lib/Sema/CodeCompleteConsumer.cpp - third_party/swift-clang - Git at Google

 //===--- CodeCompleteConsumer.cpp - Code Completion Interface ---*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 //  This file implements the CodeCompleteConsumer class.
 //
 //===----------------------------------------------------------------------===//
 #include "clang/Sema/CodeCompleteConsumer.h"
 #include "clang-c/Index.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/Sema.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cstring>
 #include <functional>

 using namespace clang;

 //===----------------------------------------------------------------------===//
 // Code completion context implementation
 //===----------------------------------------------------------------------===//

 bool CodeCompletionContext::wantConstructorResults() const {
   switch (Kind) {
   case CCC_Recovery:
   case CCC_Statement:
   case CCC_Expression:
   case CCC_ObjCMessageReceiver:
   case CCC_ParenthesizedExpression:
     return true;

   case CCC_TopLevel:
   case CCC_ObjCInterface:
   case CCC_ObjCImplementation:
   case CCC_ObjCIvarList:
   case CCC_ClassStructUnion:
   case CCC_DotMemberAccess:
   case CCC_ArrowMemberAccess:
   case CCC_ObjCPropertyAccess:
   case CCC_EnumTag:
   case CCC_UnionTag:
   case CCC_ClassOrStructTag:
   case CCC_ObjCProtocolName:
   case CCC_Namespace:
   case CCC_Type:
   case CCC_Name:
   case CCC_PotentiallyQualifiedName:
   case CCC_MacroName:
   case CCC_MacroNameUse:
   case CCC_PreprocessorExpression:
   case CCC_PreprocessorDirective:
   case CCC_NaturalLanguage:
   case CCC_SelectorName:
   case CCC_TypeQualifiers:
   case CCC_Other:
   case CCC_OtherWithMacros:
   case CCC_ObjCInstanceMessage:
   case CCC_ObjCClassMessage:
   case CCC_ObjCInterfaceName:
   case CCC_ObjCCategoryName:
     return false;
   }

   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
 }

 //===----------------------------------------------------------------------===//
 // Code completion string implementation
 //===----------------------------------------------------------------------===//
 CodeCompletionString::Chunk::Chunk(ChunkKind Kind, const char *Text)
   : Kind(Kind), Text("")
 {
   switch (Kind) {
   case CK_TypedText:
   case CK_Text:
   case CK_Placeholder:
   case CK_Informative:
   case CK_ResultType:
   case CK_CurrentParameter:
     this->Text = Text;
     break;

   case CK_Optional:
     llvm_unreachable("Optional strings cannot be created from text");

   case CK_LeftParen:
     this->Text = "(";
     break;

   case CK_RightParen:
     this->Text = ")";
     break;

   case CK_LeftBracket:
     this->Text = "[";
     break;

   case CK_RightBracket:
     this->Text = "]";
     break;

   case CK_LeftBrace:
     this->Text = "{";
     break;

   case CK_RightBrace:
     this->Text = "}";
     break;

   case CK_LeftAngle:
     this->Text = "<";
     break;

   case CK_RightAngle:
     this->Text = ">";
     break;

   case CK_Comma:
     this->Text = ", ";
     break;

   case CK_Colon:
     this->Text = ":";
     break;

   case CK_SemiColon:
     this->Text = ";";
     break;

   case CK_Equal:
     this->Text = " = ";
     break;

   case CK_HorizontalSpace:
     this->Text = " ";
     break;

   case CK_VerticalSpace:
     this->Text = "\n";
     break;
   }
 }

 CodeCompletionString::Chunk
 CodeCompletionString::Chunk::CreateText(const char *Text) {
   return Chunk(CK_Text, Text);
 }

 CodeCompletionString::Chunk
 CodeCompletionString::Chunk::CreateOptional(CodeCompletionString *Optional) {
   Chunk Result;
   Result.Kind = CK_Optional;
   Result.Optional = Optional;
   return Result;
 }

 CodeCompletionString::Chunk
 CodeCompletionString::Chunk::CreatePlaceholder(const char *Placeholder) {
   return Chunk(CK_Placeholder, Placeholder);
 }

 CodeCompletionString::Chunk
 CodeCompletionString::Chunk::CreateInformative(const char *Informative) {
   return Chunk(CK_Informative, Informative);
 }

 CodeCompletionString::Chunk
 CodeCompletionString::Chunk::CreateResultType(const char *ResultType) {
   return Chunk(CK_ResultType, ResultType);
 }

