Move all the cleanups framework code into a single file.

Pure motion.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124484 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 0 insertions, 886 deletions

diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 3923816a18..2a1024d2e8 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -28,10 +28,6 @@
 using namespace clang;
 using namespace CodeGen;
 
-static void ResolveAllBranchFixups(CodeGenFunction &CGF,
-                                   llvm::SwitchInst *Switch,
-                                   llvm::BasicBlock *CleanupEntry);
-
 CodeGenFunction::CodeGenFunction(CodeGenModule &cgm)
   : BlockFunction(cgm, *this, Builder), CGM(cgm),
     Target(CGM.getContext().Target),
@@ -692,888 +688,6 @@ llvm::Value* CodeGenFunction::EmitVAListRef(const Expr* E) {
   return EmitLValue(E).getAddress();
 }
 
-/// Pops cleanup blocks until the given savepoint is reached.
-void CodeGenFunction::PopCleanupBlocks(EHScopeStack::stable_iterator Old) {
-  assert(Old.isValid());
-
-  while (EHStack.stable_begin() != Old) {
-    EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin());
-
-    // As long as Old strictly encloses the scope's enclosing normal
-    // cleanup, we're going to emit another normal cleanup which
-    // fallthrough can propagate through.
-    bool FallThroughIsBranchThrough =
-      Old.strictlyEncloses(Scope.getEnclosingNormalCleanup());
-
-    PopCleanupBlock(FallThroughIsBranchThrough);
-  }
-}
-
-static llvm::BasicBlock *CreateNormalEntry(CodeGenFunction &CGF,
-                                           EHCleanupScope &Scope) {
-  assert(Scope.isNormalCleanup());
-  llvm::BasicBlock *Entry = Scope.getNormalBlock();
-  if (!Entry) {
-    Entry = CGF.createBasicBlock("cleanup");
-    Scope.setNormalBlock(Entry);
-  }
-  return Entry;
-}
-
-static llvm::BasicBlock *CreateEHEntry(CodeGenFunction &CGF,
-                                       EHCleanupScope &Scope) {
-  assert(Scope.isEHCleanup());
-  llvm::BasicBlock *Entry = Scope.getEHBlock();
-  if (!Entry) {
-    Entry = CGF.createBasicBlock("eh.cleanup");
-    Scope.setEHBlock(Entry);
-  }
-  return Entry;
-}
-
-/// Transitions the terminator of the given exit-block of a cleanup to
-/// be a cleanup switch.
-static llvm::SwitchInst *TransitionToCleanupSwitch(CodeGenFunction &CGF,
-                                                   llvm::BasicBlock *Block) {
-  // If it's a branch, turn it into a switch whose default
-  // destination is its original target.
-  llvm::TerminatorInst *Term = Block->getTerminator();
-  assert(Term && "can't transition block without terminator");
-
-  if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) {
-    assert(Br->isUnconditional());
-    llvm::LoadInst *Load =
-      new llvm::LoadInst(CGF.getNormalCleanupDestSlot(), "cleanup.dest", Term);
-    llvm::SwitchInst *Switch =
-      llvm::SwitchInst::Create(Load, Br->getSuccessor(0), 4, Block);
-    Br->eraseFromParent();
-    return Switch;
-  } else {
-    return cast<llvm::SwitchInst>(Term);
-  }
-}
-
-/// Attempts to reduce a cleanup's entry block to a fallthrough.  This
-/// is basically llvm::MergeBlockIntoPredecessor, except
-/// simplified/optimized for the tighter constraints on cleanup blocks.
-///
-/// Returns the new block, whatever it is.
-static llvm::BasicBlock *SimplifyCleanupEntry(CodeGenFunction &CGF,
-                                              llvm::BasicBlock *Entry) {
-  llvm::BasicBlock *Pred = Entry->getSinglePredecessor();
-  if (!Pred) return Entry;
-
-  llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Pred->getTerminator());
-  if (!Br || Br->isConditional()) return Entry;
-  assert(Br->getSuccessor(0) == Entry);
-
-  // If we were previously inserting at the end of the cleanup entry
-  // block, we'll need to continue inserting at the end of the
-  // predecessor.
-  bool WasInsertBlock = CGF.Builder.GetInsertBlock() == Entry;
-  assert(!WasInsertBlock || CGF.Builder.GetInsertPoint() == Entry->end());
-
-  // Kill the branch.
-  Br->eraseFromParent();
-
-  // Merge the blocks.
-  Pred->getInstList().splice(Pred->end(), Entry->getInstList());
-
-  // Replace all uses of the entry with the predecessor, in case there
-  // are phis in the cleanup.
-  Entry->replaceAllUsesWith(Pred);
-
-  // Kill the entry block.
