clang  10.0.0svn
MicrosoftCXXABI.cpp
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1 //===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This provides C++ code generation targeting the Microsoft Visual C++ ABI.
10 // The class in this file generates structures that follow the Microsoft
11 // Visual C++ ABI, which is actually not very well documented at all outside
12 // of Microsoft.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "CGCXXABI.h"
17 #include "CGCleanup.h"
18 #include "CGVTables.h"
19 #include "CodeGenModule.h"
20 #include "CodeGenTypes.h"
21 #include "TargetInfo.h"
23 #include "clang/AST/Decl.h"
24 #include "clang/AST/DeclCXX.h"
25 #include "clang/AST/StmtCXX.h"
27 #include "llvm/ADT/StringExtras.h"
28 #include "llvm/ADT/StringSet.h"
29 #include "llvm/IR/Intrinsics.h"
30 
31 using namespace clang;
32 using namespace CodeGen;
33 
34 namespace {
35 
36 /// Holds all the vbtable globals for a given class.
37 struct VBTableGlobals {
38  const VPtrInfoVector *VBTables;
40 };
41 
42 class MicrosoftCXXABI : public CGCXXABI {
43 public:
44  MicrosoftCXXABI(CodeGenModule &CGM)
45  : CGCXXABI(CGM), BaseClassDescriptorType(nullptr),
46  ClassHierarchyDescriptorType(nullptr),
47  CompleteObjectLocatorType(nullptr), CatchableTypeType(nullptr),
48  ThrowInfoType(nullptr) {}
49 
50  bool HasThisReturn(GlobalDecl GD) const override;
51  bool hasMostDerivedReturn(GlobalDecl GD) const override;
52 
53  bool classifyReturnType(CGFunctionInfo &FI) const override;
54 
55  RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override;
56 
57  bool isSRetParameterAfterThis() const override { return true; }
58 
59  bool isThisCompleteObject(GlobalDecl GD) const override {
60  // The Microsoft ABI doesn't use separate complete-object vs.
61  // base-object variants of constructors, but it does of destructors.
62  if (isa<CXXDestructorDecl>(GD.getDecl())) {
63  switch (GD.getDtorType()) {
64  case Dtor_Complete:
65  case Dtor_Deleting:
66  return true;
67 
68  case Dtor_Base:
69  return false;
70 
71  case Dtor_Comdat: llvm_unreachable("emitting dtor comdat as function?");
72  }
73  llvm_unreachable("bad dtor kind");
74  }
75 
76  // No other kinds.
77  return false;
78  }
79 
80  size_t getSrcArgforCopyCtor(const CXXConstructorDecl *CD,
81  FunctionArgList &Args) const override {
82  assert(Args.size() >= 2 &&
83  "expected the arglist to have at least two args!");
84  // The 'most_derived' parameter goes second if the ctor is variadic and
85  // has v-bases.
86  if (CD->getParent()->getNumVBases() > 0 &&
87  CD->getType()->castAs<FunctionProtoType>()->isVariadic())
88  return 2;
89  return 1;
90  }
91 
92  std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD) override {
93  std::vector<CharUnits> VBPtrOffsets;
94  const ASTContext &Context = getContext();
95  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
96 
97  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
98  for (const std::unique_ptr<VPtrInfo> &VBT : *VBGlobals.VBTables) {
99  const ASTRecordLayout &SubobjectLayout =
100  Context.getASTRecordLayout(VBT->IntroducingObject);
101  CharUnits Offs = VBT->NonVirtualOffset;
102  Offs += SubobjectLayout.getVBPtrOffset();
103  if (VBT->getVBaseWithVPtr())
104  Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
105  VBPtrOffsets.push_back(Offs);
106  }
107  llvm::array_pod_sort(VBPtrOffsets.begin(), VBPtrOffsets.end());
108  return VBPtrOffsets;
109  }
110 
111  StringRef GetPureVirtualCallName() override { return "_purecall"; }
112  StringRef GetDeletedVirtualCallName() override { return "_purecall"; }
113 
114  void emitVirtualObjectDelete(CodeGenFunction &CGF, const CXXDeleteExpr *DE,
115  Address Ptr, QualType ElementType,
116  const CXXDestructorDecl *Dtor) override;
117 
118  void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) override;
119  void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) override;
120 
121  void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) override;
122 
123  llvm::GlobalVariable *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
124  const VPtrInfo &Info);
125 
126  llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
128  getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) override;
129 
130  /// MSVC needs an extra flag to indicate a catchall.
131  CatchTypeInfo getCatchAllTypeInfo() override {
132  return CatchTypeInfo{nullptr, 0x40};
133  }
134 
135  bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
136  void EmitBadTypeidCall(CodeGenFunction &CGF) override;
137  llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
138  Address ThisPtr,
139  llvm::Type *StdTypeInfoPtrTy) override;
140 
141  bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
142  QualType SrcRecordTy) override;
143 
144  llvm::Value *EmitDynamicCastCall(CodeGenFunction &CGF, Address Value,
145  QualType SrcRecordTy, QualType DestTy,
146  QualType DestRecordTy,
147  llvm::BasicBlock *CastEnd) override;
148 
149  llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
150  QualType SrcRecordTy,
151  QualType DestTy) override;
152 
153  bool EmitBadCastCall(CodeGenFunction &CGF) override;
154  bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override {
155  return false;
156  }
157 
158  llvm::Value *
159  GetVirtualBaseClassOffset(CodeGenFunction &CGF, Address This,
160  const CXXRecordDecl *ClassDecl,
161  const CXXRecordDecl *BaseClassDecl) override;
162 
163  llvm::BasicBlock *
164  EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
165  const CXXRecordDecl *RD) override;
166 
167  llvm::BasicBlock *
168  EmitDtorCompleteObjectHandler(CodeGenFunction &CGF);
169 
170  void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
171  const CXXRecordDecl *RD) override;
172 
173  void EmitCXXConstructors(const CXXConstructorDecl *D) override;
174 
175  // Background on MSVC destructors
176  // ==============================
177  //
178  // Both Itanium and MSVC ABIs have destructor variants. The variant names
179  // roughly correspond in the following way:
180  // Itanium Microsoft
181  // Base -> no name, just ~Class
182  // Complete -> vbase destructor
183  // Deleting -> scalar deleting destructor
184  // vector deleting destructor
185  //
186  // The base and complete destructors are the same as in Itanium, although the
187  // complete destructor does not accept a VTT parameter when there are virtual
188  // bases. A separate mechanism involving vtordisps is used to ensure that
189  // virtual methods of destroyed subobjects are not called.
190  //
191  // The deleting destructors accept an i32 bitfield as a second parameter. Bit
192  // 1 indicates if the memory should be deleted. Bit 2 indicates if the this
193  // pointer points to an array. The scalar deleting destructor assumes that
194  // bit 2 is zero, and therefore does not contain a loop.
195  //
196  // For virtual destructors, only one entry is reserved in the vftable, and it
197  // always points to the vector deleting destructor. The vector deleting
198  // destructor is the most general, so it can be used to destroy objects in
199  // place, delete single heap objects, or delete arrays.
200  //
201  // A TU defining a non-inline destructor is only guaranteed to emit a base
202  // destructor, and all of the other variants are emitted on an as-needed basis
203  // in COMDATs. Because a non-base destructor can be emitted in a TU that
204  // lacks a definition for the destructor, non-base destructors must always
205  // delegate to or alias the base destructor.
206 
207  AddedStructorArgs
208  buildStructorSignature(GlobalDecl GD,
209  SmallVectorImpl<CanQualType> &ArgTys) override;
210 
211  /// Non-base dtors should be emitted as delegating thunks in this ABI.
212  bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
213  CXXDtorType DT) const override {
214  return DT != Dtor_Base;
215  }
216 
217  void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
218  const CXXDestructorDecl *Dtor,
219  CXXDtorType DT) const override;
220 
221  llvm::GlobalValue::LinkageTypes
222  getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
223  CXXDtorType DT) const override;
224 
225  void EmitCXXDestructors(const CXXDestructorDecl *D) override;
226 
227  const CXXRecordDecl *
228  getThisArgumentTypeForMethod(const CXXMethodDecl *MD) override {
229  if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
231  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD);
232  // The vbases might be ordered differently in the final overrider object
233  // and the complete object, so the "this" argument may sometimes point to
234  // memory that has no particular type (e.g. past the complete object).
235  // In this case, we just use a generic pointer type.
236  // FIXME: might want to have a more precise type in the non-virtual
237  // multiple inheritance case.
238  if (ML.VBase || !ML.VFPtrOffset.isZero())
239  return nullptr;
240  }
241  return MD->getParent();
242  }
243 
244  Address
245  adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
246  Address This,
247  bool VirtualCall) override;
248 
249  void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
250  FunctionArgList &Params) override;
251 
252  void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override;
253 
254  AddedStructorArgs
255  addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
256  CXXCtorType Type, bool ForVirtualBase,
257  bool Delegating, CallArgList &Args) override;
258 
259  void EmitDestructorCall(CodeGenFunction &CGF, const CXXDestructorDecl *DD,
260  CXXDtorType Type, bool ForVirtualBase,
261  bool Delegating, Address This,
262  QualType ThisTy) override;
263 
264  void emitVTableTypeMetadata(const VPtrInfo &Info, const CXXRecordDecl *RD,
265  llvm::GlobalVariable *VTable);
266 
267  void emitVTableDefinitions(CodeGenVTables &CGVT,
268  const CXXRecordDecl *RD) override;
269 
270  bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
271  CodeGenFunction::VPtr Vptr) override;
272 
273  /// Don't initialize vptrs if dynamic class
274  /// is marked with with the 'novtable' attribute.
275  bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
276  return !VTableClass->hasAttr<MSNoVTableAttr>();
277  }
278 
279  llvm::Constant *
280  getVTableAddressPoint(BaseSubobject Base,
281  const CXXRecordDecl *VTableClass) override;
282 
283  llvm::Value *getVTableAddressPointInStructor(
284  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
285  BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
286 
287  llvm::Constant *
288  getVTableAddressPointForConstExpr(BaseSubobject Base,
289  const CXXRecordDecl *VTableClass) override;
290 
291  llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
292  CharUnits VPtrOffset) override;
293 
294  CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
295  Address This, llvm::Type *Ty,
296  SourceLocation Loc) override;
297 
298  llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
299  const CXXDestructorDecl *Dtor,
300  CXXDtorType DtorType, Address This,
301  DeleteOrMemberCallExpr E) override;
302 
303  void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
304  CallArgList &CallArgs) override {
305  assert(GD.getDtorType() == Dtor_Deleting &&
306  "Only deleting destructor thunks are available in this ABI");
307  CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
308  getContext().IntTy);
309  }
310 
311  void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
312 
313  llvm::GlobalVariable *
314  getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
315  llvm::GlobalVariable::LinkageTypes Linkage);
316 
317  llvm::GlobalVariable *
318  getAddrOfVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
319  const CXXRecordDecl *DstRD) {
320  SmallString<256> OutName;
321  llvm::raw_svector_ostream Out(OutName);
322  getMangleContext().mangleCXXVirtualDisplacementMap(SrcRD, DstRD, Out);
323  StringRef MangledName = OutName.str();
324 
325  if (auto *VDispMap = CGM.getModule().getNamedGlobal(MangledName))
326  return VDispMap;
327 
328  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
329  unsigned NumEntries = 1 + SrcRD->getNumVBases();
330  SmallVector<llvm::Constant *, 4> Map(NumEntries,
331  llvm::UndefValue::get(CGM.IntTy));
332  Map[0] = llvm::ConstantInt::get(CGM.IntTy, 0);
333  bool AnyDifferent = false;
334  for (const auto &I : SrcRD->vbases()) {
335  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
336  if (!DstRD->isVirtuallyDerivedFrom(VBase))
337  continue;
338 
339  unsigned SrcVBIndex = VTContext.getVBTableIndex(SrcRD, VBase);
340  unsigned DstVBIndex = VTContext.getVBTableIndex(DstRD, VBase);
341  Map[SrcVBIndex] = llvm::ConstantInt::get(CGM.IntTy, DstVBIndex * 4);
342  AnyDifferent |= SrcVBIndex != DstVBIndex;
343  }
344  // This map would be useless, don't use it.
345  if (!AnyDifferent)
346  return nullptr;
347 
348  llvm::ArrayType *VDispMapTy = llvm::ArrayType::get(CGM.IntTy, Map.size());
349  llvm::Constant *Init = llvm::ConstantArray::get(VDispMapTy, Map);
350  llvm::GlobalValue::LinkageTypes Linkage =
351  SrcRD->isExternallyVisible() && DstRD->isExternallyVisible()
352  ? llvm::GlobalValue::LinkOnceODRLinkage
354  auto *VDispMap = new llvm::GlobalVariable(
355  CGM.getModule(), VDispMapTy, /*isConstant=*/true, Linkage,
356  /*Initializer=*/Init, MangledName);
357  return VDispMap;
358  }
359 
360  void emitVBTableDefinition(const VPtrInfo &VBT, const CXXRecordDecl *RD,
361  llvm::GlobalVariable *GV) const;
362 
363  void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
364  GlobalDecl GD, bool ReturnAdjustment) override {
365  GVALinkage Linkage =
366  getContext().GetGVALinkageForFunction(cast<FunctionDecl>(GD.getDecl()));
367 
368  if (Linkage == GVA_Internal)
369  Thunk->setLinkage(llvm::GlobalValue::InternalLinkage);
370  else if (ReturnAdjustment)
371  Thunk->setLinkage(llvm::GlobalValue::WeakODRLinkage);
372  else
373  Thunk->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
374  }
375 
376  bool exportThunk() override { return false; }
377 
378  llvm::Value *performThisAdjustment(CodeGenFunction &CGF, Address This,
379  const ThisAdjustment &TA) override;
380 
381  llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
382  const ReturnAdjustment &RA) override;
383 
384  void EmitThreadLocalInitFuncs(
385  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
386  ArrayRef<llvm::Function *> CXXThreadLocalInits,
387  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) override;
388 
389  bool usesThreadWrapperFunction(const VarDecl *VD) const override {
390  return false;
391  }
392  LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF, const VarDecl *VD,
393  QualType LValType) override;
394 
395  void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
396  llvm::GlobalVariable *DeclPtr,
397  bool PerformInit) override;
398  void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
399  llvm::FunctionCallee Dtor,
400  llvm::Constant *Addr) override;
401 
402  // ==== Notes on array cookies =========
403  //
404  // MSVC seems to only use cookies when the class has a destructor; a
405  // two-argument usual array deallocation function isn't sufficient.
406  //
407  // For example, this code prints "100" and "1":
408  // struct A {
409  // char x;
410  // void *operator new[](size_t sz) {
411  // printf("%u\n", sz);
412  // return malloc(sz);
413  // }
414  // void operator delete[](void *p, size_t sz) {
415  // printf("%u\n", sz);
416  // free(p);
417  // }
418  // };
419  // int main() {
420  // A *p = new A[100];
421  // delete[] p;
422  // }
423  // Whereas it prints "104" and "104" if you give A a destructor.
424 
425  bool requiresArrayCookie(const CXXDeleteExpr *expr,
426  QualType elementType) override;
427  bool requiresArrayCookie(const CXXNewExpr *expr) override;
428  CharUnits getArrayCookieSizeImpl(QualType type) override;
429  Address InitializeArrayCookie(CodeGenFunction &CGF,
430  Address NewPtr,
431  llvm::Value *NumElements,
432  const CXXNewExpr *expr,
433  QualType ElementType) override;
434  llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
435  Address allocPtr,
436  CharUnits cookieSize) override;
437 
438  friend struct MSRTTIBuilder;
439 
440  bool isImageRelative() const {
441  return CGM.getTarget().getPointerWidth(/*AddrSpace=*/0) == 64;
442  }
443 
444  // 5 routines for constructing the llvm types for MS RTTI structs.
445  llvm::StructType *getTypeDescriptorType(StringRef TypeInfoString) {
446  llvm::SmallString<32> TDTypeName("rtti.TypeDescriptor");
447  TDTypeName += llvm::utostr(TypeInfoString.size());
448  llvm::StructType *&TypeDescriptorType =
449  TypeDescriptorTypeMap[TypeInfoString.size()];
450  if (TypeDescriptorType)
451  return TypeDescriptorType;
452  llvm::Type *FieldTypes[] = {
453  CGM.Int8PtrPtrTy,
454  CGM.Int8PtrTy,
455  llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
456  TypeDescriptorType =
457  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
458  return TypeDescriptorType;
459  }
460 
461  llvm::Type *getImageRelativeType(llvm::Type *PtrType) {
462  if (!isImageRelative())
463  return PtrType;
464  return CGM.IntTy;
465  }
466 
467  llvm::StructType *getBaseClassDescriptorType() {
468  if (BaseClassDescriptorType)
469  return BaseClassDescriptorType;
470  llvm::Type *FieldTypes[] = {
471  getImageRelativeType(CGM.Int8PtrTy),
472  CGM.IntTy,
473  CGM.IntTy,
474  CGM.IntTy,
475  CGM.IntTy,
476  CGM.IntTy,
477  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
478  };
479  BaseClassDescriptorType = llvm::StructType::create(
480  CGM.getLLVMContext(), FieldTypes, "rtti.BaseClassDescriptor");
481  return BaseClassDescriptorType;
482  }
483 
484  llvm::StructType *getClassHierarchyDescriptorType() {
485  if (ClassHierarchyDescriptorType)
486  return ClassHierarchyDescriptorType;
487  // Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
488  ClassHierarchyDescriptorType = llvm::StructType::create(
489  CGM.getLLVMContext(), "rtti.ClassHierarchyDescriptor");
490  llvm::Type *FieldTypes[] = {
491  CGM.IntTy,
492  CGM.IntTy,
493  CGM.IntTy,
494  getImageRelativeType(
495  getBaseClassDescriptorType()->getPointerTo()->getPointerTo()),
496  };
497  ClassHierarchyDescriptorType->setBody(FieldTypes);
498  return ClassHierarchyDescriptorType;
499  }
500 
501  llvm::StructType *getCompleteObjectLocatorType() {
502  if (CompleteObjectLocatorType)
503  return CompleteObjectLocatorType;
504  CompleteObjectLocatorType = llvm::StructType::create(
505  CGM.getLLVMContext(), "rtti.CompleteObjectLocator");
506  llvm::Type *FieldTypes[] = {
507  CGM.IntTy,
508  CGM.IntTy,
509  CGM.IntTy,
510  getImageRelativeType(CGM.Int8PtrTy),
511  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
512  getImageRelativeType(CompleteObjectLocatorType),
513  };
514  llvm::ArrayRef<llvm::Type *> FieldTypesRef(FieldTypes);
515  if (!isImageRelative())
516  FieldTypesRef = FieldTypesRef.drop_back();
517  CompleteObjectLocatorType->setBody(FieldTypesRef);
518  return CompleteObjectLocatorType;
519  }
520 
521  llvm::GlobalVariable *getImageBase() {
522  StringRef Name = "__ImageBase";
523  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
524  return GV;
525 
526  auto *GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
527  /*isConstant=*/true,
529  /*Initializer=*/nullptr, Name);
530  CGM.setDSOLocal(GV);
531  return GV;
532  }
533 
534  llvm::Constant *getImageRelativeConstant(llvm::Constant *PtrVal) {
535  if (!isImageRelative())
536  return PtrVal;
537 
538  if (PtrVal->isNullValue())
539  return llvm::Constant::getNullValue(CGM.IntTy);
540 
541  llvm::Constant *ImageBaseAsInt =
542  llvm::ConstantExpr::getPtrToInt(getImageBase(), CGM.IntPtrTy);
543  llvm::Constant *PtrValAsInt =
544  llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
545  llvm::Constant *Diff =
546  llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
547  /*HasNUW=*/true, /*HasNSW=*/true);
548  return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
549  }
550 
551 private:
552  MicrosoftMangleContext &getMangleContext() {
553  return cast<MicrosoftMangleContext>(CodeGen::CGCXXABI::getMangleContext());
554  }
555 
556  llvm::Constant *getZeroInt() {
557  return llvm::ConstantInt::get(CGM.IntTy, 0);
558  }
559 
560  llvm::Constant *getAllOnesInt() {
561  return llvm::Constant::getAllOnesValue(CGM.IntTy);
562  }
563 
564  CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) override;
565 
566  void
567  GetNullMemberPointerFields(const MemberPointerType *MPT,
569 
570  /// Shared code for virtual base adjustment. Returns the offset from
571  /// the vbptr to the virtual base. Optionally returns the address of the
572  /// vbptr itself.
573  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
574  Address Base,
575  llvm::Value *VBPtrOffset,
576  llvm::Value *VBTableOffset,
577  llvm::Value **VBPtr = nullptr);
578 
579  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
580  Address Base,
581  int32_t VBPtrOffset,
582  int32_t VBTableOffset,
583  llvm::Value **VBPtr = nullptr) {
584  assert(VBTableOffset % 4 == 0 && "should be byte offset into table of i32s");
585  llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
586  *VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset);
587  return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr);
588  }
589 
590  std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
591  performBaseAdjustment(CodeGenFunction &CGF, Address Value,
592  QualType SrcRecordTy);
593 
594  /// Performs a full virtual base adjustment. Used to dereference
595  /// pointers to members of virtual bases.
596  llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const Expr *E,
597  const CXXRecordDecl *RD, Address Base,
598  llvm::Value *VirtualBaseAdjustmentOffset,
599  llvm::Value *VBPtrOffset /* optional */);
600 
601  /// Emits a full member pointer with the fields common to data and
602  /// function member pointers.
603  llvm::Constant *EmitFullMemberPointer(llvm::Constant *FirstField,
604  bool IsMemberFunction,
605  const CXXRecordDecl *RD,
606  CharUnits NonVirtualBaseAdjustment,
607  unsigned VBTableIndex);
608 
609  bool MemberPointerConstantIsNull(const MemberPointerType *MPT,
610  llvm::Constant *MP);
611 
612  /// - Initialize all vbptrs of 'this' with RD as the complete type.
613  void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD);
614 
615  /// Caching wrapper around VBTableBuilder::enumerateVBTables().
616  const VBTableGlobals &enumerateVBTables(const CXXRecordDecl *RD);
617 
618  /// Generate a thunk for calling a virtual member function MD.
619  llvm::Function *EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
620  const MethodVFTableLocation &ML);
621 
622 public:
623  llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
624 
625  bool isZeroInitializable(const MemberPointerType *MPT) override;
626 
627  bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
628  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
629  return RD->hasAttr<MSInheritanceAttr>();
630  }
631 
632  llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
633 
634  llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
635  CharUnits offset) override;
636  llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
637  llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
638 
639  llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
640  llvm::Value *L,
641  llvm::Value *R,
642  const MemberPointerType *MPT,
643  bool Inequality) override;
644 
645  llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
646  llvm::Value *MemPtr,
647  const MemberPointerType *MPT) override;
648 
649  llvm::Value *
650  EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
651  Address Base, llvm::Value *MemPtr,
652  const MemberPointerType *MPT) override;
653 
654  llvm::Value *EmitNonNullMemberPointerConversion(
655  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
658  CGBuilderTy &Builder);
659 
660  llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
661  const CastExpr *E,
662  llvm::Value *Src) override;
663 
664  llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
665  llvm::Constant *Src) override;
666 
667  llvm::Constant *EmitMemberPointerConversion(
668  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
670  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src);
671 
672  CGCallee
673  EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, const Expr *E,
674  Address This, llvm::Value *&ThisPtrForCall,
675  llvm::Value *MemPtr,
676  const MemberPointerType *MPT) override;
677 
678  void emitCXXStructor(GlobalDecl GD) override;
679 
680  llvm::StructType *getCatchableTypeType() {
681  if (CatchableTypeType)
682  return CatchableTypeType;
683  llvm::Type *FieldTypes[] = {
684  CGM.IntTy, // Flags
685  getImageRelativeType(CGM.Int8PtrTy), // TypeDescriptor
686  CGM.IntTy, // NonVirtualAdjustment
687  CGM.IntTy, // OffsetToVBPtr
688  CGM.IntTy, // VBTableIndex
689  CGM.IntTy, // Size
690  getImageRelativeType(CGM.Int8PtrTy) // CopyCtor
691  };
692  CatchableTypeType = llvm::StructType::create(
693  CGM.getLLVMContext(), FieldTypes, "eh.CatchableType");
694  return CatchableTypeType;
695  }
696 
697  llvm::StructType *getCatchableTypeArrayType(uint32_t NumEntries) {
698  llvm::StructType *&CatchableTypeArrayType =
699  CatchableTypeArrayTypeMap[NumEntries];
700  if (CatchableTypeArrayType)
701  return CatchableTypeArrayType;
702 
703  llvm::SmallString<23> CTATypeName("eh.CatchableTypeArray.");
704  CTATypeName += llvm::utostr(NumEntries);
705  llvm::Type *CTType =
706  getImageRelativeType(getCatchableTypeType()->getPointerTo());
707  llvm::Type *FieldTypes[] = {
708  CGM.IntTy, // NumEntries
709  llvm::ArrayType::get(CTType, NumEntries) // CatchableTypes
710  };
711  CatchableTypeArrayType =
712  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, CTATypeName);
713  return CatchableTypeArrayType;
714  }
715 
716  llvm::StructType *getThrowInfoType() {
717  if (ThrowInfoType)
718  return ThrowInfoType;
719  llvm::Type *FieldTypes[] = {
720  CGM.IntTy, // Flags
721  getImageRelativeType(CGM.Int8PtrTy), // CleanupFn
722  getImageRelativeType(CGM.Int8PtrTy), // ForwardCompat
723  getImageRelativeType(CGM.Int8PtrTy) // CatchableTypeArray
724  };
725  ThrowInfoType = llvm::StructType::create(CGM.getLLVMContext(), FieldTypes,
726  "eh.ThrowInfo");
727  return ThrowInfoType;
728  }
729 
730  llvm::FunctionCallee getThrowFn() {
731  // _CxxThrowException is passed an exception object and a ThrowInfo object
732  // which describes the exception.
733  llvm::Type *Args[] = {CGM.Int8PtrTy, getThrowInfoType()->getPointerTo()};
734  llvm::FunctionType *FTy =
735  llvm::FunctionType::get(CGM.VoidTy, Args, /*isVarArg=*/false);
736  llvm::FunctionCallee Throw =
737  CGM.CreateRuntimeFunction(FTy, "_CxxThrowException");
738  // _CxxThrowException is stdcall on 32-bit x86 platforms.
