xref: /llvm-project/clang/lib/Sema/CodeCompleteConsumer.cpp (revision a76e68c9704fb5b3faf25bb8d51e405b5310ff08) 
1 //===- CodeCompleteConsumer.cpp - Code Completion Interface ---------------===//
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 //  This file implements the CodeCompleteConsumer class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/Sema/CodeCompleteConsumer.h"
14 #include "clang-c/Index.h"
15 #include "clang/AST/Decl.h"
16 #include "clang/AST/DeclBase.h"
17 #include "clang/AST/DeclObjC.h"
18 #include "clang/AST/DeclTemplate.h"
19 #include "clang/AST/DeclarationName.h"
20 #include "clang/AST/Type.h"
21 #include "clang/Basic/IdentifierTable.h"
22 #include "clang/Lex/Preprocessor.h"
23 #include "clang/Sema/Sema.h"
24 #include "llvm/ADT/SmallString.h"
25 #include "llvm/ADT/SmallVector.h"
26 #include "llvm/ADT/StringRef.h"
27 #include "llvm/ADT/Twine.h"
28 #include "llvm/Support/Casting.h"
29 #include "llvm/Support/Compiler.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/FormatVariadic.h"
32 #include "llvm/Support/raw_ostream.h"
33 #include <algorithm>
34 #include <cassert>
35 #include <cstdint>
36 #include <string>
37 
38 using namespace clang;
39 
40 //===----------------------------------------------------------------------===//
41 // Code completion context implementation
42 //===----------------------------------------------------------------------===//
43 
44 bool CodeCompletionContext::wantConstructorResults() const {
45   switch (CCKind) {
46   case CCC_Recovery:
47   case CCC_Statement:
48   case CCC_Expression:
49   case CCC_ObjCMessageReceiver:
50   case CCC_ParenthesizedExpression:
51   case CCC_Symbol:
52   case CCC_SymbolOrNewName:
53     return true;
54 
55   case CCC_TopLevel:
56   case CCC_ObjCInterface:
57   case CCC_ObjCImplementation:
58   case CCC_ObjCIvarList:
59   case CCC_ClassStructUnion:
60   case CCC_DotMemberAccess:
61   case CCC_ArrowMemberAccess:
62   case CCC_ObjCPropertyAccess:
63   case CCC_EnumTag:
64   case CCC_UnionTag:
65   case CCC_ClassOrStructTag:
66   case CCC_ObjCProtocolName:
67   case CCC_Namespace:
68   case CCC_Type:
69   case CCC_NewName:
70   case CCC_MacroName:
71   case CCC_MacroNameUse:
72   case CCC_PreprocessorExpression:
73   case CCC_PreprocessorDirective:
74   case CCC_NaturalLanguage:
75   case CCC_SelectorName:
76   case CCC_TypeQualifiers:
77   case CCC_Other:
78   case CCC_OtherWithMacros:
79   case CCC_ObjCInstanceMessage:
80   case CCC_ObjCClassMessage:
81   case CCC_ObjCInterfaceName:
82   case CCC_ObjCCategoryName:
83   case CCC_IncludedFile:
84     return false;
85   }
86 
87   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
88 }
89 
90 StringRef clang::getCompletionKindString(CodeCompletionContext::Kind Kind) {
91   using CCKind = CodeCompletionContext::Kind;
92   switch (Kind) {
93   case CCKind::CCC_Other:
94     return "Other";
95   case CCKind::CCC_OtherWithMacros:
96     return "OtherWithMacros";
97   case CCKind::CCC_TopLevel:
98     return "TopLevel";
99   case CCKind::CCC_ObjCInterface:
100     return "ObjCInterface";
101   case CCKind::CCC_ObjCImplementation:
102     return "ObjCImplementation";
103   case CCKind::CCC_ObjCIvarList:
104     return "ObjCIvarList";
105   case CCKind::CCC_ClassStructUnion:
106     return "ClassStructUnion";
107   case CCKind::CCC_Statement:
108     return "Statement";
109   case CCKind::CCC_Expression:
110     return "Expression";
111   case CCKind::CCC_ObjCMessageReceiver:
112     return "ObjCMessageReceiver";
113   case CCKind::CCC_DotMemberAccess:
114     return "DotMemberAccess";
115   case CCKind::CCC_ArrowMemberAccess:
116     return "ArrowMemberAccess";
117   case CCKind::CCC_ObjCPropertyAccess:
