1 //===- CodeCompleteConsumer.cpp - Code Completion Interface ---------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //  This file implements the CodeCompleteConsumer class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Sema/CodeCompleteConsumer.h"
15 #include "clang-c/Index.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclBase.h"
18 #include "clang/AST/DeclObjC.h"
19 #include "clang/AST/DeclTemplate.h"
20 #include "clang/AST/DeclarationName.h"
21 #include "clang/AST/Type.h"
22 #include "clang/Basic/IdentifierTable.h"
23 #include "clang/Lex/Preprocessor.h"
24 #include "clang/Sema/Sema.h"
25 #include "llvm/ADT/SmallString.h"
26 #include "llvm/ADT/SmallVector.h"
27 #include "llvm/ADT/StringRef.h"
28 #include "llvm/ADT/Twine.h"
29 #include "llvm/Support/Casting.h"
30 #include "llvm/Support/Compiler.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/FormatVariadic.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include <algorithm>
35 #include <cassert>
36 #include <cstdint>
37 #include <string>
38 
39 using namespace clang;
40 
41 //===----------------------------------------------------------------------===//
42 // Code completion context implementation
43 //===----------------------------------------------------------------------===//
44 
45 bool CodeCompletionContext::wantConstructorResults() const {
46   switch (CCKind) {
47   case CCC_Recovery:
48   case CCC_Statement:
49   case CCC_Expression:
50   case CCC_ObjCMessageReceiver:
51   case CCC_ParenthesizedExpression:
52   case CCC_Symbol:
53   case CCC_SymbolOrNewName:
54     return true;
55 
56   case CCC_TopLevel:
57   case CCC_ObjCInterface:
58   case CCC_ObjCImplementation:
59   case CCC_ObjCIvarList:
60   case CCC_ClassStructUnion:
61   case CCC_DotMemberAccess:
62   case CCC_ArrowMemberAccess:
63   case CCC_ObjCPropertyAccess:
64   case CCC_EnumTag:
65   case CCC_UnionTag:
66   case CCC_ClassOrStructTag:
67   case CCC_ObjCProtocolName:
68   case CCC_Namespace:
69   case CCC_Type:
70   case CCC_NewName:
71   case CCC_MacroName:
72   case CCC_MacroNameUse:
73   case CCC_PreprocessorExpression:
74   case CCC_PreprocessorDirective:
75   case CCC_NaturalLanguage:
76   case CCC_SelectorName:
77   case CCC_TypeQualifiers:
78   case CCC_Other:
79   case CCC_OtherWithMacros:
80   case CCC_ObjCInstanceMessage:
81   case CCC_ObjCClassMessage:
82   case CCC_ObjCInterfaceName:
83   case CCC_ObjCCategoryName:
84   case CCC_IncludedFile:
85     return false;
86   }
87 
88   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
89 }
90 
91 StringRef clang::getCompletionKindString(CodeCompletionContext::Kind Kind) {
92   using CCKind = CodeCompletionContext::Kind;
93   switch (Kind) {
94   case CCKind::CCC_Other:
95     return "Other";
96   case CCKind::CCC_OtherWithMacros:
97     return "OtherWithMacros";
98   case CCKind::CCC_TopLevel:
99     return "TopLevel";
100   case CCKind::CCC_ObjCInterface:
101     return "ObjCInterface";
102   case CCKind::CCC_ObjCImplementation:
103     return "ObjCImplementation";
104   case CCKind::CCC_ObjCIvarList:
105     return "ObjCIvarList";
106   case CCKind::CCC_ClassStructUnion:
107     return "ClassStructUnion";
108   case CCKind::CCC_Statement:
109     return "Statement";
110   case CCKind::CCC_Expression:
111     return "Expression";
112   case CCKind::CCC_ObjCMessageReceiver:
113     return "ObjCMessageReceiver";
114   case CCKind::CCC_DotMemberAccess:
115     return "DotMemberAccess";
116   case CCKind::CCC_ArrowMemberAccess:
117     return "ArrowMemberAccess";
118   case CCKind::CCC_ObjCPropertyAccess:
119     return "ObjCPropertyAccess";
120   case CCKind::CCC_EnumTag:
121     return "EnumTag";
122   case CCKind::CCC_UnionTag:
123     return "UnionTag";
124   case CCKind::CCC_ClassOrStructTag:
125     return "ClassOrStructTag";
126   case CCKind::CCC_ObjCProtocolName:
127     return "ObjCProtocolName";
