clang  10.0.0svn
MicrosoftCXXABI.cpp
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1 //===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This provides C++ code generation targeting the Microsoft Visual C++ ABI.
10 // The class in this file generates structures that follow the Microsoft
11 // Visual C++ ABI, which is actually not very well documented at all outside
12 // of Microsoft.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "CGCXXABI.h"
17 #include "CGCleanup.h"
18 #include "CGVTables.h"
19 #include "CodeGenModule.h"
20 #include "CodeGenTypes.h"
21 #include "TargetInfo.h"
23 #include "clang/AST/Decl.h"
24 #include "clang/AST/DeclCXX.h"
25 #include "clang/AST/StmtCXX.h"
27 #include "llvm/ADT/StringExtras.h"
28 #include "llvm/ADT/StringSet.h"
29 #include "llvm/IR/Intrinsics.h"
30 
31 using namespace clang;
32 using namespace CodeGen;
33 
34 namespace {
35 
36 /// Holds all the vbtable globals for a given class.
37 struct VBTableGlobals {
38  const VPtrInfoVector *VBTables;
40 };
41 
42 class MicrosoftCXXABI : public CGCXXABI {
43 public:
44  MicrosoftCXXABI(CodeGenModule &CGM)
45  : CGCXXABI(CGM), BaseClassDescriptorType(nullptr),
46  ClassHierarchyDescriptorType(nullptr),
47  CompleteObjectLocatorType(nullptr), CatchableTypeType(nullptr),
48  ThrowInfoType(nullptr) {}
49 
50  bool HasThisReturn(GlobalDecl GD) const override;
51  bool hasMostDerivedReturn(GlobalDecl GD) const override;
52 
53  bool classifyReturnType(CGFunctionInfo &FI) const override;
54 
55  RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const override;
56 
57  bool isSRetParameterAfterThis() const override { return true; }
58 
59  bool isThisCompleteObject(GlobalDecl GD) const override {
60  // The Microsoft ABI doesn't use separate complete-object vs.
61  // base-object variants of constructors, but it does of destructors.
62  if (isa<CXXDestructorDecl>(GD.getDecl())) {
63  switch (GD.getDtorType()) {
64  case Dtor_Complete:
65  case Dtor_Deleting:
66  return true;
67 
68  case Dtor_Base:
69  return false;
70 
71  case Dtor_Comdat: llvm_unreachable("emitting dtor comdat as function?");
72  }
73  llvm_unreachable("bad dtor kind");
74  }
75 
76  // No other kinds.
77  return false;
78  }
79 
80  size_t getSrcArgforCopyCtor(const CXXConstructorDecl *CD,
81  FunctionArgList &Args) const override {
82  assert(Args.size() >= 2 &&
83  "expected the arglist to have at least two args!");
84  // The 'most_derived' parameter goes second if the ctor is variadic and
85  // has v-bases.
86  if (CD->getParent()->getNumVBases() > 0 &&
87  CD->getType()->castAs<FunctionProtoType>()->isVariadic())
88  return 2;
89  return 1;
90  }
91 
92  std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD) override {
93  std::vector<CharUnits> VBPtrOffsets;
94  const ASTContext &Context = getContext();
95  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
96 
97  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
98  for (const std::unique_ptr<VPtrInfo> &VBT : *VBGlobals.VBTables) {
99  const ASTRecordLayout &SubobjectLayout =
100  Context.getASTRecordLayout(VBT->IntroducingObject);
101  CharUnits Offs = VBT->NonVirtualOffset;
102  Offs += SubobjectLayout.getVBPtrOffset();
103  if (VBT->getVBaseWithVPtr())
104  Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
105  VBPtrOffsets.push_back(Offs);
106  }
107  llvm::array_pod_sort(VBPtrOffsets.begin(), VBPtrOffsets.end());
108  return VBPtrOffsets;
109  }
110 
111  StringRef GetPureVirtualCallName() override { return "_purecall"; }
112  StringRef GetDeletedVirtualCallName() override { return "_purecall"; }
113 
114  void emitVirtualObjectDelete(CodeGenFunction &CGF, const CXXDeleteExpr *DE,
115  Address Ptr, QualType ElementType,
116  const CXXDestructorDecl *Dtor) override;
117 
118  void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) override;
119  void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) override;
120 
121  void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) override;
122 
123  llvm::GlobalVariable *getMSCompleteObjectLocator(const CXXRecordDecl *RD,
124  const VPtrInfo &Info);
125 
126  llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) override;
128  getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) override;
129 
130  /// MSVC needs an extra flag to indicate a catchall.
131  CatchTypeInfo getCatchAllTypeInfo() override {
132  return CatchTypeInfo{nullptr, 0x40};
133  }
134 
135  bool shouldTypeidBeNullChecked(bool IsDeref, QualType SrcRecordTy) override;
136  void EmitBadTypeidCall(CodeGenFunction &CGF) override;
137  llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
138  Address ThisPtr,
139  llvm::Type *StdTypeInfoPtrTy) override;
140 
141  bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
142  QualType SrcRecordTy) override;
143 
144  llvm::Value *EmitDynamicCastCall(CodeGenFunction &CGF, Address Value,
145  QualType SrcRecordTy, QualType DestTy,
146  QualType DestRecordTy,
147  llvm::BasicBlock *CastEnd) override;
148 
149  llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
150  QualType SrcRecordTy,
151  QualType DestTy) override;
152 
153  bool EmitBadCastCall(CodeGenFunction &CGF) override;
154  bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const override {
155  return false;
156  }
157 
158  llvm::Value *
159  GetVirtualBaseClassOffset(CodeGenFunction &CGF, Address This,
160  const CXXRecordDecl *ClassDecl,
161  const CXXRecordDecl *BaseClassDecl) override;
162 
163  llvm::BasicBlock *
164  EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
165  const CXXRecordDecl *RD) override;
166 
167  llvm::BasicBlock *
168  EmitDtorCompleteObjectHandler(CodeGenFunction &CGF);
169 
170  void initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
171  const CXXRecordDecl *RD) override;
172 
173  void EmitCXXConstructors(const CXXConstructorDecl *D) override;
174 
175  // Background on MSVC destructors
176  // ==============================
177  //
178  // Both Itanium and MSVC ABIs have destructor variants. The variant names
179  // roughly correspond in the following way:
180  // Itanium Microsoft
181  // Base -> no name, just ~Class
182  // Complete -> vbase destructor
183  // Deleting -> scalar deleting destructor
184  // vector deleting destructor
185  //
186  // The base and complete destructors are the same as in Itanium, although the
187  // complete destructor does not accept a VTT parameter when there are virtual
188  // bases. A separate mechanism involving vtordisps is used to ensure that
189  // virtual methods of destroyed subobjects are not called.
190  //
191  // The deleting destructors accept an i32 bitfield as a second parameter. Bit
192  // 1 indicates if the memory should be deleted. Bit 2 indicates if the this
193  // pointer points to an array. The scalar deleting destructor assumes that
194  // bit 2 is zero, and therefore does not contain a loop.
195  //
196  // For virtual destructors, only one entry is reserved in the vftable, and it
197  // always points to the vector deleting destructor. The vector deleting
198  // destructor is the most general, so it can be used to destroy objects in
199  // place, delete single heap objects, or delete arrays.
200  //
201  // A TU defining a non-inline destructor is only guaranteed to emit a base
202  // destructor, and all of the other variants are emitted on an as-needed basis
203  // in COMDATs. Because a non-base destructor can be emitted in a TU that
204  // lacks a definition for the destructor, non-base destructors must always
205  // delegate to or alias the base destructor.
206 
207  AddedStructorArgs
208  buildStructorSignature(GlobalDecl GD,
209  SmallVectorImpl<CanQualType> &ArgTys) override;
210 
211  /// Non-base dtors should be emitted as delegating thunks in this ABI.
212  bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
213  CXXDtorType DT) const override {
214  return DT != Dtor_Base;
215  }
216 
217  void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
218  const CXXDestructorDecl *Dtor,
219  CXXDtorType DT) const override;
220 
221  llvm::GlobalValue::LinkageTypes
222  getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
223  CXXDtorType DT) const override;
224 
225  void EmitCXXDestructors(const CXXDestructorDecl *D) override;
226 
227  const CXXRecordDecl *
228  getThisArgumentTypeForMethod(const CXXMethodDecl *MD) override {
229  if (MD->isVirtual() && !isa<CXXDestructorDecl>(MD)) {
231  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(MD);
232  // The vbases might be ordered differently in the final overrider object
233  // and the complete object, so the "this" argument may sometimes point to
234  // memory that has no particular type (e.g. past the complete object).
235  // In this case, we just use a generic pointer type.
236  // FIXME: might want to have a more precise type in the non-virtual
237  // multiple inheritance case.
238  if (ML.VBase || !ML.VFPtrOffset.isZero())
239  return nullptr;
240  }
241  return MD->getParent();
242  }
243 
244  Address
245  adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
246  Address This,
247  bool VirtualCall) override;
248 
249  void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
250  FunctionArgList &Params) override;
251 
252  void EmitInstanceFunctionProlog(CodeGenFunction &CGF) override;
253 
254  AddedStructorArgs
255  addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
256  CXXCtorType Type, bool ForVirtualBase,
257  bool Delegating, CallArgList &Args) override;
258 
259  void EmitDestructorCall(CodeGenFunction &CGF, const CXXDestructorDecl *DD,
260  CXXDtorType Type, bool ForVirtualBase,
261  bool Delegating, Address This,
262  QualType ThisTy) override;
263 
264  void emitVTableTypeMetadata(const VPtrInfo &Info, const CXXRecordDecl *RD,
265  llvm::GlobalVariable *VTable);
266 
267  void emitVTableDefinitions(CodeGenVTables &CGVT,
268  const CXXRecordDecl *RD) override;
269 
270  bool isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
271  CodeGenFunction::VPtr Vptr) override;
272 
273  /// Don't initialize vptrs if dynamic class
274  /// is marked with with the 'novtable' attribute.
275  bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) override {
276  return !VTableClass->hasAttr<MSNoVTableAttr>();
277  }
278 
279  llvm::Constant *
280  getVTableAddressPoint(BaseSubobject Base,
281  const CXXRecordDecl *VTableClass) override;
282 
283  llvm::Value *getVTableAddressPointInStructor(
284  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass,
285  BaseSubobject Base, const CXXRecordDecl *NearestVBase) override;
286 
287  llvm::Constant *
288  getVTableAddressPointForConstExpr(BaseSubobject Base,
289  const CXXRecordDecl *VTableClass) override;
290 
291  llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
292  CharUnits VPtrOffset) override;
293 
294  CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF, GlobalDecl GD,
295  Address This, llvm::Type *Ty,
296  SourceLocation Loc) override;
297 
298  llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
299  const CXXDestructorDecl *Dtor,
300  CXXDtorType DtorType, Address This,
301  DeleteOrMemberCallExpr E) override;
302 
303  void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF, GlobalDecl GD,
304  CallArgList &CallArgs) override {
305  assert(GD.getDtorType() == Dtor_Deleting &&
306  "Only deleting destructor thunks are available in this ABI");
307  CallArgs.add(RValue::get(getStructorImplicitParamValue(CGF)),
308  getContext().IntTy);
309  }
310 
311  void emitVirtualInheritanceTables(const CXXRecordDecl *RD) override;
312 
313  llvm::GlobalVariable *
314  getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
315  llvm::GlobalVariable::LinkageTypes Linkage);
316 
317  llvm::GlobalVariable *
318  getAddrOfVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
319  const CXXRecordDecl *DstRD) {
320  SmallString<256> OutName;
321  llvm::raw_svector_ostream Out(OutName);
322  getMangleContext().mangleCXXVirtualDisplacementMap(SrcRD, DstRD, Out);
323  StringRef MangledName = OutName.str();
324 
325  if (auto *VDispMap = CGM.getModule().getNamedGlobal(MangledName))
326  return VDispMap;
327 
328  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
329  unsigned NumEntries = 1 + SrcRD->getNumVBases();
330  SmallVector<llvm::Constant *, 4> Map(NumEntries,
331  llvm::UndefValue::get(CGM.IntTy));
332  Map[0] = llvm::ConstantInt::get(CGM.IntTy, 0);
333  bool AnyDifferent = false;
334  for (const auto &I : SrcRD->vbases()) {
335  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
336  if (!DstRD->isVirtuallyDerivedFrom(VBase))
337  continue;
338 
339  unsigned SrcVBIndex = VTContext.getVBTableIndex(SrcRD, VBase);
340  unsigned DstVBIndex = VTContext.getVBTableIndex(DstRD, VBase);
341  Map[SrcVBIndex] = llvm::ConstantInt::get(CGM.IntTy, DstVBIndex * 4);
342  AnyDifferent |= SrcVBIndex != DstVBIndex;
343  }
344  // This map would be useless, don't use it.
345  if (!AnyDifferent)
346  return nullptr;
347 
348  llvm::ArrayType *VDispMapTy = llvm::ArrayType::get(CGM.IntTy, Map.size());
349  llvm::Constant *Init = llvm::ConstantArray::get(VDispMapTy, Map);
350  llvm::GlobalValue::LinkageTypes Linkage =
351  SrcRD->isExternallyVisible() && DstRD->isExternallyVisible()
352  ? llvm::GlobalValue::LinkOnceODRLinkage
354  auto *VDispMap = new llvm::GlobalVariable(
355  CGM.getModule(), VDispMapTy, /*isConstant=*/true, Linkage,
356  /*Initializer=*/Init, MangledName);
357  return VDispMap;
358  }
359 
360  void emitVBTableDefinition(const VPtrInfo &VBT, const CXXRecordDecl *RD,
361  llvm::GlobalVariable *GV) const;
362 
363  void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
364  GlobalDecl GD, bool ReturnAdjustment) override {
365  GVALinkage Linkage =
366  getContext().GetGVALinkageForFunction(cast<FunctionDecl>(GD.getDecl()));
367 
368  if (Linkage == GVA_Internal)
369  Thunk->setLinkage(llvm::GlobalValue::InternalLinkage);
370  else if (ReturnAdjustment)
371  Thunk->setLinkage(llvm::GlobalValue::WeakODRLinkage);
372  else
373  Thunk->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
374  }
375 
376  bool exportThunk() override { return false; }
377 
378  llvm::Value *performThisAdjustment(CodeGenFunction &CGF, Address This,
379  const ThisAdjustment &TA) override;
380 
381  llvm::Value *performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
382  const ReturnAdjustment &RA) override;
383 
384  void EmitThreadLocalInitFuncs(
385  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
386  ArrayRef<llvm::Function *> CXXThreadLocalInits,
387  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) override;
388 
389  bool usesThreadWrapperFunction() const override { return false; }
390  LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF, const VarDecl *VD,
391  QualType LValType) override;
392 
393  void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
394  llvm::GlobalVariable *DeclPtr,
395  bool PerformInit) override;
396  void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
397  llvm::FunctionCallee Dtor,
398  llvm::Constant *Addr) override;
399 
400  // ==== Notes on array cookies =========
401  //
402  // MSVC seems to only use cookies when the class has a destructor; a
403  // two-argument usual array deallocation function isn't sufficient.
404  //
405  // For example, this code prints "100" and "1":
406  // struct A {
407  // char x;
408  // void *operator new[](size_t sz) {
409  // printf("%u\n", sz);
410  // return malloc(sz);
411  // }
412  // void operator delete[](void *p, size_t sz) {
413  // printf("%u\n", sz);
414  // free(p);
415  // }
416  // };
417  // int main() {
418  // A *p = new A[100];
419  // delete[] p;
420  // }
421  // Whereas it prints "104" and "104" if you give A a destructor.
422 
423  bool requiresArrayCookie(const CXXDeleteExpr *expr,
424  QualType elementType) override;
425  bool requiresArrayCookie(const CXXNewExpr *expr) override;
426  CharUnits getArrayCookieSizeImpl(QualType type) override;
427  Address InitializeArrayCookie(CodeGenFunction &CGF,
428  Address NewPtr,
429  llvm::Value *NumElements,
430  const CXXNewExpr *expr,
431  QualType ElementType) override;
432  llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
433  Address allocPtr,
434  CharUnits cookieSize) override;
435 
436  friend struct MSRTTIBuilder;
437 
438  bool isImageRelative() const {
439  return CGM.getTarget().getPointerWidth(/*AddrSpace=*/0) == 64;
440  }
441 
442  // 5 routines for constructing the llvm types for MS RTTI structs.
443  llvm::StructType *getTypeDescriptorType(StringRef TypeInfoString) {
444  llvm::SmallString<32> TDTypeName("rtti.TypeDescriptor");
445  TDTypeName += llvm::utostr(TypeInfoString.size());
446  llvm::StructType *&TypeDescriptorType =
447  TypeDescriptorTypeMap[TypeInfoString.size()];
448  if (TypeDescriptorType)
449  return TypeDescriptorType;
450  llvm::Type *FieldTypes[] = {
451  CGM.Int8PtrPtrTy,
452  CGM.Int8PtrTy,
453  llvm::ArrayType::get(CGM.Int8Ty, TypeInfoString.size() + 1)};
454  TypeDescriptorType =
455  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, TDTypeName);
456  return TypeDescriptorType;
457  }
458 
459  llvm::Type *getImageRelativeType(llvm::Type *PtrType) {
460  if (!isImageRelative())
461  return PtrType;
462  return CGM.IntTy;
463  }
464 
465  llvm::StructType *getBaseClassDescriptorType() {
466  if (BaseClassDescriptorType)
467  return BaseClassDescriptorType;
468  llvm::Type *FieldTypes[] = {
469  getImageRelativeType(CGM.Int8PtrTy),
470  CGM.IntTy,
471  CGM.IntTy,
472  CGM.IntTy,
473  CGM.IntTy,
474  CGM.IntTy,
475  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
476  };
477  BaseClassDescriptorType = llvm::StructType::create(
478  CGM.getLLVMContext(), FieldTypes, "rtti.BaseClassDescriptor");
479  return BaseClassDescriptorType;
480  }
481 
482  llvm::StructType *getClassHierarchyDescriptorType() {
483  if (ClassHierarchyDescriptorType)
484  return ClassHierarchyDescriptorType;
485  // Forward-declare RTTIClassHierarchyDescriptor to break a cycle.
486  ClassHierarchyDescriptorType = llvm::StructType::create(
487  CGM.getLLVMContext(), "rtti.ClassHierarchyDescriptor");
488  llvm::Type *FieldTypes[] = {
489  CGM.IntTy,
490  CGM.IntTy,
491  CGM.IntTy,
492  getImageRelativeType(
493  getBaseClassDescriptorType()->getPointerTo()->getPointerTo()),
494  };
495  ClassHierarchyDescriptorType->setBody(FieldTypes);
496  return ClassHierarchyDescriptorType;
497  }
498 
499  llvm::StructType *getCompleteObjectLocatorType() {
500  if (CompleteObjectLocatorType)
501  return CompleteObjectLocatorType;
502  CompleteObjectLocatorType = llvm::StructType::create(
503  CGM.getLLVMContext(), "rtti.CompleteObjectLocator");
504  llvm::Type *FieldTypes[] = {
505  CGM.IntTy,
506  CGM.IntTy,
507  CGM.IntTy,
508  getImageRelativeType(CGM.Int8PtrTy),
509  getImageRelativeType(getClassHierarchyDescriptorType()->getPointerTo()),
510  getImageRelativeType(CompleteObjectLocatorType),
511  };
512  llvm::ArrayRef<llvm::Type *> FieldTypesRef(FieldTypes);
513  if (!isImageRelative())
514  FieldTypesRef = FieldTypesRef.drop_back();
515  CompleteObjectLocatorType->setBody(FieldTypesRef);
516  return CompleteObjectLocatorType;
517  }
518 
519  llvm::GlobalVariable *getImageBase() {
520  StringRef Name = "__ImageBase";
521  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(Name))
522  return GV;
523 
524  auto *GV = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty,
525  /*isConstant=*/true,
527  /*Initializer=*/nullptr, Name);
528  CGM.setDSOLocal(GV);
529  return GV;
530  }
531 
532  llvm::Constant *getImageRelativeConstant(llvm::Constant *PtrVal) {
533  if (!isImageRelative())
534  return PtrVal;
535 
536  if (PtrVal->isNullValue())
537  return llvm::Constant::getNullValue(CGM.IntTy);
538 
539  llvm::Constant *ImageBaseAsInt =
540  llvm::ConstantExpr::getPtrToInt(getImageBase(), CGM.IntPtrTy);
541  llvm::Constant *PtrValAsInt =
542  llvm::ConstantExpr::getPtrToInt(PtrVal, CGM.IntPtrTy);
543  llvm::Constant *Diff =
544  llvm::ConstantExpr::getSub(PtrValAsInt, ImageBaseAsInt,
545  /*HasNUW=*/true, /*HasNSW=*/true);
546  return llvm::ConstantExpr::getTrunc(Diff, CGM.IntTy);
547  }
548 
549 private:
550  MicrosoftMangleContext &getMangleContext() {
551  return cast<MicrosoftMangleContext>(CodeGen::CGCXXABI::getMangleContext());
552  }
553 
554  llvm::Constant *getZeroInt() {
555  return llvm::ConstantInt::get(CGM.IntTy, 0);
556  }
557 
558  llvm::Constant *getAllOnesInt() {
559  return llvm::Constant::getAllOnesValue(CGM.IntTy);
560  }
561 
562  CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) override;
563 
564  void
565  GetNullMemberPointerFields(const MemberPointerType *MPT,
567 
568  /// Shared code for virtual base adjustment. Returns the offset from
569  /// the vbptr to the virtual base. Optionally returns the address of the
570  /// vbptr itself.
571  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
572  Address Base,
573  llvm::Value *VBPtrOffset,
574  llvm::Value *VBTableOffset,
575  llvm::Value **VBPtr = nullptr);
576 
577  llvm::Value *GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
578  Address Base,
579  int32_t VBPtrOffset,
580  int32_t VBTableOffset,
581  llvm::Value **VBPtr = nullptr) {
582  assert(VBTableOffset % 4 == 0 && "should be byte offset into table of i32s");
583  llvm::Value *VBPOffset = llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
584  *VBTOffset = llvm::ConstantInt::get(CGM.IntTy, VBTableOffset);
585  return GetVBaseOffsetFromVBPtr(CGF, Base, VBPOffset, VBTOffset, VBPtr);
586  }
587 
588  std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
589  performBaseAdjustment(CodeGenFunction &CGF, Address Value,
590  QualType SrcRecordTy);
591 
592  /// Performs a full virtual base adjustment. Used to dereference
593  /// pointers to members of virtual bases.
594  llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const Expr *E,
595  const CXXRecordDecl *RD, Address Base,
596  llvm::Value *VirtualBaseAdjustmentOffset,
597  llvm::Value *VBPtrOffset /* optional */);
598 
599  /// Emits a full member pointer with the fields common to data and
600  /// function member pointers.
601  llvm::Constant *EmitFullMemberPointer(llvm::Constant *FirstField,
602  bool IsMemberFunction,
603  const CXXRecordDecl *RD,
604  CharUnits NonVirtualBaseAdjustment,
605  unsigned VBTableIndex);
606 
607  bool MemberPointerConstantIsNull(const MemberPointerType *MPT,
608  llvm::Constant *MP);
609 
610  /// - Initialize all vbptrs of 'this' with RD as the complete type.
611  void EmitVBPtrStores(CodeGenFunction &CGF, const CXXRecordDecl *RD);
612 
613  /// Caching wrapper around VBTableBuilder::enumerateVBTables().
614  const VBTableGlobals &enumerateVBTables(const CXXRecordDecl *RD);
615 
616  /// Generate a thunk for calling a virtual member function MD.
617  llvm::Function *EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
618  const MethodVFTableLocation &ML);
619 
620 public:
621  llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT) override;
622 
623  bool isZeroInitializable(const MemberPointerType *MPT) override;
624 
625  bool isMemberPointerConvertible(const MemberPointerType *MPT) const override {
626  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
627  return RD->hasAttr<MSInheritanceAttr>();
628  }
629 
630  llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT) override;
631 
632  llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
633  CharUnits offset) override;
634  llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD) override;
635  llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT) override;
636 
637  llvm::Value *EmitMemberPointerComparison(CodeGenFunction &CGF,
638  llvm::Value *L,
639  llvm::Value *R,
640  const MemberPointerType *MPT,
641  bool Inequality) override;
642 
643  llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
644  llvm::Value *MemPtr,
645  const MemberPointerType *MPT) override;
646 
647  llvm::Value *
648  EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
649  Address Base, llvm::Value *MemPtr,
650  const MemberPointerType *MPT) override;
651 
652  llvm::Value *EmitNonNullMemberPointerConversion(
653  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
656  CGBuilderTy &Builder);
657 
658  llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
659  const CastExpr *E,
660  llvm::Value *Src) override;
661 
662  llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
663  llvm::Constant *Src) override;
664 
665  llvm::Constant *EmitMemberPointerConversion(
666  const MemberPointerType *SrcTy, const MemberPointerType *DstTy,
668  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src);
669 
670  CGCallee
671  EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF, const Expr *E,
672  Address This, llvm::Value *&ThisPtrForCall,
673  llvm::Value *MemPtr,
674  const MemberPointerType *MPT) override;
675 
676  void emitCXXStructor(GlobalDecl GD) override;
677 
678  llvm::StructType *getCatchableTypeType() {
679  if (CatchableTypeType)
680  return CatchableTypeType;
681  llvm::Type *FieldTypes[] = {
682  CGM.IntTy, // Flags
683  getImageRelativeType(CGM.Int8PtrTy), // TypeDescriptor
684  CGM.IntTy, // NonVirtualAdjustment
685  CGM.IntTy, // OffsetToVBPtr
686  CGM.IntTy, // VBTableIndex
687  CGM.IntTy, // Size
688  getImageRelativeType(CGM.Int8PtrTy) // CopyCtor
689  };
690  CatchableTypeType = llvm::StructType::create(
691  CGM.getLLVMContext(), FieldTypes, "eh.CatchableType");
692  return CatchableTypeType;
693  }
694 
695  llvm::StructType *getCatchableTypeArrayType(uint32_t NumEntries) {
696  llvm::StructType *&CatchableTypeArrayType =
697  CatchableTypeArrayTypeMap[NumEntries];
698  if (CatchableTypeArrayType)
699  return CatchableTypeArrayType;
700 
701  llvm::SmallString<23> CTATypeName("eh.CatchableTypeArray.");
702  CTATypeName += llvm::utostr(NumEntries);
703  llvm::Type *CTType =
704  getImageRelativeType(getCatchableTypeType()->getPointerTo());
705  llvm::Type *FieldTypes[] = {
706  CGM.IntTy, // NumEntries
707  llvm::ArrayType::get(CTType, NumEntries) // CatchableTypes
708  };
709  CatchableTypeArrayType =
710  llvm::StructType::create(CGM.getLLVMContext(), FieldTypes, CTATypeName);
711  return CatchableTypeArrayType;
712  }
713 
714  llvm::StructType *getThrowInfoType() {
715  if (ThrowInfoType)
716  return ThrowInfoType;
717  llvm::Type *FieldTypes[] = {
718  CGM.IntTy, // Flags
719  getImageRelativeType(CGM.Int8PtrTy), // CleanupFn
720  getImageRelativeType(CGM.Int8PtrTy), // ForwardCompat
721  getImageRelativeType(CGM.Int8PtrTy) // CatchableTypeArray
722  };
723  ThrowInfoType = llvm::StructType::create(CGM.getLLVMContext(), FieldTypes,
724  "eh.ThrowInfo");
725  return ThrowInfoType;
726  }
727 
728  llvm::FunctionCallee getThrowFn() {
729  // _CxxThrowException is passed an exception object and a ThrowInfo object
730  // which describes the exception.
731  llvm::Type *Args[] = {CGM.Int8PtrTy, getThrowInfoType()->getPointerTo()};
732  llvm::FunctionType *FTy =
733  llvm::FunctionType::get(CGM.VoidTy, Args, /*isVarArg=*/false);
734  llvm::FunctionCallee Throw =
735  CGM.CreateRuntimeFunction(FTy, "_CxxThrowException");
736  // _CxxThrowException is stdcall on 32-bit x86 platforms.
737  if (CGM.getTarget().getTriple().getArch() == llvm::Triple::x86) {
738  if (auto *Fn = dyn_cast<llvm::Function>(Throw.getCallee()))
739  Fn->setCallingConv(llvm::CallingConv::X86_StdCall);
740  }
741  return Throw;
742  }
743 
744  llvm::Function *getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
745  CXXCtorType CT);
746 
747  llvm::Constant *getCatchableType(QualType T,
748  uint32_t NVOffset = 0,
749  int32_t VBPtrOffset = -1,
750  uint32_t VBIndex = 0);
751 
752  llvm::GlobalVariable *getCatchableTypeArray(QualType T);
753 
754  llvm::GlobalVariable *getThrowInfo(QualType T) override;
755 
756  std::pair<llvm::Value *, const CXXRecordDecl *>
757  LoadVTablePtr(CodeGenFunction &CGF, Address This,
758  const CXXRecordDecl *RD) override;
759 
760 private:
761  typedef std::pair<const CXXRecordDecl *, CharUnits> VFTableIdTy;
762  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalVariable *> VTablesMapTy;
763  typedef llvm::DenseMap<VFTableIdTy, llvm::GlobalValue *> VFTablesMapTy;
764  /// All the vftables that have been referenced.
