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/SourceManager.h"
16 #include "clang/Lex/Preprocessor.h"
17 #include "llvm/ADT/SmallString.h"
18 #include "llvm/ADT/StringSwitch.h"
19 
20 namespace clang {
21 namespace comments {
22 
23 namespace {
24 #include "clang/AST/CommentHTMLTagsProperties.inc"
25 } // end anonymous namespace
26 
27 Sema::Sema(llvm::BumpPtrAllocator &Allocator, const SourceManager &SourceMgr,
28            DiagnosticsEngine &Diags, CommandTraits &Traits,
29            const Preprocessor *PP) :
30     Allocator(Allocator), SourceMgr(SourceMgr), Diags(Diags), Traits(Traits),
31     PP(PP), ThisDeclInfo(nullptr), BriefCommand(nullptr),
32     HeaderfileCommand(nullptr) {
33 }
34 
35 void Sema::setDecl(const Decl *D) {
36   if (!D)
37     return;
38 
39   ThisDeclInfo = new (Allocator) DeclInfo;
40   ThisDeclInfo->CommentDecl = D;
41   ThisDeclInfo->IsFilled = false;
42 }
43 
44 ParagraphComment *Sema::actOnParagraphComment(
45                               ArrayRef<InlineContentComment *> Content) {
46   return new (Allocator) ParagraphComment(Content);
47 }
48 
49 BlockCommandComment *Sema::actOnBlockCommandStart(
50                                       SourceLocation LocBegin,
51                                       SourceLocation LocEnd,
52                                       unsigned CommandID,
53                                       CommandMarkerKind CommandMarker) {
54   BlockCommandComment *BC = new (Allocator) BlockCommandComment(LocBegin, LocEnd,
55                                                                 CommandID,
56                                                                 CommandMarker);
57   checkContainerDecl(BC);
58   return BC;
59 }
60 
61 void Sema::actOnBlockCommandArgs(BlockCommandComment *Command,
62                                  ArrayRef<BlockCommandComment::Argument> Args) {
63   Command->setArgs(Args);
64 }
65 
66 void Sema::actOnBlockCommandFinish(BlockCommandComment *Command,
67                                    ParagraphComment *Paragraph) {
68   Command->setParagraph(Paragraph);
69   checkBlockCommandEmptyParagraph(Command);
70   checkBlockCommandDuplicate(Command);
71   if (ThisDeclInfo) {
72     // These checks only make sense if the comment is attached to a
73     // declaration.
74     checkReturnsCommand(Command);
75     checkDeprecatedCommand(Command);
76   }
77 }
78 
79 ParamCommandComment *Sema::actOnParamCommandStart(
80                                       SourceLocation LocBegin,
81                                       SourceLocation LocEnd,
82                                       unsigned CommandID,
83                                       CommandMarkerKind CommandMarker) {
84   ParamCommandComment *Command =
85       new (Allocator) ParamCommandComment(LocBegin, LocEnd, CommandID,
86                                           CommandMarker);
87 
88   if (!isFunctionDecl() && !isFunctionOrBlockPointerVarLikeDecl())
89     Diag(Command->getLocation(),
90          diag::warn_doc_param_not_attached_to_a_function_decl)
91       << CommandMarker
92       << Command->getCommandNameRange(Traits);
93 
94   return Command;
95 }
96 
97 void Sema::checkFunctionDeclVerbatimLine(const BlockCommandComment *Comment) {
98   const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
99   if (!Info->IsFunctionDeclarationCommand)
100     return;
101 
102   unsigned DiagSelect;
103   switch (Comment->getCommandID()) {
104     case CommandTraits::KCI_function:
105       DiagSelect = (!isAnyFunctionDecl() && !isFunctionTemplateDecl())? 1 : 0;
106       break;
107     case CommandTraits::KCI_functiongroup:
108       DiagSelect = (!isAnyFunctionDecl() && !isFunctionTemplateDecl())? 2 : 0;
109       break;
110     case CommandTraits::KCI_method:
111       DiagSelect = !isObjCMethodDecl() ? 3 : 0;
112       break;
113     case CommandTraits::KCI_methodgroup:
114       DiagSelect = !isObjCMethodDecl() ? 4 : 0;
115       break;
116     case CommandTraits::KCI_callback:
117       DiagSelect = !isFunctionPointerVarDecl() ? 5 : 0;
118       break;
119     default:
120       DiagSelect = 0;
121       break;
122   }
123   if (DiagSelect)
124     Diag(Comment->getLocation(), diag::warn_doc_function_method_decl_mismatch)
125     << Comment->getCommandMarker()
126     << (DiagSelect-1) << (DiagSelect-1)
127     << Comment->getSourceRange();
128 }
129 
130 void Sema::checkContainerDeclVerbatimLine(const BlockCommandComment *Comment) {
131   const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
132   if (!Info->IsRecordLikeDeclarationCommand)
133     return;
134   unsigned DiagSelect;
135   switch (Comment->getCommandID()) {
136     case CommandTraits::KCI_class:
137       DiagSelect = (!isClassOrStructDecl() && !isClassTemplateDecl()) ? 1 : 0;
138       // Allow @class command on @interface declarations.
