1 files changed, 374 insertions, 0 deletions
diff --git a/lib/CodeGen/WinEHPrepare.cpp b/lib/CodeGen/WinEHPrepare.cpp
index 7246e1cf3ea5..c2b3d84ca363 100644
--- a/lib/CodeGen/WinEHPrepare.cpp
+++ b/lib/CodeGen/WinEHPrepare.cpp
@@ -2480,3 +2480,377 @@ void llvm::parseEHActions(
   }
   std::reverse(Actions.begin(), Actions.end());
 }
+
+namespace {
+struct WinEHNumbering {
+  WinEHNumbering(WinEHFuncInfo &FuncInfo) : FuncInfo(FuncInfo),
+      CurrentBaseState(-1), NextState(0) {}
+
+  WinEHFuncInfo &FuncInfo;
+  int CurrentBaseState;
+  int NextState;
+
+  SmallVector<std::unique_ptr<ActionHandler>, 4> HandlerStack;
+  SmallPtrSet<const Function *, 4> VisitedHandlers;
+
+  int currentEHNumber() const {
+    return HandlerStack.empty() ? CurrentBaseState : HandlerStack.back()->getEHState();
+  }
+
+  void createUnwindMapEntry(int ToState, ActionHandler *AH);
+  void createTryBlockMapEntry(int TryLow, int TryHigh,
+                              ArrayRef<CatchHandler *> Handlers);
+  void processCallSite(MutableArrayRef<std::unique_ptr<ActionHandler>> Actions,
+                       ImmutableCallSite CS);
+  void popUnmatchedActions(int FirstMismatch);
+  void calculateStateNumbers(const Function &F);
+  void findActionRootLPads(const Function &F);
+};
+}
+
+void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
+  WinEHUnwindMapEntry UME;
+  UME.ToState = ToState;
+  if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
+    UME.Cleanup = cast<Function>(CH->getHandlerBlockOrFunc());
+  else
+    UME.Cleanup = nullptr;
+  FuncInfo.UnwindMap.push_back(UME);
+}
+
+void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
+                                            ArrayRef<CatchHandler *> Handlers) {
+  // See if we already have an entry for this set of handlers.
+  // This is using iterators rather than a range-based for loop because
+  // if we find the entry we're looking for we'll need the iterator to erase it.
+  int NumHandlers = Handlers.size();
+  auto I = FuncInfo.TryBlockMap.begin();
+  auto E = FuncInfo.TryBlockMap.end();
+  for ( ; I != E; ++I) {
+    auto &Entry = *I;
+    if (Entry.HandlerArray.size() != (size_t)NumHandlers)
+      continue;
+    int N;
+    for (N = 0; N < NumHandlers; ++N) {
+      if (Entry.HandlerArray[N].Handler != Handlers[N]->getHandlerBlockOrFunc())
+        break; // breaks out of inner loop
+    }
+    // If all the handlers match, this is what we were looking for.
+    if (N == NumHandlers) {
+      break;
+    }
+  }
+
+  // If we found an existing entry for this set of handlers, extend the range
+  // but move the entry to the end of the map vector.  The order of entries
+  // in the map is critical to the way that the runtime finds handlers.
+  // FIXME: Depending on what has happened with block ordering, this may
+  //        incorrectly combine entries that should remain separate.
+  if (I != E) {
+    // Copy the existing entry.
+    WinEHTryBlockMapEntry Entry = *I;
+    Entry.TryLow = std::min(TryLow, Entry.TryLow);
+    Entry.TryHigh = std::max(TryHigh, Entry.TryHigh);
+    assert(Entry.TryLow <= Entry.TryHigh);
+    // Erase the old entry and add this one to the back.
+    FuncInfo.TryBlockMap.erase(I);
+    FuncInfo.TryBlockMap.push_back(Entry);
+    return;
+  }
+
+  // If we didn't find an entry, create a new one.
+  WinEHTryBlockMapEntry TBME;
+  TBME.TryLow = TryLow;
+  TBME.TryHigh = TryHigh;
+  assert(TBME.TryLow <= TBME.TryHigh);
+  for (CatchHandler *CH : Handlers) {
+    WinEHHandlerType HT;
+    if (CH->getSelector()->isNullValue()) {
+      HT.Adjectives = 0x40;
+      HT.TypeDescriptor = nullptr;
+    } else {
+      auto *GV = cast<GlobalVariable>(CH->getSelector()->stripPointerCasts());
+      // Selectors are always pointers to GlobalVariables with 'struct' type.
