C++ ProgramPoint::getLocationContext方法代码示例

PathDiagnosticLocation
  PathDiagnosticLocation::create(const ProgramPoint& P,
                                 const SourceManager &SMng) {

  const Stmt* S = 0;
  if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
    const CFGBlock *BSrc = BE->getSrc();
    S = BSrc->getTerminatorCondition();
  }
  else if (const StmtPoint *SP = dyn_cast<StmtPoint>(&P)) {
    S = SP->getStmt();
    if (isa<PostStmtPurgeDeadSymbols>(P))
      return PathDiagnosticLocation::createEnd(S, SMng, P.getLocationContext());
  }
  else if (const PostImplicitCall *PIE = dyn_cast<PostImplicitCall>(&P)) {
    return PathDiagnosticLocation(PIE->getLocation(), SMng);
  }
  else if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) {
    return getLocationForCaller(CE->getCalleeContext(),
                                CE->getLocationContext(),
                                SMng);
  }
  else if (const CallExitEnd *CEE = dyn_cast<CallExitEnd>(&P)) {
    return getLocationForCaller(CEE->getCalleeContext(),
                                CEE->getLocationContext(),
                                SMng);
  }
  else {
    llvm_unreachable("Unexpected ProgramPoint");
  }

  return PathDiagnosticLocation(S, SMng, P.getLocationContext());
}

PathDiagnosticLocation
  PathDiagnosticLocation::create(const ProgramPoint& P,
                                 const SourceManager &SMng) {

  const Stmt* S = 0;
  if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
    const CFGBlock *BSrc = BE->getSrc();
    S = BSrc->getTerminatorCondition();
  } else if (Optional<StmtPoint> SP = P.getAs<StmtPoint>()) {
    S = SP->getStmt();
    if (P.getAs<PostStmtPurgeDeadSymbols>())
      return PathDiagnosticLocation::createEnd(S, SMng, P.getLocationContext());
  } else if (Optional<PostInitializer> PIP = P.getAs<PostInitializer>()) {
    return PathDiagnosticLocation(PIP->getInitializer()->getSourceLocation(),
                                  SMng);
  } else if (Optional<PostImplicitCall> PIE = P.getAs<PostImplicitCall>()) {
    return PathDiagnosticLocation(PIE->getLocation(), SMng);
  } else if (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
    return getLocationForCaller(CE->getCalleeContext(),
                                CE->getLocationContext(),
                                SMng);
  } else if (Optional<CallExitEnd> CEE = P.getAs<CallExitEnd>()) {
    return getLocationForCaller(CEE->getCalleeContext(),
                                CEE->getLocationContext(),
                                SMng);
  } else {
    llvm_unreachable("Unexpected ProgramPoint");
  }

  return PathDiagnosticLocation(S, SMng, P.getLocationContext());
}

PathDiagnosticLocation
  PathDiagnosticLocation::create(const ProgramPoint& P,
                                 const SourceManager &SMng) {

  const Stmt* S = 0;
  if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
    const CFGBlock *BSrc = BE->getSrc();
    S = BSrc->getTerminatorCondition();
  }
  else if (const PostStmt *PS = dyn_cast<PostStmt>(&P)) {
    S = PS->getStmt();
  }
  else if (const PostImplicitCall *PIE = dyn_cast<PostImplicitCall>(&P)) {
    return PathDiagnosticLocation(PIE->getLocation(), SMng);
  }
  else if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) {
    return getLocationForCaller(CE->getCalleeContext(),
                                CE->getLocationContext(),
                                SMng);
  }
  else if (const CallExitEnd *CEE = dyn_cast<CallExitEnd>(&P)) {
    return getLocationForCaller(CEE->getCalleeContext(),
                                CEE->getLocationContext(),
                                SMng);
  }

