[libclang] Separate the underlying indexing functionality of libclang and introduce it into the clangIndex library.

It is a general goodness for libclang itself to mostly be a wrapper of functionality provided by the libraries.

llvm-svn: 260760

8 files changed, 1759 insertions, 0 deletions

diff --git a/clang/lib/Index/CMakeLists.txt b/clang/lib/Index/CMakeLists.txt
index 3869c32c879..cb2b931235e 100644
--- a/clang/lib/Index/CMakeLists.txt
+++ b/clang/lib/Index/CMakeLists.txt
@@ -5,14 +5,22 @@ set(LLVM_LINK_COMPONENTS
 add_clang_library(clangIndex
   CommentToXML.cpp
   USRGeneration.cpp
+  IndexBody.cpp
+  IndexDecl.cpp
+  IndexingAction.cpp
+  IndexingContext.cpp
+  IndexSymbol.cpp
+  IndexTypeSourceInfo.cpp
 
   ADDITIONAL_HEADERS
+  IndexingContext.h
   SimpleFormatContext.h
 
   LINK_LIBS
   clangAST
   clangBasic
   clangFormat
+  clangFrontend
   clangRewrite
   clangToolingCore
   )
diff --git a/clang/lib/Index/IndexBody.cpp b/clang/lib/Index/IndexBody.cpp
new file mode 100644
index 00000000000..56fba28387d
--- /dev/null
+++ b/clang/lib/Index/IndexBody.cpp
@@ -0,0 +1,347 @@
+//===- IndexBody.cpp - Indexing statements --------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IndexingContext.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+
+using namespace clang;
+using namespace clang::index;
+
+namespace {
+
+class BodyIndexer : public RecursiveASTVisitor<BodyIndexer> {
+  IndexingContext &IndexCtx;
+  const NamedDecl *Parent;
+  const DeclContext *ParentDC;
+  SmallVector<Stmt*, 16> StmtStack;
+
+  typedef RecursiveASTVisitor<BodyIndexer> base;
+public:
+  BodyIndexer(IndexingContext &indexCtx,
+              const NamedDecl *Parent, const DeclContext *DC)
+    : IndexCtx(indexCtx), Parent(Parent), ParentDC(DC) { }
+  
+  bool shouldWalkTypesOfTypeLocs() const { return false; }
+
+  bool TraverseStmt(Stmt *S) {
+    StmtStack.push_back(S);
+    bool ret = base::TraverseStmt(S);
+    StmtStack.pop_back();
+    return ret;
+  }
+
+  bool TraverseTypeLoc(TypeLoc TL) {
+    IndexCtx.indexTypeLoc(TL, Parent, ParentDC);
+    return true;
+  }
+
+  bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
+    IndexCtx.indexNestedNameSpecifierLoc(NNS, Parent, ParentDC);
+    return true;
+  }
+
+  SymbolRoleSet getRolesForRef(const Expr *E,
+                               SmallVectorImpl<SymbolRelation> &Relations) {
+    SymbolRoleSet Roles{};
+    assert(!StmtStack.empty() && E == StmtStack.back());
+    if (StmtStack.size() == 1)
+      return Roles;
+    auto It = StmtStack.end()-2;
+    while (isa<CastExpr>(*It) || isa<ParenExpr>(*It)) {
+      if (auto ICE = dyn_cast<ImplicitCastExpr>(*It)) {
+        if (ICE->getCastKind() == CK_LValueToRValue)
+          Roles |= (unsigned)(unsigned)SymbolRole::Read;
+      }
+      if (It == StmtStack.begin())
+        break;
+      --It;
+    }
+    const Stmt *Parent = *It;
+
+    if (auto BO = dyn_cast<BinaryOperator>(Parent)) {
+      if (BO->getOpcode() == BO_Assign && BO->getLHS()->IgnoreParenCasts() == E)
+        Roles |= (unsigned)SymbolRole::Write;
+
+    } else if (auto UO = dyn_cast<UnaryOperator>(Parent)) {
+      if (UO->isIncrementDecrementOp()) {
+        Roles |= (unsigned)SymbolRole::Read;
+        Roles |= (unsigned)SymbolRole::Write;
+      } else if (UO->getOpcode() == UO_AddrOf) {
+        Roles |= (unsigned)SymbolRole::AddressOf;
+      }
+
+    } else if (auto CA = dyn_cast<CompoundAssignOperator>(Parent)) {
+      if (CA->getLHS()->IgnoreParenCasts() == E) {
+        Roles |= (unsigned)SymbolRole::Read;
+        Roles |= (unsigned)SymbolRole::Write;
+      }
+
+    } else if (auto CE = dyn_cast<CallExpr>(Parent)) {
+      if (CE->getCallee()->IgnoreParenCasts() == E) {
+        Roles |= (unsigned)SymbolRole::Call;
+        if (auto *ME = dyn_cast<MemberExpr>(E)) {
+          if (auto *CXXMD = dyn_cast_or_null<CXXMethodDecl>(ME->getMemberDecl()))
+            if (CXXMD->isVirtual() && !ME->hasQualifier()) {
+              Roles |= (unsigned)SymbolRole::Dynamic;
+              auto BaseTy = ME->getBase()->IgnoreImpCasts()->getType();
+              if (!BaseTy.isNull())
+                if (auto *CXXRD = BaseTy->getPointeeCXXRecordDecl())
+                  Relations.emplace_back((unsigned)SymbolRole::RelationReceivedBy,
+                                         CXXRD);
+            }
+        }
+      } else if (auto CXXOp = dyn_cast<CXXOperatorCallExpr>(CE)) {
+        if (CXXOp->getNumArgs() > 0 && CXXOp->getArg(0)->IgnoreParenCasts() == E) {
+          OverloadedOperatorKind Op = CXXOp->getOperator();
+          if (Op == OO_Equal) {
+            Roles |= (unsigned)SymbolRole::Write;
+          } else if ((Op >= OO_PlusEqual && Op <= OO_PipeEqual) ||
+                     Op == OO_LessLessEqual || Op == OO_GreaterGreaterEqual ||
+                     Op == OO_PlusPlus || Op == OO_MinusMinus) {
+            Roles |= (unsigned)SymbolRole::Read;
+            Roles |= (unsigned)SymbolRole::Write;
+          } else if (Op == OO_Amp) {
+            Roles |= (unsigned)SymbolRole::AddressOf;
+          }
+        }
+      }
+    }
+
+    return Roles;
+  }
+
+  bool VisitDeclRefExpr(DeclRefExpr *E) {
+    SmallVector<SymbolRelation, 4> Relations;
+    SymbolRoleSet Roles = getRolesForRef(E, Relations);
+    return IndexCtx.handleReference(E->getDecl(), E->getLocation(),
+                                    Parent, ParentDC, Roles, Relations, E);
+  }
+
+  bool VisitMemberExpr(MemberExpr *E) {
+    SourceLocation Loc = E->getMemberLoc();
+    if (Loc.isInvalid())
+      Loc = E->getLocStart();
+    SmallVector<SymbolRelation, 4> Relations;
+    SymbolRoleSet Roles = getRolesForRef(E, Relations);
+    return IndexCtx.handleReference(E->getMemberDecl(), Loc,
+                                    Parent, ParentDC, Roles, Relations, E);
+  }
+
+  bool VisitDesignatedInitExpr(DesignatedInitExpr *E) {
+    for (DesignatedInitExpr::reverse_designators_iterator
+           D = E->designators_rbegin(), DEnd = E->designators_rend();
+           D != DEnd; ++D) {
+      if (D->isFieldDesignator())
+        return IndexCtx.handleReference(D->getField(), D->getFieldLoc(),
+                                        Parent, ParentDC, SymbolRoleSet(),
+                                        {}, E);
+    }
+    return true;
+  }
+
+  bool VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) {
+    SmallVector<SymbolRelation, 4> Relations;
+    SymbolRoleSet Roles = getRolesForRef(E, Relations);
+    return IndexCtx.handleReference(E->getDecl(), E->getLocation(),
+                                    Parent, ParentDC, Roles, Relations, E);
+  }
+
+  bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
+    auto isDynamic = [](const ObjCMessageExpr *MsgE)->bool {
+      if (MsgE->getReceiverKind() != ObjCMessageExpr::Instance)
+        return false;
+      if (auto *RecE = dyn_cast<ObjCMessageExpr>(
+              MsgE->getInstanceReceiver()->IgnoreParenCasts())) {
+        if (RecE->getMethodFamily() == OMF_alloc)
+          return false;
+      }
+      return true;
+    };
+
+    if (ObjCMethodDecl *MD = E->getMethodDecl()) {
+      SymbolRoleSet Roles = (unsigned)SymbolRole::Call;
+      if (E->isImplicit())
+        Roles |= (unsigned)SymbolRole::Implicit;
+
+      SmallVector<SymbolRelation, 2> Relations;
+      if (isDynamic(E)) {
+        Roles |= (unsigned)SymbolRole::Dynamic;
+        if (auto *RecD = E->getReceiverInterface())
+          Relations.emplace_back((unsigned)SymbolRole::RelationReceivedBy, RecD);
+      }
+
+      return IndexCtx.handleReference(MD, E->getSelectorStartLoc(),
+                                      Parent, ParentDC, Roles, Relations, E);
+    }
+    return true;
+  }
+
+  bool VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) {
+    if (E->isExplicitProperty())
+      return IndexCtx.handleReference(E->getExplicitProperty(), E->getLocation(),
+                                      Parent, ParentDC, SymbolRoleSet(), {}, E);
+
+    // No need to do a handleReference for the objc method, because there will
+    // be a message expr as part of PseudoObjectExpr.
