text: //===--- IndexSymbol.cpp - Types and functions for indexing symbols -------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  
  #include "clang/Index/IndexSymbol.h"
  #include "clang/AST/DeclCXX.h"
  #include "clang/AST/DeclObjC.h"
  #include "clang/AST/DeclTemplate.h"
  #include "clang/AST/PrettyPrinter.h"
  #include "clang/Lex/MacroInfo.h"
  
  using namespace clang;
  using namespace clang::index;
  
  /// \returns true if \c D is a subclass of 'XCTestCase'.
  static bool isUnitTestCase(const ObjCInterfaceDecl *D) {
    if (!D)
      return false;
    while (const ObjCInterfaceDecl *SuperD = D->getSuperClass()) {
      if (SuperD->getName() == "XCTestCase")
        return true;
      D = SuperD;
    }
    return false;
  }
  
  /// \returns true if \c D is in a subclass of 'XCTestCase', returns void, has
  /// no parameters, and its name starts with 'test'.
  static bool isUnitTest(const ObjCMethodDecl *D) {
    if (!D->parameters().empty())
      return false;
    if (!D->getReturnType()->isVoidType())
      return false;
    if (!D->getSelector().getNameForSlot(0).startswith("test"))
      return false;
    return isUnitTestCase(D->getClassInterface());
  }
  
  static void checkForIBOutlets(const Decl *D, SymbolPropertySet &PropSet) {
    if (D->hasAttr<IBOutletAttr>()) {
      PropSet |= (SymbolPropertySet)SymbolProperty::IBAnnotated;
    } else if (D->hasAttr<IBOutletCollectionAttr>()) {
      PropSet |= (SymbolPropertySet)SymbolProperty::IBAnnotated;
      PropSet |= (SymbolPropertySet)SymbolProperty::IBOutletCollection;
    }
  }
  
  bool index::isFunctionLocalSymbol(const Decl *D) {
    assert(D);
  
    if (isa<ParmVarDecl>(D))
      return true;
  
    if (isa<ObjCTypeParamDecl>(D))
      return true;
  
    if (isa<UsingDirectiveDecl>(D))
      return false;
    if (!D->getParentFunctionOrMethod())
      return false;
  
    if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
      switch (ND->getFormalLinkage()) {
        case NoLinkage:
        case InternalLinkage:
          return true;
        case VisibleNoLinkage:
        case UniqueExternalLinkage:
        case ModuleInternalLinkage:
          llvm_unreachable("Not a sema linkage");
        case ModuleLinkage:
        case ExternalLinkage:
          return false;
      }
    }
  
    return true;
  }
  
  SymbolInfo index::getSymbolInfo(const Decl *D) {
    assert(D);
    SymbolInfo Info;
    Info.Kind = SymbolKind::Unknown;
    Info.SubKind = SymbolSubKind::None;
    Info.Properties = SymbolPropertySet();
    Info.Lang = SymbolLanguage::C;
  
    if (isFunctionLocalSymbol(D)) {
      Info.Properties |= (SymbolPropertySet)SymbolProperty::Local;
    }
    if (isa<ObjCProtocolDecl>(D->getDeclContext())) {
      Info.Properties |= (SymbolPropertySet)SymbolProperty::ProtocolInterface;
    }
  
    if (const TagDecl *TD = dyn_cast<TagDecl>(D)) {
      switch (TD->getTagKind()) {
      case TTK_Struct:
        Info.Kind = SymbolKind::Struct; break;
      case TTK_Union:
        Info.Kind = SymbolKind::Union; break;
      case TTK_Class:
        Info.Kind = SymbolKind::Class;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case TTK_Interface:
        Info.Kind = SymbolKind::Protocol;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case TTK_Enum:
        Info.Kind = SymbolKind::Enum; break;
      }
  
      if (const CXXRecordDecl *CXXRec = dyn_cast<CXXRecordDecl>(D)) {
        if (!CXXRec->isCLike()) {
          Info.Lang = SymbolLanguage::CXX;
          if (CXXRec->getDescribedClassTemplate()) {
            Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
          }
        }
      }
  
      if (isa<ClassTemplatePartialSpecializationDecl>(D)) {
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        Info.Properties |=
            (SymbolPropertySet)SymbolProperty::TemplatePartialSpecialization;
      } else if (isa<ClassTemplateSpecializationDecl>(D)) {
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        Info.Properties |=
            (SymbolPropertySet)SymbolProperty::TemplateSpecialization;
      }
  
