| //===--- 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; |
| // This is the offset to the nearest virtual base |
| llvm::DenseMap<const CXXMethodDecl *, Index_t> NonVirtualOffset; |
| llvm::DenseMap<const CXXRecordDecl *, Index_t> VBIndex; |
| |
| typedef llvm::DenseMap<const CXXMethodDecl *, int> Pures_t; |
| Pures_t Pures; |
| 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; |
| typedef std::vector<std::pair<const CXXRecordDecl *, int64_t> > Path_t; |
| llvm::Constant *cxa_pure; |
| 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); |
| |
| // Calculate pointer for ___cxa_pure_virtual. |
| const llvm::FunctionType *FTy; |
| std::vector<const llvm::Type*> ArgTys; |
| const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext); |
| FTy = llvm::FunctionType::get(ResultType, ArgTys, false); |
| cxa_pure = wrap(CGM.CreateRuntimeFunction(FTy, "__cxa_pure_virtual")); |
| } |
| |
| 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); |
| } |
| |
| #define D1(x) |
| //#define D1(X) do { if (getenv("DEBUG")) { X; } } while (0) |
| |
| void GenerateVBaseOffsets(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); |
| if (updateVBIndex) { |
| next_vbindex = (ssize_t)(-(VCalls.size()*LLVMPointerWidth/8) |
| - 3*LLVMPointerWidth/8); |
| VBIndex[Base] = next_vbindex; |
| } |
| int64_t BaseOffset = -(Offset/8) + BLayout.getVBaseClassOffset(Base)/8; |
| VCalls.push_back((0?700:0) + BaseOffset); |
| D1(printf(" vbase for %s at %d delta %d most derived %s\n", |
| Base->getNameAsCString(), |
| (int)-VCalls.size()-3, (int)BaseOffset, |
| Class->getNameAsCString())); |
| } |
| // 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(Base, Offset, updateVBIndex, next_vbindex); |
| } |
| } |
| |
| void StartNewTable() { |
| SeenVBase.clear(); |
| } |
| |
| Index_t VBlookup(CXXRecordDecl *D, CXXRecordDecl *B); |
| |
| Index_t getNVOffset_1(const CXXRecordDecl *D, const CXXRecordDecl *B, |
| Index_t Offset = 0) { |
| |
| if (B == D) |
| return Offset; |
| |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(D); |
| for (CXXRecordDecl::base_class_const_iterator i = D->bases_begin(), |
| e = D->bases_end(); i != e; ++i) { |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| int64_t BaseOffset = 0; |
| if (!i->isVirtual()) |
| BaseOffset = Offset + Layout.getBaseClassOffset(Base); |
| int64_t o = getNVOffset_1(Base, B, BaseOffset); |
| if (o >= 0) |
| return o; |
| } |
| |
| return -1; |
| } |
| |
| /// getNVOffset - Returns the non-virtual offset for the given (B) base of the |
| /// derived class D. |
| Index_t getNVOffset(QualType qB, QualType qD) { |
| qD = qD->getPointeeType(); |
| qB = qB->getPointeeType(); |
| CXXRecordDecl *D = cast<CXXRecordDecl>(qD->getAs<RecordType>()->getDecl()); |
| CXXRecordDecl *B = cast<CXXRecordDecl>(qB->getAs<RecordType>()->getDecl()); |
| int64_t o = getNVOffset_1(D, B); |
| if (o >= 0) |
| return o; |
| |
| assert(false && "FIXME: non-virtual base not found"); |
| return 0; |
| } |
| |
| /// 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->getPointeeType(); |
| qB = qB->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 OverrideOffset, |
| Index_t Offset, int64_t CurrentVBaseOffset) { |
| const bool isPure = MD->isPure(); |
| typedef CXXMethodDecl::method_iterator meth_iter; |
| // FIXME: Should OverrideOffset's be Offset? |
