xref: /freebsd/contrib/llvm-project/clang/lib/Sema/CodeCompleteConsumer.cpp (revision 7ef62cebc2f965b0f640263e179276928885e33d) 
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 std::string CodeCompletionString::getAllTypedText() const {
350   std::string Res;
351   for (const Chunk &C : *this)
352     if (C.Kind == CK_TypedText)
353       Res += C.Text;
354 
355   return Res;
356 }
357 
358 const char *CodeCompletionAllocator::CopyString(const Twine &String) {
359   SmallString<128> Data;
360   StringRef Ref = String.toStringRef(Data);
361   // FIXME: It would be more efficient to teach Twine to tell us its size and
362   // then add a routine there to fill in an allocated char* with the contents
363   // of the string.
364   char *Mem = (char *)Allocate(Ref.size() + 1, 1);
365   std::copy(Ref.begin(), Ref.end(), Mem);
366   Mem[Ref.size()] = 0;
367   return Mem;
368 }
369 
370 StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
371   if (!isa<NamedDecl>(DC))
372     return {};
373 
374   // Check whether we've already cached the parent name.
375   StringRef &CachedParentName = ParentNames[DC];
376   if (!CachedParentName.empty())
377     return CachedParentName;
378 
379   // If we already processed this DeclContext and assigned empty to it, the
380   // data pointer will be non-null.
381   if (CachedParentName.data() != nullptr)
382     return {};
383 
384   // Find the interesting names.
385   SmallVector<const DeclContext *, 2> Contexts;
386   while (DC && !DC->isFunctionOrMethod()) {
387     if (const auto *ND = dyn_cast<NamedDecl>(DC)) {
388       if (ND->getIdentifier())
389         Contexts.push_back(DC);
390     }
391 
392     DC = DC->getParent();
393   }
394 
395   {
396     SmallString<128> S;
397     llvm::raw_svector_ostream OS(S);
398     bool First = true;
399     for (const DeclContext *CurDC : llvm::reverse(Contexts)) {
400       if (First)
401         First = false;
402       else {
403         OS << "::";
404       }
405 
406       if (const auto *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
407         CurDC = CatImpl->getCategoryDecl();
408 
409       if (const auto *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
410         const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
411         if (!Interface) {
412           // Assign an empty StringRef but with non-null data to distinguish
413           // between empty because we didn't process the DeclContext yet.
414           CachedParentName = StringRef((const char *)(uintptr_t)~0U, 0);
415           return {};
416         }
417 
418         OS << Interface->getName() << '(' << Cat->getName() << ')';
419       } else {
420         OS << cast<NamedDecl>(CurDC)->getName();
421       }
422     }
423 
424     CachedParentName = AllocatorRef->CopyString(OS.str());
425   }
426 
427   return CachedParentName;
428 }
429 
430 CodeCompletionString *CodeCompletionBuilder::TakeString() {
431   void *Mem = getAllocator().Allocate(
432       sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size() +
433           sizeof(const char *) * Annotations.size(),
434       alignof(CodeCompletionString));
435   CodeCompletionString *Result = new (Mem) CodeCompletionString(
436       Chunks.data(), Chunks.size(), Priority, Availability, Annotations.data(),
437       Annotations.size(), ParentName, BriefComment);
438   Chunks.clear();
439   return Result;
440 }
441 
442 void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
443   Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
444 }
445 
446 void CodeCompletionBuilder::AddTextChunk(const char *Text) {
447   Chunks.push_back(Chunk::CreateText(Text));
448 }
449 
450 void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
451   Chunks.push_back(Chunk::CreateOptional(Optional));
452 }
453 
454 void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
455   Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
456 }
457 
458 void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
459   Chunks.push_back(Chunk::CreateInformative(Text));
460 }
461 
462 void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
463   Chunks.push_back(Chunk::CreateResultType(ResultType));
464 }
465 
466 void CodeCompletionBuilder::AddCurrentParameterChunk(
467     const char *CurrentParameter) {
468   Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
469 }
470 
471 void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