+      // The struct has two fields, adjectives and a type descriptor.
+      auto *CS = cast<ConstantStruct>(GV->getInitializer());
+      HT.Adjectives =
+          cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
+      HT.TypeDescriptor =
+          cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
+    }
+    HT.Handler = cast<Function>(CH->getHandlerBlockOrFunc());
+    HT.CatchObjRecoverIdx = CH->getExceptionVarIndex();
+    TBME.HandlerArray.push_back(HT);
+  }
+  FuncInfo.TryBlockMap.push_back(TBME);
+}
+
+static void print_name(const Value *V) {
+#ifndef NDEBUG
+  if (!V) {
+    DEBUG(dbgs() << "null");
+    return;
+  }
+
+  if (const auto *F = dyn_cast<Function>(V))
+    DEBUG(dbgs() << F->getName());
+  else
+    DEBUG(V->dump());
+#endif
+}
+
+void WinEHNumbering::processCallSite(
+    MutableArrayRef<std::unique_ptr<ActionHandler>> Actions,
+    ImmutableCallSite CS) {
+  DEBUG(dbgs() << "processCallSite (EH state = " << currentEHNumber()
+               << ") for: ");
+  print_name(CS ? CS.getCalledValue() : nullptr);
+  DEBUG(dbgs() << '\n');
+
+  DEBUG(dbgs() << "HandlerStack: \n");
+  for (int I = 0, E = HandlerStack.size(); I < E; ++I) {
+    DEBUG(dbgs() << "  ");
+    print_name(HandlerStack[I]->getHandlerBlockOrFunc());
+    DEBUG(dbgs() << '\n');
+  }
+  DEBUG(dbgs() << "Actions: \n");
+  for (int I = 0, E = Actions.size(); I < E; ++I) {
+    DEBUG(dbgs() << "  ");
+    print_name(Actions[I]->getHandlerBlockOrFunc());
+    DEBUG(dbgs() << '\n');
+  }
+  int FirstMismatch = 0;
+  for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E;
+       ++FirstMismatch) {
+    if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() !=
+        Actions[FirstMismatch]->getHandlerBlockOrFunc())
+      break;
+  }
+
+  // Remove unmatched actions from the stack and process their EH states.
+  popUnmatchedActions(FirstMismatch);
+
+  DEBUG(dbgs() << "Pushing actions for CallSite: ");
+  print_name(CS ? CS.getCalledValue() : nullptr);
+  DEBUG(dbgs() << '\n');
+
+  bool LastActionWasCatch = false;
+  const LandingPadInst *LastRootLPad = nullptr;
+  for (size_t I = FirstMismatch; I != Actions.size(); ++I) {
+    // We can reuse eh states when pushing two catches for the same invoke.
+    bool CurrActionIsCatch = isa<CatchHandler>(Actions[I].get());
+    auto *Handler = cast<Function>(Actions[I]->getHandlerBlockOrFunc());
+    // Various conditions can lead to a handler being popped from the
+    // stack and re-pushed later.  That shouldn't create a new state.
+    // FIXME: Can code optimization lead to re-used handlers?
+    if (FuncInfo.HandlerEnclosedState.count(Handler)) {
+      // If we already assigned the state enclosed by this handler re-use it.
+      Actions[I]->setEHState(FuncInfo.HandlerEnclosedState[Handler]);
+      continue;
+    }
+    const LandingPadInst* RootLPad = FuncInfo.RootLPad[Handler];
+    if (CurrActionIsCatch && LastActionWasCatch && RootLPad == LastRootLPad) {
+      DEBUG(dbgs() << "setEHState for handler to " << currentEHNumber() << "\n");
+      Actions[I]->setEHState(currentEHNumber());
+    } else {
+      DEBUG(dbgs() << "createUnwindMapEntry(" << currentEHNumber() << ", ");
+      print_name(Actions[I]->getHandlerBlockOrFunc());
+      DEBUG(dbgs() << ") with EH state " << NextState << "\n");
+      createUnwindMapEntry(currentEHNumber(), Actions[I].get());
+      DEBUG(dbgs() << "setEHState for handler to " << NextState << "\n");
+      Actions[I]->setEHState(NextState);
+      NextState++;
+    }
+    HandlerStack.push_back(std::move(Actions[I]));
+    LastActionWasCatch = CurrActionIsCatch;
+    LastRootLPad = RootLPad;
+  }
+
+  // This is used to defer numbering states for a handler until after the
+  // last time it appears in an invoke action list.