765  VFTablesMapTy VFTablesMap;
766  VTablesMapTy VTablesMap;
767 
768  /// This set holds the record decls we've deferred vtable emission for.
769  llvm::SmallPtrSet<const CXXRecordDecl *, 4> DeferredVFTables;
770 
771 
772  /// All the vbtables which have been referenced.
773  llvm::DenseMap<const CXXRecordDecl *, VBTableGlobals> VBTablesMap;
774 
775  /// Info on the global variable used to guard initialization of static locals.
776  /// The BitIndex field is only used for externally invisible declarations.
777  struct GuardInfo {
778  GuardInfo() : Guard(nullptr), BitIndex(0) {}
779  llvm::GlobalVariable *Guard;
780  unsigned BitIndex;
781  };
782 
783  /// Map from DeclContext to the current guard variable. We assume that the
784  /// AST is visited in source code order.
785  llvm::DenseMap<const DeclContext *, GuardInfo> GuardVariableMap;
786  llvm::DenseMap<const DeclContext *, GuardInfo> ThreadLocalGuardVariableMap;
787  llvm::DenseMap<const DeclContext *, unsigned> ThreadSafeGuardNumMap;
788 
789  llvm::DenseMap<size_t, llvm::StructType *> TypeDescriptorTypeMap;
790  llvm::StructType *BaseClassDescriptorType;
791  llvm::StructType *ClassHierarchyDescriptorType;
792  llvm::StructType *CompleteObjectLocatorType;
793 
794  llvm::DenseMap<QualType, llvm::GlobalVariable *> CatchableTypeArrays;
795 
796  llvm::StructType *CatchableTypeType;
797  llvm::DenseMap<uint32_t, llvm::StructType *> CatchableTypeArrayTypeMap;
798  llvm::StructType *ThrowInfoType;
799 };
800 
801 }
802 
805  switch (CGM.getTarget().getTriple().getArch()) {
806  default:
807  // FIXME: Implement for other architectures.
808  return RAA_Default;
809 
810  case llvm::Triple::thumb:
811  // Use the simple Itanium rules for now.
812  // FIXME: This is incompatible with MSVC for arguments with a dtor and no
813  // copy ctor.
814  return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
815 
816  case llvm::Triple::x86:
817  // All record arguments are passed in memory on x86. Decide whether to
818  // construct the object directly in argument memory, or to construct the
819  // argument elsewhere and copy the bytes during the call.
820 
821  // If C++ prohibits us from making a copy, construct the arguments directly
822  // into argument memory.
823  if (!RD->canPassInRegisters())
824  return RAA_DirectInMemory;
825 
826  // Otherwise, construct the argument into a temporary and copy the bytes
827  // into the outgoing argument memory.
828  return RAA_Default;
829 
830  case llvm::Triple::x86_64:
831  case llvm::Triple::aarch64:
832  return !RD->canPassInRegisters() ? RAA_Indirect : RAA_Default;
833  }
834 
835  llvm_unreachable("invalid enum");
836 }
837 
838 void MicrosoftCXXABI::emitVirtualObjectDelete(CodeGenFunction &CGF,
839  const CXXDeleteExpr *DE,
840  Address Ptr,
841  QualType ElementType,
842  const CXXDestructorDecl *Dtor) {
843  // FIXME: Provide a source location here even though there's no
844  // CXXMemberCallExpr for dtor call.
845  bool UseGlobalDelete = DE->isGlobalDelete();
846  CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
847  llvm::Value *MDThis = EmitVirtualDestructorCall(CGF, Dtor, DtorType, Ptr, DE);
848  if (UseGlobalDelete)
849  CGF.EmitDeleteCall(DE->getOperatorDelete(), MDThis, ElementType);
850 }
851 
852 void MicrosoftCXXABI::emitRethrow(CodeGenFunction &CGF, bool isNoReturn) {
853  llvm::Value *Args[] = {
854  llvm::ConstantPointerNull::get(CGM.Int8PtrTy),
855  llvm::ConstantPointerNull::get(getThrowInfoType()->getPointerTo())};
856  llvm::FunctionCallee Fn = getThrowFn();
857  if (isNoReturn)
858  CGF.EmitNoreturnRuntimeCallOrInvoke(Fn, Args);
859  else
860  CGF.EmitRuntimeCallOrInvoke(Fn, Args);
861 }
862 
863 void MicrosoftCXXABI::emitBeginCatch(CodeGenFunction &CGF,
864  const CXXCatchStmt *S) {
865  // In the MS ABI, the runtime handles the copy, and the catch handler is
866  // responsible for destruction.
867  VarDecl *CatchParam = S->getExceptionDecl();
868  llvm::BasicBlock *CatchPadBB = CGF.Builder.GetInsertBlock();
869  llvm::CatchPadInst *CPI =
870  cast<llvm::CatchPadInst>(CatchPadBB->getFirstNonPHI());
871  CGF.CurrentFuncletPad = CPI;
872 
873  // If this is a catch-all or the catch parameter is unnamed, we don't need to
874  // emit an alloca to the object.
875  if (!CatchParam || !CatchParam->getDeclName()) {
876  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
877  return;
878  }
879 
881  CPI->setArgOperand(2, var.getObjectAddress(CGF).getPointer());
882  CGF.EHStack.pushCleanup<CatchRetScope>(NormalCleanup, CPI);
883  CGF.EmitAutoVarCleanups(var);
884 }
885 
886 /// We need to perform a generic polymorphic operation (like a typeid
887 /// or a cast), which requires an object with a vfptr. Adjust the
888 /// address to point to an object with a vfptr.
889 std::tuple<Address, llvm::Value *, const CXXRecordDecl *>
890 MicrosoftCXXABI::performBaseAdjustment(CodeGenFunction &CGF, Address Value,
891  QualType SrcRecordTy) {
892  Value = CGF.Builder.CreateBitCast(Value, CGF.Int8PtrTy);
893  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
894  const ASTContext &Context = getContext();
895 
896  // If the class itself has a vfptr, great. This check implicitly
897  // covers non-virtual base subobjects: a class with its own virtual
898  // functions would be a candidate to be a primary base.
899  if (Context.getASTRecordLayout(SrcDecl).hasExtendableVFPtr())
900  return std::make_tuple(Value, llvm::ConstantInt::get(CGF.Int32Ty, 0),
901  SrcDecl);
902 
903  // Okay, one of the vbases must have a vfptr, or else this isn't
904  // actually a polymorphic class.
905  const CXXRecordDecl *PolymorphicBase = nullptr;
906  for (auto &Base : SrcDecl->vbases()) {
907  const CXXRecordDecl *BaseDecl = Base.getType()->getAsCXXRecordDecl();
908  if (Context.getASTRecordLayout(BaseDecl).hasExtendableVFPtr()) {
909  PolymorphicBase = BaseDecl;
910  break;
911  }
912  }
913  assert(PolymorphicBase && "polymorphic class has no apparent vfptr?");
914 
916  GetVirtualBaseClassOffset(CGF, Value, SrcDecl, PolymorphicBase);
917  llvm::Value *Ptr = CGF.Builder.CreateInBoundsGEP(Value.getPointer(), Offset);
918  CharUnits VBaseAlign =
919  CGF.CGM.getVBaseAlignment(Value.getAlignment(), SrcDecl, PolymorphicBase);
920  return std::make_tuple(Address(Ptr, VBaseAlign), Offset, PolymorphicBase);
921 }
922 
923 bool MicrosoftCXXABI::shouldTypeidBeNullChecked(bool IsDeref,
924  QualType SrcRecordTy) {
925  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
926  return IsDeref &&
927  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
928 }
929 
930 static llvm::CallBase *emitRTtypeidCall(CodeGenFunction &CGF,
931  llvm::Value *Argument) {
932  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
933  llvm::FunctionType *FTy =
934  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false);
935  llvm::Value *Args[] = {Argument};
936  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(FTy, "__RTtypeid");
937  return CGF.EmitRuntimeCallOrInvoke(Fn, Args);
938 }
939 
940 void MicrosoftCXXABI::EmitBadTypeidCall(CodeGenFunction &CGF) {
941  llvm::CallBase *Call =
942  emitRTtypeidCall(CGF, llvm::Constant::getNullValue(CGM.VoidPtrTy));
943  Call->setDoesNotReturn();
944  CGF.Builder.CreateUnreachable();
945 }
946 
947 llvm::Value *MicrosoftCXXABI::EmitTypeid(CodeGenFunction &CGF,
948  QualType SrcRecordTy,
949  Address ThisPtr,
950  llvm::Type *StdTypeInfoPtrTy) {
951  std::tie(ThisPtr, std::ignore, std::ignore) =
952  performBaseAdjustment(CGF, ThisPtr, SrcRecordTy);
953  llvm::CallBase *Typeid = emitRTtypeidCall(CGF, ThisPtr.getPointer());
954  return CGF.Builder.CreateBitCast(Typeid, StdTypeInfoPtrTy);
955 }
956 
957 bool MicrosoftCXXABI::shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
958  QualType SrcRecordTy) {
959  const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
960  return SrcIsPtr &&
961  !getContext().getASTRecordLayout(SrcDecl).hasExtendableVFPtr();
962 }
963 
964 llvm::Value *MicrosoftCXXABI::EmitDynamicCastCall(
965  CodeGenFunction &CGF, Address This, QualType SrcRecordTy,
966  QualType DestTy, QualType DestRecordTy, llvm::BasicBlock *CastEnd) {
967  llvm::Type *DestLTy = CGF.ConvertType(DestTy);
968 
969  llvm::Value *SrcRTTI =
971  llvm::Value *DestRTTI =
972  CGF.CGM.GetAddrOfRTTIDescriptor(DestRecordTy.getUnqualifiedType());
973 
975  std::tie(This, Offset, std::ignore) =
976  performBaseAdjustment(CGF, This, SrcRecordTy);
977  llvm::Value *ThisPtr = This.getPointer();
978  Offset = CGF.Builder.CreateTrunc(Offset, CGF.Int32Ty);
979 
980  // PVOID __RTDynamicCast(
981  // PVOID inptr,
982  // LONG VfDelta,
983  // PVOID SrcType,
984  // PVOID TargetType,
985  // BOOL isReference)
986  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy, CGF.Int32Ty, CGF.Int8PtrTy,
987  CGF.Int8PtrTy, CGF.Int32Ty};
988  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
989  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
990  "__RTDynamicCast");
991  llvm::Value *Args[] = {
992  ThisPtr, Offset, SrcRTTI, DestRTTI,
993  llvm::ConstantInt::get(CGF.Int32Ty, DestTy->isReferenceType())};
994  ThisPtr = CGF.EmitRuntimeCallOrInvoke(Function, Args);
995  return CGF.Builder.CreateBitCast(ThisPtr, DestLTy);
996 }
997 
998 llvm::Value *
999 MicrosoftCXXABI::EmitDynamicCastToVoid(CodeGenFunction &CGF, Address Value,
1000  QualType SrcRecordTy,
1001  QualType DestTy) {
1002  std::tie(Value, std::ignore, std::ignore) =
1003  performBaseAdjustment(CGF, Value, SrcRecordTy);
1004 
1005  // PVOID __RTCastToVoid(
1006  // PVOID inptr)
1007  llvm::Type *ArgTypes[] = {CGF.Int8PtrTy};
1008  llvm::FunctionCallee Function = CGF.CGM.CreateRuntimeFunction(
1009  llvm::FunctionType::get(CGF.Int8PtrTy, ArgTypes, false),
1010  "__RTCastToVoid");
1011  llvm::Value *Args[] = {Value.getPointer()};
1012  return CGF.EmitRuntimeCall(Function, Args);
1013 }
1014 
1015 bool MicrosoftCXXABI::EmitBadCastCall(CodeGenFunction &CGF) {
1016  return false;
1017 }
1018 
1019 llvm::Value *MicrosoftCXXABI::GetVirtualBaseClassOffset(
1020  CodeGenFunction &CGF, Address This, const CXXRecordDecl *ClassDecl,
1021  const CXXRecordDecl *BaseClassDecl) {
1022  const ASTContext &Context = getContext();
1023  int64_t VBPtrChars =
1024  Context.getASTRecordLayout(ClassDecl).getVBPtrOffset().getQuantity();
1025  llvm::Value *VBPtrOffset = llvm::ConstantInt::get(CGM.PtrDiffTy, VBPtrChars);
1026  CharUnits IntSize = Context.getTypeSizeInChars(Context.IntTy);
1027  CharUnits VBTableChars =
1028  IntSize *
1029  CGM.getMicrosoftVTableContext().getVBTableIndex(ClassDecl, BaseClassDecl);
1030  llvm::Value *VBTableOffset =
1031  llvm::ConstantInt::get(CGM.IntTy, VBTableChars.getQuantity());
1032 
1033  llvm::Value *VBPtrToNewBase =
1034  GetVBaseOffsetFromVBPtr(CGF, This, VBPtrOffset, VBTableOffset);
1035  VBPtrToNewBase =
1036  CGF.Builder.CreateSExtOrBitCast(VBPtrToNewBase, CGM.PtrDiffTy);
1037  return CGF.Builder.CreateNSWAdd(VBPtrOffset, VBPtrToNewBase);
1038 }
1039 
1040 bool MicrosoftCXXABI::HasThisReturn(GlobalDecl GD) const {
1041  return isa<CXXConstructorDecl>(GD.getDecl());
1042 }
1043 
1044 static bool isDeletingDtor(GlobalDecl GD) {
1045  return isa<CXXDestructorDecl>(GD.getDecl()) &&
1046  GD.getDtorType() == Dtor_Deleting;
1047 }
1048 
1049 bool MicrosoftCXXABI::hasMostDerivedReturn(GlobalDecl GD) const {
1050  return isDeletingDtor(GD);
1051 }
1052 
1053 static bool IsSizeGreaterThan128(const CXXRecordDecl *RD) {
1054  return RD->getASTContext().getTypeSize(RD->getTypeForDecl()) > 128;
1055 }
1056 
1058  // For AArch64, we use the C++14 definition of an aggregate, so we also
1059  // check for:
1060  // No private or protected non static data members.
1061  // No base classes
1062  // No virtual functions
1063  // Additionally, we need to ensure that there is a trivial copy assignment
1064  // operator, a trivial destructor and no user-provided constructors.
1065  if (RD->hasProtectedFields() || RD->hasPrivateFields())
1066  return true;
1067  if (RD->getNumBases() > 0)
1068  return true;
1069  if (RD->isPolymorphic())
1070  return true;
1071  if (RD->hasNonTrivialCopyAssignment())
1072  return true;
1073  for (const CXXConstructorDecl *Ctor : RD->ctors())
1074  if (Ctor->isUserProvided())
1075  return true;
1076  if (RD->hasNonTrivialDestructor())
1077  return true;
1078  return false;
1079 }
1080 
1082  const CXXRecordDecl *RD = FI.getReturnType()->getAsCXXRecordDecl();
1083  if (!RD)
1084  return false;
1085 
1086  bool isAArch64 = CGM.getTarget().getTriple().isAArch64();
1087  bool isSimple = !isAArch64 || !hasMicrosoftABIRestrictions(RD);
1088  bool isIndirectReturn =
1089  isAArch64 ? (!RD->canPassInRegisters() ||
1091  : !RD->isPOD();
1092  bool isInstanceMethod = FI.isInstanceMethod();
1093 
1094  if (isIndirectReturn || !isSimple || isInstanceMethod) {
1095  CharUnits Align = CGM.getContext().getTypeAlignInChars(FI.getReturnType());
1096  FI.getReturnInfo() = ABIArgInfo::getIndirect(Align, /*ByVal=*/false);
1097  FI.getReturnInfo().setSRetAfterThis(isInstanceMethod);
1098 
1099  FI.getReturnInfo().setInReg(isAArch64 &&
1100  !(isSimple && IsSizeGreaterThan128(RD)));
1101 
1102  return true;
1103  }
1104 
1105  // Otherwise, use the C ABI rules.
1106  return false;
1107 }
1108 
1109 llvm::BasicBlock *
1110 MicrosoftCXXABI::EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
1111  const CXXRecordDecl *RD) {
1112  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1113  assert(IsMostDerivedClass &&
1114  "ctor for a class with virtual bases must have an implicit parameter");
1115  llvm::Value *IsCompleteObject =
1116  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1117 
1118  llvm::BasicBlock *CallVbaseCtorsBB = CGF.createBasicBlock("ctor.init_vbases");
1119  llvm::BasicBlock *SkipVbaseCtorsBB = CGF.createBasicBlock("ctor.skip_vbases");
1120  CGF.Builder.CreateCondBr(IsCompleteObject,
1121  CallVbaseCtorsBB, SkipVbaseCtorsBB);
1122 
1123  CGF.EmitBlock(CallVbaseCtorsBB);
1124 
1125  // Fill in the vbtable pointers here.
1126  EmitVBPtrStores(CGF, RD);
1127 
1128  // CGF will put the base ctor calls in this basic block for us later.
1129 
1130  return SkipVbaseCtorsBB;
1131 }
1132 
1133 llvm::BasicBlock *
1134 MicrosoftCXXABI::EmitDtorCompleteObjectHandler(CodeGenFunction &CGF) {
1135  llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
1136  assert(IsMostDerivedClass &&
1137  "ctor for a class with virtual bases must have an implicit parameter");
1138  llvm::Value *IsCompleteObject =
1139  CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
1140 
1141  llvm::BasicBlock *CallVbaseDtorsBB = CGF.createBasicBlock("Dtor.dtor_vbases");
1142  llvm::BasicBlock *SkipVbaseDtorsBB = CGF.createBasicBlock("Dtor.skip_vbases");
1143  CGF.Builder.CreateCondBr(IsCompleteObject,
1144  CallVbaseDtorsBB, SkipVbaseDtorsBB);
1145 
1146  CGF.EmitBlock(CallVbaseDtorsBB);
1147  // CGF will put the base dtor calls in this basic block for us later.
1148 
1149  return SkipVbaseDtorsBB;
1150 }
1151 
1152 void MicrosoftCXXABI::initializeHiddenVirtualInheritanceMembers(
1153  CodeGenFunction &CGF, const CXXRecordDecl *RD) {
1154  // In most cases, an override for a vbase virtual method can adjust
1155  // the "this" parameter by applying a constant offset.
1156  // However, this is not enough while a constructor or a destructor of some
1157  // class X is being executed if all the following conditions are met:
1158  // - X has virtual bases, (1)
1159  // - X overrides a virtual method M of a vbase Y, (2)
1160  // - X itself is a vbase of the most derived class.
1161  //
1162  // If (1) and (2) are true, the vtorDisp for vbase Y is a hidden member of X
1163  // which holds the extra amount of "this" adjustment we must do when we use
1164  // the X vftables (i.e. during X ctor or dtor).
1165  // Outside the ctors and dtors, the values of vtorDisps are zero.
1166 
1167  const ASTRecordLayout &Layout = getContext().getASTRecordLayout(RD);
1168  typedef ASTRecordLayout::VBaseOffsetsMapTy VBOffsets;
1169  const VBOffsets &VBaseMap = Layout.getVBaseOffsetsMap();
1170  CGBuilderTy &Builder = CGF.Builder;
1171 
1172  unsigned AS = getThisAddress(CGF).getAddressSpace();
1173  llvm::Value *Int8This = nullptr; // Initialize lazily.
1174 
1175  for (const CXXBaseSpecifier &S : RD->vbases()) {
1176  const CXXRecordDecl *VBase = S.getType()->getAsCXXRecordDecl();
1177  auto I = VBaseMap.find(VBase);
1178  assert(I != VBaseMap.end());
1179  if (!I->second.hasVtorDisp())
1180  continue;
1181 
1182  llvm::Value *VBaseOffset =
1183  GetVirtualBaseClassOffset(CGF, getThisAddress(CGF), RD, VBase);
1184  uint64_t ConstantVBaseOffset = I->second.VBaseOffset.getQuantity();
1185 
1186  // vtorDisp_for_vbase = vbptr[vbase_idx] - offsetof(RD, vbase).
1187  llvm::Value *VtorDispValue = Builder.CreateSub(
1188  VBaseOffset, llvm::ConstantInt::get(CGM.PtrDiffTy, ConstantVBaseOffset),
1189  "vtordisp.value");
1190  VtorDispValue = Builder.CreateTruncOrBitCast(VtorDispValue, CGF.Int32Ty);
1191 
1192  if (!Int8This)
1193  Int8This = Builder.CreateBitCast(getThisValue(CGF),
1194  CGF.Int8Ty->getPointerTo(AS));
1195  llvm::Value *VtorDispPtr = Builder.CreateInBoundsGEP(Int8This, VBaseOffset);
1196  // vtorDisp is always the 32-bits before the vbase in the class layout.
1197  VtorDispPtr = Builder.CreateConstGEP1_32(VtorDispPtr, -4);
1198  VtorDispPtr = Builder.CreateBitCast(
1199  VtorDispPtr, CGF.Int32Ty->getPointerTo(AS), "vtordisp.ptr");
1200 
1201  Builder.CreateAlignedStore(VtorDispValue, VtorDispPtr,
1203  }
1204 }
1205 
1206 static bool hasDefaultCXXMethodCC(ASTContext &Context,
1207  const CXXMethodDecl *MD) {
1208  CallingConv ExpectedCallingConv = Context.getDefaultCallingConvention(
1209  /*IsVariadic=*/false, /*IsCXXMethod=*/true);
1210  CallingConv ActualCallingConv =
1211  MD->getType()->getAs<FunctionProtoType>()->getCallConv();
1212  return ExpectedCallingConv == ActualCallingConv;
1213 }
1214 
1215 void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
1216  // There's only one constructor type in this ABI.
1217  CGM.EmitGlobal(GlobalDecl(D, Ctor_Complete));
1218 
1219  // Exported default constructors either have a simple call-site where they use
1220  // the typical calling convention and have a single 'this' pointer for an
1221  // argument -or- they get a wrapper function which appropriately thunks to the
1222  // real default constructor. This thunk is the default constructor closure.
1223  if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor())
1224  if (!hasDefaultCXXMethodCC(getContext(), D) || D->getNumParams() != 0) {
1225  llvm::Function *Fn = getAddrOfCXXCtorClosure(D, Ctor_DefaultClosure);
1226  Fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
1227  CGM.setGVProperties(Fn, D);
1228  }
1229 }
1230 
1231 void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF,
1232  const CXXRecordDecl *RD) {
1233  Address This = getThisAddress(CGF);
1234  This = CGF.Builder.CreateElementBitCast(This, CGM.Int8Ty, "this.int8");
1235  const ASTContext &Context = getContext();
1236  const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
1237 
1238  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
1239  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
1240  const std::unique_ptr<VPtrInfo> &VBT = (*VBGlobals.VBTables)[I];
1241  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
1242  const ASTRecordLayout &SubobjectLayout =
1243  Context.getASTRecordLayout(VBT->IntroducingObject);
1244  CharUnits Offs = VBT->NonVirtualOffset;
1245  Offs += SubobjectLayout.getVBPtrOffset();
1246  if (VBT->getVBaseWithVPtr())
1247  Offs += Layout.getVBaseClassOffset(VBT->getVBaseWithVPtr());
1248  Address VBPtr = CGF.Builder.CreateConstInBoundsByteGEP(This, Offs);
1249  llvm::Value *GVPtr =
1250  CGF.Builder.CreateConstInBoundsGEP2_32(GV->getValueType(), GV, 0, 0);
1251  VBPtr = CGF.Builder.CreateElementBitCast(VBPtr, GVPtr->getType(),
1252  "vbptr." + VBT->ObjectWithVPtr->getName());
1253  CGF.Builder.CreateStore(GVPtr, VBPtr);
1254  }
1255 }
1256 
1258 MicrosoftCXXABI::buildStructorSignature(GlobalDecl GD,
1259  SmallVectorImpl<CanQualType> &ArgTys) {
1260  AddedStructorArgs Added;
1261  // TODO: 'for base' flag
1262  if (isa<CXXDestructorDecl>(GD.getDecl()) &&
1263  GD.getDtorType() == Dtor_Deleting) {
1264  // The scalar deleting destructor takes an implicit int parameter.
1265  ArgTys.push_back(getContext().IntTy);
1266  ++Added.Suffix;
1267  }
1268  auto *CD = dyn_cast<CXXConstructorDecl>(GD.getDecl());
1269  if (!CD)
1270  return Added;
1271 
1272  // All parameters are already in place except is_most_derived, which goes
1273  // after 'this' if it's variadic and last if it's not.
1274 
1275  const CXXRecordDecl *Class = CD->getParent();
1276  const FunctionProtoType *FPT = CD->getType()->castAs<FunctionProtoType>();
1277  if (Class->getNumVBases()) {
1278  if (FPT->isVariadic()) {
1279  ArgTys.insert(ArgTys.begin() + 1, getContext().IntTy);
1280  ++Added.Prefix;
1281  } else {
1282  ArgTys.push_back(getContext().IntTy);
1283  ++Added.Suffix;
1284  }
1285  }
1286 
1287  return Added;
1288 }
1289 
1290 void MicrosoftCXXABI::setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
1291  const CXXDestructorDecl *Dtor,
1292  CXXDtorType DT) const {
1293  // Deleting destructor variants are never imported or exported. Give them the
1294  // default storage class.
1295  if (DT == Dtor_Deleting) {
1296  GV->setDLLStorageClass(llvm::GlobalValue::DefaultStorageClass);
1297  } else {
1298  const NamedDecl *ND = Dtor;
1299  CGM.setDLLImportDLLExport(GV, ND);
1300  }
1301 }
1302 
1303 llvm::GlobalValue::LinkageTypes MicrosoftCXXABI::getCXXDestructorLinkage(
1304  GVALinkage Linkage, const CXXDestructorDecl *Dtor, CXXDtorType DT) const {
1305  // Internal things are always internal, regardless of attributes. After this,
1306  // we know the thunk is externally visible.
1307  if (Linkage == GVA_Internal)
1309 
1310  switch (DT) {
1311  case Dtor_Base:
1312  // The base destructor most closely tracks the user-declared constructor, so
1313  // we delegate back to the normal declarator case.
1314  return CGM.getLLVMLinkageForDeclarator(Dtor, Linkage,
1315  /*IsConstantVariable=*/false);
1316  case Dtor_Complete:
1317  // The complete destructor is like an inline function, but it may be
1318  // imported and therefore must be exported as well. This requires changing
1319  // the linkage if a DLL attribute is present.
1320  if (Dtor->hasAttr<DLLExportAttr>())
1321  return llvm::GlobalValue::WeakODRLinkage;
1322  if (Dtor->hasAttr<DLLImportAttr>())
1323  return llvm::GlobalValue::AvailableExternallyLinkage;
1324  return llvm::GlobalValue::LinkOnceODRLinkage;
1325  case Dtor_Deleting:
1326  // Deleting destructors are like inline functions. They have vague linkage
1327  // and are emitted everywhere they are used. They are internal if the class
1328  // is internal.
1329  return llvm::GlobalValue::LinkOnceODRLinkage;
1330  case Dtor_Comdat:
1331  llvm_unreachable("MS C++ ABI does not support comdat dtors");
1332  }
1333  llvm_unreachable("invalid dtor type");
1334 }
1335 
1336 void MicrosoftCXXABI::EmitCXXDestructors(const CXXDestructorDecl *D) {
1337  // The TU defining a dtor is only guaranteed to emit a base destructor. All
1338  // other destructor variants are delegating thunks.
1339  CGM.EmitGlobal(GlobalDecl(D, Dtor_Base));
1340 }
1341 
1342 CharUnits
1343 MicrosoftCXXABI::getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
1344  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1345 
1346  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1347  // Complete destructors take a pointer to the complete object as a
1348  // parameter, thus don't need this adjustment.
1349  if (GD.getDtorType() == Dtor_Complete)
1350  return CharUnits();
1351 
1352  // There's no Dtor_Base in vftable but it shares the this adjustment with
1353  // the deleting one, so look it up instead.
1354  GD = GlobalDecl(DD, Dtor_Deleting);
1355  }
1356 
1358  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(GD);
1359  CharUnits Adjustment = ML.VFPtrOffset;
1360 
1361  // Normal virtual instance methods need to adjust from the vfptr that first
1362  // defined the virtual method to the virtual base subobject, but destructors
1363  // do not. The vector deleting destructor thunk applies this adjustment for
1364  // us if necessary.
