1 //===--- CommentSema.cpp - Doxygen comment semantic analysis --------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "clang/AST/CommentSema.h"
10 #include "clang/AST/Attr.h"
11 #include "clang/AST/CommentCommandTraits.h"
12 #include "clang/AST/CommentDiagnostic.h"
13 #include "clang/AST/Decl.h"
14 #include "clang/AST/DeclTemplate.h"
15 #include "clang/Basic/LLVM.h"
16 #include "clang/Basic/SourceManager.h"
17 #include "clang/Lex/Preprocessor.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/StringSwitch.h"
20 
21 namespace clang {
22 namespace comments {
23 
24 namespace {
25 #include "clang/AST/CommentHTMLTagsProperties.inc"
26 } // end anonymous namespace
27 
28 Sema::Sema(llvm::BumpPtrAllocator &Allocator, const SourceManager &SourceMgr,
29            DiagnosticsEngine &Diags, CommandTraits &Traits,
30            const Preprocessor *PP) :
31     Allocator(Allocator), SourceMgr(SourceMgr), Diags(Diags), Traits(Traits),
32     PP(PP), ThisDeclInfo(nullptr), BriefCommand(nullptr),
33     HeaderfileCommand(nullptr) {
34 }
35 
36 void Sema::setDecl(const Decl *D) {
37   if (!D)
38     return;
39 
40   ThisDeclInfo = new (Allocator) DeclInfo;
41   ThisDeclInfo->CommentDecl = D;
42   ThisDeclInfo->IsFilled = false;
43 }
44 
45 ParagraphComment *Sema::actOnParagraphComment(
46                               ArrayRef<InlineContentComment *> Content) {
47   return new (Allocator) ParagraphComment(Content);
48 }
49 
50 BlockCommandComment *Sema::actOnBlockCommandStart(
51                                       SourceLocation LocBegin,
52                                       SourceLocation LocEnd,
53                                       unsigned CommandID,
54                                       CommandMarkerKind CommandMarker) {
55   BlockCommandComment *BC = new (Allocator) BlockCommandComment(LocBegin, LocEnd,
56                                                                 CommandID,
57                                                                 CommandMarker);
58   checkContainerDecl(BC);
59   return BC;
60 }
61 
62 void Sema::actOnBlockCommandArgs(BlockCommandComment *Command,
63                                  ArrayRef<BlockCommandComment::Argument> Args) {
64   Command->setArgs(Args);
65 }
66 
67 void Sema::actOnBlockCommandFinish(BlockCommandComment *Command,
68                                    ParagraphComment *Paragraph) {
69   Command->setParagraph(Paragraph);
70   checkBlockCommandEmptyParagraph(Command);
71   checkBlockCommandDuplicate(Command);
72   if (ThisDeclInfo) {
73     // These checks only make sense if the comment is attached to a
74     // declaration.
75     checkReturnsCommand(Command);
76     checkDeprecatedCommand(Command);
77   }
78 }
79 
80 ParamCommandComment *Sema::actOnParamCommandStart(
81                                       SourceLocation LocBegin,
82                                       SourceLocation LocEnd,
83                                       unsigned CommandID,
84                                       CommandMarkerKind CommandMarker) {
85   ParamCommandComment *Command =
86       new (Allocator) ParamCommandComment(LocBegin, LocEnd, CommandID,
87                                           CommandMarker);
88 
89   if (!involvesFunctionType())
90     Diag(Command->getLocation(),
91          diag::warn_doc_param_not_attached_to_a_function_decl)
92       << CommandMarker
93       << Command->getCommandNameRange(Traits);
94 
95   return Command;
96 }
97 
98 void Sema::checkFunctionDeclVerbatimLine(const BlockCommandComment *Comment) {
99   const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
100   if (!Info->IsFunctionDeclarationCommand)
101     return;
102 
103   unsigned DiagSelect;
104   switch (Comment->getCommandID()) {
105     case CommandTraits::KCI_function:
106       DiagSelect = (!isAnyFunctionDecl() && !isFunctionTemplateDecl())? 1 : 0;
107       break;
108     case CommandTraits::KCI_functiongroup:
109       DiagSelect = (!isAnyFunctionDecl() && !isFunctionTemplateDecl())? 2 : 0;
110       break;
111     case CommandTraits::KCI_method:
112       DiagSelect = !isObjCMethodDecl() ? 3 : 0;
113       break;
114     case CommandTraits::KCI_methodgroup:
115       DiagSelect = !isObjCMethodDecl() ? 4 : 0;
116       break;
117     case CommandTraits::KCI_callback:
118       DiagSelect = !isFunctionPointerVarDecl() ? 5 : 0;
119       break;
120     default:
121       DiagSelect = 0;
122       break;
123   }
124   if (DiagSelect)
125     Diag(Comment->getLocation(), diag::warn_doc_function_method_decl_mismatch)
126     << Comment->getCommandMarker()
127     << (DiagSelect-1) << (DiagSelect-1)
128     << Comment->getSourceRange();
129 }
130 
131 void Sema::checkContainerDeclVerbatimLine(const BlockCommandComment *Comment) {
132   const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
133   if (!Info->IsRecordLikeDeclarationCommand)
134     return;
135   unsigned DiagSelect;
136   switch (Comment->getCommandID()) {
137     case CommandTraits::KCI_class:
138       DiagSelect =
139           (!isClassOrStructOrTagTypedefDecl() && !isClassTemplateDecl()) ? 1
140                                                                          : 0;
141       // Allow @class command on @interface declarations.