472                                      const char *Text) {
473   Chunks.push_back(Chunk(CK, Text));
474 }
475 
476 void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
477   if (DC->isTranslationUnit())
478     return;
479 
480   if (DC->isFunctionOrMethod())
481     return;
482 
483   if (!isa<NamedDecl>(DC))
484     return;
485 
486   ParentName = getCodeCompletionTUInfo().getParentName(DC);
487 }
488 
489 void CodeCompletionBuilder::addBriefComment(StringRef Comment) {
490   BriefComment = Allocator.CopyString(Comment);
491 }
492 
493 //===----------------------------------------------------------------------===//
494 // Code completion overload candidate implementation
495 //===----------------------------------------------------------------------===//
496 FunctionDecl *CodeCompleteConsumer::OverloadCandidate::getFunction() const {
497   if (getKind() == CK_Function)
498     return Function;
499   else if (getKind() == CK_FunctionTemplate)
500     return FunctionTemplate->getTemplatedDecl();
501   else
502     return nullptr;
503 }
504 
505 const FunctionType *
506 CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
507   switch (Kind) {
508   case CK_Function:
509     return Function->getType()->getAs<FunctionType>();
510 
511   case CK_FunctionTemplate:
512     return FunctionTemplate->getTemplatedDecl()
513         ->getType()
514         ->getAs<FunctionType>();
515 
516   case CK_FunctionType:
517     return Type;
518   case CK_FunctionProtoTypeLoc:
519     return ProtoTypeLoc.getTypePtr();
520   case CK_Template:
521   case CK_Aggregate:
522     return nullptr;
523   }
524 
525   llvm_unreachable("Invalid CandidateKind!");
526 }
527 
528 const FunctionProtoTypeLoc
529 CodeCompleteConsumer::OverloadCandidate::getFunctionProtoTypeLoc() const {
530   if (Kind == CK_FunctionProtoTypeLoc)
531     return ProtoTypeLoc;
532   return FunctionProtoTypeLoc();
533 }
534 
535 unsigned CodeCompleteConsumer::OverloadCandidate::getNumParams() const {
536   if (Kind == CK_Template)
537     return Template->getTemplateParameters()->size();
538 
539   if (Kind == CK_Aggregate) {
540     unsigned Count =
541         std::distance(AggregateType->field_begin(), AggregateType->field_end());
542     if (const auto *CRD = dyn_cast<CXXRecordDecl>(AggregateType))
543       Count += CRD->getNumBases();
544     return Count;
545   }
546 
547   if (const auto *FT = getFunctionType())
548     if (const auto *FPT = dyn_cast<FunctionProtoType>(FT))
549       return FPT->getNumParams();
550 
551   return 0;
552 }
553 
554 QualType
555 CodeCompleteConsumer::OverloadCandidate::getParamType(unsigned N) const {
556   if (Kind == CK_Aggregate) {
557     if (const auto *CRD = dyn_cast<CXXRecordDecl>(AggregateType)) {
558       if (N < CRD->getNumBases())
559         return std::next(CRD->bases_begin(), N)->getType();
560       N -= CRD->getNumBases();
561     }
562     for (const auto *Field : AggregateType->fields())
563       if (N-- == 0)
564         return Field->getType();
565     return QualType();
566   }
567 
568   if (Kind == CK_Template) {
569     TemplateParameterList *TPL = getTemplate()->getTemplateParameters();
570     if (N < TPL->size())
571       if (const auto *D = dyn_cast<NonTypeTemplateParmDecl>(TPL->getParam(N)))
572         return D->getType();
573     return QualType();
574   }
575 
576   if (const auto *FT = getFunctionType())
577     if (const auto *FPT = dyn_cast<FunctionProtoType>(FT))
578       if (N < FPT->getNumParams())
579         return FPT->getParamType(N);
580   return QualType();
581 }
582 
583 const NamedDecl *
584 CodeCompleteConsumer::OverloadCandidate::getParamDecl(unsigned N) const {
585   if (Kind == CK_Aggregate) {
586     if (const auto *CRD = dyn_cast<CXXRecordDecl>(AggregateType)) {
587       if (N < CRD->getNumBases())
588         return std::next(CRD->bases_begin(), N)->getType()->getAsTagDecl();
589       N -= CRD->getNumBases();
590     }
591     for (const auto *Field : AggregateType->fields())
592       if (N-- == 0)
593         return Field;
594     return nullptr;
595   }
596 
597   if (Kind == CK_Template) {
598     TemplateParameterList *TPL = getTemplate()->getTemplateParameters();
599     if (N < TPL->size())
600       return TPL->getParam(N);
601     return nullptr;
602   }
603 
604   // Note that if we only have a FunctionProtoType, we don't have param decls.