    } else if (auto *VD = dyn_cast<VarDecl>(D)) {
      Info.Kind = SymbolKind::Variable;
      if (isa<ParmVarDecl>(D)) {
        Info.Kind = SymbolKind::Parameter;
      } else if (isa<CXXRecordDecl>(D->getDeclContext())) {
        Info.Kind = SymbolKind::StaticProperty;
        Info.Lang = SymbolLanguage::CXX;
      }
  
      if (isa<VarTemplatePartialSpecializationDecl>(D)) {
        Info.Lang = SymbolLanguage::CXX;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        Info.Properties |=
            (SymbolPropertySet)SymbolProperty::TemplatePartialSpecialization;
      } else if (isa<VarTemplateSpecializationDecl>(D)) {
        Info.Lang = SymbolLanguage::CXX;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        Info.Properties |=
            (SymbolPropertySet)SymbolProperty::TemplateSpecialization;
      } else if (VD->getDescribedVarTemplate()) {
        Info.Lang = SymbolLanguage::CXX;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
      }
  
    } else {
      switch (D->getKind()) {
      case Decl::Import:
        Info.Kind = SymbolKind::Module;
        break;
      case Decl::Typedef:
        Info.Kind = SymbolKind::TypeAlias; break; // Lang = C
      case Decl::Function:
        Info.Kind = SymbolKind::Function;
        break;
      case Decl::Field:
        Info.Kind = SymbolKind::Field;
        if (const CXXRecordDecl *
              CXXRec = dyn_cast<CXXRecordDecl>(D->getDeclContext())) {
          if (!CXXRec->isCLike())
            Info.Lang = SymbolLanguage::CXX;
        }
        break;
      case Decl::EnumConstant:
        Info.Kind = SymbolKind::EnumConstant; break;
      case Decl::ObjCInterface:
      case Decl::ObjCImplementation: {
        Info.Kind = SymbolKind::Class;
        Info.Lang = SymbolLanguage::ObjC;
        const ObjCInterfaceDecl *ClsD = dyn_cast<ObjCInterfaceDecl>(D);
        if (!ClsD)
          ClsD = cast<ObjCImplementationDecl>(D)->getClassInterface();
        if (isUnitTestCase(ClsD))
          Info.Properties |= (SymbolPropertySet)SymbolProperty::UnitTest;
        break;
      }
      case Decl::ObjCProtocol:
        Info.Kind = SymbolKind::Protocol;
        Info.Lang = SymbolLanguage::ObjC;
        break;
      case Decl::ObjCCategory:
      case Decl::ObjCCategoryImpl: {
        Info.Kind = SymbolKind::Extension;
        Info.Lang = SymbolLanguage::ObjC;
        const ObjCInterfaceDecl *ClsD = nullptr;
        if (auto *CatD = dyn_cast<ObjCCategoryDecl>(D))
          ClsD = CatD->getClassInterface();
        else
          ClsD = cast<ObjCCategoryImplDecl>(D)->getClassInterface();
        if (isUnitTestCase(ClsD))
          Info.Properties |= (SymbolPropertySet)SymbolProperty::UnitTest;
        break;
      }
      case Decl::ObjCMethod: {
        const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(D);
        Info.Kind = MD->isInstanceMethod() ? SymbolKind::InstanceMethod : SymbolKind::ClassMethod;
        if (MD->isPropertyAccessor()) {
          if (MD->param_size())
            Info.SubKind = SymbolSubKind::AccessorSetter;
          else
            Info.SubKind = SymbolSubKind::AccessorGetter;
        }
        Info.Lang = SymbolLanguage::ObjC;
        if (isUnitTest(MD))
          Info.Properties |= (SymbolPropertySet)SymbolProperty::UnitTest;
        if (D->hasAttr<IBActionAttr>())
          Info.Properties |= (SymbolPropertySet)SymbolProperty::IBAnnotated;
        break;
      }
      case Decl::ObjCProperty:
        Info.Kind = SymbolKind::InstanceProperty;
        Info.Lang = SymbolLanguage::ObjC;
        checkForIBOutlets(D, Info.Properties);
        if (auto *Annot = D->getAttr<AnnotateAttr>()) {
          if (Annot->getAnnotation() == "gk_inspectable")
            Info.Properties |= (SymbolPropertySet)SymbolProperty::GKInspectable;
        }
        break;
      case Decl::ObjCIvar:
        Info.Kind = SymbolKind::Field;
        Info.Lang = SymbolLanguage::ObjC;
        checkForIBOutlets(D, Info.Properties);
        break;
      case Decl::Namespace:
        Info.Kind = SymbolKind::Namespace;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case Decl::NamespaceAlias:
        Info.Kind = SymbolKind::NamespaceAlias;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case Decl::CXXConstructor: {
        Info.Kind = SymbolKind::Constructor;
        Info.Lang = SymbolLanguage::CXX;
        auto *CD = cast<CXXConstructorDecl>(D);
        if (CD->isCopyConstructor())
          Info.SubKind = SymbolSubKind::CXXCopyConstructor;
        else if (CD->isMoveConstructor())
          Info.SubKind = SymbolSubKind::CXXMoveConstructor;
        break;
      }
      case Decl::CXXDestructor:
        Info.Kind = SymbolKind::Destructor;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case Decl::CXXConversion:
        Info.Kind = SymbolKind::ConversionFunction;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case Decl::CXXMethod: {
        const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
        if (MD->isStatic())
          Info.Kind = SymbolKind::StaticMethod;
        else
          Info.Kind = SymbolKind::InstanceMethod;
        Info.Lang = SymbolLanguage::CXX;
        break;
      }
      case Decl::ClassTemplate:
        Info.Kind = SymbolKind::Class;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case Decl::FunctionTemplate:
        Info.Kind = SymbolKind::Function;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        Info.Lang = SymbolLanguage::CXX;
        if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(
                             cast<FunctionTemplateDecl>(D)->getTemplatedDecl())) {
          if (isa<CXXConstructorDecl>(MD))
            Info.Kind = SymbolKind::Constructor;
          else if (isa<CXXDestructorDecl>(MD))
            Info.Kind = SymbolKind::Destructor;
          else if (isa<CXXConversionDecl>(MD))
            Info.Kind = SymbolKind::ConversionFunction;
          else {
            if (MD->isStatic())
              Info.Kind = SymbolKind::StaticMethod;
            else
              Info.Kind = SymbolKind::InstanceMethod;
          }
        }
        break;
      case Decl::TypeAliasTemplate:
        Info.Kind = SymbolKind::TypeAlias;
        Info.Lang = SymbolLanguage::CXX;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        break;
      case Decl::TypeAlias:
        Info.Kind = SymbolKind::TypeAlias;
        Info.Lang = SymbolLanguage::CXX;
        break;
      case Decl::UnresolvedUsingTypename:
        Info.Kind = SymbolKind::Using;
        Info.SubKind = SymbolSubKind::UsingTypename;
        Info.Lang = SymbolLanguage::CXX;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        break;
      case Decl::UnresolvedUsingValue:
        Info.Kind = SymbolKind::Using;
        Info.SubKind = SymbolSubKind::UsingValue;
        Info.Lang = SymbolLanguage::CXX;
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        break;
      case Decl::Binding:
        Info.Kind = SymbolKind::Variable;
        Info.Lang = SymbolLanguage::CXX;
        break;
      default:
        break;
      }
    }
  
