clang  10.0.0git
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"
22 #include "clang/AST/Attr.h"
24 #include "clang/AST/Decl.h"
25 #include "clang/AST/DeclCXX.h"
26 #include "clang/AST/StmtCXX.h"
29 #include "llvm/ADT/StringExtras.h"
30 #include "llvm/ADT/StringSet.h"
31 #include "llvm/IR/Intrinsics.h"
32 
33 using namespace clang;
34 using namespace CodeGen;
35 
36 namespace {
37 
38 /// Holds all the vbtable globals for a given class.
39 struct VBTableGlobals {
40  const VPtrInfoVector *VBTables;
42 };
43 
44 class MicrosoftCXXABI : public CGCXXABI {
45 public:
46  MicrosoftCXXABI(CodeGenModule &CGM)
47  : CGCXXABI(CGM), BaseClassDescriptorType(nullptr),
48  ClassHierarchyDescriptorType(nullptr),
49  CompleteObjectLocatorType(nullptr), CatchableTypeType(nullptr),
50  ThrowInfoType(nullptr) {}
51 
52  bool HasThisReturn(GlobalDecl GD) const override;
53  bool hasMostDerivedReturn(GlobalDecl GD) const override;
54 
55  bool classifyReturnType(CGFunctionInfo &FI) const override;
56 
57  RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override;
58 
59  bool isSRetParameterAfterThis() const override { return true; }
60 
61  bool isThisCompleteObject(GlobalDecl GD) const override {
62  // The Microsoft ABI doesn't use separate complete-object vs.
63  // base-object variants of constructors, but it does of destructors.
64  if (isa<CXXDestructorDecl>(GD.getDecl())) {
65  switch (GD.getDtorType()) {
66  case Dtor_Complete:
67  case Dtor_Deleting:
68  return true;
69 
70  case Dtor_Base:
71  return false;
72 
73  case Dtor_Comdat: llvm_unreachable("emitting dtor comdat as function?");
74  }
75  llvm_unreachable("bad dtor kind");
76  }
77 
78  // No other kinds.
79  return false;
80  }
81 
82  size_t getSrcArgforCopyCtor(const CXXConstructorDecl *CD,
83  FunctionArgList &Args) const override {
84  assert(Args.size() >= 2 &&
85  "expected the arglist to have at least two args!");
86  // The 'most_derived' parameter goes second if the ctor is variadic and
87  // has v-bases.
88  if (CD->getParent()->getNumVBases() > 0 &&
89  CD->getType()->castAs<FunctionProtoType>()->isVariadic())
90  return 2;
91  return 1;
92  }
93 
94  std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD) override {
95  std::vector<CharUnits> VBPtrOffsets;
96  const ASTContext &Context = getContext();
97  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
98 
99  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
100  for (const std::unique_ptr<VPtrInfo> &VBT : *VBGlobals.VBTables) {
101  const ASTRecordLayout &SubobjectLayout =
102  Context.getASTRecordLayout(VBT->IntroducingObject);
103  CharUnits Offs = VBT->NonVirtualOffset;
104  Offs += SubobjectLayout.getVBPtrOffset();
105  if (VBT->getVBaseWithVPtr())
106  Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
107  VBPtrOffsets.push_back(Offs);
108  }
109  llvm::array_pod_sort(VBPtrOffsets.begin(), VBPtrOffsets.end());
110  return VBPtrOffsets;
111  }
112 
113  StringRef GetPureVirtualCallName() override { return "_purecall"; }
114  StringRef GetDeletedVirtualCallName() override { return "_purecall"; }
115 
116  void emitVirtualObjectDelete(CodeGenFunction &CGF, const CXXDeleteExpr *DE,
117  Address Ptr, QualType ElementType,
118  const CXXDestructorDecl *Dtor) override;
119 
120  void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) override;
121  void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) override;
122 
123  void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) override;
124 
125  llvm::GlobalVariable *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
126  const VPtrInfo &Info);
127 
128  llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
130  getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) override;
131 
132  /// MSVC needs an extra flag to indicate a catchall.
133  CatchTypeInfo getCatchAllTypeInfo() override {
134  return CatchTypeInfo{nullptr, 0x40};
135  }
136 
137  bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
138  void EmitBadTypeidCall(CodeGenFunction &CGF) override;
139  llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
140  Address ThisPtr,
141  llvm::Type *StdTypeInfoPtrTy) override;
142 
143  bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
144  QualType SrcRecordTy) override;
145 
146  llvm::Value *EmitDynamicCastCall(CodeGenFunction &CGF, Address Value,
147  QualType SrcRecordTy, QualType DestTy,
148  QualType DestRecordTy,
149  llvm::BasicBlock *CastEnd) override;
150 
151  llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
152  QualType SrcRecordTy,
153  QualType DestTy) override;
154 
155  bool EmitBadCastCall(CodeGenFunction &CGF) override;
156  bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override {
157  return false;
158  }
159 
160  llvm::Value *
161  GetVirtualBaseClassOffset(CodeGenFunction &CGF, Address This,
162  const CXXRecordDecl *ClassDecl,
163  const CXXRecordDecl *BaseClassDecl) override;
164 
165  llvm::BasicBlock *
166  EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
167  const CXXRecordDecl *RD) override;
168 
169  llvm::BasicBlock *
170  EmitDtorCompleteObjectHandler(CodeGenFunction &CGF);
171 
172  void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
173  const CXXRecordDecl *RD) override;
174 
175  void EmitCXXConstructors(const CXXConstructorDecl *D) override;
176 
177  // Background on MSVC destructors
178  // ==============================
179  //
180  // Both Itanium and MSVC ABIs have destructor variants. The variant names
181  // roughly correspond in the following way:
182  // Itanium Microsoft
183  // Base -> no name, just ~Class
184  // Complete -> vbase destructor
185  // Deleting -> scalar deleting destructor
186  // vector deleting destructor
187  //
188  // The base and complete destructors are the same as in Itanium, although the
189  // complete destructor does not accept a VTT parameter when there are virtual
190  // bases. A separate mechanism involving vtordisps is used to ensure that
191  // virtual methods of destroyed subobjects are not called.
192  //
193  // The deleting destructors accept an i32 bitfield as a second parameter. Bit
194  // 1 indicates if the memory should be deleted. Bit 2 indicates if the this
195  // pointer points to an array. The scalar deleting destructor assumes that
196  // bit 2 is zero, and therefore does not contain a loop.
197  //
198  // For virtual destructors, only one entry is reserved in the vftable, and it
199  // always points to the vector deleting destructor. The vector deleting
200  // destructor is the most general, so it can be used to destroy objects in
201  // place, delete single heap objects, or delete arrays.
202  //
203  // A TU defining a non-inline destructor is only guaranteed to emit a base
204  // destructor, and all of the other variants are emitted on an as-needed basis
205  // in COMDATs. Because a non-base destructor can be emitted in a TU that
206  // lacks a definition for the destructor, non-base destructors must always
207  // delegate to or alias the base destructor.
208 
209  AddedStructorArgs
210  buildStructorSignature(GlobalDecl GD,
211  SmallVectorImpl<CanQualType> &ArgTys) override;
212 
213  /// Non-base dtors should be emitted as delegating thunks in this ABI.
214  bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
215  CXXDtorType DT) const override {
216  return DT != Dtor_Base;
217  }
218 
219  void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
220  const CXXDestructorDecl *Dtor,
221  CXXDtorType DT) const override;
222 
223  llvm::GlobalValue::LinkageTypes
224  getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
225  CXXDtorType DT) const override;
226 
227  void EmitCXXDestructors(const CXXDestructorDecl *D) override;
228 
229  const CXXRecordDecl *
230  getThisArgumentTypeForMethod(const CXXMethodDecl *MD) override {
231  if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
233  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD);
234  // The vbases might be ordered differently in the final overrider object
235  // and the complete object, so the "this" argument may sometimes point to
236  // memory that has no particular type (e.g. past the complete object).
237  // In this case, we just use a generic pointer type.
238  // FIXME: might want to have a more precise type in the non-virtual
239  // multiple inheritance case.
240  if (ML.VBase || !ML.VFPtrOffset.isZero())
241  return nullptr;
242  }
243  return MD->getParent();
244  }
245 
246  Address
247  adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
248  Address This,
249  bool VirtualCall) override;
250 
251  void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
252  FunctionArgList &Params) override;
253 
254  void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override;
255 
256  AddedStructorArgs
257  addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
258  CXXCtorType Type, bool ForVirtualBase,
259  bool Delegating, CallArgList &Args) override;
260 
261  void EmitDestructorCall(CodeGenFunction &CGF, const CXXDestructorDecl *DD,
262  CXXDtorType Type, bool ForVirtualBase,
263  bool Delegating, Address This,
264  QualType ThisTy) override;
265 
266  void emitVTableTypeMetadata(const VPtrInfo &Info, const CXXRecordDecl *RD,
267  llvm::GlobalVariable *VTable);
268 
269  void emitVTableDefinitions(CodeGenVTables &CGVT,
270  const CXXRecordDecl *RD) override;
271 
272  bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
273  CodeGenFunction::VPtr Vptr) override;
274 
275  /// Don't initialize vptrs if dynamic class
276  /// is marked with with the 'novtable' attribute.
277  bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
278  return !VTableClass->hasAttr<MSNoVTableAttr>();
279  }
280 
281  llvm::Constant *
282  getVTableAddressPoint(BaseSubobject Base,
283  const CXXRecordDecl *VTableClass) override;
284 
285  llvm::Value *getVTableAddressPointInStructor(
286  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
287  BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
288 
289  llvm::Constant *
290  getVTableAddressPointForConstExpr(BaseSubobject Base,
291  const CXXRecordDecl *VTableClass) override;
292 
293  llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
294  CharUnits VPtrOffset) override;
295 
296  CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
297  Address This, llvm::Type *Ty,
298  SourceLocation Loc) override;
299 
300  llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
301  const CXXDestructorDecl *Dtor,
302  CXXDtorType DtorType, Address This,
303  DeleteOrMemberCallExpr E) override;
304 
305  void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
306  CallArgList &CallArgs) override {
307  assert(GD.getDtorType() == Dtor_Deleting &&
308  "Only deleting destructor thunks are available in this ABI");
309  CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
310  getContext().IntTy);
311  }
312 
313  void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
314 
315  llvm::GlobalVariable *
316  getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
317  llvm::GlobalVariable::LinkageTypes Linkage);
318 
319  llvm::GlobalVariable *
320  getAddrOfVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
321  const CXXRecordDecl *DstRD) {
322  SmallString<256> OutName;
323  llvm::raw_svector_ostream Out(OutName);
324  getMangleContext().mangleCXXVirtualDisplacementMap(SrcRD, DstRD, Out);
325  StringRef MangledName = OutName.str();
326 
327  if (auto *VDispMap = CGM.getModule().getNamedGlobal(MangledName))
328  return VDispMap;
329 
330  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
331  unsigned NumEntries = 1 + SrcRD->getNumVBases();
332  SmallVector<llvm::Constant *, 4> Map(NumEntries,
333  llvm::UndefValue::get(CGM.IntTy));
334  Map[0] = llvm::ConstantInt::get(CGM.IntTy, 0);
335  bool AnyDifferent = false;
336  for (const auto &I : SrcRD->vbases()) {
337  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
338  if (!DstRD->isVirtuallyDerivedFrom(VBase))
339  continue;
340 
341  unsigned SrcVBIndex = VTContext.getVBTableIndex(SrcRD, VBase);
342  unsigned DstVBIndex = VTContext.getVBTableIndex(DstRD, VBase);
343  Map[SrcVBIndex] = llvm::ConstantInt::get(CGM.IntTy, DstVBIndex * 4);
344  AnyDifferent |= SrcVBIndex != DstVBIndex;
345  }
346  // This map would be useless, don't use it.
347  if (!AnyDifferent)
348  return nullptr;
349 
350  llvm::ArrayType *VDispMapTy = llvm::ArrayType::get(CGM.IntTy, Map.size());
351  llvm::Constant *Init = llvm::ConstantArray::get(VDispMapTy, Map);
352  llvm::GlobalValue::LinkageTypes Linkage =
353  SrcRD->isExternallyVisible() && DstRD->isExternallyVisible()
354  ? llvm::GlobalValue::LinkOnceODRLinkage
356  auto *VDispMap = new llvm::GlobalVariable(
357  CGM.getModule(), VDispMapTy, /*isConstant=*/true, Linkage,
358  /*Initializer=*/Init, MangledName);
359  return VDispMap;
360  }
361 
362  void emitVBTableDefinition(const VPtrInfo &VBT, const CXXRecordDecl *RD,
363  llvm::GlobalVariable *GV) const;
364 
365  void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
366  GlobalDecl GD, bool ReturnAdjustment) override {
367  GVALinkage Linkage =
368  getContext().GetGVALinkageForFunction(cast<FunctionDecl>(GD.getDecl()));
369 
370  if (Linkage == GVA_Internal)
371  Thunk->setLinkage(llvm::GlobalValue::InternalLinkage);
372  else if (ReturnAdjustment)
373  Thunk->setLinkage(llvm::GlobalValue::WeakODRLinkage);
374  else
375  Thunk->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
376  }
377 
378  bool exportThunk() override { return false; }
379 
380  llvm::Value *performThisAdjustment(CodeGenFunction &CGF, Address This,
381  const ThisAdjustment &TA) override;
382 
383  llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
384  const ReturnAdjustment &RA) override;
385 
386  void EmitThreadLocalInitFuncs(
387  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
388  ArrayRef<llvm::Function *> CXXThreadLocalInits,
389  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) override;
390 
391  bool usesThreadWrapperFunction(const VarDecl *VD) const override {
392  return false;
393  }
394  LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF, const VarDecl *VD,
395  QualType LValType) override;
396 
397  void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
398  llvm::GlobalVariable *DeclPtr,
399  bool PerformInit) override;
400  void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
401  llvm::FunctionCallee Dtor,
402  llvm::Constant *Addr) override;
403 
404  // ==== Notes on array cookies =========
405  //
406  // MSVC seems to only use cookies when the class has a destructor; a
407  // two-argument usual array deallocation function isn't sufficient.
408  //
409  // For example, this code prints "100" and "1":
410  // struct A {
411  // char x;
412  // void *operator new[](size_t sz) {
413  // printf("%u\n", sz);
414  // return malloc(sz);
415  // }
416  // void operator delete[](void *p, size_t sz) {
417  // printf("%u\n", sz);
418  // free(p);
419  // }
420  // };
421  // int main() {
422  // A *p = new A[100];
423  // delete[] p;
424  // }
425  // Whereas it prints "104" and "104" if you give A a destructor.
426 
427  bool requiresArrayCookie(const CXXDeleteExpr *expr,
428  QualType elementType) override;
429  bool requiresArrayCookie(const CXXNewExpr *expr) override;
430  CharUnits getArrayCookieSizeImpl(QualType type) override;
431  Address InitializeArrayCookie(CodeGenFunction &CGF,
432  Address NewPtr,
433  llvm::Value *NumElements,
434  const CXXNewExpr *expr,
435  QualType ElementType) override;
436  llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
437  Address allocPtr,
438  CharUnits cookieSize) override;
439 
440  friend struct MSRTTIBuilder;
441 
442  bool isImageRelative() const {
443  return CGM.getTarget().getPointerWidth(/*AddrSpace=*/0) == 64;
444  }
445 
446  // 5 routines for constructing the llvm types for MS RTTI structs.
447  llvm::StructType *getTypeDescriptorType(StringRef TypeInfoString) {
448  llvm::SmallString<32> TDTypeName("rtti.TypeDescriptor");
449  TDTypeName += llvm::utostr(TypeInfoString.size());
450  llvm::StructType *&TypeDescriptorType =
451  TypeDescriptorTypeMap[TypeInfoString.size()];
452  if (TypeDescriptorType)
453  return TypeDescriptorType;
454  llvm::Type *FieldTypes[] = {
455  CGM.Int8PtrPtrTy,
456  CGM.Int8PtrTy,
457  llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
458  TypeDescriptorType =
459  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
460  return TypeDescriptorType;
461  }
462 
463  llvm::Type *getImageRelativeType(llvm::Type *PtrType) {
464  if (!isImageRelative())
465  return PtrType;
466  return CGM.IntTy;
467  }
468 
469  llvm::StructType *getBaseClassDescriptorType() {
470  if (BaseClassDescriptorType)
471  return BaseClassDescriptorType;
472  llvm::Type *FieldTypes[] = {
473  getImageRelativeType(CGM.Int8PtrTy),
474  CGM.IntTy,
475  CGM.IntTy,
476  CGM.IntTy,
477  CGM.IntTy,
478  CGM.IntTy,
479  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
480  };
481  BaseClassDescriptorType = llvm::StructType::create(
482  CGM.getLLVMContext(), FieldTypes, "rtti.BaseClassDescriptor");
483  return BaseClassDescriptorType;
484  }
485 
486  llvm::StructType *getClassHierarchyDescriptorType() {
487  if (ClassHierarchyDescriptorType)
488  return ClassHierarchyDescriptorType;
489  // Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
490  ClassHierarchyDescriptorType = llvm::StructType::create(
491  CGM.getLLVMContext(), "rtti.ClassHierarchyDescriptor");
492  llvm::Type *FieldTypes[] = {
493  CGM.IntTy,
494  CGM.IntTy,
495  CGM.IntTy,
496  getImageRelativeType(
497  getBaseClassDescriptorType()->getPointerTo()->getPointerTo()),
498  };
499  ClassHierarchyDescriptorType->setBody(FieldTypes);
500  return ClassHierarchyDescriptorType;
501  }
502 
503  llvm::StructType *getCompleteObjectLocatorType() {
504  if (CompleteObjectLocatorType)
505  return CompleteObjectLocatorType;
506  CompleteObjectLocatorType = llvm::StructType::create(
507  CGM.getLLVMContext(), "rtti.CompleteObjectLocator");
508  llvm::Type *FieldTypes[] = {
509  CGM.IntTy,
510  CGM.IntTy,
511  CGM.IntTy,
512  getImageRelativeType(CGM.Int8PtrTy),
513  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
514  getImageRelativeType(CompleteObjectLocatorType),
515  };
516  llvm::ArrayRef<llvm::Type *> FieldTypesRef(FieldTypes);
517  if (!isImageRelative())
518  FieldTypesRef = FieldTypesRef.drop_back();
519  CompleteObjectLocatorType->setBody(FieldTypesRef);
520  return CompleteObjectLocatorType;
521  }
522 
523  llvm::GlobalVariable *getImageBase() {
524  StringRef Name = "__ImageBase";
525  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
526  return GV;
527 
528  auto *GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
529  /*isConstant=*/true,
531  /*Initializer=*/nullptr, Name);
532  CGM.setDSOLocal(GV);
533  return GV;
534  }
535 
536  llvm::Constant *getImageRelativeConstant(llvm::Constant *PtrVal) {
537  if (!isImageRelative())
538  return PtrVal;
539 
540  if (PtrVal->isNullValue())
541  return llvm::Constant::getNullValue(CGM.IntTy);
542 
543  llvm::Constant *ImageBaseAsInt =
544  llvm::ConstantExpr::getPtrToInt(getImageBase(), CGM.IntPtrTy);
545  llvm::Constant *PtrValAsInt =
546  llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
547  llvm::Constant *Diff =
548  llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
549  /*HasNUW=*/true, /*HasNSW=*/true);
550  return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
551  }
552 
553 private:
554  MicrosoftMangleContext &getMangleContext() {
555  return cast<MicrosoftMangleContext>(CodeGen::CGCXXABI::getMangleContext());
556  }
557 
558  llvm::Constant *getZeroInt() {
559  return llvm::ConstantInt::get(CGM.IntTy, 0);
560  }
561 
562  llvm::Constant *getAllOnesInt() {
563  return llvm::Constant::getAllOnesValue(CGM.IntTy);
564  }
565 
566  CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) override;
567 
568  void
569  GetNullMemberPointerFields(const MemberPointerType *MPT,
571 
572  /// Shared code for virtual base adjustment. Returns the offset from
573  /// the vbptr to the virtual base. Optionally returns the address of the
574  /// vbptr itself.
575  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
576  Address Base,
577  llvm::Value *VBPtrOffset,
578  llvm::Value *VBTableOffset,
579  llvm::Value **VBPtr = nullptr);
580 
581  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
582  Address Base,
583  int32_t VBPtrOffset,
584  int32_t VBTableOffset,
585  llvm::Value **VBPtr = nullptr) {
586  assert(VBTableOffset % 4 == 0 && "should be byte offset into table of i32s");
587  llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
588  *VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset);
589  return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr);
590  }
591 
592  std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
593  performBaseAdjustment(CodeGenFunction &CGF, Address Value,
594  QualType SrcRecordTy);
595 
596  /// Performs a full virtual base adjustment. Used to dereference
597  /// pointers to members of virtual bases.
598  llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const Expr *E,
599  const CXXRecordDecl *RD, Address Base,
600  llvm::Value *VirtualBaseAdjustmentOffset,
601  llvm::Value *VBPtrOffset /* optional */);
602 
603  /// Emits a full member pointer with the fields common to data and
604  /// function member pointers.
605  llvm::Constant *EmitFullMemberPointer(llvm::Constant *FirstField,
606  bool IsMemberFunction,
607  const CXXRecordDecl *RD,
608  CharUnits NonVirtualBaseAdjustment,
609  unsigned VBTableIndex);
610 
611  bool MemberPointerConstantIsNull(const MemberPointerType *MPT,
612  llvm::Constant *MP);
613 
614  /// - Initialize all vbptrs of 'this' with RD as the complete type.
615  void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD);
616 
617  /// Caching wrapper around VBTableBuilder::enumerateVBTables().
618  const VBTableGlobals &enumerateVBTables(const CXXRecordDecl *RD);
619 
620  /// Generate a thunk for calling a virtual member function MD.
621  llvm::Function *EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
622  const MethodVFTableLocation &ML);
623 
624  llvm::Constant *EmitMemberDataPointer(const CXXRecordDecl *RD,
625  CharUnits offset);
626 
627 public:
628  llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
629 
630  bool isZeroInitializable(const MemberPointerType *MPT) override;
631 
632  bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
633  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
634  return RD->hasAttr<MSInheritanceAttr>();
635  }
636 
637  llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
638 
639  llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
640  CharUnits offset) override;
641  llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
642  llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
643 
644  llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
645  llvm::Value *L,
646  llvm::Value *R,
647  const MemberPointerType *MPT,
648  bool Inequality) override;
649 
650  llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
651  llvm::Value *MemPtr,
652  const MemberPointerType *MPT) override;
653 
654  llvm::Value *
655  EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
656  Address Base, llvm::Value *MemPtr,
657  const MemberPointerType *MPT) override;
658 
659  llvm::Value *EmitNonNullMemberPointerConversion(
660  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
663  CGBuilderTy &Builder);
664 
665  llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
666  const CastExpr *E,
667  llvm::Value *Src) override;
668 
669  llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
670  llvm::Constant *Src) override;
671 
672  llvm::Constant *EmitMemberPointerConversion(
673  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
675  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src);
676 
677  CGCallee
678  EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, const Expr *E,
679  Address This, llvm::Value *&ThisPtrForCall,
680  llvm::Value *MemPtr,
681  const MemberPointerType *MPT) override;
682 
683  void emitCXXStructor(GlobalDecl GD) override;
684 
685  llvm::StructType *getCatchableTypeType() {
686  if (CatchableTypeType)
687  return CatchableTypeType;
688  llvm::Type *FieldTypes[] = {
689  CGM.IntTy, // Flags
690  getImageRelativeType(CGM.Int8PtrTy), // TypeDescriptor
691  CGM.IntTy, // NonVirtualAdjustment
692  CGM.IntTy, // OffsetToVBPtr
693  CGM.IntTy, // VBTableIndex
694  CGM.IntTy, // Size
695  getImageRelativeType(CGM.Int8PtrTy) // CopyCtor
696  };
697  CatchableTypeType = llvm::StructType::create(
698  CGM.getLLVMContext(), FieldTypes, "eh.CatchableType");
699  return CatchableTypeType;
700  }
701 
702  llvm::StructType *getCatchableTypeArrayType(uint32_t NumEntries) {
703  llvm::StructType *&CatchableTypeArrayType =
704  CatchableTypeArrayTypeMap[NumEntries];
705  if (CatchableTypeArrayType)
706  return CatchableTypeArrayType;
707 
708  llvm::SmallString<23> CTATypeName("eh.CatchableTypeArray.");
709  CTATypeName += llvm::utostr(NumEntries);
710  llvm::Type *CTType =
711  getImageRelativeType(getCatchableTypeType()->getPointerTo());
712  llvm::Type *FieldTypes[] = {
713  CGM.IntTy, // NumEntries
714  llvm::ArrayType::get(CTType, NumEntries) // CatchableTypes
715  };
716  CatchableTypeArrayType =
717  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, CTATypeName);
718  return CatchableTypeArrayType;
719  }
720 
721  llvm::StructType *getThrowInfoType() {
722  if (ThrowInfoType)
723  return ThrowInfoType;
724  llvm::Type *FieldTypes[] = {
725  CGM.IntTy, // Flags
726  getImageRelativeType(CGM.Int8PtrTy), // CleanupFn
727  getImageRelativeType(CGM.Int8PtrTy), // ForwardCompat
728  getImageRelativeType(CGM.Int8PtrTy) // CatchableTypeArray
729  };
730  ThrowInfoType = llvm::StructType::create(CGM.getLLVMContext(), FieldTypes,
731  "eh.ThrowInfo");
732  return ThrowInfoType;
733  }
734 
735  llvm::FunctionCallee getThrowFn() {
736  // _CxxThrowException is passed an exception object and a ThrowInfo object
737  // which describes the exception.
