Coverage Report

Created: 2023-11-11 10:31

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/CodeGen/CGCXXABI.h
Line
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//===----- CGCXXABI.h - Interface to C++ ABIs -------------------*- C++ -*-===//
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//
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 an abstract class for C++ code generation. Concrete subclasses
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// of this implement code generation for specific C++ ABIs.
11
//
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//===----------------------------------------------------------------------===//
13
14
#ifndef LLVM_CLANG_LIB_CODEGEN_CGCXXABI_H
15
#define LLVM_CLANG_LIB_CODEGEN_CGCXXABI_H
16
17
#include "CodeGenFunction.h"
18
#include "clang/Basic/LLVM.h"
19
#include "clang/CodeGen/CodeGenABITypes.h"
20
21
namespace llvm {
22
class Constant;
23
class Type;
24
class Value;
25
class CallInst;
26
}
27
28
namespace clang {
29
class CastExpr;
30
class CXXConstructorDecl;
31
class CXXDestructorDecl;
32
class CXXMethodDecl;
33
class CXXRecordDecl;
34
class MangleContext;
35
36
namespace CodeGen {
37
class CGCallee;
38
class CodeGenFunction;
39
class CodeGenModule;
40
struct CatchTypeInfo;
41
42
/// Implements C++ ABI-specific code generation functions.
43
class CGCXXABI {
44
  friend class CodeGenModule;
45
46
protected:
47
  CodeGenModule &CGM;
48
  std::unique_ptr<MangleContext> MangleCtx;
49
50
  CGCXXABI(CodeGenModule &CGM)
51
34.2k
    : CGM(CGM), MangleCtx(CGM.getContext().createMangleContext()) {}
52
53
protected:
54
197k
  ImplicitParamDecl *getThisDecl(CodeGenFunction &CGF) {
55
197k
    return CGF.CXXABIThisDecl;
56
197k
  }
57
2.26k
  llvm::Value *getThisValue(CodeGenFunction &CGF) {
58
2.26k
    return CGF.CXXABIThisValue;
59
2.26k
  }
60
540
  Address getThisAddress(CodeGenFunction &CGF) {
61
540
    return Address(
62
540
        CGF.CXXABIThisValue,
63
540
        CGF.ConvertTypeForMem(CGF.CXXABIThisDecl->getType()->getPointeeType()),
64
540
        CGF.CXXABIThisAlignment);
65
540
  }
66
67
  /// Issue a diagnostic about unsupported features in the ABI.
68
  void ErrorUnsupportedABI(CodeGenFunction &CGF, StringRef S);
69
70
  /// Get a null value for unsupported member pointers.
71
  llvm::Constant *GetBogusMemberPointer(QualType T);
72
73
97.8k
  ImplicitParamDecl *&getStructorImplicitParamDecl(CodeGenFunction &CGF) {
74
97.8k
    return CGF.CXXStructorImplicitParamDecl;
75
97.8k
  }
76
1.58k
  llvm::Value *&getStructorImplicitParamValue(CodeGenFunction &CGF) {
77
1.58k
    return CGF.CXXStructorImplicitParamValue;
78
1.58k
  }
79
80
  /// Loads the incoming C++ this pointer as it was passed by the caller.
81
  llvm::Value *loadIncomingCXXThis(CodeGenFunction &CGF);
82
83
  void setCXXABIThisValue(CodeGenFunction &CGF, llvm::Value *ThisPtr);
84
85
394k
  ASTContext &getContext() const { return CGM.getContext(); }
86
87
  bool mayNeedDestruction(const VarDecl *VD) const;
88
89
  /// Determine whether we will definitely emit this variable with a constant
90
  /// initializer, either because the language semantics demand it or because
91
  /// we know that the initializer is a constant.
92
  // For weak definitions, any initializer available in the current translation
93
  // is not necessarily reflective of the initializer used; such initializers
94
  // are ignored unless if InspectInitForWeakDef is true.
