IndexBody.cpp

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//===- IndexBody.cpp - Indexing statements --------------------------------===//
//
// 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 "IndexingContext.h"
#include "clang/AST/ASTConcept.h"
#include "clang/AST/ASTLambda.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/ExprConcepts.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/AST/Type.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;
 
  Stmt *getParentStmt() const {
    return StmtStack.size() < 2 ? nullptr : StmtStack.end()[-2];
  }
public:
  BodyIndexer(IndexingContext &indexCtx,
              const NamedDecl *Parent, const DeclContext *DC)
    : IndexCtx(indexCtx), Parent(Parent), ParentDC(DC) { }
 
  bool shouldWalkTypesOfTypeLocs() const { return false; }
 
  bool dataTraverseStmtPre(Stmt *S) {
    StmtStack.push_back(S);
    return true;
  }
 
  bool dataTraverseStmtPost(Stmt *S) {
    assert(StmtStack.back() == S);
    StmtStack.pop_back();
    return true;
  }
 
  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) {
        if (BO->getLHS()->IgnoreParenCasts() == E)
          Roles |= (unsigned)SymbolRole::Write;
      } else if (auto CA = dyn_cast<CompoundAssignOperator>(Parent)) {
        if (CA->getLHS()->IgnoreParenCasts() == E) {
          Roles |= (unsigned)SymbolRole::Read;
          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 CE = dyn_cast<CallExpr>(Parent)) {
      if (CE->getCallee()->IgnoreParenCasts() == E) {
        addCallRole(Roles, Relations);
        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;
  }
 
  void addCallRole(SymbolRoleSet &Roles,
                   SmallVectorImpl<SymbolRelation> &Relations) {
    Roles |= (unsigned)SymbolRole::Call;
    if (auto *FD = dyn_cast<FunctionDecl>(ParentDC))
      Relations.emplace_back((unsigned)SymbolRole::RelationCalledBy, FD);
    else if (auto *MD = dyn_cast<ObjCMethodDecl>(ParentDC))
      Relations.emplace_back((unsigned)SymbolRole::RelationCalledBy, MD);
  }
 
  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 VisitGotoStmt(GotoStmt *S) {
    return IndexCtx.handleReference(S->getLabel(), S->getLabelLoc(), Parent,
                                    ParentDC);
  }
 
  bool VisitLabelStmt(LabelStmt *S) {
    if (IndexCtx.shouldIndexFunctionLocalSymbols())
      return IndexCtx.handleDecl(S->getDecl());
    return true;
  }
 
  bool VisitMemberExpr(MemberExpr *E) {
    SourceLocation Loc = E->getMemberLoc();
    if (Loc.isInvalid())
      Loc = E->getBeginLoc();
    SmallVector<SymbolRelation, 4> Relations;
    SymbolRoleSet Roles = getRolesForRef(E, Relations);
    return IndexCtx.handleReference(E->getMemberDecl(), Loc,
                                    Parent, ParentDC, Roles, Relations, E);
  }
 
  bool indexDependentReference(
      const Expr *E, const Type *T, const DeclarationNameInfo &NameInfo,
      llvm::function_ref<bool(const NamedDecl *ND)> Filter) {
    if (!T)
      return true;
    const TemplateSpecializationType *TST =
        T->getAs<TemplateSpecializationType>();