Esempio n. 1
0
void TDDataStructures::ComputePostOrder(const Function &F,
                                        DenseSet<DSGraph*> &Visited,
                                        std::vector<DSGraph*> &PostOrder) {
  if (F.isDeclaration()) return;
  DSGraph* G = getOrCreateGraph(&F);
  if (!Visited.insert(G).second) return;

  // Recursively traverse all of the callee graphs.
  svset<const Function*> Callees;

  // Go through all of the callsites in this graph and find all callees
  // Here we're trying to capture all possible callees so that we can ensure
  // each function has all possible callers inlined into it.
  for (DSGraph::fc_iterator CI = G->fc_begin(), E = G->fc_end();
       CI != E; ++CI) {
    // Direct calls are easy, no reason to look at DSCallGraph
    // or anything to do with SCC's
    if (CI->isDirectCall()) {
      ComputePostOrder(*CI->getCalleeFunc(), Visited, PostOrder);
    }
    else {
      // Otherwise, ask the DSCallGraph for the full set of possible
      // callees for this callsite.
      // This includes all members of the SCC's of those callees,
      // and well as others in F's SCC, since we must assume
      // any indirect call might be intra-SCC.
      callgraph.addFullFunctionSet(CI->getCallSite(), Callees);
    }
  }

  for (svset<const Function*>::iterator I = Callees.begin(),
       E = Callees.end(); I != E; ++I)
    ComputePostOrder(**I, Visited, PostOrder);

  PostOrder.push_back(G);
}
Esempio n. 2
0
/// InlineCallersIntoGraph - Inline all of the callers of the specified DS graph
/// into it, then recompute completeness of nodes in the resultant graph.
void TDDataStructures::InlineCallersIntoGraph(DSGraph* DSG) {
  // Inline caller graphs into this graph.  First step, get the list of call
  // sites that call into this graph.
  std::vector<CallerCallEdge> EdgesFromCaller;
  std::map<DSGraph*, std::vector<CallerCallEdge> >::iterator
    CEI = CallerEdges.find(DSG);
  if (CEI != CallerEdges.end()) {
    std::swap(CEI->second, EdgesFromCaller);
    CallerEdges.erase(CEI);
  }

  // Sort the caller sites to provide a by-caller-graph ordering.
  std::sort(EdgesFromCaller.begin(), EdgesFromCaller.end());


  // Merge information from the globals graph into this graph.  FIXME: This is
  // stupid.  Instead of us cloning information from the GG into this graph,
  // then having RemoveDeadNodes clone it back, we should do all of this as a
  // post-pass over all of the graphs.  We need to take cloning out of
  // removeDeadNodes and gut removeDeadNodes at the same time first though. :(
  cloneGlobalsInto(DSG, DSGraph::DontCloneCallNodes |
                        DSGraph::DontCloneAuxCallNodes);

  DEBUG(errs() << "[TD] Inlining callers into '"
        << DSG->getFunctionNames() << "'\n");

  DSG->maskIncompleteMarkers();
  // Iteratively inline caller graphs into this graph.
  while (!EdgesFromCaller.empty()) {
    DSGraph* CallerGraph = EdgesFromCaller.back().CallerGraph;

    // Iterate through all of the call sites of this graph, cloning and merging
    // any nodes required by the call.
    ReachabilityCloner RC(DSG, CallerGraph,
                          DSGraph::DontCloneCallNodes |
                          DSGraph::DontCloneAuxCallNodes);

    // Inline all call sites from this caller graph.
    do {
      const DSCallSite &CS = *EdgesFromCaller.back().CS;
      const Function &CF = *EdgesFromCaller.back().CalledFunction;
      DEBUG(errs() << "   [TD] Inlining graph into Fn '"
            << CF.getName().str() << "' from ");
      if (CallerGraph->getReturnNodes().empty()) {
        DEBUG(errs() << "SYNTHESIZED INDIRECT GRAPH");
      } else {
        DEBUG(errs() << "Fn '" << CS.getCallSite().getInstruction()->
              getParent()->getParent()->getName().str() << "'");
      }
      DEBUG(errs() << ": " << CF.getFunctionType()->getNumParams()
            << " args\n");

