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      1 //===--- CodeCompleteConsumer.cpp - Code Completion Interface ---*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 //  This file implements the CodeCompleteConsumer class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 #include "clang/Sema/CodeCompleteConsumer.h"
     14 #include "clang-c/Index.h"
     15 #include "clang/AST/DeclCXX.h"
     16 #include "clang/AST/DeclObjC.h"
     17 #include "clang/AST/DeclTemplate.h"
     18 #include "clang/Sema/Scope.h"
     19 #include "clang/Sema/Sema.h"
     20 #include "llvm/ADT/STLExtras.h"
     21 #include "llvm/ADT/SmallString.h"
     22 #include "llvm/ADT/Twine.h"
     23 #include "llvm/Support/raw_ostream.h"
     24 #include <algorithm>
     25 #include <cstring>
     26 #include <functional>
     27 
     28 using namespace clang;
     29 
     30 //===----------------------------------------------------------------------===//
     31 // Code completion context implementation
     32 //===----------------------------------------------------------------------===//
     33 
     34 bool CodeCompletionContext::wantConstructorResults() const {
     35   switch (Kind) {
     36   case CCC_Recovery:
     37   case CCC_Statement:
     38   case CCC_Expression:
     39   case CCC_ObjCMessageReceiver:
     40   case CCC_ParenthesizedExpression:
     41     return true;
     42 
     43   case CCC_TopLevel:
     44   case CCC_ObjCInterface:
     45   case CCC_ObjCImplementation:
     46   case CCC_ObjCIvarList:
     47   case CCC_ClassStructUnion:
     48   case CCC_DotMemberAccess:
     49   case CCC_ArrowMemberAccess:
     50   case CCC_ObjCPropertyAccess:
     51   case CCC_EnumTag:
     52   case CCC_UnionTag:
     53   case CCC_ClassOrStructTag:
     54   case CCC_ObjCProtocolName:
     55   case CCC_Namespace:
     56   case CCC_Type:
     57   case CCC_Name:
     58   case CCC_PotentiallyQualifiedName:
     59   case CCC_MacroName:
     60   case CCC_MacroNameUse:
     61   case CCC_PreprocessorExpression:
     62   case CCC_PreprocessorDirective:
     63   case CCC_NaturalLanguage:
     64   case CCC_SelectorName:
     65   case CCC_TypeQualifiers:
     66   case CCC_Other:
     67   case CCC_OtherWithMacros:
     68   case CCC_ObjCInstanceMessage:
     69   case CCC_ObjCClassMessage:
     70   case CCC_ObjCInterfaceName:
     71   case CCC_ObjCCategoryName:
     72     return false;
     73   }
     74 
     75   llvm_unreachable("Invalid CodeCompletionContext::Kind!");
     76 }
     77 
     78 //===----------------------------------------------------------------------===//
     79 // Code completion string implementation
     80 //===----------------------------------------------------------------------===//
     81 CodeCompletionString::Chunk::Chunk(ChunkKind Kind, const char *Text)
     82   : Kind(Kind), Text("")
     83 {
     84   switch (Kind) {
     85   case CK_TypedText:
     86   case CK_Text:
     87   case CK_Placeholder:
     88   case CK_Informative:
     89   case CK_ResultType:
     90   case CK_CurrentParameter:
     91     this->Text = Text;
     92     break;
     93 
     94   case CK_Optional:
     95     llvm_unreachable("Optional strings cannot be created from text");
     96 
     97   case CK_LeftParen:
     98     this->Text = "(";
     99     break;
    100 
    101   case CK_RightParen:
    102     this->Text = ")";
    103     break;
    104 
    105   case CK_LeftBracket:
    106     this->Text = "[";
    107     break;
    108 
    109   case CK_RightBracket:
    110     this->Text = "]";
    111     break;
    112 
    113   case CK_LeftBrace:
    114     this->Text = "{";
    115     break;
    116 
    117   case CK_RightBrace:
    118     this->Text = "}";
    119     break;
    120 
    121   case CK_LeftAngle:
    122     this->Text = "<";
    123     break;
    124 
    125   case CK_RightAngle:
    126     this->Text = ">";
    127     break;
    128 
    129   case CK_Comma:
    130     this->Text = ", ";
    131     break;
    132 
    133   case CK_Colon:
    134     this->Text = ":";
    135     break;
    136 
    137   case CK_SemiColon:
    138     this->Text = ";";
    139     break;
    140 
    141   case CK_Equal:
    142     this->Text = " = ";
    143     break;
    144 
    145   case CK_HorizontalSpace:
    146     this->Text = " ";
    147     break;
    148 