| |
| // 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 |
| if (CovariantThunks.count(OMD)) { |
| oret = CovariantThunks[OMD].second; |
| CovariantThunks.erase(OMD); |
| } |
| // FIXME: Double check oret |
| Index_t nv = getNVOffset(oret, ret)/8; |
| ReturnOffset = std::make_pair(nv, getVbaseOffset(oret, ret)); |
| } |
| Index[MD] = i; |
| submethods[i] = m; |
| if (isPure) |
| Pures[MD] = 1; |
| Pures.erase(OMD); |
| Thunks.erase(OMD); |
| if (MorallyVirtual || VCall.count(OMD)) { |
| Index_t &idx = VCall[OMD]; |
| if (idx == 0) { |
| NonVirtualOffset[MD] = -OverrideOffset/8 + CurrentVBaseOffset/8; |
| VCallOffset[MD] = OverrideOffset/8; |
| idx = VCalls.size()+1; |
| VCalls.push_back(0); |
| D1(printf(" vcall for %s at %d with delta %d most derived %s\n", |
| MD->getNameAsCString(), (int)-idx-3, (int)VCalls[idx-1], |
| Class->getNameAsCString())); |
| } else { |
| NonVirtualOffset[MD] = NonVirtualOffset[OMD]; |
| VCallOffset[MD] = VCallOffset[OMD]; |
| VCalls[idx-1] = -VCallOffset[OMD] + OverrideOffset/8; |
| D1(printf(" vcall patch for %s at %d with delta %d most derived %s\n", |
| MD->getNameAsCString(), (int)-idx-3, (int)VCalls[idx-1], |
| Class->getNameAsCString())); |
| } |
| VCall[MD] = idx; |
| int64_t O = NonVirtualOffset[MD]; |
| int v = -((idx+extra+2)*LLVMPointerWidth/8); |
| // Optimize out virtual adjustments of 0. |
| if (VCalls[idx-1] == 0) |
| v = 0; |
| CallOffset ThisOffset = std::make_pair(O, v); |
| // FIXME: Do we always have to build a covariant thunk to save oret, |
| // which is the containing virtual base class? |
| if (ReturnOffset.first || ReturnOffset.second) |
| CovariantThunks[MD] = std::make_pair(std::make_pair(ThisOffset, |
| ReturnOffset), |
| oret); |
| else if (!isPure && (ThisOffset.first || ThisOffset.second)) |
| Thunks[MD] = ThisOffset; |
| return true; |
| } |
| |
| // FIXME: finish off |
| int64_t O = VCallOffset[OMD] - OverrideOffset/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 if (!isPure) |
| 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; |
| assert(!MD->isPure() && "Trying to thunk a pure"); |
| 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; |
| if (MD->isPure()) |
| continue; |
| 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(); |
| for (Pures_t::iterator i = Pures.begin(), e = Pures.end(); |
| i != e; ++i) { |
| const CXXMethodDecl *MD = i->first; |
| Index_t idx = Index[MD]; |
| submethods[idx] = cxa_pure; |
| } |
| Pures.clear(); |
| } |
| |
| llvm::Constant *WrapAddrOf(const CXXMethodDecl *MD) { |
| if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) |
| return wrap(CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete)); |
| |
| const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); |
| const llvm::Type *Ty = |
| CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD), |
| FPT->isVariadic()); |
| |
| return wrap(CGM.GetAddrOfFunction(MD, Ty)); |
| } |
| |
| void OverrideMethods(Path_t *Path, bool MorallyVirtual, int64_t Offset, |
| int64_t CurrentVBaseOffset) { |
| for (Path_t::reverse_iterator i = Path->rbegin(), |
| e = Path->rend(); i != e; ++i) { |
| const CXXRecordDecl *RD = i->first; |
| int64_t OverrideOffset = 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 = WrapAddrOf(MD); |
| OverrideMethod(MD, m, MorallyVirtual, OverrideOffset, Offset, |