 CodeCompletionString::Chunk
 CodeCompletionString::Chunk::CreateCurrentParameter(
                                                 const char *CurrentParameter) {
   return Chunk(CK_CurrentParameter, CurrentParameter);
 }

 CodeCompletionString::CodeCompletionString(const Chunk *Chunks,
                                            unsigned NumChunks,
                                            unsigned Priority,
                                            CXAvailabilityKind Availability,
                                            const char **Annotations,
                                            unsigned NumAnnotations,
                                            StringRef ParentName,
                                            const char *BriefComment)
   : NumChunks(NumChunks), NumAnnotations(NumAnnotations),
     Priority(Priority), Availability(Availability),
     ParentName(ParentName), BriefComment(BriefComment)
 {
   assert(NumChunks <= 0xffff);
   assert(NumAnnotations <= 0xffff);

   Chunk *StoredChunks = reinterpret_cast<Chunk *>(this + 1);
   for (unsigned I = 0; I != NumChunks; ++I)
     StoredChunks[I] = Chunks[I];

   const char **StoredAnnotations = reinterpret_cast<const char **>(StoredChunks + NumChunks);
   for (unsigned I = 0; I != NumAnnotations; ++I)
     StoredAnnotations[I] = Annotations[I];
 }

 unsigned CodeCompletionString::getAnnotationCount() const {
   return NumAnnotations;
 }

 const char *CodeCompletionString::getAnnotation(unsigned AnnotationNr) const {
   if (AnnotationNr < NumAnnotations)
     return reinterpret_cast<const char * const*>(end())[AnnotationNr];
   else
     return nullptr;
 }


 std::string CodeCompletionString::getAsString() const {
   std::string Result;
   llvm::raw_string_ostream OS(Result);

   for (iterator C = begin(), CEnd = end(); C != CEnd; ++C) {
     switch (C->Kind) {
     case CK_Optional: OS << "{#" << C->Optional->getAsString() << "#}"; break;
     case CK_Placeholder: OS << "<#" << C->Text << "#>"; break;

     case CK_Informative:
     case CK_ResultType:
       OS << "[#" << C->Text << "#]";
       break;

     case CK_CurrentParameter: OS << "<#" << C->Text << "#>"; break;
     default: OS << C->Text; break;
     }
   }
   return OS.str();
 }

 const char *CodeCompletionString::getTypedText() const {
   for (iterator C = begin(), CEnd = end(); C != CEnd; ++C)
     if (C->Kind == CK_TypedText)
       return C->Text;

   return nullptr;
 }

 const char *CodeCompletionAllocator::CopyString(const Twine &String) {
   SmallString<128> Data;
   StringRef Ref = String.toStringRef(Data);
   // FIXME: It would be more efficient to teach Twine to tell us its size and
   // then add a routine there to fill in an allocated char* with the contents
   // of the string.
   char *Mem = (char *)Allocate(Ref.size() + 1, 1);
   std::copy(Ref.begin(), Ref.end(), Mem);
   Mem[Ref.size()] = 0;
   return Mem;
 }

 StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
   if (!ND)
     return StringRef();

   // Check whether we've already cached the parent name.
   StringRef &CachedParentName = ParentNames[DC];
   if (!CachedParentName.empty())
     return CachedParentName;

   // If we already processed this DeclContext and assigned empty to it, the
   // data pointer will be non-null.
   if (CachedParentName.data() != nullptr)
     return StringRef();

   // Find the interesting names.
   SmallVector<const DeclContext *, 2> Contexts;
   while (DC && !DC->isFunctionOrMethod()) {
     if (const NamedDecl *ND = dyn_cast<NamedDecl>(DC)) {
       if (ND->getIdentifier())
         Contexts.push_back(DC);
     }

     DC = DC->getParent();
   }

   {
     SmallString<128> S;
     llvm::raw_svector_ostream OS(S);
     bool First = true;
     for (unsigned I = Contexts.size(); I != 0; --I) {
       if (First)
         First = false;
       else {
         OS << "::";
       }

       const DeclContext *CurDC = Contexts[I-1];
       if (const ObjCCategoryImplDecl *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
         CurDC = CatImpl->getCategoryDecl();

       if (const ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
         const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
         if (!Interface) {
           // Assign an empty StringRef but with non-null data to distinguish
           // between empty because we didn't process the DeclContext yet.
           CachedParentName = StringRef((const char *)~0U, 0);
           return StringRef();
         }

         OS << Interface->getName() << '(' << Cat->getName() << ')';
       } else {
         OS << cast<NamedDecl>(CurDC)->getName();
       }
     }

