Check in LLVM r95781.
diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
new file mode 100644
index 0000000..05d138b
--- /dev/null
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -0,0 +1,1219 @@
+//===--- CGBlocks.cpp - Emit LLVM Code for declarations -------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code to emit blocks.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGDebugInfo.h"
+#include "CodeGenFunction.h"
+#include "CodeGenModule.h"
+#include "clang/AST/DeclObjC.h"
+#include "llvm/Module.h"
+#include "llvm/Target/TargetData.h"
+#include <algorithm>
+
+using namespace clang;
+using namespace CodeGen;
+
+llvm::Constant *CodeGenFunction::
+BuildDescriptorBlockDecl(bool BlockHasCopyDispose, CharUnits Size,
+                         const llvm::StructType* Ty,
+                         std::vector<HelperInfo> *NoteForHelper) {
+  const llvm::Type *UnsignedLongTy
+    = CGM.getTypes().ConvertType(getContext().UnsignedLongTy);
+  llvm::Constant *C;
+  std::vector<llvm::Constant*> Elts;
+
+  // reserved
+  C = llvm::ConstantInt::get(UnsignedLongTy, 0);
+  Elts.push_back(C);
+
+  // Size
+  // FIXME: What is the right way to say this doesn't fit?  We should give
+  // a user diagnostic in that case.  Better fix would be to change the
+  // API to size_t.
+  C = llvm::ConstantInt::get(UnsignedLongTy, Size.getQuantity());
+  Elts.push_back(C);
+
+  if (BlockHasCopyDispose) {
+    // copy_func_helper_decl
+    Elts.push_back(BuildCopyHelper(Ty, NoteForHelper));
+
+    // destroy_func_decl
+    Elts.push_back(BuildDestroyHelper(Ty, NoteForHelper));
+  }
+
+  C = llvm::ConstantStruct::get(VMContext, Elts, false);
+
+  C = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true,
+                               llvm::GlobalValue::InternalLinkage,
+                               C, "__block_descriptor_tmp");
+  return C;
+}
+
+llvm::Constant *BlockModule::getNSConcreteGlobalBlock() {
+  if (NSConcreteGlobalBlock == 0)
+    NSConcreteGlobalBlock = CGM.CreateRuntimeVariable(PtrToInt8Ty,
+                                                      "_NSConcreteGlobalBlock");
+  return NSConcreteGlobalBlock;
+}
+
+llvm::Constant *BlockModule::getNSConcreteStackBlock() {
+  if (NSConcreteStackBlock == 0)
+    NSConcreteStackBlock = CGM.CreateRuntimeVariable(PtrToInt8Ty,
+                                                     "_NSConcreteStackBlock");
+  return NSConcreteStackBlock;
+}
+
+static void CollectBlockDeclRefInfo(
+  const Stmt *S, CodeGenFunction::BlockInfo &Info,
+  llvm::SmallSet<const DeclContext *, 16> &InnerContexts) {
+  for (Stmt::const_child_iterator I = S->child_begin(), E = S->child_end();
+       I != E; ++I)
+    if (*I)
+      CollectBlockDeclRefInfo(*I, Info, InnerContexts);
+
+  // We want to ensure we walk down into block literals so we can find
+  // all nested BlockDeclRefExprs.
+  if (const BlockExpr *BE = dyn_cast<BlockExpr>(S)) {
+    InnerContexts.insert(cast<DeclContext>(BE->getBlockDecl()));
+    CollectBlockDeclRefInfo(BE->getBody(), Info, InnerContexts);
+  }
+
+  if (const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(S)) {
+    // FIXME: Handle enums.
+    if (isa<FunctionDecl>(BDRE->getDecl()))
+      return;
+
+    // Only Decls that escape are added.
+    if (!InnerContexts.count(BDRE->getDecl()->getDeclContext()))
+      Info.DeclRefs.push_back(BDRE);
+  }
+}
+
+/// CanBlockBeGlobal - Given a BlockInfo struct, determines if a block can be
+/// declared as a global variable instead of on the stack.
+static bool CanBlockBeGlobal(const CodeGenFunction::BlockInfo &Info) {
+  return Info.DeclRefs.empty();
+}
+
+/// AllocateAllBlockDeclRefs - Preallocate all nested BlockDeclRefExprs to
+/// ensure we can generate the debug information for the parameter for the block
+/// invoke function.
+static void AllocateAllBlockDeclRefs(const CodeGenFunction::BlockInfo &Info,
+                                     CodeGenFunction *CGF) {
+  // Always allocate self, as it is often handy in the debugger, even if there
+  // is no codegen in the block that uses it.  This is also useful to always do
+  // this as if we didn't, we'd have to figure out all code that uses a self
+  // pointer, including implicit uses.
+  if (const ObjCMethodDecl *OMD
+      = dyn_cast_or_null<ObjCMethodDecl>(CGF->CurFuncDecl)) {
+    ImplicitParamDecl *SelfDecl = OMD->getSelfDecl();
+    BlockDeclRefExpr *BDRE = new (CGF->getContext())
+      BlockDeclRefExpr(SelfDecl,
+                       SelfDecl->getType(), SourceLocation(), false);
+    CGF->AllocateBlockDecl(BDRE);
+  }
+
+  // FIXME: Also always forward the this pointer in C++ as well.
+
+  for (size_t i = 0; i < Info.DeclRefs.size(); ++i)
+    CGF->AllocateBlockDecl(Info.DeclRefs[i]);
+}
+
+// FIXME: Push most into CGM, passing down a few bits, like current function
+// name.
+llvm::Value *CodeGenFunction::BuildBlockLiteralTmp(const BlockExpr *BE) {
+
+  std::string Name = CurFn->getName();
+  CodeGenFunction::BlockInfo Info(0, Name.c_str());
+  llvm::SmallSet<const DeclContext *, 16> InnerContexts;
+  InnerContexts.insert(BE->getBlockDecl());
+  CollectBlockDeclRefInfo(BE->getBody(), Info, InnerContexts);
+
+  // Check if the block can be global.
+  // FIXME: This test doesn't work for nested blocks yet.  Longer term, I'd like
+  // to just have one code path.  We should move this function into CGM and pass
+  // CGF, then we can just check to see if CGF is 0.
