Update clang to r84119.

1 files changed, 557 insertions, 0 deletions

diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp
new file mode 100644
index 0000000..41f7eef
--- /dev/null
+++ b/lib/CodeGen/CGVtable.cpp
@@ -0,0 +1,557 @@
+//===--- CGVtable.cpp - Emit LLVM Code for C++ vtables --------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code dealing with C++ code generation of virtual tables.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CodeGenModule.h"
+#include "CodeGenFunction.h"
+
+#include "clang/AST/RecordLayout.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+class VtableBuilder {
+public:
+  /// Index_t - Vtable index type.
+  typedef uint64_t Index_t;
+private:
+  std::vector<llvm::Constant *> &methods;
+  std::vector<llvm::Constant *> submethods;
+  llvm::Type *Ptr8Ty;
+  /// Class - The most derived class that this vtable is being built for.
+  const CXXRecordDecl *Class;
+  /// BLayout - Layout for the most derived class that this vtable is being
+  /// built for.
+  const ASTRecordLayout &BLayout;
+  llvm::SmallSet<const CXXRecordDecl *, 32> IndirectPrimary;
+  llvm::SmallSet<const CXXRecordDecl *, 32> SeenVBase;
+  llvm::Constant *rtti;
+  llvm::LLVMContext &VMContext;
+  CodeGenModule &CGM;  // Per-module state.
+  /// Index - Maps a method decl into a vtable index.  Useful for virtual
+  /// dispatch codegen.
+  llvm::DenseMap<const CXXMethodDecl *, Index_t> Index;
+  llvm::DenseMap<const CXXMethodDecl *, Index_t> VCall;
+  llvm::DenseMap<const CXXMethodDecl *, Index_t> VCallOffset;
+  llvm::DenseMap<const CXXRecordDecl *, Index_t> VBIndex;
+  typedef std::pair<Index_t, Index_t>  CallOffset;
+  typedef llvm::DenseMap<const CXXMethodDecl *, CallOffset> Thunks_t;
+  Thunks_t Thunks;
+  typedef llvm::DenseMap<const CXXMethodDecl *,
+                         std::pair<std::pair<CallOffset, CallOffset>,
+                                   CanQualType> > CovariantThunks_t;
+  CovariantThunks_t CovariantThunks;
+  std::vector<Index_t> VCalls;
+  typedef CXXRecordDecl::method_iterator method_iter;
+  // FIXME: Linkage should follow vtable
+  const bool Extern;
+  const uint32_t LLVMPointerWidth;
+  Index_t extra;
+public:
+  VtableBuilder(std::vector<llvm::Constant *> &meth,
+                const CXXRecordDecl *c,
+                CodeGenModule &cgm)
+    : methods(meth), Class(c), BLayout(cgm.getContext().getASTRecordLayout(c)),
+      rtti(cgm.GenerateRtti(c)), VMContext(cgm.getModule().getContext()),
+      CGM(cgm), Extern(true),
+      LLVMPointerWidth(cgm.getContext().Target.getPointerWidth(0)) {
+    Ptr8Ty = llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext), 0);
+  }
+
+  llvm::DenseMap<const CXXMethodDecl *, Index_t> &getIndex() { return Index; }
+  llvm::DenseMap<const CXXRecordDecl *, Index_t> &getVBIndex()
+    { return VBIndex; }
+
+  llvm::Constant *wrap(Index_t i) {
+    llvm::Constant *m;
+    m = llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), i);
+    return llvm::ConstantExpr::getIntToPtr(m, Ptr8Ty);
+  }
+
+  llvm::Constant *wrap(llvm::Constant *m) {
+    return llvm::ConstantExpr::getBitCast(m, Ptr8Ty);
+  }
+
+  void GenerateVBaseOffsets(std::vector<llvm::Constant *> &offsets,
+                            const CXXRecordDecl *RD, uint64_t Offset,
+                            bool updateVBIndex, Index_t current_vbindex) {
+    for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
+           e = RD->bases_end(); i != e; ++i) {
+      const CXXRecordDecl *Base =
+        cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
+      Index_t next_vbindex = current_vbindex;
+      if (i->isVirtual() && !SeenVBase.count(Base)) {
+        SeenVBase.insert(Base);
+        int64_t BaseOffset = -(Offset/8) + BLayout.getVBaseClassOffset(Base)/8;
+        llvm::Constant *m = wrap(BaseOffset);
+        m = wrap((0?700:0) + BaseOffset);
+        if (updateVBIndex) {
+          next_vbindex = (ssize_t)(-(offsets.size()*LLVMPointerWidth/8)
+                                   - 3*LLVMPointerWidth/8);
+          VBIndex[Base] = next_vbindex;
+        }
+        offsets.push_back(m);
+      }
+      // We also record offsets for non-virtual bases to closest enclosing
+      // virtual base.  We do this so that we don't have to search
+      // for the nearst virtual base class when generating thunks.
