clang  5.0.0
MicrosoftCXXABI.cpp
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1 //===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This provides C++ code generation targeting the Microsoft Visual C++ ABI.
11 // The class in this file generates structures that follow the Microsoft
12 // Visual C++ ABI, which is actually not very well documented at all outside
13 // of Microsoft.
14 //
15 //===----------------------------------------------------------------------===//
16 
17 #include "CGCXXABI.h"
18 #include "CGCleanup.h"
19 #include "CGVTables.h"
20 #include "CodeGenModule.h"
21 #include "CodeGenTypes.h"
22 #include "TargetInfo.h"
24 #include "clang/AST/Decl.h"
25 #include "clang/AST/DeclCXX.h"
26 #include "clang/AST/StmtCXX.h"
28 #include "llvm/ADT/StringExtras.h"
29 #include "llvm/ADT/StringSet.h"
30 #include "llvm/IR/CallSite.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(const CXXMethodDecl *MD, StructorType T,
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 EmitCXXDestructors(const CXXDestructorDecl *D) override;
220 
221  const CXXRecordDecl *
222  getThisArgumentTypeForMethod(const CXXMethodDecl *MD) override {
223  MD = MD->getCanonicalDecl();
224  if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
226  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD);
227  // The vbases might be ordered differently in the final overrider object
228  // and the complete object, so the "this" argument may sometimes point to
229  // memory that has no particular type (e.g. past the complete object).
230  // In this case, we just use a generic pointer type.
231  // FIXME: might want to have a more precise type in the non-virtual
232  // multiple inheritance case.
233  if (ML.VBase || !ML.VFPtrOffset.isZero())
234  return nullptr;
235  }
236  return MD->getParent();
237  }
238 
239  Address
240  adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
241  Address This,
242  bool VirtualCall) override;
243 
244  void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
245  FunctionArgList &Params) override;
246 
247  llvm::Value *adjustThisParameterInVirtualFunctionPrologue(
248  CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) override;
249 
250  void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override;
251 
252  AddedStructorArgs
253  addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
254  CXXCtorType Type, bool ForVirtualBase,
255  bool Delegating, CallArgList &Args) override;
256 
257  void EmitDestructorCall(CodeGenFunction &CGF, const CXXDestructorDecl *DD,
258  CXXDtorType Type, bool ForVirtualBase,
259  bool Delegating, Address This) override;
260 
261  void emitVTableTypeMetadata(const VPtrInfo &Info, const CXXRecordDecl *RD,
262  llvm::GlobalVariable *VTable);
263 
264  void emitVTableDefinitions(CodeGenVTables &CGVT,
265  const CXXRecordDecl *RD) override;
266 
267  bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
268  CodeGenFunction::VPtr Vptr) override;
269 
270  /// Don't initialize vptrs if dynamic class
271  /// is marked with with the 'novtable' attribute.
272  bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
273  return !VTableClass->hasAttr<MSNoVTableAttr>();
274  }
275 
276  llvm::Constant *
277  getVTableAddressPoint(BaseSubobject Base,
278  const CXXRecordDecl *VTableClass) override;
279 
280  llvm::Value *getVTableAddressPointInStructor(
281  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
282  BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
283 
284  llvm::Constant *
285  getVTableAddressPointForConstExpr(BaseSubobject Base,
286  const CXXRecordDecl *VTableClass) override;
287 
288  llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
289  CharUnits VPtrOffset) override;
290 
291  CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
292  Address This, llvm::Type *Ty,
293  SourceLocation Loc) override;
294 
295  llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
296  const CXXDestructorDecl *Dtor,
297  CXXDtorType DtorType,
298  Address This,
299  const CXXMemberCallExpr *CE) override;
300 
301  void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
302  CallArgList &CallArgs) override {
303  assert(GD.getDtorType() == Dtor_Deleting &&
304  "Only deleting destructor thunks are available in this ABI");
305  CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
306  getContext().IntTy);
307  }
308 
309  void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
310 
311  llvm::GlobalVariable *
312  getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
313  llvm::GlobalVariable::LinkageTypes Linkage);
314 
315  llvm::GlobalVariable *
316  getAddrOfVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
317  const CXXRecordDecl *DstRD) {
318  SmallString<256> OutName;
319  llvm::raw_svector_ostream Out(OutName);
320  getMangleContext().mangleCXXVirtualDisplacementMap(SrcRD, DstRD, Out);
321  StringRef MangledName = OutName.str();
322 
323  if (auto *VDispMap = CGM.getModule().getNamedGlobal(MangledName))
324  return VDispMap;
325 
326  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
327  unsigned NumEntries = 1 + SrcRD->getNumVBases();
329  llvm::UndefValue::get(CGM.IntTy));
330  Map[0] = llvm::ConstantInt::get(CGM.IntTy, 0);
331  bool AnyDifferent = false;
332  for (const auto &I : SrcRD->vbases()) {
333  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
334  if (!DstRD->isVirtuallyDerivedFrom(VBase))
335  continue;
336 
337  unsigned SrcVBIndex = VTContext.getVBTableIndex(SrcRD, VBase);
338  unsigned DstVBIndex = VTContext.getVBTableIndex(DstRD, VBase);
339  Map[SrcVBIndex] = llvm::ConstantInt::get(CGM.IntTy, DstVBIndex * 4);
340  AnyDifferent |= SrcVBIndex != DstVBIndex;
341  }
342  // This map would be useless, don't use it.
343  if (!AnyDifferent)
344  return nullptr;
345 
346  llvm::ArrayType *VDispMapTy = llvm::ArrayType::get(CGM.IntTy, Map.size());
347  llvm::Constant *Init = llvm::ConstantArray::get(VDispMapTy, Map);
348  llvm::GlobalValue::LinkageTypes Linkage =
349  SrcRD->isExternallyVisible() && DstRD->isExternallyVisible()
350  ? llvm::GlobalValue::LinkOnceODRLinkage
352  auto *VDispMap = new llvm::GlobalVariable(
353  CGM.getModule(), VDispMapTy, /*Constant=*/true, Linkage,
354  /*Initializer=*/Init, MangledName);
355  return VDispMap;
356  }
357 
358  void emitVBTableDefinition(const VPtrInfo &VBT, const CXXRecordDecl *RD,
359  llvm::GlobalVariable *GV) const;
360 
361  void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
362  GlobalDecl GD, bool ReturnAdjustment) override {
363  // Never dllimport/dllexport thunks.
364  Thunk->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
365 
366  GVALinkage Linkage =
367  getContext().GetGVALinkageForFunction(cast<FunctionDecl>(GD.getDecl()));
368 
369  if (Linkage == GVA_Internal)
370  Thunk->setLinkage(llvm::GlobalValue::InternalLinkage);
371  else if (ReturnAdjustment)
372  Thunk->setLinkage(llvm::GlobalValue::WeakODRLinkage);
373  else
374  Thunk->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
375  }
376 
377  llvm::Value *performThisAdjustment(CodeGenFunction &CGF, Address This,
378  const ThisAdjustment &TA) override;
379 
380  llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
381  const ReturnAdjustment &RA) override;
382 
383  void EmitThreadLocalInitFuncs(
384  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
385  ArrayRef<llvm::Function *> CXXThreadLocalInits,
386  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) override;
387 
388  bool usesThreadWrapperFunction() const override { return false; }
389  LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF, const VarDecl *VD,
390  QualType LValType) override;
391 
392  void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
393  llvm::GlobalVariable *DeclPtr,
394  bool PerformInit) override;
395  void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
396  llvm::Constant *Dtor, llvm::Constant *Addr) override;
397 
398  // ==== Notes on array cookies =========
399  //
400  // MSVC seems to only use cookies when the class has a destructor; a
401  // two-argument usual array deallocation function isn't sufficient.
402  //
403  // For example, this code prints "100" and "1":
404  // struct A {
405  // char x;
406  // void *operator new[](size_t sz) {
407  // printf("%u\n", sz);
408  // return malloc(sz);
409  // }
410  // void operator delete[](void *p, size_t sz) {
411  // printf("%u\n", sz);
412  // free(p);
413  // }
414  // };
415  // int main() {
416  // A *p = new A[100];
417  // delete[] p;
418  // }
419  // Whereas it prints "104" and "104" if you give A a destructor.
420 
421  bool requiresArrayCookie(const CXXDeleteExpr *expr,
422  QualType elementType) override;
423  bool requiresArrayCookie(const CXXNewExpr *expr) override;
424  CharUnits getArrayCookieSizeImpl(QualType type) override;
425  Address InitializeArrayCookie(CodeGenFunction &CGF,
426  Address NewPtr,
427  llvm::Value *NumElements,
428  const CXXNewExpr *expr,
429  QualType ElementType) override;
430  llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
431  Address allocPtr,
432  CharUnits cookieSize) override;
433 
434  friend struct MSRTTIBuilder;
435 
436  bool isImageRelative() const {
437  return CGM.getTarget().getPointerWidth(/*AddressSpace=*/0) == 64;
438  }
439 
440  // 5 routines for constructing the llvm types for MS RTTI structs.
441  llvm::StructType *getTypeDescriptorType(StringRef TypeInfoString) {
442  llvm::SmallString<32> TDTypeName("rtti.TypeDescriptor");
443  TDTypeName += llvm::utostr(TypeInfoString.size());
444  llvm::StructType *&TypeDescriptorType =
445  TypeDescriptorTypeMap[TypeInfoString.size()];
446  if (TypeDescriptorType)
447  return TypeDescriptorType;
448  llvm::Type *FieldTypes[] = {
449  CGM.Int8PtrPtrTy,
450  CGM.Int8PtrTy,
451  llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
452  TypeDescriptorType =
453  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
454  return TypeDescriptorType;
455  }
456 
457  llvm::Type *getImageRelativeType(llvm::Type *PtrType) {
458  if (!isImageRelative())
459  return PtrType;
460  return CGM.IntTy;
461  }
462 
463  llvm::StructType *getBaseClassDescriptorType() {
464  if (BaseClassDescriptorType)
465  return BaseClassDescriptorType;
466  llvm::Type *FieldTypes[] = {
467  getImageRelativeType(CGM.Int8PtrTy),
468  CGM.IntTy,
469  CGM.IntTy,
470  CGM.IntTy,
471  CGM.IntTy,
472  CGM.IntTy,
473  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
474  };
475  BaseClassDescriptorType = llvm::StructType::create(
476  CGM.getLLVMContext(), FieldTypes, "rtti.BaseClassDescriptor");
477  return BaseClassDescriptorType;
478  }
479 
480  llvm::StructType *getClassHierarchyDescriptorType() {
481  if (ClassHierarchyDescriptorType)
482  return ClassHierarchyDescriptorType;
483  // Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
484  ClassHierarchyDescriptorType = llvm::StructType::create(
485  CGM.getLLVMContext(), "rtti.ClassHierarchyDescriptor");
486  llvm::Type *FieldTypes[] = {
487  CGM.IntTy,
488  CGM.IntTy,
489  CGM.IntTy,
490  getImageRelativeType(
491  getBaseClassDescriptorType()->getPointerTo()->getPointerTo()),
492  };
493  ClassHierarchyDescriptorType->setBody(FieldTypes);
494  return ClassHierarchyDescriptorType;
495  }
496 
497  llvm::StructType *getCompleteObjectLocatorType() {
498  if (CompleteObjectLocatorType)
499  return CompleteObjectLocatorType;
500  CompleteObjectLocatorType = llvm::StructType::create(
501  CGM.getLLVMContext(), "rtti.CompleteObjectLocator");
502  llvm::Type *FieldTypes[] = {
503  CGM.IntTy,
504  CGM.IntTy,
505  CGM.IntTy,
506  getImageRelativeType(CGM.Int8PtrTy),
507  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
508  getImageRelativeType(CompleteObjectLocatorType),
509  };
510  llvm::ArrayRef<llvm::Type *> FieldTypesRef(FieldTypes);
511  if (!isImageRelative())
512  FieldTypesRef = FieldTypesRef.drop_back();
513  CompleteObjectLocatorType->setBody(FieldTypesRef);
514  return CompleteObjectLocatorType;
515  }
516 
517  llvm::GlobalVariable *getImageBase() {
518  StringRef Name = "__ImageBase";
519  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
520  return GV;
521 
522  return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
523  /*isConstant=*/true,
525  /*Initializer=*/nullptr, Name);
526  }
527 
528  llvm::Constant *getImageRelativeConstant(llvm::Constant *PtrVal) {
529  if (!isImageRelative())
530  return PtrVal;
531 
532  if (PtrVal->isNullValue())
533  return llvm::Constant::getNullValue(CGM.IntTy);
534 
535  llvm::Constant *ImageBaseAsInt =
536  llvm::ConstantExpr::getPtrToInt(getImageBase(), CGM.IntPtrTy);
537  llvm::Constant *PtrValAsInt =
538  llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
539  llvm::Constant *Diff =
540  llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
541  /*HasNUW=*/true, /*HasNSW=*/true);
542  return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
543  }
544 
545 private:
546  MicrosoftMangleContext &getMangleContext() {
547  return cast<MicrosoftMangleContext>(CodeGen::CGCXXABI::getMangleContext());
548  }
549 
550  llvm::Constant *getZeroInt() {
551  return llvm::ConstantInt::get(CGM.IntTy, 0);
552  }
553 
554  llvm::Constant *getAllOnesInt() {
555  return llvm::Constant::getAllOnesValue(CGM.IntTy);
556  }
557 
558  CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) override;
559 
560  void
561  GetNullMemberPointerFields(const MemberPointerType *MPT,
563 
564  /// \brief Shared code for virtual base adjustment. Returns the offset from
565  /// the vbptr to the virtual base. Optionally returns the address of the
566  /// vbptr itself.
567  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
568  Address Base,
569  llvm::Value *VBPtrOffset,
570  llvm::Value *VBTableOffset,
571  llvm::Value **VBPtr = nullptr);
572 
573  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
574  Address Base,
575  int32_t VBPtrOffset,
576  int32_t VBTableOffset,
577  llvm::Value **VBPtr = nullptr) {
578  assert(VBTableOffset % 4 == 0 && "should be byte offset into table of i32s");
579  llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
580  *VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset);
581  return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr);
582  }
583 
584  std::pair<Address, llvm::Value *>
585  performBaseAdjustment(CodeGenFunction &CGF, Address Value,
586  QualType SrcRecordTy);
587 
588  /// \brief Performs a full virtual base adjustment. Used to dereference
589  /// pointers to members of virtual bases.
590  llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const Expr *E,
591  const CXXRecordDecl *RD, Address Base,
592  llvm::Value *VirtualBaseAdjustmentOffset,
593  llvm::Value *VBPtrOffset /* optional */);
594 
595  /// \brief Emits a full member pointer with the fields common to data and
596  /// function member pointers.
597  llvm::Constant *EmitFullMemberPointer(llvm::Constant *FirstField,
598  bool IsMemberFunction,
599  const CXXRecordDecl *RD,
600  CharUnits NonVirtualBaseAdjustment,
601  unsigned VBTableIndex);
602 
603  bool MemberPointerConstantIsNull(const MemberPointerType *MPT,
604  llvm::Constant *MP);
605 
606  /// \brief - Initialize all vbptrs of 'this' with RD as the complete type.
607  void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD);
608 
609  /// \brief Caching wrapper around VBTableBuilder::enumerateVBTables().
610  const VBTableGlobals &enumerateVBTables(const CXXRecordDecl *RD);
611 
612  /// \brief Generate a thunk for calling a virtual member function MD.
613  llvm::Function *EmitVirtualMemPtrThunk(
614  const CXXMethodDecl *MD,
616 
617 public:
618  llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
619 
620  bool isZeroInitializable(const MemberPointerType *MPT) override;
621 
622  bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
623  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
624  return RD->hasAttr<MSInheritanceAttr>();
625  }
626 
627  llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
628 
629  llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
630  CharUnits offset) override;
631  llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
632  llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
633 
634  llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
635  llvm::Value *L,
636  llvm::Value *R,
637  const MemberPointerType *MPT,
638  bool Inequality) override;
639 
640  llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
641  llvm::Value *MemPtr,
642  const MemberPointerType *MPT) override;
643 
644  llvm::Value *
645  EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
646  Address Base, llvm::Value *MemPtr,
647  const MemberPointerType *MPT) override;
648 
649  llvm::Value *EmitNonNullMemberPointerConversion(
650  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
654 
655  llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
656  const CastExpr *E,
657  llvm::Value *Src) override;
658 
659  llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
660  llvm::Constant *Src) override;
661 
662  llvm::Constant *EmitMemberPointerConversion(
663  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
665  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src);
666 
667  CGCallee
668  EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, const Expr *E,
669  Address This, llvm::Value *&ThisPtrForCall,
670  llvm::Value *MemPtr,
671  const MemberPointerType *MPT) override;
672 
673  void emitCXXStructor(const CXXMethodDecl *MD, StructorType Type) override;
674 
675  llvm::StructType *getCatchableTypeType() {
676  if (CatchableTypeType)
677  return CatchableTypeType;
678  llvm::Type *FieldTypes[] = {
679  CGM.IntTy, // Flags
680  getImageRelativeType(CGM.Int8PtrTy), // TypeDescriptor
681  CGM.IntTy, // NonVirtualAdjustment
682  CGM.IntTy, // OffsetToVBPtr
683  CGM.IntTy, // VBTableIndex
684  CGM.IntTy, // Size
685  getImageRelativeType(CGM.Int8PtrTy) // CopyCtor
686  };
687  CatchableTypeType = llvm::StructType::create(
688  CGM.getLLVMContext(), FieldTypes, "eh.CatchableType");
689  return CatchableTypeType;
690  }
691 
692  llvm::StructType *getCatchableTypeArrayType(uint32_t NumEntries) {
693  llvm::StructType *&CatchableTypeArrayType =
694  CatchableTypeArrayTypeMap[NumEntries];
695  if (CatchableTypeArrayType)
696  return CatchableTypeArrayType;
697 
698  llvm::SmallString<23> CTATypeName("eh.CatchableTypeArray.");
699  CTATypeName += llvm::utostr(NumEntries);
700  llvm::Type *CTType =
701  getImageRelativeType(getCatchableTypeType()->getPointerTo());
702  llvm::Type *FieldTypes[] = {
703  CGM.IntTy, // NumEntries
704  llvm::ArrayType::get(CTType, NumEntries) // CatchableTypes
705  };
706  CatchableTypeArrayType =
707  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, CTATypeName);
708  return CatchableTypeArrayType;
709  }
710 
711  llvm::StructType *getThrowInfoType() {
712  if (ThrowInfoType)
713  return ThrowInfoType;
714  llvm::Type *FieldTypes[] = {
715  CGM.IntTy, // Flags
716  getImageRelativeType(CGM.Int8PtrTy), // CleanupFn
717  getImageRelativeType(CGM.Int8PtrTy), // ForwardCompat
718  getImageRelativeType(CGM.Int8PtrTy) // CatchableTypeArray
719  };
720  ThrowInfoType = llvm::StructType::create(CGM.getLLVMContext(), FieldTypes,
721  "eh.ThrowInfo");
722  return ThrowInfoType;
723  }
724 
725  llvm::Constant *getThrowFn() {
726  // _CxxThrowException is passed an exception object and a ThrowInfo object
727  // which describes the exception.
728  llvm::Type *Args[] = {CGM.Int8PtrTy, getThrowInfoType()->getPointerTo()};
729  llvm::FunctionType *FTy =
730  llvm::FunctionType::get(CGM.VoidTy, Args, /*IsVarArgs=*/false);
731  auto *Fn = cast<llvm::Function>(
732  CGM.CreateRuntimeFunction(FTy, "_CxxThrowException"));
733  // _CxxThrowException is stdcall on 32-bit x86 platforms.
734  if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86)
735  Fn->setCallingConv(llvm::CallingConv::X86_StdCall);
736  return Fn;
737  }
738 
739  llvm::Function *getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
740  CXXCtorType CT);
741 
742  llvm::Constant *getCatchableType(QualType T,
743  uint32_t NVOffset = 0,
744  int32_t VBPtrOffset = -1,
745  uint32_t VBIndex = 0);
746 
747  llvm::GlobalVariable *getCatchableTypeArray(QualType T);
748 
749  llvm::GlobalVariable *getThrowInfo(QualType T) override;
750 
751 private:
752  typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy;
753  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VTablesMapTy;
754  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalValue *> VFTablesMapTy;
755  /// \brief All the vftables that have been referenced.
756  VFTablesMapTy VFTablesMap;
757  VTablesMapTy VTablesMap;
758 
759  /// \brief This set holds the record decls we've deferred vtable emission for.
760  llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables;
761 
762 
763  /// \brief All the vbtables which have been referenced.
764  llvm::DenseMap<const CXXRecordDecl *, VBTableGlobals> VBTablesMap;
765 
766  /// Info on the global variable used to guard initialization of static locals.
767  /// The BitIndex field is only used for externally invisible declarations.
768  struct GuardInfo {
769  GuardInfo() : Guard(nullptr), BitIndex(0) {}
770  llvm::GlobalVariable *Guard;
771  unsigned BitIndex;
772  };
773 
774  /// Map from DeclContext to the current guard variable. We assume that the
775  /// AST is visited in source code order.
776  llvm::DenseMap<const DeclContext *, GuardInfo> GuardVariableMap;
777  llvm::DenseMap<const DeclContext *, GuardInfo> ThreadLocalGuardVariableMap;
778  llvm::DenseMap<const DeclContext *, unsigned> ThreadSafeGuardNumMap;
779 
780  llvm::DenseMap<size_t, llvm::StructType *> TypeDescriptorTypeMap;
781  llvm::StructType *BaseClassDescriptorType;
782  llvm::StructType *ClassHierarchyDescriptorType;
783  llvm::StructType *CompleteObjectLocatorType;
784 
785  llvm::DenseMap<QualType, llvm::GlobalVariable *> CatchableTypeArrays;
786 
787  llvm::StructType *CatchableTypeType;
788  llvm::DenseMap<uint32_t, llvm::StructType *> CatchableTypeArrayTypeMap;
789  llvm::StructType *ThrowInfoType;
790 };
791 
792 }
793 
796  switch (CGM.getTarget().getTriple().getArch()) {
797  default:
798  // FIXME: Implement for other architectures.
799  return RAA_Default;
800 
801  case llvm::Triple::thumb:
802  // Use the simple Itanium rules for now.
803  // FIXME: This is incompatible with MSVC for arguments with a dtor and no
804  // copy ctor.
805  return !canCopyArgument(RD) ? RAA_Indirect : RAA_Default;
806 
807  case llvm::Triple::x86:
808  // All record arguments are passed in memory on x86. Decide whether to
809  // construct the object directly in argument memory, or to construct the
810  // argument elsewhere and copy the bytes during the call.
811 
812  // If C++ prohibits us from making a copy, construct the arguments directly
813  // into argument memory.
814  if (!canCopyArgument(RD))
815  return RAA_DirectInMemory;
816 
817  // Otherwise, construct the argument into a temporary and copy the bytes
818  // into the outgoing argument memory.
819  return RAA_Default;
820 
821  case llvm::Triple::x86_64:
822  // If a class has a destructor, we'd really like to pass it indirectly
823  // because it allows us to elide copies. Unfortunately, MSVC makes that
824  // impossible for small types, which it will pass in a single register or
825  // stack slot. Most objects with dtors are large-ish, so handle that early.
826  // We can't call out all large objects as being indirect because there are
827  // multiple x64 calling conventions and the C++ ABI code shouldn't dictate
828  // how we pass large POD types.
829  //
830  // Note: This permits small classes with nontrivial destructors to be
831  // passed in registers, which is non-conforming.
832  if (RD->hasNonTrivialDestructor() &&
833  getContext().getTypeSize(RD->getTypeForDecl()) > 64)
834  return RAA_Indirect;
835 
836  // If a class has at least one non-deleted, trivial copy constructor, it
837  // is passed according to the C ABI. Otherwise, it is passed indirectly.
838  //
839  // Note: This permits classes with non-trivial copy or move ctors to be
840  // passed in registers, so long as they *also* have a trivial copy ctor,
841  // which is non-conforming.
842  if (RD->needsImplicitCopyConstructor()) {
843  // If the copy ctor has not yet been declared, we can read its triviality
844  // off the AST.
847  return RAA_Default;
848  } else {
849  // Otherwise, we need to find the copy constructor(s) and ask.
850  for (const CXXConstructorDecl *CD : RD->ctors()) {
851  if (CD->isCopyConstructor()) {
852  // We had at least one nondeleted trivial copy ctor. Return directly.
853  if (!CD->isDeleted() && CD->isTrivial())
854  return RAA_Default;
855  }
856  }
857  }
858 
859  // We have no trivial, non-deleted copy constructor.
860  return RAA_Indirect;
861  }
862 
863  llvm_unreachable("invalid enum");
864 }
865 
866 void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
867  const CXXDeleteExpr *DE,
868  Address Ptr,
869  QualType ElementType,
870  const CXXDestructorDecl *Dtor) {
871  // FIXME: Provide a source location here even though there's no
872  // CXXMemberCallExpr for dtor call.