142       // FIXME. Currently, \class and @class are indistinguishable. So,
143       // \class is also allowed on an @interface declaration
144       if (DiagSelect && Comment->getCommandMarker() && isObjCInterfaceDecl())
145         DiagSelect = 0;
146       break;
147     case CommandTraits::KCI_interface:
148       DiagSelect = !isObjCInterfaceDecl() ? 2 : 0;
149       break;
150     case CommandTraits::KCI_protocol:
151       DiagSelect = !isObjCProtocolDecl() ? 3 : 0;
152       break;
153     case CommandTraits::KCI_struct:
154       DiagSelect = !isClassOrStructOrTagTypedefDecl() ? 4 : 0;
155       break;
156     case CommandTraits::KCI_union:
157       DiagSelect = !isUnionDecl() ? 5 : 0;
158       break;
159     default:
160       DiagSelect = 0;
161       break;
162   }
163   if (DiagSelect)
164     Diag(Comment->getLocation(), diag::warn_doc_api_container_decl_mismatch)
165     << Comment->getCommandMarker()
166     << (DiagSelect-1) << (DiagSelect-1)
167     << Comment->getSourceRange();
168 }
169 
170 void Sema::checkContainerDecl(const BlockCommandComment *Comment) {
171   const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
172   if (!Info->IsRecordLikeDetailCommand || isRecordLikeDecl())
173     return;
174   unsigned DiagSelect;
175   switch (Comment->getCommandID()) {
176     case CommandTraits::KCI_classdesign:
177       DiagSelect = 1;
178       break;
179     case CommandTraits::KCI_coclass:
180       DiagSelect = 2;
181       break;
182     case CommandTraits::KCI_dependency:
183       DiagSelect = 3;
184       break;
185     case CommandTraits::KCI_helper:
186       DiagSelect = 4;
187       break;
188     case CommandTraits::KCI_helperclass:
189       DiagSelect = 5;
190       break;
191     case CommandTraits::KCI_helps:
192       DiagSelect = 6;
193       break;
194     case CommandTraits::KCI_instancesize:
195       DiagSelect = 7;
196       break;
197     case CommandTraits::KCI_ownership:
198       DiagSelect = 8;
199       break;
200     case CommandTraits::KCI_performance:
201       DiagSelect = 9;
202       break;
203     case CommandTraits::KCI_security:
204       DiagSelect = 10;
205       break;
206     case CommandTraits::KCI_superclass:
207       DiagSelect = 11;
208       break;
209     default:
210       DiagSelect = 0;
211       break;
212   }
213   if (DiagSelect)
214     Diag(Comment->getLocation(), diag::warn_doc_container_decl_mismatch)
215     << Comment->getCommandMarker()
216     << (DiagSelect-1)
217     << Comment->getSourceRange();
218 }
219 
220 /// Turn a string into the corresponding PassDirection or -1 if it's not
221 /// valid.
222 static int getParamPassDirection(StringRef Arg) {
223   return llvm::StringSwitch<int>(Arg)
224       .Case("[in]", ParamCommandComment::In)
225       .Case("[out]", ParamCommandComment::Out)
226       .Cases("[in,out]", "[out,in]", ParamCommandComment::InOut)
227       .Default(-1);
228 }
229 
230 void Sema::actOnParamCommandDirectionArg(ParamCommandComment *Command,
231                                          SourceLocation ArgLocBegin,
232                                          SourceLocation ArgLocEnd,
233                                          StringRef Arg) {
234   std::string ArgLower = Arg.lower();
235   int Direction = getParamPassDirection(ArgLower);
236 
237   if (Direction == -1) {
238     // Try again with whitespace removed.
239     llvm::erase_if(ArgLower, clang::isWhitespace);
240     Direction = getParamPassDirection(ArgLower);
241 
242     SourceRange ArgRange(ArgLocBegin, ArgLocEnd);
243     if (Direction != -1) {
244       const char *FixedName = ParamCommandComment::getDirectionAsString(
245           (ParamCommandComment::PassDirection)Direction);
246       Diag(ArgLocBegin, diag::warn_doc_param_spaces_in_direction)
247           << ArgRange << FixItHint::CreateReplacement(ArgRange, FixedName);
248     } else {
249       Diag(ArgLocBegin, diag::warn_doc_param_invalid_direction) << ArgRange;
250       Direction = ParamCommandComment::In; // Sane fall back.
251     }
252   }
253   Command->setDirection((ParamCommandComment::PassDirection)Direction,
254                         /*Explicit=*/true);
255 }
256 
257 void Sema::actOnParamCommandParamNameArg(ParamCommandComment *Command,
258                                          SourceLocation ArgLocBegin,
259                                          SourceLocation ArgLocEnd,
260                                          StringRef Arg) {
261   // Parser will not feed us more arguments than needed.
262   assert(Command->getNumArgs() == 0);
263 
264   if (!Command->isDirectionExplicit()) {
265     // User didn't provide a direction argument.
266     Command->setDirection(ParamCommandComment::In, /* Explicit = */ false);
267   }
268   auto *A = new (Allocator)
269       Comment::Argument{SourceRange(ArgLocBegin, ArgLocEnd), Arg};
270   Command->setArgs(llvm::ArrayRef(A, 1));
271 }
272 
273 void Sema::actOnParamCommandFinish(ParamCommandComment *Command,
274                                    ParagraphComment *Paragraph) {
275   Command->setParagraph(Paragraph);
276   checkBlockCommandEmptyParagraph(Command);
277 }
278 
279 TParamCommandComment *Sema::actOnTParamCommandStart(
280                                       SourceLocation LocBegin,
281                                       SourceLocation LocEnd,
282                                       unsigned CommandID,
283                                       CommandMarkerKind CommandMarker) {
284   TParamCommandComment *Command =
285       new (Allocator) TParamCommandComment(LocBegin, LocEnd, CommandID,
286                                            CommandMarker);
287 
288   if (!isTemplateOrSpecialization())
289     Diag(Command->getLocation(),
290          diag::warn_doc_tparam_not_attached_to_a_template_decl)
291       << CommandMarker
292       << Command->getCommandNameRange(Traits);
293 
294   return Command;
295 }
296 
297 void Sema::actOnTParamCommandParamNameArg(TParamCommandComment *Command,
298                                           SourceLocation ArgLocBegin,
299                                           SourceLocation ArgLocEnd,
300                                           StringRef Arg) {
301   // Parser will not feed us more arguments than needed.