128   case CCKind::CCC_Namespace:
129     return "Namespace";
130   case CCKind::CCC_Type:
131     return "Type";
132   case CCKind::CCC_NewName:
133     return "NewName";
134   case CCKind::CCC_Symbol:
135     return "Symbol";
136   case CCKind::CCC_SymbolOrNewName:
137     return "SymbolOrNewName";
138   case CCKind::CCC_MacroName:
139     return "MacroName";
140   case CCKind::CCC_MacroNameUse:
141     return "MacroNameUse";
142   case CCKind::CCC_PreprocessorExpression:
143     return "PreprocessorExpression";
144   case CCKind::CCC_PreprocessorDirective:
145     return "PreprocessorDirective";
146   case CCKind::CCC_NaturalLanguage:
147     return "NaturalLanguage";
148   case CCKind::CCC_SelectorName:
149     return "SelectorName";
150   case CCKind::CCC_TypeQualifiers:
151     return "TypeQualifiers";
152   case CCKind::CCC_ParenthesizedExpression:
153     return "ParenthesizedExpression";
154   case CCKind::CCC_ObjCInstanceMessage:
155     return "ObjCInstanceMessage";
156   case CCKind::CCC_ObjCClassMessage:
157     return "ObjCClassMessage";
158   case CCKind::CCC_ObjCInterfaceName:
159     return "ObjCInterfaceName";
160   case CCKind::CCC_ObjCCategoryName:
161     return "ObjCCategoryName";
162   case CCKind::CCC_IncludedFile:
163     return "IncludedFile";
164   case CCKind::CCC_Recovery:
165     return "Recovery";
166   }
167   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
168 }
169 
170 //===----------------------------------------------------------------------===//
171 // Code completion string implementation
172 //===----------------------------------------------------------------------===//
173 
174 CodeCompletionString::Chunk::Chunk(ChunkKind Kind, const char *Text)
175     : Kind(Kind), Text("") {
176   switch (Kind) {
177   case CK_TypedText:
178   case CK_Text:
179   case CK_Placeholder:
180   case CK_Informative:
181   case CK_ResultType:
182   case CK_CurrentParameter:
183     this->Text = Text;
184     break;
185 
186   case CK_Optional:
187     llvm_unreachable("Optional strings cannot be created from text");
188 
189   case CK_LeftParen:
190     this->Text = "(";
191     break;
192 
193   case CK_RightParen:
194     this->Text = ")";
195     break;
196 
197   case CK_LeftBracket:
198     this->Text = "[";
199     break;
200 
201   case CK_RightBracket:
202     this->Text = "]";
203     break;
204 
205   case CK_LeftBrace:
206     this->Text = "{";
207     break;
208 
209   case CK_RightBrace:
210     this->Text = "}";
211     break;
212 
213   case CK_LeftAngle:
214     this->Text = "<";
215     break;
216 
217   case CK_RightAngle:
218     this->Text = ">";
219     break;
220 
221   case CK_Comma:
222     this->Text = ", ";
223     break;
224 
225   case CK_Colon:
226     this->Text = ":";
227     break;
228 
229   case CK_SemiColon:
230     this->Text = ";";
231     break;
232 
233   case CK_Equal:
234     this->Text = " = ";
235     break;
236 
237   case CK_HorizontalSpace:
238     this->Text = " ";
239     break;
240 
241   case CK_VerticalSpace:
242     this->Text = "\n";
243     break;
244   }
245 }
246 
247 CodeCompletionString::Chunk
248 CodeCompletionString::Chunk::CreateText(const char *Text) {
249   return Chunk(CK_Text, Text);
250 }
251 
252 CodeCompletionString::Chunk
253 CodeCompletionString::Chunk::CreateOptional(CodeCompletionString *Optional) {
254   Chunk Result;
255   Result.Kind = CK_Optional;
256   Result.Optional = Optional;
257   return Result;
258 }
259 
260 CodeCompletionString::Chunk
261 CodeCompletionString::Chunk::CreatePlaceholder(const char *Placeholder) {
262   return Chunk(CK_Placeholder, Placeholder);
263 }
264 
265 CodeCompletionString::Chunk
266 CodeCompletionString::Chunk::CreateInformative(const char *Informative) {
267   return Chunk(CK_Informative, Informative);
268 }
269 
270 CodeCompletionString::Chunk
