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

// BU:
// Construct the callgraph from the local graphs
// Find SCCs
// inline bottom up
//
bool BUDataStructures::runOnModuleInternal(Module& M) {

  //
  // Make sure we have a DSGraph for all declared functions in the Module.
  // While we may not need them in this DSA pass, a later DSA pass may ask us
  // for their DSGraphs, and we want to have them if asked.
  //
  for (Function &F : M) {
    if (!(F.isDeclaration())){
      getOrCreateGraph(&F);
    }
  }

  //
  // Do a post-order traversal of the SCC callgraph and do bottom-up inlining.
  //
  postOrderInline (M);

  // At the end of the bottom-up pass, the globals graph becomes complete.
  // FIXME: This is not the right way to do this, but it is sorta better than
  // nothing!  In particular, externally visible globals and unresolvable call
  // nodes at the end of the BU phase should make things that they point to
  // incomplete in the globals graph.
  //

  GlobalsGraph->removeTriviallyDeadNodes();
  GlobalsGraph->maskIncompleteMarkers();

  // Mark external globals incomplete.
  GlobalsGraph->markIncompleteNodes(DSGraph::IgnoreGlobals);
  GlobalsGraph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
  GlobalsGraph->computeIntPtrFlags();

  //
  // Create equivalence classes for aliasing globals so that we only need to
  // record one global per DSNode.
  //
  formGlobalECs();

  // Merge the globals variables (not the calls) from the globals graph back
  // into the individual function's graph so that changes made to globals during
  // BU can be reflected. This is specifically needed for correct call graph
  //
  for (Function &F : M) {
    if (!(F.isDeclaration())){
      DSGraph *Graph  = getOrCreateGraph(&F);
      cloneGlobalsInto(Graph, DSGraph::DontCloneCallNodes |
                        DSGraph::DontCloneAuxCallNodes);
      Graph->buildCallGraph(callgraph, GlobalFunctionList, filterCallees);
      Graph->maskIncompleteMarkers();
      Graph->markIncompleteNodes(DSGraph::MarkFormalArgs |
                                   DSGraph::IgnoreGlobals);
      Graph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
      Graph->computeIntPtrFlags();
    }
  }

  // Once the correct flags have been calculated. Update the callgraph.
  for (Function &F : M) {
    if (!(F.isDeclaration())){
      DSGraph *Graph = getOrCreateGraph(&F);
      Graph->buildCompleteCallGraph(callgraph,
                                    GlobalFunctionList, filterCallees);
    }
  }

  NumCallEdges += callgraph.size();

  // Put the call graph in canonical form
  callgraph.buildSCCs();
  callgraph.buildRoots();

  DEBUG(print(errs(), &M));
  return false;
}

bool
StdLibDataStructures::runOnModule (Module &M) {
  //
  // Get the results from the local pass.
  //
  init (&getAnalysis<LocalDataStructures>(), true, true, false, false);
  AllocWrappersAnalysis = &getAnalysis<AllocIdentify>();

  //
  // Fetch the DSGraphs for all defined functions within the module.
  //
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 
    if (!I->isDeclaration())
      getOrCreateGraph(&*I);

  //
  // Erase direct calls to functions that don't return a pointer and are marked
  // with the readnone annotation.
  //
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 
    if (I->isDeclaration() && I->doesNotAccessMemory() &&
        !isa<PointerType>(I->getReturnType()))
      eraseCallsTo(I);

  //
  // Erase direct calls to external functions that are not varargs, do not
  // return a pointer, and do not take pointers.
  //
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) 
    if (I->isDeclaration() && !I->isVarArg() &&
        !isa<PointerType>(I->getReturnType())) {
      bool hasPtr = false;
      for (Function::arg_iterator ii = I->arg_begin(), ee = I->arg_end();
           ii != ee;
           ++ii)
        if (isa<PointerType>(ii->getType())) {
          hasPtr = true;
          break;
        }
      if (!hasPtr)
        eraseCallsTo(I);
    }

  if(!DisableStdLib) {

    //
    // Scan through the function summaries and process functions by summary.
    //
    for (int x = 0; recFuncs[x].name; ++x) 
      if (Function* F = M.getFunction(recFuncs[x].name))
        if (F->isDeclaration()) {
          processFunction(x, F);
        }