      // Get the formal argument and return nodes for the called function and
      // merge them with the cloned subgraph.
      DSCallSite T1 = DSG->getCallSiteForArguments(CF);
      RC.mergeCallSite(T1, CS);
      ++NumTDInlines;

      EdgesFromCaller.pop_back();
    } while (!EdgesFromCaller.empty() &&
             EdgesFromCaller.back().CallerGraph == CallerGraph);
  }



  // Next, now that this graph is finalized, we need to recompute the
  // incompleteness markers for this graph and remove unreachable nodes.

  // If any of the functions is externally callable, treat everything in its
  // SCC as externally callable.
  bool isExternallyCallable = false;
  for (DSGraph::retnodes_iterator I = DSG->retnodes_begin(),
         E = DSG->retnodes_end(); I != E; ++I)
    if (ExternallyCallable.count(I->first)) {
      isExternallyCallable = true;
      break;
    }

  // Recompute the Incomplete markers.  Depends on whether args are complete
  unsigned IncFlags = DSGraph::IgnoreFormalArgs;
  IncFlags |= DSGraph::IgnoreGlobals | DSGraph::MarkVAStart;
  DSG->markIncompleteNodes(IncFlags);

  // If this graph contains functions that are externally callable, now is the time to mark
  // their arguments and return values as external.  At this point TD is inlining all caller information,
  // and that means External callers too.
  unsigned ExtFlags
    = isExternallyCallable ? DSGraph::MarkFormalsExternal : DSGraph::DontMarkFormalsExternal;
  DSG->computeExternalFlags(ExtFlags);
  DSG->computeIntPtrFlags();

  cloneIntoGlobals(DSG, DSGraph::DontCloneCallNodes |
                        DSGraph::DontCloneAuxCallNodes);
  //
  // Delete dead nodes.  Treat globals that are unreachable as dead also.
  //
  // FIXME:
  //  Do not delete unreachable globals as the comment describes.  For its
  //  alignment checks on the results of load instructions, SAFECode must be
  //  able to find the DSNode of both the result of the load as well as the
  //  pointer dereferenced by the load.  If we remove unreachable globals, then
  //  if the dereferenced pointer is a global, its DSNode will not reachable
  //  from the local graph's scalar map, and chaos ensues.
  //
  //  So, for now, just remove dead nodes but leave the globals alone.
  //
  DSG->removeDeadNodes(0);

  // We are done with computing the current TD Graph!  Finally, before we can
  // finish processing this function, we figure out which functions it calls and
  // records these call graph edges, so that we have them when we process the
  // callee graphs.
  if (DSG->fc_begin() == DSG->fc_end()) return;

  // Loop over all the call sites and all the callees at each call site, and add
  // edges to the CallerEdges structure for each callee.
  for (DSGraph::fc_iterator CI = DSG->fc_begin(), E = DSG->fc_end();
       CI != E; ++CI) {

    // Handle direct calls efficiently.
    if (CI->isDirectCall()) {
      if (!CI->getCalleeFunc()->isDeclaration() &&
          !DSG->getReturnNodes().count(CI->getCalleeFunc()))
        CallerEdges[getOrCreateGraph(CI->getCalleeFunc())]
          .push_back(CallerCallEdge(DSG, &*CI, CI->getCalleeFunc()));
      continue;
    }

    svset<const Function*> AllCallees;
    std::vector<const Function*> Callees;

    // Get the list of callees
    callgraph.addFullFunctionSet(CI->getCallSite(), AllCallees);

    // Filter all non-declarations, and calls within this DSGraph
    for (svset<const Function*>::iterator I = AllCallees.begin(),
        E = AllCallees.end(); I != E; ++I) {
      const Function *F = *I;
      if (!F->isDeclaration() && getDSGraph(**I) != DSG)
        Callees.push_back(F);
    }
    AllCallees.clear();

