clang/lib/Sema/CodeCompleteConsumer.cpp

   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 }