+  if (0 && CanBlockBeGlobal(Info))
+    return CGM.GetAddrOfGlobalBlock(BE, Name.c_str());
+
+  size_t BlockFields = 5;
+
+  bool hasIntrospection  = CGM.getContext().getLangOptions().BlockIntrospection;
+
+  if (hasIntrospection) {
+    BlockFields++;
+  }
+  std::vector<llvm::Constant*> Elts(BlockFields);
+
+  if (hasIntrospection) {
+    std::string BlockTypeEncoding;
+    CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
+
+    Elts[5] = llvm::ConstantExpr::getBitCast(
+            CGM.GetAddrOfConstantCString(BlockTypeEncoding), PtrToInt8Ty);
+  }
+
+  llvm::Constant *C;
+  llvm::Value *V;
+
+  {
+    // C = BuildBlockStructInitlist();
+    unsigned int flags = BLOCK_HAS_DESCRIPTOR;
+
+    if (hasIntrospection)
+      flags |= BLOCK_HAS_OBJC_TYPE;
+
+    // We run this first so that we set BlockHasCopyDispose from the entire
+    // block literal.
+    // __invoke
+    CharUnits subBlockSize; 
+    CharUnits subBlockAlign;
+    llvm::SmallVector<const Expr *, 8> subBlockDeclRefDecls;
+    bool subBlockHasCopyDispose = false;
+    llvm::Function *Fn
+      = CodeGenFunction(CGM).GenerateBlockFunction(BE, Info, CurFuncDecl,
+                                                   LocalDeclMap,
+                                                   subBlockSize,
+                                                   subBlockAlign,
+                                                   subBlockDeclRefDecls,
+                                                   subBlockHasCopyDispose);
+    BlockHasCopyDispose |= subBlockHasCopyDispose;
+    Elts[3] = Fn;
+
+    // FIXME: Don't use BlockHasCopyDispose, it is set more often then
+    // necessary, for example: { ^{ __block int i; ^{ i = 1; }(); }(); }
+    if (subBlockHasCopyDispose)
+      flags |= BLOCK_HAS_COPY_DISPOSE;
+
+    // __isa
+    C = CGM.getNSConcreteStackBlock();
+    C = llvm::ConstantExpr::getBitCast(C, PtrToInt8Ty);
+    Elts[0] = C;
+
+    // __flags
+    const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
+      CGM.getTypes().ConvertType(CGM.getContext().IntTy));
+    C = llvm::ConstantInt::get(IntTy, flags);
+    Elts[1] = C;
+
+    // __reserved
+    C = llvm::ConstantInt::get(IntTy, 0);
+    Elts[2] = C;
+
+    if (subBlockDeclRefDecls.size() == 0) {
+      // __descriptor
+      Elts[4] = BuildDescriptorBlockDecl(subBlockHasCopyDispose, subBlockSize,
+                                         0, 0);
+
+      // Optimize to being a global block.
+      Elts[0] = CGM.getNSConcreteGlobalBlock();
+      Elts[1] = llvm::ConstantInt::get(IntTy, flags|BLOCK_IS_GLOBAL);
+
+      C = llvm::ConstantStruct::get(VMContext, Elts, false);
+
+      C = new llvm::GlobalVariable(CGM.getModule(), C->getType(), true,
+                                   llvm::GlobalValue::InternalLinkage, C,
+                                   "__block_holder_tmp_" +
+                                   llvm::Twine(CGM.getGlobalUniqueCount()));
+      QualType BPT = BE->getType();
+      C = llvm::ConstantExpr::getBitCast(C, ConvertType(BPT));
+      return C;
+    }
+
+    std::vector<const llvm::Type *> Types(BlockFields+subBlockDeclRefDecls.size());
+    for (int i=0; i<4; ++i)
+      Types[i] = Elts[i]->getType();
+    Types[4] = PtrToInt8Ty;
+    if (hasIntrospection)
+      Types[5] = PtrToInt8Ty;
+
+    for (unsigned i=0; i < subBlockDeclRefDecls.size(); ++i) {
+      const Expr *E = subBlockDeclRefDecls[i];
+      const BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E);
+      QualType Ty = E->getType();
+      if (BDRE && BDRE->isByRef()) {
+        Types[i+BlockFields] = llvm::PointerType::get(BuildByRefType(BDRE->getDecl()), 0);
+      } else
+        Types[i+BlockFields] = ConvertType(Ty);
+    }
+
+    llvm::StructType *Ty = llvm::StructType::get(VMContext, Types, true);
+
+    llvm::AllocaInst *A = CreateTempAlloca(Ty);
+    A->setAlignment(subBlockAlign.getQuantity());
+    V = A;
+
+    std::vector<HelperInfo> NoteForHelper(subBlockDeclRefDecls.size());
+    int helpersize = 0;
+
+    for (unsigned i=0; i<4; ++i)
+      Builder.CreateStore(Elts[i], Builder.CreateStructGEP(V, i, "block.tmp"));
+    if (hasIntrospection)
+      Builder.CreateStore(Elts[5], Builder.CreateStructGEP(V, 5, "block.tmp"));
+
+    for (unsigned i=0; i < subBlockDeclRefDecls.size(); ++i)
+      {
+        // FIXME: Push const down.
+        Expr *E = const_cast<Expr*>(subBlockDeclRefDecls[i]);
+        DeclRefExpr *DR;
+        ValueDecl *VD;
+
+        DR = dyn_cast<DeclRefExpr>(E);
+        // Skip padding.
+        if (DR) continue;
+
+        BlockDeclRefExpr *BDRE = dyn_cast<BlockDeclRefExpr>(E);
+        VD = BDRE->getDecl();
+
+        llvm::Value* Addr = Builder.CreateStructGEP(V, i+BlockFields, "tmp");
+        NoteForHelper[helpersize].index = i+5;
+        NoteForHelper[helpersize].RequiresCopying
+          = BlockRequiresCopying(VD->getType());
+        NoteForHelper[helpersize].flag
+          = (VD->getType()->isBlockPointerType()
+             ? BLOCK_FIELD_IS_BLOCK
+             : BLOCK_FIELD_IS_OBJECT);
+
+        if (LocalDeclMap[VD]) {
+          if (BDRE->isByRef()) {
+            NoteForHelper[helpersize].flag = BLOCK_FIELD_IS_BYREF |
+              // FIXME: Someone double check this.
+              (VD->getType().isObjCGCWeak() ? BLOCK_FIELD_IS_WEAK : 0);
+            llvm::Value *Loc = LocalDeclMap[VD];
+            Loc = Builder.CreateStructGEP(Loc, 1, "forwarding");
+            Loc = Builder.CreateLoad(Loc);
+            Builder.CreateStore(Loc, Addr);
+            ++helpersize;
+            continue;
+          } else
+            E = new (getContext()) DeclRefExpr (VD,
+                                                VD->getType(), 
+                                                SourceLocation());
+        }
+        if (BDRE->isByRef()) {
+          NoteForHelper[helpersize].flag = BLOCK_FIELD_IS_BYREF |
+            // FIXME: Someone double check this.
