Coverage Report

Created: 2020-02-15 09:57

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/CodeGen/CGCXXABI.h
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//===----- CGCXXABI.h - Interface to C++ ABIs -------------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This provides an abstract class for C++ code generation. Concrete subclasses
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// of this implement code generation for specific C++ ABIs.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_LIB_CODEGEN_CGCXXABI_H
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#define LLVM_CLANG_LIB_CODEGEN_CGCXXABI_H
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17
#include "CodeGenFunction.h"
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#include "clang/Basic/LLVM.h"
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20
namespace llvm {
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class Constant;
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class Type;
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class Value;
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class CallInst;
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}
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27
namespace clang {
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class CastExpr;
29
class CXXConstructorDecl;
30
class CXXDestructorDecl;
31
class CXXMethodDecl;
32
class CXXRecordDecl;
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class FieldDecl;
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class MangleContext;
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namespace CodeGen {
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class CGCallee;
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class CodeGenFunction;
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class CodeGenModule;
40
struct CatchTypeInfo;
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/// Implements C++ ABI-specific code generation functions.
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class CGCXXABI {
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protected:
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  CodeGenModule &CGM;
46
  std::unique_ptr<MangleContext> MangleCtx;
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48
  CGCXXABI(CodeGenModule &CGM)
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25.7k
    : CGM(CGM), MangleCtx(CGM.getContext().createMangleContext()) {}
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51
protected:
52
177k
  ImplicitParamDecl *getThisDecl(CodeGenFunction &CGF) {
53
177k
    return CGF.CXXABIThisDecl;
54
177k
  }
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2.03k
  llvm::Value *getThisValue(CodeGenFunction &CGF) {
56
2.03k
    return CGF.CXXABIThisValue;
57
2.03k
  }
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902
  Address getThisAddress(CodeGenFunction &CGF) {
59
902
    return Address(CGF.CXXABIThisValue, CGF.CXXABIThisAlignment);
60
902
  }
61
62
  /// Issue a diagnostic about unsupported features in the ABI.
63
  void ErrorUnsupportedABI(CodeGenFunction &CGF, StringRef S);
64
65
  /// Get a null value for unsupported member pointers.
66
  llvm::Constant *GetBogusMemberPointer(QualType T);
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68
87.8k
  ImplicitParamDecl *&getStructorImplicitParamDecl(CodeGenFunction &CGF) {
69
87.8k
    return CGF.CXXStructorImplicitParamDecl;
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87.8k
  }
71
1.42k
  llvm::Value *&getStructorImplicitParamValue(CodeGenFunction &CGF) {
72
1.42k
    return CGF.CXXStructorImplicitParamValue;
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1.42k
  }
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75
  /// Loads the incoming C++ this pointer as it was passed by the caller.
76
  llvm::Value *loadIncomingCXXThis(CodeGenFunction &CGF);
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78
  void setCXXABIThisValue(CodeGenFunction &CGF, llvm::Value *ThisPtr);
79
80
339k
  ASTContext &getContext() const { return CGM.getContext(); }
81
82
  virtual bool requiresArrayCookie(const CXXDeleteExpr *E, QualType eltType);
83
  virtual bool requiresArrayCookie(const CXXNewExpr *E);
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85
  /// Determine whether there's something special about the rules of
86
  /// the ABI tell us that 'this' is a complete object within the
87
  /// given function.  Obvious common logic like being defined on a
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  /// final class will have been taken care of by the caller.
89
  virtual bool isThisCompleteObject(GlobalDecl GD) const = 0;
90
91
public:
92
93
  virtual ~CGCXXABI();
94
95
  /// Gets the mangle context.
96
2.73M
  MangleContext &getMangleContext() {
97
2.73M
    return *MangleCtx;
98
2.73M
  }
99
100
  /// Returns true if the given constructor or destructor is one of the
101
  /// kinds that the ABI says returns 'this' (only applies when called
102
  /// non-virtually for destructors).
103
  ///
104
  /// There currently is no way to indicate if a destructor returns 'this'
105
  /// when called virtually, and code generation does not support the case.
106
671k
  virtual bool HasThisReturn(GlobalDecl GD) const { return false; }
107
108
371k
  virtual bool hasMostDerivedReturn(GlobalDecl GD) const { return false; }
109
110
  /// Returns true if the target allows calling a function through a pointer
111
  /// with a different signature than the actual function (or equivalently,
112
  /// bitcasting a function or function pointer to a different function type).