    std::set<std::string>::iterator ai = AllocWrappersAnalysis->alloc_begin();
    std::set<std::string>::iterator ae = AllocWrappersAnalysis->alloc_end();
    int x;
    for (x = 0; recFuncs[x].name; ++x) {
      if(recFuncs[x].name == std::string("malloc"))
        break;
    }

    for(;ai != ae; ++ai) {
      if(Function* F = M.getFunction(*ai))
        processFunction(x, F);
    }

    ai = AllocWrappersAnalysis->dealloc_begin();
    ae = AllocWrappersAnalysis->dealloc_end();
    for (x = 0; recFuncs[x].name; ++x) {
      if(recFuncs[x].name == std::string("free"))
        break;
    }

    for(;ai != ae; ++ai) {
      if(Function* F = M.getFunction(*ai))
        processFunction(x, F);
    }

    //
    // Merge return values and checked pointer values for SAFECode run-time
    // checks.
    //
    processRuntimeCheck (M, "boundscheck", 2);
    processRuntimeCheck (M, "boundscheckui", 2);
    processRuntimeCheck (M, "exactcheck2", 1);

    processRuntimeCheck (M, "boundscheck_debug", 2);
    processRuntimeCheck (M, "boundscheckui_debug", 2);
    processRuntimeCheck (M, "exactcheck2_debug", 1);

    processRuntimeCheck (M, "pchk_getActualValue", 1);
  }

  //
  // In the Local DSA Pass, we marked nodes passed to/returned from 'StdLib'
  // functions as External because, at that point, they were.  However, they no
  // longer are necessarily External, and we need to update accordingly.
  //
  GlobalsGraph->maskIncompleteMarkers();
//.........这里部分代码省略.........

//
// Method: postOrderInline()
//
// Description:
//  This methods does a post order traversal of the call graph and performs
//  bottom-up inlining of the DSGraphs.
//
void
BUDataStructures::postOrderInline (Module & M) {
  // Variables used for Tarjan SCC-finding algorithm.  These are passed into
  // the recursive function used to find SCCs.
  std::vector<const Function*> Stack;
  std::map<const Function*, unsigned> ValMap;
  unsigned NextID = 1;


  // Do post order traversal on the global ctors. Use this information to update
  // the globals graph.
  const char *Name = "llvm.global_ctors";
  GlobalVariable *GV = M.getNamedGlobal(Name);
  if (GV && !(GV->isDeclaration()) && !(GV->hasLocalLinkage())) {
    // Should be an array of '{ int, void ()* }' structs.  The first value is
    // the init priority, which we ignore.
    ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
    if (InitList) {
      for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
        if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))) {
          if (CS->getNumOperands() != 2)
            break; // Not array of 2-element structs.
          Constant *FP = CS->getOperand(1);
          if (FP->isNullValue())
            break;  // Found a null terminator, exit.

          if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
            if (CE->isCast())
              FP = CE->getOperand(0);
          Function *F = dyn_cast<Function>(FP);
          if (F && !F->isDeclaration() && !ValMap.count(F)) {
            calculateGraphs(F, Stack, NextID, ValMap);
            CloneAuxIntoGlobal(getDSGraph(*F));
          }
        }
      GlobalsGraph->removeTriviallyDeadNodes();
      GlobalsGraph->maskIncompleteMarkers();

      // Mark external globals incomplete.
      GlobalsGraph->markIncompleteNodes(DSGraph::IgnoreGlobals);
      GlobalsGraph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
      GlobalsGraph->computeIntPtrFlags();

      //
      // Create equivalence classes for aliasing globals so that we only need to
      // record one global per DSNode.
      //
      formGlobalECs();
      // propogte information calculated
      // from the globals graph to the other graphs.
      for (Module::iterator F = M.begin(); F != M.end(); ++F) {
        if (!(F->isDeclaration())){
          DSGraph *Graph  = getDSGraph(*F);
          cloneGlobalsInto(Graph, DSGraph::DontCloneCallNodes |
                           DSGraph::DontCloneAuxCallNodes);
          Graph->buildCallGraph(callgraph, GlobalFunctionList, filterCallees);
          Graph->maskIncompleteMarkers();
          Graph->markIncompleteNodes(DSGraph::MarkFormalArgs |
                                     DSGraph::IgnoreGlobals);
          Graph->computeExternalFlags(DSGraph::DontMarkFormalsExternal);
          Graph->computeIntPtrFlags();
        }
      }
    }
  }