+  if (CS.isInvoke()) {
+    for (int I = 0, E = HandlerStack.size(); I < E; ++I) {
+      auto *Handler = cast<Function>(HandlerStack[I]->getHandlerBlockOrFunc());
+      if (FuncInfo.LastInvoke[Handler] != cast<InvokeInst>(CS.getInstruction()))
+        continue;
+      FuncInfo.LastInvokeVisited[Handler] = true;
+      DEBUG(dbgs() << "Last invoke of ");
+      print_name(Handler);
+      DEBUG(dbgs() << " has been visited.\n");
+    }
+  }
+
+  DEBUG(dbgs() << "In EHState " << currentEHNumber() << " for CallSite: ");
+  print_name(CS ? CS.getCalledValue() : nullptr);
+  DEBUG(dbgs() << '\n');
+}
+
+void WinEHNumbering::popUnmatchedActions(int FirstMismatch) {
+  // Don't recurse while we are looping over the handler stack.  Instead, defer
+  // the numbering of the catch handlers until we are done popping.
+  SmallVector<CatchHandler *, 4> PoppedCatches;
+  for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) {
+    std::unique_ptr<ActionHandler> Handler = HandlerStack.pop_back_val();
+    if (isa<CatchHandler>(Handler.get()))
+      PoppedCatches.push_back(cast<CatchHandler>(Handler.release()));
+  }
+
+  int TryHigh = NextState - 1;
+  int LastTryLowIdx = 0;
+  for (int I = 0, E = PoppedCatches.size(); I != E; ++I) {
+    CatchHandler *CH = PoppedCatches[I];
+    DEBUG(dbgs() << "Popped handler with state " << CH->getEHState() << "\n");
+    if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) {
+      int TryLow = CH->getEHState();
+      auto Handlers =
+          makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1);
+      DEBUG(dbgs() << "createTryBlockMapEntry(" << TryLow << ", " << TryHigh);
+      for (size_t J = 0; J < Handlers.size(); ++J) {
+        DEBUG(dbgs() << ", ");
+        print_name(Handlers[J]->getHandlerBlockOrFunc());
+      }
+      DEBUG(dbgs() << ")\n");
+      createTryBlockMapEntry(TryLow, TryHigh, Handlers);
+      LastTryLowIdx = I + 1;
+    }
+  }
+
+  for (CatchHandler *CH : PoppedCatches) {
+    if (auto *F = dyn_cast<Function>(CH->getHandlerBlockOrFunc())) {
+      if (FuncInfo.LastInvokeVisited[F]) {
+        DEBUG(dbgs() << "Assigning base state " << NextState << " to ");
+        print_name(F);
+        DEBUG(dbgs() << '\n');
+        FuncInfo.HandlerBaseState[F] = NextState;
+        DEBUG(dbgs() << "createUnwindMapEntry(" << currentEHNumber()
+                     << ", null)\n");
+        createUnwindMapEntry(currentEHNumber(), nullptr);
+        ++NextState;
+        calculateStateNumbers(*F);
+      }
+      else {
+        DEBUG(dbgs() << "Deferring handling of ");
+        print_name(F);
+        DEBUG(dbgs() << " until last invoke visited.\n");
+      }
+    }
+    delete CH;
+  }
+}
+
+void WinEHNumbering::calculateStateNumbers(const Function &F) {
+  auto I = VisitedHandlers.insert(&F);
+  if (!I.second)
+    return; // We've already visited this handler, don't renumber it.