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  /// In principle in the most general case this could depend on the target, the
114
  /// calling convention, and the actual types of the arguments and return
115
  /// value. Here it just means whether the signature mismatch could *ever* be
116
  /// allowed; in other words, does the target do strict checking of signatures
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  /// for all calls.
118
7
  virtual bool canCallMismatchedFunctionType() const { return true; }
119
120
  /// If the C++ ABI requires the given type be returned in a particular way,
121
  /// this method sets RetAI and returns true.
122
  virtual bool classifyReturnType(CGFunctionInfo &FI) const = 0;
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124
  /// Specify how one should pass an argument of a record type.
125
  enum RecordArgABI {
126
    /// Pass it using the normal C aggregate rules for the ABI, potentially
127
    /// introducing extra copies and passing some or all of it in registers.
128
    RAA_Default = 0,
129
130
    /// Pass it on the stack using its defined layout.  The argument must be
131
    /// evaluated directly into the correct stack position in the arguments area,
132
    /// and the call machinery must not move it or introduce extra copies.
133
    RAA_DirectInMemory,
134
135
    /// Pass it as a pointer to temporary memory.
136
    RAA_Indirect
137
  };
138
139
  /// Returns how an argument of the given record type should be passed.
140
  virtual RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const = 0;
141
142
  /// Returns true if the implicit 'sret' parameter comes after the implicit
143
  /// 'this' parameter of C++ instance methods.
144
0
  virtual bool isSRetParameterAfterThis() const { return false; }
145
146
  /// Find the LLVM type used to represent the given member pointer
147
  /// type.
148
  virtual llvm::Type *
149
  ConvertMemberPointerType(const MemberPointerType *MPT);
150
151
  /// Load a member function from an object and a member function
152
  /// pointer.  Apply the this-adjustment and set 'This' to the
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  /// adjusted value.
154
  virtual CGCallee EmitLoadOfMemberFunctionPointer(
155
      CodeGenFunction &CGF, const Expr *E, Address This,
156
      llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
157
      const MemberPointerType *MPT);
158
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  /// Calculate an l-value from an object and a data member pointer.
160
  virtual llvm::Value *
161
  EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
162
                               Address Base, llvm::Value *MemPtr,
163
                               const MemberPointerType *MPT);
164
165
  /// Perform a derived-to-base, base-to-derived, or bitcast member
166
  /// pointer conversion.
167
  virtual llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
168
                                                   const CastExpr *E,
169
                                                   llvm::Value *Src);
170
171
  /// Perform a derived-to-base, base-to-derived, or bitcast member
172
  /// pointer conversion on a constant value.
173
  virtual llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
174
                                                      llvm::Constant *Src);
175
176
  /// Return true if the given member pointer can be zero-initialized
177
  /// (in the C++ sense) with an LLVM zeroinitializer.
178
  virtual bool isZeroInitializable(const MemberPointerType *MPT);
179
180
  /// Return whether or not a member pointers type is convertible to an IR type.
181
460
  virtual bool isMemberPointerConvertible(const MemberPointerType *MPT) const {
182
460
    return true;
183
460
  }
184
185
  /// Create a null member pointer of the given type.
186
  virtual llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT);
187
188
  /// Create a member pointer for the given method.
189
  virtual llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD);
190
191
  /// Create a member pointer for the given field.
192
  virtual llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
193
                                                CharUnits offset);
194
195
  /// Create a member pointer for the given member pointer constant.
196
  virtual llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT);
197
198
  /// Emit a comparison between two member pointers.  Returns an i1.
199
  virtual llvm::Value *
200
  EmitMemberPointerComparison(CodeGenFunction &CGF,
201
                              llvm::Value *L,
202
                              llvm::Value *R,
203
                              const MemberPointerType *MPT,
204
                              bool Inequality);
205
206
  /// Determine if a member pointer is non-null.  Returns an i1.
207
  virtual llvm::Value *
208
  EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
209
                             llvm::Value *MemPtr,
210
                             const MemberPointerType *MPT);
211
212
protected:
213
  /// A utility method for computing the offset required for the given
214
  /// base-to-derived or derived-to-base member-pointer conversion.
215
  /// Does not handle virtual conversions (in case we ever fully
216
  /// support an ABI that allows this).  Returns null if no adjustment
217
  /// is required.
218
  llvm::Constant *getMemberPointerAdjustment(const CastExpr *E);
219
220
  /// Computes the non-virtual adjustment needed for a member pointer
221
  /// conversion along an inheritance path stored in an APValue.  Unlike
222
  /// getMemberPointerAdjustment(), the adjustment can be negative if the path
223
  /// is from a derived type to a base type.