-  Entry->eraseFromParent();
-
-  if (WasInsertBlock)
-    CGF.Builder.SetInsertPoint(Pred);
-
-  return Pred;
-}
-
-static void EmitCleanup(CodeGenFunction &CGF,
-                        EHScopeStack::Cleanup *Fn,
-                        bool ForEH,
-                        llvm::Value *ActiveFlag) {
-  // EH cleanups always occur within a terminate scope.
-  if (ForEH) CGF.EHStack.pushTerminate();
-
-  // If there's an active flag, load it and skip the cleanup if it's
-  // false.
-  llvm::BasicBlock *ContBB = 0;
-  if (ActiveFlag) {
-    ContBB = CGF.createBasicBlock("cleanup.done");
-    llvm::BasicBlock *CleanupBB = CGF.createBasicBlock("cleanup.action");
-    llvm::Value *IsActive
-      = CGF.Builder.CreateLoad(ActiveFlag, "cleanup.is_active");
-    CGF.Builder.CreateCondBr(IsActive, CleanupBB, ContBB);
-    CGF.EmitBlock(CleanupBB);
-  }
-
-  // Ask the cleanup to emit itself.
-  Fn->Emit(CGF, ForEH);
-  assert(CGF.HaveInsertPoint() && "cleanup ended with no insertion point?");
-
-  // Emit the continuation block if there was an active flag.
-  if (ActiveFlag)
-    CGF.EmitBlock(ContBB);
-
-  // Leave the terminate scope.
-  if (ForEH) CGF.EHStack.popTerminate();
-}
-
-static void ForwardPrebranchedFallthrough(llvm::BasicBlock *Exit,
-                                          llvm::BasicBlock *From,
-                                          llvm::BasicBlock *To) {
-  // Exit is the exit block of a cleanup, so it always terminates in
-  // an unconditional branch or a switch.
-  llvm::TerminatorInst *Term = Exit->getTerminator();
-
-  if (llvm::BranchInst *Br = dyn_cast<llvm::BranchInst>(Term)) {
-    assert(Br->isUnconditional() && Br->getSuccessor(0) == From);
-    Br->setSuccessor(0, To);
-  } else {
-    llvm::SwitchInst *Switch = cast<llvm::SwitchInst>(Term);
-    for (unsigned I = 0, E = Switch->getNumSuccessors(); I != E; ++I)
-      if (Switch->getSuccessor(I) == From)
-        Switch->setSuccessor(I, To);
-  }
-}
-
-/// Pops a cleanup block.  If the block includes a normal cleanup, the
-/// current insertion point is threaded through the cleanup, as are
-/// any branch fixups on the cleanup.
-void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
-  assert(!EHStack.empty() && "cleanup stack is empty!");
-  assert(isa<EHCleanupScope>(*EHStack.begin()) && "top not a cleanup!");
-  EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.begin());
-  assert(Scope.getFixupDepth() <= EHStack.getNumBranchFixups());
-
-  // Remember activation information.
-  bool IsActive = Scope.isActive();
-  llvm::Value *NormalActiveFlag =
-    Scope.shouldTestFlagInNormalCleanup() ? Scope.getActiveFlag() : 0;
-  llvm::Value *EHActiveFlag = 
-    Scope.shouldTestFlagInEHCleanup() ? Scope.getActiveFlag() : 0;
-
-  // Check whether we need an EH cleanup.  This is only true if we've
-  // generated a lazy EH cleanup block.
-  bool RequiresEHCleanup = Scope.hasEHBranches();
-
-  // Check the three conditions which might require a normal cleanup:
-
-  // - whether there are branch fix-ups through this cleanup
-  unsigned FixupDepth = Scope.getFixupDepth();
-  bool HasFixups = EHStack.getNumBranchFixups() != FixupDepth;
-
-  // - whether there are branch-throughs or branch-afters
-  bool HasExistingBranches = Scope.hasBranches();
-
-  // - whether there's a fallthrough
-  llvm::BasicBlock *FallthroughSource = Builder.GetInsertBlock();
-  bool HasFallthrough = (FallthroughSource != 0 && IsActive);
-
-  // Branch-through fall-throughs leave the insertion point set to the
-  // end of the last cleanup, which points to the current scope.  The
-  // rest of IR gen doesn't need to worry about this; it only happens
-  // during the execution of PopCleanupBlocks().
-  bool HasPrebranchedFallthrough =
-    (FallthroughSource && FallthroughSource->getTerminator());
-
-  // If this is a normal cleanup, then having a prebranched
-  // fallthrough implies that the fallthrough source unconditionally
-  // jumps here.
-  assert(!Scope.isNormalCleanup() || !HasPrebranchedFallthrough ||
-         (Scope.getNormalBlock() &&
-          FallthroughSource->getTerminator()->getSuccessor(0)
-            == Scope.getNormalBlock()));
-
-  bool RequiresNormalCleanup = false;
-  if (Scope.isNormalCleanup() &&
-      (HasFixups || HasExistingBranches || HasFallthrough)) {
-    RequiresNormalCleanup = true;
-  }
-
-  // Even if we don't need the normal cleanup, we might still have
-  // prebranched fallthrough to worry about.