    // If there is exactly one callee from this call site, remember the edge in
    // CallerEdges.
    if (Callees.size() == 1) {
      const Function * Callee = Callees[0];
      CallerEdges[getOrCreateGraph(Callee)]
          .push_back(CallerCallEdge(DSG, &*CI, Callee));
    }
    if (Callees.size() <= 1) continue;

    // Otherwise, there are multiple callees from this call site, so it must be
    // an indirect call.  Chances are that there will be other call sites with
    // this set of targets.  If so, we don't want to do M*N inlining operations,
    // so we build up a new, private, graph that represents the calls of all
    // calls to this set of functions.

    std::map<std::vector<const Function*>, DSGraph*>::iterator IndCallRecI =
      IndCallMap.lower_bound(Callees);

    // If we already have this graph, recycle it.
    if (IndCallRecI != IndCallMap.end() && IndCallRecI->first == Callees) {
      DEBUG(errs() << "  [TD] *** Reuse of indcall graph for " << Callees.size()
            << " callees!\n");
      DSGraph * IndCallGraph = IndCallRecI->second;
      assert(IndCallGraph->getFunctionCalls().size() == 1);

      // Merge the call into the CS already in the IndCallGraph
      ReachabilityCloner RC(IndCallGraph, DSG, 0);
      RC.mergeCallSite(IndCallGraph->getFunctionCalls().front(), *CI);
    } else {
      // Otherwise, create a new DSGraph to represent this.
      DSGraph* IndCallGraph = new DSGraph(DSG->getGlobalECs(),
                                          DSG->getDataLayout(), *TypeSS);

      // Clone over the call into the new DSGraph
      ReachabilityCloner RC(IndCallGraph, DSG, 0);
      DSCallSite ClonedCS = RC.cloneCallSite(*CI);

      // Add the cloned CS to the graph, as if it were an original call.
      IndCallGraph->getFunctionCalls().push_back(ClonedCS);

      // Save this graph for use later, should we need it.
      IndCallRecI = IndCallMap.insert(IndCallRecI,
                                      std::make_pair(Callees, IndCallGraph));

      // Additionally, make sure that each of the callees inlines this graph
      // exactly once.
      DSCallSite *NCS = &IndCallGraph->getFunctionCalls().front();
      for (unsigned i = 0, e = Callees.size(); i != e; ++i) {
        DSGraph* CalleeGraph = getDSGraph(*Callees[i]);
        if (CalleeGraph != DSG)
          CallerEdges[CalleeGraph].push_back(CallerCallEdge(IndCallGraph, NCS,
                                                            Callees[i]));
      }
    }
  }
}
Esempio n. 3
0
/// InlineCallersIntoGraph - Inline all of the callers of the specified DS graph
/// into it, then recompute completeness of nodes in the resultant graph.
void TDDataStructures::InlineCallersIntoGraph(DSGraph* DSG) {
  // Inline caller graphs into this graph.  First step, get the list of call
  // sites that call into this graph.
  std::vector<CallerCallEdge> EdgesFromCaller;
  std::map<DSGraph*, std::vector<CallerCallEdge> >::iterator
    CEI = CallerEdges.find(DSG);
  if (CEI != CallerEdges.end()) {
    std::swap(CEI->second, EdgesFromCaller);
    CallerEdges.erase(CEI);
  }

  // Sort the caller sites to provide a by-caller-graph ordering.
  std::sort(EdgesFromCaller.begin(), EdgesFromCaller.end());


  // Merge information from the globals graph into this graph.  FIXME: This is
  // stupid.  Instead of us cloning information from the GG into this graph,
  // then having RemoveDeadNodes clone it back, we should do all of this as a
  // post-pass over all of the graphs.  We need to take cloning out of
  // removeDeadNodes and gut removeDeadNodes at the same time first though. :(
  {
    DSGraph* GG = DSG->getGlobalsGraph();
    ReachabilityCloner RC(DSG, GG,
                          DSGraph::DontCloneCallNodes |
                          DSGraph::DontCloneAuxCallNodes);
    for (DSScalarMap::global_iterator
           GI = DSG->getScalarMap().global_begin(),
           E = DSG->getScalarMap().global_end(); GI != E; ++GI)
      RC.getClonedNH(GG->getNodeForValue(*GI));
  }