139       // FIXME. Currently, \class and @class are indistinguishable. So,
140       // \class is also allowed on an @interface declaration
141       if (DiagSelect && Comment->getCommandMarker() && isObjCInterfaceDecl())
142         DiagSelect = 0;
143       break;
144     case CommandTraits::KCI_interface:
145       DiagSelect = !isObjCInterfaceDecl() ? 2 : 0;
146       break;
147     case CommandTraits::KCI_protocol:
148       DiagSelect = !isObjCProtocolDecl() ? 3 : 0;
149       break;
150     case CommandTraits::KCI_struct:
151       DiagSelect = !isClassOrStructDecl() ? 4 : 0;
152       break;
153     case CommandTraits::KCI_union:
154       DiagSelect = !isUnionDecl() ? 5 : 0;
155       break;
156     default:
157       DiagSelect = 0;
158       break;
159   }
160   if (DiagSelect)
161     Diag(Comment->getLocation(), diag::warn_doc_api_container_decl_mismatch)
162     << Comment->getCommandMarker()
163     << (DiagSelect-1) << (DiagSelect-1)
164     << Comment->getSourceRange();
165 }
166 
167 void Sema::checkContainerDecl(const BlockCommandComment *Comment) {
168   const CommandInfo *Info = Traits.getCommandInfo(Comment->getCommandID());
169   if (!Info->IsRecordLikeDetailCommand || isRecordLikeDecl())
170     return;
171   unsigned DiagSelect;
172   switch (Comment->getCommandID()) {
173     case CommandTraits::KCI_classdesign:
174       DiagSelect = 1;
175       break;
176     case CommandTraits::KCI_coclass:
177       DiagSelect = 2;
178       break;
179     case CommandTraits::KCI_dependency:
180       DiagSelect = 3;
181       break;
182     case CommandTraits::KCI_helper:
183       DiagSelect = 4;
184       break;
185     case CommandTraits::KCI_helperclass:
186       DiagSelect = 5;
187       break;
188     case CommandTraits::KCI_helps:
189       DiagSelect = 6;
190       break;
191     case CommandTraits::KCI_instancesize:
192       DiagSelect = 7;
193       break;
194     case CommandTraits::KCI_ownership:
195       DiagSelect = 8;
196       break;
197     case CommandTraits::KCI_performance:
198       DiagSelect = 9;
199       break;
200     case CommandTraits::KCI_security:
201       DiagSelect = 10;
202       break;
203     case CommandTraits::KCI_superclass:
204       DiagSelect = 11;
205       break;
206     default:
207       DiagSelect = 0;
208       break;
209   }
210   if (DiagSelect)
211     Diag(Comment->getLocation(), diag::warn_doc_container_decl_mismatch)
212     << Comment->getCommandMarker()
213     << (DiagSelect-1)
214     << Comment->getSourceRange();
215 }
216 
217 /// Turn a string into the corresponding PassDirection or -1 if it's not
218 /// valid.
219 static int getParamPassDirection(StringRef Arg) {
220   return llvm::StringSwitch<int>(Arg)
221       .Case("[in]", ParamCommandComment::In)
222       .Case("[out]", ParamCommandComment::Out)
223       .Cases("[in,out]", "[out,in]", ParamCommandComment::InOut)
224       .Default(-1);
225 }
226 
227 void Sema::actOnParamCommandDirectionArg(ParamCommandComment *Command,
228                                          SourceLocation ArgLocBegin,
229                                          SourceLocation ArgLocEnd,
230                                          StringRef Arg) {
231   std::string ArgLower = Arg.lower();
232   int Direction = getParamPassDirection(ArgLower);
233 
234   if (Direction == -1) {
235     // Try again with whitespace removed.
236     ArgLower.erase(
237         std::remove_if(ArgLower.begin(), ArgLower.end(), clang::isWhitespace),
238         ArgLower.end());
239     Direction = getParamPassDirection(ArgLower);
240 
241     SourceRange ArgRange(ArgLocBegin, ArgLocEnd);
242     if (Direction != -1) {
243       const char *FixedName = ParamCommandComment::getDirectionAsString(
244           (ParamCommandComment::PassDirection)Direction);
245       Diag(ArgLocBegin, diag::warn_doc_param_spaces_in_direction)
246           << ArgRange << FixItHint::CreateReplacement(ArgRange, FixedName);
247     } else {
248       Diag(ArgLocBegin, diag::warn_doc_param_invalid_direction) << ArgRange;
249       Direction = ParamCommandComment::In; // Sane fall back.
250     }
251   }
252   Command->setDirection((ParamCommandComment::PassDirection)Direction,
253                         /*Explicit=*/true);
254 }
255 
256 void Sema::actOnParamCommandParamNameArg(ParamCommandComment *Command,
257                                          SourceLocation ArgLocBegin,
258                                          SourceLocation ArgLocEnd,
259                                          StringRef Arg) {
260   // Parser will not feed us more arguments than needed.
261   assert(Command->getNumArgs() == 0);
262 
263   if (!Command->isDirectionExplicit()) {
264     // User didn't provide a direction argument.
265     Command->setDirection(ParamCommandComment::In, /* Explicit = */ false);
266   }
267   typedef BlockCommandComment::Argument Argument;
268   Argument *A = new (Allocator) Argument(SourceRange(ArgLocBegin,
269                                                      ArgLocEnd),
270                                          Arg);
271   Command->setArgs(llvm::makeArrayRef(A, 1));
272 }
273 
274 void Sema::actOnParamCommandFinish(ParamCommandComment *Command,
275                                    ParagraphComment *Paragraph) {
276   Command->setParagraph(Paragraph);
277   checkBlockCommandEmptyParagraph(Command);
278 }
279 
280 TParamCommandComment *Sema::actOnTParamCommandStart(
281                                       SourceLocation LocBegin,
282                                       SourceLocation LocEnd,
283                                       unsigned CommandID,
284                                       CommandMarkerKind CommandMarker) {
285   TParamCommandComment *Command =
286       new (Allocator) TParamCommandComment(LocBegin, LocEnd, CommandID,
287                                            CommandMarker);
288 
289   if (!isTemplateOrSpecialization())
290     Diag(Command->getLocation(),
291          diag::warn_doc_tparam_not_attached_to_a_template_decl)
292       << CommandMarker
293       << Command->getCommandNameRange(Traits);
294 
295   return Command;
296 }
297 
298 void Sema::actOnTParamCommandParamNameArg(TParamCommandComment *Command,
299                                           SourceLocation ArgLocBegin,
300                                           SourceLocation ArgLocEnd,
301                                           StringRef Arg) {
302   // Parser will not feed us more arguments than needed.