-  if (Scope.isNormalCleanup() && !RequiresNormalCleanup &&
-      HasPrebranchedFallthrough) {
-    assert(!IsActive);
-
-    llvm::BasicBlock *NormalEntry = Scope.getNormalBlock();
-
-    // If we're branching through this cleanup, just forward the
-    // prebranched fallthrough to the next cleanup, leaving the insert
-    // point in the old block.
-    if (FallthroughIsBranchThrough) {
-      EHScope &S = *EHStack.find(Scope.getEnclosingNormalCleanup());
-      llvm::BasicBlock *EnclosingEntry = 
-        CreateNormalEntry(*this, cast<EHCleanupScope>(S));
-
-      ForwardPrebranchedFallthrough(FallthroughSource,
-                                    NormalEntry, EnclosingEntry);
-      assert(NormalEntry->use_empty() &&
-             "uses of entry remain after forwarding?");
-      delete NormalEntry;
-
-    // Otherwise, we're branching out;  just emit the next block.
-    } else {
-      EmitBlock(NormalEntry);
-      SimplifyCleanupEntry(*this, NormalEntry);
-    }
-  }
-
-  // If we don't need the cleanup at all, we're done.
-  if (!RequiresNormalCleanup && !RequiresEHCleanup) {
-    EHStack.popCleanup(); // safe because there are no fixups
-    assert(EHStack.getNumBranchFixups() == 0 ||
-           EHStack.hasNormalCleanups());
-    return;
-  }
-
-  // Copy the cleanup emission data out.  Note that SmallVector
-  // guarantees maximal alignment for its buffer regardless of its
-  // type parameter.
-  llvm::SmallVector<char, 8*sizeof(void*)> CleanupBuffer;
-  CleanupBuffer.reserve(Scope.getCleanupSize());
-  memcpy(CleanupBuffer.data(),
-         Scope.getCleanupBuffer(), Scope.getCleanupSize());
-  CleanupBuffer.set_size(Scope.getCleanupSize());
-  EHScopeStack::Cleanup *Fn =
-    reinterpret_cast<EHScopeStack::Cleanup*>(CleanupBuffer.data());
-
-  // We want to emit the EH cleanup after the normal cleanup, but go
-  // ahead and do the setup for the EH cleanup while the scope is still
-  // alive.
-  llvm::BasicBlock *EHEntry = 0;
-  llvm::SmallVector<llvm::Instruction*, 2> EHInstsToAppend;
-  if (RequiresEHCleanup) {
-    EHEntry = CreateEHEntry(*this, Scope);
-
-    // Figure out the branch-through dest if necessary.
-    llvm::BasicBlock *EHBranchThroughDest = 0;
-    if (Scope.hasEHBranchThroughs()) {
-      assert(Scope.getEnclosingEHCleanup() != EHStack.stable_end());
-      EHScope &S = *EHStack.find(Scope.getEnclosingEHCleanup());
-      EHBranchThroughDest = CreateEHEntry(*this, cast<EHCleanupScope>(S));
-    }
-
-    // If we have exactly one branch-after and no branch-throughs, we
-    // can dispatch it without a switch.
-    if (!Scope.hasEHBranchThroughs() &&
-        Scope.getNumEHBranchAfters() == 1) {
-      assert(!EHBranchThroughDest);
-
-      // TODO: remove the spurious eh.cleanup.dest stores if this edge
-      // never went through any switches.
-      llvm::BasicBlock *BranchAfterDest = Scope.getEHBranchAfterBlock(0);
-      EHInstsToAppend.push_back(llvm::BranchInst::Create(BranchAfterDest));
-    
-    // Otherwise, if we have any branch-afters, we need a switch.
-    } else if (Scope.getNumEHBranchAfters()) {
-      // The default of the switch belongs to the branch-throughs if
-      // they exist.
-      llvm::BasicBlock *Default =
-        (EHBranchThroughDest ? EHBranchThroughDest : getUnreachableBlock());
-
-      const unsigned SwitchCapacity = Scope.getNumEHBranchAfters();
-
-      llvm::LoadInst *Load =
-        new llvm::LoadInst(getEHCleanupDestSlot(), "cleanup.dest");
-      llvm::SwitchInst *Switch =
-        llvm::SwitchInst::Create(Load, Default, SwitchCapacity);
-
-      EHInstsToAppend.push_back(Load);
-      EHInstsToAppend.push_back(Switch);
-
-      for (unsigned I = 0, E = Scope.getNumEHBranchAfters(); I != E; ++I)
-        Switch->addCase(Scope.getEHBranchAfterIndex(I),
-                        Scope.getEHBranchAfterBlock(I));
-
-    // Otherwise, we have only branch-throughs; jump to the next EH
-    // cleanup.