95
  bool
96
  isEmittedWithConstantInitializer(const VarDecl *VD,
97
                                   bool InspectInitForWeakDef = false) const;
98
99
  virtual bool requiresArrayCookie(const CXXDeleteExpr *E, QualType eltType);
100
  virtual bool requiresArrayCookie(const CXXNewExpr *E);
101
102
  /// Determine whether there's something special about the rules of
103
  /// the ABI tell us that 'this' is a complete object within the
104
  /// given function.  Obvious common logic like being defined on a
105
  /// final class will have been taken care of by the caller.
106
  virtual bool isThisCompleteObject(GlobalDecl GD) const = 0;
107
108
500k
  virtual bool constructorsAndDestructorsReturnThis() const {
109
500k
    return CGM.getCodeGenOpts().CtorDtorReturnThis;
110
500k
  }
111
112
public:
113
114
  virtual ~CGCXXABI();
115
116
  /// Gets the mangle context.
117
5.00M
  MangleContext &getMangleContext() {
118
5.00M
    return *MangleCtx;
119
5.00M
  }
120
121
  /// Returns true if the given constructor or destructor is one of the
122
  /// kinds that the ABI says returns 'this' (only applies when called
123
  /// non-virtually for destructors).
124
  ///
125
  /// There currently is no way to indicate if a destructor returns 'this'
126
  /// when called virtually, and code generation does not support the case.
127
826k
  virtual bool HasThisReturn(GlobalDecl GD) const {
128
826k
    if (isa<CXXConstructorDecl>(GD.getDecl()) ||
129
826k
        
(487k
isa<CXXDestructorDecl>(GD.getDecl())487k
&&
130
487k
         
GD.getDtorType() != Dtor_Deleting169k
))
131
504k
      return constructorsAndDestructorsReturnThis();
132
322k
    return false;
133
826k
  }
134
135
428k
  virtual bool hasMostDerivedReturn(GlobalDecl GD) const { return false; }
136
137
35.1k
  virtual bool useSinitAndSterm() const { return false; }
138
139
  /// Returns true if the target allows calling a function through a pointer
140
  /// with a different signature than the actual function (or equivalently,
141
  /// bitcasting a function or function pointer to a different function type).
142
  /// In principle in the most general case this could depend on the target, the
143
  /// calling convention, and the actual types of the arguments and return
144
  /// value. Here it just means whether the signature mismatch could *ever* be
145
  /// allowed; in other words, does the target do strict checking of signatures
146
  /// for all calls.
147
7
  virtual bool canCallMismatchedFunctionType() const { return true; }
148
149
  /// If the C++ ABI requires the given type be returned in a particular way,
150
  /// this method sets RetAI and returns true.
151
  virtual bool classifyReturnType(CGFunctionInfo &FI) const = 0;
152
153
  /// Specify how one should pass an argument of a record type.
154
  enum RecordArgABI {
155
    /// Pass it using the normal C aggregate rules for the ABI, potentially
156
    /// introducing extra copies and passing some or all of it in registers.
157
    RAA_Default = 0,
158
159
    /// Pass it on the stack using its defined layout.  The argument must be
160
    /// evaluated directly into the correct stack position in the arguments area,
161
    /// and the call machinery must not move it or introduce extra copies.
162
    RAA_DirectInMemory,
163
164
    /// Pass it as a pointer to temporary memory.
165
    RAA_Indirect
166
  };
167
168
  /// Returns how an argument of the given record type should be passed.
169
  virtual RecordArgABI getRecordArgABI(const CXXRecordDecl *RD) const = 0;
170
171
  /// Returns true if the implicit 'sret' parameter comes after the implicit
172
  /// 'this' parameter of C++ instance methods.
173
0
  virtual bool isSRetParameterAfterThis() const { return false; }
174
175
  /// Returns true if the ABI permits the argument to be a homogeneous
176
  /// aggregate.
177
  virtual bool
178
490
  isPermittedToBeHomogeneousAggregate(const CXXRecordDecl *RD) const {
179
490
    return true;
180
490
  };
181
182
  /// Find the LLVM type used to represent the given member pointer
183
  /// type.
184
  virtual llvm::Type *
185
  ConvertMemberPointerType(const MemberPointerType *MPT);
186
187
  /// Load a member function from an object and a member function
188
  /// pointer.  Apply the this-adjustment and set 'This' to the
189
  /// adjusted value.