1365  if (isa<CXXDestructorDecl>(MD))
1366  Adjustment = CharUnits::Zero();
1367 
1368  if (ML.VBase) {
1369  const ASTRecordLayout &DerivedLayout =
1370  getContext().getASTRecordLayout(MD->getParent());
1371  Adjustment += DerivedLayout.getVBaseClassOffset(ML.VBase);
1372  }
1373 
1374  return Adjustment;
1375 }
1376 
1377 Address MicrosoftCXXABI::adjustThisArgumentForVirtualFunctionCall(
1378  CodeGenFunction &CGF, GlobalDecl GD, Address This,
1379  bool VirtualCall) {
1380  if (!VirtualCall) {
1381  // If the call of a virtual function is not virtual, we just have to
1382  // compensate for the adjustment the virtual function does in its prologue.
1383  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(GD);
1384  if (Adjustment.isZero())
1385  return This;
1386 
1387  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
1388  assert(Adjustment.isPositive());
1389  return CGF.Builder.CreateConstByteGEP(This, Adjustment);
1390  }
1391 
1392  const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
1393 
1394  GlobalDecl LookupGD = GD;
1395  if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1396  // Complete dtors take a pointer to the complete object,
1397  // thus don't need adjustment.
1398  if (GD.getDtorType() == Dtor_Complete)
1399  return This;
1400 
1401  // There's only Dtor_Deleting in vftable but it shares the this adjustment
1402  // with the base one, so look up the deleting one instead.
1403  LookupGD = GlobalDecl(DD, Dtor_Deleting);
1404  }
1406  CGM.getMicrosoftVTableContext().getMethodVFTableLocation(LookupGD);
1407 
1408  CharUnits StaticOffset = ML.VFPtrOffset;
1409 
1410  // Base destructors expect 'this' to point to the beginning of the base
1411  // subobject, not the first vfptr that happens to contain the virtual dtor.
1412  // However, we still need to apply the virtual base adjustment.
1413  if (isa<CXXDestructorDecl>(MD) && GD.getDtorType() == Dtor_Base)
1414  StaticOffset = CharUnits::Zero();
1415 
1416  Address Result = This;
1417  if (ML.VBase) {
1418  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1419 
1420  const CXXRecordDecl *Derived = MD->getParent();
1421  const CXXRecordDecl *VBase = ML.VBase;
1422  llvm::Value *VBaseOffset =
1423  GetVirtualBaseClassOffset(CGF, Result, Derived, VBase);
1424  llvm::Value *VBasePtr =
1425  CGF.Builder.CreateInBoundsGEP(Result.getPointer(), VBaseOffset);
1426  CharUnits VBaseAlign =
1427  CGF.CGM.getVBaseAlignment(Result.getAlignment(), Derived, VBase);
1428  Result = Address(VBasePtr, VBaseAlign);
1429  }
1430  if (!StaticOffset.isZero()) {
1431  assert(StaticOffset.isPositive());
1432  Result = CGF.Builder.CreateElementBitCast(Result, CGF.Int8Ty);
1433  if (ML.VBase) {
1434  // Non-virtual adjustment might result in a pointer outside the allocated
1435  // object, e.g. if the final overrider class is laid out after the virtual
1436  // base that declares a method in the most derived class.
1437  // FIXME: Update the code that emits this adjustment in thunks prologues.
1438  Result = CGF.Builder.CreateConstByteGEP(Result, StaticOffset);
1439  } else {
1440  Result = CGF.Builder.CreateConstInBoundsByteGEP(Result, StaticOffset);
1441  }
1442  }
1443  return Result;
1444 }
1445 
1446 void MicrosoftCXXABI::addImplicitStructorParams(CodeGenFunction &CGF,
1447  QualType &ResTy,
1448  FunctionArgList &Params) {
1449  ASTContext &Context = getContext();
1450  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1451  assert(isa<CXXConstructorDecl>(MD) || isa<CXXDestructorDecl>(MD));
1452  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1453  auto *IsMostDerived = ImplicitParamDecl::Create(
1454  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1455  &Context.Idents.get("is_most_derived"), Context.IntTy,
1457  // The 'most_derived' parameter goes second if the ctor is variadic and last
1458  // if it's not. Dtors can't be variadic.
1459  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
1460  if (FPT->isVariadic())
1461  Params.insert(Params.begin() + 1, IsMostDerived);
1462  else
1463  Params.push_back(IsMostDerived);
1464  getStructorImplicitParamDecl(CGF) = IsMostDerived;
1465  } else if (isDeletingDtor(CGF.CurGD)) {
1466  auto *ShouldDelete = ImplicitParamDecl::Create(
1467  Context, /*DC=*/nullptr, CGF.CurGD.getDecl()->getLocation(),
1468  &Context.Idents.get("should_call_delete"), Context.IntTy,
1470  Params.push_back(ShouldDelete);
1471  getStructorImplicitParamDecl(CGF) = ShouldDelete;
1472  }
1473 }
1474 
1475 void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
1476  // Naked functions have no prolog.
1477  if (CGF.CurFuncDecl && CGF.CurFuncDecl->hasAttr<NakedAttr>())
1478  return;
1479 
1480  // Overridden virtual methods of non-primary bases need to adjust the incoming
1481  // 'this' pointer in the prologue. In this hierarchy, C::b will subtract
1482  // sizeof(void*) to adjust from B* to C*:
1483  // struct A { virtual void a(); };
1484  // struct B { virtual void b(); };
1485  // struct C : A, B { virtual void b(); };
1486  //
1487  // Leave the value stored in the 'this' alloca unadjusted, so that the
1488  // debugger sees the unadjusted value. Microsoft debuggers require this, and
1489  // will apply the ThisAdjustment in the method type information.
1490  // FIXME: Do something better for DWARF debuggers, which won't expect this,
1491  // without making our codegen depend on debug info settings.
1492  llvm::Value *This = loadIncomingCXXThis(CGF);
1493  const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
1494  if (!CGF.CurFuncIsThunk && MD->isVirtual()) {
1495  CharUnits Adjustment = getVirtualFunctionPrologueThisAdjustment(CGF.CurGD);
1496  if (!Adjustment.isZero()) {
1497  unsigned AS = cast<llvm::PointerType>(This->getType())->getAddressSpace();
1498  llvm::Type *charPtrTy = CGF.Int8Ty->getPointerTo(AS),
1499  *thisTy = This->getType();
1500  This = CGF.Builder.CreateBitCast(This, charPtrTy);
1501  assert(Adjustment.isPositive());
1502  This = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, This,
1503  -Adjustment.getQuantity());
1504  This = CGF.Builder.CreateBitCast(This, thisTy, "this.adjusted");
1505  }
1506  }
1507  setCXXABIThisValue(CGF, This);
1508 
1509  // If this is a function that the ABI specifies returns 'this', initialize
1510  // the return slot to 'this' at the start of the function.
1511  //
1512  // Unlike the setting of return types, this is done within the ABI
1513  // implementation instead of by clients of CGCXXABI because:
1514  // 1) getThisValue is currently protected
1515  // 2) in theory, an ABI could implement 'this' returns some other way;
1516  // HasThisReturn only specifies a contract, not the implementation
1517  if (HasThisReturn(CGF.CurGD))
1518  CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
1519  else if (hasMostDerivedReturn(CGF.CurGD))
1520  CGF.Builder.CreateStore(CGF.EmitCastToVoidPtr(getThisValue(CGF)),
1521  CGF.ReturnValue);
1522 
1523  if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
1524  assert(getStructorImplicitParamDecl(CGF) &&
1525  "no implicit parameter for a constructor with virtual bases?");
1526  getStructorImplicitParamValue(CGF)
1527  = CGF.Builder.CreateLoad(
1528  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1529  "is_most_derived");
1530  }
1531 
1532  if (isDeletingDtor(CGF.CurGD)) {
1533  assert(getStructorImplicitParamDecl(CGF) &&
1534  "no implicit parameter for a deleting destructor?");
1535  getStructorImplicitParamValue(CGF)
1536  = CGF.Builder.CreateLoad(
1537  CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
1538  "should_call_delete");
1539  }
1540 }
1541 
1542 CGCXXABI::AddedStructorArgs MicrosoftCXXABI::addImplicitConstructorArgs(
1544  bool ForVirtualBase, bool Delegating, CallArgList &Args) {
1545  assert(Type == Ctor_Complete || Type == Ctor_Base);
1546 
1547  // Check if we need a 'most_derived' parameter.
1548  if (!D->getParent()->getNumVBases())
1549  return AddedStructorArgs{};
1550 
1551  // Add the 'most_derived' argument second if we are variadic or last if not.
1552  const FunctionProtoType *FPT = D->getType()->castAs<FunctionProtoType>();
1553  llvm::Value *MostDerivedArg;
1554  if (Delegating) {
1555  MostDerivedArg = getStructorImplicitParamValue(CGF);
1556  } else {
1557  MostDerivedArg = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete);
1558  }
1559  RValue RV = RValue::get(MostDerivedArg);
1560  if (FPT->isVariadic()) {
1561  Args.insert(Args.begin() + 1, CallArg(RV, getContext().IntTy));
1562  return AddedStructorArgs::prefix(1);
1563  }
1564  Args.add(RV, getContext().IntTy);
1565  return AddedStructorArgs::suffix(1);
1566 }
1567 
1568 void MicrosoftCXXABI::EmitDestructorCall(CodeGenFunction &CGF,
1569  const CXXDestructorDecl *DD,
1570  CXXDtorType Type, bool ForVirtualBase,
1571  bool Delegating, Address This,
1572  QualType ThisTy) {
1573  // Use the base destructor variant in place of the complete destructor variant
1574  // if the class has no virtual bases. This effectively implements some of the
1575  // -mconstructor-aliases optimization, but as part of the MS C++ ABI.
1576  if (Type == Dtor_Complete && DD->getParent()->getNumVBases() == 0)
1577  Type = Dtor_Base;
1578 
1579  GlobalDecl GD(DD, Type);
1580  CGCallee Callee = CGCallee::forDirect(CGM.getAddrOfCXXStructor(GD), GD);
1581 
1582  if (DD->isVirtual()) {
1583  assert(Type != CXXDtorType::Dtor_Deleting &&
1584  "The deleting destructor should only be called via a virtual call");
1585  This = adjustThisArgumentForVirtualFunctionCall(CGF, GlobalDecl(DD, Type),
1586  This, false);
1587  }
1588 
1589  llvm::BasicBlock *BaseDtorEndBB = nullptr;
1590  if (ForVirtualBase && isa<CXXConstructorDecl>(CGF.CurCodeDecl)) {
1591  BaseDtorEndBB = EmitDtorCompleteObjectHandler(CGF);
1592  }
1593 
1594  CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
1595  /*ImplicitParam=*/nullptr,
1596  /*ImplicitParamTy=*/QualType(), nullptr);
1597  if (BaseDtorEndBB) {
1598  // Complete object handler should continue to be the remaining
1599  CGF.Builder.CreateBr(BaseDtorEndBB);
1600  CGF.EmitBlock(BaseDtorEndBB);
1601  }
1602 }
1603 
1604 void MicrosoftCXXABI::emitVTableTypeMetadata(const VPtrInfo &Info,
1605  const CXXRecordDecl *RD,
1606  llvm::GlobalVariable *VTable) {
1607  if (!CGM.getCodeGenOpts().LTOUnit)
1608  return;
1609 
1610  // The location of the first virtual function pointer in the virtual table,
1611  // aka the "address point" on Itanium. This is at offset 0 if RTTI is
1612  // disabled, or sizeof(void*) if RTTI is enabled.
1613  CharUnits AddressPoint =
1614  getContext().getLangOpts().RTTIData
1615  ? getContext().toCharUnitsFromBits(
1616  getContext().getTargetInfo().getPointerWidth(0))
1617  : CharUnits::Zero();
1618 
1619  if (Info.PathToIntroducingObject.empty()) {
1620  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1621  return;
1622  }
1623 
1624  // Add a bitset entry for the least derived base belonging to this vftable.
1625  CGM.AddVTableTypeMetadata(VTable, AddressPoint,
1626  Info.PathToIntroducingObject.back());
1627 
1628  // Add a bitset entry for each derived class that is laid out at the same
1629  // offset as the least derived base.
1630  for (unsigned I = Info.PathToIntroducingObject.size() - 1; I != 0; --I) {
1631  const CXXRecordDecl *DerivedRD = Info.PathToIntroducingObject[I - 1];
1632  const CXXRecordDecl *BaseRD = Info.PathToIntroducingObject[I];
1633 
1634  const ASTRecordLayout &Layout =
1635  getContext().getASTRecordLayout(DerivedRD);
1636  CharUnits Offset;
1637  auto VBI = Layout.getVBaseOffsetsMap().find(BaseRD);
1638  if (VBI == Layout.getVBaseOffsetsMap().end())
1639  Offset = Layout.getBaseClassOffset(BaseRD);
1640  else
1641  Offset = VBI->second.VBaseOffset;
1642  if (!Offset.isZero())
1643  return;
1644  CGM.AddVTableTypeMetadata(VTable, AddressPoint, DerivedRD);
1645  }
1646 
1647  // Finally do the same for the most derived class.
1648  if (Info.FullOffsetInMDC.isZero())
1649  CGM.AddVTableTypeMetadata(VTable, AddressPoint, RD);
1650 }
1651 
1652 void MicrosoftCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
1653  const CXXRecordDecl *RD) {
1654  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1655  const VPtrInfoVector &VFPtrs = VFTContext.getVFPtrOffsets(RD);
1656 
1657  for (const std::unique_ptr<VPtrInfo>& Info : VFPtrs) {
1658  llvm::GlobalVariable *VTable = getAddrOfVTable(RD, Info->FullOffsetInMDC);
1659  if (VTable->hasInitializer())
1660  continue;
1661 
1662  const VTableLayout &VTLayout =
1663  VFTContext.getVFTableLayout(RD, Info->FullOffsetInMDC);
1664 
1665  llvm::Constant *RTTI = nullptr;
1666  if (any_of(VTLayout.vtable_components(),
1667  [](const VTableComponent &VTC) { return VTC.isRTTIKind(); }))
1668  RTTI = getMSCompleteObjectLocator(RD, *Info);
1669 
1670  ConstantInitBuilder Builder(CGM);
1671  auto Components = Builder.beginStruct();
1672  CGVT.createVTableInitializer(Components, VTLayout, RTTI);
1673  Components.finishAndSetAsInitializer(VTable);
1674 
1675  emitVTableTypeMetadata(*Info, RD, VTable);
1676  }
1677 }
1678 
1679 bool MicrosoftCXXABI::isVirtualOffsetNeededForVTableField(
1681  return Vptr.NearestVBase != nullptr;
1682 }
1683 
1684 llvm::Value *MicrosoftCXXABI::getVTableAddressPointInStructor(
1685  CodeGenFunction &CGF, const CXXRecordDecl *VTableClass, BaseSubobject Base,
1686  const CXXRecordDecl *NearestVBase) {
1687  llvm::Constant *VTableAddressPoint = getVTableAddressPoint(Base, VTableClass);
1688  if (!VTableAddressPoint) {
1689  assert(Base.getBase()->getNumVBases() &&
1690  !getContext().getASTRecordLayout(Base.getBase()).hasOwnVFPtr());
1691  }
1692  return VTableAddressPoint;
1693 }
1694 
1696  const CXXRecordDecl *RD, const VPtrInfo &VFPtr,
1697  SmallString<256> &Name) {
1698  llvm::raw_svector_ostream Out(Name);
1699  MangleContext.mangleCXXVFTable(RD, VFPtr.MangledPath, Out);
1700 }
1701 
1702 llvm::Constant *
1703 MicrosoftCXXABI::getVTableAddressPoint(BaseSubobject Base,
1704  const CXXRecordDecl *VTableClass) {
1705  (void)getAddrOfVTable(VTableClass, Base.getBaseOffset());
1706  VFTableIdTy ID(VTableClass, Base.getBaseOffset());
1707  return VFTablesMap[ID];
1708 }
1709 
1710 llvm::Constant *MicrosoftCXXABI::getVTableAddressPointForConstExpr(
1711  BaseSubobject Base, const CXXRecordDecl *VTableClass) {
1712  llvm::Constant *VFTable = getVTableAddressPoint(Base, VTableClass);
1713  assert(VFTable && "Couldn't find a vftable for the given base?");
1714  return VFTable;
1715 }
1716 
1717 llvm::GlobalVariable *MicrosoftCXXABI::getAddrOfVTable(const CXXRecordDecl *RD,
1718  CharUnits VPtrOffset) {
1719  // getAddrOfVTable may return 0 if asked to get an address of a vtable which
1720  // shouldn't be used in the given record type. We want to cache this result in
1721  // VFTablesMap, thus a simple zero check is not sufficient.
1722 
1723  VFTableIdTy ID(RD, VPtrOffset);
1724  VTablesMapTy::iterator I;
1725  bool Inserted;
1726  std::tie(I, Inserted) = VTablesMap.insert(std::make_pair(ID, nullptr));
1727  if (!Inserted)
1728  return I->second;
1729 
1730  llvm::GlobalVariable *&VTable = I->second;
1731 
1732  MicrosoftVTableContext &VTContext = CGM.getMicrosoftVTableContext();
1733  const VPtrInfoVector &VFPtrs = VTContext.getVFPtrOffsets(RD);
1734 
1735  if (DeferredVFTables.insert(RD).second) {
1736  // We haven't processed this record type before.
1737  // Queue up this vtable for possible deferred emission.
1738  CGM.addDeferredVTable(RD);
1739 
1740 #ifndef NDEBUG
1741  // Create all the vftables at once in order to make sure each vftable has
1742  // a unique mangled name.
1743  llvm::StringSet<> ObservedMangledNames;
1744  for (size_t J = 0, F = VFPtrs.size(); J != F; ++J) {
1745  SmallString<256> Name;
1746  mangleVFTableName(getMangleContext(), RD, *VFPtrs[J], Name);
1747  if (!ObservedMangledNames.insert(Name.str()).second)
1748  llvm_unreachable("Already saw this mangling before?");
1749  }
1750 #endif
1751  }
1752 
1753  const std::unique_ptr<VPtrInfo> *VFPtrI = std::find_if(
1754  VFPtrs.begin(), VFPtrs.end(), [&](const std::unique_ptr<VPtrInfo>& VPI) {
1755  return VPI->FullOffsetInMDC == VPtrOffset;
1756  });
1757  if (VFPtrI == VFPtrs.end()) {
1758  VFTablesMap[ID] = nullptr;
1759  return nullptr;
1760  }
1761  const std::unique_ptr<VPtrInfo> &VFPtr = *VFPtrI;
1762 
1763  SmallString<256> VFTableName;
1764  mangleVFTableName(getMangleContext(), RD, *VFPtr, VFTableName);
1765 
1766  // Classes marked __declspec(dllimport) need vftables generated on the
1767  // import-side in order to support features like constexpr. No other
1768  // translation unit relies on the emission of the local vftable, translation
1769  // units are expected to generate them as needed.
1770  //
1771  // Because of this unique behavior, we maintain this logic here instead of
1772  // getVTableLinkage.
1773  llvm::GlobalValue::LinkageTypes VFTableLinkage =
1774  RD->hasAttr<DLLImportAttr>() ? llvm::GlobalValue::LinkOnceODRLinkage
1775  : CGM.getVTableLinkage(RD);
1776  bool VFTableComesFromAnotherTU =
1777  llvm::GlobalValue::isAvailableExternallyLinkage(VFTableLinkage) ||
1778  llvm::GlobalValue::isExternalLinkage(VFTableLinkage);
1779  bool VTableAliasIsRequred =
1780  !VFTableComesFromAnotherTU && getContext().getLangOpts().RTTIData;
1781 
1782  if (llvm::GlobalValue *VFTable =
1783  CGM.getModule().getNamedGlobal(VFTableName)) {
1784  VFTablesMap[ID] = VFTable;
1785  VTable = VTableAliasIsRequred
1786  ? cast<llvm::GlobalVariable>(
1787  cast<llvm::GlobalAlias>(VFTable)->getBaseObject())
1788  : cast<llvm::GlobalVariable>(VFTable);
1789  return VTable;
1790  }
1791 
1792  const VTableLayout &VTLayout =
1793  VTContext.getVFTableLayout(RD, VFPtr->FullOffsetInMDC);
1794  llvm::GlobalValue::LinkageTypes VTableLinkage =
1795  VTableAliasIsRequred ? llvm::GlobalValue::PrivateLinkage : VFTableLinkage;
1796 
1797  StringRef VTableName = VTableAliasIsRequred ? StringRef() : VFTableName.str();
1798 
1799  llvm::Type *VTableType = CGM.getVTables().getVTableType(VTLayout);
1800 
1801  // Create a backing variable for the contents of VTable. The VTable may
1802  // or may not include space for a pointer to RTTI data.
1803  llvm::GlobalValue *VFTable;
1804  VTable = new llvm::GlobalVariable(CGM.getModule(), VTableType,
1805  /*isConstant=*/true, VTableLinkage,
1806  /*Initializer=*/nullptr, VTableName);
1807  VTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1808 
1809  llvm::Comdat *C = nullptr;
1810  if (!VFTableComesFromAnotherTU &&
1811  (llvm::GlobalValue::isWeakForLinker(VFTableLinkage) ||
1812  (llvm::GlobalValue::isLocalLinkage(VFTableLinkage) &&
1813  VTableAliasIsRequred)))
1814  C = CGM.getModule().getOrInsertComdat(VFTableName.str());
1815 
1816  // Only insert a pointer into the VFTable for RTTI data if we are not
1817  // importing it. We never reference the RTTI data directly so there is no
1818  // need to make room for it.
1819  if (VTableAliasIsRequred) {
1820  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.Int32Ty, 0),
1821  llvm::ConstantInt::get(CGM.Int32Ty, 0),
1822  llvm::ConstantInt::get(CGM.Int32Ty, 1)};
1823  // Create a GEP which points just after the first entry in the VFTable,
1824  // this should be the location of the first virtual method.
1825  llvm::Constant *VTableGEP = llvm::ConstantExpr::getInBoundsGetElementPtr(
1826  VTable->getValueType(), VTable, GEPIndices);
1827  if (llvm::GlobalValue::isWeakForLinker(VFTableLinkage)) {
1828  VFTableLinkage = llvm::GlobalValue::ExternalLinkage;
1829  if (C)
1830  C->setSelectionKind(llvm::Comdat::Largest);
1831  }
1832  VFTable = llvm::GlobalAlias::create(CGM.Int8PtrTy,
1833  /*AddressSpace=*/0, VFTableLinkage,
1834  VFTableName.str(), VTableGEP,
1835  &CGM.getModule());
1836  VFTable->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
1837  } else {
1838  // We don't need a GlobalAlias to be a symbol for the VTable if we won't
1839  // be referencing any RTTI data.
1840  // The GlobalVariable will end up being an appropriate definition of the
1841  // VFTable.
1842  VFTable = VTable;
1843  }
1844  if (C)
1845  VTable->setComdat(C);
1846 
1847  if (RD->hasAttr<DLLExportAttr>())
1848  VFTable->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
1849 
1850  VFTablesMap[ID] = VFTable;
1851  return VTable;
1852 }
1853 
1854 CGCallee MicrosoftCXXABI::getVirtualFunctionPointer(CodeGenFunction &CGF,
1855  GlobalDecl GD,
1856  Address This,
1857  llvm::Type *Ty,
1858  SourceLocation Loc) {
1859  CGBuilderTy &Builder = CGF.Builder;
1860 
1861  Ty = Ty->getPointerTo()->getPointerTo();
1862  Address VPtr =
1863  adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1864 
1865  auto *MethodDecl = cast<CXXMethodDecl>(GD.getDecl());
1866  llvm::Value *VTable = CGF.GetVTablePtr(VPtr, Ty, MethodDecl->getParent());
1867 
1868  MicrosoftVTableContext &VFTContext = CGM.getMicrosoftVTableContext();
1869  MethodVFTableLocation ML = VFTContext.getMethodVFTableLocation(GD);
1870 
1871  // Compute the identity of the most derived class whose virtual table is
1872  // located at the MethodVFTableLocation ML.
1873  auto getObjectWithVPtr = [&] {
1874  return llvm::find_if(VFTContext.getVFPtrOffsets(
1875  ML.VBase ? ML.VBase : MethodDecl->getParent()),
1876  [&](const std::unique_ptr<VPtrInfo> &Info) {
1877  return Info->FullOffsetInMDC == ML.VFPtrOffset;
1878  })
1879  ->get()
1880  ->ObjectWithVPtr;
1881  };
1882 
1883  llvm::Value *VFunc;
1884  if (CGF.ShouldEmitVTableTypeCheckedLoad(MethodDecl->getParent())) {
1885  VFunc = CGF.EmitVTableTypeCheckedLoad(
1886  getObjectWithVPtr(), VTable,
1887  ML.Index * CGM.getContext().getTargetInfo().getPointerWidth(0) / 8);
1888  } else {
1889  if (CGM.getCodeGenOpts().PrepareForLTO)
1890  CGF.EmitTypeMetadataCodeForVCall(getObjectWithVPtr(), VTable, Loc);
1891 
1892  llvm::Value *VFuncPtr =
1893  Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
1894  VFunc = Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
1895  }
1896 
1897  CGCallee Callee(GD, VFunc);
1898  return Callee;
1899 }
1900 
1901 llvm::Value *MicrosoftCXXABI::EmitVirtualDestructorCall(
1902  CodeGenFunction &CGF, const CXXDestructorDecl *Dtor, CXXDtorType DtorType,
1903  Address This, DeleteOrMemberCallExpr E) {
1904  auto *CE = E.dyn_cast<const CXXMemberCallExpr *>();
1905  auto *D = E.dyn_cast<const CXXDeleteExpr *>();
1906  assert((CE != nullptr) ^ (D != nullptr));
1907  assert(CE == nullptr || CE->arg_begin() == CE->arg_end());
1908  assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
1909 
1910  // We have only one destructor in the vftable but can get both behaviors
1911  // by passing an implicit int parameter.
1912  GlobalDecl GD(Dtor, Dtor_Deleting);
1913  const CGFunctionInfo *FInfo =
1914  &CGM.getTypes().arrangeCXXStructorDeclaration(GD);
1915  llvm::FunctionType *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
1916  CGCallee Callee = CGCallee::forVirtual(CE, GD, This, Ty);
1917 
1918  ASTContext &Context = getContext();
1919  llvm::Value *ImplicitParam = llvm::ConstantInt::get(
1920  llvm::IntegerType::getInt32Ty(CGF.getLLVMContext()),
1921  DtorType == Dtor_Deleting);
1922 
1923  QualType ThisTy;
1924  if (CE) {
1925  ThisTy = CE->getObjectType();
1926  } else {
1927  ThisTy = D->getDestroyedType();
1928  }
1929 
1930  This = adjustThisArgumentForVirtualFunctionCall(CGF, GD, This, true);
1931  RValue RV = CGF.EmitCXXDestructorCall(GD, Callee, This.getPointer(), ThisTy,
1932  ImplicitParam, Context.IntTy, CE);
1933  return RV.getScalarVal();
1934 }
1935 
1936 const VBTableGlobals &
1937 MicrosoftCXXABI::enumerateVBTables(const CXXRecordDecl *RD) {
1938  // At this layer, we can key the cache off of a single class, which is much
1939  // easier than caching each vbtable individually.
1940  llvm::DenseMap<const CXXRecordDecl*, VBTableGlobals>::iterator Entry;
1941  bool Added;
1942  std::tie(Entry, Added) =
1943  VBTablesMap.insert(std::make_pair(RD, VBTableGlobals()));
1944  VBTableGlobals &VBGlobals = Entry->second;
1945  if (!Added)
1946  return VBGlobals;
1947 
1948  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
1949  VBGlobals.VBTables = &Context.enumerateVBTables(RD);
1950 
1951  // Cache the globals for all vbtables so we don't have to recompute the
1952  // mangled names.
1953  llvm::GlobalVariable::LinkageTypes Linkage = CGM.getVTableLinkage(RD);
1954  for (VPtrInfoVector::const_iterator I = VBGlobals.VBTables->begin(),
1955  E = VBGlobals.VBTables->end();
1956  I != E; ++I) {
1957  VBGlobals.Globals.push_back(getAddrOfVBTable(**I, RD, Linkage));
1958  }
1959 
1960  return VBGlobals;
1961 }
1962 
1963 llvm::Function *
1964 MicrosoftCXXABI::EmitVirtualMemPtrThunk(const CXXMethodDecl *MD,
1965  const MethodVFTableLocation &ML) {
1966  assert(!isa<CXXConstructorDecl>(MD) && !isa<CXXDestructorDecl>(MD) &&
1967  "can't form pointers to ctors or virtual dtors");
1968 
1969  // Calculate the mangled name.
1970  SmallString<256> ThunkName;
1971  llvm::raw_svector_ostream Out(ThunkName);
1972  getMangleContext().mangleVirtualMemPtrThunk(MD, ML, Out);
1973 
1974  // If the thunk has been generated previously, just return it.
1975  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
1976  return cast<llvm::Function>(GV);
1977 
1978  // Create the llvm::Function.