738  llvm::Type *Args[] = {CGM.Int8PtrTy, getThrowInfoType()->getPointerTo()};
739  llvm::FunctionType *FTy =
740  llvm::FunctionType::get(CGM.VoidTy, Args, /*isVarArg=*/false);
741  llvm::FunctionCallee Throw =
742  CGM.CreateRuntimeFunction(FTy, "_CxxThrowException");
743  // _CxxThrowException is stdcall on 32-bit x86 platforms.
744  if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
745  if (auto *Fn = dyn_cast<llvm::Function>(Throw.getCallee()))
746  Fn->setCallingConv(llvm::CallingConv::X86_StdCall);
747  }
748  return Throw;
749  }
750 
751  llvm::Function *getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
752  CXXCtorType CT);
753 
754  llvm::Constant *getCatchableType(QualType T,
755  uint32_t NVOffset = 0,
756  int32_t VBPtrOffset = -1,
757  uint32_t VBIndex = 0);
758 
759  llvm::GlobalVariable *getCatchableTypeArray(QualType T);
760 
761  llvm::GlobalVariable *getThrowInfo(QualType T) override;
762 
763  std::pair<llvm::Value *, const CXXRecordDecl *>
764  LoadVTablePtr(CodeGenFunction &CGF, Address This,
765  const CXXRecordDecl *RD) override;
766 
767 private:
768  typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy;
769  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VTablesMapTy;
770  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalValue *> VFTablesMapTy;
771  /// All the vftables that have been referenced.
772  VFTablesMapTy VFTablesMap;
773  VTablesMapTy VTablesMap;
774 
775  /// This set holds the record decls we've deferred vtable emission for.
776  llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables;
777 
778 
779  /// All the vbtables which have been referenced.
780  llvm::DenseMap<const CXXRecordDecl *, VBTableGlobals> VBTablesMap;
781 
782  /// Info on the global variable used to guard initialization of static locals.
783  /// The BitIndex field is only used for externally invisible declarations.
784  struct GuardInfo {
785  GuardInfo() : Guard(nullptr), BitIndex(0) {}
786  llvm::GlobalVariable *Guard;
787  unsigned BitIndex;
788  };
789 
790  /// Map from DeclContext to the current guard variable. We assume that the
791  /// AST is visited in source code order.
792  llvm::DenseMap<const DeclContext *, GuardInfo> GuardVariableMap;
793  llvm::DenseMap<const DeclContext *, GuardInfo> ThreadLocalGuardVariableMap;
794  llvm::DenseMap<const DeclContext *, unsigned> ThreadSafeGuardNumMap;
795 
796  llvm::DenseMap<size_t, llvm::StructType *> TypeDescriptorTypeMap;
797  llvm::StructType *BaseClassDescriptorType;
798  llvm::StructType *ClassHierarchyDescriptorType;
799  llvm::StructType *CompleteObjectLocatorType;
800 
801  llvm::DenseMap<QualType, llvm::GlobalVariable *> CatchableTypeArrays;
802 
803  llvm::StructType *CatchableTypeType;
804  llvm::DenseMap<uint32_t, llvm::StructType *> CatchableTypeArrayTypeMap;
805  llvm::StructType *ThrowInfoType;
806 };
807 
808 }
809 
812  switch (CGM.getTarget().getTriple().getArch()) {
813  default:
814  // FIXME: Implement for other architectures.
815  return RAA_Default;
816 
817  case llvm::Triple::thumb:
818  // Use the simple Itanium rules for now.
819  // FIXME: This is incompatible with MSVC for arguments with a dtor and no
820  // copy ctor.
821  return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
822 
823  case llvm::Triple::x86:
824  // All record arguments are passed in memory on x86. Decide whether to
825  // construct the object directly in argument memory, or to construct the
826  // argument elsewhere and copy the bytes during the call.
827 
828  // If C++ prohibits us from making a copy, construct the arguments directly
829  // into argument memory.
830  if (!RD->canPassInRegisters())
831  return RAA_DirectInMemory;
832 
833  // Otherwise, construct the argument into a temporary and copy the bytes
834  // into the outgoing argument memory.
835  return RAA_Default;
836 
837  case llvm::Triple::x86_64:
838  case llvm::Triple::aarch64:
839  return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
840  }
841 
842  llvm_unreachable("invalid enum");
843 }
844 
845 void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
846  const CXXDeleteExpr *DE,
847  Address Ptr,
848  QualType ElementType,
849  const CXXDestructorDecl *Dtor) {
850  // FIXME: Provide a source location here even though there's no
851  // CXXMemberCallExpr for dtor call.
852  bool UseGlobalDelete = DE->isGlobalDelete();
853  CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
854  llvm::Value *MDThis = EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE);
855  if (UseGlobalDelete)
856  CGF.EmitDeleteCall(DE->getOperatorDelete(), MDThis, ElementType);
857 }
858 
859 void MicrosoftCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
860  llvm::Value *Args[] = {
861  llvm::ConstantPointerNull::get(CGM.Int8PtrTy),
862  llvm::ConstantPointerNull::get(getThrowInfoType()->getPointerTo())};
863  llvm::FunctionCallee Fn = getThrowFn();
864  if (isNoReturn)
865  CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, Args);
866  else
867  CGF.EmitRuntimeCallOrInvoke(Fn, Args);
868 }
869 
870 void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
871  const CXXCatchStmt *S) {
872  // In the MS ABI, the runtime handles the copy, and the catch handler is
873  // responsible for destruction.
874  VarDecl *CatchParam = S->getExceptionDecl();
875  llvm::BasicBlock *CatchPadBB = CGF.Builder.GetInsertBlock();
876  llvm::CatchPadInst *CPI =
877  cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
878  CGF.CurrentFuncletPad = CPI;
879 
880  // If this is a catch-all or the catch parameter is unnamed, we don't need to
881  // emit an alloca to the object.
882  if (!CatchParam || !CatchParam->getDeclName()) {
883  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
884  return;
885  }
886 
888  CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
889  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
890  CGF.EmitAutoVarCleanups(var);
891 }
892 
893 /// We need to perform a generic polymorphic operation (like a typeid
894 /// or a cast), which requires an object with a vfptr. Adjust the
895 /// address to point to an object with a vfptr.
896 std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
897 MicrosoftCXXABI::performBaseAdjustment(CodeGenFunction &CGF, Address Value,
898  QualType SrcRecordTy) {
899  Value = CGF.Builder.CreateBitCast(Value, CGF.Int8PtrTy);
900  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
901  const ASTContext &Context = getContext();
902 
903  // If the class itself has a vfptr, great. This check implicitly
904  // covers non-virtual base subobjects: a class with its own virtual
905  // functions would be a candidate to be a primary base.
906  if (Context.getASTRecordLayout(SrcDecl).hasExtendableVFPtr())
907  return std::make_tuple(Value, llvm::ConstantInt::get(CGF.Int32Ty, 0),
908  SrcDecl);
909 
910  // Okay, one of the vbases must have a vfptr, or else this isn't
911  // actually a polymorphic class.
912  const CXXRecordDecl *PolymorphicBase = nullptr;
913  for (auto &Base : SrcDecl->vbases()) {
914  const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
915  if (Context.getASTRecordLayout(BaseDecl).hasExtendableVFPtr()) {
916  PolymorphicBase = BaseDecl;
917  break;
918  }
919  }
920  assert(PolymorphicBase && "polymorphic class has no apparent vfptr?");
921 
923  GetVirtualBaseClassOffset(CGF, Value, SrcDecl, PolymorphicBase);
924  llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(Value.getPointer(), Offset);
925  CharUnits VBaseAlign =
926  CGF.CGM.getVBaseAlignment(Value.getAlignment(), SrcDecl, PolymorphicBase);
927  return std::make_tuple(Address(Ptr, VBaseAlign), Offset, PolymorphicBase);
928 }
929 
930 bool MicrosoftCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
931  QualType SrcRecordTy) {
932  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
933  return IsDeref &&
934  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
935 }
936 
937 static llvm::CallBase *emitRTtypeidCall(CodeGenFunction &CGF,
938  llvm::Value *Argument) {
939  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
940  llvm::FunctionType *FTy =
941  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false);
942  llvm::Value *Args[] = {Argument};
943  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(FTy, "__RTtypeid");
944  return CGF.EmitRuntimeCallOrInvoke(Fn, Args);
945 }
946 
947 void MicrosoftCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
948  llvm::CallBase *Call =
949  emitRTtypeidCall(CGF, llvm::Constant::getNullValue(CGM.VoidPtrTy));
950  Call->setDoesNotReturn();
951  CGF.Builder.CreateUnreachable();
952 }
953 
954 llvm::Value *MicrosoftCXXABI::EmitTypeid(CodeGenFunction &CGF,
955  QualType SrcRecordTy,
956  Address ThisPtr,
957  llvm::Type *StdTypeInfoPtrTy) {
958  std::tie(ThisPtr, std::ignore, std::ignore) =
959  performBaseAdjustment(CGF, ThisPtr, SrcRecordTy);
960  llvm::CallBase *Typeid = emitRTtypeidCall(CGF, ThisPtr.getPointer());
961  return CGF.Builder.CreateBitCast(Typeid, StdTypeInfoPtrTy);
962 }
963 
964 bool MicrosoftCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
965  QualType SrcRecordTy) {
966  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
967  return SrcIsPtr &&
968  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
969 }
970 
971 llvm::Value *MicrosoftCXXABI::EmitDynamicCastCall(
972  CodeGenFunction &CGF, Address This, QualType SrcRecordTy,
973  QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
974  llvm::Type *DestLTy = CGF.ConvertType(DestTy);
975 
976  llvm::Value *SrcRTTI =
978  llvm::Value *DestRTTI =
979  CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
980 
982  std::tie(This, Offset, std::ignore) =
983  performBaseAdjustment(CGF, This, SrcRecordTy);
984  llvm::Value *ThisPtr = This.getPointer();
985  Offset = CGF.Builder.CreateTrunc(Offset, CGF.Int32Ty);
986 
987  // PVOID __RTDynamicCast(
988  // PVOID inptr,
989  // LONG VfDelta,
990  // PVOID SrcType,
991  // PVOID TargetType,
992  // BOOL isReference)
993  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy, CGF.Int32Ty, CGF.Int8PtrTy,
994  CGF.Int8PtrTy, CGF.Int32Ty};
995  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
996  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
997  "__RTDynamicCast");
998  llvm::Value *Args[] = {
999  ThisPtr, Offset, SrcRTTI, DestRTTI,
1000  llvm::ConstantInt::get(CGF.Int32Ty, DestTy->isReferenceType())};
1001  ThisPtr = CGF.EmitRuntimeCallOrInvoke(Function, Args);
1002  return CGF.Builder.CreateBitCast(ThisPtr, DestLTy);
1003 }
1004 
1005 llvm::Value *
1006 MicrosoftCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
1007  QualType SrcRecordTy,
1008  QualType DestTy) {
1009  std::tie(Value, std::ignore, std::ignore) =
1010  performBaseAdjustment(CGF, Value, SrcRecordTy);
1011 
1012  // PVOID __RTCastToVoid(
1013  // PVOID inptr)
1014  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
1015  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
1016  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
1017  "__RTCastToVoid");
1018  llvm::Value *Args[] = {Value.getPointer()};
1019  return CGF.EmitRuntimeCall(Function, Args);
1020 }
1021 
1022 bool MicrosoftCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
1023  return false;
1024 }
1025 
1026 llvm::Value *MicrosoftCXXABI::GetVirtualBaseClassOffset(
1027  CodeGenFunction &CGF, Address This, const CXXRecordDecl *ClassDecl,
1028  const CXXRecordDecl *BaseClassDecl) {
1029  const ASTContext &Context = getContext();
1030  int64_t VBPtrChars =
1031  Context.getASTRecordLayout(ClassDecl).getVBPtrOffset().getQuantity();
1032  llvm::Value *VBPtrOffset = llvm::ConstantInt::get(CGM.PtrDiffTy, VBPtrChars);
1033  CharUnits IntSize = Context.getTypeSizeInChars(Context.IntTy);
1034  CharUnits VBTableChars =
1035  IntSize *
1036  CGM.getMicrosoftVTableContext().getVBTableIndex(ClassDecl, BaseClassDecl);
1037  llvm::Value *VBTableOffset =
1038  llvm::ConstantInt::get(CGM.IntTy, VBTableChars.getQuantity());
1039 
1040  llvm::Value *VBPtrToNewBase =
1041  GetVBaseOffsetFromVBPtr(CGF, This, VBPtrOffset, VBTableOffset);
1042  VBPtrToNewBase =
1043  CGF.Builder.CreateSExtOrBitCast(VBPtrToNewBase, CGM.PtrDiffTy);
1044  return CGF.Builder.CreateNSWAdd(VBPtrOffset, VBPtrToNewBase);
1045 }
1046 
1047 bool MicrosoftCXXABI::HasThisReturn(GlobalDecl GD) const {
1048  return isa<CXXConstructorDecl>(GD.getDecl());
1049 }
1050 
1051 static bool isDeletingDtor(GlobalDecl GD) {
1052  return isa<CXXDestructorDecl>(GD.getDecl()) &&
1053  GD.getDtorType() == Dtor_Deleting;
1054 }
1055 
1056 bool MicrosoftCXXABI::hasMostDerivedReturn(GlobalDecl GD) const {
1057  return isDeletingDtor(GD);
1058 }
1059 
1060 static bool IsSizeGreaterThan128(const CXXRecordDecl *RD) {
1061  return RD->getASTContext().getTypeSize(RD->getTypeForDecl()) > 128;
1062 }
1063 
1065  // For AArch64, we use the C++14 definition of an aggregate, so we also
1066  // check for:
1067  // No private or protected non static data members.
1068  // No base classes
1069  // No virtual functions
1070  // Additionally, we need to ensure that there is a trivial copy assignment
1071  // operator, a trivial destructor and no user-provided constructors.
1072  if (RD->hasProtectedFields() || RD->hasPrivateFields())
1073  return true;
1074  if (RD->getNumBases() > 0)
1075  return true;
1076  if (RD->isPolymorphic())
1077  return true;
1078  if (RD->hasNonTrivialCopyAssignment())
1079  return true;
1080  for (const CXXConstructorDecl *Ctor : RD->ctors())
1081  if (Ctor->isUserProvided())
1082  return true;
1083  if (RD->hasNonTrivialDestructor())
1084  return true;
1085  return false;
1086 }
1087 
1089  const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
1090  if (!RD)
1091  return false;
1092 
1093  bool isAArch64 = CGM.getTarget().getTriple().isAArch64();
1094  bool isSimple = !isAArch64 || !hasMicrosoftABIRestrictions(RD);
1095  bool isIndirectReturn =
1096  isAArch64 ? (!RD->canPassInRegisters() ||
1098  : !RD->isPOD();
1099  bool isInstanceMethod = FI.isInstanceMethod();
1100 
1101  if (isIndirectReturn || !isSimple || isInstanceMethod) {
1102  CharUnits Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
1103  FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
1104  FI.getReturnInfo().setSRetAfterThis(isInstanceMethod);
1105 
1106  FI.getReturnInfo().setInReg(isAArch64 &&
1107  !(isSimple && IsSizeGreaterThan128(RD)));
1108 
1109  return true;
1110  }
1111 
1112  // Otherwise, use the C ABI rules.
1113  return false;
1114 }
1115 
1116 llvm::BasicBlock *
1117 MicrosoftCXXABI::EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
1118  const CXXRecordDecl *RD) {
1119  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1120  assert(IsMostDerivedClass &&
1121  "ctor for a class with virtual bases must have an implicit parameter");
1122  llvm::Value *IsCompleteObject =
1123  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1124 
1125  llvm::BasicBlock *CallVbaseCtorsBB = CGF.createBasicBlock("ctor.init_vbases");
1126  llvm::BasicBlock *SkipVbaseCtorsBB = CGF.createBasicBlock("ctor.skip_vbases");
1127  CGF.Builder.CreateCondBr(IsCompleteObject,
1128  CallVbaseCtorsBB, SkipVbaseCtorsBB);
1129 
1130  CGF.EmitBlock(CallVbaseCtorsBB);
1131 
1132  // Fill in the vbtable pointers here.
1133  EmitVBPtrStores(CGF, RD);
1134 
1135  // CGF will put the base ctor calls in this basic block for us later.
1136 
1137  return SkipVbaseCtorsBB;
1138 }
1139 
1140 llvm::BasicBlock *
1141 MicrosoftCXXABI::EmitDtorCompleteObjectHandler(CodeGenFunction &CGF) {
1142  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1143  assert(IsMostDerivedClass &&
1144  "ctor for a class with virtual bases must have an implicit parameter");
1145  llvm::Value *IsCompleteObject =
1146  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1147 
1148  llvm::BasicBlock *CallVbaseDtorsBB = CGF.createBasicBlock("Dtor.dtor_vbases");
1149  llvm::BasicBlock *SkipVbaseDtorsBB = CGF.createBasicBlock("Dtor.skip_vbases");
1150  CGF.Builder.CreateCondBr(IsCompleteObject,
1151  CallVbaseDtorsBB, SkipVbaseDtorsBB);
1152 
1153  CGF.EmitBlock(CallVbaseDtorsBB);
1154  // CGF will put the base dtor calls in this basic block for us later.
1155 
1156  return SkipVbaseDtorsBB;
1157 }
1158 
1159 void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers(
1160  CodeGenFunction &CGF, const CXXRecordDecl *RD) {
1161  // In most cases, an override for a vbase virtual method can adjust
1162  // the "this" parameter by applying a constant offset.
1163  // However, this is not enough while a constructor or a destructor of some
1164  // class X is being executed if all the following conditions are met:
1165  // - X has virtual bases, (1)
1166  // - X overrides a virtual method M of a vbase Y, (2)
1167  // - X itself is a vbase of the most derived class.
1168  //
1169  // If (1) and (2) are true, the vtorDisp for vbase Y is a hidden member of X
1170  // which holds the extra amount of "this" adjustment we must do when we use
1171  // the X vftables (i.e. during X ctor or dtor).
1172  // Outside the ctors and dtors, the values of vtorDisps are zero.
1173 
1174  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1175  typedef ASTRecordLayout::VBaseOffsetsMapTy VBOffsets;
1176  const VBOffsets &VBaseMap = Layout.getVBaseOffsetsMap();
1177  CGBuilderTy &Builder = CGF.Builder;
1178 
1179  unsigned AS = getThisAddress(CGF).getAddressSpace();
1180  llvm::Value *Int8This = nullptr; // Initialize lazily.
1181 
1182  for (const CXXBaseSpecifier &S : RD->vbases()) {
1183  const CXXRecordDecl *VBase = S.getType()->getAsCXXRecordDecl();
1184  auto I = VBaseMap.find(VBase);
1185  assert(I != VBaseMap.end());
1186  if (!I->second.hasVtorDisp())
1187  continue;
1188 
1189  llvm::Value *VBaseOffset =
1190  GetVirtualBaseClassOffset(CGF, getThisAddress(CGF), RD, VBase);
1191  uint64_t ConstantVBaseOffset = I->second.VBaseOffset.getQuantity();
1192 
1193  // vtorDisp_for_vbase = vbptr[vbase_idx] - offsetof(RD, vbase).
1194  llvm::Value *VtorDispValue = Builder.CreateSub(
1195  VBaseOffset, llvm::ConstantInt::get(CGM.PtrDiffTy, ConstantVBaseOffset),
1196  "vtordisp.value");
1197  VtorDispValue = Builder.CreateTruncOrBitCast(VtorDispValue, CGF.Int32Ty);
1198 
1199  if (!Int8This)
1200  Int8This = Builder.CreateBitCast(getThisValue(CGF),
1201  CGF.Int8Ty->getPointerTo(AS));
1202  llvm::Value *VtorDispPtr = Builder.CreateInBoundsGEP(Int8This, VBaseOffset);
1203  // vtorDisp is always the 32-bits before the vbase in the class layout.
1204  VtorDispPtr = Builder.CreateConstGEP1_32(VtorDispPtr, -4);
1205  VtorDispPtr = Builder.CreateBitCast(
1206  VtorDispPtr, CGF.Int32Ty->getPointerTo(AS), "vtordisp.ptr");
1207 
1208  Builder.CreateAlignedStore(VtorDispValue, VtorDispPtr,
1210  }
1211 }
1212 
1213 static bool hasDefaultCXXMethodCC(ASTContext &Context,
1214  const CXXMethodDecl *MD) {
1215  CallingConv ExpectedCallingConv = Context.getDefaultCallingConvention(
1216  /*IsVariadic=*/false, /*IsCXXMethod=*/true);
1217  CallingConv ActualCallingConv =
1218  MD->getType()->castAs<FunctionProtoType>()->getCallConv();
1219  return ExpectedCallingConv == ActualCallingConv;
1220 }
1221 
1222 void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
1223  // There's only one constructor type in this ABI.
1224  CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete));
1225 
1226  // Exported default constructors either have a simple call-site where they use
1227  // the typical calling convention and have a single 'this' pointer for an
1228  // argument -or- they get a wrapper function which appropriately thunks to the
1229  // real default constructor. This thunk is the default constructor closure.
1230  if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor())
1231  if (!hasDefaultCXXMethodCC(getContext(), D) || D->getNumParams() != 0) {
1232  llvm::Function *Fn = getAddrOfCXXCtorClosure(D, Ctor_DefaultClosure);
1233  Fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
1234  CGM.setGVProperties(Fn, D);
1235  }
1236 }
1237 
1238 void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF,
1239  const CXXRecordDecl *RD) {
1240  Address This = getThisAddress(CGF);
1241  This = CGF.Builder.CreateElementBitCast(This, CGM.Int8Ty, "this.int8");
1242  const ASTContext &Context = getContext();
1243  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
1244 
1245  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
1246  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
1247  const std::unique_ptr<VPtrInfo> &VBT = (*VBGlobals.VBTables)[I];
1248  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
1249  const ASTRecordLayout &SubobjectLayout =
1250  Context.getASTRecordLayout(VBT->IntroducingObject);
1251  CharUnits Offs = VBT->NonVirtualOffset;
1252  Offs += SubobjectLayout.getVBPtrOffset();
1253  if (VBT->getVBaseWithVPtr())
1254  Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
1255  Address VBPtr = CGF.Builder.CreateConstInBoundsByteGEP(This, Offs);
1256  llvm::Value *GVPtr =
1257  CGF.Builder.CreateConstInBoundsGEP2_32(GV->getValueType(), GV, 0, 0);
1258  VBPtr = CGF.Builder.CreateElementBitCast(VBPtr, GVPtr->getType(),
1259  "vbptr." + VBT->ObjectWithVPtr->getName());
1260  CGF.Builder.CreateStore(GVPtr, VBPtr);
1261  }
1262 }
1263 
1265 MicrosoftCXXABI::buildStructorSignature(GlobalDecl GD,
1266  SmallVectorImpl<CanQualType> &ArgTys) {
1267  AddedStructorArgs Added;
1268  // TODO: 'for base' flag
1269  if (isa<CXXDestructorDecl>(GD.getDecl()) &&
1270  GD.getDtorType() == Dtor_Deleting) {
1271  // The scalar deleting destructor takes an implicit int parameter.