190
  virtual CGCallee EmitLoadOfMemberFunctionPointer(
191
      CodeGenFunction &CGF, const Expr *E, Address This,
192
      llvm::Value *&ThisPtrForCall, llvm::Value *MemPtr,
193
      const MemberPointerType *MPT);
194
195
  /// Calculate an l-value from an object and a data member pointer.
196
  virtual llvm::Value *
197
  EmitMemberDataPointerAddress(CodeGenFunction &CGF, const Expr *E,
198
                               Address Base, llvm::Value *MemPtr,
199
                               const MemberPointerType *MPT);
200
201
  /// Perform a derived-to-base, base-to-derived, or bitcast member
202
  /// pointer conversion.
203
  virtual llvm::Value *EmitMemberPointerConversion(CodeGenFunction &CGF,
204
                                                   const CastExpr *E,
205
                                                   llvm::Value *Src);
206
207
  /// Perform a derived-to-base, base-to-derived, or bitcast member
208
  /// pointer conversion on a constant value.
209
  virtual llvm::Constant *EmitMemberPointerConversion(const CastExpr *E,
210
                                                      llvm::Constant *Src);
211
212
  /// Return true if the given member pointer can be zero-initialized
213
  /// (in the C++ sense) with an LLVM zeroinitializer.
214
  virtual bool isZeroInitializable(const MemberPointerType *MPT);
215
216
  /// Return whether or not a member pointers type is convertible to an IR type.
217
588
  virtual bool isMemberPointerConvertible(const MemberPointerType *MPT) const {
218
588
    return true;
219
588
  }
220
221
  /// Create a null member pointer of the given type.
222
  virtual llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT);
223
224
  /// Create a member pointer for the given method.
225
  virtual llvm::Constant *EmitMemberFunctionPointer(const CXXMethodDecl *MD);
226
227
  /// Create a member pointer for the given field.
228
  virtual llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
229
                                                CharUnits offset);
230
231
  /// Create a member pointer for the given member pointer constant.
232
  virtual llvm::Constant *EmitMemberPointer(const APValue &MP, QualType MPT);
233
234
  /// Emit a comparison between two member pointers.  Returns an i1.
235
  virtual llvm::Value *
236
  EmitMemberPointerComparison(CodeGenFunction &CGF,
237
                              llvm::Value *L,
238
                              llvm::Value *R,
239
                              const MemberPointerType *MPT,
240
                              bool Inequality);
241
242
  /// Determine if a member pointer is non-null.  Returns an i1.
243
  virtual llvm::Value *
244
  EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
245
                             llvm::Value *MemPtr,
246
                             const MemberPointerType *MPT);
247
248
protected:
249
  /// A utility method for computing the offset required for the given
250
  /// base-to-derived or derived-to-base member-pointer conversion.
251
  /// Does not handle virtual conversions (in case we ever fully
252
  /// support an ABI that allows this).  Returns null if no adjustment
253
  /// is required.
254
  llvm::Constant *getMemberPointerAdjustment(const CastExpr *E);
255
256
public:
257
  virtual void emitVirtualObjectDelete(CodeGenFunction &CGF,
258
                                       const CXXDeleteExpr *DE,
259
                                       Address Ptr, QualType ElementType,
260
                                       const CXXDestructorDecl *Dtor) = 0;
261
  virtual void emitRethrow(CodeGenFunction &CGF, bool isNoReturn) = 0;
262
  virtual void emitThrow(CodeGenFunction &CGF, const CXXThrowExpr *E) = 0;
263
0
  virtual llvm::GlobalVariable *getThrowInfo(QualType T) { return nullptr; }
264
265
  /// Determine whether it's possible to emit a vtable for \p RD, even
266
  /// though we do not know that the vtable has been marked as used by semantic
267
  /// analysis.
