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 20 namespace llvm { 21 class Constant; 22 class Type; 23 class Value; 24 class CallInst; 25 } 26 27 namespace clang { 28 class CastExpr; 29 class CXXConstructorDecl; 30 class CXXDestructorDecl; 31 class CXXMethodDecl; 32 class CXXRecordDecl; 33 class FieldDecl; 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 protected: 45 CodeGenModule &CGM; 46 std::unique_ptr<MangleContext> MangleCtx; 47 48 CGCXXABI(CodeGenModule &CGM) 49 : CGM(CGM), MangleCtx(CGM.getContext().createMangleContext()) {} 50 51 protected: 52 ImplicitParamDecl *getThisDecl(CodeGenFunction &CGF) { 53 return CGF.CXXABIThisDecl; 54 } 55 llvm::Value *getThisValue(CodeGenFunction &CGF) { 56 return CGF.CXXABIThisValue; 57 } 58 Address getThisAddress(CodeGenFunction &CGF) { 59 return Address(CGF.CXXABIThisValue, CGF.CXXABIThisAlignment); 60 } 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); 67 68 ImplicitParamDecl *&getStructorImplicitParamDecl(CodeGenFunction &CGF) { 69 return CGF.CXXStructorImplicitParamDecl; 70 } 71 llvm::Value *&getStructorImplicitParamValue(CodeGenFunction &CGF) { 72 return CGF.CXXStructorImplicitParamValue; 73 } 74 75 /// Loads the incoming C++ this pointer as it was passed by the caller. 76 llvm::Value *loadIncomingCXXThis(CodeGenFunction &CGF); 77 78 void setCXXABIThisValue(CodeGenFunction &CGF, llvm::Value *ThisPtr); 79 80 ASTContext &getContext() const { return CGM.getContext(); } 81 82 virtual bool requiresArrayCookie(const CXXDeleteExpr *E, QualType eltType); 83 virtual bool requiresArrayCookie(const CXXNewExpr *E); 84 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 88 /// 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 MangleContext &getMangleContext() { 97 return *MangleCtx; 98 } 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 virtual bool HasThisReturn(GlobalDecl GD) const { return false; } 107 108 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). 113 /// 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 117 /// for all calls. 118 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; 123 124 /// 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 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 153 /// 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); 158 159 /// 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 virtual bool isMemberPointerConvertible(const MemberPointerType *MPT) const { 182 return true; 183 } 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 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 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; 298 AddedStructorArgs() = default; 299 AddedStructorArgs(unsigned P, unsigned S) : Prefix(P), Suffix(S) {} 300 static AddedStructorArgs prefix(unsigned N) { return {N, 0}; } 301 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 306 /// 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 getThisArgumentTypeForMethod(const CXXMethodDecl *MD) { 334 return MD->getParent(); 335 } 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 Address This, bool VirtualCall) { 343 return This; 344 } 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 virtual CharUnits getVirtualFunctionPrologueThisAdjustment(GlobalDecl GD) { 362 return CharUnits::Zero(); 363 } 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 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 CatchRetScope(llvm::CatchPadInst *CPI) : CPI(CPI) {} 613 614 void Emit(CodeGenFunction &CGF, Flags flags) override { 615 llvm::BasicBlock *BB = CGF.createBasicBlock("catchret.dest"); 616 CGF.Builder.CreateCatchRet(CPI, BB); 617 CGF.EmitBlock(BB); 618 } 619 }; 620 } 621 } 622 623 #endif 624