1272  ArgTys.push_back(getContext().IntTy);
1273  ++Added.Suffix;
1274  }
1275  auto *CD = dyn_cast<CXXConstructorDecl>(GD.getDecl());
1276  if (!CD)
1277  return Added;
1278 
1279  // All parameters are already in place except is_most_derived, which goes
1280  // after 'this' if it's variadic and last if it's not.
1281 
1282  const CXXRecordDecl *Class = CD->getParent();
1283  const FunctionProtoType *FPT = CD->getType()->castAs<FunctionProtoType>();
1284  if (Class->getNumVBases()) {
1285  if (FPT->isVariadic()) {
1286  ArgTys.insert(ArgTys.begin() + 1, getContext().IntTy);
1287  ++Added.Prefix;
1288  } else {
1289  ArgTys.push_back(getContext().IntTy);
1290  ++Added.Suffix;
1291  }
1292  }
1293 
1294  return Added;
1295 }
1296 
1297 void MicrosoftCXXABI::setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
1298  const CXXDestructorDecl *Dtor,
1299  CXXDtorType DT) const {
1300  // Deleting destructor variants are never imported or exported. Give them the
1301  // default storage class.
1302  if (DT == Dtor_Deleting) {
1303  GV->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
1304  } else {
1305  const NamedDecl *ND = Dtor;
1306  CGM.setDLLImportDLLExport(GV, ND);
1307  }
1308 }
1309 
1310 llvm::GlobalValue::LinkageTypes MicrosoftCXXABI::getCXXDestructorLinkage(
1311  GVALinkage Linkage, const CXXDestructorDecl *Dtor, CXXDtorType DT) const {
1312  // Internal things are always internal, regardless of attributes. After this,
1313  // we know the thunk is externally visible.
1314  if (Linkage == GVA_Internal)
1316 
1317  switch (DT) {
1318  case Dtor_Base:
1319  // The base destructor most closely tracks the user-declared constructor, so
1320  // we delegate back to the normal declarator case.
1321  return CGM.getLLVMLinkageForDeclarator(Dtor, Linkage,
1322  /*IsConstantVariable=*/false);
1323  case Dtor_Complete:
1324  // The complete destructor is like an inline function, but it may be
1325  // imported and therefore must be exported as well. This requires changing
1326  // the linkage if a DLL attribute is present.
1327  if (Dtor->hasAttr<DLLExportAttr>())
1328  return llvm::GlobalValue::WeakODRLinkage;
1329  if (Dtor->hasAttr<DLLImportAttr>())
1330  return llvm::GlobalValue::AvailableExternallyLinkage;
1331  return llvm::GlobalValue::LinkOnceODRLinkage;
1332  case Dtor_Deleting:
1333  // Deleting destructors are like inline functions. They have vague linkage
1334  // and are emitted everywhere they are used. They are internal if the class
1335  // is internal.
1336  return llvm::GlobalValue::LinkOnceODRLinkage;
1337  case Dtor_Comdat:
1338  llvm_unreachable("MS C++ ABI does not support comdat dtors");
1339  }
1340  llvm_unreachable("invalid dtor type");
1341 }
1342 
1343 void MicrosoftCXXABI::EmitCXXDestructors(const CXXDestructorDecl *D) {
1344  // The TU defining a dtor is only guaranteed to emit a base destructor. All
1345  // other destructor variants are delegating thunks.
1346  CGM.EmitGlobal(GlobalDecl(D, Dtor_Base));
1347 
1348  // If the class is dllexported, emit the complete (vbase) destructor wherever
1349  // the base dtor is emitted.
1350  // FIXME: To match MSVC, this should only be done when the class is exported
1351  // with -fdllexport-inlines enabled.
1352  if (D->getParent()->getNumVBases() > 0 && D->hasAttr<DLLExportAttr>())
1353  CGM.EmitGlobal(GlobalDecl(D, Dtor_Complete));
1354 }
1355 
1356 CharUnits
1357 MicrosoftCXXABI::getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
1358  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1359 
1360  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1361  // Complete destructors take a pointer to the complete object as a
1362  // parameter, thus don't need this adjustment.
1363  if (GD.getDtorType() == Dtor_Complete)
1364  return CharUnits();
1365 
1366  // There's no Dtor_Base in vftable but it shares the this adjustment with
1367  // the deleting one, so look it up instead.
1368  GD = GlobalDecl(DD, Dtor_Deleting);
1369  }
1370 
1372  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(GD);
1373  CharUnits Adjustment = ML.VFPtrOffset;
1374 
1375  // Normal virtual instance methods need to adjust from the vfptr that first
1376  // defined the virtual method to the virtual base subobject, but destructors
1377  // do not. The vector deleting destructor thunk applies this adjustment for
1378  // us if necessary.
1379  if (isa<CXXDestructorDecl>(MD))
1380  Adjustment = CharUnits::Zero();
1381 
1382  if (ML.VBase) {
1383  const ASTRecordLayout &DerivedLayout =
1384  getContext().getASTRecordLayout(MD->getParent());
1385  Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase);
1386  }
1387 
1388  return Adjustment;
1389 }
1390 
1391 Address MicrosoftCXXABI::adjustThisArgumentForVirtualFunctionCall(
1392  CodeGenFunction &CGF, GlobalDecl GD, Address This,
1393  bool VirtualCall) {
1394  if (!VirtualCall) {
1395  // If the call of a virtual function is not virtual, we just have to
1396  // compensate for the adjustment the virtual function does in its prologue.
1397  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD);
1398  if (Adjustment.isZero())
1399  return This;
1400 
1401  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
1402  assert(Adjustment.isPositive());
1403  return CGF.Builder.CreateConstByteGEP(This, Adjustment);
1404  }
1405 
1406  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1407 
1408  GlobalDecl LookupGD = GD;
1409  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1410  // Complete dtors take a pointer to the complete object,
1411  // thus don't need adjustment.
1412  if (GD.getDtorType() == Dtor_Complete)
1413  return This;
1414 
1415  // There's only Dtor_Deleting in vftable but it shares the this adjustment
1416  // with the base one, so look up the deleting one instead.
1417  LookupGD = GlobalDecl(DD, Dtor_Deleting);
1418  }
1420  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
1421 
1422  CharUnits StaticOffset = ML.VFPtrOffset;
1423 
1424  // Base destructors expect 'this' to point to the beginning of the base
1425  // subobject, not the first vfptr that happens to contain the virtual dtor.
1426  // However, we still need to apply the virtual base adjustment.
1427  if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
1428  StaticOffset = CharUnits::Zero();
1429 
1430  Address Result = This;
1431  if (ML.VBase) {
1432  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1433 
1434  const CXXRecordDecl *Derived = MD->getParent();
1435  const CXXRecordDecl *VBase = ML.VBase;
1436  llvm::Value *VBaseOffset =
1437  GetVirtualBaseClassOffset(CGF, Result, Derived, VBase);
1438  llvm::Value *VBasePtr =
1439  CGF.Builder.CreateInBoundsGEP(Result.getPointer(), VBaseOffset);
1440  CharUnits VBaseAlign =
1441  CGF.CGM.getVBaseAlignment(Result.getAlignment(), Derived, VBase);
1442  Result = Address(VBasePtr, VBaseAlign);
1443  }
1444  if (!StaticOffset.isZero()) {
1445  assert(StaticOffset.isPositive());
1446  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1447  if (ML.VBase) {
1448  // Non-virtual adjustment might result in a pointer outside the allocated
1449  // object, e.g. if the final overrider class is laid out after the virtual
1450  // base that declares a method in the most derived class.
1451  // FIXME: Update the code that emits this adjustment in thunks prologues.
1452  Result = CGF.Builder.CreateConstByteGEP(Result, StaticOffset);
1453  } else {
1454  Result = CGF.Builder.CreateConstInBoundsByteGEP(Result, StaticOffset);
1455  }
1456  }
1457  return Result;
1458 }
1459 
1460 void MicrosoftCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
1461  QualType &ResTy,
1462  FunctionArgList &Params) {
1463  ASTContext &Context = getContext();
1464  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1465  assert(isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD));
1466  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1467  auto *IsMostDerived = ImplicitParamDecl::Create(
1468  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1469  &Context.Idents.get("is_most_derived"), Context.IntTy,
1471  // The 'most_derived' parameter goes second if the ctor is variadic and last
1472  // if it's not. Dtors can't be variadic.
1473  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
1474  if (FPT->isVariadic())
1475  Params.insert(Params.begin() + 1, IsMostDerived);
1476  else
1477  Params.push_back(IsMostDerived);
1478  getStructorImplicitParamDecl(CGF) = IsMostDerived;
1479  } else if (isDeletingDtor(CGF.CurGD)) {
1480  auto *ShouldDelete = ImplicitParamDecl::Create(
1481  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1482  &Context.Idents.get("should_call_delete"), Context.IntTy,
1484  Params.push_back(ShouldDelete);
1485  getStructorImplicitParamDecl(CGF) = ShouldDelete;
1486  }
1487 }
1488 
1489 void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
1490  // Naked functions have no prolog.
1491  if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
1492  return;
1493 
1494  // Overridden virtual methods of non-primary bases need to adjust the incoming
1495  // 'this' pointer in the prologue. In this hierarchy, C::b will subtract
1496  // sizeof(void*) to adjust from B* to C*:
1497  // struct A { virtual void a(); };
1498  // struct B { virtual void b(); };
1499  // struct C : A, B { virtual void b(); };
1500  //
1501  // Leave the value stored in the 'this' alloca unadjusted, so that the
1502  // debugger sees the unadjusted value. Microsoft debuggers require this, and
1503  // will apply the ThisAdjustment in the method type information.
1504  // FIXME: Do something better for DWARF debuggers, which won't expect this,
1505  // without making our codegen depend on debug info settings.
1506  llvm::Value *This = loadIncomingCXXThis(CGF);
1507  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1508  if (!CGF.CurFuncIsThunk && MD->isVirtual()) {
1509  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD);
1510  if (!Adjustment.isZero()) {
1511  unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
1512  llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS),
1513  *thisTy = This->getType();
1514  This = CGF.Builder.CreateBitCast(This, charPtrTy);
1515  assert(Adjustment.isPositive());
1516  This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This,
1517  -Adjustment.getQuantity());
1518  This = CGF.Builder.CreateBitCast(This, thisTy, "this.adjusted");
1519  }
1520  }
1521  setCXXABIThisValue(CGF, This);
1522 
1523  // If this is a function that the ABI specifies returns 'this', initialize
1524  // the return slot to 'this' at the start of the function.
1525  //
1526  // Unlike the setting of return types, this is done within the ABI
1527  // implementation instead of by clients of CGCXXABI because:
1528  // 1) getThisValue is currently protected
1529  // 2) in theory, an ABI could implement 'this' returns some other way;
1530  // HasThisReturn only specifies a contract, not the implementation
1531  if (HasThisReturn(CGF.CurGD))
1532  CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
1533  else if (hasMostDerivedReturn(CGF.CurGD))
1534  CGF.Builder.CreateStore(CGF.EmitCastToVoidPtr(getThisValue(CGF)),
1535  CGF.ReturnValue);
1536 
1537  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1538  assert(getStructorImplicitParamDecl(CGF) &&
1539  "no implicit parameter for a constructor with virtual bases?");
1540  getStructorImplicitParamValue(CGF)
1541  = CGF.Builder.CreateLoad(
1542  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1543  "is_most_derived");
1544  }
1545 
1546  if (isDeletingDtor(CGF.CurGD)) {
1547  assert(getStructorImplicitParamDecl(CGF) &&
1548  "no implicit parameter for a deleting destructor?");
1549  getStructorImplicitParamValue(CGF)
1550  = CGF.Builder.CreateLoad(
1551  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1552  "should_call_delete");
1553  }
1554 }
1555 
1556 CGCXXABI::AddedStructorArgs MicrosoftCXXABI::addImplicitConstructorArgs(
1558  bool ForVirtualBase, bool Delegating, CallArgList &Args) {
1559  assert(Type == Ctor_Complete || Type == Ctor_Base);
1560 
1561  // Check if we need a 'most_derived' parameter.
1562  if (!D->getParent()->getNumVBases())
1563  return AddedStructorArgs{};
1564 
1565  // Add the 'most_derived' argument second if we are variadic or last if not.
1566  const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
1567  llvm::Value *MostDerivedArg;
1568  if (Delegating) {
1569  MostDerivedArg = getStructorImplicitParamValue(CGF);
1570  } else {
1571  MostDerivedArg = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete);
1572  }
1573  RValue RV = RValue::get(MostDerivedArg);
1574  if (FPT->isVariadic()) {
1575  Args.insert(Args.begin() + 1, CallArg(RV, getContext().IntTy));
1576  return AddedStructorArgs::prefix(1);
1577  }
1578  Args.add(RV, getContext().IntTy);
1579  return AddedStructorArgs::suffix(1);
1580 }
1581 
1582 void MicrosoftCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
1583  const CXXDestructorDecl *DD,
1584  CXXDtorType Type, bool ForVirtualBase,
1585  bool Delegating, Address This,
1586  QualType ThisTy) {
1587  // Use the base destructor variant in place of the complete destructor variant
1588  // if the class has no virtual bases. This effectively implements some of the
1589  // -mconstructor-aliases optimization, but as part of the MS C++ ABI.
1590  if (Type == Dtor_Complete && DD->getParent()->getNumVBases() == 0)
1591  Type = Dtor_Base;
1592 
1593  GlobalDecl GD(DD, Type);
1594  CGCallee Callee = CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD), GD);
1595 
1596  if (DD->isVirtual()) {
1597  assert(Type != CXXDtorType::Dtor_Deleting &&
1598  "The deleting destructor should only be called via a virtual call");
1599  This = adjustThisArgumentForVirtualFunctionCall(CGF, GlobalDecl(DD, Type),
1600  This, false);
1601  }
1602 
1603  llvm::BasicBlock *BaseDtorEndBB = nullptr;
1604  if (ForVirtualBase && isa<CXXConstructorDecl>(CGF.CurCodeDecl)) {
1605  BaseDtorEndBB = EmitDtorCompleteObjectHandler(CGF);
1606  }
1607 
1608  CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
1609  /*ImplicitParam=*/nullptr,
1610  /*ImplicitParamTy=*/QualType(), nullptr);
1611  if (BaseDtorEndBB) {
1612  // Complete object handler should continue to be the remaining
1613  CGF.Builder.CreateBr(BaseDtorEndBB);
1614  CGF.EmitBlock(BaseDtorEndBB);
1615  }
1616 }
1617 
1618 void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
1619  const CXXRecordDecl *RD,
1620  llvm::GlobalVariable *VTable) {
1621  if (!CGM.getCodeGenOpts().LTOUnit)
1622  return;
1623 
1624  // The location of the first virtual function pointer in the virtual table,
1625  // aka the "address point" on Itanium. This is at offset 0 if RTTI is
1626  // disabled, or sizeof(void*) if RTTI is enabled.
1627  CharUnits AddressPoint =
1628  getContext().getLangOpts().RTTIData
1629  ? getContext().toCharUnitsFromBits(
1630  getContext().getTargetInfo().getPointerWidth(0))
1631  : CharUnits::Zero();
1632 
1633  if (Info.PathToIntroducingObject.empty()) {
1634  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1635  return;
1636  }
1637 
1638  // Add a bitset entry for the least derived base belonging to this vftable.
1639  CGM.AddVTableTypeMetadata(VTable, AddressPoint,
1640  Info.PathToIntroducingObject.back());
1641 
1642  // Add a bitset entry for each derived class that is laid out at the same
1643  // offset as the least derived base.
1644  for (unsigned I = Info.PathToIntroducingObject.size() - 1; I != 0; --I) {
1645  const CXXRecordDecl *DerivedRD = Info.PathToIntroducingObject[I - 1];
1646  const CXXRecordDecl *BaseRD = Info.PathToIntroducingObject[I];
1647 
1648  const ASTRecordLayout &Layout =
1649  getContext().getASTRecordLayout(DerivedRD);
1650  CharUnits Offset;
1651  auto VBI = Layout.getVBaseOffsetsMap().find(BaseRD);
1652  if (VBI == Layout.getVBaseOffsetsMap().end())
1653  Offset = Layout.getBaseClassOffset(BaseRD);
1654  else
1655  Offset = VBI->second.VBaseOffset;
1656  if (!Offset.isZero())
1657  return;
1658  CGM.AddVTableTypeMetadata(VTable, AddressPoint, DerivedRD);
1659  }
1660 
1661  // Finally do the same for the most derived class.
1662  if (Info.FullOffsetInMDC.isZero())
1663  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1664 }
1665 
1666 void MicrosoftCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
1667  const CXXRecordDecl *RD) {
1668  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1669  const VPtrInfoVector &VFPtrs = VFTContext.getVFPtrOffsets(RD);
1670 
1671  for (const std::unique_ptr<VPtrInfo>& Info : VFPtrs) {
1672  llvm::GlobalVariable *VTable = getAddrOfVTable(RD, Info->FullOffsetInMDC);
1673  if (VTable->hasInitializer())
1674  continue;
1675 
1676  const VTableLayout &VTLayout =
1677  VFTContext.getVFTableLayout(RD, Info->FullOffsetInMDC);
1678 
1679  llvm::Constant *RTTI = nullptr;
1680  if (any_of(VTLayout.vtable_components(),
1681  [](const VTableComponent &VTC) { return VTC.isRTTIKind(); }))
1682  RTTI = getMSCompleteObjectLocator(RD, *Info);
1683 
1684  ConstantInitBuilder Builder(CGM);
1685  auto Components = Builder.beginStruct();
1686  CGVT.createVTableInitializer(Components, VTLayout, RTTI);
1687  Components.finishAndSetAsInitializer(VTable);
1688 
1689  emitVTableTypeMetadata(*Info, RD, VTable);
1690  }
1691 }
1692 
1693 bool MicrosoftCXXABI::isVirtualOffsetNeededForVTableField(
1695  return Vptr.NearestVBase != nullptr;
1696 }
1697 
1698 llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor(
1699  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
1700  const CXXRecordDecl *NearestVBase) {
1701  llvm::Constant *VTableAddressPoint = getVTableAddressPoint(Base, VTableClass);
1702  if (!VTableAddressPoint) {
1703  assert(Base.getBase()->getNumVBases() &&
1704  !getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr());
1705  }
1706  return VTableAddressPoint;
1707 }
1708 
1710  const CXXRecordDecl *RD, const VPtrInfo &VFPtr,
1711  SmallString<256> &Name) {
1712  llvm::raw_svector_ostream Out(Name);
1713  MangleContext.mangleCXXVFTable(RD, VFPtr.MangledPath, Out);
1714 }
1715 
1716 llvm::Constant *
1717 MicrosoftCXXABI::getVTableAddressPoint(BaseSubobject Base,
1718  const CXXRecordDecl *VTableClass) {
1719  (void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
1720  VFTableIdTy ID(VTableClass, Base.getBaseOffset());
1721  return VFTablesMap[ID];
1722 }
1723 
1724 llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
1725  BaseSubobject Base, const CXXRecordDecl *VTableClass) {
1726  llvm::Constant *VFTable = getVTableAddressPoint(Base, VTableClass);
1727  assert(VFTable && "Couldn't find a vftable for the given base?");
1728  return VFTable;
1729 }
1730 
1731 llvm::GlobalVariable *MicrosoftCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
1732  CharUnits VPtrOffset) {
1733  // getAddrOfVTable may return 0 if asked to get an address of a vtable which
1734  // shouldn't be used in the given record type. We want to cache this result in
1735  // VFTablesMap, thus a simple zero check is not sufficient.
1736 
1737  VFTableIdTy ID(RD, VPtrOffset);
1738  VTablesMapTy::iterator I;
1739  bool Inserted;
1740  std::tie(I, Inserted) = VTablesMap.insert(std::make_pair(ID, nullptr));
1741  if (!Inserted)
1742  return I->second;
1743 
1744  llvm::GlobalVariable *&VTable = I->second;
1745 
1746  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
1747  const VPtrInfoVector &VFPtrs = VTContext.getVFPtrOffsets(RD);
1748 
1749  if (DeferredVFTables.insert(RD).second) {
1750  // We haven't processed this record type before.
1751  // Queue up this vtable for possible deferred emission.
1752  CGM.addDeferredVTable(RD);
1753 
1754 #ifndef NDEBUG
1755  // Create all the vftables at once in order to make sure each vftable has
1756  // a unique mangled name.
1757  llvm::StringSet<> ObservedMangledNames;
1758  for (size_t J = 0, F = VFPtrs.size(); J != F; ++J) {
1759  SmallString<256> Name;
1760  mangleVFTableName(getMangleContext(), RD, *VFPtrs[J], Name);
1761  if (!ObservedMangledNames.insert(Name.str()).second)
1762  llvm_unreachable("Already saw this mangling before?");
1763  }
1764 #endif
1765  }
1766 
1767  const std::unique_ptr<VPtrInfo> *VFPtrI = std::find_if(
1768  VFPtrs.begin(), VFPtrs.end(), [&](const std::unique_ptr<VPtrInfo>& VPI) {
1769  return VPI->FullOffsetInMDC == VPtrOffset;
1770  });
1771  if (VFPtrI == VFPtrs.end()) {
1772  VFTablesMap[ID] = nullptr;
1773  return nullptr;
1774  }
1775  const std::unique_ptr<VPtrInfo> &VFPtr = *VFPtrI;
1776 
1777  SmallString<256> VFTableName;
1778  mangleVFTableName(getMangleContext(), RD, *VFPtr, VFTableName);
1779 
1780  // Classes marked __declspec(dllimport) need vftables generated on the
1781  // import-side in order to support features like constexpr. No other
1782  // translation unit relies on the emission of the local vftable, translation
1783  // units are expected to generate them as needed.
1784  //
1785  // Because of this unique behavior, we maintain this logic here instead of
1786  // getVTableLinkage.
1787  llvm::GlobalValue::LinkageTypes VFTableLinkage =
1788  RD->hasAttr<DLLImportAttr>() ? llvm::GlobalValue::LinkOnceODRLinkage
1789  : CGM.getVTableLinkage(RD);
1790  bool VFTableComesFromAnotherTU =
1791  llvm::GlobalValue::isAvailableExternallyLinkage(VFTableLinkage) ||
1792  llvm::GlobalValue::isExternalLinkage(VFTableLinkage);
1793  bool VTableAliasIsRequred =
1794  !VFTableComesFromAnotherTU && getContext().getLangOpts().RTTIData;
1795 
1796  if (llvm::GlobalValue *VFTable =
1797  CGM.getModule().getNamedGlobal(VFTableName)) {
1798  VFTablesMap[ID] = VFTable;
1799  VTable = VTableAliasIsRequred
1800  ? cast<llvm::GlobalVariable>(
1801  cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
1802  : cast<llvm::GlobalVariable>(VFTable);
1803  return VTable;
1804  }
1805 
1806  const VTableLayout &VTLayout =
1807  VTContext.getVFTableLayout(RD, VFPtr->FullOffsetInMDC);
1808  llvm::GlobalValue::LinkageTypes VTableLinkage =
1809  VTableAliasIsRequred ? llvm::GlobalValue::PrivateLinkage : VFTableLinkage;
1810 
1811  StringRef VTableName = VTableAliasIsRequred ? StringRef() : VFTableName.str();
1812 
1813  llvm::Type *VTableType = CGM.getVTables().getVTableType(VTLayout);
1814 
1815  // Create a backing variable for the contents of VTable. The VTable may
1816  // or may not include space for a pointer to RTTI data.