268
  virtual bool canSpeculativelyEmitVTable(const CXXRecordDecl *RD) const = 0;
269
270
  virtual void emitBeginCatch(CodeGenFunction &CGF, const CXXCatchStmt *C) = 0;
271
272
  virtual llvm::CallInst *
273
  emitTerminateForUnexpectedException(CodeGenFunction &CGF,
274
                                      llvm::Value *Exn);
275
276
  virtual llvm::Constant *getAddrOfRTTIDescriptor(QualType Ty) = 0;
277
  virtual CatchTypeInfo
278
  getAddrOfCXXCatchHandlerType(QualType Ty, QualType CatchHandlerType) = 0;
279
  virtual CatchTypeInfo getCatchAllTypeInfo();
280
281
  virtual bool shouldTypeidBeNullChecked(bool IsDeref,
282
                                         QualType SrcRecordTy) = 0;
283
  virtual void EmitBadTypeidCall(CodeGenFunction &CGF) = 0;
284
  virtual llvm::Value *EmitTypeid(CodeGenFunction &CGF, QualType SrcRecordTy,
285
                                  Address ThisPtr,
286
                                  llvm::Type *StdTypeInfoPtrTy) = 0;
287
288
  virtual bool shouldDynamicCastCallBeNullChecked(bool SrcIsPtr,
289
                                                  QualType SrcRecordTy) = 0;
290
  virtual bool shouldEmitExactDynamicCast(QualType DestRecordTy) = 0;
291
292
  virtual llvm::Value *emitDynamicCastCall(CodeGenFunction &CGF, Address Value,
293
                                           QualType SrcRecordTy,
294
                                           QualType DestTy,
295
                                           QualType DestRecordTy,
296
                                           llvm::BasicBlock *CastEnd) = 0;
297
298
  virtual llvm::Value *emitDynamicCastToVoid(CodeGenFunction &CGF,
299
                                             Address Value,
300
                                             QualType SrcRecordTy) = 0;
301
302
  /// Emit a dynamic_cast from SrcRecordTy to DestRecordTy. The cast fails if
303
  /// the dynamic type of Value is not exactly DestRecordTy.
304
  virtual llvm::Value *emitExactDynamicCast(CodeGenFunction &CGF, Address Value,
305
                                            QualType SrcRecordTy,
306
                                            QualType DestTy,
307
                                            QualType DestRecordTy,
308
                                            llvm::BasicBlock *CastSuccess,
309
                                            llvm::BasicBlock *CastFail) = 0;
310
311
  virtual bool EmitBadCastCall(CodeGenFunction &CGF) = 0;
312
313
  virtual llvm::Value *GetVirtualBaseClassOffset(CodeGenFunction &CGF,
314
                                                 Address This,
315
                                                 const CXXRecordDecl *ClassDecl,
316
                                        const CXXRecordDecl *BaseClassDecl) = 0;
317
318
  virtual llvm::BasicBlock *EmitCtorCompleteObjectHandler(CodeGenFunction &CGF,
319
                                                          const CXXRecordDecl *RD);
320
321
  /// Emit the code to initialize hidden members required
322
  /// to handle virtual inheritance, if needed by the ABI.
323
  virtual void
324
  initializeHiddenVirtualInheritanceMembers(CodeGenFunction &CGF,
325
558
                                            const CXXRecordDecl *RD) {}
326
327
  /// Emit constructor variants required by this ABI.
328
  virtual void EmitCXXConstructors(const CXXConstructorDecl *D) = 0;
329
330
  /// Additional implicit arguments to add to the beginning (Prefix) and end
331
  /// (Suffix) of a constructor / destructor arg list.
332
  ///
333
  /// Note that Prefix should actually be inserted *after* the first existing
334
  /// arg; `this` arguments always come first.
335
  struct AddedStructorArgs {
336
    struct Arg {
337
      llvm::Value *Value;
338
      QualType Type;
339
    };
340
    SmallVector<Arg, 1> Prefix;
341
    SmallVector<Arg, 1> Suffix;
342
53.9k
    AddedStructorArgs() = default;
343
    AddedStructorArgs(SmallVector<Arg, 1> P, SmallVector<Arg, 1> S)
344
685
        : Prefix(std::move(P)), Suffix(std::move(S)) {}
345
182
    static AddedStructorArgs prefix(SmallVector<Arg, 1> Args) {
346
182
      return {std::move(Args), {}};
347
182
    }
348
503
    static AddedStructorArgs suffix(SmallVector<Arg, 1> Args) {
349
503
      return {{}, std::move(Args)};
350
503
    }
351
  };
352
353
  /// Similar to AddedStructorArgs, but only notes the number of additional
354
  /// arguments.