118     return "ObjCPropertyAccess";
119   case CCKind::CCC_EnumTag:
120     return "EnumTag";
121   case CCKind::CCC_UnionTag:
122     return "UnionTag";
123   case CCKind::CCC_ClassOrStructTag:
124     return "ClassOrStructTag";
125   case CCKind::CCC_ObjCProtocolName:
126     return "ObjCProtocolName";
127   case CCKind::CCC_Namespace:
128     return "Namespace";
129   case CCKind::CCC_Type:
130     return "Type";
131   case CCKind::CCC_NewName:
132     return "NewName";
133   case CCKind::CCC_Symbol:
134     return "Symbol";
135   case CCKind::CCC_SymbolOrNewName:
136     return "SymbolOrNewName";
137   case CCKind::CCC_MacroName:
138     return "MacroName";
139   case CCKind::CCC_MacroNameUse:
140     return "MacroNameUse";
141   case CCKind::CCC_PreprocessorExpression:
142     return "PreprocessorExpression";
143   case CCKind::CCC_PreprocessorDirective:
144     return "PreprocessorDirective";
145   case CCKind::CCC_NaturalLanguage:
146     return "NaturalLanguage";
147   case CCKind::CCC_SelectorName:
148     return "SelectorName";
149   case CCKind::CCC_TypeQualifiers:
150     return "TypeQualifiers";
151   case CCKind::CCC_ParenthesizedExpression:
152     return "ParenthesizedExpression";
153   case CCKind::CCC_ObjCInstanceMessage:
154     return "ObjCInstanceMessage";
155   case CCKind::CCC_ObjCClassMessage:
156     return "ObjCClassMessage";
157   case CCKind::CCC_ObjCInterfaceName:
158     return "ObjCInterfaceName";
159   case CCKind::CCC_ObjCCategoryName:
160     return "ObjCCategoryName";
161   case CCKind::CCC_IncludedFile:
162     return "IncludedFile";
163   case CCKind::CCC_Recovery:
164     return "Recovery";
165   }
166   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
167 }
168 
169 //===----------------------------------------------------------------------===//
170 // Code completion string implementation
171 //===----------------------------------------------------------------------===//
172 
173 CodeCompletionString::Chunk::Chunk(ChunkKind Kind, const char *Text)
174     : Kind(Kind), Text("") {
175   switch (Kind) {
176   case CK_TypedText:
177   case CK_Text:
178   case CK_Placeholder:
179   case CK_Informative:
180   case CK_ResultType:
181   case CK_CurrentParameter:
182     this->Text = Text;
183     break;
184 
185   case CK_Optional:
186     llvm_unreachable("Optional strings cannot be created from text");
187 
188   case CK_LeftParen:
189     this->Text = "(";
190     break;
191 
192   case CK_RightParen:
193     this->Text = ")";
194     break;
195 
196   case CK_LeftBracket:
197     this->Text = "[";
198     break;
199 
200   case CK_RightBracket:
201     this->Text = "]";
202     break;
203 
204   case CK_LeftBrace:
205     this->Text = "{";
206     break;
207 
208   case CK_RightBrace:
209     this->Text = "}";
210     break;
211 
212   case CK_LeftAngle:
213     this->Text = "<";
214     break;
215 
216   case CK_RightAngle:
217     this->Text = ">";
218     break;
219 
220   case CK_Comma:
221     this->Text = ", ";
222     break;
223 
224   case CK_Colon:
225     this->Text = ":";
226     break;
227 
228   case CK_SemiColon:
229     this->Text = ";";
230     break;
231 
232   case CK_Equal:
233     this->Text = " = ";
234     break;
235 
236   case CK_HorizontalSpace:
237     this->Text = " ";
238     break;
239 
240   case CK_VerticalSpace:
241     this->Text = "\n";
242     break;
243   }
244 }
245 
246 CodeCompletionString::Chunk
247 CodeCompletionString::Chunk::CreateText(const char *Text) {
248   return Chunk(CK_Text, Text);
249 }
250 
251 CodeCompletionString::Chunk
252 CodeCompletionString::Chunk::CreateOptional(CodeCompletionString *Optional) {