+            (VD->getType().isObjCGCWeak() ? BLOCK_FIELD_IS_WEAK : 0);
+          E = new (getContext())
+            UnaryOperator(E, UnaryOperator::AddrOf,
+                          getContext().getPointerType(E->getType()),
+                          SourceLocation());
+        }
+        ++helpersize;
+
+        RValue r = EmitAnyExpr(E, Addr, false);
+        if (r.isScalar()) {
+          llvm::Value *Loc = r.getScalarVal();
+          const llvm::Type *Ty = Types[i+BlockFields];
+          if  (BDRE->isByRef()) {
+            // E is now the address of the value field, instead, we want the
+            // address of the actual ByRef struct.  We optimize this slightly
+            // compared to gcc by not grabbing the forwarding slot as this must
+            // be done during Block_copy for us, and we can postpone the work
+            // until then.
+            CharUnits offset = BlockDecls[BDRE->getDecl()];
+
+            llvm::Value *BlockLiteral = LoadBlockStruct();
+
+            Loc = Builder.CreateGEP(BlockLiteral,
+                       llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext),
+                                                           offset.getQuantity()),
+                                    "block.literal");
+            Ty = llvm::PointerType::get(Ty, 0);
+            Loc = Builder.CreateBitCast(Loc, Ty);
+            Loc = Builder.CreateLoad(Loc);
+            // Loc = Builder.CreateBitCast(Loc, Ty);
+          }
+          Builder.CreateStore(Loc, Addr);
+        } else if (r.isComplex())
+          // FIXME: implement
+          ErrorUnsupported(BE, "complex in block literal");
+        else if (r.isAggregate())
+          ; // Already created into the destination
+        else
+          assert (0 && "bad block variable");
+        // FIXME: Ensure that the offset created by the backend for
+        // the struct matches the previously computed offset in BlockDecls.
+      }
+    NoteForHelper.resize(helpersize);
+
+    // __descriptor
+    llvm::Value *Descriptor = BuildDescriptorBlockDecl(subBlockHasCopyDispose,
+                                                       subBlockSize, Ty,
+                                                       &NoteForHelper);
+    Descriptor = Builder.CreateBitCast(Descriptor, PtrToInt8Ty);
+    Builder.CreateStore(Descriptor, Builder.CreateStructGEP(V, 4, "block.tmp"));
+  }
+
+  QualType BPT = BE->getType();
+  return Builder.CreateBitCast(V, ConvertType(BPT));
+}
+
+
+const llvm::Type *BlockModule::getBlockDescriptorType() {
+  if (BlockDescriptorType)
+    return BlockDescriptorType;
+
+  const llvm::Type *UnsignedLongTy =
+    getTypes().ConvertType(getContext().UnsignedLongTy);
+
+  // struct __block_descriptor {
+  //   unsigned long reserved;
+  //   unsigned long block_size;
+  // };
+  BlockDescriptorType = llvm::StructType::get(UnsignedLongTy->getContext(),
+                                              UnsignedLongTy,
+                                              UnsignedLongTy,
+                                              NULL);
+
+  getModule().addTypeName("struct.__block_descriptor",
+                          BlockDescriptorType);
+
+  return BlockDescriptorType;
+}
+
+const llvm::Type *BlockModule::getGenericBlockLiteralType() {
+  if (GenericBlockLiteralType)
+    return GenericBlockLiteralType;
+
+  const llvm::Type *BlockDescPtrTy =
+    llvm::PointerType::getUnqual(getBlockDescriptorType());
+
+  const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
+    getTypes().ConvertType(getContext().IntTy));
+
+  // struct __block_literal_generic {
+  //   void *__isa;
+  //   int __flags;
+  //   int __reserved;
+  //   void (*__invoke)(void *);
+  //   struct __block_descriptor *__descriptor;
+  //   // GNU runtime only:
+  //   const char *types;
+  // };
+  if (CGM.getContext().getLangOptions().BlockIntrospection)
+    GenericBlockLiteralType = llvm::StructType::get(IntTy->getContext(),
+                                                  PtrToInt8Ty,
+                                                  IntTy,
+                                                  IntTy,
+                                                  PtrToInt8Ty,
+                                                  BlockDescPtrTy,
+                                                  PtrToInt8Ty,
+                                                  NULL);
+  else
+    GenericBlockLiteralType = llvm::StructType::get(IntTy->getContext(),
+                                                  PtrToInt8Ty,
+                                                  IntTy,
+                                                  IntTy,
+                                                  PtrToInt8Ty,
+                                                  BlockDescPtrTy,
+                                                  NULL);
+
+  getModule().addTypeName("struct.__block_literal_generic",
+                          GenericBlockLiteralType);
+
+  return GenericBlockLiteralType;
+}
+
+const llvm::Type *BlockModule::getGenericExtendedBlockLiteralType() {
+  if (GenericExtendedBlockLiteralType)
+    return GenericExtendedBlockLiteralType;
+
+  const llvm::Type *BlockDescPtrTy =
+    llvm::PointerType::getUnqual(getBlockDescriptorType());
+
+  const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
+    getTypes().ConvertType(getContext().IntTy));
+
+  // struct __block_literal_generic {
+  //   void *__isa;
+  //   int __flags;
+  //   int __reserved;
+  //   void (*__invoke)(void *);
+  //   struct __block_descriptor *__descriptor;
+  //   void *__copy_func_helper_decl;
+  //   void *__destroy_func_decl;
+  // };
+  GenericExtendedBlockLiteralType = llvm::StructType::get(IntTy->getContext(),
+                                                          PtrToInt8Ty,
+                                                          IntTy,
+                                                          IntTy,
+                                                          PtrToInt8Ty,
+                                                          BlockDescPtrTy,
+                                                          PtrToInt8Ty,
+                                                          PtrToInt8Ty,
+                                                          NULL);
+
+  getModule().addTypeName("struct.__block_literal_extended_generic",
+                          GenericExtendedBlockLiteralType);
+
+  return GenericExtendedBlockLiteralType;
+}
+
+RValue CodeGenFunction::EmitBlockCallExpr(const CallExpr* E, 
+                                          ReturnValueSlot ReturnValue) {
+  const BlockPointerType *BPT =
+    E->getCallee()->getType()->getAs<BlockPointerType>();
+
+  llvm::Value *Callee = EmitScalarExpr(E->getCallee());
+
+  // Get a pointer to the generic block literal.
+  const llvm::Type *BlockLiteralTy =
+    llvm::PointerType::getUnqual(CGM.getGenericBlockLiteralType());
+
+  // Bitcast the callee to a block literal.