355
  struct AddedStructorArgCounts {
356
    unsigned Prefix = 0;
357
    unsigned Suffix = 0;
358
293k
    AddedStructorArgCounts() = default;
359
55.9k
    AddedStructorArgCounts(unsigned P, unsigned S) : Prefix(P), Suffix(S) {}
360
1.40k
    static AddedStructorArgCounts prefix(unsigned N) { return {N, 0}; }
361
0
    static AddedStructorArgCounts suffix(unsigned N) { return {0, N}; }
362
  };
363
364
  /// Build the signature of the given constructor or destructor variant by
365
  /// adding any required parameters.  For convenience, ArgTys has been
366
  /// initialized with the type of 'this'.
367
  virtual AddedStructorArgCounts
368
  buildStructorSignature(GlobalDecl GD,
369
                         SmallVectorImpl<CanQualType> &ArgTys) = 0;
370
371
  /// Returns true if the given destructor type should be emitted as a linkonce
372
  /// delegating thunk, regardless of whether the dtor is defined in this TU or
373
  /// not.
374
  virtual bool useThunkForDtorVariant(const CXXDestructorDecl *Dtor,
375
                                      CXXDtorType DT) const = 0;
376
377
  virtual void setCXXDestructorDLLStorage(llvm::GlobalValue *GV,
378
                                          const CXXDestructorDecl *Dtor,
379
                                          CXXDtorType DT) const;
380
381
  virtual llvm::GlobalValue::LinkageTypes
382
  getCXXDestructorLinkage(GVALinkage Linkage, const CXXDestructorDecl *Dtor,
383
                          CXXDtorType DT) const;
384
385
  /// Emit destructor variants required by this ABI.
386
  virtual void EmitCXXDestructors(const CXXDestructorDecl *D) = 0;
387
388
  /// Get the type of the implicit "this" parameter used by a method. May return
389
  /// zero if no specific type is applicable, e.g. if the ABI expects the "this"
390
  /// parameter to point to some artificial offset in a complete object due to
391
  /// vbases being reordered.
392
573k
  virtual const CXXRecordDecl *getThisArgumentTypeForMethod(GlobalDecl GD) {
393
573k
    return cast<CXXMethodDecl>(GD.getDecl())->getParent();
394
573k
  }
395
396
  /// Perform ABI-specific "this" argument adjustment required prior to
397
  /// a call of a virtual function.
398
  /// The "VirtualCall" argument is true iff the call itself is virtual.
399
  virtual Address
400
  adjustThisArgumentForVirtualFunctionCall(CodeGenFunction &CGF, GlobalDecl GD,
401
1.03k
                                           Address This, bool VirtualCall) {
402
1.03k
    return This;
403
1.03k
  }
404
405
  /// Build a parameter variable suitable for 'this'.
406
  void buildThisParam(CodeGenFunction &CGF, FunctionArgList &Params);
407
408
  /// Insert any ABI-specific implicit parameters into the parameter list for a
409
  /// function.  This generally involves extra data for constructors and
410
  /// destructors.
411
  ///
412
  /// ABIs may also choose to override the return type, which has been
413
  /// initialized with the type of 'this' if HasThisReturn(CGF.CurGD) is true or
414
  /// the formal return type of the function otherwise.
415
  virtual void addImplicitStructorParams(CodeGenFunction &CGF, QualType &ResTy,
416
                                         FunctionArgList &Params) = 0;
417
418
  /// Get the ABI-specific "this" parameter adjustment to apply in the prologue
419
  /// of a virtual function.
420
0
  virtual CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) {
421
0
    return CharUnits::Zero();
422
0
  }
423
424
  /// Emit the ABI-specific prolog for the function.
425
  virtual void EmitInstanceFunctionProlog(CodeGenFunction &CGF) = 0;
426
427
  virtual AddedStructorArgs
428
  getImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
429
                             CXXCtorType Type, bool ForVirtualBase,
430
                             bool Delegating) = 0;
431
432
  /// Add any ABI-specific implicit arguments needed to call a constructor.
433
  ///
434
  /// \return The number of arguments added at the beginning and end of the
435
  /// call, which is typically zero or one.