+      if (updateVBIndex && VBIndex.count(Base) == 0)
+        VBIndex[Base] = next_vbindex;
+      GenerateVBaseOffsets(offsets, Base, Offset, updateVBIndex, next_vbindex);
+    }
+  }
+
+  void StartNewTable() {
+    SeenVBase.clear();
+  }
+
+  Index_t VBlookup(CXXRecordDecl *D, CXXRecordDecl *B);
+
+  /// getVbaseOffset - Returns the index into the vtable for the virtual base
+  /// offset for the given (B) virtual base of the derived class D.
+  Index_t getVbaseOffset(QualType qB, QualType qD) {
+    qD = qD->getAs<PointerType>()->getPointeeType();
+    qB = qB->getAs<PointerType>()->getPointeeType();
+    CXXRecordDecl *D = cast<CXXRecordDecl>(qD->getAs<RecordType>()->getDecl());
+    CXXRecordDecl *B = cast<CXXRecordDecl>(qB->getAs<RecordType>()->getDecl());
+    if (D != Class)
+      return VBlookup(D, B);
+    llvm::DenseMap<const CXXRecordDecl *, Index_t>::iterator i;
+    i = VBIndex.find(B);
+    if (i != VBIndex.end())
+      return i->second;
+
+    assert(false && "FIXME: Base not found");
+    return 0;
+  }
+
+  bool OverrideMethod(const CXXMethodDecl *MD, llvm::Constant *m,
+                      bool MorallyVirtual, Index_t Offset) {
+    typedef CXXMethodDecl::method_iterator meth_iter;
+
+    // FIXME: Don't like the nested loops.  For very large inheritance
+    // heirarchies we could have a table on the side with the final overridder
+    // and just replace each instance of an overridden method once.  Would be
+    // nice to measure the cost/benefit on real code.
