Move the vtable builder to CGVtable.cpp, general cleanup.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@83798 91177308-0d34-0410-b5e6-96231b3b80d8

8 files changed, 614 insertions, 554 deletions

diff --git a/clang.xcodeproj/project.pbxproj b/clang.xcodeproj/project.pbxproj
index 38e9c3d3c7..24e1ac360f 100644
--- a/clang.xcodeproj/project.pbxproj
+++ b/clang.xcodeproj/project.pbxproj
@@ -41,6 +41,7 @@
 		1A6FE7090FD6F85800E00CA9 /* CGCXXTemp.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A6FE7080FD6F85800E00CA9 /* CGCXXTemp.cpp */; };
 		1A701B640F7C8FE400FEC4D1 /* SemaAccess.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A701B630F7C8FE400FEC4D1 /* SemaAccess.cpp */; };
 		1A7342480C7B57D500122F56 /* CGObjC.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A7342470C7B57D500122F56 /* CGObjC.cpp */; };
+		1A81AA19108144F40094E50B /* CGVtable.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A81AA18108144F40094E50B /* CGVtable.cpp */; };
 		1A869A700BA2164C008DA07A /* LiteralSupport.h in CopyFiles */ = {isa = PBXBuildFile; fileRef = 1A869A6E0BA2164C008DA07A /* LiteralSupport.h */; };
 		1A869AA80BA21ABA008DA07A /* LiteralSupport.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1A869AA70BA21ABA008DA07A /* LiteralSupport.cpp */; };
 		1AA1D91810125DE30078DEBC /* RecordLayoutBuilder.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 1AA1D91610125DE30078DEBC /* RecordLayoutBuilder.cpp */; };
@@ -386,6 +387,8 @@
 		1A701B630F7C8FE400FEC4D1 /* SemaAccess.cpp */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = SemaAccess.cpp; path = lib/Sema/SemaAccess.cpp; sourceTree = "<group>"; tabWidth = 2; };
 		1A72BEAC0D641E9400B085E9 /* Attr.h */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.c.h; name = Attr.h; path = clang/AST/Attr.h; sourceTree = "<group>"; tabWidth = 2; };
 		1A7342470C7B57D500122F56 /* CGObjC.cpp */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = CGObjC.cpp; path = lib/CodeGen/CGObjC.cpp; sourceTree = "<group>"; tabWidth = 2; };
+		1A81AA18108144F40094E50B /* CGVtable.cpp */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = CGVtable.cpp; path = lib/CodeGen/CGVtable.cpp; sourceTree = "<group>"; tabWidth = 2; };
+		1A81AA5D108278A20094E50B /* CGVtable.h */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.c.h; name = CGVtable.h; path = lib/CodeGen/CGVtable.h; sourceTree = "<group>"; tabWidth = 2; };
 		1A869A6E0BA2164C008DA07A /* LiteralSupport.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = LiteralSupport.h; sourceTree = "<group>"; };
 		1A869AA70BA21ABA008DA07A /* LiteralSupport.cpp */ = {isa = PBXFileReference; fileEncoding = 30; lastKnownFileType = sourcecode.cpp.cpp; path = LiteralSupport.cpp; sourceTree = "<group>"; };
 		1AA1D91610125DE30078DEBC /* RecordLayoutBuilder.cpp */ = {isa = PBXFileReference; fileEncoding = 4; indentWidth = 2; lastKnownFileType = sourcecode.cpp.cpp; name = RecordLayoutBuilder.cpp; path = lib/AST/RecordLayoutBuilder.cpp; sourceTree = "<group>"; tabWidth = 2; };
@@ -1268,6 +1271,8 @@
 				1A6C01F6108128710072DEE4 /* CGRtti.cpp */,
 				DE4772F90C10EAE5002239E8 /* CGStmt.cpp */,
 				35475B230E7997680000BFE4 /* CGValue.h */,
+				1A81AA18108144F40094E50B /* CGVtable.cpp */,
+				1A81AA5D108278A20094E50B /* CGVtable.h */,
 				DE928B800C0A615B00231DA4 /* CodeGenFunction.h */,
 				DE928B820C0A616000231DA4 /* CodeGenFunction.cpp */,
 				DE928B7C0C0A615100231DA4 /* CodeGenModule.h */,
@@ -1895,6 +1900,7 @@
 				1A6B6E9A1069833600BB4A8F /* CGCXXExpr.cpp in Sources */,
 				1A535ED9107BC45E000C3AE7 /* CXXInheritance.cpp in Sources */,
 				1A6C01F7108128710072DEE4 /* CGRtti.cpp in Sources */,
+				1A81AA19108144F40094E50B /* CGVtable.cpp in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
diff --git a/lib/CodeGen/CGCXX.cpp b/lib/CodeGen/CGCXX.cpp
index 1dde3d22b8..ceb6e4927f 100644
--- a/lib/CodeGen/CGCXX.cpp
+++ b/lib/CodeGen/CGCXX.cpp
@@ -649,538 +649,6 @@ const char *CodeGenModule::getMangledCXXDtorName(const CXXDestructorDecl *D,
   return UniqueMangledName(Name.begin(), Name.end());
 }
 