    149   case CK_VerticalSpace:
    150     this->Text = "\n";
    151     break;
    152   }
    153 }
    154 
    155 CodeCompletionString::Chunk
    156 CodeCompletionString::Chunk::CreateText(const char *Text) {
    157   return Chunk(CK_Text, Text);
    158 }
    159 
    160 CodeCompletionString::Chunk
    161 CodeCompletionString::Chunk::CreateOptional(CodeCompletionString *Optional) {
    162   Chunk Result;
    163   Result.Kind = CK_Optional;
    164   Result.Optional = Optional;
    165   return Result;
    166 }
    167 
    168 CodeCompletionString::Chunk
    169 CodeCompletionString::Chunk::CreatePlaceholder(const char *Placeholder) {
    170   return Chunk(CK_Placeholder, Placeholder);
    171 }
    172 
    173 CodeCompletionString::Chunk
    174 CodeCompletionString::Chunk::CreateInformative(const char *Informative) {
    175   return Chunk(CK_Informative, Informative);
    176 }
    177 
    178 CodeCompletionString::Chunk
    179 CodeCompletionString::Chunk::CreateResultType(const char *ResultType) {
    180   return Chunk(CK_ResultType, ResultType);
    181 }
    182 
    183 CodeCompletionString::Chunk
    184 CodeCompletionString::Chunk::CreateCurrentParameter(
    185                                                 const char *CurrentParameter) {
    186   return Chunk(CK_CurrentParameter, CurrentParameter);
    187 }
    188 
    189 CodeCompletionString::CodeCompletionString(const Chunk *Chunks,
    190                                            unsigned NumChunks,
    191                                            unsigned Priority,
    192                                            CXAvailabilityKind Availability,
    193                                            const char **Annotations,
    194                                            unsigned NumAnnotations,
    195                                            StringRef ParentName,
    196                                            const char *BriefComment)
    197   : NumChunks(NumChunks), NumAnnotations(NumAnnotations),
    198     Priority(Priority), Availability(Availability),
    199     ParentName(ParentName), BriefComment(BriefComment)
    200 {
    201   assert(NumChunks <= 0xffff);
    202   assert(NumAnnotations <= 0xffff);
    203 
    204   Chunk *StoredChunks = reinterpret_cast<Chunk *>(this + 1);
    205   for (unsigned I = 0; I != NumChunks; ++I)
    206     StoredChunks[I] = Chunks[I];
    207 
    208   const char **StoredAnnotations = reinterpret_cast<const char **>(StoredChunks + NumChunks);
    209   for (unsigned I = 0; I != NumAnnotations; ++I)
    210     StoredAnnotations[I] = Annotations[I];
    211 }
    212 
    213 unsigned CodeCompletionString::getAnnotationCount() const {
    214   return NumAnnotations;
    215 }
    216 
    217 const char *CodeCompletionString::getAnnotation(unsigned AnnotationNr) const {
    218   if (AnnotationNr < NumAnnotations)
    219     return reinterpret_cast<const char * const*>(end())[AnnotationNr];
    220   else
    221     return nullptr;
    222 }
    223 
    224 
    225 std::string CodeCompletionString::getAsString() const {
    226   std::string Result;
    227   llvm::raw_string_ostream OS(Result);
    228 
    229   for (iterator C = begin(), CEnd = end(); C != CEnd; ++C) {
    230     switch (C->Kind) {
    231     case CK_Optional: OS << "{#" << C->Optional->getAsString() << "#}"; break;
    232     case CK_Placeholder: OS << "<#" << C->Text << "#>"; break;
    233 
    234     case CK_Informative:
    235     case CK_ResultType:
    236       OS << "[#" << C->Text << "#]";
    237       break;
    238 
    239     case CK_CurrentParameter: OS << "<#" << C->Text << "#>"; break;
    240     default: OS << C->Text; break;
    241     }
    242   }
    243   return OS.str();
    244 }
    245 
    246 const char *CodeCompletionString::getTypedText() const {
    247   for (iterator C = begin(), CEnd = end(); C != CEnd; ++C)
    248     if (C->Kind == CK_TypedText)
    249       return C->Text;
    250 
    251   return nullptr;
    252 }
    253 
    254 const char *CodeCompletionAllocator::CopyString(const Twine &String) {
    255   SmallString<128> Data;
    256   StringRef Ref = String.toStringRef(Data);
    257   // FIXME: It would be more efficient to teach Twine to tell us its size and
    258   // then add a routine there to fill in an allocated char* with the contents
    259   // of the string.