605   if (const auto *FD = getFunction()) {
606     if (N < FD->param_size())
607       return FD->getParamDecl(N);
608   } else if (Kind == CK_FunctionProtoTypeLoc) {
609     if (N < ProtoTypeLoc.getNumParams()) {
610       return ProtoTypeLoc.getParam(N);
611     }
612   }
613 
614   return nullptr;
615 }
616 
617 //===----------------------------------------------------------------------===//
618 // Code completion consumer implementation
619 //===----------------------------------------------------------------------===//
620 
621 CodeCompleteConsumer::~CodeCompleteConsumer() = default;
622 
623 bool PrintingCodeCompleteConsumer::isResultFilteredOut(
624     StringRef Filter, CodeCompletionResult Result) {
625   switch (Result.Kind) {
626   case CodeCompletionResult::RK_Declaration:
627     return !(Result.Declaration->getIdentifier() &&
628              Result.Declaration->getIdentifier()->getName().startswith(Filter));
629   case CodeCompletionResult::RK_Keyword:
630     return !StringRef(Result.Keyword).startswith(Filter);
631   case CodeCompletionResult::RK_Macro:
632     return !Result.Macro->getName().startswith(Filter);
633   case CodeCompletionResult::RK_Pattern:
634     return !(Result.Pattern->getTypedText() &&
635              StringRef(Result.Pattern->getTypedText()).startswith(Filter));
636   }
637   llvm_unreachable("Unknown code completion result Kind.");
638 }
639 
640 void PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(
641     Sema &SemaRef, CodeCompletionContext Context, CodeCompletionResult *Results,
642     unsigned NumResults) {
643   std::stable_sort(Results, Results + NumResults);
644 
645   if (!Context.getPreferredType().isNull())
646     OS << "PREFERRED-TYPE: " << Context.getPreferredType() << '\n';
647 
648   StringRef Filter = SemaRef.getPreprocessor().getCodeCompletionFilter();
649   // Print the completions.
650   for (unsigned I = 0; I != NumResults; ++I) {
651     if (!Filter.empty() && isResultFilteredOut(Filter, Results[I]))
652       continue;
653     OS << "COMPLETION: ";
654     switch (Results[I].Kind) {
655     case CodeCompletionResult::RK_Declaration:
656       OS << *Results[I].Declaration;
657       {
658         std::vector<std::string> Tags;
659         if (Results[I].Hidden)
660           Tags.push_back("Hidden");
661         if (Results[I].InBaseClass)
662           Tags.push_back("InBase");
663         if (Results[I].Availability ==
664             CXAvailabilityKind::CXAvailability_NotAccessible)
665           Tags.push_back("Inaccessible");
666         if (!Tags.empty())
667           OS << " (" << llvm::join(Tags, ",") << ")";
668       }
669       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
670               SemaRef, Context, getAllocator(), CCTUInfo,
671               includeBriefComments())) {
672         OS << " : " << CCS->getAsString();
673         if (const char *BriefComment = CCS->getBriefComment())
674           OS << " : " << BriefComment;
675       }
676       break;
677 
678     case CodeCompletionResult::RK_Keyword:
679       OS << Results[I].Keyword;
680       break;
681 
682     case CodeCompletionResult::RK_Macro:
683       OS << Results[I].Macro->getName();
684       if (CodeCompletionString *CCS = Results[I].CreateCodeCompletionString(
685               SemaRef, Context, getAllocator(), CCTUInfo,
686               includeBriefComments())) {
687         OS << " : " << CCS->getAsString();
688       }
689       break;
690 
691     case CodeCompletionResult::RK_Pattern:
692       OS << "Pattern : " << Results[I].Pattern->getAsString();
693       break;
694     }
695     for (const FixItHint &FixIt : Results[I].FixIts) {
696       const SourceLocation BLoc = FixIt.RemoveRange.getBegin();
697       const SourceLocation ELoc = FixIt.RemoveRange.getEnd();
698 
699       SourceManager &SM = SemaRef.SourceMgr;
700       std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(BLoc);
701       std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(ELoc);
702       // Adjust for token ranges.
703       if (FixIt.RemoveRange.isTokenRange())
704         EInfo.second += Lexer::MeasureTokenLength(ELoc, SM, SemaRef.LangOpts);
705 
706       OS << " (requires fix-it:"
707          << " {" << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
708          << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
709          << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
710          << SM.getColumnNumber(EInfo.first, EInfo.second) << "}"
711          << " to \"" << FixIt.CodeToInsert << "\")";
712     }
713     OS << '\n';
714   }
715 }
716 
717 // This function is used solely to preserve the former presentation of overloads
718 // by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
719 // needs to be improved for printing the newer and more detailed overload
720 // chunks.
721 static std::string getOverloadAsString(const CodeCompletionString &CCS) {
722   std::string Result;
723   llvm::raw_string_ostream OS(Result);
724 
725   for (auto &C : CCS) {
726     switch (C.Kind) {
727     case CodeCompletionString::CK_Informative:
728     case CodeCompletionString::CK_ResultType:
729       OS << "[#" << C.Text << "#]";
730       break;
731 
732     case CodeCompletionString::CK_CurrentParameter:
733       OS << "<#" << C.Text << "#>";
734       break;
735 
736     // FIXME: We can also print optional parameters of an overload.