1979  const CGFunctionInfo &FnInfo =
1980  CGM.getTypes().arrangeUnprototypedMustTailThunk(MD);
1981  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
1982  llvm::Function *ThunkFn =
1984  ThunkName.str(), &CGM.getModule());
1985  assert(ThunkFn->getName() == ThunkName && "name was uniqued!");
1986 
1987  ThunkFn->setLinkage(MD->isExternallyVisible()
1988  ? llvm::GlobalValue::LinkOnceODRLinkage
1990  if (MD->isExternallyVisible())
1991  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
1992 
1993  CGM.SetLLVMFunctionAttributes(MD, FnInfo, ThunkFn);
1994  CGM.SetLLVMFunctionAttributesForDefinition(MD, ThunkFn);
1995 
1996  // Add the "thunk" attribute so that LLVM knows that the return type is
1997  // meaningless. These thunks can be used to call functions with differing
1998  // return types, and the caller is required to cast the prototype
1999  // appropriately to extract the correct value.
2000  ThunkFn->addFnAttr("thunk");
2001 
2002  // These thunks can be compared, so they are not unnamed.
2003  ThunkFn->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
2004 
2005  // Start codegen.
2006  CodeGenFunction CGF(CGM);
2007  CGF.CurGD = GlobalDecl(MD);
2008  CGF.CurFuncIsThunk = true;
2009 
2010  // Build FunctionArgs, but only include the implicit 'this' parameter
2011  // declaration.
2012  FunctionArgList FunctionArgs;
2013  buildThisParam(CGF, FunctionArgs);
2014 
2015  // Start defining the function.
2016  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
2017  FunctionArgs, MD->getLocation(), SourceLocation());
2018  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
2019 
2020  // Load the vfptr and then callee from the vftable. The callee should have
2021  // adjusted 'this' so that the vfptr is at offset zero.
2022  llvm::Value *VTable = CGF.GetVTablePtr(
2023  getThisAddress(CGF), ThunkTy->getPointerTo()->getPointerTo(), MD->getParent());
2024 
2025  llvm::Value *VFuncPtr =
2026  CGF.Builder.CreateConstInBoundsGEP1_64(VTable, ML.Index, "vfn");
2027  llvm::Value *Callee =
2028  CGF.Builder.CreateAlignedLoad(VFuncPtr, CGF.getPointerAlign());
2029 
2030  CGF.EmitMustTailThunk(MD, getThisValue(CGF), {ThunkTy, Callee});
2031 
2032  return ThunkFn;
2033 }
2034 
2035 void MicrosoftCXXABI::emitVirtualInheritanceTables(const CXXRecordDecl *RD) {
2036  const VBTableGlobals &VBGlobals = enumerateVBTables(RD);
2037  for (unsigned I = 0, E = VBGlobals.VBTables->size(); I != E; ++I) {
2038  const std::unique_ptr<VPtrInfo>& VBT = (*VBGlobals.VBTables)[I];
2039  llvm::GlobalVariable *GV = VBGlobals.Globals[I];
2040  if (GV->isDeclaration())
2041  emitVBTableDefinition(*VBT, RD, GV);
2042  }
2043 }
2044 
2045 llvm::GlobalVariable *
2046 MicrosoftCXXABI::getAddrOfVBTable(const VPtrInfo &VBT, const CXXRecordDecl *RD,
2047  llvm::GlobalVariable::LinkageTypes Linkage) {
2048  SmallString<256> OutName;
2049  llvm::raw_svector_ostream Out(OutName);
2050  getMangleContext().mangleCXXVBTable(RD, VBT.MangledPath, Out);
2051  StringRef Name = OutName.str();
2052 
2053  llvm::ArrayType *VBTableType =
2054  llvm::ArrayType::get(CGM.IntTy, 1 + VBT.ObjectWithVPtr->getNumVBases());
2055 
2056  assert(!CGM.getModule().getNamedGlobal(Name) &&
2057  "vbtable with this name already exists: mangling bug?");
2058  CharUnits Alignment =
2059  CGM.getContext().getTypeAlignInChars(CGM.getContext().IntTy);
2060  llvm::GlobalVariable *GV = CGM.CreateOrReplaceCXXRuntimeVariable(
2061  Name, VBTableType, Linkage, Alignment.getQuantity());
2062  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2063 
2064  if (RD->hasAttr<DLLImportAttr>())
2065  GV->setDLLStorageClass(llvm::GlobalValue::DLLImportStorageClass);
2066  else if (RD->hasAttr<DLLExportAttr>())
2067  GV->setDLLStorageClass(llvm::GlobalValue::DLLExportStorageClass);
2068 
2069  if (!GV->hasExternalLinkage())
2070  emitVBTableDefinition(VBT, RD, GV);
2071 
2072  return GV;
2073 }
2074 
2075 void MicrosoftCXXABI::emitVBTableDefinition(const VPtrInfo &VBT,
2076  const CXXRecordDecl *RD,
2077  llvm::GlobalVariable *GV) const {
2078  const CXXRecordDecl *ObjectWithVPtr = VBT.ObjectWithVPtr;
2079 
2080  assert(RD->getNumVBases() && ObjectWithVPtr->getNumVBases() &&
2081  "should only emit vbtables for classes with vbtables");
2082 
2083  const ASTRecordLayout &BaseLayout =
2084  getContext().getASTRecordLayout(VBT.IntroducingObject);
2085  const ASTRecordLayout &DerivedLayout = getContext().getASTRecordLayout(RD);
2086 
2087  SmallVector<llvm::Constant *, 4> Offsets(1 + ObjectWithVPtr->getNumVBases(),
2088  nullptr);
2089 
2090  // The offset from ObjectWithVPtr's vbptr to itself always leads.
2091  CharUnits VBPtrOffset = BaseLayout.getVBPtrOffset();
2092  Offsets[0] = llvm::ConstantInt::get(CGM.IntTy, -VBPtrOffset.getQuantity());
2093 
2094  MicrosoftVTableContext &Context = CGM.getMicrosoftVTableContext();
2095  for (const auto &I : ObjectWithVPtr->vbases()) {
2096  const CXXRecordDecl *VBase = I.getType()->getAsCXXRecordDecl();
2097  CharUnits Offset = DerivedLayout.getVBaseClassOffset(VBase);
2098  assert(!Offset.isNegative());
2099 
2100  // Make it relative to the subobject vbptr.
2101  CharUnits CompleteVBPtrOffset = VBT.NonVirtualOffset + VBPtrOffset;
2102  if (VBT.getVBaseWithVPtr())
2103  CompleteVBPtrOffset +=
2104  DerivedLayout.getVBaseClassOffset(VBT.getVBaseWithVPtr());
2105  Offset -= CompleteVBPtrOffset;
2106 
2107  unsigned VBIndex = Context.getVBTableIndex(ObjectWithVPtr, VBase);
2108  assert(Offsets[VBIndex] == nullptr && "The same vbindex seen twice?");
2109  Offsets[VBIndex] = llvm::ConstantInt::get(CGM.IntTy, Offset.getQuantity());
2110  }
2111 
2112  assert(Offsets.size() ==
2113  cast<llvm::ArrayType>(cast<llvm::PointerType>(GV->getType())
2114  ->getElementType())->getNumElements());
2115  llvm::ArrayType *VBTableType =
2116  llvm::ArrayType::get(CGM.IntTy, Offsets.size());
2117  llvm::Constant *Init = llvm::ConstantArray::get(VBTableType, Offsets);
2118  GV->setInitializer(Init);
2119 
2120  if (RD->hasAttr<DLLImportAttr>())
2121  GV->setLinkage(llvm::GlobalVariable::AvailableExternallyLinkage);
2122 }
2123 
2124 llvm::Value *MicrosoftCXXABI::performThisAdjustment(CodeGenFunction &CGF,
2125  Address This,
2126  const ThisAdjustment &TA) {
2127  if (TA.isEmpty())
2128  return This.getPointer();
2129 
2130  This = CGF.Builder.CreateElementBitCast(This, CGF.Int8Ty);
2131 
2132  llvm::Value *V;
2133  if (TA.Virtual.isEmpty()) {
2134  V = This.getPointer();
2135  } else {
2136  assert(TA.Virtual.Microsoft.VtordispOffset < 0);
2137  // Adjust the this argument based on the vtordisp value.
2138  Address VtorDispPtr =
2141  VtorDispPtr = CGF.Builder.CreateElementBitCast(VtorDispPtr, CGF.Int32Ty);
2142  llvm::Value *VtorDisp = CGF.Builder.CreateLoad(VtorDispPtr, "vtordisp");
2143  V = CGF.Builder.CreateGEP(This.getPointer(),
2144  CGF.Builder.CreateNeg(VtorDisp));
2145 
2146  // Unfortunately, having applied the vtordisp means that we no
2147  // longer really have a known alignment for the vbptr step.
2148  // We'll assume the vbptr is pointer-aligned.
2149 
2150  if (TA.Virtual.Microsoft.VBPtrOffset) {
2151  // If the final overrider is defined in a virtual base other than the one
2152  // that holds the vfptr, we have to use a vtordispex thunk which looks up
2153  // the vbtable of the derived class.
2154  assert(TA.Virtual.Microsoft.VBPtrOffset > 0);
2155  assert(TA.Virtual.Microsoft.VBOffsetOffset >= 0);
2156  llvm::Value *VBPtr;
2157  llvm::Value *VBaseOffset =
2158  GetVBaseOffsetFromVBPtr(CGF, Address(V, CGF.getPointerAlign()),
2160  TA.Virtual.Microsoft.VBOffsetOffset, &VBPtr);
2161  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2162  }
2163  }
2164 
2165  if (TA.NonVirtual) {
2166  // Non-virtual adjustment might result in a pointer outside the allocated
2167  // object, e.g. if the final overrider class is laid out after the virtual
2168  // base that declares a method in the most derived class.
2169  V = CGF.Builder.CreateConstGEP1_32(V, TA.NonVirtual);
2170  }
2171 
2172  // Don't need to bitcast back, the call CodeGen will handle this.
2173  return V;
2174 }
2175 
2176 llvm::Value *
2177 MicrosoftCXXABI::performReturnAdjustment(CodeGenFunction &CGF, Address Ret,
2178  const ReturnAdjustment &RA) {
2179  if (RA.isEmpty())
2180  return Ret.getPointer();
2181 
2182  auto OrigTy = Ret.getType();
2183  Ret = CGF.Builder.CreateElementBitCast(Ret, CGF.Int8Ty);
2184 
2185  llvm::Value *V = Ret.getPointer();
2186  if (RA.Virtual.Microsoft.VBIndex) {
2187  assert(RA.Virtual.Microsoft.VBIndex > 0);
2188  int32_t IntSize = CGF.getIntSize().getQuantity();
2189  llvm::Value *VBPtr;
2190  llvm::Value *VBaseOffset =
2191  GetVBaseOffsetFromVBPtr(CGF, Ret, RA.Virtual.Microsoft.VBPtrOffset,
2192  IntSize * RA.Virtual.Microsoft.VBIndex, &VBPtr);
2193  V = CGF.Builder.CreateInBoundsGEP(VBPtr, VBaseOffset);
2194  }
2195 
2196  if (RA.NonVirtual)
2197  V = CGF.Builder.CreateConstInBoundsGEP1_32(CGF.Int8Ty, V, RA.NonVirtual);
2198 
2199  // Cast back to the original type.
2200  return CGF.Builder.CreateBitCast(V, OrigTy);
2201 }
2202 
2203 bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
2204  QualType elementType) {
2205  // Microsoft seems to completely ignore the possibility of a
2206  // two-argument usual deallocation function.
2207  return elementType.isDestructedType();
2208 }
2209 
2210 bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) {
2211  // Microsoft seems to completely ignore the possibility of a
2212  // two-argument usual deallocation function.
2213  return expr->getAllocatedType().isDestructedType();
2214 }
2215 
2216 CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) {
2217  // The array cookie is always a size_t; we then pad that out to the
2218  // alignment of the element type.
2219  ASTContext &Ctx = getContext();
2220  return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
2221  Ctx.getTypeAlignInChars(type));
2222 }
2223 
2224 llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
2225  Address allocPtr,
2226  CharUnits cookieSize) {
2227  Address numElementsPtr =
2228  CGF.Builder.CreateElementBitCast(allocPtr, CGF.SizeTy);
2229  return CGF.Builder.CreateLoad(numElementsPtr);
2230 }
2231 
2232 Address MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
2233  Address newPtr,
2234  llvm::Value *numElements,
2235  const CXXNewExpr *expr,
2236  QualType elementType) {
2237  assert(requiresArrayCookie(expr));
2238 
2239  // The size of the cookie.
2240  CharUnits cookieSize = getArrayCookieSizeImpl(elementType);
2241 
2242  // Compute an offset to the cookie.
2243  Address cookiePtr = newPtr;
2244 
2245  // Write the number of elements into the appropriate slot.
2246  Address numElementsPtr
2247  = CGF.Builder.CreateElementBitCast(cookiePtr, CGF.SizeTy);
2248  CGF.Builder.CreateStore(numElements, numElementsPtr);
2249 
2250  // Finally, compute a pointer to the actual data buffer by skipping
2251  // over the cookie completely.
2252  return CGF.Builder.CreateConstInBoundsByteGEP(newPtr, cookieSize);
2253 }
2254 
2256  llvm::FunctionCallee Dtor,
2257  llvm::Constant *Addr) {
2258  // Create a function which calls the destructor.
2259  llvm::Constant *DtorStub = CGF.createAtExitStub(VD, Dtor, Addr);
2260 
2261  // extern "C" int __tlregdtor(void (*f)(void));
2262  llvm::FunctionType *TLRegDtorTy = llvm::FunctionType::get(
2263  CGF.IntTy, DtorStub->getType(), /*isVarArg=*/false);
2264 
2265  llvm::FunctionCallee TLRegDtor = CGF.CGM.CreateRuntimeFunction(
2266  TLRegDtorTy, "__tlregdtor", llvm::AttributeList(), /*Local=*/true);
2267  if (llvm::Function *TLRegDtorFn =
2268  dyn_cast<llvm::Function>(TLRegDtor.getCallee()))
2269  TLRegDtorFn->setDoesNotThrow();
2270 
2271  CGF.EmitNounwindRuntimeCall(TLRegDtor, DtorStub);
2272 }
2273 
2274 void MicrosoftCXXABI::registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
2275  llvm::FunctionCallee Dtor,
2276  llvm::Constant *Addr) {
2277  if (D.isNoDestroy(CGM.getContext()))
2278  return;
2279 
2280  if (D.getTLSKind())
2281  return emitGlobalDtorWithTLRegDtor(CGF, D, Dtor, Addr);
2282 
2283  // The default behavior is to use atexit.
2284  CGF.registerGlobalDtorWithAtExit(D, Dtor, Addr);
2285 }
2286 
2287 void MicrosoftCXXABI::EmitThreadLocalInitFuncs(
2288  CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
2289  ArrayRef<llvm::Function *> CXXThreadLocalInits,
2290  ArrayRef<const VarDecl *> CXXThreadLocalInitVars) {
2291  if (CXXThreadLocalInits.empty())
2292  return;
2293 
2294  CGM.AppendLinkerOptions(CGM.getTarget().getTriple().getArch() ==
2295  llvm::Triple::x86
2296  ? "/include:___dyn_tls_init@12"
2297  : "/include:__dyn_tls_init");
2298 
2299  // This will create a GV in the .CRT$XDU section. It will point to our
2300  // initialization function. The CRT will call all of these function
2301  // pointers at start-up time and, eventually, at thread-creation time.
2302  auto AddToXDU = [&CGM](llvm::Function *InitFunc) {
2303  llvm::GlobalVariable *InitFuncPtr = new llvm::GlobalVariable(
2304  CGM.getModule(), InitFunc->getType(), /*isConstant=*/true,
2306  Twine(InitFunc->getName(), "$initializer$"));
2307  InitFuncPtr->setSection(".CRT$XDU");
2308  // This variable has discardable linkage, we have to add it to @llvm.used to
2309  // ensure it won't get discarded.
2310  CGM.addUsedGlobal(InitFuncPtr);
2311  return InitFuncPtr;
2312  };
2313 
2314  std::vector<llvm::Function *> NonComdatInits;
2315  for (size_t I = 0, E = CXXThreadLocalInitVars.size(); I != E; ++I) {
2316  llvm::GlobalVariable *GV = cast<llvm::GlobalVariable>(
2317  CGM.GetGlobalValue(CGM.getMangledName(CXXThreadLocalInitVars[I])));
2318  llvm::Function *F = CXXThreadLocalInits[I];
2319 
2320  // If the GV is already in a comdat group, then we have to join it.
2321  if (llvm::Comdat *C = GV->getComdat())
2322  AddToXDU(F)->setComdat(C);
2323  else
2324  NonComdatInits.push_back(F);
2325  }
2326 
2327  if (!NonComdatInits.empty()) {
2328  llvm::FunctionType *FTy =
2329  llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
2330  llvm::Function *InitFunc = CGM.CreateGlobalInitOrDestructFunction(
2331  FTy, "__tls_init", CGM.getTypes().arrangeNullaryFunction(),
2332  SourceLocation(), /*TLS=*/true);
2333  CodeGenFunction(CGM).GenerateCXXGlobalInitFunc(InitFunc, NonComdatInits);
2334 
2335  AddToXDU(InitFunc);
2336  }
2337 }
2338 
2339 LValue MicrosoftCXXABI::EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
2340  const VarDecl *VD,
2341  QualType LValType) {
2342  CGF.CGM.ErrorUnsupported(VD, "thread wrappers");
2343  return LValue();
2344 }
2345 
2347  StringRef VarName("_Init_thread_epoch");
2348  CharUnits Align = CGM.getIntAlign();
2349  if (auto *GV = CGM.getModule().getNamedGlobal(VarName))
2350  return ConstantAddress(GV, Align);
2351  auto *GV = new llvm::GlobalVariable(
2352  CGM.getModule(), CGM.IntTy,
2353  /*isConstant=*/false, llvm::GlobalVariable::ExternalLinkage,
2354  /*Initializer=*/nullptr, VarName,
2355  /*InsertBefore=*/nullptr, llvm::GlobalVariable::GeneralDynamicTLSModel);
2356  GV->setAlignment(Align.getQuantity());
2357  return ConstantAddress(GV, Align);
2358 }
2359 
2360 static llvm::FunctionCallee getInitThreadHeaderFn(CodeGenModule &CGM) {
2361  llvm::FunctionType *FTy =
2362  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2363  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2364  return CGM.CreateRuntimeFunction(
2365  FTy, "_Init_thread_header",
2366  llvm::AttributeList::get(CGM.getLLVMContext(),
2367  llvm::AttributeList::FunctionIndex,
2368  llvm::Attribute::NoUnwind),
2369  /*Local=*/true);
2370 }
2371 
2372 static llvm::FunctionCallee getInitThreadFooterFn(CodeGenModule &CGM) {
2373  llvm::FunctionType *FTy =
2374  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2375  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2376  return CGM.CreateRuntimeFunction(
2377  FTy, "_Init_thread_footer",
2378  llvm::AttributeList::get(CGM.getLLVMContext(),
2379  llvm::AttributeList::FunctionIndex,
2380  llvm::Attribute::NoUnwind),
2381  /*Local=*/true);
2382 }
2383 
2384 static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM) {
2385  llvm::FunctionType *FTy =
2386  llvm::FunctionType::get(llvm::Type::getVoidTy(CGM.getLLVMContext()),
2387  CGM.IntTy->getPointerTo(), /*isVarArg=*/false);
2388  return CGM.CreateRuntimeFunction(
2389  FTy, "_Init_thread_abort",
2390  llvm::AttributeList::get(CGM.getLLVMContext(),
2391  llvm::AttributeList::FunctionIndex,
2392  llvm::Attribute::NoUnwind),
2393  /*Local=*/true);
2394 }
2395 
2396 namespace {
2397 struct ResetGuardBit final : EHScopeStack::Cleanup {
2398  Address Guard;
2399  unsigned GuardNum;
2400  ResetGuardBit(Address Guard, unsigned GuardNum)
2401  : Guard(Guard), GuardNum(GuardNum) {}
2402 
2403  void Emit(CodeGenFunction &CGF, Flags flags) override {
2404  // Reset the bit in the mask so that the static variable may be
2405  // reinitialized.
2406  CGBuilderTy &Builder = CGF.Builder;
2407  llvm::LoadInst *LI = Builder.CreateLoad(Guard);
2408  llvm::ConstantInt *Mask =
2409  llvm::ConstantInt::get(CGF.IntTy, ~(1ULL << GuardNum));
2410  Builder.CreateStore(Builder.CreateAnd(LI, Mask), Guard);
2411  }
2412 };
2413 
2414 struct CallInitThreadAbort final : EHScopeStack::Cleanup {
2415  llvm::Value *Guard;
2416  CallInitThreadAbort(Address Guard) : Guard(Guard.getPointer()) {}
2417 
2418  void Emit(CodeGenFunction &CGF, Flags flags) override {
2419  // Calling _Init_thread_abort will reset the guard's state.
2421  }
2422 };
2423 }
2424 
2425 void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
2426  llvm::GlobalVariable *GV,
2427  bool PerformInit) {
2428  // MSVC only uses guards for static locals.
2429  if (!D.isStaticLocal()) {
2430  assert(GV->hasWeakLinkage() || GV->hasLinkOnceLinkage());
2431  // GlobalOpt is allowed to discard the initializer, so use linkonce_odr.
2432  llvm::Function *F = CGF.CurFn;
2433  F->setLinkage(llvm::GlobalValue::LinkOnceODRLinkage);
2434  F->setComdat(CGM.getModule().getOrInsertComdat(F->getName()));
2435  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2436  return;
2437  }
2438 
2439  bool ThreadlocalStatic = D.getTLSKind();
2440  bool ThreadsafeStatic = getContext().getLangOpts().ThreadsafeStatics;
2441 
2442  // Thread-safe static variables which aren't thread-specific have a
2443  // per-variable guard.
2444  bool HasPerVariableGuard = ThreadsafeStatic && !ThreadlocalStatic;
2445 
2446  CGBuilderTy &Builder = CGF.Builder;
2447  llvm::IntegerType *GuardTy = CGF.Int32Ty;
2448  llvm::ConstantInt *Zero = llvm::ConstantInt::get(GuardTy, 0);
2449  CharUnits GuardAlign = CharUnits::fromQuantity(4);
2450 
2451  // Get the guard variable for this function if we have one already.
2452  GuardInfo *GI = nullptr;
2453  if (ThreadlocalStatic)
2454  GI = &ThreadLocalGuardVariableMap[D.getDeclContext()];
2455  else if (!ThreadsafeStatic)
2456  GI = &GuardVariableMap[D.getDeclContext()];
2457 
2458  llvm::GlobalVariable *GuardVar = GI ? GI->Guard : nullptr;
2459  unsigned GuardNum;
2460  if (D.isExternallyVisible()) {
2461  // Externally visible variables have to be numbered in Sema to properly
2462  // handle unreachable VarDecls.
2463  GuardNum = getContext().getStaticLocalNumber(&D);
2464  assert(GuardNum > 0);
2465  GuardNum--;
2466  } else if (HasPerVariableGuard) {
2467  GuardNum = ThreadSafeGuardNumMap[D.getDeclContext()]++;
2468  } else {
2469  // Non-externally visible variables are numbered here in CodeGen.
2470  GuardNum = GI->BitIndex++;
2471  }
2472 
2473  if (!HasPerVariableGuard && GuardNum >= 32) {
2474  if (D.isExternallyVisible())
2475  ErrorUnsupportedABI(CGF, "more than 32 guarded initializations");
2476  GuardNum %= 32;
2477  GuardVar = nullptr;
2478  }
2479 
2480  if (!GuardVar) {
2481  // Mangle the name for the guard.
2482  SmallString<256> GuardName;
2483  {
2484  llvm::raw_svector_ostream Out(GuardName);
2485  if (HasPerVariableGuard)
2486  getMangleContext().mangleThreadSafeStaticGuardVariable(&D, GuardNum,
2487  Out);
2488  else
2489  getMangleContext().mangleStaticGuardVariable(&D, Out);
2490  }
2491 
2492  // Create the guard variable with a zero-initializer. Just absorb linkage,
2493  // visibility and dll storage class from the guarded variable.
2494  GuardVar =
2495  new llvm::GlobalVariable(CGM.getModule(), GuardTy, /*isConstant=*/false,
2496  GV->getLinkage(), Zero, GuardName.str());
2497  GuardVar->setVisibility(GV->getVisibility());
2498  GuardVar->setDLLStorageClass(GV->getDLLStorageClass());
2499  GuardVar->setAlignment(GuardAlign.getQuantity());
2500  if (GuardVar->isWeakForLinker())
2501  GuardVar->setComdat(
2502  CGM.getModule().getOrInsertComdat(GuardVar->getName()));
2503  if (D.getTLSKind())
2504  GuardVar->setThreadLocal(true);
2505  if (GI && !HasPerVariableGuard)
2506  GI->Guard = GuardVar;
2507  }
2508 
2509  ConstantAddress GuardAddr(GuardVar, GuardAlign);
2510 
2511  assert(GuardVar->getLinkage() == GV->getLinkage() &&
2512  "static local from the same function had different linkage");
2513 
2514  if (!HasPerVariableGuard) {
2515  // Pseudo code for the test:
2516  // if (!(GuardVar & MyGuardBit)) {
2517  // GuardVar |= MyGuardBit;
2518  // ... initialize the object ...;
2519  // }
2520 
2521  // Test our bit from the guard variable.
2522  llvm::ConstantInt *Bit = llvm::ConstantInt::get(GuardTy, 1ULL << GuardNum);
2523  llvm::LoadInst *LI = Builder.CreateLoad(GuardAddr);
2524  llvm::Value *NeedsInit =
2525  Builder.CreateICmpEQ(Builder.CreateAnd(LI, Bit), Zero);
2526  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2527  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2528  CGF.EmitCXXGuardedInitBranch(NeedsInit, InitBlock, EndBlock,
2530 
2531  // Set our bit in the guard variable and emit the initializer and add a global
2532  // destructor if appropriate.
2533  CGF.EmitBlock(InitBlock);
2534  Builder.CreateStore(Builder.CreateOr(LI, Bit), GuardAddr);
2535  CGF.EHStack.pushCleanup<ResetGuardBit>(EHCleanup, GuardAddr, GuardNum);
2536  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2537  CGF.PopCleanupBlock();
2538  Builder.CreateBr(EndBlock);
2539 
2540  // Continue.
2541  CGF.EmitBlock(EndBlock);
2542  } else {
2543  // Pseudo code for the test:
2544  // if (TSS > _Init_thread_epoch) {
2545  // _Init_thread_header(&TSS);
2546  // if (TSS == -1) {
2547  // ... initialize the object ...;
2548  // _Init_thread_footer(&TSS);
2549  // }
2550  // }
2551  //
2552  // The algorithm is almost identical to what can be found in the appendix
2553  // found in N2325.
2554 
2555  // This BasicBLock determines whether or not we have any work to do.
2556  llvm::LoadInst *FirstGuardLoad = Builder.CreateLoad(GuardAddr);
2557  FirstGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2558  llvm::LoadInst *InitThreadEpoch =
2559  Builder.CreateLoad(getInitThreadEpochPtr(CGM));
2560  llvm::Value *IsUninitialized =
2561  Builder.CreateICmpSGT(FirstGuardLoad, InitThreadEpoch);
2562  llvm::BasicBlock *AttemptInitBlock = CGF.createBasicBlock("init.attempt");
2563  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("init.end");
2564  CGF.EmitCXXGuardedInitBranch(IsUninitialized, AttemptInitBlock, EndBlock,
2566 
2567  // This BasicBlock attempts to determine whether or not this thread is
2568  // responsible for doing the initialization.
2569  CGF.EmitBlock(AttemptInitBlock);
2571  GuardAddr.getPointer());
2572  llvm::LoadInst *SecondGuardLoad = Builder.CreateLoad(GuardAddr);
2573  SecondGuardLoad->setOrdering(llvm::AtomicOrdering::Unordered);
2574  llvm::Value *ShouldDoInit =
2575  Builder.CreateICmpEQ(SecondGuardLoad, getAllOnesInt());
2576  llvm::BasicBlock *InitBlock = CGF.createBasicBlock("init");
2577  Builder.CreateCondBr(ShouldDoInit, InitBlock, EndBlock);
2578 
2579  // Ok, we ended up getting selected as the initializing thread.
2580  CGF.EmitBlock(InitBlock);
2581  CGF.EHStack.pushCleanup<CallInitThreadAbort>(EHCleanup, GuardAddr);
2582  CGF.EmitCXXGlobalVarDeclInit(D, GV, PerformInit);
2583  CGF.PopCleanupBlock();
2585  GuardAddr.getPointer());
2586  Builder.CreateBr(EndBlock);
2587 
2588  CGF.EmitBlock(EndBlock);
2589  }
2590 }
2591 
2592 bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
2593  // Null-ness for function memptrs only depends on the first field, which is
2594  // the function pointer. The rest don't matter, so we can zero initialize.
2595  if (MPT->isMemberFunctionPointer())
2596  return true;
2597 
2598  // The virtual base adjustment field is always -1 for null, so if we have one
2599  // we can't zero initialize. The field offset is sometimes also -1 if 0 is a
2600  // valid field offset.