  DEBUG(errs() << "[TD] Inlining callers into '" 
	<< DSG->getFunctionNames() << "'\n");

  // Iteratively inline caller graphs into this graph.
  while (!EdgesFromCaller.empty()) {
    DSGraph* CallerGraph = EdgesFromCaller.back().CallerGraph;

    // Iterate through all of the call sites of this graph, cloning and merging
    // any nodes required by the call.
    ReachabilityCloner RC(DSG, CallerGraph,
                          DSGraph::DontCloneCallNodes |
                          DSGraph::DontCloneAuxCallNodes);

    // Inline all call sites from this caller graph.
    do {
      const DSCallSite &CS = *EdgesFromCaller.back().CS;
      const Function &CF = *EdgesFromCaller.back().CalledFunction;
      DEBUG(errs() << "   [TD] Inlining graph into Fn '" 
	    << CF.getNameStr() << "' from ");
      if (CallerGraph->getReturnNodes().empty()) {
        DEBUG(errs() << "SYNTHESIZED INDIRECT GRAPH");
      } else {
        DEBUG(errs() << "Fn '" << CS.getCallSite().getInstruction()->
	      getParent()->getParent()->getNameStr() << "'");
      }
      DEBUG(errs() << ": " << CF.getFunctionType()->getNumParams() 
	    << " args\n");

      // Get the formal argument and return nodes for the called function and
      // merge them with the cloned subgraph.
      DSCallSite T1 = DSG->getCallSiteForArguments(CF);
      RC.mergeCallSite(T1, CS);
      ++NumTDInlines;

      EdgesFromCaller.pop_back();
    } while (!EdgesFromCaller.empty() &&
             EdgesFromCaller.back().CallerGraph == CallerGraph);
  }


  {
    DSGraph* GG = DSG->getGlobalsGraph();
    ReachabilityCloner RC(GG, DSG,
                          DSGraph::DontCloneCallNodes |
                          DSGraph::DontCloneAuxCallNodes);
    for (DSScalarMap::global_iterator
           GI = DSG->getScalarMap().global_begin(),
           E = DSG->getScalarMap().global_end(); GI != E; ++GI)
      RC.getClonedNH(DSG->getNodeForValue(*GI));
  }

  // Next, now that this graph is finalized, we need to recompute the
  // incompleteness markers for this graph and remove unreachable nodes.
  DSG->maskIncompleteMarkers();

  // If any of the functions has incomplete incoming arguments, don't mark any
  // of them as complete.
  bool HasIncompleteArgs = false;
  for (DSGraph::retnodes_iterator I = DSG->retnodes_begin(),
         E = DSG->retnodes_end(); I != E; ++I)
    if (ArgsRemainIncomplete.count(I->first)) {
      HasIncompleteArgs = true;
      break;
    }

  // Recompute the Incomplete markers.  Depends on whether args are complete
  unsigned Flags
    = HasIncompleteArgs ? DSGraph::MarkFormalArgs : DSGraph::IgnoreFormalArgs;
  Flags |= DSGraph::IgnoreGlobals | DSGraph::MarkVAStart;
  DSG->markIncompleteNodes(Flags);

  // Delete dead nodes.  Treat globals that are unreachable as dead also.
  DSG->removeDeadNodes(DSGraph::RemoveUnreachableGlobals);

  // We are done with computing the current TD Graph!  Finally, before we can
  // finish processing this function, we figure out which functions it calls and
  // records these call graph edges, so that we have them when we process the
  // callee graphs.
  if (DSG->fc_begin() == DSG->fc_end()) return;

  // Loop over all the call sites and all the callees at each call site, and add
  // edges to the CallerEdges structure for each callee.
  for (DSGraph::fc_iterator CI = DSG->fc_begin(), E = DSG->fc_end();
       CI != E; ++CI) {