-    } else {
-      assert(EHBranchThroughDest);
-      EHInstsToAppend.push_back(llvm::BranchInst::Create(EHBranchThroughDest));
-    }
-  }
-
-  if (!RequiresNormalCleanup) {
-    EHStack.popCleanup();
-  } else {
-    // If we have a fallthrough and no other need for the cleanup,
-    // emit it directly.
-    if (HasFallthrough && !HasPrebranchedFallthrough &&
-        !HasFixups && !HasExistingBranches) {
-
-      // Fixups can cause us to optimistically create a normal block,
-      // only to later have no real uses for it.  Just delete it in
-      // this case.
-      // TODO: we can potentially simplify all the uses after this.
-      if (Scope.getNormalBlock()) {
-        Scope.getNormalBlock()->replaceAllUsesWith(getUnreachableBlock());
-        delete Scope.getNormalBlock();
-      }
-
-      EHStack.popCleanup();
-
-      EmitCleanup(*this, Fn, /*ForEH*/ false, NormalActiveFlag);
-
-    // Otherwise, the best approach is to thread everything through
-    // the cleanup block and then try to clean up after ourselves.
-    } else {
-      // Force the entry block to exist.
-      llvm::BasicBlock *NormalEntry = CreateNormalEntry(*this, Scope);
-
-      // I.  Set up the fallthrough edge in.
-
-      // If there's a fallthrough, we need to store the cleanup
-      // destination index.  For fall-throughs this is always zero.
-      if (HasFallthrough) {
-        if (!HasPrebranchedFallthrough)
-          Builder.CreateStore(Builder.getInt32(0), getNormalCleanupDestSlot());
-
-      // Otherwise, clear the IP if we don't have fallthrough because
-      // the cleanup is inactive.  We don't need to save it because
-      // it's still just FallthroughSource.
-      } else if (FallthroughSource) {
-        assert(!IsActive && "source without fallthrough for active cleanup");
-        Builder.ClearInsertionPoint();
-      }
-
-      // II.  Emit the entry block.  This implicitly branches to it if
-      // we have fallthrough.  All the fixups and existing branches
-      // should already be branched to it.
-      EmitBlock(NormalEntry);
-
-      // III.  Figure out where we're going and build the cleanup
-      // epilogue.
-
-      bool HasEnclosingCleanups =
-        (Scope.getEnclosingNormalCleanup() != EHStack.stable_end());
-
-      // Compute the branch-through dest if we need it:
-      //   - if there are branch-throughs threaded through the scope
-      //   - if fall-through is a branch-through
-      //   - if there are fixups that will be optimistically forwarded
-      //     to the enclosing cleanup
-      llvm::BasicBlock *BranchThroughDest = 0;
-      if (Scope.hasBranchThroughs() ||
-          (FallthroughSource && FallthroughIsBranchThrough) ||
-          (HasFixups && HasEnclosingCleanups)) {
-        assert(HasEnclosingCleanups);
-        EHScope &S = *EHStack.find(Scope.getEnclosingNormalCleanup());
-        BranchThroughDest = CreateNormalEntry(*this, cast<EHCleanupScope>(S));
-      }
-
-      llvm::BasicBlock *FallthroughDest = 0;
-      llvm::SmallVector<llvm::Instruction*, 2> InstsToAppend;
-
-      // If there's exactly one branch-after and no other threads,
-      // we can route it without a switch.
-      if (!Scope.hasBranchThroughs() && !HasFixups && !HasFallthrough &&
-          Scope.getNumBranchAfters() == 1) {
-        assert(!BranchThroughDest || !IsActive);
-
-        // TODO: clean up the possibly dead stores to the cleanup dest slot.
-        llvm::BasicBlock *BranchAfter = Scope.getBranchAfterBlock(0);
-        InstsToAppend.push_back(llvm::BranchInst::Create(BranchAfter));
-
-      // Build a switch-out if we need it:
-      //   - if there are branch-afters threaded through the scope
-      //   - if fall-through is a branch-after
-      //   - if there are fixups that have nowhere left to go and
-      //     so must be immediately resolved
-      } else if (Scope.getNumBranchAfters() ||
-                 (HasFallthrough && !FallthroughIsBranchThrough) ||
-                 (HasFixups && !HasEnclosingCleanups)) {
-
-        llvm::BasicBlock *Default =
-          (BranchThroughDest ? BranchThroughDest : getUnreachableBlock());
-
-        // TODO: base this on the number of branch-afters and fixups
-        const unsigned SwitchCapacity = 10;
-
-        llvm::LoadInst *Load =
-          new llvm::LoadInst(getNormalCleanupDestSlot(), "cleanup.dest");
-        llvm::SwitchInst *Switch =
-          llvm::SwitchInst::Create(Load, Default, SwitchCapacity);
-
-        InstsToAppend.push_back(Load);
-        InstsToAppend.push_back(Switch);
-
-        // Branch-after fallthrough.