    260   char *Mem = (char *)Allocate(Ref.size() + 1, 1);
    261   std::copy(Ref.begin(), Ref.end(), Mem);
    262   Mem[Ref.size()] = 0;
    263   return Mem;
    264 }
    265 
    266 StringRef CodeCompletionTUInfo::getParentName(const DeclContext *DC) {
    267   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
    268   if (!ND)
    269     return StringRef();
    270 
    271   // Check whether we've already cached the parent name.
    272   StringRef &CachedParentName = ParentNames[DC];
    273   if (!CachedParentName.empty())
    274     return CachedParentName;
    275 
    276   // If we already processed this DeclContext and assigned empty to it, the
    277   // data pointer will be non-null.
    278   if (CachedParentName.data() != nullptr)
    279     return StringRef();
    280 
    281   // Find the interesting names.
    282   SmallVector<const DeclContext *, 2> Contexts;
    283   while (DC && !DC->isFunctionOrMethod()) {
    284     if (const NamedDecl *ND = dyn_cast<NamedDecl>(DC)) {
    285       if (ND->getIdentifier())
    286         Contexts.push_back(DC);
    287     }
    288 
    289     DC = DC->getParent();
    290   }
    291 
    292   {
    293     SmallString<128> S;
    294     llvm::raw_svector_ostream OS(S);
    295     bool First = true;
    296     for (unsigned I = Contexts.size(); I != 0; --I) {
    297       if (First)
    298         First = false;
    299       else {
    300         OS << "::";
    301       }
    302 
    303       const DeclContext *CurDC = Contexts[I-1];
    304       if (const ObjCCategoryImplDecl *CatImpl = dyn_cast<ObjCCategoryImplDecl>(CurDC))
    305         CurDC = CatImpl->getCategoryDecl();
    306 
    307       if (const ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(CurDC)) {
    308         const ObjCInterfaceDecl *Interface = Cat->getClassInterface();
    309         if (!Interface) {
    310           // Assign an empty StringRef but with non-null data to distinguish
    311           // between empty because we didn't process the DeclContext yet.