    if (Info.Kind == SymbolKind::Unknown)
      return Info;
  
    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
      if (FD->getTemplatedKind() ==
            FunctionDecl::TK_FunctionTemplateSpecialization) {
        Info.Properties |= (SymbolPropertySet)SymbolProperty::Generic;
        Info.Properties |=
            (SymbolPropertySet)SymbolProperty::TemplateSpecialization;
      }
    }
  
    if (Info.Properties & (SymbolPropertySet)SymbolProperty::Generic)
      Info.Lang = SymbolLanguage::CXX;
  
    if (auto *attr = D->getExternalSourceSymbolAttr()) {
      if (attr->getLanguage() == "Swift")
        Info.Lang = SymbolLanguage::Swift;
    }
  
    return Info;
  }
  
  SymbolInfo index::getSymbolInfoForMacro(const MacroInfo &) {
    SymbolInfo Info;
    Info.Kind = SymbolKind::Macro;
    Info.SubKind = SymbolSubKind::None;
    Info.Properties = SymbolPropertySet();
    Info.Lang = SymbolLanguage::C;
    return Info;
  }
  
  bool index::applyForEachSymbolRoleInterruptible(SymbolRoleSet Roles,
                                     llvm::function_ref<bool(SymbolRole)> Fn) {
  #define APPLY_FOR_ROLE(Role) \
    if (Roles & (unsigned)SymbolRole::Role) \
      if (!Fn(SymbolRole::Role)) \
        return false;
  