  return PathDiagnosticLocation(S, SMng, P.getLocationContext());
}

PathDiagnosticLocation
PathDiagnosticLocation::create(const ProgramPoint& P,
                               const SourceManager &SMng) {
  const Stmt* S = nullptr;
  if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) {
    const CFGBlock *BSrc = BE->getSrc();
    S = BSrc->getTerminatorCondition();
  } else if (Optional<StmtPoint> SP = P.getAs<StmtPoint>()) {
    S = SP->getStmt();
    if (P.getAs<PostStmtPurgeDeadSymbols>())
      return PathDiagnosticLocation::createEnd(S, SMng, P.getLocationContext());
  } else if (Optional<PostInitializer> PIP = P.getAs<PostInitializer>()) {
    return PathDiagnosticLocation(PIP->getInitializer()->getSourceLocation(),
                                  SMng);
  } else if (Optional<PreImplicitCall> PIC = P.getAs<PreImplicitCall>()) {
    return PathDiagnosticLocation(PIC->getLocation(), SMng);
  } else if (Optional<PostImplicitCall> PIE = P.getAs<PostImplicitCall>()) {
    return PathDiagnosticLocation(PIE->getLocation(), SMng);
  } else if (Optional<CallEnter> CE = P.getAs<CallEnter>()) {
    return getLocationForCaller(CE->getCalleeContext(),
                                CE->getLocationContext(),
                                SMng);
  } else if (Optional<CallExitEnd> CEE = P.getAs<CallExitEnd>()) {
    return getLocationForCaller(CEE->getCalleeContext(),
                                CEE->getLocationContext(),
                                SMng);
  } else if (auto CEB = P.getAs<CallExitBegin>()) {
    if (const ReturnStmt *RS = CEB->getReturnStmt())
      return PathDiagnosticLocation::createBegin(RS, SMng,
                                                 CEB->getLocationContext());
    return PathDiagnosticLocation(
        CEB->getLocationContext()->getDecl()->getSourceRange().getEnd(), SMng);
  } else if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) {
    CFGElement BlockFront = BE->getBlock()->front();
    if (auto StmtElt = BlockFront.getAs<CFGStmt>()) {
      return PathDiagnosticLocation(StmtElt->getStmt()->getBeginLoc(), SMng);
    } else if (auto NewAllocElt = BlockFront.getAs<CFGNewAllocator>()) {
      return PathDiagnosticLocation(
          NewAllocElt->getAllocatorExpr()->getBeginLoc(), SMng);
    }
    llvm_unreachable("Unexpected CFG element at front of block");
  } else {
    llvm_unreachable("Unexpected ProgramPoint");
  }

  return PathDiagnosticLocation(S, SMng, P.getLocationContext());
}

PathDiagnosticLocation
  PathDiagnosticLocation::create(const ProgramPoint& P,
                                 const SourceManager &SMng) {

  const Stmt* S = 0;
  if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
    const CFGBlock *BSrc = BE->getSrc();
    S = BSrc->getTerminatorCondition();
  }
  else if (const PostStmt *PS = dyn_cast<PostStmt>(&P)) {
    S = PS->getStmt();
  }

  return PathDiagnosticLocation(S, SMng, P.getLocationContext());
}

PathDiagnosticLocation
  PathDiagnosticLocation::createEndOfPath(const ExplodedNode* N,
                                          const SourceManager &SM) {
  assert(N && "Cannot create a location with a null node.");

  const ExplodedNode *NI = N;

  while (NI) {
    ProgramPoint P = NI->getLocation();
    const LocationContext *LC = P.getLocationContext();
    if (const StmtPoint *PS = dyn_cast<StmtPoint>(&P))
      return PathDiagnosticLocation(PS->getStmt(), SM, LC);
    else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) {
      const Stmt *Term = BE->getSrc()->getTerminator();
      assert(Term);
      return PathDiagnosticLocation(Term, SM, LC);
    }
    NI = NI->succ_empty() ? 0 : *(NI->succ_begin());
  }

  return createDeclEnd(N->getLocationContext(), SM);
}

bool ExplodedGraph::shouldCollect(const ExplodedNode *node) {
  // Reclaim all nodes that match *all* the following criteria:
  //
  // (1) 1 predecessor (that has one successor)
  // (2) 1 successor (that has one predecessor)
  // (3) The ProgramPoint is for a PostStmt.
  // (4) There is no 'tag' for the ProgramPoint.
  // (5) The 'store' is the same as the predecessor.
  // (6) The 'GDM' is the same as the predecessor.
  // (7) The LocationContext is the same as the predecessor.
  // (8) The PostStmt isn't for a non-consumed Stmt or Expr.
  // (9) The successor is not a CallExpr StmtPoint (so that we would be able to
  //     find it when retrying a call with no inlining).
  // FIXME: It may be safe to reclaim PreCall and PostCall nodes as well.

  // Conditions 1 and 2.
  if (node->pred_size() != 1 || node->succ_size() != 1)
    return false;

  const ExplodedNode *pred = *(node->pred_begin());
  if (pred->succ_size() != 1)
    return false;
  
  const ExplodedNode *succ = *(node->succ_begin());
  if (succ->pred_size() != 1)
    return false;

  // Condition 3.
  ProgramPoint progPoint = node->getLocation();
  if (!isa<PostStmt>(progPoint))
    return false;

  // Condition 4.
  PostStmt ps = cast<PostStmt>(progPoint);
  if (ps.getTag())
    return false;

  // Conditions 5, 6, and 7.
  ProgramStateRef state = node->getState();
  ProgramStateRef pred_state = pred->getState();    
  if (state->store != pred_state->store || state->GDM != pred_state->GDM ||
      progPoint.getLocationContext() != pred->getLocationContext())
    return false;
  