+  llvm::Value *BlockLiteral =
+    Builder.CreateBitCast(Callee, BlockLiteralTy, "block.literal");
+
+  // Get the function pointer from the literal.
+  llvm::Value *FuncPtr = Builder.CreateStructGEP(BlockLiteral, 3, "tmp");
+
+  BlockLiteral =
+    Builder.CreateBitCast(BlockLiteral,
+                          llvm::Type::getInt8PtrTy(VMContext),
+                          "tmp");
+
+  // Add the block literal.
+  QualType VoidPtrTy = getContext().getPointerType(getContext().VoidTy);
+  CallArgList Args;
+  Args.push_back(std::make_pair(RValue::get(BlockLiteral), VoidPtrTy));
+
+  QualType FnType = BPT->getPointeeType();
+
+  // And the rest of the arguments.
+  EmitCallArgs(Args, FnType->getAs<FunctionProtoType>(),
+               E->arg_begin(), E->arg_end());
+
+  // Load the function.
+  llvm::Value *Func = Builder.CreateLoad(FuncPtr, "tmp");
+
+  const FunctionType *FuncTy = FnType->getAs<FunctionType>();
+  QualType ResultType = FuncTy->getResultType();
+
+  const CGFunctionInfo &FnInfo =
+    CGM.getTypes().getFunctionInfo(ResultType, Args, FuncTy->getCallConv(),
+                                   FuncTy->getNoReturnAttr());
+
+  // Cast the function pointer to the right type.
+  const llvm::Type *BlockFTy =
+    CGM.getTypes().GetFunctionType(FnInfo, false);
+
+  const llvm::Type *BlockFTyPtr = llvm::PointerType::getUnqual(BlockFTy);
+  Func = Builder.CreateBitCast(Func, BlockFTyPtr);
+
+  // And call the block.
+  return EmitCall(FnInfo, Func, ReturnValue, Args);
+}
+
+CharUnits CodeGenFunction::AllocateBlockDecl(const BlockDeclRefExpr *E) {
+  const ValueDecl *VD = E->getDecl();
+  CharUnits &offset = BlockDecls[VD];
+
+  // See if we have already allocated an offset for this variable.
+  if (offset.isPositive())
+    return offset;
+
+  // Don't run the expensive check, unless we have to.
+  if (!BlockHasCopyDispose)
+    if (E->isByRef()
+        || BlockRequiresCopying(E->getType()))
+      BlockHasCopyDispose = true;
+
+  // if not, allocate one now.
+  offset = getBlockOffset(E);
+
+  return offset;
+}
+
+llvm::Value *CodeGenFunction::GetAddrOfBlockDecl(const BlockDeclRefExpr *E) {
+  const ValueDecl *VD = E->getDecl();
+  CharUnits offset = AllocateBlockDecl(E);
+  
+
+  llvm::Value *BlockLiteral = LoadBlockStruct();
+  llvm::Value *V = Builder.CreateGEP(BlockLiteral,
+                       llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext),
+                                                         offset.getQuantity()),
+                                     "block.literal");
+  if (E->isByRef()) {
+    const llvm::Type *PtrStructTy
+      = llvm::PointerType::get(BuildByRefType(VD), 0);
+    // The block literal will need a copy/destroy helper.
+    BlockHasCopyDispose = true;
+    
+    const llvm::Type *Ty = PtrStructTy;
+    Ty = llvm::PointerType::get(Ty, 0);
+    V = Builder.CreateBitCast(V, Ty);
+    V = Builder.CreateLoad(V);
+    V = Builder.CreateStructGEP(V, 1, "forwarding");
+    V = Builder.CreateLoad(V);
+    V = Builder.CreateBitCast(V, PtrStructTy);
+    V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD), 
+                                VD->getNameAsString());
+  } else {
+    const llvm::Type *Ty = CGM.getTypes().ConvertType(VD->getType());
+
+    Ty = llvm::PointerType::get(Ty, 0);
+    V = Builder.CreateBitCast(V, Ty);
+  }
+  return V;
+}
+
+void CodeGenFunction::BlockForwardSelf() {
+  const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
+  ImplicitParamDecl *SelfDecl = OMD->getSelfDecl();
+  llvm::Value *&DMEntry = LocalDeclMap[SelfDecl];
+  if (DMEntry)
+    return;
+  // FIXME - Eliminate BlockDeclRefExprs, clients don't need/want to care
+  BlockDeclRefExpr *BDRE = new (getContext())
+    BlockDeclRefExpr(SelfDecl,
+                     SelfDecl->getType(), SourceLocation(), false);
+  DMEntry = GetAddrOfBlockDecl(BDRE);
+}
+
+llvm::Constant *
+BlockModule::GetAddrOfGlobalBlock(const BlockExpr *BE, const char * n) {
+  // Generate the block descriptor.
+  const llvm::Type *UnsignedLongTy = Types.ConvertType(Context.UnsignedLongTy);
+  const llvm::IntegerType *IntTy = cast<llvm::IntegerType>(
+    getTypes().ConvertType(getContext().IntTy));
+
+  llvm::Constant *DescriptorFields[2];
+
+  // Reserved
+  DescriptorFields[0] = llvm::Constant::getNullValue(UnsignedLongTy);
+
+  // Block literal size. For global blocks we just use the size of the generic
+  // block literal struct.
+  CharUnits BlockLiteralSize = 
+    CGM.GetTargetTypeStoreSize(getGenericBlockLiteralType());
+  DescriptorFields[1] =
+    llvm::ConstantInt::get(UnsignedLongTy,BlockLiteralSize.getQuantity());
+
+  llvm::Constant *DescriptorStruct =
+    llvm::ConstantStruct::get(VMContext, &DescriptorFields[0], 2, false);
+
+  llvm::GlobalVariable *Descriptor =
+    new llvm::GlobalVariable(getModule(), DescriptorStruct->getType(), true,
+                             llvm::GlobalVariable::InternalLinkage,
+                             DescriptorStruct, "__block_descriptor_global");
+
+  int FieldCount = 5;
+  // Generate the constants for the block literal.
+  if (CGM.getContext().getLangOptions().BlockIntrospection)
+    FieldCount = 6;
+
+  std::vector<llvm::Constant*> LiteralFields(FieldCount);
+
+  CodeGenFunction::BlockInfo Info(0, n);
+  CharUnits subBlockSize; 
+  CharUnits subBlockAlign;
+  llvm::SmallVector<const Expr *, 8> subBlockDeclRefDecls;
+  bool subBlockHasCopyDispose = false;
+  llvm::DenseMap<const Decl*, llvm::Value*> LocalDeclMap;
+  llvm::Function *Fn
+    = CodeGenFunction(CGM).GenerateBlockFunction(BE, Info, 0, LocalDeclMap,
+                                                 subBlockSize,
+                                                 subBlockAlign,
+                                                 subBlockDeclRefDecls,
+                                                 subBlockHasCopyDispose);
+  assert(subBlockSize == BlockLiteralSize
+         && "no imports allowed for global block");
+
+  // isa
+  LiteralFields[0] = getNSConcreteGlobalBlock();
+
+  // Flags
+  LiteralFields[1] = CGM.getContext().getLangOptions().BlockIntrospection ?