739  if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
740  if (auto *Fn = dyn_cast<llvm::Function>(Throw.getCallee()))
741  Fn->setCallingConv(llvm::CallingConv::X86_StdCall);
742  }
743  return Throw;
744  }
745 
746  llvm::Function *getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
747  CXXCtorType CT);
748 
749  llvm::Constant *getCatchableType(QualType T,
750  uint32_t NVOffset = 0,
751  int32_t VBPtrOffset = -1,
752  uint32_t VBIndex = 0);
753 
754  llvm::GlobalVariable *getCatchableTypeArray(QualType T);
755 
756  llvm::GlobalVariable *getThrowInfo(QualType T) override;
757 
758  std::pair<llvm::Value *, const CXXRecordDecl *>
759  LoadVTablePtr(CodeGenFunction &CGF, Address This,
760  const CXXRecordDecl *RD) override;
761 
762 private:
763  typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy;
764  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VTablesMapTy;
765  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalValue *> VFTablesMapTy;
766  /// All the vftables that have been referenced.
767  VFTablesMapTy VFTablesMap;
768  VTablesMapTy VTablesMap;
769 
770  /// This set holds the record decls we've deferred vtable emission for.
771  llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables;
772 
773 
774  /// All the vbtables which have been referenced.
775  llvm::DenseMap<const CXXRecordDecl *, VBTableGlobals> VBTablesMap;
776 
777  /// Info on the global variable used to guard initialization of static locals.
778  /// The BitIndex field is only used for externally invisible declarations.
779  struct GuardInfo {
780  GuardInfo() : Guard(nullptr), BitIndex(0) {}
781  llvm::GlobalVariable *Guard;
782  unsigned BitIndex;
783  };
784 
785  /// Map from DeclContext to the current guard variable. We assume that the
786  /// AST is visited in source code order.
787  llvm::DenseMap<const DeclContext *, GuardInfo> GuardVariableMap;
788  llvm::DenseMap<const DeclContext *, GuardInfo> ThreadLocalGuardVariableMap;
789  llvm::DenseMap<const DeclContext *, unsigned> ThreadSafeGuardNumMap;
790 
791  llvm::DenseMap<size_t, llvm::StructType *> TypeDescriptorTypeMap;
792  llvm::StructType *BaseClassDescriptorType;
793  llvm::StructType *ClassHierarchyDescriptorType;
794  llvm::StructType *CompleteObjectLocatorType;
795 
796  llvm::DenseMap<QualType, llvm::GlobalVariable *> CatchableTypeArrays;
797 
798  llvm::StructType *CatchableTypeType;
799  llvm::DenseMap<uint32_t, llvm::StructType *> CatchableTypeArrayTypeMap;
800  llvm::StructType *ThrowInfoType;
801 };
802 
803 }
804 
807  switch (CGM.getTarget().getTriple().getArch()) {
808  default:
809  // FIXME: Implement for other architectures.
810  return RAA_Default;
811 
812  case llvm::Triple::thumb:
813  // Use the simple Itanium rules for now.
814  // FIXME: This is incompatible with MSVC for arguments with a dtor and no
815  // copy ctor.
816  return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
817 
818  case llvm::Triple::x86:
819  // All record arguments are passed in memory on x86. Decide whether to
820  // construct the object directly in argument memory, or to construct the
821  // argument elsewhere and copy the bytes during the call.
822 
823  // If C++ prohibits us from making a copy, construct the arguments directly
824  // into argument memory.
825  if (!RD->canPassInRegisters())
826  return RAA_DirectInMemory;
827 
828  // Otherwise, construct the argument into a temporary and copy the bytes
829  // into the outgoing argument memory.
830  return RAA_Default;
831 
832  case llvm::Triple::x86_64:
833  case llvm::Triple::aarch64:
834  return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
835  }
836 
837  llvm_unreachable("invalid enum");
838 }
839 
840 void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
841  const CXXDeleteExpr *DE,
842  Address Ptr,
843  QualType ElementType,
844  const CXXDestructorDecl *Dtor) {
845  // FIXME: Provide a source location here even though there's no
846  // CXXMemberCallExpr for dtor call.
847  bool UseGlobalDelete = DE->isGlobalDelete();
848  CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
849  llvm::Value *MDThis = EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE);
850  if (UseGlobalDelete)
851  CGF.EmitDeleteCall(DE->getOperatorDelete(), MDThis, ElementType);
852 }
853 
854 void MicrosoftCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
855  llvm::Value *Args[] = {
856  llvm::ConstantPointerNull::get(CGM.Int8PtrTy),
857  llvm::ConstantPointerNull::get(getThrowInfoType()->getPointerTo())};
858  llvm::FunctionCallee Fn = getThrowFn();
859  if (isNoReturn)
860  CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, Args);
861  else
862  CGF.EmitRuntimeCallOrInvoke(Fn, Args);
863 }
864 
865 void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
866  const CXXCatchStmt *S) {
867  // In the MS ABI, the runtime handles the copy, and the catch handler is
868  // responsible for destruction.
869  VarDecl *CatchParam = S->getExceptionDecl();
870  llvm::BasicBlock *CatchPadBB = CGF.Builder.GetInsertBlock();
871  llvm::CatchPadInst *CPI =
872  cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
873  CGF.CurrentFuncletPad = CPI;
874 
875  // If this is a catch-all or the catch parameter is unnamed, we don't need to
876  // emit an alloca to the object.
877  if (!CatchParam || !CatchParam->getDeclName()) {
878  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
879  return;
880  }
881 
883  CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
884  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
885  CGF.EmitAutoVarCleanups(var);
886 }
887 
888 /// We need to perform a generic polymorphic operation (like a typeid
889 /// or a cast), which requires an object with a vfptr. Adjust the
890 /// address to point to an object with a vfptr.
891 std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
892 MicrosoftCXXABI::performBaseAdjustment(CodeGenFunction &CGF, Address Value,
893  QualType SrcRecordTy) {
894  Value = CGF.Builder.CreateBitCast(Value, CGF.Int8PtrTy);
895  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
896  const ASTContext &Context = getContext();
897 
898  // If the class itself has a vfptr, great. This check implicitly
899  // covers non-virtual base subobjects: a class with its own virtual
900  // functions would be a candidate to be a primary base.
901  if (Context.getASTRecordLayout(SrcDecl).hasExtendableVFPtr())
902  return std::make_tuple(Value, llvm::ConstantInt::get(CGF.Int32Ty, 0),
903  SrcDecl);
904 
905  // Okay, one of the vbases must have a vfptr, or else this isn't
906  // actually a polymorphic class.
907  const CXXRecordDecl *PolymorphicBase = nullptr;
908  for (auto &Base : SrcDecl->vbases()) {
909  const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
910  if (Context.getASTRecordLayout(BaseDecl).hasExtendableVFPtr()) {
911  PolymorphicBase = BaseDecl;
912  break;
913  }
914  }
915  assert(PolymorphicBase && "polymorphic class has no apparent vfptr?");
916 
918  GetVirtualBaseClassOffset(CGF, Value, SrcDecl, PolymorphicBase);
919  llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(Value.getPointer(), Offset);
920  CharUnits VBaseAlign =
921  CGF.CGM.getVBaseAlignment(Value.getAlignment(), SrcDecl, PolymorphicBase);
922  return std::make_tuple(Address(Ptr, VBaseAlign), Offset, PolymorphicBase);
923 }
924 
925 bool MicrosoftCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
926  QualType SrcRecordTy) {
927  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
928  return IsDeref &&
929  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
930 }
931 
932 static llvm::CallBase *emitRTtypeidCall(CodeGenFunction &CGF,
933  llvm::Value *Argument) {
934  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
935  llvm::FunctionType *FTy =
936  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false);
937  llvm::Value *Args[] = {Argument};
938  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(FTy, "__RTtypeid");
939  return CGF.EmitRuntimeCallOrInvoke(Fn, Args);
940 }
941 
942 void MicrosoftCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
943  llvm::CallBase *Call =
944  emitRTtypeidCall(CGF, llvm::Constant::getNullValue(CGM.VoidPtrTy));
945  Call->setDoesNotReturn();
946  CGF.Builder.CreateUnreachable();
947 }
948 
949 llvm::Value *MicrosoftCXXABI::EmitTypeid(CodeGenFunction &CGF,
950  QualType SrcRecordTy,
951  Address ThisPtr,
952  llvm::Type *StdTypeInfoPtrTy) {
953  std::tie(ThisPtr, std::ignore, std::ignore) =
954  performBaseAdjustment(CGF, ThisPtr, SrcRecordTy);
955  llvm::CallBase *Typeid = emitRTtypeidCall(CGF, ThisPtr.getPointer());
956  return CGF.Builder.CreateBitCast(Typeid, StdTypeInfoPtrTy);
957 }
958 
959 bool MicrosoftCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
960  QualType SrcRecordTy) {
961  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
962  return SrcIsPtr &&
963  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
964 }
965 
966 llvm::Value *MicrosoftCXXABI::EmitDynamicCastCall(
967  CodeGenFunction &CGF, Address This, QualType SrcRecordTy,
968  QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
969  llvm::Type *DestLTy = CGF.ConvertType(DestTy);
970 
971  llvm::Value *SrcRTTI =
973  llvm::Value *DestRTTI =
974  CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
975 
977  std::tie(This, Offset, std::ignore) =
978  performBaseAdjustment(CGF, This, SrcRecordTy);
979  llvm::Value *ThisPtr = This.getPointer();
980  Offset = CGF.Builder.CreateTrunc(Offset, CGF.Int32Ty);
981 
982  // PVOID __RTDynamicCast(
983  // PVOID inptr,
984  // LONG VfDelta,
985  // PVOID SrcType,
986  // PVOID TargetType,
987  // BOOL isReference)
988  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy, CGF.Int32Ty, CGF.Int8PtrTy,
989  CGF.Int8PtrTy, CGF.Int32Ty};
990  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
991  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
992  "__RTDynamicCast");
993  llvm::Value *Args[] = {
994  ThisPtr, Offset, SrcRTTI, DestRTTI,
995  llvm::ConstantInt::get(CGF.Int32Ty, DestTy->isReferenceType())};
996  ThisPtr = CGF.EmitRuntimeCallOrInvoke(Function, Args);
997  return CGF.Builder.CreateBitCast(ThisPtr, DestLTy);
998 }
999 
1000 llvm::Value *
1001 MicrosoftCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
1002  QualType SrcRecordTy,
1003  QualType DestTy) {
1004  std::tie(Value, std::ignore, std::ignore) =
1005  performBaseAdjustment(CGF, Value, SrcRecordTy);
1006 
1007  // PVOID __RTCastToVoid(
1008  // PVOID inptr)
1009  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
1010  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
1011  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
1012  "__RTCastToVoid");
1013  llvm::Value *Args[] = {Value.getPointer()};
1014  return CGF.EmitRuntimeCall(Function, Args);
1015 }
1016 
1017 bool MicrosoftCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
1018  return false;
1019 }
1020 
1021 llvm::Value *MicrosoftCXXABI::GetVirtualBaseClassOffset(
1022  CodeGenFunction &CGF, Address This, const CXXRecordDecl *ClassDecl,
1023  const CXXRecordDecl *BaseClassDecl) {
1024  const ASTContext &Context = getContext();
1025  int64_t VBPtrChars =
1026  Context.getASTRecordLayout(ClassDecl).getVBPtrOffset().getQuantity();
1027  llvm::Value *VBPtrOffset = llvm::ConstantInt::get(CGM.PtrDiffTy, VBPtrChars);
1028  CharUnits IntSize = Context.getTypeSizeInChars(Context.IntTy);
1029  CharUnits VBTableChars =
1030  IntSize *
1031  CGM.getMicrosoftVTableContext().getVBTableIndex(ClassDecl, BaseClassDecl);
1032  llvm::Value *VBTableOffset =
1033  llvm::ConstantInt::get(CGM.IntTy, VBTableChars.getQuantity());
1034 
1035  llvm::Value *VBPtrToNewBase =
1036  GetVBaseOffsetFromVBPtr(CGF, This, VBPtrOffset, VBTableOffset);
1037  VBPtrToNewBase =
1038  CGF.Builder.CreateSExtOrBitCast(VBPtrToNewBase, CGM.PtrDiffTy);
1039  return CGF.Builder.CreateNSWAdd(VBPtrOffset, VBPtrToNewBase);
1040 }
1041 
1042 bool MicrosoftCXXABI::HasThisReturn(GlobalDecl GD) const {
1043  return isa<CXXConstructorDecl>(GD.getDecl());
1044 }
1045 
1046 static bool isDeletingDtor(GlobalDecl GD) {
1047  return isa<CXXDestructorDecl>(GD.getDecl()) &&
1048  GD.getDtorType() == Dtor_Deleting;
1049 }
1050 
1051 bool MicrosoftCXXABI::hasMostDerivedReturn(GlobalDecl GD) const {
1052  return isDeletingDtor(GD);
1053 }
1054 
1055 static bool IsSizeGreaterThan128(const CXXRecordDecl *RD) {
1056  return RD->getASTContext().getTypeSize(RD->getTypeForDecl()) > 128;
1057 }
1058 
1060  // For AArch64, we use the C++14 definition of an aggregate, so we also
1061  // check for:
1062  // No private or protected non static data members.
1063  // No base classes
1064  // No virtual functions
1065  // Additionally, we need to ensure that there is a trivial copy assignment
1066  // operator, a trivial destructor and no user-provided constructors.
1067  if (RD->hasProtectedFields() || RD->hasPrivateFields())
1068  return true;
1069  if (RD->getNumBases() > 0)
1070  return true;
1071  if (RD->isPolymorphic())
1072  return true;
1073  if (RD->hasNonTrivialCopyAssignment())
1074  return true;
1075  for (const CXXConstructorDecl *Ctor : RD->ctors())
1076  if (Ctor->isUserProvided())
1077  return true;
1078  if (RD->hasNonTrivialDestructor())
1079  return true;
1080  return false;
1081 }
1082 
1084  const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
1085  if (!RD)
1086  return false;
1087 
1088  bool isAArch64 = CGM.getTarget().getTriple().isAArch64();
1089  bool isSimple = !isAArch64 || !hasMicrosoftABIRestrictions(RD);
1090  bool isIndirectReturn =
1091  isAArch64 ? (!RD->canPassInRegisters() ||
1093  : !RD->isPOD();
1094  bool isInstanceMethod = FI.isInstanceMethod();
1095 
1096  if (isIndirectReturn || !isSimple || isInstanceMethod) {
1097  CharUnits Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
1098  FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
1099  FI.getReturnInfo().setSRetAfterThis(isInstanceMethod);
1100 
1101  FI.getReturnInfo().setInReg(isAArch64 &&
1102  !(isSimple && IsSizeGreaterThan128(RD)));
1103 
1104  return true;
1105  }
1106 
1107  // Otherwise, use the C ABI rules.
1108  return false;
1109 }
1110 
1111 llvm::BasicBlock *
1112 MicrosoftCXXABI::EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
1113  const CXXRecordDecl *RD) {
1114  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1115  assert(IsMostDerivedClass &&
1116  "ctor for a class with virtual bases must have an implicit parameter");
1117  llvm::Value *IsCompleteObject =
1118  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1119 
1120  llvm::BasicBlock *CallVbaseCtorsBB = CGF.createBasicBlock("ctor.init_vbases");
1121  llvm::BasicBlock *SkipVbaseCtorsBB = CGF.createBasicBlock("ctor.skip_vbases");
1122  CGF.Builder.CreateCondBr(IsCompleteObject,
1123  CallVbaseCtorsBB, SkipVbaseCtorsBB);
1124 
1125  CGF.EmitBlock(CallVbaseCtorsBB);
1126 
1127  // Fill in the vbtable pointers here.
1128  EmitVBPtrStores(CGF, RD);
1129 
1130  // CGF will put the base ctor calls in this basic block for us later.
1131 
1132  return SkipVbaseCtorsBB;
1133 }
1134 
1135 llvm::BasicBlock *
1136 MicrosoftCXXABI::EmitDtorCompleteObjectHandler(CodeGenFunction &CGF) {
1137  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1138  assert(IsMostDerivedClass &&
1139  "ctor for a class with virtual bases must have an implicit parameter");
1140  llvm::Value *IsCompleteObject =
1141  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1142 
1143  llvm::BasicBlock *CallVbaseDtorsBB = CGF.createBasicBlock("Dtor.dtor_vbases");
1144  llvm::BasicBlock *SkipVbaseDtorsBB = CGF.createBasicBlock("Dtor.skip_vbases");
1145  CGF.Builder.CreateCondBr(IsCompleteObject,
1146  CallVbaseDtorsBB, SkipVbaseDtorsBB);
1147 
1148  CGF.EmitBlock(CallVbaseDtorsBB);
1149  // CGF will put the base dtor calls in this basic block for us later.
1150 
1151  return SkipVbaseDtorsBB;
1152 }
1153 
1154 void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers(
1155  CodeGenFunction &CGF, const CXXRecordDecl *RD) {
1156  // In most cases, an override for a vbase virtual method can adjust
1157  // the "this" parameter by applying a constant offset.
1158  // However, this is not enough while a constructor or a destructor of some
1159  // class X is being executed if all the following conditions are met:
1160  // - X has virtual bases, (1)
1161  // - X overrides a virtual method M of a vbase Y, (2)
1162  // - X itself is a vbase of the most derived class.
1163  //
1164  // If (1) and (2) are true, the vtorDisp for vbase Y is a hidden member of X
1165  // which holds the extra amount of "this" adjustment we must do when we use
1166  // the X vftables (i.e. during X ctor or dtor).
1167  // Outside the ctors and dtors, the values of vtorDisps are zero.
1168 
1169  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1170  typedef ASTRecordLayout::VBaseOffsetsMapTy VBOffsets;
1171  const VBOffsets &VBaseMap = Layout.getVBaseOffsetsMap();
1172  CGBuilderTy &Builder = CGF.Builder;
1173 
1174  unsigned AS = getThisAddress(CGF).getAddressSpace();
1175  llvm::Value *Int8This = nullptr; // Initialize lazily.
1176 
1177  for (const CXXBaseSpecifier &S : RD->vbases()) {
1178  const CXXRecordDecl *VBase = S.getType()->getAsCXXRecordDecl();
1179  auto I = VBaseMap.find(VBase);
1180  assert(I != VBaseMap.end());
1181  if (!I->second.hasVtorDisp())
1182  continue;
1183 
1184  llvm::Value *VBaseOffset =
1185  GetVirtualBaseClassOffset(CGF, getThisAddress(CGF), RD, VBase);
1186  uint64_t ConstantVBaseOffset = I->second.VBaseOffset.getQuantity();
1187 
1188  // vtorDisp_for_vbase = vbptr[vbase_idx] - offsetof(RD, vbase).
1189  llvm::Value *VtorDispValue = Builder.CreateSub(
1190  VBaseOffset, llvm::ConstantInt::get(CGM.PtrDiffTy, ConstantVBaseOffset),
1191  "vtordisp.value");
1192  VtorDispValue = Builder.CreateTruncOrBitCast(VtorDispValue, CGF.Int32Ty);
1193 
1194  if (!Int8This)
1195  Int8This = Builder.CreateBitCast(getThisValue(CGF),
1196  CGF.Int8Ty->getPointerTo(AS));
1197  llvm::Value *VtorDispPtr = Builder.CreateInBoundsGEP(Int8This, VBaseOffset);
1198  // vtorDisp is always the 32-bits before the vbase in the class layout.
1199  VtorDispPtr = Builder.CreateConstGEP1_32(VtorDispPtr, -4);
1200  VtorDispPtr = Builder.CreateBitCast(
1201  VtorDispPtr, CGF.Int32Ty->getPointerTo(AS), "vtordisp.ptr");
1202 
1203  Builder.CreateAlignedStore(VtorDispValue, VtorDispPtr,
1205  }
1206 }
1207 
1208 static bool hasDefaultCXXMethodCC(ASTContext &Context,
1209  const CXXMethodDecl *MD) {
1210  CallingConv ExpectedCallingConv = Context.getDefaultCallingConvention(
1211  /*IsVariadic=*/false, /*IsCXXMethod=*/true);
1212  CallingConv ActualCallingConv =
1213  MD->getType()->castAs<FunctionProtoType>()->getCallConv();
1214  return ExpectedCallingConv == ActualCallingConv;
1215 }
1216 
1217 void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
1218  // There's only one constructor type in this ABI.
1219  CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete));
1220 
1221  // Exported default constructors either have a simple call-site where they use
1222  // the typical calling convention and have a single 'this' pointer for an
1223  // argument -or- they get a wrapper function which appropriately thunks to the
1224  // real default constructor. This thunk is the default constructor closure.
1225  if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor())
1226  if (!hasDefaultCXXMethodCC(getContext(), D) || D->getNumParams() != 0) {
1227  llvm::Function *Fn = getAddrOfCXXCtorClosure(D, Ctor_DefaultClosure);
1228  Fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
1229  CGM.setGVProperties(Fn, D);
1230  }
1231 }
1232 
1233 void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF,
1234  const CXXRecordDecl *RD) {
1235  Address This = getThisAddress(CGF);
1236  This = CGF.Builder.CreateElementBitCast(This, CGM.Int8Ty, "this.int8");
1237  const ASTContext &Context = getContext();
1238  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
1239 
1240  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
1241  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
1242  const std::unique_ptr<VPtrInfo> &VBT = (*VBGlobals.VBTables)[I];
1243  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
1244  const ASTRecordLayout &SubobjectLayout =
1245  Context.getASTRecordLayout(VBT->IntroducingObject);
1246  CharUnits Offs = VBT->NonVirtualOffset;
1247  Offs += SubobjectLayout.getVBPtrOffset();
1248  if (VBT->getVBaseWithVPtr())
1249  Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
1250  Address VBPtr = CGF.Builder.CreateConstInBoundsByteGEP(This, Offs);
1251  llvm::Value *GVPtr =
1252  CGF.Builder.CreateConstInBoundsGEP2_32(GV->getValueType(), GV, 0, 0);
1253  VBPtr = CGF.Builder.CreateElementBitCast(VBPtr, GVPtr->getType(),
1254  "vbptr." + VBT->ObjectWithVPtr->getName());
1255  CGF.Builder.CreateStore(GVPtr, VBPtr);
1256  }
1257 }
1258 
1260 MicrosoftCXXABI::buildStructorSignature(GlobalDecl GD,
1261  SmallVectorImpl<CanQualType> &ArgTys) {
1262  AddedStructorArgs Added;
1263  // TODO: 'for base' flag
1264  if (isa<CXXDestructorDecl>(GD.getDecl()) &&
1265  GD.getDtorType() == Dtor_Deleting) {
1266  // The scalar deleting destructor takes an implicit int parameter.
1267  ArgTys.push_back(getContext().IntTy);
1268  ++Added.Suffix;
1269  }
1270  auto *CD = dyn_cast<CXXConstructorDecl>(GD.getDecl());
1271  if (!CD)
1272  return Added;
1273 
1274  // All parameters are already in place except is_most_derived, which goes
1275  // after 'this' if it's variadic and last if it's not.
1276 
1277  const CXXRecordDecl *Class = CD->getParent();
1278  const FunctionProtoType *FPT = CD->getType()->castAs<FunctionProtoType>();
1279  if (Class->getNumVBases()) {
1280  if (FPT->isVariadic()) {
1281  ArgTys.insert(ArgTys.begin() + 1, getContext().IntTy);
1282  ++Added.Prefix;
1283  } else {
1284  ArgTys.push_back(getContext().IntTy);
1285  ++Added.Suffix;
1286  }
1287  }
1288 
1289  return Added;
1290 }
1291 
1292 void MicrosoftCXXABI::setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
1293  const CXXDestructorDecl *Dtor,
1294  CXXDtorType DT) const {
1295  // Deleting destructor variants are never imported or exported. Give them the
1296  // default storage class.
1297  if (DT == Dtor_Deleting) {
1298  GV->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
1299  } else {
1300  const NamedDecl *ND = Dtor;
1301  CGM.setDLLImportDLLExport(GV, ND);
1302  }
1303 }
1304 
1305 llvm::GlobalValue::LinkageTypes MicrosoftCXXABI::getCXXDestructorLinkage(
1306  GVALinkage Linkage, const CXXDestructorDecl *Dtor, CXXDtorType DT) const {
1307  // Internal things are always internal, regardless of attributes. After this,
1308  // we know the thunk is externally visible.
1309  if (Linkage == GVA_Internal)
1311 
1312  switch (DT) {
1313  case Dtor_Base:
1314  // The base destructor most closely tracks the user-declared constructor, so
1315  // we delegate back to the normal declarator case.
1316  return CGM.getLLVMLinkageForDeclarator(Dtor, Linkage,
1317  /*IsConstantVariable=*/false);
1318  case Dtor_Complete:
1319  // The complete destructor is like an inline function, but it may be
1320  // imported and therefore must be exported as well. This requires changing
1321  // the linkage if a DLL attribute is present.
1322  if (Dtor->hasAttr<DLLExportAttr>())
1323  return llvm::GlobalValue::WeakODRLinkage;
1324  if (Dtor->hasAttr<DLLImportAttr>())
1325  return llvm::GlobalValue::AvailableExternallyLinkage;
1326  return llvm::GlobalValue::LinkOnceODRLinkage;
1327  case Dtor_Deleting:
1328  // Deleting destructors are like inline functions. They have vague linkage
1329  // and are emitted everywhere they are used. They are internal if the class
1330  // is internal.
1331  return llvm::GlobalValue::LinkOnceODRLinkage;
1332  case Dtor_Comdat:
1333  llvm_unreachable("MS C++ ABI does not support comdat dtors");
1334  }
1335  llvm_unreachable("invalid dtor type");
1336 }
1337 
1338 void MicrosoftCXXABI::EmitCXXDestructors(const CXXDestructorDecl *D) {
1339  // The TU defining a dtor is only guaranteed to emit a base destructor. All
1340  // other destructor variants are delegating thunks.
1341  CGM.EmitGlobal(GlobalDecl(D, Dtor_Base));
1342 }
1343 
1344 CharUnits
1345 MicrosoftCXXABI::getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
1346  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1347 
1348  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1349  // Complete destructors take a pointer to the complete object as a
1350  // parameter, thus don't need this adjustment.
1351  if (GD.getDtorType() == Dtor_Complete)
1352  return CharUnits();
1353 
1354  // There's no Dtor_Base in vftable but it shares the this adjustment with
1355  // the deleting one, so look it up instead.
1356  GD = GlobalDecl(DD, Dtor_Deleting);
1357  }
1358 
1360  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(GD);
1361  CharUnits Adjustment = ML.VFPtrOffset;
1362 
1363  // Normal virtual instance methods need to adjust from the vfptr that first
1364  // defined the virtual method to the virtual base subobject, but destructors
1365  // do not. The vector deleting destructor thunk applies this adjustment for
1366  // us if necessary.
1367  if (isa<CXXDestructorDecl>(MD))
1368  Adjustment = CharUnits::Zero();
1369 
1370  if (ML.VBase) {
1371  const ASTRecordLayout &DerivedLayout =
1372  getContext().getASTRecordLayout(MD->getParent());
1373  Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase);
1374  }
1375 
1376  return Adjustment;
1377 }
1378 
1379 Address MicrosoftCXXABI::adjustThisArgumentForVirtualFunctionCall(
1380  CodeGenFunction &CGF, GlobalDecl GD, Address This,
1381  bool VirtualCall) {
1382  if (!VirtualCall) {
1383  // If the call of a virtual function is not virtual, we just have to
1384  // compensate for the adjustment the virtual function does in its prologue.