224
  CharUnits getMemberPointerPathAdjustment(const APValue &MP);
225
226
public:
227
  virtual void emitVirtualObjectDelete(CodeGenFunction &CGF,
228
                                       const CXXDeleteExpr *DE,
229
                                       Address Ptr, QualType ElementType,
230
                                       const CXXDestructorDecl *Dtor) = 0;
231
  virtual void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) = 0;
232
  virtual void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) = 0;
233
0
  virtual llvm::GlobalVariable *getThrowInfo(QualType T) { return nullptr; }
234
235
  /// Determine whether it's possible to emit a vtable for \p RD, even
236
  /// though we do not know that the vtable has been marked as used by semantic
237
  /// analysis.
238
  virtual bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const = 0;
239
240
  virtual void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) = 0;
241
242
  virtual llvm::CallInst *
243
  emitTerminateForUnexpectedException(CodeGenFunction &CGF,
244
                                      llvm::Value *Exn);
245
246
  virtual llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) = 0;
247
  virtual CatchTypeInfo
248
  getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) = 0;
249
  virtual CatchTypeInfo getCatchAllTypeInfo();
250
251
  virtual bool shouldTypeidBeNullChecked(bool IsDeref,
252
                                         QualType SrcRecordTy) = 0;
253
  virtual void EmitBadTypeidCall(CodeGenFunction &CGF) = 0;
254
  virtual llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
255
                                  Address ThisPtr,
256
                                  llvm::Type *StdTypeInfoPtrTy) = 0;
257
258
  virtual bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
259
                                                  QualType SrcRecordTy) = 0;
260
261
  virtual llvm::Value *
262
  EmitDynamicCastCall(CodeGenFunction &CGF, Address Value,
263
                      QualType SrcRecordTy, QualType DestTy,
264
                      QualType DestRecordTy, llvm::BasicBlock *CastEnd) = 0;
265
266
  virtual llvm::Value *EmitDynamicCastToVoid(CodeGenFunction &CGF,
267
                                             Address Value,
268
                                             QualType SrcRecordTy,
269
                                             QualType DestTy) = 0;
270
271
  virtual bool EmitBadCastCall(CodeGenFunction &CGF) = 0;
272
273
  virtual llvm::Value *GetVirtualBaseClassOffset(CodeGenFunction &CGF,
274
                                                 Address This,
275
                                                 const CXXRecordDecl *ClassDecl,
276
                                        const CXXRecordDecl *BaseClassDecl) = 0;
277
278
  virtual llvm::BasicBlock *EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
279
                                                          const CXXRecordDecl *RD);
280
281
  /// Emit the code to initialize hidden members required
282
  /// to handle virtual inheritance, if needed by the ABI.
283
  virtual void
284
  initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
285
399
                                            const CXXRecordDecl *RD) {}
286
287
  /// Emit constructor variants required by this ABI.
288
  virtual void EmitCXXConstructors(const CXXConstructorDecl *D) = 0;
289
290
  /// Notes how many arguments were added to the beginning (Prefix) and ending
291
  /// (Suffix) of an arg list.
292
  ///
293
  /// Note that Prefix actually refers to the number of args *after* the first
294
  /// one: `this` arguments always come first.
295
  struct AddedStructorArgs {
296
    unsigned Prefix = 0;
297
    unsigned Suffix = 0;
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299k
    AddedStructorArgs() = default;
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1.71k
    AddedStructorArgs(unsigned P, unsigned S) : Prefix(P), Suffix(S) {}
300
1.23k
    static AddedStructorArgs prefix(unsigned N) { return {N, 0}; }
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472
    static AddedStructorArgs suffix(unsigned N) { return {0, N}; }
302
  };
303
304
  /// Build the signature of the given constructor or destructor variant by
305
  /// adding any required parameters.  For convenience, ArgTys has been
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  /// initialized with the type of 'this'.
307
  virtual AddedStructorArgs
308
  buildStructorSignature(GlobalDecl GD,
309
                         SmallVectorImpl<CanQualType> &ArgTys) = 0;
310
311
  /// Returns true if the given destructor type should be emitted as a linkonce
312
  /// delegating thunk, regardless of whether the dtor is defined in this TU or
313
  /// not.