+    return true;
+  }
+
+  bool VisitMSPropertyRefExpr(MSPropertyRefExpr *E) {
+    return IndexCtx.handleReference(E->getPropertyDecl(), E->getMemberLoc(),
+                                    Parent, ParentDC, SymbolRoleSet(), {}, E);
+  }
+
+  bool VisitObjCProtocolExpr(ObjCProtocolExpr *E) {
+    return IndexCtx.handleReference(E->getProtocol(), E->getProtocolIdLoc(),
+                                    Parent, ParentDC, SymbolRoleSet(), {}, E);
+  }
+
+  bool VisitObjCBoxedExpr(ObjCBoxedExpr *E) {
+    if (ObjCMethodDecl *MD = E->getBoxingMethod()) {
+      SymbolRoleSet Roles = (unsigned)SymbolRole::Call;
+      Roles |= (unsigned)SymbolRole::Implicit;
+      return IndexCtx.handleReference(MD, E->getLocStart(),
+                                      Parent, ParentDC, Roles, {}, E);
+    }
+    return true;
+  }
+  
+  bool VisitObjCDictionaryLiteral(ObjCDictionaryLiteral *E) {
+    if (ObjCMethodDecl *MD = E->getDictWithObjectsMethod()) {
+      SymbolRoleSet Roles = (unsigned)SymbolRole::Call;
+      Roles |= (unsigned)SymbolRole::Implicit;
+      return IndexCtx.handleReference(MD, E->getLocStart(),
+                                      Parent, ParentDC, Roles, {}, E);
+    }
+    return true;
+  }
+
+  bool VisitObjCArrayLiteral(ObjCArrayLiteral *E) {
+    if (ObjCMethodDecl *MD = E->getArrayWithObjectsMethod()) {
+      SymbolRoleSet Roles = (unsigned)SymbolRole::Call;
+      Roles |= (unsigned)SymbolRole::Implicit;
+      return IndexCtx.handleReference(MD, E->getLocStart(),
+                                      Parent, ParentDC, Roles, {}, E);
+    }
+    return true;
+  }
+
+  bool VisitCXXConstructExpr(CXXConstructExpr *E) {
+    return IndexCtx.handleReference(E->getConstructor(), E->getLocation(),
+                                    Parent, ParentDC, (unsigned)SymbolRole::Call, {}, E);
+  }
+
+  bool TraverseCXXOperatorCallExpr(CXXOperatorCallExpr *E,
+                                   DataRecursionQueue *Q = nullptr) {
+    if (E->getOperatorLoc().isInvalid())
+      return true; // implicit.
+    return base::TraverseCXXOperatorCallExpr(E);
+  }
+
+  bool VisitDeclStmt(DeclStmt *S) {
+    if (IndexCtx.shouldIndexFunctionLocalSymbols()) {
+      IndexCtx.indexDeclGroupRef(S->getDeclGroup());
+      return true;
+    }
+
+    DeclGroupRef DG = S->getDeclGroup();
+    for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I) {
+      const Decl *D = *I;
+      if (!D)
+        continue;
+      if (!IndexCtx.isFunctionLocalDecl(D))
+        IndexCtx.indexTopLevelDecl(D);
+    }
+
+    return true;
+  }
+
+  bool TraverseLambdaCapture(LambdaExpr *LE, const LambdaCapture *C) {
+    if (C->capturesThis() || C->capturesVLAType())
+      return true;
+
+    if (C->capturesVariable() && IndexCtx.shouldIndexFunctionLocalSymbols())
+      return IndexCtx.handleReference(C->getCapturedVar(), C->getLocation(),
+                                      Parent, ParentDC, SymbolRoleSet());
+
+    // FIXME: Lambda init-captures.
+    return true;
+  }
+
+  // RecursiveASTVisitor visits both syntactic and semantic forms, duplicating
+  // the things that we visit. Make sure to only visit the semantic form.
+  // Also visit things that are in the syntactic form but not the semantic one,
+  // for example the indices in DesignatedInitExprs.
+  bool TraverseInitListExpr(InitListExpr *S, DataRecursionQueue *Q = nullptr) {
+
+    class SyntacticFormIndexer :
+              public RecursiveASTVisitor<SyntacticFormIndexer> {
+      IndexingContext &IndexCtx;
+      const NamedDecl *Parent;
+      const DeclContext *ParentDC;
+
+    public:
+      SyntacticFormIndexer(IndexingContext &indexCtx,
+                            const NamedDecl *Parent, const DeclContext *DC)
+        : IndexCtx(indexCtx), Parent(Parent), ParentDC(DC) { }
+
+      bool shouldWalkTypesOfTypeLocs() const { return false; }
+
+      bool VisitDesignatedInitExpr(DesignatedInitExpr *E) {
+        for (DesignatedInitExpr::reverse_designators_iterator
+               D = E->designators_rbegin(), DEnd = E->designators_rend();
+               D != DEnd; ++D) {
+          if (D->isFieldDesignator())
+            return IndexCtx.handleReference(D->getField(), D->getFieldLoc(),
+                                            Parent, ParentDC, SymbolRoleSet(),
+                                            {}, E);
+        }
+        return true;
+      }
+    };
+
+    auto visitForm = [&](InitListExpr *Form) {
+      for (Stmt *SubStmt : Form->children()) {
+        if (!TraverseStmt(SubStmt))
+          return false;
+      }
+      return true;
+    };
+
+    InitListExpr *SemaForm = S->isSemanticForm() ? S : S->getSemanticForm();
+    InitListExpr *SyntaxForm = S->isSemanticForm() ? S->getSyntacticForm() : S;
+
+    if (SemaForm) {
+      // Visit things present in syntactic form but not the semantic form.
+      if (SyntaxForm) {
+        SyntacticFormIndexer(IndexCtx, Parent, ParentDC).TraverseStmt(SyntaxForm);
+      }
+      return visitForm(SemaForm);
+    }
+
+    // No semantic, try the syntactic.
+    if (SyntaxForm) {
+      return visitForm(SyntaxForm);
+    }
+
+    return true;
+  }
+};
+
+} // anonymous namespace
+
+void IndexingContext::indexBody(const Stmt *S, const NamedDecl *Parent,
+                                const DeclContext *DC) {
+  if (!S)
+    return;
+
+  if (!DC)
+    DC = Parent->getLexicalDeclContext();
+  BodyIndexer(*this, Parent, DC).TraverseStmt(const_cast<Stmt*>(S));
+}
diff --git a/clang/lib/Index/IndexDecl.cpp b/clang/lib/Index/IndexDecl.cpp
new file mode 100644
index 00000000000..76f68e564c9
--- /dev/null
+++ b/clang/lib/Index/IndexDecl.cpp
@@ -0,0 +1,429 @@
+//===- IndexDecl.cpp - Indexing declarations ------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IndexingContext.h"
+#include "clang/Index/IndexDataConsumer.h"
+#include "clang/AST/DeclVisitor.h"
+
+using namespace clang;
+using namespace index;
+
+namespace {
+
+class IndexingDeclVisitor : public ConstDeclVisitor<IndexingDeclVisitor, bool> {
+  IndexingContext &IndexCtx;
+
+public:
+  explicit IndexingDeclVisitor(IndexingContext &indexCtx)
+    : IndexCtx(indexCtx) { }
+
+  bool Handled = true;
+
+  bool VisitDecl(const Decl *D) {
+    Handled = false;
+    return true;
+  }
+
+  /// \brief Returns true if the given method has been defined explicitly by the
+  /// user.