1385  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD);
1386  if (Adjustment.isZero())
1387  return This;
1388 
1389  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
1390  assert(Adjustment.isPositive());
1391  return CGF.Builder.CreateConstByteGEP(This, Adjustment);
1392  }
1393 
1394  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1395 
1396  GlobalDecl LookupGD = GD;
1397  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1398  // Complete dtors take a pointer to the complete object,
1399  // thus don't need adjustment.
1400  if (GD.getDtorType() == Dtor_Complete)
1401  return This;
1402 
1403  // There's only Dtor_Deleting in vftable but it shares the this adjustment
1404  // with the base one, so look up the deleting one instead.
1405  LookupGD = GlobalDecl(DD, Dtor_Deleting);
1406  }
1408  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
1409 
1410  CharUnits StaticOffset = ML.VFPtrOffset;
1411 
1412  // Base destructors expect 'this' to point to the beginning of the base
1413  // subobject, not the first vfptr that happens to contain the virtual dtor.
1414  // However, we still need to apply the virtual base adjustment.
1415  if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
1416  StaticOffset = CharUnits::Zero();
1417 
1418  Address Result = This;
1419  if (ML.VBase) {
1420  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1421 
1422  const CXXRecordDecl *Derived = MD->getParent();
1423  const CXXRecordDecl *VBase = ML.VBase;
1424  llvm::Value *VBaseOffset =
1425  GetVirtualBaseClassOffset(CGF, Result, Derived, VBase);
1426  llvm::Value *VBasePtr =
1427  CGF.Builder.CreateInBoundsGEP(Result.getPointer(), VBaseOffset);
1428  CharUnits VBaseAlign =
1429  CGF.CGM.getVBaseAlignment(Result.getAlignment(), Derived, VBase);
1430  Result = Address(VBasePtr, VBaseAlign);
1431  }
1432  if (!StaticOffset.isZero()) {
1433  assert(StaticOffset.isPositive());
1434  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1435  if (ML.VBase) {
1436  // Non-virtual adjustment might result in a pointer outside the allocated
1437  // object, e.g. if the final overrider class is laid out after the virtual
1438  // base that declares a method in the most derived class.
1439  // FIXME: Update the code that emits this adjustment in thunks prologues.
1440  Result = CGF.Builder.CreateConstByteGEP(Result, StaticOffset);
1441  } else {
1442  Result = CGF.Builder.CreateConstInBoundsByteGEP(Result, StaticOffset);
1443  }
1444  }
1445  return Result;
1446 }
1447 
1448 void MicrosoftCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
1449  QualType &ResTy,
1450  FunctionArgList &Params) {
1451  ASTContext &Context = getContext();
1452  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1453  assert(isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD));
1454  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1455  auto *IsMostDerived = ImplicitParamDecl::Create(
1456  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1457  &Context.Idents.get("is_most_derived"), Context.IntTy,
1459  // The 'most_derived' parameter goes second if the ctor is variadic and last
1460  // if it's not. Dtors can't be variadic.
1461  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
1462  if (FPT->isVariadic())
1463  Params.insert(Params.begin() + 1, IsMostDerived);
1464  else
1465  Params.push_back(IsMostDerived);
1466  getStructorImplicitParamDecl(CGF) = IsMostDerived;
1467  } else if (isDeletingDtor(CGF.CurGD)) {
1468  auto *ShouldDelete = ImplicitParamDecl::Create(
1469  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1470  &Context.Idents.get("should_call_delete"), Context.IntTy,
1472  Params.push_back(ShouldDelete);
1473  getStructorImplicitParamDecl(CGF) = ShouldDelete;
1474  }
1475 }
1476 
1477 void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
1478  // Naked functions have no prolog.
1479  if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
1480  return;
1481 
1482  // Overridden virtual methods of non-primary bases need to adjust the incoming
1483  // 'this' pointer in the prologue. In this hierarchy, C::b will subtract
1484  // sizeof(void*) to adjust from B* to C*:
1485  // struct A { virtual void a(); };
1486  // struct B { virtual void b(); };
1487  // struct C : A, B { virtual void b(); };
1488  //
1489  // Leave the value stored in the 'this' alloca unadjusted, so that the
1490  // debugger sees the unadjusted value. Microsoft debuggers require this, and
1491  // will apply the ThisAdjustment in the method type information.
1492  // FIXME: Do something better for DWARF debuggers, which won't expect this,
1493  // without making our codegen depend on debug info settings.
1494  llvm::Value *This = loadIncomingCXXThis(CGF);
1495  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1496  if (!CGF.CurFuncIsThunk && MD->isVirtual()) {
1497  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD);
1498  if (!Adjustment.isZero()) {
1499  unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
1500  llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS),
1501  *thisTy = This->getType();
1502  This = CGF.Builder.CreateBitCast(This, charPtrTy);
1503  assert(Adjustment.isPositive());
1504  This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This,
1505  -Adjustment.getQuantity());
1506  This = CGF.Builder.CreateBitCast(This, thisTy, "this.adjusted");
1507  }
1508  }
1509  setCXXABIThisValue(CGF, This);
1510 
1511  // If this is a function that the ABI specifies returns 'this', initialize
1512  // the return slot to 'this' at the start of the function.
1513  //
1514  // Unlike the setting of return types, this is done within the ABI
1515  // implementation instead of by clients of CGCXXABI because:
1516  // 1) getThisValue is currently protected
1517  // 2) in theory, an ABI could implement 'this' returns some other way;
1518  // HasThisReturn only specifies a contract, not the implementation
1519  if (HasThisReturn(CGF.CurGD))
1520  CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
1521  else if (hasMostDerivedReturn(CGF.CurGD))
1522  CGF.Builder.CreateStore(CGF.EmitCastToVoidPtr(getThisValue(CGF)),
1523  CGF.ReturnValue);
1524 
1525  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1526  assert(getStructorImplicitParamDecl(CGF) &&
1527  "no implicit parameter for a constructor with virtual bases?");
1528  getStructorImplicitParamValue(CGF)
1529  = CGF.Builder.CreateLoad(
1530  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1531  "is_most_derived");
1532  }
1533 
1534  if (isDeletingDtor(CGF.CurGD)) {
1535  assert(getStructorImplicitParamDecl(CGF) &&
1536  "no implicit parameter for a deleting destructor?");
1537  getStructorImplicitParamValue(CGF)
1538  = CGF.Builder.CreateLoad(
1539  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1540  "should_call_delete");
1541  }
1542 }
1543 
1544 CGCXXABI::AddedStructorArgs MicrosoftCXXABI::addImplicitConstructorArgs(
1546  bool ForVirtualBase, bool Delegating, CallArgList &Args) {
1547  assert(Type == Ctor_Complete || Type == Ctor_Base);
1548 
1549  // Check if we need a 'most_derived' parameter.
1550  if (!D->getParent()->getNumVBases())
1551  return AddedStructorArgs{};
1552 
1553  // Add the 'most_derived' argument second if we are variadic or last if not.
1554  const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
1555  llvm::Value *MostDerivedArg;
1556  if (Delegating) {
1557  MostDerivedArg = getStructorImplicitParamValue(CGF);
1558  } else {
1559  MostDerivedArg = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete);
1560  }
1561  RValue RV = RValue::get(MostDerivedArg);
1562  if (FPT->isVariadic()) {
1563  Args.insert(Args.begin() + 1, CallArg(RV, getContext().IntTy));
1564  return AddedStructorArgs::prefix(1);
1565  }
1566  Args.add(RV, getContext().IntTy);
1567  return AddedStructorArgs::suffix(1);
1568 }
1569 
1570 void MicrosoftCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
1571  const CXXDestructorDecl *DD,
1572  CXXDtorType Type, bool ForVirtualBase,
1573  bool Delegating, Address This,
1574  QualType ThisTy) {
1575  // Use the base destructor variant in place of the complete destructor variant
1576  // if the class has no virtual bases. This effectively implements some of the
1577  // -mconstructor-aliases optimization, but as part of the MS C++ ABI.
1578  if (Type == Dtor_Complete && DD->getParent()->getNumVBases() == 0)
1579  Type = Dtor_Base;
1580 
1581  GlobalDecl GD(DD, Type);
1582  CGCallee Callee = CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD), GD);
1583 
1584  if (DD->isVirtual()) {
1585  assert(Type != CXXDtorType::Dtor_Deleting &&
1586  "The deleting destructor should only be called via a virtual call");
1587  This = adjustThisArgumentForVirtualFunctionCall(CGF, GlobalDecl(DD, Type),
1588  This, false);
1589  }
1590 
1591  llvm::BasicBlock *BaseDtorEndBB = nullptr;
1592  if (ForVirtualBase && isa<CXXConstructorDecl>(CGF.CurCodeDecl)) {
1593  BaseDtorEndBB = EmitDtorCompleteObjectHandler(CGF);
1594  }
1595 
1596  CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
1597  /*ImplicitParam=*/nullptr,
1598  /*ImplicitParamTy=*/QualType(), nullptr);
1599  if (BaseDtorEndBB) {
1600  // Complete object handler should continue to be the remaining
1601  CGF.Builder.CreateBr(BaseDtorEndBB);
1602  CGF.EmitBlock(BaseDtorEndBB);
1603  }
1604 }
1605 
1606 void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
1607  const CXXRecordDecl *RD,
1608  llvm::GlobalVariable *VTable) {
1609  if (!CGM.getCodeGenOpts().LTOUnit)
1610  return;
1611 
1612  // The location of the first virtual function pointer in the virtual table,
1613  // aka the "address point" on Itanium. This is at offset 0 if RTTI is
1614  // disabled, or sizeof(void*) if RTTI is enabled.
1615  CharUnits AddressPoint =
1616  getContext().getLangOpts().RTTIData
1617  ? getContext().toCharUnitsFromBits(
1618  getContext().getTargetInfo().getPointerWidth(0))
1619  : CharUnits::Zero();
1620 
1621  if (Info.PathToIntroducingObject.empty()) {
1622  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1623  return;
1624  }
1625 
1626  // Add a bitset entry for the least derived base belonging to this vftable.
1627  CGM.AddVTableTypeMetadata(VTable, AddressPoint,
1628  Info.PathToIntroducingObject.back());
1629 
1630  // Add a bitset entry for each derived class that is laid out at the same
1631  // offset as the least derived base.
1632  for (unsigned I = Info.PathToIntroducingObject.size() - 1; I != 0; --I) {
1633  const CXXRecordDecl *DerivedRD = Info.PathToIntroducingObject[I - 1];
1634  const CXXRecordDecl *BaseRD = Info.PathToIntroducingObject[I];
1635 
1636  const ASTRecordLayout &Layout =
1637  getContext().getASTRecordLayout(DerivedRD);
1638  CharUnits Offset;
1639  auto VBI = Layout.getVBaseOffsetsMap().find(BaseRD);
1640  if (VBI == Layout.getVBaseOffsetsMap().end())
1641  Offset = Layout.getBaseClassOffset(BaseRD);
1642  else
1643  Offset = VBI->second.VBaseOffset;
1644  if (!Offset.isZero())
1645  return;
1646  CGM.AddVTableTypeMetadata(VTable, AddressPoint, DerivedRD);
1647  }
1648 
1649  // Finally do the same for the most derived class.
1650  if (Info.FullOffsetInMDC.isZero())
1651  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1652 }
1653 
1654 void MicrosoftCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
1655  const CXXRecordDecl *RD) {
1656  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1657  const VPtrInfoVector &VFPtrs = VFTContext.getVFPtrOffsets(RD);
1658 
1659  for (const std::unique_ptr<VPtrInfo>& Info : VFPtrs) {
1660  llvm::GlobalVariable *VTable = getAddrOfVTable(RD, Info->FullOffsetInMDC);
1661  if (VTable->hasInitializer())
1662  continue;
1663 
1664  const VTableLayout &VTLayout =
1665  VFTContext.getVFTableLayout(RD, Info->FullOffsetInMDC);
1666 
1667  llvm::Constant *RTTI = nullptr;
1668  if (any_of(VTLayout.vtable_components(),
1669  [](const VTableComponent &VTC) { return VTC.isRTTIKind(); }))
1670  RTTI = getMSCompleteObjectLocator(RD, *Info);
1671 
1672  ConstantInitBuilder Builder(CGM);
1673  auto Components = Builder.beginStruct();
1674  CGVT.createVTableInitializer(Components, VTLayout, RTTI);
1675  Components.finishAndSetAsInitializer(VTable);
1676 
1677  emitVTableTypeMetadata(*Info, RD, VTable);
1678  }
1679 }
1680 
1681 bool MicrosoftCXXABI::isVirtualOffsetNeededForVTableField(
1683  return Vptr.NearestVBase != nullptr;
1684 }
1685 
1686 llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor(
1687  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
1688  const CXXRecordDecl *NearestVBase) {
1689  llvm::Constant *VTableAddressPoint = getVTableAddressPoint(Base, VTableClass);
1690  if (!VTableAddressPoint) {
1691  assert(Base.getBase()->getNumVBases() &&
1692  !getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr());
1693  }
1694  return VTableAddressPoint;
1695 }
1696 
1698  const CXXRecordDecl *RD, const VPtrInfo &VFPtr,
1699  SmallString<256> &Name) {
1700  llvm::raw_svector_ostream Out(Name);
1701  MangleContext.mangleCXXVFTable(RD, VFPtr.MangledPath, Out);
1702 }
1703 
1704 llvm::Constant *
1705 MicrosoftCXXABI::getVTableAddressPoint(BaseSubobject Base,
1706  const CXXRecordDecl *VTableClass) {
1707  (void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
1708  VFTableIdTy ID(VTableClass, Base.getBaseOffset());
1709  return VFTablesMap[ID];
1710 }
1711 
1712 llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
1713  BaseSubobject Base, const CXXRecordDecl *VTableClass) {
1714  llvm::Constant *VFTable = getVTableAddressPoint(Base, VTableClass);
1715  assert(VFTable && "Couldn't find a vftable for the given base?");
1716  return VFTable;
1717 }
1718 
1719 llvm::GlobalVariable *MicrosoftCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
1720  CharUnits VPtrOffset) {
1721  // getAddrOfVTable may return 0 if asked to get an address of a vtable which
1722  // shouldn't be used in the given record type. We want to cache this result in
1723  // VFTablesMap, thus a simple zero check is not sufficient.
1724 
1725  VFTableIdTy ID(RD, VPtrOffset);
1726  VTablesMapTy::iterator I;
1727  bool Inserted;
1728  std::tie(I, Inserted) = VTablesMap.insert(std::make_pair(ID, nullptr));
1729  if (!Inserted)
1730  return I->second;
1731 
1732  llvm::GlobalVariable *&VTable = I->second;
1733 
1734  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
1735  const VPtrInfoVector &VFPtrs = VTContext.getVFPtrOffsets(RD);
1736 
1737  if (DeferredVFTables.insert(RD).second) {
1738  // We haven't processed this record type before.
1739  // Queue up this vtable for possible deferred emission.
1740  CGM.addDeferredVTable(RD);
1741 
1742 #ifndef NDEBUG
1743  // Create all the vftables at once in order to make sure each vftable has
1744  // a unique mangled name.
1745  llvm::StringSet<> ObservedMangledNames;
1746  for (size_t J = 0, F = VFPtrs.size(); J != F; ++J) {
1747  SmallString<256> Name;
1748  mangleVFTableName(getMangleContext(), RD, *VFPtrs[J], Name);
1749  if (!ObservedMangledNames.insert(Name.str()).second)
1750  llvm_unreachable("Already saw this mangling before?");
1751  }
1752 #endif
1753  }
1754 
1755  const std::unique_ptr<VPtrInfo> *VFPtrI = std::find_if(
1756  VFPtrs.begin(), VFPtrs.end(), [&](const std::unique_ptr<VPtrInfo>& VPI) {
1757  return VPI->FullOffsetInMDC == VPtrOffset;
1758  });
1759  if (VFPtrI == VFPtrs.end()) {
1760  VFTablesMap[ID] = nullptr;
1761  return nullptr;
1762  }
1763  const std::unique_ptr<VPtrInfo> &VFPtr = *VFPtrI;
1764 
1765  SmallString<256> VFTableName;
1766  mangleVFTableName(getMangleContext(), RD, *VFPtr, VFTableName);
1767 
1768  // Classes marked __declspec(dllimport) need vftables generated on the
1769  // import-side in order to support features like constexpr. No other
1770  // translation unit relies on the emission of the local vftable, translation
1771  // units are expected to generate them as needed.
1772  //
1773  // Because of this unique behavior, we maintain this logic here instead of
1774  // getVTableLinkage.
1775  llvm::GlobalValue::LinkageTypes VFTableLinkage =
1776  RD->hasAttr<DLLImportAttr>() ? llvm::GlobalValue::LinkOnceODRLinkage
1777  : CGM.getVTableLinkage(RD);
1778  bool VFTableComesFromAnotherTU =
1779  llvm::GlobalValue::isAvailableExternallyLinkage(VFTableLinkage) ||
1780  llvm::GlobalValue::isExternalLinkage(VFTableLinkage);
1781  bool VTableAliasIsRequred =
1782  !VFTableComesFromAnotherTU && getContext().getLangOpts().RTTIData;
1783 
1784  if (llvm::GlobalValue *VFTable =
1785  CGM.getModule().getNamedGlobal(VFTableName)) {
1786  VFTablesMap[ID] = VFTable;
1787  VTable = VTableAliasIsRequred
1788  ? cast<llvm::GlobalVariable>(
1789  cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
1790  : cast<llvm::GlobalVariable>(VFTable);
1791  return VTable;
1792  }
1793 
1794  const VTableLayout &VTLayout =
1795  VTContext.getVFTableLayout(RD, VFPtr->FullOffsetInMDC);
1796  llvm::GlobalValue::LinkageTypes VTableLinkage =
1797  VTableAliasIsRequred ? llvm::GlobalValue::PrivateLinkage : VFTableLinkage;
1798 
1799  StringRef VTableName = VTableAliasIsRequred ? StringRef() : VFTableName.str();
1800 
1801  llvm::Type *VTableType = CGM.getVTables().getVTableType(VTLayout);
1802 
1803  // Create a backing variable for the contents of VTable. The VTable may
1804  // or may not include space for a pointer to RTTI data.
1805  llvm::GlobalValue *VFTable;
1806  VTable = new llvm::GlobalVariable(CGM.getModule(), VTableType,
1807  /*isConstant=*/true, VTableLinkage,
1808  /*Initializer=*/nullptr, VTableName);
1809  VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1810 
1811  llvm::Comdat *C = nullptr;
1812  if (!VFTableComesFromAnotherTU &&
1813  (llvm::GlobalValue::isWeakForLinker(VFTableLinkage) ||
1814  (llvm::GlobalValue::isLocalLinkage(VFTableLinkage) &&
1815  VTableAliasIsRequred)))
1816  C = CGM.getModule().getOrInsertComdat(VFTableName.str());
1817 
1818  // Only insert a pointer into the VFTable for RTTI data if we are not
1819  // importing it. We never reference the RTTI data directly so there is no
1820  // need to make room for it.
1821  if (VTableAliasIsRequred) {
1822  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.Int32Ty, 0),
1823  llvm::ConstantInt::get(CGM.Int32Ty, 0),
1824  llvm::ConstantInt::get(CGM.Int32Ty, 1)};
1825  // Create a GEP which points just after the first entry in the VFTable,
1826  // this should be the location of the first virtual method.
1827  llvm::Constant *VTableGEP = llvm::ConstantExpr::getInBoundsGetElementPtr(
1828  VTable->getValueType(), VTable, GEPIndices);
1829  if (llvm::GlobalValue::isWeakForLinker(VFTableLinkage)) {
1830  VFTableLinkage = llvm::GlobalValue::ExternalLinkage;
1831  if (C)
1832  C->setSelectionKind(llvm::Comdat::Largest);
1833  }
1834  VFTable = llvm::GlobalAlias::create(CGM.Int8PtrTy,
1835  /*AddressSpace=*/0, VFTableLinkage,
1836  VFTableName.str(), VTableGEP,
1837  &CGM.getModule());
1838  VFTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1839  } else {
1840  // We don't need a GlobalAlias to be a symbol for the VTable if we won't
1841  // be referencing any RTTI data.
1842  // The GlobalVariable will end up being an appropriate definition of the
1843  // VFTable.
1844  VFTable = VTable;
1845  }
1846  if (C)
1847  VTable->setComdat(C);
1848 
1849  if (RD->hasAttr<DLLExportAttr>())
1850  VFTable->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1851 
1852  VFTablesMap[ID] = VFTable;
1853  return VTable;
1854 }
1855 
1856 CGCallee MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
1857  GlobalDecl GD,
1858  Address This,
1859  llvm::Type *Ty,
1860  SourceLocation Loc) {
1861  CGBuilderTy &Builder = CGF.Builder;
1862 
1863  Ty = Ty->getPointerTo()->getPointerTo();
1864  Address VPtr =
1865  adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1866 
1867  auto *MethodDecl = cast<CXXMethodDecl>(GD.getDecl());
1868  llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty, MethodDecl->getParent());
1869 
1870  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1871  MethodVFTableLocation ML = VFTContext.getMethodVFTableLocation(GD);
1872 
1873  // Compute the identity of the most derived class whose virtual table is
1874  // located at the MethodVFTableLocation ML.
1875  auto getObjectWithVPtr = [&] {
1876  return llvm::find_if(VFTContext.getVFPtrOffsets(
1877  ML.VBase ? ML.VBase : MethodDecl->getParent()),
1878  [&](const std::unique_ptr<VPtrInfo> &Info) {
1879  return Info->FullOffsetInMDC == ML.VFPtrOffset;
1880  })
1881  ->get()
1882  ->ObjectWithVPtr;
1883  };
1884 
1885  llvm::Value *VFunc;
1886  if (CGF.ShouldEmitVTableTypeCheckedLoad(MethodDecl->getParent())) {
1887  VFunc = CGF.EmitVTableTypeCheckedLoad(
1888  getObjectWithVPtr(), VTable,
1889  ML.Index * CGM.getContext().getTargetInfo().getPointerWidth(0) / 8);
1890  } else {
1891  if (CGM.getCodeGenOpts().PrepareForLTO)
1892  CGF.EmitTypeMetadataCodeForVCall(getObjectWithVPtr(), VTable, Loc);
1893 
1894  llvm::Value *VFuncPtr =
1895  Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
1896  VFunc = Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
1897  }
1898 
1899  CGCallee Callee(GD, VFunc);
1900  return Callee;
1901 }
1902 
1903 llvm::Value *MicrosoftCXXABI::EmitVirtualDestructorCall(
1904  CodeGenFunction &CGF, const CXXDestructorDecl *Dtor, CXXDtorType DtorType,
1905  Address This, DeleteOrMemberCallExpr E) {
1906  auto *CE = E.dyn_cast<const CXXMemberCallExpr *>();
1907  auto *D = E.dyn_cast<const CXXDeleteExpr *>();
1908  assert((CE != nullptr) ^ (D != nullptr));
1909  assert(CE == nullptr || CE->arg_begin() == CE->arg_end());
1910  assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
1911 
1912  // We have only one destructor in the vftable but can get both behaviors
1913  // by passing an implicit int parameter.
1914  GlobalDecl GD(Dtor, Dtor_Deleting);
1915  const CGFunctionInfo *FInfo =
1916  &CGM.getTypes().arrangeCXXStructorDeclaration(GD);
1917  llvm::FunctionType *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
1918  CGCallee Callee = CGCallee::forVirtual(CE, GD, This, Ty);
1919 
1920  ASTContext &Context = getContext();
1921  llvm::Value *ImplicitParam = llvm::ConstantInt::get(
1922  llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()),
1923  DtorType == Dtor_Deleting);
1924 
1925  QualType ThisTy;
1926  if (CE) {
1927  ThisTy = CE->getObjectType();
1928  } else {
1929  ThisTy = D->getDestroyedType();
1930  }
1931 
1932  This = adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1933  RValue RV = CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
1934  ImplicitParam, Context.IntTy, CE);
1935  return RV.getScalarVal();
1936 }
1937 
1938 const VBTableGlobals &
1939 MicrosoftCXXABI::enumerateVBTables(const CXXRecordDecl *RD) {
1940  // At this layer, we can key the cache off of a single class, which is much
1941  // easier than caching each vbtable individually.
1942  llvm::DenseMap<const CXXRecordDecl*, VBTableGlobals>::iterator Entry;
1943  bool Added;
1944  std::tie(Entry, Added) =
1945  VBTablesMap.insert(std::make_pair(RD, VBTableGlobals()));
1946  VBTableGlobals &VBGlobals = Entry->second;
1947  if (!Added)
1948  return VBGlobals;
1949 
1950  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
1951  VBGlobals.VBTables = &Context.enumerateVBTables(RD);
1952 
1953  // Cache the globals for all vbtables so we don't have to recompute the
1954  // mangled names.
1955  llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
1956  for (VPtrInfoVector::const_iterator I = VBGlobals.VBTables->begin(),
1957  E = VBGlobals.VBTables->end();
1958  I != E; ++I) {
1959  VBGlobals.Globals.push_back(getAddrOfVBTable(**I, RD, Linkage));
1960  }
1961 
1962  return VBGlobals;
1963 }
1964 
1965 llvm::Function *
1966 MicrosoftCXXABI::EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
1967  const MethodVFTableLocation &ML) {
1968  assert(!isa<CXXConstructorDecl>(MD) && !isa<CXXDestructorDecl>(MD) &&
1969  "can't form pointers to ctors or virtual dtors");
1970 
1971  // Calculate the mangled name.
1972  SmallString<256> ThunkName;
1973  llvm::raw_svector_ostream Out(ThunkName);
1974  getMangleContext().mangleVirtualMemPtrThunk(MD, ML, Out);
1975 
1976  // If the thunk has been generated previously, just return it.
1977  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
1978  return cast<llvm::Function>(GV);
1979 
1980  // Create the llvm::Function.
1981  const CGFunctionInfo &FnInfo =
1982  CGM.getTypes().arrangeUnprototypedMustTailThunk(MD);
1983  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
1984  llvm::Function *ThunkFn =
1986  ThunkName.str(), &CGM.getModule());
1987  assert(ThunkFn->getName() == ThunkName && "name was uniqued!");
1988 
1989  ThunkFn->setLinkage(MD->isExternallyVisible()
1990  ? llvm::GlobalValue::LinkOnceODRLinkage
1992  if (MD->isExternallyVisible())
1993  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
1994 
1995  CGM.SetLLVMFunctionAttributes(MD, FnInfo, ThunkFn);
1996  CGM.SetLLVMFunctionAttributesForDefinition(MD, ThunkFn);
1997 
1998  // Add the "thunk" attribute so that LLVM knows that the return type is
1999  // meaningless. These thunks can be used to call functions with differing
2000  // return types, and the caller is required to cast the prototype
2001  // appropriately to extract the correct value.