-        if (FallthroughSource && !FallthroughIsBranchThrough) {
-          FallthroughDest = createBasicBlock("cleanup.cont");
-          if (HasFallthrough)
-            Switch->addCase(Builder.getInt32(0), FallthroughDest);
-        }
-
-        for (unsigned I = 0, E = Scope.getNumBranchAfters(); I != E; ++I) {
-          Switch->addCase(Scope.getBranchAfterIndex(I),
-                          Scope.getBranchAfterBlock(I));
-        }
-
-        // If there aren't any enclosing cleanups, we can resolve all
-        // the fixups now.
-        if (HasFixups && !HasEnclosingCleanups)
-          ResolveAllBranchFixups(*this, Switch, NormalEntry);
-      } else {
-        // We should always have a branch-through destination in this case.
-        assert(BranchThroughDest);
-        InstsToAppend.push_back(llvm::BranchInst::Create(BranchThroughDest));
-      }
-
-      // IV.  Pop the cleanup and emit it.
-      EHStack.popCleanup();
-      assert(EHStack.hasNormalCleanups() == HasEnclosingCleanups);
-
-      EmitCleanup(*this, Fn, /*ForEH*/ false, NormalActiveFlag);
-
-      // Append the prepared cleanup prologue from above.
-      llvm::BasicBlock *NormalExit = Builder.GetInsertBlock();
-      for (unsigned I = 0, E = InstsToAppend.size(); I != E; ++I)
-        NormalExit->getInstList().push_back(InstsToAppend[I]);
-
-      // Optimistically hope that any fixups will continue falling through.
-      for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups();
-           I < E; ++I) {
-        BranchFixup &Fixup = CGF.EHStack.getBranchFixup(I);
-        if (!Fixup.Destination) continue;
-        if (!Fixup.OptimisticBranchBlock) {
-          new llvm::StoreInst(Builder.getInt32(Fixup.DestinationIndex),
-                              getNormalCleanupDestSlot(),
-                              Fixup.InitialBranch);
-          Fixup.InitialBranch->setSuccessor(0, NormalEntry);
-        }
-        Fixup.OptimisticBranchBlock = NormalExit;
-      }
-
-      // V.  Set up the fallthrough edge out.
-      
-      // Case 1: a fallthrough source exists but shouldn't branch to
-      // the cleanup because the cleanup is inactive.
-      if (!HasFallthrough && FallthroughSource) {
-        assert(!IsActive);
-
-        // If we have a prebranched fallthrough, that needs to be
-        // forwarded to the right block.
-        if (HasPrebranchedFallthrough) {
-          llvm::BasicBlock *Next;
-          if (FallthroughIsBranchThrough) {
-            Next = BranchThroughDest;
-            assert(!FallthroughDest);
-          } else {
-            Next = FallthroughDest;
-          }
-
-          ForwardPrebranchedFallthrough(FallthroughSource, NormalEntry, Next);
-        }
-        Builder.SetInsertPoint(FallthroughSource);
-
-      // Case 2: a fallthrough source exists and should branch to the
-      // cleanup, but we're not supposed to branch through to the next
-      // cleanup.
-      } else if (HasFallthrough && FallthroughDest) {
-        assert(!FallthroughIsBranchThrough);
-        EmitBlock(FallthroughDest);
-
-      // Case 3: a fallthrough source exists and should branch to the
-      // cleanup and then through to the next.
-      } else if (HasFallthrough) {
-        // Everything is already set up for this.
-
-      // Case 4: no fallthrough source exists.
-      } else {
-        Builder.ClearInsertionPoint();
-      }
-
-      // VI.  Assorted cleaning.
-
-      // Check whether we can merge NormalEntry into a single predecessor.
-      // This might invalidate (non-IR) pointers to NormalEntry.
-      llvm::BasicBlock *NewNormalEntry =
-        SimplifyCleanupEntry(*this, NormalEntry);
-
-      // If it did invalidate those pointers, and NormalEntry was the same
-      // as NormalExit, go back and patch up the fixups.
-      if (NewNormalEntry != NormalEntry && NormalEntry == NormalExit)
-        for (unsigned I = FixupDepth, E = EHStack.getNumBranchFixups();
-               I < E; ++I)
-          CGF.EHStack.getBranchFixup(I).OptimisticBranchBlock = NewNormalEntry;
-    }
-  }
-
-  assert(EHStack.hasNormalCleanups() || EHStack.getNumBranchFixups() == 0);
-
-  // Emit the EH cleanup if required.
-  if (RequiresEHCleanup) {
-    CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
-
-    EmitBlock(EHEntry);
-    EmitCleanup(*this, Fn, /*ForEH*/ true, EHActiveFlag);
-
-    // Append the prepared cleanup prologue from above.