     CachedParentName = AllocatorRef->CopyString(OS.str());
   }

   return CachedParentName;
 }

 CodeCompletionString *CodeCompletionBuilder::TakeString() {
   void *Mem = getAllocator().Allocate(
                   sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size()
                                     + sizeof(const char *) * Annotations.size(),
                                  llvm::alignOf<CodeCompletionString>());
   CodeCompletionString *Result
     = new (Mem) CodeCompletionString(Chunks.data(), Chunks.size(),
                                      Priority, Availability,
                                      Annotations.data(), Annotations.size(),
                                      ParentName, BriefComment);
   Chunks.clear();
   return Result;
 }

 void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
   Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
 }

 void CodeCompletionBuilder::AddTextChunk(const char *Text) {
   Chunks.push_back(Chunk::CreateText(Text));
 }

 void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
   Chunks.push_back(Chunk::CreateOptional(Optional));
 }

 void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
   Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
 }

 void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
   Chunks.push_back(Chunk::CreateInformative(Text));
 }

 void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
   Chunks.push_back(Chunk::CreateResultType(ResultType));
 }

 void
 CodeCompletionBuilder::AddCurrentParameterChunk(const char *CurrentParameter) {
   Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
 }

 void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
                                      const char *Text) {
   Chunks.push_back(Chunk(CK, Text));
 }

 void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
   if (DC->isTranslationUnit()) {
     return;
   }

   if (DC->isFunctionOrMethod())
     return;

   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
   if (!ND)
     return;

   ParentName = getCodeCompletionTUInfo().getParentName(DC);
 }

 void CodeCompletionBuilder::addBriefComment(StringRef Comment) {
   BriefComment = Allocator.CopyString(Comment);
 }

 //===----------------------------------------------------------------------===//
 // Code completion overload candidate implementation
 //===----------------------------------------------------------------------===//
 FunctionDecl *
 CodeCompleteConsumer::OverloadCandidate::getFunction() const {
   if (getKind() == CK_Function)
     return Function;
   else if (getKind() == CK_FunctionTemplate)
     return FunctionTemplate->getTemplatedDecl();
   else
     return nullptr;
 }

 const FunctionType *
 CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
   switch (Kind) {
   case CK_Function:
     return Function->getType()->getAs<FunctionType>();

   case CK_FunctionTemplate:
     return FunctionTemplate->getTemplatedDecl()->getType()
              ->getAs<FunctionType>();

   case CK_FunctionType:
     return Type;
   }

   llvm_unreachable("Invalid CandidateKind!");
 }

 //===----------------------------------------------------------------------===//
 // Code completion consumer implementation
 //===----------------------------------------------------------------------===//

 CodeCompleteConsumer::~CodeCompleteConsumer() { }

 void
 PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &SemaRef,
                                                  CodeCompletionContext Context,
                                                  CodeCompletionResult *Results,
                                                          unsigned NumResults) {
   std::stable_sort(Results, Results + NumResults);

   // Print the results.
   for (unsigned I = 0; I != NumResults; ++I) {
     OS << "COMPLETION: ";
     switch (Results[I].Kind) {
     case CodeCompletionResult::RK_Declaration:
       OS << *Results[I].Declaration;
       if (Results[I].Hidden)
         OS << " (Hidden)";
       if (CodeCompletionString *CCS
             = Results[I].CreateCodeCompletionString(SemaRef, Context,
                                                     getAllocator(),
                                                     CCTUInfo,
                                                     includeBriefComments())) {
         OS << " : " << CCS->getAsString();
         if (const char *BriefComment = CCS->getBriefComment())
           OS << " : " << BriefComment;
       }

       OS << '\n';
       break;

     case CodeCompletionResult::RK_Keyword:
       OS << Results[I].Keyword << '\n';
       break;

     case CodeCompletionResult::RK_Macro: {
       OS << Results[I].Macro->getName();
       if (CodeCompletionString *CCS
             = Results[I].CreateCodeCompletionString(SemaRef, Context,
                                                     getAllocator(),
                                                     CCTUInfo,
                                                     includeBriefComments())) {
         OS << " : " << CCS->getAsString();
       }
       OS << '\n';
       break;
     }

     case CodeCompletionResult::RK_Pattern: {
       OS << "Pattern : "
          << Results[I].Pattern->getAsString() << '\n';
       break;
     }
     }
   }
 }