873  bool UseGlobalDelete = DE->isGlobalDelete();
874  CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
875  llvm::Value *MDThis =
876  EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, /*CE=*/nullptr);
877  if (UseGlobalDelete)
878  CGF.EmitDeleteCall(DE->getOperatorDelete(), MDThis, ElementType);
879 }
880 
881 void MicrosoftCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
882  llvm::Value *Args[] = {
883  llvm::ConstantPointerNull::get(CGM.Int8PtrTy),
884  llvm::ConstantPointerNull::get(getThrowInfoType()->getPointerTo())};
885  auto *Fn = getThrowFn();
886  if (isNoReturn)
887  CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, Args);
888  else
889  CGF.EmitRuntimeCallOrInvoke(Fn, Args);
890 }
891 
892 namespace {
893 struct CatchRetScope final : EHScopeStack::Cleanup {
894  llvm::CatchPadInst *CPI;
895 
896  CatchRetScope(llvm::CatchPadInst *CPI) : CPI(CPI) {}
897 
898  void Emit(CodeGenFunction &CGF, Flags flags) override {
899  llvm::BasicBlock *BB = CGF.createBasicBlock("catchret.dest");
900  CGF.Builder.CreateCatchRet(CPI, BB);
901  CGF.EmitBlock(BB);
902  }
903 };
904 }
905 
906 void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
907  const CXXCatchStmt *S) {
908  // In the MS ABI, the runtime handles the copy, and the catch handler is
909  // responsible for destruction.
910  VarDecl *CatchParam = S->getExceptionDecl();
911  llvm::BasicBlock *CatchPadBB = CGF.Builder.GetInsertBlock();
912  llvm::CatchPadInst *CPI =
913  cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
914  CGF.CurrentFuncletPad = CPI;
915 
916  // If this is a catch-all or the catch parameter is unnamed, we don't need to
917  // emit an alloca to the object.
918  if (!CatchParam || !CatchParam->getDeclName()) {
919  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
920  return;
921  }
922 
924  CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
925  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
926  CGF.EmitAutoVarCleanups(var);
927 }
928 
929 /// We need to perform a generic polymorphic operation (like a typeid
930 /// or a cast), which requires an object with a vfptr. Adjust the
931 /// address to point to an object with a vfptr.
932 std::pair<Address, llvm::Value *>
933 MicrosoftCXXABI::performBaseAdjustment(CodeGenFunction &CGF, Address Value,
934  QualType SrcRecordTy) {
935  Value = CGF.Builder.CreateBitCast(Value, CGF.Int8PtrTy);
936  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
937  const ASTContext &Context = getContext();
938 
939  // If the class itself has a vfptr, great. This check implicitly
940  // covers non-virtual base subobjects: a class with its own virtual
941  // functions would be a candidate to be a primary base.
942  if (Context.getASTRecordLayout(SrcDecl).hasExtendableVFPtr())
943  return std::make_pair(Value, llvm::ConstantInt::get(CGF.Int32Ty, 0));
944 
945  // Okay, one of the vbases must have a vfptr, or else this isn't
946  // actually a polymorphic class.
947  const CXXRecordDecl *PolymorphicBase = nullptr;
948  for (auto &Base : SrcDecl->vbases()) {
949  const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
950  if (Context.getASTRecordLayout(BaseDecl).hasExtendableVFPtr()) {
951  PolymorphicBase = BaseDecl;
952  break;
953  }
954  }
955  assert(PolymorphicBase && "polymorphic class has no apparent vfptr?");
956 
958  GetVirtualBaseClassOffset(CGF, Value, SrcDecl, PolymorphicBase);
959  llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(Value.getPointer(), Offset);
960  CharUnits VBaseAlign =
961  CGF.CGM.getVBaseAlignment(Value.getAlignment(), SrcDecl, PolymorphicBase);
962  return std::make_pair(Address(Ptr, VBaseAlign), Offset);
963 }
964 
965 bool MicrosoftCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
966  QualType SrcRecordTy) {
967  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
968  return IsDeref &&
969  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
970 }
971 
972 static llvm::CallSite emitRTtypeidCall(CodeGenFunction &CGF,
973  llvm::Value *Argument) {
974  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
975  llvm::FunctionType *FTy =
976  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false);
977  llvm::Value *Args[] = {Argument};
978  llvm::Constant *Fn = CGF.CGM.CreateRuntimeFunction(FTy, "__RTtypeid");
979  return CGF.EmitRuntimeCallOrInvoke(Fn, Args);
980 }
981 
982 void MicrosoftCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
983  llvm::CallSite Call =
984  emitRTtypeidCall(CGF, llvm::Constant::getNullValue(CGM.VoidPtrTy));
985  Call.setDoesNotReturn();
986  CGF.Builder.CreateUnreachable();
987 }
988 
989 llvm::Value *MicrosoftCXXABI::EmitTypeid(CodeGenFunction &CGF,
990  QualType SrcRecordTy,
991  Address ThisPtr,
992  llvm::Type *StdTypeInfoPtrTy) {
993  std::tie(ThisPtr, std::ignore) =
994  performBaseAdjustment(CGF, ThisPtr, SrcRecordTy);
995  auto Typeid = emitRTtypeidCall(CGF, ThisPtr.getPointer()).getInstruction();
996  return CGF.Builder.CreateBitCast(Typeid, StdTypeInfoPtrTy);
997 }
998 
999 bool MicrosoftCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
1000  QualType SrcRecordTy) {
1001  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
1002  return SrcIsPtr &&
1003  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
1004 }
1005 
1006 llvm::Value *MicrosoftCXXABI::EmitDynamicCastCall(
1007  CodeGenFunction &CGF, Address This, QualType SrcRecordTy,
1008  QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
1009  llvm::Type *DestLTy = CGF.ConvertType(DestTy);
1010 
1011  llvm::Value *SrcRTTI =
1012  CGF.CGM.GetAddrOfRTTIDescriptor(SrcRecordTy.getUnqualifiedType());
1013  llvm::Value *DestRTTI =
1014  CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
1015 
1017  std::tie(This, Offset) = performBaseAdjustment(CGF, This, SrcRecordTy);
1018  llvm::Value *ThisPtr = This.getPointer();
1019  Offset = CGF.Builder.CreateTrunc(Offset, CGF.Int32Ty);
1020 
1021  // PVOID __RTDynamicCast(
1022  // PVOID inptr,
1023  // LONG VfDelta,
1024  // PVOID SrcType,
1025  // PVOID TargetType,
1026  // BOOL isReference)
1027  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy, CGF.Int32Ty, CGF.Int8PtrTy,
1028  CGF.Int8PtrTy, CGF.Int32Ty};
1029  llvm::Constant *Function = CGF.CGM.CreateRuntimeFunction(
1030  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
1031  "__RTDynamicCast");
1032  llvm::Value *Args[] = {
1033  ThisPtr, Offset, SrcRTTI, DestRTTI,
1034  llvm::ConstantInt::get(CGF.Int32Ty, DestTy->isReferenceType())};
1035  ThisPtr = CGF.EmitRuntimeCallOrInvoke(Function, Args).getInstruction();
1036  return CGF.Builder.CreateBitCast(ThisPtr, DestLTy);
1037 }
1038 
1039 llvm::Value *
1040 MicrosoftCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
1041  QualType SrcRecordTy,
1042  QualType DestTy) {
1043  std::tie(Value, std::ignore) = performBaseAdjustment(CGF, Value, SrcRecordTy);
1044 
1045  // PVOID __RTCastToVoid(
1046  // PVOID inptr)
1047  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
1048  llvm::Constant *Function = CGF.CGM.CreateRuntimeFunction(
1049  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
1050  "__RTCastToVoid");
1051  llvm::Value *Args[] = {Value.getPointer()};
1052  return CGF.EmitRuntimeCall(Function, Args);
1053 }
1054 
1055 bool MicrosoftCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
1056  return false;
1057 }
1058 
1059 llvm::Value *MicrosoftCXXABI::GetVirtualBaseClassOffset(
1060  CodeGenFunction &CGF, Address This, const CXXRecordDecl *ClassDecl,
1061  const CXXRecordDecl *BaseClassDecl) {
1062  const ASTContext &Context = getContext();
1063  int64_t VBPtrChars =
1064  Context.getASTRecordLayout(ClassDecl).getVBPtrOffset().getQuantity();
1065  llvm::Value *VBPtrOffset = llvm::ConstantInt::get(CGM.PtrDiffTy, VBPtrChars);
1066  CharUnits IntSize = Context.getTypeSizeInChars(Context.IntTy);
1067  CharUnits VBTableChars =
1068  IntSize *
1069  CGM.getMicrosoftVTableContext().getVBTableIndex(ClassDecl, BaseClassDecl);
1070  llvm::Value *VBTableOffset =
1071  llvm::ConstantInt::get(CGM.IntTy, VBTableChars.getQuantity());
1072 
1073  llvm::Value *VBPtrToNewBase =
1074  GetVBaseOffsetFromVBPtr(CGF, This, VBPtrOffset, VBTableOffset);
1075  VBPtrToNewBase =
1076  CGF.Builder.CreateSExtOrBitCast(VBPtrToNewBase, CGM.PtrDiffTy);
1077  return CGF.Builder.CreateNSWAdd(VBPtrOffset, VBPtrToNewBase);
1078 }
1079 
1080 bool MicrosoftCXXABI::HasThisReturn(GlobalDecl GD) const {
1081  return isa<CXXConstructorDecl>(GD.getDecl());
1082 }
1083 
1084 static bool isDeletingDtor(GlobalDecl GD) {
1085  return isa<CXXDestructorDecl>(GD.getDecl()) &&
1086  GD.getDtorType() == Dtor_Deleting;
1087 }
1088 
1089 bool MicrosoftCXXABI::hasMostDerivedReturn(GlobalDecl GD) const {
1090  return isDeletingDtor(GD);
1091 }
1092 
1094  const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
1095  if (!RD)
1096  return false;
1097 
1098  CharUnits Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
1099  if (FI.isInstanceMethod()) {
1100  // If it's an instance method, aggregates are always returned indirectly via
1101  // the second parameter.
1102  FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
1104  return true;
1105  } else if (!RD->isPOD()) {
1106  // If it's a free function, non-POD types are returned indirectly.
1107  FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
1108  return true;
1109  }
1110 
1111  // Otherwise, use the C ABI rules.
1112  return false;
1113 }
1114 
1115 llvm::BasicBlock *
1116 MicrosoftCXXABI::EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
1117  const CXXRecordDecl *RD) {
1118  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1119  assert(IsMostDerivedClass &&
1120  "ctor for a class with virtual bases must have an implicit parameter");
1121  llvm::Value *IsCompleteObject =
1122  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1123 
1124  llvm::BasicBlock *CallVbaseCtorsBB = CGF.createBasicBlock("ctor.init_vbases");
1125  llvm::BasicBlock *SkipVbaseCtorsBB = CGF.createBasicBlock("ctor.skip_vbases");
1126  CGF.Builder.CreateCondBr(IsCompleteObject,
1127  CallVbaseCtorsBB, SkipVbaseCtorsBB);
1128 
1129  CGF.EmitBlock(CallVbaseCtorsBB);
1130 
1131  // Fill in the vbtable pointers here.
1132  EmitVBPtrStores(CGF, RD);
1133 
1134  // CGF will put the base ctor calls in this basic block for us later.
1135 
1136  return SkipVbaseCtorsBB;
1137 }
1138 
1139 llvm::BasicBlock *
1140 MicrosoftCXXABI::EmitDtorCompleteObjectHandler(CodeGenFunction &CGF) {
1141  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1142  assert(IsMostDerivedClass &&
1143  "ctor for a class with virtual bases must have an implicit parameter");
1144  llvm::Value *IsCompleteObject =
1145  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1146 
1147  llvm::BasicBlock *CallVbaseDtorsBB = CGF.createBasicBlock("Dtor.dtor_vbases");
1148  llvm::BasicBlock *SkipVbaseDtorsBB = CGF.createBasicBlock("Dtor.skip_vbases");
1149  CGF.Builder.CreateCondBr(IsCompleteObject,
1150  CallVbaseDtorsBB, SkipVbaseDtorsBB);
1151 
1152  CGF.EmitBlock(CallVbaseDtorsBB);
1153  // CGF will put the base dtor calls in this basic block for us later.
1154 
1155  return SkipVbaseDtorsBB;
1156 }
1157 
1158 void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers(
1159  CodeGenFunction &CGF, const CXXRecordDecl *RD) {
1160  // In most cases, an override for a vbase virtual method can adjust
1161  // the "this" parameter by applying a constant offset.
1162  // However, this is not enough while a constructor or a destructor of some
1163  // class X is being executed if all the following conditions are met:
1164  // - X has virtual bases, (1)
1165  // - X overrides a virtual method M of a vbase Y, (2)
1166  // - X itself is a vbase of the most derived class.
1167  //
1168  // If (1) and (2) are true, the vtorDisp for vbase Y is a hidden member of X
1169  // which holds the extra amount of "this" adjustment we must do when we use
1170  // the X vftables (i.e. during X ctor or dtor).
1171  // Outside the ctors and dtors, the values of vtorDisps are zero.
1172 
1173  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1174  typedef ASTRecordLayout::VBaseOffsetsMapTy VBOffsets;
1175  const VBOffsets &VBaseMap = Layout.getVBaseOffsetsMap();
1176  CGBuilderTy &Builder = CGF.Builder;
1177 
1178  unsigned AS = getThisAddress(CGF).getAddressSpace();
1179  llvm::Value *Int8This = nullptr; // Initialize lazily.
1180 
1181  for (VBOffsets::const_iterator I = VBaseMap.begin(), E = VBaseMap.end();
1182  I != E; ++I) {
1183  if (!I->second.hasVtorDisp())
1184  continue;
1185 
1186  llvm::Value *VBaseOffset =
1187  GetVirtualBaseClassOffset(CGF, getThisAddress(CGF), RD, I->first);
1188  uint64_t ConstantVBaseOffset =
1189  Layout.getVBaseClassOffset(I->first).getQuantity();
1190 
1191  // vtorDisp_for_vbase = vbptr[vbase_idx] - offsetof(RD, vbase).
1192  llvm::Value *VtorDispValue = Builder.CreateSub(
1193  VBaseOffset, llvm::ConstantInt::get(CGM.PtrDiffTy, ConstantVBaseOffset),
1194  "vtordisp.value");
1195  VtorDispValue = Builder.CreateTruncOrBitCast(VtorDispValue, CGF.Int32Ty);
1196 
1197  if (!Int8This)
1198  Int8This = Builder.CreateBitCast(getThisValue(CGF),
1199  CGF.Int8Ty->getPointerTo(AS));
1200  llvm::Value *VtorDispPtr = Builder.CreateInBoundsGEP(Int8This, VBaseOffset);
1201  // vtorDisp is always the 32-bits before the vbase in the class layout.
1202  VtorDispPtr = Builder.CreateConstGEP1_32(VtorDispPtr, -4);
1203  VtorDispPtr = Builder.CreateBitCast(
1204  VtorDispPtr, CGF.Int32Ty->getPointerTo(AS), "vtordisp.ptr");
1205 
1206  Builder.CreateAlignedStore(VtorDispValue, VtorDispPtr,
1208  }
1209 }
1210 
1211 static bool hasDefaultCXXMethodCC(ASTContext &Context,
1212  const CXXMethodDecl *MD) {
1213  CallingConv ExpectedCallingConv = Context.getDefaultCallingConvention(
1214  /*IsVariadic=*/false, /*IsCXXMethod=*/true);
1215  CallingConv ActualCallingConv =
1216  MD->getType()->getAs<FunctionProtoType>()->getCallConv();
1217  return ExpectedCallingConv == ActualCallingConv;
1218 }
1219 
1220 void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
1221  // There's only one constructor type in this ABI.
1222  CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete));
1223 
1224  // Exported default constructors either have a simple call-site where they use
1225  // the typical calling convention and have a single 'this' pointer for an
1226  // argument -or- they get a wrapper function which appropriately thunks to the
1227  // real default constructor. This thunk is the default constructor closure.
1228  if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor())
1229  if (!hasDefaultCXXMethodCC(getContext(), D) || D->getNumParams() != 0) {
1230  llvm::Function *Fn = getAddrOfCXXCtorClosure(D, Ctor_DefaultClosure);
1231  Fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
1232  Fn->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1233  }
1234 }
1235 
1236 void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF,
1237  const CXXRecordDecl *RD) {
1238  Address This = getThisAddress(CGF);
1239  This = CGF.Builder.CreateElementBitCast(This, CGM.Int8Ty, "this.int8");
1240  const ASTContext &Context = getContext();
1241  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
1242 
1243  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
1244  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
1245  const std::unique_ptr<VPtrInfo> &VBT = (*VBGlobals.VBTables)[I];
1246  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
1247  const ASTRecordLayout &SubobjectLayout =
1248  Context.getASTRecordLayout(VBT->IntroducingObject);
1249  CharUnits Offs = VBT->NonVirtualOffset;
1250  Offs += SubobjectLayout.getVBPtrOffset();
1251  if (VBT->getVBaseWithVPtr())
1252  Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
1253  Address VBPtr = CGF.Builder.CreateConstInBoundsByteGEP(This, Offs);
1254  llvm::Value *GVPtr =
1255  CGF.Builder.CreateConstInBoundsGEP2_32(GV->getValueType(), GV, 0, 0);
1256  VBPtr = CGF.Builder.CreateElementBitCast(VBPtr, GVPtr->getType(),
1257  "vbptr." + VBT->ObjectWithVPtr->getName());
1258  CGF.Builder.CreateStore(GVPtr, VBPtr);
1259  }
1260 }
1261 
1263 MicrosoftCXXABI::buildStructorSignature(const CXXMethodDecl *MD, StructorType T,
1264  SmallVectorImpl<CanQualType> &ArgTys) {
1265  AddedStructorArgs Added;
1266  // TODO: 'for base' flag
1267  if (T == StructorType::Deleting) {
1268  // The scalar deleting destructor takes an implicit int parameter.
1269  ArgTys.push_back(getContext().IntTy);
1270  ++Added.Suffix;
1271  }
1272  auto *CD = dyn_cast<CXXConstructorDecl>(MD);
1273  if (!CD)
1274  return Added;
1275 
1276  // All parameters are already in place except is_most_derived, which goes
1277  // after 'this' if it's variadic and last if it's not.
1278 
1279  const CXXRecordDecl *Class = CD->getParent();
1280  const FunctionProtoType *FPT = CD->getType()->castAs<FunctionProtoType>();
1281  if (Class->getNumVBases()) {
1282  if (FPT->isVariadic()) {
1283  ArgTys.insert(ArgTys.begin() + 1, getContext().IntTy);
1284  ++Added.Prefix;
1285  } else {
1286  ArgTys.push_back(getContext().IntTy);
1287  ++Added.Suffix;
1288  }
1289  }
1290 
1291  return Added;
1292 }
1293 
1294 void MicrosoftCXXABI::EmitCXXDestructors(const CXXDestructorDecl *D) {
1295  // The TU defining a dtor is only guaranteed to emit a base destructor. All
1296  // other destructor variants are delegating thunks.
1297  CGM.EmitGlobal(GlobalDecl(D, Dtor_Base));
1298 }
1299 
1300 CharUnits
1301 MicrosoftCXXABI::getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
1302  GD = GD.getCanonicalDecl();
1303  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1304 
1305  GlobalDecl LookupGD = GD;
1306  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1307  // Complete destructors take a pointer to the complete object as a
1308  // parameter, thus don't need this adjustment.
1309  if (GD.getDtorType() == Dtor_Complete)
1310  return CharUnits();
1311 
1312  // There's no Dtor_Base in vftable but it shares the this adjustment with
1313  // the deleting one, so look it up instead.
1314  LookupGD = GlobalDecl(DD, Dtor_Deleting);
1315  }
1316 
1318  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
1319  CharUnits Adjustment = ML.VFPtrOffset;
1320 
1321  // Normal virtual instance methods need to adjust from the vfptr that first
1322  // defined the virtual method to the virtual base subobject, but destructors
1323  // do not. The vector deleting destructor thunk applies this adjustment for
1324  // us if necessary.
1325  if (isa<CXXDestructorDecl>(MD))
1326  Adjustment = CharUnits::Zero();
1327 
1328  if (ML.VBase) {
1329  const ASTRecordLayout &DerivedLayout =
1330  getContext().getASTRecordLayout(MD->getParent());
1331  Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase);
1332  }
1333 
1334  return Adjustment;
1335 }
1336 
1337 Address MicrosoftCXXABI::adjustThisArgumentForVirtualFunctionCall(
1338  CodeGenFunction &CGF, GlobalDecl GD, Address This,
1339  bool VirtualCall) {
1340  if (!VirtualCall) {
1341  // If the call of a virtual function is not virtual, we just have to
1342  // compensate for the adjustment the virtual function does in its prologue.
1343  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD);
1344  if (Adjustment.isZero())
1345  return This;
1346 
1347  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
1348  assert(Adjustment.isPositive());
1349  return CGF.Builder.CreateConstByteGEP(This, Adjustment);
1350  }
1351 
1352  GD = GD.getCanonicalDecl();
1353  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1354 
1355  GlobalDecl LookupGD = GD;
1356  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1357  // Complete dtors take a pointer to the complete object,
1358  // thus don't need adjustment.
1359  if (GD.getDtorType() == Dtor_Complete)
1360  return This;
1361 
1362  // There's only Dtor_Deleting in vftable but it shares the this adjustment
1363  // with the base one, so look up the deleting one instead.
1364  LookupGD = GlobalDecl(DD, Dtor_Deleting);
1365  }
1367  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
1368 
1369  CharUnits StaticOffset = ML.VFPtrOffset;
1370 
1371  // Base destructors expect 'this' to point to the beginning of the base
1372  // subobject, not the first vfptr that happens to contain the virtual dtor.
1373  // However, we still need to apply the virtual base adjustment.
1374  if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
1375  StaticOffset = CharUnits::Zero();
1376 
1377  Address Result = This;
1378  if (ML.VBase) {
1379  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1380 
1381  const CXXRecordDecl *Derived = MD->getParent();
1382  const CXXRecordDecl *VBase = ML.VBase;
1383  llvm::Value *VBaseOffset =
1384  GetVirtualBaseClassOffset(CGF, Result, Derived, VBase);
1385  llvm::Value *VBasePtr =
1386  CGF.Builder.CreateInBoundsGEP(Result.getPointer(), VBaseOffset);
1387  CharUnits VBaseAlign =
1388  CGF.CGM.getVBaseAlignment(Result.getAlignment(), Derived, VBase);
1389  Result = Address(VBasePtr, VBaseAlign);
1390  }
1391  if (!StaticOffset.isZero()) {
1392  assert(StaticOffset.isPositive());
1393  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1394  if (ML.VBase) {
1395  // Non-virtual adjustment might result in a pointer outside the allocated
1396  // object, e.g. if the final overrider class is laid out after the virtual
1397  // base that declares a method in the most derived class.
1398  // FIXME: Update the code that emits this adjustment in thunks prologues.
1399  Result = CGF.Builder.CreateConstByteGEP(Result, StaticOffset);
1400  } else {
1401  Result = CGF.Builder.CreateConstInBoundsByteGEP(Result, StaticOffset);
1402  }
1403  }
1404  return Result;
1405 }
1406 
1407 void MicrosoftCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
1408  QualType &ResTy,
1409  FunctionArgList &Params) {
1410  ASTContext &Context = getContext();
1411  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1412  assert(isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD));
1413  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1414  auto *IsMostDerived = ImplicitParamDecl::Create(
1415  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1416  &Context.Idents.get("is_most_derived"), Context.IntTy,
1418  // The 'most_derived' parameter goes second if the ctor is variadic and last
1419  // if it's not. Dtors can't be variadic.
1420  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
1421  if (FPT->isVariadic())
1422  Params.insert(Params.begin() + 1, IsMostDerived);
1423  else
1424  Params.push_back(IsMostDerived);
1425  getStructorImplicitParamDecl(CGF) = IsMostDerived;
1426  } else if (isDeletingDtor(CGF.CurGD)) {
1427  auto *ShouldDelete = ImplicitParamDecl::Create(
1428  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1429  &Context.Idents.get("should_call_delete"), Context.IntTy,
1431  Params.push_back(ShouldDelete);
1432  getStructorImplicitParamDecl(CGF) = ShouldDelete;
1433  }
1434 }
1435 
1436 llvm::Value *MicrosoftCXXABI::adjustThisParameterInVirtualFunctionPrologue(
1437  CodeGenFunction &CGF, GlobalDecl GD, llvm::Value *This) {
1438  // In this ABI, every virtual function takes a pointer to one of the
1439  // subobjects that first defines it as the 'this' parameter, rather than a
1440  // pointer to the final overrider subobject. Thus, we need to adjust it back
1441  // to the final overrider subobject before use.
1442  // See comments in the MicrosoftVFTableContext implementation for the details.
1443  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD);
1444  if (Adjustment.isZero())
1445  return This;
1446 
1447  unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
1448  llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS),
1449  *thisTy = This->getType();
1450 
1451  This = CGF.Builder.CreateBitCast(This, charPtrTy);
1452  assert(Adjustment.isPositive());
1453  This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This,
1454  -Adjustment.getQuantity());
1455  return CGF.Builder.CreateBitCast(This, thisTy);
1456 }
1457 
1458 void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
1459  // Naked functions have no prolog.
