lib/Checker/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/GR/PathSensitive/GRExprEngine.h"
  16 #include "clang/AST/StmtVisitor.h"
  17
  18 using namespace clang;
  19
  20 namespace {
  21 /// AggExprVisitor is designed after AggExprEmitter of the CodeGen module.  It
  22 /// is used for evaluating exprs of C++ object type. Evaluating such exprs
  23 /// requires a destination pointer pointing to the object being evaluated
  24 /// into. Passing such a pointer around would pollute the Visit* interface of
  25 /// GRExprEngine. AggExprVisitor encapsulates code that goes through various
  26 /// cast and construct exprs (and others), and at the final point, dispatches
  27 /// back to the GRExprEngine to let the real evaluation logic happen.
  28 class AggExprVisitor : public StmtVisitor<AggExprVisitor> {
  29   const MemRegion *Dest;
  30   ExplodedNode *Pred;
  31   ExplodedNodeSet &DstSet;
  32   GRExprEngine &Eng;
  33
  34 public:
  35   AggExprVisitor(const MemRegion *dest, ExplodedNode *N, ExplodedNodeSet &dst,
  36                  GRExprEngine &eng)
  37     : Dest(dest), Pred(N), DstSet(dst), Eng(eng) {}
  38
  39   void VisitCastExpr(CastExpr *E);
  40   void VisitCXXConstructExpr(CXXConstructExpr *E);
  41 };
  42 }
  43
  44 void AggExprVisitor::VisitCastExpr(CastExpr *E) {
  45   switch (E->getCastKind()) {
  46   default:
  47     assert(0 && "Unhandled cast kind");
  48   case CK_NoOp:
  49   case CK_ConstructorConversion:
  50     Visit(E->getSubExpr());
  51     break;
  52   }
  53 }
  54
  55 void AggExprVisitor::VisitCXXConstructExpr(CXXConstructExpr *E) {
  56   Eng.VisitCXXConstructExpr(E, Dest, Pred, DstSet);
  57 }
  58
  59 void GRExprEngine::VisitAggExpr(const Expr *E, const MemRegion *Dest,
  60                                 ExplodedNode *Pred, ExplodedNodeSet &Dst) {
  61   AggExprVisitor(Dest, Pred, Dst, *this).Visit(const_cast<Expr *>(E));
  62 }