737     case CodeCompletionString::CK_Optional:
738       break;
739 
740     default:
741       OS << C.Text;
742       break;
743     }
744   }
745   return Result;
746 }
747 
748 void PrintingCodeCompleteConsumer::ProcessOverloadCandidates(
749     Sema &SemaRef, unsigned CurrentArg, OverloadCandidate *Candidates,
750     unsigned NumCandidates, SourceLocation OpenParLoc, bool Braced) {
751   OS << "OPENING_PAREN_LOC: ";
752   OpenParLoc.print(OS, SemaRef.getSourceManager());
753   OS << "\n";
754 
755   for (unsigned I = 0; I != NumCandidates; ++I) {
756     if (CodeCompletionString *CCS = Candidates[I].CreateSignatureString(
757             CurrentArg, SemaRef, getAllocator(), CCTUInfo,
758             includeBriefComments(), Braced)) {
759       OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
760     }
761   }
762 }
763 
764 /// Retrieve the effective availability of the given declaration.
765 static AvailabilityResult getDeclAvailability(const Decl *D) {
766   AvailabilityResult AR = D->getAvailability();
767   if (isa<EnumConstantDecl>(D))
768     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
769   return AR;
770 }
771 
772 void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
773   switch (Kind) {
774   case RK_Pattern:
775     if (!Declaration) {
776       // Do nothing: Patterns can come with cursor kinds!
777       break;
778     }
779     [[fallthrough]];
780 
781   case RK_Declaration: {
782     // Set the availability based on attributes.
783     switch (getDeclAvailability(Declaration)) {
784     case AR_Available:
785     case AR_NotYetIntroduced:
786       Availability = CXAvailability_Available;
787       break;
788 
789     case AR_Deprecated:
790       Availability = CXAvailability_Deprecated;
791       break;
792 
793     case AR_Unavailable:
794       Availability = CXAvailability_NotAvailable;
795       break;
796     }
797 
798     if (const auto *Function = dyn_cast<FunctionDecl>(Declaration))
799       if (Function->isDeleted())
800         Availability = CXAvailability_NotAvailable;
801 
802     CursorKind = getCursorKindForDecl(Declaration);
803     if (CursorKind == CXCursor_UnexposedDecl) {
804       // FIXME: Forward declarations of Objective-C classes and protocols
805       // are not directly exposed, but we want code completion to treat them
806       // like a definition.
807       if (isa<ObjCInterfaceDecl>(Declaration))
808         CursorKind = CXCursor_ObjCInterfaceDecl;
809       else if (isa<ObjCProtocolDecl>(Declaration))
810         CursorKind = CXCursor_ObjCProtocolDecl;
811       else
812         CursorKind = CXCursor_NotImplemented;
813     }
814     break;
815   }
816 
817   case RK_Macro:
818   case RK_Keyword:
819     llvm_unreachable("Macro and keyword kinds are handled by the constructors");
820   }
821 
822   if (!Accessible)
823     Availability = CXAvailability_NotAccessible;
824 }
825 
826 /// Retrieve the name that should be used to order a result.
827 ///
828 /// If the name needs to be constructed as a string, that string will be
829 /// saved into Saved and the returned StringRef will refer to it.
830 StringRef CodeCompletionResult::getOrderedName(std::string &Saved) const {
831   switch (Kind) {
832   case RK_Keyword:
833     return Keyword;
834   case RK_Pattern:
835     return Pattern->getTypedText();
836   case RK_Macro:
837     return Macro->getName();
838   case RK_Declaration:
839     // Handle declarations below.
840     break;
841   }
842 
843   DeclarationName Name = Declaration->getDeclName();
844 
845   // If the name is a simple identifier (by far the common case), or a
846   // zero-argument selector, just return a reference to that identifier.
847   if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
848     return Id->getName();
849   if (Name.isObjCZeroArgSelector())
850     if (IdentifierInfo *Id = Name.getObjCSelector().getIdentifierInfoForSlot(0))
851       return Id->getName();
852 
853   Saved = Name.getAsString();
854   return Saved;
855 }
856 
857 bool clang::operator<(const CodeCompletionResult &X,
858                       const CodeCompletionResult &Y) {
859   std::string XSaved, YSaved;
860   StringRef XStr = X.getOrderedName(XSaved);
861   StringRef YStr = Y.getOrderedName(YSaved);
862   int cmp = XStr.compare_insensitive(YStr);
863   if (cmp)
864     return cmp < 0;
865 
866   // If case-insensitive comparison fails, try case-sensitive comparison.
867   return XStr.compare(YStr) < 0;
868 }
869