302   assert(Command->getNumArgs() == 0);
303 
304   auto *A = new (Allocator)
305       Comment::Argument{SourceRange(ArgLocBegin, ArgLocEnd), Arg};
306   Command->setArgs(llvm::ArrayRef(A, 1));
307 
308   if (!isTemplateOrSpecialization()) {
309     // We already warned that this \\tparam is not attached to a template decl.
310     return;
311   }
312 
313   const TemplateParameterList *TemplateParameters =
314       ThisDeclInfo->TemplateParameters;
315   SmallVector<unsigned, 2> Position;
316   if (resolveTParamReference(Arg, TemplateParameters, &Position)) {
317     Command->setPosition(copyArray(llvm::ArrayRef(Position)));
318     TParamCommandComment *&PrevCommand = TemplateParameterDocs[Arg];
319     if (PrevCommand) {
320       SourceRange ArgRange(ArgLocBegin, ArgLocEnd);
321       Diag(ArgLocBegin, diag::warn_doc_tparam_duplicate)
322         << Arg << ArgRange;
323       Diag(PrevCommand->getLocation(), diag::note_doc_tparam_previous)
324         << PrevCommand->getParamNameRange();
325     }
326     PrevCommand = Command;
327     return;
328   }
329 
330   SourceRange ArgRange(ArgLocBegin, ArgLocEnd);
331   Diag(ArgLocBegin, diag::warn_doc_tparam_not_found)
332     << Arg << ArgRange;
333 
334   if (!TemplateParameters || TemplateParameters->size() == 0)
335     return;
336 
337   StringRef CorrectedName;
338   if (TemplateParameters->size() == 1) {
339     const NamedDecl *Param = TemplateParameters->getParam(0);
340     const IdentifierInfo *II = Param->getIdentifier();
341     if (II)
342       CorrectedName = II->getName();
343   } else {
344     CorrectedName = correctTypoInTParamReference(Arg, TemplateParameters);
345   }
346 
347   if (!CorrectedName.empty()) {
348     Diag(ArgLocBegin, diag::note_doc_tparam_name_suggestion)
349       << CorrectedName
350       << FixItHint::CreateReplacement(ArgRange, CorrectedName);
351   }
352 }
353 
354 void Sema::actOnTParamCommandFinish(TParamCommandComment *Command,
355                                     ParagraphComment *Paragraph) {
356   Command->setParagraph(Paragraph);
357   checkBlockCommandEmptyParagraph(Command);
358 }
359 
360 InlineCommandComment *
361 Sema::actOnInlineCommand(SourceLocation CommandLocBegin,
362                          SourceLocation CommandLocEnd, unsigned CommandID,
363                          ArrayRef<Comment::Argument> Args) {
364   StringRef CommandName = Traits.getCommandInfo(CommandID)->Name;
365 
366   return new (Allocator)
367       InlineCommandComment(CommandLocBegin, CommandLocEnd, CommandID,
368                            getInlineCommandRenderKind(CommandName), Args);
369 }
370 
371 InlineContentComment *Sema::actOnUnknownCommand(SourceLocation LocBegin,
372                                                 SourceLocation LocEnd,
373                                                 StringRef CommandName) {
374   unsigned CommandID = Traits.registerUnknownCommand(CommandName)->getID();
375   return actOnUnknownCommand(LocBegin, LocEnd, CommandID);
376 }
377 
378 InlineContentComment *Sema::actOnUnknownCommand(SourceLocation LocBegin,
379                                                 SourceLocation LocEnd,
380                                                 unsigned CommandID) {
381   ArrayRef<InlineCommandComment::Argument> Args;
382   return new (Allocator) InlineCommandComment(
383                                   LocBegin, LocEnd, CommandID,
384                                   InlineCommandComment::RenderNormal,
385                                   Args);
386 }
387 
388 TextComment *Sema::actOnText(SourceLocation LocBegin,
389                              SourceLocation LocEnd,
390                              StringRef Text) {
391   return new (Allocator) TextComment(LocBegin, LocEnd, Text);
392 }
393 
394 VerbatimBlockComment *Sema::actOnVerbatimBlockStart(SourceLocation Loc,
395                                                     unsigned CommandID) {
396   StringRef CommandName = Traits.getCommandInfo(CommandID)->Name;
397   return new (Allocator) VerbatimBlockComment(
398                                   Loc,
399                                   Loc.getLocWithOffset(1 + CommandName.size()),
400                                   CommandID);
401 }
402 
403 VerbatimBlockLineComment *Sema::actOnVerbatimBlockLine(SourceLocation Loc,
404                                                        StringRef Text) {
405   return new (Allocator) VerbatimBlockLineComment(Loc, Text);
406 }
407 
408 void Sema::actOnVerbatimBlockFinish(
409                             VerbatimBlockComment *Block,
410                             SourceLocation CloseNameLocBegin,
411                             StringRef CloseName,
412                             ArrayRef<VerbatimBlockLineComment *> Lines) {
413   Block->setCloseName(CloseName, CloseNameLocBegin);
414   Block->setLines(Lines);
415 }
416 
417 VerbatimLineComment *Sema::actOnVerbatimLine(SourceLocation LocBegin,
418                                              unsigned CommandID,
419                                              SourceLocation TextBegin,
420                                              StringRef Text) {
421   VerbatimLineComment *VL = new (Allocator) VerbatimLineComment(
422                               LocBegin,
423                               TextBegin.getLocWithOffset(Text.size()),
424                               CommandID,