303   assert(Command->getNumArgs() == 0);
304 
305   typedef BlockCommandComment::Argument Argument;
306   Argument *A = new (Allocator) Argument(SourceRange(ArgLocBegin,
307                                                      ArgLocEnd),
308                                          Arg);
309   Command->setArgs(llvm::makeArrayRef(A, 1));
310 
311   if (!isTemplateOrSpecialization()) {
312     // We already warned that this \\tparam is not attached to a template decl.
313     return;
314   }
315 
316   const TemplateParameterList *TemplateParameters =
317       ThisDeclInfo->TemplateParameters;
318   SmallVector<unsigned, 2> Position;
319   if (resolveTParamReference(Arg, TemplateParameters, &Position)) {
320     Command->setPosition(copyArray(llvm::makeArrayRef(Position)));
321     TParamCommandComment *&PrevCommand = TemplateParameterDocs[Arg];
322     if (PrevCommand) {
323       SourceRange ArgRange(ArgLocBegin, ArgLocEnd);
324       Diag(ArgLocBegin, diag::warn_doc_tparam_duplicate)
325         << Arg << ArgRange;
326       Diag(PrevCommand->getLocation(), diag::note_doc_tparam_previous)
327         << PrevCommand->getParamNameRange();
328     }
329     PrevCommand = Command;
330     return;
331   }
332 
333   SourceRange ArgRange(ArgLocBegin, ArgLocEnd);
334   Diag(ArgLocBegin, diag::warn_doc_tparam_not_found)
335     << Arg << ArgRange;
336 
337   if (!TemplateParameters || TemplateParameters->size() == 0)
338     return;
339 
340   StringRef CorrectedName;
341   if (TemplateParameters->size() == 1) {
342     const NamedDecl *Param = TemplateParameters->getParam(0);
343     const IdentifierInfo *II = Param->getIdentifier();
344     if (II)
345       CorrectedName = II->getName();
346   } else {
347     CorrectedName = correctTypoInTParamReference(Arg, TemplateParameters);
348   }
349 
350   if (!CorrectedName.empty()) {
351     Diag(ArgLocBegin, diag::note_doc_tparam_name_suggestion)
352       << CorrectedName
353       << FixItHint::CreateReplacement(ArgRange, CorrectedName);
354   }
355 }
356 
357 void Sema::actOnTParamCommandFinish(TParamCommandComment *Command,
358                                     ParagraphComment *Paragraph) {
359   Command->setParagraph(Paragraph);
360   checkBlockCommandEmptyParagraph(Command);
361 }
362 
363 InlineCommandComment *Sema::actOnInlineCommand(SourceLocation CommandLocBegin,
364                                                SourceLocation CommandLocEnd,
365                                                unsigned CommandID) {
366   ArrayRef<InlineCommandComment::Argument> Args;
367   StringRef CommandName = Traits.getCommandInfo(CommandID)->Name;
368   return new (Allocator) InlineCommandComment(
369                                   CommandLocBegin,
370                                   CommandLocEnd,
371                                   CommandID,
372                                   getInlineCommandRenderKind(CommandName),
373                                   Args);
374 }
375 
376 InlineCommandComment *Sema::actOnInlineCommand(SourceLocation CommandLocBegin,
377                                                SourceLocation CommandLocEnd,
378                                                unsigned CommandID,
379                                                SourceLocation ArgLocBegin,
380                                                SourceLocation ArgLocEnd,
381                                                StringRef Arg) {
382   typedef InlineCommandComment::Argument Argument;
383   Argument *A = new (Allocator) Argument(SourceRange(ArgLocBegin,
384                                                      ArgLocEnd),
385                                          Arg);
386   StringRef CommandName = Traits.getCommandInfo(CommandID)->Name;
387 
388   return new (Allocator) InlineCommandComment(
389                                   CommandLocBegin,
390                                   CommandLocEnd,
391                                   CommandID,
392                                   getInlineCommandRenderKind(CommandName),
393                                   llvm::makeArrayRef(A, 1));
394 }
395 
396 InlineContentComment *Sema::actOnUnknownCommand(SourceLocation LocBegin,
397                                                 SourceLocation LocEnd,
398                                                 StringRef CommandName) {
399   unsigned CommandID = Traits.registerUnknownCommand(CommandName)->getID();
400   return actOnUnknownCommand(LocBegin, LocEnd, CommandID);
401 }
402 
403 InlineContentComment *Sema::actOnUnknownCommand(SourceLocation LocBegin,
404                                                 SourceLocation LocEnd,
405                                                 unsigned CommandID) {
406   ArrayRef<InlineCommandComment::Argument> Args;
407   return new (Allocator) InlineCommandComment(
408                                   LocBegin, LocEnd, CommandID,
409                                   InlineCommandComment::RenderNormal,
410                                   Args);
411 }
412 
413 TextComment *Sema::actOnText(SourceLocation LocBegin,
414                              SourceLocation LocEnd,
415                              StringRef Text) {
416   return new (Allocator) TextComment(LocBegin, LocEnd, Text);
417 }
418 
419 VerbatimBlockComment *Sema::actOnVerbatimBlockStart(SourceLocation Loc,
420                                                     unsigned CommandID) {
421   StringRef CommandName = Traits.getCommandInfo(CommandID)->Name;
422   return new (Allocator) VerbatimBlockComment(
423                                   Loc,
424                                   Loc.getLocWithOffset(1 + CommandName.size()),
425                                   CommandID);
426 }
427 
428 VerbatimBlockLineComment *Sema::actOnVerbatimBlockLine(SourceLocation Loc,
429                                                        StringRef Text) {
430   return new (Allocator) VerbatimBlockLineComment(Loc, Text);
431 }
432 
433 void Sema::actOnVerbatimBlockFinish(
434                             VerbatimBlockComment *Block,
435                             SourceLocation CloseNameLocBegin,