-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<CallOffset, CallOffset> > 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) {
-    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() && !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);
-        VBIndex[Base] = -(offsets.size()*LLVMPointerWidth/8)
-          - 3*LLVMPointerWidth/8;
-        offsets.push_back(m);
-      }
-      GenerateVBaseOffsets(offsets, Base, Offset);
-    }
-  }
-
-  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;
-    // FIXME: temporal botch, is this data here, by the time we need it?
-
-    assert(false && "FIXME: Locate the containing virtual base first");
-    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
-          ReturnOffset = std::make_pair(42,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(ThisOffset, ReturnOffset);
-          else
-            Thunks[MD] = ThisOffset;
-          return true;
-        }
-#if 0
-        // FIXME: finish off
-        int64_t O = VCallOffset[OMD] - Offset/8;
-        if (O) {
-          Thunks[MD] = std::make_pair(O, 0);
-        }
-#endif
-        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;
-      Index_t v_t = i->second.first.second;
-      Index_t nv_r = i->second.second.first;
-      Index_t v_r = i->second.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);
-    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;
-  }
-};
-
-class VtableInfo {
-public:
-  typedef VtableBuilder::Index_t Index_t;
-private:
-  CodeGenModule &CGM;  // Per-module state.
-  /// Index_t - Vtable index type.
-  typedef llvm::DenseMap<const CXXMethodDecl *, Index_t> ElTy;
-  typedef llvm::DenseMap<const CXXRecordDecl *, ElTy *> MapTy;
-  // FIXME: Move to Context.
-  static MapTy IndexFor;
-
-  typedef llvm::DenseMap<const CXXRecordDecl *, Index_t> VBElTy;
-  typedef llvm::DenseMap<const CXXRecordDecl *, VBElTy *> VBMapTy;
-  // FIXME: Move to Context.
-  static VBMapTy VBIndexFor;
-public:
-  VtableInfo(CodeGenModule &cgm) : CGM(cgm) { }
-  void RegisterIndex(const CXXRecordDecl *RD, const ElTy &e) {
-    assert(IndexFor.find(RD) == IndexFor.end() && "Don't compute vtbl twice");
-    // We own a copy of this, it will go away shortly.
-    IndexFor[RD] = new ElTy (e);
-  }
-  void RegisterVBIndex(const CXXRecordDecl *RD, const VBElTy &e) {
-    assert(VBIndexFor.find(RD) == VBIndexFor.end() && "Don't compute vtbl twice");
-    // We own a copy of this, it will go away shortly.
-    VBIndexFor[RD] = new VBElTy (e);
-  }
-  Index_t lookup(const CXXMethodDecl *MD) {
-    const CXXRecordDecl *RD = MD->getParent();
-    MapTy::iterator I = IndexFor.find(RD);
-    if (I == IndexFor.end()) {
-      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);
-      RegisterIndex(RD, b.getIndex());
-      I = IndexFor.find(RD);
-    }
-    assert(I->second->find(MD)!=I->second->end() && "Can't find vtable index");
-    return (*I->second)[MD];
-  }
-  Index_t VBlookup(const CXXRecordDecl *RD, const CXXRecordDecl *BD) {
-    VBMapTy::iterator I = VBIndexFor.find(RD);
-    if (I == VBIndexFor.end()) {
-      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);
-      RegisterVBIndex(RD, b.getVBIndex());
-      I = VBIndexFor.find(RD);
-    }
-    assert(I->second->find(BD)!=I->second->end() && "Can't find vtable index");
-    return (*I->second)[BD];
-  }
-};
-
-// FIXME: move to Context
-static VtableInfo *vtableinfo;
-
-VtableBuilder::Index_t VtableBuilder::VBlookup(CXXRecordDecl *D,
-                                               CXXRecordDecl *B) {
-  if (vtableinfo == 0)
-    vtableinfo = new VtableInfo(CGM);
-
-  return vtableinfo->VBlookup(D, B);
-}
-
-
-// FIXME: Move to Context.
-VtableInfo::MapTy VtableInfo::IndexFor;
-
-// FIXME: Move to Context.
-VtableInfo::VBMapTy VtableInfo::VBIndexFor;
-
-llvm::Value *CodeGenFunction::GenerateVtable(const CXXRecordDecl *RD) {
-  llvm::SmallString<256> OutName;
-  llvm::raw_svector_ostream Out(OutName);
-  QualType ClassTy;
-  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;
-}
-
 llvm::Constant *CodeGenFunction::GenerateThunk(llvm::Function *Fn,
                                                const CXXMethodDecl *MD,
                                                bool Extern, int64_t nv,
@@ -1301,10 +769,6 @@ llvm::Value *
 CodeGenFunction::GetVirtualCXXBaseClassOffset(llvm::Value *This,
                                               const CXXRecordDecl *ClassDecl,
                                            const CXXRecordDecl *BaseClassDecl) {
-  // FIXME: move to Context
-  if (vtableinfo == 0)
-    vtableinfo = new VtableInfo(CGM);
-  
   const llvm::Type *Int8PtrTy = 
     llvm::Type::getInt8Ty(VMContext)->getPointerTo();
 