    APPLY_FOR_ROLE(Declaration);
    APPLY_FOR_ROLE(Definition);
    APPLY_FOR_ROLE(Reference);
    APPLY_FOR_ROLE(Read);
    APPLY_FOR_ROLE(Write);
    APPLY_FOR_ROLE(Call);
    APPLY_FOR_ROLE(Dynamic);
    APPLY_FOR_ROLE(AddressOf);
    APPLY_FOR_ROLE(Implicit);
    APPLY_FOR_ROLE(Undefinition);
    APPLY_FOR_ROLE(RelationChildOf);
    APPLY_FOR_ROLE(RelationBaseOf);
    APPLY_FOR_ROLE(RelationOverrideOf);
    APPLY_FOR_ROLE(RelationReceivedBy);
    APPLY_FOR_ROLE(RelationCalledBy);
    APPLY_FOR_ROLE(RelationExtendedBy);
    APPLY_FOR_ROLE(RelationAccessorOf);
    APPLY_FOR_ROLE(RelationContainedBy);
    APPLY_FOR_ROLE(RelationIBTypeOf);
    APPLY_FOR_ROLE(RelationSpecializationOf);
  
  #undef APPLY_FOR_ROLE
  
    return true;
  }
  
  void index::applyForEachSymbolRole(SymbolRoleSet Roles,
                                     llvm::function_ref<void(SymbolRole)> Fn) {
    applyForEachSymbolRoleInterruptible(Roles, [&](SymbolRole r) -> bool {
      Fn(r);
      return true;
    });
  }
  
  void index::printSymbolRoles(SymbolRoleSet Roles, raw_ostream &OS) {
    bool VisitedOnce = false;
    applyForEachSymbolRole(Roles, [&](SymbolRole Role) {
      if (VisitedOnce)
        OS << ',';
      else
        VisitedOnce = true;
      switch (Role) {
      case SymbolRole::Declaration: OS << "Decl"; break;
      case SymbolRole::Definition: OS << "Def"; break;
      case SymbolRole::Reference: OS << "Ref"; break;
      case SymbolRole::Read: OS << "Read"; break;
      case SymbolRole::Write: OS << "Writ"; break;
      case SymbolRole::Call: OS << "Call"; break;
      case SymbolRole::Dynamic: OS << "Dyn"; break;
      case SymbolRole::AddressOf: OS << "Addr"; break;
      case SymbolRole::Implicit: OS << "Impl"; break;
      case SymbolRole::Undefinition: OS << "Undef"; break;
      case SymbolRole::RelationChildOf: OS << "RelChild"; break;
      case SymbolRole::RelationBaseOf: OS << "RelBase"; break;
      case SymbolRole::RelationOverrideOf: OS << "RelOver"; break;
      case SymbolRole::RelationReceivedBy: OS << "RelRec"; break;
      case SymbolRole::RelationCalledBy: OS << "RelCall"; break;
      case SymbolRole::RelationExtendedBy: OS << "RelExt"; break;
      case SymbolRole::RelationAccessorOf: OS << "RelAcc"; break;
      case SymbolRole::RelationContainedBy: OS << "RelCont"; break;
      case SymbolRole::RelationIBTypeOf: OS << "RelIBType"; break;
      case SymbolRole::RelationSpecializationOf: OS << "RelSpecialization"; break;
      }
    });
  }
  
  bool index::printSymbolName(const Decl *D, const LangOptions &LO,
                              raw_ostream &OS) {
    if (auto *ND = dyn_cast<NamedDecl>(D)) {
      PrintingPolicy Policy(LO);
      // Forward references can have different template argument names. Suppress
      // the template argument names in constructors to make their name more
      // stable.
      Policy.SuppressTemplateArgsInCXXConstructors = true;
      DeclarationName DeclName = ND->getDeclName();
      if (DeclName.isEmpty())
        return true;
      DeclName.print(OS, Policy);
      return false;
    } else {
      return true;
    }
  }
  