436                             StringRef CloseName,
437                             ArrayRef<VerbatimBlockLineComment *> Lines) {
438   Block->setCloseName(CloseName, CloseNameLocBegin);
439   Block->setLines(Lines);
440 }
441 
442 VerbatimLineComment *Sema::actOnVerbatimLine(SourceLocation LocBegin,
443                                              unsigned CommandID,
444                                              SourceLocation TextBegin,
445                                              StringRef Text) {
446   VerbatimLineComment *VL = new (Allocator) VerbatimLineComment(
447                               LocBegin,
448                               TextBegin.getLocWithOffset(Text.size()),
449                               CommandID,
450                               TextBegin,
451                               Text);
452   checkFunctionDeclVerbatimLine(VL);
453   checkContainerDeclVerbatimLine(VL);
454   return VL;
455 }
456 
457 HTMLStartTagComment *Sema::actOnHTMLStartTagStart(SourceLocation LocBegin,
458                                                   StringRef TagName) {
459   return new (Allocator) HTMLStartTagComment(LocBegin, TagName);
460 }
461 
462 void Sema::actOnHTMLStartTagFinish(
463                               HTMLStartTagComment *Tag,
464                               ArrayRef<HTMLStartTagComment::Attribute> Attrs,
465                               SourceLocation GreaterLoc,
466                               bool IsSelfClosing) {
467   Tag->setAttrs(Attrs);
468   Tag->setGreaterLoc(GreaterLoc);
469   if (IsSelfClosing)
470     Tag->setSelfClosing();
471   else if (!isHTMLEndTagForbidden(Tag->getTagName()))
472     HTMLOpenTags.push_back(Tag);
473 }
474 
475 HTMLEndTagComment *Sema::actOnHTMLEndTag(SourceLocation LocBegin,
476                                          SourceLocation LocEnd,
477                                          StringRef TagName) {
478   HTMLEndTagComment *HET =
479       new (Allocator) HTMLEndTagComment(LocBegin, LocEnd, TagName);
480   if (isHTMLEndTagForbidden(TagName)) {
481     Diag(HET->getLocation(), diag::warn_doc_html_end_forbidden)
482       << TagName << HET->getSourceRange();
483     HET->setIsMalformed();
484     return HET;
485   }
486 
487   bool FoundOpen = false;
488   for (SmallVectorImpl<HTMLStartTagComment *>::const_reverse_iterator
489        I = HTMLOpenTags.rbegin(), E = HTMLOpenTags.rend();
490        I != E; ++I) {
491     if ((*I)->getTagName() == TagName) {
492       FoundOpen = true;
493       break;
494     }
495   }
496   if (!FoundOpen) {
497     Diag(HET->getLocation(), diag::warn_doc_html_end_unbalanced)
498       << HET->getSourceRange();
499     HET->setIsMalformed();
500     return HET;
501   }
502 
503   while (!HTMLOpenTags.empty()) {
504     HTMLStartTagComment *HST = HTMLOpenTags.pop_back_val();
505     StringRef LastNotClosedTagName = HST->getTagName();
506     if (LastNotClosedTagName == TagName) {
507       // If the start tag is malformed, end tag is malformed as well.
508       if (HST->isMalformed())
509         HET->setIsMalformed();
510       break;
511     }
512 
513     if (isHTMLEndTagOptional(LastNotClosedTagName))
514       continue;
515 
516     bool OpenLineInvalid;
517     const unsigned OpenLine = SourceMgr.getPresumedLineNumber(
518                                                 HST->getLocation(),
519                                                 &OpenLineInvalid);
520     bool CloseLineInvalid;
521     const unsigned CloseLine = SourceMgr.getPresumedLineNumber(
522                                                 HET->getLocation(),
523                                                 &CloseLineInvalid);
524 
525     if (OpenLineInvalid || CloseLineInvalid || OpenLine == CloseLine) {
526       Diag(HST->getLocation(), diag::warn_doc_html_start_end_mismatch)
527         << HST->getTagName() << HET->getTagName()
528         << HST->getSourceRange() << HET->getSourceRange();
529       HST->setIsMalformed();
530     } else {
531       Diag(HST->getLocation(), diag::warn_doc_html_start_end_mismatch)
532         << HST->getTagName() << HET->getTagName()
533         << HST->getSourceRange();
534       Diag(HET->getLocation(), diag::note_doc_html_end_tag)
535         << HET->getSourceRange();
536       HST->setIsMalformed();
537     }
538   }
539 
540   return HET;
541 }
542 
543 FullComment *Sema::actOnFullComment(
544                               ArrayRef<BlockContentComment *> Blocks) {
545   FullComment *FC = new (Allocator) FullComment(Blocks, ThisDeclInfo);
546   resolveParamCommandIndexes(FC);
547 
548   // Complain about HTML tags that are not closed.
549   while (!HTMLOpenTags.empty()) {
550     HTMLStartTagComment *HST = HTMLOpenTags.pop_back_val();
551     if (isHTMLEndTagOptional(HST->getTagName()))
552       continue;
553 
554     Diag(HST->getLocation(), diag::warn_doc_html_missing_end_tag)
555       << HST->getTagName() << HST->getSourceRange();
556     HST->setIsMalformed();
557   }
558 
559   return FC;
560 }
561 
562 void Sema::checkBlockCommandEmptyParagraph(BlockCommandComment *Command) {
563   if (Traits.getCommandInfo(Command->getCommandID())->IsEmptyParagraphAllowed)
564     return;
565 
566   ParagraphComment *Paragraph = Command->getParagraph();
567   if (Paragraph->isWhitespace()) {
568     SourceLocation DiagLoc;
569     if (Command->getNumArgs() > 0)
570       DiagLoc = Command->getArgRange(Command->getNumArgs() - 1).getEnd();
571     if (!DiagLoc.isValid())
572       DiagLoc = Command->getCommandNameRange(Traits).getEnd();
573     Diag(DiagLoc, diag::warn_doc_block_command_empty_paragraph)
574       << Command->getCommandMarker()
575       << Command->getCommandName(Traits)
576       << Command->getSourceRange();
577   }
578 }
579 
580 void Sema::checkReturnsCommand(const BlockCommandComment *Command) {
581   if (!Traits.getCommandInfo(Command->getCommandID())->IsReturnsCommand)
582     return;
583 
584   assert(ThisDeclInfo && "should not call this check on a bare comment");
585 
586   // We allow the return command for all @properties because it can be used
587   // to document the value that the property getter returns.