@@ -1312,10 +776,11 @@ CodeGenFunction::GetVirtualCXXBaseClassOffset(llvm::Value *This,
                                                  Int8PtrTy->getPointerTo());
   VTablePtr = Builder.CreateLoad(VTablePtr, "vtable");
 
+  int64_t VBaseOffsetIndex = 
+    CGM.getVtableInfo().getVirtualBaseOffsetIndex(ClassDecl, BaseClassDecl);
+  
   llvm::Value *VBaseOffsetPtr = 
-    Builder.CreateConstGEP1_64(VTablePtr, 
-                               vtableinfo->VBlookup(ClassDecl, BaseClassDecl),
-                               "vbase.offset.ptr");
+    Builder.CreateConstGEP1_64(VTablePtr, VBaseOffsetIndex, "vbase.offset.ptr");  
   const llvm::Type *PtrDiffTy = 
     ConvertType(getContext().getPointerDiffType());
   
@@ -1332,7 +797,7 @@ CodeGenFunction::BuildVirtualCall(const CXXMethodDecl *MD, llvm::Value *&This,
                                   const llvm::Type *Ty) {
   // FIXME: If we know the dynamic type, we don't have to do a virtual dispatch.
 
-  uint64_t Index = CGM.GetVtableIndex(MD);
+  int64_t Index = CGM.getVtableInfo().getMethodVtableIndex(MD);
   
   Ty = llvm::PointerType::get(Ty, 0);
   Ty = llvm::PointerType::get(Ty, 0);
@@ -1345,14 +810,6 @@ CodeGenFunction::BuildVirtualCall(const CXXMethodDecl *MD, llvm::Value *&This,
   return vfn;
 }
 
-uint64_t CodeGenModule::GetVtableIndex(const CXXMethodDecl *MD) {
-  // FIXME: move to CodeGenModule.
-  if (vtableinfo == 0)
-    vtableinfo = new VtableInfo(*this);
-  
-  return vtableinfo->lookup(MD);
-}
-
 /// EmitClassAggrMemberwiseCopy - This routine generates code to copy a class
 /// array of objects from SrcValue to DestValue. Copying can be either a bitwise
 /// copy or via a copy constructor call.
diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 82ec4fd0b7..b25636ed08 100644
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -298,7 +298,8 @@ void AggExprEmitter::VisitUnaryAddrOf(const UnaryOperator *E) {
   llvm::Value *FuncPtr;
   
   if (MD->isVirtual()) {
-    uint64_t Index = CGF.CGM.GetVtableIndex(MD->getCanonicalDecl());
+    int64_t Index = 
+      CGF.CGM.getVtableInfo().getMethodVtableIndex(MD);
     
     FuncPtr = llvm::ConstantInt::get(PtrDiffTy, Index + 1);
   } else {
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp
index 0fd765235c..fc24144f44 100644
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -413,7 +413,7 @@ public:
     
     // Get the function pointer (or index if this is a virtual function).
     if (MD->isVirtual()) {
-      uint64_t Index = CGM.GetVtableIndex(MD->getCanonicalDecl());
+      int64_t Index = CGM.getVtableInfo().getMethodVtableIndex(MD);
       
       Values[0] = llvm::ConstantInt::get(PtrDiffTy, Index + 1);
     } else {
diff --git a/lib/CodeGen/CGVtable.cpp b/lib/CodeGen/CGVtable.cpp
new file mode 100644
index 0000000000..cc40f2ff35
--- /dev/null
+++ b/lib/CodeGen/CGVtable.cpp
@@ -0,0 +1,534 @@
+//===--- 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<CallOffset, CallOffset> > 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) {
+    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() && !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);
+        VBIndex[Base] = -(offsets.size()*LLVMPointerWidth/8)
+          - 3*LLVMPointerWidth/8;
+        offsets.push_back(m);
+      }
+      GenerateVBaseOffsets(offsets, Base, Offset);
+    }
+  }
+
+  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;
+    // FIXME: temporal botch, is this data here, by the time we need it?
+
+    assert(false && "FIXME: Locate the containing virtual base first");
+    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
+          ReturnOffset = std::make_pair(42,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(ThisOffset, ReturnOffset);
+          else
+            Thunks[MD] = ThisOffset;
+          return true;
+        }
+#if 0
+        // FIXME: finish off
+        int64_t O = VCallOffset[OMD] - Offset/8;
+        if (O) {
+          Thunks[MD] = std::make_pair(O, 0);
+        }
+#endif
+        return true;
+      }
+    }
+
+    return false;
+  }
+
+  void InstallThunks() {
+    for (Thunks_t::iterator i = Thunks.begin(), e = Thunks.end();
+         i != e; ++i) {
+      const CXXMethodDecl *MD = i->first;
+