+  static bool hasUserDefined(const ObjCMethodDecl *D,
+                             const ObjCImplDecl *Container) {
+    const ObjCMethodDecl *MD = Container->getMethod(D->getSelector(),
+                                                    D->isInstanceMethod());
+    return MD && !MD->isImplicit() && MD->isThisDeclarationADefinition();
+  }
+
+  void handleDeclarator(const DeclaratorDecl *D,
+                        const NamedDecl *Parent = nullptr) {
+    if (!Parent) Parent = D;
+
+    IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), Parent);
+    IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent);
+    if (IndexCtx.shouldIndexFunctionLocalSymbols()) {
+      // Only index parameters in definitions, parameters in declarations are
+      // not useful.
+      if (const ParmVarDecl *Parm = dyn_cast<ParmVarDecl>(D)) {
+        auto *DC = Parm->getDeclContext();
+        if (auto *FD = dyn_cast<FunctionDecl>(DC)) {
+          if (FD->isThisDeclarationADefinition())
+            IndexCtx.handleDecl(Parm);
+        } else if (auto *MD = dyn_cast<ObjCMethodDecl>(DC)) {
+          if (MD->isThisDeclarationADefinition())
+            IndexCtx.handleDecl(Parm);
+        } else {
+          IndexCtx.handleDecl(Parm);
+        }
+      } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+        if (FD->isThisDeclarationADefinition()) {
+          for (auto PI : FD->params()) {
+            IndexCtx.handleDecl(PI);
+          }
+        }
+      }
+    }
+  }
+
+  bool handleObjCMethod(const ObjCMethodDecl *D) {
+    if (!IndexCtx.handleDecl(D, (unsigned)SymbolRole::Dynamic))
+      return false;
+    IndexCtx.indexTypeSourceInfo(D->getReturnTypeSourceInfo(), D);
+    for (const auto *I : D->params())
+      handleDeclarator(I, D);
+
+    if (D->isThisDeclarationADefinition()) {
+      const Stmt *Body = D->getBody();
+      if (Body) {
+        IndexCtx.indexBody(Body, D, D);
+      }
+    }
+    return true;
+  }
+
+  bool VisitFunctionDecl(const FunctionDecl *D) {
+    if (D->isDeleted())
+      return true;
+
+    SymbolRoleSet Roles{};
+    SmallVector<SymbolRelation, 4> Relations;
+    if (auto *CXXMD = dyn_cast<CXXMethodDecl>(D)) {
+      if (CXXMD->isVirtual())
+        Roles |= (unsigned)SymbolRole::Dynamic;
+      for (auto I = CXXMD->begin_overridden_methods(),
+           E = CXXMD->end_overridden_methods(); I != E; ++I) {
+        Relations.emplace_back((unsigned)SymbolRole::RelationOverrideOf, *I);
+      }
+    }
+
+    if (!IndexCtx.handleDecl(D, Roles, Relations))
+      return false;
+    handleDeclarator(D);
+
+    if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(D)) {
+      // Constructor initializers.
+      for (const auto *Init : Ctor->inits()) {
+        if (Init->isWritten()) {
+          IndexCtx.indexTypeSourceInfo(Init->getTypeSourceInfo(), D);
+          if (const FieldDecl *Member = Init->getAnyMember())
+            IndexCtx.handleReference(Member, Init->getMemberLocation(), D, D,
+                                     (unsigned)SymbolRole::Write);
+          IndexCtx.indexBody(Init->getInit(), D, D);
+        }
+      }
+    }
+
+    if (D->isThisDeclarationADefinition()) {
+      const Stmt *Body = D->getBody();
+      if (Body) {
+        IndexCtx.indexBody(Body, D, D);
+      }
+    }
+    return true;
+  }
+
+  bool VisitVarDecl(const VarDecl *D) {
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    handleDeclarator(D);
+    IndexCtx.indexBody(D->getInit(), D);
+    return true;
+  }
+
+  bool VisitFieldDecl(const FieldDecl *D) {
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    handleDeclarator(D);
+    if (D->isBitField())
+      IndexCtx.indexBody(D->getBitWidth(), D);
+    else if (D->hasInClassInitializer())
+      IndexCtx.indexBody(D->getInClassInitializer(), D);
+    return true;
+  }
+
+  bool VisitObjCIvarDecl(const ObjCIvarDecl *D) {
+    if (D->getSynthesize()) {
+      // For synthesized ivars, use the location of the ObjC implementation,
+      // not the location of the property.
+      // Otherwise the header file containing the @interface will have different
+      // indexing contents based on whether the @implementation was present or
+      // not in the translation unit.
+      return IndexCtx.handleDecl(D,
+                                 cast<Decl>(D->getDeclContext())->getLocation(),
+                                 (unsigned)SymbolRole::Implicit);
+    }
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    handleDeclarator(D);
+    return true;
+  }
+
+  bool VisitMSPropertyDecl(const MSPropertyDecl *D) {
+    handleDeclarator(D);
+    return true;
+  }
+
+  bool VisitEnumConstantDecl(const EnumConstantDecl *D) {
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    IndexCtx.indexBody(D->getInitExpr(), D);
+    return true;
+  }
+
+  bool VisitTypedefNameDecl(const TypedefNameDecl *D) {
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
+    return true;
+  }
+
+  bool VisitTagDecl(const TagDecl *D) {
+    // Non-free standing tags are handled in indexTypeSourceInfo.
+    if (D->isFreeStanding()) {
+      if (D->isThisDeclarationADefinition()) {
+        IndexCtx.indexTagDecl(D);
+      } else {
+        auto *Parent = dyn_cast<NamedDecl>(D->getDeclContext());
+        return IndexCtx.handleReference(D, D->getLocation(), Parent,
+                                        D->getLexicalDeclContext(),
+                                        SymbolRoleSet());
+      }
+    }
+    return true;
+  }
+
+  bool VisitObjCInterfaceDecl(const ObjCInterfaceDecl *D) {
+    if (D->isThisDeclarationADefinition()) {
+      if (!IndexCtx.handleDecl(D))
+        return false;
+      IndexCtx.indexDeclContext(D);
+    } else {
+      return IndexCtx.handleReference(D, D->getLocation(), nullptr, nullptr,
+                                      SymbolRoleSet());
+    }
+    return true;
+  }
+
+  bool VisitObjCProtocolDecl(const ObjCProtocolDecl *D) {
+    if (D->isThisDeclarationADefinition()) {
+      if (!IndexCtx.handleDecl(D))
+        return false;
+      IndexCtx.indexDeclContext(D);
+    } else {
+      return IndexCtx.handleReference(D, D->getLocation(), nullptr, nullptr,
+                                      SymbolRoleSet());
+    }
+    return true;
+  }
+
+  bool VisitObjCImplementationDecl(const ObjCImplementationDecl *D) {
+    const ObjCInterfaceDecl *Class = D->getClassInterface();
+    if (!Class)
+      return true;
+
+    if (Class->isImplicitInterfaceDecl())
+      IndexCtx.handleDecl(Class);
+
+    if (!IndexCtx.handleDecl(D))
+      return false;
+
+    // Index the ivars first to make sure the synthesized ivars are indexed
+    // before indexing the methods that can reference them.
+    for (const auto *IvarI : D->ivars())
+      IndexCtx.indexDecl(IvarI);
+    for (const auto *I : D->decls()) {
+      if (!isa<ObjCIvarDecl>(I))
+        IndexCtx.indexDecl(I);
+    }
+
+    return true;
+  }
+
+  bool VisitObjCCategoryDecl(const ObjCCategoryDecl *D) {
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    IndexCtx.indexDeclContext(D);
+    return true;
+  }
+
+  bool VisitObjCCategoryImplDecl(const ObjCCategoryImplDecl *D) {
+    const ObjCCategoryDecl *Cat = D->getCategoryDecl();
+    if (!Cat)
+      return true;
+
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    IndexCtx.indexDeclContext(D);
+    return true;
+  }
+
+  bool VisitObjCMethodDecl(const ObjCMethodDecl *D) {
+    // Methods associated with a property, even user-declared ones, are
+    // handled when we handle the property.