+    llvm::ConstantInt::get(IntTy, BLOCK_IS_GLOBAL | BLOCK_HAS_DESCRIPTOR |
+            BLOCK_HAS_OBJC_TYPE) :
+    llvm::ConstantInt::get(IntTy, BLOCK_IS_GLOBAL | BLOCK_HAS_DESCRIPTOR);
+
+  // Reserved
+  LiteralFields[2] = llvm::Constant::getNullValue(IntTy);
+
+  // Function
+  LiteralFields[3] = Fn;
+
+  // Descriptor
+  LiteralFields[4] = Descriptor;
+  
+  // Type encoding
+  if (CGM.getContext().getLangOptions().BlockIntrospection) {
+    std::string BlockTypeEncoding;
+    CGM.getContext().getObjCEncodingForBlock(BE, BlockTypeEncoding);
+
+    LiteralFields[5] = CGM.GetAddrOfConstantCString(BlockTypeEncoding);
+  }
+
+  llvm::Constant *BlockLiteralStruct =
+    llvm::ConstantStruct::get(VMContext, LiteralFields, false);
+
+  llvm::GlobalVariable *BlockLiteral =
+    new llvm::GlobalVariable(getModule(), BlockLiteralStruct->getType(), true,
+                             llvm::GlobalVariable::InternalLinkage,
+                             BlockLiteralStruct, "__block_literal_global");
+
+  return BlockLiteral;
+}
+
+llvm::Value *CodeGenFunction::LoadBlockStruct() {
+  llvm::Value *V = Builder.CreateLoad(LocalDeclMap[getBlockStructDecl()],
+                                      "self");
+  // For now, we codegen based upon byte offsets.
+  return Builder.CreateBitCast(V, PtrToInt8Ty);
+}
+
+llvm::Function *
+CodeGenFunction::GenerateBlockFunction(const BlockExpr *BExpr,
+                                       const BlockInfo& Info,
+                                       const Decl *OuterFuncDecl,
+                                  llvm::DenseMap<const Decl*, llvm::Value*> ldm,
+                                       CharUnits &Size,
+                                       CharUnits &Align,
+                       llvm::SmallVector<const Expr *, 8> &subBlockDeclRefDecls,
+                                       bool &subBlockHasCopyDispose) {
+
+  // Check if we should generate debug info for this block.
+  if (CGM.getDebugInfo())
+    DebugInfo = CGM.getDebugInfo();
+
+  // Arrange for local static and local extern declarations to appear
+  // to be local to this function as well, as they are directly referenced
+  // in a block.
+  for (llvm::DenseMap<const Decl *, llvm::Value*>::iterator i = ldm.begin();
+       i != ldm.end();
+       ++i) {
+    const VarDecl *VD = dyn_cast<VarDecl>(i->first);
+
+    if (VD->getStorageClass() == VarDecl::Static || VD->hasExternalStorage())
+      LocalDeclMap[VD] = i->second;
+  }
+
+  BlockOffset = 
+      CGM.GetTargetTypeStoreSize(CGM.getGenericBlockLiteralType());
+  BlockAlign = getContext().getTypeAlignInChars(getContext().VoidPtrTy);
+
+  const FunctionType *BlockFunctionType = BExpr->getFunctionType();
+  QualType ResultType;
+  CallingConv CC = BlockFunctionType->getCallConv();
+  bool NoReturn = BlockFunctionType->getNoReturnAttr();
+  bool IsVariadic;
+  if (const FunctionProtoType *FTy =
+      dyn_cast<FunctionProtoType>(BlockFunctionType)) {
+    ResultType = FTy->getResultType();
+    IsVariadic = FTy->isVariadic();
+  } else {
+    // K&R style block.
+    ResultType = BlockFunctionType->getResultType();
+    IsVariadic = false;
+  }
+
+  FunctionArgList Args;
+
+  CurFuncDecl = OuterFuncDecl;
+
+  const BlockDecl *BD = BExpr->getBlockDecl();
+
+  IdentifierInfo *II = &CGM.getContext().Idents.get(".block_descriptor");
+
+  // Allocate all BlockDeclRefDecls, so we can calculate the right ParmTy below.
+  AllocateAllBlockDeclRefs(Info, this);
+
+  QualType ParmTy = getContext().getBlockParmType(BlockHasCopyDispose,
+                                                  BlockDeclRefDecls);
+  // FIXME: This leaks
+  ImplicitParamDecl *SelfDecl =
+    ImplicitParamDecl::Create(getContext(), 0,
+                              SourceLocation(), II,
+                              ParmTy);
+
+  Args.push_back(std::make_pair(SelfDecl, SelfDecl->getType()));
+  BlockStructDecl = SelfDecl;
+
+  for (BlockDecl::param_const_iterator i = BD->param_begin(),
+       e = BD->param_end(); i != e; ++i)
+    Args.push_back(std::make_pair(*i, (*i)->getType()));
+
+  const CGFunctionInfo &FI =
+    CGM.getTypes().getFunctionInfo(ResultType, Args, CC, NoReturn);
+
+  CodeGenTypes &Types = CGM.getTypes();
+  const llvm::FunctionType *LTy = Types.GetFunctionType(FI, IsVariadic);
+
+  llvm::Function *Fn =
+    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
+                           llvm::Twine("__") + Info.Name + "_block_invoke_",
+                           &CGM.getModule());
+
+  CGM.SetInternalFunctionAttributes(BD, Fn, FI);
+
+  StartFunction(BD, ResultType, Fn, Args,
+                BExpr->getBody()->getLocEnd());
+
+  CurFuncDecl = OuterFuncDecl;
+  CurCodeDecl = BD;
+
+  // Save a spot to insert the debug information for all the BlockDeclRefDecls.
+  llvm::BasicBlock *entry = Builder.GetInsertBlock();
+  llvm::BasicBlock::iterator entry_ptr = Builder.GetInsertPoint();
+  --entry_ptr;
+
+  EmitStmt(BExpr->getBody());
+
+  // Remember where we were...
+  llvm::BasicBlock *resume = Builder.GetInsertBlock();
+
+  // Go back to the entry.