588   if (isObjCPropertyDecl())
589     return;
590   if (isFunctionDecl() || isFunctionOrBlockPointerVarLikeDecl()) {
591     assert(!ThisDeclInfo->ReturnType.isNull() &&
592            "should have a valid return type");
593     if (ThisDeclInfo->ReturnType->isVoidType()) {
594       unsigned DiagKind;
595       switch (ThisDeclInfo->CommentDecl->getKind()) {
596       default:
597         if (ThisDeclInfo->IsObjCMethod)
598           DiagKind = 3;
599         else
600           DiagKind = 0;
601         break;
602       case Decl::CXXConstructor:
603         DiagKind = 1;
604         break;
605       case Decl::CXXDestructor:
606         DiagKind = 2;
607         break;
608       }
609       Diag(Command->getLocation(),
610            diag::warn_doc_returns_attached_to_a_void_function)
611         << Command->getCommandMarker()
612         << Command->getCommandName(Traits)
613         << DiagKind
614         << Command->getSourceRange();
615     }
616     return;
617   }
618 
619   Diag(Command->getLocation(),
620        diag::warn_doc_returns_not_attached_to_a_function_decl)
621     << Command->getCommandMarker()
622     << Command->getCommandName(Traits)
623     << Command->getSourceRange();
624 }
625 
626 void Sema::checkBlockCommandDuplicate(const BlockCommandComment *Command) {
627   const CommandInfo *Info = Traits.getCommandInfo(Command->getCommandID());
628   const BlockCommandComment *PrevCommand = nullptr;
629   if (Info->IsBriefCommand) {
630     if (!BriefCommand) {
631       BriefCommand = Command;
632       return;
633     }
634     PrevCommand = BriefCommand;
635   } else if (Info->IsHeaderfileCommand) {
636     if (!HeaderfileCommand) {
637       HeaderfileCommand = Command;
638       return;
639     }
640     PrevCommand = HeaderfileCommand;
641   } else {
642     // We don't want to check this command for duplicates.
643     return;
644   }
645   StringRef CommandName = Command->getCommandName(Traits);
646   StringRef PrevCommandName = PrevCommand->getCommandName(Traits);
647   Diag(Command->getLocation(), diag::warn_doc_block_command_duplicate)
648       << Command->getCommandMarker()
649       << CommandName
650       << Command->getSourceRange();
651   if (CommandName == PrevCommandName)
652     Diag(PrevCommand->getLocation(), diag::note_doc_block_command_previous)
653         << PrevCommand->getCommandMarker()
654         << PrevCommandName
655         << PrevCommand->getSourceRange();
656   else
657     Diag(PrevCommand->getLocation(),
658          diag::note_doc_block_command_previous_alias)
659         << PrevCommand->getCommandMarker()
660         << PrevCommandName
661         << CommandName;
662 }
663 
664 void Sema::checkDeprecatedCommand(const BlockCommandComment *Command) {
665   if (!Traits.getCommandInfo(Command->getCommandID())->IsDeprecatedCommand)
666     return;
667 
668   assert(ThisDeclInfo && "should not call this check on a bare comment");
669 
670   const Decl *D = ThisDeclInfo->CommentDecl;
671   if (!D)
672     return;
673 
674   if (D->hasAttr<DeprecatedAttr>() ||
675       D->hasAttr<AvailabilityAttr>() ||
676       D->hasAttr<UnavailableAttr>())
677     return;
678 
679   Diag(Command->getLocation(), diag::warn_doc_deprecated_not_sync)
680       << Command->getSourceRange() << Command->getCommandMarker();
681 
682   // Try to emit a fixit with a deprecation attribute.
683   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
684     // Don't emit a Fix-It for non-member function definitions.  GCC does not
685     // accept attributes on them.
686     const DeclContext *Ctx = FD->getDeclContext();
687     if ((!Ctx || !Ctx->isRecord()) &&
688         FD->doesThisDeclarationHaveABody())
689       return;
690 
691     const LangOptions &LO = FD->getASTContext().getLangOpts();
692     const bool DoubleSquareBracket = LO.CPlusPlus14 || LO.C2x;
693     StringRef AttributeSpelling =
694         DoubleSquareBracket ? "[[deprecated]]" : "__attribute__((deprecated))";
695     if (PP) {
696       // Try to find a replacement macro:
697       // - In C2x/C++14 we prefer [[deprecated]].
698       // - If not found or an older C/C++ look for __attribute__((deprecated)).
699       StringRef MacroName;
700       if (DoubleSquareBracket) {
701         TokenValue Tokens[] = {tok::l_square, tok::l_square,
702                                PP->getIdentifierInfo("deprecated"),
703                                tok::r_square, tok::r_square};
704         MacroName = PP->getLastMacroWithSpelling(FD->getLocation(), Tokens);
705         if (!MacroName.empty())
706           AttributeSpelling = MacroName;
707       }
708 
709       if (MacroName.empty()) {
710         TokenValue Tokens[] = {
711             tok::kw___attribute, tok::l_paren,
712             tok::l_paren,        PP->getIdentifierInfo("deprecated"),
713             tok::r_paren,        tok::r_paren};
714         StringRef MacroName =
715             PP->getLastMacroWithSpelling(FD->getLocation(), Tokens);
716         if (!MacroName.empty())
717           AttributeSpelling = MacroName;
718       }
719     }
720 
721     SmallString<64> TextToInsert = AttributeSpelling;
722     TextToInsert += " ";
723     SourceLocation Loc = FD->getSourceRange().getBegin();
724     Diag(Loc, diag::note_add_deprecation_attr)
725         << FixItHint::CreateInsertion(Loc, TextToInsert);
726   }
727 }
728 
729 void Sema::resolveParamCommandIndexes(const FullComment *FC) {
730   if (!isFunctionDecl()) {
731     // We already warned that \\param commands are not attached to a function
732     // decl.
