xref: /llvm-project/clang/lib/Sema/CodeCompleteConsumer.cpp (revision cd45e8c7bc16dec2eeec9cc71eb3ba87d1bd6bab) 
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/StringExtras.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   case CCC_Attribute:
86     return false;
87   }
88 
89   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
90 }
91 
92 StringRef clang::getCompletionKindString(CodeCompletionContext::Kind Kind) {
93   using CCKind = CodeCompletionContext::Kind;
94   switch (Kind) {
95   case CCKind::CCC_Other:
96     return "Other";
97   case CCKind::CCC_OtherWithMacros:
98     return "OtherWithMacros";
99   case CCKind::CCC_TopLevel:
100     return "TopLevel";
101   case CCKind::CCC_ObjCInterface:
102     return "ObjCInterface";
103   case CCKind::CCC_ObjCImplementation:
104     return "ObjCImplementation";
105   case CCKind::CCC_ObjCIvarList:
106     return "ObjCIvarList";
107   case CCKind::CCC_ClassStructUnion:
108     return "ClassStructUnion";
109   case CCKind::CCC_Statement:
110     return "Statement";
111   case CCKind::CCC_Expression:
112     return "Expression";
113   case CCKind::CCC_ObjCMessageReceiver:
114     return "ObjCMessageReceiver";
115   case CCKind::CCC_DotMemberAccess:
116     return "DotMemberAccess";
117   case CCKind::CCC_ArrowMemberAccess:
118     return "ArrowMemberAccess";
119   case CCKind::CCC_ObjCPropertyAccess:
120     return "ObjCPropertyAccess";
121   case CCKind::CCC_EnumTag:
122     return "EnumTag";
123   case CCKind::CCC_UnionTag:
124     return "UnionTag";
125   case CCKind::CCC_ClassOrStructTag:
126     return "ClassOrStructTag";
127   case CCKind::CCC_ObjCProtocolName:
128     return "ObjCProtocolName";
129   case CCKind::CCC_Namespace:
130     return "Namespace";
131   case CCKind::CCC_Type:
132     return "Type";
133   case CCKind::CCC_NewName:
134     return "NewName";
135   case CCKind::CCC_Symbol:
136     return "Symbol";
137   case CCKind::CCC_SymbolOrNewName:
138     return "SymbolOrNewName";
139   case CCKind::CCC_MacroName:
140     return "MacroName";
141   case CCKind::CCC_MacroNameUse:
142     return "MacroNameUse";
143   case CCKind::CCC_PreprocessorExpression:
144     return "PreprocessorExpression";
145   case CCKind::CCC_PreprocessorDirective:
146     return "PreprocessorDirective";
147   case CCKind::CCC_NaturalLanguage:
148     return "NaturalLanguage";
149   case CCKind::CCC_SelectorName:
150     return "SelectorName";
151   case CCKind::CCC_TypeQualifiers:
152     return "TypeQualifiers";
153   case CCKind::CCC_ParenthesizedExpression:
154     return "ParenthesizedExpression";
155   case CCKind::CCC_ObjCInstanceMessage:
156     return "ObjCInstanceMessage";
157   case CCKind::CCC_ObjCClassMessage:
158     return "ObjCClassMessage";
159   case CCKind::CCC_ObjCInterfaceName:
160     return "ObjCInterfaceName";
161   case CCKind::CCC_ObjCCategoryName:
162     return "ObjCCategoryName";
163   case CCKind::CCC_IncludedFile:
164     return "IncludedFile";
165   case CCKind::CCC_Attribute:
166     return "Attribute";
167   case CCKind::CCC_Recovery:
168     return "Recovery";
169   }
170   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
171 }
172 
173 //===----------------------------------------------------------------------===//
174 // Code completion string implementation
175 //===----------------------------------------------------------------------===//