253   Chunk Result;
254   Result.Kind = CK_Optional;
255   Result.Optional = Optional;
256   return Result;
257 }
258 
259 CodeCompletionString::Chunk
260 CodeCompletionString::Chunk::CreatePlaceholder(const char *Placeholder) {
261   return Chunk(CK_Placeholder, Placeholder);
262 }
263 
264 CodeCompletionString::Chunk
265 CodeCompletionString::Chunk::CreateInformative(const char *Informative) {
266   return Chunk(CK_Informative, Informative);
267 }
268 
269 CodeCompletionString::Chunk
270 CodeCompletionString::Chunk::CreateResultType(const char *ResultType) {
271   return Chunk(CK_ResultType, ResultType);
272 }
273 
274 CodeCompletionString::Chunk CodeCompletionString::Chunk::CreateCurrentParameter(
275     const char *CurrentParameter) {
276   return Chunk(CK_CurrentParameter, CurrentParameter);
277 }
278 
279 CodeCompletionString::CodeCompletionString(
280     const Chunk *Chunks, unsigned NumChunks, unsigned Priority,
281     CXAvailabilityKind Availability, const char **Annotations,
282     unsigned NumAnnotations, StringRef ParentName, const char *BriefComment)
283     : NumChunks(NumChunks), NumAnnotations(NumAnnotations), Priority(Priority),
284       Availability(Availability), ParentName(ParentName),
285       BriefComment(BriefComment) {
286   assert(NumChunks <= 0xffff);
287   assert(NumAnnotations <= 0xffff);
288 
289   Chunk *StoredChunks = reinterpret_cast<Chunk *>(this + 1);
290   for (unsigned I = 0; I != NumChunks; ++I)
291     StoredChunks[I] = Chunks[I];
292 
293   const char **StoredAnnotations =
294       reinterpret_cast<const char **>(StoredChunks + NumChunks);
295   for (unsigned I = 0; I != NumAnnotations; ++I)
296     StoredAnnotations[I] = Annotations[I];
297 }
298 
299 unsigned CodeCompletionString::getAnnotationCount() const {
300   return NumAnnotations;
301 }
302 
303 const char *CodeCompletionString::getAnnotation(unsigned AnnotationNr) const {
304   if (AnnotationNr < NumAnnotations)
305     return reinterpret_cast<const char *const *>(end())[AnnotationNr];
306   else
307     return nullptr;
308 }
309 
310 std::string CodeCompletionString::getAsString() const {
311   std::string Result;
312   llvm::raw_string_ostream OS(Result);
313 
314   for (const Chunk &C : *this) {
315     switch (C.Kind) {
316     case CK_Optional:
317       OS << "{#" << C.Optional->getAsString() << "#}";
318       break;
319     case CK_Placeholder:
320       OS << "<#" << C.Text << "#>";
321       break;
322     case CK_Informative:
323     case CK_ResultType:
324       OS << "[#" << C.Text << "#]";
325       break;
326     case CK_CurrentParameter:
327       OS << "<#" << C.Text << "#>";
328       break;
329     default:
330       OS << C.Text;
331       break;
332     }
333   }
334   return OS.str();
335 }
336 
337 const char *CodeCompletionString::getTypedText() const {
338   for (const Chunk &C : *this)
339     if (C.Kind == CK_TypedText)
340       return C.Text;
341 
342   return nullptr;
343 }
344 
345 const char *CodeCompletionAllocator::CopyString(const Twine &String) {
346   SmallString<128> Data;
347   StringRef Ref = String.toStringRef(Data);
348   // FIXME: It would be more efficient to teach Twine to tell us its size and
349   // then add a routine there to fill in an allocated char* with the contents
350   // of the string.
351   char *Mem = (char *)Allocate(Ref.size() + 1, 1);
352   std::copy(Ref.begin(), Ref.end(), Mem);
353   Mem[Ref.size()] = 0;
354   return Mem;
355 }
356 
357 StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
358   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
359   if (!ND)
360     return {};
361 
362   // Check whether we've already cached the parent name.