425                               TextBegin,
426                               Text);
427   checkFunctionDeclVerbatimLine(VL);
428   checkContainerDeclVerbatimLine(VL);
429   return VL;
430 }
431 
432 HTMLStartTagComment *Sema::actOnHTMLStartTagStart(SourceLocation LocBegin,
433                                                   StringRef TagName) {
434   return new (Allocator) HTMLStartTagComment(LocBegin, TagName);
435 }
436 
437 void Sema::actOnHTMLStartTagFinish(
438                               HTMLStartTagComment *Tag,
439                               ArrayRef<HTMLStartTagComment::Attribute> Attrs,
440                               SourceLocation GreaterLoc,
441                               bool IsSelfClosing) {
442   Tag->setAttrs(Attrs);
443   Tag->setGreaterLoc(GreaterLoc);
444   if (IsSelfClosing)
445     Tag->setSelfClosing();
446   else if (!isHTMLEndTagForbidden(Tag->getTagName()))
447     HTMLOpenTags.push_back(Tag);
448 }
449 
450 HTMLEndTagComment *Sema::actOnHTMLEndTag(SourceLocation LocBegin,
451                                          SourceLocation LocEnd,
452                                          StringRef TagName) {
453   HTMLEndTagComment *HET =
454       new (Allocator) HTMLEndTagComment(LocBegin, LocEnd, TagName);
455   if (isHTMLEndTagForbidden(TagName)) {
456     Diag(HET->getLocation(), diag::warn_doc_html_end_forbidden)
457       << TagName << HET->getSourceRange();
458     HET->setIsMalformed();
459     return HET;
460   }
461 
462   bool FoundOpen = false;
463   for (SmallVectorImpl<HTMLStartTagComment *>::const_reverse_iterator
464        I = HTMLOpenTags.rbegin(), E = HTMLOpenTags.rend();
465        I != E; ++I) {
466     if ((*I)->getTagName() == TagName) {
467       FoundOpen = true;
468       break;
469     }
470   }
471   if (!FoundOpen) {
472     Diag(HET->getLocation(), diag::warn_doc_html_end_unbalanced)
473       << HET->getSourceRange();
474     HET->setIsMalformed();
475     return HET;
476   }
477 
478   while (!HTMLOpenTags.empty()) {
479     HTMLStartTagComment *HST = HTMLOpenTags.pop_back_val();
480     StringRef LastNotClosedTagName = HST->getTagName();
481     if (LastNotClosedTagName == TagName) {
482       // If the start tag is malformed, end tag is malformed as well.
483       if (HST->isMalformed())
484         HET->setIsMalformed();
485       break;
486     }
487 
488     if (isHTMLEndTagOptional(LastNotClosedTagName))
489       continue;
490 
491     bool OpenLineInvalid;
492     const unsigned OpenLine = SourceMgr.getPresumedLineNumber(
493                                                 HST->getLocation(),
494                                                 &OpenLineInvalid);
495     bool CloseLineInvalid;
496     const unsigned CloseLine = SourceMgr.getPresumedLineNumber(
497                                                 HET->getLocation(),
498                                                 &CloseLineInvalid);
499 
500     if (OpenLineInvalid || CloseLineInvalid || OpenLine == CloseLine) {
501       Diag(HST->getLocation(), diag::warn_doc_html_start_end_mismatch)
502         << HST->getTagName() << HET->getTagName()
503         << HST->getSourceRange() << HET->getSourceRange();
504       HST->setIsMalformed();
505     } else {
506       Diag(HST->getLocation(), diag::warn_doc_html_start_end_mismatch)
507         << HST->getTagName() << HET->getTagName()
508         << HST->getSourceRange();
509       Diag(HET->getLocation(), diag::note_doc_html_end_tag)
510         << HET->getSourceRange();
511       HST->setIsMalformed();
512     }
513   }
514 
515   return HET;
516 }
517 
518 FullComment *Sema::actOnFullComment(
519                               ArrayRef<BlockContentComment *> Blocks) {
520   FullComment *FC = new (Allocator) FullComment(Blocks, ThisDeclInfo);
521   resolveParamCommandIndexes(FC);
522 
523   // Complain about HTML tags that are not closed.
524   while (!HTMLOpenTags.empty()) {
525     HTMLStartTagComment *HST = HTMLOpenTags.pop_back_val();
526     if (isHTMLEndTagOptional(HST->getTagName()))
527       continue;
528 
529     Diag(HST->getLocation(), diag::warn_doc_html_missing_end_tag)
530       << HST->getTagName() << HST->getSourceRange();
531     HST->setIsMalformed();
532   }
533 
534   return FC;
535 }
536 
537 void Sema::checkBlockCommandEmptyParagraph(BlockCommandComment *Command) {
538   if (Traits.getCommandInfo(Command->getCommandID())->IsEmptyParagraphAllowed)
539     return;
540 
541   ParagraphComment *Paragraph = Command->getParagraph();
542   if (Paragraph->isWhitespace()) {
543     SourceLocation DiagLoc;
544     if (Command->getNumArgs() > 0)
545       DiagLoc = Command->getArgRange(Command->getNumArgs() - 1).getEnd();
546     if (!DiagLoc.isValid())
547       DiagLoc = Command->getCommandNameRange(Traits).getEnd();
548     Diag(DiagLoc, diag::warn_doc_block_command_empty_paragraph)
549       << Command->getCommandMarker()
550       << Command->getCommandName(Traits)
551       << Command->getSourceRange();
552   }
553 }
554 
555 void Sema::checkReturnsCommand(const BlockCommandComment *Command) {
556   if (!Traits.getCommandInfo(Command->getCommandID())->IsReturnsCommand)
557     return;
558 
559   assert(ThisDeclInfo && "should not call this check on a bare comment");
560 
561   // We allow the return command for all @properties because it can be used
562   // to document the value that the property getter returns.