+
+    for (meth_iter mi = MD->begin_overridden_methods(),
+           e = MD->end_overridden_methods();
+         mi != e; ++mi) {
+      const CXXMethodDecl *OMD = *mi;
+      llvm::Constant *om;
+      om = CGM.GetAddrOfFunction(OMD, Ptr8Ty);
+      om = llvm::ConstantExpr::getBitCast(om, Ptr8Ty);
+
+      for (Index_t i = 0, e = submethods.size();
+           i != e; ++i) {
+        // FIXME: begin_overridden_methods might be too lax, covariance */
+        if (submethods[i] != om)
+          continue;
+        QualType nc_oret = OMD->getType()->getAs<FunctionType>()->getResultType();
+        CanQualType oret = CGM.getContext().getCanonicalType(nc_oret);
+        QualType nc_ret = MD->getType()->getAs<FunctionType>()->getResultType();
+        CanQualType ret = CGM.getContext().getCanonicalType(nc_ret);
+        CallOffset ReturnOffset = std::make_pair(0, 0);
+        if (oret != ret) {
+          // FIXME: calculate offsets for covariance
+          Index_t nv = 0;
+          if (CovariantThunks.count(OMD)) {
+            oret = CovariantThunks[OMD].second;
+            CovariantThunks.erase(OMD);
+          }
+          ReturnOffset = std::make_pair(nv, getVbaseOffset(oret, ret));
+        }
+        Index[MD] = i;
+        submethods[i] = m;
+
+        Thunks.erase(OMD);
+        if (MorallyVirtual) {
+          Index_t &idx = VCall[OMD];
+          if (idx == 0) {
+            VCallOffset[MD] = Offset/8;
+            idx = VCalls.size()+1;
+            VCalls.push_back(0);
+          } else {
+            VCallOffset[MD] = VCallOffset[OMD];
+            VCalls[idx-1] = -VCallOffset[OMD] + Offset/8;
+          }
+          VCall[MD] = idx;
+          CallOffset ThisOffset;
+          // FIXME: calculate non-virtual offset
+          ThisOffset = std::make_pair(0, -((idx+extra+2)*LLVMPointerWidth/8));
+          if (ReturnOffset.first || ReturnOffset.second)
+            CovariantThunks[MD] = std::make_pair(std::make_pair(ThisOffset,
+                                                                ReturnOffset),
+                                                 oret);
+          else
+            Thunks[MD] = ThisOffset;
+          return true;
+        }
+
+        // FIXME: finish off
+        int64_t O = VCallOffset[OMD] - Offset/8;
+        if (O || ReturnOffset.first || ReturnOffset.second) {
+          CallOffset ThisOffset = std::make_pair(O, 0);
+          
+          if (ReturnOffset.first || ReturnOffset.second)
+            CovariantThunks[MD] = std::make_pair(std::make_pair(ThisOffset,
+                                                                ReturnOffset),
+                                                 oret);
+          else
+            Thunks[MD] = ThisOffset;
+        }
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  void InstallThunks() {
+    for (Thunks_t::iterator i = Thunks.begin(), e = Thunks.end();
+         i != e; ++i) {
+      const CXXMethodDecl *MD = i->first;
+      Index_t idx = Index[MD];
+      Index_t nv_O = i->second.first;
+      Index_t v_O = i->second.second;
+      submethods[idx] = CGM.BuildThunk(MD, Extern, nv_O, v_O);
+    }
+    Thunks.clear();
+    for (CovariantThunks_t::iterator i = CovariantThunks.begin(),
+           e = CovariantThunks.end();
+         i != e; ++i) {
+      const CXXMethodDecl *MD = i->first;
+      Index_t idx = Index[MD];
+      Index_t nv_t = i->second.first.first.first;
+      Index_t v_t = i->second.first.first.second;
+      Index_t nv_r = i->second.first.second.first;
+      Index_t v_r = i->second.first.second.second;
+      submethods[idx] = CGM.BuildCovariantThunk(MD, Extern, nv_t, v_t, nv_r,
+                                                v_r);
+    }
+    CovariantThunks.clear();
+  }
+
+  void OverrideMethods(std::vector<std::pair<const CXXRecordDecl *,
+                       int64_t> > *Path, bool MorallyVirtual) {
+      for (std::vector<std::pair<const CXXRecordDecl *,
+             int64_t> >::reverse_iterator i =Path->rbegin(),
+           e = Path->rend(); i != e; ++i) {
+      const CXXRecordDecl *RD = i->first;
+      int64_t Offset = i->second;
+      for (method_iter mi = RD->method_begin(), me = RD->method_end(); mi != me;
+           ++mi) {
+        if (!mi->isVirtual())
+          continue;
+
+        const CXXMethodDecl *MD = *mi;
+        llvm::Constant *m = 0;
+        if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD))
+          m = wrap(CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete));
+        else {
+          const FunctionProtoType *FPT = 
+            MD->getType()->getAs<FunctionProtoType>();
+          const llvm::Type *Ty =
+            CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD),
+                                           FPT->isVariadic());
+          
+          m = wrap(CGM.GetAddrOfFunction(MD, Ty));
+        }
+
+        OverrideMethod(MD, m, MorallyVirtual, Offset);
+      }
+    }
+  }
+
+  void AddMethod(const CXXMethodDecl *MD, bool MorallyVirtual, Index_t Offset) {
+    llvm::Constant *m = 0;
+    if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD))
+      m = wrap(CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete));
+    else {
+      const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
+      const llvm::Type *Ty =
+        CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD),
+                                       FPT->isVariadic());
+      
+      m = wrap(CGM.GetAddrOfFunction(MD, Ty));
+    }
+    
+    // If we can find a previously allocated slot for this, reuse it.
