xref: /llvm-project/clang/lib/Sema/CodeCompleteConsumer.cpp (revision 46d750be2e19220c318bc907dfaf6c61d3a0de92) 
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/StringExtras.h"
25 #include "llvm/ADT/StringRef.h"
26 #include "llvm/ADT/Twine.h"
27 #include "llvm/Support/Compiler.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/raw_ostream.h"
30 #include <algorithm>
31 #include <cassert>
32 #include <cstdint>
33 #include <string>
34 
35 using namespace clang;
36 
37 //===----------------------------------------------------------------------===//
38 // Code completion context implementation
39 //===----------------------------------------------------------------------===//
40 
41 bool CodeCompletionContext::wantConstructorResults() const {
42   switch (CCKind) {
43   case CCC_Recovery:
44   case CCC_Statement:
45   case CCC_Expression:
46   case CCC_ObjCMessageReceiver:
47   case CCC_ParenthesizedExpression:
48   case CCC_Symbol:
49   case CCC_SymbolOrNewName:
50   case CCC_TopLevelOrExpression:
51     return true;
52 
53   case CCC_TopLevel:
54   case CCC_ObjCInterface:
55   case CCC_ObjCImplementation:
56   case CCC_ObjCIvarList:
57   case CCC_ClassStructUnion:
58   case CCC_DotMemberAccess:
59   case CCC_ArrowMemberAccess:
60   case CCC_ObjCPropertyAccess:
61   case CCC_EnumTag:
62   case CCC_UnionTag:
63   case CCC_ClassOrStructTag:
64   case CCC_ObjCProtocolName:
65   case CCC_Namespace:
66   case CCC_Type:
67   case CCC_NewName:
68   case CCC_MacroName:
69   case CCC_MacroNameUse:
70   case CCC_PreprocessorExpression:
71   case CCC_PreprocessorDirective:
72   case CCC_NaturalLanguage:
73   case CCC_SelectorName:
74   case CCC_TypeQualifiers:
75   case CCC_Other:
76   case CCC_OtherWithMacros:
77   case CCC_ObjCInstanceMessage:
78   case CCC_ObjCClassMessage:
79   case CCC_ObjCInterfaceName:
80   case CCC_ObjCCategoryName:
81   case CCC_IncludedFile:
82   case CCC_Attribute:
83   case CCC_ObjCClassForwardDecl:
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_Attribute:
164     return "Attribute";
165   case CCKind::CCC_Recovery:
166     return "Recovery";
167   case CCKind::CCC_ObjCClassForwardDecl:
168     return "ObjCClassForwardDecl";
169   case CCKind::CCC_TopLevelOrExpression:
170     return "ReplTopLevel";
171   }
172   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
173 }
174 
175 //===----------------------------------------------------------------------===//
176 // Code completion string implementation
177 //===----------------------------------------------------------------------===//
178 
179 CodeCompletionString::Chunk::Chunk(ChunkKind Kind, const char *Text)
180     : Kind(Kind), Text("") {
181   switch (Kind) {
182   case CK_TypedText:
183   case CK_Text:
184   case CK_Placeholder:
185   case CK_Informative:
186   case CK_ResultType:
187   case CK_CurrentParameter:
188     this->Text = Text;
189     break;
190 
191   case CK_Optional:
192     llvm_unreachable("Optional strings cannot be created from text");
193 
194   case CK_LeftParen:
195     this->Text = "(";
196     break;
197 
198   case CK_RightParen:
199     this->Text = ")";
200     break;
201 
202   case CK_LeftBracket:
203     this->Text = "[";
204     break;
205 
206   case CK_RightBracket:
207     this->Text = "]";
208     break;
209 
210   case CK_LeftBrace:
211     this->Text = "{";
212     break;
213 
214   case CK_RightBrace:
215     this->Text = "}";
216     break;
217 
218   case CK_LeftAngle:
219     this->Text = "<";
220     break;
221 
222   case CK_RightAngle:
223     this->Text = ">";
224     break;
225 
226   case CK_Comma:
227     this->Text = ", ";
228     break;
229 
230   case CK_Colon:
231     this->Text = ":";
232     break;
233 
234   case CK_SemiColon:
235     this->Text = ";";
236     break;
237 
238   case CK_Equal:
239     this->Text = " = ";
240     break;
241 
242   case CK_HorizontalSpace:
243     this->Text = " ";
244     break;
245 