1460  if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
1461  return;
1462 
1463  EmitThisParam(CGF);
1464 
1465  /// If this is a function that the ABI specifies returns 'this', initialize
1466  /// the return slot to 'this' at the start of the function.
1467  ///
1468  /// Unlike the setting of return types, this is done within the ABI
1469  /// implementation instead of by clients of CGCXXABI because:
1470  /// 1) getThisValue is currently protected
1471  /// 2) in theory, an ABI could implement 'this' returns some other way;
1472  /// HasThisReturn only specifies a contract, not the implementation
1473  if (HasThisReturn(CGF.CurGD))
1474  CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
1475  else if (hasMostDerivedReturn(CGF.CurGD))
1476  CGF.Builder.CreateStore(CGF.EmitCastToVoidPtr(getThisValue(CGF)),
1477  CGF.ReturnValue);
1478 
1479  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1480  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1481  assert(getStructorImplicitParamDecl(CGF) &&
1482  "no implicit parameter for a constructor with virtual bases?");
1483  getStructorImplicitParamValue(CGF)
1484  = CGF.Builder.CreateLoad(
1485  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1486  "is_most_derived");
1487  }
1488 
1489  if (isDeletingDtor(CGF.CurGD)) {
1490  assert(getStructorImplicitParamDecl(CGF) &&
1491  "no implicit parameter for a deleting destructor?");
1492  getStructorImplicitParamValue(CGF)
1493  = CGF.Builder.CreateLoad(
1494  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1495  "should_call_delete");
1496  }
1497 }
1498 
1499 CGCXXABI::AddedStructorArgs MicrosoftCXXABI::addImplicitConstructorArgs(
1501  bool ForVirtualBase, bool Delegating, CallArgList &Args) {
1502  assert(Type == Ctor_Complete || Type == Ctor_Base);
1503 
1504  // Check if we need a 'most_derived' parameter.
1505  if (!D->getParent()->getNumVBases())
1506  return AddedStructorArgs{};
1507 
1508  // Add the 'most_derived' argument second if we are variadic or last if not.
1509  const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
1510  llvm::Value *MostDerivedArg;
1511  if (Delegating) {
1512  MostDerivedArg = getStructorImplicitParamValue(CGF);
1513  } else {
1514  MostDerivedArg = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete);
1515  }
1516  RValue RV = RValue::get(MostDerivedArg);
1517  if (FPT->isVariadic()) {
1518  Args.insert(Args.begin() + 1,
1519  CallArg(RV, getContext().IntTy, /*needscopy=*/false));
1520  return AddedStructorArgs::prefix(1);
1521  }
1522  Args.add(RV, getContext().IntTy);
1523  return AddedStructorArgs::suffix(1);
1524 }
1525 
1526 void MicrosoftCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
1527  const CXXDestructorDecl *DD,
1528  CXXDtorType Type, bool ForVirtualBase,
1529  bool Delegating, Address This) {
1530  CGCallee Callee = CGCallee::forDirect(
1531  CGM.getAddrOfCXXStructor(DD, getFromDtorType(Type)),
1532  DD);
1533 
1534  if (DD->isVirtual()) {
1535  assert(Type != CXXDtorType::Dtor_Deleting &&
1536  "The deleting destructor should only be called via a virtual call");
1537  This = adjustThisArgumentForVirtualFunctionCall(CGF, GlobalDecl(DD, Type),
1538  This, false);
1539  }
1540 
1541  llvm::BasicBlock *BaseDtorEndBB = nullptr;
1542  if (ForVirtualBase && isa<CXXConstructorDecl>(CGF.CurCodeDecl)) {
1543  BaseDtorEndBB = EmitDtorCompleteObjectHandler(CGF);
1544  }
1545 
1546  CGF.EmitCXXDestructorCall(DD, Callee, This.getPointer(),
1547  /*ImplicitParam=*/nullptr,
1548  /*ImplicitParamTy=*/QualType(), nullptr,
1549  getFromDtorType(Type));
1550  if (BaseDtorEndBB) {
1551  // Complete object handler should continue to be the remaining
1552  CGF.Builder.CreateBr(BaseDtorEndBB);
1553  CGF.EmitBlock(BaseDtorEndBB);
1554  }
1555 }
1556 
1557 void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
1558  const CXXRecordDecl *RD,
1559  llvm::GlobalVariable *VTable) {
1560  if (!CGM.getCodeGenOpts().LTOUnit)
1561  return;
1562 
1563  // The location of the first virtual function pointer in the virtual table,
1564  // aka the "address point" on Itanium. This is at offset 0 if RTTI is
1565  // disabled, or sizeof(void*) if RTTI is enabled.
1566  CharUnits AddressPoint =
1567  getContext().getLangOpts().RTTIData
1568  ? getContext().toCharUnitsFromBits(
1569  getContext().getTargetInfo().getPointerWidth(0))
1570  : CharUnits::Zero();
1571 
1572  if (Info.PathToIntroducingObject.empty()) {
1573  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1574  return;
1575  }
1576 
1577  // Add a bitset entry for the least derived base belonging to this vftable.
1578  CGM.AddVTableTypeMetadata(VTable, AddressPoint,
1579  Info.PathToIntroducingObject.back());
1580 
1581  // Add a bitset entry for each derived class that is laid out at the same
1582  // offset as the least derived base.
1583  for (unsigned I = Info.PathToIntroducingObject.size() - 1; I != 0; --I) {
1584  const CXXRecordDecl *DerivedRD = Info.PathToIntroducingObject[I - 1];
1585  const CXXRecordDecl *BaseRD = Info.PathToIntroducingObject[I];
1586 
1587  const ASTRecordLayout &Layout =
1588  getContext().getASTRecordLayout(DerivedRD);
1589  CharUnits Offset;
1590  auto VBI = Layout.getVBaseOffsetsMap().find(BaseRD);
1591  if (VBI == Layout.getVBaseOffsetsMap().end())
1592  Offset = Layout.getBaseClassOffset(BaseRD);
1593  else
1594  Offset = VBI->second.VBaseOffset;
1595  if (!Offset.isZero())
1596  return;
1597  CGM.AddVTableTypeMetadata(VTable, AddressPoint, DerivedRD);
1598  }
1599 
1600  // Finally do the same for the most derived class.
1601  if (Info.FullOffsetInMDC.isZero())
1602  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1603 }
1604 
1605 void MicrosoftCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
1606  const CXXRecordDecl *RD) {
1607  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1608  const VPtrInfoVector &VFPtrs = VFTContext.getVFPtrOffsets(RD);
1609 
1610  for (const std::unique_ptr<VPtrInfo>& Info : VFPtrs) {
1611  llvm::GlobalVariable *VTable = getAddrOfVTable(RD, Info->FullOffsetInMDC);
1612  if (VTable->hasInitializer())
1613  continue;
1614 
1615  const VTableLayout &VTLayout =
1616  VFTContext.getVFTableLayout(RD, Info->FullOffsetInMDC);
1617 
1618  llvm::Constant *RTTI = nullptr;
1619  if (any_of(VTLayout.vtable_components(),
1620  [](const VTableComponent &VTC) { return VTC.isRTTIKind(); }))
1621  RTTI = getMSCompleteObjectLocator(RD, *Info);
1622 
1624  auto Components = Builder.beginStruct();
1625  CGVT.createVTableInitializer(Components, VTLayout, RTTI);
1626  Components.finishAndSetAsInitializer(VTable);
1627 
1628  emitVTableTypeMetadata(*Info, RD, VTable);
1629  }
1630 }
1631 
1632 bool MicrosoftCXXABI::isVirtualOffsetNeededForVTableField(
1634  return Vptr.NearestVBase != nullptr;
1635 }
1636 
1637 llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor(
1638  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
1639  const CXXRecordDecl *NearestVBase) {
1640  llvm::Constant *VTableAddressPoint = getVTableAddressPoint(Base, VTableClass);
1641  if (!VTableAddressPoint) {
1642  assert(Base.getBase()->getNumVBases() &&
1643  !getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr());
1644  }
1645  return VTableAddressPoint;
1646 }
1647 
1649  const CXXRecordDecl *RD, const VPtrInfo &VFPtr,
1650  SmallString<256> &Name) {
1651  llvm::raw_svector_ostream Out(Name);
1652  MangleContext.mangleCXXVFTable(RD, VFPtr.MangledPath, Out);
1653 }
1654 
1655 llvm::Constant *
1656 MicrosoftCXXABI::getVTableAddressPoint(BaseSubobject Base,
1657  const CXXRecordDecl *VTableClass) {
1658  (void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
1659  VFTableIdTy ID(VTableClass, Base.getBaseOffset());
1660  return VFTablesMap[ID];
1661 }
1662 
1663 llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
1664  BaseSubobject Base, const CXXRecordDecl *VTableClass) {
1665  llvm::Constant *VFTable = getVTableAddressPoint(Base, VTableClass);
1666  assert(VFTable && "Couldn't find a vftable for the given base?");
1667  return VFTable;
1668 }
1669 
1670 llvm::GlobalVariable *MicrosoftCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
1671  CharUnits VPtrOffset) {
1672  // getAddrOfVTable may return 0 if asked to get an address of a vtable which
1673  // shouldn't be used in the given record type. We want to cache this result in
1674  // VFTablesMap, thus a simple zero check is not sufficient.
1675 
1676  VFTableIdTy ID(RD, VPtrOffset);
1677  VTablesMapTy::iterator I;
1678  bool Inserted;
1679  std::tie(I, Inserted) = VTablesMap.insert(std::make_pair(ID, nullptr));
1680  if (!Inserted)
1681  return I->second;
1682 
1683  llvm::GlobalVariable *&VTable = I->second;
1684 
1685  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
1686  const VPtrInfoVector &VFPtrs = VTContext.getVFPtrOffsets(RD);
1687 
1688  if (DeferredVFTables.insert(RD).second) {
1689  // We haven't processed this record type before.
1690  // Queue up this vtable for possible deferred emission.
1691  CGM.addDeferredVTable(RD);
1692 
1693 #ifndef NDEBUG
1694  // Create all the vftables at once in order to make sure each vftable has
1695  // a unique mangled name.
1696  llvm::StringSet<> ObservedMangledNames;
1697  for (size_t J = 0, F = VFPtrs.size(); J != F; ++J) {
1699  mangleVFTableName(getMangleContext(), RD, *VFPtrs[J], Name);
1700  if (!ObservedMangledNames.insert(Name.str()).second)
1701  llvm_unreachable("Already saw this mangling before?");
1702  }
1703 #endif
1704  }
1705 
1706  const std::unique_ptr<VPtrInfo> *VFPtrI = std::find_if(
1707  VFPtrs.begin(), VFPtrs.end(), [&](const std::unique_ptr<VPtrInfo>& VPI) {
1708  return VPI->FullOffsetInMDC == VPtrOffset;
1709  });
1710  if (VFPtrI == VFPtrs.end()) {
1711  VFTablesMap[ID] = nullptr;
1712  return nullptr;
1713  }
1714  const std::unique_ptr<VPtrInfo> &VFPtr = *VFPtrI;
1715 
1716  SmallString<256> VFTableName;
1717  mangleVFTableName(getMangleContext(), RD, *VFPtr, VFTableName);
1718 
1719  // Classes marked __declspec(dllimport) need vftables generated on the
1720  // import-side in order to support features like constexpr. No other
1721  // translation unit relies on the emission of the local vftable, translation
1722  // units are expected to generate them as needed.
1723  //
1724  // Because of this unique behavior, we maintain this logic here instead of
1725  // getVTableLinkage.
1726  llvm::GlobalValue::LinkageTypes VFTableLinkage =
1727  RD->hasAttr<DLLImportAttr>() ? llvm::GlobalValue::LinkOnceODRLinkage
1728  : CGM.getVTableLinkage(RD);
1729  bool VFTableComesFromAnotherTU =
1730  llvm::GlobalValue::isAvailableExternallyLinkage(VFTableLinkage) ||
1731  llvm::GlobalValue::isExternalLinkage(VFTableLinkage);
1732  bool VTableAliasIsRequred =
1733  !VFTableComesFromAnotherTU && getContext().getLangOpts().RTTIData;
1734 
1735  if (llvm::GlobalValue *VFTable =
1736  CGM.getModule().getNamedGlobal(VFTableName)) {
1737  VFTablesMap[ID] = VFTable;
1738  VTable = VTableAliasIsRequred
1739  ? cast<llvm::GlobalVariable>(
1740  cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
1741  : cast<llvm::GlobalVariable>(VFTable);
1742  return VTable;
1743  }
1744 
1745  const VTableLayout &VTLayout =
1746  VTContext.getVFTableLayout(RD, VFPtr->FullOffsetInMDC);
1747  llvm::GlobalValue::LinkageTypes VTableLinkage =
1748  VTableAliasIsRequred ? llvm::GlobalValue::PrivateLinkage : VFTableLinkage;
1749 
1750  StringRef VTableName = VTableAliasIsRequred ? StringRef() : VFTableName.str();
1751 
1752  llvm::Type *VTableType = CGM.getVTables().getVTableType(VTLayout);
1753 
1754  // Create a backing variable for the contents of VTable. The VTable may
1755  // or may not include space for a pointer to RTTI data.
1756  llvm::GlobalValue *VFTable;
1757  VTable = new llvm::GlobalVariable(CGM.getModule(), VTableType,
1758  /*isConstant=*/true, VTableLinkage,
1759  /*Initializer=*/nullptr, VTableName);
1760  VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1761 
1762  llvm::Comdat *C = nullptr;
1763  if (!VFTableComesFromAnotherTU &&
1764  (llvm::GlobalValue::isWeakForLinker(VFTableLinkage) ||
1765  (llvm::GlobalValue::isLocalLinkage(VFTableLinkage) &&
1766  VTableAliasIsRequred)))
1767  C = CGM.getModule().getOrInsertComdat(VFTableName.str());
1768 
1769  // Only insert a pointer into the VFTable for RTTI data if we are not
1770  // importing it. We never reference the RTTI data directly so there is no
1771  // need to make room for it.
1772  if (VTableAliasIsRequred) {
1773  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.Int32Ty, 0),
1774  llvm::ConstantInt::get(CGM.Int32Ty, 0),
1775  llvm::ConstantInt::get(CGM.Int32Ty, 1)};
1776  // Create a GEP which points just after the first entry in the VFTable,
1777  // this should be the location of the first virtual method.
1778  llvm::Constant *VTableGEP = llvm::ConstantExpr::getInBoundsGetElementPtr(
1779  VTable->getValueType(), VTable, GEPIndices);
1780  if (llvm::GlobalValue::isWeakForLinker(VFTableLinkage)) {
1781  VFTableLinkage = llvm::GlobalValue::ExternalLinkage;
1782  if (C)
1783  C->setSelectionKind(llvm::Comdat::Largest);
1784  }
1785  VFTable = llvm::GlobalAlias::create(CGM.Int8PtrTy,
1786  /*AddressSpace=*/0, VFTableLinkage,
1787  VFTableName.str(), VTableGEP,
1788  &CGM.getModule());
1789  VFTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1790  } else {
1791  // We don't need a GlobalAlias to be a symbol for the VTable if we won't
1792  // be referencing any RTTI data.
1793  // The GlobalVariable will end up being an appropriate definition of the
1794  // VFTable.
1795  VFTable = VTable;
1796  }
1797  if (C)
1798  VTable->setComdat(C);
1799 
1800  if (RD->hasAttr<DLLExportAttr>())
1801  VFTable->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1802 
1803  VFTablesMap[ID] = VFTable;
1804  return VTable;
1805 }
1806 
1807 CGCallee MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
1808  GlobalDecl GD,
1809  Address This,
1810  llvm::Type *Ty,
1811  SourceLocation Loc) {
1812  GD = GD.getCanonicalDecl();
1813  CGBuilderTy &Builder = CGF.Builder;
1814 
1815  Ty = Ty->getPointerTo()->getPointerTo();
1816  Address VPtr =
1817  adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1818 
1819  auto *MethodDecl = cast<CXXMethodDecl>(GD.getDecl());
1820  llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty, MethodDecl->getParent());
1821 
1822  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1824  VFTContext.getMethodVFTableLocation(GD);
1825 
1826  // Compute the identity of the most derived class whose virtual table is
1827  // located at the MethodVFTableLocation ML.
1828  auto getObjectWithVPtr = [&] {
1829  return llvm::find_if(VFTContext.getVFPtrOffsets(
1830  ML.VBase ? ML.VBase : MethodDecl->getParent()),
1831  [&](const std::unique_ptr<VPtrInfo> &Info) {
1832  return Info->FullOffsetInMDC == ML.VFPtrOffset;
1833  })
1834  ->get()
1835  ->ObjectWithVPtr;
1836  };
1837 
1838  llvm::Value *VFunc;
1839  if (CGF.ShouldEmitVTableTypeCheckedLoad(MethodDecl->getParent())) {
1840  VFunc = CGF.EmitVTableTypeCheckedLoad(
1841  getObjectWithVPtr(), VTable,
1842  ML.Index * CGM.getContext().getTargetInfo().getPointerWidth(0) / 8);
1843  } else {
1844  if (CGM.getCodeGenOpts().PrepareForLTO)
1845  CGF.EmitTypeMetadataCodeForVCall(getObjectWithVPtr(), VTable, Loc);
1846 
1847  llvm::Value *VFuncPtr =
1848  Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
1849  VFunc = Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
1850  }
1851 
1852  CGCallee Callee(MethodDecl, VFunc);
1853  return Callee;
1854 }
1855 
1856 llvm::Value *MicrosoftCXXABI::EmitVirtualDestructorCall(
1857  CodeGenFunction &CGF, const CXXDestructorDecl *Dtor, CXXDtorType DtorType,
1858  Address This, const CXXMemberCallExpr *CE) {
1859  assert(CE == nullptr || CE->arg_begin() == CE->arg_end());
1860  assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
1861 
1862  // We have only one destructor in the vftable but can get both behaviors
1863  // by passing an implicit int parameter.
1864  GlobalDecl GD(Dtor, Dtor_Deleting);
1865  const CGFunctionInfo *FInfo = &CGM.getTypes().arrangeCXXStructorDeclaration(
1866  Dtor, StructorType::Deleting);
1867  llvm::Type *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
1868  CGCallee Callee = getVirtualFunctionPointer(
1869  CGF, GD, This, Ty, CE ? CE->getLocStart() : SourceLocation());
1870 
1871  ASTContext &Context = getContext();
1872  llvm::Value *ImplicitParam = llvm::ConstantInt::get(
1873  llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()),
1874  DtorType == Dtor_Deleting);
1875 
1876  This = adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1877  RValue RV =
1878  CGF.EmitCXXDestructorCall(Dtor, Callee, This.getPointer(), ImplicitParam,
1879  Context.IntTy, CE, StructorType::Deleting);
1880  return RV.getScalarVal();
1881 }
1882 
1883 const VBTableGlobals &
1884 MicrosoftCXXABI::enumerateVBTables(const CXXRecordDecl *RD) {
1885  // At this layer, we can key the cache off of a single class, which is much
1886  // easier than caching each vbtable individually.
1887  llvm::DenseMap<const CXXRecordDecl*, VBTableGlobals>::iterator Entry;
1888  bool Added;
1889  std::tie(Entry, Added) =
1890  VBTablesMap.insert(std::make_pair(RD, VBTableGlobals()));
1891  VBTableGlobals &VBGlobals = Entry->second;
1892  if (!Added)
1893  return VBGlobals;
1894 
1895  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
1896  VBGlobals.VBTables = &Context.enumerateVBTables(RD);
1897 
1898  // Cache the globals for all vbtables so we don't have to recompute the
1899  // mangled names.
1900  llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
1901  for (VPtrInfoVector::const_iterator I = VBGlobals.VBTables->begin(),
1902  E = VBGlobals.VBTables->end();
1903  I != E; ++I) {
1904  VBGlobals.Globals.push_back(getAddrOfVBTable(**I, RD, Linkage));
1905  }
1906 
1907  return VBGlobals;
1908 }
1909 
1910 llvm::Function *MicrosoftCXXABI::EmitVirtualMemPtrThunk(
1911  const CXXMethodDecl *MD,
1913  assert(!isa<CXXConstructorDecl>(MD) && !isa<CXXDestructorDecl>(MD) &&
1914  "can't form pointers to ctors or virtual dtors");
1915 
1916  // Calculate the mangled name.
1917  SmallString<256> ThunkName;
1918  llvm::raw_svector_ostream Out(ThunkName);
1919  getMangleContext().mangleVirtualMemPtrThunk(MD, Out);
1920 
1921  // If the thunk has been generated previously, just return it.
1922  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
1923  return cast<llvm::Function>(GV);
1924 
1925  // Create the llvm::Function.
1926  const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeMSMemberPointerThunk(MD);
1927  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
1928  llvm::Function *ThunkFn =
1930  ThunkName.str(), &CGM.getModule());
1931  assert(ThunkFn->getName() == ThunkName && "name was uniqued!");
1932 
1933  ThunkFn->setLinkage(MD->isExternallyVisible()
1934  ? llvm::GlobalValue::LinkOnceODRLinkage
1936  if (MD->isExternallyVisible())
1937  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
1938 
1939  CGM.SetLLVMFunctionAttributes(MD, FnInfo, ThunkFn);
1940  CGM.SetLLVMFunctionAttributesForDefinition(MD, ThunkFn);
1941 
1942  // Add the "thunk" attribute so that LLVM knows that the return type is
1943  // meaningless. These thunks can be used to call functions with differing
1944  // return types, and the caller is required to cast the prototype
1945  // appropriately to extract the correct value.
1946  ThunkFn->addFnAttr("thunk");
1947 
1948  // These thunks can be compared, so they are not unnamed.
1949  ThunkFn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
1950 
1951  // Start codegen.
1952  CodeGenFunction CGF(CGM);
1953  CGF.CurGD = GlobalDecl(MD);
1954  CGF.CurFuncIsThunk = true;
1955 
1956  // Build FunctionArgs, but only include the implicit 'this' parameter
1957  // declaration.
1958  FunctionArgList FunctionArgs;
1959  buildThisParam(CGF, FunctionArgs);
1960 
1961  // Start defining the function.
1962  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
1963  FunctionArgs, MD->getLocation(), SourceLocation());
1964  EmitThisParam(CGF);
1965 
1966  // Load the vfptr and then callee from the vftable. The callee should have
1967  // adjusted 'this' so that the vfptr is at offset zero.
1968  llvm::Value *VTable = CGF.GetVTablePtr(
1969  getThisAddress(CGF), ThunkTy->getPointerTo()->getPointerTo(), MD->getParent());
1970 
1971  llvm::Value *VFuncPtr =
1972  CGF.Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
1973  llvm::Value *Callee =
1974  CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
1975 
1976  CGF.EmitMustTailThunk(MD, getThisValue(CGF), Callee);
1977 
1978  return ThunkFn;
1979 }
1980 
1981 void MicrosoftCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
1982  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
1983  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
1984  const std::unique_ptr<VPtrInfo>& VBT = (*VBGlobals.VBTables)[I];
1985  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
1986  if (GV->isDeclaration())
1987  emitVBTableDefinition(*VBT, RD, GV);
1988  }
1989 }
1990 
1991 llvm::GlobalVariable *
1992 MicrosoftCXXABI::getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
1993  llvm::GlobalVariable::LinkageTypes Linkage) {
1994  SmallString<256> OutName;
1995  llvm::raw_svector_ostream Out(OutName);
1996  getMangleContext().mangleCXXVBTable(RD, VBT.MangledPath, Out);
1997  StringRef Name = OutName.str();
1998 
1999  llvm::ArrayType *VBTableType =
2000  llvm::ArrayType::get(CGM.IntTy, 1 + VBT.ObjectWithVPtr->getNumVBases());
2001 
2002  assert(!CGM.getModule().getNamedGlobal(Name) &&
2003  "vbtable with this name already exists: mangling bug?");
2004  llvm::GlobalVariable *GV =
2005  CGM.CreateOrReplaceCXXRuntimeVariable(Name, VBTableType, Linkage);
2006  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2007 
2008  if (RD->hasAttr<DLLImportAttr>())
2009  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2010  else if (RD->hasAttr<DLLExportAttr>())
2011  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2012 
2013  if (!GV->hasExternalLinkage())
2014  emitVBTableDefinition(VBT, RD, GV);
2015 
2016  return GV;
2017 }
2018 
2019 void MicrosoftCXXABI::emitVBTableDefinition(const VPtrInfo &VBT,
2020  const CXXRecordDecl *RD,
2021  llvm::GlobalVariable *GV) const {
2022  const CXXRecordDecl *ObjectWithVPtr = VBT.ObjectWithVPtr;
2023 
2024  assert(RD->getNumVBases() && ObjectWithVPtr->getNumVBases() &&
2025  "should only emit vbtables for classes with vbtables");
2026 
2027  const ASTRecordLayout &BaseLayout =
2028  getContext().getASTRecordLayout(VBT.IntroducingObject);
2029  const ASTRecordLayout &DerivedLayout = getContext().getASTRecordLayout(RD);
2030 
2031  SmallVector<llvm::Constant *, 4> Offsets(1 + ObjectWithVPtr->getNumVBases(),
2032  nullptr);
2033 
2034  // The offset from ObjectWithVPtr's vbptr to itself always leads.
