1 | //===----- CGCXXABI.h - Interface to C++ ABIs -------------------*- C++ -*-===// |
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 an abstract class for C++ code generation. Concrete subclasses |
10 | // of this implement code generation for specific C++ ABIs. |
11 | // |
12 | //===----------------------------------------------------------------------===// |
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 | : CGM(CGM), MangleCtx(CGM.getContext().createMangleContext()) {} |
52 | |
53 | protected: |
54 | ImplicitParamDecl *getThisDecl(CodeGenFunction &CGF) { |
55 | return CGF.CXXABIThisDecl; |
56 | } |
57 | llvm::Value *getThisValue(CodeGenFunction &CGF) { |
58 | return CGF.CXXABIThisValue; |
59 | } |
60 | Address getThisAddress(CodeGenFunction &CGF) { |
61 | return Address( |
62 | CGF.CXXABIThisValue, |
63 | CGF.ConvertTypeForMem(T: CGF.CXXABIThisDecl->getType()->getPointeeType()), |
64 | CGF.CXXABIThisAlignment); |
65 | } |
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 | ImplicitParamDecl *&getStructorImplicitParamDecl(CodeGenFunction &CGF) { |
74 | return CGF.CXXStructorImplicitParamDecl; |
75 | } |
76 | llvm::Value *&getStructorImplicitParamValue(CodeGenFunction &CGF) { |
77 | return CGF.CXXStructorImplicitParamValue; |
78 | } |
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 | 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 | virtual bool constructorsAndDestructorsReturnThis() const { |
109 | return CGM.getCodeGenOpts().CtorDtorReturnThis; |
110 | } |
111 | |
112 | public: |
113 | |
114 | virtual ~CGCXXABI(); |
115 | |
116 | /// Gets the mangle context. |
117 | MangleContext &getMangleContext() { |
118 | return *MangleCtx; |
119 | } |
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 | virtual bool HasThisReturn(GlobalDecl GD) const { |
128 | if (isa<CXXConstructorDecl>(Val: GD.getDecl()) || |
129 | (isa<CXXDestructorDecl>(Val: GD.getDecl()) && |
130 | GD.getDtorType() != Dtor_Deleting)) |
131 | return constructorsAndDestructorsReturnThis(); |
132 | return false; |
133 | } |
134 | |
135 | virtual bool hasMostDerivedReturn(GlobalDecl GD) const { return false; } |
136 | |
137 | 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 | 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 | 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 | isPermittedToBeHomogeneousAggregate(const CXXRecordDecl *RD) const { |
179 | return true; |
180 | }; |
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 | virtual bool isMemberPointerConvertible(const MemberPointerType *MPT) const { |
218 | return true; |
219 | } |
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 | 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 | 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 | AddedStructorArgs() = default; |
343 | AddedStructorArgs(SmallVector<Arg, 1> P, SmallVector<Arg, 1> S) |
344 | : Prefix(std::move(P)), Suffix(std::move(S)) {} |
345 | static AddedStructorArgs prefix(SmallVector<Arg, 1> Args) { |
346 | return {std::move(Args), {}}; |
347 | } |
348 | static AddedStructorArgs suffix(SmallVector<Arg, 1> Args) { |
349 | return {{}, std::move(Args)}; |
350 | } |
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 | AddedStructorArgCounts() = default; |
359 | AddedStructorArgCounts(unsigned P, unsigned S) : Prefix(P), Suffix(S) {} |
360 | static AddedStructorArgCounts prefix(unsigned N) { return {N, 0}; } |
361 | 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 | virtual const CXXRecordDecl *getThisArgumentTypeForMethod(GlobalDecl GD) { |
393 | return cast<CXXMethodDecl>(Val: GD.getDecl())->getParent(); |
394 | } |
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 | Address This, bool VirtualCall) { |
402 | return This; |
403 | } |
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 | virtual CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) { |
421 | return CharUnits::Zero(); |
422 | } |
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 | 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 | CatchRetScope(llvm::CatchPadInst *CPI) : CPI(CPI) {} |
684 | |
685 | void Emit(CodeGenFunction &CGF, Flags flags) override { |
686 | llvm::BasicBlock *BB = CGF.createBasicBlock(name: "catchret.dest" ); |
687 | CGF.Builder.CreateCatchRet(CatchPad: CPI, BB); |
688 | CGF.EmitBlock(BB); |
689 | } |
690 | }; |
691 | } |
692 | } |
693 | |
694 | #endif |
695 | |