246   case CK_VerticalSpace:
247     this->Text = "\n";
248     break;
249   }
250 }
251 
252 CodeCompletionString::Chunk
253 CodeCompletionString::Chunk::CreateText(const char *Text) {
254   return Chunk(CK_Text, Text);
255 }
256 
257 CodeCompletionString::Chunk
258 CodeCompletionString::Chunk::CreateOptional(CodeCompletionString *Optional) {
259   Chunk Result;
260   Result.Kind = CK_Optional;
261   Result.Optional = Optional;
262   return Result;
263 }
264 
265 CodeCompletionString::Chunk
266 CodeCompletionString::Chunk::CreatePlaceholder(const char *Placeholder) {
267   return Chunk(CK_Placeholder, Placeholder);
268 }
269 
270 CodeCompletionString::Chunk
271 CodeCompletionString::Chunk::CreateInformative(const char *Informative) {
272   return Chunk(CK_Informative, Informative);
273 }
274 
275 CodeCompletionString::Chunk
276 CodeCompletionString::Chunk::CreateResultType(const char *ResultType) {
277   return Chunk(CK_ResultType, ResultType);
278 }
279 
280 CodeCompletionString::Chunk CodeCompletionString::Chunk::CreateCurrentParameter(
281     const char *CurrentParameter) {
282   return Chunk(CK_CurrentParameter, CurrentParameter);
283 }
284 
285 CodeCompletionString::CodeCompletionString(
286     const Chunk *Chunks, unsigned NumChunks, unsigned Priority,
287     CXAvailabilityKind Availability, const char **Annotations,
288     unsigned NumAnnotations, StringRef ParentName, const char *BriefComment)
289     : NumChunks(NumChunks), NumAnnotations(NumAnnotations), Priority(Priority),
290       Availability(Availability), ParentName(ParentName),
291       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 =
300       reinterpret_cast<const char **>(StoredChunks + NumChunks);
301   for (unsigned I = 0; I != NumAnnotations; ++I)
302     StoredAnnotations[I] = Annotations[I];
303 }
304 
305 unsigned CodeCompletionString::getAnnotationCount() const {
306   return NumAnnotations;
307 }
308 
309 const char *CodeCompletionString::getAnnotation(unsigned AnnotationNr) const {
310   if (AnnotationNr < NumAnnotations)
311     return reinterpret_cast<const char *const *>(end())[AnnotationNr];
312   else
313     return nullptr;
314 }
315 
316 std::string CodeCompletionString::getAsString() const {
317   std::string Result;
318   llvm::raw_string_ostream OS(Result);
319 
320   for (const Chunk &C : *this) {
321     switch (C.Kind) {
322     case CK_Optional:
323       OS << "{#" << C.Optional->getAsString() << "#}";
324       break;
325     case CK_Placeholder:
326       OS << "<#" << C.Text << "#>";
327       break;
328     case CK_Informative:
329     case CK_ResultType:
330       OS << "[#" << C.Text << "#]";
331       break;
332     case CK_CurrentParameter:
333       OS << "<#" << C.Text << "#>";
334       break;
335     default:
336       OS << C.Text;
337       break;
338     }
339   }
340   return Result;
341 }
342 
343 const char *CodeCompletionString::getTypedText() const {
344   for (const Chunk &C : *this)
345     if (C.Kind == CK_TypedText)
346       return C.Text;
347 
348   return nullptr;
349 }
350 
351 std::string CodeCompletionString::getAllTypedText() const {
352   std::string Res;
353   for (const Chunk &C : *this)
354     if (C.Kind == CK_TypedText)
355       Res += C.Text;
356 
357   return Res;
358 }
359 
360 const char *CodeCompletionAllocator::CopyString(const Twine &String) {
361   SmallString<128> Data;
362   StringRef Ref = String.toStringRef(Data);
363   // FIXME: It would be more efficient to teach Twine to tell us its size and
364   // then add a routine there to fill in an allocated char* with the contents
365   // of the string.
366   char *Mem = (char *)Allocate(Ref.size() + 1, 1);
367   std::copy(Ref.begin(), Ref.end(), Mem);
368   Mem[Ref.size()] = 0;
369   return Mem;
370 }
371 
372 StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
373   if (!isa<NamedDecl>(DC))
374     return {};
375 
376   // Check whether we've already cached the parent name.