 // This function is used solely to preserve the former presentation of overloads
 // by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
 // needs to be improved for printing the newer and more detailed overload
 // chunks.
 static std::string getOverloadAsString(const CodeCompletionString &CCS) {
   std::string Result;
   llvm::raw_string_ostream OS(Result);

   for (auto &C : CCS) {
     switch (C.Kind) {
     case CodeCompletionString::CK_Informative:
     case CodeCompletionString::CK_ResultType:
       OS << "[#" << C.Text << "#]";
       break;

     case CodeCompletionString::CK_CurrentParameter:
       OS << "<#" << C.Text << "#>";
       break;

     default: OS << C.Text; break;
     }
   }
   return OS.str();
 }

 void
 PrintingCodeCompleteConsumer::ProcessOverloadCandidates(Sema &SemaRef,
                                                         unsigned CurrentArg,
                                               OverloadCandidate *Candidates,
                                                      unsigned NumCandidates) {
   for (unsigned I = 0; I != NumCandidates; ++I) {
     if (CodeCompletionString *CCS
           = Candidates[I].CreateSignatureString(CurrentArg, SemaRef,
                                                 getAllocator(), CCTUInfo,
                                                 includeBriefComments())) {
       OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
     }
   }
 }

 /// \brief Retrieve the effective availability of the given declaration.
 static AvailabilityResult getDeclAvailability(const Decl *D) {
   AvailabilityResult AR = D->getAvailability();
   if (isa<EnumConstantDecl>(D))
     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
   return AR;
 }

 void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
   switch (Kind) {
   case RK_Pattern:
     if (!Declaration) {
       // Do nothing: Patterns can come with cursor kinds!
       break;
     }
     // Fall through

   case RK_Declaration: {
     // Set the availability based on attributes.
     switch (getDeclAvailability(Declaration)) {
     case AR_Available:
     case AR_NotYetIntroduced:
       Availability = CXAvailability_Available;
       break;

     case AR_Deprecated:
       Availability = CXAvailability_Deprecated;
       break;

     case AR_Unavailable:
       Availability = CXAvailability_NotAvailable;
       break;
     }

     if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Declaration))
       if (Function->isDeleted())
         Availability = CXAvailability_NotAvailable;

     CursorKind = getCursorKindForDecl(Declaration);
     if (CursorKind == CXCursor_UnexposedDecl) {
       // FIXME: Forward declarations of Objective-C classes and protocols
       // are not directly exposed, but we want code completion to treat them
       // like a definition.
       if (isa<ObjCInterfaceDecl>(Declaration))
         CursorKind = CXCursor_ObjCInterfaceDecl;
       else if (isa<ObjCProtocolDecl>(Declaration))
         CursorKind = CXCursor_ObjCProtocolDecl;
       else
         CursorKind = CXCursor_NotImplemented;
     }
     break;
   }

   case RK_Macro:
   case RK_Keyword:
     llvm_unreachable("Macro and keyword kinds are handled by the constructors");
   }

   if (!Accessible)
     Availability = CXAvailability_NotAccessible;
 }

 /// \brief Retrieve the name that should be used to order a result.
 ///
 /// If the name needs to be constructed as a string, that string will be
 /// saved into Saved and the returned StringRef will refer to it.
 static StringRef getOrderedName(const CodeCompletionResult &R,
                                     std::string &Saved) {
   switch (R.Kind) {
     case CodeCompletionResult::RK_Keyword:
       return R.Keyword;

     case CodeCompletionResult::RK_Pattern:
       return R.Pattern->getTypedText();

     case CodeCompletionResult::RK_Macro:
       return R.Macro->getName();

     case CodeCompletionResult::RK_Declaration:
       // Handle declarations below.
       break;
   }

   DeclarationName Name = R.Declaration->getDeclName();

   // If the name is a simple identifier (by far the common case), or a
   // zero-argument selector, just return a reference to that identifier.
   if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
     return Id->getName();
   if (Name.isObjCZeroArgSelector())
     if (IdentifierInfo *Id
         = Name.getObjCSelector().getIdentifierInfoForSlot(0))
       return Id->getName();

   Saved = Name.getAsString();
   return Saved;
 }

 bool clang::operator<(const CodeCompletionResult &X,
                       const CodeCompletionResult &Y) {
   std::string XSaved, YSaved;
   StringRef XStr = getOrderedName(X, XSaved);
   StringRef YStr = getOrderedName(Y, YSaved);
   int cmp = XStr.compare_lower(YStr);
   if (cmp)
     return cmp < 0;