271 CodeCompletionString::Chunk::CreateResultType(const char *ResultType) {
272   return Chunk(CK_ResultType, ResultType);
273 }
274 
275 CodeCompletionString::Chunk
276 CodeCompletionString::Chunk::CreateCurrentParameter(
277                                                 const char *CurrentParameter) {
278   return Chunk(CK_CurrentParameter, CurrentParameter);
279 }
280 
281 CodeCompletionString::CodeCompletionString(const Chunk *Chunks,
282                                            unsigned NumChunks,
283                                            unsigned Priority,
284                                            CXAvailabilityKind Availability,
285                                            const char **Annotations,
286                                            unsigned NumAnnotations,
287                                            StringRef ParentName,
288                                            const char *BriefComment)
289     : NumChunks(NumChunks), NumAnnotations(NumAnnotations),
290       Priority(Priority), Availability(Availability),
291       ParentName(ParentName), BriefComment(BriefComment) {
292   assert(NumChunks <= 0xffff);
293   assert(NumAnnotations <= 0xffff);
294 
295   Chunk *StoredChunks = reinterpret_cast<Chunk *>(this + 1);
296   for (unsigned I = 0; I != NumChunks; ++I)
297     StoredChunks[I] = Chunks[I];
298 
299   const char **StoredAnnotations = reinterpret_cast<const char **>(StoredChunks + NumChunks);
300   for (unsigned I = 0; I != NumAnnotations; ++I)
301     StoredAnnotations[I] = Annotations[I];
302 }
303 
304 unsigned CodeCompletionString::getAnnotationCount() const {
305   return NumAnnotations;
306 }
307 
308 const char *CodeCompletionString::getAnnotation(unsigned AnnotationNr) const {
309   if (AnnotationNr < NumAnnotations)
310     return reinterpret_cast<const char * const*>(end())[AnnotationNr];
311   else
312     return nullptr;
313 }
314 
315 std::string CodeCompletionString::getAsString() const {
316   std::string Result;
317   llvm::raw_string_ostream OS(Result);
318 
319   for (iterator C = begin(), CEnd = end(); C != CEnd; ++C) {
320     switch (C->Kind) {
321     case CK_Optional: OS << "{#" << C->Optional->getAsString() << "#}"; break;
322     case CK_Placeholder: OS << "<#" << C->Text << "#>"; break;
323 
324     case CK_Informative:
325     case CK_ResultType:
326       OS << "[#" << C->Text << "#]";
327       break;
328 
329     case CK_CurrentParameter: OS << "<#" << C->Text << "#>"; break;
330     default: OS << C->Text; break;
331     }
332   }
333   return OS.str();
334 }
335 
336 const char *CodeCompletionString::getTypedText() const {
337   for (iterator C = begin(), CEnd = end(); C != CEnd; ++C)
338     if (C->Kind == CK_TypedText)
339       return C->Text;
340 
341   return nullptr;
342 }
343 
344 const char *CodeCompletionAllocator::CopyString(const Twine &String) {
345   SmallString<128> Data;
346   StringRef Ref = String.toStringRef(Data);
347   // FIXME: It would be more efficient to teach Twine to tell us its size and
348   // then add a routine there to fill in an allocated char* with the contents
349   // of the string.
350   char *Mem = (char *)Allocate(Ref.size() + 1, 1);
351   std::copy(Ref.begin(), Ref.end(), Mem);
352   Mem[Ref.size()] = 0;
353   return Mem;
354 }
355 
356 StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
357   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
358   if (!ND)
359     return {};
360 
361   // Check whether we've already cached the parent name.
362   StringRef &CachedParentName = ParentNames[DC];
363   if (!CachedParentName.empty())
364     return CachedParentName;
365 
366   // If we already processed this DeclContext and assigned empty to it, the
367   // data pointer will be non-null.
368   if (CachedParentName.data() != nullptr)
369     return {};
370 
371   // Find the interesting names.
