue(tree);

   625                             if (v == null || v.isEmpty()) {

   626                                 env.messages.error(HTML, tree, "dc.attr.lacks.value");

   627                             } else if (!validNumber.matcher(v).matches()) {

   628                                 env.messages.error(HTML, tree, "dc.attr.not.number");

   629                             }

   630                         }

   631                         break;

   632 

   633                     case BORDER:

   634                         if (currTag == HtmlTag.TABLE) {

   635                             String v = getAttrValue(tree);

   636                             try {

   637                                 if (env.htmlVersion == HtmlVersion.HTML5

   638                                         && (v == null || (!v.isEmpty() && Integer.parseInt(v) != 1))) {

   639                                     env.messages.error(HTML, tree, "dc.attr.table.border.html5", attr);

   640                                 }

   641                             } catch (NumberFormatException ex) {

   642                                 env.messages.error(HTML, tree, "dc.attr.table.border.html5", attr);

   643                             }

   644                         }

   645                         break;

   646                 }

   647             }

   648         }

   649 

   650         // TODO: basic check on value

   651 

   652         return super.visitAttribute(tree, ignore);

   653     }

   654 

   655     private void validateHtml4Attrs(AttributeTree tree, Name name, AttrKind k) {

   656         switch (k) {

   657             case ALL:

   658             case HTML4:

   659                 break;

   660 

   661             case INVALID:

   662                 env.messages.error(HTML, tree, "dc.attr.unknown", name);

   663                 break;

   664 

   665             case OBSOLETE:

   666                 env.messages.warning(ACCESSIBILITY, tree, "dc.attr.obsolete", name);

   667                 break;

   668 

   669             case USE_CSS:

   670                 env.messages.warning(ACCESSIBILITY, tree, "dc.attr.obsolete.use.css", name);

   671                 break;

   672 

   673             case HTML5:

   674                 env.messages.error(HTML, tree, "dc.attr.not.supported.html4", name);

   675                 break;

   676         }

   677     }

   678 

   679     private void validateHtml5Attrs(AttributeTree tree, Name name, AttrKind k) {

   680         switch (k) {

   681             case ALL:

   682             case HTML5:

   683                 break;

   684 

   685             case INVALID:

   686             case OBSOLETE:

   687             case USE_CSS:

   688             case HTML4:

   689                 env.messages.error(HTML, tree, "dc.attr.not.supported.html5", name);

   690                 break;

   691         }

   692     }

   693 

   694     private boolean checkAnchor(String name) {

   695         Element e = getEnclosingPackageOrClass(env.currElement);

   696         if (e == null)

   697             return true;

   698         Set<String> set = foundAnchors.get(e);

   699         if (set == null)

   700             foundAnchors.put(e, set = new HashSet<>());

   701         return set.add(name);

   702     }

   703 

   704     private Element getEnclosingPackageOrClass(Element e) {

   705         while (e != null) {

   706             switch (e.getKind()) {

   707                 case CLASS:

   708                 case ENUM:

   709                 case INTERFACE:

   710                 case PACKAGE:

   711                     return e;

   712                 default:

   713                     e = e.getEnclosingElement();

   714             }

   715         }

   716         return e;

   717     }

   718 

   719     // http://www.w3.org/TR/html401/types.html#type-name

   720     private static final Pattern validName = Pattern.compile("[A-Za-z][A-Za-z0-9-_:.]*");

   721 

   722     private static final Pattern validNumber = Pattern.compile("-?[0-9]+");

   723 

   724     // pattern to remove leading {@docRoot}/?

   725     private static final Pattern docRoot = Pattern.compile("(?i)(\\{@docRoot *\\}/?)?(.*)");

   726 

   727     private String getAttrValue(AttributeTree tree) {

   728         if (tree.getValue() == null)

   729             return null;

   730 

   731         StringWriter sw = new StringWriter();

   732         try {

   733             new DocPretty(sw).print(tree.getValue());

   734         } catch (IOException e) {

   735             // cannot happen

   736         }

   737         // ignore potential use of entities for now

   738         return sw.toString();

   739     }

   740 

   741     private void checkURI(AttributeTree tree, String uri) {

   742         // allow URIs beginning with javascript:, which would otherwise be rejected by the URI API.

