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