+    if (D->isPropertyAccessor())
+      return true;
+
+    handleObjCMethod(D);
+    return true;
+  }
+
+  bool VisitObjCPropertyDecl(const ObjCPropertyDecl *D) {
+    if (ObjCMethodDecl *MD = D->getGetterMethodDecl())
+      if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
+        handleObjCMethod(MD);
+    if (ObjCMethodDecl *MD = D->getSetterMethodDecl())
+      if (MD->getLexicalDeclContext() == D->getLexicalDeclContext())
+        handleObjCMethod(MD);
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    IndexCtx.indexTypeSourceInfo(D->getTypeSourceInfo(), D);
+    return true;
+  }
+
+  bool VisitObjCPropertyImplDecl(const ObjCPropertyImplDecl *D) {
+    ObjCPropertyDecl *PD = D->getPropertyDecl();
+    if (!IndexCtx.handleReference(PD, D->getLocation(),
+                             /*Parent=*/cast<NamedDecl>(D->getDeclContext()),
+                             D->getDeclContext(), SymbolRoleSet(), {},
+                             /*RefE=*/nullptr, D))
+      return false;
+
+    if (D->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
+      return true;
+    assert(D->getPropertyImplementation() == ObjCPropertyImplDecl::Synthesize);
+    
+    if (ObjCIvarDecl *IvarD = D->getPropertyIvarDecl()) {
+      if (!IvarD->getSynthesize())
+        IndexCtx.handleReference(IvarD, D->getPropertyIvarDeclLoc(), nullptr,
+                                 D->getDeclContext(), SymbolRoleSet());
+    }
+
+    auto *ImplD = cast<ObjCImplDecl>(D->getDeclContext());
+    if (ObjCMethodDecl *MD = PD->getGetterMethodDecl()) {
+      if (MD->isPropertyAccessor() &&
+          !hasUserDefined(MD, ImplD))
+        IndexCtx.handleDecl(MD, D->getLocation(), SymbolRoleSet(), {}, ImplD);
+    }
+    if (ObjCMethodDecl *MD = PD->getSetterMethodDecl()) {
+      if (MD->isPropertyAccessor() &&
+          !hasUserDefined(MD, ImplD))
+        IndexCtx.handleDecl(MD, D->getLocation(), SymbolRoleSet(), {}, ImplD);
+    }
+    return true;
+  }
+
+  bool VisitNamespaceDecl(const NamespaceDecl *D) {
+    if (!IndexCtx.handleDecl(D))
+      return false;
+    IndexCtx.indexDeclContext(D);
+    return true;
+  }
+
+  bool VisitUsingDecl(const UsingDecl *D) {
+    const DeclContext *DC = D->getDeclContext()->getRedeclContext();
+    const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
+
+    IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
+                                         D->getLexicalDeclContext());
+    for (const auto *I : D->shadows())
+      IndexCtx.handleReference(I->getUnderlyingDecl(), D->getLocation(), Parent,
+                               D->getLexicalDeclContext(), SymbolRoleSet());
+    return true;
+  }
+
+  bool VisitUsingDirectiveDecl(const UsingDirectiveDecl *D) {
+    const DeclContext *DC = D->getDeclContext()->getRedeclContext();
+    const NamedDecl *Parent = dyn_cast<NamedDecl>(DC);
+
+    IndexCtx.indexNestedNameSpecifierLoc(D->getQualifierLoc(), Parent,
+                                         D->getLexicalDeclContext());
+    return IndexCtx.handleReference(D->getNominatedNamespaceAsWritten(),
+                                    D->getLocation(), Parent,
+                                    D->getLexicalDeclContext(),
+                                    SymbolRoleSet());
+  }
+
+  bool VisitClassTemplateSpecializationDecl(const
+                                           ClassTemplateSpecializationDecl *D) {
+    // FIXME: Notify subsequent callbacks if info comes from implicit
+    // instantiation.
+    if (D->isThisDeclarationADefinition())
+      IndexCtx.indexTagDecl(D);
+    return true;
+  }
+
+  bool VisitTemplateDecl(const TemplateDecl *D) {
+    // FIXME: Template parameters.
+    return Visit(D->getTemplatedDecl());
+  }
+
+  bool VisitFriendDecl(const FriendDecl *D) {
+    if (auto ND = D->getFriendDecl()) {
+      // FIXME: Ignore a class template in a dependent context, these are not
+      // linked properly with their redeclarations, ending up with duplicate
+      // USRs.
+      // See comment "Friend templates are visible in fairly strange ways." in
+      // SemaTemplate.cpp which precedes code that prevents the friend template
+      // from becoming visible from the enclosing context.
+      if (isa<ClassTemplateDecl>(ND) && D->getDeclContext()->isDependentContext())
+        return true;
+      return Visit(ND);
+    }
+    if (auto Ty = D->getFriendType()) {
+      IndexCtx.indexTypeSourceInfo(Ty, cast<NamedDecl>(D->getDeclContext()));
+    }
+    return true;
+  }
+
+  bool VisitImportDecl(const ImportDecl *D) {
+    return IndexCtx.importedModule(D);
+  }
+};
+
+} // anonymous namespace
+
+bool IndexingContext::indexDecl(const Decl *D) {
+  if (D->isImplicit() && shouldIgnoreIfImplicit(D))
+    return true;
+
+  if (isTemplateImplicitInstantiation(D))
+    return true;
+
+  IndexingDeclVisitor Visitor(*this);
+  bool ShouldContinue = Visitor.Visit(D);
+  if (!ShouldContinue)
+    return false;
+
+  if (!Visitor.Handled && isa<DeclContext>(D))
+    return indexDeclContext(cast<DeclContext>(D));
+
+  return true;
+}
+
+bool IndexingContext::indexDeclContext(const DeclContext *DC) {
+  for (const auto *I : DC->decls())
+    if (!indexDecl(I))
+      return false;
+  return true;
+}
+
+bool IndexingContext::indexTopLevelDecl(const Decl *D) {
+  if (D->getLocation().isInvalid())
+    return true;
+
+  if (isa<ObjCMethodDecl>(D))
+    return true; // Wait for the objc container.