  //
  // Start the post order traversal with the main() function.  If there is no
  // main() function, don't worry; we'll have a separate traversal for inlining
  // graphs for functions not reachable from main().
  //
  Function *MainFunc = M.getFunction ("main");
  if (MainFunc && !MainFunc->isDeclaration()) {
    calculateGraphs(MainFunc, Stack, NextID, ValMap);
    CloneAuxIntoGlobal(getDSGraph(*MainFunc));
  }

  //
  // Calculate the graphs for any functions that are unreachable from main...
  //
  for (Function &F : M)
    if (!F.isDeclaration() && !ValMap.count(&F)) {
      if (MainFunc)
        DEBUG(errs() << debugname << ": Function unreachable from main: "
        << F.getName() << "\n");
      calculateGraphs(&F, Stack, NextID, ValMap);     // Calculate all graphs.
      CloneAuxIntoGlobal(getDSGraph(F));

      // Mark this graph as processed.  Do this by finding all functions
      // in the graph that map to it, and mark them visited.
      // Note that this really should be handled neatly by calculateGraphs
      // itself, not here.  However this catches the worst offenders.
      DSGraph *G = getDSGraph(F);
//.........这里部分代码省略.........

bool BUDataStructures::runOnModuleInternal(Module& M) {
  std::vector<const Function*> Stack;
  hash_map<const Function*, unsigned> ValMap;
  unsigned NextID = 1;

  Function *MainFunc = M.getFunction("main");
  if (MainFunc && !MainFunc->isDeclaration()) {
    calculateGraphs(MainFunc, Stack, NextID, ValMap);
    CloneAuxIntoGlobal(getDSGraph(MainFunc));
  } else {
    DEBUG(errs() << debugname << ": No 'main' function found!\n");
  }

  // Calculate the graphs for any functions that are unreachable from main...
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration() && !hasDSGraph(I)) {
      if (MainFunc)
        DEBUG(errs() << debugname << ": Function unreachable from main: "
	      << I->getName() << "\n");
      calculateGraphs(I, Stack, NextID, ValMap);     // Calculate all graphs.
      CloneAuxIntoGlobal(getDSGraph(I));
    }

  // If we computed any temporary indcallgraphs, free them now.
  for (std::map<std::vector<const Function*>,
         std::pair<DSGraph*, std::vector<DSNodeHandle> > >::iterator I =
         IndCallGraphMap.begin(), E = IndCallGraphMap.end(); I != E; ++I) {
    I->second.second.clear();  // Drop arg refs into the graph.
    delete I->second.first;
  }
  IndCallGraphMap.clear();

  // At the end of the bottom-up pass, the globals graph becomes complete.
  // FIXME: This is not the right way to do this, but it is sorta better than
  // nothing!  In particular, externally visible globals and unresolvable call
  // nodes at the end of the BU phase should make things that they point to
  // incomplete in the globals graph.
  //

  finalizeGlobals();

  GlobalsGraph->removeTriviallyDeadNodes(true);
  GlobalsGraph->maskIncompleteMarkers();

  // Mark external globals incomplete.
  GlobalsGraph->markIncompleteNodes(DSGraph::IgnoreGlobals);

  formGlobalECs();

  // Merge the globals variables (not the calls) from the globals graph back
  // into the main function's graph so that the main function contains all of
  // the information about global pools and GV usage in the program.
  if (MainFunc && !MainFunc->isDeclaration()) {
    DSGraph* MainGraph = getDSGraph(MainFunc);
    const DSGraph* GG = MainGraph->getGlobalsGraph();
    ReachabilityCloner RC(MainGraph, GG,
                          DSGraph::DontCloneCallNodes |
                          DSGraph::DontCloneAuxCallNodes);

    // Clone the global nodes into this graph.
    for (DSScalarMap::global_iterator I = GG->getScalarMap().global_begin(),
           E = GG->getScalarMap().global_end(); I != E; ++I)
      if (isa<GlobalVariable>(*I))
        RC.getClonedNH(GG->getNodeForValue(*I));

    MainGraph->maskIncompleteMarkers();
    MainGraph->markIncompleteNodes(DSGraph::MarkFormalArgs |
                                   DSGraph::IgnoreGlobals);
  }

  NumCallEdges += callee.size();

  return false;
}