-    llvm::BasicBlock *EHExit = Builder.GetInsertBlock();
-    for (unsigned I = 0, E = EHInstsToAppend.size(); I != E; ++I)
-      EHExit->getInstList().push_back(EHInstsToAppend[I]);
-
-    Builder.restoreIP(SavedIP);
-
-    SimplifyCleanupEntry(*this, EHEntry);
-  }
-}
-
-/// Terminate the current block by emitting a branch which might leave
-/// the current cleanup-protected scope.  The target scope may not yet
-/// be known, in which case this will require a fixup.
-///
-/// As a side-effect, this method clears the insertion point.
-void CodeGenFunction::EmitBranchThroughCleanup(JumpDest Dest) {
-  assert(Dest.getScopeDepth().encloses(EHStack.getInnermostNormalCleanup())
-         && "stale jump destination");
-
-  if (!HaveInsertPoint())
-    return;
-
-  // Create the branch.
-  llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock());
-
-  // Calculate the innermost active normal cleanup.
-  EHScopeStack::stable_iterator
-    TopCleanup = EHStack.getInnermostActiveNormalCleanup();
-
-  // If we're not in an active normal cleanup scope, or if the
-  // destination scope is within the innermost active normal cleanup
-  // scope, we don't need to worry about fixups.
-  if (TopCleanup == EHStack.stable_end() ||
-      TopCleanup.encloses(Dest.getScopeDepth())) { // works for invalid
-    Builder.ClearInsertionPoint();
-    return;
-  }
-
-  // If we can't resolve the destination cleanup scope, just add this
-  // to the current cleanup scope as a branch fixup.
-  if (!Dest.getScopeDepth().isValid()) {
-    BranchFixup &Fixup = EHStack.addBranchFixup();
-    Fixup.Destination = Dest.getBlock();
-    Fixup.DestinationIndex = Dest.getDestIndex();
-    Fixup.InitialBranch = BI;
-    Fixup.OptimisticBranchBlock = 0;
-
-    Builder.ClearInsertionPoint();
-    return;
-  }
-
-  // Otherwise, thread through all the normal cleanups in scope.
-
-  // Store the index at the start.
-  llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex());
-  new llvm::StoreInst(Index, getNormalCleanupDestSlot(), BI);
-
-  // Adjust BI to point to the first cleanup block.
-  {
-    EHCleanupScope &Scope =
-      cast<EHCleanupScope>(*EHStack.find(TopCleanup));
-    BI->setSuccessor(0, CreateNormalEntry(*this, Scope));
-  }
-
-  // Add this destination to all the scopes involved.
-  EHScopeStack::stable_iterator I = TopCleanup;
-  EHScopeStack::stable_iterator E = Dest.getScopeDepth();
-  if (E.strictlyEncloses(I)) {
-    while (true) {
-      EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I));
-      assert(Scope.isNormalCleanup());
-      I = Scope.getEnclosingNormalCleanup();
-
-      // If this is the last cleanup we're propagating through, tell it
-      // that there's a resolved jump moving through it.
-      if (!E.strictlyEncloses(I)) {
-        Scope.addBranchAfter(Index, Dest.getBlock());
-        break;
-      }
-
-      // Otherwise, tell the scope that there's a jump propoagating
-      // through it.  If this isn't new information, all the rest of
-      // the work has been done before.
-      if (!Scope.addBranchThrough(Dest.getBlock()))
-        break;
-    }
-  }
-  
-  Builder.ClearInsertionPoint();
-}
-
-void CodeGenFunction::EmitBranchThroughEHCleanup(UnwindDest Dest) {
-  // We should never get invalid scope depths for an UnwindDest; that
-  // implies that the destination wasn't set up correctly.
-  assert(Dest.getScopeDepth().isValid() && "invalid scope depth on EH dest?");
-
-  if (!HaveInsertPoint())
-    return;
-
-  // Create the branch.
-  llvm::BranchInst *BI = Builder.CreateBr(Dest.getBlock());
-
-  // Calculate the innermost active cleanup.
-  EHScopeStack::stable_iterator
-    InnermostCleanup = EHStack.getInnermostActiveEHCleanup();
-
-  // If the destination is in the same EH cleanup scope as us, we
-  // don't need to thread through anything.
-  if (InnermostCleanup.encloses(Dest.getScopeDepth())) {
-    Builder.ClearInsertionPoint();
-    return;
-  }
-  assert(InnermostCleanup != EHStack.stable_end());
-
-  // Store the index at the start.
-  llvm::ConstantInt *Index = Builder.getInt32(Dest.getDestIndex());
-  new llvm::StoreInst(Index, getEHCleanupDestSlot(), BI);
-
-  // Adjust BI to point to the first cleanup block.
-  {
-    EHCleanupScope &Scope =
-      cast<EHCleanupScope>(*EHStack.find(InnermostCleanup));
-    BI->setSuccessor(0, CreateEHEntry(*this, Scope));
-  }
-  
-  // Add this destination to all the scopes involved.