372   SmallVector<const DeclContext *, 2> Contexts;
373   while (DC && !DC->isFunctionOrMethod()) {
374     if (const NamedDecl *ND = dyn_cast<NamedDecl>(DC)) {
375       if (ND->getIdentifier())
376         Contexts.push_back(DC);
377     }
378 
379     DC = DC->getParent();
380   }
381 
382   {
383     SmallString<128> S;
384     llvm::raw_svector_ostream OS(S);
385     bool First = true;
386     for (unsigned I = Contexts.size(); I != 0; --I) {
387       if (First)
388         First = false;
389       else {
390         OS << "::";
391       }
392 
393       const DeclContext *CurDC = Contexts[I-1];
394       if (const ObjCCategoryImplDecl *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
395         CurDC = CatImpl->getCategoryDecl();
396 
397       if (const ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
398         const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
399         if (!Interface) {
400           // Assign an empty StringRef but with non-null data to distinguish
401           // between empty because we didn't process the DeclContext yet.
402           CachedParentName = StringRef((const char *)(uintptr_t)~0U, 0);
403           return {};
404         }
405 
406         OS << Interface->getName() << '(' << Cat->getName() << ')';
407       } else {
408         OS << cast<NamedDecl>(CurDC)->getName();
409       }
410     }
411 
412     CachedParentName = AllocatorRef->CopyString(OS.str());
413   }
414 
415   return CachedParentName;
416 }
417 
418 CodeCompletionString *CodeCompletionBuilder::TakeString() {
419   void *Mem = getAllocator().Allocate(
420       sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size() +
421           sizeof(const char *) * Annotations.size(),
422       alignof(CodeCompletionString));
423   CodeCompletionString *Result
424     = new (Mem) CodeCompletionString(Chunks.data(), Chunks.size(),
425                                      Priority, Availability,
426                                      Annotations.data(), Annotations.size(),
427                                      ParentName, BriefComment);
428   Chunks.clear();
429   return Result;
430 }
431 
432 void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
433   Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
434 }
435 
436 void CodeCompletionBuilder::AddTextChunk(const char *Text) {
437   Chunks.push_back(Chunk::CreateText(Text));
438 }
439 
440 void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
441   Chunks.push_back(Chunk::CreateOptional(Optional));
442 }
443 
444 void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
445   Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
446 }
447 
448 void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
449   Chunks.push_back(Chunk::CreateInformative(Text));
450 }
451 
452 void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
453   Chunks.push_back(Chunk::CreateResultType(ResultType));
454 }
455 
456 void
457 CodeCompletionBuilder::AddCurrentParameterChunk(const char *CurrentParameter) {
458   Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
459 }
460 
461 void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
462                                      const char *Text) {
463   Chunks.push_back(Chunk(CK, Text));
464 }
465 
466 void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
467   if (DC->isTranslationUnit())
468     return;
469 
470   if (DC->isFunctionOrMethod())
471     return;
472 
473   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
474   if (!ND)
475     return;
476 
477   ParentName = getCodeCompletionTUInfo().getParentName(DC);
478 }
479 
480 void CodeCompletionBuilder::addBriefComment(StringRef Comment) {
481   BriefComment = Allocator.CopyString(Comment);
482 }
483 
484 //===----------------------------------------------------------------------===//
485 // Code completion overload candidate implementation
486 //===----------------------------------------------------------------------===//
487 FunctionDecl *
488 CodeCompleteConsumer::OverloadCandidate::getFunction() const {
489   if (getKind() == CK_Function)
490     return Function;
491   else if (getKind() == CK_FunctionTemplate)
492     return FunctionTemplate->getTemplatedDecl();
493   else
494     return nullptr;
495 }
496 
497 const FunctionType *
498 CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
499   switch (Kind) {
500   case CK_Function:
501     return Function->getType()->getAs<FunctionType>();
502 
503   case CK_FunctionTemplate:
504     return FunctionTemplate->getTemplatedDecl()->getType()
505              ->getAs<FunctionType>();
506 
507   case CK_FunctionType:
508     return Type;
509   }
510 
511   llvm_unreachable("Invalid CandidateKind!");
512 }
513 
514 //===----------------------------------------------------------------------===//
515 // Code completion consumer implementation
516 //===----------------------------------------------------------------------===//
517 
518 CodeCompleteConsumer::~CodeCompleteConsumer() = default;
519 
520 bool PrintingCodeCompleteConsumer::isResultFilteredOut(StringRef Filter,
521                                                 CodeCompletionResult Result) {
522   switch (Result.Kind) {
523   case CodeCompletionResult::RK_Declaration:
524     return !(Result.Declaration->getIdentifier() &&
525             Result.Declaration->getIdentifier()->getName().startswith(Filter));
526   case CodeCompletionResult::RK_Keyword:
527     return !StringRef(Result.Keyword).startswith(Filter);
528   case CodeCompletionResult::RK_Macro:
529     return !Result.Macro->getName().startswith(Filter);
530   case CodeCompletionResult::RK_Pattern:
531     return !(Result.Pattern->getTypedText() &&
532              StringRef(Result.Pattern->getTypedText()).startswith(Filter));
533   }
534   llvm_unreachable("Unknown code completion result Kind.");
535 }
536 
537 void
538 PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &SemaRef,
539                                                  CodeCompletionContext Context,
540                                                  CodeCompletionResult *Results,
541                                                          unsigned NumResults) {
542   std::stable_sort(Results, Results + NumResults);
543 
544   StringRef Filter = SemaRef.getPreprocessor().getCodeCompletionFilter();
545 
546   // Print the results.