+    if (OverrideMethod(MD, m, MorallyVirtual, Offset))
+      return;
+
+    // else allocate a new slot.
+    Index[MD] = submethods.size();
+    submethods.push_back(m);
+    if (MorallyVirtual) {
+      VCallOffset[MD] = Offset/8;
+      Index_t &idx = VCall[MD];
+      // Allocate the first one, after that, we reuse the previous one.
+      if (idx == 0) {
+        idx = VCalls.size()+1;
+        VCalls.push_back(0);
+      }
+    }
+  }
+
+  void AddMethods(const CXXRecordDecl *RD, bool MorallyVirtual,
+                  Index_t Offset) {
+    for (method_iter mi = RD->method_begin(), me = RD->method_end(); mi != me;
+         ++mi)
+      if (mi->isVirtual())
+        AddMethod(*mi, MorallyVirtual, Offset);
+  }
+
+  void NonVirtualBases(const CXXRecordDecl *RD, const ASTRecordLayout &Layout,
+                       const CXXRecordDecl *PrimaryBase,
+                       bool PrimaryBaseWasVirtual, bool MorallyVirtual,
+                       int64_t Offset) {
+    for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
+           e = RD->bases_end(); i != e; ++i) {
+      if (i->isVirtual())
+        continue;
+      const CXXRecordDecl *Base =
+        cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
+      if (Base != PrimaryBase || PrimaryBaseWasVirtual) {
+        uint64_t o = Offset + Layout.getBaseClassOffset(Base);
+        StartNewTable();
+        std::vector<std::pair<const CXXRecordDecl *,
+          int64_t> > S;
+        S.push_back(std::make_pair(RD, Offset));
+        GenerateVtableForBase(Base, MorallyVirtual, o, false, &S);
+      }
+    }
+  }
+
+  Index_t end(const CXXRecordDecl *RD, std::vector<llvm::Constant *> &offsets,
+              const ASTRecordLayout &Layout,
+              const CXXRecordDecl *PrimaryBase,
+              bool PrimaryBaseWasVirtual, bool MorallyVirtual,
+              int64_t Offset, bool ForVirtualBase) {
+    StartNewTable();
+    extra = 0;
+    // FIXME: Cleanup.
+    if (!ForVirtualBase) {
+      // then virtual base offsets...
+      for (std::vector<llvm::Constant *>::reverse_iterator i = offsets.rbegin(),
+             e = offsets.rend(); i != e; ++i)
+        methods.push_back(*i);
+    }
+
+    // The vcalls come first...
+    for (std::vector<Index_t>::reverse_iterator i=VCalls.rbegin(),
+           e=VCalls.rend();
+         i != e; ++i)
+      methods.push_back(wrap((0?600:0) + *i));
+    VCalls.clear();
+
+    if (ForVirtualBase) {
+      // then virtual base offsets...
+      for (std::vector<llvm::Constant *>::reverse_iterator i = offsets.rbegin(),
+             e = offsets.rend(); i != e; ++i)
+        methods.push_back(*i);
+    }
+
+    methods.push_back(wrap(-(Offset/8)));
+    methods.push_back(rtti);
+    Index_t AddressPoint = methods.size();
+
+    InstallThunks();
+    methods.insert(methods.end(), submethods.begin(), submethods.end());
+    submethods.clear();
+
+    // and then the non-virtual bases.