176 
177 CodeCompletionString::Chunk::Chunk(ChunkKind Kind, const char *Text)
178     : Kind(Kind), Text("") {
179   switch (Kind) {
180   case CK_TypedText:
181   case CK_Text:
182   case CK_Placeholder:
183   case CK_Informative:
184   case CK_ResultType:
185   case CK_CurrentParameter:
186     this->Text = Text;
187     break;
188 
189   case CK_Optional:
190     llvm_unreachable("Optional strings cannot be created from text");
191 
192   case CK_LeftParen:
193     this->Text = "(";
194     break;
195 
196   case CK_RightParen:
197     this->Text = ")";
198     break;
199 
200   case CK_LeftBracket:
201     this->Text = "[";
202     break;
203 
204   case CK_RightBracket:
205     this->Text = "]";
206     break;
207 
208   case CK_LeftBrace:
209     this->Text = "{";
210     break;
211 
212   case CK_RightBrace:
213     this->Text = "}";
214     break;
215 
216   case CK_LeftAngle:
217     this->Text = "<";
218     break;
219 
220   case CK_RightAngle:
221     this->Text = ">";
222     break;
223 
224   case CK_Comma:
225     this->Text = ", ";
226     break;
227 
228   case CK_Colon:
229     this->Text = ":";
230     break;
231 
232   case CK_SemiColon:
233     this->Text = ";";
234     break;
235 
236   case CK_Equal:
237     this->Text = " = ";
238     break;
239 
240   case CK_HorizontalSpace:
241     this->Text = " ";
242     break;
243 
244   case CK_VerticalSpace:
245     this->Text = "\n";
246     break;
247   }
248 }
249 
250 CodeCompletionString::Chunk
251 CodeCompletionString::Chunk::CreateText(const char *Text) {
252   return Chunk(CK_Text, Text);
253 }
254 
255 CodeCompletionString::Chunk
256 CodeCompletionString::Chunk::CreateOptional(CodeCompletionString *Optional) {
257   Chunk Result;
258   Result.Kind = CK_Optional;
259   Result.Optional = Optional;
260   return Result;
261 }
262 
263 CodeCompletionString::Chunk
264 CodeCompletionString::Chunk::CreatePlaceholder(const char *Placeholder) {
265   return Chunk(CK_Placeholder, Placeholder);
266 }
267 
268 CodeCompletionString::Chunk
269 CodeCompletionString::Chunk::CreateInformative(const char *Informative) {
270   return Chunk(CK_Informative, Informative);
271 }
272 
273 CodeCompletionString::Chunk
274 CodeCompletionString::Chunk::CreateResultType(const char *ResultType) {
275   return Chunk(CK_ResultType, ResultType);
276 }
277 
278 CodeCompletionString::Chunk CodeCompletionString::Chunk::CreateCurrentParameter(
279     const char *CurrentParameter) {
280   return Chunk(CK_CurrentParameter, CurrentParameter);
281 }
282 
283 CodeCompletionString::CodeCompletionString(
284     const Chunk *Chunks, unsigned NumChunks, unsigned Priority,
285     CXAvailabilityKind Availability, const char **Annotations,
286     unsigned NumAnnotations, StringRef ParentName, const char *BriefComment)
287     : NumChunks(NumChunks), NumAnnotations(NumAnnotations), Priority(Priority),
288       Availability(Availability), ParentName(ParentName),
289       BriefComment(BriefComment) {
290   assert(NumChunks <= 0xffff);
291   assert(NumAnnotations <= 0xffff);
292 
293   Chunk *StoredChunks = reinterpret_cast<Chunk *>(this + 1);
294   for (unsigned I = 0; I != NumChunks; ++I)
295     StoredChunks[I] = Chunks[I];
296 
297   const char **StoredAnnotations =
298       reinterpret_cast<const char **>(StoredChunks + NumChunks);
299   for (unsigned I = 0; I != NumAnnotations; ++I)