   743         if (uri.startsWith("javascript:"))

   744             return;

   745         try {

   746             URI u = new URI(uri);

   747         } catch (URISyntaxException e) {

   748             env.messages.error(HTML, tree, "dc.invalid.uri", uri);

   749         }

   750     }

   751     // </editor-fold>

   752 

   753     // <editor-fold defaultstate="collapsed" desc="javadoc tags">

   754 

   755     @Override @DefinedBy(Api.COMPILER_TREE)

   756     public Void visitAuthor(AuthorTree tree, Void ignore) {

   757         warnIfEmpty(tree, tree.getName());

   758         return super.visitAuthor(tree, ignore);

   759     }

   760 

   761     @Override @DefinedBy(Api.COMPILER_TREE)

   762     public Void visitDocRoot(DocRootTree tree, Void ignore) {

   763         markEnclosingTag(Flag.HAS_INLINE_TAG);

   764         return super.visitDocRoot(tree, ignore);

   765     }

   766 

   767     @Override @DefinedBy(Api.COMPILER_TREE)

   768     public Void visitInheritDoc(InheritDocTree tree, Void ignore) {

   769         markEnclosingTag(Flag.HAS_INLINE_TAG);

   770         // TODO: verify on overridden method

   771         foundInheritDoc = true;

   772         return super.visitInheritDoc(tree, ignore);

   773     }

   774 

   775     @Override @DefinedBy(Api.COMPILER_TREE)

   776     public Void visitLink(LinkTree tree, Void ignore) {

   777         markEnclosingTag(Flag.HAS_INLINE_TAG);

   778         // simulate inline context on tag stack

   779         HtmlTag t = (tree.getKind() == DocTree.Kind.LINK)

   780                 ? HtmlTag.CODE : HtmlTag.SPAN;

   781         tagStack.push(new TagStackItem(tree, t));

   782         try {

   783             return super.visitLink(tree, ignore);

   784         } finally {

   785             tagStack.pop();

   786         }

   787     }

   788 

   789     @Override @DefinedBy(Api.COMPILER_TREE)

   790     public Void visitLiteral(LiteralTree tree, Void ignore) {

   791         markEnclosingTag(Flag.HAS_INLINE_TAG);

   792         if (tree.getKind() == DocTree.Kind.CODE) {

   793             for (TagStackItem tsi: tagStack) {

   794                 if (tsi.tag == HtmlTag.CODE) {

   795                     env.messages.warning(HTML, tree, "dc.tag.code.within.code");

   796                     break;

   797                 }

   798             }

   799         }

   800         return super.visitLiteral(tree, ignore);

   801     }

   802 

   803     @Override @DefinedBy(Api.COMPILER_TREE)

   804     @SuppressWarnings("fallthrough")

   805     public Void visitParam(ParamTree tree, Void ignore) {

   806         boolean typaram = tree.isTypeParameter();

   807         IdentifierTree nameTree = tree.getName();

   808         Element paramElement = nameTree != null ? env.trees.getElement(new DocTreePath(getCurrentPath(), nameTree)) : null;

   809 

   810         if (paramElement == null) {

   811             switch (env.currElement.getKind()) {

   812                 case CLASS: case INTERFACE: {

   813                     if (!typaram) {

   814                         env.messages.error(REFERENCE, tree, "dc.invalid.param");

   815                         break;

   816                     }

   817                 }

   818                 case METHOD: case CONSTRUCTOR: {

   819                     env.messages.error(REFERENCE, nameTree, "dc.param.name.not.found");

   820                     break;

   821                 }

   822 

   823                 default:

   824                     env.messages.error(REFERENCE, tree, "dc.invalid.param");

   825                     break;

   826             }

   827         } else {

   828             boolean unique = foundParams.add(paramElement);

   829 

   830             if (!unique) {

   831                 env.messages.warning(REFERENCE, tree, "dc.exists.param", nameTree);

   832             }

   833         }

   834 

   835         warnIfEmpty(tree, tree.getDescription());