   // If case-insensitive comparison fails, try case-sensitive comparison.
   cmp = XStr.compare(YStr);
   if (cmp)
     return cmp < 0;

   return false;
 }
	//===--- CodeCompleteConsumer.cpp - Code Completion Interface ---- C++ --===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This file implements the CodeCompleteConsumer class.
	//
	//===----------------------------------------------------------------------===//
	#include "clang/Sema/CodeCompleteConsumer.h"
	#include "clang-c/Index.h"
	#include "clang/AST/DeclCXX.h"
	#include "clang/AST/DeclObjC.h"
	#include "clang/AST/DeclTemplate.h"
	#include "clang/Sema/Scope.h"
	#include "clang/Sema/Sema.h"
	#include "llvm/ADT/STLExtras.h"
	#include "llvm/ADT/SmallString.h"
	#include "llvm/ADT/Twine.h"
	#include "llvm/Support/raw_ostream.h"
	#include <algorithm>
	#include <cstring>
	#include <functional>

	using namespace clang;

	//===----------------------------------------------------------------------===//
	// Code completion context implementation
	//===----------------------------------------------------------------------===//

	bool CodeCompletionContext::wantConstructorResults() const {
	switch (Kind) {
	case CCC_Recovery:
	case CCC_Statement:
	case CCC_Expression:
	case CCC_ObjCMessageReceiver:
	case CCC_ParenthesizedExpression:
	return true;

	case CCC_TopLevel:
	case CCC_ObjCInterface:
	case CCC_ObjCImplementation:
	case CCC_ObjCIvarList:
	case CCC_ClassStructUnion:
	case CCC_DotMemberAccess:
	case CCC_ArrowMemberAccess:
	case CCC_ObjCPropertyAccess:
	case CCC_EnumTag:
	case CCC_UnionTag:
	case CCC_ClassOrStructTag:
	case CCC_ObjCProtocolName:
	case CCC_Namespace:
	case CCC_Type:
	case CCC_Name:
	case CCC_PotentiallyQualifiedName:
	case CCC_MacroName:
	case CCC_MacroNameUse:
	case CCC_PreprocessorExpression:
	case CCC_PreprocessorDirective:
	case CCC_NaturalLanguage:
	case CCC_SelectorName:
	case CCC_TypeQualifiers:
	case CCC_Other:
	case CCC_OtherWithMacros:
	case CCC_ObjCInstanceMessage:
	case CCC_ObjCClassMessage:
	case CCC_ObjCInterfaceName:
	case CCC_ObjCCategoryName:
	return false;
	}

	llvm_unreachable("Invalid CodeCompletionContext::Kind!");
	}

	//===----------------------------------------------------------------------===//
	// Code completion string implementation
	//===----------------------------------------------------------------------===//
	CodeCompletionString::Chunk::Chunk(ChunkKind Kind, const char *Text)
	: Kind(Kind), Text("")
	{
	switch (Kind) {
	case CK_TypedText:
	case CK_Text:
	case CK_Placeholder:
	case CK_Informative:
	case CK_ResultType:
	case CK_CurrentParameter:
	this->Text = Text;
	break;

	case CK_Optional:
	llvm_unreachable("Optional strings cannot be created from text");

	case CK_LeftParen:
	this->Text = "(";
	break;

	case CK_RightParen:
	this->Text = ")";
	break;

	case CK_LeftBracket:
	this->Text = "[";
	break;

	case CK_RightBracket:
	this->Text = "]";
	break;

	case CK_LeftBrace:
	this->Text = "{";
	break;

	case CK_RightBrace:
	this->Text = "}";
	break;

	case CK_LeftAngle:
	this->Text = "<";
	break;

	case CK_RightAngle:
	this->Text = ">";
	break;

	case CK_Comma:
	this->Text = ", ";
	break;

	case CK_Colon:
	this->Text = ":";
	break;

	case CK_SemiColon:
	this->Text = ";";
	break;

	case CK_Equal:
	this->Text = " = ";
	break;

	case CK_HorizontalSpace:
	this->Text = " ";
	break;

	case CK_VerticalSpace:
	this->Text = "\n";
	break;
	}
	}

	CodeCompletionString::Chunk
	CodeCompletionString::Chunk::CreateText(const char *Text) {
	return Chunk(CK_Text, Text);
	}

	CodeCompletionString::Chunk
	CodeCompletionString::Chunk::CreateOptional(CodeCompletionString *Optional) {
	Chunk Result;
	Result.Kind = CK_Optional;
	Result.Optional = Optional;
	return Result;
	}

	CodeCompletionString::Chunk
	CodeCompletionString::Chunk::CreatePlaceholder(const char *Placeholder) {
	return Chunk(CK_Placeholder, Placeholder);
	}

	CodeCompletionString::Chunk
	CodeCompletionString::Chunk::CreateInformative(const char *Informative) {
	return Chunk(CK_Informative, Informative);
	}