300     StoredAnnotations[I] = Annotations[I];
301 }
302 
303 unsigned CodeCompletionString::getAnnotationCount() const {
304   return NumAnnotations;
305 }
306 
307 const char *CodeCompletionString::getAnnotation(unsigned AnnotationNr) const {
308   if (AnnotationNr < NumAnnotations)
309     return reinterpret_cast<const char *const *>(end())[AnnotationNr];
310   else
311     return nullptr;
312 }
313 
314 std::string CodeCompletionString::getAsString() const {
315   std::string Result;
316   llvm::raw_string_ostream OS(Result);
317 
318   for (const Chunk &C : *this) {
319     switch (C.Kind) {
320     case CK_Optional:
321       OS << "{#" << C.Optional->getAsString() << "#}";
322       break;
323     case CK_Placeholder:
324       OS << "<#" << C.Text << "#>";
325       break;
326     case CK_Informative:
327     case CK_ResultType:
328       OS << "[#" << C.Text << "#]";
329       break;
330     case CK_CurrentParameter:
331       OS << "<#" << C.Text << "#>";
332       break;
333     default:
334       OS << C.Text;
335       break;
336     }
337   }
338   return Result;
339 }
340 
341 const char *CodeCompletionString::getTypedText() const {
342   for (const Chunk &C : *this)
343     if (C.Kind == CK_TypedText)
344       return C.Text;
345 
346   return nullptr;
347 }
348 
349 const char *CodeCompletionAllocator::CopyString(const Twine &String) {
350   SmallString<128> Data;
351   StringRef Ref = String.toStringRef(Data);
352   // FIXME: It would be more efficient to teach Twine to tell us its size and
353   // then add a routine there to fill in an allocated char* with the contents
354   // of the string.
355   char *Mem = (char *)Allocate(Ref.size() + 1, 1);
356   std::copy(Ref.begin(), Ref.end(), Mem);
357   Mem[Ref.size()] = 0;
358   return Mem;
359 }
360 
361 StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
362   if (!isa<NamedDecl>(DC))
363     return {};
364 
365   // Check whether we've already cached the parent name.
366   StringRef &CachedParentName = ParentNames[DC];
367   if (!CachedParentName.empty())
368     return CachedParentName;
369 
370   // If we already processed this DeclContext and assigned empty to it, the
371   // data pointer will be non-null.
372   if (CachedParentName.data() != nullptr)
373     return {};
374 
375   // Find the interesting names.
376   SmallVector<const DeclContext *, 2> Contexts;
377   while (DC && !DC->isFunctionOrMethod()) {
378     if (const auto *ND = dyn_cast<NamedDecl>(DC)) {
379       if (ND->getIdentifier())
380         Contexts.push_back(DC);
381     }
382 
383     DC = DC->getParent();
384   }
385 
386   {
387     SmallString<128> S;
388     llvm::raw_svector_ostream OS(S);
389     bool First = true;
390     for (const DeclContext *CurDC : llvm::reverse(Contexts)) {
391       if (First)
392         First = false;
393       else {
394         OS << "::";
395       }
396 
397       if (const auto *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
398         CurDC = CatImpl->getCategoryDecl();
399 
400       if (const auto *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
401         const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
402         if (!Interface) {
403           // Assign an empty StringRef but with non-null data to distinguish
404           // between empty because we didn't process the DeclContext yet.