   836         return super.visitParam(tree, ignore);

   837     }

   838 

   839     private void checkParamsDocumented(List<? extends Element> list) {

   840         if (foundInheritDoc)

   841             return;

   842 

   843         for (Element e: list) {

   844             if (!foundParams.contains(e)) {

   845                 CharSequence paramName = (e.getKind() == ElementKind.TYPE_PARAMETER)

   846                         ? "<" + e.getSimpleName() + ">"

   847                         : e.getSimpleName();

   848                 reportMissing("dc.missing.param", paramName);

   849             }

   850         }

   851     }

   852 

   853     @Override @DefinedBy(Api.COMPILER_TREE)

   854     public Void visitProvides(ProvidesTree tree, Void ignore) {

   855         Element e = env.trees.getElement(env.currPath);

   856         if (e.getKind() != ElementKind.MODULE) {

   857             env.messages.error(REFERENCE, tree, "dc.invalid.provides");

   858         }

   859         ReferenceTree serviceType = tree.getServiceType();

   860         Element se = env.trees.getElement(new DocTreePath(getCurrentPath(), serviceType));

   861         if (se == null) {

   862             env.messages.error(REFERENCE, tree, "dc.service.not.found");

   863         }

   864         return super.visitProvides(tree, ignore);

   865     }

   866 

   867     @Override @DefinedBy(Api.COMPILER_TREE)

   868     public Void visitReference(ReferenceTree tree, Void ignore) {

   869         String sig = tree.getSignature();

   870         if (sig.contains("<") || sig.contains(">"))

   871             env.messages.error(REFERENCE, tree, "dc.type.arg.not.allowed");

   872 

   873         Element e = env.trees.getElement(getCurrentPath());

   874         if (e == null)

   875             env.messages.error(REFERENCE, tree, "dc.ref.not.found");

   876         return super.visitReference(tree, ignore);

   877     }

   878 

   879     @Override @DefinedBy(Api.COMPILER_TREE)

   880     public Void visitReturn(ReturnTree tree, Void ignore) {

   881         if (foundReturn) {

   882             env.messages.warning(REFERENCE, tree, "dc.exists.return");

   883         }

   884 

   885         Element e = env.trees.getElement(env.currPath);

   886         if (e.getKind() != ElementKind.METHOD

   887                 || ((ExecutableElement) e).getReturnType().getKind() == TypeKind.VOID)

   888             env.messages.error(REFERENCE, tree, "dc.invalid.return");

   889         foundReturn = true;

   890         warnIfEmpty(tree, tree.getDescription());

   891         return super.visitReturn(tree, ignore);

   892     }

   893 

   894     @Override @DefinedBy(Api.COMPILER_TREE)

   895     public Void visitSerialData(SerialDataTree tree, Void ignore) {

   896         warnIfEmpty(tree, tree.getDescription());

   897         return super.visitSerialData(tree, ignore);

   898     }

   899 

   900     @Override @DefinedBy(Api.COMPILER_TREE)

   901     public Void visitSerialField(SerialFieldTree tree, Void ignore) {

   902         warnIfEmpty(tree, tree.getDescription());

   903         return super.visitSerialField(tree, ignore);

   904     }

   905 

   906     @Override @DefinedBy(Api.COMPILER_TREE)

   907     public Void visitSince(SinceTree tree, Void ignore) {

   908         warnIfEmpty(tree, tree.getBody());

   909         return super.visitSince(tree, ignore);

   910     }

   911 

   912     @Override @DefinedBy(Api.COMPILER_TREE)

   913     public Void visitSummary(SummaryTree node, Void aVoid) {

   914         int idx = env.currDocComment.getFullBody().indexOf(node);

   915         // Warn if the node is preceded by non-whitespace characters,

   916         // or other non-text nodes.