| CurrentVBaseOffset); |
| } |
| } |
| } |
| |
| void AddMethod(const CXXMethodDecl *MD, bool MorallyVirtual, Index_t Offset, |
| bool ForVirtualBase, int64_t CurrentVBaseOffset) { |
| llvm::Constant *m = WrapAddrOf(MD); |
| |
| // If we can find a previously allocated slot for this, reuse it. |
| if (OverrideMethod(MD, m, MorallyVirtual, Offset, Offset, |
| CurrentVBaseOffset)) |
| return; |
| |
| // else allocate a new slot. |
| Index[MD] = submethods.size(); |
| submethods.push_back(m); |
| D1(printf(" vfn for %s at %d\n", MD->getNameAsCString(), (int)Index[MD])); |
| if (MD->isPure()) |
| Pures[MD] = 1; |
| 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) { |
| NonVirtualOffset[MD] = CurrentVBaseOffset/8 - Offset/8; |
| idx = VCalls.size()+1; |
| VCalls.push_back(0); |
| D1(printf(" vcall for %s at %d with delta %d\n", |
| MD->getNameAsCString(), (int)-VCalls.size()-3, 0)); |
| } |
| } |
| } |
| |
| void AddMethods(const CXXRecordDecl *RD, bool MorallyVirtual, |
| Index_t Offset, bool RDisVirtualBase, |
| int64_t CurrentVBaseOffset) { |
| for (method_iter mi = RD->method_begin(), me = RD->method_end(); mi != me; |
| ++mi) |
| if (mi->isVirtual()) |
| AddMethod(*mi, MorallyVirtual, Offset, RDisVirtualBase, |
| CurrentVBaseOffset); |
| } |
| |
| void NonVirtualBases(const CXXRecordDecl *RD, const ASTRecordLayout &Layout, |
| const CXXRecordDecl *PrimaryBase, |
| bool PrimaryBaseWasVirtual, bool MorallyVirtual, |
| int64_t Offset, int64_t CurrentVBaseOffset, |
| Path_t *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) { |
| 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(); |
| GenerateVtableForBase(Base, MorallyVirtual, o, false, |
| CurrentVBaseOffset, Path); |
| } |
| } |
| Path->pop_back(); |
| } |
| |
| // #define D(X) do { X; } while (0) |
| #define D(X) |
| |
| void insertVCalls(int InsertionPoint) { |
| llvm::Constant *e = 0; |
| D1(printf("============= combining vbase/vcall\n")); |
| D(VCalls.insert(VCalls.begin(), 673)); |
| D(VCalls.push_back(672)); |
| methods.insert(methods.begin() + InsertionPoint, VCalls.size(), e); |
| // The vcalls come first... |
| for (std::vector<Index_t>::reverse_iterator i = VCalls.rbegin(), |
| e = VCalls.rend(); |
| i != e; ++i) |
| methods[InsertionPoint++] = wrap((0?600:0) + *i); |
| VCalls.clear(); |
| VCall.clear(); |
| } |
| |
| Index_t end(const CXXRecordDecl *RD, const ASTRecordLayout &Layout, |
| const CXXRecordDecl *PrimaryBase, bool PrimaryBaseWasVirtual, |
| bool MorallyVirtual, int64_t Offset, bool ForVirtualBase, |
| int64_t CurrentVBaseOffset, |
| Path_t *Path) { |
| bool alloc = false; |
| if (Path == 0) { |
| alloc = true; |
| Path = new Path_t; |
| } |
| |
| StartNewTable(); |
| extra = 0; |
| bool DeferVCalls = MorallyVirtual || ForVirtualBase; |
| int VCallInsertionPoint = methods.size(); |
| if (!DeferVCalls) { |
| insertVCalls(VCallInsertionPoint); |
| } else |
| // FIXME: just for extra, or for all uses of VCalls.size post this? |
| extra = -VCalls.size(); |
| |
| methods.push_back(wrap(-(Offset/8))); |
| methods.push_back(rtti); |
| Index_t AddressPoint = methods.size(); |
| |
| InstallThunks(); |
| D1(printf("============= combining methods\n")); |
| methods.insert(methods.end(), submethods.begin(), submethods.end()); |
| submethods.clear(); |
| |
| // and then the non-virtual bases. |