2002  ThunkFn->addFnAttr("thunk");
2003 
2004  // These thunks can be compared, so they are not unnamed.
2005  ThunkFn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
2006 
2007  // Start codegen.
2008  CodeGenFunction CGF(CGM);
2009  CGF.CurGD = GlobalDecl(MD);
2010  CGF.CurFuncIsThunk = true;
2011 
2012  // Build FunctionArgs, but only include the implicit 'this' parameter
2013  // declaration.
2014  FunctionArgList FunctionArgs;
2015  buildThisParam(CGF, FunctionArgs);
2016 
2017  // Start defining the function.
2018  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
2019  FunctionArgs, MD->getLocation(), SourceLocation());
2020  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
2021 
2022  // Load the vfptr and then callee from the vftable. The callee should have
2023  // adjusted 'this' so that the vfptr is at offset zero.
2024  llvm::Value *VTable = CGF.GetVTablePtr(
2025  getThisAddress(CGF), ThunkTy->getPointerTo()->getPointerTo(), MD->getParent());
2026 
2027  llvm::Value *VFuncPtr =
2028  CGF.Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
2029  llvm::Value *Callee =
2030  CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
2031 
2032  CGF.EmitMustTailThunk(MD, getThisValue(CGF), {ThunkTy, Callee});
2033 
2034  return ThunkFn;
2035 }
2036 
2037 void MicrosoftCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
2038  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
2039  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
2040  const std::unique_ptr<VPtrInfo>& VBT = (*VBGlobals.VBTables)[I];
2041  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
2042  if (GV->isDeclaration())
2043  emitVBTableDefinition(*VBT, RD, GV);
2044  }
2045 }
2046 
2047 llvm::GlobalVariable *
2048 MicrosoftCXXABI::getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
2049  llvm::GlobalVariable::LinkageTypes Linkage) {
2050  SmallString<256> OutName;
2051  llvm::raw_svector_ostream Out(OutName);
2052  getMangleContext().mangleCXXVBTable(RD, VBT.MangledPath, Out);
2053  StringRef Name = OutName.str();
2054 
2055  llvm::ArrayType *VBTableType =
2056  llvm::ArrayType::get(CGM.IntTy, 1 + VBT.ObjectWithVPtr->getNumVBases());
2057 
2058  assert(!CGM.getModule().getNamedGlobal(Name) &&
2059  "vbtable with this name already exists: mangling bug?");
2060  CharUnits Alignment =
2061  CGM.getContext().getTypeAlignInChars(CGM.getContext().IntTy);
2062  llvm::GlobalVariable *GV = CGM.CreateOrReplaceCXXRuntimeVariable(
2063  Name, VBTableType, Linkage, Alignment.getQuantity());
2064  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2065 
2066  if (RD->hasAttr<DLLImportAttr>())
2067  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2068  else if (RD->hasAttr<DLLExportAttr>())
2069  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2070 
2071  if (!GV->hasExternalLinkage())
2072  emitVBTableDefinition(VBT, RD, GV);
2073 
2074  return GV;
2075 }
2076 
2077 void MicrosoftCXXABI::emitVBTableDefinition(const VPtrInfo &VBT,
2078  const CXXRecordDecl *RD,
2079  llvm::GlobalVariable *GV) const {
2080  const CXXRecordDecl *ObjectWithVPtr = VBT.ObjectWithVPtr;
2081 
2082  assert(RD->getNumVBases() && ObjectWithVPtr->getNumVBases() &&
2083  "should only emit vbtables for classes with vbtables");
2084 
2085  const ASTRecordLayout &BaseLayout =
2086  getContext().getASTRecordLayout(VBT.IntroducingObject);
2087  const ASTRecordLayout &DerivedLayout = getContext().getASTRecordLayout(RD);
2088 
2089  SmallVector<llvm::Constant *, 4> Offsets(1 + ObjectWithVPtr->getNumVBases(),
2090  nullptr);
2091 
2092  // The offset from ObjectWithVPtr's vbptr to itself always leads.
2093  CharUnits VBPtrOffset = BaseLayout.getVBPtrOffset();
2094  Offsets[0] = llvm::ConstantInt::get(CGM.IntTy, -VBPtrOffset.getQuantity());
2095 
2096  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
2097  for (const auto &I : ObjectWithVPtr->vbases()) {
2098  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
2099  CharUnits Offset = DerivedLayout.getVBaseClassOffset(VBase);
2100  assert(!Offset.isNegative());
2101 
2102  // Make it relative to the subobject vbptr.
2103  CharUnits CompleteVBPtrOffset = VBT.NonVirtualOffset + VBPtrOffset;
2104  if (VBT.getVBaseWithVPtr())
2105  CompleteVBPtrOffset +=
2106  DerivedLayout.getVBaseClassOffset(VBT.getVBaseWithVPtr());
2107  Offset -= CompleteVBPtrOffset;
2108 
2109  unsigned VBIndex = Context.getVBTableIndex(ObjectWithVPtr, VBase);
2110  assert(Offsets[VBIndex] == nullptr && "The same vbindex seen twice?");
2111  Offsets[VBIndex] = llvm::ConstantInt::get(CGM.IntTy, Offset.getQuantity());
2112  }
2113 
2114  assert(Offsets.size() ==
2115  cast<llvm::ArrayType>(cast<llvm::PointerType>(GV->getType())
2116  ->getElementType())->getNumElements());
2117  llvm::ArrayType *VBTableType =
2118  llvm::ArrayType::get(CGM.IntTy, Offsets.size());
2119  llvm::Constant *Init = llvm::ConstantArray::get(VBTableType, Offsets);
2120  GV->setInitializer(Init);
2121 
2122  if (RD->hasAttr<DLLImportAttr>())
2123  GV->setLinkage(llvm::GlobalVariable::AvailableExternallyLinkage);
2124 }
2125 
2126 llvm::Value *MicrosoftCXXABI::performThisAdjustment(CodeGenFunction &CGF,
2127  Address This,
2128  const ThisAdjustment &TA) {
2129  if (TA.isEmpty())
2130  return This.getPointer();
2131 
2132  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
2133 
2134  llvm::Value *V;
2135  if (TA.Virtual.isEmpty()) {
2136  V = This.getPointer();
2137  } else {
2138  assert(TA.Virtual.Microsoft.VtordispOffset < 0);
2139  // Adjust the this argument based on the vtordisp value.
2140  Address VtorDispPtr =
2143  VtorDispPtr = CGF.Builder.CreateElementBitCast(VtorDispPtr, CGF.Int32Ty);
2144  llvm::Value *VtorDisp = CGF.Builder.CreateLoad(VtorDispPtr, "vtordisp");
2145  V = CGF.Builder.CreateGEP(This.getPointer(),
2146  CGF.Builder.CreateNeg(VtorDisp));
2147 
2148  // Unfortunately, having applied the vtordisp means that we no
2149  // longer really have a known alignment for the vbptr step.
2150  // We'll assume the vbptr is pointer-aligned.
2151 
2152  if (TA.Virtual.Microsoft.VBPtrOffset) {
2153  // If the final overrider is defined in a virtual base other than the one
2154  // that holds the vfptr, we have to use a vtordispex thunk which looks up
2155  // the vbtable of the derived class.
2156  assert(TA.Virtual.Microsoft.VBPtrOffset > 0);
2157  assert(TA.Virtual.Microsoft.VBOffsetOffset >= 0);
2158  llvm::Value *VBPtr;
2159  llvm::Value *VBaseOffset =
2160  GetVBaseOffsetFromVBPtr(CGF, Address(V, CGF.getPointerAlign()),
2162  TA.Virtual.Microsoft.VBOffsetOffset, &VBPtr);
2163  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2164  }
2165  }
2166 
2167  if (TA.NonVirtual) {
2168  // Non-virtual adjustment might result in a pointer outside the allocated
2169  // object, e.g. if the final overrider class is laid out after the virtual
2170  // base that declares a method in the most derived class.
2171  V = CGF.Builder.CreateConstGEP1_32(V, TA.NonVirtual);
2172  }
2173 
2174  // Don't need to bitcast back, the call CodeGen will handle this.
2175  return V;
2176 }
2177 
2178 llvm::Value *
2179 MicrosoftCXXABI::performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
2180  const ReturnAdjustment &RA) {
2181  if (RA.isEmpty())
2182  return Ret.getPointer();
2183 
2184  auto OrigTy = Ret.getType();
2185  Ret = CGF.Builder.CreateElementBitCast(Ret, CGF.Int8Ty);
2186 
2187  llvm::Value *V = Ret.getPointer();
2188  if (RA.Virtual.Microsoft.VBIndex) {
2189  assert(RA.Virtual.Microsoft.VBIndex > 0);
2190  int32_t IntSize = CGF.getIntSize().getQuantity();
2191  llvm::Value *VBPtr;
2192  llvm::Value *VBaseOffset =
2193  GetVBaseOffsetFromVBPtr(CGF, Ret, RA.Virtual.Microsoft.VBPtrOffset,
2194  IntSize * RA.Virtual.Microsoft.VBIndex, &VBPtr);
2195  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2196  }
2197 
2198  if (RA.NonVirtual)
2199  V = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, V, RA.NonVirtual);
2200 
2201  // Cast back to the original type.
2202  return CGF.Builder.CreateBitCast(V, OrigTy);
2203 }
2204 
2205 bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
2206  QualType elementType) {
2207  // Microsoft seems to completely ignore the possibility of a
2208  // two-argument usual deallocation function.
2209  return elementType.isDestructedType();
2210 }
2211 
2212 bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) {
2213  // Microsoft seems to completely ignore the possibility of a
2214  // two-argument usual deallocation function.
2215  return expr->getAllocatedType().isDestructedType();
2216 }
2217 
2218 CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) {
2219  // The array cookie is always a size_t; we then pad that out to the
2220  // alignment of the element type.
2221  ASTContext &Ctx = getContext();
2222  return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
2223  Ctx.getTypeAlignInChars(type));
2224 }
2225 
2226 llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
2227  Address allocPtr,
2228  CharUnits cookieSize) {
2229  Address numElementsPtr =
2230  CGF.Builder.CreateElementBitCast(allocPtr, CGF.SizeTy);
2231  return CGF.Builder.CreateLoad(numElementsPtr);
2232 }
2233 
2234 Address MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
2235  Address newPtr,
2236  llvm::Value *numElements,
2237  const CXXNewExpr *expr,
2238  QualType elementType) {
2239  assert(requiresArrayCookie(expr));
2240 
2241  // The size of the cookie.
2242  CharUnits cookieSize = getArrayCookieSizeImpl(elementType);
2243 
2244  // Compute an offset to the cookie.
2245  Address cookiePtr = newPtr;
2246 
2247  // Write the number of elements into the appropriate slot.
2248  Address numElementsPtr
2249  = CGF.Builder.CreateElementBitCast(cookiePtr, CGF.SizeTy);
2250  CGF.Builder.CreateStore(numElements, numElementsPtr);
2251 
2252  // Finally, compute a pointer to the actual data buffer by skipping
2253  // over the cookie completely.
2254  return CGF.Builder.CreateConstInBoundsByteGEP(newPtr, cookieSize);
2255 }
2256 
2258  llvm::FunctionCallee Dtor,
2259  llvm::Constant *Addr) {
2260  // Create a function which calls the destructor.
2261  llvm::Constant *DtorStub = CGF.createAtExitStub(VD, Dtor, Addr);
2262 
2263  // extern "C" int __tlregdtor(void (*f)(void));
2264  llvm::FunctionType *TLRegDtorTy = llvm::FunctionType::get(
2265  CGF.IntTy, DtorStub->getType(), /*isVarArg=*/false);
2266 
2267  llvm::FunctionCallee TLRegDtor = CGF.CGM.CreateRuntimeFunction(
2268  TLRegDtorTy, "__tlregdtor", llvm::AttributeList(), /*Local=*/true);
2269  if (llvm::Function *TLRegDtorFn =
2270  dyn_cast<llvm::Function>(TLRegDtor.getCallee()))
2271  TLRegDtorFn->setDoesNotThrow();
2272 
2273  CGF.EmitNounwindRuntimeCall(TLRegDtor, DtorStub);
2274 }
2275 
2276 void MicrosoftCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
2277  llvm::FunctionCallee Dtor,
2278  llvm::Constant *Addr) {
2279  if (D.isNoDestroy(CGM.getContext()))
2280  return;
2281 
2282  if (D.getTLSKind())
2283  return emitGlobalDtorWithTLRegDtor(CGF, D, Dtor, Addr);
2284 
2285  // The default behavior is to use atexit.
2286  CGF.registerGlobalDtorWithAtExit(D, Dtor, Addr);
2287 }
2288 
2289 void MicrosoftCXXABI::EmitThreadLocalInitFuncs(
2290  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
2291  ArrayRef<llvm::Function *> CXXThreadLocalInits,
2292  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) {
2293  if (CXXThreadLocalInits.empty())
2294  return;
2295 
2296  CGM.AppendLinkerOptions(CGM.getTarget().getTriple().getArch() ==
2297  llvm::Triple::x86
2298  ? "/include:___dyn_tls_init@12"
2299  : "/include:__dyn_tls_init");
2300 
2301  // This will create a GV in the .CRT$XDU section. It will point to our
2302  // initialization function. The CRT will call all of these function
2303  // pointers at start-up time and, eventually, at thread-creation time.
2304  auto AddToXDU = [&CGM](llvm::Function *InitFunc) {
2305  llvm::GlobalVariable *InitFuncPtr = new llvm::GlobalVariable(
2306  CGM.getModule(), InitFunc->getType(), /*isConstant=*/true,
2308  Twine(InitFunc->getName(), "$initializer$"));
2309  InitFuncPtr->setSection(".CRT$XDU");
2310  // This variable has discardable linkage, we have to add it to @llvm.used to
2311  // ensure it won't get discarded.
2312  CGM.addUsedGlobal(InitFuncPtr);
2313  return InitFuncPtr;
2314  };
2315 
2316  std::vector<llvm::Function *> NonComdatInits;
2317  for (size_t I = 0, E = CXXThreadLocalInitVars.size(); I != E; ++I) {
2318  llvm::GlobalVariable *GV = cast<llvm::GlobalVariable>(
2319  CGM.GetGlobalValue(CGM.getMangledName(CXXThreadLocalInitVars[I])));
2320  llvm::Function *F = CXXThreadLocalInits[I];
2321 
2322  // If the GV is already in a comdat group, then we have to join it.
2323  if (llvm::Comdat *C = GV->getComdat())
2324  AddToXDU(F)->setComdat(C);
2325  else
2326  NonComdatInits.push_back(F);
2327  }
2328 
2329  if (!NonComdatInits.empty()) {
2330  llvm::FunctionType *FTy =
2331  llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
2332  llvm::Function *InitFunc = CGM.CreateGlobalInitOrDestructFunction(
2333  FTy, "__tls_init", CGM.getTypes().arrangeNullaryFunction(),
2334  SourceLocation(), /*TLS=*/true);
2335  CodeGenFunction(CGM).GenerateCXXGlobalInitFunc(InitFunc, NonComdatInits);
2336 
2337  AddToXDU(InitFunc);
2338  }
2339 }
2340 
2341 LValue MicrosoftCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
2342  const VarDecl *VD,
2343  QualType LValType) {
2344  CGF.CGM.ErrorUnsupported(VD, "thread wrappers");
2345  return LValue();
2346 }
2347 
2349  StringRef VarName("_Init_thread_epoch");
2350  CharUnits Align = CGM.getIntAlign();
2351  if (auto *GV = CGM.getModule().getNamedGlobal(VarName))
2352  return ConstantAddress(GV, Align);
2353  auto *GV = new llvm::GlobalVariable(
2354  CGM.getModule(), CGM.IntTy,
2355  /*isConstant=*/false, llvm::GlobalVariable::ExternalLinkage,
2356  /*Initializer=*/nullptr, VarName,
2357  /*InsertBefore=*/nullptr, llvm::GlobalVariable::GeneralDynamicTLSModel);
2358  GV->setAlignment(Align.getAsAlign());
2359  return ConstantAddress(GV, Align);
2360 }
2361 
2362 static llvm::FunctionCallee getInitThreadHeaderFn(CodeGenModule &CGM) {
2363  llvm::FunctionType *FTy =
2364  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2365  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2366  return CGM.CreateRuntimeFunction(
2367  FTy, "_Init_thread_header",
2368  llvm::AttributeList::get(CGM.getLLVMContext(),
2369  llvm::AttributeList::FunctionIndex,
2370  llvm::Attribute::NoUnwind),
2371  /*Local=*/true);
2372 }
2373 
2374 static llvm::FunctionCallee getInitThreadFooterFn(CodeGenModule &CGM) {
2375  llvm::FunctionType *FTy =
2376  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2377  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2378  return CGM.CreateRuntimeFunction(
2379  FTy, "_Init_thread_footer",
2380  llvm::AttributeList::get(CGM.getLLVMContext(),
2381  llvm::AttributeList::FunctionIndex,
2382  llvm::Attribute::NoUnwind),
2383  /*Local=*/true);
2384 }
2385 
2386 static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM) {
2387  llvm::FunctionType *FTy =
2388  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2389  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2390  return CGM.CreateRuntimeFunction(
2391  FTy, "_Init_thread_abort",
2392  llvm::AttributeList::get(CGM.getLLVMContext(),
2393  llvm::AttributeList::FunctionIndex,
2394  llvm::Attribute::NoUnwind),
2395  /*Local=*/true);
2396 }
2397 
2398 namespace {
2399 struct ResetGuardBit final : EHScopeStack::Cleanup {
2400  Address Guard;
2401  unsigned GuardNum;
2402  ResetGuardBit(Address Guard, unsigned GuardNum)
2403  : Guard(Guard), GuardNum(GuardNum) {}
2404 
2405  void Emit(CodeGenFunction &CGF, Flags flags) override {
2406  // Reset the bit in the mask so that the static variable may be
2407  // reinitialized.
2408  CGBuilderTy &Builder = CGF.Builder;
2409  llvm::LoadInst *LI = Builder.CreateLoad(Guard);
2410  llvm::ConstantInt *Mask =
2411  llvm::ConstantInt::get(CGF.IntTy, ~(1ULL << GuardNum));
2412  Builder.CreateStore(Builder.CreateAnd(LI, Mask), Guard);
2413  }
2414 };
2415 
2416 struct CallInitThreadAbort final : EHScopeStack::Cleanup {
2417  llvm::Value *Guard;
2418  CallInitThreadAbort(Address Guard) : Guard(Guard.getPointer()) {}
2419 
2420  void Emit(CodeGenFunction &CGF, Flags flags) override {
2421  // Calling _Init_thread_abort will reset the guard's state.
2423  }
2424 };
2425 }
2426 
2427 void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
2428  llvm::GlobalVariable *GV,
2429  bool PerformInit) {
2430  // MSVC only uses guards for static locals.
2431  if (!D.isStaticLocal()) {
2432  assert(GV->hasWeakLinkage() || GV->hasLinkOnceLinkage());
2433  // GlobalOpt is allowed to discard the initializer, so use linkonce_odr.
2434  llvm::Function *F = CGF.CurFn;
2435  F->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
2436  F->setComdat(CGM.getModule().getOrInsertComdat(F->getName()));
2437  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2438  return;
2439  }
2440 
2441  bool ThreadlocalStatic = D.getTLSKind();
2442  bool ThreadsafeStatic = getContext().getLangOpts().ThreadsafeStatics;
2443 
2444  // Thread-safe static variables which aren't thread-specific have a
2445  // per-variable guard.
2446  bool HasPerVariableGuard = ThreadsafeStatic && !ThreadlocalStatic;
2447 
2448  CGBuilderTy &Builder = CGF.Builder;
2449  llvm::IntegerType *GuardTy = CGF.Int32Ty;
2450  llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0);
2451  CharUnits GuardAlign = CharUnits::fromQuantity(4);
2452 
2453  // Get the guard variable for this function if we have one already.
2454  GuardInfo *GI = nullptr;
2455  if (ThreadlocalStatic)
2456  GI = &ThreadLocalGuardVariableMap[D.getDeclContext()];
2457  else if (!ThreadsafeStatic)
2458  GI = &GuardVariableMap[D.getDeclContext()];
2459 
2460  llvm::GlobalVariable *GuardVar = GI ? GI->Guard : nullptr;
2461  unsigned GuardNum;
2462  if (D.isExternallyVisible()) {
2463  // Externally visible variables have to be numbered in Sema to properly
2464  // handle unreachable VarDecls.
2465  GuardNum = getContext().getStaticLocalNumber(&D);
2466  assert(GuardNum > 0);
2467  GuardNum--;
2468  } else if (HasPerVariableGuard) {
2469  GuardNum = ThreadSafeGuardNumMap[D.getDeclContext()]++;
2470  } else {
2471  // Non-externally visible variables are numbered here in CodeGen.
2472  GuardNum = GI->BitIndex++;
2473  }
2474 
2475  if (!HasPerVariableGuard && GuardNum >= 32) {
2476  if (D.isExternallyVisible())
2477  ErrorUnsupportedABI(CGF, "more than 32 guarded initializations");
2478  GuardNum %= 32;
2479  GuardVar = nullptr;
2480  }
2481 
2482  if (!GuardVar) {
2483  // Mangle the name for the guard.
2484  SmallString<256> GuardName;
2485  {
2486  llvm::raw_svector_ostream Out(GuardName);
2487  if (HasPerVariableGuard)
2488  getMangleContext().mangleThreadSafeStaticGuardVariable(&D, GuardNum,
2489  Out);
2490  else
2491  getMangleContext().mangleStaticGuardVariable(&D, Out);
2492  }
2493 
2494  // Create the guard variable with a zero-initializer. Just absorb linkage,
2495  // visibility and dll storage class from the guarded variable.
2496  GuardVar =
2497  new llvm::GlobalVariable(CGM.getModule(), GuardTy, /*isConstant=*/false,
2498  GV->getLinkage(), Zero, GuardName.str());
2499  GuardVar->setVisibility(GV->getVisibility());
2500  GuardVar->setDLLStorageClass(GV->getDLLStorageClass());
2501  GuardVar->setAlignment(GuardAlign.getAsAlign());
2502  if (GuardVar->isWeakForLinker())
2503  GuardVar->setComdat(
2504  CGM.getModule().getOrInsertComdat(GuardVar->getName()));
2505  if (D.getTLSKind())
2506  GuardVar->setThreadLocal(true);
2507  if (GI && !HasPerVariableGuard)
2508  GI->Guard = GuardVar;
2509  }
2510 
2511  ConstantAddress GuardAddr(GuardVar, GuardAlign);
2512 
2513  assert(GuardVar->getLinkage() == GV->getLinkage() &&
2514  "static local from the same function had different linkage");
2515 
2516  if (!HasPerVariableGuard) {
2517  // Pseudo code for the test:
2518  // if (!(GuardVar & MyGuardBit)) {
2519  // GuardVar |= MyGuardBit;
2520  // ... initialize the object ...;
2521  // }
2522 
2523  // Test our bit from the guard variable.
2524  llvm::ConstantInt *Bit = llvm::ConstantInt::get(GuardTy, 1ULL << GuardNum);
2525  llvm::LoadInst *LI = Builder.CreateLoad(GuardAddr);
2526  llvm::Value *NeedsInit =
2527  Builder.CreateICmpEQ(Builder.CreateAnd(LI, Bit), Zero);
2528  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2529  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2530  CGF.EmitCXXGuardedInitBranch(NeedsInit, InitBlock, EndBlock,
2532 
2533  // Set our bit in the guard variable and emit the initializer and add a global
2534  // destructor if appropriate.
2535  CGF.EmitBlock(InitBlock);
2536  Builder.CreateStore(Builder.CreateOr(LI, Bit), GuardAddr);
2537  CGF.EHStack.pushCleanup<ResetGuardBit>(EHCleanup, GuardAddr, GuardNum);
2538  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2539  CGF.PopCleanupBlock();
2540  Builder.CreateBr(EndBlock);
2541 
2542  // Continue.
2543  CGF.EmitBlock(EndBlock);
2544  } else {
2545  // Pseudo code for the test:
2546  // if (TSS > _Init_thread_epoch) {
2547  // _Init_thread_header(&TSS);
2548  // if (TSS == -1) {
2549  // ... initialize the object ...;
2550  // _Init_thread_footer(&TSS);
2551  // }
2552  // }
2553  //
2554  // The algorithm is almost identical to what can be found in the appendix
2555  // found in N2325.
2556 
2557  // This BasicBLock determines whether or not we have any work to do.
2558  llvm::LoadInst *FirstGuardLoad = Builder.CreateLoad(GuardAddr);
2559  FirstGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2560  llvm::LoadInst *InitThreadEpoch =
2561  Builder.CreateLoad(getInitThreadEpochPtr(CGM));
2562  llvm::Value *IsUninitialized =
2563  Builder.CreateICmpSGT(FirstGuardLoad, InitThreadEpoch);
2564  llvm::BasicBlock *AttemptInitBlock = CGF.createBasicBlock("init.attempt");
2565  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2566  CGF.EmitCXXGuardedInitBranch(IsUninitialized, AttemptInitBlock, EndBlock,
2568 
2569  // This BasicBlock attempts to determine whether or not this thread is
2570  // responsible for doing the initialization.
2571  CGF.EmitBlock(AttemptInitBlock);
2573  GuardAddr.getPointer());
2574  llvm::LoadInst *SecondGuardLoad = Builder.CreateLoad(GuardAddr);
2575  SecondGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2576  llvm::Value *ShouldDoInit =
2577  Builder.CreateICmpEQ(SecondGuardLoad, getAllOnesInt());
2578  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2579  Builder.CreateCondBr(ShouldDoInit, InitBlock, EndBlock);
2580 
2581  // Ok, we ended up getting selected as the initializing thread.
2582  CGF.EmitBlock(InitBlock);
2583  CGF.EHStack.pushCleanup<CallInitThreadAbort>(EHCleanup, GuardAddr);
2584  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2585  CGF.PopCleanupBlock();
2587  GuardAddr.getPointer());
2588  Builder.CreateBr(EndBlock);
2589 
2590  CGF.EmitBlock(EndBlock);
2591  }
2592 }
2593 
2594 bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
2595  // Null-ness for function memptrs only depends on the first field, which is
2596  // the function pointer. The rest don't matter, so we can zero initialize.
2597  if (MPT->isMemberFunctionPointer())
2598  return true;
2599 
2600  // The virtual base adjustment field is always -1 for null, so if we have one
2601  // we can't zero initialize. The field offset is sometimes also -1 if 0 is a
2602  // valid field offset.