1817  llvm::GlobalValue *VFTable;
1818  VTable = new llvm::GlobalVariable(CGM.getModule(), VTableType,
1819  /*isConstant=*/true, VTableLinkage,
1820  /*Initializer=*/nullptr, VTableName);
1821  VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1822 
1823  llvm::Comdat *C = nullptr;
1824  if (!VFTableComesFromAnotherTU &&
1825  (llvm::GlobalValue::isWeakForLinker(VFTableLinkage) ||
1826  (llvm::GlobalValue::isLocalLinkage(VFTableLinkage) &&
1827  VTableAliasIsRequred)))
1828  C = CGM.getModule().getOrInsertComdat(VFTableName.str());
1829 
1830  // Only insert a pointer into the VFTable for RTTI data if we are not
1831  // importing it. We never reference the RTTI data directly so there is no
1832  // need to make room for it.
1833  if (VTableAliasIsRequred) {
1834  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.Int32Ty, 0),
1835  llvm::ConstantInt::get(CGM.Int32Ty, 0),
1836  llvm::ConstantInt::get(CGM.Int32Ty, 1)};
1837  // Create a GEP which points just after the first entry in the VFTable,
1838  // this should be the location of the first virtual method.
1839  llvm::Constant *VTableGEP = llvm::ConstantExpr::getInBoundsGetElementPtr(
1840  VTable->getValueType(), VTable, GEPIndices);
1841  if (llvm::GlobalValue::isWeakForLinker(VFTableLinkage)) {
1842  VFTableLinkage = llvm::GlobalValue::ExternalLinkage;
1843  if (C)
1844  C->setSelectionKind(llvm::Comdat::Largest);
1845  }
1846  VFTable = llvm::GlobalAlias::create(CGM.Int8PtrTy,
1847  /*AddressSpace=*/0, VFTableLinkage,
1848  VFTableName.str(), VTableGEP,
1849  &CGM.getModule());
1850  VFTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1851  } else {
1852  // We don't need a GlobalAlias to be a symbol for the VTable if we won't
1853  // be referencing any RTTI data.
1854  // The GlobalVariable will end up being an appropriate definition of the
1855  // VFTable.
1856  VFTable = VTable;
1857  }
1858  if (C)
1859  VTable->setComdat(C);
1860 
1861  if (RD->hasAttr<DLLExportAttr>())
1862  VFTable->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1863 
1864  VFTablesMap[ID] = VFTable;
1865  return VTable;
1866 }
1867 
1868 CGCallee MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
1869  GlobalDecl GD,
1870  Address This,
1871  llvm::Type *Ty,
1872  SourceLocation Loc) {
1873  CGBuilderTy &Builder = CGF.Builder;
1874 
1875  Ty = Ty->getPointerTo()->getPointerTo();
1876  Address VPtr =
1877  adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1878 
1879  auto *MethodDecl = cast<CXXMethodDecl>(GD.getDecl());
1880  llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty, MethodDecl->getParent());
1881 
1882  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1883  MethodVFTableLocation ML = VFTContext.getMethodVFTableLocation(GD);
1884 
1885  // Compute the identity of the most derived class whose virtual table is
1886  // located at the MethodVFTableLocation ML.
1887  auto getObjectWithVPtr = [&] {
1888  return llvm::find_if(VFTContext.getVFPtrOffsets(
1889  ML.VBase ? ML.VBase : MethodDecl->getParent()),
1890  [&](const std::unique_ptr<VPtrInfo> &Info) {
1891  return Info->FullOffsetInMDC == ML.VFPtrOffset;
1892  })
1893  ->get()
1894  ->ObjectWithVPtr;
1895  };
1896 
1897  llvm::Value *VFunc;
1898  if (CGF.ShouldEmitVTableTypeCheckedLoad(MethodDecl->getParent())) {
1899  VFunc = CGF.EmitVTableTypeCheckedLoad(
1900  getObjectWithVPtr(), VTable,
1901  ML.Index * CGM.getContext().getTargetInfo().getPointerWidth(0) / 8);
1902  } else {
1903  if (CGM.getCodeGenOpts().PrepareForLTO)
1904  CGF.EmitTypeMetadataCodeForVCall(getObjectWithVPtr(), VTable, Loc);
1905 
1906  llvm::Value *VFuncPtr =
1907  Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
1908  VFunc = Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
1909  }
1910 
1911  CGCallee Callee(GD, VFunc);
1912  return Callee;
1913 }
1914 
1915 llvm::Value *MicrosoftCXXABI::EmitVirtualDestructorCall(
1916  CodeGenFunction &CGF, const CXXDestructorDecl *Dtor, CXXDtorType DtorType,
1917  Address This, DeleteOrMemberCallExpr E) {
1918  auto *CE = E.dyn_cast<const CXXMemberCallExpr *>();
1919  auto *D = E.dyn_cast<const CXXDeleteExpr *>();
1920  assert((CE != nullptr) ^ (D != nullptr));
1921  assert(CE == nullptr || CE->arg_begin() == CE->arg_end());
1922  assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
1923 
1924  // We have only one destructor in the vftable but can get both behaviors
1925  // by passing an implicit int parameter.
1926  GlobalDecl GD(Dtor, Dtor_Deleting);
1927  const CGFunctionInfo *FInfo =
1928  &CGM.getTypes().arrangeCXXStructorDeclaration(GD);
1929  llvm::FunctionType *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
1930  CGCallee Callee = CGCallee::forVirtual(CE, GD, This, Ty);
1931 
1932  ASTContext &Context = getContext();
1933  llvm::Value *ImplicitParam = llvm::ConstantInt::get(
1934  llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()),
1935  DtorType == Dtor_Deleting);
1936 
1937  QualType ThisTy;
1938  if (CE) {
1939  ThisTy = CE->getObjectType();
1940  } else {
1941  ThisTy = D->getDestroyedType();
1942  }
1943 
1944  This = adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1945  RValue RV = CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
1946  ImplicitParam, Context.IntTy, CE);
1947  return RV.getScalarVal();
1948 }
1949 
1950 const VBTableGlobals &
1951 MicrosoftCXXABI::enumerateVBTables(const CXXRecordDecl *RD) {
1952  // At this layer, we can key the cache off of a single class, which is much
1953  // easier than caching each vbtable individually.
1954  llvm::DenseMap<const CXXRecordDecl*, VBTableGlobals>::iterator Entry;
1955  bool Added;
1956  std::tie(Entry, Added) =
1957  VBTablesMap.insert(std::make_pair(RD, VBTableGlobals()));
1958  VBTableGlobals &VBGlobals = Entry->second;
1959  if (!Added)
1960  return VBGlobals;
1961 
1962  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
1963  VBGlobals.VBTables = &Context.enumerateVBTables(RD);
1964 
1965  // Cache the globals for all vbtables so we don't have to recompute the
1966  // mangled names.
1967  llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
1968  for (VPtrInfoVector::const_iterator I = VBGlobals.VBTables->begin(),
1969  E = VBGlobals.VBTables->end();
1970  I != E; ++I) {
1971  VBGlobals.Globals.push_back(getAddrOfVBTable(**I, RD, Linkage));
1972  }
1973 
1974  return VBGlobals;
1975 }
1976 
1977 llvm::Function *
1978 MicrosoftCXXABI::EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
1979  const MethodVFTableLocation &ML) {
1980  assert(!isa<CXXConstructorDecl>(MD) && !isa<CXXDestructorDecl>(MD) &&
1981  "can't form pointers to ctors or virtual dtors");
1982 
1983  // Calculate the mangled name.
1984  SmallString<256> ThunkName;
1985  llvm::raw_svector_ostream Out(ThunkName);
1986  getMangleContext().mangleVirtualMemPtrThunk(MD, ML, Out);
1987 
1988  // If the thunk has been generated previously, just return it.
1989  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
1990  return cast<llvm::Function>(GV);
1991 
1992  // Create the llvm::Function.
1993  const CGFunctionInfo &FnInfo =
1994  CGM.getTypes().arrangeUnprototypedMustTailThunk(MD);
1995  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
1996  llvm::Function *ThunkFn =
1998  ThunkName.str(), &CGM.getModule());
1999  assert(ThunkFn->getName() == ThunkName && "name was uniqued!");
2000 
2001  ThunkFn->setLinkage(MD->isExternallyVisible()
2002  ? llvm::GlobalValue::LinkOnceODRLinkage
2004  if (MD->isExternallyVisible())
2005  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
2006 
2007  CGM.SetLLVMFunctionAttributes(MD, FnInfo, ThunkFn);
2008  CGM.SetLLVMFunctionAttributesForDefinition(MD, ThunkFn);
2009 
2010  // Add the "thunk" attribute so that LLVM knows that the return type is
2011  // meaningless. These thunks can be used to call functions with differing
2012  // return types, and the caller is required to cast the prototype
2013  // appropriately to extract the correct value.
2014  ThunkFn->addFnAttr("thunk");
2015 
2016  // These thunks can be compared, so they are not unnamed.
2017  ThunkFn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
2018 
2019  // Start codegen.
2020  CodeGenFunction CGF(CGM);
2021  CGF.CurGD = GlobalDecl(MD);
2022  CGF.CurFuncIsThunk = true;
2023 
2024  // Build FunctionArgs, but only include the implicit 'this' parameter
2025  // declaration.
2026  FunctionArgList FunctionArgs;
2027  buildThisParam(CGF, FunctionArgs);
2028 
2029  // Start defining the function.
2030  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
2031  FunctionArgs, MD->getLocation(), SourceLocation());
2032  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
2033 
2034  // Load the vfptr and then callee from the vftable. The callee should have
2035  // adjusted 'this' so that the vfptr is at offset zero.
2036  llvm::Value *VTable = CGF.GetVTablePtr(
2037  getThisAddress(CGF), ThunkTy->getPointerTo()->getPointerTo(), MD->getParent());
2038 
2039  llvm::Value *VFuncPtr =
2040  CGF.Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
2041  llvm::Value *Callee =
2042  CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
2043 
2044  CGF.EmitMustTailThunk(MD, getThisValue(CGF), {ThunkTy, Callee});
2045 
2046  return ThunkFn;
2047 }
2048 
2049 void MicrosoftCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
2050  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
2051  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
2052  const std::unique_ptr<VPtrInfo>& VBT = (*VBGlobals.VBTables)[I];
2053  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
2054  if (GV->isDeclaration())
2055  emitVBTableDefinition(*VBT, RD, GV);
2056  }
2057 }
2058 
2059 llvm::GlobalVariable *
2060 MicrosoftCXXABI::getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
2061  llvm::GlobalVariable::LinkageTypes Linkage) {
2062  SmallString<256> OutName;
2063  llvm::raw_svector_ostream Out(OutName);
2064  getMangleContext().mangleCXXVBTable(RD, VBT.MangledPath, Out);
2065  StringRef Name = OutName.str();
2066 
2067  llvm::ArrayType *VBTableType =
2068  llvm::ArrayType::get(CGM.IntTy, 1 + VBT.ObjectWithVPtr->getNumVBases());
2069 
2070  assert(!CGM.getModule().getNamedGlobal(Name) &&
2071  "vbtable with this name already exists: mangling bug?");
2072  CharUnits Alignment =
2073  CGM.getContext().getTypeAlignInChars(CGM.getContext().IntTy);
2074  llvm::GlobalVariable *GV = CGM.CreateOrReplaceCXXRuntimeVariable(
2075  Name, VBTableType, Linkage, Alignment.getQuantity());
2076  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2077 
2078  if (RD->hasAttr<DLLImportAttr>())
2079  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2080  else if (RD->hasAttr<DLLExportAttr>())
2081  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2082 
2083  if (!GV->hasExternalLinkage())
2084  emitVBTableDefinition(VBT, RD, GV);
2085 
2086  return GV;
2087 }
2088 
2089 void MicrosoftCXXABI::emitVBTableDefinition(const VPtrInfo &VBT,
2090  const CXXRecordDecl *RD,
2091  llvm::GlobalVariable *GV) const {
2092  const CXXRecordDecl *ObjectWithVPtr = VBT.ObjectWithVPtr;
2093 
2094  assert(RD->getNumVBases() && ObjectWithVPtr->getNumVBases() &&
2095  "should only emit vbtables for classes with vbtables");
2096 
2097  const ASTRecordLayout &BaseLayout =
2098  getContext().getASTRecordLayout(VBT.IntroducingObject);
2099  const ASTRecordLayout &DerivedLayout = getContext().getASTRecordLayout(RD);
2100 
2101  SmallVector<llvm::Constant *, 4> Offsets(1 + ObjectWithVPtr->getNumVBases(),
2102  nullptr);
2103 
2104  // The offset from ObjectWithVPtr's vbptr to itself always leads.
2105  CharUnits VBPtrOffset = BaseLayout.getVBPtrOffset();
2106  Offsets[0] = llvm::ConstantInt::get(CGM.IntTy, -VBPtrOffset.getQuantity());
2107 
2108  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
2109  for (const auto &I : ObjectWithVPtr->vbases()) {
2110  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
2111  CharUnits Offset = DerivedLayout.getVBaseClassOffset(VBase);
2112  assert(!Offset.isNegative());
2113 
2114  // Make it relative to the subobject vbptr.
2115  CharUnits CompleteVBPtrOffset = VBT.NonVirtualOffset + VBPtrOffset;
2116  if (VBT.getVBaseWithVPtr())
2117  CompleteVBPtrOffset +=
2118  DerivedLayout.getVBaseClassOffset(VBT.getVBaseWithVPtr());
2119  Offset -= CompleteVBPtrOffset;
2120 
2121  unsigned VBIndex = Context.getVBTableIndex(ObjectWithVPtr, VBase);
2122  assert(Offsets[VBIndex] == nullptr && "The same vbindex seen twice?");
2123  Offsets[VBIndex] = llvm::ConstantInt::get(CGM.IntTy, Offset.getQuantity());
2124  }
2125 
2126  assert(Offsets.size() ==
2127  cast<llvm::ArrayType>(cast<llvm::PointerType>(GV->getType())
2128  ->getElementType())->getNumElements());
2129  llvm::ArrayType *VBTableType =
2130  llvm::ArrayType::get(CGM.IntTy, Offsets.size());
2131  llvm::Constant *Init = llvm::ConstantArray::get(VBTableType, Offsets);
2132  GV->setInitializer(Init);
2133 
2134  if (RD->hasAttr<DLLImportAttr>())
2135  GV->setLinkage(llvm::GlobalVariable::AvailableExternallyLinkage);
2136 }
2137 
2138 llvm::Value *MicrosoftCXXABI::performThisAdjustment(CodeGenFunction &CGF,
2139  Address This,
2140  const ThisAdjustment &TA) {
2141  if (TA.isEmpty())
2142  return This.getPointer();
2143 
2144  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
2145 
2146  llvm::Value *V;
2147  if (TA.Virtual.isEmpty()) {
2148  V = This.getPointer();
2149  } else {
2150  assert(TA.Virtual.Microsoft.VtordispOffset < 0);
2151  // Adjust the this argument based on the vtordisp value.
2152  Address VtorDispPtr =
2155  VtorDispPtr = CGF.Builder.CreateElementBitCast(VtorDispPtr, CGF.Int32Ty);
2156  llvm::Value *VtorDisp = CGF.Builder.CreateLoad(VtorDispPtr, "vtordisp");
2157  V = CGF.Builder.CreateGEP(This.getPointer(),
2158  CGF.Builder.CreateNeg(VtorDisp));
2159 
2160  // Unfortunately, having applied the vtordisp means that we no
2161  // longer really have a known alignment for the vbptr step.
2162  // We'll assume the vbptr is pointer-aligned.
2163 
2164  if (TA.Virtual.Microsoft.VBPtrOffset) {
2165  // If the final overrider is defined in a virtual base other than the one
2166  // that holds the vfptr, we have to use a vtordispex thunk which looks up
2167  // the vbtable of the derived class.
2168  assert(TA.Virtual.Microsoft.VBPtrOffset > 0);
2169  assert(TA.Virtual.Microsoft.VBOffsetOffset >= 0);
2170  llvm::Value *VBPtr;
2171  llvm::Value *VBaseOffset =
2172  GetVBaseOffsetFromVBPtr(CGF, Address(V, CGF.getPointerAlign()),
2174  TA.Virtual.Microsoft.VBOffsetOffset, &VBPtr);
2175  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2176  }
2177  }
2178 
2179  if (TA.NonVirtual) {
2180  // Non-virtual adjustment might result in a pointer outside the allocated
2181  // object, e.g. if the final overrider class is laid out after the virtual
2182  // base that declares a method in the most derived class.
2183  V = CGF.Builder.CreateConstGEP1_32(V, TA.NonVirtual);
2184  }
2185 
2186  // Don't need to bitcast back, the call CodeGen will handle this.
2187  return V;
2188 }
2189 
2190 llvm::Value *
2191 MicrosoftCXXABI::performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
2192  const ReturnAdjustment &RA) {
2193  if (RA.isEmpty())
2194  return Ret.getPointer();
2195 
2196  auto OrigTy = Ret.getType();
2197  Ret = CGF.Builder.CreateElementBitCast(Ret, CGF.Int8Ty);
2198 
2199  llvm::Value *V = Ret.getPointer();
2200  if (RA.Virtual.Microsoft.VBIndex) {
2201  assert(RA.Virtual.Microsoft.VBIndex > 0);
2202  int32_t IntSize = CGF.getIntSize().getQuantity();
2203  llvm::Value *VBPtr;
2204  llvm::Value *VBaseOffset =
2205  GetVBaseOffsetFromVBPtr(CGF, Ret, RA.Virtual.Microsoft.VBPtrOffset,
2206  IntSize * RA.Virtual.Microsoft.VBIndex, &VBPtr);
2207  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2208  }
2209 
2210  if (RA.NonVirtual)
2211  V = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, V, RA.NonVirtual);
2212 
2213  // Cast back to the original type.
2214  return CGF.Builder.CreateBitCast(V, OrigTy);
2215 }
2216 
2217 bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
2218  QualType elementType) {
2219  // Microsoft seems to completely ignore the possibility of a
2220  // two-argument usual deallocation function.
2221  return elementType.isDestructedType();
2222 }
2223 
2224 bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) {
2225  // Microsoft seems to completely ignore the possibility of a
2226  // two-argument usual deallocation function.
2227  return expr->getAllocatedType().isDestructedType();
2228 }
2229 
2230 CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) {
2231  // The array cookie is always a size_t; we then pad that out to the
2232  // alignment of the element type.
2233  ASTContext &Ctx = getContext();
2234  return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
2235  Ctx.getTypeAlignInChars(type));
2236 }
2237 
2238 llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
2239  Address allocPtr,
2240  CharUnits cookieSize) {
2241  Address numElementsPtr =
2242  CGF.Builder.CreateElementBitCast(allocPtr, CGF.SizeTy);
2243  return CGF.Builder.CreateLoad(numElementsPtr);
2244 }
2245 
2246 Address MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
2247  Address newPtr,
2248  llvm::Value *numElements,
2249  const CXXNewExpr *expr,
2250  QualType elementType) {
2251  assert(requiresArrayCookie(expr));
2252 
2253  // The size of the cookie.
2254  CharUnits cookieSize = getArrayCookieSizeImpl(elementType);
2255 
2256  // Compute an offset to the cookie.
2257  Address cookiePtr = newPtr;
2258 
2259  // Write the number of elements into the appropriate slot.
2260  Address numElementsPtr
2261  = CGF.Builder.CreateElementBitCast(cookiePtr, CGF.SizeTy);
2262  CGF.Builder.CreateStore(numElements, numElementsPtr);
2263 
2264  // Finally, compute a pointer to the actual data buffer by skipping
2265  // over the cookie completely.
2266  return CGF.Builder.CreateConstInBoundsByteGEP(newPtr, cookieSize);
2267 }
2268 
2270  llvm::FunctionCallee Dtor,
2271  llvm::Constant *Addr) {
2272  // Create a function which calls the destructor.
2273  llvm::Constant *DtorStub = CGF.createAtExitStub(VD, Dtor, Addr);
2274 
2275  // extern "C" int __tlregdtor(void (*f)(void));
2276  llvm::FunctionType *TLRegDtorTy = llvm::FunctionType::get(
2277  CGF.IntTy, DtorStub->getType(), /*isVarArg=*/false);
2278 
2279  llvm::FunctionCallee TLRegDtor = CGF.CGM.CreateRuntimeFunction(
2280  TLRegDtorTy, "__tlregdtor", llvm::AttributeList(), /*Local=*/true);
2281  if (llvm::Function *TLRegDtorFn =
2282  dyn_cast<llvm::Function>(TLRegDtor.getCallee()))
2283  TLRegDtorFn->setDoesNotThrow();
2284 
2285  CGF.EmitNounwindRuntimeCall(TLRegDtor, DtorStub);
2286 }
2287 
2288 void MicrosoftCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
2289  llvm::FunctionCallee Dtor,
2290  llvm::Constant *Addr) {
2291  if (D.isNoDestroy(CGM.getContext()))
2292  return;
2293 
2294  if (D.getTLSKind())
2295  return emitGlobalDtorWithTLRegDtor(CGF, D, Dtor, Addr);
2296 
2297  // The default behavior is to use atexit.
2298  CGF.registerGlobalDtorWithAtExit(D, Dtor, Addr);
2299 }
2300 
2301 void MicrosoftCXXABI::EmitThreadLocalInitFuncs(
2302  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
2303  ArrayRef<llvm::Function *> CXXThreadLocalInits,
2304  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) {
2305  if (CXXThreadLocalInits.empty())
2306  return;
2307 
2308  CGM.AppendLinkerOptions(CGM.getTarget().getTriple().getArch() ==
2309  llvm::Triple::x86
2310  ? "/include:___dyn_tls_init@12"
2311  : "/include:__dyn_tls_init");
2312 
2313  // This will create a GV in the .CRT$XDU section. It will point to our
2314  // initialization function. The CRT will call all of these function
2315  // pointers at start-up time and, eventually, at thread-creation time.
2316  auto AddToXDU = [&CGM](llvm::Function *InitFunc) {
2317  llvm::GlobalVariable *InitFuncPtr = new llvm::GlobalVariable(
2318  CGM.getModule(), InitFunc->getType(), /*isConstant=*/true,
2320  Twine(InitFunc->getName(), "$initializer$"));
2321  InitFuncPtr->setSection(".CRT$XDU");
2322  // This variable has discardable linkage, we have to add it to @llvm.used to
2323  // ensure it won't get discarded.
2324  CGM.addUsedGlobal(InitFuncPtr);
2325  return InitFuncPtr;
2326  };
2327 
2328  std::vector<llvm::Function *> NonComdatInits;
2329  for (size_t I = 0, E = CXXThreadLocalInitVars.size(); I != E; ++I) {
2330  llvm::GlobalVariable *GV = cast<llvm::GlobalVariable>(
2331  CGM.GetGlobalValue(CGM.getMangledName(CXXThreadLocalInitVars[I])));
2332  llvm::Function *F = CXXThreadLocalInits[I];
2333 
2334  // If the GV is already in a comdat group, then we have to join it.