+    NonVirtualBases(RD, Layout, PrimaryBase, PrimaryBaseWasVirtual,
+                    MorallyVirtual, Offset);
+    return AddressPoint;
+  }
+
+  void Primaries(const CXXRecordDecl *RD, bool MorallyVirtual, int64_t Offset) {
+    if (!RD->isDynamicClass())
+      return;
+
+    const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
+    const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase();
+    const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual();
+
+    // vtables are composed from the chain of primaries.
+    if (PrimaryBase) {
+      if (PrimaryBaseWasVirtual)
+        IndirectPrimary.insert(PrimaryBase);
+      Primaries(PrimaryBase, PrimaryBaseWasVirtual|MorallyVirtual, Offset);
+    }
+
+    // And add the virtuals for the class to the primary vtable.
+    AddMethods(RD, MorallyVirtual, Offset);
+  }
+
+  int64_t GenerateVtableForBase(const CXXRecordDecl *RD,
+                                bool MorallyVirtual = false, int64_t Offset = 0,
+                                bool ForVirtualBase = false,
+                                std::vector<std::pair<const CXXRecordDecl *,
+                                int64_t> > *Path = 0) {
+    if (!RD->isDynamicClass())
+      return 0;
+
+    const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
+    const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase();
+    const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual();
+
+    std::vector<llvm::Constant *> offsets;
+    extra = 0;
+    GenerateVBaseOffsets(offsets, RD, Offset, !ForVirtualBase, 0);
+    if (ForVirtualBase)
+      extra = offsets.size();
+
+    // vtables are composed from the chain of primaries.
+    if (PrimaryBase) {
+      if (PrimaryBaseWasVirtual)
+        IndirectPrimary.insert(PrimaryBase);
+      Primaries(PrimaryBase, PrimaryBaseWasVirtual|MorallyVirtual, Offset);
+    }
+
+    // And add the virtuals for the class to the primary vtable.
+    AddMethods(RD, MorallyVirtual, Offset);
+
+    if (Path)
+      OverrideMethods(Path, MorallyVirtual);
+
+    return end(RD, offsets, Layout, PrimaryBase, PrimaryBaseWasVirtual,
+               MorallyVirtual, Offset, ForVirtualBase);
+  }
+
+  void GenerateVtableForVBases(const CXXRecordDecl *RD,
+                               int64_t Offset = 0,
+                               std::vector<std::pair<const CXXRecordDecl *,
+                               int64_t> > *Path = 0) {
+    bool alloc = false;
+    if (Path == 0) {
+      alloc = true;
+      Path = new std::vector<std::pair<const CXXRecordDecl *,
+        int64_t> >;
+    }
+    // FIXME: We also need to override using all paths to a virtual base,
+    // right now, we just process the first path
+    Path->push_back(std::make_pair(RD, Offset));
+    for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(),
+           e = RD->bases_end(); i != e; ++i) {
+      const CXXRecordDecl *Base =
+        cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl());
+      if (i->isVirtual() && !IndirectPrimary.count(Base)) {
+        // Mark it so we don't output it twice.