	CodeCompletionString::Chunk
	CodeCompletionString::Chunk::CreateResultType(const char *ResultType) {
	return Chunk(CK_ResultType, ResultType);
	}

	CodeCompletionString::Chunk
	CodeCompletionString::Chunk::CreateCurrentParameter(
	const char *CurrentParameter) {
	return Chunk(CK_CurrentParameter, CurrentParameter);
	}

	CodeCompletionString::CodeCompletionString(const Chunk *Chunks,
	unsigned NumChunks,
	unsigned Priority,
	CXAvailabilityKind Availability,
	const char **Annotations,
	unsigned NumAnnotations,
	StringRef ParentName,
	const char *BriefComment)
	: NumChunks(NumChunks), NumAnnotations(NumAnnotations),
	Priority(Priority), Availability(Availability),
	ParentName(ParentName), BriefComment(BriefComment)
	{
	assert(NumChunks <= 0xffff);
	assert(NumAnnotations <= 0xffff);

	Chunk StoredChunks = reinterpret_cast<Chunk >(this + 1);
	for (unsigned I = 0; I != NumChunks; ++I)
	StoredChunks[I] = Chunks[I];

	const char StoredAnnotations = reinterpret_cast<const char >(StoredChunks + NumChunks);
	for (unsigned I = 0; I != NumAnnotations; ++I)
	StoredAnnotations[I] = Annotations[I];
	}

	unsigned CodeCompletionString::getAnnotationCount() const {
	return NumAnnotations;
	}

	const char *CodeCompletionString::getAnnotation(unsigned AnnotationNr) const {
	if (AnnotationNr < NumAnnotations)
	return reinterpret_cast<const char * const*>(end())[AnnotationNr];
	else
	return nullptr;
	}


	std::string CodeCompletionString::getAsString() const {
	std::string Result;
	llvm::raw_string_ostream OS(Result);

	for (iterator C = begin(), CEnd = end(); C != CEnd; ++C) {
	switch (C->Kind) {
	case CK_Optional: OS << "{#" << C->Optional->getAsString() << "#}"; break;
	case CK_Placeholder: OS << "<#" << C->Text << "#>"; break;

	case CK_Informative:
	case CK_ResultType:
	OS << "[#" << C->Text << "#]";
	break;

	case CK_CurrentParameter: OS << "<#" << C->Text << "#>"; break;
	default: OS << C->Text; break;
	}
	}
	return OS.str();
	}

	const char *CodeCompletionString::getTypedText() const {
	for (iterator C = begin(), CEnd = end(); C != CEnd; ++C)
	if (C->Kind == CK_TypedText)
	return C->Text;

	return nullptr;
	}

	const char *CodeCompletionAllocator::CopyString(const Twine &String) {
	SmallString<128> Data;
	StringRef Ref = String.toStringRef(Data);
	// FIXME: It would be more efficient to teach Twine to tell us its size and
	// then add a routine there to fill in an allocated char* with the contents
	// of the string.
	char Mem = (char )Allocate(Ref.size() + 1, 1);
	std::copy(Ref.begin(), Ref.end(), Mem);
	Mem[Ref.size()] = 0;
	return Mem;
	}

	StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
	const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
	if (!ND)
	return StringRef();

	// Check whether we've already cached the parent name.
	StringRef &CachedParentName = ParentNames[DC];
	if (!CachedParentName.empty())
	return CachedParentName;

	// If we already processed this DeclContext and assigned empty to it, the
	// data pointer will be non-null.
	if (CachedParentName.data() != nullptr)
	return StringRef();

	// Find the interesting names.
	SmallVector<const DeclContext *, 2> Contexts;
	while (DC && !DC->isFunctionOrMethod()) {
	if (const NamedDecl *ND = dyn_cast<NamedDecl>(DC)) {
	if (ND->getIdentifier())
	Contexts.push_back(DC);
	}

	DC = DC->getParent();
	}

	{
	SmallString<128> S;
	llvm::raw_svector_ostream OS(S);
	bool First = true;
	for (unsigned I = Contexts.size(); I != 0; --I) {
	if (First)
	First = false;
	else {
	OS << "::";
	}

	const DeclContext *CurDC = Contexts[I-1];
	if (const ObjCCategoryImplDecl *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
	CurDC = CatImpl->getCategoryDecl();

	if (const ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
	const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
	if (!Interface) {
	// Assign an empty StringRef but with non-null data to distinguish
	// between empty because we didn't process the DeclContext yet.
	CachedParentName = StringRef((const char *)~0U, 0);
	return StringRef();
	}