| NonVirtualBases(RD, Layout, PrimaryBase, PrimaryBaseWasVirtual, |
| MorallyVirtual, Offset, CurrentVBaseOffset, Path); |
| |
| if (ForVirtualBase) { |
| insertVCalls(VCallInsertionPoint); |
| AddressPoint += VCalls.size(); |
| } |
| |
| if (alloc) { |
| delete Path; |
| } |
| return AddressPoint; |
| } |
| |
| void Primaries(const CXXRecordDecl *RD, bool MorallyVirtual, int64_t Offset, |
| bool updateVBIndex, Index_t current_vbindex, |
| bool RDisVirtualBase, int64_t CurrentVBaseOffset) { |
| 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) { |
| D1(printf(" doing primaries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| |
| int BaseCurrentVBaseOffset = CurrentVBaseOffset; |
| if (PrimaryBaseWasVirtual) |
| BaseCurrentVBaseOffset = BLayout.getVBaseClassOffset(PrimaryBase); |
| |
| if (!PrimaryBaseWasVirtual) |
| Primaries(PrimaryBase, PrimaryBaseWasVirtual|MorallyVirtual, Offset, |
| updateVBIndex, current_vbindex, PrimaryBaseWasVirtual, |
| BaseCurrentVBaseOffset); |
| } |
| |
| D1(printf(" doing vcall entries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| |
| // And add the virtuals for the class to the primary vtable. |
| AddMethods(RD, MorallyVirtual, Offset, RDisVirtualBase, CurrentVBaseOffset); |
| } |
| |
| void VBPrimaries(const CXXRecordDecl *RD, bool MorallyVirtual, int64_t Offset, |
| bool updateVBIndex, Index_t current_vbindex, |
| bool RDisVirtualBase, int64_t CurrentVBaseOffset, |
| bool bottom=false) { |
| 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) { |
| int BaseCurrentVBaseOffset = CurrentVBaseOffset; |
| if (PrimaryBaseWasVirtual) { |
| IndirectPrimary.insert(PrimaryBase); |
| BaseCurrentVBaseOffset = BLayout.getVBaseClassOffset(PrimaryBase); |
| } |
| |
| D1(printf(" doing primaries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| |
| VBPrimaries(PrimaryBase, PrimaryBaseWasVirtual|MorallyVirtual, Offset, |
| updateVBIndex, current_vbindex, PrimaryBaseWasVirtual, |
| BaseCurrentVBaseOffset); |
| } |
| |
| D1(printf(" doing vbase entries for %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| GenerateVBaseOffsets(RD, Offset, updateVBIndex, current_vbindex); |
| |
| if (RDisVirtualBase || bottom) { |
| Primaries(RD, MorallyVirtual, Offset, updateVBIndex, current_vbindex, |
| RDisVirtualBase, CurrentVBaseOffset); |
| } |
| } |
| |
| int64_t GenerateVtableForBase(const CXXRecordDecl *RD, |
| bool MorallyVirtual = false, int64_t Offset = 0, |
| bool ForVirtualBase = false, |
| int CurrentVBaseOffset = 0, |
| Path_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(); |
| |
| extra = 0; |
| D1(printf("building entries for base %s most derived %s\n", |
| RD->getNameAsCString(), Class->getNameAsCString())); |
| |
| if (ForVirtualBase) |
| extra = VCalls.size(); |
| |
| VBPrimaries(RD, MorallyVirtual, Offset, !ForVirtualBase, 0, ForVirtualBase, |
| CurrentVBaseOffset, true); |
| |
| if (Path) |
| OverrideMethods(Path, MorallyVirtual, Offset, CurrentVBaseOffset); |
| |
| return end(RD, Layout, PrimaryBase, PrimaryBaseWasVirtual, MorallyVirtual, |
| Offset, ForVirtualBase, CurrentVBaseOffset, Path); |
| } |
| |
| void GenerateVtableForVBases(const CXXRecordDecl *RD, |
| int64_t Offset = 0, |
| Path_t *Path = 0) { |
| bool alloc = false; |
| if (Path == 0) { |
| alloc = true; |