   917         if ((idx == 1 && hasNonWhitespaceText) || idx > 1) {

   918             env.messages.warning(SYNTAX, node, "dc.invalid.summary", node.getTagName());

   919         }

   920         return super.visitSummary(node, aVoid);

   921     }

   922 

   923     @Override @DefinedBy(Api.COMPILER_TREE)

   924     public Void visitThrows(ThrowsTree tree, Void ignore) {

   925         ReferenceTree exName = tree.getExceptionName();

   926         Element ex = env.trees.getElement(new DocTreePath(getCurrentPath(), exName));

   927         if (ex == null) {

   928             env.messages.error(REFERENCE, tree, "dc.ref.not.found");

   929         } else if (isThrowable(ex.asType())) {

   930             switch (env.currElement.getKind()) {

   931                 case CONSTRUCTOR:

   932                 case METHOD:

   933                     if (isCheckedException(ex.asType())) {

   934                         ExecutableElement ee = (ExecutableElement) env.currElement;

   935                         checkThrowsDeclared(exName, ex.asType(), ee.getThrownTypes());

   936                     }

   937                     break;

   938                 default:

   939                     env.messages.error(REFERENCE, tree, "dc.invalid.throws");

   940             }

   941         } else {

   942             env.messages.error(REFERENCE, tree, "dc.invalid.throws");

   943         }

   944         warnIfEmpty(tree, tree.getDescription());

   945         return scan(tree.getDescription(), ignore);

   946     }

   947 

   948     private boolean isThrowable(TypeMirror tm) {

   949         switch (tm.getKind()) {

   950             case DECLARED:

   951             case TYPEVAR:

   952                 return env.types.isAssignable(tm, env.java_lang_Throwable);

   953         }

   954         return false;

   955     }

   956 

   957     private void checkThrowsDeclared(ReferenceTree tree, TypeMirror t, List<? extends TypeMirror> list) {

   958         boolean found = false;

   959         for (TypeMirror tl : list) {

   960             if (env.types.isAssignable(t, tl)) {

   961                 foundThrows.add(tl);

   962                 found = true;

   963             }

   964         }

   965         if (!found)

   966             env.messages.error(REFERENCE, tree, "dc.exception.not.thrown", t);

   967     }

   968 

   969     private void checkThrowsDocumented(List<? extends TypeMirror> list) {

   970         if (foundInheritDoc)

   971             return;

   972 

   973         for (TypeMirror tl: list) {

   974             if (isCheckedException(tl) && !foundThrows.contains(tl))

   975                 reportMissing("dc.missing.throws", tl);

   976         }

   977     }

   978 

   979     @Override @DefinedBy(Api.COMPILER_TREE)

   980     public Void visitUnknownBlockTag(UnknownBlockTagTree tree, Void ignore) {

   981         checkUnknownTag(tree, tree.getTagName());

   982         return super.visitUnknownBlockTag(tree, ignore);

   983     }

   984 

   985     @Override @DefinedBy(Api.COMPILER_TREE)

   986     public Void visitUnknownInlineTag(UnknownInlineTagTree tree, Void ignore) {

   987         checkUnknownTag(tree, tree.getTagName());

   988         return super.visitUnknownInlineTag(tree, ignore);

   989     }

   990 

   991     private void checkUnknownTag(DocTree tree, String tagName) {

   992         if (env.customTags != null && !env.customTags.contains(tagName))

   993             env.messages.error(SYNTAX, tree, "dc.tag.unknown", tagName);

   994     }

   995 

   996     @Override @DefinedBy(Api.COMPILER_TREE)

   997     public Void visitUses(UsesTree tree, Void ignore) {

   998         Element e = env.trees.getElement(env.currPath);

   999         if (e.getKind() != ElementKind.MODULE) {

  1000             env.messages.error(REFERENCE, tree, "dc.invalid.uses");

  1001         }

  1002         ReferenceTree serviceType = tree.getServiceType();

  1003         Element se = env.trees.getElement(new DocTreePath(getCurrentPath(), serviceType));

  1004         if (se == null) {

  1005             env.messages.error(REFERENCE, tree, "dc.service.not.found");

  1006         }

  1007         return super.visitUses(tree, ignore);

  1008     }

  1009 

  1010     @Override @DefinedBy(Api.COMPILER_TREE)

  1011     public Void visitValue(ValueTree tree, Void ignore) {

  1012         ReferenceTree ref = tree.getReference();

  1013         if (ref == null || ref.getSignature().isEmpty()) {

  1014             if (!isConstant(env.currElement))