563   if (isObjCPropertyDecl())
564     return;
565   if (involvesFunctionType()) {
566     assert(!ThisDeclInfo->ReturnType.isNull() &&
567            "should have a valid return type");
568     if (ThisDeclInfo->ReturnType->isVoidType()) {
569       unsigned DiagKind;
570       switch (ThisDeclInfo->CommentDecl->getKind()) {
571       default:
572         if (ThisDeclInfo->IsObjCMethod)
573           DiagKind = 3;
574         else
575           DiagKind = 0;
576         break;
577       case Decl::CXXConstructor:
578         DiagKind = 1;
579         break;
580       case Decl::CXXDestructor:
581         DiagKind = 2;
582         break;
583       }
584       Diag(Command->getLocation(),
585            diag::warn_doc_returns_attached_to_a_void_function)
586         << Command->getCommandMarker()
587         << Command->getCommandName(Traits)
588         << DiagKind
589         << Command->getSourceRange();
590     }
591     return;
592   }
593 
594   Diag(Command->getLocation(),
595        diag::warn_doc_returns_not_attached_to_a_function_decl)
596     << Command->getCommandMarker()
597     << Command->getCommandName(Traits)
598     << Command->getSourceRange();
599 }
600 
601 void Sema::checkBlockCommandDuplicate(const BlockCommandComment *Command) {
602   const CommandInfo *Info = Traits.getCommandInfo(Command->getCommandID());
603   const BlockCommandComment *PrevCommand = nullptr;
604   if (Info->IsBriefCommand) {
605     if (!BriefCommand) {
606       BriefCommand = Command;
607       return;
608     }
609     PrevCommand = BriefCommand;
610   } else if (Info->IsHeaderfileCommand) {
611     if (!HeaderfileCommand) {
612       HeaderfileCommand = Command;
613       return;
614     }
615     PrevCommand = HeaderfileCommand;
616   } else {
617     // We don't want to check this command for duplicates.
618     return;
619   }
620   StringRef CommandName = Command->getCommandName(Traits);
621   StringRef PrevCommandName = PrevCommand->getCommandName(Traits);
622   Diag(Command->getLocation(), diag::warn_doc_block_command_duplicate)
623       << Command->getCommandMarker()
624       << CommandName
625       << Command->getSourceRange();
626   if (CommandName == PrevCommandName)
627     Diag(PrevCommand->getLocation(), diag::note_doc_block_command_previous)
628         << PrevCommand->getCommandMarker()
629         << PrevCommandName
630         << PrevCommand->getSourceRange();
631   else
632     Diag(PrevCommand->getLocation(),
633          diag::note_doc_block_command_previous_alias)
634         << PrevCommand->getCommandMarker()
635         << PrevCommandName
636         << CommandName;
637 }
638 
639 void Sema::checkDeprecatedCommand(const BlockCommandComment *Command) {
640   if (!Traits.getCommandInfo(Command->getCommandID())->IsDeprecatedCommand)
641     return;
642 
643   assert(ThisDeclInfo && "should not call this check on a bare comment");
644 
645   const Decl *D = ThisDeclInfo->CommentDecl;
646   if (!D)
647     return;
648 
649   if (D->hasAttr<DeprecatedAttr>() ||
650       D->hasAttr<AvailabilityAttr>() ||
651       D->hasAttr<UnavailableAttr>())
652     return;
653 
654   Diag(Command->getLocation(), diag::warn_doc_deprecated_not_sync)
655       << Command->getSourceRange() << Command->getCommandMarker();
656 
657   // Try to emit a fixit with a deprecation attribute.
658   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
659     // Don't emit a Fix-It for non-member function definitions.  GCC does not
660     // accept attributes on them.
661     const DeclContext *Ctx = FD->getDeclContext();
662     if ((!Ctx || !Ctx->isRecord()) &&
663         FD->doesThisDeclarationHaveABody())
664       return;
665 
666     const LangOptions &LO = FD->getLangOpts();
667     const bool DoubleSquareBracket = LO.CPlusPlus14 || LO.C2x;
668     StringRef AttributeSpelling =
669         DoubleSquareBracket ? "[[deprecated]]" : "__attribute__((deprecated))";
670     if (PP) {
671       // Try to find a replacement macro:
672       // - In C2x/C++14 we prefer [[deprecated]].
673       // - If not found or an older C/C++ look for __attribute__((deprecated)).
674       StringRef MacroName;
675       if (DoubleSquareBracket) {
676         TokenValue Tokens[] = {tok::l_square, tok::l_square,
677                                PP->getIdentifierInfo("deprecated"),
678                                tok::r_square, tok::r_square};
679         MacroName = PP->getLastMacroWithSpelling(FD->getLocation(), Tokens);
680         if (!MacroName.empty())
681           AttributeSpelling = MacroName;
682       }
683 
684       if (MacroName.empty()) {
685         TokenValue Tokens[] = {
686             tok::kw___attribute, tok::l_paren,
687             tok::l_paren,        PP->getIdentifierInfo("deprecated"),
688             tok::r_paren,        tok::r_paren};
689         StringRef MacroName =
690             PP->getLastMacroWithSpelling(FD->getLocation(), Tokens);
691         if (!MacroName.empty())
692           AttributeSpelling = MacroName;
693       }
694     }
695 
696     SmallString<64> TextToInsert = AttributeSpelling;
697     TextToInsert += " ";
698     SourceLocation Loc = FD->getSourceRange().getBegin();
699     Diag(Loc, diag::note_add_deprecation_attr)
700         << FixItHint::CreateInsertion(Loc, TextToInsert);
701   }
702 }
703 
704 void Sema::resolveParamCommandIndexes(const FullComment *FC) {
705   if (!involvesFunctionType()) {
706     // We already warned that \\param commands are not attached to a function
707     // decl.