377   StringRef &CachedParentName = ParentNames[DC];
378   if (!CachedParentName.empty())
379     return CachedParentName;
380 
381   // If we already processed this DeclContext and assigned empty to it, the
382   // data pointer will be non-null.
383   if (CachedParentName.data() != nullptr)
384     return {};
385 
386   // Find the interesting names.
387   SmallVector<const DeclContext *, 2> Contexts;
388   while (DC && !DC->isFunctionOrMethod()) {
389     if (const auto *ND = dyn_cast<NamedDecl>(DC)) {
390       if (ND->getIdentifier())
391         Contexts.push_back(DC);
392     }
393 
394     DC = DC->getParent();
395   }
396 
397   {
398     SmallString<128> S;
399     llvm::raw_svector_ostream OS(S);
400     bool First = true;
401     for (const DeclContext *CurDC : llvm::reverse(Contexts)) {
402       if (First)
403         First = false;
404       else {
405         OS << "::";
406       }
407 
408       if (const auto *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
409         CurDC = CatImpl->getCategoryDecl();
410 
411       if (const auto *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
412         const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
413         if (!Interface) {
414           // Assign an empty StringRef but with non-null data to distinguish
415           // between empty because we didn't process the DeclContext yet.
416           CachedParentName = StringRef((const char *)(uintptr_t)~0U, 0);
417           return {};
418         }
419 
420         OS << Interface->getName() << '(' << Cat->getName() << ')';
421       } else {
422         OS << cast<NamedDecl>(CurDC)->getName();
423       }
424     }
425 
426     CachedParentName = AllocatorRef->CopyString(OS.str());
427   }
428 
429   return CachedParentName;
430 }
431 
432 CodeCompletionString *CodeCompletionBuilder::TakeString() {
433   void *Mem = getAllocator().Allocate(
434       sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size() +
435           sizeof(const char *) * Annotations.size(),
436       alignof(CodeCompletionString));
437   CodeCompletionString *Result = new (Mem) CodeCompletionString(
438       Chunks.data(), Chunks.size(), Priority, Availability, Annotations.data(),
439       Annotations.size(), ParentName, BriefComment);
440   Chunks.clear();
441   return Result;
442 }
443 
444 void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
445   Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
446 }
447 
448 void CodeCompletionBuilder::AddTextChunk(const char *Text) {
449   Chunks.push_back(Chunk::CreateText(Text));
450 }
451 
452 void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
453   Chunks.push_back(Chunk::CreateOptional(Optional));
454 }
455 
456 void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
457   Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
458 }
459 
460 void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
461   Chunks.push_back(Chunk::CreateInformative(Text));
462 }
463 
464 void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
465   Chunks.push_back(Chunk::CreateResultType(ResultType));
466 }
467 
468 void CodeCompletionBuilder::AddCurrentParameterChunk(
469     const char *CurrentParameter) {
470   Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
471 }
472 
473 void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
474                                      const char *Text) {
475   Chunks.push_back(Chunk(CK, Text));
476 }
477 
478 void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
479   if (DC->isTranslationUnit())
480     return;
481 
482   if (DC->isFunctionOrMethod())
483     return;
484 
485   if (!isa<NamedDecl>(DC))
486     return;
487 
488   ParentName = getCodeCompletionTUInfo().getParentName(DC);
489 }
490 
491 void CodeCompletionBuilder::addBriefComment(StringRef Comment) {
492   BriefComment = Allocator.CopyString(Comment);
493 }
494 
495 //===----------------------------------------------------------------------===//
496 // Code completion overload candidate implementation
497 //===----------------------------------------------------------------------===//
498 FunctionDecl *CodeCompleteConsumer::OverloadCandidate::getFunction() const {
499   if (getKind() == CK_Function)
500     return Function;
501   else if (getKind() == CK_FunctionTemplate)
502     return FunctionTemplate->getTemplatedDecl();
503   else
504     return nullptr;
505 }
506 
507 const FunctionType *
508 CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
509   switch (Kind) {
510   case CK_Function:
511     return Function->getType()->getAs<FunctionType>();
512 
513   case CK_FunctionTemplate:
514     return FunctionTemplate->getTemplatedDecl()
515         ->getType()
516         ->getAs<FunctionType>();
517 
518   case CK_FunctionType:
519     return Type;