363   StringRef &CachedParentName = ParentNames[DC];
364   if (!CachedParentName.empty())
365     return CachedParentName;
366 
367   // If we already processed this DeclContext and assigned empty to it, the
368   // data pointer will be non-null.
369   if (CachedParentName.data() != nullptr)
370     return {};
371 
372   // Find the interesting names.
373   SmallVector<const DeclContext *, 2> Contexts;
374   while (DC && !DC->isFunctionOrMethod()) {
375     if (const auto *ND = dyn_cast<NamedDecl>(DC)) {
376       if (ND->getIdentifier())
377         Contexts.push_back(DC);
378     }
379 
380     DC = DC->getParent();
381   }
382 
383   {
384     SmallString<128> S;
385     llvm::raw_svector_ostream OS(S);
386     bool First = true;
387     for (unsigned I = Contexts.size(); I != 0; --I) {
388       if (First)
389         First = false;
390       else {
391         OS << "::";
392       }
393 
394       const DeclContext *CurDC = Contexts[I - 1];
395       if (const auto *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
396         CurDC = CatImpl->getCategoryDecl();
397 
398       if (const auto *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
399         const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
400         if (!Interface) {
401           // Assign an empty StringRef but with non-null data to distinguish
402           // between empty because we didn't process the DeclContext yet.
403           CachedParentName = StringRef((const char *)(uintptr_t)~0U, 0);
404           return {};
405         }
406 
407         OS << Interface->getName() << '(' << Cat->getName() << ')';
408       } else {
409         OS << cast<NamedDecl>(CurDC)->getName();
410       }
411     }
412 
413     CachedParentName = AllocatorRef->CopyString(OS.str());
414   }
415 
416   return CachedParentName;
417 }
418 
419 CodeCompletionString *CodeCompletionBuilder::TakeString() {
420   void *Mem = getAllocator().Allocate(
421       sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size() +
422           sizeof(const char *) * Annotations.size(),
423       alignof(CodeCompletionString));
424   CodeCompletionString *Result = new (Mem) CodeCompletionString(
425       Chunks.data(), Chunks.size(), Priority, Availability, Annotations.data(),
426       Annotations.size(), ParentName, BriefComment);
427   Chunks.clear();
428   return Result;
429 }
430 
431 void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
432   Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
433 }
434 
435 void CodeCompletionBuilder::AddTextChunk(const char *Text) {
436   Chunks.push_back(Chunk::CreateText(Text));
437 }
438 
439 void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
440   Chunks.push_back(Chunk::CreateOptional(Optional));
441 }
442 
443 void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
444   Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
445 }
446 
447 void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
448   Chunks.push_back(Chunk::CreateInformative(Text));
449 }
450 
451 void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
452   Chunks.push_back(Chunk::CreateResultType(ResultType));
453 }
454 
455 void CodeCompletionBuilder::AddCurrentParameterChunk(
456     const char *CurrentParameter) {
457   Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
458 }
459 
460 void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
461                                      const char *Text) {
462   Chunks.push_back(Chunk(CK, Text));
463 }
464 
465 void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
466   if (DC->isTranslationUnit())
467     return;
468 
469   if (DC->isFunctionOrMethod())
470     return;
471 
472   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
473   if (!ND)
474     return;
475 
476   ParentName = getCodeCompletionTUInfo().getParentName(DC);
477 }
478 
479 void CodeCompletionBuilder::addBriefComment(StringRef Comment) {
480   BriefComment = Allocator.CopyString(Comment);
481 }
482 
483 //===----------------------------------------------------------------------===//
484 // Code completion overload candidate implementation
485 //===----------------------------------------------------------------------===//
486 FunctionDecl *CodeCompleteConsumer::OverloadCandidate::getFunction() const {
487   if (getKind() == CK_Function)
488     return Function;
489   else if (getKind() == CK_FunctionTemplate)
490     return FunctionTemplate->getTemplatedDecl();
491   else
492     return nullptr;
493 }
494 
495 const FunctionType *
496 CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
497   switch (Kind) {
498   case CK_Function:
499     return Function->getType()->getAs<FunctionType>();
500 
501   case CK_FunctionTemplate:
502     return FunctionTemplate->getTemplatedDecl()
503         ->getType()
