C++ DSGraph::getAuxFunctionCalls方法代码示例

// run - Calculate the top down data structure graphs for each function in the
// program.
//
bool TDDataStructures::runOnModule(Module &M) {

  init(useEQBU ? &getAnalysis<EquivBUDataStructures>()
       : &getAnalysis<BUDataStructures>(),
       true, true, true, false);

  for (Module::iterator F = M.begin(); F != M.end(); ++F) {
    if (!(F->isDeclaration())){
      DSGraph *G = getOrCreateGraph(F);
      G->getAuxFunctionCalls().clear();
    }
  }
  // Figure out which functions must not mark their arguments complete because
  // they are accessible outside this compilation unit.  Currently, these
  // arguments are functions which are reachable by incomplete or external
  // nodes in the globals graph.
  const DSScalarMap &GGSM = GlobalsGraph->getScalarMap();
  DenseSet<DSNode*> Visited;
  for (DSScalarMap::global_iterator I=GGSM.global_begin(), E=GGSM.global_end();
       I != E; ++I) {
    DSNode *N = GGSM.find(*I)->second.getNode();
    if (N->isIncompleteNode() || N->isExternalNode())
      markReachableFunctionsExternallyAccessible(N, Visited);
  }

  // Loop over unresolved call nodes.  Any functions passed into (but not
  // returned!) from unresolvable call nodes may be invoked outside of the
  // current module.
  for (DSGraph::afc_iterator I = GlobalsGraph->afc_begin(),
         E = GlobalsGraph->afc_end(); I != E; ++I)
    for (unsigned arg = 0, e = I->getNumPtrArgs(); arg != e; ++arg)
      markReachableFunctionsExternallyAccessible(I->getPtrArg(arg).getNode(),
                                                 Visited);
  Visited.clear();

  // Clear Aux of Globals Graph to be refilled in later by post-TD unresolved
  // functions
  GlobalsGraph->getAuxFunctionCalls().clear();

  // Functions without internal linkage are definitely externally callable!
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration() && !I->hasInternalLinkage() && !I->hasPrivateLinkage())
      ExternallyCallable.insert(I);

  // Debug code to print the functions that are externally callable
#if 0
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (ExternallyCallable.count(I)) {
      errs() << "ExternallyCallable: " << I->getNameStr() << "\n";
    }
#endif

  // We want to traverse the call graph in reverse post-order.  To do this, we
  // calculate a post-order traversal, then reverse it.
  DenseSet<DSGraph*> VisitedGraph;
  std::vector<DSGraph*> PostOrder;

{TIME_REGION(XXX, "td:Compute postorder");

  // Calculate top-down from main...
  if (Function *F = M.getFunction("main"))
    ComputePostOrder(*F, VisitedGraph, PostOrder);

  // Next calculate the graphs for each unreachable function...
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration())
      ComputePostOrder(*I, VisitedGraph, PostOrder);

  VisitedGraph.clear();   // Release memory!
}

{TIME_REGION(XXX, "td:Inline stuff");

  // Visit each of the graphs in reverse post-order now!
  while (!PostOrder.empty()) {
    InlineCallersIntoGraph(PostOrder.back());
    PostOrder.pop_back();
  }
}

  // Free the IndCallMap.
  while (!IndCallMap.empty()) {
    delete IndCallMap.begin()->second;
    IndCallMap.erase(IndCallMap.begin());
  }

  formGlobalECs();

  ExternallyCallable.clear();
  GlobalsGraph->removeTriviallyDeadNodes();
  GlobalsGraph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
  GlobalsGraph->computeIntPtrFlags();

  // Make sure each graph has updated external information about globals
  // in the globals graph.
  VisitedGraph.clear();
  for (Module::iterator F = M.begin(); F != M.end(); ++F) {
//.........这里部分代码省略.........

static void printCollection(const Collection &C, llvm::raw_ostream &O,
                            const Module *M, const std::string &Prefix) {
  if (M == 0) {
    O << "Null Module pointer, cannot continue!\n";
    return;
  }

  unsigned TotalNumNodes = 0, TotalCallNodes = 0;
  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
    if (C.hasDSGraph(*I)) {
      DSGraph* Gr = C.getDSGraph((const Function&)*I);
      unsigned NumCalls = Gr->shouldUseAuxCalls() ?
        Gr->getAuxFunctionCalls().size() : Gr->getFunctionCalls().size();
      bool IsDuplicateGraph = false;