    // Handle direct calls efficiently.
    if (CI->isDirectCall()) {
      if (!CI->getCalleeFunc()->isDeclaration() &&
          !DSG->getReturnNodes().count(CI->getCalleeFunc()))
        CallerEdges[getOrFetchDSGraph(CI->getCalleeFunc())]
          .push_back(CallerCallEdge(DSG, &*CI, CI->getCalleeFunc()));
      continue;
    }

    Instruction *CallI = CI->getCallSite().getInstruction();
    // For each function in the invoked function list at this call site...
    calleeTy::iterator IPI =
      callee.begin(CallI), IPE = callee.end(CallI);

    // Skip over all calls to this graph (SCC calls).
    while (IPI != IPE && getDSGraph(*IPI) == DSG)
      ++IPI;

    // All SCC calls?
    if (IPI == IPE) continue;

    const Function *FirstCallee = *IPI;
    ++IPI;

    // Skip over more SCC calls.
    while (IPI != IPE && getDSGraph(*IPI) == DSG)
      ++IPI;

    // If there is exactly one callee from this call site, remember the edge in
    // CallerEdges.
    if (IPI == IPE) {
      if (!FirstCallee->isDeclaration())
        CallerEdges[getOrFetchDSGraph(FirstCallee)]
          .push_back(CallerCallEdge(DSG, &*CI, FirstCallee));
      continue;
    }

    // Otherwise, there are multiple callees from this call site, so it must be
    // an indirect call.  Chances are that there will be other call sites with
    // this set of targets.  If so, we don't want to do M*N inlining operations,
    // so we build up a new, private, graph that represents the calls of all
    // calls to this set of functions.
    std::vector<const Function*> Callees;
    for (calleeTy::iterator I = callee.begin(CallI), E = callee.end(CallI);
         I != E; ++I)
      if (!(*I)->isDeclaration())
        Callees.push_back(*I);
    std::sort(Callees.begin(), Callees.end());

    std::map<std::vector<const Function*>, DSGraph*>::iterator IndCallRecI =
      IndCallMap.lower_bound(Callees);

    DSGraph *IndCallGraph;

    // If we already have this graph, recycle it.
    if (IndCallRecI != IndCallMap.end() && IndCallRecI->first == Callees) {
      DEBUG(errs() << "  [TD] *** Reuse of indcall graph for " << Callees.size()
	    << " callees!\n");
      IndCallGraph = IndCallRecI->second;
    } else {
      // Otherwise, create a new DSGraph to represent this.
      IndCallGraph = new DSGraph(DSG->getGlobalECs(), DSG->getTargetData(), GlobalsGraph);
      // Make a nullary dummy call site, which will eventually get some content
      // merged into it.  The actual callee function doesn't matter here, so we
      // just pass it something to keep the ctor happy.
      std::vector<DSNodeHandle> ArgDummyVec;
      DSCallSite DummyCS(CI->getCallSite(), DSNodeHandle(), Callees[0]/*dummy*/,
                         ArgDummyVec);
      IndCallGraph->getFunctionCalls().push_back(DummyCS);

      IndCallRecI = IndCallMap.insert(IndCallRecI,
                                      std::make_pair(Callees, IndCallGraph));

      // Additionally, make sure that each of the callees inlines this graph
      // exactly once.
      DSCallSite *NCS = &IndCallGraph->getFunctionCalls().front();
      for (unsigned i = 0, e = Callees.size(); i != e; ++i) {
        DSGraph* CalleeGraph = getDSGraph(Callees[i]);
        if (CalleeGraph != DSG)
          CallerEdges[CalleeGraph].push_back(CallerCallEdge(IndCallGraph, NCS,
                                                            Callees[i]));
      }
    }

    // Now that we know which graph to use for this, merge the caller
    // information into the graph, based on information from the call site.
    ReachabilityCloner RC(IndCallGraph, DSG, 0);
    RC.mergeCallSite(IndCallGraph->getFunctionCalls().front(), *CI);
  }
}