547   for (unsigned I = 0; I != NumResults; ++I) {
548     if(!Filter.empty() && isResultFilteredOut(Filter, Results[I]))
549       continue;
550     OS << "COMPLETION: ";
551     switch (Results[I].Kind) {
552     case CodeCompletionResult::RK_Declaration:
553       OS << *Results[I].Declaration;
554       {
555         std::vector<std::string> Tags;
556         if (Results[I].Hidden)
557           Tags.push_back("Hidden");
558         if (Results[I].InBaseClass)
559           Tags.push_back("InBase");
560         if (!Tags.empty())
561           OS << " (" << llvm::join(Tags, ",") << ")";
562       }
563       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
564               SemaRef, Context, getAllocator(), CCTUInfo,
565               includeBriefComments())) {
566         OS << " : " << CCS->getAsString();
567         if (const char *BriefComment = CCS->getBriefComment())
568           OS << " : " << BriefComment;
569       }
570       for (const FixItHint &FixIt : Results[I].FixIts) {
571         const SourceLocation BLoc = FixIt.RemoveRange.getBegin();
572         const SourceLocation ELoc = FixIt.RemoveRange.getEnd();
573 
574         SourceManager &SM = SemaRef.SourceMgr;
575         std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(BLoc);
576         std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(ELoc);
577         // Adjust for token ranges.
578         if (FixIt.RemoveRange.isTokenRange())
579           EInfo.second += Lexer::MeasureTokenLength(ELoc, SM, SemaRef.LangOpts);
580 
581         OS << " (requires fix-it:"
582            << " {" << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
583            << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
584            << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
585            << SM.getColumnNumber(EInfo.first, EInfo.second) << "}"
586            << " to \"" << FixIt.CodeToInsert << "\")";
587       }
588       OS << '\n';
589       break;
590 
591     case CodeCompletionResult::RK_Keyword:
592       OS << Results[I].Keyword << '\n';
593       break;
594 
595     case CodeCompletionResult::RK_Macro:
596       OS << Results[I].Macro->getName();
597       if (CodeCompletionString *CCS
598             = Results[I].CreateCodeCompletionString(SemaRef, Context,
599                                                     getAllocator(),
600                                                     CCTUInfo,
601                                                     includeBriefComments())) {
602         OS << " : " << CCS->getAsString();
603       }
604       OS << '\n';
605       break;
606 
607     case CodeCompletionResult::RK_Pattern:
608       OS << "Pattern : "
609          << Results[I].Pattern->getAsString() << '\n';
610       break;
611     }
612   }
613 }
614 
615 // This function is used solely to preserve the former presentation of overloads
616 // by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
617 // needs to be improved for printing the newer and more detailed overload
618 // chunks.
619 static std::string getOverloadAsString(const CodeCompletionString &CCS) {
620   std::string Result;
621   llvm::raw_string_ostream OS(Result);
622 
623   for (auto &C : CCS) {
624     switch (C.Kind) {
625     case CodeCompletionString::CK_Informative:
626     case CodeCompletionString::CK_ResultType:
627       OS << "[#" << C.Text << "#]";
628       break;
629 
630     case CodeCompletionString::CK_CurrentParameter:
631       OS << "<#" << C.Text << "#>";
632       break;
633 
634     // FIXME: We can also print optional parameters of an overload.