+        IndirectPrimary.insert(Base);
+        StartNewTable();
+        int64_t BaseOffset = BLayout.getVBaseClassOffset(Base);
+        GenerateVtableForBase(Base, true, BaseOffset, true, Path);
+      }
+      int64_t BaseOffset = Offset;
+      if (i->isVirtual())
+        BaseOffset = BLayout.getVBaseClassOffset(Base);
+      if (Base->getNumVBases())
+        GenerateVtableForVBases(Base, BaseOffset, Path);
+    }
+    Path->pop_back();
+    if (alloc)
+      delete Path;
+  }
+};
+
+
+VtableBuilder::Index_t VtableBuilder::VBlookup(CXXRecordDecl *D,
+                                               CXXRecordDecl *B) {
+  return CGM.getVtableInfo().getVirtualBaseOffsetIndex(D, B);
+}
+
+int64_t CGVtableInfo::getMethodVtableIndex(const CXXMethodDecl *MD) {
+  MD = MD->getCanonicalDecl();
+
+  MethodVtableIndicesTy::iterator I = MethodVtableIndices.find(MD);
+  if (I != MethodVtableIndices.end())
+    return I->second;
+  
+  const CXXRecordDecl *RD = MD->getParent();
+  
+  std::vector<llvm::Constant *> methods;
+  // FIXME: This seems expensive.  Can we do a partial job to get
+  // just this data.
+  VtableBuilder b(methods, RD, CGM);
+  b.GenerateVtableForBase(RD);
+  b.GenerateVtableForVBases(RD);
+  
+  MethodVtableIndices.insert(b.getIndex().begin(),
+                             b.getIndex().end());
+  
+  I = MethodVtableIndices.find(MD);
+  assert(I != MethodVtableIndices.end() && "Did not find index!");
+  return I->second;
+}
+
+int64_t CGVtableInfo::getVirtualBaseOffsetIndex(const CXXRecordDecl *RD, 
+                                                const CXXRecordDecl *VBase) {
+  ClassPairTy ClassPair(RD, VBase);
+  
+  VirtualBaseClassIndiciesTy::iterator I = 
+    VirtualBaseClassIndicies.find(ClassPair);
+  if (I != VirtualBaseClassIndicies.end())
+    return I->second;
+  
+  std::vector<llvm::Constant *> methods;
+  // FIXME: This seems expensive.  Can we do a partial job to get
+  // just this data.
+  VtableBuilder b(methods, RD, CGM);
+  b.GenerateVtableForBase(RD);
+  b.GenerateVtableForVBases(RD);
+  
+  for (llvm::DenseMap<const CXXRecordDecl *, uint64_t>::iterator I =
+       b.getVBIndex().begin(), E = b.getVBIndex().end(); I != E; ++I) {
+    // Insert all types.
+    ClassPairTy ClassPair(RD, I->first);
+    
+    VirtualBaseClassIndicies.insert(std::make_pair(ClassPair, I->second));
+  }
+  
+  I = VirtualBaseClassIndicies.find(ClassPair);
+  assert(I != VirtualBaseClassIndicies.end() && "Did not find index!");
+  
+  return I->second;
+}
+
+llvm::Value *CodeGenFunction::GenerateVtable(const CXXRecordDecl *RD) {
+  llvm::SmallString<256> OutName;
+  llvm::raw_svector_ostream Out(OutName);
+  mangleCXXVtable(CGM.getMangleContext(), RD, Out);
+
+  llvm::GlobalVariable::LinkageTypes linktype;
+  linktype = llvm::GlobalValue::WeakAnyLinkage;
+  std::vector<llvm::Constant *> methods;
+  llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0);
+  int64_t AddressPoint;
+
+  VtableBuilder b(methods, RD, CGM);
+
+  // First comes the vtables for all the non-virtual bases...
+  AddressPoint = b.GenerateVtableForBase(RD);
+
+  // then the vtables for all the virtual bases.
+  b.GenerateVtableForVBases(RD);
+
+  llvm::Constant *C;
+  llvm::ArrayType *type = llvm::ArrayType::get(Ptr8Ty, methods.size());
+  C = llvm::ConstantArray::get(type, methods);
+  llvm::Value *vtable = new llvm::GlobalVariable(CGM.getModule(), type, true,
+                                                 linktype, C, Out.str());
+  vtable = Builder.CreateBitCast(vtable, Ptr8Ty);
+  vtable = Builder.CreateGEP(vtable,
+                       llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext),
+                                              AddressPoint*LLVMPointerWidth/8));
+  return vtable;
+}