520   case CK_FunctionProtoTypeLoc:
521     return ProtoTypeLoc.getTypePtr();
522   case CK_Template:
523   case CK_Aggregate:
524     return nullptr;
525   }
526 
527   llvm_unreachable("Invalid CandidateKind!");
528 }
529 
530 const FunctionProtoTypeLoc
531 CodeCompleteConsumer::OverloadCandidate::getFunctionProtoTypeLoc() const {
532   if (Kind == CK_FunctionProtoTypeLoc)
533     return ProtoTypeLoc;
534   return FunctionProtoTypeLoc();
535 }
536 
537 unsigned CodeCompleteConsumer::OverloadCandidate::getNumParams() const {
538   if (Kind == CK_Template)
539     return Template->getTemplateParameters()->size();
540 
541   if (Kind == CK_Aggregate) {
542     unsigned Count =
543         std::distance(AggregateType->field_begin(), AggregateType->field_end());
544     if (const auto *CRD = dyn_cast<CXXRecordDecl>(AggregateType))
545       Count += CRD->getNumBases();
546     return Count;
547   }
548 
549   if (const auto *FT = getFunctionType())
550     if (const auto *FPT = dyn_cast<FunctionProtoType>(FT))
551       return FPT->getNumParams();
552 
553   return 0;
554 }
555 
556 QualType
557 CodeCompleteConsumer::OverloadCandidate::getParamType(unsigned N) const {
558   if (Kind == CK_Aggregate) {
559     if (const auto *CRD = dyn_cast<CXXRecordDecl>(AggregateType)) {
560       if (N < CRD->getNumBases())
561         return std::next(CRD->bases_begin(), N)->getType();
562       N -= CRD->getNumBases();
563     }
564     for (const auto *Field : AggregateType->fields())
565       if (N-- == 0)
566         return Field->getType();
567     return QualType();
568   }
569 
570   if (Kind == CK_Template) {
571     TemplateParameterList *TPL = getTemplate()->getTemplateParameters();
572     if (N < TPL->size())
573       if (const auto *D = dyn_cast<NonTypeTemplateParmDecl>(TPL->getParam(N)))
574         return D->getType();
575     return QualType();
576   }
577 
578   if (const auto *FT = getFunctionType())
579     if (const auto *FPT = dyn_cast<FunctionProtoType>(FT))
580       if (N < FPT->getNumParams())
581         return FPT->getParamType(N);
582   return QualType();
583 }
584 
585 const NamedDecl *
586 CodeCompleteConsumer::OverloadCandidate::getParamDecl(unsigned N) const {
587   if (Kind == CK_Aggregate) {
588     if (const auto *CRD = dyn_cast<CXXRecordDecl>(AggregateType)) {
589       if (N < CRD->getNumBases())
590         return std::next(CRD->bases_begin(), N)->getType()->getAsTagDecl();
591       N -= CRD->getNumBases();
592     }
593     for (const auto *Field : AggregateType->fields())
594       if (N-- == 0)
595         return Field;
596     return nullptr;
597   }
598 
599   if (Kind == CK_Template) {
600     TemplateParameterList *TPL = getTemplate()->getTemplateParameters();
601     if (N < TPL->size())
602       return TPL->getParam(N);
603     return nullptr;
604   }
605 
606   // Note that if we only have a FunctionProtoType, we don't have param decls.
607   if (const auto *FD = getFunction()) {
608     if (N < FD->param_size())
609       return FD->getParamDecl(N);
610   } else if (Kind == CK_FunctionProtoTypeLoc) {
611     if (N < ProtoTypeLoc.getNumParams()) {
612       return ProtoTypeLoc.getParam(N);
613     }
614   }
615 
616   return nullptr;
617 }
618 
619 //===----------------------------------------------------------------------===//
620 // Code completion consumer implementation
621 //===----------------------------------------------------------------------===//
622 
623 CodeCompleteConsumer::~CodeCompleteConsumer() = default;
624 
625 bool PrintingCodeCompleteConsumer::isResultFilteredOut(
626     StringRef Filter, CodeCompletionResult Result) {
627   switch (Result.Kind) {
628   case CodeCompletionResult::RK_Declaration:
629     return !(
630         Result.Declaration->getIdentifier() &&
631         Result.Declaration->getIdentifier()->getName().starts_with(Filter));
632   case CodeCompletionResult::RK_Keyword:
633     return !StringRef(Result.Keyword).starts_with(Filter);
634   case CodeCompletionResult::RK_Macro:
635     return !Result.Macro->getName().starts_with(Filter);
636   case CodeCompletionResult::RK_Pattern:
637     return !(Result.Pattern->getTypedText() &&
638              StringRef(Result.Pattern->getTypedText()).starts_with(Filter));
639   }
640   llvm_unreachable("Unknown code completion result Kind.");
641 }
642 
643 void PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(
644     Sema &SemaRef, CodeCompletionContext Context, CodeCompletionResult *Results,
645     unsigned NumResults) {
646   std::stable_sort(Results, Results + NumResults);
647 
648   if (!Context.getPreferredType().isNull())
649     OS << "PREFERRED-TYPE: " << Context.getPreferredType() << '\n';
650 
651   StringRef Filter = SemaRef.getPreprocessor().getCodeCompletionFilter();
652   // Print the completions.