+
+  return indexDecl(D);
+}
+
+bool IndexingContext::indexDeclGroupRef(DeclGroupRef DG) {
+  for (DeclGroupRef::iterator I = DG.begin(), E = DG.end(); I != E; ++I)
+    if (!indexTopLevelDecl(*I))
+      return false;
+  return true;
+}
diff --git a/clang/lib/Index/IndexSymbol.cpp b/clang/lib/Index/IndexSymbol.cpp
new file mode 100644
index 00000000000..c7c3c8c4d64
--- /dev/null
+++ b/clang/lib/Index/IndexSymbol.cpp
@@ -0,0 +1,187 @@
+//===--- IndexSymbol.cpp - Types and functions for indexing symbols -------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Index/IndexSymbol.h"
+#include "clang/AST/DeclCXX.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/DeclTemplate.h"
+
+using namespace clang;
+using namespace clang::index;
+
+SymbolInfo index::getSymbolInfo(const Decl *D) {
+  assert(D);
+  SymbolInfo Info;
+  Info.Kind = SymbolKind::Unknown;
+  Info.TemplateKind = SymbolCXXTemplateKind::NonTemplate;
+  Info.Lang = SymbolLanguage::C;
+
+  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::CXXClass;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
+    case TTK_Interface:
+      Info.Kind = SymbolKind::CXXInterface;
+      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 (isa<ClassTemplatePartialSpecializationDecl>(D)) {
+      Info.TemplateKind = SymbolCXXTemplateKind::TemplatePartialSpecialization;
+    } else if (isa<ClassTemplateSpecializationDecl>(D)) {
+      Info.TemplateKind = SymbolCXXTemplateKind::TemplateSpecialization;
+    }
+
+  } else {
+    switch (D->getKind()) {
+    case Decl::Typedef:
+      Info.Kind = SymbolKind::Typedef; break;
+    case Decl::Function:
+      Info.Kind = SymbolKind::Function;
+      break;
+    case Decl::ParmVar:
+      Info.Kind = SymbolKind::Variable;
+      break;
+    case Decl::Var:
+      Info.Kind = SymbolKind::Variable;
+      if (isa<CXXRecordDecl>(D->getDeclContext())) {
+        Info.Kind = SymbolKind::CXXStaticVariable;
+        Info.Lang = SymbolLanguage::CXX;
+      }
+      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::ObjCClass;
+      Info.Lang = SymbolLanguage::ObjC;
+      break;
+    case Decl::ObjCProtocol:
+      Info.Kind = SymbolKind::ObjCProtocol;
+      Info.Lang = SymbolLanguage::ObjC;
+      break;
+    case Decl::ObjCCategory:
+    case Decl::ObjCCategoryImpl:
+      Info.Kind = SymbolKind::ObjCCategory;
+      Info.Lang = SymbolLanguage::ObjC;
+      break;
+    case Decl::ObjCMethod:
+      if (cast<ObjCMethodDecl>(D)->isInstanceMethod())
+        Info.Kind = SymbolKind::ObjCInstanceMethod;
+      else
+        Info.Kind = SymbolKind::ObjCClassMethod;
+      Info.Lang = SymbolLanguage::ObjC;
+      break;
+    case Decl::ObjCProperty:
+      Info.Kind = SymbolKind::ObjCProperty;
+      Info.Lang = SymbolLanguage::ObjC;
+      break;
+    case Decl::ObjCIvar:
+      Info.Kind = SymbolKind::ObjCIvar;
+      Info.Lang = SymbolLanguage::ObjC;
+      break;
+    case Decl::Namespace:
+      Info.Kind = SymbolKind::CXXNamespace;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
+    case Decl::NamespaceAlias:
+      Info.Kind = SymbolKind::CXXNamespaceAlias;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
+    case Decl::CXXConstructor:
+      Info.Kind = SymbolKind::CXXConstructor;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
+    case Decl::CXXDestructor:
+      Info.Kind = SymbolKind::CXXDestructor;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
+    case Decl::CXXConversion:
+      Info.Kind = SymbolKind::CXXConversionFunction;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
+    case Decl::CXXMethod: {
+      const CXXMethodDecl *MD = cast<CXXMethodDecl>(D);
+      if (MD->isStatic())
+        Info.Kind = SymbolKind::CXXStaticMethod;
+      else
+        Info.Kind = SymbolKind::CXXInstanceMethod;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
+    }
+    case Decl::ClassTemplate:
+      Info.Kind = SymbolKind::CXXClass;
+      Info.TemplateKind = SymbolCXXTemplateKind::Template;
+      break;
+    case Decl::FunctionTemplate:
+      Info.Kind = SymbolKind::Function;
+      Info.TemplateKind = SymbolCXXTemplateKind::Template;
+      if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(
+                           cast<FunctionTemplateDecl>(D)->getTemplatedDecl())) {
+        if (isa<CXXConstructorDecl>(MD))
+          Info.Kind = SymbolKind::CXXConstructor;
+        else if (isa<CXXDestructorDecl>(MD))
+          Info.Kind = SymbolKind::CXXDestructor;
+        else if (isa<CXXConversionDecl>(MD))
+          Info.Kind = SymbolKind::CXXConversionFunction;
+        else {
+          if (MD->isStatic())
+            Info.Kind = SymbolKind::CXXStaticMethod;
+          else
+            Info.Kind = SymbolKind::CXXInstanceMethod;
+        }
+      }
+      break;
+    case Decl::TypeAliasTemplate:
+      Info.Kind = SymbolKind::CXXTypeAlias;
+      Info.TemplateKind = SymbolCXXTemplateKind::Template;
+      break;
+    case Decl::TypeAlias:
+      Info.Kind = SymbolKind::CXXTypeAlias;
+      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.TemplateKind = SymbolCXXTemplateKind::TemplateSpecialization;
+  }
+
+  if (Info.TemplateKind != SymbolCXXTemplateKind::NonTemplate)
+    Info.Lang = SymbolLanguage::CXX;
+
+  return Info;
+}
diff --git a/clang/lib/Index/IndexTypeSourceInfo.cpp b/clang/lib/Index/IndexTypeSourceInfo.cpp
new file mode 100644
index 00000000000..619a9a48bef
--- /dev/null
+++ b/clang/lib/Index/IndexTypeSourceInfo.cpp
@@ -0,0 +1,202 @@
+//===- IndexTypeSourceInfo.cpp - Indexing types ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IndexingContext.h"
+#include "clang/AST/RecursiveASTVisitor.h"
+
+using namespace clang;
+using namespace index;
+
+namespace {
+
+class TypeIndexer : public RecursiveASTVisitor<TypeIndexer> {
+  IndexingContext &IndexCtx;
+  const NamedDecl *Parent;
+  const DeclContext *ParentDC;
+  bool IsBase;
+  SmallVector<SymbolRelation, 3> Relations;
+
+  typedef RecursiveASTVisitor<TypeIndexer> base;
+
+public:
+  TypeIndexer(IndexingContext &indexCtx, const NamedDecl *parent,
+              const DeclContext *DC, bool isBase)
+    : IndexCtx(indexCtx), Parent(parent), ParentDC(DC), IsBase(isBase) {
+    if (IsBase) {
+      assert(Parent);
+      Relations.emplace_back((unsigned)SymbolRole::RelationBaseOf, Parent);
+    }
+  }
+  
+  bool shouldWalkTypesOfTypeLocs() const { return false; }
+
+  bool VisitTypedefTypeLoc(TypedefTypeLoc TL) {
+    return IndexCtx.handleReference(TL.getTypedefNameDecl(), TL.getNameLoc(),
+                                    Parent, ParentDC, SymbolRoleSet(),
+                                    Relations);
+  }
+
+#define TRY_TO(CALL_EXPR)                                                      \
+  do {                                                                         \
+    if (!CALL_EXPR)                                                            \
+      return false;                                                            \
+  } while (0)
+
+  bool traverseParamVarHelper(ParmVarDecl *D) {
+    TRY_TO(TraverseNestedNameSpecifierLoc(D->getQualifierLoc()));
+    if (D->getTypeSourceInfo())
+      TRY_TO(TraverseTypeLoc(D->getTypeSourceInfo()->getTypeLoc()));
+    return true;
+  }
+
+  bool TraverseParmVarDecl(ParmVarDecl *D) {
+    // Avoid visiting default arguments from the definition that were already
+    // visited in the declaration.
+    // FIXME: A free function definition can have default arguments.
+    // Avoiding double visitaiton of default arguments should be handled by the
+    // visitor probably with a bit in the AST to indicate if the attached
+    // default argument was 'inherited' or written in source.