2035  CharUnits VBPtrOffset = BaseLayout.getVBPtrOffset();
2036  Offsets[0] = llvm::ConstantInt::get(CGM.IntTy, -VBPtrOffset.getQuantity());
2037 
2038  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
2039  for (const auto &I : ObjectWithVPtr->vbases()) {
2040  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
2041  CharUnits Offset = DerivedLayout.getVBaseClassOffset(VBase);
2042  assert(!Offset.isNegative());
2043 
2044  // Make it relative to the subobject vbptr.
2045  CharUnits CompleteVBPtrOffset = VBT.NonVirtualOffset + VBPtrOffset;
2046  if (VBT.getVBaseWithVPtr())
2047  CompleteVBPtrOffset +=
2048  DerivedLayout.getVBaseClassOffset(VBT.getVBaseWithVPtr());
2049  Offset -= CompleteVBPtrOffset;
2050 
2051  unsigned VBIndex = Context.getVBTableIndex(ObjectWithVPtr, VBase);
2052  assert(Offsets[VBIndex] == nullptr && "The same vbindex seen twice?");
2053  Offsets[VBIndex] = llvm::ConstantInt::get(CGM.IntTy, Offset.getQuantity());
2054  }
2055 
2056  assert(Offsets.size() ==
2057  cast<llvm::ArrayType>(cast<llvm::PointerType>(GV->getType())
2058  ->getElementType())->getNumElements());
2059  llvm::ArrayType *VBTableType =
2060  llvm::ArrayType::get(CGM.IntTy, Offsets.size());
2061  llvm::Constant *Init = llvm::ConstantArray::get(VBTableType, Offsets);
2062  GV->setInitializer(Init);
2063 
2064  if (RD->hasAttr<DLLImportAttr>())
2065  GV->setLinkage(llvm::GlobalVariable::AvailableExternallyLinkage);
2066 }
2067 
2068 llvm::Value *MicrosoftCXXABI::performThisAdjustment(CodeGenFunction &CGF,
2069  Address This,
2070  const ThisAdjustment &TA) {
2071  if (TA.isEmpty())
2072  return This.getPointer();
2073 
2074  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
2075 
2076  llvm::Value *V;
2077  if (TA.Virtual.isEmpty()) {
2078  V = This.getPointer();
2079  } else {
2080  assert(TA.Virtual.Microsoft.VtordispOffset < 0);
2081  // Adjust the this argument based on the vtordisp value.
2082  Address VtorDispPtr =
2085  VtorDispPtr = CGF.Builder.CreateElementBitCast(VtorDispPtr, CGF.Int32Ty);
2086  llvm::Value *VtorDisp = CGF.Builder.CreateLoad(VtorDispPtr, "vtordisp");
2087  V = CGF.Builder.CreateGEP(This.getPointer(),
2088  CGF.Builder.CreateNeg(VtorDisp));
2089 
2090  // Unfortunately, having applied the vtordisp means that we no
2091  // longer really have a known alignment for the vbptr step.
2092  // We'll assume the vbptr is pointer-aligned.
2093 
2094  if (TA.Virtual.Microsoft.VBPtrOffset) {
2095  // If the final overrider is defined in a virtual base other than the one
2096  // that holds the vfptr, we have to use a vtordispex thunk which looks up
2097  // the vbtable of the derived class.
2098  assert(TA.Virtual.Microsoft.VBPtrOffset > 0);
2099  assert(TA.Virtual.Microsoft.VBOffsetOffset >= 0);
2100  llvm::Value *VBPtr;
2101  llvm::Value *VBaseOffset =
2102  GetVBaseOffsetFromVBPtr(CGF, Address(V, CGF.getPointerAlign()),
2104  TA.Virtual.Microsoft.VBOffsetOffset, &VBPtr);
2105  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2106  }
2107  }
2108 
2109  if (TA.NonVirtual) {
2110  // Non-virtual adjustment might result in a pointer outside the allocated
2111  // object, e.g. if the final overrider class is laid out after the virtual
2112  // base that declares a method in the most derived class.
2113  V = CGF.Builder.CreateConstGEP1_32(V, TA.NonVirtual);
2114  }
2115 
2116  // Don't need to bitcast back, the call CodeGen will handle this.
2117  return V;
2118 }
2119 
2120 llvm::Value *
2121 MicrosoftCXXABI::performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
2122  const ReturnAdjustment &RA) {
2123  if (RA.isEmpty())
2124  return Ret.getPointer();
2125 
2126  auto OrigTy = Ret.getType();
2127  Ret = CGF.Builder.CreateElementBitCast(Ret, CGF.Int8Ty);
2128 
2129  llvm::Value *V = Ret.getPointer();
2130  if (RA.Virtual.Microsoft.VBIndex) {
2131  assert(RA.Virtual.Microsoft.VBIndex > 0);
2132  int32_t IntSize = CGF.getIntSize().getQuantity();
2133  llvm::Value *VBPtr;
2134  llvm::Value *VBaseOffset =
2135  GetVBaseOffsetFromVBPtr(CGF, Ret, RA.Virtual.Microsoft.VBPtrOffset,
2136  IntSize * RA.Virtual.Microsoft.VBIndex, &VBPtr);
2137  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2138  }
2139 
2140  if (RA.NonVirtual)
2141  V = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, V, RA.NonVirtual);
2142 
2143  // Cast back to the original type.
2144  return CGF.Builder.CreateBitCast(V, OrigTy);
2145 }
2146 
2147 bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
2148  QualType elementType) {
2149  // Microsoft seems to completely ignore the possibility of a
2150  // two-argument usual deallocation function.
2151  return elementType.isDestructedType();
2152 }
2153 
2154 bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) {
2155  // Microsoft seems to completely ignore the possibility of a
2156  // two-argument usual deallocation function.
2157  return expr->getAllocatedType().isDestructedType();
2158 }
2159 
2160 CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) {
2161  // The array cookie is always a size_t; we then pad that out to the
2162  // alignment of the element type.
2163  ASTContext &Ctx = getContext();
2164  return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
2165  Ctx.getTypeAlignInChars(type));
2166 }
2167 
2168 llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
2169  Address allocPtr,
2170  CharUnits cookieSize) {
2171  Address numElementsPtr =
2172  CGF.Builder.CreateElementBitCast(allocPtr, CGF.SizeTy);
2173  return CGF.Builder.CreateLoad(numElementsPtr);
2174 }
2175 
2176 Address MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
2177  Address newPtr,
2178  llvm::Value *numElements,
2179  const CXXNewExpr *expr,
2180  QualType elementType) {
2181  assert(requiresArrayCookie(expr));
2182 
2183  // The size of the cookie.
2184  CharUnits cookieSize = getArrayCookieSizeImpl(elementType);
2185 
2186  // Compute an offset to the cookie.
2187  Address cookiePtr = newPtr;
2188 
2189  // Write the number of elements into the appropriate slot.
2190  Address numElementsPtr
2191  = CGF.Builder.CreateElementBitCast(cookiePtr, CGF.SizeTy);
2192  CGF.Builder.CreateStore(numElements, numElementsPtr);
2193 
2194  // Finally, compute a pointer to the actual data buffer by skipping
2195  // over the cookie completely.
2196  return CGF.Builder.CreateConstInBoundsByteGEP(newPtr, cookieSize);
2197 }
2198 
2200  llvm::Constant *Dtor,
2201  llvm::Constant *Addr) {
2202  // Create a function which calls the destructor.
2203  llvm::Constant *DtorStub = CGF.createAtExitStub(VD, Dtor, Addr);
2204 
2205  // extern "C" int __tlregdtor(void (*f)(void));
2206  llvm::FunctionType *TLRegDtorTy = llvm::FunctionType::get(
2207  CGF.IntTy, DtorStub->getType(), /*IsVarArg=*/false);
2208 
2209  llvm::Constant *TLRegDtor = CGF.CGM.CreateRuntimeFunction(
2210  TLRegDtorTy, "__tlregdtor", llvm::AttributeList(), /*Local=*/true);
2211  if (llvm::Function *TLRegDtorFn = dyn_cast<llvm::Function>(TLRegDtor))
2212  TLRegDtorFn->setDoesNotThrow();
2213 
2214  CGF.EmitNounwindRuntimeCall(TLRegDtor, DtorStub);
2215 }
2216 
2217 void MicrosoftCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
2218  llvm::Constant *Dtor,
2219  llvm::Constant *Addr) {
2220  if (D.getTLSKind())
2221  return emitGlobalDtorWithTLRegDtor(CGF, D, Dtor, Addr);
2222 
2223  // The default behavior is to use atexit.
2224  CGF.registerGlobalDtorWithAtExit(D, Dtor, Addr);
2225 }
2226 
2227 void MicrosoftCXXABI::EmitThreadLocalInitFuncs(
2228  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
2229  ArrayRef<llvm::Function *> CXXThreadLocalInits,
2230  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) {
2231  if (CXXThreadLocalInits.empty())
2232  return;
2233 
2234  CGM.AppendLinkerOptions(CGM.getTarget().getTriple().getArch() ==
2235  llvm::Triple::x86
2236  ? "/include:___dyn_tls_init@12"
2237  : "/include:__dyn_tls_init");
2238 
2239  // This will create a GV in the .CRT$XDU section. It will point to our
2240  // initialization function. The CRT will call all of these function
2241  // pointers at start-up time and, eventually, at thread-creation time.
2242  auto AddToXDU = [&CGM](llvm::Function *InitFunc) {
2243  llvm::GlobalVariable *InitFuncPtr = new llvm::GlobalVariable(
2244  CGM.getModule(), InitFunc->getType(), /*IsConstant=*/true,
2246  Twine(InitFunc->getName(), "$initializer$"));
2247  InitFuncPtr->setSection(".CRT$XDU");
2248  // This variable has discardable linkage, we have to add it to @llvm.used to
2249  // ensure it won't get discarded.
2250  CGM.addUsedGlobal(InitFuncPtr);
2251  return InitFuncPtr;
2252  };
2253 
2254  std::vector<llvm::Function *> NonComdatInits;
2255  for (size_t I = 0, E = CXXThreadLocalInitVars.size(); I != E; ++I) {
2256  llvm::GlobalVariable *GV = cast<llvm::GlobalVariable>(
2257  CGM.GetGlobalValue(CGM.getMangledName(CXXThreadLocalInitVars[I])));
2258  llvm::Function *F = CXXThreadLocalInits[I];
2259 
2260  // If the GV is already in a comdat group, then we have to join it.
2261  if (llvm::Comdat *C = GV->getComdat())
2262  AddToXDU(F)->setComdat(C);
2263  else
2264  NonComdatInits.push_back(F);
2265  }
2266 
2267  if (!NonComdatInits.empty()) {
2268  llvm::FunctionType *FTy =
2269  llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
2270  llvm::Function *InitFunc = CGM.CreateGlobalInitOrDestructFunction(
2271  FTy, "__tls_init", CGM.getTypes().arrangeNullaryFunction(),
2272  SourceLocation(), /*TLS=*/true);
2273  CodeGenFunction(CGM).GenerateCXXGlobalInitFunc(InitFunc, NonComdatInits);
2274 
2275  AddToXDU(InitFunc);
2276  }
2277 }
2278 
2279 LValue MicrosoftCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
2280  const VarDecl *VD,
2281  QualType LValType) {
2282  CGF.CGM.ErrorUnsupported(VD, "thread wrappers");
2283  return LValue();
2284 }
2285 
2287  StringRef VarName("_Init_thread_epoch");
2288  CharUnits Align = CGM.getIntAlign();
2289  if (auto *GV = CGM.getModule().getNamedGlobal(VarName))
2290  return ConstantAddress(GV, Align);
2291  auto *GV = new llvm::GlobalVariable(
2292  CGM.getModule(), CGM.IntTy,
2293  /*Constant=*/false, llvm::GlobalVariable::ExternalLinkage,
2294  /*Initializer=*/nullptr, VarName,
2295  /*InsertBefore=*/nullptr, llvm::GlobalVariable::GeneralDynamicTLSModel);
2296  GV->setAlignment(Align.getQuantity());
2297  return ConstantAddress(GV, Align);
2298 }
2299 
2300 static llvm::Constant *getInitThreadHeaderFn(CodeGenModule &CGM) {
2301  llvm::FunctionType *FTy =
2302  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2303  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2304  return CGM.CreateRuntimeFunction(
2305  FTy, "_Init_thread_header",
2306  llvm::AttributeList::get(CGM.getLLVMContext(),
2307  llvm::AttributeList::FunctionIndex,
2308  llvm::Attribute::NoUnwind),
2309  /*Local=*/true);
2310 }
2311 
2312 static llvm::Constant *getInitThreadFooterFn(CodeGenModule &CGM) {
2313  llvm::FunctionType *FTy =
2314  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2315  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2316  return CGM.CreateRuntimeFunction(
2317  FTy, "_Init_thread_footer",
2318  llvm::AttributeList::get(CGM.getLLVMContext(),
2319  llvm::AttributeList::FunctionIndex,
2320  llvm::Attribute::NoUnwind),
2321  /*Local=*/true);
2322 }
2323 
2324 static llvm::Constant *getInitThreadAbortFn(CodeGenModule &CGM) {
2325  llvm::FunctionType *FTy =
2326  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2327  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2328  return CGM.CreateRuntimeFunction(
2329  FTy, "_Init_thread_abort",
2330  llvm::AttributeList::get(CGM.getLLVMContext(),
2331  llvm::AttributeList::FunctionIndex,
2332  llvm::Attribute::NoUnwind),
2333  /*Local=*/true);
2334 }
2335 
2336 namespace {
2337 struct ResetGuardBit final : EHScopeStack::Cleanup {
2338  Address Guard;
2339  unsigned GuardNum;
2340  ResetGuardBit(Address Guard, unsigned GuardNum)
2341  : Guard(Guard), GuardNum(GuardNum) {}
2342 
2343  void Emit(CodeGenFunction &CGF, Flags flags) override {
2344  // Reset the bit in the mask so that the static variable may be
2345  // reinitialized.
2346  CGBuilderTy &Builder = CGF.Builder;
2347  llvm::LoadInst *LI = Builder.CreateLoad(Guard);
2348  llvm::ConstantInt *Mask =
2349  llvm::ConstantInt::get(CGF.IntTy, ~(1ULL << GuardNum));
2350  Builder.CreateStore(Builder.CreateAnd(LI, Mask), Guard);
2351  }
2352 };
2353 
2354 struct CallInitThreadAbort final : EHScopeStack::Cleanup {
2355  llvm::Value *Guard;
2356  CallInitThreadAbort(Address Guard) : Guard(Guard.getPointer()) {}
2357 
2358  void Emit(CodeGenFunction &CGF, Flags flags) override {
2359  // Calling _Init_thread_abort will reset the guard's state.
2361  }
2362 };
2363 }
2364 
2365 void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
2366  llvm::GlobalVariable *GV,
2367  bool PerformInit) {
2368  // MSVC only uses guards for static locals.
2369  if (!D.isStaticLocal()) {
2370  assert(GV->hasWeakLinkage() || GV->hasLinkOnceLinkage());
2371  // GlobalOpt is allowed to discard the initializer, so use linkonce_odr.
2372  llvm::Function *F = CGF.CurFn;
2373  F->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
2374  F->setComdat(CGM.getModule().getOrInsertComdat(F->getName()));
2375  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2376  return;
2377  }
2378 
2379  bool ThreadlocalStatic = D.getTLSKind();
2380  bool ThreadsafeStatic = getContext().getLangOpts().ThreadsafeStatics;
2381 
2382  // Thread-safe static variables which aren't thread-specific have a
2383  // per-variable guard.
2384  bool HasPerVariableGuard = ThreadsafeStatic && !ThreadlocalStatic;
2385 
2386  CGBuilderTy &Builder = CGF.Builder;
2387  llvm::IntegerType *GuardTy = CGF.Int32Ty;
2388  llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0);
2389  CharUnits GuardAlign = CharUnits::fromQuantity(4);
2390 
2391  // Get the guard variable for this function if we have one already.
2392  GuardInfo *GI = nullptr;
2393  if (ThreadlocalStatic)
2394  GI = &ThreadLocalGuardVariableMap[D.getDeclContext()];
2395  else if (!ThreadsafeStatic)
2396  GI = &GuardVariableMap[D.getDeclContext()];
2397 
2398  llvm::GlobalVariable *GuardVar = GI ? GI->Guard : nullptr;
2399  unsigned GuardNum;
2400  if (D.isExternallyVisible()) {
2401  // Externally visible variables have to be numbered in Sema to properly
2402  // handle unreachable VarDecls.
2403  GuardNum = getContext().getStaticLocalNumber(&D);
2404  assert(GuardNum > 0);
2405  GuardNum--;
2406  } else if (HasPerVariableGuard) {
2407  GuardNum = ThreadSafeGuardNumMap[D.getDeclContext()]++;
2408  } else {
2409  // Non-externally visible variables are numbered here in CodeGen.
2410  GuardNum = GI->BitIndex++;
2411  }
2412 
2413  if (!HasPerVariableGuard && GuardNum >= 32) {
2414  if (D.isExternallyVisible())
2415  ErrorUnsupportedABI(CGF, "more than 32 guarded initializations");
2416  GuardNum %= 32;
2417  GuardVar = nullptr;
2418  }
2419 
2420  if (!GuardVar) {
2421  // Mangle the name for the guard.
2422  SmallString<256> GuardName;
2423  {
2424  llvm::raw_svector_ostream Out(GuardName);
2425  if (HasPerVariableGuard)
2426  getMangleContext().mangleThreadSafeStaticGuardVariable(&D, GuardNum,
2427  Out);
2428  else
2429  getMangleContext().mangleStaticGuardVariable(&D, Out);
2430  }
2431 
2432  // Create the guard variable with a zero-initializer. Just absorb linkage,
2433  // visibility and dll storage class from the guarded variable.
2434  GuardVar =
2435  new llvm::GlobalVariable(CGM.getModule(), GuardTy, /*isConstant=*/false,
2436  GV->getLinkage(), Zero, GuardName.str());
2437  GuardVar->setVisibility(GV->getVisibility());
2438  GuardVar->setDLLStorageClass(GV->getDLLStorageClass());
2439  GuardVar->setAlignment(GuardAlign.getQuantity());
2440  if (GuardVar->isWeakForLinker())
2441  GuardVar->setComdat(
2442  CGM.getModule().getOrInsertComdat(GuardVar->getName()));
2443  if (D.getTLSKind())
2444  GuardVar->setThreadLocal(true);
2445  if (GI && !HasPerVariableGuard)
2446  GI->Guard = GuardVar;
2447  }
2448 
2449  ConstantAddress GuardAddr(GuardVar, GuardAlign);
2450 
2451  assert(GuardVar->getLinkage() == GV->getLinkage() &&
2452  "static local from the same function had different linkage");
2453 
2454  if (!HasPerVariableGuard) {
2455  // Pseudo code for the test:
2456  // if (!(GuardVar & MyGuardBit)) {
2457  // GuardVar |= MyGuardBit;
2458  // ... initialize the object ...;
2459  // }
2460 
2461  // Test our bit from the guard variable.
2462  llvm::ConstantInt *Bit = llvm::ConstantInt::get(GuardTy, 1ULL << GuardNum);
2463  llvm::LoadInst *LI = Builder.CreateLoad(GuardAddr);
2464  llvm::Value *IsInitialized =
2465  Builder.CreateICmpNE(Builder.CreateAnd(LI, Bit), Zero);
2466  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2467  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2468  Builder.CreateCondBr(IsInitialized, EndBlock, InitBlock);
2469 
2470  // Set our bit in the guard variable and emit the initializer and add a global
2471  // destructor if appropriate.
2472  CGF.EmitBlock(InitBlock);
2473  Builder.CreateStore(Builder.CreateOr(LI, Bit), GuardAddr);
2474  CGF.EHStack.pushCleanup<ResetGuardBit>(EHCleanup, GuardAddr, GuardNum);
2475  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2476  CGF.PopCleanupBlock();
2477  Builder.CreateBr(EndBlock);
2478 
2479  // Continue.
2480  CGF.EmitBlock(EndBlock);
2481  } else {
2482  // Pseudo code for the test:
2483  // if (TSS > _Init_thread_epoch) {
2484  // _Init_thread_header(&TSS);
2485  // if (TSS == -1) {
2486  // ... initialize the object ...;
2487  // _Init_thread_footer(&TSS);
2488  // }
2489  // }
2490  //
2491  // The algorithm is almost identical to what can be found in the appendix
2492  // found in N2325.
2493 
2494  // This BasicBLock determines whether or not we have any work to do.
2495  llvm::LoadInst *FirstGuardLoad = Builder.CreateLoad(GuardAddr);
2496  FirstGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2497  llvm::LoadInst *InitThreadEpoch =
2498  Builder.CreateLoad(getInitThreadEpochPtr(CGM));
2499  llvm::Value *IsUninitialized =
2500  Builder.CreateICmpSGT(FirstGuardLoad, InitThreadEpoch);
2501  llvm::BasicBlock *AttemptInitBlock = CGF.createBasicBlock("init.attempt");
2502  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2503  Builder.CreateCondBr(IsUninitialized, AttemptInitBlock, EndBlock);
2504 
2505  // This BasicBlock attempts to determine whether or not this thread is
2506  // responsible for doing the initialization.
2507  CGF.EmitBlock(AttemptInitBlock);
2509  GuardAddr.getPointer());
2510  llvm::LoadInst *SecondGuardLoad = Builder.CreateLoad(GuardAddr);
2511  SecondGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2512  llvm::Value *ShouldDoInit =
2513  Builder.CreateICmpEQ(SecondGuardLoad, getAllOnesInt());
2514  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2515  Builder.CreateCondBr(ShouldDoInit, InitBlock, EndBlock);
2516 
2517  // Ok, we ended up getting selected as the initializing thread.
2518  CGF.EmitBlock(InitBlock);
2519  CGF.EHStack.pushCleanup<CallInitThreadAbort>(EHCleanup, GuardAddr);
2520  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2521  CGF.PopCleanupBlock();
2523  GuardAddr.getPointer());
2524  Builder.CreateBr(EndBlock);
2525 
2526  CGF.EmitBlock(EndBlock);
2527  }
2528 }
2529 
2530 bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
2531  // Null-ness for function memptrs only depends on the first field, which is
2532  // the function pointer. The rest don't matter, so we can zero initialize.
2533  if (MPT->isMemberFunctionPointer())
2534  return true;
2535 
2536  // The virtual base adjustment field is always -1 for null, so if we have one
2537  // we can't zero initialize. The field offset is sometimes also -1 if 0 is a
2538  // valid field offset.
2539  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2540  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2541  return (!MSInheritanceAttr::hasVBTableOffsetField(Inheritance) &&
2542  RD->nullFieldOffsetIsZero());
2543 }
2544 
2545 llvm::Type *
2546 MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
2547  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2548  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2550  if (MPT->isMemberFunctionPointer())
2551  fields.push_back(CGM.VoidPtrTy); // FunctionPointerOrVirtualThunk
2552  else
2553  fields.push_back(CGM.IntTy); // FieldOffset
2554 
2555  if (MSInheritanceAttr::hasNVOffsetField(MPT->isMemberFunctionPointer(),
2556  Inheritance))
2557  fields.push_back(CGM.IntTy);
2558  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
2559  fields.push_back(CGM.IntTy);
2560  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2561  fields.push_back(CGM.IntTy); // VirtualBaseAdjustmentOffset
2562 
2563  if (fields.size() == 1)
2564  return fields[0];
2565  return llvm::StructType::get(CGM.getLLVMContext(), fields);
2566 }
2567 
2568 void MicrosoftCXXABI::
2569 GetNullMemberPointerFields(const MemberPointerType *MPT,
2571  assert(fields.empty());
2572  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2573  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2574  if (MPT->isMemberFunctionPointer()) {
2575  // FunctionPointerOrVirtualThunk
2576  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2577  } else {
2578  if (RD->nullFieldOffsetIsZero())
2579  fields.push_back(getZeroInt()); // FieldOffset
2580  else
2581  fields.push_back(getAllOnesInt()); // FieldOffset
2582  }
2583 
2584  if (MSInheritanceAttr::hasNVOffsetField(MPT->isMemberFunctionPointer(),
2585  Inheritance))
2586  fields.push_back(getZeroInt());
2587  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
2588  fields.push_back(getZeroInt());
2589  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2590  fields.push_back(getAllOnesInt());
2591 }
2592 
2593 llvm::Constant *
2594 MicrosoftCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
2596  GetNullMemberPointerFields(MPT, fields);
2597  if (fields.size() == 1)
2598  return fields[0];
2599  llvm::Constant *Res = llvm::ConstantStruct::getAnon(fields);
2600  assert(Res->getType() == ConvertMemberPointerType(MPT));
2601  return Res;
2602 }
2603 
2604 llvm::Constant *
2605 MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
2606  bool IsMemberFunction,
2607  const CXXRecordDecl *RD,
2608  CharUnits NonVirtualBaseAdjustment,
2609  unsigned VBTableIndex) {
2610  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2611 
2612  // Single inheritance class member pointer are represented as scalars instead
2613  // of aggregates.