      //if no only print options, print everything
      bool doPrint = OnlyPrint.begin() == OnlyPrint.end();
      //otherwise check the name
      if (!doPrint)
        doPrint = OnlyPrint.end() !=
        std::find(OnlyPrint.begin(), OnlyPrint.end(), I->getName().str());

      if (doPrint) {
        const Function *SCCFn = Gr->retnodes_begin()->first;
        if (&*I == SCCFn) {
          Gr->writeGraphToFile(O, Prefix+I->getName().str());
        } else {
          IsDuplicateGraph = true; // Don't double count node/call nodes.
          O << "Didn't write '" << Prefix+I->getName().str()
            << ".dot' - Graph already emitted to '" << Prefix+SCCFn->getName().str()
            << "\n";
        }
      } else {
        const Function *SCCFn = Gr->retnodes_begin()->first;
        if (&*I == SCCFn) {
          //O << "Skipped Writing '" << Prefix+I->getName().str() << ".dot'... ["
          //  << Gr->getGraphSize() << "+" << NumCalls << "]\n";
        } else {
          IsDuplicateGraph = true; // Don't double count node/call nodes.
        }
      }

      if (!IsDuplicateGraph) {
        unsigned GraphSize = Gr->getGraphSize();
        if (MaxGraphSize < GraphSize) MaxGraphSize = GraphSize;

        TotalNumNodes += Gr->getGraphSize();
        TotalCallNodes += NumCalls;
        for (DSGraph::node_iterator NI = Gr->node_begin(), E = Gr->node_end();
             NI != E; ++NI)
          if (NI->isNodeCompletelyFolded())
            ++NumFoldedNodes;
      }
    }

  DSGraph* GG = C.getGlobalsGraph();
  TotalNumNodes  += GG->getGraphSize();
  TotalCallNodes += GG->getFunctionCalls().size();
  GG->writeGraphToFile(O, Prefix + "GlobalsGraph");

  O << "\nGraphs contain [" << TotalNumNodes << "+" << TotalCallNodes
    << "] nodes total\n";
}

//
// Method: calculateGraphs()
//
// Description:
//  Perform recursive bottom-up inlining of DSGraphs from callee to caller.
//
// Inputs:
//  F - The function which should have its callees' DSGraphs merged into its
//      own DSGraph.
//  Stack - The stack used for Tarjan's SCC-finding algorithm.
//  NextID - The nextID value used for Tarjan's SCC-finding algorithm.
//  ValMap - The map used for Tarjan's SCC-finding algorithm.
//
// Return value:
//
unsigned
BUDataStructures::calculateGraphs (const Function *F,
                                   TarjanStack & Stack,
                                   unsigned & NextID,
                                   TarjanMap & ValMap) {
  assert(!ValMap.count(F) && "Shouldn't revisit functions!");
  unsigned Min = NextID++, MyID = Min;
  ValMap[F] = Min;
  Stack.push_back(F);

  //
  // FIXME: This test should be generalized to be any function that we have
  // already processed in the case when there isn't a main() or there are
  // unreachable functions!
  //
  if (F->isDeclaration()) {   // sprintf, fprintf, sscanf, etc...
    // No callees!
    Stack.pop_back();
    ValMap[F] = ~0;
    return Min;
  }

  //
  // Get the DSGraph of the current function.  Make one if one doesn't exist.
  //
  DSGraph* Graph = getOrCreateGraph(F);

  //
  // Find all callee functions.  Use the DSGraph for this (do not use the call
  // graph (DSCallgraph) as we're still in the process of constructing it).
  //
  FuncSet CalleeFunctions;
  getAllAuxCallees(Graph, CalleeFunctions);

  //
  // Iterate through each call target (these are the edges out of the current
  // node (i.e., the current function) in Tarjan graph parlance).  Find the
  // minimum assigned ID.
  //
  for (FuncSet::iterator I = CalleeFunctions.begin(), E = CalleeFunctions.end();
       I != E; ++I) {
    const Function *Callee = *I;
    unsigned M;
    //
    // If we have not visited this callee before, visit it now (this is the
    // post-order component of the Bottom-Up algorithm).  Otherwise, look up
    // the assigned ID value from the Tarjan Value Map.
    //
    TarjanMap::iterator It = ValMap.find(Callee);
    if (It == ValMap.end())  // No, visit it now.
      M = calculateGraphs(Callee, Stack, NextID, ValMap);
    else                    // Yes, get it's number.
      M = It->second;

    //
    // If we've found a function with a smaller ID than this funtion, record
    // that ID as the minimum ID.
    //
    if (M < Min) Min = M;
  }

  assert(ValMap[F] == MyID && "SCC construction assumption wrong!");

  //
  // If the minimum ID found is not this function's ID, then this function is
  // part of a larger SCC.
  //
  if (Min != MyID)
    return Min;