    312           CachedParentName = StringRef((const char *)(uintptr_t)~0U, 0);
    313           return StringRef();
    314         }
    315 
    316         OS << Interface->getName() << '(' << Cat->getName() << ')';
    317       } else {
    318         OS << cast<NamedDecl>(CurDC)->getName();
    319       }
    320     }
    321 
    322     CachedParentName = AllocatorRef->CopyString(OS.str());
    323   }
    324 
    325   return CachedParentName;
    326 }
    327 
    328 CodeCompletionString *CodeCompletionBuilder::TakeString() {
    329   void *Mem = getAllocator().Allocate(
    330                   sizeof(CodeCompletionString) + sizeof(Chunk) * Chunks.size()
    331                                     + sizeof(const char *) * Annotations.size(),
    332                                  llvm::alignOf<CodeCompletionString>());
    333   CodeCompletionString *Result
    334     = new (Mem) CodeCompletionString(Chunks.data(), Chunks.size(),
    335                                      Priority, Availability,
    336                                      Annotations.data(), Annotations.size(),
    337                                      ParentName, BriefComment);
    338   Chunks.clear();
    339   return Result;
    340 }
    341 
    342 void CodeCompletionBuilder::AddTypedTextChunk(const char *Text) {
    343   Chunks.push_back(Chunk(CodeCompletionString::CK_TypedText, Text));
    344 }
    345 
    346 void CodeCompletionBuilder::AddTextChunk(const char *Text) {
    347   Chunks.push_back(Chunk::CreateText(Text));
    348 }
    349 
    350 void CodeCompletionBuilder::AddOptionalChunk(CodeCompletionString *Optional) {
    351   Chunks.push_back(Chunk::CreateOptional(Optional));
    352 }
    353 
    354 void CodeCompletionBuilder::AddPlaceholderChunk(const char *Placeholder) {
    355   Chunks.push_back(Chunk::CreatePlaceholder(Placeholder));
    356 }
    357 
    358 void CodeCompletionBuilder::AddInformativeChunk(const char *Text) {
    359   Chunks.push_back(Chunk::CreateInformative(Text));
    360 }
    361 
    362 void CodeCompletionBuilder::AddResultTypeChunk(const char *ResultType) {
    363   Chunks.push_back(Chunk::CreateResultType(ResultType));
    364 }
    365 
    366 void
    367 CodeCompletionBuilder::AddCurrentParameterChunk(const char *CurrentParameter) {
    368   Chunks.push_back(Chunk::CreateCurrentParameter(CurrentParameter));
    369 }
    370 
    371 void CodeCompletionBuilder::AddChunk(CodeCompletionString::ChunkKind CK,
    372                                      const char *Text) {
    373   Chunks.push_back(Chunk(CK, Text));
    374 }
    375 
    376 void CodeCompletionBuilder::addParentContext(const DeclContext *DC) {
    377   if (DC->isTranslationUnit()) {
    378     return;
    379   }
    380 
    381   if (DC->isFunctionOrMethod())
    382     return;
    383 
    384   const NamedDecl *ND = dyn_cast<NamedDecl>(DC);
    385   if (!ND)
    386     return;
    387 
    388   ParentName = getCodeCompletionTUInfo().getParentName(DC);
    389 }
    390 
    391 void CodeCompletionBuilder::addBriefComment(StringRef Comment) {
    392   BriefComment = Allocator.CopyString(Comment);
    393 }
    394 
    395 //===----------------------------------------------------------------------===//
    396 // Code completion overload candidate implementation
    397 //===----------------------------------------------------------------------===//
    398 FunctionDecl *
    399 CodeCompleteConsumer::OverloadCandidate::getFunction() const {
    400   if (getKind() == CK_Function)
    401     return Function;
    402   else if (getKind() == CK_FunctionTemplate)
    403     return FunctionTemplate->getTemplatedDecl();
    404   else
    405     return nullptr;
    406 }
    407 
    408 const FunctionType *
    409 CodeCompleteConsumer::OverloadCandidate::getFunctionType() const {
    410   switch (Kind) {
    411   case CK_Function:
    412     return Function->getType()->getAs<FunctionType>();
    413 
    414   case CK_FunctionTemplate:
    415     return FunctionTemplate->getTemplatedDecl()->getType()
    416              ->getAs<FunctionType>();
    417 
    418   case CK_FunctionType:
    419     return Type;
    420   }
    421 
    422   llvm_unreachable("Invalid CandidateKind!");
    423 }
    424 
    425 //===----------------------------------------------------------------------===//
    426 // Code completion consumer implementation
    427 //===----------------------------------------------------------------------===//
    428 
    429 CodeCompleteConsumer::~CodeCompleteConsumer() { }
    430 
    431 void
    432 PrintingCodeCompleteConsumer::ProcessCodeCompleteResults(Sema &SemaRef,
    433                                                  CodeCompletionContext Context,
    434                                                  CodeCompletionResult *Results,
    435                                                          unsigned NumResults) {
    436   std::stable_sort(Results, Results + NumResults);
    437 
    438   // Print the results.