2614  if (MSInheritanceAttr::hasOnlyOneField(IsMemberFunction, Inheritance))
2615  return FirstField;
2616 
2618  fields.push_back(FirstField);
2619 
2620  if (MSInheritanceAttr::hasNVOffsetField(IsMemberFunction, Inheritance))
2621  fields.push_back(llvm::ConstantInt::get(
2622  CGM.IntTy, NonVirtualBaseAdjustment.getQuantity()));
2623 
2624  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance)) {
2625  CharUnits Offs = CharUnits::Zero();
2626  if (VBTableIndex)
2627  Offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
2628  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, Offs.getQuantity()));
2629  }
2630 
2631  // The rest of the fields are adjusted by conversions to a more derived class.
2632  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2633  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBTableIndex));
2634 
2635  return llvm::ConstantStruct::getAnon(fields);
2636 }
2637 
2638 llvm::Constant *
2639 MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
2640  CharUnits offset) {
2641  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2642  if (RD->getMSInheritanceModel() ==
2643  MSInheritanceAttr::Keyword_virtual_inheritance)
2644  offset -= getContext().getOffsetOfBaseWithVBPtr(RD);
2645  llvm::Constant *FirstField =
2646  llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity());
2647  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD,
2648  CharUnits::Zero(), /*VBTableIndex=*/0);
2649 }
2650 
2651 llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP,
2652  QualType MPType) {
2653  const MemberPointerType *DstTy = MPType->castAs<MemberPointerType>();
2654  const ValueDecl *MPD = MP.getMemberPointerDecl();
2655  if (!MPD)
2656  return EmitNullMemberPointer(DstTy);
2657 
2658  ASTContext &Ctx = getContext();
2659  ArrayRef<const CXXRecordDecl *> MemberPointerPath = MP.getMemberPointerPath();
2660 
2661  llvm::Constant *C;
2662  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) {
2663  C = EmitMemberFunctionPointer(MD);
2664  } else {
2665  CharUnits FieldOffset = Ctx.toCharUnitsFromBits(Ctx.getFieldOffset(MPD));
2666  C = EmitMemberDataPointer(DstTy, FieldOffset);
2667  }
2668 
2669  if (!MemberPointerPath.empty()) {
2670  const CXXRecordDecl *SrcRD = cast<CXXRecordDecl>(MPD->getDeclContext());
2671  const Type *SrcRecTy = Ctx.getTypeDeclType(SrcRD).getTypePtr();
2672  const MemberPointerType *SrcTy =
2673  Ctx.getMemberPointerType(DstTy->getPointeeType(), SrcRecTy)
2674  ->castAs<MemberPointerType>();
2675 
2676  bool DerivedMember = MP.isMemberPointerToDerivedMember();
2677  SmallVector<const CXXBaseSpecifier *, 4> DerivedToBasePath;
2678  const CXXRecordDecl *PrevRD = SrcRD;
2679  for (const CXXRecordDecl *PathElem : MemberPointerPath) {
2680  const CXXRecordDecl *Base = nullptr;
2681  const CXXRecordDecl *Derived = nullptr;
2682  if (DerivedMember) {
2683  Base = PathElem;
2684  Derived = PrevRD;
2685  } else {
2686  Base = PrevRD;
2687  Derived = PathElem;
2688  }
2689  for (const CXXBaseSpecifier &BS : Derived->bases())
2690  if (BS.getType()->getAsCXXRecordDecl()->getCanonicalDecl() ==
2691  Base->getCanonicalDecl())
2692  DerivedToBasePath.push_back(&BS);
2693  PrevRD = PathElem;
2694  }
2695  assert(DerivedToBasePath.size() == MemberPointerPath.size());
2696 
2697  CastKind CK = DerivedMember ? CK_DerivedToBaseMemberPointer
2698  : CK_BaseToDerivedMemberPointer;
2699  C = EmitMemberPointerConversion(SrcTy, DstTy, CK, DerivedToBasePath.begin(),
2700  DerivedToBasePath.end(), C);
2701  }
2702  return C;
2703 }
2704 
2705 llvm::Constant *
2706 MicrosoftCXXABI::EmitMemberFunctionPointer(const CXXMethodDecl *MD) {
2707  assert(MD->isInstance() && "Member function must not be static!");
2708 
2709  MD = MD->getCanonicalDecl();
2710  CharUnits NonVirtualBaseAdjustment = CharUnits::Zero();
2711  const CXXRecordDecl *RD = MD->getParent()->getMostRecentDecl();
2712  CodeGenTypes &Types = CGM.getTypes();
2713 
2714  unsigned VBTableIndex = 0;
2715  llvm::Constant *FirstField;
2716  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
2717  if (!MD->isVirtual()) {
2718  llvm::Type *Ty;
2719  // Check whether the function has a computable LLVM signature.
2720  if (Types.isFuncTypeConvertible(FPT)) {
2721  // The function has a computable LLVM signature; use the correct type.
2722  Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD));
2723  } else {
2724  // Use an arbitrary non-function type to tell GetAddrOfFunction that the
2725  // function type is incomplete.
2726  Ty = CGM.PtrDiffTy;
2727  }
2728  FirstField = CGM.GetAddrOfFunction(MD, Ty);
2729  } else {
2730  auto &VTableContext = CGM.getMicrosoftVTableContext();
2732  VTableContext.getMethodVFTableLocation(MD);
2733  FirstField = EmitVirtualMemPtrThunk(MD, ML);
2734  // Include the vfptr adjustment if the method is in a non-primary vftable.
2735  NonVirtualBaseAdjustment += ML.VFPtrOffset;
2736  if (ML.VBase)
2737  VBTableIndex = VTableContext.getVBTableIndex(RD, ML.VBase) * 4;
2738  }
2739 
2740  if (VBTableIndex == 0 &&
2741  RD->getMSInheritanceModel() ==
2742  MSInheritanceAttr::Keyword_virtual_inheritance)
2743  NonVirtualBaseAdjustment -= getContext().getOffsetOfBaseWithVBPtr(RD);
2744 
2745  // The rest of the fields are common with data member pointers.
2746  FirstField = llvm::ConstantExpr::getBitCast(FirstField, CGM.VoidPtrTy);
2747  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD,
2748  NonVirtualBaseAdjustment, VBTableIndex);
2749 }
2750 
2751 /// Member pointers are the same if they're either bitwise identical *or* both
2752 /// null. Null-ness for function members is determined by the first field,
2753 /// while for data member pointers we must compare all fields.
2754 llvm::Value *
2755 MicrosoftCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
2756  llvm::Value *L,
2757  llvm::Value *R,
2758  const MemberPointerType *MPT,
2759  bool Inequality) {
2760  CGBuilderTy &Builder = CGF.Builder;
2761 
2762  // Handle != comparisons by switching the sense of all boolean operations.
2763  llvm::ICmpInst::Predicate Eq;
2764  llvm::Instruction::BinaryOps And, Or;
2765  if (Inequality) {
2766  Eq = llvm::ICmpInst::ICMP_NE;
2767  And = llvm::Instruction::Or;
2769  } else {
2770  Eq = llvm::ICmpInst::ICMP_EQ;
2771  And = llvm::Instruction::And;
2772  Or = llvm::Instruction::Or;
2773  }
2774 
2775  // If this is a single field member pointer (single inheritance), this is a
2776  // single icmp.
2777  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2778  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2779  if (MSInheritanceAttr::hasOnlyOneField(MPT->isMemberFunctionPointer(),
2780  Inheritance))
2781  return Builder.CreateICmp(Eq, L, R);
2782 
2783  // Compare the first field.
2784  llvm::Value *L0 = Builder.CreateExtractValue(L, 0, "lhs.0");
2785  llvm::Value *R0 = Builder.CreateExtractValue(R, 0, "rhs.0");
2786  llvm::Value *Cmp0 = Builder.CreateICmp(Eq, L0, R0, "memptr.cmp.first");
2787 
2788  // Compare everything other than the first field.
2789  llvm::Value *Res = nullptr;
2790  llvm::StructType *LType = cast<llvm::StructType>(L->getType());
2791  for (unsigned I = 1, E = LType->getNumElements(); I != E; ++I) {
2792  llvm::Value *LF = Builder.CreateExtractValue(L, I);
2793  llvm::Value *RF = Builder.CreateExtractValue(R, I);
2794  llvm::Value *Cmp = Builder.CreateICmp(Eq, LF, RF, "memptr.cmp.rest");
2795  if (Res)
2796  Res = Builder.CreateBinOp(And, Res, Cmp);
2797  else
2798  Res = Cmp;
2799  }
2800 
2801  // Check if the first field is 0 if this is a function pointer.
2802  if (MPT->isMemberFunctionPointer()) {
2803  // (l1 == r1 && ...) || l0 == 0
2804  llvm::Value *Zero = llvm::Constant::getNullValue(L0->getType());
2805  llvm::Value *IsZero = Builder.CreateICmp(Eq, L0, Zero, "memptr.cmp.iszero");
2806  Res = Builder.CreateBinOp(Or, Res, IsZero);
2807  }
2808 
2809  // Combine the comparison of the first field, which must always be true for
2810  // this comparison to succeeed.
2811  return Builder.CreateBinOp(And, Res, Cmp0, "memptr.cmp");
2812 }
2813 
2814 llvm::Value *
2815 MicrosoftCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
2816  llvm::Value *MemPtr,
2817  const MemberPointerType *MPT) {
2818  CGBuilderTy &Builder = CGF.Builder;
2820  // We only need one field for member functions.
2821  if (MPT->isMemberFunctionPointer())
2822  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2823  else
2824  GetNullMemberPointerFields(MPT, fields);
2825  assert(!fields.empty());
2826  llvm::Value *FirstField = MemPtr;
2827  if (MemPtr->getType()->isStructTy())
2828  FirstField = Builder.CreateExtractValue(MemPtr, 0);
2829  llvm::Value *Res = Builder.CreateICmpNE(FirstField, fields[0], "memptr.cmp0");
2830 
2831  // For function member pointers, we only need to test the function pointer
2832  // field. The other fields if any can be garbage.
2833  if (MPT->isMemberFunctionPointer())
2834  return Res;
2835 
2836  // Otherwise, emit a series of compares and combine the results.
2837  for (int I = 1, E = fields.size(); I < E; ++I) {
2838  llvm::Value *Field = Builder.CreateExtractValue(MemPtr, I);
2839  llvm::Value *Next = Builder.CreateICmpNE(Field, fields[I], "memptr.cmp");
2840  Res = Builder.CreateOr(Res, Next, "memptr.tobool");
2841  }
2842  return Res;
2843 }
2844 
2845 bool MicrosoftCXXABI::MemberPointerConstantIsNull(const MemberPointerType *MPT,
2846  llvm::Constant *Val) {
2847  // Function pointers are null if the pointer in the first field is null.
2848  if (MPT->isMemberFunctionPointer()) {
2849  llvm::Constant *FirstField = Val->getType()->isStructTy() ?
2850  Val->getAggregateElement(0U) : Val;
2851  return FirstField->isNullValue();
2852  }
2853 
2854  // If it's not a function pointer and it's zero initializable, we can easily
2855  // check zero.
2856  if (isZeroInitializable(MPT) && Val->isNullValue())
2857  return true;
2858 
2859  // Otherwise, break down all the fields for comparison. Hopefully these
2860  // little Constants are reused, while a big null struct might not be.
2862  GetNullMemberPointerFields(MPT, Fields);
2863  if (Fields.size() == 1) {
2864  assert(Val->getType()->isIntegerTy());
2865  return Val == Fields[0];
2866  }
2867 
2868  unsigned I, E;
2869  for (I = 0, E = Fields.size(); I != E; ++I) {
2870  if (Val->getAggregateElement(I) != Fields[I])
2871  break;
2872  }
2873  return I == E;
2874 }
2875 
2876 llvm::Value *
2877 MicrosoftCXXABI::GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
2878  Address This,
2879  llvm::Value *VBPtrOffset,
2880  llvm::Value *VBTableOffset,
2881  llvm::Value **VBPtrOut) {
2882  CGBuilderTy &Builder = CGF.Builder;
2883  // Load the vbtable pointer from the vbptr in the instance.
2884  This = Builder.CreateElementBitCast(This, CGM.Int8Ty);
2885  llvm::Value *VBPtr =
2886  Builder.CreateInBoundsGEP(This.getPointer(), VBPtrOffset, "vbptr");
2887  if (VBPtrOut) *VBPtrOut = VBPtr;
2888  VBPtr = Builder.CreateBitCast(VBPtr,
2889  CGM.Int32Ty->getPointerTo(0)->getPointerTo(This.getAddressSpace()));
2890 
2891  CharUnits VBPtrAlign;
2892  if (auto CI = dyn_cast<llvm::ConstantInt>(VBPtrOffset)) {
2893  VBPtrAlign = This.getAlignment().alignmentAtOffset(
2894  CharUnits::fromQuantity(CI->getSExtValue()));
2895  } else {
2896  VBPtrAlign = CGF.getPointerAlign();
2897  }
2898 
2899  llvm::Value *VBTable = Builder.CreateAlignedLoad(VBPtr, VBPtrAlign, "vbtable");
2900 
2901  // Translate from byte offset to table index. It improves analyzability.
2902  llvm::Value *VBTableIndex = Builder.CreateAShr(
2903  VBTableOffset, llvm::ConstantInt::get(VBTableOffset->getType(), 2),
2904  "vbtindex", /*isExact=*/true);
2905 
2906  // Load an i32 offset from the vb-table.
2907  llvm::Value *VBaseOffs = Builder.CreateInBoundsGEP(VBTable, VBTableIndex);
2908  VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0));
2909  return Builder.CreateAlignedLoad(VBaseOffs, CharUnits::fromQuantity(4),
2910  "vbase_offs");
2911 }
2912 
2913 // Returns an adjusted base cast to i8*, since we do more address arithmetic on
2914 // it.
2915 llvm::Value *MicrosoftCXXABI::AdjustVirtualBase(
2916  CodeGenFunction &CGF, const Expr *E, const CXXRecordDecl *RD,
2917  Address Base, llvm::Value *VBTableOffset, llvm::Value *VBPtrOffset) {
2918  CGBuilderTy &Builder = CGF.Builder;
2919  Base = Builder.CreateElementBitCast(Base, CGM.Int8Ty);
2920  llvm::BasicBlock *OriginalBB = nullptr;
2921  llvm::BasicBlock *SkipAdjustBB = nullptr;
2922  llvm::BasicBlock *VBaseAdjustBB = nullptr;
2923 
2924  // In the unspecified inheritance model, there might not be a vbtable at all,
2925  // in which case we need to skip the virtual base lookup. If there is a
2926  // vbtable, the first entry is a no-op entry that gives back the original
2927  // base, so look for a virtual base adjustment offset of zero.
2928  if (VBPtrOffset) {
2929  OriginalBB = Builder.GetInsertBlock();
2930  VBaseAdjustBB = CGF.createBasicBlock("memptr.vadjust");
2931  SkipAdjustBB = CGF.createBasicBlock("memptr.skip_vadjust");
2932  llvm::Value *IsVirtual =
2933  Builder.CreateICmpNE(VBTableOffset, getZeroInt(),
2934  "memptr.is_vbase");
2935  Builder.CreateCondBr(IsVirtual, VBaseAdjustBB, SkipAdjustBB);
2936  CGF.EmitBlock(VBaseAdjustBB);
2937  }
2938 
2939  // If we weren't given a dynamic vbptr offset, RD should be complete and we'll
2940  // know the vbptr offset.
2941  if (!VBPtrOffset) {
2942  CharUnits offs = CharUnits::Zero();
2943  if (!RD->hasDefinition()) {
2944  DiagnosticsEngine &Diags = CGF.CGM.getDiags();
2945  unsigned DiagID = Diags.getCustomDiagID(
2947  "member pointer representation requires a "
2948  "complete class type for %0 to perform this expression");
2949  Diags.Report(E->getExprLoc(), DiagID) << RD << E->getSourceRange();
2950  } else if (RD->getNumVBases())
2951  offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
2952  VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity());
2953  }
2954  llvm::Value *VBPtr = nullptr;
2955  llvm::Value *VBaseOffs =
2956  GetVBaseOffsetFromVBPtr(CGF, Base, VBPtrOffset, VBTableOffset, &VBPtr);
2957  llvm::Value *AdjustedBase = Builder.CreateInBoundsGEP(VBPtr, VBaseOffs);
2958 
2959  // Merge control flow with the case where we didn't have to adjust.
2960  if (VBaseAdjustBB) {
2961  Builder.CreateBr(SkipAdjustBB);
2962  CGF.EmitBlock(SkipAdjustBB);
2963  llvm::PHINode *Phi = Builder.CreatePHI(CGM.Int8PtrTy, 2, "memptr.base");
2964  Phi->addIncoming(Base.getPointer(), OriginalBB);
2965  Phi->addIncoming(AdjustedBase, VBaseAdjustBB);
2966  return Phi;
2967  }
2968  return AdjustedBase;
2969 }
2970 
2971 llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
2972  CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
2973  const MemberPointerType *MPT) {
2974  assert(MPT->isMemberDataPointer());
2975  unsigned AS = Base.getAddressSpace();
2976  llvm::Type *PType =
2977  CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
2978  CGBuilderTy &Builder = CGF.Builder;
2979  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2980  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2981 
2982  // Extract the fields we need, regardless of model. We'll apply them if we
2983  // have them.
2984  llvm::Value *FieldOffset = MemPtr;
2985  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
2986  llvm::Value *VBPtrOffset = nullptr;
2987  if (MemPtr->getType()->isStructTy()) {
2988  // We need to extract values.
2989  unsigned I = 0;
2990  FieldOffset = Builder.CreateExtractValue(MemPtr, I++);
2991  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
2992  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
2993  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2994  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
2995  }
2996 
2997  llvm::Value *Addr;
2998  if (VirtualBaseAdjustmentOffset) {
2999  Addr = AdjustVirtualBase(CGF, E, RD, Base, VirtualBaseAdjustmentOffset,
3000  VBPtrOffset);
3001  } else {
3002  Addr = Base.getPointer();
3003  }
3004 
3005  // Cast to char*.
3006  Addr = Builder.CreateBitCast(Addr, CGF.Int8Ty->getPointerTo(AS));
3007 
3008  // Apply the offset, which we assume is non-null.
3009  Addr = Builder.CreateInBoundsGEP(Addr, FieldOffset, "memptr.offset");
3010 
3011  // Cast the address to the appropriate pointer type, adopting the address
3012  // space of the base pointer.
3013  return Builder.CreateBitCast(Addr, PType);
3014 }
3015 
3016 llvm::Value *
3017 MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
3018  const CastExpr *E,
3019  llvm::Value *Src) {
3020  assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
3021  E->getCastKind() == CK_BaseToDerivedMemberPointer ||
3022  E->getCastKind() == CK_ReinterpretMemberPointer);
3023 
3024  // Use constant emission if we can.
3025  if (isa<llvm::Constant>(Src))
3026  return EmitMemberPointerConversion(E, cast<llvm::Constant>(Src));
3027 
3028  // We may be adding or dropping fields from the member pointer, so we need
3029  // both types and the inheritance models of both records.
3030  const MemberPointerType *SrcTy =
3032  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3033  bool IsFunc = SrcTy->isMemberFunctionPointer();
3034 
3035  // If the classes use the same null representation, reinterpret_cast is a nop.
3036  bool IsReinterpret = E->getCastKind() == CK_ReinterpretMemberPointer;
3037  if (IsReinterpret && IsFunc)
3038  return Src;
3039 
3040  CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3041  CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3042  if (IsReinterpret &&
3043  SrcRD->nullFieldOffsetIsZero() == DstRD->nullFieldOffsetIsZero())
3044  return Src;
3045 
3046  CGBuilderTy &Builder = CGF.Builder;
3047 
3048  // Branch past the conversion if Src is null.
3049  llvm::Value *IsNotNull = EmitMemberPointerIsNotNull(CGF, Src, SrcTy);
3050  llvm::Constant *DstNull = EmitNullMemberPointer(DstTy);
3051 
3052  // C++ 5.2.10p9: The null member pointer value is converted to the null member
3053  // pointer value of the destination type.
3054  if (IsReinterpret) {
3055  // For reinterpret casts, sema ensures that src and dst are both functions
3056  // or data and have the same size, which means the LLVM types should match.
3057  assert(Src->getType() == DstNull->getType());
3058  return Builder.CreateSelect(IsNotNull, Src, DstNull);
3059  }
3060 
3061  llvm::BasicBlock *OriginalBB = Builder.GetInsertBlock();
3062  llvm::BasicBlock *ConvertBB = CGF.createBasicBlock("memptr.convert");
3063  llvm::BasicBlock *ContinueBB = CGF.createBasicBlock("memptr.converted");
3064  Builder.CreateCondBr(IsNotNull, ConvertBB, ContinueBB);
3065  CGF.EmitBlock(ConvertBB);
3066 
3067  llvm::Value *Dst = EmitNonNullMemberPointerConversion(
3068  SrcTy, DstTy, E->getCastKind(), E->path_begin(), E->path_end(), Src,
3069  Builder);
3070 
3071  Builder.CreateBr(ContinueBB);
3072 
3073  // In the continuation, choose between DstNull and Dst.
3074  CGF.EmitBlock(ContinueBB);
3075  llvm::PHINode *Phi = Builder.CreatePHI(DstNull->getType(), 2, "memptr.converted");
3076  Phi->addIncoming(DstNull, OriginalBB);
3077  Phi->addIncoming(Dst, ConvertBB);
3078  return Phi;
3079 }
3080 
3081 llvm::Value *MicrosoftCXXABI::EmitNonNullMemberPointerConversion(
3082  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3085  CGBuilderTy &Builder) {
3086  const CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3087  const CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3088  MSInheritanceAttr::Spelling SrcInheritance = SrcRD->getMSInheritanceModel();
3089  MSInheritanceAttr::Spelling DstInheritance = DstRD->getMSInheritanceModel();
3090  bool IsFunc = SrcTy->isMemberFunctionPointer();
3091  bool IsConstant = isa<llvm::Constant>(Src);
3092 
3093  // Decompose src.
3094  llvm::Value *FirstField = Src;
3095  llvm::Value *NonVirtualBaseAdjustment = getZeroInt();
3096  llvm::Value *VirtualBaseAdjustmentOffset = getZeroInt();
3097  llvm::Value *VBPtrOffset = getZeroInt();
3098  if (!MSInheritanceAttr::hasOnlyOneField(IsFunc, SrcInheritance)) {
3099  // We need to extract values.
3100  unsigned I = 0;
3101  FirstField = Builder.CreateExtractValue(Src, I++);
3102  if (MSInheritanceAttr::hasNVOffsetField(IsFunc, SrcInheritance))
3103  NonVirtualBaseAdjustment = Builder.CreateExtractValue(Src, I++);
3104  if (MSInheritanceAttr::hasVBPtrOffsetField(SrcInheritance))
3105  VBPtrOffset = Builder.CreateExtractValue(Src, I++);
3106  if (MSInheritanceAttr::hasVBTableOffsetField(SrcInheritance))
3107  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(Src, I++);
3108  }
3109 
3110  bool IsDerivedToBase = (CK == CK_DerivedToBaseMemberPointer);
3111  const MemberPointerType *DerivedTy = IsDerivedToBase ? SrcTy : DstTy;
3112  const CXXRecordDecl *DerivedClass = DerivedTy->getMostRecentCXXRecordDecl();
3113 
3114  // For data pointers, we adjust the field offset directly. For functions, we
3115  // have a separate field.
3116  llvm::Value *&NVAdjustField = IsFunc ? NonVirtualBaseAdjustment : FirstField;
3117 
3118  // The virtual inheritance model has a quirk: the virtual base table is always
3119  // referenced when dereferencing a member pointer even if the member pointer
3120  // is non-virtual. This is accounted for by adjusting the non-virtual offset
3121  // to point backwards to the top of the MDC from the first VBase. Undo this
3122  // adjustment to normalize the member pointer.
3123  llvm::Value *SrcVBIndexEqZero =
3124  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3125  if (SrcInheritance == MSInheritanceAttr::Keyword_virtual_inheritance) {
3126  if (int64_t SrcOffsetToFirstVBase =
3127  getContext().getOffsetOfBaseWithVBPtr(SrcRD).getQuantity()) {
3128  llvm::Value *UndoSrcAdjustment = Builder.CreateSelect(
3129  SrcVBIndexEqZero,
3130  llvm::ConstantInt::get(CGM.IntTy, SrcOffsetToFirstVBase),
3131  getZeroInt());
3132  NVAdjustField = Builder.CreateNSWAdd(NVAdjustField, UndoSrcAdjustment);
3133  }
3134  }
3135 
3136  // A non-zero vbindex implies that we are dealing with a source member in a
3137  // floating virtual base in addition to some non-virtual offset. If the
3138  // vbindex is zero, we are dealing with a source that exists in a non-virtual,
3139  // fixed, base. The difference between these two cases is that the vbindex +
3140  // nvoffset *always* point to the member regardless of what context they are
3141  // evaluated in so long as the vbindex is adjusted. A member inside a fixed
3142  // base requires explicit nv adjustment.