733     return;
734   }
735 
736   SmallVector<ParamCommandComment *, 8> UnresolvedParamCommands;
737 
738   // Comment AST nodes that correspond to \c ParamVars for which we have
739   // found a \\param command or NULL if no documentation was found so far.
740   SmallVector<ParamCommandComment *, 8> ParamVarDocs;
741 
742   ArrayRef<const ParmVarDecl *> ParamVars = getParamVars();
743   ParamVarDocs.resize(ParamVars.size(), nullptr);
744 
745   // First pass over all \\param commands: resolve all parameter names.
746   for (Comment::child_iterator I = FC->child_begin(), E = FC->child_end();
747        I != E; ++I) {
748     ParamCommandComment *PCC = dyn_cast<ParamCommandComment>(*I);
749     if (!PCC || !PCC->hasParamName())
750       continue;
751     StringRef ParamName = PCC->getParamNameAsWritten();
752 
753     // Check that referenced parameter name is in the function decl.
754     const unsigned ResolvedParamIndex = resolveParmVarReference(ParamName,
755                                                                 ParamVars);
756     if (ResolvedParamIndex == ParamCommandComment::VarArgParamIndex) {
757       PCC->setIsVarArgParam();
758       continue;
759     }
760     if (ResolvedParamIndex == ParamCommandComment::InvalidParamIndex) {
761       UnresolvedParamCommands.push_back(PCC);
762       continue;
763     }
764     PCC->setParamIndex(ResolvedParamIndex);
765     if (ParamVarDocs[ResolvedParamIndex]) {
766       SourceRange ArgRange = PCC->getParamNameRange();
767       Diag(ArgRange.getBegin(), diag::warn_doc_param_duplicate)
768         << ParamName << ArgRange;
769       ParamCommandComment *PrevCommand = ParamVarDocs[ResolvedParamIndex];
770       Diag(PrevCommand->getLocation(), diag::note_doc_param_previous)
771         << PrevCommand->getParamNameRange();
772     }
773     ParamVarDocs[ResolvedParamIndex] = PCC;
774   }
775 
776   // Find parameter declarations that have no corresponding \\param.
777   SmallVector<const ParmVarDecl *, 8> OrphanedParamDecls;
778   for (unsigned i = 0, e = ParamVarDocs.size(); i != e; ++i) {
779     if (!ParamVarDocs[i])
780       OrphanedParamDecls.push_back(ParamVars[i]);
781   }
782 
783   // Second pass over unresolved \\param commands: do typo correction.
784   // Suggest corrections from a set of parameter declarations that have no
785   // corresponding \\param.
786   for (unsigned i = 0, e = UnresolvedParamCommands.size(); i != e; ++i) {
787     const ParamCommandComment *PCC = UnresolvedParamCommands[i];
788 
789     SourceRange ArgRange = PCC->getParamNameRange();
790     StringRef ParamName = PCC->getParamNameAsWritten();
791     Diag(ArgRange.getBegin(), diag::warn_doc_param_not_found)
792       << ParamName << ArgRange;
793 
794     // All parameters documented -- can't suggest a correction.
795     if (OrphanedParamDecls.size() == 0)
796       continue;
797 
798     unsigned CorrectedParamIndex = ParamCommandComment::InvalidParamIndex;
799     if (OrphanedParamDecls.size() == 1) {
800       // If one parameter is not documented then that parameter is the only
801       // possible suggestion.
802       CorrectedParamIndex = 0;
803     } else {
804       // Do typo correction.
805       CorrectedParamIndex = correctTypoInParmVarReference(ParamName,
806                                                           OrphanedParamDecls);
807     }
808     if (CorrectedParamIndex != ParamCommandComment::InvalidParamIndex) {
809       const ParmVarDecl *CorrectedPVD = OrphanedParamDecls[CorrectedParamIndex];
810       if (const IdentifierInfo *CorrectedII = CorrectedPVD->getIdentifier())
811         Diag(ArgRange.getBegin(), diag::note_doc_param_name_suggestion)
812           << CorrectedII->getName()
813           << FixItHint::CreateReplacement(ArgRange, CorrectedII->getName());
814     }
815   }
816 }
817 
818 bool Sema::isFunctionDecl() {
819   if (!ThisDeclInfo)
820     return false;
821   if (!ThisDeclInfo->IsFilled)
822     inspectThisDecl();
823   return ThisDeclInfo->getKind() == DeclInfo::FunctionKind;
824 }
825 
826 bool Sema::isAnyFunctionDecl() {
827   return isFunctionDecl() && ThisDeclInfo->CurrentDecl &&
828          isa<FunctionDecl>(ThisDeclInfo->CurrentDecl);
829 }
830 
831 bool Sema::isFunctionOrMethodVariadic() {
832   if (!isFunctionDecl() || !ThisDeclInfo->CurrentDecl)
833     return false;
834   if (const FunctionDecl *FD =
835         dyn_cast<FunctionDecl>(ThisDeclInfo->CurrentDecl))
836     return FD->isVariadic();
837   if (const FunctionTemplateDecl *FTD =
838         dyn_cast<FunctionTemplateDecl>(ThisDeclInfo->CurrentDecl))
839     return FTD->getTemplatedDecl()->isVariadic();
840   if (const ObjCMethodDecl *MD =
841         dyn_cast<ObjCMethodDecl>(ThisDeclInfo->CurrentDecl))
842     return MD->isVariadic();
843   if (const TypedefNameDecl *TD =
844           dyn_cast<TypedefNameDecl>(ThisDeclInfo->CurrentDecl)) {
845     QualType Type = TD->getUnderlyingType();
846     if (Type->isFunctionPointerType() || Type->isBlockPointerType())
847       Type = Type->getPointeeType();
848     if (const auto *FT = Type->getAs<FunctionProtoType>())
849       return FT->isVariadic();
850   }
851   return false;
852 }
853 
854 bool Sema::isObjCMethodDecl() {
855   return isFunctionDecl() && ThisDeclInfo->CurrentDecl &&
856          isa<ObjCMethodDecl>(ThisDeclInfo->CurrentDecl);
857 }
858 
859 bool Sema::isFunctionPointerVarDecl() {
860   if (!ThisDeclInfo)
861     return false;
862   if (!ThisDeclInfo->IsFilled)
863     inspectThisDecl();
864   if (ThisDeclInfo->getKind() == DeclInfo::VariableKind) {
865     if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(ThisDeclInfo->CurrentDecl)) {
866       QualType QT = VD->getType();
867       return QT->isFunctionPointerType();
868     }
869   }
870   return false;
871 }
872 
873 bool Sema::isFunctionOrBlockPointerVarLikeDecl() {
874   if (!ThisDeclInfo)
875     return false;
876   if (!ThisDeclInfo->IsFilled)
877     inspectThisDecl();
878   if (ThisDeclInfo->getKind() != DeclInfo::VariableKind ||
879       !ThisDeclInfo->CurrentDecl)
880     return false;
881   QualType QT;
882   if (const auto *VD = dyn_cast<DeclaratorDecl>(ThisDeclInfo->CurrentDecl))
883     QT = VD->getType();
884   else if (const auto *PD =
885                dyn_cast<ObjCPropertyDecl>(ThisDeclInfo->CurrentDecl))
886     QT = PD->getType();
887   else
888     return false;
889   // We would like to warn about the 'returns'/'param' commands for
890   // variables that don't directly specify the function type, so type aliases
891   // can be ignored.