+    if (auto FD = dyn_cast<FunctionDecl>(D->getDeclContext())) {
+      if (FD->isThisDeclarationADefinition()) {
+        return traverseParamVarHelper(D);
+      }
+    }
+
+    return base::TraverseParmVarDecl(D);
+  }
+
+  bool TraverseNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS) {
+    IndexCtx.indexNestedNameSpecifierLoc(NNS, Parent, ParentDC);
+    return true;
+  }
+
+  bool VisitTagTypeLoc(TagTypeLoc TL) {
+    TagDecl *D = TL.getDecl();
+    if (D->getParentFunctionOrMethod())
+      return true;
+
+    if (TL.isDefinition()) {
+      IndexCtx.indexTagDecl(D);
+      return true;
+    }
+
+    return IndexCtx.handleReference(D, TL.getNameLoc(),
+                                    Parent, ParentDC, SymbolRoleSet(),
+                                    Relations);
+  }
+
+  bool VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
+    return IndexCtx.handleReference(TL.getIFaceDecl(), TL.getNameLoc(),
+                                    Parent, ParentDC, SymbolRoleSet());
+  }
+
+  bool VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
+    for (unsigned i = 0, e = TL.getNumProtocols(); i != e; ++i) {
+      IndexCtx.handleReference(TL.getProtocol(i), TL.getProtocolLoc(i),
+                               Parent, ParentDC, SymbolRoleSet());
+    }
+    return true;
+  }
+
+  bool VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc TL) {
+    if (const TemplateSpecializationType *T = TL.getTypePtr()) {
+      if (IndexCtx.shouldIndexImplicitTemplateInsts()) {
+        if (CXXRecordDecl *RD = T->getAsCXXRecordDecl())
+          IndexCtx.handleReference(RD, TL.getTemplateNameLoc(),
+                                   Parent, ParentDC, SymbolRoleSet(), Relations);
+      } else {
+        if (const TemplateDecl *D = T->getTemplateName().getAsTemplateDecl())
+          IndexCtx.handleReference(D, TL.getTemplateNameLoc(),
+                                   Parent, ParentDC, SymbolRoleSet(), Relations);
+      }
+    }
+    return true;
+  }
+
+  bool TraverseStmt(Stmt *S) {
+    IndexCtx.indexBody(S, Parent, ParentDC);
+    return true;
+  }
+};
+
+} // anonymous namespace
+
+void IndexingContext::indexTypeSourceInfo(TypeSourceInfo *TInfo,
+                                          const NamedDecl *Parent,
+                                          const DeclContext *DC,
+                                          bool isBase) {
+  if (!TInfo || TInfo->getTypeLoc().isNull())
+    return;
+  
+  indexTypeLoc(TInfo->getTypeLoc(), Parent, DC, isBase);
+}
+
+void IndexingContext::indexTypeLoc(TypeLoc TL,
+                                   const NamedDecl *Parent,
+                                   const DeclContext *DC,
+                                   bool isBase) {
+  if (TL.isNull())
+    return;
+
+  if (!DC)
+    DC = Parent->getLexicalDeclContext();
+  TypeIndexer(*this, Parent, DC, isBase).TraverseTypeLoc(TL);
+}
+
+void IndexingContext::indexNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
+                                                  const NamedDecl *Parent,
+                                                  const DeclContext *DC) {
+  if (!NNS)
+    return;
+
+  if (NestedNameSpecifierLoc Prefix = NNS.getPrefix())
+    indexNestedNameSpecifierLoc(Prefix, Parent, DC);
+
+  if (!DC)
+    DC = Parent->getLexicalDeclContext();
+  SourceLocation Loc = NNS.getSourceRange().getBegin();
+
+  switch (NNS.getNestedNameSpecifier()->getKind()) {
+  case NestedNameSpecifier::Identifier:
+  case NestedNameSpecifier::Global:
+  case NestedNameSpecifier::Super:
+    break;
+
+  case NestedNameSpecifier::Namespace:
+    handleReference(NNS.getNestedNameSpecifier()->getAsNamespace(),
+                    Loc, Parent, DC, SymbolRoleSet());
+    break;
+  case NestedNameSpecifier::NamespaceAlias:
+    handleReference(NNS.getNestedNameSpecifier()->getAsNamespaceAlias(),
+                    Loc, Parent, DC, SymbolRoleSet());
+    break;
+
+  case NestedNameSpecifier::TypeSpec:
+  case NestedNameSpecifier::TypeSpecWithTemplate:
+    indexTypeLoc(NNS.getTypeLoc(), Parent, DC);
+    break;
+  }
+}
+
+void IndexingContext::indexTagDecl(const TagDecl *D) {
+  if (!shouldIndexFunctionLocalSymbols() && isFunctionLocalDecl(D))
+    return;
+
+  if (handleDecl(D)) {
+    if (D->isThisDeclarationADefinition()) {
+      indexNestedNameSpecifierLoc(D->getQualifierLoc(), D);
+      if (auto CXXRD = dyn_cast<CXXRecordDecl>(D)) {
+        for (const auto &I : CXXRD->bases()) {
+          indexTypeSourceInfo(I.getTypeSourceInfo(), CXXRD, CXXRD, /*isBase=*/true);
+        }
+      }
+      indexDeclContext(D);
+    }
+  }
+}
diff --git a/clang/lib/Index/IndexingAction.cpp b/clang/lib/Index/IndexingAction.cpp
new file mode 100644
index 00000000000..3f7ef43e7dc
--- /dev/null
+++ b/clang/lib/Index/IndexingAction.cpp
@@ -0,0 +1,140 @@
+//===- IndexingAction.cpp - Frontend index action -------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Index/IndexingAction.h"
+#include "clang/Index/IndexDataConsumer.h"
+#include "IndexingContext.h"
+#include "clang/Frontend/FrontendAction.h"
+#include "clang/Frontend/MultiplexConsumer.h"
+#include "clang/Lex/Preprocessor.h"
+
+using namespace clang;
+using namespace clang::index;
+
+void IndexDataConsumer::_anchor() {}
+
+bool IndexDataConsumer::handleDeclOccurence(const Decl *D, SymbolRoleSet Roles,
+                                            ArrayRef<SymbolRelation> Relations,
+                                            FileID FID, unsigned Offset,
+                                            ASTNodeInfo ASTNode) {
+  return true;
+}
+
+bool IndexDataConsumer::handleMacroOccurence(const IdentifierInfo *Name,
+                                             const MacroInfo *MI, SymbolRoleSet Roles,
+                                             FileID FID, unsigned Offset) {
+  return true;
+}
+
+bool IndexDataConsumer::handleModuleOccurence(const ImportDecl *ImportD,
+                                              SymbolRoleSet Roles,
+                                              FileID FID, unsigned Offset) {
+  return true;
+}
+
+namespace {
+
+class IndexASTConsumer : public ASTConsumer {
+  IndexingContext &IndexCtx;
+
+public:
+  IndexASTConsumer(IndexingContext &IndexCtx)
+    : IndexCtx(IndexCtx) {}
+
+protected:
+  void Initialize(ASTContext &Context) override {
+    IndexCtx.setASTContext(Context);
+  }
+
+  bool HandleTopLevelDecl(DeclGroupRef DG) override {
+    return IndexCtx.indexDeclGroupRef(DG);
+  }
+
+  void HandleInterestingDecl(DeclGroupRef DG) override {
+    // Ignore deserialized decls.
+  }
+
+  void HandleTopLevelDeclInObjCContainer(DeclGroupRef DG) override {
+    IndexCtx.indexDeclGroupRef(DG);
+  }
+
+  void HandleTranslationUnit(ASTContext &Ctx) override {
+  }
+};
+
+class IndexAction : public WrapperFrontendAction {
+  IndexingOptions IndexOpts;
+  std::shared_ptr<IndexDataConsumer> DataConsumer;
+  std::unique_ptr<IndexingContext> IndexCtx;
+
+public:
+  IndexAction(std::unique_ptr<FrontendAction> WrappedAction,
+              std::shared_ptr<IndexDataConsumer> DataConsumer,
+              IndexingOptions Opts)
+    : WrapperFrontendAction(std::move(WrappedAction)),
+      IndexOpts(Opts),
+      DataConsumer(std::move(DataConsumer)) {}
+
+protected:
+  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
+                                                 StringRef InFile) override;
+  void EndSourceFileAction() override;
+};
+
+} // anonymous namespace
+
+void IndexAction::EndSourceFileAction() {
+  // Invoke wrapped action's method.