2335  if (llvm::Comdat *C = GV->getComdat())
2336  AddToXDU(F)->setComdat(C);
2337  else
2338  NonComdatInits.push_back(F);
2339  }
2340 
2341  if (!NonComdatInits.empty()) {
2342  llvm::FunctionType *FTy =
2343  llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
2344  llvm::Function *InitFunc = CGM.CreateGlobalInitOrDestructFunction(
2345  FTy, "__tls_init", CGM.getTypes().arrangeNullaryFunction(),
2346  SourceLocation(), /*TLS=*/true);
2347  CodeGenFunction(CGM).GenerateCXXGlobalInitFunc(InitFunc, NonComdatInits);
2348 
2349  AddToXDU(InitFunc);
2350  }
2351 }
2352 
2353 LValue MicrosoftCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
2354  const VarDecl *VD,
2355  QualType LValType) {
2356  CGF.CGM.ErrorUnsupported(VD, "thread wrappers");
2357  return LValue();
2358 }
2359 
2361  StringRef VarName("_Init_thread_epoch");
2362  CharUnits Align = CGM.getIntAlign();
2363  if (auto *GV = CGM.getModule().getNamedGlobal(VarName))
2364  return ConstantAddress(GV, Align);
2365  auto *GV = new llvm::GlobalVariable(
2366  CGM.getModule(), CGM.IntTy,
2367  /*isConstant=*/false, llvm::GlobalVariable::ExternalLinkage,
2368  /*Initializer=*/nullptr, VarName,
2369  /*InsertBefore=*/nullptr, llvm::GlobalVariable::GeneralDynamicTLSModel);
2370  GV->setAlignment(Align.getAsAlign());
2371  return ConstantAddress(GV, Align);
2372 }
2373 
2374 static llvm::FunctionCallee getInitThreadHeaderFn(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_header",
2380  llvm::AttributeList::get(CGM.getLLVMContext(),
2381  llvm::AttributeList::FunctionIndex,
2382  llvm::Attribute::NoUnwind),
2383  /*Local=*/true);
2384 }
2385 
2386 static llvm::FunctionCallee getInitThreadFooterFn(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_footer",
2392  llvm::AttributeList::get(CGM.getLLVMContext(),
2393  llvm::AttributeList::FunctionIndex,
2394  llvm::Attribute::NoUnwind),
2395  /*Local=*/true);
2396 }
2397 
2398 static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM) {
2399  llvm::FunctionType *FTy =
2400  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2401  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2402  return CGM.CreateRuntimeFunction(
2403  FTy, "_Init_thread_abort",
2404  llvm::AttributeList::get(CGM.getLLVMContext(),
2405  llvm::AttributeList::FunctionIndex,
2406  llvm::Attribute::NoUnwind),
2407  /*Local=*/true);
2408 }
2409 
2410 namespace {
2411 struct ResetGuardBit final : EHScopeStack::Cleanup {
2412  Address Guard;
2413  unsigned GuardNum;
2414  ResetGuardBit(Address Guard, unsigned GuardNum)
2415  : Guard(Guard), GuardNum(GuardNum) {}
2416 
2417  void Emit(CodeGenFunction &CGF, Flags flags) override {
2418  // Reset the bit in the mask so that the static variable may be
2419  // reinitialized.
2420  CGBuilderTy &Builder = CGF.Builder;
2421  llvm::LoadInst *LI = Builder.CreateLoad(Guard);
2422  llvm::ConstantInt *Mask =
2423  llvm::ConstantInt::get(CGF.IntTy, ~(1ULL << GuardNum));
2424  Builder.CreateStore(Builder.CreateAnd(LI, Mask), Guard);
2425  }
2426 };
2427 
2428 struct CallInitThreadAbort final : EHScopeStack::Cleanup {
2429  llvm::Value *Guard;
2430  CallInitThreadAbort(Address Guard) : Guard(Guard.getPointer()) {}
2431 
2432  void Emit(CodeGenFunction &CGF, Flags flags) override {
2433  // Calling _Init_thread_abort will reset the guard's state.
2435  }
2436 };
2437 }
2438 
2439 void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
2440  llvm::GlobalVariable *GV,
2441  bool PerformInit) {
2442  // MSVC only uses guards for static locals.
2443  if (!D.isStaticLocal()) {
2444  assert(GV->hasWeakLinkage() || GV->hasLinkOnceLinkage());
2445  // GlobalOpt is allowed to discard the initializer, so use linkonce_odr.
2446  llvm::Function *F = CGF.CurFn;
2447  F->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
2448  F->setComdat(CGM.getModule().getOrInsertComdat(F->getName()));
2449  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2450  return;
2451  }
2452 
2453  bool ThreadlocalStatic = D.getTLSKind();
2454  bool ThreadsafeStatic = getContext().getLangOpts().ThreadsafeStatics;
2455 
2456  // Thread-safe static variables which aren't thread-specific have a
2457  // per-variable guard.
2458  bool HasPerVariableGuard = ThreadsafeStatic && !ThreadlocalStatic;
2459 
2460  CGBuilderTy &Builder = CGF.Builder;
2461  llvm::IntegerType *GuardTy = CGF.Int32Ty;
2462  llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0);
2463  CharUnits GuardAlign = CharUnits::fromQuantity(4);
2464 
2465  // Get the guard variable for this function if we have one already.
2466  GuardInfo *GI = nullptr;
2467  if (ThreadlocalStatic)
2468  GI = &ThreadLocalGuardVariableMap[D.getDeclContext()];
2469  else if (!ThreadsafeStatic)
2470  GI = &GuardVariableMap[D.getDeclContext()];
2471 
2472  llvm::GlobalVariable *GuardVar = GI ? GI->Guard : nullptr;
2473  unsigned GuardNum;
2474  if (D.isExternallyVisible()) {
2475  // Externally visible variables have to be numbered in Sema to properly
2476  // handle unreachable VarDecls.
2477  GuardNum = getContext().getStaticLocalNumber(&D);
2478  assert(GuardNum > 0);
2479  GuardNum--;
2480  } else if (HasPerVariableGuard) {
2481  GuardNum = ThreadSafeGuardNumMap[D.getDeclContext()]++;
2482  } else {
2483  // Non-externally visible variables are numbered here in CodeGen.
2484  GuardNum = GI->BitIndex++;
2485  }
2486 
2487  if (!HasPerVariableGuard && GuardNum >= 32) {
2488  if (D.isExternallyVisible())
2489  ErrorUnsupportedABI(CGF, "more than 32 guarded initializations");
2490  GuardNum %= 32;
2491  GuardVar = nullptr;
2492  }
2493 
2494  if (!GuardVar) {
2495  // Mangle the name for the guard.
2496  SmallString<256> GuardName;
2497  {
2498  llvm::raw_svector_ostream Out(GuardName);
2499  if (HasPerVariableGuard)
2500  getMangleContext().mangleThreadSafeStaticGuardVariable(&D, GuardNum,
2501  Out);
2502  else
2503  getMangleContext().mangleStaticGuardVariable(&D, Out);
2504  }
2505 
2506  // Create the guard variable with a zero-initializer. Just absorb linkage,
2507  // visibility and dll storage class from the guarded variable.
2508  GuardVar =
2509  new llvm::GlobalVariable(CGM.getModule(), GuardTy, /*isConstant=*/false,
2510  GV->getLinkage(), Zero, GuardName.str());
2511  GuardVar->setVisibility(GV->getVisibility());
2512  GuardVar->setDLLStorageClass(GV->getDLLStorageClass());
2513  GuardVar->setAlignment(GuardAlign.getAsAlign());
2514  if (GuardVar->isWeakForLinker())
2515  GuardVar->setComdat(
2516  CGM.getModule().getOrInsertComdat(GuardVar->getName()));
2517  if (D.getTLSKind())
2518  GuardVar->setThreadLocal(true);
2519  if (GI && !HasPerVariableGuard)
2520  GI->Guard = GuardVar;
2521  }
2522 
2523  ConstantAddress GuardAddr(GuardVar, GuardAlign);
2524 
2525  assert(GuardVar->getLinkage() == GV->getLinkage() &&
2526  "static local from the same function had different linkage");
2527 
2528  if (!HasPerVariableGuard) {
2529  // Pseudo code for the test:
2530  // if (!(GuardVar & MyGuardBit)) {
2531  // GuardVar |= MyGuardBit;
2532  // ... initialize the object ...;
2533  // }
2534 
2535  // Test our bit from the guard variable.
2536  llvm::ConstantInt *Bit = llvm::ConstantInt::get(GuardTy, 1ULL << GuardNum);
2537  llvm::LoadInst *LI = Builder.CreateLoad(GuardAddr);
2538  llvm::Value *NeedsInit =
2539  Builder.CreateICmpEQ(Builder.CreateAnd(LI, Bit), Zero);
2540  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2541  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2542  CGF.EmitCXXGuardedInitBranch(NeedsInit, InitBlock, EndBlock,
2544 
2545  // Set our bit in the guard variable and emit the initializer and add a global
2546  // destructor if appropriate.
2547  CGF.EmitBlock(InitBlock);
2548  Builder.CreateStore(Builder.CreateOr(LI, Bit), GuardAddr);
2549  CGF.EHStack.pushCleanup<ResetGuardBit>(EHCleanup, GuardAddr, GuardNum);
2550  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2551  CGF.PopCleanupBlock();
2552  Builder.CreateBr(EndBlock);
2553 
2554  // Continue.
2555  CGF.EmitBlock(EndBlock);
2556  } else {
2557  // Pseudo code for the test:
2558  // if (TSS > _Init_thread_epoch) {
2559  // _Init_thread_header(&TSS);
2560  // if (TSS == -1) {
2561  // ... initialize the object ...;
2562  // _Init_thread_footer(&TSS);
2563  // }
2564  // }
2565  //
2566  // The algorithm is almost identical to what can be found in the appendix
2567  // found in N2325.
2568 
2569  // This BasicBLock determines whether or not we have any work to do.
2570  llvm::LoadInst *FirstGuardLoad = Builder.CreateLoad(GuardAddr);
2571  FirstGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2572  llvm::LoadInst *InitThreadEpoch =
2573  Builder.CreateLoad(getInitThreadEpochPtr(CGM));
2574  llvm::Value *IsUninitialized =
2575  Builder.CreateICmpSGT(FirstGuardLoad, InitThreadEpoch);
2576  llvm::BasicBlock *AttemptInitBlock = CGF.createBasicBlock("init.attempt");
2577  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2578  CGF.EmitCXXGuardedInitBranch(IsUninitialized, AttemptInitBlock, EndBlock,
2580 
2581  // This BasicBlock attempts to determine whether or not this thread is
2582  // responsible for doing the initialization.
2583  CGF.EmitBlock(AttemptInitBlock);
2585  GuardAddr.getPointer());
2586  llvm::LoadInst *SecondGuardLoad = Builder.CreateLoad(GuardAddr);
2587  SecondGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2588  llvm::Value *ShouldDoInit =
2589  Builder.CreateICmpEQ(SecondGuardLoad, getAllOnesInt());
2590  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2591  Builder.CreateCondBr(ShouldDoInit, InitBlock, EndBlock);
2592 
2593  // Ok, we ended up getting selected as the initializing thread.
2594  CGF.EmitBlock(InitBlock);
2595  CGF.EHStack.pushCleanup<CallInitThreadAbort>(EHCleanup, GuardAddr);
2596  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2597  CGF.PopCleanupBlock();
2599  GuardAddr.getPointer());
2600  Builder.CreateBr(EndBlock);
2601 
2602  CGF.EmitBlock(EndBlock);
2603  }
2604 }
2605 
2606 bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
2607  // Null-ness for function memptrs only depends on the first field, which is
2608  // the function pointer. The rest don't matter, so we can zero initialize.
2609  if (MPT->isMemberFunctionPointer())
2610  return true;
2611 
2612  // The virtual base adjustment field is always -1 for null, so if we have one
2613  // we can't zero initialize. The field offset is sometimes also -1 if 0 is a
2614  // valid field offset.
2615  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2616  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
2617  return (!inheritanceModelHasVBTableOffsetField(Inheritance) &&
2618  RD->nullFieldOffsetIsZero());
2619 }
2620 
2621 llvm::Type *
2622 MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
2623  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2624  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
2626  if (MPT->isMemberFunctionPointer())
2627  fields.push_back(CGM.VoidPtrTy); // FunctionPointerOrVirtualThunk
2628  else
2629  fields.push_back(CGM.IntTy); // FieldOffset
2630 
2632  Inheritance))
2633  fields.push_back(CGM.IntTy);
2634  if (inheritanceModelHasVBPtrOffsetField(Inheritance))
2635  fields.push_back(CGM.IntTy);
2636  if (inheritanceModelHasVBTableOffsetField(Inheritance))
2637  fields.push_back(CGM.IntTy); // VirtualBaseAdjustmentOffset
2638 
2639  if (fields.size() == 1)
2640  return fields[0];
2641  return llvm::StructType::get(CGM.getLLVMContext(), fields);
2642 }
2643 
2644 void MicrosoftCXXABI::
2645 GetNullMemberPointerFields(const MemberPointerType *MPT,
2647  assert(fields.empty());
2648  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2649  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
2650  if (MPT->isMemberFunctionPointer()) {
2651  // FunctionPointerOrVirtualThunk
2652  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2653  } else {
2654  if (RD->nullFieldOffsetIsZero())
2655  fields.push_back(getZeroInt()); // FieldOffset
2656  else
2657  fields.push_back(getAllOnesInt()); // FieldOffset
2658  }
2659 
2661  Inheritance))
2662  fields.push_back(getZeroInt());
2663  if (inheritanceModelHasVBPtrOffsetField(Inheritance))
2664  fields.push_back(getZeroInt());
2665  if (inheritanceModelHasVBTableOffsetField(Inheritance))
2666  fields.push_back(getAllOnesInt());
2667 }
2668 
2669 llvm::Constant *
2670 MicrosoftCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
2672  GetNullMemberPointerFields(MPT, fields);
2673  if (fields.size() == 1)
2674  return fields[0];
2675  llvm::Constant *Res = llvm::ConstantStruct::getAnon(fields);
2676  assert(Res->getType() == ConvertMemberPointerType(MPT));
2677  return Res;
2678 }
2679 
2680 llvm::Constant *
2681 MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
2682  bool IsMemberFunction,
2683  const CXXRecordDecl *RD,
2684  CharUnits NonVirtualBaseAdjustment,
2685  unsigned VBTableIndex) {
2686  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
2687 
2688  // Single inheritance class member pointer are represented as scalars instead
2689  // of aggregates.
2690  if (inheritanceModelHasOnlyOneField(IsMemberFunction, Inheritance))
2691  return FirstField;
2692 
2694  fields.push_back(FirstField);
2695 
2696  if (inheritanceModelHasNVOffsetField(IsMemberFunction, Inheritance))
2697  fields.push_back(llvm::ConstantInt::get(
2698  CGM.IntTy, NonVirtualBaseAdjustment.getQuantity()));
2699 
2700  if (inheritanceModelHasVBPtrOffsetField(Inheritance)) {
2701  CharUnits Offs = CharUnits::Zero();
2702  if (VBTableIndex)
2703  Offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
2704  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, Offs.getQuantity()));
2705  }
2706 
2707  // The rest of the fields are adjusted by conversions to a more derived class.
2708  if (inheritanceModelHasVBTableOffsetField(Inheritance))
2709  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBTableIndex));
2710 
2711  return llvm::ConstantStruct::getAnon(fields);
2712 }
2713 
2714 llvm::Constant *
2715 MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
2716  CharUnits offset) {
2717  return EmitMemberDataPointer(MPT->getMostRecentCXXRecordDecl(), offset);
2718 }
2719 
2720 llvm::Constant *MicrosoftCXXABI::EmitMemberDataPointer(const CXXRecordDecl *RD,
2721  CharUnits offset) {
2722  if (RD->getMSInheritanceModel() ==
2724  offset -= getContext().getOffsetOfBaseWithVBPtr(RD);
2725  llvm::Constant *FirstField =
2726  llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity());
2727  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD,
2728  CharUnits::Zero(), /*VBTableIndex=*/0);
2729 }
2730 
2731 llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP,
2732  QualType MPType) {
2733  const MemberPointerType *DstTy = MPType->castAs<MemberPointerType>();
2734  const ValueDecl *MPD = MP.getMemberPointerDecl();
2735  if (!MPD)
2736  return EmitNullMemberPointer(DstTy);
2737 
2738  ASTContext &Ctx = getContext();
2739  ArrayRef<const CXXRecordDecl *> MemberPointerPath = MP.getMemberPointerPath();
2740 
2741  llvm::Constant *C;
2742  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) {
2743  C = EmitMemberFunctionPointer(MD);
2744  } else {
2745  // For a pointer to data member, start off with the offset of the field in
2746  // the class in which it was declared, and convert from there if necessary.
2747  // For indirect field decls, get the outermost anonymous field and use the
2748  // parent class.
2749  CharUnits FieldOffset = Ctx.toCharUnitsFromBits(Ctx.getFieldOffset(MPD));
2750  const FieldDecl *FD = dyn_cast<FieldDecl>(MPD);
2751  if (!FD)
2752  FD = cast<FieldDecl>(*cast<IndirectFieldDecl>(MPD)->chain_begin());
2753  const CXXRecordDecl *RD = cast<CXXRecordDecl>(FD->getParent());
2754  RD = RD->getMostRecentNonInjectedDecl();
2755  C = EmitMemberDataPointer(RD, FieldOffset);
2756  }
2757 
2758  if (!MemberPointerPath.empty()) {
2759  const CXXRecordDecl *SrcRD = cast<CXXRecordDecl>(MPD->getDeclContext());
2760  const Type *SrcRecTy = Ctx.getTypeDeclType(SrcRD).getTypePtr();
2761  const MemberPointerType *SrcTy =
2762  Ctx.getMemberPointerType(DstTy->getPointeeType(), SrcRecTy)
2763  ->castAs<MemberPointerType>();
2764 
2765  bool DerivedMember = MP.isMemberPointerToDerivedMember();
2766  SmallVector<const CXXBaseSpecifier *, 4> DerivedToBasePath;
2767  const CXXRecordDecl *PrevRD = SrcRD;
2768  for (const CXXRecordDecl *PathElem : MemberPointerPath) {
2769  const CXXRecordDecl *Base = nullptr;
2770  const CXXRecordDecl *Derived = nullptr;
2771  if (DerivedMember) {
2772  Base = PathElem;
2773  Derived = PrevRD;
2774  } else {
2775  Base = PrevRD;
2776  Derived = PathElem;
2777  }
2778  for (const CXXBaseSpecifier &BS : Derived->bases())
2779  if (BS.getType()->getAsCXXRecordDecl()->getCanonicalDecl() ==
2780  Base->getCanonicalDecl())
2781  DerivedToBasePath.push_back(&BS);
2782  PrevRD = PathElem;
2783  }
2784  assert(DerivedToBasePath.size() == MemberPointerPath.size());
2785 
2786  CastKind CK = DerivedMember ? CK_DerivedToBaseMemberPointer
2787  : CK_BaseToDerivedMemberPointer;
2788  C = EmitMemberPointerConversion(SrcTy, DstTy, CK, DerivedToBasePath.begin(),
2789  DerivedToBasePath.end(), C);
2790  }
2791  return C;
2792 }
2793 
2794 llvm::Constant *
2795 MicrosoftCXXABI::EmitMemberFunctionPointer(const CXXMethodDecl *MD) {
2796  assert(MD->isInstance() && "Member function must not be static!");
2797 
2798  CharUnits NonVirtualBaseAdjustment = CharUnits::Zero();
2800  CodeGenTypes &Types = CGM.getTypes();
2801 
2802  unsigned VBTableIndex = 0;
2803  llvm::Constant *FirstField;
2804  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
2805  if (!MD->isVirtual()) {
2806  llvm::Type *Ty;
2807  // Check whether the function has a computable LLVM signature.
2808  if (Types.isFuncTypeConvertible(FPT)) {
2809  // The function has a computable LLVM signature; use the correct type.
2810  Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD));
2811  } else {
2812  // Use an arbitrary non-function type to tell GetAddrOfFunction that the
2813  // function type is incomplete.
2814  Ty = CGM.PtrDiffTy;
2815  }
2816  FirstField = CGM.GetAddrOfFunction(MD, Ty);
2817  } else {
2818  auto &VTableContext = CGM.getMicrosoftVTableContext();
2819  MethodVFTableLocation ML = VTableContext.getMethodVFTableLocation(MD);
2820  FirstField = EmitVirtualMemPtrThunk(MD, ML);
2821  // Include the vfptr adjustment if the method is in a non-primary vftable.
2822  NonVirtualBaseAdjustment += ML.VFPtrOffset;
2823  if (ML.VBase)
2824  VBTableIndex = VTableContext.getVBTableIndex(RD, ML.VBase) * 4;
2825  }
2826 
2827  if (VBTableIndex == 0 &&
2828  RD->getMSInheritanceModel() ==
2830  NonVirtualBaseAdjustment -= getContext().getOffsetOfBaseWithVBPtr(RD);
2831 
2832  // The rest of the fields are common with data member pointers.
2833  FirstField = llvm::ConstantExpr::getBitCast(FirstField, CGM.VoidPtrTy);
2834  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD,
2835  NonVirtualBaseAdjustment, VBTableIndex);
2836 }
2837 
2838 /// Member pointers are the same if they're either bitwise identical *or* both
2839 /// null. Null-ness for function members is determined by the first field,
2840 /// while for data member pointers we must compare all fields.
2841 llvm::Value *
2842 MicrosoftCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
2843  llvm::Value *L,
2844  llvm::Value *R,
2845  const MemberPointerType *MPT,
2846  bool Inequality) {
2847  CGBuilderTy &Builder = CGF.Builder;
2848 
2849  // Handle != comparisons by switching the sense of all boolean operations.
2850  llvm::ICmpInst::Predicate Eq;
2851  llvm::Instruction::BinaryOps And, Or;
2852  if (Inequality) {
2853  Eq = llvm::ICmpInst::ICMP_NE;
2854  And = llvm::Instruction::Or;
2856  } else {
2857  Eq = llvm::ICmpInst::ICMP_EQ;
2858  And = llvm::Instruction::And;
2859  Or = llvm::Instruction::Or;
2860  }
2861 
2862  // If this is a single field member pointer (single inheritance), this is a
2863  // single icmp.
2864  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2865  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
2867  Inheritance))
2868  return Builder.CreateICmp(Eq, L, R);
2869 
2870  // Compare the first field.
2871  llvm::Value *L0 = Builder.CreateExtractValue(L, 0, "lhs.0");
2872  llvm::Value *R0 = Builder.CreateExtractValue(R, 0, "rhs.0");
2873  llvm::Value *Cmp0 = Builder.CreateICmp(Eq, L0, R0, "memptr.cmp.first");
2874 
2875  // Compare everything other than the first field.
2876  llvm::Value *Res = nullptr;
2877  llvm::StructType *LType = cast<llvm::StructType>(L->getType());
2878  for (unsigned I = 1, E = LType->getNumElements(); I != E; ++I) {
2879  llvm::Value *LF = Builder.CreateExtractValue(L, I);
2880  llvm::Value *RF = Builder.CreateExtractValue(R, I);
2881  llvm::Value *Cmp = Builder.CreateICmp(Eq, LF, RF, "memptr.cmp.rest");
2882  if (Res)
2883  Res = Builder.CreateBinOp(And, Res, Cmp);
2884  else
2885  Res = Cmp;
2886  }
2887 
2888  // Check if the first field is 0 if this is a function pointer.
2889  if (MPT->isMemberFunctionPointer()) {
2890  // (l1 == r1 && ...) || l0 == 0
2891  llvm::Value *Zero = llvm::Constant::getNullValue(L0->getType());
2892  llvm::Value *IsZero = Builder.CreateICmp(Eq, L0, Zero, "memptr.cmp.iszero");
2893  Res = Builder.CreateBinOp(Or, Res, IsZero);
2894  }
2895 
2896  // Combine the comparison of the first field, which must always be true for
2897  // this comparison to succeeed.
2898  return Builder.CreateBinOp(And, Res, Cmp0, "memptr.cmp");
2899 }
2900 
2901 llvm::Value *
2902 MicrosoftCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
2903  llvm::Value *MemPtr,
2904  const MemberPointerType *MPT) {
2905  CGBuilderTy &Builder = CGF.Builder;
2907  // We only need one field for member functions.
2908  if (MPT->isMemberFunctionPointer())
2909  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2910  else
2911  GetNullMemberPointerFields(MPT, fields);
2912  assert(!fields.empty());
2913  llvm::Value *FirstField = MemPtr;
2914  if (MemPtr->getType()->isStructTy())
2915  FirstField = Builder.CreateExtractValue(MemPtr, 0);
2916  llvm::Value *Res = Builder.CreateICmpNE(FirstField, fields[0], "memptr.cmp0");
2917 
2918  // For function member pointers, we only need to test the function pointer
2919  // field. The other fields if any can be garbage.
2920  if (MPT->isMemberFunctionPointer())
2921  return Res;
2922 
2923  // Otherwise, emit a series of compares and combine the results.
2924  for (int I = 1, E = fields.size(); I < E; ++I) {
2925  llvm::Value *Field = Builder.CreateExtractValue(MemPtr, I);
2926  llvm::Value *Next = Builder.CreateICmpNE(Field, fields[I], "memptr.cmp");
2927  Res = Builder.CreateOr(Res, Next, "memptr.tobool");
2928  }
2929  return Res;
2930 }
2931 
2932 bool MicrosoftCXXABI::MemberPointerConstantIsNull(const MemberPointerType *MPT,
2933  llvm::Constant *Val) {
2934  // Function pointers are null if the pointer in the first field is null.