892   if (QT->getAs<TypedefType>())
893     return false;
894   if (const auto *P = QT->getAs<PointerType>())
895     if (P->getPointeeType()->getAs<TypedefType>())
896       return false;
897   if (const auto *P = QT->getAs<BlockPointerType>())
898     if (P->getPointeeType()->getAs<TypedefType>())
899       return false;
900   return QT->isFunctionPointerType() || QT->isBlockPointerType();
901 }
902 
903 bool Sema::isObjCPropertyDecl() {
904   if (!ThisDeclInfo)
905     return false;
906   if (!ThisDeclInfo->IsFilled)
907     inspectThisDecl();
908   return ThisDeclInfo->CurrentDecl->getKind() == Decl::ObjCProperty;
909 }
910 
911 bool Sema::isTemplateOrSpecialization() {
912   if (!ThisDeclInfo)
913     return false;
914   if (!ThisDeclInfo->IsFilled)
915     inspectThisDecl();
916   return ThisDeclInfo->getTemplateKind() != DeclInfo::NotTemplate;
917 }
918 
919 bool Sema::isRecordLikeDecl() {
920   if (!ThisDeclInfo)
921     return false;
922   if (!ThisDeclInfo->IsFilled)
923     inspectThisDecl();
924   return isUnionDecl() || isClassOrStructDecl() || isObjCInterfaceDecl() ||
925          isObjCProtocolDecl();
926 }
927 
928 bool Sema::isUnionDecl() {
929   if (!ThisDeclInfo)
930     return false;
931   if (!ThisDeclInfo->IsFilled)
932     inspectThisDecl();
933   if (const RecordDecl *RD =
934         dyn_cast_or_null<RecordDecl>(ThisDeclInfo->CurrentDecl))
935     return RD->isUnion();
936   return false;
937 }
938 
939 bool Sema::isClassOrStructDecl() {
940   if (!ThisDeclInfo)
941     return false;
942   if (!ThisDeclInfo->IsFilled)
943     inspectThisDecl();
944   return ThisDeclInfo->CurrentDecl &&
945          isa<RecordDecl>(ThisDeclInfo->CurrentDecl) &&
946          !isUnionDecl();
947 }
948 
949 bool Sema::isClassTemplateDecl() {
950   if (!ThisDeclInfo)
951     return false;
952   if (!ThisDeclInfo->IsFilled)
953     inspectThisDecl();
954   return ThisDeclInfo->CurrentDecl &&
955           (isa<ClassTemplateDecl>(ThisDeclInfo->CurrentDecl));
956 }
957 
958 bool Sema::isFunctionTemplateDecl() {
959   if (!ThisDeclInfo)
960     return false;
961   if (!ThisDeclInfo->IsFilled)
962     inspectThisDecl();
963   return ThisDeclInfo->CurrentDecl &&
964          (isa<FunctionTemplateDecl>(ThisDeclInfo->CurrentDecl));
965 }
966 
967 bool Sema::isObjCInterfaceDecl() {
968   if (!ThisDeclInfo)
969     return false;
970   if (!ThisDeclInfo->IsFilled)
971     inspectThisDecl();
972   return ThisDeclInfo->CurrentDecl &&
973          isa<ObjCInterfaceDecl>(ThisDeclInfo->CurrentDecl);
974 }
975 
976 bool Sema::isObjCProtocolDecl() {
977   if (!ThisDeclInfo)
978     return false;
979   if (!ThisDeclInfo->IsFilled)
980     inspectThisDecl();
981   return ThisDeclInfo->CurrentDecl &&
982          isa<ObjCProtocolDecl>(ThisDeclInfo->CurrentDecl);
983 }
984 
985 ArrayRef<const ParmVarDecl *> Sema::getParamVars() {
986   if (!ThisDeclInfo->IsFilled)
987     inspectThisDecl();
988   return ThisDeclInfo->ParamVars;
989 }
990 
991 void Sema::inspectThisDecl() {
992   ThisDeclInfo->fill();
993 }
994 
995 unsigned Sema::resolveParmVarReference(StringRef Name,
996                                        ArrayRef<const ParmVarDecl *> ParamVars) {
997   for (unsigned i = 0, e = ParamVars.size(); i != e; ++i) {
998     const IdentifierInfo *II = ParamVars[i]->getIdentifier();
999     if (II && II->getName() == Name)
1000       return i;
1001   }
1002   if (Name == "..." && isFunctionOrMethodVariadic())
1003     return ParamCommandComment::VarArgParamIndex;
1004   return ParamCommandComment::InvalidParamIndex;
1005 }
1006 
1007 namespace {
1008 class SimpleTypoCorrector {
1009   const NamedDecl *BestDecl;
1010 
1011   StringRef Typo;
1012   const unsigned MaxEditDistance;
1013 
1014   unsigned BestEditDistance;
1015   unsigned BestIndex;
1016   unsigned NextIndex;
1017 
1018 public:
1019   explicit SimpleTypoCorrector(StringRef Typo)
1020       : BestDecl(nullptr), Typo(Typo), MaxEditDistance((Typo.size() + 2) / 3),
1021         BestEditDistance(MaxEditDistance + 1), BestIndex(0), NextIndex(0) {}
1022 
1023   void addDecl(const NamedDecl *ND);
1024 
1025   const NamedDecl *getBestDecl() const {
1026     if (BestEditDistance > MaxEditDistance)
1027       return nullptr;
1028 
1029     return BestDecl;
1030   }
1031 
1032   unsigned getBestDeclIndex() const {
1033     assert(getBestDecl());
1034     return BestIndex;
1035   }
1036 };
1037 
1038 void SimpleTypoCorrector::addDecl(const NamedDecl *ND) {
1039   unsigned CurrIndex = NextIndex++;