653   for (unsigned I = 0; I != NumResults; ++I) {
654     if (!Filter.empty() && isResultFilteredOut(Filter, Results[I]))
655       continue;
656     OS << "COMPLETION: ";
657     switch (Results[I].Kind) {
658     case CodeCompletionResult::RK_Declaration:
659       OS << *Results[I].Declaration;
660       {
661         std::vector<std::string> Tags;
662         if (Results[I].Hidden)
663           Tags.push_back("Hidden");
664         if (Results[I].InBaseClass)
665           Tags.push_back("InBase");
666         if (Results[I].Availability ==
667             CXAvailabilityKind::CXAvailability_NotAccessible)
668           Tags.push_back("Inaccessible");
669         if (!Tags.empty())
670           OS << " (" << llvm::join(Tags, ",") << ")";
671       }
672       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
673               SemaRef, Context, getAllocator(), CCTUInfo,
674               includeBriefComments())) {
675         OS << " : " << CCS->getAsString();
676         if (const char *BriefComment = CCS->getBriefComment())
677           OS << " : " << BriefComment;
678       }
679       break;
680 
681     case CodeCompletionResult::RK_Keyword:
682       OS << Results[I].Keyword;
683       break;
684 
685     case CodeCompletionResult::RK_Macro:
686       OS << Results[I].Macro->getName();
687       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
688               SemaRef, Context, getAllocator(), CCTUInfo,
689               includeBriefComments())) {
690         OS << " : " << CCS->getAsString();
691       }
692       break;
693 
694     case CodeCompletionResult::RK_Pattern:
695       OS << "Pattern : " << Results[I].Pattern->getAsString();
696       break;
697     }
698     for (const FixItHint &FixIt : Results[I].FixIts) {
699       const SourceLocation BLoc = FixIt.RemoveRange.getBegin();
700       const SourceLocation ELoc = FixIt.RemoveRange.getEnd();
701 
702       SourceManager &SM = SemaRef.SourceMgr;
703       std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(BLoc);
704       std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(ELoc);
705       // Adjust for token ranges.
706       if (FixIt.RemoveRange.isTokenRange())
707         EInfo.second += Lexer::MeasureTokenLength(ELoc, SM, SemaRef.LangOpts);
708 
709       OS << " (requires fix-it:"
710          << " {" << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
711          << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
712          << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
713          << SM.getColumnNumber(EInfo.first, EInfo.second) << "}"
714          << " to \"" << FixIt.CodeToInsert << "\")";
715     }
716     OS << '\n';
717   }
718 }
719 
720 // This function is used solely to preserve the former presentation of overloads
721 // by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
722 // needs to be improved for printing the newer and more detailed overload
723 // chunks.
724 static std::string getOverloadAsString(const CodeCompletionString &CCS) {
725   std::string Result;
726   llvm::raw_string_ostream OS(Result);
727 
728   for (auto &C : CCS) {
729     switch (C.Kind) {
730     case CodeCompletionString::CK_Informative:
731     case CodeCompletionString::CK_ResultType:
732       OS << "[#" << C.Text << "#]";
733       break;
734 
735     case CodeCompletionString::CK_CurrentParameter:
736       OS << "<#" << C.Text << "#>";
737       break;
738 
739     // FIXME: We can also print optional parameters of an overload.