2601  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2602  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2603  return (!MSInheritanceAttr::hasVBTableOffsetField(Inheritance) &&
2604  RD->nullFieldOffsetIsZero());
2605 }
2606 
2607 llvm::Type *
2608 MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
2609  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2610  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2612  if (MPT->isMemberFunctionPointer())
2613  fields.push_back(CGM.VoidPtrTy); // FunctionPointerOrVirtualThunk
2614  else
2615  fields.push_back(CGM.IntTy); // FieldOffset
2616 
2617  if (MSInheritanceAttr::hasNVOffsetField(MPT->isMemberFunctionPointer(),
2618  Inheritance))
2619  fields.push_back(CGM.IntTy);
2620  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
2621  fields.push_back(CGM.IntTy);
2622  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2623  fields.push_back(CGM.IntTy); // VirtualBaseAdjustmentOffset
2624 
2625  if (fields.size() == 1)
2626  return fields[0];
2627  return llvm::StructType::get(CGM.getLLVMContext(), fields);
2628 }
2629 
2630 void MicrosoftCXXABI::
2631 GetNullMemberPointerFields(const MemberPointerType *MPT,
2633  assert(fields.empty());
2634  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2635  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2636  if (MPT->isMemberFunctionPointer()) {
2637  // FunctionPointerOrVirtualThunk
2638  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2639  } else {
2640  if (RD->nullFieldOffsetIsZero())
2641  fields.push_back(getZeroInt()); // FieldOffset
2642  else
2643  fields.push_back(getAllOnesInt()); // FieldOffset
2644  }
2645 
2646  if (MSInheritanceAttr::hasNVOffsetField(MPT->isMemberFunctionPointer(),
2647  Inheritance))
2648  fields.push_back(getZeroInt());
2649  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
2650  fields.push_back(getZeroInt());
2651  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2652  fields.push_back(getAllOnesInt());
2653 }
2654 
2655 llvm::Constant *
2656 MicrosoftCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
2658  GetNullMemberPointerFields(MPT, fields);
2659  if (fields.size() == 1)
2660  return fields[0];
2661  llvm::Constant *Res = llvm::ConstantStruct::getAnon(fields);
2662  assert(Res->getType() == ConvertMemberPointerType(MPT));
2663  return Res;
2664 }
2665 
2666 llvm::Constant *
2667 MicrosoftCXXABI::EmitFullMemberPointer(llvm::Constant *FirstField,
2668  bool IsMemberFunction,
2669  const CXXRecordDecl *RD,
2670  CharUnits NonVirtualBaseAdjustment,
2671  unsigned VBTableIndex) {
2672  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2673 
2674  // Single inheritance class member pointer are represented as scalars instead
2675  // of aggregates.
2676  if (MSInheritanceAttr::hasOnlyOneField(IsMemberFunction, Inheritance))
2677  return FirstField;
2678 
2680  fields.push_back(FirstField);
2681 
2682  if (MSInheritanceAttr::hasNVOffsetField(IsMemberFunction, Inheritance))
2683  fields.push_back(llvm::ConstantInt::get(
2684  CGM.IntTy, NonVirtualBaseAdjustment.getQuantity()));
2685 
2686  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance)) {
2687  CharUnits Offs = CharUnits::Zero();
2688  if (VBTableIndex)
2689  Offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
2690  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, Offs.getQuantity()));
2691  }
2692 
2693  // The rest of the fields are adjusted by conversions to a more derived class.
2694  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
2695  fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBTableIndex));
2696 
2697  return llvm::ConstantStruct::getAnon(fields);
2698 }
2699 
2700 llvm::Constant *
2701 MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
2702  CharUnits offset) {
2703  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2704  if (RD->getMSInheritanceModel() ==
2705  MSInheritanceAttr::Keyword_virtual_inheritance)
2706  offset -= getContext().getOffsetOfBaseWithVBPtr(RD);
2707  llvm::Constant *FirstField =
2708  llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity());
2709  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/false, RD,
2710  CharUnits::Zero(), /*VBTableIndex=*/0);
2711 }
2712 
2713 llvm::Constant *MicrosoftCXXABI::EmitMemberPointer(const APValue &MP,
2714  QualType MPType) {
2715  const MemberPointerType *DstTy = MPType->castAs<MemberPointerType>();
2716  const ValueDecl *MPD = MP.getMemberPointerDecl();
2717  if (!MPD)
2718  return EmitNullMemberPointer(DstTy);
2719 
2720  ASTContext &Ctx = getContext();
2721  ArrayRef<const CXXRecordDecl *> MemberPointerPath = MP.getMemberPointerPath();
2722 
2723  llvm::Constant *C;
2724  if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MPD)) {
2725  C = EmitMemberFunctionPointer(MD);
2726  } else {
2727  CharUnits FieldOffset = Ctx.toCharUnitsFromBits(Ctx.getFieldOffset(MPD));
2728  C = EmitMemberDataPointer(DstTy, FieldOffset);
2729  }
2730 
2731  if (!MemberPointerPath.empty()) {
2732  const CXXRecordDecl *SrcRD = cast<CXXRecordDecl>(MPD->getDeclContext());
2733  const Type *SrcRecTy = Ctx.getTypeDeclType(SrcRD).getTypePtr();
2734  const MemberPointerType *SrcTy =
2735  Ctx.getMemberPointerType(DstTy->getPointeeType(), SrcRecTy)
2736  ->castAs<MemberPointerType>();
2737 
2738  bool DerivedMember = MP.isMemberPointerToDerivedMember();
2739  SmallVector<const CXXBaseSpecifier *, 4> DerivedToBasePath;
2740  const CXXRecordDecl *PrevRD = SrcRD;
2741  for (const CXXRecordDecl *PathElem : MemberPointerPath) {
2742  const CXXRecordDecl *Base = nullptr;
2743  const CXXRecordDecl *Derived = nullptr;
2744  if (DerivedMember) {
2745  Base = PathElem;
2746  Derived = PrevRD;
2747  } else {
2748  Base = PrevRD;
2749  Derived = PathElem;
2750  }
2751  for (const CXXBaseSpecifier &BS : Derived->bases())
2752  if (BS.getType()->getAsCXXRecordDecl()->getCanonicalDecl() ==
2753  Base->getCanonicalDecl())
2754  DerivedToBasePath.push_back(&BS);
2755  PrevRD = PathElem;
2756  }
2757  assert(DerivedToBasePath.size() == MemberPointerPath.size());
2758 
2759  CastKind CK = DerivedMember ? CK_DerivedToBaseMemberPointer
2760  : CK_BaseToDerivedMemberPointer;
2761  C = EmitMemberPointerConversion(SrcTy, DstTy, CK, DerivedToBasePath.begin(),
2762  DerivedToBasePath.end(), C);
2763  }
2764  return C;
2765 }
2766 
2767 llvm::Constant *
2768 MicrosoftCXXABI::EmitMemberFunctionPointer(const CXXMethodDecl *MD) {
2769  assert(MD->isInstance() && "Member function must not be static!");
2770 
2771  CharUnits NonVirtualBaseAdjustment = CharUnits::Zero();
2773  CodeGenTypes &Types = CGM.getTypes();
2774 
2775  unsigned VBTableIndex = 0;
2776  llvm::Constant *FirstField;
2777  const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
2778  if (!MD->isVirtual()) {
2779  llvm::Type *Ty;
2780  // Check whether the function has a computable LLVM signature.
2781  if (Types.isFuncTypeConvertible(FPT)) {
2782  // The function has a computable LLVM signature; use the correct type.
2783  Ty = Types.GetFunctionType(Types.arrangeCXXMethodDeclaration(MD));
2784  } else {
2785  // Use an arbitrary non-function type to tell GetAddrOfFunction that the
2786  // function type is incomplete.
2787  Ty = CGM.PtrDiffTy;
2788  }
2789  FirstField = CGM.GetAddrOfFunction(MD, Ty);
2790  } else {
2791  auto &VTableContext = CGM.getMicrosoftVTableContext();
2792  MethodVFTableLocation ML = VTableContext.getMethodVFTableLocation(MD);
2793  FirstField = EmitVirtualMemPtrThunk(MD, ML);
2794  // Include the vfptr adjustment if the method is in a non-primary vftable.
2795  NonVirtualBaseAdjustment += ML.VFPtrOffset;
2796  if (ML.VBase)
2797  VBTableIndex = VTableContext.getVBTableIndex(RD, ML.VBase) * 4;
2798  }
2799 
2800  if (VBTableIndex == 0 &&
2801  RD->getMSInheritanceModel() ==
2802  MSInheritanceAttr::Keyword_virtual_inheritance)
2803  NonVirtualBaseAdjustment -= getContext().getOffsetOfBaseWithVBPtr(RD);
2804 
2805  // The rest of the fields are common with data member pointers.
2806  FirstField = llvm::ConstantExpr::getBitCast(FirstField, CGM.VoidPtrTy);
2807  return EmitFullMemberPointer(FirstField, /*IsMemberFunction=*/true, RD,
2808  NonVirtualBaseAdjustment, VBTableIndex);
2809 }
2810 
2811 /// Member pointers are the same if they're either bitwise identical *or* both
2812 /// null. Null-ness for function members is determined by the first field,
2813 /// while for data member pointers we must compare all fields.
2814 llvm::Value *
2815 MicrosoftCXXABI::EmitMemberPointerComparison(CodeGenFunction &CGF,
2816  llvm::Value *L,
2817  llvm::Value *R,
2818  const MemberPointerType *MPT,
2819  bool Inequality) {
2820  CGBuilderTy &Builder = CGF.Builder;
2821 
2822  // Handle != comparisons by switching the sense of all boolean operations.
2823  llvm::ICmpInst::Predicate Eq;
2824  llvm::Instruction::BinaryOps And, Or;
2825  if (Inequality) {
2826  Eq = llvm::ICmpInst::ICMP_NE;
2827  And = llvm::Instruction::Or;
2829  } else {
2830  Eq = llvm::ICmpInst::ICMP_EQ;
2831  And = llvm::Instruction::And;
2832  Or = llvm::Instruction::Or;
2833  }
2834 
2835  // If this is a single field member pointer (single inheritance), this is a
2836  // single icmp.
2837  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
2838  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
2839  if (MSInheritanceAttr::hasOnlyOneField(MPT->isMemberFunctionPointer(),
2840  Inheritance))
2841  return Builder.CreateICmp(Eq, L, R);
2842 
2843  // Compare the first field.
2844  llvm::Value *L0 = Builder.CreateExtractValue(L, 0, "lhs.0");
2845  llvm::Value *R0 = Builder.CreateExtractValue(R, 0, "rhs.0");
2846  llvm::Value *Cmp0 = Builder.CreateICmp(Eq, L0, R0, "memptr.cmp.first");
2847 
2848  // Compare everything other than the first field.
2849  llvm::Value *Res = nullptr;
2850  llvm::StructType *LType = cast<llvm::StructType>(L->getType());
2851  for (unsigned I = 1, E = LType->getNumElements(); I != E; ++I) {
2852  llvm::Value *LF = Builder.CreateExtractValue(L, I);
2853  llvm::Value *RF = Builder.CreateExtractValue(R, I);
2854  llvm::Value *Cmp = Builder.CreateICmp(Eq, LF, RF, "memptr.cmp.rest");
2855  if (Res)
2856  Res = Builder.CreateBinOp(And, Res, Cmp);
2857  else
2858  Res = Cmp;
2859  }
2860 
2861  // Check if the first field is 0 if this is a function pointer.
2862  if (MPT->isMemberFunctionPointer()) {
2863  // (l1 == r1 && ...) || l0 == 0
2864  llvm::Value *Zero = llvm::Constant::getNullValue(L0->getType());
2865  llvm::Value *IsZero = Builder.CreateICmp(Eq, L0, Zero, "memptr.cmp.iszero");
2866  Res = Builder.CreateBinOp(Or, Res, IsZero);
2867  }
2868 
2869  // Combine the comparison of the first field, which must always be true for
2870  // this comparison to succeeed.
2871  return Builder.CreateBinOp(And, Res, Cmp0, "memptr.cmp");
2872 }
2873 
2874 llvm::Value *
2875 MicrosoftCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
2876  llvm::Value *MemPtr,
2877  const MemberPointerType *MPT) {
2878  CGBuilderTy &Builder = CGF.Builder;
2880  // We only need one field for member functions.
2881  if (MPT->isMemberFunctionPointer())
2882  fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
2883  else
2884  GetNullMemberPointerFields(MPT, fields);
2885  assert(!fields.empty());
2886  llvm::Value *FirstField = MemPtr;
2887  if (MemPtr->getType()->isStructTy())
2888  FirstField = Builder.CreateExtractValue(MemPtr, 0);
2889  llvm::Value *Res = Builder.CreateICmpNE(FirstField, fields[0], "memptr.cmp0");
2890 
2891  // For function member pointers, we only need to test the function pointer
2892  // field. The other fields if any can be garbage.
2893  if (MPT->isMemberFunctionPointer())
2894  return Res;
2895 
2896  // Otherwise, emit a series of compares and combine the results.
2897  for (int I = 1, E = fields.size(); I < E; ++I) {
2898  llvm::Value *Field = Builder.CreateExtractValue(MemPtr, I);
2899  llvm::Value *Next = Builder.CreateICmpNE(Field, fields[I], "memptr.cmp");
2900  Res = Builder.CreateOr(Res, Next, "memptr.tobool");
2901  }
2902  return Res;
2903 }
2904 
2905 bool MicrosoftCXXABI::MemberPointerConstantIsNull(const MemberPointerType *MPT,
2906  llvm::Constant *Val) {
2907  // Function pointers are null if the pointer in the first field is null.
2908  if (MPT->isMemberFunctionPointer()) {
2909  llvm::Constant *FirstField = Val->getType()->isStructTy() ?
2910  Val->getAggregateElement(0U) : Val;
2911  return FirstField->isNullValue();
2912  }
2913 
2914  // If it's not a function pointer and it's zero initializable, we can easily
2915  // check zero.
2916  if (isZeroInitializable(MPT) && Val->isNullValue())
2917  return true;
2918 
2919  // Otherwise, break down all the fields for comparison. Hopefully these
2920  // little Constants are reused, while a big null struct might not be.
2922  GetNullMemberPointerFields(MPT, Fields);
2923  if (Fields.size() == 1) {
2924  assert(Val->getType()->isIntegerTy());
2925  return Val == Fields[0];
2926  }
2927 
2928  unsigned I, E;
2929  for (I = 0, E = Fields.size(); I != E; ++I) {
2930  if (Val->getAggregateElement(I) != Fields[I])
2931  break;
2932  }
2933  return I == E;
2934 }
2935 
2936 llvm::Value *
2937 MicrosoftCXXABI::GetVBaseOffsetFromVBPtr(CodeGenFunction &CGF,
2938  Address This,
2939  llvm::Value *VBPtrOffset,
2940  llvm::Value *VBTableOffset,
2941  llvm::Value **VBPtrOut) {
2942  CGBuilderTy &Builder = CGF.Builder;
2943  // Load the vbtable pointer from the vbptr in the instance.
2944  This = Builder.CreateElementBitCast(This, CGM.Int8Ty);
2945  llvm::Value *VBPtr =
2946  Builder.CreateInBoundsGEP(This.getPointer(), VBPtrOffset, "vbptr");
2947  if (VBPtrOut) *VBPtrOut = VBPtr;
2948  VBPtr = Builder.CreateBitCast(VBPtr,
2949  CGM.Int32Ty->getPointerTo(0)->getPointerTo(This.getAddressSpace()));
2950 
2951  CharUnits VBPtrAlign;
2952  if (auto CI = dyn_cast<llvm::ConstantInt>(VBPtrOffset)) {
2953  VBPtrAlign = This.getAlignment().alignmentAtOffset(
2954  CharUnits::fromQuantity(CI->getSExtValue()));
2955  } else {
2956  VBPtrAlign = CGF.getPointerAlign();
2957  }
2958 
2959  llvm::Value *VBTable = Builder.CreateAlignedLoad(VBPtr, VBPtrAlign, "vbtable");
2960 
2961  // Translate from byte offset to table index. It improves analyzability.
2962  llvm::Value *VBTableIndex = Builder.CreateAShr(
2963  VBTableOffset, llvm::ConstantInt::get(VBTableOffset->getType(), 2),
2964  "vbtindex", /*isExact=*/true);
2965 
2966  // Load an i32 offset from the vb-table.
2967  llvm::Value *VBaseOffs = Builder.CreateInBoundsGEP(VBTable, VBTableIndex);
2968  VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0));
2969  return Builder.CreateAlignedLoad(VBaseOffs, CharUnits::fromQuantity(4),
2970  "vbase_offs");
2971 }
2972 
2973 // Returns an adjusted base cast to i8*, since we do more address arithmetic on
2974 // it.
2975 llvm::Value *MicrosoftCXXABI::AdjustVirtualBase(
2976  CodeGenFunction &CGF, const Expr *E, const CXXRecordDecl *RD,
2977  Address Base, llvm::Value *VBTableOffset, llvm::Value *VBPtrOffset) {
2978  CGBuilderTy &Builder = CGF.Builder;
2979  Base = Builder.CreateElementBitCast(Base, CGM.Int8Ty);
2980  llvm::BasicBlock *OriginalBB = nullptr;
2981  llvm::BasicBlock *SkipAdjustBB = nullptr;
2982  llvm::BasicBlock *VBaseAdjustBB = nullptr;
2983 
2984  // In the unspecified inheritance model, there might not be a vbtable at all,
2985  // in which case we need to skip the virtual base lookup. If there is a
2986  // vbtable, the first entry is a no-op entry that gives back the original
2987  // base, so look for a virtual base adjustment offset of zero.
2988  if (VBPtrOffset) {
2989  OriginalBB = Builder.GetInsertBlock();
2990  VBaseAdjustBB = CGF.createBasicBlock("memptr.vadjust");
2991  SkipAdjustBB = CGF.createBasicBlock("memptr.skip_vadjust");
2992  llvm::Value *IsVirtual =
2993  Builder.CreateICmpNE(VBTableOffset, getZeroInt(),
2994  "memptr.is_vbase");
2995  Builder.CreateCondBr(IsVirtual, VBaseAdjustBB, SkipAdjustBB);
2996  CGF.EmitBlock(VBaseAdjustBB);
2997  }
2998 
2999  // If we weren't given a dynamic vbptr offset, RD should be complete and we'll
3000  // know the vbptr offset.
3001  if (!VBPtrOffset) {
3002  CharUnits offs = CharUnits::Zero();
3003  if (!RD->hasDefinition()) {
3004  DiagnosticsEngine &Diags = CGF.CGM.getDiags();
3005  unsigned DiagID = Diags.getCustomDiagID(
3007  "member pointer representation requires a "
3008  "complete class type for %0 to perform this expression");
3009  Diags.Report(E->getExprLoc(), DiagID) << RD << E->getSourceRange();
3010  } else if (RD->getNumVBases())
3011  offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
3012  VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity());
3013  }
3014  llvm::Value *VBPtr = nullptr;
3015  llvm::Value *VBaseOffs =
3016  GetVBaseOffsetFromVBPtr(CGF, Base, VBPtrOffset, VBTableOffset, &VBPtr);
3017  llvm::Value *AdjustedBase = Builder.CreateInBoundsGEP(VBPtr, VBaseOffs);
3018 
3019  // Merge control flow with the case where we didn't have to adjust.
3020  if (VBaseAdjustBB) {
3021  Builder.CreateBr(SkipAdjustBB);
3022  CGF.EmitBlock(SkipAdjustBB);
3023  llvm::PHINode *Phi = Builder.CreatePHI(CGM.Int8PtrTy, 2, "memptr.base");
3024  Phi->addIncoming(Base.getPointer(), OriginalBB);
3025  Phi->addIncoming(AdjustedBase, VBaseAdjustBB);
3026  return Phi;
3027  }
3028  return AdjustedBase;
3029 }
3030 
3031 llvm::Value *MicrosoftCXXABI::EmitMemberDataPointerAddress(
3032  CodeGenFunction &CGF, const Expr *E, Address Base, llvm::Value *MemPtr,
3033  const MemberPointerType *MPT) {
3034  assert(MPT->isMemberDataPointer());
3035  unsigned AS = Base.getAddressSpace();
3036  llvm::Type *PType =
3037  CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
3038  CGBuilderTy &Builder = CGF.Builder;
3039  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
3040  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
3041 
3042  // Extract the fields we need, regardless of model. We'll apply them if we
3043  // have them.
3044  llvm::Value *FieldOffset = MemPtr;
3045  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
3046  llvm::Value *VBPtrOffset = nullptr;
3047  if (MemPtr->getType()->isStructTy()) {
3048  // We need to extract values.
3049  unsigned I = 0;
3050  FieldOffset = Builder.CreateExtractValue(MemPtr, I++);
3051  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
3052  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
3053  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
3054  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
3055  }
3056 
3057  llvm::Value *Addr;
3058  if (VirtualBaseAdjustmentOffset) {
3059  Addr = AdjustVirtualBase(CGF, E, RD, Base, VirtualBaseAdjustmentOffset,
3060  VBPtrOffset);
3061  } else {
3062  Addr = Base.getPointer();
3063  }
3064 
3065  // Cast to char*.
3066  Addr = Builder.CreateBitCast(Addr, CGF.Int8Ty->getPointerTo(AS));
3067 
3068  // Apply the offset, which we assume is non-null.
3069  Addr = Builder.CreateInBoundsGEP(Addr, FieldOffset, "memptr.offset");
3070 
3071  // Cast the address to the appropriate pointer type, adopting the address
3072  // space of the base pointer.
3073  return Builder.CreateBitCast(Addr, PType);
3074 }
3075 
3076 llvm::Value *
3077 MicrosoftCXXABI::EmitMemberPointerConversion(CodeGenFunction &CGF,
3078  const CastExpr *E,
3079  llvm::Value *Src) {
3080  assert(E->getCastKind() == CK_DerivedToBaseMemberPointer ||
3081  E->getCastKind() == CK_BaseToDerivedMemberPointer ||
3082  E->getCastKind() == CK_ReinterpretMemberPointer);
3083 
3084  // Use constant emission if we can.
3085  if (isa<llvm::Constant>(Src))
3086  return EmitMemberPointerConversion(E, cast<llvm::Constant>(Src));
3087 
3088  // We may be adding or dropping fields from the member pointer, so we need
3089  // both types and the inheritance models of both records.
3090  const MemberPointerType *SrcTy =
3092  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3093  bool IsFunc = SrcTy->isMemberFunctionPointer();
3094 
3095  // If the classes use the same null representation, reinterpret_cast is a nop.
3096  bool IsReinterpret = E->getCastKind() == CK_ReinterpretMemberPointer;
3097  if (IsReinterpret && IsFunc)
3098  return Src;
3099 
3100  CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3101  CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3102  if (IsReinterpret &&
3103  SrcRD->nullFieldOffsetIsZero() == DstRD->nullFieldOffsetIsZero())
3104  return Src;
3105 
3106  CGBuilderTy &Builder = CGF.Builder;
3107 
3108  // Branch past the conversion if Src is null.
3109  llvm::Value *IsNotNull = EmitMemberPointerIsNotNull(CGF, Src, SrcTy);
3110  llvm::Constant *DstNull = EmitNullMemberPointer(DstTy);
3111 
3112  // C++ 5.2.10p9: The null member pointer value is converted to the null member
3113  // pointer value of the destination type.
3114  if (IsReinterpret) {
3115  // For reinterpret casts, sema ensures that src and dst are both functions
3116  // or data and have the same size, which means the LLVM types should match.
3117  assert(Src->getType() == DstNull->getType());
3118  return Builder.CreateSelect(IsNotNull, Src, DstNull);
3119  }
3120 
3121  llvm::BasicBlock *OriginalBB = Builder.GetInsertBlock();
3122  llvm::BasicBlock *ConvertBB = CGF.createBasicBlock("memptr.convert");
3123  llvm::BasicBlock *ContinueBB = CGF.createBasicBlock("memptr.converted");
3124  Builder.CreateCondBr(IsNotNull, ConvertBB, ContinueBB);
3125  CGF.EmitBlock(ConvertBB);
3126 
3127  llvm::Value *Dst = EmitNonNullMemberPointerConversion(
3128  SrcTy, DstTy, E->getCastKind(), E->path_begin(), E->path_end(), Src,
3129  Builder);
3130 
3131  Builder.CreateBr(ContinueBB);
3132 
3133  // In the continuation, choose between DstNull and Dst.
3134  CGF.EmitBlock(ContinueBB);
3135  llvm::PHINode *Phi = Builder.CreatePHI(DstNull->getType(), 2, "memptr.converted");
3136  Phi->addIncoming(DstNull, OriginalBB);
3137  Phi->addIncoming(Dst, ConvertBB);
3138  return Phi;
3139 }
3140 
3141 llvm::Value *MicrosoftCXXABI::EmitNonNullMemberPointerConversion(
3142  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3145  CGBuilderTy &Builder) {
3146  const CXXRecordDecl *SrcRD = SrcTy->getMostRecentCXXRecordDecl();
3147  const CXXRecordDecl *DstRD = DstTy->getMostRecentCXXRecordDecl();
3148  MSInheritanceAttr::Spelling SrcInheritance = SrcRD->getMSInheritanceModel();
3149  MSInheritanceAttr::Spelling DstInheritance = DstRD->getMSInheritanceModel();
3150  bool IsFunc = SrcTy->isMemberFunctionPointer();
3151  bool IsConstant = isa<llvm::Constant>(Src);
3152 
3153  // Decompose src.
3154  llvm::Value *FirstField = Src;
3155  llvm::Value *NonVirtualBaseAdjustment = getZeroInt();
3156  llvm::Value *VirtualBaseAdjustmentOffset = getZeroInt();
3157  llvm::Value *VBPtrOffset = getZeroInt();
3158  if (!MSInheritanceAttr::hasOnlyOneField(IsFunc, SrcInheritance)) {
3159  // We need to extract values.
3160  unsigned I = 0;
3161  FirstField = Builder.CreateExtractValue(Src, I++);
3162  if (MSInheritanceAttr::hasNVOffsetField(IsFunc, SrcInheritance))
3163  NonVirtualBaseAdjustment = Builder.CreateExtractValue(Src, I++);
3164  if (MSInheritanceAttr::hasVBPtrOffsetField(SrcInheritance))
3165  VBPtrOffset = Builder.CreateExtractValue(Src, I++);
3166  if (MSInheritanceAttr::hasVBTableOffsetField(SrcInheritance))
3167  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(Src, I++);
3168  }
3169 
3170  bool IsDerivedToBase = (CK == CK_DerivedToBaseMemberPointer);
3171  const MemberPointerType *DerivedTy = IsDerivedToBase ? SrcTy : DstTy;
3172  const CXXRecordDecl *DerivedClass = DerivedTy->getMostRecentCXXRecordDecl();
3173 
3174  // For data pointers, we adjust the field offset directly. For functions, we
3175  // have a separate field.
3176  llvm::Value *&NVAdjustField = IsFunc ? NonVirtualBaseAdjustment : FirstField;
3177 
3178  // The virtual inheritance model has a quirk: the virtual base table is always
3179  // referenced when dereferencing a member pointer even if the member pointer
3180  // is non-virtual. This is accounted for by adjusting the non-virtual offset
3181  // to point backwards to the top of the MDC from the first VBase. Undo this
3182  // adjustment to normalize the member pointer.
3183  llvm::Value *SrcVBIndexEqZero =
3184  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3185  if (SrcInheritance == MSInheritanceAttr::Keyword_virtual_inheritance) {
3186  if (int64_t SrcOffsetToFirstVBase =
3187  getContext().getOffsetOfBaseWithVBPtr(SrcRD).getQuantity()) {
3188  llvm::Value *UndoSrcAdjustment = Builder.CreateSelect(
3189  SrcVBIndexEqZero,
3190  llvm::ConstantInt::get(CGM.IntTy, SrcOffsetToFirstVBase),
3191  getZeroInt());
3192  NVAdjustField = Builder.CreateNSWAdd(NVAdjustField, UndoSrcAdjustment);
3193  }
3194  }
3195 
3196  // A non-zero vbindex implies that we are dealing with a source member in a
3197  // floating virtual base in addition to some non-virtual offset. If the
3198  // vbindex is zero, we are dealing with a source that exists in a non-virtual,
3199  // fixed, base. The difference between these two cases is that the vbindex +
3200  // nvoffset *always* point to the member regardless of what context they are
3201  // evaluated in so long as the vbindex is adjusted. A member inside a fixed
3202  // base requires explicit nv adjustment.
3203  llvm::Constant *BaseClassOffset = llvm::ConstantInt::get(
3204  CGM.IntTy,
3205  CGM.computeNonVirtualBaseClassOffset(DerivedClass, PathBegin, PathEnd)
3206  .getQuantity());
3207 
3208  llvm::Value *NVDisp;
3209  if (IsDerivedToBase)
3210  NVDisp = Builder.CreateNSWSub(NVAdjustField, BaseClassOffset, "adj");
3211  else
3212  NVDisp = Builder.CreateNSWAdd(NVAdjustField, BaseClassOffset, "adj");
3213 
3214  NVAdjustField = Builder.CreateSelect(SrcVBIndexEqZero, NVDisp, getZeroInt());
3215 
3216  // Update the vbindex to an appropriate value in the destination because
3217  // SrcRD's vbtable might not be a strict prefix of the one in DstRD.