3143  llvm::Constant *BaseClassOffset = llvm::ConstantInt::get(
3144  CGM.IntTy,
3145  CGM.computeNonVirtualBaseClassOffset(DerivedClass, PathBegin, PathEnd)
3146  .getQuantity());
3147 
3148  llvm::Value *NVDisp;
3149  if (IsDerivedToBase)
3150  NVDisp = Builder.CreateNSWSub(NVAdjustField, BaseClassOffset, "adj");
3151  else
3152  NVDisp = Builder.CreateNSWAdd(NVAdjustField, BaseClassOffset, "adj");
3153 
3154  NVAdjustField = Builder.CreateSelect(SrcVBIndexEqZero, NVDisp, getZeroInt());
3155 
3156  // Update the vbindex to an appropriate value in the destination because
3157  // SrcRD's vbtable might not be a strict prefix of the one in DstRD.
3158  llvm::Value *DstVBIndexEqZero = SrcVBIndexEqZero;
3159  if (MSInheritanceAttr::hasVBTableOffsetField(DstInheritance) &&
3160  MSInheritanceAttr::hasVBTableOffsetField(SrcInheritance)) {
3161  if (llvm::GlobalVariable *VDispMap =
3162  getAddrOfVirtualDisplacementMap(SrcRD, DstRD)) {
3163  llvm::Value *VBIndex = Builder.CreateExactUDiv(
3164  VirtualBaseAdjustmentOffset, llvm::ConstantInt::get(CGM.IntTy, 4));
3165  if (IsConstant) {
3166  llvm::Constant *Mapping = VDispMap->getInitializer();
3167  VirtualBaseAdjustmentOffset =
3168  Mapping->getAggregateElement(cast<llvm::Constant>(VBIndex));
3169  } else {
3170  llvm::Value *Idxs[] = {getZeroInt(), VBIndex};
3171  VirtualBaseAdjustmentOffset =
3172  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(VDispMap, Idxs),
3174  }
3175 
3176  DstVBIndexEqZero =
3177  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3178  }
3179  }
3180 
3181  // Set the VBPtrOffset to zero if the vbindex is zero. Otherwise, initialize
3182  // it to the offset of the vbptr.
3183  if (MSInheritanceAttr::hasVBPtrOffsetField(DstInheritance)) {
3184  llvm::Value *DstVBPtrOffset = llvm::ConstantInt::get(
3185  CGM.IntTy,
3186  getContext().getASTRecordLayout(DstRD).getVBPtrOffset().getQuantity());
3187  VBPtrOffset =
3188  Builder.CreateSelect(DstVBIndexEqZero, getZeroInt(), DstVBPtrOffset);
3189  }
3190 
3191  // Likewise, apply a similar adjustment so that dereferencing the member
3192  // pointer correctly accounts for the distance between the start of the first
3193  // virtual base and the top of the MDC.
3194  if (DstInheritance == MSInheritanceAttr::Keyword_virtual_inheritance) {
3195  if (int64_t DstOffsetToFirstVBase =
3196  getContext().getOffsetOfBaseWithVBPtr(DstRD).getQuantity()) {
3197  llvm::Value *DoDstAdjustment = Builder.CreateSelect(
3198  DstVBIndexEqZero,
3199  llvm::ConstantInt::get(CGM.IntTy, DstOffsetToFirstVBase),
3200  getZeroInt());
3201  NVAdjustField = Builder.CreateNSWSub(NVAdjustField, DoDstAdjustment);
3202  }
3203  }
3204 
3205  // Recompose dst from the null struct and the adjusted fields from src.
3206  llvm::Value *Dst;
3207  if (MSInheritanceAttr::hasOnlyOneField(IsFunc, DstInheritance)) {
3208  Dst = FirstField;
3209  } else {
3210  Dst = llvm::UndefValue::get(ConvertMemberPointerType(DstTy));
3211  unsigned Idx = 0;
3212  Dst = Builder.CreateInsertValue(Dst, FirstField, Idx++);
3213  if (MSInheritanceAttr::hasNVOffsetField(IsFunc, DstInheritance))
3214  Dst = Builder.CreateInsertValue(Dst, NonVirtualBaseAdjustment, Idx++);
3215  if (MSInheritanceAttr::hasVBPtrOffsetField(DstInheritance))
3216  Dst = Builder.CreateInsertValue(Dst, VBPtrOffset, Idx++);
3217  if (MSInheritanceAttr::hasVBTableOffsetField(DstInheritance))
3218  Dst = Builder.CreateInsertValue(Dst, VirtualBaseAdjustmentOffset, Idx++);
3219  }
3220  return Dst;
3221 }
3222 
3223 llvm::Constant *
3224 MicrosoftCXXABI::EmitMemberPointerConversion(const CastExpr *E,
3225  llvm::Constant *Src) {
3226  const MemberPointerType *SrcTy =
3228  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3229 
3230  CastKind CK = E->getCastKind();
3231 
3232  return EmitMemberPointerConversion(SrcTy, DstTy, CK, E->path_begin(),
3233  E->path_end(), Src);
3234 }
3235 
3236 llvm::Constant *MicrosoftCXXABI::EmitMemberPointerConversion(
3237  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3239  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src) {
3240  assert(CK == CK_DerivedToBaseMemberPointer ||
3241  CK == CK_BaseToDerivedMemberPointer ||
3242  CK == CK_ReinterpretMemberPointer);
3243  // If src is null, emit a new null for dst. We can't return src because dst
3244  // might have a new representation.
3245  if (MemberPointerConstantIsNull(SrcTy, Src))
3246  return EmitNullMemberPointer(DstTy);
3247 
3248  // We don't need to do anything for reinterpret_casts of non-null member
3249  // pointers. We should only get here when the two type representations have
3250  // the same size.
3251  if (CK == CK_ReinterpretMemberPointer)
3252  return Src;
3253 
3254  CGBuilderTy Builder(CGM, CGM.getLLVMContext());
3255  auto *Dst = cast<llvm::Constant>(EmitNonNullMemberPointerConversion(
3256  SrcTy, DstTy, CK, PathBegin, PathEnd, Src, Builder));
3257 
3258  return Dst;
3259 }
3260 
3261 CGCallee MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(
3262  CodeGenFunction &CGF, const Expr *E, Address This,
3263  llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
3264  const MemberPointerType *MPT) {
3265  assert(MPT->isMemberFunctionPointer());
3266  const FunctionProtoType *FPT =
3268  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
3269  llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
3270  CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));
3271  CGBuilderTy &Builder = CGF.Builder;
3272 
3273  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
3274 
3275  // Extract the fields we need, regardless of model. We'll apply them if we
3276  // have them.
3277  llvm::Value *FunctionPointer = MemPtr;
3278  llvm::Value *NonVirtualBaseAdjustment = nullptr;
3279  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
3280  llvm::Value *VBPtrOffset = nullptr;
3281  if (MemPtr->getType()->isStructTy()) {
3282  // We need to extract values.
3283  unsigned I = 0;
3284  FunctionPointer = Builder.CreateExtractValue(MemPtr, I++);
3285  if (MSInheritanceAttr::hasNVOffsetField(MPT, Inheritance))
3286  NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++);
3287  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
3288  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
3289  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
3290  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
3291  }
3292 
3293  if (VirtualBaseAdjustmentOffset) {
3294  ThisPtrForCall = AdjustVirtualBase(CGF, E, RD, This,
3295  VirtualBaseAdjustmentOffset, VBPtrOffset);
3296  } else {
3297  ThisPtrForCall = This.getPointer();
3298  }
3299 
3300  if (NonVirtualBaseAdjustment) {
3301  // Apply the adjustment and cast back to the original struct type.
3302  llvm::Value *Ptr = Builder.CreateBitCast(ThisPtrForCall, CGF.Int8PtrTy);
3303  Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment);
3304  ThisPtrForCall = Builder.CreateBitCast(Ptr, ThisPtrForCall->getType(),
3305  "this.adjusted");
3306  }
3307 
3308  FunctionPointer =
3309  Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo());
3310  CGCallee Callee(FPT, FunctionPointer);
3311  return Callee;
3312 }
3313 
3315  return new MicrosoftCXXABI(CGM);
3316 }
3317 
3318 // MS RTTI Overview:
3319 // The run time type information emitted by cl.exe contains 5 distinct types of
3320 // structures. Many of them reference each other.
3321 //
3322 // TypeInfo: Static classes that are returned by typeid.
3323 //
3324 // CompleteObjectLocator: Referenced by vftables. They contain information
3325 // required for dynamic casting, including OffsetFromTop. They also contain
3326 // a reference to the TypeInfo for the type and a reference to the
3327 // CompleteHierarchyDescriptor for the type.
3328 //
3329 // ClassHieararchyDescriptor: Contains information about a class hierarchy.
3330 // Used during dynamic_cast to walk a class hierarchy. References a base
3331 // class array and the size of said array.
3332 //
3333 // BaseClassArray: Contains a list of classes in a hierarchy. BaseClassArray is
3334 // somewhat of a misnomer because the most derived class is also in the list
3335 // as well as multiple copies of virtual bases (if they occur multiple times
3336 // in the hiearchy.) The BaseClassArray contains one BaseClassDescriptor for
3337 // every path in the hierarchy, in pre-order depth first order. Note, we do
3338 // not declare a specific llvm type for BaseClassArray, it's merely an array
3339 // of BaseClassDescriptor pointers.
3340 //
3341 // BaseClassDescriptor: Contains information about a class in a class hierarchy.
3342 // BaseClassDescriptor is also somewhat of a misnomer for the same reason that
3343 // BaseClassArray is. It contains information about a class within a
3344 // hierarchy such as: is this base is ambiguous and what is its offset in the
3345 // vbtable. The names of the BaseClassDescriptors have all of their fields
3346 // mangled into them so they can be aggressively deduplicated by the linker.
3347 
3348 static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
3349  StringRef MangledName("\01??_7type_info@@6B@");
3350  if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
3351  return VTable;
3352  return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
3353  /*Constant=*/true,
3355  /*Initializer=*/nullptr, MangledName);
3356 }
3357 
3358 namespace {
3359 
3360 /// \brief A Helper struct that stores information about a class in a class
3361 /// hierarchy. The information stored in these structs struct is used during
3362 /// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
3363 // During RTTI creation, MSRTTIClasses are stored in a contiguous array with
3364 // implicit depth first pre-order tree connectivity. getFirstChild and
3365 // getNextSibling allow us to walk the tree efficiently.
3366 struct MSRTTIClass {
3367  enum {
3368  IsPrivateOnPath = 1 | 8,
3369  IsAmbiguous = 2,
3370  IsPrivate = 4,
3371  IsVirtual = 16,
3372  HasHierarchyDescriptor = 64
3373  };
3374  MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
3375  uint32_t initialize(const MSRTTIClass *Parent,
3376  const CXXBaseSpecifier *Specifier);
3377 
3378  MSRTTIClass *getFirstChild() { return this + 1; }
3379  static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
3380  return Child + 1 + Child->NumBases;
3381  }
3382 
3383  const CXXRecordDecl *RD, *VirtualRoot;
3384  uint32_t Flags, NumBases, OffsetInVBase;
3385 };
3386 
3387 /// \brief Recursively initialize the base class array.
3388 uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
3389  const CXXBaseSpecifier *Specifier) {
3390  Flags = HasHierarchyDescriptor;
3391  if (!Parent) {
3392  VirtualRoot = nullptr;
3393  OffsetInVBase = 0;
3394  } else {
3395  if (Specifier->getAccessSpecifier() != AS_public)
3396  Flags |= IsPrivate | IsPrivateOnPath;
3397  if (Specifier->isVirtual()) {
3398  Flags |= IsVirtual;
3399  VirtualRoot = RD;
3400  OffsetInVBase = 0;
3401  } else {
3402  if (Parent->Flags & IsPrivateOnPath)
3403  Flags |= IsPrivateOnPath;
3404  VirtualRoot = Parent->VirtualRoot;
3405  OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
3406  .getASTRecordLayout(Parent->RD).getBaseClassOffset(RD).getQuantity();
3407  }
3408  }
3409  NumBases = 0;
3410  MSRTTIClass *Child = getFirstChild();
3411  for (const CXXBaseSpecifier &Base : RD->bases()) {
3412  NumBases += Child->initialize(this, &Base) + 1;
3413  Child = getNextChild(Child);
3414  }
3415  return NumBases;
3416 }
3417 
3418 static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
3419  switch (Ty->getLinkage()) {
3420  case NoLinkage:
3421  case InternalLinkage:
3422  case UniqueExternalLinkage:
3424 
3425  case VisibleNoLinkage:
3426  case ModuleInternalLinkage:
3427  case ModuleLinkage:
3428  case ExternalLinkage:
3429  return llvm::GlobalValue::LinkOnceODRLinkage;
3430  }
3431  llvm_unreachable("Invalid linkage!");
3432 }
3433 
3434 /// \brief An ephemeral helper class for building MS RTTI types. It caches some
3435 /// calls to the module and information about the most derived class in a
3436 /// hierarchy.
3437 struct MSRTTIBuilder {
3438  enum {
3439  HasBranchingHierarchy = 1,
3440  HasVirtualBranchingHierarchy = 2,
3441  HasAmbiguousBases = 4
3442  };
3443 
3444  MSRTTIBuilder(MicrosoftCXXABI &ABI, const CXXRecordDecl *RD)
3445  : CGM(ABI.CGM), Context(CGM.getContext()),
3446  VMContext(CGM.getLLVMContext()), Module(CGM.getModule()), RD(RD),
3447  Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
3448  ABI(ABI) {}
3449 
3450  llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
3451  llvm::GlobalVariable *
3452  getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
3453  llvm::GlobalVariable *getClassHierarchyDescriptor();
3454  llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo &Info);
3455 
3456  CodeGenModule &CGM;
3458  llvm::LLVMContext &VMContext;
3459  llvm::Module &Module;
3460  const CXXRecordDecl *RD;
3461  llvm::GlobalVariable::LinkageTypes Linkage;
3462  MicrosoftCXXABI &ABI;
3463 };
3464 
3465 } // namespace
3466 
3467 /// \brief Recursively serializes a class hierarchy in pre-order depth first
3468 /// order.
3470  const CXXRecordDecl *RD) {
3471  Classes.push_back(MSRTTIClass(RD));
3472  for (const CXXBaseSpecifier &Base : RD->bases())
3473  serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
3474 }
3475 
3476 /// \brief Find ambiguity among base classes.
3477 static void
3479  llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
3480  llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
3481  llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
3482  for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
3483  if ((Class->Flags & MSRTTIClass::IsVirtual) &&
3484  !VirtualBases.insert(Class->RD).second) {
3485  Class = MSRTTIClass::getNextChild(Class);
3486  continue;
3487  }
3488  if (!UniqueBases.insert(Class->RD).second)
3489  AmbiguousBases.insert(Class->RD);
3490  Class++;
3491  }
3492  if (AmbiguousBases.empty())
3493  return;
3494  for (MSRTTIClass &Class : Classes)
3495  if (AmbiguousBases.count(Class.RD))
3496  Class.Flags |= MSRTTIClass::IsAmbiguous;
3497 }
3498 
3499 llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
3500  SmallString<256> MangledName;
3501  {
3502  llvm::raw_svector_ostream Out(MangledName);
3503  ABI.getMangleContext().mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
3504  }
3505 
3506  // Check to see if we've already declared this ClassHierarchyDescriptor.
3507  if (auto CHD = Module.getNamedGlobal(MangledName))
3508  return CHD;
3509 
3510  // Serialize the class hierarchy and initialize the CHD Fields.
3512  serializeClassHierarchy(Classes, RD);
3513  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
3514  detectAmbiguousBases(Classes);
3515  int Flags = 0;
3516  for (auto Class : Classes) {
3517  if (Class.RD->getNumBases() > 1)
3518  Flags |= HasBranchingHierarchy;
3519  // Note: cl.exe does not calculate "HasAmbiguousBases" correctly. We
3520  // believe the field isn't actually used.
3521  if (Class.Flags & MSRTTIClass::IsAmbiguous)
3522  Flags |= HasAmbiguousBases;
3523  }
3524  if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
3525  Flags |= HasVirtualBranchingHierarchy;
3526  // These gep indices are used to get the address of the first element of the
3527  // base class array.
3528  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
3529  llvm::ConstantInt::get(CGM.IntTy, 0)};
3530 
3531  // Forward-declare the class hierarchy descriptor
3532  auto Type = ABI.getClassHierarchyDescriptorType();
3533  auto CHD = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
3534  /*Initializer=*/nullptr,
3535  MangledName);
3536  if (CHD->isWeakForLinker())
3537  CHD->setComdat(CGM.getModule().getOrInsertComdat(CHD->getName()));
3538 
3539  auto *Bases = getBaseClassArray(Classes);
3540 
3541  // Initialize the base class ClassHierarchyDescriptor.
3542  llvm::Constant *Fields[] = {
3543  llvm::ConstantInt::get(CGM.IntTy, 0), // reserved by the runtime
3544  llvm::ConstantInt::get(CGM.IntTy, Flags),
3545  llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
3546  ABI.getImageRelativeConstant(llvm::ConstantExpr::getInBoundsGetElementPtr(
3547  Bases->getValueType(), Bases,
3548  llvm::ArrayRef<llvm::Value *>(GEPIndices))),
3549  };
3550  CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3551  return CHD;
3552 }
3553 
3554 llvm::GlobalVariable *
3555 MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
3556  SmallString<256> MangledName;
3557  {
3558  llvm::raw_svector_ostream Out(MangledName);
3559  ABI.getMangleContext().mangleCXXRTTIBaseClassArray(RD, Out);
3560  }
3561 
3562  // Forward-declare the base class array.
3563  // cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
3564  // mode) bytes of padding. We provide a pointer sized amount of padding by
3565  // adding +1 to Classes.size(). The sections have pointer alignment and are
3566  // marked pick-any so it shouldn't matter.
3567  llvm::Type *PtrType = ABI.getImageRelativeType(
3568  ABI.getBaseClassDescriptorType()->getPointerTo());
3569  auto *ArrType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
3570  auto *BCA =
3571  new llvm::GlobalVariable(Module, ArrType,
3572  /*Constant=*/true, Linkage,
3573  /*Initializer=*/nullptr, MangledName);
3574  if (BCA->isWeakForLinker())
3575  BCA->setComdat(CGM.getModule().getOrInsertComdat(BCA->getName()));
3576 
3577  // Initialize the BaseClassArray.
3578  SmallVector<llvm::Constant *, 8> BaseClassArrayData;
3579  for (MSRTTIClass &Class : Classes)
3580  BaseClassArrayData.push_back(
3581  ABI.getImageRelativeConstant(getBaseClassDescriptor(Class)));
3582  BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
3583  BCA->setInitializer(llvm::ConstantArray::get(ArrType, BaseClassArrayData));
3584  return BCA;
3585 }
3586 
3587 llvm::GlobalVariable *
3588 MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
3589  // Compute the fields for the BaseClassDescriptor. They are computed up front
3590  // because they are mangled into the name of the object.
3591  uint32_t OffsetInVBTable = 0;
3592  int32_t VBPtrOffset = -1;
3593  if (Class.VirtualRoot) {
3594  auto &VTableContext = CGM.getMicrosoftVTableContext();
3595  OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
3596  VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
3597  }
3598 
3599  SmallString<256> MangledName;
3600  {
3601  llvm::raw_svector_ostream Out(MangledName);
3602  ABI.getMangleContext().mangleCXXRTTIBaseClassDescriptor(
3603  Class.RD, Class.OffsetInVBase, VBPtrOffset, OffsetInVBTable,
3604  Class.Flags, Out);
3605  }
3606 
3607  // Check to see if we've already declared this object.
3608  if (auto BCD = Module.getNamedGlobal(MangledName))
3609  return BCD;
3610 
3611  // Forward-declare the base class descriptor.
3612  auto Type = ABI.getBaseClassDescriptorType();
3613  auto BCD =
3614  new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
3615  /*Initializer=*/nullptr, MangledName);
3616  if (BCD->isWeakForLinker())
3617  BCD->setComdat(CGM.getModule().getOrInsertComdat(BCD->getName()));
3618 
3619  // Initialize the BaseClassDescriptor.
3620  llvm::Constant *Fields[] = {
3621  ABI.getImageRelativeConstant(
3622  ABI.getAddrOfRTTIDescriptor(Context.getTypeDeclType(Class.RD))),
3623  llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
3624  llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
3625  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
3626  llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
3627  llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
3628  ABI.getImageRelativeConstant(
3629  MSRTTIBuilder(ABI, Class.RD).getClassHierarchyDescriptor()),
3630  };
3631  BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3632  return BCD;
3633 }
3634 
3635 llvm::GlobalVariable *
3636 MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo &Info) {
3637  SmallString<256> MangledName;
3638  {
3639  llvm::raw_svector_ostream Out(MangledName);
3640  ABI.getMangleContext().mangleCXXRTTICompleteObjectLocator(RD, Info.MangledPath, Out);
3641  }
3642 
3643  // Check to see if we've already computed this complete object locator.
3644  if (auto COL = Module.getNamedGlobal(MangledName))
3645  return COL;
3646 
3647  // Compute the fields of the complete object locator.
3648  int OffsetToTop = Info.FullOffsetInMDC.getQuantity();
3649  int VFPtrOffset = 0;
3650  // The offset includes the vtordisp if one exists.
3651  if (const CXXRecordDecl *VBase = Info.getVBaseWithVPtr())
3652  if (Context.getASTRecordLayout(RD)
3653  .getVBaseOffsetsMap()
3654  .find(VBase)
3655  ->second.hasVtorDisp())
3656  VFPtrOffset = Info.NonVirtualOffset.getQuantity() + 4;
3657 
3658  // Forward-declare the complete object locator.
3659  llvm::StructType *Type = ABI.getCompleteObjectLocatorType();
3660  auto COL = new llvm::GlobalVariable(Module, Type, /*Constant=*/true, Linkage,
3661  /*Initializer=*/nullptr, MangledName);
3662 
3663  // Initialize the CompleteObjectLocator.
3664  llvm::Constant *Fields[] = {
3665  llvm::ConstantInt::get(CGM.IntTy, ABI.isImageRelative()),
3666  llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
3667  llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
3668  ABI.getImageRelativeConstant(
3669  CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(RD))),
3670  ABI.getImageRelativeConstant(getClassHierarchyDescriptor()),
3671  ABI.getImageRelativeConstant(COL),
3672  };
3673  llvm::ArrayRef<llvm::Constant *> FieldsRef(Fields);
3674  if (!ABI.isImageRelative())
3675  FieldsRef = FieldsRef.drop_back();
3676  COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
3677  if (COL->isWeakForLinker())
3678  COL->setComdat(CGM.getModule().getOrInsertComdat(COL->getName()));
3679  return COL;
3680 }
3681 
3683  bool &IsConst, bool &IsVolatile,
3684  bool &IsUnaligned) {
3685  T = Context.getExceptionObjectType(T);
3686 
3687  // C++14 [except.handle]p3:
3688  // A handler is a match for an exception object of type E if [...]
3689  // - the handler is of type cv T or const T& where T is a pointer type and
3690  // E is a pointer type that can be converted to T by [...]
3691  // - a qualification conversion
3692  IsConst = false;
3693  IsVolatile = false;
3694  IsUnaligned = false;
3695  QualType PointeeType = T->getPointeeType();
3696  if (!PointeeType.isNull()) {
3697  IsConst = PointeeType.isConstQualified();
3698  IsVolatile = PointeeType.isVolatileQualified();
3699  IsUnaligned = PointeeType.getQualifiers().hasUnaligned();
3700  }
3701 
3702  // Member pointer types like "const int A::*" are represented by having RTTI
3703  // for "int A::*" and separately storing the const qualifier.
3704  if (const auto *MPTy = T->getAs<MemberPointerType>())
3705  T = Context.getMemberPointerType(PointeeType.getUnqualifiedType(),
3706  MPTy->getClass());
3707 
3708  // Pointer types like "const int * const *" are represented by having RTTI
3709  // for "const int **" and separately storing the const qualifier.
3710  if (T->isPointerType())
3711  T = Context.getPointerType(PointeeType.getUnqualifiedType());
3712 
3713  return T;
3714 }
3715 
3717 MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
3718  QualType CatchHandlerType) {
3719  // TypeDescriptors for exceptions never have qualified pointer types,
3720  // qualifiers are stored separately in order to support qualification
3721  // conversions.
3722  bool IsConst, IsVolatile, IsUnaligned;
3723  Type =
3724  decomposeTypeForEH(getContext(), Type, IsConst, IsVolatile, IsUnaligned);
3725 
3726  bool IsReference = CatchHandlerType->isReferenceType();
3727 
3728  uint32_t Flags = 0;
3729  if (IsConst)
3730  Flags |= 1;
3731  if (IsVolatile)
3732  Flags |= 2;
3733  if (IsUnaligned)
3734  Flags |= 4;
3735  if (IsReference)
3736  Flags |= 8;
3737 
3738  return CatchTypeInfo{getAddrOfRTTIDescriptor(Type)->stripPointerCasts(),
3739  Flags};
3740 }
3741 
3742 /// \brief Gets a TypeDescriptor. Returns a llvm::Constant * rather than a
3743 /// llvm::GlobalVariable * because different type descriptors have different
3744 /// types, and need to be abstracted. They are abstracting by casting the
3745 /// address to an Int8PtrTy.