436
  AddedStructorArgCounts
437
  addImplicitConstructorArgs(CodeGenFunction &CGF, const CXXConstructorDecl *D,
438
                             CXXCtorType Type, bool ForVirtualBase,
439
                             bool Delegating, CallArgList &Args);
440
441
  /// Get the implicit (second) parameter that comes after the "this" pointer,
442
  /// or nullptr if there is isn't one.
443
  virtual llvm::Value *
444
  getCXXDestructorImplicitParam(CodeGenFunction &CGF,
445
                                const CXXDestructorDecl *DD, CXXDtorType Type,
446
                                bool ForVirtualBase, bool Delegating) = 0;
447
448
  /// Emit the destructor call.
449
  virtual void EmitDestructorCall(CodeGenFunction &CGF,
450
                                  const CXXDestructorDecl *DD, CXXDtorType Type,
451
                                  bool ForVirtualBase, bool Delegating,
452
                                  Address This, QualType ThisTy) = 0;
453
454
  /// Emits the VTable definitions required for the given record type.
455
  virtual void emitVTableDefinitions(CodeGenVTables &CGVT,
456
                                     const CXXRecordDecl *RD) = 0;
457
458
  /// Checks if ABI requires extra virtual offset for vtable field.
459
  virtual bool
460
  isVirtualOffsetNeededForVTableField(CodeGenFunction &CGF,
461
                                      CodeGenFunction::VPtr Vptr) = 0;
462
463
  /// Checks if ABI requires to initialize vptrs for given dynamic class.
464
  virtual bool doStructorsInitializeVPtrs(const CXXRecordDecl *VTableClass) = 0;
465
466
  /// Get the address point of the vtable for the given base subobject.
467
  virtual llvm::Constant *
468
  getVTableAddressPoint(BaseSubobject Base,
469
                        const CXXRecordDecl *VTableClass) = 0;
470
471
  /// Get the address point of the vtable for the given base subobject while
472
  /// building a constructor or a destructor.
473
  virtual llvm::Value *
474
  getVTableAddressPointInStructor(CodeGenFunction &CGF, const CXXRecordDecl *RD,
475
                                  BaseSubobject Base,
476
                                  const CXXRecordDecl *NearestVBase) = 0;
477
478
  /// Get the address point of the vtable for the given base subobject while
479
  /// building a constexpr.
480
  virtual llvm::Constant *
481
  getVTableAddressPointForConstExpr(BaseSubobject Base,
482
                                    const CXXRecordDecl *VTableClass) = 0;
483
484
  /// Get the address of the vtable for the given record decl which should be
485
  /// used for the vptr at the given offset in RD.
486
  virtual llvm::GlobalVariable *getAddrOfVTable(const CXXRecordDecl *RD,
487
                                                CharUnits VPtrOffset) = 0;
488
489
  /// Build a virtual function pointer in the ABI-specific way.
490
  virtual CGCallee getVirtualFunctionPointer(CodeGenFunction &CGF,
491
                                             GlobalDecl GD, Address This,
492
                                             llvm::Type *Ty,
493
                                             SourceLocation Loc) = 0;
494
495
  using DeleteOrMemberCallExpr =
496
      llvm::PointerUnion<const CXXDeleteExpr *, const CXXMemberCallExpr *>;
497
498
  /// Emit the ABI-specific virtual destructor call.
499
  virtual llvm::Value *EmitVirtualDestructorCall(CodeGenFunction &CGF,
500
                                                 const CXXDestructorDecl *Dtor,
501
                                                 CXXDtorType DtorType,
502
                                                 Address This,
503
                                                 DeleteOrMemberCallExpr E) = 0;
504
505
  virtual void adjustCallArgsForDestructorThunk(CodeGenFunction &CGF,
506
                                                GlobalDecl GD,
507
159
                                                CallArgList &CallArgs) {}
508
509
  /// Emit any tables needed to implement virtual inheritance.  For Itanium,
510
  /// this emits virtual table tables.  For the MSVC++ ABI, this emits virtual
511
  /// base tables.