| Path = new Path_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(); |
| VCall.clear(); |
| int64_t BaseOffset = BLayout.getVBaseClassOffset(Base); |
| int64_t CurrentVBaseOffset = BaseOffset; |
| D1(printf("vtable %s virtual base %s\n", |
| Class->getNameAsCString(), Base->getNameAsCString())); |
| GenerateVtableForBase(Base, true, BaseOffset, true, CurrentVBaseOffset, |
| 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); |
| D1(printf("vtable %s\n", RD->getNameAsCString())); |
| 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); |
| D1(printf("vtable %s\n", RD->getNameAsCString())); |
| 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::Constant *CodeGenModule::GenerateVtable(const CXXRecordDecl *RD, |
| const CXXRecordDecl *LayoutClass, |
| uint64_t Offset) { |
| llvm::SmallString<256> OutName; |
| llvm::raw_svector_ostream Out(OutName); |
| if (LayoutClass) |
| mangleCXXCtorVtable(getMangleContext(), LayoutClass, Offset, RD, Out); |
| else |
| mangleCXXVtable(getMangleContext(), RD, Out); |
| |
| llvm::GlobalVariable::LinkageTypes linktype; |
| linktype = llvm::GlobalValue::LinkOnceODRLinkage; |
| std::vector<llvm::Constant *> methods; |
| llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0); |
| int64_t AddressPoint; |
| |
| VtableBuilder b(methods, RD, *this); |
| |
| D1(printf("vtable %s\n", RD->getNameAsCString())); |
| // 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::Constant *vtable = new llvm::GlobalVariable(getModule(), type, |
| true, linktype, C, |
| Out.str()); |
| vtable = llvm::ConstantExpr::getBitCast(vtable, Ptr8Ty); |
| llvm::Constant *AddressPointC; |
| uint32_t LLVMPointerWidth = getContext().Target.getPointerWidth(0); |
| AddressPointC = llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext), |
| AddressPoint*LLVMPointerWidth/8); |
| vtable = llvm::ConstantExpr::getGetElementPtr(vtable, &AddressPointC, 1); |
| |
| return vtable; |
| } |
| |
| class VTTBuilder { |
| /// Inits - The list of values built for the VTT. |
| std::vector<llvm::Constant *> &Inits; |
| /// Class - The most derived class that this vtable is being built for. |
| const CXXRecordDecl *Class; |
| CodeGenModule &CGM; // Per-module state. |
| llvm::SmallSet<const CXXRecordDecl *, 32> SeenVBase; |
| /// BLayout - Layout for the most derived class that this vtable is being |
| /// built for. |
| const ASTRecordLayout &BLayout; |
| |
| /// Secondary - Add the secondary vtable pointers to Inits. |
| void Secondary(const CXXRecordDecl *RD, uint64_t Offset=0, |
| bool MorallyVirtual=false) { |
| if (RD->getNumVBases() == 0 && ! MorallyVirtual) |
| return; |
| |
| 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()); |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); |
| const bool PrimaryBaseWasVirtual = Layout.getPrimaryBaseWasVirtual(); |
| bool NonVirtualPrimaryBase; |
| NonVirtualPrimaryBase = !PrimaryBaseWasVirtual && Base == PrimaryBase; |
| bool BaseMorallyVirtual = MorallyVirtual | i->isVirtual(); |
| uint64_t BaseOffset; |
| if (!i->isVirtual()) { |
| const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD); |
| BaseOffset = Offset + Layout.getBaseClassOffset(Base); |
| } else |
| BaseOffset = BLayout.getVBaseClassOffset(Base); |
| if ((Base->getNumVBases() || BaseMorallyVirtual) |
| && !NonVirtualPrimaryBase) { |
| // FIXME: Slightly too many of these for __ZTT8test8_B2 |