504         ->getAs<FunctionType>();
505 
506   case CK_FunctionType:
507     return Type;
508   }
509 
510   llvm_unreachable("Invalid CandidateKind!");
511 }
512 
513 //===----------------------------------------------------------------------===//
514 // Code completion consumer implementation
515 //===----------------------------------------------------------------------===//
516 
517 CodeCompleteConsumer::~CodeCompleteConsumer() = default;
518 
519 bool PrintingCodeCompleteConsumer::isResultFilteredOut(
520     StringRef Filter, CodeCompletionResult Result) {
521   switch (Result.Kind) {
522   case CodeCompletionResult::RK_Declaration:
523     return !(Result.Declaration->getIdentifier() &&
524              Result.Declaration->getIdentifier()->getName().startswith(Filter));
525   case CodeCompletionResult::RK_Keyword:
526     return !StringRef(Result.Keyword).startswith(Filter);
527   case CodeCompletionResult::RK_Macro:
528     return !Result.Macro->getName().startswith(Filter);
529   case CodeCompletionResult::RK_Pattern:
530     return !(Result.Pattern->getTypedText() &&
531              StringRef(Result.Pattern->getTypedText()).startswith(Filter));
532   }
533   llvm_unreachable("Unknown code completion result Kind.");
534 }
535 
536 void PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(
537     Sema &SemaRef, CodeCompletionContext Context, CodeCompletionResult *Results,
538     unsigned NumResults) {
539   std::stable_sort(Results, Results + NumResults);
540 
541   if (!Context.getPreferredType().isNull())
542     OS << "PREFERRED-TYPE: " << Context.getPreferredType().getAsString()
543        << "\n";
544 
545   StringRef Filter = SemaRef.getPreprocessor().getCodeCompletionFilter();
546   // Print the completions.
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 (Results[I].Availability ==
561             CXAvailabilityKind::CXAvailability_NotAccessible)
562           Tags.push_back("Inaccessible");
563         if (!Tags.empty())
564           OS << " (" << llvm::join(Tags, ",") << ")";
565       }
566       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
567               SemaRef, Context, getAllocator(), CCTUInfo,
568               includeBriefComments())) {
569         OS << " : " << CCS->getAsString();
570         if (const char *BriefComment = CCS->getBriefComment())
571           OS << " : " << BriefComment;
572       }
573       break;
574 
575     case CodeCompletionResult::RK_Keyword:
576       OS << Results[I].Keyword;
577       break;
578 
579     case CodeCompletionResult::RK_Macro:
580       OS << Results[I].Macro->getName();
581       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
582               SemaRef, Context, getAllocator(), CCTUInfo,
583               includeBriefComments())) {
584         OS << " : " << CCS->getAsString();
585       }
586       break;
587 
588     case CodeCompletionResult::RK_Pattern:
589       OS << "Pattern : " << Results[I].Pattern->getAsString();
590       break;
591     }
592     for (const FixItHint &FixIt : Results[I].FixIts) {
593       const SourceLocation BLoc = FixIt.RemoveRange.getBegin();
594       const SourceLocation ELoc = FixIt.RemoveRange.getEnd();
595 
596       SourceManager &SM = SemaRef.SourceMgr;
597       std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(BLoc);
598       std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(ELoc);
599       // Adjust for token ranges.
600       if (FixIt.RemoveRange.isTokenRange())
601         EInfo.second += Lexer::MeasureTokenLength(ELoc, SM, SemaRef.LangOpts);
602 
603       OS << " (requires fix-it:"
604          << " {" << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
605          << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
606          << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
607          << SM.getColumnNumber(EInfo.first, EInfo.second) << "}"
608          << " to \"" << FixIt.CodeToInsert << "\")";
609     }
610     OS << '\n';
611   }
612 }
613 
614 // This function is used solely to preserve the former presentation of overloads
615 // by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
616 // needs to be improved for printing the newer and more detailed overload
617 // chunks.
618 static std::string getOverloadAsString(const CodeCompletionString &CCS) {
619   std::string Result;
620   llvm::raw_string_ostream OS(Result);
621 
622   for (auto &C : CCS) {
623     switch (C.Kind) {
624     case CodeCompletionString::CK_Informative:
625     case CodeCompletionString::CK_ResultType:
626       OS << "[#" << C.Text << "#]";
627       break;
628 
629     case CodeCompletionString::CK_CurrentParameter:
630       OS << "<#" << C.Text << "#>";
631       break;
632 
633     // FIXME: We can also print optional parameters of an overload.