  StringRef index::getSymbolKindString(SymbolKind K) {
    switch (K) {
    case SymbolKind::Unknown: return "<unknown>";
    case SymbolKind::Module: return "module";
    case SymbolKind::Namespace: return "namespace";
    case SymbolKind::NamespaceAlias: return "namespace-alias";
    case SymbolKind::Macro: return "macro";
    case SymbolKind::Enum: return "enum";
    case SymbolKind::Struct: return "struct";
    case SymbolKind::Class: return "class";
    case SymbolKind::Protocol: return "protocol";
    case SymbolKind::Extension: return "extension";
    case SymbolKind::Union: return "union";
    case SymbolKind::TypeAlias: return "type-alias";
    case SymbolKind::Function: return "function";
    case SymbolKind::Variable: return "variable";
    case SymbolKind::Field: return "field";
    case SymbolKind::EnumConstant: return "enumerator";
    case SymbolKind::InstanceMethod: return "instance-method";
    case SymbolKind::ClassMethod: return "class-method";
    case SymbolKind::StaticMethod: return "static-method";
    case SymbolKind::InstanceProperty: return "instance-property";
    case SymbolKind::ClassProperty: return "class-property";
    case SymbolKind::StaticProperty: return "static-property";
    case SymbolKind::Constructor: return "constructor";
    case SymbolKind::Destructor: return "destructor";
    case SymbolKind::ConversionFunction: return "coversion-func";
    case SymbolKind::Parameter: return "param";
    case SymbolKind::Using: return "using";
    }
    llvm_unreachable("invalid symbol kind");
  }
  
  StringRef index::getSymbolSubKindString(SymbolSubKind K) {
    switch (K) {
    case SymbolSubKind::None: return "<none>";
    case SymbolSubKind::CXXCopyConstructor: return "cxx-copy-ctor";
    case SymbolSubKind::CXXMoveConstructor: return "cxx-move-ctor";
    case SymbolSubKind::AccessorGetter: return "acc-get";
    case SymbolSubKind::AccessorSetter: return "acc-set";
    case SymbolSubKind::UsingTypename: return "using-typename";
    case SymbolSubKind::UsingValue: return "using-value";
    }
    llvm_unreachable("invalid symbol subkind");
  }
  
  StringRef index::getSymbolLanguageString(SymbolLanguage K) {
    switch (K) {
    case SymbolLanguage::C: return "C";
    case SymbolLanguage::ObjC: return "ObjC";
    case SymbolLanguage::CXX: return "C++";
    case SymbolLanguage::Swift: return "Swift";
    }
    llvm_unreachable("invalid symbol language kind");
  }
  
  void index::applyForEachSymbolProperty(SymbolPropertySet Props,
                                    llvm::function_ref<void(SymbolProperty)> Fn) {
  #define APPLY_FOR_PROPERTY(K)                                                  \
    if (Props & (SymbolPropertySet)SymbolProperty::K)                            \
    Fn(SymbolProperty::K)
  
    APPLY_FOR_PROPERTY(Generic);
    APPLY_FOR_PROPERTY(TemplatePartialSpecialization);
    APPLY_FOR_PROPERTY(TemplateSpecialization);
    APPLY_FOR_PROPERTY(UnitTest);
    APPLY_FOR_PROPERTY(IBAnnotated);
    APPLY_FOR_PROPERTY(IBOutletCollection);
    APPLY_FOR_PROPERTY(GKInspectable);
    APPLY_FOR_PROPERTY(Local);
    APPLY_FOR_PROPERTY(ProtocolInterface);
  
  #undef APPLY_FOR_PROPERTY
  }
  
  void index::printSymbolProperties(SymbolPropertySet Props, raw_ostream &OS) {
    bool VisitedOnce = false;
    applyForEachSymbolProperty(Props, [&](SymbolProperty Prop) {
      if (VisitedOnce)
        OS << ',';
      else
        VisitedOnce = true;
      switch (Prop) {
      case SymbolProperty::Generic: OS << "Gen"; break;
      case SymbolProperty::TemplatePartialSpecialization: OS << "TPS"; break;
      case SymbolProperty::TemplateSpecialization: OS << "TS"; break;
      case SymbolProperty::UnitTest: OS << "test"; break;
      case SymbolProperty::IBAnnotated: OS << "IB"; break;
      case SymbolProperty::IBOutletCollection: OS << "IBColl"; break;
      case SymbolProperty::GKInspectable: OS << "GKI"; break;
      case SymbolProperty::Local: OS << "local"; break;
      case SymbolProperty::ProtocolInterface: OS << "protocol"; break;
      }
    });
  }
  