708     return;
709   }
710 
711   SmallVector<ParamCommandComment *, 8> UnresolvedParamCommands;
712 
713   // Comment AST nodes that correspond to \c ParamVars for which we have
714   // found a \\param command or NULL if no documentation was found so far.
715   SmallVector<ParamCommandComment *, 8> ParamVarDocs;
716 
717   ArrayRef<const ParmVarDecl *> ParamVars = getParamVars();
718   ParamVarDocs.resize(ParamVars.size(), nullptr);
719 
720   // First pass over all \\param commands: resolve all parameter names.
721   for (Comment::child_iterator I = FC->child_begin(), E = FC->child_end();
722        I != E; ++I) {
723     ParamCommandComment *PCC = dyn_cast<ParamCommandComment>(*I);
724     if (!PCC || !PCC->hasParamName())
725       continue;
726     StringRef ParamName = PCC->getParamNameAsWritten();
727 
728     // Check that referenced parameter name is in the function decl.
729     const unsigned ResolvedParamIndex = resolveParmVarReference(ParamName,
730                                                                 ParamVars);
731     if (ResolvedParamIndex == ParamCommandComment::VarArgParamIndex) {
732       PCC->setIsVarArgParam();
733       continue;
734     }
735     if (ResolvedParamIndex == ParamCommandComment::InvalidParamIndex) {
736       UnresolvedParamCommands.push_back(PCC);
737       continue;
738     }
739     PCC->setParamIndex(ResolvedParamIndex);
740     if (ParamVarDocs[ResolvedParamIndex]) {
741       SourceRange ArgRange = PCC->getParamNameRange();
742       Diag(ArgRange.getBegin(), diag::warn_doc_param_duplicate)
743         << ParamName << ArgRange;
744       ParamCommandComment *PrevCommand = ParamVarDocs[ResolvedParamIndex];
745       Diag(PrevCommand->getLocation(), diag::note_doc_param_previous)
746         << PrevCommand->getParamNameRange();
747     }
748     ParamVarDocs[ResolvedParamIndex] = PCC;
749   }
750 
751   // Find parameter declarations that have no corresponding \\param.
752   SmallVector<const ParmVarDecl *, 8> OrphanedParamDecls;
753   for (unsigned i = 0, e = ParamVarDocs.size(); i != e; ++i) {
754     if (!ParamVarDocs[i])
755       OrphanedParamDecls.push_back(ParamVars[i]);
756   }
757 
758   // Second pass over unresolved \\param commands: do typo correction.
759   // Suggest corrections from a set of parameter declarations that have no
760   // corresponding \\param.
761   for (unsigned i = 0, e = UnresolvedParamCommands.size(); i != e; ++i) {
762     const ParamCommandComment *PCC = UnresolvedParamCommands[i];
763 
764     SourceRange ArgRange = PCC->getParamNameRange();
765     StringRef ParamName = PCC->getParamNameAsWritten();
766     Diag(ArgRange.getBegin(), diag::warn_doc_param_not_found)
767       << ParamName << ArgRange;
768 
769     // All parameters documented -- can't suggest a correction.
770     if (OrphanedParamDecls.size() == 0)
771       continue;
772 
773     unsigned CorrectedParamIndex = ParamCommandComment::InvalidParamIndex;
774     if (OrphanedParamDecls.size() == 1) {
775       // If one parameter is not documented then that parameter is the only
776       // possible suggestion.
777       CorrectedParamIndex = 0;
778     } else {
779       // Do typo correction.
780       CorrectedParamIndex = correctTypoInParmVarReference(ParamName,
781                                                           OrphanedParamDecls);
782     }
783     if (CorrectedParamIndex != ParamCommandComment::InvalidParamIndex) {
784       const ParmVarDecl *CorrectedPVD = OrphanedParamDecls[CorrectedParamIndex];
785       if (const IdentifierInfo *CorrectedII = CorrectedPVD->getIdentifier())
786         Diag(ArgRange.getBegin(), diag::note_doc_param_name_suggestion)
787           << CorrectedII->getName()
788           << FixItHint::CreateReplacement(ArgRange, CorrectedII->getName());
789     }
790   }
791 }
792 
793 bool Sema::involvesFunctionType() {
794   if (!ThisDeclInfo)
795     return false;
796   if (!ThisDeclInfo->IsFilled)
797     inspectThisDecl();
798   return ThisDeclInfo->involvesFunctionType();
799 }
800 
801 bool Sema::isFunctionDecl() {
802   if (!ThisDeclInfo)
803     return false;
804   if (!ThisDeclInfo->IsFilled)
805     inspectThisDecl();
806   return ThisDeclInfo->getKind() == DeclInfo::FunctionKind;
807 }
808 
809 bool Sema::isAnyFunctionDecl() {
810   return isFunctionDecl() && ThisDeclInfo->CurrentDecl &&
811          isa<FunctionDecl>(ThisDeclInfo->CurrentDecl);
812 }
813 
814 bool Sema::isFunctionOrMethodVariadic() {
815   if (!ThisDeclInfo)
816     return false;
817   if (!ThisDeclInfo->IsFilled)
818     inspectThisDecl();
819   return ThisDeclInfo->IsVariadic;
820 }
821 
822 bool Sema::isObjCMethodDecl() {
823   return isFunctionDecl() && ThisDeclInfo->CurrentDecl &&
824          isa<ObjCMethodDecl>(ThisDeclInfo->CurrentDecl);
825 }
826 
827 bool Sema::isFunctionPointerVarDecl() {
828   if (!ThisDeclInfo)
829     return false;
830   if (!ThisDeclInfo->IsFilled)
831     inspectThisDecl();