3218  llvm::Value *DstVBIndexEqZero = SrcVBIndexEqZero;
3219  if (MSInheritanceAttr::hasVBTableOffsetField(DstInheritance) &&
3220  MSInheritanceAttr::hasVBTableOffsetField(SrcInheritance)) {
3221  if (llvm::GlobalVariable *VDispMap =
3222  getAddrOfVirtualDisplacementMap(SrcRD, DstRD)) {
3223  llvm::Value *VBIndex = Builder.CreateExactUDiv(
3224  VirtualBaseAdjustmentOffset, llvm::ConstantInt::get(CGM.IntTy, 4));
3225  if (IsConstant) {
3226  llvm::Constant *Mapping = VDispMap->getInitializer();
3227  VirtualBaseAdjustmentOffset =
3228  Mapping->getAggregateElement(cast<llvm::Constant>(VBIndex));
3229  } else {
3230  llvm::Value *Idxs[] = {getZeroInt(), VBIndex};
3231  VirtualBaseAdjustmentOffset =
3232  Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(VDispMap, Idxs),
3234  }
3235 
3236  DstVBIndexEqZero =
3237  Builder.CreateICmpEQ(VirtualBaseAdjustmentOffset, getZeroInt());
3238  }
3239  }
3240 
3241  // Set the VBPtrOffset to zero if the vbindex is zero. Otherwise, initialize
3242  // it to the offset of the vbptr.
3243  if (MSInheritanceAttr::hasVBPtrOffsetField(DstInheritance)) {
3244  llvm::Value *DstVBPtrOffset = llvm::ConstantInt::get(
3245  CGM.IntTy,
3246  getContext().getASTRecordLayout(DstRD).getVBPtrOffset().getQuantity());
3247  VBPtrOffset =
3248  Builder.CreateSelect(DstVBIndexEqZero, getZeroInt(), DstVBPtrOffset);
3249  }
3250 
3251  // Likewise, apply a similar adjustment so that dereferencing the member
3252  // pointer correctly accounts for the distance between the start of the first
3253  // virtual base and the top of the MDC.
3254  if (DstInheritance == MSInheritanceAttr::Keyword_virtual_inheritance) {
3255  if (int64_t DstOffsetToFirstVBase =
3256  getContext().getOffsetOfBaseWithVBPtr(DstRD).getQuantity()) {
3257  llvm::Value *DoDstAdjustment = Builder.CreateSelect(
3258  DstVBIndexEqZero,
3259  llvm::ConstantInt::get(CGM.IntTy, DstOffsetToFirstVBase),
3260  getZeroInt());
3261  NVAdjustField = Builder.CreateNSWSub(NVAdjustField, DoDstAdjustment);
3262  }
3263  }
3264 
3265  // Recompose dst from the null struct and the adjusted fields from src.
3266  llvm::Value *Dst;
3267  if (MSInheritanceAttr::hasOnlyOneField(IsFunc, DstInheritance)) {
3268  Dst = FirstField;
3269  } else {
3270  Dst = llvm::UndefValue::get(ConvertMemberPointerType(DstTy));
3271  unsigned Idx = 0;
3272  Dst = Builder.CreateInsertValue(Dst, FirstField, Idx++);
3273  if (MSInheritanceAttr::hasNVOffsetField(IsFunc, DstInheritance))
3274  Dst = Builder.CreateInsertValue(Dst, NonVirtualBaseAdjustment, Idx++);
3275  if (MSInheritanceAttr::hasVBPtrOffsetField(DstInheritance))
3276  Dst = Builder.CreateInsertValue(Dst, VBPtrOffset, Idx++);
3277  if (MSInheritanceAttr::hasVBTableOffsetField(DstInheritance))
3278  Dst = Builder.CreateInsertValue(Dst, VirtualBaseAdjustmentOffset, Idx++);
3279  }
3280  return Dst;
3281 }
3282 
3283 llvm::Constant *
3284 MicrosoftCXXABI::EmitMemberPointerConversion(const CastExpr *E,
3285  llvm::Constant *Src) {
3286  const MemberPointerType *SrcTy =
3288  const MemberPointerType *DstTy = E->getType()->castAs<MemberPointerType>();
3289 
3290  CastKind CK = E->getCastKind();
3291 
3292  return EmitMemberPointerConversion(SrcTy, DstTy, CK, E->path_begin(),
3293  E->path_end(), Src);
3294 }
3295 
3296 llvm::Constant *MicrosoftCXXABI::EmitMemberPointerConversion(
3297  const MemberPointerType *SrcTy, const MemberPointerType *DstTy, CastKind CK,
3299  CastExpr::path_const_iterator PathEnd, llvm::Constant *Src) {
3300  assert(CK == CK_DerivedToBaseMemberPointer ||
3301  CK == CK_BaseToDerivedMemberPointer ||
3302  CK == CK_ReinterpretMemberPointer);
3303  // If src is null, emit a new null for dst. We can't return src because dst
3304  // might have a new representation.
3305  if (MemberPointerConstantIsNull(SrcTy, Src))
3306  return EmitNullMemberPointer(DstTy);
3307 
3308  // We don't need to do anything for reinterpret_casts of non-null member
3309  // pointers. We should only get here when the two type representations have
3310  // the same size.
3311  if (CK == CK_ReinterpretMemberPointer)
3312  return Src;
3313 
3314  CGBuilderTy Builder(CGM, CGM.getLLVMContext());
3315  auto *Dst = cast<llvm::Constant>(EmitNonNullMemberPointerConversion(
3316  SrcTy, DstTy, CK, PathBegin, PathEnd, Src, Builder));
3317 
3318  return Dst;
3319 }
3320 
3321 CGCallee MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(
3322  CodeGenFunction &CGF, const Expr *E, Address This,
3323  llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
3324  const MemberPointerType *MPT) {
3325  assert(MPT->isMemberFunctionPointer());
3326  const FunctionProtoType *FPT =
3328  const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
3329  llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(
3330  CGM.getTypes().arrangeCXXMethodType(RD, FPT, /*FD=*/nullptr));
3331  CGBuilderTy &Builder = CGF.Builder;
3332 
3333  MSInheritanceAttr::Spelling Inheritance = RD->getMSInheritanceModel();
3334 
3335  // Extract the fields we need, regardless of model. We'll apply them if we
3336  // have them.
3337  llvm::Value *FunctionPointer = MemPtr;
3338  llvm::Value *NonVirtualBaseAdjustment = nullptr;
3339  llvm::Value *VirtualBaseAdjustmentOffset = nullptr;
3340  llvm::Value *VBPtrOffset = nullptr;
3341  if (MemPtr->getType()->isStructTy()) {
3342  // We need to extract values.
3343  unsigned I = 0;
3344  FunctionPointer = Builder.CreateExtractValue(MemPtr, I++);
3345  if (MSInheritanceAttr::hasNVOffsetField(MPT, Inheritance))
3346  NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++);
3347  if (MSInheritanceAttr::hasVBPtrOffsetField(Inheritance))
3348  VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
3349  if (MSInheritanceAttr::hasVBTableOffsetField(Inheritance))
3350  VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
3351  }
3352 
3353  if (VirtualBaseAdjustmentOffset) {
3354  ThisPtrForCall = AdjustVirtualBase(CGF, E, RD, This,
3355  VirtualBaseAdjustmentOffset, VBPtrOffset);
3356  } else {
3357  ThisPtrForCall = This.getPointer();
3358  }
3359 
3360  if (NonVirtualBaseAdjustment) {
3361  // Apply the adjustment and cast back to the original struct type.
3362  llvm::Value *Ptr = Builder.CreateBitCast(ThisPtrForCall, CGF.Int8PtrTy);
3363  Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment);
3364  ThisPtrForCall = Builder.CreateBitCast(Ptr, ThisPtrForCall->getType(),
3365  "this.adjusted");
3366  }
3367 
3368  FunctionPointer =
3369  Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo());
3370  CGCallee Callee(FPT, FunctionPointer);
3371  return Callee;
3372 }
3373 
3375  return new MicrosoftCXXABI(CGM);
3376 }
3377 
3378 // MS RTTI Overview:
3379 // The run time type information emitted by cl.exe contains 5 distinct types of
3380 // structures. Many of them reference each other.
3381 //
3382 // TypeInfo: Static classes that are returned by typeid.
3383 //
3384 // CompleteObjectLocator: Referenced by vftables. They contain information
3385 // required for dynamic casting, including OffsetFromTop. They also contain
3386 // a reference to the TypeInfo for the type and a reference to the
3387 // CompleteHierarchyDescriptor for the type.
3388 //
3389 // ClassHierarchyDescriptor: Contains information about a class hierarchy.
3390 // Used during dynamic_cast to walk a class hierarchy. References a base
3391 // class array and the size of said array.
3392 //
3393 // BaseClassArray: Contains a list of classes in a hierarchy. BaseClassArray is
3394 // somewhat of a misnomer because the most derived class is also in the list
3395 // as well as multiple copies of virtual bases (if they occur multiple times
3396 // in the hierarchy.) The BaseClassArray contains one BaseClassDescriptor for
3397 // every path in the hierarchy, in pre-order depth first order. Note, we do
3398 // not declare a specific llvm type for BaseClassArray, it's merely an array
3399 // of BaseClassDescriptor pointers.
3400 //
3401 // BaseClassDescriptor: Contains information about a class in a class hierarchy.
3402 // BaseClassDescriptor is also somewhat of a misnomer for the same reason that
3403 // BaseClassArray is. It contains information about a class within a
3404 // hierarchy such as: is this base is ambiguous and what is its offset in the
3405 // vbtable. The names of the BaseClassDescriptors have all of their fields
3406 // mangled into them so they can be aggressively deduplicated by the linker.
3407 
3408 static llvm::GlobalVariable *getTypeInfoVTable(CodeGenModule &CGM) {
3409  StringRef MangledName("??_7type_info@@6B@");
3410  if (auto VTable = CGM.getModule().getNamedGlobal(MangledName))
3411  return VTable;
3412  return new llvm::GlobalVariable(CGM.getModule(), CGM.Int8PtrTy,
3413  /*isConstant=*/true,
3415  /*Initializer=*/nullptr, MangledName);
3416 }
3417 
3418 namespace {
3419 
3420 /// A Helper struct that stores information about a class in a class
3421 /// hierarchy. The information stored in these structs struct is used during
3422 /// the generation of ClassHierarchyDescriptors and BaseClassDescriptors.
3423 // During RTTI creation, MSRTTIClasses are stored in a contiguous array with
3424 // implicit depth first pre-order tree connectivity. getFirstChild and
3425 // getNextSibling allow us to walk the tree efficiently.
3426 struct MSRTTIClass {
3427  enum {
3428  IsPrivateOnPath = 1 | 8,
3429  IsAmbiguous = 2,
3430  IsPrivate = 4,
3431  IsVirtual = 16,
3432  HasHierarchyDescriptor = 64
3433  };
3434  MSRTTIClass(const CXXRecordDecl *RD) : RD(RD) {}
3435  uint32_t initialize(const MSRTTIClass *Parent,
3436  const CXXBaseSpecifier *Specifier);
3437 
3438  MSRTTIClass *getFirstChild() { return this + 1; }
3439  static MSRTTIClass *getNextChild(MSRTTIClass *Child) {
3440  return Child + 1 + Child->NumBases;
3441  }
3442 
3443  const CXXRecordDecl *RD, *VirtualRoot;
3444  uint32_t Flags, NumBases, OffsetInVBase;
3445 };
3446 
3447 /// Recursively initialize the base class array.
3448 uint32_t MSRTTIClass::initialize(const MSRTTIClass *Parent,
3449  const CXXBaseSpecifier *Specifier) {
3450  Flags = HasHierarchyDescriptor;
3451  if (!Parent) {
3452  VirtualRoot = nullptr;
3453  OffsetInVBase = 0;
3454  } else {
3455  if (Specifier->getAccessSpecifier() != AS_public)
3456  Flags |= IsPrivate | IsPrivateOnPath;
3457  if (Specifier->isVirtual()) {
3458  Flags |= IsVirtual;
3459  VirtualRoot = RD;
3460  OffsetInVBase = 0;
3461  } else {
3462  if (Parent->Flags & IsPrivateOnPath)
3463  Flags |= IsPrivateOnPath;
3464  VirtualRoot = Parent->VirtualRoot;
3465  OffsetInVBase = Parent->OffsetInVBase + RD->getASTContext()
3467  }
3468  }
3469  NumBases = 0;
3470  MSRTTIClass *Child = getFirstChild();
3471  for (const CXXBaseSpecifier &Base : RD->bases()) {
3472  NumBases += Child->initialize(this, &Base) + 1;
3473  Child = getNextChild(Child);
3474  }
3475  return NumBases;
3476 }
3477 
3478 static llvm::GlobalValue::LinkageTypes getLinkageForRTTI(QualType Ty) {
3479  switch (Ty->getLinkage()) {
3480  case NoLinkage:
3481  case InternalLinkage:
3482  case UniqueExternalLinkage:
3484 
3485  case VisibleNoLinkage:
3486  case ModuleInternalLinkage:
3487  case ModuleLinkage:
3488  case ExternalLinkage:
3489  return llvm::GlobalValue::LinkOnceODRLinkage;
3490  }
3491  llvm_unreachable("Invalid linkage!");
3492 }
3493 
3494 /// An ephemeral helper class for building MS RTTI types. It caches some
3495 /// calls to the module and information about the most derived class in a
3496 /// hierarchy.
3497 struct MSRTTIBuilder {
3498  enum {
3499  HasBranchingHierarchy = 1,
3500  HasVirtualBranchingHierarchy = 2,
3501  HasAmbiguousBases = 4
3502  };
3503 
3504  MSRTTIBuilder(MicrosoftCXXABI &ABI, const CXXRecordDecl *RD)
3505  : CGM(ABI.CGM), Context(CGM.getContext()),
3506  VMContext(CGM.getLLVMContext()), Module(CGM.getModule()), RD(RD),
3507  Linkage(getLinkageForRTTI(CGM.getContext().getTagDeclType(RD))),
3508  ABI(ABI) {}
3509 
3510  llvm::GlobalVariable *getBaseClassDescriptor(const MSRTTIClass &Classes);
3511  llvm::GlobalVariable *
3512  getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes);
3513  llvm::GlobalVariable *getClassHierarchyDescriptor();
3514  llvm::GlobalVariable *getCompleteObjectLocator(const VPtrInfo &Info);
3515 
3516  CodeGenModule &CGM;
3517  ASTContext &Context;
3518  llvm::LLVMContext &VMContext;
3519  llvm::Module &Module;
3520  const CXXRecordDecl *RD;
3521  llvm::GlobalVariable::LinkageTypes Linkage;
3522  MicrosoftCXXABI &ABI;
3523 };
3524 
3525 } // namespace
3526 
3527 /// Recursively serializes a class hierarchy in pre-order depth first
3528 /// order.
3530  const CXXRecordDecl *RD) {
3531  Classes.push_back(MSRTTIClass(RD));
3532  for (const CXXBaseSpecifier &Base : RD->bases())
3533  serializeClassHierarchy(Classes, Base.getType()->getAsCXXRecordDecl());
3534 }
3535 
3536 /// Find ambiguity among base classes.
3537 static void
3539  llvm::SmallPtrSet<const CXXRecordDecl *, 8> VirtualBases;
3540  llvm::SmallPtrSet<const CXXRecordDecl *, 8> UniqueBases;
3541  llvm::SmallPtrSet<const CXXRecordDecl *, 8> AmbiguousBases;
3542  for (MSRTTIClass *Class = &Classes.front(); Class <= &Classes.back();) {
3543  if ((Class->Flags & MSRTTIClass::IsVirtual) &&
3544  !VirtualBases.insert(Class->RD).second) {
3545  Class = MSRTTIClass::getNextChild(Class);
3546  continue;
3547  }
3548  if (!UniqueBases.insert(Class->RD).second)
3549  AmbiguousBases.insert(Class->RD);
3550  Class++;
3551  }
3552  if (AmbiguousBases.empty())
3553  return;
3554  for (MSRTTIClass &Class : Classes)
3555  if (AmbiguousBases.count(Class.RD))
3556  Class.Flags |= MSRTTIClass::IsAmbiguous;
3557 }
3558 
3559 llvm::GlobalVariable *MSRTTIBuilder::getClassHierarchyDescriptor() {
3560  SmallString<256> MangledName;
3561  {
3562  llvm::raw_svector_ostream Out(MangledName);
3563  ABI.getMangleContext().mangleCXXRTTIClassHierarchyDescriptor(RD, Out);
3564  }
3565 
3566  // Check to see if we've already declared this ClassHierarchyDescriptor.
3567  if (auto CHD = Module.getNamedGlobal(MangledName))
3568  return CHD;
3569 
3570  // Serialize the class hierarchy and initialize the CHD Fields.
3572  serializeClassHierarchy(Classes, RD);
3573  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
3574  detectAmbiguousBases(Classes);
3575  int Flags = 0;
3576  for (auto Class : Classes) {
3577  if (Class.RD->getNumBases() > 1)
3578  Flags |= HasBranchingHierarchy;
3579  // Note: cl.exe does not calculate "HasAmbiguousBases" correctly. We
3580  // believe the field isn't actually used.
3581  if (Class.Flags & MSRTTIClass::IsAmbiguous)
3582  Flags |= HasAmbiguousBases;
3583  }
3584  if ((Flags & HasBranchingHierarchy) && RD->getNumVBases() != 0)
3585  Flags |= HasVirtualBranchingHierarchy;
3586  // These gep indices are used to get the address of the first element of the
3587  // base class array.
3588  llvm::Value *GEPIndices[] = {llvm::ConstantInt::get(CGM.IntTy, 0),
3589  llvm::ConstantInt::get(CGM.IntTy, 0)};
3590 
3591  // Forward-declare the class hierarchy descriptor
3592  auto Type = ABI.getClassHierarchyDescriptorType();
3593  auto CHD = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3594  /*Initializer=*/nullptr,
3595  MangledName);
3596  if (CHD->isWeakForLinker())
3597  CHD->setComdat(CGM.getModule().getOrInsertComdat(CHD->getName()));
3598 
3599  auto *Bases = getBaseClassArray(Classes);
3600 
3601  // Initialize the base class ClassHierarchyDescriptor.
3602  llvm::Constant *Fields[] = {
3603  llvm::ConstantInt::get(CGM.IntTy, 0), // reserved by the runtime
3604  llvm::ConstantInt::get(CGM.IntTy, Flags),
3605  llvm::ConstantInt::get(CGM.IntTy, Classes.size()),
3606  ABI.getImageRelativeConstant(llvm::ConstantExpr::getInBoundsGetElementPtr(
3607  Bases->getValueType(), Bases,
3608  llvm::ArrayRef<llvm::Value *>(GEPIndices))),
3609  };
3610  CHD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3611  return CHD;
3612 }
3613 
3614 llvm::GlobalVariable *
3615 MSRTTIBuilder::getBaseClassArray(SmallVectorImpl<MSRTTIClass> &Classes) {
3616  SmallString<256> MangledName;
3617  {
3618  llvm::raw_svector_ostream Out(MangledName);
3619  ABI.getMangleContext().mangleCXXRTTIBaseClassArray(RD, Out);
3620  }
3621 
3622  // Forward-declare the base class array.
3623  // cl.exe pads the base class array with 1 (in 32 bit mode) or 4 (in 64 bit
3624  // mode) bytes of padding. We provide a pointer sized amount of padding by
3625  // adding +1 to Classes.size(). The sections have pointer alignment and are
3626  // marked pick-any so it shouldn't matter.
3627  llvm::Type *PtrType = ABI.getImageRelativeType(
3628  ABI.getBaseClassDescriptorType()->getPointerTo());
3629  auto *ArrType = llvm::ArrayType::get(PtrType, Classes.size() + 1);
3630  auto *BCA =
3631  new llvm::GlobalVariable(Module, ArrType,
3632  /*isConstant=*/true, Linkage,
3633  /*Initializer=*/nullptr, MangledName);
3634  if (BCA->isWeakForLinker())
3635  BCA->setComdat(CGM.getModule().getOrInsertComdat(BCA->getName()));
3636 
3637  // Initialize the BaseClassArray.
3638  SmallVector<llvm::Constant *, 8> BaseClassArrayData;
3639  for (MSRTTIClass &Class : Classes)
3640  BaseClassArrayData.push_back(
3641  ABI.getImageRelativeConstant(getBaseClassDescriptor(Class)));
3642  BaseClassArrayData.push_back(llvm::Constant::getNullValue(PtrType));
3643  BCA->setInitializer(llvm::ConstantArray::get(ArrType, BaseClassArrayData));
3644  return BCA;
3645 }
3646 
3647 llvm::GlobalVariable *
3648 MSRTTIBuilder::getBaseClassDescriptor(const MSRTTIClass &Class) {
3649  // Compute the fields for the BaseClassDescriptor. They are computed up front
3650  // because they are mangled into the name of the object.
3651  uint32_t OffsetInVBTable = 0;
3652  int32_t VBPtrOffset = -1;
3653  if (Class.VirtualRoot) {
3654  auto &VTableContext = CGM.getMicrosoftVTableContext();
3655  OffsetInVBTable = VTableContext.getVBTableIndex(RD, Class.VirtualRoot) * 4;
3656  VBPtrOffset = Context.getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
3657  }
3658 
3659  SmallString<256> MangledName;
3660  {
3661  llvm::raw_svector_ostream Out(MangledName);
3662  ABI.getMangleContext().mangleCXXRTTIBaseClassDescriptor(
3663  Class.RD, Class.OffsetInVBase, VBPtrOffset, OffsetInVBTable,
3664  Class.Flags, Out);
3665  }
3666 
3667  // Check to see if we've already declared this object.
3668  if (auto BCD = Module.getNamedGlobal(MangledName))
3669  return BCD;
3670 
3671  // Forward-declare the base class descriptor.
3672  auto Type = ABI.getBaseClassDescriptorType();
3673  auto BCD =
3674  new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3675  /*Initializer=*/nullptr, MangledName);
3676  if (BCD->isWeakForLinker())
3677  BCD->setComdat(CGM.getModule().getOrInsertComdat(BCD->getName()));
3678 
3679  // Initialize the BaseClassDescriptor.
3680  llvm::Constant *Fields[] = {
3681  ABI.getImageRelativeConstant(
3682  ABI.getAddrOfRTTIDescriptor(Context.getTypeDeclType(Class.RD))),
3683  llvm::ConstantInt::get(CGM.IntTy, Class.NumBases),
3684  llvm::ConstantInt::get(CGM.IntTy, Class.OffsetInVBase),
3685  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset),
3686  llvm::ConstantInt::get(CGM.IntTy, OffsetInVBTable),
3687  llvm::ConstantInt::get(CGM.IntTy, Class.Flags),
3688  ABI.getImageRelativeConstant(
3689  MSRTTIBuilder(ABI, Class.RD).getClassHierarchyDescriptor()),
3690  };
3691  BCD->setInitializer(llvm::ConstantStruct::get(Type, Fields));
3692  return BCD;
3693 }
3694 
3695 llvm::GlobalVariable *
3696 MSRTTIBuilder::getCompleteObjectLocator(const VPtrInfo &Info) {
3697  SmallString<256> MangledName;
3698  {
3699  llvm::raw_svector_ostream Out(MangledName);
3700  ABI.getMangleContext().mangleCXXRTTICompleteObjectLocator(RD, Info.MangledPath, Out);
3701  }
3702 
3703  // Check to see if we've already computed this complete object locator.
3704  if (auto COL = Module.getNamedGlobal(MangledName))
3705  return COL;
3706 
3707  // Compute the fields of the complete object locator.
3708  int OffsetToTop = Info.FullOffsetInMDC.getQuantity();
3709  int VFPtrOffset = 0;
3710  // The offset includes the vtordisp if one exists.
3711  if (const CXXRecordDecl *VBase = Info.getVBaseWithVPtr())
3712  if (Context.getASTRecordLayout(RD)
3714  .find(VBase)
3715  ->second.hasVtorDisp())
3716  VFPtrOffset = Info.NonVirtualOffset.getQuantity() + 4;
3717 
3718  // Forward-declare the complete object locator.
3719  llvm::StructType *Type = ABI.getCompleteObjectLocatorType();
3720  auto COL = new llvm::GlobalVariable(Module, Type, /*isConstant=*/true, Linkage,
3721  /*Initializer=*/nullptr, MangledName);
3722 
3723  // Initialize the CompleteObjectLocator.
3724  llvm::Constant *Fields[] = {
3725  llvm::ConstantInt::get(CGM.IntTy, ABI.isImageRelative()),
3726  llvm::ConstantInt::get(CGM.IntTy, OffsetToTop),
3727  llvm::ConstantInt::get(CGM.IntTy, VFPtrOffset),
3728  ABI.getImageRelativeConstant(
3729  CGM.GetAddrOfRTTIDescriptor(Context.getTypeDeclType(RD))),
3730  ABI.getImageRelativeConstant(getClassHierarchyDescriptor()),
3731  ABI.getImageRelativeConstant(COL),
3732  };
3733  llvm::ArrayRef<llvm::Constant *> FieldsRef(Fields);
3734  if (!ABI.isImageRelative())
3735  FieldsRef = FieldsRef.drop_back();
3736  COL->setInitializer(llvm::ConstantStruct::get(Type, FieldsRef));
3737  if (COL->isWeakForLinker())
3738  COL->setComdat(CGM.getModule().getOrInsertComdat(COL->getName()));
3739  return COL;
3740 }
3741 
3743  bool &IsConst, bool &IsVolatile,
3744  bool &IsUnaligned) {
3745  T = Context.getExceptionObjectType(T);
3746 
3747  // C++14 [except.handle]p3:
3748  // A handler is a match for an exception object of type E if [...]
3749  // - the handler is of type cv T or const T& where T is a pointer type and
3750  // E is a pointer type that can be converted to T by [...]
3751  // - a qualification conversion
3752  IsConst = false;
3753  IsVolatile = false;
3754  IsUnaligned = false;
3755  QualType PointeeType = T->getPointeeType();
3756  if (!PointeeType.isNull()) {
3757  IsConst = PointeeType.isConstQualified();
3758  IsVolatile = PointeeType.isVolatileQualified();
3759  IsUnaligned = PointeeType.getQualifiers().hasUnaligned();
3760  }
3761 
3762  // Member pointer types like "const int A::*" are represented by having RTTI
3763  // for "int A::*" and separately storing the const qualifier.
3764  if (const auto *MPTy = T->getAs<MemberPointerType>())
3765  T = Context.getMemberPointerType(PointeeType.getUnqualifiedType(),
3766  MPTy->getClass());
3767 
3768  // Pointer types like "const int * const *" are represented by having RTTI
3769  // for "const int **" and separately storing the const qualifier.
3770  if (T->isPointerType())
3771  T = Context.getPointerType(PointeeType.getUnqualifiedType());
3772 
3773  return T;
3774 }
3775 
3777 MicrosoftCXXABI::getAddrOfCXXCatchHandlerType(QualType Type,
3778  QualType CatchHandlerType) {
3779  // TypeDescriptors for exceptions never have qualified pointer types,
3780  // qualifiers are stored separately in order to support qualification
3781  // conversions.
3782  bool IsConst, IsVolatile, IsUnaligned;
3783  Type =
3784  decomposeTypeForEH(getContext(), Type, IsConst, IsVolatile, IsUnaligned);
3785 
3786  bool IsReference = CatchHandlerType->isReferenceType();
3787 
3788  uint32_t Flags = 0;
3789  if (IsConst)
3790  Flags |= 1;
3791  if (IsVolatile)
3792  Flags |= 2;
3793  if (IsUnaligned)
3794  Flags |= 4;
3795  if (IsReference)
3796  Flags |= 8;
3797 
3798  return CatchTypeInfo{getAddrOfRTTIDescriptor(Type)->stripPointerCasts(),
3799  Flags};
3800 }
3801 
3802 /// Gets a TypeDescriptor. Returns a llvm::Constant * rather than a
3803 /// llvm::GlobalVariable * because different type descriptors have different
3804 /// types, and need to be abstracted. They are abstracting by casting the
3805 /// address to an Int8PtrTy.
3806 llvm::Constant *MicrosoftCXXABI::getAddrOfRTTIDescriptor(QualType Type) {
3807  SmallString<256> MangledName;
3808  {
3809  llvm::raw_svector_ostream Out(MangledName);
3810  getMangleContext().mangleCXXRTTI(Type, Out);
3811  }
3812 
3813  // Check to see if we've already declared this TypeDescriptor.
