clang/lib/AST/ASTImporterLookupTable.cpp

   1 //===- ASTImporterLookupTable.cpp - ASTImporter specific lookup -----------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file defines the ASTImporterLookupTable class which implements a
  10 //  lookup procedure for the import mechanism.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/AST/ASTImporterLookupTable.h"
  15 #include "clang/AST/Decl.h"
  16 #include "clang/AST/RecursiveASTVisitor.h"
  17 #include "llvm/Support/FormatVariadic.h"
  18
  19 namespace clang {
  20
  21 namespace {
  22
  23 struct Builder : RecursiveASTVisitor<Builder> {
  24   ASTImporterLookupTable &LT;
  25   Builder(ASTImporterLookupTable &LT) : LT(LT) {}
  26
  27   bool VisitTypedefNameDecl(TypedefNameDecl *D) {
  28     QualType Ty = D->getUnderlyingType();
  29     Ty = Ty.getCanonicalType();
  30     if (const auto *RTy = dyn_cast<RecordType>(Ty)) {
  31       LT.add(RTy->getAsRecordDecl());
  32       // iterate over the field decls, adding them
  33       for (auto *it : RTy->getAsRecordDecl()->fields()) {
  34         LT.add(it);
  35       }
  36     }
  37     return true;
  38   }
  39
  40   bool VisitNamedDecl(NamedDecl *D) {
  41     LT.add(D);
  42     return true;
  43   }
  44   // In most cases the FriendDecl contains the declaration of the befriended
  45   // class as a child node, so it is discovered during the recursive
  46   // visitation. However, there are cases when the befriended class is not a
  47   // child, thus it must be fetched explicitly from the FriendDecl, and only
  48   // then can we add it to the lookup table.
  49   bool VisitFriendDecl(FriendDecl *D) {
  50     if (D->getFriendType()) {
  51       QualType Ty = D->getFriendType()->getType();
  52       if (isa<ElaboratedType>(Ty))
  53         Ty = cast<ElaboratedType>(Ty)->getNamedType();
  54       // A FriendDecl with a dependent type (e.g. ClassTemplateSpecialization)
  55       // always has that decl as child node.
  56       // However, there are non-dependent cases which does not have the
  57       // type as a child node. We have to dig up that type now.
  58       if (!Ty->isDependentType()) {
  59         if (const auto *RTy = dyn_cast<RecordType>(Ty))
  60           LT.add(RTy->getAsCXXRecordDecl());
  61         else if (const auto *SpecTy = dyn_cast<TemplateSpecializationType>(Ty))
  62           LT.add(SpecTy->getAsCXXRecordDecl());
  63         else if (const auto *SubstTy =
  64                      dyn_cast<SubstTemplateTypeParmType>(Ty)) {
  65           if (SubstTy->getAsCXXRecordDecl())
  66             LT.add(SubstTy->getAsCXXRecordDecl());
  67         } else if (isa<TypedefType>(Ty)) {
  68           // We do not put friend typedefs to the lookup table because
  69           // ASTImporter does not organize typedefs into redecl chains.
  70         } else if (isa<UsingType>(Ty)) {
  71           // Similar to TypedefType, not putting into lookup table.
  72         } else {
  73           llvm_unreachable("Unhandled type of friend class");
  74         }
  75       }
  76     }
  77     return true;
  78   }
  79
  80   // Override default settings of base.
  81   bool shouldVisitTemplateInstantiations() const { return true; }
  82   bool shouldVisitImplicitCode() const { return true; }
  83 };
  84
  85 } // anonymous namespace
  86
  87 ASTImporterLookupTable::ASTImporterLookupTable(TranslationUnitDecl &TU) {
  88   Builder B(*this);
  89   B.TraverseDecl(&TU);
  90 }
  91
  92 void ASTImporterLookupTable::add(DeclContext *DC, NamedDecl *ND) {
  93   DeclList &Decls = LookupTable[DC][ND->getDeclName()];
  94   // Inserts if and only if there is no element in the container equal to it.