    439   for (unsigned I = 0; I != NumResults; ++I) {
    440     OS << "COMPLETION: ";
    441     switch (Results[I].Kind) {
    442     case CodeCompletionResult::RK_Declaration:
    443       OS << *Results[I].Declaration;
    444       if (Results[I].Hidden)
    445         OS << " (Hidden)";
    446       if (CodeCompletionString *CCS
    447             = Results[I].CreateCodeCompletionString(SemaRef, Context,
    448                                                     getAllocator(),
    449                                                     CCTUInfo,
    450                                                     includeBriefComments())) {
    451         OS << " : " << CCS->getAsString();
    452         if (const char *BriefComment = CCS->getBriefComment())
    453           OS << " : " << BriefComment;
    454       }
    455 
    456       OS << '\n';
    457       break;
    458 
    459     case CodeCompletionResult::RK_Keyword:
    460       OS << Results[I].Keyword << '\n';
    461       break;
    462 
    463     case CodeCompletionResult::RK_Macro: {
    464       OS << Results[I].Macro->getName();
    465       if (CodeCompletionString *CCS
    466             = Results[I].CreateCodeCompletionString(SemaRef, Context,
    467                                                     getAllocator(),
    468                                                     CCTUInfo,
    469                                                     includeBriefComments())) {
    470         OS << " : " << CCS->getAsString();
    471       }
    472       OS << '\n';
    473       break;
    474     }
    475 
    476     case CodeCompletionResult::RK_Pattern: {
    477       OS << "Pattern : "
    478          << Results[I].Pattern->getAsString() << '\n';
    479       break;
    480     }
    481     }
    482   }
    483 }
    484 
    485 // This function is used solely to preserve the former presentation of overloads
    486 // by "clang -cc1 -code-completion-at", since CodeCompletionString::getAsString
    487 // needs to be improved for printing the newer and more detailed overload
    488 // chunks.
    489 static std::string getOverloadAsString(const CodeCompletionString &CCS) {
    490   std::string Result;
    491   llvm::raw_string_ostream OS(Result);
    492 
    493   for (auto &C : CCS) {
    494     switch (C.Kind) {
    495     case CodeCompletionString::CK_Informative:
    496     case CodeCompletionString::CK_ResultType:
    497       OS << "[#" << C.Text << "#]";
    498       break;
    499 
    500     case CodeCompletionString::CK_CurrentParameter:
    501       OS << "<#" << C.Text << "#>";
    502       break;
    503 
    504     default: OS << C.Text; break;
    505     }
    506   }
    507   return OS.str();
    508 }
    509 
    510 void
    511 PrintingCodeCompleteConsumer::ProcessOverloadCandidates(Sema &SemaRef,
    512                                                         unsigned CurrentArg,
    513                                               OverloadCandidate *Candidates,
    514                                                      unsigned NumCandidates) {
    515   for (unsigned I = 0; I != NumCandidates; ++I) {
    516     if (CodeCompletionString *CCS
    517           = Candidates[I].CreateSignatureString(CurrentArg, SemaRef,
    518                                                 getAllocator(), CCTUInfo,
    519                                                 includeBriefComments())) {
    520       OS << "OVERLOAD: " << getOverloadAsString(*CCS) << "\n";
    521     }
    522   }
    523 }
    524 
    525 /// \brief Retrieve the effective availability of the given declaration.
    526 static AvailabilityResult getDeclAvailability(const Decl *D) {
    527   AvailabilityResult AR = D->getAvailability();
    528   if (isa<EnumConstantDecl>(D))
    529     AR = std::max(AR, cast<Decl>(D->getDeclContext())->getAvailability());
    530   return AR;
    531 }
    532 
    533 void CodeCompletionResult::computeCursorKindAndAvailability(bool Accessible) {
    534   switch (Kind) {
    535   case RK_Pattern:
    536     if (!Declaration) {
    537       // Do nothing: Patterns can come with cursor kinds!