512
  virtual void emitVirtualInheritanceTables(const CXXRecordDecl *RD) = 0;
513
514
  virtual bool exportThunk() = 0;
515
  virtual void setThunkLinkage(llvm::Function *Thunk, bool ForVTable,
516
                               GlobalDecl GD, bool ReturnAdjustment) = 0;
517
518
  virtual llvm::Value *performThisAdjustment(CodeGenFunction &CGF,
519
                                             Address This,
520
                                             const ThisAdjustment &TA) = 0;
521
522
  virtual llvm::Value *performReturnAdjustment(CodeGenFunction &CGF,
523
                                               Address Ret,
524
                                               const ReturnAdjustment &RA) = 0;
525
526
  virtual void EmitReturnFromThunk(CodeGenFunction &CGF,
527
                                   RValue RV, QualType ResultType);
528
529
  virtual size_t getSrcArgforCopyCtor(const CXXConstructorDecl *,
530
                                      FunctionArgList &Args) const = 0;
531
532
  /// Gets the offsets of all the virtual base pointers in a given class.
533
  virtual std::vector<CharUnits> getVBPtrOffsets(const CXXRecordDecl *RD);
534
535
  /// Gets the pure virtual member call function.
536
  virtual StringRef GetPureVirtualCallName() = 0;
537
538
  /// Gets the deleted virtual member call name.
539
  virtual StringRef GetDeletedVirtualCallName() = 0;
540
541
  /**************************** Array cookies ******************************/
542
543
  /// Returns the extra size required in order to store the array
544
  /// cookie for the given new-expression.  May return 0 to indicate that no
545
  /// array cookie is required.
546
  ///
547
  /// Several cases are filtered out before this method is called:
548
  ///   - non-array allocations never need a cookie
549
  ///   - calls to \::operator new(size_t, void*) never need a cookie
550
  ///
551
  /// \param expr - the new-expression being allocated.
552
  virtual CharUnits GetArrayCookieSize(const CXXNewExpr *expr);
553
554
  /// Initialize the array cookie for the given allocation.
555
  ///
556
  /// \param NewPtr - a char* which is the presumed-non-null
557
  ///   return value of the allocation function
558
  /// \param NumElements - the computed number of elements,
559
  ///   potentially collapsed from the multidimensional array case;
560
  ///   always a size_t
561
  /// \param ElementType - the base element allocated type,
562
  ///   i.e. the allocated type after stripping all array types
563
  virtual Address InitializeArrayCookie(CodeGenFunction &CGF,
564
                                        Address NewPtr,
565
                                        llvm::Value *NumElements,
566
                                        const CXXNewExpr *expr,
567
                                        QualType ElementType);
568
569
  /// Reads the array cookie associated with the given pointer,
570
  /// if it has one.
571
  ///
572
  /// \param Ptr - a pointer to the first element in the array
573
  /// \param ElementType - the base element type of elements of the array
574
  /// \param NumElements - an out parameter which will be initialized
575
  ///   with the number of elements allocated, or zero if there is no
576
  ///   cookie
577
  /// \param AllocPtr - an out parameter which will be initialized
578
  ///   with a char* pointing to the address returned by the allocation
579
  ///   function
580
  /// \param CookieSize - an out parameter which will be initialized
581
  ///   with the size of the cookie, or zero if there is no cookie
582
  virtual void ReadArrayCookie(CodeGenFunction &CGF, Address Ptr,
583
                               const CXXDeleteExpr *expr,
584
                               QualType ElementType, llvm::Value *&NumElements,
585
                               llvm::Value *&AllocPtr, CharUnits &CookieSize);
586
587
  /// Return whether the given global decl needs a VTT parameter.
588
  virtual bool NeedsVTTParameter(GlobalDecl GD);
589
590
protected:
591
  /// Returns the extra size required in order to store the array
592
  /// cookie for the given type.  Assumes that an array cookie is
593
  /// required.
594
  virtual CharUnits getArrayCookieSizeImpl(QualType elementType);
595
596
  /// Reads the array cookie for an allocation which is known to have one.
597
  /// This is called by the standard implementation of ReadArrayCookie.
598
  ///
599
  /// \param ptr - a pointer to the allocation made for an array, as a char*
600
  /// \param cookieSize - the computed cookie size of an array
601
  ///
602
  /// Other parameters are as above.