2935  if (MPT->isMemberFunctionPointer()) {
2936  llvm::Constant *FirstField = Val->getType()->isStructTy() ?
2937  Val->getAggregateElement(0U) : Val;
2938  return FirstField->isNullValue();
2939  }
2940 
2941  // If it's not a function pointer and it's zero initializable, we can easily
2942  // check zero.
2943  if (isZeroInitializable(MPT) && Val->isNullValue())
2944  return true;
2945 
2946  // Otherwise, break down all the fields for comparison. Hopefully these
2947  // little Constants are reused, while a big null struct might not be.
2949  GetNullMemberPointerFields(MPT, Fields);
2950  if (Fields.size() == 1) {
2951  assert(Val->getType()->isIntegerTy());
2952  return Val == Fields[0];
2953  }
2954 
2955  unsigned I, E;
2956  for (I = 0, E = Fields.size(); I != E; ++I) {
2957  if (Val->getAggregateElement(I) != Fields[I])
2958  break;
2959  }
2960  return I == E;
2961 }
2962 
2963 llvm::Value *
2964 MicrosoftCXXABI::GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
2965  Address This,
2966  llvm::Value *VBPtrOffset,
2967  llvm::Value *VBTableOffset,
2968  llvm::Value **VBPtrOut) {
2969  CGBuilderTy &Builder = CGF.Builder;
2970  // Load the vbtable pointer from the vbptr in the instance.
2971  This = Builder.CreateElementBitCast(This, CGM.Int8Ty);
2972  llvm::Value *VBPtr =
2973  Builder.CreateInBoundsGEP(This.getPointer(), VBPtrOffset, "vbptr");
2974  if (VBPtrOut) *VBPtrOut = VBPtr;
2975  VBPtr = Builder.CreateBitCast(VBPtr,
2976  CGM.Int32Ty->getPointerTo(0)->getPointerTo(This.getAddressSpace()));
2977 
2978  CharUnits VBPtrAlign;
2979  if (auto CI = dyn_cast<llvm::ConstantInt>(VBPtrOffset)) {
2980  VBPtrAlign = This.getAlignment().alignmentAtOffset(
2981  CharUnits::fromQuantity(CI->getSExtValue()));
2982  } else {
2983  VBPtrAlign = CGF.getPointerAlign();
2984  }
2985 
2986  llvm::Value *VBTable = Builder.CreateAlignedLoad(VBPtr, VBPtrAlign, "vbtable");
2987 
2988  // Translate from byte offset to table index. It improves analyzability.
2989  llvm::Value *VBTableIndex = Builder.CreateAShr(
2990  VBTableOffset, llvm::ConstantInt::get(VBTableOffset->getType(), 2),
2991  "vbtindex", /*isExact=*/true);
2992 
2993  // Load an i32 offset from the vb-table.
2994  llvm::Value *VBaseOffs = Builder.CreateInBoundsGEP(VBTable, VBTableIndex);
2995  VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0));
2996  return Builder.CreateAlignedLoad(VBaseOffs, CharUnits::fromQuantity(4),
2997  "vbase_offs");
2998 }
2999 
3000 // Returns an adjusted base cast to i8*, since we do more address arithmetic on
3001 // it.
3002 llvm::Value *MicrosoftCXXABI::AdjustVirtualBase(
3003  CodeGenFunction &CGF, const Expr *E, const CXXRecordDecl *RD,
3004  Address Base, llvm::Value *VBTableOffset, llvm::Value *VBPtrOffset) {
3005  CGBuilderTy &Builder = CGF.Builder;
3006  Base = Builder.CreateElementBitCast(Base, CGM.Int8Ty);
3007  llvm::BasicBlock *OriginalBB = nullptr;
3008  llvm::BasicBlock *SkipAdjustBB = nullptr;
3009  llvm::BasicBlock *VBaseAdjustBB = nullptr;
3010 
3011  // In the unspecified inheritance model, there might not be a vbtable at all,
3012  // in which case we need to skip the virtual base lookup. If there is a
3013  // vbtable, the first entry is a no-op entry that gives back the original
3014  // base, so look for a virtual base adjustment offset of zero.
3015  if (VBPtrOffset) {
3016  OriginalBB = Builder.GetInsertBlock();
3017  VBaseAdjustBB = CGF.createBasicBlock("memptr.vadjust");
3018  SkipAdjustBB = CGF.createBasicBlock("memptr.skip_vadjust");
3019  llvm::Value *IsVirtual =
3020  Builder.CreateICmpNE(VBTableOffset, getZeroInt(),
3021  "memptr.is_vbase");
3022  Builder.CreateCondBr(IsVirtual, VBaseAdjustBB, SkipAdjustBB);
3023  CGF.EmitBlock(VBaseAdjustBB);
3024  }
3025 
3026  // If we weren't given a dynamic vbptr offset, RD should be complete and we'll
3027  // know the vbptr offset.
3028  if (!VBPtrOffset) {
3029  CharUnits offs = CharUnits::Zero();
3030  if (!RD->hasDefinition()) {
3031  DiagnosticsEngine &Diags = CGF.CGM.getDiags();
3032  unsigned DiagID = Diags.getCustomDiagID(
3034  "member pointer representation requires a "
3035  "complete class type for %0 to perform this expression");
3036  Diags.Report(E->getExprLoc(), DiagID) << RD << E->getSourceRange();
3037  } else if (RD->getNumVBases())
3038  offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
3039  VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity());
3040  }
3041  llvm::Value *VBPtr = nullptr;
3042  llvm::Value *VBaseOffs =
3043  GetVBaseOffsetFromVBPtr(CGF, Base, VBPtrOffset, VBTableOffset, &VBPtr);
3044  llvm::Value *AdjustedBase = Builder.CreateInBoundsGEP(VBPtr, VBaseOffs);
3045 
3046  // Merge control flow with the case where we didn't have to adjust.
3047  if (VBaseAdjustBB) {
3048  Builder.CreateBr(SkipAdjustBB);
3049  CGF.EmitBlock(SkipAdjustBB);
3050  llvm::PHINode *Phi = Builder.CreatePHI(CGM.Int8PtrTy, 2, "memptr.base");
3051  Phi->addIncoming(Base.getPointer(), OriginalBB);
3052  Phi->addIncoming(AdjustedBase, VBaseAdjustBB);
3053  return Phi;
3054  }
3055  return AdjustedBase;
3056 }
3057 
3058 llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
3059  CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
3060  const MemberPointerType *MPT) {
3061  assert(MPT->isMemberDataPointer());
3062  unsigned AS = Base.getAddressSpace();
3063  llvm::Type *PType =
3064  CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
3065  CGBuilderTy &Builder = CGF.Builder;
3066  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
3067  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
3068 
3069  // Extract the fields we need, regardless of model. We'll apply them if we
3070  // have them.
3071  llvm::Value *FieldOffset = MemPtr;
3072  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
3073  llvm::Value *VBPtrOffset = nullptr;
3074  if (MemPtr->getType()->isStructTy()) {
3075  // We need to extract values.
3076  unsigned I = 0;
3077  FieldOffset = Builder.CreateExtractValue(MemPtr, I++);
3078  if (inheritanceModelHasVBPtrOffsetField(Inheritance))
3079  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
3080  if (inheritanceModelHasVBTableOffsetField(Inheritance))
3081  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
3082  }
3083 
3084  llvm::Value *Addr;
3085  if (VirtualBaseAdjustmentOffset) {
3086  Addr = AdjustVirtualBase(CGF, E, RD, Base, VirtualBaseAdjustmentOffset,
3087  VBPtrOffset);
3088  } else {
3089  Addr = Base.getPointer();
3090  }
3091 
3092  // Cast to char*.
3093  Addr = Builder.CreateBitCast(Addr, CGF.Int8Ty->getPointerTo(AS));
3094 
3095  // Apply the offset, which we assume is non-null.
3096  Addr = Builder.CreateInBoundsGEP(Addr, FieldOffset, "memptr.offset");
3097 
3098  // Cast the address to the appropriate pointer type, adopting the address
3099  // space of the base pointer.
3100  return Builder.CreateBitCast(Addr, PType);
3101 }
3102 
3103 llvm::Value *
3104 MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
3105  const CastExpr *E,
3106  llvm::Value *Src) {
3107  assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
3108  E->getCastKind() == CK_BaseToDerivedMemberPointer ||
3109  E->getCastKind() == CK_ReinterpretMemberPointer);
3110 
3111  // Use constant emission if we can.
3112  if (isa<llvm::Constant>(Src))
3113  return EmitMemberPointerConversion(E, cast<llvm::Constant>(Src));
3114 
3115  // We may be adding or dropping fields from the member pointer, so we need
3116  // both types and the inheritance models of both records.
3117  const MemberPointerType *SrcTy =
3119  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3120  bool IsFunc = SrcTy->isMemberFunctionPointer();
3121 
3122  // If the classes use the same null representation, reinterpret_cast is a nop.
3123  bool IsReinterpret = E->getCastKind() == CK_ReinterpretMemberPointer;
3124  if (IsReinterpret && IsFunc)
3125  return Src;
3126 
3127  CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3128  CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3129  if (IsReinterpret &&
3130  SrcRD->nullFieldOffsetIsZero() == DstRD->nullFieldOffsetIsZero())
3131  return Src;
3132 
3133  CGBuilderTy &Builder = CGF.Builder;
3134 
3135  // Branch past the conversion if Src is null.
3136  llvm::Value *IsNotNull = EmitMemberPointerIsNotNull(CGF, Src, SrcTy);
3137  llvm::Constant *DstNull = EmitNullMemberPointer(DstTy);
3138 
3139  // C++ 5.2.10p9: The null member pointer value is converted to the null member
3140  // pointer value of the destination type.
3141  if (IsReinterpret) {
3142  // For reinterpret casts, sema ensures that src and dst are both functions
3143  // or data and have the same size, which means the LLVM types should match.
3144  assert(Src->getType() == DstNull->getType());
3145  return Builder.CreateSelect(IsNotNull, Src, DstNull);
3146  }
3147 
3148  llvm::BasicBlock *OriginalBB = Builder.GetInsertBlock();
3149  llvm::BasicBlock *ConvertBB = CGF.createBasicBlock("memptr.convert");
3150  llvm::BasicBlock *ContinueBB = CGF.createBasicBlock("memptr.converted");
3151  Builder.CreateCondBr(IsNotNull, ConvertBB, ContinueBB);
3152  CGF.EmitBlock(ConvertBB);
3153 
3154  llvm::Value *Dst = EmitNonNullMemberPointerConversion(
3155  SrcTy, DstTy, E->getCastKind(), E->path_begin(), E->path_end(), Src,
3156  Builder);
3157 
3158  Builder.CreateBr(ContinueBB);
3159 
3160  // In the continuation, choose between DstNull and Dst.
3161  CGF.EmitBlock(ContinueBB);
3162  llvm::PHINode *Phi = Builder.CreatePHI(DstNull->getType(), 2, "memptr.converted");
3163  Phi->addIncoming(DstNull, OriginalBB);
3164  Phi->addIncoming(Dst, ConvertBB);
3165  return Phi;
3166 }
3167 
3168 llvm::Value *MicrosoftCXXABI::EmitNonNullMemberPointerConversion(
3169  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3172  CGBuilderTy &Builder) {
3173  const CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3174  const CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3175  MSInheritanceModel SrcInheritance = SrcRD->getMSInheritanceModel();
3176  MSInheritanceModel DstInheritance = DstRD->getMSInheritanceModel();
3177  bool IsFunc = SrcTy->isMemberFunctionPointer();
3178  bool IsConstant = isa<llvm::Constant>(Src);
3179 
3180  // Decompose src.
3181  llvm::Value *FirstField = Src;
3182  llvm::Value *NonVirtualBaseAdjustment = getZeroInt();
3183  llvm::Value *VirtualBaseAdjustmentOffset = getZeroInt();
3184  llvm::Value *VBPtrOffset = getZeroInt();
3185  if (!inheritanceModelHasOnlyOneField(IsFunc, SrcInheritance)) {
3186  // We need to extract values.
3187  unsigned I = 0;
3188  FirstField = Builder.CreateExtractValue(Src, I++);
3189  if (inheritanceModelHasNVOffsetField(IsFunc, SrcInheritance))
3190  NonVirtualBaseAdjustment = Builder.CreateExtractValue(Src, I++);
3191  if (inheritanceModelHasVBPtrOffsetField(SrcInheritance))
3192  VBPtrOffset = Builder.CreateExtractValue(Src, I++);
3193  if (inheritanceModelHasVBTableOffsetField(SrcInheritance))
3194  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(Src, I++);
3195  }
3196 
3197  bool IsDerivedToBase = (CK == CK_DerivedToBaseMemberPointer);
3198  const MemberPointerType *DerivedTy = IsDerivedToBase ? SrcTy : DstTy;
3199  const CXXRecordDecl *DerivedClass = DerivedTy->getMostRecentCXXRecordDecl();
3200 
3201  // For data pointers, we adjust the field offset directly. For functions, we
3202  // have a separate field.
3203  llvm::Value *&NVAdjustField = IsFunc ? NonVirtualBaseAdjustment : FirstField;
3204 
3205  // The virtual inheritance model has a quirk: the virtual base table is always
3206  // referenced when dereferencing a member pointer even if the member pointer
3207  // is non-virtual. This is accounted for by adjusting the non-virtual offset
3208  // to point backwards to the top of the MDC from the first VBase. Undo this
3209  // adjustment to normalize the member pointer.
3210  llvm::Value *SrcVBIndexEqZero =
3211  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3212  if (SrcInheritance == MSInheritanceModel::Virtual) {
3213  if (int64_t SrcOffsetToFirstVBase =
3214  getContext().getOffsetOfBaseWithVBPtr(SrcRD).getQuantity()) {
3215  llvm::Value *UndoSrcAdjustment = Builder.CreateSelect(
3216  SrcVBIndexEqZero,
3217  llvm::ConstantInt::get(CGM.IntTy, SrcOffsetToFirstVBase),
3218  getZeroInt());
3219  NVAdjustField = Builder.CreateNSWAdd(NVAdjustField, UndoSrcAdjustment);
3220  }
3221  }
3222 
3223  // A non-zero vbindex implies that we are dealing with a source member in a
3224  // floating virtual base in addition to some non-virtual offset. If the
3225  // vbindex is zero, we are dealing with a source that exists in a non-virtual,
3226  // fixed, base. The difference between these two cases is that the vbindex +
3227  // nvoffset *always* point to the member regardless of what context they are
3228  // evaluated in so long as the vbindex is adjusted. A member inside a fixed
3229  // base requires explicit nv adjustment.
3230  llvm::Constant *BaseClassOffset = llvm::ConstantInt::get(
3231  CGM.IntTy,
3232  CGM.computeNonVirtualBaseClassOffset(DerivedClass, PathBegin, PathEnd)
3233  .getQuantity());
3234 
3235  llvm::Value *NVDisp;
3236  if (IsDerivedToBase)
3237  NVDisp = Builder.CreateNSWSub(NVAdjustField, BaseClassOffset, "adj");
3238  else
3239  NVDisp = Builder.CreateNSWAdd(NVAdjustField, BaseClassOffset, "adj");
3240 
3241  NVAdjustField = Builder.CreateSelect(SrcVBIndexEqZero, NVDisp, getZeroInt());
3242 
3243  // Update the vbindex to an appropriate value in the destination because
3244  // SrcRD's vbtable might not be a strict prefix of the one in DstRD.
3245  llvm::Value *DstVBIndexEqZero = SrcVBIndexEqZero;
3246  if (inheritanceModelHasVBTableOffsetField(DstInheritance) &&
3247  inheritanceModelHasVBTableOffsetField(SrcInheritance)) {
3248  if (llvm::GlobalVariable *VDispMap =
3249  getAddrOfVirtualDisplacementMap(SrcRD, DstRD)) {
3250  llvm::Value *VBIndex = Builder.CreateExactUDiv(
3251  VirtualBaseAdjustmentOffset, llvm::ConstantInt::get(CGM.IntTy, 4));
3252  if (IsConstant) {
3253  llvm::Constant *Mapping = VDispMap->getInitializer();
3254  VirtualBaseAdjustmentOffset =
3255  Mapping->getAggregateElement(cast<llvm::Constant>(VBIndex));
3256  } else {
3257  llvm::Value *Idxs[] = {getZeroInt(), VBIndex};
3258  VirtualBaseAdjustmentOffset =
3259  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(VDispMap, Idxs),
3261  }
3262 
3263  DstVBIndexEqZero =
3264  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3265  }
3266  }
3267 
3268  // Set the VBPtrOffset to zero if the vbindex is zero. Otherwise, initialize
3269  // it to the offset of the vbptr.
3270  if (inheritanceModelHasVBPtrOffsetField(DstInheritance)) {
3271  llvm::Value *DstVBPtrOffset = llvm::ConstantInt::get(
3272  CGM.IntTy,
3273  getContext().getASTRecordLayout(DstRD).getVBPtrOffset().getQuantity());
3274  VBPtrOffset =
3275  Builder.CreateSelect(DstVBIndexEqZero, getZeroInt(), DstVBPtrOffset);
3276  }
3277 
3278  // Likewise, apply a similar adjustment so that dereferencing the member
3279  // pointer correctly accounts for the distance between the start of the first
3280  // virtual base and the top of the MDC.
3281  if (DstInheritance == MSInheritanceModel::Virtual) {
3282  if (int64_t DstOffsetToFirstVBase =
3283  getContext().getOffsetOfBaseWithVBPtr(DstRD).getQuantity()) {
3284  llvm::Value *DoDstAdjustment = Builder.CreateSelect(
3285  DstVBIndexEqZero,
3286  llvm::ConstantInt::get(CGM.IntTy, DstOffsetToFirstVBase),
3287  getZeroInt());
3288  NVAdjustField = Builder.CreateNSWSub(NVAdjustField, DoDstAdjustment);
3289  }
3290  }
3291 
3292  // Recompose dst from the null struct and the adjusted fields from src.
3293  llvm::Value *Dst;
3294  if (inheritanceModelHasOnlyOneField(IsFunc, DstInheritance)) {
3295  Dst = FirstField;
3296  } else {
3297  Dst = llvm::UndefValue::get(ConvertMemberPointerType(DstTy));
3298  unsigned Idx = 0;
3299  Dst = Builder.CreateInsertValue(Dst, FirstField, Idx++);
3300  if (inheritanceModelHasNVOffsetField(IsFunc, DstInheritance))
3301  Dst = Builder.CreateInsertValue(Dst, NonVirtualBaseAdjustment, Idx++);
3302  if (inheritanceModelHasVBPtrOffsetField(DstInheritance))
3303  Dst = Builder.CreateInsertValue(Dst, VBPtrOffset, Idx++);
3304  if (inheritanceModelHasVBTableOffsetField(DstInheritance))
3305  Dst = Builder.CreateInsertValue(Dst, VirtualBaseAdjustmentOffset, Idx++);
3306  }
3307  return Dst;
3308 }
3309 
3310 llvm::Constant *
3311 MicrosoftCXXABI::EmitMemberPointerConversion(const CastExpr *E,
3312  llvm::Constant *Src) {
3313  const MemberPointerType *SrcTy =
3315  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3316 
3317  CastKind CK = E->getCastKind();
3318 
3319  return EmitMemberPointerConversion(SrcTy, DstTy, CK, E->path_begin(),
3320  E->path_end(), Src);
3321 }
3322 
3323 llvm::Constant *MicrosoftCXXABI::EmitMemberPointerConversion(
3324  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3326  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src) {
3327  assert(CK == CK_DerivedToBaseMemberPointer ||
3328  CK == CK_BaseToDerivedMemberPointer ||
3329  CK == CK_ReinterpretMemberPointer);
3330  // If src is null, emit a new null for dst. We can't return src because dst
3331  // might have a new representation.
3332  if (MemberPointerConstantIsNull(SrcTy, Src))
3333  return EmitNullMemberPointer(DstTy);
3334 
3335  // We don't need to do anything for reinterpret_casts of non-null member
3336  // pointers. We should only get here when the two type representations have
3337  // the same size.
3338  if (CK == CK_ReinterpretMemberPointer)
3339  return Src;
3340 
3341  CGBuilderTy Builder(CGM, CGM.getLLVMContext());
3342  auto *Dst = cast<llvm::Constant>(EmitNonNullMemberPointerConversion(
3343  SrcTy, DstTy, CK, PathBegin, PathEnd, Src, Builder));
3344 
3345  return Dst;
3346 }
3347 
3348 CGCallee MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(
3349  CodeGenFunction &CGF, const Expr *E, Address This,
3350  llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
3351  const MemberPointerType *MPT) {
3352  assert(MPT->isMemberFunctionPointer());
3353  const FunctionProtoType *FPT =
3355  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
3356  llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
3357  CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));
3358  CGBuilderTy &Builder = CGF.Builder;
3359 
3360  MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
3361 
3362  // Extract the fields we need, regardless of model. We'll apply them if we
3363  // have them.
3364  llvm::Value *FunctionPointer = MemPtr;
3365  llvm::Value *NonVirtualBaseAdjustment = nullptr;
3366  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
3367  llvm::Value *VBPtrOffset = nullptr;
3368  if (MemPtr->getType()->isStructTy()) {
3369  // We need to extract values.
3370  unsigned I = 0;
3371  FunctionPointer = Builder.CreateExtractValue(MemPtr, I++);
3372  if (inheritanceModelHasNVOffsetField(MPT, Inheritance))
3373  NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++);
3374  if (inheritanceModelHasVBPtrOffsetField(Inheritance))
3375  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
3376  if (inheritanceModelHasVBTableOffsetField(Inheritance))
3377  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
3378  }
3379 
3380  if (VirtualBaseAdjustmentOffset) {
3381  ThisPtrForCall = AdjustVirtualBase(CGF, E, RD, This,
3382  VirtualBaseAdjustmentOffset, VBPtrOffset);
3383  } else {
3384  ThisPtrForCall = This.getPointer();
3385  }
3386 
3387  if (NonVirtualBaseAdjustment) {
3388  // Apply the adjustment and cast back to the original struct type.
3389  llvm::Value *Ptr = Builder.CreateBitCast(ThisPtrForCall, CGF.Int8PtrTy);
3390  Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment);
3391  ThisPtrForCall = Builder.CreateBitCast(Ptr, ThisPtrForCall->getType(),
3392  "this.adjusted");
3393  }
3394 
3395  FunctionPointer =
3396  Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo());
3397  CGCallee Callee(FPT, FunctionPointer);
3398  return Callee;
3399 }
3400 
3402  return new MicrosoftCXXABI(CGM);
3403 }
3404 
3405 // MS RTTI Overview:
3406 // The run time type information emitted by cl.exe contains 5 distinct types of
3407 // structures. Many of them reference each other.
3408 //
3409 // TypeInfo: Static classes that are returned by typeid.
3410 //
3411 // CompleteObjectLocator: Referenced by vftables. They contain information
3412 // required for dynamic casting, including OffsetFromTop. They also contain
3413 // a reference to the TypeInfo for the type and a reference to the
3414 // CompleteHierarchyDescriptor for the type.
3415 //
3416 // ClassHierarchyDescriptor: Contains information about a class hierarchy.
3417 // Used during dynamic_cast to walk a class hierarchy. References a base
3418 // class array and the size of said array.
3419 //
3420 // BaseClassArray: Contains a list of classes in a hierarchy. BaseClassArray is
3421 // somewhat of a misnomer because the most derived class is also in the list
3422 // as well as multiple copies of virtual bases (if they occur multiple times
3423 // in the hierarchy.) The BaseClassArray contains one BaseClassDescriptor for
3424 // every path in the hierarchy, in pre-order depth first order. Note, we do
3425 // not declare a specific llvm type for BaseClassArray, it's merely an array
3426 // of BaseClassDescriptor pointers.
3427 //
3428 // BaseClassDescriptor: Contains information about a class in a class hierarchy.