	OS << Interface->getName() << '(' << Cat->getName() << ')';
	} else {
	OS << cast<NamedDecl>(CurDC)->getName();
	}
	}

	CachedParentName = AllocatorRef->CopyString(OS.str());
	}

	return CachedParentName;
	}

	CodeCompletionString *CodeCompletionBuilder::TakeString() {
	void *Mem = getAllocator().Allocate(
	sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size()
	+ sizeof(const char ) Annotations.size(),
	llvm::alignOf<CodeCompletionString>());
	CodeCompletionString *Result
	= new (Mem) CodeCompletionString(Chunks.data(), Chunks.size(),
	Priority, Availability,
	Annotations.data(), Annotations.size(),
	ParentName, BriefComment);
	Chunks.clear();
	return Result;
	}

	void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
	Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
	}

	void CodeCompletionBuilder::AddTextChunk(const char *Text) {
	Chunks.push_back(Chunk::CreateText(Text));
	}

	void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
	Chunks.push_back(Chunk::CreateOptional(Optional));
	}

	void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
	Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
	}

	void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
	Chunks.push_back(Chunk::CreateInformative(Text));
	}

	void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
	Chunks.push_back(Chunk::CreateResultType(ResultType));
	}

	void
	CodeCompletionBuilder::AddCurrentParameterChunk(const char *CurrentParameter) {
	Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
	}

	void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
	const char *Text) {
	Chunks.push_back(Chunk(CK, Text));
	}

	void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
	if (DC->isTranslationUnit()) {
	return;
	}

	if (DC->isFunctionOrMethod())
	return;

	const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
	if (!ND)
	return;

	ParentName = getCodeCompletionTUInfo().getParentName(DC);
	}

	void CodeCompletionBuilder::addBriefComment(StringRef Comment) {
	BriefComment = Allocator.CopyString(Comment);
	}

	//===----------------------------------------------------------------------===//
	// Code completion overload candidate implementation
	//===----------------------------------------------------------------------===//
	FunctionDecl *
	CodeCompleteConsumer::OverloadCandidate::getFunction() const {
	if (getKind() == CK_Function)
	return Function;
	else if (getKind() == CK_FunctionTemplate)
	return FunctionTemplate->getTemplatedDecl();
	else
	return nullptr;
	}

	const FunctionType *
	CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
	switch (Kind) {
	case CK_Function:
	return Function->getType()->getAs<FunctionType>();

	case CK_FunctionTemplate:
	return FunctionTemplate->getTemplatedDecl()->getType()
	->getAs<FunctionType>();

	case CK_FunctionType:
	return Type;
	}

	llvm_unreachable("Invalid CandidateKind!");
	}

	//===----------------------------------------------------------------------===//
	// Code completion consumer implementation
	//===----------------------------------------------------------------------===//

	CodeCompleteConsumer::~CodeCompleteConsumer() { }

	void
	PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &SemaRef,
	CodeCompletionContext Context,
	CodeCompletionResult *Results,
	unsigned NumResults) {
	std::stable_sort(Results, Results + NumResults);

	// Print the results.
	for (unsigned I = 0; I != NumResults; ++I) {
	OS << "COMPLETION: ";
	switch (Results[I].Kind) {
	case CodeCompletionResult::RK_Declaration:
	OS << *Results[I].Declaration;
	if (Results[I].Hidden)
	OS << " (Hidden)";
	if (CodeCompletionString *CCS
	= Results[I].CreateCodeCompletionString(SemaRef, Context,
	getAllocator(),
	CCTUInfo,
	includeBriefComments())) {
	OS << " : " << CCS->getAsString();
	if (const char *BriefComment = CCS->getBriefComment())
	OS << " : " << BriefComment;
	}

	OS << '\n';
	break;

	case CodeCompletionResult::RK_Keyword:
	OS << Results[I].Keyword << '\n';
	break;

	case CodeCompletionResult::RK_Macro: {
	OS << Results[I].Macro->getName();
	if (CodeCompletionString *CCS
	= Results[I].CreateCodeCompletionString(SemaRef, Context,
	getAllocator(),
	CCTUInfo,
	includeBriefComments())) {
	OS << " : " << CCS->getAsString();
	}
	OS << '\n';
	break;
	}

	case CodeCompletionResult::RK_Pattern: {
	OS << "Pattern : "
	<< Results[I].Pattern->getAsString() << '\n';
	break;
	}
	}
	}
	}