  95   Decls.insert(ND);
  96 }
  97
  98 void ASTImporterLookupTable::remove(DeclContext *DC, NamedDecl *ND) {
  99   const DeclarationName Name = ND->getDeclName();
 100   DeclList &Decls = LookupTable[DC][Name];
 101   bool EraseResult = Decls.remove(ND);
 102   (void)EraseResult;
 103 #ifndef NDEBUG
 104   if (!EraseResult) {
 105     std::string Message =
 106         llvm::formatv("Trying to remove not contained Decl '{0}' of type {1}",
 107                       Name.getAsString(), DC->getDeclKindName())
 108             .str();
 109     llvm_unreachable(Message.c_str());
 110   }
 111 #endif
 112 }
 113
 114 void ASTImporterLookupTable::add(NamedDecl *ND) {
 115   assert(ND);
 116   DeclContext *DC = ND->getDeclContext()->getPrimaryContext();
 117   add(DC, ND);
 118   DeclContext *ReDC = DC->getRedeclContext()->getPrimaryContext();
 119   if (DC != ReDC)
 120     add(ReDC, ND);
 121 }
 122
 123 void ASTImporterLookupTable::remove(NamedDecl *ND) {
 124   assert(ND);
 125   DeclContext *DC = ND->getDeclContext()->getPrimaryContext();
 126   remove(DC, ND);
 127   DeclContext *ReDC = DC->getRedeclContext()->getPrimaryContext();
 128   if (DC != ReDC)
 129     remove(ReDC, ND);
 130 }
 131
 132 void ASTImporterLookupTable::update(NamedDecl *ND, DeclContext *OldDC) {
 133   assert(OldDC != ND->getDeclContext() &&
 134          "DeclContext should be changed before update");
 135   if (contains(ND->getDeclContext(), ND)) {
 136     assert(!contains(OldDC, ND) &&
 137            "Decl should not be found in the old context if already in the new");
 138     return;
 139   }
 140
 141   remove(OldDC, ND);
 142   add(ND);
 143 }
 144
 145 void ASTImporterLookupTable::updateForced(NamedDecl *ND, DeclContext *OldDC) {
 146   LookupTable[OldDC][ND->getDeclName()].remove(ND);
 147   add(ND);
 148 }
 149
 150 ASTImporterLookupTable::LookupResult
 151 ASTImporterLookupTable::lookup(DeclContext *DC, DeclarationName Name) const {
 152   auto DCI = LookupTable.find(DC->getPrimaryContext());
 153   if (DCI == LookupTable.end())
 154     return {};
 155
 156   const auto &FoundNameMap = DCI->second;
 157   auto NamesI = FoundNameMap.find(Name);
 158   if (NamesI == FoundNameMap.end())
 159     return {};
 160
 161   return NamesI->second;
 162 }
 163
 164 bool ASTImporterLookupTable::contains(DeclContext *DC, NamedDecl *ND) const {
 165   return lookup(DC, ND->getDeclName()).contains(ND);
 166 }
 167
 168 void ASTImporterLookupTable::dump(DeclContext *DC) const {
 169   auto DCI = LookupTable.find(DC->getPrimaryContext());
 170   if (DCI == LookupTable.end())
 171     llvm::errs() << "empty\n";
 172   const auto &FoundNameMap = DCI->second;
 173   for (const auto &Entry : FoundNameMap) {
 174     DeclarationName Name = Entry.first;
 175     llvm::errs() << "==== Name: ";
 176     Name.dump();
 177     const DeclList& List = Entry.second;
 178     for (NamedDecl *ND : List) {
 179       ND->dump();
 180     }
 181   }
 182 }
 183
 184 void ASTImporterLookupTable::dump() const {
 185   for (const auto &Entry : LookupTable) {
 186     DeclContext *DC = Entry.first;
 187     StringRef Primary = DC->getPrimaryContext() ? " primary" : "";
 188     llvm::errs() << "== DC:" << cast<Decl>(DC) << Primary << "\n";
 189     dump(DC);
 190   }
 191 }
 192
 193 } // namespace clang