3746 llvm::Constant *MicrosoftCXXABI::getAddrOfRTTIDescriptor(QualType Type) {
3747  SmallString<256> MangledName;
3748  {
3749  llvm::raw_svector_ostream Out(MangledName);
3750  getMangleContext().mangleCXXRTTI(Type, Out);
3751  }
3752 
3753  // Check to see if we've already declared this TypeDescriptor.
3754  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
3755  return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
3756 
3757  // Note for the future: If we would ever like to do deferred emission of
3758  // RTTI, check if emitting vtables opportunistically need any adjustment.
3759 
3760  // Compute the fields for the TypeDescriptor.
3761  SmallString<256> TypeInfoString;
3762  {
3763  llvm::raw_svector_ostream Out(TypeInfoString);
3764  getMangleContext().mangleCXXRTTIName(Type, Out);
3765  }
3766 
3767  // Declare and initialize the TypeDescriptor.
3768  llvm::Constant *Fields[] = {
3769  getTypeInfoVTable(CGM), // VFPtr
3770  llvm::ConstantPointerNull::get(CGM.Int8PtrTy), // Runtime data
3771  llvm::ConstantDataArray::getString(CGM.getLLVMContext(), TypeInfoString)};
3772  llvm::StructType *TypeDescriptorType =
3773  getTypeDescriptorType(TypeInfoString);
3774  auto *Var = new llvm::GlobalVariable(
3775  CGM.getModule(), TypeDescriptorType, /*Constant=*/false,
3776  getLinkageForRTTI(Type),
3777  llvm::ConstantStruct::get(TypeDescriptorType, Fields),
3778  MangledName);
3779  if (Var->isWeakForLinker())
3780  Var->setComdat(CGM.getModule().getOrInsertComdat(Var->getName()));
3781  return llvm::ConstantExpr::getBitCast(Var, CGM.Int8PtrTy);
3782 }
3783 
3784 /// \brief Gets or a creates a Microsoft CompleteObjectLocator.
3785 llvm::GlobalVariable *
3786 MicrosoftCXXABI::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
3787  const VPtrInfo &Info) {
3788  return MSRTTIBuilder(*this, RD).getCompleteObjectLocator(Info);
3789 }
3790 
3792  const CXXConstructorDecl *ctor,
3793  StructorType ctorType) {
3794  // There are no constructor variants, always emit the complete destructor.
3795  llvm::Function *Fn = CGM.codegenCXXStructor(ctor, StructorType::Complete);
3796  CGM.maybeSetTrivialComdat(*ctor, *Fn);
3797 }
3798 
3799 static void emitCXXDestructor(CodeGenModule &CGM, const CXXDestructorDecl *dtor,
3800  StructorType dtorType) {
3801  // The complete destructor is equivalent to the base destructor for
3802  // classes with no virtual bases, so try to emit it as an alias.
3803  if (!dtor->getParent()->getNumVBases() &&
3804  (dtorType == StructorType::Complete || dtorType == StructorType::Base)) {
3805  bool ProducedAlias = !CGM.TryEmitDefinitionAsAlias(
3806  GlobalDecl(dtor, Dtor_Complete), GlobalDecl(dtor, Dtor_Base), true);
3807  if (ProducedAlias) {
3808  if (dtorType == StructorType::Complete)
3809  return;
3810  if (dtor->isVirtual())
3812  }
3813  }
3814 
3815  // The base destructor is equivalent to the base destructor of its
3816  // base class if there is exactly one non-virtual base class with a
3817  // non-trivial destructor, there are no fields with a non-trivial
3818  // destructor, and the body of the destructor is trivial.
3819  if (dtorType == StructorType::Base && !CGM.TryEmitBaseDestructorAsAlias(dtor))
3820  return;
3821 
3822  llvm::Function *Fn = CGM.codegenCXXStructor(dtor, dtorType);
3823  if (Fn->isWeakForLinker())
3824  Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName()));
3825 }
3826 
3827 void MicrosoftCXXABI::emitCXXStructor(const CXXMethodDecl *MD,
3828  StructorType Type) {
3829  if (auto *CD = dyn_cast<CXXConstructorDecl>(MD)) {
3830  emitCXXConstructor(CGM, CD, Type);
3831  return;
3832  }
3833  emitCXXDestructor(CGM, cast<CXXDestructorDecl>(MD), Type);
3834 }
3835 
3836 llvm::Function *
3837 MicrosoftCXXABI::getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
3838  CXXCtorType CT) {
3839  assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure);
3840 
3841  // Calculate the mangled name.
3842  SmallString<256> ThunkName;
3843  llvm::raw_svector_ostream Out(ThunkName);
3844  getMangleContext().mangleCXXCtor(CD, CT, Out);
3845 
3846  // If the thunk has been generated previously, just return it.
3847  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
3848  return cast<llvm::Function>(GV);
3849 
3850  // Create the llvm::Function.
3851  const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeMSCtorClosure(CD, CT);
3852  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
3853  const CXXRecordDecl *RD = CD->getParent();
3854  QualType RecordTy = getContext().getRecordType(RD);
3855  llvm::Function *ThunkFn = llvm::Function::Create(
3856  ThunkTy, getLinkageForRTTI(RecordTy), ThunkName.str(), &CGM.getModule());
3857  ThunkFn->setCallingConv(static_cast<llvm::CallingConv::ID>(
3858  FnInfo.getEffectiveCallingConvention()));
3859  if (ThunkFn->isWeakForLinker())
3860  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
3861  bool IsCopy = CT == Ctor_CopyingClosure;
3862 
3863  // Start codegen.
3864  CodeGenFunction CGF(CGM);
3865  CGF.CurGD = GlobalDecl(CD, Ctor_Complete);
3866 
3867  // Build FunctionArgs.
3868  FunctionArgList FunctionArgs;
3869 
3870  // A constructor always starts with a 'this' pointer as its first argument.
3871  buildThisParam(CGF, FunctionArgs);
3872 
3873  // Following the 'this' pointer is a reference to the source object that we
3874  // are copying from.
3875  ImplicitParamDecl SrcParam(
3876  getContext(), /*DC=*/nullptr, SourceLocation(),
3877  &getContext().Idents.get("src"),
3878  getContext().getLValueReferenceType(RecordTy,
3879  /*SpelledAsLValue=*/true),
3881  if (IsCopy)
3882  FunctionArgs.push_back(&SrcParam);
3883 
3884  // Constructors for classes which utilize virtual bases have an additional
3885  // parameter which indicates whether or not it is being delegated to by a more
3886  // derived constructor.
3887  ImplicitParamDecl IsMostDerived(getContext(), /*DC=*/nullptr,
3888  SourceLocation(),
3889  &getContext().Idents.get("is_most_derived"),
3890  getContext().IntTy, ImplicitParamDecl::Other);
3891  // Only add the parameter to the list if thie class has virtual bases.
3892  if (RD->getNumVBases() > 0)
3893  FunctionArgs.push_back(&IsMostDerived);
3894 
3895  // Start defining the function.
3896  auto NL = ApplyDebugLocation::CreateEmpty(CGF);
3897  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
3898  FunctionArgs, CD->getLocation(), SourceLocation());
3899  // Create a scope with an artificial location for the body of this function.
3900  auto AL = ApplyDebugLocation::CreateArtificial(CGF);
3901  EmitThisParam(CGF);
3902  llvm::Value *This = getThisValue(CGF);
3903 
3904  llvm::Value *SrcVal =
3905  IsCopy ? CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(&SrcParam), "src")
3906  : nullptr;
3907 
3908  CallArgList Args;
3909 
3910  // Push the this ptr.
3911  Args.add(RValue::get(This), CD->getThisType(getContext()));
3912 
3913  // Push the src ptr.
3914  if (SrcVal)
3915  Args.add(RValue::get(SrcVal), SrcParam.getType());
3916 
3917  // Add the rest of the default arguments.
3919  ArrayRef<ParmVarDecl *> params = CD->parameters().drop_front(IsCopy ? 1 : 0);
3920  for (const ParmVarDecl *PD : params) {
3921  assert(PD->hasDefaultArg() && "ctor closure lacks default args");
3922  ArgVec.push_back(PD->getDefaultArg());
3923  }
3924 
3925  CodeGenFunction::RunCleanupsScope Cleanups(CGF);
3926 
3927  const auto *FPT = CD->getType()->castAs<FunctionProtoType>();
3928  CGF.EmitCallArgs(Args, FPT, llvm::makeArrayRef(ArgVec), CD, IsCopy ? 1 : 0);
3929 
3930  // Insert any ABI-specific implicit constructor arguments.
3931  AddedStructorArgs ExtraArgs =
3932  addImplicitConstructorArgs(CGF, CD, Ctor_Complete,
3933  /*ForVirtualBase=*/false,
3934  /*Delegating=*/false, Args);
3935  // Call the destructor with our arguments.
3936  llvm::Constant *CalleePtr =
3938  CGCallee Callee = CGCallee::forDirect(CalleePtr, CD);
3939  const CGFunctionInfo &CalleeInfo = CGM.getTypes().arrangeCXXConstructorCall(
3940  Args, CD, Ctor_Complete, ExtraArgs.Prefix, ExtraArgs.Suffix);
3941  CGF.EmitCall(CalleeInfo, Callee, ReturnValueSlot(), Args);
3942 
3943  Cleanups.ForceCleanup();
3944 
3945  // Emit the ret instruction, remove any temporary instructions created for the
3946  // aid of CodeGen.
3948 
3949  return ThunkFn;
3950 }
3951 
3952 llvm::Constant *MicrosoftCXXABI::getCatchableType(QualType T,
3953  uint32_t NVOffset,
3954  int32_t VBPtrOffset,
3955  uint32_t VBIndex) {
3956  assert(!T->isReferenceType());
3957 
3958  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
3959  const CXXConstructorDecl *CD =
3960  RD ? CGM.getContext().getCopyConstructorForExceptionObject(RD) : nullptr;
3962  if (CD)
3963  if (!hasDefaultCXXMethodCC(getContext(), CD) || CD->getNumParams() != 1)
3964  CT = Ctor_CopyingClosure;
3965 
3966  uint32_t Size = getContext().getTypeSizeInChars(T).getQuantity();
3967  SmallString<256> MangledName;
3968  {
3969  llvm::raw_svector_ostream Out(MangledName);
3970  getMangleContext().mangleCXXCatchableType(T, CD, CT, Size, NVOffset,
3971  VBPtrOffset, VBIndex, Out);
3972  }
3973  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
3974  return getImageRelativeConstant(GV);
3975 
3976  // The TypeDescriptor is used by the runtime to determine if a catch handler
3977  // is appropriate for the exception object.
3978  llvm::Constant *TD = getImageRelativeConstant(getAddrOfRTTIDescriptor(T));
3979 
3980  // The runtime is responsible for calling the copy constructor if the
3981  // exception is caught by value.
3982  llvm::Constant *CopyCtor;
3983  if (CD) {
3984  if (CT == Ctor_CopyingClosure)
3985  CopyCtor = getAddrOfCXXCtorClosure(CD, Ctor_CopyingClosure);
3986  else
3987  CopyCtor = CGM.getAddrOfCXXStructor(CD, StructorType::Complete);
3988 
3989  CopyCtor = llvm::ConstantExpr::getBitCast(CopyCtor, CGM.Int8PtrTy);
3990  } else {
3991  CopyCtor = llvm::Constant::getNullValue(CGM.Int8PtrTy);
3992  }
3993  CopyCtor = getImageRelativeConstant(CopyCtor);
3994 
3995  bool IsScalar = !RD;
3996  bool HasVirtualBases = false;
3997  bool IsStdBadAlloc = false; // std::bad_alloc is special for some reason.
3998  QualType PointeeType = T;
3999  if (T->isPointerType())
4000  PointeeType = T->getPointeeType();
4001  if (const CXXRecordDecl *RD = PointeeType->getAsCXXRecordDecl()) {
4002  HasVirtualBases = RD->getNumVBases() > 0;
4003  if (IdentifierInfo *II = RD->getIdentifier())
4004  IsStdBadAlloc = II->isStr("bad_alloc") && RD->isInStdNamespace();
4005  }
4006 
4007  // Encode the relevant CatchableType properties into the Flags bitfield.
4008  // FIXME: Figure out how bits 2 or 8 can get set.
4009  uint32_t Flags = 0;
4010  if (IsScalar)
4011  Flags |= 1;
4012  if (HasVirtualBases)
4013  Flags |= 4;
4014  if (IsStdBadAlloc)
4015  Flags |= 16;
4016 
4017  llvm::Constant *Fields[] = {
4018  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4019  TD, // TypeDescriptor
4020  llvm::ConstantInt::get(CGM.IntTy, NVOffset), // NonVirtualAdjustment
4021  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset), // OffsetToVBPtr
4022  llvm::ConstantInt::get(CGM.IntTy, VBIndex), // VBTableIndex
4023  llvm::ConstantInt::get(CGM.IntTy, Size), // Size
4024  CopyCtor // CopyCtor
4025  };
4026  llvm::StructType *CTType = getCatchableTypeType();
4027  auto *GV = new llvm::GlobalVariable(
4028  CGM.getModule(), CTType, /*Constant=*/true, getLinkageForRTTI(T),
4029  llvm::ConstantStruct::get(CTType, Fields), MangledName);
4030  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4031  GV->setSection(".xdata");
4032  if (GV->isWeakForLinker())
4033  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4034  return getImageRelativeConstant(GV);
4035 }
4036 
4037 llvm::GlobalVariable *MicrosoftCXXABI::getCatchableTypeArray(QualType T) {
4038  assert(!T->isReferenceType());
4039 
4040  // See if we've already generated a CatchableTypeArray for this type before.
4041  llvm::GlobalVariable *&CTA = CatchableTypeArrays[T];
4042  if (CTA)
4043  return CTA;
4044 
4045  // Ensure that we don't have duplicate entries in our CatchableTypeArray by
4046  // using a SmallSetVector. Duplicates may arise due to virtual bases
4047  // occurring more than once in the hierarchy.
4049 
4050  // C++14 [except.handle]p3:
4051  // A handler is a match for an exception object of type E if [...]
4052  // - the handler is of type cv T or cv T& and T is an unambiguous public
4053  // base class of E, or
4054  // - the handler is of type cv T or const T& where T is a pointer type and
4055  // E is a pointer type that can be converted to T by [...]
4056  // - a standard pointer conversion (4.10) not involving conversions to
4057  // pointers to private or protected or ambiguous classes
4058  const CXXRecordDecl *MostDerivedClass = nullptr;
4059  bool IsPointer = T->isPointerType();
4060  if (IsPointer)
4061  MostDerivedClass = T->getPointeeType()->getAsCXXRecordDecl();
4062  else
4063  MostDerivedClass = T->getAsCXXRecordDecl();
4064 
4065  // Collect all the unambiguous public bases of the MostDerivedClass.
4066  if (MostDerivedClass) {
4067  const ASTContext &Context = getContext();
4068  const ASTRecordLayout &MostDerivedLayout =
4069  Context.getASTRecordLayout(MostDerivedClass);
4070  MicrosoftVTableContext &VTableContext = CGM.getMicrosoftVTableContext();
4072  serializeClassHierarchy(Classes, MostDerivedClass);
4073  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
4074  detectAmbiguousBases(Classes);
4075  for (const MSRTTIClass &Class : Classes) {
4076  // Skip any ambiguous or private bases.
4077  if (Class.Flags &
4078  (MSRTTIClass::IsPrivateOnPath | MSRTTIClass::IsAmbiguous))
4079  continue;
4080  // Write down how to convert from a derived pointer to a base pointer.
4081  uint32_t OffsetInVBTable = 0;
4082  int32_t VBPtrOffset = -1;
4083  if (Class.VirtualRoot) {
4084  OffsetInVBTable =
4085  VTableContext.getVBTableIndex(MostDerivedClass, Class.VirtualRoot)*4;
4086  VBPtrOffset = MostDerivedLayout.getVBPtrOffset().getQuantity();
4087  }
4088 
4089  // Turn our record back into a pointer if the exception object is a
4090  // pointer.
4091  QualType RTTITy = QualType(Class.RD->getTypeForDecl(), 0);
4092  if (IsPointer)
4093  RTTITy = Context.getPointerType(RTTITy);
4094  CatchableTypes.insert(getCatchableType(RTTITy, Class.OffsetInVBase,
4095  VBPtrOffset, OffsetInVBTable));
4096  }
4097  }
4098 
4099  // C++14 [except.handle]p3:
4100  // A handler is a match for an exception object of type E if
4101  // - The handler is of type cv T or cv T& and E and T are the same type
4102  // (ignoring the top-level cv-qualifiers)
4103  CatchableTypes.insert(getCatchableType(T));
4104 
4105  // C++14 [except.handle]p3:
4106  // A handler is a match for an exception object of type E if
4107  // - the handler is of type cv T or const T& where T is a pointer type and
4108  // E is a pointer type that can be converted to T by [...]
4109  // - a standard pointer conversion (4.10) not involving conversions to
4110  // pointers to private or protected or ambiguous classes
4111  //
4112  // C++14 [conv.ptr]p2:
4113  // A prvalue of type "pointer to cv T," where T is an object type, can be
4114  // converted to a prvalue of type "pointer to cv void".
4115  if (IsPointer && T->getPointeeType()->isObjectType())
4116  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4117 
4118  // C++14 [except.handle]p3:
4119  // A handler is a match for an exception object of type E if [...]
4120  // - the handler is of type cv T or const T& where T is a pointer or
4121  // pointer to member type and E is std::nullptr_t.
4122  //
4123  // We cannot possibly list all possible pointer types here, making this
4124  // implementation incompatible with the standard. However, MSVC includes an
4125  // entry for pointer-to-void in this case. Let's do the same.
4126  if (T->isNullPtrType())
4127  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4128 
4129  uint32_t NumEntries = CatchableTypes.size();
4130  llvm::Type *CTType =
4131  getImageRelativeType(getCatchableTypeType()->getPointerTo());
4132  llvm::ArrayType *AT = llvm::ArrayType::get(CTType, NumEntries);
4133  llvm::StructType *CTAType = getCatchableTypeArrayType(NumEntries);
4134  llvm::Constant *Fields[] = {
4135  llvm::ConstantInt::get(CGM.IntTy, NumEntries), // NumEntries
4136  llvm::ConstantArray::get(
4137  AT, llvm::makeArrayRef(CatchableTypes.begin(),
4138  CatchableTypes.end())) // CatchableTypes
4139  };
4140  SmallString<256> MangledName;
4141  {
4142  llvm::raw_svector_ostream Out(MangledName);
4143  getMangleContext().mangleCXXCatchableTypeArray(T, NumEntries, Out);
4144  }
4145  CTA = new llvm::GlobalVariable(
4146  CGM.getModule(), CTAType, /*Constant=*/true, getLinkageForRTTI(T),
4147  llvm::ConstantStruct::get(CTAType, Fields), MangledName);
4148  CTA->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4149  CTA->setSection(".xdata");
4150  if (CTA->isWeakForLinker())
4151  CTA->setComdat(CGM.getModule().getOrInsertComdat(CTA->getName()));
4152  return CTA;
4153 }
4154 
4155 llvm::GlobalVariable *MicrosoftCXXABI::getThrowInfo(QualType T) {
4156  bool IsConst, IsVolatile, IsUnaligned;
4157  T = decomposeTypeForEH(getContext(), T, IsConst, IsVolatile, IsUnaligned);
4158 
4159  // The CatchableTypeArray enumerates the various (CV-unqualified) types that
4160  // the exception object may be caught as.
4161  llvm::GlobalVariable *CTA = getCatchableTypeArray(T);
4162  // The first field in a CatchableTypeArray is the number of CatchableTypes.
4163  // This is used as a component of the mangled name which means that we need to
4164  // know what it is in order to see if we have previously generated the
4165  // ThrowInfo.
4166  uint32_t NumEntries =
4167  cast<llvm::ConstantInt>(CTA->getInitializer()->getAggregateElement(0U))
4168  ->getLimitedValue();
4169 
4170  SmallString<256> MangledName;
4171  {
4172  llvm::raw_svector_ostream Out(MangledName);
4173  getMangleContext().mangleCXXThrowInfo(T, IsConst, IsVolatile, IsUnaligned,
4174  NumEntries, Out);
4175  }
4176 
4177  // Reuse a previously generated ThrowInfo if we have generated an appropriate
4178  // one before.
4179  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
4180  return GV;
4181 
4182  // The RTTI TypeDescriptor uses an unqualified type but catch clauses must
4183  // be at least as CV qualified. Encode this requirement into the Flags
4184  // bitfield.
4185  uint32_t Flags = 0;
4186  if (IsConst)
4187  Flags |= 1;
4188  if (IsVolatile)
4189  Flags |= 2;
4190  if (IsUnaligned)
4191  Flags |= 4;
4192 
4193  // The cleanup-function (a destructor) must be called when the exception
4194  // object's lifetime ends.
4195  llvm::Constant *CleanupFn = llvm::Constant::getNullValue(CGM.Int8PtrTy);
4196  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4197  if (CXXDestructorDecl *DtorD = RD->getDestructor())
4198  if (!DtorD->isTrivial())
4199  CleanupFn = llvm::ConstantExpr::getBitCast(
4201  CGM.Int8PtrTy);
4202  // This is unused as far as we can tell, initialize it to null.
4203  llvm::Constant *ForwardCompat =
4204  getImageRelativeConstant(llvm::Constant::getNullValue(CGM.Int8PtrTy));
4205  llvm::Constant *PointerToCatchableTypes = getImageRelativeConstant(
4206  llvm::ConstantExpr::getBitCast(CTA, CGM.Int8PtrTy));
4207  llvm::StructType *TIType = getThrowInfoType();
4208  llvm::Constant *Fields[] = {
4209  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4210  getImageRelativeConstant(CleanupFn), // CleanupFn
4211  ForwardCompat, // ForwardCompat
4212  PointerToCatchableTypes // CatchableTypeArray
4213  };
4214  auto *GV = new llvm::GlobalVariable(
4215  CGM.getModule(), TIType, /*Constant=*/true, getLinkageForRTTI(T),
4216  llvm::ConstantStruct::get(TIType, Fields), StringRef(MangledName));
4217  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4218  GV->setSection(".xdata");
4219  if (GV->isWeakForLinker())
4220  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4221  return GV;
4222 }
4223 
4224 void MicrosoftCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
4225  const Expr *SubExpr = E->getSubExpr();
4226  QualType ThrowType = SubExpr->getType();
4227  // The exception object lives on the stack and it's address is passed to the
4228  // runtime function.
4229  Address AI = CGF.CreateMemTemp(ThrowType);
4230  CGF.EmitAnyExprToMem(SubExpr, AI, ThrowType.getQualifiers(),
4231  /*IsInit=*/true);
4232 
4233  // The so-called ThrowInfo is used to describe how the exception object may be
4234  // caught.
4235  llvm::GlobalVariable *TI = getThrowInfo(ThrowType);
4236 
4237  // Call into the runtime to throw the exception.
4238  llvm::Value *Args[] = {
4239  CGF.Builder.CreateBitCast(AI.getPointer(), CGM.Int8PtrTy),
4240  TI
4241  };
4243 }
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:281
bool isNegative() const
isNegative - Test whether the quantity is less than zero.
Definition: CharUnits.h:125
static QualType decomposeTypeForEH(ASTContext &Context, QualType T, bool &IsConst, bool &IsVolatile, bool &IsUnaligned)
CastKind getCastKind() const
Definition: Expr.h:2749
llvm::IntegerType * IntTy
int
bool isVariadic() const
Definition: Type.h:3442
void GenerateCXXGlobalInitFunc(llvm::Function *Fn, ArrayRef< llvm::Function * > CXXThreadLocals, Address Guard=Address::invalid())
GenerateCXXGlobalInitFunc - Generates code for initializing global variables.
Definition: CGDeclCXX.cpp:523
struct clang::ThisAdjustment::VirtualAdjustment::@119 Microsoft
const internal::VariadicDynCastAllOfMatcher< Stmt, Expr > expr
Matches expressions.
Definition: ASTMatchers.h:1510
void setSRetAfterThis(bool AfterThis)
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:61
bool isNullPtrType() const
Definition: Type.h:5919
Parameter for captured context.
Definition: Decl.h:1395
Complete object ctor.
Definition: ABI.h:26
static void emitGlobalDtorWithTLRegDtor(CodeGenFunction &CGF, const VarDecl &VD, llvm::Constant *Dtor, llvm::Constant *Addr)
A (possibly-)qualified type.
Definition: Type.h:616
bool isVirtual() const
Determines whether the base class is a virtual base class (or not).
Definition: DeclCXX.h:212
static llvm::Constant * getInitThreadFooterFn(CodeGenModule &CGM)
llvm::DenseMap< const CXXRecordDecl *, VBaseInfo > VBaseOffsetsMapTy
Definition: RecordLayout.h:57
base_class_range bases()
Definition: DeclCXX.h:737
llvm::Type * ConvertTypeForMem(QualType T)
CanQualType getReturnType() const
uint32_t VBPtrOffset
The offset (in bytes) of the vbptr, relative to the beginning of the derived class.
Definition: ABI.h:61
Internal linkage according to the Modules TS, but can be referred to from other translation units ind...
Definition: Linkage.h:51
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1054
llvm::Module & getModule() const
llvm::LLVMContext & getLLVMContext()
static void detectAmbiguousBases(SmallVectorImpl< MSRTTIClass > &Classes)
Find ambiguity among base classes.