314
  virtual bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
315
                                      CXXDtorType DT) const = 0;
316
317
  virtual void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
318
                                          const CXXDestructorDecl *Dtor,
319
                                          CXXDtorType DT) const;
320
321
  virtual llvm::GlobalValue::LinkageTypes
322
  getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
323
                          CXXDtorType DT) const;
324
325
  /// Emit destructor variants required by this ABI.
326
  virtual void EmitCXXDestructors(const CXXDestructorDecl *D) = 0;
327
328
  /// Get the type of the implicit "this" parameter used by a method. May return
329
  /// zero if no specific type is applicable, e.g. if the ABI expects the "this"
330
  /// parameter to point to some artificial offset in a complete object due to
331
  /// vbases being reordered.
332
  virtual const CXXRecordDecl *
333
269k
  getThisArgumentTypeForMethod(const CXXMethodDecl *MD) {
334
269k
    return MD->getParent();
335
269k
  }
336
337
  /// Perform ABI-specific "this" argument adjustment required prior to
338
  /// a call of a virtual function.
339
  /// The "VirtualCall" argument is true iff the call itself is virtual.
340
  virtual Address
341
  adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
342
1.11k
                                           Address This, bool VirtualCall) {
343
1.11k
    return This;
344
1.11k
  }
345
346
  /// Build a parameter variable suitable for 'this'.
347
  void buildThisParam(CodeGenFunction &CGF, FunctionArgList &Params);
348
349
  /// Insert any ABI-specific implicit parameters into the parameter list for a
350
  /// function.  This generally involves extra data for constructors and
351
  /// destructors.
352
  ///
353
  /// ABIs may also choose to override the return type, which has been
354
  /// initialized with the type of 'this' if HasThisReturn(CGF.CurGD) is true or
355
  /// the formal return type of the function otherwise.
356
  virtual void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
357
                                         FunctionArgList &Params) = 0;
358
359
  /// Get the ABI-specific "this" parameter adjustment to apply in the prologue
360
  /// of a virtual function.
361
0
  virtual CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
362
0
    return CharUnits::Zero();
363
0
  }
364
365
  /// Emit the ABI-specific prolog for the function.
366
  virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0;
367
368
  /// Add any ABI-specific implicit arguments needed to call a constructor.
369
  ///
370
  /// \return The number of arguments added at the beginning and end of the
371
  /// call, which is typically zero or one.
372
  virtual AddedStructorArgs
373
  addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
374
                             CXXCtorType Type, bool ForVirtualBase,
375
                             bool Delegating, CallArgList &Args) = 0;
376
377
  /// Emit the destructor call.
378
  virtual void EmitDestructorCall(CodeGenFunction &CGF,
379
                                  const CXXDestructorDecl *DD, CXXDtorType Type,
380
                                  bool ForVirtualBase, bool Delegating,
381
                                  Address This, QualType ThisTy) = 0;
382
383
  /// Emits the VTable definitions required for the given record type.
384
  virtual void emitVTableDefinitions(CodeGenVTables &CGVT,
385
                                     const CXXRecordDecl *RD) = 0;
386
387
  /// Checks if ABI requires extra virtual offset for vtable field.
388
  virtual bool
389
  isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
390
                                      CodeGenFunction::VPtr Vptr) = 0;
391
392
  /// Checks if ABI requires to initialize vptrs for given dynamic class.
393
  virtual bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) = 0;
394
395
  /// Get the address point of the vtable for the given base subobject.
396
  virtual llvm::Constant *
397
  getVTableAddressPoint(BaseSubobject Base,
398
                        const CXXRecordDecl *VTableClass) = 0;
399
400
  /// Get the address point of the vtable for the given base subobject while
401
  /// building a constructor or a destructor.
402
  virtual llvm::Value *
403
  getVTableAddressPointInStructor(CodeGenFunction &CGF, const CXXRecordDecl *RD,
404
                                  BaseSubobject Base,
405
                                  const CXXRecordDecl *NearestVBase) = 0;
406
407
  /// Get the address point of the vtable for the given base subobject while
408
  /// building a constexpr.
409
  virtual llvm::Constant *
410
  getVTableAddressPointForConstExpr(BaseSubobject Base,
411
                                    const CXXRecordDecl *VTableClass) = 0;
412
413
  /// Get the address of the vtable for the given record decl which should be
414
  /// used for the vptr at the given offset in RD.
415
  virtual llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
416
                                                CharUnits VPtrOffset) = 0;
417
418
  /// Build a virtual function pointer in the ABI-specific way.