-  for (EHScopeStack::stable_iterator
-         I = InnermostCleanup, E = Dest.getScopeDepth(); ; ) {
-    assert(E.strictlyEncloses(I));
-    EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(I));
-    assert(Scope.isEHCleanup());
-    I = Scope.getEnclosingEHCleanup();
-
-    // If this is the last cleanup we're propagating through, add this
-    // as a branch-after.
-    if (I == E) {
-      Scope.addEHBranchAfter(Index, Dest.getBlock());
-      break;
-    }
-
-    // Otherwise, add it as a branch-through.  If this isn't new
-    // information, all the rest of the work has been done before.
-    if (!Scope.addEHBranchThrough(Dest.getBlock()))
-      break;
-  }
-  
-  Builder.ClearInsertionPoint();
-}
-
-/// All the branch fixups on the EH stack have propagated out past the
-/// outermost normal cleanup; resolve them all by adding cases to the
-/// given switch instruction.
-static void ResolveAllBranchFixups(CodeGenFunction &CGF,
-                                   llvm::SwitchInst *Switch,
-                                   llvm::BasicBlock *CleanupEntry) {
-  llvm::SmallPtrSet<llvm::BasicBlock*, 4> CasesAdded;
-
-  for (unsigned I = 0, E = CGF.EHStack.getNumBranchFixups(); I != E; ++I) {
-    // Skip this fixup if its destination isn't set.
-    BranchFixup &Fixup = CGF.EHStack.getBranchFixup(I);
-    if (Fixup.Destination == 0) continue;
-
-    // If there isn't an OptimisticBranchBlock, then InitialBranch is
-    // still pointing directly to its destination; forward it to the
-    // appropriate cleanup entry.  This is required in the specific
-    // case of
-    //   { std::string s; goto lbl; }
-    //   lbl:
-    // i.e. where there's an unresolved fixup inside a single cleanup
-    // entry which we're currently popping.
-    if (Fixup.OptimisticBranchBlock == 0) {
-      new llvm::StoreInst(CGF.Builder.getInt32(Fixup.DestinationIndex),
-                          CGF.getNormalCleanupDestSlot(),
-                          Fixup.InitialBranch);
-      Fixup.InitialBranch->setSuccessor(0, CleanupEntry);
-    }
-
-    // Don't add this case to the switch statement twice.
-    if (!CasesAdded.insert(Fixup.Destination)) continue;
-
-    Switch->addCase(CGF.Builder.getInt32(Fixup.DestinationIndex),
-                    Fixup.Destination);
-  }
-
-  CGF.EHStack.clearFixups();
-}
-
-void CodeGenFunction::ResolveBranchFixups(llvm::BasicBlock *Block) {
-  assert(Block && "resolving a null target block");
-  if (!EHStack.getNumBranchFixups()) return;
-
-  assert(EHStack.hasNormalCleanups() &&
-         "branch fixups exist with no normal cleanups on stack");
-
-  llvm::SmallPtrSet<llvm::BasicBlock*, 4> ModifiedOptimisticBlocks;
-  bool ResolvedAny = false;
-
-  for (unsigned I = 0, E = EHStack.getNumBranchFixups(); I != E; ++I) {
-    // Skip this fixup if its destination doesn't match.
-    BranchFixup &Fixup = EHStack.getBranchFixup(I);
-    if (Fixup.Destination != Block) continue;
-
-    Fixup.Destination = 0;
-    ResolvedAny = true;
-
-    // If it doesn't have an optimistic branch block, LatestBranch is
-    // already pointing to the right place.
-    llvm::BasicBlock *BranchBB = Fixup.OptimisticBranchBlock;
-    if (!BranchBB)
-      continue;
-
-    // Don't process the same optimistic branch block twice.
-    if (!ModifiedOptimisticBlocks.insert(BranchBB))
-      continue;
-
-    llvm::SwitchInst *Switch = TransitionToCleanupSwitch(*this, BranchBB);
-
-    // Add a case to the switch.
-    Switch->addCase(Builder.getInt32(Fixup.DestinationIndex), Block);
-  }
-
-  if (ResolvedAny)
-    EHStack.popNullFixups();
-}
-
-static bool IsUsedAsNormalCleanup(EHScopeStack &EHStack,
-                                  EHScopeStack::stable_iterator C) {
-  // If we needed a normal block for any reason, that counts.
-  if (cast<EHCleanupScope>(*EHStack.find(C)).getNormalBlock())
-    return true;
-
-  // Check whether any enclosed cleanups were needed.
-  for (EHScopeStack::stable_iterator
-         I = EHStack.getInnermostNormalCleanup();
-         I != C; ) {
-    assert(C.strictlyEncloses(I));
-    EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I));
-    if (S.getNormalBlock()) return true;
-    I = S.getEnclosingNormalCleanup();
-  }
-
-  return false;
-}
-
-static bool IsUsedAsEHCleanup(EHScopeStack &EHStack,
-                              EHScopeStack::stable_iterator C) {
-  // If we needed an EH block for any reason, that counts.