  1015                 env.messages.error(REFERENCE, tree, "dc.value.not.allowed.here");

  1016         } else {

  1017             Element e = env.trees.getElement(new DocTreePath(getCurrentPath(), ref));

  1018             if (!isConstant(e))

  1019                 env.messages.error(REFERENCE, tree, "dc.value.not.a.constant");

  1020         }

  1021 

  1022         markEnclosingTag(Flag.HAS_INLINE_TAG);

  1023         return super.visitValue(tree, ignore);

  1024     }

  1025 

  1026     private boolean isConstant(Element e) {

  1027         if (e == null)

  1028             return false;

  1029 

  1030         switch (e.getKind()) {

  1031             case FIELD:

  1032                 Object value = ((VariableElement) e).getConstantValue();

  1033                 return (value != null); // can't distinguish "not a constant" from "constant is null"

  1034             default:

  1035                 return false;

  1036         }

  1037     }

  1038 

  1039     @Override @DefinedBy(Api.COMPILER_TREE)

  1040     public Void visitVersion(VersionTree tree, Void ignore) {

  1041         warnIfEmpty(tree, tree.getBody());

  1042         return super.visitVersion(tree, ignore);

  1043     }

  1044 

  1045     @Override @DefinedBy(Api.COMPILER_TREE)

  1046     public Void visitErroneous(ErroneousTree tree, Void ignore) {

  1047         env.messages.error(SYNTAX, tree, null, tree.getDiagnostic().getMessage(null));

  1048         return null;

  1049     }

  1050     // </editor-fold>

  1051 

  1052     // <editor-fold defaultstate="collapsed" desc="Utility methods">

  1053 

  1054     private boolean isCheckedException(TypeMirror t) {

  1055         return !(env.types.isAssignable(t, env.java_lang_Error)

  1056                 || env.types.isAssignable(t, env.java_lang_RuntimeException));

  1057     }

  1058 

  1059     private boolean isSynthetic() {

  1060         switch (env.currElement.getKind()) {

  1061             case CONSTRUCTOR:

  1062                 // A synthetic default constructor has the same pos as the

  1063                 // enclosing class

  1064                 TreePath p = env.currPath;

  1065                 return env.getPos(p) == env.getPos(p.getParentPath());

  1066         }

  1067         return false;

  1068     }

  1069 

  1070     void markEnclosingTag(Flag flag) {

  1071         TagStackItem top = tagStack.peek();

  1072         if (top != null)

  1073             top.flags.add(flag);

  1074     }

  1075 

  1076     String toString(TreePath p) {

  1077         StringBuilder sb = new StringBuilder("TreePath[");

  1078         toString(p, sb);

  1079         sb.append("]");

  1080         return sb.toString();

  1081     }

  1082 

  1083     void toString(TreePath p, StringBuilder sb) {

  1084         TreePath parent = p.getParentPath();

  1085         if (parent != null) {

  1086             toString(parent, sb);

  1087             sb.append(",");

  1088         }

  1089        sb.append(p.getLeaf().getKind()).append(":").append(env.getPos(p)).append(":S").append(env.getStartPos(p));

  1090     }

  1091 

  1092     void warnIfEmpty(DocTree tree, List<? extends DocTree> list) {

  1093         for (DocTree d: list) {

  1094             switch (d.getKind()) {

  1095                 case TEXT:

  1096                     if (hasNonWhitespace((TextTree) d))

  1097                         return;

  1098                     break;

  1099                 default:

  1100                     return;

  1101             }

  1102         }

  1103         env.messages.warning(SYNTAX, tree, "dc.empty", tree.getKind().tagName);

  1104     }

  1105 

  1106     boolean hasNonWhitespace(TextTree tree) {

  1107         String s = tree.getBody();

  1108         for (int i = 0; i < s.length(); i++) {

  1109             Character c = s.charAt(i);

  1110             if (!Character.isWhitespace(s.charAt(i)))

  1111                 return true;

  1112         }

  1113         return false;

  1114     }

  1115 

  1116     // </editor-fold>

  1117 

  1118 }