405           CachedParentName = StringRef((const char *)(uintptr_t)~0U, 0);
406           return {};
407         }
408 
409         OS << Interface->getName() << '(' << Cat->getName() << ')';
410       } else {
411         OS << cast<NamedDecl>(CurDC)->getName();
412       }
413     }
414 
415     CachedParentName = AllocatorRef->CopyString(OS.str());
416   }
417 
418   return CachedParentName;
419 }
420 
421 CodeCompletionString *CodeCompletionBuilder::TakeString() {
422   void *Mem = getAllocator().Allocate(
423       sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size() +
424           sizeof(const char *) * Annotations.size(),
425       alignof(CodeCompletionString));
426   CodeCompletionString *Result = new (Mem) CodeCompletionString(
427       Chunks.data(), Chunks.size(), Priority, Availability, Annotations.data(),
428       Annotations.size(), ParentName, BriefComment);
429   Chunks.clear();
430   return Result;
431 }
432 
433 void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
434   Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
435 }
436 
437 void CodeCompletionBuilder::AddTextChunk(const char *Text) {
438   Chunks.push_back(Chunk::CreateText(Text));
439 }
440 
441 void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
442   Chunks.push_back(Chunk::CreateOptional(Optional));
443 }
444 
445 void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
446   Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
447 }
448 
449 void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
450   Chunks.push_back(Chunk::CreateInformative(Text));
451 }
452 
453 void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
454   Chunks.push_back(Chunk::CreateResultType(ResultType));
455 }
456 
457 void CodeCompletionBuilder::AddCurrentParameterChunk(
458     const char *CurrentParameter) {
459   Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
460 }
461 
462 void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
463                                      const char *Text) {
464   Chunks.push_back(Chunk(CK, Text));
465 }
466 
467 void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
468   if (DC->isTranslationUnit())
469     return;
470 
471   if (DC->isFunctionOrMethod())
472     return;
473 
474   if (!isa<NamedDecl>(DC))
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 *CodeCompleteConsumer::OverloadCandidate::getFunction() const {
488   if (getKind() == CK_Function)
489     return Function;
490   else if (getKind() == CK_FunctionTemplate)
491     return FunctionTemplate->getTemplatedDecl();
492   else
493     return nullptr;
494 }
495 
496 const FunctionType *
497 CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
498   switch (Kind) {
499   case CK_Function:
500     return Function->getType()->getAs<FunctionType>();
501 
502   case CK_FunctionTemplate:
503     return FunctionTemplate->getTemplatedDecl()
504         ->getType()
505         ->getAs<FunctionType>();
506 
507   case CK_FunctionType:
508     return Type;
509 
510   case CK_Template:
511     return nullptr;
512   }
513 
514   llvm_unreachable("Invalid CandidateKind!");
515 }
516 
517 unsigned CodeCompleteConsumer::OverloadCandidate::getNumParams() const {
518   if (Kind == CK_Template)
519     return Template->getTemplateParameters()->size();
520   if (const auto *FPT = dyn_cast_or_null<FunctionProtoType>(getFunctionType()))
521     return FPT->getNumParams();
522   return 0;
523 }
524 
525 //===----------------------------------------------------------------------===//
526 // Code completion consumer implementation
527 //===----------------------------------------------------------------------===//
528 
529 CodeCompleteConsumer::~CodeCompleteConsumer() = default;
530 
531 bool PrintingCodeCompleteConsumer::isResultFilteredOut(
532     StringRef Filter, CodeCompletionResult Result) {
533   switch (Result.Kind) {
534   case CodeCompletionResult::RK_Declaration:
535     return !(Result.Declaration->getIdentifier() &&
536              Result.Declaration->getIdentifier()->getName().startswith(Filter));
537   case CodeCompletionResult::RK_Keyword:
538     return !StringRef(Result.Keyword).startswith(Filter);
539   case CodeCompletionResult::RK_Macro:
540     return !Result.Macro->getName().startswith(Filter);
541   case CodeCompletionResult::RK_Pattern:
542     return !(Result.Pattern->getTypedText() &&
543              StringRef(Result.Pattern->getTypedText()).startswith(Filter));
544   }
545   llvm_unreachable("Unknown code completion result Kind.");
546 }
547 
548 void PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(
549     Sema &SemaRef, CodeCompletionContext Context, CodeCompletionResult *Results,
550     unsigned NumResults) {
551   std::stable_sort(Results, Results + NumResults);
552 
553   if (!Context.getPreferredType().isNull())
554     OS << "PREFERRED-TYPE: " << Context.getPreferredType().getAsString()
555        << "\n";
556 
557   StringRef Filter = SemaRef.getPreprocessor().getCodeCompletionFilter();
558   // Print the completions.
