C++ ExplodedNode::pred_empty方法代码示例

void UndefBranchChecker::checkBranchCondition(const Stmt *Condition,
                                              BranchNodeBuilder &Builder,
                                              ExprEngine &Eng) const {
  const GRState *state = Builder.getState();
  SVal X = state->getSVal(Condition);
  if (X.isUndef()) {
    ExplodedNode *N = Builder.generateNode(state, true);
    if (N) {
      N->markAsSink();
      if (!BT)
        BT.reset(
               new BuiltinBug("Branch condition evaluates to a garbage value"));

      // What's going on here: we want to highlight the subexpression of the
      // condition that is the most likely source of the "uninitialized
      // branch condition."  We do a recursive walk of the condition's
      // subexpressions and roughly look for the most nested subexpression
      // that binds to Undefined.  We then highlight that expression's range.
      BlockEdge B = cast<BlockEdge>(N->getLocation());
      const Expr* Ex = cast<Expr>(B.getSrc()->getTerminatorCondition());
      assert (Ex && "Block must have a terminator.");

      // Get the predecessor node and check if is a PostStmt with the Stmt
      // being the terminator condition.  We want to inspect the state
      // of that node instead because it will contain main information about
      // the subexpressions.
      assert (!N->pred_empty());

      // Note: any predecessor will do.  They should have identical state,
      // since all the BlockEdge did was act as an error sink since the value
      // had to already be undefined.
      ExplodedNode *PrevN = *N->pred_begin();
      ProgramPoint P = PrevN->getLocation();
      const GRState* St = N->getState();

      if (PostStmt* PS = dyn_cast<PostStmt>(&P))
        if (PS->getStmt() == Ex)
          St = PrevN->getState();

      FindUndefExpr FindIt(Eng.getStateManager(), St);
      Ex = FindIt.FindExpr(Ex);

      // Emit the bug report.
      EnhancedBugReport *R = new EnhancedBugReport(*BT, BT->getDescription(),N);
      R->addVisitorCreator(bugreporter::registerTrackNullOrUndefValue, Ex);
      R->addRange(Ex->getSourceRange());

      Eng.getBugReporter().EmitReport(R);
    }

    Builder.markInfeasible(true);
    Builder.markInfeasible(false);
  }
}

void UndefBranchChecker::checkBranchCondition(const Stmt *Condition,
                                              CheckerContext &Ctx) const {
  SVal X = Ctx.getState()->getSVal(Condition, Ctx.getLocationContext());
  if (X.isUndef()) {
    // Generate a sink node, which implicitly marks both outgoing branches as
    // infeasible.
    ExplodedNode *N = Ctx.generateSink();
    if (N) {
      if (!BT)
        BT.reset(new BuiltinBug(
            this, "Branch condition evaluates to a garbage value"));

      // What's going on here: we want to highlight the subexpression of the
      // condition that is the most likely source of the "uninitialized
      // branch condition."  We do a recursive walk of the condition's
      // subexpressions and roughly look for the most nested subexpression
      // that binds to Undefined.  We then highlight that expression's range.

      // Get the predecessor node and check if is a PostStmt with the Stmt
      // being the terminator condition.  We want to inspect the state
      // of that node instead because it will contain main information about
      // the subexpressions.

      // Note: any predecessor will do.  They should have identical state,
      // since all the BlockEdge did was act as an error sink since the value
      // had to already be undefined.
      assert (!N->pred_empty());
      const Expr *Ex = cast<Expr>(Condition);
      ExplodedNode *PrevN = *N->pred_begin();
      ProgramPoint P = PrevN->getLocation();
      ProgramStateRef St = N->getState();

      if (Optional<PostStmt> PS = P.getAs<PostStmt>())
        if (PS->getStmt() == Ex)
          St = PrevN->getState();

      FindUndefExpr FindIt(St, Ctx.getLocationContext());
      Ex = FindIt.FindExpr(Ex);

      // Emit the bug report.
      BugReport *R = new BugReport(*BT, BT->getDescription(), N);
      bugreporter::trackNullOrUndefValue(N, Ex, *R);
      R->addRange(Ex->getSourceRange());

      Ctx.emitReport(R);
    }
  }
}