419
  virtual CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF,
420
                                             GlobalDecl GD, Address This,
421
                                             llvm::Type *Ty,
422
                                             SourceLocation Loc) = 0;
423
424
  using DeleteOrMemberCallExpr =
425
      llvm::PointerUnion<const CXXDeleteExpr *, const CXXMemberCallExpr *>;
426
427
  /// Emit the ABI-specific virtual destructor call.
428
  virtual llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
429
                                                 const CXXDestructorDecl *Dtor,
430
                                                 CXXDtorType DtorType,
431
                                                 Address This,
432
                                                 DeleteOrMemberCallExpr E) = 0;
433
434
  virtual void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF,
435
                                                GlobalDecl GD,
436
149
                                                CallArgList &CallArgs) {}
437
438
  /// Emit any tables needed to implement virtual inheritance.  For Itanium,
439
  /// this emits virtual table tables.  For the MSVC++ ABI, this emits virtual
440
  /// base tables.
441
  virtual void emitVirtualInheritanceTables(const CXXRecordDecl *RD) = 0;
442
443
  virtual bool exportThunk() = 0;
444
  virtual void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
445
                               GlobalDecl GD, bool ReturnAdjustment) = 0;
446
447
  virtual llvm::Value *performThisAdjustment(CodeGenFunction &CGF,
448
                                             Address This,
449
                                             const ThisAdjustment &TA) = 0;
450
451
  virtual llvm::Value *performReturnAdjustment(CodeGenFunction &CGF,
452
                                               Address Ret,
453
                                               const ReturnAdjustment &RA) = 0;
454
455
  virtual void EmitReturnFromThunk(CodeGenFunction &CGF,
456
                                   RValue RV, QualType ResultType);
457
458
  virtual size_t getSrcArgforCopyCtor(const CXXConstructorDecl *,
459
                                      FunctionArgList &Args) const = 0;
460
461
  /// Gets the offsets of all the virtual base pointers in a given class.
462
  virtual std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD);
463
464
  /// Gets the pure virtual member call function.
465
  virtual StringRef GetPureVirtualCallName() = 0;
466
467
  /// Gets the deleted virtual member call name.
468
  virtual StringRef GetDeletedVirtualCallName() = 0;
469
470
  /**************************** Array cookies ******************************/
471
472
  /// Returns the extra size required in order to store the array
473
  /// cookie for the given new-expression.  May return 0 to indicate that no
474
  /// array cookie is required.
475
  ///
476
  /// Several cases are filtered out before this method is called:
477
  ///   - non-array allocations never need a cookie
478
  ///   - calls to \::operator new(size_t, void*) never need a cookie
479
  ///
480
  /// \param expr - the new-expression being allocated.
481
  virtual CharUnits GetArrayCookieSize(const CXXNewExpr *expr);
482
483
  /// Initialize the array cookie for the given allocation.
484
  ///
485
  /// \param NewPtr - a char* which is the presumed-non-null
486
  ///   return value of the allocation function
487
  /// \param NumElements - the computed number of elements,
488
  ///   potentially collapsed from the multidimensional array case;
489
  ///   always a size_t
490
  /// \param ElementType - the base element allocated type,
491
  ///   i.e. the allocated type after stripping all array types
492
  virtual Address InitializeArrayCookie(CodeGenFunction &CGF,
493
                                        Address NewPtr,
494
                                        llvm::Value *NumElements,
495
                                        const CXXNewExpr *expr,
496
                                        QualType ElementType);
497
498
  /// Reads the array cookie associated with the given pointer,
499
  /// if it has one.
500
  ///
501
  /// \param Ptr - a pointer to the first element in the array
502
  /// \param ElementType - the base element type of elements of the array
503
  /// \param NumElements - an out parameter which will be initialized
504
  ///   with the number of elements allocated, or zero if there is no
505
  ///   cookie
506
  /// \param AllocPtr - an out parameter which will be initialized
507
  ///   with a char* pointing to the address returned by the allocation
508
  ///   function
509
  /// \param CookieSize - an out parameter which will be initialized
510
  ///   with the size of the cookie, or zero if there is no cookie
511
  virtual void ReadArrayCookie(CodeGenFunction &CGF, Address Ptr,
512
                               const CXXDeleteExpr *expr,
513
                               QualType ElementType, llvm::Value *&NumElements,
514
                               llvm::Value *&AllocPtr, CharUnits &CookieSize);
515
516
  /// Return whether the given global decl needs a VTT parameter.