+  WrapperFrontendAction::EndSourceFileAction();
+
+  bool IndexActionFailed = !IndexCtx;
+  if (!IndexActionFailed)
+    DataConsumer->finish();
+}
+
+std::unique_ptr<ASTConsumer>
+IndexAction::CreateASTConsumer(CompilerInstance &CI, StringRef InFile) {
+  auto OtherConsumer = WrapperFrontendAction::CreateASTConsumer(CI, InFile);
+  if (!OtherConsumer)
+    return nullptr;
+
+  IndexCtx.reset(new IndexingContext(IndexOpts, *DataConsumer));
+
+  std::vector<std::unique_ptr<ASTConsumer>> Consumers;
+  Consumers.push_back(std::move(OtherConsumer));
+  Consumers.push_back(llvm::make_unique<IndexASTConsumer>(*IndexCtx));
+  return llvm::make_unique<MultiplexConsumer>(std::move(Consumers));
+}
+
+std::unique_ptr<FrontendAction>
+index::createIndexingAction(std::unique_ptr<FrontendAction> WrappedAction,
+                            std::shared_ptr<IndexDataConsumer> DataConsumer,
+                            IndexingOptions Opts) {
+  return llvm::make_unique<IndexAction>(std::move(WrappedAction),
+                                        std::move(DataConsumer),
+                                        Opts);
+}
+
+
+static bool topLevelDeclVisitor(void *context, const Decl *D) {
+  IndexingContext &IndexCtx = *static_cast<IndexingContext*>(context);
+  return IndexCtx.indexTopLevelDecl(D);
+}
+
+static void indexTranslationUnit(ASTUnit &Unit, IndexingContext &IndexCtx) {
+  Unit.visitLocalTopLevelDecls(&IndexCtx, topLevelDeclVisitor);
+}
+
+void index::indexASTUnit(ASTUnit &Unit,
+                         std::shared_ptr<IndexDataConsumer> DataConsumer,
+                         IndexingOptions Opts) {
+  IndexingContext IndexCtx(Opts, *DataConsumer);
+  IndexCtx.setASTContext(Unit.getASTContext());
+  indexTranslationUnit(Unit, IndexCtx);
+}
diff --git a/clang/lib/Index/IndexingContext.cpp b/clang/lib/Index/IndexingContext.cpp
new file mode 100644
index 00000000000..91fbbfb2684
--- /dev/null
+++ b/clang/lib/Index/IndexingContext.cpp
@@ -0,0 +1,325 @@
+//===- IndexingContext.cpp - Indexing context data ------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "IndexingContext.h"
+#include "clang/Index/IndexDataConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/DeclTemplate.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/Basic/SourceManager.h"
+
+using namespace clang;
+using namespace index;
+
+bool IndexingContext::shouldIndexFunctionLocalSymbols() const {
+  return IndexOpts.IndexFunctionLocals;
+}
+
+bool IndexingContext::handleDecl(const Decl *D,
+                                 SymbolRoleSet Roles,
+                                 ArrayRef<SymbolRelation> Relations) {
+  return handleDeclOccurrence(D, D->getLocation(), /*IsRef=*/false,
+                              cast<Decl>(D->getDeclContext()), Roles, Relations,
+                              nullptr, nullptr, D->getDeclContext());
+}
+
+bool IndexingContext::handleDecl(const Decl *D, SourceLocation Loc,
+                                 SymbolRoleSet Roles,
+                                 ArrayRef<SymbolRelation> Relations,
+                                 const DeclContext *DC) {
+  if (!DC)
+    DC = D->getDeclContext();
+  return handleDeclOccurrence(D, Loc, /*IsRef=*/false, cast<Decl>(DC),
+                              Roles, Relations,
+                              nullptr, nullptr, DC);
+}
+
+bool IndexingContext::handleReference(const NamedDecl *D, SourceLocation Loc,
+                                      const NamedDecl *Parent,
+                                      const DeclContext *DC,
+                                      SymbolRoleSet Roles,
+                                      ArrayRef<SymbolRelation> Relations,
+                                      const Expr *RefE,
+                                      const Decl *RefD) {
+  if (!shouldIndexFunctionLocalSymbols() && isFunctionLocalDecl(D))
+    return true;
+
+  if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D))
+    return true;
+    
+  return handleDeclOccurrence(D, Loc, /*IsRef=*/true, Parent, Roles, Relations,
+                              RefE, RefD, DC);
+}
+
+bool IndexingContext::importedModule(const ImportDecl *ImportD) {
+  SourceLocation Loc = ImportD->getLocation();
+  SourceManager &SM = Ctx->getSourceManager();
+  Loc = SM.getFileLoc(Loc);
+  if (Loc.isInvalid())
+    return true;
+
+  FileID FID;
+  unsigned Offset;
+  std::tie(FID, Offset) = SM.getDecomposedLoc(Loc);
+  if (FID.isInvalid())
+    return true;
+
+  bool Invalid = false;
+  const SrcMgr::SLocEntry &SEntry = SM.getSLocEntry(FID, &Invalid);
+  if (Invalid || !SEntry.isFile())
+    return true;
+
+  if (SEntry.getFile().getFileCharacteristic() != SrcMgr::C_User) {
+    switch (IndexOpts.SystemSymbolFilter) {
+    case IndexingOptions::SystemSymbolFilterKind::None:
+    case IndexingOptions::SystemSymbolFilterKind::DeclarationsOnly:
+      return true;
+    case IndexingOptions::SystemSymbolFilterKind::All:
+      break;
+    }
+  }
+
+  SymbolRoleSet Roles{};
+  if (ImportD->isImplicit())
+    Roles |= (unsigned)SymbolRole::Implicit;
+
+  return DataConsumer.handleModuleOccurence(ImportD, Roles, FID, Offset);
+}
+
+bool IndexingContext::isFunctionLocalDecl(const Decl *D) {
+  assert(D);
+
+  if (isa<TemplateTemplateParmDecl>(D))
+    return true;
+
+  if (!D->getParentFunctionOrMethod())
+    return false;
+
+  if (const NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
+    switch (ND->getFormalLinkage()) {
+    case NoLinkage:
+    case VisibleNoLinkage:
+    case InternalLinkage:
+      return true;
+    case UniqueExternalLinkage:
+      llvm_unreachable("Not a sema linkage");
+    case ExternalLinkage:
+      return false;
+    }
+  }
+
+  return true;
+}
+
+bool IndexingContext::isTemplateImplicitInstantiation(const Decl *D) {
+  TemplateSpecializationKind TKind = TSK_Undeclared;
+  if (const ClassTemplateSpecializationDecl *
+      SD = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
+    TKind = SD->getSpecializationKind();
+  }
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    TKind = FD->getTemplateSpecializationKind();
+  }
+  switch (TKind) {
+    case TSK_Undeclared:
+    case TSK_ExplicitSpecialization:
+      return false;
+    case TSK_ImplicitInstantiation:
+    case TSK_ExplicitInstantiationDeclaration:
+    case TSK_ExplicitInstantiationDefinition:
+      return true;
+  }
+}
+
+bool IndexingContext::shouldIgnoreIfImplicit(const Decl *D) {
+  if (isa<ObjCInterfaceDecl>(D))
+    return false;
+  if (isa<ObjCCategoryDecl>(D))
+    return false;
+  if (isa<ObjCIvarDecl>(D))
+    return false;
+  if (isa<ObjCMethodDecl>(D))
+    return false;
+  if (isa<ImportDecl>(D))
+    return false;
+  return true;
+}
+
+static const Decl *adjustTemplateImplicitInstantiation(const Decl *D) {
+  if (const ClassTemplateSpecializationDecl *
+      SD = dyn_cast<ClassTemplateSpecializationDecl>(D)) {
+    return SD->getTemplateInstantiationPattern();
+  }
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    return FD->getTemplateInstantiationPattern();
+  }
+  return nullptr;
+}
+
+static bool isDeclADefinition(const Decl *D, ASTContext &Ctx) {
+  if (auto VD = dyn_cast<VarDecl>(D))
+    return VD->isThisDeclarationADefinition(Ctx);
+
+  if (auto FD = dyn_cast<FunctionDecl>(D))
+    return FD->isThisDeclarationADefinition();
+
+  if (auto TD = dyn_cast<TagDecl>(D))
+    return TD->isThisDeclarationADefinition();
+
+  if (auto MD = dyn_cast<ObjCMethodDecl>(D))
+    return MD->isThisDeclarationADefinition();
+
+  if (isa<TypedefNameDecl>(D) ||
+      isa<EnumConstantDecl>(D) ||
+      isa<FieldDecl>(D) ||
+      isa<MSPropertyDecl>(D) ||
+      isa<ObjCImplDecl>(D) ||
+      isa<ObjCPropertyImplDecl>(D))
+    return true;
+
+  return false;
+}
+
+static const Decl *adjustParent(const Decl *Parent) {
+  if (!Parent)
+    return nullptr;
+  for (;; Parent = cast<Decl>(Parent->getDeclContext())) {
+    if (isa<TranslationUnitDecl>(Parent))
+      return nullptr;
+    if (isa<LinkageSpecDecl>(Parent) || isa<BlockDecl>(Parent))
+      continue;
+    if (auto NS = dyn_cast<NamespaceDecl>(Parent)) {
+      if (NS->isAnonymousNamespace())
+        continue;
+    } else if (auto EnumD = dyn_cast<EnumDecl>(Parent)) {
+      // Move enumerators under anonymous enum to the enclosing parent.
