lib/StaticAnalyzer/Core/AggExprVisitor.cpp

   1 //=-- AggExprVisitor.cpp - evaluating expressions of C++ class type -*- C++ -*-=
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file defines AggExprVisitor class, which contains lots of boiler
  11 // plate code for evaluating expressions of C++ class type.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "clang/StaticAnalyzer/PathSensitive/ExprEngine.h"
  16 #include "clang/AST/StmtVisitor.h"
  17
  18 using namespace clang;
  19 using namespace ento;
  20
  21 namespace {
  22 /// AggExprVisitor is designed after AggExprEmitter of the CodeGen module.  It
  23 /// is used for evaluating exprs of C++ object type. Evaluating such exprs
  24 /// requires a destination pointer pointing to the object being evaluated
  25 /// into. Passing such a pointer around would pollute the Visit* interface of
  26 /// ExprEngine. AggExprVisitor encapsulates code that goes through various
  27 /// cast and construct exprs (and others), and at the final point, dispatches
  28 /// back to the ExprEngine to let the real evaluation logic happen.
  29 class AggExprVisitor : public StmtVisitor<AggExprVisitor> {
  30   const MemRegion *Dest;
  31   ExplodedNode *Pred;
  32   ExplodedNodeSet &DstSet;
  33   ExprEngine &Eng;
  34
  35 public:
  36   AggExprVisitor(const MemRegion *dest, ExplodedNode *N, ExplodedNodeSet &dst,
  37                  ExprEngine &eng)
  38     : Dest(dest), Pred(N), DstSet(dst), Eng(eng) {}
  39
  40   void VisitCastExpr(CastExpr *E);
  41   void VisitCXXConstructExpr(CXXConstructExpr *E);
  42 };
  43 }
  44
  45 void AggExprVisitor::VisitCastExpr(CastExpr *E) {
  46   switch (E->getCastKind()) {
  47   default:
  48     assert(0 && "Unhandled cast kind");
  49   case CK_NoOp:
  50   case CK_ConstructorConversion:
  51     Visit(E->getSubExpr());
  52     break;
  53   }
  54 }
  55
  56 void AggExprVisitor::VisitCXXConstructExpr(CXXConstructExpr *E) {
  57   Eng.VisitCXXConstructExpr(E, Dest, Pred, DstSet);
  58 }
  59
  60 void ExprEngine::VisitAggExpr(const Expr *E, const MemRegion *Dest,
  61                                 ExplodedNode *Pred, ExplodedNodeSet &Dst) {
  62   AggExprVisitor(Dest, Pred, Dst, *this).Visit(const_cast<Expr *>(E));
  63 }