603
  ///
604
  /// \return a size_t
605
  virtual llvm::Value *readArrayCookieImpl(CodeGenFunction &IGF, Address ptr,
606
                                           CharUnits cookieSize);
607
608
public:
609
610
  /*************************** Static local guards ****************************/
611
612
  /// Emits the guarded initializer and destructor setup for the given
613
  /// variable, given that it couldn't be emitted as a constant.
614
  /// If \p PerformInit is false, the initialization has been folded to a
615
  /// constant and should not be performed.
616
  ///
617
  /// The variable may be:
618
  ///   - a static local variable
619
  ///   - a static data member of a class template instantiation
620
  virtual void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
621
                               llvm::GlobalVariable *DeclPtr,
622
                               bool PerformInit) = 0;
623
624
  /// Emit code to force the execution of a destructor during global
625
  /// teardown.  The default implementation of this uses atexit.
626
  ///
627
  /// \param Dtor - a function taking a single pointer argument
628
  /// \param Addr - a pointer to pass to the destructor function.
629
  virtual void registerGlobalDtor(CodeGenFunction &CGF, const VarDecl &D,
630
                                  llvm::FunctionCallee Dtor,
631
                                  llvm::Constant *Addr) = 0;
632
633
  /*************************** thread_local initialization ********************/
634
635
  /// Emits ABI-required functions necessary to initialize thread_local
636
  /// variables in this translation unit.
637
  ///
638
  /// \param CXXThreadLocals - The thread_local declarations in this translation
639
  ///        unit.
640
  /// \param CXXThreadLocalInits - If this translation unit contains any
641
  ///        non-constant initialization or non-trivial destruction for
642
  ///        thread_local variables, a list of functions to perform the
643
  ///        initialization.
644
  virtual void EmitThreadLocalInitFuncs(
645
      CodeGenModule &CGM, ArrayRef<const VarDecl *> CXXThreadLocals,
646
      ArrayRef<llvm::Function *> CXXThreadLocalInits,
647
      ArrayRef<const VarDecl *> CXXThreadLocalInitVars) = 0;
648
649
  // Determine if references to thread_local global variables can be made
650
  // directly or require access through a thread wrapper function.
651
  virtual bool usesThreadWrapperFunction(const VarDecl *VD) const = 0;
652
653
  /// Emit a reference to a non-local thread_local variable (including
654
  /// triggering the initialization of all thread_local variables in its
655
  /// translation unit).
656
  virtual LValue EmitThreadLocalVarDeclLValue(CodeGenFunction &CGF,
657
                                              const VarDecl *VD,
658
                                              QualType LValType) = 0;
659
660
  /// Emit a single constructor/destructor with the given type from a C++
661
  /// constructor Decl.
662
  virtual void emitCXXStructor(GlobalDecl GD) = 0;
663
664
  /// Load a vtable from This, an object of polymorphic type RD, or from one of
665
  /// its virtual bases if it does not have its own vtable. Returns the vtable
666
  /// and the class from which the vtable was loaded.
667
  virtual std::pair<llvm::Value *, const CXXRecordDecl *>
668
  LoadVTablePtr(CodeGenFunction &CGF, Address This,
669
                const CXXRecordDecl *RD) = 0;
670
};
671
672
// Create an instance of a C++ ABI class:
673
674
/// Creates an Itanium-family ABI.
675
CGCXXABI *CreateItaniumCXXABI(CodeGenModule &CGM);
676
677
/// Creates a Microsoft-family ABI.
678
CGCXXABI *CreateMicrosoftCXXABI(CodeGenModule &CGM);
679
680
struct CatchRetScope final : EHScopeStack::Cleanup {
681
  llvm::CatchPadInst *CPI;
682
683
46
  CatchRetScope(llvm::CatchPadInst *CPI) : CPI(CPI) {}
684
685
43
  void Emit(CodeGenFunction &CGF, Flags flags) override {
686
43
    llvm::BasicBlock *BB = CGF.createBasicBlock("catchret.dest");
687
43
    CGF.Builder.CreateCatchRet(CPI, BB);
688
43
    CGF.EmitBlock(BB);
689
43
  }
690
};
691
}
692
}
693
694
#endif