	// This function is used solely to preserve the former presentation of overloads
	// by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
	// needs to be improved for printing the newer and more detailed overload
	// chunks.
	static std::string getOverloadAsString(const CodeCompletionString &CCS) {
	std::string Result;
	llvm::raw_string_ostream OS(Result);

	for (auto &C : CCS) {
	switch (C.Kind) {
	case CodeCompletionString::CK_Informative:
	case CodeCompletionString::CK_ResultType:
	OS << "[#" << C.Text << "#]";
	break;

	case CodeCompletionString::CK_CurrentParameter:
	OS << "<#" << C.Text << "#>";
	break;

	default: OS << C.Text; break;
	}
	}
	return OS.str();
	}

	void
	PrintingCodeCompleteConsumer::ProcessOverloadCandidates(Sema &SemaRef,
	unsigned CurrentArg,
	OverloadCandidate *Candidates,
	unsigned NumCandidates) {
	for (unsigned I = 0; I != NumCandidates; ++I) {
	if (CodeCompletionString *CCS
	= Candidates[I].CreateSignatureString(CurrentArg, SemaRef,
	getAllocator(), CCTUInfo,
	includeBriefComments())) {
	OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
	}
	}
	}

	/// \brief Retrieve the effective availability of the given declaration.
	static AvailabilityResult getDeclAvailability(const Decl *D) {
	AvailabilityResult AR = D->getAvailability();
	if (isa<EnumConstantDecl>(D))
	AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
	return AR;
	}

	void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
	switch (Kind) {
	case RK_Pattern:
	if (!Declaration) {
	// Do nothing: Patterns can come with cursor kinds!
	break;
	}
	// Fall through

	case RK_Declaration: {
	// Set the availability based on attributes.
	switch (getDeclAvailability(Declaration)) {
	case AR_Available:
	case AR_NotYetIntroduced:
	Availability = CXAvailability_Available;
	break;

	case AR_Deprecated:
	Availability = CXAvailability_Deprecated;
	break;

	case AR_Unavailable:
	Availability = CXAvailability_NotAvailable;
	break;
	}

	if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Declaration))
	if (Function->isDeleted())
	Availability = CXAvailability_NotAvailable;

	CursorKind = getCursorKindForDecl(Declaration);
	if (CursorKind == CXCursor_UnexposedDecl) {
	// FIXME: Forward declarations of Objective-C classes and protocols
	// are not directly exposed, but we want code completion to treat them
	// like a definition.
	if (isa<ObjCInterfaceDecl>(Declaration))
	CursorKind = CXCursor_ObjCInterfaceDecl;
	else if (isa<ObjCProtocolDecl>(Declaration))
	CursorKind = CXCursor_ObjCProtocolDecl;
	else
	CursorKind = CXCursor_NotImplemented;
	}
	break;
	}

	case RK_Macro:
	case RK_Keyword:
	llvm_unreachable("Macro and keyword kinds are handled by the constructors");
	}

	if (!Accessible)
	Availability = CXAvailability_NotAccessible;
	}

	/// \brief Retrieve the name that should be used to order a result.
	///
	/// If the name needs to be constructed as a string, that string will be
	/// saved into Saved and the returned StringRef will refer to it.
	static StringRef getOrderedName(const CodeCompletionResult &R,
	std::string &Saved) {
	switch (R.Kind) {
	case CodeCompletionResult::RK_Keyword:
	return R.Keyword;

	case CodeCompletionResult::RK_Pattern:
	return R.Pattern->getTypedText();

	case CodeCompletionResult::RK_Macro:
	return R.Macro->getName();

	case CodeCompletionResult::RK_Declaration:
	// Handle declarations below.
	break;
	}

	DeclarationName Name = R.Declaration->getDeclName();

	// If the name is a simple identifier (by far the common case), or a
	// zero-argument selector, just return a reference to that identifier.
	if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
	return Id->getName();
	if (Name.isObjCZeroArgSelector())
	if (IdentifierInfo *Id
	= Name.getObjCSelector().getIdentifierInfoForSlot(0))
	return Id->getName();

	Saved = Name.getAsString();
	return Saved;
	}

	bool clang::operator<(const CodeCompletionResult &X,
	const CodeCompletionResult &Y) {
	std::string XSaved, YSaved;
	StringRef XStr = getOrderedName(X, XSaved);
	StringRef YStr = getOrderedName(Y, YSaved);
	int cmp = XStr.compare_lower(YStr);
	if (cmp)
	return cmp < 0;

	// If case-insensitive comparison fails, try case-sensitive comparison.
	cmp = XStr.compare(YStr);
	if (cmp)
	return cmp < 0;

	return false;
	}