  // Condition 8.
  // Do not collect nodes for non-consumed Stmt or Expr to ensure precise
  // diagnostic generation; specifically, so that we could anchor arrows
  // pointing to the beginning of statements (as written in code).
  if (!isa<Expr>(ps.getStmt()))
    return false;
  
  if (const Expr *Ex = dyn_cast<Expr>(ps.getStmt())) {
    ParentMap &PM = progPoint.getLocationContext()->getParentMap();
    if (!PM.isConsumedExpr(Ex))
      return false;
  }
  
  // Condition 9.
  const ProgramPoint SuccLoc = succ->getLocation();
  if (const StmtPoint *SP = dyn_cast<StmtPoint>(&SuccLoc))
    if (CallEvent::isCallStmt(SP->getStmt()))
      return false;

  return true;
}

void ExplodedGraph::reclaimRecentlyAllocatedNodes() {
  if (!recentlyAllocatedNodes)
    return;
  NodeList &nl = *getNodeList(recentlyAllocatedNodes);
 
  // Reclaimn all nodes that match *all* the following criteria:
  //
  // (1) 1 predecessor (that has one successor)
  // (2) 1 successor (that has one predecessor)
  // (3) The ProgramPoint is for a PostStmt.
  // (4) There is no 'tag' for the ProgramPoint.
  // (5) The 'store' is the same as the predecessor.
  // (6) The 'GDM' is the same as the predecessor.
  // (7) The LocationContext is the same as the predecessor.
  // (8) The PostStmt is for a non-CFGElement expression.
  
  for (NodeList::iterator i = nl.begin(), e = nl.end() ; i != e; ++i) {
    ExplodedNode *node = *i;
    
    // Conditions 1 and 2.
    if (node->pred_size() != 1 || node->succ_size() != 1)
      continue;

    ExplodedNode *pred = *(node->pred_begin());
    if (pred->succ_size() != 1)
      continue;

    ExplodedNode *succ = *(node->succ_begin());
    if (succ->pred_size() != 1)
      continue;

    // Condition 3.
    ProgramPoint progPoint = node->getLocation();
    if (!isa<PostStmt>(progPoint))
      continue;
    // Condition 4.
    PostStmt ps = cast<PostStmt>(progPoint);
    if (ps.getTag())
      continue;

    if (isa<BinaryOperator>(ps.getStmt()))
      continue;

    // Conditions 5, 6, and 7.
    const ProgramState *state = node->getState();
    const ProgramState *pred_state = pred->getState();    
    if (state->store != pred_state->store || state->GDM != pred_state->GDM ||
        progPoint.getLocationContext() != pred->getLocationContext())
      continue;

    // Condition 8.
    if (node->getCFG().isBlkExpr(ps.getStmt()))
      continue;
    
    // If we reach here, we can remove the node.  This means:
    // (a) changing the predecessors successor to the successor of this node
    // (b) changing the successors predecessor to the predecessor of this node
    // (c) Putting 'node' onto freeNodes.
    pred->replaceSuccessor(succ);
    succ->replacePredecessor(pred);
    if (!freeNodes)
      freeNodes = new NodeList();
    getNodeList(freeNodes)->push_back(node);
    Nodes.RemoveNode(node);
    --NumNodes;
    node->~ExplodedNode();
  }
  
  nl.clear();
}

//.........这里部分代码省略.........
  // If we have an expression that provided the value, try to track where it
  // came from.
  if (InitE) {
    if (V.isUndef() || V.getAs<loc::ConcreteInt>()) {
      if (!IsParam)
        InitE = InitE->IgnoreParenCasts();
      bugreporter::trackNullOrUndefValue(StoreSite, InitE, BR, IsParam);
    } else {
      ReturnVisitor::addVisitorIfNecessary(StoreSite, InitE->IgnoreParenCasts(),
                                           BR);
    }
  }

  if (!R->canPrintPretty())
    return 0;