+  ++entry_ptr;
+  Builder.SetInsertPoint(entry, entry_ptr);
+
+  if (CGDebugInfo *DI = getDebugInfo()) {
+    // Emit debug information for all the BlockDeclRefDecls.
+    for (unsigned i = 0, e = BlockDeclRefDecls.size(); i != e; ++i) {
+      if (const BlockDeclRefExpr *BDRE = 
+            dyn_cast<BlockDeclRefExpr>(BlockDeclRefDecls[i])) {
+        const ValueDecl *D = BDRE->getDecl();
+        DI->setLocation(D->getLocation());
+        DI->EmitDeclareOfBlockDeclRefVariable(BDRE,
+                                             LocalDeclMap[getBlockStructDecl()],
+                                              Builder, this);
+      }
+    }
+  }
+  // And resume where we left off.
+  if (resume == 0)
+    Builder.ClearInsertionPoint();
+  else
+    Builder.SetInsertPoint(resume);
+
+  FinishFunction(cast<CompoundStmt>(BExpr->getBody())->getRBracLoc());
+
+  // The runtime needs a minimum alignment of a void *.
+  CharUnits MinAlign = getContext().getTypeAlignInChars(getContext().VoidPtrTy);
+  BlockOffset = CharUnits::fromQuantity(
+      llvm::RoundUpToAlignment(BlockOffset.getQuantity(), 
+                               MinAlign.getQuantity()));
+
+  Size = BlockOffset;
+  Align = BlockAlign;
+  subBlockDeclRefDecls = BlockDeclRefDecls;
+  subBlockHasCopyDispose |= BlockHasCopyDispose;
+  return Fn;
+}
+
+CharUnits BlockFunction::getBlockOffset(const BlockDeclRefExpr *BDRE) {
+  const ValueDecl *D = dyn_cast<ValueDecl>(BDRE->getDecl());
+
+  CharUnits Size = getContext().getTypeSizeInChars(D->getType());
+  CharUnits Align = getContext().getDeclAlign(D);
+
+  if (BDRE->isByRef()) {
+    Size = getContext().getTypeSizeInChars(getContext().VoidPtrTy);
+    Align = getContext().getTypeAlignInChars(getContext().VoidPtrTy);
+  }
+
+  assert ((Align.isPositive()) && "alignment must be 1 byte or more");
+
+  CharUnits OldOffset = BlockOffset;
+
+  // Ensure proper alignment, even if it means we have to have a gap
+  BlockOffset = CharUnits::fromQuantity(
+      llvm::RoundUpToAlignment(BlockOffset.getQuantity(), Align.getQuantity()));
+  BlockAlign = std::max(Align, BlockAlign);
+
+  CharUnits Pad = BlockOffset - OldOffset;
+  if (Pad.isPositive()) {
+    llvm::ArrayType::get(llvm::Type::getInt8Ty(VMContext), Pad.getQuantity());
+    QualType PadTy = getContext().getConstantArrayType(getContext().CharTy,
+                                                       llvm::APInt(32, 
+                                                         Pad.getQuantity()),
+                                                       ArrayType::Normal, 0);
+    ValueDecl *PadDecl = VarDecl::Create(getContext(), 0, SourceLocation(),
+                                         0, QualType(PadTy), 0, VarDecl::None);
+    Expr *E;
+    E = new (getContext()) DeclRefExpr(PadDecl, PadDecl->getType(),
+                                       SourceLocation());
+    BlockDeclRefDecls.push_back(E);
+  }
+  BlockDeclRefDecls.push_back(BDRE);
+
+  BlockOffset += Size;
+  return BlockOffset-Size;
+}
+
+llvm::Constant *BlockFunction::
+GenerateCopyHelperFunction(bool BlockHasCopyDispose, const llvm::StructType *T,
+                           std::vector<HelperInfo> *NoteForHelperp) {
+  QualType R = getContext().VoidTy;
+
+  FunctionArgList Args;
+  // FIXME: This leaks
+  ImplicitParamDecl *Dst =
+    ImplicitParamDecl::Create(getContext(), 0,
+                              SourceLocation(), 0,
+                              getContext().getPointerType(getContext().VoidTy));
+  Args.push_back(std::make_pair(Dst, Dst->getType()));
+  ImplicitParamDecl *Src =
+    ImplicitParamDecl::Create(getContext(), 0,
+                              SourceLocation(), 0,
+                              getContext().getPointerType(getContext().VoidTy));
+  Args.push_back(std::make_pair(Src, Src->getType()));
+
+  const CGFunctionInfo &FI =
+    CGM.getTypes().getFunctionInfo(R, Args, CC_Default, false);
+
+  // FIXME: We'd like to put these into a mergable by content, with
+  // internal linkage.
+  CodeGenTypes &Types = CGM.getTypes();
+  const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
+
+  llvm::Function *Fn =
+    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
+                           "__copy_helper_block_", &CGM.getModule());
+
+  IdentifierInfo *II
+    = &CGM.getContext().Idents.get("__copy_helper_block_");
+
+  FunctionDecl *FD = FunctionDecl::Create(getContext(),
+                                          getContext().getTranslationUnitDecl(),
+                                          SourceLocation(), II, R, 0,
+                                          FunctionDecl::Static, false,
+                                          true);
+  CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
+
+  llvm::Value *SrcObj = CGF.GetAddrOfLocalVar(Src);
+  llvm::Type *PtrPtrT;
+
+  if (NoteForHelperp) {
+    std::vector<HelperInfo> &NoteForHelper = *NoteForHelperp;
+
+    PtrPtrT = llvm::PointerType::get(llvm::PointerType::get(T, 0), 0);
+    SrcObj = Builder.CreateBitCast(SrcObj, PtrPtrT);
+    SrcObj = Builder.CreateLoad(SrcObj);
+
+    llvm::Value *DstObj = CGF.GetAddrOfLocalVar(Dst);
+    llvm::Type *PtrPtrT;
+    PtrPtrT = llvm::PointerType::get(llvm::PointerType::get(T, 0), 0);
+    DstObj = Builder.CreateBitCast(DstObj, PtrPtrT);
+    DstObj = Builder.CreateLoad(DstObj);
+
+    for (unsigned i=0; i < NoteForHelper.size(); ++i) {
+      int flag = NoteForHelper[i].flag;
+      int index = NoteForHelper[i].index;
+
+      if ((NoteForHelper[i].flag & BLOCK_FIELD_IS_BYREF)
+          || NoteForHelper[i].RequiresCopying) {
+        llvm::Value *Srcv = SrcObj;
+        Srcv = Builder.CreateStructGEP(Srcv, index);
+        Srcv = Builder.CreateBitCast(Srcv,
+                                     llvm::PointerType::get(PtrToInt8Ty, 0));
+        Srcv = Builder.CreateLoad(Srcv);
+
+        llvm::Value *Dstv = Builder.CreateStructGEP(DstObj, index);
+        Dstv = Builder.CreateBitCast(Dstv, PtrToInt8Ty);
+
+        llvm::Value *N = llvm::ConstantInt::get(
+              llvm::Type::getInt32Ty(T->getContext()), flag);
+        llvm::Value *F = getBlockObjectAssign();
+        Builder.CreateCall3(F, Dstv, Srcv, N);
+      }
+    }
+  }
+
+  CGF.FinishFunction();
+
+  return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
+}
+
+llvm::Constant *BlockFunction::
+GenerateDestroyHelperFunction(bool BlockHasCopyDispose,
+                              const llvm::StructType* T,
+                              std::vector<HelperInfo> *NoteForHelperp) {
+  QualType R = getContext().VoidTy;
+
+  FunctionArgList Args;
+  // FIXME: This leaks
+  ImplicitParamDecl *Src =
+    ImplicitParamDecl::Create(getContext(), 0,
+                              SourceLocation(), 0,
+                              getContext().getPointerType(getContext().VoidTy));
+
+  Args.push_back(std::make_pair(Src, Src->getType()));
+
+  const CGFunctionInfo &FI =
+    CGM.getTypes().getFunctionInfo(R, Args, CC_Default, false);
+
+  // FIXME: We'd like to put these into a mergable by content, with
+  // internal linkage.