832   if (ThisDeclInfo->getKind() == DeclInfo::VariableKind) {
833     if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(ThisDeclInfo->CurrentDecl)) {
834       QualType QT = VD->getType();
835       return QT->isFunctionPointerType();
836     }
837   }
838   return false;
839 }
840 
841 bool Sema::isObjCPropertyDecl() {
842   if (!ThisDeclInfo)
843     return false;
844   if (!ThisDeclInfo->IsFilled)
845     inspectThisDecl();
846   return ThisDeclInfo->CurrentDecl->getKind() == Decl::ObjCProperty;
847 }
848 
849 bool Sema::isTemplateOrSpecialization() {
850   if (!ThisDeclInfo)
851     return false;
852   if (!ThisDeclInfo->IsFilled)
853     inspectThisDecl();
854   return ThisDeclInfo->getTemplateKind() != DeclInfo::NotTemplate;
855 }
856 
857 bool Sema::isRecordLikeDecl() {
858   if (!ThisDeclInfo)
859     return false;
860   if (!ThisDeclInfo->IsFilled)
861     inspectThisDecl();
862   return isUnionDecl() || isClassOrStructDecl() || isObjCInterfaceDecl() ||
863          isObjCProtocolDecl();
864 }
865 
866 bool Sema::isUnionDecl() {
867   if (!ThisDeclInfo)
868     return false;
869   if (!ThisDeclInfo->IsFilled)
870     inspectThisDecl();
871   if (const RecordDecl *RD =
872         dyn_cast_or_null<RecordDecl>(ThisDeclInfo->CurrentDecl))
873     return RD->isUnion();
874   return false;
875 }
876 static bool isClassOrStructDeclImpl(const Decl *D) {
877   if (auto *record = dyn_cast_or_null<RecordDecl>(D))
878     return !record->isUnion();
879 
880   return false;
881 }
882 
883 bool Sema::isClassOrStructDecl() {
884   if (!ThisDeclInfo)
885     return false;
886   if (!ThisDeclInfo->IsFilled)
887     inspectThisDecl();
888 
889   if (!ThisDeclInfo->CurrentDecl)
890     return false;
891 
892   return isClassOrStructDeclImpl(ThisDeclInfo->CurrentDecl);
893 }
894 
895 bool Sema::isClassOrStructOrTagTypedefDecl() {
896   if (!ThisDeclInfo)
897     return false;
898   if (!ThisDeclInfo->IsFilled)
899     inspectThisDecl();
900 
901   if (!ThisDeclInfo->CurrentDecl)
902     return false;
903 
904   if (isClassOrStructDeclImpl(ThisDeclInfo->CurrentDecl))
905     return true;
906 
907   if (auto *ThisTypedefDecl = dyn_cast<TypedefDecl>(ThisDeclInfo->CurrentDecl)) {
908     auto UnderlyingType = ThisTypedefDecl->getUnderlyingType();
909     if (auto ThisElaboratedType = dyn_cast<ElaboratedType>(UnderlyingType)) {
910       auto DesugaredType = ThisElaboratedType->desugar();
911       if (auto *DesugaredTypePtr = DesugaredType.getTypePtrOrNull()) {
912         if (auto *ThisRecordType = dyn_cast<RecordType>(DesugaredTypePtr)) {
913           return isClassOrStructDeclImpl(ThisRecordType->getAsRecordDecl());
914         }
915       }
916     }
917   }
918 
919   return false;
920 }
921 
922 bool Sema::isClassTemplateDecl() {
923   if (!ThisDeclInfo)
924     return false;
925   if (!ThisDeclInfo->IsFilled)
926     inspectThisDecl();
927   return ThisDeclInfo->CurrentDecl &&
928           (isa<ClassTemplateDecl>(ThisDeclInfo->CurrentDecl));
929 }
930 
931 bool Sema::isFunctionTemplateDecl() {
932   if (!ThisDeclInfo)
933     return false;
934   if (!ThisDeclInfo->IsFilled)
935     inspectThisDecl();
936   return ThisDeclInfo->CurrentDecl &&
937          (isa<FunctionTemplateDecl>(ThisDeclInfo->CurrentDecl));
938 }
939 
940 bool Sema::isObjCInterfaceDecl() {
941   if (!ThisDeclInfo)
942     return false;
943   if (!ThisDeclInfo->IsFilled)
944     inspectThisDecl();
945   return ThisDeclInfo->CurrentDecl &&
946          isa<ObjCInterfaceDecl>(ThisDeclInfo->CurrentDecl);
947 }
948 
949 bool Sema::isObjCProtocolDecl() {
950   if (!ThisDeclInfo)
951     return false;
952   if (!ThisDeclInfo->IsFilled)
953     inspectThisDecl();
954   return ThisDeclInfo->CurrentDecl &&
955          isa<ObjCProtocolDecl>(ThisDeclInfo->CurrentDecl);
956 }
957 
958 ArrayRef<const ParmVarDecl *> Sema::getParamVars() {
959   if (!ThisDeclInfo->IsFilled)
960     inspectThisDecl();
961   return ThisDeclInfo->ParamVars;
962 }
963 
964 void Sema::inspectThisDecl() {
965   ThisDeclInfo->fill();
966 }
967 
968 unsigned Sema::resolveParmVarReference(StringRef Name,
969                                        ArrayRef<const ParmVarDecl *> ParamVars) {
970   for (unsigned i = 0, e = ParamVars.size(); i != e; ++i) {
971     const IdentifierInfo *II = ParamVars[i]->getIdentifier();
972     if (II && II->getName() == Name)
973       return i;
974   }
975   if (Name == "..." && isFunctionOrMethodVariadic())
976     return ParamCommandComment::VarArgParamIndex;
977   return ParamCommandComment::InvalidParamIndex;
978 }
979 
980 namespace {
981 class SimpleTypoCorrector {
982   const NamedDecl *BestDecl;
983 
984   StringRef Typo;
985   const unsigned MaxEditDistance;
986 
987   unsigned BestEditDistance;
988   unsigned BestIndex;
989   unsigned NextIndex;
990 
991 public:
992   explicit SimpleTypoCorrector(StringRef Typo)
993       : BestDecl(nullptr), Typo(Typo), MaxEditDistance((Typo.size() + 2) / 3),