3429 // BaseClassDescriptor is also somewhat of a misnomer for the same reason that
3430 // BaseClassArray is. It contains information about a class within a
3431 // hierarchy such as: is this base is ambiguous and what is its offset in the
3432 // vbtable. The names of the BaseClassDescriptors have all of their fields
3433 // mangled into them so they can be aggressively deduplicated by the linker.
3434 
3435 static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
3436  StringRef MangledName("??_7type_info@@6B@");
3437  if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
3438  return VTable;
3439  return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
3440  /*isConstant=*/true,
3442  /*Initializer=*/nullptr, MangledName);
3443 }
3444 
3445 namespace {
3446 
3447 /// A Helper struct that stores information about a class in a class
3448 /// hierarchy. The information stored in these structs struct is used during
3449 /// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
3450 // During RTTI creation, MSRTTIClasses are stored in a contiguous array with
3451 // implicit depth first pre-order tree connectivity. getFirstChild and
3452 // getNextSibling allow us to walk the tree efficiently.
3453 struct MSRTTIClass {
3454  enum {
3455  IsPrivateOnPath = 1 | 8,
3456  IsAmbiguous = 2,
3457  IsPrivate = 4,
3458  IsVirtual = 16,
3459  HasHierarchyDescriptor = 64
3460  };
3461  MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
3462  uint32_t initialize(const MSRTTIClass *Parent,
3463  const CXXBaseSpecifier *Specifier);
3464 
3465  MSRTTIClass *getFirstChild() { return this + 1; }
3466  static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
3467  return Child + 1 + Child->NumBases;
3468  }
3469 
3470  const CXXRecordDecl *RD, *VirtualRoot;
3471  uint32_t Flags, NumBases, OffsetInVBase;
3472 };
3473 
3474 /// Recursively initialize the base class array.
3475 uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
3476  const CXXBaseSpecifier *Specifier) {
3477  Flags = HasHierarchyDescriptor;
3478  if (!Parent) {
3479  VirtualRoot = nullptr;
3480  OffsetInVBase = 0;
3481  } else {
3482  if (Specifier->getAccessSpecifier() != AS_public)
3483  Flags |= IsPrivate | IsPrivateOnPath;
3484  if (Specifier->isVirtual()) {
3485  Flags |= IsVirtual;
3486  VirtualRoot = RD;
3487  OffsetInVBase = 0;
3488  } else {
3489  if (Parent->Flags & IsPrivateOnPath)
3490  Flags |= IsPrivateOnPath;
3491  VirtualRoot = Parent->VirtualRoot;
3492  OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
3494  }
3495  }
3496  NumBases = 0;
3497  MSRTTIClass *Child = getFirstChild();
3498  for (const CXXBaseSpecifier &Base : RD->bases()) {
3499  NumBases += Child->initialize(this, &Base) + 1;
3500  Child = getNextChild(Child);
3501  }
3502  return NumBases;
3503 }
3504 
3505 static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
3506  switch (Ty->getLinkage()) {
3507  case NoLinkage:
3508  case InternalLinkage:
3509  case UniqueExternalLinkage:
3511 
3512  case VisibleNoLinkage:
3513  case ModuleInternalLinkage:
3514  case ModuleLinkage:
3515  case ExternalLinkage:
3516  return llvm::GlobalValue::LinkOnceODRLinkage;
3517  }
3518  llvm_unreachable("Invalid linkage!");
3519 }
3520 
3521 /// An ephemeral helper class for building MS RTTI types. It caches some
3522 /// calls to the module and information about the most derived class in a
3523 /// hierarchy.
3524 struct MSRTTIBuilder {
3525  enum {
3526  HasBranchingHierarchy = 1,
3527  HasVirtualBranchingHierarchy = 2,
3528  HasAmbiguousBases = 4
3529  };
3530 
3531  MSRTTIBuilder(MicrosoftCXXABI &ABI, const CXXRecordDecl *RD)
3532  : CGM(ABI.CGM), Context(CGM.getContext()),
3533  VMContext(CGM.getLLVMContext()), Module(CGM.getModule()), RD(RD),
3534  Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
3535  ABI(ABI) {}
3536 
3537  llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
3538  llvm::GlobalVariable *
3539  getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
3540  llvm::GlobalVariable *getClassHierarchyDescriptor();
3541  llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo &Info);
3542 
3543  CodeGenModule &CGM;
3544  ASTContext &Context;
3545  llvm::LLVMContext &VMContext;
3546  llvm::Module &Module;
3547  const CXXRecordDecl *RD;
3548  llvm::GlobalVariable::LinkageTypes Linkage;
3549  MicrosoftCXXABI &ABI;
3550 };
3551 
3552 } // namespace
3553 
3554 /// Recursively serializes a class hierarchy in pre-order depth first
3555 /// order.
3557  const CXXRecordDecl *RD) {
3558  Classes.push_back(MSRTTIClass(RD));
3559  for (const CXXBaseSpecifier &Base : RD->bases())
3560  serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
3561 }
3562 
3563 /// Find ambiguity among base classes.
3564 static void
3566  llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
3567  llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
3568  llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
3569  for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
3570  if ((Class->Flags & MSRTTIClass::IsVirtual) &&
3571  !VirtualBases.insert(Class->RD).second) {
3572  Class = MSRTTIClass::getNextChild(Class);
3573  continue;
3574  }
3575  if (!UniqueBases.insert(Class->RD).second)
3576  AmbiguousBases.insert(Class->RD);
3577  Class++;
3578  }
3579  if (AmbiguousBases.empty())
3580  return;
3581  for (MSRTTIClass &Class : Classes)
3582  if (AmbiguousBases.count(Class.RD))
3583  Class.Flags |= MSRTTIClass::IsAmbiguous;
3584 }
3585 
3586 llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
3587  SmallString<256> MangledName;
3588  {
3589  llvm::raw_svector_ostream Out(MangledName);
3590  ABI.getMangleContext().mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
3591  }
3592 
3593  // Check to see if we've already declared this ClassHierarchyDescriptor.
3594  if (auto CHD = Module.getNamedGlobal(MangledName))
3595  return CHD;
3596 
3597  // Serialize the class hierarchy and initialize the CHD Fields.
3599  serializeClassHierarchy(Classes, RD);
3600  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
3601  detectAmbiguousBases(Classes);
3602  int Flags = 0;
3603  for (auto Class : Classes) {
3604  if (Class.RD->getNumBases() > 1)
3605  Flags |= HasBranchingHierarchy;
3606  // Note: cl.exe does not calculate "HasAmbiguousBases" correctly. We
3607  // believe the field isn't actually used.
3608  if (Class.Flags & MSRTTIClass::IsAmbiguous)
3609  Flags |= HasAmbiguousBases;
3610  }
3611  if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
3612  Flags |= HasVirtualBranchingHierarchy;
3613  // These gep indices are used to get the address of the first element of the
3614  // base class array.
3615  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
3616  llvm::ConstantInt::get(CGM.IntTy, 0)};
3617 
3618  // Forward-declare the class hierarchy descriptor
3619  auto Type = ABI.getClassHierarchyDescriptorType();
3620  auto CHD = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3621  /*Initializer=*/nullptr,
3622  MangledName);
3623  if (CHD->isWeakForLinker())
3624  CHD->setComdat(CGM.getModule().getOrInsertComdat(CHD->getName()));
3625 
3626  auto *Bases = getBaseClassArray(Classes);
3627 
3628  // Initialize the base class ClassHierarchyDescriptor.
3629  llvm::Constant *Fields[] = {
3630  llvm::ConstantInt::get(CGM.IntTy, 0), // reserved by the runtime
3631  llvm::ConstantInt::get(CGM.IntTy, Flags),
3632  llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
3633  ABI.getImageRelativeConstant(llvm::ConstantExpr::getInBoundsGetElementPtr(
3634  Bases->getValueType(), Bases,
3635  llvm::ArrayRef<llvm::Value *>(GEPIndices))),
3636  };
3637  CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3638  return CHD;
3639 }
3640 
3641 llvm::GlobalVariable *
3642 MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
3643  SmallString<256> MangledName;
3644  {
3645  llvm::raw_svector_ostream Out(MangledName);
3646  ABI.getMangleContext().mangleCXXRTTIBaseClassArray(RD, Out);
3647  }
3648 
3649  // Forward-declare the base class array.
3650  // cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
3651  // mode) bytes of padding. We provide a pointer sized amount of padding by
3652  // adding +1 to Classes.size(). The sections have pointer alignment and are
3653  // marked pick-any so it shouldn't matter.
3654  llvm::Type *PtrType = ABI.getImageRelativeType(
3655  ABI.getBaseClassDescriptorType()->getPointerTo());
3656  auto *ArrType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
3657  auto *BCA =
3658  new llvm::GlobalVariable(Module, ArrType,
3659  /*isConstant=*/true, Linkage,
3660  /*Initializer=*/nullptr, MangledName);
3661  if (BCA->isWeakForLinker())
3662  BCA->setComdat(CGM.getModule().getOrInsertComdat(BCA->getName()));
3663 
3664  // Initialize the BaseClassArray.
3665  SmallVector<llvm::Constant *, 8> BaseClassArrayData;
3666  for (MSRTTIClass &Class : Classes)
3667  BaseClassArrayData.push_back(
3668  ABI.getImageRelativeConstant(getBaseClassDescriptor(Class)));
3669  BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
3670  BCA->setInitializer(llvm::ConstantArray::get(ArrType, BaseClassArrayData));
3671  return BCA;
3672 }
3673 
3674 llvm::GlobalVariable *
3675 MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
3676  // Compute the fields for the BaseClassDescriptor. They are computed up front
3677  // because they are mangled into the name of the object.
3678  uint32_t OffsetInVBTable = 0;
3679  int32_t VBPtrOffset = -1;
3680  if (Class.VirtualRoot) {
3681  auto &VTableContext = CGM.getMicrosoftVTableContext();
3682  OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
3683  VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
3684  }
3685 
3686  SmallString<256> MangledName;
3687  {
3688  llvm::raw_svector_ostream Out(MangledName);
3689  ABI.getMangleContext().mangleCXXRTTIBaseClassDescriptor(
3690  Class.RD, Class.OffsetInVBase, VBPtrOffset, OffsetInVBTable,
3691  Class.Flags, Out);
3692  }
3693 
3694  // Check to see if we've already declared this object.
3695  if (auto BCD = Module.getNamedGlobal(MangledName))
3696  return BCD;
3697 
3698  // Forward-declare the base class descriptor.
3699  auto Type = ABI.getBaseClassDescriptorType();
3700  auto BCD =
3701  new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3702  /*Initializer=*/nullptr, MangledName);
3703  if (BCD->isWeakForLinker())
3704  BCD->setComdat(CGM.getModule().getOrInsertComdat(BCD->getName()));
3705 
3706  // Initialize the BaseClassDescriptor.
3707  llvm::Constant *Fields[] = {
3708  ABI.getImageRelativeConstant(
3709  ABI.getAddrOfRTTIDescriptor(Context.getTypeDeclType(Class.RD))),
3710  llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
3711  llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
3712  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
3713  llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
3714  llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
3715  ABI.getImageRelativeConstant(
3716  MSRTTIBuilder(ABI, Class.RD).getClassHierarchyDescriptor()),
3717  };
3718  BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3719  return BCD;
3720 }
3721 
3722 llvm::GlobalVariable *
3723 MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo &Info) {
3724  SmallString<256> MangledName;
3725  {
3726  llvm::raw_svector_ostream Out(MangledName);
3727  ABI.getMangleContext().mangleCXXRTTICompleteObjectLocator(RD, Info.MangledPath, Out);
3728  }
3729 
3730  // Check to see if we've already computed this complete object locator.
3731  if (auto COL = Module.getNamedGlobal(MangledName))
3732  return COL;
3733 
3734  // Compute the fields of the complete object locator.
3735  int OffsetToTop = Info.FullOffsetInMDC.getQuantity();
3736  int VFPtrOffset = 0;
3737  // The offset includes the vtordisp if one exists.
3738  if (const CXXRecordDecl *VBase = Info.getVBaseWithVPtr())
3739  if (Context.getASTRecordLayout(RD)
3741  .find(VBase)
3742  ->second.hasVtorDisp())
3743  VFPtrOffset = Info.NonVirtualOffset.getQuantity() + 4;
3744 
3745  // Forward-declare the complete object locator.
3746  llvm::StructType *Type = ABI.getCompleteObjectLocatorType();
3747  auto COL = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3748  /*Initializer=*/nullptr, MangledName);
3749 
3750  // Initialize the CompleteObjectLocator.
3751  llvm::Constant *Fields[] = {
3752  llvm::ConstantInt::get(CGM.IntTy, ABI.isImageRelative()),
3753  llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
3754  llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
3755  ABI.getImageRelativeConstant(
3756  CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(RD))),
3757  ABI.getImageRelativeConstant(getClassHierarchyDescriptor()),
3758  ABI.getImageRelativeConstant(COL),
3759  };
3760  llvm::ArrayRef<llvm::Constant *> FieldsRef(Fields);
3761  if (!ABI.isImageRelative())
3762  FieldsRef = FieldsRef.drop_back();
3763  COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
3764  if (COL->isWeakForLinker())
3765  COL->setComdat(CGM.getModule().getOrInsertComdat(COL->getName()));
3766  return COL;
3767 }
3768 
3770  bool &IsConst, bool &IsVolatile,
3771  bool &IsUnaligned) {
3772  T = Context.getExceptionObjectType(T);
3773 
3774  // C++14 [except.handle]p3:
3775  // A handler is a match for an exception object of type E if [...]
3776  // - the handler is of type cv T or const T& where T is a pointer type and
3777  // E is a pointer type that can be converted to T by [...]
3778  // - a qualification conversion
3779  IsConst = false;
3780  IsVolatile = false;
3781  IsUnaligned = false;
3782  QualType PointeeType = T->getPointeeType();
3783  if (!PointeeType.isNull()) {
3784  IsConst = PointeeType.isConstQualified();
3785  IsVolatile = PointeeType.isVolatileQualified();
3786  IsUnaligned = PointeeType.getQualifiers().hasUnaligned();
3787  }
3788 
3789  // Member pointer types like "const int A::*" are represented by having RTTI
3790  // for "int A::*" and separately storing the const qualifier.
3791  if (const auto *MPTy = T->getAs<MemberPointerType>())
3792  T = Context.getMemberPointerType(PointeeType.getUnqualifiedType(),
3793  MPTy->getClass());
3794 
3795  // Pointer types like "const int * const *" are represented by having RTTI
3796  // for "const int **" and separately storing the const qualifier.
3797  if (T->isPointerType())
3798  T = Context.getPointerType(PointeeType.getUnqualifiedType());
3799 
3800  return T;
3801 }
3802 
3804 MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
3805  QualType CatchHandlerType) {
3806  // TypeDescriptors for exceptions never have qualified pointer types,
3807  // qualifiers are stored separately in order to support qualification
3808  // conversions.
3809  bool IsConst, IsVolatile, IsUnaligned;
3810  Type =
3811  decomposeTypeForEH(getContext(), Type, IsConst, IsVolatile, IsUnaligned);
3812 
3813  bool IsReference = CatchHandlerType->isReferenceType();
3814 
3815  uint32_t Flags = 0;
3816  if (IsConst)
3817  Flags |= 1;
3818  if (IsVolatile)
3819  Flags |= 2;
3820  if (IsUnaligned)
3821  Flags |= 4;
3822  if (IsReference)
3823  Flags |= 8;
3824 
3825  return CatchTypeInfo{getAddrOfRTTIDescriptor(Type)->stripPointerCasts(),
3826  Flags};
3827 }
3828 
3829 /// Gets a TypeDescriptor. Returns a llvm::Constant * rather than a
3830 /// llvm::GlobalVariable * because different type descriptors have different
3831 /// types, and need to be abstracted. They are abstracting by casting the
3832 /// address to an Int8PtrTy.
3833 llvm::Constant *MicrosoftCXXABI::getAddrOfRTTIDescriptor(QualType Type) {
3834  SmallString<256> MangledName;
3835  {
3836  llvm::raw_svector_ostream Out(MangledName);
3837  getMangleContext().mangleCXXRTTI(Type, Out);
3838  }
3839 
3840  // Check to see if we've already declared this TypeDescriptor.
3841  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
3842  return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
3843 
3844  // Note for the future: If we would ever like to do deferred emission of
3845  // RTTI, check if emitting vtables opportunistically need any adjustment.
3846 
3847  // Compute the fields for the TypeDescriptor.
3848  SmallString<256> TypeInfoString;
3849  {
3850  llvm::raw_svector_ostream Out(TypeInfoString);
3851  getMangleContext().mangleCXXRTTIName(Type, Out);
3852  }
3853 
3854  // Declare and initialize the TypeDescriptor.
3855  llvm::Constant *Fields[] = {
3856  getTypeInfoVTable(CGM), // VFPtr
3857  llvm::ConstantPointerNull::get(CGM.Int8PtrTy), // Runtime data
3858  llvm::ConstantDataArray::getString(CGM.getLLVMContext(), TypeInfoString)};
3859  llvm::StructType *TypeDescriptorType =
3860  getTypeDescriptorType(TypeInfoString);
3861  auto *Var = new llvm::GlobalVariable(
3862  CGM.getModule(), TypeDescriptorType, /*isConstant=*/false,
3863  getLinkageForRTTI(Type),
3864  llvm::ConstantStruct::get(TypeDescriptorType, Fields),
3865  MangledName);
3866  if (Var->isWeakForLinker())
3867  Var->setComdat(CGM.getModule().getOrInsertComdat(Var->getName()));
3868  return llvm::ConstantExpr::getBitCast(Var, CGM.Int8PtrTy);
3869 }
3870 
3871 /// Gets or a creates a Microsoft CompleteObjectLocator.
3872 llvm::GlobalVariable *
3873 MicrosoftCXXABI::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
3874  const VPtrInfo &Info) {
3875  return MSRTTIBuilder(*this, RD).getCompleteObjectLocator(Info);
3876 }
3877 
3878 void MicrosoftCXXABI::emitCXXStructor(GlobalDecl GD) {
3879  if (auto *ctor = dyn_cast<CXXConstructorDecl>(GD.getDecl())) {
3880  // There are no constructor variants, always emit the complete destructor.
3881  llvm::Function *Fn =
3883  CGM.maybeSetTrivialComdat(*ctor, *Fn);
3884  return;
3885  }
3886 
3887  auto *dtor = cast<CXXDestructorDecl>(GD.getDecl());
3888 
3889  // Emit the base destructor if the base and complete (vbase) destructors are
3890  // equivalent. This effectively implements -mconstructor-aliases as part of
3891  // the ABI.
3892  if (GD.getDtorType() == Dtor_Complete &&
3893  dtor->getParent()->getNumVBases() == 0)
3894  GD = GD.getWithDtorType(Dtor_Base);
3895 
3896  // The base destructor is equivalent to the base destructor of its
3897  // base class if there is exactly one non-virtual base class with a
3898  // non-trivial destructor, there are no fields with a non-trivial
3899  // destructor, and the body of the destructor is trivial.
3900  if (GD.getDtorType() == Dtor_Base && !CGM.TryEmitBaseDestructorAsAlias(dtor))
3901  return;
3902 
3903  llvm::Function *Fn = CGM.codegenCXXStructor(GD);
3904  if (Fn->isWeakForLinker())
3905  Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName()));
3906 }
3907 
3908 llvm::Function *
3909 MicrosoftCXXABI::getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
3910  CXXCtorType CT) {
3911  assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure);
3912 
3913  // Calculate the mangled name.
3914  SmallString<256> ThunkName;
3915  llvm::raw_svector_ostream Out(ThunkName);
3916  getMangleContext().mangleCXXCtor(CD, CT, Out);
3917 
3918  // If the thunk has been generated previously, just return it.
3919  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
3920  return cast<llvm::Function>(GV);
3921 
3922  // Create the llvm::Function.
3923  const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeMSCtorClosure(CD, CT);
3924  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
3925  const CXXRecordDecl *RD = CD->getParent();
3926  QualType RecordTy = getContext().getRecordType(RD);
3927  llvm::Function *ThunkFn = llvm::Function::Create(
3928  ThunkTy, getLinkageForRTTI(RecordTy), ThunkName.str(), &CGM.getModule());
3929  ThunkFn->setCallingConv(static_cast<llvm::CallingConv::ID>(
3930  FnInfo.getEffectiveCallingConvention()));
3931  if (ThunkFn->isWeakForLinker())
3932  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
3933  bool IsCopy = CT == Ctor_CopyingClosure;
3934 
3935  // Start codegen.
3936  CodeGenFunction CGF(CGM);
3937  CGF.CurGD = GlobalDecl(CD, Ctor_Complete);
3938 
3939  // Build FunctionArgs.
3940  FunctionArgList FunctionArgs;
3941 
3942  // A constructor always starts with a 'this' pointer as its first argument.
3943  buildThisParam(CGF, FunctionArgs);
3944 
3945  // Following the 'this' pointer is a reference to the source object that we
3946  // are copying from.
3947  ImplicitParamDecl SrcParam(
3948  getContext(), /*DC=*/nullptr, SourceLocation(),
3949  &getContext().Idents.get("src"),
3950  getContext().getLValueReferenceType(RecordTy,
3951  /*SpelledAsLValue=*/true),
3953  if (IsCopy)
3954  FunctionArgs.push_back(&SrcParam);
3955 
3956  // Constructors for classes which utilize virtual bases have an additional
3957  // parameter which indicates whether or not it is being delegated to by a more
3958  // derived constructor.
3959  ImplicitParamDecl IsMostDerived(getContext(), /*DC=*/nullptr,
3960  SourceLocation(),
3961  &getContext().Idents.get("is_most_derived"),
3962  getContext().IntTy, ImplicitParamDecl::Other);
3963  // Only add the parameter to the list if the class has virtual bases.
3964  if (RD->getNumVBases() > 0)
3965  FunctionArgs.push_back(&IsMostDerived);
3966 
3967  // Start defining the function.
3968  auto NL = ApplyDebugLocation::CreateEmpty(CGF);
3969  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
3970  FunctionArgs, CD->getLocation(), SourceLocation());
3971  // Create a scope with an artificial location for the body of this function.
3972  auto AL = ApplyDebugLocation::CreateArtificial(CGF);
3973  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
3974  llvm::Value *This = getThisValue(CGF);
3975 
3976  llvm::Value *SrcVal =
3977  IsCopy ? CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(&SrcParam), "src")
3978  : nullptr;
3979 
3980  CallArgList Args;
3981 
3982  // Push the this ptr.
3983  Args.add(RValue::get(This), CD->getThisType());
3984 
3985  // Push the src ptr.
3986  if (SrcVal)
3987  Args.add(RValue::get(SrcVal), SrcParam.getType());
3988 
3989  // Add the rest of the default arguments.
3991  ArrayRef<ParmVarDecl *> params = CD->parameters().drop_front(IsCopy ? 1 : 0);
3992  for (const ParmVarDecl *PD : params) {
3993  assert(PD->hasDefaultArg() && "ctor closure lacks default args");
3994  ArgVec.push_back(PD->getDefaultArg());
3995  }
3996 
3997  CodeGenFunction::RunCleanupsScope Cleanups(CGF);
3998 
3999  const auto *FPT = CD->getType()->castAs<FunctionProtoType>();
4000  CGF.EmitCallArgs(Args, FPT, llvm::makeArrayRef(ArgVec), CD, IsCopy ? 1 : 0);
4001 
4002  // Insert any ABI-specific implicit constructor arguments.
4003  AddedStructorArgs ExtraArgs =
4004  addImplicitConstructorArgs(CGF, CD, Ctor_Complete,
4005  /*ForVirtualBase=*/false,
4006  /*Delegating=*/false, Args);
4007  // Call the destructor with our arguments.
4008  llvm::Constant *CalleePtr =
4010  CGCallee Callee =
4011  CGCallee::forDirect(CalleePtr, GlobalDecl(CD, Ctor_Complete));
4012  const CGFunctionInfo &CalleeInfo = CGM.getTypes().arrangeCXXConstructorCall(
4013  Args, CD, Ctor_Complete, ExtraArgs.Prefix, ExtraArgs.Suffix);
4014  CGF.EmitCall(CalleeInfo, Callee, ReturnValueSlot(), Args);
4015 
4016  Cleanups.ForceCleanup();
4017 
4018  // Emit the ret instruction, remove any temporary instructions created for the
4019  // aid of CodeGen.