1040 
1041   const IdentifierInfo *II = ND->getIdentifier();
1042   if (!II)
1043     return;
1044 
1045   StringRef Name = II->getName();
1046   unsigned MinPossibleEditDistance = abs((int)Name.size() - (int)Typo.size());
1047   if (MinPossibleEditDistance > 0 &&
1048       Typo.size() / MinPossibleEditDistance < 3)
1049     return;
1050 
1051   unsigned EditDistance = Typo.edit_distance(Name, true, MaxEditDistance);
1052   if (EditDistance < BestEditDistance) {
1053     BestEditDistance = EditDistance;
1054     BestDecl = ND;
1055     BestIndex = CurrIndex;
1056   }
1057 }
1058 } // end anonymous namespace
1059 
1060 unsigned Sema::correctTypoInParmVarReference(
1061                                     StringRef Typo,
1062                                     ArrayRef<const ParmVarDecl *> ParamVars) {
1063   SimpleTypoCorrector Corrector(Typo);
1064   for (unsigned i = 0, e = ParamVars.size(); i != e; ++i)
1065     Corrector.addDecl(ParamVars[i]);
1066   if (Corrector.getBestDecl())
1067     return Corrector.getBestDeclIndex();
1068   else
1069     return ParamCommandComment::InvalidParamIndex;
1070 }
1071 
1072 namespace {
1073 bool ResolveTParamReferenceHelper(
1074                             StringRef Name,
1075                             const TemplateParameterList *TemplateParameters,
1076                             SmallVectorImpl<unsigned> *Position) {
1077   for (unsigned i = 0, e = TemplateParameters->size(); i != e; ++i) {
1078     const NamedDecl *Param = TemplateParameters->getParam(i);
1079     const IdentifierInfo *II = Param->getIdentifier();
1080     if (II && II->getName() == Name) {
1081       Position->push_back(i);
1082       return true;
1083     }
1084 
1085     if (const TemplateTemplateParmDecl *TTP =
1086             dyn_cast<TemplateTemplateParmDecl>(Param)) {
1087       Position->push_back(i);
1088       if (ResolveTParamReferenceHelper(Name, TTP->getTemplateParameters(),
1089                                        Position))
1090         return true;
1091       Position->pop_back();
1092     }
1093   }
1094   return false;
1095 }
1096 } // end anonymous namespace
1097 
1098 bool Sema::resolveTParamReference(
1099                             StringRef Name,
1100                             const TemplateParameterList *TemplateParameters,
1101                             SmallVectorImpl<unsigned> *Position) {
1102   Position->clear();
1103   if (!TemplateParameters)
1104     return false;
1105 
1106   return ResolveTParamReferenceHelper(Name, TemplateParameters, Position);
1107 }
1108 
1109 namespace {
1110 void CorrectTypoInTParamReferenceHelper(
1111                             const TemplateParameterList *TemplateParameters,
1112                             SimpleTypoCorrector &Corrector) {
1113   for (unsigned i = 0, e = TemplateParameters->size(); i != e; ++i) {
1114     const NamedDecl *Param = TemplateParameters->getParam(i);
1115     Corrector.addDecl(Param);
1116 
1117     if (const TemplateTemplateParmDecl *TTP =
1118             dyn_cast<TemplateTemplateParmDecl>(Param))
1119       CorrectTypoInTParamReferenceHelper(TTP->getTemplateParameters(),
1120                                          Corrector);
1121   }
1122 }
1123 } // end anonymous namespace
1124 
1125 StringRef Sema::correctTypoInTParamReference(
1126                             StringRef Typo,
1127                             const TemplateParameterList *TemplateParameters) {
1128   SimpleTypoCorrector Corrector(Typo);
1129   CorrectTypoInTParamReferenceHelper(TemplateParameters, Corrector);
1130   if (const NamedDecl *ND = Corrector.getBestDecl()) {
1131     const IdentifierInfo *II = ND->getIdentifier();
1132     assert(II && "SimpleTypoCorrector should not return this decl");
1133     return II->getName();
1134   }
1135   return StringRef();
1136 }
1137 
1138 InlineCommandComment::RenderKind
1139 Sema::getInlineCommandRenderKind(StringRef Name) const {
1140   assert(Traits.getCommandInfo(Name)->IsInlineCommand);
1141 
1142   return llvm::StringSwitch<InlineCommandComment::RenderKind>(Name)
1143       .Case("b", InlineCommandComment::RenderBold)
1144       .Cases("c", "p", InlineCommandComment::RenderMonospaced)
1145       .Cases("a", "e", "em", InlineCommandComment::RenderEmphasized)
1146       .Case("anchor", InlineCommandComment::RenderAnchor)
1147       .Default(InlineCommandComment::RenderNormal);
1148 }
1149 
1150 } // end namespace comments
1151 } // end namespace clang
1152