2603  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2604  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2605  return (!MSInheritanceAttr::hasVBTableOffsetField(Inheritance) &&
2606  RD->nullFieldOffsetIsZero());
2607 }
2608 
2609 llvm::Type *
2610 MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
2611  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2612  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2614  if (MPT->isMemberFunctionPointer())
2615  fields.push_back(CGM.VoidPtrTy); // FunctionPointerOrVirtualThunk
2616  else
2617  fields.push_back(CGM.IntTy); // FieldOffset
2618 
2619  if (MSInheritanceAttr::hasNVOffsetField(MPT->isMemberFunctionPointer(),
2620  Inheritance))
2621  fields.push_back(CGM.IntTy);
2622  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
2623  fields.push_back(CGM.IntTy);
2624  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2625  fields.push_back(CGM.IntTy); // VirtualBaseAdjustmentOffset
2626 
2627  if (fields.size() == 1)
2628  return fields[0];
2629  return llvm::StructType::get(CGM.getLLVMContext(), fields);
2630 }
2631 
2632 void MicrosoftCXXABI::
2633 GetNullMemberPointerFields(const MemberPointerType *MPT,
2635  assert(fields.empty());
2636  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2637  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2638  if (MPT->isMemberFunctionPointer()) {
2639  // FunctionPointerOrVirtualThunk
2640  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2641  } else {
2642  if (RD->nullFieldOffsetIsZero())
2643  fields.push_back(getZeroInt()); // FieldOffset
2644  else
2645  fields.push_back(getAllOnesInt()); // FieldOffset
2646  }
2647 
2648  if (MSInheritanceAttr::hasNVOffsetField(MPT->isMemberFunctionPointer(),
2649  Inheritance))
2650  fields.push_back(getZeroInt());
2651  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
2652  fields.push_back(getZeroInt());
2653  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2654  fields.push_back(getAllOnesInt());
2655 }
2656 
2657 llvm::Constant *
2658 MicrosoftCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
2660  GetNullMemberPointerFields(MPT, fields);
2661  if (fields.size() == 1)
2662  return fields[0];
2663  llvm::Constant *Res = llvm::ConstantStruct::getAnon(fields);
2664  assert(Res->getType() == ConvertMemberPointerType(MPT));
2665  return Res;
2666 }
2667 
2668 llvm::Constant *
2669 MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
2670  bool IsMemberFunction,
2671  const CXXRecordDecl *RD,
2672  CharUnits NonVirtualBaseAdjustment,
2673  unsigned VBTableIndex) {
2674  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2675 
2676  // Single inheritance class member pointer are represented as scalars instead
2677  // of aggregates.
2678  if (MSInheritanceAttr::hasOnlyOneField(IsMemberFunction, Inheritance))
2679  return FirstField;
2680 
2682  fields.push_back(FirstField);
2683 
2684  if (MSInheritanceAttr::hasNVOffsetField(IsMemberFunction, Inheritance))
2685  fields.push_back(llvm::ConstantInt::get(
2686  CGM.IntTy, NonVirtualBaseAdjustment.getQuantity()));
2687 
2688  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance)) {
2689  CharUnits Offs = CharUnits::Zero();
2690  if (VBTableIndex)
2691  Offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
2692  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, Offs.getQuantity()));
2693  }
2694 
2695  // The rest of the fields are adjusted by conversions to a more derived class.
2696  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2697  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBTableIndex));
2698 
2699  return llvm::ConstantStruct::getAnon(fields);
2700 }
2701 
2702 llvm::Constant *
2703 MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
2704  CharUnits offset) {
2705  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2706  if (RD->getMSInheritanceModel() ==
2707  MSInheritanceAttr::Keyword_virtual_inheritance)
2708  offset -= getContext().getOffsetOfBaseWithVBPtr(RD);
2709  llvm::Constant *FirstField =
2710  llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity());
2711  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD,
2712  CharUnits::Zero(), /*VBTableIndex=*/0);
2713 }
2714 
2715 llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP,
2716  QualType MPType) {
2717  const MemberPointerType *DstTy = MPType->castAs<MemberPointerType>();
2718  const ValueDecl *MPD = MP.getMemberPointerDecl();
2719  if (!MPD)
2720  return EmitNullMemberPointer(DstTy);
2721 
2722  ASTContext &Ctx = getContext();
2723  ArrayRef<const CXXRecordDecl *> MemberPointerPath = MP.getMemberPointerPath();
2724 
2725  llvm::Constant *C;
2726  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) {
2727  C = EmitMemberFunctionPointer(MD);
2728  } else {
2729  CharUnits FieldOffset = Ctx.toCharUnitsFromBits(Ctx.getFieldOffset(MPD));
2730  C = EmitMemberDataPointer(DstTy, FieldOffset);
2731  }
2732 
2733  if (!MemberPointerPath.empty()) {
2734  const CXXRecordDecl *SrcRD = cast<CXXRecordDecl>(MPD->getDeclContext());
2735  const Type *SrcRecTy = Ctx.getTypeDeclType(SrcRD).getTypePtr();
2736  const MemberPointerType *SrcTy =
2737  Ctx.getMemberPointerType(DstTy->getPointeeType(), SrcRecTy)
2738  ->castAs<MemberPointerType>();
2739 
2740  bool DerivedMember = MP.isMemberPointerToDerivedMember();
2741  SmallVector<const CXXBaseSpecifier *, 4> DerivedToBasePath;
2742  const CXXRecordDecl *PrevRD = SrcRD;
2743  for (const CXXRecordDecl *PathElem : MemberPointerPath) {
2744  const CXXRecordDecl *Base = nullptr;
2745  const CXXRecordDecl *Derived = nullptr;
2746  if (DerivedMember) {
2747  Base = PathElem;
2748  Derived = PrevRD;
2749  } else {
2750  Base = PrevRD;
2751  Derived = PathElem;
2752  }
2753  for (const CXXBaseSpecifier &BS : Derived->bases())
2754  if (BS.getType()->getAsCXXRecordDecl()->getCanonicalDecl() ==
2755  Base->getCanonicalDecl())
2756  DerivedToBasePath.push_back(&BS);
2757  PrevRD = PathElem;
2758  }
2759  assert(DerivedToBasePath.size() == MemberPointerPath.size());
2760 
2761  CastKind CK = DerivedMember ? CK_DerivedToBaseMemberPointer
2762  : CK_BaseToDerivedMemberPointer;
2763  C = EmitMemberPointerConversion(SrcTy, DstTy, CK, DerivedToBasePath.begin(),
2764  DerivedToBasePath.end(), C);
2765  }
2766  return C;
2767 }
2768 
2769 llvm::Constant *
2770 MicrosoftCXXABI::EmitMemberFunctionPointer(const CXXMethodDecl *MD) {
2771  assert(MD->isInstance() && "Member function must not be static!");
2772 
2773  CharUnits NonVirtualBaseAdjustment = CharUnits::Zero();
2775  CodeGenTypes &Types = CGM.getTypes();
2776 
2777  unsigned VBTableIndex = 0;
2778  llvm::Constant *FirstField;
2779  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
2780  if (!MD->isVirtual()) {
2781  llvm::Type *Ty;
2782  // Check whether the function has a computable LLVM signature.
2783  if (Types.isFuncTypeConvertible(FPT)) {
2784  // The function has a computable LLVM signature; use the correct type.
2785  Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD));
2786  } else {
2787  // Use an arbitrary non-function type to tell GetAddrOfFunction that the
2788  // function type is incomplete.
2789  Ty = CGM.PtrDiffTy;
2790  }
2791  FirstField = CGM.GetAddrOfFunction(MD, Ty);
2792  } else {
2793  auto &VTableContext = CGM.getMicrosoftVTableContext();
2794  MethodVFTableLocation ML = VTableContext.getMethodVFTableLocation(MD);
2795  FirstField = EmitVirtualMemPtrThunk(MD, ML);
2796  // Include the vfptr adjustment if the method is in a non-primary vftable.
2797  NonVirtualBaseAdjustment += ML.VFPtrOffset;
2798  if (ML.VBase)
2799  VBTableIndex = VTableContext.getVBTableIndex(RD, ML.VBase) * 4;
2800  }
2801 
2802  if (VBTableIndex == 0 &&
2803  RD->getMSInheritanceModel() ==
2804  MSInheritanceAttr::Keyword_virtual_inheritance)
2805  NonVirtualBaseAdjustment -= getContext().getOffsetOfBaseWithVBPtr(RD);
2806 
2807  // The rest of the fields are common with data member pointers.
2808  FirstField = llvm::ConstantExpr::getBitCast(FirstField, CGM.VoidPtrTy);
2809  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD,
2810  NonVirtualBaseAdjustment, VBTableIndex);
2811 }
2812 
2813 /// Member pointers are the same if they're either bitwise identical *or* both
2814 /// null. Null-ness for function members is determined by the first field,
2815 /// while for data member pointers we must compare all fields.
2816 llvm::Value *
2817 MicrosoftCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
2818  llvm::Value *L,
2819  llvm::Value *R,
2820  const MemberPointerType *MPT,
2821  bool Inequality) {
2822  CGBuilderTy &Builder = CGF.Builder;
2823 
2824  // Handle != comparisons by switching the sense of all boolean operations.
2825  llvm::ICmpInst::Predicate Eq;
2826  llvm::Instruction::BinaryOps And, Or;
2827  if (Inequality) {
2828  Eq = llvm::ICmpInst::ICMP_NE;
2829  And = llvm::Instruction::Or;
2831  } else {
2832  Eq = llvm::ICmpInst::ICMP_EQ;
2833  And = llvm::Instruction::And;
2834  Or = llvm::Instruction::Or;
2835  }
2836 
2837  // If this is a single field member pointer (single inheritance), this is a
2838  // single icmp.
2839  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2840  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2841  if (MSInheritanceAttr::hasOnlyOneField(MPT->isMemberFunctionPointer(),
2842  Inheritance))
2843  return Builder.CreateICmp(Eq, L, R);
2844 
2845  // Compare the first field.
2846  llvm::Value *L0 = Builder.CreateExtractValue(L, 0, "lhs.0");
2847  llvm::Value *R0 = Builder.CreateExtractValue(R, 0, "rhs.0");
2848  llvm::Value *Cmp0 = Builder.CreateICmp(Eq, L0, R0, "memptr.cmp.first");
2849 
2850  // Compare everything other than the first field.
2851  llvm::Value *Res = nullptr;
2852  llvm::StructType *LType = cast<llvm::StructType>(L->getType());
2853  for (unsigned I = 1, E = LType->getNumElements(); I != E; ++I) {
2854  llvm::Value *LF = Builder.CreateExtractValue(L, I);
2855  llvm::Value *RF = Builder.CreateExtractValue(R, I);
2856  llvm::Value *Cmp = Builder.CreateICmp(Eq, LF, RF, "memptr.cmp.rest");
2857  if (Res)
2858  Res = Builder.CreateBinOp(And, Res, Cmp);
2859  else
2860  Res = Cmp;
2861  }
2862 
2863  // Check if the first field is 0 if this is a function pointer.
2864  if (MPT->isMemberFunctionPointer()) {
2865  // (l1 == r1 && ...) || l0 == 0
2866  llvm::Value *Zero = llvm::Constant::getNullValue(L0->getType());
2867  llvm::Value *IsZero = Builder.CreateICmp(Eq, L0, Zero, "memptr.cmp.iszero");
2868  Res = Builder.CreateBinOp(Or, Res, IsZero);
2869  }
2870 
2871  // Combine the comparison of the first field, which must always be true for
2872  // this comparison to succeeed.
2873  return Builder.CreateBinOp(And, Res, Cmp0, "memptr.cmp");
2874 }
2875 
2876 llvm::Value *
2877 MicrosoftCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
2878  llvm::Value *MemPtr,
2879  const MemberPointerType *MPT) {
2880  CGBuilderTy &Builder = CGF.Builder;
2882  // We only need one field for member functions.
2883  if (MPT->isMemberFunctionPointer())
2884  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2885  else
2886  GetNullMemberPointerFields(MPT, fields);
2887  assert(!fields.empty());
2888  llvm::Value *FirstField = MemPtr;
2889  if (MemPtr->getType()->isStructTy())
2890  FirstField = Builder.CreateExtractValue(MemPtr, 0);
2891  llvm::Value *Res = Builder.CreateICmpNE(FirstField, fields[0], "memptr.cmp0");
2892 
2893  // For function member pointers, we only need to test the function pointer
2894  // field. The other fields if any can be garbage.
2895  if (MPT->isMemberFunctionPointer())
2896  return Res;
2897 
2898  // Otherwise, emit a series of compares and combine the results.
2899  for (int I = 1, E = fields.size(); I < E; ++I) {
2900  llvm::Value *Field = Builder.CreateExtractValue(MemPtr, I);
2901  llvm::Value *Next = Builder.CreateICmpNE(Field, fields[I], "memptr.cmp");
2902  Res = Builder.CreateOr(Res, Next, "memptr.tobool");
2903  }
2904  return Res;
2905 }
2906 
2907 bool MicrosoftCXXABI::MemberPointerConstantIsNull(const MemberPointerType *MPT,
2908  llvm::Constant *Val) {
2909  // Function pointers are null if the pointer in the first field is null.
2910  if (MPT->isMemberFunctionPointer()) {
2911  llvm::Constant *FirstField = Val->getType()->isStructTy() ?
2912  Val->getAggregateElement(0U) : Val;
2913  return FirstField->isNullValue();
2914  }
2915 
2916  // If it's not a function pointer and it's zero initializable, we can easily
2917  // check zero.
2918  if (isZeroInitializable(MPT) && Val->isNullValue())
2919  return true;
2920 
2921  // Otherwise, break down all the fields for comparison. Hopefully these
2922  // little Constants are reused, while a big null struct might not be.
2924  GetNullMemberPointerFields(MPT, Fields);
2925  if (Fields.size() == 1) {
2926  assert(Val->getType()->isIntegerTy());
2927  return Val == Fields[0];
2928  }
2929 
2930  unsigned I, E;
2931  for (I = 0, E = Fields.size(); I != E; ++I) {
2932  if (Val->getAggregateElement(I) != Fields[I])
2933  break;
2934  }
2935  return I == E;
2936 }
2937 
2938 llvm::Value *
2939 MicrosoftCXXABI::GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
2940  Address This,
2941  llvm::Value *VBPtrOffset,
2942  llvm::Value *VBTableOffset,
2943  llvm::Value **VBPtrOut) {
2944  CGBuilderTy &Builder = CGF.Builder;
2945  // Load the vbtable pointer from the vbptr in the instance.
2946  This = Builder.CreateElementBitCast(This, CGM.Int8Ty);
2947  llvm::Value *VBPtr =
2948  Builder.CreateInBoundsGEP(This.getPointer(), VBPtrOffset, "vbptr");
2949  if (VBPtrOut) *VBPtrOut = VBPtr;
2950  VBPtr = Builder.CreateBitCast(VBPtr,
2951  CGM.Int32Ty->getPointerTo(0)->getPointerTo(This.getAddressSpace()));
2952 
2953  CharUnits VBPtrAlign;
2954  if (auto CI = dyn_cast<llvm::ConstantInt>(VBPtrOffset)) {
2955  VBPtrAlign = This.getAlignment().alignmentAtOffset(
2956  CharUnits::fromQuantity(CI->getSExtValue()));
2957  } else {
2958  VBPtrAlign = CGF.getPointerAlign();
2959  }
2960 
2961  llvm::Value *VBTable = Builder.CreateAlignedLoad(VBPtr, VBPtrAlign, "vbtable");
2962 
2963  // Translate from byte offset to table index. It improves analyzability.
2964  llvm::Value *VBTableIndex = Builder.CreateAShr(
2965  VBTableOffset, llvm::ConstantInt::get(VBTableOffset->getType(), 2),
2966  "vbtindex", /*isExact=*/true);
2967 
2968  // Load an i32 offset from the vb-table.
2969  llvm::Value *VBaseOffs = Builder.CreateInBoundsGEP(VBTable, VBTableIndex);
2970  VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0));
2971  return Builder.CreateAlignedLoad(VBaseOffs, CharUnits::fromQuantity(4),
2972  "vbase_offs");
2973 }
2974 
2975 // Returns an adjusted base cast to i8*, since we do more address arithmetic on
2976 // it.
2977 llvm::Value *MicrosoftCXXABI::AdjustVirtualBase(
2978  CodeGenFunction &CGF, const Expr *E, const CXXRecordDecl *RD,
2979  Address Base, llvm::Value *VBTableOffset, llvm::Value *VBPtrOffset) {
2980  CGBuilderTy &Builder = CGF.Builder;
2981  Base = Builder.CreateElementBitCast(Base, CGM.Int8Ty);
2982  llvm::BasicBlock *OriginalBB = nullptr;
2983  llvm::BasicBlock *SkipAdjustBB = nullptr;
2984  llvm::BasicBlock *VBaseAdjustBB = nullptr;
2985 
2986  // In the unspecified inheritance model, there might not be a vbtable at all,
2987  // in which case we need to skip the virtual base lookup. If there is a
2988  // vbtable, the first entry is a no-op entry that gives back the original
2989  // base, so look for a virtual base adjustment offset of zero.
2990  if (VBPtrOffset) {
2991  OriginalBB = Builder.GetInsertBlock();
2992  VBaseAdjustBB = CGF.createBasicBlock("memptr.vadjust");
2993  SkipAdjustBB = CGF.createBasicBlock("memptr.skip_vadjust");
2994  llvm::Value *IsVirtual =
2995  Builder.CreateICmpNE(VBTableOffset, getZeroInt(),
2996  "memptr.is_vbase");
2997  Builder.CreateCondBr(IsVirtual, VBaseAdjustBB, SkipAdjustBB);
2998  CGF.EmitBlock(VBaseAdjustBB);
2999  }
3000 
3001  // If we weren't given a dynamic vbptr offset, RD should be complete and we'll
3002  // know the vbptr offset.
3003  if (!VBPtrOffset) {
3004  CharUnits offs = CharUnits::Zero();
3005  if (!RD->hasDefinition()) {
3006  DiagnosticsEngine &Diags = CGF.CGM.getDiags();
3007  unsigned DiagID = Diags.getCustomDiagID(
3009  "member pointer representation requires a "
3010  "complete class type for %0 to perform this expression");
3011  Diags.Report(E->getExprLoc(), DiagID) << RD << E->getSourceRange();
3012  } else if (RD->getNumVBases())
3013  offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
3014  VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity());
3015  }
3016  llvm::Value *VBPtr = nullptr;
3017  llvm::Value *VBaseOffs =
3018  GetVBaseOffsetFromVBPtr(CGF, Base, VBPtrOffset, VBTableOffset, &VBPtr);
3019  llvm::Value *AdjustedBase = Builder.CreateInBoundsGEP(VBPtr, VBaseOffs);
3020 
3021  // Merge control flow with the case where we didn't have to adjust.
3022  if (VBaseAdjustBB) {
3023  Builder.CreateBr(SkipAdjustBB);
3024  CGF.EmitBlock(SkipAdjustBB);
3025  llvm::PHINode *Phi = Builder.CreatePHI(CGM.Int8PtrTy, 2, "memptr.base");
3026  Phi->addIncoming(Base.getPointer(), OriginalBB);
3027  Phi->addIncoming(AdjustedBase, VBaseAdjustBB);
3028  return Phi;
3029  }
3030  return AdjustedBase;
3031 }
3032 
3033 llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
3034  CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
3035  const MemberPointerType *MPT) {
3036  assert(MPT->isMemberDataPointer());
3037  unsigned AS = Base.getAddressSpace();
3038  llvm::Type *PType =
3039  CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
3040  CGBuilderTy &Builder = CGF.Builder;
3041  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
3042  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
3043 
3044  // Extract the fields we need, regardless of model. We'll apply them if we
3045  // have them.
3046  llvm::Value *FieldOffset = MemPtr;
3047  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
3048  llvm::Value *VBPtrOffset = nullptr;
3049  if (MemPtr->getType()->isStructTy()) {
3050  // We need to extract values.
3051  unsigned I = 0;
3052  FieldOffset = Builder.CreateExtractValue(MemPtr, I++);
3053  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
3054  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
3055  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
3056  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
3057  }
3058 
3059  llvm::Value *Addr;
3060  if (VirtualBaseAdjustmentOffset) {
3061  Addr = AdjustVirtualBase(CGF, E, RD, Base, VirtualBaseAdjustmentOffset,
3062  VBPtrOffset);
3063  } else {
3064  Addr = Base.getPointer();
3065  }
3066 
3067  // Cast to char*.
3068  Addr = Builder.CreateBitCast(Addr, CGF.Int8Ty->getPointerTo(AS));
3069 
3070  // Apply the offset, which we assume is non-null.
3071  Addr = Builder.CreateInBoundsGEP(Addr, FieldOffset, "memptr.offset");
3072 
3073  // Cast the address to the appropriate pointer type, adopting the address
3074  // space of the base pointer.
3075  return Builder.CreateBitCast(Addr, PType);
3076 }
3077 
3078 llvm::Value *
3079 MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
3080  const CastExpr *E,
3081  llvm::Value *Src) {
3082  assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
3083  E->getCastKind() == CK_BaseToDerivedMemberPointer ||
3084  E->getCastKind() == CK_ReinterpretMemberPointer);
3085 
3086  // Use constant emission if we can.
3087  if (isa<llvm::Constant>(Src))
3088  return EmitMemberPointerConversion(E, cast<llvm::Constant>(Src));
3089 
3090  // We may be adding or dropping fields from the member pointer, so we need
3091  // both types and the inheritance models of both records.
3092  const MemberPointerType *SrcTy =
3094  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3095  bool IsFunc = SrcTy->isMemberFunctionPointer();
3096 
3097  // If the classes use the same null representation, reinterpret_cast is a nop.
3098  bool IsReinterpret = E->getCastKind() == CK_ReinterpretMemberPointer;
3099  if (IsReinterpret && IsFunc)
3100  return Src;
3101 
3102  CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3103  CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3104  if (IsReinterpret &&
3105  SrcRD->nullFieldOffsetIsZero() == DstRD->nullFieldOffsetIsZero())
3106  return Src;
3107 
3108  CGBuilderTy &Builder = CGF.Builder;
3109 
3110  // Branch past the conversion if Src is null.
3111  llvm::Value *IsNotNull = EmitMemberPointerIsNotNull(CGF, Src, SrcTy);
3112  llvm::Constant *DstNull = EmitNullMemberPointer(DstTy);
3113 
3114  // C++ 5.2.10p9: The null member pointer value is converted to the null member
3115  // pointer value of the destination type.
3116  if (IsReinterpret) {
3117  // For reinterpret casts, sema ensures that src and dst are both functions
3118  // or data and have the same size, which means the LLVM types should match.
3119  assert(Src->getType() == DstNull->getType());
3120  return Builder.CreateSelect(IsNotNull, Src, DstNull);
3121  }
3122 
3123  llvm::BasicBlock *OriginalBB = Builder.GetInsertBlock();
3124  llvm::BasicBlock *ConvertBB = CGF.createBasicBlock("memptr.convert");
3125  llvm::BasicBlock *ContinueBB = CGF.createBasicBlock("memptr.converted");
3126  Builder.CreateCondBr(IsNotNull, ConvertBB, ContinueBB);
3127  CGF.EmitBlock(ConvertBB);
3128 
3129  llvm::Value *Dst = EmitNonNullMemberPointerConversion(
3130  SrcTy, DstTy, E->getCastKind(), E->path_begin(), E->path_end(), Src,
3131  Builder);
3132 
3133  Builder.CreateBr(ContinueBB);
3134 
3135  // In the continuation, choose between DstNull and Dst.
3136  CGF.EmitBlock(ContinueBB);
3137  llvm::PHINode *Phi = Builder.CreatePHI(DstNull->getType(), 2, "memptr.converted");
3138  Phi->addIncoming(DstNull, OriginalBB);
3139  Phi->addIncoming(Dst, ConvertBB);
3140  return Phi;
3141 }
3142 
3143 llvm::Value *MicrosoftCXXABI::EmitNonNullMemberPointerConversion(
3144  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3147  CGBuilderTy &Builder) {
3148  const CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3149  const CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3150  MSInheritanceAttr::Spelling SrcInheritance = SrcRD->getMSInheritanceModel();
3151  MSInheritanceAttr::Spelling DstInheritance = DstRD->getMSInheritanceModel();
3152  bool IsFunc = SrcTy->isMemberFunctionPointer();
3153  bool IsConstant = isa<llvm::Constant>(Src);
3154 
3155  // Decompose src.
3156  llvm::Value *FirstField = Src;
3157  llvm::Value *NonVirtualBaseAdjustment = getZeroInt();
3158  llvm::Value *VirtualBaseAdjustmentOffset = getZeroInt();
3159  llvm::Value *VBPtrOffset = getZeroInt();
3160  if (!MSInheritanceAttr::hasOnlyOneField(IsFunc, SrcInheritance)) {
3161  // We need to extract values.
3162  unsigned I = 0;
3163  FirstField = Builder.CreateExtractValue(Src, I++);
3164  if (MSInheritanceAttr::hasNVOffsetField(IsFunc, SrcInheritance))
3165  NonVirtualBaseAdjustment = Builder.CreateExtractValue(Src, I++);
3166  if (MSInheritanceAttr::hasVBPtrOffsetField(SrcInheritance))
3167  VBPtrOffset = Builder.CreateExtractValue(Src, I++);
3168  if (MSInheritanceAttr::hasVBTableOffsetField(SrcInheritance))
3169  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(Src, I++);
3170  }
3171 
3172  bool IsDerivedToBase = (CK == CK_DerivedToBaseMemberPointer);
3173  const MemberPointerType *DerivedTy = IsDerivedToBase ? SrcTy : DstTy;
3174  const CXXRecordDecl *DerivedClass = DerivedTy->getMostRecentCXXRecordDecl();
3175 
3176  // For data pointers, we adjust the field offset directly. For functions, we
3177  // have a separate field.
3178  llvm::Value *&NVAdjustField = IsFunc ? NonVirtualBaseAdjustment : FirstField;
3179 
3180  // The virtual inheritance model has a quirk: the virtual base table is always
3181  // referenced when dereferencing a member pointer even if the member pointer
3182  // is non-virtual. This is accounted for by adjusting the non-virtual offset
3183  // to point backwards to the top of the MDC from the first VBase. Undo this
3184  // adjustment to normalize the member pointer.
3185  llvm::Value *SrcVBIndexEqZero =
3186  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3187  if (SrcInheritance == MSInheritanceAttr::Keyword_virtual_inheritance) {
3188  if (int64_t SrcOffsetToFirstVBase =
3189  getContext().getOffsetOfBaseWithVBPtr(SrcRD).getQuantity()) {
3190  llvm::Value *UndoSrcAdjustment = Builder.CreateSelect(
3191  SrcVBIndexEqZero,
3192  llvm::ConstantInt::get(CGM.IntTy, SrcOffsetToFirstVBase),
3193  getZeroInt());
3194  NVAdjustField = Builder.CreateNSWAdd(NVAdjustField, UndoSrcAdjustment);
3195  }
3196  }
3197 
3198  // A non-zero vbindex implies that we are dealing with a source member in a
3199  // floating virtual base in addition to some non-virtual offset. If the
3200  // vbindex is zero, we are dealing with a source that exists in a non-virtual,
3201  // fixed, base. The difference between these two cases is that the vbindex +
3202  // nvoffset *always* point to the member regardless of what context they are
3203  // evaluated in so long as the vbindex is adjusted. A member inside a fixed
3204  // base requires explicit nv adjustment.