3814  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
3815  return llvm::ConstantExpr::getBitCast(GV, CGM.Int8PtrTy);
3816 
3817  // Note for the future: If we would ever like to do deferred emission of
3818  // RTTI, check if emitting vtables opportunistically need any adjustment.
3819 
3820  // Compute the fields for the TypeDescriptor.
3821  SmallString<256> TypeInfoString;
3822  {
3823  llvm::raw_svector_ostream Out(TypeInfoString);
3824  getMangleContext().mangleCXXRTTIName(Type, Out);
3825  }
3826 
3827  // Declare and initialize the TypeDescriptor.
3828  llvm::Constant *Fields[] = {
3829  getTypeInfoVTable(CGM), // VFPtr
3830  llvm::ConstantPointerNull::get(CGM.Int8PtrTy), // Runtime data
3831  llvm::ConstantDataArray::getString(CGM.getLLVMContext(), TypeInfoString)};
3832  llvm::StructType *TypeDescriptorType =
3833  getTypeDescriptorType(TypeInfoString);
3834  auto *Var = new llvm::GlobalVariable(
3835  CGM.getModule(), TypeDescriptorType, /*isConstant=*/false,
3836  getLinkageForRTTI(Type),
3837  llvm::ConstantStruct::get(TypeDescriptorType, Fields),
3838  MangledName);
3839  if (Var->isWeakForLinker())
3840  Var->setComdat(CGM.getModule().getOrInsertComdat(Var->getName()));
3841  return llvm::ConstantExpr::getBitCast(Var, CGM.Int8PtrTy);
3842 }
3843 
3844 /// Gets or a creates a Microsoft CompleteObjectLocator.
3845 llvm::GlobalVariable *
3846 MicrosoftCXXABI::getMSCompleteObjectLocator(const CXXRecordDecl *RD,
3847  const VPtrInfo &Info) {
3848  return MSRTTIBuilder(*this, RD).getCompleteObjectLocator(Info);
3849 }
3850 
3851 void MicrosoftCXXABI::emitCXXStructor(GlobalDecl GD) {
3852  if (auto *ctor = dyn_cast<CXXConstructorDecl>(GD.getDecl())) {
3853  // There are no constructor variants, always emit the complete destructor.
3854  llvm::Function *Fn =
3856  CGM.maybeSetTrivialComdat(*ctor, *Fn);
3857  return;
3858  }
3859 
3860  auto *dtor = cast<CXXDestructorDecl>(GD.getDecl());
3861 
3862  // Emit the base destructor if the base and complete (vbase) destructors are
3863  // equivalent. This effectively implements -mconstructor-aliases as part of
3864  // the ABI.
3865  if (GD.getDtorType() == Dtor_Complete &&
3866  dtor->getParent()->getNumVBases() == 0)
3867  GD = GD.getWithDtorType(Dtor_Base);
3868 
3869  // The base destructor is equivalent to the base destructor of its
3870  // base class if there is exactly one non-virtual base class with a
3871  // non-trivial destructor, there are no fields with a non-trivial
3872  // destructor, and the body of the destructor is trivial.
3873  if (GD.getDtorType() == Dtor_Base && !CGM.TryEmitBaseDestructorAsAlias(dtor))
3874  return;
3875 
3876  llvm::Function *Fn = CGM.codegenCXXStructor(GD);
3877  if (Fn->isWeakForLinker())
3878  Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName()));
3879 }
3880 
3881 llvm::Function *
3882 MicrosoftCXXABI::getAddrOfCXXCtorClosure(const CXXConstructorDecl *CD,
3883  CXXCtorType CT) {
3884  assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure);
3885 
3886  // Calculate the mangled name.
3887  SmallString<256> ThunkName;
3888  llvm::raw_svector_ostream Out(ThunkName);
3889  getMangleContext().mangleCXXCtor(CD, CT, Out);
3890 
3891  // If the thunk has been generated previously, just return it.
3892  if (llvm::GlobalValue *GV = CGM.getModule().getNamedValue(ThunkName))
3893  return cast<llvm::Function>(GV);
3894 
3895  // Create the llvm::Function.
3896  const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeMSCtorClosure(CD, CT);
3897  llvm::FunctionType *ThunkTy = CGM.getTypes().GetFunctionType(FnInfo);
3898  const CXXRecordDecl *RD = CD->getParent();
3899  QualType RecordTy = getContext().getRecordType(RD);
3900  llvm::Function *ThunkFn = llvm::Function::Create(
3901  ThunkTy, getLinkageForRTTI(RecordTy), ThunkName.str(), &CGM.getModule());
3902  ThunkFn->setCallingConv(static_cast<llvm::CallingConv::ID>(
3903  FnInfo.getEffectiveCallingConvention()));
3904  if (ThunkFn->isWeakForLinker())
3905  ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName()));
3906  bool IsCopy = CT == Ctor_CopyingClosure;
3907 
3908  // Start codegen.
3909  CodeGenFunction CGF(CGM);
3910  CGF.CurGD = GlobalDecl(CD, Ctor_Complete);
3911 
3912  // Build FunctionArgs.
3913  FunctionArgList FunctionArgs;
3914 
3915  // A constructor always starts with a 'this' pointer as its first argument.
3916  buildThisParam(CGF, FunctionArgs);
3917 
3918  // Following the 'this' pointer is a reference to the source object that we
3919  // are copying from.
3920  ImplicitParamDecl SrcParam(
3921  getContext(), /*DC=*/nullptr, SourceLocation(),
3922  &getContext().Idents.get("src"),
3923  getContext().getLValueReferenceType(RecordTy,
3924  /*SpelledAsLValue=*/true),
3926  if (IsCopy)
3927  FunctionArgs.push_back(&SrcParam);
3928 
3929  // Constructors for classes which utilize virtual bases have an additional
3930  // parameter which indicates whether or not it is being delegated to by a more
3931  // derived constructor.
3932  ImplicitParamDecl IsMostDerived(getContext(), /*DC=*/nullptr,
3933  SourceLocation(),
3934  &getContext().Idents.get("is_most_derived"),
3935  getContext().IntTy, ImplicitParamDecl::Other);
3936  // Only add the parameter to the list if the class has virtual bases.
3937  if (RD->getNumVBases() > 0)
3938  FunctionArgs.push_back(&IsMostDerived);
3939 
3940  // Start defining the function.
3941  auto NL = ApplyDebugLocation::CreateEmpty(CGF);
3942  CGF.StartFunction(GlobalDecl(), FnInfo.getReturnType(), ThunkFn, FnInfo,
3943  FunctionArgs, CD->getLocation(), SourceLocation());
3944  // Create a scope with an artificial location for the body of this function.
3945  auto AL = ApplyDebugLocation::CreateArtificial(CGF);
3946  setCXXABIThisValue(CGF, loadIncomingCXXThis(CGF));
3947  llvm::Value *This = getThisValue(CGF);
3948 
3949  llvm::Value *SrcVal =
3950  IsCopy ? CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(&SrcParam), "src")
3951  : nullptr;
3952 
3953  CallArgList Args;
3954 
3955  // Push the this ptr.
3956  Args.add(RValue::get(This), CD->getThisType());
3957 
3958  // Push the src ptr.
3959  if (SrcVal)
3960  Args.add(RValue::get(SrcVal), SrcParam.getType());
3961 
3962  // Add the rest of the default arguments.
3964  ArrayRef<ParmVarDecl *> params = CD->parameters().drop_front(IsCopy ? 1 : 0);
3965  for (const ParmVarDecl *PD : params) {
3966  assert(PD->hasDefaultArg() && "ctor closure lacks default args");
3967  ArgVec.push_back(PD->getDefaultArg());
3968  }
3969 
3970  CodeGenFunction::RunCleanupsScope Cleanups(CGF);
3971 
3972  const auto *FPT = CD->getType()->castAs<FunctionProtoType>();
3973  CGF.EmitCallArgs(Args, FPT, llvm::makeArrayRef(ArgVec), CD, IsCopy ? 1 : 0);
3974 
3975  // Insert any ABI-specific implicit constructor arguments.
3976  AddedStructorArgs ExtraArgs =
3977  addImplicitConstructorArgs(CGF, CD, Ctor_Complete,
3978  /*ForVirtualBase=*/false,
3979  /*Delegating=*/false, Args);
3980  // Call the destructor with our arguments.
3981  llvm::Constant *CalleePtr =
3983  CGCallee Callee =
3984  CGCallee::forDirect(CalleePtr, GlobalDecl(CD, Ctor_Complete));
3985  const CGFunctionInfo &CalleeInfo = CGM.getTypes().arrangeCXXConstructorCall(
3986  Args, CD, Ctor_Complete, ExtraArgs.Prefix, ExtraArgs.Suffix);
3987  CGF.EmitCall(CalleeInfo, Callee, ReturnValueSlot(), Args);
3988 
3989  Cleanups.ForceCleanup();
3990 
3991  // Emit the ret instruction, remove any temporary instructions created for the
3992  // aid of CodeGen.
3994 
3995  return ThunkFn;
3996 }
3997 
3998 llvm::Constant *MicrosoftCXXABI::getCatchableType(QualType T,
3999  uint32_t NVOffset,
4000  int32_t VBPtrOffset,
4001  uint32_t VBIndex) {
4002  assert(!T->isReferenceType());
4003 
4004  CXXRecordDecl *RD = T->getAsCXXRecordDecl();
4005  const CXXConstructorDecl *CD =
4006  RD ? CGM.getContext().getCopyConstructorForExceptionObject(RD) : nullptr;
4008  if (CD)
4009  if (!hasDefaultCXXMethodCC(getContext(), CD) || CD->getNumParams() != 1)
4010  CT = Ctor_CopyingClosure;
4011 
4012  uint32_t Size = getContext().getTypeSizeInChars(T).getQuantity();
4013  SmallString<256> MangledName;
4014  {
4015  llvm::raw_svector_ostream Out(MangledName);
4016  getMangleContext().mangleCXXCatchableType(T, CD, CT, Size, NVOffset,
4017  VBPtrOffset, VBIndex, Out);
4018  }
4019  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
4020  return getImageRelativeConstant(GV);
4021 
4022  // The TypeDescriptor is used by the runtime to determine if a catch handler
4023  // is appropriate for the exception object.
4024  llvm::Constant *TD = getImageRelativeConstant(getAddrOfRTTIDescriptor(T));
4025 
4026  // The runtime is responsible for calling the copy constructor if the
4027  // exception is caught by value.
4028  llvm::Constant *CopyCtor;
4029  if (CD) {
4030  if (CT == Ctor_CopyingClosure)
4031  CopyCtor = getAddrOfCXXCtorClosure(CD, Ctor_CopyingClosure);
4032  else
4033  CopyCtor = CGM.getAddrOfCXXStructor(GlobalDecl(CD, Ctor_Complete));
4034 
4035  CopyCtor = llvm::ConstantExpr::getBitCast(CopyCtor, CGM.Int8PtrTy);
4036  } else {
4037  CopyCtor = llvm::Constant::getNullValue(CGM.Int8PtrTy);
4038  }
4039  CopyCtor = getImageRelativeConstant(CopyCtor);
4040 
4041  bool IsScalar = !RD;
4042  bool HasVirtualBases = false;
4043  bool IsStdBadAlloc = false; // std::bad_alloc is special for some reason.
4044  QualType PointeeType = T;
4045  if (T->isPointerType())
4046  PointeeType = T->getPointeeType();
4047  if (const CXXRecordDecl *RD = PointeeType->getAsCXXRecordDecl()) {
4048  HasVirtualBases = RD->getNumVBases() > 0;
4049  if (IdentifierInfo *II = RD->getIdentifier())
4050  IsStdBadAlloc = II->isStr("bad_alloc") && RD->isInStdNamespace();
4051  }
4052 
4053  // Encode the relevant CatchableType properties into the Flags bitfield.
4054  // FIXME: Figure out how bits 2 or 8 can get set.
4055  uint32_t Flags = 0;
4056  if (IsScalar)
4057  Flags |= 1;
4058  if (HasVirtualBases)
4059  Flags |= 4;
4060  if (IsStdBadAlloc)
4061  Flags |= 16;
4062 
4063  llvm::Constant *Fields[] = {
4064  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4065  TD, // TypeDescriptor
4066  llvm::ConstantInt::get(CGM.IntTy, NVOffset), // NonVirtualAdjustment
4067  llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset), // OffsetToVBPtr
4068  llvm::ConstantInt::get(CGM.IntTy, VBIndex), // VBTableIndex
4069  llvm::ConstantInt::get(CGM.IntTy, Size), // Size
4070  CopyCtor // CopyCtor
4071  };
4072  llvm::StructType *CTType = getCatchableTypeType();
4073  auto *GV = new llvm::GlobalVariable(
4074  CGM.getModule(), CTType, /*isConstant=*/true, getLinkageForRTTI(T),
4075  llvm::ConstantStruct::get(CTType, Fields), MangledName);
4076  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4077  GV->setSection(".xdata");
4078  if (GV->isWeakForLinker())
4079  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4080  return getImageRelativeConstant(GV);
4081 }
4082 
4083 llvm::GlobalVariable *MicrosoftCXXABI::getCatchableTypeArray(QualType T) {
4084  assert(!T->isReferenceType());
4085 
4086  // See if we've already generated a CatchableTypeArray for this type before.
4087  llvm::GlobalVariable *&CTA = CatchableTypeArrays[T];
4088  if (CTA)
4089  return CTA;
4090 
4091  // Ensure that we don't have duplicate entries in our CatchableTypeArray by
4092  // using a SmallSetVector. Duplicates may arise due to virtual bases
4093  // occurring more than once in the hierarchy.
4095 
4096  // C++14 [except.handle]p3:
4097  // A handler is a match for an exception object of type E if [...]
4098  // - the handler is of type cv T or cv T& and T is an unambiguous public
4099  // base class of E, or
4100  // - the handler is of type cv T or const T& where T is a pointer type and
4101  // E is a pointer type that can be converted to T by [...]
4102  // - a standard pointer conversion (4.10) not involving conversions to
4103  // pointers to private or protected or ambiguous classes
4104  const CXXRecordDecl *MostDerivedClass = nullptr;
4105  bool IsPointer = T->isPointerType();
4106  if (IsPointer)
4107  MostDerivedClass = T->getPointeeType()->getAsCXXRecordDecl();
4108  else
4109  MostDerivedClass = T->getAsCXXRecordDecl();
4110 
4111  // Collect all the unambiguous public bases of the MostDerivedClass.
4112  if (MostDerivedClass) {
4113  const ASTContext &Context = getContext();
4114  const ASTRecordLayout &MostDerivedLayout =
4115  Context.getASTRecordLayout(MostDerivedClass);
4116  MicrosoftVTableContext &VTableContext = CGM.getMicrosoftVTableContext();
4118  serializeClassHierarchy(Classes, MostDerivedClass);
4119  Classes.front().initialize(/*Parent=*/nullptr, /*Specifier=*/nullptr);
4120  detectAmbiguousBases(Classes);
4121  for (const MSRTTIClass &Class : Classes) {
4122  // Skip any ambiguous or private bases.
4123  if (Class.Flags &
4124  (MSRTTIClass::IsPrivateOnPath | MSRTTIClass::IsAmbiguous))
4125  continue;
4126  // Write down how to convert from a derived pointer to a base pointer.
4127  uint32_t OffsetInVBTable = 0;
4128  int32_t VBPtrOffset = -1;
4129  if (Class.VirtualRoot) {
4130  OffsetInVBTable =
4131  VTableContext.getVBTableIndex(MostDerivedClass, Class.VirtualRoot)*4;
4132  VBPtrOffset = MostDerivedLayout.getVBPtrOffset().getQuantity();
4133  }
4134 
4135  // Turn our record back into a pointer if the exception object is a
4136  // pointer.
4137  QualType RTTITy = QualType(Class.RD->getTypeForDecl(), 0);
4138  if (IsPointer)
4139  RTTITy = Context.getPointerType(RTTITy);
4140  CatchableTypes.insert(getCatchableType(RTTITy, Class.OffsetInVBase,
4141  VBPtrOffset, OffsetInVBTable));
4142  }
4143  }
4144 
4145  // C++14 [except.handle]p3:
4146  // A handler is a match for an exception object of type E if
4147  // - The handler is of type cv T or cv T& and E and T are the same type
4148  // (ignoring the top-level cv-qualifiers)
4149  CatchableTypes.insert(getCatchableType(T));
4150 
4151  // C++14 [except.handle]p3:
4152  // A handler is a match for an exception object of type E if
4153  // - the handler is of type cv T or const T& where T is a pointer type and
4154  // E is a pointer type that can be converted to T by [...]
4155  // - a standard pointer conversion (4.10) not involving conversions to
4156  // pointers to private or protected or ambiguous classes
4157  //
4158  // C++14 [conv.ptr]p2:
4159  // A prvalue of type "pointer to cv T," where T is an object type, can be
4160  // converted to a prvalue of type "pointer to cv void".
4161  if (IsPointer && T->getPointeeType()->isObjectType())
4162  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4163 
4164  // C++14 [except.handle]p3:
4165  // A handler is a match for an exception object of type E if [...]
4166  // - the handler is of type cv T or const T& where T is a pointer or
4167  // pointer to member type and E is std::nullptr_t.
4168  //
4169  // We cannot possibly list all possible pointer types here, making this
4170  // implementation incompatible with the standard. However, MSVC includes an
4171  // entry for pointer-to-void in this case. Let's do the same.
4172  if (T->isNullPtrType())
4173  CatchableTypes.insert(getCatchableType(getContext().VoidPtrTy));
4174 
4175  uint32_t NumEntries = CatchableTypes.size();
4176  llvm::Type *CTType =
4177  getImageRelativeType(getCatchableTypeType()->getPointerTo());
4178  llvm::ArrayType *AT = llvm::ArrayType::get(CTType, NumEntries);
4179  llvm::StructType *CTAType = getCatchableTypeArrayType(NumEntries);
4180  llvm::Constant *Fields[] = {
4181  llvm::ConstantInt::get(CGM.IntTy, NumEntries), // NumEntries
4182  llvm::ConstantArray::get(
4183  AT, llvm::makeArrayRef(CatchableTypes.begin(),
4184  CatchableTypes.end())) // CatchableTypes
4185  };
4186  SmallString<256> MangledName;
4187  {
4188  llvm::raw_svector_ostream Out(MangledName);
4189  getMangleContext().mangleCXXCatchableTypeArray(T, NumEntries, Out);
4190  }
4191  CTA = new llvm::GlobalVariable(
4192  CGM.getModule(), CTAType, /*isConstant=*/true, getLinkageForRTTI(T),
4193  llvm::ConstantStruct::get(CTAType, Fields), MangledName);
4194  CTA->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4195  CTA->setSection(".xdata");
4196  if (CTA->isWeakForLinker())
4197  CTA->setComdat(CGM.getModule().getOrInsertComdat(CTA->getName()));
4198  return CTA;
4199 }
4200 
4201 llvm::GlobalVariable *MicrosoftCXXABI::getThrowInfo(QualType T) {
4202  bool IsConst, IsVolatile, IsUnaligned;
4203  T = decomposeTypeForEH(getContext(), T, IsConst, IsVolatile, IsUnaligned);
4204 
4205  // The CatchableTypeArray enumerates the various (CV-unqualified) types that
4206  // the exception object may be caught as.
4207  llvm::GlobalVariable *CTA = getCatchableTypeArray(T);
4208  // The first field in a CatchableTypeArray is the number of CatchableTypes.
4209  // This is used as a component of the mangled name which means that we need to
4210  // know what it is in order to see if we have previously generated the
4211  // ThrowInfo.
4212  uint32_t NumEntries =
4213  cast<llvm::ConstantInt>(CTA->getInitializer()->getAggregateElement(0U))
4214  ->getLimitedValue();
4215 
4216  SmallString<256> MangledName;
4217  {
4218  llvm::raw_svector_ostream Out(MangledName);
4219  getMangleContext().mangleCXXThrowInfo(T, IsConst, IsVolatile, IsUnaligned,
4220  NumEntries, Out);
4221  }
4222 
4223  // Reuse a previously generated ThrowInfo if we have generated an appropriate
4224  // one before.
4225  if (llvm::GlobalVariable *GV = CGM.getModule().getNamedGlobal(MangledName))
4226  return GV;
4227 
4228  // The RTTI TypeDescriptor uses an unqualified type but catch clauses must
4229  // be at least as CV qualified. Encode this requirement into the Flags
4230  // bitfield.
4231  uint32_t Flags = 0;
4232  if (IsConst)
4233  Flags |= 1;
4234  if (IsVolatile)
4235  Flags |= 2;
4236  if (IsUnaligned)
4237  Flags |= 4;
4238 
4239  // The cleanup-function (a destructor) must be called when the exception
4240  // object's lifetime ends.
4241  llvm::Constant *CleanupFn = llvm::Constant::getNullValue(CGM.Int8PtrTy);
4242  if (const CXXRecordDecl *RD = T->getAsCXXRecordDecl())
4243  if (CXXDestructorDecl *DtorD = RD->getDestructor())
4244  if (!DtorD->isTrivial())
4245  CleanupFn = llvm::ConstantExpr::getBitCast(
4247  CGM.Int8PtrTy);
4248  // This is unused as far as we can tell, initialize it to null.
4249  llvm::Constant *ForwardCompat =
4250  getImageRelativeConstant(llvm::Constant::getNullValue(CGM.Int8PtrTy));
4251  llvm::Constant *PointerToCatchableTypes = getImageRelativeConstant(
4252  llvm::ConstantExpr::getBitCast(CTA, CGM.Int8PtrTy));
4253  llvm::StructType *TIType = getThrowInfoType();
4254  llvm::Constant *Fields[] = {
4255  llvm::ConstantInt::get(CGM.IntTy, Flags), // Flags
4256  getImageRelativeConstant(CleanupFn), // CleanupFn
4257  ForwardCompat, // ForwardCompat
4258  PointerToCatchableTypes // CatchableTypeArray
4259  };
4260  auto *GV = new llvm::GlobalVariable(
4261  CGM.getModule(), TIType, /*isConstant=*/true, getLinkageForRTTI(T),
4262  llvm::ConstantStruct::get(TIType, Fields), StringRef(MangledName));
4263  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
4264  GV->setSection(".xdata");
4265  if (GV->isWeakForLinker())
4266  GV->setComdat(CGM.getModule().getOrInsertComdat(GV->getName()));
4267  return GV;
4268 }
4269 
4270 void MicrosoftCXXABI::emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) {
4271  const Expr *SubExpr = E->getSubExpr();
4272  QualType ThrowType = SubExpr->getType();
4273  // The exception object lives on the stack and it's address is passed to the
4274  // runtime function.
4275  Address AI = CGF.CreateMemTemp(ThrowType);
4276  CGF.EmitAnyExprToMem(SubExpr, AI, ThrowType.getQualifiers(),
4277  /*IsInit=*/true);
4278 
4279  // The so-called ThrowInfo is used to describe how the exception object may be
4280  // caught.
4281  llvm::GlobalVariable *TI = getThrowInfo(ThrowType);
4282 
4283  // Call into the runtime to throw the exception.
4284  llvm::Value *Args[] = {
4285  CGF.Builder.CreateBitCast(AI.getPointer(), CGM.Int8PtrTy),
4286  TI
4287  };
4289 }
4290 
4291 std::pair<llvm::Value *, const CXXRecordDecl *>
4292 MicrosoftCXXABI::LoadVTablePtr(CodeGenFunction &CGF, Address This,
4293  const CXXRecordDecl *RD) {
4294  std::tie(This, std::ignore, RD) =
4295  performBaseAdjustment(CGF, This, QualType(RD->getTypeForDecl(), 0));
4296  return {CGF.GetVTablePtr(This, CGM.Int8PtrTy, RD), RD};
4297 }
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:363
void EmitCXXGuardedInitBranch(llvm::Value *NeedsInit, llvm::BasicBlock *InitBlock, llvm::BasicBlock *NoInitBlock, GuardKind Kind, const VarDecl *D)
Emit a branch to select whether or not to perform guarded initialization.
Definition: CGDeclCXX.cpp:300
struct clang::ReturnAdjustment::VirtualAdjustment::@134 Microsoft
static QualType decomposeTypeForEH(ASTContext &Context, QualType T, bool &IsConst, bool &IsVolatile, bool &IsUnaligned)
llvm::IntegerType * IntTy
int
void setSRetAfterThis(bool AfterThis)
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:59
Other implicit parameter.
Definition: Decl.h:1524
Complete object ctor.
Definition: ABI.h:25
A (possibly-)qualified type.
Definition: Type.h:643
static llvm::CallBase * emitRTtypeidCall(CodeGenFunction &CGF, llvm::Value *Argument)
base_class_range bases()
Definition: DeclCXX.h:825
llvm::Type * ConvertTypeForMem(QualType T)
unsigned getNumBases() const
Retrieves the number of base classes of this class.
Definition: DeclCXX.h:819
uint32_t VBPtrOffset
The offset (in bytes) of the vbptr, relative to the beginning of the derived class.
Definition: ABI.h:60
Internal linkage according to the Modules TS, but can be referred to from other translation units ind...
Definition: Linkage.h:49
const Expr * getSubExpr() const
Definition: ExprCXX.h:1071
Address CreateMemTemp(QualType T, const Twine &Name="tmp", Address *Alloca=nullptr)
CreateMemTemp - Create a temporary memory object of the given type, with appropriate alignmen and cas...
Definition: CGExpr.cpp:139
bool isEmpty() const
Definition: ABI.h:154
llvm::LLVMContext & getLLVMContext()
static void detectAmbiguousBases(SmallVectorImpl< MSRTTIClass > &Classes)
Find ambiguity among base classes.
CXXDtorType getDtorType() const
Definition: GlobalDecl.h:84
The standard implementation of ConstantInitBuilder used in Clang.
const ASTRecordLayout & getASTRecordLayout(const RecordDecl *D) const
Get or compute information about the layout of the specified record (struct/union/class) D...
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:505
const llvm::Triple & getTriple() const
Returns the target triple of the primary target.
Definition: TargetInfo.h:991
CharUnits getBaseClassOffset(const CXXRecordDecl *Base) const
getBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:232
No linkage, which means that the entity is unique and can only be referred to from within its scope...
Definition: Linkage.h:26
unsigned getNumVBases() const
Retrieves the number of virtual base classes of this class.
Definition: DeclCXX.h:840
QualType getThisType() const
Return the type of the this pointer.
Definition: DeclCXX.cpp:2275
bool isEmpty() const
Definition: ABI.h:86
const Type * getTypeForDecl() const
Definition: Decl.h:2931
llvm::Constant * getAddrOfCXXStructor(GlobalDecl GD, const CGFunctionInfo *FnInfo=nullptr, llvm::FunctionType *FnType=nullptr, bool DontDefer=false, ForDefinition_t IsForDefinition=NotForDefinition)
Return the address of the constructor/destructor of the given type.
bool isVariadic() const
Whether this function prototype is variadic.
Definition: Type.h:4023
CharUnits VFPtrOffset
This is the offset of the vfptr from the start of the last vbase, or the complete type if there are n...
const CGFunctionInfo & arrangeCXXMethodType(const CXXRecordDecl *RD, const FunctionProtoType *FTP, const CXXMethodDecl *MD)
Arrange the argument and result information for a call to an unknown C++ non-static member function o...
Definition: CGCall.cpp:250
bool isVirtual() const
Definition: DeclCXX.h:2157
const Decl * CurCodeDecl
CurCodeDecl - This is the inner-most code context, which includes blocks.
bool isVirtual() const
Determines whether the base class is a virtual base class (or not).
Definition: DeclCXX.h:245
bool isPOD() const
Whether this class is a POD-type (C++ [class]p4)
Definition: DeclCXX.h:1317
The base class of the type hierarchy.
Definition: Type.h:1418
int64_t NonVirtual
The non-virtual adjustment from the derived object to its nearest virtual base.
Definition: ABI.h:110
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1297
bool isZero() const
isZero - Test whether the quantity equals zero.
Definition: CharUnits.h:115
const NestedNameSpecifier * Specifier
bool isFuncTypeConvertible(const FunctionType *FT)
isFuncTypeConvertible - Utility to check whether a function type can be converted to an LLVM type (i...
Linkage getLinkage() const
Determine the linkage of this type.
Definition: Type.cpp:3696
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:2574
bool TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D)
Try to emit a base destructor as an alias to its primary base-class destructor.
Definition: CGCXX.cpp:33
static llvm::FunctionCallee getInitThreadFooterFn(CodeGenModule &CGM)
Default closure variant of a ctor.
Definition: ABI.h:29
MSInheritanceAttr::Spelling getMSInheritanceModel() const
Returns the inheritance model used for this record.
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2463
const CXXBaseSpecifier *const * path_const_iterator
Definition: Expr.h:3189
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
GlobalDecl getWithCtorType(CXXCtorType Type)
Definition: GlobalDecl.h:123
Represents a variable declaration or definition.
Definition: Decl.h:812
Address getObjectAddress(CodeGenFunction &CGF) const
Returns the address of the object within this declaration.
const CXXRecordDecl * VBase
If nonnull, holds the last vbase which contains the vfptr that the method definition is adjusted to...
const internal::VariadicDynCastAllOfMatcher< Stmt, Expr > expr
Matches expressions.