635     case CodeCompletionString::CK_Optional:
636       break;
637 
638     default: OS << C.Text; break;
639     }
640   }
641   return OS.str();
642 }
643 
644 void PrintingCodeCompleteConsumer::ProcessOverloadCandidates(
645     Sema &SemaRef, unsigned CurrentArg, OverloadCandidate *Candidates,
646     unsigned NumCandidates, SourceLocation OpenParLoc) {
647   OS << "OPENING_PAREN_LOC: ";
648   OpenParLoc.print(OS, SemaRef.getSourceManager());
649   OS << "\n";
650 
651   for (unsigned I = 0; I != NumCandidates; ++I) {
652     if (CodeCompletionString *CCS = Candidates[I].CreateSignatureString(
653             CurrentArg, SemaRef, getAllocator(), CCTUInfo,
654             includeBriefComments())) {
655       OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
656     }
657   }
658 }
659 
660 /// Retrieve the effective availability of the given declaration.
661 static AvailabilityResult getDeclAvailability(const Decl *D) {
662   AvailabilityResult AR = D->getAvailability();
663   if (isa<EnumConstantDecl>(D))
664     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
665   return AR;
666 }
667 
668 void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
669   switch (Kind) {
670   case RK_Pattern:
671     if (!Declaration) {
672       // Do nothing: Patterns can come with cursor kinds!
673       break;
674     }
675     LLVM_FALLTHROUGH;
676 
677   case RK_Declaration: {
678     // Set the availability based on attributes.
679     switch (getDeclAvailability(Declaration)) {
680     case AR_Available:
681     case AR_NotYetIntroduced:
682       Availability = CXAvailability_Available;
683       break;
684 
685     case AR_Deprecated:
686       Availability = CXAvailability_Deprecated;
687       break;
688 
689     case AR_Unavailable:
690       Availability = CXAvailability_NotAvailable;
691       break;
692     }
693 
694     if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Declaration))
695       if (Function->isDeleted())
696         Availability = CXAvailability_NotAvailable;
697 
698     CursorKind = getCursorKindForDecl(Declaration);
699     if (CursorKind == CXCursor_UnexposedDecl) {
700       // FIXME: Forward declarations of Objective-C classes and protocols
701       // are not directly exposed, but we want code completion to treat them
702       // like a definition.
703       if (isa<ObjCInterfaceDecl>(Declaration))
704         CursorKind = CXCursor_ObjCInterfaceDecl;
705       else if (isa<ObjCProtocolDecl>(Declaration))
706         CursorKind = CXCursor_ObjCProtocolDecl;
707       else
708         CursorKind = CXCursor_NotImplemented;
709     }
710     break;
711   }
712 
713   case RK_Macro:
714   case RK_Keyword:
715     llvm_unreachable("Macro and keyword kinds are handled by the constructors");
716   }
717 
718   if (!Accessible)
719     Availability = CXAvailability_NotAccessible;
720 }
721 
722 /// Retrieve the name that should be used to order a result.
723 ///
724 /// If the name needs to be constructed as a string, that string will be
725 /// saved into Saved and the returned StringRef will refer to it.
726 StringRef CodeCompletionResult::getOrderedName(std::string &Saved) const {
727   switch (Kind) {
728     case RK_Keyword:
729       return Keyword;
730     case RK_Pattern:
731       return Pattern->getTypedText();
732     case RK_Macro:
733       return Macro->getName();
734     case RK_Declaration:
735       // Handle declarations below.
736       break;
737   }
738 
739   DeclarationName Name = Declaration->getDeclName();
740 
741   // If the name is a simple identifier (by far the common case), or a
742   // zero-argument selector, just return a reference to that identifier.
743   if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
744     return Id->getName();
745   if (Name.isObjCZeroArgSelector())
746     if (IdentifierInfo *Id
747         = Name.getObjCSelector().getIdentifierInfoForSlot(0))
748       return Id->getName();
749 
750   Saved = Name.getAsString();
751   return Saved;
752 }
753 
754 bool clang::operator<(const CodeCompletionResult &X,
755                       const CodeCompletionResult &Y) {
756   std::string XSaved, YSaved;
757   StringRef XStr = X.getOrderedName(XSaved);
758   StringRef YStr = Y.getOrderedName(YSaved);
759   int cmp = XStr.compare_lower(YStr);
760   if (cmp)
761     return cmp < 0;
762 
763   // If case-insensitive comparison fails, try case-sensitive comparison.
764   cmp = XStr.compare(YStr);
765   if (cmp)
766     return cmp < 0;
767 
768   return false;
769 }
770