994         BestEditDistance(MaxEditDistance + 1), BestIndex(0), NextIndex(0) {}
995 
996   void addDecl(const NamedDecl *ND);
997 
998   const NamedDecl *getBestDecl() const {
999     if (BestEditDistance > MaxEditDistance)
1000       return nullptr;
1001 
1002     return BestDecl;
1003   }
1004 
1005   unsigned getBestDeclIndex() const {
1006     assert(getBestDecl());
1007     return BestIndex;
1008   }
1009 };
1010 
1011 void SimpleTypoCorrector::addDecl(const NamedDecl *ND) {
1012   unsigned CurrIndex = NextIndex++;
1013 
1014   const IdentifierInfo *II = ND->getIdentifier();
1015   if (!II)
1016     return;
1017 
1018   StringRef Name = II->getName();
1019   unsigned MinPossibleEditDistance = abs((int)Name.size() - (int)Typo.size());
1020   if (MinPossibleEditDistance > 0 &&
1021       Typo.size() / MinPossibleEditDistance < 3)
1022     return;
1023 
1024   unsigned EditDistance = Typo.edit_distance(Name, true, MaxEditDistance);
1025   if (EditDistance < BestEditDistance) {
1026     BestEditDistance = EditDistance;
1027     BestDecl = ND;
1028     BestIndex = CurrIndex;
1029   }
1030 }
1031 } // end anonymous namespace
1032 
1033 unsigned Sema::correctTypoInParmVarReference(
1034                                     StringRef Typo,
1035                                     ArrayRef<const ParmVarDecl *> ParamVars) {
1036   SimpleTypoCorrector Corrector(Typo);
1037   for (unsigned i = 0, e = ParamVars.size(); i != e; ++i)
1038     Corrector.addDecl(ParamVars[i]);
1039   if (Corrector.getBestDecl())
1040     return Corrector.getBestDeclIndex();
1041   else
1042     return ParamCommandComment::InvalidParamIndex;
1043 }
1044 
1045 namespace {
1046 bool ResolveTParamReferenceHelper(
1047                             StringRef Name,
1048                             const TemplateParameterList *TemplateParameters,
1049                             SmallVectorImpl<unsigned> *Position) {
1050   for (unsigned i = 0, e = TemplateParameters->size(); i != e; ++i) {
1051     const NamedDecl *Param = TemplateParameters->getParam(i);
1052     const IdentifierInfo *II = Param->getIdentifier();
1053     if (II && II->getName() == Name) {
1054       Position->push_back(i);
1055       return true;
1056     }
1057 
1058     if (const TemplateTemplateParmDecl *TTP =
1059             dyn_cast<TemplateTemplateParmDecl>(Param)) {
1060       Position->push_back(i);
1061       if (ResolveTParamReferenceHelper(Name, TTP->getTemplateParameters(),
1062                                        Position))
1063         return true;
1064       Position->pop_back();
1065     }
1066   }
1067   return false;
1068 }
1069 } // end anonymous namespace
1070 
1071 bool Sema::resolveTParamReference(
1072                             StringRef Name,
1073                             const TemplateParameterList *TemplateParameters,
1074                             SmallVectorImpl<unsigned> *Position) {
1075   Position->clear();
1076   if (!TemplateParameters)
1077     return false;
1078 
1079   return ResolveTParamReferenceHelper(Name, TemplateParameters, Position);
1080 }
1081 
1082 namespace {
1083 void CorrectTypoInTParamReferenceHelper(
1084                             const TemplateParameterList *TemplateParameters,
1085                             SimpleTypoCorrector &Corrector) {
1086   for (unsigned i = 0, e = TemplateParameters->size(); i != e; ++i) {
1087     const NamedDecl *Param = TemplateParameters->getParam(i);
1088     Corrector.addDecl(Param);
1089 
1090     if (const TemplateTemplateParmDecl *TTP =
1091             dyn_cast<TemplateTemplateParmDecl>(Param))
1092       CorrectTypoInTParamReferenceHelper(TTP->getTemplateParameters(),
1093                                          Corrector);
1094   }
1095 }
1096 } // end anonymous namespace
1097 
1098 StringRef Sema::correctTypoInTParamReference(
1099                             StringRef Typo,
1100                             const TemplateParameterList *TemplateParameters) {
1101   SimpleTypoCorrector Corrector(Typo);
1102   CorrectTypoInTParamReferenceHelper(TemplateParameters, Corrector);
1103   if (const NamedDecl *ND = Corrector.getBestDecl()) {
1104     const IdentifierInfo *II = ND->getIdentifier();
1105     assert(II && "SimpleTypoCorrector should not return this decl");
1106     return II->getName();
1107   }
1108   return StringRef();
1109 }
1110 
1111 InlineCommandComment::RenderKind
1112 Sema::getInlineCommandRenderKind(StringRef Name) const {
1113   assert(Traits.getCommandInfo(Name)->IsInlineCommand);
1114 
1115   return llvm::StringSwitch<InlineCommandComment::RenderKind>(Name)
1116       .Case("b", InlineCommandComment::RenderBold)
1117       .Cases("c", "p", InlineCommandComment::RenderMonospaced)
1118       .Cases("a", "e", "em", InlineCommandComment::RenderEmphasized)
1119       .Case("anchor", InlineCommandComment::RenderAnchor)
1120       .Default(InlineCommandComment::RenderNormal);
1121 }
1122 
1123 } // end namespace comments
1124 } // end namespace clang
1125