559   for (unsigned I = 0; I != NumResults; ++I) {
560     if (!Filter.empty() && isResultFilteredOut(Filter, Results[I]))
561       continue;
562     OS << "COMPLETION: ";
563     switch (Results[I].Kind) {
564     case CodeCompletionResult::RK_Declaration:
565       OS << *Results[I].Declaration;
566       {
567         std::vector<std::string> Tags;
568         if (Results[I].Hidden)
569           Tags.push_back("Hidden");
570         if (Results[I].InBaseClass)
571           Tags.push_back("InBase");
572         if (Results[I].Availability ==
573             CXAvailabilityKind::CXAvailability_NotAccessible)
574           Tags.push_back("Inaccessible");
575         if (!Tags.empty())
576           OS << " (" << llvm::join(Tags, ",") << ")";
577       }
578       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
579               SemaRef, Context, getAllocator(), CCTUInfo,
580               includeBriefComments())) {
581         OS << " : " << CCS->getAsString();
582         if (const char *BriefComment = CCS->getBriefComment())
583           OS << " : " << BriefComment;
584       }
585       break;
586 
587     case CodeCompletionResult::RK_Keyword:
588       OS << Results[I].Keyword;
589       break;
590 
591     case CodeCompletionResult::RK_Macro:
592       OS << Results[I].Macro->getName();
593       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
594               SemaRef, Context, getAllocator(), CCTUInfo,
595               includeBriefComments())) {
596         OS << " : " << CCS->getAsString();
597       }
598       break;
599 
600     case CodeCompletionResult::RK_Pattern:
601       OS << "Pattern : " << Results[I].Pattern->getAsString();
602       break;
603     }
604     for (const FixItHint &FixIt : Results[I].FixIts) {
605       const SourceLocation BLoc = FixIt.RemoveRange.getBegin();
606       const SourceLocation ELoc = FixIt.RemoveRange.getEnd();
607 
608       SourceManager &SM = SemaRef.SourceMgr;
609       std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(BLoc);
610       std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(ELoc);
611       // Adjust for token ranges.
612       if (FixIt.RemoveRange.isTokenRange())
613         EInfo.second += Lexer::MeasureTokenLength(ELoc, SM, SemaRef.LangOpts);
614 
615       OS << " (requires fix-it:"
616          << " {" << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
617          << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
618          << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
619          << SM.getColumnNumber(EInfo.first, EInfo.second) << "}"
620          << " to \"" << FixIt.CodeToInsert << "\")";
621     }
622     OS << '\n';
623   }
624 }
625 
626 // This function is used solely to preserve the former presentation of overloads
627 // by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
628 // needs to be improved for printing the newer and more detailed overload
629 // chunks.
630 static std::string getOverloadAsString(const CodeCompletionString &CCS) {
631   std::string Result;
632   llvm::raw_string_ostream OS(Result);
633 
634   for (auto &C : CCS) {
635     switch (C.Kind) {
636     case CodeCompletionString::CK_Informative:
637     case CodeCompletionString::CK_ResultType:
638       OS << "[#" << C.Text << "#]";
639       break;
640 
641     case CodeCompletionString::CK_CurrentParameter:
642       OS << "<#" << C.Text << "#>";
643       break;
644 
645     // FIXME: We can also print optional parameters of an overload.
646     case CodeCompletionString::CK_Optional:
647       break;
648 
649     default:
650       OS << C.Text;
651       break;
652     }
653   }
654   return Result;
655 }
656 
657 void PrintingCodeCompleteConsumer::ProcessOverloadCandidates(
658     Sema &SemaRef, unsigned CurrentArg, OverloadCandidate *Candidates,
659     unsigned NumCandidates, SourceLocation OpenParLoc) {
660   OS << "OPENING_PAREN_LOC: ";
661   OpenParLoc.print(OS, SemaRef.getSourceManager());
662   OS << "\n";
663 
664   for (unsigned I = 0; I != NumCandidates; ++I) {
665     if (CodeCompletionString *CCS = Candidates[I].CreateSignatureString(
666             CurrentArg, SemaRef, getAllocator(), CCTUInfo,
667             includeBriefComments())) {
668       OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
669     }
670   }
671 }
672 
673 /// Retrieve the effective availability of the given declaration.