-  if (cast<EHCleanupScope>(*EHStack.find(C)).getEHBlock())
-    return true;
-
-  // Check whether any enclosed cleanups were needed.
-  for (EHScopeStack::stable_iterator
-         I = EHStack.getInnermostEHCleanup(); I != C; ) {
-    assert(C.strictlyEncloses(I));
-    EHCleanupScope &S = cast<EHCleanupScope>(*EHStack.find(I));
-    if (S.getEHBlock()) return true;
-    I = S.getEnclosingEHCleanup();
-  }
-
-  return false;
-}
-
-enum ForActivation_t {
-  ForActivation,
-  ForDeactivation
-};
-
-/// The given cleanup block is changing activation state.  Configure a
-/// cleanup variable if necessary.
-///
-/// It would be good if we had some way of determining if there were
-/// extra uses *after* the change-over point.
-static void SetupCleanupBlockActivation(CodeGenFunction &CGF,
-                                        EHScopeStack::stable_iterator C,
-                                        ForActivation_t Kind) {
-  EHCleanupScope &Scope = cast<EHCleanupScope>(*CGF.EHStack.find(C));
-
-  // We always need the flag if we're activating the cleanup, because
-  // we have to assume that the current location doesn't necessarily
-  // dominate all future uses of the cleanup.
-  bool NeedFlag = (Kind == ForActivation);
-
-  // Calculate whether the cleanup was used:
-
-  //   - as a normal cleanup
-  if (Scope.isNormalCleanup() && IsUsedAsNormalCleanup(CGF.EHStack, C)) {
-    Scope.setTestFlagInNormalCleanup();
-    NeedFlag = true;
-  }
-
-  //  - as an EH cleanup
-  if (Scope.isEHCleanup() && IsUsedAsEHCleanup(CGF.EHStack, C)) {
-    Scope.setTestFlagInEHCleanup();
-    NeedFlag = true;
-  }
-
-  // If it hasn't yet been used as either, we're done.
-  if (!NeedFlag) return;
-
-  llvm::AllocaInst *Var = Scope.getActiveFlag();
-  if (!Var) {
-    Var = CGF.CreateTempAlloca(CGF.Builder.getInt1Ty(), "cleanup.isactive");
-    Scope.setActiveFlag(Var);
-
-    // Initialize to true or false depending on whether it was
-    // active up to this point.
-    CGF.InitTempAlloca(Var, CGF.Builder.getInt1(Kind == ForDeactivation));
-  }
-
-  CGF.Builder.CreateStore(CGF.Builder.getInt1(Kind == ForActivation), Var);
-}
-
-/// Activate a cleanup that was created in an inactivated state.
-void CodeGenFunction::ActivateCleanupBlock(EHScopeStack::stable_iterator C) {
-  assert(C != EHStack.stable_end() && "activating bottom of stack?");
-  EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(C));
-  assert(!Scope.isActive() && "double activation");
-
-  SetupCleanupBlockActivation(*this, C, ForActivation);
-
-  Scope.setActive(true);
-}
-
-/// Deactive a cleanup that was created in an active state.
-void CodeGenFunction::DeactivateCleanupBlock(EHScopeStack::stable_iterator C) {
-  assert(C != EHStack.stable_end() && "deactivating bottom of stack?");
-  EHCleanupScope &Scope = cast<EHCleanupScope>(*EHStack.find(C));
-  assert(Scope.isActive() && "double deactivation");
-
-  // If it's the top of the stack, just pop it.
-  if (C == EHStack.stable_begin()) {
-    // If it's a normal cleanup, we need to pretend that the
-    // fallthrough is unreachable.
-    CGBuilderTy::InsertPoint SavedIP = Builder.saveAndClearIP();
-    PopCleanupBlock();
-    Builder.restoreIP(SavedIP);
-    return;
-  }
-
-  // Otherwise, follow the general case.
-  SetupCleanupBlockActivation(*this, C, ForDeactivation);
-
-  Scope.setActive(false);
-}
-
-llvm::Value *CodeGenFunction::getNormalCleanupDestSlot() {
-  if (!NormalCleanupDest)
-    NormalCleanupDest =
-      CreateTempAlloca(Builder.getInt32Ty(), "cleanup.dest.slot");
-  return NormalCleanupDest;
-}
-
-llvm::Value *CodeGenFunction::getEHCleanupDestSlot() {
-  if (!EHCleanupDest)
-    EHCleanupDest =
-      CreateTempAlloca(Builder.getInt32Ty(), "eh.cleanup.dest.slot");
-  return EHCleanupDest;
-}
-
 void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E, 
                                               llvm::Constant *Init) {
   assert (Init && "Invalid DeclRefExpr initializer!");