  // Okay, we've found the binding. Emit an appropriate message.
  SmallString<256> sbuf;
  llvm::raw_svector_ostream os(sbuf);

  if (Optional<PostStmt> PS = StoreSite->getLocationAs<PostStmt>()) {
    const Stmt *S = PS->getStmt();
    const char *action = 0;
    const DeclStmt *DS = dyn_cast<DeclStmt>(S);
    const VarRegion *VR = dyn_cast<VarRegion>(R);

    if (DS) {
      action = "initialized to ";
    } else if (isa<BlockExpr>(S)) {
      action = "captured by block as ";
      if (VR) {
        // See if we can get the BlockVarRegion.
        ProgramStateRef State = StoreSite->getState();
        SVal V = State->getSVal(S, PS->getLocationContext());
        if (const BlockDataRegion *BDR =
              dyn_cast_or_null<BlockDataRegion>(V.getAsRegion())) {
          if (const VarRegion *OriginalR = BDR->getOriginalRegion(VR)) {
            if (Optional<KnownSVal> KV =
                State->getSVal(OriginalR).getAs<KnownSVal>())
              BR.addVisitor(new FindLastStoreBRVisitor(*KV, OriginalR));
          }
        }
      }
    }

    if (action) {
      if (!R)
        return 0;

      os << '\'';
      R->printPretty(os);
      os << "' ";

      if (V.getAs<loc::ConcreteInt>()) {
        bool b = false;
        if (R->isBoundable()) {
          if (const TypedValueRegion *TR = dyn_cast<TypedValueRegion>(R)) {
            if (TR->getValueType()->isObjCObjectPointerType()) {
              os << action << "nil";
              b = true;
            }
          }
        }

        if (!b)
          os << action << "a null pointer value";

bool ExplodedGraph::shouldCollect(const ExplodedNode *node) {
  // First, we only consider nodes for reclamation of the following
  // conditions apply:
  //
  // (1) 1 predecessor (that has one successor)
  // (2) 1 successor (that has one predecessor)
  //
  // If a node has no successor it is on the "frontier", while a node
  // with no predecessor is a root.
  //
  // After these prerequisites, we discard all "filler" nodes that
  // are used only for intermediate processing, and are not essential
  // for analyzer history:
  //
  // (a) PreStmtPurgeDeadSymbols
  //
  // We then discard all other nodes where *all* of the following conditions
  // apply:
  //
  // (3) The ProgramPoint is for a PostStmt, but not a PostStore.
  // (4) There is no 'tag' for the ProgramPoint.
  // (5) The 'store' is the same as the predecessor.
  // (6) The 'GDM' is the same as the predecessor.
  // (7) The LocationContext is the same as the predecessor.
  // (8) Expressions that are *not* lvalue expressions.
  // (9) The PostStmt isn't for a non-consumed Stmt or Expr.
  // (10) The successor is neither a CallExpr StmtPoint nor a CallEnter or 
  //      PreImplicitCall (so that we would be able to find it when retrying a 
  //      call with no inlining).
  // FIXME: It may be safe to reclaim PreCall and PostCall nodes as well.

  // Conditions 1 and 2.
  if (node->pred_size() != 1 || node->succ_size() != 1)
    return false;

  const ExplodedNode *pred = *(node->pred_begin());
  if (pred->succ_size() != 1)
    return false;
  
  const ExplodedNode *succ = *(node->succ_begin());
  if (succ->pred_size() != 1)
    return false;

  // Now reclaim any nodes that are (by definition) not essential to
  // analysis history and are not consulted by any client code.
  ProgramPoint progPoint = node->getLocation();
  if (progPoint.getAs<PreStmtPurgeDeadSymbols>())
    return !progPoint.getTag();

  // Condition 3.
  if (!progPoint.getAs<PostStmt>() || progPoint.getAs<PostStore>())
    return false;

  // Condition 4.
  if (progPoint.getTag())
    return false;

  // Conditions 5, 6, and 7.
  ProgramStateRef state = node->getState();
  ProgramStateRef pred_state = pred->getState();    
  if (state->store != pred_state->store || state->GDM != pred_state->GDM ||
      progPoint.getLocationContext() != pred->getLocationContext())
    return false;

  // All further checks require expressions. As per #3, we know that we have
  // a PostStmt.
  const Expr *Ex = dyn_cast<Expr>(progPoint.castAs<PostStmt>().getStmt());
  if (!Ex)
    return false;

  // Condition 8.
  // Do not collect nodes for "interesting" lvalue expressions since they are
  // used extensively for generating path diagnostics.
  if (isInterestingLValueExpr(Ex))
    return false;

  // Condition 9.
  // Do not collect nodes for non-consumed Stmt or Expr to ensure precise
  // diagnostic generation; specifically, so that we could anchor arrows
  // pointing to the beginning of statements (as written in code).
  ParentMap &PM = progPoint.getLocationContext()->getParentMap();
  if (!PM.isConsumedExpr(Ex))
    return false;

  // Condition 10.
  const ProgramPoint SuccLoc = succ->getLocation();
  if (Optional<StmtPoint> SP = SuccLoc.getAs<StmtPoint>())
    if (CallEvent::isCallStmt(SP->getStmt()))
      return false;

  // Condition 10, continuation.
  if (SuccLoc.getAs<CallEnter>() || SuccLoc.getAs<PreImplicitCall>())
    return false;

  return true;
}