740     case CodeCompletionString::CK_Optional:
741       break;
742 
743     default:
744       OS << C.Text;
745       break;
746     }
747   }
748   return Result;
749 }
750 
751 void PrintingCodeCompleteConsumer::ProcessOverloadCandidates(
752     Sema &SemaRef, unsigned CurrentArg, OverloadCandidate *Candidates,
753     unsigned NumCandidates, SourceLocation OpenParLoc, bool Braced) {
754   OS << "OPENING_PAREN_LOC: ";
755   OpenParLoc.print(OS, SemaRef.getSourceManager());
756   OS << "\n";
757 
758   for (unsigned I = 0; I != NumCandidates; ++I) {
759     if (CodeCompletionString *CCS = Candidates[I].CreateSignatureString(
760             CurrentArg, SemaRef, getAllocator(), CCTUInfo,
761             includeBriefComments(), Braced)) {
762       OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
763     }
764   }
765 }
766 
767 /// Retrieve the effective availability of the given declaration.
768 static AvailabilityResult getDeclAvailability(const Decl *D) {
769   AvailabilityResult AR = D->getAvailability();
770   if (isa<EnumConstantDecl>(D))
771     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
772   return AR;
773 }
774 
775 void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
776   switch (Kind) {
777   case RK_Pattern:
778     if (!Declaration) {
779       // Do nothing: Patterns can come with cursor kinds!
780       break;
781     }
782     [[fallthrough]];
783 
784   case RK_Declaration: {
785     // Set the availability based on attributes.
786     switch (getDeclAvailability(Declaration)) {
787     case AR_Available:
788     case AR_NotYetIntroduced:
789       Availability = CXAvailability_Available;
790       break;
791 
792     case AR_Deprecated:
793       Availability = CXAvailability_Deprecated;
794       break;
795 
796     case AR_Unavailable:
797       Availability = CXAvailability_NotAvailable;
798       break;
799     }
800 
801     if (const auto *Function = dyn_cast<FunctionDecl>(Declaration))
802       if (Function->isDeleted())
803         Availability = CXAvailability_NotAvailable;
804 
805     CursorKind = getCursorKindForDecl(Declaration);
806     if (CursorKind == CXCursor_UnexposedDecl) {
807       // FIXME: Forward declarations of Objective-C classes and protocols
808       // are not directly exposed, but we want code completion to treat them
809       // like a definition.
810       if (isa<ObjCInterfaceDecl>(Declaration))
811         CursorKind = CXCursor_ObjCInterfaceDecl;
812       else if (isa<ObjCProtocolDecl>(Declaration))
813         CursorKind = CXCursor_ObjCProtocolDecl;
814       else
815         CursorKind = CXCursor_NotImplemented;
816     }
817     break;
818   }
819 
820   case RK_Macro:
821   case RK_Keyword:
822     llvm_unreachable("Macro and keyword kinds are handled by the constructors");
823   }
824 
825   if (!Accessible)
826     Availability = CXAvailability_NotAccessible;
827 }
828 
829 /// Retrieve the name that should be used to order a result.
830 ///
831 /// If the name needs to be constructed as a string, that string will be
832 /// saved into Saved and the returned StringRef will refer to it.
833 StringRef CodeCompletionResult::getOrderedName(std::string &Saved) const {
834   switch (Kind) {
835   case RK_Keyword:
836     return Keyword;
837   case RK_Pattern:
838     return Pattern->getTypedText();
839   case RK_Macro:
840     return Macro->getName();
841   case RK_Declaration:
842     // Handle declarations below.
843     break;
844   }
845 
846   DeclarationName Name = Declaration->getDeclName();
847 
848   // If the name is a simple identifier (by far the common case), or a
849   // zero-argument selector, just return a reference to that identifier.
850   if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
851     return Id->getName();
852   if (Name.isObjCZeroArgSelector())
853     if (const IdentifierInfo *Id =
854             Name.getObjCSelector().getIdentifierInfoForSlot(0))
855       return Id->getName();
856 
857   Saved = Name.getAsString();
858   return Saved;
859 }
860 
861 bool clang::operator<(const CodeCompletionResult &X,
862                       const CodeCompletionResult &Y) {
863   std::string XSaved, YSaved;
864   StringRef XStr = X.getOrderedName(XSaved);
865   StringRef YStr = Y.getOrderedName(YSaved);
866   int cmp = XStr.compare_insensitive(YStr);
867   if (cmp)
868     return cmp < 0;
869 
870   // If case-insensitive comparison fails, try case-sensitive comparison.
871   return XStr.compare(YStr) < 0;
872 }
873