    538       break;
    539     }
    540     // Fall through
    541 
    542   case RK_Declaration: {
    543     // Set the availability based on attributes.
    544     switch (getDeclAvailability(Declaration)) {
    545     case AR_Available:
    546     case AR_NotYetIntroduced:
    547       Availability = CXAvailability_Available;
    548       break;
    549 
    550     case AR_Deprecated:
    551       Availability = CXAvailability_Deprecated;
    552       break;
    553 
    554     case AR_Unavailable:
    555       Availability = CXAvailability_NotAvailable;
    556       break;
    557     }
    558 
    559     if (const FunctionDecl *Function = dyn_cast<FunctionDecl>(Declaration))
    560       if (Function->isDeleted())
    561         Availability = CXAvailability_NotAvailable;
    562 
    563     CursorKind = getCursorKindForDecl(Declaration);
    564     if (CursorKind == CXCursor_UnexposedDecl) {
    565       // FIXME: Forward declarations of Objective-C classes and protocols
    566       // are not directly exposed, but we want code completion to treat them
    567       // like a definition.
    568       if (isa<ObjCInterfaceDecl>(Declaration))
    569         CursorKind = CXCursor_ObjCInterfaceDecl;
    570       else if (isa<ObjCProtocolDecl>(Declaration))
    571         CursorKind = CXCursor_ObjCProtocolDecl;
    572       else
    573         CursorKind = CXCursor_NotImplemented;
    574     }
    575     break;
    576   }
    577 
    578   case RK_Macro:
    579   case RK_Keyword:
    580     llvm_unreachable("Macro and keyword kinds are handled by the constructors");
    581   }
    582 
    583   if (!Accessible)
    584     Availability = CXAvailability_NotAccessible;
    585 }
    586 
    587 /// \brief Retrieve the name that should be used to order a result.
    588 ///
    589 /// If the name needs to be constructed as a string, that string will be
    590 /// saved into Saved and the returned StringRef will refer to it.
    591 static StringRef getOrderedName(const CodeCompletionResult &R,
    592                                     std::string &Saved) {
    593   switch (R.Kind) {
    594     case CodeCompletionResult::RK_Keyword:
    595       return R.Keyword;
    596 
    597     case CodeCompletionResult::RK_Pattern:
    598       return R.Pattern->getTypedText();
    599 
    600     case CodeCompletionResult::RK_Macro:
    601       return R.Macro->getName();
    602 
    603     case CodeCompletionResult::RK_Declaration:
    604       // Handle declarations below.
    605       break;
    606   }
    607 
    608   DeclarationName Name = R.Declaration->getDeclName();
    609 
    610   // If the name is a simple identifier (by far the common case), or a
    611   // zero-argument selector, just return a reference to that identifier.
    612   if (IdentifierInfo *Id = Name.getAsIdentifierInfo())
    613     return Id->getName();
    614   if (Name.isObjCZeroArgSelector())
    615     if (IdentifierInfo *Id
    616         = Name.getObjCSelector().getIdentifierInfoForSlot(0))
    617       return Id->getName();
    618 
    619   Saved = Name.getAsString();
    620   return Saved;
    621 }
    622 
    623 bool clang::operator<(const CodeCompletionResult &X,
    624                       const CodeCompletionResult &Y) {
    625   std::string XSaved, YSaved;
    626   StringRef XStr = getOrderedName(X, XSaved);
    627   StringRef YStr = getOrderedName(Y, YSaved);
    628   int cmp = XStr.compare_lower(YStr);
    629   if (cmp)
    630     return cmp < 0;
    631 
    632   // If case-insensitive comparison fails, try case-sensitive comparison.
    633   cmp = XStr.compare(YStr);
    634   if (cmp)
    635     return cmp < 0;
    636 
    637   return false;
    638 }
    639