674 static AvailabilityResult getDeclAvailability(const Decl *D) {
675   AvailabilityResult AR = D->getAvailability();
676   if (isa<EnumConstantDecl>(D))
677     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
678   return AR;
679 }
680 
681 void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
682   switch (Kind) {
683   case RK_Pattern:
684     if (!Declaration) {
685       // Do nothing: Patterns can come with cursor kinds!
686       break;
687     }
688     LLVM_FALLTHROUGH;
689 
690   case RK_Declaration: {
691     // Set the availability based on attributes.
692     switch (getDeclAvailability(Declaration)) {
693     case AR_Available:
694     case AR_NotYetIntroduced:
695       Availability = CXAvailability_Available;
696       break;
697 
698     case AR_Deprecated:
699       Availability = CXAvailability_Deprecated;
700       break;
701 
702     case AR_Unavailable:
703       Availability = CXAvailability_NotAvailable;
704       break;
705     }
706 
707     if (const auto *Function = dyn_cast<FunctionDecl>(Declaration))
708       if (Function->isDeleted())
709         Availability = CXAvailability_NotAvailable;
710 
711     CursorKind = getCursorKindForDecl(Declaration);
712     if (CursorKind == CXCursor_UnexposedDecl) {
713       // FIXME: Forward declarations of Objective-C classes and protocols
714       // are not directly exposed, but we want code completion to treat them
715       // like a definition.
716       if (isa<ObjCInterfaceDecl>(Declaration))
717         CursorKind = CXCursor_ObjCInterfaceDecl;
718       else if (isa<ObjCProtocolDecl>(Declaration))
719         CursorKind = CXCursor_ObjCProtocolDecl;
720       else
721         CursorKind = CXCursor_NotImplemented;
722     }
723     break;
724   }
725 
726   case RK_Macro:
727   case RK_Keyword:
728     llvm_unreachable("Macro and keyword kinds are handled by the constructors");
729   }
730 
731   if (!Accessible)
732     Availability = CXAvailability_NotAccessible;
733 }
734 
735 /// Retrieve the name that should be used to order a result.
736 ///
737 /// If the name needs to be constructed as a string, that string will be
738 /// saved into Saved and the returned StringRef will refer to it.
739 StringRef CodeCompletionResult::getOrderedName(std::string &Saved) const {
740   switch (Kind) {
741   case RK_Keyword:
742     return Keyword;
743   case RK_Pattern:
744     return Pattern->getTypedText();
745   case RK_Macro:
746     return Macro->getName();
747   case RK_Declaration:
748     // Handle declarations below.
749     break;
750   }
751 
752   DeclarationName Name = Declaration->getDeclName();
753 
754   // If the name is a simple identifier (by far the common case), or a
755   // zero-argument selector, just return a reference to that identifier.
756   if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
757     return Id->getName();
758   if (Name.isObjCZeroArgSelector())
759     if (IdentifierInfo *Id = Name.getObjCSelector().getIdentifierInfoForSlot(0))
760       return Id->getName();
761 
762   Saved = Name.getAsString();
763   return Saved;
764 }
765 
766 bool clang::operator<(const CodeCompletionResult &X,
767                       const CodeCompletionResult &Y) {
768   std::string XSaved, YSaved;
769   StringRef XStr = X.getOrderedName(XSaved);
770   StringRef YStr = Y.getOrderedName(YSaved);
771   int cmp = XStr.compare_insensitive(YStr);
772   if (cmp)
773     return cmp < 0;
774 
775   // If case-insensitive comparison fails, try case-sensitive comparison.
776   return XStr.compare(YStr) < 0;
777 }
778