3205  llvm::Constant *BaseClassOffset = llvm::ConstantInt::get(
3206  CGM.IntTy,
3207  CGM.computeNonVirtualBaseClassOffset(DerivedClass, PathBegin, PathEnd)
3208  .getQuantity());
3209 
3210  llvm::Value *NVDisp;
3211  if (IsDerivedToBase)
3212  NVDisp = Builder.CreateNSWSub(NVAdjustField, BaseClassOffset, "adj");
3213  else
3214  NVDisp = Builder.CreateNSWAdd(NVAdjustField, BaseClassOffset, "adj");
3215 
3216  NVAdjustField = Builder.CreateSelect(SrcVBIndexEqZero, NVDisp, getZeroInt());
3217 
3218  // Update the vbindex to an appropriate value in the destination because
3219  // SrcRD's vbtable might not be a strict prefix of the one in DstRD.
3220  llvm::Value *DstVBIndexEqZero = SrcVBIndexEqZero;
3221  if (MSInheritanceAttr::hasVBTableOffsetField(DstInheritance) &&
3222  MSInheritanceAttr::hasVBTableOffsetField(SrcInheritance)) {
3223  if (llvm::GlobalVariable *VDispMap =
3224  getAddrOfVirtualDisplacementMap(SrcRD, DstRD)) {
3225  llvm::Value *VBIndex = Builder.CreateExactUDiv(
3226  VirtualBaseAdjustmentOffset, llvm::ConstantInt::get(CGM.IntTy, 4));
3227  if (IsConstant) {
3228  llvm::Constant *Mapping = VDispMap->getInitializer();
3229  VirtualBaseAdjustmentOffset =
3230  Mapping->getAggregateElement(cast<llvm::Constant>(VBIndex));
3231  } else {
3232  llvm::Value *Idxs[] = {getZeroInt(), VBIndex};
3233  VirtualBaseAdjustmentOffset =
3234  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(VDispMap, Idxs),
3236  }
3237 
3238  DstVBIndexEqZero =
3239  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3240  }
3241  }
3242 
3243  // Set the VBPtrOffset to zero if the vbindex is zero. Otherwise, initialize
3244  // it to the offset of the vbptr.
3245  if (MSInheritanceAttr::hasVBPtrOffsetField(DstInheritance)) {
3246  llvm::Value *DstVBPtrOffset = llvm::ConstantInt::get(
3247  CGM.IntTy,
3248  getContext().getASTRecordLayout(DstRD).getVBPtrOffset().getQuantity());
3249  VBPtrOffset =
3250  Builder.CreateSelect(DstVBIndexEqZero, getZeroInt(), DstVBPtrOffset);
3251  }
3252 
3253  // Likewise, apply a similar adjustment so that dereferencing the member
3254  // pointer correctly accounts for the distance between the start of the first
3255  // virtual base and the top of the MDC.
3256  if (DstInheritance == MSInheritanceAttr::Keyword_virtual_inheritance) {
3257  if (int64_t DstOffsetToFirstVBase =
3258  getContext().getOffsetOfBaseWithVBPtr(DstRD).getQuantity()) {
3259  llvm::Value *DoDstAdjustment = Builder.CreateSelect(
3260  DstVBIndexEqZero,
3261  llvm::ConstantInt::get(CGM.IntTy, DstOffsetToFirstVBase),
3262  getZeroInt());
3263  NVAdjustField = Builder.CreateNSWSub(NVAdjustField, DoDstAdjustment);
3264  }
3265  }
3266 
3267  // Recompose dst from the null struct and the adjusted fields from src.
3268  llvm::Value *Dst;
3269  if (MSInheritanceAttr::hasOnlyOneField(IsFunc, DstInheritance)) {
3270  Dst = FirstField;
3271  } else {
3272  Dst = llvm::UndefValue::get(ConvertMemberPointerType(DstTy));
3273  unsigned Idx = 0;
3274  Dst = Builder.CreateInsertValue(Dst, FirstField, Idx++);
3275  if (MSInheritanceAttr::hasNVOffsetField(IsFunc, DstInheritance))
3276  Dst = Builder.CreateInsertValue(Dst, NonVirtualBaseAdjustment, Idx++);
3277  if (MSInheritanceAttr::hasVBPtrOffsetField(DstInheritance))
3278  Dst = Builder.CreateInsertValue(Dst, VBPtrOffset, Idx++);
3279  if (MSInheritanceAttr::hasVBTableOffsetField(DstInheritance))
3280  Dst = Builder.CreateInsertValue(Dst, VirtualBaseAdjustmentOffset, Idx++);
3281  }
3282  return Dst;
3283 }
3284 
3285 llvm::Constant *
3286 MicrosoftCXXABI::EmitMemberPointerConversion(const CastExpr *E,
3287  llvm::Constant *Src) {
3288  const MemberPointerType *SrcTy =
3290  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3291 
3292  CastKind CK = E->getCastKind();
3293 
3294  return EmitMemberPointerConversion(SrcTy, DstTy, CK, E->path_begin(),
3295  E->path_end(), Src);
3296 }
3297 
3298 llvm::Constant *MicrosoftCXXABI::EmitMemberPointerConversion(
3299  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3301  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src) {
3302  assert(CK == CK_DerivedToBaseMemberPointer ||
3303  CK == CK_BaseToDerivedMemberPointer ||
3304  CK == CK_ReinterpretMemberPointer);
3305  // If src is null, emit a new null for dst. We can't return src because dst
3306  // might have a new representation.
3307  if (MemberPointerConstantIsNull(SrcTy, Src))
3308  return EmitNullMemberPointer(DstTy);
3309 
3310  // We don't need to do anything for reinterpret_casts of non-null member
3311  // pointers. We should only get here when the two type representations have
3312  // the same size.
3313  if (CK == CK_ReinterpretMemberPointer)
3314  return Src;
3315 
3316  CGBuilderTy Builder(CGM, CGM.getLLVMContext());
3317  auto *Dst = cast<llvm::Constant>(EmitNonNullMemberPointerConversion(
3318  SrcTy, DstTy, CK, PathBegin, PathEnd, Src, Builder));
3319 
3320  return Dst;
3321 }
3322 
3323 CGCallee MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(
3324  CodeGenFunction &CGF, const Expr *E, Address This,
3325  llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
3326  const MemberPointerType *MPT) {
3327  assert(MPT->isMemberFunctionPointer());
3328  const FunctionProtoType *FPT =
3330  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
3331  llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
3332  CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));
3333  CGBuilderTy &Builder = CGF.Builder;
3334 
3335  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
3336 
3337  // Extract the fields we need, regardless of model. We'll apply them if we
3338  // have them.
3339  llvm::Value *FunctionPointer = MemPtr;
3340  llvm::Value *NonVirtualBaseAdjustment = nullptr;
3341  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
3342  llvm::Value *VBPtrOffset = nullptr;
3343  if (MemPtr->getType()->isStructTy()) {
3344  // We need to extract values.
3345  unsigned I = 0;
3346  FunctionPointer = Builder.CreateExtractValue(MemPtr, I++);
3347  if (MSInheritanceAttr::hasNVOffsetField(MPT, Inheritance))
3348  NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++);
3349  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
3350  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
3351  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
3352  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
3353  }
3354 
3355  if (VirtualBaseAdjustmentOffset) {
3356  ThisPtrForCall = AdjustVirtualBase(CGF, E, RD, This,
3357  VirtualBaseAdjustmentOffset, VBPtrOffset);
3358  } else {
3359  ThisPtrForCall = This.getPointer();
3360  }
3361 
3362  if (NonVirtualBaseAdjustment) {
3363  // Apply the adjustment and cast back to the original struct type.
3364  llvm::Value *Ptr = Builder.CreateBitCast(ThisPtrForCall, CGF.Int8PtrTy);
3365  Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment);
3366  ThisPtrForCall = Builder.CreateBitCast(Ptr, ThisPtrForCall->getType(),
3367  "this.adjusted");
3368  }
3369 
3370  FunctionPointer =
3371  Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo());
3372  CGCallee Callee(FPT, FunctionPointer);
3373  return Callee;
3374 }
3375 
3377  return new MicrosoftCXXABI(CGM);
3378 }
3379 
3380 // MS RTTI Overview:
3381 // The run time type information emitted by cl.exe contains 5 distinct types of
3382 // structures. Many of them reference each other.
3383 //
3384 // TypeInfo: Static classes that are returned by typeid.
3385 //
3386 // CompleteObjectLocator: Referenced by vftables. They contain information
3387 // required for dynamic casting, including OffsetFromTop. They also contain
3388 // a reference to the TypeInfo for the type and a reference to the
3389 // CompleteHierarchyDescriptor for the type.
3390 //
3391 // ClassHierarchyDescriptor: Contains information about a class hierarchy.
3392 // Used during dynamic_cast to walk a class hierarchy. References a base
3393 // class array and the size of said array.
3394 //
3395 // BaseClassArray: Contains a list of classes in a hierarchy. BaseClassArray is
3396 // somewhat of a misnomer because the most derived class is also in the list
3397 // as well as multiple copies of virtual bases (if they occur multiple times
3398 // in the hierarchy.) The BaseClassArray contains one BaseClassDescriptor for
3399 // every path in the hierarchy, in pre-order depth first order. Note, we do
3400 // not declare a specific llvm type for BaseClassArray, it's merely an array
3401 // of BaseClassDescriptor pointers.
3402 //
3403 // BaseClassDescriptor: Contains information about a class in a class hierarchy.
3404 // BaseClassDescriptor is also somewhat of a misnomer for the same reason that
3405 // BaseClassArray is. It contains information about a class within a
3406 // hierarchy such as: is this base is ambiguous and what is its offset in the
3407 // vbtable. The names of the BaseClassDescriptors have all of their fields
3408 // mangled into them so they can be aggressively deduplicated by the linker.
3409 
3410 static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
3411  StringRef MangledName("??_7type_info@@6B@");
3412  if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
3413  return VTable;
3414  return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
3415  /*isConstant=*/true,
3417  /*Initializer=*/nullptr, MangledName);
3418 }
3419 
3420 namespace {
3421 
3422 /// A Helper struct that stores information about a class in a class
3423 /// hierarchy. The information stored in these structs struct is used during
3424 /// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
3425 // During RTTI creation, MSRTTIClasses are stored in a contiguous array with
3426 // implicit depth first pre-order tree connectivity. getFirstChild and
3427 // getNextSibling allow us to walk the tree efficiently.
3428 struct MSRTTIClass {
3429  enum {
3430  IsPrivateOnPath = 1 | 8,
3431  IsAmbiguous = 2,
3432  IsPrivate = 4,
3433  IsVirtual = 16,
3434  HasHierarchyDescriptor = 64
3435  };
3436  MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
3437  uint32_t initialize(const MSRTTIClass *Parent,
3438  const CXXBaseSpecifier *Specifier);
3439 
3440  MSRTTIClass *getFirstChild() { return this + 1; }
3441  static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
3442  return Child + 1 + Child->NumBases;
3443  }
3444 
3445  const CXXRecordDecl *RD, *VirtualRoot;
3446  uint32_t Flags, NumBases, OffsetInVBase;
3447 };
3448 
3449 /// Recursively initialize the base class array.
3450 uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
3451  const CXXBaseSpecifier *Specifier) {
3452  Flags = HasHierarchyDescriptor;
3453  if (!Parent) {
3454  VirtualRoot = nullptr;
3455  OffsetInVBase = 0;
3456  } else {
3457  if (Specifier->getAccessSpecifier() != AS_public)
3458  Flags |= IsPrivate | IsPrivateOnPath;
3459  if (Specifier->isVirtual()) {
3460  Flags |= IsVirtual;
3461  VirtualRoot = RD;
3462  OffsetInVBase = 0;
3463  } else {
3464  if (Parent->Flags & IsPrivateOnPath)
3465  Flags |= IsPrivateOnPath;
3466  VirtualRoot = Parent->VirtualRoot;
3467  OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
3469  }
3470  }
3471  NumBases = 0;
3472  MSRTTIClass *Child = getFirstChild();
3473  for (const CXXBaseSpecifier &Base : RD->bases()) {
3474  NumBases += Child->initialize(this, &Base) + 1;
3475  Child = getNextChild(Child);
3476  }
3477  return NumBases;
3478 }
3479 
3480 static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
3481  switch (Ty->getLinkage()) {
3482  case NoLinkage:
3483  case InternalLinkage:
3484  case UniqueExternalLinkage:
3486 
3487  case VisibleNoLinkage:
3488  case ModuleInternalLinkage:
3489  case ModuleLinkage:
3490  case ExternalLinkage:
3491  return llvm::GlobalValue::LinkOnceODRLinkage;
3492  }
3493  llvm_unreachable("Invalid linkage!");
3494 }
3495 
3496 /// An ephemeral helper class for building MS RTTI types. It caches some
3497 /// calls to the module and information about the most derived class in a
3498 /// hierarchy.
3499 struct MSRTTIBuilder {
3500  enum {
3501  HasBranchingHierarchy = 1,
3502  HasVirtualBranchingHierarchy = 2,
3503  HasAmbiguousBases = 4
3504  };
3505 
3506  MSRTTIBuilder(MicrosoftCXXABI &ABI, const CXXRecordDecl *RD)
3507  : CGM(ABI.CGM), Context(CGM.getContext()),
3508  VMContext(CGM.getLLVMContext()), Module(CGM.getModule()), RD(RD),
3509  Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
3510  ABI(ABI) {}
3511 
3512  llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
3513  llvm::GlobalVariable *
3514  getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
3515  llvm::GlobalVariable *getClassHierarchyDescriptor();
3516  llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo &Info);
3517 
3518  CodeGenModule &CGM;
3519  ASTContext &Context;
3520  llvm::LLVMContext &VMContext;
3521  llvm::Module &Module;
3522  const CXXRecordDecl *RD;
3523  llvm::GlobalVariable::LinkageTypes Linkage;
3524  MicrosoftCXXABI &ABI;
3525 };
3526 
3527 } // namespace
3528 
3529 /// Recursively serializes a class hierarchy in pre-order depth first
3530 /// order.
3532  const CXXRecordDecl *RD) {
3533  Classes.push_back(MSRTTIClass(RD));
3534  for (const CXXBaseSpecifier &Base : RD->bases())
3535  serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
3536 }
3537 
3538 /// Find ambiguity among base classes.
3539 static void
3541  llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
3542  llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
3543  llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
3544  for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
3545  if ((Class->Flags & MSRTTIClass::IsVirtual) &&
3546  !VirtualBases.insert(Class->RD).second) {
3547  Class = MSRTTIClass::getNextChild(Class);
3548  continue;
3549  }
3550  if (!UniqueBases.insert(Class->RD).second)
3551  AmbiguousBases.insert(Class->RD);
3552  Class++;
3553  }
3554  if (AmbiguousBases.empty())
3555  return;
3556  for (MSRTTIClass &Class : Classes)
3557  if (AmbiguousBases.count(Class.RD))
3558  Class.Flags |= MSRTTIClass::IsAmbiguous;
3559 }
3560 
3561 llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
3562  SmallString<256> MangledName;
3563  {
3564  llvm::raw_svector_ostream Out(MangledName);
3565  ABI.getMangleContext().mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
3566  }
3567 
3568  // Check to see if we've already declared this ClassHierarchyDescriptor.
3569  if (auto CHD = Module.getNamedGlobal(MangledName))
3570  return CHD;
3571 
3572  // Serialize the class hierarchy and initialize the CHD Fields.
3574  serializeClassHierarchy(Classes, RD);
3575  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
3576  detectAmbiguousBases(Classes);
3577  int Flags = 0;
3578  for (auto Class : Classes) {
3579  if (Class.RD->getNumBases() > 1)
3580  Flags |= HasBranchingHierarchy;
3581  // Note: cl.exe does not calculate "HasAmbiguousBases" correctly. We
3582  // believe the field isn't actually used.
3583  if (Class.Flags & MSRTTIClass::IsAmbiguous)
3584  Flags |= HasAmbiguousBases;
3585  }
3586  if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
3587  Flags |= HasVirtualBranchingHierarchy;
3588  // These gep indices are used to get the address of the first element of the
3589  // base class array.
3590  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
3591  llvm::ConstantInt::get(CGM.IntTy, 0)};
3592 
3593  // Forward-declare the class hierarchy descriptor
3594  auto Type = ABI.getClassHierarchyDescriptorType();
3595  auto CHD = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3596  /*Initializer=*/nullptr,
3597  MangledName);
3598  if (CHD->isWeakForLinker())
3599  CHD->setComdat(CGM.getModule().getOrInsertComdat(CHD->getName()));
3600 
3601  auto *Bases = getBaseClassArray(Classes);
3602 
3603  // Initialize the base class ClassHierarchyDescriptor.
3604  llvm::Constant *Fields[] = {
3605  llvm::ConstantInt::get(CGM.IntTy, 0), // reserved by the runtime
3606  llvm::ConstantInt::get(CGM.IntTy, Flags),
3607  llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
3608  ABI.getImageRelativeConstant(llvm::ConstantExpr::getInBoundsGetElementPtr(
3609  Bases->getValueType(), Bases,
3610  llvm::ArrayRef<llvm::Value *>(GEPIndices))),
3611  };
3612  CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3613  return CHD;
3614 }
3615 
3616 llvm::GlobalVariable *
3617 MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
3618  SmallString<256> MangledName;
3619  {
3620  llvm::raw_svector_ostream Out(MangledName);
3621  ABI.getMangleContext().mangleCXXRTTIBaseClassArray(RD, Out);
3622  }
3623 
3624  // Forward-declare the base class array.
3625  // cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
3626  // mode) bytes of padding. We provide a pointer sized amount of padding by
3627  // adding +1 to Classes.size(). The sections have pointer alignment and are
3628  // marked pick-any so it shouldn't matter.
3629  llvm::Type *PtrType = ABI.getImageRelativeType(
3630  ABI.getBaseClassDescriptorType()->getPointerTo());
3631  auto *ArrType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
3632  auto *BCA =
3633  new llvm::GlobalVariable(Module, ArrType,
3634  /*isConstant=*/true, Linkage,
3635  /*Initializer=*/nullptr, MangledName);
3636  if (BCA->isWeakForLinker())
3637  BCA->setComdat(CGM.getModule().getOrInsertComdat(BCA->getName()));
3638 
3639  // Initialize the BaseClassArray.
3640  SmallVector<llvm::Constant *, 8> BaseClassArrayData;
3641  for (MSRTTIClass &Class : Classes)
3642  BaseClassArrayData.push_back(
3643  ABI.getImageRelativeConstant(getBaseClassDescriptor(Class)));
3644  BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
3645  BCA->setInitializer(llvm::ConstantArray::get(ArrType, BaseClassArrayData));
3646  return BCA;
3647 }
3648 
3649 llvm::GlobalVariable *
3650 MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
3651  // Compute the fields for the BaseClassDescriptor. They are computed up front
3652  // because they are mangled into the name of the object.
3653  uint32_t OffsetInVBTable = 0;
3654  int32_t VBPtrOffset = -1;
3655  if (Class.VirtualRoot) {
3656  auto &VTableContext = CGM.getMicrosoftVTableContext();
3657  OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
3658  VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
3659  }
3660 
3661  SmallString<256> MangledName;
3662  {
3663  llvm::raw_svector_ostream Out(MangledName);
3664  ABI.getMangleContext().mangleCXXRTTIBaseClassDescriptor(
3665  Class.RD, Class.OffsetInVBase, VBPtrOffset, OffsetInVBTable,
3666  Class.Flags, Out);
3667  }
3668 
3669  // Check to see if we've already declared this object.
3670  if (auto BCD = Module.getNamedGlobal(MangledName))
3671  return BCD;
3672 
3673  // Forward-declare the base class descriptor.
3674  auto Type = ABI.getBaseClassDescriptorType();
3675  auto BCD =
3676  new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3677  /*Initializer=*/nullptr, MangledName);
3678  if (BCD->isWeakForLinker())
3679  BCD->setComdat(CGM.getModule().getOrInsertComdat(BCD->getName()));
3680 
3681  // Initialize the BaseClassDescriptor.
3682  llvm::Constant *Fields[] = {
3683  ABI.getImageRelativeConstant(
3684  ABI.getAddrOfRTTIDescriptor(Context.getTypeDeclType(Class.RD))),
3685  llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
3686  llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
3687  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
3688  llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
3689  llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
3690  ABI.getImageRelativeConstant(
3691  MSRTTIBuilder(ABI, Class.RD).getClassHierarchyDescriptor()),
3692  };
3693  BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3694  return BCD;
3695 }
3696 
3697 llvm::GlobalVariable *
3698 MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo &Info) {
3699  SmallString<256> MangledName;
3700  {
3701  llvm::raw_svector_ostream Out(MangledName);
3702  ABI.getMangleContext().mangleCXXRTTICompleteObjectLocator(RD, Info.MangledPath, Out);
3703  }
3704 
3705  // Check to see if we've already computed this complete object locator.
3706  if (auto COL = Module.getNamedGlobal(MangledName))
3707  return COL;
3708 
3709  // Compute the fields of the complete object locator.
3710  int OffsetToTop = Info.FullOffsetInMDC.getQuantity();
3711  int VFPtrOffset = 0;
3712  // The offset includes the vtordisp if one exists.
3713  if (const CXXRecordDecl *VBase = Info.getVBaseWithVPtr())
3714  if (Context.getASTRecordLayout(RD)
3716  .find(VBase)
3717  ->second.hasVtorDisp())
3718  VFPtrOffset = Info.NonVirtualOffset.getQuantity() + 4;
3719 
3720  // Forward-declare the complete object locator.
3721  llvm::StructType *Type = ABI.getCompleteObjectLocatorType();
3722  auto COL = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3723  /*Initializer=*/nullptr, MangledName);
3724 
3725  // Initialize the CompleteObjectLocator.
3726  llvm::Constant *Fields[] = {
3727  llvm::ConstantInt::get(CGM.IntTy, ABI.isImageRelative()),
3728  llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
3729  llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
3730  ABI.getImageRelativeConstant(
3731  CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(RD))),
3732  ABI.getImageRelativeConstant(getClassHierarchyDescriptor()),
3733  ABI.getImageRelativeConstant(COL),
3734  };
3735  llvm::ArrayRef<llvm::Constant *> FieldsRef(Fields);
3736  if (!ABI.isImageRelative())
3737  FieldsRef = FieldsRef.drop_back();
3738  COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
3739  if (COL->isWeakForLinker())
3740  COL->setComdat(CGM.getModule().getOrInsertComdat(COL->getName()));
3741  return COL;
3742 }
3743 
3745  bool &IsConst, bool &IsVolatile,
3746  bool &IsUnaligned) {
3747  T = Context.getExceptionObjectType(T);
3748 
3749  // C++14 [except.handle]p3:
3750  // A handler is a match for an exception object of type E if [...]
3751  // - the handler is of type cv T or const T& where T is a pointer type and
3752  // E is a pointer type that can be converted to T by [...]
3753  // - a qualification conversion
3754  IsConst = false;
3755  IsVolatile = false;
3756  IsUnaligned = false;
3757  QualType PointeeType = T->getPointeeType();
3758  if (!PointeeType.isNull()) {
3759  IsConst = PointeeType.isConstQualified();
3760  IsVolatile = PointeeType.isVolatileQualified();
3761  IsUnaligned = PointeeType.getQualifiers().hasUnaligned();
3762  }
3763 
3764  // Member pointer types like "const int A::*" are represented by having RTTI
3765  // for "int A::*" and separately storing the const qualifier.
3766  if (const auto *MPTy = T->getAs<MemberPointerType>())
3767  T = Context.getMemberPointerType(PointeeType.getUnqualifiedType(),
3768  MPTy->getClass());
3769 
3770  // Pointer types like "const int * const *" are represented by having RTTI
3771  // for "const int **" and separately storing the const qualifier.
3772  if (T->isPointerType())
3773  T = Context.getPointerType(PointeeType.getUnqualifiedType());
3774 
3775  return T;
3776 }
3777 
3779 MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
3780  QualType CatchHandlerType) {
3781  // TypeDescriptors for exceptions never have qualified pointer types,
3782  // qualifiers are stored separately in order to support qualification
3783  // conversions.
3784  bool IsConst, IsVolatile, IsUnaligned;
3785  Type =
3786  decomposeTypeForEH(getContext(), Type, IsConst, IsVolatile, IsUnaligned);
3787 
3788  bool IsReference = CatchHandlerType->isReferenceType();
3789 
3790  uint32_t Flags = 0;
3791  if (IsConst)
3792  Flags |= 1;
3793  if (IsVolatile)
3794  Flags |= 2;
3795  if (IsUnaligned)
3796  Flags |= 4;
3797  if (IsReference)
3798  Flags |= 8;
3799 
3800  return CatchTypeInfo{getAddrOfRTTIDescriptor(Type)->stripPointerCasts(),
3801  Flags};
3802 }
3803 
3804 /// Gets a TypeDescriptor. Returns a llvm::Constant * rather than a
3805 /// llvm::GlobalVariable * because different type descriptors have different
3806 /// types, and need to be abstracted. They are abstracting by casting the
3807 /// address to an Int8PtrTy.
3808 llvm::Constant *MicrosoftCXXABI::getAddrOfRTTIDescriptor(QualType Type) {
3809  SmallString<256> MangledName;
3810  {
3811  llvm::raw_svector_ostream Out(MangledName);
3812  getMangleContext().mangleCXXRTTI(Type, Out);
3813  }
3814 
3815  // Check to see if we've already declared this TypeDescriptor.
3816  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
3817  return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
3818 
3819  // Note for the future: If we would ever like to do deferred emission of
3820  // RTTI, check if emitting vtables opportunistically need any adjustment.
3821 
3822  // Compute the fields for the TypeDescriptor.
3823  SmallString<256> TypeInfoString;
3824  {
3825  llvm::raw_svector_ostream Out(TypeInfoString);
3826  getMangleContext().mangleCXXRTTIName(Type, Out);
3827  }
3828 
3829  // Declare and initialize the TypeDescriptor.