| llvm::Constant *vtbl; |
| vtbl = CGM.getVtableInfo().getCtorVtable(Base, Class, BaseOffset/8); |
| Inits.push_back(vtbl); |
| } |
| Secondary(Base, BaseOffset, BaseMorallyVirtual); |
| } |
| } |
| |
| /// BuiltVTT - Add the VTT to Inits. |
| void BuildVTT(const CXXRecordDecl *RD, uint64_t Offset, |
| bool MorallyVirtual=false) { |
| if (RD->getNumVBases() == 0 && !MorallyVirtual) |
| return; |
| |
| // First comes the primary virtual table pointer... |
| Inits.push_back(CGM.getVtableInfo().getCtorVtable(RD, Class, Offset)); |
| |
| // then the secondary VTTs.... |
| SecondaryVTTs(RD, MorallyVirtual); |
| |
| // and last the secondary vtable pointers. |
| Secondary(RD, MorallyVirtual, Offset); |
| } |
| |
| /// SecondaryVTTs - Add the secondary VTTs to Inits. The secondary VTTs are |
| /// built from each direct non-virtual proper base that requires a VTT in |
| /// declaration order. |
| void SecondaryVTTs(const CXXRecordDecl *RD, bool MorallyVirtual=false) { |
| 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()) |
| continue; |
| BuildVTT(Base, MorallyVirtual); |
| } |
| } |
| |
| /// VirtualVTTs - Add the VTT for each proper virtual base in inheritance |
| /// graph preorder. |
| void VirtualVTTs(const CXXRecordDecl *RD) { |
| 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); |
| BuildVTT(Base, true); |
| } |
| VirtualVTTs(Base); |
| } |
| } |
| public: |
| VTTBuilder(std::vector<llvm::Constant *> &inits, const CXXRecordDecl *c, |
| CodeGenModule &cgm) |
| : Inits(inits), Class(c), CGM(cgm), |
| BLayout(cgm.getContext().getASTRecordLayout(c)) { |
| |
| // First comes the primary virtual table pointer for the complete class... |
| Inits.push_back(CGM.getVtableInfo().getVtable(Class)); |
| |
| // then the secondary VTTs... |
| SecondaryVTTs(Class); |
| |
| // then the secondary vtable pointers... |
| Secondary(Class); |
| |
| // and last, the virtual VTTs. |
| VirtualVTTs(Class); |
| } |
| }; |
| |
| llvm::Constant *CodeGenModule::GenerateVTT(const CXXRecordDecl *RD) { |
| // Only classes that have virtual bases need a VTT. |
| if (RD->getNumVBases() == 0) |
| return 0; |
| |
| llvm::SmallString<256> OutName; |
| llvm::raw_svector_ostream Out(OutName); |
| mangleCXXVTT(getMangleContext(), RD, Out); |
| |
| llvm::GlobalVariable::LinkageTypes linktype; |
| linktype = llvm::GlobalValue::LinkOnceODRLinkage; |
| std::vector<llvm::Constant *> inits; |
| llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0); |
| |
| D1(printf("vtt %s\n", RD->getNameAsCString())); |
| |
| VTTBuilder b(inits, RD, *this); |
| |
| llvm::Constant *C; |
| llvm::ArrayType *type = llvm::ArrayType::get(Ptr8Ty, inits.size()); |
| C = llvm::ConstantArray::get(type, inits); |
| llvm::Constant *vtt = new llvm::GlobalVariable(getModule(), type, true, |
| linktype, C, Out.str()); |
| vtt = llvm::ConstantExpr::getBitCast(vtt, Ptr8Ty); |
| return vtt; |
| } |
| |
| llvm::Constant *CGVtableInfo::getVtable(const CXXRecordDecl *RD) { |
| llvm::Constant *&vtbl = Vtables[RD]; |
| if (vtbl) |
| return vtbl; |
| vtbl = CGM.GenerateVtable(RD); |
| CGM.GenerateVTT(RD); |
| return vtbl; |
| } |
| |
| llvm::Constant *CGVtableInfo::getCtorVtable(const CXXRecordDecl *RD, |
| const CXXRecordDecl *Class, |
| uint64_t Offset) { |
| return CGM.GenerateVtable(RD, Class, Offset); |
| } |