MSInheritanceAttr::Spelling getMSInheritanceModel() const
Returns the inheritance model used for this record.
The standard implementation of ConstantInitBuilder used in Clang.
CanQualType getSizeType() const
Return the unique type for "size_t" (C99 7.17), defined in <stddef.h>.
bool isGlobalDelete() const
Definition: ExprCXX.h:2025
No linkage, which means that the entity is unique and can only be referred to from within its scope...
Definition: Linkage.h:28
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:179
ctor_range ctors() const
Definition: DeclCXX.h:798
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:242
const Decl * CurCodeDecl
CurCodeDecl - This is the inner-most code context, which includes blocks.
bool hasNonTrivialDestructor() const
Determine whether this class has a non-trivial destructor (C++ [class.dtor]p3)
Definition: DeclCXX.h:1356
bool hasDefinition() const
Definition: DeclCXX.h:702
QualType getPointeeType() const
Definition: Type.h:2461
The base class of the type hierarchy.
Definition: Type.h:1303
int64_t NonVirtual
The non-virtual adjustment from the derived object to its nearest virtual base.
Definition: ABI.h:111
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1205
bool isCopyConstructor(unsigned &TypeQuals) const
Whether this constructor is a copy constructor (C++ [class.copy]p2, which can be used to copy the cla...
Definition: DeclCXX.cpp:2018
CharUnits getVBaseClassOffset(const CXXRecordDecl *VBase) const
getVBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:227
const NestedNameSpecifier * Specifier
bool isFuncTypeConvertible(const FunctionType *FT)
isFuncTypeConvertible - Utility to check whether a function type can be converted to an LLVM type (i...
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:2329
bool TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D)
Try to emit a base destructor as an alias to its primary base-class destructor.
Definition: CGCXX.cpp:34
Default closure variant of a ctor.
Definition: ABI.h:30
const CXXBaseSpecifier *const * path_const_iterator
Definition: Expr.h:2766
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
VarDecl - An instance of this class is created to represent a variable declaration or definition...
Definition: Decl.h:758
TLSKind getTLSKind() const
Definition: Decl.cpp:1876
static llvm::Constant * getInitThreadHeaderFn(CodeGenModule &CGM)
A this pointer adjustment.
Definition: ABI.h:108
QualType getThisType(ASTContext &C) const
Returns the type of the this pointer.
Definition: DeclCXX.cpp:1845
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:227
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:928
static llvm::Constant * getInitThreadAbortFn(CodeGenModule &CGM)
ParmVarDecl - Represents a parameter to a function.
Definition: Decl.h:1434
Linkage
Describes the different kinds of linkage (C++ [basic.link], C99 6.2.2) that an entity may have...
Definition: Linkage.h:25
bool hasTrivialCopyConstructor() const
Determine whether this class has a trivial copy constructor (C++ [class.copy]p6, C++11 [class...
Definition: DeclCXX.h:1294
GlobalDecl getCanonicalDecl() const
Definition: GlobalDecl.h:54
int32_t VBOffsetOffset
The offset (in bytes) of the vbase offset in the vbtable.
Definition: ABI.h:132
One of these records is kept for each identifier that is lexed.
ArrayRef< const CXXRecordDecl * > getMemberPointerPath() const
Definition: APValue.cpp:629
const CXXRecordDecl * getVBaseWithVPtr() const
The vptr is stored inside the non-virtual component of this virtual base.
bool hasAttr() const
Definition: DeclBase.h:521
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:128
bool isReferenceType() const
Definition: Type.h:5721
llvm::Constant * getAddrOfCXXStructor(const CXXMethodDecl *MD, StructorType Type, 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.
Definition: CGCXX.cpp:240
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:2683
StructorType getFromDtorType(CXXDtorType T)
Definition: CodeGenTypes.h:104
llvm::CallInst * EmitRuntimeCall(llvm::Value *callee, const Twine &name="")
CXXMethodDecl * getCanonicalDecl() override
Retrieves the "canonical" declaration of the given declaration.
Definition: DeclCXX.h:1984
ABIArgInfo classifyReturnType(CodeGenModule &CGM, CanQualType type)
Classify the rules for how to return a particular type.
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:81
A return adjustment.
Definition: ABI.h:42
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
Expr * getSubExpr()
Definition: Expr.h:2753
llvm::Function * codegenCXXStructor(const CXXMethodDecl *MD, StructorType Type)
Definition: CGCXX.cpp:215
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:1295
const Decl * getDecl() const
Definition: GlobalDecl.h:62
Describes a module or submodule.
Definition: Module.h:57
IdentifierTable & Idents
Definition: ASTContext.h:513
static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF)
Apply TemporaryLocation if it is valid.
Definition: CGDebugInfo.h:648
unsigned getEffectiveCallingConvention() const
getEffectiveCallingConvention - Return the actual calling convention to use, which may depend on the ...
void EmitNoreturnRuntimeCallOrInvoke(llvm::Value *callee, ArrayRef< llvm::Value * > args)
Emits a call or invoke to the given noreturn runtime function.
Definition: CGCall.cpp:3613
Base object ctor.
Definition: ABI.h:27
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:150
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:2523
uint32_t Offset
Definition: CacheTokens.cpp:43
const ValueDecl * getMemberPointerDecl() const
Definition: APValue.cpp:615
const CXXRecordDecl * getParent() const
Returns the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2018
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:2769
Deleting dtor.
Definition: ABI.h:35
CharUnits VFPtrOffset
This is the offset of the vfptr from the start of the last vbase, or the complete type if there are n...
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:147
static ConstantAddress getInitThreadEpochPtr(CodeGenModule &CGM)
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:378
void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::Constant *fn, llvm::Constant *addr)
Call atexit() with a function that passes the given argument to the given function.
Definition: CGDeclCXX.cpp:229
const VPtrInfoVector & getVFPtrOffsets(const CXXRecordDecl *RD)
CXXRecordDecl * getCanonicalDecl() override
Retrieves the "canonical" declaration of the given declaration.
Definition: DeclCXX.h:671
void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr, QualType DeleteTy, llvm::Value *NumElements=nullptr, CharUnits CookieSize=CharUnits())
Definition: CGExprCXX.cpp:1705
const ASTRecordLayout & getASTRecordLayout(const RecordDecl *D) const
Get or compute information about the layout of the specified record (struct/union/class) D...
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:85
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:2701
const CGFunctionInfo & arrangeCXXMethodDeclaration(const CXXMethodDecl *MD)
C++ methods have some special rules and also have implicit parameters.
Definition: CGCall.cpp:263
bool isStaticLocal() const
isStaticLocal - Returns true if a variable with function scope is a static local variable.
Definition: Decl.h:987
GlobalDecl CurGD
CurGD - The GlobalDecl for the current function being compiled.
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
detail::InMemoryDirectory::const_iterator I
bool defaultedCopyConstructorIsDeleted() const
true if a defaulted copy constructor for this class would be deleted.
Definition: DeclCXX.h:824
QualType getType() const
Definition: Decl.h:589
bool isMemberFunctionPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2465
arg_iterator arg_end()
Definition: Expr.h:2306
llvm::Constant * CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeList ExtraAttrs=llvm::AttributeList(), bool Local=false)
Create a new runtime function with the specified type and name.
bool isPositive() const
isPositive - Test whether the quantity is greater than zero.
Definition: CharUnits.h:122
static ImplicitParamDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, ImplicitParamKind ParamKind)
Create implicit parameter.
Definition: Decl.cpp:4161
llvm::CallSite EmitRuntimeCallOrInvoke(llvm::Value *callee, ArrayRef< llvm::Value * > args, const Twine &name="")
Emits a call or invoke instruction to the given runtime function.
Definition: CGCall.cpp:3644
FunctionDecl * getOperatorDelete() const
Definition: ExprCXX.h:2037
const CXXRecordDecl * VBase
If nonnull, holds the last vbase which contains the vfptr that the method definition is adjusted to...
AutoVarEmission EmitAutoVarAlloca(const VarDecl &var)
EmitAutoVarAlloca - Emit the alloca and debug information for a local variable.
Definition: CGDecl.cpp:953
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3129
llvm::CallInst * EmitNounwindRuntimeCall(llvm::Value *callee, const Twine &name="")
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:198
const TargetInfo & getTarget() const
CastKind
CastKind - The kind of operation required for a conversion.
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:38
union clang::ReturnAdjustment::VirtualAdjustment Virtual
ASTContext * Context
Module linkage, which indicates that the entity can be referred to from other translation units withi...
Definition: Linkage.h:57
static void emitCXXConstructor(CodeGenModule &CGM, const CXXConstructorDecl *ctor, StructorType ctorType)
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:414
bool hasUnaligned() const
Definition: Type.h:280
const CXXRecordDecl * getBase() const
getBase - Returns the base class declaration.
Definition: BaseSubobject.h:40
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:34
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:2474
CXXDtorType
C++ destructor types.
Definition: ABI.h:34
llvm::Value * getPointer() const
Definition: Address.h:38
bool isDeleted() const
Whether this function has been deleted.
Definition: Decl.h:1979
const Type * getTypeForDecl() const
Definition: Decl.h:2663
ValueDecl - Represent the declaration of a variable (in which case it is an lvalue) a function (in wh...
Definition: Decl.h:580
Expr - This represents one expression.
Definition: Expr.h:105
CXXDtorType getDtorType() const
Definition: GlobalDecl.h:69
bool isInstance() const
Definition: DeclCXX.h:1930
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 'void ()'.
Definition: CGCall.cpp:678
bool isVirtual() const
Definition: DeclCXX.h:1947
bool isMemberPointerToDerivedMember() const
Definition: APValue.cpp:622
static CGCallee forDirect(llvm::Constant *functionPtr, const CGCalleeInfo &abstractInfo=CGCalleeInfo())
Definition: CGCall.h:125
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2551
static llvm::CallSite emitRTtypeidCall(CodeGenFunction &CGF, llvm::Value *Argument)
DeclContext * getDeclContext()
Definition: DeclBase.h:416
ASTContext & getContext() const
CharUnits getBaseClassOffset(const CXXRecordDecl *Base) const
getBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:219
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:63
MicrosoftVTableContext & getMicrosoftVTableContext()
void add(RValue rvalue, QualType type, bool needscopy=false)
Definition: CGCall.h:207
llvm::LLVMContext & getLLVMContext()
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
Base object dtor.
Definition: ABI.h:37
QualType getAllocatedType() const
Definition: ExprCXX.h:1841
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1294
bool isExternallyVisible() const
Definition: Decl.h:338
unsigned Map[FirstTargetAddressSpace]
The type of a lookup table which maps from language-specific address spaces to target-specific ones...
Definition: AddressSpaces.h:53
CharUnits getVBPtrOffset() const
getVBPtrOffset - Get the offset for virtual base table pointer.
Definition: RecordLayout.h:292
llvm::Value * EmitCastToVoidPtr(llvm::Value *value)
Emit a cast to void* in the appropriate address space.
Definition: CGExpr.cpp:49
DeclarationName getDeclName() const
getDeclName - Get the actual, stored name of the declaration, which may be a special name...
Definition: Decl.h:258
unsigned getNumBases() const
Retrieves the number of base classes of this class.
Definition: DeclCXX.h:731
void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr, bool PerformInit)
EmitCXXGlobalVarDeclInit - Create the initializer for a C++ variable with global storage.
Definition: CGDeclCXX.cpp:142
The COMDAT used for dtors.
Definition: ABI.h:38
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:232
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:29
bool isObjectType() const
Determine whether this type is an object type.
Definition: Type.h:1610
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:45
uint64_t getFieldOffset(const ValueDecl *FD) const
Get the offset of a FieldDecl or IndirectFieldDecl, in bits.
unsigned getVBTableIndex(const CXXRecordDecl *Derived, const CXXRecordDecl *VBase)
Returns the index of VBase in the vbtable of Derived.
CXXRecordDecl * getMostRecentCXXRecordDecl() const
Definition: Type.cpp:3834
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:142
CharUnits getTypeAlignInChars(QualType T) const
Return the ABI-specified alignment of a (complete) type T, in characters.
SmallVectorImpl< AnnotatedLine * >::const_iterator Next
Encodes a location in the source.
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
unsigned getNumParams() const
getNumParams - Return the number of parameters this function must have based on its FunctionType...
Definition: Decl.cpp:2878
const Type * getTypePtr() const
Retrieves a pointer to the underlying (unqualified) type.
Definition: Type.h:5489
bool isEmpty() const
Definition: ABI.h:155
Represents a new-expression for memory allocation and constructor calls, e.g: "new CXXNewExpr(foo)"...
Definition: ExprCXX.h:1780
const std::string ID
Represents a call to a member function that may be written either with member call syntax (e...
Definition: ExprCXX.h:136
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.
llvm::Constant * createAtExitStub(const VarDecl &VD, llvm::Constant *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:196
Represents a single component in a vtable.
Definition: VTableBuilder.h:30
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:42
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1903
const VTableLayout & getVFTableLayout(const CXXRecordDecl *RD, CharUnits VFPtrOffset)
bool hasExtendableVFPtr() const
hasVFPtr - Does this class have a virtual function table pointer that can be extended by a derived cl...
Definition: RecordLayout.h:254
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2066
llvm::Constant * GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH=false)
Get the address of the RTTI descriptor for the given type.
ArrayRef< VTableComponent > vtable_components() const
const VBaseOffsetsMapTy & getVBaseOffsetsMap() const
Definition: RecordLayout.h:302
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:649
const CXXRecordDecl * ObjectWithVPtr
This is the most derived class that has this vptr at offset zero.
An aligned address.
Definition: Address.h:25
bool isMemberDataPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2471
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.
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6105
unsigned getCustomDiagID(Level L, const char(&FormatString)[N])
Return an ID for a diagnostic with the specified format string and level.
Definition: Diagnostic.h:689
All available information about a concrete callee.
Definition: CGCall.h:66
MangleContext & getMangleContext()
Gets the mangle context.
Definition: CGCXXABI.h:96
Complete object dtor.
Definition: ABI.h:36
llvm::Instruction * CurrentFuncletPad
unsigned getAddressSpace() const
Return the address space that this address resides in.
Definition: Address.h:57
CGCXXABI * CreateMicrosoftCXXABI(CodeGenModule &CGM)
Creates a Microsoft-family ABI.
bool isVirtuallyDerivedFrom(const CXXRecordDecl *Base) const
Determine whether this class is virtually derived from the class Base.
static void mangleVFTableName(MicrosoftMangleContext &MangleContext, const CXXRecordDecl *RD, const VPtrInfo &VFPtr, SmallString< 256 > &Name)
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:5559
virtual void mangleCXXVFTable(const CXXRecordDecl *Derived, ArrayRef< const CXXRecordDecl * > BasePath, raw_ostream &Out)=0
Mangle vftable symbols.
The MS C++ ABI needs a pointer to RTTI data plus some flags to describe the type of a catch handler...
Definition: CGCleanup.h:38
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
CXXCtorType
C++ constructor types.
Definition: ABI.h:25
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:216
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:276
QualType getType() const
Definition: Expr.h:127
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 ...
void ErrorUnsupported(const Stmt *S, const char *Type)
Print out an error that codegen doesn't support the specified stmt yet.
CGFunctionInfo - Class to encapsulate the information about a function definition.
CharUnits getAlignment() const
Return the alignment of this pointer.
Definition: Address.h:67
This class organizes the cross-function state that is used while generating LLVM code.
llvm::GlobalValue * GetGlobalValue(StringRef Ref)
const Expr * getSubExpr() const
Definition: ExprCXX.h:948
void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type, bool ForVirtualBase, bool Delegating, Address This)
Definition: CGClass.cpp:2302
Address getObjectAddress(CodeGenFunction &CGF) const
Returns the address of the object within this declaration.
External linkage within a unique namespace.
Definition: Linkage.h:42
static bool isDeletingDtor(GlobalDecl GD)
Represents a delete expression for memory deallocation and destructor calls, e.g. ...
Definition: ExprCXX.h:1992
AccessSpecifier getAccessSpecifier() const
Returns the access specifier for this base specifier.
Definition: DeclCXX.h:239
StringRef Name
Definition: USRFinder.cpp:123
bool isZero() const
isZero - Test whether the quantity equals zero.
Definition: CharUnits.h:116
const VPtrInfoVector & enumerateVBTables(const CXXRecordDecl *RD)
const internal::VariadicAllOfMatcher< Type > type
Matches Types in the clang AST.
Definition: ASTMatchers.h:2126
llvm::Value * getScalarVal() const
getScalarVal() - Return the Value* of this scalar value.
Definition: CGValue.h:58
bool TryEmitDefinitionAsAlias(GlobalDecl Alias, GlobalDecl Target, bool InEveryTU)
Try to emit a definition as a global alias for another definition.
Definition: CGCXX.cpp:120
llvm::LoadInst * CreateAlignedLoad(llvm::Value *Addr, CharUnits Align, const llvm::Twine &Name="")
Definition: CGBuilder.h:91
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:70
QualType getExceptionObjectType(QualType T) const
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:792
detail::InMemoryDirectory::const_iterator E
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:2442
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:108
void maybeSetTrivialComdat(const Decl &D, llvm::GlobalObject &GO)
CharUnits getVBaseAlignment(CharUnits DerivedAlign, const CXXRecordDecl *Derived, const CXXRecordDecl *VBase)
Returns the assumed alignment of a virtual base of a class.
Definition: CGClass.cpp:55
void EmitThunks(GlobalDecl GD)
EmitThunks - Emit the associated thunks for the given global decl.
Definition: CGVTables.cpp:509
union clang::ThisAdjustment::VirtualAdjustment Virtual
path_iterator path_end()
Definition: Expr.h:2770
void EmitAutoVarCleanups(const AutoVarEmission &emission)
Definition: CGDecl.cpp:1411
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:44
const T * getAs() const
Member-template getAs<specific type>'.
Definition: Type.h:6042
void AppendLinkerOptions(StringRef Opts)
Appends Opts to the "llvm.linker.options" metadata value.
static llvm::GlobalVariable * getTypeInfoVTable(CodeGenModule &CGM)
arg_iterator arg_begin()
Definition: Expr.h:2305
Implements C++ ABI-specific code generation functions.
Definition: CGCXXABI.h:44
This class organizes the cross-module state that is used while lowering AST types to LLVM types...
Definition: CodeGenTypes.h:120
SourceLocation getLocStart() const LLVM_READONLY
Definition: Expr.cpp:1326
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.
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1548
bool isTrivial() const
Whether this function is "trivial" in some specialized C++ senses.
Definition: Decl.h:1909
StringRef getMangledName(GlobalDecl GD)
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:33
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:436
APValue - This class implements a discriminated union of [uninitialized] [APSInt] [APFloat]...
Definition: APValue.h:38
Represents a base class of a C++ class.
Definition: DeclCXX.h:158
char __ovld __cnfn max(char x, char y)
Returns y if x < y, otherwise it returns x.
Linkage getLinkage() const
Determine the linkage of this type.
Definition: Type.cpp:3421
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2009
static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT, CGCXXABI &CXXABI)
Definition: TargetInfo.cpp:137
const Decl * CurFuncDecl
CurFuncDecl - Holds the Decl for the current outermost non-closure context.
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
DiagnosticsEngine & getDiags() const
QualType getUnqualifiedType() const
Retrieve the unqualified variant of the given type, removing as little sugar as possible.
Definition: Type.h:5569
Address CreateConstByteGEP(Address Addr, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:233
Represents a C++ struct/union/class.
Definition: DeclCXX.h:267
BoundNodesTreeBuilder *const Builder
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:190
llvm::Function * CreateGlobalInitOrDestructFunction(llvm::FunctionType *ty, const Twine &name, const CGFunctionInfo &FI, SourceLocation Loc=SourceLocation(), bool TLS=false)
Definition: CGDeclCXX.cpp:262
CXXCatchStmt - This represents a C++ catch block.
Definition: StmtCXX.h:29
llvm::Type * ConvertType(QualType T)
static void emitCXXDestructor(CodeGenModule &CGM, const CXXDestructorDecl *dtor, StructorType dtorType)
A specialization of Address that requires the address to be an LLVM Constant.
Definition: Address.h:75
CallingConv getDefaultCallingConvention(bool isVariadic, bool IsCXXMethod) const
Retrieves the default calling convention for the current target.
int32_t VtordispOffset
The offset of the vtordisp (in bytes), relative to the ECX.
Definition: ABI.h:125
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:46
struct clang::ReturnAdjustment::VirtualAdjustment::@117 Microsoft
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:245
Copying closure variant of a ctor.
Definition: ABI.h:29
CharUnits computeNonVirtualBaseClassOffset(const CXXRecordDecl *DerivedClass, CastExpr::path_const_iterator Start, CastExpr::path_const_iterator End)
Definition: CGClass.cpp:147
bool needsImplicitCopyConstructor() const
Determine whether this class needs an implicit copy constructor to be lazily declared.
Definition: DeclCXX.h:914
CharUnits FullOffsetInMDC
Static offset from the top of the most derived class to this vfptr, including any virtual base offset...
uint64_t Index
Method's index in the vftable.
const CGFunctionInfo & arrangeMSCtorClosure(const CXXConstructorDecl *CD, CXXCtorType CT)
Definition: CGCall.cpp:522
CanQualType IntTy
Definition: ASTContext.h:971
Struct with all informations about dynamic [sub]class needed to set vptr.
VarDecl * getExceptionDecl() const
Definition: StmtCXX.h:50
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
GVALinkage
A more specific kind of linkage than enum Linkage.
Definition: Linkage.h:75
Holds information about the inheritance path to a virtual base or function table pointer.
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Set the IRBuilder to not attach debug locations.
Definition: CGDebugInfo.h:665
llvm::StoreInst * CreateAlignedStore(llvm::Value *Val, llvm::Value *Addr, CharUnits Align, bool IsVolatile=false)
Definition: CGBuilder.h:115
CodeGenVTables & getVTables()
CharUnits getBaseOffset() const
getBaseOffset - Returns the base class offset.
Definition: BaseSubobject.h:43
uint32_t VBIndex
Index of the virtual base in the vbtable.
Definition: ABI.h:64
SourceLocation getLocation() const
Definition: DeclBase.h:407
LValue - This represents an lvalue references.
Definition: CGValue.h:171
unsigned getNumVBases() const
Retrieves the number of virtual base classes of this class.
Definition: DeclCXX.h:752
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:147
BasePath PathToIntroducingObject
This holds the base classes path from the complete type to the first base with the given vfptr offset...
const CXXConstructorDecl * getCopyConstructorForExceptionObject(CXXRecordDecl *RD)
bool CurFuncIsThunk
In C++, whether we are code generating a thunk.
Notes how many arguments were added to the beginning (Prefix) and ending (Suffix) of an arg list...
Definition: CGCXXABI.h:299
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:5548
RecordArgABI
Specify how one should pass an argument of a record type.
Definition: CGCXXABI.h:125
bool isNull() const
Return true if this QualType doesn't point to a type yet.
Definition: Type.h:683
bool nullFieldOffsetIsZero() const
In the Microsoft C++ ABI, use zero for the field offset of a null data member pointer if we can guara...
Definition: DeclCXX.h:1806
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:182
int32_t VBPtrOffset
The offset of the vbptr of the derived class (in bytes), relative to the ECX after vtordisp adjustmen...
Definition: ABI.h:129
Address CreateMemTemp(QualType T, const Twine &Name="tmp", bool CastToDefaultAddrSpace=true)
CreateMemTemp - Create a temporary memory object of the given type, with appropriate alignment...
Definition: CGExpr.cpp:123
void PopCleanupBlock(bool FallThroughIsBranchThrough=false)
PopCleanupBlock - Will pop the cleanup entry on the stack and process all branch fixups.
Definition: CGCleanup.cpp:640
static void serializeClassHierarchy(SmallVectorImpl< MSRTTIClass > &Classes, const CXXRecordDecl *RD)
Recursively serializes a class hierarchy in pre-order depth first order.
base_class_range vbases()
Definition: DeclCXX.h:754
bool isEmpty() const
Definition: ABI.h:87
static ABIArgInfo getIndirect(CharUnits Alignment, bool ByVal=true, bool Realign=false, llvm::Type *Padding=nullptr)
const NamedDecl * Result
Definition: USRFinder.cpp:70
llvm::Value * EmitVTableTypeCheckedLoad(const CXXRecordDecl *RD, llvm::Value *VTable, uint64_t VTableByteOffset)
Emit a type checked load from the given vtable.
Definition: CGClass.cpp:2694
const MethodVFTableLocation & getMethodVFTableLocation(GlobalDecl GD)
RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee, ReturnValueSlot ReturnValue, const CallArgList &Args, llvm::Instruction **callOrInvoke=nullptr)
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:3695
void EmitMustTailThunk(const CXXMethodDecl *MD, llvm::Value *AdjustedThisPtr, llvm::Value *Callee)
Emit a musttail call for a thunk with a potentially adjusted this pointer.
Definition: CGVTables.cpp:346
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:5516
static llvm::Constant * getThrowFn(CodeGenModule &CGM)
bool isPointerType() const
Definition: Type.h:5712
bool isPOD() const
Whether this class is a POD-type (C++ [class]p4)
Definition: DeclCXX.h:1210
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1519