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6821
A this pointer adjustment.
Definition: ABI.h:107
void EmitCXXDestructorCall(const CXXDestructorDecl *D, CXXDtorType Type, bool ForVirtualBase, bool Delegating, Address This, QualType ThisTy)
Definition: CGClass.cpp:2411
DiagnosticsEngine & getDiags() const
Address CreateConstInBoundsByteGEP(Address Addr, CharUnits Offset, const llvm::Twine &Name="")
Given a pointer to i8, adjust it by a given constant offset.
Definition: CGBuilder.h:244
QualType getMemberPointerType(QualType T, const Type *Cls) const
Return the uniqued reference to the type for a member pointer to the specified type in the specified ...
llvm::Value * getPointer() const
Definition: Address.h:37
A C++ throw-expression (C++ [except.throw]).
Definition: ExprCXX.h:1049
bool hasDefinition() const
Definition: DeclCXX.h:778
Represents a parameter to a function.
Definition: Decl.h:1564
Linkage
Describes the different kinds of linkage (C++ [basic.link], C99 6.2.2) that an entity may have...
Definition: Linkage.h:23
unsigned getAddressSpace() const
Return the address space that this address resides in.
Definition: Address.h:56
void add(RValue rvalue, QualType type)
Definition: CGCall.h:287
const ValueDecl * getMemberPointerDecl() const
Definition: APValue.cpp:772
CharUnits getBaseOffset() const
getBaseOffset - Returns the base class offset.
Definition: BaseSubobject.h:46
int32_t VBOffsetOffset
The offset (in bytes) of the vbase offset in the vbtable.
Definition: ABI.h:131
DeclarationName getDeclName() const
Get the actual, stored name of the declaration, which may be a special name.
Definition: Decl.h:297
One of these records is kept for each identifier that is lexed.
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
virtual void mangleCXXVFTable(const CXXRecordDecl *Derived, ArrayRef< const CXXRecordDecl *> BasePath, raw_ostream &Out)=0
Mangle vftable symbols.
bool ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD)
Returns whether we should perform a type checked load when loading a virtual function for virtual cal...
Definition: CGClass.cpp:2785
bool isReferenceType() const
Definition: Type.h:6366
Denotes a cleanup that should run when a scope is exited using exceptional control flow (a throw stat...
Definition: EHScopeStack.h:80
A return adjustment.
Definition: ABI.h:41
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:52
CharUnits getVBaseClassOffset(const CXXRecordDecl *VBase) const
getVBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:240
__DEVICE__ int max(int __a, int __b)
Expr * getSubExpr()
Definition: Expr.h:3172
void registerGlobalDtorWithAtExit(const VarDecl &D, llvm::FunctionCallee fn, llvm::Constant *addr)
Call atexit() with a function that passes the given argument to the given function.
Definition: CGDeclCXX.cpp:264
Describes a module or submodule.
Definition: Module.h:64
static llvm::FunctionCallee getThrowFn(CodeGenModule &CGM)
IdentifierTable & Idents
Definition: ASTContext.h:569
bool hasPrivateFields() const
Definition: DeclCXX.h:1334
bool hasProtectedFields() const
Definition: DeclCXX.h:1338
static ApplyDebugLocation CreateArtificial(CodeGenFunction &CGF)
Apply TemporaryLocation if it is valid.
Definition: CGDebugInfo.h:742
ArrayRef< ParmVarDecl * > parameters() const
Definition: Decl.h:2289
static bool hasMicrosoftABIRestrictions(const CXXRecordDecl *RD)
ArrayRef< VTableComponent > vtable_components() const
FunctionDecl * getOperatorDelete() const
Definition: ExprCXX.h:2305
Base object ctor.
Definition: ABI.h:26
Address CreateElementBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Cast the element type of the given address to a different type, preserving information like the align...
Definition: CGBuilder.h:156
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:37
void EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD, llvm::Value *VTable, SourceLocation Loc)
If whole-program virtual table optimization is enabled, emit an assumption that VTable is a member of...
Definition: CGClass.cpp:2635
AccessSpecifier getAccessSpecifier() const
Returns the access specifier for this base specifier.
Definition: DeclCXX.h:272
llvm::CallInst * EmitRuntimeCall(llvm::FunctionCallee callee, const Twine &name="")
const CXXRecordDecl * IntroducingObject
This is the class that introduced the vptr by declaring new virtual methods or virtual bases...
path_iterator path_begin()
Definition: Expr.h:3192
Deleting dtor.
Definition: ABI.h:34
CharUnits getAlignment() const
Return the alignment of this pointer.
Definition: Address.h:66
Concrete class used by the front-end to report problems and issues.
Definition: Diagnostic.h:149
static ConstantAddress getInitThreadEpochPtr(CodeGenModule &CGM)
bool isVolatileQualified() const
Determine whether this type is volatile-qualified.
Definition: Type.h:6200
const CGFunctionInfo & arrangeCXXConstructorCall(const CallArgList &Args, const CXXConstructorDecl *D, CXXCtorType CtorKind, unsigned ExtraPrefixArgs, unsigned ExtraSuffixArgs, bool PassProtoArgs=true)
Arrange a call to a C++ method, passing the given arguments.
Definition: CGCall.cpp:389
QualType getExceptionObjectType(QualType T) const
const VPtrInfoVector & getVFPtrOffsets(const CXXRecordDecl *RD)
const Type * getTypePtr() const
Retrieves a pointer to the underlying (unqualified) type.
Definition: Type.h:6130
CXXRecordDecl * getCanonicalDecl() override
Retrieves the "canonical" declaration of the given declaration.
Definition: DeclCXX.h:730
void EmitDeleteCall(const FunctionDecl *DeleteFD, llvm::Value *Ptr, QualType DeleteTy, llvm::Value *NumElements=nullptr, CharUnits CookieSize=CharUnits())
Definition: CGExprCXX.cpp:1754
static bool hasDefaultCXXMethodCC(ASTContext &Context, const CXXMethodDecl *MD)
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
Denotes a cleanup that should run when a scope is exited using normal control flow (falling off the e...
Definition: EHScopeStack.h:84
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3120
void ForceCleanup(std::initializer_list< llvm::Value **> ValuesToReload={})
Force the emission of cleanups now, instead of waiting until this object is destroyed.
const VBaseOffsetsMapTy & getVBaseOffsetsMap() const
Definition: RecordLayout.h:315
const CGFunctionInfo & arrangeCXXMethodDeclaration(const CXXMethodDecl *MD)
C++ methods have some special rules and also have implicit parameters.
Definition: CGCall.cpp:278
GlobalDecl CurGD
CurGD - The GlobalDecl for the current function being compiled.
bool isInstance() const
Definition: DeclCXX.h:2140
CXXDestructorDecl * getDestructor() const
Returns the destructor decl for this class.
Definition: DeclCXX.cpp:1735
GlobalDecl getWithDtorType(CXXDtorType Type)
Definition: GlobalDecl.h:130
struct clang::ThisAdjustment::VirtualAdjustment::@136 Microsoft
CallingConv getDefaultCallingConvention(bool IsVariadic, bool IsCXXMethod, bool IsBuiltin=false) const
Retrieves the default calling convention for the current target.
bool isNegative() const
isNegative - Test whether the quantity is less than zero.
Definition: CharUnits.h:124
CXXRecordDecl * getMostRecentNonInjectedDecl()
Definition: DeclCXX.h:756
static ImplicitParamDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation IdLoc, IdentifierInfo *Id, QualType T, ImplicitParamKind ParamKind)
Create implicit parameter.
Definition: Decl.cpp:4557
NodeId Parent
Definition: ASTDiff.cpp:191
bool hasAttr() const
Definition: DeclBase.h:542
CanQualType getReturnType() const
static void emitGlobalDtorWithTLRegDtor(CodeGenFunction &CGF, const VarDecl &VD, llvm::FunctionCallee Dtor, llvm::Constant *Addr)
AutoVarEmission EmitAutoVarAlloca(const VarDecl &var)
EmitAutoVarAlloca - Emit the alloca and debug information for a local variable.
Definition: CGDecl.cpp:1381
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1636
Represents a prototype with parameter type info, e.g.
Definition: Type.h:3707
void EmitAnyExprToMem(const Expr *E, Address Location, Qualifiers Quals, bool IsInitializer)
EmitAnyExprToMem - Emits the code necessary to evaluate an arbitrary expression into the given memory...
Definition: CGExpr.cpp:223
CastKind
CastKind - The kind of operation required for a conversion.
RValue - This trivial value class is used to represent the result of an expression that is evaluated...
Definition: CGValue.h:38
union clang::ReturnAdjustment::VirtualAdjustment Virtual
Module linkage, which indicates that the entity can be referred to from other translation units withi...
Definition: Linkage.h:55
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:178
unsigned Offset
Definition: Format.cpp:1728
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:38
llvm::Value * GetVTablePtr(Address This, llvm::Type *VTableTy, const CXXRecordDecl *VTableClass)
GetVTablePtr - Return the Value of the vtable pointer member pointed to by This.
Definition: CGClass.cpp:2585
CXXDtorType
C++ destructor types.
Definition: ABI.h:33
Represent the declaration of a variable (in which case it is an lvalue) a function (in which case it ...
Definition: Decl.h:636
This represents one expression.
Definition: Expr.h:108
bool isPositive() const
isPositive - Test whether the quantity is greater than zero.
Definition: CharUnits.h:121
Enters a new scope for capturing cleanups, all of which will be executed once the scope is exited...
void EmitCallArgs(CallArgList &Args, const T *CallArgTypeInfo, llvm::iterator_range< CallExpr::const_arg_iterator > ArgRange, AbstractCallee AC=AbstractCallee(), unsigned ParamsToSkip=0, EvaluationOrder Order=EvaluationOrder::Default)
EmitCallArgs - Emit call arguments for a function.
const CGFunctionInfo & arrangeNullaryFunction()
A nullary function is a freestanding function of type &#39;void ()&#39;.
Definition: CGCall.cpp:694
static llvm::FunctionCallee getInitThreadAbortFn(CodeGenModule &CGM)
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6886
static CGCallee forDirect(llvm::Constant *functionPtr, const CGCalleeInfo &abstractInfo=CGCalleeInfo())
Definition: CGCall.h:133
#define V(N, I)
Definition: ASTContext.h:2898
Represents a C++ destructor within a class.
Definition: DeclCXX.h:2838
VarDecl * getExceptionDecl() const
Definition: StmtCXX.h:49
QualType getTagDeclType(const TagDecl *Decl) const
Return the unique reference to the type for the specified TagDecl (struct/union/class/enum) decl...
bool isNullPtrType() const
Definition: Type.h:6638
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:43
CharUnits getTypeAlignInChars(QualType T) const
Return the ABI-specified alignment of a (complete) type T, in characters.
DeclContext * getDeclContext()
Definition: DeclBase.h:438
TLSKind getTLSKind() const
Definition: Decl.cpp:1970
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:62
MicrosoftVTableContext & getMicrosoftVTableContext()
static bool classifyReturnType(const CGCXXABI &CXXABI, CGFunctionInfo &FI, const ABIInfo &Info)
Definition: TargetInfo.cpp:158
llvm::LLVMContext & getLLVMContext()
const CXXRecordDecl * getBase() const
getBase - Returns the base class declaration.
Definition: BaseSubobject.h:43
bool isPolymorphic() const
Whether this class is polymorphic (C++ [class.virtual]), which means that the class contains or inher...
Definition: DeclCXX.h:1350
Base object dtor.
Definition: ABI.h:36
QualType getType() const
Definition: Expr.h:137
bool hasNonTrivialDestructor() const
Determine whether this class has a non-trivial destructor (C++ [class.dtor]p3)
Definition: DeclCXX.h:1501
bool hasExtendableVFPtr() const
hasVFPtr - Does this class have a virtual function table pointer that can be extended by a derived cl...
Definition: RecordLayout.h:267
DeclContext * getParent()
getParent - Returns the containing DeclContext.
Definition: DeclBase.h:1772
void GenerateCXXGlobalInitFunc(llvm::Function *Fn, ArrayRef< llvm::Function *> CXXThreadLocals, ConstantAddress Guard=ConstantAddress::invalid())
GenerateCXXGlobalInitFunc - Generates code for initializing global variables.
Definition: CGDeclCXX.cpp:667
llvm::Value * EmitCastToVoidPtr(llvm::Value *value)
Emit a cast to void* in the appropriate address space.
Definition: CGExpr.cpp:50
CharUnits getVBPtrOffset() const
getVBPtrOffset - Get the offset for virtual base table pointer.
Definition: RecordLayout.h:305
const TargetInfo & getTarget() const
void EmitCXXGlobalVarDeclInit(const VarDecl &D, llvm::Constant *DeclPtr, bool PerformInit)
EmitCXXGlobalVarDeclInit - Create the initializer for a C++ variable with global storage.
Definition: CGDeclCXX.cpp:175
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:1389
ASTContext & getContext() const
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:708
bool nullFieldOffsetIsZero() const
In the Microsoft C++ ABI, use zero for the field offset of a null data member pointer if we can guara...
Definition: DeclCXX.h:1960
The COMDAT used for dtors.
Definition: ABI.h:37
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:264
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:40
bool isConstQualified() const
Determine whether this type is const-qualified.
Definition: Type.h:6189
The l-value was considered opaque, so the alignment was determined from a type.
int64_t NonVirtual
The non-virtual adjustment from the derived object to its nearest virtual base.
Definition: ABI.h:44
unsigned getVBTableIndex(const CXXRecordDecl *Derived, const CXXRecordDecl *VBase)
Returns the index of VBase in the vbtable of Derived.
unsigned getEffectiveCallingConvention() const
getEffectiveCallingConvention - Return the actual calling convention to use, which may depend on the ...
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:141
static llvm::FunctionCallee getInitThreadHeaderFn(CodeGenModule &CGM)
Encodes a location in the source.
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
bool isMemberDataPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2806
Address CreateConstInBoundsGEP2_32(Address Addr, unsigned Idx0, unsigned Idx1, const llvm::Twine &Name="")
Definition: CGBuilder.h:258
CastKind getCastKind() const
Definition: Expr.h:3166
RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee, ReturnValueSlot ReturnValue, const CallArgList &Args, llvm::CallBase **callOrInvoke, SourceLocation Loc)
EmitCall - Generate a call of the given function, expecting the given result type, and using the given argument list which specifies both the LLVM arguments and the types they were derived from.
Definition: CGCall.cpp:3779
Represents a new-expression for memory allocation and constructor calls, e.g: "new CXXNewExpr(foo)"...
Definition: ExprCXX.h:2005
Represents a call to a member function that may be written either with member call syntax (e...
Definition: ExprCXX.h:170
ASTContext & getASTContext() const LLVM_READONLY
Definition: DeclBase.cpp:376
static bool IsSizeGreaterThan128(const CXXRecordDecl *RD)
const Decl * getDecl() const
Definition: GlobalDecl.h:77
Represents a single component in a vtable.
Definition: VTableBuilder.h:29
MangleContext - Context for tracking state which persists across multiple calls to the C++ name mangl...
Definition: Mangle.h:43
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2114
const VTableLayout & getVFTableLayout(const CXXRecordDecl *RD, CharUnits VFPtrOffset)
QualType getAllocatedType() const
Definition: ExprCXX.h:2098
llvm::Constant * GetAddrOfRTTIDescriptor(QualType Ty, bool ForEH=false)
Get the address of the RTTI descriptor for the given type.
void createVTableInitializer(ConstantStructBuilder &builder, const VTableLayout &layout, llvm::Constant *rtti)
Add vtable components for the given vtable layout to the given global initializer.
Definition: CGVTables.cpp:710
const CXXRecordDecl * ObjectWithVPtr
This is the most derived class that has this vptr at offset zero.
An aligned address.
Definition: Address.h:24
void StartFunction(GlobalDecl GD, QualType RetTy, llvm::Function *Fn, const CGFunctionInfo &FnInfo, const FunctionArgList &Args, SourceLocation Loc=SourceLocation(), SourceLocation StartLoc=SourceLocation())
Emit code for the start of a function.
DestructionKind isDestructedType() const
Returns a nonzero value if objects of this type require non-trivial work to clean up after...
Definition: Type.h:1163
unsigned getCustomDiagID(Level L, const char(&FormatString)[N])
Return an ID for a diagnostic with the specified format string and level.
Definition: Diagnostic.h:778
All available information about a concrete callee.
Definition: CGCall.h:66
bool canPassInRegisters() const
Determine whether this class can be passed in registers.
Definition: Decl.h:3752
MangleContext & getMangleContext()
Gets the mangle context.
Definition: CGCXXABI.h:96
Complete object dtor.
Definition: ABI.h:35
llvm::Instruction * CurrentFuncletPad
constexpr XRayInstrMask None
Definition: XRayInstr.h:37
CGCXXABI * CreateMicrosoftCXXABI(CodeGenModule &CGM)
Creates a Microsoft-family ABI.
static void mangleVFTableName(MicrosoftMangleContext &MangleContext, const CXXRecordDecl *RD, const VPtrInfo &VFPtr, SmallString< 256 > &Name)
bool isMemberPointerToDerivedMember() const
Definition: APValue.cpp:779
The MS C++ ABI needs a pointer to RTTI data plus some flags to describe the type of a catch handler...
Definition: CGCleanup.h:37
void FinishFunction(SourceLocation EndLoc=SourceLocation())
FinishFunction - Complete IR generation of the current function.
CXXCtorType
C++ constructor types.
Definition: ABI.h:24
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:215
void addUsedGlobal(llvm::GlobalValue *GV)
Add a global to a list to be added to the llvm.used metadata.
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:358
llvm::Value * getScalarVal() const
getScalarVal() - Return the Value* of this scalar value.
Definition: CGValue.h:58
CXXRecordDecl * getMostRecentCXXRecordDecl() const
Definition: Type.cpp:4127
bool isVirtuallyDerivedFrom(const CXXRecordDecl *Base) const
Determine whether this class is virtually derived from the class Base.
void ErrorUnsupported(const Stmt *S, const char *Type)
Print out an error that codegen doesn&#39;t support the specified stmt yet.
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
CharUnits alignmentAtOffset(CharUnits offset) const
Given that this is a non-zero alignment value, what is the alignment at the given offset...
Definition: CharUnits.h:189
llvm::GlobalValue * GetGlobalValue(StringRef Ref)
Dataflow Directional Tag Classes.
External linkage within a unique namespace.
Definition: Linkage.h:40
static bool isDeletingDtor(GlobalDecl GD)
uint64_t Index
Method&#39;s index in the vftable.
Represents a delete expression for memory deallocation and destructor calls, e.g. ...
Definition: ExprCXX.h:2265
const VPtrInfoVector & enumerateVBTables(const CXXRecordDecl *RD)
llvm::LoadInst * CreateAlignedLoad(llvm::Value *Addr, CharUnits Align, const llvm::Twine &Name="")
Definition: CGBuilder.h:90
llvm::Constant * getPointer() const
Definition: Address.h:83
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:69
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2237
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:2776
CharUnits NonVirtualOffset
IntroducingObject is at this offset from its containing complete object or virtual base...
llvm::StoreInst * CreateStore(llvm::Value *Val, Address Addr, bool IsVolatile=false)
Definition: CGBuilder.h:107
llvm::Module & getModule() const
void maybeSetTrivialComdat(const Decl &D, llvm::GlobalObject &GO)
CharUnits getVBaseAlignment(CharUnits DerivedAlign, const CXXRecordDecl *Derived, const CXXRecordDecl *VBase)
Returns the assumed alignment of a virtual base of a class.
Definition: CGClass.cpp:55
ArrayRef< const CXXRecordDecl * > getMemberPointerPath() const
Definition: APValue.cpp:786
llvm::Function * createAtExitStub(const VarDecl &VD, llvm::FunctionCallee Dtor, llvm::Constant *Addr)
Create a stub function, suitable for being passed to atexit, which passes the given address to the gi...
Definition: CGDeclCXX.cpp:231
union clang::ThisAdjustment::VirtualAdjustment Virtual
bool hasNonTrivialCopyAssignment() const
Determine whether this class has a non-trivial copy assignment operator (C++ [class.copy]p11, C++11 [class.copy]p25)
Definition: DeclCXX.h:1469
path_iterator path_end()
Definition: Expr.h:3193
void EmitAutoVarCleanups(const AutoVarEmission &emission)
Definition: CGDecl.cpp:1984
void EmitNoreturnRuntimeCallOrInvoke(llvm::FunctionCallee callee, ArrayRef< llvm::Value *> args)
Emits a call or invoke to the given noreturn runtime function.
Definition: CGCall.cpp:3708
void AppendLinkerOptions(StringRef Opts)
Appends Opts to the "llvm.linker.options" metadata value.
static llvm::GlobalVariable * getTypeInfoVTable(CodeGenModule &CGM)
StructBuilder beginStruct(llvm::StructType *structTy=nullptr)
const CXXRecordDecl * getVBaseWithVPtr() const
The vptr is stored inside the non-virtual component of this virtual base.
Implements C++ ABI-specific code generation functions.
Definition: CGCXXABI.h:43
This class organizes the cross-module state that is used while lowering AST types to LLVM types...
Definition: CodeGenTypes.h:59
bool isStaticLocal() const
Returns true if a variable with function scope is a static local variable.
Definition: Decl.h:1059
llvm::Constant * GetAddrOfFunction(GlobalDecl GD, llvm::Type *Ty=nullptr, bool ForVTable=false, bool DontDefer=false, ForDefinition_t IsForDefinition=NotForDefinition)
Return the address of the given function.
StringRef getMangledName(GlobalDecl GD)
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:31
llvm::FunctionCallee CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeList ExtraAttrs=llvm::AttributeList(), bool Local=false)
Create or return a runtime function declaration with the specified type and name. ...
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:454
APValue - This class implements a discriminated union of [uninitialized] [APSInt] [APFloat]...
Definition: APValue.h:76
Represents a base class of a C++ class.
Definition: DeclCXX.h:192
bool isObjectType() const
Determine whether this type is an object type.
Definition: Type.h:1879
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2070
static CGCXXABI::RecordArgABI getRecordArgABI(const RecordType *RT, CGCXXABI &CXXABI)
Definition: TargetInfo.cpp:139
const Decl * CurFuncDecl
CurFuncDecl - Holds the Decl for the current outermost non-closure context.
uint64_t getFieldOffset(const ValueDecl *FD) const
Get the offset of a FieldDecl or IndirectFieldDecl, in bits.
CharUnits toCharUnitsFromBits(int64_t BitSize) const
Convert a size in bits to a size in characters.
Defines the C++ Decl subclasses, other than those for templates (found in DeclTemplate.h) and friends (in DeclFriend.h).
static bool isInstanceMethod(const Decl *D)
QualType getUnqualifiedType() const
Retrieve the unqualified variant of the given type, removing as little sugar as possible.
Definition: Type.h:6210
Address CreateConstByteGEP(Address Addr, CharUnits Offset, const llvm::Twine &Name="")
Definition: CGBuilder.h:250
bool hasUnaligned() const
Definition: Type.h:293
Represents a C++ struct/union/class.
Definition: DeclCXX.h:300
bool isMemberFunctionPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2800
llvm::Function * CreateGlobalInitOrDestructFunction(llvm::FunctionType *ty, const Twine &name, const CGFunctionInfo &FI, SourceLocation Loc=SourceLocation(), bool TLS=false)
Definition: CGDeclCXX.cpp:337
CXXCatchStmt - This represents a C++ catch block.
Definition: StmtCXX.h:28
llvm::Type * ConvertType(QualType T)
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:6157
A specialization of Address that requires the address to be an LLVM Constant.
Definition: Address.h:74
int32_t VtordispOffset
The offset of the vtordisp (in bytes), relative to the ECX.
Definition: ABI.h:124
Address ReturnValue
ReturnValue - The temporary alloca to hold the return value.
No linkage according to the standard, but is visible from other translation units because of types de...
Definition: Linkage.h:44
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
static CGCallee forVirtual(const CallExpr *CE, GlobalDecl MD, Address Addr, llvm::FunctionType *FTy)
Definition: CGCall.h:144
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:251
llvm::DenseMap< const CXXRecordDecl *, VBaseInfo > VBaseOffsetsMapTy
Definition: RecordLayout.h:59
bool isGlobalDelete() const
Definition: ExprCXX.h:2291
Copying closure variant of a ctor.
Definition: ABI.h:28
CharUnits computeNonVirtualBaseClassOffset(const CXXRecordDecl *DerivedClass, CastExpr::path_const_iterator Start, CastExpr::path_const_iterator End)
Definition: CGClass.cpp:149
CharUnits FullOffsetInMDC
Static offset from the top of the most derived class to this vfptr, including any virtual base offset...
const CGFunctionInfo & arrangeMSCtorClosure(const CXXConstructorDecl *CD, CXXCtorType CT)
Definition: CGCall.cpp:539
CanQualType IntTy
Definition: ASTContext.h:1011
Struct with all information about dynamic [sub]class needed to set vptr.
void initialize(TemplateInstantiationCallbackPtrs &Callbacks, const Sema &TheSema)
llvm::Function * codegenCXXStructor(GlobalDecl GD)
Definition: CGCXX.cpp:206
MethodVFTableLocation getMethodVFTableLocation(GlobalDecl GD)
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
GVALinkage
A more specific kind of linkage than enum Linkage.
Definition: Linkage.h:73
Holds information about the inheritance path to a virtual base or function table pointer.
bool isPointerType() const
Definition: Type.h:6354
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
static ApplyDebugLocation CreateEmpty(CodeGenFunction &CGF)
Set the IRBuilder to not attach debug locations.
Definition: CGDebugInfo.h:759
llvm::StoreInst * CreateAlignedStore(llvm::Value *Val, llvm::Value *Addr, CharUnits Align, bool IsVolatile=false)
Definition: CGBuilder.h:114
QualType getType() const
Definition: Decl.h:647
uint32_t VBIndex
Index of the virtual base in the vbtable.
Definition: ABI.h:63
LValue - This represents an lvalue references.
Definition: CGValue.h:166
Information for lazily generating a cleanup.
Definition: EHScopeStack.h:146
This represents a decl that may have a name.
Definition: Decl.h:248
void EmitMustTailThunk(GlobalDecl GD, llvm::Value *AdjustedThisPtr, llvm::FunctionCallee Callee)
Emit a musttail call for a thunk with a potentially adjusted this pointer.
Definition: CGVTables.cpp:376
BasePath PathToIntroducingObject
This holds the base classes path from the complete type to the first base with the given vfptr offset...
const CXXConstructorDecl * getCopyConstructorForExceptionObject(CXXRecordDecl *RD)
bool CurFuncIsThunk
In C++, whether we are code generating a thunk.
Notes how many arguments were added to the beginning (Prefix) and ending (Suffix) of an arg list...
Definition: CGCXXABI.h:295
RecordArgABI
Specify how one should pass an argument of a record type.
Definition: CGCXXABI.h:125
llvm::CallInst * EmitNounwindRuntimeCall(llvm::FunctionCallee callee, const Twine &name="")
llvm::CallBase * EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee, ArrayRef< llvm::Value *> args, const Twine &name="")
Emits a call or invoke instruction to the given runtime function.
Definition: CGCall.cpp:3739
unsigned getNumParams() const
Return the number of parameters this function must have based on its FunctionType.
Definition: Decl.cpp:3138
ctor_range ctors() const
Definition: DeclCXX.h:887
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:262
int32_t VBPtrOffset
The offset of the vbptr of the derived class (in bytes), relative to the ECX after vtordisp adjustmen...
Definition: ABI.h:128
void PopCleanupBlock(bool FallThroughIsBranchThrough=false)
PopCleanupBlock - Will pop the cleanup entry on the stack and process all branch fixups.
Definition: CGCleanup.cpp:644
static void serializeClassHierarchy(SmallVectorImpl< MSRTTIClass > &Classes, const CXXRecordDecl *RD)
Recursively serializes a class hierarchy in pre-order depth first order.
base_class_range vbases()
Definition: DeclCXX.h:842
static ABIArgInfo getIndirect(CharUnits Alignment, bool ByVal=true, bool Realign=false, llvm::Type *Padding=nullptr)
llvm::Value * EmitVTableTypeCheckedLoad(const CXXRecordDecl *RD, llvm::Value *VTable, uint64_t VTableByteOffset)
Emit a type checked load from the given vtable.
Definition: CGClass.cpp:2797
SourceLocation getLocation() const
Definition: DeclBase.h:429
QualType getPointeeType() const
Definition: Type.h:2796
bool isExternallyVisible() const
Definition: Decl.h:379
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
CanQualType getSizeType() const
Return the unique type for "size_t" (C99 7.17), defined in <stddef.h>.
llvm::FunctionType * GetFunctionType(const CGFunctionInfo &Info)
GetFunctionType - Get the LLVM function type for.
Definition: CGCall.cpp:1541
bool isNoDestroy(const ASTContext &) const
Do we need to emit an exit-time destructor for this variable?
Definition: Decl.cpp:2562