+
+  int OldBaseState = CurrentBaseState;
+  if (FuncInfo.HandlerBaseState.count(&F)) {
+    CurrentBaseState = FuncInfo.HandlerBaseState[&F];
+  }
+
+  size_t SavedHandlerStackSize = HandlerStack.size();
+
+  DEBUG(dbgs() << "Calculating state numbers for: " << F.getName() << '\n');
+  SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
+  for (const BasicBlock &BB : F) {
+    for (const Instruction &I : BB) {
+      const auto *CI = dyn_cast<CallInst>(&I);
+      if (!CI || CI->doesNotThrow())
+        continue;
+      processCallSite(None, CI);
+    }
+    const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
+    if (!II)
+      continue;
+    const LandingPadInst *LPI = II->getLandingPadInst();
+    auto *ActionsCall = dyn_cast<IntrinsicInst>(LPI->getNextNode());
+    if (!ActionsCall)
+      continue;
+    assert(ActionsCall->getIntrinsicID() == Intrinsic::eh_actions);
+    parseEHActions(ActionsCall, ActionList);
+    if (ActionList.empty())
+      continue;
+    processCallSite(ActionList, II);
+    ActionList.clear();
+    FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
+    DEBUG(dbgs() << "Assigning state " << currentEHNumber()
+                  << " to landing pad at " << LPI->getParent()->getName()
+                  << '\n');
+  }
+
+  // Pop any actions that were pushed on the stack for this function.
+  popUnmatchedActions(SavedHandlerStackSize);
+
+  DEBUG(dbgs() << "Assigning max state " << NextState - 1
+               << " to " << F.getName() << '\n');
+  FuncInfo.CatchHandlerMaxState[&F] = NextState - 1;
+
+  CurrentBaseState = OldBaseState;
+}
+
+// This function follows the same basic traversal as calculateStateNumbers
+// but it is necessary to identify the root landing pad associated
+// with each action before we start assigning state numbers.
+void WinEHNumbering::findActionRootLPads(const Function &F) {
+  auto I = VisitedHandlers.insert(&F);
+  if (!I.second)
+    return; // We've already visited this handler, don't revisit it.
+
+  SmallVector<std::unique_ptr<ActionHandler>, 4> ActionList;
+  for (const BasicBlock &BB : F) {
+    const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
+    if (!II)
+      continue;
+    const LandingPadInst *LPI = II->getLandingPadInst();
+    auto *ActionsCall = dyn_cast<IntrinsicInst>(LPI->getNextNode());
+    if (!ActionsCall)
+      continue;
+
+    assert(ActionsCall->getIntrinsicID() == Intrinsic::eh_actions);
+    parseEHActions(ActionsCall, ActionList);
+    if (ActionList.empty())
+      continue;
+    for (int I = 0, E = ActionList.size(); I < E; ++I) {
+      if (auto *Handler
+              = dyn_cast<Function>(ActionList[I]->getHandlerBlockOrFunc())) {
+        FuncInfo.LastInvoke[Handler] = II;
+        // Don't replace the root landing pad if we previously saw this
+        // handler in a different function.
+        if (FuncInfo.RootLPad.count(Handler) &&
+            FuncInfo.RootLPad[Handler]->getParent()->getParent() != &F)
+          continue;
+        DEBUG(dbgs() << "Setting root lpad for ");
+        print_name(Handler);
+        DEBUG(dbgs() << " to " << LPI->getParent()->getName() << '\n');
+        FuncInfo.RootLPad[Handler] = LPI;
+      }
+    }
+    // Walk the actions again and look for nested handlers.  This has to
+    // happen after all of the actions have been processed in the current
+    // function.
+    for (int I = 0, E = ActionList.size(); I < E; ++I)
+      if (auto *Handler
+              = dyn_cast<Function>(ActionList[I]->getHandlerBlockOrFunc()))
+        findActionRootLPads(*Handler);
+    ActionList.clear();
+  }
+}
+
+void llvm::calculateWinCXXEHStateNumbers(const Function *ParentFn,
+                                         WinEHFuncInfo &FuncInfo) {
+  // Return if it's already been done.
+  if (!FuncInfo.LandingPadStateMap.empty())
+    return;
+
+  WinEHNumbering Num(FuncInfo);
+  Num.findActionRootLPads(*ParentFn);
+  // The VisitedHandlers list is used by both findActionRootLPads and
+  // calculateStateNumbers, but both functions need to visit all handlers.
+  Num.VisitedHandlers.clear();
+  Num.calculateStateNumbers(*ParentFn);
+  // Pop everything on the handler stack.
+  // It may be necessary to call this more than once because a handler can
+  // be pushed on the stack as a result of clearing the stack.
+  while (!Num.HandlerStack.empty())
+    Num.processCallSite(None, ImmutableCallSite());
+}