4021 
4022  return ThunkFn;
4023 }
4024 
4025 llvm::Constant *MicrosoftCXXABI::getCatchableType(QualType T,
4026  uint32_t NVOffset,
4027  int32_t VBPtrOffset,
4028  uint32_t VBIndex) {
4029  assert(!T->isReferenceType());
4030 
4031  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
4032  const CXXConstructorDecl *CD =
4033  RD ? CGM.getContext().getCopyConstructorForExceptionObject(RD) : nullptr;
4035  if (CD)
4036  if (!hasDefaultCXXMethodCC(getContext(), CD) || CD->getNumParams() != 1)
4037  CT = Ctor_CopyingClosure;
4038 
4039  uint32_t Size = getContext().getTypeSizeInChars(T).getQuantity();
4040  SmallString<256> MangledName;
4041  {
4042  llvm::raw_svector_ostream Out(MangledName);
4043  getMangleContext().mangleCXXCatchableType(T, CD, CT, Size, NVOffset,
4044  VBPtrOffset, VBIndex, Out);
4045  }
4046  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
4047  return getImageRelativeConstant(GV);
4048 
4049  // The TypeDescriptor is used by the runtime to determine if a catch handler
4050  // is appropriate for the exception object.
4051  llvm::Constant *TD = getImageRelativeConstant(getAddrOfRTTIDescriptor(T));
4052 
4053  // The runtime is responsible for calling the copy constructor if the
4054  // exception is caught by value.
4055  llvm::Constant *CopyCtor;
4056  if (CD) {
4057  if (CT == Ctor_CopyingClosure)
4058  CopyCtor = getAddrOfCXXCtorClosure(CD, Ctor_CopyingClosure);
4059  else
4060  CopyCtor = CGM.getAddrOfCXXStructor(GlobalDecl(CD, Ctor_Complete));
4061 
4062  CopyCtor = llvm::ConstantExpr::getBitCast(CopyCtor, CGM.Int8PtrTy);
4063  } else {
4064  CopyCtor = llvm::Constant::getNullValue(CGM.Int8PtrTy);
4065  }
4066  CopyCtor = getImageRelativeConstant(CopyCtor);
4067 
4068  bool IsScalar = !RD;
4069  bool HasVirtualBases = false;
4070  bool IsStdBadAlloc = false; // std::bad_alloc is special for some reason.
4071  QualType PointeeType = T;
4072  if (T->isPointerType())
4073  PointeeType = T->getPointeeType();
4074  if (const CXXRecordDecl *RD = PointeeType->getAsCXXRecordDecl()) {
4075  HasVirtualBases = RD->getNumVBases() > 0;
4076  if (IdentifierInfo *II = RD->getIdentifier())
4077  IsStdBadAlloc = II->isStr("bad_alloc") && RD->isInStdNamespace();
4078  }
4079 
4080  // Encode the relevant CatchableType properties into the Flags bitfield.
4081  // FIXME: Figure out how bits 2 or 8 can get set.
4082  uint32_t Flags = 0;
4083  if (IsScalar)
4084  Flags |= 1;
4085  if (HasVirtualBases)
4086  Flags |= 4;
4087  if (IsStdBadAlloc)
4088  Flags |= 16;
4089 
4090  llvm::Constant *Fields[] = {
4091  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4092  TD, // TypeDescriptor
4093  llvm::ConstantInt::get(CGM.IntTy, NVOffset), // NonVirtualAdjustment
4094  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset), // OffsetToVBPtr
4095  llvm::ConstantInt::get(CGM.IntTy, VBIndex), // VBTableIndex
4096  llvm::ConstantInt::get(CGM.IntTy, Size), // Size
4097  CopyCtor // CopyCtor
4098  };
4099  llvm::StructType *CTType = getCatchableTypeType();
4100  auto *GV = new llvm::GlobalVariable(
4101  CGM.getModule(), CTType, /*isConstant=*/true, getLinkageForRTTI(T),
4102  llvm::ConstantStruct::get(CTType, Fields), MangledName);
4103  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4104  GV->setSection(".xdata");
4105  if (GV->isWeakForLinker())
4106  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4107  return getImageRelativeConstant(GV);
4108 }
4109 
4110 llvm::GlobalVariable *MicrosoftCXXABI::getCatchableTypeArray(QualType T) {
4111  assert(!T->isReferenceType());
4112 
4113  // See if we've already generated a CatchableTypeArray for this type before.
4114  llvm::GlobalVariable *&CTA = CatchableTypeArrays[T];
4115  if (CTA)
4116  return CTA;
4117 
4118  // Ensure that we don't have duplicate entries in our CatchableTypeArray by
4119  // using a SmallSetVector. Duplicates may arise due to virtual bases
4120  // occurring more than once in the hierarchy.
4122 
4123  // C++14 [except.handle]p3:
4124  // A handler is a match for an exception object of type E if [...]
4125  // - the handler is of type cv T or cv T& and T is an unambiguous public
4126  // base class of E, or
4127  // - the handler is of type cv T or const T& where T is a pointer type and
4128  // E is a pointer type that can be converted to T by [...]
4129  // - a standard pointer conversion (4.10) not involving conversions to
4130  // pointers to private or protected or ambiguous classes
4131  const CXXRecordDecl *MostDerivedClass = nullptr;
4132  bool IsPointer = T->isPointerType();
4133  if (IsPointer)
4134  MostDerivedClass = T->getPointeeType()->getAsCXXRecordDecl();
4135  else
4136  MostDerivedClass = T->getAsCXXRecordDecl();
4137 
4138  // Collect all the unambiguous public bases of the MostDerivedClass.
4139  if (MostDerivedClass) {
4140  const ASTContext &Context = getContext();
4141  const ASTRecordLayout &MostDerivedLayout =
4142  Context.getASTRecordLayout(MostDerivedClass);
4143  MicrosoftVTableContext &VTableContext = CGM.getMicrosoftVTableContext();
4145  serializeClassHierarchy(Classes, MostDerivedClass);
4146  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
4147  detectAmbiguousBases(Classes);
4148  for (const MSRTTIClass &Class : Classes) {
4149  // Skip any ambiguous or private bases.
4150  if (Class.Flags &
4151  (MSRTTIClass::IsPrivateOnPath | MSRTTIClass::IsAmbiguous))
4152  continue;
4153  // Write down how to convert from a derived pointer to a base pointer.
4154  uint32_t OffsetInVBTable = 0;
4155  int32_t VBPtrOffset = -1;
4156  if (Class.VirtualRoot) {
4157  OffsetInVBTable =
4158  VTableContext.getVBTableIndex(MostDerivedClass, Class.VirtualRoot)*4;
4159  VBPtrOffset = MostDerivedLayout.getVBPtrOffset().getQuantity();
4160  }
4161 
4162  // Turn our record back into a pointer if the exception object is a
4163  // pointer.
4164  QualType RTTITy = QualType(Class.RD->getTypeForDecl(), 0);
4165  if (IsPointer)
4166  RTTITy = Context.getPointerType(RTTITy);
4167  CatchableTypes.insert(getCatchableType(RTTITy, Class.OffsetInVBase,
4168  VBPtrOffset, OffsetInVBTable));
4169  }
4170  }
4171 
4172  // C++14 [except.handle]p3:
4173  // A handler is a match for an exception object of type E if
4174  // - The handler is of type cv T or cv T& and E and T are the same type
4175  // (ignoring the top-level cv-qualifiers)
4176  CatchableTypes.insert(getCatchableType(T));
4177 
4178  // C++14 [except.handle]p3:
4179  // A handler is a match for an exception object of type E if
4180  // - the handler is of type cv T or const T& where T is a pointer type and
4181  // E is a pointer type that can be converted to T by [...]
4182  // - a standard pointer conversion (4.10) not involving conversions to
4183  // pointers to private or protected or ambiguous classes
4184  //
4185  // C++14 [conv.ptr]p2:
4186  // A prvalue of type "pointer to cv T," where T is an object type, can be
4187  // converted to a prvalue of type "pointer to cv void".
4188  if (IsPointer && T->getPointeeType()->isObjectType())
4189  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4190 
4191  // C++14 [except.handle]p3:
4192  // A handler is a match for an exception object of type E if [...]
4193  // - the handler is of type cv T or const T& where T is a pointer or
4194  // pointer to member type and E is std::nullptr_t.
4195  //
4196  // We cannot possibly list all possible pointer types here, making this
4197  // implementation incompatible with the standard. However, MSVC includes an
4198  // entry for pointer-to-void in this case. Let's do the same.
4199  if (T->isNullPtrType())
4200  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4201 
4202  uint32_t NumEntries = CatchableTypes.size();
4203  llvm::Type *CTType =
4204  getImageRelativeType(getCatchableTypeType()->getPointerTo());
4205  llvm::ArrayType *AT = llvm::ArrayType::get(CTType, NumEntries);
4206  llvm::StructType *CTAType = getCatchableTypeArrayType(NumEntries);
4207  llvm::Constant *Fields[] = {
4208  llvm::ConstantInt::get(CGM.IntTy, NumEntries), // NumEntries
4209  llvm::ConstantArray::get(
4210  AT, llvm::makeArrayRef(CatchableTypes.begin(),
4211  CatchableTypes.end())) // CatchableTypes
4212  };
4213  SmallString<256> MangledName;
4214  {
4215  llvm::raw_svector_ostream Out(MangledName);
4216  getMangleContext().mangleCXXCatchableTypeArray(T, NumEntries, Out);
4217  }
4218  CTA = new llvm::GlobalVariable(
4219  CGM.getModule(), CTAType, /*isConstant=*/true, getLinkageForRTTI(T),
4220  llvm::ConstantStruct::get(CTAType, Fields), MangledName);
4221  CTA->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4222  CTA->setSection(".xdata");
4223  if (CTA->isWeakForLinker())
4224  CTA->setComdat(CGM.getModule().getOrInsertComdat(CTA->getName()));
4225  return CTA;
4226 }
4227 
4228 llvm::GlobalVariable *MicrosoftCXXABI::getThrowInfo(QualType T) {
4229  bool IsConst, IsVolatile, IsUnaligned;
4230  T = decomposeTypeForEH(getContext(), T, IsConst, IsVolatile, IsUnaligned);
4231 
4232  // The CatchableTypeArray enumerates the various (CV-unqualified) types that
4233  // the exception object may be caught as.
4234  llvm::GlobalVariable *CTA = getCatchableTypeArray(T);
4235  // The first field in a CatchableTypeArray is the number of CatchableTypes.
4236  // This is used as a component of the mangled name which means that we need to
4237  // know what it is in order to see if we have previously generated the
4238  // ThrowInfo.
4239  uint32_t NumEntries =
4240  cast<llvm::ConstantInt>(CTA->getInitializer()->getAggregateElement(0U))
4241  ->getLimitedValue();
4242 
4243  SmallString<256> MangledName;
4244  {
4245  llvm::raw_svector_ostream Out(MangledName);
4246  getMangleContext().mangleCXXThrowInfo(T, IsConst, IsVolatile, IsUnaligned,
4247  NumEntries, Out);
4248  }
4249 
4250  // Reuse a previously generated ThrowInfo if we have generated an appropriate
4251  // one before.
4252  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
4253  return GV;
4254 
4255  // The RTTI TypeDescriptor uses an unqualified type but catch clauses must
4256  // be at least as CV qualified. Encode this requirement into the Flags
4257  // bitfield.
4258  uint32_t Flags = 0;
4259  if (IsConst)
4260  Flags |= 1;
4261  if (IsVolatile)
4262  Flags |= 2;
4263  if (IsUnaligned)
4264  Flags |= 4;
4265 
4266  // The cleanup-function (a destructor) must be called when the exception
4267  // object's lifetime ends.
4268  llvm::Constant *CleanupFn = llvm::Constant::getNullValue(CGM.Int8PtrTy);
4269  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4270  if (CXXDestructorDecl *DtorD = RD->getDestructor())
4271  if (!DtorD->isTrivial())
4272  CleanupFn = llvm::ConstantExpr::getBitCast(
4274  CGM.Int8PtrTy);
4275  // This is unused as far as we can tell, initialize it to null.
4276  llvm::Constant *ForwardCompat =
4277  getImageRelativeConstant(llvm::Constant::getNullValue(CGM.Int8PtrTy));
4278  llvm::Constant *PointerToCatchableTypes = getImageRelativeConstant(
4279  llvm::ConstantExpr::getBitCast(CTA, CGM.Int8PtrTy));
4280  llvm::StructType *TIType = getThrowInfoType();
4281  llvm::Constant *Fields[] = {
4282  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4283  getImageRelativeConstant(CleanupFn), // CleanupFn
4284  ForwardCompat, // ForwardCompat
4285  PointerToCatchableTypes // CatchableTypeArray
4286  };
4287  auto *GV = new llvm::GlobalVariable(
4288  CGM.getModule(), TIType, /*isConstant=*/true, getLinkageForRTTI(T),
4289  llvm::ConstantStruct::get(TIType, Fields), StringRef(MangledName));
4290  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4291  GV->setSection(".xdata");
4292  if (GV->isWeakForLinker())
4293  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4294  return GV;
4295 }
4296 
4297 void MicrosoftCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
4298  const Expr *SubExpr = E->getSubExpr();
4299  QualType ThrowType = SubExpr->getType();
4300  // The exception object lives on the stack and it's address is passed to the
4301  // runtime function.
4302  Address AI = CGF.CreateMemTemp(ThrowType);
4303  CGF.EmitAnyExprToMem(SubExpr, AI, ThrowType.getQualifiers(),
4304  /*IsInit=*/true);
4305 
4306  // The so-called ThrowInfo is used to describe how the exception object may be
4307  // caught.
4308  llvm::GlobalVariable *TI = getThrowInfo(ThrowType);
4309 
4310  // Call into the runtime to throw the exception.
4311  llvm::Value *Args[] = {
4312  CGF.Builder.CreateBitCast(AI.getPointer(), CGM.Int8PtrTy),
4313  TI
4314  };
4316 }
4317 
4318 std::pair<llvm::Value *, const CXXRecordDecl *>
4319 MicrosoftCXXABI::LoadVTablePtr(CodeGenFunction &CGF, Address This,
4320  const CXXRecordDecl *RD) {
4321  std::tie(This, std::ignore, RD) =
4322  performBaseAdjustment(CGF, This, QualType(RD->getTypeForDecl(), 0));
4323  return {CGF.GetVTablePtr(This, CGM.Int8PtrTy, RD), RD};
4324 }
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:359
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:299
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:1555
Complete object ctor.
Definition: ABI.h:25
A (possibly-)qualified type.
Definition: Type.h:654
static llvm::CallBase * emitRTtypeidCall(CodeGenFunction &CGF, llvm::Value *Argument)
base_class_range bases()
Definition: DeclCXX.h:587
llvm::Type * ConvertTypeForMem(QualType T)
unsigned getNumBases() const
Retrieves the number of base classes of this class.
Definition: DeclCXX.h:581
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:1162
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:994
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:602
QualType getThisType() const
Return the type of the this pointer.
Definition: DeclCXX.cpp:2352
bool isEmpty() const
Definition: ABI.h:86
const Type * getTypeForDecl() const
Definition: Decl.h:3053
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:4086
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:251
bool isVirtual() const
Definition: DeclCXX.h:1976
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:198
bool isPOD() const
Whether this class is a POD-type (C++ [class]p4)
Definition: DeclCXX.h:1084
const RecordDecl * getParent() const
Returns the parent of this field declaration, which is the struct in which this field is defined...
Definition: Decl.h:2918
The base class of the type hierarchy.
Definition: Type.h:1450
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:1300
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:3721
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:2383
bool TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D)
Try to emit a base destructor as an alias to its primary base-class destructor.
Definition: CGCXX.cpp:34
static llvm::FunctionCallee getInitThreadFooterFn(CodeGenModule &CGM)
Default closure variant of a ctor.
Definition: ABI.h:29
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2544
const CXXBaseSpecifier *const * path_const_iterator
Definition: Expr.h:3219
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:820
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:7002
bool This(InterpState &S, CodePtr OpPC)
Definition: Interp.h:827
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:2414
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:1140
bool hasDefinition() const
Definition: DeclCXX.h:540
Represents a parameter to a function.
Definition: Decl.h:1595
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:285
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:272
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:168
bool inheritanceModelHasOnlyOneField(bool IsMemberFunction, MSInheritanceModel Inheritance)
virtual void mangleCXXVFTable(const CXXRecordDecl *Derived, ArrayRef< const CXXRecordDecl *> BasePath, raw_ostream &Out)=0
Mangle vftable symbols.
Represents a member of a struct/union/class.
Definition: Decl.h:2729
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:2788
bool Zero(InterpState &S, CodePtr OpPC)
Definition: Interp.h:812
bool isReferenceType() const
Definition: Type.h:6516
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:3202
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:263
Describes a module or submodule.
Definition: Module.h:64
static llvm::FunctionCallee getThrowFn(CodeGenModule &CGM)
IdentifierTable & Idents
Definition: ASTContext.h:580
bool hasPrivateFields() const
Definition: DeclCXX.h:1101
bool hasProtectedFields() const
Definition: DeclCXX.h:1105
static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF)
Apply TemporaryLocation if it is valid.
Definition: CGDebugInfo.h:769
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2399
static bool hasMicrosoftABIRestrictions(const CXXRecordDecl *RD)
ArrayRef< VTableComponent > vtable_components() const
FunctionDecl * getOperatorDelete() const
Definition: ExprCXX.h:2399
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:2638
AccessSpecifier getAccessSpecifier() const
Returns the access specifier for this base specifier.
Definition: DeclCXX.h:225
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:3222
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
MSInheritanceModel
Assigned inheritance model for a class in the MS C++ ABI.
Definition: Specifiers.h:359
static ConstantAddress getInitThreadEpochPtr(CodeGenModule &CGM)
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6326
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:390
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:6256
CXXRecordDecl * getCanonicalDecl() override
Retrieves the "canonical" declaration of the given declaration.
Definition: DeclCXX.h:492
void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr, QualType DeleteTy, llvm::Value *NumElements=nullptr, CharUnits CookieSize=CharUnits())
Definition: CGExprCXX.cpp:1765
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:3150
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:279
GlobalDecl CurGD
CurGD - The GlobalDecl for the current function being compiled.
bool isInstance() const
Definition: DeclCXX.h:1959
CXXDestructorDecl * getDestructor() const
Returns the destructor decl for this class.
Definition: DeclCXX.cpp:1770
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:518
static ImplicitParamDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, ImplicitParamKind ParamKind)
Create implicit parameter.
Definition: Decl.cpp:4685
NodeId Parent
Definition: ASTDiff.cpp:191
bool hasAttr() const
Definition: DeclBase.h:542
CanQualType getReturnType() const
bool inheritanceModelHasVBTableOffsetField(MSInheritanceModel Inheritance)
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:1379
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1690
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3754
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:39
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
struct clang::ReturnAdjustment::VirtualAdjustment::@136 Microsoft
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
unsigned Offset
Definition: Format.cpp:1827
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:2588
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:619
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:695
static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM)
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:7067
static CGCallee forDirect(llvm::Constant *functionPtr, const CGCalleeInfo &abstractInfo=CGCalleeInfo())
Definition: CGCall.h:133
#define V(N, I)
Definition: ASTContext.h:2941
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2649
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:6802
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:1998
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:160
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:1117
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:1279
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:1784
void GenerateCXXGlobalInitFunc(llvm::Function *Fn, ArrayRef< llvm::Function *> CXXThreadLocals, ConstantAddress Guard=ConstantAddress::invalid())
GenerateCXXGlobalInitFunc - Generates code for initializing global variables.
Definition: CGDeclCXX.cpp:671
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:174
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:1417
ASTContext & getContext() const
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:719
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
struct clang::ThisAdjustment::VirtualAdjustment::@138 Microsoft
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:6315
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:2863
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:3196
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:3814
Represents a new-expression for memory allocation and constructor calls, e.g: "new CXXNewExpr(foo)"...
Definition: ExprCXX.h:2100
Represents a call to a member function that may be written either with member call syntax (e...
Definition: ExprCXX.h:171
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:1931
const VTableLayout & getVFTableLayout(const CXXRecordDecl *RD, CharUnits VFPtrOffset)
QualType getAllocatedType() const
Definition: ExprCXX.h:2193
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:745
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:1174
unsigned getCustomDiagID(Level L, const char(&FormatString)[N])
Return an ID for a diagnostic with the specified format string and level.
Definition: Diagnostic.h:782
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:3898
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:224
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:355
llvm::Value * getScalarVal() const
getScalarVal() - Return the Value* of this scalar value.
Definition: CGValue.h:59
CXXRecordDecl * getMostRecentCXXRecordDecl() const
Definition: Type.cpp:4152
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:2359
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:2046
llvm::FunctionCallee CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeList ExtraAttrs=llvm::AttributeList(), bool Local=false, bool AssumeConvergent=false)
Create or return a runtime function declaration with the specified type and name. ...
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:2833
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:56
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:230
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:1237
path_iterator path_end()
Definition: Expr.h:3223
void EmitAutoVarCleanups(const AutoVarEmission &emission)
Definition: CGDecl.cpp:1980
void EmitNoreturnRuntimeCallOrInvoke(llvm::FunctionCallee callee, ArrayRef< llvm::Value *> args)
Emits a call or invoke to the given noreturn runtime function.
Definition: CGCall.cpp:3743
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:1069
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
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:473
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:145
bool isObjectType() const
Determine whether this type is an object type.
Definition: Type.h:1931
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2104
static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT, CGCXXABI &CXXABI)
Definition: TargetInfo.cpp:141
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:6336
Address CreateConstByteGEP(Address Addr, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:250
bool hasUnaligned() const
Definition: Type.h:299
Represents a C++ struct/union/class.
Definition: DeclCXX.h:253
bool isMemberFunctionPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2857
llvm::Function * CreateGlobalInitOrDestructFunction(llvm::FunctionType *ty, const Twine &name, const CGFunctionInfo &FI, SourceLocation Loc=SourceLocation(), bool TLS=false)
Definition: CGDeclCXX.cpp:336
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:6283
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:143
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:263
bool inheritanceModelHasNVOffsetField(bool IsMemberFunction, MSInheritanceModel Inheritance)
llvm::DenseMap< const CXXRecordDecl *, VBaseInfo > VBaseOffsetsMapTy
Definition: RecordLayout.h:59
bool isGlobalDelete() const
Definition: ExprCXX.h:2385
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:150
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:540
CanQualType IntTy
Definition: ASTContext.h:1025
Struct with all information about dynamic [sub]class needed to set vptr.
void initialize(TemplateInstantiationCallbackPtrs &Callbacks, const Sema &TheSema)
llvm::Function * codegenCXXStructor(GlobalDecl GD)
Definition: CGCXX.cpp:207
MethodVFTableLocation getMethodVFTableLocation(GlobalDecl GD)
static RValue get(llvm::Value *V)
Definition: CGValue.h:86
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:6504
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:786
llvm::StoreInst * CreateAlignedStore(llvm::Value *Val, llvm::Value *Addr, CharUnits Align, bool IsVolatile=false)
Definition: CGBuilder.h:114
QualType getType() const
Definition: Decl.h:630
uint32_t VBIndex
Index of the virtual base in the vbtable.
Definition: ABI.h:63
LValue - This represents an lvalue references.
Definition: CGValue.h:167
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:146
This represents a decl that may have a name.
Definition: Decl.h:223
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:390
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.
bool nullFieldOffsetIsZero() const
In the Microsoft C++ ABI, use zero for the field offset of a null data member pointer if we can guara...
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:3774
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3242
ctor_range ctors() const
Definition: DeclCXX.h:649
MSInheritanceModel getMSInheritanceModel() const
Returns the inheritance model used for this record.
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:261
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.
bool inheritanceModelHasVBPtrOffsetField(MSInheritanceModel Inheritance)
base_class_range vbases()
Definition: DeclCXX.h:604
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:2805
SourceLocation getLocation() const
Definition: DeclBase.h:429
QualType getPointeeType() const
Definition: Type.h:2853
bool isExternallyVisible() const
Definition: Decl.h:362
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:1556
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:2606