517
  virtual bool NeedsVTTParameter(GlobalDecl GD);
518
519
protected:
520
  /// Returns the extra size required in order to store the array
521
  /// cookie for the given type.  Assumes that an array cookie is
522
  /// required.
523
  virtual CharUnits getArrayCookieSizeImpl(QualType elementType);
524
525
  /// Reads the array cookie for an allocation which is known to have one.
526
  /// This is called by the standard implementation of ReadArrayCookie.
527
  ///
528
  /// \param ptr - a pointer to the allocation made for an array, as a char*
529
  /// \param cookieSize - the computed cookie size of an array
530
  ///
531
  /// Other parameters are as above.
532
  ///
533
  /// \return a size_t
534
  virtual llvm::Value *readArrayCookieImpl(CodeGenFunction &IGF, Address ptr,
535
                                           CharUnits cookieSize);
536
537
public:
538
539
  /*************************** Static local guards ****************************/
540
541
  /// Emits the guarded initializer and destructor setup for the given
542
  /// variable, given that it couldn't be emitted as a constant.
543
  /// If \p PerformInit is false, the initialization has been folded to a
544
  /// constant and should not be performed.
545
  ///
546
  /// The variable may be:
547
  ///   - a static local variable
548
  ///   - a static data member of a class template instantiation
549
  virtual void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
550
                               llvm::GlobalVariable *DeclPtr,
551
                               bool PerformInit) = 0;
552
553
  /// Emit code to force the execution of a destructor during global
554
  /// teardown.  The default implementation of this uses atexit.
555
  ///
556
  /// \param Dtor - a function taking a single pointer argument
557
  /// \param Addr - a pointer to pass to the destructor function.
558
  virtual void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
559
                                  llvm::FunctionCallee Dtor,
560
                                  llvm::Constant *Addr) = 0;
561
562
  /*************************** thread_local initialization ********************/
563
564
  /// Emits ABI-required functions necessary to initialize thread_local
565
  /// variables in this translation unit.
566
  ///
567
  /// \param CXXThreadLocals - The thread_local declarations in this translation
568
  ///        unit.
569
  /// \param CXXThreadLocalInits - If this translation unit contains any
570
  ///        non-constant initialization or non-trivial destruction for
571
  ///        thread_local variables, a list of functions to perform the
572
  ///        initialization.
573
  virtual void EmitThreadLocalInitFuncs(
574
      CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
575
      ArrayRef<llvm::Function *> CXXThreadLocalInits,
576
      ArrayRef<const VarDecl *> CXXThreadLocalInitVars) = 0;
577
578
  // Determine if references to thread_local global variables can be made
579
  // directly or require access through a thread wrapper function.
580
  virtual bool usesThreadWrapperFunction(const VarDecl *VD) const = 0;
581
582
  /// Emit a reference to a non-local thread_local variable (including
583
  /// triggering the initialization of all thread_local variables in its
584
  /// translation unit).
585
  virtual LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
586
                                              const VarDecl *VD,
587
                                              QualType LValType) = 0;
588
589
  /// Emit a single constructor/destructor with the given type from a C++
590
  /// constructor Decl.
591
  virtual void emitCXXStructor(GlobalDecl GD) = 0;
592
593
  /// Load a vtable from This, an object of polymorphic type RD, or from one of
594
  /// its virtual bases if it does not have its own vtable. Returns the vtable
595
  /// and the class from which the vtable was loaded.
596
  virtual std::pair<llvm::Value *, const CXXRecordDecl *>
597
  LoadVTablePtr(CodeGenFunction &CGF, Address This,
598
                const CXXRecordDecl *RD) = 0;
599
};
600
601
// Create an instance of a C++ ABI class:
602
603
/// Creates an Itanium-family ABI.
604
CGCXXABI *CreateItaniumCXXABI(CodeGenModule &CGM);
605
606
/// Creates a Microsoft-family ABI.
607
CGCXXABI *CreateMicrosoftCXXABI(CodeGenModule &CGM);
608
609
struct CatchRetScope final : EHScopeStack::Cleanup {
610
  llvm::CatchPadInst *CPI;
611
612
84
  CatchRetScope(llvm::CatchPadInst *CPI) : CPI(CPI) {}
613
614
82
  void Emit(CodeGenFunction &CGF, Flags flags) override {
615
82
    llvm::BasicBlock *BB = CGF.createBasicBlock("catchret.dest");
616
82
    CGF.Builder.CreateCatchRet(CPI, BB);
617
82
    CGF.EmitBlock(BB);
618
82
  }
619
};
620
}
621
}
622
623
#endif