+  CodeGenTypes &Types = CGM.getTypes();
+  const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
+
+  llvm::Function *Fn =
+    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
+                           "__destroy_helper_block_", &CGM.getModule());
+
+  IdentifierInfo *II
+    = &CGM.getContext().Idents.get("__destroy_helper_block_");
+
+  FunctionDecl *FD = FunctionDecl::Create(getContext(),
+                                          getContext().getTranslationUnitDecl(),
+                                          SourceLocation(), II, R, 0,
+                                          FunctionDecl::Static, false,
+                                          true);
+  CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
+
+  if (NoteForHelperp) {
+    std::vector<HelperInfo> &NoteForHelper = *NoteForHelperp;
+
+    llvm::Value *SrcObj = CGF.GetAddrOfLocalVar(Src);
+    llvm::Type *PtrPtrT;
+    PtrPtrT = llvm::PointerType::get(llvm::PointerType::get(T, 0), 0);
+    SrcObj = Builder.CreateBitCast(SrcObj, PtrPtrT);
+    SrcObj = Builder.CreateLoad(SrcObj);
+
+    for (unsigned i=0; i < NoteForHelper.size(); ++i) {
+      int flag = NoteForHelper[i].flag;
+      int index = NoteForHelper[i].index;
+
+      if ((NoteForHelper[i].flag & BLOCK_FIELD_IS_BYREF)
+          || NoteForHelper[i].RequiresCopying) {
+        llvm::Value *Srcv = SrcObj;
+        Srcv = Builder.CreateStructGEP(Srcv, index);
+        Srcv = Builder.CreateBitCast(Srcv,
+                                     llvm::PointerType::get(PtrToInt8Ty, 0));
+        Srcv = Builder.CreateLoad(Srcv);
+
+        BuildBlockRelease(Srcv, flag);
+      }
+    }
+  }
+
+  CGF.FinishFunction();
+
+  return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
+}
+
+llvm::Constant *BlockFunction::BuildCopyHelper(const llvm::StructType *T,
+                                       std::vector<HelperInfo> *NoteForHelper) {
+  return CodeGenFunction(CGM).GenerateCopyHelperFunction(BlockHasCopyDispose,
+                                                         T, NoteForHelper);
+}
+
+llvm::Constant *BlockFunction::BuildDestroyHelper(const llvm::StructType *T,
+                                      std::vector<HelperInfo> *NoteForHelperp) {
+  return CodeGenFunction(CGM).GenerateDestroyHelperFunction(BlockHasCopyDispose,
+                                                            T, NoteForHelperp);
+}
+
+llvm::Constant *BlockFunction::
+GeneratebyrefCopyHelperFunction(const llvm::Type *T, int flag) {
+  QualType R = getContext().VoidTy;
+
+  FunctionArgList Args;
+  // FIXME: This leaks
+  ImplicitParamDecl *Dst =
+    ImplicitParamDecl::Create(getContext(), 0,
+                              SourceLocation(), 0,
+                              getContext().getPointerType(getContext().VoidTy));
+  Args.push_back(std::make_pair(Dst, Dst->getType()));
+
+  // FIXME: This leaks
+  ImplicitParamDecl *Src =
+    ImplicitParamDecl::Create(getContext(), 0,
+                              SourceLocation(), 0,
+                              getContext().getPointerType(getContext().VoidTy));
+  Args.push_back(std::make_pair(Src, Src->getType()));
+
+  const CGFunctionInfo &FI =
+    CGM.getTypes().getFunctionInfo(R, Args, CC_Default, false);
+
+  CodeGenTypes &Types = CGM.getTypes();
+  const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
+
+  // FIXME: We'd like to put these into a mergable by content, with
+  // internal linkage.
+  llvm::Function *Fn =
+    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
+                           "__Block_byref_id_object_copy_", &CGM.getModule());
+
+  IdentifierInfo *II
+    = &CGM.getContext().Idents.get("__Block_byref_id_object_copy_");
+
+  FunctionDecl *FD = FunctionDecl::Create(getContext(),
+                                          getContext().getTranslationUnitDecl(),
+                                          SourceLocation(), II, R, 0,
+                                          FunctionDecl::Static, false,
+                                          true);
+  CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
+
+  // dst->x
+  llvm::Value *V = CGF.GetAddrOfLocalVar(Dst);
+  V = Builder.CreateBitCast(V, llvm::PointerType::get(T, 0));
+  V = Builder.CreateLoad(V);
+  V = Builder.CreateStructGEP(V, 6, "x");
+  llvm::Value *DstObj = Builder.CreateBitCast(V, PtrToInt8Ty);
+
+  // src->x
+  V = CGF.GetAddrOfLocalVar(Src);
+  V = Builder.CreateLoad(V);
+  V = Builder.CreateBitCast(V, T);
+  V = Builder.CreateStructGEP(V, 6, "x");
+  V = Builder.CreateBitCast(V, llvm::PointerType::get(PtrToInt8Ty, 0));
+  llvm::Value *SrcObj = Builder.CreateLoad(V);
+
+  flag |= BLOCK_BYREF_CALLER;
+
+  llvm::Value *N = llvm::ConstantInt::get(
+          llvm::Type::getInt32Ty(T->getContext()), flag);
+  llvm::Value *F = getBlockObjectAssign();
+  Builder.CreateCall3(F, DstObj, SrcObj, N);
+
+  CGF.FinishFunction();
+
+  return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
+}
+
+llvm::Constant *
+BlockFunction::GeneratebyrefDestroyHelperFunction(const llvm::Type *T,
+                                                  int flag) {
+  QualType R = getContext().VoidTy;
+
+  FunctionArgList Args;
+  // FIXME: This leaks
+  ImplicitParamDecl *Src =
+    ImplicitParamDecl::Create(getContext(), 0,
+                              SourceLocation(), 0,
+                              getContext().getPointerType(getContext().VoidTy));
+
+  Args.push_back(std::make_pair(Src, Src->getType()));
+
+  const CGFunctionInfo &FI =
+    CGM.getTypes().getFunctionInfo(R, Args, CC_Default, false);
+
+  CodeGenTypes &Types = CGM.getTypes();
+  const llvm::FunctionType *LTy = Types.GetFunctionType(FI, false);
+
+  // FIXME: We'd like to put these into a mergable by content, with
+  // internal linkage.