3830  llvm::Constant *Fields[] = {
3831  getTypeInfoVTable(CGM), // VFPtr
3832  llvm::ConstantPointerNull::get(CGM.Int8PtrTy), // Runtime data
3833  llvm::ConstantDataArray::getString(CGM.getLLVMContext(), TypeInfoString)};
3834  llvm::StructType *TypeDescriptorType =
3835  getTypeDescriptorType(TypeInfoString);
3836  auto *Var = new llvm::GlobalVariable(
3837  CGM.getModule(), TypeDescriptorType, /*isConstant=*/false,
3838  getLinkageForRTTI(Type),
3839  llvm::ConstantStruct::get(TypeDescriptorType, Fields),
3840  MangledName);
3841  if (Var->isWeakForLinker())
3842  Var->setComdat(CGM.getModule().getOrInsertComdat(Var->getName()));
3843  return llvm::ConstantExpr::getBitCast(Var, CGM.Int8PtrTy);
3844 }
3845 
3846 /// Gets or a creates a Microsoft CompleteObjectLocator.
3847 llvm::GlobalVariable *
3848 MicrosoftCXXABI::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
3849  const VPtrInfo &Info) {
3850  return MSRTTIBuilder(*this, RD).getCompleteObjectLocator(Info);
3851 }
3852 
3853 void MicrosoftCXXABI::emitCXXStructor(GlobalDecl GD) {
3854  if (auto *ctor = dyn_cast<CXXConstructorDecl>(GD.getDecl())) {
3855  // There are no constructor variants, always emit the complete destructor.
3856  llvm::Function *Fn =
3858  CGM.maybeSetTrivialComdat(*ctor, *Fn);
3859  return;
3860  }
3861 
3862  auto *dtor = cast<CXXDestructorDecl>(GD.getDecl());
3863 
3864  // Emit the base destructor if the base and complete (vbase) destructors are
3865  // equivalent. This effectively implements -mconstructor-aliases as part of
3866  // the ABI.
3867  if (GD.getDtorType() == Dtor_Complete &&
3868  dtor->getParent()->getNumVBases() == 0)
3869  GD = GD.getWithDtorType(Dtor_Base);
3870 
3871  // The base destructor is equivalent to the base destructor of its
3872  // base class if there is exactly one non-virtual base class with a
3873  // non-trivial destructor, there are no fields with a non-trivial
3874  // destructor, and the body of the destructor is trivial.
3875  if (GD.getDtorType() == Dtor_Base && !CGM.TryEmitBaseDestructorAsAlias(dtor))
3876  return;
3877 
3878  llvm::Function *Fn = CGM.codegenCXXStructor(GD);
3879  if (Fn->isWeakForLinker())
3880  Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName()));
3881 }
3882 
3883 llvm::Function *
3884 MicrosoftCXXABI::getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
3885  CXXCtorType CT) {
3886  assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure);
3887 
3888  // Calculate the mangled name.
3889  SmallString<256> ThunkName;
3890  llvm::raw_svector_ostream Out(ThunkName);
3891  getMangleContext().mangleCXXCtor(CD, CT, Out);
3892 
3893  // If the thunk has been generated previously, just return it.
3894  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
3895  return cast<llvm::Function>(GV);
3896 
3897  // Create the llvm::Function.
3898  const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeMSCtorClosure(CD, CT);
3899  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
3900  const CXXRecordDecl *RD = CD->getParent();
3901  QualType RecordTy = getContext().getRecordType(RD);
3902  llvm::Function *ThunkFn = llvm::Function::Create(
3903  ThunkTy, getLinkageForRTTI(RecordTy), ThunkName.str(), &CGM.getModule());
3904  ThunkFn->setCallingConv(static_cast<llvm::CallingConv::ID>(
3905  FnInfo.getEffectiveCallingConvention()));
3906  if (ThunkFn->isWeakForLinker())
3907  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
3908  bool IsCopy = CT == Ctor_CopyingClosure;
3909 
3910  // Start codegen.
3911  CodeGenFunction CGF(CGM);
3912  CGF.CurGD = GlobalDecl(CD, Ctor_Complete);
3913 
3914  // Build FunctionArgs.
3915  FunctionArgList FunctionArgs;
3916 
3917  // A constructor always starts with a 'this' pointer as its first argument.
3918  buildThisParam(CGF, FunctionArgs);
3919 
3920  // Following the 'this' pointer is a reference to the source object that we
3921  // are copying from.
3922  ImplicitParamDecl SrcParam(
3923  getContext(), /*DC=*/nullptr, SourceLocation(),
3924  &getContext().Idents.get("src"),
3925  getContext().getLValueReferenceType(RecordTy,
3926  /*SpelledAsLValue=*/true),
3928  if (IsCopy)
3929  FunctionArgs.push_back(&SrcParam);
3930 
3931  // Constructors for classes which utilize virtual bases have an additional
3932  // parameter which indicates whether or not it is being delegated to by a more
3933  // derived constructor.
3934  ImplicitParamDecl IsMostDerived(getContext(), /*DC=*/nullptr,
3935  SourceLocation(),
3936  &getContext().Idents.get("is_most_derived"),
3937  getContext().IntTy, ImplicitParamDecl::Other);
3938  // Only add the parameter to the list if the class has virtual bases.
3939  if (RD->getNumVBases() > 0)
3940  FunctionArgs.push_back(&IsMostDerived);
3941 
3942  // Start defining the function.
3943  auto NL = ApplyDebugLocation::CreateEmpty(CGF);
3944  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
3945  FunctionArgs, CD->getLocation(), SourceLocation());
3946  // Create a scope with an artificial location for the body of this function.
3947  auto AL = ApplyDebugLocation::CreateArtificial(CGF);
3948  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
3949  llvm::Value *This = getThisValue(CGF);
3950 
3951  llvm::Value *SrcVal =
3952  IsCopy ? CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(&SrcParam), "src")
3953  : nullptr;
3954 
3955  CallArgList Args;
3956 
3957  // Push the this ptr.
3958  Args.add(RValue::get(This), CD->getThisType());
3959 
3960  // Push the src ptr.
3961  if (SrcVal)
3962  Args.add(RValue::get(SrcVal), SrcParam.getType());
3963 
3964  // Add the rest of the default arguments.
3966  ArrayRef<ParmVarDecl *> params = CD->parameters().drop_front(IsCopy ? 1 : 0);
3967  for (const ParmVarDecl *PD : params) {
3968  assert(PD->hasDefaultArg() && "ctor closure lacks default args");
3969  ArgVec.push_back(PD->getDefaultArg());
3970  }
3971 
3972  CodeGenFunction::RunCleanupsScope Cleanups(CGF);
3973 
3974  const auto *FPT = CD->getType()->castAs<FunctionProtoType>();
3975  CGF.EmitCallArgs(Args, FPT, llvm::makeArrayRef(ArgVec), CD, IsCopy ? 1 : 0);
3976 
3977  // Insert any ABI-specific implicit constructor arguments.
3978  AddedStructorArgs ExtraArgs =
3979  addImplicitConstructorArgs(CGF, CD, Ctor_Complete,
3980  /*ForVirtualBase=*/false,
3981  /*Delegating=*/false, Args);
3982  // Call the destructor with our arguments.
3983  llvm::Constant *CalleePtr =
3985  CGCallee Callee =
3986  CGCallee::forDirect(CalleePtr, GlobalDecl(CD, Ctor_Complete));
3987  const CGFunctionInfo &CalleeInfo = CGM.getTypes().arrangeCXXConstructorCall(
3988  Args, CD, Ctor_Complete, ExtraArgs.Prefix, ExtraArgs.Suffix);
3989  CGF.EmitCall(CalleeInfo, Callee, ReturnValueSlot(), Args);
3990 
3991  Cleanups.ForceCleanup();
3992 
3993  // Emit the ret instruction, remove any temporary instructions created for the
3994  // aid of CodeGen.
3996 
3997  return ThunkFn;
3998 }
3999 
4000 llvm::Constant *MicrosoftCXXABI::getCatchableType(QualType T,
4001  uint32_t NVOffset,
4002  int32_t VBPtrOffset,
4003  uint32_t VBIndex) {
4004  assert(!T->isReferenceType());
4005 
4006  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
4007  const CXXConstructorDecl *CD =
4008  RD ? CGM.getContext().getCopyConstructorForExceptionObject(RD) : nullptr;
4010  if (CD)
4011  if (!hasDefaultCXXMethodCC(getContext(), CD) || CD->getNumParams() != 1)
4012  CT = Ctor_CopyingClosure;
4013 
4014  uint32_t Size = getContext().getTypeSizeInChars(T).getQuantity();
4015  SmallString<256> MangledName;
4016  {
4017  llvm::raw_svector_ostream Out(MangledName);
4018  getMangleContext().mangleCXXCatchableType(T, CD, CT, Size, NVOffset,
4019  VBPtrOffset, VBIndex, Out);
4020  }
4021  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
4022  return getImageRelativeConstant(GV);
4023 
4024  // The TypeDescriptor is used by the runtime to determine if a catch handler
4025  // is appropriate for the exception object.
4026  llvm::Constant *TD = getImageRelativeConstant(getAddrOfRTTIDescriptor(T));
4027 
4028  // The runtime is responsible for calling the copy constructor if the
4029  // exception is caught by value.
4030  llvm::Constant *CopyCtor;
4031  if (CD) {
4032  if (CT == Ctor_CopyingClosure)
4033  CopyCtor = getAddrOfCXXCtorClosure(CD, Ctor_CopyingClosure);
4034  else
4035  CopyCtor = CGM.getAddrOfCXXStructor(GlobalDecl(CD, Ctor_Complete));
4036 
4037  CopyCtor = llvm::ConstantExpr::getBitCast(CopyCtor, CGM.Int8PtrTy);
4038  } else {
4039  CopyCtor = llvm::Constant::getNullValue(CGM.Int8PtrTy);
4040  }
4041  CopyCtor = getImageRelativeConstant(CopyCtor);
4042 
4043  bool IsScalar = !RD;
4044  bool HasVirtualBases = false;
4045  bool IsStdBadAlloc = false; // std::bad_alloc is special for some reason.
4046  QualType PointeeType = T;
4047  if (T->isPointerType())
4048  PointeeType = T->getPointeeType();
4049  if (const CXXRecordDecl *RD = PointeeType->getAsCXXRecordDecl()) {
4050  HasVirtualBases = RD->getNumVBases() > 0;
4051  if (IdentifierInfo *II = RD->getIdentifier())
4052  IsStdBadAlloc = II->isStr("bad_alloc") && RD->isInStdNamespace();
4053  }
4054 
4055  // Encode the relevant CatchableType properties into the Flags bitfield.
4056  // FIXME: Figure out how bits 2 or 8 can get set.
4057  uint32_t Flags = 0;
4058  if (IsScalar)
4059  Flags |= 1;
4060  if (HasVirtualBases)
4061  Flags |= 4;
4062  if (IsStdBadAlloc)
4063  Flags |= 16;
4064 
4065  llvm::Constant *Fields[] = {
4066  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4067  TD, // TypeDescriptor
4068  llvm::ConstantInt::get(CGM.IntTy, NVOffset), // NonVirtualAdjustment
4069  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset), // OffsetToVBPtr
4070  llvm::ConstantInt::get(CGM.IntTy, VBIndex), // VBTableIndex
4071  llvm::ConstantInt::get(CGM.IntTy, Size), // Size
4072  CopyCtor // CopyCtor
4073  };
4074  llvm::StructType *CTType = getCatchableTypeType();
4075  auto *GV = new llvm::GlobalVariable(
4076  CGM.getModule(), CTType, /*isConstant=*/true, getLinkageForRTTI(T),
4077  llvm::ConstantStruct::get(CTType, Fields), MangledName);
4078  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4079  GV->setSection(".xdata");
4080  if (GV->isWeakForLinker())
4081  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4082  return getImageRelativeConstant(GV);
4083 }
4084 
4085 llvm::GlobalVariable *MicrosoftCXXABI::getCatchableTypeArray(QualType T) {
4086  assert(!T->isReferenceType());
4087 
4088  // See if we've already generated a CatchableTypeArray for this type before.
4089  llvm::GlobalVariable *&CTA = CatchableTypeArrays[T];
4090  if (CTA)
4091  return CTA;
4092 
4093  // Ensure that we don't have duplicate entries in our CatchableTypeArray by
4094  // using a SmallSetVector. Duplicates may arise due to virtual bases
4095  // occurring more than once in the hierarchy.
4097 
4098  // C++14 [except.handle]p3:
4099  // A handler is a match for an exception object of type E if [...]
4100  // - the handler is of type cv T or cv T& and T is an unambiguous public
4101  // base class of E, or
4102  // - the handler is of type cv T or const T& where T is a pointer type and
4103  // E is a pointer type that can be converted to T by [...]
4104  // - a standard pointer conversion (4.10) not involving conversions to
4105  // pointers to private or protected or ambiguous classes
4106  const CXXRecordDecl *MostDerivedClass = nullptr;
4107  bool IsPointer = T->isPointerType();
4108  if (IsPointer)
4109  MostDerivedClass = T->getPointeeType()->getAsCXXRecordDecl();
4110  else
4111  MostDerivedClass = T->getAsCXXRecordDecl();
4112 
4113  // Collect all the unambiguous public bases of the MostDerivedClass.
4114  if (MostDerivedClass) {
4115  const ASTContext &Context = getContext();
4116  const ASTRecordLayout &MostDerivedLayout =
4117  Context.getASTRecordLayout(MostDerivedClass);
4118  MicrosoftVTableContext &VTableContext = CGM.getMicrosoftVTableContext();
4120  serializeClassHierarchy(Classes, MostDerivedClass);
4121  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
4122  detectAmbiguousBases(Classes);
4123  for (const MSRTTIClass &Class : Classes) {
4124  // Skip any ambiguous or private bases.
4125  if (Class.Flags &
4126  (MSRTTIClass::IsPrivateOnPath | MSRTTIClass::IsAmbiguous))
4127  continue;
4128  // Write down how to convert from a derived pointer to a base pointer.
4129  uint32_t OffsetInVBTable = 0;
4130  int32_t VBPtrOffset = -1;
4131  if (Class.VirtualRoot) {
4132  OffsetInVBTable =
4133  VTableContext.getVBTableIndex(MostDerivedClass, Class.VirtualRoot)*4;
4134  VBPtrOffset = MostDerivedLayout.getVBPtrOffset().getQuantity();
4135  }
4136 
4137  // Turn our record back into a pointer if the exception object is a
4138  // pointer.
4139  QualType RTTITy = QualType(Class.RD->getTypeForDecl(), 0);
4140  if (IsPointer)
4141  RTTITy = Context.getPointerType(RTTITy);
4142  CatchableTypes.insert(getCatchableType(RTTITy, Class.OffsetInVBase,
4143  VBPtrOffset, OffsetInVBTable));
4144  }
4145  }
4146 
4147  // C++14 [except.handle]p3:
4148  // A handler is a match for an exception object of type E if
4149  // - The handler is of type cv T or cv T& and E and T are the same type
4150  // (ignoring the top-level cv-qualifiers)
4151  CatchableTypes.insert(getCatchableType(T));
4152 
4153  // C++14 [except.handle]p3:
4154  // A handler is a match for an exception object of type E if
4155  // - the handler is of type cv T or const T& where T is a pointer type and
4156  // E is a pointer type that can be converted to T by [...]
4157  // - a standard pointer conversion (4.10) not involving conversions to
4158  // pointers to private or protected or ambiguous classes
4159  //
4160  // C++14 [conv.ptr]p2:
4161  // A prvalue of type "pointer to cv T," where T is an object type, can be
4162  // converted to a prvalue of type "pointer to cv void".
4163  if (IsPointer && T->getPointeeType()->isObjectType())
4164  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4165 
4166  // C++14 [except.handle]p3:
4167  // A handler is a match for an exception object of type E if [...]
4168  // - the handler is of type cv T or const T& where T is a pointer or
4169  // pointer to member type and E is std::nullptr_t.
4170  //
4171  // We cannot possibly list all possible pointer types here, making this
4172  // implementation incompatible with the standard. However, MSVC includes an
4173  // entry for pointer-to-void in this case. Let's do the same.
4174  if (T->isNullPtrType())
4175  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4176 
4177  uint32_t NumEntries = CatchableTypes.size();
4178  llvm::Type *CTType =
4179  getImageRelativeType(getCatchableTypeType()->getPointerTo());
4180  llvm::ArrayType *AT = llvm::ArrayType::get(CTType, NumEntries);
4181  llvm::StructType *CTAType = getCatchableTypeArrayType(NumEntries);
4182  llvm::Constant *Fields[] = {
4183  llvm::ConstantInt::get(CGM.IntTy, NumEntries), // NumEntries
4184  llvm::ConstantArray::get(
4185  AT, llvm::makeArrayRef(CatchableTypes.begin(),
4186  CatchableTypes.end())) // CatchableTypes
4187  };
4188  SmallString<256> MangledName;
4189  {
4190  llvm::raw_svector_ostream Out(MangledName);
4191  getMangleContext().mangleCXXCatchableTypeArray(T, NumEntries, Out);
4192  }
4193  CTA = new llvm::GlobalVariable(
4194  CGM.getModule(), CTAType, /*isConstant=*/true, getLinkageForRTTI(T),
4195  llvm::ConstantStruct::get(CTAType, Fields), MangledName);
4196  CTA->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4197  CTA->setSection(".xdata");
4198  if (CTA->isWeakForLinker())
4199  CTA->setComdat(CGM.getModule().getOrInsertComdat(CTA->getName()));
4200  return CTA;
4201 }
4202 
4203 llvm::GlobalVariable *MicrosoftCXXABI::getThrowInfo(QualType T) {
4204  bool IsConst, IsVolatile, IsUnaligned;
4205  T = decomposeTypeForEH(getContext(), T, IsConst, IsVolatile, IsUnaligned);
4206 
4207  // The CatchableTypeArray enumerates the various (CV-unqualified) types that
4208  // the exception object may be caught as.
4209  llvm::GlobalVariable *CTA = getCatchableTypeArray(T);
4210  // The first field in a CatchableTypeArray is the number of CatchableTypes.
4211  // This is used as a component of the mangled name which means that we need to
4212  // know what it is in order to see if we have previously generated the
4213  // ThrowInfo.
4214  uint32_t NumEntries =
4215  cast<llvm::ConstantInt>(CTA->getInitializer()->getAggregateElement(0U))
4216  ->getLimitedValue();
4217 
4218  SmallString<256> MangledName;
4219  {
4220  llvm::raw_svector_ostream Out(MangledName);
4221  getMangleContext().mangleCXXThrowInfo(T, IsConst, IsVolatile, IsUnaligned,
4222  NumEntries, Out);
4223  }
4224 
4225  // Reuse a previously generated ThrowInfo if we have generated an appropriate
4226  // one before.
4227  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
4228  return GV;
4229 
4230  // The RTTI TypeDescriptor uses an unqualified type but catch clauses must
4231  // be at least as CV qualified. Encode this requirement into the Flags
4232  // bitfield.
4233  uint32_t Flags = 0;
4234  if (IsConst)
4235  Flags |= 1;
4236  if (IsVolatile)
4237  Flags |= 2;
4238  if (IsUnaligned)
4239  Flags |= 4;
4240 
4241  // The cleanup-function (a destructor) must be called when the exception
4242  // object's lifetime ends.
4243  llvm::Constant *CleanupFn = llvm::Constant::getNullValue(CGM.Int8PtrTy);
4244  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4245  if (CXXDestructorDecl *DtorD = RD->getDestructor())
4246  if (!DtorD->isTrivial())
4247  CleanupFn = llvm::ConstantExpr::getBitCast(
4249  CGM.Int8PtrTy);
4250  // This is unused as far as we can tell, initialize it to null.
4251  llvm::Constant *ForwardCompat =
4252  getImageRelativeConstant(llvm::Constant::getNullValue(CGM.Int8PtrTy));
4253  llvm::Constant *PointerToCatchableTypes = getImageRelativeConstant(
4254  llvm::ConstantExpr::getBitCast(CTA, CGM.Int8PtrTy));
4255  llvm::StructType *TIType = getThrowInfoType();
4256  llvm::Constant *Fields[] = {
4257  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4258  getImageRelativeConstant(CleanupFn), // CleanupFn
4259  ForwardCompat, // ForwardCompat
4260  PointerToCatchableTypes // CatchableTypeArray
4261  };
4262  auto *GV = new llvm::GlobalVariable(
4263  CGM.getModule(), TIType, /*isConstant=*/true, getLinkageForRTTI(T),
4264  llvm::ConstantStruct::get(TIType, Fields), StringRef(MangledName));
4265  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4266  GV->setSection(".xdata");
4267  if (GV->isWeakForLinker())
4268  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4269  return GV;
4270 }
4271 
4272 void MicrosoftCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
4273  const Expr *SubExpr = E->getSubExpr();
4274  QualType ThrowType = SubExpr->getType();
4275  // The exception object lives on the stack and it's address is passed to the
4276  // runtime function.
4277  Address AI = CGF.CreateMemTemp(ThrowType);
4278  CGF.EmitAnyExprToMem(SubExpr, AI, ThrowType.getQualifiers(),
4279  /*IsInit=*/true);
4280 
4281  // The so-called ThrowInfo is used to describe how the exception object may be
4282  // caught.
4283  llvm::GlobalVariable *TI = getThrowInfo(ThrowType);
4284 
4285  // Call into the runtime to throw the exception.
4286  llvm::Value *Args[] = {
4287  CGF.Builder.CreateBitCast(AI.getPointer(), CGM.Int8PtrTy),
4288  TI
4289  };
4291 }
4292 
4293 std::pair<llvm::Value *, const CXXRecordDecl *>
4294 MicrosoftCXXABI::LoadVTablePtr(CodeGenFunction &CGF, Address This,
4295  const CXXRecordDecl *RD) {
4296  std::tie(This, std::ignore, RD) =
4297  performBaseAdjustment(CGF, This, QualType(RD->getTypeForDecl(), 0));
4298  return {CGF.GetVTablePtr(This, CGM.Int8PtrTy, RD), RD};
4299 }
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:363
void EmitCXXGuardedInitBranch(llvm::Value *NeedsInit, llvm::BasicBlock *InitBlock, llvm::BasicBlock *NoInitBlock, GuardKind Kind, const VarDecl *D)
Emit a branch to select whether or not to perform guarded initialization.
Definition: CGDeclCXX.cpp:297
static QualType decomposeTypeForEH(ASTContext &Context, QualType T, bool &IsConst, bool &IsVolatile, bool &IsUnaligned)
llvm::IntegerType * IntTy
int
void setSRetAfterThis(bool AfterThis)
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:59
Other implicit parameter.
Definition: Decl.h:1560
Complete object ctor.
Definition: ABI.h:25
A (possibly-)qualified type.
Definition: Type.h:643
static llvm::CallBase * emitRTtypeidCall(CodeGenFunction &CGF, llvm::Value *Argument)
base_class_range bases()
Definition: DeclCXX.h:586
llvm::Type * ConvertTypeForMem(QualType T)
unsigned getNumBases() const
Retrieves the number of base classes of this class.
Definition: DeclCXX.h:580
uint32_t VBPtrOffset
The offset (in bytes) of the vbptr, relative to the beginning of the derived class.
Definition: ABI.h:60
Internal linkage according to the Modules TS, but can be referred to from other translation units ind...
Definition: Linkage.h:49
const Expr * getSubExpr() const
Definition: ExprCXX.h:1071
Address CreateMemTemp(QualType T, const Twine &Name="tmp", Address *Alloca=nullptr)
CreateMemTemp - Create a temporary memory object of the given type, with appropriate alignmen and cas...
Definition: CGExpr.cpp:139
bool isEmpty() const
Definition: ABI.h:154
llvm::LLVMContext & getLLVMContext()
static void detectAmbiguousBases(SmallVectorImpl< MSRTTIClass > &Classes)
Find ambiguity among base classes.
CXXDtorType getDtorType() const
Definition: GlobalDecl.h:84
The standard implementation of ConstantInitBuilder used in Clang.
const ASTRecordLayout & getASTRecordLayout(const RecordDecl *D) const
Get or compute information about the layout of the specified record (struct/union/class) D...
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:557
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:991
CharUnits getBaseClassOffset(const CXXRecordDecl *Base) const
getBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:232
No linkage, which means that the entity is unique and can only be referred to from within its scope...
Definition: Linkage.h:26
unsigned getNumVBases() const
Retrieves the number of virtual base classes of this class.
Definition: DeclCXX.h:601
QualType getThisType() const
Return the type of the this pointer.
Definition: DeclCXX.cpp:2310
bool isEmpty() const
Definition: ABI.h:86
const Type * getTypeForDecl() const
Definition: Decl.h:2967
llvm::Constant * getAddrOfCXXStructor(GlobalDecl GD, const CGFunctionInfo *FnInfo=nullptr, llvm::FunctionType *FnType=nullptr, bool DontDefer=false, ForDefinition_t IsForDefinition=NotForDefinition)
Return the address of the constructor/destructor of the given type.
bool isVariadic() const
Whether this function prototype is variadic.
Definition: Type.h:4041
CharUnits VFPtrOffset
This is the offset of the vfptr from the start of the last vbase, or the complete type if there are n...
const CGFunctionInfo & arrangeCXXMethodType(const CXXRecordDecl *RD, const FunctionProtoType *FTP, const CXXMethodDecl *MD)
Arrange the argument and result information for a call to an unknown C++ non-static member function o...
Definition: CGCall.cpp:250
bool isVirtual() const
Definition: DeclCXX.h:1935
const Decl * CurCodeDecl
CurCodeDecl - This is the inner-most code context, which includes blocks.
bool isVirtual() const
Determines whether the base class is a virtual base class (or not).
Definition: DeclCXX.h:200
bool isPOD() const
Whether this class is a POD-type (C++ [class]p4)
Definition: DeclCXX.h:1082
The base class of the type hierarchy.
Definition: Type.h:1436
int64_t NonVirtual
The non-virtual adjustment from the derived object to its nearest virtual base.
Definition: ABI.h:110
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1290
bool isZero() const
isZero - Test whether the quantity equals zero.
Definition: CharUnits.h:116
const NestedNameSpecifier * Specifier
bool isFuncTypeConvertible(const FunctionType *FT)
isFuncTypeConvertible - Utility to check whether a function type can be converted to an LLVM type (i...
Linkage getLinkage() const
Determine the linkage of this type.
Definition: Type.cpp:3718
BasePath MangledPath
The bases from the inheritance path that got used to mangle the vbtable name.
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2352
bool TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D)
Try to emit a base destructor as an alias to its primary base-class destructor.
Definition: CGCXX.cpp:33
static llvm::FunctionCallee getInitThreadFooterFn(CodeGenModule &CGM)
Default closure variant of a ctor.
Definition: ABI.h:29
MSInheritanceAttr::Spelling getMSInheritanceModel() const
Returns the inheritance model used for this record.
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2498
const CXXBaseSpecifier *const * path_const_iterator
Definition: Expr.h:3194
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
GlobalDecl getWithCtorType(CXXCtorType Type)
Definition: GlobalDecl.h:123
Represents a variable declaration or definition.
Definition: Decl.h:827
Address getObjectAddress(CodeGenFunction &CGF) const
Returns the address of the object within this declaration.
const CXXRecordDecl * VBase
If nonnull, holds the last vbase which contains the vfptr that the method definition is adjusted to...
const internal::VariadicDynCastAllOfMatcher< Stmt, Expr > expr
Matches expressions.