+      if (EnumD->getDeclName().isEmpty())
+        continue;
+    } else if (auto RD = dyn_cast<RecordDecl>(Parent)) {
+      if (RD->isAnonymousStructOrUnion())
+        continue;
+    } else if (auto FD = dyn_cast<FieldDecl>(Parent)) {
+      if (FD->getDeclName().isEmpty())
+        continue;
+    }
+    return Parent;
+  }
+}
+
+static const Decl *getCanonicalDecl(const Decl *D) {
+  D = D->getCanonicalDecl();
+  if (auto TD = dyn_cast<TemplateDecl>(D)) {
+    D = TD->getTemplatedDecl();
+    assert(D->isCanonicalDecl());
+  }
+
+  return D;
+}
+
+bool IndexingContext::handleDeclOccurrence(const Decl *D, SourceLocation Loc,
+                                           bool IsRef, const Decl *Parent,
+                                           SymbolRoleSet Roles,
+                                           ArrayRef<SymbolRelation> Relations,
+                                           const Expr *OrigE,
+                                           const Decl *OrigD,
+                                           const DeclContext *ContainerDC) {
+  if (D->isImplicit() && !isa<ObjCMethodDecl>(D))
+    return true;
+  if (!isa<NamedDecl>(D) ||
+      (cast<NamedDecl>(D)->getDeclName().isEmpty() &&
+       !isa<TagDecl>(D) && !isa<ObjCCategoryDecl>(D)))
+    return true;
+
+  SourceManager &SM = Ctx->getSourceManager();
+  Loc = SM.getFileLoc(Loc);
+  if (Loc.isInvalid())
+    return true;
+
+  FileID FID;
+  unsigned Offset;
+  std::tie(FID, Offset) = SM.getDecomposedLoc(Loc);
+  if (FID.isInvalid())
+    return true;
+
+  bool Invalid = false;
+  const SrcMgr::SLocEntry &SEntry = SM.getSLocEntry(FID, &Invalid);
+  if (Invalid || !SEntry.isFile())
+    return true;
+
+  if (SEntry.getFile().getFileCharacteristic() != SrcMgr::C_User) {
+    switch (IndexOpts.SystemSymbolFilter) {
+    case IndexingOptions::SystemSymbolFilterKind::None:
+      return true;
+    case IndexingOptions::SystemSymbolFilterKind::DeclarationsOnly:
+      if (IsRef)
+        return true;
+      break;
+    case IndexingOptions::SystemSymbolFilterKind::All:
+      break;
+    }
+  }
+
+  if (isTemplateImplicitInstantiation(D)) {
+    if (!IsRef)
+      return true;
+    D = adjustTemplateImplicitInstantiation(D);
+    if (!D)
+      return true;
+    assert(!isTemplateImplicitInstantiation(D));
+  }
+
+  if (!OrigD)
+    OrigD = D;
+
+  if (IsRef)
+    Roles |= (unsigned)SymbolRole::Reference;
+  else if (isDeclADefinition(D, *Ctx))
+    Roles |= (unsigned)SymbolRole::Definition;
+  else
+    Roles |= (unsigned)SymbolRole::Declaration;
+
+  D = getCanonicalDecl(D);
+  if (D->isImplicit() && !isa<ObjCMethodDecl>(D)) {
+    // operator new declarations will link to the implicit one as canonical.
+    return true;
+  }
+  Parent = adjustParent(Parent);
+  if (Parent)
+    Parent = getCanonicalDecl(Parent);
+  assert(!Parent || !Parent->isImplicit() ||
+         isa<ObjCInterfaceDecl>(Parent) || isa<ObjCMethodDecl>(Parent));
+
+  SmallVector<SymbolRelation, 6> FinalRelations;
+  FinalRelations.reserve(Relations.size()+1);
+
+  auto addRelation = [&](SymbolRelation Rel) {
+    auto It = std::find_if(FinalRelations.begin(), FinalRelations.end(),
+                [&](SymbolRelation Elem)->bool {
+                  return Elem.RelatedSymbol == Rel.RelatedSymbol;
+                });
+    if (It != FinalRelations.end()) {
+      It->Roles |= Rel.Roles;
+    } else {
+      FinalRelations.push_back(Rel);
+    }
+    Roles |= Rel.Roles;
+  };
+
+  if (!IsRef && Parent && !cast<DeclContext>(Parent)->isFunctionOrMethod()) {
+    addRelation(SymbolRelation{(unsigned)SymbolRole::RelationChildOf, Parent});
+  }
+  for (auto &Rel : Relations) {
+    addRelation(SymbolRelation(Rel.Roles,
+                               Rel.RelatedSymbol->getCanonicalDecl()));
+  }
+
+  IndexDataConsumer::ASTNodeInfo Node{ OrigE, OrigD, Parent, ContainerDC };
+  return DataConsumer.handleDeclOccurence(D, Roles, FinalRelations, FID, Offset,
+                                          Node);
+}
diff --git a/clang/lib/Index/IndexingContext.h b/clang/lib/Index/IndexingContext.h
new file mode 100644
index 00000000000..774650547f8
--- /dev/null
+++ b/clang/lib/Index/IndexingContext.h
@@ -0,0 +1,121 @@
+//===- IndexingContext.h - Indexing context data ----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_LIB_INDEX_INDEXINGCONTEXT_H
+#define LLVM_CLANG_LIB_INDEX_INDEXINGCONTEXT_H
+
+#include "clang/Basic/LLVM.h"
+#include "clang/Index/IndexSymbol.h"
+#include "clang/Index/IndexingAction.h"
+#include "llvm/ADT/ArrayRef.h"
+
+namespace clang {
+  class ASTContext;
+  class Decl;
+  class DeclGroupRef;
+  class ImportDecl;
+  class TagDecl;
+  class TypeSourceInfo;
+  class NamedDecl;
+  class ObjCMethodDecl;
+  class DeclContext;
+  class NestedNameSpecifierLoc;
+  class Stmt;
+  class Expr;
+  class TypeLoc;
+  class SourceLocation;
+
+namespace index {
+  class IndexDataConsumer;
+
+class IndexingContext {
+  IndexingOptions IndexOpts;
+  IndexDataConsumer &DataConsumer;
+  ASTContext *Ctx = nullptr;
+
+public:
+  IndexingContext(IndexingOptions IndexOpts, IndexDataConsumer &DataConsumer)
+    : IndexOpts(IndexOpts), DataConsumer(DataConsumer) {}
+
+  const IndexingOptions &getIndexOpts() const { return IndexOpts; }
+  IndexDataConsumer &getDataConsumer() { return DataConsumer; }
+
+  void setASTContext(ASTContext &ctx) { Ctx = &ctx; }
+
+  bool shouldSuppressRefs() const {
+    return false;
+  }
+
+  bool shouldIndexFunctionLocalSymbols() const;
+
+  bool shouldIndexImplicitTemplateInsts() const {
+    return false;
+  }
+
+  static bool isFunctionLocalDecl(const Decl *D);
+  static bool isTemplateImplicitInstantiation(const Decl *D);
+
+  bool handleDecl(const Decl *D, SymbolRoleSet Roles = SymbolRoleSet(),
+                  ArrayRef<SymbolRelation> Relations = {});
+
+  bool handleDecl(const Decl *D, SourceLocation Loc,
+                  SymbolRoleSet Roles = SymbolRoleSet(),
+                  ArrayRef<SymbolRelation> Relations = {},
+                  const DeclContext *DC = nullptr);
+
+  bool handleReference(const NamedDecl *D, SourceLocation Loc,
+                       const NamedDecl *Parent,
+                       const DeclContext *DC,
+                       SymbolRoleSet Roles,
+                       ArrayRef<SymbolRelation> Relations = {},
+                       const Expr *RefE = nullptr,
+                       const Decl *RefD = nullptr);
+
+  bool importedModule(const ImportDecl *ImportD);
+
+  bool indexDecl(const Decl *D);
+
+  void indexTagDecl(const TagDecl *D);
+
+  void indexTypeSourceInfo(TypeSourceInfo *TInfo, const NamedDecl *Parent,
+                           const DeclContext *DC = nullptr,
+                           bool isBase = false);
+
+  void indexTypeLoc(TypeLoc TL, const NamedDecl *Parent,
+                    const DeclContext *DC = nullptr,
+                    bool isBase = false);
+
+  void indexNestedNameSpecifierLoc(NestedNameSpecifierLoc NNS,
+                                   const NamedDecl *Parent,
+                                   const DeclContext *DC = nullptr);
+
+  bool indexDeclContext(const DeclContext *DC);
+
+  void indexBody(const Stmt *S, const NamedDecl *Parent,
+                 const DeclContext *DC = nullptr);
+
+  bool indexTopLevelDecl(const Decl *D);
+  bool indexDeclGroupRef(DeclGroupRef DG);
+
+private:
+  bool shouldIgnoreIfImplicit(const Decl *D);
+
+  bool handleDeclOccurrence(const Decl *D, SourceLocation Loc,
+                            bool IsRef, const Decl *Parent,
+                            SymbolRoleSet Roles,
+                            ArrayRef<SymbolRelation> Relations,
+                            const Expr *RefE,
+                            const Decl *RefD,
+                            const DeclContext *ContainerDC);
+};
+
+} // end namespace index
+} // end namespace clang
+
+#endif