634     case CodeCompletionString::CK_Optional:
635       break;
636 
637     default:
638       OS << C.Text;
639       break;
640     }
641   }
642   return OS.str();
643 }
644 
645 void PrintingCodeCompleteConsumer::ProcessOverloadCandidates(
646     Sema &SemaRef, unsigned CurrentArg, OverloadCandidate *Candidates,
647     unsigned NumCandidates, SourceLocation OpenParLoc) {
648   OS << "OPENING_PAREN_LOC: ";
649   OpenParLoc.print(OS, SemaRef.getSourceManager());
650   OS << "\n";
651 
652   for (unsigned I = 0; I != NumCandidates; ++I) {
653     if (CodeCompletionString *CCS = Candidates[I].CreateSignatureString(
654             CurrentArg, SemaRef, getAllocator(), CCTUInfo,
655             includeBriefComments())) {
656       OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
657     }
658   }
659 }
660 
661 /// Retrieve the effective availability of the given declaration.
662 static AvailabilityResult getDeclAvailability(const Decl *D) {
663   AvailabilityResult AR = D->getAvailability();
664   if (isa<EnumConstantDecl>(D))
665     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
666   return AR;
667 }
668 
669 void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
670   switch (Kind) {
671   case RK_Pattern:
672     if (!Declaration) {
673       // Do nothing: Patterns can come with cursor kinds!
674       break;
675     }
676     LLVM_FALLTHROUGH;
677 
678   case RK_Declaration: {
679     // Set the availability based on attributes.
680     switch (getDeclAvailability(Declaration)) {
681     case AR_Available:
682     case AR_NotYetIntroduced:
683       Availability = CXAvailability_Available;
684       break;
685 
686     case AR_Deprecated:
687       Availability = CXAvailability_Deprecated;
688       break;
689 
690     case AR_Unavailable:
691       Availability = CXAvailability_NotAvailable;
692       break;
693     }
694 
695     if (const auto *Function = dyn_cast<FunctionDecl>(Declaration))
696       if (Function->isDeleted())
697         Availability = CXAvailability_NotAvailable;
698 
699     CursorKind = getCursorKindForDecl(Declaration);
700     if (CursorKind == CXCursor_UnexposedDecl) {
701       // FIXME: Forward declarations of Objective-C classes and protocols
702       // are not directly exposed, but we want code completion to treat them
703       // like a definition.
704       if (isa<ObjCInterfaceDecl>(Declaration))
705         CursorKind = CXCursor_ObjCInterfaceDecl;
706       else if (isa<ObjCProtocolDecl>(Declaration))
707         CursorKind = CXCursor_ObjCProtocolDecl;
708       else
709         CursorKind = CXCursor_NotImplemented;
710     }
711     break;
712   }
713 
714   case RK_Macro:
715   case RK_Keyword:
716     llvm_unreachable("Macro and keyword kinds are handled by the constructors");
717   }
718 
719   if (!Accessible)
720     Availability = CXAvailability_NotAccessible;
721 }
722 
723 /// Retrieve the name that should be used to order a result.
724 ///
725 /// If the name needs to be constructed as a string, that string will be
726 /// saved into Saved and the returned StringRef will refer to it.
727 StringRef CodeCompletionResult::getOrderedName(std::string &Saved) const {
728   switch (Kind) {
729   case RK_Keyword:
730     return Keyword;
731   case RK_Pattern:
732     return Pattern->getTypedText();
733   case RK_Macro:
734     return Macro->getName();
735   case RK_Declaration:
736     // Handle declarations below.
737     break;
738   }
739 
740   DeclarationName Name = Declaration->getDeclName();
741 
742   // If the name is a simple identifier (by far the common case), or a
743   // zero-argument selector, just return a reference to that identifier.
744   if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
745     return Id->getName();
746   if (Name.isObjCZeroArgSelector())
747     if (IdentifierInfo *Id = 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   return XStr.compare(YStr) < 0;
765 }
766