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6858
bool This(InterpState &S, CodePtr OpPC)
Definition: Interp.h:830
A this pointer adjustment.
Definition: ABI.h:107
void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type, bool ForVirtualBase, bool Delegating, Address This, QualType ThisTy)
Definition: CGClass.cpp:2411
DiagnosticsEngine & getDiags() const
Address CreateConstInBoundsByteGEP(Address Addr, CharUnits Offset, const llvm::Twine &Name="")
Given a pointer to i8, adjust it by a given constant offset.
Definition: CGBuilder.h:244
QualType getMemberPointerType(QualType T, const Type *Cls) const
Return the uniqued reference to the type for a member pointer to the specified type in the specified ...
llvm::Value * getPointer() const
Definition: Address.h:37
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:1049
bool hasDefinition() const
Definition: DeclCXX.h:539
Represents a parameter to a function.
Definition: Decl.h:1600
Linkage
Describes the different kinds of linkage (C++ [basic.link], C99 6.2.2) that an entity may have...
Definition: Linkage.h:23
unsigned getAddressSpace() const
Return the address space that this address resides in.
Definition: Address.h:56
void add(RValue rvalue, QualType type)
Definition: CGCall.h:287
const ValueDecl * getMemberPointerDecl() const
Definition: APValue.cpp:798
CharUnits getBaseOffset() const
getBaseOffset - Returns the base class offset.
Definition: BaseSubobject.h:46
int32_t VBOffsetOffset
The offset (in bytes) of the vbase offset in the vbtable.
Definition: ABI.h:131
DeclarationName getDeclName() const
Get the actual, stored name of the declaration, which may be a special name.
Definition: Decl.h:297
One of these records is kept for each identifier that is lexed.
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:160
virtual void mangleCXXVFTable(const CXXRecordDecl *Derived, ArrayRef< const CXXRecordDecl *> BasePath, raw_ostream &Out)=0
Mangle vftable symbols.
bool ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD)
Returns whether we should perform a type checked load when loading a virtual function for virtual cal...
Definition: CGClass.cpp:2785
bool Zero(InterpState &S, CodePtr OpPC)
Definition: Interp.h:815
bool isReferenceType() const
Definition: Type.h:6403
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:80
A return adjustment.
Definition: ABI.h:41
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
CharUnits getVBaseClassOffset(const CXXRecordDecl *VBase) const
getVBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:240
__DEVICE__ int max(int __a, int __b)
Expr * getSubExpr()
Definition: Expr.h:3177
void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::FunctionCallee fn, llvm::Constant *addr)
Call atexit() with a function that passes the given argument to the given function.
Definition: CGDeclCXX.cpp:261
Describes a module or submodule.
Definition: Module.h:64
static llvm::FunctionCallee getThrowFn(CodeGenModule &CGM)
IdentifierTable & Idents
Definition: ASTContext.h:579
bool hasPrivateFields() const
Definition: DeclCXX.h:1099
bool hasProtectedFields() const
Definition: DeclCXX.h:1103
static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF)
Apply TemporaryLocation if it is valid.
Definition: CGDebugInfo.h:742
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2325
static bool hasMicrosoftABIRestrictions(const CXXRecordDecl *RD)
ArrayRef< VTableComponent > vtable_components() const
FunctionDecl * getOperatorDelete() const
Definition: ExprCXX.h:2308
Base object ctor.
Definition: ABI.h:26
Address CreateElementBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Cast the element type of the given address to a different type, preserving information like the align...
Definition: CGBuilder.h:156
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:38
void EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD, llvm::Value *VTable, SourceLocation Loc)
If whole-program virtual table optimization is enabled, emit an assumption that VTable is a member of...
Definition: CGClass.cpp:2635
AccessSpecifier getAccessSpecifier() const
Returns the access specifier for this base specifier.
Definition: DeclCXX.h:227
llvm::Align getAsAlign() const
getAsAlign - Returns Quantity as a valid llvm::Align, Beware llvm::Align assumes power of two 8-bit b...
Definition: CharUnits.h:183
llvm::CallInst * EmitRuntimeCall(llvm::FunctionCallee callee, const Twine &name="")
const CXXRecordDecl * IntroducingObject
This is the class that introduced the vptr by declaring new virtual methods or virtual bases...
path_iterator path_begin()
Definition: Expr.h:3197
Deleting dtor.
Definition: ABI.h:34
CharUnits getAlignment() const
Return the alignment of this pointer.
Definition: Address.h:66
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:149
static ConstantAddress getInitThreadEpochPtr(CodeGenModule &CGM)
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6218
const CGFunctionInfo & arrangeCXXConstructorCall(const CallArgList &Args, const CXXConstructorDecl *D, CXXCtorType CtorKind, unsigned ExtraPrefixArgs, unsigned ExtraSuffixArgs, bool PassProtoArgs=true)
Arrange a call to a C++ method, passing the given arguments.
Definition: CGCall.cpp:389
QualType getExceptionObjectType(QualType T) const
const VPtrInfoVector & getVFPtrOffsets(const CXXRecordDecl *RD)
const Type * getTypePtr() const
Retrieves a pointer to the underlying (unqualified) type.
Definition: Type.h:6148
CXXRecordDecl * getCanonicalDecl() override
Retrieves the "canonical" declaration of the given declaration.
Definition: DeclCXX.h:491
void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr, QualType DeleteTy, llvm::Value *NumElements=nullptr, CharUnits CookieSize=CharUnits())
Definition: CGExprCXX.cpp:1751
static bool hasDefaultCXXMethodCC(ASTContext &Context, const CXXMethodDecl *MD)
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
Denotes a cleanup that should run when a scope is exited using normal control flow (falling off the e...
Definition: EHScopeStack.h:84
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3125
void ForceCleanup(std::initializer_list< llvm::Value **> ValuesToReload={})
Force the emission of cleanups now, instead of waiting until this object is destroyed.
const VBaseOffsetsMapTy & getVBaseOffsetsMap() const
Definition: RecordLayout.h:315
const CGFunctionInfo & arrangeCXXMethodDeclaration(const CXXMethodDecl *MD)
C++ methods have some special rules and also have implicit parameters.
Definition: CGCall.cpp:278
GlobalDecl CurGD
CurGD - The GlobalDecl for the current function being compiled.
bool isInstance() const
Definition: DeclCXX.h:1918
CXXDestructorDecl * getDestructor() const
Returns the destructor decl for this class.
Definition: DeclCXX.cpp:1765
GlobalDecl getWithDtorType(CXXDtorType Type)
Definition: GlobalDecl.h:130
CallingConv getDefaultCallingConvention(bool IsVariadic, bool IsCXXMethod, bool IsBuiltin=false) const
Retrieves the default calling convention for the current target.
bool isNegative() const
isNegative - Test whether the quantity is less than zero.
Definition: CharUnits.h:125
CXXRecordDecl * getMostRecentNonInjectedDecl()
Definition: DeclCXX.h:517
static ImplicitParamDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, ImplicitParamKind ParamKind)
Create implicit parameter.
Definition: Decl.cpp:4601
NodeId Parent
Definition: ASTDiff.cpp:191
bool hasAttr() const
Definition: DeclBase.h:542
CanQualType getReturnType() const
static void emitGlobalDtorWithTLRegDtor(CodeGenFunction &CGF, const VarDecl &VD, llvm::FunctionCallee Dtor, llvm::Constant *Addr)
AutoVarEmission EmitAutoVarAlloca(const VarDecl &var)
EmitAutoVarAlloca - Emit the alloca and debug information for a local variable.
Definition: CGDecl.cpp:1373
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1692
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3725
void EmitAnyExprToMem(const Expr *E, Address Location, Qualifiers Quals, bool IsInitializer)
EmitAnyExprToMem - Emits the code necessary to evaluate an arbitrary expression into the given memory...
Definition: CGExpr.cpp:223
CastKind
CastKind - The kind of operation required for a conversion.
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:38
union clang::ReturnAdjustment::VirtualAdjustment Virtual
Module linkage, which indicates that the entity can be referred to from other translation units withi...
Definition: Linkage.h:55
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
unsigned Offset
Definition: Format.cpp:1809
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:38
llvm::Value * GetVTablePtr(Address This, llvm::Type *VTableTy, const CXXRecordDecl *VTableClass)
GetVTablePtr - Return the Value of the vtable pointer member pointed to by This.
Definition: CGClass.cpp:2585
CXXDtorType
C++ destructor types.
Definition: ABI.h:33
Represent the declaration of a variable (in which case it is an lvalue) a function (in which case it ...
Definition: Decl.h:644
This represents one expression.
Definition: Expr.h:108
bool isPositive() const
isPositive - Test whether the quantity is greater than zero.
Definition: CharUnits.h:122
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
void EmitCallArgs(CallArgList &Args, const T *CallArgTypeInfo, llvm::iterator_range< CallExpr::const_arg_iterator > ArgRange, AbstractCallee AC=AbstractCallee(), unsigned ParamsToSkip=0, EvaluationOrder Order=EvaluationOrder::Default)
EmitCallArgs - Emit call arguments for a function.
const CGFunctionInfo & arrangeNullaryFunction()
A nullary function is a freestanding function of type &#39;void ()&#39;.
Definition: CGCall.cpp:694
static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM)
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6923
static CGCallee forDirect(llvm::Constant *functionPtr, const CGCalleeInfo &abstractInfo=CGCalleeInfo())
Definition: CGCall.h:133
#define V(N, I)
Definition: ASTContext.h:2921
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2616
VarDecl * getExceptionDecl() const
Definition: StmtCXX.h:49
QualType getTagDeclType(const TagDecl *Decl) const
Return the unique reference to the type for the specified TagDecl (struct/union/class/enum) decl...
bool isNullPtrType() const
Definition: Type.h:6675
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:43
CharUnits getTypeAlignInChars(QualType T) const
Return the ABI-specified alignment of a (complete) type T, in characters.
DeclContext * getDeclContext()
Definition: DeclBase.h:438
TLSKind getTLSKind() const
Definition: Decl.cpp:1981
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
MicrosoftVTableContext & getMicrosoftVTableContext()
static bool classifyReturnType(const CGCXXABI &CXXABI, CGFunctionInfo &FI, const ABIInfo &Info)
Definition: TargetInfo.cpp:158
llvm::LLVMContext & getLLVMContext()
const CXXRecordDecl * getBase() const
getBase - Returns the base class declaration.
Definition: BaseSubobject.h:43
bool isPolymorphic() const
Whether this class is polymorphic (C++ [class.virtual]), which means that the class contains or inher...
Definition: DeclCXX.h:1115
Base object dtor.
Definition: ABI.h:36
QualType getType() const
Definition: Expr.h:137
bool hasNonTrivialDestructor() const
Determine whether this class has a non-trivial destructor (C++ [class.dtor]p3)
Definition: DeclCXX.h:1277
bool hasExtendableVFPtr() const
hasVFPtr - Does this class have a virtual function table pointer that can be extended by a derived cl...
Definition: RecordLayout.h:267
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1779
void GenerateCXXGlobalInitFunc(llvm::Function *Fn, ArrayRef< llvm::Function *> CXXThreadLocals, ConstantAddress Guard=ConstantAddress::invalid())
GenerateCXXGlobalInitFunc - Generates code for initializing global variables.
Definition: CGDeclCXX.cpp:664
llvm::Value * EmitCastToVoidPtr(llvm::Value *value)
Emit a cast to void* in the appropriate address space.
Definition: CGExpr.cpp:50
CharUnits getVBPtrOffset() const
getVBPtrOffset - Get the offset for virtual base table pointer.
Definition: RecordLayout.h:305
const TargetInfo & getTarget() const
void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr, bool PerformInit)
EmitCXXGlobalVarDeclInit - Create the initializer for a C++ variable with global storage.
Definition: CGDeclCXX.cpp:172
QualType getTypeDeclType(const TypeDecl *Decl, const TypeDecl *PrevDecl=nullptr) const
Return the unique reference to the type for the specified type declaration.
Definition: ASTContext.h:1403
ASTContext & getContext() const
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:708
bool nullFieldOffsetIsZero() const
In the Microsoft C++ ABI, use zero for the field offset of a null data member pointer if we can guara...
Definition: DeclCXX.h:1738
The COMDAT used for dtors.
Definition: ABI.h:37
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:265
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:40
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:6207
The l-value was considered opaque, so the alignment was determined from a type.
int64_t NonVirtual
The non-virtual adjustment from the derived object to its nearest virtual base.
Definition: ABI.h:44
unsigned getVBTableIndex(const CXXRecordDecl *Derived, const CXXRecordDecl *VBase)
Returns the index of VBase in the vbtable of Derived.
unsigned getEffectiveCallingConvention() const
getEffectiveCallingConvention - Return the actual calling convention to use, which may depend on the ...
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:141
static llvm::FunctionCallee getInitThreadHeaderFn(CodeGenModule &CGM)
Encodes a location in the source.
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
bool isMemberDataPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2834
Address CreateConstInBoundsGEP2_32(Address Addr, unsigned Idx0, unsigned Idx1, const llvm::Twine &Name="")
Definition: CGBuilder.h:258
static bool Ret(InterpState &S, CodePtr &PC, APValue &Result)
Definition: Interp.cpp:34
CastKind getCastKind() const
Definition: Expr.h:3171
RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee, ReturnValueSlot ReturnValue, const CallArgList &Args, llvm::CallBase **callOrInvoke, SourceLocation Loc)
EmitCall - Generate a call of the given function, expecting the given result type, and using the given argument list which specifies both the LLVM arguments and the types they were derived from.
Definition: CGCall.cpp:3779
Represents a new-expression for memory allocation and constructor calls, e.g: "new CXXNewExpr(foo)"...
Definition: ExprCXX.h:2009
Represents a call to a member function that may be written either with member call syntax (e...
Definition: ExprCXX.h:170
ASTContext & getASTContext() const LLVM_READONLY
Definition: DeclBase.cpp:377
static bool IsSizeGreaterThan128(const CXXRecordDecl *RD)
const Decl * getDecl() const
Definition: GlobalDecl.h:77
Represents a single component in a vtable.
Definition: VTableBuilder.h:29
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:43
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1892
const VTableLayout & getVFTableLayout(const CXXRecordDecl *RD, CharUnits VFPtrOffset)
QualType getAllocatedType() const
Definition: ExprCXX.h:2102
llvm::Constant * GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH=false)
Get the address of the RTTI descriptor for the given type.
void createVTableInitializer(ConstantStructBuilder &builder, const VTableLayout &layout, llvm::Constant *rtti)
Add vtable components for the given vtable layout to the given global initializer.
Definition: CGVTables.cpp:739
const CXXRecordDecl * ObjectWithVPtr
This is the most derived class that has this vptr at offset zero.
An aligned address.
Definition: Address.h:24
void StartFunction(GlobalDecl GD, QualType RetTy, llvm::Function *Fn, const CGFunctionInfo &FnInfo, const FunctionArgList &Args, SourceLocation Loc=SourceLocation(), SourceLocation StartLoc=SourceLocation())
Emit code for the start of a function.
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1160
unsigned getCustomDiagID(Level L, const char(&FormatString)[N])
Return an ID for a diagnostic with the specified format string and level.
Definition: Diagnostic.h:776
All available information about a concrete callee.
Definition: CGCall.h:66
bool canPassInRegisters() const
Determine whether this class can be passed in registers.
Definition: Decl.h:3812
MangleContext & getMangleContext()
Gets the mangle context.
Definition: CGCXXABI.h:96
Complete object dtor.
Definition: ABI.h:35
llvm::Instruction * CurrentFuncletPad
constexpr XRayInstrMask None
Definition: XRayInstr.h:37
CGCXXABI * CreateMicrosoftCXXABI(CodeGenModule &CGM)
Creates a Microsoft-family ABI.
static void mangleVFTableName(MicrosoftMangleContext &MangleContext, const CXXRecordDecl *RD, const VPtrInfo &VFPtr, SmallString< 256 > &Name)
bool isMemberPointerToDerivedMember() const
Definition: APValue.cpp:805
The MS C++ ABI needs a pointer to RTTI data plus some flags to describe the type of a catch handler...
Definition: CGCleanup.h:37
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
CXXCtorType
C++ constructor types.
Definition: ABI.h:24
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:221
void addUsedGlobal(llvm::GlobalValue *GV)
Add a global to a list to be added to the llvm.used metadata.
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:358
llvm::Value * getScalarVal() const
getScalarVal() - Return the Value* of this scalar value.
Definition: CGValue.h:58
CXXRecordDecl * getMostRecentCXXRecordDecl() const
Definition: Type.cpp:4149
bool isVirtuallyDerivedFrom(const CXXRecordDecl *Base) const
Determine whether this class is virtually derived from the class Base.
void ErrorUnsupported(const Stmt *S, const char *Type)
Print out an error that codegen doesn&#39;t support the specified stmt yet.
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
CharUnits alignmentAtOffset(CharUnits offset) const
Given that this is a non-zero alignment value, what is the alignment at the given offset...
Definition: CharUnits.h:194
llvm::GlobalValue * GetGlobalValue(StringRef Ref)
Dataflow Directional Tag Classes.
External linkage within a unique namespace.
Definition: Linkage.h:40
static bool isDeletingDtor(GlobalDecl GD)
uint64_t Index
Method&#39;s index in the vftable.
Represents a delete expression for memory deallocation and destructor calls, e.g. ...
Definition: ExprCXX.h:2268
const VPtrInfoVector & enumerateVBTables(const CXXRecordDecl *RD)
llvm::LoadInst * CreateAlignedLoad(llvm::Value *Addr, CharUnits Align, const llvm::Twine &Name="")
Definition: CGBuilder.h:90
llvm::Constant * getPointer() const
Definition: Address.h:83
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:69
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2015
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:2804
CharUnits NonVirtualOffset
IntroducingObject is at this offset from its containing complete object or virtual base...
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:107
llvm::Module & getModule() const
void maybeSetTrivialComdat(const Decl &D, llvm::GlobalObject &GO)
CharUnits getVBaseAlignment(CharUnits DerivedAlign, const CXXRecordDecl *Derived, const CXXRecordDecl *VBase)
Returns the assumed alignment of a virtual base of a class.
Definition: CGClass.cpp:55
ArrayRef< const CXXRecordDecl * > getMemberPointerPath() const
Definition: APValue.cpp:812
llvm::Function * createAtExitStub(const VarDecl &VD, llvm::FunctionCallee Dtor, llvm::Constant *Addr)
Create a stub function, suitable for being passed to atexit, which passes the given address to the gi...
Definition: CGDeclCXX.cpp:228
union clang::ThisAdjustment::VirtualAdjustment Virtual
bool hasNonTrivialCopyAssignment() const
Determine whether this class has a non-trivial copy assignment operator (C++ [class.copy]p11, C++11 [class.copy]p25)
Definition: DeclCXX.h:1235
path_iterator path_end()
Definition: Expr.h:3198
void EmitAutoVarCleanups(const AutoVarEmission &emission)
Definition: CGDecl.cpp:1976
void EmitNoreturnRuntimeCallOrInvoke(llvm::FunctionCallee callee, ArrayRef< llvm::Value *> args)
Emits a call or invoke to the given noreturn runtime function.
Definition: CGCall.cpp:3708
void AppendLinkerOptions(StringRef Opts)
Appends Opts to the "llvm.linker.options" metadata value.
static llvm::GlobalVariable * getTypeInfoVTable(CodeGenModule &CGM)
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
const CXXRecordDecl * getVBaseWithVPtr() const
The vptr is stored inside the non-virtual component of this virtual base.
Implements C++ ABI-specific code generation functions.
Definition: CGCXXABI.h:43
This class organizes the cross-module state that is used while lowering AST types to LLVM types...
Definition: CodeGenTypes.h:59
bool isStaticLocal() const
Returns true if a variable with function scope is a static local variable.
Definition: Decl.h:1074
llvm::Constant * GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty=nullptr, bool ForVTable=false, bool DontDefer=false, ForDefinition_t IsForDefinition=NotForDefinition)
Return the address of the given function.
StringRef getMangledName(GlobalDecl GD)
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:31
llvm::FunctionCallee CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeList ExtraAttrs=llvm::AttributeList(), bool Local=false)
Create or return a runtime function declaration with the specified type and name. ...
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:461
APValue - This class implements a discriminated union of [uninitialized] [APSInt] [APFloat]...
Definition: APValue.h:115
Represents a base class of a C++ class.
Definition: DeclCXX.h:147
bool isObjectType() const
Determine whether this type is an object type.
Definition: Type.h:1906
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2088
static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT, CGCXXABI &CXXABI)
Definition: TargetInfo.cpp:139
const Decl * CurFuncDecl
CurFuncDecl - Holds the Decl for the current outermost non-closure context.
uint64_t getFieldOffset(const ValueDecl *FD) const
Get the offset of a FieldDecl or IndirectFieldDecl, in bits.
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
static bool isInstanceMethod(const Decl *D)
QualType getUnqualifiedType() const
Retrieve the unqualified variant of the given type, removing as little sugar as possible.
Definition: Type.h:6228
Address CreateConstByteGEP(Address Addr, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:250
bool hasUnaligned() const
Definition: Type.h:293
Represents a C++ struct/union/class.
Definition: DeclCXX.h:255
bool isMemberFunctionPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2828
llvm::Function * CreateGlobalInitOrDestructFunction(llvm::FunctionType *ty, const Twine &name, const CGFunctionInfo &FI, SourceLocation Loc=SourceLocation(), bool TLS=false)
Definition: CGDeclCXX.cpp:334
CXXCatchStmt - This represents a C++ catch block.
Definition: StmtCXX.h:28
llvm::Type * ConvertType(QualType T)
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:6175
A specialization of Address that requires the address to be an LLVM Constant.
Definition: Address.h:74
int32_t VtordispOffset
The offset of the vtordisp (in bytes), relative to the ECX.
Definition: ABI.h:124
Address ReturnValue
ReturnValue - The temporary alloca to hold the return value.
No linkage according to the standard, but is visible from other translation units because of types de...
Definition: Linkage.h:44
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
static CGCallee forVirtual(const CallExpr *CE, GlobalDecl MD, Address Addr, llvm::FunctionType *FTy)
Definition: CGCall.h:144
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:262
llvm::DenseMap< const CXXRecordDecl *, VBaseInfo > VBaseOffsetsMapTy
Definition: RecordLayout.h:59
bool isGlobalDelete() const
Definition: ExprCXX.h:2294
Copying closure variant of a ctor.
Definition: ABI.h:28
CharUnits computeNonVirtualBaseClassOffset(const CXXRecordDecl *DerivedClass, CastExpr::path_const_iterator Start, CastExpr::path_const_iterator End)
Definition: CGClass.cpp:149
CharUnits FullOffsetInMDC
Static offset from the top of the most derived class to this vfptr, including any virtual base offset...
const CGFunctionInfo & arrangeMSCtorClosure(const CXXConstructorDecl *CD, CXXCtorType CT)
Definition: CGCall.cpp:539
CanQualType IntTy
Definition: ASTContext.h:1024
Struct with all information about dynamic [sub]class needed to set vptr.
void initialize(TemplateInstantiationCallbackPtrs &Callbacks, const Sema &TheSema)
struct clang::ReturnAdjustment::VirtualAdjustment::@133 Microsoft
llvm::Function * codegenCXXStructor(GlobalDecl GD)
Definition: CGCXX.cpp:206
MethodVFTableLocation getMethodVFTableLocation(GlobalDecl GD)
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
GVALinkage
A more specific kind of linkage than enum Linkage.
Definition: Linkage.h:73
Holds information about the inheritance path to a virtual base or function table pointer.
bool isPointerType() const
Definition: Type.h:6391
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Set the IRBuilder to not attach debug locations.
Definition: CGDebugInfo.h:759
llvm::StoreInst * CreateAlignedStore(llvm::Value *Val, llvm::Value *Addr, CharUnits Align, bool IsVolatile=false)
Definition: CGBuilder.h:114
QualType getType() const
Definition: Decl.h:655
uint32_t VBIndex
Index of the virtual base in the vbtable.
Definition: ABI.h:63
LValue - This represents an lvalue references.
Definition: CGValue.h:166
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:146
This represents a decl that may have a name.
Definition: Decl.h:248
void EmitMustTailThunk(GlobalDecl GD, llvm::Value *AdjustedThisPtr, llvm::FunctionCallee Callee)
Emit a musttail call for a thunk with a potentially adjusted this pointer.
Definition: CGVTables.cpp:389
BasePath PathToIntroducingObject
This holds the base classes path from the complete type to the first base with the given vfptr offset...
const CXXConstructorDecl * getCopyConstructorForExceptionObject(CXXRecordDecl *RD)
bool CurFuncIsThunk
In C++, whether we are code generating a thunk.
Notes how many arguments were added to the beginning (Prefix) and ending (Suffix) of an arg list...
Definition: CGCXXABI.h:295
RecordArgABI
Specify how one should pass an argument of a record type.
Definition: CGCXXABI.h:125
llvm::CallInst * EmitNounwindRuntimeCall(llvm::FunctionCallee callee, const Twine &name="")
llvm::CallBase * EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee, ArrayRef< llvm::Value *> args, const Twine &name="")
Emits a call or invoke instruction to the given runtime function.
Definition: CGCall.cpp:3739
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3176
ctor_range ctors() const
Definition: DeclCXX.h:648
struct clang::ThisAdjustment::VirtualAdjustment::@135 Microsoft
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:262
int32_t VBPtrOffset
The offset of the vbptr of the derived class (in bytes), relative to the ECX after vtordisp adjustmen...
Definition: ABI.h:128
void PopCleanupBlock(bool FallThroughIsBranchThrough=false)
PopCleanupBlock - Will pop the cleanup entry on the stack and process all branch fixups.
Definition: CGCleanup.cpp:644
static void serializeClassHierarchy(SmallVectorImpl< MSRTTIClass > &Classes, const CXXRecordDecl *RD)
Recursively serializes a class hierarchy in pre-order depth first order.
base_class_range vbases()
Definition: DeclCXX.h:603
static ABIArgInfo getIndirect(CharUnits Alignment, bool ByVal=true, bool Realign=false, llvm::Type *Padding=nullptr)
llvm::Value * EmitVTableTypeCheckedLoad(const CXXRecordDecl *RD, llvm::Value *VTable, uint64_t VTableByteOffset)
Emit a type checked load from the given vtable.
Definition: CGClass.cpp:2797
SourceLocation getLocation() const
Definition: DeclBase.h:429
QualType getPointeeType() const
Definition: Type.h:2824
bool isExternallyVisible() const
Definition: Decl.h:387
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
CanQualType getSizeType() const
Return the unique type for "size_t" (C99 7.17), defined in <stddef.h>.
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1541
bool isNoDestroy(const ASTContext &) const
Is destruction of this variable entirely suppressed? If so, the variable need not have a usable destr...
Definition: Decl.cpp:2589