  //
  // If this is a new SCC, process it now.
  //
  if (Stack.back() == F) {           // Special case the single "SCC" case here.
    DEBUG(errs() << "Visiting single node SCC #: " << MyID << " fn: "
	  << F->getName() << "\n");
    Stack.pop_back();
    DEBUG(errs() << "  [BU] Calculating graph for: " << F->getName()<< "\n");
    DSGraph* G = getOrCreateGraph(F);
    calculateGraph(G);
    DEBUG(errs() << "  [BU] Done inlining: " << F->getName() << " ["
	  << G->getGraphSize() << "+" << G->getAuxFunctionCalls().size()
	  << "]\n");

    if (MaxSCC < 1) MaxSCC = 1;
//.........这里部分代码省略.........

unsigned BUDataStructures::calculateGraphs(const Function *F,
                                           std::vector<const Function*> &Stack,
                                           unsigned &NextID,
                                           hash_map<const Function*, unsigned> &ValMap) {
  assert(!ValMap.count(F) && "Shouldn't revisit functions!");
  unsigned Min = NextID++, MyID = Min;
  ValMap[F] = Min;
  Stack.push_back(F);

  // FIXME!  This test should be generalized to be any function that we have
  // already processed, in the case when there isn't a main or there are
  // unreachable functions!
  if (F->isDeclaration()) {   // sprintf, fprintf, sscanf, etc...
    // No callees!
    Stack.pop_back();
    ValMap[F] = ~0;
    return Min;
  }

  DSGraph* Graph = getOrFetchDSGraph(F);

  // Find all callee functions.
  std::vector<const Function*> CalleeFunctions;
  GetAllAuxCallees(Graph, CalleeFunctions);
  std::sort(CalleeFunctions.begin(), CalleeFunctions.end());
  std::vector<const Function*>::iterator uid = std::unique(CalleeFunctions.begin(), CalleeFunctions.end());
  CalleeFunctions.resize(uid - CalleeFunctions.begin());

  // The edges out of the current node are the call site targets...
  for (unsigned i = 0, e = CalleeFunctions.size(); i != e; ++i) {
    const Function *Callee = CalleeFunctions[i];
    unsigned M;
    // Have we visited the destination function yet?
    hash_map<const Function*, unsigned>::iterator It = ValMap.find(Callee);
    if (It == ValMap.end())  // No, visit it now.
      M = calculateGraphs(Callee, Stack, NextID, ValMap);
    else                    // Yes, get it's number.
      M = It->second;
    if (M < Min) Min = M;
  }

  assert(ValMap[F] == MyID && "SCC construction assumption wrong!");
  if (Min != MyID)
    return Min;         // This is part of a larger SCC!

  // If this is a new SCC, process it now.
  if (Stack.back() == F) {           // Special case the single "SCC" case here.
    DEBUG(errs() << "Visiting single node SCC #: " << MyID << " fn: "
	  << F->getName() << "\n");
    Stack.pop_back();
    DEBUG(errs() << "  [BU] Calculating graph for: " << F->getName()<< "\n");
    calculateGraph(Graph);
    DEBUG(errs() << "  [BU] Done inlining: " << F->getName() << " ["
	  << Graph->getGraphSize() << "+" << Graph->getAuxFunctionCalls().size()
	  << "]\n");

    if (MaxSCC < 1) MaxSCC = 1;

    // Should we revisit the graph?  Only do it if there are now new resolvable
    // callees or new callees
    GetAllAuxCallees(Graph, CalleeFunctions);
    if (CalleeFunctions.size()) {
      DEBUG(errs() << "Recalculating " << F->getName() << " due to new knowledge\n");
      ValMap.erase(F);
      return calculateGraphs(F, Stack, NextID, ValMap);
    } else {
      ValMap[F] = ~0U;
      return MyID;
    }
  } else {
    // SCCFunctions - Keep track of the functions in the current SCC
    //
    std::vector<DSGraph*> SCCGraphs;

    unsigned SCCSize = 1;
    const Function *NF = Stack.back();
    ValMap[NF] = ~0U;
    DSGraph* SCCGraph = getDSGraph(NF);

    // First thing first, collapse all of the DSGraphs into a single graph for
    // the entire SCC.  Splice all of the graphs into one and discard all of the
    // old graphs.
    //
    while (NF != F) {
      Stack.pop_back();
      NF = Stack.back();
      ValMap[NF] = ~0U;

      DSGraph* NFG = getDSGraph(NF);

      if (NFG != SCCGraph) {
        // Update the Function -> DSG map.
        for (DSGraph::retnodes_iterator I = NFG->retnodes_begin(),
               E = NFG->retnodes_end(); I != E; ++I)
          setDSGraph(I->first, SCCGraph);
        
        SCCGraph->spliceFrom(NFG);
        delete NFG;
        ++SCCSize;
      }
//.........这里部分代码省略.........