+  llvm::Function *Fn =
+    llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
+                           "__Block_byref_id_object_dispose_",
+                           &CGM.getModule());
+
+  IdentifierInfo *II
+    = &CGM.getContext().Idents.get("__Block_byref_id_object_dispose_");
+
+  FunctionDecl *FD = FunctionDecl::Create(getContext(),
+                                          getContext().getTranslationUnitDecl(),
+                                          SourceLocation(), II, R, 0,
+                                          FunctionDecl::Static, false,
+                                          true);
+  CGF.StartFunction(FD, R, Fn, Args, SourceLocation());
+
+  llvm::Value *V = CGF.GetAddrOfLocalVar(Src);
+  V = Builder.CreateBitCast(V, llvm::PointerType::get(T, 0));
+  V = Builder.CreateLoad(V);
+  V = Builder.CreateStructGEP(V, 6, "x");
+  V = Builder.CreateBitCast(V, llvm::PointerType::get(PtrToInt8Ty, 0));
+  V = Builder.CreateLoad(V);
+
+  flag |= BLOCK_BYREF_CALLER;
+  BuildBlockRelease(V, flag);
+  CGF.FinishFunction();
+
+  return llvm::ConstantExpr::getBitCast(Fn, PtrToInt8Ty);
+}
+
+llvm::Constant *BlockFunction::BuildbyrefCopyHelper(const llvm::Type *T,
+                                                    int Flag, unsigned Align) {
+  // All alignments below that of pointer alignment collapse down to just
+  // pointer alignment, as we always have at least that much alignment to begin
+  // with.
+  Align /= unsigned(CGF.Target.getPointerAlign(0)/8);
+  
+  // As an optimization, we only generate a single function of each kind we
+  // might need.  We need a different one for each alignment and for each
+  // setting of flags.  We mix Align and flag to get the kind.
+  uint64_t Kind = (uint64_t)Align*BLOCK_BYREF_CURRENT_MAX + Flag;
+  llvm::Constant *&Entry = CGM.AssignCache[Kind];
+  if (Entry)
+    return Entry;
+  return Entry = CodeGenFunction(CGM).GeneratebyrefCopyHelperFunction(T, Flag);
+}
+
+llvm::Constant *BlockFunction::BuildbyrefDestroyHelper(const llvm::Type *T,
+                                                       int Flag,
+                                                       unsigned Align) {
+  // All alignments below that of pointer alignment collpase down to just
+  // pointer alignment, as we always have at least that much alignment to begin
+  // with.
+  Align /= unsigned(CGF.Target.getPointerAlign(0)/8);
+  
+  // As an optimization, we only generate a single function of each kind we
+  // might need.  We need a different one for each alignment and for each
+  // setting of flags.  We mix Align and flag to get the kind.
+  uint64_t Kind = (uint64_t)Align*BLOCK_BYREF_CURRENT_MAX + Flag;
+  llvm::Constant *&Entry = CGM.DestroyCache[Kind];
+  if (Entry)
+    return Entry;
+  return Entry=CodeGenFunction(CGM).GeneratebyrefDestroyHelperFunction(T, Flag);
+}
+
+llvm::Value *BlockFunction::getBlockObjectDispose() {
+  if (CGM.BlockObjectDispose == 0) {
+    const llvm::FunctionType *FTy;
+    std::vector<const llvm::Type*> ArgTys;
+    const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext);
+    ArgTys.push_back(PtrToInt8Ty);
+    ArgTys.push_back(llvm::Type::getInt32Ty(VMContext));
+    FTy = llvm::FunctionType::get(ResultType, ArgTys, false);
+    CGM.BlockObjectDispose
+      = CGM.CreateRuntimeFunction(FTy, "_Block_object_dispose");
+  }
+  return CGM.BlockObjectDispose;
+}
+
+llvm::Value *BlockFunction::getBlockObjectAssign() {
+  if (CGM.BlockObjectAssign == 0) {
+    const llvm::FunctionType *FTy;
+    std::vector<const llvm::Type*> ArgTys;
+    const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext);
+    ArgTys.push_back(PtrToInt8Ty);
+    ArgTys.push_back(PtrToInt8Ty);
+    ArgTys.push_back(llvm::Type::getInt32Ty(VMContext));
+    FTy = llvm::FunctionType::get(ResultType, ArgTys, false);
+    CGM.BlockObjectAssign
+      = CGM.CreateRuntimeFunction(FTy, "_Block_object_assign");
+  }
+  return CGM.BlockObjectAssign;
+}
+
+void BlockFunction::BuildBlockRelease(llvm::Value *V, int flag) {
+  llvm::Value *F = getBlockObjectDispose();
+  llvm::Value *N;
+  V = Builder.CreateBitCast(V, PtrToInt8Ty);
+  N = llvm::ConstantInt::get(llvm::Type::getInt32Ty(V->getContext()), flag);
+  Builder.CreateCall2(F, V, N);
+}
+
+ASTContext &BlockFunction::getContext() const { return CGM.getContext(); }
+
+BlockFunction::BlockFunction(CodeGenModule &cgm, CodeGenFunction &cgf,
+                             CGBuilderTy &B)
+  : CGM(cgm), CGF(cgf), VMContext(cgm.getLLVMContext()), Builder(B) {
+  PtrToInt8Ty = llvm::PointerType::getUnqual(
+            llvm::Type::getInt8Ty(VMContext));
+
+  BlockHasCopyDispose = false;
+}